【摘要】 金属离子与土壤黏粒之间的相互作用决定了金属离子在土壤中的移动性和生物有效性等,一直是土壤化学研究的重点之一。近年来,基于悬液Wien效应发展了一种测定离子与土壤黏粒之间能量关系的新方法,相较以往基于吸附等温线或者离子活度计算离子与土壤黏粒之间能量关系的方法,悬液Wien效应方法具有测定简便、能够直接计算能量等优点。悬液Wien效应是指悬液电导随场强增加而增加的现象,从悬液Wien效应原理、仪器设备研发、悬液Wien效应应用等角度综述了过去10多年的主要研究进展。发现不同价态的离子在土壤黏粒上的结合能和吸附能不同,主要表现为二价>一价;由于三价离子(Cr³⁺和La³⁺)易于水解,三价离子的结合能和吸附能小于二价离子;相同离子在不同土壤类型上的结合能和吸附能表现出不同差异,与土壤性质如土壤有机质和土壤氧化铁含量有关。研究结果推动了传统土壤化学关于金属离子非专性吸附机理的认识,在理论和方法学方面深化了土壤学的基础研究内容。更多还原

【Abstract】 The interaction between ions and soil particles plays an important role in the mobilization and bioavailability of ions in soils,which is one of the main research areas of soil chemistry. The new method based on suspension Wien effect has been developed recently to determine the binding energy and adsorption energy between ions and soil particles. Compared with other methods on the basis of adsorption isotherm or ions activity,Wien effect method has more advantages including convenience and direct measurement. The term suspension Wien effect refers to the increase of electrical conductivity of suspension with increasing applied electrical field. In this review paper,we introduced the fundamentals of suspension Wien effect,the apparatus about the Wien effect measurement,and along with demonstrating their application to quantifying the particles-ions interactions for several systems of soils. Our studies indicated that divalent cations have larger binding energies and adsorption energies on soil particles than monovalent because of the electrostatic interaction. However,few studies about the interaction between Cr³⁺and La³⁺on soil particles showed that the binding energy and adsorption energy of trivalent cations are lower than those of divalent cations because of hydrolysis. Soil properties such as soil organic matter,soil p H,and iron oxides significantly affected the binding energy and adsorption energy of ions. Our results deepened our understanding about the non-specific adsorption of ions in soil chemistry,and enlarged the research area of soil chemistry in fundamental and methodology.更多还原