The methane moment – Cross-boundary significance of methanogens


Book Description

Methane is a potent greenhouse gas, a relatively clean burning fossil fuel, but also a renewable biofuel when biologically produced from waste treatment plants. Most (~70%) of the global methane emission comes from methanogenic archaea, namely methanogens that produce methane from simple substrates such as H2/CO2, formate, acetate, methanol, and other methylated compounds. Methanogens are found across all corners of the earth, including but not limited to wetlands, animals and humans, rice fields, landfills, sewage, ocean, termites, and hydrothermal vents. Their extensive adaptations to such a wide range of habitats predict a cross-boundary significance of methanogens in many areas such as the environment, energy, agriculture, biotechnology, and human and animal health. The goal of this Research Topic is to offer a forum that highlights the cross-boundary significance of methanogens by bringing together methanogen research from diverse settings to one place. This cross-boundary significance is currently underappreciated but imperative to collectively understanding and helping to solve some of the biggest and most urgent challenges humanity is facing such as global warming, food and energy insecurity, pollution, and disease. As a more potent and shorter-lived greenhouse gas than CO2, methane has moved to the center stage in our efforts in rapidly combating climate change. Presumably, methanogens and their associated microbes may have been forced into a positive feedback loop to fuel the sharp rise of methane in recent years. On the other hand, methanogens are considered keystone species in the ecosystem, which are vital to the stability of the natural biome therein. However, the roles of methanogens as keystone species across their habitats are underexplored. Moreover, the role of methanogens in human and animal intestinal microbiomes have been reconsidered with evidence for links to disease and impact on nutrition. Last but not the least, methanogens are emerging as a cell factory model for green manufacturing, because of their abilities to convert CO2 to valuable biochemicals. Further efforts in the bioengineering of methanogens have the potential to expand their commercial application from waste treatment to biomanufacturing. We welcome both basic and translational studies relevant to methanogens from any setting. Studies with a focus on methanogens are highly encouraged, and manuscripts having methanogens as a significant component are also welcome. All studies should emphasize and envisage their implications in understanding and/or solving one or more challenges humanity is facing. To encourage submissions from multiple disciplines, this Research Topic is cross-listed with a number of Frontiers journals and sections. Manuscripts in the forms of Original Research, Review (including systematic and mini review), Methods, Hypothesis and Theory, and Perspectives are all welcome. Manuscript summary submissions are highly encouraged but all manuscripts submitted prior to the manuscript submission deadline will receive full consideration. This Research Topic is dedicated to Dr. William Barny Whitman, Emeritus Professor of Microbiology at the University of Georgia, Athens, GA. His 40+ years (and still counting) of productive research in methanogens, roseobacter, and other prokaryotes have contributed to and will continue to inspire new discoveries in the cross-boundary significance of both archaea and bacteria – the unseen majority. COI Statement: S.K.-M.R.R. is co-founder of Arkeon GmbH. M.P. is a consultant for Bausch Health, Ferring Pharmaceuticals Inc., Salvo Health, and Vivante Health Inc.




Biogeochemistry of Wetlands


Book Description

The globally important nature of wetland ecosystems has led to their increased protection and restoration as well as their use in engineered systems. Underpinning the beneficial functions of wetlands are a unique suite of physical, chemical, and biological processes that regulate elemental cycling in soils and the water column. This book provides an in-depth coverage of these wetland biogeochemical processes related to the cycling of macroelements including carbon, nitrogen, phosphorus, and sulfur, secondary and trace elements, and toxic organic compounds. In this synthesis, the authors combine more than 100 years of experience studying wetlands and biogeochemistry to look inside the black box of elemental transformations in wetland ecosystems. This new edition is updated throughout to include more topics and provide an integrated view of the coupled nature of biogeochemical cycles in wetland systems. The influence of the elemental cycles is discussed at a range of scales in the context of environmental change including climate, sea level rise, and water quality. Frequent examples of key methods and major case studies are also included to help the reader extend the basic theories for application in their own system. Some of the major topics discussed are: Flooded soil and sediment characteristics Aerobic-anaerobic interfaces Redox chemistry in flooded soil and sediment systems Anaerobic microbial metabolism Plant adaptations to reducing conditions Regulators of organic matter decomposition and accretion Major nutrient sources and sinks Greenhouse gas production and emission Elemental flux processes Remediation of contaminated soils and sediments Coupled C-N-P-S processes Consequences of environmental change in wetlands# The book provides the foundation for a basic understanding of key biogeochemical processes and its applications to solve real world problems. It is detailed, but also assists the reader with box inserts, artfully designed diagrams, and summary tables all supported by numerous current references. This book is an excellent resource for senior undergraduates and graduate students studying ecosystem biogeochemistry with a focus in wetlands and aquatic systems.




