221 research outputs found
A Fiber Optic Spectroscopic Analysis of Diuron Sorption/Desorption Processes in Subsurface Media
The quantitative assessment of sorption and desorption processes is vital to the complete understanding of contaminant fate and transport in the subsurface. The sorption and desorption of a synthetic organic pesticide, diuron, was studied by optical ultraviolet (UV) absorption spectroscopy in two configurations. The first utilized the "grab sample" method and a conventional laboratory benchtop UV/VIS spectrophotometer, and the second employed a fiber optic spectrophotometer. The "grab sample" method is susceptible to systematic errors related to the removal of the sample from the subsurface system for analysis. Fiber optic spectrophotometry has the potential for noninvasive, nondestructive measurements obtained within the subsurface media. The hypothesis of this work was that fiber optic spectrophotometry can be used to determine the fate and transport of a pesticide in laboratory systems of subsurface media, using a one dimensional column configuration. The results of this research demonstrate that fiber optic spectroscopic methods can be used for one-dimensional subsurface media column sorption/desorption and tracer experiments under the conditions used in this study. In addition, sorption kinetic experiments indicate that equilibrium conditions are not attained after 140 days of equilibration. Data from equilibrium distribution experiments support this conclusion.Master of Science in Environmental Engineerin
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Integration of Raman Spectroscopy and Cone Penetration Technology Characterize Chlorinated Hydrocarbon Contaminant Plumes
The goal of the project was the development and integration of a Raman spectroscopy unit with a Cone Penetration Technologies (CPT) system for use in locating contamination below the ground surface
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Characterization of Volatile Organic Compound Emissions from Anthropogenic and Emerging Biogenic Sources
Volatile organic compounds are emitted by myriad sources. This thesis investigates trends in emissions on global, regional, and local scales. Globally, an increasing trend in ethane and propane emissions was observed, mainly as a result of oil and natural gas (O&NG;) development. Regionally, air composition varied as a result of the efficacy of emission controls from mobile and industrial sources, and unconventional O&NG; development. Unconventional O&NG; development has also had a demonstrated effect of Colorado’s Northern Front Range. An elevation gradient was observed that suggests emissions from metropolitan and O&NG; development centers in this area influence air composition in the adjacent foothills. A spatial gradient of O&NG; tracers was also observed; mixing ratios increased as distance to an area of concentrated O&NG; development decreased. Given the ever increasing proximity of O&NG; emissions to population centers, concerned citizens desire a method to assess air quality in and around their homes, schools, and offices. An affordable method for measuring C3-C5 alkanes was developed utilizing passive adsorbent sampling cartridges, though further experimentation is needed to determine the absolute accuracy of these devices. Finally, VOC emissions from soil and bacteria are characterized. Soil VOC emissions mirrored the “Birch Effect”, and spiked following a wetting event. Bacterial VOC emission profiles displayed strong taxonomic and phylogenetic signals, and suggest VOC play a role in finer-scale patterns of ecological diversity.</p
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Characterization of DNAPL Using Fluorescence Techniques
Dense non aqueous phase liquid (DNAPL) contaminants, comprised of chlorinated aliphatic compounds, are a major source of groundwater contamination at the Savannah River Site (SRS). To successfully remediate a site contaminated by DNAPLs, it is imperative that the slowly dissolving, non-aqueous phase source be found and removed. There are few technologies that can successfully and consistently detect DNAPLs in the subsurface either directly or by inferred measurements. Because of the use of chlorinated solvents to remove petroleum-based cutting oils and lubricants at SRS (and other manufacturing sites) in degreasing operations, waste solvents may contain small amounts of the oils and lubricants. This mixture will fluoresce when excited by light of wavelengths capable of being transmitted over optical fiber. Samples of DNAPL from the A/M area of SRS were analyzed to assess the possibilities of contaminant detection by fluorescence spectroscopy. The DNAPL sample exhibited a strong, distinct fluorescent spectrum when exposed to an appropriate excitation wavelength. A cone penetrometer-based, laser induced fluorescent system may be capable of providing direct detection of DNAPLs in the subsurface based on these results
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RECOMMENDATIONS FOR PHASE II VADOSE ZONE CHARACTERIZATION AND MONITORING AT THE E-AREA DISPOSAL SLIT TRENCHES AND MEGA-TRENCH
