| 摘要: |
| 以土娄土为供试土壤 ,设置不同pH及汞、镉浓度处理 ,研究pH对汞镉与土壤脲酶活性关系的影响。结果表明 :在供试pH范围内 ,脲酶活性在pH 5.5～6.0和 8.0～9.0时最大 ;汞镉加入几乎没有改变土壤脲酶最适pH;重金属生态毒性呈现 Hg>>Cd的规律性变化。统计分析表明 ,土壤脲酶活性、最大反应速度和反应速度常数均可在一定程度上表征土壤汞镉污染的程度 ;随重金属浓度增加 ,土壤脲酶Km基本不变 ,Vmax降低 ,表明土壤脲酶受汞镉作用机理主要为非竞争性抑制;在较宽pH范围内 ,土壤严重污染的临界汞、镉浓度分别为 2.098和302.83mg/kg。 |
| 关键词: 土壤脲酶 pH 汞 镉 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金资助项目(39370148) |
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| Effect of pH on relationship between soil urease activity and Hg,Cd |
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| Abstract: |
| The relationship between Lou soil urease activity and Hg,Cd was tested under different pH.The result shows as followings:the optimum pH of soil urease is 5.5-6.0 and 8.0-9.0 among pH tested,and the optimal pH of soil urease would not change when soil was polluted by heavy metals,the order of ecological-toxicity is Hg>>Cd,soil urease activity,reaction maximum velocity and reaction velocity constant can be indexes of pollutant by Hg and Hg+Cd,the reaction mechanism is mainly non-competition inhibition because urease Km and Vmax is unvaried and decreased respectively.This paper also proposed the critical concentration of Hg and Cd is 2.098 and 302.83 mg/kg respectively under different pH tested. |
| Key words: soil urease pH mercury cadmium |
