A microbial desalination process with microalgae biocathode using sodium bicarbonate as an inorganic carbon source

This research investigates a novel platform for an energy-yielding wastewater treatment and desalination scheme in which the organic matter present in wastewater is purposely fed to the exoelectrogenic bacteria to produce bioelectricity in a three-compartment bioelectrochemical system called photosynthetic microbial desalination cell (PMDC). The role of an inorganic carbon source in the microalgae biocathode was studied. Addition of sodium bicarbonate (NaHCO3) increased power production, microalgae growth and desalination rate. A power density of 660 mW/m3 was measured which is about 7.5 times higher than the PMDCs without NaHCO3. Desalination rate was more than 40% after 72 h. Overall, the process could be energy-positive while producing 4.21 kWh per m3 of wastewater treated including desalination energy savings and microalgae biomass energy potential.