The method is rather unusual, as it mixes fracking wastewater with acid drainage from mining operations or with salty water. During this process solids are formed, including radioactive elements like radium, making them easily extractable from the water.
The processed water, now much cleaner, can be used for drilling a new well, explained Avner Vengosh, professor of geochemistry and water quality at Duke University and leader of the project.
For their study, Vengosh and his team of researchers mixed fracking wastewater from the Marcellus shale in Pennsylvania — an area where elevated radioactivity was recently detected — with acid drainage from local mines. The chemical reaction is natural and it works perfectly well. Metals and radium in the drilling wastewater connect with the sulfates, or salts, added to them within the first ten hours after they have been mixed. After the reaction and the extraction of the solids, the water can be reused.
Results from the research were published in last month's edition of the journal Environmental Science and Technology. However, the method is still to be field tested, the Association Press pointed out. Vengosh stated that it may not resolve all the problems but could offer an improvement.