Natural and Engineered Clay Barriers


Book Description

Clays are used as barriers for the isolation of landfills and contaminated sites. They are envisioned as long-term storage media for hazardous materials and radioactive wastes, and as seals in the case of geological CO2 sequestration or energy storage. Clay properties greatly influence the integrity, efficiency, and safety of these applications. Natural and Engineered Clay Barriers provides a clear view of the fundamental properties of clay materials and how these properties affect their engineering applications. This volume focuses on how the mass transfer properties (hydraulic permeability, gas fluxes, molecular diffusion, semi-permeable membrane properties), geochemical reactivity (adsorption, dissolution) and mechanical properties of clay barriers at the macroscale are influenced by phenomena that occur at clay mineral - water interfaces. - Examines clay properties from the molecular to the macroscopic scale - Addresses experimental and modeling issues - Authored by experts in the properties of clay barriers




Advances in Understanding Engineered Clay Barriers


Book Description

The use of clay barriers for waste-isolating purposes has gained increasing attention in the geotechnical engineering community. Practical interest is linked to fundamental research, which includes examination of the behaviour of compacted materials and expansive clays. The interaction between the barrier, waste and the surrounding ground may involve several thermo-hydro-mechanical and chemical-coupled processes that have been analyzed by means of 'in situ' tests, laboratory experiments and numerical modelling. Large-scale field tests have been developed in recent years by European Agencies dealing with the management of radioactive waste. These experiments have provided an opportunity to calibrate and to validate research models and offer benefits in terms of experience of instrumentation and installation techniques. The book includes about sixty papers presented in a symposium held in Spain in 2003. The four main topics of the book are: field emplacement and instrumentation techniques; fundamental research, material behaviour (i.e. bentonite), and laboratory testing; barrier behaviour and THM modelling; and chemical effects, HC and THMC modelling.




Clays in Natural and Engineered Barriers for Radioactive Waste Confinement


Book Description

This Special Publication contains 43 scientific studies presented at the 5th conference on ‘Clays in natural and engineered barriers for radioactive waste confinement’ held in Montpellier, France in 2012. The conference and this resulting volume cover all the aspects of clay characterization and behaviour considered at various temporal and spatial scales relevant to the confinement of radionuclides in clay, from basic phenomenological process descriptions to the global understanding of performance and safety at repository and geological scales. Special emphasis has been given to the modelling of processes occurring at the mineralogical level within the clay barriers. The papers in this Special Publication consider research into argillaceous media under the following topic areas: large-scale geological characterization; clay-based concept/large-scale experiments; hydrodynamical modelling; geochemistry; geomechanics; mass transfer/gas transfer; mass transfer mechanisms. The collection of different topics presented in this Special Publication demonstrates the diversity of geological repository research.




Assessment of the Performance of Engineered Waste Containment Barriers


Book Description

President Carter's 1980 declaration of a state of emergency at Love Canal, New York, recognized that residents' health had been affected by nearby chemical waste sites. The Resource Conservation and Recovery Act, enacted in 1976, ushered in a new era of waste management disposal designed to protect the public from harm. It required that modern waste containment systems use "engineered" barriers designed to isolate hazardous and toxic wastes and prevent them from seeping into the environment. These containment systems are now employed at thousands of waste sites around the United States, and their effectiveness must be continually monitored. Assessment of the Performance of Engineered Waste Containment Barriers assesses the performance of waste containment barriers to date. Existing data suggest that waste containment systems with liners and covers, when constructed and maintained in accordance with current regulations, are performing well thus far. However, they have not been in existence long enough to assess long-term (postclosure) performance, which may extend for hundreds of years. The book makes recommendations on how to improve future assessments and increase confidence in predictions of barrier system performance which will be of interest to policy makers, environmental interest groups, industrial waste producers, and industrial waste management industry.




Handbook of Clay Science


Book Description

The first edition of the Handbook of Clay Science published in 2006 assembled the scattered literature on the varied and diverse aspects that make up the discipline of clay science. The topics covered range from the fundamental structures (including textures) and properties of clays and clay minerals, through their environmental, health and industrial applications, to their analysis and characterization by modern instrumental techniques. Also included are the clay-microbe interaction, layered double hydroxides, zeolites, cement hydrates, and genesis of clay minerals as well as the history and teaching of clay science. The 2e adds new information from the intervening 6 years and adds some important subjects to make this the most comprehensive and wide-ranging coverage of clay science in one source in the English language. - Provides up-to-date, comprehensive information in a single source - Covers applications of clays, as well as the instrumental analytical techniques - Provides a truly multidisciplinary approach to clay science




