This study focuses on the improvement of bioremediation of textile dye Reactive Red 195 using agro-industrial waste, groundnut oil cake (GNOC) obtained after oil-pressing. The treatment of GNOC with 1 N H2SO4 had resulted in physiochemical changes on the insoluble porous adsorbent, which improved their adsorption efficiency. The dye removal efficiency increased from 55% to 94% on acidification of GNOC. The raw groundnut oil cake (RGNOC) and acid-treated groundnut oil cake (AGNOC) were characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction, and zeta potential. The rate and efficiency of dye adsorption were examined using adsorption kinetics and isotherm models. The results confirm that acid-treated GNOC eliminates impurities, alter the surface functional groups, and significantly increase porous surface areas of RGNOC. The investigation of key factors such as contact time, initial concentration of dye, static/agitation impact, particle size, and adsorbent dose had significantly influenced adsorption capacity of GNOC. Adsorption of dye fits best into the Langmuir model and equilibrium data of dye on AGNOC was explained by psuedo-second-order reaction with maximum adsorption capacity of 12.65 mg/g. This emphasis AGNOC has a very excellent potential to remove the textile dye Reactive Red dye from industrial effluent.
Keywords: Adsorption; Langmuir model; Reactive Red 195; adsorption kinetics; bioremediation; groundnut nut oil cake.
This study reports the primary investigation exploring the application of groundnut oil cake (RGNOC) and its acid-modified (AGNOC) version for the bioremediation of industrially used textile dye Reactive Red 195 (RR195). The core objective of this study is to use a low-cost biosorbent to remove RR195 dye from effluent that pose risk to the health and environment. This study analyses the adsorption capacity of RGNOC and its acid-modified version AGNOC to treat contaminated water and the influencing parameters. AGNOC adsorption potential for RR195 dye sequestration was shown to be higher compared to RGNOC. Acidification of the adsorbent is simple, cost expensive, and more efficient alternate approaches to scale up for industrial application. As a result, an attempt has been made to add a new adsorbent to the database.