On morphology of methane-derived authigenic carbonates

Science.gov (United States)

Logvina, E.; Matveeva, T.

2009-04-01

Studies of methane-derived carbonates revealed a great variety their morphological types. Although the processes of these carbonates formation is not clearly understood, it has been suggested that in general bacterially mediated processes of hydrocarbon oxidation, coupled with sulphate reduction, produce unusually high levels of alkalinity and dissolved inorganic carbon in the pore fluids that is partitioned between the precipitating carbonate and CO2 rich plumes which emanate into the water column (Aharon, 1994). These carbonates consist by three main CaCO3 polymorphs - calcite, aragonite and dolomite. Carbonates with different petrography cemented from these polymorphs can be classified according to their specific locality mode of formation and biogenic or non-biogenic origin (Greinert et al., 2002). There are classifications for the authigenic carbonates which are based on petrography, morphology, or based on age and origin. In this work we will consider the petrographical and morphological differences of authigenic carbonates. The large structures vary from 10 to 200 m size, named as chemoherm carbonates. Usually they cemented by pure aragonite with minor Mg-calcite admixture. These chemoherms rise up to 50 m above the seafloor. The structures are irregular in shape and have numerous pores and open pathways resulting from plumbing system of fluid expulsion. This type of authigenic carbonates was observed in the NE Black Sea (Michaelis et al., 2002), at the Hydrate Ridge area (Greinert et al., 2001), at Aleutian accretionary margin (Greinert et al., 2002). Diagenetic carbonates - carbonate cemented sediments both growing at the seafloor or within the sediment framework and showing a large variety of shapes (chimneys, crusts, concretions est.), with grey to dark-grey color. Petrographically the carbonate cement represents by Mg-calcite, protodolomite and dolomite. The diagenetic carbonates occur widely in the fluid venting areas. In particular, diagenetic

The effects of trace element content on pyrite oxidation rates

Science.gov (United States)

Gregory, D. D.; Lyons, T.; Cliff, J. B.; Perea, D. E.; Johnson, A.; Romaniello, S. J.; Large, R. R.

2017-12-01

Pyrite acts as both an important source and sink for many different metals and metalloids in the environment, including many that are toxic. Oxidation of pyrite can release these elements while at the same time producing significant amounts of sulfuric acid. Such issues are common in the vicinity of abandoned mines and smelters, but, as pyrite is a common accessory mineral in many different lithologies, significant pyrite oxidation can occur whenever pyritic rocks are exposed to oxygenated water or the atmosphere. Accelerated exposure to oxygen can occur during deforestation, fracking for petroleum, and construction projects. Geochemical models for pyrite oxidation can help us develop strategies to mitigate these deleterious effects. An important component of these models is an accurate pyrite oxidation rate; however, current pyrite oxidation rates have been determined using relatively pure pyrite. Natural pyrite is rarely pure and has a wide range of trace element concentrations that may affect the oxidation rate. Furthermore, the position of trace elements within the mineral lattice can also affect the oxidation rate. For example, elements such as Ni and Co, which substitute into the pyrite lattice, are thought to stabilize the lattice and thus prevent pyrite oxidation. Alternatively, trace elements that are held within inclusions of other minerals could form a galvanic cell with the surrounding pyrite, thus enhancing pyrite oxidation rates. In this study, we present preliminary analyses from three different pyrite oxidation experiments each using natural pyrite with different trace element compositions. These results show that the pyrite with the highest trace element concentration has approximately an order of magnitude higher oxidation rate compared to the lowest trace element sample. To further elucidate the mechanisms, we employed microanalytical techniques to investigate how the trace elements are held within the pyrite. LA-ICPMS was used to determine the

Decomposition of pyrite and the interaction of pyrite with coal organic matrix in pyrolysis and hydropyrolysis

Energy Technology Data Exchange (ETDEWEB)

Chen, H.; Li, B.; Zhang, B. [Chinese Academy of Sciences, Taiyuan (China). Institute of Coal Chemistry

1999-07-01

The thermal decomposition and reduction behaviour of pure pyrite crystals were studied under nitrogen and hydrogen atmospheres. Decomposition of pyrite in coal during pyrolysis and hydropyrolysis, and the behaviour of organic sulphur, are discussed. Temperature and pressure effects are considered. 7 refs., 6 figs., 1 tab.

Quantification of the "global" authigenic carbonate δ13C value and implications for carbon cycling

Science.gov (United States)

Loyd, S. J.

2017-12-01

Relationships among early Earth ocean chemistry, atmospheric chemistry and the evolution/radiation of life have been inferred from carbon isotope compositions (δ13C) of marine carbonates. Under steady-state conditions, the isotope compositions of marine carbonates reflect both the amount and δ13C of carbon entering and leaving the oceans. Recently the traditional "two-output" (marine carbonate and organic matter) mass-balance equation has been modified to include a third, authigenic carbonate output term. However, the formation mechanisms of authigenic carbonates remain poorly understood, particularly from a global prospective. The utility of the new mass-balance approach will be limited until authigenic carbonates are better characterized (e.g., through δ13C analyses). Authigenic carbonates form largely as a result of 1) the respiratory degradation of organic matter (e.g., sulfate reduction), 2) the oxidation of methane and 3) the production of methane. These major reaction pathways can produce authigenic carbonates with highly variable δ13C compositions (δ13Cac). Spatiotemporal variation in the extent and prevalence of different pathways therefore exert a first order control on "global" δ13Cac. Here, values are compiled from new and existing data sets and a modern, global δ13Cac is calculated. When calculated as an average of all data or an averaged mean of individual sites, this value is very similar to normal marine sedimentary organic matter. This finding suggests that marine sediments behave largely as closed systems in the context of organic matter degradation and carbonate authigenesis. In addition, the lack of significant difference between authigenic and organic δ13C implies that these two mass-balance output terms can be considered collectively in more recent time intervals. It may be appropriate to separate these two terms when characterizing more ancient settings when redox characteristics promoted more reducing organic matter degradation

Moessbauer investigation of gold-bearing pyrite-rich concentrates

International Nuclear Information System (INIS)

Wagner, F.E.; Harris, D.C.

1994-01-01

A gold-bearing pyrite-rich concentrate of a refractory ore from the Golden Bear mine, northwestern British Columbia, and a pyrite-rich concentrate from Newhawk's west zone, Brucejack Lake area, northern British Columbia, containing 38 and 316 ppm Au and 0.57% and 0.19% As, respectively, have been investigated using 197 Au and 57 Fe Moessbauer spectroscopy. In the Golden Bear sample, the gold is mainly chemically bound in the pyrite with minor amounts present as an Au-Ag alloy, whereas in the Newhawk sample, the gold occurs mainly as an Au-Ag alloy with a composition close to Au 0.5 Ag 0.5 and is only partly bound in the pyrite. Having mean isomer shifts of +3.2 and +4.0 mm/s with respect to a Pt metal source, the gold in pyrite exhibits shifts similar to those observed for gold in arsenopyrite. The nature of the lattice sites occupied by the gold in pyrite is discussed. (orig.)

Occurrence and geochemical behavior of arsenic in a coastal aquifer–aquitard system of the Pearl River Delta, China

International Nuclear Information System (INIS)

Wang, Ya; Jiao, Jiu Jimmy; Cherry, John A.

2012-01-01

Elevated concentrations of arsenic, up to 161 μg/L, have been identified in groundwater samples from the confined basal aquifer underlying the aquitard of the Pearl River Delta (PRD). Both aquatic arsenic in pore water and solid arsenic in the sediments in the basal aquifer and aquitard were identified. Arsenic speciation of groundwater in the basal aquifer was elucidated on a pH-Eh diagram. In the PRD, arsenic is enriched in groundwater having both low and high salinity, and arsenic enriched groundwater is devoid of dissolved oxygen, has negative Eh values, is slightly alkaline, and has abnormally high concentrations of ammonium and dissolved organic carbon, but low concentrations of nitrate and nitrite. Results of geochemical and hydrochemical analyses and sequential extraction analysis suggest that reductive dissolution of iron oxyhydroxide could be one of the important processes that mobilized solid arsenic. We speculate that mineralization of sedimentary organic matter could also contribute to aquatic arsenic. Scanning electron microscope analysis confirms that abundant authigenic pyrite is present in the sediments. Sulphate derived from paleo-seawater served as the important sulfur source for authigenic pyrite formation. Co-precipitation of arsenic with authigenic pyrite significantly controlled concentrations of aquatic arsenic in the coastal aquifer–aquitard system. - Highlights: ► Coastal aquifer and aquitard are treated as an integrate system. ► Both aquatic arsenic and solid arsenic are observed. ► Aquatic arsenic is derived from reductive dissolution of iron oxyhydroxide. ► Aquatic arsenic can also derived from mineralization of sedimentary organic matter. ► Co-precipitation of arsenic with authigenic pyrite is significant in such a system.

Occurrence and geochemical behavior of arsenic in a coastal aquifer-aquitard system of the Pearl River Delta, China

Energy Technology Data Exchange (ETDEWEB)

Wang, Ya [Department of Earth Sciences, The University of Hong Kong, Hong Kong (China); Jiao, Jiu Jimmy, E-mail: jjiao@hku.hk [Department of Earth Sciences, The University of Hong Kong, Hong Kong (China); Cherry, John A. [School of Engineering, University of Guelph, Guelph, ON, Canada N1G 2W1 (Canada)

2012-06-15

Elevated concentrations of arsenic, up to 161 {mu}g/L, have been identified in groundwater samples from the confined basal aquifer underlying the aquitard of the Pearl River Delta (PRD). Both aquatic arsenic in pore water and solid arsenic in the sediments in the basal aquifer and aquitard were identified. Arsenic speciation of groundwater in the basal aquifer was elucidated on a pH-Eh diagram. In the PRD, arsenic is enriched in groundwater having both low and high salinity, and arsenic enriched groundwater is devoid of dissolved oxygen, has negative Eh values, is slightly alkaline, and has abnormally high concentrations of ammonium and dissolved organic carbon, but low concentrations of nitrate and nitrite. Results of geochemical and hydrochemical analyses and sequential extraction analysis suggest that reductive dissolution of iron oxyhydroxide could be one of the important processes that mobilized solid arsenic. We speculate that mineralization of sedimentary organic matter could also contribute to aquatic arsenic. Scanning electron microscope analysis confirms that abundant authigenic pyrite is present in the sediments. Sulphate derived from paleo-seawater served as the important sulfur source for authigenic pyrite formation. Co-precipitation of arsenic with authigenic pyrite significantly controlled concentrations of aquatic arsenic in the coastal aquifer-aquitard system. - Highlights: Black-Right-Pointing-Pointer Coastal aquifer and aquitard are treated as an integrate system. Black-Right-Pointing-Pointer Both aquatic arsenic and solid arsenic are observed. Black-Right-Pointing-Pointer Aquatic arsenic is derived from reductive dissolution of iron oxyhydroxide. Black-Right-Pointing-Pointer Aquatic arsenic can also derived from mineralization of sedimentary organic matter. Black-Right-Pointing-Pointer Co-precipitation of arsenic with authigenic pyrite is significant in such a system.

Pyrite-coated granite cobbles at Lee Bay, Stewart Island

International Nuclear Information System (INIS)

Brathwaite, R.L.; Skinner, D.N.B.; Faure, K.; Edwards, E.

2014-01-01

On the west side of Lee Bay on the northeast coast of Stewart Island, ventifact cobbles of pyrite-coated granite occur on the beach near the high tide mark and appear to be derived from a sand-cemented gravel deposit that forms a low bank at the back of the beach. The pyrite coat (up to 1 mm thick) completely covers the granitic cobbles and is zoned, with an inner zone of fine-grained colloform pyrite and an outer framboidal zone. Framboidal pyrite is typically formed in anoxic sedimentary environments. Subrounded grains of hematite, ilmenite with hematite blebs, magnetite, feldspar, biotite, quartz and zircon are present in the outer framboidal zone, with some ilmenite and hematite grains being partially replaced by pyrite. The assemblage of ilmenite-hematite-magnetite-biotite-zircon is similar both in mineralogy and size range to that found in heavy mineral beach sands. Sulphur isotope values of the pyrite coat are consistent with formation of the pyrite by microbial sulphate reduction of seawater sulphate. The framboidal texture together with the presence of grains of beach sand in the pyrite coating indicate that it was deposited in a low-temperature sedimentary environment. (author)

Thermal behaviors of mechanically activated pyrites by thermogravimetry (TG)

International Nuclear Information System (INIS)

Hu Huiping; Chen Qiyuan; Yin Zhoulan; Zhang Pingmin

2003-01-01

The thermal decompositions of mechanically activated and non-activated pyrites were studied by thermogravimetry (TG) at the heating rate of 10 K min -1 in argon. Results indicate that the initial temperature of thermal decomposition (T di ) in TG curves for mechanically activated pyrites decreases gradually with increasing the grinding time. The specific granulometric surface area (S G ), the structural disorder of mechanically activated pyrites were analyzed by X-ray diffraction laser particle size analyzer, and X-ray powder diffraction analysis (XRD), respectively. The results show that the S G of mechanically activated pyrites remains almost constant after a certain grinding time, and lattice distortions (ε) rise but the crystallite sizes (D) decrease with increasing the grinding time. All these results imply that the decrease of T di in TG curves of mechanically activated pyrites is mainly caused by the increase of lattice distortions ε and the decrease of the crystallite sizes D of mechanically activated pyrite with increasing the grinding time. The differences in the reactivity between non-activated and mechanically activated pyrites were observed using characterization of the products obtained from 1 h treatment of non-activated and mechanically activated pyrites at 713 K under inert atmosphere and characterization of non-activated and mechanically activated pyrites exposed to ambient air for a certain period

Strontium isotopic stratigraphy utilizing authigenic dolomites in hemipelagic sediments

Energy Technology Data Exchange (ETDEWEB)

Baker, P.A. (Duke Univ., Durham, NC (USA)); Kastner, M. (Scripps Institute of Oceanography, La Jolla, CA (USA)); Elderfield, H. (Univ. of Cambridge (England))

1990-05-01

Authigenic dolomites commonly occur in organic-rich, continental margin marine sediments. These dolomites play a key role in the age dating of stratigraphic sections. The dolomites often are the only lithology amenable to paleomagnetic stratigraphy; they preserve siliceous microfossils against diagenetic; recrystallization, and provide useful strontium isotopic stratigraphic ages. Several potential sources of error frequently are unique to the use of authigenic dolomites in the strontium isotope methods. (1) The dolomites occur as cements of the host lithology, hence, they are not a pure phase. Potentially important contaminants during analysis include gypsum clay minerals, feldspars, and iron and manganese oxides. Strontium may occur as a structural substituent ion in these minerals or as a surface-adsorbed ion. Various leaching techniques have been tested to isolate dolomitic strontium. Purer dolomites and strontium-enriched dolomites often can be selected to ease these problems. (2) The dolomites form after the deposition of the host sediment, therefore, they record the diagenetic age not the depositional age. The stable isotopic composition of the dolomites can aid in selection of early formed samples. (3) The dolomites record pore-water strontium isotope compositions, not seawater isotopic compositions. This problem is also minimized by choosing dolomites formed near the sediment-water interface. (4) The dolomites formed near the sediment-water interface originated as rotodolomites and undergo subsequent burial diagenesis, creating a potential for later strontium isotope exchange. This problem is minimized by selecting fresh samples from the interior of nearly impermeable beds and nodules. Results from the Miocene Monterey Formation of California and from the Eocene through Pliocene Pisco basin of Peru show that authigenic dolomites can provide useful strontium isotopic age estimates.

Carrier-microencapsulation using Si-catechol complex for suppressing pyrite floatability

Energy Technology Data Exchange (ETDEWEB)

Jha, R.K.T.; Satur, J.; Hiroyoshi, N.; Ito, M.; Tsunekawa, M. [Hokkaido University, Hokkaido (Japan). Graduate School of Engineering

2008-11-15

Pyrite (FeS{sub 2}) is a common sulfide mineral associated with valuable metal minerals and coal, and it is rejected as a gangue mineral using physical separation techniques such as froth flotation and discharged into tailing pond. In the flotation, pyrite is frequently entrapped in the froth due to its hydrophobic nature. Formation of acid mine drainage due to the air-oxidation of pyrite in the tailing pond is also a serious problem. The authors have proposed carrier-microencapsulation (CME) as a method for suppressing both the floatability and oxidation of pyrite. In this method, pyrite is coated with a thin layer of metal oxide or hydroxide using catechol solution as a carrier combined with metal ions. The layer converts the pyrite surface from hydrophobic to hydrophilic and acts as a protective coating against oxidation. The present study demonstrates the effect of CME using Si-catechol complex to suppress the pyrite floatability: The bubble pick-up experiments showed that attachment of pyrite particles to air bubble is suppressed by the CME treatment at pH 4-10, Si-catechol complex concentration over 0.5 mol m{sup -3} and treatment time within 2 min. The Hallimond tube flotation experiments showed that the pyrite floatability is suppressed by the CME treatment even in the presence of typical flotation collectors such as kerosene and xanthate. SEM-EDX analysis confirmed that Si present on the pyrite surface treated by Si-catechol complex, implying that SiO{sub 2} or SiOH{sub 4} layer formed by the CME treatment convert the pyrite surface hydrophobic to hydrophilic.

Selective separation of pyrite and chalcopyrite by biomodulation.

Science.gov (United States)

Chandraprabha, M N; Natarajan, K A; Modak, Jayant M

2004-09-01

Selective separation of pyrite from other associated ferrous sulphides at acidic and neutral pH has been a challenging problem. This paper discusses the utility of Acidithiobacillus ferrooxidans for the selective flotation of chalcopyrite from pyrite. Consequent to interaction with bacterial cells, pyrite remained depressed even in the presence of potassium isopropyl xanthate collector while chalcopyrite exhibited significant flotability. However, when the minerals were conditioned together, the selectivity achieved was poor due to the activation of pyrite surface by the copper ions in solution. The selectivity was improved when the sequence of conditioning with bacterial cells and collector was reversed, since the bacterial cells were able to depress collector interacted pyrite effectively, while having negligible effect on chalcopyrite. The observed behaviour is analysed and discussed in detail. The separation obtained was significant both at acidic and alkaline pH. This selectivity achieved was retained when the minerals were interacted with both bacterial cells and collector simultaneously.

Iron and Sulfur Species and Sulfur Isotopic Compositions of Authigenic Pyrite in Gas Hydrate-Bearing Sediments from Hydrate Ridge, Cascadia Margin (ODP Leg 204): A Proposal of Conceptual Models to Indicate the Non-Steady State Depositional and Diagenetic Processes

Science.gov (United States)

Liu, C.; Jiang, S. Y.; Su, X.

2017-12-01

Two accretionary sediment sequences from Sites 1245 and 1252 recovered during Ocean Drilling Program (ODP) Leg 204 at Hydrate Ridge, Cascadia Margin were investigated to explore the non-steady state depositional and diagenetic history. Five iron species and three sulfur species were chemically extracted, and their concentrations and the sulfur isotopic compositions of pyrite were determined. After the mineral recognitions of these species and detailed comparative analyses, the aerobic history of bottom seawater has been determined. The formation of pyrite is thought to be controlled by the limited production of hydrogen sulfide relative to the supply of reactive iron. Also, the intrusion of oxygen by bioturbation would oxidize the reduced sulfur species and further suppress pyritization. To explain the geochemical relationship between pyrite and siderite and the sulfur isotope characteristics of pyrite, we propose seven conceptual models based on the variations in depositional rate and methane flux, and the models succeed in explaining the geochemical results and are validated by the observed non-steady state events. These models may contribute to the reconstruction of the non-steady state processes in other research areas in the future.

Retention and reduction of uranium on pyrite surface

International Nuclear Information System (INIS)

Eglizaud, N.

2006-12-01

In the hypothesis of a storage of the spent fuel in a deep geological formation, understanding the uranium dispersion in the environment is important. Pyrite is a reducing mineral present in the Callovo-Oxfordian argilites, the geological formation actually studied for such a storage. However, pyrite impact on uranium migration has already been poorly studied. The aim of the study was to understand the mechanisms of uranium(VI) retention and reduction on the pyrite surface (FeS 2 ). Solution chemistry was therefore coupled with solid spectroscopic studies (XPS and Raman spectroscopy). All uranium-pyrite interactions experiments were performed under an anoxic atmosphere, in a glove box. Pyrite dissolution under anoxic conditions releases sulfoxy-anions and iron(II), which can then be adsorbed on the pyrite surface. This adsorption was confirmed by interaction experiments using iron(II) isotopic dilution. Uranium(VI) is retained by an exchange reaction with iron(II) adsorbed on sulphur sites, with a maximal amount of sorbed uranium at pH ≥ 5.5. Cobalt(II) and europium(III) are also adsorbed on the pyrite surface above pH 5.5 confirming then that reduction is not required for species to adsorb on pyrite. When the concentration of uranium retained is lower than 4 x 10 -9 mol g -1 , an oxidation-reduction reaction leads to the formation of a uranium (VI) (IV) mixed oxide and to solid sulphur (d.o. ≥ -I). During this reaction, iron remains mostly at the +II oxidation degree. The reaction products seem to passivate the pyrite surface: at higher amounts of retained uranium, the oxidation-reduction reaction is no longer observed. The surface is saturated by the retention of (3.4 ± 0.8) x 10 -7 mol L -1 of uranium(VI). Modelling of uranium sorption at high surface coverage (≥ 4 x 10 -9 mol g -1 ) by the Langmuir model yields an adsorption constant of 8 x 10 7 L mol -1 . Finally, a great excess of uranium(VI) above the saturation concentration allows the observation of

Chemical Interactions of Hydraulic Fracturing Biocides with Natural Pyrite

Science.gov (United States)

Consolazio, Nizette A.

In conjunction with horizontal drilling, hydraulic fracturing or fracking has enabled the recovery of natural gas from low permeable shale formations. In addition to water, these fracking fluids employ proppants and up to 38 different chemical additives to improve the efficiency of the process. One important class of additives used in hydraulic fracturing is biocides. When applied appropriately, they limit the growth of harmful microorganisms within the well, saving energy producers 4.5 billion dollars each year. However, biocides or their harmful daughter products may return to the surface in produced water, which must then be appropriately stored, treated and disposed of. Little is known about the effect of mineral-fluid interactions on the fate of the biocides employed in hydraulic fracturing. In this study, we employed laboratory experiments to determine changes in the persistence and products of these biocides under controlled environments. While many minerals are present in shale formations, pyrite, FeS2(s) is particularly interesting because of its prevalence and reactivity. The FeII groups on the face of pyrite may be oxidized to form FeIII phases. Both of these surfaces have been shown to be reactive with organic compounds. Chlorinated compounds undergo redox reactions at the pyrite-fluid interface, and sulfur-containing compounds undergo exceptionally strong sorption to both pristine and oxidized pyrite. This mineral may significantly influence the degradation of biocides in the Marcellus Shale. Thus, the overall goal of this study was to understand the effect of pyrite on biocide reactivity in hydraulic fracturing, focusing on the influence of pyrite on specific functional groups. The first specific objective was to demonstrate the effect of pyrite and pyrite reaction products on the degradation of the bromine-containing biocide, DBNPA. On the addition of pyrite to DBNPA, degradation rates of the doubly brominated compound were found to increase

Retention and reduction of uranium on pyrite surface; Retention et reduction de l'uranium a la surface de la pyrite

Energy Technology Data Exchange (ETDEWEB)

Eglizaud, N

2006-12-15

In the hypothesis of a storage of the spent fuel in a deep geological formation, understanding the uranium dispersion in the environment is important. Pyrite is a reducing mineral present in the Callovo-Oxfordian argilites, the geological formation actually studied for such a storage. However, pyrite impact on uranium migration has already been poorly studied. The aim of the study was to understand the mechanisms of uranium(VI) retention and reduction on the pyrite surface (FeS{sub 2}). Solution chemistry was therefore coupled with solid spectroscopic studies (XPS and Raman spectroscopy). All uranium-pyrite interactions experiments were performed under an anoxic atmosphere, in a glove box. Pyrite dissolution under anoxic conditions releases sulfoxy-anions and iron(II), which can then be adsorbed on the pyrite surface. This adsorption was confirmed by interaction experiments using iron(II) isotopic dilution. Uranium(VI) is retained by an exchange reaction with iron(II) adsorbed on sulphur sites, with a maximal amount of sorbed uranium at pH {>=} 5.5. Cobalt(II) and europium(III) are also adsorbed on the pyrite surface above pH 5.5 confirming then that reduction is not required for species to adsorb on pyrite. When the concentration of uranium retained is lower than 4 x 10{sup -9} mol g{sup -1}, an oxidation-reduction reaction leads to the formation of a uranium (VI) (IV) mixed oxide and to solid sulphur (d.o. {>=} -I). During this reaction, iron remains mostly at the +II oxidation degree. The reaction products seem to passivate the pyrite surface: at higher amounts of retained uranium, the oxidation-reduction reaction is no longer observed. The surface is saturated by the retention of (3.4 {+-} 0.8) x 10{sup -7} mol L{sup -1} of uranium(VI). Modelling of uranium sorption at high surface coverage ({>=} 4 x 10{sup -9} mol g{sup -1}) by the Langmuir model yields an adsorption constant of 8 x 10{sup 7} L mol{sup -1}. Finally, a great excess of uranium(VI) above the

Genesis of uranium-gold pyritic conglomerates

International Nuclear Information System (INIS)

Myers, W.B.

1981-01-01

The ancient pyritic ore conglomerates have a common origin best exemplified by the Witwatersrand deposits. All contain detrital pyrite and uraninite, which are unstable in modern oxygenated environments and were deposited in a reducing atmosphere. The Rand reefs are not similar to modern gold placers. Placers result from the near incapacity of streams and currents to transport coarse gold. Placers as rich as Rand reef occur only in narrow paystreaks within 15 kilometers of a coarse-gold source. The board dispersion of gold in the reefs is due to solution transport of metal complexed as aurous sulfide, leached anoxygenically from crustal rocks, probably from sea-floor basalt, and precipitated by a slow reaction driven by the radioactive decay of detrital uraninite. Radiolysis of water on shallow marine unconformities resulted in diffusion of hydrogen to the atmosphere and a slight excess of hydroxyl free radical in the reef environment. The mild oxidizing tendency slowly dissolved uranium, precipitated gold, and oxygenated thucholite. These actions define a maturing process. A uraninite placer accumulating on an unconformity becomes progressively converted to a gold reef with little residual uraninite. The most mature reefs tend to grade toward the thucholite-seam type, very thin but exceedingly rich in gold. A combination of chemical attack and physical reworking accounts for the general thinness of mature reefs. Pyrite, like uraninite, decreases in abundance with increasing maturity; buffering by pyrite moderated the oxidative depletion of uranium. Where pyrite was scanty or absent, uraninite was completely dissolved by the effects of radiolysis and no ore formed

Enhancement of Biofilm Formation on Pyrite by Sulfobacillus thermosulfidooxidans

Directory of Open Access Journals (Sweden)

Qian Li

2016-07-01

Full Text Available Bioleaching is the mobilization of metal cations from insoluble ores by microorganisms. Biofilms can enhance this process. Since Sulfobacillus often appears in leaching heaps or reactors, this genus has aroused attention. In this study, biofilm formation and subsequent pyrite dissolution by the Gram-positive, moderately thermophilic acidophile Sulfobacillus thermosulfidooxidans were investigated. Five strategies, including adjusting initial pH, supplementing an extra energy source or ferric ions, as well as exchanging exhausted medium with fresh medium, were tested for enhancement of its biofilm formation. The results show that regularly exchanging exhausted medium leads to a continuous biofilm development on pyrite. By this way, multiply layered biofilms were observed on pyrite slices, while only monolayer biofilms were visible on pyrite grains. In addition, biofilms were proven to be responsible for pyrite leaching in the early stages.

Biological surveys on the Savannah River in the vicinity of the Savannah River Plant (1951-1976)

Energy Technology Data Exchange (ETDEWEB)

Matthews, R. A.

1982-04-01

In 1951, the Academy of Natural Sciences of Philadelphia was contracted by the Savannah River Plant to initiate a long-term monitoring program in the Savannah River. The purpose of this program was to determine the effect of the Savannah River Plant on the Savannah River aquatic ecosystem. The data from this monitoring program have been computerized by the Savannah River Laboratory, and are summarized in this report. During the period from 1951-1976, 16 major surveys were conducted by the Academy in the Savannah River. Water chemistry analyses were made, and all major biological communities were sampled qualitatively during the spring and fall of each survey year. In addition, quantitative diatom data have been collected quarterly since 1953. Major changes in the Savannah River basin, in the Savannah River Plant's activities, and in the Academy sampling patterns are discussed to provide a historical overview of the biomonitoring program. Appendices include a complete taxonomic listing of species collected from the Savannah River, and summaries of the entire biological and physicochemical data base.

Fabrication and characterization of PDLLA/pyrite composite bone ...

Indian Academy of Sciences (India)

Polylactic acid; Chinese herbal medicine; pyrite; scaffold; bone regeneration; cell culture. 1. Introduction ... research focuses on the direct cellular level effect of pyrite on bone cells. ..... optimal scaffold from the results of this paper. Although the.

Nucleic acid interactions with pyrite surfaces

International Nuclear Information System (INIS)

Mateo-Marti, E.; Briones, C.; Rogero, C.; Gomez-Navarro, C.; Methivier, Ch.; Pradier, C.M.; Martin-Gago, J.A.

2008-01-01

The study of the interaction of nucleic acid molecules with mineral surfaces is a field of growing interest in organic chemistry, origin of life, material science and biotechnology. We have characterized the adsorption of single-stranded peptide nucleic acid (ssPNA) on a natural pyrite surface, as well as the further adsorption of ssDNA on a PNA-modified pyrite surface. The characterization has been performed by means of reflection absorption infrared spectroscopy (RAIRS), atomic force microscopy (AFM) and X-ray photoemission spectroscopy (XPS) techniques. The N(1s) and S(2p) XPS core level peaks of PNA and PNA + DNA have been decomposed in curve-components that we have assigned to different chemical species. RAIRS spectra recorded for different concentrations show the presence of positive and negative adsorption bands, related to the semiconducting nature of the surface. The combination of the information gathered by these techniques confirms that PNA adsorbs on pyrite surface, interacting through nitrogen-containing groups of the nucleobases and the iron atoms of the surface, instead of the thiol group of the molecule. The strong PNA/pyrite interaction inhibits further hybridization of PNA with complementary ssDNA, contrary to the behavior reported on gold surfaces

Nucleic acid interactions with pyrite surfaces

Energy Technology Data Exchange (ETDEWEB)

Mateo-Marti, E. [Centro de Astrobiologia (CSIC-INTA), Ctra. Ajalvir, Km. 4, 28850-Torrejon de Ardoz, Madrid (Spain)], E-mail: mateome@inta.es; Briones, C.; Rogero, C. [Centro de Astrobiologia (CSIC-INTA), Ctra. Ajalvir, Km. 4, 28850-Torrejon de Ardoz, Madrid (Spain); Gomez-Navarro, C. [Instituto de Ciencia de Materiales de Madrid (CSIC), Cantoblanco, 28049-Madrid (Spain); Methivier, Ch.; Pradier, C.M. [Laboratoire de Reactivite de Surface, UMR CNRS 7609. Universite Pierre et Marie Curie, 4, Pl Jussieu, 75005-Paris (France); Martin-Gago, J.A. [Centro de Astrobiologia (CSIC-INTA), Ctra. Ajalvir, Km. 4, 28850-Torrejon de Ardoz, Madrid (Spain); Instituto de Ciencia de Materiales de Madrid (CSIC), Cantoblanco, 28049-Madrid (Spain)

2008-09-03

The study of the interaction of nucleic acid molecules with mineral surfaces is a field of growing interest in organic chemistry, origin of life, material science and biotechnology. We have characterized the adsorption of single-stranded peptide nucleic acid (ssPNA) on a natural pyrite surface, as well as the further adsorption of ssDNA on a PNA-modified pyrite surface. The characterization has been performed by means of reflection absorption infrared spectroscopy (RAIRS), atomic force microscopy (AFM) and X-ray photoemission spectroscopy (XPS) techniques. The N(1s) and S(2p) XPS core level peaks of PNA and PNA + DNA have been decomposed in curve-components that we have assigned to different chemical species. RAIRS spectra recorded for different concentrations show the presence of positive and negative adsorption bands, related to the semiconducting nature of the surface. The combination of the information gathered by these techniques confirms that PNA adsorbs on pyrite surface, interacting through nitrogen-containing groups of the nucleobases and the iron atoms of the surface, instead of the thiol group of the molecule. The strong PNA/pyrite interaction inhibits further hybridization of PNA with complementary ssDNA, contrary to the behavior reported on gold surfaces.

Source of arsenic-bearing pyrite in southwestern Vermont, USA: Sulfur isotope evidence

Energy Technology Data Exchange (ETDEWEB)

Mango, Helen, E-mail: helen.mango@castleton.edu [Department of Natural Sciences, Castleton State College, 233 South Street, Castleton, VT 05735 (United States); Ryan, Peter, E-mail: pryan@middlebury.edu [Department of Geology, Middlebury College, 276 Bicentennial Way, Middlebury, VT 05753 (United States)

2015-02-01

Arsenic-bearing pyrite is the source of arsenic in groundwater produced in late Cambrian and Ordovician gray and black slates and phyllites in the Taconic region of southwestern Vermont, USA. The aim of this study is to analyze the sulfur isotopic composition of this pyrite and determine if a relationship exists between pyrite δ{sup 34}S and arsenic content. Pyrite occurs in both sedimentary/diagenetic (bedding-parallel layers and framboids) and low-grade metamorphic (porphyroblast) forms, and contains up to > 2000 ppm As. The sulfur isotopic composition of arsenic-bearing pyrite ranges from − 5.2‰ to 63‰. In the marine environment, the sulfur in sedimentary pyrite becomes increasingly enriched in {sup 34}S as the geochemical environment becomes increasingly anoxic. There is a positive correlation between δ{sup 34}S and arsenic content in the Taconic pyrite, suggesting that uptake of arsenic by pyrite increased as the environment became more reducing. This increased anoxia may have been due to a rise in sea level and/or tectonic activity during the late Cambrian and Ordovician. Low-grade metamorphism appears to have little effect on sulfur isotope composition, but does correlate with lower arsenic content in pyrite. New groundwater wells drilled in this region should therefore avoid gray and black slates and phyllites that contain sedimentary/diagenetic pyrite with heavy δ{sup 34}S values. - Highlights: • Pyrite is the source of arsenic in groundwater in the Taconic region of Vermont, USA. • As-bearing pyrite δ{sup 34}S = – 5.2 to 63‰ with higher {sup 34}S as environment becomes more anoxic. • High sea level, tectonic activity create anoxia, with incorporation of As into pyrite. • New wells should avoid slate/phyllite containing sedimentary pyrite with heavy δ{sup 34}S.

Source of arsenic-bearing pyrite in southwestern Vermont, USA: Sulfur isotope evidence

International Nuclear Information System (INIS)

Mango, Helen; Ryan, Peter

2015-01-01

Arsenic-bearing pyrite is the source of arsenic in groundwater produced in late Cambrian and Ordovician gray and black slates and phyllites in the Taconic region of southwestern Vermont, USA. The aim of this study is to analyze the sulfur isotopic composition of this pyrite and determine if a relationship exists between pyrite δ 34 S and arsenic content. Pyrite occurs in both sedimentary/diagenetic (bedding-parallel layers and framboids) and low-grade metamorphic (porphyroblast) forms, and contains up to > 2000 ppm As. The sulfur isotopic composition of arsenic-bearing pyrite ranges from − 5.2‰ to 63‰. In the marine environment, the sulfur in sedimentary pyrite becomes increasingly enriched in 34 S as the geochemical environment becomes increasingly anoxic. There is a positive correlation between δ 34 S and arsenic content in the Taconic pyrite, suggesting that uptake of arsenic by pyrite increased as the environment became more reducing. This increased anoxia may have been due to a rise in sea level and/or tectonic activity during the late Cambrian and Ordovician. Low-grade metamorphism appears to have little effect on sulfur isotope composition, but does correlate with lower arsenic content in pyrite. New groundwater wells drilled in this region should therefore avoid gray and black slates and phyllites that contain sedimentary/diagenetic pyrite with heavy δ 34 S values. - Highlights: • Pyrite is the source of arsenic in groundwater in the Taconic region of Vermont, USA. • As-bearing pyrite δ 34 S = – 5.2 to 63‰ with higher 34 S as environment becomes more anoxic. • High sea level, tectonic activity create anoxia, with incorporation of As into pyrite. • New wells should avoid slate/phyllite containing sedimentary pyrite with heavy δ 34 S

Degradation of Diclofenac by sonosynthesis of pyrite nanoparticles.

Science.gov (United States)

Khabbaz, M; Entezari, M H

2017-02-01

The aim of this work is to evaluate the ability of synthesized pyrite nanoparticles (NPs) on the degradation of Diclofenac (DCF) as a model pharmaceutical pollutant. Pyrite NPs were synthesized by sonication with 20 kHz apparatus under optimum conditions. The effects of pyrite loading (0.02-0.20 g/L), DCF concentration (10-50 mg/L) and initial pH (2-10) on the degradation were investigated. The results revealed that the NPs have a great activity in the degradation of DCF with 25 mg/L concentration. A first-order kinetic model was found to match the experimental data. Complete degradation (100%) of DCF was achieved by pyrite within 3 min and 20 min in acidic and natural pH, respectively. To gain an understanding of the degradation mechanism and the role of pyrite, a UV-Vis spectrophotometer was employed to follow the DCF concentration. In addition, the Chemical Oxygen Demand (COD) and the amounts of ammonium and chloride ions verified complete degradation of DCF in both pH values. The results demonstrated that Fe 2+ ions were generated by the pyrite surface and the hydroxyl radical (OH) was formed by Fe 2+ ions through the Fenton reaction. Based on using radical scavengers in the degradation process, OH was mainly responsible for the fast degradation of DCF. COD measurements confirmed that DCF finally degraded to further oxidized forms (NH 4 + , Cl - ). Copyright © 2016 Elsevier Ltd. All rights reserved.

Pyrite oxidation under simulated acid rain weathering conditions.

Science.gov (United States)

Zheng, Kai; Li, Heping; Wang, Luying; Wen, Xiaoying; Liu, Qingyou

2017-09-01

We investigated the electrochemical corrosion behavior of pyrite in simulated acid rain with different acidities and at different temperatures. The cyclic voltammetry, polarization curve, and electrochemical impedance spectroscopy results showed that pyrite has the same electrochemical interaction mechanism under different simulated acid rain conditions, regardless of acidity or environmental temperature. Either stronger acid rain acidity or higher environmental temperature can accelerate pyrite corrosion. Compared with acid rain having a pH of 5.6 at 25 °C, the prompt efficiency of pyrite weathering reached 104.29% as the acid rain pH decreased to 3.6, and it reached 125.31% as environmental temperature increased to 45 °C. Increasing acidity dramatically decreases the charge transfer resistance, and increasing temperature dramatically decreases the passivation film resistance, when other conditions are held constant. Acid rain always causes lower acidity mine drainage, and stronger acidity or high environmental temperatures cause serious acid drainage. The natural parameters of latitude, elevation, and season have considerable influence on pyrite weathering, because temperature is an important influencing factor. These experimental results are of direct significance for the assessment and management of sulfide mineral acid drainage in regions receiving acid rain.

Comparison Analysis of Coal Biodesulfurization and Coal's Pyrite Bioleaching with Acidithiobacillus ferrooxidans

Science.gov (United States)

Hong, Fen-Fen; He, Huan; Liu, Jin-Yan; Tao, Xiu-Xiang; Zheng, Lei; Zhao, Yi-Dong

2013-01-01

Acidithiobacillus ferrooxidans (A. ferrooxidans) was applied in coal biodesulfurization and coal's pyrite bioleaching. The result showed that A. ferrooxidans had significantly promoted the biodesulfurization of coal and bioleaching of coal's pyrite. After 16 days of processing, the total sulfur removal rate of coal was 50.6%, and among them the removal of pyritic sulfur was up to 69.9%. On the contrary, after 12 days of processing, the coal's pyrite bioleaching rate was 72.0%. SEM micrographs showed that the major pyrite forms in coal were massive and veinlets. It seems that the bacteria took priority to remove the massive pyrite. The sulfur relative contents analysis from XANES showed that the elemental sulfur (28.32%) and jarosite (18.99%) were accumulated in the biotreated residual coal. However, XRD and XANES spectra of residual pyrite indicated that the sulfur components were mainly composed of pyrite (49.34%) and elemental sulfur (50.72%) but no other sulfur contents were detected. Based on the present results, we speculated that the pyrite forms in coal might affect sulfur biooxidation process. PMID:24288464

Pyritic ash-flow tuff, Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Castor, S.B.; Tingley, J.V.; Bonham, H.F. Jr.

1994-01-01

The Yucca Mountain site is underlain by a 1,500-m-thick Miocene volcanic sequence that comprises part of the southwestern Nevada volcanic field. Rocks of this sequence, which consists mainly of ash-flow tuff sheets with minor flows and bedded tuff, host precious metal mineralization in several areas as near as 10 km from the site. In two such areas, the Bullfrog and Bare Mountain mining districts, production and reserves total over 60 t gold and 150 t silver. Evidence of similar precious metal mineralization at the Yucca Mountain site may lead to mining or exploratory drilling in the future, compromising the security of the repository. The authors believe that most of the pyrite encountered by drilling at Yucca Mountain was introduced as pyroclastic ejecta, rather than by in situ hydrothermal activity. Pyritic ejecta in ash-flow tuff are not reported in the literature, but there is no reason to believe that the Yucca Mountain occurrence is unique. The pyritic ejecta are considered by us to be part of a preexisting hydrothermal system that was partially or wholly destroyed during eruption of the tuff units. Because it was introduced as ejecta in tuff units that occur at depths of about 1,000 m, such pyrite does not constitute evidence of shallow mineralization at the proposed repository site; however, the pyrite may be evidence for mineralization deep beneath Yucca Mountain or as much as tens of kilometers from it

Pyrite Iron Sulfide Solar Cells Made from Solution Final Technical Report

Energy Technology Data Exchange (ETDEWEB)

Law, Matt [Univ. of California, Irvine, CA (United States)

2017-03-21

This document summarizes research done under the SunShot Next Generation PV II project entitled, “Pyrite Iron Sulfide Solar Cells Made from Solution,” award number DE-EE0005324, at the University of California, Irvine, from 9/1/11 thru 11/30/16. The project goal was to develop iron pyrite (cubic FeS₂) as an absorber layer for solution-processible p-n heterojunction solar cells with a pathway to >20% power conversion efficiency. Project milestones centered around seven main Tasks: (1) make device-quality pyrite thin-films from solar ink; (2) develop an ohmic bottom contact with suitable low resistivity; (3) produce a p-n heterojunction with VOC > 400 mV; (4) make a solar cell with >5% power conversion efficiency; (5) use alloying to increase the pyrite band gap to ~1.2-1.4 eV; (6) produce a p-n heterojunction with VOC > 500 mV; and finally (7) make a solar cell with >10% power conversion efficiency. In response to project findings, the Tasks were amended midway through the project to focus particular effort on passivating the surface of pyrite in order to eliminate excessively-strong surface band bending believed to be responsible for the low VOC of pyrite diodes. Major project achievements include: (1) development and detailed characterization of several new solution syntheses of high-quality thin-film pyrite, including two “molecular ink” routes; (2) demonstration of Mo/MoS₂ bilayers as good ohmic bottom contacts to pyrite films; (3) fabrication of pyrite diodes with a glass/Mo/MoS₂/pyrite/ZnS/ZnO/AZO layer sequence that show VOC values >400 mV and as high as 610 mV at ~1 sun illumination, although these high VOC values ultimately proved irreproducible; (4) established that ZnS is a promising n-type junction partner for pyrite; (5) used density functional theory to show that the band gap of pyrite can be increased from ~1.0 to a more optimal 1.2-1.3 eV by alloying with oxygen; (6) through extensive measurements of ultrahigh

Greigite: a true intermediate on the polysulfide pathway to pyrite

Directory of Open Access Journals (Sweden)

Benning Liane G

2007-03-01

Full Text Available Abstract The formation of pyrite (FeS2 from iron monosulfide precursors in anoxic sediments has been suggested to proceed via mackinawite (FeS and greigite (Fe3S4. Despite decades of research, the mechanisms of pyrite formation are not sufficiently understood because solid and dissolved intermediates are oxygen-sensitive and poorly crystalline and therefore notoriously difficult to characterize and quantify. In this study, hydrothermal synchrotron-based energy dispersive X-ray diffraction (ED-XRD methods were used to investigate in situ and in real-time the transformation of mackinawite to greigite and pyrite via the polysulfide pathway. The rate of formation and disappearance of specific Bragg peaks during the reaction and the changes in morphology of the solid phases as observed with high resolution microscopy were used to derive kinetic parameters and to determine the mechanisms of the reaction from mackinawite to greigite and pyrite. The results clearly show that greigite is formed as an intermediate on the pathway from mackinawite to pyrite. The kinetics of the transformation of mackinawite to greigite and pyrite follow a zero-order rate law indicating a solid-state mechanism. The morphology of greigite and pyrite crystals formed under hydrothermal conditions supports this conclusion and furthermore implies growth of greigite and pyrite by oriented aggregation of nanoparticulate mackinawite and greigite, respectively. The activation enthalpies and entropies of the transformation of mackinawite to greigite, and of greigite to pyrite were determined from the temperature dependence of the rate constants according to the Eyring equation. Although the activation enthalpies are uncharacteristic of a solid-state mechanism, the activation entropies indicate a large increase of order in the transition state, commensurate with a solid-state mechanism.

Ion-probe U–Pb dating of authigenic and detrital opal from Neogene-Quaternary alluvium

Science.gov (United States)

Neymark, Leonid; Paces, James B.

2013-01-01

Knowing depositional ages of alluvial fans is essential for many tectonic, paleoclimatic, and geomorphic studies in arid environments. The use of U–Pb dating on secondary silica to establish the age of Neogene-Quaternary clastic sediments was tested on samples of authigenic and detrital opal and chalcedony from depths of ∼25 to 53 m in boreholes at Midway Valley, Nevada. Dating of authigenic opal present as rinds on rock clasts and in calcite/silica cements establishes minimum ages of alluvium deposition; dating of detrital opal or chalcedony derived from the source volcanic rocks gives the maximum age of sediment deposition.Materials analyzed included 12 samples of authigenic opal, one sample of fracture-coating opal from bedrock, one sample of detrital opal, and two samples of detrital chalcedony. Uranium–lead isotope data were obtained by both thermal ionization mass spectrometry and ion-microprobe. Uranium concentrations ranged from tens to hundreds of μg/g. Relatively large U/Pb allowed calculation of 206Pb/238U ages that ranged from 1.64±0.36 (2σ) to 6.16±0.50 Ma for authigenic opal and from 8.34±0.28 to 11.2±1.3 Ma for detrital opal/chalcedony. Three samples with the most radiogenic Pb isotope compositions also allowed calculation of 207Pb/235U ages, which were concordant with 206Pb/238U ages from the same samples.These results indicate that basin development at Midway Valley was initiated between about 8 and 6 Ma, and that the basin was filled at long-term average deposition rates of less than 1 cm/ka. Because alluvium in Midway Valley was derived from adjacent highlands at Yucca Mountain, the low rates of deposition determined in this study may imply a slow rate of erosion of Yucca Mountain. Volcanic strata underlying the basin are offset by a number of buried faults to a greater degree than the relatively smooth-sloping bedrock/alluvium contact. These geologic relations indicate that movement on most faults ceased prior to erosional

The effect of lizardite surface characteristics on pyrite flotation

International Nuclear Information System (INIS)

Feng Bo; Feng Qiming; Lu Yiping

2012-01-01

Highlights: ► Two kinds of lizardite samples have different effect on the flotation of pyrite. ► Acid leaching changed the surface characteristics of lizardite mineral. ► The leached lizardite has less magnesium on its surface. ► The electro-kinetic behavior of lizardite aqueous suspensions is mainly a function of the Mg/Si atomic ratio on mineral surface. - Abstract: The effect of lizardite surface characteristics on pyrite flotation has been investigated through flotation tests, adsorption tests, zeta potential measurements, FTIR study, X-ray photoelectron spectroscopy (XPS) and sedimentation tests. The flotation results show that at pH value 9, where flotation of nickel sulfide ores is routinely performed, two kinds of lizardite samples (native lizardite and leached lizardite) have different effects on the flotation of pyrite. The native lizardite adheres to the surface of pyrite and reduces pyrite flotation recovery while the leached lizardite does not interfere with pyrite flotation. Infrared analyses and XPS tests illustrate that acid leaching changed the surface characteristics of lizardite mineral and the leached lizardite has less magnesium on its surface. It has been determined that the electro-kinetic behavior of lizardite aqueous suspensions is mainly a function of the Mg/Si atomic ratio on lizardite surface. So, the low isoelectric point observed in the leached sample has been linked to values of this ratio lower than that of the native lizardite.

Fabrication and characterization of PDLLA/pyrite composite bone ...

Indian Academy of Sciences (India)

Keywords. Polylactic acid; Chinese herbal medicine; pyrite; scaffold; bone regeneration; cell culture. ... Pyrite (FeS2, named as Zi-Ran-Tong in Chinese medicine), as a traditional Chinesemedicine, has been used in the Chinese population to treat bone diseases and to promote bone healing. The mechanical properties of ...

Authigenic gypsum in a deep sea core from Southeastern Arabian Sea

Digital Repository Service at National Institute of Oceanography (India)

Guptha, M.V.S.

Authigenic gypsum has been encountered in a deep sea core RC9-157 from the southeastern Arabian Sea at a depth of 4111 m which is a zone of lysocline. The formation of gypsum in the deep sea region is attributed to the prevailing sulphate rich...

Comparison Analysis of Coal Biodesulfurization and Coal’s Pyrite Bioleaching with Acidithiobacillus ferrooxidans

Directory of Open Access Journals (Sweden)

Fen-Fen Hong

2013-01-01

Full Text Available Acidithiobacillus ferrooxidans (A. ferrooxidans was applied in coal biodesulfurization and coal’s pyrite bioleaching. The result showed that A. ferrooxidans had significantly promoted the biodesulfurization of coal and bioleaching of coal’s pyrite. After 16 days of processing, the total sulfur removal rate of coal was 50.6%, and among them the removal of pyritic sulfur was up to 69.9%. On the contrary, after 12 days of processing, the coal’s pyrite bioleaching rate was 72.0%. SEM micrographs showed that the major pyrite forms in coal were massive and veinlets. It seems that the bacteria took priority to remove the massive pyrite. The sulfur relative contents analysis from XANES showed that the elemental sulfur (28.32% and jarosite (18.99% were accumulated in the biotreated residual coal. However, XRD and XANES spectra of residual pyrite indicated that the sulfur components were mainly composed of pyrite (49.34% and elemental sulfur (50.72% but no other sulfur contents were detected. Based on the present results, we speculated that the pyrite forms in coal might affect sulfur biooxidation process.

Semiconductor electrochemistry of coal pyrite. Final technical report, September 1990--September 1995

Energy Technology Data Exchange (ETDEWEB)

Osseo-Asare, K.; Wei, Dawei

1996-01-01

This project seeks to advance the fundamental understanding of the physico-chemical processes occurring at the pyrite/aqueous interface, in the context of coal cleaning, coal desulfurization, and acid mine drainage. Central to this research is the use of synthetic microsize particles of pyrite as model microelectrodes to investigate the semiconductor electrochemistry of pyrite. The research focuses on: (a) the synthesis of microsize particles of pyrite in aqueous solution at room temperature, (b) the formation of iron sulfide complex, the precursor of FeS or FeS{sub 2}, and (c) the relationship between the semiconductor properties of pyrite and its interfacial electrochemical behavior in the dissolution process. In Chapter 2, 3 and 4, a suitable protocol for preparing microsize particles of pyrite in aqueous solution is given, and the essential roles of the precursors elemental sulfur and ``FeS`` in pyrite formation are investigated. In Chapter 5, the formation of iron sulfide complex prior to the precipitation of FeS or FeS{sub 2} is investigated using a fast kinetics technique based on a stopped-flow spectrophotometer. The stoichiometry of the iron sulfide complex is determined, and the rate and formation constants are also evaluated. Chapter 6 provides a summary of the semiconductor properties of pyrite relevant to the present study. In Chapters 7 and 8, the effects of the semiconductor properties on pyrite dissolution are investigated experimentally and the mechanism of pyrite dissolution in acidic aqueous solution is examined. Finally, a summary of the conclusions from this study and suggestions for future research are presented in Chapter 9.

Spectral Induced Polarization of Disseminated Pyrite Particles in Soil

Science.gov (United States)

Slater, L. D.; Kessouri, P.; Seleznev, N. V.

2017-12-01

Disseminated metallic particles in soil, particularly pyrite, occur naturally or are enhanced by anthropogenic activities. Detecting their presence and quantifying their concentration and location is of interest for numerous applications such as remediation of hydrocarbon contamination, mine tailings assessment, detection of oil traps, and archaeological studies. Because pyrite is a semiconductor, spectral induced polarization (SIP) is a promising geophysical method for sensing it in porous media. Previous studies have identified relations between pyrite properties (e.g., volumetric content, grain size) and SIP parameters (e.g., chargeability, relaxation time). However, the effect of pyrite grains in porous media on the SIP response is not fully understood over the entire low-frequency range. We tested the relationship between the presence of pyrite grains and the change in electrical properties of the medium through an extended series of laboratory measurements: (1) variation of grain size, (2) variation of grain concentration, (3) variation of electrolyte conductivity, (4) change in the diffusion properties of the host medium. For the fourth set of measurements, we compared sand columns to agar gel columns. Our experimental design included more than 20 different samples with multiple repeats to ensure representative results. We confirm the strong relation between grain size and relaxation time and that between grain concentration and chargeability in both the sand and agar gel samples. Furthermore, our results shed light on the significance of the diffusion coefficient and the recently hypothesized role of pyrite grains as resistors at frequencies lower than the relaxation frequency.

Iron isotope fractionation during pyrite formation in a sulfidic Precambrian ocean analogue

Science.gov (United States)

Rolison, John M.; Stirling, Claudine H.; Middag, Rob; Gault-Ringold, Melanie; George, Ejin; Rijkenberg, Micha J. A.

2018-04-01

The chemical response of the Precambrian oceans to rising atmospheric O2 levels remains controversial. The iron isotope signature of sedimentary pyrite is widely used to trace the microbial and redox states of the ocean, yet the iron isotope fractionation accompanying pyrite formation in nature is difficult to constrain due to the complexity of the pyrite formation process, difficulties in translating the iron isotope systematics of experimental studies to natural settings, and insufficient iron isotope datasets for natural euxinic (i.e. anoxic and sulfidic) marine basins where pyrite formation occurs. Herein we demonstrate, that a large, permil-level shift in the isotope composition of dissolved iron occurs in the Black Sea euxinic water column during syngenetic pyrite formation. Specifically, iron removal to syngenetic pyrite gives rise to an iron isotope fractionation factor between Fe(II) and FeS2 of 2.75 permil (‰), the largest yet reported for reactions under natural conditions that do not involve iron redox chemistry. These iron isotope systematics offer the potential to generate permil-level shifts in the sedimentary pyrite iron isotope record due to partial drawdown of the oceanic iron inventory. The implication is that the iron stable isotope signatures of sedimentary pyrites may record fundamental regime shifts between pyrite formation under sulfur-limited conditions and pyrite formation under iron-limited conditions. To this end, the iron isotope signatures of sedimentary pyrite may best represent the extent of euxinia in the past global ocean, rather than its oxygenation state. On this basis, the reinterpreted sedimentary pyrite Fe isotope record suggests a fundamental shift towards more sulfidic oceanic conditions coincident with the 'Great Oxidation Event' around 2.3 billion years ago. Importantly, this does not require the chemical state of the ocean to shift from mainly de-oxygenated to predominantly oxygenated in parallel with the permanent rise

Silane-based coatings on the pyrite for remediation of acid mine drainage.

Science.gov (United States)

Diao, Zenghui; Shi, Taihong; Wang, Shizhong; Huang, Xiongfei; Zhang, Tao; Tang, Yetao; Zhang, Xiaying; Qiu, Rongliang

2013-09-01

Acid mine drainage (AMD) resulting from the oxidation of pyrite and other metal sulfides has caused significant environmental problems, including acidification of rivers and streams as well as leaching of toxic metals. With the goal of controlling AMD at the source, we evaluated the potential of tetraethylorthosilicate (TEOS) and n-propyltrimethoxysilane (NPS) coatings to suppress pyrite oxidation. The release of total Fe and SO4(-2) from uncoated and coated pyrite in the presence of a chemical oxidizing agent (H2O2) or iron-oxidizing bacteria (Acidithiobacillus ferrooxidans) was measured. Results showed that TEOS- and NPS-based coatings reduced chemical oxidation of pyrite by as much as 59 and 96% (based on Fe release), respectively, while biological oxidation of pyrite was reduced by 69 and 95%, respectively. These results were attributed to the formation of a dense network of Fe-O-Si and Si-O-Si bonds on the pyrite surface that limited permeation of oxygen, water, and bacteria. Compared with results for TEOS-coated pyrite, higher pH and lower concentrations of total Fe and SO4(-2) were observed for oxidation of NPS-coated pyrite, which was attributed to its crack-free morphology and the presence of hydrophobic groups on the NPS-based coating surface. The silane-based NPS coating was shown to be highly effective in suppressing pyrite oxidation, making it a promising alternative for remediation of AMD at its source. Copyright © 2013 Elsevier Ltd. All rights reserved.

Semiconductor electrochemistry of coal pyrite. Final technical report, September 1990--September 1995

Energy Technology Data Exchange (ETDEWEB)

Osseo-Asare, K.; Wei, D.

1996-01-01

This project is concerned with the physiochemical processes occuring at the pyrite/aqueous interface, in the context of coal cleaning, desulfurization, and acid mine drainage. The use of synthetic particles of pyrite as model electrodes to investigate the semiconductor electrochemistry of pyrite is employed.

Modelling the reactive-path between pyrite and radioactive nuclides

International Nuclear Information System (INIS)

Kang Mingliang; Wu Shijun; Dou Shunmei; Chen Fanrong; Yang Yongqiang

2008-01-01

The mobility of redox sensitive nuclides is largely dependent on their valence state. The radionuclides that make the dominant contributions to final dose calculations are redox sensitive. Almost all the radionuclides (except 129 I) have higher mobility at high valence state, and correspond to immobilization at low valence state due to the much lower solubility. Pyrite is an ubiquitous and stable mineral in geological environment, and would be used as a low-cost long time reductant for the immobilization of radionuclides. However, pyrite oxidation is supposed to generate acid, which will enhance the mobility of nuclides. In this paper, the reaction path of the reactions between radionuclides (U, Se and Tc) and pyrite in the groundwater from Wuyi well in Beishan area of China has been simulated using geochemical modeling software. According to the results, pyrite can reduce high valence nuclides to a dinky-level effectively, with the pH slightly increasing under anaerobic condition that is common in deep nuclear waste repositories. (authors)

Practical considerations of pyrite oxidation control in uranium tailings

International Nuclear Information System (INIS)

1984-05-01

The problems posed by the oxidation of pyrite in uranium tailings include the generation of sulfuric acid and acid sulfate metal salts. These have substantial negative impacts on watercourse biota by themselves, and the lowered pH levels tend to mobilize heavy metals present in the tailings the rate of oxidation of pyrite at lower pH levels is catalyzed by sulfur and iron oxidizing bacteria present in soils. No single clear solution to the problems came from this study. Exclusion of air is a most important preventative of bacterial catalysis of oxidation. Bactericides, chemically breaking the chain of integrated oxidation reactions, maintaining anaerobic conditions, or maintaining a neutral or alkaline pH all reduce the oxidation rate. Removal of pyrite by flotation will reduce but not eliminate the impact of pyrite oxidation. Controlled oxidation of the remaining sulfide in the flotation tails would provide an innocuous tailing so far as acidity generation is concerned

Recrystallization Experiments of Pyrite From Circulating Hydrothermal Solution by Thermal Convection

Science.gov (United States)

Tanaka, K.; Isobe, H.

2005-12-01

Pyrite is one of the most common accessory minerals in many rocks and generally occurs in hydrothermal deposit. However, pyrite morphology and association with other sulfide minerals is not well known with respect to the solution condition, especially with the hydrothermal solution under circulation. In this study, recrystallization experiments of pyrite from circulating hydrothermal solution by thermal convection were carried out. A rectangular circuit (42.6 cm by 17.3 cm) of SUS316 pressure tubing with 5 mm in inner diameter was used as a reaction vessel. The volume of the circuit is approximately 24 ml. Long sides of the rectangular circuit were held to be 20 degrees inclination. One of the long sides was heated by an electric furnace. Solution in the circuit evaporates in the high temperature tubing and the vapor condenses in room temperature tubing. The solution backs to the bottom of the high temperature tubing. Thus, thermal convection of the solution produces circulation in the circuit. Starting material was filled in the high temperature tubing. The lower half was filled with mixture of 2 g of powdered natural pyrite and 4 g of quartz grains. The upper half was filled with quartz grains only. 9 ml of 5 mol/l NH4Cl solution was sealed in the circuit with the starting material. Temperature gradient of the sample was monitored by 6 thermocouples. Maximum temperature was controlled at 350°C. Experimental durations are 3, 5, 10 and 30 days. After the experiments, the run products are fixed with resin and cut every 2 cm. Thin sections of vertical cross-sections are made and observed by microscope and SEM. Tiny pyrite crystals occurred at the upper outside of the furnace, where temperature should be much lower than 200°C. In the lower half of the starting material, pyrite decomposed and pyrrhotite formed around pyrite grains. At higher temperature area, pyrite decomposition and pyrrhotite formation is remarkable. Circulating sulfur-bearing solution provided by

Enhanced bioleaching on attachment of indigenous acidophilic bacteria to pyrite surface

Science.gov (United States)

Wi, D. W.; Cho, K. H.; Kim, B. J.; Choi, N. C.; Park, C. Y.

2012-04-01

In recent years, bioleaching has been widely applied on an industrial scale due to the advantages of low cost and environment friendliness. The direct contact mechanism of bioleaching assumes the action of a metal sulfide-attached cell oxidizing the mineral by an enzyme system with oxygen to sulfate and metal cations. Fundamental surface properties of sulfide particles and leaching-bacteria in bioleaching play the key role in the efficiency of this process. The aim of this work is to investigate of direct contact bioleaching mechanism on pyrite through attachment properties between indigenous acidophilic bacteria and pyrite surfaces. The bacteria were obtained from sulfur hot springs, Hatchobaru thermal electricity plant in Japan. And pyrite was collected from mine waste from Gwang-yang abandoned gold mines, Korea. In XRD analyses of the pyrite, x-ray diffracted d-value belong to pyrite was observed. The indigenous acidophilic bacteria grew well in a solution and over the course of incubation pH decreased and Eh increased. In relation to a bacterial growth-curve, the lag phase was hardly shown while the exponential phase was very fast. Bioleaching experiment result was showed that twenty days after the indigenous acidophilic bacteria were inoculated to a pyrite-leaching medium, the bacterial sample had a greater concentration of Fe and Zn than within the control sample. In SEM-EDS analyses, rod-shaped bacteria and round-shaped microbes were well attached to the surface of pyrite. The size of the rod-shaped bacteria ranged from 1.05~1.10 ? to 4.01~5.38 ?. Round-shaped microbes were more than 3.0 ? in diameter. Paired cells of rod-shaped bacteria were attached to the surface of pyrite linearly.

Spectroscopic study of cystine adsorption on pyrite surface: From vacuum to solution conditions

Energy Technology Data Exchange (ETDEWEB)

Sanchez-Arenillas, M.; Mateo-Marti, E., E-mail: mateome@cab.inta-csic.es

2015-09-08

Highlights: • Successful adsorption of cystine on pyrite surface under several conditions. • Detailed XPS spectroscopic characterization of cystine adsorption on pyrite surface. • Spectroscopy evidence, oxidation and anoxic conditions adjust molecular adsorption. • Molecular chemistry on pyrite is driven depending on the surrounding conditions. • The cystine/pyrite(100) model is in good agreement with Wächtershäuser’s theory. - Abstract: We characterized the adsorption of cystine molecules on pyrite surface via X-ray photoelectron spectroscopy. Anoxic conditions were simulated under ultra-high-vacuum conditions. In contrast, to simulate oxidation conditions, the molecules were adsorbed on pyrite surface from solution. A novel comparative analysis revealed remarkable differences with respect to molecular adsorption and surface chemistry induced by environmental conditions. Molecular adsorption under anoxic conditions was observed to be more favorable, concentrating a large number of molecules on the surface and two different chemical species. In contrast, the presence of oxygen induced an autocatalytic oxidation process on the pyrite surface, which facilitated water binding on pyrite surface and partially blocked molecular adsorption. Pyrite is a highly reactive surface and contains two crucial types of surface functional groups that drive molecular chemistry on the surface depending on the surrounding conditions. Therefore, the system explored in this study holds interesting implications for supporting catalyzed prebiotic chemistry reactions.

