bluuebunny/crossref_metadata_2025_split huggingface dataset:
In‐situ sparging: Mass transfer mechanisms
Authors: Clayton Wilson S. , Bass David H. , Ram Neil M. , Nelson Christopher H. 
Published: February 2007

AbstractIn‐situ sparging has been accepted as a method to rapidly remediate groundwater at considerably lower costs compared to remedies based on groundwater recovery alone. The success of in‐situ sparging depends on effective mass transfer between air and contaminated media in the subsurface. Factors affecting mass transfer include advective airflow, diffusive transport, interphase chemical partitioning, and chemical and biological reaction rates between sparged gases and subsurface contaminants, minerals, and naturally occurring organic compounds. Understanding these factors can increase the design efficiency of in‐situ sparging and assist in developing sparging systems that use gases other than air (i.e., oxygen, ozone, and methane).
Perspective and trends in the environmental remediation industry
Authors: Findley Dean , Whitridge Jill 
Published: February 2007

AbstractThe approach to management and execution of remediation projects has changed drastically over the past decade, as remedial project managers have begun to understand and accept the numerous environmental regulations developed in the mid‐1980s. For example, the adversarial relationship that once existed between regulators and owners has become more cooperative. This article documents trends over time in remediation project practices and quantifies the impact these trends have had on the cost and schedule performance of projects. Proven successful practices are highlighted, and those with the potential for improving project performance further are also discussed.
Preliminary comparison of alternative designs for soil remediation by bioventilation
Authors: Gates Walter C. , Marshall Elizabeth M. 
Published: February 2007

AbstractComputer simulation provides a powerful tool for comparing alternative designs of remediation processes. The software package FLUENT copes successfully with subsurface three‐dimensional flow fields, multiple and directional permeabilities, wide spatial variations in subsurface gas velocities, and the presence of surface structures. FLUENT can provide an invaluable method for comparing remediation efficiencies among competing design alternatives. This article features case studies to illustrate the benefits that simulation studies provide before and during the initiation of remedial actions using bioventing.
Stalking the RCRA leapfrog
Authors: Gibbons Robert D. 
Published: February 2007

AbstractIn the preceding article, “RCRA Leapfrog: How Statistics Shape and in Turn Are Shaped by Regulatory Mandates,” Dr. Kirk Cameron expressed his opinion on how the RCRA statistical program had developed into its current state, focusing on interactions that have occurred between regulators, geologists, regulated individuals, and a small group of professional statisticians over the past 10 to 15 years. Here, Dr. Robert Gibbons, a member of that small group, responds to some of Dr. Cameron's comments.
Influences on RCRA corrective action costs for nonfederal facilities
Authors: Gampel Mindy 
Published: February 2007

AbstractThousands of known hazardous waste sites across the country require remediation, with thousands more yet to be discovered, at estimated cleanup costs of billions of dollars over the next few decades. With this enormous financial burden placed on all members of society through increased prices, taxes, and lost investment opportunities, policy makers face the difficult prospect of defining cleanup standards that meet the goals of protecting human health and the environment and achieving remediation in the most cost‐effective manner. Using a statistical methodology to investigate factors influencing the cost of RCRA corrective action, this article examines site characteristics that significantly affect cleanup costs and explains differences in costs among EPA's four proposed Subpart S corrective action options.
Environmental legislative accomplishments: The 104th congress in review and a look at what's ahead
Authors: Schaaff Lesley‐Anne 
Published: February 2007

AbstractContrary to many's expectations, the Republican‐led 104th Congress passed a substantial amount of environmental legislation. In addition to a variety of bills that received limited public attention, two major environmental laws—the Safe Drinking Water Act Amendments and the Food Quality Protection Act—were passed and signed into law. Still, many important legislative efforts were left unfinished at the end of the second session and will resurface in the 105th Congress. This article discusses the environmental legislation that passed in the 104th Congress and explores what environmental legislative initiatives will be addressed in the 105th Congress. (While not intended to be all‐inclusive, the article mentions most major environmental legislation, with a particular focus on waste issues.)
Using uncertainty analysis to reduce costs at a pump‐and‐treat site
Authors: Elmore Andrew Curtis , Vandeberg Mark A. 
Published: February 2007

