Efficient and Stable Cr(VI) Remediation Using Enhanced\nElectrokinetic Method with a Natural Magnetite/Pyrrhotite Composite

Cr(VI)\ncontamination is a significant environmental issue, whereas\nexisting remediation technologies, whether physical, chemical, or biological,\nhave many limitations, such as extensive engineering work, high energy\nconsumption, secondary pollution, and incomplete treatment. Here,\nwe report a Cr(VI) remediation method that integrates a natural magnetite/pyrrhotite\ncomposite (NMPC) with electrokinetic processes to enhance the remediation\nefficiency and stability, in which the electron-donating ability of\nNMPC was utilized to boost the reduction and immobilization of Cr(VI).\nThe XRD analysis shows that NMPC is composed of magnetite and pyrrhotite.\nA highest 100% Cr(VI) removal efficiency and a TCr removal efficiency\nover 95% are achieved when treating Cr(VI) contaminants. The remediation\nstability analysis shows that the redissolution ratio of Cr(VI) in\nthe NMPC-enhanced treatment decreased by more than 62%, indicating\nthat the Cr-containing products were stable and resistant to releasing\nCr. Furthermore, the Cr-containing products are analyzed by SEM-EDS,\nRaman, XRD, and XPS. The results show that the distribution of Cr\nand Fe is highly correlated and Cr is immobilized in the mineral phase.\nThese results demonstrate that NMPC enhances the removal of Cr(VI)\nand promotes the immobilization of Cr, thus reducing the risk of Cr\nreoxidation and contributing to a more durable remediation effect.