Double-layer (DL) electrodialysis cation exchange membranes (CEMs) were fabricated for copper ion removal from water. New membranes were prepared by deposition (chitosan-co-TiO2 nanoparticles) layer on polyvinyl chloride–based heterogeneous CEMs. The FTIR, FESEM, energy-dispersive X-ray analysis, and 3D-surface images were applied for membrane characterization. Membrane hydrophilicity, flux, conductivity, ion exchange capacity, permselectivity, current efficiency, energy consumption, and the reusability of membranes were studied. FTIR spectra confirmed formation of DL membrane decisively. FESEM and 3D-surface images also showed compact structure and smoother surface for the new DL membrane. The sodium flux exhibited a reducing trend for the DL membranes, whereas dialytic rate of copper ions showed an increasing behaviour. The modified membrane showed higher permselectivity in copper ion removal. Moreover, double-layer membranes showed high reusability potential after the regeneration. A negligible change was considered on dialytic rate for the cleaned membranes after regeneration.
