Control of COD/N ratio for nutrient removal in a modified membrane bioreactor (MBR) treating high strength wastewater.
A modified membrane bioreactor (MBR) system has been developed to evaluate the efficiency of nutrient removal in treating synthetic high strength water. This study examined the effect of influent COD/N ratio on this system. Results showed that above 95.0% removal efficiencies of organic matter were achieved; indicating COD removal was irrespective of COD/N ratio. The average removal efficiencies of total nitrogen (TN) and phosphate (PO(4)(3-)-P) with a COD/N ratio of 9.3 were the highest at 90.6% and 90.5%, respectively. Furthermore, TN removal was primarily based on simultaneous nitrification and denitrification (SND) process occurred in the aerobic zone. Decreased COD/N ratios to 7.0 and 5.3, TN removal efficiencies in steady-states were 69.3% and 71.2%, respectively. Both aerobic SND and conventional biological nitrification/denitrification contributed to nitrogen removal and the latter played dominant effect. PO(4)(3-)-P-release and uptake process ceased in steady-states of COD/N 7.0 and 5.3, which decreased its removal efficiency significantly.
Fu
Zhimin
Z
Key Laboratory of Industrial Ecology and Environmental Engineering, MOE, School of Environmental and Biological Science and Technology, Dalian University of Technology, Dalian, PR China. fuzhimin2004@yahoo.com.cn
Yang
Fenglin
F
Zhou
Feifei
F
Xue
Yuan
Y
D019149:Bioreactors / Q000382:microbiology*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007220:Industrial Waste / Q000517:prevention & control*; D008567:Membranes, Artificial; D009584:Nitrogen / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D012722:Sewage / Q000382:microbiology*; D014462:Ultrafiltration / Q000295:instrumentation; D014874:Water Pollutants, Chemical / Q000378:metabolism*
D007220:Industrial Waste; D008567:Membranes, Artificial; D012722:Sewage; D014874:Water Pollutants, Chemical; D009584:Nitrogen; D010100:Oxygen