WorldWideScience

Sample records for mercury sulfides

  1. Bioavailability and stability of mercury sulfide in Armuchee (USA) soil

    International Nuclear Information System (INIS)

    Han, Fengxiang; Shiyab, Safwan; Su, Yi; Monts, David L.; Waggoner, Charles A.; Matta, Frank B.

    2007-01-01

    Because of the adverse effects of elemental mercury and mercury compounds upon human health, the U.S. Department of Energy (DOE) is engaged in an on-going effort to monitor and remediate mercury-contaminated DOE sites. In order to more cost effectively implement those extensive remediation efforts, it is necessary to obtain an improved understanding of the role that mercury and mercury compounds play in the ecosystem. We have conducted pilot scale experiments to study the bioavailability of mercury sulfide in an Armuchee (eastern US ) soil. The effects of plants and incubation time on chemical stability and bioavailability of HgS under simulated conditions of the ecosystem have been examined, as has the dynamics of the dissolution of mercury sulfide by various extractants. The results show that mercury sulfide in contaminated Armuchee soil was still to some extent bioavailable to plants. After planting, soil mercury sulfide is more easily dissolved by both 4 M and 12 M nitric acid than pure mercury sulfide reagent. Dissolution kinetics of soil mercury sulfide and pure chemical reagent by nitric acid are different. Mercury release by EDTA from HgS-contaminated soil increased with time of reaction and soil mercury level. Chelating chemicals increase the solubility and bioavailability of mercury in HgS-contaminated soil. (authors)

  2. Production and Preservation of Sulfide Layering in Mercury's Magma Ocean

    Science.gov (United States)

    Boukare, C.-E.; Parman, S. W.; Parmentier, E. M.; Anzures, B. A.

    2018-05-01

    Mercury's magma ocean (MMO) would have been sulfur-rich. At some point during MMO solidification, it likely became sulfide saturated. Here we present physiochemical models exploring sulfide layer formation and stability.

  3. Formation of nanocolloidal metacinnabar in mercury-DOM-sulfide systems

    Science.gov (United States)

    Gerbig, Chase A.; Kim, Christopher S.; Stegemeier, John P.; Ryan, Joseph N.; Aiken, George R.

    2011-01-01

    Direct determination of mercury (Hg) speciation in sulfide-containing environments is confounded by low mercury concentrations and poor analytical sensitivity. Here we report the results of experiments designed to assess mercury speciation at environmentally relevant ratios of mercury to dissolved organic matter (DOM) (i.e., structure (EXAFS) spectroscopy. Aqueous Hg(II) and a DOM isolate were equilibrated in the presence and absence of 100 μM total sulfide. In the absence of sulfide, mercury adsorption to the resin increased as the Hg:DOM ratio decreased and as the strength of Hg-DOM binding increased. EXAFS analysis indicated that in the absence of sulfide, mercury bonds with an average of 2.4 ± 0.2 sulfur atoms with a bond length typical of mercury-organic thiol ligands (2.35 Å). In the presence of sulfide, mercury showed greater affinity for the C18 resin, and its chromatographic behavior was independent of Hg:DOM ratio. EXAFS analysis showed mercury–sulfur bonds with a longer interatomic distance (2.51–2.53 Å) similar to the mercury–sulfur bond distance in metacinnabar (2.53 Å) regardless of the Hg:DOM ratio. For all samples containing sulfide, the sulfur coordination number was below the ideal four-coordinate structure of metacinnabar. At a low Hg:DOM ratio where strong binding DOM sites may control mercury speciation (1.9 nmol mg–1) mercury was coordinated by 2.3 ± 0.2 sulfur atoms, and the coordination number rose with increasing Hg:DOM ratio. The less-than-ideal coordination numbers indicate metacinnabar-like species on the nanometer scale, and the positive correlation between Hg:DOM ratio and sulfur coordination number suggests progressively increasing particle size or crystalline order with increasing abundance of mercury with respect to DOM. In DOM-containing sulfidic systems nanocolloidal metacinnabar-like species may form, and these species need to be considered when addressing mercury biogeochemistry.

  4. Formation of mercury sulfide from Hg(II)−thiolate complexes in natural organic matter

    Science.gov (United States)

    Alain Manceau,; Cyprien Lemouchi,; Mironel Enescu,; Anne-Claire Gaillot,; Martine Lanson,; Valerie Magnin,; Pieter Glatzel,; Poulin, Brett; Ryan, Joseph N.; Aiken, George R.; Isabelle Gautier-Lunea,; Kathryn L. Nagy,

    2015-01-01

    Methylmercury is the environmental form of neurotoxic mercury that is biomagnified in the food chain. Methylation rates are reduced when the metal is sequestered in crystalline mercury sulfides or bound to thiol groups in macromolecular natural organic matter. Mercury sulfide minerals are known to nucleate in anoxic zones, by reaction of the thiol-bound mercury with biogenic sulfide, but not in oxic environments. We present experimental evidence that mercury sulfide forms from thiol-bound mercury alone in aqueous dark systems in contact with air. The maximum amount of nanoparticulate mercury sulfide relative to thiol-bound mercury obtained by reacting dissolved mercury and soil organic matter matches that detected in the organic horizon of a contaminated soil situated downstream from Oak Ridge, TN, in the United States. The nearly identical ratios of the two forms of mercury in field and experimental systems suggest a common reaction mechanism for nucleating the mineral. We identified a chemical reaction mechanism that is thermodynamically favorable in which thiol-bound mercury polymerizes to mercury–sulfur clusters. The clusters form by elimination of sulfur from the thiol complexes via breaking of mercury–sulfur bonds as in an alkylation reaction. Addition of sulfide is not required. This nucleation mechanism provides one explanation for how mercury may be immobilized, and eventually sequestered, in oxygenated surface environments.

  5. Use of sulfide-containing liquors for removing mercury from flue gases

    Science.gov (United States)

    Nolan, Paul S.; Downs, William; Bailey, Ralph T.; Vecci, Stanley J.

    2006-05-02

    A method and apparatus for reducing and removing mercury in industrial gases, such as a flue gas, produced by the combustion of fossil fuels, such as coal, adds sulfide ions to the flue gas as it passes through a scrubber. Ideally, the source of these sulfide ions may include at least one of: sulfidic waste water, kraft caustic liquor, kraft carbonate liquor, potassium sulfide, sodium sulfide, and thioacetamide. The sulfide ion source is introduced into the scrubbing liquor as an aqueous sulfide species. The scrubber may be either a wet or dry scrubber for flue gas desulfurization systems.

  6. Red coloration by heat treatment of the coprecipitate of cadmium sulfide and mercury(II) sulfide prepared from the nitrates

    International Nuclear Information System (INIS)

    Nakahara, Fujiya

    1979-01-01

    The effects of starting salts on the color, particle size and crystal structure of mercury-cadmium-sulfide pigments were investigated. The coprecipitate (N-S) of cadmium sulfide and mercury (II) sulfide was prepared by adding sodium sulfide solution to a mixed cadmium-mercury (II) nitrate solution. The coprecipitate (C-S) of cadmium sulfide and mercury (II) sulfide was also prepared from the mixed solution of their chlorides by the same method as described above. The coprecipitated products were heat-treated (calcination or hydrothermal treatment) at 350 0 C for 2 hours and subsequent changes in powder properties of both products were compared from each other. The powder properties of N-S, C-S and their heat-treated products were investigated by spectral reflectance, electron microscopy, X-ray diffraction and specific surface area measurements. Sample (N-C) obtained by the calcination of N-S was brown, indicating no red coloration, but the calcined product (C-C) of C-S developed a red color. Cl - and hot water were found to be effective for the red color development of the pigment. The effectiveness was confirmed by calcining N-S in the presence of NaCl or by treating it hydrothermally. It was found that halides other than NaCl, (e.g., NH 4 Cl, KCl, KBr and KI), were also effective for the color development of the pigment. The red samples are solid solutions with a basically hexagonal CdS structure, and it appears that CdS takes up HgS without any apparent structural changes. The particle size of the red samples are larger than those of the non red samples. (author)

  7. Microbial- and Thiosulfate-Mediated Dissolution of Mercury Sulfide Minerals and Transformation to Gaseous Mercury

    Directory of Open Access Journals (Sweden)

    Adiari eVázquez-Rodríguez

    2015-06-01

    Full Text Available Mercury (Hg is a toxic heavy metal that poses significant human and environmental health risks. Soils and sediments, where Hg can exist as the Hg sulfide mineral metacinnabar (β-HgS, represent major Hg reservoirs in aquatic environments. Metacinnabar has historically been considered a sink for Hg in all but severely acidic environments, and thus disregarded as a potential source of Hg back to aqueous or gaseous pools. Here, we conducted a combination of field and laboratory incubations to identify the potential for metacinnabar as a source of dissolved Hg within near neutral pH environments and the underpinning (abiotic mechanisms at play. We show that the abundant and widespread sulfur-oxidizing bacterium Thiobacillus extensively colonized metacinnabar chips incubated within aerobic, near neutral pH creek sediments. Laboratory incubations of axenic Thiobacillus cultures lead to the release of metacinnabar-hosted Hg(II and subsequent volatilization to Hg(0. This dissolution and volatilization was greatly enhanced in the presence of the sulfur intermediate, thiosulfate, which served a dual role by enhancing HgS dissolution and providing an additional metabolic substrate for Thiobacillus. These findings reveal a new coupled abiotic-biotic pathway for the transformation of metacinnabar-bound Hg(II to Hg(0, while expanding the sulfide substrates available for neutrophilic chemosynthetic bacteria to Hg-laden sulfides. They also point to mineral-hosted Hg as an underappreciated source of gaseous elemental Hg to the environment.

  8. Sulfide treatment to inhibit mercury adsorption onto activated carbon in carbon-in-pulp gold recovery circuits

    Energy Technology Data Exchange (ETDEWEB)

    Touro, F.J.; Lipps, D.A.

    1988-03-29

    A process for treating a mercury-contaminated, precious metal-containing ore slurry is described comprising: (a) reacting sulfide anions in an aqueous ore slurry of a mercury and precious metal-containing carbonaceous ore, and (b) conducting a simultaneous cyanide leach and carbon-in-pulp adsorption of the precious metal from the carbonaceous ore in the sulfide-containing ore slurry.

  9. A new mercury-accumulating Mucor hiemalis strain EH8 from cold sulfidic spring water biofilms.

    Science.gov (United States)

    Hoque, Enamul; Fritscher, Johannes

    2016-10-01

    Here, we report about a unique aquatic fungus Mucor hiemalisEH8 that can remove toxic ionic mercury from water by intracellular accumulation and reduction into elemental mercury (Hg 0 ). EH8 was isolated from a microbial biofilm grown in sulfidic-reducing spring water sourced at a Marching's site located downhill from hop cultivation areas with a history of mercury use. A thorough biodiversity survey and mercury-removal function analyses were undertaken in an area of about 200 km 2 in Bavaria (Germany) to find the key biofilm and microbe for mercury removal. After a systematic search using metal removal assays we identified Marching spring's biofilm out of 18 different sulfidic springs' biofilms as the only one that was capable of removing ionic Hg from water. EH8 was selected, due to its molecular biological identification as the key microorganism of this biofilm with the capability of mercury removal, and cultivated as a pure culture on solid and in liquid media to produce germinating sporangiospores. They removed 99% of mercury from water within 10-48 h after initial exposure to Hg(II). Scanning electron microscopy demonstrated occurrence of intracellular mercury in germinating sporangiospores exposed to mercury. Not only associated with intracellular components, but mercury was also found to be released and deposited as metallic-shiny nanospheres. Electron-dispersive x-ray analysis of such a nanosphere confirmed presence of mercury by the HgM α peak at 2.195 keV. Thus, a first aquatic eukaryotic microbe has been found that is able to grow even at low temperature under sulfur-reducing conditions with promising performance in mercury removal to safeguard our environment from mercury pollution. © 2016 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  10. Effect of Nitrogen Oxides on Elemental Mercury Removal by Nanosized Mineral Sulfide.

    Science.gov (United States)

    Li, Hailong; Zhu, Lei; Wang, Jun; Li, Liqing; Lee, Po-Heng; Feng, Yong; Shih, Kaimin

    2017-08-01

    Because of its large surface area, nanosized zinc sulfide (Nano-ZnS) has been demonstrated in a previous study to be efficient for removal of elemental mercury (Hg 0 ) from coal combustion flue gas. The excellent mercury adsorption performance of Nano-ZnS was found to be insusceptible to water vapor, sulfur dioxide, and hydrogen chloride. However, nitrogen oxides (NO X ) apparently inhibited mercury removal by Nano-ZnS; this finding was unlike those of many studies on the promotional effect of NO X on Hg 0 removal by other sorbents. The negative effect of NO X on Hg 0 adsorption over Nano-ZnS was systematically investigated in this study. Two mechanisms were identified as primarily responsible for the inhibitive effect of NO X on Hg 0 adsorption over Nano-ZnS: (1) active sulfur sites on Nano-ZnS were oxidized to inactive sulfate by NO X ; and (2) the chemisorbed mercury, i.e., HgS, was reduced to Hg 0 by NO X . This new insight into the role of NO X in Hg 0 adsorption over Nano-ZnS can help to optimize operating conditions, maximize Hg 0 adsorption, and facilitate the application of Nano-ZnS as a superior alternative to activated carbon for Hg 0 removal using existing particulate matter control devices in power plants.

  11. Increase in Nutrients, Mercury, and Methylmercury as a Consequence of Elevated Sulfate Reduction to Sulfide in Experimental Wetland Mesocosms

    Science.gov (United States)

    Myrbo, A.; Swain, E. B.; Johnson, N. W.; Engstrom, D. R.; Pastor, J.; Dewey, B.; Monson, P.; Brenner, J.; Dykhuizen Shore, M.; Peters, E. B.

    2017-11-01

    Microbial sulfate reduction (MSR) in both freshwater and marine ecosystems is a pathway for the decomposition of sedimentary organic matter (OM) after oxygen has been consumed. In experimental freshwater wetland mesocosms, sulfate additions allowed MSR to mineralize OM that would not otherwise have been decomposed. The mineralization of OM by MSR increased surface water concentrations of ecologically important constituents of OM: dissolved inorganic carbon, dissolved organic carbon, phosphorus, nitrogen, total mercury, and methylmercury. Increases in surface water concentrations, except for methylmercury, were in proportion to cumulative sulfate reduction, which was estimated by sulfate loss from the surface water into the sediments. Stoichiometric analysis shows that the increases were less than would be predicted from ratios with carbon in sediment, indicating that there are processes that limit P, N, and Hg mobilization to, or retention in, surface water. The highest sulfate treatment produced high levels of sulfide that retarded the methylation of mercury but simultaneously mobilized sedimentary inorganic mercury into surface water. As a result, the proportion of mercury in the surface water as methylmercury peaked at intermediate pore water sulfide concentrations. The mesocosms have a relatively high ratio of wall and sediment surfaces to the volume of overlying water, perhaps enhancing the removal of nutrients and mercury to periphyton. The presence of wild rice decreased sediment sulfide concentrations by 30%, which was most likely a result of oxygen release from the wild rice roots. An additional consequence of the enhanced MSR was that sulfate additions produced phytotoxic levels of sulfide in sediment pore water.

  12. Synthesis of Black and Red Mercury Sulfide Nano-Powder by Traditional Indian Method for Biomedical Application

    International Nuclear Information System (INIS)

    Padhi, Payodhar; Sahoo, G.; Das, K.; Ghosh, Sudipto; Panigrahi, S. C.

    2008-01-01

    The use of metals and minerals in the traditional Indian system of medicine known as aired is very common and is practiced since seventh century B.C. Metals were reduced to calcined powder form for medicinal purpose. For detoxification, a further step of purification of the metals and minerals with different vegetable extracts was practiced. The people of East India were using mercury and its sulfide as medicine. Gradually this secret was leaked to Arabic physicians who used mercury in skin ointment. Subsequently Italian Physicians adopted Arabic prescriptions of mercurial ointments for skin diseases. In the olden days, metals and minerals were impregnated with decoction and juice of vegetables and animal products like milk and fat for purification. These were then reduced to fine particles by milling with a pestle and mortar. It was known by then that the fineness of the powder had a significant influence on the color, texture, and medicinal properties as is cited by Charak. Nagarjun studied in detail the processing of metals and minerals, particularly mercury and the influence of the processing parameters on the medicinal values. Mercury is unique in many aspects. Indian alchemy developed a wide variety a chemical processes for the ostensible transmutation of metals and preparation of elixir of life, in which mercury occupied a prime position .The present investigation attempts to use the traditional methods as prescribed in the ancient texts to prepare mercury sulfide in both red and black form for medicinal use. XRD, SEM and HRTEM investigations of the sulfides obtained shows that the ancient Indians were able to produce nano-sized powders. Possibly this may be taken as the earliest application of the production and use of nano powder. The study proves that even in ancient time the knowledge of nano particle synthesis was prevalent and used to enhance effectiveness of medicines. Further mercury in the free form is not acceptable in medicines. The ancient

  13. Synthesis of Black and Red Mercury Sulfide Nano-Powder by Traditional Indian Method for Biomedical Application

    Science.gov (United States)

    Padhi, Payodhar; Sahoo, G.; Das, K.; Ghosh, Sudipto; Panigrahi, S. C.

    2008-10-01

    The use of metals and minerals in the traditional Indian system of medicine known as aired is very common and is practiced since seventh century B.C. Metals were reduced to calcined powder form for medicinal purpose. For detoxification, a further step of purification of the metals and minerals with different vegetable extracts was practiced. The people of East India were using mercury and its sulfide as medicine. Gradually this secret was leaked to Arabic physicians who used mercury in skin ointment. Subsequently Italian Physicians adopted Arabic prescriptions of mercurial ointments for skin diseases. In the olden days, metals and minerals were impregnated with decoction and juice of vegetables and animal products like milk and fat for purification. These were then reduced to fine particles by milling with a pestle and mortar. It was known by then that the fineness of the powder had a significant influence on the color, texture, and medicinal properties as is cited by Charak. Nagarjun studied in detail the processing of metals and minerals, particularly mercury and the influence of the processing parameters on the medicinal values. Mercury is unique in many aspects. Indian alchemy developed a wide variety a chemical processes for the ostensible transmutation of metals and preparation of elixir of life, in which mercury occupied a prime position .The present investigation attempts to use the traditional methods as prescribed in the ancient texts to prepare mercury sulfide in both red and black form for medicinal use. XRD, SEM and HRTEM investigations of the sulfides obtained shows that the ancient Indians were able to produce nano-sized powders. Possibly this may be taken as the earliest application of the production and use of nano powder. The study proves that even in ancient time the knowledge of nano particle synthesis was prevalent and used to enhance effectiveness of medicines. Further mercury in the free form is not acceptable in medicines. The ancient

  14. Rate of formation and dissolution of mercury sulfide nanoparticles: The dual role of natural organic matter

    Science.gov (United States)

    Slowey, Aaron J.

    2010-01-01

    Mercury is a global contaminant of concern due to its transformation by microorganisms to form methylmercury, a toxic species that accumulates in biological tissues. The effect of dissolved organic matter (DOM) isolated from natural waters on reactions between mercury(II) (Hg) and sulfide (S(-II)) to form HgS(s) nanoparticles across a range of Hg and S(-II) concentrations was investigated. Hg was equilibrated with DOM, after which S(-II) was added. Dissolved Hg (Hgaq) was periodically quantified using ultracentrifugation and chemical analysis following the addition of S(-II). Particle size and identity were determined using dynamic light scattering and X-ray absorption spectroscopy. S(-II) reacts with Hg to form 20 to 200nm aggregates consisting of 1-2 nm HgS(s) subunits that are more structurally disordered than metacinnabar in the presence of 2 x 10-9 to 8 x 10-6M Hg and 10 (mg C)L-1 DOM. Some of the HgS(s) nanoparticle aggregates are subsequently dissolved by DOM and (re)precipitated by S(-II) over periods of hours to days. At least three fractions of Hg-DOM species were observed with respect to reactivity toward S(-II): 0.3 μmol reactive Hg per mmol C (60 percent), 0.1 μmol per mmol C (20 percent) that are kinetically hindered, and another 0.1 μmol Hg per mmol C (20 percent) that are inert to reaction with S(-II). Following an initial S(-II)-driven precipitation of HgS(s), HgS(s) was dissolved by DOM or organic sulfur compounds. HgS(s) formation during this second phase was counterintuitively favored by lower S(-II) concentrations, suggesting surface association of DOM moieties that are less capable of dissolving HgS(s). DOM partially inhibits HgS(s) formation and mediates reactions between Hg and S(-II) such that HgS(s) is susceptible to dissolution. These findings indicate that Hg accessibility to microorganisms could be controlled by kinetic (intermediate) species in the presence of S(-II) and DOM, undermining the premise that equilibrium Hg species

  15. Partitioning of U, Th and K Between Metal, Sulfide and Silicate, Insights into the Volatile-Content of Mercury

    Science.gov (United States)

    Habermann, M.; Boujibar, A.; Righter, K.; Danielson, L.; Rapp, J.; Righter, M.; Pando, K.; Ross, D. K.; Andreasen, R.; Chidester, B.

