AWWA JAW50208

The batch recycle membrane test (BaReMT) and batch internal recycle membrane test (BaIReMT) were developed as simpler alternatives to the rapid bench-scale membrane test (RBSMT) currently recommended by the Information Collection Rule for evaluating membrane treatment. All three methods were tested on a small (155-cm2 [26-sq-in.]) flat sheet of membrane. Both the BaReMT and BaIReMT require a far smaller batch volume of water sample than does the RBSMT. The patterns of flux decline and recovery were similar in the BaReMT and RBSMT that used water treatment plant samples from Durham and Fayetteville, North Carolina. The fouling tendencies of water treatment plant samples from Durham, Fayetteville, and Raleigh, North Carolina, were similar. Although the mass of natural organic matter on the membrane was small, its estimated concentration in the foulant layer was large. Scanning electron and atomic force micrographs showed that not all foulants were removed from the membrane surface despite extensive cleaning. Only repeated cycles of cleaning can demonstrate the long-term effect of the remaining foulants on flux recovery. Includes 20 references, tables, figures.