Characterization and isolation of natural organic matter from a eutrophic reservoir

Abstract

Isolation of natural organic matter (NOM) into various organic fractions has proved that it is possible to investigate the characteristics of water samples and by-products formation during chlorination. In this study, three types of resin were used to study water samples collected from a eutrophic reservoir. Seven types of organic fractions such as hydrophobic bases, hydrophobic neutrals, humic acids, fulvic acids, hydrophilic bases, hydrophilic neutrals and hydrophilic acids were isolated; sodium hypochlorite (NaOCl) was used as the oxidant to test the reactivity of each fraction. Experimental results indicated that the distribution of hydrophilic and hydrophobic fractions was similar; also, hydrophilic neutrals were the main constituent of the NOM. When the NaOCl reacted with each organic fraction, fulvic acids generated the highest potential of disinfection by-products such as trihalomethanes and adsorbed organic halides. With respect to the THMFP (trihalomethane formation potential) and AOXFP (adsorbed organic halide formation potential), it was found that a satisfactory relationship could be observed between SUVA (specific ultra-violet light adsorbance) and THMFP or AOXFP. In conclusion, the fulvic acids that can be isolated from a eutrophic reservoir play an important role in both the purification and disinfection steps.