    2016-01-01

    During the early stages of the Solar System formation, especially during the T-Tauri phase, the Sun emitted strong solar winds, which are thought to have expelled a portion of the volatile elements from the inner solar system. It is therefore usually believed that the volatile depletion of a planet is correlated with its proximity to the Sun. This trend was supported by the K/Th and K/U ratios of Venus, the Earth, and Mars. Prior to the MESSENGER mission, it was expected that Mercury is the most volatile-depleted planet. However, the Gamma Ray Spectrometer of MESSENGER spacecraft revealed elevated K/U and K/Th ratios for the surface of Mercury, much higher than previous expectations. It is possible that the K/Th and K/U ratios on the surface are not a reliable gauge of the bulk volatile content of Mercury. Mercury is enriched in sulfur and is the most reduced of the terrestrial planets, with oxygen fugacity (fO2) between IW-6.3 and IW-2.6 log units. At these particular compositions, U, Th and K behave differently and can become more siderophile or chalcophile. If significant amounts of U and Th are sequestered in the core, the apparent K/U and K/Th ratios measured on the surface may not represent the volatile budget of the whole planet. An accurate determination of the partitioning of these elements between silicate, metal, and sulfide phases under Mercurian conditions is therefore essential to better constrain Mercury's volatile content and assess planetary formation models.

  16. Mercury

    International Nuclear Information System (INIS)

    Vilas, F.; Chapman, C.R.; Matthews, M.S.

    1988-01-01

    Papers are presented on future observations of and missions to Mercury, the photometry and polarimetry of Mercury, the surface composition of Mercury from reflectance spectrophotometry, the Goldstone radar observations of Mercury, the radar observations of Mercury, the stratigraphy and geologic history of Mercury, the geomorphology of impact craters on Mercury, and the cratering record on Mercury and the origin of impacting objects. Consideration is also given to the tectonics of Mercury, the tectonic history of Mercury, Mercury's thermal history and the generation of its magnetic field, the rotational dynamics of Mercury and the state of its core, Mercury's magnetic field and interior, the magnetosphere of Mercury, and the Mercury atmosphere. Other papers are on the present bounds on the bulk composition of Mercury and the implications for planetary formation processes, the building stones of the planets, the origin and composition of Mercury, the formation of Mercury from planetesimals, and theoretical considerations on the strange density of Mercury

  17. Development of Nano-Sulfide Sorbent for Efficient Removal of Elemental Mercury from Coal Combustion Fuel Gas.

    Science.gov (United States)

    Li, Hailong; Zhu, Lei; Wang, Jun; Li, Liqing; Shih, Kaimin

    2016-09-06

    The surface area of zinc sulfide (ZnS) was successfully enlarged using nanostructure particles synthesized by a liquid-phase precipitation method. The ZnS with the highest surface area (named Nano-ZnS) of 196.1 m(2)·g(-1) was then used to remove gas-phase elemental mercury (Hg(0)) from simulated coal combustion fuel gas at relatively high temperatures (140 to 260 °C). The Nano-ZnS exhibited far greater Hg(0) adsorption capacity than the conventional bulk ZnS sorbent due to the abundance of surface sulfur sites, which have a high binding affinity for Hg(0). Hg(0) was first physically adsorbed on the sorbent surface and then reacted with the adjacent surface sulfur to form the most stable mercury compound, HgS, which was confirmed by X-ray photoelectron spectroscopy analysis and a temperature-programmed desorption test. At the optimal temperature of 180 °C, the equilibrium Hg(0) adsorption capacity of the Nano-ZnS (inlet Hg(0) concentration of 65.0 μg·m(-3)) was greater than 497.84 μg·g(-1). Compared with several commercial activated carbons used exclusively for gas-phase mercury removal, the Nano-ZnS was superior in both Hg(0) adsorption capacity and adsorption rate. With this excellent Hg(0) removal performance, noncarbon Nano-ZnS may prove to be an advantageous alternative to activated carbon for Hg(0) removal in power plants equipped with particulate matter control devices, while also offering a means of reusing fly ash as a valuable resource, for example as a concrete additive.

  18. The precipitation, growth and stability of mercury sulfide nanoparticles formed in the presence of marine dissolved organic matter.

    Science.gov (United States)

    Mazrui, Nashaat M; Seelen, Emily; King'ondu, Cecil K; Thota, Sravan; Awino, Joseph; Rouge, Jessica; Zhao, Jing; Mason, Robert P

    2018-04-25

    The methylation of mercury is known to depend on the chemical forms of mercury (Hg) present in the environment and the methylating bacterial activity. In sulfidic sediments, under conditions of supersaturation with respect to metacinnabar, recent research has shown that mercury precipitates as β-HgS(s) nanoparticles (β-HgS(s)nano). Few studies have examined the precipitation of β-HgS(s)nano in the presence of marine dissolved organic matter (DOM). In this work, we used dynamic light scattering (DLS) coupled with UV-Vis spectroscopy and transmission electron microscopy (TEM) to investigate the formation and fate of β-HgS(s)nano formed in association with marine DOM extracted from the east and west of Long Island Sound, and at the shelf break of the North Atlantic Ocean, as well as with low molecular weight thiols. We found that while the β-HgS(s)nano formed in the presence of oceanic DOM doubled in size after 5 weeks, those forming in solutions with coastal DOM did not grow over time. In addition, when the HgII : DOM ratio was varied, β-HgS(s)nano only rapidly aggregated at high ratios (>41 μmol HgII per mg C) where the concentration of thiol groups was determined to be substantially low relative to HgII. This suggests that functional groups other than thiols could be involved in the stabilization of β-HgS(s)nano. Furthermore, we showed that β-HgS(s)nano forming under anoxic conditions remained stable and could therefore persist in the environment sufficiently to impact the methylation potential. Exposure of β-HgS(s)nano to sunlit and oxic environments, however, caused rapid aggregation and sedimentation of the nanoparticles, suggesting that photo-induced changes or oxidation of organic matter adsorbed on the surface of β-HgS(s)nano affected their stability in surface waters.

  19. Mercury

    Science.gov (United States)

    Mercury is an element that is found in air, water and soil. It has several forms. Metallic mercury is a shiny, silver-white, odorless liquid. If ... with other elements to form powders or crystals. Mercury is in many products. Metallic mercury is used ...

  20. Experimental Behavior of Sulfur Under Primitive Planetary Differentiation Processes, the Sulfide Formations in Enstatite Meteorites and Implications for Mercury.

    Science.gov (United States)

    Malavergne, V.; Brunet, F.; Righter, K.; Zanda, B.; Avril, C.; Borensztajn, S.; Berthet, S.

    2012-01-01

    Enstatite meteorites are the most reduced naturally-occuring materials of the solar system. The cubic monosulfide series with the general formula (Mg,Mn,Ca,Fe)S are common phases in these meteorite groups. The importance of such minerals, their formation, composition and textural relationships for understanding the genesis of enstatite chondrites (EC) and aubrites, has long been recognized (e.g. [1]). However, the mechanisms of formation of these sulfides is still not well constrained certainly because of possible multiple ways to produce them. We propose to simulate different models of formation in order to check their mineralogical, chemical and textural relevancies. The solubility of sulfur in silicate melts is of primary interest for planetary mantles, particularly for the Earth and Mercury. Indeed, these two planets could have formed, at least partly, from EC materials (e.g. [2, 3, 4]). The sulfur content in silicate melts depends on the melt composition but also on pressure (P), temperature (T) and oxygen fugacity fO2. Unfortunately, there is no model of general validity in a wide range of P-T-fO2-composition which describes precisely the evolution of sulfur content in silicate melts, even if the main trends are now known. The second goal of this study is to constrain the sulfur content in silicate melts under reducing conditions and different temperatures.

  1. Immobilization of mercury in field soil and sediment using carboxymethyl cellulose stabilized iron sulfide nanoparticles

    Science.gov (United States)

    Gong, Yanyan; Liu, Yuanyuan; Xiong, Zhong; Kaback, Dawn; Zhao, Dongye

    2012-07-01

    Mercury (Hg) is one of the most pervasive and bio-accumulative metals in the environment. Yet, effective in situ remediation technologies have been lacking. This study investigated the effectiveness of a class of soil-deliverable FeS nanoparticles for in situ immobilization of Hg in two field-contaminated soils from a New Jersey site and one sediment from an Alabama site. The nanoparticles were prepared using sodium carboxymethyl cellulose (CMC) as a stabilizer. Transmission electron microscopy measurements revealed a particle size of 34.3 ± 8.3 nm (standard deviation), whereas dynamic light scattering gave a hydrodynamic diameter of 222.5 ± 3.2 nm. Batch tests showed that at an FeS-to-Hg molar ratio of 28:1-118:1, the nanoparticles reduced water-leachable Hg by 79%-96% and the TCLP (toxicity characteristic leaching procedure) based leachability by 26%-96%. Column breakthrough tests indicated that the nanoparticles were deliverable in the sediment/soil columns under moderate injection pressure. However, once the external pressure was removed, the delivered nanoparticles remained virtually mobile under typical groundwater flow conditions. When the Hg-contaminated soil and sediment were treated with 52-95 pore volumes of a 500 mg l-1 FeS nanoparticle suspension, water-leachable Hg was reduced by 90%-93% and TCLP-leachable Hg was reduced by 65%-91%. The results warrant further field demonstration of this promising in situ remediation technology.

  2. Mercury

    NARCIS (Netherlands)

    de Vries, Irma

    2017-01-01

    Mercury is a naturally occurring metal that exists in several physical and chemical forms. Inorganic mercury refers to compounds formed after the combining of mercury with elements such as chlorine, sulfur, or oxygen. After combining with carbon by covalent linkage, the compounds formed are called

  3. Mercury contamination extraction

    Science.gov (United States)

    Fuhrmann, Mark [Silver Spring, MD; Heiser, John [Bayport, NY; Kalb, Paul [Wading River, NY

    2009-09-15

    Mercury is removed from contaminated waste by firstly applying a sulfur reagent to the waste. Mercury in the waste is then permitted to migrate to the reagent and is stabilized in a mercury sulfide compound. The stable compound may then be removed from the waste which itself remains in situ following mercury removal therefrom.

  4. Mercury

    Science.gov (United States)

    ... that mercuric chloride and methylmercury are possible human carcinogens. top How does mercury affect children? Very young ... billion parts of drinking water (2 ppb). The Food and Drug Administration (FDA) has set a maximum ...

  5. Importance of Dissolved Neutral Hg-Sulfides, Energy Rich Organic Matter and total Hg Concentrations for Methyl Mercury Production in Sediments

    Science.gov (United States)

    Drott, A.; Skyllberg, U.

    2007-12-01

    brackish waters (palgae and bacteria) in the sediment and a high annual temperature sum, resulted in high methylation rates. In conclusion, concentrations of neutral Hg-sulfides and availability of energy rich organic matter, but also total Hg concentrations in sediments are important factors behind net production and accumulation of MeHg . References: (1) Drott et. al. submitted, (2) Drott, A.; Lambertsson, L.; Björn, E.; Skyllberg, U. Importance of dissolved neutral mercury sulfides for methyl mercury production in contaminated sediments. Environmental Science & Technology 2007, 41, 2270-2276.

  6. Mercury

    CERN Document Server

    Mahoney, T J

    2014-01-01

    This gazetteer and atlas on Mercury lists, defines and illustrates every named (as opposed to merely catalogued) object and term as related to Mercury within a single reference work. It contains a glossary of terminology used, an index of all the headwords in the gazetteer, an atlas comprising maps and images with coordinate grids and labels identifying features listed in the gazetteer, and appendix material on the IAU nomenclature system and the transcription systems used for non-roman alphabets. This book is useful for the general reader, writers and editors dealing with astronomical themes, and those astronomers concerned with any aspect of astronomical nomenclature.

  7. Mercury

    CERN Document Server

    Balogh, André; Steiger, Rudolf

    2008-01-01

    Mercury, the planet closest to the Sun, is different in several respects from the other three terrestrial planets. In appearance, it resembles the heavily cratered surface of the Moon, but its density is high, it has a magnetic field and magnetosphere, but no atmosphere or ionosphere. This book reviews the progress made in Mercury studies since the flybys by Mariner 10 in 1974-75, based on the continued research using the Mariner 10 archive, on observations from Earth, and on increasingly realistic models of its interior evolution.

  8. Metal-Silicate-Sulfide Partitioning of U, Th, and K: Implications for the Budget of Volatile Elements in Mercury

    Science.gov (United States)

    Habermann, M.; Boujibar, A.; Righter, K.; Danielson, L.; Rapp, J.; Righter, M.; Pando, K.; Ross, D. K.; Andreasen, R.

    2016-01-01

    During formation of the solar system, the Sun produced strong solar winds, which stripped away a portion of the volatile elements from the forming planets. Hence, it was expected that planets closest to the sun, such as Mercury, are more depleted in volatile elements in comparison to other terrestrial planets. However, the MESSENGER mission detected higher than expected K/U and K/Th ratios on Mercury's surface, indicating a volatile content between that of Mars and Earth. Our experiments aim to resolve this discrepancy by experimentally determining the partition coefficients (D(sup met/sil)) of K, U, and Th between metal and silicate at varying pressure (1 to 5 GPa), temperature (1500 to 1900 C), oxygen fugacity (IW-2.5 to IW-6.5) and sulfur-content in the metal (0 to 33 wt%). Our data show that U, Th, and K become more siderophile with decreasing fO2 and increasing sulfur-content, with a stronger effect for U and Th in comparison to K. Using these results, the concentrations of U, Th, and K in the bulk planet were calculated for different scenarios, where the planet equilibrated at a fO2 between IW-4 and IW-7, assuming the existence of a FeS layer, between the core and mantle, with variable thickness. These models show that significant amounts of U and Th are partitioned into Mercury's core. The elevated superficial K/U and K/Th values are therefore only a consequence of the sequestration of U and Th into the core, not evidence of the overall volatile content of Mercury.

  9. Effect of sulfide, selenite and mercuric mercury on the growth and methylation capacity of the sulfate reducing bacterium Desulfovibrio desulfuricans

    Energy Technology Data Exchange (ETDEWEB)

    Truong, Hoang-Yen T. [Department of Biology, Laurentian University, Sudbury, Ontario, Canada P3E 2C6 (Canada); Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada P3E 2C6 (Canada); Chen, Yu-Wei [Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada P3E 2C6 (Canada); Belzile, Nelson, E-mail: nbelzile@laurentian.ca [Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada P3E 2C6 (Canada); Cooperative Freshwater Ecology Unit, Laurentian University, Sudbury, Ontario, Canada P3E 2C6 (Canada)

    2013-04-01

    Cultures of the sulfate reducing bacteria Desulfovibrio desulfuricans were grown under anoxic conditions to study the effect of added sulfide, selenite and mercuric ions. A chemical trap consisting in a CuSO{sub 4} solution was used to control the poisoning effect induced by the bacterial production of hydrogen sulfide via the precipitation of CuS. Following the addition of Hg{sup 2+}, the formation of methylmercury (MeHg) was correlated to bacterial proliferation with most of MeHg found in the culture medium. A large fraction (50–80%) of added Hg{sup 2+} to a culture ended up in a solid phase (Hg{sup 0} and likely HgS) limiting its bioavailability to cells with elemental Hg representing ∼ 40% of the solid. Following the addition of selenite, a small fraction was converted into Se(0) inside the cells and, even though the conversion to this selenium species increased with the increase of added selenite, it never reached more than 49% of the added amount. The formation of volatile dimethylselenide is suggested as another detoxification mechanism. In cultures containing both added selenite and mercuric ions, elemental forms of the two compounds were still produced and the increase of selenium in the residual fraction of the culture suggests the formation of mercuric selenite limiting the bioavailability of both elements to cells. - Highlights: ► Detoxification mechanisms of D. desulfuricans were studied in presence of added sulfide, selenite and mercuric ions. ► The poisoning effect of H{sub 2}S added to or generated by cultures of D. desulfuricans can be controlled with a chemical trap. ► The addition of selenite to cultures triggered the formation of elemental Se and other forms of volatile and non-volatile Se. ► The addition of mercuric ions to cultures led to the production of methylmercury, volatile Hg and solid mercuric sulfide. ► With both Se and Hg added to cultures, fractionation of species in solid and liquid phases suggests the formation of HgSe.

  10. Apparatus for control of mercury

    Science.gov (United States)

    Downs, William; Bailey, Ralph T.

    2001-01-01

    A method and apparatus for reducing mercury in industrial gases such as the flue gas produced by the combustion of fossil fuels such as coal adds hydrogen sulfide to the flue gas in or just before a scrubber of the industrial process which contains the wet scrubber. The method and apparatus of the present invention is applicable to installations employing either wet or dry scrubber flue gas desulfurization systems. The present invention uses kraft green liquor as a source for hydrogen sulfide and/or the injection of mineral acids into the green liquor to release vaporous hydrogen sulfide in order to form mercury sulfide solids.

  11. Selenium Sulfide

    Science.gov (United States)

    Selenium sulfide, an anti-infective agent, relieves itching and flaking of the scalp and removes the dry, ... Selenium sulfide comes in a lotion and is usually applied as a shampoo. As a shampoo, selenium ...

  12. Process for removing mercury from aqueous solutions

    Science.gov (United States)

    Googin, John M.; Napier, John M.; Makarewicz, Mark A.; Meredith, Paul F.

    1986-01-01

    A process for removing mercury from water to a level not greater than two parts per billion wherein an anion exchange material that is insoluble in water is contacted first with a sulfide containing compound and second with a compound containing a bivalent metal ion forming an insoluble metal sulfide. To this treated exchange material is contacted water containing mercury. The water containing not more than two parts per billion of mercury is separated from the exchange material.

