Dr. Michael Cooney Hawaii Natural Energy Institute

High Rate Anaerobic Digestion of High Strength Acidic Wastewater at

Demonstration Scale

Dr. Michael Cooney

Hawaii Natural Energy Institute

University of Hawaii

http://www.hnei.hawaii.edu

Value of Wastewater


WWTP

Biogas (CO2, CH4)

Biomass (CHaNbOc)

Cl-1,NO3-1,PO4

-2,SO4-2

Na+,K+,Mg+2,Ca+2

Steroid hormones,

Alkylphenolic compounds,

Perfluorinated chemicals

Electricity

Treated Water

Relative mass ratios of outputs depends greatly upon the process technology

used, including the form of electron acceptor.

Wastewater (3 to 10 MGD)

Water

Carbon

Electrons

Ions

Pharmaceuticals

Energy

Air

Anaerobic Wastewater Treatment


WWTP

Outputs

Water – High

Biogas – Medium to High

Ions – Low to Medium

Electricity – low

Pharmaceuticals – low

Biomass - Low

Inputs

Water – High

Air - Low

Energy - Low

Aerobic Wastewater Treatment


WWTP

Inputs

Water - High

Air - High

Energy - High

Outputs

Water – High

Biomass – Medium High

Ions – Low

Pharmaceuticals – Low

Electricity – Nil

Biogas - Nil

Wastewater Products


The principal product exiting a wastewater treatment plant, in terms

of any logical productivity metric, is treated wastewater.

Historically, treated wastewater has been given little to no positive value,

instead being treated as a negative emission that requires treatment with

high-energy and high chemical inputs prior to its discharge.

Recently, efforts have been made to find “heretofore” undiscovered value

in wastewater in terms of energy as electrons, energy as biogas, high

value chemicals, and even macronutrients.

These efforts, however, are hindered by their low densities – they are

byproducts.

The treatment of wastewater, therefore, remains driven by regulatory

implementation of fines and not the recovery of value added byproducts.


"There are parts of the bay where you are literally inside a

latrine where hundreds of thousands of people defecate daily,"

according to Mario Moscatelli, an independent biologist who

closely monitors pollution in Rio's waterways. Moscatelli says in

addition to sewage, he has documented cadavers, hospital

waste, home electronics and tires in the water” – Taylor Barnes,

Special for USA Today, 2/24/2015http://www.usatoday.com/story/sports/olympics/2015/02/24/rio-de-janeiro-olympic-legacy-

promises/23942105/

With a resident population of over 900,000, and more than

485,500 visitors a month, Honolulu is the largest U.S. city that

does not provide secondary sewage treatment.

Under the 2010 consent decree, the Honouliuli wastewater

treatment plant must be upgraded to secondary treatment by

2024, the Sand Island Plant by 2035.

Lawsuit brought by Sierra Club, Hawai’is Thousand Friends,

and Our Children’s Earth Foundation

Application of Anaerobic Digestion for High-Rate Treatment of

GTW Wastewater

A collaborative research cooperative between


& Pacific Biodiesel


Acknowledgements

Robert King Sam Millington

Kevin Harris Ken Lewis

Ryan Lopez Scott Higgins

Application of Anaerobic Digestion for High-Rate Treatment of

GTW Wastewater

MISSION STATEMENT

To evaluate the application of anaerobic digestion to the treatment of

waste trap grease wastewater as a means to reduce discharge costs

and to produce methane gas for on-site energy use.

RATIONAL

The business of producing biodiesel from waste oil is marginal. The

key merit to this project, therefore, is the application of AD to treat a

pre-existing waste stream (i.e. GTW wastewater) as a means to

reduce the cost of wastewater discharge to sewage and thus improve

the profit margin of biodiesel production.


