大冶矿区土壤重金属积累对土壤酶活性的影响

Influence of heavy metals pollution on the activities of soil enzyme in Daye mineral district in Hubei province, China

大冶矿区位于湖北省的东南部,是我国的青铜之乡,长期的采矿和冶炼活动已使该矿区土地生产力和农产品品质严重下降。为了探明相关重金属的污染状况,应用野外调查与采样分析相结合的方法,研究了大冶矿区土壤酶活性和土壤中重金属的累积特性。结果表明:矿区土壤Cu、Pb、Zn、Cd、As全量的平均值分别是该区土壤背景值的35.1倍、16.0倍、3.0倍、29.8倍、1.1倍。不同样点土壤酶活性存在一定程度的差异。土壤重金属胁迫对土壤酶活性主要表现为抑制作用,其中对土壤重金属响应较敏感的酶为脲酶和过氧化氢酶,这两种酶与重金属Cu、Pb、Zn、Cd、As的全量分别呈显著或极显著的负相关。这些研究结果对于大冶矿区土壤环境质量评价及生态修复有一定的指导意义。

Daye mineral district, located in the southeastern of Hubei province in China, is famous for its bronze. However, the production of land and the quality of agricultural products have been a tremendous decline owing to waste from the industries of mining and smelting in this area. In order to exploit the status of heavy metals concerned including Copper（Cu）, Lead（Pb）, Zinc（Zn）, Cadmium（Cd）, Chromium（Cr） and Arsenic（As）, the accumulation characteristic of those heavy metals and the soil enzyme activities in soil of Daye Mineral District were investigated by field survey and sampling analysis. The results indicated that the concentrition of total Cu, Pb, Zn, Cd and As in the mineral area soil were 35.1, 16.0, 3.0, 29.8 and 1.1 times the background value of those heavy metals in the soil respectively. The soil enzyme activities varied in different sampling points, and were inhibited by the stress of heavy metals. Results presented here showed that the activities of urease and catalase were sensitive to the stress of heavy metals in soils. These two kinds of enzyme activities were remarkably negative correlated with the concentration of total Cu, Pb, Zn, Cd and As in soils of Daye mineral district, so they can be better index for evaluation of heavy metal pollution in mining area. The findings mentioned above will be playing an important role in helping evaluate soil environmental quality and remediate it for us.