Denitrification Biokinetics: Towards Optimization for Industrial Applications.

Denitrification is a microbial process that converts nitrate (NO ) to N and can play an important role in industrial applications such as souring control and microbially enhanced oil recovery (MEOR). The effectiveness of using NO in souring control depends on the partial reduction of NO to nitrite (NO ) and/or NO while in MEOR complete reduction of NO to N is desired. has been reported as a dominant taxon in such applications, but the impact of NO and NO concentrations, and pH on the kinetics of denitrification by this bacterium is not known.

Microbially Enhanced Oil Recovery by Alkylbenzene-Oxidizing Nitrate-Reducing Bacteria.

Microbially enhanced oil recovery (MEOR) of heavy oil and bitumen is challenging because light hydrocarbons, which can feed resident microbial communities are present in low concentrations, if at all. We have recently shown that increasing the toluene concentration of heavy oil by aqueous injection followed by injection of nitrate boosts the activity of toluene-oxidizing nitrate-reducing bacteria in heavy oil-containing sand pack columns, giving production of residual oil in place (ROIP). In the current work we found that ethylbenzene is as effective as toluene.

The Effectiveness of Nitrate-Mediated Control of the Oil Field Sulfur Cycle Depends on the Toluene Content of the Oil.

The injection of nitrate is one of the most commonly used technologies to impact the sulfur cycle in subsurface oil fields. Nitrate injection enhances the activity of nitrate-reducing bacteria, which produce nitrite inhibiting sulfate-reducing bacteria (SRB). Subsequent reduction of nitrate to di-nitrogen (N) alleviates the inhibition of SRB by nitrite.

Nitrate-Mediated Microbially Enhanced Oil Recovery (N-MEOR) from model upflow bioreactors.

Microbially Enhanced Oil Recovery (MEOR) can enhance oil production with less energy input and less costs than other technologies. The present study used different aqueous electron donors (acetate, glucose, molasses) and an aqueous electron acceptor (nitrate) to stimulate growth of heterotrophic nitrate reducing bacteria (hNRB) to improve production of oil. Initial flooding of columns containing heavy oil (viscosity of 3400cP at 20°C) with CSBK (Coleville synthetic brine medium) produced 0.

Microbially Enhanced Oil Recovery by Sequential Injection of Light Hydrocarbon and Nitrate in Low- And High-Pressure Bioreactors.

Microbially enhanced oil recovery (MEOR) often involves injection of aqueous molasses and nitrate to stimulate resident or introduced bacteria. Use of light oil components like toluene, as electron donor for nitrate-reducing bacteria (NRB), offers advantages but at 1-2 mM toluene is limiting in many heavy oils. Because addition of toluene to the oil increased reduction of nitrate by NRB, we propose an MEOR technology, in which water amended with light hydrocarbon below the solubility limit (5.