One of the great challenges in environmental research today is to find tolerant species of plants and microsymbionts to make viable the revegetation of contaminated areas with heavy metals. This experiment was carried out under greenhouse conditions at the Soil Science Department of the Federal University of Lavras (MG), from August to December 1998, to assess the tolerance to heavy metals and the capacity to establish rhizobia symbiosis with Enterolobium contortisiliquum (tamboril), Acacia mangium (acacia) and Sesbania virgata (sesbânia) in […]

Total soil lead (Pb) content along with the sorption capacity of Pb in soils are important parameters for risk assessment studies of Pb in the environment. This experiment used A-horizon samples of 17 Oxisols from all Brazilian regions to evaluate their total Pb content as well as their Pb maximum adsorption capacities (PbMAC). The total soil Pb content varied from 6.14 to 30.55 mg kg-1, averaging 18.00 mg kg-1. The highest total soil Pb contents were found for soils of the southern and southeastern regions, […]

Cadmium may be added to the soils through tire residues, oils, urban waste, sewage sludge and phosphated fertilizers. It is easily absorbed and translocated by plants and can potentially harm human health. The objectives of this work were to study cadmium adsorption in surface and subsurface horizons of two highly weathered soils with different textures: Anionic “Rhodic” Acrudox (RA) and Anionic “Xanthic” Acrudox (XA), representing extreme conditions in the scale of weathering and exhibiting a predominant balance of positive charge […]

Adsorption-desorption reactions of lead in soils are affected by surface chemistry and solution composition. This study evaluated the effect of pH upon lead adsorption-desorption by A-horizon samples of Brazilian Oxisols. Soil suspension was previously titrated with either 7 mmol HNO3 or saturated Ca(OH)2 to determine the amount of acid or base necessary for pH adjustment. The effect of pH on Pb adsorption was evaluated after a 72 h-reaction of the soil samples with 0.15 mmol L-1 Pb(NO3)2 at pH 4.5, 5.5, and 6.5, using […]

Although widely reported, studies on chemical forms and concentrations of heavy metals in polluted soils and their effects upon ecosystems are still not much emphasized in the tropics. The present study was developed in a waste area of a zinc processing industry owned by the Companhia Mineira de Metais-CMM at Três Marias (MG), Brazil, to evaluate heavy metal quantities and forms in seven representative sites, selected according to differences in form of contamination, pedological aspects, topography and current vegetation status. […]

Air dried subsurface samples of a heavy textured Red-Yellow Podzolic soil, representative of the industrial solid residue pilot landfill (ISRL) of the National Steel Works (Companhia Siderúrgica Nacional-CSN), were packed in 5.4 cm width and 37 cm high glass columns. An acid iron smelter residue was placed on the top of the soil columns to make a 4:1 soil-residue ratio, in consonance with the basic CSN project. To evaluate Cr, Mn, Ni, Cu, Zn, Cd and Pb mobilities, the system […]