Enhanced Electrokinetic Remediation of Cadmium (Cd)-Contaminated Soil with Interval Power Breaking

Abstract

This study compared electrokinetic (EK) remediation with and without interval power breaking in the removal of total and plant available cadmium (Cd) in the soil. Two laboratory experiments, i.e. EK remediation with interval power breaking (24–12 h power-on-off cycles) and conventional EK remediation (continuous power supply), with the same accumulated time (192 h) of power supply, were conducted to remove soil Cd. After the EK remediation with interval power breaking, the total Cd removal efficiency in the soil rose to 38%, in comparison to 28% after the conventional EK remediation. As for the plant available Cd, the removal efficiency was enhanced from 52 to 63%. Additionally, the electric current during the EK remediation and electric conductivity after the EK remediation were higher in the soil treated by interval power breaking, which indicated an enhanced desorption and/or migration of charged species. It further meant that the higher removal efficiency of soil Cd by interval power breaking could be related to the enhanced desorption and/or migration of Cd species. This study indicated that both conventional EK remediation and EK remediation with interval power breaking were effective methods to remove soil Cd but EK remediation with interval power breaking was more efficient.

Contamination and remediation of contaminated firing ranges—an overview

“…Electrokinetic remediation is a class of in situ physical remediation technology, mainly by applying a small electric current between the anode and cathode in the contaminated soil to achieve the removal of pollution (Saini et al, 2021). Cai et al (2022) found that both continuous power supply and intermittent power failure can effectively remove Cd contamination from soil through a comparative experiment of soil electrokinetic remediation, in which the efficiency of remediation with intermittent power failure is higher. In addition to effective remediation of inorganically contaminated soils, electrokinetic remediation technology can be used in combination with surfactants, nanoparticles and oxides for effective removal of soil organic matter (Cameselle and Gouveia, 2018).…”

Mitigating Metal/Metalloid Stress in Crops: Strategies for Sustainable Agricultural Resilience

“…EKR is particularly adept at treating fine-grained soils with low permeability, where conventional remediation methods struggle to achieve efficiency. The technology operates on principles including electromigration, electroosmosis, and electrophoresis, which collectively enable the movement of contaminants toward strategically placed electrodes in the soil [53][54][55].…”

“…Recent innovations such as interval power breaking have been adopted to enhance EKR's efficacy. This technique, which involves alternating cycles of power-on and power-off, improves the desorption and migration of ions, significantly increasing the removal efficiency of contaminants like Cd from soils [53]. Furthermore, introducing organic acids as facilitators has bolstered the solubilization and extraction of metal/metalloids, enhancing the overall effectiveness of the EKR process [57].…”