锑在不同土壤中的解吸行为比较

对锑(Sb)在黑土、红壤和褐土3种土壤中的解吸行为进行了比较研究。结果表明,Sb在3种土壤中的解吸过程是一个快速反应的过程,解吸反应在30 min左右基本完成,吸附态Sb的解吸量能达到最大解吸量的95%以上。Sb在3种土壤中的解吸率都比较低,相对于总吸附量而言,Sb在黑土、红壤和褐土中的解吸百分比分别低于17.1%、20.6%和26.23%。3种土壤吸附态Sb的解吸速率随Sb初始浓度的增加而增加,并随着解吸量的增加和解吸时间的延长而不断降低。Sb在3种土壤中解吸的动力学最优模型是:黑土和红壤为Elovich方程,褐土为双常数方程。这对探明土壤中锑的环境行为和风险具有重要意义。

A Comparison of Desorption Behaviors of Sb in Different Soils

The bioavailability and movement of antimony(Sb) in soils is dependent on its desorption behaviors. In the present study, desorption of Sb in three different soils were comparatively investigated. Results indicated that desorption of Sb in three soils was very rapid, and finished 95% of the maximum desorption within the first 30 min. However, the desorption percentages of adsorbed Sb were relatively low, accounting for 19.1%, 20.6%, and 23.2% of total adsorption in chernozem soil, krasnozem soil, and cinnamon soil, respectively. The desorption rates of adsorbed Sb increased with increases in initial Sb concentrations, but decreased as desorption amount and time increased in these three soils. The desorption kinetics of Sb could be well described by the Elovich equation for chernozem soil and krasnozem soil, while fit the two constant equation for cinnamon soil. These results provide valuable information for environmental fates and risks of Sb in soils.