  13. Electron transfer to sulfides:

    International Nuclear Information System (INIS)

    Meneses, Ana Belen; Antonello, Sabrina; Arevalo, Maria Carmen; Maran, Flavio

    2005-01-01

    The problem of characterizing the steps associated with the dissociative reduction of sulfides has been addressed. The electrochemical reduction of diphenylmethyl para-methoxyphenyl sulfide in N,N-dimethylformamide, on both glassy carbon and mercury electrodes, was chosen as a test system. The electrode process involves the slow heterogeneous outer-sphere electron transfer to the sulfide, the fast cleavage of the C-S bond, the reduction of the ensuing carbon radical, and the self-protonation triggered by the generation of the strong base Ph 2 CH - . The latter reaction is rather slow, in agreement with the large intrinsic barriers characterizing proton transfers between CH-acids and carbon bases. The dissociative reduction was studied in the presence of an exogenous acid. The results, obtained by convolution analysis, point to a stepwise DET mechanism in which the ET step is accompanied by rather large reorganization energy. Similar results were obtained on both electrode materials. Analysis of the heterogeneous electron transfer and associated C-S bond cleavage indicate that the reduction of this and other sulfides lies between the stepwise dissociative electron transfers leading to the formation of stiff π* radical anions and those going through the intermediacy of loose σ* radical anions

  14. Attenuation by methyl mercury and mercuric sulfide of pentobarbital induced hypnotic tolerance in mice through inhibition of ATPase activities and nitric oxide production in cerebral cortex

    Energy Technology Data Exchange (ETDEWEB)

    Chuu, Jiunn-Jye; Huang, Zih-Ning; Yu, Hsun-Hsin; Chang, Liang-Hao [College of Engineering, Southern Taiwan University, Institute of Biotechnology, Tainan (China); Lin-Shiau, Shoei-Yn [College of Medicine, National Taiwan University, Institute of Pharmacology, Taipei (China)

    2008-06-15

    This study is aimed at exploring the possible mechanism of hypnosis-enhancing effect of HgS or cinnabar (a traditional Chinese medicine containing more than 95% HgS) in mice treated with pentobarbital. We also examined whether the effect of HgS is different from that of the well-known methyl mercury (MeHg). After a short period (7 days) of oral administration to mice, a nontoxic dose (0.1 g/kg) of HgS not only significantly enhanced pentobarbital-induced hypnosis but also attenuated tolerance induction; while a higher dose (1 g/kg) of HgS or cinnabar exerted an almost irreversible enhancing effect on pentobarbital-hypnosis similar to that of MeHg (2 mg/kg) tested, which was still effective even after 10 or 35 days cessation of administration. To study comparatively the effects of different mercury forms from oral administration of MeHg and HgS on membrane ATPase activities of experimental mice, analysis of the Hg content in the cerebral cortex revealed that correlated with the decrease of Na{sup +}/K{sup +}-ATPase and Ca{sup 2+}-ATPase activities. Furthermore, NO levels of blood but not that of cerebral cortex were also decreased by mercuric compounds. Although pentobarbital alone enhanced cytochrome p450-2C9 in time dependent manner, all of mercurial compounds tested had no such effect. All of these findings indicated that the mercurial compounds including cinnabar, HgS and MeHg exert a long-lasting enhancing hypnotic activity without affecting pentobarbital metabolism, which provides evidence-based sedative effect of cinnabar used in Chinese traditional medicine for more than 2,000 years. The nontoxic HgS dosing (0.1 g/kg/day) for consecutive 7 days is perhaps useful for delaying or preventing pentobarbital-tolerance. (orig.)

  15. Mercury content in Hot Springs

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, R

    1974-01-01

    A method of determination of mercury in hot spring waters by flameless atomic absorption spectrophotometry is described. Further, the mercury content and the chemical behavior of the elementary mercury in hot springs are described. Sulfide and iodide ions interfered with the determination of mercury by the reduction-vapor phase technique. These interferences could, however, be minimized by the addition of potassium permanganate. Waters collected from 55 hot springs were found to contain up to 26.0 ppb mercury. High concentrations of mercury have been found in waters from Shimoburo Springs, Aomori (10.0 ppb), Osorezan Springs, Aomori (1.3 approximately 18.8 ppb), Gosyogake Springs, Akita (26.0 ppb), Manza Springs, Gunma (0.30 approximately 19.5 ppb) and Kusatu Springs, Gunma (1.70 approximately 4.50 ppb). These hot springs were acid waters containing a relatively high quantity of chloride or sulfate.

  16. STABILIZATION AND TESTING OF MERCURY CONTAINING WASTES: BORDEN SLUDGE

    Science.gov (United States)

    This report details the stability assessment of a mercury containing sulfide treatment sludge. Information contained in this report will consist of background data submitted by the geneerator, landfill data supplied by EPA and characterization and leaching studies conducted by UC...

  17. Histochemical demonstration of two mercury pools in trout tissues: mercury in kidney and liver after mercuric chloride exposure

    DEFF Research Database (Denmark)

    Baatrup, E; Nielsen, M G; Danscher, G

    1987-01-01

    Juvenile rainbow trout (Salmo gairdneri) were exposed to 100 ppb mercury (as HgCl2) in the water for 14 days. Concentrations of mercury in water and fish organs were monitored using radiolabeled mercury. Tissues from kidney and liver were fixed, and sections were developed by autometallography......, a method whereby accumulations of mercury sulfides and/or mercury selenides are silver amplified. In the kidney, mercury was found within lysosomes and extracellularly in the basal lamina of proximal tubules. In the liver, mercury was found within lysosomes of the hepatocytes. Additional groups of mercury......-exposed trout were subjected to selenium (as Na2SeO3), administered intraperitoneally 2 hr before fixation. Following this treatment, additional mercury could be visualized in the kidney circulatory system, including glomeruli, and in the nucleus and endoplasmic reticulum of liver cells. It is suggested...

  18. SULFIDE MINERALS IN SEDIMENTS

    Science.gov (United States)

    The formation processes of metal sulfides in sediments, especially iron sulfides, have been the subjects of intense scientific research because of linkages to the global biogeochemical cycles of iron, sulfur, carbon, and oxygen. Transition metal sulfides (e.g., NiS, CuS, ZnS, Cd...

  19. Mercury and Your Health

    Science.gov (United States)

    ... the Risk of Exposure to Mercury Learn About Mercury What is Mercury What is Metallic mercury? Toxicological Profile ToxFAQs Mercury Resources CDC’s National Biomonitoring Program Factsheet on Mercury ...

  20. Planet Mercury

    Science.gov (United States)

    1974-01-01

    Mariner 10's first image of Mercury acquired on March 24, 1974. During its flight, Mariner 10's trajectory brought it behind the lighted hemisphere of Mercury, where this image was taken, in order to acquire important measurements with other instruments.This picture was acquired from a distance of 3,340,000 miles (5,380,000 km) from the surface of Mercury. The diameter of Mercury (3,031 miles; 4,878 km) is about 1/3 that of Earth.Images of Mercury were acquired in two steps, an inbound leg (images acquired before passing into Mercury's shadow) and an outbound leg (after exiting from Mercury's shadow). More than 2300 useful images of Mercury were taken, both moderate resolution (3-20 km/pixel) color and high resolution (better than 1 km/pixel) black and white coverage.

  1. Mercurial poisoning

    Energy Technology Data Exchange (ETDEWEB)

    Gorton, B

    1924-01-01

    Cats which had been kept in a thermometer factory to catch rats were afflicted with mercury poisoning. So were the rats they were supposed to eat. The symptoms of mercury poisoning were the same in both species. The source of mercury for these animals is a fine film of the metal which coats floors, a result of accidental spills during the manufacturing process.

  2. Purification of hydrogen sulfide

    International Nuclear Information System (INIS)

    Tsao, U.

    1978-01-01

    A process is described for purifying a hydrogen sulfide gas stream containing carbon dioxide, comprising (a) passing the gas stream through a bed of solid hydrated lime to form calcium hydrosulfide and calcium carbonate and (b) regenerating hydrogen sulfide from said calcium hydrosulfide by reacting the calcium hydrosulfide with additional carbon dioxide. The process is especially applicable for use in a heavy water recovery process wherein deuterium is concentrated from a feed water containing carbon dioxide by absorption and stripping using hydrogen sulfide as a circulating medium, and the hydrogen sulfide absorbs a small quantity of carbon dioxide along with deuterium in each circulation

  3. Got Mercury?

    Science.gov (United States)

    Meyers, Valerie E.; McCoy, J. Torin; Garcia, Hector D.; James, John T.

    2009-01-01

    Many of the operational and payload lighting units used in various spacecraft contain elemental mercury. If these devices were damaged on-orbit, elemental mercury could be released into the cabin. Although there are plans to replace operational units with alternate light sources, such as LEDs, that do not contain mercury, mercury-containing lamps efficiently produce high quality illumination and may never be completely replaced on orbit. Therefore, exposure to elemental mercury during spaceflight will remain possible and represents a toxicological hazard. Elemental mercury is a liquid metal that vaporizes slowly at room temperature. However, it may be completely vaporized at the elevated operating temperatures of lamps. Although liquid mercury is not readily absorbed through the skin or digestive tract, mercury vapors are efficiently absorbed through the respiratory tract. Therefore, the amount of mercury in the vapor form must be estimated. For mercury releases from lamps that are not being operated, we utilized a study conducted by the New Jersey Department of Environmental Quality to calculate the amount of mercury vapor expected to form over a 2-week period. For longer missions and for mercury releases occurring when lamps are operating, we conservatively assumed complete volatilization of the available mercury. Because current spacecraft environmental control systems are unable to remove mercury vapors, both short-term and long-term exposures to mercury vapors are possible. Acute exposure to high concentrations of mercury vapors can cause irritation of the respiratory tract and behavioral symptoms, such as irritability and hyperactivity. Chronic exposure can result in damage to the nervous system (tremors, memory loss, insomnia, etc.) and kidneys (proteinurea). Therefore, the JSC Toxicology Group recommends that stringent safety controls and verifications (vibrational testing, etc.) be applied to any hardware that contains elemental mercury that could yield

  4. Accumulation of mercury in selected plant species grown in soils contaminated with different mercury compounds

    International Nuclear Information System (INIS)

    Su, Yi; Han, Fengxiang; Shiyab, Safwan; Chen, Jian; Monts, David L.

    2007-01-01

    of ppm mercury can be accumulated in the roots of Indian mustard plants grown with soil contaminated by mercury sulfide; HgS is assumed to be the most stable and also the predominant mercury form in flood plain soils. We have also started to investigate different mercury uptake mechanisms, such as root uptake of soil contaminant and foliar mercury accumulation from ambient air. We have observed mercury translocation from roots to shoot for Chinese fern and two Indian mustard varieties. (authors)

  5. Histochemical demonstration of two mercury pools in trout tissues: mercury in kidney and liver after mercuric chloride exposure

    International Nuclear Information System (INIS)

    Baatrup, E.; Nielsen, M.G.; Danscher, G.

    1986-01-01

    Juvenile rainbow trout (Salmo gairdneri) were exposed to 100 ppb mercury (as HgCl 2 ) in the water for 14 days. Concentrations of mercury in water and fish organs were monitored using radiolabeled mercury. Tissues from kidney and liver were fixed, and sections were developed by autometallography, a method whereby accumulations of mercury sulfides and/or mercury selenides are silver amplified. In the kidney, mercury was found within lysosomes and extracellularly in the basal lamina of proximal tubules. In the liver, mercury was found within lysosomes of the hepatocytes. Additional groups of mercury-exposed trout were subjected to selenium (as Na 2 SeO 3 ), administered intraperitoneally 2 hr before fixation. Following this treatment, additional mercury could be visualized in the kidney circulatory system, including glomeruli, and in the nucleus and endoplasmic reticulum of liver cells. It is suggested that the mercury visualized prior to selenium treatment represents inorganic mercury, while additional mercury visualized after selenium administration represents an organic form

  6. Mesostructured metal germanium sulfides

    Energy Technology Data Exchange (ETDEWEB)

    MacLachlan, M.J.; Coombs, N.; Bedard, R.L.; White, S.; Thompson, L.K.; Ozin, G.A.

    1999-12-29

    A new class of mesostructured metal germanium sulfide materials has been prepared and characterized. The synthesis, via supramolecular assembly of well-defined germanium sulfide anionic cluster precursors and transition-metal cations in formamide, represents a new strategy for the formation of this class of solids. A variety of techniques were employed to examine the structure and composition of the materials. Structurally, the material is best described as a periodic mesostructured metal sulfide-based coordination framework akin to periodic hexagonal mesoporous silica, MCM-41. At the molecular scale, the materials strongly resemble microstructured metal germanium sulfides, in which the structure of the [Ge{sub 4}S{sub 10}]{sup 4{minus}} cluster building-blocks are intact and linked via {mu}-S-M-S bonds. Evidence for a metal-metal bond in mesostructured Cu/Ge{sub 4}S{sub 10} is also provided.

  7. Mercury removal from natural gas and associated condensates

    Energy Technology Data Exchange (ETDEWEB)

    Hennico, A.; Barthel, Y.; Courty, P. (Institut Francais du Petrole, 31 - Rueil-Malmaison (France). Direction Industrielle)

    1990-01-01

    IFP mercury trapping systems are based on CMG 273, the recently developed Procatalyse product which is the heart of IFP's gas phase and liquid phase mercury removal technology. This material, made of highly macroporous alumina supporting a metal sulfide, presents a very high reactivity towards mecury within a broad range of operating conditions, including those operating in the liquid phase. Characteristics of CMG 273 are presented. (orig.).

  8. Final disposal options for mercury/uranium mixed wastes from the Oak Ridge Reservation

    International Nuclear Information System (INIS)

    Gorin, A.H.; Leckey, J.H.; Nulf, L.E.

    1994-01-01

    Laboratory testing was completed on chemical stabilization and physical encapsulation methods that are applicable (to comply with federal and state regulations) to the final disposal of both hazardous and mixed hazardous elemental mercury waste that is in either of the following categories: (1) waste generated during decontamination and decommissioning (D and D) activities on mercury-contaminated buildings, such as Building 9201-4 at the Oak Ridge Y-12 Plant, or (2) waste stored and regulated under either the Federal Facilities Compliance Agreement or the Federal Facilities Compliance Act. Methods were used that produced copper-mercury, zinc-mercury, and sulfur-mercury materials at room temperature by dry mixing techniques. Toxicity Characteristic Leaching Procedure (TCLP) results for mercury on batches of both the copper-mercury and the sulfur-mercury amalgams consistently produced leachates with less than the 0.2-mg/L Resource Conservation and Recovery Act (RCRA) regulatory limit for mercury. The results clearly showed that the reaction of mercury with sulfur at room temperature produces black mercuric sulfide, a material that is well suited for land disposal. The results also showed that the copper-mercury and zinc-mercury amalgams had major adverse properties that make them undesirable for land disposal. In particular, they reacted readily in air to form oxides and liberate elemental mercury. Another major finding of this study is that sulfur polymer cement is potentially useful as a physical encapsulating agent for mercuric sulfide. This material provides a barrier in addition to the chemical stabilization that further prevents mercury, in the form of mercuric sulfide, from migrating into the environment

  9. Sulfide oxidation in a biofilter

    DEFF Research Database (Denmark)

    Pedersen, Claus Lunde; Dezhao, Liu; Hansen, Michael Jørgen

    Observed hydrogen sulfide uptake rates in a biofilter treating waste air from a pig farm were too high to be explained within conventional limits of sulfide solubility, diffusion in a biofilm and bacterial metabolism. Clone libraries of 16S and 18S rRNA genes from the biofilter found no sulfide...... higher hydrogen sulfide uptake followed by oxidation catalyzed by iron-containing enzymes such as cytochrome c oxidase in a process uncoupled from energy conservation....

  10. Sulfide oxidation in a biofilter

    DEFF Research Database (Denmark)

    Pedersen, Claus Lunde; Liu, Dezhao; Hansen, Michael Jørgen

    2012-01-01

    Observed hydrogen sulfide uptake rates in a biofilter treating waste air from a pig farm were too high to be explained within conventional limits of sulfide solubility, diffusion in a biofilm and bacterial metabolism. Clone libraries of 16S and 18S rRNA genes from the biofilter found no sulfide...... higher hydrogen sulfide uptake followed by oxidation catalyzed by iron-containing enzymes such as cytochrome c oxidase in a process uncoupled from energy conservation....

  11. Titanocene sulfide chemistry

    Czech Academy of Sciences Publication Activity Database

    Horáček, Michal

    2016-01-01

    Roč. 314, MAY 2016 (2016), s. 83-102 ISSN 0010-8545 R&D Projects: GA ČR(CZ) GAP207/12/2368 Institutional support: RVO:61388955 Keywords : titanocene sulfide chemistry * photolysis * titanocene hydrosulfides Ti-(SH)n Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 13.324, year: 2016

  12. Gravity field and internal structure of Mercury from MESSENGER.

    Science.gov (United States)

    Smith, David E; Zuber, Maria T; Phillips, Roger J; Solomon, Sean C; Hauck, Steven A; Lemoine, Frank G; Mazarico, Erwan; Neumann, Gregory A; Peale, Stanton J; Margot, Jean-Luc; Johnson, Catherine L; Torrence, Mark H; Perry, Mark E; Rowlands, David D; Goossens, Sander; Head, James W; Taylor, Anthony H

    2012-04-13

    Radio tracking of the MESSENGER spacecraft has provided a model of Mercury's gravity field. In the northern hemisphere, several large gravity anomalies, including candidate mass concentrations (mascons), exceed 100 milli-Galileos (mgal). Mercury's northern hemisphere crust is thicker at low latitudes and thinner in the polar region and shows evidence for thinning beneath some impact basins. The low-degree gravity field, combined with planetary spin parameters, yields the moment of inertia C/MR(2) = 0.353 ± 0.017, where M and R are Mercury's mass and radius, and a ratio of the moment of inertia of Mercury's solid outer shell to that of the planet of C(m)/C = 0.452 ± 0.035. A model for Mercury's radial density distribution consistent with these results includes a solid silicate crust and mantle overlying a solid iron-sulfide layer and an iron-rich liquid outer core and perhaps a solid inner core.

  13. Mercury speciation during in situ thermal desorption in soil

    Energy Technology Data Exchange (ETDEWEB)

    Park, Chang Min, E-mail: cmpark80@gmail.com; Katz, Lynn E.; Liljestrand, Howard M.

    2015-12-30

    Highlights: • Impact of soil conditions on distribution and phase transitions of Hg was identified. • Metallic Hg was slowly transformed to Hg{sup 0} gas until the temperature reached 358.15 K. • Phase change of HgCl{sub 2(s)} completely occurred without decomposition at 335.15 K. • HgS remained solid in dry soil sharply decreased in the narrow temperature range. • Hg gas can be easily captured with higher vapor pressures of soil compositions. - Abstract: Metallic mercury (Hg{sup 0}) and its compounds are highly mobile and toxic environmental pollutants at trace level. In situ thermal desorption (ISTD) is one of the soil remediation processes applying heat and vacuum simultaneously. Knowledge of thermodynamic mercury speciation is imperative to understand the fate and transport of mercury during thermal remediation and operate the treatment processes in a cost-effective manner. Hence, speciation model for inorganic mercury was developed over a range of environmental conditions to identify distribution of dissolved mercury species and potential transformations of mercury at near source environment. Simulation of phase transitions for metallic mercury, mercury(II) chloride and mercury sulfide with temperature increase showed that complete vaporization of metallic mercury and mercury(II) chloride were achieved below the boiling point of water. The effect of soil compositions on mercury removal was also evaluated to better understand thermal remediation process. Higher vapor pressures expected both from soil pore water and inorganic carbonate minerals in soil as well as creation of permeability were significant for complete vaporization and removal of mercury.

  14. Mercury speciation during in situ thermal desorption in soil

    International Nuclear Information System (INIS)

    Park, Chang Min; Katz, Lynn E.; Liljestrand, Howard M.

    2015-01-01

    Highlights: • Impact of soil conditions on distribution and phase transitions of Hg was identified. • Metallic Hg was slowly transformed to Hg"0 gas until the temperature reached 358.15 K. • Phase change of HgCl_2_(_s_) completely occurred without decomposition at 335.15 K. • HgS remained solid in dry soil sharply decreased in the narrow temperature range. • Hg gas can be easily captured with higher vapor pressures of soil compositions. - Abstract: Metallic mercury (Hg"0) and its compounds are highly mobile and toxic environmental pollutants at trace level. In situ thermal desorption (ISTD) is one of the soil remediation processes applying heat and vacuum simultaneously. Knowledge of thermodynamic mercury speciation is imperative to understand the fate and transport of mercury during thermal remediation and operate the treatment processes in a cost-effective manner. Hence, speciation model for inorganic mercury was developed over a range of environmental conditions to identify distribution of dissolved mercury species and potential transformations of mercury at near source environment. Simulation of phase transitions for metallic mercury, mercury(II) chloride and mercury sulfide with temperature increase showed that complete vaporization of metallic mercury and mercury(II) chloride were achieved below the boiling point of water. The effect of soil compositions on mercury removal was also evaluated to better understand thermal remediation process. Higher vapor pressures expected both from soil pore water and inorganic carbonate minerals in soil as well as creation of permeability were significant for complete vaporization and removal of mercury.

  15. Mercury's Messenger

    Science.gov (United States)

    Chapman, Clark R.

    2004-01-01

    Forty years after Mariner 2, planetary exploration has still only just begun, and many more missions are on drawing boards, nearing the launch pad, or even en route across interplanetary space to their targets. One of the most challenging missions that will be conducted this decade is sending the MESSENGER spacecraft to orbit the planet Mercury.…

  16. Mercury Report-Children's exposure to elemental mercury

    Science.gov (United States)

    ... gov . Mercury Background Mercury Report Additional Resources Mercury Report - Children's Exposure to Elemental Mercury Recommend on Facebook ... I limit exposure to mercury? Why was the report written? Children attending a daycare in New Jersey ...

