Modeling of indoor air treatment using an innovative photocatalytic luminous textile: Reactor compactness and mass transfer enhancement

Indoor air pollution is a complex problem that involves a wide range and diversity of pollutants that threaten human health. In this context, significant efforts must be made to improve the quality of indoor air. It is therefore important to start controlling the sources of indoor pollution. However, where eliminating or minimizing sources of emissions is not technically feasible, technologies to reduce them should be used. The present work deals with the photocatalytic depollution of hospitals indoor air, using a continuous photocatalytic process. In order to get closer to real conditions, two model pollutants representing the indoor air of hospitals were chosen as targets; chloroform (CHCl3) and glutaraldehyde (C5H8O2). The photocatalytic oxidation of VOCs alone and their mixture (binary mixing system) has been studied on a pilot scale. Indeed, the experiments were carried out in a continuous planar reactor using a new technology based on the TiO2/optical fiber photocatalyst. The effects of experimental conditions such as air flow rate (4-12 m(3).h(-1)), VOCs inlet concentration (4-40 mg.m(-3)) and humidity levels (5-90%) were pointed out. The photocatalytic effect of the OF-TiO2 composite was found to be improved under UV irradiation as compared to TiO2. The presence of water molecules in small amounts (less than RH = 30%) can promote the degradation process due to the formation of *OH radicals. Biomolecular Langmuir-Hinshelwood model including mass transfer step has been developed to represent the process behavior. Reusability test show that the optical fiber -based photocatalysts presented good photocatalytic activities towards CHCl3/C5H8O2 removal.