砷对土壤脲酶活性影响的研究

Effect of arsenic on soil urease activity

采用模拟方法对As污染土壤脲酶特征进行了研究 .结果表明 ,土壤中As浓度在 0～ 2 0 0mg·kg-1浓度范围内 ,反应初期脲酶活性变化无明显规律 ;一年后砷激活土壤脲酶活性 ,二者达到显著或极显著正相关 .随As浓度增加 ,土壤脲酶Km 值基本不变或略有增加 ,Vmax增大 ,从机制上揭示出As加速脲酶 尿素复合物的解离 .厩肥和无肥土样脲酶对As的反应类似 ,只是变化幅度有所差异 .

By simulation method,this paper studied the urease activity in arsenic polluted soils.The results showed that arsenic could activate soil urease activity after added for one year.With arsenic addition,soil urease activity remarkably increased,and there existed a significantly positive correlation.The V max of soil urease increased with arsenic addition,while the K m of urease in high and low fertility soil was unchanged and slight increased,respectively.It is proved that As could accelerate the separating velocity of enzyme-urea complexes.This paper also illustrated that soil properties were important to study the relationship between soil enzyme and pollutants.