Abstract:Isothermal absorption, kinetic absorption and desorption process of antimony [Sb(V)] in red soil and calcareous soil typical to South China were studied. Commonly used adsorption kinetics equations were compared in fitting of dynamic adsorption curves. Sb(V) binding forms in the soils were analyzed using the sequential extraction method. Results show that the acid red soil was higher than the brown calcareous soil in both Sb(V) adsorption capacity (being 13.83 μmol g-1 and 9.19 μmol g-1, respectively) and Sb(V) adsorption rate (being 0.58 μmol g-1 h-1 and 0.38 μmol g-1 h-1, respectively); the Sb(V) adsorption on the surface of the red soil is a rapid and irreversible process; Antimony found in the two soils was mainly in Fe-Al oxides bound form and residue form; the content of specific or non-specific adsorption form of Sb(V) was quite low, which indicates that the adsorption of antimony in the soils is mainly irreversible. The comparison of the four adsoprtion kinetics equations in fitting of the experimental results shows that for red soil, high in Sb(V) concentration, the Elovich equation (R2=0.96) fitted the best and for red soil, low in Sb(V) concentration, the pseudo-second order kinetics equation did the best (R2=0.97、1.00), while for brown calcareous soil, regardless of Sb(V) concentration, the double constant equation (R2=0.96、0.94、0.93) fitted the best.