新乡市大棚菜田土壤重金属积累特征及污染评价

采用微波消解-ICP-AES技术,测定不同种植年限大棚菜田土壤样品中As、Pb、Zn、Cd、Cr、Mn、Ni、Cu等重金属的含量,研究不同种植年限与大棚菜田土壤重金属累积的相关性以及大棚菜田土壤重金属累积特征,并利用地积累指数法进行污染评价。结果表明:大棚菜田土壤重金属Zn、Pb、Ni、Mn和Cu的含量与种植年限具有极显著相关性;大棚菜田土壤中重金属Cd和Cr的含量与种植年限不相关。重金属元素间相关性分析表明,Zn与Pb、Cd、Ni、Mn、Cr、Cu,Pb与Cd、Ni、Mn、Cr、Cu,Cd与Ni、Mn、Cr,Ni与Mn、Cr、Cu,Mn与Cr、Cu具有污染同源性,Cu与Cd、Cr不具有污染同源性。地积累指数法污染评价结果显示Cd的污染等级达到了6级,已构成了极严重污染;Zn和Cu的污染等级达到2级,已构成了中度污染;Pb、Mn的污染等级达到1级,已经构成了轻~中度污染;As、Ni、Cr均未构成污染。

Heavy Metal Accumulation Characteristics and Pollution Assessment of Vegetable Soils in Plastic Shed in Xinxiang

The concentrations of heavy metals As,Pb,Zn,Cd,Cr,Mn,Ni and Cu in vegetable soils of different planting years in plastic shed were measured by ICP-AES with the microwave digestion,and it was studied the correlation between planting years and heavy metal accumulation of vegetable soils,and then it was analyzed heavy metal accumulation characteristics of vegetable soils.Pollution was evaluated by the geo-accumulation index.The results showed that the concentrations of heavy metals Zn,Pb,Ni,Mn and Cu were positively correlated with planting years of vegetable soils;the concentrations of Cd and Cr were not correlated with planting years of vegetable soils.The above analysis indicated that there were homology pollutions between Zn and Pb,Cd,Ni,Mn,Cr,Cu;between Pb and Cd,Ni,Mn,Cr,Cu;between Cd and Ni,Mn,Cr;between Ni and Mn,Cr,Cu;between Mn and Cr,Cu.But there was no homology pollution between Cu and Cd,Cr.Pollution assessment results showed that pollution of Cd reached level 6,and was extremely serious;pollution of Zn and Cu reached level 2,and was moderate;pollution of Pb and Mn reached level 1,and arranged from light to moderate;but pollution of As,Ni and Cr was free.