Pilot-Scale Evaluation of Treatment Trains for Direct Potable Reuse

Transcription

1 Pilot-Scale Evaluation of Treatment Trains for Direct Potable Reuse Fredrick W. Gerringer, D.Env., P.E., BCEE Brian Pecson, Ph.D., P.E. Teresa Venezia Shane Trussell Ph.D., P.E., BCEE Rhodes Trussell Ph.D., P.E., BCEE

2 Overview of WRRF Title: Equivalency of Advanced Treatment Trains for Potable Reuse Main goals: Develop direct potable reuse (DPR) public health criteria Evaluate potential DPR trains

3 WRRF Research Questions Question 1: What criteria should be used to judge the equivalency of potable reuse trains? Advanced Water Treatment Facility Direct potable reuse Engineered buffer WTP or Distribution System Environmental buffer (aquifer or reservoir) Indirect potable reuse

4 WRRF Research Questions Question 1: What criteria should be used to judge the equivalency of potable reuse trains? Started with California Division of Drinking Water indirect potable reuse regulations Expert panel and workshop facilitated by the National Water Research Institute

5 DPR Public Health Criteria WRRF Report : Examining the Criteria for Direct Potable Reuse Microbial criteria 12-log virus removal 10-log Cryptosporidium removal 9-log total coliform removal Chemical criteria Satisfy all drinking water regulations Trace organic chemicals (TOrCs)

6 WRRF Research Questions Question 1: What criteria should be used to judge the equivalency of potable reuse trains? Question 2: What treatment trains are capable of meeting these criteria? Toolbox (Carollo Engineers) Pilot- and bench-scale testing of treatment trains

7 WRRF Research Questions Question 1: What criteria should be used to judge the equivalency of potable reuse trains? Question 2: What treatment trains are capable of meeting these criteria? Toolbox (Carollo Engineers) Pilot- and bench-scale testing of treatment trains

8 DPR Unit Processes Conventional activated sludge (CAS) Filtration Biological activated carbon (BAC) Microfiltration (MF) Ultrafiltration (UF) Reverse osmosis (RO) Oxidation/Disinfection Ozonation (O 3 ) Ultraviolet (UV) photolysis UV with hydrogen peroxide (UV/H 2 O 2 ) Free chlorine (Cl 2 )

9 DPR Unit Processes Conventional activated sludge (CAS) Filtration Full-scale Biological activated carbon (BAC) Microfiltration (MF) Ultrafiltration (UF) Reverse osmosis (RO) Oxidation/Disinfection Ozonation (O 3 ) Ultraviolet (UV) photolysis UV with hydrogen peroxide (UV/H 2 O 2 ) Free chlorine (Cl 2 )

10 DPR Unit Processes Conventional activated sludge (CAS) Filtration Biological activated carbon (BAC) Microfiltration (MF) Ultrafiltration (UF) Reverse osmosis (RO) Pilot-scale Full-scale Oxidation/Disinfection Ozonation (O 3 ) Ultraviolet (UV) photolysis UV with hydrogen peroxide (UV/H 2 O 2 ) Free chlorine (Cl 2 )

11 Filtration DPR Unit Processes Conventional activated sludge (CAS) Full-scale Biological activated carbon (BAC) Microfiltration (MF) Oxidation/Disinfection Ozonation (O 3 ) Ultraviolet (UV) photolysis Ultrafiltration (UF) Reverse osmosis (RO) UV with hydrogen peroxide (UV/H 2 O 2 ) Pilot-scale Free chlorine (Cl 2 ) Bench-scale

12 MICROBIAL CRITERIA

13 Expected Microbial Log Removal Log Removal Unit Process Viruses Cryptosporidium Total Coliform Bacteria CAS MF UF RO BAC O UV Photolysis UV/H 2 O Cl

14 Expected Microbial Log Removal Log Removal Unit Process Viruses Cryptosporidium Total Coliform Bacteria CAS MF UF RO BAC O UV Photolysis UV/H 2 O Cl

15 Expected Microbial Log Removal Treatment Train Viruses Log Removal Cryptosporidium Total Coliform Bacteria CAS- MF- RO- UV/H 2 O 2 - Cl CAS- O 3 - MF- RO- UV/H 2 O CAS- UF- O 3 - BAC- UV CAS- O 3 - BAC- UF- UV CAS- MF- O 3 - BAC- UV CAS- O 3 - BAC- MF- UV Expert Panel Criteria Viruses: 12 log Cryptosporidium: 10 log Total coliform bacteria: 9 log

16 PFOS Bisphenol A Carbamazepine Caffeine NDMA Triclosan PFOA CHEMICAL CRITERIA

17 Chemical Criteria Disinfection byproducts NDMA 10 ng/l Bromate 10 µg/l THMs 80 µg/l HAAs 60 µg/l Chlorate 800 µg/l Trace organic chemicals (TOrCs) 1,4-dioxane 1 µg/l Carbamazepine 10 µg/l DEET 200 µg/l Estrone 0.32 µg/l PFOA 0.4 µg/l TCEP 5 µg/l

18 DPR PILOT PLANT

19 San Jose Creek Water Reclamation Plant Whittier, CA Los Angeles County Sanitation Districts Treatment (Title 22) Nitrification/denitrification Filtration Chlorine disinfection Pilot plant source water Secondary effluent before chlorination

20 DPR Pilot Equipment LACSD RO! WEDECO Ozone Leopold BAC GE UF Econity MF! H2O Engineering Ozone

21 Phase 1 TesKng (3 months) Expert Panel Criteria Virus: 12 log Crypto: 10 log Bacteria: 9 log

22 Phase 2 TesKng (3 months) Expert Panel Criteria Virus: 12 log Crypto: 10 log Bacteria: 9 log

23 Phase 3 TesKng (3 months)

24 PILOT PLANT DATA

25 Pilot Plant Data Chemical criteria NDMA Bromate TOrCs Microbial criteria Total coliform Virus Compliance summary Operations data NDMA Carbamazepine PFOA

