UNIVERSITY PARK, Pa. — Often called the “miracle tree” for its potential to provide food, fuel and water in harsh environments, the moringa oleifera tree is at the center of a new effort by three Penn State engineers to provide clean drinking water to the developing world.
Grant
The work — funded by a year-long, $10,000 Environmental Protection Agency P3 grant — seeks to optimize a water treatment process involving the moringa seed.
“P3 — that’s people, prosperity and planet. It’s for the developing world,” said Stephanie Velegol, instructor in environmental engineering and a co-principal investigator on the grant.
Darrell Velegol, professor of chemical engineering and the grant’s principal investigator, said, “The idea behind our use of the moringa is this: The seeds of the tree contain proteins. One of them is a cationic protein, a positively-charged protein, which contains a little peptide sequence that acts like a molecular knife. So this little molecular knife goes through the bacterial cell wall and kills it, basically slitting it open. We have data showing that for one type of E. coli bacteria, the moringa proteins not only take the bacteria out, but kill the bacteria too.”
And because the moringa protein is naturally positively charged, it’s able to wrap up sediment in water, which is mostly negatively charged, allowing the sediment to settle out of water very quickly.
The chemical engineer continued, “So the purpose of the grant scientifically is to identify what range of pathogens in water, whether it is a giardia protozoan or a pathogenic bacteria, does the moringa tree protein kill and what is the capacity of a certain amount of moringa seed in removing the sediment and the pathogens from the water?”
This summer, Velegol, along with his wife Stephanie and Richard Schuhmann, the Walter L. Robb Director of Engineering Leadership Development and a co-principal investigator on the grant, journeyed to Tiout, Morocco, to assess the tiny village’s water supply and to get a better understanding of the people and culture they hope to assist.
Water
The team found the village had a very clean water supply by standards in the developing world.
“I was impressed by the water source,” Stephanie Velegol said. Tests the team ran for hardness, iron and pH did not indicate any significant issues.
While on this particular trip, the engineers did not get the opportunity to test for bacteria or other biological contaminants, but a sanitary survey indicated that hygiene problems may reside with the storage of water subsequent to pumping.
Moringa
Stephanie Velegol said the moringa provides a possible solution that’s sustainable to places where access to clean water is difficult.
“This moringa grows naturally in harsh environments like the Moroccan desert,” she explained.
“It’s not a toxic chemical that we’re bringing in that we have to dispose of. In addition, we believe moringa can bring prosperity to the people because it’s not only something that has food and water purification, but there are oils within its seed that can be sold at a profit. So we thought it was a perfect mix.”
Schuhmann added that villages such as Tiout must truck in their water purification chemicals from a large city, which can be pricey. With moringa, “they can actually grow their own water treatment chemicals right here in the village,” he stated.
History
The idea to use moringa to purify water isn’t new. Indeed, Darrell Velegol said, “Moringa’s been used for thousands of years, from the best reports we can find, to clarify water. Women working on the Nile River would take the moringa seeds, rub them along their pots to clarify some of the water. We don’t know exactly how effective it was in that form, but that’s what they did.”
It was a conversation with Rick Bates, associate professor of ornamental horticulture, that gave the team the idea to look into the moringa tree. “He told me about this moringa tree that grows in very dry area where very little else grows,” Stephanie Velegol recalled.
“The leaves are highly nutritious and contain a large number of vitamins and minerals and even proteins. They can be fed to children to stave off malnutrition. But he also told me the pods of the tree contain seeds that purify water.”
Although the seed’s purification properties were fairly well known, a problem for the researchers is the fact that water purified by moringa seeds doesn’t stay clean for very long.
“There are other proteins and organic matter in moringa seeds. They act like food,” Darrell Velegol said. “They add biological oxygen demand that the bacteria then use as food. So any bacteria that are in the air and fall into the water will start to grow because they have this fresh source of food. So you can only store the water for about a day.”
To extend the shelf life of water cleaned by moringa seeds, the researchers believe that the answer might literally be under their feet.
Solution
“The idea Stephanie had is simple,” said Velegol. “We add the crushed moringa seed to water so that the proteins go into the water. Next we add sand, so that the active protein in the solution anchors onto the sand. The rest of the proteins and organic matter — called biochemical oxygen demand, or BOD — is rinsed away. The functionalized sand is now active, and we have data to show that this sand can clean water and kill pathogens. When you’re done, you just let the sand settle out of the water, so that the sand can be used again. That’s the core of the idea.”
Although a major challenge for the team will be to perfect the moringa water purification process, convincing people like Tiout’s villagers to use the technology is as formidable a task.
Schuhmann said Tiout’s population doesn’t perceive a problem with their water supply. Though people may get sick from time to time, the locals aren’t apt to blame the water.
Stephanie Velegol said, “Is there a way to convince people that there are things in the water that are making them sick and not something else when they can’t even see the pathogens?”
The work will continue this semester in all three faculty members’ engineering classes.
“We have a charge to the students to create a sustainable process with the moringa seed that will disinfect the water to an acceptable level,” Stephanie Velegol said.
