Reusable Ethylenediamine-Grafted Cellulose Fabric for Efficient Cu(II) and Pb(II) Removal from Water

In response to the growing problem of water contamination by heavy metals, this work presents the design of an innovative and promising bioadsorbent: a cellulose fabric functionalized through covalent grafting of ethylenediamine (Cell-EDA). The chemical modification was carried out in three successive steps: alkaline mercerization, tosylation in pyridine medium, and nucleophilic substitution. FTIR spectroscopy, supported by a semi-quantitative analysis of characteristic absorption bands, confirmed the successful introduction of amine groups. The adsorption performance was evaluated for Cu(II) and Pb(II) ions as a function of pH, contact time, and initial concentration. Maximum removal efficiencies reached 90% for Cu(II) at pH 4 and 96% for Pb(II) at pH 8. Kinetic studies followed a pseudo-second-order model, indicating chemisorption. The Freundlich and Temkin isotherms revealed multilayer adsorption on heterogeneous surfaces, while the Langmuir model yielded maximum adsorption capacities of 55.9 mg/g for Cu(II) and 131.6 mg/g for Pb(II), highlighting the strong retention capacity of the material. The Cell-EDA fabric retained over 75% of its adsorption efficiency after five consecutive cycles, demonstrating good stability and excellent reusability. The use of cellulose fabric, which offers greater mechanical strength than powder or paper-based supports, gives Cell-EDA significant potential for sustainable applications in the treatment of heavy metal-contaminated effluents.