Role of Expandable Clays in the Environmental Fate of Trinitrotoluene Contamination PDF Download

Author:
Publisher:
ISBN:
Category : Clay soils
Languages : en
Pages : 54

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Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
A primary goal of the U.S. military cleanup effort is to develop technologies that can expedite the remediation of explosive contaminants in soils. Nitroaromatic explosives are known to be strongly adsorbed by soils, with as much as 20 to 50 percent of radio-labeled explosives not extractable in controlled degradation studies. This suggests that adsorption of explosives and explosives degradation products onto soil components renders them unavailable to conventional extraction methods. The mechanism of sorption to soil components has been investigated in order to properly address the ultimate fate of explosives contamination. Trinitrotoluene undergoes reductive degradation in which nitro groups are animated to produce aminotoluene compounds. The final compound predicted by this reduction scheme is triaminotoluene. This reaction pathway results in intermediate degradation products of trinitrotoluene which act as weak bases. Protonation of these weak bases produces organic cations which are capable of sorption onto soil components. Sorption experiments were performed to determine the behavior of explosives and explosive by-products on pure clay minerals. X-ray diffraction studies measuring the interlamellar distance of expandable clays show an expansion as contaminants are bound to the clay, indicating displacement of interlayer cations. This intercalation of compounds of environmental interest within the interlamellar regions of expandable clays is an important geochemical event with implications toward a number of environmental disciplines including subsurface contaminant transport, risk assessment, contaminant bioavailability, site remediation, and natural attenuation.

Author:
Publisher:
ISBN:
Category : RDX (Cyclonite)
Languages : en
Pages : 25

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Author: National Research Council
Publisher: National Academies Press
ISBN: 030909447X
Category : Science
Languages : en
Pages : 371

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At hundreds of thousands of commercial, industrial, and military sites across the country, subsurface materials including groundwater are contaminated with chemical waste. The last decade has seen growing interest in using aggressive source remediation technologies to remove contaminants from the subsurface, but there is limited understanding of (1) the effectiveness of these technologies and (2) the overall effect of mass removal on groundwater quality. This report reviews the suite of technologies available for source remediation and their ability to reach a variety of cleanup goals, from meeting regulatory standards for groundwater to reducing costs. The report proposes elements of a protocol for accomplishing source remediation that should enable project managers to decide whether and how to pursue source remediation at their sites.

Author: Clay Minerals Society. Annual Meeting
Publisher:
ISBN:
Category : Clay
Languages : en
Pages : 160

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Author: National Research Council
Publisher: National Academies Press
ISBN: 0309086256
Category : Technology & Engineering
Languages : en
Pages : 433

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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.

Author: Maulin P. Shah
Publisher: Springer Nature
ISBN: 9811518122
Category : Science
Languages : en
Pages : 547

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Microbial or biological degradation has long been the subject of active concern, and the rapid expansion and growing sophistication of various industries in the last century has significantly increased the volume and complexity of toxic residues of wastes. These can be remediated by plants and microbes, either natural origin or adapted for a specific purpose, in a process known as bioremediation. The interest in microbial biodegradation of pollutants has intensified in recent years in an attempt to find sustainable ways to clean contaminated environments. These bioremediation and biotransformation methods take advantage of the tremendous microbial catabolic diversity to degrade, transform or accumulate a variety of compounds, such as hydrocarbons, polychlorinated biphenyls, polaromatic hydrocarbons pharmaceutical substances, radionuclides and metals. Unlike conventional methods, bioremediation does not physically disturb the site. This book describes the basic principles of biodegradation and shows how these principles are related to bioremediation. Authored by leading, international environmental microbiologists, it discusses topics such as aerobic biodegradation, microbial degradation of pollutants, and microbial community dynamics. It provides valuable insights into how biodegration processes work and can be utilised for pollution abatement, and as such appeals to researchers and postgraduate students as well as experts in the field of bioremediation.

Author: Jim C. Spain
Publisher: Springer Science & Business Media
ISBN: 1475794479
Category : Science
Languages : en
Pages : 234

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During the past five years increased awareness of environmental contamination by nitroaromatic compounds has led to a dramatic increase in research on their biodegradation. The resulting discoveries have markedly extended our understanding of degradation mecha nisms and pathways in bacteria and fungi. Futhermore, this new basic knowledge promises the development of field applications of biodegradation systems for nitroaromatic com pounds. In May of 1994, an International Symposium on the Biodegradation of Nitro aromatic Compounds was held in Las Vegas, Nevada. This symposium brought together the scientists at the frontiers of research into the biodegradation of nitro aromatic compounds. The invited speakers were asked to review their area of expertise and write a critical, comprehensive synthesis of their work and related work by others. This book is the result of their efforts. The emphasis of the reviews is on basic research in biodegradation and biotransfor mation. Therefore, the reactions of nitroaromatic compounds in plants, animals, bacteria, fungi, soil, and even nonbiological systems are considered. The goal of the work is to provide the reader with an appreciation of the tremendous range of possibilities for metabolism of aromatic nitro compounds and the experimental approaches used to understand them. This volume should be of interest to biochemists, microbiologists, engineers, toxicologists, and anyone interested in the behavior of synthetic chemicals in the environment or in living systems. Furthermore, a variety of commercial applications can be envisioned for some of the reactions described here.

Author:
Publisher: Noyes Publications
ISBN: 9780815512639
Category : Science
Languages : en
Pages : 533

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State of the art information on in situ treatment technologies for hazardous waste-contaminated soils is presented. Describes for each technology: wastes amenable to treatment, ease of application, potential level of treatment available, reliability, secondary impacts and equipment and reagents required.

Author:
Publisher:
ISBN:
Category : Medicine
Languages : en
Pages : 1748

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Book Description
Vols. for 1963- include as pt. 2 of the Jan. issue: Medical subject headings.