Anaerobic Digestion of

GTW Wastewater


Gas Box

GTW wastewater Feed

Solids Recycle

A

2X

B

4X

C

4X

Treated Effluent

pH, Temperature

controller

Acid catalyzed DT

Biodiesel

FOG

GTW


GTW Wastewater

Synthetic media GTW Wastewater

pH 7 4.0 - 4.4

Total COD (g L-1) 16.1 15.9 – 21.2

Soluble COD(g L-1) 16.1 13.4 -17.3

Total N (g L-1) 0.66 0.15 - 0.43

Soluble TN (g L-1) 0.66 0.14 - 0.37

TP (g L-1) 2.01 0.24 - 0.97

Soluble TP(g L-1) 2.01 0.19 -0 .79

Soluble TVOA (g L-1) 390 2.9 - 4.3

TSS (g L-1) - 1.8 – 2.8

Total COD/TN 24.4 55.4 – 73.3

Soluble COD/TN 24.4 62.2 - 83.6

Total COD:N:P 100:4.1:12.5 100:0.71:1.13 - 100:2.70:6.10

Soluble COD:N:P 100:4.1:12.5 100:0.81:1.10 - 100:2.76:5.90


Table 1: Characteristics of GTW wastewater.


GTW Wastewater

Packing density (g L-1), System HRT (d), OLR (kg COD m-3 d-1)

25, 3.0; 5.53 25, 2.0, 9.75 25, 1.0, 21.2

HYD R1 R2 HYD R1 R2 HYD R1 R2

pH 5.96 6.95 7.17 6.01 6.89 7.21 5.95 6.97 7.24

TSS (g L-1) 2.75 1.4 0.45 4.8 3.8 0.7 2.6 3.6 2

TSS reduction (g L-1) -45 26 76 -71 -36 75 -8 -50 13

COD (g L-1) 8.6, 3.6(s) 3.0,

0.6(s)

1.0,

0.4(s)

18.5,

10.8(s)

8.5,

2.4(s)

1.6,

0.7(s)

11.7,

8.4(s)

7.8,

2.7(s)

4.0,

1.1(s)

COD reduction (%) 48, 73(s) 82, 96(s) 94, 97(s) 5, 28(s) 56, 84(s) 92, 95(s) 45, 51(s) 63, 84(s) 81, 94(s)

COD reduction (kg

COD m-3 d-1)

2.67;

3.27(s)

4.53,

4.27(s)

5.2,

4.56(s)

0.5,

2.15(s)

5.5,

6.35(s)

8.95,

8.1(s)

9.5,

8.9(s)

13.4,

14.6(s)

17.2,

16.2(s)

TVOA (mg L-1) 1.275 (s) 0.149 (s) 0.044 (s) 2.798(s) 0.498(s) 0.080(s) 2.834(s) 0.980(s) 0.313(s)

TVOA reduced (%) 57 95 99 34 88 98 15 71 91

TGPR (m3 m-3 d-1) 1.77 0.852 0.177 2.49 1.38 0.918 5.77 3.12 1.2

CO2 (%) 42 23 22 36 23 22 44 22 19

CH4 (%) 55 77 70 61 77 78 55 78 81

CH4 (m3 m-3 d-1) 0.974 0.656 0.124 1.52 1.06 0.72 3.17 2.43 0.97

CH4 per CODred (m3

kgCOD-1)

0.34 0.39 0.38


Characteristics of up flow anaerobic fixed film reactor modules on synthetic and GTW wastewater on corn

cob biochar as a function of packing density and organic loading rate at 37ºC.


GTW Wastewater


Figure 3. SEM images of native and biofilm covered corn cob biochar. Graphs: (LHS) 800x

magnification; (RHS) 2000 times magnification.

Phylogentic analysis revealed broad spectrum populations of anaerobic bacteria

that ferment organic substrates to produce acetate, ethanol, and hydrogen as

major end products as well as archaeal populations that produce methane gas

Biofilm Communities


Band Top match (accession number) Identitya Phylum Domain

1 Thermotogaceae strain SulfLac1 (FR850164) 99% Thermotogae Bacteria

2 Spirochaetes clone DhR^2/LM-B02 (HQ012843) 92% Spirochaetes Bacteria

3 Thermotogaceae clone B3112 (HQ133023) 91% Thermotogae Bacteria

4 Pelotomaculum sp. FP (AB159558) 95% Firmicutes (Clostridia) Bacteria

5 Clostridium sp. clone K13-19 (HE862234) 91% Firmicutes (Clostridia) Bacteria

6 Desulfotomaculum thermobenzoicum (AJ294430) 93% Firmicutes (Clostridia) Bacteria

7 Clostridium thermocellum (CP002416) 90% Firmicutes (Clostidia) Bacteria

8 Symbiobacterium sp. clone BL1_11 (JX101989) 99% Firmicutes (Clostridia) Bacteria

9 Symbiobacterium sp. clone BL1_11 (JX101989) 94% Firmicutes (Clostridia) Bacteria

10 Methanobacterium formicicum strain KOR-1

(JX042445)

