Adsorption of zinc by alkaline soils was studied in the presence of 0.05M CaCl2. The amount of adsorbed zinc increased with the concentration of applied zinc. Freundlich and Temkin equations were tested to describe the adsorption. The latter gave a better fit as compared with the Freundlich equation at low levels (0.15 to 1 ppm) of zinc application. The nature of adsorption reaction was found to be similar in all the four soils. The Freundlich constants of these soils (for zinc) have also been derived. At these low levels of applied zinc, the soil system remains generally unsaturated with respect to Zn(OH)2.
Zinc adsorption, alkaline soils, Freundlich and Temkin equations
