Impact of volatile fatty acids on microbial electrolysis cell performance

Nan Yang; Hisham Hafez; George Nakhla

doi:10.1016/j.biortech.2015.06.124

Impact of volatile fatty acids on microbial electrolysis cell performance

Bioresour Technol. 2015 Oct:193:449-55. doi: 10.1016/j.biortech.2015.06.124. Epub 2015 Jun 30.

Authors

Nan Yang¹, Hisham Hafez², George Nakhla³

Affiliations

¹ Department of Civil and Environmental Engineering, University of Western Ontario, London, Ontario N6A 5B9, Canada.
² Department of Civil and Environmental Engineering, University of Western Ontario, London, Ontario N6A 5B9, Canada; GreenField Ethanol Inc., Chatham, Ontario N7M 5J4, Canada.
³ Department of Civil and Environmental Engineering, University of Western Ontario, London, Ontario N6A 5B9, Canada; Department of Chemical and Biochemical Engineering, University of Western Ontario, London, Ontario N6A 5B9, Canada. Electronic address: gnakhla@eng.uwo.ca.

PMID: 26159302
DOI: 10.1016/j.biortech.2015.06.124

Abstract

This study investigated the performance of microbial electrolysis cells (MECs) fed with three common fermentation products: acetate, butyrate, and propionate. Each substrate was fed to the reactor for three consecutive-batch cycles. The results showed high current densities for acetate, but low current densities for butyrate and propionate (maximum values were 6.0 ± 0.28, 2.5 ± 0.06, 1.6 ± 0.14 A/m(2), respectively). Acetate also showed a higher coulombic efficiency of 87 ± 5.7% compared to 72 ± 2.0 and 51 ± 6.4% for butyrate and propionate, respectively. This paper also revealed that acetate could be easily oxidized by anode respiring bacteria in MEC, while butyrate and propionate could not be oxidized to the same degree. The utilization rate of the substrates in MEC followed the order: acetate > butyrate > propionate. The ratio of suspended biomass to attached biomass was approximately 1:4 for all the three substrates.

Keywords: Biomass; Hydrogen; Microbial electrolysis cell; Volatile fatty acids.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Bioelectric Energy Sources / microbiology*
Biological Oxygen Demand Analysis
Biomass
Bioreactors / microbiology
Electricity
Electrodes
Electrolysis / methods*
Fatty Acids, Volatile / pharmacology*
Hydrogen / metabolism
Ion Exchange Resins / chemistry
Thermodynamics

Substances

Fatty Acids, Volatile
Ion Exchange Resins
Hydrogen