In this work, the electro-oxidation process based on reactions with copper (cathode) and graphite (anode) electrodes, referred to in the literature as Cupro Fenton, was applied to the degradation of basic fuchsin. The real wastewater used was generated in a microbiology laboratory from practical classes, research projects, and course completion work at a university in the northwest of Rio Grande do Sul, Brazil. The results demonstrate that electro-oxidation as a standalone process is insufficient in removing the contaminant, which consequently necessitated the use of UVC light and H₂O₂. The electro-oxidation and electro-cupro Fenton processes were complementarily applied to remove the Basic Fuchsin dye (FCS-B) from the wastewater sample. Experiments were conducted at pH values of 5, 7, and 9, and current densities of 3, 6, and 9 mA cm⁻². Current density was identified as a significant parameter (p = 0.0178). The application of electro-oxidation did not satisfactorily remove the contaminant, and H2O2 and 254 nm UVC light were used as an additional source of ●OH, achieving removal rates 88.61% for COD, 86.52% for fuchsin, and 98.34% for color. Ecotoxicological tests using allium cepa suggested the presence of residual H2O2, which requires careful consideration regarding the possibility of direct environmental disposal.
Zago et al. (Thu,) studied this question.