巢湖沉积物重金属浓度分布及风险指数

The Concentration Distribution and Risk Index of Sediment Heavy Metals in Lake Chaohu

对2015年初和2016年初在巢湖20个点位上采集的沉积物样品进行测定分析,结合单污染指数和地积累指数对重金属污染进行评价,分析近年疏浚、调水工程产生的影响。总体上,全湖Hg浓度水平处偏重度污染,Cd偏中度污染。从全湖浓度水平年际变化趋势上,巢湖主要污染金属如Cu、Pb、Zn、Cr、Ni、Hg、Cd的浓度水平均在2007年附近达到峰值,随后,除Cd呈明显的下降趋势外,其他重金属均维持在相当水平,并且在2016年初出现了上升。对此,应在加大清淤力度的同时,加强外源控制。

Sediment samples of 20 sites in Lake Chaohu in early 2015 and early 2016 were measured and heavy metal concentrations were assessed with single pollution index and evaluating method of geoaccumulation to analyze the impact of frequent dredging and water diversion projects. The whole lake has a state of partial-heavy pollution level of Hg and a par-tial-moderate pollution of Cd. Concerning the inter-annual variation trend, the main heavy mental elements, such as Cu, Pb,Zn, Cr, Ni, Hg and Cd, all reached relatively high concentrations around 2007. Then, most elements maintained on a similar level and had a rise in 2016, while Cd showed an obviously descending trend in the entire timeline. To deal with this, dredg-ing work should be intensified together with the control of exogenous sources.