with the A2/O process,a pilot test system for enhancing biological nitrogen and phosphorus removal by using the A2/O-membrane bioreactor(A2/O-MBR)was constructed and used to treat municipal wastewater.

An auxiliary medium was made by mixing shredded waste tyres,ethylene vinyl acetate(EVA) copolymer and zeolite in certain proportion and added into aerobic zone of A2/O process to investigate the influence on nitrogen removal efficiency.

Experimental study on nitrogen and phosphorus removal was conducted in A2/O process using landfill leachate as external carbon source.

In order to give a solution to the instable biological phosphorus removal in A~2/O oxidation ditch process and the difficult achievement of the standard for effluent phosphorus,chemical phosphorus removal based on the A~2/O oxidation ditch process was added in the anaerobic zone to increase phosphorus removal efficiency.

This paper introduces the features of coking wastewater and the present situation of the treatment of coking wastewater in China, and expounds the mechanism, process and results of A2/O method of treating the coking wastewater.

The A2/O method was put forward in this paper which was used to replace the departed,then the water quality could meet the request of the first level B standard in 《Pollutant Discharge Standard of City Treatment Plant》,and the water source probum was also sloved.

This paper investigates the removal effect of organic matters and nitrogen of A~2/O process at different HRT,DO,return ratio,temperature,C/N and so on.