Efficient Removal of Ciprofloxacin from Water Using High-Surface-Area Activated Carbon Derived from Rice Husks: Adsorption Isotherms, Kinetics, and Thermodynamic Evaluation
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...
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2025-06-01
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| author | Esra Demirdağ Mehmet Ferit Demirel Veysel Benek Elif Doğru Yunus Önal Mehmet Hüseyin Alkan Kadir Erol İhsan Alacabey |
| author_facet | Esra Demirdağ Mehmet Ferit Demirel Veysel Benek Elif Doğru Yunus Önal Mehmet Hüseyin Alkan Kadir Erol İhsan Alacabey |
| author_sort | Esra Demirdağ |
| collection | DOAJ |
| description | 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<sup>2</sup>/g and achieved a maximum adsorption capacity of 398.4 mg·g<sup>−1</sup>. 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<sup>2</sup> = 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. |
| format | Article |
| id | doaj-art-4952b58313d949a6b80e2ff352de056d |
| institution | OA Journals |
| issn | 1420-3049 |
| language | English |
| publishDate | 2025-06-01 |
| publisher | MDPI AG |
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| series | Molecules |
| spelling | doaj-art-4952b58313d949a6b80e2ff352de056d2025-08-20T02:21:06ZengMDPI AGMolecules1420-30492025-06-013012250110.3390/molecules30122501Efficient Removal of Ciprofloxacin from Water Using High-Surface-Area Activated Carbon Derived from Rice Husks: Adsorption Isotherms, Kinetics, and Thermodynamic EvaluationEsra Demirdağ0Mehmet Ferit Demirel1Veysel Benek2Elif Doğru3Yunus Önal4Mehmet Hüseyin Alkan5Kadir Erol6İhsan Alacabey7The Institute of Science, Department of Chemistry, Dicle University, 21280 Diyarbakır, TurkeyDepartment of Medical Services and Techniques, Vocational School of Health Services, Artuklu University, 47100 Mardin, TurkeyVakıfbank Secondary School, Ministry of National Education, 65300 Van, TurkeyDepartment of Chemistry, The Institute for Graduate Educational Studies, Artuklu University, 47100 Mardin, TurkeyDepartment of Chemical Engineering, Faculty of Engineering, Inonu University, 44280 Malatya, TurkeyDepartment of Basic Pharmaceutical Sciences, Faculty of Pharmacy, Dicle University, 21280 Diyarbakır, TurkeyDepartment of Medical Services and Techniques, Vocational School of Health Services, Hitit University, 19030 Corum, TurkeyDepartment of Medical Services and Techniques, Vocational School of Health Services, Artuklu University, 47100 Mardin, TurkeyActivated 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<sup>2</sup>/g and achieved a maximum adsorption capacity of 398.4 mg·g<sup>−1</sup>. 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<sup>2</sup> = 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.https://www.mdpi.com/1420-3049/30/12/2501activated carbonadsorptionantibiotic pollutionciprofloxacinrice husk |
| spellingShingle | Esra Demirdağ Mehmet Ferit Demirel Veysel Benek Elif Doğru Yunus Önal Mehmet Hüseyin Alkan Kadir Erol İhsan Alacabey Efficient Removal of Ciprofloxacin from Water Using High-Surface-Area Activated Carbon Derived from Rice Husks: Adsorption Isotherms, Kinetics, and Thermodynamic Evaluation Molecules activated carbon adsorption antibiotic pollution ciprofloxacin rice husk |
| title | Efficient Removal of Ciprofloxacin from Water Using High-Surface-Area Activated Carbon Derived from Rice Husks: Adsorption Isotherms, Kinetics, and Thermodynamic Evaluation |
| title_full | Efficient Removal of Ciprofloxacin from Water Using High-Surface-Area Activated Carbon Derived from Rice Husks: Adsorption Isotherms, Kinetics, and Thermodynamic Evaluation |
| title_fullStr | Efficient Removal of Ciprofloxacin from Water Using High-Surface-Area Activated Carbon Derived from Rice Husks: Adsorption Isotherms, Kinetics, and Thermodynamic Evaluation |
| title_full_unstemmed | Efficient Removal of Ciprofloxacin from Water Using High-Surface-Area Activated Carbon Derived from Rice Husks: Adsorption Isotherms, Kinetics, and Thermodynamic Evaluation |
| title_short | Efficient Removal of Ciprofloxacin from Water Using High-Surface-Area Activated Carbon Derived from Rice Husks: Adsorption Isotherms, Kinetics, and Thermodynamic Evaluation |
| title_sort | efficient removal of ciprofloxacin from water using high surface area activated carbon derived from rice husks adsorption isotherms kinetics and thermodynamic evaluation |
| topic | activated carbon adsorption antibiotic pollution ciprofloxacin rice husk |
| url | https://www.mdpi.com/1420-3049/30/12/2501 |
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