Demirdağ, E.Demirel, M.F.Benek, V.Doğru, E.Önal, Y.Alkan, M.H.Alacabey, İ.2025-07-152025-07-1520251420-3049https://doi.org/10.3390/molecules30122501https://hdl.handle.net/20.500.12514/9077Activated carbon is widely recognized as an effective material for removing pollutants, especially pharmaceutical residues, from water. In this study, high-surface-area activated carbon derived from rice husks (RHAC) was synthesized via KOH activation and used for the adsorption of ciprofloxacin, a widely used fluoroquinolone antibiotic. Its adsorption behavior was systematically investigated through batch experiments varying the pH, adsorbent dosage, contact time, initial concentration, and temperature. The RHAC exhibited a high surface area of 1539.7 m2/g and achieved a maximum adsorption capacity of 398.4 mg·g−1. The Freundlich isotherm best describes its adsorption equilibrium, suggesting multilayer adsorption on a heterogeneous surface. Kinetic modeling revealed that the adsorption process followed a pseudo second-order model (R2 = 0.9981), indicating chemisorption as the rate-limiting mechanism. Thermodynamic parameters (ΔH° = 6.61 kJ/mol, ΔG° < 0) confirmed that the process was endothermic and spontaneous. These findings demonstrate that RHAC is a highly efficient, low-cost, and sustainable adsorbent for removing ciprofloxacin from aqueous environments. © 2025 by the authors.en10.3390/molecules30122501info:eu-repo/semantics/closedAccessActivated CarbonAdsorptionAntibiotic PollutionCiprofloxacinRice HuskArticle3012Q2Q22-s2.0-10500905218440572467