Síntese de compósito a base de quitosana e sílica para adsorção de corante têxtil

Abstract

The usual techniques for treating effluents require complementary technologies to remove efficiently the most persistent contaminants from the environment, such as dyes. For the removal of these compounds, adsorption has been shown to be effective, however, it requires adsorbent materials with favorable physical and chemical properties. Thus, the development of chitosan and silica-based composites has been investigated to improve the characteristics of the adsorbents and increase the adsorption capacity, however, it is still a challenge. Thus, this study aimed to develop a chitosan-based adsorbent composite by the sol-gel process using tetraethoxysilane as a precursor and verifying the capacity of this composite to remove textile dye in aqueous solution. The composite was developed from D-glucosamine:TEOS of 2.77:1 ratio. The material was chemically characterized, checking the preponderance of chitosan functional groups and zero load point in pH 8.90. The performance of the composite was evaluated using isotherms and adsorption kinetics of the Remazol R bright blue textile dye. The balance data were better correlated through the Liu isothermal model (R²>0.97). The adsorption kinetics were predicted by the Elovich model (R²>0.97). The development of the composite was effective to remove the dye with high adsorption capacity and preferably per electrostatic attractions.