AWWA JAW37635

A membrane filtration pilot plant was operated for one year to evaluate the removal of natural organic matter and disinfection byproduct precursors from a highly colored groundwater in Orange County, California. Two nanofiltration (NF) membranes--a traditional softening membrane and a high-permeablility, charged membrane--were selected for pilot-scale testing based on bench scale tests of eight NF and ultrafiltration membranes. The high-permeability NF membrane demonstrated superior organics removal at very high recovery and flux. It also allowed most inorganic constituents to pass through. The concentrate of low total dissolved solids reduced inorganic fouling and made concentrate reuse possible. The article also presents preliminary design criteria and a cost opinion for full-scale treatment facilities. Includes 14 references, tables, figures.