Application of a holistic approach for the selection of wastewater treatment technologiesAJ MacDonald1, Nobel Rovirosa1, Onita Basu2

1 Water/Wastewater Department, Infrastructure Business Unit, WorleyParsons Calgary, Calgary, Alberta2 Carleton University, Ottawa, Ontario

2 5-May-09

Wastewater TreatmentFrom this….

3 5-May-09

To this

4 5-May-09

How do we get there?

5 5-May-09

Identify Risks and Opportunities

LOW

HIGH COST OF CHANGES

ABILITY TO INFLUENCE OUTCOME

MIDDLE BEGINNING END

PROJECT LIFECYCLE STAGE

CRITICAL

DECISION

MAKING

6 5-May-09

Introduction – The Holistic Approach

The holistic approach for decision making

Holistic Management: A New Framework for Decision Making by Allan Savory (Author), Jody Butterfield (Author) 1998

7 5-May-09

Environmental/Social

Economic

Technical

What is Holistic?

8 5-May-09

Are we meeting the challenge of delivering water treatment solutions in the changing marketplace?

Why is a Holistic Approach Important?

9 5-May-09

TechnicalEconomicThe Holistic ApproachSynergySocialEnvironmental

IntroductionHolistic Approach and Decision Matrices

10 5-May-09

IntroductionDecision Making Tools

Decision making tools

Pareto AnalysisPaired Comparison AnalysisGrid Analysis – Decision Matrix AnalysisDecision TreesPlus-Minus-Interesting (PMI)Force Field AnalysisSix Thinking HatsCost-Benefit Analysis

11 5-May-09

IntroductionHolistic Approach and Decision Matrices

The Decision Matrix

12 5-May-09

STEP 1: Decide on

Parameters

STEP 2:Assign Weights

STEP 3:Evaluate and

Score

STEP 4:Calculate and

Compare

ParametersTechnical:– Space required– Process complexity

Economic– Investment costs– Operational costs

Environmental/Social– Noise/odour– Visual impact

Building a Decision Matrix

13 5-May-09

Introduction

Objective

The objective of this work is to apply a holisticapproach, which employs a decision matrix as a tool, to integrate technical, economic and environmental objectives for the selection of wastewater treatment solutions

14 5-May-09

IntroductionCase Studies

2 Case Studies:

1. Selection of a wastewater treatment process for landfill leachate

2. Selection of polymers for waste activated sludge (WAS) thickening

15 5-May-09

Part 1 Selection of a landfill leachate treatment process

16 5-May-09

Materials & Methods

Part 1 - Selection of a landfill leachate treatment process

Option A. Moving Bed Biofilm Reactor (MBBR). Including stabilization tank, MBBR, secondary clarifier, tertiary treatment with ultra filtration and UV disinfection and aerobic sludge digestion, sludge dewatering with landfill disposal.

17 5-May-09

Materials & Methods

Option B. Sequencing Batch Reactor (SBR). Including stabilization tank, SBR, tertiary treatment with ultra filtration and UV disinfection, aerobic sludge digestion, sludge dewatering with landfill disposal.

Part 1 - Selection of a landfill leachate treatment process

18 5-May-09

Materials & Methods

Option C. High Rate Anaerobic Reactor (HRAR).Including stabilization tank, HRAR combining UASB and AF reactors in a hybrid process, aerobic-anoxic biofilter, secondary clarifier, tertiary treatment with ultra filtration and UV disinfection, sludge dewatering with landfill disposal.

Part 1 - Selection of a landfill leachate treatment process

19 5-May-09

Option A. Moving Bed Biofilm Reactor (MBBR)

Compact design ExpandableLoad responsiveMinimal maintenance

Materials & Methods

Part 1 - Selection of a landfill leachate treatment process

www.cleantech.com/mbbr

20 5-May-09

Option B. Sequencing Batch Reactor (SBR)

Compact design ExpandableCapacity to buffer fluctuatingwastewater chemistry and strength Intelligent control system

Materials & Methods

Part 1 - Selection of a landfill leachate treatment process

www.ircnet.lu/src/request/pictures/sbr_plant.jpg

21 5-May-09

Option C. High Rate Anaerobic Reactor (HRAR)

Resistant to shock loadsCapable of handling variable hydraulic loadsLow operation and maintenance costs Production of biogas for energy

Materials & Methods

Part 1 - Selection of a landfill leachate treatment process

www.engetec.info/wastewater/anaerobic.htm

22 5-May-09

Materials & Methods

Selection of a landfill leachate treatment process – Decision Matrix

23 5-May-09

Results & Discussions

Part 1 - Selection of a landfill leachate treatment processDecision Matrix – Technical

Option A (MBBR)

Option B (SBR)

Option C (HRAR)

Score Score ScoreApplicability 5 5 3

Durability 3 3 3

Area required 5 5 3

Design/build complexity 3 1 3

Process complexity 3 1 3

Process reliability 5 5 3

Operational flexibility 3 1 3

Energy requirements 3 1 5

Consumables required 5 3 5

Personnel requirements 5 3 3

Subtotal (out of 50) 40 28 34Subtotal (out of 30) 24 16.8 20.4

30 Technical

Weight (%)

General Indicator Specific Indicator

24 5-May-09

Results & Discussions

Decision Matrix - Economic

Option A (MBBR)

Option B (SBR)

Option C (HRAR)

Score Score ScoreInvestment costs 5 1 3

O&M costs 3 3 5

Generation of valuable products 3 3 5

Previous applications 3 5 3

Subtotal (out of 20) 14 12 16Subtotal (out of 35) 24.5 21 28

35 Economic

Weight (%)

General Indicator Specific Indicator

Part 1 - Selection of a landfill leachate treatment process

25 5-May-09

Results & Discussions

Option A (MBBR)

