Influent:Synthetic water
Denitrification system:Sulfur limestone autotrophic denitrification (SLAD)
Denitrifying reactor:Packed-bed
Medium:Elemental sulphur granules
Culture taken from:Municipal digested sludge
Organism (s) cultured:nan
Respiration:Anaerobic
Electron donor:Sulphur-limestone
Electron acceptor:Nitrate
Input NO3-N (mg/l):1.19
Nitrate removal rate (mg NO3-N/l/h):0.95
Denitrification rate (gNO3-N removed/m3/day):nan
Microorganisms identified:Citromicrobium Bathyomarinum
Molecular tools:PCR-RFLP and PCR-DGGE
Major findings:In this study autotrophic denitrification process using sulfur-limestone as the electron donor was viable in removing the nitrate and nitrite, especially from the low concentration water such as surface water and underground water.
Authors:Zhou et al., 2011
Title:Autotrophic denitrification for nitrate and nitrite removal using sulphur-limestone.
Pubmed link:None
Full research link:Link
Abstract:Sulfur-limestone was used in the autotrophic denitrification process to remove the nitrate and nitrite in a lab scale upflow biofilter. Synthetic water with four levels of nitrate and nitrite concentrations of 10, 40, 70 and 100 mg N/L was tested. When treating the low concentration of nitrate- or nitrite-contaminated water (10, 40 mg N/L), a high removal rate of about 90% was achieved at the hydraulic retention time (HRT) of 3 hr and temperature of 20–25°C. At the same HRT, 50% of the nitrate or nitrite could be removed even at the low temperature of 5–10°C. For the higher concentration nitrate and nitrite (70, 100 mg N/L), longer HRT was required. The batch test indicated that influent concentration, HRT and temperature are important factors affecting the denitrification efficiency. Molecular analysis implied that nitrate and nitrite were denitrified into nitrogen by the same microorganisms. The sequential two-stepreactions from nitrate to nitrite and from nitrite to the next-step product might have taken place in the same cell during the autotrophic denitrification process.