The effects of biodegradation on the characteristics and disinfection by-products formation of soluble microbial products chemical fractions.

This study observed the relative contribution of chemical fractions in SMPs and explored the biodegradation of each fraction and their effect on disinfection by-products (DBPs) formation in surface water. The hydrophilic acid (HPIA) and hydrophobic acid (HPOA) constituted the major portion of the SMPs, which were dominated by fulvic acid and humic acids. The transphilic acid (TPIA) and hydrophobic bases (HPOB) were relatively minor but it contained a relative substantial portion of protein-like materials in SMPs. TPIA and HPOB produced insignificant amounts of DBP corresponding to 13% and 14% in the original samples, but they were collectively responsible for 50% of the DBPs yield. Much larger amounts of hydrophobic fractions were utilized than hydrophilic fractions after biodegradation. The increase in SUVA values indicating aromatic structures, except for HPOA fraction, was observed after biodegradation. The protein-like materials in both the HPOA and HPIA fractions and polycarboxylate-type humic acid in the HPIA fraction decreased but the enrichment of HPOA (MW > 100 kDa) and TPIA (MW < 1 kDa) was observed after biodegradation. The production of = C-H in HPIA fraction and the appearance of double peak at 1100 cm-1 in TPIA and HPOB fractions occurred after biodegradation. In overall level, microorganisms effectively utilized DBP precursors from HPIA, HPOA and HPOB fractions but increased the DBPs precursors from the TPIA fraction. TPIA and HPOB fract...
Source: Environmental Pollution - Category: Environmental Health Authors: Tags: Environ Pollut Source Type: research