Author(s): Kumars Ebrahimi; Hossein Khalafi; Mehran Ghahremani Tabaar
Linked Author(s):
Keywords: Environment; Physical Model; Hydrus-2D; MTBE
Abstract: Environmental issues including pollutions detection and control is one of the most important challenges human communities currently face today. Methyl tertiary-butyl ether (MTBE) is a chemical compound which is used as an additive in unleaded gasoline. The MTBE is produced in very large quantities, a colorless liquid and dissolves rather easily in water. It gets into groundwater and remains in that for a long time. Drinking or breathing of MTBE can be very harmful to human health. In this paper results obtained from laboratory studies of MTBE transport by water through a thin layer of unsaturated soil are reported. In order to achieve reliable results and evaluate the movement behaviour of the contaminant an idealized-Design model was constructed. Moreover, the physical model was used for the purpose of reproducing a numerical simulation of the physical model, involving the 2-D Hydrus software. The reasonable practical design criteria of the physical model were obtained from some initial tests which were conducted in the Hydraulics Laboratory at the University of Tehran. Then, the final experimental data were collected and recorded using the refined physical model and some other facilities in the Chromatography Laboratory at the Iran Atomic Energy Organization. For the purpose of the contaminant plume monitoring, soil samples were acquired from five points of the plume, with regard to the symmetric line, in different times. Then the MTBE was extracted from the soil samples in a special two-step procedure and following by that the MTBE concentrations were measured using Gas Chromatography method. The general spreading of the contaminant, established from the time series measured data. As mentioned above, the 2-D Hydrus software was then set up to simulate the MTBE transport for the physical model set up to assess the computational capability of the software in simulating of the phenomenon. Comparisons have been made between the computational predictions, using the software, and the laboratory measured results. Results indicate that, the numerical simulations gave an encouraging level of agreement with the measured data. However, there were some small discrepancies between these two data sets for the numerically predicted and measured results.
Year: 2013