Scientists at Washington University in St. Louis have found a new way of treating water contaminated by nuclear waste.
These strides could be useful not only in the cleanup of former nuclear sites, but also in the treatment of mine water, since it can be contaminated by uranium, a consequence of gold mining, according to The Times of South Africa.
The researchers “discovered a new efficient way of using calcium phosphate to react with and immobilise uranium. In their experiments, researchers first determined the exact level of calcium in the contaminated water. They then added the phosphate, which formed calcium phosphate, chemically binding and neutralising the uranium,” the report said.
The study built on and expanded previous research, according to Washington University:
Past field studies, including one at the Hanford Site in the state of Washington, focused on an in situ solution that injected phosphates directly into contaminated groundwater. Remediation efforts were not fully successful, because the scale of overlap for the calcium, uranium and phosphates was limited.
Daniel Giammar, lead researcher on the project, weighed in on how his team pushed beyond these limits.
“A challenge with subsurface remediation is finding the right way to bring the necessary ingredients together in a poorly-mixed system,” Giammar said. “In the field-scale test, much of the added phosphate never reached the uranium because it precipitated out near the injection well. The solution is to figure out scenarios where it is possible to send the phosphate to where the uranium is, and other scenarios where the phosphate can be added to a location where the natural groundwater flow will bring the uranium into contact with it.”
Uranium mining during the Cold War played a major role in contaminating water sources in the U.S., particularly on reservations. Many of the companies responsible for mining no longer exist, according to VICE News. Eight companies that remain active, including Chevron and General Electric, are investigating and cleaning up the mines they are responsible for, the report said.
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