Formation of heavy metal species during PVC-containing simulated MSW incineration

The effect of PVC-derived chlorine on heavy metal emissions in MSW incinera tion was investigated using a tubular furnace and simulated MSW spiked with PVCs and heavy metals (Cd, Cr, Cu, and Zn). The molar ratio of the chlorin e content to that of the heavy metal (Cl/M ratio) was varied from 3-200 as one parameter. The results indicated that the major species found in the fl y ash were chlorides of alkaline and alkali-earth metals, whereas those ide ntified in the bottom ash were MgSiO3, SiO2 and some complex aluminates and silicates. The emission of heavy metals and/or their compounds, with extre me and medium volatility, tended to be enhanced within the lower Cl/M range , whereas those with a refractory volatility were likely to be affected wit hin the higher Cl/M range. However, those with an extremely refractory vola tility were less affected by an increase of the Cl/M ratio. The variation o f speciation and partitioning in MSW combustion as affected by the Cl/M rat io are discussed.