Commonly found in Mexican and Asian dishes, the leafy, bright green leaves of the cilantro plant might not only be tasty, but also help to purify polluted water. Scientist have recently discovered that, in developing countries, cilantro might actually help to absorb some heavy metals found in contaminated ground water.
Students, along with Professor Douglas Schauer of Ivy Tech Community College, were searching for a cheap and accessible way to filter ground water. They dried and crushed numerous wild plants while conducting their research, and found that cilantro was the most effective.
“And then we put that into a solution that has a known amount of lead in it," Schauer said. "That’s the metal we used as our test metal. Shake it up for a little bit, and then we let the particles settle out, and then we test the water to see how much lead is left behind.”
The researchers found that their cilantro filters were successful in removing many of the pollutants, especially nickel and lead.
Biosorbents are used in environmental cleanups, and help to remove contaminants like lead, arsenic, and other harmful metals. According to the research, the outer wall structure that makes up the cilantro plant is what makes the plant perfect for absorbing the metals.
"The organic toxins we can take care of pretty easily with a number of different methods, but the only way to really get rid of those heavy metals is to treat them with filtering agents like activated charcoal (like what's found in a Brita filter), but those types of materials are kind of expensive," said Schauer to CNN. “They are a little expensive for us to use, but they are very expensive to the people living in that region."
One method of purification using the cilantro filtering method is grinding up cilantro and passing water though it using a tube, which allows clean water to trickle out of the opposite end of the tube, ultimately leaving even cleaner water. Another method involves drying cilantro and putting it in tea bags, which are then placed in a pitcher of water, helping to take out some of the toxic metals.
Schauer believes that, since cilantro is a common herb in poor countries, it could substantially and positively affect access to water in many developing nations.
“Our hope is for somebody who lives in that region to simply be able go in their back yard and grab a handful of cilantro, maybe let it dry out for a couple days sitting on a rock in the sun, and then maybe a handful of that would purify a pitcher of water,” he said.