PAH EMISSION FROM WASTE ION-EXCHANGE RESIN INCINERATION

A batch-type, controlled-ah incinerator was used for the treatment of three kinds of waste ion-exchange resin. The concentration and composi tion of 21 individual PAHs (polycyclic aromatic hydrocarbons) in raw m aterial, flue gas (gas and particle phases) and ash were determined. S tack flue-gas samples were collected by a PAH stack-sampling system. T wenty one individual PAHs were analyzed primarily by gas chromatograph y (GC) and a gas chromatography/mass spectrometer (GC/MS). The total-P AH concentration in hue gas and its composition in ash averaged 1782 m u g/m(3) and 6.00 mu g/g, respectively. Phase distribution of the tota l-PAHs in the flue gas was mainly in the gas phase (92%) with a mean-c oncentration of 1640 mu g/m(3), while the the total-PAH concentration in the particle phase (averaged 42 mu g/m(3)) only represented a small fraction (9%) of the total-PAH mass collected The PAH concentration i n the stack flue-gas averaged similar to 990 orders of magnitude highe r than that in the ambient air. Phase distribution of the total-PAHs i n the flue gas was very similar to that in the ambient air, being prim arily in the gas phase. For the individual PAHs, lower molecular weigh t PAHs were dominant in the gas phase, while higher molecular weight P AHs were associated with the particulate. Of the PAHs from three input sources (diesel, ambient air and waste ion-exchange resins) entering the incinerator, diesel was found to contain the highest total-PAH mas s fraction (averaging 99.5%). For PAH output-mass distribution from th e incineration, lower molecular weight PAHs were primarily emitted by the stack gas phase, while higher molecular weight PAHs were discharge d at a significant fraction by flue-gas particulate and ash. The blank -incineration results of diesel combustion showed that most of the PAH s in the diesel had been destroyed during the combustion process and t hat there was, therefore, a significant fraction of PAH emission due t o the thermal-synthesis process during the waste ion-exchange resin co mbustion.