Chitosan beads as a bioanode for simultaneous recovery of nutrients and energy from municipal wastewater using a microbial nutrient recovery cell

The transformation of a microbial fuel cell to a microbial nutrient recovery cell has gained attention worldwide since it offers a potential simultaneous solution to the challenges of nutrient and energy recovery from waste streams. Herein, we reported for the first time the use of chitosan beads as a novel eco-friendly anodic material to accommodate electrochemically active bacteria for the efficient recovery of nutrients and the production of energy from wastewater without any external supply of electricity. The developed chitosan bioanode was systematically researched and compared with an activated carbon anode for its potential in terms of nutrient removal and recovery, chemical oxygen demand removal, and energy production from municipal wastewater. The maximum power density estimated for the chitosan-based system (∼600 mW/m²) was found to be as efficient as the activated carbon-based system (∼650 mW/m²). Overall, this study demonstrates a facile/schematic self-driven route for the recovery and enrichment of nutrients (phosphorus recovery of ∼65% and ammonium recovery of ∼64%) from municipal wastewater along with stable voltage production during the whole procedure.