Search Results

Role of fly ash in heavy metal removal from flue gas. Final report, September 1, 1994--February 29, 1996

Description: The work is mainly focused towards investigating the sorption phenomena of a representative chalcophile, arsenic (As) species, on fly ashes at temperatures representative of the upper-furnace region (850 -1200{degrees}C) and the economizer section (375-600{degrees}C). Arsenic is chosen because it is a highly toxic chalcophile and shows some affinity for fly ash but is also emitted from the stack as vapor and aerosol particles. Based on the preliminary thermodynamic analyses it was determined that under the temperature ranges of interest (400- 600{degrees}C and 800-1000{degrees}C) arsenic trioxide (As{sub 2}O{sub 3}) is the main arsenic species in the flue gas environment. The two temperature zones have been chosen because most of the dry-sorbent injection technologies are being developed for application in these two regions. Also various fly ash samples from different sources are being studied because their chemical composition and subsequently their chemical sorption characteristics would show a great deal of variation depending on their source. Studies were also conducted with calcium hydroxide as the chosen representative dry sorbent. This served as comparative studies between fly ash and dry sorbents. This will enable us to predict the behavior of arsenic when exposed to both fly ash and sorbent which is the case under actual boiler conditions. Experimental results show that Ca(OH){sub 2} captures significant amounts of arsenic species. To gain further insight into the capturing mechanism of calcium hydroxide experiments were performed at various temperatures and exposure times.
Date: October 1, 1996
Creator: Bavarian, F.; Mahuli, S.; Ghosh-Dastidar, A.; Agnihotri, R. & Fan, Liang-Shih
Partner: UNT Libraries Government Documents Department

Corrective Action Decision Document for Corrective Action Unit 428: Area 3 Septic Waste Systems 1 and 5, Tonopah Test Range, Nevada

Description: This Corrective Action Decision Document identifies and rationalizes the US Department of Energy, Nevada Operations Office's selection of a recommended corrective action alternative (CAA) appropriate to facilitate the closure of Corrective Action Unit (CAU) 428, Septic Waste Systems 1 and 5, under the Federal Facility Agreement and Consent Order. Located in Area 3 at the Tonopah Test Range (TTR) in Nevada, CAU 428 is comprised of two Corrective Action Sites (CASs): (1) CAS 03-05-002-SW01, Septic Waste System 1 and (2) CAS 03-05-002- SW05, Septic Waste System 5. A corrective action investigation performed in 1999 detected analyte concentrations that exceeded preliminary action levels; specifically, contaminants of concern (COCs) included benzo(a) pyrene in a septic tank integrity sample associated with Septic Tank 33-1A of Septic Waste System 1, and arsenic in a soil sample associated with Septic Waste System 5. During this investigation, three Corrective Action Objectives (CAOs) were identified to prevent or mitigate exposure to contents of the septic tanks and distribution box, to subsurface soil containing COCs, and the spread of COCs beyond the CAU. Based on these CAOs, a review of existing data, future use, and current operations in Area 3 of the TTR, three CAAs were developed for consideration: Alternative 1 - No Further Action; Alternative 2 - Closure in Place with Administrative Controls; and Alternative 3 - Clean Closure by Excavation and Disposal. These alternatives were evaluated based on four general corrective action standards and five remedy selection decision factors. Based on the results of the evaluation, the preferred CAA was Alternative 3. This alternative meets all applicable state and federal regulations for closure of the site and will eliminate potential future exposure pathways to the contaminated soils at the Area 3 Septic Waste Systems 1 and 5.
Date: February 8, 2000
Creator: U.S. Department of Energy, Nevada Operations Office
Partner: UNT Libraries Government Documents Department

Role of fly ash in heavy metal removal from flue gas. Final report, September 1, 1993--August 31, 1994

Description: The primary objective of this work is to study the fundamental phenomena involved in the sorption of trace chalcophilic elements by fly ash at high and medium temperatures. Chalcophiles are the low-boiling trace elements that are volatilized during pulverized coal combustion and are transferred to the gas phase, e.g., As, Pb, Cd and Se. The main focus of this work is investigating the sorption phenomena of a representative chalcophile, arsenic (As) on fly ashes at temperatures representative of the upper-furnace region (850--1200{degree}C) and the economizer section (375--600{degree}C). Arsenic is chosen because it is a highly toxic chalcophile and shows some affinity for fly ash but is also emitted from the stack as vapor and aerosol particles. The two temperature zones have been chosen because most of the dry-sorbent injection technologies are being developed for application in these two regions. Also, various fly ash samples from different sources are being studied because their chemical composition and subsequently their chemical sorption characteristics would show a great deal of variation depending on their source. In the first year of this project, it was proposed to conduct isothermal sorption experiments in a differential reactor system. The first year`s work was divided into two phases; namely (1) design, construction, testing and trouble-shooting of the differential reactor assembly and the analytical instrumentation, and, (2) designing experiments and conducting sorption studies in the differential reactor system.
Date: February 1, 1995
Creator: Bavarian, F.; Mahuli, S.; Ghosh-Dastidar, A.; Agnihotri, R. & Fan, L.S.
Partner: UNT Libraries Government Documents Department

