Remediation of Pb- and, Cd-contaminated soil through magnetic-modified eluent synergetic freeze-thaw and washing.

For the improved washing efficiency of clayey soil, utilized magnetization technology was used in this study to enhance the physicochemical properties (e.g., viscosity, surface tension, and contact angle) of the eluent. Lead- and cadmium-contaminated clayey soil was used as the research subject in an experimental study aimed to enhance the heavy metal removal efficiency through a magnetized modified eluent and freezing-thawing effect by using EDTA as the eluent. The magnetization test results indicate that the EDTA solution's viscosity, surface tension, and contact angle decrease after magnetization, thus improving the wettability, enhancing the eluent's full contact with heavy metal pollutants, and consequently increasing the removal rate. The results of the freezing–thawing and washing column test show that magnetization reduced the viscosity of eluent, decreased soil seepage or migration resistance, and increased moisture migration during freezing. After three cycles of freezing-thawing and washing, the removal rates for Cd and Pb were 79.35% and 70.38%, respectively. The technology of magnetized eluent is facile to operate and serves as an efficient, cost-effective, and eco-friendly auxiliary method for increasing the efficiency of freezing–thawing–washing processes, offering a novel approach for soil remediation. • The combined magnetization technology and soil washing method for remediation of heavy metal contaminated clay soils is proposed. • Based on enhance the physicochemical properties of the eluent to improve removal efficiency. • To provide basis for remediating heavy metal by magnetization technology. [ABSTRACT FROM AUTHOR]