Formation of tetrahalogenated dibenzo-p-dioxins (TXDDs) by pyrolysis of a mixture of 2,4,6-trichlorophenol and 2,4,6-tribromophenol

Na, Yun-Cheol; Kim, Kang‐Jin; Park, Chansoo; Hong, Jongki

doi:10.1016/j.jaap.2007.03.002

Cited by 9 publications

(3 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Compared to the situation for PCDD/Fs, there are very few studies on the formation of PBDD/Fs. This is largely due to shortage of commercial available PBDD/Fs’ standards for quantification. ,,, Here, therefore, we conducted a direct density functional theory (DFT) kinetics study on the homogeneous gas-phase formation of PBDD/Fs from 2-BP, 2,4-DBP, and 2,4,6-TBP as precursors, which are the most widely manufactured BPs and the most abundant BPs found in waste incinerators. The primary objective of the study is to elucidate the homogeneous gas-phase formation mechanism of PBDD/Fs from BPs.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Mechanism and Direct Kinetics Study on the Homogeneous Gas-Phase Formation of PBDD/Fs from 2-BP, 2,4-DBP, and 2,4,6-TBP as Precursors

Hu²,

Xu³

et al. 2011

Environ. Sci. Technol.

View full text Add to dashboard Cite

This study investigated the homogeneous gas-phase formation of polybrominated dibenzo-p-dioxin/dibenzofurans (PBDD/Fs) from 2-BP, 2,4-DBP, and 2,4,6-TBP as precursors. First, density functional theory (DFT) calculations were carried out for the formation mechanism. The geometries and frequencies of the stationary points were calculated at the MPWB1K/6-31+G(d,p) level, and the energetic parameters were further refined by the MPWB1K/6-311+G(3df,2p) method. Then, the formation mechanism of PBDD/Fs was compared and contrasted with the PCDD/F formation mechanism from 2-CP, 2,4-DCP, and 2,4,6-TCP as precursors. Finally, the rate constants of the crucial elementary reactions were evaluated by the canonical variational transition-state (CVT) theory with the small curvature tunneling (SCT) correction over a wide temperature range of 600-1200 K. Present results indicate that only BPs with bromine at the ortho position are capable of forming PBDDs. The study, together with works already published from our group, clearly shows an increased propensity for the dioxin formations from BPs over the analogous CPs. Multibromine substitutions suppress the PBDD/F formations.

show abstract

Section: Introductionmentioning

confidence: 99%

“…This is largely due to shortage of commercial available PBDD/Fs' standards for quantification. 6,11,22,23 Here, therefore, we conducted a direct density functional theory (DFT) kinetics study on the…”

Section: ' Introductionmentioning

confidence: 99%

Mechanism and Direct Kinetics Study on the Homogeneous Gas-Phase Formation of PBDD/Fs from 2-BP, 2,4-DBP, and 2,4,6-TBP as Precursors

Hu²,

Xu³

et al. 2011

Environ. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…The gas-phase formation of PBCDD/Fs is likely to have similar mechanisms to those responsible for PBDD/F and PCDD/F productions. On the one hand, PBCDD/Fs can be formed from the combustion or high-temperature pyrolysis of the BP and CP mixture; [45][46][47][48][49] on the other hand, BCPs are also structurally similar to PBCDD/Fs and have been demonstrated to be the predominant precursors for or key intermediates in the formation of PBCDD/Fs. The dimerization of bromochlorophenoxy radicals (BCPRs) is the major pathway for the gas-phase formation of PBCDD/Fs from BCP precursors.…”

Section: Introductionmentioning

confidence: 99%