臭氧催化氧化深度处理工艺模式的对比研究

Comparison study on process modes of ozone catalytic oxidation in advanced treatment of dyeing wastewater

对国内南北两家印染厂的二级生化出水进行臭氧催化氧化中试研究,优化了序批式和连续流两种工艺模式下的反应条件,得到了最佳臭氧投加量和反应时间;在最优反应条件下对比了两种工艺模式的处理效果及运行费用。结果表明,在二级生化出水COD值为60~90 mg/L的北方工厂,最佳臭氧投加量为30 mg/(L·h),处理出水COD均达到40 mg/L以下时,序批式模式和连续流模式的最佳反应时间分别为30 min和90 min;在二级生化出水COD值为100~130 mg/L的南方工厂,最佳臭氧投加量为40 mg/(L·h),处理出水COD均达到55 mg/L以下时,序批式模式和连续流模式的最佳反应时间分别为60 min和90 min;达到同等出水条件下,序批式模式的运行费用(北方工厂:0.335元/m^(3)水;南方工厂:0.702元/m^(3)水)低于连续流模式(北方工厂:0.776元/m^(3)水;南方工厂:0.996元/m^(3)水);7 d稳定运行验证了两种工艺模式的稳定性。

In this paper, a pilot test of ozone catalytic oxidation of secondary effluents from 2 different dyeing plants in China was carried out with the same device. The optimal ozone doses and reaction times were obtained in sequential batch mode(SBM) and continuous flow mode(CFM), respectively. The COD removal efficiencies and operating costs of the two process modes were compared under the optimal reaction conditions. The results showed that the optimal ozone dose is 30 mg/(L·h) when the influent COD of the plant located in northern China is 60~90 mg/L, and optimal reaction time of SBM and CFM is 30 min and 90 min, respectively, when the effluent COD is below 40 mg/L. The optimal ozone dose is 40 mg/(L·h) when the influent COD of the plant located in southern China is 100~130 mg/L, and optimal reaction time of SBM and CFM is 60 min and 90 min, respectively, when the effluent COD is below 55 mg/L. For the same effluent COD condition, the direct operation cost of SBM(north plant: RMB 0.335 per cubic water;south plant: RMB 0.702 per cubic water) lower than the CFM(north plant: RMB 0.776 per cubic water;south plant: RMB 0.996 per cubic water). The stability of the two process modes was verified by 7 days stable operation, and the ozone catalytic oxidation process with two different modes all can be successfully applied to the advanced treatment of dyeing wastewater.