Simultaneous bioelectricity generation and water desalination using Oscillatoria sp. as biocatalyst in photosynthetic microbial desalination cell

Highlights: • In this study, Oscillatoria sp. used as biocatalyst in the cathode for improving the MDC performance. • MDC with biocatalyst achieved higher performance (44.1 ± 1.0 mW/m²) than control (31.1 ± 1.0 mW/m²). • Higher salt concentration significantly affected the power production & desalination efficiency. • Highest COD removal & desalination efficiency was observed as 80.2 ± 0.5 and 65.8 ± 0.5%. • Oscillatoria sp. can be potential catalyst for energy generation and wastewater treatment. Globally, the scarcity of drinking water has triggered the researchers towards the development of desalination techniques to turn up saline water into potable. Microbial Desalination Cell (MDC) is a novel green technology that shows potential approach for desalination along with electricity generation and wastewater treatment. However, the expensive catholyte/catalyst in the cathode side has limited the MDC for real time application. Hence, the main objective of this work was to investigate the electricity generation during dairy wastewater treatment and desalination efficiency using biocathode (Oscillatoria sp.) in the MDC. The results showed that the maximum open circuit voltage of 652 ± 10 mV, COD removal efficiency of 80.2 ± 0.5% and desalination efficiency of 65.8 ± 0.5%, were achieved respectively. The effect of saline water concentration was investigated and the performance of MDC was compared with real (sea) water. This study demonstrated that Oscillatoria sp. could be used as a potential biocatalyst in the cathode chamber for enhancing salinity removal along with electricity generation and wastewater treatment in the MDC.