PERFORMANCE OF NONCONCENTRATING SOLAR PHOTOCATALYTIC OXIDATION REACTORS .2. SHALLOW POND CONFIGURATION

A solar photocatalytic oxidation facility has been fabricated in which the destruction of 4-chlorophenol (4CP) is tested in three adjacent s hallow pond reactors. Each of the reactors has depths of 5.1, 10.2, an d 15.3 cm (2, 4, and 6 in.), respectively. It is found that 4CP is suc cessfully oxidized with the photocatalyst, titanium dioxide (TiO2), su spended in a slurry or adhered to a fiberglass mesh. The pond reactors , however, perform better with the slurry. It has also been found that the first-order rate constant for oxidation of 4CP increases with dec reasing initial concentration. For the same incident ultraviolet (UV) intensity, catalyst loading, and initial solute concentration, the oxi dation rate of 4CP is invariant provided the aperture to volume ratio is fixed. It has been determined that the 4CP solution contains suffic ient dissolved oxygen to support the photocatalytic oxidation process. Direct evidence is provided to demonstrate that the utilization of ph otons in the photocatalytic process becomes less efficient as the numb er of incident photons on the catalyst increases.