Adsorção do corante verde malaquita em penas de frango

Abstract

The current consumption pattern of society has led to degradation of water quality, threatening public health and environmental balance. For this reason, discarded wastewater needs the proper treatment so that with its discharge to the receiving water course is guaranteed the environmental preservation and maintenance of human health. The textile industry is one of the largest consumers of water in Brazil and its effluents have a high concentration of synthetic dyes, among them malachite green. Among the options for the treatment of this type of effluent, the adsorption is highlighted by the efficiency of compounds removal at low concentrations. This work aimed to evaluate the use of biosorbent chicken feather for adsorption of malachite green dye in aqueous solution. The kinetic and thermodynamic equilibrium studies were conducted for the system. The equilibrium studies were conducted at different initial concentrations for each temperature evaluated (35, 40 and 45°C). In the kinetic studies, a temperature of 20 ºC and different solid-liquid ratios (2, 3 and 4 g L​-1​) were used. The results obtained from the equilibrium experiments, coupled to the thermodynamics of the process (Van't Hoof equation) pointed to the Langmuir model as the most appropriate. That is, Gibbs-free monolayer adsorption characteristic of spontaneous and favorable process, with the coexistence of chemisorption and fisistion. For this evaluation, we used the corrected Akaike information criterion, calculated from the nonlinear data minimization results. The kinetics of the process showed that the adsorbent presented the Pseudo first order kinetics, with equilibrium capacity, obtained in 5h, which increased with the decrease of the amount of adsorbent used, and kinetic constant that increased with increasing adsorbent availability. Therefore, the feathers of chicken were shown as adsorbent of low cost and with capacity for the removal of malachite green of aqueous solutions, where in the experimental experiments the options of up to 6 mg g​-1​ were necessary.