Soluble microbial products in pilot-scale drinking water biofilters with acetate as sole carbon source

A comprehensive study on formation and characteristics of soluble microbial products (SMP) during drinking water biofiltration was made in four parallel pilot-scale ceramic biofilters with acetate as the substrate. Excellent treatment performance was achieved while microbial biomass and acetate carbon both declined with the depth of filter. The SMP concentration was determined by calculating the difference between the concentration of dissolved organic carbon (DOC), biodegradable dissolved organic carbon (BDOC) and acetate carbon. The results revealed that SMP showed an obvious increase from 0 to 100 cm depth of the filter. A rising specific ultraviolet absorbance (SUVA) was also found, indicating that benzene or carbonyl might exist in these compounds. SMP produced during this drinking water biological process were proved to have weak mutagenicity and were not precursors of by-products of chlorination disinfection. The volatile parts of SMP were half-quantity analyzed and most of them were dicarboxyl acids, others were hydrocarbons or benzene with 16-17 carbon atoms.