Spectroscopic study of cystine adsorption on pyrite surface: From vacuum to solution conditions

International Nuclear Information System (INIS)

Sanchez-Arenillas, M.; Mateo-Marti, E.

2015-01-01

Highlights: • Successful adsorption of cystine on pyrite surface under several conditions. • Detailed XPS spectroscopic characterization of cystine adsorption on pyrite surface. • Spectroscopy evidence, oxidation and anoxic conditions adjust molecular adsorption. • Molecular chemistry on pyrite is driven depending on the surrounding conditions. • The cystine/pyrite(100) model is in good agreement with Wächtershäuser’s theory. - Abstract: We characterized the adsorption of cystine molecules on pyrite surface via X-ray photoelectron spectroscopy. Anoxic conditions were simulated under ultra-high-vacuum conditions. In contrast, to simulate oxidation conditions, the molecules were adsorbed on pyrite surface from solution. A novel comparative analysis revealed remarkable differences with respect to molecular adsorption and surface chemistry induced by environmental conditions. Molecular adsorption under anoxic conditions was observed to be more favorable, concentrating a large number of molecules on the surface and two different chemical species. In contrast, the presence of oxygen induced an autocatalytic oxidation process on the pyrite surface, which facilitated water binding on pyrite surface and partially blocked molecular adsorption. Pyrite is a highly reactive surface and contains two crucial types of surface functional groups that drive molecular chemistry on the surface depending on the surrounding conditions. Therefore, the system explored in this study holds interesting implications for supporting catalyzed prebiotic chemistry reactions

Particulate Pyrite Autotrophic Denitrification (PPAD) for Remediation of Nitrate-contaminated Groundwater

Science.gov (United States)

Tong, S.; Rodriguez-Gonzalez, L. C.; Henderson, M.; Feng, C.; Ergas, S. J.

2015-12-01

The rapid movement of human civilization towards urbanization, industrialization, and increased agricultural activities has introduced a large amount of nitrate into groundwater. Nitrate is a toxic substance discharged from groundwater to rivers and leads to decreased dissolved oxygen and eutrophication. For this experiment, an electron donor is needed to convert nitrate into non-toxic nitrogen gas. Pyrite is one of the most abundant minerals in the earth's crust making it an ideal candidate as an electron donor. The overall goal of this research was to investigate the potential for pyrite to be utilized as an electron donor for autotrophic denitrification of nitrate-contaminated groundwater. Batch studies of particulate pyrite autotrophic denitrification (PPAD) of synthetic groundwater (100 mg NO3--N L-1) were set up with varying biomass concentration, pyrite dose, and pyrite particle size. Reactors were seeded with mixed liquor volatile suspended solids (VSS) from a biological nitrogen removal wastewater treatment facility. PPAD using small pyrite particles (exhibited substantial nitrate removal rate, lower sulfate accumulation (5.46 mg SO42-/mg NO3--N) and lower alkalinity consumption (1.70 mg CaCO3/mg NO3--N) when compared to SOD (7.54 mg SO42-/mg NO3--N, 4.57 mg CaCO3/mg NO3--N based on stoichiometric calculation). This research revealed that the PPAD process is a promising technique for nitrate-contaminated groundwater treatment and promoted the utilization of pyrite in the field of environmental remediation.

Savannah River Plant environment

International Nuclear Information System (INIS)

Dukes, E.K.

1984-03-01

On June 20, 1972, the Atomic Energy Commission designated 192,323 acres of land near Aiken, SC, as the nation's first National Environmental Research Park. The designated land surrounds the Department of Energy's Savannah River Plant production complex. The site, which borders the Savannah River for 17 miles, includes swampland, pine forests, abandoned town sites, a large man-made lake for cooling water impoundment, fields, streams, and watersheds. This report is a description of the geological, hydrological, meteorological, and biological characteristics of the Savannah River Plant site and is intended as a source of information for those interested in environmental research at the site. 165 references, 68 figures, 52 tables

The role of sulfur-oxidizing bacteria Thiobacillus thiooxidans in pyrite weathering

International Nuclear Information System (INIS)

Sasaki, K.; Tsunekawa, M.; Ohtsuka, T.; Konno, H.

1998-01-01

The paper investigates the role of the sulfur-oxidizing bacteria Thiobacillus thiooxidans in pyrite weathering in order to clarify the effects of the bacteria on the dissolution behavior of pyrite and the formation of secondary minerals using Raman spectroscopy and powder X-ray diffraction (XRD) in addition to solution analysis. It was found that T. thiooxidans, when present with the iron-oxidizing bacteria Thiobacillus ferrooxidans, enhanced the dissolution of Fe and S species for pyrite, whereas T. thiooxidans alone did not oxidize pyrite. Enhancement of the consumption of elemental sulfur and regeneration of Fe(II) ions were also observed with T. thiooxidans together with T. ferrooxidans, while this did not occur with T. ferrooxidans alone

Mechanisms of interaction between arsenian pyrite and aqueous arsenite under anoxic and oxic conditions

Science.gov (United States)

Qiu, Guohong; Gao, Tianyu; Hong, Jun; Luo, Yao; Liu, Lihu; Tan, Wenfeng; Liu, Fan

2018-05-01

Pyrite affects the conversion and migration processes of arsenic in soils and waters. Adsorption and redox reactions of arsenite (As(III)) occur on the surface of pyrite, and the interaction processes are influenced by the arsenic incorporated into pyrite. This work examined the effects of arsenic content, pH and oxygen on the interaction between arsenian pyrite and aqueous As(III) and investigated the underlying mechanisms. The results indicated that arsenic incorporation led to a high content of Fe(III) in pyrite, and that As(III) was mainly adsorbed on pyrite surface and part of As(III) was oxidized to As(V) by the newly formed intermediates including hydroxyl radicals and hydrogen peroxide. The oxidation rate increased with increasing arsenic content in the pyrite and the presence of air (oxygen), and first decreased and then increased with increasing pH from 3.0 to 11.0. Hydroxyl radicals and hydrogen peroxide significantly contributed to the oxidation of pyrite and aqueous As(III) in acidic and alkaline solutions, respectively. Although pyrite oxidation increased with increasing arsenic content as indicated by the elevated concentrations of elemental S and SO42-, the percentage of released arsenic in total arsenic of the arsenian pyrite decreased due to the adsorption of arsenic on the surface of newly formed ferric (hydr)oxides, especially the ferric arsenate precipitate formed in high pH solutions. The present study enables a better understanding of the important interaction process of dissolved arsenite and natural pyrites in the study of groundwater contamination, arsenic migration/sequestration, and acid mine drainage formation.

Thermal stability and mechanism of decomposition of emulsion explosives in the presence of pyrite

International Nuclear Information System (INIS)

Xu, Zhi-Xiang; Wang, Qian; Fu, Xiao-Qi

2015-01-01

Highlights: • An exothermic reaction occurs at about 200 °C between pyrite and ammonium nitrate (emulsion explosives). • The essence of reaction between emulsion explosives and pyrite is reaction between ammonium nitrate and pyrite. • The excellent thermal stability of emulsion explosives does not mean it was also showed when pyrite was added. • A new overall reaction has been proposed as: • 14FeS_2(s) + 91NH_4NO_3(s) → 52NO(g) + 26SO_2(g) + 6Fe_2O_3(s) + 78NH_3(g) + 26N_2O(g) + 2FeSO_4(s) + 65H_2O(g). - Abstract: The reaction of emulsion explosives (ammonium nitrate) with pyrite was studied using techniques of TG-DTG-DTA. TG–DSC–MS was also used to analyze samples thermal decomposition process. When a mixture of pyrite and emulsion explosives was heated at a constant heating rate of 10 K/min from room temperature to 350 °C, exothermic reactions occurred at about 200 °C. The essence of reaction between emulsion explosives and pyrite is the reaction between ammonium nitrate and pyrite. Emulsion explosives have excellent thermal stability but it does not mean it showed the same excellent thermal stability when pyrite was added. Package emulsion explosives were more suitable to use in pyrite shale than bulk emulsion explosives. The exothermic reaction was considered to take place between ammonium nitrate and pyrite where NO, NO_2, NH_3, SO_2 and N_2O gases were produced. Based on the analysis of the gaseous, a new overall reaction was proposed, which was thermodynamically favorable. The results have significant implication in the understanding of stability of emulsion explosives in reactive mining grounds containing pyrite minerals.

Thermal stability and mechanism of decomposition of emulsion explosives in the presence of pyrite

Energy Technology Data Exchange (ETDEWEB)

Xu, Zhi-Xiang; Wang, Qian [School of Energy and Power Engineering, Jiangsu University, Zhenjiang 212013 (China); Fu, Xiao-Qi, E-mail: xzx19820708@163.com [School of Chemistry and Chemical Engineering, Jiangsu University Zhenjiang 212013 (China)

2015-12-30

Highlights: • An exothermic reaction occurs at about 200 °C between pyrite and ammonium nitrate (emulsion explosives). • The essence of reaction between emulsion explosives and pyrite is reaction between ammonium nitrate and pyrite. • The excellent thermal stability of emulsion explosives does not mean it was also showed when pyrite was added. • A new overall reaction has been proposed as: • 14FeS{sub 2}(s) + 91NH{sub 4}NO{sub 3}(s) → 52NO(g) + 26SO{sub 2}(g) + 6Fe{sub 2}O{sub 3}(s) + 78NH{sub 3}(g) + 26N{sub 2}O(g) + 2FeSO{sub 4}(s) + 65H{sub 2}O(g). - Abstract: The reaction of emulsion explosives (ammonium nitrate) with pyrite was studied using techniques of TG-DTG-DTA. TG–DSC–MS was also used to analyze samples thermal decomposition process. When a mixture of pyrite and emulsion explosives was heated at a constant heating rate of 10 K/min from room temperature to 350 °C, exothermic reactions occurred at about 200 °C. The essence of reaction between emulsion explosives and pyrite is the reaction between ammonium nitrate and pyrite. Emulsion explosives have excellent thermal stability but it does not mean it showed the same excellent thermal stability when pyrite was added. Package emulsion explosives were more suitable to use in pyrite shale than bulk emulsion explosives. The exothermic reaction was considered to take place between ammonium nitrate and pyrite where NO, NO{sub 2}, NH{sub 3}, SO{sub 2} and N{sub 2}O gases were produced. Based on the analysis of the gaseous, a new overall reaction was proposed, which was thermodynamically favorable. The results have significant implication in the understanding of stability of emulsion explosives in reactive mining grounds containing pyrite minerals.

The determination of uranium in pyrite samples

International Nuclear Information System (INIS)

Jacobs, J.J.

1979-01-01

An existing method for the determination of uranium in rocks and minerals is examined for the determination of uranium in materials containing pyrite. The results are comparable with those obtained by a spectrophotometric method, the precision (relative standard deviation) of the method for standards with U 3 O 8 contents of 1500 and 300 p.p.m. being 0,03 and 0,08 respectively when prepared in pyrite, and 0,15 and 0,06 respectively when made up with inert diluent. Full details of the procedure are given in accompanying appendices [af

Pyrite sulfur isotopes reveal glacial-interglacial environmental changes

Science.gov (United States)

Pasquier, Virgil; Sansjofre, Pierre; Rabineau, Marina; Revillon, Sidonie; Houghton, Jennifer; Fike, David A.

2017-06-01

The sulfur biogeochemical cycle plays a key role in regulating Earth’s surface redox through diverse abiotic and biological reactions that have distinctive stable isotopic fractionations. As such, variations in the sulfur isotopic composition (δ34S) of sedimentary sulfate and sulfide phases over Earth history can be used to infer substantive changes to the Earth’s surface environment, including the rise of atmospheric oxygen. Such inferences assume that individual δ34S records reflect temporal changes in the global sulfur cycle; this assumption may be well grounded for sulfate-bearing minerals but is less well established for pyrite-based records. Here, we investigate alternative controls on the sedimentary sulfur isotopic composition of marine pyrite by examining a 300-m drill core of Mediterranean sediments deposited over the past 500,000 y and spanning the last five glacial-interglacial periods. Because this interval is far shorter than the residence time of marine sulfate, any change in the sulfur isotopic record preserved in pyrite (δ34Spyr) necessarily corresponds to local environmental changes. The stratigraphic variations (>76‰) in the isotopic data reported here are among the largest ever observed in pyrite, and are in phase with glacial-interglacial sea level and temperature changes. In this case, the dominant control appears to be glacial-interglacial variations in sedimentation rates. These results suggest that there exist important but previously overlooked depositional controls on sedimentary sulfur isotope records, especially associated with intervals of substantial sea level change. This work provides an important perspective on the origin of variability in such records and suggests meaningful paleoenvironmental information can be derived from pyrite δ34S records.

Ichthyoplankton entrainment study at the SRS Savannah River water intakes for Westinghouse Savannah River Company

International Nuclear Information System (INIS)

Paller, M.

1992-01-01

Cooling water for L and K Reactors and makeup water for Par Pond is pumped from the Savannah River at the 1G, 3G, and 5G pump houses. Ichthyoplankton (drifting fish larvae and eggs) from the river are entrained into the reactor cooling systems with the river water and passed through the reactor's heat exchangers where temperatures may reach 70 degrees C during full power operation. Ichthyoplankton mortality under such conditions is assumed to be 100 percent. The number of ichthyoplankton entrained into the cooling system depends on a variety of variables, including time of year, density and distribution of ichthyoplankton in the river, discharge levels in the river, and the volume of water withdrawn by the pumps. Entrainment at the 1 G pump house, which is immediately downstream from the confluence of Upper Three Runs Creek and the Savannah River, is also influenced by discharge rates and ichthyoplankton densities in Upper Three Runs Creek. Because of the anticipated restart of several SRS reactors and the growing concern surrounding striped bass and American shad stocks in the Savannah River, the Department of Energy requested that the Environmental Sciences Section (ESS) of the Savannah River Laboratory sample ichthyoplankton at the SRS Savannah River intakes. Dams ampersand Moore, Inc., under a contract with Westinghouse Savannah River Company performed the sampling and data analysis for the ESS

Action time effect of lime on its depressive ability for pyrite

Institute of Scientific and Technical Information of China (English)

Tichang Sun

2004-01-01

Two sample groups of bulk concentrates consisting mainly of pyrite and chalcopyrite from Daye and Chenghchao Mines in Hubei Province of China were used to investigate the effect of the action time of lime on its depressive ability for pyrite. The experimental results conducted with different samples and collectors showed that the action time between lime and pyrite markedly influences the depressive ability of lime. The depressive ability of lime increased with the action time increasing. It was also proved that the depressive results obtained at a large lime dosage after a shorter action time are similar to those obtained at a small lime dosage after a longer action time. The increase of depressive ability of lime after a longer action time is because that there are different mechanisms in different action time. The composition on the surface of pyrite acted for different time with lime was studied by using ESCA (Electron Spectroscopic Chemical Analysis). The results showed that iron hydroxide and calcium sulphate formed on the pyrite surface at the presence of lime in the pulp but the amounts of iron hydroxide and calcium sulphate were different at different action time. At the beginning action time the compound formed on the pyrite surface was mainly calcium sulphate and almost no iron hydroxide formed; but with the action time increasing, iron hydroxide formed. The longer the action time, the more iron hydroxide and the less calcium sulphate formed. It was considered that the stronger depressive ability of lime after a longer action time is because more iron hydroxide forms on the pyrite surface.

Sulfur isotope evidence for the contemporary formation of pyrite in a coastal acid sulfate soil

International Nuclear Information System (INIS)

Bush, R.T.; Sullivan, L.A.; Prince, K.; White, I.

2000-01-01

The sulfur isotopic composition of pyrite (FeS 2 ), greigite (Fe 3 S 4 ) and pore-water sulfate was determined for a typical coastal acid sulfate soil (ASS). Greigite occurs only in the partially oxidised upper-most pyrite sediments as blackish clusters within vertical fissures and other macro-pores. The concentration of pyrite was an order of magnitude greater than greigite in this layer, continuing through the underlying reduced estuarine sediments. δ 34 S of pyrite (0.45 per mil) associated with greigite accumulations were distinctly different to the bulk average for pyrite (-3.7 per mil), but similar to greigite (0.9 per mil). Greigite is meta-stable under reducing conditions, readily transforming to pyrite. The transformation of iron monosulfides (including greigite) to pyrite is a sulfur-isotope conservative process and therefore, these observations indicate that pyrite is forming from greigite at the oxic/anoxic boundary

Hydrogeologic and environmental impact of amjhore pyrite mines, India

Science.gov (United States)

Choubey, Vishnu D.; Rawat, Rajendra K.

1991-01-01

Drainage from active and inactive pyrite mines has produced chemical and physical pollution of both ground- and surface water in Amjhore region. In the present case, chemical pollution is caused by exposing pyrite minerals to oxidation or leaching, resulting in undesirable concentrations of dissolved materials. Pyrite mining suddenly exposed large quantities of sulfides to direct contact with oxygen, and oxidation proceeds rapidly, resulting in acidity and release of metal (Fe) and sulfates to the water system, eventually resulting in water pollution in the region. The magnitude and impact of the problem is just being recognized and, as the present and the future projected demand for clean water is of top priority, the present studies were undertaken. Mine drainage includes water flowing from the surface and underground mines and runoff or seepage from the pyrite mines. This article describes the various hydrologic factors that control acid water formation and its transport. The mine drainage is obviously a continuing source of pollution and, therefore, remedial measures mainly consisting of a double-stage limestone-lime treatment technique have been suggested. The present results will be used to develop an alternative and more effective abatement technology to mitigate acid production at the source, namely, the technique of revegetation of the soil cover applied to the waste mine dump material. Water quality change is discussed in detail, with emphasis on acidity formed from exposed pyrite material and on increase in dissolved solids. Preventive and treatment measures are recommended.

Coupled C-S-Fe geochemistry in a rapidly accumulating marine sedimentary system: Diagenetic and depositional implications

Digital Repository Service at National Institute of Oceanography (India)

Peketi, A.; Mazumdar, A.; Joao, H.M.; Patil, D.J.; Usapkar, A.; Dewangan, P.

on sulfidization Coupled occurrence of ³⁴S-enriched iron sulfide (pyrite) with ¹²C-enriched authigenic carbonate zones is the possible records of paleo-sulfate methane transition zones where AOM-driven-focused sulfate reduction was likely...

Microprobe channeling analysis of pyrite crystals

International Nuclear Information System (INIS)

Jamieson, D.N.; Ryan, C.G.

1992-01-01

Nuclear microprobe analysis has provided much useful information about the composition of microscopic inclusions in minerals, mainly through the use of Particle Induced X-ray Emission (PIXE). However this technique, while powerful, does not provide any direct information about the chemical state, in particular the lattice location, of the elements in the mineral. This information is often of crucial importance in understanding the ore genesis. The technique of ion channeling may be used to identify lattice location, but many minerals occur as microscopic crystals. Therefore it is necessary to utilize a nuclear microprobe with the technique of Channeling Contrast Microscopy (CCM). As many minerals contain interesting trace elements, it is necessary to measure both the yield of backscattered particles and the induced x-rays to get a clear picture of the lattice location of the elements in the crystal. CCM with PIXE was used to analyse natural pyrite crystals containing a variety of substitutional and non-substitutional elements and natural pyrite crystals from a gold bearing ore. In the latter case, evidence was obtained for two habits for Au in the 400 μm crystals: one as inclusions of Au rich minerals, the other substituted on the pyrite lattice sites. 31 refs., 3 tabs., 6 figs

Bacterial leaching of pyritic gold ores

International Nuclear Information System (INIS)

Gagliardi, F.M.; Cashion, J.D.; Brown, J.; Jay, W.H.

1998-01-01

Full text: Pyritic ores (pyrite and arsenopyrite) containing gold concentrations in excess of 50g Au/t can be processed to recover the gold by the removal of the sulphur from the ore. This may be achieved by roasting (producing sulphur dioxide emissions), pressure oxidation (expensive and suitable for large high grade deposits), pressure leaching (still currently being developed) or bacterial oxidation. The bacterial oxidation process is a well known process in nature but has only recently come under investigation as a economically viable and relatively clean method of gold recovery from deep low grade sulphidic ores. Samples were obtained from the Wiluna Gold Mine in Western Australia consisting of the original ore, six successive bacterial reactors and the final products. Moessbauer experiments have been performed at room temperature, liquid nitrogen and liquid helium temperatures, and in applied magnetic fields. The main components of the iron phases which were present during the bacterial treatment were pyrite and arsenopyrite which were readily oxidised by the bacteria. Ferric sulfates and ferric arsenates were identified as by-products of the process with a small amount of the oxyhydroxide goethite. These results are in contrast to the similar study of the Fairview Mine in South Africa where principally Fe(II) species were observed

XAS studies on selenite reduction by pyrite

International Nuclear Information System (INIS)

Kang Mingliang; Liu Chunli; Chen Fanrong; Charlet, Laurnet

2012-01-01

The interaction of aqueous Se (IV) with pyrite were systematically investigated in light of thermodynamic calculations and X-ray Absorption Spectroscopy (XAS). The results from the speciation study reveal that the reduction product is Se (O) when natural pyrite reacts with Se (N) at pH≤5.65, while small amount of FeSeO 3 or iron selenides may be formed at pH 6.1. At pH≥6.94, due to the precipitation of Fe (Ⅲ) -oxyhydroxide, the formation of the thermodynamically most stable species, FeSe 2 , is inhibited. However, when the reactive nanopyrite-greigite was used for reaction, the thermodynamically most stable species, FeSe 2 , was found for the first time as the predominant product in the present study, suggesting that 79 Se can be immobilized in its most insoluble form, FeSe 2 , in Fe (Ⅱ) -sulfide containing environment. This study confirms that pyrite can significantly attenuate the mobility of Se by reductive precipitation, and that the reaction process does not produce protons under acidic or neutral condition when Se (O) is formed. (authors)

Chalcopyrite Dissolution at 650 mV and 750 mV in the Presence of Pyrite

Directory of Open Access Journals (Sweden)

Yubiao Li

2015-08-01

Full Text Available The dissolution of chalcopyrite in association with pyrite in mine waste results in the severe environmental issue of acid and metalliferous drainage (AMD. To better understand chalcopyrite dissolution, and the impact of chalcopyrite’s galvanic interaction with pyrite, chalcopyrite dissolution has been examined at 75 °C, pH 1.0, in the presence of quartz (as an inert mineral and pyrite. The presence of pyrite increased the chalcopyrite dissolution rate by more than five times at Eh of 650 mV (SHE (Cu recovery 2.5 cf. 12% over 132 days due to galvanic interaction between chalcopyrite and pyrite. Dissolution of Cu and Fe was stoichiometric and no pyrite dissolved. Although the chalcopyrite dissolution rate at 750 mV (SHE was approximately four-fold greater (Cu recovery of 45% within 132 days as compared to at 650 mV in the presence of pyrite, the galvanic interaction between chalcopyrite and pyrite was negligible. Approximately all of the sulfur from the leached chalcopyrite was converted to S0 at 750 mV, regardless of the presence of pyrite. At this Eh approximately 60% of the sulfur associated with pyrite dissolution was oxidised to S0 and the remaining 40% was released in soluble forms, e.g., SO42−.

Trace metal pyritization variability in response to mangrove soil aerobic and anaerobic oxidation processes.

Science.gov (United States)

Machado, W; Borrelli, N L; Ferreira, T O; Marques, A G B; Osterrieth, M; Guizan, C

2014-02-15

The degree of iron pyritization (DOP) and degree of trace metal pyritization (DTMP) were evaluated in mangrove soil profiles from an estuarine area located in Rio de Janeiro (SE Brazil). The soil pH was negatively correlated with redox potential (Eh) and positively correlated with DOP and DTMP of some elements (Mn, Cu and Pb), suggesting that pyrite oxidation generated acidity and can affect the importance of pyrite as a trace metal-binding phase, mainly in response to spatial variability in tidal flooding. Besides these aerobic oxidation effects, results from a sequential extraction analyses of reactive phases evidenced that Mn oxidized phase consumption in reaction with pyrite can be also important to determine the pyritization of trace elements. Cumulative effects of these aerobic and anaerobic oxidation processes were evidenced as factors affecting the capacity of mangrove soils to act as a sink for trace metals through pyritization processes. Copyright © 2013 Elsevier Ltd. All rights reserved.

Physics and chemistry of the transition of glass to authigenic minerals: State of Nevada, agency for nuclear projects/nuclear waste project office

International Nuclear Information System (INIS)

Morgenstein, M.E.

1984-11-01

The purpose of this paper is to provide a basic review of the topic of volcanic-glass hydration and the diagenetic formation of authigenic minerals from the hydrated-glass products. The Yucca Mountain Draft Environmental Assessment (DEA) of December 1984 indicates that: most of the available glass in the proximity of the repository horizon has been already hydrated and authigenic minerals which could form have already done so, zeolites could form from as yet unreacted glass during transport of water exiting from the repository, and the zeolites and other authigenic minerals provide sorptive barriers to radionuclide migration. This document surveys the available literature and concludes that the topic appears more complex than as it is treated in the DEA. It is concluded that an insufficient quantity of raw data exists. This paucity of information does not allow the determination of which authigenic minerals (if any) may form from the alteration of volcanic glass in Yucca Mountain; and consequently, radionuclide retardation leading from this reaction process is undeterminable. Appendix A and B contain a critical review of this publication. 29 refs., 6 tabs

Thermal stability and mechanism of decomposition of emulsion explosives in the presence of pyrite.

Science.gov (United States)

Xu, Zhi-Xiang; Wang, Qian; Fu, Xiao-Qi

2015-12-30

The reaction of emulsion explosives (ammonium nitrate) with pyrite was studied using techniques of TG-DTG-DTA. TG-DSC-MS was also used to analyze samples thermal decomposition process. When a mixture of pyrite and emulsion explosives was heated at a constant heating rate of 10K/min from room temperature to 350°C, exothermic reactions occurred at about 200°C. The essence of reaction between emulsion explosives and pyrite is the reaction between ammonium nitrate and pyrite. Emulsion explosives have excellent thermal stability but it does not mean it showed the same excellent thermal stability when pyrite was added. Package emulsion explosives were more suitable to use in pyrite shale than bulk emulsion explosives. The exothermic reaction was considered to take place between ammonium nitrate and pyrite where NO, NO2, NH3, SO2 and N2O gases were produced. Based on the analysis of the gaseous, a new overall reaction was proposed, which was thermodynamically favorable. The results have significant implication in the understanding of stability of emulsion explosives in reactive mining grounds containing pyrite minerals. Copyright © 2015 Elsevier B.V. All rights reserved.

77 FR 19534 - Special Local Regulations; Savannah Tall Ships Challenge, Savannah River, Savannah, GA

Science.gov (United States)

2012-04-02

... Mercado, Marine Safety Unit Savannah Office of Waterways Management, Coast Guard; telephone (912) 652-4353, email Benjamin.Mercado@uscg.mil . If you have questions on viewing the docket, call Renee V. Wright...

Calorimetric investigation on mechanically activated storage energy mechanism of sphalerite and pyrite

International Nuclear Information System (INIS)

Xiao Zhongliang; Chen Qiyuan; Yin Zhoulan; Hu Huiping; Wu Daoxin

2005-01-01

The structural changes of mechanically activated sphalerite and pyrite under different grinding conditions were determined by X-ray powder diffraction (XRD), laser particle size analyzer and elemental analysis. The storage energy of mechanically activated sphalerite and pyrite was measured by a calorimetric method. A thermochemical cycle was designed so that mechanically activated and non-activated minerals reached the same final state when dissolved in the same oxidizing solvent. The results show that the storage energy of mechanically activated sphalerite and pyrite rises with increased in grinding time, and reaches a maximum after a certain grinding period. The storage energy of mechanically activated pyrite decreases when heated under inert atmosphere. The storage energy of mechanically activated sphalerite and pyrite remains constant when treated below 573 K under inert atmosphere. The percentage of the storage energy caused by surface area increase during mechanical activation decreases with increasing grinding time. These results support our opinion that the mechanically activated storage energy of sphalerite is closely related to lattice distortions, and the mechanically activated storage energy of pyrite is mainly caused by the formation of reactive sites on the surface

Waste pyritic coal as a raw material for energetic industry

Energy Technology Data Exchange (ETDEWEB)

Gasiorek, J. [Institute of Inorganic Chemistry, Poznan (Poland). Dept. of Research and Technology

1997-11-01

Results are presented of large laboratory studies on coal desulphurisation with foam flotation method improved by application of bioadsorption of Thiobacillus ferrooxidans bacteria to the modification of superficial properties of pyrite particulates from hydrophobic to hydrophillic ones. Results of coal desulfurization with and without bioadsorption have been compared. Bioadsorption improved pyritic sulfur removal by 30% (for coal from `Sierza mine`, coal size 0.3 to 0.102 mm, S pyritic content 1.69%) after 6-week adaptation of bacteria and 30 min of bioadsorption. Bacteria concentration in 5% water suspension of coal reached 22 {mu}g of biomass cm{sup -3}. 12 refs., 4 figs., 1 tab.

Application of fuel cell for pyrite and heavy metal containing mining waste

Science.gov (United States)

Keum, H.; Ju, W. J.; Jho, E. H.; Nam, K.

2015-12-01

Once pyrite and heavy metal containing mining waste reacts with water and air it produces acid mine drainage (AMD) and leads to the other environmental problems such as contamination of surrounding soils. Pyrite is the major source of AMD and it can be controlled using a biological-electrochemical dissolution method. By enhancing the dissolution of pyrite using fuel cell technology, not only mining waste be beneficially utilized but also be treated at the same time by. As pyrite-containing mining waste is oxidized in the anode of the fuel cell, electrons and protons are generated, and electrons moves through an external load to cathode reducing oxygen to water while protons migrate to cathode through a proton exchange membrane. Iron-oxidizing bacteria such as Acidithiobacillus ferrooxidans, which can utilize Fe as an electron donor promotes pyrite dissolution and hence enhances electrochemical dissolution of pyrite from mining waste. In this study mining waste from a zinc mine in Korea containing 17 wt% pyrite and 9% As was utilized as a fuel for the fuel cell inoculated with A. ferrooxidans. Electrochemically dissolved As content and chemically dissolved As content was compared. With the initial pH of 3.5 at 23℃, the dissolved As concentration increased (from 4.0 to 13 mg/L after 20 d) in the fuel cell, while it kept decreased in the chemical reactor (from 12 to 0.43 mg/L after 20 d). The fuel cell produced 0.09 V of open circuit voltage with the maximum power density of 0.84 mW/m2. Dissolution of As from mining waste was enhanced through electrochemical reaction. Application of fuel cell technology is a novel treatment method for pyrite and heavy metals containing mining waste, and this method is beneficial for mining environment as well as local community of mining areas.

Oxidation state of gold and arsenic in gold-bearing arsenian pyrite

Energy Technology Data Exchange (ETDEWEB)

Simon, G.; Huang, H.; Penner-Hahn, J.E.; Kesler, S.E.; Kao, L.S. [Univ. of Michigan, Ann Arbor, MI (United States)

1999-07-01

XANES measurements on gold-bearing arsenian pyrite from the Twin Creeks Carlin-type gold deposits show that gold is present as both Au{sup 0} and Au{sup 1+} and arsenic is present as As{sup 1{minus}}. Au{sup 0} is attributed to sub-micrometer size inclusions of free gold, whereas Au{sup 1+} is attributed to gold in the lattice of the arsenian pyrite. STEM observations suggest that As{sup 1{minus}} is probably concentrated in angstrom-scale, randomly distributed layers with a marcasite or arsenopyrite structure. Ionic gold (Au{sup 1+}) could be concentrated in these layers as well, and is present in both twofold- and fourfold-coordinated forms, with fourfold-coordinated Au{sup 1+} more abundant. Twofold-coordinated Au{sup 1+} is similar to gold in Au{sub 2}S in which it is linearly coordinated to two sulfur atoms. The nature of fourfold-coordinated Au{sup 1+} is not well understood, although it might be present as an Au-As-S compound where gold is bonded in fourfold coordination to sulfur and arsenic atoms, or in vacancy positions on a cation site in the arsenian pyrite. Au{sup 1+} was probably incorporated into arsenian pyrite by adsorption onto pyrite surfaces during crystal growth. The most likely compound in the case of twofold-coordinated Au{sup 1+} was probably a tri-atomic surface complex such as S{sub pyrite}-Au{sup 1+}-S{sub bi-sulfide}H or Au{sup 1+}-S-Au{sup 1+}. The correlation between gold and arsenic might be related to the role of arsenic in enhancing the adsorption of gold complexes of this type on pyrite surfaces, possibly through semiconductor effects.

Effect of inversion layer at iron pyrite surface on photovoltaic device

Science.gov (United States)

Uchiyama, Shunsuke; Ishikawa, Yasuaki; Uraoka, Yukiharu

2018-03-01

Iron pyrite has great potential as a thin-film solar cell material because it has high optical absorption, low cost, and is earth-abundant. However, previously reported iron pyrite solar cells showed poor photovoltaic characteristics. Here, we have numerically simulated its photovoltaic characteristics and band structures by utilizing a two-dimensional (2D) device simulator, ATLAS, to evaluate the effects of an inversion layer at the surface and a high density of deep donor defect states in the bulk. We found that previous device structures did not consider the inversion layer at the surface region of iron pyrite, which made it difficult to obtain the conversion efficiency. Therefore, we remodeled the device structure and suggested that removing the inversion layer and reducing the density of deep donor defect states would lead to a high conversion efficiency of iron pyrite solar cells.

Pyrite oxidation in unsaturated aquifer sediments. Reaction stoichiometry and rate of oxidation

DEFF Research Database (Denmark)

Andersen, Martin Søgaard; Larsen, Flemming; Postma, Diederik Jan

2001-01-01

The oxidation of pyrite (FeS2) contained in unsaturated aquifer sediment was studied by sediment incubation in gas impermeable polymer laminate bags. Reaction progress was followed over a period of nearly 2 months by monitoring the gas composition within the laminate bag. The gas phase in the inc......The oxidation of pyrite (FeS2) contained in unsaturated aquifer sediment was studied by sediment incubation in gas impermeable polymer laminate bags. Reaction progress was followed over a period of nearly 2 months by monitoring the gas composition within the laminate bag. The gas phase...... in the incubation bags became depleted in O2 and enriched in CO2 and N2 and was interpreted as due to pyrite oxidation in combination with calcite dissolution. Sediment incubation provides a new method to estimate low rates of pyrite oxidation in unsaturated zone aquifer sediments. Oxidation rates of up to 9.4â10......-10 mol FeS2/gâs are measured, and the rates are only weakly correlated with the sediment pyrite content. The reactivity of pyrite, including the inhibition by FeOOH layers formed on its surface, apparently has a major effect on the rate of oxidation. The code PHREEQC 2.0 was used to calculate...

Savannah River Site Environmental Implentation Plan

International Nuclear Information System (INIS)

1989-01-01

This report describes the organizational responsibilities for the Savannah River Site Environmental program. Operations, Engineering and projects, Environment, safety, and health, Quality assurance, and the Savannah River Laboratory are described

Savannah River Plant/Savannah River Laboratory radiation exposure report

International Nuclear Information System (INIS)

Rogers, C.D.; Hyman, S.D.; Keisler, L.L.; Reeder, D.F.; Jolly, L.; Spoerner, M.T.; Schramm, G.R.

1989-01-01

The protection of worker health and safety is of paramount concern at the Savannah River Site. Since the site is one of the largest nuclear sites in the nation, radiation safety is a key element in the protection program. This report is a compendium of the results in 1988 of the programs at the Savannah River Plant and the Savannah River Laboratory to protect the radiological health of employees. By any measure, the radiation protection performance at this site in 1988 was the best since the beginning of operations. This accomplishment was made possible by the commitment and support at all levels of the organizations to reduce radiation exposures to ALARA (As Low As Reasonably Achievable). The report provides detailed information about the radiation doses received by departments and work groups within these organizations. It also includes exposure data for recent years to allow Plant and Laboratory units to track the effectiveness of their ALARA efforts. Many of the successful practices and methods that reduced radiation exposure are described. A new goal for personnel contamination cases has been established for 1989. Only through continual and innovative efforts to minimize exposures can the goals be met. The radiation protection goals for 1989 and previous years are included in the report. 27 figs., 58 tabs

Lipid biomarkers preserved in hydrate-associated authigenic carbonate rocks of the Gulf of Mexico

NARCIS (Netherlands)

Pancost, R.D.; Zhang, C.L.; Tavacoli, J.; Talbot, H.M.; Farrimond, P.; Schouten, S.; Sinninghe Damsté, J.S.; Sassen, R.

2005-01-01

Anaerobic oxidation of methane (AOM) is common in ocean-margin sediments, where it is mediated by consortia of Archaea and Bacteria and can result in the formation of authigenic carbonate, including extensive carbonate crusts. Previous work indicates that AOM is associated with Gulf of Mexico

The mechanisms of pyrite oxidation and leaching: A fundamental perspective

Science.gov (United States)

Chandra, A. P.; Gerson, A. R.

2010-09-01

Pyrite is the earth's most abundant sulfide mineral. Its frequent undesirable association with minerals of economic value such as sphalerite, chalcopyrite and galena, and precious metals such as gold necessitates costly separation processes such as leaching and flotation. Additionally pyrite oxidation is a major contributor to the environmental problem of acid rock drainage. The surface oxidation reactions of pyrite are therefore important both economically and environmentally. Significant variations in electrical properties resulting from lattice substitution of minor and trace elements into the lattice structure exist between pyrite from different geographical locations. Furthermore the presence of low coordination surface sites as a result of conchoidal fracture causes a reduction in the band gap at the surface compared to the bulk thus adding further electrochemical variability. Given the now general acceptance after decades of research that electrochemistry dominates the oxidation process, the geographical location, elemental composition and semi-conductor type (n or p) of pyrite are important considerations. Aqueous pyrite oxidation results in the production of sulfate and ferrous iron. However other products such as elemental sulfur, polysulfides, hydrogen sulfide, ferric hydroxide, iron oxide and iron(III) oxyhydroxide may also form. Intermediate species such as thiosulfate, sulfite and polythionates are also proposed to occur. Oxidation and leach rates are generally influenced by solution Eh, pH, oxidant type and concentration, hydrodynamics, grain size and surface area in relation to solution volume, temperature and pressure. Of these, solution Eh is most critical as expected for an electrochemically controlled process, and directly correlates with surface area normalised rates. Studies using mixed mineral systems further indicate the importance of electrochemical processes during the oxidation process. Spatially resolved surface characterisation of fresh

The composition of pyrite in volcanogenic massive sulfide deposits as determined with the proton microprobe

International Nuclear Information System (INIS)

Huston, D.L.; Sie, S.H.; Suter, G.F.; Ryan, C.G.

1993-01-01

Pixeprobe analysis of pyrite from Australian volcanogenic massive sulfide (VMS) deposits indicate significant levels of Cu, Zn, Pb, Ba, Ag, Sb, Bi (from inclusions), As, Tl, Mo, Au, In, Cd (from nonstoichiometric substitution), Co, Ni, Se and Te (from stoichiometric substitution). Pyrite in massive sulfide lenses is enriched in trace elements compared to that in the stringer zone owing to hydrothermal recrystallization. Metamorphic recrystallization also 'cleans' pyrite of trace elements. High Au values occur in pyrite with high As content. Pyrite in stringer zones is enriched in Se relative to the overlying massive sulfide lenses and the surrounding alteration zones. (orig.)

Enrichments in authigenic uranium in glacial sediments of the Southern Ocean; Enrichissement en uranium authigene dans les sediments glaciaires de l'ocean Austral

Energy Technology Data Exchange (ETDEWEB)

Dezileau, L. [Universidad de Conception, Programa Regional de Oceanografia Fisica y Climat PROFC, Y Centro de Investigacion Oceanografica (Chile); Bareille, G. [Pau Univ., Lab. de Chimie Analytique Bio-Inorganique et Environnement, EP-CNRS 132, 64 (France); Reyss, J.L. [CEA Saclay, Direction des Sciences de la Matiere, Lab. des Sciences du Climat et de L' environnement, Lab. Mixte CEA-CNRS, 91 - Gif-sur-Yvette (France)

2002-11-01

Four sediment cores from the Polar frontal zone and the Antarctic zone in the Indian sector of the Southern Ocean present an increase of authigenic uranium during glacial periods. We show that this increase in uranium is due to a combination of (i) an increase in the lateral transport of organic matter, (ii) a decrease in the oxygen in deep waters, and (iii) a process of diagenesis. It appears that uranium concentration cannot be used as a proxy of paleo-productivity in the Southern Ocean, as previously suggested by Kumar et al. in 1995. (authors)

Geochemistry of Early Frasnian (Late Devonian) pyrite-ammonoid level in the Kostomłoty Basin, Poland, and a new proxy parameter for assessing the relative amount of syngenetic and diagenetic pyrite

Science.gov (United States)

Pisarzowska, Agnieszka; Berner, Zsolt A.; Racki, Grzegorz

2014-07-01

Pyrite geochemistry (isotope and trace element composition, degree of pyritization, S/Corg ratio) was used in context of selected lithogeochemical parameters (major and trace elements, including sulphur, organic carbon, and δ13C of carbonate carbon) to constrain fluctuations in depositional conditions during the Early to Middle Frasnian carbon isotopic perturbation (punctata Event) in the Kostomłoty Basin, Poland. Based on the ratio between the sum of oxyanionic elements and transition metals in pyrite, a new proxy parameter (index of syngenetic pyrite, ISYP) is proposed for assessing the relative amount of syngenetic pyrite in a sample. The distribution of the ISYP along the Kostomłoty - Małe Górki section (upper Szydłówek to the basal Kostomłoty beds) is in concert with conclusions inferred from paleoecologic data and other geochemical parameters (degree of pyritization, S/Corg, δ34Spyrite). According to these, the lower segment of the Szydłówek Beds was deposited in a normally oxygenated environment, but undergoing increasing primary productivity in surface water, as indicated by an increase in δ13Ccarb and in Cu/Zr ratio in bulk rock, which triggered the periodic deposition of sediments slightly enriched in organic matter, notably within the pyrite-ammonoid level (= Goniatite Level). Fluctuating, but in general high S/Corg ratios, DOPR values and ISYP values suggest that during this time - against the background of a generally dysoxic environment - shorter or longer lasting episodes of more restricted (anoxic and possibly even euxinic) bottom water conditions developed. Low sedimentation rates enabled a continuous and practically unlimited supply of sulphate during bacterial sulphate reduction (BSR), which in turn led to a strong depletion of pyrite sulphur in 34S in this interval (constantly around -29‰). In contrast, below and above the Goniatite Level, higher δ34S values (up to + 3‰), are compatible with closed system conditions and higher

Lattice location of gold in natural pyrite crystals

International Nuclear Information System (INIS)

Besten, Jacinta den; Jamieson, David N.; Ryan, Chris G.

1999-01-01

The lattice location of gold atoms in naturally occurring Au-doped pyrite crystals has been investigated with a nuclear microprobe using ion channeling. The specimens consisted of 300-μm diameter pyrite crystals in veins embedded in a quartz matrix from the Emperor mine in Fiji. The specimens were prepared by standard geological specimen preparation techniques and the pyrite crystals were analysed in situ in the quartz matrix. Significant trace elements in the crystals, determined by Proton Induced X-ray Emission with a 3 MeV H + microprobe, were Cu, As, Mo, Zn, Te, Au and Pb. The Au concentration was about 0.2 wt%. By the use of 2 MeV He + ion channeling, the Miller indices of the lowest order crystal axes nearest to the normal were determined from backscattering yield maps from two-dimensional angular scanning and comparison of the resulting patterns with published gnomonic projections. Channeling angular yield curves were obtained from Fe, S, As and Au signals. The results indicate that at least 35% of the Au is substituted onto lattice sites

Cu-As Decoupling in Hydrothermal Systems: A Link Between Pyrite Chemistry and Fluid Composition

Science.gov (United States)

Reich, M.; Tardani, D.; Deditius, A.; Chryssoulis, S.; Wrage, J.; Sanchez-Alfaro, P.; Andrea, H.; Cinthia, J.

2016-12-01

Chemical zonations in pyrite have been recognized in most hydrothermal ore deposit types, showing in some cases marked oscillatory alternation of metals and metalloids in pyrite growth zones (e.g., of Cu-rich, As-(Au)-depleted zones and As-(Au)-rich, Cu-depleted zones). This decoupled geochemical behavior of Cu and As has been interpreted as a result of chemical changes in ore-forming fluids, although direct evidence connecting fluctuations in hydrothermal fluid composition with metal partitioning into pyrite growth zones is still lacking. Here we report a comprehensive trace element database of pyrite from an active hydrothermal system, the Tolhuaca Geothermal System (TGS) in southern Chile. We combined high-spatial resolution and X-ray mapping capabilities of electron microprobe analysis (EMPA) with low detection limits and depth-profiling capabilities of secondary-ion mass spectrometry (SIMS) in a suite of pyrite samples retrieved from a 1 km drill hole that crosses the argillic and propylitic alteration zones of the geothermal system. We show that the concentrations of precious metals (e.g., Au, Ag), metalloids (e.g., As, Sb, Se, Te), and base and heavy metals (e.g., Cu, Co, Ni, Pb) in pyrite at the TGS are significant. Among the elements analyzed, arsenic, Cu and Co are the most abundant with concentrations that vary from sub-ppm levels to a few wt. %. Pyrites from the deeper propylitic zone do not show significant zonation and high Cu-(Co)-As concentrations correlate with each other. In contrast, well-developed zonations were detected in pyrite from the shallow argillic alteration zone, where Cu(Co)-rich, As-depleted cores alternate with Cu(Co)-depleted, As-rich rims. These microanalytical data were contrasted with chemical data of fluid inclusion in quartz veins (high Cu/Na and low As/Na) and borehole fluids (low Cu/Na and high As/Na) reported at the TGS, showing a clear correspondence between Cu and As concentrations in pyrite-forming fluids and chemical

Savannah River Site (SRS) environmental overview

International Nuclear Information System (INIS)

O'Rear, M.G.; Steele, J.L.; Kitchen, B.G.

1990-01-01

The environmental surveillance activities at and in the vicinity of the Savannah River Site (SRS) [formerly the Savannah River Plant (SRP)] comprise one of the most comprehensive and extensive environmental monitoring programs in the United States. This overview contains monitoring data from routine and nonroutine radiological and nonradiological environmental surveillance activities, summaries of environmental protection programs in progress, a summary of National Environmental Policy Act (NEPA) activities, and a listing of environmental permits (Appendix A) issued by regulatory agencies. This overview provides information about the impact of SRS operations on the public and the environment. The SRS occupies a large area of approximately 300 square miles along the Savannah River, principally in Aiken and Barnwell counties of South Carolina. SRS's primary function is the production of tritium, plutonium, and other special nuclear materials for national defense, for other governmental uses, and for some civilian purposes. From August 1950 to March 31, 1989, SRS was operated for the Department of Energy (DOE) by E. I. du Pont de Nemours ampersand Co. On April 1, 1989 the Westinghouse Savannah River Company assumed responsibility as the prime contractor for the Savannah River Site

Pyrite deformation and connections to gold mobility: Insight from micro-structural analysis and trace element mapping

Science.gov (United States)

Dubosq, R.; Lawley, C. J. M.; Rogowitz, A.; Schneider, D. A.; Jackson, S.

2018-06-01

The metamorphic transition of pyrite to pyrrhotite results in the liberation of lattice-bound and nano-particulate metals initially hosted within early sulphide minerals. This process forms the basis for the metamorphic-driven Au-upgrading model applied to many orogenic Au deposits, however the role of syn-metamorphic pyrite deformation in controlling the retention and release of Au and related pathfinder elements is poorly understood. The lower amphibolite facies metamorphic mineral assemblage (Act-Bt-Pl-Ep-Alm ± Cal ± Qz ± Ilm; 550 °C) of Canada's giant Detour Lake deposit falls within the range of pressure-temperature conditions (450 °C) for crystal plastic deformation of pyrite. We have applied a complementary approach of electron backscatter diffraction (EBSD) mapping and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) 2D element mapping on pyrite from the Detour Lake deposit. Chemical element maps document an early generation of Au-rich sieve textured pyrite domains and a later stage of syn-metamorphic oscillatory-zoned Au-poor pyrite. Both pyrite types are cut by Au-rich fractures as a consequence of remobilization of Au with trace element enrichment of first-row transition elements, post-transition metals, chalcogens and metalloids during a late brittle deformation stage. However, similar enrichment in trace elements and Au can be observed along low-angle grain boundaries within otherwise Au-poor pyrite, indicating that heterogeneous microstructural misorientation patterns and higher strain domains are also relatively Au-rich. We therefore propose that the close spatial relationship between pyrite and Au at the microscale, features typical of orogenic Au deposits, reflects the entrapment of Au within deformation-induced microstructures in pyrite rather than the release of Au during the metamorphic transition from pyrite to pyrrhotite. Moreover, mass balance calculations at the deposit scale suggest that only a small percentage

Thermoluminescence kinetics of pyrite (FeS2)

International Nuclear Information System (INIS)

Silverman, A.N; Levy, P.W.; Kierstead, J.A.

1990-01-01

Thermoluminescence of pyrite (FeS 2 ) has been investigated to study the kinetics of single peak glow curves. The material used normally exhibits one large and four small peaks. However a glow curve can be obtained with only the large single peak that is suitable for testing thermoluminescence kinetics. Glow curves from aliquots of a single natural pyrite crystal studied in detail contain two low intensity thermoluminescence (TL) peaks at ∼90 degree and ∼250 degree C, and two chemiluminescence (CL) peaks at ∼350 degree and ∼430 degree C. The CL peaks are largely removable by initially heating the sample chamber under vacuum, pumping through liquid nitrogen traps, and recording glow curves immediately after helium is introduced, procedures which reduce system contaminants that react with pyrite. The shape, the variation of the temperature of the peak maximum (T max ) with dose, and the retrapping to recombination cross section ratio σ of the large 250 degree C peak are better described by the general one trap (GOT) kinetic equation, the basic equation from which the 1st and 2nd order kinetic equations are obtained as special cases (see text), than by the 1st and 2nd order equations. 12 refs., 7 figs

The role microbial sulfate reduction in the direct mediation of sedimentary authigenic carbonate precipitation

Science.gov (United States)

Turchyn, A. V.; Walker, K.; Sun, X.

2016-12-01

The majority of modern deep marine sediments are bathed in water that is undersaturated with respect to calcium carbonate. However, within marine sediments changing chemical conditions, driven largely by the microbial oxidation of organic carbon in the absence of oxygen, lead to supersaturated conditions and drive calcium carbonate precipitation. This sedimentary calcium carbonate is often called `authigenic carbonate', and is found in the form of cements and disseminated crystals within the marine sedimentary pile. As this precipitation of this calcium carbonate is microbially mediated, identifying authigenic carbonate within the geological record and understanding what information its geochemical and/or isotopic signature may hold is key for understanding its importance and what information it may contain past life. However, the modern controls on authigenic carbonate precipitation remain enigmatic because the myriad of microbially mediated reactions occurring within sediments both directly and indirectly impact the proton balance. In this submission we present data from 25 ocean sediment cores spanning the globe where we explore the deviation from the stoichiometrically predicted relationships among alkalinity, calcium and sulfate concentrations. In theory for every mol of organic carbon reduced by sulfate, two mol of alkalinity is produced, and to precipitate subsurface calcium carbonate one mol of calcium is used to consume two mol of alkalinity. We use this data with a model to explore changes in carbonate saturation state with depth below the seafloor. Alkalinity changes in the subsurface are poorly correlated with changes in calcium concentrations, however calcium concentrations are directly and tightly coupled to changes in sulfate concentrations in all studied sites. This suggests a direct role for sulfate reducing bacteria in the precipitation of subsurface carbonate cements.

Thermal stability and kinetics of decomposition of ammonium nitrate in the presence of pyrite

International Nuclear Information System (INIS)

Gunawan, Richard; Zhang Dongke

2009-01-01

The interaction between ammonium nitrate based industrial explosives and pyrite-rich minerals in mining operations can lead to the occurrence of spontaneous explosion of the explosives. In an effort to provide a scientific basis for safe applications of industrial explosives in reactive mining grounds containing pyrite, ammonium nitrate decomposition, with and without the presence of pyrite, was studied using a simultaneous Differential Scanning Calorimetry and Thermogravimetric Analyser (DSC-TGA) and a gas-sealed isothermal reactor, respectively. The activation energy and the pre-exponential factor of ammonium nitrate decomposition were determined to be 102.6 kJ mol -1 and 4.55 x 10 7 s -1 without the presence of pyrite and 101.8 kJ mol -1 and 2.57 x 10 9 s -1 with the presence of pyrite. The kinetics of ammonium nitrate decomposition was then used to calculate the critical temperatures for ammonium nitrate decomposition with and without the presence of pyrite, based on the Frank-Kamenetskii model of thermal explosion. It was shown that the presence of pyrite reduces the temperature for, and accelerates the rate of, decomposition of ammonium nitrate. It was further shown that pyrite can significantly reduce the critical temperature of ammonium nitrate decomposition, causing undesired premature detonation of the explosives. The critical temperature also decreases with increasing diameter of the blast holes charged with the explosive. The concept of using the critical temperature as indication of the thermal stability of the explosives to evaluate the risk of spontaneous explosion was verified in the gas-sealed isothermal reactor experiments.

Thermal stability and kinetics of decomposition of ammonium nitrate in the presence of pyrite.

Science.gov (United States)

Gunawan, Richard; Zhang, Dongke

2009-06-15

The interaction between ammonium nitrate based industrial explosives and pyrite-rich minerals in mining operations can lead to the occurrence of spontaneous explosion of the explosives. In an effort to provide a scientific basis for safe applications of industrial explosives in reactive mining grounds containing pyrite, ammonium nitrate decomposition, with and without the presence of pyrite, was studied using a simultaneous Differential Scanning Calorimetry and Thermogravimetric Analyser (DSC-TGA) and a gas-sealed isothermal reactor, respectively. The activation energy and the pre-exponential factor of ammonium nitrate decomposition were determined to be 102.6 kJ mol(-1) and 4.55 x 10(7)s(-1) without the presence of pyrite and 101.8 kJ mol(-1) and 2.57 x 10(9)s(-1) with the presence of pyrite. The kinetics of ammonium nitrate decomposition was then used to calculate the critical temperatures for ammonium nitrate decomposition with and without the presence of pyrite, based on the Frank-Kamenetskii model of thermal explosion. It was shown that the presence of pyrite reduces the temperature for, and accelerates the rate of, decomposition of ammonium nitrate. It was further shown that pyrite can significantly reduce the critical temperature of ammonium nitrate decomposition, causing undesired premature detonation of the explosives. The critical temperature also decreases with increasing diameter of the blast holes charged with the explosive. The concept of using the critical temperature as indication of the thermal stability of the explosives to evaluate the risk of spontaneous explosion was verified in the gas-sealed isothermal reactor experiments.

Flocculation of Pyrite Fines in Aqueous Suspensions with Corn Starch to Eliminate Mechanical Entrainment in Flotation

Directory of Open Access Journals (Sweden)

Wei Ge

2015-10-01

Full Text Available The hydrophilic flocculation of pyrite fines in aqueous suspensions with corn starch was studied by measuring particle size distribution, microscopy observation and micro-flotation. Furthermore, the interaction of corn starch with pyrite was investigated by determining the adsorption density and based on zeta potential measurements and X-ray photoelectron spectrometer (XPS analysis in this work. The results of the particle size distribution measurement show that corn starch can effectively aggregate pyrite fines, and the pyrite floccules (flocs are sensitive to mechanical stirring. The micro-flotation results suggest that the mechanical entrainment of pyrite fines in flotation can be effectively eliminated through the formation of large-size flocs. The zeta potential of pyrite particles decreases with the addition of corn starch. The XPS results prove that carboxyl groups are generated on the digested corn starch, and both iron hydroxyl compounds and ferrous disulfide on the pyrite surface can chemically interact with the corn starch digested by sodium hydroxide.

77 FR 6039 - Special Local Regulations; Savannah Tall Ships Challenge, Savannah River, Savannah, GA

Science.gov (United States)

2012-02-07

..., call or email Chief Petty Officer Benjamin Mercado, Marine Safety Unit Savannah Office of Waterways Management, Coast Guard; telephone (912) 652-4353, email Benjamin.Mercado@uscg.mil . If you have questions on... its provisions or options for compliance, please contact Chief Petty Officer Benjamin Mercado, Marine...

The flotation of gold, uranium, and pyrite from Witwatersrand ores

International Nuclear Information System (INIS)

Lloyd, P.J.D.

1981-01-01

The Witwatersrand reefs contain gold, uranium, and pyrite in the following average concentrations: 0,001 per cent, 0,02 per cent, and 1,7 per cent respectively. The paper discusses the flotation of pyrite to produce a sulphide concentrate, reviews work done on the production of gold concentrates, discusses attempts to produce maximum concentrates, and closes with a review of processes for the simultaneous flotation of these three species. It is concluded that high recoveries of all three species can be achieved only if a rougher concentrate of perhaps 20 per cent of the feed (by mass) is produced, and it is suggested that reverse leaching (leaching before cyanidation) of this concentrate, followed by a cleaning flotation step for the recovery of the pyrite, would be more efficient than the routes employed at present [af

Palaeoredox indicators from the organic-rich Messinian early post-evaporitic deposits of the Apennines (Central Italy)

Science.gov (United States)

Sampalmieri, G.; Iadanza, A.; Cipollari, P.; Cosentino, D.; Lo Mastro, S.

2009-04-01

Bottom redox conditions in marine and lacustrine ancient basins are often inferred by the occurrence of peculiar sedimentological structures and microfaunal assemblages. The co-occurrence, in such environments, of authigenic uranium, framboidal pyrite, barite and Fe-Mn nodules and encrustations, provides a good constraint for palaeo reconstructions. Authigenic uranium is a common constituent of hydrocarbon source rocks: it forms at the sediment-water interface under oxygen-deficient conditions and accumulates together with organic matter (OM). Its precipitation is triggered by the reduction of the soluble U6+ion in seawater to insoluble U4+. With respect to black shales, uranium content has even been used to estimate the TOC. Also authigenic pyrite forms under anoxic conditions and replaces organic matter: 1) the increase in pyrite content and in organic matter are directly correlated; 2) the size distribution of framboidal pyrite (consistent with sulphate-reducing bacterial activity) is considered a measure of redox conditions within the sediment. Barite is an authigenic mineral related to Corg content, since its organic precipitation is triggered by sulphate-reduction processes occurring in decaying OM-bearing microenvironments. Finally, also Fe-Mn oxyhydroxide are typical indicators of redox conditions. About 6 My ago the Mediterranean Sea underwent a giant event of concentration referred to as Messinian Salinity Crisis, which can be roughly subdivided into an evaporitic and a post evaporitic phase. The post evaporitic phase (p-ev; 5.61-5.33 Ma) developed in a context of humid conditions and can be further distinguished into two steps: p-ev1 (early post evaporitic phase) and p-ev2 (late post evaporitic phase). Previous works focused on pev2, which is interpreted to represent the establishment of brackish water conditions (Lago-Mare biofacies). In other respects, the palaeoenvironment of p-ev1 deposits, mostly represented by resedimented evaporitic deposits or

Thermal effects on the Savannah River

International Nuclear Information System (INIS)

Patrick, R.

1981-01-01

The effects of thermal effluents from the Savannah River Plant (SRP), particularly during periods when the L Reactor was operative, on the structure and health of the aquatic communities of organisms in the Savannah River have been determined. Portions of the data base collected by the Academy of Natural Sciences since 1951 on the Savannah River were used. The organisms belonging to various groups of aquatic life were identified to species if possible. The relative abundance of the species was estimated for the more common species. The bacteriological, chemical and physical characteristics of the water were determined

Savannah River waste management program plan

International Nuclear Information System (INIS)

1980-04-01

This document provides the program plan as requested by the Savannah River Operations Office of the Department of Energy. The plan was developed to provide a working knowledge of the nature and extent of the waste management programs being undertaken by Savannah River contractors for the Fiscal Year 1980. In addition, the document projects activities for several years beyond 1980 to adequately plan for safe handling and storage of radioactive wastes generated at Savannah River, for developing technology to immobilize high-level radioactive wastes generated and stored at SR, and for developing technology for improved management of low-level solid wastes

Chemistry and phase evolution during roasting of toxic thallium-bearing pyrite.

Science.gov (United States)

Lopez-Arce, Paula; Garcia-Guinea, Javier; Garrido, Fernando

2017-08-01

In the frame of a research project on microscopic distribution and speciation of geogenic thallium (Tl) from contaminated mine soils, Tl-bearing pyrite ore samples from Riotinto mining district (Huelva, SW Spain) were experimentally fired to simulate a roasting process. Concentration and volatility behavior of Tl and other toxic heavy metals was determined by quantitative ICP-MS, whereas semi-quantitative mineral phase transitions were identified by in situ thermo X-Ray Diffraction (HT-XRD) and Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS) analyses after each firing temperature. Sample with initial highest amount of quartz (higher Si content), lowest quantity of pyrite and traces of jarosite (lower S content) developed hematite and concentrated Tl (from 10 up to 72 mg kg -1 ) after roasting at 900 °C in an oxidizing atmosphere. However, samples with lower or absent quartz content and higher pyrite amount mainly developed magnetite, accumulating Tl between 400 and 500 °C and releasing Tl from 700 up to 900 °C (from 10-29 mg kg -1 down to 4-1 mg kg -1 ). These results show the varied accumulative, or volatile, behaviors of one of the most toxic elements for life and environment, in which oxidation of Tl-bearing Fe sulfides produce Fe oxides wastes with or without Tl. The initial chemistry and mineralogy of pyrite ores should be taken into account in coal-fired power stations, cement or sulfuric acid production industry involving pyrite roasting processes, and steel, brick or paint industries, which use iron ore from roasted pyrite ash, where large amounts of Tl entail significant environmental pollution. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of Pyrite on Thiosulfate Leaching of Gold and the Role of Ammonium Alcohol Polyvinyl Phosphate (AAPP

Directory of Open Access Journals (Sweden)

Xiaoliang Liu

2017-07-01

Full Text Available The effect of pyrite and the role of ammonium alcohol polyvinyl phosphate (AAPP during gold leaching in ammoniacal thiosulfate solutions were investigated using pure gold foils. The results showed that pyrite catalyzed the decomposition and also significantly increased the consumption of thiosulfate. This detrimental effect became more severe with increasing pyrite content. Further, the presence of pyrite also substantially slowed the gold leaching kinetics and reduced the overall gold dissolution. The reduction in gold dissolution was found to be caused primarily by the surface passivation of the gold. The negative effects of pyrite, however, can be alleviated by the addition of AAPP. Comparison of zeta potentials of pyrite with and without AAPP suggests that AAPP had adsorbed on the surface of the pyrite and weakened the catalytic effect of pyrite on the thiosulfate decomposition by blocking the contact between the pyrite and thiosulfate anions. AAPP also competed with thiosulfate anions to complex with the cupric ion at the axial coordinate sites, and thus abated the oxidation of thiosulfate by cupric ions. Moreover, the indiscriminate adsorption of AAPP on the surfaces of gold and passivation species prevented the passivation of the gold surface by surface charge and electrostatic repulsion. Therefore, AAPP effectively stabilized the thiosulfate in the solution and facilitated the gold leaching in the presence of pyrite.

Influence of the Interaction between Sphalerite and Pyrite on the Copper Activation of Sphalerite

Directory of Open Access Journals (Sweden)

Bo Yang

2018-01-01

Full Text Available In this paper, the effect of pyrite on the activation of sphalerite was investigated by micro-flotation, copper adsorption experiments, X-ray photoelectron spectroscopy (XPS, and electrochemical measurement. The micro-flotation test results showed that the recovery and flotation rate of sphalerite with copper sulphate as activator and butyl xanthate as collector were significantly decreased with the increasing content of pyrite in pulp. Cu2+ adsorption results indicated that the adsorption of Cu2+ on the sphalerite surface were decreased when pyrite was present in the pulp. XPS surface analysis demonstrated that the proportion of Cu+ species increased in the activation products on the sphalerite surface, but the total atomic concentration of Cu atom was decreased. Linear voltammetry measurement suggested that the current density of Cu+ species oxidizing to Cu2+ species was increased when sphalerite was electrically contacted with pyrite, which confirmed the increased proportion of Cu+ species on Cu-activation sphalerite surface when contacting with pyrite. These results indicated that there is not only a competitive adsorption for cupric ions (Cu2+, but the galvanic interaction between sphalerite and pyrite also has a significant influence on the copper activation of sphalerite.

