七虎林河流域上游溶解性有机质光谱特性分析

七虎林河源头区地表腐殖质随着径流的冲刷进入水体，形成了天然有机质(NOM),其中，溶解性有机质(DOM)易对河流水质造成影响。为了研究七虎林河中DOM的时空分布特征及其对水质的影响，开展了6次采样，分析了水体及土壤吸收光谱和荧光光谱特征参数，利用平行因子(PARAFAC)算法解析了水体DOM的特性及来源。结果表明：七虎林河上游水体五日生化需氧量(BOD₅)、高锰酸盐指数(COD_Mn)、化学需氧量(COD)、可溶性有机碳(DOC)的浓度分别为1.4 mg/L±0.2 mg/L、6.1 mg/L±3.0 mg/L、21 mg/L±8 mg/L、7.0 mg/L±3.2 mg/L,BOD₅/COD平均值为0.08,说明流域内水体DOM的可生化性差，对水质影响较小。光谱特征参数紫外吸收系数(SUVA₂₅₄)、荧光指数(FI)、腐殖化指数(HIX)、生物源指数(BIX)分析结果表明，七虎林河上游云山水库库上林区河段DOM的物质组成与水库及库下河段差异显著。库上河段DOM的芳香碳含量更高、分子量更大、自生源组分...

Absorption and Fluorescence Spectral Characteristics of Dissolved Organic Matter in the Upper Qihulin River Basin

The surface humus at the headwaters of the Qihulin River enters the water body with the erosion of runoff to form natural organic matter (NOM),in which dissolved organic matter (DOM) affects the water quality of the river.To study the temporal and spatial variations of DOM in the Qihulin River,6 sampling exercises were taken.The absorption spectral and fluorescence spectral parameters were calculated,and the characteristics and sources of DOM were analyzed by parallel factor method (PARAFAC).The results showed that the concentrations of BOD₅,COD_Mn,COD and DOC in the upper Qihulin River Basin were 1.4 mg/L±0.2 mg/L,6.1 mg/L±3.0 mg/L,2 1 mg/L±8 mg/L,7.0 mg/L±3.2 mg/L,respectively,and the ratio of BOD₅/COD was 0.08,indicating that the DOM in the area were poor biodegradability and had little impact on water quality.The spectral parameters SUVA₂₅₄,FI,HIX,and BIX showed that the material composition of the upper forest sections were significantly different from which in the Yunshan reservoir and its lower river section.DOM''s aromatic carbon content,molecular weight,terrigenous DOM contribution,and the degree of humification were greater and the content of biological components was lower in the upper forest sections than which in other sections.The aromaticity,relative molecular weight,degree of humification and terrigenous DOM contribution decreased in Yunshan Reservoir sections and its lower river sections.Moreover,the difference between the reservoir sections and its lower river sections was not significant.Similar characteristics were exhibited after anthropogenic pollutants were brought in the river.The PARAFAC algorithm identified 3 fluorescence components,of which 2 were terrestrial humic-like components (C1,C2),1 tryptophan component (C3),and the average fluorescence intensity of humic-like components was 81.0%.The results of soil sample spectroscopy showed that the soil DOM and the river DOM had similar composition.The DOM in Qihulin River was mainly derived from the organic matter released by plant litter in the forest area after the humification process,and the human factor contributed less to DOM.