黑土和棕壤对铜的吸附研究

摘要/Abstract

摘要： 研究了黑土与棕壤对Cu吸附的热力学和动力学特性.结果表明,在实验所采用Cu²⁺浓度范围内,黑土和棕壤对Cu²⁺的吸附量均随着加入Cu²⁺浓度的增加而增加,但黑土对Cu²⁺的吸附固定能力明显高于棕壤.在吸附平衡液Cu²⁺浓度为95mg·kg^-1时,棕壤对Cu²⁺的吸附量接近3720mg·kg^-1,黑土对Cu²⁺的吸附量高达6076mg·kg^-1,最大CuCl2浓度(400mg·kg^-1)时,黑土和棕壤对Cu²⁺的吸附量分别达到6159.0和4736.6mg·kg^-1.两种土壤对Cu²⁺的吸附等温线与Freundlich和Temkin方程均有较好的拟合性,可以用Freundlich方程对其吸附行为进行描述.Langmuir方程不适宜描述两种土壤对Cu²⁺的等温吸附过程.黑土和棕壤对Cu²⁺的吸附均较快,最初2min内就可以达到平衡后吸附量的90%以上,在15～20min左右吸附基本达到平衡.描述黑土和棕壤动力学过程的最优模型为双常数速率方程,其次为一级动力学方程和Elovich方程.

关键词: 侧柏, 水分利用效率(WUE), 季节变化, 铜, 黑土, 棕壤, 吸附作用, 热力学, 化学动力学, 影响贡献率

Abstract: Studies on the thermodynamics and kinetics of copper (Cu²⁺) adsorption by phaeozem and burozem showed that that the adsorption of Cu²⁺ by these two soils was increased with the increasing concentration of Cu²⁺ within the range of Cu²⁺ concentrations used in the experiment, but the amount of Cu²⁺ adsorbed and fixed on phaeozem was much higher than that on burozem. When the test Cu²⁺ concentration in adsorption equilibrium was 95mg·kg^-1,its adsorption by burozem was nearly 3720mg·kg^-1, whereas by phaeozem was as high as 6076mg·kg^-1 . Under the highest CuCl₂ treatment of 400mg·kg^-1, Cu²⁺ adsorbed by phaeozem and burozem was 6159.0mg·kg^-1 and 4736.6mg·kg^-1,respectively .The adsorption of Cu²⁺ by the soils could significantly conform to the Freundlich and Temkin equation,while Langmuir equation was not applicable to describe the isothermal adsorption processes of Cu²⁺ by the two soils. The adsorption of Cu²⁺ by the test soils was very rapid, which could reach its balance after 15～20 min. The adsorption within the first 2 min at its beginning stage accounted for 90% of the Cu equilibrium adsorption. The adsorptive rate of Cu²⁺ by phaeozem was decreased more quickly than that by burozem with the time. The two constant equation was the optimal model to describe the adsorption of Cu²⁺ . The other models in point were first order dynamic equations and Elovich equations, whereas parabolic diffusion equations were not suitable ones.

Key words: seasonal variation, impact contribution rate, water use efficiency (WUE), Cu, Phaeozem, Burozem, Adsorption, Thermodynamics, Chemical kinetics, Platycladus orientalis

于颖, 周启星, 王新, 任丽萍. 黑土和棕壤对铜的吸附研究[J]. 应用生态学报, 2003, (5): 761-765.

YU Ying, ZHOU Qixing, WANG Xin, REN Liping. Cu adsorption by phaeozem and burazem[J]. Chinese Journal of Applied Ecology, 2003, (5): 761-765.

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