Natural and Enhanced Attenuation of Contaminants in Soils, Second Edition


Book Description

Natural attenuation has become an effective and low-cost alternative to more expensive engineered remediation. This new edition updates the principles and fundamentals of natural attenuation of contaminants with a broader view of the field. It includes new methods for evaluating natural attenuation mechanisms and microbial activity at the lab and field scales. Case studies, actual treatments and protocols, theoretical processes, case studies, numerical models, and legal aspects in the natural attenuation of organic and inorganic contaminants are examined. Challenges and future directions for the implementation of natural attenuation and enhanced remediation techniques are also considered.




Containment of High-Level Radioactive and Hazardous Solid Wastes with Clay Barriers


Book Description

One of the principal objections to or problems with the use of nuclear fuel is that a proven method for safe disposal of spent nuclear fuel has yet to be established. The central focus of most schemes underway to dispose of these high-level radioactive wastes relies on clay-based buffers and barriers to isolate spent fuel canisters in borehole




Fundamentals of Geoenvironmental Engineering


Book Description

Fundamentals of Geoenvironmental Engineering: Understanding Soil, Water, and Pollutant Interaction and Transport examines soil-water-pollutant interaction, including physico-chemical processes that occur when soil is exposed to various contaminants. Soil characteristics relevant to remedial techniques are explored, providing foundations for the correct process selection. Built upon the authors' extensive experience in research and practice, the book updates and expands the content to include current processes and pollutants. The book discusses propagation of soil pollution and soil characteristics relevant to remedial techniques. Practicing geotechnical and environmental engineers can apply the theory and case studies in the book directly to current projects. The book first discusses the stages of economic development and their connections to the sustainability of the environment. Subsequent chapters cover waste and its management, soil systems, soil-water and soil-pollutant interactions, subsurface transport of pollutants, role of groundwater, nano-, micro- and biologic pollutants, soil characteristics that impact pollution diffusion, and potential remediation processes like mechanical, electric, magnetic, hydraulic and dielectric permittivity of soils. - Presents a clear understanding of the propagation of pollutants in soils - Identifies the physico-chemical processes in soils - Covers emerging pollutants (nano-, micro- and biologic contaminants) - Features in-depth coverage of hydraulic, electrical, magnetic and dielectric permittivity characteristics of soils and their impact on remedial technologies




Natural Attenuation of Contaminants in Soils


Book Description

Natural attenuation has become widely recognized as an effective and low-cost alternative to more expensive engineered remediation. However, there are uncertainties about natural attenuation√s long-term effects and risks to the environment. There is a particular need to develop a high level of understanding of the natural attenuation proces




Reactive Transport Modeling


Book Description

Teaches the application of Reactive Transport Modeling (RTM) for subsurface systems in order to expedite the understanding of the behavior of complex geological systems This book lays out the basic principles and approaches of Reactive Transport Modeling (RTM) for surface and subsurface environments, presenting specific workflows and applications. The techniques discussed are being increasingly commonly used in a wide range of research fields, and the information provided covers fundamental theory, practical issues in running reactive transport models, and how to apply techniques in specific areas. The need for RTM in engineered facilities, such as nuclear waste repositories or CO2 storage sites, is ever increasing, because the prediction of the future evolution of these systems has become a legal obligation. With increasing recognition of the power of these approaches, and their widening adoption, comes responsibility to ensure appropriate application of available tools. This book aims to provide the requisite understanding of key aspects of RTM, and in doing so help identify and thus avoid potential pitfalls. Reactive Transport Modeling covers: the application of RTM for CO2 sequestration and geothermal energy development; reservoir quality prediction; modeling diagenesis; modeling geochemical processes in oil & gas production; modeling gas hydrate production; reactive transport in fractured and porous media; reactive transport studies for nuclear waste disposal; reactive flow modeling in hydrothermal systems; and modeling biogeochemical processes. Key features include: A comprehensive reference for scientists and practitioners entering the area of reactive transport modeling (RTM) Presented by internationally known experts in the field Covers fundamental theory, practical issues in running reactive transport models, and hands-on examples for applying techniques in specific areas Teaches readers to appreciate the power of RTM and to stimulate usage and application Reactive Transport Modeling is written for graduate students and researchers in academia, government laboratories, and industry who are interested in applying reactive transport modeling to the topic of their research. The book will also appeal to geochemists, hydrogeologists, geophysicists, earth scientists, environmental engineers, and environmental chemists.