Abstract:
Three kinds of soil samples with different texture were sieved into nature fraction, sandsized fraction and silt and claysized fraction. Adsorption characteristics of these three different sized fractions of three different soils for Cd, Pb and Hg were studied. The results showed that adsorption capacity of Cd and Pb by silt and claysized fraction was higher than that by two other fractions. However, adsorption capacity of Hg showed opposite result to Cd and Pb, which was far higher by sand fraction than that by nature and silt and clayfraction. And the adsorption for Cd, Pb and Hg by three kinds of soils with three different sizes showed the similar characteristics. Furthermore, the Langmuir equation was proved to be the best description for Cd adsorption by different soils, the Henry equation was suitable for the description of Pb adsorption by different soils and the Freundlich equation could better fit the experimental data of Hg adsorption by three different soils.