THE EFFECTS OF CHLORINE DIOXIDE ON REVERSE-OSMOSIS MEMBRANES

Reverse osmosis membrane systems generally require treatment with a sanitizing agent to prevent microbiological growth. As many membrane materials are intolerant to chlorine, alternative sanitizers have to be considered. This work presents the results of a study on the compatibility of several commercially available RO membranes to chlorine dioxide, an oxidizer which compares favorably to chlorine in terms of bactericidal efficacy. The compatibility of the membranes was determined as a function of chlorine dioxide concentration, solution pH, and exposure time. A kinetic model of the membrane degradation phenomena was derived, correlated to the data, and then used to predict useful membrane lifetime in feedwaters containing chlorine dioxide.