Studies of the effectiveness of Cu2plus, Co2plus and Cr3plus desorption with Kplus in grey-brown podzolic soils

Model studies were carried out using the three-component CuCl2, CoCl2 and CrCl3 solution in two greybrown podzolic soils. After saturation of soil with the three-component solution and elution with water, desorption was carried out with the 0.1 mol dm-3 KCl solution. For comparison, desorption with the NH4Cl, CaCl2 and MgCl2 solutions was also conducted. Desorption of Cu2+ with K+ was in both soils similar to that of NH4 + and Mg2+ but smaller in comparison with Ca2+. In the case of Co2+ desorption with the studied exchangeable cations was not differentiated. Desorption of Cr3+ with K+ and NH4 + was greater than with Ca2+ and Mg2+. The differences in desorption efficiency can be explained based on the theory of hard and soft acids and bases (HSAB).