Isotopic and microbiological signatures of pyrite-driven denitrification in a sandy aquifer

NARCIS (Netherlands)

Zhang, Y.-C.; Slomp, C.P.; Broers, H.P.; Bostick, B.; Passier, H.F.; Böttcher, M.E.; Omoregie, E.O.; Lloyd, J.R.; Polya, D.A.; Van Cappellen, P.

2012-01-01

Denitrificationdriven by pyrite oxidation can play a major role in the removal of nitrate from groundwater systems. As yet, limited information is available on the interactions between the micro-organisms and aqueous and mineral phases in aquifers where pyrite oxidation is occurring. In this study,

A model of pyritic oxidation in waste rock dumps

International Nuclear Information System (INIS)

Davis, G.B.; Ritchie, A.I.M.

1983-01-01

The oxidation of pyrite can lead to high acid levels and high concentrations of trace metals in the water that runs off and percolates through pyritic material. This is the situation at the abandoned uranium mine at Rum Jungle in the Northern Territory of Australia, where pyritic oxidation in the waste rock dumps resulting from open cut mining of the uranium orebody has led to pollution of the nearby East Branch of the Finniss River, with trace metals such as copper, manganese and zinc. Mathematical equations are formulated which describe a model of pyritic oxidation within a waste rock dump, where it is assumed that oxygen transport is the rate limiting step in the oxidation process and that oxygen is transported by gaseous diffusion through the pore space of the dump, followed by diffusion into oxidation sites within the particles that comprise the dump. The equations have been solved numerically assuming values for such parameters as porosity, sulphur density and oxygen diffusion coefficients which are applicable to the waste rock dumps at Rum Jungle. An approximate solution to the equations is also presented. Calculations of the heat source distribution and the total SO 4 production rate are presented for both single size particles and for a range of particle sizes in the dump. The usefulness of the approximate solution, and of calculations based on single size particles in the dump in assessing the effectiveness of strategies to reduce pollution from such waste rock dumps are discussed

Relationship between pyrite Stability and arsenic mobility during aquifer storage and recovery in southwest central Florida.

Science.gov (United States)

Jones, Gregg W; Pichler, Thomas

2007-02-01

Elevated arsenic concentrations are common in water recovered from aquifer storage and recovery (ASR) systems in west-central Florida that store surface water. Investigations of the Suwannee Limestone of the Upper Floridan aquifer, the storage zone for ASR systems, have shown that arsenic is highest in pyrite in zones of high moldic porosity. Geochemical modeling was employed to examine pyrite stability in limestone during simulated injections of surface water into wells open only to the Suwannee Limestone with known mineralogy and water chemistry. The goal was to determine if aquifer redox conditions could be altered to the degree of pyrite instability. Increasing amounts of injection water were added to native storage-zone water, and resulting reaction paths were plotted on pyrite stability diagrams. Native storage-zone water plotted within the pyrite stability field, indicating that conditions were sufficiently reducing to allow for pyrite stability. Thus, arsenic is immobilized in pyrite, and its groundwater concentration should be low. This was corroborated by analysis of water samples, none of which had arsenic concentrations above 0.036 microg/L. During simulation, however, as injection/native storage-zone water ratios increased, conditions became less reducing and pyrite became unstable. The result would be release of arsenic from limestone into storage-zone water.

DFT study on the galvanic interaction between pyrite (100) and galena (100) surfaces

International Nuclear Information System (INIS)

Ke, Baolin; Li, Yuqiong; Chen, Jianhua; Zhao, Cuihua; Chen, Ye

2016-01-01

Graphical abstract: - Highlights: • Galvanic interaction is weakened with the increase of contact distance. • Electronic transfer mainly occurs on the contact layers. • Galvanic effect enhances nucleophilicity of galena and electrophilicity of pyrite. • Presence of H_2O increases the galvanic interaction. - Abstract: The galvanic interaction between pyrite and galena surface has been investigated using density functional theory (DFT) method. The calculated results show that galvanic interactions between pyrite and galena surface are decreased with the increase of contact distance. The galvanic interactions still occurs even the distance larger than the sum of two atoms radius (≈2.8 Å), and the limit distance of galvanic interaction between galena and pyrite surface is about 10 Å, which is consistent with the quantum tunneling effect. Through Mulliken charge population calculation, it is found that electrons transfer from galena to pyrite. For galena surface, Pb 6s and 6p states lose electrons and S 3p state loses a small amount of electrons, which causes the electron loss of galena. For pyrite surface, Fe 4p state obtains large numbers of electrons, resulting in the decrease of positive charge of Fe atom. However, the 3p state of S atom loses a small numbers of electrons. The reactivity of mineral surface has also been studied by calculating the frontier orbitals of minerals. Results suggest that the highest occupied molecular orbital (HOMO) coefficients of galena are increased whereas those of pyrite are decreased with the enhancing galvanic interaction, indicating that the oxidation of galena surface would be enhanced due to the galvanic interaction. The Fukui indices and dual descriptor values of surface atoms suggest that the nucleophilicity of the galena surface increases, meanwhile, the electrophilicity of pyrite surface increases with the decrease of the contact distance. In addition, the density of states (DOS) of atoms results show that the

Copper-arsenic decoupling in an active geothermal system: A link between pyrite and fluid composition

Science.gov (United States)

Tardani, Daniele; Reich, Martin; Deditius, Artur P.; Chryssoulis, Stephen; Sánchez-Alfaro, Pablo; Wrage, Jackie; Roberts, Malcolm P.

2017-05-01

Over the past few decades several studies have reported that pyrite hosts appreciable amounts of trace elements which commonly occur forming complex zoning patterns within a single mineral grain. These chemical zonations in pyrite have been recognized in a variety of hydrothermal ore deposit types (e.g., porphyry Cu-Mo-Au, epithermal Au deposits, iron oxide-copper-gold, Carlin-type and Archean lode Au deposits, among others), showing, in some cases, marked oscillatory alternation of metals and metalloids in pyrite growth zones (e.g., of Cu-rich, As-(Au, Ag)-depleted zones and As-(Au, Ag)-rich, Cu-depleted zones). This decoupled geochemical behavior of Cu and As has been interpreted as a result of chemical changes in ore-forming fluids, although direct evidence connecting fluctuations in hydrothermal fluid composition with metal partitioning into pyrite growth zones is still lacking. In this study, we report a comprehensive trace element database of pyrite from the Tolhuaca Geothermal System (TGS) in southern Chile, a young and active hydrothermal system where fewer pyrite growth rims and mineralization events are present and the reservoir fluid (i.e. ore-forming fluid) is accessible. We combined the high-spatial resolution and X-ray mapping capabilities of electron microprobe analysis (EMPA) with low detection limits and depth-profiling capacity of secondary-ion mass spectrometry (SIMS) in a suite of pyrite samples retrieved from a ∼1 km drill hole that crosses the argillic (20-450 m) and propylitic (650-1000 m) alteration zones of the geothermal system. We show that the concentrations of precious metals (e.g., Au, Ag), metalloids (e.g., As, Sb, Se, Te), and base and heavy metals (e.g., Cu, Co, Ni, Pb) in pyrite at the TGS are significant. Among the elements analyzed, As and Cu are the most abundant with concentrations that vary from sub-ppm levels to a few wt.% (i.e., up to ∼5 wt.% As, ∼1.5 wt.% Cu). Detailed wavelength-dispersive spectrometry (WDS) X

Isotopic and microbiological signatures of pyrite-driven denitrification in a sandy aquifer

NARCIS (Netherlands)

Zhang, Y.C.; Slomp, C.P.; Broers, H.P.; Bostick, B.; Passier, H.F.; Böttcher, M.E.; Omoregie, E.O.; Lloyd, J.R.; Polya, D.A.; Cappellen, P. van

2012-01-01

Denitrification driven by pyrite oxidation can play a major role in the removal of nitrate from groundwater systems. As yet, limited information is available on the interactions between the micro-organisms and aqueous and mineral phases in aquifers where pyrite oxidation is occurring. In this study,

Pyrite Passivation by Triethylenetetramine: An Electrochemical Study

Directory of Open Access Journals (Sweden)

Yun Liu

2013-01-01

Full Text Available The potential of triethylenetetramine (TETA to inhibit the oxidation of pyrite in H2SO4 solution had been investigated by using the open-circuit potential (OCP, cyclic voltammetry (CV, potentiodynamic polarization, and electrochemical impedance (EIS, respectively. Experimental results indicate that TETA is an efficient coating agent in preventing the oxidation of pyrite and that the inhibition efficiency is more pronounced with the increase of TETA. The data from potentiodynamic polarization show that the inhibition efficiency (η% increases from 42.08% to 80.98% with the concentration of TETA increasing from 1% to 5%. These results are consistent with the measurement of EIS (43.09% to 82.55%. The information obtained from potentiodynamic polarization also displays that the TETA is a kind of mixed type inhibitor.

Operating-procedure system at Savannah River Plant

International Nuclear Information System (INIS)

Tope, C.W.

1981-05-01

Three types of procedures are widely used at SRP: Du Pont Savannah Operating Logsheet, Du Pont Savannah Operating Procedure, and Plant Manual. This document briefly reviews originating of the procedures, their preparation, control, and indexing

Production of ferric sulphate from pyrite by thiobacillus ferrooxidans. Application to uranium ore leaching

International Nuclear Information System (INIS)

Rouas, C.

1988-12-01

A process for uranium extraction by oxidizing solutions of ferric sulphate produced by T. ferrooxidans from pyrite is developed. A new counting method specific of T. ferrooxidans is designed. An uranium resistant wild strain, with oxidizing properties as high as the strain ATCC 19859, is isolated. Optimal conditions for ferric sulphate production from pyrite are defined (pH 1.8, density of the medium 1.2%, pyrite granulometry [fr

Tritium in the Savannah River Estuary and adjacent marine waters

International Nuclear Information System (INIS)

Hayes, D.W.

1978-01-01

The tritium distribution in the Savannah River estuary and adjacent marine waters was measured to provide information on the dilution, mixing, and movement of Savannah River water in this region. The Savannah River marine region was chosen because the average tritium concentration in this river is 5 pCi/ml, whereas other rivers in the southeastern United States average less than 0.5 pCi/ml. The increased tritium concentration in the Savannah River is due to releases from the Savannah River Plant of the Department of Energy. Tritium measurements have proved particularly effective in estimating the flushing time of the Savannah River estuary (2.4 days) and in delineating the relative contribution to the water masses in Ossabaw and Port Royal Sounds from the River and from sea water. Ossabaw and Port Royal Sounds are located approximately 20 km south and north of the Savannah River estuary, respectively

Virtual Savannah

DEFF Research Database (Denmark)

Rodil, Kasper; Eskildsen, Søren; Rehm, Matthias

2012-01-01

Virtual Savannah is constructed to visualize parts of a curriculum, which the educational service at Aalborg Zoo has difficulties in teaching children visiting the zoo. It contains rich media like audio, text, video and picture galleries about African ecology, but some of this episodic information...

Report on assessment of the mechanism of bacterially assisted oxidation of pyritic uranium tailings

International Nuclear Information System (INIS)

Halbert, B.B.; Scharer, J.M.; Knapp, R.A.

1984-07-01

The oxidation of pyritic minerals has been shown to be catalyzed by the presence of iron- and sulphur-oxidizing bacteria. Thiobacillus ferroxidans plays the most significant role in the formation and propagation of acidic conditions. Optimum growth conditions for the T. ferroxidans occurs at a temperature of 35 degrees C and pH of 2 to 3. Bacterially assisted oxidation of pyrite involves both direct and indirect contact mechanisms. The direct contact mechanism entails enzymatic oxidation of the insoluble sulphide moiety. The indirect mechanism involves bacterial oxidation of the dissolved ferrous component to the ferric state. The ferric iron, in turn, acts as the prime oxidant of pyrite and is reduced to ferrous iron. The re-oxidation of the dissolved ferrous component which is catalyzed by bacterial activity, completes the cyclic process. The rate of bacterial oxidation is affected by: the geochemistry and reactivity of the pyritic material; the amount of pyrite present in the waste material and the exposed surface area of the pyritic component; the availability of oxygen and carbon dioxide; the pH and temperature of the leach solution; and the presence (or absence) of organic inhibitors. Of the above factors, oxygen has been frequently identified as the rate limiting reactant in tailings

Heterocoagulation of chalcopyrite and pyrite minerals in flotation separation.

Science.gov (United States)

Mitchell, Timothy K; Nguyen, Anh V; Evans, Geoffrey M

2005-06-30

Heterocoagulation between various fine mineral particles contained within a mineral suspension with different structural and surface chemistry can interfere with the ability of the flotation processes to selectively separate the minerals involved. This paper examines the interactions between chalcopyrite (a copper mineral) and pyrite (an iron mineral often bearing gold) as they approach each other in suspensions with added chemicals, and relates the results to the experimental data for the flotation recovery and selectivity. The heterocoagulation was experimentally studied using the electrophoretic light scattering (ELS) technique and was modelled by incorporating colloidal forces, including the van der Waals, electrostatic double layer and hydrophobic forces. The ELS results indicated that pyrite has a positive zeta potential (zeta) up to its isoelectric point (IEP) at approximately pH 2.2, while chalcopyrite has a positive zeta up to its IEP at approximately pH 5.5. This produces heterocoagulation of chalcopyrite with pyrite between pH 2.2 and pH 5.5. The heterocoagulation was confirmed by the ELS spectra measured with a ZetaPlus instrument from Brookhaven and by small-scale flotation experiments.

Geochemistry of shale and sedimentary pyrite as a proxy for gold fertility in the Selwyn basin area, Yukon

Science.gov (United States)

Sack, Patrick J.; Large, Ross R.; Gregory, Daniel D.

2018-01-01

Selwyn basin area strata contain sedimentary pyrite with Au above background levels when analyzed by laser ablation-inductively coupled mass spectrometry. Hyland Group rocks contain framboidal pyrite contents of 670 ppb Au, 1223 ppm As, and 5.3 ppm Te; the mean of all types of sedimentary pyrite in the Hyland Group is 391 ppb Au, 1489 ppm As, and 3.8 ppm Te. These levels are similar to sedimentary pyrite in host lithologies from major orogenic gold districts in New Zealand and Australia. Comparison of whole rock and pyrite data show that rocks deposited in continental slope settings with significant terrigenous input contain pyrite that is consistently enriched in Au, As, Te, Co, and Cu. Although data are limited, whole rock samples of stratigraphic units containing Au-rich pyrite also contain high Au, indicating that most of the Au is within sedimentary pyrite. Based on geologic characteristics and comparison of pyrite chemistry data with whole rock chemistry, Selwyn basin area strata have the necessary ingredients to form orogenic gold deposits: Au-enriched source rocks, metamorphic conditions permissive of forming a metamorphic ore fluid, and abundant structural preparation for channeling fluids and depositing ore.

Tritium in the Savannah River estuary and adjacent marine waters

International Nuclear Information System (INIS)

Hayes, D.W.

1979-01-01

The tritium distribution in the Savannah River estuary and adjacent marine waters was measured to provide information on the dilution, mixing and movement of Savannah River water in this region. The Savannah River marine region was chosen because the average tritium concentration in this river is approximately 5 pCi/ml, whereas other rivers in the southeastern United States of America average less than 0.5 pCi/ml. The increased tritium concentration in the Savannah River is due to releases from the Savannah River Plant of the Department of Energy. Tritium measurements have proved particularly effective in estimating the flushing time of the Savannah River estuary (2.4 days) and in delineating the relative contribution to the water masses in Ossabaw and Port Royal Sounds from the river and from sea-water. Ossabaw and Port Royal Sounds are located approximately 20 km south and north of the Savannah River estuary respectively. (author)

Savannah River Site Environmental Report for 1998

Energy Technology Data Exchange (ETDEWEB)

Arnett, M

1999-06-09

The mission at the Savannah River Site (SRS) is focused primarily on support of the national defense, nonproliferation, and environmental cleanup. SRS-through its prime operating contractor, Westinghouse Savannah River Company-continues to maintain a comprehensive environmental monitoring program.

Savannah River Site Environmental Report for 1998

International Nuclear Information System (INIS)

Arnett, M.

1999-01-01

The mission at the Savannah River Site (SRS) is focused primarily on support of the national defense, nonproliferation, and environmental cleanup. SRS-through its prime operating contractor, Westinghouse Savannah River Company-continues to maintain a comprehensive environmental monitoring program

On the genesis of pyrite-polymetallic deposits of the Rudnyi Altai

International Nuclear Information System (INIS)

Puchkov, E.V.; Najdenov, B.M.

1986-01-01

Results of lead isotope composition measurements in pyrite-polymetallic deposits of the Rudnyi Altai are presented. Porphyr dating by zirconium has shown isochronous age of 552 million years. Lead of galenites of various generations and galenite form of lead of pyrit provide similar lead-isotope values with model age of 370 million years. The isotopic-geochemical data obtained are interpreted as applied to the deposit genesis

The influence of pyrite on the solubility of minjingu and panda ...

African Journals Online (AJOL)

A laboratory study was conducted to investigate the effect of pyrite rock on the solubility of Minjingu and Panda phosphate rocks. The rocks were ground to 100 mesh (0.045 mm) after which each phosphate rock was mixed with pyrite at P:S ratios of 1:4, 1 :3, 1:2, 1:1, 2:1, and 3: 1. The mixtures were moistened and incubated ...

Evaluation of pyrite and pyrrhotite in concretes

Directory of Open Access Journals (Sweden)

A. P. Marcelino

Full Text Available ABSTRACT It is well known that aggregate characteristics can intensively interfere in concrete behavior especially when sulfides are presented in the aggregates. The lack of consensus to content limit value of these deleterious sulfur compounds in concrete structures for dams has motivated several investigations worldwide. Within this scenario, this work presents a methodology to evaluate the presence of pyrite and pyrrhotite in concretes produced with aggregates containing sulfides. For the study, rock samples from the Irapé hydroelectric power plant area in Minas Gerais (Brazil were used. This plant was built in a geological site where the rock presented sulfide levels of at least 3%. These rock samples were first ground and then used as aggregates in mortars, which were, during almost one year, subjected to three different exposed conditions: temperature of 23° ± 2°C and relative humidity of 95 to 100%; calcium hydroxide solution diluted in water kept at two different temperatures: room temperature and 50° C. The presence and amount of pyrrhotite were obtained from a leaching process of the material (aggregate or mortar in a solution of hydrochloric acid. This procedure allowed also the evaluation of the pyrite content. The results showed that the amount of pyrite has remained virtually constant over time in the three exposure situations. This finding indicates that sulfur limits in aggregates should be set according to the type of iron sulfide presented and not solely by the total amount of sulfur.

Stable silicon isotope signatures of marine pore waters - Biogenic opal dissolution versus authigenic clay mineral formation

Science.gov (United States)

Ehlert, Claudia; Doering, Kristin; Wallmann, Klaus; Scholz, Florian; Sommer, Stefan; Grasse, Patricia; Geilert, Sonja; Frank, Martin

2016-10-01

Dissolved silicon isotope compositions have been analysed for the first time in pore waters (δ30SiPW) of three short sediment cores from the Peruvian margin upwelling region with distinctly different biogenic opal content in order to investigate silicon isotope fractionation behaviour during early diagenetic turnover of biogenic opal in marine sediments. The δ30SiPW varies between +1.1‰ and +1.9‰ with the highest values occurring in the uppermost part close to the sediment-water interface. These values are of the same order or higher than the δ30Si of the biogenic opal extracted from the same sediments (+0.3‰ to +1.2‰) and of the overlying bottom waters (+1.1‰ to +1.5‰). Together with dissolved silicic acid concentrations well below biogenic opal saturation, our collective observations are consistent with the formation of authigenic alumino-silicates from the dissolving biogenic opal. Using a numerical transport-reaction model we find that approximately 24% of the dissolving biogenic opal is re-precipitated in the sediments in the form of these authigenic phases at a relatively low precipitation rate of 56 μmol Si cm-2 yr-1. The fractionation factor between the precipitates and the pore waters is estimated at -2.0‰. Dissolved and solid cation concentrations further indicate that off Peru, where biogenic opal concentrations in the sediments are high, the availability of reactive terrigenous material is the limiting factor for the formation of authigenic alumino-silicate phases.

Selective separation of arsenopyrite from pyrite by biomodulation in the presence of Acidithiobacillus ferrooxidans.

Science.gov (United States)

Chandraprabha, M N; Natarajan, K A; Somasundaran, P

2004-08-15

Effective methods for selective separation using flotation or flocculation of arsenopyrite from pyrite by biomodulation using Acidithiobacillus ferrooxidans are presented here. Adhesion of the bacterium to the surface of arsenopyrite was very slow compared to that to pyrite, resulting in a difference in surface modification of the minerals subsequent to interaction with cells. The cells were able to effectively depress pyrite flotation in presence of collectors like potassium isopropyl xanthate and potassium amyl xanthate. On the other hand the flotability of arsenopyrite after conditioning with the cells was not significantly affected. The activation of pyrite by copper sulfate was reduced when the minerals were conditioned together, resulting in better selectivity. Selective separation could also be achieved by flocculation of biomodulated samples.

Attenuation of pyrite oxidation with a fly ash pre-barrier: Reactive transport modelling of column experiments

Energy Technology Data Exchange (ETDEWEB)

Perez-Lopez, R.; Cama, J.; Nieto, J.M.; Ayora, C.; Saaltink, M.W. [University of Huelva, Huelva (Spain). Dept. of Geology

2009-09-15

Conventional permeable reactive barriers (PRBs) for passive treatment of groundwater contaminated by acid mine drainage (AMD) use limestone as reactive material that neutralizes water acidity. However, the limestone-alkalinity potential ceases as inevitable precipitation of secondary metal-phases on grain surfaces occurs, limiting its efficiency. In the present study, fly ash derived from coal combustion is investigated as an alternative alkalinity generating material for the passive treatment of AMD using solution-saturated column experiments. Unlike conventional systems, the utilization of fly ash in a pre-barrier to intercept the non-polluted recharge water before this water reacts with pyrite-rich wastes is proposed. Chemical variation in the columns was interpreted with the reactive transport code RETRASO. In parallel, kinetics of fly ash dissolution at alkaline pH were studied using flow-through experiments and incorporated into the model. In a saturated column filled solely with pyritic sludge-quartz sand (1: 10), oxidation took place at acidic conditions (pH 3.7). According to SO{sub 4}{sup 2-} release and pH, pyrite dissolution occurred favourably in the solution-saturated porous medium until dissolved O{sub 2} was totally consumed. In a second saturated column, pyrite oxidation took place at alkaline conditions (pH 10.45) as acidity was neutralized by fly ash dissolution in a previous level. At this pH Fe release from pyrite dissolution was immediately depleted as Fe-oxy(hydroxide) phases that precipitated on the pyrite grains, forming Fe-coatings (microencapsulation). With time, pyrite microencapsulation inhibited oxidation in practically 97% of the pyritic sludge. Rapid pyrite-surface passivation decreased its reactivity, preventing AMD production in the relatively short term.

Sulfur amino acids and alanine on pyrite (100) by X-ray photoemission spectroscopy: Surface or molecular role?

Energy Technology Data Exchange (ETDEWEB)

Sanchez-Arenillas, M.; Galvez-Martinez, S.; Mateo-Marti, E., E-mail: mateome@cab.inta-csic.es

2017-08-31

Highlights: • Surface annealing pretreatment on pyrite surfaces can select molecular adsorption. • Enriched monosulfide species on pyrite (100) surface favors NH{sub 2} adsorption form. • Enriching disulfide species on pyrite (100) surface promotes NH{sub 3}{sup +} adsorption form. • Unique structure of each aminoacid provides a particular fingerprint in the process. • Spectroscopy evidence, pretreatment surface processes drives molecular adsorption. - Abstract: This paper describes the first successful adsorption of the cysteine, cystine, methionine and alanine amino acids on the pyrite (100) surface under ultra-high vacuum conditions with crucial chemical adsorption parameters driving the process. We have demonstrated by X-ray photoemission spectroscopy (XPS) that the surface pretreatment annealing process on pyrite surfaces is a critical parameter driving surface reactivity. The presence of enriched monosulfide species on the pyrite (100) surface favours the amino acid NH{sub 2} chemical form, whereas a longer annealing surface pretreatment of over 3 h repairs the sulfur vacancies in the pyrite, enriching disulfide species on the pyrite surface, which promotes NH{sub 3}{sup +} adsorption due to the sulfur vacancies in the pyrite being replaced by sulfur atom dimers (S{sub 2}{sup 2−}) on the surface. Furthermore, even if the surface chemistry (monosulfide or disulfide species enrichment) is the main factor promoting a partial conversion from NH{sub 2} to NH{sub 3}{sup +} species, the unique chemical structure of each amino acid provides a particular fingerprint in the process.

Pyrite-enhanced methylene blue degradation in non-thermal plasma water treatment reactor

Energy Technology Data Exchange (ETDEWEB)

Benetoli, Luis Otavio de Brito, E-mail: luskywalcker@yahoo.com.br [Departamento de Quimica, Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil); Cadorin, Bruno Mena; Baldissarelli, Vanessa Zanon [Departamento de Quimica, Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil); Geremias, Reginaldo [Departamento de Ciencias Rurais, Universidade Federal de Santa Catarina (UFSC), Curitibanos, SC (Brazil); Goncalvez de Souza, Ivan [Departamento de Quimica, Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil); Debacher, Nito Angelo, E-mail: debacher@qmc.ufsc.br [Departamento de Quimica, Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil)

2012-10-30

Highlights: Black-Right-Pointing-Pointer We use O{sub 2} as the feed gas and pyrite was added to the non-thermal plasma reactor. Black-Right-Pointing-Pointer The methylene blue removal by NTP increased in the presence of pyrite. Black-Right-Pointing-Pointer The total organic carbon content decreased substantially. Black-Right-Pointing-Pointer The acute toxicity test showed that the treated solution is not toxic. Black-Right-Pointing-Pointer The dye degradation occurs via electron impact as well as successive hydroxylation. - Abstract: In this study, methylene blue (MB) removal from an aqueous phase by electrical discharge non-thermal plasma (NTP) over water was investigated using three different feed gases: N{sub 2}, Ar, and O{sub 2}. The results showed that the dye removal rate was not strongly dependent on the feed gas when the electrical current was kept the same for all gases. The hydrogen peroxide generation in the water varied according to the feed gas (N{sub 2} < Ar < O{sub 2}). Using O{sub 2} as the feed gas, pyrite was added to the reactor in acid medium resulting in an accentuated increase in the dye removal, which suggests that pyrite acts as a Fenton-like catalyst. The total organic carbon (TOC) content of the dye solution decreased slightly as the plasma treatment time increased, but in the presence of the pyrite catalyst the TOC removal increased substantially. The acute toxicity test using Artemia sp. microcrustaceans showed that the treated solution is not toxic when Ar, O{sub 2} or O{sub 2}-pyrite is employed. Electrospray ionization mass spectrometry analysis (ESI-MS) of the treated samples indicated that the dye degradation occurs via high energy electron impact as well as successive hydroxylation in the benzene rings of the dye molecules.

Pyrite-pyrrhotite intergrowths in calcite marble from Bistriški Vintgar, Slovenia

International Nuclear Information System (INIS)

Zavašnik, J

2016-01-01

Roman marble quarry in Bistrica gorge in southern Pohorje Mt. (north-eastern Slovenia) is situated in a 20 m thick lens of layered marble, at the contact zone between granodiorite and metamorphites. Grey and yellowish non-homogenous calcite marble is heavily included by mica, quartz, feldspars, zoisite, pyrite and amphiboles. In the present research, we have studied numerous pyrite (FeS 2 ) crystals associated with yellowish-bronze non-stoichiometric pyrrhotite (Fe 1−x S), not previously reported from this locality. SEM investigation revealed unusual sequence of crystallisation: primary skeletal pyrrhotite matrix is sparsely overgrown by well-crystalline pyrite, both being overgrown by smaller, well-developed hexagonal pyrrhotite crystals of the second generation. With TEM we identify the pyrrhotite as 5T-Fe 1-x S phase, where x is about 0.1 and is equivalent to Fe 9 S 10 . The pyrite-pyrrhotite coexistence allows us a construction of fO 2 -pH diagram of stability fields, which reflects geochemical conditions at the time of marble re-crystallisation. (paper)

Pyritized ooids from the Arabian Sea basin

Digital Repository Service at National Institute of Oceanography (India)

Rao, P.S.; Rao, Ch.M.; Reddy, N.P.C.

Pyritized ooids in association with turbidites were observed in a box core collected at a depth of 3627 m from the Arabian Sea Basin. Ooids having a shallow water origin were transported to the present depth by turbidity currents or slumping...

Insights into methane dynamics from analysis of authigenic carbonates and chemosynthetic mussels at newly-discovered Atlantic Margin seeps

Science.gov (United States)

Prouty, Nancy G.; Sahy, Diana; Ruppel, Carolyn D.; Roark, E. Brendan; Condon, Dan; Brooke, Sandra; Ross, Steve W.; Demopoulos, Amanda W.J.

2016-01-01

The recent discovery of active methane venting along the US northern and mid-Atlantic margin represents a new source of global methane not previously accounted for in carbon budgets from this region. However, uncertainty remains as to the origin and history of methane seepage along this tectonically inactive passive margin. Here we present the first isotopic analyses of authigenic carbonates and methanotrophic deep-sea mussels, Bathymodiolus   sp., and the first direct constraints on the timing of past methane emission, based on samples collected at the upper slope Baltimore Canyon (∼385 m water depth) and deepwater Norfolk (∼1600 m) seep fields within the area of newly-discovered venting. The authigenic carbonates at both sites were dominated by aragonite, with an average  signature of −47‰, a value consistent with microbially driven anaerobic oxidation of methane-rich fluids occurring at or near the sediment–water interface. Authigenic carbonate U and Sr isotope data further support the inference of carbonate precipitation from seawater-derived fluids rather than from formation fluids from deep aquifers. Carbonate stable and radiocarbon ( and ) isotope values from living Bathymodiolus   sp. specimens are lighter than those of seawater dissolved inorganic carbon, highlighting the influence of fossil carbon from methane on carbonate precipitation. U–Th dates on authigenic carbonates suggest seepage at Baltimore Canyon between 14.7±0.6 ka to 15.7±1.6 ka, and at the Norfolk seep field between 1.0±0.7 ka to 3.3±1.3 ka, providing constraint on the longevity of methane efflux at these sites. The age of the brecciated authigenic carbonates and the occurrence of pockmarks at the Baltimore Canyon upper slope could suggest a link between sediment delivery during Pleistocene sea-level lowstand, accumulation of pore fluid overpressure from sediment compaction, and release of overpressure through subsequent venting. Calculations show that

In situ characterization of natural pyrite bioleaching using electrochemical noise technique

Science.gov (United States)

Chen, Guo-bao; Yang, Hong-ying; Li, Hai-jun

2016-02-01

An in situ characterization technique called electrochemical noise (ECN) was used to investigate the bioleaching of natural pyrite. ECN experiments were conducted in four active systems (sulfuric acid, ferric-ion, 9k culture medium, and bioleaching solutions). The ECN data were analyzed in both the time and frequency domains. Spectral noise impedance spectra obtained from power spectral density (PSD) plots for different systems were compared. A reaction mechanism was also proposed on the basis of the experimental data analysis. The bioleaching system exhibits the lowest noise resistance of 0.101 MΩ. The bioleaching of natural pyrite is considered to be a bio-battery reaction, which distinguishes it from chemical oxidation reactions in ferric-ion and culture-medium (9k) solutions. The corrosion of pyrite becomes more severe over time after the long-term testing of bioleaching.

Transuranic waste management at Savannah River - past, present, and future

International Nuclear Information System (INIS)

D'Ambrosia, J.

1985-01-01

The major objective of the TRU program at Savannah River is to support the TRU National Program, which is dedicated to preparing waste for, and emplacing waste in, the Waste Isolation Pilot Plant, (WIPP). Thus, the Savannah River Program also supports WIPP operations. The Savannah River site specific goals to phase out the indefinite storage of TRU waste, which has been the mode of waste management since 1974, and to dispose of Savannah River's Defense TRU waste

Use of the Moessbauer effect for determining pyritic sulfur content in coal

Energy Technology Data Exchange (ETDEWEB)

Czerw, B; Sikora, T

1986-10-01

This paper discusses investigations into resonance absorption of gamma radiation. Standard equipment for measuring the Moessbauer effect in black coal consisting of a measuring head, the SM-4T spectrometer, a multichannel analyzer, the Standard electronic unit and a printer is evaluated. The MSP measuring system developed jointly by the EMAG Mine Automation Company and the Nuclear Research Institute in Swierk is described. The MSP equipment is used for measuring content of pyritic sulfur in coal. Its accuracy is satisfactory. Results of measuring pyritic and total sulfur content by means of quantitative chemical analysis and by the MSP resonance absorption method (Moessbauer effect) are compared. The mean standard deviation for pyritic sulfur is 0.14% and for total sulfur content 0.21%. 11 refs.

Microbial Oxidation of Pyrite Coupled to Nitrate Reduction in Anoxic Groundwater Sediment

DEFF Research Database (Denmark)

Jørgensen, Christian Juncher; Elberling, Bo; Jacobsen, Ole Stig

2009-01-01

denitrification process with pyrite as the primary electron donor. The process demonstrates a temperature dependency (Q10) of 1.8 and could be completely inhibited by addition of a bactericide (NaN3). Experimentally determined denitrification rates show that more than 50% of the observed nitrate reduction can...... be ascribed to pyrite oxidation. The apparent zero-order denitrification rate in anoxic pyrite containing sediment at groundwater temperature has been determined to be 2-3 µmol NO3- kg-1 day-1. The in situ groundwater chemistry at the boundary between the redoxcline and the anoxic zone reveals that between 65......-anoxic boundary in sandy aquifers thus determining the position and downward progression of the redox boundary between nitrate-containing and nitrate-free groundwater....

Sulfur amino acids and alanine on pyrite (100) by X-ray photoemission spectroscopy: Surface or molecular role?

Science.gov (United States)

Sanchez-Arenillas, M.; Galvez-Martinez, S.; Mateo-Marti, E.

2017-08-01

This paper describes the first successful adsorption of the cysteine, cystine, methionine and alanine amino acids on the pyrite (100) surface under ultra-high vacuum conditions with crucial chemical adsorption parameters driving the process. We have demonstrated by X-ray photoemission spectroscopy (XPS) that the surface pretreatment annealing process on pyrite surfaces is a critical parameter driving surface reactivity. The presence of enriched monosulfide species on the pyrite (100) surface favours the amino acid NH2 chemical form, whereas a longer annealing surface pretreatment of over 3 h repairs the sulfur vacancies in the pyrite, enriching disulfide species on the pyrite surface, which promotes NH3+ adsorption due to the sulfur vacancies in the pyrite being replaced by sulfur atom dimers (S22-) on the surface. Furthermore, even if the surface chemistry (monosulfide or disulfide species enrichment) is the main factor promoting a partial conversion from NH2 to NH3+ species, the unique chemical structure of each amino acid provides a particular fingerprint in the process.

Spatial Mapping for Managing Oxidized Pyrite (FeS2 in South Sumatra Wetlands, Indonesia

Directory of Open Access Journals (Sweden)

M. Edi Armanto

2016-02-01

Full Text Available The research aimed to analyze spatial mapping for managing oxidized pyrite (FeS2 in South Sumatra wetlands, Indonesia. The field observations are done by exploring several transect on land units. The field description refers to Soil Survey Staff (2014. Water and soil samples were taken from selected key areas for laboratory analysis. The vegetation data was collected by making sample plots (squares method placed on each vegetation type with plot sizes depending on the vegetation type, namely 10 x 10 m for secondary forests and 5 x 5 m for shrubs and grass. The observations of surface water level were done during the river receding with units of m above sea level (m asl. The research results showed that pyrite formation is largely determined by the availability of natural vegetation as Sulfur (S donors, climate and uncontrolled water balance and supporting fauna such as crabs and mud shrimp.  Climate and water balance as well as supporting faunas is the main supporting factors to accelerate the process of pyrite formation. Oxidized pyrite serves to increase soil acidity, becomes toxic to fish ponds and arable soils, plant growth and disturbing the water and soil nutrient balances. Oxidized pyrite is predominantly accelerated by the dynamics of river water and disturbed natural vegetation by human activities.  The pyrite oxidation management approach is divided into three main components of technologies, namely water management, land management and commodity management.

Remote sensing of wetlands at the Savannah River Plant

International Nuclear Information System (INIS)

Christensen, E.J.; Jensen, J.R.; Sharitz, R.R.

1985-01-01

The Savannah River Plant (SRP) occupies about 300 sq mi along a 10-mile stretch of the Savannah River. Large areas of wetlands cover the site, especially along tributary stream floodplains and the Savannah River. Some of these areas have been altered by cooling water discharges from nuclear production reactors onsite. To assess the effects of current and future plant operations on SRP and regional wetlands, an accurate quantitative survey was needed. Several studies were initiated to provide wetland acreage and distribution information: regional wetland inventories were provided from an analysis of LANDSAT multispectral scanner (MSS) satellite data. Wetlands were mapped throughout the entire Savannah River watershed and in the Savannah River floodplain. SRP wetlands were identified using a combination of LANDSAT MSS and Thematic Mapper satellite data and aerial photography. Wetlands in the SRP Savannah River swamp and thermally affected areas were mapped using high resolution MSS data collected from a low-flying aircraft. Vegetation communities in areas receiving cooling water discharges were then compared to surface temperatures measured from the airborne scanner at the same time to evaluate plant temperature tolerance. Historic changes to SRP wetlands from cooling water discharges were tabulated using aerial photography

Pyrite: A blender plugin for visualizing molecular dynamics simulations using industry-standard rendering techniques.

Science.gov (United States)

Rajendiran, Nivedita; Durrant, Jacob D

2018-05-05

Molecular dynamics (MD) simulations provide critical insights into many biological mechanisms. Programs such as VMD, Chimera, and PyMOL can produce impressive simulation visualizations, but they lack many advanced rendering algorithms common in the film and video-game industries. In contrast, the modeling program Blender includes such algorithms but cannot import MD-simulation data. MD trajectories often require many gigabytes of memory/disk space, complicating Blender import. We present Pyrite, a Blender plugin that overcomes these limitations. Pyrite allows researchers to visualize MD simulations within Blender, with full access to Blender's cutting-edge rendering techniques. We expect Pyrite-generated images to appeal to students and non-specialists alike. A copy of the plugin is available at http://durrantlab.com/pyrite/, released under the terms of the GNU General Public License Version 3. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Adsorção de xantatos sobre pirita Adsorption of xanthate on pyrite

Directory of Open Access Journals (Sweden)

Fábio Garcia Penha

2001-10-01

Full Text Available This paper presents a study of adsorption of xanthate with alkyl chain of two (C2XK, four (C4XK and eight (C8XK atoms of carbon, on pyrite from Santa Catarina, Brazil. The results showed that pyrite surface changes from hydrophilic to hydrophobic when xanthate is adsorbed increasing the contact angle to 35º for C2XK, and to 90º for C4XK and C8XK. The rate of flotation of pyrite particles after adsorption increases with the increase of the number of carbon atoms in the alkyl chain in agreement with the results of contact angle measurements.

Biogeochemical processes controlling authigenic carbonate formation within the sediment column from the Okinawa Trough

Science.gov (United States)

Li, Jiwei; Peng, Xiaotong; Bai, Shijie; Chen, Zhiyan; Van Nostrand, Joy D.

2018-02-01

Authigenic carbonates are one type of conspicuous manifestation in seep environments that can provide long-term archives of past seepage activity and methane cycling in the oceans. Comprehensive investigations of the microbial community functional structure and their roles in the process of carbonate formation are, however, lacking. In this study, the mineralogical, geochemical, and microbial functional composition were examined in seep carbonate deposits collected from the west slope of the northern section of the Okinawa Trough (OT). The aim of this work was to explore the correspondence between the mineralogical phases and microbial metabolism during carbonate deposit formation. The mineralogical analyses indicated that authigenic carbonate minerals (aragonite, magnesium-rich calcite, dolomite, ankerite and siderite) and iron-bearing minerals (limonite, chlorite, and biotite) were present in these carbonate samples. The carbon and oxygen isotopic values of the carbonate samples varied between -51.1‰ to -4.7‰ and -4.8‰ to 3.7‰, respectively. A negative linear correlation between carbon and oxygen isotopic compositions was found, indicating a mixture of methane-derived diagenetic (low δ13C/high 18O) carbonates and detrital origin (high δ13C/low 18O) carbonates at the OT. GeoChip analyses suggested that various metabolic activities of microorganisms, including methanogenesis, methane oxidation, sulfite oxidation, sulfate reduction, and metal biotransformations, all occurred during the formation process. On the basis of these findings, the following model for the methane cycle and seep carbonate deposit formation in the sediment column at the OT is proposed: (1) in the upper oxidizing zone, aerobic methane oxidation was the main way of methane consumption; (2) in the sulfate methane transition zone, sulfate-dependent AOM (anaerobic oxidation of methane) consumes methane, and authigenic minerals such as aragonite, magnesium-calcite, and sulfide minerals

Preparation of natural pyrite nanoparticles by high energy planetary ball milling as a nanocatalyst for heterogeneous Fenton process

Energy Technology Data Exchange (ETDEWEB)

Fathinia, Siavash [Department of Mining Engineering, Faculty of Engineering and Technology, Imam Khomeini International University, Qazvin (Iran, Islamic Republic of); Research Laboratory of Advanced Water and Wastewater Treatment Processes, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of); Fathinia, Mehrangiz [Research Laboratory of Advanced Water and Wastewater Treatment Processes, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of); Rahmani, Ali Akbar [Department of Mining Engineering, Faculty of Engineering and Technology, Imam Khomeini International University, Qazvin (Iran, Islamic Republic of); Khataee, Alireza, E-mail: a_khataee@tabrizu.ac.ir [Research Laboratory of Advanced Water and Wastewater Treatment Processes, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of)

2015-02-01

Graphical abstract: - Highlights: • Pyrite nanoparticles were successfully produced by planetary ball milling process. • The physical and chemical properties of pyrite nanoparticles were fully examined. • The degradation of AO7 was notably enhanced by pyrite nanoparticles Fenton system. • The influences of basic operational parameters were investigated using CCD. - Abstract: In the present study pyrite nanoparticles were prepared by high energy mechanical ball milling utilizing a planetary ball mill. Various pyrite samples were produced by changing the milling time from 2 h to 6 h, in the constant milling speed of 320 rpm. X-ray diffraction (XRD), scanning electron microscopy (SEM) linked with energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FT-IR) analysis and Brunauer–Emmett–Teller (BET) were performed to explain the characteristics of primary (unmilled) and milled pyrite samples. The average particle size distribution of the produced pyrite during 6 h milling was found to be between 20 nm and 100 nm. The catalytic performance of the different pyrite samples was examined in the heterogeneous Fenton process for degradation of C.I. Acid Orange 7 (AO7) solution. Results showed that the decolorization efficiency of AO7 in the presence of 6 h-milled pyrite sample was the highest. The impact of key parameters on the degradation efficiency of AO7 by pyrite nanoparticles catalyzed Fenton process was modeled using central composite design (CCD). Accordingly, the maximum removal efficiency of 96.30% was achieved at initial AO7 concentration of 16 mg/L, H{sub 2}O{sub 2} concentration of 5 mmol/L, catalyst amount of 0.5 g/L and reaction time of 25 min.

Thallium-rich pyrite ores from the Apuan Alps, Tuscany, Italy:constraints for their origin and environmental concerns

Science.gov (United States)

D'Orazio, Massimo; Biagioni, Cristian; Dini, Andrea; Vezzoni, Simone

2017-06-01

The southern sector of the Apuan Alps (AA) massif, Tuscany, Italy, is characterized by the occurrence of a series of baryte-pyrite-iron oxide orebodies whose Tl-rich nature was recognized only recently. The geochemistry of the pyrite ore was investigated through inductively coupled plasma mass spectrometry. In addition, lead isotope data for selected pyrite ores from AA were collected. Pyrite ores are characterized by a complex geochemistry, with high concentrations of Tl (up to 1100 μg/g) coupled with high As and Sb contents; the Co/Ni ratio is always <1. Geochemical data of pyrite and marcasite ore samples from other mining districts of Tuscany have been collected in order to compare them with those from the AA. These samples usually have very low Tl content (less than 2 μg/g) and high to very high Co/Ni and As/Sb ratios. Only some samples from the Sb-Hg ore deposits showed very high Tl concentrations (up to 3900 μg/g). Another difference is related to the lead isotope composition, with pyrite ores from AA markedly less radiogenic than those from the other deposits from Tuscany. Geochemical data of pyrite ores from AA give new insights on the genesis of the baryte-pyrite-iron oxide orebodies, relating their formation to low-temperature hydrothermal systems active during early Paleozoic; in addition, these data play a fundamental role in assessing the environmental impact of these deposits.

A dynamic mathematical model for microbial removal of pyritic sulfur from coal.

Science.gov (United States)

Kargi, F; Weissman, J G

1984-06-01

A dynamic mathematical model has been developed to describe microbial desulfurization of coal by Thiobacillus ferrooxidans. The model considers adsorption and desorption of cells on coal particles and microbial oxidation of pyritic sulfur on particle surfaces. The influence of certain parameters, such as microbial growth rate constants, adsorption-description constants, pulp density, coal particle size, initial cell and solid phase substrate concentration on the maximum rate of pyritic sulfur removal, have been elucidated. The maximum rate of pyritic sulfur removal was strongly dependent upon the number of attached cells per coal particle. At sufficiently high initial cell concentrations, the surfaces of coal particles are nearly saturated by the cells and the maximum leaching rate is limited either by total external surface area of coal particles or by the concentration of pyritic sulfur in the coal phase. The maximum volumetric rate of pyritic sulfur removal (mg S/h cm(3) mixture) increases with the pulp density of coal and reaches a saturation level at high pulp densities (e.g. 45%). The maximum rate also increases with decreasing particle diameter in a hyperbolic form. Increases in adsorption coefficient or decreases in the desorption coefficient also result in considerable improvements in this rate. The model can be applied to other systems consisting of suspended solid substrate particles in liquid medium with microbial oxidation occurring on the particle surfaces (e.g., bacterial ore leaching). The results obtained from this model are in good agreement with published experimental data on microbial desulfurization of coal and bacterial ore leaching.

Assessing the impact of preload on pyrite-rich sediment and groundwater quality.

Science.gov (United States)

Karikari-Yeboah, Ohene; Addai-Mensah, Jonas

2017-02-01

Pyrite-rich sediments would, invariably, undergo redox reactions which would lead to acidic aqueous environment containing solubilized toxic metal species. When such sediments are subjected to preload, a technique employed by geotechnical engineers to improve the load-bearing capacity of highly compressible formation, transient flow of pore water, accompanied by acidity transfer, would occur as a response. Despite the concomitant environmental and socio-economic significance, to date, there has been limited interdisciplinary research on the underpinning geotechnical engineering and geo-environmental science issues for pyrite-rich sediments under preload. In this study, we investigate the effect of pyrite-rich sediment pore water transfer under preload surcharge on the receiving environment and the impact on the groundwater speciation and quality. Sediment samples were obtained at close depth intervals from boreholes established within pristine areas and those subjected to the preload application. Soil and pore water samples were subjected to solid/solution speciation, moisture contents, soil pH and the Atterberg Limits' analyses using standard analytical techniques and methods. Standpipes were also installed in the boreholes for groundwater sampling and in situ monitoring of water quality parameters. It is shown that the imposition of preload surcharge over pyritic sediment created a reducing environment rich in SO 4 2- , iron oxide minerals and organic matter. This reducing environment fostered organic carbon catabolism to generate excess pyrite and bicarbonate alkalinity, which would invariably impact adversely on soil quality and plant growth. These were accompanied by increase in pH, dissolved Al, Ca, Mg and K species beneath the surcharge.

Composition and origin of authigenic carbonates in the Krishna-Godavari and Mahanadi Basins, eastern continental margin of India

Digital Repository Service at National Institute of Oceanography (India)

Teichert, B.M.A.; Johnson, J.E.; Solomon, E.A.; Giosan, L.; Rose, K.; Kocherla, M.; Connolly, E.C.; Torres, M.E.

of India in the Bay of Bengal. Authigenic carbonate cements,(micro) nodules, bioturbation casts and tubes from 12 core locations drilled during the Indian National Gas Hydrate Program (NGHP) Expedition 01 were investigated for this study. Three main...

Isotopic and elemental chemistry of sedimentary pyrite: A combined analytical and statistical approach to a novel planetary biosignature

Science.gov (United States)

Figueroa, M. C.; Gregory, D. D.; Lyons, T. W.; Williford, K. H.

2017-12-01

Life processes affect trace element abundances in pyrite such that sedimentary and hydrothermal pyrite have significantly different trace element signatures. Thus, we propose that these biogeochemical data could be used to identify pyrite that formed biogenetically either early in our planet's history or on other planets, particularly Mars. The potential for this approach is elevated because pyrite is common in diverse sedimentary settings, and its trace element content can be preserved despite secondary overprints up to greenschist facies, thus minimizing the concerns about remobilization that can plague traditional whole rock studies. We are also including in-situ sulfur isotope analysis to further refine our understanding of the complex signatures of ancient pyrite. Sulfur isotope data can point straightforwardly to the involvement of life, because pyrite in sediments is inextricably linked to bacterial sulfate reduction and its diagnostic isotopic expressions. In addition to analyzing pyrite of known biological origin formed in the modern and ancient oceans under a range of conditions, we are building a data set for pyrite formed by hydrothermal and metamorphic processes to minimize the risk of false positives in life detection. We have used Random Forests (RF), a machine learning statistical technique with proven efficiency for classifying large geological datasets, to classify pyrite into biotic and abiotic end members. Coupling the trace element and sulfur isotope data from our analyses with a large existing dataset from diverse settings has yielded 4500 analyses with 18 different variables. Our initial results reveal the promise of the RF approach, correctly identifying biogenic pyrite 97 percent of the time. We will continue to couple new in-situ S-isotope and trace element analyses of biogenic pyrite grains from modern and ancient environments, using cutting-edge microanalytical techniques, with new data from high temperature settings. Our ultimately goal

SAVANNAH RIVER TECHNOLOGY CENTER MONTHLY REPORT AUGUST 1992

Energy Technology Data Exchange (ETDEWEB)

Ferrell, J.M.

1999-06-21

'This monthly report summarizes Programs and Accomplishments of the Savannah River Technology Center in support of activities at the Savannah River Site. The following categories are addressed: Reactor, Tritium, Separations, Environmental, Waste Management, General, and Items of Interest.'

Distribution of sulfur and pyrite in coal seams from Kutai Basin (East Kalimantan, Indonesia): Implications for paleoenvironmental conditions

Energy Technology Data Exchange (ETDEWEB)

Widodo, Sri [Department of Mining Engineering, Moslem University of Indonesia, Jln. Urip Sumoharjo, Makassar (Indonesia); Oschmann, Wolfgang [Institute of Geosciece, J.W. Goethe-University, Altenhoeferallee 1, D-60438 Frankfurt a.M. (Germany); Bechtel, Achim; Sachsenhofer, Reinhard F. [Department of Applied Geoscience and Geophysics, University of Leoben, Peter-Tunner-Str.5, A-8700 Leoben (Austria); Anggayana, Komang [Department of Mining Engineering, Bandung Institute of Technology, Jln. Ganesa 10, I-40132 Bandung (Indonesia); Puettmann, Wilhelm [Institute of Atmospheric and Environmental Sciences, Dapartment of Analytical Enviromental Chemistry, J.W. Goethe-University, Altenhoeferallee 1, D-60438 Frankfurt a.M. (Germany)

2010-03-01

Thirteen Miocene coal samples from three active open pit and underground coal mines in the Kutai Basin (East Kalimantan, Indonesia) were collected. According to our microscopical and geochemical investigations, coal samples from Sebulu and Centra Busang coal mines yield high sulfur and pyrite contents as compared to the Embalut coal mine. The latter being characterized by very low sulfur (< 1%) and pyrite contents. The ash, mineral, total sulfur, iron (Fe) and pyrite contents of most of the coal samples from the Sebulu and Centra Busang coal mines are high and positively related in these samples. Low contents of ash, mineral, total sulfur, iron (Fe) and pyrite have been found only in sample TNT-32 from Centra Busang coal mine. Pyrite was the only sulfur form that we could recognize under reflected light microscope (oil immersion). Pyrite occurred in the coal as framboidal, euhedral, massive, anhedral and epigenetic pyrite in cleats/fractures. High concentration of pyrite argues for the availability of iron (Fe) in the coal samples. Most coal samples from the Embalut coal mine show lower sulfur (< 1 wt.%) and pyrite contents as found within Centra Busang and Sebulu coals. One exception is the coal sample KTD-38 from Embalut mine with total sulfur content of 1.41 wt.%. The rich ash, mineral, sulfur and pyrite contents of coals in the Kutai Basin (especially Centra Busang and Sebulu coals) can be related to the volcanic activity (Nyaan volcanic) during Tertiary whereby aeolian material was transported to the mire during or after the peatification process. Moreover, the adjacent early Tertiary deep marine sediment, mafic igneous rocks and melange in the center of Kalimantan Island might have provided mineral to the coal by uplift and erosion. The inorganic matter in the mire might also originate from the ground and surface water from the highland of central Kalimantan. (author)

Influence of heterotrophic microbial growth on biological oxidation of pyrite

Energy Technology Data Exchange (ETDEWEB)

Marchand, E.A.; Silverstein, J. [University of Nevada, Reno, NV (United States). Dept. of Civil Engineering

2002-12-15

Experiments were carried out to examine the possibility that enhanced growth of heterotrophic (non-iron-oxidising) bacteria would inhibit pyrite oxidation by Acidithiobacillus ferroxidans by out-competing the more slowly growing autotrophs for oxygen, nutrients or even attachment sites on the mineral surface. Glucose was added to microcosms containing pyrite, acidic mineral solution and cultures of A-ferrooxidans and Acidiphilium acidophilus under various experimental conditions. Results suggest that encouraging the growth of heterotrophic microorganisms under acid mine drainage conditions may be a feasible strategy for decreasing both the rate and the extent of sulfide mineral oxidation. 43 refs., 8 figs., 3 tabs.

Pyrite oxidation in the presence of hematite and alumina: I. Batch leaching experiments and kinetic modeling calculations.

Science.gov (United States)

Tabelin, Carlito Baltazar; Veerawattananun, Suchol; Ito, Mayumi; Hiroyoshi, Naoki; Igarashi, Toshifumi

2017-02-15

Pyrite is one of the most common and geochemically important sulfide minerals in nature because of its role in the redox recycling of iron (Fe). It is also the primary cause of acid mine drainage (AMD) that is considered as a serious and widespread problem facing the mining and mineral processing industries. In the environment, pyrite oxidation occurs in the presence of ubiquitous metal oxides, but the roles that they play in this process remain largely unknown. This study evaluates the effects of hematite (α-Fe 2 O 3 ) and alumina (α-Al 2 O 3 ) on pyrite oxidation by batch-reactor type experiments, surface-sensitive characterization of the oxidation layer and thermodynamic/kinetic modeling calculations. In the presence of hematite, dissolved sulfur (S) concentration dramatically decreased independent of the pH, and the formation of intermediate sulfoxy anionic species on the surface of pyrite was retarded. These results indicate that hematite minimized the overall extent of pyrite oxidation, but the kinetic model could not explain how this suppression occurred. In contrast, pyrite oxidation was enhanced in the alumina suspension as suggested by the higher dissolved S concentration and stronger infrared (IR) absorption bands of surface-bound oxidation products. Based on the kinetic model, alumina enhanced the oxidative dissolution of pyrite because of its strong acid buffering capacity, which increased the suspension pH. The higher pH values increased the oxidation of Fe 2+ to Fe 3+ by dissolved O 2 (DO) that enhanced the overall oxidative dissolution kinetics of pyrite. Copyright © 2016 Elsevier B.V. All rights reserved.

Operation Savannah: A Measure of SADF Decline, Resourcefulness ...

African Journals Online (AJOL)

Authorised amidst debilitating secrecy by a miscalculating South African government, Savannah demonstrated significant South African military equipment inadequacies, particularly in terms of artillery, armour and the need for an infantry combat vehicle. Savannah also gave hints of SADF strength residing in the ...

Floristic affinities of the lowland savannahs of Belize and southern Mexico.

Science.gov (United States)

Canché-Estrada, Idalia Arely; Ortiz-Díaz, Juan Javier; Tun-Garrido, Juan

2018-01-01

Environmental heterogeneity of Belize and southern Mexico savannahs as well as their geographical location suggest that these plant communities share floristic elements, making them conducive to a phytogeographical analysis. The aim of this study was to analyse the floristic affinities of nine savannahs of Belize and southern Mexico and to explain the similarities and differences amongst them. A binary data matrix containing 915 species was built based on the authors' own collections and on nine floristic lists already published. A second data matrix, consisting of 113 species representing trees, was also used since most literature on neotropical savannahs has focused on this life form. In addition, the ten most species-rich families as well as the characteristic species present in more than five savannahs were analysed. Floristic similarities were calculated using the Jaccard index. Dendrograms obtained in both types of analysis showed clusters with low similarity values, corresponding to geographic locations formed by the savannahs of Belize-Tabasco and the Yucatan Peninsula. The floristic affinities of the savannahs may be explained in terms of heterogeneity in climate and physiography. The Yucatan Peninsula and Belize-Tabasco groups have differences in climate type and the amount of rainfall. In addition, the Yucatan Peninsula savannahs are established at the bottom of karstic valleys, while the Belize and Tabasco savannahs develop on extensive flatlands. The savannahs of Oaxaca have the same climate type and amount of rainfall as those of the Yucatan Peninsula but they are distributed along peaks and the slopes of shale hills. Fabaceae and Poaceae mainly dominated the local floras with 121 and 116 species each; remarkably, Melastomataceae was absent in the Yucatan Peninsula and Oaxaca. Nine species occurred in five to seven savannahs, confirming that they are widespread in both Belize and southern Mexico, and the Neotropics. Geographic location and floristic

Comparative phylogeography of African savannah ungulates

DEFF Research Database (Denmark)

Lorenzen, Eline; Heller, Rasmus; Siegismund, Hans Redlef

2012-01-01

The savannah biome of sub-Saharan Africa harbours the highest diversity of ungulates (hoofed mammals) on Earth. In this review, we compile population genetic data from 19 codistributed ungulate taxa of the savannah biome and find striking concordance in the phylogeographic structuring of species...... and South-West Africa. Furthermore, differing Pleistocene evolutionary biogeographic scenarios are proposed for East and Southern Africa, supported by palaeoclimatic data and the fossil record. Environmental instability in East Africa facilitated several spatial and temporal refugia and is reflected...

Modelling the impacts of reoccurring fires in tropical savannahs using Biome-BGC.

Science.gov (United States)

Fletcher, Charlotte; Petritsch, Richard; Pietsch, Stephan

2010-05-01

Fires are a dominant feature of tropical savannahs and have occurred throughout history by natural as well as human-induced means. These fires have a profound influence on the landscape in terms of flux dynamics and vegetative species composition. This study attempts to understand the impacts of fire regimes on flux dynamics and vegetation composition in savannahs using the Biome-BGC model. The Batéké Plateau, Gabon - an area of savannah grasslands in the Congo basin, serves as a case-study. To achieve model validation for savannahs, data sets from stands with differing levels of past burning are used. It is hypothesised that the field measurements from those stands with lower-levels of past burning will correlate with the Biome-BGC model output, meaning that the model is validated for the savannah excluding fire regimes. However, in reality, fire is frequent in the savannah. Data on past fire events are available from the Moderate Resolution Imaging Spectroradiometer (MODIS) to provide the fire regimes of the model. As the field data-driven measurements of the burnt stands are influenced by fire in the savannah, this will therefore result in a Biome-BGC model validated for the impacts of fire on savannah ecology. The validated model can then be used to predict the savannah's flux dynamics under the fire scenarios expected with climate and/or human impact change.

Source and Enrichment of Toxic Elements in Coal Seams around Mafic Intrusions: Constraints from Pyrites in the Yuandian Coal Mine in Anhui, Eastern China

Directory of Open Access Journals (Sweden)

Yanfei An

2018-04-01

Full Text Available Pyrite, a mineral that can cause potential environmental issues in coal mining, is commonly found in coal seams around intrusions. In this paper, pyrites from the Yuandian Coal Mine (Huaibei Coalfield, Anhui, Eastern China were studied using SEM, Raman and LA-ICP-MS. The pyrite morphologic and geochemical data suggest that (1 four pyrite generations are present (framboidal sedimentary pyrites (Py I in the original coal, coarse-grained magmatic pyrites (Py II in the intruding diabase, fine-grained metamorphic pyrites (Py III in the intrusive contact aureole, and spheroid/vein hydrothermal pyrites (Py IV in the cokeite; and (2 concentrations of cobalt, nickel, arsenic, selenium, lead and copper in the metamorphic pyrites are much higher than the other pyrite generations. We propose that mafic magmatism is the main contributor of the toxic elements to the intrusion-related cokeite at Yuandian.

Molecular fossils of prokaryotes in ancient authigenic minerals: archives of microbial activity in reefs and mounds?

Science.gov (United States)

Heindel, Katrin; Birgel, Daniel; Richoz, Sylvain; Westphal, Hildegard; Peckmann, Jörn

2016-04-01

Molecular fossils (lipid biomarkers) are commonly used as proxies in organic-rich sediments of various sources, including eukaryotes and prokaryotes. Usually, molecular fossils of organisms transferred from the water column to the sediment are studied to monitor environmental changes (e.g., temperature, pH). Apart from these 'allochthonous' molecular fossils, prokaryotes are active in sediments and mats on the seafloor and leave behind 'autochthonous' molecular fossils in situ. In contrast to many phototrophic organisms, most benthic sedimentary prokaryotes are obtaining their energy from oxidation or reduction of organic or inorganic substrates. A peculiarity of some of the sediment-thriving prokaryotes is their ability to trigger in situ mineral precipitation, often but not only due to metabolic activity, resulting in authigenic rocks (microbialites). During that process, prokaryotes are rapidly entombed in the mineral matrix, where the molecular fossils are protected from early (bio)degradation. In contrast to other organic compounds (DNA, proteins etc.), molecular fossils can be preserved over very long time periods (millions of years). Thus, molecular fossils in authigenic mineral phases are perfectly suitable to trace microbial activity back in time. Among the best examples of molecular fossils, which are preserved in authigenic rocks are various microbialites, forming e.g. in phototrophic microbial mats and at cold seeps. Microbialite formation is reported throughout earth history. We here will focus on reefal microbialites form the Early Triassic and the Holocene. After the End-Permian mass extinction, microbialites covered wide areas on the ocean margins. In microbialites from the Griesbachian in Iran and Turkey (both Neotethys), molecular fossils of cyanobacteria, archaea, anoxygenic phototrophs, and sulphate-reducing bacteria indicate the presence of layered microbial mats on the seafloor, in which carbonate precipitation was induced. In association with

Paleoredoc and pyritization of soft-bodied fossils in the Ordovician Frankfort Shale of New York

DEFF Research Database (Denmark)

Farrell, Una C.; Briggs, Derek E. G.; Hammarlund, Emma U.

2013-01-01

Multiple beds in the Frankfort Shale (Upper Ordovician, New York State), including the original "Beecher's Trilobite Bed," yield fossils with pyritized soft-tissues. A bed-by-bed geochemical and sedimentological analysis was carried out to test previous models of soft-tissue pyritization...

46 CFR 7.75 - Savannah River/Tybee Roads.

Science.gov (United States)

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Savannah River/Tybee Roads. 7.75 Section 7.75 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES APPLICABLE TO THE PUBLIC BOUNDARY LINES Atlantic Coast § 7.75 Savannah River/Tybee Roads. A line drawn from the southwesternmost extremity of Braddock...

