Chitosan/Cellulose Functional Composite Hydrogel as Adsorbent for the Removal of Cu(II) from Aqueous Solutions in Dynamic Adsorption System

Water contamination by heavy metals remains a major global challenge, requiring efficient, sustainable, and low-cost remediation materials. Chitosan and cellulose are recognized as effective biosorbents due to their high affinity toward metal ions, biodegradability, and availability. However, their individual limitations motivate the design of composite with enhanced properties. In this study, chitosan/cellulose composite hydrogel beads crosslinked with glutaraldehyde (CHB-CF-GLA) were synthesized and evaluated for Cu(II) removal under batch and dynamic conditions. The composite was characterized by FESEM-EDS, ATR-FTIR, XRD, swelling analysis, and determination of pHpzc to elucidate its structural and physicochemical features. Batch experiments optimized pH, initial Cu(II) concentration, and adsorption capacity, while non-linear kinetic and isotherm models described the adsorption mechanism. The adsorbent exhibited good stability and reusability over multiple cycles. Fixed-bed column studies demonstrated that increasing bed height prolonged breakthrough and exhaustion times, while higher influent concentrations and flow rates led to earlier column saturation. The experimental breakthrough curves were well described by the Thomas and Yoon–Nelson models, whereas the Adams–Bohart model showed limited applicability. COMSOL Multiphysics 3.5 simulations validated the experimental data and predicted column performance. Overall, CHB-CF-GLA is an efficient and functional adsorbent with strong potential for continuous Cu(II) removal in water treatment applications.