Bioaccumulation characteristics and the evolution of nitrogen removal related functional bacteria and genes in biofilm-granular sludge anammox process under low dissolved oxygen stress

In order to explore the effects of low dissolved oxygen (DO) on the nitrogen removal performance of anammox process, characteristics of biofilm and granular sludge, bacterial structure and nitrogen removal functional genes, a laboratory scale upflow carrier biofilm-anammox granular sludge system was constructed. At the end of the experiment (175d), granular sludge (GS) samples and biofilm (BF) samples were taken for metagenomic sequencing. The reactor can keep good performance in the process of operation under 175d low DO condition.