Electromagnetic Soil Heating Using Magnetic Nanoparticle-Coated Geotextiles: Fid-Bau Portal

Electromagnetic Soil Heating Using Magnetic Nanoparticle-Coated Geotextiles

Kim, Ijung / Best, Caroline / Kim, Seunghee

Application of electromagnetic heating has been primarily focused on the biomedical area (e.g., hyperthermia therapy), which has recently extended to environmental and petroleum engineering fields. In the meantime, conventional soil heating, often a preferred option for a number of practical applications such as remediation, fertilization, and sterilization, has been carried out by the installation and operation of the heating source and the heat transfer system. In this background, as an innovative and simple soil heating method, electromagnetic soil heating is investigated in this study. The magnetic nanoparticle-coated geotextiles were prepared via the chemical co-precipitation method to synthesize magnetic nanoparticles and to coat them onto the geotextile simultaneously during the nanoparticle synthesis process. An immediate electromagnetic heating of the magnetic nanoparticle-coated geotextile ascertained the successful coating of magnetic nanoparticles. The prepared geotextile was then inserted into a soil medium, and then exposed to the alternating magnetic field that is generated by the induction heating coil. As a result, a noticeable temperature increase in the soil medium (6~7°C) was observed over a short period of time (5 min). A similar heating rate was observed for both sand and clay specimens. The heat transfer to the surrounding soil functions to prevent a drastic heating of geotextile, which helps to not only warm up the surrounding soil but also hinder any mechanical deterioration of the geotextile. Moreover, experimental results show that the heating performance was independent of the rinsing step, which suggests the fixation of magnetic nanoparticles on the geotextile is robust. Supporting numerical simulations suggest that the magnetic nanoparticle-coated geotextile heated up approximately with the rate of 65 W in the experimental setup of this study, which resulted in ~10°C and ~6°C temperature rise in the geotextile and middle of soil specimen, respectively. Such an innovative heating method can potentially provide additional functionality to geotextiles as an attractive option for soil heating.