Effects of Organic-Matter-Induced Short-Term Stresses on Performance and Population Dynamics of Anammox Systems

To investigate the effects of different types and concentrations of organic matter on anaerobic ammonium oxidation (anammox), the effects of short-term stresses induced by organic matter on anammox-based nitrogen removal and the associated microbial community were evaluated by adding different organic matter (e.g., glucose, acetic acid, sodium acetate, methanol, and phenol) and concentrations (e.g., 20-250 mg COD/L) into anammox batch reactors (serum bottles) with 46 h. Results indicated that the addition of glucose, acetic acid, and sodium acetate (i.e., at concentrations ranging from 20 to 250 mg COD/L) promoted nitrite removal. Methanol was the most potent inhibitor on ammonium removal, while phenol inhibited ammonium removal even at a low concentration (e.g., 20 mg COD/L). The microbial community structure and composition under organic matter addition was illustrated by high-throughput Miseq sequencing analyses. The phylum Firmicutes was predominant in all samples, followed by Planctomycetes, Proteobacteria, and Chloroflexi, respectively. Planctomycetes, which was related to anammox bacteria, including Candidatus Jettenia and Candidatus Brocadia, dramatically decreased under sodium acetate and methanol stress, respectively.