巢湖流域丰水期可溶态重金属空间分布及污染评价

Spatial Distribution and Pollution Assessment of Dissolved Heavy Metals in Chaohu Lake Basin During the Wet Season

探究了巢湖流域丰水期湖区及10条环湖河流水体中重金属元素V、Cr、Mn、Ni、Cu、Zn、Pb、Cd、Fe和Sb空间分布特征.结果表明,丰水期巢湖西部和西北部4条环湖河流中的重金属元素平均质量浓度高于中部和东部地区;金属元素浓度相关性分析结果显示,Cu、Ni、Zn、Pb和Cd元素质量浓度之间呈显著正相关,这说明5种元素间存在相似的空间规律.单因子污染指数评价结果表明,10条环湖河流中Cr各点位均符合地表水Ⅰ类水标准;Pb符合Ⅰ~Ⅱ类水标准;Cu和Zn符合Ⅰ~Ⅴ类水标准;Fe、V和Sb均远低于水标准限值;Ni在南淝河的部分点位轻微超标;Mn在十五里河和派河的部分点位轻微超标;Cd在南淝河的部分点位严重超标;塘西河一个点位中Mn除外,V、Cr、Ni、Cu、Zn、Pb和Fe均小于1,为清洁和无污染水平;综合污染指数评价结果发现,西北部环湖河流的综合污染指数相比西南部、中部与东部是最高的.

The spatial distribution characteristics of the mass concentration of V,Cr,Mn,Ni,Cu,Zn,Pb,Cd,Fe,and Sb in the Chaohu Lake basin and ten surrounding rivers during the wet season were explored.The results showed that the average mass concentration of heavy metals in the western and northwestern Chaohu Lake surrounding rivers was higher than that in the central and eastern regions.The correlation analysis showed a significant positive correlation between the concentrations of Cu,Ni,Zn,Pb,and Cd,which indicated a similarity of spatial distribution among the five elements.The single-factor pollution index evaluation results classified Cr in the ten surrounding rivers as Grade I based on the Environmental Quality Standards for Surface Water.Pb was classified as GradeⅠ-Ⅱ;Cu and Zn as GradeⅠ-Ⅴ;Fe,Sb,and V were far below the standard limit;Ni slightly exceeded the standard at some sampling points of the Nanfei River;Mn slightly exceeded the standard at some points of the Shiwuli and Pai River;Cd exceeded the standard at some points of the Nanfei River.Except Mn at one point of the Tangxi River,V,Cr,Ni,Cu,Zn,Pb,and Fe were all<1,which indicated clean and pollution-free level.The integrated pollution index of the rivers surrounding the lake in the northwestern part was the highest compared to the southwestern,central,and eastern parts.