The denitrifying nitrogen removal experiment with low carbon to nitrogen ratio and organic loading

The performance of denitrification was investigated under the condition of the low organic loading and C/N ratio during 35d. The nitrate was acted as the electron accepter and the sodium acetate was acted as the electron donor. When the carbon loading and the C/N ratio were 0.6 kgCOD/kgVSS·d and 3.4 respectively, the NO₃-N was reduced to 1mg/L, nevertheless the NO₂-N was increased to 14.39 mg/L during 30min; the residual of NO₂-N was still 12.57mg/L after denitrifying; the degradation rate of COD and the max. denitrification rate of NO_X-N were 0.46 mgCOD/mgVSS·h and 0.099mgN/mgVSS·h respectively, and 4.6g COD was degraded for 1g nitrogen removal; and the denitrification efficiency was from 69.5% to 87.9%. The carbon source of denitrification was insufficient when the C/N ratio was 3.4.