Element migration of pyrites during ductile deformation of the Yuleken porphyry Cu deposit (NW-China)

Science.gov (United States)

Hong, Tao; Xu, Xing-Wang; Gao, Jun; Peters, Stephen; Li, Jilei; Cao, Mingjian; Xiang, Peng; Wu, Chu; You, Jun

2017-01-01

The strongly deformed Yuleken porphyry Cu deposit (YPCD) occurs in the Kalaxiangar porphyry Cu belt (KPCB), which occupies the central area of the Central Asian Orogenic Belt (CAOB) between the Sawu’er island arc and the Altay Terrane in northern Xinjiang. The YPCD is one of several typical subduction-related deposits in the KPCB, which has undergone syn-collisional and post-collisional metallogenic overprinting. The YPCD is characterized by three pyrite-forming stages, namely a hydrothermal stage A (Py I), a syn-ductile deformation stage B (Py II) characterized by Cu-Au enrichment, and a fracture-filling stage C (Py III). In this study, we conducted systematic petrographic and geochemical studies of pyrites and coexist biotite, which formed during different stages, in order to constrain the physicochemical conditions of the ore formation. Euhedral, fragmented Py I has low Pb and high Te and Se concentration and Ni contents are low with Co/Ni ratios mostly between 1 and 10 (average 9.00). Py I is further characterized by enrichments of Bi, As, Ni, Cu, Te and Se in the core relative to the rim domains. Anhedral round Py II has moderate Co and Ni contents with high Co/Ni ratios >10 (average 95.2), and average contents of 46.5 ppm Pb and 5.80 ppm Te. Py II is further characterized by decreasing Bi, Cu, Pb, Zn, Ag, Te, Mo, Sb and Au contents from the rim to the core domains. Annealed Py III has the lowest Co content of all pyrite types with Co/Ni ratios mostly <0.1 (average 1.33). Furthermore, Py III has average contents of 3.31 ppm Pb, 1.33 ppm Te and 94.6 ppm Se. In addition, Fe does not correlate with Cu and S in the Py I and Py III, while Py II displays a negative correlation between Fe and Cu as well as a positive correlation between Fe and S. Therefore, pyrites which formed during different tectonic regimes also have different chemical compositions. Biotite geothermometer and oxygen fugacity estimates display increasing temperatures and oxygen

Bacterial leaching of pyritic gold ores

Energy Technology Data Exchange (ETDEWEB)

Gagliardi, F.M.; Cashion, J.D.; Brown, L.J. [Monash Univ., Clayton, VIC (Australia). Dept. of Physics; Jay, W.H. [Monash Univ., Clayton, VIC (Australia). Chemical Engineering Department

1996-12-31

The bacterial oxidation process is well known in nature but has only recently come under investigation as a viable and relatively clean method of gold recovery from ores. However there is currently little information about the process at an atomic scale. It is known that the bacterial attack progresses preferentially along grain boundaries which is precisely where the gold has been deposited from aqueous infiltration. Samples have been obtained from the Wiluna mine in Western Australia consisting of the original ore, 2 pre-treatments, and from six successive bacterial reactors. {sup 57}Fe Moessbauer spectra taken at room temperature show only two quadrupole split doublets which can be ascribed to pyrite, FeS{sub 2}, and arsenopyrite, FeAsS. However, the presence of any superparamagnetic oxide or oxyhydroxide species would be expected to give a spectrum very similar to that of pyrite and would be undetectable in small quantities. At a temperature of 5K, a broad magnetically split sextet is observable with a mean hyperfine field of approximately 50T. This field is characteristic of magnetically ordered ferric iron surrounded by an octahedron of oxygens. The intensity and characteristics of this subspectrum alters through the series and interpretations will be given on the oxidation products of the bacterial leaching

Bacterial leaching of pyritic gold ores

International Nuclear Information System (INIS)

Gagliardi, F.M.; Cashion, J.D.; Brown, L.J.; Jay, W.H.

1996-01-01

The bacterial oxidation process is well known in nature but has only recently come under investigation as a viable and relatively clean method of gold recovery from ores. However there is currently little information about the process at an atomic scale. It is known that the bacterial attack progresses preferentially along grain boundaries which is precisely where the gold has been deposited from aqueous infiltration. Samples have been obtained from the Wiluna mine in Western Australia consisting of the original ore, 2 pre-treatments, and from six successive bacterial reactors. 57 Fe Moessbauer spectra taken at room temperature show only two quadrupole split doublets which can be ascribed to pyrite, FeS 2 , and arsenopyrite, FeAsS. However, the presence of any superparamagnetic oxide or oxyhydroxide species would be expected to give a spectrum very similar to that of pyrite and would be undetectable in small quantities. At a temperature of 5K, a broad magnetically split sextet is observable with a mean hyperfine field of approximately 50T. This field is characteristic of magnetically ordered ferric iron surrounded by an octahedron of oxygens. The intensity and characteristics of this subspectrum alters through the series and interpretations will be given on the oxidation products of the bacterial leaching

Methane-related authigenic carbonates of the eastern Mediterranean Sea mud volcanoes and their possible relation to gas hydrate destabilisation

NARCIS (Netherlands)

Aloisi, G; Pierre, C; Rouchy, J.-M.; Foucher, J.P.; Woodside, J.M.; MEDINAUT scientific party, NN

2000-01-01

Nautile submersible investigations of mud volcanoes and brine seep areas of the eastern Mediterranean Sea during the MEDINAUT cruise in November 1998 discovered extensive areas of authigenic carbonate crusts associated with methane emissions. Carbonate crusts form pavements, round slabs and circular

Extensive occurrence and genesis of authigenic carbonates from Krishna-Godavari offshore basin (Bay of Bengal): Possible influence of methane hydrates occurrences.

Digital Repository Service at National Institute of Oceanography (India)

Kocherla, M.; Pillai, S.; Patil, D.J.

We report here the extensive occurrences of authigenic carbonate nodules/concretions from gas hydrate bearing sediments. Bulk mineralogical compositions by X-Ray diffractometry and EDS (Energy Dispersive Spectrum) analysis revealed...

Trace elements in fish from the Savannah River near Savannah River Nuclear Plant

International Nuclear Information System (INIS)

Koli, A.K.; Whitmore, R.

1983-01-01

A survey of trace element residues in fish from the Savannah River near Savannah River Nuclear Plant was undertaken in 1982. Fish muscle tissue was incubated by the wet digestion method. Fifteen trace elements were determined by flame atomic absorption spectrophotometry analysis of the digests. It was found that As, Se, Mg, Hg, Ca, Zn, and Fe levels were relatively higher than Pb, Cd, Ni, Co, Cr, and Mn in all fish species. In addition, in all fish species it seems that Pb, Cd, Ni, Co, Cr, and Mn levels were relatively higher than Cs and Cu. Cs and Cu levels were negligible in all fish species analyzed. Trace element levels found in these fish species were not high enough to render them dangerous for human consumption. (author)

Chemical and sulphur isotope compositions of pyrite in the ...

Indian Academy of Sciences (India)

sulphide mineralization and their chemical evo- lution in relative .... properties and chemical compositions. Electron ..... from the sulphide lode provide clues to the chang- ing fluid ..... Raymond O L 1996 Pyrite composition and ore geneis in.

Trace element mapping of pyrite from Archean gold deposits – A comparison between PIXE and EPMA

Energy Technology Data Exchange (ETDEWEB)

Agangi, A., E-mail: aagangi@uj.ac.za [University of Johannesburg, Department of Geology, Auckland Park 2006 (South Africa); Przybyłowicz, W., E-mail: przybylowicz@tlabs.ac.za [Materials Research Department, iThemba LABS, National Research Foundation, Somerset West 7129 (South Africa); AGH University of Science and Technology, Faculty of Physics & Applied Computer Science, Al. A. Mickiewicza 30, 30-059 Krakow (Poland); Hofmann, A., E-mail: ahofmann@uj.ac.za [University of Johannesburg, Department of Geology, Auckland Park 2006 (South Africa)

2015-04-01

Chemical zoning of pyrites can record the evolution of mineralising fluids at widely varying P–T conditions ranging from diagenesis to medium-grade metamorphism. If preserved, zoning can reveal growth textures, brecciation and veining, resorption and recrystallisation events, thus shedding light on the processes that contributed to ore formation. Chemical zoning of sulfides is invisible in optical microscopy, but can be studied by chemical etching, high-contrast back-scattering electron images, and elemental imaging. In this study we compared micro-PIXE and WDS-EPMA elemental maps on the chemically zoned pyrites in mineralised vein-bearing samples from the Sheba and Fairview gold mines in the Barberton Greenstone Belt, South Africa. Elemental images show complex distribution of trace elements, suggesting multiple events of pyrite crystallisation and gold deposition. EPMA maps show fine-scale variations reflecting growth and recrystallisation textures marked, in particular, by variations of As, Ni, and Co. In PIXE maps, gold occurs both as finely-distributed and discrete inclusions, suggesting incorporation in the pyrite structure as solid solution, and deposition as electrum inclusions, respectively. Micro-PIXE and EPMA provide complementary information, forming together a powerful tool to obtain information on chemical zoning of pyrites in ore deposits.

Surface structure-dependent pyrite oxidation in relatively dry and moist air: Implications for the reaction mechanism and sulfur evolution

Science.gov (United States)

Zhu, Jianxi; Xian, Haiyang; Lin, Xiaoju; Tang, Hongmei; Du, Runxiang; Yang, Yiping; Zhu, Runliang; Liang, Xiaoliang; Wei, Jingming; Teng, H. Henry; He, Hongping

2018-05-01

Pyrite oxidation not only is environmentally significant in the formation of acid mine (or acid rock) drainage and oxidative acidification of lacustrine sediment but also is a critical stage in geochemical sulfur evolution. The oxidation process is always controlled by the reactivity of pyrite, which in turn is controlled by its surface structure. In this study, the oxidation behavior of naturally existing {1 0 0}, {1 1 1}, and {2 1 0} facets of pyrite was investigated using a comprehensive approach combining X-ray photoelectron spectroscopy, diffuse reflectance Fourier transform infrared spectroscopy, and time-of-flight secondary-ion mass spectrometry with periodic density functional theoretical (DFT) calculations. The experimental results show that (i) the initial oxidation rates of both pyrite {1 1 1} and {2 1 0} are much greater than that of pyrite {1 0 0}; (ii) the initial oxidation rate of pyrite {2 1 0} is greater than that of pyrite {1 1 1} in low relative humidity, which is reversed in high relative humidity; and (iii) inner sphere oxygen-bearing sulfur species are originally generated from surface reactions and then converted to outer sphere species. The facet dependent rate law can be expressed as: r{hkl} =k{hkl}haP0.5(t + 1) - 0.5 , where r{hkl} is the orientation dependent reaction rate, k{hkl} is the orientation dependent rate constant, h is the relative humidity, P is the oxygen partial pressure, and t is the oxidation time in seconds. {1 1 1} is the most sensitive facet for pyrite oxidation. Combined with DFT theoretical investigations, water catalyzed electron transfer is speculated as the rate-limiting step. These findings disclose the structure-reactivity dependence of pyrite, which not only presents new insight into the mechanism of pyrite oxidation but also provides fundamental data to evaluate sulfur speciation evolution, suggesting that the surface structure sensitivity should be considered to estimate the reactivity at the mineral

Sulfur-oxidizing bacteria dominate the microbial diversity shift during the pyrite and low-grade pyrolusite bioleaching process.

Science.gov (United States)

Han, Yifan; Ma, Xiaomei; Zhao, Wei; Chang, Yunkang; Zhang, Xiaoxia; Wang, Xingbiao; Wang, Jingjing; Huang, Zhiyong

2013-10-01

The microbial ecology of the pyrite-pyrolusite bioleaching system and its interaction with ore has not been well-described. A 16S rRNA gene clone library was created to evaluate changes in the microbial community at different stages of the pyrite-pyrolusite bioleaching process in a shaken flask. The results revealed that the bacterial community was disturbed after 5 days of the reaction. Phylogenetic analysis of 16S rRNA sequences demonstrated that the predominant microorganisms were members of a genus of sulfur-oxidizing bacteria, Thiomonas sp., that subsequently remained dominant during the bioleaching process. Compared with iron-oxidizing bacteria, sulfur-oxidizing bacteria were more favorable to the pyrite-pyrolusite bioleaching system. Decreased pH due to microbial acid production was an important condition for bioleaching efficiency. Iron-oxidizing bacteria competed for pyrite reduction power with Mn(IV) in pyrolusite under specific conditions. These results extend our knowledge of microbial dynamics during pyrite-pyrolusite bioleaching, which is a key issue to improve commercial applications. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Efficient Solutions for New Homes Case Study: Savannah Gardens

Energy Technology Data Exchange (ETDEWEB)

None

2016-03-15

The Savannah Housing Department is leading sustainable and affordable housing development in Georgia. It partnered with Southface Energy Institute, a member of the U.S. Department of Energy’s Partnership for Home Innovation Building America research team, to seek cost-effective solutions for increasing the energy efficiency of the Savannah Housing Department’s standard single-family home plans in the Savannah Gardens Community. Based on engineering, cost, and constructability analyses, the combined research team chose to pilot two technologies to evaluate efficiency and comfort impacts for homeowners: a heat-pump water heater in an encapsulated attic and an insulated exterior wall sheathing.

Thin film preparation of semiconducting iron pyrite

Science.gov (United States)

Smestad, Greg P.; Ennaoui, Ahmed; Fiechter, Sebastian; Hofmann, Wolfgang; Tributsch, Helmut; Kautek, Wolfgang

1990-08-01

Pyrite (Fe52) has been investigated as a promising new absorber material for thin film solar cell applications because of its high optical absorption coefficient of 1OL cm1, and its bandgap of 0.9 to 1.0 eV. Thin layers have been prepared by Metal Organic Chemical Vapor Deposition, MOCVD, Chemical Spray Pyrolysis, CSP, Chemical Vapor Transport, CVT, and Sulfurization of Iron Oxide films, 510. It is postulated that for the material FeS2, if x is not zero, a high point defect concentration results from replacing 2 dipoles by single S atoms. This causes the observed photovoltages and solar conversion efficiencies to be lower than expected. Using the Fe-O-S ternary phase diagram and the related activity plots, a thermodynamic understanding is formulated for the resulting composition of each of these types of films. It is found that by operating in the oxide portion of the phase diagram, the resulting oxidation state favors pyrite formation over FeS. By proper orientation of the grains relative to the film surface, and by control of pinholes and stoichiometry, an efficient thin film photovolatic solar cell material could be achieved.

Recent solvent extraction experience at Savannah River

International Nuclear Information System (INIS)

Gray, L.W.; Burney, G.A.; Gray, J.H.; Hodges, M.E.; Holt, D.L.; Macafee, I.M.; Reif, D.J.; Shook, H.E.

1986-01-01

Tributyl phosphate-based solvent extraction processes have been used at Savannah River for more than 30 years to separate and purify thorium, uranium, neptunium, plutonium, americium, and curium isotopes. This report summarizes the advancement of solvent extraction technology at Savannah River during the 1980's. Topics that are discussed include equipment improvements, solvent treatment, waste reduction, and an improved understanding of the various chemistries in the process streams entering, within, and leaving the solvent extraction processes

Arsenopyrite and pyrite bioleaching: evidence from XPS, XRD and ICP techniques.

Science.gov (United States)

Fantauzzi, Marzia; Licheri, Cristina; Atzei, Davide; Loi, Giovanni; Elsener, Bernhard; Rossi, Giovanni; Rossi, Antonella

2011-10-01

In this work, a multi-technical bulk and surface analytical approach was used to investigate the bioleaching of a pyrite and arsenopyrite flotation concentrate with a mixed microflora mainly consisting of Acidithiobacillus ferrooxidans. X-ray diffraction, X-ray photoelectron spectroscopy (XPS) and X-ray-induced Auger electron spectroscopy mineral surfaces investigations, along with inductively coupled plasma-atomic emission spectroscopy and carbon, hydrogen, nitrogen and sulphur determination (CHNS) analyses, were carried out prior and after bioleaching. The flotation concentrate was a mixture of pyrite (FeS(2)) and arsenopyrite (FeAsS); after bioleaching, 95% of the initial content of pyrite and 85% of arsenopyrite were dissolved. The chemical state of the main elements (Fe, As and S) at the surface of the bioreactor feed particles and of the residue after bioleaching was investigated by X-ray photoelectron and X-ray excited Auger electron spectroscopy. After bioleaching, no signals of iron, arsenic and sulphur originating from pyrite and arsenopyrite were detected, confirming a strong oxidation and the dissolution of the particles. On the surfaces of the mineral residue particles, elemental sulphur as reaction intermediate of the leaching process and precipitated secondary phases (Fe-OOH and jarosite), together with adsorbed arsenates, was detected. Evidence of microbial cells adhesion at mineral surfaces was also produced: carbon and nitrogen were revealed by CHNS, and nitrogen was also detected on the bioleached surfaces by XPS. This was attributed to the deposition, on the mineral surfaces, of the remnants of a bio-film consisting of an extra-cellular polymer layer that had favoured the bacterial action. © Springer-Verlag 2011

Pyritization processes and greigite formation in the advancing sulfidization front in the Upper Pleistocene sediments of the Black Sea

DEFF Research Database (Denmark)

Neretin, LN; Bottcher, ME; Jørgensen, BB

2004-01-01

Pyritization in late Pleistocene sediments of the Black Sea is driven by sulfide formed during anaerobic methane oxidation. A sulfidization front is formed by the opposing gradients of sulfide and dissolved iron. The sulfidization processes are controlled by the diffusion flux of sulfide from above...... and by the solid reactive iron content. Two processes of diffusion-limited pyrite formation were identified. The first process includes pyrite precipitation with the accumulation of iron sulfide precursors with the average chemical composition of FeSn (n = 1.10-1.29), including greigite. Elemental sulfur...... and polysulfides, formed from H,S by a reductive dissolution of Fe(Ill)-containing minerals, serve as intermediates to convert iron sulfides into pyrite. In the second process, a "direct" pyrite precipitation occurs through prolonged exposure of iron-containing minerals to dissolved sulfide. Methane-driven sulfate...

40Ar/39Ar dating of pyrite

International Nuclear Information System (INIS)

York, D.; Masliwec, A.; Kuybida, P.; Hanes, J.A.; Hall, C.M.; Kenyon, W.J.; Spooner, E.T.C.; Scott, S.D.

1982-01-01

To overcome difficulties encountered in the customary method of determining the age of mineralization of sulphide ore deposits by analysing silicate material, the sulphide minerals themselves have been examined to see if they contained sufficient potassium and argon for 40 Ar/ 39 Ar age determination. Initial results indicate that this is the case for pyrite from the Geco ore body in northwestern Ontario, Canada. (U.K.)

Iron and manganese shuttles control the formation of authigenic phosphorus minerals in the euxinic basins of the Baltic Sea

NARCIS (Netherlands)

Jilbert, T.|info:eu-repo/dai/nl/304835714; Slomp, C.P.|info:eu-repo/dai/nl/159424003

2013-01-01

Microanalysis of epoxy resin-embedded sediments is used to demonstrate the presence of authigenic iron (Fe) (II) phosphates and manganese (Mn)-calcium (Ca)-carbonate-phosphates in the deep euxinic basins of the Baltic Sea. These minerals constitute major burial phases of phosphorus (P) in this area,

Distribution of uranium in kolm. Evidence from backscattered electron imagery

Energy Technology Data Exchange (ETDEWEB)

Parnell, J [Dep. of Geology, Belfast (Northern Ireland)

1985-02-06

The distribution of uranium in kolm from Upper Cambriam alum shales has been studied using backscattered electron imagery, and found to be concentrated in discrete mineral phases. Authigenic minerals in kolm include pyrite, galena, and a cerium-bearing mineral referable to monazite. Uranium occurs within the monazite and generally shows a close relationship with phosphorus. Uranium bearing monazite has also been identified within the host alum shale.

Savannah River Plant incinerator demonstration

International Nuclear Information System (INIS)

Lewandowski, K.E.

1983-01-01

A full-scale incineration process was demonstrated at the Savannah River Laboratory (SRL) using nonradioactive waste. From October 1981 through September 1982, 15,700 kilograms of solid waste and 5.7 m 3 of solvent were incinerated. Emissions of off-gas components (NO/sub x/, SO 2 , CO, and particulates) were well below South Carolina state standards. Volume reductions of 20:1 for solid waste and 7:1 for Purex solvent/lime slurry were achieved. The process has been relocated and upgraded by the Savannah River Plant to accept low-level beta-gamma combustibles. During a two-year demonstration, the facility will incinerate slightly radioactive ( 3 ) solvent and suspect level (< 1 mR/h at 0.0254 meter) solid wastes. This demonstration will begin in early 1984

Guide to Savannah River Laboratory Analytical Services Group

Energy Technology Data Exchange (ETDEWEB)

1990-04-01

The mission of the Analytical Services Group (ASG) is to provide analytical support for Savannah River Laboratory Research and Development Programs using onsite and offsite analytical labs as resources. A second mission is to provide Savannah River Site (SRS) operations with analytical support for nonroutine material characterization or special chemical analyses. The ASG provides backup support for the SRS process control labs as necessary.

Guide to Savannah River Laboratory Analytical Services Group

International Nuclear Information System (INIS)

1990-04-01

The mission of the Analytical Services Group (ASG) is to provide analytical support for Savannah River Laboratory Research and Development Programs using onsite and offsite analytical labs as resources. A second mission is to provide Savannah River Site (SRS) operations with analytical support for nonroutine material characterization or special chemical analyses. The ASG provides backup support for the SRS process control labs as necessary

Degradation of Anthraquinone Dye Reactive Blue 4 in Pyrite Ash Catalyzed Fenton Reaction

Directory of Open Access Journals (Sweden)

Milena Becelic-Tomin

2014-01-01

Full Text Available Pyrite ash (PA is created by burning pyrite in the chemical production of sulphuric acid. The high concentration of iron oxide, mostly hematite, present in pyrite ash, gives the basis for its application as a source of catalytic iron in a modified Fenton process for anthraquinone dye reactive blue 4 (RB4 degradation. The effect of various operating variables such as catalyst and oxidant concentration, initial pH and RB4 concentration on the abatement of total organic carbon, and dye has been assessed in this study. Here we show that degradation of RB4 in the modified Fenton reaction was efficient under the following conditions: pH=2.5; [PA]0=0.2 g L−1; [H2O2]0=5 mM and initial RB4 concentration up to 100 mg L−1. The pyrite ash Fenton reaction can overcome limitations observed from the classic Fenton reaction, such as the early termination of the Fenton reaction. Metal (Pb, Zn, and Cu content of the solution after the process suggests that an additional treatment step is necessary to remove the remaining metals from the water. These results provide basic knowledge to better understand the modified, heterogeneous Fenton process and apply the PA Fenton reaction for the treatment of wastewaters which contains anthraquinone dyes.

Building America Case Study: Savannah Gardens, Savannah, Georgia

Energy Technology Data Exchange (ETDEWEB)

2016-03-01

Southface Energy Institute (Southface) partnered with owners and/or builders with various market constraints and ultimate goals for three projects in different climate zones: Savannah, GA (CZ 2), Clemson, SC (CZ 3), and LaFayette, GA (CZ 4). This report documents the design process, computational energy modeling, construction, envelope performance metrics, long-term monitoring results, and successes and failures of the design and execution of these high performance homes. The three bedroom/two bathroom test home in Savannah Gardens on an elevated slab foundation has a semi-conditioned, encapsulated attic. A neighboring home built to EarthCraft specifications was also monitored as a control for exterior foam insulation and a heat pump water heater (HPWH). For the JMC Patrick Square, a single-story project in Clemson, the small-scale production builder wanted to increase their level of energy efficiency beyond their current green building practices, including bringing ducts into conditioned space. Through a combination of upgrade measures the team met this goal and achieved many Zero Energy Ready Home requirements. LaFayette Housing Authority undertook a development of 30 affordable rental housing units in 15 duplexes in LaFayette, GA. Because they would be long-term owners, their priorities were low utility bills for the residents and durable, maintainable buildings. The team employed BEopt to optimize building envelope and systems choices, including 2x6 advanced framed walls, insulated slab, and heat pump water heater in a utility closet which was ducted to/from an encapsulated attic.

Mineralization and trace element distribution in pyrite using EMPA in exploration drill holes from Cheshmeh Zard gold district, Khorasan Razavi Province, Iran

Directory of Open Access Journals (Sweden)

Zahra Alaminia

2015-10-01

Full Text Available Introduction Pyrite is the most abundant sulfide mineral in low sulfidation ore deposits. Experimental studies have shown that low-temperature ( 200°C from hydrothermal or metamorphic fluids (Butler and Rickard, 2000. Framboidal pyrite mostly occurs in sedimentary environments, though it could also form during metamorphism and hydrothermal alteration (Scott et al., 2009. The pyrite formed tends to be enriched in various trace elements such as Au and As. For this study we have combined the geology, alteration, mineralization with recent studies of the description of the deposit from core logging and underground mapping and geochemistry in the CheshmehZard gold district and also investigated the compositional variation and textural differences between pyrite types. This study is based on the results of our alteration and mineralization mapping and detailed logging of 1937.8 m of drill core. Materials and Methods Geology, hydrothermal alteration and mineralization were examined in drill holes along several cross sections. Host-rock alteration minerals and veins were determined for 11 samples using standard X-ray diffraction (XRD and X-ray fluorescence spectrometry (XRF techniques. Polished sections were studied by reflected light microscopy and backscattered electron images (BSE. In this study, the trace-element composition of pyrite samples from the Au-III vein system was obtained using electron microprobe analyzer (EMPA data. All analyseswere carried out at the department of Materials Engineering and Physics of the University of Salzburg in Austria. The EMPA measurements and BSE imaging were made using a JXA-8600 electron microprobe. Spot analyses of 30 pyrite grains from CheshmehZard are given in Table 1. Results The study area is located in the north of Khorasan Razavi Province 45 km to the south of Neyshabour. The area near CheshmehZard could become important as a site of economically significant gold mineralization. Six gold-bearing vein

Food production and consumption near the Savannah River Site

Energy Technology Data Exchange (ETDEWEB)

Hamby, D.M.

1991-12-31

Routine operations at the Savannah River Site (SRS) result in the release of radionuclides to the atmosphere and to the Savannah River. The resulting radiological doses to the off-site maximum individual and the 80-km population are estimated on a yearly basis. These estimates are generated using dose models prescribed in the NRC Reg. Guide 1.109 for the commercial nuclear power industry. A study of land and water usage characteristics in the region of the Savannah River Site has been conducted to determine site-specific values of the NRC dose model parameters. The study`s scope included local characteristics of meat, milk, vegetable production; Savannah River recreational activities and fish harvests; meat, milk, vegetable, and seafood consumption rates; and Savannah River drinking-water populations. Average and maximum consumption rates of beef, milk, vegetables, and fish have been determined for individuals residing in the southern United States. The study suggest that many of the consumption rates provided by the NRC may not be appropriate for residents of the South. Average consumption rates are slightly higher than the defaults provided by the NRC. Maximum consumption rates, however, are typically lower than NRC values. Agricultural productivity in the SRS region was found to be quite different than NRC recommendations. Off-site doses have been predicted using both NRC and SRS parameter values to demonstrate the significance of site-specific data.

Food production and consumption near the Savannah River Site

Energy Technology Data Exchange (ETDEWEB)

Hamby, D.M.

1991-01-01

Routine operations at the Savannah River Site (SRS) result in the release of radionuclides to the atmosphere and to the Savannah River. The resulting radiological doses to the off-site maximum individual and the 80-km population are estimated on a yearly basis. These estimates are generated using dose models prescribed in the NRC Reg. Guide 1.109 for the commercial nuclear power industry. A study of land and water usage characteristics in the region of the Savannah River Site has been conducted to determine site-specific values of the NRC dose model parameters. The study's scope included local characteristics of meat, milk, vegetable production; Savannah River recreational activities and fish harvests; meat, milk, vegetable, and seafood consumption rates; and Savannah River drinking-water populations. Average and maximum consumption rates of beef, milk, vegetables, and fish have been determined for individuals residing in the southern United States. The study suggest that many of the consumption rates provided by the NRC may not be appropriate for residents of the South. Average consumption rates are slightly higher than the defaults provided by the NRC. Maximum consumption rates, however, are typically lower than NRC values. Agricultural productivity in the SRS region was found to be quite different than NRC recommendations. Off-site doses have been predicted using both NRC and SRS parameter values to demonstrate the significance of site-specific data.

Uranium-series dated authigenic carbonates and Acheulian sites in southern Egypt

International Nuclear Information System (INIS)

Szabo, B.J.; McHugh, W.P.; Schaber, G.G.; Breed, C.S.; Haynes, C.V.

1989-01-01

Field investigations in southern Egypt have yielded Acheulian artifacts in situ in authigenic carbonate deposits (CaCO 3 -cemented alluvium) along the edges of now-aggraded paleovalleys (Wadi Arid and Wadi Safsaf). Uranium-series dating of 25 carbonate samples from various localities as far apart as 70 kilometers indicates that widespread carbonate deposition occurred about 45, 141 and 212 ka (thousand years ago). Most of the carbonate appears to have been precipitated from groundwater, which suggests that these three episodes of deposition may be related to late Pleistocene humid climates that facilitated human settlement in this now hyperarid region. Carbonate cements from sediments containing Acheulian artifacts provide a minimum age of 212 ka for early occupation of the paleovalleys. 16 refs., 3 figs., 2 tabs

Rheology of Savannah River site tank 42 HLW radioactive sludge

International Nuclear Information System (INIS)

Ha, B.C.

1997-01-01

Knowledge of the rheology of the radioactive sludge slurries at the Savannah River Site is necessary in order to ensure that they can be retrieved from waste tanks and processed for final disposal. At Savannah River Site, Tank 42 sludge represents on of the first HLW radioactive sludges to be vitrified in the Defense Waste Processing Facility. The rheological properties of unwashed Tank 42 sludge slurries at various solids concentrations were measured remotely in the Shielded Cells at the Savannah River Technology Center using a modified Haake Rotovisco viscometer

Savannah River Technology Center

International Nuclear Information System (INIS)

1993-01-01

This is a monthly progress report from the Savannah River Laboratory for the month of January 1993. It has sections with work in the areas of reactor safety, tritium processes and absorption, separations programs and wastes, environmental concerns and responses, waste management practices, and general concerns

Mobile teleoperator research at Savannah River Laboratory

International Nuclear Information System (INIS)

Byrd, J.S.

1985-01-01

A Robotics Technology Group was organized at Savannah River Laboratory to employ modern automation and robotics for applications at the Savannah River site. Several industrial robots have been installed in plant processes. Other robotics systems are under development in the laboratories, including mobile teleoperators for general remote tasks and emergency response operations. This paper discusses present work on a low-cost wheeled mobile vehicle, a modular light duty manipulator arm, a large gantry telerobot system, and a high technology six-legged walking robot with a teleoperated arm

Incineration demonstration at Savannah River

International Nuclear Information System (INIS)

Lewandowski, K.E.; Becker, G.W.; Mersman, K.E.; Roberson, W.A.

1983-01-01

A full-scale incineration process for Savannah River Plant (SRP) low level beta-gamma combustible waste was demonstrated at the Savannah River Laboratory (SRL) using nonradioactive wastes. From October 1981 through September 1982, 15,700 kilograms of solid waste and 5.7 m 3 of solvent were incinerated. Emissions of off-gas components (NO/sub x/, SO 2 , CO, and particulates) were well below South Carolina state standards. Volume reductions of 20:1 for solid waste and 7:1 for Purex solvent/lime slurry were achieved. Presently, the process is being upgraded by SRP to accept radioactive wastes. During a two-year SRP demonstration, the facility will be used to incinerate slightly radioactive ( 3 ) solvent and suspect level (<1 mR/hr at 0.0254 meter) solid wastes

Intensive archaeological survey of the proposed Savannah River Ecology Laboratory Conference Center and Educational Facility, Savannah River Site, Aiken County, South Carolina

Energy Technology Data Exchange (ETDEWEB)

Stephenson, K.; Crass, D.C.; Sassaman, K.E.

1993-02-01

Documented in this report are the methods and results of an intensive archaeological survey for the proposed University of Georgia Savannah River Ecology Laboratory (SREL) Conference Center and Educational Facility on the DOE Savannah River Site (SRS). Archaeological investigations conducted by the Savannah River Archaeological Research Program (SRARP) on the 70-acre project area and associated rights-of-way consisted of subsurface testing at two previously recorded sites and the discovery of one previously unrecorded site. The results show that 2 sites contain archaeological remains that may yield significant information about human occupations in the Aiken Plateau and are therefore considered eligible for nomination to the National Register of Historic Places. Adverse impacts to these sites can be mitigated through avoidance.

Unpacking paleoenvironmental change across OAE2 using paired d34S records of pyrite and organic matter

Science.gov (United States)

Raven, M. R.; Gomes, M.; Fike, D. A.

2017-12-01

Pyrite sulfur isotopes have proven to be a powerful tool for reconstructing major changes in global redox state and the emergence of microbial metabolisms. Still, pyrite can be a challenging archive, as its formation depends on the availability of reactive iron species and can occur over multiple generations of sedimentary processes. Accordingly, pyrite δ34S records commonly have large point-to-point variability reflecting local processes. By pairing pyrite δ34S records with those of coexisting organic matter (OM), including both kerogens and extractable bitumens, we can begin to parse the various potential causes of this variability and gain greater insights into changes in the sedimentary paleoenvironment. Here, we present the first collection of records of OM δ34S for the Cretaceous, focusing on sections spanning Ocean Anoxic Event 2 (OAE2, 94 Mya), a period of globally widespread marine anoxia and carbon cycle disruption. In carbonates and shales from OAE2 in Pont d'Issole, France, pyrite and OM δ34S values vary in parallel throughout most of the section, consistent with their shared sulfide source. There are also distinct exceptions: In one interval, an excursion in pyrite δ34S is entirely absent from the organic sulfur record but associated with unusual organic sulfur redox speciation (by XAS), potentially reflecting later exposure to oxic porewaters. Across the core interval of shale deposition during OAE2, the offset between pyrite and OM δ34S values declines smoothly from +17.4 to -7.9‰, which we interpret in terms of changes in the speciation of detrital iron minerals that may have regional implications. We then compare these results with data for other well-characterized OAE2 sections, including Cismon (Italy), Tarfaya (Morocco), and the Demerara Rise (offshore Brazil), which represent environments with a variety of apparent redox states. These paired pyrite - OM δ34S profiles yield new information about how the local and global forcings

Overview of environmental research at the Savannah River Laboratory

International Nuclear Information System (INIS)

Harvey, R.S.

1977-01-01

Research in the environmental sciences by the Savannah River Laboratory (SRL) has the general objective of improving our understanding of transport through ecosystems and functional processes within ecosystems. With increased understanding, the basis for environmental assessments can be improved for releases from the Savannah River Plant or from the power industry of the southeastern United States

Electrochemical Properties for Co-Doped Pyrite with High Conductivity

Directory of Open Access Journals (Sweden)

Yongchao Liu

2015-09-01

Full Text Available In this paper, the hydrothermal method was adopted to synthesize nanostructure Co-doped pyrite (FeS2. The structural properties and morphology of the synthesized materials were characterized using X-ray diffraction (XRD and scanning electron microscopy (SEM, respectively. Co in the crystal lattice of FeS2 could change the growth rate of different crystal planes of the crystal particles, which resulted in various polyhedrons with clear faces and sharp outlines. In addition, the electrochemical performance of the doping pyrite in Li/FeS2 batteries was evaluated using the galvanostatic discharge test, cyclic voltammetry and electrochemical impedance spectroscopy. The results showed that the discharge capacity of the doped material (801.8 mAh·g−1 with a doping ratio of 7% was significantly higher than that of the original FeS2 (574.6 mAh·g−1 because of the enhanced conductivity. Therefore, the doping method is potentially effective for improving the electrochemical performance of FeS2.

Pen Branch Delta and Savannah River Swamp Hydraulic Model

International Nuclear Information System (INIS)

Chen, K.F.

1999-01-01

The proposed Savannah River Site (SRS) Wetlands Restoration Project area is located in Barnwell County, South Carolina on the southwestern boundary of the SRS Reservation. The swamp covers about 40.5 km2 and is bounded to the west and south by the Savannah River and to the north and east by low bluffs at the edge of the Savannah River floodplain. Water levels within the swamp are determined by stage along the Savannah River, local drainage, groundwater seepage, and inflows from four tributaries, Beaver Dam Creek, Fourmile Branch, Pen Branch, and Steel Creek. Historic discharges of heated process water into these tributaries scoured the streambed, created deltas in the adjacent wetland, and killed native vegetation in the vicinity of the delta deposits. Future releases from these tributaries will be substantially smaller and closer to ambient temperatures. One component of the proposed restoration project will be to reestablish indigenous wetland vegetation on the Pen Branch delta that covers about 1.0 km2. Long-term predictions of water levels within the swamp are required to determine the characteristics of suitable plants. The objective of the study was to predict water levels at various locations within the proposed SRS Wetlands Restoration Project area for a range of Savannah River flows and regulated releases from Pen Branch. TABS-MD, a United States Army Corps of Engineer developed two-dimensional finite element open channel hydraulic computer code, was used to model the SRS swamp area for various flow conditions

Oxygen isotope evidence for sorption of molecular oxygen to pyrite surface sites and incorporation into sulfate in oxidation experiments

International Nuclear Information System (INIS)

Tichomirowa, Marion; Junghans, Manuela

2009-01-01

Experiments were conducted to investigate (i) the rate of O-isotope exchange between SO 4 and water molecules at low pH and surface temperatures typical for conditions of acid mine drainage (AMD) and (ii) the O- and S-isotope composition of sulfates produced by pyrite oxidation under closed and open conditions (limited and free access of atmospheric O 2 ) to identify the O source/s in sulfide oxidation (water or atmospheric molecular O 2 ) and to better understand the pyrite oxidation pathway. An O-isotope exchange between SO 4 and water was observed over a pH range of 0-2 only at 50 deg. C, whereas no exchange occurred at lower temperatures over a period of 8 a. The calculated half-time of the exchange rate for 50 deg. C (pH = 0 and 1) is in good agreement with former experimental data for higher and lower temperatures and excludes the possibility of isotope exchange for typical AMD conditions (T ≤ 25 deg. C, pH ≥ 3) for decades. Pyrite oxidation experiments revealed two dependencies of the O-isotope composition of dissolved sulfates: O-isotope values decreased with longer duration of experiments and increasing grain size of pyrite. Both changes are interpreted as evidence for chemisorption of molecular O 2 to pyrite surface sites. The sorption of molecular O 2 is important at initial oxidation stages and more abundant in finer grained pyrite fractions and leads to its incorporation in the produced SO 4 . The calculated bulk contribution of atmospheric O 2 in the dissolved SO 4 reached up to 50% during initial oxidation stages (first 5 days, pH 2, fine-grained pyrite fraction) and decreased to less than 20% after about 100 days. Based on the direct incorporation of molecular O 2 in the early-formed sulfates, chemisorption and electron transfer of molecular O 2 on S sites of the pyrite surface are proposed, in addition to chemisorption on Fe sites. After about 10 days, the O of all newly-formed sulfates originates only from water, indicating direct interaction

Simulated aerobic pedogenesis in pyritic overburden with a positive acid-base account

Energy Technology Data Exchange (ETDEWEB)

Doolittle, J.J.; Hossner, L.R.; Wilding, L.P. (South Dakota State University, Brookings, SD (United States). Dept. of Plant Science)

Reclamation of surface-mined land is often hindered by the excess salts and acidity produced by the weathering of pyritic overburden. This study was conducted to document the initial transformations that occur when pyritic overburden containing excess acid neutralizing potential is used as parent material in minesoil construction. An overburden containing 0.8% FeS[sub 2] (pyrite) and 1.6% inorganic carbonate (predominantly dolomite) was collected from the highwall of an active lignite surface mine in Panola County, Texas. The overburden was lightly crushed through a 13-mm sieve and packed into three replicate lysimeters (0.75 by 0.75 by 1.2 m). The lysimeters were leached monthly with 63.5 mm of deionized water for 24 mo. The initial material had a pH of 8.3 and an excess acid neutralizing potential. Progressive FeS[sub 2] oxidation released H[sub 2]SO[sub 4], and the pH decreased to 6.8. The dolomite dissolved, neutralizing the acidity, with subsequent release of Ca and Mg ions into solution. Leachate Ca[sup 2+] and SO[sub 4][sup 2-] concentrations exceeded the ion activity product of gypsum in the lower 60 cm of the lysimeters. Thin-section analysis revealed that gypsum crystals precipitated along margins of residual pyrite particles and in conductive vughs and channels. The continued accumulation of gypsum in minesoil development could eventually lead to the formation of a gypsic or a petrogypsic horizon. A restrictive layer such as this would decrease vertical movement of water and O[sub 2] which would reduce vegetative growth, increase runoff and erosion, and thus increase the probability of reclamation failure.

Radiometric analyses of floodplain sediments at the Savannah River Plant

International Nuclear Information System (INIS)

Lower, M.W.

1987-09-01

A Comprehensive Cooling Water Study to assess the effects of reactor cooling water discharges and related reactor area liquid releases to onsite streams and the nearby Savannah River has been completed at the US Department of Energy's Savannah River Plant (SRP). Extensive radiometric analyses of man-made and naturally occurring gamma-emitting radionuclides were measured in floodplain sediment cores extracted from onsite surface streams at SRP and from the Savannah River. Gamma spectrometric analyses indicate that reactor operations contribute to floodplain radioactivity levels slightly higher than levels associated with global fallout. In locations historically unaffected by radioactive releases from SRP operations, Cs-137 concentrations were found at background and fallout levels of about 1 pCi/g. In onsite streams that provided a receptor for liquid radioactive releases from production reactor areas, volume-weighted Cs-137 concentrations ranged by core from background levels to 55 pCi/g. Savannah River sediments contained background and atmospheric fallout levels of Cs-137 only. 2 refs., 5 figs

The future distribution of the savannah biome: model-based and biogeographic contingency.

Science.gov (United States)

Moncrieff, Glenn R; Scheiter, Simon; Langan, Liam; Trabucco, Antonio; Higgins, Steven I

2016-09-19

The extent of the savannah biome is expected to be profoundly altered by climatic change and increasing atmospheric CO2 concentrations. Contrasting projections are given when using different modelling approaches to estimate future distributions. Furthermore, biogeographic variation within savannahs in plant function and structure is expected to lead to divergent responses to global change. Hence the use of a single model with a single savannah tree type will likely lead to biased projections. Here we compare and contrast projections of South American, African and Australian savannah distributions from the physiologically based Thornley transport resistance statistical distribution model (TTR-SDM)-and three versions of a dynamic vegetation model (DVM) designed and parametrized separately for specific continents. We show that attempting to extrapolate any continent-specific model globally biases projections. By 2070, all DVMs generally project a decrease in the extent of savannahs at their boundary with forests, whereas the TTR-SDM projects a decrease in savannahs at their boundary with aridlands and grasslands. This difference is driven by forest and woodland expansion in response to rising atmospheric CO2 concentrations in DVMs, unaccounted for by the TTR-SDM. We suggest that the most suitable models of the savannah biome for future development are individual-based dynamic vegetation models designed for specific biogeographic regions.This article is part of the themed issue 'Tropical grassy biomes: linking ecology, human use and conservation'. © 2016 The Author(s).

Savannah River Site 1996 epidemiologic surveillance report

International Nuclear Information System (INIS)

2000-01-01

This report provides a summary of epidemiologic surveillance data collected from Savannah River Site from January 1, 1996 through December 31, 1996. The data were collected by a coordinator at Savannah River Site and submitted to the Epidemiologic Surveillance Data Center located at Oak Ridge Institute for Science and Education, where quality control procedures and preliminary data analyses were carried out. The analyses were interpreted and the final report prepared by the DOE Office of Epidemiologic Studies. The information in this report provides highlights of the data analyses conducted on the 1996 data collected from Savannah River Site. The main sections of the report include: work force characteristics; absences due to injury or illness lasting 5 or more consecutive workdays; workplace illnesses, injuries, and deaths that were reportable to the Occupational Safety and Health Administration (''OSHA-recordable'' events); and disabilities and deaths among current workers. The 1996 report includes a new section on time trends that provides comparative information on the health of the work force from 1994 through 1996

Savannah River Site 1997 epidemiologic surveillance report

International Nuclear Information System (INIS)

2000-01-01

This report provides a summary of epidemiologic surveillance data collected from Savannah River Site from January 1, 1997 through December 31, 1997. The data were collected by a coordinator at Savannah River Site and submitted to the Epidemiologic Surveillance Data Center located at Oak Ridge Institute for Science and Education, where quality control procedures and preliminary data analyses were carried out. The analyses were interpreted and the final report prepared by the DOE Office of Epidemiologic Studies. The information in this report provides highlights of the data analyses conducted on the 1997 data collected from Savannah River Site. The main sections of the report include: work force characteristics; absences due to injury or illness lasting 5 or more consecutive workdays; workplace illnesses, injuries, and deaths that were reportable to the Occupational Safety and Health Administration (''OSHA-recordable'' events); and disabilities and deaths among current workers. The 199 7 report includes a section on time trends that provides comparative information on the health of the work force from 1994 through 1997

Surface Wind Gust Statistics at the Savannah River Site

International Nuclear Information System (INIS)

Weber, A.H.

2001-01-01

The Atmospheric Technologies Group (ATG) of the Savannah River Technology Center (SRTC) collects meteorological data for many purposes at the Savannah River Site (SRS) including weather forecasting. This study focuses on wind gusts and also, to a lesser degree, turbulence intensities that occur in fair weather conditions near the surface over time periods from 1 hour to one week (168 hours)

Effect of thermal effluents from the Savannah River Plant on leaf decomposition rates in onsite creeks and the Savannah River

International Nuclear Information System (INIS)

Sadowski, P.W.; Matthews, R.A.

1986-06-01

Sweet gum and sycamore leaf packs were packs were placed in a thermally stressed, a post-thermal, and an ambient stream located on the Savannah River Plant, South Carolina, and in the Savannah River below the mouth of each stream. Processing rates for the leaf packs were determined over a 77-day period from December 1982 to March 1983. Due to inundation of the sampling sites by river flooding, temperatures in the stream receiving thermal effluent were reduced after day 24. Sweet gum leaves decomposed considerably faster than did sycamore leaves, particularly in the thermal creek. An exponential decay model was used to demonstrate significant differences in loss of ash-free dry weight from leaf packs in thermally stressed and nonthermal creeks. Differences in leaf processing rates between creek sites were greatest during periods of therma stress. Within each leaf species, leaf processing rates were not significantly different between nonthermal sites, nor between sites in the Savannah River

Gelatin/DMSO. A new approach to enhancing the performance of a pyrite electrode in a lithium battery

Energy Technology Data Exchange (ETDEWEB)

Montoro, L.A.; Rosolen, J.M. [Department of Chemistry, FFCLRP-University of Sao Paulo, 14040-901 Ribeirao Preto, Sao Paulo (Brazil)

2003-04-01

We have studied the electrochemical behavior of natural pyrite (FeS{sub 1.9}, n-type semiconductor) treated nonaqueously with dimethylsulfoxide (DMSO) solvent and also with a gelatin/DMSO solution. Composite electrodes (comprised of pyrite, polyvinilidene fluoride, polyethylene oxide and carbon) were characterized in a lithium cell at room temperature by cyclic voltammetry and galvanostatic measurements; the electrolyte used was LiPF{sub 6} in a solution of ethylene carbonate and dimethyl carbonate (1 mol l{sup -1}). The gelatin/DMSO treatment greatly improved the reversible specific capacity of a pyrite electrode. For galvanostatic discharge/charge at a current density of 0.4 mA cm{sup -2} and between voltage limits of 3.2 and 1.1 V, its reversible specific capacity at the 15th cycle equaled 275 mA h g{sup -1}, an impressive value compared to less than 25 mA h g{sup -1} for a pristine pyrite electrode.

Savannah River Laboratory data banks for risk assessment

International Nuclear Information System (INIS)

Durant, W.S.

1984-01-01

The Savannah River Laboratory maintains a series of computerized data banks primarily as an aid in probabilistic risk assessment studies for the Savannah River Plant (SRP) facilities. These include component failure rates, generic incidents, and reports of specific deviations from normal operating conditions. In addition to providing data for probability studies, these banks have served as a valuable aid in trend analyses, equipment histories, process hazards analyses, consequence assessments, incident audits, process problem solving, and training

Pyrite thermochemistry, ash agglomeration, and char fragmentation during pulverized coal combustion

Energy Technology Data Exchange (ETDEWEB)

Akan-Etuk, A.; Diaz, R.; Niksa, S.

1991-10-01

The objective of the present work is to introduce an experimental program that will eventually lead to time-resolved iron ash composition over the technological operating domain. The preceding literature survey suggests two important stipulations on any such experimental program. The first stipulation is that good control must be established over the operating conditions, to accurately quantify their effects. The other is that data must be obtained rapidly, to thoroughly cover the important operating domain. This work presents a series of studies that has characterized the desulfurization of pyrite during the early stages of combustion. An experimental system was established and used to monitor the effects of oxygen, temperature, and residence time on the evolution of condensed phase products of the combustion of pure pyrite. (VC)

Savannah River Site Environmental Report for 1997 Summary

International Nuclear Information System (INIS)

Arnett, M.

1998-01-01

The Savannah River Site (SRS) publishes an environmental report each year to provide environmental monitoring and surveillance results to the U. S. Department of Energy (DOE), the public, Congress, state and federal regulators, universities, local governments, the news media, and environmental and civic groups. The Savannah River Site Environmental Report for 1997 (WSRC-TR-97-00322) contains detailed information on site operations, environmental monitoring and surveillance programs, environmental compliance activities, and special projects for the calendar year 1997. The purpose of this documents is to give a brief overview of the site and its activities, to summarize the site environmental report and the impact of 1997 SRS operations on the environment and the public, and to provide a brief explanation of radiation and dose.The data used to compile the annual environmental report and this summary can be found in Savannah River Site Environmental Data for 1997 (WSRC-TR-97-00324)

Savannah River Waste Management Program Plan - FY 1982

International Nuclear Information System (INIS)

1981-12-01

This document provides the program plan as requested by the Savannah River Operations Office of the Department of Energy. The plan was developed to provide a working knowledge of the nature and extent of the waste management programs being undertaken by Savannah River (SR) contractors for the Fiscal Year 1982. In addition, the document projects activities for several years beyond 1982 to adequately plan for safe handling and storage of radioactive wastes generated at Savannah River, for developing technology to immobilize high-level radioactive wastes generated and stored at SR, and for developing technology for improved management of low-level solid wastes. A revised plan will be issued prior to the beginning of the first quarter of each fiscal year. In this document, work descriptions and milestone schedules are current as of the date of publication. Budgets are based on available information as of October 1, 1981

Pyrite nanoparticles as a Fenton-like reagent for in situ remediation of organic pollutants

Directory of Open Access Journals (Sweden)

Carolina Gil-Lozano

2014-06-01

Full Text Available The Fenton reaction is the most widely used advanced oxidation process (AOP for wastewater treatment. This study reports on the use of pyrite nanoparticles and microparticles as Fenton reagents for the oxidative degradation of copper phthalocyanine (CuPc as a representative contaminant. Upon oxidative dissolution in water, pyrite (FeS2 particles can generate H2O2 at their surface while simultaneously promoting recycling of Fe3+ into Fe2+ and vice versa. Pyrite nanoparticles were synthesized by the hot injection method. The use of a high concentration of precursors gave individual nanoparticles (diameter: 20 nm with broader crystallinity at the outer interfaces, providing a greater number of surface defects, which is advantageous for generating H2O2. Batch reactions were run to monitor the kinetics of CuPc degradation in real time and the amount of H2O2. A markedly greater degradation of CuPc was achieved with nanoparticles as compared to microparticles: at low loadings (0.08 mg/L and 20 h reaction time, the former enabled 60% CuPc removal, whereas the latter enabled only 7% removal. These results confirm that the use of low concentrations of synthetic nanoparticles can be a cost effective alternative to conventional Fenton procedures for use in wastewater treatment, avoiding the potential risks caused by the release of heavy metals upon dissolution of natural pyrites.

Investigating the formation of acid mine drainage of Toledo pyrite concentrate using column cells

Science.gov (United States)

Aguila, Diosa Marie

2018-01-01

Acid mine drainage (AMD) is an inevitable problem in mining and has adverse effects in water quality. Studying AMD formation will be valuable in controlling the composition of mine waters and in planning the rehabilitation method for a mine. In this research, kinetics of AMD formation of Toledo pyrite was studied using two column experiments. The mechanisms of AMD formation and the effects of various factors on pH drop were first studied. Another column test was done for validation and to study the role of Fe2+/Fe3+ ratio in the change of leachate pH. The first experiment revealed that time and particle size are the most significant factors. It was also observed that the sudden pH drop during the starting hours was due to cracks formed from beneficiation, and the formation of Fe(OH)3. The laddered behavior of pH thereafter was due to decrease in formation of Fe(OH)3, and the precipitates in pyrite surface that lowered the surface area available for pyrite oxidation. The results of the second experiment validated the laddered behavior of pH. It was also observed that particle size distribution and pyrite surface were affected by the change in pH. Fe2+/Fe3+ ratio of leachate generally decreased as pH dropped.

A History of the Savannah District U.S. Army Corps of Engineers

Science.gov (United States)

1989-01-01

Moultrie, GA Moultrie Municipal Airport, Moultrie, GA Tifton Army Airfield, Tifton , GA Turner Field and Auxiliary Fields, Albany, GA Albany Municipal...Avenue,Savannah, GA ,31401 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM...Civil War, Gilmer moved to Savannah, Georgia, and from 1867 until his death in 1883, he was president of the Savannah Gas Light Company. His grave

Westinghouse independent safety review of Savannah River production reactors

International Nuclear Information System (INIS)

Leggett, W.D.; McShane, W.J.; Liparulo, N.J.; McAdoo, J.D.; Strawbridge, L.E.; Call, D.W.

1989-01-01

Westinghouse Electric Corporation has performed a safety assessment of the Savannah River production reactors (K, L, and P) as requested by the US Department of Energy. This assessment was performed between November 1, 1988, and April 1, 1989, under the transition contract for the Westinghouse Savannah River Company's preparations to succeed E.I. du Pont de Nemours ampersand Company as the US Department of Energy contractor for the Savannah River Project. The reviewers were drawn from several Westinghouse nuclear energy organizations, embody a combination of commercial and government reactor experience, and have backgrounds covering the range of technologies relevant to assessing nuclear safety. The report presents the rationale from which the overall judgment was drawn and the basis for the committee's opinion on the phased restart strategy proposed by E.I. du Pont de Nemours ampersand Company, Westinghouse, and the US Department of Energy-Savannah River. The committee concluded that it could recommend restart of one reactor at partial power upon completion of a list of recommended upgrades both to systems and their supporting analyses and after demonstration that the organization had assimilated the massive changes it will have undergone. 37 refs., 1 fig., 3 tabs

Westinghouse independent safety review of Savannah River production reactors

Energy Technology Data Exchange (ETDEWEB)

Leggett, W.D.; McShane, W.J. (Westinghouse Hanford Co., Richland, WA (USA)); Liparulo, N.J.; McAdoo, J.D.; Strawbridge, L.E. (Westinghouse Electric Corp., Pittsburgh, PA (USA). Nuclear and Advanced Technology Div.); Toto, G. (Westinghouse Electric Corp., Pittsburgh, PA (USA). Nuclear Services Div.); Fauske, H.K. (Fauske and Associates, Inc., Burr Ridge, IL (USA)); Call, D.W. (Westinghouse Savannah R

1989-04-01

Westinghouse Electric Corporation has performed a safety assessment of the Savannah River production reactors (K,L, and P) as requested by the US Department of Energy. This assessment was performed between November 1, 1988, and April 1, 1989, under the transition contract for the Westinghouse Savannah River Company's preparations to succeed E.I. du Pont de Nemours Company as the US Department of Energy contractor for the Savannah River Project. The reviewers were drawn from several Westinghouse nuclear energy organizations, embody a combination of commercial and government reactor experience, and have backgrounds covering the range of technologies relevant to assessing nuclear safety. The report presents the rationale from which the overall judgment was drawn and the basis for the committee's opinion on the phased restart strategy proposed by E.I. du Pont de Nemours Company, Westinghouse, and the US Department of Energy-Savannah River. The committee concluded that it could recommend restart of one reactor at partial power upon completion of a list of recommended upgrades both to systems and their supporting analyses and after demonstration that the organization had assimilated the massive changes it will have undergone.

Geomorphology and geologic characteristics of the Savannah River floodplain in the vicinity of the Savannah River Site, South Carolina and Georgia

International Nuclear Information System (INIS)

Leeth, D.C.; Nagle, D.D.

1994-01-01

The potential for migration of contaminated ground water from the US Department of Energy Savannah River Site (SRS) beneath the Savannah River into Georgia (trans-river flow) is a subject of recent environmental concern. The degree of incision of the ancestral Savannah River into the local hydrogeologic framework is a significant consideration in the assessment of trans-river flow. The objective of this investigation is to identify the geologic formations which subcrop beneath the alluvium and the extent to which the river has incised regional confining beds. To meet this objective 18 boreholes were drilled to depths of 25 to 100 feet along three transects across the present floodplain. These borings provided data on the hydrogeologic character of the strata that fill the alluvial valley. The profiles from the borehole transects were compared with electrical conductivity (EM-34) data to ascertain the applicability of this geophysical technique to future investigations

Radioactive effluents in the Savannah River: Summary report for 1989

International Nuclear Information System (INIS)

Winn, W.G.

1991-09-01

Researchers at the Savannah River Site have low-level radiometric studies of the Savannah River to distinguish between the effluent contributions of the Savannah River Site and Plant Vogtle. Since the startup of Plant Vogtle in 1987, researchers have routinely detected neutron-activated isotopes in controlled releases, but all have routinely detected neutron-activated isotopes in controlled releases, but all have been well below the Department of Energy's (DOE) guidelines. The study has found that processing improvement at Plant Vogtle during 1989 have lowered the activities of effluents from Plant Vogtle. These studies will continue on a routine basis because they provide disturbing trends before actual health concerns evolve

Bioleaching of low grade uranium ore containing pyrite using A. ferrooxidans and A. thiooxidans

International Nuclear Information System (INIS)

Alexey Borisovich Umanskii; Anton Mihaylovich Klyushnikov

2013-01-01

A process of uranium extraction from ore containing 3.1 % pyrite by bacterial leaching was investigated in shaken flasks during 90 days. The highest uranium recovery amounting to 85.1 % was obtained using binary mixture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans that was exceeding results obtained by traditional acid leaching technique up to 27 %. High uranium recovery was founded to be due to the high degree of pyrite dissolution that can be readily achieved by bacterial leaching (up to 98.0 %). (author)

Acid-base properties of a limed pyritic overburden during simulated weathering

Energy Technology Data Exchange (ETDEWEB)

Doolittle, J.J.; Hossner, L.R. [South Dakota State University, Brookings, SD (United States). Plant Science Dept.

1997-11-01

Surface-mine reclamation is often hindered by the formation of acid mine soil and acid mine drainage from FeS{sub 2} oxidation. Surface soils containing FeS{sub 2} are often treated with crushed limestone (predominately CaCO{sub 3}) to prevent aid minesoil formation. The main objective of this study was to evaluate the long-term effectiveness of liming pyritic minesoil to prevent the formation of acid minesoil and acid mine drainage. Pyritic minesoils that did not receive lime became acidic very rapidly and produced acidic leachate. Almost all of the FeS{sub 2} in this treatment oxidized during the first 200 d. The addition of lime at a rate of 25% of the theoretical acid-base account (ABA) significantly slowed FeS{sub 2} oxidation, but rapid oxidation ensued after the added lime was neutralized. Treatments receiving a liming rate of 50% ABA or greater remained neutral to alkaline throughout the study. Acid-base values and residual FeS{sub 2}-CO{sub 3} data, however, indicate that the lime was dissolving from the system faster than the FeS{sub 2} was oxidizing, and all the treatments would eventually become acidic. The results indicate that the liming of a pyritic overburden to an ABA of 125% is not a sustainable solution to preventing acid minesoil and acid mine drainage. 25 refs., 6 figs., 3 tabs.

Remote sensing analysis of thermal plumes at the Savannah River Plant

International Nuclear Information System (INIS)

Doak, E.L.

1985-01-01

The nuclear reactors of the Savannah River Plant (SRP) in Aiken, South Carolina, use cold water diverted from the Savannah River to dissipate unused thermal energy. This water is heated by heat exchangers of the reactors during the materials production process, and then returned to the natural drainage system. Thermal effluents were monitored by an airborne thermal infrared scanner during predawn overlights. Images were generated to show the surface temperature distribution of the thermal outfall plumes into the Savannah River. The thermal analysis provides information related to compliance with permit requirements of the regulatory agencies

Terrestrial sedimentary pyrites as a potential source of trace metal release to groundwater – A case study from the Emsland, Germany

International Nuclear Information System (INIS)

Houben, Georg J.; Sitnikova, Maria A.; Post, Vincent E.A.

2017-01-01

Pyrite is a common minor constituent of terrestrial freshwater sediments and a sink for trace elements. Different amounts and morphological types (framboids and euhedral crystals) of sedimentary pyrites were found in the heavy mineral fraction of cores obtained from several drillholes located in the Emsland region, NW Germany. Their trace element contents were investigated to assess their potential for groundwater contamination after oxidation, e.g. induced by dewatering or autotrophic denitrification. Nickel, arsenic and cadmium were found in significant concentrations in pyrite. Geochemical modeling showed that elevated trace metal concentrations in groundwater, potentially exceeding drinking water standards, should preferentially occur in a less than 1 m thick zone situated around the depth of the redoxcline, where nitrate is reduced by pyrite. This was confirmed by depth-specific groundwater sampling in the Emsland and by previously published studies. The absolute concentration of released trace metals depends on their content in the pyrite but also strongly on the nitrate load of groundwater. - Highlights: • Pyrite from heavy mineral fraction of aquifer sediment analyzed for trace metal content. • Pyrites contain significant concentration of trace metals, such as nickel, arsenic, cadmium. • Trace elements are released by autotrophic denitrification. • Reactive transport model predicts small zone of trace element accumulation. • Release of trace elements strongly dependent on nitrate content of groundwater.

Correlation of Surface Adsorption and Oxidation with a Floatability Difference of Galena and Pyrite in High-Alkaline Lime Systems.

Science.gov (United States)

Niu, Xiaopeng; Ruan, Renman; Xia, Liuyin; Li, Li; Sun, Heyun; Jia, Yan; Tan, Qiaoyi

2018-02-27

When it comes to Pb-Zn ores with high amounts of pyrite, the major problem encountered is the low separation efficiency between galena and pyrite. By virtue of high dosage of lime and collector sodium diethyl dithiocarbamate (DDTC), pyrite and zinc minerals are depressed, allowing the galena to be floated. However, there have been significant conflicting reports on the flotation behavior of galena at high pH. In this context, correlation of the surface adsorption and oxidation with the floatability difference of galena and pyrite in high-alkaline lime systems would be a key issue for process optimization. Captive bubble contact angle measurements were performed on freshly polished mineral surfaces in situ exposed to lime solutions of varying pH as a function of immersion time. Furthermore, single mineral microflotation tests were conducted. Both tests indicated that the degree of hydrophobicity on the surfaces of galena and pyrite increased in the presence of DDTC at natural or mild pulp pH. While in a saturated lime solution, at pH 12.5, DDTC only worked for galena, but not for pyrite. Surface chemistry analysis by time-of-flight secondary ion mass spectrometry (Tof-SIMS) confirmed the preference of DDTC on the galena surface at pH 12.5, which contributed to a merit recovery. Further important evidence through measurements of Tof-SIMS, ion chromatography, and high-performance liquid chromatography indicated that in high-alkaline lime systems, the merit floatability of galena could exclude the insignificant contribution of elemental sulfur (S 8 ) and was dominantly attributed by the strong adsorption of DDTC. In contrast, the poor flotation response of pyrite at high pH was due to the prevailing adsorption of CaOH + species. This study provides an important surface chemistry evidence for a better understanding of the mechanism on the better selectivity in the galena-pyrite separation adopting high-alkaline lime systems.

Surface chemistry of pyrite during the pre-processing for the flotation in alkaline sodium carbonate medium during uranium ore processing

International Nuclear Information System (INIS)

Neudert, A.; Sommer, H.; Schubert, H.

