A new filtration material made from natural substances could become a new tool to remove "forever chemicals" from drinking water, according to a group of researchers who are developing the technology at the Massachusetts Institute of Technology in Cambridge.
The material, derived from silk and cellulose, has been shown to filter out PFAS and heavy metals, both of which pose health risks to humans.
"That's a huge advantage of our system, which is that we are using fully renewable, biodegradable and compatible material to resolve our long lasting problem," Yilin Zhang said, a postdoc at MIT who worked with civil and environmental engineering professor Benedetto Marelli, as well as four others, on the research project.
The findings were in a way accidental, the team said, explaining that they were first experimenting with the material for a potential anti-counterfeiting tag application — but "that's a whole other project," Marelli said.
The team had figured out a way to process silk proteins into uniform nanoscale crystals through a process the researchers describe as "environmentally-benign." When Zhang suggested that the material may also work at filtering out contaminants, the material at first did not work with the new application.
It was missing a key ingredient — cellulose, an organic compound that is a key part of plants' cellular structure.
"These are nano materials that are made with natural products which are in nature already," Marelli said. "So we simply learn the rule of nature of how to deal with them and then would reapply them to make them technical materials that can be used with a positive impact on the environment."
An added bonus? The filter material possesses antimicrobial properties that can keep it from spoiling, the researchers said.
Marelli and his team plan to take their findings on the new filtration material to the next level, by further testing and improving in hopes of eventually getting the technology into homes and water treatment plants.
PFAS — Per and polyfluoroalkyl substances — are synthetic chemicals that are used in common consumer goods, including non-stick cookware, food packaging, clothing, carpets and more. PFAS are also used to make firefighting foam more effective, according to the National Institute of Environmental Health Sciences.
They've been used in products since around the 1950s, but concerns about the long-lasting chemicals have grown in recent years. According to the NIEHS, PFAS levels can build up in people and animals through exposure to contaminated water, food, air and products containing it. A report by the CDC found that PFAS could be detected in the blood of 97% of Americans, the NIEHS said.
PFAS, which is a grouping that includes thousands of types of chemicals, have been associated with health risks involving cholesterol levels, antibody response, liver function, pregnancy issues and certain types of cancer, according to the
The Environmental Protection Agency has stated that it estimates a $1.5 billion annual cost associated with PFAS remediation, amid new regulations on the forever chemicals in drinking water.
Marelli and his team hope that someday their new filtration material can play a role in keeping our water clean.
"We're far away from having a solution that can reach the market, but we have a proof of principle," Marelli said. "And now we're going to move towards what is called a proof of concept, which would be something that looks like and the concept of a product that eventually could be further developed."
"Considering that the performance we achieved is already very promising, I think the pathway forward is to accelerate the nano-fabrication process so that we can meet the demand at scale," Marelli said later.
Other members of this research team include Hui Sun and Meng Li, Maxwell Kalinowski and Yunteng Cao.