Ohio Coal Research Consortium fourth year final summary report, September 1, 1993--August 31, 1994

Description: As a part of its efforts to improve the use of high-sulfur Ohio coal within environmental limits, the Ohio Coal Development Office, an entity within the Ohio Department of Development (OCDO/ODOD), in late 1988 established a consortium of four Ohio universities. The purpose of the Ohio Coal Research Consortium is to conduct a multi-year fundamental research program focused on (1) the enhancement or development of dry sorption processes for the economical removal of high levels of SO{sub 2} and other pollutants and (2) an increased understanding of methods for reduction in air toxics emissions from combustion gases produced by burning high-sulfur Ohio coal. This report contains summaries of twelve studies in these areas.
Date: May 1, 1995
Partner: UNT Libraries Government Documents Department

Environmental Assessment and Finding of No Significant Impact: Waste Remediation Activities at Elk Hills (Former Naval petroleum Reserve No. 1), Kern County, California

Description: DOE proposes to conduct a variety of post-sale site remediation activities, such as characterization, assessment, clean-up, and formal closure, at a number of inactive waste sites located at Elk Hills. The proposed post-sale site remediation activities, which would be conducted primarily in developed portions of the oil field, currently are expected to include clean-up of three basic categories of waste sites: (1) nonhazardous solid waste surface trash scatters, (2) produced wastewater sumps, and (3) small solid waste landfills. Additionally, a limited number of other inactive waste sites, which cannot be typified under any of these three categories, have been identified as requiring remediation. Table 2.1-1 presents a summary, organized by waste site category, of the inactive waste sites that require remediation per the PSA, the ASA, and/or the UPCTA. The majority of these sites are known to contain no hazardous waste. However, one of the surface scatter sites (2G) contains an area of burn ash with hazardous levels of lead and zinc, another surface scatter site (25S) contains an area with hazardous levels of lead, a produced wastewater sump site (23S) and a landfill (42-36S) are known to contain hazardous levels of arsenic, and some sites have not yet been characterized. Furthermore, additional types of sites could be discovered. For example, given the nature of oil field operations, sites resulting from either spills or leaks of hazardous materials could be discovered. Given the nature of the agreements entered into by DOE regarding the required post-sale clean-up of the inactive waste sites at Elk Hills, the Proposed Action is the primary course of action considered in this EA. The obligatory remediation activities included in the Proposed Action are standard procedures such that possible variations of the Proposed Action would not vary substantially enough to require designation as a separate, reasonable alternative. ...
Date: December 17, 1999
Creator: /A, N
Partner: UNT Libraries Government Documents Department

On mobilization of lead and arsenic in groundwater in response to CO2 leakage from deep geological storage

Description: If carbon dioxide stored in deep saline aquifers were to leak into an overlying aquifer containing potable groundwater, the intruding CO{sub 2} would change the geochemical conditions and cause secondary effects mainly induced by changes in pH In particular, hazardous trace elements such as lead and arsenic, which are present in the aquifer host rock, could be mobilized. In an effort to evaluate the potential risks to potable water quality, reactive transport simulations were conducted to evaluate to what extent and mechanisms through which lead and arsenic might be mobilized by intrusion of CO{sub 2}. An earlier geochemical evaluation of more than 38,000 groundwater quality analyses from aquifers throughout the United States and an associated literature review provided the basis for setting up a reactive transport model and examining its sensitivity to model variation. The evaluation included identification of potential mineral hosts containing hazardous trace elements, characterization of the modal bulk mineralogy for an arenaceous aquifer, and augmentation of the required thermodynamic data. The reactive transport simulations suggest that CO{sub 2} ingress into a shallow aquifer can mobilize significant lead and arsenic, contaminating the groundwater near the location of intrusion and further downstream. Although substantial increases in aqueous concentrations are predicted compared to the background values, the maximum permitted concentration for arsenic in drinking water was exceeded in only a few cases, whereas that for lead was never exceeded.
Date: July 1, 2009
Creator: Zheng, L.; Apps, J.A.; Zhang, Y.; Xu, T. & Birkholzer, J.T.
Partner: UNT Libraries Government Documents Department

Bird Surveys at DARHT Before and During Operations: Comparison of Species Abundance and Composition and Trace Element Uptake

