A3: Contaminant Reduction, Life Cycle Impacts, and Life Cycle Costs of Ion Exchange Treatment and Regeneration

Transcription

1 A3: Contaminant Reduction, Life Cycle Impacts, and Life Cycle Costs of Ion Exchange Treatment and Regeneration Treavor Boyer and Alysse Ness, University of Florida Jane Zhang, University of South Florida

2 Introduction Brief Description: Create a more sustainable approach to ion exchange treatment and regeneration through the coupling of: Ion exchange pilot plant study, Ion exchange process models, Life cycle assessment (LCA), Life cycle cost analysis (LCCA), and Integrated decision-support tool. Anticipated target utility characteristics: All utilities could benefit. Emphasis on small systems that treat groundwater or surface water high in DOC, bromide, nitrate, and/or hardness. Continuum of technology development:

3 Innovative Ion Exchange DOC Bromide Nitrate Hardness Ba, Sr IX and Combined IX Contaminantfree NaCl v. non-nacl Regeneration Disposal

4 Pilot Plant Study Cedar Key Water & Sewer District, Cedar Key, FL Serves approx. 900 customers Pilot plant operation 2 3 days/week, 6 8 hours/day Ion exchange operation 3 service regeneration cycles NaCl vs. NaHCO 3 regeneration Analysis On-site: UVA254, total hardness, temperature, conductivity, Fe UF: DOC, inorganic anions and cations

5 Cedar Key Groundwater Average water quality TOC 6 mg C/L Conductivity 505 µs/cm UVA /cm ph 7.4 SUVA 3.0 L/(mg C-m) Iron 1 mg/l Hardness 240 mg/l as CaCO 3 January February 2016

6 Ion Exchange Pilot Plant Cedar Key Groundwater 2A - NaCl 2B NaHCO 3 Sample Locations: Raw water, Column 2A Effluent, Column 2B Effluent, CK Tap Treated Water

7 Sampling Sample Locations: 1. Column Influent 2. Column 2A Effluent 3. Column 2B Effluent 4. Cedar Key Tap Water

8 Test Plan Test Water Contaminants Resin [NaHCO3] [NaCl] Breakthrough Regen % % [BV] QA/ Cedar Key QC GW UVA254, DOC A-30 MP - 16 UVA254 removal < 90% Cedar Key GW Cedar Key GW Cedar Key GW Cedar Key GW UVA254, DOC UVA254, DOC 5 CK + NaBr UVA254, DOC, Br A-30 MP A-72 MP Equiv Equiv. UVA254 removal < 90% 5 UVA254 removal < 90% 5 UVA254, DOC TBD 8 16 UVA254 removal < 80% 5 UVA254, DOC TBD 8 16 UVA254 removal < 90% A-30 MP A-72 MP 8 16 UVA254, Br- removal < 90%

9 Service Cycle Column Description Inner Diameter 4 in Resin Bed Depth 28 in Resin Bed Volume 352 in gal 5.8 L Service Cycle Service Flow Rate 0.4 gpm L/m Operational Mode Co-current EBCT 3.8 min BV/hr 16 BV/h Flow Rate 4.6 gpm/ft 2

10 0.25 Test 0: UV 254 Cycle #1 Cycle #2 Cycle #3 0.2 UV 254 (1/cm) BV Treated Col Inf 2A Effleunt 2B Effluent CK Tap

11 9 8 Cycle #1 Test 0: DOC Cycle #2 Cycle #3 7 6 DOC (mg/l) BV Treated Column Inf 2A Effleunt 2B Effluent CK Tap

12 4 3.5 Test 0: SUVA Cycle #1 Cycle #2 Cycle #3 3 SUVA (L/mg-m) BV Treated Col Inf 2A Effluent 2B Effluent CK Tap

13 2.5 Test 0: Iron Cycle #1 Cycle #2 Cycle #3 2 Iron (mg/l) BV Treated Col Inf 2A Effluent 2B Effluent CK Tap

14 800 Test 0: Conductivity Cycle #1 Cycle #2 Cycle #3 700 Conductivity (us/cm) BV Treated Col Inf 2A Effluent 2B Effluent

15 10 Test 0: ph Cycle #1 Cycle #2 Cycle # ph BV Treated Col Inf 2B Effluent 2A Effluent

16 Regeneration Cycle Operational Mode Regen Flow Rate Regen EBCT Regeneration Co-current Regen BVs 5 Regen Total Time Regen Total Volume Regen 2A - NaHCO 3 Regen 2B - NaCl 0.2 gpm L/m 7.6 min 39 min 29.5 L Sample: 3 samples/regeneration, 1 composite sample, 1 rinse sample Efficiency calculations based off of composite sample Rinse Cycle Rinse Flow Rate 0.4 gpm Operational Mode Co-current Rinse EBCT 3.8 min Rinse BVs 5 Rinse Total Time 19 min Backwash Backwash Flow Rate 0.4 gpm Operational Mode Countercurrent Backwash Total Time 10 min Backwash Total Volume 4.2 gal Backwash Volume 2.76 BV

17 Regeneration Results Test 0: Regeneration Efficiency DOC On DOC Off Regen Eff DOC Remaining g g % g Cycle 1 Col 2A Col 2B Cycle 2 Col 2A Col 2B Cycle 3 Col 2A Col 2B

18 Modeling Framework

19 Modeling Framework: Fixed Bed Configuration Zhang et al Wat. Res.

20 Modeling Framework: Completely Mixed Flow Reactor Bicarbonate-form anion exchange 2.2 mg/l DOC Chloride-form anion exchange 1.7 mg/l DOC

21 LCA and LCCA: Regeneration Chemicals Maul et al Chemical Engineering J.

22 LCA and LCCA: Reactor Configuration Amini et al J. of Cleaner Production

23 Integrated Decision Model

24 Example: Development of Energy Aquaculture Sustainability tool

25 Integration of Process Model with LCA/LCCA

26 Outputs and Outreach Completed: Innovative Ion Exchange and Life Cycle Impacts for Small Water Systems, Story in WaterOperators.org, Winter 2015/2016 Scheduled: Combined Ion Exchange in FL, Small Systems course, U Colorado Boulder, Spring Innovative Ion Exchange and Regeneration, US EPA Small Systems webinar series, Fall 2016 Anticipated: Poster or talk entitled, Pilot-Scale Evaluation of Bicarbonate-Form Anion Exchange at AWWA WQTC, Fall 2016 Manuscripts for submission to peer-reviewed journal, Spring 2017

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