An 18-year-old student from Colorado Springs has developed a sustainable floating device that uses wind-driven wave energy and a local invasive weed to remove toxic algal blooms from freshwater lakes. Natalie Muro, a senior at William J. Palmer High School, tested her prototype in a local reservoir that had been closed to the public because of a severe outbreak of toxic blue-green algae. Her field tests showed that the device removed nearly all of the targeted cyanobacteria while also trapping dead cell material that could otherwise fuel future blooms. The project earned Muro a national finalist position in the 2026 Regeneron Science Talent Search, the oldest and most prestigious high school science and mathematics competition in the United States, run by the Society for Science.
Harnessing waves and invasive weeds
Harmful algal blooms happen when toxin-producing cyanobacteria grow rapidly in warm water containing high levels of agricultural runoff. The resulting algae can threaten drinking water supplies, kill aquatic wildlife and make people and domestic animals sick. Common treatments, such as copper sulfate, can also harm the environment because heavy metals can build up in sediments and affect organisms that are not part of the target bloom. Muro looked for a cleaner approach using a mild 3 percent hydrogen peroxide solution. The chemical breaks down into water and oxygen, leaving no harmful synthetic byproducts. To use the treatment without electric pumps or a power supply, she built a floating buoy with an internal storage pipe. The system uses natural wind-driven waves to move the device and slowly release controlled amounts of hydrogen peroxide into the upper layer of the water. However, killing cyanobacteria creates another problem. As dead microorganisms break down, they release nutrients back into the water. These nutrients can feed new algal blooms. To address this, Muro used Great Mullein (Verbascum thapsus), an invasive plant that grows widely along roadsides in Colorado. She collected the weed and heated it to create biochar, a porous material similar to charcoal. She placed the Great Mullein biochar inside fine mesh bags attached to the buoy. As the hydrogen peroxide killed the cyanobacteria, the porous biochar trapped and held the dead organic material, removing it from the water before it could sink and decompose.
Field testing in a closed reservoir
After improving the design through laboratory tests, Muro took the device into the field. She received permission to test it in a nearby reservoir that had been closed by health officials because of high toxicity levels. According to technical research summaries documented by the Society for Science and the International Science and Engineering Fair (ISEF), laboratory and field tests showed that Muro’s selected dose of hydrogen peroxide reduced target cyanobacteria such as Dolichospermum by 99 percent over 48 hours compared with untreated samples. Water tests also showed that beneficial, non-target aquatic microorganisms were not harmed during the treatment period. At the same time, the Great Mullein biochar mesh captured up to 96 percent of the floating organic material. Together, the two parts of the system reduced bacterial levels while leaving the water cleaner and clearer. In a profile published by Science News Explores, Muro said she was especially excited to move her work from the laboratory into a real lake environment. “I really loved that I got to be able to test [my device] in a reservoir near my house,” Natalie said. “That had been a goal of mine, to actually be able to take my research from the lab into the field.”
From Netflix inspiration to national awards
Muro’s interest in environmental engineering began in an unusual way. Her interest in marine systems and wave mechanics was first inspired by watching Outer Banks, a popular Netflix drama set along the Atlantic coast. After working on wave energy projects during her earlier high school years, one of her teachers encouraged her to apply her interest in water engineering to environmental problems affecting inland Colorado. Building the floating device required months of research and collaboration. Muro contacted academic experts to improve her chemical formulas and engineering plans. “The people,” Natalie said when asked about the most important resources behind her project. “I have cold-emailed so many professors … to ask if they would meet with me on Zoom so I could bounce some ideas off of them.” Her mother, Sarah Muro, also provided important support throughout the testing process. “She was there through the early mornings, the late nights, every success, every failure. And I absolutely could not have done it without her support and her encouragement,” Muro said.Outside her environmental engineering work, Muro is an Eagle Scout, leads her school’s Science Olympiad team and competes in varsity flag football, soccer, tennis and swimming. When asked what advice she would give young scientists interested in science competitions, Muro stressed the importance of taking initiative. “You never know unless you try,” Natalie said. “Taking those leaps and having some bravery to approach people will get you the farthest in your research.” With water treatment facilities around the world spending millions of dollars each year managing seasonal algal blooms, Muro’s low-cost, wave-powered buoy could offer communities a simple and scalable way to restore damaged lakes without adding harmful chemicals to the water.
