title: Characterizing the optimal operation of photocatalytic degradation of BDE-209 by nano-sized TiO2.
abstract: Brominated flame retardants have been widely used in industry. There is a rapid growing public concern for their availabilities in the environment. Advanced oxidation process (AOP) is a promising and efficient technology which may be used to remove emerging chemicals such as brominated flame retardants. This study aims at investigating optimal operational conditions for the removal of BDE-209 using nano-scaled titanium(IV) oxide. The residual PBDE congeners after photocatalytical degradation of BDE-209 by TiO2 were analysed by gas chromatography-mass spectrometry (GC-MS). It was found that the degradability of BDE-209 by TiO2 was attributed to its photocatalytic activity but not the small size of the particles. The half-life of removing BDE-209 by TiO2 was 3.05 days under visible light. Tetra- and penta-BDEs were the major degraded products of BDE-209. Optimum conditions for photocatalytical degradation of BDE-209 was found to be at pH 12 (93% +/- 1%), 5, 10, 20 mg/L (93.0% +/- 1.70%, 91.6% +/- 3.21%, 91.9% +/- 0.952%, respectively), respectively of humic acid and in the form of anatase/rutile TiO2 (82% +/- 3%). Hence, the efficiency of removing BDE-209 can be maximized while being cost effective at the said operating conditions.
authors.affiliation: Croucher Institute for Environmental Sciences, and Department of Biology, Hong Kong Baptist University, Hong Kong SAR, China.
authors.forename: Ka Lai
authors.initials: KL
authors.lastname: Chow
authors.forename: Yu Bon
authors.initials: YB
authors.lastname: Man
authors.forename: Jin Shu
authors.initials: JS
authors.lastname: Zheng
authors.forename: Yan
authors.initials: Y
authors.lastname: Liang
authors.forename: Nora Fung Yee
authors.initials: NF
authors.lastname: Tam
authors.forename: Ming Hung
authors.initials: MH
authors.lastname: Wong
mesh_terms: D002384:Catalysis; D004785:Environmental Pollutants / Q000737:chemistry; D005411:Flame Retardants / Q000032:analysis*; D055768:Halogenated Diphenyl Ethers / Q000737:chemistry*; D006812:Humic Substances; D006863:Hydrogen-Ion Concentration; D036103:Nanotechnology; D055668:Photochemical Processes; D013472:Sunlight; D014025:Titanium / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: D004785:Environmental Pollutants; D005411:Flame Retardants; D055768:Halogenated Diphenyl Ethers; D006812:Humic Substances; C009495:titanium dioxide; D014025:Titanium; C010902:decabromobiphenyl ether