Turning E-waste into water treatment: preliminary physicochemical and diffusion‑based ion‑transport assessment of cationic cellulose acetate-based membranes

Water pollution by heavy metals poses serious environmental and public health risks, driving the need for cost‑effective and sustainable treatment technologies. This study explores the fabrication and performance of novel ion‑exchange membranes (IEMs) based on cellulose acetate (CA) blended waste keyboard particles. Three membrane types were produced: MStd (CA), MR (CA and cationic resin) and MKey (CA and keyboard particles), and each was tested with and without HCl activation. Physicochemical characterization included hydraulic permeability, water uptake, porosity, drop contact angle, ion exchange capacity (IEC), FTIR, and SEM analyses. Results showed that both MR and MKey membranes exhibited significantly higher permeability and IEC compared to MStd, while porosity and water uptake remained similar, indicating effective structural blending. Contact angles confirmed hydrophilicity across all samples, and FTIR/SEM data demonstrated that acid activation did not alter membrane morphology or surface functional groups. In diffusion tests using a copper chloride solution (1200 ppm), acid-activated MR and MKey reached concentration equilibrium more rapidly (180–240 min) than their non-activated counterparts, highlighting improved ion-transport kinetics. These results demonstrate the feasibility of incorporating keyboard‑derived residues into cellulose acetate membranes and indicate promising diffusion‑based ion‑transport behavior.