M. Manigandaprasath1 and S. Thillainatarajan
Abstract
The adsorption behavior of Pregabalin, a widely used non-narcotic analgesic, was studied using activated carbon derived from waste leather. Key operational factors particle size, pH, dosage, concentration, contact time, and temperature were evaluated. Maximum adsorption (90.34%) occurred at the smallest particle size (0â63 ?m), and acidic conditions favored removal, reaching 93.01% at pH 5. Adsorption increased with dosage and contact time but decreased with higher initial concentrations. Kinetics followed the pseudo-second-order model (R² = 0.991), while isotherm data fit both Langmuir (R² = 0.916) and Freundlich (R² = 0.996) models, indicating heterogeneous multilayer adsorption. Thermodynamic results (negative ?G°, positive ?H° and ?S°) confirmed a spontaneous, endothermic, physisorption mechanism. FT-IR, SEM, and XRD analyses supported surface functional group involvement and porous morphology. Overall, waste leather activated carbon is an effective, economical, and eco-friendly adsorbent for Pregabalin removal from water.