STUDY ON THE CD (II) ADSORPTION CHARACTERISTICS OF DIFFERENT SALINE-ALKALINE SOILS IN WESTERN JILIN PROVINCE, CHINA

In order to effectively control the environmental behavior of cadmium in saline-alkaline soil, it is imperative to understand its adsorption capacity. In this study, the kinetics, adsorption isotherm and two environmental parameters (pH and addition of biochar) of the adsorption behavior of Cd (II) in three saline-alkaline soil samples from western Jilin province, China were investigated. This study was an optimal fit for the pseudo-second-order kinetics model, as well as Langmuir adsorption isotherm model. The adsorption effect was the strongest at a pH of 7, the addition of biochar could increase Cd (II) adsorption of the soil. The adsorption of Cd (II) by saline-alkaline soil was a spontaneous, disordered and heat-absorbing reaction. Compared with mildly and moderately saline-alkaline soil, the adsorption of Cd (II) by severely saline-alkaline soil was the highest, and the adsorption was the best when the pH was neutral. Moreover, the addition of biochar could increase the organic matter in the soil and improve the adsorption capacity of Cd (II).