Wastewater primary sedimentation sludge was prepared into fermentation liquid as denitrification carbon
source, and the main components of fermentation liquid was short-chain volatile fatty acids.
Meanwhile, the acetic acid and propionic acid respectively accounted for about 29.36% and 26.56% in
short-chain volatile fatty acids. The performance of fermentation liquid, methanol, acetic acid, propionic
acid and glucose used as sole carbon source were compared. It was found that the denitrification rate
with fermentation liquid as carbon source was 0.17 mg NO3
-N/mg mixed liquor suspended solid d, faster
than that with methanol, acetic acid, and propionic acid as sole carbon source, and lower than that with
glucose as sole carbon source. For the fermentation liquid as carbon source, the transient accumulation of
nitrite was insignificantly under different initial total nitrogen concentration. Therefore, the use of fermentation
liquid for nitrogen removal could improve denitrification rate, and reduce nitrite accumulation
in denitrification process.