Selenium (Se) pollution, which harms aquatic ecosystems and wildlife and can be toxic in humans and animals, is found in natural water bodies worldwide. Current biological treatment to remove Se from wastewater is expensive, produces non-biodegradable sludges, has a large carbon footprint, and is sensitive to chemical and environmental limitations. Direct electrochemical reduction using gold or graphite electrodes offers advantages, but gold is too expensive, and graphite cannot achieve the Environmental Protection Agency (EPA)’s maximum contaminant level for reduction. Lawrence Berkeley National Laboratory’s (LBNL’s) Nickel-Iron Electrode, an R&D 100 winner from 2024, effectively removes aqueous selenite from wastewater at a cost substantially lower than its competitors. It is easily manufactured and processed, has high catalytic activity and selectivity, is stable in aqueous environments, uses less energy than competing products, and creates no pollution. The Fe-Ni foil that can reduce Se(IV) concentrations to the EPA’s limit is commercially available, ensuring material scale-up. Replacing the Au electrode with Ni-Fe significantly decreases capital and operational costs, making the global adoption of this technology possible, especially in developing countries. The technology was highlighted on the Berkeley Lab’s website in 2023.
