The presence of organic ligands in the rhizosphere plays an important role in heavy metal solubilization in soils treated with sewage sludge. Low molecular weight organic acids exuded by roots and/or released by microorganisms are considered mobilizing agents of these metals. The present study determined Cd, Cu, Cr, Ni, and Zn solubilization kinetics in sewage sludge-treated soils using a mixture of four organic acids (acetic, citric, lactic, and oxalic) in 0.05 and 0.10 mol L-1 solutions. Based on the batch extraction method […]

This study carried out in order to evaluate the effect of sewage sludge (from Barueri: industrial and residential sewage, and Franca (SP) State: residential sewage) doses on soil heavy metal contents and their availability to corn. Three successive experiments were installed in a Latosol at the Experimental Field of Embrapa Environment, in Jaguariúna (SP), from 1999 to 2001. The treatments investigated consisted of: control (without sewage sludge); mineral fertilization (NPK) recommended for corn; and application of both sewage sludge sources […]