Dechlorination controlled polychlorinated dibenzofuran isomer patterns from municipal waste incinerators

The ability to predict polychlorinated dibenzofuran (PCDF) isomer patterns from municipal waste incinerators (MWIs) enables an understanding of PCDF f ormation that may lead to preventive measures. This work develops a model f or the pattern prediction, assuming that the chromatograph peak ratios rela tive to the total four heptachloro-dibenzofuran (H7CDF) isomers are determi ned by position-specific dechlorination kinetics from an octachloro-dibenzo furan (08CDF) parent to H7CDFs and that these probabilities can subsequentl y predict the relative concentrations of lower chlorinated isomers. Agreeme nt of PCDF isomer patterns between the model and sampled data from eight MW Is is consistent with formation of tetrachloro-dibenzofurans to H7CDFs by d echlorination from an 08CDF parent. The application of the analogous theory to predict isomer patterns of polychlorinated dibenzo-p-dioxins (PCDDs) di d not provide any significant results, which implies that the formation mec hanism of PCDDs is controlled by other factors such as condensation of prec ursors and further chlorination. This method can be a fundamental basis to develop a prediction model for total PCDFs emission and toxic equivalent va lues.