Fast Start-Up of A2N Denitrifying Phosphorus and Nitrogen Removal System

Using municipal wastewater, the fast start-up of A2Ntwo-sludge nitrification and denitrification phosphorus and nitrogen removal system was studied. In the SBR reactor, the nitrification bio film was first cultured with continuous aeration, and then the nitrosobacteria was screened with the help of intermittent aeration. On the 43th day bio film enriched with nitrification bacteria could be got, in another SBR reactor, adopting the first anaerobic / aerobic and then anaerobic / anoxic way to culture the denitrifying phosphorus removal bacteria which using nitrite as electron acceptor, on the 58th day, target species could be obtained, followed by joint operation of two reactors. By debugging, A2N two-sludge system can be successful start up on the 20th. The COD of effluent was 20 ~ 25mg / L, concentration of NH4+ was 5 ~ 7mg/ L, and the concentration of PO43- was 0.3 ~ 0.5mg / L, the removal rates reached 90% to 93%, 95% to 97%, 94% to96%, respectively.