Thumbnailjpg

The Biology and Troubleshooting of

Facultative Lagoons

WasteWater Microbiology series

Editor

Michael H gerardi

Nitrification and Denitrification in the Activated Sludge ProcessMichael H gerardi

Settleability Problems and Loss of Solids in the Activated Sludge ProcessMichael H gerardi

The Microbiology of Anaerobic DigestersMichael H gerardi

Wastewater PathogensMichael H gerardi and Mel c Zimmerman

Wastewater BacteriaMichael H gerardi

Microscopic Examination of the Activated Sludge ProcessMichael H gerardi

Troubleshooting the Sequencing Batch ReactorMichael H gerardi

The Biology and Troubleshooting of Facultative LagoonsMichael H gerardi

The Biology and Troubleshooting of

Facultative Lagoons

Michael H Gerardi

Illustrations by Brittany Lytle

Copyright copy 2015 by John Wiley amp Sons Inc All rights reserved

Published by John Wiley amp Sons Inc Hoboken New JerseyPublished simultaneously in Canada

No part of this publication may be reproduced stored in a retrieval system or transmitted in any form or by any means electronic mechanical photocopying recording scanning or otherwise except as permitted under Section 107 or 108 of the 1976 United States Copyright Act without either the prior written permission of the Publisher or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center Inc 222 Rosewood Drive Danvers MA 01923 (978) 750-8400 fax (978) 750-4470 or on the web at wwwcopyrightcom Requests to the Publisher for permission should be addressed to the Permissions Department John Wiley amp Sons Inc 111 River Street Hoboken NJ 07030 (201) 748-6011 fax (201) 748-6008 or online at httpwwwwileycomgopermission

Limit of LiabilityDisclaimer of Warranty While the publisher and author have used their best efforts in preparing this book they make no representations or warranties with respect to the accuracy or completeness of the contents of this book and specifically disclaim any implied warranties of merchantability or fitness for a particular purpose No warranty may be created or extended by sales representatives or written sales materials The advice and strategies contained herein may not be suitable for your situation You should consult with a professional where appropriate Neither the publisher nor author shall be liable for any loss of profit or any other commercial damages including but not limited to special incidental consequential or other damages

For general information on our other products and services or for technical support please contact our Customer Care Department within the United States at (800) 762-2974 outside the United States at (317) 572-3993 or fax (317) 572-4002

Wiley also publishes its books in a variety of electronic formats Some content that appears in print may not be available in electronic formats For more information about Wiley products visit our web site at wwwwileycom

Library of Congress Cataloging-in-Publication Data is available

ISBN 978-0-470-05072-9

Printed in the United States of America

10 9 8 7 6 5 4 3 2 1

In loving memory of Pauline Testa Gerardi

vii

Preface xi

acknowledgments xiii

Part I oVerVIew 1

1 Introduction 3

2 Carbon and Energy Substrates 13

3 Microbial Interactions 19

4 The Facultative Lagoon 35

Part II lower lIfe forms 43

5 Bacteria 45

6 Archaea 59

7 Fungi 65

8 Bioaugmentation 69

9 Purple and Green Sulfur Bacteria 73

10 Pathogens and Disinfection 77

Contents

viii Contents

Part III algae 85

11 Green Algae and Diatoms 87

12 Blue‐Green Algae (Cyanobacteria) 97

13 Algae Alkalinity and pH 105

14 Control Measures for Undesired Algal Growth 111

Part IV HIgHer lIfe forms 121

15 Protozoa 123

16 Metazoa 135

Part V Plants 143

17 Cattails and Bulrushes 145

18 Duckweed and Watermeal 149

19 Weed Problems 153

Part VI large aQUatIc and terrestIal anImals 157

20 Insects 159

21 Fish 167

22 Animal Control 171

Part VII slUdge and odors 175

23 Sludge Accumulation and Disposal 177

24 Reed Beds 181

25 Odors 183

Part VIII monItorIng 189

26 Nitrification 191

27 BOD and TSS 195

Contents ix

28 Monitoring Parameters 199

29 Troubleshooting Notes 203

BIBlIograPHy 209

lIst of aBBreVIatIons 213

glossary 215

sUBJect IndeX 223

genera and sPecIes IndeX 227

xi

Facultative lagoons are commonly used for the treatment of domestic municipal and industrial wastewaters They often are more appropriate for use than conventional forms of secondary treatment in developing countries However as discharge requirements become more stringent a review of the biological chemical and physical interactions in facultative lagoons is critical for the successful operation and compliance with discharge requirements

This book provides operators laboratory technicians and engineers with a review of the critical roles of microscopic and macroscopic organisms that live in and around lagoons Proper design parameters for facultative lagoons have been addressed in numerous texts and other publications including those of federal and state regulatory agencies For that reason this text does not address and enumerate those parameters This book provides biological and chemical approaches to understanding facultative lagoons and includes presentations on algae archaea bacteria crustaceans duckweed aquatic and immature insects grasses rotifers watermeal weeds worms and burrowing ani-mals The text also presents descriptions of the natural processes of wastewater treatment with algae bacteria and other organisms and operational problems that can occur their identification prevention and control

Monitoring and troubleshooting lagoons for acceptable operational conditions process control measures and acceptable effluent quality is not always simple The biological and chemical processes involved in wastewater treatment are numerous and often complex This book is written for lagoon operators who may not have the opportunity or time to obtain the training that they need for reviewing these natural processes

A review of the biological chemical and natural physical treatment processes that occur in aerobic facultative and anaerobic zones of a facultative lagoon is presented Critical biochemical reactions described include aerobic and anaerobic respiration fermentation photosynthesis and changes in pH and alkalinity Control measures for the excessive growth of algae duckweed watermeal and rooted plants as well as control measures for midges and mosquitoes and odors are offered

Preface

xii Preface

Today there is increasing pressure to replace wastewater lagoons with conventional processes This pressure is due to the concern to whether or not facultative lagoons can keep pace with ever‐changing regulations However facultative lagoons can be upgraded and operated to produce an effluent that is comparable to conventional treatment processes This book presents the biological chemical and physical processes that affect wastewater treatment and their corresponding changes in lagoon microbial ecosystems An under-standing of these changes can provide an operator with problem‐solving leverage and improved effluent quality

The Biology and Troubleshooting of Wastewater Lagoons is the eighth book in the Wastewater Microbiology Series by John Wiley amp Sons The series is designed for waste-water personnel and it presents a microbiological review of the significant groups of organisms and their roles in wastewater treatment facilities

Michael H GerardiLinden Pennsylvania

xiii

The author extends his sincere appreciation to David V Daverio VMD Stephanie A Daverio VMD Peter J Sikora VMD technicians and staff at Williamsport West Veterinary Hospital for all that you have done for joLie

Acknowledgments

Part I

Overview

The Biology and Troubleshooting of Facultative Lagoons First Edition Michael H Gerardi copy 2015 John Wiley amp Sons Inc Published 2015 by John Wiley amp Sons Inc

3

1

Lagoons are one of the oldest wastewater treatment systems They consist of inground earthen basins where wastewater is received held for a period of time treated and then discharged (Fig 11) Depending on the composition strength and volume of wastewater to be treated and discharge requirements a predetermined ldquoholdrdquo or retention time for the wastewater is used Although lagoons are simple in design there are many complex biological chemical and physical processes that occur in lagoons There are several different terms for lagoons Many of these terms are used interchangeably These terms include pond oxidation pond polishing pond sewage pond stabilization pond maturation pond and cell Some terms refer to the role of the lagoon in a wastewater treatment process (Table 11)

Lagoons or natural impoundments were used in the United States in the 1920s to capture liquid wastes With increasing knowledge of the wastewater treatment ability of lagoons they were and are used to treat agricultural domestic industrial and municipal wastes and wastewaters

Lagoons became popular in the 1950s Today numerous lagoons and lagoon systems are used especially in rural areas for the treatment of domestic and municipal wastewaters Although performance varies from good to bad lagoons that are properly designed con-structed and operated can produce effluent that meets secondary treatment standards

Lagoons are one of the most popular simplest and least expensive technologies for treating wastewater Lagoons do require relatively large amounts of land For each million gallons per day (MGD) of wastewater approximately 30 acres of lagoon are required for 50 pounds biochemical oxygen demand (BOD) per acre per day Some ldquoonce‐throughrdquo lagoons are as large as 40 MGD

Introduction

4 IntroductIon

Lagoons use natural and energy‐efficient processes to provide low‐cost wastewater treatment and they offer an alternative to more advanced wastewater treatment processes Although lagoons offer many advantages such as reduced maintenance cost when com-pared with other wastewater treatment systems (Table 12) they also have disadvantages such as the requirement for large amounts of land (Table 13)

Lagoons are designed to satisfy a specific site and need The design is based on several factors including type of soil amount of land area required climate quantity and compo-sition of the wastewater to be treated and discharge requirements However lagoon effluent may require additional treatment or polishing to remove pathogens or nutrients

Inuent Aerobic zone

Facultative zone

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

AlgaeEfuent

Figure 11 Facultative lagoon A facultative lagoon has three active microbial zones where wastewater is treated the zones consist of aerobic facultative and anaerobic habitats

Table 11 Terminology for lagoons or ponds

Term Description

Maturation Improves effluent from activated sludge process or trickling filter to tertiary quality principally to reduce the number of pathogens and nutrients

Oxidation Wastewater is purified by sedimentation and aerobic and anaerobic treatmentPolishing Increases the environmental quality of effluent from previous treatmentPrimary Receives raw (unsettled) wastewater and has a sludge layer that is responsible

for methane productionSecondary Receives settled wastewater or effluent from an anaerobic lagoonStabilization An anaerobic facultative or maturation lagoon

Table 12 Advantages of lagoons as compared with more advanced wastewater treatment processes

Can handle intermittent use and shock loads better than other processesInexpensive to constructRelatively small quantity of equipment is neededReduced maintenance costsRelatively simple to operateEffective in removing pathogensEffluent often suitable for irrigation due to high nutrient contentFewer solid‐handling problems

IntroductIon 5

Most lagoons are found in small rural communities Here lagoons often cost less to construct operate and maintain than other wastewater treatment systems Although lagoons require more land than other wastewater treatment systems land is usually more available and affordable in rural areas Because lagoons treat a large variety of wastes they must be properly constructed to prevent soil and groundwater contamination

Wastewater lagoons must be sealed or lined to prevent seepage at the bottom and sidewall of the lagoon to prevent subsurface and groundwater contamination There are several types of liners that are used (i) clay cement and asphalt (ii) synthetic and rubber and (iii) natural Most liners typically perform well for 15 years However premature failure can occur and is usually due to (i) cleaning or dredging operations (ii) membrane puncture (iii) scour of cover material (iv) substandard liner material and (v) weed growth The most commonly used liners for industrial wastewater lagoons include (i) chlorosulfonated polyethylene or Hypalonreg (ii) polypropylene (rPP) (iii) polyvinyl chloride (iv) reinforced linermdashlow density and (v) XR‐5regXR3reg These liners are tolerant of ice buildup and exposure to harsh and prolonged sunlight

Clay liners shrink and swell according to wastewater temperature and wet‐and‐dry conditions However compacted clay liners are susceptible to erosion and vegetative growth in the dike These conditions damage the integrity and strength of the liner and dike

Installation of clay requires proper moisture content and compaction Cement and asphalt liners can crack under temperature change and wet‐and‐dry conditions Synthetic liners are commonly used and usually consist of some type of plastic They require careful installation by an experienced contractor If the liner is properly installed and is not punctured seepage does not occur Synthetic liners are inert and therefore they are often used in lagoons that contain toxic wastes

The clogging of soil pores forms natural liners This occurs due to (i) settled solids (ii) microbial growth and (iii) chemical clogging of the soil due to ionic charges However natural liners tend to be unreliable because these natural modes for forming a natural liner or sealant are dependent on changing characteristics of the wastewater

Large and diverse populations of archaea algae (Fig 12) bacteria and protozoa (Fig 13) are found in lagoons Changes in numbers and dominant groups or species of organisms depend on biotic (biological) and abiotic (chemical and physical) factors (Tables 14 and 15) The most important abiotic factors are (i) composition and strength of the influent (ii) dissolved oxygen (iii) pH (iv) temperature and (v) sunlight

The organisms found in facultative lagoons are more diverse than those found in many other biological wastewater treatment processes including aerated and anaerobic lagoons The

Table 13 Disadvantages of lagoons as compared with more advanced wastewater treatment processes

Less efficient in cold climates than other processesRequire large amounts of landEffluent quality varies with seasonal changes in wastewater temperatureEffluent from facultative lagoons contains algae and may require additional treatment to meet discharge requirementsSeasonal turnover and release of benthic organismsSystem upsets usually result in odor productionIf not properly maintained lagoons can provide a breeding area for midges mosquitoes and other insects

6 IntroductIon

greater diversity of life is due to the highly complex growth conditions in lagoons where algae archaea bacteria crustaceans and rotifers are present in large numbers and perform significant roles Lagoons rely primarily on bacteria to degrade organic (carbonaceous biochemical oxygen demand cBOD) and nitrogenous (nitrogenous biochemical oxygen demand) wastes The biological degradation of wastes is similar to the natural purification of wastes in streams natural ponds and lakes These organisms are components of a food web (Fig 14) where carbon and energy are transferred from one organism to another The interactions between these organisms are complex and they contribute to changes in wastewater chemistry

There are three basic types of lagoons according to microbial activity that are used to degrade organic and nitrogenous wastes The types of lagoons are aerobic (aerated) facultative and anaerobic The biological differences between the lagoons consist of the

(a)

(b)

(c)

(d)

Figure 12 commonly occurring algae in facultative lagoons commonly occurring blue-green algae or cyanobacteria in facultative lagoons include (a) Phormidium (b) Aphanotheca (c) Planktothrix and (d) Aphanizomenon

IntroductIon 7

following (i) the dominant microbes present in the lagoon (Table 16) (ii) the dominant biological reactions that occur in the lagoon and (iii) the depth of the lagoon

Lagoons can be used alone or in combination with other wastewater treatment processes Lagoon systems can consist of a single lagoon or multiple lagoons and may include wastewater recirculation Multiple lagoons can be configured in series or parallel mode of operation (Fig 15)

Paramecium

Strongylidium

Bodo

Vaginicola

Euplotes

ArcellaEpistylis

Pleuromonas

Acineta

Amoeba

Difugia

Opercularia

Figure 13 commonly occurring protozoa in facultative lagoons commonly occurring protozoa in facultative lagoons include the amoebae Arcella Amoeba and Difflugia the flagellates Bodo and Pleuromonas the free-swimming ciliates Paramecium and Strongylidium the crawling ciliates Euplotes the stalk ciliates Epistylis and Opercularia and the suctorian Acineta

8 IntroductIon

Aerobic LAgoon

An aerobic (aerated) lagoon contains dissolved oxygen from surface to bottom and has an average detention time of 3ndash10 days The lagoon usually is 6ndash20 ft deep Oxygen is sup-plied through diffused or mechanical aeration A significant advantage of an aerated lagoon is the small land requirement

Table 14 biotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

Algal growthAvailable nichesBurrowing animalsCarbon dioxide productionCell lysisDenitrificationDominant microbesFood websMethane productionMixed acid productionMutualistic relationshipsNitrificationOxygen productionPhotosynthesisPlant growth (aquatic and terrestrial)Population densitiesPredatorndashprey relationshipsProduction of toxic products including ammonia and hydrogen sulfideSulfur oxidationSulfur reductionSyntrophic relationship

Table 15 Abiotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

AlkalinityEvaporationFlow (quantity and pattern)Ice coverLoadings (cBOD and nBOD)Nutrients (major and minor)pHPrecipitationSurface area for the adsorption of fungi and nitrifying bacteriaTemperatureRetention timeSunlightTotal dissolved solids (TDS)Toxic elements and compoundsVolume of sludge blanketWater currentsWind

cBOD carbonaceous biochemical oxygen demand nBOD nitrogenous biochemical oxygen demand

IntroductIon 9

Nematode

Protozoa Algae

Rotifers

Daphnia

Bacteria

Figure 14 Food web in a facultative lagoon Significant organisms in a facultative lagoon that perform direct or indirect roles in the stabilization of wastes are connected by a food web where each organism is a predator andor prey of another organism

Table 16 Dominant microbes in basic types of lagoons

Lagoon Dominate microbes

Aerobic Facultative anaerobic bacteriaAnaerobic Facultative anaerobic bacteria

MethanogensFacultative Algae

Facultative anaerobic bacteriaMethanogensPhotosynthetic bacteria

Inuent Efuent

Inuent Efuent

Figure 15 Series and parallel modes of operation of multiple lagoons In series mode of operation two or more lagoons are operated in ldquotrain-likerdquo fashion where the influent enters only one lagoon and discharges to the next lagoon In parallel mode of operation influent enters at least two lagoons

The Biology and Troubleshooting of

Facultative Lagoons

WasteWater Microbiology series

Editor

Michael H gerardi

Nitrification and Denitrification in the Activated Sludge ProcessMichael H gerardi

Settleability Problems and Loss of Solids in the Activated Sludge ProcessMichael H gerardi

The Microbiology of Anaerobic DigestersMichael H gerardi

Wastewater PathogensMichael H gerardi and Mel c Zimmerman

Wastewater BacteriaMichael H gerardi

Microscopic Examination of the Activated Sludge ProcessMichael H gerardi

Troubleshooting the Sequencing Batch ReactorMichael H gerardi

The Biology and Troubleshooting of Facultative LagoonsMichael H gerardi

The Biology and Troubleshooting of

Facultative Lagoons

Michael H Gerardi

Illustrations by Brittany Lytle

Copyright copy 2015 by John Wiley amp Sons Inc All rights reserved

Published by John Wiley amp Sons Inc Hoboken New JerseyPublished simultaneously in Canada

No part of this publication may be reproduced stored in a retrieval system or transmitted in any form or by any means electronic mechanical photocopying recording scanning or otherwise except as permitted under Section 107 or 108 of the 1976 United States Copyright Act without either the prior written permission of the Publisher or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center Inc 222 Rosewood Drive Danvers MA 01923 (978) 750-8400 fax (978) 750-4470 or on the web at wwwcopyrightcom Requests to the Publisher for permission should be addressed to the Permissions Department John Wiley amp Sons Inc 111 River Street Hoboken NJ 07030 (201) 748-6011 fax (201) 748-6008 or online at httpwwwwileycomgopermission

Limit of LiabilityDisclaimer of Warranty While the publisher and author have used their best efforts in preparing this book they make no representations or warranties with respect to the accuracy or completeness of the contents of this book and specifically disclaim any implied warranties of merchantability or fitness for a particular purpose No warranty may be created or extended by sales representatives or written sales materials The advice and strategies contained herein may not be suitable for your situation You should consult with a professional where appropriate Neither the publisher nor author shall be liable for any loss of profit or any other commercial damages including but not limited to special incidental consequential or other damages

For general information on our other products and services or for technical support please contact our Customer Care Department within the United States at (800) 762-2974 outside the United States at (317) 572-3993 or fax (317) 572-4002

Wiley also publishes its books in a variety of electronic formats Some content that appears in print may not be available in electronic formats For more information about Wiley products visit our web site at wwwwileycom

Library of Congress Cataloging-in-Publication Data is available

ISBN 978-0-470-05072-9

Printed in the United States of America

10 9 8 7 6 5 4 3 2 1

In loving memory of Pauline Testa Gerardi

vii

Preface xi

acknowledgments xiii

Part I oVerVIew 1

1 Introduction 3

2 Carbon and Energy Substrates 13

3 Microbial Interactions 19

4 The Facultative Lagoon 35

Part II lower lIfe forms 43

5 Bacteria 45

6 Archaea 59

7 Fungi 65

8 Bioaugmentation 69

9 Purple and Green Sulfur Bacteria 73

10 Pathogens and Disinfection 77

Contents

viii Contents

Part III algae 85

11 Green Algae and Diatoms 87

12 Blue‐Green Algae (Cyanobacteria) 97

13 Algae Alkalinity and pH 105

14 Control Measures for Undesired Algal Growth 111

Part IV HIgHer lIfe forms 121

15 Protozoa 123

16 Metazoa 135

Part V Plants 143

17 Cattails and Bulrushes 145

18 Duckweed and Watermeal 149

19 Weed Problems 153

Part VI large aQUatIc and terrestIal anImals 157

20 Insects 159

21 Fish 167

22 Animal Control 171

Part VII slUdge and odors 175

23 Sludge Accumulation and Disposal 177

24 Reed Beds 181

25 Odors 183

Part VIII monItorIng 189

26 Nitrification 191

27 BOD and TSS 195

Contents ix

28 Monitoring Parameters 199

29 Troubleshooting Notes 203

BIBlIograPHy 209

lIst of aBBreVIatIons 213

glossary 215

sUBJect IndeX 223

genera and sPecIes IndeX 227

xi

Facultative lagoons are commonly used for the treatment of domestic municipal and industrial wastewaters They often are more appropriate for use than conventional forms of secondary treatment in developing countries However as discharge requirements become more stringent a review of the biological chemical and physical interactions in facultative lagoons is critical for the successful operation and compliance with discharge requirements

This book provides operators laboratory technicians and engineers with a review of the critical roles of microscopic and macroscopic organisms that live in and around lagoons Proper design parameters for facultative lagoons have been addressed in numerous texts and other publications including those of federal and state regulatory agencies For that reason this text does not address and enumerate those parameters This book provides biological and chemical approaches to understanding facultative lagoons and includes presentations on algae archaea bacteria crustaceans duckweed aquatic and immature insects grasses rotifers watermeal weeds worms and burrowing ani-mals The text also presents descriptions of the natural processes of wastewater treatment with algae bacteria and other organisms and operational problems that can occur their identification prevention and control

Monitoring and troubleshooting lagoons for acceptable operational conditions process control measures and acceptable effluent quality is not always simple The biological and chemical processes involved in wastewater treatment are numerous and often complex This book is written for lagoon operators who may not have the opportunity or time to obtain the training that they need for reviewing these natural processes

A review of the biological chemical and natural physical treatment processes that occur in aerobic facultative and anaerobic zones of a facultative lagoon is presented Critical biochemical reactions described include aerobic and anaerobic respiration fermentation photosynthesis and changes in pH and alkalinity Control measures for the excessive growth of algae duckweed watermeal and rooted plants as well as control measures for midges and mosquitoes and odors are offered

Preface

xii Preface

Today there is increasing pressure to replace wastewater lagoons with conventional processes This pressure is due to the concern to whether or not facultative lagoons can keep pace with ever‐changing regulations However facultative lagoons can be upgraded and operated to produce an effluent that is comparable to conventional treatment processes This book presents the biological chemical and physical processes that affect wastewater treatment and their corresponding changes in lagoon microbial ecosystems An under-standing of these changes can provide an operator with problem‐solving leverage and improved effluent quality

The Biology and Troubleshooting of Wastewater Lagoons is the eighth book in the Wastewater Microbiology Series by John Wiley amp Sons The series is designed for waste-water personnel and it presents a microbiological review of the significant groups of organisms and their roles in wastewater treatment facilities

Michael H GerardiLinden Pennsylvania

xiii

The author extends his sincere appreciation to David V Daverio VMD Stephanie A Daverio VMD Peter J Sikora VMD technicians and staff at Williamsport West Veterinary Hospital for all that you have done for joLie

Acknowledgments

Part I

Overview

The Biology and Troubleshooting of Facultative Lagoons First Edition Michael H Gerardi copy 2015 John Wiley amp Sons Inc Published 2015 by John Wiley amp Sons Inc

3

1

Lagoons are one of the oldest wastewater treatment systems They consist of inground earthen basins where wastewater is received held for a period of time treated and then discharged (Fig 11) Depending on the composition strength and volume of wastewater to be treated and discharge requirements a predetermined ldquoholdrdquo or retention time for the wastewater is used Although lagoons are simple in design there are many complex biological chemical and physical processes that occur in lagoons There are several different terms for lagoons Many of these terms are used interchangeably These terms include pond oxidation pond polishing pond sewage pond stabilization pond maturation pond and cell Some terms refer to the role of the lagoon in a wastewater treatment process (Table 11)

Lagoons or natural impoundments were used in the United States in the 1920s to capture liquid wastes With increasing knowledge of the wastewater treatment ability of lagoons they were and are used to treat agricultural domestic industrial and municipal wastes and wastewaters

Lagoons became popular in the 1950s Today numerous lagoons and lagoon systems are used especially in rural areas for the treatment of domestic and municipal wastewaters Although performance varies from good to bad lagoons that are properly designed con-structed and operated can produce effluent that meets secondary treatment standards

Lagoons are one of the most popular simplest and least expensive technologies for treating wastewater Lagoons do require relatively large amounts of land For each million gallons per day (MGD) of wastewater approximately 30 acres of lagoon are required for 50 pounds biochemical oxygen demand (BOD) per acre per day Some ldquoonce‐throughrdquo lagoons are as large as 40 MGD

Introduction

4 IntroductIon

Lagoons use natural and energy‐efficient processes to provide low‐cost wastewater treatment and they offer an alternative to more advanced wastewater treatment processes Although lagoons offer many advantages such as reduced maintenance cost when com-pared with other wastewater treatment systems (Table 12) they also have disadvantages such as the requirement for large amounts of land (Table 13)

Lagoons are designed to satisfy a specific site and need The design is based on several factors including type of soil amount of land area required climate quantity and compo-sition of the wastewater to be treated and discharge requirements However lagoon effluent may require additional treatment or polishing to remove pathogens or nutrients

Inuent Aerobic zone

Facultative zone

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

AlgaeEfuent

Figure 11 Facultative lagoon A facultative lagoon has three active microbial zones where wastewater is treated the zones consist of aerobic facultative and anaerobic habitats

Table 11 Terminology for lagoons or ponds

Term Description

Maturation Improves effluent from activated sludge process or trickling filter to tertiary quality principally to reduce the number of pathogens and nutrients

Oxidation Wastewater is purified by sedimentation and aerobic and anaerobic treatmentPolishing Increases the environmental quality of effluent from previous treatmentPrimary Receives raw (unsettled) wastewater and has a sludge layer that is responsible

for methane productionSecondary Receives settled wastewater or effluent from an anaerobic lagoonStabilization An anaerobic facultative or maturation lagoon

Table 12 Advantages of lagoons as compared with more advanced wastewater treatment processes

Can handle intermittent use and shock loads better than other processesInexpensive to constructRelatively small quantity of equipment is neededReduced maintenance costsRelatively simple to operateEffective in removing pathogensEffluent often suitable for irrigation due to high nutrient contentFewer solid‐handling problems

IntroductIon 5

Most lagoons are found in small rural communities Here lagoons often cost less to construct operate and maintain than other wastewater treatment systems Although lagoons require more land than other wastewater treatment systems land is usually more available and affordable in rural areas Because lagoons treat a large variety of wastes they must be properly constructed to prevent soil and groundwater contamination

