Application of a congener-specific debromination model to study photodebromination, anaerobic microbial debromination, and FE0 reduction of polybrominated diphenyl ethers.
A model was used to predict the photodebromination of the BDE-203, 197, 196, and 153, the major components of the octa-polybrominated diphenyl ether (PBDE) technical mixture, as well as BDE-47, and the predicted results were compared to the experimental results. The predicted reaction time profiles of the photodebromination products correlate well with the experimental results. In addition, the slope of the linear regression between the measured product concentrations of the first step of the photodebromination products and their enthalpies of formation was found to be close to their theoretical value. The photodebromination results of the octa-BDE technical mixture were compared with anaerobic microbial debromination results and were found to be the same in both experiments. The debromination pathways of technical octa-BDE mixture were identified and BDE-154, 99, 47, and 31 were found to be the most abundant hexa-, penta-, tetra-, and tri-BDE debromination products, respectively. In addition to photodebromination and anaerobic biodebromination, the model prediction was also compared to the zero-valent iron reduction of BDE-209, 100, and 47 and the same debromination products were observed. Good correlation was observed between the photodebromination rate constants of fifteen PBDE congeners and their calculated lowest unoccupied molecular orbital (LUMO) energies, indicating that PBDE photodebromination is caused by electron transfer. Furthermore, the rate constants for the three different PBDE debromination processes are controlled by C-Br bond dissociation energy. With the model from the present study, the major debromination products for any PBDE congener released into the environment can be predicted.
Zeng
Xia
X
Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, USA.
Massey Simonich
Staci L
SL
Robrock
Kristin R
KR
Korytár
Peter
P
Alvarez-Cohen
Lisa
L
Barofsky
Douglas F
DF
D000693:Anaerobiosis; D001419:Bacteria / Q000378:metabolism*; D055768:Halogenated Diphenyl Ethers / Q000737:chemistry* / Q000378:metabolism*; D007501:Iron / Q000737:chemistry*; D010084:Oxidation-Reduction; D010777:Photochemistry
D055768:Halogenated Diphenyl Ethers; D007501:Iron
J Chromatogr A. 2006 Aug 18;1124(1-2):157-66
16824536
Environ Toxicol Chem. 2008 Dec;27(12):2427-35
18613751
Environ Sci Technol. 2004 Jun 1;38(11):3119-25
15224744
Chemosphere. 2002 Feb;46(5):583-624
11999784
Environ Sci Technol. 2004 Apr 1;38(7):2075-81
15112809
Anal Chem. 2005 Apr 1;77(7):1979-87
15801727
J Chromatogr A. 2005 Feb 18;1065(2):239-49
15782970
Environ Health Perspect. 2001 Mar;109 Suppl 1:49-68
11250805
Environ Sci Technol. 2008 Apr 15;42(8):2845-52
18497133
Water Res. 2003 Feb;37(3):551-60
12688689
Chemosphere. 2006 Jun;64(2):311-7
16442150
Environ Sci Technol. 2004 Jan 1;38(1):127-32
14740727
Environ Sci Technol. 2005 Feb 15;39(4):1078-83
15773480
Appl Environ Microbiol. 2007 Apr;73(8):2513-21
17308182
Environ Sci Technol. 2004 Aug 1;38(15):4149-56
15352454
Environ Sci Technol. 2004 Feb 15;38(4):945-56
14998004
Environ Sci Technol. 2005 Apr 1;39(7):2280-6
15871265
Environ Sci Technol. 2006 Jul 15;40(14):4429-34
16903281