AWWA JAW34179

A bench-scale ion exchange process with batch biological denitrification of the spent regenerant brine was developed to remove nitrate from drinking water. This research indicates that the combination procedure results in 50 percent reduction of regenerant consumption and 90 percent reduction in the mass of waste salt discharged. The process features a sequencing batch reactor to accomplish the biological denitrification of a 0.5 N sodium chloride spent regenerant solution. Now being pilot tested in California, the process--which is simple, flexible, and reliable--should be suitable for use by small systems. Includes 31 references, tables, figures.