Chemicals are everywhere. These burned wood chips might help change that.

Chemicals are everywhere, from cookware to cosmetics, clothing to carpets. Over the decades, chemicals have been building up in the environment, water and even our bodies.

Now, Canadian researchers say they have developed a practical way to remove toxic compounds from drinking water.

“This material does not decompose naturally,” said Johan Foster, an associate professor of chemical and biological engineering in the University of British Columbia's School of Applied Science and lead researcher on the team that developed the technology.

“They discovered [forever chemicals] They are found in everything from glaciers to mountain lakes to killer whales.”

But by soaking pieces of wood in a solution of iron chloride and burning them at high temperatures, Foster's team has been able to create a new type of activated carbon that can capture and destroy the permanent chemicals.

“We're purifying the water,” says Pani Rostami, a UBC master's student working on the project. “We're taking pollutants that are very bad for the environment and turning them into things that are not harmful.”

of The results, by researchers at UBC, were reported recently. In a peer-reviewed paper Nature Communication Engineering.

Widely used, widespread problem

Since the 1950s, Forever Chemicals have been used in a variety of household products and industrial processes for their water-repellent and stain-resistant properties.

The term “forever chemicals” refers to a group of more than 10,000 synthetic compounds formally classified as per- and polyfluoroalkyl substances (PFAS).

These are nearly impossible to break down using traditional methods and have accumulated in the environment for decades.

“You don't break it down in your body. You just can't break it down in sunlight,” Foster said, “so it just accumulates. It accumulates in the environment, in the water and in the human body.”

PFAS are bioaccumulative, meaning they are absorbed by living organisms faster than they can be broken down and excreted in the body.

“This bacteria is present in all of us,” says Jane Fowler, an assistant professor of environmental microbiology at Simon Fraser University, “and can be found in everything, including blood samples and breast milk.”

The eternal chemistry dilemma

Foster says Forever Chemicals has a unique and extremely stable chemical composition.

“The carbon-fluorine bond makes it very difficult to break down,” Foster says. “It's a wonderfully strong bond, and it makes this chemical not only a wonderful chemical, but a chemical that lasts forever.”

The carbon-fluorine bond is one of the strongest known in chemistry, and PFAS can have dozens of them, making them extremely difficult to break down.

Under normal conditions, breaking the strong bonds within PFAS molecules requires large amounts of energy, making disruption impractical.

“You are hot [PFAS-contaminated water] “When you heat it up to 370 degrees, it gets under a lot of pressure and starts to break down,” Foster said. “But what's particularly problematic for drinking water is that [PFAS are] It's such a small amount that it would be impractical to heat all drinking water to that temperature.”

Currently, the only way treatment plants can remove PFAS from drinking water is to Activated carbon and ion exchange technology.

“These technologies remove PFAS and capture it from the drinking water supply, but they don't eliminate the problem,” said Inder Singh, quality control manager for Metro Vancouver Water Services.

“The insidious nature of PFAS compounds means they are released directly into the environment.”

Trap and destroy

A new method developed at UBC aims to capture and remove PFAS without requiring large energy inputs.

“This is putting two technologies into place,” said Upal Ghosh, a professor of chemical engineering at the University of Maryland, Baltimore County.

“We're pleased to see these efforts moving forward. In the long term, we hope to have the ability to break down these compounds.”

Essentially, the iron-soaked burnt wood chips, or “biochar,” act as a more effective activated carbon, capturing PFAS molecules from water. The iron then acts as a catalyst, making it easier to break the strong carbon-fluorine bonds.

“PFAS compounds attach to the catalyst and then react and break down into smaller, harmless compounds that don't affect humans,” Foster said.

When ground into a powder, the material was able to destroy more than 85 percent of perfluorooctanoic acid (PFOA), a common PFAS, within three hours. These results were collected under low levels of UV light to simulate ambient sunlight, although the efficiency of the reaction is only slightly reduced in darkness.

“I think this is promising,” Fowler says, “not only can we get PFAS out of the water, but we can also start to break down the PFAS molecules so we're not just creating new waste.”

The team is now looking to scale up: They've found an industrial partner in British Columbia's Interior who can help them produce biochar, Foster said.

Health Canada takes 'unprecedented' steps to tackle PFAS

Last month, in an unusual move, Health Canada Tough new goals for PFAS levels in drinking waterWhile non-binding, it marks a policy shift from regulating each type of PFAS individually to addressing them as a group.

This follows the issuance of stricter restrictions in places such as: united states of america and european union.

These new goals are intended to complement official Health Canada guidelines issued in 2018 and 2019 that focused on only a few individual PFAS molecules.

These guidelines call for states and localities that regulate drinking water quality to limit concentrations of PFOS, a common type of PFAS, to 600 nanograms per liter — 150 times higher than the new U.S. limit of just 4 nanograms per liter.

“PFAS was one of those things, but it's rare and the science is evolving very quickly,” said Stephanie McFadyen, research manager for Health Canada's water quality program.

McFadyen said the goal is for Health Canada to communicate new evidence to provinces and territories while continuing to develop new guidelines, a process that typically takes four to seven years.

“So doing nothing, or at least pretending to do nothing, didn't seem like a reasonable approach.”

McFadyen stressed that part of the problem is a lack of data: Few municipalities regularly test for PFAS in their drinking water, but that's changing, he said. Health Canada, meanwhile, has relied on academic research.

for example, A study of Quebec tap water PFAS was detected in 99.3 percent of the samples.

“I think it surprised everyone,” McFadyen says, “It's in everything, it's everywhere. The only thing that's probably comparable to the scale of this problem is plastic.”

Dozens of hotspots across Canada

In Canada, most PFAS Hotspots These are located in heavily used industrial areas or around airports and Canadian Forces bases.

“Anywhere fire drills have been conducted and foam has been used,” Fowler explained, “until very recently, those types of foams have had very high concentrations of fire suppression agents.”

Many of these hotspots A CBC investigation revealed In 2020.

In recent years, several Canadian cities have also been in the spotlight for high levels of PFAS in their drinking water.

Health Canada's McFadyen said nearly every community could be affected when it comes to drinking water sources: Groundwater tends to be the most affected, but surface water can also be contaminated.

Metro Vancouver's 'unique' drinking water

But in Metro Vancouver, drinking water comes from protected mountain reservoirs.

“Metro Vancouver's drinking water is very unique. There's no industry, there's no commercial facilities,” says Singh of the Seymour Capilano Water Treatment Plant in North Vancouver. “So the only source of PFAS contaminants is airborne transportation. And unless there's a specific industry that's releasing it into the air, the risk is minimal.”

Since Metro Vancouver began semi-annual testing for PFAS, Levels were consistently below detection limits.

Singh said as long as these levels remain low, there is little reason for Metro Vancouver to deploy this kind of PFAS removal technology, but he acknowledged that the science is changing rapidly and the district needs to be ready to change with it.

“This is a matter of public safety and public health, and any prudent utility would comply with these regulations and meet their requirements.”