THE DISINFECTION BY-PRODUCT (DBP) REACTIVITY PROFILES

摘要

Dissolved organic matter (DOM) in two surface waters (one with low specific ultravioletabsorbance (SUVA) and the other with high SUVA) were fractionated using fivephysicochemical separation processes (activated carbon, XAD-8 batch adsorption, alumcoagulation, XAD-8 column fractionation and ultrafiltration). Over forty DOM fractions wereobtained for each water. The fractions were characterized using SUVA. Trihalomethane(THMs) and haloacetic acid (HAA9) formation after chlorination of all fractions was quantified.For each natural water, a single and strong correlation was observed between the SUVA valuesof DOM fractions and their THM and HAA9 formations, independent of the separation processesused to obtain the fractions. Therefore, the correlation obtained for each water appears torepresent its natural disinfection by-product (DBP) reactivity profile. However, SUVA is not auniversal predictor of DOM reactivity because a unique DBP reactivity profile was obtained foreach water tested. DBP speciation also correlated well with SUVA of DOM fractions in a singlewater. High-SUVA DOM fractions produced more THMs whereas low-SUVA fractions weremore reactive in forming HAA9. Formation of trichloroacetic acid was dominant overdichloroacetic acid for high-SUVA fractions, whereas the opposite was observed for low-SUVAfractions. DBP reactivity profile provides a promising approach for on-line monitoring andcontrol of DBP formation in practical applications. Understanding how reactivity is correlated toSUVA may allow utilities to optimize the degree of treatment required to comply with D/DBPregulations.