Newswise — Algae blooms make a pond’s surface shine in mesmerizing green hues. But if the microorganisms responsible are cyanobacteria, they can also release toxins that harm humans and wildlife alike. So, a team reporting in ACS ES&T Water has designed a “set it and forget it” system for distributing algaecide using specialized buoys tethered at the site of a bloom. In tests, the buoys removed nearly all cyanobacteria without the need for frequent reapplication.

Algae blooms occur when extra nutrients in the water — likely from fertilizer runoff — cause tiny microorganisms like algae and cyanobacteria to proliferate. In 2014, one such algae bloom in Lake Erie near Toledo, Ohio, rendered drinking water unsafe for hundreds of thousands of residents. And now, a team of researchers from the University of Toledo are looking to create an algaecide treatment system that puts a stop to a bloom before it has even started. The team, including Umberto Kober, Hanieh Barikbin, Youngwoo Seo, Yakov Lapitsky and colleagues, designed a system that releases algaecide steadily over a period of weeks or months, making it less expensive and more efficient than existing options that require frequent reapplication.

The team constructed small, medium, and large-sized buoys out of PVC pipes, forming either a “T” or cross shape. Hydrogel disks were inserted into the pipe openings to control the diffusion of the liquid algaecide into the surrounding water. The buoys were then filled with a commercial hydrogen peroxide-based algaecide, which, upon immersion, slowly diffused through the hydrogel disks. The buoys were also engineered so that once the algaecide was gone, the buoy fell to its side, visually indicating that a refill was needed.

To test their performance, the small, algaecide-loaded buoys were put in a beaker with 1 liter of cyanobacteria-containing water collected from Lake Erie and monitored for two weeks. Every day a small portion of water was replaced with new lake water to ensure the buoys were continually exposed to fresh cyanobacteria. This way, the team could evaluate whether the buoys provided sustained algicidal activity rather than killing the cyanobacteria early in the process. Researchers found that the cyanobacteria were almost entirely eliminated within a week, and other microbes remained largely unscathed. Researchers estimate that their buoys could reliably release algaecide for at least four consecutive release cycles, each lasting 35 days.

Though further research is needed, including enhancements to prevent microbe growth on the buoy’s surface, the researchers say that this work overcomes challenges in sustained and targeted algaecide treatment.

“If successfully scaled up, this concept could enable early mitigation of harmful algal blooms without the need for labor-intensive repeated algaecide applications,” says Lapitsky.

The authors acknowledge funding from the U.S. Army Corps of Engineers. The algaecide used in these experiments was provided by the SePRO Corporation, an algaecide manufacturer.

Authors Yakov Lapitsky, Umberto Kober and Youngwoo Seo have filed a patent application on this research.

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The American Chemical Society (ACS) is a nonprofit organization founded in 1876 and chartered by the U.S. Congress. ACS is committed to improving all lives through the transforming power of chemistry. Its mission is to advance scientific knowledge, empower a global community and champion scientific integrity, and its vision is a world built on science. The Society is a global leader in promoting excellence in science education and providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, e-books and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a leader in scientific information solutions, its CAS division partners with global innovators to accelerate breakthroughs by curating, connecting and analyzing the world’s scientific knowledge. ACS’ main offices are in Washington, D.C., and Columbus, Ohio.

Registered journalists can subscribe to the ACS journalist news portal on EurekAlert! to access embargoed and public science press releases. For media inquiries, contact newsroom@acs.org.

Note: ACS does not conduct research but publishes and publicizes peer-reviewed scientific studies.

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Newswise — ATLANTA, March 22, 2026 — Hawaii has a plastic problem. The island state faces economic and logistical challenges in recycling plastic waste, including marine debris that lingers in its ocean waters. Researchers in Hawaii are pioneering a method to recycle the islands’ derelict fishing nets and residential plastic trash into asphalt roads. Early demonstrations show that these recycled materials may provide a viable end-of-life fate for the region’s garbage.

Jeremy Axworthy, a researcher at the Center for Marine Debris Research (CMDR) at Hawaiʻi Pacific University, will present the team’s results at the spring meeting of the American Chemical Society (ACS). ACS Spring 2026 is being held March 22-26; it features nearly 11,000 presentations on a range of science topics.

“This work investigates whether it’s responsible to use recycled plastics in Hawaii’s roads,” shares Axworthy. “By reusing plastic waste that is already in Hawaii, we can reduce the environmental and economic impacts of transporting waste plastics from the islands, incinerating it or dumping it in Hawaii’s overflowing landfills.”

Since 2020, Hawaii’s roads have predominantly been paved with polymer-modified asphalt (PMA) to increase pavement strength and durability. Compared to standard asphalt pavement, PMA pavement is more elastic and more resistant to cracking, rutting and water damage — qualities that are especially important for the state’s tropical climate. PMA pavement is made by first melting pellets of styrene-butadiene-styrene (SBS; a type of copolymer) into a sticky, petroleum-based asphalt binder. Then, the PMA binder is tumbled with heated aggregates (rocks and sand) in a mixing drum, causing the PMA binder to fully coat the aggregates.

