Demirdağ Esra, Demirel Mehmet Ferit, Benek Veysel, Doğru Elif, Önal Yunus, Alkan Mehmet Hüseyin, Erol Kadir, Alacabey İhsan
The Institute of Science, Department of Chemistry, Dicle University, 21280 Diyarbakır, Turkey.
Department of Medical Services and Techniques, Vocational School of Health Services, Artuklu University, 47100 Mardin, Turkey.
Molecules. 2025 Jun 7;30(12):2501. doi: 10.3390/molecules30122501.
Activated 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 m/g and achieved a maximum adsorption capacity of 398.4 mg·g. 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 (R = 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.
活性炭被广泛认为是一种从水中去除污染物，特别是药物残留的有效材料。在本研究中，通过KOH活化法合成了由稻壳衍生的高比表面积活性炭（RHAC），并将其用于吸附环丙沙星，一种广泛使用的氟喹诺酮类抗生素。通过改变pH值、吸附剂用量、接触时间、初始浓度和温度的批量实验，系统地研究了其吸附行为。RHAC表现出1539.7 m²/g的高比表面积，实现了398.4 mg·g的最大吸附容量。Freundlich等温线最能描述其吸附平衡，表明在异质表面上的多层吸附。动力学模型表明，吸附过程遵循准二级模型（R = 0.9981），表明化学吸附是限速机制。热力学参数（ΔH° = 6.61 kJ/mol，ΔG° < 0）证实该过程是吸热的且自发的。这些发现表明，RHAC是一种从水环境中去除环丙沙星的高效、低成本且可持续的吸附剂。