  17. Regenerative process for removal of mercury and other heavy metals from gases containing H.sub.2 and/or CO

    Science.gov (United States)

    Jadhav, Raja A [Naperville, IL

    2009-07-07

    A method for removal of mercury from a gaseous stream containing the mercury, hydrogen and/or CO, and hydrogen sulfide and/or carbonyl sulfide in which a dispersed Cu-containing sorbent is contacted with the gaseous stream at a temperature in the range of about 25.degree. C. to about 300.degree. C. until the sorbent is spent. The spent sorbent is contacted with a desorbing gaseous stream at a temperature equal to or higher than the temperature at which the mercury adsorption is carried out, producing a regenerated sorbent and an exhaust gas comprising released mercury. The released mercury in the exhaust gas is captured using a high-capacity sorbent, such as sulfur-impregnated activated carbon, at a temperature less than about 100.degree. C. The regenerated sorbent may then be used to capture additional mercury from the mercury-containing gaseous stream.

  18. Cytochemical demonstration of mercury deposits in trout liver and kidney following methyl mercury intoxication: differentiation of two mercury pools by selenium

    DEFF Research Database (Denmark)

    Baatrup, E; Danscher, G

    1988-01-01

    and the selected organs were determined by measuring the uptake of 203Hg-labeled MeHg. Spleen, liver, and kidney had the highest concentrations after both experimental periods, while the largest relative increases were found in brain, muscle, and kidney. The subcellular distribution of mercury accumulations...... was demonstrated cytochemically in liver and kidney using the silver enhancement method by which accumulations of mercury-sulfides and/or mercury-selenides are made visible for light and electron microscopy. When sections prepared from the liver and kidney from fish, injected with selenium 2 hr prior to being...... pronounced in the kidney. The HgSe pool, supposed to represent methyl mercury, was shown by the presence of silver deposits at new locations as well as by an increase in the amount of deposits within lysosomes. The new locations included (1) secretory-like vesicles and the bile canaliculi of the liver...

  19. STABILIZATION OF A MIXED WASTE SLUDGE SURROGATE CONTAINING MORE THAN 260 PPM MERCURY

    International Nuclear Information System (INIS)

    Smith, W. J.; Feizollahi, F.; Brimley, R.

    2002-01-01

    In an earlier demonstration of an innovative mercury stabilization technology for the Department of Energy, ATG's full-scale process stabilized mercury in soils that initially contained more than 260 ppm of mercury of unknown speciation. The treated waste satisfied the leaching standards for mercury that qualify wastes containing less than 260 ppm for land disposal. This paper describes the extension of that work to demonstrate a full-scale process for the stabilization of a representative sludge that contained more than 260 ppm of Hg of several mercury species. RCRA (Resource Conservation and Recovery Act) regulations now require the recovery of mercury from any waste containing more than 260 ppm of mercury, usually with thermal retorts. The results of this work with a surrogate sludge, and of the previous work with an actual soil, support a proposal now before the U.S. EPA (Environmental Protection Agency) to allow such wastes to be stabilized without retorting. The full-scale demonstration with a sulfide reagent reduced the mercury concentrations in extracts of treated sludge below the relevant leaching standard, a Universal Treatment Standard (UTS) limit of 0.025 mg mercury per liter of leachate generated by the Toxicity Characteristic Leaching Procedure (TCLP). The sulfide formulation reduced the concentration to about onehalf the UTS limit

  20. Mercury removal in utility wet scrubber using a chelating agent

    Science.gov (United States)

    Amrhein, Gerald T.

    2001-01-01

    A method for capturing and reducing the mercury content of an industrial flue gas such as that produced in the combustion of a fossil fuel or solid waste adds a chelating agent, such as ethylenediaminetetraacetic acid (EDTA) or other similar compounds like HEDTA, DTPA and/or NTA, to the flue gas being scrubbed in a wet scrubber used in the industrial process. The chelating agent prevents the reduction of oxidized mercury to elemental mercury, thereby increasing the mercury removal efficiency of the wet scrubber. Exemplary tests on inlet and outlet mercury concentration in an industrial flue gas were performed without and with EDTA addition. Without EDTA, mercury removal totaled 42%. With EDTA, mercury removal increased to 71%. The invention may be readily adapted to known wet scrubber systems and it specifically provides for the removal of unwanted mercury both by supplying S.sup.2- ions to convert Hg.sup.2+ ions into mercuric sulfide (HgS) and by supplying a chelating agent to sequester other ions, including but not limited to Fe.sup.2+ ions, which could otherwise induce the unwanted reduction of Hg.sup.2+ to the form, Hg.sup.0.

  1. Bioavailability and Methylation Potential of Mercury Sulfides in Sediments

    Science.gov (United States)

    2014-08-01

    well-characterized for the fungus Neurospora crassa 72 , and likely occurs within most microorganisms 73 . Another possibility introduced by Larose...of molecular biology (e.g. genomics, proteomics , metabolomics) could provide assistance to this problem 67 . For example, scientists are now... proteomics tools to characterize the proteins involved in metabolic pathways and to determine the proteome of microorganisms exposed to contaminants

  2. Decommissioning and safety issues of liquid-mercury waste generated from high power spallation sources with particle accelerators

    CERN Document Server

    Chiriki, S; Odoj, R; Moormann, R; Hinssen, H. K; Bukaemskiy, A

    2009-01-01

    Large spallation sources are intended to be constructed in Europe (EURISOL nuclear physics facility and ESS-European Spallation Source). These facilities accumulate more than 20 metric tons of irradiated mercury in the target, which has to be treated as highly radioactive and chemo-toxic waste. Because solids are the only appropriate (immobile) form for this radiotoxic and toxic type of waste solidification is required for irradiated mercury. Our irradiation experimental studies on mercury waste revealed that mercury sulfide is a reasonable solid for disposal and shows larger stability in assumed accidents with water ingress in a repository compared to amalgams. For preparation of mercury sulfide a wet process is more suitable than a dry one. It is easier to perform under hot cell conditions and allows complete Hg-conversion. Embedding HgS in a cementitious matrix increases its stability.

  3. Mining, metallurgy and the historical origin of mercury pollution in lakes and watercourses in Central Sweden.

    Science.gov (United States)

    Bindler, Richard; Yu, Ruilian; Hansson, Sophia; Classen, Neele; Karlsson, Jon

    2012-08-07

    In Central Sweden an estimated 80% of the lakes contain fish exceeding health guidelines for mercury. This area overlaps extensively with the Bergslagen ore region, where intensive mining of iron ores and massive sulfide ores occurred over the past millennium. Although only a few mines still operate today, thousands of mineral occurrences and mining sites are documented in the region. Here, we present data on long-term mercury pollution in 16 sediment records from 15 lakes, which indicate that direct release of mercury to lakes and watercourses was already significant prior to industrialization (mines. Although the timing and magnitude of the historical increases in mercury are heterogeneous among lakes, the data provide unambiguous evidence for an incidental release of mercury along with other mining metals to lakes and watercourses, which suggests that the present-day problem of elevated mercury concentrations in the Bergslagen region can trace its roots back to historical mining.

  4. Measurements of Mercury Released From Solidified/Stabilized Waste Forms-FY2002

    International Nuclear Information System (INIS)

    Mattus, C.H.

    2003-01-01

    This report covers work performed during FY 2002 in support of treatment demonstrations conducted for the U.S. Department of Energy (DOE) Mixed Waste Focus Area (MWFA) Mercury Working Group. To comply with the requirements of the Resource Conservation and Recovery Act, as implemented by the U.S. Environmental Protection Agency (EPA), DOE must use one of the following procedures for mixed low-level radioactive wastes containing mercury at levels above 260 ppm: a retorting/roasting treatment or (if the wastes also contain organics) an incineration treatment. The recovered radioactively contaminated mercury must then be treated by an amalgamation process prior to disposal. The DOE MWFA Mercury Working Group is working with EPA to determine whether some alternative processes could be used to treat these types of waste directly, thereby avoiding a costly recovery step for DOE. In previous years, demonstrations were performed in which commercial vendors applied their technologies for the treatment of radiologically contaminated elemental mercury as well as radiologically contaminated and mercury-contaminated waste soils from Brookhaven National Laboratory. The test results for mercury release in the headspace were reported in two reports, ''Measurements of Mercury Released from Amalgams and Sulfide Compounds'' (ORNL/TM-13728) and ''Measurements of Mercury Released from Solidified/Stabilized Waste Forms'' (ORNL/TM-2001/17). The current work did not use a real waste; a surrogate sludge had been prepared and used in the testing in an effort to understand the consequences of mercury speciation on mercury release

  5. Sulfide Mineral Surfaces

    International Nuclear Information System (INIS)

    Rosso, Kevin M.; Vaughan, David J.

    2006-01-01

    The past twenty years or so have seen dramatic development of the experimental and theoretical tools available to study the surfaces of solids at the molecular (?atomic resolution?) scale. On the experimental side, two areas of development well illustrate these advances. The first concerns the high intensity photon sources associated with synchrotron radiation; these have both greatly improved the surface sensitivity and spatial resolution of already established surface spectroscopic and diffraction methods, and enabled the development of new methods for studying surfaces. The second centers on the scanning probe microscopy (SPM) techniques initially developed in the 1980's with the first scanning tunneling microscope (STM) and atomic force microscope (AFM) experiments. The direct 'observation' of individual atoms at surfaces made possible with these methods has truly revolutionized surface science. On the theoretical side, the availability of high performance computers coupled with advances in computational modeling has provided powerful new tools to complement the advances in experiment. Particularly important have been the quantum mechanics based computational approaches such as density functional theory (DFT), which can now be easily used to calculate the equilibrium crystal structures of solids and surfaces from first principles, and to provide insights into their electronic structure. In this chapter, we review current knowledge of sulfide mineral surfaces, beginning with an overview of the principles relevant to the study of the surfaces of all crystalline solids. This includes the thermodynamics of surfaces, the atomic structure of surfaces (surface crystallography and structural stability, adjustments of atoms at the surface through relaxation or reconstruction, surface defects) and the electronic structure of surfaces. We then discuss examples where specific crystal surfaces have been studied, with the main sulfide minerals organized by structure type

  6. Sulfide Mineral Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Rosso, Kevin M.; Vaughan, David J.

    2006-08-01

    The past twenty years or so have seen dramatic development of the experimental and theoretical tools available to study the surfaces of solids at the molecular (?atomic resolution?) scale. On the experimental side, two areas of development well illustrate these advances. The first concerns the high intensity photon sources associated with synchrotron radiation; these have both greatly improved the surface sensitivity and spatial resolution of already established surface spectroscopic and diffraction methods, and enabled the development of new methods for studying surfaces. The second centers on the scanning probe microscopy (SPM) techniques initially developed in the 1980's with the first scanning tunneling microscope (STM) and atomic force microscope (AFM) experiments. The direct 'observation' of individual atoms at surfaces made possible with these methods has truly revolutionized surface science. On the theoretical side, the availability of high performance computers coupled with advances in computational modeling has provided powerful new tools to complement the advances in experiment. Particularly important have been the quantum mechanics based computational approaches such as density functional theory (DFT), which can now be easily used to calculate the equilibrium crystal structures of solids and surfaces from first principles, and to provide insights into their electronic structure. In this chapter, we review current knowledge of sulfide mineral surfaces, beginning with an overview of the principles relevant to the study of the surfaces of all crystalline solids. This includes the thermodynamics of surfaces, the atomic structure of surfaces (surface crystallography and structural stability, adjustments of atoms at the surface through relaxation or reconstruction, surface defects) and the electronic structure of surfaces. We then discuss examples where specific crystal surfaces have been studied, with the main sulfide minerals organized by

  7. Sulfur polymer cement stabilization of elemental mercury mixed waste

    International Nuclear Information System (INIS)

    Melamed, D.; Fuhrmann, M.; Kalb, P.; Patel, B.

    1998-04-01

    Elemental mercury, contaminated with radionuclides, is a problem throughout the Department of Energy (DOE) complex. This report describes the development and testing of a process to immobilize elemental mercury, contaminated with radionuclides, in a form that is non-dispersible, will meet EPA leaching criteria, and has low mercury vapor pressure. In this stabilization and solidification process (patent pending) elemental mercury is mixed with an excess of powdered sulfur polymer cement (SPC) and additives in a vessel and heated to ∼35 C, for several hours, until all of the mercury is converted into mercuric sulfide (HgS). Additional SPC is then added and the mixture raised to 135 C, resulting in a homogeneous molten liquid which is poured into a suitable mold where is cools and solidifies. The final stabilized and solidified waste forms were characterized by powder X-ray diffraction, as well as tested for leaching behavior and mercury vapor pressure. During this study the authors have processed the entire inventory of mixed mercury waste stored at Brookhaven National Laboratory (BNL)

  8. Mechanochemical reduction of copper sulfide

    DEFF Research Database (Denmark)

    Balaz, P.; Takacs, L.; Jiang, Jianzhong

    2002-01-01

    The mechanochemical reduction of copper sulfide with iron was induced in a Fritsch P-6 planetary mill, using WC vial filled with argon and WC balls. Samples milled for specific intervals were analyzed by XRD and Mossbauer spectroscopy. Most of the reaction takes place during the first 10 min...... of milling and only FeS and Cu are found after 60 min. The main chemical process is accompanied by phase transformations of the sulfide phases as a result of milling. Djurleite partially transformed to chalcocite and a tetragonal copper sulfide phase before reduction. The cubic modification of FeS was formed...... first, transforming to hexagonal during the later stages of the process. The formation of off-stoichiometric phases and the release of some elemental sulfur by copper sulfide are also probable....

  9. Iodide-photocatalyzed reduction of carbon dioxide to formic acid with thiols and hydrogen sulfide

    OpenAIRE

    Berton, Mateo Otao; Mello, Rossella C. C.; González Núñez, María Elena

    2016-01-01

    The photolysis of iodide anions promotes the reaction of carbon dioxide with hydrogen sulfide or thiols to quantitatively yield formic acid and sulfur or disulfides. The reaction proceeds in acetonitrile and aqueous solutions, at atmospheric pressure and room temperature by irradiation using a low-pressure mercury lamp. This transition-metal-free photocatalytic process for CO2 capture coupled with H2S removal may have been relevant as a prebiotic carbon dioxide fixation.

  10. LIGNOCELLULOSE NANOCOMPOSITE CONTAINING COPPER SULFIDE

    OpenAIRE

    Sanchi Nenkova; Peter Velev; Mirela Dragnevska; Diyana Nikolova; Kiril Dimitrov

    2011-01-01

    Copper sulfide-containing lignocellulose nanocomposites with improved electroconductivity were obtained. Two methods for preparing the copper sulfide lignocellulose nanocomposites were developed. An optimization of the parameters for obtaining of the nanocomposites with respect to obtaining improved electroconductivity, economy, and lower quantities and concentration of copper and sulfur ions in waste waters was conducted. The mechanisms and schemes of delaying and subsequent connection of co...

  11. Characterization of mercury forms in contaminated floodplain soils

    International Nuclear Information System (INIS)

    Barnett, M.O.; Turner, R.R.; Henson, T.J.; Harris, L.A.; Melton, R.E.; Stevenson, R.J.

    1994-01-01

    The chemical form or speciation of Hg in the floodplain soils of the East Fork Poplar Creek in Oak Ridge TN, a site contaminated from past industrial activity, was investigated. Hg speciation in the soils is an important factor in controlling the fate and effect of mercury at the site and in assessing human health and ecological risk. Application of 3 different sequential extraction speciation schemes indicated the Hg at the site was predominantly relatively insoluble mercuric sulfide or metallic Hg, though the relative proportions of each did not agree well between procedures. Application of x-ray and electron beam studies to site soils confirmed the presence of metacinnabar, a form of mercuric sulfide, the first known evidence of authigenic mercuric sulfide formation in soils

  12. Determination of mercury in ppb level by activation analysis and chemical separation

    International Nuclear Information System (INIS)

    Requejo, C.S.

    1983-02-01

    A method for determining mercury in steel samples was developed. Activation analysis using thermal neutrons, followed by radiochemical separations to eliminate 75 Se interferences, were applied. Sixty hours after the end of the irradiation, the samples were processed and distillation of mercury and selenium bromides were carried out. Selenium was separated as an element and mercury sulfide was precipitaded. The chemical separation procedure was tested by using a tracer technique; the recovery yield was 99,2% + - 2,7%. (C.L.B.) [pt

  13. Mercury speciation in environmental solid samples using thermal release technique with atomic absorption detection

    Energy Technology Data Exchange (ETDEWEB)

    Shuvaeva, Olga V. [Institute of Inorganic Chemistry, Academician Lavrent' ev Prospect 3, 630090 Novosbirsk (Russian Federation)], E-mail: olga@che.nsk.su; Gustaytis, Maria A.; Anoshin, Gennadii N. [Institute of Geology and Mineralogy, Siberian Branch of Russian Academy of Sciences, Koptyug Prospect 3, 630090 Novosibirsk (Russian Federation)

    2008-07-28

    A sensitive and very simple method for determination of mercury species in solid samples has been developed involving thermal release analysis in combination with atomic absorption (AAS) detection. The method allows determination of mercury(II) chloride, methylmercury and mercury sulfide at the level of 0.70, 0.35 and 0.20 ng with a reproducibility of the results of 14, 25 and 18%, respectively. The accuracy of the developed assay has been estimated using certified reference materials and by comparison of the results with those of an independent method. The method has been applied for Hg species determination in original samples of lake sediments and plankton.

  14. Global Trends in Mercury Management

    Science.gov (United States)

    Choi, Kyunghee

    2012-01-01

    The United Nations Environmental Program Governing Council has regulated mercury as a global pollutant since 2001 and has been preparing the mercury convention, which will have a strongly binding force through Global Mercury Assessment, Global Mercury Partnership Activities, and establishment of the Open-Ended Working Group on Mercury. The European Union maintains an inclusive strategy on risks and contamination of mercury, and has executed the Mercury Export Ban Act since December in 2010. The US Environmental Protection Agency established the Mercury Action Plan (1998) and the Mercury Roadmap (2006) and has proposed systematic mercury management methods to reduce the health risks posed by mercury exposure. Japan, which experienced Minamata disease, aims vigorously at perfection in mercury management in several ways. In Korea, the Ministry of Environment established the Comprehensive Plan and Countermeasures for Mercury Management to prepare for the mercury convention and to reduce risks of mercury to protect public health. PMID:23230466

  15. Basic Information about Mercury

    Science.gov (United States)

    ... or metallic mercury is a shiny, silver-white metal and is liquid at room temperature. It is ... releases can happen naturally. Both volcanoes and forest fires send mercury into the atmosphere. Human activities, however, ...

  16. Minamata Convention on Mercury

    Science.gov (United States)

    On November 6, 2013 the United States signed the Minamata Convention on Mercury, a new multilateral environmental agreement that addresses specific human activities which are contributing to widespread mercury pollution

  17. Speciation of mercury in soils and sediments by thermal evaporation and cold vapor atomic absorption

    International Nuclear Information System (INIS)

    Bombach, G.; Bombach, K.; Klemm, W.

    1994-01-01

    Evaporation studies of mercury in several chemical compounds, soils, and sediments with a high content of organic matter indicate that a quantitative release is possible at temperatures as low as 400 C. The desorption behaviour from a gold column is not influenced. Only from samples with a thermal prehistory, such as brown coal ash, did mercury evaporate at higher temperatures. Qualitative conclusions can be derived about the content of metallic mercury as well as mercury associated with organic matter or sulfide. A comparison of the analytical results obtained by using the evaporation technique or by dissolving using a mixture of conc. HCl and HNO 3 shows good agreement; the advantages of the evaporation technique are obvious at very low mercury concentrations. (orig.)

  18. Mercury in Your Environment

    Science.gov (United States)

    Basic information about mercury, how it gets in the air, how people are exposed to it and health effects associated with exposure; what EPA and other organizations are doing to limit exposures; what citizens should know to minimize exposures and to reduce mercury in the environment; and information about products that contain mercury.

