土壤粘粒吸附脲酶量的影响因子研究

Studies on the Factors Which Affect Urease Adsorption Amount on Soil Clay

研究了８种土壤粘粒对脲酶的吸附量，以及不同ｐＨ，温度和Ｚｎ（Ⅱ）、Ａｓ（Ⅴ）、Ｈｇ（Ⅱ）质量浓度对脲酶吸附量的影响。结果表明，８种土壤粘粒对脲酶均有吸附，但吸附数量不尽相同。非最适ｐＨ时，脲酶吸附量在弱碱性介质中的下降率大于弱酸性介质；温度升高，脲酶吸附量下降，且去有机质土壤粘粒的下降率大于原样土壤粘粒；Ｚｎ（Ⅱ）、Ａｓ（Ⅴ）、Ｈｇ（Ⅱ）抑制相同比率的脲酶吸附量时，所需３种离子的质量浓度为Ａｓ（Ⅴ）＞Ｚｎ（Ⅱ）＞Ｈｇ（Ⅱ），表现为Ｈｇ（Ⅱ）的抑制作用最强。

The urease adsorption amount on eight kinds of soil clay and that under different pH and temperature and Zn(Ⅱ),As(Ⅴ),Hg(Ⅱ) concentration conditions were studied.The results indicated that urease adsorption amount on eight kinds of soil clay was different.The urease adsorption amount decreased if pH didnt equal.The reduction rate under the weak alkaline medium was greater than that under the weak acidic medium.The results that temperature affected urease adsorption amount were as follows:the higher the temperature,the less the urease adsorption amount.The urease adsorption amount on soil clay from which organic matter was removed was greater than that on the original soil clay.Zn(Ⅱ),As(Ⅴ) and Hg(Ⅱ) could reduce the urease adsorption amount on soil clay.If the same urease adsorption amount was reduced,the order of the three elements concentration was:As(Ⅴ)>Zn(Ⅱ)>Hg(Ⅱ), which indicated that Hg(Ⅱ) could restrain urease the greatest in the three elements.