title: Photodegradation of decabromodiphenyl ether adsorbed onto clay minerals, metal oxides, and sediment.
abstract: The photodebromination of decabromodiphenyl ether (BDE-209) adsorbed onto six different solid matrixes was investigated in sunlight and by irradiation with 350 +/- 50 nm lamps (four lamps at 24 W each). After 14 days of lamp irradiation, BDE-209 degraded with a half-life of 36 and 44 days, respectively, on montmorillonite or kaolinite, with much slower degradation occurring when sorbed on organic carbon-rich natural sediment (t1/2 = 150 days). In late summer and fall sunlight (40.5 degrees N, elevation 600 ft), the half-lives of BDE-209 sorbed on montmorillonite and kaolinite were 261 and 408 days, respectively. Under both irradiation schemes, no significant loss of BDE-209 occurred when sorbed to aluminum hydroxide, iron oxide (ferrihydrite), or manganese dioxide (birnessite). Upon exposure to both lamp and solar light and in the presence of montmorillonite and kaolinite, numerous lesser brominated congeners (tri- to nonabromodiphenyl ethers) were produced. Nearly identical product distribution was evident on montmorillonite and kaolinite. Dark control experiments for each mineral showed no disappearance of BDE-209 or appearance of degradation products. These results suggest that photodegradation of BDE-209 on mineral aerosols during long-range atmospheric transport may be an important fate process for BDE-209 in the environment.
authors.affiliation: Earth and Atmospheric Sciences and School of Civil Engineering, Purdue University, 550 Stadium Mall Drive, West Lafayette, Indiana 47907, USA. mahn@purdue.edu
authors.forename: Mi-Youn
authors.initials: MY
authors.lastname: Ahn
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Filley
authors.forename: Chad T
authors.initials: CT
authors.lastname: Jafvert
authors.forename: Loring
authors.initials: L
authors.lastname: Nies
authors.forename: Inez
authors.initials: I
authors.lastname: Hua
authors.forename: Juan
authors.initials: J
authors.lastname: Bezares-Cruz
mesh_terms: D000327:Adsorption; D000336:Aerosols / Q000737:chemistry; D000536:Aluminum Hydroxide / Q000737:chemistry; D000538:Aluminum Silicates / Q000737:chemistry*; D001546:Bentonite / Q000737:chemistry; D001673:Biodegradation, Environmental; D000077215:Clay; D005290:Ferric Compounds / Q000737:chemistry; D019015:Geologic Sediments / Q000737:chemistry*; D055768:Halogenated Diphenyl Ethers; D007616:Kaolin / Q000737:chemistry; D007700:Kinetics; D017895:Manganese Compounds / Q000737:chemistry; D008903:Minerals / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D010647:Phenyl Ethers / Q000032:analysis / Q000378:metabolism*; D010777:Photochemistry; D011075:Polybrominated Biphenyls / Q000032:analysis / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism
chemical_list: D000336:Aerosols; D000538:Aluminum Silicates; D005290:Ferric Compounds; D055768:Halogenated Diphenyl Ethers; D017895:Manganese Compounds; D008903:Minerals; D010087:Oxides; D010647:Phenyl Ethers; D011075:Polybrominated Biphenyls; D014874:Water Pollutants, Chemical; D001546:Bentonite; C000499:ferric oxide; D007616:Kaolin; D000536:Aluminum Hydroxide; C010902:decabromobiphenyl ether; D000077215:Clay; C016552:manganese dioxide