Li Cheng-Yao, Huang Ting-Lin, Wen Cheng-Cheng, Liang Wei-Guang, Lin Zi-Shen, Yang Shang-Ye, Li Kai, Cai Xiao-Chun
Key Laboratory of Northwest Water Resource, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Huan Jing Ke Xue. 2021 Mar 8;42(3):1391-1402. doi: 10.13227/j.hjkx.202007276.
To explore the influence of storm runoff on reservoir organic matter during the flood season, the Lijiahe Reservoir was selected to analyze variations in the content and components of dissolved organic matter (DOM) during four periods (before runoff, flood peak period, 1 week after runoff, and 6 weeks after runoff) using three-dimensional fluorescence spectroscopy parallel factor analysis (EEMs-PARAFAC) and ultraviolet-visible (UV-Vis) spectra. The results showed that:① the turbidity and DOC content of the reservoir increased significantly during the flood peak period (<0.01) and gradually decreased thereafter; ② the UV-Vis spectrum characteristics showed that (254) and (355) were significantly increased in the flood peak period (<0.01) while E2/E3 and E3/E4 were significantly decreased (<0.01), indicating that the concentration, relative molecular weight, and degree of DOM humification in the reservoir were increased by storm runoff; ③ four DOM components were identified as terrestrial humus (C1 and C2), microbial humus (C3), and a tryptophan-like component (C4). The fluorescence intensity of the C1-C3 components increased significantly during the flood peak period (<0.05), indicating that the increase in the DOM humic-like component was caused by the storm runoff. At the same time, a decrease in the fluorescence intensity of the C1-C4 components was observed after the flood peak period, indicating that DOM continuously settled and degraded after runoff; and ④ Pearson's correlation analyses showed that DOM fluorescence intensity and turbidity were significantly correlated (>0.467, <0.05), indicating that the observed decrease in DOM content was related to the sedimentation of suspended solids. A principal component analysis (PCA) showed that the water quality in the reservoir reflected the observed characteristics during the different runoff periods. Overall, this study reveals the effects of the storm runoff on DOM content and its components over the short and long term, providing scientific support for the management of drinking water quality.
为探究汛期暴雨径流对水库有机质的影响，选取李家河水库，采用三维荧光光谱平行因子分析法（EEMs-PARAFAC）和紫外可见（UV-Vis）光谱，分析了四个时期（径流前、洪峰期、径流后1周和径流后6周）溶解有机 matter（DOM）含量和组分的变化。结果表明：①洪峰期水库浊度和DOC含量显著增加（<0.01），此后逐渐降低；②UV-Vis光谱特征表明，洪峰期（254）和（355）显著增加（<0.01），而E2/E3和E3/E4显著降低（<0.01），表明暴雨径流增加了水库中DOM的浓度、相对分子质量和腐殖化程度；③确定了四种DOM组分，分别为陆地腐殖质（C1和C2）、微生物腐殖质（C3）和类色氨酸组分（C4）。洪峰期C1-C3组分的荧光强度显著增加（<0.05），表明DOM类腐殖质组分的增加是由暴雨径流引起的。同时，洪峰期后观察到C1-C4组分的荧光强度降低，表明径流后DOM不断沉降和降解；④Pearson相关性分析表明，DOM荧光强度与浊度显著相关（>0.467，<0.05），表明观察到的DOM含量降低与悬浮固体的沉降有关。主成分分析（PCA）表明，水库水质反映了不同径流时期的观测特征。总体而言，本研究揭示了暴雨径流对DOM含量及其组分的短期和长期影响，为饮用水质量管理提供了科学依据。
