Air Cleaning Method using Photo Fenton Reaction in Gas-Liquid Contactor

Removal of gaseous volatile organic compounds (VOCs) in indoor air by the photo Fenton reaction using a gas-liquid two-phase photoreactor was investigated. In proposed air cleaning process, the removal of VOCs in the gas phase involves mass transfer with simultaneous chemical decomposition. As the first step of the process, the mass transfer of VOCs from the gas phase to the liquid phase occurs in the gas-liquid two-phase photoreactor. This is followed by the oxidative reaction due to highly-reactive hydroxyl radicals generated by the photo Fenton reaction. The decrease in dissolved VOCs concentration by the photo Fenton reaction leads to enhance the mass transfer. In this study, acetaldehyde as a model hydrophilic VOCs and toluene as a hydrophobic VOCs were used. It was found from the results of one-pass tests that 97% of gaseous acetaldehyde and 50% of gaseous toluene could be removed at the inlet acetaldehyde concentration of 1000ppbv and the inlet toluene concentration of 1000ppbv, respectively. In the proposed air cleaning process, because VOCs oxidations occur in the liquid phase, potential harmful incomplete oxidative degradation products could not be detected by PTR-MS.