26 PFOS Bisphenol A Carbamazepine Caffeine NDMA Triclosan PFOA CHEMICAL CRITERIA NDMA

27 NDMA Data Train 1

28 NDMA Data Train 2 Phase 1 (MF-RO) Phase 2 (O 3 -MF-RO)

29 Phase 1 NDMA Removal by UV/H 2 O 2 and UV Photolysis (98.4% UVT) (88.9% UVT) H 2 O 2 dose = 5 mg/l

30 Phase 1 NDMA Removal by UV/H 2 O 2 and UV Photolysis (98.4% UVT) (88.9% UVT) NL = 10 ng/l H 2 O 2 dose = 5 mg/l

31 PFOS Bisphenol A Carbamazepine Caffeine NDMA Triclosan PFOA CHEMICAL CRITERIA BROMATE

32 Bromate Data Train 1 Phase 1 (UF-O 3 -BAC) Phase 2 (O 3 -BAC-UF) Avg Br - = 116 µg/l Avg Br - = 98 µg/l

33 Bromate Data Train 1 Phase 1 (UF-O 3 -BAC) Phase 2 (O 3 -BAC-UF) Phase 3 (MF-O 3 -BAC) Avg Br - = 116 µg/l Avg Br - = 98 µg/l Avg Br - = 99 µg/l

34 Bromate Formation Control by H 2 O 2 Transferred Ozone Dose ~ 4 mg/l

35 PFOS Bisphenol A Carbamazepine Caffeine NDMA Triclosan PFOA CHEMICAL CRITERIA TRACE ORGANIC CHEMICALS

36 TOrC Data Phase 1 ConcentraKon (ng/l) Public Health Secondary UF- O 3 - BAC- UV MF- RO- UV/H 2 O 2 Sample Criteria Effluent (Train 1) (Train 2) Atenolol 4, < 6 < 3 Carbamezapine 10, < 4 DEET 200, < 38 < 19 Estrone 320 < 32 < 39 < 26 Meprobamate 200, < 8 PFOA < 9 PFOS 200 < 20 < 9 < 9 Primidone 10,000 4, Sucralose 150,000,000 24,800 21,700 < 87 TCEP 5,000 < 95 < 92 < 90 Triclosan 2,100, < 9

37 TOrC Data Phase 1 ConcentraKon (ng/l) Public Health Secondary UF- O 3 - BAC- UV MF- RO- UV/H 2 O 2 Sample Criteria Effluent (Train 1) (Train 2) Atenolol 4, < 6 < 3 Carbamezapine 10, < 4 DEET 200, < 38 < 19 Estrone 320 < 32 < 39 < 26 Meprobamate 200, < 8 PFOA < 9 PFOS 200 < 20 < 9 < 9 Primidone 10,000 4, Sucralose 150,000,000 24,800 21,700 < 87 TCEP 5,000 < 95 < 92 < 90 Triclosan 2,100, < 9

38 MICROBIAL CRITERIA

39 MS-2 Disinfection Bench-scale UV photolysis UV/H 2 O > 6 log removal at 500 mj/cm 2 2 Cl 2 è 5.5 log removal at Ct of 15 min-mg/l Pilot-scale (ozone only) MS-2 spiking showed > 6 log removal Ct values were about 1.0 min-mg/l

40 Estimated Ozone Ct for Cryptosporidium Inactivation

41 Estimated Ozone Ct for Cryptosporidium Inactivation

42 Total Coliform Data Log Removal Value Sample Ozone Ozone Month MF UF (Wedeco) (H 2 O Eng) Sep Oct 4.7* 4.7* Nov 4.1* 3.7 Dec Jan Feb Mar 3.3 Apr 4.1* Jun 2.1 * Max LRV for that sample

43 PFOS Bisphenol A Carbamazepine Caffeine NDMA Triclosan PFOA SUMMARY OF COMPLIANCE WITH DPR CRITERIA

44 Compliance with Chemical Criteria Treatment Train* NDMA (10 ng/l) Bromate (10 µg/l) TOrC Chlorine DBPs MF-RO-UV/H 2 O 2 -Cl 2 N/A O 3 -MF-RO-UV/H 2 O 2 X N/A UF-O3-BAC-UV X N/A O3-BAC-UF-UV X N/A MF-O3-BAC-UV N/A O3-BAC-MF-UV No data N/A *All treatment trains included conventional activated sludge as first step

45 Compliance with Microbial Criteria Log Removal Value Treatment Train* Virus Crypto Total Coliform MF-RO-UV/H 2 O 2 -Cl O 3 -MF-RO-UV/H 2 O UF-O 3 -BAC-UV O 3 -BAC-UF-UV MF-O 3 -BAC-UV O 3 -BAC-MF-UV Expert Panel Criteria *All treatment trains included conventional activated sludge as first step

46 PROCESS OPERATIONS

47 Process Operations Effect of unit process order UF before and after O 3 /BAC

48 UF Performance Secondary Effluent

49 UF Performance Secondary Effluent O 3 -BAC Effluent

50 UF Performance Secondary Effluent O 3 -BAC Effluent

51 Chemical criteria Conclusions BAC provides good TOC and NDMA removal Consider bromate formation for train w/o RO TOrC limits met by secondary effluent Microbial criteria Total coliform removal for O 3 MS2 removal Order of unit processes can affect performance

52 Acknowledgements WRRF 11-02

53 Acknowledgements

54 Acknowledgements

55 finito