Development of chitosan/alginate/montmorillonite hydrogel microcomposite as adsorbent for paracetamol removal from waters

Abstract Chitosan-based hydrogel microcomposite beads, integrated with alginate and montmorillonite, (CHI/ALG/MMT) were synthesized and evaluated for their capacity to adsorb paracetamol from aqueous solutions. The materials’ structural and morphological features were examined utilizing Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), Differential Thermal Analysis-Thermogravimetric Analysis (DTA-TGA), and Particle Size Analysis (PSA). The effects of pH value of paracetamol solution, contact time, and initial concentration of paracetamol on the adsorption capacity of the microcomposite are investigated. The incorporation of alginate and montmorillonite significantly enhanced the adsorption performance and stability of the chitosan beads compared to those without modification. Adsorption studies demonstrated that the best removal efficiency was achieved at pH 5, with a contact time of 60 min and an initial paracetamol concentration of 80 mg L −1 . Under these conditions, the highest adsorption capacity reached 36.62 mg g −1 , with an adsorption efficiency of 85.60 %. Isotherm and kinetic investigations demonstrated that the adsorption mechanism followed to the Langmuir isotherm and pseudo-second-order kinetic models. These results highlight the potential of the CHI/ALG/MMT microcomposite as an effective and eco-friendly adsorbent for the treatment of pharmaceutical wastewater, particularly paracetamol.