Arsenic is a natural component of Earth's crust and highly toxic in its inorganic form. The element is a cause of a global public health crisis, as it is present in groundwater and the drinking water consumed daily by millions of people in countries such as Bangladesh, China, India, Mexico and Pakistan.

Long-term exposure to high levels of inorganic arsenic can cause cardiovascular disease and cancers of the bladder and lungs. But now, scientists from Denmark have developed a new treatment that turns arsenic-rich groundwater waste into useful raw materials.

While current methods to clean arsenic from groundwater are successful, they create another problem—an arsenic-rich sludge that requires complex, specialist and expensive disposal methods. The residue is also a major environmental and health hazard if not disposed of properly.

In a study, published in the journal Science Advances, Kaifeng Wang and Case van Genuchten at the Geological Survey of Denmark and Greenland detail a two-step process to convert the hazardous sludge into a raw material for electronics,