云南阳宗海湖底沉积物重金属分布与来源

测定了阳宗海表层沉积物重金属Pb、Cu、Cr、Mn、Zn、As的含量,平均值依次为40.3mg/kg、97.6mg/kg、145.8mg/kg、617.9mg/kg、149.2mg/kg、31.4mg/kg。利用地积累指数法对重金属的污染程度进行评价。结果表明,沉积物中Cu的累积最严重,As、Zn、Cr也发生明显的累积。Mn的累积程度略低,为轻度至中度污染水平。Pb含量接近背景值,显示轻微污染。重金属污染程度顺序为CuAsCrZnMnPb。分析认为,工、矿、旅游业排污等人类活动因素与岩石风化等地球化学过程是沉积物中重金属的两个主要来源,同时也是沉积物中重金属的水平分布产生两种不同特征的主要原因。

A Survey of Heavy Metals in Sediments of Yangzonghai Lake in Yunnan Province:Their Source and Distribution

A survey was conducted in Lake Yangzonghai of Yunnan Province with the particular interest in heavy metals contamination of the sediments. The investigated heavy metals include Pb,Cu,Cr,Mn,Zn and As,which were analysed using X-ray fluorescence spectroscopy and the contamination levels of them were evaluated with the geo-accumulation indexes. The ranking of contamination was as Cu >As >Cr > Zn > Mn >Pb,and according to the investigation of horizontal distribution of contamination levels in the sediments,heavy metal pollution can trace to the human activities such as industrial sources,and the bio-geochemical process,i.e,earth weathering.