Pilot study on municipal wastewater treatment by a modified submerged membrane bioreactor.
A pilot-scale modified submerged membrane bioreactor (SMBR) with the capacity of 18.1 m3d(-1) was developed on the basis of the principle of air-lift internal-loop reactor. Economical aeration intensity of the SMBR was determined as 96 m3m(-2)h(-1) according to hydrodynamic investigation. Corresponding economical air-flow rate was selected as the working air-flow rate in the long-term run. Under economical aeration intensity, the critical flux zone of the modified SMBR was as high as 30-35 Lm(-2)h(-1) when MLSS was less than 13 gL(-1). Therefore, a sub-critical flux of 30 Lm(-2)h(-1) was selected as the working membrane flux in the long-term run. Membrane fouling was effectively controlled by sub-critical flux operation and periodic on-line chemical cleaning in the long-term run. When the average influent CODCr, NH3-N and turbidity were 310 and 44.3 mgL(-1) and 161 NTU, respectively, the average permeate were 38.5 and 19.5 mgL(-1) and 0.96 NTU under hydraulic retention time (HRT) was only 2.8 h. Corresponding removal was 86, 58.2 and 99.4%. DO deficiency caused by high MLSS was demonstrated as the main reason for low NH3-N removal.
Wei
Chunhai
C
Environment Simulation and Pollution Control State Key Laboratory, Department of Environmental Science and Engineering, Tsinghua University, Beijing, China.
Huang
Xia
X
Wen
Xianghua
X
D000332:Aerobiosis; D019149:Bioreactors; D005160:Facility Design and Construction; D008567:Membranes, Artificial; D010865:Pilot Projects; D012722:Sewage / Q000032:analysis; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000032:analysis; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
D008567:Membranes, Artificial; D012722:Sewage; D014874:Water Pollutants, Chemical