Characterizing the effects of stormwater runoff on dissolved organic matter in an urban river (Jiujiang, Jiangxi province, China) using spectral analysis

Abstract

The effect of stormwater runoff on dissolved organic matter (DOM) in rivers is one of the central topics in water environment research. Jiujiang is one of the rst cities established in the Green Development Demonstration Zone of the Yangtze River Economic Belt (Jiangxi Province, China). Three-dimensional excitation-emission matrix uorescence with parallel factor analysis (3DEEM-PARAFAC) and ultravioletvisible (UV-Vis) spectroscopy were used to explore the effects of runoff on organic matter in Shili River (Jiujiang, Jiangxi Province, China). The results show that the runoff led to an increase of some critical pollutants and DOM concentrations, especially in the middle reaches of the river. The concentration and relative molecular weight of DOM in water increased as a result of runoff. Three humic-like (C1-C3) and two protein-like (C4 and C5) components of DOM were identi ed using the PARAFAC model. The sources of the three humic-like components were consistent, unlike those of the protein-like component C4. The runoff contained lower amounts of humic compounds which caused the relative content and proportion of humic substances little change and protein-like species increasing. The DOM mainly derived from autochthonous sources, and runoff had limited effect on its characteristics. The PARAFAC components could adequately represent different indicators and sources of DOM in urban rivers, providing an important reference for urban river management.

Fluorescence spectroscopy for tracking microbiological contamination in urban waterbodies

“…The wet weather samples presented lower humic character (lower HIX and lower terrestrial humic-like components) and higher microbial loading (higher protein-like components) than the dry weather samples. These results were consistent with the values obtained in an urban river in China (Yuan et al, 2023).…”