砷(As)对稻田土壤的污染研究

Investgation of asenic pollution to rice paddy

目的 观察含砷炼汞废水对稻田土壤所造成的砷污染。方法 在对照田和污染田布点 ,使用土钻以2 0cm厚度为一层 ,对土壤作剖面垂直 3层采样 ,在对照田采样 5 8个 ,污染田 6 0个 ,共采 118个柱状样品 ,测定总砷和可给态砷含量。结果 高背景砷对照田土壤总砷为 16 87mg/kg ,其中可给态砷含量为 1 5 5mg/kg。结论 污染田各层土壤的总砷与可给态砷的垂直含量均值有递减的分布规律 ,但都非常显著地高于对照田相应层 ,说明由于砷污染而改变了土壤的垂直剖面格局。通过对 3层土壤间不同相态砷含量均值的统计分析表明 ,土质为酸性黄壤的稻田 。

Objective To observe rice paddy pollution of waster water from mercury smelt, which contains asenic. Methods After determining certain points both in polluted and control fields, sampling was carried out by means of drilling at each point to get vertical columnar soil samples, 60cm at length and divided into 3 sects equally. Arsenic determination was performed in samples from 58 points of control field and 60 points of polluted field. Results In high background control field arsenic level was 16.87mg/kg, in which dissolvable arsenic was 1.55mg/kg. In polluted field, the total arsenic level and dissolvable arsenic in different layers were showed as descending distribution, but all of them were higher significantly than those in correspond layers from control field. Conclusions The characteristics of arsenic distribution indicated that arsenic vertical distribution in rice paddy were changed as the result of arsenic pollution, and the weak penetrating ability of arsenic in acid loess was showed.