Photodegradation of Organics with Titanium Oxide/Hydrogen Peroxide Catalyst System in Microreactor and Its Application in Environmental Analysis
A microreaction system based on microfluidic chip for photodegradation of organic pollutants and environmental analysis with TiO2/H2O2 catalyst system has been developed. In this system, a porous TiO2 layer was immobilized on the inner wall of the microchip, a UV-LED was employed as the light source, H2O2 acts as both electron acceptor and oxidant in the photodegradation of methylene blue(MB) process. Under the condition of incident light intensity of 80 mW/cm2, flow rate of 1000 μL/h, CH2O2 8% and effective residence time of 19 s, the degradation rate of 0.2 mmol/L MB reached to 99.6%. The method was applied for the environmental analysis with quelate Cd(Ⅱ)-Fulvic acid and Zn(Ⅱ)-Fulvic acid as a model system. The voltammetric wave of Cd(Ⅱ) and Zn(Ⅱ) was effectively suppressed in the presence of Fulvic acid in excess. Significant acceleration of the recovery of the Cd(Ⅱ) and Zn(Ⅱ) signal after UV irradiation was observed, and complete recovery of the Cd(Ⅱ) and Zn(Ⅱ) signal was achieved after a photoreaction time of 96 s in the photoca-talytic microreactor.