CSWEA 2013 Comparison of Three Wet Weather Flow Treatment Alternatives to Increase Plant Capacity Don Esping, Denny Parker, Jose Jimenez, Fenghua Yang, Tim Bate, Steve Arant May 16 2013
Milwaukee MSD South Shore Water Reclamation Facility 24 Final Settling Tanks 28 Aeration Basins 16 Primary Settling Tanks Aerated Grit 1 screens
Outline Background/Goals Bench Scale Testing Demonstration Facilities Testing Round 1 Simulated Wet Weather Round 2 Wet Weather Conclusions/Further Testing
Project Background/Goals 2020 Facilities Plan Increase wet weather treatment capacity from 300 mgd to 450 mgd SSO Level of Protection 5 year Ballasted flocculation pilot tested Bio-ballasted flocculation Bench tested Project Goals Demonstrate other non- proprietary processes: Chemically Enhanced Sedimentation (CEPT) Biological Contact Treatment Compressible Media Filtration
Treatment Flow Routing Plant Influent (450 mgd) Primary Settling Tanks (150/300/300 mgd) Compressible Media Filtration (150 mgd) Existing Activated Sludge Process (300/300/300 mgd) Biological Contact Treatment (150 mgd) Disinfection (450 mgd) Flow routing and flow rates Compressible Media Filtration/Biological Contact / Chemically Enhanced Sedimentation
Demonstration Study Effluent Goals Item Units NPDES Permit Operations Contract Demonstration Study Daily Goals Total BOD 5 mg/l 30 a /45 b 15 a 35 Total Suspended Solids mg/l 30 a /45 b 15 a 35 Total Phosphorus mg P/L 1.0 a 1.0 a 1 Ammonia-Nitrogen mg N/L Seasonal 5 a 5 Fecal Coliform c (no./100 ml) 200 100 -- a. Monthly average b. Weekly average c. Geometric mean
Bench-Scale Testing CEPT Cocktail for wet weather and chemical system sizing Biological Contact Treatment Bio-flocculation potential and kinetics ( MLSS and contact time) Simulation of coagulation and/or flocculation processes
180 170 CEPT Bench- Scale Testing Supernatant TSS, mg/l 160 140 120 100 80 60 40 20 Coagulant Only 40 100 Coagulant and Flocculant 27.5 25 30 24 Demonstration Target 40 mg/l ferric chloride 0.5 mg/l anionic polymer 400 0 Control 40 mg/l FeCl3 12.6 mg/l PAX 40 mg/l FeCl3 & 0.46 mg/l A210P 12.6 mg/l PAX & 0.46 mg/l A210P 40 mg/l FeCl3 & 0.4 mg/l CE9307 12.6 mg/l PAX &0.4 mg/l CE9307 350 342 Supernatant COD, mg/l 300 250 200 150 100 50 215 182 168 166 176 174 160 87 70 78 87 76 84 84 84 62 59 37 34 40 48 42 45 0 Diluted raw influent Control 40 mg/l FeCl3 12.6 mg/l PAX 40 mg/l FeCl3 & 0.46 mg/l A210P 12.6 mg/l PAX & 0.46 mg/l A210P 40 mg/l FeCl3 & 0.4 mg/l CE9307 12.6 mg/l PAX &0.4 mg/l CE9307 COD SCOD FFCOD
Biological Contact Treatment High rate biological process which relies on biological flocculation for colloidal & particulate removal No chemical addition required Effluent meets secondary treatment requirements Contact Tank Combined or Dedicated Clarifiers PE or Raw RAS Short HRT Contact RAS Tank MLSS or RAS WAS WAS
Biological Contact Bench Scale Testing Supernatant TSS, mg/l 120 100 80 60 40 20 0 % Approach to Residual Particulate COD 100% 90% 80% 70% 60% 50% 40% 30% 410 820 1025 1230 1540 20% 1740 10% 0% Particulate COD = TCOD - SCOD(0.45 um filter) 0 5 10 15 20 25 30 Contact Time (min) 0 5 10 15 20 25 30 500 mg/l 1,000 mg/l 1,250 mg/l 1,500 mg/l 2,000 mg/l Flocculation Time, minutes Demonstration Target MLSS 1500-2000 mg/l HRT 15-20 minutes
CEPT Demonstration Full Scale ¼ existing primary settling tanks Wet weather SOR: 1500 gal/sf-d 40 mg/l ferric chloride and 0.5 mg/l anionic polymer Primary effluent sampler Influent sampler and ferric chloride feed location CES Primary Clarifiers 9-12 Polymer Feed/ Mixer Location
Biological Contact Treatment Demonstration 4000 gallon aerated plug flow reactor Bench Scale Settling Tests MLSS: 1500-2000 mg/l HRT: 15-20 minutes Bench testing for clarification Plant Influent Head Tank Tank 4 Tank 1 Tank 2 Return Sludge
Compressible Media Filter Demonstration WWETCO Rental Filtration rate 5-7.5 gpm/sf 2011 - Primary effluent and secondary effluent 2012 - Primary influent
