COST EFFECTIVE DEMINERALIZATION FOR IMPROVED RECYCLED WATER QUALITY IN CALIFORNIA

摘要

The San Elijo Joint Powers Authority (SEJPA) delivers an average of 1,250 acre-ft of recycled water each year. Unfortunately, the wastewater quality that is the source water for the SEJPA has degraded over recent years and will soon exceed the permitted 12-month average TDS concentration. As a result, the SEJPA is currently designing an MF/RO system for the SEWRF to reduce the TDS concentration in order to improve the recycled water quality. Prior to embarking on this MF/RO design, the agency made efforts to improve the secondary effluent water quality for key constituents that would impact the capital and operating costs of the MF/RO facility. These improvements included the incorporation of an anaerobic selector in the activated sludge process to stabilize sludge settleability and to provide a consistently high quality secondary effluent. These efforts, along with unique design features of the MF/RO facility at SEWRF, are discussed in this paper. The demineralization facility at the SEWRF will incorporate design flexibility and philosophy never before applied at an advanced treatment facility as a means to cost-effective salinity management.