Effect of Na2CO3 on the photocatalytic degradation of remazol brilliant blue R

Abstract

In the present work a study of photochemical degradation of a reactive dye (remazol brilliant blue R) by using ZnO in the presence of sodium carbonate is reported. When the decolorization of the dye was used as analytical response we observed that in the presence of carbonate the chemical structure of the chromophoric group was modified with high efficiency, resulting in almost total decolorization at reaction times of about 20 min. At the same pH value, but in the absence of sodium carbonate, the total decolorization was achieved in a time higher than 60 min. The signal on the ultraviolet region was more resistant to the photochemical process, showing degradation rates of about 95% in the presence of carbonate and 80% in the absence of them, at a reaction time of 60 min. A very resembling result was observed when the total organic carbon content was used as degradation response. Degradation higher than 80% was observed in the presence of carbonate at a reaction time of 120 min. In the absence of carbonate, degradation rates lower than 60% was observed at the same reaction time.