A research project was conducted with the objective of reducing the costs and energyconsumption for inland desalination with zero liquid discharge (ZLD). The project wasfunded by AwwaRF and the California Energy Commission (CEC). The AwwaRF report,Zero Liquid Discharge and Volume Minimization for Inland Desalination, will be issuedin 2007. In ZLD desalination, the concentrate is treated to produce desalinated water andessentially dry salts, and there is no discharge of liquid waste from the site.The technical approach involved treating the concentrate from a primary RO in afluidized bed crystallizer to remove recovery limiting salts, then passing the treatedconcentrate through a secondary RO for further recovery. After the secondary RO, thetotal recovery for most brackish water applications is expected to be 95 to 99 percentusing this approach.The research methodology included computer modeling, bench-scale testing, and pilot-scaletesting. Testing was conducted on groundwater, surface water, finished water, andreclaimed water provided by the project utility partners, City of Phoenix, SouthernNevada Water Authority (SNWA), City of Scottsdale, Beverly Hills, and San AntonioWater System (SAWS). It was estimated that treatment costs would be reduced by 48 to67 percent at the five sites evaluated and that energy consumption would be reduced by68 to 75 percent Includes 4 references, tables, figures.
