Study on Electro-Catalytic Oxidation of Simulant Dye Wastewater Using Ti/SnO₂-Sb₂O₃, Ti/SnO₂-Sb₂O₃ /PbO₂-Fe Anodes

Abstract

The Ti/SnO 2 -Sb 2 O 3 and Ti/SnO 2 -Sb 2 O 3 /PbO 2 -Fe electrodes were prepared by thermal decomposition method. Using these two electrodes as anodes, two electro-catalytic oxidation processes were introduced to treat three simulant dye wastewaters, which respectively prepared by the dyes of acid orange II, alizarin red and methylene blue thrihydrate. The results show that these dyes with 100mg/L concentration were degraded by the optimal electrodes. When the current density was 75mA/cm 2 , the electrolyte concentration was 12g Na 2 SO 4 /L, and the degradation time was over 60 minutes, the removal ratio of acid orange II was around 80%, alizarin red was above 65%, and methylene blue thrihydrate was just 45% or so. The results that the removal rates of different dyes were different were explained based on the dyes chemistry structure. It was obtained that the chromophoric group of dye is more complex, the degradation process is more difficult.