1991-01-01

It is often necessary during processing of uranium ore to flotate pyrite at sodium carbonate alkaline pH value caused by the subsequent hydrometallurgical process stages. It was found out by ESCA analyses that the pyrite surface changes chemically prior to the addition of flotation agents. FeS 2 becomes FeO within a few hours in the case of storage in process water; limonite and/or geothite result from pyrite. The copper ions of the activator CuSO 4 are exclusively monovalent on the pyrite surface. The resulting heavy metal xanthogenate is Cu(I) xanthogenate. Conclusions are derived for the flotation practice for the intensification of the reagent regime. (orig./HP) [de

Savannah River Interim Waste Management Program Plan - FY 1986

International Nuclear Information System (INIS)

1985-09-01

This document provides the program plan as requested by the Savannah River Operations Office of the Department of Energy. The plan was developed to provide a working knowledge of the nature and extent of the interim waste management programs being undertaken by Savannah River (SR) contractors for the Fiscal Year 1986. In addition, the document projects activities for several years beyond 1986 to adequately plan for safe handling and storage of radioactive wastes generated at Savannah River and for developing technology for improved management of low-level solid wastes. A revised plan will be issued prior to the beginning of the first quarter of each fiscal year. In this document, work descriptions and milestone schedules are current as of the date of publication. Budgets are based on available information as of May 1985

Savannah River Interim Waste Management Program plan, FY-1987

International Nuclear Information System (INIS)

1986-09-01

This document provides the program plan as requested by the Savannah River Operations office of the Department of Energy. The plan was developed to provide a working knowledge of the nature and extent of the interim waste management programs being undertaken by Savannah River (SR) contractors for the Fiscal Year 1987. In addition, the document projects activities for several years beyond 1987 to adequately plan for safe handling and storage of radioactive wastes generated at Savannah River and for developing technology for improved management of low-level solid wastes. A revised plan will be issued prior to the beginning of the first quarter of each fiscal year. In this document, work descriptions and milestone schedules are current as of the date of publication. Budgets are based on available information as of June 1986

Smectite-zeolite envelope surrounding the Tsukiyoshi uranium deposit, central Japan. A natural analogue study

International Nuclear Information System (INIS)

Utada, Minoru

2003-01-01

The Tsukiyoshi uranium deposit in Gifu Prefecture is the largest one in Japan. It is embedded in lower part of the Mizunami Group of Miocene age. Relating to the existence of this uranium deposit, the constituent minerals in sediments were studied by XRD and SEM, using many drilling cores. The most abundant authigenic mineral is smectite. The amount of smectite increases generally from upper to lower horizons, and a highly smectitized zone is situated around the uranium deposit. Smectitization predominated in mafic glassy grains of sediments, which was probably formed in early burial diagenesis. Zeolites including clinoptilolite-heulandite, mordenite, analcime, chabazite and philipsite are secondly abundant authigenic minerals. They seem to have been formed at early to late diagenetic stages. Opaline silica is rather rare. Carbonate minerals, including calcite, dolomite, siderite and rhodocrosite are common. They may be formed by diagenesis as well. Gypsum and pyrite occur in upper horizons and lower horizons, respectively. In particular, a highly smectitized zone including pyrite probably played an important role for retarding the migration of uranium and as a result keeping the uranium deposit for past one million years. This smectite-zeolite envelope surrounding the Tsukiyoshi uranium deposit is regarded as a natural analogue of the buffer materials surrounding the high-level radioactive waste repository. (author)

Effects of heat-flow and hydrothermal fluids from volcanic intrusions on authigenic mineralization in sandstone formations

Directory of Open Access Journals (Sweden)

Wolela Ahmed

2002-06-01

Full Text Available Volcanic intrusions and hydrothermal activity have modified the diagenetic minerals. In the Ulster Basin, UK, most of the authigenic mineralization in the Permo-Triassic sandstones pre-dated tertiary volcanic intrusions. The hydrothermal fluids and heat-flow from the volcanic intrusions did not affect quartz and feldspar overgrowths. However, clay mineral-transformation, illite-smectite to illite and chlorite was documented near the volcanic intrusions. Abundant actinolite, illite, chlorite, albite and laumontite cementation of the sand grains were also documented near the volcanic intrusions. The abundance of these cementing minerals decreases away from the volcanic intrusions.In the Hartford Basin, USA, the emplacement of the volcanic intrusions took place simultaneous with sedimentation. The heat-flow from the volcanic intrusions and hydrothermal activity related to the volcanics modified the texture of authigenic minerals. Microcrystalline mosaic albite and quartz developed rather than overgrowths and crystals near the intrusions. Chlorite clumps and masses were also documented with microcrystalline mosaic albite and quartz. These features are localized near the basaltic intrusions. Laumontite is also documented near the volcanic intrusions. The reservoir characteristics of the studied sandstone formations are highly affected by the volcanic and hydrothermal fluids in the Hartford and the Ulster Basin. The porosity dropped from 27.4 to zero percent and permeability from 1350 mD to 1 mD.

The origin of copiapite from chlorite pyritic schist (Wiesciszowice, Lower Silesia, Poland) in the light of Moessbauer analysis

Energy Technology Data Exchange (ETDEWEB)

Adamczyk, Z., E-mail: zdzislaw.adamczyk@polsl.pl [Silesian University of Technology, Institute of Applied Geology (Poland); Komraus, J. L., E-mail: komraus@us.edu.pl [University of Silesia, Institute of Physics (Poland)

2008-01-15

This work presents the results of the analysis of copiapite, formed from weathering and oxidation of pyrite in pyritic schist from Wiesciszowice, Lower Silesia (Poland). The pure phase of copiapite was found in secondary minerals after pyrite and identified by optical microscopy, XRD and Moessbauer spectroscopy. In the analyzed copiapite major cations appear to be Fe{sup 2+} and Fe{sup 3+}. Some Fe{sup 3+} is substituted by other cations, mainly Al{sup 3+}. Al{sup 3+} probably comes from leaching of chlorite from which hydrated sulphates of iron, mainly szomolnokite, form followed by hydrated sulphates fibroferrite, which is replaced by copiapite.

Authigenic Gypsum in Gas-Hydrate Associated Sediments from the East Coast of India (Bay of Bengal)

Digital Repository Service at National Institute of Oceanography (India)

Kocherla, M.

operation respectively. This is NIO contribution no… 10 4.0 References. Aharon, P., Graber, E. R. Roberts, H. H., 1992. Dissolved carbon and delta c-13 anomalies in the water column caused by hydrocarbon seeps on the northwestern Gulf of Mexico... hydrate. Geology, 24: 655–658. Botz, R., Faber, E., Whiticar, M, Brooks, J.M., 1988. Authigenic carbonates in sediments from the Gulf of Mexico. Earth and Planetary Science Letters, 88: 263-272. Bohrmann, G., Greinert, J., Suess, E., Torres, M., 1998...

In situ remediation of hexavalent chromium with pyrite fines : bench scale demonstration

International Nuclear Information System (INIS)

Cathum, S.; Wong, W.P.; Brown, C.E.

2002-01-01

An in situ remediation technique for chromium contaminated soil with pyrite fines was presented. Past industrial activities and lack of disposal facilities have contributed to a serious problem dealing with chromium, which cannot be eliminated from the environment because it is an element. Both bench-scale and laboratory testing was conducted to confirm the efficiency of the proposed process which successfully converted Cr(VI) into Cr(III) in soil and water. Cr(III) is less toxic and immobile in the environment compared to Cr(VI) which moves freely in the soil matrix, posing a risk to the groundwater quality. pH in the range of 2.0 to 7.6 has no effect on the reactivity of pyrite towards Cr(VI). The optimization of the bench-scale treatment resulted in a large volume of chromium waste, mostly from the control experiments and column hydrology testing. These waste streams were treated according to municipal guidelines before disposal to the environment. Samples of chromium waste before and after treatment were analyzed. Cr (VI) was completely mineralized to below guideline levels. It was determined that several conditions, including contact time between pyrite and Cr(VI), are crucial for complete mineralization of Cr(VI). 13 refs., 8 tabs., 9 figs

Meteoric water in normal fault systems: Oxygen and hydrogen isotopic measurements on authigenic phases in brittle fault rocks

Science.gov (United States)

Haines, S. H.; Anderson, R.; Mulch, A.; Solum, J. G.; Valley, J. W.; van der Pluijm, B. A.

2009-12-01

The nature of fluid circulation systems in normal fault systems is fundamental to understanding the nature of fluid movement within the upper crust, and has important implications for the on-going controversy about the strength of faults. Authigenic phases in clay gouges and fault breccias record the isotopic signature of the fluids they formed in equilibrium with, and can be used to understand the ‘plumbing system’ of brittle fault environments. We obtained paired oxygen and hydrogen isotopic measurements on authigenic illite and/or smectite in clay gouge from normal faults in two geologic environments, 1.) low-angle normal faults (Ruby Mountains detachment, NV; Badwater Turtleback, CA; Panamint range-front detachment; CA; Amargosa detachment; CA; Waterman Hills detachment, CA), and 2.) An intracratonic high-angle normal fault (Moab Fault, UT). All authigenic phases in these clay gouges are moderately light isotopically with respect to oxygen (illite δ18O -2.0 - + 11.5 ‰ SMOW, smectite δ18O +3.6 and 17.9 ‰) and very light isotopically with respect to hydrogen (illite δD -148 to -98 ‰ SMOW, smectite δD -147 to -92 ‰). Fluid compositions calculated from the authigenic clays at temperatures of 50 - 130 ○C (as indicated by clay mineralogy) indicate that both illite and smectite in normal fault clay gouge formed in the presence of near-pristine to moderately-evolved meteoric fluids and that igneous or metamorphic fluids are not involved in clay gouge formation in these normal fault settings. We also obtained paired oxygen and hydrogen isotopic measurements on chlorites derived from footwall chlorite breccias in 4 low-angle normal fault detachment systems (Badwater and Mormon Point Turtlebacks, CA, the Chemehuevi detachment, CA, and the Buckskin-Rawhide detachment, AZ). All chlorites are isotopically light to moderately light with respect to oxygen (δ18O +0.29 to +8.1 ‰ SMOW) and very light with respect to hydrogen (δD -97 to -113 ‰) and indicate

Savannah River Site Environmental Report for 1990: Summary pamphlet

International Nuclear Information System (INIS)

Cummings, C.L.; Martin, D.K.; Todd, J.L.

1991-01-01

The SRS publishes the Environmental Report each year to communicate the endings of the environmental monitoring and research programs to the public and government agencies. This pamphlet is intended to summarize important environmental activities at the Savannah River Site in 1990. Highlights include: In 1990, over 40,000 samples of environmental material were collected for radiological and nonradiological analyses. The largest radiation doses to the surrounding population were from the radionuclide ''tritium,'' which was released to air and water from SRS operations.; tritium concentrations measured near the site in air, rainwater, Savannah River water, milk from local dairies and downriver drinking water were higher than background levels; the maximum radiation dose to individuals offsite was estimated to be 0.16 millirem from atmospheric releases of radioactivity, and 0.17 millirem from liquid releases of radioactivity. There was one accidental release of tritium to air on February 7, when 100 curies were released from a K-Area stack. The maximum radiation dose offsite was calculated to be 0.003 millirem (mrem); SRS issued a detailed report on the impact of routine and accidental releases of tritium from 1964 to 1988 on the environment. Currently, SRS investigating possible causes for higher concentrations of mercury found in fish caught onsite, compared to those taken from the Savannah River. Mercury concentrations have been higher in onsite fish since 1989; and, n response to concerns expressed by the Georgia Department of Natural Resources (GDNR) over concentrations of radionuclides in fish collected from the Savannah River, the Savannah River Site is working with the GDNR to resolve technical issues regarding sampling and analyses of fish from the river and the resultant dose calculations

Radioiodine in the Savannah River Site environment

Energy Technology Data Exchange (ETDEWEB)

Kantelo, M.V.; Bauer, L.R.; Marter, W.L.; Murphy, C.E. Jr.; Zeigler, C.C.

1993-01-15

Radioiodine, which is the collective term for all radioactive isotopes of the element iodine, is formed at the Savannah River Site (SRS) principally as a by-product of nuclear reactor operations. Part of the radioiodine is released to the environment during reactor and reprocessing operations at the site. The purpose of this report is to provide an introduction to radioiodine production and disposition, its status in the environment, and the radiation dose and health risks as a consequence of its release to the environment around the Savannah River Plant. A rigorous dose reconstruction study is to be completed by thee Center for Disease Control during the 1990s.

Radioiodine in the Savannah River Site environment

International Nuclear Information System (INIS)

Kantelo, M.V.; Bauer, L.R.; Marter, W.L.; Murphy, C.E. Jr.; Zeigler, C.C.

1993-01-01

Radioiodine, which is the collective term for all radioactive isotopes of the element iodine, is formed at the Savannah River Site (SRS) principally as a by-product of nuclear reactor operations. Part of the radioiodine is released to the environment during reactor and reprocessing operations at the site. The purpose of this report is to provide an introduction to radioiodine production and disposition, its status in the environment, and the radiation dose and health risks as a consequence of its release to the environment around the Savannah River Plant. A rigorous dose reconstruction study is to be completed by thee Center for Disease Control during the 1990s

Restart of K-Reactor, Savannah River Site: Safety evaluation report

Energy Technology Data Exchange (ETDEWEB)

1991-04-01

This Safety Evaluation Report (SER) focuses on those issues required to support the restart of the K-Reactor at the Savannah River Plant. This SER provides the safety criteria for restart and documents the results of the staff reviews of the DOE and operating contractor activities to meet these criteria. To develop the restart criteria for the issues discussed in this SER, the Savannah River Restart Office and Savannah River Special Projects Office staffs relied, when possible, on commercial industry codes and standards and on NRC requirements and guidelines for the commercial nuclear industry. However, because of the age and uniqueness of the Savannah River reactors, criteria for the commercial plants were not always applicable. In these cases, alternate criteria were developed. The restart criteria applicable to each of the issues are identified in the safety evaluations for each issue. The restart criteria identified in this report are intended to apply only to restart of the Savannah River reactors. Following the development of the acceptance criteria, the DOE staff and their support contractors evaluated the results of the DOE and operating contractor (WSRC) activities to meet these criteria. The results of those evaluations are documented in this report. Deviations or failures to meet the requirements are either justified in the report or carried as open or confirmatory items to be completed and evaluated in supplements to this report before restart. 62 refs., 1 fig.

Restart of K-Reactor, Savannah River Site: Safety evaluation report

International Nuclear Information System (INIS)

1991-04-01

This Safety Evaluation Report (SER) focuses on those issues required to support the restart of the K-Reactor at the Savannah River Plant. This SER provides the safety criteria for restart and documents the results of the staff reviews of the DOE and operating contractor activities to meet these criteria. To develop the restart criteria for the issues discussed in this SER, the Savannah River Restart Office and Savannah River Special Projects Office staffs relied, when possible, on commercial industry codes and standards and on NRC requirements and guidelines for the commercial nuclear industry. However, because of the age and uniqueness of the Savannah River reactors, criteria for the commercial plants were not always applicable. In these cases, alternate criteria were developed. The restart criteria applicable to each of the issues are identified in the safety evaluations for each issue. The restart criteria identified in this report are intended to apply only to restart of the Savannah River reactors. Following the development of the acceptance criteria, the DOE staff and their support contractors evaluated the results of the DOE and operating contractor (WSRC) activities to meet these criteria. The results of those evaluations are documented in this report. Deviations or failures to meet the requirements are either justified in the report or carried as open or confirmatory items to be completed and evaluated in supplements to this report before restart. 62 refs., 1 fig

Solidification of Savannah River Plant high-level waste

International Nuclear Information System (INIS)

Maher, R.; Shafranek, L.F.; Stevens, W.R. III.

1983-01-01

The Department of Energy, in accord with recommendations from the Du Pont Company, has started construction of a Defense Waste Processing Facility (DWPF) at the Savannah River Plant. The facility should be completed by the end of 1988, and full-scale operation should begin in 1990. This facility will immobilize in borosilicate glass the large quantity of high-level radioactive waste now stored at the plant plus the waste to be generated from continued chemical reprocessing operations. The existing wastes at the Savannah River Plant will be completely converted by about 2010. 21 figures

Savannah River Laboratory's operating experience with glass melters

International Nuclear Information System (INIS)

Brown, F.H.; Randall, C.T.; Cosper, M.B.; Moseley, J.P.

1982-01-01

The Department of Energy, with recommendations from the Du Pont Company, is proposing that a Defense Waste Processing Facility be constructed at the Savannah River Plant to immobilize radioactive The immobilization process is designed around the solidification of waste sludge in borosilicate glass. The Savannah River Laboratory, who is responsible for the solidification process development program, has completed an experimental program with one large-scale glass melter and just started up another melter. Experimental data indicate that process requirements can easily be met with the current design. 7 figures

Influence of Sulfobacillus thermosulfidooxidans on Initial Attachment and Pyrite Leaching by Thermoacidophilic Archaeon Acidianus sp. DSM 29099

Directory of Open Access Journals (Sweden)

Jing Liu

2016-07-01

Full Text Available At the industrial scale, bioleaching of metal sulfides includes two main technologies, tank leaching and heap leaching. Fluctuations in temperature caused by the exothermic reactions in a heap have a pronounced effect on the growth of microbes and composition of mixed microbial populations. Currently, little is known on the influence of pre-colonized mesophiles or moderate thermophiles on the attachment and bioleaching efficiency by thermophiles. The objective of this study was to investigate the interspecies interactions of the moderate thermophile Sulfobacillus thermosulfidooxidans DSM 9293T and the thermophile Acidianus sp. DSM 29099 during initial attachment to and dissolution of pyrite. Our results showed that: (1 Acidianus sp. DSM 29099 interacted with S. thermosulfidooxidansT during initial attachment in mixed cultures. In particular, cell attachment was improved in mixed cultures compared to pure cultures alone; however, no improvement of pyrite leaching in mixed cultures compared with pure cultures was observed; (2 active or inactivated cells of S. thermosulfidooxidansT on pyrite inhibited or showed no influence on the initial attachment of Acidianus sp. DSM 29099, respectively, but both promoted its leaching efficiency; (3 S. thermosulfidooxidansT exudates did not enhance the initial attachment of Acidianus sp. DSM 29099 to pyrite, but greatly facilitated its pyrite dissolution efficiency. Our study provides insights into cell-cell interactions between moderate thermophiles and thermophiles and is helpful for understanding of the microbial interactions in a heap leaching environment.

Matrix composition and community structure analysis of a novel bacterial pyrite leaching community.

Science.gov (United States)

Ziegler, Sibylle; Ackermann, Sonia; Majzlan, Juraj; Gescher, Johannes

2009-09-01

Here we describe a novel bacterial community that is embedded in a matrix of carbohydrates and bio/geochemical products of pyrite (FeS(2)) oxidation. This community grows in stalactite-like structures--snottites--on the ceiling of an abandoned pyrite mine at pH values of 2.2-2.6. The aqueous phase in the matrix contains 200 mM of sulfate and total iron concentrations of 60 mM. Micro-X-ray diffraction analysis showed that jarosite [(K,Na,H(3)O)Fe(3)(SO(4))(2)(OH)(6)] is the major mineral embedded in the snottites. X-ray absorption near-edge structure experiments revealed three different sulfur species. The major signal can be ascribed to sulfate, and the other two features may correspond to thiols and sulfoxides. Arabinose was detected as the major sugar component in the extracellular polymeric substance. Via restriction fragment length polymorphism analysis, a community was found that mainly consists of iron oxidizing Leptospirillum and Ferrovum species but also of bacteria that could be involved in dissimilatory sulfate and dissimilatory iron reduction. Each snottite can be regarded as a complex, self-contained consortium of bacterial species fuelled by the decomposition of pyrite.

Whole rock and discrete pyrite geochemistry as complementary tracers of ancient ocean chemistry: An example from the Neoproterozoic Doushantuo Formation, China

Science.gov (United States)

Gregory, Daniel D.; Lyons, Timothy W.; Large, Ross R.; Jiang, Ganqing; Stepanov, Aleksandr S.; Diamond, Charles W.; Figueroa, Maria C.; Olin, Paul

2017-11-01

The trace element content of pyrite is a recently developed proxy for metal abundance in paleo-oceans. Previous studies have shown that the results broadly match those of whole rock studies through geologic time. However, no detailed study has evaluated the more traditional proxies for ocean chemistry for comparison to pyrite trace element data from the same samples. In this study we compare pyrite trace element data from 14 samples from the Wuhe section of the Ediacaran-age Doushantuo Formation, south China, measured by laser ablation inductively coupled plasma mass spectrometry with new and existing whole rock trace element concentrations; total organic carbon; Fe mineral speciation; S isotope ratios; and pyrite textural relationships. This approach allows for comparison of data for individual trace elements within the broader environmental context defined by the other chemical parameters. The results for discrete pyrite analyses show that several chalcophile and siderophile elements (Ag, Sb, Se, Pb, Cd, Te, Bi, Mo, Ni, and Au) vary among the samples with patterns that mirror those of the independent whole rock data. A comparison with existing databases for sedimentary and hydrothermal pyrite allows us to discriminate between signatures of changing ocean conditions and those of known hydrothermal sources. In the case of the Wuhe samples, the observed patterns for trace element variation point to primary marine controls rather than higher temperature processes. Specifically, our new data are consistent with previous arguments for pulses of redox sensitive trace elements interpreted to be due to marine oxygenation against a backdrop of mostly O2-poor conditions in the Ediacaran ocean-with important implications for the availability of bioessential elements. The agreement between the pyrite and whole rock data supports the use of trace element content of pyrite as a tracer of ocean chemistry in ways that complement existing approaches, while also opening additional

An experimental study on the geochemical behavior of highly siderophile elements (HSE) and metalloids (As, Se, Sb, Te, Bi) in a mss-iss-pyrite system at 650 °C: A possible magmatic origin for Co-HSE-bearing pyrite and the role of metalloid-rich phases in the fractionation of HSE

Science.gov (United States)

Cafagna, Fabio; Jugo, Pedro J.

2016-04-01

Pyrite, the most abundant sulfide in the Earth's crust, is an accessory mineral in several magmatic sulfide deposits. Although most pyrite is hydrothermal, previous experimental studies have shown that pyrite can also have a primary magmatic origin, by exsolving from monosulfide solid solution (mss) during cooling of a sulfide melt, if sulfur fugacity is sufficiently high. Pyrite from some localities has significant amounts of Co, and complex zonation in some low-melting-point chalcophile elements (LMCE), such as As, Se, Sb, Te, Bi (henceforth referred to as metalloids) and some platinum-group elements (PGE: Ru, Rh, Pd, Os, Ir, Pt). However, the origin of such pyrite and the causes of zonation are not clear. Because the distribution of some of these elements is heterogeneous and seems to be developed in concentric zones, the zonation has been interpreted to represent growth stages, some of them secondary and caused partly by hydrothermal fluids. Better constraints on the origin of Co-PGE-bearing pyrite could help unravel the geochemical processes affecting the sulfide assemblages in which it is found; thus, an experimental study was undertaken to characterize pyrite formation in magmatic sulfide environments and its relationship with metalloids and highly siderophile elements (HSE: PGE, Re, Au). Natural pyrrhotite, chalcopyrite, pentlandite and elemental S were mixed and doped with approximately 50 ppm of each HSE. A mixture of metalloids was added at 0.2 wt.% or 3 wt.% to aliquots of sulfide mixtures. Starting materials were sealed in evacuated silica tubes and fused at 1200 °C. The temperature was subsequently reduced to 750 °C (at 60 °C/h), then to 650 °C (at 0.5 °C/h) to produce relatively large euhedral pyrite crystals, then quenched. The experiments were analyzed using reflected light, SEM, EPMA and LA-ICP-MS. Experimental products contained euhedral pyrite, mss, intermediate solid solution (iss) and metalloid-rich phases, interpreted as quench product

Dating of authigenic clays related to igneous intrusions in Hunter Valley Coals

International Nuclear Information System (INIS)

Zwingmann, H.

2000-01-01

The Sydney Basin is composed mainly of Permian and Triassic marine and non-marine clastic sedimentary strata together with economically significant coal deposits and volumetrically minor igneous rocks. Many of these igneous rocks are also economically significant not only for their use in the construction industry but also for their deleterious effects on coal mining, particularly in underground mines utilising longwall extraction systems. Igneous activity in the Sydney Basin ranges from Early Permian to Tertiary in age and although episodic in nature, activity was unlikely to have ceased for periods of more than approximately 10 million years (Carr and Facer 1980; Embleton et al. 1982). Dating of the time of emplacement of igneous rocks using the K-Ar isotopic system is a relatively straightforward procedure if suitable analytical facilities and samples of appropriate, fresh, primary minerals are available. In the case of intrusions in coal seams, however, the occurrence of fresh, primary minerals is very rare due to widespread alteration produced by interaction between the igneous rock and fluids in the coal seam. This interaction produces a variety of secondary minerals with most primary minerals and glass being altered to clays (mainly kaolinite) and carbonates. Consequently, relatively few isotopic dates for intrusions into coal seams have been determined. A detailed study of several hundred samples of igneous rocks from the Sydney Basin found only six samples of intrusions into coal seams that were suitable for conventional K-Ar dating (Carr and Facer 1980). Techniques for K-Ar dating of authigenic illite, developed in response to the need by the petroleum industry to understand the timing of diagenesis in petroleum source-rocks and reservoirs, are now well established (Clauer and Chaudhuri 1995). As part of a larger project on the impact of igneous intrusions on coal mining and the alienation of coal reserves, a preliminary investigation of the timing of

Westinghouse Savannah River Site Supplier Environmental Restoration and Waste Management Information Exchange Forum

International Nuclear Information System (INIS)

Sturm, H.F. Jr.; Hottel, R.E.; Christoper, N.

1994-01-01

The Savannah River Site conducted its first Supplier Information Exchange in September 1993. The intent of the conference was to inform potential suppliers of the Savannah River Sites mission and research and development program objectives in the areas of environmental restoration and waste management, and to solicit proposals for innovative research in those areas. Major areas addressed were Solid Waste, Environmental Restoration, Environmental Monitoring, Transition/Decontamination and Decommissioning, and the Savannah River Technology Center. A total of 1062 proposals were received addressing the 89 abstracts presented. This paper will describe the forum the process for solicitation, the process for proposal review and selection, and review the overall results and benefits to Savannah River

Savannah River Site Environmental Report for 1995 Summary Pamphlet (U)

International Nuclear Information System (INIS)

Arnett, M.W.; Mamatey, A.

1995-01-01

Welcome to the Savannah River Site Environmental Report for 1995 Summary Pamphlet.Ibis pamphlet is written so you can better understand what goes on at the Savannah River Site and how it affects the environment and you personally. We hope this document also will help answer your questions on radiation and its effects. In this pamphlet we will discuss the operations at SRS, the potential impact of operations on the environment and the public, and special programs that SRS supports. This pamphlet is a summary of a detailed re- port entitled Savannah River Site Environmental Report for 1995 The report contains a summary of environmental Monitoring activities for the calendar year 1995. Additional data on groundwater are found in quarterly groundwater reports

Nuclear engineering R ampersand D at the Savannah River Site

International Nuclear Information System (INIS)

Strosnider, D.R.; Ferrara, W.R.

1991-01-01

The Westinghouse Savannah River Company (WSRC) is the prime operating contractor for the US Department of Energy at the Savannah River Site (SRS), located near Aiken, South Carolina. One division of WSRC, the Savannah River Laboratory (SRL), has the primary responsibility for research and development, which includes supporting the safe and efficient operation of the SRS production reactors. Several Sections of SRL, as well as other organization in WSRC, pursue R ampersand D and oversight activities related to nuclear engineering. The Sections listed below are described in more detail in this document: (SRL) nuclear reactor technology and scientific computations department; (SRL) safety analysis and risk management department; (WSRC) new production reactor program; and (WSRC) environment, safety, health, and quality assurance division

Cesium in the Savannah River Site environment

International Nuclear Information System (INIS)

Carlton, W.H.; Bauer, L.R.; Evans, A.G.; Geary, L.A.; Murphy, C.E. Jr.; Pinder, J.E.; Strom, R.N.

1992-03-01

Cesium in the Savannah River Site Environment is published as a part of the Radiological Assessment Program (RAP). It is the fourth in a series of eight documents on individual radioisotopes released to the environment as a result of Savannah River Site (SRS) operations. The earlier documents describe the environmental consequences of tritium, iodine, and uranium. Documents on plutonium, strontium, carbon, and technetium will be published in the future. These are dynamic documents and current plans call for revising and updating each one on a two-year schedule.Radiocesium exists in the environment as a result of above-ground nuclear weapons tests, the Chernobyl accident, the destruction of satellite Cosmos 954, small releases from reactors and reprocessing plants, and the operation of industrial, medical, and educational facilities. Radiocesium has been produced at SRS during the operation of five production reactors. Several hundred curies of 137 Cs was released into streams in the late 50s and 60s from leaking fuel elements. Smaller quantities were released from the fuel reprocessing operations. About 1400 Ci of 137 Cs was released to seepage basins where it was tightly bound by clay in the soil. A much smaller quantity, about four Ci. was released to the atmosphere. Radiocesium concentration and mechanisms for atmospheric, surface water, and groundwater have been extensively studied by Savannah River Technology Center (SRTC) and ecological mechanisms have been studied by Savannah River Ecology Laboratory (SREL). The overall radiological impact of SRS releases on the offsite maximum individual can be characterized by total doses of 033 mrem (atmospheric) and 60 mrem (liquid), compared with a dose of 12,960 mrem from non-SRS sources during the same period of time. Isotope 137 Cs releases have resulted in a negligible risk to the environment and the population it supports

Cesium in the Savannah River Site environment

Energy Technology Data Exchange (ETDEWEB)

Carlton, W.H.; Bauer, L.R.; Evans, A.G.; Geary, L.A.; Murphy, C.E. Jr.; Pinder, J.E.; Strom, R.N.

1992-03-01

Cesium in the Savannah River Site Environment is published as a part of the Radiological Assessment Program (RAP). It is the fourth in a series of eight documents on individual radioisotopes released to the environment as a result of Savannah River Site (SRS) operations. The earlier documents describe the environmental consequences of tritium, iodine, and uranium. Documents on plutonium, strontium, carbon, and technetium will be published in the future. These are dynamic documents and current plans call for revising and updating each one on a two-year schedule.Radiocesium exists in the environment as a result of above-ground nuclear weapons tests, the Chernobyl accident, the destruction of satellite Cosmos 954, small releases from reactors and reprocessing plants, and the operation of industrial, medical, and educational facilities. Radiocesium has been produced at SRS during the operation of five production reactors. Several hundred curies of [sup 137]Cs was released into streams in the late 50s and 60s from leaking fuel elements. Smaller quantities were released from the fuel reprocessing operations. About 1400 Ci of [sup 137]Cs was released to seepage basins where it was tightly bound by clay in the soil. A much smaller quantity, about four Ci. was released to the atmosphere. Radiocesium concentration and mechanisms for atmospheric, surface water, and groundwater have been extensively studied by Savannah River Technology Center (SRTC) and ecological mechanisms have been studied by Savannah River Ecology Laboratory (SREL). The overall radiological impact of SRS releases on the offsite maximum individual can be characterized by total doses of 033 mrem (atmospheric) and 60 mrem (liquid), compared with a dose of 12,960 mrem from non-SRS sources during the same period of time. Isotope [sup 137]Cs releases have resulted in a negligible risk to the environment and the population it supports.

Cesium in the Savannah River Site environment

Energy Technology Data Exchange (ETDEWEB)

Carlton, W.H.; Bauer, L.R.; Evans, A.G.; Geary, L.A.; Murphy, C.E. Jr.; Pinder, J.E.; Strom, R.N.

1992-03-01

Cesium in the Savannah River Site Environment is published as a part of the Radiological Assessment Program (RAP). It is the fourth in a series of eight documents on individual radioisotopes released to the environment as a result of Savannah River Site (SRS) operations. The earlier documents describe the environmental consequences of tritium, iodine, and uranium. Documents on plutonium, strontium, carbon, and technetium will be published in the future. These are dynamic documents and current plans call for revising and updating each one on a two-year schedule.Radiocesium exists in the environment as a result of above-ground nuclear weapons tests, the Chernobyl accident, the destruction of satellite Cosmos 954, small releases from reactors and reprocessing plants, and the operation of industrial, medical, and educational facilities. Radiocesium has been produced at SRS during the operation of five production reactors. Several hundred curies of {sup 137}Cs was released into streams in the late 50s and 60s from leaking fuel elements. Smaller quantities were released from the fuel reprocessing operations. About 1400 Ci of {sup 137}Cs was released to seepage basins where it was tightly bound by clay in the soil. A much smaller quantity, about four Ci. was released to the atmosphere. Radiocesium concentration and mechanisms for atmospheric, surface water, and groundwater have been extensively studied by Savannah River Technology Center (SRTC) and ecological mechanisms have been studied by Savannah River Ecology Laboratory (SREL). The overall radiological impact of SRS releases on the offsite maximum individual can be characterized by total doses of 033 mrem (atmospheric) and 60 mrem (liquid), compared with a dose of 12,960 mrem from non-SRS sources during the same period of time. Isotope {sup 137}Cs releases have resulted in a negligible risk to the environment and the population it supports.

Incorporation of Savannah River Plant radioactive waste into concrete

International Nuclear Information System (INIS)

Stone, J.A.

1975-01-01

Results are reported of a laboratory-scale experimental program at the Savannah River Laboratory to gain information on the fixation of high-level radioactive wastes in concrete. Two concrete formulations, a High-Alumina Cement and a Portland Pozzalanic cement, were selected on the bases of leachability and compressive strength for the fixation of non-radioactive simulated wastes. Therefore, these two cements were selected for current studies for the fixation of actual Savannah River Plant high-level wastes. (U.S.)

The transuranic waste management program at Savannah River

International Nuclear Information System (INIS)

D'Ambrosia, J.

1986-01-01

Defense transuranic waste at the Savannah River site results from the Department of Energy's national defense activities, including the operation of production reactors, fuel reprocessing plants, and research and development activities. TRU waste has been retrievably stored at the Savannah River Plant since 1974 awaiting disposal. The Waste Isolation Pilot Plant, now under construction in New Mexico, is a research and development facility for demonstrating the safe disposal of defense TRU waste, including that in storage at the Savannah River Plant. The major objective of the TRU Program at SR is to support the TRU National Program, which is dedicated to preparing waste for, and emplacing waste in, the WIPP. Thus, the SR Program also supports WIPP operations. The SR site specific goals are to phase out the indefinite storage of TRU waste, which has been the mode of waste management since 1974, and to dispose of the defense TRU waste. This paper describes the specific activities at SR which will provide for the disposal of this TRU waste

1996 Savannah River Site annual epidemiologic surveillance report

Energy Technology Data Exchange (ETDEWEB)

None

2000-03-01

This report provides a summary of epidemiologic surveillance data collected from Savannah River Site from January 1, 1996 through December 31, 1996. The data were collected by a coordinator at Savannah River Site and submitted to the Epidemiologic Surveillance Data Center located at Oak Ridge Institute for Science and Education, where quality control procedures and preliminary data analyses were carried out. The analyses were interpreted and the final report prepared by the DOE Office of Epidemiologic Studies. The information in this report provides highlights of the data analyses conducted on the 1996 data collected from Savannah River Site. The main sections of the report include: work force characteristics; absences due to injury or illness lasting 5 or more consecutive workdays; workplace illnesses, injuries, and deaths that were reportable to the Occupational Safety and Health Administration (''OSHA-recordable'' events); and disabilities and deaths among current workers. The 1996 report includes a new section on time trends that provides comparative information on the health of the work force from 1994 through 1996.

1997 Savannah River Site annual epidemiologic surveillance report

Energy Technology Data Exchange (ETDEWEB)

None

2000-06-01

This report provides a summary of epidemiologic surveillance data collected from Savannah River Site from January 1, 1997 through December 31, 1997. The data were collected by a coordinator at Savannah River Site and submitted to the Epidemiologic Surveillance Data Center located at Oak Ridge Institute for Science and Education, where quality control procedures and preliminary data analyses were carried out. The analyses were interpreted and the final report prepared by the DOE Office of Epidemiologic Studies. The information in this report provides highlights of the data analyses conducted on the 1997 data collected from Savannah River Site. The main sections of the report include: work force characteristics; absences due to injury or illness lasting 5 or more consecutive workdays; workplace illnesses, injuries, and deaths that were reportable to the Occupational Safety and Health Administration (''OSHA-recordable'' events); and disabilities and deaths among current workers. The 199 7 report includes a section on time trends that provides comparative information on the health of the work force from 1994 through 1997.

Mixed waste disposal facilities at the Savannah River Site

International Nuclear Information System (INIS)

Wells, M.N.; Bailey, L.L.

1991-01-01

The Savannah River Site (SRS) is a key installation of the US Department of Energy (DOE). The site is managed by DOE's Savannah River Field Office and operated under contract by the Westinghouse Savannah River Company (WSRC). The Site's waste management policies reflect a continuing commitment to the environment. Waste minimization, recycling, use of effective pre-disposal treatments, and repository monitoring are high priorities at the site. One primary objective is to safely treat and dispose of process wastes from operations at the site. To meet this objective, several new projects are currently being developed, including the M-Area Waste Disposal Project (Y-Area) which will treat and dispose of mixed liquid wastes, and the Hazardous Waste/Mixed Waste Disposal Facility (HW/MWDF), which will store, treat, and dispose of solid mixed and hazardous wastes. This document provides a description of this facility and its mission

Model-based analysis of δ34S signatures to trace sedimentary pyrite oxidation during managed aquifer recharge in a heterogeneous aquifer

Science.gov (United States)

Seibert, Simone; Descourvieres, Carlos; Skrzypek, Grzegorz; Deng, Hailin; Prommer, Henning

2017-05-01

The oxidation of pyrite is often one of the main drivers affecting groundwater quality during managed aquifer recharge in deep aquifers. Data and techniques that allow detailed identification and quantification of pyrite oxidation are therefore crucial for assessing and predicting the adverse water quality changes that may be associated with this process. In this study, we explore the benefits of combining stable sulphur isotope analysis with reactive transport modelling to improve the identification and characterisation of pyrite oxidation during an aquifer storage and recovery experiment in a chemically and physically heterogeneous aquifer. We characterise the stable sulphur isotope signal (δ34S) in both the ambient groundwater and the injectant as well as its spatial distribution within the sedimentary sulphur species. The identified stable sulphur isotope signal for pyrite was found to vary between -32 and +34‰, while the signal of the injectant ranged between +9.06 and +14.45‰ during the injection phase of the experiment. Both isotope and hydrochemical data together suggest a substantial contribution of pyrite oxidation to the observed, temporally variable δ34S signals. The variability of the δ34S signal in pyrite and the injectant were both found to complicate the analysis of the stable isotope data. However, the incorporation of the data into a numerical modelling approach allowed to successfully employ the δ34S signatures as a valuable additional constraint for identifying and quantifying the contribution of pyrite oxidation to the redox transformations that occur in response to the injection of oxygenated water.

Galvanic Interaction between Chalcopyrite and Pyrite with Low Alloy and High Carbon Chromium Steel Ball

Directory of Open Access Journals (Sweden)

Asghar Azizi

2013-01-01

Full Text Available This study was aimed to investigate the galvanic interaction between pyrite and chalcopyrite with two types of grinding media (low alloy and high carbon chromium steel ball in grinding of a porphyry copper sulphide ore. Results indicated that injection of different gases into mill altered the oxidation-reduction environment during grinding. High carbon chromium steel ball under nitrogen gas has the lowest galvanic current, and low alloy steel ball under oxygen gas had the highest galvanic current. Also, results showed that the media is anodic relative to pyrite and chalcopyrite, and therefore pyrite or chalcopyrite with a higher rest potential acted as the cathode, whilst the grinding media with a lower rest potential acted as the anode, when they are electrochemically contacted. It was also found that low alloy steel under oxygen produced the highest amount of EDTA extractable iron in the slurry, whilst high carbon chromium steel under nitrogen atmosphere led to the lowest amount.

Savannah River Laboratory monthly report, November 1991

Energy Technology Data Exchange (ETDEWEB)

Ferrell, J.M. (comp.)

1991-01-01

This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation; tritium facilities and production; separation operations; environmental concerns; and waste management. (FI)

Savannah River Laboratory monthly report, November 1991

Energy Technology Data Exchange (ETDEWEB)

Ferrell, J.M. [comp.

1991-12-31

This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation; tritium facilities and production; separation operations; environmental concerns; and waste management. (FI)

Savannah River Laboratory monthly report, September 1991

Energy Technology Data Exchange (ETDEWEB)

Ferrell, J.M. (comp.)

1991-01-01

This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation, tritium facilities and production; separation operations; environmental concerns; and waste management. (FI)

Savannah River Laboratory monthly report, September 1991

Energy Technology Data Exchange (ETDEWEB)

Ferrell, J.M. [comp.

1991-12-31

This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation, tritium facilities and production; separation operations; environmental concerns; and waste management. (FI)

Savannah River Laboratory monthly report, October 1991

Energy Technology Data Exchange (ETDEWEB)

Ferrell, J.M. (comp.)

1991-01-01

This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation, tritium facilities and production; separations operations; environmental concerns; and waste management. (FI)

Savannah River Laboratory monthly report, October 1991

Energy Technology Data Exchange (ETDEWEB)

Ferrell, J.M. [comp.

1991-12-31

This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation, tritium facilities and production; separations operations; environmental concerns; and waste management. (FI)

On the mechanism of action of combination of thionocarbamates with xanthate during flotation of copper-molybdenum pyrite contained ores

International Nuclear Information System (INIS)

Nedosekina, T.V.; Glembotskij, A.V.; Bekhtle, G.A.; Novgorodova, Eh.Z.

1985-01-01

Investigation results of action mechanism of thionocarbamates combination with xanthate are described. It is established that these collectors are capable of co-adsorbing on pyrite surface, that is the reason for sharp increase of the floatability and disturbs the selectivity of copper-molybdenum pyrite-containing ore flotation

Authigenic 10Be/9Be ratio signatures of the cosmogenic nuclide production linked to geomagnetic dipole moment variation since the Brunhes/Matuyama boundary.

Science.gov (United States)

Simon, Quentin; Thouveny, Nicolas; Bourlès, Didier L; Valet, Jean-Pierre; Bassinot, Franck; Ménabréaz, Lucie; Guillou, Valéry; Choy, Sandrine; Beaufort, Luc

2016-11-01

Geomagnetic dipole moment variations associated with polarity reversals and excursions are expressed by large changes of the cosmogenic nuclide beryllium-10 ( 10 Be) production rates. Authigenic 10 Be/ 9 Be ratios (proxy of atmospheric 10 Be production) from oceanic cores therefore complete the classical information derived from relative paleointensity (RPI) records. This study presents new authigenic 10 Be/ 9 Be ratio results obtained from cores MD05-2920 and MD05-2930 collected in the west equatorial Pacific Ocean. Be ratios from cores MD05-2920, MD05-2930 and MD90-0961 have been stacked and averaged. Variations of the authigenic 10 Be/ 9 Be ratio are analyzed and compared with the geomagnetic dipole low series reported from global RPI stacks. The largest 10 Be overproduction episodes are related to dipole field collapses (below a threshold of 2 × 10 22  Am 2 ) associated with the Brunhes/Matuyama reversal, the Laschamp (41 ka) excursion, and the Iceland Basin event (190 ka). Other significant 10 Be production peaks are correlated to geomagnetic excursions reported in literature. The record was then calibrated by using absolute dipole moment values drawn from the Geomagia and Pint paleointensity value databases. The 10 Be-derived geomagnetic dipole moment record, independent from sedimentary paleomagnetic data, covers the Brunhes-Matuyama transition and the whole Brunhes Chron. It provides new and complementary data on the amplitude and timing of millennial-scale geomagnetic dipole moment variations and particularly on dipole moment collapses triggering polarity instabilities.

Advanced separations at Savannah River Site

International Nuclear Information System (INIS)

Thompson, M.; McCabe, D.

1996-01-01

The Savannah River Site (SRS) has many waste streams that are contaminated with radionuclides and/or hazardous materials that must be treated to remove the radioactivity (cesium, strontium, tritium, actinides) and hazardous components (polychlorinated biphenyls (PCBs), cyanide, metal ions)

Mineralogical variations across Mariano Lake roll-type uranium deposits, McKinley County

International Nuclear Information System (INIS)

Sachdev, S.C.

1980-01-01

Mineralogy of core samples from the Mariano orebody was determined. The data obtained were used to develop exploration tools for roll-type uranium deposits. Preliminary interpretations of the physical and chemical conditions of ore deposition were made on the basis of paragenetic relationships. The host sandstones occur between the bentonitic rock units and contain scattered intercalations of detrital montmorillonitic material in the form of clay galls, stringers, and lenses derived from these bentonites. Authigenic clay minerals identified in the host rocks include cellular montmorillonite, platy chlorite, and pseudohexagonal books of kaolinite. The cellular montmorillonite is concentrated in the oxidized zone and appears to have formed prior to ore deposition. Authigenic chlorite is most abundant in the ore zone and has formed at the expense of cellular montmorillonite; its formation is interpreted as being related to the ore-forming processes. Kaolinite in sandstones is the last clay mineral to form and is enriched in the reduced zone. Calcite, considered typical of such deposits, is not found in this orebody. Iron-titanium oxides and their alteration products are the most abundant heavy-mineral species in the host rocks. In addition to anatase and rutile, the alteration products include hematite in the oxidized zone and pyrite in the ore and reduced zones. Carbonaceous material introudced later into the potential ore zone appears to have been responsible for the decomposition of Fe-Ti oxides and the formation of pyrite. The paragenetic relationship indicates oxidation of pyrite by mineralizing solutions, resulting in reduction and subsequent deposition of uranium. The positive correlation between organic carbon and uranium suggests that carbonaceous material also acted as a reductant for uranium

Chemical vapour transport of pyrite (FeS 2) with halogen (Cl, Br, I)

Science.gov (United States)

Fiechter, S.; Mai, J.; Ennaoui, A.; Szacki, W.

1986-12-01

A systematic study of chemical vapour transport (CVT) of pyrite with halogen, hydrogen halides and ammonium halides as transporting agents has shown that the transport with chlorine and bromine in a temperature gradient Δ T = 920-820 K yields the highest transport rates (˜6 mg/h) with crystals up to 5 mm edge length. Computing thermochemical equilibria and flux functions in the system Fe-S-Hal (Hal = Cl, Br, I) it has been confirmed that the transport velocity of pyrite is limited by the concentration of FeHal 2 in the vapour phase, the equilibrium position between FeHal 2(g) and FeHal 3(g) and the flux directions of the iron gas species.

Strategies for Reduced Acid and Metalliferous Drainage by Pyrite Surface Passivation

Directory of Open Access Journals (Sweden)

Gujie Qian

2017-03-01

Full Text Available Acid and metalliferous drainage (AMD is broadly accepted to be a major global environmental problem facing the mining industry, requiring expensive management and mitigation. A series of laboratory-scale kinetic leach column (KLC experiments, using both synthetic and natural mine wastes, were carried out to test the efficacy of our pyrite passivation strategy (developed from previous research for robust and sustainable AMD management. For the synthetic waste KLC tests, initial treatment with lime-saturated water was found to be of paramount importance for maintaining long-term circum-neutral pH, favourable for the formation and preservation of the pyrite surface passivating layer and reduced acid generation rate. Following the initial lime-saturated water treatment, minimal additional alkalinity (calcite-saturated water was required to maintain circum-neutral pH for the maintenance of pyrite surface passivation. KLC tests examining natural potentially acid forming (PAF waste, with much greater peak acidity than that of the synthetic waste, blended with lime (≈2 wt % with and without natural non-acid-forming (NAF waste covers, were carried out. The addition of lime and use of NAF covers maintained circum-neutral leachate pH up to 24 weeks. During this time, the net acidity generated was found to be significantly reduced by the overlying NAF cover. If the reduced rate of acidity production from the natural PAF waste is sustained, the addition of smaller (more economically-feasible amounts of lime, together with application of NAF wastes as covers, could be trialled as a potential cost-effective AMD mitigation strategy.

A review of the fundamental studies of the copper activation mechanisms for selective flotation of the sulfide minerals, sphalerite and pyrite.

Science.gov (United States)

Chandra, A P; Gerson, A R

2009-01-30

A review of the considerable, but often contradictory, literature examining the specific surface reactions associated with copper adsorption onto the common metal sulfide minerals sphalerite, (Zn,Fe)S, and pyrite (FeS(2)), and the effect of the co-location of the two minerals is presented. Copper "activation", involving the surface adsorption of copper species from solution onto mineral surfaces to activate the surface for hydrophobic collector attachment, is an important step in the flotation and separation of minerals in an ore. Due to the complexity of metal sulfide mineral containing systems this activation process and the emergence of activation products on the mineral surfaces are not fully understood for most sulfide minerals even after decades of research. Factors such as copper concentration, activation time, pH, surface charge, extent of pre-oxidation, water and surface contaminants, pulp potential and galvanic interactions are important factors affecting copper activation of sphalerite and pyrite. A high pH, the correct reagent concentration and activation time and a short time delay between reagent additions is favourable for separation of sphalerite from pyrite. Sufficient oxidation potential is also needed (through O(2) conditioning) to maintain effective galvanic interactions between sphalerite and pyrite. This ensures pyrite is sufficiently depressed while sphalerite floats. Good water quality with low concentrations of contaminant ions, such as Pb(2+)and Fe(2+), is also needed to limit inadvertent activation and flotation of pyrite into zinc concentrates. Selectivity can further be increased and reagent use minimised by opting for inert grinding and by carefully choosing selective pyrite depressants such as sulfoxy or cyanide reagents. Studies that approximate plant conditions are essential for the development of better separation techniques and methodologies. Improved experimental approaches and surface sensitive techniques with high spatial

Application of a simple parameter estimation method to predict effluent transport in the Savannah River

International Nuclear Information System (INIS)

Hensel, S.J.; Hayes, D.W.

1993-01-01

A simple parameter estimation method has been developed to determine the dispersion and velocity parameters associated with stream/river transport. The unsteady one dimensional Burgers' equation was chosen as the model equation, and the method has been applied to recent Savannah River dye tracer studies. The computed Savannah River transport coefficients compare favorably with documented values, and the time/concentration curves calculated from these coefficients compare well with the actual tracer data. The coefficients were used as a predictive capability and applied to Savannah River tritium concentration data obtained during the December 1991 accidental tritium discharge from the Savannah River Site. The peak tritium concentration at the intersection of Highway 301 and the Savannah River was underpredicted by only 5% using the coefficients computed from the dye data

The Influence of Pyrite on the Solubility of Minjingu and Panda ...

African Journals Online (AJOL)

28.5 million tons of sulphur. This study was ... bining PRs with elemental S, FYM ot 'and pyrite rock rere used.in this compost (Chien et al., ... Some of the possibility of using locally available the chemical properties of the rocks materials in ...

Gold and trace element zonation in pyrite using a laser imaging technique: Implications for the timing of gold in orogenic and carlin-style sediment-hosted deposits

Science.gov (United States)

Large, R.R.; Danyushevsky, L.; Hollit, C.; Maslennikov, V.; Meffre, S.; Gilbert, S.; Bull, S.; Scott, R.; Emsbo, P.; Thomas, H.; Singh, B.; Foster, J.

2009-01-01

Laser ablation ICP-MS imaging of gold and other trace elements in pyrite from four different sediment- hosted gold-arsenic deposits has revealed two distinct episodes of gold enrichment in each deposit: an early synsedimentary stage where invisible gold is concentrated in arsenian diagenetic pyrite along with other trace elements, in particular, As, Ni, Pb, Zn, Ag, Mo, Te, V, and Se; and a later hydrothermal stage where gold forms as either free gold grains in cracks in overgrowth metamorphic and/or hydrothermal pyrite or as narrow gold- arsenic rims on the outermost parts of the overgrowth hydrothermal pyrite. Compared to the diagenetic pyrites, the hydrothermal pyrites are commonly depleted in Ni, V, Zn, Pb, and Ag with cyclic zones of Co, Ni, and As concentration. The outermost hydrothermal pyrite rims are either As-Au rich, as in moderate- to high- grade deposits such as Carlin and Bendigo, or Co-Ni rich and As-Au poor as in moderate- to low-grade deposits such as Sukhoi Log and Spanish Mountain. The early enrichment of gold in arsenic-bearing syngenetic to diagenetic pyrite, within black shale facies of sedimentary basins, is proposed as a critical requirement for the later development of Carlin-style and orogenic gold deposits in sedimentary environments. The best grade sediment-hosted deposits appear to have the gold climax event, toward the final stages of deformation-related hydrothermal pyrite growth and fluid flow. ?? 2009 Society of Economic Geologists, Inc.

Abiotic pyrite reactivity versus nitrate, selenate and selenite using chemical and electrochemical methods

International Nuclear Information System (INIS)

Ignatiadis, I.; Betelu, S.; Gaucher, E.; Tournassat, C.; Chainet, F.

2010-01-01

Document available in extended abstract form only. This work is part of ReCosy European project (www.recosy.eu), whose main objectives are the sound understanding of redox phenomena controlling the long-term release/retention of radionuclides in nuclear waste disposal and providing tools to apply the results to performance assessment/safety case. Redox is one of the main factor affecting speciation and mobility of redox-sensitive radionuclides. Thus, it is of a great importance to investigate the redox reactivity of the host radioactive waste formations, particularly when exposed to redox perturbations. Callovo-Oxfordian formation (COx), a clay rock known as an anoxic and reducing system, was selected in France as the most suitable location to store nuclear waste. Iron (II) sulfide, mostly constituted of pyrite (FeS 2 ), iron (II) carbonate, iron(II) bearing clays and organic matter are considered to account almost entirely for the total reducing capacity of the rock. We report here the redox reactivity of pyrite upon exposure to nitrate (N(V)), selenate (Se(VI)) and selenite (Se(IV)) that possibly occur in the nuclear storage. Both, chemical and electrochemical kinetic approaches were simultaneously conducted such as to (i) determine the kinetics parameters of the reactions and (ii) understand the kinetic mechanisms. In order to reach similar conditions that are encountered in the storage system, all experiments were realised in NaCl 0.1 M, near neutral pH solutions, and an abiotic glove box (O 2 less than 10 -8 M). Chemical approach has consisted to set in contact pyrite in grains with solutions containing respectively nitrate, selenate and selenite. Reactants and products chemical analyses, conducted at different contact times, allowed us to assess the kinetics of oxidant reduction. Electrochemical approach has consisted in the continuous or semi-continuous analysis of large surface pyrite electrodes immersed in solutions with or without oxidant (nitrate

Efficient hydrogen evolution catalysis using ternary pyrite-type cobalt phosphosulphide

KAUST Repository

Cabán-Acevedo, Miguel

2015-09-14

The scalable and sustainable production of hydrogen fuel through water splitting demands efficient and robust Earth-abundant catalysts for the hydrogen evolution reaction (HER). Building on promising metal compounds with high HER catalytic activity, such as pyrite structure cobalt disulphide (CoS 2), and substituting non-metal elements to tune the hydrogen adsorption free energy could lead to further improvements in catalytic activity. Here we present a combined theoretical and experimental study to establish ternary pyrite-type cobalt phosphosulphide (CoPS) as a high-performance Earth-abundant catalyst for electrochemical and photoelectrochemical hydrogen production. Nanostructured CoPS electrodes achieved a geometrical catalytic current density of 10 mA cm at overpotentials as low as 48mV, with outstanding long-term operational stability. Integrated photocathodes of CoPS on n -p-p silicon micropyramids achieved photocurrents up to 35 mA cm at 0 V versus the reversible hydrogen electrode (RHE), onset photovoltages as high as 450 mV versus RHE, and the most efficient solar-driven hydrogen generation from Earth-abundant systems.

Archaeal diversity and the extent of iron and manganese pyritization in sediments from a tropical mangrove creek (Cardoso Island, Brazil)

Science.gov (United States)

Otero, X. L.; Lucheta, A. R.; Ferreira, T. O.; Huerta-Díaz, M. A.; Lambais, M. R.

2014-06-01

Even though several studies on the geochemical processes occurring in mangrove soils and sediments have been performed, information on the diversity of Archaea and their functional roles in these ecosystems, especially in subsurface environments, is scarce. In this study, we have analyzed the depth distribution of Archaea and their possible relationships with the geochemical transformations of Fe and Mn in a sediment core from a tropical mangrove creek, using 16S rRNA gene profiling and sequential extraction of different forms of Fe and Mn. A significant shift in the archaeal community structure was observed in the lower layers (90-100 cm), coinciding with a clear decrease in total organic carbon (TOC) content and an increase in the percentage of sand. The comparison of the archaeal communities showed a dominance of methanogenic Euryarchaeota in the upper layers (0-20 cm), whereas Crenarchaeota was the most abundant taxon in the lower layers. The dominance of methanogenic Euryarchaeota in the upper layer of the sediment suggests the occurrence of methanogenesis in anoxic microenvironments. The concentrations of Fe-oxyhydroxides in the profile were very low, and showed positive correlation with the concentrations of pyrite and degrees of Fe and Mn pyritization. Additionally, a partial decoupling of pyrite formation from organic matter concentration was observed, suggesting excessive Fe pyritization. This overpyritization of Fe can be explained either by the anoxic oxidation of methane by sulfate and/or by detrital pyrite tidal transportation from the surrounding mangrove soils. The higher pyritization levels observed in deeper layers of the creek sediment were also in agreement with its Pleistocenic origin.

Sandstone uranium deposits: analogues for surf disposal in some sedimentary rocks

International Nuclear Information System (INIS)

Brookins, D.G.

1987-01-01

Sandstone uranium deposits are well suited as analogs for SURF. These deposits typically occur as tabular or lensoid masses of uraniferous sandstone, commonly where the argillaceous mineral and organic content is high. Primary minerals consist of pitchblende and/or coffinite, with possibly some urano-organic phases as well. The ore is usually associated with authigenic ferromagnesian clay minerals, such as chlorite and/or authigenic illite and/or mixed layer smectite-illite; and with pyrite ± jordisite ± seleniferrous species ± calcite. Organic matter is usually associated with the ore. The clay minerals in the ore zones are commonly vanadiferrous. The genesis of the sandstone uranium deposits is now fairly well understood and allows semi-quantitative estimates to be placed on behaviour of analog-elements for many constituents of SURF (or HLW). Prior to mineralization, oxidized species of U, V, Se, Mo, As are carried together as oxyanions; these species precipitate in a restricted range of Eh-pH when reducing conditions are met. Concomitant with removal of these species, due to formation of reduced, insoluble species, several other elements of interest are concentrated in the ore zones as well. Chalcophile elements, such as Cu, Co, Mn, Zn, Cd, Sb, and others are fixed in authigenic sulfide phases, and the alkalis Rb, K, and Cs are fixed in the authigenic illite and illitic mixed layer clays. The alkaline earth elements Sr and Ba are commonly fixed in sulfate-rich rock. The rare earth elements (REE) are incorporated into authigenic clay minerals or into oxy-hydroxide phases. (author)

Savannah River Site peer evaluator standards: Operator assessment for restart

International Nuclear Information System (INIS)

1990-01-01

Savannah River Site has implemented a Peer Evaluator program for the assessment of certified Central Control Room Operators, Central Control Room Supervisors and Shift Technical Engineers prior to restart. This program is modeled after the nuclear Regulatory Commission's (NRC's) Examiner Standard, ES-601, for the requalification of licensed operators in the commercial utility industry. It has been tailored to reflect the unique differences between Savannah River production reactors and commercial power reactors

Determination of rare earth, major and trace elements in authigenic fraction of Andaman Sea (Northeastern Indian Ocean) sediments by inductively coupled plasma-mass spectrometry

Digital Repository Service at National Institute of Oceanography (India)

Alagarsamy, R.; You, C.-F.; Nath, B.N.; SijinKumar, A.V.

Downcore variation of rare earth elements (REEs) in the authigenic Fe-Mn oxides of a sediment core (covering a record of last approx. 40 kyr) from the Andaman Sea, a part of the Indian Ocean shows distinctive positive Ce and Eu anomalies...

Machinery Vibration Monitoring Program at the Savannah River Site

International Nuclear Information System (INIS)

Potvin, M.M.

1990-01-01

The Reactor Maintenance's Machinery Vibration Monitoring Program (MVMP) plays an essential role in ensuring the safe operation of the three Production Reactors at the Westinghouse Savannah River Company (WRSC) Savannah River Site (SRS). This program has increased machinery availability and reduced maintenance cost by the early detection and determination of machinery problems. This paper presents the Reactor Maintenance's Machinery Vibration Monitoring Program, which has been documented based on Electric Power Research Institute's (EPRI) NP-5311, Utility Machinery Monitoring Guide, and some examples of the successes that it has enjoyed

Microbial leaching of iron from pyrite by moderate thermophile chemolithotropic bacteria

International Nuclear Information System (INIS)

Ilyas, S.; Niazi, S.B.

2007-01-01

The present work was aimed at studying the bioleachability of iron from pyrite by the selected moderately thermophilic strains of acidophilic chemolithotrophic and acidophilic heterotrophic bacteria. These included Sulfobacillus thermosulfidooxidans (chemolithotroph) and an un-identified strain of acidophilic heterotroph (code 6A1TSB) isolated from local environments. As compared to inoculated flasks, dissolution of metal (due to acid leaching) was significantly low in the un-inoculated control flasks in all the experiments in ore. A decrease in the bioleaching activity was observed at the later stages of bioleaching of metal from ore. Among the strategies adopted to enhance the metal leaching rates, a mixed consortium of the metal adapted cultures of the above-mentioned bacteria was found to exhibit the maximum metal leaching efficiency. In all the flasks where high metal leaching rates were observed, concomitantly biomass production rates were also high indicating high growth rates. It showed that the metal bioleaching capability of the bacteria was associated with their growth. Pyrite contained 42% iron. (author)

Isolation and characterization of bacteria on the drainage water from Ratones mine and its behaviour on pyrite

International Nuclear Information System (INIS)

Merino, J. L.; Saez, R. M.

1974-01-01

This paper describes some of the studies made about iron and sulfur oxidizing bacteria on the drainage water from Ratones mine. Different liquid and solid media were utilized as well as some energy sources, ferrous sulphate, thiosulfate and sulfur. Some experiment were al so realized on museum grade pyrite aimed at determining the possibilities of applying the mentioned bacteria on the leaching of pyrite and subsequently on the leaching of uranium ores. (Author) 27 refs

Characterization of Savannah River Plant waste glass

International Nuclear Information System (INIS)

Plodinec, M.J.

1985-01-01

The objective of the glass characterization programs at the Savannah River Laboratory (SRL) is to ensure that glass containing Savannah River Plant high-level waste can be permanently stored in a federal repository, in an environmentally acceptable manner. To accomplish this objective, SRL is carrying out several experimental programs, including: fundamental studies of the reactions between waste glass and water, particularly repository groundwater; experiments in which candidate repository environments are simulated as accurately as possible; burial tests of simulated waste glass in candidate repository geologies; large-scale tests of glass durability; and determination of the effects of process conditions on glass quality. In this paper, the strategy and current status of each of these programs is discussed. The results indicate that waste packages containing SRP waste glass will satisfy emerging regulatory criteria

Savannah River interim waste management program plan: FY 1984. Revision 1

International Nuclear Information System (INIS)

1983-10-01

This document provides the program plan as requested by the Savannah River Operations Office of the Department of Energy. The plan was developed to provide a working knowledge of the nature and extent of the interim waste management programs being undertaken by Savannah River (SR) contractors for the Fiscal Year 1984. In addition, the document projects activities for several years beyond 1984 to adequately plan for safe handling and storage of radioactive wastes generated at Savannah River and for developing technology for improved management of low-level solid wastes. A revised plan will be issued prior to the beginning of the first quarter of each fiscal year. In this document, work descriptions and milestone schedules are current as of the date of publication. Budgets are based on available information as of June 1983

Waste certification review program at the Savannah River Site

International Nuclear Information System (INIS)

Faulk, G.W.; Kinney, J.C.; Knapp, D.C.; Burdette, T.E.

1996-01-01

After approving the waste certification programs for 45 generators of low-level radioactive and mixed waste, Westinghouse Savannah River Company (WSRC) moved forward to implement a performance-based approach for assuring that approved waste generators maintain their waste certification programs. WSRC implemented the Waste Certification Review Program, which is comprised of two sitewide programs, waste generator self-assessments and Facility Evaluation Board reviews, integrated with the WSRC Solid Waste Management Department Waste Verification Program Evaluations. The waste generator self-assessments ensure compliance with waste certification requirements, and Facility Evaluation Board reviews provide independent oversight of generators' waste certification programs. Waste verification evaluations by the TSD facilities serve as the foundation of the program by confirming that waste contents and generator performance continue to meet waste acceptance criteria (WSRC 1994) prior to shipment to treatment, storage, and disposal facilities. Construction of the Savannah River Site (SRS) was started by the US Government in 1950. The site covers approximately 300 square miles located along the Savannah River near Aiken, South Carolina. It is operated by the US Department of Energy (DOE). Operations are conducted by managing and operating contractors, including the Westinghouse Savannah River Company (WSRC). Historically, the primary purpose of the SRS was to produce special nuclear materials, primarily plutonium and tritium. In general, low-level radioactive and mixed waste is generated through activities in operations. Presently, 47 SRS facilities generate low-level radioactive and mixed waste. The policies, guidelines, and requirements for managing these wastes are determined by DOE and are reflected in DOE Order 5820.2A (US DOE 1988)

Waterfowl of the Savannah River Plant: Comprehensive cooling water study. Final report

Energy Technology Data Exchange (ETDEWEB)

Mayer, J.J.; Kennamer, R.A.; Hoppe, R.T.

