Removal of Remazol Black B dye using bacterial cellulose as an adsorbent

Abstract

Effluents from textile processes, when discarded of inappropriately, have been shown to be a major environmental concern. In this way, different methods can be used, among them adsorption is an economical and efficient technique in the removal of dyes. Therefore, we propose to analyze the adsorptive capacity of bacterial cellulose (CB) against effluents containing the dye Remazol Black B (RBB). CB was produced by the bacterium Gluconacetobacter hansenii and characterized by the techniques of FTIR, DRX, TGA / DTG and pH (PCZ). The RBB removal tests were initially performed at different pHs. From the best experimental condition, new tests were performed at temperatures of 30, 40, 60 and 100 ± 2 °C, 150 rpm, pH 3.5, using 0.5 g of adsorbent in the concentrations of dye from 25 to 65 mg·L^-1. The kinetic study showed that the system balance was achieved in 80 minutes. The experimental data were better described by the pseudo-second order model. The equilibrium results showed that the experimental data fit the Langmuir model (q_max 17.513 mg·g^-1). The thermodynamic parameters of adsorption showed that the process is exothermic, not spontaneous and also presented low system randomness. The activation energy (Ea) was 23.8 kJ·mol^-1 characterizing physical adsorption. The residual water was not toxic to animal or microbial cells. Bacterial cellulose proved to be a good low-cost adsorbent, easy to acquire and which can be used in the adsorption process.