Study of nitrogen balance and enhanced SND control technology in anaerobic-anoxic-anaerobic oxidation ditch system

To achieve the SND enhanced nitrogen removal and energy-saving operation of the anaerobic-anoxic-aerobic oxidation ditch plant in Chongqing City, the SND phenomenon was studied by using material balance calculation and analysis of activated sludge floe size, and then had strengthened SND regulation on that basis. The results shows that: The material balance calculation and analysis of activated sludge method of combining particle size analysis of the phenomenon of SND is feasible; the strengthening of control after running SND, total nitrogen removal rate from 89.2% to 93.1%, tons of water at power consumption from 0.35 kW·h/m³ down to 0.26 kW·h/m³, remove the unit COD, total nitrogen, total phosphorus daily power consumption has decreased greatly, the annual power consumption savings of about 49 myriad kW·h; control before and after, The average activated sludge floe size increased from 58.02 μm to 102.58 μm, shows the formation of micro environmental effects of SND.