1986-06-01

Thirty-one species of waterfowl have been documented on the Savannah River Plant (SPR). The Savannah River Ecology Laboratory (SREL) has been conducting waterfowl research on the site for the past 15 years. This research has included work on waterfowl utilization of the SRP, wood duck reproductive biology, and waterfowl wintering ecology. Results are described.

Complete removal of AHPS synthetic dye from water using new electro-fenton oxidation catalyzed by natural pyrite as heterogeneous catalyst.

Science.gov (United States)

Labiadh, Lazhar; Oturan, Mehmet A; Panizza, Marco; Hamadi, Nawfel Ben; Ammar, Salah

2015-10-30

The mineralization of a new azo dye - the (4-amino-3-hydroxy-2-p-tolylazo-naphthalene-1-sulfonic acid) (AHPS) - has been studied by a novel electrochemical advanced oxidation process (EAOP), consisting in electro-Fenton (EF) oxidation, catalyzed by pyrite as the heterogeneous catalyst - the so-called 'pyrite-EF'. This solid pyrite used as heterogeneous catalyst instead of a soluble iron salt, is the catalyst the system needs for production of hydroxyl radicals. Experiments were performed in an undivided cell equipped with a BDD anode and a commercial carbon felt cathode to electrogenerate in situ H2O2 and regenerate ferrous ions as catalyst. The effects on operating parameters, such as applied current, pyrite concentration and initial dye content, were investigated. AHPS decay and mineralization efficiencies were monitored by HPLC analyses and TOC measurements, respectively. Experimental results showed that AHPS was quickly oxidized by hydroxyl radicals (OH) produced simultaneously both on BDD surface by water discharge and in solution bulk from electrochemically assisted Fenton's reaction with a pseudo-first-order reaction. AHPS solutions with 175 mg L(-1) (100 mg L(-1) initial TOC) content were then almost completely mineralized in 8h. Moreover, the results demonstrated that, under the same conditions, AHPS degradation by pyrite electro-Fenton process was more powerful than the conventional electro-Fenton process. Copyright © 2015 Elsevier B.V. All rights reserved.

Short communication: Adverse effect of surface-active reagents on the bioleaching of pyrite and chalcopyrite by Thiobacillus ferrooxidans.

Science.gov (United States)

Huerta, G; Escobar, B; Rubio, J; Badilla-Ohlbaum, R

1995-09-01

Oxidation of Fe(II) iron and bioleaching of pyrite and chalcopyrite by Thiobacillus ferrooxidans was adversely affected by isopropylxanthate, a flotation agent, and by LIX 984, a solvent-extraction agent, each at ≤ 1 g/l. The reagents/l were adsorbed on the bacterial surface, decreasing the bacteria's development and preventing biooxidation. Both reagents inhibited the bioleaching of pyrite and LIX 984 also inhibited the bioleaching of chalcopyrite.

Effects of pyrite and sphalerite on population compositions, dynamics and copper extraction efficiency in chalcopyrite bioleaching process.

Science.gov (United States)

Xiao, Yunhua; Liu, Xueduan; Dong, Weiling; Liang, Yili; Niu, Jiaojiao; Gu, Yabing; Ma, Liyuan; Hao, Xiaodong; Zhang, Xian; Xu, Zhen; Yin, Huaqun

2017-07-01

This study used an artificial microbial community with four known moderately thermophilic acidophiles (three bacteria including Acidithiobacillus caldus S1, Sulfobacillus thermosulfidooxidans ST and Leptospirillum ferriphilum YSK, and one archaea, Ferroplasma thermophilum L1) to explore the variation of microbial community structure, composition, dynamics and function (e.g., copper extraction efficiency) in chalcopyrite bioleaching (C) systems with additions of pyrite (CP) or sphalerite (CS). The community compositions and dynamics in the solution and on the ore surface were investigated by real-time quantitative PCR (qPCR). The results showed that the addition of pyrite or sphalerite changed the microbial community composition and dynamics dramatically during the chalcopyrite bioleaching process. For example, A. caldus (above 60%) was the dominant species at the initial stage in three groups, and at the middle stage, still dominated C group (above 70%), but it was replaced by L. ferriphilum (above 60%) in CP and CS groups; at the final stage, L. ferriphilum dominated C group, while F. thermophilum dominated CP group on the ore surface. Furthermore, the additions of pyrite or sphalerite both made the increase of redox potential (ORP) and the concentrations of Fe 3+ and H + , which would affect the microbial community compositions and copper extraction efficiency. Additionally, pyrite could enhance copper extraction efficiency (e.g., improving around 13.2% on day 6) during chalcopyrite bioleaching; on the contrary, sphalerite restrained it.

Savannah River Site Environmental Report for 1997

Energy Technology Data Exchange (ETDEWEB)

Arnett, M.W.; Mamatey, A.R. [eds.

1998-08-01

The mission at the Savannah River Site has changed from the production of nuclear weapons materials for national defense to the management of waste, restoration of the environment, and the development of industry in and around the site.

Savannah River Site Environmental Report for 1997

International Nuclear Information System (INIS)

Arnett, M.W.; Mamatey, A.R.

1998-01-01

The mission at the Savannah River Site has changed from the production of nuclear weapons materials for national defense to the management of waste, restoration of the environment, and the development of industry in and around the site

Pyrite as a proxy for the identification of former coastal lagoons in semiarid NE Brazil

Science.gov (United States)

Ferreira, Tiago O.; Nóbrega, Gabriel N.; Albuquerque, Antonia G. B. M.; Sartor, Lucas R.; Gomes, Irlene S.; Artur, Adriana G.; Otero, Xosé L.

2015-10-01

This work aimed to test the suitability of pyrite (FeS2) as a proxy for reconstructing past marine environmental conditions along the semiarid coast of Brazil. Morphological description combined with physicochemical analyses including Fe partitioning were conducted for soil depth profiles (30 and 60 cm depths) at three sites in two contrasting lagoons of the state of Ceará: a suspected former lagoon that would have been transformed into a freshwater "lake" at a site vegetated by Juncus effusus (site P1), and another lagoon with connection to the sea at sites vegetated by J. effusus (site P2) or Portulaca oleracea (site P3). Soil samples were collected in September 2010. Site P3 had more reducing conditions, reaching Eh values of -132 mV in the surface layer (0-10 cm), whereas minimum values for the P1 and P2 sites were +219 and +85 mV, respectively. Lower pyritic Fe values were found at site P1, with a degree of pyritization (DOP) ranging from 10 to 13%. At sites P2 and P3, DOP ranged from 9 to 67% and from 55 to 72%, respectively. These results are consistent with an interruption of tidal channels by eolian dune migration inducing strong changes in the hydrodynamics and physicochemical characteristics (lower salinity, oxidizing conditions) of these sites, causing the dieback of suspected former mangroves and a succession to freshwater marshes with an intermediate salt marsh stage. Together with other physicochemical signatures, pyrite can evidently serve as a useful proxy in tracking environmental changes in such ecotones, with implications for coastal management.

Stable isotopes of authigenic minerals in variably-saturated fractured tuff

International Nuclear Information System (INIS)

Weber, D.S.; Evans, D.D.

1988-11-01

Identifying stable isotope variation and mineralogical changes in fractured rock may help establish the history of climatic and geomorphological processes that might affect the isolation properties of a waste repository site. This study examines the use of the stable isotope ratios of oxygen ( 18 O/ 16 O) and carbon ( 13 C/ 12 C) in authigenic minerals as hydrogeochemical tools tracing low-temperature rock-water interaction in variably-saturated fractured stuff. Isotopic compositions of fracture-filling and rock matrix minerals in the Apache Leap tuff, near Superior, Arizona were concordant with geothermal temperatures and in equilibrium with water isotopically similar to present-day meteoric water and groundwater. Oxygen and carbon isotope ratios of fracture-filling, in unsaturated fractured tuff, displayed an isotopic gradient believed to result from near-surface isotopic enrichment due to evaporation rather than the effects of rock-water interaction. Oxygen isotope ratios of rock matrix opal samples exhibited an isotopic gradient believed to result from, leaching and reprecipitation of silica at depth. Methods and results can be used to further define primary flowpaths and the movement of water in variably-saturated fractured rock. 71 refs., 23 figs., 3 tabs

Stable isotopes of authigenic minerals in variably-saturated fractured tuff

Energy Technology Data Exchange (ETDEWEB)

Weber, D.S.; Evans, D.D.

1988-11-01

Identifying stable isotope variation and mineralogical changes in fractured rock may help establish the history of climatic and geomorphological processes that might affect the isolation properties of a waste repository site. This study examines the use of the stable isotope ratios of oxygen ({sup 18}O/{sup 16}O) and carbon ({sup 13}C/{sup 12}C) in authigenic minerals as hydrogeochemical tools tracing low-temperature rock-water interaction in variably-saturated fractured stuff. Isotopic compositions of fracture-filling and rock matrix minerals in the Apache Leap tuff, near Superior, Arizona were concordant with geothermal temperatures and in equilibrium with water isotopically similar to present-day meteoric water and groundwater. Oxygen and carbon isotope ratios of fracture-filling, in unsaturated fractured tuff, displayed an isotopic gradient believed to result from near-surface isotopic enrichment due to evaporation rather than the effects of rock-water interaction. Oxygen isotope ratios of rock matrix opal samples exhibited an isotopic gradient believed to result from, leaching and reprecipitation of silica at depth. Methods and results can be used to further define primary flowpaths and the movement of water in variably-saturated fractured rock. 71 refs., 23 figs., 3 tabs.

Waterborne Release Monitoring and Surveillance Programs at the Savannah River Site

Energy Technology Data Exchange (ETDEWEB)

Blanchard, A.

1999-03-26

This report documents the liquid release environmental compliance programs currently in place at the Savannah river Site (SRS). Included are descriptions of stream monitoring programs, which measure chemical parameters and radionuclides in site streams and the Savannah river and test representative biological communities within the streams for chemical and radiological uptake. This report also explains the field sampling and analytical capabilities that are available at SRS during both normal and emergency conditions.

Waterborne Release Monitoring and Surveillance Programs at the Savannah River Site

International Nuclear Information System (INIS)

Blanchard, A.

1999-01-01

This report documents the liquid release environmental compliance programs currently in place at the Savannah river Site (SRS). Included are descriptions of stream monitoring programs, which measure chemical parameters and radionuclides in site streams and the Savannah river and test representative biological communities within the streams for chemical and radiological uptake. This report also explains the field sampling and analytical capabilities that are available at SRS during both normal and emergency conditions

Wildflowers of the Savannah River Site

Science.gov (United States)

T. Segar

2015-01-01

This guidebook is a resource to help field personnel (nonbotanists) identify plants on the Savannah River Site (SRS) premises. Although not a complete flora guide, this publication contains information about 123 plant species found on the SRS. Plants are listed by their common names and arranged by the color of the flower.

Savannah River Site nuclear materials management plan FY 2017-2031

Energy Technology Data Exchange (ETDEWEB)

Magoulas, V. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-06-22

The purpose of the Nuclear Materials Management Plan (herein referred to as “this Plan”) is to integrate and document the activities required to disposition the legacy and/or surplus Enriched Uranium (EU) and Plutonium (Pu) and other nuclear materials already stored or anticipated to be received by facilities at the Department of Energy (DOE) Savannah River Site (SRS) as well as the activities to support the DOE Tritium mission. It establishes a planning basis for EU and Pu processing operations in Environmental Management Operations (EMO) facilities through the end of their program missions and for the tritium through the National Nuclear Security Administration (NNSA) Defense Programs (DP) facilities. Its development is a joint effort among the Department of Energy - Savannah River (DOE-SR), DOE – Environmental Management (EM), NNSA Office of Material Management and Minimization (M3), NNSA Savannah River Field Office (SRFO), and the Management and Operations (M&O) contractor, Savannah River Nuclear Solutions, LLC (SRNS). Life-cycle program planning for Nuclear Materials Stabilization and Disposition and the Tritium Enterprise may use this Plan as a basis for the development of the nuclear materials disposition scope and schedule. This Plan assumes full funding to accomplish the required project and operations activities. It is recognized that some aspects of this Plan are pre decisional with regard to National Environmental Policy Act (NEPA); in such cases new NEPA actions will be required.

Savannah River Site environmental report for 1997 summary

International Nuclear Information System (INIS)

Arnett, M.

1997-01-01

The Savannah River Site (SRS) publishes an environmental report each year to provide environmental monitoring and surveillance results to the US Department of Energy (DOE), the public, Congress, state and federal regulators, universities, local governments, the news media, and environmental and civic groups. The Savannah River Site Environmental Report for 1997 (WSRC-TR-97-00322) contains detailed information on site operations, environmental monitoring and surveillance programs, environmental compliance activities, and special projects for calendar year 1997. The purpose of this document is to give a brief overview of the site and its activities, to summarize the site environmental report and the impact of 1997 SRS operations on the environment and the public, and to provide a brief explanation of radiation and dose

Savannah River Site environmental report for 1996 summary

International Nuclear Information System (INIS)

Arnett, M.W.

1997-01-01

The Savannah River Site (SRS) publishes an environmental report each year to provide environmental monitoring and surveillance results to the US department of Energy (DOE), the public, Congress, state and federal regulators, universities, local governments, the news media, environmental and civic groups. The Savannah River Site Environmental Report for 1996 (WSRC-TR-97-0171) contains detailed information on site operations, environmental monitoring and surveillance programs, environmental compliance activities, and special projects for the calendar year 1996. The purpose of this document is to give a brief overview of the site and its activities, to summarize the report and the impact of 1996 SRS operations on the environment and the public, and to provide a brief explanation of radiation and dose

Pyrite thermochemistry, ash agglomeration, and char fragmentation during pulverized coal combustion. Final technical report

Energy Technology Data Exchange (ETDEWEB)

Akan-Etuk, A.; Diaz, R.; Niksa, S.

1991-10-01

The objective of the present work is to introduce an experimental program that will eventually lead to time-resolved iron ash composition over the technological operating domain. The preceding literature survey suggests two important stipulations on any such experimental program. The first stipulation is that good control must be established over the operating conditions, to accurately quantify their effects. The other is that data must be obtained rapidly, to thoroughly cover the important operating domain. This work presents a series of studies that has characterized the desulfurization of pyrite during the early stages of combustion. An experimental system was established and used to monitor the effects of oxygen, temperature, and residence time on the evolution of condensed phase products of the combustion of pure pyrite. (VC)

Response Matrix Method Development Program at Savannah River Laboratory

International Nuclear Information System (INIS)

Sicilian, J.M.

1976-01-01

The Response Matrix Method Development Program at Savannah River Laboratory (SRL) has concentrated on the development of an effective system of computer codes for the analysis of Savannah River Plant (SRP) reactors. The most significant contribution of this program to date has been the verification of the accuracy of diffusion theory codes as used for routine analysis of SRP reactor operation. This paper documents the two steps carried out in achieving this verification: confirmation of the accuracy of the response matrix technique through comparison with experiment and Monte Carlo calculations; and establishment of agreement between diffusion theory and response matrix codes in situations which realistically approximate actual operating conditions

Breeding bird populations and habitat associations within the Savannah River Site (SRS).

Energy Technology Data Exchange (ETDEWEB)

Gauthreaux, Sidney, A.; Steven J. Wagner.

2005-06-29

Gauthreaux, Sidney, A., and Steven J. Wagner. 2005. Breeding bird populations and habitat associations within the Savannah River Site (SRS). Final Report. USDA Forest Service, Savannah River, Aiken, SC. 48 pp. Abstract: During the 1970's and 1980's a dramatic decline occurred in the populations of Neotropical migratory birds, species that breed in North America and winter south of the border in Central and South America and in the Caribbean. In 1991 an international initiative was mounted by U. S. governmental land management agencies, nongovernmental conservation agencies, and the academic and lay ornithological communities to understand the decline of Neotropical migratory birds in the Americas. In cooperation with the USDA Forest Service - Savannah River (FS - SR) we began 1992 a project directed to monitoring population densities of breeding birds using the Breeding Bird Census (BBC) methodology in selected habitats within the Savannah River Site SRS. In addition we related point count data on the occurrence of breeding Neotropical migrants and other bird species to the habitat data gathered by the Forest Inventory and Analysis (FIA) program of the USDA Forest Service and data on habitat treatments within forest stands.

Effect of capping ligands on the optical properties and electronic energies of iron pyrite FeS2 nanocrystals and solid thin films

International Nuclear Information System (INIS)

Zhai, Guangmei; Xie, Rongwei; Wang, Heng; Zhang, Jitao; Yang, Yongzhen; Wang, Hua; Li, Xuemin; Liu, Xuguang; Xu, Bingshe

2016-01-01

In this work, the optical and electronic properties of iron pyrite FeS 2 nanocrystals and solid thin films with various capping ligands were systematically investigated by UV–Vis–NIR absorption spectroscopy, cyclic voltammetry and current density–voltage characteristic measurements. The iron pyrite nanocrystals with various ligands have an indirect band gap of around 1.05 eV and broad absorption spanning into the near-infrared region, exhibiting favorable optical properties for their photovoltaic applications. The electron affinities and ionization potentials of FeS 2 nanocrystals determined through cyclic voltammetry measurements show strong ligand dependence. An energy level shift of up to 190 meV was obtained among the pyrite nanocrystals capped with the ligands employed in this work. The iron pyrite nanocrystal films capped with iodide and 1,2-ethanedithiol exhibit the largest band edge energy shift and conductivity, respectively. Our results not only provide several useful optical and electronic parameters of pyrite nanocrystals for their further use in optoelectronic devices as active layers and/or infrared optical absorption materials, but also highlight the relationship between their surface chemistry and electronic energies. - Highlights: • The energy levels of FeS 2 nanocrystals with various ligands were determined via electrochemical measurements. • The energy levels of FeS 2 nanocrystals showed strong ligand-dependence. • An energy level shift of up to 190 meV was obtained for the pyrite nanocrystals studied in the work. • The conductivities of FeS 2 nanocrystals with different ligands were obtained by current density–voltage measurements.

Savannah River Technology Center. Monthly report

Energy Technology Data Exchange (ETDEWEB)

1994-02-01

This document contains information about the research programs being conducted at the Savannah River Plant. Topics of discussion include: thermal cycling absorption process, development of new alloys, ion exchange, oxalate precipitation, calcination, environmental research, remedial action, ecological risk assessments, chemical analysis of salt cakes, natural phenomena hazards assessment, and sampling of soils and groundwater.

Savannah, Georgia Tsunami Forecast Grids for MOST Model

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Savannah, Georgia Forecast Model Grids provides bathymetric data strictly for tsunami inundation modeling with the Method of Splitting Tsunami (MOST) model. MOST...

Defense Waste Processing Facility, Savannah River Plant

International Nuclear Information System (INIS)

After 10 years of research, development, and testing, the US Department of Energy is building a new facility which will prepare high-level radioactive waste for permanent disposal. The Defense Waste Processing Facility, known as the DWPF, will be the first production-scale facility of its kind in the United States. In the DWPF, high-level waste produced by defense activities at the Savannah River Plant will be processed into a solid form, borosilicate glass, suitable for permanent off-site geologic disposal. With construction beginning in the fall of 1983, the DWPT is scheduled to be operational in 1989. By 2005, the DWPF will have immobilized the backlog of high-level waste which has been accumulating in storage tanks at the Savannah River Plant since 1954. Canisters of the immobilized waste will then be ready for permanent disposal deep under the ground, safely isolated from the environment

Verdine and other associated authigenic (glaucony, phosphate) facies from the surficial sediments of the southwestern continental margin of India

Digital Repository Service at National Institute of Oceanography (India)

Rao, V.P.; Lamboy, M.; Dupeuble, P.A.

spaced contorted clay blades and globules. X-ray mineralogy suggests that these grains are a mixture of verdine dominated minerals. Phyllite C is the principal verdine mineral in the shelf zone. On the continental slope phyllite V dominates between 100... grains from the shelf are mostly homogeneous at low magnification (Fig. 4A). However, at high magnification the authigenic clays are characterized by small con- torted blades (1 Ixm long) at some places and compact clays (Fig. 4B and C) at others...

Improvement in operating incident experience at the Savannah River Burial Ground

International Nuclear Information System (INIS)

Cornman, W.R.

1979-01-01

Low-level radioactive wastes generated at the Savannah River Plant and Laboratory are stored at the Savannah River burial ground. These wastes have accumulated from >20 years of reprocessing nuclear fuels and materials for defense programs at the Savannah River Plant. Burial in earthen trenches and aboveground storage for transuranic materials are the principal modes of storage. The infrequent operating incidents that have occurred during the 20-year period have been analyzed. The incidents can be categorized as those causing airborne contamination, waterborne contamination, or vegetation contamination through penetration of plant roots into contaminated soil. Contamination was generally confined to the immediate area of the burial ground. Several incidents occurred because of unintentional burial or exhumation of material. The frequency of operating incidents decreased with operating experience of the burial ground, averaging only about two incidents per year during the last six years of operation

Rheology of Savannah River Site Tank 42 radioactive sludges. Revision 1

International Nuclear Information System (INIS)

Ha, B.C.; Bibler, N.E.

1995-01-01

Knowledge of the rheology of the radioactive sludge slurries at the Savannah River Site (SRS) is necessary in order to ensure that they can be retrieved from waste tanks and processed for final disposal. At Savannah River Site (SRS), Tank 42 sludge represents one of the first HLW radioactive sludges to be vitrified in the Defense Waste Processing Facility (DWPF). The rheological properties of unwashed Tank 42 sludge slurries at various solids concentrations were measured remotely in the Shielded Cells at the Savannah River Technology Center (SRTC) using a modified Haake Rotovisco viscometer. Rheological properties of Tank 42 radioactive sludge were measured as a function of weight percent total solids to ensure that the first DWPF radioactive sludge batch can be pumped and processed in the DWPF with the current design bases. The yield stress and consistency of the sludge slurries were determined by assuming a Bingham plastic fluid model

Estimating and Analyzing Savannah Phenology with a Lagged Time Series Model

DEFF Research Database (Denmark)

Boke-Olen, Niklas; Lehsten, Veiko; Ardo, Jonas

2016-01-01

cycle due to their areal coverage and can have an effect on the food security in regions that depend on subsistence farming. In this study we investigate how soil moisture, mean annual precipitation, and day length control savannah phenology by developing a lagged time series model. The model uses...... climate data for 15 flux tower sites across four continents, and normalized difference vegetation index from satellite to optimize a statistical phenological model. We show that all three variables can be used to estimate savannah phenology on a global scale. However, it was not possible to create...... a simplified savannah model that works equally well for all sites on the global scale without inclusion of more site specific parameters. The simplified model showed no bias towards tree cover or between continents and resulted in a cross-validated r2 of 0.6 and root mean squared error of 0.1. We therefore...

Transportation Packages to Support Savannah River Site Missions

International Nuclear Information System (INIS)

Opperman, E.

2001-01-01

The Savannah River Site's missions have expanded from primarily a defense mission to one that includes environmental cleanup and the stabilization, storage, and preparation for final disposition of nuclear materials. The development of packaging and the transportation of radioactive materials are playing an ever-increasing role in the successful completion of the site's missions. This paper describes the Savannah River Site and the three strategic mission areas of (1) nuclear materials stewardship, (2) environmental stewardship, and (3) nuclear weapons stockpile stewardship. The materials and components that need to be shipped, and associated packaging, will be described for each of the mission areas. The diverse range of materials requiring shipment include spent fuel, irradiated target assemblies, excess plutonium and uranium materials, high level waste canisters, transuranic wastes, mixed and low level wastes, and nuclear weapons stockpile materials and components. Since many of these materials have been in prolonged storage or resulted from disassembly of components, the composition, size and shape of the materials present packaging and certification challenges that need to be met. Over 30 different package designs are required to support the site's missions. Approximately 15 inbound shipping-legs transport materials into the Savannah River Site and the same number (15) of outgoing shipment-legs are carrying materials from the site for further processing or permanent disposal

Uranium pollution in an estuary affected by pyrite acid mine drainage and releases of naturally occurring radioactive materials

International Nuclear Information System (INIS)

Villa, M.; Manjon, G.; Hurtado, S.; Garcia-Tenorio, R.

2011-01-01

Highlights: → Huelva estuary is affected by former phosphogypsum releases and pyrite acid mine drainage. → Time evolution of uranium concentration is analyzed after halting of NORM releases. → Two new contamination sources are preventing the complete uranium cleaning: (1) The leaching of phosphogypsum stacks located close to Tinto River. (2) Pyrite acid mine drainage. → High uranium concentrations are dissolved in water and precipitate subsequently. - Abstract: After the termination of phosphogypsum discharges to the Huelva estuary (SW Spain), a unique opportunity was presented to study the response of a contaminated environmental compartment after the cessation of its main source of pollution. The evolution over time of uranium concentrations in the estuary is presented to supply new insights into the decontamination of a scenario affected by Naturally Occurring Radioactive Material (NORM) discharges. The cleaning of uranium isotopes from the area has not taken place as rapidly as expected due to leaching from phosphogypsum stacks. An in-depth study using various techniques of analysis, including 234 U/ 238 U and 230 Th/ 232 Th ratios and the decreasing rates of the uranium concentration, enabled a second source of uranium contamination to be discovered. Increased uranium levels due to acid mine drainage from pyrite mines located in the Iberian Pyrite Belt (SW Spain) prevent complete uranium decontamination and, therefore, result in levels nearly twice those of natural background levels.

Environmental monitoring in the vicinity of the Savannah River Plant. Annual report, 1974

International Nuclear Information System (INIS)

1974-01-01

The results obtained from the environmental monitoring program at the Savannah River Plant during 1974 are presented. An inventory of radioactive materials released to the environment, and data on radioactivity in samples of surface air, surface waters, soil, plants, and food are included. Data are also included on pesticides in Savannah River sediment. (U.S.)

The Savannah River Technology Center environmental monitoring field test platform

International Nuclear Information System (INIS)

Rossabi, J.

1993-01-01

Nearly all industrial facilities have been responsible for introducing synthetic chemicals into the environment. The Savannah River Site is no exception. Several areas at the site have been contaminated by chlorinated volatile organic chemicals. Because of the persistence and refractory nature of these contaminants, a complete clean up of the site will take many years. A major focus of the mission of the Environmental Sciences Section of the Savannah River Technology Center is to develop better, faster, and less expensive methods for characterizing, monitoring, and remediating the subsurface. These new methods can then be applied directly at the Savannah River Site and at other contaminated areas in the United States and throughout the world. The Environmental Sciences Section has hosted field testing of many different monitoring technologies over the past two years primarily as a result of the Integrated Demonstration Program sponsored by the Department of Energy's Office of Technology Development. This paper provides an overview of some of the technologies that have been demonstrated at the site and briefly discusses the applicability of these techniques

Continent-wide survey reveals massive decline in African savannah elephants.

Science.gov (United States)

Chase, Michael J; Schlossberg, Scott; Griffin, Curtice R; Bouché, Philippe J C; Djene, Sintayehu W; Elkan, Paul W; Ferreira, Sam; Grossman, Falk; Kohi, Edward Mtarima; Landen, Kelly; Omondi, Patrick; Peltier, Alexis; Selier, S A Jeanetta; Sutcliffe, Robert

2016-01-01

African elephants (Loxodonta africana) are imperiled by poaching and habitat loss. Despite global attention to the plight of elephants, their population sizes and trends are uncertain or unknown over much of Africa. To conserve this iconic species, conservationists need timely, accurate data on elephant populations. Here, we report the results of the Great Elephant Census (GEC), the first continent-wide, standardized survey of African savannah elephants. We also provide the first quantitative model of elephant population trends across Africa. We estimated a population of 352,271 savannah elephants on study sites in 18 countries, representing approximately 93% of all savannah elephants in those countries. Elephant populations in survey areas with historical data decreased by an estimated 144,000 from 2007 to 2014, and populations are currently shrinking by 8% per year continent-wide, primarily due to poaching. Though 84% of elephants occurred in protected areas, many protected areas had carcass ratios that indicated high levels of elephant mortality. Results of the GEC show the necessity of action to end the African elephants' downward trajectory by preventing poaching and protecting habitat.

Continent-wide survey reveals massive decline in African savannah elephants

Directory of Open Access Journals (Sweden)

Michael J. Chase

2016-08-01

Full Text Available African elephants (Loxodonta africana are imperiled by poaching and habitat loss. Despite global attention to the plight of elephants, their population sizes and trends are uncertain or unknown over much of Africa. To conserve this iconic species, conservationists need timely, accurate data on elephant populations. Here, we report the results of the Great Elephant Census (GEC, the first continent-wide, standardized survey of African savannah elephants. We also provide the first quantitative model of elephant population trends across Africa. We estimated a population of 352,271 savannah elephants on study sites in 18 countries, representing approximately 93% of all savannah elephants in those countries. Elephant populations in survey areas with historical data decreased by an estimated 144,000 from 2007 to 2014, and populations are currently shrinking by 8% per year continent-wide, primarily due to poaching. Though 84% of elephants occurred in protected areas, many protected areas had carcass ratios that indicated high levels of elephant mortality. Results of the GEC show the necessity of action to end the African elephants’ downward trajectory by preventing poaching and protecting habitat.

Aerial radiological survey of the Savannah River floodplain. Date of survey: July-October 1983

International Nuclear Information System (INIS)

Boyns, P.K.

1984-12-01

An aerial radiological survey of the Savannah River floodplain was conducted from late July through early October 1983 by EG and G Energy Measurements, Inc. for the United States Department of Energy, Office of Nuclear Safety, and E.I. Du Pont de Nemours and Company, Inc., Savannah River Plant. The survey consisted of airborne measurements of both natural and man-made gamma radiation emanating from the terrestrial surface. These measurements allowed an estimate of the distribution of isotopic concentrations in the floodplain area. Results are reported as isopleths superimposed on maps and aerial photographs of the area. Gamma ray energy spectra are also presented for the net man-made radionuclides. The survey was designed to cover all the Savannah River floodplain (over 8000 flight line miles) from Augusta to Savannah, Georgia. Several areas of man-made activity were detected in the vicinity of the Savannah River Plant (SRP). The presence of 60 Co was not detected below the Lower Three Runs Creek area. The 137 Cs activity decreased rapidly below Lower Three Runs Creek; at a distance of 15 kilometers (9 miles) the annual dose due to 137 Cs was less than 10 millirem (mrem). Typical backgrounds in the survey areas were between 65 and 125 mrem per year. 4 references, 51 figures, 8 tables

Estimation of Potential Evapotranspiration for a Coastal Savannah ...

African Journals Online (AJOL)

Estimation of Potential Evapotranspiration for a Coastal Savannah Environment: ... model which is the recommended standard method for estimating PET. ... model (r = 0.82) and requires only air temperature measurements as in-puts.ac ...

Comparison of authigenic carbonates formation at mud volcanoes and pockmarks in the Portuguese Margin vs. at the Yinazao serpentinite mud volcano in the Marianas forearc

Science.gov (United States)

Magalhaes, V. H.; Freitas, M.; Azevedo, M. R.; Pinheiro, L. M.; Salgueiro, E.; Abrantes, F. F. G.

2017-12-01

On the Portuguese passive continental margin, active and past seepage processes form mud volcanoes and pockmarks at the seafloor. Often associated with these structures are extensive methane-derived authigenic carbonates that form from deep-sourced methane-rich fluids that ascend from deep to the upper sedimentary column and often discharge at the seafloor. These carbonates form within the sediments and are either dominated by dolomite and high-Mg calcites, when formed under a restricted seawater circulation environment, anoxic and low sulphate conditions; or by aragonite and calcite when formed close to or at the seafloor in a high sulphate system. The δ13C values (-56.2‰ VPDB) found on the carbonate-cemented material clearly indicates methane as the major carbon source. On the Yinazao serpentinite mud volcano at an active, non-accretionary, convergent margin, sediment samples from IODP Sites U1491 and U1492 (Exp. 366) contain authigenic minerals such as aragonite, calcite, brucite, gypsum among others. Authigenic aragonite occurs predominantly within the top meters of the cores where both oxidation and seawater circulation in the sedimentary column are higher. In this system, initial results indicate that the major carbon source is most probably not methane but seawater related. This work discusses and compares the major carbon sources in both systems: sedimentary mud volcanoes and pockmarks of a passive margin vs. a serpentinite mud volcano of an active, non-accretionary, convergent margin. We acknowledge the support from the PES project - Pockmarks and fluid seepage in the Estremadura Spur: implications for regional geology, biology, and petroleum systems (PTDC/GEOFIQ/5162/2014) financed by the Portuguese Foundation for Science and Technology (FCT).

An Insight into Flotation Chemistry of Pyrite with Isomeric Xanthates: A Combined Experimental and Computational Study

Directory of Open Access Journals (Sweden)

Guihong Han

2018-04-01

Full Text Available The flotation chemistry between pyrite and isomeric xanthates (butyl xanthate and isobutyl xanthate was investigated by means of adsorption experiments, surface tension tests, and molecular dynamic simulations in this work. The flotation chemical results were confirmed and further interpreted by quantum chemical calculations. The experiment results demonstrated that the isobutyl xanthate exhibited superior adsorption capacity and surface activity than those of butyl xanthate in flotation chemistry. In addition, molecular dynamic simulations were simultaneously performed in constant number, constant volume and temperature (NVT, and constant number, constant volume, and pressure (NPT ensemble, indicating that the NPT ensemble was more suitable to the flotation system and the isobutyl xanthate was easier to be adsorbed on pyrite surface compared with butyl xanthate during an appropriate range of concentrations. Furthermore, the quantum chemical calculations elucidated that the isobutyl xanthate presented higher reactivity than that of the corresponding butyl xanthate based on the frontier molecular orbital theory of chemical reactivity, which was consistent with experimental and simulation results obtained. This work can provide theoretical guidance for an in-depth study of the flotation chemistry of pyrite with isomeric xanthates.

Savannah River Site environmental report for 1993 summary pamphlet

International Nuclear Information System (INIS)

Karapatakis, L.

1994-01-01

This pamphlet summarizes the impact of 1993 Savannah River Site operations on the environment and the off-site public. It includes an overview of site operations; the basis for radiological and nonradiological monitoring; 1993 radiological releases and the resulting dose to the off-site population; and results of the 1993 nonradiological program. The Savannah River Site Environmental Report for 1993 describes the findings of the environmental monitoring program for 1993. The report contains detailed information about site operations,the environmental monitoring and surveillance programs, monitoring and surveillance results, environmental compliance activities, and special programs. The report is distributed to government officials, members of the US Congress, universities, government facilities, environmental and civic groups, the news media, and interested individuals

Savannah River release: test of the new ARAC capability

International Nuclear Information System (INIS)

Dickerson, M.H.

1977-01-01

Working jointly from opposite sides of the nation Lawrence Livermore Laboratory (LLL) and the Savannah River Laboratory (SRL) quickly assessed the consequences of an early-morning tritium release in May 1974 from the Savannah River Plant, in South Carolina. Measurements confirmed the accuracy of the LLL predictions. Due to the small quantity involved and to the release location (well within the plant confines), the release was not dangerous to the public. The emergency provided a dramatic test of procedures and capabilities of the new Atmospheric Release Advisory Capability (ARAC) center at Livermore, which was not yet operational, demonstrating the capacity for quick response, and the feasibility of real-time data acquisition and transmittal across the continent

Woody encroachment over 70 years in South African savannahs: overgrazing, global change or extinction aftershock?

Science.gov (United States)

Stevens, Nicola; Erasmus, B F N; Archibald, S; Bond, W J

2016-09-19

Woody encroachment in 'open' biomes like grasslands and savannahs is occurring globally. Both local and global drivers, including elevated CO2, have been implicated in these increases. The relative importance of different processes is unresolved as there are few multi-site, multi-land-use evaluations of woody plant encroachment. We measured 70 years of woody cover changes over a 1020 km(2) area covering four land uses (commercial ranching, conservation with elephants, conservation without elephants and communal rangelands) across a rainfall gradient in South African savannahs. Different directions of woody cover change would be expected for each different land use, unless a global factor is causing the increases. Woody cover change was measured between 1940 and 2010 using the aerial photo record. Detection of woody cover from each aerial photograph was automated using eCognitions' Object-based image analysis (OBIA). Woody cover doubled in all land uses across the rainfall gradient, except in conservation areas with elephants in low-rainfall savannahs. Woody cover in 2010 in low-rainfall savannahs frequently exceeded the maximum woody cover threshold predicted for African savannahs. The results indicate that a global factor, of which elevated CO2 is the likely candidate, may be driving encroachment. Elephants in low-rainfall savannahs prevent encroachment and localized megafaunal extinction is a probable additional cause of encroachment.This article is part of the themed issue 'Tropical grassy biomes: linking ecology, human use and conservation'. © 2016 The Author(s).

Savannah River site environmental report for 1996

Energy Technology Data Exchange (ETDEWEB)

Arnett, M.; Mamatey, A. [eds.

1998-12-31

The mission at the Savannah River Site (SRS) has changed from the production of nuclear weapons materials for national defense to the management of site-generated waste, restoration of the surrounding environment, and the development of industry in and around the site. However, SRS-through its prime operating contractor, Westinghouse Savannah River Company (WSRC)-continues to maintain a comprehensive environmental monitoring program. In 1996, effluent monitoring and environmental surveillance were conducted within a 31,000-square-mile area in and around SRS that includes neighboring cities, towns, and counties in Georgia and South Carolina and extends up to 100 miles from the site. Though the environmental monitoring program was streamlined in 1996-to improve its cost-effectiveness without compromising data quality or reducing its overall ability to produce critical information-thousands of samples of air, surface water, groundwater, food products, drinking water, wildlife, rainwater, soil, sediment, and vegetation were collected and analyzed for radioactive and nonradioactive contaminants.

Savannah River site environmental report for 1996

International Nuclear Information System (INIS)

Arnett, M.; Mamatey, A.

1998-01-01

The mission at the Savannah River Site (SRS) has changed from the production of nuclear weapons materials for national defense to the management of site-generated waste, restoration of the surrounding environment, and the development of industry in and around the site. However, SRS-through its prime operating contractor, Westinghouse Savannah River Company (WSRC)-continues to maintain a comprehensive environmental monitoring program. In 1996, effluent monitoring and environmental surveillance were conducted within a 31,000-square-mile area in and around SRS that includes neighboring cities, towns, and counties in Georgia and South Carolina and extends up to 100 miles from the site. Though the environmental monitoring program was streamlined in 1996-to improve its cost-effectiveness without compromising data quality or reducing its overall ability to produce critical information-thousands of samples of air, surface water, groundwater, food products, drinking water, wildlife, rainwater, soil, sediment, and vegetation were collected and analyzed for radioactive and nonradioactive contaminants

Savannah River Site Environmental Report for 1998 Summary

International Nuclear Information System (INIS)

Arnett, M.

1999-01-01

This pamphlet gives a brief overview of the Savannah River Site and its activities, summarizes the impact of 1998 site operations on the environment and the public, and provides a brief explanation of radiation and dose

Effect of capping ligands on the optical properties and electronic energies of iron pyrite FeS{sub 2} nanocrystals and solid thin films

Energy Technology Data Exchange (ETDEWEB)

Zhai, Guangmei, E-mail: zhaiguangmei@tyut.edu.cn [Key Laboratory of Interface Science and Engineering in Advanced Materials of Ministry of Education of the People' s Republic of China, Research Centre of Advanced Materials Science and Technology of Taiyuan University of Technology, Taiyuan, Shanxi 030024 (China); Jiangsu Key Laboratory for Solar Cell Materials and Technology, Changzhou University, Changzhou, Jiangsu 213164 (China); State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054 (China); Xie, Rongwei; Wang, Heng; Zhang, Jitao; Yang, Yongzhen; Wang, Hua; Li, Xuemin [Key Laboratory of Interface Science and Engineering in Advanced Materials of Ministry of Education of the People' s Republic of China, Research Centre of Advanced Materials Science and Technology of Taiyuan University of Technology, Taiyuan, Shanxi 030024 (China); Liu, Xuguang [Key Laboratory of Interface Science and Engineering in Advanced Materials of Ministry of Education of the People' s Republic of China, Research Centre of Advanced Materials Science and Technology of Taiyuan University of Technology, Taiyuan, Shanxi 030024 (China); College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan, Shanxi 030024 (China); Xu, Bingshe [Key Laboratory of Interface Science and Engineering in Advanced Materials of Ministry of Education of the People' s Republic of China, Research Centre of Advanced Materials Science and Technology of Taiyuan University of Technology, Taiyuan, Shanxi 030024 (China)

2016-07-25

In this work, the optical and electronic properties of iron pyrite FeS{sub 2} nanocrystals and solid thin films with various capping ligands were systematically investigated by UV–Vis–NIR absorption spectroscopy, cyclic voltammetry and current density–voltage characteristic measurements. The iron pyrite nanocrystals with various ligands have an indirect band gap of around 1.05 eV and broad absorption spanning into the near-infrared region, exhibiting favorable optical properties for their photovoltaic applications. The electron affinities and ionization potentials of FeS{sub 2} nanocrystals determined through cyclic voltammetry measurements show strong ligand dependence. An energy level shift of up to 190 meV was obtained among the pyrite nanocrystals capped with the ligands employed in this work. The iron pyrite nanocrystal films capped with iodide and 1,2-ethanedithiol exhibit the largest band edge energy shift and conductivity, respectively. Our results not only provide several useful optical and electronic parameters of pyrite nanocrystals for their further use in optoelectronic devices as active layers and/or infrared optical absorption materials, but also highlight the relationship between their surface chemistry and electronic energies. - Highlights: • The energy levels of FeS{sub 2} nanocrystals with various ligands were determined via electrochemical measurements. • The energy levels of FeS{sub 2} nanocrystals showed strong ligand-dependence. • An energy level shift of up to 190 meV was obtained for the pyrite nanocrystals studied in the work. • The conductivities of FeS{sub 2} nanocrystals with different ligands were obtained by current density–voltage measurements.

Tiger Team Assessment of the Savannah River Site

International Nuclear Information System (INIS)

1990-06-01

This draft document contains findings identified during the Tiger Team Compliance Assessment of the US Department of Energy Savannah River Site (SRS), located in three counties (Aiken, Barnwell and Allendale), South Carolina. The Assessment was directed by the Department's Office of the Assistant Secretary for Environment, Safety, and Health (ES ampersand H) and was conducted from January 29 to March 23, 1990. The Savannah River Site Tiger Team Compliance Assessment was broad in scope covering the Environment, Safety and Health, and Management areas and was designed to determine the site's compliance with applicable Federal (including DOE), state, and local regulations and requirements. The scope of the Environmental assessment was sitewide while the Safety and Health assessments included site operating facilities (except reactors), and the sitewide elements of Aviation Safety, Emergency Preparedness, Medical Services, and Packaging and Transportation

Surface Chemical Characterisation of Pyrite Exposed to Acidithiobacillus ferrooxidans and Associated Extracellular Polymeric Substances

Directory of Open Access Journals (Sweden)

Sian M. La Vars

2018-03-01

Full Text Available A. ferrooxidans and their metabolic products have previously been explored as a viable alternative depressant of pyrite for froth flotation; however, the mechanism by which separation is achieved is not completely understood. Scanning electron microscopy (SEM, photoemission electron microscopy (PEEM, time-of-flight secondary ion mass spectrometry (ToF-SIMS and captive bubble contact angle measurements have been used to examine the surface physicochemical properties of pyrite upon exposure to A. ferrooxidans grown in HH medium at pH 1.8. C K-edge near edge X-ray absorption fine structure (NEXAFS spectra collected from PEEM images indicate hydrophilic lipids, fatty acids and biopolymers are formed at the mineral surface during early exposure. After 168 h, the spectra indicate a shift towards protein and DNA, corresponding to an increase in cell population and biofilm formation on the surface, as observed by SEM. The Fe L-edge NEXAFS show gradual oxidation of the mineral surface from Fe(II sulfide to Fe(III oxyhydroxides. The oxidation of the iron species at the pyrite surface is accelerated in the presence of A. ferrooxidans and extracellular polymeric substances (EPS as compared to HH medium controls. The surface chemical changes induced by the interaction with A. ferrooxidans show a significant decrease in surface hydrophobicity within the first 2 h of exposure. The implications of these findings are the potential use of EPS produced during early attachment of A. ferrooxidans, as a depressant for bioflotation.

Soil pollution by a pyrite mine spill in Spain: evolution in time

International Nuclear Information System (INIS)

Aguilar, J.; Dorronsoro, C.; Fernandez, E.; Fernandez, J.; Garcia, I.; Martin, F.; Simon, M.

2004-01-01

Soil pollution was studied after the spill of the Aznalcollar pyrite mine between 1998 and 2001, analyzing As, Zn, Cd, Cu and Pb both in total concentrations as well as in soluble and bioavailable forms. The main remediation measures were: clean-up of the tailings and polluted soils, plus application of amendment materials (liming). The results indicate that, after three years, 50-70% of the acidic soils and 25-30% of the basic soils are still highly polluted in total arsenic. The limit of 0.04 mg kg -1 for water-soluble arsenic is exceeded in 15-20% of all soils. The EDTA-extractable arsenic (bioavailable) exceeds the limit of 2 mg kg -1 only in the acidic sectors. After clean-up, the homogenization of the upper 20-25 cm of the soils appears to be the most recommended measure in the reduction of pollution. - Capsule: Remediation measures carried out after the Aznalcollar pyrite mine spill were effective in the reduction of the pollution, although three years after the accident many areas are still polluted by As

Mammals of the Savannah River Site

International Nuclear Information System (INIS)

Cothran, E.G.; Smith, M.H.; Wolff, J.O.; Gentry, J.B.

1991-01-01

This book is designed to be used as a field guide, reference book, bibliography, and introduction to the basic biology and ecology of the 54 mammal species that currently or potentially exist on or near the Savannah River Site (SRS). For 50 of these species, we present basic descriptions, distinguishing morphological features, distribution and habitat preferences, food habits, reproductive biology, social behavior, ecological relationships with other species, and economic importance to man. For those species that have been studied on the SRS, we summarize the results of these studies. Keys and illustrations are provided for whole body and skull identification. A selected glossary defines technical terminology. Illustrations of tracks of the more common larger mammals will assist in field identifications. We also summarize the results of two major long-term SRS studies, ''The Forbearer Census'' and ''White-tailed Deer Studies''. A cross-indexed list of over 300 SRS publications on mammals classifies each publication by 23 categories such as habitat, reproduction, genetics, etc., and also for each mammal species. The 149 Master's theses and Ph.D. dissertations that have been conducted at the Savannah River Ecology Laboratory are provided as additional references

Mammals of the Savannah River Site

Energy Technology Data Exchange (ETDEWEB)

Cothran, E.G.; Smith, M.H.; Wolff, J.O.; Gentry, J.B.

1991-01-01

This book is designed to be used as a field guide, reference book, bibliography, and introduction to the basic biology and ecology of the 54 mammal species that currently or potentially exist on or near the Savannah River Site (SRS). For 50 of these species, we present basic descriptions, distinguishing morphological features, distribution and habitat preferences, food habits, reproductive biology, social behavior, ecological relationships with other species, and economic importance to man. For those species that have been studied on the SRS, we summarize the results of these studies. Keys and illustrations are provided for whole body and skull identification. A selected glossary defines technical terminology. Illustrations of tracks of the more common larger mammals will assist in field identifications. We also summarize the results of two major long-term SRS studies, The Forbearer Census'' and White-tailed Deer Studies''. A cross-indexed list of over 300 SRS publications on mammals classifies each publication by 23 categories such as habitat, reproduction, genetics, etc., and also for each mammal species. The 149 Master's theses and Ph.D. dissertations that have been conducted at the Savannah River Ecology Laboratory are provided as additional references.

Mammals of the Savannah River Site

Energy Technology Data Exchange (ETDEWEB)

Cothran, E.G.; Smith, M.H.; Wolff, J.O.; Gentry, J.B.

1991-12-31

This book is designed to be used as a field guide, reference book, bibliography, and introduction to the basic biology and ecology of the 54 mammal species that currently or potentially exist on or near the Savannah River Site (SRS). For 50 of these species, we present basic descriptions, distinguishing morphological features, distribution and habitat preferences, food habits, reproductive biology, social behavior, ecological relationships with other species, and economic importance to man. For those species that have been studied on the SRS, we summarize the results of these studies. Keys and illustrations are provided for whole body and skull identification. A selected glossary defines technical terminology. Illustrations of tracks of the more common larger mammals will assist in field identifications. We also summarize the results of two major long-term SRS studies, ``The Forbearer Census`` and ``White-tailed Deer Studies``. A cross-indexed list of over 300 SRS publications on mammals classifies each publication by 23 categories such as habitat, reproduction, genetics, etc., and also for each mammal species. The 149 Master`s theses and Ph.D. dissertations that have been conducted at the Savannah River Ecology Laboratory are provided as additional references.

Distribution and origin of authigenic smectite clays in Cape Roberts Project Core 3, Victoria Land Basin, Antarctica

Science.gov (United States)

Priestas, A.W.; Wise, S.W.

2007-01-01

Of some 800 m of lower Oligocene marine sediments cored continuously from the seafloor in the Victoria Land Basin of Antarctica at Cape Roberts Site CRP-3, the lower 500 m exhibit authigenic smectite clay coats on shallow-water sandstone grains. A scanning electron microscope/EDS study of 46 fracture sections confirms that the distribution of the clay coats through the unit is not uniform or evenly distributed, but rather varies with depth, original porosity, and the kinds and abundance of source materials. Our results suggest that smectite emplacement resulted from in-situ, low-temperature burial diagenesis rather than hydrothermal or fault-focused thermobaric fluids.

Production of hydroxyl radicals from abiotic oxidation of pyrite by oxygen under circumneutral conditions in the presence of low-molecular-weight organic acids

Science.gov (United States)

Zhang, Peng; Yuan, Songhu

2017-12-01

Besides acidic environments, pyrite oxidation also occurs in circumneutral environments, such as well-buffered marine and estuarine sediments and salt marshes where low-molecular-weight organic acids (LMWOAs) (e.g., citrate and oxalate) prevail. However, the production of hydroxyl radicals (radOH) from pyrite oxidation by oxygen (O2) in these circumneutral environments is poorly understood. In this study, radOH production was measured during the abiotic oxidation of pyrite by O2 under circumneutral conditions. A pyrite suspension (50 g/L pyrite) that was buffered at pH 6-8 was exposed to air for oxygenation in the dark. Benzoate (20 mM) was added into the suspension to trap radOH. At pH 7, the cumulative radOH reached 7.5 μM within 420 min in the absence of LMWOAs, whereas it increased to 14.8, 12 and 11.2 μM in the presence of 1 mM ethylenediaminotetraacetate, citrate and oxalate, respectively. When the citrate concentration, which serves as a LMWOAs model, was increased from 0.5 to 5 mM, the cumulative radOH increased from 10.3 to 27.3 μM within 420 min at pH 7. With the decrease in pH from 8 to 6, the cumulative radOH increased from 2.1 to 23.3 μM in the absence of LMWOAs, but it increased from 8.8 to 134.9 μM in the presence of 3 mM citrate. The presence of LMWOAs enhanced the radOH production from pyrite oxidation under circumneutral conditions. In the absence of LMOWAs, radOH is produced mostly from the oxidation of adsorbed Fe(II) by O2. In the presence of citrate, radOH production is attributed mainly to the oxidation of Fe(II)-citrate- by O2 and secondarily to the oxidation of H2O on surface-sulfur defects. The acceleration of pyrite oxidation by Fe(III)-citrate increases radOH production. Fe(II)-citrate- is generated mainly from the complexation of adsorbed Fe(II) by citrate and the reduction of Fe(III)-citrate, and the generation is suppressed by the oxidation of adsorbed Fe(II). Fe(III)-citrate is generated predominantly from Fe

Audit of the Uranium Solidification Facility at the Savannah River Site

International Nuclear Information System (INIS)

1994-01-01

In the late 1980s, DOE decided to construct a Uranium Solidification Facility at the Savannah River Site to process liquid uranyl nitrate into powder. Since the need for weapons materials has been reduced, an audit was conducted to assess the need for this facility. The audit disclosed that DOE continued to construct the facility, because DOE's procedures did not ensure that projects of this type were periodically reassessed when significant program changes occurred. The audit identified more economical alternatives for processing existing quantities of liquid uranyl nitrate at the Savannah River Site

Striped Bass Spawning in Non-Estuarine Portions of the Savannah River

Energy Technology Data Exchange (ETDEWEB)

Martin, D.; Paller, M.

2007-04-17

Historically, the estuarine portions of the Savannah River have been considered to be the only portion of the river in which significant amounts of striped bass (Morone saxatilis) spawning normally occur. A reexamination of data from 1983 through 1985 shows a region between River Kilometers 144 and 253 where significant numbers of striped bass eggs and larvae occur with estimated total egg production near that currently produced in the estuarine reaches. It appears possible that there are two separate spawning populations of striped bass in the Savannah River.

Westinghouse Savannah River Company (WSRC) approach to nuclear facility maintenance

International Nuclear Information System (INIS)

Harrison, D.W.

1991-01-01

The Savannah River Site (SRS) in South Carolina is a 300+ square mile facility owned by the US Department of Energy (DOE) and operated by Westinghouse Savannah River Company (WSRC), the prime contractor; Bechtel Savannah River, Incorporated (BSRI) is a major subcontractor. The site has used all of the five nuclear reactors and it has the necessary nuclear materials processing facilities, as well as waste management and research facilities. The site has produced materials for the US nuclear arsenal and various isotopes for use in space research and nuclear medicine for more than 30 years. In 1989, WSRC took over as prime contractor, replacing E.I. du Pont de Nemours and Company. At this time, a concentrated effort began to more closely align the operating standards of this site with those accepted by the commercial nuclear industry of the United States. Generally, this meant acceptance of standards of the Institute of Nuclear Power Operations (INPO) for nuclear-related facilities at the site. The subject of this paper is maintenance of nuclear facilities and, therefore, excludes discussion of the maintenance of non-nuclear facilities and equipment

Litology and possibilities of comprehensive using modern alluvium Dnieper

Directory of Open Access Journals (Sweden)

Ivanchenko V. V.

2015-09-01

Full Text Available Studied mineralogy of bottom sediments of the Lower Dnieper. The identified minerals zirconium, rare earths (monazite, titanium, grenades, etc., is finding gold, silver and diamonds. In addition to typical detrital grains tumors installed component authigenic sediment - pyrite, marcasite, carbonates, goethite. The observed constant presence of particles of sludge, slag, refractory, metallurgical graphite, spinel, glass and ore balls - indicators of anthropogenic pollution. Search interest with gold, zircon, ilmenite, rutile, monazite, diamond. When passing extraction can be used light fraction minerals: quartz, kaolinite and other clay minerals and mushlevyy detritus and limestone.

Environmental audit of the Savannah River Ecology Laboratory (SREL)

Energy Technology Data Exchange (ETDEWEB)

1993-09-01

This report documents the results of the environmental audit conducted at the Savannah River Ecology Laboratory (SREL) at the Savannah River Site (SRS), principally in Aiken and Barnwell Counties, South Carolina. The audit was conducted by the US Department of Energy`s (DOE`s), Office of Environmental Audit (EH-24), beginning September 13, 1993, and ending September 23, 1993. The scope of the audit at SREL was comprehensive, addressing environmental activities in the technical areas of air; surface water/drinking water; groundwater/soil, sediment, and biota; waste management; toxic and chemical materials; inactive Waste sites; radiation; quality assurance; and environmental management. Specifically assessed was the compliance of SREL operations and activities with Federal, state, and local regulations; DOE Orders; and best management practices.

The Savannah River Site's Groundwater Monitoring Program

Energy Technology Data Exchange (ETDEWEB)

1989-01-01

The Environmental Monitoring Section of the Environmental and Health Protection (EHP) Department administers the Savannah River Site's Groundwater Monitoring Program. During fourth quarter 1989 (October--December), EHP conducted routine sampling of monitoring wells and drinking water locations. EHP collected the drinking water samples from Savannah River Site (SRS) drinking water systems supplied by wells. EHP established two sets of flagging criteria in 1986 to assist in the management of sample results. The flagging criteria aid personnel in sample scheduling, interpretation of data, and trend identification. An explanation of flagging criteria for the fourth quarter is presented in the Flagging Criteria section of this document. All analytical results from fourth quarter 1989 are listed in this report, which is distributed to all waste-site custodians.

Environmental audit of the Savannah River Ecology Laboratory (SREL)

International Nuclear Information System (INIS)

1993-09-01

This report documents the results of the environmental audit conducted at the Savannah River Ecology Laboratory (SREL) at the Savannah River Site (SRS), principally in Aiken and Barnwell Counties, South Carolina. The audit was conducted by the US Department of Energy's (DOE's), Office of Environmental Audit (EH-24), beginning September 13, 1993, and ending September 23, 1993. The scope of the audit at SREL was comprehensive, addressing environmental activities in the technical areas of air; surface water/drinking water; groundwater/soil, sediment, and biota; waste management; toxic and chemical materials; inactive Waste sites; radiation; quality assurance; and environmental management. Specifically assessed was the compliance of SREL operations and activities with Federal, state, and local regulations; DOE Orders; and best management practices

Savannah River Region: Transition between the Gulf and Atlantic Coastal Plains. Proceedings

Energy Technology Data Exchange (ETDEWEB)

Zullo, V.A.; Harris, W.B.; Price, V. [eds.

1990-12-31

The focus of the this conference of Coastal Plains geologists was on the Savannah River region of Georgia and South Carolina, and particularly on the geology of the US Department of Energy`s 300 square mile Savannah River Site (SRS) in western South Carolina. Current geological studies indicate that the Mesozoic-Cenozoic section in the Savannah River region is transitional between that of the Gulf Coastal Plain to the southwest and that of the Atlantic Coastal Plain to the northeast. With the transitional aspect of the region as its theme, the first session was devoted to overviews of Cretaceous and Paleogene geology in the Gulf and Atlantic Coastal Plains. Succeeding presentations and resulting discussions dealt with more specific problems in structural, lithostratigraphic, hydrological, biostratigraphic, and cyclostratigraphic analysis, and of correlation to standard stratigraphic frameworks. For these conference proceedings, individual papers have been processed separately for the Energy Data Base.

Environmental radiation in coal and soil samples from Savannah area (Chatham County, GA)

International Nuclear Information System (INIS)

Hongo, D.; Ghuman, G.S.; Chandra, K.

1997-01-01

Radiation measurements were made in coal and fly ash samples from Savannah Electric ampersand Power Company (SEPCO) plant on the Savannah River and the soil core samples from three sites along the flow gradient of Savannah State University Campus Creek. The objective of this study was to determine the magnitude of natural radiation due to radon and potassium in the Savannah area and possible effect of external factors such as the operations at Savannah River Site (SRS). The instrument used for this purpose was Geiger Counter Model 500 (Tennelec/Nucleus, Inc.) which was standardized with known samples of Sr-90 (0.1 μCi t 1/2 = 28.6 yrs., beta radiation) and Co-60 (1.0 μCi t 1/2 = 5.27 yrs., gamma radiation). Beta and gamma radiations in the samples were differentiated with the help of polyethylene and lead absorbers. Results showed quite low radioactivity in bituminous coal from SEPCO plant and it reduced by a factor of 0.5 and 0.25 in fly ash and weathered fly ash, respectively. Radioactivity of soil samples was slightly greater in the top soil (0-3 cm) of two sites and it decreased markedly with depth (20 cm). Site III soil samples containing lime shells had a negligible radioactivity because carbonate rocks developed from calcareous skeletal matter have low radioactivity from their beginning. Radioactivity appeared to be mainly associated with the fine textured top soil of two sites (high clay content) and it exhibited very little leaching downward into lower layers. Clay particles with greater radioactivity, are formed from the decomposition of feldspars and micas which contain a large fraction of earth's potassium fraction. Measurements with the use of absorbers indicated that the observed radiation in all the samples was mainly due to the gamma rays. A comparison with the radioactivity in coal dust and fly ash samples from SRS revealed that the Savannah samples contained extremely low radiation, which may be due only to the natural sources

The Savannah River Site's Groundwater Monitoring Program

International Nuclear Information System (INIS)

1992-01-01

This report summarizes the Savannah River Site (SRS) groundwater monitoring program conducted during the first quarter of 1992. It includes the analytical data, field data, data review, quality control, and other documentation for this program; provides a record of the program's activities; and serves as an official document of the analytical results

Production of pyrite nanoparticles using high energy planetary ball milling for sonocatalytic degradation of sulfasalazine.

Science.gov (United States)

Khataee, Alireza; Fathinia, Siavash; Fathinia, Mehrangiz

2017-01-01

Sonocatalytic performance of pyrite nanoparticles was evaluated by the degradation of sulfasalazine (SSZ). Pyrite nanoparticles were produced via a high energy mechanical ball milling (MBM) in different processing time from 2h to 6h, in the constant milling speed of 320rpm. X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FT-IR) analysis and Brunauer-Emmett-Teller (BET) confirmed the production of pyrite nanoparticles during 6h of ball milling with the average size distribution of 20-80nm. The effects of various operational parameters including pH value, catalyst amount (mg/L), SSZ concentration (mg/L), ultrasonic frequency (kHz) and reaction time on the SSZ removal efficiency were examined. The obtained results showed that the maximum removal efficiency of 97.00% was obtained at pH value of 4, catalyst dosage of 0.5g/L, SSZ concentration of 10mg/L and reaction time of 30min. Experimental results demonstrated that the kinetic of the degradation process can be demonstrated using Langmuir-Hinshelwood (L-H) kinetic model. The effect of different inorganic ions such as Cl - , CO 3 2- and SO 4 2- was investigated on the L-H reaction rate (k r ) and adsorption (K s ) constants. Results showed that the presence of the mentioned ions significantly influenced the L-H constants. The impact of ethanol as a OH radical scavenger and some enhancers including H 2 O 2 and K 2 S 2 O 8 was investigated on the SSZ removal efficiency. Accordingly, the presence of ethanol suppressed SSZ degradation due to the quenching of OH radicals and the addition of K 2 S 2 O 8 and H 2 O 2 increased the SSZ removal efficiency, due to the formation of SO 4 - and additional OH radicals, respectively. Under the identical conditions of operating parameters, pyrite nanoparticles maintained their catalytic activity during four consecutive runs. Copyright © 2016 Elsevier B.V. All rights reserved.

Review of the SQUG type seismic program at Savannah River Site

International Nuclear Information System (INIS)

Bitner, J.L.; Lin, C.W.; Anderson, N.R.; Bezler, P.

1991-01-01

The production reactors at Savannah River were shut down in 1988 because of questions about their safety. One question is whether they can withstand earthquakes. To answer the earthquake question, the site operator (Westinghouse Savannah River Company) developed a program to evaluate the capability of the safety systems in the K, L, and P reactors to function during and after an earthquake, and to upgrade them if necessary. The seismic program for Savannah River relies heavily on the Generic Implementation Procedure (GIP) developed by the Seismic qualification Utility Group. The GIP was originally developed for application to over 65 commercial power reactors throughout the U.S. It has been thoroughly reviewed by the U.S. Nuclear Regulatory Commission. The objectives of the ISWRT (Independent Seismic Walkdown Review Team) review were to: evaluate the program and evaluate its execution. The first objective was accomplished using an in-office review of the program. The second objective was accomplished using an in-office review and in-plant walkdown of selected safety systems. The ISWRT review and walkdown are summarized in this paper

A combined kinetic and diffusion model for pyrite oxidation in tailings - a change in controls with time

International Nuclear Information System (INIS)

Elberling, B.; Nicholson, R.V.; Scharer, J.M.

1994-01-01

Acidic drainage from the oxidation of mine tailing wastes is an important environmental problem. The purpose of this paper is to develop a model (1) to simulate the rate of oxidation of pyrite over time, (2) to verify the importance of chemical kinetic control and diffusion control on the oxidation rate with time and, (3) to evaluate the sensitivity of the model to critical parameters of the tailings, such as grain size, pyrite content and the effective diffusion coefficient. The source code comprises four main modules including parameter allocation (kinetics, transport), sulphide oxidation (shrinking particle), oxygen transport and pyrite mass balance. The results show that high oxidation rates are observed in the initial time after tailings deposition. During this initial period of high rates, an apparent shift occurs from kinetic to diffusional control over a period of time that depends on the composition and properties of the tailings. Based on the simulation results, it is evident that the overall rate of oxidation after a few years will be controlled dominantly by the diffusion of oxygen rather than by biological or non-biological kinetics in the tailings

Land Use Baseline Report Savannah River Site

International Nuclear Information System (INIS)

Noah, J.C.

