RECYCLED POLYMER/CLAY COMPOSITES FOR HEAVY-METALS ADSORPTION

Post-consumer plastics in the form of disposable cutlery, plates, cups, and containers for dairy products that are made of polystyrene (PS) were used to formulate polymer/clay composite materials for the purpose of using them as an adsorbent for the removal of heavy metals from waste water. The clay used in this study was a natural clay obtained from the Tabuk region in the north of Saudi Arabia. The composites were formulated by mixing 5-10 % mass fractions of clay with PS in the molten state using conventional polymer-processing equipment. Composites of virgin PS and clay were also formulated in order to compare their ability to adsorb heavy metals with that of the recycled composites. The results showed that composites based on recycled PS have a good adsorption capability in comparison with those of the virgin composites. For example, the amount of lead adsorbed per gram of adsorbent was tripled when using composites containing only 5 % of clay and 95 % of recycled PS in comparison with those with virgin PS.