A control strategy of partial nitritation in a fixed bed biofilm reactor.
To achieve an appropriate mixture of ammonium and nitrite for anaerobic ammonium oxidation (ANAMMOX), 50% partial nitritation was optimized in a fixed bed biofilm reactor treating synthetic wastewater. Results suggested that 50% partial nitritation could be achieved by stepwise increases of influent NH4+-N at pH of 7.8±0.2, temperature of 30±1°C and dissolved oxygen (DO) of 0.5-0.8 mg l(-1). Hydraulic retention time (HRT) and influent alkalinity did significantly affect partial nitritation. At HRT 12 h, 50% partial nitritation could be kept stable, regardless of influent NH4+-N variation, by controlling the influent HCO3-/NH4+ molar ratio at 1:1. The fluorescent in situ hybridization (FISH) results indicated the abundance of evolution of ammonia-oxidizing bacteria (AOB) and the nitrite-oxidizing bacteria (NOB) coincided well with the performance of partial nitritation. Furthermore, the AOB were highly affiliated with Nitrosomonas spp. and Nitrosospira spp. dominated (64.1%) in the biofilm with a compact structure during the stable 50% partial nitritation period.
Liang
Zhiwei
Z
Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310029, PR China.
Han
Zhiying
Z
Yang
Shangyuan
S
Liang
Xinqiang
X
Du
Ping
P
Liu
Guofang
G
Yang
Yue
Y
D000468:Alkalies; D001419:Bacteria / Q000378:metabolism / Q000648:ultrastructure; D001673:Biodegradation, Environmental; D018441:Biofilms; D019149:Bioreactors / Q000382:microbiology*; D017404:In Situ Hybridization, Fluorescence; D008855:Microscopy, Electron, Scanning; D058465:Nitrification / Q000502:physiology*; D009584:Nitrogen / Q000032:analysis; D000644:Quaternary Ammonium Compounds / Q000302:isolation & purification; D013997:Time Factors; D018508:Water Purification / Q000295:instrumentation* / Q000379:methods*
D000468:Alkalies; D000644:Quaternary Ammonium Compounds; D009584:Nitrogen