In Vivo Polymerization (“Hard-Wiring”) of Bioanodes Enables Rapid Start-Up and Order-of-Magnitude Higher Power Density in a Microbial Battery

• Published in: Environmental science & technology Vol. 54; no. 22; pp. 14732 - 14739
• Main Authors: Dubrawski, Kristian L, Woo, Sung-Geun, Chen, Wei, Xie, Xing, Cui, Yi, Criddle, Craig S
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 17.11.2020
• Subjects: Biochemical fuel cells; Bioelectric Energy Sources; Catalysts; Electrochemistry; Electrodes; Energy harvesting; Ferric Compounds; Fuel technology; Microorganisms; Pigments; Platinum; Polymerization; Polymers; Polypyrroles; Pyrroles; State power; Steady state; Treatment and Resource Recovery; Wastewater dilution; Wastewater treatment
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/acs.est.0c05000

For microbial electrochemical technologies to be successful in the decentralized treatment of wastewater, steady-state power density must be improved and cost must be decreased. Here, we demonstrate in vivo polymerization (“hard-wiring”) of a microbial community to a growing layer of conductive polypyrrole on a sponge bioanode of a microbial battery, showing rapid biocatalytic current development (∼10 times higher than a sponge control after 4 h). Moreover, bioanodes with the polymerized inoculant maintain higher steady-state power density (∼2 times greater than the control after 28 days). We then evaluate the same hard-wired bioanodes in both a two-chamber microbial fuel cell and microbial battery with a solid-state NaFeIIFeIII(CN)6 (Prussian Blue) cathode, showing approximately an order-of-magnitude greater volumetric power density with the microbial battery. The result is a rapid start-up, low-cost (no membrane or platinum catalyst), and high volumetric power density system (independent of atmospheric oxygen) for harvesting energy and carbon from dilute organics in wastewater.