University of Glasgow chemists have developed a unique system which uses ultrasound waves to remove up to 94% of Bisphenol A (BPA) from contaminated water samples without the need for additional chemicals.
Once properly scaled, the system could be integrated into water treatment facilities to help remove BPA from water supplies. The researchers also note that the system could potentially be used in industrial applications to remove other challenging pollutants from wastewater before it is discharged.
Outlined in the journal Ultrasonics Sonochemistry, the Glaswegian researchers describe a novel dual-frequency ultrasound device which generates millions of highly-energetic microscopic bubbles in contaminated samples. As the bubbles grow and collapse, they momentarily generate extreme temperatures and pressures, creating highly reactive "hot spots."
The conditions within the hot spots are extreme enough that BPA molecules break down into harmless substances such as carbon dioxide, safely removing the BPA from the sample. During lab testing, the team achieved 94% degradation of BPA samples during a 40-minute test.
"What we've been able to show for the first time is that ultrasound alone can offer an effective method of removing BPA from water," said Shaun Fletcher, the paper's first author. "Previous work in this area has required combining ultrasound with catalysts or other chemicals, but our dual-frequency approach is much simpler. You don't need to worry about removing your catalyst or further purifying your water by removing anything you've added to it in the treatment process."
"The key to this approach is the quality of the bubbles we're generating using ultrasound. We've shown in this that we can reliably generate bubbles with the conditions required to degrade BPA, building on previous research from the group which demonstrated its effectiveness in removing methylene blue, another common water pollutant," added Paper co-author Dr. Lukman Yusuf. "Ultimately, we'd like to expand this technique to help tackle a wide range of pollutants, including 'forever chemicals' like PFAs. We're currently in discussions with water companies to explore how this technology might be adopted in industry in the years to come."