Application of a homogeneously sulphonated polystyrene membrane in the purification of waste water

Abstract

The homogeneous sulphonation of waste polystyrene and its subsequent use in waste water purification was studied. The targeted waste was white food trays collected from roadsides, bins and waste dumps. They were shredded and sulphonated using acetyl sulphate thereby converting them into adsorbent material. The pH, electrical conductivity, water uptake, ion exchange capacity and the degree of sulphonation were evaluated for each sample produced. To confirm sulphonation the Fourier Transform Infrared Spectroscopy (FTIR) was used. The modified polymer was tested for its effectiveness in the removal of heavy metals from water. The Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-OES) was used to test for the concentrations of residual metals (chromium, cadmium and manganese) after batch adsorption experiments were carried out. The sulphonated polymer provided high purification of waste water by reducing the concentrations of cadmium from 10ppm to 2.30 ppm and manganese from 10 ppm to 1.53 ppm respectively. This is comparable to conventional adsorbents.