From Extracellular Electron Transfer to Biotechnological Application
Author: Korneel Rabaey
Publisher: IWA Publishing
In the context of wastewater treatment, Bioelectrochemical Systems (BESs) have gained considerable interest in the past few years, and several BES processes are on the brink of application to this area. This book, written by a large number of world experts in the different sub-topics, describes the different aspects and processes relevant to their development. Bioelectrochemical Systems (BESs) use micro-organisms to catalyze an oxidation and/or reduction reaction at an anodic and cathodic electrode respectively. Briefly, at an anode oxidation of organic and inorganic electron donors can occur. Prime examples of such electron donors are waste organics and sulfides. At the cathode, an electron acceptor such as oxygen or nitrate can be reduced. The anode and the cathode are connected through an electrical circuit. If electrical power is harvested from this circuit, the system is called a Microbial Fuel Cell; if electrical power is invested, the system is called a Microbial Electrolysis Cell. The overall framework of bio-energy and bio-fuels is discussed. A number of chapters discuss the basics - microbiology, microbial ecology, electrochemistry, technology and materials development. The book continues by highlighting the plurality of processes based on BES technology already in existence, going from wastewater based reactors to sediment based bio-batteries. The integration of BESs into existing water or process lines is discussed. Finally, an outlook is provided of how BES will fit within the emerging biorefinery area.
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
This volume presents the fundamentals and advances in state-of-the-art catalytic nanoscale interventions to improve the efficiency of bioelectrochemical systems. These systems are used in a number of applications in the water-energy nexus. Contributed chapters describe and build on useful strategies to use and reference when dealing with an important environmental issue: the final disposal of heavy metal catalysts. Summarizing basic and translational research, these chapters are valuable for researchers in energy, nanotechnology, and catalysis.
An introduction to the fundamental concepts and rules in bioelectrochemistry and explores latest advancements in the field Bioelectrochemical Interface Engineering offers a guide to this burgeoning interdisciplinary field. The authors—noted experts on the topic—present a detailed explanation of the field’s basic concepts, provide a fundamental understanding of the principle of electrocatalysis, electrochemical activity of the electroactive microorganisms, and mechanisms of electron transfer at electrode-electrolyte interfaces. They also explore the design and development of bioelectrochemical systems. The authors review recent advances in the field including: the development of new bioelectrochemical configurations, new electrode materials, electrode functionalization strategies, and extremophilic electroactive microorganisms. These current developments hold the promise of powering the systems in remote locations such as deep sea and extra-terrestrial space as well as powering implantable energy devices and controlled drug delivery. This important book: • Explores the fundamental concepts and rules in bioelectrochemistry and details the latest advancements • Presents principles of electrocatalysis, electroactive microorganisms, types and mechanisms of electron transfer at electrode-electrolyte interfaces, electron transfer kinetics in bioelectrocatalysis, and more • Covers microbial electrochemical systems and discusses bioelectrosynthesis and biosensors, and bioelectrochemical wastewater treatment • Reviews microbial biosensor, microfluidic and lab-on-chip devices, flexible electronics, and paper and stretchable electrodes Written for researchers, technicians, and students in chemistry, biology, energy and environmental science, Bioelectrochemical Interface Engineering provides a strong foundation to this advanced field by presenting the core concepts, basic principles, and newest advances.
A Bioelectrochemical System that Converts Waste to Watts
Author: Debabrata Das
Category: Technology & Engineering
This book represents a novel attempt to describe microbial fuel cells (MFCs) as a renewable energy source derived from organic wastes. Bioelectricity is usually produced through MFCs in oxygen-deficient environments, where a series of microorganisms convert the complex wastes into electrons via liquefaction through a cascade of enzymes in a bioelectrochemical process. The book provides a detailed description of MFC technologies and their applications, along with the theories underlying the electron transfer mechanisms, the biochemistry and the microbiology involved, and the material characteristics of the anode, cathode and separator. It is intended for a broad audience, mainly undergraduates, postgraduates, energy researchers, scientists working in industry and at research organizations, energy specialists, policymakers, and anyone else interested in the latest developments concerning MFCs.
Bioelectrochemical systems (BESs) are capable of converting the chemical energy of organic matter using electrochemically-active microorganisms as a catalyst into electrical energy, hydrogen or other value-added products through oxidation/reduction reactions. The findings reported here addressed several different limitations and solutions of BESs operation and performance for wastewater treatment. The first part of the dissertation was focused on the scaling up of anodic biofilms for higher the current generation. We tested the effect of the electrode size and electron donor concentrations, represented as Chemical Oxygen Demand (COD), by enriching anodic biofilms on multiple electrode sizes and quantifying the anodic current densities while changing the electron donor concentrations. It was found that current generated using anodic biofilms was linearly scaled up at high COD loading (1500 mg/L), while current density decreased with increasing electrode size at lower COD loadings (150 mg/L). Further, microbial community analysis showed that the microbial community on the anode was independent of the electrode size but dependent on the medium composition during the enrichment phase. The second part of the dissertation was focused on developing a flow through 3-electrode bioelectrochemical reactor to evaluate how increased surface area could affect COD and total nitrogen (TN) removal rates and studying the mechanisms of nitrogen removal. It was found that increased surface area did not significantly increase COD removal rate. Compared to COD removal rate, TN removal rate increased proportionally to the surface area of the electrode in the BESs. Unexpectedly, outlet nitrite (NO2--N) and nitrate (NO3--N) concentrations increased. Our results indicated that it is possible to anaerobically remove COD while removing TN. Some future works such as integrated BESs with conventional systems to increase nitrogen removal efficiency, cost-benefit analysis, and life cycle analysis have been suggested. Overall, it was concluded that BESs with appropriately designed conditions such as electrode material, electrode size, and electron donor concentrations can be used for current generation and wastewater treatment.
