Inhibitory Effect of Furanic and Phenolic Compounds on Exoelectrogenesis in a Microbial Electrolysis Cell Bioanode
- Georgia Inst. of Technology, Atlanta, GA (United States)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)
Furanic and phenolic compounds are 20 lignocellulose-derived compounds known to inhibit to H2- and ethanol- producing microorganisms in dark fermentation. Bioelectrochemical conversion of furanic and phenolic compounds to electricity or H2 has recently been demonstrated as a productive method to use these compounds. However, potential inhibitory effect of furanic and phenolic compounds on exoelectrogenesis in bioelectrochemical systems is not well understood. This study systematically investigated the inhibitory effect of furfural (FF), 5-hydroxymethylfurfural (HMF), syringic acid (SA), vanillic acid (VA), and 4-hydroxybenzoic acid (HBA) on exoelectrogenesis in the bioanode of a microbial electrolysis cell. A mixture of these five compounds at an increasing initial total concentration from 0.8 to 8.0 g/L resulted in current decrease up to 91%. The observed inhibition primarily affected exoelectrogenesis, instead of non-exoelectrogenic biotransformation pathways (e.g., fermentation) of the five compounds. Furthermore, the parent compounds at a high concentration, as opposed to their biotransformation products, were responsible for the observed inhibition. Tests with individual compounds show that all five parent compounds contributed to the observed inhibition by the mixture. The IC50 (concentration resulting in 50% current decrease) was estimated as 2.7 g/L for FF, 3.0 g/L for HMF, 1.9 g/L for SA, 2.1 g/L for VA and 2.0 g/L for HBA. Nevertheless, these compounds below their non-inhibitory concentrations jointly resulted in significant inhibition as a mixture. Catechol and phenol, which were persistent biotransformation products of the mixture, inhibited exoelectrogens at high concentrations, but to a lesser extent than the parent compounds. Recovery of exoelectrogenesis from inhibition by all compounds was observed, except for catechol, which resulted in irreversible inhibition. The reversibility of inhibition, as well as the observed difference in recovery rates, suggest different modes of exoelectrogenesis inhibition, related to the hydrophobicity of the inhibiting compounds.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE)
- Grant/Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1324097
- Journal Information:
- Environmental Science and Technology, Journal Name: Environmental Science and Technology; ISSN 0013-936X
- Publisher:
- American Chemical Society (ACS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Processes and electron flow in a microbial electrolysis cell bioanode fed with furanic and phenolic compounds
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journal | March 2018 |
Characterization and utilization of aqueous products from hydrothermal conversion of biomass for bio-oil and hydro-char production: a review
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journal | January 2019 |
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