Biodiversity and quantification of functional bacteria in completely autotrophic nitrogen-removal over nitrite (CANON) process

► We realize a high NH4+-N removal loading in relatively low NH4+-N concentration. ► We examine the biodiversity and species identification of functional microbes. ► Population of denitrify-related bacteria changes with NH4+-N concentration's change. ► We propose some approaches in CANON's application in low NH4+-N concentration.