Physical, Chemical, and Biological Factors Contributing to the Fractionation of PCB Congeners in Aquatic Sediments PDF Download

Author: Dong-Son Vu Pham
Publisher:
ISBN:
Category :
Languages : en
Pages : 466

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Author: National Research Council
Publisher: National Academies Press
ISBN: 0309073219
Category : Political Science
Languages : en
Pages : 451

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Book Description
This book provides a risk-based framework for developing and implementing strategies to manage PCB-contaminated sediments at sites around the country. The framework has seven stages, beginning with problem definition, continuing through assessment of risks and management options, and ending with an evaluation of the success of the management strategy. At the center of the framework is continuous and active involvement of all affected parties-particularly communities-in the development, implementation, and evaluation of the management strategy. A Risk-Management Strategy for PCB-Contaminated Sediments emphasizes the need to consider all risks at a contaminated site, not just human health and ecological effects, but also the social, cultural, and economic impacts. Given the controversy that has arisen at many PCB-contaminated sites, this book provides a consistent, yet flexible, approach for dealing with the many issues associated with assessing and managing the risks at Superfund and other contaminated sites.

Author: Michael Christopher Scullion
Publisher:
ISBN:
Category : Sediment capping
Languages : en
Pages : 164

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Abstract: Polychlorinated biphenyls (PCBs) were heavily used for over fifty years in industrial applications, primarily inside capacitors and transformers. Over twenty years after their phase-out in the United States PCBs are still one of the most widespread contaminants in the environment. PCBs are stable compounds with low aqueous solubility and vapor pressure. These unique properties led to the extensive use of PCBs and are also responsible for their continued presence in the environment today. Due to their hydrophobic nature PCBs tend to accumulate in soils and sediments, and also bioaccumulate in the fatty tissues of aquatic organisms. At higher levels of the food chain, biomagnification produces elevated PCB concentrations in tissue due to the transfer of PCBs from smaller organisms consumed by the larger organisms. Several locations across the United States have fish consumption advisories in place due to PCB contamination. Currently used management techniques include monitored natural recovery, in- situ capping, and dredging and dewatering. All of these methods have major drawbacks preventing their wide-scale use. Monitored natural recovery is subject to a large degree of uncertainty and is also viewed negatively by the public. In-situ capping is prone to disruption and caps are difficult to install at a controlled thickness. Dredging and dewatering is the most commonly used process because it physically removes contaminants from the site. However, it is also a very time consuming and costly process. An emerging technology in contaminated sediment management is active capping involving the use of a sorbent material instead of inert sand to control the release of contaminants from sediment. The application of the sorbent has been shown to be a problem, however a new product from CETCO (reactive core mat, RCM) has shown the potential to alleviate this problem. This study examines sediment management technologies in two parts. First, sediments from three geographically diverse locations across the Great Lakes were characterized to examine trends in the distribution of PCBs throughout the sediment based on physical and chemical characteristics. The second part of the work evaluates the performance of CETCO's organoclay, activated carbon, and sand in sediment capping applications. Sediment characterization involved measuring a variety of physical and chemical properties of bulk sediment from the Ashtabula River, the Lower Fox River, and the Grand Calumet River. Sediment fractions were isolated in order to evaluate variations in the carbon and nitrogen content, and the PCB content as a function of sediment grain size and specific gravity. Results from the characterization suggest that PCBs tend to accumulate in the large-sized, less-dense organic fraction in sediments with low levels of PCB contamination and low bulk sediment carbon concentration. The distribution of PCBs is more uniform in sediments with larger levels of contamination, and higher bulk carbon content. Evaluation of the sorbents in ten day equilibrium batch tests showed for the two PCB congeners examined that activated carbon has a greater affinity for PCBs than organoclay. Both sorbents were found to have a greater affinity for the more highly chlorinated PCB congener, which is consistent with the literature. Consolidation tests used to simulate rapid dewatering revealed that the majority of PCBs released from the sediment are associated with suspended particles. The organoclay and activated carbon both proved to be more effective at reducing PCB release than sand; however, the organoclay was better able to control release for all PCB congeners examined, reducing the total amount of release by 94 percent. Loose organoclay and an organoclay filled RCM were found to be equally effective at removing PCBs during dewatering. The results of this study suggest that sediment characterization at a given site may be beneficial when choosing an appropriate management strategy. CETCO's organoclay proved to be more effective during rapid dewatering than activated carbon, and the use of an RCM to retain the capping material was equally effective in removing PCBs from the pore water.

