Abstract
Highly adsorptive clay mineral-TiO2 composites were prepared by a simple sol-gel method in order to remove trichloroethylene and the intermediate products of its degradation by photocatalytic degradation and adsorption. The composite powder was obtained by the following procedure: particles of the natural clay mineral, allophone or kaolinite, were dispersed into a titanium alkoxide sol, separated from the sol after the sol-gel reaction proceeded to some extent, and then heated. Trichloroethylene was transformed into the intermediate product, phosgene, on the TiO2 during the UV irradiation. Using the composites, emission of phosgene was significantly inhibited although the degradation rate of trichloroethylene was slower than that using TiO2. The composites supported on porous filters enabled the removal of trichloroethylene in a relatively short time due to a better contact between the composites and reactants.