  19. Intoxication with metallic mercury

    International Nuclear Information System (INIS)

    Fichte, B.; Assmann, H.; Ritzau, F.

    1984-01-01

    Intoxications by metallic mercury are extremely rare. Report of a patient, who tried to commit suicide by subcutaneous injection of 500 g of metallic mercury. He died 16 months later in the course of the intoxication. A short review is given of effects and reactions of metallic mercury in the human organism. (orig.) [de

  20. Intoxication with metallic mercury

    Energy Technology Data Exchange (ETDEWEB)

    Fichte, B.; Ritzau, F.; Assmann, H.

    1984-02-01

    Intoxications by metallic mercury are extremely rare. Report is given of a patient who tried to commit suicide by subcutaneous injection of 500 g of metallic mercury. He died 16 months later in the course of the intoxication. A short review is given of effects and reactions of metallic mercury in the human organism.

  1. Intoxication with metallic mercury

    Energy Technology Data Exchange (ETDEWEB)

    Fichte, B.; Assmann, H.; Ritzau, F.

    1984-02-01

    Intoxications by metallic mercury are extremely rare. Report is given of a patient, who tried to commit suicide by subcutaneous injection of 500 g of metallic mercury. He died 16 months later in the course of the intoxication. A short review is given of effects and reactions of metallic mercury in the human organism.

  2. A Reaction Involving Oxygen and Metal Sulfides.

    Science.gov (United States)

    Hill, William D. Jr.

    1986-01-01

    Describes a procedure for oxygen generation by thermal decomposition of potassium chlorate in presence of manganese dioxide, reacted with various sulfides. Provides a table of sample product yields for various sulfides. (JM)

  3. Efficiency of solvent extraction methods for the determination of methyl mercury in forest soils

    Energy Technology Data Exchange (ETDEWEB)

    Qian, J. [Department of Forest Ecology, Swedish University of Agricultural Sciences, Umeaa (Sweden); Dept. of Analytical Chemistry, Umeaa Univ. (Sweden); Skyllberg, U. [Department of Forest Ecology, Swedish University of Agricultural Sciences, Umeaa (Sweden); Tu, Q.; Frech, W. [Dept. of Analytical Chemistry, Umeaa Univ. (Sweden); Bleam, W.F. [Dept. of Soil Science, University of Wisconsin, Madison, WI (United States)

    2000-07-01

    Methyl mercury was determined by gas chromatography, microwave induced plasma, atomic emission spectrometry (GC-MIP-AES) using two different methods. One was based on extraction of mercury species into toluene, pre-concentration by evaporation and butylation of methyl mercury with a Grignard reagent followed by determination. With the other, methyl mercury was extracted into dichloromethane and back extracted into water followed by in situ ethylation, collection of ethylated mercury species on Tenax and determination. The accuracy of the entire procedure based on butylation was validated for the individual steps involved in the method. Methyl mercury added to various types of soil samples showed an overall average recovery of 87.5%. Reduced recovery was only caused by losses of methyl mercury during extraction into toluene and during pre-concentration by evaporation. The extraction of methyl mercury added to the soil was therefore quantitative. Since it is not possible to directly determine the extraction efficiency of incipient methyl mercury, the extraction efficiency of total mercury with an acidified solution containing CuSO{sub 4} and KBr was compared with high-pressure microwave acid digestion. The solvent extraction efficiency was 93%. For the IAEA 356 sediment certified reference material, mercury was less efficiently extracted and determined methyl mercury concentrations were below the certified value. Incomplete extraction could be explained by the presence of a large part of inorganic sulfides, as determined by x-ray absorption near-edge structure spectroscopy (XANES). Analyses of sediment reference material CRM 580 gave results in agreement with the certified value. The butylation method gave a detection limit for methyl mercury of 0.1 ng g{sup -1}, calculated as three times the standard deviation for repeated analysis of soil samples. Lower values were obtained with the ethylation method. The precision, expressed as RSD for concentrations 20 times

  4. Mercury from combustion sources: a review of the chemical species emitted and their transport in the atmosphere

    International Nuclear Information System (INIS)

    Carpi, A.

    1997-01-01

    Different species of mercury have different physical/chemical properties and thus behave quite differentially in air pollution control equipment and in the atmosphere. In general, emission of mercury from coal combustion sources are approximately 20-50% elemental mercury (Hg 0 ) and 50-80% divalent mercury (Hg(II)), which may be predominantly HgCl 2 . Emissions of mercury from waste incinerators are approximately 10-20% Hg 0 and 75-85% Hg(II). The partitioning of mercury in flue gas between the elemental and divalent forms may be dependent on the concentration of particulate carbon, HCl and other pollutants in the stack emissions. The emission of mercury from combustion facilities depends on the species in the exhaust stream and the type of air pollution control equipment used at the source. Air pollution control equipment for mercury removal at combustion facilities includes activated carbon injection, sodium sulfide injection and wet lime/limestone flue gas desulfurization. White Hg(II) is water-soluble and may be removed form the atmosphere by wet and dry deposition close to the combustion sources, the combination of a high vapor pressure and low water-solubility facilitate the long-range transport of Hg 0 in the atmosphere. Background mercury in the atmosphere is predominantly Hg 0 . Elemental mercury is eventually removed from the atmosphere by dry deposition onto surfaces and by wet deposition after oxidation to water-soluble, divalent mercury. 62 refs., 2 figs., 1 tab

  5. Sulfide-conducting solid electrolytes

    International Nuclear Information System (INIS)

    Kalinina, L.A.; Shirokova, G.I.; Murin, I.V.; Ushakova, Yu.N.; Fominykh, E.G.; Lyalina, M.Yu.

    2000-01-01

    Feasibility of sulfide transfer in phases on the basis of BaZrS 3 and MLn 2 S 4 ( M = Ca, Ba; Ln = La, Y, Tm, Nd, Sm, Pr) is considered. Solid solution regions on the basis of ternary compounds are determined. Systematic study of the phases is carried out making use of the methods of conductometry, emf in chemical concentration chains without/with transfer, potentiostatic chronoamperometry. Possible mechanism of defect formation during successive alloying of ternary sulfides by binary ones in suggested [ru

  6. Nanostructured metal sulfides for energy storage

    Science.gov (United States)

    Rui, Xianhong; Tan, Huiteng; Yan, Qingyu

    2014-08-01

    Advanced electrodes with a high energy density at high power are urgently needed for high-performance energy storage devices, including lithium-ion batteries (LIBs) and supercapacitors (SCs), to fulfil the requirements of future electrochemical power sources for applications such as in hybrid electric/plug-in-hybrid (HEV/PHEV) vehicles. Metal sulfides with unique physical and chemical properties, as well as high specific capacity/capacitance, which are typically multiple times higher than that of the carbon/graphite-based materials, are currently studied as promising electrode materials. However, the implementation of these sulfide electrodes in practical applications is hindered by their inferior rate performance and cycling stability. Nanostructures offering the advantages of high surface-to-volume ratios, favourable transport properties, and high freedom for the volume change upon ion insertion/extraction and other reactions, present an opportunity to build next-generation LIBs and SCs. Thus, the development of novel concepts in material research to achieve new nanostructures paves the way for improved electrochemical performance. Herein, we summarize recent advances in nanostructured metal sulfides, such as iron sulfides, copper sulfides, cobalt sulfides, nickel sulfides, manganese sulfides, molybdenum sulfides, tin sulfides, with zero-, one-, two-, and three-dimensional morphologies for LIB and SC applications. In addition, the recently emerged concept of incorporating conductive matrices, especially graphene, with metal sulfide nanomaterials will also be highlighted. Finally, some remarks are made on the challenges and perspectives for the future development of metal sulfide-based LIB and SC devices.

  7. 30 CFR 250.504 - Hydrogen sulfide.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Hydrogen sulfide. 250.504 Section 250.504... OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Well-Completion Operations § 250.504 Hydrogen sulfide. When a well-completion operation is conducted in zones known to contain hydrogen sulfide (H2S) or in...

  8. 30 CFR 250.808 - Hydrogen sulfide.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Hydrogen sulfide. 250.808 Section 250.808... OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Production Safety Systems § 250.808 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of H2S...

  9. 30 CFR 250.604 - Hydrogen sulfide.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Hydrogen sulfide. 250.604 Section 250.604... OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Well-Workover Operations § 250.604 Hydrogen sulfide. When a well-workover operation is conducted in zones known to contain hydrogen sulfide (H2S) or in...

  10. Mercury balance analysis

    International Nuclear Information System (INIS)

    Maag, J.; Lassen, C.; Hansen, E.

    1996-01-01

    A detailed assessment of the consumption of mercury, divided into use areas, was carried out. Disposal and emissions to the environment were also qualified. The assessment is mainly based on data from 1992 - 1993. The most important source of emission of mercury to air is solid waste incineration which is assessed in particular to be due to the supply of mercury in batteries (most likely mercury oxide batteries from photo equipment) and to dental fillings. The second most important source of mercury emission to air is coal-fired power plants which are estimated to account for 200-500 kg of mercury emission p.a. Other mercury emissions are mainly related to waste treatment and disposal. The consumption of mercury is generally decreasing. During the period from 1982/83 - 1992-93, the total consumption of mercury in Denmark was about halved. This development is related to the fact that consumption with regard to several important use areas (batteries, dental fillings, thermometers etc.) has been significantly reduced, while for other purposes the use of mercury has completely, or almost disappeared, i.e. (fungicides for seed, tubes etc.). (EG)

  11. STUDY OF HYDROGEN SULFIDE REMOVAL FROM GROUNDWATER

    Directory of Open Access Journals (Sweden)

    T. Lupascu

    2013-06-01

    Full Text Available The process of the hydrogen sulfide removal from the underground water of the Hancesti town has been investigated. By oxygen bubbling through the water containing hydrogen sulfide, from the Hancesti well tube, sulfur is deposited in the porous structure of studied catalysts, which decreases their catalytic activity. Concomitantly, the process of adsorption / oxidation of hydrogen sulfide to sulfate take place. The kinetic research of the hydrogen sulfide removal from the Hancesti underground water, after its treatment by hydrogen peroxide, proves greater efficiency than in the case of modified carbonic adsorbents. As a result of used treatment, hydrogen sulfide is completely oxidized to sulfates

  12. Process for low mercury coal

    Science.gov (United States)

    Merriam, Norman W.; Grimes, R. William; Tweed, Robert E.

    1995-01-01

    A process for producing low mercury coal during precombustion procedures by releasing mercury through discriminating mild heating that minimizes other burdensome constituents. Said mercury is recovered from the overhead gases by selective removal.

  13. Mercury (Environmental Health Student Portal)

    Science.gov (United States)

    ... in contact with) to mercury is by eating fish or shellfish that have high levels of mercury. You can also get sick from: Touching it Breathing it in Drinking contaminated water How can mercury ...

  14. Speciation of mercury in soil and sediment by selective solvent and acid extraction

    Energy Technology Data Exchange (ETDEWEB)

    Han, Y. [Metara Inc., 1225 East Arques Ave, Sunnyvale, CA (United States); Kingston, H.M.; Boylan, H.M.; Rahman, G.M.M.; Shah, S.; Richter, R.C.; Link, D.D.; Bhandari, S. [Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA (United States)

    2003-02-01

    In order to characterize the mercury hazard in soil, a sequential extraction scheme has been developed to classify mercury species based on their environmental mobility and/or toxicity for either routine lab analysis or on-site screening purposes. The alkyl mercury species and soluble inorganic species that contribute to the major portion of potential mercury toxicity in the soil are extracted by an acidic ethanol solution (2% HCl+10% ethanol solution) from soil matrices as ''mobile and toxic'' species. A High-Performance Liquid Chromatography (HPLC) system coupled with Inductively Coupled Plasma Mass Spectrometry (ICP-MS) detection has been developed to further resolve the species information into soluble inorganic species (Hg{sup 2+}), methylmercury(II) (MeHg{sup +}) and ethylmercury(II) (EtHg{sup +}) species. Alternatively, these species can be separated into ''soluble inorganic mercury'' and ''alkyl mercury'' sub-categories by Solid-Phase Extraction (SPE). A custom Sulfydryl Cotton Fiber (SCF) material is used as the solid phase medium. Optimization of the SCF SPE technique is discussed. Combined with a direct mercury analyzer (DMA-80), the SCF SPE technique is a promising candidate for on-site screening purposes. Following the ethanol extraction, the inorganic mercury species remaining in soil are further divided into ''semi-mobile'' and ''non-mobile'' sub-categories by sequential acid extractions. The ''semi-mobile'' mercury species include mainly elemental mercury (Hg) and mercury-metal amalgams. The non-mobile mercury species mainly include mercuric sulfide (HgS) and mercurous chloride (Hg{sub 2}Cl{sub 2}). (orig.)

  15. Mercury is Moon's brother

    International Nuclear Information System (INIS)

    Ksanfomalifi, L.V.

    1976-01-01

    The latest information on Mercury planet is presented obtained by studying the planet with the aid of radar and space vehicles. Rotation of Mercury about its axis has been discovered; within 2/3 of its year it executes a complete revolution about its axis. In images obtained by the ''Mariner-10'' Mercurys surface differs little from that of the Moon. The ''Mariner-10'' has also discovered the Mercurys atmosphere, which consists of extremely rarefied helium. The helium is continuously supplied to the planet by the solar wind. The Mercury's magnetic field has been discovered, whose strength is 35 x 10 -4 at the Equator and 70 x 10 -4 E at the poles. The inclination of the dipole axis to the Mercury's rotation axis is 7 deg

  16. Gravity Field and Internal Structure of Mercury from MESSENGER

    Science.gov (United States)

    Smith, David E.; Zuber, Maria T.; Phillips, Roger J.; Solomon, Sean C.; Hauck, Steven A., II; Lemoine, Frank G.; Mazarico, Erwan; Neumann, Gregory A.; Peale, Stanton J.; Margot, Jean-Luc; hide

    2012-01-01

    Radio tracking of the MESSENGER spacecraft has provided a model of Mercury's gravity field. In the northern hemisphere, several large gravity anomalies, including candidate mass concentrations (mascons), exceed 100 milli-Galileos (mgal). Mercury's northern hemisphere crust is thicker at low latitudes and thinner in the polar region and shows evidence for thinning beneath some impact basins. The low-degree gravity field, combined with planetary spin parameters, yields the moment of inertia C/M(R(exp 2) = 0.353 +/- 0.017, where M and R are Mercury's mass and radius, and a ratio of the moment of inertia of Mercury's solid outer shell to that of the planet of C(sub m)/C = 0.452 +/- 0.035. A model for Mercury s radial density distribution consistent with these results includes a solid silicate crust and mantle overlying a solid iron-sulfide layer and an iron-rich liquid outer core and perhaps a solid inner core.

  17. Modeling Mercury in Proteins

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Jeremy C [ORNL; Parks, Jerry M [ORNL

    2016-01-01

    Mercury (Hg) is a naturally occurring element that is released into the biosphere both by natural processes and anthropogenic activities. Although its reduced, elemental form Hg(0) is relatively non-toxic, other forms such as Hg2+ and, in particular, its methylated form, methylmercury, are toxic, with deleterious effects on both ecosystems and humans. Microorganisms play important roles in the transformation of mercury in the environment. Inorganic Hg2+ can be methylated by certain bacteria and archaea to form methylmercury. Conversely, bacteria also demethylate methylmercury and reduce Hg2+ to relatively inert Hg(0). Transformations and toxicity occur as a result of mercury interacting with various proteins. Clearly, then, understanding the toxic effects of mercury and its cycling in the environment requires characterization of these interactions. Computational approaches are ideally suited to studies of mercury in proteins because they can provide a detailed picture and circumvent issues associated with toxicity. Here we describe computational methods for investigating and characterizing how mercury binds to proteins, how inter- and intra-protein transfer of mercury is orchestrated in biological systems, and how chemical reactions in proteins transform the metal. We describe quantum chemical analyses of aqueous Hg(II), which reveal critical factors that determine ligand binding propensities. We then provide a perspective on how we used chemical reasoning to discover how microorganisms methylate mercury. We also highlight our combined computational and experimental studies of the proteins and enzymes of the mer operon, a suite of genes that confers mercury resistance in many bacteria. Lastly, we place work on mercury in proteins in the context of what is needed for a comprehensive multi-scale model of environmental mercury cycling.

  18. LIGNOCELLULOSE NANOCOMPOSITE CONTAINING COPPER SULFIDE

    Directory of Open Access Journals (Sweden)

    Sanchi Nenkova

    2011-04-01

    Full Text Available Copper sulfide-containing lignocellulose nanocomposites with improved electroconductivity were obtained. Two methods for preparing the copper sulfide lignocellulose nanocomposites were developed. An optimization of the parameters for obtaining of the nanocomposites with respect to obtaining improved electroconductivity, economy, and lower quantities and concentration of copper and sulfur ions in waste waters was conducted. The mechanisms and schemes of delaying and subsequent connection of copper sulfides in the lignocellulosic matrix were investigated. The modification with a system of 2 components: cupric sulfate pentahydrate (CuSO4. 5H2O and sodium thiosulfate pentahydrate (Na2S2O3.5H2O for wood fibers is preferred. Optimal parameters were established for the process: 40 % of the reduction system; hydromodule M=1:6; and ratio of cupric sulfate pentahydrate:sodium thiosulfate pentahydrate = 1:2. The coordinative connection of copper ions with oxygen atoms of cellulose OH groups and aromatic nucleus in lignin macromolecule was observed.

  19. Chemical dissolution of sulfide minerals

    Science.gov (United States)

    Chao, T.T.; Sanzolone, R.F.

    1977-01-01

    Chemical dissolution treatments involving the use of aqua regia, 4 N HNO3, H2O2-ascorbic acid, oxalic acid, KClO3+HCl, and KClO3+HCl followed by 4 N HNO3 were applied to specimens of nine common sulfide minerals (galena, chalcopyrite, cinnabar, molybdenite, orpiment, pyrite, stibnite, sphalerite, and tetrahedrite) mixed individually with a clay loam soil. The resultant decrease in the total sulfur content of the mixture, as determined by using the Leco induction furnace, was used to evaluate the effectiveness of each chemical treatment. A combination of KClO3+HCl followed by 4 N HNO3 boiling gently for 20 min has been shown to be very effective in dissolving all the sulfide minerals. This treatment is recommended to dissolve metals residing in sulfide minerals admixed with secondary weathering products, as one step in a fractionation scheme whereby metals in soluble and adsorbed forms, and those associated with organic materials and secondary oxides, are first removed by other chemical extractants.

  20. Intentional intravenous mercury injection

    African Journals Online (AJOL)

    In this case report, intravenous complications, treatment strategies and possible ... Mercury toxicity is commonly associated with vapour inhalation or oral ingestion, for which there exist definite treatment options. Intravenous mercury ... personality, anxiousness, irritability, insomnia, depression and drowsi- ness.[1] However ...

  1. Mercury's shifting, rolling past

    OpenAIRE

    Trulove, Susan

    2008-01-01

    Patterns of scalloped-edged cliffs or lobate scarps on Mercury's surface are thrust faults that are consistent with the planet shrinking and cooling with time. However, compression occurred in the planet's early history and Mariner 10 images revealed decades ago that lobate scarps are among the youngest features on Mercury. Why don't we find more evidence of older compressive features?

  2. Global Mercury Assessment 2013

    International Development Research Centre (IDRC) Digital Library (Canada)

    mercury pollution. This summary report and the accompanying. Technical Background Report for the Global. Mercury Assessment 2013 are developed in response to Decision 25/5, paragraph ... The use of different pollution control technologies in different ...... vegetation, snow, freshwater, and seawater. One of the largest ...

  3. MESSENGER: Exploring Mercury's Magnetosphere

    Science.gov (United States)

    Slavin, James A.