100% Euryarchaeota

(Methanobacteriales)

Archaea

11 Methanobacteriaceae clone B11-A-115 (JN836424) 100% Euryarchaeota

(Methanobacteriales)

Archaea

12 Methanosaeta sp. clone BUH10-1 (JQ282391) 100% Euryarchaeota

(Methanomicrobia)

Archaea

13 Methanoculleus bourgensis MS2 (HE964772) 97% Euryarchaeota

(Methanomicrobia)

Archaea

A B

DGGE gels showing microbial community profiles for the

bacteria (panel A) and archaea (panel B) in the anaerobic

reactors (R1 and R2) based on 16S rRNA genes. DNA

sequence information was obtained for the numbered

DGGE bands. Lanes i and iii are replicate samples for

Reactor 1, and Lanes ii and iv are for Reactor 2.

Design and Fabrication of

Demonstration Scale HRAD Reactors



Installation of Demonstration Scale

HRAD System

Evaluation of HRAD System

at Demonstration Scale


Total 5-Jul 17-Jul 24-Jul 1-Aug 7-Aug 14-Aug 21-Aug 24-Jun Ave std

COD 12.60 17.00 17.30 16.50 13.60 15.40 15.10

STA

RT

UP

15.36 1.76

N 0.24 0.34 0.42 0.34 0.38 0.33 0.32 0.34 0.06

P 0.15 0.27 0.28 0.24 0.21 0.22 0.15 0.22 0.05

HEM 3.28 1.64 1.86 2.00 3.41 6.84 5.17 3.46 1.93

TSS 1.08 1.04 1.20 1.19 0.89 0.83 1.07 1.04 0.14

pH 4.49 4.58 4.62 4.63 4.61 4.60 4.33 4.55 0.11

COD/N 52.50 42.50 41.20 49.10 35.40 46.40 47.90 45.00 5.72

Table 1. Total characteristics of waste grease trap wastewater feedstock. Total values represents

measurements made on samples without filtering. Units are in g L-1.

Soluble 17-Jul 24-Jul 1-Aug 7-Aug 14-Aug 21-Aug 24-Jun Ave std

COD 12.50 15.20 14.70 12.40 12.80 10.52

STA

RT

UP

13.02 1.70

N 0.28 0.31 0.28 0.31 0.22 0.20 0.27 0.05

P 0.20 0.22 0.16 0.16 0.12 0.09 0.16 0.05

VOA 4.32 4.32 4.50 4.35 3.59 4.68 4.29 0.37

HEM 1.65 2.12 2.17 6.46 4.69 4.74 3.64 1.93

COD/N 44.00 48.70 53.30 39.70 59.30 51.60 49.43 6.95

Table 2. Soluble characteristics of waste grease trap wastewater feedstock. Soluble values represent

measurements made on samples after they were filtered through 1.8 micron Whatman filters. Units

are in g L-1.

Application of Anaerobic Digestion for Treatment of

GTW Wastewater


Figure 3. Performance of packed bed anaerobic reactor as a function of location at day fifty nine after innoculation. Symbols: Open triangles, total COD; open squares, soluble COD; open triangles, total volatile organic acids; crosses, pH.

0

1

2

3

4

5

6

7

8

0

2

4

6

8

10

12

14

16

pHg

L-1

Sample Location

Figure 4: PH profile as a function of location at various times after inoculation. Symbols: Open diamonds, fifty nine days after innoculation; open squares, fifty three days after innoculation; open triangles, twenty eight days after innoculation.

