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:Saline wastewater
Denitrification system:Sulfur-driven denitrification (SDN) system
Denitrifying reactor:PBR (Packed bed reactor)
Medium:Sulphur granules
Culture taken from:Thiobacillus denitrificans
Organism (s) cultured:nan
Respiration:Anaerobic
Electron donor:Elemental sulphur
Electron acceptor:Nitrate
Input NO3-N (mg/l):nan
Nitrate removal rate (mg NO3-N/l/h):17.5
Denitrification rate (gNO3-N removed/m3/day):nan
Microorganisms identified:nan
Molecular tools:nan
Major findings:Autotrophic bacteria, Thiobacillus denitrificans was immobilized on surfaces of sulphur granules in the columns of a packed bed reactor and used to remove nitrate from wastewater.
Authors:Gu et al., 2004
Title:Removal of High NO3- Concentrations in Saline Water Through Autotrophic Denitrification by the Bacterium Thiobacillus Denitrificans Strain MP
Pubmed link:Link
Full research link:Link
Abstract:Autotrophic denitrification by Thiobacillus denitrificans MP isolated from mangrove was investigated in both a sulphur-limestone column reactor and a fermenter. More than 97.5% of the nitrate (NO3-) in the 250 mg NO3--N/L strong influent was removed after 14.3 hours in the column reactor. Influent NO3- was completely depleted in the lower part of the column as the hydraulic retention time increased and a slight pH drop was also observed along the reactor column due to the exhaustion of the buffering ability of the limestone. Trace amounts of oxygen present in the lower part of the reactor column resulted in the accumulation of nitrite and subsequent inhibition of further denitrification. The species composition of the bacterial community in the higher parts of the reactor column was morphologically more diverse than in the lower part. Denitrification by T. denitrificans MP reached an optimal level when the dissolved oxygen was maintained between 1.5-2% of saturation level in the automated fermenter. The stoichiometric ratios of ?SO42- produced/?NO3--N removed were 6.81 and 9.32 in the reactor column and fermenter, respectively. This study suggests that efficient removal of high NO3Ð concentrations in water or wastewater can be achieved using autotrophic bacteria immobilized on surfaces of sulphur granules in the column system.