THE 63 RD ANNUAL NEW MEXICO WATER CONFERENCE October 18, 2018 Treatment Technologies for Alternative Water Sources and Qualities Pei Xu, PhD Civil Engineering Department
Development of Alternative Water Supplies is Crucial for Water Security Produced Water Elevated Salinity High sodium adsorption ratio Water Scarcity Water Reuse Contaminants of emerging concerns Desalination Concentrate
Challenges of Alternative Water Supplies Water quality concerns High cost Intensive energy demand Concentrate and waste management Need Innovative Approaches Short-term solutions: Modify and optimize current technologies Long-term solutions: Develop next generation of technologies
Highlights of Treatment Technologies Produced water treatment Selective electrodialysis for non-potable water use High recovery desalination system
Produced Water Quality Source: Benko and Drewes (2008)
Source: Benko and Drewes (2008) Produced Water Quality Hydraulic Fracking
Source: Benko and Drewes (2008) Produced Water Quality Hydraulic Fracking Salt tolerant crops
Source: Benko and Drewes (2008) Produced Water Quality Hydraulic Fracking Salt tolerant crops Livestock Drinking water Salt sensitive crops
Treatment Technology Assessment Review identified 62 fundamental treatment technologies and integrated systems/processes Commercial status of technology Feed and product water quality Removal efficiencies Water recovery Infrastructure considerations Energy consumption Chemical demand Life cycle O&M considerations
Produced Water Treatment Decision Support Tool
Technology Summary Produced Water Pre-treatment Treatment/Desalination Deep Well Injection Removal of: TSS Organics Hardness Disinfection Waste Disposal TDS Bins (mg/l) < 10,000 10,000 40,000 40,000 70,000 > 70,000 Mature, less costly, existing technology - RO/NF - ED/EDR Mature, cost intensive, existing technology - SWRO - BWRO Moderate mature, moderate costly technology - MVC - MED Emerging, cost intensive technology - FO - MD Reuse for hydraulic fracturing (No desalination required) Beneficial Use Reuse for other purposes (potable use, aquifer recharge, irrigation, industrial, etc.) Recovery of valuable products and energy (I 2, NaCl, NH 4 Cl, MgCl 2, Na 2 CO 3, etc.)
Online Resources for Produced Water
Highlights of Treatment Technologies Produced water treatment and beneficial reuse Selective electrodialysis for non-potable water use High recovery desalination system
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
Selective Electrodialysis for ZLD of Reclaimed Water Salty Reclaimed Water Reclaimed water with low hardness, higher salinity Cooling Water SO 4 2- Ca 2+ Mg 2+ Na + SO 4 2- Ion Switcher Na 2 SO 4 NaCl Na + Na + Na + Na + Wetland Cl - Ca 2+ Na + Cl - CaSO 4 MgCl 2 CaCl 2 Mg 2+ Ca2+ Irrigation 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 Pilot Testing WATSYS: Specialty EDR Projection Model by GE (Normal Grade Membrane Only)
Scottsdale Blending Analysis and Cost Comparison 1 MGD Reclaimed Water (4-stage) Baseline Alternative Alternative 1A Alternative 1 Alternative 2 Normal EDR - UF + RO WATSYS Feed Water Flow (mgd) 1 Normal EDR - Testing Selective EDR Feed Water Sodium (mg/l) 235 Overall Recovery 88% 93% 92% 94% Unit Recovery 85% 90% 90% 90% Product Water Sodium (mg/l) 110 Product TDS (mg/l) 530 522 433 634 Number of Stages - 4 4 4 Capital ($/gpd product flow) $6.1 $6.5 $7.6 $6.5 O&M ($/kgal) $1.09 $0.88 $0.83 $0.81 Selective ED achieved higher water recovery and 26% cost reduction treating municipal reclaimed water
Highlights of Treatment Technologies Produced water treatment and beneficial reuse Selective electrodialysis for non-potable water use, e.g., irrigation and thermal power plant cooling water High recovery desalination system
Highlights of Research Projects Produced water treatment and beneficial reuse Selective electrodialysis for non-potable water use, e.g., irrigation and thermal power plant cooling water High recovery desalination system
High Recovery Desalination Source: Eco1st Source: Aquamembranes
Pei Xu: pxu@nmsu.edu