Dehalogenation of polychlorinated biphenyls and polybrominated diphenyl ethers using a hybrid bioinorganic catalyst.
The environmentally prevalent polybrominated diphenyl ether (PBDE) #47 and polychlorinated biphenyls (PCBs) #28 and #118 were challenged for 24 hours with a novel biomass-supported Pd catalyst (Bio-Pd(0)). Analysis of the products via GC-MS revealed the Bio-Pd(0) to cause the challenged compounds to undergo stepwise dehalogenation with preferential loss of the least sterically hindered halogen atom. A mass balance for PCB #28 showed that it is degraded to three dichlorobiphenyls (33.9%), two monochlorobiphenyls (12%), and biphenyl (30.7%). The remaining mass was starting material. In contrast, while PCB #118 underwent degradation to yield five tetra- and five trichlorinated biphenyls, no less chlorinated products or biphenyl were detected, and the total mass of degraded products was 0.3%. Although the Bio-Pd(0) material was developed for treatment of PCBs, a mass balance for PBDE #47 showed that the biocatalyst could prove a potentially useful method for treatment of PBDEs. Specifically, 10% of PBDE #47 was converted to identifiable lower brominated congeners, predominantly the tribrominated PBDE #17 and the dibrominated PBDE #4, 75% remained intact, while 15% of the starting mass was unaccounted for.
Harrad
Stuart
S
School of Geography, Earth and Environmental Sciences and School of Biosciences, The University of Birmingham, Edgbaston, Birmingham, UKB15 2TT. S.J.Harrad@bham.ac.uk
Robson
Matthew
M
Hazrati
Sadegh
S
Baxter-Plant
Victoria S
VS
Deplanche
Kevin
K
Redwood
Mark D
MD
Macaskie
Lynne E
LE
D045285:Desulfovibrio desulfuricans / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry; D055768:Halogenated Diphenyl Ethers; D006842:Hydrocarbons, Brominated / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D010647:Phenyl Ethers / Q000737:chemistry*; D011078:Polychlorinated Biphenyls / Q000737:chemistry* / Q000378:metabolism; D012989:Soil Pollutants / Q000737:chemistry* / Q000378:metabolism
D055768:Halogenated Diphenyl Ethers; D006842:Hydrocarbons, Brominated; D010647:Phenyl Ethers; D012989:Soil Pollutants; C511295:2,2',4,4'-tetrabromodiphenyl ether; C070055:2,3',4,4',5-pentachlorobiphenyl; D010165:Palladium; C081766:2,4,4'-trichlorobiphenyl; D011078:Polychlorinated Biphenyls