Investigating Community Dynamics and Performance During Microbial Electrochemical Degradation of Whey

Abstract

Abstract Whey is a main by‐product of the dairy industry and is difficult to valorise for small and medium enterprises. Microbial electrochemical technologies could be the key for these enterprises to exploit this current waste product. Whey removal and conversion to electrical current was investigated at microbial anodes using potentiostatically controlled half‐cell experiments. The anodes were fed with a whey solution containing ca. 1 g L −1 COD. This can be reliably cleaned with average removal efficiencies of 65.8±10.9 %. The removal coincided with maximum current densities of 0.31±0.06 mA cm −2 and Coulomb efficiencies of 37.1±10.8 %. The anodes are based on a robust complex microbial community. This was established in bioelectrochemical reactors by end of four batch cycles showing an efficient niche differentiation from the following successive enrichments. The microbial analysis revealed a division of labour with mainly planktonic microorganisms degrading the complex whey components by fermentation to organic acids, part of which are subsequently used by the electroactive bacteria at the anode. The results show the need for deciphering microbial structure‐function relationships for future process steering as well as engineering approaches.

Key findings

• ▸9 %.
• ▸06 mA cm⁻² and Coulomb efficiencies of 37.
• ▸8 %.

Keywords

Identifiers

DOI

10.1002/celc.201902109

Journal

ChemElectroChem

Year

2020