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目的了解某市蔬菜基地土壤中铅(Pb)、镉(Cd)、铬(Cr)、镍(Ni)、铜(Cu)、锌(Zn)、砷(As)、汞(Hg)含量及污染程度。方法分别在某市5个蔬菜基地采集84份土壤样品,采用原子吸收光谱法测定Pb、Cd、Cr、Ni、Cu和Zn的含量,原子荧光光谱法测定As和Hg的含量,并根据《农产品安全质量无公害蔬菜产地环境要求》和《土壤环境质量标准》,采用变化程度等级、单项污染指数法和内梅罗综合污染指数法进行评价。结果某市蔬菜基地土壤8种重金属平均含量除Cd高于标准外,其他7种均符合国家标准。蔬菜基地土壤重金属含量变化程度Pb、Ni、Cu、As为1级,属基本无变化、清洁;Cd、Cr、Zn、Hg为2级,属轻度变化、低累积。采用内梅罗综合污染指数法进行评价,综合污染指数为0.86,为2级,属警戒限。结论某市蔬菜基地土壤重金属含量基本符合国家标准要求,总体质量较好,但镉超标情况相对较严重,应引起注意。
Objective To understand the contents and pollution of lead, cadmium, chromium, nickel, copper, zinc, arsenic and mercury in vegetable soils in a certain city. degree. Methods Eighty-four soil samples were collected from five vegetable bases in a city. The contents of Pb, Cd, Cr, Ni, Cu and Zn were determined by atomic absorption spectrometry. The contents of As and Hg were determined by atomic fluorescence spectrometry. Safety Quality and Environmental Pollution-free Vegetable Producing Area “and” Soil Environmental Quality Standard "were evaluated by the degree of change, single pollution index method and Nemerow comprehensive pollution index method. Results The average content of 8 kinds of heavy metals in the vegetable base soil in a certain city except for Cd was higher than the standard, while the other 7 kinds all met the national standards. The contents of Pb, Ni, Cu and As in vegetable base soils varied from 1 level to 1 level, with no change and no significant changes. The levels of Cd, Cr, Zn and Hg were 2 levels, belonging to slight change and low accumulation. Nemero Integrated Pollution Index method for evaluation, the integrated pollution index of 0.86, Level 2, is a warning limit. Conclusion The content of heavy metal in the vegetable base of a city basically meets the requirements of national standards, and the overall quality is good. However, the situation of cadmium exceeding the standard is relatively serious and should be noticed.