四川盆西平原区裸土扬尘中Pb、Cd化学形态的生物有效性

Bio-availability of chemical species with Pb and Cd contained in flying soil dust in west plains of Sichuan

为探究四川盆西平原区裸土扬尘中Pb、Cd总质量分数与其生物有效性的规律,在构建的“阳离子型污染物土壤表层运移行为研究系统”内进行模拟起尘试验,对土壤样品进行Pb、Cd模拟污染试验,结果表明:试验条件下,四川盆西平原区裸土扬尘颗粒物中Pb、Cd的总质量分数随着粒径的减小而增大,其中Pb的化学形态以碳酸盐结合态为主(44.34%~57.39%),而Cd的化学形态则以可交换态(49.17%~53.30%)和碳酸盐结合态(33.95%~37.56%)为主;Cd的生物有效性高于Pb的生物有效性,Pb、Cd的生物有效性均随着扬尘颗粒物粒径的减小而增大。

To study the total content of Pb and Cd contained in the flying soil dust and its bio-availability in the west plains of Sichuan,the simulated dusting experiment was carried out in a cationic polluted soil migration system,together with the simulation test on soil sample to be contaminated with Pb and Cd.The results show that under the experimental conditions,the total content of Pb and Cd contained in the flying soil dust particles in west plains of Sichuan will increase with the decrease of the particle size.The chemical species of Pb contained in soil dust particles are composed mainly(44.34%-57.39%)of carbonate binding state,while the chemical species of Cd contained in soil dusting particles are composed mainly(49.17%-53.30%)of exchanging state and(33.95%-37.56%)of carbonate binding state.In addition,the bio-availability of Cd is higher than Pb.The bio-availability of heavy metals such as Pb and Cd increases with the decrease of the particle size of the flying soil dust in west plains of Sichuan.