AbstractThe former Nebraska Ordnance Plant site in east‐central Nebraska was included on the National Priorities List because of explosives and trichloroethene contamination. The preferred groundwater remedy includes hydraulic containment of the contaminated groundwater and focused extraction of the more highly contaminated groundwater as components of the remedial action. The purpose of hydraulic containment is to stop the spread of contamination, while the more aggressive focused extraction will be used to speed up the remediation and reduce total cleanup costs. This case study illustrates how straightforward groundwater models were combined with uncertainty analysis to select a precise definition of the focused extraction areas. The purpose of the analysis was to reduce ultimate remediation costs, given the significant uncertainty associated with the estimated remediation times. The selected definition provides a basis for more sophisticated groundwater modeling, the goal of which was to locate extraction wells and define their flow rates. The batch flushing model provided the governing equations, and Monte Carlo analysis was used for the uncertainty analysis. All of the analysis was performed on a personal computer using commercially available software.
Cleanup levels for dioxin‐contaminated soils
Authors: Hirschhorn Joel S. 
Published: February 2007

AbstractEPA's use of a 1 part per billion (ppb) level for dioxin contamination in residential soils is shown to be too high and not protective of public health. It was derived in a 1984 cancer risk assessment by another federal agency, but it is inconsistent with risk‐based levels of 2 to 4 parts per trillion (ppt) obtained by using EPA's standard risk assessment methods. EPA has called the 1 ppb level a policy‐based level, which correctly distinguishes it from a risk or health‐based cleanup standard. The 1984 assessment is shown in this article to have considerable shortcomings. For over a decade, dioxins have been left in soils at levels posing health risks and sometimes at levels that EPA is legally required to address. Moreover, noncancer effects have been ignored, but recent work has shown them to support action at low ppt levels. To protect public health, be consistent with current scientific knowledge and other EPA policies, reduce confusion in the environmental management community, and be responsive to public demands for stringent dioxin cleanups, new EPA policy guidance for dioxin soil cleanups is needed, and key elements are presented in this article. In an ad hoc fashion, EPA Region 4 has recently used a 200 ppt dioxin cleanup level for residential soil, acknowledged to correspond to a one‐in‐ten‐thousand cancer risk, at two Superfund sites, which environmental professionals should be aware of. This suggests a shift in EPA policy.
A method to compare groundwater cleanup technologies
Authors: Quinton Gary E. , Buchanan Ronald J. , Ellis David E. , Shoemaker Stephen H. 
Published: February 2007

AbstractDuPont has developed a method to compare, on a consistent economic basis, in situ remediation technologies. The methodology employs a template site with a perchloroethylene plume 1000 ft long by 400 ft wide, and incorporates various aquifer thicknesses and depths. Variables considered in the methodology include duration of the remediation; estimated engineering and flow/transport modeling costs; equipment costs; and operation, maintenance, and monitoring costs. In this article, substrate‐enhanced anaerobic bioremediation, intrinsic bioremediation, in situ permeable reactive barriers, and pump‐and‐treat systems are evalutated. Cost metrics include present cost, cost per pound of contaminant removed, and cost per 1000 gals treated, using a discounted cash‐flow analysis. Costs of the remedial alternatives increase starting from intrinsic bioremediation, to substrate‐enhanced anaerobic bioremediation, to a biological substrate‐enhanced anaerobic barrier, to in situ permeable reactive barriers, to pump‐and‐treat systems with air stripping and carbon adsorption.
Use of lignin degrading fungi in bioremediation
Authors: Azadpour Azadeh , Powell Patricia D. , Matthews John 
Published: February 2007

