Removal of Disinfection By-product Precursors Using Hybrid Coagulation-Ceramic Membrane Systems

The goal of this study was to investigate the removal of organics and disinfection by-product (DBP) precursors in an optimized pilot-scale hybrid coagulation-ceramic membrane system treating two surface waters with low specific ultraviolet values (SUVA(254) < 3 L/mg-m). The average removal of dissolved organic carbon was 30% with coagulation pretreatment and negligible without coagulation pretreatment. The removal of organics with coagulation pretreatment also resulted in reduction in the formation potential of haloacetic acids, trihalomethanes, and halonitromethanes in the range of 36 to 46%, 18 to 40%, and 10 to 36%, respectively. The removals of dissolved organic nitrogen, haloacetonitriles, and N-nitrosodimethylamine precursors were found to be negligible. Bromide was not removed from water, which led to an increase in the bromine incorporation factors for halogenated DBPs. The results showed that the implementation of an optimized coagulation pretreatment stage reduced the rate of membrane fouling (80 to 95%) while providing some removal (10 to 50%) of regulated halogenated carbonaceous DBPs.