"Experimental Dechlorination Isomer Patterns of PCDFs, PCDDs, PCNs, and PCBs from their Fully Chlorinated Species" 

Fukuya Iino¹, Dennis G. Tabor², Takashi Imagawa¹, Brian K. Gullett³

¹National Institute of Advanced Industrial Science and Technology
²ARCADIS Geraghty & Miller, Inc, USA
³United States Environmental Protection Agency, USA

Organohalogen Compounds,  Vol.50 pp.447-450 (2001)

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Abstract

Dechlorination isomer patterns of polychlorinated dibenzofurans (PCDFs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated naphthalenes (PCNs) were obtained from experiments with a mixture of each fully chlorinated species and copper oxide as a dechlorination catalyst in an ampoule. We have to warn that the ampoule containing polychlorinated biphenyls (PCBs) may explode under this experimental condition. 

The experimental isomer patterns of four heptachlorodibenzofurans (H7CDFs) from octachlorodibenzofuran (O8CDF) showed the same H7CDF isomer patterns found in municipal waste incinerators (MWIs). The isomer patterns of hexachlorodibenzofurans (H6CDFs) from O8CDF were similar to those from MWIs except for 1,2,3,7,8,9- and 2,3,4,6,7,8-H6CDFs. Starting from only octachlorodibenzo-p-dioxin (O8CDD), the ratio of the two heptachlorodibenzo-p-dioxins (H7CDDs) was within the range of those normally observed from MWI samples. 

The ratio of the two heptachloronaphthalenes (HpCNs) produced from octachloronaphthalene (OcCN) at 5 min was completely opposite from the sampled data partly because of the limited supply of OcCN. The isomer patterns of nonachlorobiphenyls (NoCBs) in a quartz tube reactor with a flow of 10%O2 / N2 were barely detected under this experimental condition. A simple dechlorination mechanism cannot completely explain the isomer patterns from MWIs, but it may be one of the formation mechanisms of these organic chlorinated compounds in MWIs.

Keywords

PCDFs, PCDDs, PCNs, PCBs