The researchers, from the Chinese Academy of Sciences, already knew that a nanomaterial known as nano-magnesium hydroxide (nano-Mg(OH)2) could remove some metals and dyes from wastewater. It was also known that the rare earth elements in wastewater tend to be very diluted, and thus quite difficult to remove in a practical, inexpensive fashion.
Recycling valuable materials used in TVs, car batteries, cell phones.