A Novel Eco-friendly Bionanocomposite: Synthesis, Optimizing Grafting Factors, Characterization, Adsorption of Ofloxacin Hydrochloride, Reinforcement Elimination System to Pharmaceutical Contaminants

This study synthesized a novel bionanocomposite from the natural materials kappa-carrageenan and bentonite using classical free radical polymerization. The carrageenan-grafted-poly(acrylamide-co-acrylic acid)/bentonite bionanocomposite was characterized and investigated for the removal of the antibiotic drug ofloxacin hydrochloride as Pharmaceutical pollution from aqueous solutions. Fourier-transform infrared spectroscopy, field emission scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, and Brunauer-Emmett-Teller techniques were utilized to determine the structure and characteristics of the bionanocomposite. The effects of ionic strength, pH, monomer concentration, initiator concentration, and crosslinker concentration on the swelling behavior and drug adsorption capacity were examined. The results showed that these parameters significantly influenced swelling and adsorption. Low crosslinker and medium initiator levels yielded maximum swelling. Ofloxacin removal reached 81.9% under optimized acidic conditions. Adsorption kinetics and isotherms were analyzed, with the equilibrium data fitting well to the Freundlich model. Thermodynamic evaluation revealed that the adsorption process was spontaneous, exothermic, and physisorption-driven. Maximum drug removal occurred at pH 6, 180 min contact time, and with increasing monovalent cation (Na+, K+) concentration, while divalent Ca2+ ions decreased removal. The point of zero charge was determined to be 4.2.

Automated summary

This study synthesized a novel bionanocomposite from kappa-carrageenan and bentonite, which showed excellent drug adsorption capacity for the removal of ofloxacin hydrochloride from aqueous solutions. The structure and characteristics of the bionanocomposite were determined using various techniques, and the effects of different parameters on swelling and adsorption behavior were investigated. The results showed that the bionanocomposite exhibited maximum swelling at low crosslinker and medium initiator levels. Thermodynamic evaluation revealed that the adsorption process was spontaneous and physisorption-driven. The optimal conditions for ofloxacin removal were found to be pH 6 and 180 min contact time.