Biofilm structure, dynamics, and ecology of an upscaled biocathode wastewater microbial fuel cell

Abstract

A microbial fuel cell (MFC) system containing modular half‐submerged biocathode was operated for 6 months in an 800 L flow‐through system with domestic wastewater. For the first time, spatial and temporal differences in biofilm communities were examined on large three‐dimensional electrodes in a wastewater MFC. Biocathode microbial community analysis showed a specialized biofilm community with electrogenic and electrotrophic taxa forming during operation, suggesting potentially opposing electrode reactions. The anodic community structure shifted during operation, but no spatial differences were observed along the length of the electrode. Power output from the system was most strongly influenced by pH. Higher power densities were associated with the use of solids‐dewatering filtrate with increased organic matter, conductivity, and pH. The results show that the biocathode was the rate‐limiting step and that future MFC design should consider the effect of size, shape, and orientation of biocathodes on their community assembly and electrotrophic ability.

Comparative Biosorption Proficiency in Intact and Autoclaved Biofilm Matrices

“…Maintaining the suspension at 25°C through a thermostatic water bath, vigorous mixing was ensured using a magnetic stirrer (approximately 700 rpm). Subsamples of the suspension were extracted at various time intervals (1,3,5,10,20,30,60,90,120, and 180 minutes after the addition of the test) and subsequently centrifuged (10,000×g at 4°C for 1 minute) to obtain the supernatant. The ion concentration in the supernatant was determined using capillary electrophoresis (CAPI-3300; Otsuka Electronics, Osaka, Japan).…”

“…Moving forward, further research endeavors should focus on elucidating the intricate mechanisms governing ion dynamics within biofilms and exploring novel approaches for enhancing their efficacy in environmental remediation [Leininger et al, 2021]. By leveraging the insights gained from this study, future investigations can optimize the design and implementation of biofilm-based systems for water purification, ultimately contributing to developing more efficient and sustainable solutions for addressing water pollution challenges [Philipp et al, 2023].…”

Sorting Out the Latest Advances in Separators and Pilot-Scale Microbial Electrochemical Systems for Wastewater Treatment: Concomitant Development, Practical Application, and Future Perspective

“…A modular design has been proposed to maximize power generation; the "intensive stack" construction was developed to minimize the "size effect" (power density decays with an increase in reactor size), 31,32 and a biotic cathode was applied for increased stability. 33,34 Although the separator is considered an important breakthrough and a shortcut that has attracted a great deal of interest since the research of MFCs, several obstacles, including the high capital cost and unsustainable configurations, still limit their application on an industrial scale. As an indispensable structure, the separator physically separates the anode and cathode in dual-chamber MFCs, while the separator electrode assemblies and sandwich-type assembly configurations are typically found in single-chamber MFCs.…”

“…Researchers worldwide have worked tirelessly to improve their technical and engineering performance. A modular design has been proposed to maximize power generation; the “intensive stack” construction was developed to minimize the “size effect” (power density decays with an increase in reactor size), , and a biotic cathode was applied for increased stability. , Although the separator is considered an important breakthrough and a shortcut that has attracted a great deal of interest since the research of MFCs, several obstacles, including the high capital cost and unsustainable configurations, still limit their application on an industrial scale …”