Option B (SBR)

Option C (HRAR)

Score Score ScoreCommunity acceptance 5 3 1

Generation of residuals 3 3 5

Noise generation 3 1 5

Odour generation 3 1 1

Reproduction of vectors 5 5 5

Visual impact 5 5 3

Subtotal (out of 30) 24 18 20

Subtotal (out of 35) 28 21 23.3

35 Environmental

Weight (%)

General Indicator Specific Indicator

Decision Matrix - Environmental

Part 1 - Selection of a landfill leachate treatment process

26 5-May-09

Weight General Indicator Option A (MBBR)

Option B (SBR)

16.821.0

Option C (HRAR)

30% Technical 24.0 20.435% Economic 24.5 28.035% Environmental 28.0 21.0

58.823.3

100% Total (%) 76.5 71.3

Results & Discussions

Part 1 - Selection of a landfill leachate treatment process

27 5-May-09

Part 2 Selection of a polymer for WAS thickening

28 5-May-09

Filtrate

Materials & Methods

Part 2 - Selection of a polymer for waste activated sludge thickening

29 5-May-09

PART 1:BENCH TESTING

8 POLYMERS

PART 2:FULL SCALE TESTING

3 POLYMERS

1

2

Materials & Methods

Part 2 - Selection of a polymer for waste activated sludge thickening

30 5-May-09

Results & Discussions

Selection of a polymer for sludge thickening – Decision Matrix

Phase Parameter Parameter Weight Phase Weight

Thickened Sludge Total Solids 4Total Volatile Solids 1TKN 2Total Phosphorus 2Total BOD 1TOTAL 10 80%

Filtrate Total Solids 1Turbidity 1TKN 2Ammonia 3Total Phosphorous 3TOTAL 10 20%

31 5-May-09

Materials & Methods

Selection of a polymer for waste activated sludge thickening

Where:z is the value of the standardized z-score, in units of standard deviationx is the value of the raw data pointµ is the sample mean of the raw dataσ is the sample standard deviation of the raw data

σμ−

=xz

Converting Values to Z Scores

32 5-May-09

Part 2 - Selection of a polymer for waste activated sludge thickening.

Results & Discussions

0

1

2

3

4

5

6

7

CB 4450

CIBA 75

57SNF 41

40SNF 42

90CIB

A 8160

EC 4925

JC49

JC473

Contro

l

GBT

Polymer (4.5 g polymer/kg sludge solids, n=2)

Perc

ent S

olid

s

33 5-May-09

Results & Discussions

0

200

400

600

800

1000

1200

CB 4450

CIBA 75

57SNF 41

40SNF 42

90CIB

A 8160

EC 4925

JC49

JC473

Contro

l

GBT

Polymer (4.5 g polymer/kg sludge solids, n=2)

Tota

l Pho

spho

rous

(mg/

kg)

Part 2 - Selection of a polymer for waste activated sludge thickening.

34 5-May-09

0

500

1000

1500

2000

2500

3000

3500

4000

CB 4450

CIBA 7557

SNF 4140

SNF 4290

CIBA 8160

EC 4925

JC49

JC473

Contro

l

GBT

Polymer (4.5 g polymer/kg sludge solids, n=2)

TKN

(mg/

kg)

Results & Discussions

Part 2 - Selection of a polymer for waste activated sludge thickening.

35 5-May-09

Results & Discussions

Polymer Thickened Sludge (80%)

Filtrate (20%)

Total

CB 4450 0.8 0.9 1.7

CIBA 7557 3.7 0.1 3.8

SNF 4140 -1.5 -1.1 -2.6

SNF 4290 7.0 -1.0 6.0CIBA 8160 5.0 0.0 5.0EC 4925 5.5 -0.4 5.1JC 49 -10.6 2.0 -8.6

JC 473 -9.3 -1.1 -10.4

Part 2 - Selection of a polymer for waste activated sludge thickening.

36 5-May-09

Balanced Decision Making

Consciously Weighing our Objectives

37 5-May-09

What Does This Cost?

38 5-May-09

Conclusions

Solution for BALANCED decision making

SUPPORT for all types of DECISIONS

Save TIME and MONEY

The Holistic Approach

39 5-May-09

40 5-May-09

Appendix – Sample Calculation

Sample Calculation

Total Solids

Polymer 1 4.58

Polymer 2 5.22

Polymer 3 5.08

average 4.96

st. dev 0.34

Z Score

-1.13

0.77

0.37

4.58 - 4.96

0.34

41 5-May-09

Appendix – Part 2 – Filtrate TP and TKN

0

0.5

1

1.5

2

2.5

3

3.5

CB 4450CIBA 7557

SNF 4140SNF 4290CIBA 8160

EC 4925JC49JC473Contro

lGBT

Polymer (4.5 g polymer/kg sludge solids, n=2)

Tota

l Pho

spho

rous

(mg/

L fil

trat

e)

0

2

4

6

8

10

12

CB 44 50CIBA 7557

SNF 4140SNF 4290CIBA 8160

EC 49 25JC4 9JC4 73Contro

lGBT

Polymer (4.5 g polymer/kg sludge solids, n=2)

TKN

(mg/

L)

Total Phosphorous TKN

N/A N/A

42 5-May-09

Appendix – Part 2 – Materials and Methods

43 5-May-09

Solid and liquid phases were examined with respect to the following parameters:– Solids tests: Total solids, volatile solids, suspended solids,

turbidity– Chemical/nutrient tests: Ammonia nitrogen, total Kjeldahl

nitrogen, total phosphorous, BOD

Samples prepared in triplicate using 4.5 g of polymer per kg sludge solids– 300 mL samples thickened at bench scale for 10 minutes

Appendix – Part 2 – Materials and Methods