Adsorção de cádmio em Latossolos sob vegetação de mata nativa e cultivados

• Autor(a) principal: Soares Reis, Iolanda Maria
• Data de Publicação: 2014
• Outros Autores: Melo, Wanderley Jose de [UNESP], Marques Junior, Jose [UNESP], Ferraudo, Antonio Sergio [UNESP], Peruca de Melo, Gabriel Mauricio
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832014000600030; http://hdl.handle.net/11449/180755
• topic: Adsorption isotherms; Pollution; Heavy metal availability; Langmuir; Freundlich; Isoterma; Poluição; Disponibilidade; Langmuir; Freundlich

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 this study was to evaluate the influence of soil chemical, particle size, and mineralogical properties on adsorption of cadmium (Cd), evaluated by Langmuir and Freundlich models, in Latossolos (Oxisols) with or without human activity. Soil samples were collected from the surface layer, 0.00-0.20 m, and chemical, particle size, and mineralogical analyzes were performed. In the adsorption study, concentrations of 0, 5, 25, 50, 100, 200, 300, and 400 mu g L-1 of Cd were used in the form of Cd(NO3)(2). The empirical mathematical models of Langmuir and Freundlich were used for construction of adsorption isotherms. Data were analyzed by means of multivariate statistical techniques, Cluster Analysis and Principal Component Analysis. The data from the adsorption experiment showed a good fit to the Langmuir and Freundlich models. Soils with a lower goethite/hematite ratio and greater cation exchange capacity and pH, showed higher maximum adsorption capacity of Cd.