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
Denitrifying reactor:Rectangular channel mesocosm
Medium:Elemental sulphur granules
Culture taken from:Activated sludge
Organism (s) cultured:nan
Respiration:Anaerobic
Electron donor:Elemental sulfur
Electron acceptor:Nitrate
Input NO3-N (mg/l):0.15
Nitrate removal rate (mg NO3-N/l/h):0.04
Denitrification rate (gNO3-N removed/m3/day):nan
Microorganisms identified:nan
Molecular tools:nan
Major findings:The results showed that amendment with elemental sulphur is an effective means to stimulate denitrification in a stream environment. They suggested that it may be more desirable to place elemental sulphur where oxygen replenishment is limited, either deeper in the sediment layer or in or around drainage tiles after they saw that high oxygen concentrations would result in formation of NO and N2O.
Authors:Read-Daily et al., 2011
Title:Stimulating denitrification in a stream mesocosm with elemental sulphur as an electron donor
Pubmed link:None
Full research link:Link
Abstract:The heavy use of fertilizers in agricultural lands can result in significant nitrate (NO3 ?) loadings to the aquatic environment. We hypothesized that biological denitrification in agricultural ditches and streams could be enhanced by adding elemental sulfur (So) to the sediment layer, where it could act as a biofilm support and electron donor. Using a bench-scale stream mesocosm with a bed of So granules, we explored NO3 ? removal fluxes as a function of the effluent NO3 ? concentrations. With effluent NO3 ? ranging from 0.5 mg N L?1 to 4.1 mg N L?1, NO3 ? removal fluxes ranged from 228 mg N m?2 d?1 to 708 mg N m?2 d?1. This is as much as 100 times higher than for agricultural drainage streams. Sulfate (SO4 2?) production was high due to aerobic sulfur oxidation. Molecular studies demonstrated that the So amendment selected for Thiobacillus species, and that no special inoculum was required for establishing a So-based autotrophic denitrifying community. Modeling studies suggested that denitrification was diffusion limited, and advective flow through the bed would greatly enhance NO3 ? removal fluxes. Our results indicate that amendment with So is an effective means to stimulate denitrification in a stream environment. To minimize SO4 2? production, it may be better to place So deeper in the sediment layer.