The Technological Transformation Of The Treatment Of The Coal Chemical Wastewater By Using A/O+MBR

The process of BAF technology to treat the coal chemical wastewater of a certain company, whose flow rate is36000m3/d, doesn’t have a sufficient ability to resist the influence of upstream water quality. The removal rate of pollutants fluctuates and membrane is seriously polluted when the devices operate. The recovery time of the membrane flux is relatively short and frequent cleaning leads to the cost. All these inhibit the development of production. It is proved that using the "A/O+MBR" technology instead of BAF technology to treat waste water can improve the treatment efficiency.After adopting the "A/O+MBR" technology, the operation of the project confirms that the removal efficiency of COD、NH3-N、SS and turbidity can reach80%,、95%、90%and above95%. That reliefs the system operation load, increases the reuse efficiency of waste water, decreases the numbers of time when TDS and conductivity exceed the standards and stabilize the sludge mud volume with no significant increase. During the operation process, the MBR biofilm does not show any biological or physical fouling problem, TMP are always manageable without significant increase. It is also found that during the operation process, the ratio of B/C has a certain linear relationship with the removal rate of COD. When the ratio of B/C of influent is below0.3, the biodegradability improves significantly after the treatment of A/O technology, and the concentration of COD of MBR effluent is under20mg/L. biomass activity (VSS/SS) is related to the removal efficiency of COD and NH3-N. The increase of the ratio of VSS/SS leads to the increase of biomass activity and the removal efficiency of pollutants. When the ratio of the A pool, O pool and MBR pool is34.73%,46.29%and43.33%, the removal efficiency of pollutants can reach the standards or even above.The transformation of the project guarantees the normal operation of the treatment of wastewater in the coal chemical industry; satisfies the influent requirements for the reuse of intermediate water and has achieved the expected goal.