    2008-01-01

    The MESSENGER mission to Mercury offers our first opportunity to explore this planet's miniature magnetosphere since Mariner 10's brief fly-bys in 1974-5. Mercury's magnetosphere is unique in many respects. The magnetosphere of Mercury is the smallest in the solar system with its magnetic field typically standing off the solar wind only - 1000 to 2000 km above the surface. For this reason there are no closed dri-fi paths for energetic particles and, hence, no radiation belts; the characteristic time scales for wave propagation and convective transport are short possibly coupling kinetic and fluid modes; magnetic reconnection at the dayside magnetopause may erode the subsolar magnetosphere allowing solar wind ions to directly impact the dayside regolith; inductive currents in Mercury's interior should act to modify the solar In addition, Mercury's magnetosphere is the only one with its defining magnetic flux tubes rooted in a planetary regolith as opposed to an atmosphere with a conductive ionosphere. This lack of an ionosphere is thought to be the underlying reason for the brevity of the very intense, but short lived, approx. 1-2 min, substorm-like energetic particle events observed by Mariner 10 in Mercury's magnetic tail. In this seminar, we review what we think we know about Mercury's magnetosphere and describe the MESSENGER science team's strategy for obtaining answers to the outstanding science questions surrounding the interaction of the solar wind with Mercury and its small, but dynamic magnetosphere.

  4. Sulfide intrusion and detoxification in seagrasses ecosystems

    DEFF Research Database (Denmark)

    Hasler-Sheetal, Harald; Holmer, Marianne

    Sulfide intrusion in seagrasses represents a global threat to seagrasses and thereby an important parameter in resilience of seagrass ecosystems. In contrast seegrasses colonize and grow in hostile sediments, where they are constantly exposed to invasion of toxic gaseous sulfide. Remarkably little...... strategies of seagrasses to sustain sulfide intrusion. Using stable isotope tracing, scanning electron microscopy with x-ray analysis, tracing sulfur compounds combined with ecosystem parameters we found different spatial, intraspecific and interspecific strategies to cope with sulfidic sediments. 1...... not present in terrestrial plants at that level. Sulfide is not necessarily toxic but used as sulfur nutrition, presupposing healthy seagrass ecosystems that can support detoxification mechanisms. Presence or absence of those mechanisms determines susceptibility of seagrass ecosystems to sediment sulfide...

  5. Mercury in Nordic ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Munthe, John; Waengberg, Ingvar (IVL Swedish Environmental Research Inst., Stockholm (SE)); Rognerud, Sigurd; Fjeld, Eirik (Norwegian Inst. for Water Research (NIVA), Oslo (Norway)); Verta, Matti; Porvari, Petri (Finnish Environment Inst. (SYKE), Helsinki (Finland)); Meili, Markus (Inst. of Applied Environmental Research (ITM), Stockholm (Sweden))

    2007-12-15

    This report provides a first comprehensive compilation and assessment of available data on mercury in air, precipitation, sediments and fish in the Nordic countries. The main conclusion is that mercury levels in Nordic ecosystems continue to be affected by long-range atmospheric transport. The geographical patterns of mercury concentrations in both sediments and fish are also strongly affected by ecosystem characteristics and in some regions possibly by historical pollution. An evaluation of geographical variations in mercury concentrations in precipitation indicates that the influence from anthropogenic sources from Central European areas is still significant. The annual variability of deposition is large and dependant of precipitation amounts. An evaluation of data from stations around the North Sea has indicated a significant decrease in mercury concentrations in precipitation indicating a continuous decrease of emissions in Europe (Waengberg et al., 2007). For mercury in air (TGM), the geographical pattern is less pronounced indicating the influence of mercury emissions and distribution over a larger geographical area (i.e. hemispherical transport). Comparison of recent (surficial) and historical lake sediments show significantly elevated concentrations of mercury most likely caused by anthropogenic atmospheric deposition over the past century. The highest pollution impact was observed in the coastal areas of southern Norway, in south western Finland and in Sweden from the coastal areas in the southwest across the central parts to the north-east. The general increase in recent versus old sediments was 2-5 fold. Data on mercury in Nordic freshwater fish was assembled and evaluated with respect to geographical variations. The fish data were further compared with temporal and spatial trends in mercury deposition and mercury contamination of lake sediments in order to investigate the coupling between atmospheric transport and deposition of mercury and local mercury

  6. Neutron diffraction investigations of the superionic conductors lithium sulfide and sodium sulfide

    International Nuclear Information System (INIS)

    Altorfer, F.

    1990-03-01

    Statics and dynamics of the superionic conductors lithium sulfide and sodium sulfide were investigated using the following experimental methods: elastic scattering on sodium sulfide powder in the temperature range 20 - 1000 C, elastic scattering on a lithium sulfide single crystal in the temperature range 20 - 700 C, inelastic scattering on a 7 Li 2 S single crystal at 10 K. 34 figs., 2 tabs., 10 refs

  7. Getting Mercury out of Schools.

    Science.gov (United States)

    1999

    This guide was prepared while working with many Massachusetts schools to remove items that contain mercury and to find suitable alternatives. It contains fact sheets on: mercury in science laboratories and classrooms, mercury in school buildings and maintenance areas, mercury in the medical office and in medical technology classrooms in vocational…

  8. Sulfidation behavior of Fe20Cr alloys

    International Nuclear Information System (INIS)

    Pillis, Marina Fuser

    2001-01-01

    Alloys for use in high temperature environments rely on the formation of an oxide layer for their protection. Normally, these protective oxides are Cr 2 O 3 , Al 2 O 3 and, some times, SiO 2 . Many industrial gaseous environments contain sulfur. Sulfides, formed in the presence of sulfur are thermodynamically less stable, have lower melting points and deviate much more stoichiometrically, compared to the corresponding oxides. The mechanism of sulfidation of various metals is as yet not clear, in spite of the concerted efforts during the last decade. To help address this situation, the sulfidation behavior of Fe20Cr has been studied as a function of compositional modifications and surface state of the alloy. The alloys Fe20Cr, Fe20Cr0.7Y, Fe20Cr5Al and Fe20Cr5Al0.6Y were prepared and three sets of sulfidation tests were carried out. In the first set, the alloys were sulfidized at 700 deg C and 800 deg C for 10h. In the second set, the alloys were pre-oxidized at 1000 deg C and then sulfidized at 800 deg C for up to 45h. In the third set of tests, the initial stages of sulfidation of the alloys was studied. All the tests were carried out in a thermobalance, in flowing H 2 /2%H 2 S, and the sulfidation behavior determined as mass change per unit area. Scanning electron microscopy coupled to energy dispersive spectroscopy and X-ray diffraction analysis were used to characterize the reaction products. The addition of Y and Al increased sulfidation resistance of Fe20Cr. The addition of Y altered the species that diffused predominantly during sulfide growth. It changed from predominant cationic diffusion to predominant anionic diffusion. The addition of Al caused an even greater increase in sulfidation resistance of Fe20Cr, with the parabolic rate constant decreasing by three orders of magnitude. Y addition to the FeCrAl alloy did not cause any appreciable alteration in sulfidation resistance. Pre-oxidation of the FeCrAl and FeCrAlY alloys resulted in an extended

  9. Mercury and trace element contents of Donbas coals and associated mine water in the vicinity of Donetsk, Ukraine

    Science.gov (United States)

    Kolker, A.; Panov, B.S.; Panov, Y.B.; Landa, E.R.; Conko, K.M.; Korchemagin, V.A.; Shendrik, T.; McCord, J.D.

    2009-01-01

    Mercury-rich coals in the Donets Basin (Donbas region) of Ukraine were sampled in active underground mines to assess the levels of potentially harmful elements and the potential for dispersion of metals through use of this coal. For 29 samples representing c11 to m3 Carboniferous coals, mercury contents range from 0.02 to 3.5 ppm (whole-coal dry basis). Mercury is well correlated with pyritic sulfur (0.01 to 3.2 wt.%), with an r2 of 0.614 (one outlier excluded). Sulfides in these samples show enrichment of minor constituents in late-stage pyrite formed as a result of interaction of coal with hydrothermal fluids. Mine water sampled at depth and at surface collection points does not show enrichment of trace metals at harmful levels, indicating pyrite stability at subsurface conditions. Four samples of coal exposed in the defunct open-cast Nikitovka mercury mines in Gorlovka have extreme mercury contents of 12.8 to 25.5 ppm. This coal was formerly produced as a byproduct of extracting sandstone-hosted cinnabar ore. Access to these workings is unrestricted and small amounts of extreme mercury-rich coal are collected for domestic use, posing a limited human health hazard. More widespread hazards are posed by the abandoned Nikitovka mercury processing plant, the extensive mercury mine tailings, and mercury enrichment of soils extending into residential areas of Gorlovka.

  10. Iodide-Photocatalyzed Reduction of Carbon Dioxide to Formic Acid with Thiols and Hydrogen Sulfide.

    Science.gov (United States)

    Berton, Mateo; Mello, Rossella; González-Núñez, María Elena

    2016-12-20

    The photolysis of iodide anions promotes the reaction of carbon dioxide with hydrogen sulfide or thiols to quantitatively yield formic acid and sulfur or disulfides. The reaction proceeds in acetonitrile and aqueous solutions, at atmospheric pressure and room temperature by irradiation using a low-pressure mercury lamp. This transition-metal-free photocatalytic process for CO 2 capture coupled with H 2 S removal may have been relevant as a prebiotic carbon dioxide fixation. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Comparing and assessing different measurement techniques for mercury in coal systhesis gas

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, D.P.; Richardson, C.F. [Radian Corporation, Austin, TX (United States)

    1995-11-01

    Three mercury measurement techniques were performed on synthesis gas streams before and after an amine-based sulfur removal system. The syngas was sampled using (1) gas impingers containing a nitric acid-hydrogen peroxide solution, (2) coconut-based charcoal sorbent, and (3) an on-line atomic absorption spectrophotometer equipped with a gold amalgamation trap and cold vapor cell. Various impinger solutions were applied upstream of the gold amalgamation trap to remove hydrogen sulfide and isolate oxidized and elemental species of mercury. The results from these three techniques are compared to provide an assessment of these measurement techniques in reducing gas atmospheres.

  12. Mercury's Dynamic Magnetic Tail

    Science.gov (United States)

    Slavin, James A.

    2010-01-01

    The Mariner 10 and MESSENGER flybys of Mercury have revealed a magnetosphere that is likely the most responsive to upstream interplanetary conditions of any in the solar system. The source of the great dynamic variability observed during these brief passages is due to Mercury's proximity to the Sun and the inverse proportionality between reconnection rate and solar wind Alfven Mach number. However, this planet's lack of an ionosphere and its small physical dimensions also contribute to Mercury's very brief Dungey cycle, approx. 2 min, which governs the time scale for internal plasma circulation. Current observations and understanding of the structure and dynamics of Mercury's magnetotail are summarized and discussed. Special emphasis will be placed upon such questions as: 1) How much access does the solar wind have to this small magnetosphere as a function of upstream conditions? 2) What roles do heavy planetary ions play? 3) Do Earth-like substorms take place at Mercury? 4) How does Mercury's tail respond to extreme solar wind events such coronal mass ejections? Prospects for progress due to advances in the global magnetohydrodynamic and hybrid simulation modeling and the measurements to be taken by MESSENGER after it enters Mercury orbit on March 18, 2011 will be discussed.

  13. Disposal strategy of proton irradiated mercury from high power spallation sources

    International Nuclear Information System (INIS)

    Chiriki, Suresh

    2010-01-01

    Large spallation sources are intended to be constructed in Europe (EURISOL: nuclear physics research facility and ESS: European Spallation Source). These facilities would accumulate more than 20 metric tons of irradiated mercury in the target, which has to be treated as highly radioactive and chemo-toxic waste. Liquid waste cannot be tolerated in European repositories. As part of this work on safety/decommissioning of high-power spallation sources, our investigations were focused mainly to study experimentally and theoretically the solidification of liquid mercury waste (selection of an adequate solid mercury form and of an immobilization matrix, chemical engineering process studies on solidification/stabilization and on encapsulating in a matrix). Based on experimental results and supported by literature Hg-chalcogens (HgS, HgSe) will be more stable in repositories than amalgams. Our irradiation experimental studies on mercury waste revealed that mercury sulfide is a reasonable solid for disposal and shows larger stability in possible accidents with water ingress in a repository. Additionally immobilization of mercury in a cement matrix and polysiloxane matrix were tested. HgS formation from liquid target mercury by a wet process is identified as a suitable formation procedure. These investigations reveal that an almost 99.9% elementary Hg conversion can be achieved and that wet process can be reasonably handled under hot cell conditions. (orig.)

  14. Using Sulfate-Amended Sediment Slurry Batch Reactors to Evaluate Mercury Methylation

    International Nuclear Information System (INIS)

    Harmon, S.M.

    2003-01-01

    In the methylated form, mercury represents a concern to public health primarily through the consumption of contaminated fish tissue. Research conducted on the methylation of mercury strongly suggests the process is microbial in nature and facilitated principally by sulfate-reducing bacteria. This study addressed the potential for mercury methylation by varying sulfate treatments and wetland-based soil in microbial slurry reactors with available inorganic mercury. Under anoxic laboratory conditions conducive to growth of naturally occurring sulfate-reducing bacteria in the soil, it was possible to evaluate how various sulfate additions influenced the methylation of inorganic mercury added to overlying water. Treatments included sulfate amendments ranging FR-om 25 to 500 mg/L (0.26 to 5.2 mM) above the soil's natural sulfate level. This study also provided an assessment of mercury methylation relative to sulfate-reducing bacterial population growth and subsequent sulfide production. Mercury methylation in sulfate treatments did not exceed that of the non-amended control during a 35-day incubation. However, increases in methylmercury concentration were linked to bacterial growth and sulfate reduction. A time lag in methylation in the highest treatment correlated with an equivalent lag in bacterial growth

  15. Disposal strategy of proton irradiated mercury from high power spallation sources

    Energy Technology Data Exchange (ETDEWEB)

    Chiriki, Suresh

    2010-07-01

    Large spallation sources are intended to be constructed in Europe (EURISOL: nuclear physics research facility and ESS: European Spallation Source). These facilities would accumulate more than 20 metric tons of irradiated mercury in the target, which has to be treated as highly radioactive and chemo-toxic waste. Liquid waste cannot be tolerated in European repositories. As part of this work on safety/decommissioning of high-power spallation sources, our investigations were focused mainly to study experimentally and theoretically the solidification of liquid mercury waste (selection of an adequate solid mercury form and of an immobilization matrix, chemical engineering process studies on solidification/stabilization and on encapsulating in a matrix). Based on experimental results and supported by literature Hg-chalcogens (HgS, HgSe) will be more stable in repositories than amalgams. Our irradiation experimental studies on mercury waste revealed that mercury sulfide is a reasonable solid for disposal and shows larger stability in possible accidents with water ingress in a repository. Additionally immobilization of mercury in a cement matrix and polysiloxane matrix were tested. HgS formation from liquid target mercury by a wet process is identified as a suitable formation procedure. These investigations reveal that an almost 99.9% elementary Hg conversion can be achieved and that wet process can be reasonably handled under hot cell conditions. (orig.)

  16. Total Mercury content of skin toning creams

    African Journals Online (AJOL)

    Administrator

    2008-04-01

    Apr 1, 2008 ... used it for cosmetics (Silberberg, 1995). Mercury- ... Cosmetic preparations containing mercury com- pounds are .... mercury determination by a modified version of an open .... level mercury exposure, which could lead to a.

  17. Recovery of mercury from mercury compounds via electrolytic methods

    Science.gov (United States)

    Grossman, Mark W.; George, William A.

    1988-01-01

    A process for electrolytically recovering mercury from mercury compounds is provided. In one embodiment, Hg is recovered from Hg.sub.2 Cl.sub.2 employing as the electrolyte solution a mixture of HCl and H.sub.2 O. In another embodiment, Hg is electrolytically recovered from HgO wherein the electrolyte solution is comprised of glacial acetic acid and H.sub.2 O. Also provided is an apparatus for producing isotopically enriched mercury compounds in a reactor and then transporting the dissolved compounds into an electrolytic cell where mercury ions are electrolytically reduced and elemental mercury recovered from the mercury compounds.

  18. Sulfide toxicity kinetics of a uasb reactor

    Directory of Open Access Journals (Sweden)

    D. R. Paula Jr.

    2009-12-01

    Full Text Available The effect of sulfide toxicity on kinetic parameters of anaerobic organic matter removal in a UASB (up-flow anaerobic sludge blanket reactor is presented. Two lab-scale UASB reactors (10.5 L were operated continuously during 12 months. The reactors were fed with synthetic wastes prepared daily using glucose, ammonium acetate, methanol and nutrient solution. One of the reactors also received increasing concentrations of sodium sulfide. For both reactors, the flow rate of 16 L.d-1 was held constant throughout the experiment, corresponding to a hydraulic retention time of 15.6 hours. The classic model for non-competitive sulfide inhibition was applied to the experimental data for determining the overall kinetic parameter of specific substrate utilization (q and the sulfide inhibition coefficient (Ki. The application of the kinetic parameters determined allows prediction of methanogenesis inhibition and thus the adoption of operating parameters to minimize sulfide toxicity in UASB reactors.

  19. Metallic mercury recycling. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Beck, M.A.

    1994-07-01

    Metallic mercury is known to be a hazardous material and is regulated as such. The disposal of mercury, usually by landfill, is expensive and does not remove mercury from the environment. Results from the Metallic Mercury Recycling Project have demonstrated that metallic mercury is a good candidate for reclamation and recycling. Most of the potential contamination of mercury resides in the scum floating on the surface of the mercury. Pinhole filtration was demonstrated to be an inexpensive and easy way of removing residues from mercury. The analysis method is shown to be sufficient for present release practices, and should be sufficient for future release requirements. Data from tests are presented. The consistently higher level of activity of the filter residue versus the bulk mercury is discussed. Recommendations for the recycling procedure are made.

  20. Metallic mercury recycling. Final report

    International Nuclear Information System (INIS)

    Beck, M.A.

    1994-01-01

    Metallic mercury is known to be a hazardous material and is regulated as such. The disposal of mercury, usually by landfill, is expensive and does not remove mercury from the environment. Results from the Metallic Mercury Recycling Project have demonstrated that metallic mercury is a good candidate for reclamation and recycling. Most of the potential contamination of mercury resides in the scum floating on the surface of the mercury. Pinhole filtration was demonstrated to be an inexpensive and easy way of removing residues from mercury. The analysis method is shown to be sufficient for present release practices, and should be sufficient for future release requirements. Data from tests are presented. The consistently higher level of activity of the filter residue versus the bulk mercury is discussed. Recommendations for the recycling procedure are made

  1. The tectonics of Mercury

    International Nuclear Information System (INIS)

    Melosh, H.J.; Mckinnon, W.B.

    1988-01-01

    The probable tectonic history of Mercury and the relative sequence of events are discussed on the basis of data collected by the Mariner-10 spacecraft. Results indicate that Mercury's tectonic activity was confined to its early history; its endogenic activity was principally due to a small change in the shape of its lithosphere, caused by tidal despinning, and a small change in area caused by shrinkage due to cooling. Exogenic processes, in particular the impact activity, have produced more abundant tectonic features. Many features associated with the Caloris basin are due to loading of Mercury's thick lithosphere by extrusive lavas or subsidence due to magma withdrawal. It is emphasized that tectonic features observed on Mercury yield insight into the earliest tectonic events on planets like Mars and, perhaps, the earth, where subsequent events obscured or erased the most ancient tectonic records

  2. Intentional intravenous mercury injection

    African Journals Online (AJOL)

    Elemental mercury is the well-known silver liquid and usually causes pulmonary, neurological and ... suicidal ideation or features of major depression. Clinically the patient was .... medically at this stage and consider surgical intervention later.

  3. Mercury's Dynamic Magnetosphere

    Science.gov (United States)

    Imber, S. M.

    2018-05-01

    The global dynamics of Mercury's magnetosphere will be discussed, focussing on observed asymmetries in the magnetotail and on the precipitation of particles of magnetospheric origin onto the nightside planetary surface.

  4. Mercury analysis in hair

    DEFF Research Database (Denmark)

    Esteban, Marta; Schindler, Birgit K; Jiménez-Guerrero, José A

    2015-01-01

    Human biomonitoring (HBM) is an effective tool for assessing actual exposure to chemicals that takes into account all routes of intake. Although hair analysis is considered to be an optimal biomarker for assessing mercury exposure, the lack of harmonization as regards sampling and analytical...... assurance program (QAP) for assessing mercury levels in hair samples from more than 1800 mother-child pairs recruited in 17 European countries. To ensure the comparability of the results, standard operating procedures (SOPs) for sampling and for mercury analysis were drafted and distributed to participating...... laboratories. Training sessions were organized for field workers and four external quality-assessment exercises (ICI/EQUAS), followed by the corresponding web conferences, were organized between March 2011 and February 2012. ICI/EQUAS used native hair samples at two mercury concentration ranges (0...

