Modificação da argila montmorilonita e do carvão de coco de babaçu ativado com óxido de ferro: caracterização e aplicação na adsorção do azul de metileno

• Ano de defesa: 2010
• Autor(a) principal: Cottet, Leila
• Orientador(a): Almeida, Carlos Alberto Policiano
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: UNICENTRO - Universidade Estadual do Centro Oeste
• Programa de Pós-Graduação: Programa de Pós-Graduação em Química (Mestrado)
• Departamento: Unicentro::Departamento de Química
• País: BR
• Palavras-chave em Português: Adsorção; argila modificada; carvão ativado modificado
• Palavras-chave em Inglês: Adsorption; modified clay; modified activated carbon
• Área do conhecimento CNPq: CIENCIAS EXATAS E DA TERRA::QUIMICA
• Link de acesso: http://localhost:8080/tede/handle/tede/331

The montmorillonite clay and babassu coconut activated carbon have been modified, characterized and applied in the study of methylene blue dye adsorption. In the modification the precipitation method (ex-situ) was used. The two modified adsorbents showed magnetic characteristics and can be used in the magnetic separation. The analyses by scanning electron microscopy, energy dispersive X-ray and fourier transform infrared (FTIR) spectroscope in both adsorbents suggested that the main magnetic phase formed was magnetite. The surface area of modified clay was 118.1m²g?¹ and the modified activated carbon was 160.4 m²g?¹. The surface charge of the two materials was positive at pH 5.5. In kinetics, the results showed better adjustment to the model of pseudo-second order model. In the equilibrium study, the results showed better adjustment to Langmuir model. A rise in the system temperature resulted in an increase in the amount adsorbed. Calculated thermodynamic parameters indicated non-spontaneous systems (?Go), endothermic (?Ho). Activation energy values were 19.21 kJ moL?¹ and -14.65 kJ moL?¹ for the modified clay and the modified activated carbon, respectively, indicating a process of physical nature. With the increase in the initial dye concentration there was an increase of the amount adsorbed and a decrease in the removal percentage.