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: Richard A. Baldino
Publisher:
ISBN:
Category :
Languages : en
Pages : 428

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Author: Obaid Faroon
Publisher: WHO
ISBN:
Category : Medical
Languages : en
Pages : 68

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Polychlorinated Biphenyls (PCBs) are synthetic chlorinated hydrocarbon compounds, produced commercially since 1929 for use in a variety of products including plastics and adhesives, surface coatings, inks, flame retardants, pesticides and paints. PCBs are environmentally persistent, and accumulate in the food chain. They are designated by the Stockholm Convention on Persistent Organic Pollutants as persistent pollutants, and many countries have severely restricted or banned the production of PCBs. This report evaluates the effects of PCBs on human health, caused due to exposure by inhaling contaminated air or ingesting contaminated food and water.

Author: Gwen O'Sullivan
Publisher: Newnes
ISBN: 0444594515
Category : Science
Languages : en
Pages : 424

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Book Description
Environmental Forensics for Persistent Organic Pollutants represents the state-of-the-art in environmental forensics in relation to persistent organic pollutants (POPs). The book is a complete reference for practitioners and students, covering a range of topics from new analytical techniques to regulatory and legal status in the global community. Through case studies from leading international experts, real-world issues — including the allocation of responsibility for release into the environment — are resolved through the application of advanced analytical and scientific techniques. This book introduces and assesses the development of new techniques and technologies to trace the source and fate of newly emerging and classic POPs (perfluoroalkyl substances, brominated flame retardants, organochlorine pesticides, perfluorinated chemicals, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls) in environmental media, including atmospheric, marine, freshwater, and urban environments. Real-world case studies show the application of advanced analytical and scientific techniques Discussion of GC*GC provides an introduction and assessment of a novel technique from leaders in the field Introduces the development of new analytical techniques (such as 2-D GC*HC and LC*LC) to trace the source and fate Raises awareness about the health and environmental impact of persistent organic pollutants (POPs) Outlines the development of international measures to control POPs so that chemists can understand the legal issues

Author:
Publisher:
ISBN:
Category : Freshwater invertebrates
Languages : en
Pages : 150

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Sediment contamination is a widespread environmental problem that can potentially pose a threat to a variety of aquatic ecosystems. The sediment test methods in this manual will be used by The United States Environmental Protection Agency (USEPA) to make decisions under a range of statutory authorities concerning such issues as: dredged material disposal, registration of pesticides and toxic substances, superfound site assessment, and assessment and cleanup of hazardous waste treatment, storage, and disposal facilities. The use of uniform sediment testing procedures by USEPA programs is expected to increase data accuracy and precision, facilitate test replication, increase the comparative value of test results, and ultimately, increase the efficiency of regulatory processes requiring sediment tests.

Author: United States. Environmental Protection Agency. Sediment Oversight Technical Committee
Publisher:
ISBN:
Category : Environmental protection
Languages : en
Pages : 234

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Book Description
This document is a compendium of scientifically valid and accepted methods that can be used to assess sediment quality and predict ecological impacts...the intent here is to provide the most useful overall measures or predictors of ecological impacts currently in use rather than procedures that may have limited application outside of a particular regulatory framework... parag The information provided in the compendium on the relative strengths and weaknesses of the different assessment methods can provide assistance in selecting the appropriate methods.

Author: Erik R. Christensen
Publisher: John Wiley & Sons
ISBN: 1118111761
Category : Technology & Engineering
Languages : en
Pages : 447

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Book Description
There is need in environmental research for a book on fresh waters including rivers and lakes. Compared with other books on the topic, this book has a unique outline in that it follows pollution from sources to impact. Included in the text is the treatment of various tracers, ranging from pathogens to stable isotopes of elements and providing a comprehensive discussion which is lacking in many other books on pollution control of natural waters. Geophysical processes are discussed emphasizing mixing of water, interaction between water and the atmosphere, and sedimentation processes. Important geochemistry processes occurring in natural waters are described as are the processes specific to nutrients, organic pollutants, metals, and pathogens in subsequent chapters. Each of these chapters includes an introduction on the selected groups, followed by the physicochemical properties which are the most relevant to their behavior in natural waters, and the theories and models to describe their speciation, transport and transformation. The book also includes the most up to date information including a discussion on emerging pollutants such as brominated and phosphate flame retardants, perflurochemicals, and pharmaceutical and personal care products. Due to its importance an ecotoxicology chapter has been included featuring molecular biological methods, nanoparticles, and comparison of the basis of biotic ligand model with the Weibull dose-response model. Finally, the last chapter briefly summarizes the regulations on ambient water quality.