Unshelled M. oleifera seeds (left), shelled seeds (middle), crushed seeds before protein extraction (right). Photo: Carnegie Mellon University College of Engineering.

In many developing nations, millions of people lack access to clean drinking water.

Specifically, 2.1 billion people lack safe drinking water, according to the United Nations.

Researchers at the Carnegie Mellon University are hoping to lower that number through a new water filtration medium called f-sand, by using sand and plant materials that are naturally available resources in many countries including developing countries.

The water filtration medium incorporates proteins from a plant native to India called Moringa oleifera.

Stephanie Velegol, a professor of Chemical Engineering at Penn State University and creator of the process, found that f-sand was able to wash out contaminants, allowing the water to remain longer by killing microorganisms and reducing turbidity. The f-sand filtration process also allowed for reuse, making it cost effective and efficient.

Previous processes have been established with the use of Moringa oleifera’s seeds, but those methods resulted in bacteria growth within 24 hours, only making the water drinkable for a short period of time and making it less accessible.

Although the filtration system was proven an effective process for clean drinking water, the researchers still had questions that needed to be answered surrounding the newly discovered process.

The researchers hypothesized that isolating certain proteins from the plant seeds would affect the filtration method, and possibly improve its effectiveness. Fractionation, another possible step in the process, would separate proteins in M. oleifera.

Bob Tilton and Todd Pryzybycien, professors of Biomedical Engineering and Chemical Engineering at Carnegie Mellon University, debunked their own hypothesis when they found that separating the proteins was unnecessary. The proteins did not absorb to the silica particles any more effectively than without separating the particles through fractionation. This furthers proves the method’s overall effectiveness, as less resources and processing is needed.

Tilton and Pryzybycien questioned whether the protein absorption process was affected by fatty acids and oils from seeds as M. oleifera are heavily sold commercially for its benefits. They found that fatty acid removal from the plant does not impact the filtration process.

The team determined that water hardness, which could range from soft and hard water conditions, also did not affect the absorption process, and the proteins’ process was not changed whether the water conditions were soft or hard.

This finding is significant as water conditions vary all over the world, it shows that this process can be used in varying conditions, making the ability for applying it in many different real world environmental situations a viable option.

Tilton and Pryzybycien concluded that the process is significantly cost effective as seed concentrations are not constrained to a limited amount. The seed concentration necessary for the process is a broad range that would create a reduced need for materials.

“It’s an area where complexity could lead to failure—the more complex it is, the more ways something could go wrong,” Tilton said. “I think the bottom line is that this supports the idea that the simpler technology might be the better one.”

The paper Moringa oleifera Seed Protein Adsoprtion to Silica: Effects of Water Hardness, Fractionation, and Fatty Acid Extraction was published in ACS Langmuir