Mike Nixon, E.I. Phil Locke, P.E.

Transcription

1 First-of-It s Kind Industrial Ion Exchange Process Brings Municipal Potable Water Treatment Facility into Full Regulatory Compliance Mike Nixon, E.I. Phil Locke, P.E.

2 Agenda Background Treatment Alternatives Treatment Process and Design Startup and Testing Lessons Learned Project Benefits

3 Acknowledgements City of Bunnell Water Treatment Plant Ion Exchange Project City of Bunnell Fernand Tib Tiblier, Jr. Ron Cook Jason Palmer JEA Ryan Popko Bill Green Orica (IOXM) Water Care Ion Exchange System OEM Scott Mitchell

4 Background Bunnell City of Bunnell, Florida 1.0 MGD Water Treatment Plant Source - Floridan Aquifer Cascade Aeration Dual Media Filtration Disinfection Chloramines Finished Water Storage

5 City of Bunnell Population ~2,900 2 nd largest city in Florida (by area) Water age compounds water quality issues

6 FDEP Consent Order Issued October 2011 Maximum Contaminant Level (MCL) exceeded for Disinfection Byproducts (DBPs) Total Trihalomethanes (TTHMs) 120 ug/l average; 80 ug/l limit Schedule

7 Water Customer Concerns No suds zone Taste & odor Color Appliance damage

8 Project Goals and Initial Screening Reduce TTHMs Reduce Hardness Screening Evaluation Membrane Separation Lime Softening Ion Exchange

9 Initial Screening Evaluation Ion Exchange/Organix Membrane Softening Cation Exchange

10 Membrane Treatment Pros Consistent removal of DBP precursors & hardness Highly effective and reliable Cons Concentrate management limited disposal options Additional source water supply needed Cost prohibitive Consent Order timeline likely not met

11 Lime Softening Pros Excellent hardness removal Efficient Cons O&M client s poor previous experience Limited dissolved organic carbon removal Requires additional treatment (e.g., anion exchange) for effective organics removal

12 Ion Exchange Pros Dual Media Configuration Anion exchange to remove DBP precursors Cation exchange to remove hardness Small waste volume Consent Order schedule can be met Cons Regeneration brine waste disposal Increased sodium & chlorides in finished water

13 TTHM Treatment Options Matrix Primary Criteria Weight Score Technology Lime Softening Ion Exchange RO/NF Weighted Score Score Weighted Score Score Weighted Score Cost Capital Costs 15.0% O&M Costs 15.0% Technical Feasibility Finished Water Quality 20.0% Disinfection Demand 5.0% Proven Implementation 5.0% Water Loss 3.0% Treatment Waste 2.0% Footprint 1.0% Operation & Maintenance Safety 5.0% Operator Training 4.0% Maintenance 5.0% Schedule Consent Order Deadline 15.0% Permitting 5.0% Total 100.0% *Score 1-5, with 5 best

14 Pilot Test 5-10 gpm 4-8 minute resin contact time 600 bed volumes for optimal treatment 80% DOC reduction 90% reduction in true color 50% hardness removal TTHM reduced from ~120 ug/l to ~ 20 ug/l

15 WTP Process Flow Diagram

16 MIEX Process Flow Diagram Brine Tank Waste Brine

17 Historical TTHM Data Sample TTHM EPA MCL Sample TTHM EPA MCL Sample TTHM EPA MCL Date ug/l ug/l Date ug/l ug/l Date ug/l ug/l 01/ / / / / / / / / / / / / / / / / / / / / / / / / / / / / / *Highlighted cells indicate exceedance of EPA maximum contamination limit (80 ug/l)

18 Source Water Quality Parameter Well #3 Well #4 Well #5 Well #7 Well #8 ph DOC (mg/l) UV254 (cm -1 ) True Color (CU) Apparent Color (CU) H 2 S (µg/l) Turbidity (NTU) Iron (mg/l) Sulfate (mg/l) Hardness (mg CaCO 3 /L) Calcium Hardness (mg CaCO 3 /L) Sodium (mg/l) Chloride (mg/l) Conductivity (µmhos/cm) *Data from Pilot Study - February to March, 2012.

19 Design Considerations Site constraints Maintain operations Sole source OEM Performance guarantees Funding requirements

20 Ion Exchange System MICo Co-removal system Anionic resin for DOC removal Cationic resin for softening 1 st ever full-scale installation

21 Startup & Testing Equipment Startup Process startup Alarm simulations Training and water quality testing 14-day performance test

22 Water Quality Results Summary

23 DOC Levels and Removal

24 UV 254 Removal 0.033

25 DOC versus UV 254

26 Hardness Comparison

27 Cyclical Hardness Removal

28 Filtered Water Turbidity 2 NTU 1 NTU

29 Lessons Learned Use SCADA for startup data and MORs Anticipate some resin carryover Include provisions for chorine injection upstream of filters Make sure turbidimeter source has enough pressure

30 Project Benefits Achieved DBP compliance Reduced hardness Minimized footprint using coremoval ion exchange Met schedule goal & was funded 50% from USDA Residents are happy!!

31 Questions Contact Information: Mike Nixon, EI Phil Locke, PE