Simulated Wet Weather Biological Contact Item Units 10/12/2011 10/17/2011 10/17/2011 Influent stream Blend of primary influent and secondary effluent MLSS mg/l 1653 1882 2069 Influent COD mg/l 190 160 130 TSS mg/l 95 79 66 BOD 5 mg/l 68 64 51 TP mg/l 1.8 1.8 1.3 Reactor 3 Contract time minutes 15 22 15 Effluent TSS mg/l 34 15 7 Reactor 4 Contact time minutes 20 29 20 Effluent COD mg/l 110 51 59 Effluent TSS mg/l 25 19 6 Effluent TP mg/l 1.0 0.53 0.36 Demonstration Target MLSS 1500-2000 mg/l HRT 15-20 minutes
Simulated Wet Weather Compressible Media 120 Total Suspended Solids, mg/l 100 80 60 40 20 60 13 19 8 34 11 58 22 5 7 100 10 26 26 26 23 12 10 15 15 15 12 31 5 27 8 0 5.5 5.5 7.5 7.5 80 RAS 5.5 135 RAS 7.5 11 Fe @ 5.5 21 Fe @ 5.5 31 Fe @ 5.5 8 Fe @ 7.5 8 Fe @ 7.5 8 Fe @ 7.5 10 Fe @ 5 7 Fe @ 7.5 Diluted Primary Effluent Filtered Effluent
Simulated Wet Weather Compressible Media 200 180 160 140 120 190 130 160 150 RAS addition did not improve soluble COD removal Ferric addition not required Test filtration rates of 5-10 gpm/sf Soluble COD, mg/l 100 80 60 40 5150 79 59 71 68 86 82 71 7170 71 65 65 65 57 59 53 55 52 77 71 95 30 20 0 5.5 5.5 7.5 7.5 80 RAS 5.5 135 RAS 7.5 11 Fe @ 5.5 21 Fe @ 5.5 31 Fe @ 5.5 8 Fe @ 7.5 8 Fe @ 7.5 8 Fe @ 7.5 10 Fe @ 5 7 Fe @ 7.5 Diluted Primary Effluent scod Filtered scod
Wet Weather Testing - May 7, 2012 325 300 275 250 225 CES and BC Flow, mgd 200 175 150 125 100 75 50 25 0 5/6/12 0:00 5/6/12 3:00 5/6/12 6:00 5/6/12 9:00 5/6/12 12:00 5/6/12 15:00 5/6/12 18:00 5/6/12 21:00 5/7/12 0:00 5/7/12 3:00 5/7/12 6:00 5/7/12 9:00 5/7/12 12:00 5/7/12 15:00 5/7/12 18:00 5/7/12 21:00 5/8/12 0:00 CMF Operation
Wet Weather Testing - TSS 380 360 340 320 300 280 260 240 220 200 180 160 140 120 100 80 60 40 20 0 6:00 7:30 9:00 10:30 12:00 13:30 15:00 16:30 18:00 19:30 21:00 22:30 0:00 Total Suspended Solids, mg/l Time BC/CES Influent BC (HRT=16 min ) BC (HRT=22 min) CMF Influent CMF Effluent CES Effluent
Wet Weather Testing BOD 70 Biochemical Oxygen Demand, mg/l 60 50 40 30 20 10 0 6:00 7:30 9:00 10:30 12:00 13:30 15:00 16:30 18:00 19:30 21:00 22:30 0:00 Time BC (HRT=16 min ) BC (HRT=22 min) CMF Influent CMF Effluent CES Effluent
Wet Weather Testing COD 200 Chemical Oxygen Demand, mg/l 180 160 140 120 100 80 60 40 20 0 6:00 7:30 9:00 10:30 12:00 13:30 15:00 16:30 18:00 19:30 21:00 22:30 0:00 Time BC/CES Influent BC (HRT=16 min ) BC (HRT=22 min) CMF Influent CMF Effluent CES Effluent
Wet Weather Testing Soluble COD Soluble Chemical Oxygen Demand, mg/l 120 110 100 90 80 70 60 50 40 30 20 10 0 6:00 7:30 9:00 10:30 12:00 13:30 15:00 16:30 18:00 19:30 21:00 22:30 0:00 Time BC/CES Influent BC (HRT=16 min ) BC (HRT=22 min) CMF Influent CMF Effluent CES Effluent
Wet Weather Testing - Ammonia 9 8 Ammonia Nitrogen, mg N/L 7 6 5 4 3 2 1 0 6:00 7:30 9:00 10:30 12:00 13:30 15:00 16:30 18:00 19:30 21:00 22:30 0:00 Time BC/CES Influent BC (HRT=16 min ) BC (HRT=22 min) CMF Influent CMF Effluent CES Effluent
Wet Weather Testing Total Phosphorus 3.0 2.5 Total Phosphorus, mg P/L 2.0 1.5 1.0 0.5 0.0 6:00 7:30 9:00 10:30 12:00 13:30 15:00 Time BC/CES Influent BC (HRT=16 min ) BC (HRT=22 min) CMF Influent CMF Effluent CES Effluent 16:30 18:00 19:30 21:00 22:30 0:00
Wet Weather Testing Soluble Phosphorus 0.8 0.7 Soluble Phosphorus, mg P/L 0.6 0.5 0.4 0.3 0.2 0.1 0.0 6:00 7:30 9:00 10:30 12:00 13:30 15:00 Time BC/CES Influent BC (HRT=16 min ) BC (HRT=22 min) CMF Influent CMF Effluent CES Effluent 16:30 18:00 19:30 21:00 22:30 0:00
Conclusion to date Biological Contact Treatment Achieved lowest effluent concentrations Met all demonstration study effluent goals MLSS: 1600 to 2000 mg/l at 15 minute HRT. Compressible Media Filtration Effluent TSS, BOD 5, TP < effluent goals at 7.5 gpm/sf. CEPT Inconclusive due to equipment malfunctions Ongoing Testing 4-5 Additional wet weather events Biological contact settling characteristics testing Disinfection testing
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