Removal of ciprofloxacin using polymeric nanocomposites synthesized from alkylated chitosan ionic macromonomers, ionic monomers and hydrotalcite.

Abstract

The contamination of water systems by antibiotics such as ciprofloxacin (CIP), which is used to treat bacterial infections, poses severe risks to environmental safety and public health. To address this issue, a novel zwitterionic polymeric nanocomposite (PNs-HTC) was developed in this study. This novel material was synthesized using alkylated chitosan ionic macromonomers, ionic monomers and combined with hydrotalcite (HTC) via in situ free radical polymerization. The incorporation of quaternary ammonium and vinyl groups into the chitosan backbone, along with varying HTC contents, considerably impacted the properties of the nanocomposite. The nanocomposite was characterized using Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, X-ray diffraction, and thermogravimetric analysis. The effectiveness of PNs-HTC in removing CIP from water was evaluated under different conditions. PNs-HTC exhibited a CIP adsorption capacity of up to 84.43 mg g^-1 at 318 K. Equilibrium data fitted well to the Temkin isotherm and pseudo-second-order kinetic models. The pH, ionic strength (30 % using 0.1 M NaCl), and HTC content in the nanocomposite influenced CIP adsorption, which reached a maximum of 80 % using 0.03 g of PNs-HTC. Thermodynamic studies indicated that the adsorption process was favorable, spontaneous, and endothermic and was marked by significant randomness. These findings underscore the potential of PNs-HTC as a robust material for mitigating antibiotic pollution in aquatic environments.