Influent:Synthetic wastewater
Anammox system:nan
Anammox reactor:Membrane sequencing batch reactor (MSBR)
Medium:Hollow fibre membrane module
Culture taken from:Anammox biomass
Microorganism cultured:nan
Respiration:Anaerobic
Electron donor:Ammonium sulfate ((NH4)2SO4)
Electron acceptor:Sodium Nitrite (NaNO2)
PH:7.8–8.7
Maximum sludge concentration:0.4
HRT:1 d
NH4–N Influent conc(mg/L):75.3–283.4
NO2–N Influent conc(mg/L):83.7–315.4
SO4–S Influent conc(mg/L):nan
NH4–N Removal efficiency (%):73.6
NO2–N Removal efficiency (%):nan
SO4-S Removal efficiency (%):nan
NLR kg-N/m3/d:0.7
NRR kg-N/m3/d:0.7
Major findings:Salts precipitation on the biomass surface interferes with microbial activity and caused a decrease of the nitrogen removal rate. The MSBR could be a suitable system for nitrogen removal using Anammox biomass. Either biomass wash-out or contact with air were avoided by the use of the membrane. The system maintained a good activity even during periods in which a little amount of nitrite accumulated and sporadic sludge buoyancy was detected. Nitrite accumulation was removed by stopping the feeding during an operating cycle.
Authors:Trigo et al., 2006
Title:Start-up of the Anammox process in a membrane bioreactor
Pubmed link:Link
Full research link:Link
Abstract:The start-up of an Anammox process was studied in a membrane sequencing batch reactor (MSBR) in which a submerged hollow fibre membrane module was used to retain the biomass. The reactor was seed with Anammox biomass and fed using the Van de Graaf medium. During a first operating stage, salt precipitation was observed and interfered with microbial activity and caused a decrease of the nitrogen removal rate of the reactor from 100 to only 10 mgl(-1) per day. Salt precipitation was avoided by diminishing adequately the Ca and P concentrations of the Van de Graaf medium during the last operating stage. This action increased quickly the activity of the system, and nitrogen removal rate reached up to 710 mgl(-1) per day with almost full nitrite removal. Sporadic flotation of the sludge was observed in the MSBR. The use of the membrane avoided biomass wash-out from the system. Moreover, a surprising fact was that Anammox biomass did not grow in flocs in the MSBR, but in granules. This fact showed that this kind of microorganisms have a trend to grow in aggregates. Results indicated that the use of the MSBR could be a suitable system for nitrogen removal by using the Anammox reaction.