Inorganic nitrogen removal of toilet wastewater with an airlift external circulation membrane bioreactor.
Removal of inorganic nitrogen (inorganic-N) from toilet wastewater, using a pilot-scale airlift external circulation membrane bioreactor (AEC-MBR) was studied. The results showed that the use of AEC-MBR with limited addition of alkaline reagents and volumetric loading rates of inorganic-N of 0.19-0.40 kg inorganic-N/(m3 x d) helped achieve the desired nitrification and denitrification. Furthermore, the effects of pH and dissolved oxygen (DO) on inorganic-N removal were examined. Under the condition of MLSS at 1.56-2.35 g/L, BOD5/ammonia nitrogen (NH4+ -N) at 1.0, pH at 7.0-7.5, and DO at 1.0-2.0 mg/L, the removal efficiencies of NH4+ -N and inorganic-N were 91.5% and 70.0%, respectively, in the AEC-MBR. The cost of addition of alkaline reagent was approximately 0.5-1.5 RMB yuan/m3, and the energy consumption was approximately 0.72 kWh/m3 at the flux of 8 L/(m2 x h).
Li
Gang
G
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. Ligang7786@126.com
Wu
Lin-lin
LL
Dong
Chun-song
CS
Wu
Guang-xia
GX
Fan
Yao-bo
YB
D019149:Bioreactors; D006863:Hydrogen-Ion Concentration; D008567:Membranes, Artificial; D009584:Nitrogen / Q000302:isolation & purification*; D014867:Water / Q000737:chemistry*
D008567:Membranes, Artificial; D014867:Water; D009584:Nitrogen