Comparison of Ti/BDD and Ti/SnO2-Sb2O5 electrodes for pollutant oxidation

Anodic oxidation is a promising process for degrading toxic and biologically refractory organic pollutants present in wastewater treatment. Proper selection of electrodes is the key to reach effective and economic operation. In this study, two types of electrodes, i.e. the recently developed Ti/BDD and Ti/SnO2 - Sb2O5, which is generally believed to be superior to the conventional electrodes, were compared under the same conditions. It was found that the Ti/ BDD electrode could mineralize both phenol and reactive dyes effectively. But the Ti/SnO2 - Sb2O5 electrode could only mineralize phenol. When oxidizing more refractory reactive dyes, it demonstrated very poor activity. In addition, the Ti/ BDD electrode had a service life of 264 h in an accelerated life test, but the Ti/SnO2 - Sb2O5 was irreversibly damaged within several seconds. The direct experimental comparison in the present study indicates that the Ti/ BDD electrode is much better than the Ti/SnO2 - Sb2O5 electrode for pollutant oxidation.