Distribution and genetic diversity of functional microorganisms in different CANON reactors

► CANON reactors were started up in different conditions by different strategies. ► The genetic diversity of three kinds of functional microbes was examined. ► The species identification in five different CANON reactors had been analyzed. ► AerAOB and AnAOB were side by side on the biofilm. ► Some approaches were proposed to shorten the start-up time of CANON process.