When wastewater is polluted with heavy metals, it’s usually expensive and messy to decontaminate. But a new type of material, designed to precisely pull copper ions from water, demonstrates how water treatment could become more affordable—and how wastewater could become a way to sustainably source important metals.
While the process to clean wastewater today pulls out everything—including nutrients and essential minerals, not just contaminants—at once, forming a toxic sludge, the new technology, developed as a prototype by a team at the Department of Energy’s Lawrence Berkeley National Laboratory, targets and traps just the copper ions. “It’s kind of like a crystal sponge,” says Jeff Urban, the director of the Inorganic Nanostructures Facility in the Berkeley Lab’s Molecular Foundry and senior author of a new journal article about the technology. “When you put it into water, it opens up. Instead of grabbing everything, this is a sponge that’s very specific to copper because of the size of the pores and the stickiness of the pores for copper.”