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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