Lead contamination in soil has emerged as a significant environmental concern. Recently, pulse electrochemical treatment (PECT) has garnered substantial attention as an effective method for mitigating lead ions in low-permeability soils. However, the impact of varying pulse time gradients, ranging from seconds to hours, under the same pulse duty cycle on lead removal efficiency (LRE) and energy consumption in PECT has not been thoroughly investigated. In this study, a novel, modified PECT method is proposed, which couples PECT with a permeable reaction barrier (PRB) and adds acetic acid to the catholyte. A comprehensive analysis of LRE and energy consumption is conducted by transforming pulse time. The results show that the LREs achieved in these experiments were as follows: PCb-3 s (89.5%), PCb-1 m (91%), PCb-30 m (92.9%), and PCb-6 h (91.9%). Importantly, these experiments resulted in significant reductions in energy consumption, with decreases of 68.5%, 64.9%, 51.8%, and 47.4% compared to constant voltage treatments, respectively. It was observed that LRE improved with an increase in both pulse duration and voltage gradient, albeit with a corresponding rise in energy consumption. The results also revealed that corn straw biochar as a PRB could enhance LRE by 6.1% while adsorbing migrating lead ions. Taken together, the present data highlights the potential of modified PECT technology for remediation of lead-contaminated soil, which provides an optimal approach to achieve high LRE while minimizing energy consumption.

This study specifically validates the migration patterns of lead ions under sodium ion stress in soil and concludes that a high concentration of sodium ions, when coexisting with lead ions, diminishes the migration rate of lead ions, consequently reducing the removal efficiency of lead ions. 1. Introduction: Treatment of lead-contaminated soil has become a prominent research concern, with electrochemical treatment (ECT) technology demonstrating significant potential in this regard. ECT not only overcomes the drawbacks of traditional technology of soil remediation, such as long remediation periods, low efficiency, and high costs, but also enables in situ remediation. However, the influence of varying concentrations of non-contaminant ions on the removal efficiency of heavy metal ions during electrochemical treatment remediation of different naturally polluted soils remains unclear. Therefore, investigating the impact of sodium ion stress on the migration of lead ions is essential. 2. Methods: This study applies a DC power supply connected to an experimental device. The device is made of plexiglass and consists of three compartments: one soil compartment and two electrolytic compartments. A multimeter is installed with a wire between the DC power and the soil reaction device for monitoring the current. 3. Results: This study indicates a significant influence of the presence of sodium ions on the migration of lead ions during ECT. A high concentration of sodium ions induces ion competition in the soil, hindering the migration of lead ions and causing a decrease in their migration rate. Additionally, the competitive interaction between sodium ions and lead ions has a pronounced effect on the efficiency of ECT, leading to a reduction in the removal efficiency of lead ions. 4. Conclusion: These results emphasize the importance of considering sodium ion stress in the electrochemical remediation of lead-contaminated soil and provide valuable insights for optimizing electrochemical remediation strategies.