But why not see if discarded plastics could be incorporated into asphalt pavements as an environmentally friendly disposal option? How would modified pavements made with recycled plastics perform, and would they release microplastics or associated chemicals into the environment? These are the questions the Hawaii Department of Transportation (HDOT) aimed to answer when they reached out to environmental chemist Jennifer Lynch, CMDR director and team lead.

HDOT asked Lynch’s team for two things. The first was to provide derelict fishing nets removed from Hawaii’s marine environment for the creation of recycled plastic-modified asphalt pavements. “Foreign plastic derelict fishing gear is the largest contributor of Hawaii’s marine debris problem,” shares Lynch. “To date, CMDR’s Bounty Project, which pays a financial reward to licensed commercial fishers for marine debris removal, has removed 84 tons of large, derelict fishing gear from the Pacific Ocean.”

HDOT’s second request was to measure possible microplastic shedding from pavements made with plastic waste versus that from standard SBS-modified pavement. “CMDR’s laboratory is equipped with state-of-the-art chemical instrumentation for quantifying and characterizing microplastics in environmental samples,” explains Lynch. “This capability is incredibly unique and impactful, especially when coupled to our marine debris-removal project and our mission to recycle the debris into long-term, locally necessary infrastructure products.”

Once a U.S.-based company converted the waste into products that could be incorporated into asphalt, HDOT took the experimental asphalt mixes to Hawaii’s streets. A local paving company laid down sections of a residential road on the island of Oahu with asphalt pavement containing standard SBS, repurposed polyethylene from Honolulu’s recycling containers and polyethylene from fishing nets. After about 11 months of regular traffic usage, Lynch’s team stepped in to collect road dust samples from each section of pavement to test for microplastic shedding, which could contaminate the surrounding soil.

The researchers processed the road dust using a method that separates different types of polymers from other materials in the dust, including microplastics, larger chunks of plastic and tire rubber. Using pyrolysis gas chromatography-mass spectrometry (Py-GC-MS), they identified and measured the source of the polymers: styrene and butadiene from the standard PMA, polyethylene from the plastic-waste and fishing-net PMA, and isoprene and butadiene rubber from tires.

Initial tests showed that pavements made with recycled polyethylene did not release more polymers than the control pavement made with SBS. Lynch’s team showed this was true during mechanical performance tests with pavement samples as well as in simulated stormwater collected from the experimental road sections. Microplastic-sized particles were detected, but very few of these were identified as polyethylene regardless of the pavement type tested. This is likely because the polymers are melted into the asphalt binder, meaning particles that break off are not plastic alone; they are a mixture of rock, binder and melted polymer chains.

The CMDR team is also comparing the amount of polymers shed from the pavement to the amount of polymers shed by tires in the road dust. “In our initial Py-GC-MS data,” continues Lynch, “we saw tire wear swamps the signal of polyethylene by orders of magnitude, like gigantic peaks! We had to search the weeds of the chromatogram to find signs of polyethylene.”

Additional research is needed to assess pavement durability. But the researchers are hopeful that someday, repurposing used plastics into pavement could help reduce landfill and marine debris in Hawaii.

“Some people think plastic recycling is a hoax — that it doesn’t work; it’s too challenging,” Lynch shares. “But this work demonstrates that recycling can work when society prioritizes sustainability.”

The research was funded by the Hawaii Department of Transportation.

Visit the ACS Spring 2026 program to learn more about this presentation, “Harvesting ocean plastics to pave hawaiian roads: Evaluation of microplastic and plastic additive release from asphalt incorporating recycled plastic from various waste streams,” and other science presentations.

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The American Chemical Society (ACS) is a nonprofit organization founded in 1876 and chartered by the U.S. Congress. ACS is committed to improving all lives through the transforming power of chemistry. Its mission is to advance scientific knowledge, empower a global community and champion scientific integrity, and its vision is a world built on science. The Society is a global leader in promoting excellence in science education and providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, e-books and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a leader in scientific information solutions, its CAS Division partners with global innovators to accelerate breakthroughs by curating, connecting and analyzing the world’s scientific knowledge. ACS’ main offices are in Washington, D.C., and Columbus, Ohio. 

To automatically receive press releases from the American Chemical Society, contact newsroom@acs.org. 

Note to journalists: Please report that this research was presented at a meeting of the American Chemical Society. ACS does not conduct research, but publishes and publicizes peer-reviewed scientific studies.

