Capacitive deionization (CDI), a technology in which a membrane made from electrode materials removes metal ions from water, has proved a promising technique for such next-generation water filters. Researchers from University of Chicago and Argonne National Laboratory envisioned the technique could be made even more efficient if they modified the molecular surface of the electrodes.

With support from University of Chicago's Joint Task Force Initiative, three researchers investigated the best way to alter these surfaces. Junhong Chen, Crown Family Professor of Molecular Engineering at UChicago's Pritzker School of Molecular Engineering and Lead Water Strategist at Argonne, collaborated with two Argonne colleagues: scientist Maria Chan and senior physicist Chris Benmore. Using experimentation, machine learning, and powerful X-rays, they developed a CDI device that adsorbed lead much more efficiently than before.

"Our future economy and national security really depend on the availability of clean water," Chen said. "The only way to really address this water challenge is to look into the re-use of water. This could potentially drive the recovery of resources that are important for clean energy applications and move us toward a circle economy for our society."

Finding the best functional molecular groups

Creating such a device could have wide-ranging implications. It could help remove lead from water to create safer drinking water, and it could help with the re-use of water by trapping phosphorus and lithium from a water supply, then releasing the phosphorus for use in fertilizer and the lithium for use in clean energy technologies.

Current technologies don't have the ability to selectively separate trace amounts of different ions within water, or can only do so at high cost. While some technologies can separate metals, they cannot fully distinguish one kind of metal ion from another. This is important, since while lead should be removed from drinking water, another metal, calcium, should be left in water, since it is beneficial for human health.

SOURCE

Attached link

Taxonomy

• Membrane Technology
• Capacitive Deionization
• Heavy metals
• Membrane