Description: The Dual-Axis Radiographic Hydrodynamic Test (DARHT) Facility Mitigation Action Plan specifies the comparison of baseline conditions in biotic and abiotic media with those collected after operations have started. Operations at DARHT at Los Alamos National Laboratory started in 2000. In this study, the abundance and composition of birds collected near the DARHT facility from 2003 through 2006 were determined and compared to a preoperational period (1999). In addition, the levels of radionuclides and other inorganic chemicals in birds were compared to regional statistical reference levels (RSRLs). The number and diversity of bird species generally increased over preoperational levels with the greatest number of birds (412) and species (46) occurring in 2005. The most common bird species collected regardless of time periods were the chipping sparrow (Spizella passerina), the Virginia's warbler (Vermivora virginiae), the western bluebird (Sialia mexicana), the broad-tailed hummingbird (Selasphorus platycercus), the sage sparrow (Amphispiza belli), and the western tanager (Piranga ludoviciana). Most radionuclides, with the exception of uranium-234 and uranium-238, in (whole body) birds collected after operations began were either not detected or below RSRLs. Uranium-234 and uranium-238 concentrations in a few samples were far below screening levels and do not pose a potential unacceptable dose to the birds. In contrast, many inorganic chemicals, particularly arsenic and silver, in birds collected before and after operations began were in higher concentrations than RSRLs. Because birds (skin plus feathers) collected in the years before operations began contained higher levels of arsenic and silver than RSRLs and because there was no evidence of these metals in soil and sediment directly around the DARHT facility, the elevated levels of these metals in birds during early operations are probably not related to DARHT operations. Arsenic and silver in birds, however, have decreased over time to near background levels in 2007.
Date: November 30, 2007
Creator: P. R. Fresquez, D. C. Keller, C. D. Hathcock
Partner: UNT Libraries Government Documents Department

EFFECT OF ADDITIONS TO ZIRCALOY ON HYDROGEN PICKUP DURING AQUEOUS CORROSION

Description: An investigation was conducted into the possibility of alloy additions to Zircaloy-2 to diminish hydrogen absorption during aqueous corrosion. The nickel in Zircaloy-2 is believed to be the major constituent responsible for the relatively high hydrogen absorption. Additions of up to 0.5 wt.% antimony, arsenic, bismuth, or tellurium were selected on the basis of their known ability to poison the catalytic effects of nickel in hydrogenation reactions of other systems. Results of tests conducted for a total of 224 days in 600 and 680 deg F water and 750 deg F steam revealed no decrease in hydrogen absorption in modified Zircaloy-2 containing the aforementioned alloy additions. Hydrogen absorption increased when these alloying elements were present in the range of 0.1 to 0.2 wt.%. Corrosion resistance also decreased with alloy additions in these ranges. A 2-atm. partial pressure of hydrogen in the steam or above the water did not affect hydrogen absorption in the alloys appreciably. The hydrogen partial pressure did not affect time to transition in corrosion rates, but did appear to produce higher weight gains than degassed water. (auth)
Date: December 29, 1959
Creator: Berry, W.E.; White, E.L. & Fink, F.W.
Partner: UNT Libraries Government Documents Department

Anionic sorbents for arsenic and technetium species.

Description: Two sorbents, zirconium coated zeolite and magnesium hydroxide, were tested for their effectiveness in removing arsenic from Albuquerque municipal water. Results for the zirconium coated zeolite indicate that phosphate present in the water interfered with the sorption of arsenic. Additionally, there was a large quantity of iron and copper present in the water, corrosion products from the piping system, which may have interfered with the uptake of arsenic by the sorbent. Magnesium hydroxide has also been proven to be a strong sorbent for arsenic as well as other metals. Carbonate, present in water, has been shown to interfere with the sorption of arsenic by reacting with the magnesium hydroxide to form magnesium carbonate. The reaction mechanism was investigated by FT-IR and shows that hydrogen bonding between an oxygen on the arsenic species and a hydrogen on the Mg(OH)2 is most likely the mechanism of sorption. This was also confirmed by RAMAN spectroscopy and XRD. Technetium exists in multiple oxidation states (IV and VII) and is easily oxidized from the relatively insoluble Tc(IV) form to the highly water soluble and mobile Tc(VII) form. The two oxidation states exhibit different sorption characteristics. Tc(VII) does not sorb to most materials whereas Tc(IV) will strongly sorb to many materials. Therefore, it was determined that it is necessary to first reduce the Tc (using SnCl2) before sorption to stabilize Tc in the environment. Additionally, the effect of carbonate and phosphate on the sorption of technetium by hydroxyapatite was studied and indicated that both have a significant effect on reducing Tc sorption.
Date: September 1, 2003
Creator: Lucero, Daniel A.; Moore, Robert Charles; Bontchev, Ranko Panayotov; Hasan, Ahmed Ali Mohamed; Zhao, Hongting; Salas, Fred Manuel et al.
Partner: UNT Libraries Government Documents Department

