Study on photocatalytic water treatment by using immobilized nanotubular TiO2

Abstract

The study focused on the application of water treatment in two ways using immobilized TiO2. First, the enhanced oxidation of organic pollutant, methylene blue (MB), was conducted using a newly designed rotating photoelectrocatalytic reactor consisting of TiO2 nanotubes/Ti lath and Ti lath as the photoanode and cathode, respectively, for applying electrical potential under UV irradiation. The effect of various parameters including conductivity, applied electrical potential (voltage), UV light intensity and rotating speeds on the degradation efficiency of organic pollutant is discussed. This study provided an idea for the application of a rotating photoelectrocatlytic process (PECP) to water treatment. Second, the performances of photocatalytic reactors of the small and scale-up rotating and flat types were evaluated to investigate the treatment of new emerging contaminants such as bisphenol A (BPA), 17α-ethynyl estradiol (EE2), and 17β-estradiol (E2) that are known as endocrine disrupting compounds (EDCs). The major parameters affecting the photocatalytic activities of the nanotubular TiO2 (NTT) were evaluated for the rotating reactors. In the extended outdoor tests with the scale-up photocatalytic reactors and NTT, it was confirmed from the four representative demonstrations that an excellent rotating-reactor performance is consistently shown in terms of the degradation of the target pollutants under solar irradiation.