The oil industry has a complicated relationship with water. Huge oil spills have caused major environmental damage, and fracking has been shown to contaminate drinking water supplies. Part of the problem is the technology, which can only remove 95 percent of oil from water. The other five percent remains as tiny droplets that are time-consuming and costly to extract. Recently, a team from the University of Texas at Austin took a step towards solving that issue.
In a recent study published in the Journal of Nanoparticle Research, researchers developed a technique that uses magnetic nanoparticles to remove oil from water. Lead author Saebom Ko, a Department of Petroleum and Geosystems Engineering research associate, explained, “This new technique is really aimed at removing that little bit of oil in that water that needs to be removed before you can consider it treated.”
This technique, known as high gradient magnetic separation, has been previously used in the food and mining industries, but this one of the first applications in the oil industry. First, they designed a surface coating for the nanoparticles. The coating was made up of positively charged polymers, which attracted the negatively charged oil particles through the electrostatic force. After the nanoparticles have attracted the oil droplets, the mixture is removed from the water using a magnet.
The success of the technique has led researchers to look beyond than the oil industry. They hope that nanoparticles can be used to clean oil spills and even filter contaminants like lead from drinking water. Geosystems Engineering professor Hugh Daigle is optimistic about the flexibility of this technology. “The applications can extend far beyond the oil field because, with an appropriate surface coating design, you can take your magnetic core and coat it with whatever chemical you choose on the outside to stick to the target and pull it out with a magnet,” he said.
The team plans to test using nanoparticles to treat drinking water this summer. They’ll also work to industrialize the process to handle large volumes of water and oil. Finally, they plan to refine techniques to recycle and reuse dirty nanoparticles. This study was just the first step in crafting a technology with the potential to revolutionize the way water is treated around the globe.