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Title
Harvesting ocean plastics to pave hawaiian roads: Evaluation of microplastic and plastic additive release from asphalt incorporating recycled plastic from various waste streams

Abstract
Polymer modified asphalt (PMA) is used to increase strength and durability of roads. In Hawaii, PMA is typically produced using the virgin co-polymer styrene-butadiene-styrene (SBS). Recycled plastics, such as high-density polyethylene (HDPE), may also be added to asphalt serving to sequester plastic waste. In the state of Hawaii, derelict fishing gear (DFG) is a significant problem, yet it is also a source of HDPE that can be used in recycling. However, asphalt performance and the consequences of adding recycled polymers to asphalt are not well understood. In collaboration with the Hawaii Department of Transportation (HDOT) and the University of Hawaii (UH), the Center for Marine Debris Research (CMDR) are testing the feasibility of using recycled HDPE in asphalt by quantifying microplastics and plastic additives release from roads paved with asphalts made from different combinations of virgin and recycled polymers. The specific asphalt combinations being tested are: SBS (Control-PMA), DFG with and without SBS (DFG-PMA and DFG-neat), Local Waste recycled HDPE with and without SBS (LW-PMA and LW-neat), and Commercially Available, post-industrial recycled HDPE with and without SBS (CA-PMA and CA-neat). Microplastic and plastic additive release under laboratory conditions were performed using a Hamburg Wheel Tracker Test (HWTT) with water sample analyses. Field trials were conducted on a residential road on the island of Oahu, Hawaii. Road dust was swept and analyzed for microplastics by direct analysis and solvent extraction to separate bound plastic from asphalt and plastic additives by water extraction. Microplastic samples utilized pyrolysis gas chromatography mass spectrometry for analysis. Plastic additives are subjected to solid phase extraction with analysis by gas chromatography mass spectrometry. Results produced using these novel analytical methods provide guidance on the use of recycled plastics over virgin plastics in roadways. Moreover, results of this study may provide a viable end of life fate for plastic marine debris, leading to cleaner and healthier oceans.

Newswise — After high-profile water crises like the one in Flint, Michigan, some Americans distrust the safety of tap water, choosing to purchase drinking water from freestanding water vending machines or kiosks. Yet this more expensive water may contain different pollutants than local tap water, according to a study in ACS’ Environmental Science & Technology. Researchers report that water sampled from 20 kiosks in six states sometimes contained lead at levels above public health recommendations.

“Currently, water kiosks are not regulated the same as tap water; their water is not tested for lead or other metals,” says Samantha Zuhlke, a corresponding author of this study. “Updating water kiosk regulations can improve their quality and help consumers make informed decisions about the water they are drinking.”

Water kiosks are privately owned vending machines that are often marketed as being safer than tap water, commanding prices of $0.25-$0.35 per gallon (compared to less than 2 cents per gallon for tap water in most U.S. cities). Kiosk operators generally treat local tap water with purification techniques such as filtration, ultraviolet light or reverse osmosis (RO) to remove potentially harmful contaminants such as lead, microbes, residual disinfectants, and per- and polyfluoroalkyl substances (PFAS). But water vending machines in the U.S. are poorly regulated. So, a team of researchers led by Zuhlke and David Cwiertny conducted a comprehensive comparison of the chemical and microbial characteristics of kiosk water and tap water from municipalities close to the monitored kiosks.

The team collected water samples from 20 kiosks operated by four different manufacturers across Iowa and in the surrounding states of Illinois, Kansas, Missouri, Arkansas and Oklahoma. Most of the kiosks advertised treatment of their water by RO, a process that uses pressure to force water through a semipermeable membrane, purifying the water and leaving most contaminants caught behind the membrane. For comparison, the researchers collected tap water samples from community sources within a mile of each kiosk.

They analyzed all samples and found no evidence of microbial contamination in any sample. They also found that RO treatment in kiosks effectively removed most PFAS from the sourced tap water. However, this benefit was offset by concerning levels of lead in some RO-purified kiosk water samples — nearly twice the concentration recommended by the U.S. Environmental Protection Agency.

The researchers traced the lead to the corrosion of brass plumbing in the kiosks following RO treatment. Although the plumbing components are marketed as “lead-free,” small amounts of the metal can leach under the low-pH and low-alkalinity conditions of RO-treated water, they say. Replacing the internal metal pieces with other materials could eliminate lead in dispensed water.

“This work adds to growing evidence that allowable levels of lead in ‘lead-free’ plumbing can still be problematic sources of lead in drinking water when such plumbing is exposed to certain types of water, like that generated after RO treatment,” Cwiertny says.

The authors acknowledge funding from the University of Iowa’s Center for Social Science Innovation and the Office of Undergraduate Research. This work was conducted through the University of Iowa Center for Health Effects of Environmental Contamination, which receives support through the Iowa Department of Natural Resources.

The paper’s abstract will be available on Feb. 11 at 8 a.m. Eastern time here:   

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The American Chemical Society (ACS) is a nonprofit organization founded in 1876 and chartered by the U.S. Congress. ACS is committed to improving all lives through the transforming power of chemistry. Its mission is to advance scientific knowledge, empower a global community and champion scientific integrity, and its vision is a world built on science. The Society is a global leader in promoting excellence in science education and providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, e-books and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a leader in scientific information solutions, its CAS division partners with global innovators to accelerate breakthroughs by curating, connecting and analyzing the world’s scientific knowledge. ACS’ main offices are in Washington, D.C., and Columbus, Ohio.

Registered journalists can subscribe to the ACS journalist news portal on EurekAlert! to access embargoed and public science press releases. For media inquiries, contact newsroom@acs.org.

Note: ACS does not conduct research but publishes and publicizes peer-reviewed scientific studies.

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