Abstract:Lower the alternating wet and dry conditions with pH 5.0,the mixed solutions of FeSO4 and MnCl2 with different concentrations (0.00-0.08 mol/L) were added to yellow-brown soil columns with soil profile layer B leaching 60 times from the Xiaogan City,Hubei Province.The leaching and deposition of iron-manganese oxides of different forms and its adsorption and desorption characteristics on Pb2+ were investigated.The results showed that the manganese oxide content of the soil surface showed an increasing trend with the increase of leaching solution of manganese concentration,and the iron oxide content did not change obviously when the concentration of Fe2+ in the leaching solution was 0.04 mol/L and 0.08 mol/L.The deposition amount of free and amorphous iron oxides indicators was higher than that of manganese oxides in the soil surface,mostly upper layer (0-10 cm)>lower layer (20-30 cm) lower the same treatment.The adsorption quantities of Pb2+ in the soil samples after leaching 60 times increased with the increase of equilibrium concentration.The maximum of adsorption in upper layer and lower layer was 167 mmol/kg and 195 mmol/kg,respectively.The adsorption quantities of Pb2+ in the yellow-brown soil samples increased with the increase of the amount of manganese deposition.However,the desorption of Pb2+ showed the opposite trend.The trend of Pb2+ desorption quantities increased with the increase of Pb2+ adsorption quantities.