Development of a stable Nannochloropsis gaditana L2 microalgae-bacteria consortium for wastewater treatment and its initial application in microbial fuel cells

This study investigates the effect of Nannochloropsis gaditana L2 inoculation on wastewater treatment efficiency and the formation of a stable microalgae-bacteria consortium. The results demonstrated that within 1 month of operation in sequencing batch reactors (SBRs), steady-state conditions were achieved, with total Kjeldahl nitrogen (TKN) and chemical oxygen demand (COD) removal rates exceeding 75% and 56%, respectively. Additionally, phosphorus removal, primarily driven by microalgae rather than bacteria, reached 50% after 40 days. The study highlights the crucial role of operational conditions, such as hydraulic retention time (HRT), in optimizing pollutant removal through microalgae-bacteria interactions. Furthermore, preliminary experiments assessed the potential of integrating the developed microalgae-bacteria consortium into a microbial fuel cell (MFC) system for wastewater treatment and electricity generation. While the voltage output remained low, the findings suggest that microalgae could enhance oxygen availability in the biocathode, improving bioelectrochemical performance. Overall, this study demonstrates the feasibility of using Nannochloropsis gaditana L2 in wastewater treatment and provides insights into its potential application in sustainable bioenergy production.