Removal of ciprofloxacin from water: antimicrobial activity and desalination potential using synthetic Ni/Fe clay
Asmaa Elrafey, S. A. Abdel Moaty, Esraa G. Arafa, Omayma Fawzy Abdel Gawad, M. M. Kamel, Sahar Abdel Aleem Abdel Aziz, Ahmed A. Allam, Haifa E. Alfassam, Rachid Mahmoud
Abstract
Abstract Layered Double Hydroxides (LDHs), particularly Ni/Fe-Layered Double Hydroxides (Ni/Fe-LDHs), have attracted significant attention as adsorbents for environmental waste removal. This study investigates the desalination effectiveness of Ni/Fe-LDHs in removing sodium salts via ion exchange and their ability to adsorb ciprofloxacin (Cipro) contaminants from wastewater. Batch adsorption tests were conducted to evaluate the removal of salts and pollutants under varying pH, Ni/Fe-LDH dose, contact time, and pollutant concentration. Characterization of Ni/Fe-LDHs was performed using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) analysis, high resolution transmission electron microscopy (HRTEM), pH of zero gcharge (pHPZC), and Brunauer–Emmett–Teller (BET) surface area measurements. The results showed that the removal efficiency of Cipro was highest at pH 5.0, with a Ni/Fe-LDH dose of 0.05 g achieving 40.14% removal within 0–300 min. In the desalination process, the material achieved a dosage of 0.05 g, a solution concentration range of 1000–16,000 ppm, and an impressive ion removal rate of approximately 99.8%. After six cycles, regeneration or replacement of the ion-removal material may be necessary to maintain efficient desalination. Adsorption data were modeled using Langmuir, Freundlich, and Khan isotherms, demonstrating surface heterogeneity and high adsorption capacity. The prepared material demonstrated excellent re-usability, maintaining high removal efficiencies over five regeneration cycles also exhibited significant antimicrobial activity against Proteus mirabilis , Salmonella Typhimurium , Escherichia coli , Pseudomonas aeruginosa , and Klebsiella pneumoniae , with notable minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and inhibition zone values. This suggests the potential of Ni/Fe-LDHs as effective tools for bioremediation in pharmaceutical and wastewater treatment industries. The cost of using Ni/Fe-LDH was estimated at 2.02 USD/g. Graphical abstract