Microbial electrochemical systems (MESs, also known as bioelectrochemical systems (BESs) are promising technologies for energy and products recovery coupled with wastewater treatment, and have attracted increasing attention. Many studies have been conducted to expand the application of MESs for contaminants degradation and bioremediation, and increase the efficiency of electricity production by optimizing architectural structure of MESs, developing new electrode materials, etc. However, one of the big challenges for researchers to overcome, before MESs can be used commercially, is to improve the performance of the biofilm on electrodes so that ‘electron transfer’ can be enhanced. This would lead to greater production of electricity, energy or other products. Electrochemically active microorganisms (EAMs) are a group of microorganisms which are able to release electrons from inside their cells to an electrode or accept electrons from an electron donor. The way in which EAMs do this is called ‘extracellular electron transfer’ (EET). So far, two EET mechanisms have been identified: direct electron transfer from microorganisms physically attached to an electrode, and indirect electron transfer from microorganisms that are not physically attached to an electrode. 1) Direct electron transfer between microorganisms and electrode can occur in two ways: a) when there is physical contact between outer membrane structures of the microbial cell and the surface of the electrode, b) when electrons are transferred between the microorganism and the electrode through tiny projections (called pili or nanowires) that extend from the outer membrane of the microorganism and attach themselves to the electrode. 2) Indirect transfer of electrons from the microorganisms to an electrode occurs via long-range electron shuttle compounds that may be naturally present (in wastewater, for example), or may be produced by the microorganisms themselves. The electrochemically active biofilm, which degrades contaminants and produces electricity in MESs, consists of diverse community of EAMs and other microorganisms. However, up to date only a few EAMs have been identified, and most studies on EET have focused on the two model species of Shewanella oneidensis and Geobacter sulfurreducens.

Microbial electrochemical systems (MESs, also known as bioelectrochemical systems (BESs) are promising technologies for energy and products recovery coupled with wastewater treatment, and have attracted increasing attention. Many studies have been conducted to expand the application of MESs for contaminants degradation and bioremediation, and increase the efficiency of electricity production by optimizing architectural structure of MESs, developing new electrode materials, etc. However, one of the big challenges for researchers to overcome, before MESs can be used commercially, is to improve the performance of the biofilm on electrodes so that 'electron transfer' can be enhanced. This would lead to greater production of electricity, energy or other products. Electrochemically active microorganisms (EAMs) are a group of microorganisms which are able to release electrons from inside their cells to an electrode or accept electrons from an electron donor. The way in which EAMs do this is called 'extracellular electron transfer' (EET). So far, two EET mechanisms have been identified: direct electron transfer from microorganisms physically attached to an electrode, and indirect electron transfer from microorganisms that are not physically attached to an electrode. 1) Direct electron transfer between microorganisms and electrode can occur in two ways: a) when there is physical contact between outer membrane structures of the microbial cell and the surface of the electrode, b) when electrons are transferred between the microorganism and the electrode through tiny projections (called pili or nanowires) that extend from the outer membrane of the microorganism and attach themselves to the electrode. 2) Indirect transfer of electrons from the microorganisms to an electrode occurs via long-range electron shuttle compounds that may be naturally present (in wastewater, for example), or may be produced by the microorganisms themselves. The electrochemically active biofilm, which degrades contaminants and produces electricity in MESs, consists of diverse community of EAMs and other microorganisms. However, up to date only a few EAMs have been identified, and most studies on EET have focused on the two model species of Shewanella oneidensis and Geobacter sulfurreducens.

This book serves as a manual of research techniques for electrochemically active biofilm research. Using examples from real biofilm research to illustrate the techniques used for electrochemically active biofilms, this book is of most use to researchers and educators studying microbial fuel cell and bioelectrochemical systems. The book emphasizes the theoretical principles of bioelectrochemistry, experimental procedures and tools useful in quantifying electron transfer processes in biofilms, and mathematical modeling of electron transfer in biofilms. It is divided into three sections: Biofilms: Microbiology and microbioelectrochemistry - Focuses on the microbiologic aspect of electrochemically active biofilms and details the key points of biofilm preparation and electrochemical measurement Electrochemical techniques to study electron transfer processes - Focuses on electrochemical characterization and data interpretation, highlighting key factors in the experimental procedures that affect reproducibility Applications - Focuses on applications of electrochemically active biofilms and development of custom tools to study electrochemically active biofilms. Chapters detail how to build the reactors for applications and measure parameters

