镍铜砷复合污染对土壤微生物和酶活性的影响

Effects of nickel,copper,and arsenic pollution on soil microorganism and enzyme activities

土壤中的微生物和酶活性是表征土壤质量的重要生物学性状。以甘肃省金昌市金川区宁远堡镇白家咀村冶炼厂附近下风向遭受重金属复合污染的农田土壤为研究对象,采用大田调查的方法对其0~20 cm和20~40 cm土层的重金属(Zn,Pb,Cd,Cr,Cu,Ni,As,Hg)、微生物(细菌、真菌、放线菌)和酶活性(脲酶、碱性磷酸酶、过氧化氢酶、脱氢酶)进行了调查分析。结果表明:(1)土壤在0~20 cm土层,Ni、Cu和As点位超标率依次为15.4%、30.8%和38.5%;在20~40 cm土层,Ni、Cu和As点位超标率均为7.7%。(2)Pb、Hg、Ni、Cu、Cd、As与细菌、脲酶、碱性磷酸酶、过氧化氢酶、脱氢酶呈负相关关系;Cr与放线菌和真菌之间呈正相关关系;Zn与细菌生物量之间呈正相关关系;细菌与放线菌生物量之间呈负相关关系。(3)Pb、Zn和Cr为主导土壤生物学性状的主要因子,其贡献率依次为72.4%、16.2%和4.9%。在铜镍砷复合污染区,过氧化氢酶活性对重金属Cu、Ni、Cd、As较为敏感,可作为该区土壤质量评价的有效指标。

Microorganism and enzyme activities in the soil are important biological indicators of soil quality.Farmland soil polluted by heavy metal in Ningyuanbu Town of the Jinchuan District in Gansu Province was the object of this study.To analyze the content of heavy metals(Zn,Pb,Cd,Cr,Cu,Ni,As,Hg),microorganisms(bacteria,fungi,actinomycetes),and enzyme activity(urease,alkaline phosphatase,catalase,dehydrogenase),26samples in soil layers of 0-20 cm and 20-40 cm were collected.The results showed that the over-standard rates of Ni,Cu,and As in the soil layer of 0-20 cm were 15.4%,30.8%,and 38.5%,respectively.The over-standard rates of Ni,Cu,and As in the soil layer of 20-40 cm were 7.7%.There was a negative correlation between Pb,Hg,Ni,Cu,Cd,and As,along with bacteria,urease,alkaline phosphatase,catalase,and dehydrogenase.Cr showed a positive correlation with fungi and actinomycetes.Zn showed a positive correlation with bacteria.Pb,Zn,and Cr were the major factors that dominated soil biological traits,and the contribution rate was 72.4%,16.2%,and4.9%,respectively.Catalase activity was sensitive to nickel,copper,cadmium,and arsenic pollution,which can be used as an effective index for the evaluation of soil quality in these areas.