Avaliação da utilização de cinzas de queima de bagaço de cana-de- açúcar na biossorção de corantes presentes em águas residuárias têxteis

Abstract

The presence of dyes in textile effluents is considered one of the biggest problems by industries. These substances are mostly characterized by their low degradability, high toxic and carcinogenic potential and they can contaminate the environment and cause several problems that involve public health. In order to remedy these impacts, techniques to process these compounds are studied. Adsorption has been one of the widely accepted techniques to carry out environmental treatment of these effluents. This process is based on the affinity that some varieties of solids have in retaining certain substances on their surface. Biosorption is the adsorption process through the use of agro-industrial waste as adsorbent. The present work aimed to evaluate efficiency of ash from sugarcane bagasse in biosorption of AZUL dye BG-R CONC-EA, which it is widely used in textile industries. Tests were carried out at Federal University of São Carlos, Lagoa do Sino campus, and they contemplated preparation and characterization of adsorbent material and carried out on material with large percentage of carbon element in its composition. This can help in technique efficiency. The surface area, the volume of the pores and micropores were determined, being 333 m².g-1, 0,21 cm3/g e 0,09 cm3/g, respectively. These results were similar to those found in the literature.. The characterization of dye was also carried out, according to the Chemical Safety Information Sheet and the modeling of adsorption behavior using Langmuir isotherm. Results of isotherms revealed that all tested solutions are within favorable range to adsorption process and the solution, with a volume of 0.1 g of ash, presented the highest value of maximum adsorption capacity with separation factor closest to 1. It is concluded that the material chosen as an adsorbent has the potential to be used in the purification of wastewater from the textile industry. However, further studies should be carried out to improve the material's absorptive power.