Complete Decomposition of 2-Propanol Using TiO2 Immobilized on a Nonwoven Fabric Under UV Light Irradiation by Adding H2O2 and O3 Microbubbles

Abstract

The degradation and mineralization of 2-propanol (IPA) in an aqueous solution were investigated using a TiO2 photocatalyst immobilized on a nonwoven fabric, both in the presence and absence of O3 microbubbles and H2O2. The influence of parameters like the H2O2/O3 molar ratio and the type of ultraviolet (UV) lamp used on the IPA degradation reaction was investigated. The main active species in IPA degradation and mineralization are thought to be hydroxyl radicals, generated as a consequence of the H2O2–O3 (peroxone) reaction, the photolysis of H2O2 and O3, and the TiO2-based photocatalytic reaction. The fastest IPA degradation rate was obtained under UV irradiation in the presence of H2O2, O3, and TiO2 immobilized on a nonwoven fabric. Because under these conditions sufficient UV light is irradiated on the catalyst surface, we found that the optimum ratio for the peroxone reaction between O3 and H2O2 did not change in our reaction system, even in the presence of the TiO2 immobilized nonwoven fabric. This means that the UV light contributes effectively to the photocatalytic reaction without interfering with the peroxone process, and that the photocatalyst does not only promote the decomposition of IPA but also the mineralization of the degradation products. We explored the influence of the base material used to manufacture the nonwoven fabric on the mineralization rate and found that the use of polyethylene terephthalate (instead of polyolefin fibers) to prepare the nonwoven fabric substantially accelerated the rates of the IPA, acetone, and total organic carbon decomposition reactions.