【摘要】 供试三种不同土壤溶解态胡敏酸（HA）与Cu2+络合的稳定常数logK大小呈：黑垆土HA＞土HA＞黄绵土HA，logK的大小与pH、温度（T）及离子强度（I）有关；络合反应的热力学函数变化：标准自由能变△rGmθ＜0，标准焓变△rHmθ＜0，标准熵变△rSmθ＜0，表明络合是自发的放热反应，体系有序性增大。△rSmθ负值大小与logK呈相同次序，称为HA络合Cu2+过程中HA分子变形及络合物稳定性的熵效应。不同土壤非溶解态HA对Cu2+的吸附等温线可用Freundiich方程，单表面Langmuir方程及双表面Langmuir方程描述。吸附过程热力学函数变化：标准自由能变△Gmθ＜0，标准焓变△Hmθ＜0，标准嫡变△Smθ＞0，表明吸附是自发、放热、混乱度增大的过程，△Smθ值的大小可表征Cu2+在HA表面的熵状态，HA对Cu2+的吸附结构类似于扩散双电层结构。络合反应与吸附过程特征比较，其差异与二者的结合机制不同密切相关。更多还原

【Abstract】 Stability constant logK, which tested three kinds of soil soluble humic acids reacted with copper ion to form the complexes, appeared in the following tendency;darkcultivated loessal soil＞old manured loessal soil＞yellow loessal soil. logK value was related to pH,temperature and ionic strength. The thermodynamic function variations in complexation were :△rGm θ＜0,△rHm θ＜0, and △rSmθ＜0, showing that the complexation reaction was a spontaneous exothermic reaction and that negative value of △rSm＜0 was in the same sequence with logK, wich was considered as the entropy effect of humic acid molecular deformation and complex stability in process of humic acid reaction with copper ion. Freundlich equation, single surface hangmuir equation and double surface Langminrequation were used to describe copper ion adsorption isotherms of different soil insoluble hamic acids. Thermodynamic function variations in adsorption process were; △Gmθ＜0, △Hmθ＜0, and △Smθ＞0, suggesting that adsorption was a spontaneous, exothermic and increasingly confused process. △Smθ value could characterize the　entropy state of copper ion at surface of humic acid. Structure of copper ion adsorption at humic acid surface was similar to the diffuse electric double layer structure.The differences of characteristics between adsorption and complexation were closely related to their different compound mechanisms.更多还原