to examine hydraulics of lnapls in soil, the retention curves of diesel fuel and water were both determined by hanging column method. the soil retention parameters were obtained based on van genuchten, brooks-corey and campbell’s models. in addition, the soil hydraulic conductivity for both fluids were predicted based on mualem- brooks-corey, burdine- brooks-corey, mualem-van genuchten and camp...

A novel strategy for containment of contaminated groundwater consists of a biologically produced extracellular polysaccharide (EPS) barrier, i.e. biobarrier, within a subsurface formation. To bring this technology closer to field scale, a PVC column (12 inch [30.5 cm] diameter x 48 inches [121.9 cm] high) was constructed to examine the effects of thick biofilms in porous media under radial flow...

Laboratory column experiments were conducted to study the effects of anionic polyacrylamide (PAM) polymer and surfactant linear alkylbenzene sulfonate (LAS) on the movement of Escherichia coli and the FRNA phage MS-2. The study was designed to evaluate if PAM or PAM + LAS would enhance the mobility of human pathogens in tropical soils under unsaturated conditions. No breakthrough of phage was o...

The leaching of chemical compounds (NNO3, NNH4, Norg, PPO4 and Ptot) and trace elements (Cd, Cu, Cr, Ni, zn, and Pb) from sewage sludge and their migration through the soil profile is the subject of this study. The column experiments were carried out under atmospheric conditions corresponding to naturally occurring storm events – sewage sludge amended soil was irrigated with high rates of water...

A study was conducted to evaluate the leaching potential of unpaved road materials (URM) mixed with lime activated high carbon fly ashes and to evaluate groundwater impacts of barium, boron, copper, and zinc leaching. This objective was met by a combination of batch water leach tests, column leach tests, and computer modeling. The laboratory tests were conducted on soil alone, fly ash alone, an...

Column experiments were conducted in undisturbed and in repacked soil columns at water contents close to saturation (85-96%) to investigate the transport and retention of functionalized (14)C-labeled multi-walled carbon nanotubes (MWCNT) in two natural soils. Additionally, a field lysimeter experiment was performed to provide long-term information at a larger scale. In all experiments, no break...

The mathematical model developed in this work can be used in the context of the industrial or accidental pollution of a soil with a liquid volatile organic pollutant. A relevant question for determining a possible remediation senarii is the ability to haracterize the level of the pollution in a short time. In this study, we consider a simple mathematical model for the rate limited mass transfer...

Abstract: Absorbing boundary conditions are required to simulate seismic wave propagation in elastic media. In the first part of the paper, a number of relevant ABCs are reviewed with emphasis on practicality and ease of implementation. The second part of the paper describes the derivation of a new user element for seismic analysis in ABAQUS/Standard. The element is a combination of two ideas: ...