  5. Mercury's Early Geologic History

    Science.gov (United States)

    Denevi, B. W.; Ernst, C. M.; Klima, R. L.; Robinson, M. S.

    2018-05-01

    A combination of geologic mapping, compositional information, and geochemical models are providing a better understanding of Mercury's early geologic history, and allow us to place it in the context of the Moon and the terrestrial planets.

  6. In Vitro Studies Evaluating Leaching of Mercury from Mine Waste Calcine Using Simulated Human Body Fluids

    OpenAIRE

    Gray, John E.; Plumlee, Geoffrey S.; Morman, Suzette A.; Higueras, Pablo L.; Crock, James G.; Lowers, Heather A.; Witten, Mark L.

    2010-01-01

    In vitro bioaccessibility (IVBA) studies were carried out on samples of mercury (Hg) mine-waste calcine (roasted Hg ore) by leaching with simulated human body fluids. The objective was to estimate potential human exposure to Hg due to inhalation of airborne calcine particulates and hand-to-mouth ingestion of Hg-bearing calcines. Mine waste calcines collected from Hg mines at Almad?n, Spain, and Terlingua, Texas, contain Hg sulfide, elemental Hg, and soluble Hg compounds, which constitute prim...

  7. Mercury CEM Calibration

    Energy Technology Data Exchange (ETDEWEB)

    John F. Schabron; Joseph F. Rovani; Susan S. Sorini

    2007-03-31

    The Clean Air Mercury Rule (CAMR) which was published in the Federal Register on May 18, 2005, requires that calibration of mercury continuous emissions monitors (CEMs) be performed with NIST-traceable standards. Western Research Institute (WRI) is working closely with the Electric Power Research Institute (EPRI), the National Institute of Standards and Technology (NIST), and the Environmental Protection Agency (EPA) to facilitate the development of the experimental criteria for a NIST traceability protocol for dynamic elemental mercury vapor generators. The traceability protocol will be written by EPA. Traceability will be based on the actual analysis of the output of each calibration unit at several concentration levels ranging from about 2-40 ug/m{sup 3}, and this analysis will be directly traceable to analyses by NIST using isotope dilution inductively coupled plasma/mass spectrometry (ID ICP/MS) through a chain of analyses linking the calibration unit in the power plant to the NIST ID ICP/MS. Prior to this project, NIST did not provide a recommended mercury vapor pressure equation or list mercury vapor pressure in its vapor pressure database. The NIST Physical and Chemical Properties Division in Boulder, Colorado was subcontracted under this project to study the issue in detail and to recommend a mercury vapor pressure equation that the vendors of mercury vapor pressure calibration units can use to calculate the elemental mercury vapor concentration in an equilibrium chamber at a particular temperature. As part of this study, a preliminary evaluation of calibration units from five vendors was made. The work was performed by NIST in Gaithersburg, MD and Joe Rovani from WRI who traveled to NIST as a Visiting Scientist.

  8. Cutaneous mercury granuloma

    OpenAIRE

    Kalpana A Bothale; Sadhana D Mahore; Sushil Pande; Trupti Dongre

    2013-01-01

    Cutaneous mercury granuloma is rarely encountered. Clinically it may pose difficulty in diagnosis. Here, we report a 23-year-old male presented with erythematous, nodular lesions over the forearm and anterior aspect of chest wall. Metallic mercury in tissue sections appear as dark black, opaque, spherical globules of varying size and number. They are surrounded by granulomatous foreign-body reaction. It is composed of foreign body giant cells and mixed inflammatory infiltrate composed of hist...

  9. Mercury in human hair

    International Nuclear Information System (INIS)

    Kapauan, P.A.; Cruz, C.C.; Verceluz, F.P.

    1980-10-01

    The analysis of mercury (Hg) in scalp hair obtained from individuals residing in five different localities in the Philippines - Metro Manila, Naga City in Bicol, Bataan, Oriental Mindoro, and Palawan is presented. An overall mean of 1.46 ug/g of hair was obtained for all samples excluding those from Palawan and represents a baseline value.'' In terms of the mercury levels found in hair, the Honda Bay area in Palawan is, relatively, a ''contaminated area.'' (author)

  10. Method and apparatus for monitoring mercury emissions

    Science.gov (United States)

    Durham, Michael D.; Schlager, Richard J.; Sappey, Andrew D.; Sagan, Francis J.; Marmaro, Roger W.; Wilson, Kevin G.

    1997-01-01

    A mercury monitoring device that continuously monitors the total mercury concentration in a gas. The device uses the same chamber for converting speciated mercury into elemental mercury and for measurement of the mercury in the chamber by radiation absorption techniques. The interior of the chamber is resistant to the absorption of speciated and elemental mercury at the operating temperature of the chamber.

  11. Mercury isotope constraints on the source for sediment-hosted lead-zinc deposits in the Changdu area, southwestern China

    Science.gov (United States)

    Xu, Chunxia; Yin, Runsheng; Peng, Jiantang; Hurley, James P.; Lepak, Ryan F.; Gao, Jianfeng; Feng, Xinbin; Hu, Ruizhong; Bi, Xianwu

    2018-03-01

    The Lanuoma and Cuona sediment-hosted Pb-Zn deposits hosted by Upper Triassic limestone and sandstone, respectively, are located in the Changdu area, SW China. Mercury concentrations and Hg isotopic compositions from sulfide minerals and potential source rocks (e.g., the host sedimentary rocks and the metamorphic basement) were investigated to constrain metal sources and mineralization processes. In both deposits, sulfide minerals have higher mercury (Hg) concentrations (0.35 to 1185 ppm) than the metamorphic basement rocks (0.05 to 0.15 ppm) and sedimentary rocks (0.02 to 0.08 ppm). Large variations of mass-dependent fractionation (3.3‰ in δ202Hg) and mass-independent fractionation (0.3‰ in Δ199Hg) of Hg isotopes were observed. Sulfide minerals have Hg isotope signatures that are similar to the hydrothermal altered rocks around the deposit, and similar to the metamorphic basement, but different from barren sedimentary rocks. The variation of Δ199Hg suggests that Hg in sulfides was mainly derived from the underlying metamorphic basement. Mercury isotopes could be a geochemical tracer in understanding metal sources in hydrothermal ore deposits.

  12. Mercury pollution in Malaysia.

    Science.gov (United States)

    Hajeb, Parvaneh; Jinap, S; Ismail, Ahmad; Mahyudin, Nor Ainy

    2012-01-01

    Although several studies have been published on levels of mercury contamination of the environment, and of food and human tissues in Peninsular Malaysia, there is a serious dearth of research that has been performed in East Malaysia (Sabah and Sarawak). Industry is rapidly developing in East Malaysia, and, hence, there is a need for establishing baseline levels of mercury contamination in environmental media in that part of the country by performing monitoring studies. Residues of total mercury and inorganic in food samples have been determined in nearly all previous studies that have been conducted; however, few researchers have analyzed samples for the presence of methlymercury residues. Because methylmercury is the most toxic form of mercury, and because there is a growing public awareness of the risk posed by methylmercury exposure that is associated with fish and seafood consumption, further monitoring studies on methylmercury in food are also essential. From the results of previous studies, it is obvious that the economic development in Malaysia, in recent years, has affected the aquatic environment of the country. Primary areas of environmental concern are centered on the rivers of the west Peninsular Malaysian coast, and the coastal waters of the Straits of Malacca, wherein industrial activities are rapidly expanding. The sources of existing mercury input to both of these areas of Malaysia should be studied and identified. Considering the high levels of mercury that now exists in human tissues, efforts should be continued, and accelerated in the future, if possible, to monitor mercury contamination levels in the coastal states, and particularly along the west Peninsular Malaysian coast. Most studies that have been carried out on mercury residues in environmental samples are dated, having been conducted 20-30 years ago; therefore, the need to collect much more and more current data is urgent. Furthermore, establishing baseline levels of mercury exposure to

  13. Sulfidation/oxidation resistant alloys

    International Nuclear Information System (INIS)

    Smith, G.D.; Tassen, C.S.

    1989-01-01

    The patent describes a nickel-base, high chromium alloy. It is characterized by excellent resistance to sulfidation and oxidation at elevated temperatures as high as 2000 degrees F. (1093 degrees C.) and higher, a stress-rupture life of about 200 hours or more at a temperature at least as high as 1800 degrees F. (990:0083 degrees C.) and under a stress of 2000 psi, good tensile strength and good ductility both at room and elevated temperature. The alloy consists essentially of about 27 to 35% chromium, about 2.5 to 5% aluminum, about 2.5 to about 6% iron, 0.5 to 2.5% columbium, up to 0.1% carbon, up to 1% each of titanium and zirconium, up to 0.05% cerium, up to 0.05% yttrium, up to 1% silicon, up to 1% manganese, and the balance nickel

  14. Mercury Quick Facts: Health Effects of Mercury Exposure

    Science.gov (United States)

    ... 2012 What are the Health Effects of Mercury Exposure? The health effects that can be caused by breathing mercury depend ... they breathe faster and have smaller lungs. Health effects caused by long-term exposure to mercury vapors • • Anxiety • • Excessive shyness • • Anorexia • • Sleeping ...

  15. Iron-sulfide crystals in probe deposits

    DEFF Research Database (Denmark)

    Laursen, Karin; Frandsen, Flemming

    1998-01-01

    Iron-sulfides were observed in deposits collected on a probe inserted at the top of the furnace of a coal-fired power station in Denmark. The chemical composition of the iron-sulfides is equivalent to pyrrhotite (FeS). The pyrrhotites are present as crystals and, based on the shape of the crystals......: (1) impact of low viscous droplets of iron sulfide; and (2) sulfur diffusion. Previous research on the influence of pyrite on slagging focused on the decomposition of pyrite into pyrrhotite and especially on the oxidation stage of this product during impact on the heat transfer surfaces...

  16. Microbial control of hydrogen sulfide production

    Energy Technology Data Exchange (ETDEWEB)

    Montgomery, A.D.; Bhupathiraju, V.K.; Wofford, N.; McInerney, M.J. [Univ. of Oklahoma, Tulsa, OK (United States)] [and others

    1995-12-31

    A sulfide-resistant strain of Thiobacillus denitrificans, strain F, prevented the accumulation of sulfide by Desulfovibrio desulfuricans when both organisms were grown in liquid medium. The wild-type strain of T. denitrificans did not prevent the accumulation of sulfide produced by D. desulfuricans. Strain F also prevented the accumulation of sulfide by a mixed population of sulfate-reducing bacteria enriched from an oil field brine. Fermentation balances showed that strain F stoichiometrically oxidized the sulfide produced by D. desulfuricans and the oil field brine enrichment to sulfate. The ability of a strain F to control sulfide production in an experimental system of cores and formation water from the Redfield, Iowa, natural gas storage facility was also investigated. A stable, sulfide-producing biofilm was established in two separate core systems, one of which was inoculated with strain F while the other core system (control) was treated in an identical manner, but was not inoculated with strain F. When formation water with 10 mM acetate and 5 mM nitrate was injected into both core systems, the effluent sulfide concentrations in the control core system ranged from 200 to 460 {mu}M. In the test core system inoculated with strain F, the effluent sulfide concentrations were lower, ranging from 70 to 110 {mu}M. In order to determine whether strain F could control sulfide production under optimal conditions for sulfate-reducing bacteria, the electron donor was changed to lactate and inorganic nutrients (nitrogen and phosphate sources) were added to the formation water. When nutrient-supplemented formation water with 3.1 mM lactate and 10 mM nitrate was used, the effluent sulfide concentrations of the control core system initially increased to about 3,800 {mu}M, and then decreased to about 1,100 {mu}M after 5 weeks. However, in the test core system inoculated with strain F, the effluent sulfide concentrations were much lower, 160 to 330 {mu}M.

  17. Mercury pOIsonIng

    African Journals Online (AJOL)

    A case of mercury poisoning is reported and clinical observations of 6 .... fish ingested and occupational exposure. .... exposed to mercury as a result of inadequate industrial safety standards, and ... WHO Tech Rep Ser 1980; No. 674: 102-115.

  18. Mercury Study Report to Congress

    Science.gov (United States)

    EPA's Report to Congress on Mercury provides an assessment of the magnitude of U.S. mercury emissions by source, the health and environmental implications of those emissions, and the availability and cost of control technologies.

  19. True Polar Wander of Mercury

    Science.gov (United States)

    Keane, J. T.; Matsuyama, I.

    2018-05-01

    We use new MESSENGER gravity data to investigate how impact basins and volcanic provinces alter Mercury's moments of inertia. We find that Mercury has reoriented tens of degrees over its history, affecting tectonics, volatiles, and more.

  20. Mercury Emissions: The Global Context

    Science.gov (United States)

    Mercury emissions are a global problem that knows no national or continental boundaries. Mercury that is emitted to the air can travel thousands of miles in the atmosphere before it is eventually deposited back to the earth.

  1. Sulfide Intrusion and Detoxification in the Seagrass Zostera marina

    DEFF Research Database (Denmark)

    Hasler-Sheetal, Harald; Holmer, Marianne

    2015-01-01

    Gaseous sulfide intrusion into seagrasses growing in sulfidic sediments causes little or no harm to the plant, indicating the presence of an unknown sulfide tolerance or detoxification mechanism. We assessed such mechanism in the seagrass Zostera marina in the laboratory and in the field...... as sulfate throughout the plant. We conclude that avoidance of sulfide exposure by reoxidation of sulfide in the rhizosphere or aerenchyma and tolerance of sulfide intrusion by incorporation of sulfur in the plant are likely major survival strategies of seagrasses in sulfidic sediments....

  2. Human and ecological remediation goals for soil mercury at East Fork Poplar Creek, Oak Ridge, TN

    International Nuclear Information System (INIS)

    Zafran, F.A.; Cornaby, B.W.; Hadden, C.T.

    1995-01-01

    Mercury, used in the past production of enriched lithium by the Department of Energy, is the principal chemical of concern in the 14-mile floodplain of East Fork Poplar Creek (EFPC). SAIC has developed risk-based remediation goal options (RGOS) for mercury in EFPC soils to protect the most sensitive human receptors. The existing chronic oral RfD for mercury is based on exposure of laboratory species to mercuric chloride. However, speciation and leaching/availability studies (conducted by EPA EMSL and Oak Ridge National Laboratory) indicated less soluble and less toxic mercury species, principally mercuric sulfide, with measurable quantities of metallic mercury also present, predominate in EFPC floodplain soils. SAIC derived human health RGOs using deterministic and probabilistic methods and incorporated the probability density function for bioavailability of mercury species from leaching/availability data generated by ORNL. Monte Carlo simulation was used in uncertainty analysis and supported the derivation of a protective, but realistic risk-based remediation goal of 400 mg mercury/kg soil. For ecological risk assessment, RGOs were based on risks through food chains from contaminants in soil. The authors describe a terrestrial food-chain model of contaminant transfer to primary producers, first-order consumers, mid-level predators, and top-level predators. The model uses published toxicity data, site-specific contaminant concentrations, and bioaccumulation factors calculated from measured body burdens of floodplain organisms to compute RGOs for various combinations of exposure parameters. Model calculations show that under reasonably conservative conditions, mid-level predators have the highest exposures relative to dietary limits and, therefore, require the lowest soil-mercury RGOs. Mercury concentrations of ∼500 mg/kg are protective of the receptor populations exposed through food chains at this site

  3. Mercury's magnetic field and interior

    International Nuclear Information System (INIS)

    Connerney, J.E.P.; Ness, N.F.

    1988-01-01

    The magnetic-field data collected on Mercury by the Mariner-10 spacecraft present substantial evidence for an intrinsic global magnetic field. However, studies of Mercury's thermal evolution show that it is most likely that the inner core region of Mercury solidified or froze early in the planet's history. Thus, the explanation of Mercury's magnetic field in the framework of the traditional planetary dynamo is less than certain

  4. Mercury in coal and the impact of coal quality on mercury emissions from combustion systems

    International Nuclear Information System (INIS)

    Kolker, Allan; Senior, Constance L.; Quick, Jeffrey C.

    2006-01-01

    The proportion of Hg in coal feedstock that is emitted by stack gases of utility power stations is a complex function of coal chemistry and properties, combustion conditions, and the positioning and type of air pollution control devices employed. Mercury in bituminous coal is found primarily within Fe-sulfides, whereas lower rank coal tends to have a greater proportion of organic-bound Hg. Preparation of bituminous coal to reduce S generally reduces input Hg relative to in-ground concentrations, but the amount of this reduction varies according to the fraction of Hg in sulfides and the efficiency of sulfide removal. The mode of occurrence of Hg in coal does not directly affect the speciation of Hg in the combustion flue gas. However, other constituents in the coal, notably Cl and S, and the combustion characteristics of the coal, influence the species of Hg that are formed in the flue gas and enter air pollution control devices. The formation of gaseous oxidized Hg or particulate-bound Hg occurs post-combustion; these forms of Hg can be in part captured in the air pollution control devices that exist on coal-fired boilers, without modification. For a given coal type, the capture efficiency of Hg by pollution control systems varies according to type of device and the conditions of its deployment. For bituminous coal, on average, more than 60% of Hg in flue gas is captured by fabric filter (FF) and flue-gas desulfurization (FGD) systems. Key variables affecting performance for Hg control include Cl and S content of the coal, the positioning (hot side vs. cold side) of the system, and the amount of unburned C in coal ash. Knowledge of coal quality parameters and their effect on the performance of air pollution control devices allows optimization of Hg capture co-benefit

  5. MERCURY IN MARINE LIFE DATABASE

    Science.gov (United States)

    The purpose of the Mercury in Marine Life Project is to organize information on estuarine and marine species so that EPA can better understand both the extent of monitoring for mercury and level of mercury contamination in the biota of coastal environments. This report follows a ...

  6. Reference Atmosphere for Mercury

    Science.gov (United States)

    Killen, Rosemary M.

    2002-01-01

    We propose that Ar-40 measured in the lunar atmosphere and that in Mercury's atmosphere is due to current diffusion into connected pore space within the crust. Higher temperatures at Mercury, along with more rapid loss from the atmosphere will lead to a smaller column abundance of argon at Mercury than at the Moon, given the same crustal abundance of potassium. Because the noble gas abundance in the Hermean atmosphere represents current effusion, it is a direct measure of the crustal potassium abundance. Ar-40 in the atmospheres of the planets is a measure of potassium abundance in the interiors, since Ar-40 is a product of radiogenic decay of K-40 by electron capture with the subsequent emission of a 1.46 eV gamma-ray. Although the Ar-40 in the Earth's atmosphere is expected to have accumulated since the late bombardment, Ar-40 in the atmospheres of Mercury and the Moon is eroded quickly by photoionization and electron impact ionization. Thus, the argon content in the exospheres of the Moon and Mercury is representative of current effusion rather than accumulation over the lifetime of the planet.

  7. Crossett Hydrogen Sulfide Air Sampling Report

    Science.gov (United States)

    This report summarizes the results of the EPA’s hydrogen sulfide air monitoring conducted along Georgia Pacific’s wastewater treatment system and in surrounding Crossett, AR, neighborhoods in 2017.

  8. Water displacement mercury pump

    Science.gov (United States)

    Nielsen, M.G.

    1984-04-20

    A water displacement mercury pump has a fluid inlet conduit and diffuser, a valve, a pressure cannister, and a fluid outlet conduit. The valve has a valve head which seats in an opening in the cannister. The entire assembly is readily insertable into a process vessel which produces mercury as a product. As the mercury settles, it flows into the opening in the cannister displacing lighter material. When the valve is in a closed position, the pressure cannister is sealed except for the fluid inlet conduit and the fluid outlet conduit. Introduction of a lighter fluid into the cannister will act to displace a heavier fluid from the cannister via the fluid outlet conduit. The entire pump assembly penetrates only a top wall of the process vessel, and not the sides or the bottom wall of the process vessel. This insures a leak-proof environment and is especially suitable for processing of hazardous materials.

