Degradation of refractory wastewater by chlorine dioxide oxidation

The ClO2 chemical oxidation system and ClO2 catalytic oxidation system are studied in this paper. The results show that pH=6 similar to 8, 1000mg ClO2/L wastewater, reacting 60min are the most efficient and economical, when treating Acid Brilliant Scarlet GR dyestuff wastewater, the COD of which is 3500mg/L, by ClO2 chemical oxidation. The COD removal ratio exceeds 50%, and the oxidation index (COD removal amount/ClO2 used amount) is 2.3. When treating the wastewater by catalytic oxidation which is composed of ClO2 and special catalyst, pH approximate to 2, 800mg ClO2/L wastewater, reacting 45 similar to 60min are the most efficient and economical. The COD removal ratio exceeds 80%, and the oxidation index (COD removal amount/ClO2 used amount) is 3.5. The cost of oxidant removing 1 kg COD is (sic)3.7. The effect is superior to that of ClO2 chemical oxidation apparently. The study indicates that ClO2 catalytic oxidation is an efficient method to treat refractory wastewater and it'll have a broad prospect.