Cr^(3+)、Ni^(2+)单一及复合污染对水稻土酶活性的影响

Effects of Single and Combined Pollution of Cr^(3+) and Ni^(2+) on Soil Enzyme Activities in Paddy Soil

在室内恒温培养条件下,研究了外源Cr3+、Ni2+单一及复合污染对水稻土脲酶、酸性磷酸酶及过氧化氢酶活性的影响.结果表明,低浓度Ni2+处理对脲酶、酸性磷酸酶有不同程度的激活作用,而对过氧化氢酶起一定的抑制作用;中、高浓度Ni2+及各污染水平的Cr3+、Cr-Ni复合污染处理对3种酶活性均表现为抑制作用;Ni2+处理对土壤酶活性的抑制效应顺序为脲酶>酸性磷酸酶>过氧化氢酶;Cr3+和Cr-Ni复合污染处理对脲酶活性的抑制效应最大,对过氧化氢酶、酸性磷酸酶活性的抑制效应相似;Cr-Ni复合污染处理对脲酶、酸性磷酸酶主要表现为协同作用,对过氧化氢酶则主要在污染初期表现为协同作用.

The effects of single and combined pollution of Cr3＋ and Ni2＋ on the activities of urease,acid phosphatase and catalase in paddy soil were investigated through the lab-scale experiment by artificially controlling temperature and humidity.The results showed that urease and acid phosphatase activities were stimulated under low added Ni2＋ concentration in single Ni2＋ treatments,while the activities of the three enzymes in the rest treatments were all inhibited.Ni2＋ inhibited the enzyme activities in the order of urease acid phosphatase catalase,while the enzyme activities were inhibited by Cr3＋ and Cr-Ni combined pollution in the following order of urease catalase≈acid phosphatase.The characteristics of Cr-Ni combined pollution for urease and acid phosphatase mainly exhibited synergistic effect;However,it largely pointed out synergistic effect for catalase in the early period of culture.