CRITICAL CRITERIA FOR EVALUATING MEMBRANES FOR WATER SOFTENING

Transcription

1 CRITICAL CRITERIA FOR EVALUATING MEMBRANES FOR WATER SOFTENING Ohio AWWA 2016 Annual Conference Peter Kube, PE September 15, 2016

2 Outline Softening Water Discuss 4 Factors when Evaluating Membranes for Softening Examine 3 Recent Case Studies Regarding These Factors

3 Soft Water

4 Typical Softening Technologies Lime Membranes (NF/RO) Membranes (Electrodialysis Reversal) Ion Exchange

5 Membrane pore sizes 1 lb = 2.73 x10^26 Daltons AWWA/ASCE, (1998) Water Treatment Plant Design, 3 rd ed,

6 Factor 1: Available Raw Water Considerations Peak vs. Average Flows Limits on Filters Raw Productivity Water of Wells Remaining Useful Life of Wells Growth of Demand FILTERS Backwash Blend MEMBRANES Concentrate Permeate Finished Water Solutions New Wells New Filters Change of Hardness?

7 Factor 2: Pre-Treatment (Groundwater) Cl 2, KMnO 4, etc. Raw Water FILTERS MEMBRANES Permeate Finished Water Typical Membrane Prep. Backwash Fe & Mn Removal Cartridge Filters Concentrate ph adjust (Acid) NaHSO 3 (eliminates Cl 2 ) Anti-Scalant

8 Factor 3: Operational Support

9 Factor 4: Concentrate Disposal: Ocean Deep Well Injection Sewer River

10 Factor 4: Concentrate Disposal: At River Waste Load Allocation (Ohio Administrative Code ) Stream Flow Outfall Discharge Characteristic Max TDS Concentration Effluent Flow at Design ADF Characteristic River s 1Q10 Flow River s 7Q10 Flow Upstream TDS Downstream TDS WQC Value 43 cfs (Great Miami River) 50 cfs (Great Miami River) TBD mg/l* 1,500 mg/l Regulated TDS Limits Characteristic Acute Aquatic Life Criteria Chronic Aquatic Life Criteria * Values to be supplied by Ohio EPA Value 4500 mg/l TBD mg/l (based on calculation)

11 Viability of Membrane Softening Fairborn, Ohio- Case Study 1 of 3

12 Viability of Membrane Softening Fairborn, Ohio- Case Study 1 of 3 Sandhill Road Water Treatment Plant Capacity: 8.4 MGD 9.1 MGD in 2050 Source: Great Miami River Buried Valley Aquifer Treatment: Chemical Oxidation - Filtration- Disinfection- Fluoride Addition Source Water Pre-Treatment Operational Support 10.6 MGD Raw Water Available Raw water Main requires expansion (2016) Add 2 Filters to achieve 2050 flows Typical Pretreatment No additional hiring predicted Concentrate Discharge To Nearby Sewer (Fairborn is the Sewer Utility)

13 Viability of Membrane Softening Warren County, Ohio- Case Study 2 of 3

14 Viability of Membrane Softening Warren County, Ohio- Case Study 2 of 3 Richard A. Renneker Water Treatment Plant Capacity: 9 MGD Source: Little Miami River Buried Valley Aquifer Treatment: Aeration - Chemical Oxidation Filtration - Disinfection - UV Treatment Fluoride Addition Source Water 15 to 17 MGD Sufficient Filtration Typical Membrane Prep. Pre-Treatment Operational Support No additional hiring predicted Concentrate Discharge Pursuing Little Miami River Discharge

15 Viability of Membrane Softening Miamisburg, Ohio- Case Study 3 of 3

16 Viability of Membrane Softening Miamisburg, Ohio- Case Study 3 of 3 Miamisburg Water Treatment Facility Capacity: Existing 5.76 MGD 6.71 MGD ult. Source: Great Miami River Buried Valley Aquifer Treatment: Chemical Oxidation Filtration- Disinfection- Fluoride Addition Source Water Pre-Treatment Operational Support 5.9 MGD Raw Water Available Will require additional well to reach Arcadis ultimate 2016 flows Sufficient Filtration Typical Membrane Prep. No additional hiring predicted Concentrate Discharge Discharging to Gr. Miami River Traded TDS with WWTP

17 Questions?

18 People who Prefer Concentrate? Blend Raw Water FILTERS MEMBRANES Permeate Finished Water Backwash?? Concentrate

19 Maple Syrup can be Concentrate Photo courtesy of OMES

20 Thank you Peter Kube, PE