Utilização de carvão ativado e nanopartículas de magnetita na adsorção do corante reativo azul BF- 5G

• Ano de defesa: 2016
• Autor(a) principal: Melo, N. H.
• Orientador(a): Ostroski, Indianara Conceição
• Banca de defesa: Ostroski, Indianara Conceição , Martins, PR , Barbosa, Danns Pereira, Brito, Núbia Natália de, Alonso, Christian Gonçalves
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Goiás
• Programa de Pós-Graduação: Programa de Pós-graduação em Química (IQ)
• Departamento: Instituto de Química - IQ (RG)
• País: Brasil
• Palavras-chave em Português: Adsorção; Corante; Carvão ativado
• Palavras-chave em Inglês: Adsorption; Dye; Activated charcoal
• Área do conhecimento CNPq: QUIMICA ANALITICA::ANALISE DE TRACOS E QUIMICA AMBIENTAL
• Link de acesso: http://repositorio.bc.ufg.br/tede/handle/tede/6455

The removal of textile dyes requires special attention due to their effects on the environment and human health. At least 20% of dyes used in the textile reach the environment through industrial effluents. This pollution of water sources by dyes affect the biological cycles and the photosynthetic processes. Thus, the adsorption with activated carbons stands out for its versatility, high efficiency and low operating costs. This work seeked to study the adsorption mechanism of the commercial textile reactive blue BF - 5G dye in activated bone charcoal, pure and magnetized with magnetite nanoparticles in batch system, as well as in fixed bed columns but with pure carbono only. The adsorbents were characterized by determining the point of zero charge (PZC), adsorption and desorption of N2, infrared spectroscopy, Boehm method, diffraction of x - rays, magnetization curves, transmission electron microscopy and transmission electron scanning. For the activated bone charcoal, the PZC was 8.04, confirmed by the Boehm method that quantified 1.4 meq.g-1 basic groups. The N2 adsorption showed the predominance of mesopores. The infrared spectrum revealed peaks mainly attributed to the structure of the hydroxyapatite. As for the synthesized magnetite nanoparticles, it was possible to calculate the average particle size from the x – ray diffractogram and the Scherrer equation. The value found was approximately 18 nm. By the magnetization curve, it was concluded that the material has superparamagnetic characteristics. The equilibrium time for the adsorption experiments was approximately 8 hours, and the pseudo-second order model showed the best fit to the experimental data. Adsorption isotherms were adjusted and the best model for the tests in batch system, for both pure coal as well as the magnetized coal, was the Langmuir model. The pure coal revealed a maximum 192.31 mg.g- 1 of amount adsorbed and the magnetized carbon revealed an amount of 93.81 mg.g-1 at 50 ° C. The process showed endothermic behavior, increasing the adsorption with the increase of temperature. The process in fixed-bed columns was more efficient with the flow rate adjusted to 2 mL.min-1 and it was only possible to be adjusted through the linear Freundlich model. A final evaluation was made in which the effluent was characterized before and after the adsorption process aiming a disposal in accordance with the current legislation. The analyzed parameters were respecting the maximum permissible values, except for COD.