Ferro zerovalente nanoscopico per la bonifica di acquiferi contaminati - Zerovalent iron for the remediation of contaminated aquifers

Nanoremediation technologies are based on the injection of reactive nanomaterials into the subsurface to promote in situ degradation of the pollutants. At present, it appears as a valid and very promising alternative to traditional and already established remediation technologies, such as Pump&Treat, In-Situ Chemical Oxidation (ISCO), air sparging and permeable reactive barriers. Due to their small size, nanoparticles (e.g. nanoscale zerovalent iron) presents a high reactivity and can be exploited to generate a reactive zone to treat a wide variety of contaminants close to their source. However, notwithstanding their high efficacy and good performances in laboratory tests, the field-scale application of nanoremediation techniques is still bound to overcoming some technical problems as the limited efficient delivery of these materials into the aquifer (in terms of radius of influence and homogeneity) due to poor injectability, the stability of colloidal suspensions and the relatively high cost of the reactive material. In this study the main advances achieved in the last years aimed to the scale-up of nanoremediation technology are presented.This study focusses on new materials, stabilization and injection of nanoparticles and some mathematical models used as support for the design of a large-scale remediation. Lastly, some of the results of real-scale nanoremediation developed in three European Projects (AQUAREHAB, NANOREM and REGROUND) will be presented to provide a picture of the technological level reached.