Oxygen Diffusion Through Soil Covers at Differnt Degrees of Saturation
Principal Investigator: Phil Patton
pknudsen@mtech.edu
The main objective of this project was to determine oxygen flux
through one component of a typical barrier cap at a variety of moisture
conditions. Oxygen flux through topsoil was determined through a
combination of percent oxygen measurements and the use of theoretical
equations. The goal was to develop a best fit curve to describe
oxygen diffusion under differing moisture conditions. Five diffusion
cells were constructed of eight-inch PVC, the cells were then filled
with soil and compacted to 90%, which mimics field conditions. The
upper and lower reservoirs of each cell were connected to oxygen
meters to record oxygen concentrations. The meter connected to the
upper reservoirs also had the capability to measure carbon dioxide
concentrations; thus, those measurements were also recorded. Oxygen
diffusion and carbon dioxide were measured at moisture contents
of 6%, 10%, 13%, 16%, and 18%. Oxygen diffusion coefficients, along
with oxygen flux were calculated for the five moisture contents
studied. As was expected, the calculations of the effective diffusion
coefficients and oxygen flux illustrated that moisture content plays
a very important role in controlling oxygen diffusion.
MWTP Activity IV, Project 34
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