Effect of fermentation stillage of food waste on bioelectricity production and microbial community structure in microbial fuel cells

Abstract

A single-chamber microbial fuel cell (MFC) was used in this study to treat recycled stillage obtained from food waste ethanol fermentation. Corresponding substrates inside the system were evaluated by fluorescence spectra, and microbial communities were also investigated. Results demonstrated that output voltage and current, respectively, reached 0.29 V and 1.4 mA with an external resistance of 200 Ω. Corresponding total organic carbon and chemical oxygen demand removal efficiency reached more than 50% and 70%, respectively. Results of fluorescence spectra demonstrated that tryptophan-like aromatic, soluble microbial by-product-like and humic acid-like substances accumulated and were not easily degraded. Microbial community analysis by high-throughput sequence indicated that Advenella and Moheibacter occupied the highest proportion among all genera at the anode instead of Geobacter . These results may be due to complicated accumulated stillage, and potential tetracyclines possibly influenced microbial communities. Details on how stillage affects MFC operation should be further studied, and a solution on relieving effects should be established.

Key findings

• ▸Output voltage and current reached 0.29V and 1.4mA with an external resistance of 200Ω.
• ▸Total organic carbon and chemical oxygen demand removal efficiency reached more than 50% and 70%, respectively.
• ▸Microbial community analysis showed that Advenella and Moheibacter occupied the highest proportion among all genera at the anode, instead of Geobacter.

Keywords

Identifiers

DOI

10.1098/rsos.180457

Journal

Royal Society Open Science

Year

2018