Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 Feb 7;13(3):582-589.
doi: 10.1002/cssc.201902923. Epub 2019 Dec 20.

The Limits of Three-Dimensionality: Systematic Assessment of Effective Anode Macrostructure Dimensions for Mixed-Culture Electroactive Biofilms

Affiliations
Free PMC article

The Limits of Three-Dimensionality: Systematic Assessment of Effective Anode Macrostructure Dimensions for Mixed-Culture Electroactive Biofilms

Christopher Moß et al. ChemSusChem. .
Free PMC article

Abstract

This study analyzes the biofilm growth and long-term current production of mixed-culture, electrochemically active biofilms (EABs) on macrostructured electrodes under low-shear-force conditions. The channel dimensions were altered systematically in the range 400 μm to 2 mm, and the channel heights were varied between 1 and 4 mm to simulate macrostructures of different scales. Electrodes with finer-structured surfaces produced higher current densities in the short term owing to their large surface area but were outperformed in the long term because the accumulation of biomass led to limitations of mass transfer into the structures. The best long-term performance was observed for electrodes with channel dimensions of 1×4 mm, which showed no significant decrease in performance in the long term. Channels with a diameter of 400 μm were overgrown by the biofilm, which led to a transition from 3 D to 2 D behavior, indicating that structures of this scale might not be suitable for long-term operation under low-shear-stress conditions.

Keywords: Geobacter; bioelectrochemical systems; confocal microscopy; electrochemistry; macrostructures.

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Average of relative maximum current densities for the control electrodes of all reactors over time (depicted as batch feeding cycles).
Figure 2
Figure 2
Photographic images showing bacterial growth behavior on a structured electrode with 0.8×1 mm channels: a) young biofilm (cycle 2 or ≈2 weeks), b) biofilm during maturation (cycle 4 or ≈3 weeks), c) mature biofilm (cycle 6 or ≈4–5 weeks), d) biofilm detachment (cycle 7–9 or ≈30–50 days).
Figure 3
Figure 3
CLSM 3 D images of biofilms growing across a) 0.6 mm, b) 0.8 mm, c) 1 mm, and d) 2 mm channels; the scales are denoted by color bars (axial) and white scale bars (lateral).
Figure 4
Figure 4
Unfolded maximum current densities for experiments 1–3 (see the Supporting Information for details) relative to the respective control electrodes over time (depicted as batch feeding cycles).
Figure 5
Figure 5
Projected maximum current densities for experiments 1–3 relative to the respective control electrodes plotted against the relative surface area gain provided by the electrode structure. The development of the relative current density of the individual electrode types during the consecutive batch cycles is illustrated by increasing color saturation. The solid line depicts conditions not impacted by mass‐transport limitations, whereas current densities along the dashed line are mass‐transfer limited.
Figure 6
Figure 6
Photographic images showing bacterial growth behavior on differently structured electrodes: a) 1×1 mm, cycle 2; b) 0.4×4 mm, cycle 2; c) 1×1 mm, cycle 7; d) 0.4×4 mm, cycle 7.
Figure 7
Figure 7
Chronoamperometry curves of experiment 4 (see the Supporting Information for details): a) reactor 1, b) reactor 2; maximum current densities for experiment 4: c) reactor 1, d) reactor 2.

Similar articles

See all similar articles

References

    1. Schröder U., Harnisch F., Angenent L. T., Energy Environ. Sci. 2015, 8, 513–519.
    1. Rozendal R. A., Hamelers H. V. M., Rabaey K., Keller J., Buisman C. J. N., Trends Biotechnol. 2008, 26, 450–459. - PubMed
    1. Logan B. E., Regan J. M., Environ. Sci. Technol. 2006, 40, 5172–5180. - PubMed
    1. Liu H., Ramnarayanan R., Logan B. E., Environ. Sci. Technol. 2004, 38, 2281–2285. - PubMed
    1. Logan B. E., Hamelers B., Rozendal R., Schröder U., Keller J., Freguia S., Aelterman P., Verstraete W., Rabaey K., Environ. Sci. Technol. 2006, 40, 5181–5192. - PubMed

LinkOut - more resources

Feedback