Wastewater lagoons must be sealed or lined to prevent seepage at the bottom and sidewall of the lagoon to prevent subsurface and groundwater contamination There are several types of liners that are used (i) clay cement and asphalt (ii) synthetic and rubber and (iii) natural Most liners typically perform well for 15 years However premature failure can occur and is usually due to (i) cleaning or dredging operations (ii) membrane puncture (iii) scour of cover material (iv) substandard liner material and (v) weed growth The most commonly used liners for industrial wastewater lagoons include (i) chlorosulfonated polyethylene or Hypalonreg (ii) polypropylene (rPP) (iii) polyvinyl chloride (iv) reinforced linermdashlow density and (v) XR‐5regXR3reg These liners are tolerant of ice buildup and exposure to harsh and prolonged sunlight

Clay liners shrink and swell according to wastewater temperature and wet‐and‐dry conditions However compacted clay liners are susceptible to erosion and vegetative growth in the dike These conditions damage the integrity and strength of the liner and dike

Installation of clay requires proper moisture content and compaction Cement and asphalt liners can crack under temperature change and wet‐and‐dry conditions Synthetic liners are commonly used and usually consist of some type of plastic They require careful installation by an experienced contractor If the liner is properly installed and is not punctured seepage does not occur Synthetic liners are inert and therefore they are often used in lagoons that contain toxic wastes

The clogging of soil pores forms natural liners This occurs due to (i) settled solids (ii) microbial growth and (iii) chemical clogging of the soil due to ionic charges However natural liners tend to be unreliable because these natural modes for forming a natural liner or sealant are dependent on changing characteristics of the wastewater

Large and diverse populations of archaea algae (Fig 12) bacteria and protozoa (Fig 13) are found in lagoons Changes in numbers and dominant groups or species of organisms depend on biotic (biological) and abiotic (chemical and physical) factors (Tables 14 and 15) The most important abiotic factors are (i) composition and strength of the influent (ii) dissolved oxygen (iii) pH (iv) temperature and (v) sunlight

The organisms found in facultative lagoons are more diverse than those found in many other biological wastewater treatment processes including aerated and anaerobic lagoons The

Table 13 Disadvantages of lagoons as compared with more advanced wastewater treatment processes

Less efficient in cold climates than other processesRequire large amounts of landEffluent quality varies with seasonal changes in wastewater temperatureEffluent from facultative lagoons contains algae and may require additional treatment to meet discharge requirementsSeasonal turnover and release of benthic organismsSystem upsets usually result in odor productionIf not properly maintained lagoons can provide a breeding area for midges mosquitoes and other insects

6 IntroductIon

greater diversity of life is due to the highly complex growth conditions in lagoons where algae archaea bacteria crustaceans and rotifers are present in large numbers and perform significant roles Lagoons rely primarily on bacteria to degrade organic (carbonaceous biochemical oxygen demand cBOD) and nitrogenous (nitrogenous biochemical oxygen demand) wastes The biological degradation of wastes is similar to the natural purification of wastes in streams natural ponds and lakes These organisms are components of a food web (Fig 14) where carbon and energy are transferred from one organism to another The interactions between these organisms are complex and they contribute to changes in wastewater chemistry

There are three basic types of lagoons according to microbial activity that are used to degrade organic and nitrogenous wastes The types of lagoons are aerobic (aerated) facultative and anaerobic The biological differences between the lagoons consist of the

(a)

(b)

(c)

(d)

Figure 12 commonly occurring algae in facultative lagoons commonly occurring blue-green algae or cyanobacteria in facultative lagoons include (a) Phormidium (b) Aphanotheca (c) Planktothrix and (d) Aphanizomenon

IntroductIon 7

following (i) the dominant microbes present in the lagoon (Table 16) (ii) the dominant biological reactions that occur in the lagoon and (iii) the depth of the lagoon

Lagoons can be used alone or in combination with other wastewater treatment processes Lagoon systems can consist of a single lagoon or multiple lagoons and may include wastewater recirculation Multiple lagoons can be configured in series or parallel mode of operation (Fig 15)

Paramecium

Strongylidium

Bodo

Vaginicola

Euplotes

ArcellaEpistylis

Pleuromonas

Acineta

Amoeba

Difugia

Opercularia

Figure 13 commonly occurring protozoa in facultative lagoons commonly occurring protozoa in facultative lagoons include the amoebae Arcella Amoeba and Difflugia the flagellates Bodo and Pleuromonas the free-swimming ciliates Paramecium and Strongylidium the crawling ciliates Euplotes the stalk ciliates Epistylis and Opercularia and the suctorian Acineta

8 IntroductIon

Aerobic LAgoon

An aerobic (aerated) lagoon contains dissolved oxygen from surface to bottom and has an average detention time of 3ndash10 days The lagoon usually is 6ndash20 ft deep Oxygen is sup-plied through diffused or mechanical aeration A significant advantage of an aerated lagoon is the small land requirement

Table 14 biotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

Algal growthAvailable nichesBurrowing animalsCarbon dioxide productionCell lysisDenitrificationDominant microbesFood websMethane productionMixed acid productionMutualistic relationshipsNitrificationOxygen productionPhotosynthesisPlant growth (aquatic and terrestrial)Population densitiesPredatorndashprey relationshipsProduction of toxic products including ammonia and hydrogen sulfideSulfur oxidationSulfur reductionSyntrophic relationship

Table 15 Abiotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

AlkalinityEvaporationFlow (quantity and pattern)Ice coverLoadings (cBOD and nBOD)Nutrients (major and minor)pHPrecipitationSurface area for the adsorption of fungi and nitrifying bacteriaTemperatureRetention timeSunlightTotal dissolved solids (TDS)Toxic elements and compoundsVolume of sludge blanketWater currentsWind

cBOD carbonaceous biochemical oxygen demand nBOD nitrogenous biochemical oxygen demand

IntroductIon 9

Nematode

Protozoa Algae

Rotifers

Daphnia

Bacteria

Figure 14 Food web in a facultative lagoon Significant organisms in a facultative lagoon that perform direct or indirect roles in the stabilization of wastes are connected by a food web where each organism is a predator andor prey of another organism

Table 16 Dominant microbes in basic types of lagoons

Lagoon Dominate microbes

Aerobic Facultative anaerobic bacteriaAnaerobic Facultative anaerobic bacteria

MethanogensFacultative Algae

Facultative anaerobic bacteriaMethanogensPhotosynthetic bacteria

Inuent Efuent

Inuent Efuent

Figure 15 Series and parallel modes of operation of multiple lagoons In series mode of operation two or more lagoons are operated in ldquotrain-likerdquo fashion where the influent enters only one lagoon and discharges to the next lagoon In parallel mode of operation influent enters at least two lagoons

WasteWater Microbiology series

Editor

Michael H gerardi

Nitrification and Denitrification in the Activated Sludge ProcessMichael H gerardi

Settleability Problems and Loss of Solids in the Activated Sludge ProcessMichael H gerardi

The Microbiology of Anaerobic DigestersMichael H gerardi

Wastewater PathogensMichael H gerardi and Mel c Zimmerman

Wastewater BacteriaMichael H gerardi

Microscopic Examination of the Activated Sludge ProcessMichael H gerardi

Troubleshooting the Sequencing Batch ReactorMichael H gerardi

The Biology and Troubleshooting of Facultative LagoonsMichael H gerardi

The Biology and Troubleshooting of

Facultative Lagoons

Michael H Gerardi

Illustrations by Brittany Lytle

Copyright copy 2015 by John Wiley amp Sons Inc All rights reserved

Published by John Wiley amp Sons Inc Hoboken New JerseyPublished simultaneously in Canada

No part of this publication may be reproduced stored in a retrieval system or transmitted in any form or by any means electronic mechanical photocopying recording scanning or otherwise except as permitted under Section 107 or 108 of the 1976 United States Copyright Act without either the prior written permission of the Publisher or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center Inc 222 Rosewood Drive Danvers MA 01923 (978) 750-8400 fax (978) 750-4470 or on the web at wwwcopyrightcom Requests to the Publisher for permission should be addressed to the Permissions Department John Wiley amp Sons Inc 111 River Street Hoboken NJ 07030 (201) 748-6011 fax (201) 748-6008 or online at httpwwwwileycomgopermission

Limit of LiabilityDisclaimer of Warranty While the publisher and author have used their best efforts in preparing this book they make no representations or warranties with respect to the accuracy or completeness of the contents of this book and specifically disclaim any implied warranties of merchantability or fitness for a particular purpose No warranty may be created or extended by sales representatives or written sales materials The advice and strategies contained herein may not be suitable for your situation You should consult with a professional where appropriate Neither the publisher nor author shall be liable for any loss of profit or any other commercial damages including but not limited to special incidental consequential or other damages

For general information on our other products and services or for technical support please contact our Customer Care Department within the United States at (800) 762-2974 outside the United States at (317) 572-3993 or fax (317) 572-4002

Wiley also publishes its books in a variety of electronic formats Some content that appears in print may not be available in electronic formats For more information about Wiley products visit our web site at wwwwileycom

Library of Congress Cataloging-in-Publication Data is available

ISBN 978-0-470-05072-9

Printed in the United States of America

10 9 8 7 6 5 4 3 2 1

In loving memory of Pauline Testa Gerardi

vii

Preface xi

acknowledgments xiii

Part I oVerVIew 1

1 Introduction 3

2 Carbon and Energy Substrates 13

3 Microbial Interactions 19

4 The Facultative Lagoon 35

Part II lower lIfe forms 43

5 Bacteria 45

6 Archaea 59

7 Fungi 65

8 Bioaugmentation 69

9 Purple and Green Sulfur Bacteria 73

10 Pathogens and Disinfection 77

Contents

viii Contents

Part III algae 85

11 Green Algae and Diatoms 87

12 Blue‐Green Algae (Cyanobacteria) 97

13 Algae Alkalinity and pH 105

14 Control Measures for Undesired Algal Growth 111

Part IV HIgHer lIfe forms 121

15 Protozoa 123

16 Metazoa 135

Part V Plants 143

17 Cattails and Bulrushes 145

18 Duckweed and Watermeal 149

19 Weed Problems 153

Part VI large aQUatIc and terrestIal anImals 157

20 Insects 159

21 Fish 167

22 Animal Control 171

Part VII slUdge and odors 175

23 Sludge Accumulation and Disposal 177

24 Reed Beds 181

25 Odors 183

Part VIII monItorIng 189

26 Nitrification 191

27 BOD and TSS 195

Contents ix

28 Monitoring Parameters 199

29 Troubleshooting Notes 203

BIBlIograPHy 209

lIst of aBBreVIatIons 213

glossary 215

sUBJect IndeX 223

genera and sPecIes IndeX 227

xi

Facultative lagoons are commonly used for the treatment of domestic municipal and industrial wastewaters They often are more appropriate for use than conventional forms of secondary treatment in developing countries However as discharge requirements become more stringent a review of the biological chemical and physical interactions in facultative lagoons is critical for the successful operation and compliance with discharge requirements

This book provides operators laboratory technicians and engineers with a review of the critical roles of microscopic and macroscopic organisms that live in and around lagoons Proper design parameters for facultative lagoons have been addressed in numerous texts and other publications including those of federal and state regulatory agencies For that reason this text does not address and enumerate those parameters This book provides biological and chemical approaches to understanding facultative lagoons and includes presentations on algae archaea bacteria crustaceans duckweed aquatic and immature insects grasses rotifers watermeal weeds worms and burrowing ani-mals The text also presents descriptions of the natural processes of wastewater treatment with algae bacteria and other organisms and operational problems that can occur their identification prevention and control

Monitoring and troubleshooting lagoons for acceptable operational conditions process control measures and acceptable effluent quality is not always simple The biological and chemical processes involved in wastewater treatment are numerous and often complex This book is written for lagoon operators who may not have the opportunity or time to obtain the training that they need for reviewing these natural processes

A review of the biological chemical and natural physical treatment processes that occur in aerobic facultative and anaerobic zones of a facultative lagoon is presented Critical biochemical reactions described include aerobic and anaerobic respiration fermentation photosynthesis and changes in pH and alkalinity Control measures for the excessive growth of algae duckweed watermeal and rooted plants as well as control measures for midges and mosquitoes and odors are offered

Preface

xii Preface

Today there is increasing pressure to replace wastewater lagoons with conventional processes This pressure is due to the concern to whether or not facultative lagoons can keep pace with ever‐changing regulations However facultative lagoons can be upgraded and operated to produce an effluent that is comparable to conventional treatment processes This book presents the biological chemical and physical processes that affect wastewater treatment and their corresponding changes in lagoon microbial ecosystems An under-standing of these changes can provide an operator with problem‐solving leverage and improved effluent quality

The Biology and Troubleshooting of Wastewater Lagoons is the eighth book in the Wastewater Microbiology Series by John Wiley amp Sons The series is designed for waste-water personnel and it presents a microbiological review of the significant groups of organisms and their roles in wastewater treatment facilities

Michael H GerardiLinden Pennsylvania

xiii

The author extends his sincere appreciation to David V Daverio VMD Stephanie A Daverio VMD Peter J Sikora VMD technicians and staff at Williamsport West Veterinary Hospital for all that you have done for joLie

Acknowledgments

Part I

Overview

The Biology and Troubleshooting of Facultative Lagoons First Edition Michael H Gerardi copy 2015 John Wiley amp Sons Inc Published 2015 by John Wiley amp Sons Inc

3

1

Lagoons are one of the oldest wastewater treatment systems They consist of inground earthen basins where wastewater is received held for a period of time treated and then discharged (Fig 11) Depending on the composition strength and volume of wastewater to be treated and discharge requirements a predetermined ldquoholdrdquo or retention time for the wastewater is used Although lagoons are simple in design there are many complex biological chemical and physical processes that occur in lagoons There are several different terms for lagoons Many of these terms are used interchangeably These terms include pond oxidation pond polishing pond sewage pond stabilization pond maturation pond and cell Some terms refer to the role of the lagoon in a wastewater treatment process (Table 11)

Lagoons or natural impoundments were used in the United States in the 1920s to capture liquid wastes With increasing knowledge of the wastewater treatment ability of lagoons they were and are used to treat agricultural domestic industrial and municipal wastes and wastewaters

Lagoons became popular in the 1950s Today numerous lagoons and lagoon systems are used especially in rural areas for the treatment of domestic and municipal wastewaters Although performance varies from good to bad lagoons that are properly designed con-structed and operated can produce effluent that meets secondary treatment standards

Lagoons are one of the most popular simplest and least expensive technologies for treating wastewater Lagoons do require relatively large amounts of land For each million gallons per day (MGD) of wastewater approximately 30 acres of lagoon are required for 50 pounds biochemical oxygen demand (BOD) per acre per day Some ldquoonce‐throughrdquo lagoons are as large as 40 MGD

Introduction

4 IntroductIon

Lagoons use natural and energy‐efficient processes to provide low‐cost wastewater treatment and they offer an alternative to more advanced wastewater treatment processes Although lagoons offer many advantages such as reduced maintenance cost when com-pared with other wastewater treatment systems (Table 12) they also have disadvantages such as the requirement for large amounts of land (Table 13)

Lagoons are designed to satisfy a specific site and need The design is based on several factors including type of soil amount of land area required climate quantity and compo-sition of the wastewater to be treated and discharge requirements However lagoon effluent may require additional treatment or polishing to remove pathogens or nutrients

Inuent Aerobic zone

Facultative zone

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

AlgaeEfuent

Figure 11 Facultative lagoon A facultative lagoon has three active microbial zones where wastewater is treated the zones consist of aerobic facultative and anaerobic habitats

Table 11 Terminology for lagoons or ponds

Term Description

Maturation Improves effluent from activated sludge process or trickling filter to tertiary quality principally to reduce the number of pathogens and nutrients

Oxidation Wastewater is purified by sedimentation and aerobic and anaerobic treatmentPolishing Increases the environmental quality of effluent from previous treatmentPrimary Receives raw (unsettled) wastewater and has a sludge layer that is responsible

for methane productionSecondary Receives settled wastewater or effluent from an anaerobic lagoonStabilization An anaerobic facultative or maturation lagoon

Table 12 Advantages of lagoons as compared with more advanced wastewater treatment processes

Can handle intermittent use and shock loads better than other processesInexpensive to constructRelatively small quantity of equipment is neededReduced maintenance costsRelatively simple to operateEffective in removing pathogensEffluent often suitable for irrigation due to high nutrient contentFewer solid‐handling problems

IntroductIon 5

Most lagoons are found in small rural communities Here lagoons often cost less to construct operate and maintain than other wastewater treatment systems Although lagoons require more land than other wastewater treatment systems land is usually more available and affordable in rural areas Because lagoons treat a large variety of wastes they must be properly constructed to prevent soil and groundwater contamination

Wastewater lagoons must be sealed or lined to prevent seepage at the bottom and sidewall of the lagoon to prevent subsurface and groundwater contamination There are several types of liners that are used (i) clay cement and asphalt (ii) synthetic and rubber and (iii) natural Most liners typically perform well for 15 years However premature failure can occur and is usually due to (i) cleaning or dredging operations (ii) membrane puncture (iii) scour of cover material (iv) substandard liner material and (v) weed growth The most commonly used liners for industrial wastewater lagoons include (i) chlorosulfonated polyethylene or Hypalonreg (ii) polypropylene (rPP) (iii) polyvinyl chloride (iv) reinforced linermdashlow density and (v) XR‐5regXR3reg These liners are tolerant of ice buildup and exposure to harsh and prolonged sunlight

Clay liners shrink and swell according to wastewater temperature and wet‐and‐dry conditions However compacted clay liners are susceptible to erosion and vegetative growth in the dike These conditions damage the integrity and strength of the liner and dike

Installation of clay requires proper moisture content and compaction Cement and asphalt liners can crack under temperature change and wet‐and‐dry conditions Synthetic liners are commonly used and usually consist of some type of plastic They require careful installation by an experienced contractor If the liner is properly installed and is not punctured seepage does not occur Synthetic liners are inert and therefore they are often used in lagoons that contain toxic wastes

The clogging of soil pores forms natural liners This occurs due to (i) settled solids (ii) microbial growth and (iii) chemical clogging of the soil due to ionic charges However natural liners tend to be unreliable because these natural modes for forming a natural liner or sealant are dependent on changing characteristics of the wastewater

Large and diverse populations of archaea algae (Fig 12) bacteria and protozoa (Fig 13) are found in lagoons Changes in numbers and dominant groups or species of organisms depend on biotic (biological) and abiotic (chemical and physical) factors (Tables 14 and 15) The most important abiotic factors are (i) composition and strength of the influent (ii) dissolved oxygen (iii) pH (iv) temperature and (v) sunlight

The organisms found in facultative lagoons are more diverse than those found in many other biological wastewater treatment processes including aerated and anaerobic lagoons The

Table 13 Disadvantages of lagoons as compared with more advanced wastewater treatment processes

Less efficient in cold climates than other processesRequire large amounts of landEffluent quality varies with seasonal changes in wastewater temperatureEffluent from facultative lagoons contains algae and may require additional treatment to meet discharge requirementsSeasonal turnover and release of benthic organismsSystem upsets usually result in odor productionIf not properly maintained lagoons can provide a breeding area for midges mosquitoes and other insects

6 IntroductIon

greater diversity of life is due to the highly complex growth conditions in lagoons where algae archaea bacteria crustaceans and rotifers are present in large numbers and perform significant roles Lagoons rely primarily on bacteria to degrade organic (carbonaceous biochemical oxygen demand cBOD) and nitrogenous (nitrogenous biochemical oxygen demand) wastes The biological degradation of wastes is similar to the natural purification of wastes in streams natural ponds and lakes These organisms are components of a food web (Fig 14) where carbon and energy are transferred from one organism to another The interactions between these organisms are complex and they contribute to changes in wastewater chemistry

There are three basic types of lagoons according to microbial activity that are used to degrade organic and nitrogenous wastes The types of lagoons are aerobic (aerated) facultative and anaerobic The biological differences between the lagoons consist of the

(a)

(b)

(c)

(d)

Figure 12 commonly occurring algae in facultative lagoons commonly occurring blue-green algae or cyanobacteria in facultative lagoons include (a) Phormidium (b) Aphanotheca (c) Planktothrix and (d) Aphanizomenon

IntroductIon 7

following (i) the dominant microbes present in the lagoon (Table 16) (ii) the dominant biological reactions that occur in the lagoon and (iii) the depth of the lagoon

Lagoons can be used alone or in combination with other wastewater treatment processes Lagoon systems can consist of a single lagoon or multiple lagoons and may include wastewater recirculation Multiple lagoons can be configured in series or parallel mode of operation (Fig 15)

Paramecium

Strongylidium

Bodo

Vaginicola

Euplotes

ArcellaEpistylis

Pleuromonas

Acineta

Amoeba

Difugia

Opercularia

Figure 13 commonly occurring protozoa in facultative lagoons commonly occurring protozoa in facultative lagoons include the amoebae Arcella Amoeba and Difflugia the flagellates Bodo and Pleuromonas the free-swimming ciliates Paramecium and Strongylidium the crawling ciliates Euplotes the stalk ciliates Epistylis and Opercularia and the suctorian Acineta

8 IntroductIon

Aerobic LAgoon

An aerobic (aerated) lagoon contains dissolved oxygen from surface to bottom and has an average detention time of 3ndash10 days The lagoon usually is 6ndash20 ft deep Oxygen is sup-plied through diffused or mechanical aeration A significant advantage of an aerated lagoon is the small land requirement

Table 14 biotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

Algal growthAvailable nichesBurrowing animalsCarbon dioxide productionCell lysisDenitrificationDominant microbesFood websMethane productionMixed acid productionMutualistic relationshipsNitrificationOxygen productionPhotosynthesisPlant growth (aquatic and terrestrial)Population densitiesPredatorndashprey relationshipsProduction of toxic products including ammonia and hydrogen sulfideSulfur oxidationSulfur reductionSyntrophic relationship

Table 15 Abiotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

AlkalinityEvaporationFlow (quantity and pattern)Ice coverLoadings (cBOD and nBOD)Nutrients (major and minor)pHPrecipitationSurface area for the adsorption of fungi and nitrifying bacteriaTemperatureRetention timeSunlightTotal dissolved solids (TDS)Toxic elements and compoundsVolume of sludge blanketWater currentsWind

cBOD carbonaceous biochemical oxygen demand nBOD nitrogenous biochemical oxygen demand

IntroductIon 9

Nematode

Protozoa Algae

Rotifers

Daphnia

Bacteria

Figure 14 Food web in a facultative lagoon Significant organisms in a facultative lagoon that perform direct or indirect roles in the stabilization of wastes are connected by a food web where each organism is a predator andor prey of another organism

Table 16 Dominant microbes in basic types of lagoons

Lagoon Dominate microbes

Aerobic Facultative anaerobic bacteriaAnaerobic Facultative anaerobic bacteria

MethanogensFacultative Algae

Facultative anaerobic bacteriaMethanogensPhotosynthetic bacteria

Inuent Efuent

Inuent Efuent

Figure 15 Series and parallel modes of operation of multiple lagoons In series mode of operation two or more lagoons are operated in ldquotrain-likerdquo fashion where the influent enters only one lagoon and discharges to the next lagoon In parallel mode of operation influent enters at least two lagoons

The Biology and Troubleshooting of

Facultative Lagoons

Michael H Gerardi

Illustrations by Brittany Lytle

Copyright copy 2015 by John Wiley amp Sons Inc All rights reserved

Published by John Wiley amp Sons Inc Hoboken New JerseyPublished simultaneously in Canada

No part of this publication may be reproduced stored in a retrieval system or transmitted in any form or by any means electronic mechanical photocopying recording scanning or otherwise except as permitted under Section 107 or 108 of the 1976 United States Copyright Act without either the prior written permission of the Publisher or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center Inc 222 Rosewood Drive Danvers MA 01923 (978) 750-8400 fax (978) 750-4470 or on the web at wwwcopyrightcom Requests to the Publisher for permission should be addressed to the Permissions Department John Wiley amp Sons Inc 111 River Street Hoboken NJ 07030 (201) 748-6011 fax (201) 748-6008 or online at httpwwwwileycomgopermission

Limit of LiabilityDisclaimer of Warranty While the publisher and author have used their best efforts in preparing this book they make no representations or warranties with respect to the accuracy or completeness of the contents of this book and specifically disclaim any implied warranties of merchantability or fitness for a particular purpose No warranty may be created or extended by sales representatives or written sales materials The advice and strategies contained herein may not be suitable for your situation You should consult with a professional where appropriate Neither the publisher nor author shall be liable for any loss of profit or any other commercial damages including but not limited to special incidental consequential or other damages

For general information on our other products and services or for technical support please contact our Customer Care Department within the United States at (800) 762-2974 outside the United States at (317) 572-3993 or fax (317) 572-4002

Wiley also publishes its books in a variety of electronic formats Some content that appears in print may not be available in electronic formats For more information about Wiley products visit our web site at wwwwileycom

Library of Congress Cataloging-in-Publication Data is available

ISBN 978-0-470-05072-9

Printed in the United States of America

10 9 8 7 6 5 4 3 2 1

In loving memory of Pauline Testa Gerardi

vii

Preface xi

acknowledgments xiii

Part I oVerVIew 1

1 Introduction 3

2 Carbon and Energy Substrates 13

3 Microbial Interactions 19

4 The Facultative Lagoon 35

Part II lower lIfe forms 43

5 Bacteria 45

6 Archaea 59

7 Fungi 65

8 Bioaugmentation 69

9 Purple and Green Sulfur Bacteria 73

10 Pathogens and Disinfection 77

Contents

viii Contents

Part III algae 85

11 Green Algae and Diatoms 87

12 Blue‐Green Algae (Cyanobacteria) 97

13 Algae Alkalinity and pH 105

14 Control Measures for Undesired Algal Growth 111

Part IV HIgHer lIfe forms 121

15 Protozoa 123

16 Metazoa 135

Part V Plants 143

17 Cattails and Bulrushes 145

18 Duckweed and Watermeal 149

19 Weed Problems 153

Part VI large aQUatIc and terrestIal anImals 157

20 Insects 159

21 Fish 167

22 Animal Control 171

Part VII slUdge and odors 175

23 Sludge Accumulation and Disposal 177

24 Reed Beds 181

25 Odors 183

Part VIII monItorIng 189

26 Nitrification 191

27 BOD and TSS 195

Contents ix

28 Monitoring Parameters 199

29 Troubleshooting Notes 203

BIBlIograPHy 209

lIst of aBBreVIatIons 213

glossary 215

sUBJect IndeX 223

genera and sPecIes IndeX 227

xi

Facultative lagoons are commonly used for the treatment of domestic municipal and industrial wastewaters They often are more appropriate for use than conventional forms of secondary treatment in developing countries However as discharge requirements become more stringent a review of the biological chemical and physical interactions in facultative lagoons is critical for the successful operation and compliance with discharge requirements

This book provides operators laboratory technicians and engineers with a review of the critical roles of microscopic and macroscopic organisms that live in and around lagoons Proper design parameters for facultative lagoons have been addressed in numerous texts and other publications including those of federal and state regulatory agencies For that reason this text does not address and enumerate those parameters This book provides biological and chemical approaches to understanding facultative lagoons and includes presentations on algae archaea bacteria crustaceans duckweed aquatic and immature insects grasses rotifers watermeal weeds worms and burrowing ani-mals The text also presents descriptions of the natural processes of wastewater treatment with algae bacteria and other organisms and operational problems that can occur their identification prevention and control

