Numerical and field investigation of enhanced in situ denitrification in a shallow-zone well-to-well recirculation system

Lee, Eun Jung; Kim, Mee-Jeong; Kim, Young; Lee, Kang‐Kun

doi:10.1016/j.ecolmodel.2009.06.014

Cited by 13 publications

(9 citation statements)

References 26 publications

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“…Modeling results indicated that by the end of 283 days, sulfate reduction could account for 12% (1.6 kg) of the methane degradation, while 88% (13 kg) of methane degradation was through iron reduction. The third important feature of the methane data is that after 200 days the highest concentration of dissolved methane in water samples remained constant at 29 mg/L which is within the range of methane solubility in groundwater [ Lee et al ., ]. These data indicate that methane produced near the source after 200 days was degassing.…”

Section: Resultsmentioning

confidence: 83%

Impacts of an ethanol‐blended fuel release on groundwater and fate of produced methane: Simulation of field observations

Rasa

Bekins

Mackay

et al. 2013

Water Resources Research

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In a field experiment at Vandenberg Air Force Base (VAFB) designed to mimic the impact of a small-volume release of E10 (10% ethanol and 90% conventional gasoline), two plumes were created by injecting extracted groundwater spiked with benzene, toluene, and o-xylene, abbreviated BToX (No-Ethanol Lane) and BToX plus ethanol (With-Ethanol Lane) for 283 days. We developed a reactive transport model to understand processes controlling the fate of ethanol and BToX. The model was calibrated to the extensive field dataset and accounted for concentrations of sulfate, iron, acetate, and methane along with iron-reducing bacteria, sulfate-reducing bacteria, fermentative bacteria, and methanogenic archaea. The benzene plume was about 4.5 times longer in the With-Ethanol Lane than in the No-Ethanol Lane. Matching this different behavior in the two lanes required inhibiting benzene degradation in the presence of ethanol. Inclusion of iron reduction with negligible growth of iron-reducers was required to reproduce the observed constant degradation rate of benzene. Modeling suggested that vertical dispersion and diffusion of sulfate from an adjacent aquitard were important sources of sulfate in the aquifer. Matching of methane data required incorporating initial fermentation of ethanol to acetate, methane loss by outgassing, and methane oxidation coupled to sulfate and iron reduction. Simulation of microbial growth using dual Monod kinetics, and including inhibition by more favorable electron acceptors, generally resulted in reasonable yields for microbial growth of 0.01-0.05.

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Section: Resultsmentioning

confidence: 83%

Impacts of an ethanol‐blended fuel release on groundwater and fate of produced methane: Simulation of field observations

Rasa

Bekins

Mackay

et al. 2013

Water Resources Research

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“…It has been demonstrated that in typical aquifers injectionwithdrawal systems perform optimally when the electron donor is introduced in a series of discrete pulses, as opposed to a continuous injection (Devlin and Barker, 1996;Khan and Spalding, 2003;Lee et al, 2009;Peyton, 1996). The pulses help limit the formation of biofilms, which can lead to aquifer and screen clogging (Devlin and Barker, 1994).…”

Section: Stimulated In Situ Denitrificationmentioning

confidence: 98%

Stimulating in situ denitrification in an aerobic, highly permeable municipal drinking water aquifer

Critchley

Rudolph

Devlin

et al. 2014

Journal of Contaminant Hydrology

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“…The simulations consider that the microbes are autolithotrophic if the concentration of reactive organic carbon is very low (only one microbial population is considered for both denitrification processes). Growth (fourth term of equation (1)) and decay (third term in equations (1) and (2)) are simulated similar to the studies of Lee et al (2009) and Rodríguez-Escales et al (2016). Many approaches have been published to simulate microbial transport that account for the attachment and detachment of microbes to and from the sediment (Tufenkji, 2007).…”

Section: Microbial Growth and Transport Of Microorganismmentioning

confidence: 99%

“…Some of those models do not consider in detail microbial growth (Antoniou et al, 2013;Engelhardt et al, 2014), while others account for microbial growth and decay (Clement et al, 1997;Rodríguez-Escales et al, 2016). Some investigations are based on laboratory studies (Clement et al, 1997;Mastrocicco et al, 2011;Molins et al, 2015;Rodríguez-Escales et al, 2016), while others analyze field investigations (Engelhardt et al, 2014;Lee et al, 2009). A special case is the thermodynamic approach which was employed by André et al (2011) for their laboratory studies using thermodynamic factors similar to Monod factors and which account for changes in the thermodynamic equilibrium of the redox reaction.…”

Section: Introductionmentioning

confidence: 99%

Development of a Fully Coupled Biogeochemical Reactive Transport Model to Simulate Microbial Oxidation of Organic Carbon and Pyrite Under Nitrate‐Reducing Conditions

Knabe

Kludt

Jacques

et al. 2018

Water Resources Research

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In regions with intensive agriculture nitrate is one of the most relevant contaminants in groundwater. Denitrification reduces elevated nitrate concentrations in many aquifers, yet the denitrification potential is limited by the concentration of available electron donors. The aim of this work was to study the denitrification potential and its limitation in natural sediments. A column experiment was conducted using sediments with elevated concentrations of organic carbon (total organic carbon 3,247 mg C/kg) and pyrite (chromium reducible sulfur 150 mg/kg). Groundwater with high nitrate concentration (100 mg/L) was injected. Measurements were taken over 160 days at five different depths including N‐ and S‐isotope analysis for selected samples. A reactive transport model was developed, which couples nitrate reduction with the oxidation of organic carbon (heterotrophic denitrification) and pyrite (autolithotrophic denitrification), and considers also transport and growth of denitrifying microbes. The denitrification pathway showed a temporal sequence from initially heterotrophic to autolithotrophic. However, maximum rates were lower for heterotrophic (11 mmol N/(L*a)) than for autolithotrophic denitrification (48 mmol N/(L*a)). The modeling showed that denitrifying microbes initially preferred highly reactive organic carbon as the electron donor for denitrification but were also able to utilize pyrite. The results show that after 160 days nitrate increased again to 50 mg/L. At this time only 0.5% of the total organic carbon and 46% of the available pyrite was oxidized. This indicates that denitrification rates strongly decrease before the electron donors are depleted either by a low reactivity (total organic carbon) or a diminishing reactive surface possibly due to the presence of coatings (pyrite).

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Numerical and field investigation of enhanced in situ denitrification in a shallow-zone well-to-well recirculation system

Cited by 13 publications

References 26 publications

Impacts of an ethanol‐blended fuel release on groundwater and fate of produced methane: Simulation of field observations

Impacts of an ethanol‐blended fuel release on groundwater and fate of produced methane: Simulation of field observations

Stimulating in situ denitrification in an aerobic, highly permeable municipal drinking water aquifer

Development of a Fully Coupled Biogeochemical Reactive Transport Model to Simulate Microbial Oxidation of Organic Carbon and Pyrite Under Nitrate‐Reducing Conditions

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