PAH emission from waste ion-exchange resin incineration

A batch-type, controlled-air incinerator was used for the treatment of three kinds of waste ion-exchange resin. The concentration and composition of 21 individual PAHs (polycyclic aromatic hydrocarbons) in raw material, flue gas (gas and particle phases) and ash were determined. Stack flue-gas samples were collected by a PAH stack-sampling system. Twenty one individual PAHs were analyzed primarily by gas chromatography (GC) and a gas chromatography/mass spectrometer (GC/MS). The total-PAH concentration in flue gas and its composition in ash averaged 1782 μg/m 3 and 6.00 μg/g, respectively. Phase distribution of the total-PAHs in the flue gas was mainly in the gas phase (92%) with a mean-concentration of 1640 μg/m 3, while the total-PAH concentration in the particle phase (averaged 42 μg/m 3) only represented a small fraction (9%) of the total-PAH mass collected. The PAH concentration in the stack flue-gas averaged ∼ 990 orders of magnitude higher that that in the ambient air. Phase distribution of the total-PAHs in the flue gas was very similar to that in the ambient air, being primarily in the gas phase. For the individual PAHs, lower molecular weight PAHs were dominant in the gas phase, while higher molecular weight PAHs 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 mass fraction (averaging 99.5%). For PAH output-mass distribution from the incineration, lower molecular weight PAHs were primarily emitted by the stack gas phase, while higher molecular weight PAHs were discharged at a significant fraction by flue-gas particulate and ash. The blank-incineration results of diesel combustion showed that most of the PAHs in the diesel had been destroyed during the combustion process and that there was, therefore, a significant fraction of PAH emission due to the thermal-synthesis process during the waste ion-exchange resin combustion.