pH Effect on Photocatalytic Degradation of Trichloroethylene by Brookite Titanium Dioxide Nanoparticles

Lily Shoff

Chemistry/Biochemistry

Oksana Love

Trichloroethylene (TCE) contamination of ground and surface waters presents many adverse health risks. It is expensive and difficult to remove TCE and other volatile organic pollutants from contaminated water efficiently and large-scale. Photochemical processes such as UV coupled with titanium dioxide nanoparticles have gained popularity in recent decades, offering promising methods of removing volatile organic compounds such as TCE from contaminated sources. Titanium dioxide exists in three crystal phases: anatase, rutile, and brookite, as well as in combinations of the three. While anatase and rutile are extensively studied photocatalysts, the photocatalytic potential of brookite is largely undocumented in literature. This study observes the degradation of TCE in the presence of brookite with UV irradiation using Gas Chromatography Mass Spectroscopy over various time intervals. The relationship between pH and the rate of degradation of TCE in the presence of brookite is also explored. The pH of solution affects many factors, such as the electrostatic interactions occurring on the catalytic brookite surface, solvent molecules, and charged radicals formed during the degradation of TCE. This experiment investigates the pH effect by comparing the degradation rate of TCE in highly acidic and basic aqueous solutions and analyzing data from photodegradation trials to find the optimal conditions for the photocatalytic degradation of TCE with brookite titanium dioxide nanoparticles. Experiments conducted in basic conditions demonstrated a higher rate of degradation of TCE with brookite, while experiments in highly acidic conditions showed a higher rate of degradation of TCE in the absence of brookite.

Jan-9-2024