Uso de silicatos modificados na remoção de corantes de efluentes aquosos

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

2012

RESUMO

This thesis describes the preparation, characterization and application of new inorganic/organic hybrid materials, obtained from organo-functionalization of lamellar surface of derivatives of keniaíta, magadeíta and RUB-18 silicates. The products obtained were treated with silylating agents by different methods. The materials were characterized by FTIR for verifying the presence of characteristic functional groups. The X-ray diffraction showed the crystallinity and scanning electron microscopy micrographs provided by the structural morphology of silicates. The specific surface area and porosity of the adsorbent was obtained by calculation of area and pore volume using the BET and BJH methods. Nuclear magnetic resonance spectra 29Si and 13C solid state have shown the success of the synthesis. The results of elemental analysis determined the amounts of organic groups on the surface and immobilized by thermogravimetric analysis (TGA) results of the temperatures at which the materials exhibited thermal stability. Effects of adsorbent dosage and effect of acidity by varying pH of the solutions were studied for different materials to optimize the best working conditions for adsorption. The adsorption isotherms were obtained by batch process and experimental data used to fit the Langmuir, the Freundlich, the Sips and the Redlich-Peterson isotherm models, considering heterogeneous surfaces. For kinetic models were utilized to obtain valuable information about a possible mechanism of adsorption in which the tested models were Avrami fractional order, pseudo-first order, pseudo-second order and chemisorption of Elovich. The results showed the feasibility of applying these lamellar silicates modified as efficient adsorbents for the removal of textile dyes from contaminated aqueous effluents.

ASSUNTO(S)

silicatos tratamento de resíduos adsorcao soluções aquosas

ACESSO AO ARTIGO

Documentos Relacionados