water quality

Mason researcher measures troubles at the tap

Nathan Kahl — Mon, 29 Apr 2024 13:13:48 +0000

Mason researcher measures troubles at the tap Nathan Kahl Mon, 04/29/2024 - 09:13

Kirin Emlet Furst, an assistant professor in ��AV's Department of Civil, Environmental, and Infrastructure Engineering, recently received a National Science Foundation (NSF) CAREER Award to investigate how Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are transformed and persist in drinking water distribution systems (DWDS) that bring water to our spigots.

Kirin Emlet Furst. Photo provided

CAREER award funding is reserved for the nation’s most talented up-and-coming researchers. From the NSF website: “The Faculty Early Career Development (CAREER) Program offers NSF’s most prestigious award in support of early-career faculty who have the potential to serve as academic role models in research and education and to lead advances in the mission of their department or organization.”

PFAS are sinisterly known as “forever chemicals” because once created they do not break down, existing in water and soil—and even human blood—indefinitely. They have been used in numerous applications, including firefighting foams, metal plating, and food packaging, and spread easily through water and air.

This means, whether we like it or not, many of us are gulping down PFAS with every drink of water. To address this, the EPA recently released rules establishing limits on six PFAS in drinking water, affecting approximately 66,000 water systems, serving 90 percent of the country.

“PFAS really like interfaces between water and air and water and surfaces, so they stick to all sorts of stuff,” said Furst. “In DWDS, they may stick to the surface inside pipes and tanks, especially if there is biofilm growth or flaking of the inside material, giving them more to hold on to.” Furst said well-maintained DWDS typically won’t have such issues but knew of one water storage tank that had not been cleaned in 20 years, resulting in three feet of sediment on its floor. Such sediment, along with other conditions, may create conditions for PFAS accumulation and transformation.

Furst will test tap water across Northern Virginia, including on Mason's Fairfax Campus.

The focus of regulators and utilities is removing PFAS at the treatment plant, but in communities where exposure to PFAS is prevalent—near chemical plants, for example—Furst suggests there’s a likelihood that PFAS has been building up downstream, so to speak, in the DWDS.

“In Fairfax County the amount of time water could spend in the distribution system is as long as a week,” Furst said. “In some systems it’s going through miles and miles of pipes, with a lot of places for PFAS to hang out.”

There are more than 12,000 types of PFAS, and in the presence of certain microbial processes, unregulated precursor compounds can be transformed to the more toxic, regulated species like perfluorooctanoic acid (PFOA). Furst worries the new EPA rule, relying on measurements at treatment plants, won’t reflect the levels in water at household taps.

Furst’s lab will get samples from distribution systems from Northern Virginia utilities and she hopes to have a larger DWDS pilot on the Mason Fairfax Campus as part of the “Mason as a Living Lab” program. She hopes her findings will aid in solutions to minimize and mitigate PFAS contamination.

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Kirin Emlet Furst

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Topics

clean drinking water system

water quality

Department of Civil Environmental and Infrastructure Engineering (CEIE)

National Science Foundation

Research

Mason as a Living Lab

Strategic Direction

Mason engineers develop “rusty” coffee grounds to remove pollutants from water

Teresa Donnellan — Thu, 25 Jan 2024 19:03:14 +0000

Mason engineers develop “rusty” coffee grounds to remove pollutants from water Teresa Donnellan Thu, 01/25/2024 - 14:03

The most elegant solutions are sometimes the simplest, like using one waste product to eliminate another. By combining spent coffee grounds with iron oxide (aka rust), Mason engineers have created CoffeeBots, which can bind to several different pollutants in seawater before being removed via magnets.

From left to right: Jeff Moran, Amit Kumar Singh, and Tarini Basireddy pose with CoffeeBot samples.
Photo by Teresa Donnellan.

High school lab assistant Tarini Basireddy, post-doc Amit Kumar Singh, and assistant professor Jeff Moran recently published their findings in Nanoscale demonstrating how their invention, which they call “CoffeeBots,” can effectively remove three types of pollutants from seawater: oil, microplastics, and methylene blue.

Singh proposed creating CoffeeBots as a way for Basireddy to gain hands-on experience without having to interact with the many dangerous chemicals in Moran’s laboratory, which focuses mainly on developing artificial, self-propelled microparticles for different medical and environmental applications.

“Tarini and Amit developed a simple strategy to coat spent coffee grounds, which I brought from home after brewing my morning coffee, with iron oxide nanoparticles,” said Moran.

Coffee grounds have a porous, irregular surface, so they have ample surface area to which pollutants can bind, even with much smaller iron oxide nanoparticles attached, he explained. Moreover, because iron oxide is magnetic, a simple handheld magnet can both drive CoffeeBots through polluted water and remove them once they have absorbed the pollutants. Basireddy used Fourier transform infrared (FTIR) spectroscopy to confirm that the iron oxide nanoparticles had bonded to the coffee grounds.

“Tarini’s extensive research experience and skillset were crucial to the success of this project," Moran noted. She’s way ahead of where I was at her age.”

