title: Photocatalytic decomposition of selected estrogens and their estrogenic activity by UV-LED irradiated TiO2 immobilized on porous titanium sheets via thermal-chemical oxidation.
abstract: The removal of endocrine disrupting compounds (EDCs) remains a big challenge in water treatment. Risks associated with these compounds are not clearly defined and it is important that the water industry has additional options to increase the resiliency of water treatment systems. Titanium dioxide (TiO2) has potential applications for the removal of EDCs from water. TiO2 has been immobilized on supports using a variety of synthesis methods to increase its feasibility for water treatment. In this study, we immobilized TiO2 through the thermal-chemical oxidation of porous titania sheets. The efficiency of the material to degrade target EDCs under UV-LED irradiation was examined under a wide range of pH conditions. A yeast-estrogen screen assay was used to complement chemical analysis in assessing removal efficiency. All compounds but 17β-estradiol were degraded and followed a pseudo first-order kinetics at all pH conditions tested, with pH 4 and pH 11 showing the most and the least efficient treatments respectively. In addition, the total estrogenic activity was substantially reduced even with the inefficient degradation of 17β-estradiol. Additional studies will be required to optimize different treatment conditions, UV-LED configurations, and membrane fouling mitigation measures to make this technology a more viable option for water treatment.
authors.affiliation: Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada. Electronic address: mjarlos@uwaterloo.ca.
authors.forename: Maricor J
authors.initials: MJ
authors.lastname: Arlos
authors.affiliation: Centre for Advanced Materials Joining, Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada; Waterloo Institute of Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: Robert
authors.initials: R
authors.lastname: Liang
authors.affiliation: Centre for Advanced Materials Joining, Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada; Waterloo Institute of Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: Melisa M
authors.initials: MM
authors.lastname: Hatat-Fraile
authors.affiliation: Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: Leslie M
authors.initials: LM
authors.lastname: Bragg
authors.affiliation: Centre for Advanced Materials Joining, Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada; Waterloo Institute of Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: Norman Y
authors.initials: NY
authors.lastname: Zhou
authors.affiliation: Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: Mark R
authors.initials: MR
authors.lastname: Servos
authors.affiliation: Civil Engineering Department, University of Toronto, Toronto, Ontario M5S 1A4, Canada.
authors.forename: Susan A
authors.initials: SA
authors.lastname: Andrews
mesh_terms: D002384:Catalysis; D052244:Endocrine Disruptors / Q000737:chemistry* / Q000494:pharmacology* / Q000528:radiation effects; D004967:Estrogens / Q000737:chemistry* / Q000494:pharmacology* / Q000528:radiation effects; D017665:Hydroxyl Radical; D008027:Light; D008567:Membranes, Artificial; D010084:Oxidation-Reduction; D010316:Particle Size; D010777:Photochemistry; D014025:Titanium / Q000737:chemistry*; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000737:chemistry; D018508:Water Purification
chemical_list: D052244:Endocrine Disruptors; D004967:Estrogens; D008567:Membranes, Artificial; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D017665:Hydroxyl Radical; D014025:Titanium
keywords: Advanced oxidation process; Endocrine disrupting compounds; Estrogens; Titanium dioxide; UV-LED