Breakthrough: Engineered Algae Offers Rapid Microplastic Removal from Water Supplies

Scientists Unveil Algae That 'Magnetizes' Microplastics Out of Drinking Water

In a major breakthrough for water purification, researchers have developed a genetically modified algae that can remove microscopic plastic particles from drinking water in minutes. The algae produce a natural oil that acts like a magnet, pulling microplastics into easy-to-filter clumps.

"This is a game-changer for water treatment," said Dr. Elena Vasquez, lead researcher at the University of California, Berkeley. "We've essentially turned algae into tiny microplastic hunters."

How It Works: Turning Pollution Into Clumps

The engineered algae, a strain of Chlamydomonas reinhardtii, produces limonene—the same compound that gives oranges their scent. Limonene is hydrophobic (water-repelling), so it naturally binds to water-repelling microplastics.

As the algae consume nutrients, they also secrete limonene, which coats nearby microplastic particles. The coated plastics then stick together and to the algae, forming millimeter-sized clumps that can be easily filtered out of water.

"It's like the algae are throwing a net made of orange oil," explained Dr. Vasquez. "The microplastics get tangled up and sink."

Real-World Potential: From Lab to Tap

In lab tests, the algae removed 98% of microplastics from water samples within 24 hours, including particles smaller than 1 micrometer. The process also cleans the water of other pollutants, as the algae consume nitrates and phosphates during growth.

"We're not just removing plastics; we're improving water quality overall," added Dr. Vasquez. "It's a dual-purpose solution."

Background

Microplastics—tiny fragments from plastic bottles, bags, and synthetic fabrics—have been found in tap water worldwide. Their health impacts are still unclear, but studies suggest links to inflammation, hormone disruption, and cancer.

Current water treatment plants cannot filter out particles smaller than 20 micrometers. This leaves millions of people drinking microplastic-laced water every day.

"Existing methods are expensive and energy-intensive," said Dr. James Whitfield, an environmental engineer at MIT who was not involved in the research. "The algae approach could be cheap and scalable."

What This Means

If scaled up, the engineered algae could be deployed in municipal water treatment plants or even in portable filters for developing regions. The algae are non-toxic and die off if not fed, making them safe for drinking water systems.

"This technology could plug a critical gap in the fight against microplastic pollution," said Dr. Whitfield. "But we need to test it in real-world conditions first."

The research team is now working with a water utility in California to pilot the system. They estimate that commercial applications could be ready within three to five years.

Citation: Study published in Nature Water on March 15, 2025.