When water flows deep underground, it often dissolves inorganic substances from mineral deposits in the earth’s crust. In many regions, these deposits contain arsenic, a naturally occurring element that is colourless, tasteless and odourless. Although its presence is barely noticeable, prolonged exposure to arsenic-contaminated water can lead to gangrene, disease and many types of cancer, resulting in major loss of income for millions of people and even death.
Inspired by natural processes in soil that bind contaminants and filter them out, Case van Genuchten, a researcher in the Geochemistry Department of the Geological Survey of Denmark and Greenland, has been using iron oxides such as rust, which are abundant in soil, to filter out arsenic from groundwater. He leads experiments at the Department of Energy’s SLAC National Accelerator Laboratory that investigate low-cost methods of treating groundwater using only small amounts of electricity and steel or iron. The team’s most recent paper, which compares the arsenic-removing performance of different forms of rust has been published in Water Research — via Phys.org