A　laboratory-scale　completely　autotrophic　nitrogen　removal　over　nitrite　(CANON)　process　was　operated　in　a　municipal　wastewater　treatment　plant　(WWTP).　Sewage　effluent　treated　by　the　anaerobic/oxic　(A/O)　process　and　was　used　to　operate　a　WWTP　to　obtain　the　initial　substance　for　the　start-up　of　a　CANON　filter　reactor.　On　the　48th　day,　the　ammonia　removal　rate　was　measured　at　greater　than　90%　in　successive　10　d　samples　and　the　nitrogen　removal　rate　was　greater　than　70%.　The　CANON　filter　was　successful　at　start　up.　From　the　49th　to　the　129th　day,　the　dissolved　oxygen　in　the　reactor　was　maintained　at　fairly　low　concentration　of　0.2-0.5　mg·L-1.　The　effluent　contained　nearly　no　ammonia　and　the　maximum　total　nitrogen　(TN)　concentration　was　15.6　mg·L-1,　which　exceeded　the　national　Class　1A　Discharge　Standards　for　pollutants　from　municipal　wastewater　treatment　plants.　Nitrite　oxidizing　bacteria　(NOB)　proliferated　excessively　in　the　reactor.　Backwash　was　implemented　on　129th,　169th　and　213th　days.　The　nitrogen　removal　rate　was　more　than　70%　for　a　long　time　and　TN　concentration　in　effluent　was　below　12　mg·L-1.　The　nitrogen　concentration　in　effluent　fitted　the　national　Class　1A　Discharge　Standards　and　the　NOB　were　effectively　inhibited.　These　results　show　that　backwash　has　negligible　on　the　structure　of　filter　and　its　impact　on　the　thickness　of　the　bio-membrane　and　its　functional　bacteria　was　small,　however,　it　is　capable　of　effectively　inhibiting　the　activity　of　the　NOB.　Periodically　backwashing　can　be　utilized　as　an　engineering　application　to　maintain　stable　operation　of　the　CANON　process.　©　2017,　Science　Press.　All　right　reserved.