title: Distribution of free radicals and intermediates during the photodegradation of polychlorinated biphenyls strongly affected by cosolvents and TiO₂ catalyst.
abstract: Polychlorinated biphenyls (PCBs) pose potential ecological risk because of their high toxicity and carcinogenicity. Photodegradation, which is an important process for the removal of PCBs, is greatly influenced by the cosolvent and catalyst. Hence, it is important to explore their effects on the photodegradation behavior of PCBs. In this study, 2,4,4'-trichlorobiphenyl (PCB28) was selected as a model compound, and the effects of two typical cosolvents, namely acetone and ethanol, and TiO2 catalyst on the distributions of free radicals and intermediates were investigated. Interestingly, the TiO2 catalyst did not promote PCB28 photodegradation. Moreover, the free radical distribution was greatly influenced in the presence of the TiO2 catalyst, while was only slightly affected in its absence by the cosolvent kinds. The main photodegradation pathways are proposed on the basis of the distribution of detected intermediates, which were significantly regulated by both the cosolvent and TiO2 catalyst. The results provide novel insights into the photodegradation of PCBs and may have important implications for choosing cosolvent in desorbing soil PCBs and consequently enhancing PCBs degradation.
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China.
authors.forename: Xiangdong
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Yujun
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Wenxiu
authors.initials: W
authors.lastname: Qin
authors.affiliation: Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China.
authors.forename: Shicheng
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China. Electronic address: dmzhou@issas.ac.cn.
authors.forename: Dongmei
authors.initials: D
authors.lastname: Zhou
mesh_terms: D000096:Acetone / Q000737:chemistry; D002384:Catalysis; D004785:Environmental Pollutants / Q000032:analysis* / Q000528:radiation effects; D000431:Ethanol / Q000737:chemistry; D005609:Free Radicals / Q000032:analysis*; D010782:Photolysis; D011078:Polychlorinated Biphenyls / Q000032:analysis* / Q000528:radiation effects; D012997:Solvents / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: D004785:Environmental Pollutants; D005609:Free Radicals; D012997:Solvents; D000096:Acetone; C009495:titanium dioxide; D000431:Ethanol; C081766:2,4,4'-trichlorobiphenyl; D014025:Titanium; D011078:Polychlorinated Biphenyls
keywords: 2,4,4′-trichlorobiphenyl; Free radical; Intermediate; Photodegradation