Methods for Measuring Greenhouse Gas Balances and Evaluating Mitigation Options in Smallholder Agriculture


Book Description

​​This book provides standards and guidelines for quantifying greenhouse gas emissions and removals in smallholder agricultural systems and comparing options for climate change mitigation based on emission reductions and livelihood trade-offs. Globally, agriculture is directly responsible for about 11% of annual greenhouse gas (GHG) emissions and induces an additional 17% through land use change, mostly in developing countries. Farms in the developing countries of sub-Saharan Africa and Asia are predominately managed by smallholders, with 80% of land holdings smaller than ten hectares. However, little to no information exists on greenhouse gas emissions and mitigation potentials in smallholder agriculture. Greenhouse gas measurements in agriculture are expensive, time consuming, and error prone, challenges only exacerbated by the heterogeneity of smallholder systems and landscapes. Concerns over methodological rigor, measurement costs, and the diversity of approaches, coupled with the demand for robust information suggest it is germane for the scientific community to establish standards of measurements for quantifying GHG emissions from smallholder agriculture. Standard guidelines for use by scientists, development organizations will help generate reliable data on emissions baselines and allow rigorous comparisons of mitigation options. The guidelines described in this book, developed by the CGIAR Research Program on Climate Change, Agriculture, and Food Security (CCAFS) and partners, are intended to inform anyone conducting field measurements of agricultural greenhouse gas sources and sinks, especially to develop IPCC Tier 2 emission factors or to compare mitigation options in smallholder systems.




Biomethanization of the Organic Fraction of Municipal Solid Wastes


Book Description

Biomethanization of the Organic Fraction of Municipal Solid Wastes is a comprehensive introduction to both the fundamentals and the more practical aspects of the anaerobic digestion of organic solid wastes, particularly those derived from households, that is, the organic fraction of municipal solid wastes (OFMSW). It can be used as a textbook for specialized courses and also as a guide for practitioners. In the first part, the book covers the relevant aspects of anaerobic digestion (AD) of organic wastes. The fundamentals and kinetic aspects of AD are reviewed with particular emphasis on the aspects related to solid wastes. This introduction is necessary to have a comprehensive view of the AD process and to understand the practical principles as well as the origin of possible problems arising from the management of the process. Chapter 2 emphasizes the role of kinetics in designing the reactor, paying special attention to existing models, particularly the dynamic ones. Through this introduction, it is intended to facilitate the technology transfer from laboratory or pilot plant experiences to full-scale process, in order to implement improvements in current digesters. Laboratory methods are described for the analysis and optimization of reactor performance, such as methanogenic activity tests or experimental evaluation of the biodegradation kinetics of solid organic waste. The different reaction patterns applied to industrial reactors are outlined. Industrial reactors are classified in accordance with the system they use, pointing out advantages and limitations. Co-digestion, enabling the co-treatment of organic wastes of different origin in a more economically feasible way, is described in detail. Examples of co-digestion are given, with OFMSW as a base-substrate. Finally, full-scale co-digestion plants are discussed. Various types (mechanical, biological, physico-chemical) of pre-treatment to increase the biodegradability, and thus the yields of the process, are reviewed in detail. The use of the fermentation products of anaerobic digesters for biological nutrient removal processes in wastewater treatment plants is described. This constitutes an example of integrated waste management, a field in which both economic and technical advances can be achieved. Balances are given to justify the approach, and a full-scale case study is presented. The important topic of economics and the ecological advantages of the process are emphasized. The use of compost, the integration with composting technology, and advantages over other technologies are detailed in the framework of an environmental impact assessment of biowaste treatment. Finally, the anaerobic digestion of MSW in landfills is reviewed in detail, with emphasis on landfill process enhancement and strategies for its application.




Integrated Solid Waste Management: A Lifecycle Inventory


Book Description

Life is often considered to be a journey. The lifecycle of waste can similarly be considered to be a journey from the cradle (when an item becomes valueless and, usually, is placed in the dustbin) to the grave (when value is restored by creating usable material or energy; or the waste is transformed into emissions to water or air, or into inert material placed in a landfill). This preface provides a route map for the journey the reader of this book will undertake. Who? Who are the intended readers of this book? Waste managers (whether in public service or private companies) will find a holistic approach for improving the environmental quality and the economic cost of managing waste. The book contains general principles based on cutting edge experience being developed across Europe. Detailed data and a computer model will enable operations managers to develop data-based improvements to their systems. Producers oj waste will be better able to understand how their actions can influence the operation of environmentally improved waste management systems. Designers oj products and packages will be better able to understand how their design criteria can improve the compatibility of their product or package with developing, environmentally improved waste management systems. Waste data specialists (whether in laboratories, consultancies or environ mental managers of waste facilities) will see how the scope, quantity and quality of their data can be improved to help their colleagues design more effective waste management systems.







