Download or read book Partitioning Tracers for In situ Detection and Quantification of Dense Nonaqueous 1997 Annual Progress Report written by and published by . This book was released on 1997 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The overall goal of the proposed project is to explore the use of partitioning tracers to characterize dense nonaqueous phase liquids (DNAPLs) in subsurface systems. Bulk-phase partitioning tracers will be investigated to detect and determine DNAPL saturation, while interface partitioning tracers will be investigated to measure the area of the DNAPL-water interface. The specific objectives that will be addressed to accomplish this goal are: (1) investigate the use of partitioning tracers to detect and determine both the saturation and interfacial area of DNAPLs in saturated porous media; (2) investigate the effect of rate-limited mass transfer on the transport behavior of partitioning tracers; (3) investigate the effect of porous-media heterogeneity on the transport behavior of partitioning tracers; and (4) develop and evaluate mathematical models capable of simulating the transport of partitioning tracers in complex systems.
Download or read book Partitioning Tracers for in Situ Detection and Quantification of Dense Nonaqueous Phase Liquids in Groundwater Systems 1998 Annual Progress Report written by and published by . This book was released on 1998 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: The overall goal of the proposed project is to explore the use of an innovative in-situ method for the detection and quantification of dense nonaqueous phase liquids (DNAPLs) in water-saturated and unsaturated heterogeneous media. Effective risk assessment and remediation of DNAPL contaminated sites is constrained by the limitations of current site characterization techniques. A major weakness of the current methods is that they provide data at discrete points, such that the probability of sampling a zone of localized DNAPL is quite small. The results of the proposed research will lead to improved techniques for characterizing DNAPL contaminated sites and will enhance the understanding of the distribution of DNAPLs in the subsurface. The use of this methods will reduce the uncertainty associated with risk assessments and remediation planning. The project objectives include exploring partitioning tracers for the detection and quantification of DNAPLs in saturated systems using aqueous tracers and in unsaturated systems using gas-phase tracers. This report summarizes work completed mid-way through year 2 of a 3-year project. Batch experiments have been conducted for a suite of bulk-phase partitioning tracers to determine water- trichloroethene (TCE) partitioning coefficients. Interfacial tension measurements have been made between TCE and solutions of several potential interface partitioning tracers. Preliminary column experiments have been conducted for the aqueous bulk-phase partitioning tracers using columns packed with a homogeneous sand and containing a residual saturation of TCE. These preliminary sets of experiments have enabled selection of suitable tracers for the water-saturated experiments and have lead to improved experimental designs and methods.
Download or read book In situ Characterization of Dense Non aqueous Phase Liquids UUsing Partitioning Tracers 1998 Annual Progress Report written by and published by . This book was released on 1998 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: Major advances have been made during the past year in research on interwell partitioning tracers tests (PITTs). These advances include: (1) progress on the inverse problem of how to estimate the three-dimensional distribution of NAPL in aquifers from the tracer data, (2) the first ever partitioning tracer experiments in dual porosity media, (3) the first modeling of partitioning tracers in dual porosity media, (4) experiments with complex NAPLs such as coal tar, (5) the development of an accurate and simple method to predict partition coefficients using the equivalent alkane carbon number approach, (6) partitioning tracer experiments in large model aquifers with permeability layers, (7) the first ever analysis of partitioning tracer data to estimate the change in composition of a NAPL before and after remediation, (8) the first ever analysis of partitioning tracer data after a field demonstration of surfactant foam to remediate NAPL, and (9) experiments at elevated temperatures. The authors have developed a new analytic approach that has several advantages over existing approaches for inversion of tracer data. First, the technique utilizes an extremely efficient three-dimensional multiphase streamline simulator as a forward model. Second, the parameter sensitivities are formulated in terms of one-dimensional integrals of analytic functions along the streamlines. Thus, the computation of sensitivities for all model parameters requires only a single simulation run to construct the velocity field and generate the streamlines. The inversion of tracer data is then performed using a two-step iterative linearization that involves first lining-up the breakthrough times at the producing wells and then matching the production history. Their approach follows from an analogy between streamlines and ray tracing in seismology. The inverse method is analogous to seismic waveform inversion and thus, allows them to utilize efficient methods from geophysical imaging. The new approach has been applied for estimating permeability distribution based on conservative tracer tests (D.W. Vasco and A. Datta-Gupta: ''Asymptotic Solutions for Solute Transport: A Formalism for Tracer Tomography, '''' Submitted to Water Resources Research, December 1997), and is currently being extended for analysis of partitioning tracer data.
Download or read book Partitioning Tracers for In Situ Detection and Quantification of Dense Nonaqueous Phase Liquids in Groundwater Systems written by and published by . This book was released on 1999 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The overall goal of the project is to explore the use of an innovative in-situ method (partitioning tracer tests) for detection and quantification of dense nonaqueous phase liquids (DNAPLs) in subsurface systems. DNAPLs occur in the subsurface at numerous contaminated sites and can act as long-term sources of groundwater contamination. Both effective risk assessment and remediation of DNAPL-contaminated sites is limited by current site characterization techniques. A major limitation of the current methods is that they provide data at discrete points, such that the probability of sampling a zone of localized DNAPL is quite small. The results of this research will lead to an improved method for characterizing DNAPL-contaminated sites and will enhance our understanding of the distribution of immiscible liquids in the subsurface. The use of this method will help reduce the uncertainty associated with risk assessments and remediation planning.
