Date of Graduation
Statler College of Engineering and Mineral Resources
Civil and Environmental Engineering
Dr. Radhey Sharma
Dr. Omar I Abdul-Aziz
Dr. P.V. Vijay
Light Non-Aqueous Phase Liquid Migration in Ground Subsurface
Groundwater aquifers are vital source for water supplies. Such water supplies are under serious potential threats of pollution due to various contaminants. One of the categories of contaminants that pollute groundwater aquifers is non-aqueous phase liquid (NAPL). NAPLs are immiscible organic compounds. NAPLs comprise two categories based on comparison of its density with density of water. The NAPLs that have density less that density of water are known as light non-aqueous phase liquid (LNAPL) such as Diesel, Toluene, and mineral oil. NAPLs with density higher than the density of water are known as dense non-aqueous phase liquid (DNAPL) such as chlorinated solvent and crude oil. It is essential to understand migration of a NAPL to locate it and its subsequent remediation.
LNAPLs can pollute groundwater aquifers due to accidental spills or leakage from underground tanks. LNAPLs migrate into ground subsurface under the force of gravity. However, the speed of LNAPLs migration depends on its relative permeability. The depth and spread of LNAPL migration depend upon the amount of LNAPL spill and its entrapment in the porous media. Migration of LNAPL depends upon properties of porous media. Furthermore, parameters such as capillary pressure, degree of saturation, porosity, and hydraulic conductivity need to be known to understand the flow of LNAPL. Moreover, Characteristics of liquids such as density, viscosity, interfacial tension, and wettability need to be understood to estimate spread of LNAPLs. During LNAPLs flow, a portion of LNAPLs gets trapped in various forms such as singlet, doublet, or ganglia.
Several scholars investigated migration of LNAPLs in porous media. These investigations include different types of experiments such as one-dimensional (1D) tests for image analysis, two-dimensional (2D) tests, Buchner funnel, and centrifuge tests. Results from different types of experiments were collected for analysis and discussion for this research. The results indicated that there is clearly inverse relationship between matric suction and degree of saturation. Residual degree and bubbling pressure head are affected by characteristics of soil. There is inverse relationship between entry pressure and grain size of the soil. Moreover, the bubbling pressure head is affected by the interfacial tension of a fluid. Area of LNAPL spread depends upon groundwater fluctuations and the frequency of these fluctuations.
Al-Hammad, Hanadi, "Light Non-Aqueous Phase Liquid Migration in Ground Subsurface" (2021). Graduate Theses, Dissertations, and Problem Reports. 10198.