岷沱江标准下AAO+DNBF与Phoredox工艺TN达标应用对比OACSTPCD

More wastewater treatment plants(WWTP)upgrading and new expansion of three-stage denitrification biological filter(DNBF)process under the standard of Minjiang and Tuojiang River.DNBF has the limit of nitrogen removal TN≤3 mg/L advantage,but there are activated sludge,SS,etc.caused by the filter media slate and biological clogging and other common problems.The secondary biochemical Phoredox process can achieve deep denitrification NO3--N＜2 mg/L by adding carbon source,which fully exploits the denitrification capacity of the secondary biological treatment section and simplifies the denitrification process,but there are fewer domestic engineering cases.A WWTP in Sichuan as an example of AAO+DNBF and Phoredox two processes for nitrogen removal effect of comparison,and combined with the principle of process nitrogen removal,design parameters,the actual treatment of water,TN effluent water quality,carbon source selection and dosage,etc.,and found that the addition of an external carbon source under the circumstances of the two processes could be achieved to meet the standard for TN.Phoredox process was adapted to high cost-effective composite carbon source with lower denitrification rate,and it had the advantages of saving engineering investment and lower cost of carbon source(20 000 m3/d of water treated in the second phase,saving 8.99 million yuan of DNBF construction investment,and 567.61 t of carbon source per year,which was about 688.2 thousand yuan).The new project of wastewater treatment with TN as the most difficult point can adopt Phoredox enhanced nitrogen removal process,and the upgrading project can adopt AAO tandem AO section solution.