Formation of polychlorinated naphthalenes on fly ash

Article abstract of DOI:10.1016/S0045-6535(98)00269-0

During the oxidative degradation of carbonaceous material on fly ash, besides PCDD/F, PCPh, PCBz, PCB, polychlorinated naphthalenes (PCN or Cl(x)N) are formed. Thermal experiments were carried out with fly ash from a municipal waste incinerator at 300°C and reaction times of 0.5 h up to 4 h. For the study an analytical method using GC/MS was developed similar to that, used in dioxin-analysis. Isomer specific identification of chloronaphthalenes formed on fly ash was realized by comparison of Cl(x)N from technical PCN- mixtures (Halowax). For quantification of the PCN formed, ¹³C- labelled PCB-standards were used as internal standards because no ¹³C- labelled PCN- compounds were available. Both, technical PCN-mixtures and PCN formed on fly ash show a characteristic pattern of Cl(x)N-congeners according to their difference in formation. Cl₂N - Cl₃N were formed most and Cl₁N - Cl₃N were also found in the gas phase in high amounts. A single isomer 1,2,3,5,6,7-Cl₆N, known as a strongly bioaccumulating and toxic PCN, is formed in higher amounts together with 1,2,3,4,6,7-Cl₆N.