Technical help: Can denitrification occur under strict anaerobic conditions?

This post was last edited by zzjgo on 2011-10-28 09:04. Reply to 1# luyafei414: I think a small amount of denitrification can be carried out. I have a question: why does your aerobic effluent still need to go into a UASB? Is your aerobic process mainly used for nitrification?

Reply to 2# zzjgo: The total nitrogen level in the aerobic treatment effluent does not meet the standards

It mainly depends on your aerobic effluent parameters; it is valid as long as they are within the specified range. The general process is denitrification after nitration.

Your ORP data control is different as well: good oxidation is necessary for proper nitrification, and only then can denitrification occur with an appropriate amount of nitrate nitrogen; they are proportional to each other. Of course, there is also the control of DO in the aerobic tank.

Denitrification should be possible under strictly anaerobic conditions; otherwise, how could short-term nitrification take place? It’s just that the efficiency of denitrification under strictly anaerobic conditions is not very high.

Currently, micro-oxygen aeration is quite popular; by controlling the DO level, nitrification can be regulated, thereby enabling so-called short-cut nitrification-denitrification processes that allow for simultaneous phosphorus and nitrogen removal – this is achieved by keeping the DO level in the aerobic tank below 0.3. Regarding ORP control, it is best to maintain the value at -200 in the anaerobic tank and at 400 in the aerobic tank. The process in our facility is pre-denitrification – anaerobic stage – aerobic nitritation – aerobic nitrification; nitritation effluent is recycled for ammoxidation, nitrification effluent is recycled for denitrification, and the effluent from the secondary sedimentation tank is recycled for denitrification and ammoxidation. The COD level is around 400, NH3-N is around 300, BOD is 200, and SS is 150; the treatment performance is good.