[Triumf-seminars] TRIUMF Seminar today at 14:00

postmaster at admin.triumf.ca postmaster at admin.triumf.ca
Mon Jan 12 05:00:00 PST 2009


Date/Time: Mon 2009-01-12 at 14:00

Location:  Auditorium          

Speaker:   Kristina Keating (Stanford University)

Title:     Using Nuclear Magnetic Resonance to Monitor Iron Mineralization Processes

Abstract: Proton nuclear magnetic resonance (NMR) measurements can be used to probe the physical and chemical environment of water within the pore spaces of geological materials. In geophysics, NMR relaxation measurements are used to measure water content and estimate permeability in the top 100 m of Earth's surface. The goal of my research is to determine if NMR can also be used to monitor iron mineralization processes associated with contaminant remediation.  

My research will be presented in two parts. First, I show that NMR response of water in a geologic material is sensitive to the presence and mineral form of iron. To do this, I made laboratory NMR measurements on Fe(III)-bearing minerals (ferrihydrite, lepidocrocite, goethite, and hematite) and a mixed valence iron-bearing mineral (magnetite), and showed that mineral form - and not just concentration - affects the NMR response. Second, I show that NMR relaxation rates can be used to monitor temporal changes in iron minerals by measuring a common geochemical reaction associated with contaminant remediation - the reaction of ferrihydrite with aqueous Fe(II).  These results show that NMR relaxation rates are sensitive to common geochemical reactions and provide evidence that NMR could be used as a non-invasive method for monitoring contaminant remediation in the field.

Stimulants available 15 minutes before the talk.

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