Biofilms in Wastewater Treatment


Book Description

The central theme of the book is the flow of information from experimental approaches in biofilm research to simulation and modeling of complex wastewater systems. Probably the greatest challenge in wastewater research lies in using the methods and the results obtained in one scientific discipline to design intelligent experiments in other disciplines, and eventually to improve the knowledge base the practitioner needs to run wastewater treatment plants. The purpose of Biofilms in Wastewater Treatment is to provide engineers with the knowledge needed to apply the new insights gained by researchers. The authors provide an authoritative insight into the function of biofilms on a technical and on a lab-scale, cover some of the exciting new basic microbiological and wastewater engineering research involving molecular biology techniques and microscopy, and discuss recent attempts to predict the development of biofilms. This book is divided into 3 sections: Modeling and Simulation; Architecture, Population Structure and Function; and From Fundamentals to Practical Application, which all start with a scientific question. Individual chapters attempt to answer the question and present different angles of looking at problems. In addition there is an extensive glossary to familiarize the non-expert with unfamiliar terminology used by microbiologists and computational scientists. The colour plate section of this book can be downloaded by clicking here. (PDF Format 1 MB)




Methane and Methanol Utilizers


Book Description

Methane and its oxidation product, methanol, have occupied an important position in the chemical industry for many years: the former as a feedstock, the latter as a primary chemical from which many products are produced. More recently, the role played by methane as a potent "greenhouse" gas has aroused considerable attention from environmentalists and clima tologists alike. This role for C compounds has, of course, been quite 1 incidental to the myriad of microorganisms on this planet that have adapted their life-styles to take advantage of these readily available am bient sources. Methane, a renewable energy source that will always be with us, is actually a difficult molecule to activate; so any microorganism that can effect this may point the way to catalytic chemists looking for con trollable methane oxidation. Methanol, formed as a breakdown product of plant material, is also ubiquitous and has also encouraged the growth of prokaryotes and eukaryotes alike. In an attempt to give a balanced view of how microorganisms have been able to exploit these simple carbon sources, we have asked a number ofleading scientists (modesty forbids our own inclusion here) to contribute chapters on their specialist areas of the subject.




Sewage Treatment Plants


Book Description

Sewage Treatment Plants: Economic Evaluation of Innovative Technologies for Energy Efficiency aims to show how cost saving can be achieved in sewage treatment plants through implementation of novel, energy efficient technologies or modification of the conventional, energy demanding treatment facilities towards the concept of energy streamlining. The book brings together knowledge from Engineering, Economics, Utility Management and Practice and helps to provide a better understanding of the real economic value with methodologies and practices about innovative energy technologies and policies in sewage treatment plants.




Greenhouse Gas Emissions from Ecotechnologies for Wastewater Treatment


Book Description

Ecotechnologies for wastewater treatment (EWWT) have been used as a cost-effective alternative to conventional wastewater treatment methods for improving the removal of organic carbon, nutrients and pathogenic microorganisms from wastewater. However, due to biochemical transformations of organic matter and nutrients EWWT are net sources of CO2, CH4 and N2O greenhouse gases (GHGs), which may be transferred into the atmosphere contributing to global warming. Greenhouse Gas Emissions from Ecotechnologies for Wastewater Treatment provides scientific information about greenhouse gas, such as CO2, CH4 and N2O, generation and emissions from different municipal EWWT. The main EWWT considered in this book are anaerobic ponds, facultative ponds, duckweed-based ponds, and a freshwater natural wetland perturbed by anthropogenic activities such as wastewater discharge and nutrients from agricultural run-off. The book includes a full literature review of recent publications about GHGs emissions from EWWT. It also introduces the calculation of GHGs flux using a static chamber technique. Besides, the book presents information on the influence of environmental factors such as temperature, pH, DO, and nutrients on GHG emissions produced in EWWT under tropical conditions. This book will be a useful reference for researches and students interested in the broader area of water and climate change subjects. The publication may also be of interest to policy makers concerned with climate change, water sector planning, and wastewater treatment.




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