可变电荷土壤和恒电荷土壤与氢离子的反应动力学

在研究可变电荷土壤和恒电荷土壤与H+的反应动力学中,重点考察了H⁺、表面正电荷和可溶性铝随时间变化的特征及影响因素.结果表明,1类土壤中H⁺消耗都可分快速反应和慢速反应2个阶段,但其具体表现和影响因素不同;因氧化铁含量不同,H⁺加入后2类土壤表面正电荷变化存在明显差异;可溶性铝随时间的变化主要受土壤粘土矿物组成、溶解度及溶解动力学控制;2类土壤的可溶性铝的变化可同时用修正的Elovich方程和双常数速率方程描述.

Kinetics of Interaction of H+ with Constant and Variable Charge Soils

The kinetics of interaction of H⁺ ions with constant and variable charge soils were studied,among which changes of H⁺ concentration, positive surface charge and soluble Al with time and their influencing factors were investigated in detail. The results showed that the consumption processes of H⁺ ions in both constant and variable charge soils could be divided into fast and slow processes, but the manifestations and influencing factors were different for the two types of soils. The variations in positive surface charges for variable and constant charge soils, due to the difference in the contents of free Fe-oxides, are remarkably different and thus can not be modeled mathematically in the same manner for the two types of soils. The variations in soluble Al for both variable and constant charge soils were controlled by the components, solubility and solution kinetics of dominant clay minerals in soils, and could be described by both modified Elovich and two-constant rate equations mathematically.