Photocatalyzed oxidation of crude oil residue by beach sand

Crude-oil residue in contact with beach sand and air was observed to undergo photocatalytic oxidation on exposure to light from a high pressure mercury vapor lamp. The kinetics of the heterogeneous reaction were of zero order in the mass of organic material present. Carbon dioxide was the oxidation product. No dark reaction occurred. The beach sand used contained magnetite and ilmenite as minor constituents. These materials are known to have catalytic properties for hydrocarbon oxidation. The results point to a self-cleaning process provided by the natural environment for the photocatalytic removal of crude-oil contamination from sandy beaches.