Produção e avaliação da farinha da casca de banana como bioadsorvente na remoção de corantes têxteis em águas residuárias

Abstract

The textile sector is known for the large use of chemicals and its high power to contamination of water resources due to the generation of large quantities of wastewater. This work aimed to produce and evaluate the flour banana peel as an adsorbent for the removal of textile dyes. The adsorbent was obtained by drying in an hothouse with air circulation banana peels cut into cubes, in different operating conditions of temperature, mass, and drying time. The adsorption kinetic tests were performed in finite bath using 2.5 g of biomass and a dye solution blue cassafix CA-2G, with a concentration of 200 mg.L -1 . In the study adsorption equilibrium was used 0.25g of banana peel flour and different concentrations of the dye solution ranging from 25 mg.L -1 and 200 mg.L -1 , with the contact time of 8 hours, under agitation of 80 rpm in finite bath. According to the statistical analysis of the experimental design 2 3 drying showed that factors (mass, time, temperature) are all statistically significant, and that the obtained model is statistically significant, considering that F (calculated) is larger than the F (tabulated). Among the models tested for the drying process the one that best adjusted the experimental data was the model proposed by Midili, common coefficient of determination (R 2 ) above 0.96 for all drying tests. It was found that the adsorbent with lower moisture levels, provides better dye removal efficiencies. In this work was obtained removal efficiency around 50% using a residence time of 60 minutes. The kinetic model of pseudo-second order showed better comparison of the experimental data, with determination coefficients above 0.97. The equilibrium isotherm model that best fit the experimental data obtained in the adsorption was the model proposed by Sips, obtaining coefficient of determination the value of 0.97047, showing that the adsorption cooperatively. The banana peel flour is a byproduct agro-industrial low-cost which proves to be an adsorbent potential for removing textile dye studied.