Elucidating Adsorption Mechanisms of Copper Ions on Surfactant-Modified Zeolites: An Integrated Study of Isotherm Modeling and Surface Characterization

This research examines the adsorption mechanisms pertaining to copper ions on clinoptilolite zeolite that has been modified with cationic (CTAB) and anionic (SDS) surfactants. Given that the fundamental principles that dictate adsorption phenomena, particularly the influence of surfactant charge, are not thoroughly comprehended, this investigation adopts a comprehensive methodology that integrates isotherm modeling alongside surface characterization data to scrutinize the adsorption dynamics. Equilibrium data were subjected to analysis through a variety of isotherm models. The findings indicated that the SDS-modified zeolite demonstrated a significantly enhanced adsorption capacity (۱۹.۵۶ mg/g), which is more than twice that of the unmodified zeolite (۸.۹۸ mg/g). The adsorption behavior was most accurately represented by the Redlich-Peterson isotherm, with the observed performance improvement ascribed to the synergistic effects resulting from an increased specific surface area and favorable electrostatic interactions. In contrast, zeolite modified with CTAB exhibited a diminished adsorption capacity of ۷.۰۸ mg/g, while the Frumkin isotherm suggested the presence of repulsive interactions. For the unaltered zeolite, the Weber-van Vliet model yielded the most accurate representation, indicating a hybrid mechanism of adsorption. This research underscores the notion that the charge of the surfactant is a pivotal determinant of the adsorption mechanism. By disentangling the influences of surface area from electrostatic interactions, it establishes a quantitative framework for the development of effective adsorbents.

کلیدواژه ها:

Zeolite ، Surfactant Modification ، Copper Adsorption ، Adsorption Mechanism ، Isotherm Modeling