Nano-scale zerovalent iron for subsurface remediation: experiences of Dekonta

This contribution relates to application of nanoscale zerovalent iron (NZVI) for the subsurface remediation. Results of experiments focused on objective comparison of both migration properties of various types of the NZVI in porous media and reactivity of NZVI with various contaminants are presented. Obtained results indicate that it might be a problem to keep good migration properties of NZVI in porous media together with its high reactivity. Reactivity of NZVI up to two orders of magnitude higher than reactivity iron particles of normal size (chips, shavings) has been proven. Original design of mixing apparatus for NZVI aqueous suspension preparation and injection into the subsurface was developed and successfully tested. Furthermore, results of NZVI in-situ application on chlorinated hydrocarbons contaminated site are presented. Chlorinated hydrocarbons concentrations were substantially lowered in groundwater after NZVI injection, however, rebound effect was observed. NZVI application can be recommended as an efficient method for in-situ remediation mainly at less-contaminated sites where source of contamination