Microconstituent and Pathogen Removal in Reclaimed Water: A Summary of Pilot Testing Results and Full Scale Costs

Transcription

1 Microconstituent and Pathogen Removal in Reclaimed Water: A Summary of Pilot Testing Results and Full Scale Costs Keith Bourgeous Ph.D., P.E & Andrew Salveson P.E. PNCWA 2009 September 15, 2009

2 This Presentation Will Discuss Results of a Full Scale Cost Comparison WateReuse Foundation Project Description 2. AOP processes 3. Pilot Testing Results Background on Microconstituents tw308wrf.ppt/2

3 Background

4 tw308wrf.ppt/4 Microconstituents Were Found in Drinking Water of At Least 41 Million Americans - March 10, 2008 Associated Press

5 Microconstituents tw308wrf.ppt/5 Potential biological impacts on wildlife Feminization of male fish or masculinization of female fish Delayed sexual development in fish Intersex of frogs Delayed metamorphosis in frogs Embryo mortality Abnormal hormone levels Impaired reproductive systems and immune systems Structural and neurological damage

6 Variety of Microconstituent Sources Antibacterial hand soap triclosan Birth control pills ethinyl estradiol Coffee caffeine Polycarbonate plastic bisphenol-a Fire extinguisher TDCPP, TCEP, TCPP Insect repellent DEET tw308wrf.ppt/6 Compounds shown represent only a small portion of all compounds analyzed.

7 Conventional Water Treatment is Often Ineffective in Removing or Destroying Microconstituents Microconstituents/EDCs/PPCPs tw308wrf.ppt/7

8 Microconstituents May Impact the Fish and the Frogs Humans Too? tw308wrf.ppt/8

9 Microconstituents tw308wrf.ppt/9 Human Effects Although adverse effects on aquatic organisms have been observed, the health impacts on humans have not been observed because the concentrations are low. A recent study conducted by Dr. Shane Snyder at Southern Nevada Water Authority has shown that the levels found in municipal wastewater effluents do not pose a health risk to humans.

10 WateReuse Foundation Project

11 WateReuse Foundation Project Funding Agencies Project Team Duke University U.S. Department of Agriculture Carollo Engineers tw308wrf.ppt/11

12 Project Objective Find and demonstrate emerging yet market ready reclaimed water treatment technologies that can robustly destroy pathogens and microconstituents at a cost below that of reverse osmosis. To demonstrate market ready technologies, the project consisted of both bench top and pilot scale studies. tw308wrf.ppt/12

13 Disclaimer The comments and views detailed herein may not necessarily reflect the views of the WateReuse Foundation, its officers, directors, employees, affiliates or agents. tw308wrf.ppt/13

14 Advanced Oxidation Processes

15 An Advance Oxidation Processes is a: Process that generates elevated concentrations of hydroxyl radicals ( OH), a strong oxidant that is capable of the complete oxidation of most organic compounds into carbon dioxide, water, and mineral acids. tw308wrf.ppt/15

16 Hydroxyl Radical ( OH) is Key Powerful oxidant Highly reactive Short-lived (~10-5 seconds) Non-selective Typically exist at very low steady-state aqueous concentrations (10-12 to M) Formed during the reaction of H 2 O 2 with various catalysts and reagents (e.g., UV, O 3, TiO 2, HOCl, Fe 2+ ) tw308wrf.ppt/16

17 Electrochemical Oxidizing Potentials Vary Widely among Treatment Chemicals tw308wrf.ppt/17 Oxidizing Agent EOP, V EOP Relative to Chlorine Hydroxyl Radical Ozone Peracetic Acid Hydrogen Peroxide Hypochlorite Chlorine Chlorine Dioxide Adapted from Wastewater Engineering Treatment and Reuse, Metcalf & Eddy (2003), peracetic acid data courtesy of Enviro-Tech Chemical Services Inc.