Electrochemically active bacteria are important biocatalysts in bioelectrochemical systems. This work investigated the long-term behaviour of an electrochemical defined mixed culture of Geobacter sulfurreducens and Shewanella oneidensis, and the influence of the set anode potential on this defined mixed culture. Further, G. sulfurreducens was investigated non-electrochemically in pure culture to elucidate how this bacterium accomplishes oxygen reduction. Planktonic S. oneidensis cells were found to be beneficial for current production and biofilm growth of G. sulfurreducens in a microbial electrolysis cell. However, upon removal of planktonic cells, these benefits could not be maintained as S. oneidensis was not incorporated sufficiently into the G. sulfurreducens-based biofilm. In terms of the applied anode potential, 0.2 VAg/AgCl as well as 0.2 VAg/AgCl were found to be best. At 0.2 VAg/AgCl the highest current density was achieved while at -0.2 VAg/AgCl the highest current production in relation to biofilm thickness was observed. G. sulfurreducens was found to reduce oxygen in non-electrochemical pure cultures at a maximum specific oxygen uptake rate of 95 ± 11 mgO2 gCDW-1 h-1. The expression of the gene for the cytochrome bd menaquinol oxidase was found to be upregulated under microaerobic conditions, indicating this enzyme to be responsible for oxygen reduction.

Scaling Up of Microbial Electrochemical Systems: From Reality to Scalability is the first book of its kind to focus on scaling up of microbial electrochemical systems (MES) and the unique challenges faced when moving towards practical applications using this technology. This book emphasizes an understanding of the current limitations of MES technology and suggests a way forward towards onsite applications of MES for practical use. It includes the basics of MES as well as success stories and case studies of MES in the direction of practical applications. This book will give a new direction to energy researchers, scientists and policymakers working on field applications of microbial electrochemical systems—microbial fuel cells, microbial electrolysis cells, microbial electrosynthesis cells, and more. - Promotes the advancement of microbial electrochemical systems, from lab scale to field applications - Illustrates the challenges of scaling up using successive case studies - Provides the basics of MES technology to help deepen understanding of the subject - Addresses lifecycle analysis of MES technology to allow comparison with other conventional methods

Bioelectrochemical Systems (BESs) are innovative and sustainable devices. They combine biological and electrochemical processes to engineer sensors, treat wastewater and/or produce electricity, fuel or high-value chemicals. In BESs, scientists have managed to incorporate biological catalysts, i.e. enzymes and/or microorganisms, and make them work in advanced electrochemical cells. BESs operate under mild conditions — at close to ambient temperature and pressure and at circumneutral pH — and represent a sustainable alternative to precious metal-based systems. Incorporating biological catalysts into devices while maintaining their activity and achieving electrical communication with electrode surfaces is a critical challenge when trying to advance the field of BESs.From implantable enzymatic biosensors to microbial electrosynthesis, and from laboratory-scale systems and fundamental studies to marketed devices, this book provides a comprehensive overview of recent advances related to functional electrodes for BESs. Suitable for researchers and graduate students of chemistry, biochemistry, materials science and environmental science and technology.

A one-stop guide to the future of sustainable energy production The search for sustainable energy sources powered by renewable, non-fossil fuel resources is one of the great scientific challenges of the era. Microorganisms such as bacteria and algae have been shown to function as the basis of a microbial fuel cell, which can operate independently of an electrical power grid on the basis of renewable feed sources. These fuel cells have shown applications ranging from powering implantable biomedical devices to purifying rural water sources, and many more. Microbial Electrochemical Technologies offers a one-stop shop for researchers and developers of technologies incorporating these microbial fuel cells. Beginning with the fundamental processes involved in microbial energy production and the key components of a bioelectrochemical system (BES), it then surveys the major BES types and crucial aspects of technological development and commercialization. The result is an indispensable introduction to these vital power sources and their myriad applications. Microbial Electrochemical Technologies readers will also find: Detailed treatment of BES types including fuel cells, electrolysis and electrosynthesis cells, and more Discussion of commercialization aspects including modelling, performance analysis, and life cycle assessment An authorial team with decades of combined experience on three continents Microbial Electrochemical Technologies is a useful reference for electrochemists, microbiologists, biotechnologists, and bioengineers.

Artificial or constructed wetlands are an emerging technology particularly for tropical areas with water scarcity. For big cities, the sustainable management of water resources taking into account proper use is always challenging. The book presents case studies illustrating the above. As plants and microorganisms are a fundamental part of the correct functioning of these systems, their contribution to the degradation of the organic matter and to the removal and transformation of the pollutant compounds present in the wastewaters is also a highlight of this book.