1995-01-01

This document is to serve as a resource for Savannah River Site managers, planners, and SRS stakeholders by providing a general description of the site and land-use factors important to future use decisions and plans. The intent of this document is to be comprehensive in its review of SRS and the surrounding area

Land Use Baseline Report Savannah River Site

Energy Technology Data Exchange (ETDEWEB)

Noah, J.C.

1995-06-29

This document is to serve as a resource for Savannah River Site managers, planners, and SRS stakeholders by providing a general description of the site and land-use factors important to future use decisions and plans. The intent of this document is to be comprehensive in its review of SRS and the surrounding area.

Facility siting as a decision process at the Savannah River Site

International Nuclear Information System (INIS)

Wike, L.D.

1995-01-01

Site selection for new facilities at Savannah River Site (SRS) historically has been a process dependent only upon specific requirements of the facility. While this approach is normally well suited to engineering and operational concerns, it can have serious deficiencies in the modern era of regulatory oversight and compliance requirements. There are many issues related to the site selection for a facility that are not directly related to engineering or operational requirements; such environmental concerns can cause large schedule delays and budget impact,s thereby slowing or stopping the progress of a project. Some of the many concerns in locating a facility include: waste site avoidance, National Environmental Policy Act requirements, Clean Water Act, Clean Air Act, wetlands conservation, US Army Corps of Engineers considerations, US Fish and Wildlife Service statutes including threatened and endangered species issues, and State of South Carolina regulations, especially those of the Department of Health and Environmental Control. In addition, there are SRS restrictions on research areas set aside for National Environmental Research Park (NERP), Savannah River Ecology Laboratory, Savannah River Forest Station, University of South Carolina Institute of Archaeology and Anthropology, Southeastern Forest Experimental Station, and Savannah River Technology Center (SRTC) programs. As with facility operational needs, all of these siting considerations do not have equal importance. The purpose of this document is to review recent site selection exercises conducted for a variety of proposed facilities, develop the logic and basis for the methods employed, and standardize the process and terminology for future site selection efforts

Robotics at Savannah River site: activity report

International Nuclear Information System (INIS)

Byrd, J.S.

1984-09-01

The objectives of the Robotics Technology Group at the Savannah River Laboratory are to employ modern industrial robots and to develop unique automation and robotic systems to enhance process operations at the Savannah River site (SRP and SRL). The incentives are to improve safety, reduce personnel radiation exposure, improve product quality and productivity, and to reduce operating costs. During the past year robotic systems have been installed to fill chemical dilution vials in a SRP laboratory at 772-F and remove radioactive waste materials in the SRL Californium Production Facility at 773-A. A robotic system to lubricate an extrusion press has been developed and demonstrated in the SRL robotics laboratory and is scheduled for installation at the 321-M fuel fabrication area. A mobile robot was employed by SRP for a radiation monitoring task at a waste tank top in H-Area. Several other robots are installed in the SRL robotics laboratories and application development programs are underway. The status of these applications is presented in this report

Authigenic oxide Neodymium Isotopic composition as a proxy of seawater: applying multivariate statistical analyses.

Science.gov (United States)

McKinley, C. C.; Scudder, R.; Thomas, D. J.

2016-12-01

The Neodymium Isotopic composition (Nd IC) of oxide coatings has been applied as a tracer of water mass composition and used to address fundamental questions about past ocean conditions. The leached authigenic oxide coating from marine sediment is widely assumed to reflect the dissolved trace metal composition of the bottom water interacting with sediment at the seafloor. However, recent studies have shown that readily reducible sediment components, in addition to trace metal fluxes from the pore water, are incorporated into the bottom water, influencing the trace metal composition of leached oxide coatings. This challenges the prevailing application of the authigenic oxide Nd IC as a proxy of seawater composition. Therefore, it is important to identify the component end-members that create sediments of different lithology and determine if, or how they might contribute to the Nd IC of oxide coatings. To investigate lithologic influence on the results of sequential leaching, we selected two sites with complete bulk sediment statistical characterization. Site U1370 in the South Pacific Gyre, is predominantly composed of Rhyolite ( 60%) and has a distinguishable ( 10%) Fe-Mn Oxyhydroxide component (Dunlea et al., 2015). Site 1149 near the Izu-Bonin-Arc is predominantly composed of dispersed ash ( 20-50%) and eolian dust from Asia ( 50-80%) (Scudder et al., 2014). We perform a two-step leaching procedure: a 14 mL of 0.02 M hydroxylamine hydrochloride (HH) in 20% acetic acid buffered to a pH 4 for one hour, targeting metals bound to Fe- and Mn- oxides fractions, and a second HH leach for 12 hours, designed to remove any remaining oxides from the residual component. We analyze all three resulting fractions for a large suite of major, trace and rare earth elements, a sub-set of the samples are also analyzed for Nd IC. We use multivariate statistical analyses of the resulting geochemical data to identify how each component of the sediment partitions across the sequential

Savannah River Plant californium-252 Shuffler electronics manual

International Nuclear Information System (INIS)

Bourret, S.C.; Crane, T.W.; Eccleston, G.W.; Gallegos, E.A.; Garcia, D.L.

1980-03-01

Detailed information is presented in this report, an electronics manual for the Savannah River Plant Shuffler, about the electronics associated with the various control and data acquisition functions of the Shuffler subsystems. Circuit diagrams, interconnection information, and details about computer control and programming are included

The Savannah River Site's groundwater monitoring program

International Nuclear Information System (INIS)

1991-01-01

This report summarizes the Savannah River Site (SRS) groundwater monitoring program conducted by EPD/EMS in the first quarter of 1991. In includes the analytical data, field data, data review, quality control, and other documentation for this program, provides a record of the program's activities and rationale, and serves as an official document of the analytical results

Savannah River Laboratory monthly report: 238Pu fuel form processes

International Nuclear Information System (INIS)

1976-01-01

Progress in the Savannah River 238 Pu Fuel Form Program is discussed. Goals of the Savannah River Laboratory (SRL) program are to provide technical support for the transfer of the 238 Pu fuel form fabrication operations from Mound Laboratory to new facilities being built at the Savannah River Plant (SRP), to provide the technical basis for 238 Pu scrap recovery at SRP, and to assist in sustaining plant operations. During the period it was found that the density of hot-pressed 238 PuO 2 pellets decreased as the particle size of ball-milled powder decreased;the surface area of calcined 238 PuO 2 powder increased with increasing precipitation temperature and may be related to the variation in ball-milling response observed among different H Area B-Line batches; calcined PuO 2 produced by Pu(III) reverse-strike precipitation was directly fabricated into a pellet without ball milling, slugging, or sharding. The pellet had good appearance with acceptable density and dimensional stability, and heat transfer measurements and calculations showed that the use of hollow aluminum sleeves in the plutonium fuel fabrication (PuFF) storage vault reduced the temperature of shipping cans to 170 0 C and will reduce the temperature at the center of pure plutonium oxide (PPO) spheres to 580 0 C

Future concepts of pyrometallurgical operations at the Savannah River Plant

International Nuclear Information System (INIS)

Gray, L.W.; Orth, D.A.; Augsburger, S.T.

1986-01-01

For more than three decades, the Savannah River Plant has used the principles of extractive metallurgy for the winning of plutonium from irradiated reactor targets, reactor fuels, and unirradiated scrap and residues. Realizing that at some time in the future the aging facilities at SRP will come to the end of their useful life, the Savannah River Laboratory is assessing the permutations of the various hydro-, pyro-, and electrometallurgy unit operations that could be combined to yield a complete process. Preliminary evaluation suggests that a combination of cation exchange, oxalate precipitation, calcination, hydrofluorination, and calcium reduction would be a reasonable combination of unit operations for Savannah River to use. Several different combinations of process steps offer about the same space requirements when all recycle loops for a complete process are included; each of these unit operations has an adequate technical basis. No single process route appears to offer unique opportunities for technological improvements that can reduce capital and operating costs below those of the suggested route. A group of other alternatives might be promoted to the favored group following sufficient technical development. Research plans are being formulated to determine which, if any, of the alternatives should be promoted to the favored group

Software quality assurance (SQA) for Savannah River reactors

Energy Technology Data Exchange (ETDEWEB)

Schaumann, C.M.

1990-01-01

Over the last 25 years, the Savannah River Site (SRS) has developed a strong Software Quality Assurance (SQA) program. It provides the information and management controls required of a high quality auditable system. The SRS SQA program provides the framework to meet the requirements in increasing regulation.

Photoactive thin film semiconducting iron pyrite prepared by sulfurization of iron oxides

Energy Technology Data Exchange (ETDEWEB)

Smestad, G.; Ennaoui, A.; Fiechter, S.; Tributsch, H.; Hofmann, W.K.; Birkholz, M. (Hahn-Meitner-Institut Berlin GmbH (Germany, F.R.). Abt. Solare Energetik Hahn-Meitner-Institut Berlin GmbH (Germany, F.R.). Abt. Materialforschung); Kautek, W. (Bundesanstalt fuer Materialforschung und -pruefung, Berlin (Germany, F.R.))

1990-03-01

Photoactive iron pyrite (FeS{sub 2}) thin film layers have been synthesized by a simple method involving the reaction of Fe{sub 3}O{sub 4} or Fe{sub 2}O{sub 3} with elemental sulfur. The films were formed on a variety of different substrate materials by converting or sulfurizing iron oxide layers. The subsequent sulfur treatment of the oxide layers consisted of exposure of the films to gaseous sulfur in open or closed ampules at 350degC for 0.5-2 h. The morphology, composition and photoactivity of the films produced were checked using X-ray diffraction, X-ray photoelectron spectroscopy (ESCA), optical absorption, steady state and transient photoconductivity. The best films showed good crystallinity and purity with concurrent photoconductivity and photoelectrochemical response. The ability of this technique to produce photoactive material can be explained by interpretation of the Gibbs ternary phase diagram for the Fe-O-S system, and may be related to the production of photoactive pyrite in nature. A discussion is made as to the future improvement of the solar cell response by proper optimization of geometric and configurational properties. (orig.).

The Savannah River environmental technology field test platform

International Nuclear Information System (INIS)

Rossabi, J.; Riha, B.D.

1995-01-01

The principal goal in the development of new technologies for environmental monitoring and characterization is transferring them to organizations and individuals for use in site assessment and compliance monitoring. The Savannah River technology Center (SRTC) has been developing a program to rigorously field test promising environmental technologies that have not undergone EPA equivalency testing. The infrastructure and staff expertise developed as part of the activities of the Savannah River Integrated Demonstration Program allows field testing of technologies without the difficulties of providing remote field support. By providing a well-characterized site and a well-developed infrastructure, technologies are tested in actual field scenarios to determine their appropriate applications in environmental characterization and monitoring activities. The field tests provide regulatory organizations, potential industrial partners, and potential users with the opportunity to evaluate the technology's performance and its utility for implementation in environmental characterization and monitoring programs. This program has resulted in the successful implementation of several new technologies

Savannah River Site TEP-SET tests uncertainty report

International Nuclear Information System (INIS)

Taylor, D.J.N.

1993-09-01

This document presents a measurement uncertainty analysis for the instruments used for the Phase I, II and III of the Savannah River One-Fourth Linear Scale, One-Sixth Sector, Tank/Muff/Pump (TMP) Separate Effects Tests (SET) Experiment Series. The Idaho National Engineering Laboratory conducted the tests for the Savannah River Site (SRS). The tests represented a range of hydraulic conditions and geometries that bound anticipated Large Break Loss of Coolant Accidents in the SRS reactors. Important hydraulic phenomena were identified from experiments. In addition, code calculations will be benchmarked from these experiments. The experimental system includes the following measurement groups: coolant density; absolute and differential pressures; turbine flowmeters (liquid phase); thermal flowmeters (gas phase); ultrasonic liquid level meters; temperatures; pump torque; pump speed; moderator tank liquid inventory via a load cells measurement; and relative humidity meters. This document also analyzes data acquisition system including the presampling filters as it relates to these measurements

75 FR 53637 - Foreign-Trade Zone 104-Savannah, GA; Application for Reorganization Under Alternative Site Framework

Science.gov (United States)

2010-09-01

... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Docket 51-2010] Foreign-Trade Zone 104--Savannah... to the Foreign-Trade Zones (FTZ) Board (the Board) by the Savannah Airport Commission, grantee of FTZ 104, requesting authority to reorganize the zone under the alternative site [[Page 53638

Agency interaction at the Savannah River Plant under the Endangered Species Act

International Nuclear Information System (INIS)

Mackey, H.E. Jr.

1985-01-01

The 300 square mile Savannah River Plant (SRP) offers a variety of protected habitats for endangered species including the alligator (resident), red-cockaded woodpecker (resident), short-nose sturgeon (migratory), and wood stork (fish-forager). The most recent of these four species to be listed by the US Fish and Wildlife Service (US FWS) is the wood stork. It had been observed prior to 1983 as an infrequent forager in the SRP Savannah River Swamp which adjoins SRP on the south and southwest. In anticipation of its listing as an endangered species, DOE-SR requested in the spring of 1983 that the Savannah River Ecology Laboratory, University of Georgia, conduct field surveys and studies of the nearest colony of wood storks to SRP (the Birdsville colony in north-central Georgia). The objective of these studies was to determine potential effects of the flooding of the Steel Creek swamp area with cooling water from L-Reactor. L-Reactor, which is proposed for restart, has not been operated since 1968. The survey found that wood storks forage in the Steel Creek delta swamp area of the Savannah River at SRP. Based on the numbers of storks at various foraging locations, sites at SRP ranked higher than non-SRP sites during the pre-fledging phase of the colony. Cold flow testing of L-Reactor also demonstrated that foraging sites in the Steel Creek delta would be unavailable during L-Reactor operation because of increased water levels

Soil amendments promote vegetation establishment and control acidity in coal combustion waste

Science.gov (United States)

R.M. Danker; D.C. Adriano; Bon-Jun Koo; C.D. Barton

2003-01-01

The effects of adding various soil amendments and a pyrite oxidation inhibitor to aid in the establishment of vegetation and to reduce acid drainage (AD) from coal fly ash and coal reject (FA + CR*) were assessed in an outdoor mesocosm study. Preliminary greenhouse experiments and field observations at the U.S. Department of Energy's Savannah River Site (SRS)...

Size-Dependent Affinity of Glycine and Its Short Oligomers to Pyrite Surface: A Model for Prebiotic Accumulation of Amino Acid Oligomers on a Mineral Surface

Science.gov (United States)

Afrin, Rehana; Ganbaatar, Narangerel; Aono, Masashi; Cleaves, H. James; Yano, Taka-aki; Hara, Masahiko

2018-01-01

The interaction strength of progressively longer oligomers of glycine, (Gly), di-Gly, tri-Gly, and penta-Gly, with a natural pyrite surface was directly measured using the force mode of an atomic force microscope (AFM). In recent years, selective activation of abiotically formed amino acids on mineral surfaces, especially that of pyrite, has been proposed as an important step in many origins of life scenarios. To investigate such notions, we used AFM-based force measurements to probe possible non-covalent interactions between pyrite and amino acids, starting from the simplest amino acid, Gly. Although Gly itself interacted with the pyrite surface only weakly, progressively larger unbinding forces and binding frequencies were obtained using oligomers from di-Gly to penta-Gly. In addition to an expected increase of the configurational entropy and size-dependent van der Waals force, the increasing number of polar peptide bonds, among others, may be responsible for this observation. The effect of chain length was also investigated by performing similar experiments using l-lysine vs. poly-l-lysine (PLL), and l-glutamic acid vs. poly-l-glutamic acid. The results suggest that longer oligomers/polymers of amino acids can be preferentially adsorbed on pyrite surfaces. PMID:29370126

Enhanced photoresponse of FeS2 films: the role of Marcasite-Pyrite phase junctions

NARCIS (Netherlands)

Wu, L.; Dzade, N.Y.; Gao, L.; Scanlon, D.O.; Öztürk, Z.; Hollingsworth, N.; Weckhuysen, B.M.; Hensen, E.J.M.; De Leeuw, N.H.; Hofmann, J.P.

2016-01-01

The beneficial role of marcasite in iron-sulfide-based photo-electrochemical applications is reported for the first time. A spectacular improvement of the photoresponse observed experimentally for mixed pyrite/marcasite-FeS2 films can be ascribed to the presence of p/m phase junctions at the

Enhanced Photoresponse of FeS2 Films : The Role of Marcasite–Pyrite Phase Junctions

NARCIS (Netherlands)

Wu, Longfei; Dzade, N.Y.; Gao, L.; Scanlon, D. O.; Özturk, Zafer; Hollingsworth, N.; Weckhuysen, B.M.; Hensen, E. J. M.; de Leeuw, Nora H.; Hofmann, J. P.

2016-01-01

The beneficial role of marcasite in iron sulfide-based photo-electrochemical applications is reported for the first time. A spectacular improvement of the photoresponse observed experimentally for mixed pyrite/marcasite-FeS2 films can be ascribed to the presence of p/m phase junctions at the

Soil infiltration bioreactor incorporated with pyrite-based (mixotrophic) denitrification for domestic wastewater treatment.

Science.gov (United States)

Kong, Zhe; Li, Lu; Feng, Chuanping; Chen, Nan; Dong, Shanshan; Hu, Weiwu

2015-01-01

In this study, an integrated two-stage soil infiltration bioreactor incorporated with pyrite-based (mixotrophic) denitrification (SIBPD) was designed for domestic wastewater treatment. Benefited from excellent adsorption ability and water-permeability, soil infiltration could avoid clogging, shorten operating time and lower maintenance cost. Respiration and nitrification were mostly engaged in aerobic stage (AES), while nitrate was majorly removed by pyrite-based mixotrophic denitrification mainly occurred in anaerobic stage (ANS). Fed with synthetic and real wastewater for 120days at 1.5h HRT, SIBPD demonstrated good removal performance showing 87.14% for COD, 92.84% for NH4(+)-N and 82.58% for TP along with 80.72% of nitrate removed by ANS. TN removal efficiency was 83.74% when conducting real wastewater. Compared with sulfur-based process, the effluent pH of SIBPD was maintained at 6.99-7.34 and the highest SO4(2-) concentration was only 64.63mgL(-1). This study revealed a promising and feasible application prospect for on-site domestic wastewater treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Preparation of Metallic Iron Powder from Pyrite Cinder by Carbothermic Reduction and Magnetic Separation

Directory of Open Access Journals (Sweden)

Hongming Long

2016-04-01

Full Text Available The reduction and magnetic separation procedure of pyrite cinder in the presence of a borax additive was performed for the preparation of reduced powder. The effects of borax dosage, reduction temperature, reduction time and grinding fineness were investigated. The results show that when pyrite cinder briquettes with 5% borax were pre-oxidized at 1050 °C for 10 min, and reduced at 1050 °C for 80 min, with the grinding fineness (<0.44 mm passing 81%, the iron recovery was 91.71% and the iron grade of the magnetic concentrate was 92.98%. In addition, the microstructures of the products were analyzed by optical microscope, scanning electron microscope (SEM, and mineralography, and the products were also studied by the X-ray powder diffraction technique (XRD to investigate the mechanism; the results show that the borax additive was approved as a good additive to improve the separation of iron and gangue.

Scrubbing up: multi-scale investigation of woody encroachment in a southern African savannah

OpenAIRE

Marston, Christopher G.; Aplin, Paul; Wilkinson, David M.; Field, Richard; O'Regan, Hannah J.

2017-01-01

Changes in the extent of woody vegetation represent a major conservation question in many savannah systems around the globe. To address the problem of the current lack of broad-scale cost-effective tools for land cover monitoring in complex savannah environments, we use a multi-scale approach to quantifying vegetation change in Kruger National Park (KNP), South Africa. We test whether medium spatial resolution satellite data (Landsat, existing back to the 1970s), which have pixel sizes larger...

Operation Savannah: A Measure of SADF Decline, Resourcefulness ...

African Journals Online (AJOL)

rwarwick

Keywords: Operation Savannah, Border War, Task Force Zulu, SADF. 1960s and .... Post-war re-organisation started with the returning Special Service. Brigade's .... conceivable threat from an African context, along with an enhanced ground ...... up with the war's momentum, kept pushing forces forward, as at Ebo, in an.

The influence of Savannah River discharge and changing SRS cooling water requirements on the potential entrainment of ichthyoplankton at the SRS Savannah River intakes

International Nuclear Information System (INIS)

Paller, M.H.

1992-08-01

Entrainment (i.e., withdrawal of fish larvae and eggs in cooling water) at the SRS Savannah River intakes is greatest when periods of high river water usage coincide with low river dischargeduring the spawning season. American shad and striped bass are the two species of greatest concern because of their recreational and/or commercial importance and because they produce drifting eggs and larvae vulnerable to entrainment. In the mid-reaches of the Savannah River, American shad and striped bass spawn primarily during April and May. An analysis of Savannah River discharge during April and May 1973--1989 indicated the potential for entrainment of 4--18% of the American shad and striped bass larvae and eggs that drifted past the SRS. This analysis assumed the concurrent operation of L-, K-, and P-Reactors. Additional scenarios investigated were: (1) shutting down L- and P-Reactors, and operating K-Reactor with a recycle cooling tower; and (2) shutting down L- and P-Reactors, eliminating minimum flows to Steel Creek, and operating K-Reactor with a recycle cooling tower. The former scenario reduced potential entrainment to 0.7--3.3%, and the latter scenario reduced potential entrainment to 0.20.8%. Thus, the currently favored scenario of operating K-Reactor with a cooling tower and not operating L- and P-Reactors represents a significant lessening of the impact of SRS operations

Worker Alienation and Compensation at the Savannah River Site.

Science.gov (United States)

Ashwood, Loka; Wing, Steve

2016-05-01

Corporations operating U.S. nuclear weapons plants for the federal government began tracking occupational exposures to ionizing radiation in 1943. However, workers, scholars, and policy makers have questioned the accuracy and completeness of radiation monitoring and its capacity to provide a basis for workers' compensation. We use interviews to explore the limitations of broad-scale, corporate epidemiological surveillance through worker accounts from the Savannah River Site nuclear weapons plant. Interviewees report inadequate monitoring, overbearing surveillance, limited venues to access medical support and exposure records, and administrative failure to report radiation and other exposures at the plant. The alienation of workers from their records and toil is relevant to worker compensation programs and the accuracy of radiation dose measurements used in epidemiologic studies of occupational radiation exposures at the Savannah River Site and other weapons plants. © The Author(s) 2016.

Presentation on mechanisms and applications of chalcopyrite and pyrite bioleaching in biohydrometallurgy - a presentation.

Science.gov (United States)

Tao, Huang; Dongwei, Li

2014-12-01

This review outlines classic and current research, scientific documents and research achievements in bioleaching, particularly in respect of the bioleaching of chalcopyrite and pyrite. The diversity and commonality of the microbial leaching process can be easily studied through comparing the bioleaching mechanism and the application of these two metal sulfides. The crystal, electronic and surface structures of chalcopyrite and pyrite are summarized in detail in this paper. It determines the specific and complicated interaction pathways, kinetics of the atmospheric/aqueous oxidation, and the control process of bioleaching of the minerals as the precondition. Bioleaching of metal sulfides is performed by a diverse group of microorganisms and microbial communities. The species of the bacteria which have a significant effect on leaching ores are miraculously diverse. The newly identified acidophilic microorganisms with unique characteristics for efficient bioleaching of sulfidic minerals are increasing sharply. The cell-to-cell communication mechanisms, which are still implicit, elusive and intangible at present day, have gradually become a research hotspot. The different mineralogy characteristics and the acid solubility of the metal sulfides (e.g., chalcopyrite and pyrite) cause two different dissolution pathways, the thiosulfate and the polysulfide pathways. The bioleaching mechanisms are categorized by contact (an electrostatic attachment) and noncontact (planktonic) process, with emphasis on the produce of extracellular polymeric substances and formation of biofilm on the surface of the metal sulfides in this paper. The division of the direct and indirect effect are not adopted due to the redox chain, the reduction of the ferric iron and oxidation of the ferrous iron. The molecular oxygen is reduced by the electrons extracted from the specific metal sulfide, via a redox chain forming a supercomplex spanning the periplasmic space and connecting both outer and inner

Reactivity of Dazomet, a Hydraulic Fracturing Additive: Hydrolysis and Interaction with Pyrite

Science.gov (United States)

Consolazio, N.; Lowry, G. V.; Karamalidis, A.; Hakala, A.

2015-12-01

The Marcellus Shale is currently the largest shale gas formation in play across the world. The low-permeability formation requires hydraulic fracturing to be produced. In this process, millions of gallons of water are blended with chemical additives and pumped into each well to fracture the reservoir rock. Although additives account for less than 2% of the fracking fluid mixture, they amount to hundreds of tons per frack job. The environmental properties of some of these additives have been studied, but their behavior under downhole conditions is not widely reported in the peer-reviewed literature. These compounds and their reaction products may return to the surface as produced or waste water. In the event of a spill or release, this water has the potential to contaminate surface soil and water. Of these additives, biocides may present a formidable challenge to water quality. Biocides are toxic compounds (by design), typically added to the Marcellus Shale to control bacteria in the well. An assessment of the most frequently used biocides indicated a need to study the chemical dazomet under reservoir conditions. The Marcellus Shale contains significant deposits of pyrite. This is a ubiquitous mineral within black shales that is known to react with organic compounds in both oxic and anoxic settings. Thus, the objective of our study was to determine the effect of pyrite on the hydrolysis of dazomet. Liquid chromatography-triple quadrupole mass spectrometry (LC-QQQ) was used to calculate the loss rate of aqueous dazomet. Gas chromatography-mass spectrometry (GC-MS) was used to identify the reaction products. Our experiments show that in water, dazomet rapidly hydrolyses in water to form organic and inorganic transformation products. This reaction rate was unaffected when performed under anoxic conditions. However, with pyrite we found an appreciable increase in the removal rate of dazomet. This was accompanied by a corresponding change in the distribution of observed

Invisible and microscopic gold in pyrite: Methods and new data for massive sulfide ores of the Urals

Science.gov (United States)

Vikentyev, I. V.

2015-07-01

Au speciation in sulfides (including "invisible" Au), which mostly controls the loss of Au during ore dressing, is discussed. Modern methods of analysis of Au speciation, with discussion of limitations by locality and sensitivity, are reviewed. The results of sulfide investigation by the methods of scanning and transmission electron microscopy, mass spectrometric analysis with laser ablation (LA-ICP-MS), the thermochemical method (study of ionic Au speciation), and automated "quantitative mineralogy," are demonstrated for weakly metamorphosed VHMS deposits of the Urals (Galkinsk and Uchaly). Significant content of Au is scattered in sulfides, such as pyrite, chalcopyrite, and sphalerite, with quantitative predomination of pyrite. The portion of such "invisible" gold ranges from flakes) with a monocrystal diffraction pattern of some particles and a ring diffraction pattern of other particles was registered in the ores of these deposits by the methods of transmission electron microscopy. The low degree (or absence) of metamorphic recrystallization results in (1) predomination of thin intergrowths of sulfides, which is the main reason for the bad concentration of ores (especially for the Galkinsk deposit) and (2) the high portion of "invisible" gold in the massive sulfide ores, which explains the low yield of Au in copper and zinc concentrates, since it is lost in tailings with predominating pyrite.

Restoring oak forest, woodlands and savannahs using modern silvicultural analogs to historic cultural fire regimes

Science.gov (United States)

Daniel C. Dey; Richard P. Guyette; Callie J. Schweitzer; Michael C. Stambaugh; John M. Kabrick

2015-01-01

Variability in historic fire regimes in eastern North America resulted in an array of oak savannahs, woodlands and forests that were dominant vegetation types throughout the region. In the past century, once abundant savannahs and woodlands have become scarce due to conversion to agriculture, or development of forest structure in the absence of fire. In addition, the...

Criticality safety engineering at the Savannah River Site - the 1990s

International Nuclear Information System (INIS)

Chandler, J.R.; Apperson, C.E. Jr.

1996-01-01

The privatization and downsizing effort that is ongoing within the U.S. Department of Energy (DOE) is requiring a change in the management of criticality safety engineering resources at the Savannah River Site (SRS). Downsizing affects the number of criticality engineers employed by the prime contractor, Westinghouse Savannah River Company (WSRC), and privatization affects the manner in which business is conducted. In the past, criticality engineers at the SRS have been part of the engineering organizations that support each facility handling fissile material. This practice led to different criticality safety engineering organizations dedicated to fuel fabrication activities, reactor loading and unloading activities, separation and waste management operations, and research and development

Annual report of ecological research at the Savannah River Ecology Laboratory

International Nuclear Information System (INIS)

1984-09-01

This report summarizes research conducted at the Savannah River Ecology Laboratory (SREL) during the annual period ending August 1, 1984. SREL is a regional research facility at the Savannah River Plant operated by the University of Georgia through a contract with the Department of Energy. It is part of the University of Georgia's Institute of Ecology. The overall goal of the research is to develop an understanding of the impact of various energy technologies and management practices on the ecosystems of the southeastern United States. SREL research is conducted by interdisciplinary research teams organized under three major divisions: (1) Biogeochemical Ecology, (2) Wetlands Ecology, and (3) Stress and Wildlife Ecology

Recovery of plutonium from electrorefining anode heels at Savannah River

International Nuclear Information System (INIS)

Gray, J.H.; Gray, L.W.; Karraker, D.G.

1987-03-01

In a joint effort, the Savannah River Laboratory (SRL), Savannah River Plant (SRP), and the Rocky Flats Plant (RFP) have developed two processes to recover plutonium from electrorefining anode heel residues. Aqueous dissolution of anode heel metal was demonstrated at SRL on a laboratory scale and on a larger pilot scale using either sulfamic acid or nitric acid-hydrazine-fluoride solutions. This direct anode heel metal dissolution requires the use of a geometrically favorable dissolver. The second process developed involves first diluting the plutonium in the anode heel residues by alloying with aluminum. The alloyed anode heel plutonium can then be dissolved using a nitric acid-fluoride-mercury(II) solution in large non-geometrically favorable equipment where nuclear safety is ensured by concentration control

Livers, guts and gills: mapping the decay profiles of soft tissues to understand authigenic mineral replacement.

Science.gov (United States)

Clements, Thomas; Purnell, Mark; Gabbott, Sarah

2016-04-01

The hard mineralised parts of organisms such as shells, teeth and bones dominate the fossil record. There are, however, sites around the world where soft-tissues are preserved often through rapid replacement of original tissue by rapidly-precipitating authigenic minerals. These exceptionally well-preserved soft-bodied fossils are much more informative about the anatomy, physiology, ecology and behaviour of ancient organisms as well as providing a more inclusive picture of ecosystems and evolution throughout geological time. However, despite the wealth of information that soft-bodied fossils can provide they must first be correctly interpreted as the processes of both decay and preservation act to modify the carcass from its in vivo condition. Decay leads to alteration of the appearance and topology of anatomy, and ultimately to loss. Preservation is selective with some anatomical features being more likely to be captured than others. These problems are especially germane to the interpretation of deep-time and/or enigmatic fossils where no modern analogue exist for comparative anatomical analysis. It is therefore of vital importance to understand the processes carcasses undergo during the fossilisation process, , in order to interpret the anatomical remains of fossils and thus extract true evolutionary presence or absence of anatomy from absence due to taphonomic biases. We have designed a series of novel experiments to investigate, in real time, how decay processes affect the fossilisation potential of soft-tissues - especially of internal anatomy. Our data allow us to unravel both the timing and sequence of anatomical decay of different organs. At the same time through measuring Eh and pH in selected organs we can predict when anatomical features will fall in to the window of authigenic mineralization and thus potentially become preserved. We can also place constraints on which minerals will operate to capture tissues. Our findings are applied to the fossil record

S/Se ratio of pyrite from eastern Australian VHMS deposits: implication of magmatic input into volcanogenic hydrothermal systems

Energy Technology Data Exchange (ETDEWEB)

Huston, D L [Geological Survey of Canada, Ottawa, ON (Canada); Sie, S H; Suter, G F [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience; Cooke, D R [Tasmania Univ., Sandy Bay, TAS (Australia)

1994-12-31

The proton microprobe was used to determine the concentrations of over twenty trace elements in pyrite grains from four volcanic-hosted massive sulphide (VHMS) deposits in eastern Australia. Of the elements determined, Se has the most potential in resolving important problems in the genesis of this class of ore deposits. This paper summarises analytical conditions, describes the distribution of Se in pyrite in VHMS deposits as determined in this and other studies, discusses the speciation of Se in hydrothermal fluids, and presents a genetic model on the relative contribution of magmatic versus sea water Se (and S) in VHMS systems. 2 refs., 1 fig.

S/Se ratio of pyrite from eastern Australian VHMS deposits: implication of magmatic input into volcanogenic hydrothermal systems

Energy Technology Data Exchange (ETDEWEB)

Huston, D.L. [Geological Survey of Canada, Ottawa, ON (Canada); Sie, S.H.; Suter, G.F. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience; Cooke, D.R. [Tasmania Univ., Sandy Bay, TAS (Australia)

1993-12-31

The proton microprobe was used to determine the concentrations of over twenty trace elements in pyrite grains from four volcanic-hosted massive sulphide (VHMS) deposits in eastern Australia. Of the elements determined, Se has the most potential in resolving important problems in the genesis of this class of ore deposits. This paper summarises analytical conditions, describes the distribution of Se in pyrite in VHMS deposits as determined in this and other studies, discusses the speciation of Se in hydrothermal fluids, and presents a genetic model on the relative contribution of magmatic versus sea water Se (and S) in VHMS systems. 2 refs., 1 fig.

Compilation of Data on the Middle Savannah River for the Analysis of Sub-Daily Flow Variation, 2011-2015

Data.gov (United States)

Department of the Interior — The Nature Conservancy (TNC) has been working with the U.S. Fish and Wildlife Service (USFWS), the U.S Army Corps of Engineers – Savannah District (USACE - Savannah)...

Tritium sample analyses in the Savannah River and associated waterways following the K-reactor release of December 1991

International Nuclear Information System (INIS)

Beals, D.M.; Dunn, D.L.; Hall, G.; Kantelo, M.V.

1992-01-01

An unplanned release of tritiated water occurred at K reactor on SRS between 22-December and 25-December 1991. This water moved down through the effluent canal, Pen Branch, Steel Creek and finally to the Savannah River. Samples were collected in the Savannah River and associated waterways over a period of a month. The Environmental Technology Section (ETS) of the Savannah River Laboratory performed liquid scintillation analyses to monitor the passage of the tritiated water from SRS to the Atlantic Ocean

The Effect of Water Vapor on the Thermal Decomposition of Pyrite in N2 Atmosphere

Directory of Open Access Journals (Sweden)

Nesrin BOYABAT

2009-03-01

Full Text Available In this study, the effect of water vapor on the thermal decomposition of pyrite mineral in nitrogen atmosphere has been investigated in a horizontal tube furnace. Temperature, time and water vapor concentration were used as experimental parameters. According to the data obtained at nitrogen/ water vapor environment, it was observed that the water vapor on the decomposition of pyrite increased the decomposition rate. The decomposition reaction is well represented by the "shrinking core" model and can be divided into two regions with different rate controlling step. The rate controlling steps were determined from the heat transfer through the gas film for the low conversions, while it was determined from the mass transfer through product ash layer for the high conversions. The activation energies of this gas and ash film mechanisms were found to be 77 and 81 kJ/mol-1, respectively.

Thermodynamic Cconstraints on Coupled Carbonate-Pyrite Weathering Dynamics and Carbon Fluxes

Science.gov (United States)

Winnick, M.; Maher, K.

2017-12-01

Chemical weathering within the critical zone regulates global biogeochemical cycles, atmospheric composition, and the supply of key nutrients to terrestrial and aquatic ecosystems. Recent studies suggest that thermodynamic limits on solute production act as a first-order control on global chemical weathering rates; however, few studies have addressed the factors that set these thermodynamic limits in natural systems. In this presentation, we investigate the effects of soil CO2 concentrations and pyrite oxidation rates on carbonate dissolution and associated carbon fluxes in the East River watershed in Colorado, using concentration-discharge relationships and thermodynamic constraints. Within the shallow subsurface, soil respiration rates and moisture content determine the extent of carbonic acid-promoted carbonate dissolution through their modulation of soil pCO2 and the balance of open- v. closed-system weathering processes. At greater depths, pyrite oxidation generates sulfuric acid, which alters the approach to equilibrium of infiltrating waters. Through comparisons of concentration-discharge data and reactive transport model simulations, we explore the conditions that determine whether sulfuric acid reacts to dissolve additional carbonate mineral or instead reacts with alkalinity already in solution - the balance of which determines watershed carbon flux budgets. Our study highlights the importance of interactions between the chemical structure of the critical zone and the hydrologic regulation of flowpaths in determining concentration-discharge relationships and overall carbon fluxes.

Assessment of Savannah River borosilicate glass in the repository environment

International Nuclear Information System (INIS)

Plodinec, M.J.; Wicks, G.G.; Bibler, N.E.

1982-04-01

Since 1973, borosilicate glass has been studied as a matrix for the immobilization of high-level radioactive waste generated at the Savannah River Plant (SRP). In 1977, efforts began to develop and test the large-scale equipment necessary to convert the alkaline waste slurries at SRP into a durable borosilicate glass. A process has now been developed for the proposed Defense Waste Processing Facility (DWPF) which will annually produce approximately 500 canisters of SRP waste glass which will be stored on an interim basis on the Savannah River site. Current national policy calls for the permanent disposal of high-level waste in deep geologic repositories. In the repository environment, SRP waste glass will eventually be exposed to such stresses as lithostatic or hydrostatic pressures, radiation fields, and self-heating due to radioactive decay. In addition, producing and handling each canister of glass will also expose the glass to thermal and mechanical stresses. An important objective of the extensive glass characterization and testing programs of the Savannah River Laboratory (SRL) has been to determine how these stresses affect the performance of SRP waste glass. The results of these programs indicate that: these stresses will not significantly affect the performance of borosilicate glass containing SRP waste; and SRP waste glass will effectively immobilize hazardous radionuclides in the repository environment

Habitat preferences of foraging red-cockaded woodpeckers at the Savannah River Site, South Carolina.

Energy Technology Data Exchange (ETDEWEB)

Franzreb, Kathleen, E.

2004-12-31

Franzreb, Kathleen, E. 2004. Habitat preferences of foraging red-cockaded woodpeckers at the Savannah River Site, South Carolina. In: Red-cockaded woodpecker; Road to Recovery. Proceedings of the 4th Red-cockaded woodpecker Symposium. Ralph Costa and Susan J. Daniels, eds. Savannah, Georgia. January, 2003. Chapter 9. Habitat Management and Habitat Relationships. Pp 553-561. Abstract: I constructed a foraging study to examine habitat use of red-cockaded woodpeckers at the Savannah River Site, South Carolina. Because much of the land had been harvested in the late 1940s and early 1950s prior to being sold to the Department of Energy, the available habitat largely consisted of younger trees (e.g., less than 40 years old). From 1992 to 1995, I examined the foraging behavior and reproductive success of 7 groups of red-cockaded woodpeckers.

Carolina bays of the Savannah River Plant

Energy Technology Data Exchange (ETDEWEB)

Schalles, J.F. (Creighton Univ., Omaha, NE (USA)); Sharitz, R.R.; Gibbons, J.W.; Leversee, G.J.; Knox, J.N. (Savannah River Ecology Lab., Aiken, SC (USA))

1989-01-01

Much of the research to date on the Carolina bays of the Savannah River Plant and elsewhere has focused on certain species or on environmental features. Different levels of detail exist for different groups of organisms and reflect the diverse interests of previous investigators. This report summarizes aspects of research to date and presents data from numerous studies. 70 refs., 14 figs., 12 tabs.

Savannah River waste plant takes another broadside

International Nuclear Information System (INIS)

Setzer, S.W.

1992-01-01

This article is a discussion of Government Accounting Office findings related to the high-level waste disposal facilities, and in particular the Defense Waste Processing Facility, at Savannah River. Cost and schedule problems are noted, and the report concluded that ineffective management, both by DOE personnel and M ampersand AO contractor personnel, was a principal factor contributing to these problems at the DWPF and supporting facilities

Tiger Team Assessment of the Savannah River Site: Appendices

International Nuclear Information System (INIS)

1990-06-01

This draft document contains findings identified during the Tiger Team Compliance Assessment of the US Department of Energy Savannah River Site (SRS), located in three countries (Aiken, Barnwell and Allendale), South Carolina. The Assessment was directed by the Department's Office of the Assistant Secretary for Environment, Safety, and Health (ES ampersand H) and was conducted from January 29 to March 23, 1990. The Savannah River Site Tiger Team Compliance Assessment was broad in scope covering the Environment, Safety and Health, and Management areas and was designed to determine the site's compliance with applicable Federal (including DOE), state, and local regulations and requirements. The scope of the Environmental assessment was sitewide while the Safety and Health assessments included site operating facilities (except reactors), and the sitewide elements of Aviation Safety, Emergency Preparedness, Medical Services, and Packaging and Transportation. This report contains the appendices to the assessment

Critical Radionuclide and Pathway Analysis for the Savannah River Site, 2016 Update

Energy Technology Data Exchange (ETDEWEB)

Jannik, Tim [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hartman, Larry [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2016-09-08

During the operational history of Savannah River Site, many different radionuclides have been released from site facilities. However, as shown in this analysis, only a relatively small number of the released radionuclides have been significant contributors to doses to the offsite public. This report is an update to the 2011 analysis, Critical Radionuclide and Pathway Analysis for the Savannah River Site. SRS-based Performance Assessments for E-Area, Saltstone, F-Tank Farm, H-Tank Farm, and a Comprehensive SRS Composite Analysis have been completed. The critical radionuclides and pathways identified in those extensive reports are also detailed and included in this analysis.

Demonstration of Caustic-Side Solvent Extraction with Savannah River Site High Level Waste

International Nuclear Information System (INIS)

Walker, D.D.

2001-01-01

Researchers successfully demonstrated the chemistry and process equipment of the Caustic-Side Solvent Extraction (CSSX) flowsheet for the decontamination of high level waste using a 33-stage, 2-cm centrifugal contactor apparatus at the Savannah River Technology Center. This represents the first CSSX process demonstration using Savannah River Site (SRS) high level waste. Three tests lasting 6, 12, and 48 hours processed simulated average SRS waste, simulated Tank 37H/44F composite waste, and Tank 37H/44F high level waste, respectively

Summary of the Preliminary Analysis of Savannah River Depleted Uranium Trioxide

International Nuclear Information System (INIS)

2010-01-01

This report summarizes a preliminary special analysis of the Savannah River Depleted Uranium Trioxide waste stream (SVRSURANIUM03, Revision 2). The analysis is considered preliminary because a final waste profile has not been submitted for review. The special analysis is performed to determine the acceptability of the waste stream for shallow land burial at the Area 5 Radioactive Waste Management Site (RWMS) at the Nevada National Security Site (NNSS). The Savannah River Depleted Uranium Trioxide waste stream requires a special analysis because the waste stream's sum of fractions exceeds one. The 99Tc activity concentration is 98 percent of the NNSS Waste Acceptance Criteria and the largest single contributor to the sum of fractions.

Savannah River Site dose control

International Nuclear Information System (INIS)

Smith, L.S.

1992-01-01

Health physicists from the Brookhaven National Laboratory (BNL) visited the Savannah River Site (SRS) as one of 12 facilities operated by the Department of Energy (DOE) contractors with annual collective dose equivalents greater than 100 person-rem (100 person-cSv). Their charter was to review, evaluate and summarize as low as reasonably achievable (ALARA) techniques, methods and practices as implemented. This presentation gives an overview of the two selected ALARA practices implemented at the SRS: Administrative Exposure Limits and Goal Setting. These dose control methods are used to assure that individual and collective occupational doses are ALARA and within regulatory limits

Waste management units - Savannah River Site

International Nuclear Information System (INIS)

1989-10-01

This report is a compilation of worksheets from the waste management units of Savannah River Plant. Information is presented on the following: Solid Waste Management Units having received hazardous waste or hazardous constituents with a known release to the environment; Solid Waste Management Units having received hazardous waste or hazardous constituents with no known release to the environment; Solid Waste Management Units having received no hazardous waste or hazardous constituents; Waste Management Units having received source; and special nuclear, or byproduct material only

Savannah River Plant Separations Department mixed waste program

International Nuclear Information System (INIS)

Wierzbicki, W.M.

1988-01-01

The Department of Energy's (DOE) Savannah River Plant (SRP) generates radioactive and mixed waste as a result of the manufacture of nuclear material for the national defense program. The radioactive portion of the mixed waste and all nonhazardous radioactive wastes would continue to be regulated by DOE under the Atomic Energy Act. The Separations Department is the largest generator of solid radioactive waste at the Savannah River Plant. Over the last three years, the Separations Department has developed and implemented a program to characterize candidate mixed-waste streams. The program consisted of facility personnel interviews, a waste-generation characterization program and waste testing to determine whether a particular waste form was hazardous. The Separations Department changed waste-handling practices and procedures to meet the requirements of the generator standards. For each Separation Department Facility, staging areas were established, inventory and reporting requirements were developed, operating procedures were revised to ensure proper waste handling, and personnel were provided hazardous waste training. To emphasize the importance of the new requirements, a newsletter was developed and issued to all Separations supervisory personnel

Disposal of Draeger Tubes at Savannah River Site

International Nuclear Information System (INIS)

Malik, N.P.

2000-01-01

The Savannah River Site (SRS) is a Department of Energy (DOE) facility located in Aiken, South Carolina that is operated by the Westinghouse Savannah River Company (WSRC). At SRS Draeger tubes are used to identify the amount and type of a particular chemical constituent in the atmosphere. Draeger tubes rely on a chemical reaction to identify the nature and type of a particular chemical constituent in the atmosphere. Disposal practices for these tubes were identified by performing a hazardous waste evaluation per the Resource Conservation and Recovery Act (RCRA). Additional investigations were conducted to provide guidance for their safe handling, storage and disposal. A list of Draeger tubes commonly used at SRS was first evaluated to determine if they contained any material that could render them as a RCRA hazardous waste. Disposal techniques for Draeger tubes that contained any of the toxic contaminants listed in South Carolina Hazardous Waste Management Regulations (SCHWMR) R.61-79. 261.24 (b) and/or contained an acid in the liquid form were addressed

determination of toxicity levels of some savannah plants using brine

African Journals Online (AJOL)

DR. AMINU

DETERMINATION OF TOXICITY LEVELS OF SOME SAVANNAH PLANTS. USING BRINE ... Adoum, O. A.. Department of Pure and Industrial Chemistry, Bayero University, P.M.B. 3011, Kano – Nigeria. ... 1000, 100, and 10 µg/ml, respectively.

Independent technical review of Savannah River Site Defense Waste Processing Facility technical issues

International Nuclear Information System (INIS)

1992-07-01

The Savannah River Site (SRS) Defense Waste Processing Facility (DWPF) will vitrify high-level radioactive waste that is presently stored as liquid, salt-cake, and sludge in 51 waste-storage tanks. Construction of the DWPF began in 1984, and the Westinghouse Savannah Company (WSRC) considers the plant to be 100% turned over from construction and 91% complete. Cold-chemical runs are scheduled to begin in November 1992, and hot start up is projected for June 1994. It is estimated that the plant lifetime must exceed 15 years to complete the vitrification of the current, high-level tank waste. In a memo to the Assistant Secretary for Defense Programs (DP-1), the Assistant Secretary for Environmental Restoration and Waste management (EM-1) established the need for an Independent Technical Review (ITR), or the Red Team, to ''review process technology issues preventing start up of the DWPF.'' This report documents the findings of an Independent Technical Review (ITR) conducted by the Department of Energy (DOE), Office of Environmental Restoration and Waste Management (EM), at the request of the Assistant Secretary for Environmental Restoration and Waste Management, of specified aspects of Defense Waste Process Facility (DWPF) process technology. Information for the assessment was drawn from documents provided to the ITR Team by the Westinghouse Savannah River Company (WSRC), and presentations, discussions, interviews, and tours held at the Savannah River Site (SRS) during the weeks of February and March 9, 1992

Site specific plan. [Environmental Restoration and Waste Management, Savannah River Site

Energy Technology Data Exchange (ETDEWEB)

Hutchison, J.; Jernigan, G.

1989-12-01

The Environmental Restoration and Waste Management Five-Year Plan (FYP) covers the period for FY 1989 through FY 1995. The plan establishes a Department of Energy -- Headquarters (DOE-HQ) agenda for cleanup and compliance against which overall progress can be measured. The FYP covers three areas: Corrective Activities, Environmental Restoration, and Waste Management Operations. Corrective Activities are those activities necessary to bring active or standby facilities into compliance with local, state, and federal environmental regulations. Environmental restoration activities include the assessment and cleanup of surplus facilities and inactive waste sites. Waste management operations includes the treatment, storage, and disposal of wastes which are generated as a result of ongoing operations. This Site Specific Plan (SSP) has been prepared by the Savannah River Site (SRS) in order to show how environmental restoration and waste management activities that were identified during the preparation of the FYP will be implemented, tracked, and reported. The SSP describes DOE Savannah River (DOE-SR) and operating contractor, Westinghouse Savannah River Company (WSRC), organizations that are responsible, for undertaking the activities identified in this plan. The SSP has been prepared in accordance with guidance received from DOE-HQ. DOE-SR is accountable to DOE-HQ for the implementation of this plan. 8 refs., 46 figs., 23 tabs.

STREAM II-V7: Revision for STREAM II-V6 to include outflow from all Savannah River Site tributaries

Energy Technology Data Exchange (ETDEWEB)

Maze, Grace M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-01-01

STREAM II is the aqueous transport model of the Weather Information Display (WIND) emergency response system at Savannah River Site. It is used to calculate transport in the event of a chemical or radiological spill into the waterways on the Savannah River Site. Improvements were made to the code (STREAM II V7) to include flow from all site tributaries to the Savannah River total flow and utilize a 4 digit year input. The predicted downstream concentrations using V7 were generally on the same order of magnitude as V6 with slightly lower concentrations and quicker arrival times when all onsite stream flows are contributing to the Savannah River flow. The downstream arrival time at the Savannah River Water Plant ranges from no change to an increase of 8.77%, with minimum changes typically in March/April and maximum changes typically in October/November. The downstream concentrations are generally no more than 15% lower using V7 with the maximum percent change in January through April and minimum changes in June/July.

Examples of Savannah River water dilution between the Savannah River Plant and the Beaufort-Jasper and Port Wentworth water-treatment plants

International Nuclear Information System (INIS)

Hayes, D.W.

1983-01-01

A substantial dilution of the river water occurs between the Savannah River Plant (SRP) and the two treatment plants. This dilution results from inflow of surface and groundwater and from direct rainfall. The amount of dilution was estimated to be approximately 20% and 54% down to the Port Wentworth and Beaufort-Jasper plants, respectively

Review of advanced reactor transient analysis capabilities and applications for Savannah River Plant reactors

International Nuclear Information System (INIS)

Buckner, M.R.; Hostetler, D.E.; Anderson, M.M.; Dodds, H.L.

1977-01-01

GRASS is a three-dimensional, coupled neutronic and engineering code for analysis of the radioisotope production reactors at the Savannah River Plant. The capabilities of GRASS are reviewed with emphasis on recent additions to model accident conditions involving the transport of molten fuel material and to accurately characterize neutronic and engineering feedback. The general application of GRASS to the Savannah River reactors is discussed, and results are presented for the analyses of severla reactor transient calculations

New Low-Level Radioactive Waste Storage/Disposal Facilities at the Savannah River Plant: Environmental information document

International Nuclear Information System (INIS)

Cook, J.R.; Grant, M.W.; Towler, O.O.

1987-04-01

Site selection, alternative facilities, and alternative operations are described for a new low-level solid radioactive waste storage/disposal operation at the Savannah River Plant. Performance assessments and cost estimates for the alternatives are presented. Appendix G contains an intensive archaeological survey of alternative waste disposal areas in the Savannah River Plant area. 117 refs., 99 figs., 128 tabs

Assessment of Radionuclides in the Savannah River Site Environment Summary

Energy Technology Data Exchange (ETDEWEB)

Carlton, W.H.

1999-01-26

This document summarizes the impact of radionuclide releases from Savannah River Site (SRS) facilities from 1954 through 1996. The radionuclides reported here are those whose release resulted in the highest dose to people living near SRS.

Assessment of Soil Erosion Methods for Sludge Recovery, Savannah River Site

National Research Council Canada - National Science Library

Smith, Lawson

1997-01-01

...) from selected storage tanks at the Savannah River Site (SRS) was assessed conceptually. Soil erosion methods are defined as the processes of soil detachment, entrainment, transport, and deposition...

SAVANNAH RIVER SITE CAPABILITIES FOR CONDUCTING INGESTION PATHWAY CONSEQUENCE ASSESSMENTS FOR EMERGENCY RESPONSE

Energy Technology Data Exchange (ETDEWEB)

Hunter, C

2007-12-11

Potential airborne releases of radioactivity from facilities operated for the U. S. Department of Energy at the Savannah River Site could pose significant consequences to the public through the ingestion pathway. The Savannah River National Laboratory has developed a suite of technologies needed to conduct assessments of ingestion dose during emergency response, enabling emergency manager at SRS to develop initial protective action recommendation for state agencies early in the response and to make informed decisions on activation of additional Federal assets that would be needed to support long-term monitoring and assessment activities.

Numerical Weather Forecasting at the Savannah River Site

International Nuclear Information System (INIS)

Buckley, R.L.

1999-01-01

Facilities such as the Savannah River Site (SRS), which contain the potential for hazardous atmospheric releases, rely on the predictive capabilities of dispersion models to assess possible emergency response actions. The operational design in relation to domain size and forecast time is presented, along with verification of model results over extended time periods with archived surface observations

A study of the process of joint formation of methane gas-hydrate and authigenic carbonates in bottom sediments in the Sea of Okhotsk

Energy Technology Data Exchange (ETDEWEB)

Esikov, A D [AN SSSR, Moscow (USSR). Water Problems Inst.; Pashkina, V I [AN SSSR, Moscow (USSR). Inst. Okeanologii

1990-01-01

The discovery of gas-hydrates in bottom sediments in the Sea of Okhotsk has allowed isotope fractionation of oxygen and hydrogen to be determined in the formation of the crystal lattice. It was established that the structure of gas-hydrate selectively included the heavier isotopes of oxygen and hydrogen, so that the gas-hydrate water had values of {delta}{sup 18}O = +1.9 per mille and {delta}D = +23 per mille, whereas the interstitial water was ''lighter'' in isotopes, with the values of {delta}{sup 18}O = -0.5 per mille and {delta}D = -5 per mille (relative to SMOW (standard mean ocean water)). The formation of gas-hydrates under the conditions of underwater discharge of methane alters the chemical composition of interstitial water, so that the carbonate equilibrium is shifted, and carbonates of authigenic origin are formed. The isotope composition of the carbonates is characterized by a low content of {sup 13}C({delta}{sup 13}C from -39.3 to -51.8 per mille PDB) and a high content of {sup 18}O({delta}{sup 18}O from + 2.7 to +6.3 per mille PDB) in comparison with carbonates of sea origin. These characteristics of the isotope composition suggest the participation of methane in the formation of authigenic carbonates, due to its anaerobic oxidation and the involvement of sulfate in the silt water. (author).

U-Pb isotope and trace element compositions of pyrites in the Black Reef: implications on their age and origin

International Nuclear Information System (INIS)

Barton, E.S.

1990-01-01

In the Black Reef Quartzite Formation of the Transvaal Supergroup two gold-bearing conglomerate facies have been recognized. The source of gold in these reefs has long been a matter of speculation. Although some ascribe the gold and pyrite to a hydrothermal origin, the prevailing opinion favours a detrital origin. As a possible source, the reworked underlying sub-outcrops of the Kimberly Reef horizons in the Central Rand group have been proposed. An investigation was undertaken with the aim of defining the Pb-isotopic and trace element signatures of morphologically different pyrite populations within the two Black Reef facies as well as for the underlying Kimberly Reef. 2 tabs

Long-term forest-savannah dynamics in the Bolivian Amazon: implications for conservation.

Science.gov (United States)

Mayle, Francis E; Langstroth, Robert P; Fisher, Rosie A; Meir, Patrick

2007-02-28

The aim of this paper is to evaluate the respective roles of past changes in climate, geomorphology and human activities in shaping the present-day forest-savannah mosaic of the Bolivian Amazon, and consider how this palaeoecological perspective may help inform conservation strategies for the future. To this end, we review a suite of palaeoecological and archaeological data from two distinct forest-savannah environments in lowland Bolivia: Noel Kempff Mercado National Park (NKMNP) on the Precambrian Shield and the 'Llanos de Moxos' in the Beni basin. We show that they contain markedly contrasting legacies of past climatic, geomorphic and anthropogenic influences between the last glacial period and the Spanish Conquest. In NKMNP, increasing precipitation caused evergreen rainforest expansion, at the expense of semi-deciduous dry forest and savannahs, over the last three millennia. In contrast, pre-Hispanic indigenous cultures were instrumental in facilitating recent forest expansion in the Llanos de Moxos by building a vast network of earthworks. Insights from Mid-Holocene palaeodata, together with ecological observations and modelling studies, suggest that there will be progressive replacement of rainforest by dry forest and savannah in NKMNP over the twenty-first century in response to the increased drought predicted by general circulation models. Protection of the latitudinal landscape corridors may be needed to facilitate these future species reassortments. However, devising appropriate conservation strategies for the Llanos de Moxos will be more difficult due to its complex legacy of Palaeo-Indian impact. Without fully understanding the degree to which its current biota has been influenced by past native cultures, the type and intensity of human land use appropriate for this landscape in the future will be difficult to ascertain.

Instream biological assessment of NPDES point source discharges at the Savannah River Site, 1997-1998

International Nuclear Information System (INIS)

Specht, W.L.

2000-01-01

The Savannah River Site currently has 33 permitted NPDES outfalls that have been permitted by the South Carolina Department of Health an Environmental Control to discharge to SRS streams and the Savannah River. In order to determine the cumulative impacts of these discharges to the receiving streams, a study plan was developed to perform in-stream assessments of the fish assemblages, macroinvertebrate assemblages, and habitats of the receiving streams

Instream biological assessment of NPDES point source discharges at the Savannah River Site, 1997-1998

Energy Technology Data Exchange (ETDEWEB)

Specht, W.L.

2000-02-28

The Savannah River Site currently has 33 permitted NPDES outfalls that have been permitted by the South Carolina Department of Health an Environmental Control to discharge to SRS streams and the Savannah River. In order to determine the cumulative impacts of these discharges to the receiving streams, a study plan was developed to perform in-stream assessments of the fish assemblages, macroinvertebrate assemblages, and habitats of the receiving streams.

Savannah River Ecology Laboratory, Annual Technical Progress Report of Ecological Research, June 30, 2002

Energy Technology Data Exchange (ETDEWEB)

Paul M. Bertsch, (Director)

2002-06-30

The Savannah River Ecology Laboratory (SREL) is a research unit of The University of Georgia (UGA) and has been conducting ecological research on the Savannah River Site (SRS) near Aiken, South Carolina for 50 years. The overall mission of the Laboratory is to acquire and communicate knowledge of ecological processes and principles. SREL conducts fundamental and applied ecological research, as well as education and outreach programs, under a Cooperative Agreement with the U.S. Department of Energy (DOE). The Laboratory's research mission during the 2002 fiscal year was fulfilled with the publication of 76 journal articles and book chapters by faculty, technical staff, students, and visiting scientists. An additional 50 journal articles have been submitted or are in press. Other noteworthy events took place as faculty members, staff, and graduate students received awards. These are described in the section titled Special Accomplishments of Faculty, Staff, Students, and Administration on page 51. Notable scientific accomplishments include work conducted on contaminant transport, stable isotopes, sandhills ecology, and phytoremediation: (1) A collaborative study between Dr. Tom Hinton at SREL and scientists at SRTC demonstrated the feasibility of using illite clay to sequester 137Cs in sediments along the P and R reactor cooling canal system, where approximately 3,000 acres of land are contaminated. Overall, the study showed significant decreases in cesium concentrations and bioavailability following the addition of illite with no sign of harm to the ecosystem. While the cesium remains sequestered from the biosphere, its radioactivity decays and the process progresses from contaminant immobilization to remediation. (2) SREL's stable isotope laboratory is now fully functional. Stable isotope distributions in nature can provide important insights into many historical and current environmental processes. Dr. Christopher Romanek is leading SREL's research

Savannah River Ecology Laboratory, Annual Technical Progress Report of Ecological Research, June 30, 2002

International Nuclear Information System (INIS)

Paul M. Bertsch,

2002-01-01

The Savannah River Ecology Laboratory (SREL) is a research unit of The University of Georgia (UGA) and has been conducting ecological research on the Savannah River Site (SRS) near Aiken, South Carolina for 50 years. The overall mission of the Laboratory is to acquire and communicate knowledge of ecological processes and principles. SREL conducts fundamental and applied ecological research, as well as education and outreach programs, under a Cooperative Agreement with the U.S. Department of Energy (DOE). The Laboratory's research mission during the 2002 fiscal year was fulfilled with the publication of 76 journal articles and book chapters by faculty, technical staff, students, and visiting scientists. An additional 50 journal articles have been submitted or are in press. Other noteworthy events took place as faculty members, staff, and graduate students received awards. These are described in the section titled Special Accomplishments of Faculty, Staff, Students, and Administration on page 51. Notable scientific accomplishments include work conducted on contaminant transport, stable isotopes, sandhills ecology, and phytoremediation: (1) A collaborative study between Dr. Tom Hinton at SREL and scientists at SRTC demonstrated the feasibility of using illite clay to sequester 137Cs in sediments along the P and R reactor cooling canal system, where approximately 3, 000 acres of land are contaminated. Overall, the study showed significant decreases in cesium concentrations and bioavailability following the addition of illite with no sign of harm to the ecosystem. While the cesium remains sequestered from the biosphere, its radioactivity decays and the process progresses from contaminant immobilization to remediation. (2) SREL's stable isotope laboratory is now fully functional. Stable isotope distributions in nature can provide important insights into many historical and current environmental processes. Dr. Christopher Romanek is leading SREL's research in this area

Capabilities and modification plans for the Savannah River New Special Recovery facilities

International Nuclear Information System (INIS)

Gray, L.W.; Molen, G.F.; Lynn, J.M.

1986-01-01

The Savannah River New Special Recovery (NSR) facility is located in the 200-F Separations Area. This facility was designed and constructed to convert easily dissolvable plutonium oxides and metal from both onsite and offsite residues to plutonium nitrate-nitric acid solution. Capabilities were provided to purify a portion of the clarified dissolver solutions via anion exchange. The primary purification is provided by the 221-F canyon solvent extraction system. Minimal capacity was provided to handle slurries from poorly dissolving materials. The Actinide Technology Division of the Savannah River Laboratory is presently engaged in R and D to enhance both the solids throughput of the dissolvers and the feed clarification methods

Land cover mapping and GIS processing for the Savannah River Site Database

International Nuclear Information System (INIS)

Christel, L.M.; Guber, A.L.

1994-07-01

The Savannah River Site (SRS) is owned by the U.S. Department of Energy and operated by Westinghouse Savannah River Company. Located in Barnwell, Aiken, and Allendale counties in South Carolina, SRS covers an area of approximately 77,700 hectares. Land cover information for SRS was interpreted from color and color infrared aerial photography acquired between 1980 and 1989. The data were then used as the source of the land cover data layer for the SRS sitewide Geographic Information System database. This database provides SRS managers with recent land use information and has been successfully used to support cost-effective site characterization and reclamation

Savannah River Site environmental report for 1993

International Nuclear Information System (INIS)

Arnett, M.W.; Karapatakis, L.K.; Mamatey, A.R.

