Remediation of olfactory pollution by photocatalytic degradation process: Study of methyl ethyl ketone (MEK)

The photocatalyzed oxidation of gas-phase contaminants in air is being more and more explored regarding the possible applications: decontamination, deodorization and purification of enclosed atmospheres. In the present work, the photocatalytic degradation of a typical malodorous pollutant of indoor air: methyl ethyl ketone (MEK) has been investigated by using an annular photoreactor. The annular photoreactor was modelled by a cascade of heighten elementary continuously stirred tank reactors. The influence of several kinetic parameters such as pollutant concentration, oxygen content, humidity content and incident light irradiance has been studied. The Langmuir–Hinshelwood model has been verified for MEK. The by-products of MEK photocatalytic degradation have been identified by GC/MS and acetaldehyde was found to be the main gaseous intermediate. Acetaldehyde thus has been taken into account in the general Langmuir–Hinshelwood model to evaluate the possible competition of adsorption between acetaldehyde and MEK. A mechanistic pathway is then proposed for the photocatalytic degradation of MEK.