Simultaneous desalination and selective metal recovery enabled by potential-regulated electrochemical ion pumping

Highly saline industrial wastewaters containing heavy metals are common, yet no existing process can achieve both desalination and metal recovery in an integrated technology platform. Conventional desalination processes do not distinguish between heavy metals and background electrolyte and generate toxic brines with heavy metals, missing opportunities for resource recovery. Here we show that electrochemical ion pumping (EIP) has the unique capability to promote simultaneous desalination and metal recovery through programmable control of the electrode potential. As EIP transfers only a small amount of ions per half cycle via high-frequency circuit switching, the electrode potential can be maintained within a narrow window throughout operation, which allows redox reactions to be selectively activated or suppressed without interrupting continuous ion transport. At potentials above the Cu²⁺/Cu⁰ reduction threshold, the system desalinates only capacitively, with no metal deposition. Shifting the potential window to below this threshold triggers selective copper electrodeposition on the electrode while still performing desalination. In an asymmetric five-electrode EIP stack fed with a mixture of Cu²⁺, Ni²⁺ and Na⁺, positioning the potential window between the reduction potentials of Cu²⁺ and Ni²⁺ yielded selective Cu²⁺ capture on the electrode. These findings establish the electrode potential as a controllable operation parameter in EIP, providing an integrated platform for coupled water recycling and selective resource recovery from complex industrial brines.

Xu, L., Bello, O.A., Zaker, S.S.M.A. et al. Simultaneous desalination and selective metal recovery enabled by potential-regulated electrochemical ion pumping.
Nat Water (2026). https://doi.org/10.1038/s44221-026-00679-w

https://doi.org/10.1038/s44221-026-00679-w