The use of microalgae-microbial fuel cells in wastewater bioremediation and bioelectricity generation

Synthetic wastewater bioremediation and bioelectricity production were assessed in a bench-scale microalgaemicrobial fuel cell (MMFC) system. The experiments were conducted in triplicate for 7 days with 3 different combinations: MMFC1 (Escherichia coli + Desmodesmus subspicatus), MMFC2 (Pseudomonas aeruginosa + D. subspicatus), and MMFC3 (E. coli + Pseudokirchneriella subcapitata). The pH range (6-8) was ideal for microbial growth. The MMFC 1 had a higher bioelectricity production than MMFC 2 and MMFC 3, with 560 mV (p < 0.05) on the 7th day of operation. The microalgae showed a high bioremediation efficiency, with a significant reduction (p < 0.05) of the total phosphorous (TP) and total organic carbon (TOC) after 7 days. In conclusion, the MMFC 1 containing E. coli in the anodic chamber and D. subspicatus in the cathodic chamber was most effective in the bioelectricity generation. All the system combinations were promising for the bioremediation, with average nutrient removal efficiencies of 55.5%, 39.2%, and 64.5%, for TP, TN, and TOC, respectively. The studied systems could simultaneously produce bioelectricity and remediate wastewater.