University of Toronto Department of Geology
Microbial Geochemistry Laboratory
www.geomicrobiology.ca
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Graduate Students Jennifer Kyle |
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Postdocotral Fellows
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Research Assistants
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Alumni
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Andrew Mitchell
Background
Andrew joined the microbial geochemistry laboratory (MGL) as a Post Doctoral Fellow in June 2003, having completed his B.Sc (Hons) and Ph.D at the University of Wales, Aberystwyth. His research background in environmental biogeochemistry, specifically focussed upon pristine glacial environments during his Ph.D, using a field, laboratory and modelling based approach to (i) asses the source, mobility and fate of bio-limiting minor and trace elements in an Alpine glacierised headwater, and (ii) to test the utility of geochemical flow path models (PHREEQCi) for determining temporal variations in water routing and subglacial hydrology.
His glacial research has continued and expanded at the MGL, working at field sites in the Canadian Arctic and Antarctic, to firstly examine microbial ecology and metabolic activity within and beneath polar glaciers, utilising microscopy, molecular and microcosm techniques. Secondly, he has been investigating changes in the interaction of bio-limiting nutrients with reactive proglacial suspended sediments at natural geochemical thresholds, utilising high resolution acid-base titrations and water-rock interaction experiments.
Since arriving at the microbial geochemistry group, Andrew has expanded his research interests into biomineralization and bioremediation processes. Specifically, he has been investigating the co-precipitation of radionuclides and divalent metals (Sr, Cs, Ba) in groundwater and vadose zone calcite in response to the hydrolysis of urea by urease positive bacteria. The objectives have been to assess controls on, and mechanisms of nucleation, precipitation and contaminant co-precipitation using a combination of wet chemsitry (AA, ICP-AES) microscopy (light; SEM-EDS), mineralogical (XRD; XRF) and modelling (GALOPER) techniques.
Fieldwork locations
Swiss Alps – Four consecutive summer and winter field seasons,
Antarctic Peninsula – December – March 2002.
Canadian Arctic – June – July 2004
Snake River Plain Aquifer, Idaho.