Study On Treatment Process Of Simulated Printing And Dyeing Wastewater With Membrane Bioreactor

Printing and dyeing industrial wastewater is Dyestuff wastewater features high colority, complicated constituents, high salinity, poor biochemical property, great variation in quality and quantity, large biological toxicity leading to quite a low management rate. With the development of dye industry and the printing and dyeing process technology, the structure of dye is more stable so that treatment of decoloration is much more difficult. At present, treatment of dyestuff wastewater has been one of conundrum of industrial wasterwater treatment all over the world. The result of the conventional physical and biochemical methods for the treatment of the dyeing wastewater is not that good as we wish. An immersed membrane bioreactor system will be applied in this research for treating the simulation printing and dyeing industrial wastewater, hoping that we can confirm the best technics condition so that we can get rid of the CODCr and chroma effectively. It will be a guide for the application of MBR system in the actual printing and dyeing wastewater.Experiments showed that the removal rates of CODcr reached to 93% and removal rates of colority reached to 40% by domesticated activated sludge. During the normal operation of the system, preliminary explored optimum operating conditions in which MBR treated simulated dye wastewater treatment. When hydraulic retention time( HRT) was 8h, aeration rate was 0.4m3/h, sludge concentration greater than 3200 mg/L, and PH was 8.5, the reactor treatment effect was best.During the normal operation of the system, preliminary explored the influencing factors of membrane fouling. Increasing the hydraulic retention time and aeration intensity can obviously reduce membrane fouling. The mixture viscosity and membrane fouling had strong correlation(R2 = 0.9465). As the viscosity increasing, the membrane pollution was more serious.Test also examined the different cleaning methods of membrane flux recovery, using backwashing + NaOH 、backwashing + HCl and backwashing + NaClO. The backwashing + NaClO cleaning method of cleaning cycle was short, high recovery of membrane flux.