INFLUENCE OF HCL AND CL-2 ON THE FORMATION OF POLYCHLORINATED DIBENZO-P-DIOXINS DIBENZOFURANS IN A CARBON/FLY ASH MIXTURE/

Formation of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorina ted dibenzofurans (PCDF) from carbon on incinerator fly ash was invest igated using HCl and Cl-2 as a chlorinating agent. The formation proce eds roughly at an equal rate with both gases. These results do not sup port the theory that chlorination reactions on the fly ash surface tak e place through free Cl-2 generated by the Deacon reaction. Once forme d, PCDD/F remain adsorbed on the fly ash surface until ca. 350 degrees C; at ca. 400 degrees C, the major part of these compounds has evapor ated from the fly ash to the gas phase.