Assessment of Brilliant Green and Eriochrome Black T dyes adsorption onto fava bean peels: kinetics, isotherms and regeneration study
Loubna Nahali, Youssef Miyah, Fatiha Mejbar, Mohammed Benjellοun, Ouissal Assila, Youssef Fahoul, Valentin Nenov, Farid Zerrouq
Abstract
ABSTRACT This research aims to assess the employability of fava bean peels (FBP) as low-cost adsorbents in the removal of Brilliant Green (BG) and Eriochrome Black T (EBT) from aqueous solutions and therefore in colored wastewater treatment. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), and pH PZC were used to characterize these materials. The constants of Langmuir, Freundlich, and Dubinin-Radushkevich have all been determined. The adsorption capacity of BG and EBT was 28.14 and 7.91 mg g –1 , respectively, at 5 g L –1 FBP dose, 40 mg L –1 initial dye concentration, temperature 20°C, and contact time BG (80 min) and EBT (40 min). The calculated thermodynamic parameters indicated that adsorption of BG was endothermic and exothermic for EBT. The isotherm studies show that the adsorption experimental data of both dyes are fitted well by the Freundlich isotherm model. The adsorption of the two dyes studied on fava bean peels is perfectly described by a pseudo-second-order kinetic model. Cyclic experiments have indicated that the current bio-adsorbent can be effectively reused to remove BG and EBT from aqueous solutions. Removal efficiencies remained above 84% and 10% for BG and EBT respectively even after four adsorption–desorption cycles. As a consequence of these relevant results, our inexpensive and environmentally friendly material could provide enormous application prospects in large-scale wastewater treatment in the industrial level.