5.5

6

6.5

7

7.5

8

Hydrolysis R1P2 R2P2 Effluent

pH

Sample Location

BIOFILM COMMUNITIES DIFFER FROM

PLANKTONIC COMMUNITIES

Taxa Aqueous (MC 01-05) and Biochar (MC 06-09) samples

Kindom Class Genus MC01 MC02 MC03 MC04 MC05 MC06 MC07 MC08 MC09

Archaea

Methanobacteria

Methanobacteriu

m 0.02 0.19 0.37 0.92 0.68 20.86 19.28 31.08 24.42

Methanobacteria

Methanobrevibact

er 0.00 0.08 0.43 0.49 0.21 3.12 6.79 1.23 1.29

Methanobacteria Methanosarcina 0.00 0.27 1.92 2.22 1.10 1.77 5.97 2.95 3.08

Bacteria

Bacteroidia 0.06 6.99 7.14 3.75 2.39 1.59 4.98 1.09 2.18

Bacteroidia 0.05 12.33 10.06 2.87 3.70 0.00 0.02 0.01 0.04

Bacteroidia 0.00 1.77 5.58 9.74 6.06 0.06 0.30 0.00 0.00

Bacteroidia Prevotella 63.22 20.11 8.27 5.95 7.43 0.00 0.02 0.00 0.00

Bacteroidia 0.00 14.14 7.06 2.83 2.47 0.00 0.00 0.00 0.00

Bacteroidia 0.12 10.93 12.93 9.58 13.80 0.11 0.64 0.08 0.18

Anaerolineae SHD-231 0.00 0.00 0.04 0.16 0.09 7.26 4.66 3.84 2.50

Bacilli Lactobacillus 6.23 0.24 0.05 0.00 0.02 0.00 0.00 0.00 0.00

Clostridia Sporanaerobacter 0.00 0.04 0.13 1.95 2.20 10.48 4.29 2.53 1.97

Clostridia Other 0.00 0.92 5.32 7.20 7.02 0.90 0.83 1.06 0.87

Clostridia Syntrophomonas 0.00 0.10 0.46 3.12 4.53 6.40 8.46 12.31 11.68

Clostridia Megasphaera 7.19 2.73 2.30 0.66 0.57 0.01 0.00 0.00 0.01

Deltaproteobacteria Desulfovibrio 0.01 11.17 8.51 7.73 7.98 0.26 1.60 0.33 0.28

Gammaproteobacte

ria Escherichia 0.06 0.01 0.01 0.06 0.06 9.96 4.19 5.09 1.03

WWE1 W22 0.01 0.00 0.05 0.59 0.91 2.14 6.01 4.53 11.76

Synergistia Aminobacterium 0.00 0.08 0.37 1.53 1.48 11.09 6.87 8.82 10.16


MC01: Feedstock; MC02: Mixing Tank; MC03: Column B WW; MC04: Column C WW; MC05: Treated effluent; MC06: Column

B biochar top; MC07: Column B biochar bottom; MC08: Column C biochar top; MC09: Column C biochar bottom.

Summary


Methanogenic archea grow much slower than acido and acetogenic bacteria; these

differences can be amplified by any number of process variables such as temperature,

pH, and organic loading rate.

The start-up phase is critical to long-term operation of anaerobic digesters. In

particular, failure to achieve a properly balanced methanogenic microbial community

during start up can lead to inefficient operation, indefinite delays or failure.

At lab scale biochar served as an excellent packing material to support the growth

and retention of biofilms rich in active and properly balanced methanogenic microbial

communities.

In this presentation biochar was been shown to excel at demonstration scale under

commercial operating conditions.

Specifically, in the relatively short time of only fifty nine days, the system

achieved excellent performance and developed biofilms that were populated with

active methanogenic microbial communities.

New Research Directions


Hybrid systems that meet EPA discharge limits on BOD5 and TSS

Hybid systems for safe water reuse for food and energy production

New support materials that increase the accessible surface area of active

methanogenic biofilm communities per unit reactor volume

Application of High Rate Anaerobic – Aerobic

Digestion (HRAAD)

A collaborative research project between


Hawaii American Waters

RealGreen Power

AECOM


Acknowledgements

Roger Babcock Rick Rocheleau

Lee Mansfield Rudy Mina,

Dennis Tulang Dennis Furukawa

HRAD Example 1: Treatment of primary clarifier

effluent


FOG enriched Primary Clarifier Effluent

Bionest

Biochar

Bionest/Biochar

Effluent Rxr 1

Air

Effluent Rxr 2

Recycle

1 FT Bionest

Sludge bed Zone

4.5 FT

Bionest/Biochar

0.8 FT Biochar

1.5 FT Bionest

Clarifier Zone

Gas outlet

Recycle


Digestion (HRAAD)


BOD5 = ~ 13.3 g/l < 30 mg/l

TSS = ~ 8.5 g/l < 30 mg/l

EPA Discharge Requirements met at HRT of 7 hours & use of recycle


Digestion (HRAAD)


