A Mechanistic Approach to Methylene Blue Adsorption by Synthesized and Commercial H‐Beta Zeolite
Nesrine Bensaid, Mounir Khelifa, Abdelkrim Hasnaoui, Fodil Aoulmi, Mohamed Sassi, Ali Çoruh, Amine Khelifa
Abstract
Abstract This study assessed the adsorption performance of methylene blue using both laboratory‐synthesized and commercial H‐Beta zeolites. The materials referred to as H‐Beta Syn and H‐Beta Com , respectively, were evaluated using XRD, SEM, nitrogen adsorption at 77 K, and FTIR. Beta zeolite demonstrated outstanding characteristics, including high specific surface area, 3D pore network, and a high density of catalytically active sites, all contributing to its excellent catalytic performance. Our objective was to evaluate whether its remarkable properties for catalysis could be transferred to liquid‐phase adsorption, given that this zeolite has seen limited application in this area. The adsorption of methylene blue by H‐Beta Syn and H‐Beta Com was maximal at a pH of 9.8. The maximum quantities adsorbed at 55 °C were 342.4 mgg⁻¹ and 310.8 mgg⁻¹, respectively. The adsorption process followed a Langmuir–Freundlich isotherm and exhibited second order kinetics. H‐Beta Syn retained a similar adsorption capacity over four cycles of adsorption–desorption with ethanol as desorbent. The mechanism was driven by electrostatic interaction and hydrogen bonding between methylene blue and H‐Beta Syn . Spectroscopy revealed why H‐Beta Syn adsorbs more methylene blue than H‐Beta Com . A better understanding of the adsorption and interaction mechanisms is expected to further enhance the applications of our promising adsorbent in pollution remediation.