Download or read book Partitioning Tracers for In Situ Measurement of Nonaqueous Phase Liquids in the Subsurface Final Report 09 written by and published by . This book was released on 2000 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The overall goal of the proposed project is to explore the use of partitioning tracers to characterize dense nonaqueous phase liquids (DNAPLs) in aquifer systems. Bulk-phase partitioning tracers will be investigated to detect and determine DNAPL saturation, while interface partitioning tracers will be investigated to measure the area of the DNAPL-water interface. The specific objectives that will be addressed to accomplish this goal are: (1) Investigate the use of partitioning tracers to detect and determine both the saturation and interfacial area of DNAPLs in saturated porous media. (2) Investigate the effect of rate-limited mass transfer on the transport behavior of partitioning tracers. (3) Investigate the effect of porous-media heterogeneity on the transport behavior of partitioning tracers. (4) Develop and evaluate mathematical models capable of simulating the transport of partitioning tracers in complex systems. This proposal outlines an integrated approach for the development and testing of a unique method for detecting and measuring DNAPL in aquifer systems. The approach combines one-dimensional laboratory experiments, three-dimensional intermediate-scale flow cell experiments, physical methods for DNAPL description (including dual-energy gamma radiation), and advanced modeling techniques. This approach will allow a new, promising technique for characterizing DNAPL in aquifer systems to be verified by established laboratory and numerical methods. The effect of heterogeneity will be examined by the use of a flow-cell packed with layers of variable permeability and containing multiple sample ports. The effect of rate-limited liquid-liquid mass transfer will be investigated by examining the impact of pore-water velocity and DNAPL form on transport of the partitioning tracers. Effective risk assessment and remediation of DNAPL contaminated sites is constrained by the limitations of current site characterization techniques. A major weakness of the current methods is that they provide data at discrete points, such that the probability of sampling a zone of localized DNAPL is quite small. The results of the research will lead to improved techniques for characterizing DNAPL contaminated sites and will enhance our understanding of the distribution of DNAPLs in the subsurface risk assessments and remediation planning.
Download or read book In Situ Characterization of Dense Non Aqueous Phase Liquids Using Partitioning Tracers written by and published by . This book was released on 2000 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Majors advances have been made during the past three years in our research on interwell partitioning tracers tests (PITTs). These advances include (1) progress on the inverse problem of how to estimate the three-dimensional distribution of NAPL in aquifers from the tracer data, (2) the first ever partitioning tracer experiments in dual porosity media, (3) the first modeling of partitioning tracers in dual porosity media (4) experiments with complex NAPLs such as coal tar, (5) the development of an accurate and simple method to predict partition coefficients using the equivalent alkane carbon number approach, (6) partitioning tracer experiments in large model aquifers with permeability layers, (7) the first ever analysis of partitioning tracer data to estimate the change in composition of a NAPL before and after remediation (8) the first ever analysis of partitioning tracer data after a field demonstration of surfactant foam to remediate NAPL and (9) experiments at elevated temperatures.
Download or read book Practical Handbook of Soil Vadose Zone and Ground Water Contamination written by J. Russell Boulding and published by CRC Press. This book was released on 2016-04-19 with total page 718 pages. Available in PDF, EPUB and Kindle. Book excerpt: A synthesis of years of interdisciplinary research and practice, the second edition of this bestseller continues to serve as a primary resource for information on the assessment, remediation, and control of contamination on and below the ground surface. Practical Handbook of Soil, Vadose Zone, and Ground-Water Contamination: Assessment, Prev
Download or read book Contaminants in the Subsurface written by National Research Council and published by National Academies Press. This book was released on 2005-04-23 with total page 371 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Monitored Natural Attenuation of Inorganic Contaminants in Ground Water written by and published by . This book was released on 2007 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: V.3 ... consists of individual chapters that describe 1) the conceptual background for radionuclides, including tritium, radon, strontium, technetium, uranium, iodine, radium, thorium, cesium, plutonium-americium and 2) data requirements to be met during site characterization.
Download or read book Innovative Subsurface Remediation written by Mark L. Brusseau and published by . This book was released on 1999 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume evaluates a selection of new technologies for the remediation of groundwater pollution. It covers techniques for both site remediation and characterization, and many of the techniques described are ready for commercial application.
