Use of NMR relaxation times to differentiate mobile and immobile pore fractions in a wetland soil

A method is presented that makes use of nuclear magnetic resonance (NMR) me asurements to differentiate between mobile and immobile pore fractions in a n organic peat specimen. The method is based on the T-1 relaxation mechanis m and uses a paramagnetic reagent to mark the effective (mobile) pore space in the specimen under examination. A setup has been developed that allows controlled fluid flow through an NMR specimen while it is positioned in a m agnet. Results from tests using fluid-filled glass tubes illustrate the app lication of the method and verify its accuracy. Results from a test using a peat moss specimen demonstrate the use of the method during a flow experim ent in a wetland soil.