18 Project Structure

19 Project Consisted of Preliminary phase bench scale studies Pilot scale studies tw308wrf.ppt/19

20 Bench Top Studies Included Evaluation of The Following Chlorine Chloramine Medium pressure (MP) UV MP UV with hydrogen peroxide (H 2 O 2 ) Ozone tw308wrf.ppt/20 Ozone with H 2 O 2 PAA (peracetic acid) PAA with UV

21 Pilot Testing Sites State Utility Tech. FL FL CA NC South Cross Bayou Water Reclamation Facility Bradenton Wastewater Treatment Facility Dublin San Ramon Services District Charlotte Mecklenberg Sugar Creek WWTP LPHOUV/H 2 O 2 PAA, PAA/MPUV, & H 2 O 2 / MPUV O 3 & O 3 /H 2 O 2 LPUV/TiO 2 Equipment Supplier Trojan Aquionics Applied Process Technology Purifics tw308wrf.ppt/21

22 Microbiological Contaminants Coliform bacteria 2-3 mm MS-2 bacteriophage nm, Adenovirus tw308wrf.ppt/22

23 Microconstituents of Concern tw308wrf.ppt/23 17a-Ethynlestradiol (EE2) 17b-Estradiol (E2) 4-nonylphenol (NP) 4-octylphenol (OP) Atrazine Bisphenol-a Carbamazapine Dehydroepiandrosterone (DHEA) Dihydrotestosterone (DHT) N,N-Diethyl-3-methylbenzamide (DEET) Triclosan 2,4,6,8-who-do-weappreciate Tris (2-chloroethyl) phosphate (TCEP) N-nitrosodimethylamine (NDMA)

24 Microconstituents & Pathogen Seeding Was Used tw308wrf.ppt/24 At some project sites indigenous pathogens and microconstituent concentrations were below detection limits and system performance could not be quantified. At these locations the spiking of pilot influent with NDMA and MS2 phage occurred to document system effectiveness at removing these constituents.

25 Description & Results of Pilot Studies

26 Ozone/Hydrogen Peroxide Pilot Study in Dublin, CA tw308wrf.ppt/26

27 Filters Used in Ozone/ Hydrogen Peroxide Pilot Study tw308wrf.ppt/27

28 Results of Ozone/H Study Sand filtration did not provide a measurable pathogen barrier. MF did provide a substantial protozoan and bacterial barrier but did not provide substantial virus removal. Sand filtration and MF showed >50 percent removal of microconstituents. Substantial destruction of select microconstituents was seen at low ozone doses. tw308wrf.ppt/28

29 Results of Ozone/H Study Substantial log reduction of virus (seeded MS2 coliphage) was achieved at low ozone doses (<5 mg/l). Dose/response for seeded MS2 coliphage was not dependant upon the addition or the amount of H High ozone doses (>12 mg/l) were required to attain the regulated low total and fecal coliform counts. tw308wrf.ppt/29

30 tw308wrf.ppt/30 LPHO UV/ H Pilot Study in Pinellas County, FL

31 tw308wrf.ppt/31 Filters Used in LPHO UV/H Pilot Study

32 Results of LPHO UV/H Study tw308wrf.ppt/32 The use of roughing filters ahead of polishing filters provided a high quality reclaimed water effluent. UV alone at low UV doses (<50 mj/cm 2 ) did not result in measurable NDMA destruction. Peroxide/UV at low UV doses (<50 mj/cm 2 ) did result in measurable NDMA destruction. Peroxide/UV at high doses (>50 mj/cm 2 ) did result in substantial microconstituent destruction

33 Results of LPHO UV/H Study Substantial log reduction of viruses (seeded MS2 coliphage) was achieved at low UV doses (<50 mj/cm 2 ). The addition of peroxide did not reduce UV disinfection performance. Rapid coliform destruction was seen at low UV doses (50 mj/cm 2 ). tw308wrf.ppt/33

