Decolorization of textile wastewater by electrooxidation process using different anode materials: Statistical optimization

AbstractThe presence of reactive dyes in textile wastewater is a serious environmental concern due to their associated mutagenic and carcinogenic effects. The present study aims to analyze the effect of different anodic materials on the decolorization of a real textile wastewater effluent. For this purpose, four different anodic materials—TiO2‐coated platine, TiO2‐coated ruthenium dioxide (RuO2) (viz., RuO2), titanium dioxide (TiO2), and graphite—were connected, respectively, to titanium dioxide (TiO2) used as a cathode electrode. Color and cost optimization studies were performed using the response surface methodology and the Box–Behnken experimental design (BBD). According to ANOVA results, the R2 values for Pt/TiO2, RuO2/TiO2, TiO2/TiO2, and graphite/TiO2 electrode pairs were found to be 97.4%, 93.8%, 92.44%, and 92.2%, respectively, indicating a good compatibility as it is close to one. The results show that color removal efficiencies at the optimal conditions were 86.3%, 90.8%, 91.5%, and 93.6% for Pt/TiO2, graphite/TiO2, TiO2/TiO2, and RuO2/TiO2, respectively. Furthermore, energy consumption cost at the optimum conditions was also evaluated, and the results were as follows: Pt/TiO2 (0.95 €/m3), graphite/TiO2 (0.74 €/m3), TiO2/TiO2 (0.31 €/m3), and RuO2/TiO2 (0.26 €/m3). Consequently, this research paper shows that all of the tested anodic materials give satisfactory color removal efficiencies higher than 86%. When energy consumption and color removal are considered together, the use of TiO2/TiO2 and RuO2/TiO2 pairs would be preferred.Practitioner Points Anodic contribution was investigated for decolorization of textile wastewater by electrooxidation process. Graphite, TiO2‐coated Pt, TiO2‐coated RuO2, and TiO2 were used as anode materials. Highest color removal with lowest energy consumption was achieved with TiO2‐coated RuO2 anode material (93.6%).