A Radiological Performance Assessment Maintenance Plan (SDW, 1997) was prepared in response to Recommendation 94-2 made by the Defense Nuclear Facility Board (DNFSB) and establishes a requirement for preparing and implementing the E-Area Monitoring Program (EMOP). Based on the results of a statistical analysis of the existing groundwater monitoring network at the Burial Ground and a review of alternative monitoring strategies, a vadose zone monitoring system (YZMS) was selected for the EMOP. The EMOP (SWD, 1998) was prepared in 1998 and describes a phased approach for implementation. The YZMS was designed to detect contamination before it reached the water table and includes collection of pore water samples from sediments above the water table and monitoring pore water pressure and water content of the unsaturated sediments that comprise the vadose zone. This information is then used to calculate the flux of contaminants for comparison with the requirements specified in the E-Area Performance Assessment. In 1999, Phase I of the EMOP was implemented by installation of advanced tensiometers, water content sensors, and vertical and angled lysimeters. In addition several cone penetrometer logs of resistivity and stress ratio were collected and shelby tube samples were collected for measurement of hydraulic properties. Results from Phase I of the EMOP show that the general strategy and techniques selected are adequate for monitoring moisture conditions and contaminant migration. Data from Phase I of the EMOP was used to prepare a numerical model of moisture flow beneath a typical disposal trench. The moisture contents, pore pressure, and flow patterns predicted by the model were compared with field data and used to improve the components of Phase II of the EMOP. Based on these data and the numerical analysis of moisture movement at a typical disposal trench, the objectives of the Phase II EMOP characterization and monitoring are: (1) Collect additional data on moisture release properties to minimize uncertainty in flux calculations; (2) Use neutron probe to measure moisture profile and validate water content sensors; (3) Calibrate neutron probe with site specific calibration curve; (4) Locate tensiometers to provide data useful for calculation of hydraulic gradient; and (5) Incorporate new data from EMOP in conceptual of moisture flow at disposal trenches to improve flux calculations. Meeting these objectives will provide the information necessary to determine compliance with the requirements of the E-Area Performance Assessment and protect groundwater resources
INDEPENDENT REVIEW OF THE X-701B GROUNDWATER REMEDY, PORTSMOUTH, OHIO: TECHNICAL EVALUATION AND RECOMMENDATIONS
The Department of Energy Portsmouth Paducah Project Office requested assistance from Department of Energy Office of Environmental Management (EM-22) to provide independent technical experts to evaluate past and ongoing remedial activities at the Portsmouth facility that were completed to address TCE contamination associated with the X-701B groundwater plume and to make recommendations for future efforts. The Independent Technical Review team was provided with a detailed and specific charter. The charter requested that the technical team first review the past and current activities completed for the X-701B groundwater remedy for trichloroethene (TCE) in accordance with a Decision Document that was issued by Ohio EPA on December 8, 2003 and a Work Plan that was approved by Ohio EPA on September 22, 2006. The remedy for X-701B divides the activities into four phases: Phase I - Initial Source Area Treatment, Phase II - Expanded Source Area Treatment, Phase III - Evaluation and Reporting, and Phase IV - Downgradient Remediation and Confirmation of Source Area Treatment. Phase I of the remedy was completed during FY2006, and DOE has now completed six oxidant injection events within Phase II. The Independent Technical Review team was asked to evaluate Phase II activities, including soil and groundwater results, and to determine whether or not the criteria that were defined in the Work Plan for the Phase II end point had been met. The following criteria are defined in the Work Plan as an acceptable Phase II end point: (1) Groundwater samples from the identified source area monitoring wells have concentrations below the Preliminary Remediation Goal (PRG) for TCE in groundwater, or (2) The remedy is no longer effective in removing TCE mass from the source area. In addition, the charter specifies that if the Review Team determines that the Phase II endpoint has not been reached, then the team should address the following issues: (1) If additional injection events are recommended, the team should identify the type of injection and target soil horizon for these injections; (2) Consider the feasibility of declaring Technical Impracticability and proceeding with the RCRA Cap for the X-701B; and (3) Provide a summary of other cost-effective technologies that could be implemented (especially for the lower Gallia). The Independent Technical Review team focused its evaluation solely on the X-701B source zone and contaminant plume. It did not review current or planned remedial activities at other plumes, waste areas, or landfills at the Portsmouth site, nor did it attempt to integrate such activities into its recommendations for X-701B. However, the ultimate selection of a remedy for X-701B by site personnel and regulators should take into account potentially synergistic efforts at other waste areas. Assessment of remedial alternatives in the context of site-wide management practices may reveal opportunities for leveraging and savings that would not otherwise be identified. For example, the cost of source-zone excavation or construction of a permeable reactive barrier at X-701B might be substantially reduced if