Monitoring and troubleshooting lagoons for acceptable operational conditions process control measures and acceptable effluent quality is not always simple The biological and chemical processes involved in wastewater treatment are numerous and often complex This book is written for lagoon operators who may not have the opportunity or time to obtain the training that they need for reviewing these natural processes

A review of the biological chemical and natural physical treatment processes that occur in aerobic facultative and anaerobic zones of a facultative lagoon is presented Critical biochemical reactions described include aerobic and anaerobic respiration fermentation photosynthesis and changes in pH and alkalinity Control measures for the excessive growth of algae duckweed watermeal and rooted plants as well as control measures for midges and mosquitoes and odors are offered

Preface

xii Preface

Today there is increasing pressure to replace wastewater lagoons with conventional processes This pressure is due to the concern to whether or not facultative lagoons can keep pace with ever‐changing regulations However facultative lagoons can be upgraded and operated to produce an effluent that is comparable to conventional treatment processes This book presents the biological chemical and physical processes that affect wastewater treatment and their corresponding changes in lagoon microbial ecosystems An under-standing of these changes can provide an operator with problem‐solving leverage and improved effluent quality

The Biology and Troubleshooting of Wastewater Lagoons is the eighth book in the Wastewater Microbiology Series by John Wiley amp Sons The series is designed for waste-water personnel and it presents a microbiological review of the significant groups of organisms and their roles in wastewater treatment facilities

Michael H GerardiLinden Pennsylvania

xiii

The author extends his sincere appreciation to David V Daverio VMD Stephanie A Daverio VMD Peter J Sikora VMD technicians and staff at Williamsport West Veterinary Hospital for all that you have done for joLie

Acknowledgments

Part I

Overview

The Biology and Troubleshooting of Facultative Lagoons First Edition Michael H Gerardi copy 2015 John Wiley amp Sons Inc Published 2015 by John Wiley amp Sons Inc

3

1

Lagoons are one of the oldest wastewater treatment systems They consist of inground earthen basins where wastewater is received held for a period of time treated and then discharged (Fig 11) Depending on the composition strength and volume of wastewater to be treated and discharge requirements a predetermined ldquoholdrdquo or retention time for the wastewater is used Although lagoons are simple in design there are many complex biological chemical and physical processes that occur in lagoons There are several different terms for lagoons Many of these terms are used interchangeably These terms include pond oxidation pond polishing pond sewage pond stabilization pond maturation pond and cell Some terms refer to the role of the lagoon in a wastewater treatment process (Table 11)

Lagoons or natural impoundments were used in the United States in the 1920s to capture liquid wastes With increasing knowledge of the wastewater treatment ability of lagoons they were and are used to treat agricultural domestic industrial and municipal wastes and wastewaters

Lagoons became popular in the 1950s Today numerous lagoons and lagoon systems are used especially in rural areas for the treatment of domestic and municipal wastewaters Although performance varies from good to bad lagoons that are properly designed con-structed and operated can produce effluent that meets secondary treatment standards

Lagoons are one of the most popular simplest and least expensive technologies for treating wastewater Lagoons do require relatively large amounts of land For each million gallons per day (MGD) of wastewater approximately 30 acres of lagoon are required for 50 pounds biochemical oxygen demand (BOD) per acre per day Some ldquoonce‐throughrdquo lagoons are as large as 40 MGD

Introduction

4 IntroductIon

Lagoons use natural and energy‐efficient processes to provide low‐cost wastewater treatment and they offer an alternative to more advanced wastewater treatment processes Although lagoons offer many advantages such as reduced maintenance cost when com-pared with other wastewater treatment systems (Table 12) they also have disadvantages such as the requirement for large amounts of land (Table 13)

Lagoons are designed to satisfy a specific site and need The design is based on several factors including type of soil amount of land area required climate quantity and compo-sition of the wastewater to be treated and discharge requirements However lagoon effluent may require additional treatment or polishing to remove pathogens or nutrients

Inuent Aerobic zone

Facultative zone

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

AlgaeEfuent

Figure 11 Facultative lagoon A facultative lagoon has three active microbial zones where wastewater is treated the zones consist of aerobic facultative and anaerobic habitats

Table 11 Terminology for lagoons or ponds

Term Description

Maturation Improves effluent from activated sludge process or trickling filter to tertiary quality principally to reduce the number of pathogens and nutrients

Oxidation Wastewater is purified by sedimentation and aerobic and anaerobic treatmentPolishing Increases the environmental quality of effluent from previous treatmentPrimary Receives raw (unsettled) wastewater and has a sludge layer that is responsible

for methane productionSecondary Receives settled wastewater or effluent from an anaerobic lagoonStabilization An anaerobic facultative or maturation lagoon

Table 12 Advantages of lagoons as compared with more advanced wastewater treatment processes

Can handle intermittent use and shock loads better than other processesInexpensive to constructRelatively small quantity of equipment is neededReduced maintenance costsRelatively simple to operateEffective in removing pathogensEffluent often suitable for irrigation due to high nutrient contentFewer solid‐handling problems

IntroductIon 5

Most lagoons are found in small rural communities Here lagoons often cost less to construct operate and maintain than other wastewater treatment systems Although lagoons require more land than other wastewater treatment systems land is usually more available and affordable in rural areas Because lagoons treat a large variety of wastes they must be properly constructed to prevent soil and groundwater contamination

Wastewater lagoons must be sealed or lined to prevent seepage at the bottom and sidewall of the lagoon to prevent subsurface and groundwater contamination There are several types of liners that are used (i) clay cement and asphalt (ii) synthetic and rubber and (iii) natural Most liners typically perform well for 15 years However premature failure can occur and is usually due to (i) cleaning or dredging operations (ii) membrane puncture (iii) scour of cover material (iv) substandard liner material and (v) weed growth The most commonly used liners for industrial wastewater lagoons include (i) chlorosulfonated polyethylene or Hypalonreg (ii) polypropylene (rPP) (iii) polyvinyl chloride (iv) reinforced linermdashlow density and (v) XR‐5regXR3reg These liners are tolerant of ice buildup and exposure to harsh and prolonged sunlight

Clay liners shrink and swell according to wastewater temperature and wet‐and‐dry conditions However compacted clay liners are susceptible to erosion and vegetative growth in the dike These conditions damage the integrity and strength of the liner and dike

Installation of clay requires proper moisture content and compaction Cement and asphalt liners can crack under temperature change and wet‐and‐dry conditions Synthetic liners are commonly used and usually consist of some type of plastic They require careful installation by an experienced contractor If the liner is properly installed and is not punctured seepage does not occur Synthetic liners are inert and therefore they are often used in lagoons that contain toxic wastes

The clogging of soil pores forms natural liners This occurs due to (i) settled solids (ii) microbial growth and (iii) chemical clogging of the soil due to ionic charges However natural liners tend to be unreliable because these natural modes for forming a natural liner or sealant are dependent on changing characteristics of the wastewater

Large and diverse populations of archaea algae (Fig 12) bacteria and protozoa (Fig 13) are found in lagoons Changes in numbers and dominant groups or species of organisms depend on biotic (biological) and abiotic (chemical and physical) factors (Tables 14 and 15) The most important abiotic factors are (i) composition and strength of the influent (ii) dissolved oxygen (iii) pH (iv) temperature and (v) sunlight

The organisms found in facultative lagoons are more diverse than those found in many other biological wastewater treatment processes including aerated and anaerobic lagoons The

Table 13 Disadvantages of lagoons as compared with more advanced wastewater treatment processes

Less efficient in cold climates than other processesRequire large amounts of landEffluent quality varies with seasonal changes in wastewater temperatureEffluent from facultative lagoons contains algae and may require additional treatment to meet discharge requirementsSeasonal turnover and release of benthic organismsSystem upsets usually result in odor productionIf not properly maintained lagoons can provide a breeding area for midges mosquitoes and other insects

6 IntroductIon

greater diversity of life is due to the highly complex growth conditions in lagoons where algae archaea bacteria crustaceans and rotifers are present in large numbers and perform significant roles Lagoons rely primarily on bacteria to degrade organic (carbonaceous biochemical oxygen demand cBOD) and nitrogenous (nitrogenous biochemical oxygen demand) wastes The biological degradation of wastes is similar to the natural purification of wastes in streams natural ponds and lakes These organisms are components of a food web (Fig 14) where carbon and energy are transferred from one organism to another The interactions between these organisms are complex and they contribute to changes in wastewater chemistry

There are three basic types of lagoons according to microbial activity that are used to degrade organic and nitrogenous wastes The types of lagoons are aerobic (aerated) facultative and anaerobic The biological differences between the lagoons consist of the

(a)

(b)

(c)

(d)

Figure 12 commonly occurring algae in facultative lagoons commonly occurring blue-green algae or cyanobacteria in facultative lagoons include (a) Phormidium (b) Aphanotheca (c) Planktothrix and (d) Aphanizomenon

IntroductIon 7

following (i) the dominant microbes present in the lagoon (Table 16) (ii) the dominant biological reactions that occur in the lagoon and (iii) the depth of the lagoon

Lagoons can be used alone or in combination with other wastewater treatment processes Lagoon systems can consist of a single lagoon or multiple lagoons and may include wastewater recirculation Multiple lagoons can be configured in series or parallel mode of operation (Fig 15)

Paramecium

Strongylidium

Bodo

Vaginicola

Euplotes

ArcellaEpistylis

Pleuromonas

Acineta

Amoeba

Difugia

Opercularia

Figure 13 commonly occurring protozoa in facultative lagoons commonly occurring protozoa in facultative lagoons include the amoebae Arcella Amoeba and Difflugia the flagellates Bodo and Pleuromonas the free-swimming ciliates Paramecium and Strongylidium the crawling ciliates Euplotes the stalk ciliates Epistylis and Opercularia and the suctorian Acineta

8 IntroductIon

Aerobic LAgoon

An aerobic (aerated) lagoon contains dissolved oxygen from surface to bottom and has an average detention time of 3ndash10 days The lagoon usually is 6ndash20 ft deep Oxygen is sup-plied through diffused or mechanical aeration A significant advantage of an aerated lagoon is the small land requirement

Table 14 biotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

Algal growthAvailable nichesBurrowing animalsCarbon dioxide productionCell lysisDenitrificationDominant microbesFood websMethane productionMixed acid productionMutualistic relationshipsNitrificationOxygen productionPhotosynthesisPlant growth (aquatic and terrestrial)Population densitiesPredatorndashprey relationshipsProduction of toxic products including ammonia and hydrogen sulfideSulfur oxidationSulfur reductionSyntrophic relationship

Table 15 Abiotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

AlkalinityEvaporationFlow (quantity and pattern)Ice coverLoadings (cBOD and nBOD)Nutrients (major and minor)pHPrecipitationSurface area for the adsorption of fungi and nitrifying bacteriaTemperatureRetention timeSunlightTotal dissolved solids (TDS)Toxic elements and compoundsVolume of sludge blanketWater currentsWind

cBOD carbonaceous biochemical oxygen demand nBOD nitrogenous biochemical oxygen demand

IntroductIon 9

Nematode

Protozoa Algae

Rotifers

Daphnia

Bacteria

Figure 14 Food web in a facultative lagoon Significant organisms in a facultative lagoon that perform direct or indirect roles in the stabilization of wastes are connected by a food web where each organism is a predator andor prey of another organism

Table 16 Dominant microbes in basic types of lagoons

Lagoon Dominate microbes

Aerobic Facultative anaerobic bacteriaAnaerobic Facultative anaerobic bacteria

MethanogensFacultative Algae

Facultative anaerobic bacteriaMethanogensPhotosynthetic bacteria

Inuent Efuent

Inuent Efuent

Figure 15 Series and parallel modes of operation of multiple lagoons In series mode of operation two or more lagoons are operated in ldquotrain-likerdquo fashion where the influent enters only one lagoon and discharges to the next lagoon In parallel mode of operation influent enters at least two lagoons

Copyright copy 2015 by John Wiley amp Sons Inc All rights reserved

Published by John Wiley amp Sons Inc Hoboken New JerseyPublished simultaneously in Canada

No part of this publication may be reproduced stored in a retrieval system or transmitted in any form or by any means electronic mechanical photocopying recording scanning or otherwise except as permitted under Section 107 or 108 of the 1976 United States Copyright Act without either the prior written permission of the Publisher or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center Inc 222 Rosewood Drive Danvers MA 01923 (978) 750-8400 fax (978) 750-4470 or on the web at wwwcopyrightcom Requests to the Publisher for permission should be addressed to the Permissions Department John Wiley amp Sons Inc 111 River Street Hoboken NJ 07030 (201) 748-6011 fax (201) 748-6008 or online at httpwwwwileycomgopermission

Limit of LiabilityDisclaimer of Warranty While the publisher and author have used their best efforts in preparing this book they make no representations or warranties with respect to the accuracy or completeness of the contents of this book and specifically disclaim any implied warranties of merchantability or fitness for a particular purpose No warranty may be created or extended by sales representatives or written sales materials The advice and strategies contained herein may not be suitable for your situation You should consult with a professional where appropriate Neither the publisher nor author shall be liable for any loss of profit or any other commercial damages including but not limited to special incidental consequential or other damages

For general information on our other products and services or for technical support please contact our Customer Care Department within the United States at (800) 762-2974 outside the United States at (317) 572-3993 or fax (317) 572-4002

Wiley also publishes its books in a variety of electronic formats Some content that appears in print may not be available in electronic formats For more information about Wiley products visit our web site at wwwwileycom

Library of Congress Cataloging-in-Publication Data is available

ISBN 978-0-470-05072-9

Printed in the United States of America

10 9 8 7 6 5 4 3 2 1

In loving memory of Pauline Testa Gerardi

vii

Preface xi

acknowledgments xiii

Part I oVerVIew 1

1 Introduction 3

2 Carbon and Energy Substrates 13

3 Microbial Interactions 19

4 The Facultative Lagoon 35

Part II lower lIfe forms 43

5 Bacteria 45

6 Archaea 59

7 Fungi 65

8 Bioaugmentation 69

9 Purple and Green Sulfur Bacteria 73

10 Pathogens and Disinfection 77

Contents

viii Contents

Part III algae 85

11 Green Algae and Diatoms 87

12 Blue‐Green Algae (Cyanobacteria) 97

13 Algae Alkalinity and pH 105

14 Control Measures for Undesired Algal Growth 111

Part IV HIgHer lIfe forms 121

15 Protozoa 123

16 Metazoa 135

Part V Plants 143

17 Cattails and Bulrushes 145

18 Duckweed and Watermeal 149

19 Weed Problems 153

Part VI large aQUatIc and terrestIal anImals 157

20 Insects 159

21 Fish 167

22 Animal Control 171

Part VII slUdge and odors 175

23 Sludge Accumulation and Disposal 177

24 Reed Beds 181

25 Odors 183

Part VIII monItorIng 189

26 Nitrification 191

27 BOD and TSS 195

Contents ix

28 Monitoring Parameters 199

29 Troubleshooting Notes 203

BIBlIograPHy 209

lIst of aBBreVIatIons 213

glossary 215

sUBJect IndeX 223

genera and sPecIes IndeX 227

xi

Facultative lagoons are commonly used for the treatment of domestic municipal and industrial wastewaters They often are more appropriate for use than conventional forms of secondary treatment in developing countries However as discharge requirements become more stringent a review of the biological chemical and physical interactions in facultative lagoons is critical for the successful operation and compliance with discharge requirements

This book provides operators laboratory technicians and engineers with a review of the critical roles of microscopic and macroscopic organisms that live in and around lagoons Proper design parameters for facultative lagoons have been addressed in numerous texts and other publications including those of federal and state regulatory agencies For that reason this text does not address and enumerate those parameters This book provides biological and chemical approaches to understanding facultative lagoons and includes presentations on algae archaea bacteria crustaceans duckweed aquatic and immature insects grasses rotifers watermeal weeds worms and burrowing ani-mals The text also presents descriptions of the natural processes of wastewater treatment with algae bacteria and other organisms and operational problems that can occur their identification prevention and control

Monitoring and troubleshooting lagoons for acceptable operational conditions process control measures and acceptable effluent quality is not always simple The biological and chemical processes involved in wastewater treatment are numerous and often complex This book is written for lagoon operators who may not have the opportunity or time to obtain the training that they need for reviewing these natural processes

A review of the biological chemical and natural physical treatment processes that occur in aerobic facultative and anaerobic zones of a facultative lagoon is presented Critical biochemical reactions described include aerobic and anaerobic respiration fermentation photosynthesis and changes in pH and alkalinity Control measures for the excessive growth of algae duckweed watermeal and rooted plants as well as control measures for midges and mosquitoes and odors are offered

Preface

xii Preface

Today there is increasing pressure to replace wastewater lagoons with conventional processes This pressure is due to the concern to whether or not facultative lagoons can keep pace with ever‐changing regulations However facultative lagoons can be upgraded and operated to produce an effluent that is comparable to conventional treatment processes This book presents the biological chemical and physical processes that affect wastewater treatment and their corresponding changes in lagoon microbial ecosystems An under-standing of these changes can provide an operator with problem‐solving leverage and improved effluent quality

The Biology and Troubleshooting of Wastewater Lagoons is the eighth book in the Wastewater Microbiology Series by John Wiley amp Sons The series is designed for waste-water personnel and it presents a microbiological review of the significant groups of organisms and their roles in wastewater treatment facilities

Michael H GerardiLinden Pennsylvania

xiii

The author extends his sincere appreciation to David V Daverio VMD Stephanie A Daverio VMD Peter J Sikora VMD technicians and staff at Williamsport West Veterinary Hospital for all that you have done for joLie

Acknowledgments

Part I

Overview

The Biology and Troubleshooting of Facultative Lagoons First Edition Michael H Gerardi copy 2015 John Wiley amp Sons Inc Published 2015 by John Wiley amp Sons Inc

3

1

Lagoons are one of the oldest wastewater treatment systems They consist of inground earthen basins where wastewater is received held for a period of time treated and then discharged (Fig 11) Depending on the composition strength and volume of wastewater to be treated and discharge requirements a predetermined ldquoholdrdquo or retention time for the wastewater is used Although lagoons are simple in design there are many complex biological chemical and physical processes that occur in lagoons There are several different terms for lagoons Many of these terms are used interchangeably These terms include pond oxidation pond polishing pond sewage pond stabilization pond maturation pond and cell Some terms refer to the role of the lagoon in a wastewater treatment process (Table 11)

Lagoons or natural impoundments were used in the United States in the 1920s to capture liquid wastes With increasing knowledge of the wastewater treatment ability of lagoons they were and are used to treat agricultural domestic industrial and municipal wastes and wastewaters

Lagoons became popular in the 1950s Today numerous lagoons and lagoon systems are used especially in rural areas for the treatment of domestic and municipal wastewaters Although performance varies from good to bad lagoons that are properly designed con-structed and operated can produce effluent that meets secondary treatment standards

Lagoons are one of the most popular simplest and least expensive technologies for treating wastewater Lagoons do require relatively large amounts of land For each million gallons per day (MGD) of wastewater approximately 30 acres of lagoon are required for 50 pounds biochemical oxygen demand (BOD) per acre per day Some ldquoonce‐throughrdquo lagoons are as large as 40 MGD

Introduction

4 IntroductIon

Lagoons use natural and energy‐efficient processes to provide low‐cost wastewater treatment and they offer an alternative to more advanced wastewater treatment processes Although lagoons offer many advantages such as reduced maintenance cost when com-pared with other wastewater treatment systems (Table 12) they also have disadvantages such as the requirement for large amounts of land (Table 13)

Lagoons are designed to satisfy a specific site and need The design is based on several factors including type of soil amount of land area required climate quantity and compo-sition of the wastewater to be treated and discharge requirements However lagoon effluent may require additional treatment or polishing to remove pathogens or nutrients

Inuent Aerobic zone

Facultative zone

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

AlgaeEfuent

Figure 11 Facultative lagoon A facultative lagoon has three active microbial zones where wastewater is treated the zones consist of aerobic facultative and anaerobic habitats

Table 11 Terminology for lagoons or ponds

Term Description

Maturation Improves effluent from activated sludge process or trickling filter to tertiary quality principally to reduce the number of pathogens and nutrients

Oxidation Wastewater is purified by sedimentation and aerobic and anaerobic treatmentPolishing Increases the environmental quality of effluent from previous treatmentPrimary Receives raw (unsettled) wastewater and has a sludge layer that is responsible

for methane productionSecondary Receives settled wastewater or effluent from an anaerobic lagoonStabilization An anaerobic facultative or maturation lagoon

Table 12 Advantages of lagoons as compared with more advanced wastewater treatment processes

Can handle intermittent use and shock loads better than other processesInexpensive to constructRelatively small quantity of equipment is neededReduced maintenance costsRelatively simple to operateEffective in removing pathogensEffluent often suitable for irrigation due to high nutrient contentFewer solid‐handling problems

IntroductIon 5

Most lagoons are found in small rural communities Here lagoons often cost less to construct operate and maintain than other wastewater treatment systems Although lagoons require more land than other wastewater treatment systems land is usually more available and affordable in rural areas Because lagoons treat a large variety of wastes they must be properly constructed to prevent soil and groundwater contamination

Wastewater lagoons must be sealed or lined to prevent seepage at the bottom and sidewall of the lagoon to prevent subsurface and groundwater contamination There are several types of liners that are used (i) clay cement and asphalt (ii) synthetic and rubber and (iii) natural Most liners typically perform well for 15 years However premature failure can occur and is usually due to (i) cleaning or dredging operations (ii) membrane puncture (iii) scour of cover material (iv) substandard liner material and (v) weed growth The most commonly used liners for industrial wastewater lagoons include (i) chlorosulfonated polyethylene or Hypalonreg (ii) polypropylene (rPP) (iii) polyvinyl chloride (iv) reinforced linermdashlow density and (v) XR‐5regXR3reg These liners are tolerant of ice buildup and exposure to harsh and prolonged sunlight

Clay liners shrink and swell according to wastewater temperature and wet‐and‐dry conditions However compacted clay liners are susceptible to erosion and vegetative growth in the dike These conditions damage the integrity and strength of the liner and dike

Installation of clay requires proper moisture content and compaction Cement and asphalt liners can crack under temperature change and wet‐and‐dry conditions Synthetic liners are commonly used and usually consist of some type of plastic They require careful installation by an experienced contractor If the liner is properly installed and is not punctured seepage does not occur Synthetic liners are inert and therefore they are often used in lagoons that contain toxic wastes

The clogging of soil pores forms natural liners This occurs due to (i) settled solids (ii) microbial growth and (iii) chemical clogging of the soil due to ionic charges However natural liners tend to be unreliable because these natural modes for forming a natural liner or sealant are dependent on changing characteristics of the wastewater

Large and diverse populations of archaea algae (Fig 12) bacteria and protozoa (Fig 13) are found in lagoons Changes in numbers and dominant groups or species of organisms depend on biotic (biological) and abiotic (chemical and physical) factors (Tables 14 and 15) The most important abiotic factors are (i) composition and strength of the influent (ii) dissolved oxygen (iii) pH (iv) temperature and (v) sunlight

The organisms found in facultative lagoons are more diverse than those found in many other biological wastewater treatment processes including aerated and anaerobic lagoons The

Table 13 Disadvantages of lagoons as compared with more advanced wastewater treatment processes

Less efficient in cold climates than other processesRequire large amounts of landEffluent quality varies with seasonal changes in wastewater temperatureEffluent from facultative lagoons contains algae and may require additional treatment to meet discharge requirementsSeasonal turnover and release of benthic organismsSystem upsets usually result in odor productionIf not properly maintained lagoons can provide a breeding area for midges mosquitoes and other insects

6 IntroductIon

greater diversity of life is due to the highly complex growth conditions in lagoons where algae archaea bacteria crustaceans and rotifers are present in large numbers and perform significant roles Lagoons rely primarily on bacteria to degrade organic (carbonaceous biochemical oxygen demand cBOD) and nitrogenous (nitrogenous biochemical oxygen demand) wastes The biological degradation of wastes is similar to the natural purification of wastes in streams natural ponds and lakes These organisms are components of a food web (Fig 14) where carbon and energy are transferred from one organism to another The interactions between these organisms are complex and they contribute to changes in wastewater chemistry

There are three basic types of lagoons according to microbial activity that are used to degrade organic and nitrogenous wastes The types of lagoons are aerobic (aerated) facultative and anaerobic The biological differences between the lagoons consist of the

(a)

(b)

(c)

(d)

Figure 12 commonly occurring algae in facultative lagoons commonly occurring blue-green algae or cyanobacteria in facultative lagoons include (a) Phormidium (b) Aphanotheca (c) Planktothrix and (d) Aphanizomenon

IntroductIon 7

following (i) the dominant microbes present in the lagoon (Table 16) (ii) the dominant biological reactions that occur in the lagoon and (iii) the depth of the lagoon

Lagoons can be used alone or in combination with other wastewater treatment processes Lagoon systems can consist of a single lagoon or multiple lagoons and may include wastewater recirculation Multiple lagoons can be configured in series or parallel mode of operation (Fig 15)

Paramecium

Strongylidium

Bodo

Vaginicola

Euplotes

ArcellaEpistylis

Pleuromonas

Acineta

Amoeba

Difugia

Opercularia

Figure 13 commonly occurring protozoa in facultative lagoons commonly occurring protozoa in facultative lagoons include the amoebae Arcella Amoeba and Difflugia the flagellates Bodo and Pleuromonas the free-swimming ciliates Paramecium and Strongylidium the crawling ciliates Euplotes the stalk ciliates Epistylis and Opercularia and the suctorian Acineta

8 IntroductIon

Aerobic LAgoon

An aerobic (aerated) lagoon contains dissolved oxygen from surface to bottom and has an average detention time of 3ndash10 days The lagoon usually is 6ndash20 ft deep Oxygen is sup-plied through diffused or mechanical aeration A significant advantage of an aerated lagoon is the small land requirement

Table 14 biotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

Algal growthAvailable nichesBurrowing animalsCarbon dioxide productionCell lysisDenitrificationDominant microbesFood websMethane productionMixed acid productionMutualistic relationshipsNitrificationOxygen productionPhotosynthesisPlant growth (aquatic and terrestrial)Population densitiesPredatorndashprey relationshipsProduction of toxic products including ammonia and hydrogen sulfideSulfur oxidationSulfur reductionSyntrophic relationship

Table 15 Abiotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

AlkalinityEvaporationFlow (quantity and pattern)Ice coverLoadings (cBOD and nBOD)Nutrients (major and minor)pHPrecipitationSurface area for the adsorption of fungi and nitrifying bacteriaTemperatureRetention timeSunlightTotal dissolved solids (TDS)Toxic elements and compoundsVolume of sludge blanketWater currentsWind

cBOD carbonaceous biochemical oxygen demand nBOD nitrogenous biochemical oxygen demand

IntroductIon 9

Nematode

Protozoa Algae

Rotifers

Daphnia

Bacteria

Figure 14 Food web in a facultative lagoon Significant organisms in a facultative lagoon that perform direct or indirect roles in the stabilization of wastes are connected by a food web where each organism is a predator andor prey of another organism

