Abstract The polyvinyl chloride (PVC) based polyvinyl alcohol zinc oxide composite membrane was successfully prepared by solution casting technique. Membrane properties were studied in terms of water uptake, porosity, thickness, ion-exchange capacity and swelling. The physico-chemical characterization of the material was studied using Fourier transform infrared (FTIR) spectroscopy, thermogravimetry analysis (TGA), X-ray diffraction (XRD) and scanning electron microscopy (SEM) studies. The important application of this composite ion-exchange membrane is in environmental separation of heavy metal ions transport. The increasing order of transport number of cation as HgCl2<PbCl2<CdCl2.