UPTAKE OF NATURAL ORGANIC MATTER BY ANION EXCHANGE RESINS

摘要

It is well known that during drinking water treatment, natural organic matter (NOM) and chlorine react to form halogenated organic disinfection by-products (DBPs), e.g., trihalomethanes and haloacetic acids. Research has shown that treatment processes such as enhanced coagulation, granular activated carbon adsorption, nanofiltration and anion exchange are viable strategies for removing dissolved organic carbon (DOC; a common surrogate for NOM) from raw drinking waters, thereby reducing the formation of DBPs upon chlorination. Previous work by the authors, consisting of bench-scale batch experiments and a continuous-flow pilot plant study, showed that anion exchange pre-treatment of raw drinking water is very effective at removing DOC and reducing the subsequent chlorine and alum demand. A limitation of these studies was that they were conducted using natural waters that were not well characterized. As a result, it was difficult to make quantitative judgments regarding the impact of raw water quality, NOM characteristics and anion exchange resin properties on DOC removal. Accordingly, the objective of this research was to elucidate the interactions among NOM, competing inorganic anions and anion exchange resins.