贵州草海水体溶解性有机物的荧光光谱特征及来源解析

Fluorescence spectral characteristics and source apportionment of dissolved organic matters in water of Caohai Lake,Guizhou Province.

为探明草海水环境污染物分布特征及来源状况,采用三维荧光光谱技术结合平行因子分析法,对草海水体中溶解性有机物组成特征进行剖析,分析有机物组分在枯水期和丰水期的浓度特征及分布差异,并采用多个荧光指数解析水体溶解性有机物的来源.结果表明,草海水体溶解性有机物中包含2种类型的4种组分,即自生源产生的腐殖质类物质C1(360/450)、C2(390/509)、C3(330/400);陆源输入的蛋白质类物质C4(280/350),4种组分在具有明显的区域差异性,枯水期自中心向边缘递减,具有同源性表征;丰水期由于受周边村庄、农田外源输入的影响呈自东南部向西北部递减.荧光特征参数分析结果显示,水体DOM的FI>1.4,主要为自生内源产生辅以部分陆源输入的方式,以新近产生的有机物相对浓度高,腐殖化程度低,类腐殖质物质(占95%)相对浓度远大于类蛋白物质(占5%).4个有机物组分与水中氮、磷、重金属都呈现了不同程度的相关性,枯水期相关性较丰水期尤为显著.研究显示,草海水体物质来源以内源产生为主,外源输入为辅,亦证明草海近年水环境管理措施取得明显成效,今后的污染防治方案应加强内源污染物的治理.

In order to figure out the distribution characteristics and sources of environmental pollutants in Caohai Lake,the 3D excitation-emission matrix fluorescence spectra(3D-EEMs)technique was combined with the parallel factor analysis(PARAFAC)method to analyze the composition characteristics of dissolved organic matters(DOMs)in the water body of Caohai as well as the concentration characteristics and distribution difference of organic matter components in dry season and wet season.Multiple fluorescence indexes were used to explore the sources of DOM sources in the water body.The results showed that the DOMs in the water of Caohai Lake contained four components of two types,namely self-generating humic-like substances C1(360/450),C2(390/509)and C3(330/400);protein-like substance C4(280/350)input from terrestrial sources.The four components varied from region to region,and their contents were progressively reduced from center to margin in the dry season with homologous representation;influenced by the inputs from surrounding villages and farmlands in the wet season,they were progressively reduced from the southeast to northwest.According to the analysis results of fluorescent spectral parameters,FI value of DOMs in the water body was greater than 1.4,these DOMs were mainly produced from self-generating endogenous sources,assisted by some terrestrial sources.The relative concentration of organic matters newly generated was high,with low humification degree,and the relative concentration(95%)of humus-like substances was much higher than that(5%)of proteinoid substances.The four organic matter components were correlated with N,P,and heavy metals in the water to different degrees,and the correlations in dry season were especially more significant in comparison with those in the wet season.The study shows that the substances in the water body of Caohai Lake are mainly generated from endogenous sources,along with exogenous inputs,and this also proves that the water environmental management measures taken in Caohai Lake have achieved significant results in recent years.Furthermore,the control of endogenous pollutants should be strengthened in the future pollution prevention scheme.