title: Efficient degradation of contaminants of emerging concerns by a new electro-Fenton process with Ti/MMO cathode.
abstract: The performance of a new electro-Fenton process with Ti-based mixed metal oxides (Ti/MMO) cathode, a dimensionally stable electrode, is evaluated for degrading contaminants of emerging concerns (CECs) in aqueous solutions. Bisphenol A (422μgL(-1)) is completely degraded in an undivided cell using Ti/MMO as the cathode in the presence of 6.9mgL(-1) Fe(2+) within 20min under conditions of pH 4 and 25mA. Both bisphenol A degradation and H2O2 production increase with decreasing solution pH and increasing current. Ti/MMO cathode is effective for reducing O2 to H2O2 and regenerating Fe(2+) from Fe(3+). OH radicals are validated to be the predominant reactive oxygen species (ROS) contributing to bisphenol A degradation. This new electro-Fenton process is also effective for degrading bisphenol A, triclosan and ibuprofen even at a relatively high concentration of 5mgL(-1). The partial removals of total organic carbon suggest a moderate extent of mineralization. The transformation pathways of the three CECs are proposed based on the intermediates identified by HPLC and GC-MS, showing that CECs are mainly transformed to nontoxic aliphatic acids. This study demonstrates that Ti/MMO can be used as the cathode in the electro-Fenton process for degrading CECs at trace levels in waters.
authors.affiliation: State Key Lab of Biogeology and Environmental Geology, China University of Geosciences, 388 Lumo Road, Wuhan 430074, PR China; Department of Civil and Environmental Engineering, Northeastern University, 400 Snell Engineering, 360 Huntington Avenue, Boston, MA 02115, United States. Electronic address: yuansonghu622@hotmail.com.
authors.forename: Songhu
authors.initials: S
authors.lastname: Yuan
authors.forename: Na
authors.initials: N
authors.lastname: Gou
authors.forename: Akram N
authors.initials: AN
authors.lastname: Alshawabkeh
authors.forename: April Z
authors.initials: AZ
authors.lastname: Gu
mesh_terms: D001559:Benzhydryl Compounds / Q000032:analysis / Q000737:chemistry; D004563:Electrochemistry; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D010636:Phenols / Q000032:analysis / Q000737:chemistry; D017382:Reactive Oxygen Species / Q000737:chemistry; D014025:Titanium / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D006861:Hydrogen Peroxide; D007501:Iron; D010087:Oxides; D010636:Phenols; D017382:Reactive Oxygen Species; D014025:Titanium; D014874:Water Pollutants, Chemical; C006780:bisphenol A; D000098826:Bisphenol A Compounds
keywords: Contaminants of emerging concerns; Degradation; Electro-Fenton; Pathway; Ti-based mixed metal oxides