A recent study introduces a novel algae–algae-type microbial fuel cell (AA-MFC) that significantly enhances chemical oxygen demand (COD) removal efficiency while simultaneously generating high-value microalgal biomass.

Under closed-circuit conditions, the AA-MFC achieved over 90% COD removal efficiency and improved biomass yields compared to traditional open-circuit setups.

Interestingly, the study found that lower initial inoculum densities at the anode resulted in higher stable output currents, challenging previous assumptions based solely on biomass.

The microalgae used in the study effectively removed 97% of nitrate, 90% of nitrite, and 90.6% of COD, showcasing their potential in wastewater treatment.

Chlorella vulgaris, in particular, demonstrated a moderate growth rate of 0.137 d⁻¹ while achieving significant pollutant removal, indicating its dual role in wastewater treatment and biofuel production.

Biomass from C. vulgaris was processed to extract fatty acids, yielding a notable 20% extraction rate, further emphasizing its value.

The research highlights the pressing environmental issues caused by dye-laden industrial effluents and underscores the need for effective treatment methods.

In addition to the AA-MFC, the study investigates the decolorization and mineralization of Evans blue dye using an integrated aerobic bioreactor system with a double-chamber microbial fuel cell (DCMFC).

Findings suggest that higher dye concentrations inhibit microbial activity, which may adversely affect decolorization efficiency.

Microbial community analysis revealed a significant presence of Pseudomonadota, with notable genera such as Actinomarinicola and Geobacter, contributing to the system's effectiveness.

Electrochemical impedance spectroscopy (EIS) indicated a well-developed biofilm and efficient electron transfer, with an anode resistance of 12.48 Ω, crucial for the system's performance.

The AA-MFC reactor was designed with a double-chamber configuration, featuring carbon felt electrodes and a proton exchange membrane to facilitate biofilm cultivation.