AWWA MTC53722

Many studies have shown nanofiltration (NF) to be a viable technology fordisinfection byproduct (DBP) precursor control. However, only recently has itbeen demonstrated that molecular diffusion plays an important role in thetransport of DBP precursors across NF membranes. Additionally, to-date most watertreatment NF studies have been highly site specific and no theoretical frameworkfor DBP precursor removal is currently available. Because most NF studies havebeen conducted for regulatory purposes and because stable commercial standardsand analytical methods were not available for certain haloacetic acids (HAAs),much DBP precursor removal data have been presented in the form of totaltrihalomethane (TTHM) and HAA5 mass concentrations. Such analyses have ignoredchanges in DBP speciation that may have large implications for cumulative riskreduction because individual DBP species have different toxicological effects onhumans. The objectives of this paper are to develop and verify a simplemathematical model for diffusion-limited rejection and to quantify changes inDBP relationships upon nanofiltration. Includes 3 references, figure.