南方酸沉降区土壤硫酸根吸附解吸特性及其数值拟合

通过8种典型土样的硫酸根吸附解吸实验，研究了我国南方土壤硫酸根的吸附解吸特性，并运用Freundlich、Langmuir和Temkin等温方程对试验数据进行了拟合，结果表明，Freundlich方程和Langmuir方程对土壤硫酸根吸附过程拟合较好，Temkin方程则不太适合，但上述方程对硫酸根解吸过程拟合结果均较差，土壤硫酸根的解吸不是吸附的简单逆过程，而纯矿物对硫酸根的吸附解吸过程均可用上述3个方程拟合，且相关系数均在0.9以上，南方土壤中，蒙脱石的存在对硫酸根的吸附可能起特殊的促进作用。

Modeling Sulfate Adsorption_Desorption Processby Soils in South China with Isotherms

The properties of sulfate adsorption-desorption by soils in South China was studied by means of equilibrium test. Eight soils collected from four provinces were tested. Na 2SO 4 was added in a series of nine concentrations as adsorption solution, while deionized water, NaNO 3 and NaH 2PO 4 were used as desorption solution. The data were modeled with three sorts of isotherms, namely Freundlich, Langmuir and Temkin isotherms. It was found that Freundlich and Langmuir adsorption isotherms were fit to the data of sulfate adsorption by soils with high coefficient, while Temkin isotherm was not fit well yet. But none of the three isotherms was fit to the data of sulfate desorption by soils. The results indicate that the capacity of sulfate adsorption and the firmness of sulfate adsorption by soils is decided by soil properties, especially the soil components, and that the desorption is not the simply reverse process of adsorption. As to the pure minerals, the three isotherms were all fit well to the data of sulfate adsorption and desorption.