Treatment of Cyanobacterial Harmful Algal Blooms (cHABs) Using Microbial Fuel Cells

Cyanobacterial harmful algal blooms (cHABs), driven by toxin-producing cyanobacteria, are increasingly prevalent due to climate change factors, such as rising water temperatures and nutrient pollution. A major concern associated with cHABs is the production of cyanotoxins like microcystins, with microcystin-LR (MC-LR) being among the most toxic and widespread, produced primarily by Microcystis aeruginosa. Microbial fuel cells (MFCs) have emerged as a promising method for the on-site treatment of freshwater contaminated by cHABs. MFCs employ electrochemically active bacteria (EABs) to convert organic matter into electricity, leveraging microbial communities found in environments like soils, sediments, and aquatic systems. These bacteria perform anaerobic oxidation of organic matter, transferring electrons to an electrode in a closed circuit. Given the nutritional content of cyanobacterial biomass, specifically Microcystis aeruginosa, it serves as an effective substrate for EABs, supporting both energy production and water treatment in MFC systems. However, MC-LR secretion by M. aeruginosa can inhibit critical microbial processes, diminishing MFC efficiency in both electricity generation and bioremediation. Recent advancements have incorporated biodegradable co-substrates to boost EAB growth and enhance MC-LR degradation within MFCs. This research investigates the interactions between Microcystis aeruginosa and EABs within MFCs, specifically targeting strains and cyanobacteria found in Central Park Lake. The study evaluates the potential of MFCs to effectively treat organic matter and degrade MC-LR, aiming to enhance bioremediation strategies for cHAB-contaminated waters.