Non-aqueous phase liquid characterization via partitioning tracer tests: a modified Langmuir relation to describe partitioning nonlinearities

The equilibrium interphase behaviors of alcohol partitioning tracers between NAPL and water are inherently nonlinear in nature. This nonlinearity may be described using an unfavorable form of the Langmuir partitioning relation with a good degree of agreement up to tracer mole fraction values of 0.3. The presence of co-tracers tends to move the equilibrium partitioning closer to Raoultʹs law. It may be possible to manipulate tracer tests systems to minimize the effects of nonlinearities through the use of co-tracers.