Table 16 Dominant microbes in basic types of lagoons

Lagoon Dominate microbes

Aerobic Facultative anaerobic bacteriaAnaerobic Facultative anaerobic bacteria

MethanogensFacultative Algae

Facultative anaerobic bacteriaMethanogensPhotosynthetic bacteria

Inuent Efuent

Inuent Efuent

Figure 15 Series and parallel modes of operation of multiple lagoons In series mode of operation two or more lagoons are operated in ldquotrain-likerdquo fashion where the influent enters only one lagoon and discharges to the next lagoon In parallel mode of operation influent enters at least two lagoons

In loving memory of Pauline Testa Gerardi

vii

Preface xi

acknowledgments xiii

Part I oVerVIew 1

1 Introduction 3

2 Carbon and Energy Substrates 13

3 Microbial Interactions 19

4 The Facultative Lagoon 35

Part II lower lIfe forms 43

5 Bacteria 45

6 Archaea 59

7 Fungi 65

8 Bioaugmentation 69

9 Purple and Green Sulfur Bacteria 73

10 Pathogens and Disinfection 77

Contents

viii Contents

Part III algae 85

11 Green Algae and Diatoms 87

12 Blue‐Green Algae (Cyanobacteria) 97

13 Algae Alkalinity and pH 105

14 Control Measures for Undesired Algal Growth 111

Part IV HIgHer lIfe forms 121

15 Protozoa 123

16 Metazoa 135

Part V Plants 143

17 Cattails and Bulrushes 145

18 Duckweed and Watermeal 149

19 Weed Problems 153

Part VI large aQUatIc and terrestIal anImals 157

20 Insects 159

21 Fish 167

22 Animal Control 171

Part VII slUdge and odors 175

23 Sludge Accumulation and Disposal 177

24 Reed Beds 181

25 Odors 183

Part VIII monItorIng 189

26 Nitrification 191

27 BOD and TSS 195

Contents ix

28 Monitoring Parameters 199

29 Troubleshooting Notes 203

BIBlIograPHy 209

lIst of aBBreVIatIons 213

glossary 215

sUBJect IndeX 223

genera and sPecIes IndeX 227

xi

Facultative lagoons are commonly used for the treatment of domestic municipal and industrial wastewaters They often are more appropriate for use than conventional forms of secondary treatment in developing countries However as discharge requirements become more stringent a review of the biological chemical and physical interactions in facultative lagoons is critical for the successful operation and compliance with discharge requirements

This book provides operators laboratory technicians and engineers with a review of the critical roles of microscopic and macroscopic organisms that live in and around lagoons Proper design parameters for facultative lagoons have been addressed in numerous texts and other publications including those of federal and state regulatory agencies For that reason this text does not address and enumerate those parameters This book provides biological and chemical approaches to understanding facultative lagoons and includes presentations on algae archaea bacteria crustaceans duckweed aquatic and immature insects grasses rotifers watermeal weeds worms and burrowing ani-mals The text also presents descriptions of the natural processes of wastewater treatment with algae bacteria and other organisms and operational problems that can occur their identification prevention and control

Monitoring and troubleshooting lagoons for acceptable operational conditions process control measures and acceptable effluent quality is not always simple The biological and chemical processes involved in wastewater treatment are numerous and often complex This book is written for lagoon operators who may not have the opportunity or time to obtain the training that they need for reviewing these natural processes

A review of the biological chemical and natural physical treatment processes that occur in aerobic facultative and anaerobic zones of a facultative lagoon is presented Critical biochemical reactions described include aerobic and anaerobic respiration fermentation photosynthesis and changes in pH and alkalinity Control measures for the excessive growth of algae duckweed watermeal and rooted plants as well as control measures for midges and mosquitoes and odors are offered

Preface

xii Preface

Today there is increasing pressure to replace wastewater lagoons with conventional processes This pressure is due to the concern to whether or not facultative lagoons can keep pace with ever‐changing regulations However facultative lagoons can be upgraded and operated to produce an effluent that is comparable to conventional treatment processes This book presents the biological chemical and physical processes that affect wastewater treatment and their corresponding changes in lagoon microbial ecosystems An under-standing of these changes can provide an operator with problem‐solving leverage and improved effluent quality

The Biology and Troubleshooting of Wastewater Lagoons is the eighth book in the Wastewater Microbiology Series by John Wiley amp Sons The series is designed for waste-water personnel and it presents a microbiological review of the significant groups of organisms and their roles in wastewater treatment facilities

Michael H GerardiLinden Pennsylvania

xiii

The author extends his sincere appreciation to David V Daverio VMD Stephanie A Daverio VMD Peter J Sikora VMD technicians and staff at Williamsport West Veterinary Hospital for all that you have done for joLie

Acknowledgments

Part I

Overview

The Biology and Troubleshooting of Facultative Lagoons First Edition Michael H Gerardi copy 2015 John Wiley amp Sons Inc Published 2015 by John Wiley amp Sons Inc

3

1

Lagoons are one of the oldest wastewater treatment systems They consist of inground earthen basins where wastewater is received held for a period of time treated and then discharged (Fig 11) Depending on the composition strength and volume of wastewater to be treated and discharge requirements a predetermined ldquoholdrdquo or retention time for the wastewater is used Although lagoons are simple in design there are many complex biological chemical and physical processes that occur in lagoons There are several different terms for lagoons Many of these terms are used interchangeably These terms include pond oxidation pond polishing pond sewage pond stabilization pond maturation pond and cell Some terms refer to the role of the lagoon in a wastewater treatment process (Table 11)

Lagoons or natural impoundments were used in the United States in the 1920s to capture liquid wastes With increasing knowledge of the wastewater treatment ability of lagoons they were and are used to treat agricultural domestic industrial and municipal wastes and wastewaters

Lagoons became popular in the 1950s Today numerous lagoons and lagoon systems are used especially in rural areas for the treatment of domestic and municipal wastewaters Although performance varies from good to bad lagoons that are properly designed con-structed and operated can produce effluent that meets secondary treatment standards

Lagoons are one of the most popular simplest and least expensive technologies for treating wastewater Lagoons do require relatively large amounts of land For each million gallons per day (MGD) of wastewater approximately 30 acres of lagoon are required for 50 pounds biochemical oxygen demand (BOD) per acre per day Some ldquoonce‐throughrdquo lagoons are as large as 40 MGD

Introduction

4 IntroductIon

Lagoons use natural and energy‐efficient processes to provide low‐cost wastewater treatment and they offer an alternative to more advanced wastewater treatment processes Although lagoons offer many advantages such as reduced maintenance cost when com-pared with other wastewater treatment systems (Table 12) they also have disadvantages such as the requirement for large amounts of land (Table 13)

Lagoons are designed to satisfy a specific site and need The design is based on several factors including type of soil amount of land area required climate quantity and compo-sition of the wastewater to be treated and discharge requirements However lagoon effluent may require additional treatment or polishing to remove pathogens or nutrients

Inuent Aerobic zone

Facultative zone

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

AlgaeEfuent

Figure 11 Facultative lagoon A facultative lagoon has three active microbial zones where wastewater is treated the zones consist of aerobic facultative and anaerobic habitats

Table 11 Terminology for lagoons or ponds

Term Description

Maturation Improves effluent from activated sludge process or trickling filter to tertiary quality principally to reduce the number of pathogens and nutrients

Oxidation Wastewater is purified by sedimentation and aerobic and anaerobic treatmentPolishing Increases the environmental quality of effluent from previous treatmentPrimary Receives raw (unsettled) wastewater and has a sludge layer that is responsible

for methane productionSecondary Receives settled wastewater or effluent from an anaerobic lagoonStabilization An anaerobic facultative or maturation lagoon

Table 12 Advantages of lagoons as compared with more advanced wastewater treatment processes

Can handle intermittent use and shock loads better than other processesInexpensive to constructRelatively small quantity of equipment is neededReduced maintenance costsRelatively simple to operateEffective in removing pathogensEffluent often suitable for irrigation due to high nutrient contentFewer solid‐handling problems

IntroductIon 5

Most lagoons are found in small rural communities Here lagoons often cost less to construct operate and maintain than other wastewater treatment systems Although lagoons require more land than other wastewater treatment systems land is usually more available and affordable in rural areas Because lagoons treat a large variety of wastes they must be properly constructed to prevent soil and groundwater contamination

Wastewater lagoons must be sealed or lined to prevent seepage at the bottom and sidewall of the lagoon to prevent subsurface and groundwater contamination There are several types of liners that are used (i) clay cement and asphalt (ii) synthetic and rubber and (iii) natural Most liners typically perform well for 15 years However premature failure can occur and is usually due to (i) cleaning or dredging operations (ii) membrane puncture (iii) scour of cover material (iv) substandard liner material and (v) weed growth The most commonly used liners for industrial wastewater lagoons include (i) chlorosulfonated polyethylene or Hypalonreg (ii) polypropylene (rPP) (iii) polyvinyl chloride (iv) reinforced linermdashlow density and (v) XR‐5regXR3reg These liners are tolerant of ice buildup and exposure to harsh and prolonged sunlight

Clay liners shrink and swell according to wastewater temperature and wet‐and‐dry conditions However compacted clay liners are susceptible to erosion and vegetative growth in the dike These conditions damage the integrity and strength of the liner and dike

Installation of clay requires proper moisture content and compaction Cement and asphalt liners can crack under temperature change and wet‐and‐dry conditions Synthetic liners are commonly used and usually consist of some type of plastic They require careful installation by an experienced contractor If the liner is properly installed and is not punctured seepage does not occur Synthetic liners are inert and therefore they are often used in lagoons that contain toxic wastes

The clogging of soil pores forms natural liners This occurs due to (i) settled solids (ii) microbial growth and (iii) chemical clogging of the soil due to ionic charges However natural liners tend to be unreliable because these natural modes for forming a natural liner or sealant are dependent on changing characteristics of the wastewater

Large and diverse populations of archaea algae (Fig 12) bacteria and protozoa (Fig 13) are found in lagoons Changes in numbers and dominant groups or species of organisms depend on biotic (biological) and abiotic (chemical and physical) factors (Tables 14 and 15) The most important abiotic factors are (i) composition and strength of the influent (ii) dissolved oxygen (iii) pH (iv) temperature and (v) sunlight

The organisms found in facultative lagoons are more diverse than those found in many other biological wastewater treatment processes including aerated and anaerobic lagoons The

Table 13 Disadvantages of lagoons as compared with more advanced wastewater treatment processes

Less efficient in cold climates than other processesRequire large amounts of landEffluent quality varies with seasonal changes in wastewater temperatureEffluent from facultative lagoons contains algae and may require additional treatment to meet discharge requirementsSeasonal turnover and release of benthic organismsSystem upsets usually result in odor productionIf not properly maintained lagoons can provide a breeding area for midges mosquitoes and other insects

6 IntroductIon

greater diversity of life is due to the highly complex growth conditions in lagoons where algae archaea bacteria crustaceans and rotifers are present in large numbers and perform significant roles Lagoons rely primarily on bacteria to degrade organic (carbonaceous biochemical oxygen demand cBOD) and nitrogenous (nitrogenous biochemical oxygen demand) wastes The biological degradation of wastes is similar to the natural purification of wastes in streams natural ponds and lakes These organisms are components of a food web (Fig 14) where carbon and energy are transferred from one organism to another The interactions between these organisms are complex and they contribute to changes in wastewater chemistry

There are three basic types of lagoons according to microbial activity that are used to degrade organic and nitrogenous wastes The types of lagoons are aerobic (aerated) facultative and anaerobic The biological differences between the lagoons consist of the

(a)

(b)

(c)

(d)

Figure 12 commonly occurring algae in facultative lagoons commonly occurring blue-green algae or cyanobacteria in facultative lagoons include (a) Phormidium (b) Aphanotheca (c) Planktothrix and (d) Aphanizomenon

IntroductIon 7

following (i) the dominant microbes present in the lagoon (Table 16) (ii) the dominant biological reactions that occur in the lagoon and (iii) the depth of the lagoon

Lagoons can be used alone or in combination with other wastewater treatment processes Lagoon systems can consist of a single lagoon or multiple lagoons and may include wastewater recirculation Multiple lagoons can be configured in series or parallel mode of operation (Fig 15)

Paramecium

Strongylidium

Bodo

Vaginicola

Euplotes

ArcellaEpistylis

Pleuromonas

Acineta

Amoeba

Difugia

Opercularia

Figure 13 commonly occurring protozoa in facultative lagoons commonly occurring protozoa in facultative lagoons include the amoebae Arcella Amoeba and Difflugia the flagellates Bodo and Pleuromonas the free-swimming ciliates Paramecium and Strongylidium the crawling ciliates Euplotes the stalk ciliates Epistylis and Opercularia and the suctorian Acineta

8 IntroductIon

Aerobic LAgoon

An aerobic (aerated) lagoon contains dissolved oxygen from surface to bottom and has an average detention time of 3ndash10 days The lagoon usually is 6ndash20 ft deep Oxygen is sup-plied through diffused or mechanical aeration A significant advantage of an aerated lagoon is the small land requirement

Table 14 biotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

Algal growthAvailable nichesBurrowing animalsCarbon dioxide productionCell lysisDenitrificationDominant microbesFood websMethane productionMixed acid productionMutualistic relationshipsNitrificationOxygen productionPhotosynthesisPlant growth (aquatic and terrestrial)Population densitiesPredatorndashprey relationshipsProduction of toxic products including ammonia and hydrogen sulfideSulfur oxidationSulfur reductionSyntrophic relationship

Table 15 Abiotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

AlkalinityEvaporationFlow (quantity and pattern)Ice coverLoadings (cBOD and nBOD)Nutrients (major and minor)pHPrecipitationSurface area for the adsorption of fungi and nitrifying bacteriaTemperatureRetention timeSunlightTotal dissolved solids (TDS)Toxic elements and compoundsVolume of sludge blanketWater currentsWind

cBOD carbonaceous biochemical oxygen demand nBOD nitrogenous biochemical oxygen demand

IntroductIon 9

Nematode

Protozoa Algae

Rotifers

Daphnia

Bacteria

Figure 14 Food web in a facultative lagoon Significant organisms in a facultative lagoon that perform direct or indirect roles in the stabilization of wastes are connected by a food web where each organism is a predator andor prey of another organism

Table 16 Dominant microbes in basic types of lagoons

Lagoon Dominate microbes

Aerobic Facultative anaerobic bacteriaAnaerobic Facultative anaerobic bacteria

MethanogensFacultative Algae

Facultative anaerobic bacteriaMethanogensPhotosynthetic bacteria

Inuent Efuent

Inuent Efuent

Figure 15 Series and parallel modes of operation of multiple lagoons In series mode of operation two or more lagoons are operated in ldquotrain-likerdquo fashion where the influent enters only one lagoon and discharges to the next lagoon In parallel mode of operation influent enters at least two lagoons

vii

Preface xi

acknowledgments xiii

Part I oVerVIew 1

1 Introduction 3

2 Carbon and Energy Substrates 13

3 Microbial Interactions 19

4 The Facultative Lagoon 35

Part II lower lIfe forms 43

5 Bacteria 45

6 Archaea 59

7 Fungi 65

8 Bioaugmentation 69

9 Purple and Green Sulfur Bacteria 73

10 Pathogens and Disinfection 77

Contents

viii Contents

Part III algae 85

11 Green Algae and Diatoms 87

12 Blue‐Green Algae (Cyanobacteria) 97

13 Algae Alkalinity and pH 105

14 Control Measures for Undesired Algal Growth 111

Part IV HIgHer lIfe forms 121

15 Protozoa 123

16 Metazoa 135

Part V Plants 143

17 Cattails and Bulrushes 145

18 Duckweed and Watermeal 149

19 Weed Problems 153

Part VI large aQUatIc and terrestIal anImals 157

20 Insects 159

21 Fish 167

22 Animal Control 171

Part VII slUdge and odors 175

23 Sludge Accumulation and Disposal 177

24 Reed Beds 181

25 Odors 183

Part VIII monItorIng 189

26 Nitrification 191

27 BOD and TSS 195

Contents ix

28 Monitoring Parameters 199

29 Troubleshooting Notes 203

BIBlIograPHy 209

lIst of aBBreVIatIons 213

glossary 215

sUBJect IndeX 223

genera and sPecIes IndeX 227

xi

Facultative lagoons are commonly used for the treatment of domestic municipal and industrial wastewaters They often are more appropriate for use than conventional forms of secondary treatment in developing countries However as discharge requirements become more stringent a review of the biological chemical and physical interactions in facultative lagoons is critical for the successful operation and compliance with discharge requirements

This book provides operators laboratory technicians and engineers with a review of the critical roles of microscopic and macroscopic organisms that live in and around lagoons Proper design parameters for facultative lagoons have been addressed in numerous texts and other publications including those of federal and state regulatory agencies For that reason this text does not address and enumerate those parameters This book provides biological and chemical approaches to understanding facultative lagoons and includes presentations on algae archaea bacteria crustaceans duckweed aquatic and immature insects grasses rotifers watermeal weeds worms and burrowing ani-mals The text also presents descriptions of the natural processes of wastewater treatment with algae bacteria and other organisms and operational problems that can occur their identification prevention and control

Monitoring and troubleshooting lagoons for acceptable operational conditions process control measures and acceptable effluent quality is not always simple The biological and chemical processes involved in wastewater treatment are numerous and often complex This book is written for lagoon operators who may not have the opportunity or time to obtain the training that they need for reviewing these natural processes

A review of the biological chemical and natural physical treatment processes that occur in aerobic facultative and anaerobic zones of a facultative lagoon is presented Critical biochemical reactions described include aerobic and anaerobic respiration fermentation photosynthesis and changes in pH and alkalinity Control measures for the excessive growth of algae duckweed watermeal and rooted plants as well as control measures for midges and mosquitoes and odors are offered

Preface

xii Preface

Today there is increasing pressure to replace wastewater lagoons with conventional processes This pressure is due to the concern to whether or not facultative lagoons can keep pace with ever‐changing regulations However facultative lagoons can be upgraded and operated to produce an effluent that is comparable to conventional treatment processes This book presents the biological chemical and physical processes that affect wastewater treatment and their corresponding changes in lagoon microbial ecosystems An under-standing of these changes can provide an operator with problem‐solving leverage and improved effluent quality

The Biology and Troubleshooting of Wastewater Lagoons is the eighth book in the Wastewater Microbiology Series by John Wiley amp Sons The series is designed for waste-water personnel and it presents a microbiological review of the significant groups of organisms and their roles in wastewater treatment facilities

Michael H GerardiLinden Pennsylvania

xiii

The author extends his sincere appreciation to David V Daverio VMD Stephanie A Daverio VMD Peter J Sikora VMD technicians and staff at Williamsport West Veterinary Hospital for all that you have done for joLie

Acknowledgments

Part I

Overview

The Biology and Troubleshooting of Facultative Lagoons First Edition Michael H Gerardi copy 2015 John Wiley amp Sons Inc Published 2015 by John Wiley amp Sons Inc

3

1

Lagoons are one of the oldest wastewater treatment systems They consist of inground earthen basins where wastewater is received held for a period of time treated and then discharged (Fig 11) Depending on the composition strength and volume of wastewater to be treated and discharge requirements a predetermined ldquoholdrdquo or retention time for the wastewater is used Although lagoons are simple in design there are many complex biological chemical and physical processes that occur in lagoons There are several different terms for lagoons Many of these terms are used interchangeably These terms include pond oxidation pond polishing pond sewage pond stabilization pond maturation pond and cell Some terms refer to the role of the lagoon in a wastewater treatment process (Table 11)

Lagoons or natural impoundments were used in the United States in the 1920s to capture liquid wastes With increasing knowledge of the wastewater treatment ability of lagoons they were and are used to treat agricultural domestic industrial and municipal wastes and wastewaters

Lagoons became popular in the 1950s Today numerous lagoons and lagoon systems are used especially in rural areas for the treatment of domestic and municipal wastewaters Although performance varies from good to bad lagoons that are properly designed con-structed and operated can produce effluent that meets secondary treatment standards

Lagoons are one of the most popular simplest and least expensive technologies for treating wastewater Lagoons do require relatively large amounts of land For each million gallons per day (MGD) of wastewater approximately 30 acres of lagoon are required for 50 pounds biochemical oxygen demand (BOD) per acre per day Some ldquoonce‐throughrdquo lagoons are as large as 40 MGD

Introduction

4 IntroductIon

Lagoons use natural and energy‐efficient processes to provide low‐cost wastewater treatment and they offer an alternative to more advanced wastewater treatment processes Although lagoons offer many advantages such as reduced maintenance cost when com-pared with other wastewater treatment systems (Table 12) they also have disadvantages such as the requirement for large amounts of land (Table 13)

Lagoons are designed to satisfy a specific site and need The design is based on several factors including type of soil amount of land area required climate quantity and compo-sition of the wastewater to be treated and discharge requirements However lagoon effluent may require additional treatment or polishing to remove pathogens or nutrients

Inuent Aerobic zone

Facultative zone

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

AlgaeEfuent

Figure 11 Facultative lagoon A facultative lagoon has three active microbial zones where wastewater is treated the zones consist of aerobic facultative and anaerobic habitats

Table 11 Terminology for lagoons or ponds

Term Description

Maturation Improves effluent from activated sludge process or trickling filter to tertiary quality principally to reduce the number of pathogens and nutrients

Oxidation Wastewater is purified by sedimentation and aerobic and anaerobic treatmentPolishing Increases the environmental quality of effluent from previous treatmentPrimary Receives raw (unsettled) wastewater and has a sludge layer that is responsible

for methane productionSecondary Receives settled wastewater or effluent from an anaerobic lagoonStabilization An anaerobic facultative or maturation lagoon

Table 12 Advantages of lagoons as compared with more advanced wastewater treatment processes

Can handle intermittent use and shock loads better than other processesInexpensive to constructRelatively small quantity of equipment is neededReduced maintenance costsRelatively simple to operateEffective in removing pathogensEffluent often suitable for irrigation due to high nutrient contentFewer solid‐handling problems

IntroductIon 5

Most lagoons are found in small rural communities Here lagoons often cost less to construct operate and maintain than other wastewater treatment systems Although lagoons require more land than other wastewater treatment systems land is usually more available and affordable in rural areas Because lagoons treat a large variety of wastes they must be properly constructed to prevent soil and groundwater contamination

Wastewater lagoons must be sealed or lined to prevent seepage at the bottom and sidewall of the lagoon to prevent subsurface and groundwater contamination There are several types of liners that are used (i) clay cement and asphalt (ii) synthetic and rubber and (iii) natural Most liners typically perform well for 15 years However premature failure can occur and is usually due to (i) cleaning or dredging operations (ii) membrane puncture (iii) scour of cover material (iv) substandard liner material and (v) weed growth The most commonly used liners for industrial wastewater lagoons include (i) chlorosulfonated polyethylene or Hypalonreg (ii) polypropylene (rPP) (iii) polyvinyl chloride (iv) reinforced linermdashlow density and (v) XR‐5regXR3reg These liners are tolerant of ice buildup and exposure to harsh and prolonged sunlight

Clay liners shrink and swell according to wastewater temperature and wet‐and‐dry conditions However compacted clay liners are susceptible to erosion and vegetative growth in the dike These conditions damage the integrity and strength of the liner and dike

Installation of clay requires proper moisture content and compaction Cement and asphalt liners can crack under temperature change and wet‐and‐dry conditions Synthetic liners are commonly used and usually consist of some type of plastic They require careful installation by an experienced contractor If the liner is properly installed and is not punctured seepage does not occur Synthetic liners are inert and therefore they are often used in lagoons that contain toxic wastes

The clogging of soil pores forms natural liners This occurs due to (i) settled solids (ii) microbial growth and (iii) chemical clogging of the soil due to ionic charges However natural liners tend to be unreliable because these natural modes for forming a natural liner or sealant are dependent on changing characteristics of the wastewater

Large and diverse populations of archaea algae (Fig 12) bacteria and protozoa (Fig 13) are found in lagoons Changes in numbers and dominant groups or species of organisms depend on biotic (biological) and abiotic (chemical and physical) factors (Tables 14 and 15) The most important abiotic factors are (i) composition and strength of the influent (ii) dissolved oxygen (iii) pH (iv) temperature and (v) sunlight

The organisms found in facultative lagoons are more diverse than those found in many other biological wastewater treatment processes including aerated and anaerobic lagoons The

Table 13 Disadvantages of lagoons as compared with more advanced wastewater treatment processes

Less efficient in cold climates than other processesRequire large amounts of landEffluent quality varies with seasonal changes in wastewater temperatureEffluent from facultative lagoons contains algae and may require additional treatment to meet discharge requirementsSeasonal turnover and release of benthic organismsSystem upsets usually result in odor productionIf not properly maintained lagoons can provide a breeding area for midges mosquitoes and other insects

6 IntroductIon

greater diversity of life is due to the highly complex growth conditions in lagoons where algae archaea bacteria crustaceans and rotifers are present in large numbers and perform significant roles Lagoons rely primarily on bacteria to degrade organic (carbonaceous biochemical oxygen demand cBOD) and nitrogenous (nitrogenous biochemical oxygen demand) wastes The biological degradation of wastes is similar to the natural purification of wastes in streams natural ponds and lakes These organisms are components of a food web (Fig 14) where carbon and energy are transferred from one organism to another The interactions between these organisms are complex and they contribute to changes in wastewater chemistry

There are three basic types of lagoons according to microbial activity that are used to degrade organic and nitrogenous wastes The types of lagoons are aerobic (aerated) facultative and anaerobic The biological differences between the lagoons consist of the

(a)

(b)

(c)

(d)

Figure 12 commonly occurring algae in facultative lagoons commonly occurring blue-green algae or cyanobacteria in facultative lagoons include (a) Phormidium (b) Aphanotheca (c) Planktothrix and (d) Aphanizomenon

IntroductIon 7

following (i) the dominant microbes present in the lagoon (Table 16) (ii) the dominant biological reactions that occur in the lagoon and (iii) the depth of the lagoon

Lagoons can be used alone or in combination with other wastewater treatment processes Lagoon systems can consist of a single lagoon or multiple lagoons and may include wastewater recirculation Multiple lagoons can be configured in series or parallel mode of operation (Fig 15)

Paramecium

Strongylidium

Bodo

Vaginicola

Euplotes

ArcellaEpistylis

Pleuromonas

Acineta

Amoeba

Difugia

Opercularia

Figure 13 commonly occurring protozoa in facultative lagoons commonly occurring protozoa in facultative lagoons include the amoebae Arcella Amoeba and Difflugia the flagellates Bodo and Pleuromonas the free-swimming ciliates Paramecium and Strongylidium the crawling ciliates Euplotes the stalk ciliates Epistylis and Opercularia and the suctorian Acineta

8 IntroductIon

Aerobic LAgoon

An aerobic (aerated) lagoon contains dissolved oxygen from surface to bottom and has an average detention time of 3ndash10 days The lagoon usually is 6ndash20 ft deep Oxygen is sup-plied through diffused or mechanical aeration A significant advantage of an aerated lagoon is the small land requirement

