AWWA JAW68766

Many communities need affordable inland desalination to meet increasing water demands by making brackish water sources available for use in supplementing existing water supplies or to control the salinity of current sources. Most desalination technologies generate two streams, a desalinated product water stream and the saline byproduct referred to as concentrate. Management of the concentrate stream, typically 15-30% of the feed flow, presents the greatest challenge to implementing desalination. This research demonstrated the novel use of existing technologies to reduce the cost and energy consumption for desalination with zero liquid discharge (ZLD) of concentrate. Test results indicated treatment of the concentrate for further recovery by a second application of reverse osmosis could lead to significant reductions in desalination costs and energy consumption to achieve ZLD. The approach described here could cut ZLD costs by 50-70% and reduce energy consumption by 60-75% compared with established methods currently in use. Includes 10 references, tables, figures.