Download or read book DNAPL Site Evaluation written by James W. Mercer and published by CRC-Press. This book was released on 1993-04-29 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: DNAPL Site Evaluation covers long-term contamination of ground water by DNAPL (dense non-aqueous phase liquids) chemicals. The book develops a framework for planning and implementing DNAPL site characterization activities. It provides detailed methods to identify, characterize, and monitor sites and analyzes their utility, limitations, risks, availability, and cost. Methods to interpret contaminant fate and transport are identified, and new site characterization methods are assessed. DNAPL Site Evaluation will maximize the cost-effectiveness of site investigation/remediation by providing the best information available to describe and evaluate methods to be used for determining the presence, fate, and transport of subsurface DNAPL contamination. The book will be a useful reference for groundwater professionals and environmental regulatory personnel.
Download or read book Characterization Modeling Monitoring and Remediation of Fractured Rock written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2021-01-29 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fractured rock is the host or foundation for innumerable engineered structures related to energy, water, waste, and transportation. Characterizing, modeling, and monitoring fractured rock sites is critical to the functioning of those infrastructure, as well as to optimizing resource recovery and contaminant management. Characterization, Modeling, Monitoring, and Remediation of Fractured Rock examines the state of practice and state of art in the characterization of fractured rock and the chemical and biological processes related to subsurface contaminant fate and transport. This report examines new developments, knowledge, and approaches to engineering at fractured rock sites since the publication of the 1996 National Research Council report Rock Fractures and Fluid Flow: Contemporary Understanding and Fluid Flow. Fundamental understanding of the physical nature of fractured rock has changed little since 1996, but many new characterization tools have been developed, and there is now greater appreciation for the importance of chemical and biological processes that can occur in the fractured rock environment. The findings of Characterization, Modeling, Monitoring, and Remediation of Fractured Rock can be applied to all types of engineered infrastructure, but especially to engineered repositories for buried or stored waste and to fractured rock sites that have been contaminated as a result of past disposal or other practices. The recommendations of this report are intended to help the practitioner, researcher, and decision maker take a more interdisciplinary approach to engineering in the fractured rock environment. This report describes how existing tools-some only recently developed-can be used to increase the accuracy and reliability of engineering design and management given the interacting forces of nature. With an interdisciplinary approach, it is possible to conceptualize and model the fractured rock environment with acceptable levels of uncertainty and reliability, and to design systems that maximize remediation and long-term performance. Better scientific understanding could inform regulations, policies, and implementation guidelines related to infrastructure development and operations. The recommendations for research and applications to enhance practice of this book make it a valuable resource for students and practitioners in this field.
Download or read book Alternatives for Managing the Nation s Complex Contaminated Groundwater Sites written by National Research Council and published by National Academies Press. This book was released on 2013-02-27 with total page 423 pages. Available in PDF, EPUB and Kindle. Book excerpt: Across the United States, thousands of hazardous waste sites are contaminated with chemicals that prevent the underlying groundwater from meeting drinking water standards. These include Superfund sites and other facilities that handle and dispose of hazardous waste, active and inactive dry cleaners, and leaking underground storage tanks; many are at federal facilities such as military installations. While many sites have been closed over the past 30 years through cleanup programs run by the U.S. Department of Defense, the U.S. EPA, and other state and federal agencies, the remaining caseload is much more difficult to address because the nature of the contamination and subsurface conditions make it difficult to achieve drinking water standards in the affected groundwater. Alternatives for Managing the Nation's Complex Contaminated Groundwater Sites estimates that at least 126,000 sites across the U.S. still have contaminated groundwater, and their closure is expected to cost at least $110 billion to $127 billion. About 10 percent of these sites are considered "complex," meaning restoration is unlikely to be achieved in the next 50 to 100 years due to technological limitations. At sites where contaminant concentrations have plateaued at levels above cleanup goals despite active efforts, the report recommends evaluating whether the sites should transition to long-term management, where risks would be monitored and harmful exposures prevented, but at reduced costs.
Download or read book Natural Attenuation for Groundwater Remediation written by Commission on Geosciences, Environment, and Resources and published by National Academies Press. This book was released on 2000-08-31 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the past decade, officials responsible for clean-up of contaminated groundwater have increasingly turned to natural attenuation-essentially allowing naturally occurring processes to reduce the toxic potential of contaminants-versus engineered solutions. This saves both money and headaches. To the people in surrounding communities, though, it can appear that clean-up officials are simply walking away from contaminated sites. When is natural attenuation the appropriate approach to a clean-up? This book presents the consensus of a diverse committee, informed by the views of researchers, regulators, and community activists. The committee reviews the likely effectiveness of natural attenuation with different classes of contaminants-and describes how to evaluate the "footprints" of natural attenuation at a site to determine whether natural processes will provide adequate clean-up. Included are recommendations for regulatory change. The committee emphasizes the importance of the public's belief and attitudes toward remediation and provides guidance on involving community stakeholders throughout the clean-up process. The book explores how contamination occurs, explaining concepts and terms, and includes case studies from the Hanford nuclear site, military bases, as well as other sites. It provides historical background and important data on clean-up processes and goes on to offer critical reviews of 14 published protocols for evaluating natural attenuation.
Download or read book Toxicological Profile for Polycyclic Aromatic Hydrocarbons written by and published by . This book was released on 1995 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book In situ Air Sparging Engineering and Design EM 1110 1 4005 written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
