Feasibility of electromagnetic soil heating using magnetic nanoparticle-coated geotextiles

This paper reports a new way of soil heating using a woven and a non-woven geotextile coated with magnetic nanoparticles (MNPs) that generate heat when exposed to a magnetic field. The MNPs were synthesised in the presence of the geotextile, creating and simultaneously coating the MNPs onto the geotextile. The fixation of MNPs on the geotextile was confirmed by direct observation by way of scanning electromagnetic images and an induction heating test. When the prepared geotextile was placed inside a soil medium, heat was generated immediately as the geotextile was exposed to a high-frequency alternating magnetic field, subsequently transferring heat from the MNP-coated geotextile to the surrounding soil. The soil heating performance was greater with the non-woven geotextile than with the woven one, which implies a better capacity to retain the MNPs with a rough surface. However, the effect of different soil types (sand and clay) on heating performance was insignificant. A follow-up study on the heat transfer on a field scale will provide a practical strategy for field application. Overall, the innovative heating method can potentially provide additional functionality to geotextiles as an attractive option for soil heating.