This book focuses on the mechanistic (microscopic) understanding of radionuclide uptake by plants in contaminated soils and potential use of phytoremediation. The key features concern radionuclide toxicity in plants, how the radioactive materials are absorbed by plants, and how the plants cope with the toxic responses. The respective chapters examine soil classification, natural plant selection, speciation of actinides, kinetic modeling, and case studies on cesium uptake after radiation accidents. Radionuclide contaminants pose serious problems for biological systems, due to their chemical toxicity and radiological effects. The processes by which radionuclides can be incorporated into vegetation can either originate from activity interception by external plant surfaces (either directly from the atmosphere or from resuspended material), or through uptake of radionuclides via the root system. Subsequent transfer of toxic elements to the human food chain is a concrete danger. Therefore, the molecular mechanisms and genetic basis of transport into and within plants needs to be understood for two reasons: The effectiveness of radionuclide uptake into crop plants – so-called transfer coefficient – is a prerequisite for the calculation of dose due to the food path. On the other hand, efficient radionuclide transfer into plants can be made use of for decontamination of land – so-called phytoremediation, the direct use of living, green plants for in situ removal of pollutants from the environment or to reduce their concentrations to harmless levels.

This book provides extensive and comprehensive information to researchers and academicians who are interested in radionuclide contamination, its sources and environmental impact. It is also useful for graduate and undergraduate students specializing in radioactive-waste disposal and its impact on natural as well as manmade environments. A number of sites are affected by large legacies of waste from the mining and processing of radioactive minerals. Over recent decades, several hundred radioactive isotopes (radioisotopes) of natural elements have been produced artificially, including 90Sr, 137Cs and 131I. Several other anthropogenic radioactive elements have also been produced in large quantities, for example technetium, neptunium, plutonium and americium, although plutonium does occur naturally in trace amounts in uranium ores. The deposition of radionuclides on vegetation and soil, as well as the uptake from polluted aquifers (root uptake or irrigation) are the initial point for their transfer into the terrestrial environment and into food chains. There are two principal deposition processes for the removal of pollutants from the atmosphere: dry deposition is the direct transfer through absorption of gases and particles by natural surfaces, such as vegetation, whereas showery or wet deposition is the transport of a substance from the atmosphere to the ground by snow, hail or rain. Once deposited on any vegetation, radionuclides are removed from plants by the airstre am and rain, either through percolation or by cuticular scratch. The increase in biomass during plant growth does not cause a loss of activity, but it does lead to a decrease in activity concentration due to effective dilution. There is also systemic transport (translocation) of radionuclides within the plant subsequent to foliar uptake, leading the transfer of chemical components to other parts of the plant that have not been contaminated directly.

Bioremediation refers to the clean‐up of pollution in soil, groundwater, surface water, and air using typically microbiological processes. It uses naturally occurring bacteria and fungi or plants to degrade, transform or detoxify hazardous substances to human health or the environment. For bioremediation to be effective, microorganisms must enzymatically attack the pollutants and convert them to harmless products. As bioremediation can be effective only where environmental conditions permit microbial growth and action, its application often involves the management of ecological factors to allow microbial growth and degradation to continue at a faster rate. Like other technologies, bioremediation has its limitations. Some contaminants, such as chlorinated organic or high aromatic hydrocarbons, are resistant to microbial attack. They are degraded either gradually or not at all, hence, it is not easy to envisage the rates of clean-up for bioremediation implementation. Bioremediation represents a field of great expansion due to the important development of new technologies. Among them, several decades on metagenomics expansion has led to the detection of autochthonous microbiota that plays a key role during transformation. Transcriptomic guides us to know the expression of key genes and proteomics allow the characterization of proteins that conduct specific reactions. In this book we show specific technologies applied in bioremediation of main interest for research in the field, with special attention on fungi, which have been poorly studied microorganisms. Finally, new approaches in the field, such as CRISPR-CAS9, are also discussed. Lastly, it introduces management strategies, such as bioremediation application for managing affected environment and bioremediation approaches. Examples of successful bioremediation applications are illustrated in radionuclide entrapment and retardation, soil stabilization and remediation of polycyclic aromatic hydrocarbons, phenols, plastics or fluorinated compounds. Other emerging bioremediation methods include electro bioremediation, microbe-availed phytoremediation, genetic recombinant technologies in enhancing plants in accumulation of inorganic metals, and metalloids as well as degradation of organic pollutants, protein-metabolic engineering to increase bioremediation efficiency, including nanotechnology applications are also discussed.

