[Analysis of CANON Process Start-up with Fiber Carrier]

A CANON reactor with fiber carrier was started up by seeding nitrification sludge and ANAMMOX sludge to study the operating characteristics of a fiber carrier. The results showed that total nitrogen removal load rose from 0.09 kg·(m³·d)^-1 to 0.9 kg·(m³·d)^-1 and remained steady in the 85th day. This indicated that fiber carrier is beneficial to the accumulation of sludge, and the reactor can maintain a higher biomass. The DO in the reactor reached 5 mg·L^-1 with the enrichment of microorganisms, biofilm thickening, and the improvement of the reactor's ability. The DO gradient of the biofilm from the outside to the inside was 0.32-0 mg·L^-1, which could be obtained by a microelectrode. It was shown that the permeability of oxygen to the biofilm decreased, and the amount of nitrifying microorganisms decreased with biofilm thickening. The quantitative PCR results showed that the abundance of ANAMMOX was an order of magnitude more than before. The abundance of AOB increased slightly, while the abundance of NOB stayed at a relatively low level.