Fig. 1: Concept of the high-temperature electrothermal process (HET) for soil remediation.
From: High-temperature electrothermal remediation of multi-pollutants in soil
a Schematic of the HET process, combined with vacuum extraction well. The vacuum piping and insulation blanket remain standard to known thermal remediation methods, but in the case of HET, the electrodes provide a rapid voltage pulse for electric heating, rather than long-duration heat injection. The soil is premixed in place, with biochar or other conductive carbon to provide sufficient conductivity. b Schematic showing the removal of heavy metals by reduction and vaporization, and the removal of persistent organic pollutant (POP) by graphitization for PAH. c Current curve at an electric input of 100 V for 1 s. d Real-time temperature curve of the soil sample at an electric input of 100 V for 1 s. e Comparison of the HET with other thermal remediation processes, including thermal conduction heating (TCH), electrical resistance heating (ERH), and steam-enhanced extraction (SEE). While operated at lower temperatures, the latter methods require long treatment periods.
