MEASUREMENT OF IN SITU GAS-PHASE DIFFUSION COEFFICIENTS

摘要

Vadose zone in situ diffusion coefficients were measured at a former petrochemical plant (Chatterton research site) using a push-pull test and helium tracer. The test is relatively simple to perform, utilizes relatively inexpensive materials and field equipment, and requires only a few hours to complete each series of tests. In situ diffusion coefficients are derived using an analytical solution for spherical diffusion from a point source, assuming instantaneous injection of the tracer.