Pilot-Scale Evaluation of Treatment Trains for Direct Potable Reuse

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

Overview of WRRF 11-02 Title: Equivalency of Advanced Treatment Trains for Potable Reuse Main goals: Develop direct potable reuse (DPR) public health criteria Evaluate potential DPR trains

WRRF 11-02 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

WRRF 11-02 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

DPR Public Health Criteria WRRF Report 11-02-1: 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)

WRRF 11-02 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

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 )

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 )

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 )

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

MICROBIAL CRITERIA

Expected Microbial Log Removal Log Removal Unit Process Viruses Cryptosporidium Total Coliform Bacteria CAS 1 0 2 MF 0 4 4 UF 1 4 4 RO 2 2 2 BAC 0 0 0 O 3 6 1 4 UV Photolysis 6 6 6 UV/H 2 O 2 6 6 6 Cl 2 6 0 4

Expected Microbial Log Removal Treatment Train Viruses Log Removal Cryptosporidium Total Coliform Bacteria CAS- MF- RO- UV/H 2 O 2 - Cl 2 15 12 18 CAS- O 3 - MF- RO- UV/H 2 O 2 15 13 18 CAS- UF- O 3 - BAC- UV 14 11 16 CAS- O 3 - BAC- UF- UV 14 11 16 CAS- MF- O 3 - BAC- UV 13 11 16 CAS- O 3 - BAC- MF- UV 13 11 16 Expert Panel Criteria Viruses: 12 log Cryptosporidium: 10 log Total coliform bacteria: 9 log

PFOS Bisphenol A Carbamazepine Caffeine NDMA Triclosan PFOA CHEMICAL CRITERIA

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

DPR PILOT PLANT

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

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

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

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

Phase 3 TesKng (3 months)

PILOT PLANT DATA

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

PFOS Bisphenol A Carbamazepine Caffeine NDMA Triclosan PFOA CHEMICAL CRITERIA NDMA

NDMA Data Train 1

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

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

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

PFOS Bisphenol A Carbamazepine Caffeine NDMA Triclosan PFOA CHEMICAL CRITERIA BROMATE

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

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

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

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

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 4,000 292 < 6 < 3 Carbamezapine 10,000 194 21 < 4 DEET 200,000 45 < 38 < 19 Estrone 320 < 32 < 39 < 26 Meprobamate 200,000 380 170 < 8 PFOA 400 12 22 < 9 PFOS 200 < 20 < 9 < 9 Primidone 10,000 4,100 186 75 Sucralose 150,000,000 24,800 21,700 < 87 TCEP 5,000 < 95 < 92 < 90 Triclosan 2,100,000 128 9 < 9

MICROBIAL CRITERIA

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

Estimated Ozone Ct for Cryptosporidium Inactivation

Total Coliform Data Log Removal Value Sample Ozone Ozone Month MF UF (Wedeco) (H 2 O Eng) Sep 3.0 3.1 Oct 4.7* 4.7* Nov 4.1* 3.7 Dec 2.9 2.8 Jan 2.6 2.5 Feb 2.5 1.6 Mar 3.3 Apr 4.1* Jun 2.1 * Max LRV for that sample

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

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

Compliance with Microbial Criteria Log Removal Value Treatment Train* Virus Crypto Total Coliform MF-RO-UV/H 2 O 2 -Cl 2 14.3 11.7 17.7 O 3 -MF-RO-UV/H 2 O 2 14.8 10.8 16.0 UF-O 3 -BAC-UV 14.0 9.8 13.9 O 3 -BAC-UF-UV 14.0 10.8 14.5 MF-O 3 -BAC-UV 13.0 10.1 14.2 O 3 -BAC-MF-UV 13.0 9.9 14.0 Expert Panel Criteria 12 10 9 *All treatment trains included conventional activated sludge as first step

PROCESS OPERATIONS

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

UF Performance Secondary Effluent

UF Performance Secondary Effluent O 3 -BAC Effluent

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

Acknowledgements WRRF 11-02

Acknowledgements

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