Estudo da adsorção de corante têxtil em fibras naturais de bucha vegetal (Luffa cylindrica)

Abstract

The textile industry has a high potential for contamination, because it is the use of products and dyes that are fixed both in the process of dyeing in clothes, as in its wastewater. Aiming to reduce these textile dyes, the adsorption process is used, which has a good efficiency with its mass transfer mechanism to the adsorbent. It was used the vegetal bush, with the purpose of evaluating its efficiency as an adsorbent in the removal of the textile dye, by means of synthetic solution of the Reactive Orange (BF-GR) of the company Texpal Química (Valinhos, SP). The adsorbent was characterized by proximal analysis, determination of moisture, volatile matter, ash, fibers, zero charge point (pHpcz) and scanning electron microscopy (SEM), besides the kinetic, thermodynamic and adsorption equilibrium studies. As a result, Luffa cylindrica showed to have 7.44% of moisture, 98.73% of volatile matter, 1.27% in ash and 73% of its structure in fibers. The obtained pHpcz was of 6,42 and through the extensions of the MEV it was verified interweaving of the fibers in its external and internal surface. The kinetic model applied for pseudo-first order and pseudo-second order showed, through the experimental data, the data being adjusted for the pseudo-second order model. The equilibrium isotherms were tested for the adsorption isotherms of Freundlich and Langmuir, where Langmuir was found to be suitable for the assay. For thermodynamics, different temperature ranges were selected, which presented positive values for the ΔG representing a non-spontaneous process and positive values for the ΔH, indicating an endothermic reaction, concluding that it is a chemical adsorption process, ΔS positive indicates an increase in the randomness in the Solid-liquid interface. The L. cylindrica vegetal bush proved to be efficient for the adsorption process of the Reactive Orange dye (BF-GR).