Microbial Communities Associated with Zones of Elevated Magnetic Susceptibility in Hydrocarbon-Contaminated Sediments

Beaver, C. L.; Williams, Anja E.; Atekwana, Estella A.; Mewafy, Farag M.; Aal, Gamal Z. Abdel; Slater, Lee; Rossbach, Silvia

doi:10.1080/01490451.2015.1049676

Cited by 23 publications

(22 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[] documented enhanced magnetite content in hydrocarbon‐contaminated samples compared to noncontaminated soils and sediments, suggesting microbial Fe(III) reduction as the possible cause for the enrichment in magnetite within the zone of contamination. At our study site, recent microbial studies have identified the presence of Albidiferax (an Fe(III) reducing bacteria), Geobacter and Desulfosporosinus sp (that is also known to reduce iron) in addition to methanogens and syntrophic bacteria in the zone of enhanced magnetic susceptibility [ Beaver et al ., ]. Thus, the microbial results support the idea of a microbial‐mediated origin of magnetite across the contaminated plume.…”

Section: Discussionsupporting

confidence: 75%

High-resolution magnetic susceptibility measurements for investigating magnetic mineral formation during microbial mediated iron reduction

Atekwana

Mewafy

Aal

et al. 2014

J. Geophys. Res. Biogeosci.

Self Cite

View full text Add to dashboard Cite

Disimilatory iron-reducing bacteria play an important role in the reduction of Fe(hydr)oxides and the production of secondary solid-iron mineral phases that can have magnetic properties. Magnetic susceptibility can therefore play an important role in identifying zones where microbial-mediated iron reduction is occurring. We investigated the magnetic susceptibility variations in a hydrocarbon-contaminated aquifer where methanogenesis and iron reduction are the main biogeochemical processes. Our objectives are to (1) determine the variability of magnetic susceptibility, (2) determine the hydrobiogeochemical controls on the magnetic susceptibility variability, and (3) evaluate the use of magnetic susceptibility as a viable technique for identifying zones where the coupling of iron and organic carbon cycling is occurring. Magnetic susceptibility data were acquired down 11 boreholes within contaminated and uncontaminated locations. We show that magnetic susceptibility values for boreholes within the free phase plume are higher than values for boreholes within the dissolved phase plume and background. Magnetic susceptibility values are highest within the zone of water table fluctuation with peaks predominantly occurring at the highest water table marks and are also coincident with high concentrations of dissolved Fe(II) and organic carbon content, suggesting that the zone of water table fluctuation is most biologically active. High magnetic susceptibility values within the vadose zone above the free phase plume are coincident with a zone of methane depletion suggesting aerobic or anaerobic oxidation of methane coupled to iron reduction. Our results suggest that magnetic susceptibility can be used as a viable tool in iron and carbon cycling studies.

show abstract

Section: Discussionsupporting

confidence: 75%

High-resolution magnetic susceptibility measurements for investigating magnetic mineral formation during microbial mediated iron reduction

Atekwana

Mewafy

Aal

et al. 2014

J. Geophys. Res. Biogeosci.

Self Cite

View full text Add to dashboard Cite

show abstract

“…2 gas data are consistent with known reactions and microbial data from the oil body and overlying vadose zone. The microbial population in the sediments containing residual oil is dominated by fermenters and methanogens (Beaver et al, 2015;Bekins et al, 1999Bekins et al, , 2005Warren et al, 2014). Biodegradation of n-alkanes occurs under methanogenic conditions at the site (Anderson and Lovley, 1999;Hostettler et al, 2008) and Ng et al (2015) demonstrated that the n-alkane fraction contributes the majority of methane produced by degradation of the oil.…”

Section: Site Descriptionmentioning

confidence: 99%

Relating subsurface temperature changes to microbial activity at a crude oil-contaminated site

Warren

Bekins

2015

Journal of Contaminant Hydrology

View full text Add to dashboard Cite

“…The DPFCB system has advantages over conventional coring systems for investigations where continuous sediment profiles or discrete samples of the unsaturated and saturated zones are needed. For example, many studies that evaluated biogeochemistry at the Bemidji site (e.g., Beaver et al, 2016) required core samples from land surface through the upper 2 m of the saturated zone to a total depth of as much as 11 m. To collect a continuous 11‐m core profile at the Bemidji site, core samplers typically have been pushed in 0.6‐m (2‐ft) increments through the unsaturated zone. Saturated zone cores are then collected with either a Murphy and Herkelrath (1996) freeze shoe or the DPFCB.…”

Section: Resultsmentioning

confidence: 99%

A Direct‐Push Freezing Core Barrel for Sampling Unconsolidated Subsurface Sediments and Adjacent Pore Fluids

Trost

Christy

Bekins

2018

Vadose Zone Journal

View full text Add to dashboard Cite

Contaminants passing through the unsaturated zone can undergo changes in narrow reaction zones upon reaching saturated sediments. Understanding these reactions requires sampling of sediment together with adjacent water and microbes in a manner that preserves in situ redox conditions. Use of a baskettype core catcher for saturated, noncohesive sediments results in redistribution or loss of fluids during sample retrieval. Previously developed sample-freezing drive shoes for hollow-stem auger drilling rigs lessened fluid redistribution and retained all material that entered the core barrel in noncohesive sediment cores by freezing the base of the core with liquid CO 2 . This technology has not previously been compatible with direct-push rigs that are commonly used for contaminated site assessments. Here, we describe a freezing core barrel designed for directpush rigs that is compatible with commercially available tool strings. The device can be used interchangeably with unsaturated-zone direct-push tool strings, enabling core collection for studies of contaminant transport and transformation spanning unsaturated to saturated profiles. In all 10 attempts during testing near Bemidji, MN, the device froze a 10-to 15-cm (4-6-in) plug that retained fluids and sediments in a 1.2-m (4-ft)-long, 5.0-cm (2.0-in)-diameter polyvinyl chloride (PVC) sleeve. Cores were collected from variably saturated sediments spanning the capillary fringe through the upper 2 m of the saturated zone in sandy glacial outwash sediments. The median recovery was 81% of the drive length, similar to a sample-freezing drive shoe developed for a wire-line piston core sampler operated with a hollow-stem auger drill rig.Abbreviations: DPFCB, direct-push freezing core barrel; PVC, polyvinyl chloride.Citation: Trost, J.J., T.M. Christy, and B.A. Bekins. 2018. A direct-push freezing core barrel for sampling unconsolidated subsurface sediments and adjacent pore fluids. Vadose Zone

show abstract

Microbial Communities Associated with Zones of Elevated Magnetic Susceptibility in Hydrocarbon-Contaminated Sediments

Cited by 23 publications

References 56 publications

High-resolution magnetic susceptibility measurements for investigating magnetic mineral formation during microbial mediated iron reduction

High-resolution magnetic susceptibility measurements for investigating magnetic mineral formation during microbial mediated iron reduction

Relating subsurface temperature changes to microbial activity at a crude oil-contaminated site

A Direct‐Push Freezing Core Barrel for Sampling Unconsolidated Subsurface Sediments and Adjacent Pore Fluids

Contact Info

Product

Resources

About