The assessment of adsorption, persistence, mobility, and “Effective Concentration” of the pollutants in brownfields, opens an important new topic on the strategy for the risk assessment and the selection of the morst suitable process for reclamation or for the safety of contaminated site. In recent years in fact, is strongly growing the interest of research on the distribution of chemical pollutants in various environmental matrixes (air, water, soil, biota), distribution heavily dependent on chemical and physical properties of the receptors-pollutants system.
A proper characterization of the contamination of the soil/ground water matrixes has to be able to quantify the various pollutant speciation by determining its allocation between fixed and labile fraction. This distinction is very useful in the selection of priorities for intervention and opens the way for innovative remediation techniques that count on the natural attenuation of persistent pollutants (heavy metals and POPs Persistent Organic Pollutants).
Passive probes are used (both commercial and of its own design/development), based on the technique of Diffusive Gradient Thin Film (DGT). In this technique the probe mimics the uptake of the pollutant by a generic biota (roots, earthworms, bacteria, etc.) that lives in contact with polluted soil or sediment. The informations obtained by this technique are used to determine kinetic information about the ability of the labile fraction of restore the concentration of the solution.