六价铬对土壤脱氢酶活性的影响  

Soil Dehydrogenase Activity Affected by Chromium(Ⅵ)

作　　者：蔡少华[1] 和文祥[2] 呼蕾[1] 闫晋晋[1] 

机构地区：[1]西北农林科技大学生命科学学院,陕西杨凌712100 [2]西北农林科技大学资源环境学院,陕西杨凌712100

出　　处：《西北农业学报》2008年第5期208-214,共7页Acta Agriculturae Boreali-occidentalis Sinica

基　　金：西北农林科技大学"青年学术骨干人才支持"计划项目;国家自然科学基金项目(40301022)

摘　　要：采用模拟方法较为系统地研究了六价铬水溶态和总量对土壤脱氢酶活性的影响,结果表明：六价铬进入土壤后,水溶态铬含量迅速降低,其降幅随培养时间延长而减缓,并与外源总铬达极显著正相关;根据Langmuir模型计算得到两类土样六价铬的最大吸附量范围为181.82～238.10 mg/kg;铬可显著或极显著抑制土壤脱氢酶活性,且土壤脱氢酶活性随土壤肥力水平降低明显递减,揭示脱氢酶活性可作为土壤铬污染程度的指标之一;风沙土、红壤轻度和中度污染时土壤总铬量范围分别为24.34～33.97、15.60～31.23和121.72～169.84、78.01～156.14 mg/kg,对应的水溶态铬量分别为4.40～10.12、0.23～4.28 mg/kg和21.98～50.59、1.14～21.38 mg/kg;随培养时间的延长,风沙土脱氢酶活性呈现出递减的规律性变化;风沙土和红壤高、低肥脱氢酶活性与六价水溶态铬含量的相关系数分别是-584＊＊、-0.635＊＊,-0.523＊＊和-0.417＊＊,均达极显著负相关,揭示土壤中水溶态重金属含量对土壤生化活性具有重要的影响。By simulative method,the relationship between soil dehydrogenase and chromium（Ⅵ） including the total and the water-soluble concentrations was systematically studied.The results showed that the concentration of water-soluble chromium（Ⅵ） remarkably decreased after chromium（Ⅵ） added in the soil,and the decreasing content was slowed down with culturing time increasing.Their relationship reached remarkable significant positive correlation between water-soluble and total chromium（Ⅵ） concentration.The maximum absorption of two soil calculated by Langmuir equation was 181.82～238.10 mg/kg.Soil dehydrogenase activity which decreased remarkably with the decline of soil fertility could be an index of soil polluted by chromium（Ⅵ） because it significantly inhibited soil dehydrogenase activity.Sandy and red soil total chromium（Ⅵ） contents were 24.34～33.97、15.60～31.23 and 121.72～169.84、87.47～139.58 mg/kg,and water-soluble chromium（Ⅵ） concentrations were 5.00～10.12,0.23～4.28 mg/kg and 20.00～50.59,1.14～21.38 mg/kg for the slight and medium pollution by chromium（Ⅵ） respectively according to ED10 and ED50 values.The dehydrogenase activity of sandy soils decreased continuously with culturing time increasing.Correlation coefficients reached-584,-0.635,-0.523,-0.417 between soil dehydrogenase activity and the water-soluble chromium（Ⅵ） concentrations for Sandy and red soil tested respectively,showed that there was important effect of water-soluble heavy metal on soil biochemical properties.

关 键 词：土壤脱氢酶 六价铬 水溶态 最大吸附量 

分 类 号：X53[环境科学与工程—环境工程]