Treatment Of Industrial Wastewater By Chlorine Dioxide Catalytic Oxidation

As a kind of water treatment medicament,chlorine dioxide(ClO₂) is wildly used in water treatment field because of its excellent functions. Utilizing its strong oxidizability to treat refractory wastewater is one of the primary uses of ClO₂ in water treatment.This paper mainly studies the chlorine dioxide catalytic oxidation technology to treat industrial wastewater, including the catalyst preparation, as well as the catalytic oxidation of caffeine wastewater, wastewater containing cyanide and dyeing wastewater, and chlorine dioxide chemical oxidation system and the chlorine dioxide catalytic oxidation system were compared to verify the effect of chlorine dioxide catalytic oxidation, emphasizing the selection of appropriate catalyst to reduce the activation energy is a chlorine dioxide treatment of industrial wastewater in the main directions of research.The results showed that: The COD of 14999.4 mg / L of caffeine wastewater, the reaction of chemical oxidation treatment with chlorine dioxide is slow and poor performance, COD removal rate of only 57.3%; However, under the appropriate catalyst (catalyst preparation conditions as follows: 4% concentration of impregnation solution, calcination temperature is 350℃, catalyst calcination time is 3h), COD removal rate could reach 76.4%. At the same level of COD removal rate increased by 40%, The oxidant costs also reduces one time.Its process conditions: solution pH controlled at 3 4, chlorine dioxide dosage is 160mg 180mg ClO₂ / L wastewater, reaction time 45min.The CN- of 1600mg / L of cyanide-containing waste water, pH=9¹0, [ClO₂] / [CN-] = 6, reacting 60 min were the efficient and the removal rate of close to 100% by ClO₂ chemical oxidation treatment; However, under the appropriate catalyst (3.5 % concentration of impregnation solution, calcination temperature is 350℃, catalyst calcination time is 3h).The removal rate of CN- will be close to 100%.when the solution pH controlled at 9 10, reacting 60 min, [ClO₂] / [CN-] = 4, In comparison, the removal rate of CN- is higher than chemical oxidation by 2 percentage points.The 2 000-fold for the color, CN-value of 600 mg / L of dyeing wastewater, decolor rate and the COD removal rate were about 76% and 75% , when the dyeing wastewater was treated by chlorine dioxide catalytic oxidation, decolor rate and the COD removal rate were about 95% and 85%, the best experimental conditions as follows: chlorine dioxide dosage of 8 mL100 mL dyeing wastewater, reaction time was 45 min, solution pH = 9.Therefore, no matter from the technical or economic aspects, the evaluation of indicators showed that the catalytic oxidation is superior to chemical oxidation process. On this basis, this paper also discussed the life of the catalyst, regeneration methods, and chlorine dioxide catalytic oxidation mechanism. And provided a theoretical basis for the chlorine dioxide catalytic oxidation technology in the practical and scientific aspects of the further development.