Start-up and long-term operation of the Anammox process in a fixed bed reactor (FBR) filled with novel non-woven ring carriers

A novel kind of non-woven ring carriers was used to improve a fixed bed reactor (FBR) as Anammox reactor. The improved FBR was operated for about 1 year. The Anammox activity occurred on day 39. On day 367, the maximum total nitrogen removal rate reached 9.2 kg N m−3 d−1. FISH analysis showed that Anammox bacteria predominated in the mature sludge and accounted for 78% of the total bacteria. Phylogenetic analysis further showed that Candidatus Kuenenia stuttgartiensis occupied 70% of Anammox bacteria, which benefited keeping the stability of Anammox reactor. The FBR was proved to be a suitable reactor for start-up and long-term operation of Anammox process.

► The non-woven ring carriers were used to improve FBR-Anammox reactor performance.
► The FBR reactor was suitable for Anammox start-up and long-term operation.
► The max total nitrogen loading reached 10.25 kg N m−3 d−1 after 367 d operation.
► Candidatus Kuenenia stuttgartiensis was dominant species in mature sludge.