Table 14 biotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

Algal growthAvailable nichesBurrowing animalsCarbon dioxide productionCell lysisDenitrificationDominant microbesFood websMethane productionMixed acid productionMutualistic relationshipsNitrificationOxygen productionPhotosynthesisPlant growth (aquatic and terrestrial)Population densitiesPredatorndashprey relationshipsProduction of toxic products including ammonia and hydrogen sulfideSulfur oxidationSulfur reductionSyntrophic relationship

Table 15 Abiotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

AlkalinityEvaporationFlow (quantity and pattern)Ice coverLoadings (cBOD and nBOD)Nutrients (major and minor)pHPrecipitationSurface area for the adsorption of fungi and nitrifying bacteriaTemperatureRetention timeSunlightTotal dissolved solids (TDS)Toxic elements and compoundsVolume of sludge blanketWater currentsWind

cBOD carbonaceous biochemical oxygen demand nBOD nitrogenous biochemical oxygen demand

IntroductIon 9

Nematode

Protozoa Algae

Rotifers

Daphnia

Bacteria

Figure 14 Food web in a facultative lagoon Significant organisms in a facultative lagoon that perform direct or indirect roles in the stabilization of wastes are connected by a food web where each organism is a predator andor prey of another organism

Table 16 Dominant microbes in basic types of lagoons

Lagoon Dominate microbes

Aerobic Facultative anaerobic bacteriaAnaerobic Facultative anaerobic bacteria

MethanogensFacultative Algae

Facultative anaerobic bacteriaMethanogensPhotosynthetic bacteria

Inuent Efuent

Inuent Efuent

Figure 15 Series and parallel modes of operation of multiple lagoons In series mode of operation two or more lagoons are operated in ldquotrain-likerdquo fashion where the influent enters only one lagoon and discharges to the next lagoon In parallel mode of operation influent enters at least two lagoons

viii Contents

Part III algae 85

11 Green Algae and Diatoms 87

12 Blue‐Green Algae (Cyanobacteria) 97

13 Algae Alkalinity and pH 105

14 Control Measures for Undesired Algal Growth 111

Part IV HIgHer lIfe forms 121

15 Protozoa 123

16 Metazoa 135

Part V Plants 143

17 Cattails and Bulrushes 145

18 Duckweed and Watermeal 149

19 Weed Problems 153

Part VI large aQUatIc and terrestIal anImals 157

20 Insects 159

21 Fish 167

22 Animal Control 171

Part VII slUdge and odors 175

23 Sludge Accumulation and Disposal 177

24 Reed Beds 181

25 Odors 183

Part VIII monItorIng 189

26 Nitrification 191

27 BOD and TSS 195

Contents ix

28 Monitoring Parameters 199

29 Troubleshooting Notes 203

BIBlIograPHy 209

lIst of aBBreVIatIons 213

glossary 215

sUBJect IndeX 223

genera and sPecIes IndeX 227

xi

Facultative lagoons are commonly used for the treatment of domestic municipal and industrial wastewaters They often are more appropriate for use than conventional forms of secondary treatment in developing countries However as discharge requirements become more stringent a review of the biological chemical and physical interactions in facultative lagoons is critical for the successful operation and compliance with discharge requirements

This book provides operators laboratory technicians and engineers with a review of the critical roles of microscopic and macroscopic organisms that live in and around lagoons Proper design parameters for facultative lagoons have been addressed in numerous texts and other publications including those of federal and state regulatory agencies For that reason this text does not address and enumerate those parameters This book provides biological and chemical approaches to understanding facultative lagoons and includes presentations on algae archaea bacteria crustaceans duckweed aquatic and immature insects grasses rotifers watermeal weeds worms and burrowing ani-mals The text also presents descriptions of the natural processes of wastewater treatment with algae bacteria and other organisms and operational problems that can occur their identification prevention and control

Monitoring and troubleshooting lagoons for acceptable operational conditions process control measures and acceptable effluent quality is not always simple The biological and chemical processes involved in wastewater treatment are numerous and often complex This book is written for lagoon operators who may not have the opportunity or time to obtain the training that they need for reviewing these natural processes

A review of the biological chemical and natural physical treatment processes that occur in aerobic facultative and anaerobic zones of a facultative lagoon is presented Critical biochemical reactions described include aerobic and anaerobic respiration fermentation photosynthesis and changes in pH and alkalinity Control measures for the excessive growth of algae duckweed watermeal and rooted plants as well as control measures for midges and mosquitoes and odors are offered

Preface

xii Preface

Today there is increasing pressure to replace wastewater lagoons with conventional processes This pressure is due to the concern to whether or not facultative lagoons can keep pace with ever‐changing regulations However facultative lagoons can be upgraded and operated to produce an effluent that is comparable to conventional treatment processes This book presents the biological chemical and physical processes that affect wastewater treatment and their corresponding changes in lagoon microbial ecosystems An under-standing of these changes can provide an operator with problem‐solving leverage and improved effluent quality

The Biology and Troubleshooting of Wastewater Lagoons is the eighth book in the Wastewater Microbiology Series by John Wiley amp Sons The series is designed for waste-water personnel and it presents a microbiological review of the significant groups of organisms and their roles in wastewater treatment facilities

Michael H GerardiLinden Pennsylvania

xiii

The author extends his sincere appreciation to David V Daverio VMD Stephanie A Daverio VMD Peter J Sikora VMD technicians and staff at Williamsport West Veterinary Hospital for all that you have done for joLie

Acknowledgments

Part I

Overview

The Biology and Troubleshooting of Facultative Lagoons First Edition Michael H Gerardi copy 2015 John Wiley amp Sons Inc Published 2015 by John Wiley amp Sons Inc

3

1

Lagoons are one of the oldest wastewater treatment systems They consist of inground earthen basins where wastewater is received held for a period of time treated and then discharged (Fig 11) Depending on the composition strength and volume of wastewater to be treated and discharge requirements a predetermined ldquoholdrdquo or retention time for the wastewater is used Although lagoons are simple in design there are many complex biological chemical and physical processes that occur in lagoons There are several different terms for lagoons Many of these terms are used interchangeably These terms include pond oxidation pond polishing pond sewage pond stabilization pond maturation pond and cell Some terms refer to the role of the lagoon in a wastewater treatment process (Table 11)

Lagoons or natural impoundments were used in the United States in the 1920s to capture liquid wastes With increasing knowledge of the wastewater treatment ability of lagoons they were and are used to treat agricultural domestic industrial and municipal wastes and wastewaters

Lagoons became popular in the 1950s Today numerous lagoons and lagoon systems are used especially in rural areas for the treatment of domestic and municipal wastewaters Although performance varies from good to bad lagoons that are properly designed con-structed and operated can produce effluent that meets secondary treatment standards

Lagoons are one of the most popular simplest and least expensive technologies for treating wastewater Lagoons do require relatively large amounts of land For each million gallons per day (MGD) of wastewater approximately 30 acres of lagoon are required for 50 pounds biochemical oxygen demand (BOD) per acre per day Some ldquoonce‐throughrdquo lagoons are as large as 40 MGD

Introduction

4 IntroductIon

Lagoons use natural and energy‐efficient processes to provide low‐cost wastewater treatment and they offer an alternative to more advanced wastewater treatment processes Although lagoons offer many advantages such as reduced maintenance cost when com-pared with other wastewater treatment systems (Table 12) they also have disadvantages such as the requirement for large amounts of land (Table 13)

Lagoons are designed to satisfy a specific site and need The design is based on several factors including type of soil amount of land area required climate quantity and compo-sition of the wastewater to be treated and discharge requirements However lagoon effluent may require additional treatment or polishing to remove pathogens or nutrients

Inuent Aerobic zone

Facultative zone

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

AlgaeEfuent

Figure 11 Facultative lagoon A facultative lagoon has three active microbial zones where wastewater is treated the zones consist of aerobic facultative and anaerobic habitats

Table 11 Terminology for lagoons or ponds

Term Description

Maturation Improves effluent from activated sludge process or trickling filter to tertiary quality principally to reduce the number of pathogens and nutrients

Oxidation Wastewater is purified by sedimentation and aerobic and anaerobic treatmentPolishing Increases the environmental quality of effluent from previous treatmentPrimary Receives raw (unsettled) wastewater and has a sludge layer that is responsible

for methane productionSecondary Receives settled wastewater or effluent from an anaerobic lagoonStabilization An anaerobic facultative or maturation lagoon

Table 12 Advantages of lagoons as compared with more advanced wastewater treatment processes

Can handle intermittent use and shock loads better than other processesInexpensive to constructRelatively small quantity of equipment is neededReduced maintenance costsRelatively simple to operateEffective in removing pathogensEffluent often suitable for irrigation due to high nutrient contentFewer solid‐handling problems

IntroductIon 5

Most lagoons are found in small rural communities Here lagoons often cost less to construct operate and maintain than other wastewater treatment systems Although lagoons require more land than other wastewater treatment systems land is usually more available and affordable in rural areas Because lagoons treat a large variety of wastes they must be properly constructed to prevent soil and groundwater contamination

Wastewater lagoons must be sealed or lined to prevent seepage at the bottom and sidewall of the lagoon to prevent subsurface and groundwater contamination There are several types of liners that are used (i) clay cement and asphalt (ii) synthetic and rubber and (iii) natural Most liners typically perform well for 15 years However premature failure can occur and is usually due to (i) cleaning or dredging operations (ii) membrane puncture (iii) scour of cover material (iv) substandard liner material and (v) weed growth The most commonly used liners for industrial wastewater lagoons include (i) chlorosulfonated polyethylene or Hypalonreg (ii) polypropylene (rPP) (iii) polyvinyl chloride (iv) reinforced linermdashlow density and (v) XR‐5regXR3reg These liners are tolerant of ice buildup and exposure to harsh and prolonged sunlight

Clay liners shrink and swell according to wastewater temperature and wet‐and‐dry conditions However compacted clay liners are susceptible to erosion and vegetative growth in the dike These conditions damage the integrity and strength of the liner and dike

Installation of clay requires proper moisture content and compaction Cement and asphalt liners can crack under temperature change and wet‐and‐dry conditions Synthetic liners are commonly used and usually consist of some type of plastic They require careful installation by an experienced contractor If the liner is properly installed and is not punctured seepage does not occur Synthetic liners are inert and therefore they are often used in lagoons that contain toxic wastes

The clogging of soil pores forms natural liners This occurs due to (i) settled solids (ii) microbial growth and (iii) chemical clogging of the soil due to ionic charges However natural liners tend to be unreliable because these natural modes for forming a natural liner or sealant are dependent on changing characteristics of the wastewater

Large and diverse populations of archaea algae (Fig 12) bacteria and protozoa (Fig 13) are found in lagoons Changes in numbers and dominant groups or species of organisms depend on biotic (biological) and abiotic (chemical and physical) factors (Tables 14 and 15) The most important abiotic factors are (i) composition and strength of the influent (ii) dissolved oxygen (iii) pH (iv) temperature and (v) sunlight

The organisms found in facultative lagoons are more diverse than those found in many other biological wastewater treatment processes including aerated and anaerobic lagoons The

Table 13 Disadvantages of lagoons as compared with more advanced wastewater treatment processes

Less efficient in cold climates than other processesRequire large amounts of landEffluent quality varies with seasonal changes in wastewater temperatureEffluent from facultative lagoons contains algae and may require additional treatment to meet discharge requirementsSeasonal turnover and release of benthic organismsSystem upsets usually result in odor productionIf not properly maintained lagoons can provide a breeding area for midges mosquitoes and other insects

6 IntroductIon

greater diversity of life is due to the highly complex growth conditions in lagoons where algae archaea bacteria crustaceans and rotifers are present in large numbers and perform significant roles Lagoons rely primarily on bacteria to degrade organic (carbonaceous biochemical oxygen demand cBOD) and nitrogenous (nitrogenous biochemical oxygen demand) wastes The biological degradation of wastes is similar to the natural purification of wastes in streams natural ponds and lakes These organisms are components of a food web (Fig 14) where carbon and energy are transferred from one organism to another The interactions between these organisms are complex and they contribute to changes in wastewater chemistry

There are three basic types of lagoons according to microbial activity that are used to degrade organic and nitrogenous wastes The types of lagoons are aerobic (aerated) facultative and anaerobic The biological differences between the lagoons consist of the

(a)

(b)

(c)

(d)

Figure 12 commonly occurring algae in facultative lagoons commonly occurring blue-green algae or cyanobacteria in facultative lagoons include (a) Phormidium (b) Aphanotheca (c) Planktothrix and (d) Aphanizomenon

IntroductIon 7

following (i) the dominant microbes present in the lagoon (Table 16) (ii) the dominant biological reactions that occur in the lagoon and (iii) the depth of the lagoon

Lagoons can be used alone or in combination with other wastewater treatment processes Lagoon systems can consist of a single lagoon or multiple lagoons and may include wastewater recirculation Multiple lagoons can be configured in series or parallel mode of operation (Fig 15)

Paramecium

Strongylidium

Bodo

Vaginicola

Euplotes

ArcellaEpistylis

Pleuromonas

Acineta

Amoeba

Difugia

Opercularia

Figure 13 commonly occurring protozoa in facultative lagoons commonly occurring protozoa in facultative lagoons include the amoebae Arcella Amoeba and Difflugia the flagellates Bodo and Pleuromonas the free-swimming ciliates Paramecium and Strongylidium the crawling ciliates Euplotes the stalk ciliates Epistylis and Opercularia and the suctorian Acineta

8 IntroductIon

Aerobic LAgoon

An aerobic (aerated) lagoon contains dissolved oxygen from surface to bottom and has an average detention time of 3ndash10 days The lagoon usually is 6ndash20 ft deep Oxygen is sup-plied through diffused or mechanical aeration A significant advantage of an aerated lagoon is the small land requirement

Table 14 biotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

Algal growthAvailable nichesBurrowing animalsCarbon dioxide productionCell lysisDenitrificationDominant microbesFood websMethane productionMixed acid productionMutualistic relationshipsNitrificationOxygen productionPhotosynthesisPlant growth (aquatic and terrestrial)Population densitiesPredatorndashprey relationshipsProduction of toxic products including ammonia and hydrogen sulfideSulfur oxidationSulfur reductionSyntrophic relationship

Table 15 Abiotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

AlkalinityEvaporationFlow (quantity and pattern)Ice coverLoadings (cBOD and nBOD)Nutrients (major and minor)pHPrecipitationSurface area for the adsorption of fungi and nitrifying bacteriaTemperatureRetention timeSunlightTotal dissolved solids (TDS)Toxic elements and compoundsVolume of sludge blanketWater currentsWind

cBOD carbonaceous biochemical oxygen demand nBOD nitrogenous biochemical oxygen demand

IntroductIon 9

Nematode

Protozoa Algae

Rotifers

Daphnia

Bacteria

Figure 14 Food web in a facultative lagoon Significant organisms in a facultative lagoon that perform direct or indirect roles in the stabilization of wastes are connected by a food web where each organism is a predator andor prey of another organism

Table 16 Dominant microbes in basic types of lagoons

Lagoon Dominate microbes

Aerobic Facultative anaerobic bacteriaAnaerobic Facultative anaerobic bacteria

MethanogensFacultative Algae

Facultative anaerobic bacteriaMethanogensPhotosynthetic bacteria

Inuent Efuent

Inuent Efuent

Figure 15 Series and parallel modes of operation of multiple lagoons In series mode of operation two or more lagoons are operated in ldquotrain-likerdquo fashion where the influent enters only one lagoon and discharges to the next lagoon In parallel mode of operation influent enters at least two lagoons

Contents ix

28 Monitoring Parameters 199

29 Troubleshooting Notes 203

BIBlIograPHy 209

lIst of aBBreVIatIons 213

glossary 215

sUBJect IndeX 223

genera and sPecIes IndeX 227

xi

Facultative lagoons are commonly used for the treatment of domestic municipal and industrial wastewaters They often are more appropriate for use than conventional forms of secondary treatment in developing countries However as discharge requirements become more stringent a review of the biological chemical and physical interactions in facultative lagoons is critical for the successful operation and compliance with discharge requirements

This book provides operators laboratory technicians and engineers with a review of the critical roles of microscopic and macroscopic organisms that live in and around lagoons Proper design parameters for facultative lagoons have been addressed in numerous texts and other publications including those of federal and state regulatory agencies For that reason this text does not address and enumerate those parameters This book provides biological and chemical approaches to understanding facultative lagoons and includes presentations on algae archaea bacteria crustaceans duckweed aquatic and immature insects grasses rotifers watermeal weeds worms and burrowing ani-mals The text also presents descriptions of the natural processes of wastewater treatment with algae bacteria and other organisms and operational problems that can occur their identification prevention and control

Monitoring and troubleshooting lagoons for acceptable operational conditions process control measures and acceptable effluent quality is not always simple The biological and chemical processes involved in wastewater treatment are numerous and often complex This book is written for lagoon operators who may not have the opportunity or time to obtain the training that they need for reviewing these natural processes

A review of the biological chemical and natural physical treatment processes that occur in aerobic facultative and anaerobic zones of a facultative lagoon is presented Critical biochemical reactions described include aerobic and anaerobic respiration fermentation photosynthesis and changes in pH and alkalinity Control measures for the excessive growth of algae duckweed watermeal and rooted plants as well as control measures for midges and mosquitoes and odors are offered

Preface

xii Preface

Today there is increasing pressure to replace wastewater lagoons with conventional processes This pressure is due to the concern to whether or not facultative lagoons can keep pace with ever‐changing regulations However facultative lagoons can be upgraded and operated to produce an effluent that is comparable to conventional treatment processes This book presents the biological chemical and physical processes that affect wastewater treatment and their corresponding changes in lagoon microbial ecosystems An under-standing of these changes can provide an operator with problem‐solving leverage and improved effluent quality

The Biology and Troubleshooting of Wastewater Lagoons is the eighth book in the Wastewater Microbiology Series by John Wiley amp Sons The series is designed for waste-water personnel and it presents a microbiological review of the significant groups of organisms and their roles in wastewater treatment facilities

Michael H GerardiLinden Pennsylvania

xiii

The author extends his sincere appreciation to David V Daverio VMD Stephanie A Daverio VMD Peter J Sikora VMD technicians and staff at Williamsport West Veterinary Hospital for all that you have done for joLie

Acknowledgments

Part I

Overview

The Biology and Troubleshooting of Facultative Lagoons First Edition Michael H Gerardi copy 2015 John Wiley amp Sons Inc Published 2015 by John Wiley amp Sons Inc

3

1

Lagoons are one of the oldest wastewater treatment systems They consist of inground earthen basins where wastewater is received held for a period of time treated and then discharged (Fig 11) Depending on the composition strength and volume of wastewater to be treated and discharge requirements a predetermined ldquoholdrdquo or retention time for the wastewater is used Although lagoons are simple in design there are many complex biological chemical and physical processes that occur in lagoons There are several different terms for lagoons Many of these terms are used interchangeably These terms include pond oxidation pond polishing pond sewage pond stabilization pond maturation pond and cell Some terms refer to the role of the lagoon in a wastewater treatment process (Table 11)

Lagoons or natural impoundments were used in the United States in the 1920s to capture liquid wastes With increasing knowledge of the wastewater treatment ability of lagoons they were and are used to treat agricultural domestic industrial and municipal wastes and wastewaters

Lagoons became popular in the 1950s Today numerous lagoons and lagoon systems are used especially in rural areas for the treatment of domestic and municipal wastewaters Although performance varies from good to bad lagoons that are properly designed con-structed and operated can produce effluent that meets secondary treatment standards

Lagoons are one of the most popular simplest and least expensive technologies for treating wastewater Lagoons do require relatively large amounts of land For each million gallons per day (MGD) of wastewater approximately 30 acres of lagoon are required for 50 pounds biochemical oxygen demand (BOD) per acre per day Some ldquoonce‐throughrdquo lagoons are as large as 40 MGD

Introduction

4 IntroductIon

Lagoons use natural and energy‐efficient processes to provide low‐cost wastewater treatment and they offer an alternative to more advanced wastewater treatment processes Although lagoons offer many advantages such as reduced maintenance cost when com-pared with other wastewater treatment systems (Table 12) they also have disadvantages such as the requirement for large amounts of land (Table 13)

Lagoons are designed to satisfy a specific site and need The design is based on several factors including type of soil amount of land area required climate quantity and compo-sition of the wastewater to be treated and discharge requirements However lagoon effluent may require additional treatment or polishing to remove pathogens or nutrients

Inuent Aerobic zone

Facultative zone

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

AlgaeEfuent

Figure 11 Facultative lagoon A facultative lagoon has three active microbial zones where wastewater is treated the zones consist of aerobic facultative and anaerobic habitats

Table 11 Terminology for lagoons or ponds

Term Description

Maturation Improves effluent from activated sludge process or trickling filter to tertiary quality principally to reduce the number of pathogens and nutrients

Oxidation Wastewater is purified by sedimentation and aerobic and anaerobic treatmentPolishing Increases the environmental quality of effluent from previous treatmentPrimary Receives raw (unsettled) wastewater and has a sludge layer that is responsible

for methane productionSecondary Receives settled wastewater or effluent from an anaerobic lagoonStabilization An anaerobic facultative or maturation lagoon

Table 12 Advantages of lagoons as compared with more advanced wastewater treatment processes

Can handle intermittent use and shock loads better than other processesInexpensive to constructRelatively small quantity of equipment is neededReduced maintenance costsRelatively simple to operateEffective in removing pathogensEffluent often suitable for irrigation due to high nutrient contentFewer solid‐handling problems

IntroductIon 5

Most lagoons are found in small rural communities Here lagoons often cost less to construct operate and maintain than other wastewater treatment systems Although lagoons require more land than other wastewater treatment systems land is usually more available and affordable in rural areas Because lagoons treat a large variety of wastes they must be properly constructed to prevent soil and groundwater contamination

Wastewater lagoons must be sealed or lined to prevent seepage at the bottom and sidewall of the lagoon to prevent subsurface and groundwater contamination There are several types of liners that are used (i) clay cement and asphalt (ii) synthetic and rubber and (iii) natural Most liners typically perform well for 15 years However premature failure can occur and is usually due to (i) cleaning or dredging operations (ii) membrane puncture (iii) scour of cover material (iv) substandard liner material and (v) weed growth The most commonly used liners for industrial wastewater lagoons include (i) chlorosulfonated polyethylene or Hypalonreg (ii) polypropylene (rPP) (iii) polyvinyl chloride (iv) reinforced linermdashlow density and (v) XR‐5regXR3reg These liners are tolerant of ice buildup and exposure to harsh and prolonged sunlight

Clay liners shrink and swell according to wastewater temperature and wet‐and‐dry conditions However compacted clay liners are susceptible to erosion and vegetative growth in the dike These conditions damage the integrity and strength of the liner and dike

Installation of clay requires proper moisture content and compaction Cement and asphalt liners can crack under temperature change and wet‐and‐dry conditions Synthetic liners are commonly used and usually consist of some type of plastic They require careful installation by an experienced contractor If the liner is properly installed and is not punctured seepage does not occur Synthetic liners are inert and therefore they are often used in lagoons that contain toxic wastes

The clogging of soil pores forms natural liners This occurs due to (i) settled solids (ii) microbial growth and (iii) chemical clogging of the soil due to ionic charges However natural liners tend to be unreliable because these natural modes for forming a natural liner or sealant are dependent on changing characteristics of the wastewater

Large and diverse populations of archaea algae (Fig 12) bacteria and protozoa (Fig 13) are found in lagoons Changes in numbers and dominant groups or species of organisms depend on biotic (biological) and abiotic (chemical and physical) factors (Tables 14 and 15) The most important abiotic factors are (i) composition and strength of the influent (ii) dissolved oxygen (iii) pH (iv) temperature and (v) sunlight

The organisms found in facultative lagoons are more diverse than those found in many other biological wastewater treatment processes including aerated and anaerobic lagoons The

Table 13 Disadvantages of lagoons as compared with more advanced wastewater treatment processes

Less efficient in cold climates than other processesRequire large amounts of landEffluent quality varies with seasonal changes in wastewater temperatureEffluent from facultative lagoons contains algae and may require additional treatment to meet discharge requirementsSeasonal turnover and release of benthic organismsSystem upsets usually result in odor productionIf not properly maintained lagoons can provide a breeding area for midges mosquitoes and other insects

6 IntroductIon

greater diversity of life is due to the highly complex growth conditions in lagoons where algae archaea bacteria crustaceans and rotifers are present in large numbers and perform significant roles Lagoons rely primarily on bacteria to degrade organic (carbonaceous biochemical oxygen demand cBOD) and nitrogenous (nitrogenous biochemical oxygen demand) wastes The biological degradation of wastes is similar to the natural purification of wastes in streams natural ponds and lakes These organisms are components of a food web (Fig 14) where carbon and energy are transferred from one organism to another The interactions between these organisms are complex and they contribute to changes in wastewater chemistry

There are three basic types of lagoons according to microbial activity that are used to degrade organic and nitrogenous wastes The types of lagoons are aerobic (aerated) facultative and anaerobic The biological differences between the lagoons consist of the

(a)

(b)

(c)

(d)

Figure 12 commonly occurring algae in facultative lagoons commonly occurring blue-green algae or cyanobacteria in facultative lagoons include (a) Phormidium (b) Aphanotheca (c) Planktothrix and (d) Aphanizomenon

IntroductIon 7

following (i) the dominant microbes present in the lagoon (Table 16) (ii) the dominant biological reactions that occur in the lagoon and (iii) the depth of the lagoon

Lagoons can be used alone or in combination with other wastewater treatment processes Lagoon systems can consist of a single lagoon or multiple lagoons and may include wastewater recirculation Multiple lagoons can be configured in series or parallel mode of operation (Fig 15)

Paramecium

Strongylidium

Bodo

Vaginicola

Euplotes

ArcellaEpistylis

Pleuromonas

Acineta

Amoeba

Difugia

Opercularia

Figure 13 commonly occurring protozoa in facultative lagoons commonly occurring protozoa in facultative lagoons include the amoebae Arcella Amoeba and Difflugia the flagellates Bodo and Pleuromonas the free-swimming ciliates Paramecium and Strongylidium the crawling ciliates Euplotes the stalk ciliates Epistylis and Opercularia and the suctorian Acineta

8 IntroductIon

Aerobic LAgoon

An aerobic (aerated) lagoon contains dissolved oxygen from surface to bottom and has an average detention time of 3ndash10 days The lagoon usually is 6ndash20 ft deep Oxygen is sup-plied through diffused or mechanical aeration A significant advantage of an aerated lagoon is the small land requirement

Table 14 biotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

Algal growthAvailable nichesBurrowing animalsCarbon dioxide productionCell lysisDenitrificationDominant microbesFood websMethane productionMixed acid productionMutualistic relationshipsNitrificationOxygen productionPhotosynthesisPlant growth (aquatic and terrestrial)Population densitiesPredatorndashprey relationshipsProduction of toxic products including ammonia and hydrogen sulfideSulfur oxidationSulfur reductionSyntrophic relationship

