Study On Coking Wastewater Treatment Process Of A~2O-MBR Composite

China’s coke production ranks first in the world, the coking industry, environmental pollution is very serious, the coking wastewater pollution of be the first to bear the brunt. Coking wastewater component is very complex, containing a variety of toxic, persistent organic pollutants, show the environmental hormone (EDCs) characteristics, its emissions, will give the environment, ecological catastrophic failure. Therefore, looking for coking wastewater treatment method with high efficiency and low cost has been the direction. Coking wastewater treatment at home and abroad, the application of A2O technology widely, but the process itself has limitations and defects, the effluent COD and ammonia nitrogen is difficult to reach. The MBR replaces the two secondary sedimentation tank in the A2O process, the treatment of coking wastewater by combined process of A2O-MBR, has strong capacity of anti shock loading, covers an area of muddy water separation characteristics of small area, high efficiency.The combined process of A2O-MBR for the treatment of coking wastewater by artificial, the different influent load, reflux ratio of nitrification, dissolved oxygen concentration, membrane module aeration intensity, running flux on removal and membrane fouling control system of pollutants were studied. The experimental results show that:in the system of water flow for 0.825 L/h, HRT for 5d, sludge return ratio is under 100% operating conditions, the system of the coking wastewater artificial (COD:2500 mg/L, NH3-N:300 mg/L) has good treatment effect, COD, ammonia nitrogen, volatile phenol, potassium thiocyanate and turbidity removal rate remained at 96.62%,85.58%,99.97%,99.94% and 99.02%; nitrified liquid recirculation system optimal ratio is 300%, the concentration of dissolved oxygen is 4.5-5 mg/L; the optimal parameters of membrane assembly operation: aeration 0.2m3/h, membrane flux was 15 L/(m2·h), and with some maintenance cleaning measures can maintain long-term stable operation to wash the membrane module.