Transport of Solute from a Fine-Grained Unit to a Coarse-Grained Host Under Pulsed-Pumping Fluid Dynamics: An Experimental Investigation

Pulsed pumping has the potential to be an effective alternative to continuous pumping pump-and-treat remediation techniques in porous media that exhibit a sharp material interface and tailing phenomenon is observed. Solute transport experiments performed in a soil column filled with a uniform coarse sand containing a uniform silt cylinder were conducted. Concentration measurements using saltwater as a tracer were taken employing time-domain reflectometry probes located throughout the column. The laboratory trials employed continuous pumping, 24-h periods of pumping followed by 24-h periods of no pumping, and 4-h periods of pumping followed by 24-h periods of no pumping. The experimental results suggest that pulsed pumping can achieve similar contaminant removal for a given amount of time as continuous pumping while pumping less water.