Proton Nuclear Magnetic Resonance (NMR) Relaxometry in Soil Science Applications

Abstract

Proton NMR relaxometry is a very powerful tool for investigating porous media and their interaction with water or other liquids and the mobility and interaction of organic molecules in solution. It is commonly used in material science or earth science. However, it is only scarcely applied in soil science although it shows great potential for helping to understand water uptake into the soil matrix and processes occurring at the solid-liquid interface at soil particle surfaces. This review introduces proton NMR relaxometry in the context of soil science and discusses the most important applications of the method in this field. Relevant results from different applications of NMR relaxometry in soils are described and research gaps identified. Some original data is presented concerning biofilm formation in soils, which was investigated using proton NMR relaxometry. NMR relaxometry is a sensitive, informative and promising method to study pore size distribution in soils as well as many kinds of soil physicochemical processes, among which are wetting, swelling or changes in macromolecular status. It is further a very helpful method to study interactions between molecules in soil organic matter and can serve to study the state of binding of water or organic chemicals to soil organic matter. Relaxation times determined by NMR relaxometry are sensitive to various factors that play a role in soil-water interaction which is both an advantage and shortcoming of the method: NMR relaxometry can be applied to numerous investigations in soil science, but at the same time interpretation of the results may be very difficult in such complex and heterogeneous systems like soils.

Structural Dynamic Study of Roof Waterproofing Materials

“…It should be noted that the study of NMR spectra is based on the resonating nuclei systems that are extremely sensitive to the magnetic environment where the local magnetic fields near the resonating nuclei are dependent on the intra-and intermolecular effects. This determines the value of NMR spectroscopy to investigate the structure and behavior of many-electron (molecular) systems in different fields of science (Washburn and Birdwell, 2013;Nascimento, et al, 2004;Bayer, et al, 2010;Berman, et al, 2013;Charlier, et al, 2013;Kemalov, et al, 2012;Kruk et al, 2012, Twieg, 2013, Frantsuzov, 2010.…”

Combined proton NMR wideline and NMR relaxometry to study SOM-water interactions of cation-treated soils

“…1 H NMR relaxometry and 1 H NMR wideline analysis, which have been introduced into soil science only recently (Jaeger et al, 2011;Jaeger et al, 2010;, are among the most promising techniques regarding these questions. A review on the potential and current applications of NMR relaxometry in soil science applications can be found in Bayer et al (2010). NMR relaxometry is a sensitive method to study many kinds of physicochemical soil interactions, among which are wetting, swelling or changes in macromolecular status .…”

Magnetic resonance analysis of carbon content in paper mill sludge–soil mixtures used in remediation practices

“…Application of TD-NMR techniques in petrophysical and geophysical sciences are today well established; however, it is not yet frequently used in soil science, although it exhibits great potential. Heterogeneity of soils and the particular structure of OM contained in soils (not yet fully understood) do not allow one to easily transfer one-to-one TD-NMR geophysical or petrophysical studies to soil science (Bayer et al 2010). Moreover, in natural soils, the paramagnetic ions concentration is high enough to significantly change the surface relaxivity q (the NMR relaxation strength due to the interactions of 1 H nuclei with pore surface), by increasing q of some order of magnitude if compared with systems with no paramagnetic ions.…”

“…Thus, particular care has been used to prepare and investigate the samples. Moreover, the T 2 analysis usually adopted in soil science, normally performed with the standard Carr-Purcell-Meiboom-Gill sequence (Bayer et al 2010), cannot easily be used in quantitative analyses of PMSSM samples, because of their strong paramagnetic ions content.…”