Proceedings of a Conference held in Knoxville, Tennessee, April 14-17 1996

The soil is being contaminated continuously by a large number of pollutants. Among them, heavy metals are an exclusive group of toxicants because they are stable and difficult to disseminate into non-toxic forms. The ever-increasing concentrations of such pollutants in the soil are considered serious threats toward everyone's health and the environment. Many techniques are used to clean, eliminate, obliterate or sequester these hazardous pollutants from the soil. However, these techniques can be costly, labor intensive, and often disquieting. Phytoremediation is a simple, cost effective, environmental friendly and fast-emerging new technology for eliminating toxic heavy metals and other related soil pollutants. Soil Remediation and Plants provides a common platform for biologists, agricultural engineers, environmental scientists, and chemists, working with a common aim of finding sustainable solutions to various environmental issues. The book provides an overview of ecosystem approaches and phytotechnologies and their cumulative significance in relation to solving various environmental problems. - Identifies the molecular mechanisms through which plants are able to remediate pollutants from the soil - Examines the challenges and possibilities towards the various phytoremediation candidates - Includes the latest research and ongoing progress in phytoremediation

Nuclear energy is the one energy source that could meet the world's growing energy needs and provide a smooth transition from fossil fuels to renewable energy in the coming decades and centuries. It is becoming abundantly clear that an increase in nuclear energy capacity will, and probably must, take place. However, nuclear energy and the use of radionuclides for civilian and military purposes lead to extremely long-lived waste that is costly and highly problematic to deal with. Therefore, it is critically important ot understand the environmental implications of radionuclides for ecosystems and human health if nuclear energy is to be used to avoid the impending global energy crisis. The present volume of the EIC Books series addresses this critical need by providing fundamental information on environmentally significant radionuclides. The content of this book was developed in collaboration with many of the authors of the chapters. Given the enormity of the subject the Editor and the Authors had to be judicious in selecting the chapters that would appropriately encompass and describe the primary topics, particularly those that are of importance to the health of ecosystems and humans. The resulting chapters were chosen to provide this information in a book of useful and appropriate length. Each chapter provides fundamental information on the chemistry of the radionuclides, their occurrence and movement in the enivornment, separation and analyses, and the technologies needed for their remediation and mitigation. The chapters are structured with a common, systematic format in order to facilitate comparions between elements and groups of elements. About EIC Books The Encyclopedia of Inorganic Chemistry (EIC) has proved to be one of the defining standards in inorganic chemistry, and most chemistry libraries around the world have access either to the first of second print editon, or to the online version. Many readers, however, prefer to have more concise thematic volumes, targeted to their specific area of interest. This feedback from EIC readers has encouraged the Editors to plan a series of EIC Books, focusing on topics of current interest. They will appear on a regular basis, and will feature leading scholars in their fields. Like the Encyclopedia, EIC Books aims to provide both the starting research student and the confirmed research worker with a critical distillation of the leading concepts in inorganic and bioinorganic chemistry, and provide a structured entry into the fields covered. This volume is also available as part of Encyclopedia of Inorganic Chemistry, 5 Volume Set. This set combines all volumes published as EIC Books from 2007 to 2010, representing areas of key developments in the field of inorganic chemistry published in the Encyclopedia of Inorganic Chemistry. Find out more.