Gradiant Corporation, an MIT spin-off company based in Woburn, MA, is testing a new process to make it easier to treat fracking wastewater called: carrier gas extraction. Gradiant is teaming up with Texas oil company Pioneer Natural Resources to put the technology into practice, the MIT Technology Review reports.
"The water is pretreated to remove oil and grease residue and solid particles. The company heats the saline water and sprays it into a porous material with a large surface area, saturating air with water vapor. This water-saturated air is then pumped up through tiny holes in a series of shallow, water-filled trays," the report says.
"As bubbles pass through the water in the trays, the water vapor in the bubbles condenses and joins the water it is passing through, creating more fresh water. This so-called 'bubble column' allows the company to condense water vapor without needing expensive metal heat exchangers."