Correlation of polychlorinated naphthalenes with polychlorinated dibenzofurans formed from waste incineration

Isomer composition of polychlorinated naphthalenes (PCNs) was measured for municipal waste incinerator fly ash samples and for emission samples produc ed from soot and copper-deposit experiments conducted at the United States Environmental Protection Agency (US-EPA). Two types of PCN isomer patterns were identified. One pattern contained specific PCN isomers in which chlori ne atoms are substituted as if the peri(alpha-) position were dechlorinated from the higher chlorinated PCNs one by one. In another pattern, the isome rs had a tendency for the chlorine atoms to assume successive positions on the naphthalene ring, which may be caused by specifically oriented chlorina tion. Some of these isomers increased, together with several polychlorinate d dibenzofuran (PCDF) and a few polychlorinated dibenzo-p-dioxin (PCDD) iso mers, The ratios between some specific PCN, PCDF, and PCDD isomers measured for the fly ash samples agree with those obtained from the soot and copper -deposit experiments. The observations suggest that these isomers were form ed possibly from de novo synthesis utilizing the carbon structure contained in soot under the catalytic effect of a copper compound. Typical isomers f or PCNs and PCDFs produced from incineration emissions were identified. (C) 2001 Elsevier Science Ltd. All rights reserved.