Simulation experiment of the geochemical behavior of Hg in soils—A case study of typical soils in Shanxi, China

Soil samples were taken from Datong, Taiyuan and Linfen. The experiment comprised two parts: adsorption-desorption and transport experiment. Soils for the adsorption experiment were sieved into the sand-sized fraction and clay-sized fraction. The main results indicate that the amount of Hg absorbed by the three kinds of soil increased with increasing equilibrium concentration of Hg ion solution. The adsorption of Hg by the three types of soil was fitted by four adsorption models at normal temperature and pressure, of which the Freundlich mode and Langmuir model can better fit the experimental data of Hg adsorption by the three kinds of soil, all of which have a certain retaining and fixation effect on Hg. The soils in order of decreasing desorption rates are the Datong soil, Linfen soil and Taiyuan soil. When the concentration of Hg2+ is 300 mg/L, the rate of Hg penetration through the Datong soil is highest and that through the Taiyuan soil is lowest. Consequently the authors conclude that Hg2+ is transported most rapidly in loamy sand and most slowly in silty loam.