Shedding Light on Photocatalysis

Photocatalysis is the use of light to activate a catalytic material. This technology is of interest because laboratory studies indicate that photocatalysis can completely oxidize numerous organic contaminants in both water and air streams near or at room temperature. However, several constraints on this process have limited its commercial applications. At present, it appears that there are viable commercial opportunities for employing photocatalysis in specific niche markets (e.g., industrial hygiene applications). The original hope of employing photocatalysis as a general end-of-pipe remediation technology that could be employed in a single-pass reactor operating at relatively high flow rates (e.g., as an in-line treatment unit in HVAC systems) appears more problematic, although this application is being pursued. Ongoing research into the use of combined treatment systems (e.g., carbon adsorption/photocatalysis) may provide an alternative route for utilizing photocatalytic reactors in HVAC systems.