重金属汞在土壤中的吸附解吸特性研究

Research on Adsorption and Desorption Characteristics of Mercury in Soil

为充分了解重金属汞在土壤中吸附解吸特征,运用振荡平衡法对重庆市秀山地区某汞污染企业周边背景土壤进行Hg2+的吸附解吸实验,探究土壤中汞的等温吸附解吸过程及吸附动力学特征。结果表明:Langmuir模型对汞在土壤中的等温吸附过程拟合效果最好(相关系数为0.999 2),供试土壤对汞的最大吸附量为863.62mg/kg;Freundlich模型能更好地拟合汞在土壤中的解吸过程(相关系数为0.981 1),汞的最大解吸量为16.840 7mg/kg,汞在土壤中的解吸率较低,最大解吸率仅为3.65%;Elovich模型和双常数模型对汞在土壤中的吸附动力学过程模拟能够达到较显著水平,相关系数分别达到0.893 5和0.837 0。

Batch equilibrium method was applied to fully understand characteristics of adsorption and desorption of mercury in soil collected from background area surrounding a company with mercury pollution in Xiushan region, Chongqing. The isothermal adsorption and desorption process and kinetics of adsorption were studied. The results showed that the l_angmuir model fits well with the isothermal adsorption of mercury in soil, the correlation coefficient is 0. 999 2 and the saturated adsorption capacity is 863.62mg/kg. The Freundlich model could better fit the desorption process of mercury, the correlation coefficient is O. 981 1 and the maximum desorption capacity is 16. 840 7mg/kg. The desorption rate of mercury in soil was relatively low, with maximum desorption rate of 3.65%. The simulation of Elovich model and double - constant model on kinetics of adsorption of mercury in soil reached the significant level, with correlation coefficient of 0. 893 5 and 0. 837 0, respectively.