Development of Alternative Water Supplies Water Reuse and - PowerPoint PPT Presentation

NMSU College of Engineering Dean’s Advisory Council February 23, 2018 Development of Alternative Water Supplies – Water Reuse and Desalination Pei Xu, PhD Associate Professor, Civil Engineering

Development of Alternative Water Supplies is Crucial for Water Security Elevated Salinity High sodium adsorption ratio Water Conservation Contaminants of Water Reuse Water Scarcity emerging concerns Desalination Concentrate

Challenges of Alternative Water Supplies  Water quality concerns  Intensive energy use  Concentrate and waste management Need Innovative Approaches Short-term solutions: Long-term solutions: Modify and optimize current Develop next generation technologies of technologies

Research Areas NMED BoR DOE NSF Sustainable Water and Wastewater NMWRRI Systems for - Wastewater treatment and reuse Industry - Membrane processes & desalination /Water - Water and energy Utilities - Resources recovery

Funding and Research Group  $3M funding since 2013, averaging $0.5M per year  Current research group  2 full-time postdocs  1 senior researcher  4 PhD students  3 Master graduate students  Undergraduate students  Peer-reviewed journal publications: 5 to 8 per year

From Fundamental Laboratory Study to Field Demonstration Testing

Highlights of Research Projects  Selective electrodialysis for non-potable water use, e.g., irrigation and thermal power plant cooling water  Hybrid algal-membrane system for potable water reuse  Produced water treatment and beneficial reuse

High Sodium to Hardness Ratio Resulted in Reuse Challenges  SAR = Sodium Adsorption Ratio SAR = [Na + ] / {([Ca 2+ ] + [Mg 2+ ]) / 2} 1/2 (use meql units) ≤3 6 to 9 > 9

Electrodialysis Consists of Electrodes and A Stack of Membrane Cell Pairs - - - - - - - - - - - - Cathode (-) - - - - - - - - - - - - Cation Exchange Membrane Spacer Repeating Cell Pairs Anion Exchange Membrane + + + + + + + + + + + Spacer Cation Exchange Membrane - - - - - - - - - - - - Feed Anode (+) + + + + + + + + + + +

Electrodialysis with Normal Grade IX Membranes Remove All Cations and Anions Cathode (-) - - - - - - - - - - - - - - - - - - - - - - - - Cation Exchange Membrane Na + Desalted Na + Saline water water Cl - SO 4 2- Ca 2+ Cl - Anion Exchange Membrane + + + + + + + + + + + Na + ED Na + Cl - Cl - Saline water concentrate Cl - Na + Na + - - - - - - - - - - - - Cation Exchange Membrane Na + Ca 2+ Na + Feed Anode (+) + + + + + + + + + + +

Electrodialysis with Selective IX Membranes Remove Preferentially Monovalent Ions Cathode (-) - - - - - - - - - - - - - - - - - - - - - - - - Cation Exchange Membrane Na + Desalted Na + Saline water water Cl - SO 4 2- Ca 2+ Cl - Anion Exchange Membrane + + + + + + + + + + + Na + ED Na + Cl - Cl - Saline water concentrate Cl - Na + Na + - - - - - - - - - - - - Cation Exchange Membrane Na + Ca 2+ Na + Feed Anode (+) + + + + + + + + + + +

Selective Electrodialysis for ZLD of Reclaimed Water Cooling Water Reclaimed water Salty Reclaimed Water with low hardness, higher salinity Na + Na + Na 2 SO 4 Na + Ca 2+ Wetland Na + NaCl Na + 2- Ion SO 4 Switcher Mg 2+ 2- SO 4 Cl - CaSO 4 Ca 2+ MgCl 2 CaCl 2 Cl - Na + Irrigation Mg 2+ Ca 2+ Reclaimed water with low sodium, lower salinity

Selective Membrane Coating

Pilot Site Development

Modeling and Full Scale Design Data Fitting and Mathematical Modeling Bench Testing Water and Salt Balance, Process Modeling Cost Analysis Full Scale Design WATSYS: Specialty EDR Projection Model by GE (Normal Grade Membrane Only) Pilot Testing

