Reusability of brilliant green dye contaminated wastewater using corncob biochar and <i>Brevibacillus parabrevis</i> : hybrid treatment and kinetic studies

Abstract

This work highlights the potential of corncob biochar (CCBC) and <i>Brevibacillus parabrevis</i> for the decolorization of brilliant green (BG) dye from synthetically prepared contaminated wastewater. The CCBC was characterized by proximate, Fourier-transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, and Brunauer-Emmett-Teller analysis, respectively. Different parameters affecting the adsorption process were evaluated. The experimental results were analyzed by the Langmuir and Freundlich isotherm models. Kinetic results were examined by different models; pseudo-second-order model has shown the best fit to the experimental data. Anew positive values of <i>ΔH^o</i> (172.58 kJ/mol) and <i>ΔS^o</i> (569.97 J/K/mol) in the temperature range of 303-318 <i>K</i> revealed that the adsorption process was spontaneous and endothermic. The present investigation showed that the bacteria immobilized with CCBC showed better BG dye degradation. The kinetic parameters, <i>μ_max, Ks</i>, and μ <i>_max,</i> were found to be 0.5 per day, 39.4 mg/day, and 0.012 L/mg/day using Monod model, respectively. The adsorbent with bacteria showed good potential for the removal of cationic BG dye and can be considered for the remediation of industrial effluent.