THERMOPLASTIC STABILIZATION OF MSW COMBUSTOR ASH

High-density polyethylene (HDPE) and polystyrene (PS) resins were used to encapsulate municipal solid waste (MSW) combustor ash. Ash:plastic cylinders containing up to 70% ash were produced using a mix, melt, a nd compaction technique. Compressive strength of the ash:plastic cylin ders varied with resin type and generally decreased with increasing as h content. Toxicity characteristic leaching procedure (TCLP) regulator y leaching tests conducted on both whole and fragmented ash:plastic cy linders showed that the metal contents of the leachates did not exceed regulatory limits for toxicity. In addition, lead and cadmium were no t detected in leachates from distilled-deionized water tank leaching s tudies. Sodium leaching provided a valuable tool for determining the e xtent of ash encapsulation within the ash:plastic cylinders. Results o f this study show that thermoplastic stabilization of refuse-derived f uel (RDF) combustor ash can produce physically strong cylinders that e ffectively encapsulate the ash particles resulting in significant redu ctions in the potential for contaminant leaching.