POLYCYCLIC AROMATIC-HYDROCARBONS (PAHS) AND MUTAGENICITY IN AIR EMISSIONS FROM THE 2-STAGE INCINERATION OF POLYSTYRENE WITH VARIOUS METALLIC SALT ADDITIVES

The yield of 14 PAHs and soots were more with BaCl2 or NaCl additive t han those without metallic chloride additives. This indicated that met allic chloride additives could promote the reaction sequence towards t he growth and coagulation reaction of soots from PS pyrolysis. When th e second-stage temperature increased to the critical temperature, blac k tar formed and the concentration of 14 PAHs was 10 mu g/g PS. Pha, F lu and Pyr were major species found among the 14 PAHs. Log K values, t he ratios between the PAHs in gas phase and the PAHs in solid phases ( per particulates weight; l/mg) increased as the stage-two pyrolysis te mperature increased. When the stage-two incineration system was contro lled at 900 degrees C as were various oxygen supplies, the maximum val ue of log K occurred at 0.0525 O-2 (nl/min) and log K value decreased as the oxygen supply increased. When oxygen supply was increased from 0 to 0.210 nl/min, the mutagenicity of particulates extracts from the PS incineration with metallic chloride additives was still more strong er.