Effects of COD/N ratio and DO concentration on simultaneous nitrification and denitrification in an airlift internal circulation membrane bioreactor.
The effects of chemical oxygen demand and nitrogen (COD/N) ratio and dissolved oxygen concentration (DO) on simultaneous nitrification and denitrification (SND) were investigated using an airlift internal circulation membrane bioreactor (AIC-MBR) with synthetic wastewater. The results showed that the COD efficiencies were consistently greater than 90% regardless of changes in the COD/N ratio. At the COD/N ratio of 4.77 and 10.04, the system nitrogen removal efficiency became higher than 70%. However, the nitrogen removal efficiency decreased to less than 50%, as the COD/N ratio shifted to 15.11. When the operating DO concentration was maintained at 1.0 mg/L in AIC-MBR, a satisfying SND was achieved. Either low or high DO concentration could restrain SND.
Meng
Qingjuan
Q
Key Laboratory of Industrial Ecology and Environmental Engineering, MOE, School of Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024, China. mqj.2000@163.com
Yang
Fenglin
F
Liu
Lifen
L
Meng
Fangang
F
D019149:Bioreactors / Q000382:microbiology*; D004305:Dose-Response Relationship, Drug; D008567:Membranes, Artificial; D009566:Nitrates / Q000737:chemistry* / Q000378:metabolism; D009584:Nitrogen / Q000737:chemistry* / Q000378:metabolism; D010100:Oxygen / Q000737:chemistry* / Q000378:metabolism; D014462:Ultrafiltration / Q000295:instrumentation; D014865:Waste Disposal, Fluid / Q000379:methods*; D018508:Water Purification / Q000379:methods
D008567:Membranes, Artificial; D009566:Nitrates; D009584:Nitrogen; D010100:Oxygen