Paracetamol adsorption study using chitosan (Chi)-alginate (Al)-zeolite clinoptilolite (Cpl) hydrogel composite

• Structural and chemical properties of Chitosan-Alginate Zeolit Clinoptilolite hydrogels. • Synthesis and characterization of Chitosan-Alginate Zeolit Clinoptilolite hydrogels. • Effective adsorption of paracetamol using Chitosan-Alginate Zeolit Clinoptilolite hydrogels. • Adsorption kinetics and isotherm models for paracetamol removal • Challenges and future perspectives in hydrogel applications. This research aims to characterize, the adsorption performance, and desorption behavior of chitosan–alginate–zeolite clinoptilolite hydrogel beads for paracetamol removal. The adsorbent was analyzed using FTIR, XRD, SEM, DTA-TGA, and PSA to confirm its chemical structure, crystallinity, morphology, and stability. The results showed that the synthesized adsorbent contained O–H, N–H, C–H, C=O, C–O, Si–OH, and Si–O–Si functional groups, and possessed a crystalline and porous structure suitable for adsorption. The optimal conditions for paracetamol adsorption were determined to be pH 5, a contact time of 30 minutes, and an initial concentration of 80 ppm. Under these conditions, the chitosan–alginate–zeolite clinoptilolite beads achieved an adsorption efficiency of 84.20% and a capacity of 33.26 mg/g, higher than those of pure chitosan beads. The adsorption followed the Langmuir isotherm and pseudo-second-order kinetic models, indicating monolayer and chemisorption processes. Thermodynamic analysis revealed negative Gibbs free energy, confirming spontaneous adsorption. Among several tested agents, KNO₃ was the most effective desorption agent, with the highest paracetamol recovery of 34.02%. These results demonstrate that chitosan–alginate–zeolite clinoptilolite hydrogel beads are promising, efficient, and reusable adsorbents for removing pharmaceutical contaminants from wastewater.