The aim is to simulate the test depicted in Figure 4, wherein a vertical upward flow is experienced by the soil due to an imposed
hydraulic gradient. Small sized finite
where Z is the groundwater discharge, i is the natural
hydraulic gradient and T is the aquifer transmissivity, multiplication of the depth of the aquifer with hydraulic conductivity K, which is a measure of the rate at which water moves through a unit width of the aquifer under a unit
hydraulic gradient.
Using argon or nitrogen leads to degassing in the experimental core that is subjected to a substantial
hydraulic gradient.
The
hydraulic gradient, volumetric flow rate, and uranyl ions concentration were monitored over time.
In relation to prior studies using column percolation tests, Yong (2001) adopted a
hydraulic gradient of the order of 55, Morandini and Leite (2015) adopted a
hydraulic gradient of the order of 50, based on recommendations of the standard ASTM D 4874 (American Society for Testing and Materials [ASTM], 1995) it could be used a
hydraulic gradient of 24, and Rojas, Consoli, and Heineck (2007) worked with a maximum
hydraulic gradient of approximately 92.
Pressure drop at the rated flow rate can vary, depending on where the cooling coil is located in the system
hydraulic gradient curve.
WhereQ is the water discharge, K is the hydraulic conductivity of the soil (soil permeability), A isthe cross sectional flow area and i is the
hydraulic gradient which is given by the following equation:
It was determined that in the course filtration at higher
hydraulic gradients, clay mineral particles re-orientate parallel to the water flow lines, and, with the
hydraulic gradient dropping down, clay particles do not return to the initial position.
v--velocity of flow in the sample [m/s], i--hydraulic gradient [m/m] where
hydraulic gradient is: