Indirect anodic oxidation applied for treatment of simulated wastewater containing Cationic Red X-GRL and Disperse Red 3B

Abstract

The treatment of simulated wastewater containing Cationic Red X-GRL (X-GRL) or Disperse Red 3B (DR-3B) dye was carried out by indirect anodic oxidation, using Ti/SnO2 electrodes as the anode. The influences of pH value, voltage, electrolysis time and sodium chloride dosage on the degradation performance were studied by single factor experiment. Furthermore the nitrogen states and UV-Vis spectra in dyes degradation were analyzed. The results showed that under the optimum condition (pH = 3, voltage = 20 V, NaCl = 2.5 g/L), the decolorization and chemical oxygen demand removal of X-GRL were 98% and 67%, respectively; and those of DR-3B were 51% and 61%, respectively. The azo double bond conjugated system in X-GRL is much more easily destroyed than the anthraquinone conjugated system in DR-3B; the aryl ring structures of them can be partially degraded.

Keywords

• Cationic Red X-GRL
• degradation
• Disperse Red 3B
• indirect anodic oxidation
• Ti/SnO2 electrode