VHRAD 25000.0 gallons

HRTHRAD 7.0 hours

Qo 3571.4 gph

Qo 85714.3 gpd

Qo 324.4 m3pd

Qo 13.5 m3ph

Qrec1 7142.9 gph

Qrec1 171428.6 gpd

Qrec1 648.9 m3pd

Qrec1 27.0 m3ph

Qrec2 14285.7 gph

Qrec2 342857.1 gpd

Qrec2 1297.7 m3pd

Qrec2 54.1 m3ph

HRTClarifier 2.0 hours

VClarifier 7142.9 gallons

ENERGY

Q Head Voltage Current Power Power

gph ft V Amps Watt kW

P1 (Qrecy1) 3571.4 5 115 2 230 0.23

P2 (Qrecy1) 3571.4 5 115 2 230 0.23

P3 (Qrecy2) 4761.9 20 115 2 230 0.23

P4 (Qrecy2) 4761.9 20 115 2 230 0.23

P5 (Qrecy2) 4761.9 20 115 2 230 0.23

P6 Grinder (Solids recycle) 230 9.8 31.1 0.0

Punit 1181.1 1.18

Energy Balance


Digestion (HRAAD)


PC

PC

PC

AERATION

AERATION

AERATION

CLARIFIERUV

P1

R1 R1 R1 R1R1 R1

R2 R2

R1 R1 R1 R1R1 R1

R2 R2 R2 R2 R2 R2 R2 R2 R2 R2

R1 R1 R1 R1R1 R1

R2 R2

R1 R1 R1 R1R1 R1

R2 R2 R2 R2 R2 R2 R2 R2 R2 R2

R1 R1 R1 R1R1 R1

R2 R2

R1 R1 R1 R1R1 R1

R2 R2 R2 R2 R2 R2 R2 R2 R2 R2

P1

P1

Pair

SANDFILTER

Pras

HEADWORKS

DISCHARGE

Q gpd kWh/day

Exist HKWWTP 3,085,714

Loading (gravity) -

Blower (air) 2,640

RAS 925,714 115

Exist HK total 2,755

RGP HNEI 3,085,714 1,438

Energy Savings 48%

Comparison against

existing activated

sludge plant treating

3.1 MGD

Water Reuse System for food and Energy

Production


COD = 19.8 g/l

Tss = 1.16 g/l

CODred > 90%

Tssred > 60%

CODred > 98%

Tssred > 97.5%

CODred > 99.2%

Tssred > 99.8%

NH4+ ~ 0.37 g/l

NO3- ~ 0.0 g/l

PO42- ~ 0.91 g/l

K+ ~ 0.16 g/l

NH4+ ~ 0.37 g/l

NO3- ~ 0.0 g/l

PO42- ~ 0.91 g/l

K+ ~ 0.16 g/l

NH4+ ~ 0.01 g/l

NO3- ~ 1.06 g/l

PO42- ~ 0.87 g/l

K+ ~ 0.17 g/l

NH4+ ~ 0.0 g/l

NO3- ~ 1.03 g/l

PO42- ~ 0.87 g/l

K+ ~ 0.16 g/l


min0 10 20 30 40 50

nRIU

-5000

0

5000

10000

15000

20000

25000

30000

8.8

34 8

.982

9.1

51 9

.843

12.

040

12.

960

13.

880

14.

966

17.

308

18.

836

19.

531

20.

627 2

2.48

7

26.

382

28.

837

29.

667

32.

197

36.

900

41.

146

44.

221

min0 10 20 30 40 50

nRIU

-5000

0

5000

10000

15000

20000

25000

30000

8.9

78 9

.144

12.

039

12.

970

22.

466

26.

366

29.

203

min0 10 20 30 40 50

nRIU

-5000

0

5000

10000

15000

20000

25000

30000

8.9

74 9

.164

12.

046

12.

968

29.

454

min0 10 20 30 40 50

nRIU

-5000

0

5000

10000

15000

20000

25000

30000

9.0

51

12.

020

12.

972

29.

450

Feed Tank

Hydrolysis reactor

Anaerobic reactor

Aerobic Reactor

Water Reuse System for food and Energy

Production

HPLC

Advanced Biofilm Supports:

Island Biofilms


Documents

Dr. Michael Cooney Hawaii Natural Energy Institute