34 tw308wrf.ppt/34 MP UV/ H & MP UV/Peracetic Acid Pilot Studies in Bradenton, FL

35 Results of MP UV/H & MP UV/Peracetic Acid Study The sand media filter provided high quality reclaimed water Peroxide/UV at high UV doses (>50 mj/cm 2 ) did result in measurable NDMA destruction. Peroxide/UV at high UV doses did result in substantial microconstituent destruction. PAA/UV at low doses was more effective in microconstituent destruction then PAA alone. tw308wrf.ppt/35 Limited log reduction of virus (seeded coliphage) was achieved with PAA alone.

36 tw308wrf.ppt/36 Results of MP UV/H & MP UV/Peracetic Acid Study Substantial log reduction of virus was achieved at UV doses of >50 mj/cm 2. PAA/UV at low doses (<50 mj/cm 2 ) increased the log reduction of virus achieved when compared to UV only. Peroxide/UV at UV doses (>50 mj/cm 2 ) increased the log reduction of virus achieved when compared to UV only. PAA only and PAA/UV at low doses provided rapid coliform destruction. Peroxide/UV at UV doses >50 mj/cm 2 provided rapid coliform destruction.

37 TiO 2 /UV Pilot Study in Charlotte, NC Tertiary Filters Secondary Clarifier Effluent Filter Effluent Discharge UV Treatment UV/TiO 2 Pilot Unit Constituents tw308wrf.ppt/37

38 TiO 2 /UV Pilot Study in Charlotte, NC Q Influent 10 mm cartridge filter 1.7Q UV Tubes 0.7Q Aeration TiO 2 Return Slurry Stainless steel tube 3 mm Quartz sleeve UV lamp tw308wrf.ppt/38

39 TiO 2 /UV Pilot Study in Charlotte, NC Q Influent 10 micron cartridge filter 1.7Q UV Tubes Accumulator Ceramic MF membrane 0.7Q TiO 2 Return Slurry Effluent Q Aeration tw308wrf.ppt/39

40 Results of TiO 2 /UV Pilot Study tw308wrf.ppt/40 Sand filtration alone provided limited reduction of total coliform. Sand filtration with bag/cartridge filtration removed >80 percent total coliform. Sand filtration when coupled with bag/cartridge filtration provided >80 percent removal of hormonal equivalency. Extensive particle removal seen across the ceramic membrane alone. Enhanced removal occurred because of TiO 2, and further enhanced particle removal occurred due to oxidation of particulates by TiO 2 /UV

41 Results of TiO 2 /UV Pilot Study >99.9 percent removal of total coliform was seen across the ceramic membrane alone. >99.9 percent removal of total coliform was obtained with the TiO 2 /UV component of the PhotoCat prior to ceramic membrane filtration. For all test cases but one, removal of coliform to non-detect levels occurred. The ceramic membrane saw no measurable removal of seeded MS2 virus with and without TiO 2 addition. Robust disinfection of seeded MS2 (up to percent removal) was caused by the TiO 2 process. tw308wrf.ppt/41

42 Results of TiO 2 /UV Pilot Study Measurable destruction of various microconstituents was seen at low energy inputs. Substantial filtration and oxidation of the hormonal equivalency was seen, demonstrating a multiple barrier for the EEQ parameter. tw308wrf.ppt/42

43 Development of Full-Scale Cost Estimates

44 Cost Comparisons of Innovative Treatment Technologies Detailed Cost Analysis was performed for: Chlorine for Title 22 disinfection Ozone UV UV with H Titanium dioxide with UV Peracetic acid with UV tw308wrf.ppt/44

45 Cost Estimate Assumptions Innovative Treatment Technology Systems sized to obtain the following 90 percent reduction of the hormonal characteristics of the water As measured by estradiol equivalency (EEQ). Reduction of pathogens and indicator organisms to the levels specified in the California Code of Regulations, Title 22 requirements. tw308wrf.ppt/45

