Disposal of concentrates from brackish water desalting plants by means of evaporation technology

Abstract The use of reverse osmosis (RO) plants to desalt brackish water in South Florida has increased rapidly in the last decade. The concentration of scale forming species such as calcium sulfate and silica usually limits RO recovery in these plants to about 75% of the total feedwater flow. The remaining 25% of the flow is reject brine which presents a serious disposal problem for plants in inland locations. This paper describes the use of brine concentrators to reduce the RO reject brine to 2% of the overall flow and so significantly reduce the disposal problem. The hybrid concept of RO followed by evaporative brine concentration has been applied to similar problems