黑土和棕壤对铜的吸附研究

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Cu^2+浓度范围内，黑土和棕壤对CU^2+的吸附量均随着加入Cu^2+浓度的增加而增加，但黑土对cu^2+的吸附固定能力明显高于棕壤．在吸附平衡液Cu^2+浓度为95mg·kg^-时，棕壤对cu^2+的吸附量接近3720mg·kg^-1，黑土对Cu^2+的吸附量高达6076mg·kg^-1，最大CuCl2浓度(400mg·kg^-1)时，黑土和棕壤对Cu^2+的吸附量分别达到6159．0和4736．6mg·kg^-1．两种土壤对Cu^2+的吸财等量线与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Cu^2+的等温吸附过程．黑土和棕壤对Cu^2+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。

Cu adsorption by phaeozem and burazem

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 95 mg.kg-1, its adsorption by burozem was nearly 3720 mg.kg-1, whereas by phaeozem was as high as 6076 mg.kg-1. Under the highest CuCl2 treatment of 400 mg.kg-1, Cu2+ adsorbed by phaeozem and burozem was 6159.0 mg.kg-1 and 4736.6 mg.kg-1, respectively. The adsorption of Cu2+ by the test 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.