Sunday, April 15, 2018
4:00 – 5:00 p.m.
Auditorium between building 4 & 5, level 0
Simultaneous Photocatalytic Degradation of Bisphenol A and Disinfection Using Visible Light Driven Magnetically Separable Photocatalysts
Presented by Professor Irene M.C. Lo, Chair Professor of Civil and Environmental Engineering Director of Environmental Engineering and Management Program, Hong Kong University of Science and Technology (HKUST).
Bio:
Professor Irene M. C. Lo is currently a Chair Professor in the Department of Civil and Environmental Engineering and Director of Environmental Engineering and Management Program at The Hong Kong University of Science and Technology (HKUST). She has been joining HKUST since 1992. Prof. Lo is an elected Academician of the European Academy of Sciences and Arts (EASA). She is the first Hong Kong scholar inducted into the EASA. She is an elected Fellow of the Hong Kong Institution of Engineers (FHKIE), and elected Fellow of the American Society of Civil Engineers (FASCE). She received her Ph.D. degree in Civil (Environmental) Engineering from the University of Texas at Austin in 1992. She is also Adjunct Professor of Tongji University, Tianjin University, Jilin University and Harbin Institute of Technology in China. She had been Visiting Professor of Technical University of Denmark and the University of Wisconsin at Madison. Prof. Lo was the recipient of the 2004 ASCE James Croes Medal, the 2007 ASCE Samuel Arnold Greeley Award, the 2008 EWRI Best Practice-Oriented Paper Award, the 2009 ASCE Wesley W Horner Award, and the 2012 ASCE EWRI Best Practice-Oriented Paper Award. Prof. Lo has held 3 Patents, edited 7 technical books, and published over 270 SCI journal articles and conference papers with citation of 9000+ and H-index of 50. Her research areas include magnetic nano-particles and nano-photocatalysts for environmental applications; pollutant migration in soils; food waste and solid waste treatment and management; and remediation technologies for river sediment, contaminated soils and groundwater.
Abstract:
Bisphenol A (BPA), one of the representative endocrine disruptors which interferes with function of endocrine systems in humans and wild life, is used in large quantities worldwide in polycarbonate plastics and epoxy resins production. BPA is detected in natural waters and sewage with unsatisfactory removal through conventional sewage treatment. It also forms disinfection byproducts after chlorination, thereby posing even higher risks on human health. Therefore, an innovative treatment technology which is capable of simultaneous BPA removal and bacteria disinfection without using chlorination is desired. Photocatalysis is an environmentally friendly treatment technology, but the traditional photocatalysts are only activated by UV light and their separation from water/wastewater is difficult due to their nano-size. In this study, magnetic separable photocatalysts have been developed by combining superparamagnetic nanoparticles (Fe3O4@SiO2) with modified TiO2 (TiO2/Fe3O4@SiO2) for degradation of BPA under visible light irradiation. Different combinations of TiO2/Fe3O4@SiO2 through doping and co-doping (using Fe or/and N) and Ag deposition, were synthesized and comparatively tested. Under visible light irradiation, BPA was totally removed by Fe,N-TiO2/Fe3O4@SiO2 after 120 min, whereas 16% and 35% of BPA were removed by Fe-TiO2/Fe3O4@SiO2 and N-TiO2/Fe3O4@SiO2, respectively. Ag deposition on Fe,N-TiO2/Fe3O4@SiO2 further enhanced its photocatalytic activity. A complete removal of BPA can be achieved using Ag/Fe,N-TiO2/Fe3O4@SiO2 after 60 minutes of visible light irradiation. Since Ag/Fe,N-TiO2/Fe3O4@SiO2 has the best BPA photocatalytic degradation performance, its photocatalytic disinfection performance was further investigated. Photocatalytic disinfection of E. coli (as a model organism) showed that a complete disinfection can be achieved by Ag/Fe,N-TiO2/Fe3O4@SiO2 after 45 minutes of visible light irradiation. Overall, Ag/Fe,N-TiO2/Fe3O4@SiO2 shows a promising property for simultaneous photocatalytic degradation of BPA and disinfection.