Dechlorination of polychlorinated biphenyls, dibenzo-p-dioxins and dibenzofurans on fly ash

Dechlorination of commercial mixtures of polychlorinated biphenyls (PCB) as well as polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) on extracted and non-extracted fly ash obtained from municipal waste incine rator (MWI) was studied in closed systems under nitrogen atmosphere at temp eratures of 260 degrees C and 340 degrees C. Decomposition results (given a s the difference between PCB or PCDD/F molar amounts before and after the e xperiment (in %) due predominantly to dechlorination reactions) and detoxif ication data (expressed similarly but related to toxic PCB and PCDD/F conge ners only and given in I-TEQ units) are reported. Detoxification of Delor 1 05/80T at 260 degrees C and 340 degrees C at a loading of 0.65 wt% was 99.4 8% and 100%, respectively. The decomposition of Delor 103 at 340 degrees C and for the loading of 0.75 wt% corresponded to 99.99%. The detoxification capability of PCDD/Fs on extracted and non-extracted fly ash for loading of 130 and 264 ng/0.4 g of fly ash at 340 degrees C made 96 and 98%, respecti vely. (C) 2000 Elsevier Science Ltd. All rights reserved.