Assessment of quantitative imaging of contaminant distributions in porous media

In this article an experimental setup designed to assist in the characterization of complex solute transport problems in porous media is described. Glass beads representing the medium are confined in a 2-D transparent Perspex box and a water flow transports a fluorescent dye. Under suitable illumination, the dye emits visible light which is collected by a CCD camera. The image acquired by this non-invasive optical technique is processed to estimate the 2-dimensional distribution of tracer concentrations by using an appropriate calibration curve that links fluorescent intensity and solute concentration. Details about the dye choice and discussion about photobleaching are reported. An analysis of the experimental error on the concentration profile is also presented. A few recent results of a study on contaminant plume within a homogenous porous matrix constituted by glass beads having mean diameter of 1 mm or 2 mm shows the performance of constructed model.