This simple-looking white powder can get mercury-contaminated water 100 times as clean as any other method, for about half the cost. Each grain is actually a carefully engineered molecular sponge designed to absorb more than half its weight in mercury.
The product of more than 15 years of research, Thiol-SAMMS is made of silica molecules assembled into a spongelike pattern of holes, packing the surface area of a football field into just one teaspoon. Sulfur atoms, which can bind poisonous mercury, coat each of the minuscule holes. When the powder meets a tainted liquid, mercury seeps inside and bonds with the sulfur to instantly form a stable powder safe for landfills—the first time anyone’s been able to send mercury waste to the dump without an expensive separate step to neutralize the toxin.
SAMMS has successfully cleaned wastewater in a variety of settings, including a coal plant, an offshore oil rig and a chemical manufacturer. Four treatment tanks, each with a 10-pound load of the product, can treat about a million gallons of water. Soon SAMMS cartridges might help clean up lakes, streams and sewers. Thiol-SAMMS can also recover precious metals such as copper and gold, and researchers are now switching out the sulfur for other atoms so that it could mop up radioactive waste.