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闸坝控制下沙颍河沉积物重金属污染特征与生态风险评价

2020-11-02马威樊孔明王萍

安徽农业科学 2020年19期

马威 樊孔明 王萍

摘要 为了解在闸坝控制下沙颍河河段沉积物中重金属污染特征,分别于2015年10月和2016年4月采集沙颍河干流表层沉积物,测定了6种重金属元素的含量;并采用单因子指数和潜在生态危害指数(RI)对污染进行评价。结果表明,2015年10月,沙颍河干流表层沉积物中Cu、Cr、Pb、Zn、Cd、Ni平均含量分别为17.5、78.4、19.8、72.2、0.5、25.8 mg/kg;2016年4月,沙颍河干流表层沉积物中各重金属平均含量分别为16.8、83.2、4.1、56.1、0.8、21.3 mg/kg;Cr平均浓度明显高于河南省土壤环境背景值浓度。单因子风险评价表明,仅Cd为极强污染风险程度,重金属潜在生态风险指数RI值在134~993,平均值为318,属强污染水平。在闸坝的控制下,沙颍河干流中重金属在不同区域表层沉积物中的含量变化较大,污染风险指数差异大。

关键词 闸坝控制;沙颍河;沉积物;重金属污染;生态风险

中图分类号 X826  文献标识码 A

文章编号 0517-6611(2020)19-0077-03

doi:10.3969/j.issn.0517-6611.2020.19.021

Abstract In order to understand the pollution characteristics of heavy metals in the sediments of Shaying River (SYR) controlled by sluice stations,we acquired the surface sediments and determined the concentrations of 6 heavy metals (Cu,Cr,Pb,Zn,Cd and Ni) through field work and laboratory analysis in Oct. 2015 and Apr. 2016,respectively.Pollution assessment was conducted using a single factor index and the potential ecological risk index (RI).The results showed that the average contents of Cu,Cr,Pb,Zn,Cd and Ni were 17.5,78.4,19.8,72.2,0.5 and 25.8 mg/kg  in Oct. 2015,and 16.8,83.2,4.1,56.1,0.8 and 21.3 mg/kg in Apr. 2016.The average concentration of Cr was significantly higher than the concentration of soil environmental background value in Henan Province.The singlefactor risk assessment showed that only Cd was a very strong pollution risk degree,and the heavy metal potential ecological risk index RI value was between 134 and 993,with an average value of 318,which was a strong pollution level.Controlled by the sluice stations,the pollution level and ecological risk of heavy metals were different,and the pollution risk index also different.

Key words Sluice stations;Shaying River;Sediment;Heavy metal pollution;Ecological risk

作者简介 马威(1986—),男,湖北孝感人,工程师,硕士,从事水生态与水环境监测、质量控制与管理工作。*通信作者,工程师,硕士,从事流域水环境监测工作。

收稿日期 2020-03-23

沙颍河作为淮河的最大支流,跨越豫、皖两省,总河长624 km,在安徽颍上县进入淮河。周口市以上河段称为沙颍河上游;周口市到阜阳市河段为沙颍河中游;阜阳市以下河段为沙颍河下游[1]。自20世纪90年代以来,淮河发生的大规模污染事件多与沙颍河有关[2-3]。因重金属污染具有潜在性、持久性和不可逆性,且河流生态系统的开源性易受重金属污染,所以重金属的污染问题在河流生态保护中受到重视,沙颍河污染的控制与治理是淮河治理中的关键[4-5]。……

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