DESTRUCTION OF PHENOL IN WATER WITH SUN, SAND, AND PHOTOCATALYSIS

The photocatalytic degradation and oxidation to carbon dioxide of aqueous phenol solutions have been studied using natural sunlight in geometries simulating shallow ponds. The photocatalyst was titanium dioxide freely suspended in the solution or immobilized on sand or silica gel. Photodegradation rates were approximately three times faster with the free suspension than with the immobilized catalyst under the same conditions, and were dependent on the time of the year and the time of the day. The seasonal variation correlated roughly with seasonal solar irradiance tabulations for the UV component of the spectrum. For 10 ppm of phenol the maximum rate of solar degradation resulted in a decrease in concentration to 10 ppb in less than 80 min with total mineralization in 110 min. Maintaining the same geometry, 30 L of solution covering 1 m2 Would degrade to the same extent.