Comparative study on photocatalytic oxidation and photolytic zonation for the degradation of pesticide wastewaters

Photocatalytic oxidation and photolytic zonation have been employed to remove carbendazim, a commonly used fungicide The effect of catalyst dosage, ozone dosage, and initial solution pH on the reaction was investigated In the photocatalytic oxidation process, the optimum catalyst dosage and pH were found to be 1 g/L and 4, respectively. In the photolytic zonation process, the optimum ozone dosage was 048 g/h and pH was 9 The pseudo first order rate constants achieved were 0 0212 min(-1) for photolytic zonation and 0 0103 min(-1) for photocatalytic oxidation. Both treatment processes were compared based on the pesticide removal and mineralization The results showed that photolytic zonation performed better with 98% removal and 85.4% mineralization was achieved, whereas only 85% removal and 62.2% mineralization in photocatalytic oxidation after a treatment time of 3 h