Premium
Magnetic susceptibility as a proxy for investigating microbially mediated iron reduction
Author(s) -
Mewafy Farag M.,
Atekwana Estella A.,
Werkema D. Dale,
Slater Lee D.,
Ntarlagiannis Dimitrios,
Revil André,
Skold Magnus,
Delin Geoffrey N.
Publication year - 2011
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2011gl049271
Subject(s) - environmental chemistry , bioremediation , methane , anaerobic oxidation of methane , hydrocarbon , contamination , vadose zone , environmental science , iron bacteria , anaerobic bacteria , iron oxide , chemistry , bacteria , geology , soil science , ecology , soil water , biology , paleontology , organic chemistry
We investigated magnetic susceptibility (MS) variations in hydrocarbon contaminated sediments. Our objective was to determine if MS can be used as an intrinsic bioremediation indicator due to the activity of iron‐reducing bacteria. A contaminated and an uncontaminated core were retrieved from a site contaminated with crude oil near Bemidji, Minnesota and subsampled for MS measurements. The contaminated core revealed enriched MS zones within the hydrocarbon smear zone, which is related to iron‐reduction coupled to oxidation of hydrocarbon compounds and the vadose zone, which is coincident with a zone of methane depletion suggesting aerobic or anaerobic oxidation of methane is coupled to iron‐reduction. The latter has significant implications for methane cycling. We conclude that MS can serve as a proxy for intrinsic bioremediation due to the activity of iron‐reducing bacteria iron‐reducing bacteria and for the application of geophysics to iron cycling studies.