46 Cost Estimate Assumptions Continued Each design is new construction No demolition of existing equipment required All building/structures are at grade tw308wrf.ppt/46 The following operational criteria are assumed Design flow 10 mgd Average flow 5 mgd Energy cost $0.10/kilowatts per hour (kw-hr) Labor rate $50/hr Pumping costs are not included Disinfection systems sized for disinfection following sand filtration

47 Innovative Treatment Technology Costs Innovative Treatment Technology costs were compared to the cost of microfiltration (MF)/Low pressure Reverse Osmosis (RO)/Medium pressure UV Hydrogen Peroxide system MF/RO/UV-H 2 O 2 costs were planning level costs completed by Carollo in May 2006 for the Southwest Florida Water Management District tw308wrf.ppt/47

48 System Characteristics Treatment Sodium Hypochlorite Channel or Trains Total Lamps Dose 4 N/A 10 mg/l Peroxide/MP UV 2/4 NA/ mg/l-100 mj/cm 2 PAA/MP UV 2/4 NA/144 8 mg/l-100 mj/cm 2 Ozone 2 NA 9 mg/l Ozone/MP UV 2 NA/72 4 mg/l-100 mj/cm 2 TiO 2 /UV 7 NA 264 kw/mgd tw308wrf.ppt/48

49 System Size and Power Draw tw308wrf.ppt/49 Treatment System footprint Power Draw (kw) Sodium Hypochlorite CCB: 173 x 84 Chemical Feed: 29 x 29 Peroxide/MP UV H 2 O 2 : 45 x 28 UV Equipment: 27 x 13 Electrical Bldg: 20 x 20 PAA/MP UV H 2 O 2 : 69 x 20 UV Equipment: 27 x 13 Electrical Bldg : 20 x Ozone 160 x Ozone/MP UV O 3 : 75 x 60 UV Equipment: 15 x 13 Electrical Bldg : 12 x TiO 2 /UV 72 x

50 System Cost Summary Treatment Sodium Hypochlorite Annual Energy Cost Annual O&M Cost Project Cost Life Cycle Cost $12,000 $219,000 $7,532,000 $10,044,000 Peroxide/MP $208,000 $509,000 $8,923,000 $14,762,000 UV PAA/MP UV $207,000 $1,645,000 $9,563,000 $28,427,000 Ozone $91,000 $276,000 $9,094,000 $12,260,000 Ozone/MP UV $191,000 $330,000 $9,020,000 $12,806,000 TiO 2 /UV $49,000 $529,000 $47,942,000 $54,010,000 tw308wrf.ppt/50

51 System Cost Summary Treatment Sodium Hypochlorite Annual O&M Cost Project Cost Life Cycle Cost $219,000 $7,532,000 $10,044,000 Ozone $276,000 $9,094,000 $12,260,000 MF/RO- $2,470,000 $45,601,000 $73,931,900 Peroxide/MP UV tw308wrf.ppt/51

52 Summary

53 Summary Several different innovative technologies were found to be effective at microconstituent and pathogen removal. Ozone was found to be the most cost effective treatment. The use of ozone or other innovative treatment technologies were found to have much lower life cycle costs then MF/RO/AOP. tw308wrf.ppt/53

54 Acknowledgements tw308wrf.ppt/54 WateReuse Foundation Southwest Florida Water Management District Duke University U.S. Department of Agriculture Southern Nevada Water Authority Numerous utilities: Cities of Largo, Bradenton, and Tampa and Pinellas and Manatee Counties in Florida Dublin San Ramon Service District in California Charlotte Mecklenburg Utilities in North Carolina Tavy Wade, Andrew Salveson, Shrubra Jain, Vinnie Hart, and Christopher Crotwell of Carollo

55 Questions? tw308wrf.ppt/55 Ethyl estradiol MS2 Adenovirus