Estudo do efeito de adsorvente alternativo de casca de laranja pera rio (citrus sinensis L. osbeck) na adsorção de corante têxtil vermelho reativo BF-4G

Abstract

The textile industries currently comprise one of the world's largest generation of wastewater, because in its processing requires large amounts of water. The textile sector stands out for using large amounts of chemicals such as dyes. The textile dye has high toxicity and carcinogenic in his stable, non-biodegradable majority. Thus the removal of dyes and other compounds of industrial effluents is of great interest. Various methods have been employed for the removal of dyes and other compounds existing in the effluent. One of the methods used on an industrial scale is adsorption on activated carbon, since it has great efficiency in the adsorption process. However, treatment of textile effluents by adsorption requires information on the removal capacity, and low cost of production of the adsorbent. Thus, several alternatives to replace the activated carbon were investigated, one is replacing the activated charcoal agroindustrial residue. In this context, this study aims to evaluate the adsorption capacity of an agroindustrial residue (orange peel) in the removal of a textile dye Reactive Red BF-4G synthetic sewage. With the aim to characterize the adsorbent analysis were performed as ash, pH, acidity and fiber. Being that there was 4,53% ash, 4.84 pH and 9.26% acidity. To evaluate the influence of independent variables such as pH, particle size and mass of adsorbent, was used a factorial design 2 ³, in which the response was the percentage removal of the dye. The highest percentage removal of the dye occurred with lower levels of planning being fixed in the pH 2, particle size 0.59> 1.00 mm and 0.5 mass adsorbent. Models of pseudo 1st order and 2nd order pseudo were performed to describe the adsorption kinetics of dyes, and the model of pseudo 2nd order showed the best results. Furthermore, the adsorption equilibrium entered within 180 minutes and the maximum amount adsorbed was 5,24 mg/g to a concentration of 50 mg/L and 8.55 mg/g for concentration of 100 mg/L. Experiments to obtain the equilibrium isotherms used mathematical models of Langmuir and Freundlich isotherms were also conducted,being the equilibrium isotherms better correlated in the Langmuir isotherm. It was investigated the thermodynamic parameters which indicated that the adsorption study is exothermic and spontaneous with negative values of ΔG and ΔH respectively.