磷酸盐对土壤胶体和矿物表面吸附酸性磷酸酶的影响  

EFFECT OF PHOSPHATE ON ADSORPTION OF ACID PHOSPHATASE TO THE SURFACE OF SOIL COLLOIDS AND MINERALS

作　　者：赵振华[1] 黄巧云[1] 李学垣[1] 郭学军[1] 

机构地区：[1]华中农业大学资源与环境学院,武汉430070

出　　处：《土壤学报》2003年第3期353-359,共7页Acta Pedologica Sinica

基　　金：国家自然科学基金 ( 4 0 2 71 0 64);教育部优秀青年教师资助计划

摘　　要：研究了系列浓度磷酸盐体系中 ,酸性磷酸酶在黄棕壤、砖红壤胶体和高岭石、针铁矿及δ MnO2 表面的吸附特点。结果表明 :随着磷酸盐浓度升高 ,磷酸酶在土壤胶体和矿物上的等温吸附曲线类型逐渐由L型向C型转化 ,等温吸附方程由Langmuir方程向线性方程转化 ,这种转化可能与磷酸和酶在胶体矿物表面对不同点位的利用及其能量特点有关。随着体系中磷酸盐浓度的增加 ,酶吸附量呈现先急剧下降后逐渐稳定的趋势。磷酸盐对土壤胶体和矿物上酶吸附的影响决定于矿物表面的类型特别是羟基的数量、体系中磷酸盐浓度及酶的加入量。针铁矿及含铁铝氧化物较多的砖红壤胶体对酶的吸附受磷酸盐的抑制作用最为显著。Adsorption of acid phosphatase on yellow brown soil, latosol, kaolinite, goethite and δ-MnO 2 in a series of phosphate solutions different in concentration was investigated. Results showed that, with increase in phosphate concentration, isotherms of phosphatase adsorption on soil colloids and minerals were changing from L type (Langmuir) to C type (linear). The transformation of adsorption isotherm was ascribed to competition between phosphate and enzyme molecules for adsorption sites on soil colloids and minerals. With the increase in phosphate in the system from 0 to 100 mmol L -1, a sharp fall was observed for the amount of enzyme adsorbed. When the concentration came within the range of 100～500 mmol L -1, no remarkable variation of the amount of enzyme adsorbed was observed. The inhibitory effect of phosphate on the adsorption of enzyme was dependent on the surface characteristics of soil colloids and minerals, especially the quantity of hydroxyls, the concentration of phosphate and the amount of enzyme added. The most effect was found in goethite and lateritic colloids which contain more ferri-aluminum hydroxide.

关 键 词：磷酸盐 土壤 胶体 表面吸附 酸性磷酸酶 

分 类 号：S153.3[农业科学—土壤学]