摘要
通过室内模拟研究了重金属汞（Hg）和除草剂豆磺隆单一和复合污染条件下对草甸棕壤和黑土4个土样脲酶活性和动力学参数的影响。结果发现：汞对脲酶活性、Km、Vmax、Vmax／Km均有负效应，其影响幅度分别为39％～98％、46％～74％、90％-98％、20％～68％；HgCl2浓度与脲酶活性之间符合对数方程，与3动力学参数之间呈显著（P〈0．05）或极显著（P〈0．01）线性负相关；豆磺隆对脲酶有激活作用，除2号土样脲酶活性对不同浓度豆磺隆影响差异不明显外，其余3土样最大增幅分别为17％、18％和15％，原因可能是豆磺隆的加入提高了脲酶酶促反应的初速度；汞、豆磺隆复合污染对脲酶活性和3特征参数均产生负效应，其影响幅度与汞单一污染情况相似，但与污染物浓度之间的相关性较差，豆磺隆的加入使汞与脲酶之间的相互作用趋于复杂。
With incubation test, this paper studied the effects of mercury （ Hg）, chlorimuronethyl, and their combination on the urease activity and its kinetic characteristics in meadow brown soil and black soil. The results showed that Hg had negative effects on the activity, Km, Vmax, and Vmax/Km of soil urease, with the affecting range of 39%-98% , 46%-74% , 90%- 98%, and 20%-68%, respectively. The relationship between soil urease activity and HgCl2 concentration could be described with logarithmic equation, and the Km, Vmax, and Vmax/Km of soil urease were linearly negatively correlated with HgCl2 concentration. Chlorimuron-ethyl could activate soil urease activity, possibly because of the enhancement of initial velocity of urease reaction. The combination of Hg and ehlorimuron-ethyl also had negative effects on the urease activity and its kinetic characteristics, with the affecting range similar to that of Hg, but poorer correlations were observed with the pollutants concentration. The addition of chlorimuron-ethyl made the interaction between Hg and soil urease more complicated.
出处
《生态学杂志》
CAS
CSCD
北大核心
2008年第5期740-744,共5页
Chinese Journal of Ecology
基金
国家自然科学基金项目(40301022)
国家重点基础研究发展规划项目(2004CB418506)
国家自然科学基金重点项目(20337010)
沈阳大学环境工程重点实验室基金资助项目(04001)
关键词
汞
豆磺隆
土壤
复合污染
脲酶
动力学参数
mercury （Hg）
chlorimuron-ethyl
soil
joint pollution
urease
kinetic parameters.
