Researchers at Rice University and Vanderbilt University have developed an electrochemical treatment process that simultaneously removes salts from industrial wastewater while selectively recovering valuable metals, offering a potential alternative to conventional treatment methods.

Published in Nature Water, the research demonstrates how electrochemical ion pumping (EIP) can be programmed to desalinate wastewater while separating dissolved metals such as copper. The technology is designed to address wastewater streams from industries including electronics manufacturing and metal processing, where high salinity and heavy metals often occur together.

Unlike conventional approaches that typically require separate desalination and metal removal processes, the EIP platform uses electrical potential to control whether specific metal ions remain captured on an electrode or pass into a receiving stream. Researchers said the approach could reduce reliance on chemical precipitation methods that generate metal-laden sludge and simplify treatment compared to reverse osmosis, which removes salts but does not selectively recover metals.

In laboratory testing with synthetic wastewater, the system removed 90% of dissolved salts while retaining nearly all of the copper on the electrode. Additional tests using wastewater containing sodium, copper and nickel removed 85% of the salt and more than 92% of the metals, with copper recovered at approximately 96% purity relative to nickel.

The researchers said the technology could support both water reuse and resource recovery by allowing treatment facilities to recover valuable metals while reducing the volume of hazardous waste generated during industrial wastewater treatment. Further development will be needed before the technology is ready for commercial-scale applications.