灰棕紫泥对锌的吸附

经DTPA预处理的灰棕紫泥土壤,在2—32ppm锌浓度范围内都能很好地遵从Langmuir吸附方程,其拟合线性关系很好(r=0.988~(**));未作预处理的土样虽也能较好地遵从Langmuir方程(r=0.947~(**)),但所适应的锌浓度范围变窄,为4—32ppm,且其吸附等温线分为两部分,只有后面主要一段才符合该方程。求取了方程重要参数b和k,预处理土样分别为0.078m.e./g±(=7.8m.e./100g±)和11;未预处理土样则分别为0.076m.e./g±(=7.6m.e./100g±)和10。经分析,在相同平衡溶液浓度条件下,两种土样在对锌的吸附方面显著相关(r=0.99~(**))。在探讨农耕土壤吸附锌的特征时,似以对土样进行预处理为优,而且本研究所用预处理程序并不影响原土类的主要吸附特征。

THE ADSORPTION OF Zn BY GRAY-BROWN PURPLE SOIL

The adsorption of Zn by the gray-brown purple soil treated with DTPA solution comforms to the Langmuir isotherm, at the range of Zn concentration from 2 to 32 ppm, and the fitting linear correlation is very significant: for the untreated gray-brown purple soil, only one of all the two parts of the curve fairly-well comforms to the Langmuir equation, the appropriate range of Zn concentration becomes narrow, from 4 to 32 ppm. The equation parameters, the maximum amount of absorbate 6 and the constant related to the binding strength K, are 0.078m. e./gsoil(=7.8 m.e./100g soil)and 11, respectively for the treated soil sample: 0.076 m.e./g soil(=7.6 m. e./100g soil) and 10, respectively for the untreated soil sample. There is a significant correlation between the two soil samples (r=0.99~(**))in the Zn adsorption amount, under the conditions of the same equilibrium solution concentration. It seems to be better to pretreat the soil samples when the process of Zn adsorption by the agricultural soil is to be studied, and the pretreatment procedure used here does not affect the important adsorption properties of the initial soil.