Inductive detection and concentration measurement of nano sized zero valent iron in the subsurface

Nano sized zero valent iron (nZVI) can be used for the in-situ remediation of ground water contaminations by halogenated hydrocarbons or other contaminants. A novel approach is presented to detect nZVI and measure the concentration of nZVI in-situ during the remediation process. The presented inductive measurement system makes use of the magnetic material properties of nZVI. A specified magnetic field is generated locally in the aquifer and the magnetic flux density, which depends on susceptibility, is measured. Since the total susceptibility is very small, highly accurate measurements are necessary. Here, accuracy along with sensitivity is significantly improved by post-processing the measured data. Numerical simulations of magnetic fields and 3D visualisation techniques have been applied for development of the measurement technique. Finally, an experiment has been performed to verify the presented measurement method.