Study on Enhanced Denitrifying Phosphorus Removal from Domestic Sewage with Low Carbon Source

To address the poor performance of nitrogen and phosphorus removal from domestic sewage with low carbon source(COD/TN5 and COD200 mg/L),a reactor which combines external sludge recycle for side-stream phosphorus removal,alkaline decomposition of excess sludge and enhanced denitrifying phosphorus removal was developed.The reactor was operated in alternating aerobic and anoxic modes.The results showed that the system achieved stable nitrogen and phosphorus removal efficiency when the influent COD,TN,NH3-N,TP,C/N and C/P were 151 mg/L,31.37 mg/L,24.80 mg/L,5.72 mg/L,4.81 and 26.99,respectively.The average concentrations of COD,TN,NH3-N and TP in the effluent were 20.63 mg/L,13.25 mg/L,0.68 mg/L and 0.10 mg/L,respectively.The average removal rates were 86.31%,57.80%,97.26% and 98.18%,respectively.