Xd. Hao et al., CONDITIONS AND MECHANISMS AFFECTING SIMULTANEOUS NITRIFICATION AND DENITRIFICATION IN A PASVEER OXIDATION DITCH, Bioresource technology, 59(2-3), 1997, pp. 207-215
Citations number
31
Categorie Soggetti
Energy & Fuels","Biothechnology & Applied Migrobiology",Agriculture
Simultaneous nitrification and denitrification in a Pasveer oxidation
ditch was studied. The purpose was to evaluate the performances of bot
h nitrification and dentrification in oxidation ditches, and to pursue
some possible approaches to enhance nitrogen removal. Almost complete
nitrification was observed under normal conditions, but when DO<1.0 m
g/l andior T<4 degrees C, nitrification was profoundly affected. Also
because of low temperature, transient nitrite accumulation (up to 6.7
mg N/l) appeared on two occasions. It was concluded that for nitrifica
tion there was a strong capacity to absorb shock nitrogen loading. How
ever denitrification was unstable and poor; the average efficiency of
nitrogen removal was only 45% during a study period of almost 10 month
s. The bottleneck to denitrification was attributed to the lack of sta
ble anoxic zones and carbon compounds available to denitrifiers. Sever
al technical approaches are strongly proposed to improve denitrificati
on. (C) 1997 Elsevier Science Ltd.