长江流域沉积物重金属污染特征及优控因子筛选

Inspiration for Priority Control of Heavy Metals in Sediments of Yangtze River Basin

本文通过整编2000—2016年长江流域沉积物重金属研究数据,对7种重金属(铜、汞、铅、锌、镉、铬和砷)的含量、空间分布和赋存形态比例进行分析总结,并对其污染风险进行评价。研究结果发现沉积物中镉(Cd)含量超标最严重;从污染风险看,Cd在沉积物中的累积程度和生态风险要远高于另外6种重金属;从赋存形态看,Cd在沉积物中以酸提取态(B1)为主,生物可利用性要高于另外6种重金属,易在环境中迁移转化。本文结果表明Cd是长江流域沉积物的首要重金属污染元素和优控重金属元素。优先关注并重点防控沉积物Cd污染对控制长江流域重金属污染存在积极作用。

It is important to study the characteristics of heavy metal pollution in the sediments of the Yangtze River to control pollution. The authors analyzes concentrations, spatial distributions, and proportions of seven heavy metals(copper, mercury, lead, zinc, cadmium, chromium and arsenic) in the sediments of the Yangtze River Basin during 2000 to 2016, and evaluates pollution risks. The results show that the content of cadmium(Cd) was the most serious heavy metal. From the perspective of pollution risk, the accumulation degree and ecological risk of Cd in the sediments were much higher than that of the other six heavy metals. Cd is mainly in the sediments with acid extraction state(B1), and its bioavailability is higher than that of the other 6 heavy metals, so it is easy to migrate and transform in the environment. The results of this paper indicate that Cd is the primary heavy metal pollution element and excellent control heavy metal element in the sediments of the Yangtze River. Priority attention and focus on prevention and control of Cd pollution has a positive effect on heavy metal pollution in the Yangtze River.