1994-01-01

Savannah River Site (SRS) conducts effluent monitoring and environmental surveillance to ensure the safety of the public and the well-being of the environment. DOE Order 5400,1, ''General Environmental Protection Program,'' requires the submission of an environmental report that documents the impact of facility operations on the environment and on public health. SRS has had an extensive environmental surveillance program in place since 1951 (before site startup). At that time, data generated by the on-site surveillance program were reported in site documents. Beginning in 1959, data from off-site environmental monitoring activities were presented in reports issued for public dissemination. Separate reporting of SRS's on- and off-site environmental monitoring activities continued until 1985, when data from both surveillance programs were merged into a single public document. The Savannah River Site Environmental Report for 1993 is an overview of effluent monitoring and environmental surveillance activities conducted on and in the vicinity of SRS from January 1 through December 31, 1993. For complete program descriptions, consult the ''SRS Environmental Monitoring Plan'' (WSRC-3Ql-2-1000). It documents the rationale and design criteria for the monitoring program, the frequency of monitoring and analysis, the specific analytical and sampling procedures, and the quality assurance requirements

Savannah River Site environmental report for 1993

Energy Technology Data Exchange (ETDEWEB)

Arnett, M.W.; Karapatakis, L.K.; Mamatey, A.R. [eds.

1994-08-01

Savannah River Site (SRS) conducts effluent monitoring and environmental surveillance to ensure the safety of the public and the well-being of the environment. DOE Order 5400,1, ``General Environmental Protection Program,`` requires the submission of an environmental report that documents the impact of facility operations on the environment and on public health. SRS has had an extensive environmental surveillance program in place since 1951 (before site startup). At that time, data generated by the on-site surveillance program were reported in site documents. Beginning in 1959, data from off-site environmental monitoring activities were presented in reports issued for public dissemination. Separate reporting of SRS`s on- and off-site environmental monitoring activities continued until 1985, when data from both surveillance programs were merged into a single public document. The Savannah River Site Environmental Report for 1993 is an overview of effluent monitoring and environmental surveillance activities conducted on and in the vicinity of SRS from January 1 through December 31, 1993. For complete program descriptions, consult the ``SRS Environmental Monitoring Plan`` (WSRC-3Ql-2-1000). It documents the rationale and design criteria for the monitoring program, the frequency of monitoring and analysis, the specific analytical and sampling procedures, and the quality assurance requirements.

Risk assessment data bank design at the Savannah River Site

International Nuclear Information System (INIS)

Townsend, C.S.; Johnson, K.B.

1992-01-01

The Savannah River Site has designed and implemented a database system containing a series of compilations of incidents used primarily for risk assessment. Four databases have been designed and implemented using advanced database management system computer software. These databases exist for reprocessing, fuel fabrication, waste management, and the Savannah River Technology Center. They are combined into one system caged the Risk Assessment Methodology (RAM) Fault Tree Data Banks. This paper will discuss the logical design of the data, the menus, and the operating platform. Built-in updating features, such as batch and on-line data entry; data validation methods; automatic update features; and expert system programs, will also be discussed. User functions, such as on-line search/view/report and statistical functions, will be presented. Security features and backup and recovery methods will also be covered

Iberian Pyrite Belt Subsurface Life (IPBSL), a drilling project in a geochemical Mars terrestrial analogue

Science.gov (United States)

Amils, R.; Fernández-Remolar, D. C.; Parro, V.; Manfredi, J. A.; Timmis, K.; Oggerin, M.; Sánchez-Román, M.; López, F. J.; Fernández, J. P.; Omoregie, E.; Gómez-Ortiz, D.; Briones, C.; Gómez, F.; García, M.; Rodríguez, N.; Sanz, J. L.

2012-09-01

Iberian Pyrite Belt Subsurface Life (IPBSL) is a drilling project specifically designed to characterize the subsurface ecosystems operating in the Iberian Pyrite Belt (IPB), in the area of Peña de Hierro, and responsible of the extreme acidic conditions existing in the Rio Tinto basin [1]. Rio Tinto is considered a good geochemical terrestrial analogue of Mars [2, 3]. A dedicated geophysical characterization of the area selected two drilling sites (4) due to the possible existence of water with high ionic content (low resistivity). Two wells have been drilled in the selected area, BH11 and BH10, of depths of 340 and 620 meters respectively, with recovery of cores and generation of samples in anaerobic and sterile conditions. Preliminary results showed an important alteration of mineral structures associated with the presence of water, with production of expected products from the bacterial oxidation of pyrite (sulfates and ferric iron). Ion chromatography of water soluble compounds from uncontaminated samples showed the existence of putative electron donors (ferrous iron, nitrite in addition of the metal sulfides), electron acceptors (sulfate, nitrate, ferric iron) as well as variable concentration of metabolic organic acids (mainly acetate, formate, propionate and oxalate), which are strong signals of the presence of active subsurface ecosystem associated to the high sulfidic mineral content of the IPB. The system is driven by oxidants that appear to be provided by the rock matrix, only groundwater is needed to launch microbial metabolism. The geological, geomicrobiological and molecular biology analysis which are under way, should allow the characterization of this ecosystem of paramount interest in the design of an astrobiological underground Mars exploration mission in the near future.

The Savannah River Site`s Groundwater Monitoring Program. Fourth quarter, 1989

Energy Technology Data Exchange (ETDEWEB)

1989-12-31

The Environmental Monitoring Section of the Environmental and Health Protection (EHP) Department administers the Savannah River Site`s Groundwater Monitoring Program. During fourth quarter 1989 (October--December), EHP conducted routine sampling of monitoring wells and drinking water locations. EHP collected the drinking water samples from Savannah River Site (SRS) drinking water systems supplied by wells. EHP established two sets of flagging criteria in 1986 to assist in the management of sample results. The flagging criteria aid personnel in sample scheduling, interpretation of data, and trend identification. An explanation of flagging criteria for the fourth quarter is presented in the Flagging Criteria section of this document. All analytical results from fourth quarter 1989 are listed in this report, which is distributed to all waste-site custodians.

Nuclear incident monitor criticality alarm instrument for the Savannah River Site: Technical manual

International Nuclear Information System (INIS)

Jenkins, J.B.

1996-01-01

The Savannah River Site is a Department of Energy facility. The facility stores, processes, and works with fissionable material at a number of locations. Technical standards and US Department of Energy orders, require these locations to be monitored by criticality alarm systems under certain circumstances. The Savannah River Site calls such instruments Nuclear Incident Monitors or NIMs. The Sole purpose of the Nuclear Incident Monitor is to provide an immediate evacuation signal in the case of an accidental criticality in order to minimize personnel exposure to radiation. The new unit is the third generation Nuclear Incident Monitor at the Savannah River Site. The second generation unit was developed in 1979. It was designed to eliminate vacuum-tube circuits, and was the first solid state NIM at SRS. The major design objectives of the second generation NIM were to improve reliability and reduce maintenance costs. Ten prototype units have been built and tested. This report describes the design of the new NIM and the testing that took place to verify its acceptability

Model-based integration and analysis of biogeochemical and isotopic dynamics in a nitrate-polluted pyritic aquifer

NARCIS (Netherlands)

Zhang, Y.-C.; Prommer, H.; Broers, H.P.; Slomp, C.P.; Greskowiak, J.; Van Der Grift, B.; Van Cappellen, P.

2013-01-01

Leaching of nitrate from agricultural land to groundwater and the resulting nitrate pollution are a major environmental problem worldwide. Its impact is often mitigated in aquifers hosting sufficiently reactive reductants that can promote autotrophic denitrification. In the case of pyrite acting as

Model-Based Integration and Analysis of Biogeochemical and Isotopic Dynamics in a Nitrate-Polluted Pyritic Aquifer

NARCIS (Netherlands)

Zhang, Y.C.; Prommer, H.; Slomp, C.P.; Broers, H.P.; van der Grift, B.; Passier, H.F.; Greskowiak, J.; Boettcher, M.E.; van Capellen, P.

2013-01-01

Leaching of nitrate from agricultural land to groundwater and the resulting nitrate pollution are a major environmental problem worldwide. Its impact is often mitigated in aquifers hosting sufficiently reactive reductants that can promote autotrophic denitrification. In the case of pyrite acting as

The impact of wood biochar as a soil amendment in aerobic rice systems of the Brazilian Savannah

NARCIS (Netherlands)

Carvalho, M.T.M.

2015-01-01

Abstract

Keywords: tropical Savannah, biochar, soil fertility, aerobic rice, grain yield, N2O emission

Márcia Thaís de Melo Carvalho (2015). The impact of wood biochar as a soil amendment in aerobic rice systems of the Brazilian Savannah. PhD thesis,

Watershed modeling at the Savannah River Site.

Energy Technology Data Exchange (ETDEWEB)

Vache, Kellie [Oregon State University

2015-04-29

The overall goal of the work was the development of a watershed scale model of hydrological function for application to the US Department of Energy’s (DOE) Savannah River Site (SRS). The primary outcomes is a grid based hydrological modeling system that captures near surface runoff as well as groundwater recharge and contributions of groundwater to streams. The model includes a physically-based algorithm to capture both evaporation and transpiration from forestland.

Advective and diffusive contributions to reactive gas transport during pyrite oxidation in the unsaturated zone

NARCIS (Netherlands)

Binning, P. J.; POSTMA, D; Russell, T. F.; Wesselingh, J. A.; Boulin, P. F.

2007-01-01

[1] Pyrite oxidation in unsaturated mine waste rock dumps and soils is limited by the supply of oxygen from the atmosphere. In models, oxygen transport through the subsurface is often assumed to be driven by diffusion. However, oxygen comprises 23.2% by mass of dry air, and when oxygen is consumed

Decision support system for optimally managing water resources to meet multiple objectives in the Savannah River Basin

Science.gov (United States)

Roehl, Edwin A.; Conrads, Paul

2015-01-01

Managers of large river basins face conflicting demands for water resources such as wildlife habitat, water supply, wastewater assimilative capacity, flood control, hydroelectricity, and recreation. The Savannah River Basin, for example, has experienced three major droughts since 2000 that resulted in record low water levels in its reservoirs, impacting dependent economies for years. The Savannah River estuary contains two municipal water intakes and the ecologically sensitive freshwater tidal marshes of the Savannah National Wildlife Refuge. The Port of Savannah is the fourth busiest in the United States, and modifications to the harbor to expand ship traffic since the 1970s have caused saltwater to migrate upstream, reducing the freshwater marsh’s acreage more than 50 percent. A planned deepening of the harbor includes flow-alteration features to minimize further migration of salinity, whose effectiveness will only be known after all construction is completed.One of the challenges of large basin management is the optimization of water use through ongoing regional economic development, droughts, and climate change. This paper describes a model of the Savannah River Basin designed to continuously optimize regulated flow to meet prioritized objectives set by resource managers and stakeholders. The model was developed from historical data using machine learning, making it more accurate and adaptable to changing conditions than traditional models. The model is coupled to an optimization routine that computes the daily flow needed to most efficiently meet the water-resource management objectives. The model and optimization routine are packaged in a decision support system that makes it easy for managers and stakeholders to use. Simulation results show that flow can be regulated to substantially reduce salinity intrusions in the Savannah National Wildlife Refuge, while conserving more water in the reservoirs. A method for using the model to assess the effectiveness of

SAVANNAH RIVER ENVIRONMENTAL REPORT FOR 2006

International Nuclear Information System (INIS)

Mamatey, A

2007-01-01

The ''Savannah River Site Environmental Report for 2006'' (WSRC-TR-2007-00008) is prepared for the U.S. Department of Energy (DOE) according to requirements of DOE Order 231.1A, ''Environment, Safety and Health Reporting'', and DOE Order 5400.5, ''Radiation Protection of the Public and Environment''. The report's purpose is to: present summary environmental data that characterize site environmental management performance; confirm compliance with environmental standards and requirements; highlight significant programs and efforts; and assess the impact of SRS operations on the public and the environment

Acid mine drainage in the Iberian Pyrite Belt: 1. Hydrochemical characteristics and pollutant load of the Tinto and Odiel rivers.

Science.gov (United States)

Nieto, Jose M; Sarmiento, Aguasanta M; Canovas, Carlos R; Olias, Manuel; Ayora, Carlos

2013-11-01

Acid mine drainage in the Iberian Pyrite Belt is probably the worst case in the world of surface water pollution associated with mining of sulphide mineral deposits. The Iberian Pyrite Belt is located in SW Iberian Peninsula, and it has been mined during the last 4,500 years. The central and eastern part of the Iberian Pyrite Belt is drained by the Tinto and Odiel rivers, which receive most of the acidic leachates from the mining areas. As a result, the main channels of the Tinto and Odiel rivers are very rich in metals and highly acidic until reaching the Atlantic Ocean. A significant amount of the pollutant load transported by these two rivers is delivered during the rainy season, as is usual in rivers of Mediterranean climate regions. Therefore, in order to have an accurate estimation of the pollutant loads transported by the Tinto and Odiel rivers, a systematic sampling on a weekly basis and a high temporal resolution sampling of floods events were both performed. Results obtained show that metal fluxes are strongly dependent on the study period, highlighting the importance of inter-annual studies involving dry and wet years.

Assessment of plutonium in the Savannah River Site environment. Revision 1

Energy Technology Data Exchange (ETDEWEB)

Carlton, W.H.; Evans, A.G.; Geary, L.A.; Murphy, C.E. Jr.; Pinder, J.E.; Strom, R.N.

1992-12-31

Plutonium in the Savannah River Site Environment is published as a part of the Radiological Assessment Program (RAP). It is the fifth in a series of eight documents on individual radioisotopes released to the environment as a result of Savannah River Site (SRS) operations. These are living documents, each to be revised and updated on a two-year schedule. This document describes the sources of plutonium in the environment, its release from SRS, environmental transport and ecological concentration of plutonium, and the radiological impact of SRS releases to the environment. Plutonium exists in the environment as a result of above-ground nuclear weapons tests, the Chernobyl accident, the destruction of satellite SNAP 9-A, plane crashes involving nuclear weapons, and small releases from reactors and reprocessing plants. Plutonium has been produced at SRS during the operation of five production reactors and released in small quantities during the processing of fuel and targets in chemical separations facilities. Approximately 0.6 Ci of plutonium was released into streams and about 12 Ci was released to seepage basins, where it was tightly bound by clay in the soil. A smaller quantity, about 3.8 Ci, was released to the atmosphere. Virtually all releases have occurred in F- and H-Area separation facilities. Plutonium concentration and transport mechanisms for the atmosphere, surface water, and ground water releases have been extensively studied by Savannah River Technology Center (SRTC) and ecological mechanisms have been studied by Savannah River Ecology Laboratory (SREL). The overall radiological impact of SRS releases to the offsite maximum individual can be characterized by a total dose of 15 mrem (atmospheric) and 0.18 mrem (liquid), compared with the dose of 12,960 mrem from non-SRS sources during the same period of time (1954--1989). Plutonium releases from SRS facilities have resulted in a negligible impact to the environment and the population it supports.

Assessing Pyrite-Derived Sulfate in the Mississippi River with Four Years of Sulfur and Triple-Oxygen Isotope Data.

Science.gov (United States)

Killingsworth, Bryan A; Bao, Huiming; Kohl, Issaku E

2018-05-17

Riverine dissolved sulfate (SO 4 2- ) sulfur and oxygen isotope variations reflect their controls such as SO 4 2- reduction and reoxidation, and source mixing. However, unconstrained temporal variability of riverine SO 4 2- isotope compositions due to short sampling durations may lead to mischaracterization of SO 4 2- sources, particularly for the pyrite-derived sulfate load. We measured the sulfur and triple-oxygen isotopes (δ 34 S, δ 18 O, and Δ' 17 O) of Mississippi River SO 4 2- with biweekly sampling between 2009 and 2013 to test isotopic variability and constrain sources. Sulfate δ 34 S and δ 18 O ranged from -6.3‰ to -0.2‰ and -3.6‰ to +8.8‰, respectively. Our sampling period captured the most severe flooding and drought in the Mississippi River basin since 1927 and 1956, respectively, and a first year of sampling that was unrepresentative of long-term average SO 4 2- . The δ 34 S SO4 data indicate pyrite-derived SO 4 2- sources are 74 ± 10% of the Mississippi River sulfate budget. Furthermore, pyrite oxidation is implicated as the dominant process supplying SO 4 2- to the Mississippi River, whereas the Δ' 17 O SO4 data shows 18 ± 9% of oxygen in this sulfate is sourced from air O 2 .

Probabilities of Natural Events Occurring at Savannah River Plant

Energy Technology Data Exchange (ETDEWEB)

Huang, J.C.

2001-07-17

This report documents the comprehensive evaluation of probability models of natural events which are applicable to Savannah River Plant. The probability curves selected for these natural events are recommended to be used by all SRP/SRL safety analysts. This will ensure a consistency in analysis methodology for postulated SAR incidents involving natural phenomena.

Actinide-soil interactions in waste management at the Savannah River Plant

International Nuclear Information System (INIS)

Holcomb, H.P.; Horton, J.H.; Wilhite, E.L.

1976-01-01

Three aspects of the transuranium (TRU) nuclide-soil interaction were studied in connection with Savannah River Plant (SRP) burial ground operations. Results of the studies are reported as three separate parts of this report

Formation of carbonate pipes in the northern Okinawa Trough linked to strong sulfate exhaustion and iron supply

Science.gov (United States)

Peng, Xiaotong; Guo, Zixiao; Chen, Shun; Sun, Zhilei; Xu, Hengchao; Ta, Kaiwen; Zhang, Jianchao; Zhang, Lijuan; Li, Jiwei; Du, Mengran

2017-05-01

The microbial anaerobic oxidation of methane (AOM), a key biogeochemical process that consumes substantial amounts of methane produced in seafloor sediments, can lead to the formation of carbonate deposits at or beneath the sea floor. Although Fe oxide-driven AOM has been identified in cold seep sediments, the exact mode by which it may influence the formation of carbonate deposits remains poorly understood. Here, we characterize the morphology, petrology and geochemistry of a methane-derived Fe-rich carbonate pipe in the northern Okinawa Trough (OT). We detect abundant authigenic pyrites, as well as widespread trace Fe, within microbial mat-like carbonate veins in the pipe. The in situ δ34S values of these pyrites range from -3.9 to 31.6‰ (VCDT), suggesting a strong consumption of seawater sulfate by sulfate-driven AOM at the bottom of sulfate reduction zone. The positive δ56Fe values of pyrite and notable enrichment of Fe in the OT pipe concurrently indicate that the pyrites are primarily derived from Fe oxides in deep sediments. We propose that the Fe-rich carbonate pipe formed at the bottom of sulfate reduction zone, below which Fe-driven AOM, rather than Fe-oxide reduction coupled to organic matter degradation, might be responsible for the abundantly available Fe2+ in the fluids from which pyrites precipitated. The Fe-rich carbonate pipe described in this study probably represents the first fossil example of carbonate deposits linked to Fe-driven AOM. Because Fe-rich carbonate deposits have also been found at other cold seeps worldwide, we infer that similar processes may play an essential role in biogeochemical cycling of sub-seafloor methane and Fe at continental margins.

Climatology of the Savannah River Plant site

International Nuclear Information System (INIS)

Hoel, D.D.

1983-01-01

This document is intended as a reference for those involved in environmental research, and preparing environmental and safety analysis reports about aspects of operations of production and support facilities at the Savannah River Plant (SRP). The information in this document is drawn from appropriate references and from the extensive meteorological data base collected on SRP. This document contains information on the climatological characteristics of the SRP site, as well as information on relative concentrations and deposition for specific radionuclides

The potential use of storm water and effluent from a constructed wetland for re-vegetating a degraded pyrite trail in Queen Elizabeth National Park, Uganda

Science.gov (United States)

Osaliya, R.; Kansiime, F.; Oryem-Origa, H.; Kateyo, E.

During the operation of the Kilembe Mines (copper mining) a cobaltiferous stockpile was constructed, which began to erode after the closure of the mines in the early 1970s. The erosion of the pyrite stockpile resulted in a large acid trail all the way to Lake George (a Ramsar site). The acid trail contaminated a large area of Queen Elizabeth National Park (QENP) resulting in the death of most of the shallow-rooted vegetation. Processes and conditions created by storm water and effluent from a constructed wetland were assessed for vegetation regeneration in the degraded QENP pyrite trail. Cynodon dactylon, Imperata cylindrica and Hyparrhenia filipendula dominated the regeneration zone (RZ) where storm water and effluent from a constructed wetland was flowing; and the adjacent unpolluted area (UP) with importance value indices of 186.4 and 83.3 respectively. Typha latifolia and C. dactylon formed two distinct vegetation sub-zones within the RZ with the former inhabiting areas with a higher water table. Soil pH was significantly higher in the RZ, followed by UP and bare pyrite trail (BPT) at both 0-15 cm and 16-30 cm depths. Soil electrical conductivity was not significantly different in the RZ and BPT but significantly higher than that in UP for both depths. For 0-15 cm depth, RZ had significantly higher concentrations of copper than BPT and UP which had similar concentrations. Still at this depth (0-15 cm), the unpolluted area had significantly higher concentrations of total phosphorus and total nitrogen than the regeneration zone and the bare pyrite trail which had similar concentrations. The RZ dominated by Typha had significantly higher concentrations of TP and TN compared to the RZ dominated by Cynodon. The concentrations of NH 4-N were significantly lower in Typha regeneration zone than in CRZ at 0-15 cm depth but similar at 16-30 cm depth. At 16-30 cm depth, concentrations of copper were significantly higher in the regeneration zone followed by the bare pyrite

Putting radiation in perspective. Appendix A. Savannah River Chapter, Health Physics Society, public lecture

International Nuclear Information System (INIS)

Cofer, C.H.

1981-06-01

The Savannah River Chapter of the Health Physics Society has prepared and presented lectures to more than 20 civic groups in the Central Savannah River Area during the last half of 1980. The purpose of the lectures is to improve public understanding of the risks associated with ionizing radiation. Methods of preparation and presentation of the lectures are discussed along with methods used to obtain speaking invitations. Excerpts from the lectures, response to the lectures, and some typical questions from the question and answer sessions are also included

FORTRAN computer programs to process Savannah River Laboratory hydrogeochemical and stream-sediment reconnaissance data

International Nuclear Information System (INIS)

Zinkl, R.J.; Shettel, D.L. Jr.; D'Andrea, R.F. Jr.

1980-03-01

FORTRAN computer programs have been written to read, edit, and reformat the hydrogeochemical and stream-sediment reconnaissance data produced by Savannah River Laboratory for the National Uranium Resource Evaluation program. The data are presorted by Savannah River Laboratory into stream sediment, ground water, and stream water for each 1 0 x 2 0 quadrangle. Extraneous information is eliminated, and missing analyses are assigned a specific value (-99999.0). Negative analyses are below the detection limit; the absolute value of a negative analysis is assumed to be the detection limit

Remote video radioactive systems evaluation, Savannah River Site

International Nuclear Information System (INIS)

Heckendorn, F.M.; Robinson, C.W.

1991-01-01

Specialized miniature low cost video equipment has been effectively used in a number of remote, radioactive, and contaminated environments at the Savannah River Site (SRS). The equipment and related techniques have reduced the potential for personnel exposure to both radiation and physical hazards. The valuable process information thus provided would not have otherwise been available for use in improving the quality of operation at SRS

Assessment of mercury in the Savannah River Site environment

Energy Technology Data Exchange (ETDEWEB)

Kvartek, E.J.; Carlton, W.H.; Denham, M.; Eldridge, L.; Newman, M.C.

1994-09-01

Mercury has been valued by humans for several millennia. Its principal ore, cinnabar, was mined for its distinctive reddish-gold color and high density. Mercury and its salts were used as medicines and aphrodisiacs. At SRS, mercury originated from one of the following: as a processing aid in aluminum dissolution and chloride precipitation; as part of the tritium facilities` gas handling system; from experimental, laboratory, or process support facilities; and as a waste from site operations. Mercury is also found in Par Pond and some SRS streams as the result of discharges from a mercury-cell-type chlor-alkali plant near the city of Augusta, GA. Reactor cooling water, drawn from the Savannah River, transported mercury onto the SRS. Approximately 80,000 kg of mercury is contained in the high level waste tanks and 10,000 kg is located in the SWDF. Additional quantities are located in the various seepage basins. In 1992, 617 wells were monitored for mercury contamination, with 47 indicating contamination in excess of the 0.002-ppm EPA Primary Drinking Water Standard. More than 20 Savannah River Ecology Laboratory (SREL) reports and publications pertinent to mercury (Hg) have been generated during the last two decades. They are divided into three groupings: SRS-specific studies, basic studies of bioaccumulation, and basic studies of effect. Many studies have taken place at Par Pond and Upper Three Runs Creek. Mercury has been detected in wells monitoring the groundwater beneath SRS, but not in water supply wells in excess of the Primary Drinking Water Limit of 0.002 ppm. There has been no significant release of mercury from SRS to the Savannah River. While releases to air are likely, based on process knowledge, modeling of the releases indicates concentrations that are well below the SCDHEC ambient standard.

Assessment of mercury in the Savannah River Site environment

International Nuclear Information System (INIS)

Kvartek, E.J.; Carlton, W.H.; Denham, M.; Eldridge, L.; Newman, M.C.

1994-09-01

Mercury has been valued by humans for several millennia. Its principal ore, cinnabar, was mined for its distinctive reddish-gold color and high density. Mercury and its salts were used as medicines and aphrodisiacs. At SRS, mercury originated from one of the following: as a processing aid in aluminum dissolution and chloride precipitation; as part of the tritium facilities' gas handling system; from experimental, laboratory, or process support facilities; and as a waste from site operations. Mercury is also found in Par Pond and some SRS streams as the result of discharges from a mercury-cell-type chlor-alkali plant near the city of Augusta, GA. Reactor cooling water, drawn from the Savannah River, transported mercury onto the SRS. Approximately 80,000 kg of mercury is contained in the high level waste tanks and 10,000 kg is located in the SWDF. Additional quantities are located in the various seepage basins. In 1992, 617 wells were monitored for mercury contamination, with 47 indicating contamination in excess of the 0.002-ppm EPA Primary Drinking Water Standard. More than 20 Savannah River Ecology Laboratory (SREL) reports and publications pertinent to mercury (Hg) have been generated during the last two decades. They are divided into three groupings: SRS-specific studies, basic studies of bioaccumulation, and basic studies of effect. Many studies have taken place at Par Pond and Upper Three Runs Creek. Mercury has been detected in wells monitoring the groundwater beneath SRS, but not in water supply wells in excess of the Primary Drinking Water Limit of 0.002 ppm. There has been no significant release of mercury from SRS to the Savannah River. While releases to air are likely, based on process knowledge, modeling of the releases indicates concentrations that are well below the SCDHEC ambient standard

The Savannah River Site's Groundwater Monitoring Program

Energy Technology Data Exchange (ETDEWEB)

1992-08-03

This report summarizes the Savannah River Site (SRS) groundwater monitoring program conducted during the first quarter of 1992. It includes the analytical data, field data, data review, quality control, and other documentation for this program; provides a record of the program's activities; and serves as an official document of the analytical results.

Scrubbing Up: Multi-Scale Investigation of Woody Encroachment in a Southern African Savannah

Directory of Open Access Journals (Sweden)

Christopher G. Marston

2017-04-01

Full Text Available Changes in the extent of woody vegetation represent a major conservation question in many savannah systems around the globe. To address the problem of the current lack of broad-scale cost-effective tools for land cover monitoring in complex savannah environments, we use a multi-scale approach to quantifying vegetation change in Kruger National Park (KNP, South Africa. We test whether medium spatial resolution satellite data (Landsat, existing back to the 1970s, which have pixel sizes larger than typical vegetation patches, can nevertheless capture the thematic detail required to detect woody encroachment in savannahs. We quantify vegetation change over a 13-year period in KNP, examine the changes that have occurred, assess the drivers of these changes, and compare appropriate remote sensing data sources for monitoring change. We generate land cover maps for three areas of southern KNP using very high resolution (VHR and medium resolution satellite sensor imagery from February 2001 to 2014. Considerable land cover change has occurred, with large increases in shrubs replacing both trees and grassland. Examination of exclosure areas and potential environmental driver data suggests two mechanisms: elephant herbivory removing trees and at least one separate mechanism responsible for conversion of grassland to shrubs, theorised to be increasing atmospheric CO2. Thus, the combination of these mechanisms causes the novel two-directional shrub encroachment that we observe (tree loss and grassland conversion. Multi-scale comparison of classifications indicates that although spatial detail is lost when using medium resolution rather than VHR imagery for land cover classification (e.g., Landsat imagery cannot readily distinguish between tree and shrub classes, while VHR imagery can, the thematic detail contained within both VHR and medium resolution classifications is remarkably congruent. This suggests that medium resolution imagery contains sufficient

Technology implementation and cleanup progress at Savannah River site

International Nuclear Information System (INIS)

Papouchado, L.M.

1996-01-01

The integrated high level waste treatment system at Savannah River has started up and the process of converting 34 million gallons of liquid waste to glass and saltstone is in its initial phase. New waste disposal vaults and startup of several other facilities such as the Consolidated Incinerator Facility and a mixed waste vitrification facility will help completion of the integrated system to treat and dispose of SRS wastes. Technology was utilized from industry, other laboratories, or was developed at the Savannah River Technology Center if it was not available. Many SRTC developments involved academia and other labs. SRS also has over 400 waste sites (400 acres) in its characterization/remediation program. To date over 90 acres were remediated (23 percent) and by 1997 we plan to remediate 175 acres or 44 percent. Thirteen groundwater facility treatment sites will be in operation by 1997. SRS has provided and continues to provide unique test platforms for testing innovative remediation, characterization and monitoring technologies. We are currently testing DNAPL characterization and remediation and an in-situ Inorganic remediation technique for ground water

Risk assessment data banks at the Savannah River Site

International Nuclear Information System (INIS)

Townsend, C.S.; Durant, W.S.; Baughman, D.F.

1993-01-01

In the risk assessment business, it is a well known fact that past mistakes will not be remembered if nothing is done to record them and make them available for future reference and review. The Savannah River Site maintains a computer database system for nonreactor facilities that contains a compilation of the incidents that have occurred since the start up of the Site in 1953. The nationally recognized data banks are highly valued across the US Department of Energy (DOE) complex for their use in risk-related analyses. They provide data for uses such as failure rate analyses, equipment reliability and breakdown studies, project justification, incident investigations, design studies, Safety Analysis Reports, Process Hazards Reviews, consequence analyses, quality assurance studies, trend analyses, management decision, administrative control effectiveness studies, and process problem solving. Five risk assessment data banks exist in the areas of reprocessing, fuel fabrication, waste management, tritium, and the Savannah River Technology Center. The data banks are comprised of approximately one-third million entries collectively and continue to grow at a rate of about two hundred entries per day

Radiological/toxicological sabotage assessments at the Savannah River Site

International Nuclear Information System (INIS)

Johnson, H.D.; Pascal, M.D.; Richardson, D.L.

1995-01-01

This paper describes the methods being employed by Westinghouse Savannah River Company (WSRC) to perform graded assessments of radiological and toxicological sabotage vulnerability at Savannah River Site (SRS) facilities. These assessments are conducted to ensure that effective measures are in place to prevent, mitigate, and respond to a potential sabotage event which may cause an airborne release of radiological/toxicological material, causing an adverse effect on the health and safety of employees, the public, and the environment. Department of Energy (DOE) Notice 5630.3A, open-quotes Protection of Departmental Facilities Against Radiological and Toxicological Sabotage,close quotes and the associated April 1993 DOE-Headquarters guidance provide the requirements and outline an eight-step process for hazardous material evaluation. The process requires the integration of information from a variety of disciplines, including safety, safeguards and security, and emergency preparedness. This paper summarizes WSRC's approach towards implementation of the DOE requirements, and explains the inter-relationships between the Radiological and Toxicological Assessments developed using this process, and facility Hazard Assessment Reports (HAs), Safety Analysis Reports (SARs), and Facility Vulnerability Assessments (VAs)

Cost effectiveness of in situ bioremediation at Savannah River

International Nuclear Information System (INIS)

Saaty, R.P.; Showalter, W.E.; Booth, S.R.

1995-01-01

In situ bioremediation (ISBR) is an innovative new remediation technology for the removal of chlorinated solvents from contaminated soils and groundwater. The principal contaminant at the Savannah River Integrated Demonstration is tricloroethylene (TCE) a volatile organic compound (VOC). A 384-day test run at Savannah River, sponsored by the US Department of Energy (DOE), Office of Technology Development (EM-50), furnished information about the performance and applications of ISBR. In situ bioremediation, as tested, is based on two distinct processes occurring simultaneously; the physical process of in situ air stripping and the biological process of bioremediation. Both processes have the potential to remediate some amount of contamination. A quantity of VOCs, directly measured from the extracted airstream, was removed from the test area by the physical process of air stripping. The biological process is difficult to examine. However, the results of several tests performed at the SRID and independent numerical modeling determined that the biological process remediated an additional 40% above the physical process. Given these data, the cost effectiveness of this new technology can be evaluated

A multi-radioisotope approach to dating sedimentation : applying Re-Os organic-rich shale and U-Pb authigenic xenotime dating to the Shannon and Pennine Basins

OpenAIRE

Stanislawska, Maja Anna

2013-01-01

Sedimentary rocks are the most abundant hthologies on the Earth, covering over 70% of the planet’s surface. Quantitative dating of sedimentary rocks (especially those devoid of fossils) is critical to understanding the past events and rates and duration of processes that shaped the Earth. Recent advances in geochronology of sedimentary rocks, such as Re-Os dating of organic-rich shales and U-Pb dating of authigenic xenotime, allow precise depositional and early diagenetic ages to be obtained,...

Land and water use characteristics in the vicinity of the Savannah River Site

Energy Technology Data Exchange (ETDEWEB)

Hamby, D.M.

1991-03-01

Routine operations at the Savannah River Site (SRS) result in the release of small amounts of radionuclides to the atmosphere and to the Savannah River. The resulting radiological doses to the offsite maximum individual and the offsite population within 50 miles of the SRS are estimated on a yearly basis. These estimates are generated using dose models prescribed for the commercial nuclear power industry by the Nuclear Regulatory Commission (NRC). The NRC provides default values for dose model parameters for facilities not having enough data to develop site-specific values. A survey of land and water use characteristics for the Savannah River area has been conducted to determine as many site-specific values as possible for inclusion in the dose models used at the SRS. These site parameters include local characteristics of meat, milk, and vegetable production; river recreational activities; and meat, milk, and vegetable consumption rates. The report that follows describes the origin of the NRC default values, the methodology for deriving regional data, the results of the study, and the derivations of region-specific usage and consumption rates. 33 refs., 3 figs., 8 tabs.

The uraninite-pyrite association, a sensitive indicator of changes in fluid chemistry: element gains and losses

Czech Academy of Sciences Publication Activity Database

Zachariáš, J.; Adamovič, Jiří; Konečný, P.

2008-01-01

Roč. 46, č. 5 (2008), s. 1159-1172 ISSN 0008-4476 R&D Projects: GA AV ČR IAA3013302 Institutional research plan: CEZ:AV0Z30130516 Keywords : uraninite * chemical age, * arsenian pyrite * silicification * fluid chemistry Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.136, year: 2008

Genetic Evidence for Contrasting Wetland and Savannah Habitat Specializations in Different Populations of Lions (Panthera leo).

Science.gov (United States)

Moore, Andy E; Cotterill, Fenton P D Woody; Winterbach, Christiaan W; Winterbach, Hanlie E K; Antunes, Agostinho; O'Brien, Stephen J

2016-03-01

South-central Africa is characterized by an archipelago of wetlands, which has evolved in time and space since at least the Miocene, providing refugia for animal species during Pleistocene arid episodes. Their importance for biodiversity in the region is reflected in the evolution of a variety of specialist mammal and bird species, adapted to exploit these wetland habitats. Populations of lions (Panthera leo) across south-central and east Africa have contrasting signatures of mitochondrial DNA haplotypes and biparental nuclear DNA in wetland and savannah habitats, respectively, pointing to the evolution of distinct habitat preferences. This explains the absence of genetic admixture of populations from the Kalahari savannah of southwest Botswana and the Okavango wetland of northern Botswana, despite separation by only 500 km. We postulate that ancestral lions were wetland specialists and that the savannah lions evolved from populations that were isolated during arid Pleistocene episodes. Expansion of grasslands and the resultant increase in herbivore populations during mesic Pleistocene climatic episodes provided the stimulus for the rapid population expansion and diversification of the highly successful savannah lion specialists. Our model has important implications for lion conservation. © The American Genetic Association 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Sedimentary phosphorus and iron cycling in and below the oxygen minimum zone of the northern Arabian Sea

Directory of Open Access Journals (Sweden)

P. Kraal

2012-07-01

Full Text Available In this study, we investigate phosphorus (P and iron (Fe cycling in sediments along a depth transect from within to well below the oxygen minimum zone (OMZ in the northern Arabian Sea (Murray Ridge. Pore-water and solid-phase analyses show that authigenic formation of calcium phosphate minerals (Ca-P is largely restricted to where the OMZ intersects the seafloor topography, likely due to higher depositional fluxes of reactive P. Nonetheless, increased ratios of organic carbon to organic P (C_org/P_org and to total reactive P (C_org/P_reactive in surface sediments indicate that the overall burial efficiency of P relative to C_org decreases under the low bottom water oxygen concentrations (BWO in the OMZ. The relatively constant Fe/Al ratio in surface sediments along the depth transect suggest that corresponding changes in Fe burial are limited. Sedimentary pyrite contents are low throughout the ~25 cm sediment cores at most stations, as commonly observed in the Arabian Sea OMZ. However, pyrite is an important sink for reactive Fe at one station in the OMZ. A reactive transport model (RTM was applied to quantitatively investigate P and Fe diagenesis at an intermediate station at the lower boundary of the OMZ (bottom water O₂: ~14 μmol L⁻¹. The RTM results contrast with earlier findings in showing that Fe redox cycling can control authigenic apatite formation and P burial in Arabian Sea sediment. In addition, results suggest that a large fraction of the sedimentary Ca-P is not authigenic, but is instead deposited from the water column and buried. Dust is likely a major source of this Ca-P. Inclusion of the unreactive Ca-P pool in the C_org/P ratio leads to an overestimation of the burial efficiency of reactive P relative to C_org along the depth transect. Moreover, the unreactive Ca-P accounts for ~85% of total Ca-P burial. In general, our results reveal

Aerial radiological surveys of Steed Pond, Savannah River Site: Dates of surveys, 1984--1989

International Nuclear Information System (INIS)

Fritzsche, A.E.; Jobst, J.E.

1993-09-01

From June 1984 to August 1985, three aerial radiological surveys were conducted over Steed Pond at the Savannah River Site in South Carolina. In addition, Steed Pond was included in larger-area surveys of the Savannah River Site in subsequent years. The surveys were conducted by the Remote Sensing Laboratory of EG ampersand G Energy Measurements, Inc., Las Vegas, Nevada, for the US Department of Energy. Airborne measurements were obtained for both natural and man-made gamma radiation over Steed Pond and surrounding areas. The first survey was conducted when the pond was filled to normal capacity for the time of the year. On September 1, 1984, the Steed Pond dam spillway failed causing the pond to drain. The four subsequent surveys were conducted with the pond drained. The second survey and the third were conducted to study silt deposits exposed by the drop in water level after the spillway's opening. Steed Pond data from the February 1987 and April 1989 Savannah River Site surveys have been included to bring this study up to date

Radiological impact of 2016 operations at the Savannah River Site

Energy Technology Data Exchange (ETDEWEB)

Minter, K. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Jannik, G. T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Dixon, K. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-06-01

This report presents the environmental dose assessment methods and the estimated potential doses to the offsite public from 2016 Savannah River Site (SRS) air and liquid radioactive releases. Also documented are potential doses from special-case exposure scenarios, such as the consumption of wildlife or goat milk.

The Savannah River Site's groundwater monitoring program

Energy Technology Data Exchange (ETDEWEB)

1991-10-18

This report summarizes the Savannah River Site (SRS) groundwater monitoring program conducted by EPD/EMS in the first quarter of 1991. In includes the analytical data, field data, data review, quality control, and other documentation for this program, provides a record of the program's activities and rationale, and serves as an official document of the analytical results.

Impacts of glycolate and formate radiolysis and thermolysis on hydrogen generation rate calculations for the Savannah River Site tank farm

Energy Technology Data Exchange (ETDEWEB)

Crawford, C. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); King, W. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-08-14

Savannah River Remediation (SRR) personnel requested that the Savannah River National Laboratory (SRNL) evaluate available data and determine its applicability to defining the impact of planned glycolate anion additions to Savannah River Site (SRS) High Level Waste (HLW) on Tank Farm flammability (primarily with regard to H₂ production). Flammability evaluations of formate anion, which is already present in SRS waste, were also needed. This report describes the impacts of glycolate and formate radiolysis and thermolysis on Hydrogen Generation Rate (HGR) calculations for the SRS Tank Farm.

Risk assessment for nuclear processes at the Savannah River Site

International Nuclear Information System (INIS)

Durant, W.S.

1992-01-01

The Savannah River Site, one of the US Department of Energy's nuclear materials processing facilities, has for many years conducted risk-based safety analyses for the nuclear processes conducted at the facilities. This approach has allowed comparisons of risks to established criteria for acceptability. When the risk-based program was begun, it was evident that its success would depend upon having a compilation of data that was site specific. The decision was made to create a data bank of undesirable events that had occurred at the site's nuclear fuel reprocessing facilities. From this modest beginning, five data banks have been created for nuclear fuel reprocessing, waste management, nuclear fuel fabrication, tritium operations, and the Savannah River Technology Center. In addition to the primary purpose of providing a sound basis for risk-based safety analyses, these highly versatile data banks are routinely used for equipment breakdown histories, incident investigations, design studies, project justifications, reliability studies, process problem solving, training, and audits

Ecological studies related to construction of the Defense Waste Processing Facility on the Savannah River Site

International Nuclear Information System (INIS)

Scott, D.E.; Pechmann, J.H.K.; Knox, J.N.; Estes, R.A.; McGregor, J.H.; Bailey, K.

1988-12-01

The Savannah River Ecology Laboratory has completed 10 years of ecological studies related to the construction of the Defense Waste Processing Facility (DWPF) on the Savannah River Site. This progress report examines water quality studies on streams peripheral to the DWPF construction site and examines the effectiveness of ''refuge ponds'' in ameliorating the effects of construction on local amphibians. Individual papers on these topics are indexed separately. 93 refs., 15 figs., 15 tabs

SAVANNAH RIVER ENVIRONMENTAL REPORT FOR 2006

Energy Technology Data Exchange (ETDEWEB)

Mamatey, A

2007-08-22

The ''Savannah River Site Environmental Report for 2006'' (WSRC-TR-2007-00008) is prepared for the U.S. Department of Energy (DOE) according to requirements of DOE Order 231.1A, ''Environment, Safety and Health Reporting'', and DOE Order 5400.5, ''Radiation Protection of the Public and Environment''. The report's purpose is to: present summary environmental data that characterize site environmental management performance; confirm compliance with environmental standards and requirements; highlight significant programs and efforts; and assess the impact of SRS operations on the public and the environment.

Robotics at Savannah River

International Nuclear Information System (INIS)

Byrd, J.S.

1983-01-01

A Robotics Technology Group was organized at the Savannah River Laboratory in August 1982. Many potential applications have been identified that will improve personnel safety, reduce operating costs, and increase productivity using modern robotics and automation. Several active projects are under way to procure robots, to develop unique techniques and systems for the site's processes, and to install the systems in the actual work environments. The projects and development programs are involved in the following general application areas: (1) glove boxes and shielded cell facilities, (2) laboratory chemical processes, (3) fabrication processes for reactor fuel assemblies, (4) sampling processes for separation areas, (5) emergency response in reactor areas, (6) fuel handling in reactor areas, and (7) remote radiation monitoring systems. A Robotics Development Laboratory has been set up for experimental and development work and for demonstration of robotic systems

Mobile robots in research and development programs at the Savannah River Site

International Nuclear Information System (INIS)

Martin, T.P.; Byrd, J.S.; Fisher, J.J.

1987-01-01

Savannah River Laboratory (SRL) is developing mobile robots for deployment in nuclear applications at the Savannah River Plant (SRP). Teleoperated mobile vehicles have been successfully used for several onsite applications. Development work using two research vehicles is underway to demonstrate semi-autonomous intelligent expert robot system operation in process areas. A description of the mechanical equipment, control systems, and operating modes of these vehicles is presented, including the integration of onboard sensors. A control hierarchy that uses modest computational methods is being developed at SRL to allow vehicles to autonomously navigate and perform tasks in known environments, without the need for large computer systems. Knowledge-based expert systems are being evaluated to simplify operator control, to assist in navigation functions, and to analyze sensory information

Reptiles and amphibians of the Savannah River Plant

International Nuclear Information System (INIS)

Gibbons, J.W.; Patterson, K.K.

1978-11-01

Taxonomic, distributional, and ecological information on the reptiles and amphibians of the Savannah River Plant (SRP) is provided. The purpose of such a presentation is to give a professional biologist an initial familiarity with herpetology on the SRP, and to provide sufficient comprehensive information to an ecologist, regardless of his experience in herpetology, to permit him to undertake studies that in some manner incorporate the herpetofauna of the SRP

Savannah River Site environmental restoration lessons learned program

International Nuclear Information System (INIS)

Plunkett, R.A.; Leibfarth, E.C.; Treger, T.M.; Blackmon, A.M.

1993-01-01

For the past three years environmental restoration has been formally consolidated at Savannah River Site. Accomplishments include waste site investigations to closure activities. Positive, as well as negatively impacting, events have occurred. Until recently, lessons learned were captured on a less than formal basis. Now, a program based upon critiques, evaluations and corrective actions is being used. This presentation reviews the development, implementation and use of that program

Savannah River Site Surplus Facilities Available for Reuse

International Nuclear Information System (INIS)

Clarke, R.M.; Owens, M.B.; Lentz, D.W.

1995-01-01

The purpose of this document is to provide a current, centralized list of Savannah River Site facilities, which are surplus and available for reuse. These surplus facilities may be made available for other DOE site missions, commercial economic development reuse, or other governmental reuse. SRS procedures also require that before new construction can be approved, available surplus facilities are screened for possible reuse in lieu of the proposed new construction

Pre-Shipment Preparations at the Savannah River Site

International Nuclear Information System (INIS)

Thomas, J.E.

2000-01-01

This paper will provide a detailed description of each of the pre-shipment process steps WSRC performs to produce the technical basis for approving the receipt and storage of spent nuclear fuel at the Savannah River Site. It is intended to be a guide to reactor operators who plan on returning ''U.S. origin'' SNF and to emphasize the need for accurate and timely completion of pre-shipment activities

The Savannah River Site`s Groundwater Monitoring Program, second quarter 1989

Energy Technology Data Exchange (ETDEWEB)

1989-12-31

The Environmental Monitoring Section of the Environmental and Health Protection (EHP) Department administers the Savannah River Site`s Groundwater Monitoring Program. During second quarter 1989 (April--June), EHP conducted routine sampling of monitoring wells and drinking water locations. EHP collected the drinking water samples from Savannah River Site (SRS) drinking water systems supplied by wells. EHP established two sets of flagging criteria in 1986 to assist in the management of sample results. The flagging criteria aid personnel in sample scheduling, interpretation of data, and trend identification. The flagging criteria are based on detection limits, background levels in SRS groundwater, and drinking water standards. An explanation of flagging criteria for the second quarter is presented in the Flagging Criteria section of this document. All analytical results from second quarter 1989 are listed in this report, which is distributed to all waste-site custodians.

Synergistic effect of biogenic Fe3+ coupled to S° oxidation on simultaneous bioleaching of Cu, Co, Zn and As from hazardous Pyrite Ash Waste.

Science.gov (United States)

Panda, Sandeep; Akcil, Ata; Mishra, Srabani; Erust, Ceren

2017-03-05

Pyrite ash, a waste by-product formed during roasting of pyrite ores, is a good source of valuable metals. The waste is associated with several environmental issues due to its dumping in sea and/or land filling. Although several other management practices are available for its utilization, the waste still awaits and calls for an eco-friendly biotechnological application for metal recovery. In the present study, chemolithotrophic meso-acidophilic iron and sulphur oxidisers were evaluated for the first time towards simultaneous mutli-metal recovery from pyrite ash. XRD and XRF analysis indicated higher amount of Hematite (Fe 2 O 3 ) in the sample. ICP-OES analysis indicated concentrations of Cu>Zn>Co>As that were considered for bioleaching. Optimization studies indicated Cu - 95%, Co - 97%, Zn - 78% and As - 60% recovery within 8days at 10% pulp density, pH - 1.75, 10% (v/v) inoculum and 9g/L Fe 2+ . The productivity of the bioleaching system was found to be Cu - 1696ppm/d (12% dissolution/d), Co - 338ppm/d (12.2% dissolution/d), Zn k 576ppm/d (9.8% dissolution/d) and As - 75ppm/d (7.5% dissolution/d). Synergistic actions for Fe 2+ - S° oxidation by iron and sulphur oxidisers were identified as the key drivers for enhanced metal dissolution from pyrite ash sample. Copyright © 2016 Elsevier B.V. All rights reserved.

Pollution history of the Savannah River estuary. Final report, September 1, 1976--December 31, 1977

International Nuclear Information System (INIS)

Goldberg, E.D.; Hodge, V.; Griffin, J.J.; Koide, M.; Windom, H.

1978-04-01

Records of natural and pollutant fluxes to the Savannah River Estuary are found in some river and marsh deposits into which time frames can be introduced by Pb-210 or plutonium geochronologies. Plutonium releases from the Savannah River Plant are evident in only one deposit and in marsh grass which received the transuranic element from atmospheric transport. The pollution records can be disturbed by bioturbative activities of organisms, by the input of marine solid phases to the estuarine deposits, and by river scour and fill

Savannah Forest Beekeepers in Cameroon: Actions to Reduce Vulnerability. Chapter 7

NARCIS (Netherlands)

Ingram, V.J.

2016-01-01

The savannah forests in Adamaoua, Cameroon, are home to traditional, forest-based beekeepers, subsistence farmers and pastoralists. This sparsely populated region is economically marginal and little developed, with lower than national average incomes. Forest apiculture is important here: honey,

Using Geoscience and Geostatistics to Optimize Groundwater Monitoring Networks at the Savannah River Site

International Nuclear Information System (INIS)

Tuckfield, R.C.

2001-01-01

A team of scientists, engineers, and statisticians was assembled to review the operation efficiency of groundwater monitoring networks at US Department of Energy Savannah River Site (SRS). Subsequent to a feasibility study, this team selected and conducted an analysis of the A/M area groundwater monitoring well network. The purpose was to optimize the number of groundwater wells requisite for monitoring the plumes of the principal constituent of concern, viz., trichloroethylene (TCE). The project gathered technical expertise from the Savannah River Technology Center (SRTC), the Environmental Restoration Division (ERD), and the Environmental Protection Department (EPD) of SRS

Re-Os ages for Archean molybdenite and pyrite, Kuittila-Kivisuo, Finland and Proterozoic molybdenite, Kabeliai, Lithuania: Testing the chronometer in a metamorphic and metasomatic setting

Science.gov (United States)

Stein, H.J.; Sundblad, K.; Markey, R.J.; Morgan, J.W.; Motuza, G.

1998-01-01

Seven 187Re-187Os ages were determined for molybdenite and pyrite samples from two well-dated Precambrian intrusions in Fennoscandia to examine the sustainability of the Re-Os chronometer in a metamorphic and metasomatic setting. Using a new 187Re decay constant (1.666 x 10-11y-1) with a much improved uncertainty (±0.31%), we determined replicate Re-Os ages for molybdenite and pyrite from the Kuittila and Kivisuo prospects in easternmost Finland and for molybdenite from the Kabeliai prospect in southernmost Lithuania. These two localities contain some of the oldest and youngest plutonic activity in Fennoscandia and are associated with newly discovered economic Au mineralization (Ilomantsi, Finland) and a Cu-Mo prospect (Kabeliai, Lithuania). Two Re-Os ages for veinhosted Kabeliai molybdenite average 1486 ± 5 Ma, in excellent agreement with a 1505 ± 11 Ma U-Pb zircon age for the hosting Kabeliai granite pluton. The slightly younger age suggests the introduction of Cu-Mo mineralization by a later phase of the Kabeliai magmatic system. Mean Re-Os ages of 2778 ± 8 Ma and 2781 ± 8 Ma for Kuittila and Kivisuo molybdenites, respectively, are in reasonable agreement with a 2753 ± 5 Ma weighted mean U-Pb zircon age for hosting Kuittila tonalite. These Re-Os ages agree well with less precise ages of 2789 ± 290 Ma for a Rb-Sr whole-rock isochron and 2771 ± 75 Ma for the average of six Sm-Nd T(DM) model ages for Kuittila tonalite. Three Re-Os analyses of a single pyrite mineral separate, from the same sample of Kuittila pluton that yielded a molybdenite separate, provide individual model ages of 2710 ± 27, 2777 ± 28, and 2830 ± 28 Ma (Re = 17.4, 12.1, and 8.4 ppb, respectively), with a mean value of 2770 ± 120 Ma in agreement with the Kuittila molybdenite age. The Re and 187Os abundances in these three pyrite splits are highly correlated (r = 0.9994), and provide a 187Re-187Os isochron age of 2607 ± 47 Ma with an intercept of 21 ppt 187Os (MSWD = 1.1). It appears

Metal-organic chemical vapor deposition of ultra-thin photovoltaic devices using a pyrite based p-i-n structure

Energy Technology Data Exchange (ETDEWEB)

Clayton, A.J., E-mail: andy.clayton@optictechnium.com [CSER, Glyndwr University, OpTIC Technium, St Asaph, LL17 0JD (United Kingdom); Irvine, S.J.C.; Barrioz, V.; Brooks, W.S.M. [CSER, Glyndwr University, OpTIC Technium, St Asaph, LL17 0JD (United Kingdom); Zoppi, G.; Forbes, I. [NPAC, Northumbria University, Newcastle upon Tyne, NE1 8ST (United Kingdom); Rogers, K.D.; Lane, D.W.; Hutchings, K.; Roncallo, S. [Centre for Material Science and Engineering, Cranfield University, Swindon, SN6 8LA (United Kingdom)

2011-08-31

Ultra-thin photovoltaic (PV) devices were produced by atmospheric pressure metal organic chemical vapour deposition (AP-MOCVD) incorporating a highly absorbing intermediate sulphurised FeS{sub x} layer into a CdS/CdTe structure. X-ray diffraction (XRD) confirmed a transitional phase change to pyrite FeS{sub 2} after post growth sulphur (S) annealing of the FeS{sub x} layer between 400 deg. C and 500 deg. C. Devices using a superstrate configuration incorporating a sulphurised or non-sulphurised FeS{sub x} layer were compared to p-n devices with only a CdS/CdTe structure. Devices with sulphurised FeS{sub x} layers performed least efficiently, even though pyrite fractions were present. Rutherford back scattering (RBS) confirmed deterioration of the CdS/FeS{sub x} interface due to S inter-diffusion during the annealing process.

Basement Surface Faulting and Topography for Savannah River Site and Vicinity

International Nuclear Information System (INIS)

Cumbest, R.J.

1998-01-01

This report integrates the data from more than 60 basement borings and over 100 miles of seismic reflection profiling acquired on the Savannah River Site to map the topography of the basement (unweathered rock) surface and faulting recorded on this surface

Ecological studies related to construction of the Defense Waste Processing Facility on the Savannah River Site

Energy Technology Data Exchange (ETDEWEB)

Scott, D.E.; Pechmann, J.H.K.; Knox, J.N.; Estes, R.A.; McGregor, J.H.; Bailey, K. (ed.)

1988-12-01

The Savannah River Ecology Laboratory has completed 10 years of ecological studies related to the construction of the Defense Waste Processing Facility (DWPF) on the Savannah River Site. This progress report examines water quality studies on streams peripheral to the DWPF construction site and examines the effectiveness of refuge ponds'' in ameliorating the effects of construction on local amphibians. Individual papers on these topics are indexed separately. 93 refs., 15 figs., 15 tabs. (MHB)

Population and Habitat Objectives for Avian Conservation in California’s Central Valley Grassland–Oak Savannah Ecosystems

Directory of Open Access Journals (Sweden)

Ryan T. DiGaudio

2017-03-01

Full Text Available http://escholarship.org/uc/item/0dn9f9b4In California’s Central Valley, grassland and oak savannah ecosystems provide multiple economic and social benefits, ecosystem services, and vital bird habitat. There is a growing interest in protecting, restoring, and managing these ecosystems, and the Central Valley Joint Venture (CVJV provides leadership in the formulation of conservation goals and objectives. We defined a long-term goal of protecting, restoring, and managing Central Valley grassland and oak savannah ecosystems so that they are capable of supporting genetically robust, self-sustaining, and resilient wildlife populations. To measure progress toward this goal, we selected a suite of 12 landbird focal species that primarily breed in grasslands and oak savannahs as indicators of the state of these ecosystems on the Central Valley floor (primary focus area and in the Central Valley’s surrounding foothills (secondary focus area. Using data on current densities and habitat extent, we estimated that at least three of the focal species populations in the primary focus area and at least two of the focal species populations in the secondary focus area are currently small (<10,000 individuals and may be vulnerable to extirpation. Furthermore, at least two species appear to have steeply declining population trends. We defined long-term (100-year population objectives for each focal species that we expect to meet the goal of genetically robust, self-sustaining, and resilient populations. We then estimated corresponding short-term (10-year habitat objectives of 4,183 ha of additional grassland and 3,433 ha of additional oak savannah that will be required to make progress toward the long-term objectives. We expect that habitat restoration and enhancement efforts aimed at reaching these long-term conservation objectives will result in improvements to the function of Central Valley grassland and oak savannah ecosystems.

Comprehensive cooling water study annual report. Volume II: introduction and site description, Savannah River Plant

International Nuclear Information System (INIS)

Gladden, J.B.; Lower, M.W.; Mackey, H.E.; Specht, W.L.; Wilde, E.W.

1985-07-01

The Comprehensive Cooling Water Study was initiated in 1983 to evaluate the environmental effecs of the intake and release of cooling water on the structure and function of aquatic ecosystems at the Savannah River Plant. This report presents the results from the first year of the two year study and also summarizes results from previous studies on aquatic ecosystems of the Savannah River Plant. Five major program elements are addressed: water quality, radionuclide and heavy metal transport, wetlands ecology, aquatic ecology, and endangered species. 63 refs., 13 figs., 7 tabs

Technological procedure for chemical cleaning prior to re-pyritization of H2O-H2S isotopic exchange installations

International Nuclear Information System (INIS)

Stefanescu, I.; Smaranda, D.; Titescu, Gh.

1996-01-01

In normal operation the anti-corrosive shielding of the GS installations undergo a slow, irreversible degradation in time so that after 6 - 8 years their protection characteristics break down. In order to put them back in operation the regeneration of anti-corrosive is required. The procedure achieved at ICIS - Rm.Valcea consists in chemical cleaning of the impaired layers and re-pyritization of the interior surface of installations. Chemical cleaning include the following operations: - mechanical cleaning; - water washing; - alkaline washing with sodium hydroxide, tri-sodium phosphate and sodium tri-polyphosphate; - final mechanical cleaning; - neutralizing washing; - chemical cleaning with phosphoric acid solution; - neutralizing washing. After applying this procedure, the surface is prepared for the pyritization regeneration of the anti-corrosive shielding which ensures the prolongation of the equipment service lifetime with another six year period

Savannah River Site Experiences in In Situ Field Measurements of Radioactive Materials

International Nuclear Information System (INIS)

Moore, F.S.

1999-01-01

This paper discusses some of the field gamma-ray measurements made at the Savannah River Site, the equipment used for the measurements, and lessons learned during in situ identification and characterization of radioactive materials

The Savannah River Site`s Groundwater Monitoring Program, third quarter 1991

Energy Technology Data Exchange (ETDEWEB)

1992-02-17

The Environmental Protection Department/Environmental Monitoring Section (EPD/EMS) administers the Savannah River Site`s (SRS) Groundwater Monitoring Program. During third quarter 1991, EPD/EMS conducted extensive sampling of monitoring wells. Analytical results from third quarter 1991 are listed in this report.

Savannah River Site Ingestion Pathway Methodology Manual for Airborne Radioactive Releases

Energy Technology Data Exchange (ETDEWEB)

Vincent, A.W. III

2001-01-03

This manual documents a recommended methodology for determining the ingestion pathway consequences of hypothetical accidental airborne radiological releases from facilities at the Savannah River Site. Both particulate and tritiated radioactive contaminants are addressed. Other approaches should be applied for evaluation of routine releases.

Comparison of simulated to actual plutonium deposition at the Savannah River Plant

International Nuclear Information System (INIS)

Carlson, D.C.; Garrett, A.J.; Gay, D.D.; Murphy, C.E.; Pinder, J.E. III.

1982-01-01

Minute amounts of plutonium are released from the Savannah River Plant (SRP) separations facilities and deposited in the surrounding environs. Long-term deposition measurements show that contributions to offsite environmental plutonium by the SRP are negligible compared to fallout from weapons tests. The Savannah River Laboratory (SRL) recently developed a deposition model and compared its predictions to the observed plutonium deposition pattern. The model reproduced the observed range of deposition rates when full and truncated lognormal distributions of particle sizes were used to represent the emissions. Model predictions of total deposition out to 30 km were low by about a factor of two relative to estimates based on integrations of the empirical deposition curves. More measurements are planned, which should reduce uncertainties about model assumptions and the observed deposition rates

The Savannah River Site`s Groundwater Monitoring Program, third quarter 1989

Energy Technology Data Exchange (ETDEWEB)

1989-12-31

The Environmental Monitoring Section of the Environmental and Health Protection (EHP) Department administers the Savannah River Site`s Groundwater Monitoring Program. During third quarter 1989 (July--September), EHP conducted routine sampling of monitoring wells and drinking water locations. EHP collected the drinking water samples from Savannah River Site (SRS) drinking water systems supplied by wells. EHP established two sets of flagging criteria in 1986 to assist in the management of sample results. The flagging criteria do not define contamination levels; instead they aid personnel in sample scheduling, interpretation of data, and trend identification. The flagging criteria are based on detection limits, background levels in SRS groundwater, and drinking water standards. An explanation of flagging criteria for the third quarter is presented in the Flagging Criteria section of this document. All analytical results from third quarter 1989 are listed in this report, which is distributed to all waste-site custodians.

Robotics and Automation Activities at the Savannah River Site: A Site Report for SUBWOG 39F

International Nuclear Information System (INIS)

Teese, G.D.

1995-01-01

The Savannah River Site has successfully used robots, teleoperators, and remote video to reduce exposure to ionizing radiation, improve worker safety, and improve the quality of operations. Previous reports have described the use of mobile teleoperators in coping with a high level liquid waste spill, the removal of highly contaminated equipment, and the inspection of nuclear reactor vessels. This report will cover recent applications at the Savannah River, as well as systems which SRS has delivered to other DOE site customers

Origins of mineral matter in peat marsh and peat bog deposits, Spain

Energy Technology Data Exchange (ETDEWEB)

Lopez-Buendia, A.M. [Unidad Tecnica del Marmol, AIDICO, Cami de Castella, 4, 03660 Novelda, Alicante (Spain); Whateley, M.K.G. [Rio Tinto Technical Services, Castlemead, Lower Castlemead, BS99 7YR Bristol (United Kingdom); Bastida, J.; Urquiola, M.M. [Dpto. Geologia, Univ. Valencia, Dr. Moliner 50. 46100 Burjasot, Valencia (Spain)

2007-07-02

The mineralogy of three back-barrier peat marshes (Torreblanca, Benicasim and Moncofar marshes) from Eastern Spain and one peat bog (Orihuela del Tremedal bog) from central east Spain have been investigated, using X-ray diffraction (XRD) and scanning electronic microscope (SEM) techniques. A combination of XRD methods was used to quantify the mineralogy of dried bulk peat samples. The water source in the peat marshes is both continental and marine. Water is highly mineralised. Water flow is both low and slow (accumulative system). The water source in the peat bog is continental, draining from the hill. The higher concentration of ions in the water of the back-barrier peat marshes leads to a higher concentration of authigenic minerals in the peat marshes compared to the peat bog. Three main mineral origins have been recognized, namely: detrital, syngenetic-epigenetic and biogenic. The more important contribution comes from the detrital system. Biogenic and bio-influenced minerals are the main non-detrital minerals in the peatlands. This paper discusses the biogenic origin of halite (and other minor halides and sulphates, such as, sylvite, carnalite, epsomite, glauberite, mirabilite and anhydrite?) from halophytic plants, as well as amorphous silica (opal-A) from sponge spicules and phytoliths of several plants. Pyrite in the peat bog has both syngenetic and epigenetic origins from plant decomposition and sulphur release. In the peat marsh the pyrite has a syngenetic origin from sulphate reduction (S{sub sulphate} {yields} S{sub pyritic}), and an epigenetic origin in the older peat, from plant decomposition (S{sub organic} {yields} S{sub pyritic}). (author)