Organic Pollutants in Soils, as Studied by Nuclear Magnetic Resonance
Abstract
This three-year project focussed on the development and application of state-of-the art NMR (nuclear magnetic resonance) techniques to elucidate the fundamental behaviors of certain organic pollutants (e.g., benzene, CCl, trichloroethylene, ethylene glycol) when adsorbed in typical soils, as represented in most of this study by the following major soil components: humics (humic acid, fulvic acid, humin), clays (montmorillonite, kaolinite) and silica. The first stage was the isolation/ separation and detailed C-13 NMR characterization of the humic materials from a soil of southwestern Colorado; this work is resulting in the most detailed chemical-structural elucidation ever carried out on such a three-component humic suite. C-13 NMR studies revealed a spectacular case of co-contamination in reactions between CCl4 and benzene adsorbed in montmorillonite clays, yielding such Friedel-Crafts products as benzophenone, benzoic acid and (C6H5)3C(+) (the last being analogous to the product in a "ship-in-a-bottle" reaction between the two initial components in HY zeolite). C-13 NMR also elucidated the photo-assisted decomposition of trichloroethylene absorbed on soil components (forming Cl2CHCO2H, Cl3CCO2H, Cl3CCHCl2 etc.), a much slower analog of the well-known conversions employing TiO2(s) as the adsorbent. H-2 NMR lineshape studies elucidated the detailed local motions of benzene, trichloroethylene and ethylene glycol adsorbed on major soil components.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 15, 1998
- Accession Number
- ADA346518
Entities
People
- Gary E. Maciel
- Willard L. Lindsay
Organizations
- Colorado State University