NOM removal for extension of chlorine dioxide residuals and lower biological regrowth potentials

Abstract

Techniques to decrease the rate of chlorine dioxide (ClO2) decay in a treated water from Whitfield, Australia were investigated. Biofiltration, microfiltration (MF) and ultrafiltration (UF) were considered as possible means of removing organic compounds which react with the ClO2. Membrane filtration removed more organic material than biofiltration, but biofiltration led to greater ClO2 durations and lower biological regrowth potentials than MF or UF. The results indicated that biofiltration was able to preferentially remove the fast reacting component of organic material that led to rapid ClO2 decay and also lowered the biological regrowth potential of the water.