Achieving nitritation and anammox enrichment in a single moving-bed biofilm reactor treating reject water

• Published in: Environmental technology 2012-03, Vol.33 (6), p.703-710
• Main Authors: Zekker, I, Rikmann, E, Tenno, T, Saluste, A, Tomingas, M, Menert, A, Loorits, L, Lemmiksoo, Vallo
• Format: Article
• Language: English
• Subjects: Aeration; Ammonia; Ammonia-oxidizing bacteria; Ammonium; anaerobic ammonium oxidation; Anaerobic microorganisms; anammox; Applied sciences; Bacteria; bacterial communities; bicarbonate; biofilm; Biofilms; Biofilms - growth & development; Bioreactors - microbiology; Communities; deammonification; Dissolved oxygen; Elevated; environmental technology; Equipment Design; Equipment Failure Analysis; Exact sciences and technology; Hydraulic retention time; Industrial Waste - prevention & control; Microorganisms; moving-bed biofilm reactor; nitrifying bacteria; nitritation; Nitrites - metabolism; Nitrobacter; Nitrobacter - metabolism; Nitrogen removal; nitrogen-fixing bacteria; Nitrospira; Oxidation; Oxidation-Reduction; Planctomycetales; Planctomycetota; Pollution; Process control; Quaternary Ammonium Compounds - metabolism; Reactors; Retention time; Strategy; Water Purification - methods; Water treatment
• ISSN: 1479-487X; 0959-3330; 1479-487X
• DOI: 10.1080/09593330.2011.588962

A biofilm with high nitrifying efficiency was converted into a nitritating and thereafter a nitritating–anammox biofilm in a moving-bed biofilm reactor at 26.5 (±0.5)°C by means of a combination of intermittent aeration, low dissolved oxygen concentration, low hydraulic retention time, free ammonia and furthermore, also by elevated HCO concentration. Nitrite-oxidizing bacteria (NOB) were more effectively suppressed by an enhanced HCO concentration range of 1200–2350 mg/L as opposed to free-ammonia-based process control where NOBs recovered from inhibition; the respective total-nitrogen removal rates were 0.3 kg N/(m³·d) and 0.2 kg N/(m³·d). The biofilm modification strategies resulted in a shift in bacterial community as the NOB Nitrobacter spp. were replaced with NOB belonging to the genus Nitrospiraspp. and were closely related to Candidatus Nitrospira defluvii. A community of anaerobic ammonium-oxidizing microorganisms –uncultured Planctomycetales bacterium clone P4 (closely related to Candidatus Brocadia fulgida) – was developed.