AWWA ACE70884

This powerpoint presentation begins by providing a brief overview of brine minimization and zero liquid discharge (ZLD) at 97% recovery and brine minimization technologies. Pilot study objectives were to: determine realistic flux rates, limiting factors, fouling tendencies, and process stability of two parallel reverse osmosis (RO) processes; demonstrate it is feasible to eliminate liquid discharges to receiving waters from inland membrane treatment systems; and, demonstrate that brine minimization and ZLD technologies are compatible with typical municipal water treatment plant (WTP) operations. Softening and pH lowering of the LPRO concentrate prevents precipitation of supersaturated minerals in the high recovery RO spiral elements. Extensive chemical pretreatment to prevent precipitation of all minerals is not usually required in the VSEPTM process. The pilot study RO concentrate is representative of many brackish groundwater supplies in Colorado. Conclusions are given for high recovery RO, VSEP, ZLD overall cost implications, and salt crystallization. Includes tables, figures.