Award Date

1992

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Geoscience

First Committee Member

David Kreamer, Chair

Second Committee Member

John Hess

Third Committee Member

Steven Mizell

Graduate Faculty Representative

Spencer Steinberg

Number of Pages

48

Abstract

It is generally believed that the formation of recalcitrant (slowly desorbing) fractions of volatile organic compounds (VOCs) in soils is due to diffusion of compounds to sorption sites inaccessible to bulk fluid. The exact nature of these sites, however, is not well understood. In clay minerals, researchers favor two probable areas for the storage of persistent contamination; sites between the clay lamella, or sites with clay particle aggregates.


To test the hypothesis that recalcitrant fractions are formed in interlamellar spaces, a Na/Ca Montmorillonite (Smectite) was ion exchanged with five different cations (K+, Na+, Ca+, Mg2+, Fe3+) to form mineralogically similar clays with varying interlamellar environments. These soils were inoculated with an organic compound (toluene), incubated for 24 hours, and the recalcitant fraction quantified for varying desorption times. The results did not show a clear correlation between persistent contamination and the interlamellar environment. Instead, evidence appears to support the conclusion that persistent contamination may be stored in clay particle microaggregates.

Keywords

Clay minerals – Permeability; Hysteresis; Montmorillonite; Organic compounds – Biodegradation; Sediments (Geology) – Permeability; Smectite; Soil absorption and adsorption; Soil chemistry; Soil pollution

Disciplines

Geology | Sedimentology | Soil Science

File Format

pdf

Degree Grantor

University of Nevada, Las Vegas

Language

English

Comments

Incomplete paper data.

Best copy available.

Rights

IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/

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