AbstractThe use of lignin degrading fungi for decomposition of a wide variety of xenobiotics has become an area of intensive research. One distinct advantage of lignin degrading fungi over bacteria is that they do not require preconditioning to a particular pollutant prior to transformation. This degradative ability has been attributed to a nonspecific and nonstereoselective extracellular lignin‐degrading enzymatic system (ligninase) which is induced by the fungi under nitrogen or carbon‐limiting conditions (Reid, 1979). Ligninases (lignin‐peroxidases) are responsible for the initial oxidative attack on lignin and other complex molecules via formation of a free radical thereby leading to depolymerization of complex molecular structures. Potential degradative ability of peroxidases may extend to include (1) sorbed contaminants, (2) high molecular‐weight, hydrophobic contaminants, and (3) complex mixtures of chemicals typical of a contaminated site.
The impact of high level gamma radiation on immobilized waste forms in polymeric matrices
Authors: Soundararajan R. , Lee O. Lawrence , Haugse A. Leonard 
Published: February 2007

AbstractA new polymer‐based composite binder was developed for the containment/immobilization of radioactive waste forms. This material was subjected to a variety of physicochemical tests to determine its suitability for this purpose. It appears that this composite material possesses superior qualities in terms of resisting radiation damage, retaining the radio isotopes after radiation exposure, and resisting biodegradation. Further, a combination of chemical fixation/immobilization technology with the radiation‐resistant binder was studied. Our evaluation procedures, the results, and its potential applications based on our conclusions are presented in this article.
Successful Deployment of an Innovative Environmental Technology: The Terra‐Kleen Experience
Authors: Cash Alan B. , Miller Melvin N. 
Published: February 2007

AbstractThe National Research Council's report, Innovations in Ground Water and Soil Cleanup: From Concept to Commercialization, reviewed the implementation of innovative remediation technologies and portrayed a bleak outlook for them. Conversely, Terra‐Kleen has invented, patented, permitted, and profited through the use of an innovative technology in the current market. Terra‐Kleen has implemented a solvent extraction technology for the removal of PCBs, PAHs, and chlorinated pesticides from soil, sediment, and debris. To date, Terra‐Kleen has successfully processed over 23 million pounds of PCB‐contaminated soil in Alaska, California, Florida, Ohio, and Oklahoma. The company has been profitable each year since its inception, and has averaged a revenue growth rate of 94 percent per year for the last four years. Corporate growth has been financed entirely through profits and conventional bank loans at favorable interest rates. This article reviews the factors that have led to Terra‐Kleen's success, overviews the solvent extraction technology, and details specific projects that have implemented the technology.
Application of the SOLVTM Process: A Total Systems Approach to Environmental Remediation
Authors: Getman Gerry D. 
Published: February 2007

AbstractCommodore Solution Technologies, Inc. has developed an innovative total systems approach to environmental remediation that utilizes a patented chemistry called Solvated Electron Technology (SETTM). Solvated electron solutions are some of the most powerful reducing agents know. Formed by dissolving alkali and alkaline‐earth metals in anhydrous liquid ammonia to produce a solution of metal cations and free electrons, solvated electron solutions are capable of providing reductants of great activity and uniqueness. They provide a highly useful mechanism for the reductive destruction of many organic molecules and are extremely effective in the dehalogenation of halogenated organic compounds. Commodore has received a nation‐wide EPA operating permit for the nonthermal destruction of PCBs using this process. The SoLVTM process is a total solution approach that incorporates SETTM with pre‐and post‐treatments, when necessary, for environmental cleanup. It is applicable to a broad range of substrates including liquids, solids, soils, and job materials. This article presents results from several pilot, field, and commercial validation studies utilizing the SoLVTM process.
In‐Situ Fenton‐Like Oxidation of Volatile Organics: Laboratory, Pilot, and Full‐Scale Demonstrations
Authors: Greenberg Richard S. , Andrews Thomas , Kakarla Prasad K. C. , Watts Richard J. 
Published: February 2007

