镉、铜、铅复合污染对枇杷园土壤微生物的生态毒理效应

Ecotoxicological Effect of Cd-Cu-Pb Compound Pollution on Loquat Soil Microbe

以土壤微生物生化过程与数量、土壤酶活性为指标,通过正交实验,在室内培养条件下探讨了Cd、Cu、Pb复合污染对土壤微生物的生态毒理效应.结果表明,1)Cd、Cu、Pb复合污染可显著降低土壤脲酶、蔗糖酶活性,对土壤过氧化氢酶和磷酸酶则表现出协同抑制或激活效应,不同重金属对土壤酶抑制效应顺序为Cd>Cu>Pb,土壤脲酶、蔗糖酶活性可作为指示土壤Cd、Cu、Pb复合污染程度的预警指标;2)不同微生物对Cd、Cu、Pb复合污染的敏感性为:细菌>放线菌>真菌,对微生物种群数量的影响强度为Cd>Cu>Pb;3)Cd、Cu、Pb复合污染对土壤微生物呼吸强度的影响较小,抑制率普遍较低,个别组出现激活作用.

Combined pollution effects of Cd-Cu-Pb on soil microbial population,biomass and soil enzyme activities were studied using an orthogonal laboratory-incubation experiment. Results showed that：1）combinations of Cd-Cu-Pb could inhibit the soil urease and invertase activities significantly,and had synergic inhibitory or activation effects on soil calatase and phosphatase activities. It was feasible to use soil urease or invertase activities as primary biochemical index to evaluate Cd-Cu-Pb compound pollution. 2）The order of microorganism sensitivity to Cd-Cu-Pb compound pollution was as follows：bacteriaactinomycetesfungi. The orders of inhibition rate of microbial population were proved to be ：CdCu Pb. 3） Effects of Cd-Cu-Pb compound pollution on soil microorganism respiration showed that almost all the treatments had little harm to soil microbe, and few treatments had activation effects. And the T8 treatment （Cd：Cu：Pb =50：400： 88.48,mg·kg-1）had the least harm to soil microbe.