In recent years, pomegranate-derived compounds have been shown to slow cellular aging, protect unborn babies' brains, and serve as additives in better automotive materials. Now, they've also been used to remove pharmaceuticals from wastewater.
Pharmaceuticals typically enter municipal wastewater streams as they're passed in patients' urine. Sewage treatment plants do help lower their levels, but a certain amount of the drugs still end up being released into local waterways along with the treated water. They may then harm aquatic life and potentially even people.
Previously, some groups have explored the use of nanoporous materials known as metal-organic frameworks (MOFs) to more effectively filter pharmaceuticals out of wastewater. While the materials have shown promise, the metal ions and synthetic organic molecules used in them are often costly and/or in short supply.
With drawbacks such as these in mind, scientists from Sweden's Stockholm University looked to a naturally occurring molecule called ellagic acid … and yes, it's found in pomegranates, among other places.
"Ellagic acid is one of the main building units of naturally occurring polyphenols known as tannins, which are common in fruits, berries, nuts, and tree bark," said PhD student Erik Svensson Grape. "By combining ellagic acid, which was extracted from either pomegranate peel or tree bark, with zirconium ions, we developed a new highly porous MOF which we named SU-102."
When SU-102 was tested on water that had already been treated at a local wastewater facility, it removed a significant amount of the leftover pharmaceutical pollutants that had been missed. And as an added bonus, in a process known as photodegradation, the material broke those pollutants down into innocuous elements when exposed to ultraviolet light.
"This has been a very exciting project as we got the opportunity to work directly with water samples from the treatment plant," said Grape. "We hope one day that SU-102 will be used on a bigger scale and also for other environmental applications."
A paper on the research was recently published in the journal Nature Water.
Source: Stockholm University