Electrodegradation of Direct Black 22 in Textile Effluents Using Graphite and Copper Electrodes

The textile industry is responsible for generating high volumes of effluents, with persistent compounds such as dyes in their composition. In order to treat these substances, electrochemical advanced oxidation processes (EAOPs) are an alternative due to the high degradation rates. Thus, this work evaluated the degradation of direct black 22 textile dye (DB22) in aqueous solution (AS) and textile effluent (TE) through the anodic oxidation process. The operating condition that provided the highest percentage of degradation (96.00%) in 30 min was the system that used the electrolyte individually (NaCl 0.025 mol‧L−1), with the graphite and copper electrodes separated by 3 cm. The kinetic data obtained presented a degradation profile corresponding to a pseudo first order model. For the textile effluent, 93.00% degradation was obtained for the DB22 dye, with a reduction of 73.82% of COD. Thus, the proposed process presented satisfactory results in the treatment of the dye in different aqueous matrices using low-cost and high availability electrodes that have not yet been used for this purpose.