Heavy metal pollution treatment in industrial wastewater is crucial for protecting biological and environmental safety. However, the highly efficient and selective removal of heavy metal ions from multiple cations in wastewater is a significant challenge. This work proposed a pulse electrochemical method with a low-/high-voltage periodic appearance to selectively recover heavy metal ions from complex wastewater. It exhibited a higher recovery efficiency for heavy metal ions (100% for Pb²⁺ and Cd²⁺, >98% for Mn²⁺) than other alkali and alkaline earth metal ions (Na⁺, Ca²⁺, and Mg²⁺ were kept below 3.6, 1.3, and 2.6%, respectively) in the multicomponent solution. The energy consumption was only 34–77% of that of the direct current electrodeposition method. The results of characterization and experiment unveil the mechanism that the low-/high-voltage periodic appearance can significantly suppress the water-splitting reaction and break the mass-transfer limitation between heavy metal ions and electrodes. In addition, the plant study demonstrates the feasibility of treated wastewater for agricultural use, further proving the high sustainability of the method. Therefore, it provides new insights into the selective recovery of heavy metals from industrial wastewater.

中文翻译：

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脉冲/直流电化学法选择性去除重金属离子机理的见解

工业废水重金属污染治理对于保护生物和环境安全至关重要。然而，高效、选择性地去除废水中多种阳离子中的重金属离子是一个重大挑战。这项工作提出了一种具有低/高电压周期性出现的脉冲电化学方法，用于选择性地从复杂废水中回收重金属离子。与其他碱金属和碱土金属离子（Na ⁺、Ca ²⁺和 Mg ^{2+ ）相比，它对重金属离子（Pb 2+}和 Cd ^{2+ 100%，Mn 2+} >98% ）表现出更高的回收率在多组分溶液中分别保持低于 3.6%、1.3% 和 2.6%）。能耗仅为直流电沉积法的34%~77%。表征和实验结果揭示了低/高电压周期性出现可以显着抑制水分解反应并打破重金属离子与电极之间的传质限制的机制。此外，植物研究证明了处理后的废水用于农业的可行性，进一步证明了该方法的高度可持续性。因此，它为从工业废水中选择性回收重金属提供了新的见解。