Bioelectrochemical systems (BES) encompass a group of technologies derived from conventional electrochemical systems in which the electrodic reactions are directly or indirectly linked to the metabolic activity of certain types of microorganisms. Although BES have not yet made the leap to the commercial scale, these technologies hold a great potential, as they allow to valorize different liquid and gas waste streams. This chapter is devoted to exploring some of the possibilities that BES offer in the management and valorization of wastes. More specifically, it focuses on analyzing practical aspects of using BES for energy valorization of wastewaters and CO2-rich streams. Here, it is shown how BES can compete, in terms of energy usage, with conventional wastewater treatment technologies by exploiting the energy content of some of the chemicals present in the wastewater. Moreover, it explores how BES could enable using wastewater treatment plants as load regulation system for electrical grids. It also includes some insights on the capability of BES to recover valuable products such as fertilizers form wastes, a feature that allows this technology to promote energy efficiency in the fertilizers industry, and a sector that demands substantial amounts of energy in our world today. Finally, some of the most relevant scale-up experiences in the field are also covered.
The objective of this work was the improvement and control of wastewater treatment using constructed wetlands operated as Microbial Fuel Cells (CW-MFCs) and Microbial Electrolysis Cells (CW-MECs). For this purpose, eight meso-scale experimental systems were constructed. The first experiment investigated the use of CW-MFC as a bioindicator, showing that it could be used as a qualitative alarm tool for sudden COD increases. The following three experiments investigated the removal of conventional contaminants as well as organic micropollutants (OMPs) using duplicates of CW-MEC, closed-circuit CW-MFC, open-circuit CW-MFC and conventional CW-control. Results showed that CW-MEC and CW-MFC+ increased the removal of COD (7-13%) and ammonium (18-22%) when compared to the control systems. Regarding OMPs, carbamazepine, diclofenac and naproxen removal was increased by 10-17% in CW-MFC+ and CW-MEC when compared to the control, while ibuprofen removal was similar amongst treatments. Additionally, a microbial activity analysis showed that activity was 4-34% higher in CW-MFC+ as compared to CW-control, and a microbial community analysis indicated that anode and cathode communities in CW-MEC were significantly different tq other treatments, seemingly due to the effects of electrolysis. In CW-MFC+ only cathode communities were different. probably due to sampling issues at the anodes.
Bioremediation and Nutrients and Other Valuable Products Recovery: Using Bio-electrochemical Systems reviews key applications in transforming fuel waste substrates into simple low impact and easily assimilative compounds that are environmentally non-labile and tolerant. The book emphasizes waste treatment and nutrient removal and recovery from a diverse array of waste substrates, utilizing Bioelectrochemical Systems (BES) approaches. Throughout, the work emphasizes the utilization of electrode and/or electrolyte components in building self-sustaining fuel cell systems that target the removal of both conventional and emerging pollutants, along with the production of energy. Bioremediation strategies with potential scale-up options for wastewater treatment, metal removal and soil remediation drug derivates and emerging contaminants are discussed with particular emphasis. Chapters explore applications for these varied pollutants, together with prospects in waste minimization, nutrient recycling, water purification and bioremediation of natural resources. Explores a detailed panorama of potential known pollutants with detailed reviews on their removal and recovery Discusses bioproduct recovery application frontiers across wastewater treatment and bioremediation, metal removal and soil remediation, extraction of drug derivates and emerging contaminants Emphasizes pilot scale-up and commercialization potential for each recovery application discussed
An Integrated Approach to Commercializing Bioelectrochemical Systems
Author: Lakhveer Singh
Delivering Low-Carbon Biofuels with Bioproduct Recovery: An Integrated Approach to Commercializing Bioelectrochemical Systems explores current pathways to produce both the bioenergy from bioelectroactive fuel cells (BEFC) and their valuable byproducts using bioelectrochemical systems (BES) approaches. The book focuses on key methods, current designs and established variants of biofuels processing approaches, also including case studies. Chapters review crucial aspects of bioreactor design methodologies, operating principles, bioreactor susceptibility and systems constraints. The book supports vulnerability and hotspot detection through simulation and modeling approaches. Concluding chapters establish drivers for realizable scale-up and commercialization of bioelectrochemical systems. Discusses all major commercially viable biofuels, along with their high-value byproducts Focuses on frontiers of low carbon biofuel technologies with commercialization and scale-up potential Supported by schematics that outline integration with bioelectrochemical systems (BES) approaches
