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:Tap water
Denitrification system:Sulfur-based autotrophic denitrification and heterotrophic denitrification
Denitrifying reactor:Column packed-bed reactor
Medium:nan
Culture taken from:Denitriying activated sludge
Organism (s) cultured:nan
Respiration:Anaerobic
Electron donor:Elemental sulfur
Electron acceptor:Nitrate
Input NO3-N (mg/l):110-450
Nitrate removal rate (mg NO3-N/l/h):13.4-42.2
Denitrification rate (gNO3-N removed/m3/day):0.45
Microorganisms identified:nan
Molecular tools:nan
Major findings:Sodium bicarbonate was used as the alkalinity source it resulted in the enhanced the performance of the sulfur based autotrophic denitrification compared to when limestone was used. Stimulating mixtrophic denitrification process with methanol supplemented the process three folds.
Authors:Sahinkaya and Dursun., 2012
Title:Sulfur-oxidizing autotrophic and mixotrophic denitrification processes for drinking water treatment: Elimination of excess sulfate production and alkalinity requirement
Pubmed link:Link
Full research link:Link
Abstract:This study evaluated the elimination of alkalinity need and excess sulfate generation of sulfur-based autotrophic denitrification process by stimulating simultaneous autotrophic and heterotrophic (mixotrophic) denitrification process in a column bioreactor by methanol supplementation. Also, denitrification performances of sulfur-based autotrophic and mixotrophic processes were compared. In autotrophic process, acidity produced by denitrifying sulfur-oxidizing bacteria was neutralized by the external NaHCO(3) supplementation. After stimulating mixotrophic denitrification process, the alkalinity need of the autotrophic process was satisfied by the alkalinity produced by heterotrophic denitrifiers. Decreasing and lastly eliminating the external alkalinity supplementation did not adversely affect the process performance. Complete denitrification of 75 mg L(-1) NO(3)-N under mixotrophic conditions at 4 h hydraulic retention time was achieved without external alkalinity supplementation and with effluent sulfate concentration lower than the drinking water guideline value of 250 mg L(-1). The denitrification rate of mixotrophic process (0.45 g NO(3)-N L(-1) d(-1)) was higher than that of autotrophic one (0.3 g NO(3)-N L(-1) d(-1)). Batch studies showed that the sulfur-based autotrophic nitrate reduction rate increased with increasing initial nitrate concentration and transient accumulation of nitrite was observed.