title: Simultaneously photocatalytic treatment of hexavalent chromium (Cr(VI)) and endocrine disrupting compounds (EDCs) using rotating reactor under solar irradiation.
abstract: In this study, simultaneous treatments, reduction of hexavalent chromium (Cr(VI)) and oxidation of endocrine disrupting compounds (EDCs), such as bisphenol A (BPA), 17α-ethinyl estradiol (EE2) and 17β-estradiol (E2), were investigated with a rotating photocatalytic reactor including TiO₂ nanotubes formed on titanium mesh substrates under solar UV irradiation. In the laboratory tests with a rotating type I reactor, synergy effects of the simultaneous photocatalytic reduction and oxidation of inorganic (Cr(VI)) and organic (BPA) pollutants were achieved. Particularly, the concurrent photocatalytic reduction of Cr(VI) and oxidation of BPA was higher under acidic conditions. The enhanced reaction efficiency of both pollutants was attributed to a stronger charge interaction between TiO₂ nanotubes (positive charge) and the anionic form of Cr(VI) (negative charge), which are prevented recombination (electron-hole pair) by the hole scavenging effect of BPA. In the extended outdoor tests with a rotating type II reactor under solar irradiation, the experiment was extended to examine the simultaneous reduction of Cr(VI) in the presence of additional EDCs, such as EE2 and E2 as well as BPA. The findings showed that synergic effect of both photocatalytic reduction and oxidation was confirmed with single-component (Cr(VI) only), two-components (Cr(VI)/BPA, Cr(VI)/EE2, and Cr(VI)/E2), and four-components (Cr(VI)/BPA/EE2/E2) under various solar irradiation conditions.
authors.affiliation: Korea Institute of Energy Research, New and Renewable Energy Research Division, Hydrogen Laboratory, 152 Gajeong-ro, Yuseong-gu, Daejeon 305-343, South Korea; Yonsei University, Department of Chemical and Biomolecular Engineering, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-749, South Korea.
authors.forename: Youngji
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Korea Institute of Energy Research, New and Renewable Energy Research Division, Hydrogen Laboratory, 152 Gajeong-ro, Yuseong-gu, Daejeon 305-343, South Korea.
authors.forename: Hyunku
authors.initials: H
authors.lastname: Joo
authors.affiliation: Korea Army Academy at Young-Cheon, Department of Chemistry and Environmental Science, 135-1 Changhari, Kokyungmeon, Young-cheon, Gyeongbuk 770-849, South Korea.
authors.forename: Namguk
authors.initials: N
authors.lastname: Her
authors.affiliation: University of South Carolina, Department of Civil and Environmental Engineering, Columbia, SC 29208, USA.
authors.forename: Yeomin
authors.initials: Y
authors.lastname: Yoon
authors.affiliation: Kookmin University, School of Civil and Environmental Engineering, 77 Jeongneung-ro, Seongbuk-gu, Seoul 136-702, South Korea.
authors.forename: Jinsik
authors.initials: J
authors.lastname: Sohn
authors.affiliation: Korea University, Department of Environmental Engineering, Sejong 339-700, South Korea.
authors.forename: Sungpyo
authors.initials: S
authors.lastname: Kim
authors.affiliation: Korea Institute of Energy Research, New and Renewable Energy Research Division, Hydrogen Laboratory, 152 Gajeong-ro, Yuseong-gu, Daejeon 305-343, South Korea. Electronic address: jyoon@kier.re.kr.
authors.forename: Jaekyung
authors.initials: J
authors.lastname: Yoon
mesh_terms: D001559:Benzhydryl Compounds / Q000032:analysis; D002384:Catalysis; D002857:Chromium / Q000737:chemistry* / Q000528:radiation effects; D052244:Endocrine Disruptors / Q000737:chemistry* / Q000528:radiation effects; D004958:Estradiol / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D043942:Nanotubes; D010636:Phenols / Q000032:analysis; D010777:Photochemistry; D012993:Solar Energy; D013472:Sunlight; D014025:Titanium / Q000737:chemistry; D014865:Waste Disposal, Fluid; D014877:Water Pollution, Chemical / Q000032:analysis; D060753:Water Quality; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D002857:Chromium; D052244:Endocrine Disruptors; D004958:Estradiol; D010636:Phenols; D014025:Titanium; C009495:titanium dioxide; C074702:chromium hexavalent ion; C006780:bisphenol A; D000098826:Bisphenol A Compounds
keywords: 17α-ethinyl estradiol (EE2); 17β-estradiol (E2); Bisphenol A (BPA); Cr(VI) reduction; Endocrine-disrupting compounds (EDCs); Rotating reactor; Solar irradiation; Ti mesh; TiO(2) nanotubes