Biological Sampling and Analysis in Sinclair and Dyes Inlets, Washington: Chemical Analyses for 2007 Puget Sound Biota Study

Description: Evaluating spatial and temporal trends in contaminant residues in Puget Sound fish and macroinvertebrates are the objectives of the Puget Sound Ambient Monitoring Program (PSAMP). In a cooperative effort between the ENVironmental inVESTment group (ENVVEST) and Washington State Department of Fish and Wildlife, additional biota samples were collected during the 2007 PSAMP biota survey and analyzed for chemical residues and stable isotopes of carbon (δ13C) and nitrogen (δ15N). Approximately three specimens of each species collected from Sinclair Inlet, Georgia Basin, and reference locations in Puget Sound were selected for whole body chemical analysis. The muscle tissue of specimens selected for chemical analyses were also analyzed for δ13C and δ15N to provide information on relative trophic level and food sources. This data report summarizes the chemical residues for the 2007 PSAMP fish and macro-invertebrate samples. In addition, six Spiny Dogfish (Squalus acanthias) samples were necropsied to evaluate chemical residue of various parts of the fish (digestive tract, liver, embryo, muscle tissue), as well as, a weight proportional whole body composite (WBWC). Whole organisms were homogenized and analyzed for silver, arsenic, cadmium, chromium, copper, nickel, lead, zinc, mercury, 19 polychlorinated biphenyl (PCB) congeners, PCB homologues, percent moisture, percent lipids, δ13C, and δ15N.
Date: October 9, 2008
Creator: Brandenberger, Jill M.; Suslick, Carolynn R. & Johnston, Robert K.
Partner: UNT Libraries Government Documents Department

Evaluation of the Emission, Transport, and Deposition of Mercury, Fine Particulate Matter, and Arsenic from Coal-Based Power Plants in the Ohio River Valley Region

Description: As stated in the proposal: Ohio University, in collaboration with CONSOL Energy, Advanced Technology Systems, Inc (ATS) and Atmospheric and Environmental Research, Inc. (AER) as subcontractors, is evaluating the impact of emissions from coal-fired power plants in the Ohio River Valley region as they relate to the transport and deposition of mercury, arsenic, and associated fine particulate matter. This evaluation will involve two interrelated areas of effort: ambient air monitoring and regional-scale modeling analysis. The scope of work for the ambient air monitoring will include the deployment of a surface air monitoring (SAM) station in southeastern Ohio. The SAM station will contain sampling equipment to collect and measure mercury (including speciated forms of mercury and wet and dry deposited mercury), arsenic, particulate matter (PM) mass, PM composition, and gaseous criteria pollutants (CO, NO{sub x}, SO{sub 2}, O{sub 3}, etc.). Laboratory analysis of time-integrated samples will be used to obtain chemical speciation of ambient PM composition and mercury in precipitation. Near-real-time measurements will be used to measure the ambient concentrations of PM mass and all gaseous species including Hg0 and RGM. Approximately 18 months of field data will be collected at the SAM site to validate the proposed regional model simulations for episodic and seasonal model runs. The ambient air quality data will also provide mercury, arsenic, and fine particulate matter data that can be used by Ohio Valley industries to assess performance on multi-pollutant control systems. The scope of work for the modeling analysis will include (1) development of updated inventories of mercury and arsenic emissions from coal plants and other important sources in the modeled domain; (2) adapting an existing 3-D atmospheric chemical transport model to incorporate recent advancements in the understanding of mercury transformations in the atmosphere; (3) analyses of the flux of Hg{sup 0}, RGM, arsenic, and ...
Date: April 2, 2006
Creator: Crist, Kevin
Partner: UNT Libraries Government Documents Department

Evaluation of the Emission, Transport, and Deposition of Mercury, Fine Particulate Matter, and Arsenic from Coal-Based Power Plants in the Ohio River Valley Region

