Bioavailability Of Organic Xenobiotics In The Environment

In the continuing fight against organic environmental xenobiotics, the initial success attributed to bioremediation has paled, in part due to the low availability of xenobiotics entrapped within a soil or sediment matrix. This has generated a very significant wave of interest in the bioavailability issue. However, much experimental evidence is puzzling or contradictory, mechanistic theories are embryonic, and implications for the practice of bioremediation or concerning the natural fate of xenobiotics are still tentative. The debate in Europe and the USA is vigorous. Eastern Europe, following the liberalisation of the economy and political life, is evolving in a similar direction. In many cases, however, limited access to literature sources, severe language barriers, and the lack of a strong pluridisciplinary tradition are hampering the adoption of state of the art techniques. Originally intended to allow scientists in East European countries to become acquainted with the key aspects of the bioavailability debate that is unfolding in the scientific literature in the West, and with its implications for bioremediation efforts, the present book presents a very complete coverage of the theoretical and practical aspects of the (limited) bioavailability of organic xenobiotics in the environment.

Natural and agro-ecosystems are frequently exposed to natural or synthetic substances, which, while they have no direct nutritional value or significance in metabolism, may negatively affect plant functioning. These, xenobiotics, may originate from both natural (fires, volcano eruptions, soil or rock erosion, biodegradation) and anthropogenic (air and soil pollution, herbicides) sources. And, while affected plants have only a limited number of possibilities for avoiding accumulation of these compounds, they do exhibit several enzymatic reactions for detoxification including oxidation, reduction, hydrolysis and conjugation reactions. In agro-ecosystems in particular these mechanisms have great significance in relation to herbicide detoxification and tolerance. In this volume an international group of experts present an overview of the nature and distribution of organic xenobiotics, including their uptake, effects on plant functioning and detoxification mechanisms. The particular significance of glutathione S-transferases in bio-indication and bio-monitoring, and in the detoxification of volatile organic air pollutants and herbicides is evaluated, and their potential significance in phytoremediation and bioaccumulation will be discussed. This volume will be of interest to a wide audience, from graduate students to senior researchers in a wide range of disciplines including plant ecology, plant biochemistry, agriculture and environmental management. It will also be of practical interest to environmentalists, policy makers and resource managers.

This book describes the vast variety of xenobiotics, such as pesticides, antibiotics, antibiotic resistance genes, agrochemicals and other pollutants, their interactions with the soil environment, and the currently available strategies and techniques for soil decontamination and bioremediation. Topics covered include: transport mechanisms of pollutants along the Himalayas; use of earthworms in biomonitoring; metagenomic strategies for assessing contaminated sites; xenobiotics in the food chain; phyto-chemical remediation; biodegradation by fungi; and the use of enzymes and potential microbes in biotransformation. Accordingly, the book offers a valuable guide for scientists in the fields of environmental ecology, soil and food sciences, agriculture, and applied microbiology.

Bioavailability refers to the extent to which humans and ecological receptors are exposed to contaminants in soil or sediment. The concept of bioavailability has recently piqued the interest of the hazardous waste industry as an important consideration in deciding how much waste to clean up. The rationale is that if contaminants in soil and sediment are not bioavailable, then more contaminant mass can be left in place without creating additional risk. A new NRC report notes that the potential for the consideration of bioavailability to influence decision-making is greatest where certain chemical, environmental, and regulatory factors align. The current use of bioavailability in risk assessment and hazardous waste cleanup regulations is demystified, and acceptable tools and models for bioavailability assessment are discussed and ranked according to seven criteria. Finally, the intimate link between bioavailability and bioremediation is explored. The report concludes with suggestions for moving bioavailability forward in the regulatory arena for both soil and sediment cleanup.

Sustainable Environmental Clean-up: Green Remediation includes some natural, clean, and eco-sustainable technologies that have undergone the process of gradual development in past few decades. These technologies include a range of innovative natural and viable materials and offer a clean solution of environmental pollution. It includes case studies of phytoremediation, bioremediation (microbial removal of pollutant), constructed wetlands, natural media filtration for the sustainable environmental cleanup. Sustainable Environmental Clean-up: Green Remediation includes coverage of: Recent trends in eco-sustainable green remediation, Role of constructed wetlands in green remediation, Factor responsible for biodegradation of organic pollutants, Remediation through natural media (Sand, gravel, stope-chips), Microbes and their role in green remediation. Presents recent trends in eco-sustainable green remediation Covers the role of constructed wetlands in green remediation Outlines the factors responsible for biodegradation of organic pollutants Discusses remediation through natural media (Sand, gravel, stope-chips) Explains microbes and their role in green remediation Includes the role of endophytic microbes in organic contamination management

Soil MineralOrganic MatterMicroorganism Interactions and Ecosystem Health presents up-to-date information on the dynamics, transformations and bioavailability of xenobiotics in soil and their impact on ecosystem health, the ecological significance of interactions of metals and metalloids with soil colloids, enzymes and microbial biomass and the role of minerals-organic matter - soil biota interactions in the restoration of perturbed ecosystems. The title comprises two volumes: Volume A: Dynamics, Mobility and Transformation of Pollutants and Nutrients. Volume B: Ecological Significance of the Interactions mong Clay Minerals, Organic Matter and Soil Biota. This title could serve as a basic reference for students, teachers, and researchers by providing in-depth knowledge of the current state of the art in a particular area of soil science.

The book presents the latest research findings and prospects on soil mineral-organic matter-microorganism interactions. It includes topics covering mechanisms of transformations, dynamics and bioavailability of heavy metals, radionuclides, biomolecules and nutrients immobilized on soil minerals, humic substances, mineral-humic complexes and microorganisms and their impact on plant, animal and human health. The book is organized into six parts.