Influent:Synthetic wastewater
Anammox system:nan
Anammox reactor:Sequencing batch reactor (SBR)
Medium:Granular sludge
Culture taken from:Municipal wastewater treatment plants (WWTP)
Microorganism cultured:Candidatus Kuenenia stuttgartiensis, Brocadia fulgida, Nitrosomonas
Respiration:Anaerobic
Electron donor:Ammonium sulfate ((NH4)2SO4)
Electron acceptor:Sodium Nitrite (NaNO2)
PH:6.88
Maximum sludge concentration:7
HRT:1 d
NH4–N Influent conc(mg/L):410–810
NO2–N Influent conc(mg/L):nan
SO4–S Influent conc(mg/L):nan
NH4–N Removal efficiency (%):nan
NO2–N Removal efficiency (%):nan
SO4-S Removal efficiency (%):nan
NLR kg-N/m3/d:0.2
NRR kg-N/m3/d:0.6
Major findings:More difficult for oxygen to penetrate thick layers and it protected anammox from non-suitable liquid media conditions (benefit to anammox)
Authors:Morales et al., 2015
Title:Influence of dissolved oxygen concentration on the start-up of the anammox-based process: ELAN®
Pubmed link:Link
Full research link:Link
Abstract:The anammox-based process ELAN® was started-up in two different sequencing batch reactor (SBR) pilot plant reactors treating municipal anaerobic digester supernatant. The main difference in the operation of both reactors was the dissolved oxygen (DO) concentration in the bulk liquid. SBR-1 was started at a DO value of 0.4 mg O2/L whereas SBR-2 was started at DO values of 3.0 mg O2/L. Despite both reactors working at a nitrogen removal rate of around 0.6 g N/(L d), in SBR-1, granules represented only a small fraction of the total biomass and reached a diameter of 1.1 mm after 7 months of operation, while in SBR-2 the biomass was mainly composed of granules with an average diameter of 3.2 mm after the same operational period. Oxygen microelectrode profiling revealed that granules from SBR-2 where only fully penetrated by oxygen with DO concentrations of 8 mg O2/L while granules from SBR-1 were already oxygen penetrated at DO concentrations of 1 mg O2/L. In this way granules from SBR-2 performed better due to the thick layer of ammonia oxidizing bacteria, which accounted for up to 20% of all the microbial populations, which protected the anammox bacteria from non-suitable liquid media conditions.