Pilotscale Experiment To Reduce COD Of Dyeing And Printing Wastewater Using Catalyzed Oxidation

Dyeing wastewater is one of the industrial effluent which is difficult to deal with, where there are a large varieties of dyestuffs, complex composition and great changes in water quality, so that the biodegradability of dyeing waste is poor. At present, frequently-used sewage disposal technology can reduce COD to 100 mg/L, in order to reach the (GB18918-2002) Primary A Standard——COD< 50 mg/L, we use the "Activated carbon/Catalyst+H2O2" process to make a further treatment about dyeing wastewater. Thus, we can not only reduce COD, but also reuse the waste.Sewage treatment plant A is chosen to make a pilotscale experiment. The scondary treatment effluent is water inflow of advanced treatment process. We change water inflow(HRT), backwash duration, dosage of H2O2, system running time to determine the optimal process condition. In addition, the paper sets a control group to make a further discussion of catalyst. The main contents and conclusions are as follows:1. The optimal process condition is volume concentration of H2O2 0.075%, water inflow 120 L/h; backwash cycle 6 days, backwash duration 3 hours, backwash water inflow 100 L/h, where the removal rate of COD keeps 30% stably.2. The quality of water inflow has a great influence to yielding water:COD cannot lower than 50 mg/L, reaching "the standards of Municipal wastewater treatment plant emission", until water inflow COD is lower than 70 mg/L.3. The service life of catalyst is approximately 10 months.4. The running cost of pilotscale experiment is RMB 9.45 per ton water inflow.5. Catalysis of Activated carbon/Catalyst is on the dominant position during the whole system running. The removal rate of COD is 2 times as big as normal AC process. In addition, Fe ion and Cu ion make an important part in catalysis, but we have to research the further theory of catalysis.