Remoção de arsênio de águas por adsorção em esferas de quitosana-ferro(III)-reticulada

• Autor(a) principal: Marques Neto, José de Oliveira
• Data de Publicação: 2010
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2125
• topic: Arsênio; Adsorção; Quitosana-ferro (III)-reticulada; Águas; Arsenic; Adsorption; Chitosan-iron(III)-spheres; Waters; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA ANALITICA

This study initially addresses the problems of arsenic contamination and its effect and consequence on organisms. Biopolymers and their applications in the decontamination of waters, together witch removal of arsenic from natural waters by adsorption, employing chitosan and its derivatives, are also considered. Contamination of waters by arsenic is a subject of great environmental importance since it is viewed as one of the most toxic elements to organisms. Due to the health risk, world environmental departments must reconsider arsenic limits in water. In Brazil, CONAMA, by means of resolution 357/2005, defined a maximal concentration of 10 μg L-1 of total arsenic in potable water. In many locations on the planet the contamination of waters by arsenic is a matter of public health and has caused grave consequences in human health and even death in some cases. Therefore this study proposes a safe, efficient and ecologically variable method for decontamination of waters containing arsenic. The experiment consists of two adsorption methods, one static and anothers dynamic. The first method achieved an adsorption rate of 84 %, with As concentrations of 75 ppm, a value much higher than normally found in natural waters. This adsorption is also quite specific in relation to As compared to other anions studied, and phosphate is the one which most often interferes with As adsorption. Using the dynamic method an adsorption capacity of 195.98 mg g-1 was obtained along with complete desorption from the adsorbent material, which can be reused inseveral adsorption/desorption cycles. Not only was QTS-Fe(III)-R experimentally proven as an efficient adsorbent, the process presents important social and environmental aspects due to improved health conditions of the population and low generation of residues by immobilization of the contaminant in the solid phase and its pre-concentration when performing desorption assays.