ABSTRACT
Adsorption has been studied as an alternative to the treatment of textile effluents containing toxic, carcinogenic, mutagenic dyes that also interfere in the equilibrium of aquatic ecosystems when discharged in the environment without proper previous treatment. This problem is as 50% of the amount of dye applied in the steps of dyeing and laundering does not attach to the fabric fibers. The aim of this study was to evaluate color removal from an aqueous solution containing blue direct dye at an initial concentration of 5 g/L, by the adsorption on ceramic clay. For this purpose, the ranges of diameter of 1.21 mm to 2.4 mm and 2.41 mm to 4.8 mm and the quantities mass of 200, 250 and 300 g of the adsorbent were selected for each range. Assays were carried out under constant agitation of 120 rpm at room temperature, with a total duration of 5 hours, to evaluate the performance of the adsorption from the values obtained for color removal. Furthermore, the results were adjusted to the kinetic pseudo-first order and pseudo-second order models of Lagergren. In all the experimental settings evaluated, the equilibrium was reached after the first hour of the assay and the color removals varied from 98.2% to 99.5%. Regarding the adsorption capacity by the mass of the adsorbent, the best results were verified with mass of 200 g of the adsorbent. It was also found that results were moderately effective at the lowest range of diameter (0.5% higher than the performance of larger diameters). The pseudo-second order kinetics model fits better to the experimental data when compared to the pseudo-first order. It was possible to conclude from the research that the red clay acquired in the Metropolitan Region of Curitiba was an effective material in the removal of the Direct Blue dye from an aqueous solution
Keywords:
Adsorption; direct blue; red clay; kinetic
