几种粘土矿物和粘粒土壤吸附净化磷素的性能和机理

通过磷素等温吸附实验和磷素饱和吸附后磷素的形态变化，研究了高岭土、蒙脱土、凹凸棒土、蛭石和沸石5种粘土矿物，以及黄褐土和下蜀黄土2种粘粒土壤中磷素的吸附净化性能和机理，结果表明：除高岭土和沸石以外，其它类型的粘土矿物和粘粒土壤均有较好的磷素吸附净化能力，蛭石的磷素吸附净化能力最强，其次为黄褐土、凹凸棒土、蒙脱土和下蜀黄土．粘土矿物和粘粒土壤磷素的吸附能力与其化学组成关系密切，表现为全钙及水溶性钙、胶体氧化铁和胶体氧化铝含量愈多，其磷素的吸附量愈大，磷素的净化能力愈强．此外，粘土矿物和粘粒土壤磷素饱和吸附后的形态转化也受其化学组成的影响，表现为全钙及水溶性钙、胶体氧化铁和胶体氧化铝含量较高，其对应形成的磷酸钙盐、磷酸铁盐和磷酸铝盐含量较高，粘土矿物和粘粒土壤吸附磷素的机制主要为化学吸附，包括专性化学吸附和非专性化学吸附．

THE ABILITIES AND MECHANISMS OF ADSORPTION PHOSPHORUS IN SOME CLAY MINERLS AND SOILS

Clay minerals and soils are important natural resources to be used in all fields including environmental protection. In this paper the abilities and mechanisms of adsorption phosphorus in five clay minerals and two clay soils were studied through experiments on Langmuir adsorption isotherms of phosphorus and analyzing the contents of different type of phosphorus in these materials saturated with phosphorus. Clay minerals and soils had a better performance on removal of phosphorus except kaolinite and zeolite. Vermiculite had a stronger ability of adsorption phosphorus, followed by yellow cinnamon soil, attapulgite, bentonite and xiashu loess. The ability of adsorption phosphorus of these materials was mainly influenced by their composition such as reactive Ca, Fe and Al, so the reactive Ca, Fe and Al can significantly improve the ability of adsorption phosphorus in these materials. The different type of phosphorus in these materials saturated with phosphorus had also closely relationship with their makeup such as total Ca, reactive Ca, Fe, Al. Among these materials including clay minerals and soils saturated with phosphorus in this study, the materials with higher total Ca and reactive Ca had higher calcium phosphate, for the ferric phosphorus and aluminum phosphorus, there were the same trend like this. The clay minerals and soils adsorbed phosphorus through chemical process including specific adsorption and nonspecific adsorption.