重金属汞、镉单一胁迫及复合胁迫对土壤酶活性的影响  

Effects of Single Stress and Combined Stress of Hg and Cd on Soil Enzyme Activities

作　　者：高大翔[1] 郝建朝[1] 金建华[2] 崔晓星[1] 李丹[1] 孙书洪[2] 刘惠芬[1] 

机构地区：[1]天津农学院农学系,天津300384 [2]天津农学院水利系,天津300384

出　　处：《农业环境科学学报》2008年第3期903-908,共6页Journal of Agro-Environment Science

基　　金：天津市科委科技攻关重大课题(06YFGZNC06700)

摘　　要：采用恒温培养箱培养方法,通过室内模拟重金属污染土壤,研究了不同浓度、不同胁迫时间下Hg、Cd单一胁迫及Hg+Cd复合胁迫对土壤中脲酶及脱氢酶活性的影响。结果表明,Hg、Cd对土壤脲酶及脱氢酶活性均具有显著的抑制作用,随着胁迫时间的延长,两种酶活性均随着重金属Hg和Cd浓度的增加而减小,其中,汞镉混合胁迫的抑制强度最大,Hg次之,Cd相对较小。Hg、Cd、Hg+Cd浓度与脲酶、脱氢酶活性存在着显著的相关,脲酶和脱氢酶活性均可作为土壤Hg、Cd及Hg+Cd污染程度的生化监测指标。不同处理时间脲酶的ED50值大于相应的脱氢酶,说明脱氢酶活性对重金属污染比脲酶更敏感;Hg的ED50值远小于Cd,说明Hg的土壤生态毒性远大于Cd。Effects of different concentrations of two heavy metals （Hg, Cd and Hg＋Cd） applied to soil samples collected from Tianjin agricultural college experimental field for 6 weeks on soil urease activity and dehydrogenase activity were studied. The results showed that Hg and Cd had a remarkable inhibition effect on soil urease activity and dehydrogenase activity. During the treatment of 35 days, the activities of urease and dehydrogenase decreased with the increase of the concentrations of Hg and Cd. The strongest of inhibition level was found in the treatment of combination of Hg＋Cd. The correlation between the urease and dehydrogenase activity could he used as biochemical indicators for monitoring soil pollution by Cd and/or Hg. The ED50 values of urease activity were higher than those of dehydrogenase under same treatments with Hg, Cd or Hg＋Cd, indicating that soil dehydrogenase was more sensitive than urease to heavy metals pollution, while, the ED50 values of Hg were significantly lower than those of Cd, suggesting that the soil ecological toxicity of Hg was higher than that of Cd.

关 键 词：土壤脲酶 土壤脱氢酶 汞 镉 ED50 

分 类 号：X53[环境科学与工程—环境工程]