contaminated soil could be buried on site at an existing or planned landfill. This allowance would improve the feasibility and competitiveness of both remedies. A comprehensive examination of ongoing and future environmental activities across the Portsmouth Gaseous Diffusion Plant is necessary to optimize the selection and timing of X-701B remediation with respect to cleanup efficiency, safety, and economics. A selected group of technical experts attended the technical workshop at the Portsmouth Gaseous Diffusion Plant from November 18 through 21, 2008. During the first day of the workshop, both contractor and DOE site personnel briefed the workshop participants and took them on a tour of the X-701B site. The initial briefing was attended by representatives of Ohio EPA who participated in the discussions. On subsequent days, the team reviewed baseline data and reports, were provided additional technical information from site personnel, evaluated work plans, determined critical issues and uncertainties, and recommended alternatives. This report documents the findings and recommendations of the independent technical review team
Ending poverty in Mongolia: From socialism to social development
While recent literature on social welfare has included Asian countries, less is known about low-income and former socialist countries in Central Asia. This article combines a documentary-historical method with a value-critical approach to analyze Mongolia’s social policy response to poverty. Mongolia is unique in Asia because it transformed from nomadic pastoralism to socialism without a phase of capitalist industrial development. The case study found that Mongolia lost social welfare when it transitioned from socialism, a statist model, to market liberalism and multiparty democracy. In the 21st century, Mongolia has been aspiring to promote social development by redirecting mining revenues to a human development fund. Mongolia is potentially an exemplar of social development strategies affirmed at the United Nations Conference for Sustainable Development (Rio+20) regarding a green economy for inclusive growth and poverty elimination. Future social welfare research should consider the importance of sustainability.
Key Practitioner Message: Global standards for tracking poverty alleviation will be integrated with sustainability measures beginning in 2015. Mongolia hopes to foster social development and sustainable livelihoods by reinvesting revenues from mining into human capital and health care. To sustain future generations, social policy needs to consider the relationship between natural capital, social capital, and financial capital
Reversal of Long-Term Trends in Ethane Identified from the Global Atmosphere Watch Reactive Gases Measurement Network
Reactive gases play an important role in climate and air pollution issues. They control the self-cleansing capability of the troposphere, contribute to air pollution and acid deposition, regulate the lifetimes and provide tracers for deciphering sources and sinks for greenhouse gases. Within GAW, the focus is placed on long-term, high-quality observations of ozone (O3), carbon monoxide (CO), volatile organic compounds (VOC), nitrogen oxides (NOx), and sulfur dioxide (SO2). More than 100 stations worldwide carry out reactive gases measurements with data reported to two World Data Centers. The reactive gases program in GAW cooperates The WMO GAW Reactive Gases Program with regional networks and other global monitoring initiatives in order to attain a complete picture of the tropospheric chemical composition. Observations are being made by in-situ monitoring, measurements from commercial routine air-crafts (e.g. IAGOS), column observations, and from flask sampling networks. Quality control and coordination of measurements between participating stations are a primary emphasis. GAW reactive gases data in rapid delivery mode are used to evaluate operational atmospheric composition forecasts in the EU Copernicus Atmospheric Monitoring Service. Oversight of the program is provided by GAW-WMO coordinated Reactive Gases Scientific Advisory Committee (RG-SAG)
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Determining Contaminant Distribution and Migration by Integrating Data from Multiple Cone Penetrometer-Based Tools
The cone penetrometer has been used for geologic characterization at the U.S. Department of Energy-owned Savannah River Site for the past seven years
Polluted Money, Polluted Wealth:Emerging Regimes of Value in the Mongolian Gold Mines
In Mongolia's gold rush economy, money has become such an emphatically localized and contentious object that its cash value cannot be presumed. Drawing on Mongolian notions of "polluted money," I argue that, in this context, cash value is determined not only by a banknote's status as legal tender but also by local understandings of its materiality. Confronted with the intense pollution that attaches to gold miners' money, shopkeepers change the face value of the money and effectively set higher prices in a region with increasing numbers of dependent customers. Rather than challenging or subverting money's national indexicality, this redenomination of state currency reflects people's critical position within a troubled economy of pollution. This case demonstrates that currency, like any other object, is a social medium that is intimately tied to the physical and cosmological world.PostprintPeer reviewe
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