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:Wastewater
Denitrification system:Autotrophic denitrification
Denitrifying reactor:Upflow anoxic hybrid growth reactor (UAHGR);
Medium:Synthetic activated ceramic
Culture taken from:Thiobacillus denitrificans; Anaerobic digester sludge
Organism (s) cultured:nan
Respiration:Anaerobic
Electron donor:Sulfidic caustic
Electron acceptor:Nitrate
Input NO3-N (mg/l):0.4
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:Sulfidic caustic was used an alternative to sulfur-limestone to supply electron donor and limestone during autotrophic denitrification. In both reactor systems high nitrate removal rates were recorded. The UAHGR was a more stable denitrification reactor system for nitrate and sulfate concentrations.
Authors:Byun et al., 2008
Title:A new method of autotrophic denitrification with spent sulfidic caustic as substrate and alkalinity source
Pubmed link:None
Full research link:Link
Abstract:A new method based on sulfide utilizing autotrophic denitrification was adopted to remove nitrate from wastewater and to reuse spent sulfidic caustic containing high sulfide and alkalinity levels. The experiments were performed using a bench-scale upflow anoxic hybrid growth reactor (UAHGR) and an upflow anoxic suspended growth reactor (UASGR) to characterize the stoichiometric relationship between sulfur and nitrate in the process as well as the performance of the reactors. The level of nitrate removal from the UAHGR and UASGR were maintained at over 90% at a nitrate loading rate ranging from 0.15?0.40 kgNO3 ?/m3·d and no significant nitrite accumulation was observed in either reactor. Although the influent pH values were higher than the optimum range of autotrophic denitrification at 8.7?10.1, the effluent pH was stable at 7.2?7.9 due to the production of hydrogen ions during operation. The stoichiometric ratio of sulfate production to nitrate removal was 1.5?2.1 mgSO4 2?/mgNO3 ? in both reactors. A comparison of the reactor performance revealed that the chemical parameters of the UAHGR operation corresponded to a plug flow like type reactor while the chemical parameters of the UASGR operation corresponded to a completely stirred tank reactor like type reactor. UAHGR did not require sludge recycling due to the packed media while UASGR required 300?700% sludge recycling. Therefore, spent sulfidic caustic could be used in the sulfur utilizing autotrophic denitrification processes as substrate and alkalinity sources.