Table 15 Abiotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

AlkalinityEvaporationFlow (quantity and pattern)Ice coverLoadings (cBOD and nBOD)Nutrients (major and minor)pHPrecipitationSurface area for the adsorption of fungi and nitrifying bacteriaTemperatureRetention timeSunlightTotal dissolved solids (TDS)Toxic elements and compoundsVolume of sludge blanketWater currentsWind

cBOD carbonaceous biochemical oxygen demand nBOD nitrogenous biochemical oxygen demand

IntroductIon 9

Nematode

Protozoa Algae

Rotifers

Daphnia

Bacteria

Figure 14 Food web in a facultative lagoon Significant organisms in a facultative lagoon that perform direct or indirect roles in the stabilization of wastes are connected by a food web where each organism is a predator andor prey of another organism

Table 16 Dominant microbes in basic types of lagoons

Lagoon Dominate microbes

Aerobic Facultative anaerobic bacteriaAnaerobic Facultative anaerobic bacteria

MethanogensFacultative Algae

Facultative anaerobic bacteriaMethanogensPhotosynthetic bacteria

Inuent Efuent

Inuent Efuent

Figure 15 Series and parallel modes of operation of multiple lagoons In series mode of operation two or more lagoons are operated in ldquotrain-likerdquo fashion where the influent enters only one lagoon and discharges to the next lagoon In parallel mode of operation influent enters at least two lagoons

xi

Facultative lagoons are commonly used for the treatment of domestic municipal and industrial wastewaters They often are more appropriate for use than conventional forms of secondary treatment in developing countries However as discharge requirements become more stringent a review of the biological chemical and physical interactions in facultative lagoons is critical for the successful operation and compliance with discharge requirements

This book provides operators laboratory technicians and engineers with a review of the critical roles of microscopic and macroscopic organisms that live in and around lagoons Proper design parameters for facultative lagoons have been addressed in numerous texts and other publications including those of federal and state regulatory agencies For that reason this text does not address and enumerate those parameters This book provides biological and chemical approaches to understanding facultative lagoons and includes presentations on algae archaea bacteria crustaceans duckweed aquatic and immature insects grasses rotifers watermeal weeds worms and burrowing ani-mals The text also presents descriptions of the natural processes of wastewater treatment with algae bacteria and other organisms and operational problems that can occur their identification prevention and control

Monitoring and troubleshooting lagoons for acceptable operational conditions process control measures and acceptable effluent quality is not always simple The biological and chemical processes involved in wastewater treatment are numerous and often complex This book is written for lagoon operators who may not have the opportunity or time to obtain the training that they need for reviewing these natural processes

A review of the biological chemical and natural physical treatment processes that occur in aerobic facultative and anaerobic zones of a facultative lagoon is presented Critical biochemical reactions described include aerobic and anaerobic respiration fermentation photosynthesis and changes in pH and alkalinity Control measures for the excessive growth of algae duckweed watermeal and rooted plants as well as control measures for midges and mosquitoes and odors are offered

Preface

xii Preface

Today there is increasing pressure to replace wastewater lagoons with conventional processes This pressure is due to the concern to whether or not facultative lagoons can keep pace with ever‐changing regulations However facultative lagoons can be upgraded and operated to produce an effluent that is comparable to conventional treatment processes This book presents the biological chemical and physical processes that affect wastewater treatment and their corresponding changes in lagoon microbial ecosystems An under-standing of these changes can provide an operator with problem‐solving leverage and improved effluent quality

The Biology and Troubleshooting of Wastewater Lagoons is the eighth book in the Wastewater Microbiology Series by John Wiley amp Sons The series is designed for waste-water personnel and it presents a microbiological review of the significant groups of organisms and their roles in wastewater treatment facilities

Michael H GerardiLinden Pennsylvania

xiii

The author extends his sincere appreciation to David V Daverio VMD Stephanie A Daverio VMD Peter J Sikora VMD technicians and staff at Williamsport West Veterinary Hospital for all that you have done for joLie

Acknowledgments

Part I

Overview

The Biology and Troubleshooting of Facultative Lagoons First Edition Michael H Gerardi copy 2015 John Wiley amp Sons Inc Published 2015 by John Wiley amp Sons Inc

3

1

Lagoons are one of the oldest wastewater treatment systems They consist of inground earthen basins where wastewater is received held for a period of time treated and then discharged (Fig 11) Depending on the composition strength and volume of wastewater to be treated and discharge requirements a predetermined ldquoholdrdquo or retention time for the wastewater is used Although lagoons are simple in design there are many complex biological chemical and physical processes that occur in lagoons There are several different terms for lagoons Many of these terms are used interchangeably These terms include pond oxidation pond polishing pond sewage pond stabilization pond maturation pond and cell Some terms refer to the role of the lagoon in a wastewater treatment process (Table 11)

Lagoons or natural impoundments were used in the United States in the 1920s to capture liquid wastes With increasing knowledge of the wastewater treatment ability of lagoons they were and are used to treat agricultural domestic industrial and municipal wastes and wastewaters

Lagoons became popular in the 1950s Today numerous lagoons and lagoon systems are used especially in rural areas for the treatment of domestic and municipal wastewaters Although performance varies from good to bad lagoons that are properly designed con-structed and operated can produce effluent that meets secondary treatment standards

Lagoons are one of the most popular simplest and least expensive technologies for treating wastewater Lagoons do require relatively large amounts of land For each million gallons per day (MGD) of wastewater approximately 30 acres of lagoon are required for 50 pounds biochemical oxygen demand (BOD) per acre per day Some ldquoonce‐throughrdquo lagoons are as large as 40 MGD

Introduction

4 IntroductIon

Lagoons use natural and energy‐efficient processes to provide low‐cost wastewater treatment and they offer an alternative to more advanced wastewater treatment processes Although lagoons offer many advantages such as reduced maintenance cost when com-pared with other wastewater treatment systems (Table 12) they also have disadvantages such as the requirement for large amounts of land (Table 13)

Lagoons are designed to satisfy a specific site and need The design is based on several factors including type of soil amount of land area required climate quantity and compo-sition of the wastewater to be treated and discharge requirements However lagoon effluent may require additional treatment or polishing to remove pathogens or nutrients

Inuent Aerobic zone

Facultative zone

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

AlgaeEfuent

Figure 11 Facultative lagoon A facultative lagoon has three active microbial zones where wastewater is treated the zones consist of aerobic facultative and anaerobic habitats

Table 11 Terminology for lagoons or ponds

Term Description

Maturation Improves effluent from activated sludge process or trickling filter to tertiary quality principally to reduce the number of pathogens and nutrients

Oxidation Wastewater is purified by sedimentation and aerobic and anaerobic treatmentPolishing Increases the environmental quality of effluent from previous treatmentPrimary Receives raw (unsettled) wastewater and has a sludge layer that is responsible

for methane productionSecondary Receives settled wastewater or effluent from an anaerobic lagoonStabilization An anaerobic facultative or maturation lagoon

Table 12 Advantages of lagoons as compared with more advanced wastewater treatment processes

Can handle intermittent use and shock loads better than other processesInexpensive to constructRelatively small quantity of equipment is neededReduced maintenance costsRelatively simple to operateEffective in removing pathogensEffluent often suitable for irrigation due to high nutrient contentFewer solid‐handling problems

IntroductIon 5

Most lagoons are found in small rural communities Here lagoons often cost less to construct operate and maintain than other wastewater treatment systems Although lagoons require more land than other wastewater treatment systems land is usually more available and affordable in rural areas Because lagoons treat a large variety of wastes they must be properly constructed to prevent soil and groundwater contamination

Wastewater lagoons must be sealed or lined to prevent seepage at the bottom and sidewall of the lagoon to prevent subsurface and groundwater contamination There are several types of liners that are used (i) clay cement and asphalt (ii) synthetic and rubber and (iii) natural Most liners typically perform well for 15 years However premature failure can occur and is usually due to (i) cleaning or dredging operations (ii) membrane puncture (iii) scour of cover material (iv) substandard liner material and (v) weed growth The most commonly used liners for industrial wastewater lagoons include (i) chlorosulfonated polyethylene or Hypalonreg (ii) polypropylene (rPP) (iii) polyvinyl chloride (iv) reinforced linermdashlow density and (v) XR‐5regXR3reg These liners are tolerant of ice buildup and exposure to harsh and prolonged sunlight

Clay liners shrink and swell according to wastewater temperature and wet‐and‐dry conditions However compacted clay liners are susceptible to erosion and vegetative growth in the dike These conditions damage the integrity and strength of the liner and dike

Installation of clay requires proper moisture content and compaction Cement and asphalt liners can crack under temperature change and wet‐and‐dry conditions Synthetic liners are commonly used and usually consist of some type of plastic They require careful installation by an experienced contractor If the liner is properly installed and is not punctured seepage does not occur Synthetic liners are inert and therefore they are often used in lagoons that contain toxic wastes

The clogging of soil pores forms natural liners This occurs due to (i) settled solids (ii) microbial growth and (iii) chemical clogging of the soil due to ionic charges However natural liners tend to be unreliable because these natural modes for forming a natural liner or sealant are dependent on changing characteristics of the wastewater

Large and diverse populations of archaea algae (Fig 12) bacteria and protozoa (Fig 13) are found in lagoons Changes in numbers and dominant groups or species of organisms depend on biotic (biological) and abiotic (chemical and physical) factors (Tables 14 and 15) The most important abiotic factors are (i) composition and strength of the influent (ii) dissolved oxygen (iii) pH (iv) temperature and (v) sunlight

The organisms found in facultative lagoons are more diverse than those found in many other biological wastewater treatment processes including aerated and anaerobic lagoons The

Table 13 Disadvantages of lagoons as compared with more advanced wastewater treatment processes

Less efficient in cold climates than other processesRequire large amounts of landEffluent quality varies with seasonal changes in wastewater temperatureEffluent from facultative lagoons contains algae and may require additional treatment to meet discharge requirementsSeasonal turnover and release of benthic organismsSystem upsets usually result in odor productionIf not properly maintained lagoons can provide a breeding area for midges mosquitoes and other insects

6 IntroductIon

greater diversity of life is due to the highly complex growth conditions in lagoons where algae archaea bacteria crustaceans and rotifers are present in large numbers and perform significant roles Lagoons rely primarily on bacteria to degrade organic (carbonaceous biochemical oxygen demand cBOD) and nitrogenous (nitrogenous biochemical oxygen demand) wastes The biological degradation of wastes is similar to the natural purification of wastes in streams natural ponds and lakes These organisms are components of a food web (Fig 14) where carbon and energy are transferred from one organism to another The interactions between these organisms are complex and they contribute to changes in wastewater chemistry

There are three basic types of lagoons according to microbial activity that are used to degrade organic and nitrogenous wastes The types of lagoons are aerobic (aerated) facultative and anaerobic The biological differences between the lagoons consist of the

(a)

(b)

(c)

(d)

Figure 12 commonly occurring algae in facultative lagoons commonly occurring blue-green algae or cyanobacteria in facultative lagoons include (a) Phormidium (b) Aphanotheca (c) Planktothrix and (d) Aphanizomenon

IntroductIon 7

following (i) the dominant microbes present in the lagoon (Table 16) (ii) the dominant biological reactions that occur in the lagoon and (iii) the depth of the lagoon

Lagoons can be used alone or in combination with other wastewater treatment processes Lagoon systems can consist of a single lagoon or multiple lagoons and may include wastewater recirculation Multiple lagoons can be configured in series or parallel mode of operation (Fig 15)

Paramecium

Strongylidium

Bodo

Vaginicola

Euplotes

ArcellaEpistylis

Pleuromonas

Acineta

Amoeba

Difugia

Opercularia

Figure 13 commonly occurring protozoa in facultative lagoons commonly occurring protozoa in facultative lagoons include the amoebae Arcella Amoeba and Difflugia the flagellates Bodo and Pleuromonas the free-swimming ciliates Paramecium and Strongylidium the crawling ciliates Euplotes the stalk ciliates Epistylis and Opercularia and the suctorian Acineta

8 IntroductIon

Aerobic LAgoon

An aerobic (aerated) lagoon contains dissolved oxygen from surface to bottom and has an average detention time of 3ndash10 days The lagoon usually is 6ndash20 ft deep Oxygen is sup-plied through diffused or mechanical aeration A significant advantage of an aerated lagoon is the small land requirement

Table 14 biotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

Algal growthAvailable nichesBurrowing animalsCarbon dioxide productionCell lysisDenitrificationDominant microbesFood websMethane productionMixed acid productionMutualistic relationshipsNitrificationOxygen productionPhotosynthesisPlant growth (aquatic and terrestrial)Population densitiesPredatorndashprey relationshipsProduction of toxic products including ammonia and hydrogen sulfideSulfur oxidationSulfur reductionSyntrophic relationship

Table 15 Abiotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

AlkalinityEvaporationFlow (quantity and pattern)Ice coverLoadings (cBOD and nBOD)Nutrients (major and minor)pHPrecipitationSurface area for the adsorption of fungi and nitrifying bacteriaTemperatureRetention timeSunlightTotal dissolved solids (TDS)Toxic elements and compoundsVolume of sludge blanketWater currentsWind

cBOD carbonaceous biochemical oxygen demand nBOD nitrogenous biochemical oxygen demand

IntroductIon 9

Nematode

Protozoa Algae

Rotifers

Daphnia

Bacteria

Figure 14 Food web in a facultative lagoon Significant organisms in a facultative lagoon that perform direct or indirect roles in the stabilization of wastes are connected by a food web where each organism is a predator andor prey of another organism

Table 16 Dominant microbes in basic types of lagoons

Lagoon Dominate microbes

Aerobic Facultative anaerobic bacteriaAnaerobic Facultative anaerobic bacteria

MethanogensFacultative Algae

Facultative anaerobic bacteriaMethanogensPhotosynthetic bacteria

Inuent Efuent

Inuent Efuent

Figure 15 Series and parallel modes of operation of multiple lagoons In series mode of operation two or more lagoons are operated in ldquotrain-likerdquo fashion where the influent enters only one lagoon and discharges to the next lagoon In parallel mode of operation influent enters at least two lagoons

xii Preface

Today there is increasing pressure to replace wastewater lagoons with conventional processes This pressure is due to the concern to whether or not facultative lagoons can keep pace with ever‐changing regulations However facultative lagoons can be upgraded and operated to produce an effluent that is comparable to conventional treatment processes This book presents the biological chemical and physical processes that affect wastewater treatment and their corresponding changes in lagoon microbial ecosystems An under-standing of these changes can provide an operator with problem‐solving leverage and improved effluent quality

The Biology and Troubleshooting of Wastewater Lagoons is the eighth book in the Wastewater Microbiology Series by John Wiley amp Sons The series is designed for waste-water personnel and it presents a microbiological review of the significant groups of organisms and their roles in wastewater treatment facilities

Michael H GerardiLinden Pennsylvania

xiii

The author extends his sincere appreciation to David V Daverio VMD Stephanie A Daverio VMD Peter J Sikora VMD technicians and staff at Williamsport West Veterinary Hospital for all that you have done for joLie

Acknowledgments

Part I

Overview

The Biology and Troubleshooting of Facultative Lagoons First Edition Michael H Gerardi copy 2015 John Wiley amp Sons Inc Published 2015 by John Wiley amp Sons Inc

3

1

Lagoons are one of the oldest wastewater treatment systems They consist of inground earthen basins where wastewater is received held for a period of time treated and then discharged (Fig 11) Depending on the composition strength and volume of wastewater to be treated and discharge requirements a predetermined ldquoholdrdquo or retention time for the wastewater is used Although lagoons are simple in design there are many complex biological chemical and physical processes that occur in lagoons There are several different terms for lagoons Many of these terms are used interchangeably These terms include pond oxidation pond polishing pond sewage pond stabilization pond maturation pond and cell Some terms refer to the role of the lagoon in a wastewater treatment process (Table 11)

Lagoons or natural impoundments were used in the United States in the 1920s to capture liquid wastes With increasing knowledge of the wastewater treatment ability of lagoons they were and are used to treat agricultural domestic industrial and municipal wastes and wastewaters

Lagoons became popular in the 1950s Today numerous lagoons and lagoon systems are used especially in rural areas for the treatment of domestic and municipal wastewaters Although performance varies from good to bad lagoons that are properly designed con-structed and operated can produce effluent that meets secondary treatment standards

Lagoons are one of the most popular simplest and least expensive technologies for treating wastewater Lagoons do require relatively large amounts of land For each million gallons per day (MGD) of wastewater approximately 30 acres of lagoon are required for 50 pounds biochemical oxygen demand (BOD) per acre per day Some ldquoonce‐throughrdquo lagoons are as large as 40 MGD

Introduction

4 IntroductIon

Lagoons use natural and energy‐efficient processes to provide low‐cost wastewater treatment and they offer an alternative to more advanced wastewater treatment processes Although lagoons offer many advantages such as reduced maintenance cost when com-pared with other wastewater treatment systems (Table 12) they also have disadvantages such as the requirement for large amounts of land (Table 13)

Lagoons are designed to satisfy a specific site and need The design is based on several factors including type of soil amount of land area required climate quantity and compo-sition of the wastewater to be treated and discharge requirements However lagoon effluent may require additional treatment or polishing to remove pathogens or nutrients

Inuent Aerobic zone

Facultative zone

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

AlgaeEfuent

Figure 11 Facultative lagoon A facultative lagoon has three active microbial zones where wastewater is treated the zones consist of aerobic facultative and anaerobic habitats

Table 11 Terminology for lagoons or ponds

Term Description

Maturation Improves effluent from activated sludge process or trickling filter to tertiary quality principally to reduce the number of pathogens and nutrients

Oxidation Wastewater is purified by sedimentation and aerobic and anaerobic treatmentPolishing Increases the environmental quality of effluent from previous treatmentPrimary Receives raw (unsettled) wastewater and has a sludge layer that is responsible

for methane productionSecondary Receives settled wastewater or effluent from an anaerobic lagoonStabilization An anaerobic facultative or maturation lagoon

Table 12 Advantages of lagoons as compared with more advanced wastewater treatment processes

Can handle intermittent use and shock loads better than other processesInexpensive to constructRelatively small quantity of equipment is neededReduced maintenance costsRelatively simple to operateEffective in removing pathogensEffluent often suitable for irrigation due to high nutrient contentFewer solid‐handling problems

IntroductIon 5

Most lagoons are found in small rural communities Here lagoons often cost less to construct operate and maintain than other wastewater treatment systems Although lagoons require more land than other wastewater treatment systems land is usually more available and affordable in rural areas Because lagoons treat a large variety of wastes they must be properly constructed to prevent soil and groundwater contamination

Wastewater lagoons must be sealed or lined to prevent seepage at the bottom and sidewall of the lagoon to prevent subsurface and groundwater contamination There are several types of liners that are used (i) clay cement and asphalt (ii) synthetic and rubber and (iii) natural Most liners typically perform well for 15 years However premature failure can occur and is usually due to (i) cleaning or dredging operations (ii) membrane puncture (iii) scour of cover material (iv) substandard liner material and (v) weed growth The most commonly used liners for industrial wastewater lagoons include (i) chlorosulfonated polyethylene or Hypalonreg (ii) polypropylene (rPP) (iii) polyvinyl chloride (iv) reinforced linermdashlow density and (v) XR‐5regXR3reg These liners are tolerant of ice buildup and exposure to harsh and prolonged sunlight

Clay liners shrink and swell according to wastewater temperature and wet‐and‐dry conditions However compacted clay liners are susceptible to erosion and vegetative growth in the dike These conditions damage the integrity and strength of the liner and dike

Installation of clay requires proper moisture content and compaction Cement and asphalt liners can crack under temperature change and wet‐and‐dry conditions Synthetic liners are commonly used and usually consist of some type of plastic They require careful installation by an experienced contractor If the liner is properly installed and is not punctured seepage does not occur Synthetic liners are inert and therefore they are often used in lagoons that contain toxic wastes

The clogging of soil pores forms natural liners This occurs due to (i) settled solids (ii) microbial growth and (iii) chemical clogging of the soil due to ionic charges However natural liners tend to be unreliable because these natural modes for forming a natural liner or sealant are dependent on changing characteristics of the wastewater

Large and diverse populations of archaea algae (Fig 12) bacteria and protozoa (Fig 13) are found in lagoons Changes in numbers and dominant groups or species of organisms depend on biotic (biological) and abiotic (chemical and physical) factors (Tables 14 and 15) The most important abiotic factors are (i) composition and strength of the influent (ii) dissolved oxygen (iii) pH (iv) temperature and (v) sunlight

The organisms found in facultative lagoons are more diverse than those found in many other biological wastewater treatment processes including aerated and anaerobic lagoons The

Table 13 Disadvantages of lagoons as compared with more advanced wastewater treatment processes

Less efficient in cold climates than other processesRequire large amounts of landEffluent quality varies with seasonal changes in wastewater temperatureEffluent from facultative lagoons contains algae and may require additional treatment to meet discharge requirementsSeasonal turnover and release of benthic organismsSystem upsets usually result in odor productionIf not properly maintained lagoons can provide a breeding area for midges mosquitoes and other insects

6 IntroductIon

greater diversity of life is due to the highly complex growth conditions in lagoons where algae archaea bacteria crustaceans and rotifers are present in large numbers and perform significant roles Lagoons rely primarily on bacteria to degrade organic (carbonaceous biochemical oxygen demand cBOD) and nitrogenous (nitrogenous biochemical oxygen demand) wastes The biological degradation of wastes is similar to the natural purification of wastes in streams natural ponds and lakes These organisms are components of a food web (Fig 14) where carbon and energy are transferred from one organism to another The interactions between these organisms are complex and they contribute to changes in wastewater chemistry

There are three basic types of lagoons according to microbial activity that are used to degrade organic and nitrogenous wastes The types of lagoons are aerobic (aerated) facultative and anaerobic The biological differences between the lagoons consist of the

(a)

(b)

(c)

(d)

Figure 12 commonly occurring algae in facultative lagoons commonly occurring blue-green algae or cyanobacteria in facultative lagoons include (a) Phormidium (b) Aphanotheca (c) Planktothrix and (d) Aphanizomenon

IntroductIon 7

following (i) the dominant microbes present in the lagoon (Table 16) (ii) the dominant biological reactions that occur in the lagoon and (iii) the depth of the lagoon

Lagoons can be used alone or in combination with other wastewater treatment processes Lagoon systems can consist of a single lagoon or multiple lagoons and may include wastewater recirculation Multiple lagoons can be configured in series or parallel mode of operation (Fig 15)

Paramecium

Strongylidium

Bodo

Vaginicola

Euplotes

ArcellaEpistylis

Pleuromonas

Acineta

Amoeba

Difugia

Opercularia

Figure 13 commonly occurring protozoa in facultative lagoons commonly occurring protozoa in facultative lagoons include the amoebae Arcella Amoeba and Difflugia the flagellates Bodo and Pleuromonas the free-swimming ciliates Paramecium and Strongylidium the crawling ciliates Euplotes the stalk ciliates Epistylis and Opercularia and the suctorian Acineta

8 IntroductIon

Aerobic LAgoon

An aerobic (aerated) lagoon contains dissolved oxygen from surface to bottom and has an average detention time of 3ndash10 days The lagoon usually is 6ndash20 ft deep Oxygen is sup-plied through diffused or mechanical aeration A significant advantage of an aerated lagoon is the small land requirement

Table 14 biotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

Algal growthAvailable nichesBurrowing animalsCarbon dioxide productionCell lysisDenitrificationDominant microbesFood websMethane productionMixed acid productionMutualistic relationshipsNitrificationOxygen productionPhotosynthesisPlant growth (aquatic and terrestrial)Population densitiesPredatorndashprey relationshipsProduction of toxic products including ammonia and hydrogen sulfideSulfur oxidationSulfur reductionSyntrophic relationship

Table 15 Abiotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

AlkalinityEvaporationFlow (quantity and pattern)Ice coverLoadings (cBOD and nBOD)Nutrients (major and minor)pHPrecipitationSurface area for the adsorption of fungi and nitrifying bacteriaTemperatureRetention timeSunlightTotal dissolved solids (TDS)Toxic elements and compoundsVolume of sludge blanketWater currentsWind

cBOD carbonaceous biochemical oxygen demand nBOD nitrogenous biochemical oxygen demand

IntroductIon 9

Nematode

Protozoa Algae

Rotifers

Daphnia

Bacteria

Figure 14 Food web in a facultative lagoon Significant organisms in a facultative lagoon that perform direct or indirect roles in the stabilization of wastes are connected by a food web where each organism is a predator andor prey of another organism

Table 16 Dominant microbes in basic types of lagoons

Lagoon Dominate microbes

Aerobic Facultative anaerobic bacteriaAnaerobic Facultative anaerobic bacteria

MethanogensFacultative Algae

Facultative anaerobic bacteriaMethanogensPhotosynthetic bacteria

Inuent Efuent

Inuent Efuent

Figure 15 Series and parallel modes of operation of multiple lagoons In series mode of operation two or more lagoons are operated in ldquotrain-likerdquo fashion where the influent enters only one lagoon and discharges to the next lagoon In parallel mode of operation influent enters at least two lagoons

xiii

The author extends his sincere appreciation to David V Daverio VMD Stephanie A Daverio VMD Peter J Sikora VMD technicians and staff at Williamsport West Veterinary Hospital for all that you have done for joLie

Acknowledgments

Part I

Overview

The Biology and Troubleshooting of Facultative Lagoons First Edition Michael H Gerardi copy 2015 John Wiley amp Sons Inc Published 2015 by John Wiley amp Sons Inc

3

1

Lagoons are one of the oldest wastewater treatment systems They consist of inground earthen basins where wastewater is received held for a period of time treated and then discharged (Fig 11) Depending on the composition strength and volume of wastewater to be treated and discharge requirements a predetermined ldquoholdrdquo or retention time for the wastewater is used Although lagoons are simple in design there are many complex biological chemical and physical processes that occur in lagoons There are several different terms for lagoons Many of these terms are used interchangeably These terms include pond oxidation pond polishing pond sewage pond stabilization pond maturation pond and cell Some terms refer to the role of the lagoon in a wastewater treatment process (Table 11)

Lagoons or natural impoundments were used in the United States in the 1920s to capture liquid wastes With increasing knowledge of the wastewater treatment ability of lagoons they were and are used to treat agricultural domestic industrial and municipal wastes and wastewaters

Lagoons became popular in the 1950s Today numerous lagoons and lagoon systems are used especially in rural areas for the treatment of domestic and municipal wastewaters Although performance varies from good to bad lagoons that are properly designed con-structed and operated can produce effluent that meets secondary treatment standards

Lagoons are one of the most popular simplest and least expensive technologies for treating wastewater Lagoons do require relatively large amounts of land For each million gallons per day (MGD) of wastewater approximately 30 acres of lagoon are required for 50 pounds biochemical oxygen demand (BOD) per acre per day Some ldquoonce‐throughrdquo lagoons are as large as 40 MGD

Introduction

4 IntroductIon

Lagoons use natural and energy‐efficient processes to provide low‐cost wastewater treatment and they offer an alternative to more advanced wastewater treatment processes Although lagoons offer many advantages such as reduced maintenance cost when com-pared with other wastewater treatment systems (Table 12) they also have disadvantages such as the requirement for large amounts of land (Table 13)