Scottsdale Blending Analysis and Cost Comparison – 1 MGD Reclaimed Water Baseline Alternative Alternative 1A Alternative 1 Alternative 2 Normal EDR - Normal EDR - UF + RO Selective EDR WATSYS Testing Feed Water Flow (mgd) 1 Feed Water Sodium (mg/L) 235 % Flow Treated 60.5% 69.0% 78.0% 57.5% Overall Recovery 88% 93% 92% 94% Unit Recovery 85% 90% 90% 90% Blended Water Flow (mgd) 0.88 0.93 0.92 0.94 Product Water Sodium (mg/L) 110 Product TDS (mg/L) 530 522 433 634 Concentrate Flow (gpm) 60 48 54 40 Concentrate TDS (mg/L) 7530 9662 9662 9662 Concentrate Sodium (mg/L) 1524 1927 1715 2287 Number of Product Line - 7 6 6 Number of Stages - 4 4 4 $6.1 $6.5 $7.6 $6.5 Capital ($/gpd product flow) $1.09 $0.88 $0.83 $0.81 O&M ($/kgal) 26% cost reduction using selective electrodialysis

Development of Antifouling Ion-exchange Membranes 1.6 AR204 AR204 3 AR204 + PDA AR204 + PDA 1.4 Energy Consumption (kWh/kgal) AR204 + PDA + 10%TiO2 AR204 + PDA + 10% GO Transport Number SO4/Cl 1.2 AR204 + PDA + 3%TiO2 AR204 + PDA +7.5%GO 2 AR204+ PDA+ 5% TiO2 1.0 AR204 + PDA + 5%GO AR204 + PDA + 7.5% TiO2 AR204 + PDA + 2.5% GO 0.8 0.6 1 0.4 0.2 0 0.0 0 1 2 3 4 5 6 7 8 9 10 0% 5% 10% 15% 20% 25% 30% Conductivity Cut Current Density (mA/cm2)

Highlights of Research Projects  Selective electrodialysis for non-potable water use, e.g., irrigation and thermal power plant cooling water  Hybrid algal-membrane system for potable water reuse  Produced water treatment and beneficial reuse

Treatment Technologies Leading to Potable Water Reuse Primary&Secondary Tertiary Disinfection Microfiltration treatment filtration Advanced Degas/Lime Oxidation Injection Reverse Osmosis

Energy Savings in ‘Engineered Osmosis’ Brine Draw Reconcentration Feed Solution ∆ P= ∆π Brine Feed Osmosis Forward Osmosis (FO) “ engineered osmosis ”

Integrated FO-RO System for Algae Separation and Potable Water Recovery

Integrated FO-RO System for Algae Separation and Potable Water Recovery

Potable Water Recovery Primary and Secondary Primary Parameters Product water Maximum Contaminant effluent Level pH 7.64 6.65 6.5-8.5 √ TDS (mg L -1 ) 765 311 500 √ TOC (mg L -1 ) 30.7 2.0 Na + (mg L -1 ) 142 103 250 √ Cl - (mg L -1 ) 187 174 250 √ - (mg L -1 ) NO 3 2.5 2.4 10 √ F - (mg L -1 ) 0.02 BDL (<0.008) 2 √ 2- (mg L -1 ) SO 4 131 1.1 250 √ Cr (µg L -1 ) 14.7 6.41 100 √ Fe (µg L -1 ) 1145.8 23.89 300 √ As (µg L -1 ) 2.7 0.06 √ 10 √ Se (µg L -1 ) 6.3 BDL (<0.01) 50 √ Cd (µg L -1 ) 0.2 0.05 5 √ Ba (µg L -1 ) 19.6 3.15 2000 √ Pb (µg L -1 ) 3.9 0.97 15

Fate and Transport of Organic matter Primary Algal Draw effluent treatment solution Fluorescence Fulvic excitation Humic emission Protein matrix Product water

2017 International Environmental Design Contest Awards

Highlights of Research Projects  Selective electrodialysis for non-potable water use, e.g., irrigation and thermal power plant cooling water  Hybrid algal-membrane system for potable water reuse  Produced water treatment and beneficial reuse

Produced Water Treatment and Beneficial Uses Produced Water Treatment Plant Shale Stream augmentation gas Potable Water Treatment Plant Livestock & Crop Domestic Home Use Irrigation  Target water quality  Other beneficial reuse options ● Hydraulic fracturing requirements are defined for  Disposal via deep well ● Industrial processes, power plants each beneficial use category injection ● Municipal- Dust and fire control based on existing standards

Produced Water Treatment Tool Box Developed in Xu’s Research Group Membrane processes: Membrane Water quality MF, NF, RO, fouling and analysis (inorganic, ED characterization organic, toxicity) Novel Photocatalysis Produced Water desalination & oxidation processes: Characterization, CDI, EDI, FO Treatment, Reuse Innovative biological and Decision bioelectrochemical Support Tool processes Selective Coagulation and removal of adsorption contaminants 2- , I 2 ) (e.g., SO 4 28

Challenges – Limited Lab Space

Pei Xu: pxu@nmsu.edu