There’s no such thing as too many good ideas when it comes to making more clean water for our thirsty planet. The latest: a customizable electric filtration device that zaps contaminants clear out of the water. The device’s creators describe it in the journal Energy and Environmental Science.
There are currently three basic types of water filtration processes: membrane filtration, like the type in your water pitcher; electrodialysis; and capacitive deionization. All three methods work quite well, but the first option is expensive and can’t catch small amounts of contamination, and the latter two require lots of electricity to run—all significant obstacles in impoverished regions where resources are already scarce.
So a group of chemical engineers from the U.S. and Germany teamed up to make something better. Their solution is surprisingly simple: a set of electrically charged dipsticks that can target pesticides, chemical waste, and even prescription drugs.
Each dipstick is an electrode coated with what are called Faradaic materials. The coatings can be treated to make them either positively or negatively charged, and to resonate with—and thus zap—specific molecules.
To test the dipsticks, the researchers immersed them in water contaminated with very low doses of ibuprofen and different types of pesticide. The setup worked beautifully, targeting and eliminating pollutant molecules even at levels as low as a few parts per million.
The new technology is also incredibly energy efficient, requiring so little energy that it could easily be powered by solar panels in remote areas with no other access to electricity.
Matthew Suss of the Technion Institute of Technology was not part of the development team but calls it “highly significant.” Speaking in a statement, he said the technology “…extends the capabilities of electrochemical systems from basically nonselective toward highly selective removal of key pollutants.”
The next challenge will be scaling the device up to treat higher quantities of water outside the lab. “As with many emerging water purification techniques,” Suss added, “it must still be tested under real-world conditions and for long periods to check durability."