Date on Master's Thesis/Doctoral Dissertation


Document Type

Doctoral Dissertation

Degree Name

Ph. D.


Civil and Environmental Engineering

Degree Program

Civil Engineering, PhD

Committee Chair

Zhao, Qian

Committee Co-Chair (if applicable)

Mohsen, J. P.

Committee Member

Mohsen, J. P.

Committee Member

Rockaway, Thomas

Committee Member

Fu, Xiao-An

Author's Keywords

modified bentonite; organic surfactant; sorptive soil barriers; retardation


Earthen barriers such as CCLs and GCLs have been employed in geotechnical practices to provide a low permeability hydraulic barrier since long time ago. These types of barriers exhibited satisfactory performance for many applications such as landfills. The performance of low permeability barriers is based on the swelling potential of their component, which is mostly Na-bentonite, in contact with polar fluids such as water. However, the acceptable range of conductivity cannot be achieved by traditional earthen barriers when they are permeated by non-polar fluids such as gasoline. This phenomenon occurs due to the incompatibility of earthen barrier constituent with non-polar compounds. Also, the traditional earthen barriers are not able to retard the contaminant transport due to their negligible reactivity with organic compounds. As a result, the application of low permeability barriers was limited to polar and non-contaminated flows. In this study, the performance of traditional earthen barriers as a hydraulic and chemical barrier was enhanced by introducing an organically modified amendment (HDTMA-bentonite) to traditional earthen barrier’s components.