Shuang Xue, Ying Liu, Yang Wen, Fayun Li, School of Environment

Abstract: Dissolved organic matter (DOM) in surface waters has important implication for water quality, and  also plays an important role in the distribution, bioavailability, and toxicity of pollutants in waters. The distribution, spectroscopic characteristics and chlorine reactivity of DOM fractions in the North Canal in Shenyang during icebound season were investigated. DOM was fractionated using XAD resins into five fractions: hydrophobic acid (HPO-A), hydrophobic neutral (HPO-N), transphilic acid (TPI-A), transphilic neutral (TPI-N) and hydrophilic fraction (HPI). The results showed that dissolved organic carbon (DOC) concentrations in river waters were relatively high during icebound season. DOC values of the bulk DOM, HPO-A, TPI-A and TPI-N in ice phase were lower than those corresponding values in liquid phase. The variation trend of absorbance of ultraviolet light at 254 nm (UV₂₅₄) along the direction of water was inconsistent with that of DOC in both liquid and ice phases.  HPO-A and TPI-A were the dominant ultraviolet (UV)-absorbing compounds in both liquid and ice phases. The variation trend of fluorescent materials in ice phase along the direction of water was similar to that in liquid phase. HPO-A, HPO-N and TPI-N were the main trihalomethane precursors in both liquid and ice phases. Trihalomethane formation potential (THMFP) of HPO-A, TPI-A, HPO-N and TPI-N in ice phase was lower than that in liquid phase. Such knowledge can assist in our understanding of DOM dynamics in urban rivers during icebound season, and thus provides improved insight into the development of effective water quality management.

Read the article here:   128-The distribution and characteristics of dissolved organic matter fractions in urban rivers during icebound season.pdf