无机阴离子对镉、铅解吸特性的影响

Effects of inorganic anions on the desorption character of cadmium, lead

土壤中重金属的解吸直接影响重金属在环境中的形态转化和植物有效性。而地表水环境及土壤中的无机阴离子能与重金属离子络合,影响重金属在环境中的迁移和作物的吸收。因此,有关无机阴离子对重金属解吸特性影响的研究,将有利于了解重金属的吸附-解吸机制及其控制措施。文章以我国东北地区草甸棕壤作为研究对象,采用静态解吸实验研究无机阴离子(C1-、SO42-、F-)对土壤中镉、铅的解吸行为的影响。结果表明,土壤中镉、铅的解吸率与无机阴离子类型、浓度密切相关;随着解吸液中无机阴离子(C1-、SO42-、F-)浓度的增大,土壤镉、铅的解吸率随之提高。C1-、SO42-、F-这3种无机阴离子对解吸土壤中镉的影响力顺序是:C1->SO42->F-;对解吸土壤中铅的影响力顺序是:SO42->C1->F-。

Desorption of heavy metals from soils has direct influence on the speciation transform and phytoavailability of heavy metals in the environment. While inorganic anions in surface water environment and soils could combine with heavy metal ions, and have influences on the transference of heavy metals in environment and the assimilation by crops. So study the influences of inorganic anions on desorption character of heavy metals would have better understand on the sorption-desorption mechanism and control methods. In the paper meadow brown soil in northeast China was picked up as the study object, through the static state desorption experiment, effects of inorganic anions （Cl^-、SO4^2-、F^-） on the desorption character of Cd and Pb were carded out. Results showed that the desorption rate of Cd, Pb had close relationship with the type and concentration of inorganic anion. With the rising concentration of inorganic anions （Cl^-、SO4^2-、F^-）, the desorption rate of Cd and Pb also increased. The influence capacity of the three inorganic anions followed as Cl^-〉SO4^2-〉F^- for Cd. As for Pb, the influence capacity of inorganic anions followed as Cl^-〉SO4^2-〉F^-.