AbstractLaboratory, pilot, and full‐scale experiments were used to evaluate and optimize the ISOTECSMremedial process at a warehousing facility in Union, New Jersey. Based on modified Fenton's oxidative chemistry, the ISOTECSMprocess uses a proprietary catalytic agent that delays formation of reactive hydroxyl radicals. This allows adequate dispersion of the hydroxyl radicals, which is an oxidizing agent, throughout a contaminant plume. Ground‐water at the site was contaminated with high levels of gasoline and waste oil constituents, principally BTEX and MTBE. Bench scale microcosm studies were used to evaluate the appropriate site‐specific stoichiometric relationships between catalyst, stabilizers, and oxidizers; the effect of contaminant type and concentration; and the pH optima. Based on results of the laboratory studies, a pilot‐scale study was performed at the site. One injection point for catalyst, stabilizers, and oxidant was installed in the contaminated zone at the site, with one hydraulically connected downgradient well used for monitoring. A single treatment of the reagents in the optimal stoichiometry determined from the laboratory study was injected in‐situ over a period of three days. A 98.5 percent reduction in volatile organics was observed in the area treated, with the radial extent of treatment estimated to be approximately 20 feet, based on the presence of hydroxyl radicals detected in hydraulically connected areas and at the surface. The full‐scale process employed six injection points and three treatment cycles over a three‐month period. Subsequent to treatment, contaminant levels were either nondetectable or were reduced to below applicable New Jersey groundwater standards, with regulatory closure on the site achieved in less than one year.
Commercialization of Dredged‐Material Decontamination Technologies
Authors: Jones Keith W. , Guadagni Anthony J. , Stern Eric A. , Donato Kerwin R. , Clesceri Nicholas L. 
Published: February 2007

AbstractThis article describe a unique federal project aimed at the commercialization of different technologies for the decontamination of dredged material. The project is organized so that commercialization is achieved in a seamless way, starting with validation at the bench‐ and pilot‐scale levels, and ending with the actual construction of operational facilities. This is the first integrated sediment decontamination program in which a step‐wise bench‐scale validation process of innovative/emerging technologies will scale‐up to a production‐scale facility capable of processing up to 375,000 m3 of dredged material per year. The need to develop public‐private partnerships for the facility construction is emphasized as a way of obtaining adequate finding for capital and operating costs during the startup time of the commercialization process. It is expected that the end result of the project work will be the creation of economically‐viable, self‐sustaining decontamination technology companies.
Geophysical and Hydrologic Monitoring of Air Sparging Flow Behavior: Comparison of Two Extreme Sites
Authors: Lundegard Paul D. , LaBrecque Doug J. 
Published: February 2007

AbstractThe distribution of air around injection wells is an important determinant of the effectiveness, design, and cost of air sparging remediation systems. High‐level air sparging field tests were conducted at two sites for the purpose of determining the pattern of airflow under widely different subsurface conditions. One site consisted of relatively homogeneous dune sand (Site A). The other consisted of highly heterogeneous glacial till (Site B). At both sites, cross‐borehole electrical resistance tomography (ERT) was used to image the principal region of airflow in the saturated zone. The response of conventional monitoring data was compared with the ERT results. At Site A, the principal region of airflow was approximately symmetric about the sparge well and only 2.4 m in radius. At Site B, the pattern of airflow was much more complex and had a major horizontal component. In both site studies, conventional monitoring data provided a much more ambiguous indication of the region of airflow in the saturated zone than did ERT. The investigations at these two sites demonstrate that, while the exact distribution of injected air is not readily discernible by conventional monitoring, the character of the airflow pattern can be recognized when appropriate physical response data are collected. Such response data can be used to evaluate site suitability for air sparging and to improve the system design and operation.
In situ Remediation of Metals Comes of Age
Authors: Brown Richard A. , Leaby Maureen C. , Pyrih Roman Z. 
Published: February 2007

