Injection of zero-valent iron micro- and nano-particles for groundwater remediation: laboratory tests and transport modelling

Microscale iron particles (MZVI) have been recently studied for application in groundwater remediation. Thanks to their small size, they can be directly injected into the subsurface for a targeted treatment of contamination. The present work reports laboratory tests and numerical modelling concerning the mobility of MZVI suspensions in porous media. The efficacy of shear thinning “green” fluids in improving colloidal stability and mobility of MZVI was proved with column transport tests, injecting highly concentrated iron suspensions (20 g/L) dispersed in xanthan gum (3 g/L) and guar gum (1.5-4 g/l). A numerical model for MZVI transport was then developed (E-MNM1D, Enhanced Micro-and Nanoparticle transport Model in porous media in 1D geometry). It is designed as a tool for inverse modelling of laboratory transport tests, and as a support in the design of field-scale applications of MZVI and NZVI–based remediation.