March 21 (UPI) -- Every day, the oil and gas industry in the United States generates 2.5 billion gallons of produced water. The water isn't safe to be used by households, and current commercial treatments use lots of energy and fail to remove all the contaminants.
Researchers at Purdue University have developed a new purification technique that is energy efficient and effective at removing traces of oil and contaminants from the produced water. The method uses a combination of light and activated charcoal foam to cleanse the contaminated water.
"This is a simple, clean and inexpensive treatment process," Ashreet Mishra, a graduate research assistant at the Purdue's Northwest Water Institute, said in a news release. "I have seen in my home country of India how people suffer for the want of pure water, and we as researchers need to do as much as we can to help."
Solar light works to heat and activate the charcoal foam, which absorbs oil and other contaminants. Tests proved the technique purifies produced water to the EPA's clean water standards for industrial sources.
After purification, scientists measured total organic carbon of 7.5 milligrams per liter in the water. Researchers were also able to recover 95 percent of the oil absorbed by the charcoal foam.
"This is the first-of-its kind method to do this purification in a single step simultaneously via a perforated foam," Mishra said. "Our process is able to address the cost and energy aspects of the problem."
Researchers have previously used coffee-infused foam to purify water contaminated with lead. Different foam materials can be deployed to react with water and separate out unwanted molecules. The tiny pockets of air inside the foam trap and hold the removed contaminants.
Mishra and her research partners claim the charcoal foam could be created at scale and integrated into current water filtration systems. The team of scientists presented their work at this year's annual Produced Water Society conference.