College of Water Sciences, Beijing Normal University, Beijing, 100875, China.
Beijing Key Laboratory of Urban Hydrological Cycle and Sponge City Technology, Beijing, 100875, China.
Environ Sci Pollut Res Int. 2018 Jun;25(18):17967-17979. doi: 10.1007/s11356-018-1972-8. Epub 2018 Apr 22.
Human activities impose important disturbances on both organic and inorganic chemistry in fluvial systems. In this study, we investigated the intra-annual and downstream variations of dissolved organic carbon (DOC), dissolved organic matter (DOM) excitation-emission matrix fluorescence (EEM) with parallel factor analysis (PARAFAC), major ions, and dissolved inorganic nitrogen (DIN) species in a mountainous tributary of the Yellow River, China. Both DOM quantity and quality, as represented by DOC and DOM fluorescence respectively, changed spatially and seasonally in the studied region. Fluorescence intensity of tryptophan-like components (C3) were found much higher at the populated downstream regions than in the undisturbed forested upstream regions. Seasonally, stronger fluorescence intensity of protein-like components (C3 and C4) was observed in the low-flow period (December) and in the medium-flow period (March) than in the high-flow period (May), particularly for the downstream reaches, reflecting the dominant impacts of wastewater pollution in the downstream regions. In contrast to the protein-like fluorescence, humic-like fluorescence components C1 and C2 exhibited distinctly higher intensity in the high-flow period with smaller spatial variation indicating strong flushing effect of increasing water discharge on terrestrial-sourced humic-like materials in the high-flow period. Pollution-affected dissolved inorganic ions, particularly Na, Cl, and NH-N, showed similar spatial and seasonal variations with protein-like fluorescence of DOM. The significant positive correlations between protein-like fluorescence of DOM and pollution-affected ions, particularly Na, Cl, and NH-N, suggested that there were similar pollution sources and transportation pathways of both inorganic and organic pollutants in the region. The combination of DOM fluorescence properties and inorganic ions could provide an important reference for the pollution source characterization and river basin management.
人类活动对河流系统中的有机和无机化学物质造成了重要干扰。本研究调查了中国黄河山区一条支流中溶解有机碳（DOC）、溶解有机质（DOM）激发-发射矩阵荧光（EEM）与平行因子分析（PARAFAC）、主要离子和溶解无机氮（DIN）物种的年内和下游变化。在所研究的区域内，DOM 数量和质量（分别用 DOC 和 DOM 荧光表示）都表现出空间和季节性变化。在人口稠密的下游地区，色氨酸类成分（C3）的荧光强度明显高于未受干扰的上游森林地区。季节性地，在低流量期（12 月）和中流量期（3 月），蛋白类成分（C3 和 C4）的荧光强度比高流量期（5 月）更强，特别是在下游地区，反映了下游地区废水污染的主要影响。与蛋白类荧光相反，腐殖酸类荧光成分 C1 和 C2 在高流量期表现出明显更高的强度，空间变化较小，表明增加的径流量对高流量期陆源腐殖质类物质具有强烈的冲刷作用。受污染的溶解无机离子，特别是 Na、Cl 和 NH4-N，表现出与蛋白类 DOM 荧光相似的空间和季节性变化。DOM 蛋白类荧光与受污染离子，特别是 Na、Cl 和 NH4-N，之间存在显著的正相关关系，表明在该地区存在相似的无机和有机污染物的污染源和运输途径。DOM 荧光性质与无机离子的结合为污染源特征描述和流域管理提供了重要参考。
