红壤粘粒对Co、Cu、Pb和Zn吸附亲和力的研究

本文研究了高度风化的酸性红壤对Ｃｏ，Ｃｕ，Ｐｂ，Ｚｎ离子的吸附特性。用吸附曲线形状，吸附方程，分配系数，ｐＨ５０值等讨论了吸附亲和力特征及其影响因素和吸附反应的机理。结果表明，红壤粘粒吸附重金属离子主要由Ｆｅ，Ａｌ氧化物所控制。金属离子对红壤粘粒的吸附亲和力（以ｐＨ５０表示）主要决定于离子本化学性质，亲和力以Ｃｕ≥Ｐｂ＞Ｚｎ＞Ｃｏ顺序减少，易水解的离子吸附亲和力较大，亲和力也受土壤组分及其表面性质

STUDY ON ADDORPTION AFFINITIES OF Co, Cu,Pb AND Zn FOR DIFFERENT RED SOIL CLAYS

An experiment on the characteristics of Co, Cu, Pb and Zn adsorption by seven highly weathered acid soils derived from different parent materials in different areas of southern China was conducted to study affinity characteristics and factors affecting affinity as well as the mechanism of adsorption reaction by using shapes of adsorption curve, pH values and competitive adsorption equations and distribution coeffieients. Clay fractions(< 11tm) separated from red soils with different properties were allowed to react with solutions of Co, Cu, Pb and Zn in 25 ml 0.05 mol/L Ca(NO₃)₂ as supporting electrolyte containing the desired amount of adsorbate ion, respectively. The pH values of suspention were adjusted by adding appropriate amounts of 0.1 mol/L N0₃ or saturated Ca(OH)₂ solution prior to metal addition to obtain a series of suspentions with various pH values.