Executive Summary

A variety of common products, as well as industrial processes and natural sources (i.e. terrestrial plants) generate Volatile Organic Carbon species (VOC’s). These volatile compounds can negatively impact human health both directly, and indirectly through the formation of O3 under outdoor conditions. VOC’s are of particular concern in indoor environments, where concentrations can accumulate due to indoor emission sources. This report describes the photocatalytic degradation of formaldehyde and methanol, two common VOC’s, by TiO2 impregnated tiles. The same plug-flow reactor used for previous NOX experiments was used for the formaldehyde and methanol tests (Land et al., 2008). A standardized aqueous solution of formaldehyde and methanol was used to produce measurable gas phase concentrations. The extended UV illumination of the tiles resulted in a 50 % reduction in formaldehyde, and a 68 % reduction in methanol. The deposition velocities (or the photocatalytic velocities, PV) were estimated for both VOC’s. The PV for formaldehyde was 0.021 cm s-1, and the PV for methanol was 0.026 cm s-1. These PV values are slightly higher than the mean value determined for NO from prior lab experiments which was 0.016 cm s-1. The results suggest that the TiO2 tiles could effectively reduce specific VOC levels in indoor environments. I. Introduction and Backgroun