Novel photocatalytic reactor for degradation of DDT in water and its optimization model

A novel photocatalytic reactor was developed to remove (1,1-bis(4- chlorophenyl)-2,2,2-trichloroethane) (DDT) from water. In the reactor, a cenosphere was used to support TiO₂ film made by means of sol-gel. Because the cenospheres were coated with TiO₂, their specific gravity was slightly increased from the original 0.6∼0.8 to 0.8∼0.9, so that they were able to be suspended in water. With the mixed operation of a bubbler, the water in the reactor was in a well-fluidized state. The bottom of the reactor is a sand filter bed, which can be used to prevent the photocatalyst from being lost. A mathematical model of the reactor has been developed in the two primary influential factors: ultraviolet (UV) light intensity and photocatalyst concentration. With such a model, the reactor can be designed more reasonably.