Recently, there’s been a growing interest in finding useful ways to repurpose troublesome algal biomass, which could be turned into valuable products like bioplastics, biofertilizers, and biofuels. Researchers have already explored using algal biomass to create materials that can help clean up things such as heavy metals, rare earth metals, dyes, and even capture CO2 and harmful volatile organic compounds from the air.
However, few studies have looked into how algal biomass, especially cyanobacteria, also known as blue-green algae, can be used to create materials that remove phosphate from water.
Now, researchers from the College of Engineering and Computer Science at Florida Atlantic University, have filled that gap by transforming cyanobacterial biomass, which is typically a hazardous waste, into custom-made adsorbent materials that can pull harmful phosphorus out of water. Adsorbent materials are substances that can attract and hold molecules or particles such as gases, liquids, or dissolved solids on their surface. Unlike absorbent materials that soak up substances into their structure, adsorbents capture molecules on the outside surface, forming a thin layer.
To convert algal biomass into chemically modified activated carbon adsorbent materials for phosphate removal, researchers collected cyanobacterial biomass from Florida’s Lake Okeechobee and processed before activation using fast and energy-efficient microwave heating. To improve phosphate removal from water, researchers tested adsorbent materials modified with lanthanum chloride or zinc chloride. Relatively abundant, lanthanum is a metal that is part of the rare-earth element group. Both compounds are useful in a variety of fields including environmental cleanup, industrial processing, and chemical manufacturing. Previous research did not identify any human health risks associated with the use of lanthanum for phosphorus removal.
Results of the study, published in the journal Algal Research, show that materials treated with lanthanum chloride removed more than 99% of phosphorus, even at starting phosphorus concentrations as high as 20 milligrams per liter of water. The best material could be synthesized in three minutes and successfully achieved 90% phosphorus removal efficiency with a low amount of material (0.2 gram per liter of contaminated water) and just 30 minutes of contact time. This material also performed well in the presence of natural organic matter by selectively removing phosphorus.
The study suggests that lanthanum-modified algae-based adsorbents could help reduce HABs by removing phosphorus from water. The effectiveness comes from the formation of a compound, LaPO4.H2O (also known as rhabdophane), which traps phosphorus permanently.
“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, Ph.D., senior author, assistant professor and graduate program 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.”
Results of this study show the promise of this innovative approach in addressing one of the most pressing challenges in water quality management. With further refinement and scalability, this technique could become an essential tool for managing nutrient pollution and preserving aquatic ecosystems globally.
“Our team’s research highlights the high efficiency of these materials in removing phosphorus over a wide range of concentrations. This approach could provide an environmentally friendly and cost-effective solution to mitigate the effects of eutrophication – the process where excessive nutrients, particularly phosphorus, fuel the growth of harmful algae in lakes, rivers, and coastal areas,” said Stella Batalama, Ph.D., dean, FAU College of Engineering and Computer Science. “By applying lanthanum-modified algae-based materials in regions prone to harmful algal blooms, communities could significantly reduce the occurrence of these blooms, improving water quality, protecting ecosystems, and ensuring safe water for both human use and wildlife.”
Study co-authors are Vithulan Suthakaran, a civil engineer and doctoral candidate in FAU’s College of Engineering and Computer Science; Ryan Thomas, an environmental engineer and FAU graduate; Mitchell Guirard, an environmental engineer and FAU graduate; and Daniel Meeroff, Ph.D., professor and dean of undergraduate studies, FAU Department of Civil, Environmental and Geomatics Engineering.
This research and publication were developed under Project INV12 and funded by the Florida Department of Environmental Protection (FDEP) under the direction of the Blue-Green Algae Task Force. The research team recently received a Phase-II grant ($590,527; INV45) from the FDEP to investigate the scalability of the proposed solution.
- FAU -
About FAU’s College of Engineering and Computer Science:
The FAU College of Engineering and Computer Science is internationally recognized for cutting-edge research and education in the areas of computer science and artificial intelligence (AI), computer engineering, electrical engineering, biomedical engineering, civil, environmental and geomatics engineering, mechanical engineering, and ocean engineering. Research conducted by the faculty and their teams expose students to technology innovations that push the current state-of-the art of the disciplines. The College research efforts are supported by the National Science Foundation (NSF), the National Institutes of Health (NIH), the Department of Defense (DOD), the Department of Transportation (DOT), the Department of Education (DOEd), the State of Florida, and industry. The FAU College of Engineering and Computer Science offers degrees with a modern twist that bear specializations in areas of national priority such as AI, cybersecurity, internet-of-things, transportation and supply chain management, and data science. New degree programs include Master of Science in AI (first in Florida), Master of Science and Bachelor in Data Science and Analytics, and the new Professional Master of Science and Ph.D. in computer science for working professionals. For more information about the College, please visit eng.fau.edu.
About Florida Atlantic University:
Florida Atlantic University, established in 1961, officially opened its doors in 1964 as the fifth public university in Florida. Today, the University serves more than 30,000 undergraduate and graduate students across six campuses located along the southeast Florida coast. In recent years, the University has doubled its research expenditures and outpaced its peers in student achievement rates. Through the coexistence of access and excellence, FAU embodies an innovative model where traditional achievement gaps vanish. FAU is designated a Hispanic-serving institution, ranked as a top public university by U.S. News & World Report and a High Research Activity institution by the Carnegie Foundation for the Advancement of Teaching. For more information, visit www.fau.edu.
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