湘江长沙段土壤和沉积物重金属污染模糊评价及污染源分析

摘要

The degree of heavy metal contamination of soils and sediments was evaluated in this thesis through the utilization of fuzzy comprehensive evaluation by investigating the contents of heavy metals ( As, Pb, Cd, Cr, Hg) in samples taken from Changsha section of the Xiangjiang river.The results show that the heavy metal contam-ination of soils and sediments is serious in this area.The dominant contaminative elements in soils are Cd and Hg, and the main contaminative elements in sediments are Cd, As and Pb.These elements can be divided into three categories by using cluster analysis, the first kind:As, Pb;the second kind:Cd, Hg;and the third kind:Cr.At the same time, by using the TiO2 as base line, the pollutant source of the sediments in this area was analyzed.It can be deduced that the heavy metals As, Pb are mixtures of natural and anthropogenic processes, while the source of contaminations of Cd, Hg and Cr are mainly anthropogenic.%通过对湘江长沙段土壤和沉积物中重金属（ As、Pb、Cd、Cr、Hg）质量分数的调查，运用模糊综合评价法对该段土壤和沉积物中重金属污染状况进行了评价．研究结果表明：湘江长沙段土壤和沉积物重金属污染严重，土壤主要污染元素为Cd、Hg，沉积物主要污染元素为Cd、As、Pb．通过聚类分析，可将这5种重金属按来源分为三大类，第一类为Pb、As；第二类为Cd、Hg；第三类为Cr．同时以TiO2为基准，结合粒度效应分析，对该地区的沉积物重金属污染源进行了判别．结果表明：湘江长沙段沉积物中重金属As、Pb的来源为人为源和自然源的混合源；Cd、Hg、Cr污染的来源主要为人为源．