[Effects of carbon source types on denitrification performance at low temperature].
To investigate the responding behavior of denitrifying bacteria to different carbon source (i.e., methanol, ethanol, sodium acetate, sodiumpropionate, glucose, domestic wastewater and endogenous carbon source), several batch experiments using the sludge from the Carrousel oxidation ditch were carried out at 15.4 degrees C +/- 0.8 degrees C. The results from sodium acetate feeding experiment show the highest maximum specific denitrification rate (MSDR), which is 6.51 mg/(g x h). However, the denitrificaion yield, which is 0.48, is at lowest level and an obvious accumulating of nitrite is observed. Compared to the other sole carbon source, a lower MSDR, 0.91 mg/(g x h) is shown when methanol is used as carbon source, which also suggests that the sufficient adaptation time should be promised for denitrifying bacteria. When the reactor is operated without exogenous carbon source, denitrifying bacteria can use the endogenous carbon source as electron donor for denitrification, but the specific denitrification rate is at lowest level accordingly. The MSDR value of 3.63 mg/(g x h) is obtained with fermented domestic wastewater feeding, which is equivalent to the MSDR attained from the test using VFAs as carbon source. Though the MSDR decreases a lot at low temperature, external carbon source addition improves the denitrification performance to some extent definitely.
Key Laboratory for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, China. yinfangfang8@emails.bjut.edu.cn
Fang-fang
FF
Yin
Shu-ying
SY
Wang
Xue-ye
XY
Ang
Hong-xun
HX
Hou
Yong-zhen
YZ
Peng
Wei
W
Wang
D000085:Acetates / Q000378:metabolism; D001421:Bacteria, Anaerobic / Q000378:metabolism / Q000502:physiology*; D001673:Biodegradation, Environmental; D019149:Bioreactors; D002244:Carbon / Q000378:metabolism*; D003080:Cold Temperature; D009584:Nitrogen / Q000302:isolation & purification / Q000378:metabolism*; D010084:Oxidation-Reduction; D014865:Waste Disposal, Fluid / Q000379:methods*
D000085:Acetates; D002244:Carbon; D009584:Nitrogen