
Harmful algal blooms (HABs) are spreading worldwide, creating toxic water conditions, killing aquatic life, and harming industries like fishing and tourism.
These blooms are fueled by excessive nutrients in water, especially phosphorus, making it essential to find better ways to manage this key pollutant.
Researchers at Florida Atlantic University (FAU) have discovered an innovative method to tackle this problem by turning harmful algae into a powerful tool for cleaning water.
Their study, published in Algal Research, shows how algae-based materials can remove phosphorus from water, potentially reducing HABs and protecting ecosystems.
The team used cyanobacteria, or blue-green algae, collected from Florida’s Lake Okeechobee—a major source of HABs.
This algae, typically considered hazardous waste, was transformed into adsorbent materials.
Adsorbents attract and hold molecules like phosphorus on their surface, unlike absorbents, which soak substances into their structure.
To create these adsorbents, the algae were processed using fast microwave heating and then chemically modified with either lanthanum chloride or zinc chloride.
Lanthanum, a rare-earth element, is particularly effective at binding phosphorus, and research shows it poses no risks to human health when used for this purpose.
The lanthanum-modified materials proved highly effective. They removed over 99% of phosphorus from water, even at high concentrations (up to 20 milligrams per liter).
The best-performing material required just 0.2 grams per liter of contaminated water and only 30 minutes of contact time to achieve 90% phosphorus removal efficiency. It also worked well in water containing natural organic matter, selectively targeting phosphorus.
The key to this success lies in the formation of a stable compound called LaPO₄·H₂O (rhabdophane), which permanently traps phosphorus, preventing it from contributing to HABs.
“This algae-based technology could be a game-changer in managing nutrient pollution,” said Dr. Masoud Jahandar Lashaki, the study’s senior author. “By repurposing waste materials like algal biomass and combining them with lanthanum, we’ve developed a highly efficient adsorbent to remove phosphorus—a major driver of harmful algal blooms.”
The researchers believe this technique could be scaled up to help communities around the world. Regions prone to HABs could use these materials to improve water quality, protect aquatic life, and ensure safe water for human use.
Eutrophication, the process where excess nutrients fuel algae growth, is a major challenge for water quality worldwide. HABs caused by eutrophication lead to environmental damage and economic losses in industries like tourism and fishing.
“This approach is not only effective but also environmentally friendly and cost-efficient,” said Dr. Stella Batalama, dean of FAU’s College of Engineering and Computer Science. “Using lanthanum-modified algae-based materials could significantly reduce harmful algal blooms, preserving aquatic ecosystems and ensuring cleaner water for future generations.”
With further refinement, this algae-based technology has the potential to become an essential tool in global efforts to combat nutrient pollution and protect water resources.
Source: Florida Atlantic University.