Ph.D.:  Environmental Geoscience-Environmental Toxicology, Michigan State University, 2002 

Research interests:

• Environmental biogeochemistry
• Coupled biogeochemical cycles in anaerobic terrestrial and aquatic environments
• Low-temperature aqueous geochemistry
• Chemical fate and transport
• Applied environmental toxicology
• Reactive multi-phase numerical modeling
• Quantifying the means by which hydrogeologic, microbiologic, and geochemical processes combine to drive spatial and temporal variability in elemental cycles is a fundamental issue in addressing environmental concerns related to human health and long-term ecological sustainability. The biogeochemical cycling (fate and transport) of numerous chemical species, including nutrients and anthropogenic contaminants, are controlled by changes in the reduction-oxidation potential or redox state of a system. Many redox reactions including the degradation of organic contaminants and nutrient cycles are mediated by the metabolic activities of microorganisms. Microbial metabolism, through a series of terminal electron accepting processes (TEAPs), impacts the form, mobility, toxicity and persistence of many chemical constituents in aqueous systems. My research focuses on understanding the controls on the spatial and temporal variability of TEAPs which is necessary to evaluate health and safety concerns such as: chemical routes of exposure (risk assessment), natural attenuation and bioremediation capabilities, and the management of redox sensitive environments such as wetlands and estuaries.

Courses:

• GEOL 410: Hydrogeology
• GEOL 310: Environmental Geochemistry
• GEOL 111: Introductory Physical Geology
• ESCI 310: Environmental Problem Solving

Projects:

• NSF-Biocomplexity in the Environment "Quantifying the Role of Mixing Interfaces in Biogeochemical Cycling in a Contaminated Aquifer-Wetland System: Linking Hydrogeological, Microbiological, and Geochemical Processes.
• NSF-Hydrological Sciences-Flow-Induced Redox Geochemistry within Fractured/Macroporous and Layered Vadose Zone

Peer-Reviewed Publications: (*indicated graduate student author)

• Phanikumar M.S., and McGuire, J.T., in press, A general numerical model for analysis of single-well push-pull test data.  Accepted Computers & Geosciences September 2007.
• *Baez-Cazull, S.E., McGuire, J.T., Cozzarelli I.M., and Voytek, M.A., in press, Determination of dominant biogeochemical processes in a contaminated aquifer-wetland system using multivariate statistical analyses. Accepted Journal of Environmental Quality August 2007. (PDF)
• *Kneeshaw, T.A. McGuire, J.T., Cazull, S.E.B., Smith, E.W., Cozzarelli, I.M., in press, Evaluation of sulfate reduction at experimentally induced mixing interfaces using small-scale push-pull tests in an aquifer-wetland system. Applied Geochemistry, special issue on Biogeochemical Gradients, accepted November 30, 2006. (PDF)
• *Baez-Cazull, S.E.B. McGuire, J.T., Cozzarelli, I.M., Raymond. A. and Welsh, L., in press, Centimeter-scale characterization of biogeochemical gradients at a wetland-aquifer interface using capillary electrophoresis. Applied Geochemistry, special issue on Biogeochemical Gradients, accepted December 5, 2006.(PDF)
• Velbel, M.A., McGuire, J.T., and Madden, A.J., 2007, Scanning electron microscopy of garnet from southern Michigan soils:  Etching rates and inheritance of pre-glacial and pre-pedogenic grain-surface textures.  Chapter 15, Developments in Sedimentology, Volume 58; Heavy Minerals in Use, edited by Maria A. Mange and David T. Wright. (PDF)
• McGuire, J.T., Long, D.T., Hyndman, D.W., 2004, Analysis of recharge induced geochemical change in a contaminated aquifer.  Ground Water, 43(4), 518-530.(PDF)
• Phanikumar, M. S., and McGuire, J.T. 2004, A 3D partial-equilibrium model to simulate coupled hydrogeological, microbiological, and geochemical processes in subsurface systems. Geophysical Research Letters 31 (LII503):1-4. (PDF)
• Haack, S.K., Fogarty, L.R., West, T.G., Alm, E.W., McGuire, J.T., Long, D.T., Hyndman, D.W., Forney, L.J., 2004, Spatial and temporal changes in microbial community structure over spatial and temporal chemical gradients in a contaminated aquifer, Environmental Microbiology, 6(5), 438-448. (PDF)
• McGuire, J. T., Long, D.T., Klug, M.J., Haack, S.K., and Hyndman, D.W., 2002, Evaluating the behavior of oxygen, nitrate, and sulfate during recharge and quantifying reduction rates in a contaminated aquifer, Environmental Science and Technology, 36, 2693-2700. (PDF)
• McGuire, J. T., Smith, E. W., Long, D. T., Hyndman, D. W., Haack, S. K., Klug, M. J., and Velbel, M. A., 2000,  Temporal variations in parameters reflecting terminal-electron-accepting processes in an aquifer contaminated with waste fuel and chlorinated solvents, in K. Konhauser and G. Southam (eds.), Geomicrobiology - Technical Session 06, 110th Geological Society of America Annual Meeting.  Chemical Geology, 169:471-485. (Invited paper) (PDF)
• McGuire, J.T., Smith, E.W., Long, D.T., Hyndman, D.W., Haack, S.K., Kolak, J.J., Klug, M.J., Velbel, M.A., and Forney, L.J., 1999,  Temporal variations in biogeochemical processes that influence ground water redox zonation.  In Morganwalp, D.W., and Buxton, H.T., eds., U.S. Geological Survey Toxic Substances Hydrology Program--Proceedings of the Technical Meeting, Charleston, South Carolina, March 8-12, 1999, USGS Water-Resources Investigations Report 99-4018C, 641-652. (PDF)