Researchers have developed an electrochemical technique that removes salt while recovering valuable metals from industrial wastewater, reducing waste, improving water reuse and resource efficiency.
Researchers at Rice University, working with collaborators from Vanderbilt University, have developed an electrochemical ion pumping (EIP) platform that simultaneously removes salt from industrial wastewater while selectively recovering valuable dissolved metals. The study, published in Nature Water, demonstrates a potential alternative to conventional treatment methods that typically address desalination and metal removal separately.
Industrial wastewater from sectors such as electronics manufacturing and metal processing often contains both high salt concentrations and dissolved metals. Existing treatment approaches generally require multiple processing stages, produce hazardous sludge or brine, and increase operating costs. The new EIP system is designed to tackle both challenges within a single process.
The technology uses electrode potential as a programmable control mechanism to determine whether metal ions remain captured on an electrode or continue into a receiving stream. Rather than relying on repeated solution switching, the platform enables ions to move continuously through the system while maintaining stable operating conditions and improving control over separation.
In laboratory testing with synthetic wastewater containing sodium and copper, the researchers reported that the system removed around 90% of the salt while capturing nearly all of the copper on the electrode. In further experiments involving sodium, copper and nickel, the platform removed 85% of the salt and recovered more than 92% of both metals. Copper remained on the electrode, while nickel was directed into the receiving stream, producing copper with approximately 96% purity relative to nickel.
The researchers believe the approach could support industries seeking to reuse water while recovering valuable metals from waste streams. By reducing downstream purification requirements and hazardous waste generation, the technology may improve resource efficiency and lower treatment costs. Future work will focus on advancing the system for broader industrial wastewater applications.
