Matteo Masi

Multispecies reactive transport modelling of electrokinetic remediation of harbour sediments

We implemented a numerical model to simulate transport of multiple species and geochemical reactions occurring during electrokinetic remediation of metal-contaminated porous media. The main phenomena described by the model were: (1) species transport by diffusion, electromigration and electroosmosis, (2) pH-dependent buffering of H+, (3) adsorption of metals onto particle surfaces, (4) aqueous speciation, (5) formation and dissolution of solid precipitates. The model was applied to simulate the electrokinetic extraction of heavy metals (Pb, Zn and Ni) from marine harbour sediments, characterized by a heterogeneous solid matrix, high buffering capacity and aged pollution. A good agreement was found between simulations of pH, electroosmotic flow and experimental results. The predicted residual metal concentrations in the sediment were also close to experimental profiles for all of the investigated metals. Some removal overestimation was observed in the regions close to the anode, possibly due to the significant metal content bound to residual fraction.

Flood risk assessment of environmental pollution hotspots

Abstract The potential spread of pollutants stored in environmental hotspots such as wastewater treatment plants, waste handling facilities, contaminated sites, etc., is among the adverse consequences of floods. This aspect has been rarely examined with a risk-based approach, although required by the European legislation. In this study, a method for estimating flood risk caused by environmental hotspots is developed. Risk includes flood hazard, hotspots exposure, and the expected severity of the environmental impacts, obtained as the combination of vulnerability of the surrounding environment and pollution potential of the hotspots. The assessment is performed at catchment scale on a geographical basis, using open data, available from databases of public bodies and environmental agencies. Risk maps obtained by the application of the developed method are produced for the Arno river catchment in Tuscany (central Italy). The area hosts approximately 1750 environmental pollution hotspots among which 5–10% have been classified at high risk.