G 0005 stock 2010 Template Final.ppt Efficacy and Energy Requirements for Trace Contaminant Removal in Water Reuse Systems IWA Water Reuse Conference 28 October, 2013 Windhoek, Namibia Ben Stanford, Ph.D. and Jean Debroux, Ph.D. with Shane Snyder, Dan Gerrity, and Megan Plumlee
Contaminants in CA Reuse Context CA Regulates microbes and CECs 12 10 10 rule for viruses, Giardia, and Cryptosporidium Specific log removal for CECs 0.5 log (69%) for most indicators 0.3 log (50%) for recalcitrant indicators BUT, removal is based on Full Advanced Treatment or FAT MF + RO + UV/AOP
Indirect Potable Reuse Full Available Treatment (FAT): Membrane Fouling (Contaminant Oxidation) MBR O 3
Contaminants in CA Reuse Context CA Regulates microbes and CECs 12 10 10 rule for viruses, Giardia, and Cryptosporidium Specific log removal for CECs 0.5 log (69%) for most indicators 0.3 log (50%) for recalcitrant indicators BUT, removal is based on Full Advanced Treatment or FAT MF + RO + UV/AOP Is there a non FAT option? Is it effective for CECs and pathogens? How Much Does it Cost?
Indirect Potable Reuse FAT: Non-FAT: MF O 3 BAC Recharge Advantages of O 3 -BAC Disadvantages of O 3 -BAC Source: Sundaram et al. (2009) WateReuse Research Symposium
Ozonation of Secondary/Tertiary Final Disinfection Effluents O 3 Contaminant Oxidation / Increased UV Transmittance O 3 BAC MF UV Contaminant Oxidation and Disinfection MF O 3 BAC O 3 Membrane Fouling (Contaminant Oxidation) MF O 3 UV/H 2 O 2
Trace Organic Contaminant Removal by Ozone (Pisarenko, Stanford, et al)
Indirect Potable Reuse Pilot Project Effluent
Deep Bed Filter Ozone BAC 1200 1000 800 600 400 200 30 Atrazine Carbamazepine Dilantin (Phenytoin) Fluoxetine Gemfibrozil Iopromide Naproxen n-nitrosodimethylamine Sulfamethoxazole Triclosan Concentration (ng/l) 20 Influent Post Ozone Post BAC 10 0
Indirect Potable Reuse FAT: Non-FAT: MF O 3 BAC Recharge Advantages of O 3 -BAC Nearly complete TOrC removal Eliminates concentrated brine stream Reduced energy consumption Source: Sundaram et al. (2009) WateReuse Research Symposium Disadvantages of O 3 -BAC No reduction in salinity Potential for bacterial regrowth Higher TOC in effluent NDMA formation?
How Do We Estimate TOrC/CEC Removal Costs? Oxidation efficacy at 50 MGD O 3 BAC Treatment Plant O 3 Dose 1.5 mg/l 3 mg/l 6 mg/l 9 mg/l O 3 :TOC Ratio 0.25 0.5 1.0 1.5 Average Percent Destruction of Target Compounds (CECs) Group 1 >90% >90% >90% >90% Group 2 >60% >90% >90% >90% Group 3 >30% >60% >90% >90% Group 4 >15% >30% >60% >80% Group 5 <5% >5% >15% >20%
CapEX and O&M Costs Developed for Multiple Technologies Curves developed as stand alone unit processes Ozone BAC Capital Costs ($M/MGD) 1.20 1.00 0.80 0.60 0.40 0.20 0.00 Relative Ozone Capital Costs 10 to 535 MGD 2011 Costs (ENRCCI = 9116) y = 2.011x 0.474 R² = 0.876 0 100 200 300 400 500 600 Flow (MGD) Ozone System Size Capacity Ozone Contactor Capital Cost Equipment Capital Cost Total Project Cost Capital Unit Cost lb/day MGD mil $ mil $ mil $ mil$/mgd 250 10 0.098 1.27 7.63 0.764 400 16 0.133 1.38 8.46 0.529 534 21 0.161 2.34 14.0 0.655 1020 41 0.244 1.25 8.35 0.205 1300 52 0.285 2.80 17.2 0.332 5000 200 1.002 3.50 25.2 0.126 7200 288 1.404 5.00 35.8 0.124 9750 389 1.972 7.50 52.9 0.136 13400 535 2.682 10.0 70.9 0.132
BAC costing assumptions and results Based on drinking water GAC designs Costs estimated for 10 and 20 minute Empty Bed Contact Times (EBCTs) Cost curves separated into <10 MGD and 10 MGD to develop better curve fit
Other Cost Curves Developed UV/AOP (assumes 400 mj/cm 2 and 10 mg/l peroxide dose) MF RO Capital Costs ($M/MGD) 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 y = 0.251x 0.056 R² = 0.274 0 20 40 60 80 100 Flow (MGD) O&M Costs ($M/MGD) 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 y = 0.303x 0.219 R² = 0.803 0 10 20 30 40 50 60 Flow (MGD) Capital Costs ($M/MGD) 3.0 2.5 2.0 1.5 1.0 0.5 0.0 y = 1.893x 0.223 R² = 0.962 0 20 40 60 80 100 Flow (MGD)
Combinations of Processes Flow Normalized Capital Costs Capacity (MGD) O 3 BAC Process Trains and Capital Costs ($M/MGD) MF O 3 BAC MF RO MF RO UV/AOP MF O 3 RO 1 $4.0 $5.9 $5.7 $5.9 $7.8 5 $1.8 $3.1 $4.0 $4.2 $4.9 10 $1.3 $2.4 $3.4 $3.6 $4.1 25 $0.82 $1.8 $2.8 $3.0 $3.2 50 $0.58 $1.4 $2.4 $2.6 $2.7 80 $0.46 $1.2 $2.2 $2.4 $2.4
Combinations of Processes Flow Normalized O&M Costs Capacity (MGD) Process Trains and Annual O&M Costs ($M/MGD) O 3 BAC MF O 3 BAC MF RO MF RO UV/AOP MF O 3 RO 1 $0.08 $0.38 $0.54 $0.58 $0.55 5 $0.06 $0.27 $0.51 $0.55 $0.52 10 $0.06 $0.24 $0.48 $0.51 $0.48 25 $0.06 $0.20 $0.42 $0.46 $0.43 50 $0.06 $0.18 $0.38 $0.41 $0.39 80 $0.05 $0.17 $0.36 $0.39 $0.36
(Accounts for Ozone + BAC) WateReuse Research Project 08 05, Costs for Contaminant Destruction @ 50 MGD Facility with 10 mg/l TOC (EfOM) O 3 Dose 3 mg/l Ozone 6 mg/l Ozone 12 mg/l Ozone O 3 :TOC Ratio 0.3 0.6 1.2 Capital Costs $29M $30.6M $32.2M Annual O&M $2.8M $3.1M $3.6M Group 1, % Removal >90% >90% >90% Group 2, % Removal 50 70% 70 90% >90% Group 3, % Removal ~50% ~70% >90% Group 4, % Removal 10 30% 30 50% ~70% Group 5, % Removal <10% ~10% 10 30 %
Closing Remarks What is the major driver for treatment choice selection in potable reuse applications? What water quality goals are required? Are there ways to minimize capital and O&M costs to achieve the water quality goals? Ozone + BAC may be a possible option for indirect potable reuse BAC provides additional TOrC removal Other factors should be considered Specific water chemistry Removal objectives End use of water Engineered or environmental buffers
bstanford@hazenandsawyer.com