TIO2-FIXED-BED REACTOR FOR WATER DECONTAMINATION USING SOLAR LIGHT

A photocatalytic reactor using immobilized TiO2 (Degussa P25) on a gla ss plate was studied on a bench scale using solar light as the source of radiation. The influence of parameters such as the slope of the pla te, solar light intensity, flow rate and molar flow rate, as well as t he geometry of the reactor, was studied using dichloroacetic acid (DCA ) as a model compound. A linear dependence of degradation with solar l ight intensity, measured at 365 nm, was observed. Experiments with rec irculation as well as a single pass of solution suggested no mass tran sfer limitations in this system. The mineralization of DCA resulted in the production of quantitative amounts of chloride ions. An initial c oncentration of 5 mmol/L of DCA decayed to 2 mmol/L in about 2 min of irradiation. An exponential decay of degradation was observed with an increase of the molar flow rate, achieving saturation around 1.5 mmol DCA/min. Copyright (C) 1996 Elsevier Science Ltd.