Master of Science (MS)
First Committee Member
David Kreamer, Chair
Second Committee Member
Third Committee Member
Graduate Faculty Representative
Number of Pages
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.
Clay minerals – Permeability; Hysteresis; Montmorillonite; Organic compounds – Biodegradation; Sediments (Geology) – Permeability; Smectite; Soil absorption and adsorption; Soil chemistry; Soil pollution
Geology | Sedimentology | Soil Science
Fairley, Jerry Paul, "Desorption hysteresis in five ion exchanged montmorillonites" (1992). UNLV Theses, Dissertations, Professional Papers, and Capstones. 1425.