某铀矿区放射性核素对土壤微生物活性的影响研究

Effects of Radionuclides on Soil Microbial Activity in a Uranium Mining Area

采集了某铀矿区不同浓度放射性核素污染土壤样品,分析了土壤理化性质、放射性核素^(238)U、^(232)Th、^(226)Ra和^(40)K活性浓度、土壤呼吸和土壤酶活的变化情况。结果表明,研究区不同浓度区块土壤呼吸作用随着放射性核素活性浓度的增加而降低,且同一浓度区块不同深度土壤呼吸作用变化不显著;研究区不同浓度区块土壤脲酶、过氧化氢酶、脱氢酶、磷酸酶和芳基硫酸酯酶等5种酶活含量变化差异显著,均随着放射性核素活性浓度的增加而降低,且同一浓度区块不同深度土壤5种酶活含量随着采样深度的增加而变小。放射性核素对土壤微生物活性有较大影响。

Soil samples from different concentrations of radionuclides in typical uranium mining areas were collected.Changes of soil physical and chemical properties,activity concentration of radionuclides ^238U,^232Th,^226Ra and ^40K,soil respiration and soil enzyme activity of soil samples were analyzed.The results show that soil respiration drops with increase of radionuclide concentration in the areas under study with different concentration,and respiration of the same concentration block is not significant at different depths.There are significant differences in content changes of soil urease,catalase,dehydrogenase,phosphatase and arylsulfatase in the soil with different concentration in the areas under study,which drops with increase of concentration of radionuclide activity.Contents of the above mentioned 5 enzymes in the soil of the same concentration at different depths drop with rise of sampling depth.Radionuclides exert a bigger effect on soil microbial activity.