Lagoons are designed to satisfy a specific site and need The design is based on several factors including type of soil amount of land area required climate quantity and compo-sition of the wastewater to be treated and discharge requirements However lagoon effluent may require additional treatment or polishing to remove pathogens or nutrients

Inuent Aerobic zone

Facultative zone

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

AlgaeEfuent

Figure 11 Facultative lagoon A facultative lagoon has three active microbial zones where wastewater is treated the zones consist of aerobic facultative and anaerobic habitats

Table 11 Terminology for lagoons or ponds

Term Description

Maturation Improves effluent from activated sludge process or trickling filter to tertiary quality principally to reduce the number of pathogens and nutrients

Oxidation Wastewater is purified by sedimentation and aerobic and anaerobic treatmentPolishing Increases the environmental quality of effluent from previous treatmentPrimary Receives raw (unsettled) wastewater and has a sludge layer that is responsible

for methane productionSecondary Receives settled wastewater or effluent from an anaerobic lagoonStabilization An anaerobic facultative or maturation lagoon

Table 12 Advantages of lagoons as compared with more advanced wastewater treatment processes

Can handle intermittent use and shock loads better than other processesInexpensive to constructRelatively small quantity of equipment is neededReduced maintenance costsRelatively simple to operateEffective in removing pathogensEffluent often suitable for irrigation due to high nutrient contentFewer solid‐handling problems

IntroductIon 5

Most lagoons are found in small rural communities Here lagoons often cost less to construct operate and maintain than other wastewater treatment systems Although lagoons require more land than other wastewater treatment systems land is usually more available and affordable in rural areas Because lagoons treat a large variety of wastes they must be properly constructed to prevent soil and groundwater contamination

Wastewater lagoons must be sealed or lined to prevent seepage at the bottom and sidewall of the lagoon to prevent subsurface and groundwater contamination There are several types of liners that are used (i) clay cement and asphalt (ii) synthetic and rubber and (iii) natural Most liners typically perform well for 15 years However premature failure can occur and is usually due to (i) cleaning or dredging operations (ii) membrane puncture (iii) scour of cover material (iv) substandard liner material and (v) weed growth The most commonly used liners for industrial wastewater lagoons include (i) chlorosulfonated polyethylene or Hypalonreg (ii) polypropylene (rPP) (iii) polyvinyl chloride (iv) reinforced linermdashlow density and (v) XR‐5regXR3reg These liners are tolerant of ice buildup and exposure to harsh and prolonged sunlight

Clay liners shrink and swell according to wastewater temperature and wet‐and‐dry conditions However compacted clay liners are susceptible to erosion and vegetative growth in the dike These conditions damage the integrity and strength of the liner and dike

Installation of clay requires proper moisture content and compaction Cement and asphalt liners can crack under temperature change and wet‐and‐dry conditions Synthetic liners are commonly used and usually consist of some type of plastic They require careful installation by an experienced contractor If the liner is properly installed and is not punctured seepage does not occur Synthetic liners are inert and therefore they are often used in lagoons that contain toxic wastes

The clogging of soil pores forms natural liners This occurs due to (i) settled solids (ii) microbial growth and (iii) chemical clogging of the soil due to ionic charges However natural liners tend to be unreliable because these natural modes for forming a natural liner or sealant are dependent on changing characteristics of the wastewater

Large and diverse populations of archaea algae (Fig 12) bacteria and protozoa (Fig 13) are found in lagoons Changes in numbers and dominant groups or species of organisms depend on biotic (biological) and abiotic (chemical and physical) factors (Tables 14 and 15) The most important abiotic factors are (i) composition and strength of the influent (ii) dissolved oxygen (iii) pH (iv) temperature and (v) sunlight

The organisms found in facultative lagoons are more diverse than those found in many other biological wastewater treatment processes including aerated and anaerobic lagoons The

Table 13 Disadvantages of lagoons as compared with more advanced wastewater treatment processes

Less efficient in cold climates than other processesRequire large amounts of landEffluent quality varies with seasonal changes in wastewater temperatureEffluent from facultative lagoons contains algae and may require additional treatment to meet discharge requirementsSeasonal turnover and release of benthic organismsSystem upsets usually result in odor productionIf not properly maintained lagoons can provide a breeding area for midges mosquitoes and other insects

6 IntroductIon

greater diversity of life is due to the highly complex growth conditions in lagoons where algae archaea bacteria crustaceans and rotifers are present in large numbers and perform significant roles Lagoons rely primarily on bacteria to degrade organic (carbonaceous biochemical oxygen demand cBOD) and nitrogenous (nitrogenous biochemical oxygen demand) wastes The biological degradation of wastes is similar to the natural purification of wastes in streams natural ponds and lakes These organisms are components of a food web (Fig 14) where carbon and energy are transferred from one organism to another The interactions between these organisms are complex and they contribute to changes in wastewater chemistry

There are three basic types of lagoons according to microbial activity that are used to degrade organic and nitrogenous wastes The types of lagoons are aerobic (aerated) facultative and anaerobic The biological differences between the lagoons consist of the

(a)

(b)

(c)

(d)

Figure 12 commonly occurring algae in facultative lagoons commonly occurring blue-green algae or cyanobacteria in facultative lagoons include (a) Phormidium (b) Aphanotheca (c) Planktothrix and (d) Aphanizomenon

IntroductIon 7

following (i) the dominant microbes present in the lagoon (Table 16) (ii) the dominant biological reactions that occur in the lagoon and (iii) the depth of the lagoon

Lagoons can be used alone or in combination with other wastewater treatment processes Lagoon systems can consist of a single lagoon or multiple lagoons and may include wastewater recirculation Multiple lagoons can be configured in series or parallel mode of operation (Fig 15)

Paramecium

Strongylidium

Bodo

Vaginicola

Euplotes

ArcellaEpistylis

Pleuromonas

Acineta

Amoeba

Difugia

Opercularia

Figure 13 commonly occurring protozoa in facultative lagoons commonly occurring protozoa in facultative lagoons include the amoebae Arcella Amoeba and Difflugia the flagellates Bodo and Pleuromonas the free-swimming ciliates Paramecium and Strongylidium the crawling ciliates Euplotes the stalk ciliates Epistylis and Opercularia and the suctorian Acineta

8 IntroductIon

Aerobic LAgoon

An aerobic (aerated) lagoon contains dissolved oxygen from surface to bottom and has an average detention time of 3ndash10 days The lagoon usually is 6ndash20 ft deep Oxygen is sup-plied through diffused or mechanical aeration A significant advantage of an aerated lagoon is the small land requirement

Table 14 biotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

Algal growthAvailable nichesBurrowing animalsCarbon dioxide productionCell lysisDenitrificationDominant microbesFood websMethane productionMixed acid productionMutualistic relationshipsNitrificationOxygen productionPhotosynthesisPlant growth (aquatic and terrestrial)Population densitiesPredatorndashprey relationshipsProduction of toxic products including ammonia and hydrogen sulfideSulfur oxidationSulfur reductionSyntrophic relationship

Table 15 Abiotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

AlkalinityEvaporationFlow (quantity and pattern)Ice coverLoadings (cBOD and nBOD)Nutrients (major and minor)pHPrecipitationSurface area for the adsorption of fungi and nitrifying bacteriaTemperatureRetention timeSunlightTotal dissolved solids (TDS)Toxic elements and compoundsVolume of sludge blanketWater currentsWind

cBOD carbonaceous biochemical oxygen demand nBOD nitrogenous biochemical oxygen demand

IntroductIon 9

Nematode

Protozoa Algae

Rotifers

Daphnia

Bacteria

Figure 14 Food web in a facultative lagoon Significant organisms in a facultative lagoon that perform direct or indirect roles in the stabilization of wastes are connected by a food web where each organism is a predator andor prey of another organism

Table 16 Dominant microbes in basic types of lagoons

Lagoon Dominate microbes

Aerobic Facultative anaerobic bacteriaAnaerobic Facultative anaerobic bacteria

MethanogensFacultative Algae

Facultative anaerobic bacteriaMethanogensPhotosynthetic bacteria

Inuent Efuent

Inuent Efuent

Figure 15 Series and parallel modes of operation of multiple lagoons In series mode of operation two or more lagoons are operated in ldquotrain-likerdquo fashion where the influent enters only one lagoon and discharges to the next lagoon In parallel mode of operation influent enters at least two lagoons

Part I

Overview

The Biology and Troubleshooting of Facultative Lagoons First Edition Michael H Gerardi copy 2015 John Wiley amp Sons Inc Published 2015 by John Wiley amp Sons Inc

3

1

Lagoons are one of the oldest wastewater treatment systems They consist of inground earthen basins where wastewater is received held for a period of time treated and then discharged (Fig 11) Depending on the composition strength and volume of wastewater to be treated and discharge requirements a predetermined ldquoholdrdquo or retention time for the wastewater is used Although lagoons are simple in design there are many complex biological chemical and physical processes that occur in lagoons There are several different terms for lagoons Many of these terms are used interchangeably These terms include pond oxidation pond polishing pond sewage pond stabilization pond maturation pond and cell Some terms refer to the role of the lagoon in a wastewater treatment process (Table 11)

Lagoons or natural impoundments were used in the United States in the 1920s to capture liquid wastes With increasing knowledge of the wastewater treatment ability of lagoons they were and are used to treat agricultural domestic industrial and municipal wastes and wastewaters

Lagoons became popular in the 1950s Today numerous lagoons and lagoon systems are used especially in rural areas for the treatment of domestic and municipal wastewaters Although performance varies from good to bad lagoons that are properly designed con-structed and operated can produce effluent that meets secondary treatment standards

Lagoons are one of the most popular simplest and least expensive technologies for treating wastewater Lagoons do require relatively large amounts of land For each million gallons per day (MGD) of wastewater approximately 30 acres of lagoon are required for 50 pounds biochemical oxygen demand (BOD) per acre per day Some ldquoonce‐throughrdquo lagoons are as large as 40 MGD

Introduction

4 IntroductIon

Lagoons use natural and energy‐efficient processes to provide low‐cost wastewater treatment and they offer an alternative to more advanced wastewater treatment processes Although lagoons offer many advantages such as reduced maintenance cost when com-pared with other wastewater treatment systems (Table 12) they also have disadvantages such as the requirement for large amounts of land (Table 13)

Lagoons are designed to satisfy a specific site and need The design is based on several factors including type of soil amount of land area required climate quantity and compo-sition of the wastewater to be treated and discharge requirements However lagoon effluent may require additional treatment or polishing to remove pathogens or nutrients

Inuent Aerobic zone

Facultative zone

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

AlgaeEfuent

Figure 11 Facultative lagoon A facultative lagoon has three active microbial zones where wastewater is treated the zones consist of aerobic facultative and anaerobic habitats

Table 11 Terminology for lagoons or ponds

Term Description

Maturation Improves effluent from activated sludge process or trickling filter to tertiary quality principally to reduce the number of pathogens and nutrients

Oxidation Wastewater is purified by sedimentation and aerobic and anaerobic treatmentPolishing Increases the environmental quality of effluent from previous treatmentPrimary Receives raw (unsettled) wastewater and has a sludge layer that is responsible

for methane productionSecondary Receives settled wastewater or effluent from an anaerobic lagoonStabilization An anaerobic facultative or maturation lagoon

Table 12 Advantages of lagoons as compared with more advanced wastewater treatment processes

Can handle intermittent use and shock loads better than other processesInexpensive to constructRelatively small quantity of equipment is neededReduced maintenance costsRelatively simple to operateEffective in removing pathogensEffluent often suitable for irrigation due to high nutrient contentFewer solid‐handling problems

IntroductIon 5

Most lagoons are found in small rural communities Here lagoons often cost less to construct operate and maintain than other wastewater treatment systems Although lagoons require more land than other wastewater treatment systems land is usually more available and affordable in rural areas Because lagoons treat a large variety of wastes they must be properly constructed to prevent soil and groundwater contamination

Wastewater lagoons must be sealed or lined to prevent seepage at the bottom and sidewall of the lagoon to prevent subsurface and groundwater contamination There are several types of liners that are used (i) clay cement and asphalt (ii) synthetic and rubber and (iii) natural Most liners typically perform well for 15 years However premature failure can occur and is usually due to (i) cleaning or dredging operations (ii) membrane puncture (iii) scour of cover material (iv) substandard liner material and (v) weed growth The most commonly used liners for industrial wastewater lagoons include (i) chlorosulfonated polyethylene or Hypalonreg (ii) polypropylene (rPP) (iii) polyvinyl chloride (iv) reinforced linermdashlow density and (v) XR‐5regXR3reg These liners are tolerant of ice buildup and exposure to harsh and prolonged sunlight

Clay liners shrink and swell according to wastewater temperature and wet‐and‐dry conditions However compacted clay liners are susceptible to erosion and vegetative growth in the dike These conditions damage the integrity and strength of the liner and dike

Installation of clay requires proper moisture content and compaction Cement and asphalt liners can crack under temperature change and wet‐and‐dry conditions Synthetic liners are commonly used and usually consist of some type of plastic They require careful installation by an experienced contractor If the liner is properly installed and is not punctured seepage does not occur Synthetic liners are inert and therefore they are often used in lagoons that contain toxic wastes

The clogging of soil pores forms natural liners This occurs due to (i) settled solids (ii) microbial growth and (iii) chemical clogging of the soil due to ionic charges However natural liners tend to be unreliable because these natural modes for forming a natural liner or sealant are dependent on changing characteristics of the wastewater

Large and diverse populations of archaea algae (Fig 12) bacteria and protozoa (Fig 13) are found in lagoons Changes in numbers and dominant groups or species of organisms depend on biotic (biological) and abiotic (chemical and physical) factors (Tables 14 and 15) The most important abiotic factors are (i) composition and strength of the influent (ii) dissolved oxygen (iii) pH (iv) temperature and (v) sunlight

The organisms found in facultative lagoons are more diverse than those found in many other biological wastewater treatment processes including aerated and anaerobic lagoons The

Table 13 Disadvantages of lagoons as compared with more advanced wastewater treatment processes

Less efficient in cold climates than other processesRequire large amounts of landEffluent quality varies with seasonal changes in wastewater temperatureEffluent from facultative lagoons contains algae and may require additional treatment to meet discharge requirementsSeasonal turnover and release of benthic organismsSystem upsets usually result in odor productionIf not properly maintained lagoons can provide a breeding area for midges mosquitoes and other insects

6 IntroductIon

greater diversity of life is due to the highly complex growth conditions in lagoons where algae archaea bacteria crustaceans and rotifers are present in large numbers and perform significant roles Lagoons rely primarily on bacteria to degrade organic (carbonaceous biochemical oxygen demand cBOD) and nitrogenous (nitrogenous biochemical oxygen demand) wastes The biological degradation of wastes is similar to the natural purification of wastes in streams natural ponds and lakes These organisms are components of a food web (Fig 14) where carbon and energy are transferred from one organism to another The interactions between these organisms are complex and they contribute to changes in wastewater chemistry

There are three basic types of lagoons according to microbial activity that are used to degrade organic and nitrogenous wastes The types of lagoons are aerobic (aerated) facultative and anaerobic The biological differences between the lagoons consist of the

(a)

(b)

(c)

(d)

Figure 12 commonly occurring algae in facultative lagoons commonly occurring blue-green algae or cyanobacteria in facultative lagoons include (a) Phormidium (b) Aphanotheca (c) Planktothrix and (d) Aphanizomenon

IntroductIon 7

following (i) the dominant microbes present in the lagoon (Table 16) (ii) the dominant biological reactions that occur in the lagoon and (iii) the depth of the lagoon

Lagoons can be used alone or in combination with other wastewater treatment processes Lagoon systems can consist of a single lagoon or multiple lagoons and may include wastewater recirculation Multiple lagoons can be configured in series or parallel mode of operation (Fig 15)

Paramecium

Strongylidium

Bodo

Vaginicola

Euplotes

ArcellaEpistylis

Pleuromonas

Acineta

Amoeba

Difugia

Opercularia

Figure 13 commonly occurring protozoa in facultative lagoons commonly occurring protozoa in facultative lagoons include the amoebae Arcella Amoeba and Difflugia the flagellates Bodo and Pleuromonas the free-swimming ciliates Paramecium and Strongylidium the crawling ciliates Euplotes the stalk ciliates Epistylis and Opercularia and the suctorian Acineta

8 IntroductIon

Aerobic LAgoon

An aerobic (aerated) lagoon contains dissolved oxygen from surface to bottom and has an average detention time of 3ndash10 days The lagoon usually is 6ndash20 ft deep Oxygen is sup-plied through diffused or mechanical aeration A significant advantage of an aerated lagoon is the small land requirement

Table 14 biotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

Algal growthAvailable nichesBurrowing animalsCarbon dioxide productionCell lysisDenitrificationDominant microbesFood websMethane productionMixed acid productionMutualistic relationshipsNitrificationOxygen productionPhotosynthesisPlant growth (aquatic and terrestrial)Population densitiesPredatorndashprey relationshipsProduction of toxic products including ammonia and hydrogen sulfideSulfur oxidationSulfur reductionSyntrophic relationship

Table 15 Abiotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

AlkalinityEvaporationFlow (quantity and pattern)Ice coverLoadings (cBOD and nBOD)Nutrients (major and minor)pHPrecipitationSurface area for the adsorption of fungi and nitrifying bacteriaTemperatureRetention timeSunlightTotal dissolved solids (TDS)Toxic elements and compoundsVolume of sludge blanketWater currentsWind

cBOD carbonaceous biochemical oxygen demand nBOD nitrogenous biochemical oxygen demand

IntroductIon 9

Nematode

Protozoa Algae

Rotifers

Daphnia

Bacteria

Figure 14 Food web in a facultative lagoon Significant organisms in a facultative lagoon that perform direct or indirect roles in the stabilization of wastes are connected by a food web where each organism is a predator andor prey of another organism

Table 16 Dominant microbes in basic types of lagoons

Lagoon Dominate microbes

Aerobic Facultative anaerobic bacteriaAnaerobic Facultative anaerobic bacteria

MethanogensFacultative Algae

Facultative anaerobic bacteriaMethanogensPhotosynthetic bacteria

Inuent Efuent

Inuent Efuent

Figure 15 Series and parallel modes of operation of multiple lagoons In series mode of operation two or more lagoons are operated in ldquotrain-likerdquo fashion where the influent enters only one lagoon and discharges to the next lagoon In parallel mode of operation influent enters at least two lagoons

The Biology and Troubleshooting of Facultative Lagoons First Edition Michael H Gerardi copy 2015 John Wiley amp Sons Inc Published 2015 by John Wiley amp Sons Inc

3

1

Lagoons are one of the oldest wastewater treatment systems They consist of inground earthen basins where wastewater is received held for a period of time treated and then discharged (Fig 11) Depending on the composition strength and volume of wastewater to be treated and discharge requirements a predetermined ldquoholdrdquo or retention time for the wastewater is used Although lagoons are simple in design there are many complex biological chemical and physical processes that occur in lagoons There are several different terms for lagoons Many of these terms are used interchangeably These terms include pond oxidation pond polishing pond sewage pond stabilization pond maturation pond and cell Some terms refer to the role of the lagoon in a wastewater treatment process (Table 11)

Lagoons or natural impoundments were used in the United States in the 1920s to capture liquid wastes With increasing knowledge of the wastewater treatment ability of lagoons they were and are used to treat agricultural domestic industrial and municipal wastes and wastewaters

Lagoons became popular in the 1950s Today numerous lagoons and lagoon systems are used especially in rural areas for the treatment of domestic and municipal wastewaters Although performance varies from good to bad lagoons that are properly designed con-structed and operated can produce effluent that meets secondary treatment standards

Lagoons are one of the most popular simplest and least expensive technologies for treating wastewater Lagoons do require relatively large amounts of land For each million gallons per day (MGD) of wastewater approximately 30 acres of lagoon are required for 50 pounds biochemical oxygen demand (BOD) per acre per day Some ldquoonce‐throughrdquo lagoons are as large as 40 MGD

Introduction

4 IntroductIon

Lagoons use natural and energy‐efficient processes to provide low‐cost wastewater treatment and they offer an alternative to more advanced wastewater treatment processes Although lagoons offer many advantages such as reduced maintenance cost when com-pared with other wastewater treatment systems (Table 12) they also have disadvantages such as the requirement for large amounts of land (Table 13)

Lagoons are designed to satisfy a specific site and need The design is based on several factors including type of soil amount of land area required climate quantity and compo-sition of the wastewater to be treated and discharge requirements However lagoon effluent may require additional treatment or polishing to remove pathogens or nutrients

Inuent Aerobic zone

Facultative zone

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

AlgaeEfuent

Figure 11 Facultative lagoon A facultative lagoon has three active microbial zones where wastewater is treated the zones consist of aerobic facultative and anaerobic habitats

Table 11 Terminology for lagoons or ponds

Term Description

Maturation Improves effluent from activated sludge process or trickling filter to tertiary quality principally to reduce the number of pathogens and nutrients

Oxidation Wastewater is purified by sedimentation and aerobic and anaerobic treatmentPolishing Increases the environmental quality of effluent from previous treatmentPrimary Receives raw (unsettled) wastewater and has a sludge layer that is responsible

for methane productionSecondary Receives settled wastewater or effluent from an anaerobic lagoonStabilization An anaerobic facultative or maturation lagoon

Table 12 Advantages of lagoons as compared with more advanced wastewater treatment processes

Can handle intermittent use and shock loads better than other processesInexpensive to constructRelatively small quantity of equipment is neededReduced maintenance costsRelatively simple to operateEffective in removing pathogensEffluent often suitable for irrigation due to high nutrient contentFewer solid‐handling problems

IntroductIon 5

Most lagoons are found in small rural communities Here lagoons often cost less to construct operate and maintain than other wastewater treatment systems Although lagoons require more land than other wastewater treatment systems land is usually more available and affordable in rural areas Because lagoons treat a large variety of wastes they must be properly constructed to prevent soil and groundwater contamination

Wastewater lagoons must be sealed or lined to prevent seepage at the bottom and sidewall of the lagoon to prevent subsurface and groundwater contamination There are several types of liners that are used (i) clay cement and asphalt (ii) synthetic and rubber and (iii) natural Most liners typically perform well for 15 years However premature failure can occur and is usually due to (i) cleaning or dredging operations (ii) membrane puncture (iii) scour of cover material (iv) substandard liner material and (v) weed growth The most commonly used liners for industrial wastewater lagoons include (i) chlorosulfonated polyethylene or Hypalonreg (ii) polypropylene (rPP) (iii) polyvinyl chloride (iv) reinforced linermdashlow density and (v) XR‐5regXR3reg These liners are tolerant of ice buildup and exposure to harsh and prolonged sunlight

Clay liners shrink and swell according to wastewater temperature and wet‐and‐dry conditions However compacted clay liners are susceptible to erosion and vegetative growth in the dike These conditions damage the integrity and strength of the liner and dike

Installation of clay requires proper moisture content and compaction Cement and asphalt liners can crack under temperature change and wet‐and‐dry conditions Synthetic liners are commonly used and usually consist of some type of plastic They require careful installation by an experienced contractor If the liner is properly installed and is not punctured seepage does not occur Synthetic liners are inert and therefore they are often used in lagoons that contain toxic wastes

The clogging of soil pores forms natural liners This occurs due to (i) settled solids (ii) microbial growth and (iii) chemical clogging of the soil due to ionic charges However natural liners tend to be unreliable because these natural modes for forming a natural liner or sealant are dependent on changing characteristics of the wastewater

Large and diverse populations of archaea algae (Fig 12) bacteria and protozoa (Fig 13) are found in lagoons Changes in numbers and dominant groups or species of organisms depend on biotic (biological) and abiotic (chemical and physical) factors (Tables 14 and 15) The most important abiotic factors are (i) composition and strength of the influent (ii) dissolved oxygen (iii) pH (iv) temperature and (v) sunlight

The organisms found in facultative lagoons are more diverse than those found in many other biological wastewater treatment processes including aerated and anaerobic lagoons The

Table 13 Disadvantages of lagoons as compared with more advanced wastewater treatment processes

Less efficient in cold climates than other processesRequire large amounts of landEffluent quality varies with seasonal changes in wastewater temperatureEffluent from facultative lagoons contains algae and may require additional treatment to meet discharge requirementsSeasonal turnover and release of benthic organismsSystem upsets usually result in odor productionIf not properly maintained lagoons can provide a breeding area for midges mosquitoes and other insects

6 IntroductIon

greater diversity of life is due to the highly complex growth conditions in lagoons where algae archaea bacteria crustaceans and rotifers are present in large numbers and perform significant roles Lagoons rely primarily on bacteria to degrade organic (carbonaceous biochemical oxygen demand cBOD) and nitrogenous (nitrogenous biochemical oxygen demand) wastes The biological degradation of wastes is similar to the natural purification of wastes in streams natural ponds and lakes These organisms are components of a food web (Fig 14) where carbon and energy are transferred from one organism to another The interactions between these organisms are complex and they contribute to changes in wastewater chemistry

There are three basic types of lagoons according to microbial activity that are used to degrade organic and nitrogenous wastes The types of lagoons are aerobic (aerated) facultative and anaerobic The biological differences between the lagoons consist of the

(a)

(b)

(c)

(d)

Figure 12 commonly occurring algae in facultative lagoons commonly occurring blue-green algae or cyanobacteria in facultative lagoons include (a) Phormidium (b) Aphanotheca (c) Planktothrix and (d) Aphanizomenon

IntroductIon 7

following (i) the dominant microbes present in the lagoon (Table 16) (ii) the dominant biological reactions that occur in the lagoon and (iii) the depth of the lagoon

Lagoons can be used alone or in combination with other wastewater treatment processes Lagoon systems can consist of a single lagoon or multiple lagoons and may include wastewater recirculation Multiple lagoons can be configured in series or parallel mode of operation (Fig 15)

Paramecium

Strongylidium

Bodo

Vaginicola

Euplotes

ArcellaEpistylis

Pleuromonas

Acineta

Amoeba

Difugia

Opercularia

Figure 13 commonly occurring protozoa in facultative lagoons commonly occurring protozoa in facultative lagoons include the amoebae Arcella Amoeba and Difflugia the flagellates Bodo and Pleuromonas the free-swimming ciliates Paramecium and Strongylidium the crawling ciliates Euplotes the stalk ciliates Epistylis and Opercularia and the suctorian Acineta

8 IntroductIon

Aerobic LAgoon

An aerobic (aerated) lagoon contains dissolved oxygen from surface to bottom and has an average detention time of 3ndash10 days The lagoon usually is 6ndash20 ft deep Oxygen is sup-plied through diffused or mechanical aeration A significant advantage of an aerated lagoon is the small land requirement

Table 14 biotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

Algal growthAvailable nichesBurrowing animalsCarbon dioxide productionCell lysisDenitrificationDominant microbesFood websMethane productionMixed acid productionMutualistic relationshipsNitrificationOxygen productionPhotosynthesisPlant growth (aquatic and terrestrial)Population densitiesPredatorndashprey relationshipsProduction of toxic products including ammonia and hydrogen sulfideSulfur oxidationSulfur reductionSyntrophic relationship

