MTBE Movement Monitoring in Porous Media Using a Laboratory Model

Herein results obtained from a laboratory study of MTBE transport through a vertical layer of an unsaturated soil are reported. MTBE with a concentration of 200 mg/l was released on the top of the experimental model. The concentration of the pollutant was measured in time in different points using gas chromatography. Results indicated that, the vertical movement of the pollutant was more than the horizontal one. For instance, the MTBE concentration was 135 mg/l in a vertical distance of 5 cm, 10 minutes after the start of experiment and it was increased to 188 mg/l, after 133 minutes. For a point with 15 cm of vertical distance, after 25 minutes the concentration of MTBE was 120 mg/l and it increased to 185 mg/L after 133 minutes. Also for a point located in a vertical distance of 30 cm, after 100 minutes the concentration of MTBE measured equal to 127 mg/l and at the end of the experiment it increased to 148 mg/l. In conclusion it can be said that after 10 to 25 minutes after the adsorption capacity of the soil rechead its maximum and the movement of the pollutant began. With the beginning of the contaminant movement in the horizontal and vertical directions, the concentration of the pollutant increased and in the vertical direction this increase was more than that in the vertical direction. In fact, the diffusion velocity in the vertical direction was more than its velocity in the horizontal direction. Therefore, MTBE was more moveable with water and less adsorbing with soil.