Description: Ohio University, in collaboration with CONSOL Energy, Advanced Technology Systems, Inc (ATS) and Atmospheric and Environmental Research, Inc. (AER) as subcontractors, is evaluating the impact of emissions from coal-fired power plants in the Ohio River Valley region as they relate to the transport and deposition of mercury, arsenic, and associated fine particulate matter. This evaluation will involve two interrelated areas of effort: ambient air monitoring and regional-scale modeling analysis. The scope of work for the ambient air monitoring will include the deployment of a surface air monitoring (SAM) station in southeastern Ohio. The SAM station will contain sampling equipment to collect and measure mercury (including speciated forms of mercury and wet and dry deposited mercury), arsenic, particulate matter (PM) mass, PM composition, and gaseous criteria pollutants (CO, NOx, SO{sub 2}, O{sub 3}, etc.). Laboratory analysis of time-integrated samples will be used to obtain chemical speciation of ambient PM composition and mercury in precipitation. Near-real-time measurements will be used to measure the ambient concentrations of PM mass and all gaseous species including Hg{sup 0} and RGM. Approximately of 18 months of field data will be collected at the SAM site to validate the proposed regional model simulations for episodic and seasonal model runs. The ambient air quality data will also provide mercury, arsenic, and fine particulate matter data that can be used by Ohio Valley industries to assess performance on multi-pollutant control systems. The scope of work for the modeling analysis will include (1) development of updated inventories of mercury and arsenic emissions from coal plants and other important sources in the modeled domain; (2) adapting an existing 3-D atmospheric chemical transport model to incorporate recent advancements in the understanding of mercury transformations in the atmosphere; (3) analyses of the flux of Hg0, RGM, arsenic, and fine particulate matter in the ...
Date: October 2, 2005
Creator: Crist, Kevin
Partner: UNT Libraries Government Documents Department

Response to Comments on "A Bacterium That Can Grow Using Arsenic Instead of Phosphorus"

Description: Concerns have been raised about our recent study describing a bacterium that can grow using arsenic (As) instead of phosphorus (P). Our data suggested that As could act as a substitute for P in major biomolecules in this organism. Although the issues raised are of investigative interest, we contend that they do not invalidate our conclusions. We argue that while no single line of evidence we presented was sufficient to support our interpretation of the data, taken as an entire dataset we find no plausible alternative to our conclusions. Here we reply to the critiques and provide additional arguments supporting the assessment of the data we reported.
Date: March 7, 2011
Creator: Wolfe-Simon, F; Blum, J S; Kulp, T R; Gordon, G W; Hoeft, S E; Pett-Ridge, J et al.
Partner: UNT Libraries Government Documents Department

Speciation and Attenuation of Arsenic and Selenium at Coal Combustion By-Product Management Facilities

Description: Following completion of contracting activities, sites were identified for the field leachate characterization study. Sampling and Analyses Plans (SAPs) and Site Access Agreements (SAAs) were developed for each site. A total of ten sites were sampled during this reporting period. Among the trace constituents, boron, silicon, and strontium were present in highest concentrations, with median values above 1 mg/L (1,000 {micro}g/L). Work on the first of three sites for the detailed arsenic and selenium adsorption studies began in 2002, prior to completion of the final DOE award. Kd values ranged from 100 to 12,000 L/kg for arsenic (V), 15 to 160 L.kg for As(III), and 5 to 25 L/kg for Se(VI).
Date: October 18, 2005
Creator: Ladwig, K.; Hensel, B.; Wallschlager, D.; Lee, L. & Murarka, I.
Partner: UNT Libraries Government Documents Department

Speciation and Attenuation of Arsenic and Selenium at Coal Combustion By-Product Management Facilities

Description: Field leachate samples are being collected from coal combustion product (CCP) management sites from several geographic locations in the United States to provide broad characterization of major and trace constituents in the leachate. In addition, speciation of arsenic, selenium, chromium, and mercury in the leachates is being determined. Through 2003, 35 samples were collected at 14 sites representing a variety of CCP types, management approaches, and source coals. Samples have been collected from leachate wells, leachate collection systems, drive-point piezometers, lysimeters, the ash/water interface at impoundments, impoundment outfalls and inlets, and seeps. Additional sampling at 23 sites has been conducted in 2004 or is planned for 2005. First-year results suggest distinct differences in the chemical composition of leachate from landfills and impoundments, and from bituminous and subbituminous coals. Concentrations of most constituents were generally higher in landfill leachate than in impoundment leachate. Sulfate, sodium, aluminum, molybdenum, vanadium, cadmium, mercury and selenium concentrations were higher in leachates for ash from subbituminous source coal. Calcium, boron, lithium, strontium, arsenic, antimony, and nickel were higher for ash from bituminous source coal. These variations will be explored in more detail when additional data from the 2004 and 2005 samples become available.
Date: October 19, 2005
Creator: Ladwig, K.; Hensel, B.; Wallschlager, D.; Lee, L. & Murarka, I
Partner: UNT Libraries Government Documents Department

Speciation and Attenuation of Arsenic and Selenium at Coal Combustion By-Product Management Facilities

Description: The overall objective of this project was to evaluate the impact of key constituents captured from power plant air streams (principally arsenic and selenium) on the disposal and utilization of coal combustion products (CCPs). Specific objectives of the project were: (1) to develop a comprehensive database of field leachate concentrations at a wide range of CCP management sites, including speciation of arsenic and selenium, and low-detection limit analyses for mercury; (2) to perform detailed evaluations of the release and attenuation of arsenic species at three CCP sites; and (3) to perform detailed evaluations of the release and attenuation of selenium species at three CCP sites. Each of these objectives was accomplished using a combination of field sampling and laboratory analysis and experimentation. All of the methods used and results obtained are contained in this report. For ease of use, the report is subdivided into three parts. Volume 1 contains methods and results for the field leachate characterization. Volume 2 contains methods and results for arsenic adsorption. Volume 3 contains methods and results for selenium adsorption.
Date: December 31, 2005
Creator: Ladwig, K.
Partner: UNT Libraries Government Documents Department

