Status of reverse osmosis desalination technology

Reverse osmosis (RO), a relatively new technology, is gradually becoming an established and economical method for demineralization of saline waters. Over 50 commercial plants ranging in size from 50,000 gpd to 2 million gpd (2 mgd) are producing fresh quality water for municipal and industrial uses from brackish water sources. The U.S. Congress has authorized construction of a 100 mgd plant in Yuma, Arizona to demineralize otherwise unusable high salinity irrigation return flows as part of the Colorado River Salinity Control. Engineering design and operation details together with cost information on some commercial plants and the planned 100 mgd plant will be presented.A review of the plant operation data indicates that is imperative for the plant owners and equipment suppliers to place due emphasis on providing adequate feed water pretreatment facilities and trained plant operation personnel to ensure trouble-free operation and to achieve furthur economy in desalting costs.Significant advances have been made in the development of RO process for sea water desalination. Soaring energy costs are providing incentive for plant owners to prefer RO plants (up to 100,000 gpd) over vapor compression distillation hardware. Results of the Federal Government Desalting R & D Programs clearly indicate that RO desalting costs will be at least 20–30% lower than distillation.