Biological Nitrogen Removal Database
A manually curated data resource for microbial nitrogen removal
Biological Nitrogen Removal Database
A manually curated data resource for microbial nitrogen removal
Influent:Groundwater
Denitrification system:Chemoautotrophic hydrogenotrophic denitrification
Denitrifying reactor:Membrane bioreactor (MBR) with membrane hydrogen gas diffusion
Medium:Suspended culture
Culture taken from:Activated sludge
Organism (s) cultured:nan
Respiration:Anaerobic
Electron donor:Hydrogen
Electron acceptor:Nitrate
Input NO3-N (mg/l):24-192
Nitrate removal rate (mg NO3-N/l/h):nan
Denitrification rate (gNO3-N removed/m3/day):nan
Microorganisms identified:nan
Molecular tools:nan
Major findings:Varying nitrate loading rates were implemented, an increase in loading rate resulted in an increase denitrifcation rate and also pH. When incomplete denitrification occurred as a result of nitrate residue in the reactor tanks, the pH decreased.
Authors:Mo et al., 2005
Title:Incorporating membrane gas diffusion into a membrane bioreactor for hydrogenotrophic denitrification of groundwater.
Pubmed link:Link
Full research link:Link
Abstract:A hydrogenotrophic denitrification system, comprising a suspended growth membrane bioreactor (MBR) with membrane hydrogen gas diffusion, was developed to remove nitrate from groundwater. A hollow fiber gas permeable membrane module was designed for hydrogen delivery and a commercially available hollow fiber membrane module was used for solid/liquid separation. The MBR was operated at an SRT of 20 days and at room temperature. Four nitrate loading rates of 24, 48, 96 and 192 NO3(-)-N mg I(-1) d(-1) were applied to the system. As the nitrate loading was raised, pH increased due to increased denitrification and release of OH- ions. The oxidation reduction potential (ORP) remained fairly stable when full denitrification was achieved, but increased when nitrate loading rates reached 192 NO3(-)-N mg I(-1) d(-1) and residual nitrate was present in the reactor. Nitrate removal was complete (100%) in the first three nitrate loadings and 72% in the system with 192 NO3(-)-N mg I(-1) d(-1). Nitrate utilization rates of 30.6, 23.4, and 37.7 g NO3(-)-N m(-3) d(-1) were achieved in the first three loadings. Average effluent dissolved organic carbon (DOC) concentration of approximately 8 mg l(-1) was observed in all four nitrate loading regimes, possibly owing to the generation and release of soluble microbial bi-products (SMP).