Specifically Designed Constructed Wetlands: A Novel Treatment Approach for Scrubber Wastewater

Description: A pilot-scale wetland treatment system was specifically designed and constructed at Clemson University to evaluate removal of mercury, selenium, and other constituents from flue gas desulfurization (FGD) wastewater. Specific objectives of this research were: (1) to measure performance of a pilot-scale constructed wetland treatment system in terms of decreases in targeted constituents (Hg, Se and As) in the FGD wastewater from inflow to outflow; (2) to determine how the observed performance is achieved (both reactions and rates); and (3) to measure performance in terms of decreased bioavailability of these elements (i.e. toxicity of sediments in constructed wetlands and toxicity of outflow waters from the treatment system). Performance of the pilot-scale constructed wetland treatment systems was assessed using two criteria: anticipated NPDES permit levels and toxicity evaluations using two sentinel toxicity-testing organisms (Ceriodaphnia dubia and Pimephales promelas). These systems performed efficiently with varied inflow simulations of FGD wastewaters removing As, Hg, and Se concentrations below NPDES permit levels and reducing the toxicity of simulated FGD wastewater after treatment with the constructed wetland treatment systems. Sequential extraction procedures indicated that these elements (As, Hg, and Se) were bound to residual phases within sediments of these systems, which should limit their bioavailability to aquatic biota. Sediments collected from constructed wetland treatment systems were tested to observe toxicity to Hyalella azteca or Chironomus tetans. Complete survival (100%) was observed for H. azteca in all cells of the constructed wetland treatment system and C. tentans had an average of 91% survival over the three treatment cells containing sediments. Survival and growth of H. azteca and C. tentans did not differ significantly between sediments from the constructed wetland treatment system and controls. Since the sediments of the constructed wetland treatment system are repositories for As, Hg, and Se and the bioavailability of these elements decreased after ...
Date: September 1, 2005
Creator: Jr, John H. Rodgers; Castle, James W.; Eggert, Chris Arrington: Derek & Iannacone, Meg
Partner: UNT Libraries Government Documents Department

Neutron Induced Cross Sections for Radiochemistry for Isotopes of Arsenic

Description: We have developed a set of modeled nuclear reaction cross sections for use in radiochemical diagnostics. Local systematics for the input parameters required by the Hauser-Feshbach statistical model were developed and used to calculate neutron induced nuclear reaction cross sections for isotopes of Arsenic (Z = 33) in the mass range 71 {le} A {le} 77.
Date: January 10, 2006
Creator: Kelley, K; Hoffman, R D; Dietrich, F S & Mustafa, M
Partner: UNT Libraries Government Documents Department

Novel Adsorbent-Reactants for Treatment of Ash and Scrubber Pond Effluents

Description: The overall goal of this project was to evaluate the ability of novel adsorbent/reactants to remove specific toxic target chemicals from ash and scrubber pond effluents while producing stable residuals for ultimate disposal. The target chemicals studied were arsenic (As(III) and As(V)), mercury (Hg(II)) and selenium (Se(IV) and Se(VI)). The adsorbent/reactants that were evaluated are iron sulfide (FeS) and pyrite (FeS{sub 2}). Procedures for measuring concentrations of target compounds and characterizing the surfaces of adsorbent-reactants were developed. Effects of contact time, pH (7, 8, 9, 10) and sulfate concentration (0, 1, 10 mM) on removal of all target compounds on both adsorbent-reactants were determined. Stability tests were conducted to evaluate the extent to which target compounds were released from the adsorbent-reactants when pH changed. Surface characterization was conducted with x-ray photoelectron spectroscopy (XPS) to identify reactions occurring on the surface between the target compounds and surface iron and sulfur. Results indicated that target compounds could be removed by FeS{sub 2} and FeS and that removal was affected by time, pH and surface reactions. Stability of residuals was generally good and appeared to be affected by the extent of surface reactions. Synthesized pyrite and mackinawite appear to have the required characteristics for removing the target compounds from wastewaters from ash ponds and scrubber ponds and producing stable residuals.
Date: January 31, 2010
Creator: Batchelor, Bill; Han, Dong Suk & Kim, Eun Jung
Partner: UNT Libraries Government Documents Department

