Application Driven Fundamental Research on Microbial Electrochemical Technologies: From Components to System

Microbial electrochemistry is the study and application of interactions between microbial cells and electron conductors (electrodes). For a long time this field of bioelectrochemistry has been the interest of only fundamental researchers. This has significantly changed during the last decade, in which microbial electrochemistry gained increasing interest from applied researchers and engineers. Among other types of potential application, these researchers developed microbial fuel cells (MFCs), microbial electrolysis cells (MECs) and microbial desalination cells (MDCs) – electrochemical systems that utilize the organic load in wastewater to produce electric power, to produce chemical compounds or to desalinate salt water, respectively. However, the great majority of research on full systems is still being performed at laboratory scale (less than 1 L reactor volume) and technical or even pilot scale studies are rare. Rationally the majority of current studies do not focus on the system scale, but on the advancement of components, e.g. electrodes and membranes, and the investigation of fundamental processes of these components, e.g. interactions in microbiomes formed at electrodes, aiming at their subsequent engineering. However, system scale studies have clearly revealed a substantially higher degree of complexity and thus achievements on the component scale often cannot be simply transferred.

Therefore, we advocate that the most important issue is wisely merging fundamental research at the component scale with full system development. In this presentation we will illustrate on selected, recent examples the rationale of our appeal, spanning from very fundamental aspects like the development of high-performance electrode materials via the removal of micropollutants from wastewater at laboratory scale to a recent technical scale demonstrator and its performance in cleaning municipal wastewater and nitrogen recovery.