Table 15 Abiotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

AlkalinityEvaporationFlow (quantity and pattern)Ice coverLoadings (cBOD and nBOD)Nutrients (major and minor)pHPrecipitationSurface area for the adsorption of fungi and nitrifying bacteriaTemperatureRetention timeSunlightTotal dissolved solids (TDS)Toxic elements and compoundsVolume of sludge blanketWater currentsWind

cBOD carbonaceous biochemical oxygen demand nBOD nitrogenous biochemical oxygen demand

IntroductIon 9

Nematode

Protozoa Algae

Rotifers

Daphnia

Bacteria

Figure 14 Food web in a facultative lagoon Significant organisms in a facultative lagoon that perform direct or indirect roles in the stabilization of wastes are connected by a food web where each organism is a predator andor prey of another organism

Table 16 Dominant microbes in basic types of lagoons

Lagoon Dominate microbes

Aerobic Facultative anaerobic bacteriaAnaerobic Facultative anaerobic bacteria

MethanogensFacultative Algae

Facultative anaerobic bacteriaMethanogensPhotosynthetic bacteria

Inuent Efuent

Inuent Efuent

Figure 15 Series and parallel modes of operation of multiple lagoons In series mode of operation two or more lagoons are operated in ldquotrain-likerdquo fashion where the influent enters only one lagoon and discharges to the next lagoon In parallel mode of operation influent enters at least two lagoons

4 IntroductIon

Lagoons use natural and energy‐efficient processes to provide low‐cost wastewater treatment and they offer an alternative to more advanced wastewater treatment processes Although lagoons offer many advantages such as reduced maintenance cost when com-pared with other wastewater treatment systems (Table 12) they also have disadvantages such as the requirement for large amounts of land (Table 13)

Lagoons are designed to satisfy a specific site and need The design is based on several factors including type of soil amount of land area required climate quantity and compo-sition of the wastewater to be treated and discharge requirements However lagoon effluent may require additional treatment or polishing to remove pathogens or nutrients

Inuent Aerobic zone

Facultative zone

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

Anaerobic zonesludgeblanket

AlgaeEfuent

Figure 11 Facultative lagoon A facultative lagoon has three active microbial zones where wastewater is treated the zones consist of aerobic facultative and anaerobic habitats

Table 11 Terminology for lagoons or ponds

Term Description

Maturation Improves effluent from activated sludge process or trickling filter to tertiary quality principally to reduce the number of pathogens and nutrients

Oxidation Wastewater is purified by sedimentation and aerobic and anaerobic treatmentPolishing Increases the environmental quality of effluent from previous treatmentPrimary Receives raw (unsettled) wastewater and has a sludge layer that is responsible

for methane productionSecondary Receives settled wastewater or effluent from an anaerobic lagoonStabilization An anaerobic facultative or maturation lagoon

Table 12 Advantages of lagoons as compared with more advanced wastewater treatment processes

Can handle intermittent use and shock loads better than other processesInexpensive to constructRelatively small quantity of equipment is neededReduced maintenance costsRelatively simple to operateEffective in removing pathogensEffluent often suitable for irrigation due to high nutrient contentFewer solid‐handling problems

IntroductIon 5

Most lagoons are found in small rural communities Here lagoons often cost less to construct operate and maintain than other wastewater treatment systems Although lagoons require more land than other wastewater treatment systems land is usually more available and affordable in rural areas Because lagoons treat a large variety of wastes they must be properly constructed to prevent soil and groundwater contamination

Wastewater lagoons must be sealed or lined to prevent seepage at the bottom and sidewall of the lagoon to prevent subsurface and groundwater contamination There are several types of liners that are used (i) clay cement and asphalt (ii) synthetic and rubber and (iii) natural Most liners typically perform well for 15 years However premature failure can occur and is usually due to (i) cleaning or dredging operations (ii) membrane puncture (iii) scour of cover material (iv) substandard liner material and (v) weed growth The most commonly used liners for industrial wastewater lagoons include (i) chlorosulfonated polyethylene or Hypalonreg (ii) polypropylene (rPP) (iii) polyvinyl chloride (iv) reinforced linermdashlow density and (v) XR‐5regXR3reg These liners are tolerant of ice buildup and exposure to harsh and prolonged sunlight

Clay liners shrink and swell according to wastewater temperature and wet‐and‐dry conditions However compacted clay liners are susceptible to erosion and vegetative growth in the dike These conditions damage the integrity and strength of the liner and dike

Installation of clay requires proper moisture content and compaction Cement and asphalt liners can crack under temperature change and wet‐and‐dry conditions Synthetic liners are commonly used and usually consist of some type of plastic They require careful installation by an experienced contractor If the liner is properly installed and is not punctured seepage does not occur Synthetic liners are inert and therefore they are often used in lagoons that contain toxic wastes

The clogging of soil pores forms natural liners This occurs due to (i) settled solids (ii) microbial growth and (iii) chemical clogging of the soil due to ionic charges However natural liners tend to be unreliable because these natural modes for forming a natural liner or sealant are dependent on changing characteristics of the wastewater

Large and diverse populations of archaea algae (Fig 12) bacteria and protozoa (Fig 13) are found in lagoons Changes in numbers and dominant groups or species of organisms depend on biotic (biological) and abiotic (chemical and physical) factors (Tables 14 and 15) The most important abiotic factors are (i) composition and strength of the influent (ii) dissolved oxygen (iii) pH (iv) temperature and (v) sunlight

The organisms found in facultative lagoons are more diverse than those found in many other biological wastewater treatment processes including aerated and anaerobic lagoons The

Table 13 Disadvantages of lagoons as compared with more advanced wastewater treatment processes

Less efficient in cold climates than other processesRequire large amounts of landEffluent quality varies with seasonal changes in wastewater temperatureEffluent from facultative lagoons contains algae and may require additional treatment to meet discharge requirementsSeasonal turnover and release of benthic organismsSystem upsets usually result in odor productionIf not properly maintained lagoons can provide a breeding area for midges mosquitoes and other insects

6 IntroductIon

greater diversity of life is due to the highly complex growth conditions in lagoons where algae archaea bacteria crustaceans and rotifers are present in large numbers and perform significant roles Lagoons rely primarily on bacteria to degrade organic (carbonaceous biochemical oxygen demand cBOD) and nitrogenous (nitrogenous biochemical oxygen demand) wastes The biological degradation of wastes is similar to the natural purification of wastes in streams natural ponds and lakes These organisms are components of a food web (Fig 14) where carbon and energy are transferred from one organism to another The interactions between these organisms are complex and they contribute to changes in wastewater chemistry

There are three basic types of lagoons according to microbial activity that are used to degrade organic and nitrogenous wastes The types of lagoons are aerobic (aerated) facultative and anaerobic The biological differences between the lagoons consist of the

(a)

(b)

(c)

(d)

Figure 12 commonly occurring algae in facultative lagoons commonly occurring blue-green algae or cyanobacteria in facultative lagoons include (a) Phormidium (b) Aphanotheca (c) Planktothrix and (d) Aphanizomenon

IntroductIon 7

following (i) the dominant microbes present in the lagoon (Table 16) (ii) the dominant biological reactions that occur in the lagoon and (iii) the depth of the lagoon

Lagoons can be used alone or in combination with other wastewater treatment processes Lagoon systems can consist of a single lagoon or multiple lagoons and may include wastewater recirculation Multiple lagoons can be configured in series or parallel mode of operation (Fig 15)

Paramecium

Strongylidium

Bodo

Vaginicola

Euplotes

ArcellaEpistylis

Pleuromonas

Acineta

Amoeba

Difugia

Opercularia

Figure 13 commonly occurring protozoa in facultative lagoons commonly occurring protozoa in facultative lagoons include the amoebae Arcella Amoeba and Difflugia the flagellates Bodo and Pleuromonas the free-swimming ciliates Paramecium and Strongylidium the crawling ciliates Euplotes the stalk ciliates Epistylis and Opercularia and the suctorian Acineta

8 IntroductIon

Aerobic LAgoon

An aerobic (aerated) lagoon contains dissolved oxygen from surface to bottom and has an average detention time of 3ndash10 days The lagoon usually is 6ndash20 ft deep Oxygen is sup-plied through diffused or mechanical aeration A significant advantage of an aerated lagoon is the small land requirement

Table 14 biotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

Algal growthAvailable nichesBurrowing animalsCarbon dioxide productionCell lysisDenitrificationDominant microbesFood websMethane productionMixed acid productionMutualistic relationshipsNitrificationOxygen productionPhotosynthesisPlant growth (aquatic and terrestrial)Population densitiesPredatorndashprey relationshipsProduction of toxic products including ammonia and hydrogen sulfideSulfur oxidationSulfur reductionSyntrophic relationship

Table 15 Abiotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

AlkalinityEvaporationFlow (quantity and pattern)Ice coverLoadings (cBOD and nBOD)Nutrients (major and minor)pHPrecipitationSurface area for the adsorption of fungi and nitrifying bacteriaTemperatureRetention timeSunlightTotal dissolved solids (TDS)Toxic elements and compoundsVolume of sludge blanketWater currentsWind

cBOD carbonaceous biochemical oxygen demand nBOD nitrogenous biochemical oxygen demand

IntroductIon 9

Nematode

Protozoa Algae

Rotifers

Daphnia

Bacteria

Figure 14 Food web in a facultative lagoon Significant organisms in a facultative lagoon that perform direct or indirect roles in the stabilization of wastes are connected by a food web where each organism is a predator andor prey of another organism

Table 16 Dominant microbes in basic types of lagoons

Lagoon Dominate microbes

Aerobic Facultative anaerobic bacteriaAnaerobic Facultative anaerobic bacteria

MethanogensFacultative Algae

Facultative anaerobic bacteriaMethanogensPhotosynthetic bacteria

Inuent Efuent

Inuent Efuent

Figure 15 Series and parallel modes of operation of multiple lagoons In series mode of operation two or more lagoons are operated in ldquotrain-likerdquo fashion where the influent enters only one lagoon and discharges to the next lagoon In parallel mode of operation influent enters at least two lagoons

IntroductIon 5

Most lagoons are found in small rural communities Here lagoons often cost less to construct operate and maintain than other wastewater treatment systems Although lagoons require more land than other wastewater treatment systems land is usually more available and affordable in rural areas Because lagoons treat a large variety of wastes they must be properly constructed to prevent soil and groundwater contamination

Wastewater lagoons must be sealed or lined to prevent seepage at the bottom and sidewall of the lagoon to prevent subsurface and groundwater contamination There are several types of liners that are used (i) clay cement and asphalt (ii) synthetic and rubber and (iii) natural Most liners typically perform well for 15 years However premature failure can occur and is usually due to (i) cleaning or dredging operations (ii) membrane puncture (iii) scour of cover material (iv) substandard liner material and (v) weed growth The most commonly used liners for industrial wastewater lagoons include (i) chlorosulfonated polyethylene or Hypalonreg (ii) polypropylene (rPP) (iii) polyvinyl chloride (iv) reinforced linermdashlow density and (v) XR‐5regXR3reg These liners are tolerant of ice buildup and exposure to harsh and prolonged sunlight

Clay liners shrink and swell according to wastewater temperature and wet‐and‐dry conditions However compacted clay liners are susceptible to erosion and vegetative growth in the dike These conditions damage the integrity and strength of the liner and dike

Installation of clay requires proper moisture content and compaction Cement and asphalt liners can crack under temperature change and wet‐and‐dry conditions Synthetic liners are commonly used and usually consist of some type of plastic They require careful installation by an experienced contractor If the liner is properly installed and is not punctured seepage does not occur Synthetic liners are inert and therefore they are often used in lagoons that contain toxic wastes

The clogging of soil pores forms natural liners This occurs due to (i) settled solids (ii) microbial growth and (iii) chemical clogging of the soil due to ionic charges However natural liners tend to be unreliable because these natural modes for forming a natural liner or sealant are dependent on changing characteristics of the wastewater

Large and diverse populations of archaea algae (Fig 12) bacteria and protozoa (Fig 13) are found in lagoons Changes in numbers and dominant groups or species of organisms depend on biotic (biological) and abiotic (chemical and physical) factors (Tables 14 and 15) The most important abiotic factors are (i) composition and strength of the influent (ii) dissolved oxygen (iii) pH (iv) temperature and (v) sunlight

The organisms found in facultative lagoons are more diverse than those found in many other biological wastewater treatment processes including aerated and anaerobic lagoons The

Table 13 Disadvantages of lagoons as compared with more advanced wastewater treatment processes

Less efficient in cold climates than other processesRequire large amounts of landEffluent quality varies with seasonal changes in wastewater temperatureEffluent from facultative lagoons contains algae and may require additional treatment to meet discharge requirementsSeasonal turnover and release of benthic organismsSystem upsets usually result in odor productionIf not properly maintained lagoons can provide a breeding area for midges mosquitoes and other insects

6 IntroductIon

greater diversity of life is due to the highly complex growth conditions in lagoons where algae archaea bacteria crustaceans and rotifers are present in large numbers and perform significant roles Lagoons rely primarily on bacteria to degrade organic (carbonaceous biochemical oxygen demand cBOD) and nitrogenous (nitrogenous biochemical oxygen demand) wastes The biological degradation of wastes is similar to the natural purification of wastes in streams natural ponds and lakes These organisms are components of a food web (Fig 14) where carbon and energy are transferred from one organism to another The interactions between these organisms are complex and they contribute to changes in wastewater chemistry

There are three basic types of lagoons according to microbial activity that are used to degrade organic and nitrogenous wastes The types of lagoons are aerobic (aerated) facultative and anaerobic The biological differences between the lagoons consist of the

(a)

(b)

(c)

(d)

Figure 12 commonly occurring algae in facultative lagoons commonly occurring blue-green algae or cyanobacteria in facultative lagoons include (a) Phormidium (b) Aphanotheca (c) Planktothrix and (d) Aphanizomenon

IntroductIon 7

following (i) the dominant microbes present in the lagoon (Table 16) (ii) the dominant biological reactions that occur in the lagoon and (iii) the depth of the lagoon

Lagoons can be used alone or in combination with other wastewater treatment processes Lagoon systems can consist of a single lagoon or multiple lagoons and may include wastewater recirculation Multiple lagoons can be configured in series or parallel mode of operation (Fig 15)

Paramecium

Strongylidium

Bodo

Vaginicola

Euplotes

ArcellaEpistylis

Pleuromonas

Acineta

Amoeba

Difugia

Opercularia

Figure 13 commonly occurring protozoa in facultative lagoons commonly occurring protozoa in facultative lagoons include the amoebae Arcella Amoeba and Difflugia the flagellates Bodo and Pleuromonas the free-swimming ciliates Paramecium and Strongylidium the crawling ciliates Euplotes the stalk ciliates Epistylis and Opercularia and the suctorian Acineta

8 IntroductIon

Aerobic LAgoon

An aerobic (aerated) lagoon contains dissolved oxygen from surface to bottom and has an average detention time of 3ndash10 days The lagoon usually is 6ndash20 ft deep Oxygen is sup-plied through diffused or mechanical aeration A significant advantage of an aerated lagoon is the small land requirement

Table 14 biotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

Algal growthAvailable nichesBurrowing animalsCarbon dioxide productionCell lysisDenitrificationDominant microbesFood websMethane productionMixed acid productionMutualistic relationshipsNitrificationOxygen productionPhotosynthesisPlant growth (aquatic and terrestrial)Population densitiesPredatorndashprey relationshipsProduction of toxic products including ammonia and hydrogen sulfideSulfur oxidationSulfur reductionSyntrophic relationship

Table 15 Abiotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

AlkalinityEvaporationFlow (quantity and pattern)Ice coverLoadings (cBOD and nBOD)Nutrients (major and minor)pHPrecipitationSurface area for the adsorption of fungi and nitrifying bacteriaTemperatureRetention timeSunlightTotal dissolved solids (TDS)Toxic elements and compoundsVolume of sludge blanketWater currentsWind

cBOD carbonaceous biochemical oxygen demand nBOD nitrogenous biochemical oxygen demand

IntroductIon 9

Nematode

Protozoa Algae

Rotifers

Daphnia

Bacteria

Figure 14 Food web in a facultative lagoon Significant organisms in a facultative lagoon that perform direct or indirect roles in the stabilization of wastes are connected by a food web where each organism is a predator andor prey of another organism

Table 16 Dominant microbes in basic types of lagoons

Lagoon Dominate microbes

Aerobic Facultative anaerobic bacteriaAnaerobic Facultative anaerobic bacteria

MethanogensFacultative Algae

Facultative anaerobic bacteriaMethanogensPhotosynthetic bacteria

Inuent Efuent

Inuent Efuent

Figure 15 Series and parallel modes of operation of multiple lagoons In series mode of operation two or more lagoons are operated in ldquotrain-likerdquo fashion where the influent enters only one lagoon and discharges to the next lagoon In parallel mode of operation influent enters at least two lagoons

6 IntroductIon

greater diversity of life is due to the highly complex growth conditions in lagoons where algae archaea bacteria crustaceans and rotifers are present in large numbers and perform significant roles Lagoons rely primarily on bacteria to degrade organic (carbonaceous biochemical oxygen demand cBOD) and nitrogenous (nitrogenous biochemical oxygen demand) wastes The biological degradation of wastes is similar to the natural purification of wastes in streams natural ponds and lakes These organisms are components of a food web (Fig 14) where carbon and energy are transferred from one organism to another The interactions between these organisms are complex and they contribute to changes in wastewater chemistry

There are three basic types of lagoons according to microbial activity that are used to degrade organic and nitrogenous wastes The types of lagoons are aerobic (aerated) facultative and anaerobic The biological differences between the lagoons consist of the

(a)

(b)

(c)

(d)

Figure 12 commonly occurring algae in facultative lagoons commonly occurring blue-green algae or cyanobacteria in facultative lagoons include (a) Phormidium (b) Aphanotheca (c) Planktothrix and (d) Aphanizomenon

IntroductIon 7

following (i) the dominant microbes present in the lagoon (Table 16) (ii) the dominant biological reactions that occur in the lagoon and (iii) the depth of the lagoon

Lagoons can be used alone or in combination with other wastewater treatment processes Lagoon systems can consist of a single lagoon or multiple lagoons and may include wastewater recirculation Multiple lagoons can be configured in series or parallel mode of operation (Fig 15)

Paramecium

Strongylidium

Bodo

Vaginicola

Euplotes

ArcellaEpistylis

Pleuromonas

Acineta

Amoeba

Difugia

Opercularia

Figure 13 commonly occurring protozoa in facultative lagoons commonly occurring protozoa in facultative lagoons include the amoebae Arcella Amoeba and Difflugia the flagellates Bodo and Pleuromonas the free-swimming ciliates Paramecium and Strongylidium the crawling ciliates Euplotes the stalk ciliates Epistylis and Opercularia and the suctorian Acineta

8 IntroductIon

Aerobic LAgoon

An aerobic (aerated) lagoon contains dissolved oxygen from surface to bottom and has an average detention time of 3ndash10 days The lagoon usually is 6ndash20 ft deep Oxygen is sup-plied through diffused or mechanical aeration A significant advantage of an aerated lagoon is the small land requirement

Table 14 biotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

Algal growthAvailable nichesBurrowing animalsCarbon dioxide productionCell lysisDenitrificationDominant microbesFood websMethane productionMixed acid productionMutualistic relationshipsNitrificationOxygen productionPhotosynthesisPlant growth (aquatic and terrestrial)Population densitiesPredatorndashprey relationshipsProduction of toxic products including ammonia and hydrogen sulfideSulfur oxidationSulfur reductionSyntrophic relationship

Table 15 Abiotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

AlkalinityEvaporationFlow (quantity and pattern)Ice coverLoadings (cBOD and nBOD)Nutrients (major and minor)pHPrecipitationSurface area for the adsorption of fungi and nitrifying bacteriaTemperatureRetention timeSunlightTotal dissolved solids (TDS)Toxic elements and compoundsVolume of sludge blanketWater currentsWind

cBOD carbonaceous biochemical oxygen demand nBOD nitrogenous biochemical oxygen demand

IntroductIon 9

Nematode

Protozoa Algae

Rotifers

Daphnia

Bacteria

Figure 14 Food web in a facultative lagoon Significant organisms in a facultative lagoon that perform direct or indirect roles in the stabilization of wastes are connected by a food web where each organism is a predator andor prey of another organism

Table 16 Dominant microbes in basic types of lagoons

Lagoon Dominate microbes

Aerobic Facultative anaerobic bacteriaAnaerobic Facultative anaerobic bacteria

MethanogensFacultative Algae

Facultative anaerobic bacteriaMethanogensPhotosynthetic bacteria

Inuent Efuent

Inuent Efuent

Figure 15 Series and parallel modes of operation of multiple lagoons In series mode of operation two or more lagoons are operated in ldquotrain-likerdquo fashion where the influent enters only one lagoon and discharges to the next lagoon In parallel mode of operation influent enters at least two lagoons

IntroductIon 7

following (i) the dominant microbes present in the lagoon (Table 16) (ii) the dominant biological reactions that occur in the lagoon and (iii) the depth of the lagoon

Lagoons can be used alone or in combination with other wastewater treatment processes Lagoon systems can consist of a single lagoon or multiple lagoons and may include wastewater recirculation Multiple lagoons can be configured in series or parallel mode of operation (Fig 15)

Paramecium

Strongylidium

Bodo

Vaginicola

Euplotes

ArcellaEpistylis

Pleuromonas

Acineta

Amoeba

Difugia

Opercularia

Figure 13 commonly occurring protozoa in facultative lagoons commonly occurring protozoa in facultative lagoons include the amoebae Arcella Amoeba and Difflugia the flagellates Bodo and Pleuromonas the free-swimming ciliates Paramecium and Strongylidium the crawling ciliates Euplotes the stalk ciliates Epistylis and Opercularia and the suctorian Acineta

8 IntroductIon

Aerobic LAgoon

An aerobic (aerated) lagoon contains dissolved oxygen from surface to bottom and has an average detention time of 3ndash10 days The lagoon usually is 6ndash20 ft deep Oxygen is sup-plied through diffused or mechanical aeration A significant advantage of an aerated lagoon is the small land requirement

Table 14 biotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

Algal growthAvailable nichesBurrowing animalsCarbon dioxide productionCell lysisDenitrificationDominant microbesFood websMethane productionMixed acid productionMutualistic relationshipsNitrificationOxygen productionPhotosynthesisPlant growth (aquatic and terrestrial)Population densitiesPredatorndashprey relationshipsProduction of toxic products including ammonia and hydrogen sulfideSulfur oxidationSulfur reductionSyntrophic relationship

Table 15 Abiotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

AlkalinityEvaporationFlow (quantity and pattern)Ice coverLoadings (cBOD and nBOD)Nutrients (major and minor)pHPrecipitationSurface area for the adsorption of fungi and nitrifying bacteriaTemperatureRetention timeSunlightTotal dissolved solids (TDS)Toxic elements and compoundsVolume of sludge blanketWater currentsWind

cBOD carbonaceous biochemical oxygen demand nBOD nitrogenous biochemical oxygen demand

IntroductIon 9

Nematode

Protozoa Algae

Rotifers

Daphnia

Bacteria

Figure 14 Food web in a facultative lagoon Significant organisms in a facultative lagoon that perform direct or indirect roles in the stabilization of wastes are connected by a food web where each organism is a predator andor prey of another organism

Table 16 Dominant microbes in basic types of lagoons

Lagoon Dominate microbes

Aerobic Facultative anaerobic bacteriaAnaerobic Facultative anaerobic bacteria

MethanogensFacultative Algae

Facultative anaerobic bacteriaMethanogensPhotosynthetic bacteria

Inuent Efuent

Inuent Efuent

Figure 15 Series and parallel modes of operation of multiple lagoons In series mode of operation two or more lagoons are operated in ldquotrain-likerdquo fashion where the influent enters only one lagoon and discharges to the next lagoon In parallel mode of operation influent enters at least two lagoons

8 IntroductIon

Aerobic LAgoon

An aerobic (aerated) lagoon contains dissolved oxygen from surface to bottom and has an average detention time of 3ndash10 days The lagoon usually is 6ndash20 ft deep Oxygen is sup-plied through diffused or mechanical aeration A significant advantage of an aerated lagoon is the small land requirement

Table 14 biotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

Algal growthAvailable nichesBurrowing animalsCarbon dioxide productionCell lysisDenitrificationDominant microbesFood websMethane productionMixed acid productionMutualistic relationshipsNitrificationOxygen productionPhotosynthesisPlant growth (aquatic and terrestrial)Population densitiesPredatorndashprey relationshipsProduction of toxic products including ammonia and hydrogen sulfideSulfur oxidationSulfur reductionSyntrophic relationship

Table 15 Abiotic factors affecting changes in numbers and dominant groups of organisms in facultative lagoons

AlkalinityEvaporationFlow (quantity and pattern)Ice coverLoadings (cBOD and nBOD)Nutrients (major and minor)pHPrecipitationSurface area for the adsorption of fungi and nitrifying bacteriaTemperatureRetention timeSunlightTotal dissolved solids (TDS)Toxic elements and compoundsVolume of sludge blanketWater currentsWind

cBOD carbonaceous biochemical oxygen demand nBOD nitrogenous biochemical oxygen demand

IntroductIon 9

Nematode

Protozoa Algae

Rotifers

Daphnia

Bacteria

Figure 14 Food web in a facultative lagoon Significant organisms in a facultative lagoon that perform direct or indirect roles in the stabilization of wastes are connected by a food web where each organism is a predator andor prey of another organism

Table 16 Dominant microbes in basic types of lagoons

Lagoon Dominate microbes

Aerobic Facultative anaerobic bacteriaAnaerobic Facultative anaerobic bacteria

MethanogensFacultative Algae

Facultative anaerobic bacteriaMethanogensPhotosynthetic bacteria

Inuent Efuent

Inuent Efuent

Figure 15 Series and parallel modes of operation of multiple lagoons In series mode of operation two or more lagoons are operated in ldquotrain-likerdquo fashion where the influent enters only one lagoon and discharges to the next lagoon In parallel mode of operation influent enters at least two lagoons

IntroductIon 9

Nematode

Protozoa Algae

Rotifers

Daphnia

Bacteria

Figure 14 Food web in a facultative lagoon Significant organisms in a facultative lagoon that perform direct or indirect roles in the stabilization of wastes are connected by a food web where each organism is a predator andor prey of another organism

Table 16 Dominant microbes in basic types of lagoons

Lagoon Dominate microbes

Aerobic Facultative anaerobic bacteriaAnaerobic Facultative anaerobic bacteria

MethanogensFacultative Algae

Facultative anaerobic bacteriaMethanogensPhotosynthetic bacteria

Inuent Efuent

Inuent Efuent

Figure 15 Series and parallel modes of operation of multiple lagoons In series mode of operation two or more lagoons are operated in ldquotrain-likerdquo fashion where the influent enters only one lagoon and discharges to the next lagoon In parallel mode of operation influent enters at least two lagoons