Carbon source plays an important role in nitrogen and phosphorus removal for municipal sewage treatment

and the deficiency of carbon source can lead to decreasing nitrogen removal and unqualified TN of effluent.To solve the problem of poor nitrogen removal capacity caused by insufficient carbon source

the experiment adopted the hydrolysis-denitrification technology

in which a combination of hydrolytic acidification and denitrification replaced anoxic-denitrification

and effectively solved the problems.As the use of the hydrolysis-denitrification technology to treat municipal sewage

NH4+-N

TN and COD of effluent all met the standard A

with removal rates of 98.0%

69.4% and 82.7% respectively.TN removal rate was 17.5% higher than the sewage treatment plant by AAO process in the same period.With BOD5/TN 3 to 5

sludge denitrification rate in the hydrolysis tank was 1.2 to 1.7 times than that in the anoxic tank

less carbon source was needed to remove the same N.When BOD5/TN was 3:1

3.5:1

4:1 and 5:1

for the removal of unit N utilization of COD by denitrification bacteria in the hydrolysis tank could be saved by 59.5%

52.2%

19.9% and 23.1% respectively

which effectively solve the problem of the lack of carbon source in the denitrification process.