Dual Electroactivation of Peroxymonosulfate for Heavy\nMetal Complexes Decomplexation and Simultaneous Resource Recovery

The\nefficient removal of toxic heavy metals chelated with coexisting\norganic ligands and simultaneous recovery of heavy metals are highly\ndesirable but remains challenging. Herein, we report a strategy of\ndual electroactivation of peroxymonosulfate (PMS) to efficiently decomplex\na metal complex and simultaneously recover heavy metal in simulated\nwastewater and real electroplating effluents of heavy metal complexes\ncontamination. The synergistic activation of PMS on cathode and anode\ncould achieve 99% dissociation of copper ethylene diamine tetraacetate\n(Cu(II)-EDTA) and 99% recovery rate of the released Cu ions via in\nsitu deposition on cathode with a record energy efficiency of up to\n58.18 g kWh<sup>–1</sup>. A series of investigations demonstrate\nthat the boosted generation of free radicals such as hydroxyl radicals\n(·OH), sulfate radicals (SO<sub>4</sub><sup>•–</sup>), superoxide radicals (·O<sub>2</sub><sup>–</sup>),\nand singlet oxygen (<sup>1</sup>O<sub>2</sub>) in the dual electroactivation\nsystem play important roles in the Cu(II)-EDTA dissociation process.\nFurthermore, the dual electroactivation strategy could also achieve\nexcellent dissociation efficiency and metal recovery rates for Ni\nand Cr complexes, and it is capable of achieving complete treatment\nof actual wastewater containing copper complexes. This study provides\nan effective strategy for the removal of heavy metal complexes and\nthe heavy metal recovery.