You have a typical "nitrite ...
Published by Paul Sun, Consultant at Shell Oil Coompany
You have a typical "nitrite lock" phenomena, in which during the startup or temperature change or shock loading conditions, nitrite will accumulate. Nitrite concentration, when high enough, will cause inhibition of nitrite oxidation bacteria (NOB). But your influent ammonia is not too high, this transient process will pass and the change of DO may not be the cause of the nitrite reduction. But the nitrification in your system is still not complete, so keep you sludge age long and keep the feed steady and maintain DO at > 2 mg/L in both reactors. The problem should go away. You don't have to spend money to change process, I don't believe.
1 Comment
to improve this situation in our plant, we add the other sludge to this system, and the NH3-N reduction rate will be promoted rapidly(about 7~14 days), but the NH3-N will change to NO2-N,until we add the other sludge to this system the same ,but we lower the DO, and the NH3-N change to NO3-N. now we will look on the NH3-N reduction rate will be stable,in the lack of NO2-N in our aerotion tank.
Published by Lin JYH-YAN, advanced engineer at FORMOSA PETROCHEMICAL CORPORATION