AbstractSince the early 1970s, technologies for remediating organic contamination in soils and groundwater have evolved through three stages with primary emphasis on (1) gross removal processes, (2) active in situ treatment, and (3) risk‐based closure and natural attentuation. Technologies for treating metals contamination are evolving through similar stages. In the late 1990s, metals remediation has arrived at the second stage in which a wide range of in situ technologies are available either to extract metals directly from the subsurface or to render them immobile and harmless. In situ geochemical fixation is an example of a commercial technology capable of addressing a wide range of metals contamination sites. Four case histories demonstrate the versatility of this approach. Other promising technologies for treating metals contamination are also emerging. These include geokinetics, biocatalytic precipitation processes, phytoremediation, and artificial wetlands. As our knowledge continues to grow, the most elegant solutions to metals contamination will rely more and more heavily on the soil's natural capacity to stabilize and immobilize metals over time.
A Complete Remediation System for Uranium‐Contaminated Soils: Application to a Uranium‐Contaminated Site at Los Alamos National Laboratory
Authors: Mason Caroline F. V. , Lu Ningping , Turney William R. J. R. , Williams Matthew 
Published: February 2007

AbstractA description of a complete remedial scheme for a uranium‐contaminated site is presented. Results for the example site are discussed. Volume reduction for the contaminated soil was greater than 99 percent and secondary waste volumes were kept to a minimum. The stages of physical separation for radioactive segregation, and chemical separation and immobilization of soluble uranium are universally applicable to all uranium contaminated sites when tailored to specific site requirements. Discussion is presented for adaptation to different soil types and different chemical forms of uranium.
The Market for Waste Vitrification Technology
Authors: Sigmon Brent , Skorka Maria B. 
Published: February 2007

AbstractWaste vitrification technology has largely been developed by the United States Department of Energy (DOE). Numerous vendors offer vitrification units, and a number of commercial and large pilot applications have been made. Nevertheless, the industry is still in its infancy and does not dominate any waste treatment niche.DOE funding of vitrification technology development is nearing an end, and DOE waste treatment is being privatized, with private bidders selecting the technologies and offering to treat wastes for a per‐unit fee. Thus, the DOE market is shifting from a cost‐plus, largely R&D environment to a fixed‐fee environment in which vendors and waste treatment contractors must accept technological risks.Significant quantities of DOE waste are still uncommitted, but the number of vendors is larger than the market can possibly sustain. Domestic private sector opportunities are limited and vendors are looking to foreign markets with less mature treatment capacity and growing demand.
Groundwater Remediation via Marcro Porous Polymer Extraction
Authors: van der Meer A. B. , Brooks Paul E. 
Published: February 2007

AbstractAkzo Nobel's Macro Porous Polymer Extraction (MPPE) technology effectively removes dissolved hydrocarbons from groundwater via liquid‐liquid extraction with an innovative medium. Excellent performance in removal of chlorinated, aromatic, and aliphatic solvents, coupled with simple, robust design, make MPPE an attractive process for groundwater remediation applications.Hydrocarbon‐contaminated water is passed through a column packed with MPPE particles. An extraction fluid, immobilized within the polymer matrix, removes the hydrocarbons from the water. All hydrocarbons with affinity for the extraction fluid (compared to water) are removed. Regeneration is accomplished in situ with low‐pressure steam. The steam volatilizes the hydrocarbons but not theimmobilized extraction fluid. Volatilized hydrocarbons are condensed and then separated from condensate by gravity. The hydrocarbon product is available for recycle or reuse.MPPE systems achieve removal efficiencies of 99.99 percent for wide varieties and combinations of aliphatic, aromatic, and chlorinated compounds. For a broad range of mass loadings and effluent requirements, especially rigorous ones, the MPPE system offers lower investment and operating costs than traditional water treatment technologies. Currently, 14 industrial units are running or under construction in the United States and Europe. Eight of these are treating groundwater.