One-step start-up and subsequent operation of CANON process in a fixed-bed reactor by inoculating mixture of partial nitrification and Anammox sludge

The feasibility of one-step start-up of CANON process in a FBR by inoculating mixture of partial nitrification and Anammox sludge as well as its subsequent operation performances were investigated in the present study. The FBR was operated for around 3 months. The CANON process was quickly started up within 21 days. The max total nitrogen (TN) removal rate reached 183.61 g m(-3) d(-1) with the TN removal efficiency of 91.81% on day 95. The CANON process exhibited a good capability for resistance to loading shock and restoration from the unstable state. The mature CANON biofilms displayed a morphology of aggregates and had porous and microporous structure. The structural characteristics of the biofilms were conducive to improve the transferring of substrates and products. AOB and Anammox bacteria absolutely predominated in the mature biofilms and furthermore established a balanced interaction relationship. The microbial community structure contributed to the relatively stable operation performances. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

By inoculating a mixture of partial nitrification and Anammox sludge in a fluidized bed reactor, the CANON process was successfully started up in one step and exhibited good operational performance. The mature CANON biofilms had a favorable structure, with AOB and Anammox bacteria dominating and establishing a balanced interaction relationship, contributing to the maintenance of stable operation performance.