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:Synthetic water
Denitrification system:Sulfur-driven denitrification (SDN) system
Denitrifying reactor:Fluidized-bed reactor
Medium:Biofilm-coated granular activated carbon
Culture taken from:Mixotrophic biofilm
Organism (s) cultured:nan
Respiration:Anaerobic
Electron donor:Thiosulfate
Electron acceptor:Nitrate
Input NO3-N (mg/l):nan
Nitrate removal rate (mg NO3-N/l/h):nan
Denitrification rate (gNO3-N removed/m3/day):nan
Microorganisms identified:Thiobacillus denitrificans; Chryseobacterium koreense; Thermomonas fusca; Geothrix fermentans
Molecular tools:PCR-DGGE
Major findings:In order to alleviate the problems associated with SLAD (sulfur-limestone autotrophic denitrification) researchers in this study proposed the application of bed fluidization as an effective solution to overcome the drawbacks related to packed-bed reactors (PBR) operation. A novel FBR configuration featuring a carbonation unit was able to sustain 100% denitrification even at a pH as low as 4.75.
Authors:Di Capua et al., 2017
Title:High-rate thiosulfate-driven denitrification at pH lower than 5 in fluidized-bed reactor.
Pubmed link:None
Full research link:Link
Abstract:This study investigated the potential of a fluidized-bed biofilm dominated by Thiobacillus denitrificans to sustain thiosulfate-driven denitrification under increasingly acidic conditions. A fluidized-bed reactor (FBR) performing denitrification via thiosulfate (S2O3 2) oxidation of a nitrate-contaminated synthetic wastewater was first operated under decreasing feed pH values from 7.00 to 5.25. Denitrification efficiency > 99% was observed even at feed and effluent pH of 5.75 and 5.30, respectively. At lower feed pH values, the denitrification efficiency decreased rapidly due to inorganic carbon deficiency. The addition of a carbonation unit continuously feeding anaerobic grade CO2 to the FBR biofilm allowed to investigate denitrification at pH values lower than 5.0. This new configuration, i.e. FBR with a carbonation unit, was able to sustain a complete and stable denitrification even at pH as low as 4.75. Denaturing gradient gel electrophoresis (DGGE) showed the evolution of the denitrifying biofilm during the FBR operation, resulting in a robust and high-performing mixotrophic consortium of chemolithotrophic and heterotrophic bacteria dominated by T. denitrificans. Batch activity tests performed at three different stages of the FBR operation (feed pH 7.0, 6.0 and 5.25) showed that low pH cultivation enhanced the denitrification activity (mg N/g VS d) of the FBR biofilm at acidic pH values.