Degradação eletroquímica de corante da indústria têxtil

Abstract

This study aimed the electrochemical degradation of the dye Drimaren Red present in effluents from the textile industry, which contains the azo group in its composition, and the determination of the kinetics of degradation. Laboratory tests involved the use of pure dye solutions with a concentration of 100 mgL -1 . Electrolysis reactions were conducted in electrochemical cells containing solution 50 mL and electrodes of stainless steel, carbon steel and copper have been studied. As the supporting electrolyte, sodium sulfate salt (100 mgL -1 ) was used and the current density was 3.75 mAcm-2 . Monitoring the reduction in color was accomplished by UV-Vis spectrophotometry. The solutions and residues were analyzed by infrared spectroscopy, as well as by the quantification of total organic carbon. For the conditions of this study, it was observed electroflocculation process in which the waste initially electrocoagulated and subsequently floated due to water electrolysis. Furthermore, the electrolysis was able to degrade red dye Drimaren efficiently. The infrared spectra showed a progressive reduction of the characteristic band at about 1640 cm-1 , observed in the dye molecule under study, indicating its degradation. By total organic carbon analysis, there was a reduction of this parameter after the reaction of electrolysis, compared to the value obtained for the pure dye solution, which showed the electrochemical degradation of the dye under the conditions of this study.