Graphical abstract: Highlights: Interfacial charge resistance is not a critical measure for efficient ARB start-up cultivation. Although iron is crucial to biota, conductive and semi-conductive iron particles limit the ARB performance. Iron attract biota with high specific growth rates at strat-up but retard the electron shuttling at interface. CaS-doped graphite is a promising anode material for highly efficient BESs. Abstract: In order to increase the efficiency of microbial fuel cells and related bioelectrochemical systems (BESs), one of the common approaches is to lower the resistance of the anode surface to increase the extracellular electron transfer (EET) of anode respiring bacteria (ARB). As our work demonstrates here, this approach is not ideal when dealing with common species of ARB. Bacteria colonized an electrode surface modified with graphite material doped with nonconductive calcium sulfide (CaS) more favorably than the conductive magnetite (Fe3 O4 ) or semiconductive iron (II) sulfide (FeS). Average anodic current densities of 8.2 ± 0.25 Am −2 (Fe3 O4 ), 10.7 ± 0.46 Am −2 (FeS) and 21.3 ± 1.12 Am −2 (CaS) were achieved as compared to that of non-doped activated carbon (5.04 ± 0.12 A m −2 ). Bioelectrochemical evaluation during growth using simple low-scan (1 mV s −1 ) cycle voltammetry (LSCV) indicated variations in patterns which reflect the variability of the ARBs growth. On the other hand, despite the high affinity of bacteria to grow at a faster rate on Fe3 O4 -anode and CaS-anode, as indicated by the maximum specific growth rate during the start-up exponential phase, the kinetic scan rate study of derivative cycle voltammetry (DCVs) during growth indicated accumulation of bacteria-produced mediators on iron containing anodes which reduced their electrochemical activity. Thus, irrespective of surface resistance, the CaS doped graphite represented a promising anode material which is suitable for highly efficient BES.
Current wastewater treatment technologies are not sustainable simply due to their high operational costs and process inefficiency. Integrated Microbial Fuel Cells for Wastewater Treatment is intended for professionals who are searching for an innovative method to improve the efficiencies of wastewater treatment processes by exploiting the potential of Microbial Fuel Cells (MFCs) technology. The book is broadly divided into four sections. It begins with an overview of the "state of the art" bioelectrochemical systems (BESs) as well as the fundamentals of MFC technology and its potential to enhance wastewater treatment efficiencies and reduce electricity generation cost. In section two, discusses the integration, installation, and optimization of MFC into conventional wastewater treatment processes such as activated sludge process, lagoons, constructed wetlands, and membrane bioreactors. Section three outlines integrations of MFCs into other wastewater processes. The final section provides explorative studies of MFC integrated systems for large scale wastewater treatment and the challenges which are inherent in the upscaling process. Clearly describes the latest techniques for integrating MFC into traditional wastewater treatment processes such as activated sludge process, lagoons, constructed wetlands, and membrane bioreactors Discusses the fundamentals of bioelectrochemical systems for degrading the contaminants from the municipal and industrial wastewater Covers methods for the optimization of integrated systems
Integration of Anaerobic Digestion and Bioelectrochemical Systems for Enhanced Energy Recovery from Wastewater Solids and Other Waste Substrates
Author: Jeff Ryan Beegle
Organic waste streams, like domestic wastewater and municipal solid waste, have the potential to be used as feedstocks for biotechnology processes to produce high value products and energy. This thesis investigated the technological, economical, and environmental potential for integrated anaerobic digestion (AD) and bioelectrochemical system (BES) platforms as they were theoretically and physically evaluated for energy recovery from domestic wastewater. The first chapter of this thesis compared the theoretical energy efficiencies of converting waste directly into electricity, using AD and BES alone and in various combinations. This chapter reviewed the experimentally demonstrated energy efficiencies reported in the literature with comparisons to the maximum theoretical efficiencies, considering thermodynamic limits. Acetate was used as an ideal substrate for theoretical calculations, whereas complex wastes were used for extended analyses of practical efficiencies. In addition, to address the potential economic and environmental benefits of this technology, a brief case study was investigated using the Oak Ridge National Laboratory (ORNL) water resource recovery facility (WRRF). This work identified a combined Anaerobic Digestion/Microbial Electrolysis Cell (ADMEC) platform as the most viable treatment process for further study. In the second chapter, the abovementioned ADMEC system was tested using real domestic wastewater from the ORNL WRRF. The system was modified to include two pretreatment methods, alkaline and thermal hydrolysis, to observe potential effects of pretreatment on energy recovery. The systems in chapter two were operated so that hydrogen recovery was maximized, at the expense of biogas recovery. The results from this chapter indicated that thermal hydrolysis pretreatment had the greatest positive effect on methane composition and hydrogen production, while also reducing overall biogas production. Alkaline pretreatment had a net-negative impact on energy recovery compared to the control. This thesis concludes with my personal reflection on these technologies and where I think they may play a role in the future.