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CRITICAL CRITERIA FOR EVALUATING MEMBRANES FOR WATER SOFTENINGOhio AWWA 2016 Annual ConferencePeter Kube, PE
September 15, 2016
© Arcadis 2016
OutlineSoftening Water
Discuss 4 Factors when Evaluating Membranes for Softening
Examine 3 Recent Case Studies Regarding These Factors
Ohio Section AWWA Conference | September 15, 2016
© Arcadis 2016
Typical Softening Technologies
Lime Membranes (NF/RO)
Membranes (Electrodialysis Reversal) Ion Exchange
Ohio Section AWWA Conference | September 15, 2016
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Membrane pore sizes
Ohio Section AWWA Conference | September 15, 2016
1 lb = 2.73 x10^26 Daltons
AWWA/ASCE, (1998) Water Treatment Plant Design, 3rd ed,
© Arcadis 2016
MEM
BRAN
ES
FILT
ERS
BackwashConcentrate
Finished Water
Blend
Raw Water Permeate
Considerations• Peak vs.
Average Flows
• Limits on Filters
• Productivity of Wells
• Remaining Useful Life of Wells
• Growth of Demand
Factor 1: Available Raw Water
Solutions• New Wells• New Filters• Change of
Hardness?Ohio Section AWWA Conference | September 15, 2016
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BackwashFe & Mn Removal
MEM
BRAN
ESConcentrate
FILT
ERS Finished
WaterRaw Water Permeate
Factor 2: Pre-Treatment (Groundwater)Cl2, KMnO4, etc.
•pH adjust (Acid)•NaHSO3(eliminates Cl2)
•Anti-Scalant
CartridgeFilters“Typical
Membrane Prep.“
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Ocean
Deep Well Injection
Sewer
River
Factor 4: Concentrate Disposal:
Ohio Section AWWA Conference | September 15, 2016
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Outfall
StreamFlow
Factor 4: Concentrate Disposal:At River
CharacteristicMax TDS ConcentrationEffluent Flow at Design ADF
Characteristic ValueRiver’s 1Q10 Flow 43 cfs
(Great Miami River)
River’s 7Q10 Flow 50 cfs (Great Miami River)
Upstream TDS TBD mg/L*
Downstream TDS WQC 1,500 mg/L
Discharge
Waste Load Allocation(Ohio Administrative Code 3745-2-05.)
Characteristic ValueAcute Aquatic Life Criteria
4500 mg/L
Chronic Aquatic Life Criteria
TBD mg/L (based on calculation)
Regulated TDS Limits
* Values to be supplied by Ohio EPAOhio Section AWWA Conference | September 15, 2016
© Arcadis 2016
Viability of Membrane SofteningFairborn, Ohio- Case Study 1 of 3
Ohio Section AWWA Conference | September 15, 2016
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Viability of Membrane SofteningFairborn, Ohio- Case Study 1 of 3Sandhill 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
10.6 MGD Raw Water AvailableRaw water Main requires expansion (2016)
Add 2 Filters to achieve 2050 flowsTypical Pre-treatment
Source Water Pre-Treatment Operational Support
To Nearby Sewer(Fairborn is the Sewer Utility)
Concentrate Discharge
No additional hiring predicted
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Viability of Membrane SofteningWarren County, Ohio- Case Study 2 of 3
Ohio Section AWWA Conference | September 15, 2016
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Viability of Membrane SofteningWarren County, Ohio- Case Study 2 of 3Richard A. Renneker Water Treatment Plant
Capacity: 9 MGD
Source: Little Miami River Buried Valley AquiferTreatment: Aeration - Chemical Oxidation
Filtration - Disinfection - UV Treatment –Fluoride Addition
15 to 17 MGD Sufficient FiltrationTypical Membrane Prep.
Source Water Pre-Treatment
No additional hiring predicted
Operational Support
Pursuing Little Miami River Discharge
Concentrate Discharge
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Viability of Membrane SofteningMiamisburg, Ohio- Case Study 3 of 3
Ohio Section AWWA Conference | September 15, 2016
© Arcadis 2016
Viability of Membrane SofteningMiamisburg, Ohio- Case Study 3 of 3Miamisburg Water Treatment FacilityCapacity: Existing 5.76 MGD6.71 MGD ult.Source: Great Miami River
Buried Valley AquiferTreatment: Chemical Oxidation –
Filtration- Disinfection-Fluoride Addition
5.9 MGD Raw Water AvailableWill require additional well to reach ultimate flows
Source Water Pre-Treatment Operational Support
Discharging to Gr. Miami RiverTraded TDS with WWTP
Concentrate Discharge
No additional hiring predicted
Sufficient Filtration
Typical Membrane Prep.
© Arcadis 2016
MEM
BRAN
ES
FILT
ERS
BackwashConcentrate
Finished Water
Blend
Raw Water Permeate
People who Prefer Concentrate?
??
Ohio Section AWWA Conference | September 15, 2016