Author(s): Kumars Ebrahimi; Mohammad Reza Nazem; Zahra Mardani; Shahab Araghinejad; Abdolmajid Liaghat
Linked Author(s):
Keywords: Dispersion coefficients; Fickian second law; Physical model; Tracer
Abstract: The world's urban population growth, indiscriminate use of fertilizers and chemical poisons are actually threatening groundwater resources. The main target of this paper has been tracking of distribution of a conservative tracer in a porous media and in a laboratory-scale model, to estimate the longitudinal and transverse dispersion coefficients. In this study non-cohesive sands were used to create the porous media body in the laboratory model with a grain diameter of 1-2.5 mm. Salt (NaCl) with concentrations of 5,7. 5and 10 g/l were used as a tracer. The results of 5g/l concentration tests are reported in this paper. An EC-meter apparatus was used to measure the EC values of the tracer to monitor its plume migration. Then the collected and recorded EC data were used to calculate the tracer concentration data in different points over time, for each test. The calculated concentration data were compared with values which were obtained from the analytical solution using Fickian second law. According to the results, for instance, in the case of 5 g/l of the tracer, the obtained values of the longitudinal and transverse coefficients are equal to 3.36e-6 and 6.58e-7respectively.
Year: 2018