Novel Anionic Clay Adsorbents for Boiler-Blow Down Waters Reclaim and Reuse

Description: Our goal in this study is to utilize novel anionic clay sorbents for treating and reclaiming/reusing power-plant effluents, in particular, boiler blow-down waters containing heavy metals, such as As and Se. Developing and using novel materials for such application is dictated by the challenge posed by reclaiming and recycling these too-clean-to-clean effluent streams, generated during electricity production, whose contaminant levels are in the ppm/ppb (or even less) trace levels. During the study model blow-down streams have been treated in batch experiments. Adsorption isotherms as a function of pH/temperature have been established for both As and Se. Adsorption rates have also measured as a function of concentration, temperature, pH, and space time. For both the equilibrium and rate measurements, we have studied the As/Se interaction, and competition from background anions. A homogeneous surface diffusion model is used to describe the experimental kinetic data. The estimated diffusivity values are shown to depend on the particle size. On the other hand, a model taking into account the polycrystalline nature of these adsorbent particles, and the presence of an intercrystallite porous region predicts correctly that the surface diffusivity is particle size independent. A mathematical model to describe flow experiments in packed-beds has also been developed during phase I of this project. The goal is to validate this model with flow experiments in packed-beds during the phase II of this project, to determine the adsorption capacity under flow conditions, and to compare it with the capacity estimated from the adsorption isotherms determined from the batch studies.
Date: December 1, 2005
Creator: Sahimi, Muhammad & Tsotsis, Theodore T.
Partner: UNT Libraries Government Documents Department

Synchrotron Radiation Photoemission Spectroscopic Study of Band Offsets and Interface Self-cleaning by Atomic Layer Deposited HfO2 on In0.53Ga0.47As and In0.52Al0.48As

Description: The Synchrotron Radiation Photoemission Spectroscopic (SRPES) study was conducted to (a) investigate the surface chemistry of In{sub 0.53}Ga{sub 0.47}As and In{sub 0.52}Al{sub 0.48}As post chemical and thermal treatments, (b) construct band diagram and (c) investigate the interface property of HfO{sub 2}/In{sub 0.53}Ga{sub 0.47}As and HfO{sub 2}/In{sub 0.52}Al{sub 0.48}As. Dilute HCl and HF etch remove native oxides on In{sub 0.53}Ga{sub 0.47}As and In{sub 0.52}Al{sub 0.47}As, whereas in-situ vacuum annealing removes surface arsenic pile-up. After the atomic layer deposition of HfO{sub 2}, native oxides were considerably reduced compared to that in as-received epi-layers, strongly suggesting the self-clean mechanism. Valence and conduction band offsets are measured to be 3.37 {+-} 0.1eV, 1.80 {+-} 0.3eV for In{sub 0.53}Ga{sub 0.47}As and 3.00 {+-} 0.1eV, 1.47 {+-} 0.3eV for In{sub 0.52}Al{sub 0.47}As, respectively.
Date: October 31, 2008
Creator: Kobayashi, Masaharu; /SLAC, SSRL; Chen, P.T.; Sun, Y.; Goel, N.; Majhi, P. et al.
Partner: UNT Libraries Government Documents Department

SALTSTONE 1QCY11 TCLP RESULTS

Description: A Saltstone waste form was prepared in the Savannah River National Laboratory (SRNL) from a Tank 50H sample and Z-Area premix material for the first quarter of calendar year 2011 (1QCY11). After the prescribed 28 day cure, samples of the saltstone were collected, and the waste form was shown to meet the South Carolina Hazardous Waste Management Regulations (SCHWMR) R.61-79.261.24 and R.61-79.268.48(a) requirements for a nonhazardous waste form with respect to RCRA metals and underlying hazardous constituents. These analyses met all quality assurance specifications of USEPA SW-846. The Saltstone Production Facility (SPF) receives waste from Tank 50H for treatment. In the first quarter of the 2011 calendar year (1QCY11), Tank 50H accepted transfers of approximately 15 kgal from the Effluent Treatment Project (ETP), approximately 15 kgal from Tank 710 - the H-Canyon General Purpose Evaporator, approximately 73 kgal from the H-Canyon Super Kukla campaign, approximately 285 kgal from the Actinide Removal Process/Modular Caustic Side Solvent Extraction Unit (ARP/MCU) Decontaminated Salt Solution Hold Tank (DSS-HT), and approximately 21 kgal from other sources. The Saltstone Grout Sampling plan provides the South Carolina Department of Health and Environmental Control (SCDHEC) with the chemical and physical characterization strategy for the salt solution which is to be disposed of in the Z-Area Solid Waste Landfill (SWLF). During operation, samples were collected from Tank 50H and grout samples prepared to determine the non-hazardous nature of the grout to meet the requirements of the South Carolina Hazardous Waste Management Regulations (SCHWMR) R.61-79.261.24(b) and R.61-79.268.48(a). Savannah River National Laboratory (SRNL) was asked to prepare saltstone from samples of Tank 50H obtained January 5, 2011 during 1QCY11 to determine the non-hazardous nature of the grout. The samples were cured and shipped to Babcock & Wilcox Technical Services Group-Radioisotope and Analytical Chemistry Laboratory (B&W TSG-RACL) to perform the Toxic Characteristic ...
Date: May 16, 2011
Creator: Reigel, M.
Partner: UNT Libraries Government Documents Department

