Heavy metals are found naturally in soils at low concentrations, but their content may be increased by human activity, making them one of the barriers in management of tropical soils. These chemical elements can be found in the composition of organic and inorganic fertilizers, insecticides, fungicides, mine tailings, and urban waste, and may cause serious damage to the environment and human health. Thus, adsorption studies are essential in assessing the behavior of heavy metals in the soil. The objective of […]

The use of plants for phytoremediation of metal-contaminated areas is an emerging technology, and studies concerning heavy metal tolerance, absorption and distribution in plants are essential for the success of such programs. This study was carried out to evaluate the tolerance, absorption and distribution of lead (Pb) in vetiver grass [Vetiveria zizanioides (L.) Nash], mimosa [Desmanthus virgatus (L.) Willd] and mesquite trees [Prosopis juliflora (SW) DC] subjected to increasing lead doses in solution. The experiment was conducted under a screenhouse, […]

As a result of anthropogenic activities such as mining, metal industry and agricultural fertilizer application, metal pollution has become one of the most serious environmental problems of today. Phytoremediation denotes the use of plants and micro-biota, together or without soil amendments, to extract, sequester, and/or detoxify pollutants, has been reported to be an effective, non-destructive, inexpensive and socially accepted technique to remediate polluted soils. The objective of this work was to evaluate the efficiency of organic amendments in the reduction […]

The application of sewage sludge into agricultural soils, as organic fertilizer or soil conditioner, is becoming an increasingly more attractive alternative. It is occurring because of the high costs and environmental impacts caused by other sludge disposal methods, besides the presence of plant nutrients and organic matter in the sludge and the need to reduce costs in agriculture. However, sewage sludge can contain heavy metals, pathogenic microorganisms, and toxic organic compounds. In order to study the impact of sewage sludge […]

The movement of nitrate in soil percolate was evaluated in a field experiment using a Typic Hapludox cultivated with sugarcane and amended with urban compost waste or inorganic fertilizer. The experiment, conducted during the years of 1996/97 and 1997/98, had the following treatments: lime + inorganic fertilization, and control and urban compost waste applied in three levels: 20, 40 and 60 Mg ha-1 (dry weight basis). In the second year (1997/98), the urban compost waste was applied to soil in […]

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 […]