While using coffee grounds to clean up oil spills is not entirely new, this team is the first to show that moving CoffeeBots outperform stationary ones at removing pollutants, since moving CoffeeBots encounter pollutant molecules more often than stationary coffee grounds do. Making the coffee grounds magnetic has another benefit: Once the CoffeeBots are recovered, they can be reused several times with little loss in water-cleaning efficacy.

Methylene blue

The team demonstrates that
CoffeeBots are drawn to magnets.
Photo by Teresa Donnellan.

The team assessed how CoffeeBots fare in seawater polluted with methylene blue, a dye commonly used in textile production. In addition to being a carcinogen, Basireddy explained, methylene blue can cause serious health problems: “It can cause skin irritation, if there's too much in the water; it can cause a lot of digestive problems; it can cause nausea, fever, lots of symptoms.” She added that it can negatively impact marine life as well.

The team found CoffeeBots can be an effective solution for cleaning methylene blue from seawater, especially when they are first also loaded with ascorbic acid, which helps break down the dye and render it nontoxic. Basireddy noted the potential simplicity of a CoffeeBots-based solution to methylene blue pollution, saying, “It's cool because the countries that are big textile producers also happen to be the countries that are big in coffee production.” The team cited Brazil, Colombia, Ethiopia, India, Peru, and Vietnam as countries that produce both dyed textiles and coffee and struggle with water pollution.

Oil and microplastics

The final pollutant tested is perhaps the most exciting, as it’s been a burgeoning topic of concern in recent years: microplastics. In water, microplastics cling to coffee grounds for the same reason that oil does: each substance is hydrophobic.

“One reason why microplastics and nanoplastics are such a tricky environmental problem is that they're so small, and that makes it difficult to locate them just to remove them,” said Moran. “By driving the CoffeeBots through the water, the hydrophobic interactions cause the microplastic particles to build up and accumulate on the surface of the coffee grounds.”

Singh noted that, while other (perhaps more expensive) techniques exist for remediating oil spills and removing chemical pollutants from water, developing a technique to make microplastic removal more efficient is an exciting new development.

Further plans

The team has applied for a patent to protect the technology and are excited to determine the full capabilities of CoffeeBots. They are optimistic because CoffeeBots are potentially a simple, inexpensive solution to water pollution.

While Basireddy has moved on to her freshman year at Johns Hopkins University, Singh and Moran look forward to finding further applications for CoffeeBots and possibly improving their technology. For example, Singh hopes to find a way to make CoffeeBots move when activated by sunlight, which would enable them to propel themselves through the water without the need for an external magnet. In addition, the team plans to explore the full range of pollutants that can be removed by CoffeeBots and characterize the efficacy of different coffee types.

Get a more detailed look at the team's experiments by reading their paper in Nanoscale, “Eliminating waste with waste: transforming spent coffee grounds into microrobots for water treatment,” which includes several videos of CoffeeBots in action, such as the one below. In addition, Singh created a video to promote CoffeeBots on YouTube.

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Jeffrey Moran

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New lab closes the loop on water sustainability

Anonymous — Mon, 06 Dec 2021 18:47:56 +0000

New lab closes the loop on water sustainability Anonymous (not verified) Mon, 12/06/2021 - 13:47

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Kirin Emlet Furst

The water that pours out from your kitchen faucet goes through a lot to make it to your home. Assistant Professor Kirin Emlet Furst wants to use her new high-tech Water Systems Chemistry Lab at the Potomac Science Center to close the loop on water and increase the efficiency of those processes by taking a systems approach.

Kirin Furst (pictured) says that the new equipment in her lab makes their work studying water from different angles possible and accurate. Photo by Evan Cantwell.

Furst, a faculty member in the Sid and Reva Dewberry Department of Civil, Environmental, and Infrastructure Engineering, believes a systems approach is the best way to solve the world’s safe water problems. “Our research lab is primarily focused on removing organic contaminants in drinking water systems and potable reuse systems,” says Furst.

The water treatment process has many steps: source water protection, water treatment, the distribution of the water, and what people are actually exposed to in their homes. “A lot of researchers and research labs focus on one of these processes, but we have projects that touch each part of the water system,” Furst says.

Furst’s main research interest is in reducing disinfection byproducts caused by reactions between dissolved organic materials and water disinfectants. The disinfectants used in water are essential to preventing water-borne pathogens, but when they react with materials that remain in the water, they can create toxins that have numerous health effects.

“To solve the disinfection byproducts problem, we have to look at the bigger picture. It’s hard to test their effects, and there are dozens of opportunities for these toxins to be introduced, so we can’t look at one stage in the process,” she says.

Furst and the graduate and undergraduate students in her lab are also working on ways to increase affordable water treatment methods for low-income areas and increase the treatment and reuse of wastewater. In addition, some of her graduate students are looking into creating new types of filters, others at reducing phthalates.

The advanced equipment in her lab gives her and her students the ability to tackle numerous parts of the water treatment systems, says Furst. And she is looking forward to the new and innovative projects her undergraduate and graduate students will take on.