Adsorption of soluble microbial products by sediments.

As major precursors of disinfection by-products (DBPs), soluble microbial products (SMPs) generated by sewage discharge can adversely affect drinking water quality. It is essential to understand the adsorption behaviours of SMPs onto sediments and the effect of DBPs formation. In this study, the adsorption ability of sediments was evaluated by adsorption isotherms with respect to temperature and salinity. Adsorption behaviours were investigated using X-ray photoelectron spectroscopy, electron microscopy analysis, and excitation emission matrix fluorescence analysis. Chlorination was also employed to explore the influence of sediment adsorption on drinking water quality. The results indicated that the maximum adsorption potential of sediments to SMPs was 1.60 mg/g, which involved exothermic processes. SMPs adsorption declined with increasing temperature and salinity, and fulvic acid and protein in SMPs were more readily adsorbed on sediments than was humic acid. Correlation analysis results indicated that adsorption behaviours of sediments to SMPs could significantly reduce the generation potential of DBPs (r = 0.882-0.938, p < 0.01). In addition, the decrease of C-DBPs was considerably greater than that of N-DBPs. These research findings are of importance to assessments of the fate and transport of SMPs in water-sediment systems, as well as the effect of following DBPs formation in the drinking water supply.