Electrochemical sulfite activation produces sulfur dioxide radical anions for bulk-phase arsenite reduction and passivation-free As(0) recovery

To address the global health crisis caused by the arsenic contamination of groundwater, the effective removal of the non-ionic form of arsenite (As(III)) is crucial but challenging. Electrochemical reduction offers a single-step route to convert As(III) into valuable elemental arsenic (As(0)), yet its efficiency is often compromised by electrode passivation due to the deposition of nonconductive As(0). Here, we introduce electrochemical advanced reduction processes to overcome this limitation by