湘江长沙段沿岸常见农作物重金属污染研究——Zn、Cu、Pb和Cd的富集规律及污染评价

Studies of heavy metal pollution in 10 crops planted by Changsha section of Xiangjiang River: Enrichment and pollution evaluation of Zn, Cu, Pb and Cd

由于受污水的长期影响,湘江流域土壤和农作物中重金属的富集已成为重要的环境问题之一。为此对湘江流域长沙段沿岸的10种常见农作物(芝麻、辣椒、甘蓝、空心菜、大蒜、红菜苔、胡萝卜、白萝卜、莴笋、豌豆)中的Zn、Cu、Pb和Cd含量进行了分析,采用单项污染指数法和尼梅罗综合污染指数法对农作物污染情况进行了评价。结果表明:10种农作物中重金属含量依次为Zn>Cu>Pb>Cd;除胡萝卜、白萝卜外,其他试验农作物以根部积蓄重金属能力最强;非食用性组织富集重金属的能力比可食用性组织强;湘江流域长沙段沿岸农作物中重金属以Pb、Cd污染较为严重。

The heavy metal enrichment in soil and crops in Xiangjiang River Basin is still one of today’s environmental problems which can not be ignored. Ten kinds of crops were colleted from both sides area of Changsha section of Xiangjiang River in 2013. Zn, Cu, Pb and Cd contents in the ten crops were measured. The pollution degree of ten crops by heavy metals were evaluated with single factor index method and Nemerow Synthetical Pollution Index. The results show that the contents of these four heavy-metal elements in 10 crops samples ranked from big to small as follows: Zn>Cu>Pb>Cd; The roots of eight crops, except carrot and radish, accumulated the most heavy metal elements than other parts; The un-edible parts of the crops had more accumulation than that in the edible parts; Pb and Cd pollutions in the crops in Changsha section of Xiangjiang River Basin were more serious and should be given attention.