Studies have shown that phosphorous is a driving factor in the overproduction of harmful algal blooms (HABs). Researchers have been searching for more effective phosphorous management strategies to protect ecosystems.
Research into Using Algal Biomass for Phosphorus Removal
Florida Atlantic University researchers have looked at how algal biomass, particularly cyanobacteria otherwise known as blue-green algae, can be used to create materials that remove phosphate from water.
They have transformed cyanobacterial biomass, which is typically a hazardous waste, into custom absorbent materials that can pull the harmful phosphorus out of water.
Testing and Results of Algae-Based Absorbent Materials
The researchers collected cyanobacterial biomass from Florida’s Lake Okeechobee and processed it before activation using microwave heating. They also tested absorbent materials modified with lanthanum chloride or zinc chloride. These tests helped the researchers understand how to convert the biomass into chemically modified activated carbon absorbent materials.
The research shows that materials treated with lanthanum chloride removed more than 99% of phosphorus, even at starting phosphorus concentrations as high as 20 milligrams per litre of water.
The best material could be synthesised in three minutes and successfully achieved 90% phosphorus removal efficiency with a low amount of material (0.2 gram per litre of contaminated water) and just 30 minutes of contact time.
Performance in Real-World Conditions and Future Potential
This material also performed well in the presence of natural organic matter by selectively removing phosphorus.
This provides an innovative approach to addressing challenges in water quality management. With more research, the technique could become a tool for managing nutrient pollution and preserving aquatic ecosystems globally.
“Our findings suggest that lanthanum-modified algae-based materials could be an effective solution for removing phosphorus and preventing harmful algal blooms if used on a larger scale,” said Masoud Jahandar Lashaki, senior author, assistant professor and graduate programme director/coordinator in FAU’s Department of Civil, Environmental and Geomatics Engineering. “By using readily available waste materials like algal biomass, combined with lanthanum, an element known for its strong phosphorus-binding capabilities, we have developed an adsorbent that can effectively target and remove excess phosphorus from water. Phosphorus is a major contributor to the occurrence of harmful algal blooms, which can lead to toxic water conditions, loss of aquatic life, and significant economic impacts on industries like fishing and tourism.”
