QUANTUM/THERMAL CATALYTIC DESTRUCTION OF CHLOROALIPHATIC POLLUTANTS ON METAL OXIDES USING CONCENTRATED SUNLIGHT

POLLUTION OF WASTEWATER BY TOXIC ORGANICS IS A GLOBAL PROBLEM. THIS RESEARCH IS DESIGNED TO DEVELOP A COST- AND ENERGY-EFFICIENT METHOD OF WATER PURIFICATION USING IRRADIATION OF SEMICONDUCTOR PARTICLES BY CONCENTRATED SOLAR ENERGY. THE ENERGY OF THE ENTIRE SOLAR SPECTRUM ABSORBED BY THE PARTICLES IS USED TO PROMOTE QUANTUM/THERMALPROCESSES TO DEGRADE THE POLLUTANTS WITH HIGH EFFICIENCY. PHASE I WILL INVESTIGATE THE MINERALIZATION OF CHLOROHYDROCARBONS SUCH AS CARBON TETRACHLORIDE, TRICHLORETHYLENE, AND TRICHLOROETHANE TO CARBON DIOXIDE AND HYDROCHLORIC ACID. DILUTE AQUEOUS SOLUTIONS OF THE CHLOROALIPHATICS MIXED WITH TITANIUM DIOXIDE PARTICLES WILL BE ILLUMINATED WITH AN UNFILTERED SOLAR SIMULATOR WITH LIGHT INTENSITY UP TO 40 SUNS. EXPECTED TEMPERATURES WILL BE ON THE ORDER OF 200 DEGREES CENTIGRADE. THE PROGRESS OF THE REACTION WILL BE MONITORED BY MEASURING THE FORMATION RATE OF HC1 AND THE DECREASE OF THE STARTING ORGANIC. THE EFFECT ON THE DECOMPOSITION RATE OF TEMPERATURE, ORGANIC POLLUTANT AND SEMICONDUCTOR CONCENTRATION, AND LIGHT INTENSITY WILL BE MEASURED. THE EFFECT ON THE RATE AND PRODUCT DISTRIBUTION OF MODIFYING THE TIO2 WITH PLATINUM COATING AND/OR INORGANIC DOPANTS WILL BE ASSESSED. PHASE I WILL PROVIDE THE TECHNICAL DATA BASE FOR DESIGN AND TESTING OF A PHOTOCHEMICAL REACTOR USING NATURAL CONCENTRATED SOLAR ILLUMINATION IN PHASE II.