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.
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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.
