Avaliação da contaminação de solo com cádmio e níquel provenientes de baterias Ni-Cd

• Autor(a) principal: Martinelli, Armando Cozer
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/4691
• topic: Solo - Poluição; Baterias; Metais; Poluição; Cádmio; Níquel; Química; 54

Theimproper disposal ofbatteriesin garbage dumpscan compromise the qualityof ecosystems.The main problem associated with soil contamination by metals is due to the existence of bioavailable forms of these elements. In this context, in the present study, we evaluated the soil contamination with cadmium and nickelfrom spent Ni-Cd batteries. During two years were performed leaching tests in two soil columns: in one was added solublesalts of cadmium and nickel (column A) while in another was added a Ni-Cd battery (column B). The soil sample, collected in Grande Vitória -ES, was manually disaggregated, air dried and passed through a 2mm sieve mesh. The soil characterization by X-ray diffraction (XRD), Mössbauerspectroscopy and particle size analysis allowed classifying the soil as clayey. After leaching testing in the soil, was observed in column A a weak adsorption of cadmium and a higher concentration of nickel which can be credited to its smaller radius and higher electronegativity, important characteristics which allow the occurrence of an adsorption more stronger, more resistant to leaching. Under the conditions of the experiment, Cd and Ni demonstrated potential to contaminate and affect the natural cycles of soil. In the analysis of soil contaminated with batteries was observed a favored retention and more extensive for cadmium than for nickel. Probably, cadmium was not retained solely due to adsorption by the soil, but also because of low solubility compounds precipitation in soil's pores, and, surely, the time was not sufficient to have occurredthe complete degradation and leaching of all battery components in soil column. It was also observed that the disposal of Ni-Cd batteries directly to the soil tends to increase the concentration of nickel (349 mgkg-1) and cadmium(2890 mgkg-1),sometimes exceeding intervention values determined by CONAMA 420/09