SALTSTONE 2QCY09 TCLP RESULTS

Description: A Saltstone waste form was prepared in the Savannah River National Laboratory from a Tank 50H sample and Z-Area premix material for the second quarter of calendar year 2009 (2QCY09). After the prescribed 28 day cure, samples of the saltstone were collected, and the waste form was shown to meet the South Carolina Hazardous Waste Management Regulations (SCHWMR) R.61-79.261.24 and R.61-79.268.48(a) requirements for a nonhazardous waste form with respect to RCRA metals and underlying hazardous constituents. These analyses met all quality assurance specifications of USEPA SW-846. The Saltstone Production Facility (SPF) receives waste from Tank 50H for treatment. In the second quarter of the 2009 calendar year (2QCY09), Tank 50 accepted transfers of approximately 32 kgal from the Effluent Treatment Project (ETP) waste, approximately 4 kgal from Tank 710 - the H-Canyon General Purpose Evaporator, approximately 156 kgal from the Modular Caustic Side Solvent Extraction Unit (MCU) Decontaminated Salt Solution Hold Tank (DSS-HT), and approximately 484 kgal from Tank 23. The Saltstone Grout Sampling plan provides the South Carolina Department of Health and Environmental Control (SCDHEC) with the chemical and physical characterization strategy for the salt solution which is to be disposed of in the Z-Area Solid Waste Landfill (ISWLF). During operation, samples were collected from Tank 50H and grout samples prepared to determine the non-hazardous nature of the grout to meet the requirements of the South Carolina Hazardous Waste Management Regulations (SCHWMR) R.61-79.261.24(b) and R.61-79.268.48(a). SRNL was asked to prepare saltstone from a sample of Tank 50H obtained May 20, 2009 during 2QCY09 to determine the non-hazardous nature of the grout. The samples were cured and shipped to Babcock & Wilcox Technical Services Group-Radioisotope and Analytical Chemistry Laboratory (B&WTSGRACL) to perform the Toxic Characteristic Leaching Procedure (TCLP) and subsequent extract analysis on saltstone samples for the analytes required for ...
Date: October 29, 2009
Creator: Reigel, M.
Partner: UNT Libraries Government Documents Department

SALTSTONE 2QCY11 TCLP RESULTS

Description: The Saltstone Production Facility (SPF) receives waste from Tank 50H for treatment. In the second quarter of the 2011 calendar year (2QCY11), Tank 50H accepted transfers of approximately 15 kgal from the Effluent Treatment Project (ETP), approximately 2 kgal from Tank 710 - the H-Canyon General Purpose Evaporator, approximately 63 kgal from the HCanyon Super Kukla campaign, approximately 370 kgal from the Actinide Removal Process/Modular Caustic Side Solvent Extraction Unit (ARP/MCU) Decontaminated Salt Solution Hold Tank (DSS-HT), and approximately 10 kgal from other sources. The Saltstone Grout Sampling plan provides the South Carolina Department of Health and Environmental Control (SCDHEC) with the chemical and physical characterization strategy for the salt solution which is to be disposed of in the Z-Area Solid Waste Landfill (SWLF). During operation, samples were collected from Tank 50H and grout samples prepared to determine the non-hazardous nature of the grout to meet the requirements of the South Carolina Hazardous Waste Management Regulations (SCHWMR) R.61-79.261.24(b) and R.61-79.268.48(a). Savannah River National Laboratory (SRNL) was asked to prepare saltstone from samples of Tank 50H obtained April 5, 2011 during 2QCY11 to determine the non-hazardous nature of the grout. The samples were cured and shipped to Babcock & Wilcox Technical Services Group-Radioisotope and Analytical Chemistry Laboratory (B&W TSG-RACL) to perform the Toxic Characteristic Leaching Procedure (TCLP) and subsequent extract analysis on saltstone samples for the analytes required for the quarterly analysis saltstone sample. In addition to the eight toxic metals - arsenic, barium, cadmium, chromium, mercury, lead, selenium and silver - analytes included the underlying hazardous constituents (UHC) antimony, beryllium, nickel, and thallium which could not be eliminated from analysis by process knowledge. B&W TSGRACL provided subsamples to GEL Laboratories, LLC for analysis for the UHCs benzene, phenols and total and amenable cyanide.
Date: July 28, 2011
Creator: Eibling, R.
Partner: UNT Libraries Government Documents Department