title: Photocatalytic degradation of 17α-ethinylestradiol (EE2) in the presence of TiO2-doped zeolite.
abstract: Current design limitations and ineffective remediation techniques in wastewater treatment plants have led to concerns about the prevalence of pharmaceutical and personal care products (PPCPs) in receiving waters. A novel photocatalyst, TiO2-doped low-silica X zeolite (TiO2-LSX), was used to study the degradation of the pharmaceutical compound, 17α-ethinylestradiol (EE2). The catalyst was synthesized and characterized using XRD, BET surface analysis, SEM-EDAX, and ICP-OES. The effects of different UV light intensities, initial EE2 concentrations, and catalyst dosages on the EE2 removal efficiency were studied. A higher EE2 removal efficiency was attained with UV-TiO2-LSX when compared with UV-TiO2 or UV alone. The EE2 degradation process followed pseudo-first-order kinetics. A comprehensive empirical model was developed to describe the EE2 degradation kinetics under different conditions using multiple linear regression analysis. The EE2 degradation mechanism was proposed based on molecular calculations, identification of photoproducts using HPLC-MS/MS, and reactive species quenching experiments; the results showed that oxidative degradation pathways initiated by hydroxyl radicals were predominant. This novel TiO2-doped zeolite system provides a promising application for the UV disinfection process in wastewater treatment plants.
authors.affiliation: Department of Civil and Environmental Engineering, University of Maine, Orono, ME 04469, USA.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Pan
authors.affiliation: Department of Chemistry, Bowdoin College, Brunswick, ME 04011, USA.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Stemmler
authors.affiliation: Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, MA 01003, USA.
authors.forename: Hong Je
authors.initials: HJ
authors.lastname: Cho
authors.affiliation: Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, MA 01003, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Fan
authors.affiliation: School of Marine Sciences, University of Maine, Orono, ME 04469, USA.
authors.forename: Lawrence A
authors.initials: LA
authors.lastname: LeBlanc
authors.affiliation: Department of Chemistry, University of Maine, Orono, ME 04469, USA.
authors.forename: Howard H
authors.initials: HH
authors.lastname: Patterson
authors.affiliation: Department of Civil and Environmental Engineering, University of Maine, Orono, ME 04469, USA. Electronic address: aria@umit.maine.edu.
authors.forename: Aria
authors.initials: A
authors.lastname: Amirbahman
mesh_terms: D000465:Algorithms; D002384:Catalysis; D004997:Ethinyl Estradiol / Q000737:chemistry*; D017665:Hydroxyl Radical; D008855:Microscopy, Electron, Scanning; D010777:Photochemistry; D013050:Spectrometry, Fluorescence; D014025:Titanium / Q000737:chemistry*; D014466:Ultraviolet Rays; D064091:Waste Disposal Facilities; D014865:Waste Disposal, Fluid; D014961:X-Ray Diffraction; D017641:Zeolites / Q000737:chemistry*
chemical_list: D017641:Zeolites; C009495:titanium dioxide; D017665:Hydroxyl Radical; D004997:Ethinyl Estradiol; D014025:Titanium
keywords: 17α-Ethinylestradiol; Hydroxyl radical; Photodegradation; TiO(2)-doped zeolite; UV