Abstract

The leaching behavior of the sulfonate group (SO3 -H+) and the heavy metals exchanged by the sulfonated polystyrene (SPS) were investigated using the Toxicity Characteristic Leaching Procedure (TCLP). The SPS used for the TCLP tests was prepared by the direct method of adding sulfuric acid to recycled Styrofoam and was then subjected to batch ion exchange test with ion-simulated wastewater. Experimental results from the TCLP tests yielded the following results: the heavy metals exchanged leached out with concentrations greater than the regulatory standards for wastewater; and the sulfonate group or the active site remained in the ion exchange material. The results suggest that the SPS from recycled Styrofoam will only slow down the release of heavy metals to the receiving environment and will act as a temporary holder of heavy metals. The SPS leached the heavy metals but the sulfonate group remained in the polystyrene unit making it available to trap heavy metals again.