  9. Air-water transfer of hydrogen sulfide

    DEFF Research Database (Denmark)

    Yongsiri, C.; Vollertsen, J.; Rasmussen, M. R.

    2004-01-01

    The emissions process of hydrogen sulfide was studied to quantify air–water transfer of hydrogen sulfide in sewer networks. Hydrogen sulfide transfer across the air–water interface was investigated at different turbulence levels (expressed in terms of the Froude number) and pH using batch...... experiments. By means of the overall mass–transfer coefficient (KLa), the transfer coefficient of hydrogen sulfide (KLaH2S), referring to total sulfide, was correlated to that of oxygen (KLaO2) (i.e., the reaeration coefficient). Results demonstrate that both turbulence and pH in the water phase play...... a significant role for KLaH2S. An exponential expression is a suitable representation for the relationship between KLaH2S and the Froude number at all pH values studied (4.5 to 8.0). Because of the dissociation of hydrogen sulfide, KLaH2S increased with decreasing pH at a constant turbulence level. Relative...

  10. Mercury exposure in Ireland

    DEFF Research Database (Denmark)

    Cullen, Elizabeth; Evans, David S; Davidson, Fred

    2014-01-01

    of a study to Coordinate and Perform Human Biomonitoring on a European Scale (DEMOCOPHES) pilot biomonitoring study. METHODS: Hair mercury concentrations were determined from a convenience sample of 120 mother/child pairs. Mothers also completed a questionnaire. Rigorous quality assurance within DEMOCOPHES...... guaranteed the accuracy and international comparability of results. RESULTS: Mercury was detected in 79.2% of the samples from mothers, and 62.5% of children's samples. Arithmetic mean levels in mothers (0.262 µg/g hair) and children (0.149 µg /g hair) did not exceed the US EPA guidance value. Levels were...

  11. Mercury CEM Calibration

    Energy Technology Data Exchange (ETDEWEB)

    John Schabron; Joseph Rovani; Mark Sanderson

    2008-02-29

    Mercury continuous emissions monitoring systems (CEMS) are being implemented in over 800 coal-fired power plant stacks. The power industry desires to conduct at least a full year of monitoring before the formal monitoring and reporting requirement begins on January 1, 2009. It is important for the industry to have available reliable, turnkey equipment from CEM vendors. Western Research Institute (WRI) is working closely with the Electric Power Research Institute (EPRI), the National Institute of Standards and Technology (NIST), and the Environmental Protection Agency (EPA) to facilitate the development of the experimental criteria for a NIST traceability protocol for dynamic elemental mercury vapor generators. The generators are used to calibrate mercury CEMs at power plant sites. The Clean Air Mercury Rule (CAMR) which was published in the Federal Register on May 18, 2005 requires that calibration be performed with NIST-traceable standards (Federal Register 2007). Traceability procedures will be defined by EPA. An initial draft traceability protocol was issued by EPA in May 2007 for comment. In August 2007, EPA issued an interim traceability protocol for elemental mercury generators (EPA 2007). The protocol is based on the actual analysis of the output of each calibration unit at several concentration levels ranging initially from about 2-40 {micro}g/m{sup 3} elemental mercury, and in the future down to 0.2 {micro}g/m{sup 3}, and this analysis will be directly traceable to analyses by NIST. The document is divided into two separate sections. The first deals with the qualification of generators by the vendors for use in mercury CEM calibration. The second describes the procedure that the vendors must use to certify the generator models that meet the qualification specifications. The NIST traceable certification is performance based, traceable to analysis using isotope dilution inductively coupled plasma/mass spectrometry performed by NIST in Gaithersburg, MD. The

  12. Na, Rb and Cs partitioning between metal, silicate and sulfide: Implications for volatile depletion in terrestrial planets

    Science.gov (United States)

    Boujibar, A.; Fei, Y.; Du, Z.; Righter, K.; Bullock, E. S.

    2017-12-01

    Inner Solar System materials are known for their depletion in volatile elements, including the moderately volatile alkalis: Na, K, Rb, and Cs. The origin of this depletion is still uncertain, as several processes could have been involved, during the nebular condensation or planetary accretion. Volatile depletion is commonly estimated through comparison of alkali concentrations relatively to those of chondrites, assuming they remain in planetary mantles during core segregation. However, experimental studies show that substantial K can partition into metals that are enriched in sulfur and oxygen. Several models have also suggested that sulfides may have played an important role during episodes of sulfide segregation from a crystallizing magma ocean (sulfide matte) or accretion of S-rich planetary embryos. For Mercury, a sulfide layer could be present between core and mantle, due to immiscibility between Si-rich and S-rich metals. Therefore, here we investigate whether alkali elements (Na, Cs and Rb) could be partly sequestered in planetary cores during their differentiation. We conducted experiments at high pressure and temperature (1 to 5 GPa and up to 1900 °C) to determine partition coefficients of Na, Rb and Cs between metal and silicate. Our results show that pressure, temperature, sulfur and oxygen in metals enhance the partitioning of Na, Rb and Cs into metals, as previously found for K. For all three investigated alkalis (Na, Rb and Cs), we found a maximum partition coefficient of 1 between sulfides containing 13 wt% O and silicate melt. Therefore, S-rich cores or sulfide layers formed due to immiscibility in Fe-S-O systems could have acted as important geochemical reservoirs for alkali elements. Using our experimental data and different assumptions on initial bulk abundances, we evaluate volatile depletion in terrestrial planets, by comparing resulting mantle alkali concentrations after core segregation, with actual concentrations in the Earth's mantle.

  13. Recent mercury contamination from artisanal gold mining on Buru Island, Indonesia – Potential future risks to environmental health and food safety

    International Nuclear Information System (INIS)

    Male, Yusthinus Thobias; Reichelt-Brushett, Amanda Jean; Pocock, Matt; Nanlohy, Albert

    2013-01-01

    Highlights: • Recent mercury contamination from artisanal gold mining, Buru Island, Indonesia. • Measured dispersal into the marine environment. • Implications for food safety. • Challenges for introducing mercury reduction strategies. -- Abstract: In November 2011 gold was found at Mount Botak, Buru Island, Mollucas Province, Indonesia. Since 2012 mercury has been used to extract the gold requiring large volumes of water and resulting in deposition of mercury into Wamsait River and Kayeli Bay. Total mercury in waste ponds was over 680 mg/kg. In sediments at the mouth of the local river and a small feeder creek >3.00 mg/kg and >7.66 mg/kg respectively. River and bay sediments were proportionately higher in available mercury than elemental mercury and more strongly bound mercuric sulfide compared to that in trommel waste. This preliminary investigation raises concerns about the long term distribution and speciation of mercury. The floodplain is an important agricultural resource, and Mollucas Province is recognised nationally as the centre for Indonesian fish stocks. Challenges for management include communicating the potential future risks to the community and leaders and identifying mechanisms to reduce mercury waste

  14. Direct lead isotope analysis in Hg-rich sulfides by LA-MC-ICP-MS with a gas exchange device and matrix-matched calibration

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wen [State Key Laboratory of Geological Processes and Mineral Resources, Faculty of Earth Sciences, China University of Geosciences, Wuhan, 430074 (China); Hu, Zhaochu, E-mail: zchu@vip.sina.com [State Key Laboratory of Geological Processes and Mineral Resources, Faculty of Earth Sciences, China University of Geosciences, Wuhan, 430074 (China); Günther, Detlef, E-mail: guenther@inorg.chem.ethz.ch [ETH Zurich, Laboratory for Inorganic Chemistry, CH-8093, Zurich (Switzerland); Liu, Yongsheng; Ling, Wenli; Zong, Keqing; Chen, Haihong; Gao, Shan [State Key Laboratory of Geological Processes and Mineral Resources, Faculty of Earth Sciences, China University of Geosciences, Wuhan, 430074 (China)

    2016-12-15

    In situ Pb isotope data of sulfide samples measured by LA-MC-ICP-MS provide valuable geochemical information for studies of the origin and evolution of ore deposits. However, the severe isobaric interference of {sup 204}Hg on {sup 204}Pb and the lack of matrix-matched sulfide reference materials limit the precision of Pb isotopic analyses for Hg-rich sulfides. In this study, we observe that Hg forms vapor and can be completely removed from sample aerosol particles produced by laser ablation using a gas exchange device. Additionally, this device does not influence the signal intensities of Pb isotopes. The within-run precision, the external reproducibility and the analytical accuracy are significantly improved for the Hg-rich sulfide samples using this mercury-vapor-removing device. Matrix effects are observed when using silicate glass reference materials as the external standards to assess the relationship of mass fractionation factors between Tl and Pb in sulfide samples, resulting in a maximum deviation of ∼0.20% for {sup 20x}Pb/{sup 204}Pb. Matrix-matched reference materials are therefore required for the highly precise and accurate Pb isotope analyses of sulfide samples. We investigated two sulfide samples, MASS-1 (the Unites States Geological Survey reference materials) and Sph-HYLM (a natural sphalerite), as potential candidates. Repeated analyses of the two proposed sulfide reference materials by LA-MC-ICP-MS yield good external reproducibility of <0.04% (RSD, k = 2) for {sup 20x}Pb/{sup 206}Pb and <0.06% (RSD, k = 2) for {sup 20x}Pb/{sup 204}Pb with the exception of {sup 20x}Pb/{sup 204}Pb in MASS-1, which provided an external reproducibility of 0.24% (RSD, k = 2). Because the concentration of Pb in MASS-1 (76 μg g{sup −1}) is ∼5.2 times lower than that in Sph-HYLM (394 ± 264 μg g{sup −1}). The in situ analytical results of MASS-1 and Sph-HYLM are consistent with the values obtained by solution MC-ICP-MS, demonstrating the reliability

  15. Method and apparatus for sampling atmospheric mercury

    Science.gov (United States)

    Trujillo, Patricio E.; Campbell, Evan E.; Eutsler, Bernard C.

    1976-01-20

    A method of simultaneously sampling particulate mercury, organic mercurial vapors, and metallic mercury vapor in the working and occupational environment and determining the amount of mercury derived from each such source in the sampled air. A known volume of air is passed through a sampling tube containing a filter for particulate mercury collection, a first adsorber for the selective adsorption of organic mercurial vapors, and a second adsorber for the adsorption of metallic mercury vapor. Carbon black molecular sieves are particularly useful as the selective adsorber for organic mercurial vapors. The amount of mercury adsorbed or collected in each section of the sampling tube is readily quantitatively determined by flameless atomic absorption spectrophotometry.

  16. Hydrogen sulfide can inhibit and enhance oxygenic photosynthesis in a cyanobacterium from sulfidic springs

    NARCIS (Netherlands)

    Klatt, Judith M.; Haas, Sebastian; Yilmaz, Pelin; de Beer, Dirk; Polerecky, Lubos

    We used microsensors to investigate the combinatory effect of hydrogen sulfide (H2S) and light on oxygenic photosynthesis in biofilms formed by a cyanobacterium from sulfidic springs. We found that photosynthesis was both positively and negatively affected by H2S: (i) H2S accelerated the recovery of

  17. Sulfide response analysis for sulfide control using a pS electrode in sulfate reducing bioreactors

    NARCIS (Netherlands)

    Villa Gomez, D.K.; Cassidy, J.; Keesman, K.J.; Sampaio, R.M.; Lens, P.N.L.

    2014-01-01

    Step changes in the organic loading rate (OLR) through variations in the influent chemical oxygen demand (CODin) concentration or in the hydraulic retention time (HRT) at constant COD/SO4 2- ratio (0.67) were applied to create sulfide responses for the design of a sulfide control in sulfate reducing

  18. Highly Reducing Partitioning Experiments Relevant to the Planet Mercury

    Science.gov (United States)

    Rowland, Rick, II; Vander Kaaden, Kathleen E.; McCubbin, Francis M.; Danielson, Lisa R.

    2017-01-01

    With the data returned from the MErcury Surface Space ENvironment GEochemistry and Ranging (MESSENGER) mission, there are now numerous constraints on the physical and chemical properties of Mercury, including its surface composition. The high S and low FeO contents observed from MESSENGER on the planet's surface suggests a low oxygen fugacity of the present planetary materials. Estimates of the oxygen fugacity for Mercurian magmas are approximately 3-7 log units below the Iron-Wüstite (Fe-FeO) oxygen buffer, several orders of magnitude more reducing than other terrestrial bodies we have data from such as the Earth, Moon, or Mars. Most of our understanding of elemental partitioning behavior comes from observations made on terrestrial rocks, but Mercury's oxygen fugacity is far outside the conditions of those samples. With limited oxygen available, lithophile elements may instead exhibit chalcophile, halophile, or siderophile behaviors. Furthermore, very few natural samples of rocks that formed under reducing conditions are available in our collections (e.g., enstatite chondrites, achondrites, aubrites). With this limited amount of material, we must perform experiments to determine the elemental partitioning behavior of typically lithophile elements as a function of decreasing oxygen fugacity. Experiments are being conducted at 4 GPa in an 880-ton multi-anvil press, at temperatures up to 1850degC. The composition of starting materials for the experiments were selected for the final run products to contain metal, silicate melt, and sulfide melt phases. Oxygen fugacity is controlled in the experiments by adding silicon metal to the samples, using the Si-SiO2 oxygen buffer, which is approximately 5 log units more reducing than the Fe-FeO oxygen buffer at our temperatures of interest. The target silicate melt compositional is diopside (CaMgSi2O6) because measured surface compositions indicate partial melting of a pyroxene-rich mantle. Elements detected on Mercury

  19. Pathways for Energization of Ca in Mercury's Exosphere

    Science.gov (United States)

    Killen, Rosemary M.

    2015-01-01

    We investigate the possible pathways to produce the extreme energy observed in the calcium exosphere of Mercury. Any mechanism must explain the facts that Ca in Mercury's exosphere is extremely hot, that it is seen almost exclusively on the dawnside of the planet, and that its content varies seasonally, not sporadically. Simple diatomic molecules or their clusters are considered, focusing on calcium oxides while acknowledging that Ca sulfides may also be the precursor molecules. We first discuss impact vaporization to justify the assumption that CaO and Ca-oxide clusters are expected from impacts on Mercury. Then we discuss processes by which the atomic Ca is energized to a 70,000 K gas. The processes considered are (1) electron-impact dissociation of CaO molecules, (2) spontaneous dissociation of Ca-bearing molecules following impact vaporization, (3) shock-induced dissociative ionization, (4) photodissociation and (5) sputtering. We conclude that electron-impact dissociation cannot produce the required abundance of Ca, and sputtering cannot reproduce the observed spatial and temporal variation that is measured. Spontaneous dissociation is unlikely to result in the high energy that is seen. Of the two remaining processes, shock induced dissociative ionization produces the required energy and comes close to producing the required abundance, but rates are highly dependent on the incoming velocity distribution of the impactors. Photodissociation probably can produce the required abundance of Ca, but simulations show that photodissociation cannot reproduce the observed spatial distribution.

  20. Mercury Information Clearinghouse

    Energy Technology Data Exchange (ETDEWEB)

    Chad A. Wocken; Michael J. Holmes; Dennis L. Laudal; Debra F. Pflughoeft-Hassett; Greg F. Weber; Nicholas V. C. Ralston; Stanley J. Miller; Grant E. Dunham; Edwin S. Olson; Laura J. Raymond; John H. Pavlish; Everett A. Sondreal; Steven A. Benson

    2006-03-31

    The Canadian Electricity Association (CEA) identified a need and contracted the Energy & Environmental Research Center (EERC) to create and maintain an information clearinghouse on global research and development activities related to mercury emissions from coal-fired electric utilities. With the support of CEA, the Center for Air Toxic Metals{reg_sign} (CATM{reg_sign}) Affiliates, and the U.S. Department of Energy (DOE), the EERC developed comprehensive quarterly information updates that provide a detailed assessment of developments in the various areas of mercury monitoring, control, policy, and research. A total of eight topical reports were completed and are summarized and updated in this final CEA quarterly report. The original quarterly reports can be viewed at the CEA Web site (www.ceamercuryprogram.ca). In addition to a comprehensive update of previous mercury-related topics, a review of results from the CEA Mercury Program is provided. Members of Canada's coal-fired electricity generation sector (ATCO Power, EPCOR, Manitoba Hydro, New Brunswick Power, Nova Scotia Power Inc., Ontario Power Generation, SaskPower, and TransAlta) and CEA, have compiled an extensive database of information from stack-, coal-, and ash-sampling activities. Data from this effort are also available at the CEA Web site and have provided critical information for establishing and reviewing a mercury standard for Canada that is protective of environment and public health and is cost-effective. Specific goals outlined for the CEA mercury program included the following: (1) Improve emission inventories and develop management options through an intensive 2-year coal-, ash-, and stack-sampling program; (2) Promote effective stack testing through the development of guidance material and the support of on-site training on the Ontario Hydro method for employees, government representatives, and contractors on an as-needed basis; (3) Strengthen laboratory analytical capabilities through

  1. Transient Kinetic Analysis of Hydrogen Sulfide Oxidation Catalyzed by Human Sulfide Quinone Oxidoreductase*

    Science.gov (United States)

    Mishanina, Tatiana V.; Yadav, Pramod K.; Ballou, David P.; Banerjee, Ruma

    2015-01-01

    The first step in the mitochondrial sulfide oxidation pathway is catalyzed by sulfide quinone oxidoreductase (SQR), which belongs to the family of flavoprotein disulfide oxidoreductases. During the catalytic cycle, the flavin cofactor is intermittently reduced by sulfide and oxidized by ubiquinone, linking H2S oxidation to the electron transfer chain and to energy metabolism. Human SQR can use multiple thiophilic acceptors, including sulfide, sulfite, and glutathione, to form as products, hydrodisulfide, thiosulfate, and glutathione persulfide, respectively. In this study, we have used transient kinetics to examine the mechanism of the flavin reductive half-reaction and have determined the redox potential of the bound flavin to be −123 ± 7 mV. We observe formation of an unusually intense charge-transfer (CT) complex when the enzyme is exposed to sulfide and unexpectedly, when it is exposed to sulfite. In the canonical reaction, sulfide serves as the sulfur donor and sulfite serves as the acceptor, forming thiosulfate. We show that thiosulfate is also formed when sulfide is added to the sulfite-induced CT intermediate, representing a new mechanism for thiosulfate formation. The CT complex is formed at a kinetically competent rate by reaction with sulfide but not with sulfite. Our study indicates that sulfide addition to the active site disulfide is preferred under normal turnover conditions. However, under pathological conditions when sulfite concentrations are high, sulfite could compete with sulfide for addition to the active site disulfide, leading to attenuation of SQR activity and to an alternate route for thiosulfate formation. PMID:26318450

  2. Transient Kinetic Analysis of Hydrogen Sulfide Oxidation Catalyzed by Human Sulfide Quinone Oxidoreductase.

    Science.gov (United States)

    Mishanina, Tatiana V; Yadav, Pramod K; Ballou, David P; Banerjee, Ruma

    2015-10-09

    The first step in the mitochondrial sulfide oxidation pathway is catalyzed by sulfide quinone oxidoreductase (SQR), which belongs to the family of flavoprotein disulfide oxidoreductases. During the catalytic cycle, the flavin cofactor is intermittently reduced by sulfide and oxidized by ubiquinone, linking H2S oxidation to the electron transfer chain and to energy metabolism. Human SQR can use multiple thiophilic acceptors, including sulfide, sulfite, and glutathione, to form as products, hydrodisulfide, thiosulfate, and glutathione persulfide, respectively. In this study, we have used transient kinetics to examine the mechanism of the flavin reductive half-reaction and have determined the redox potential of the bound flavin to be -123 ± 7 mV. We observe formation of an unusually intense charge-transfer (CT) complex when the enzyme is exposed to sulfide and unexpectedly, when it is exposed to sulfite. In the canonical reaction, sulfide serves as the sulfur donor and sulfite serves as the acceptor, forming thiosulfate. We show that thiosulfate is also formed when sulfide is added to the sulfite-induced CT intermediate, representing a new mechanism for thiosulfate formation. The CT complex is formed at a kinetically competent rate by reaction with sulfide but not with sulfite. Our study indicates that sulfide addition to the active site disulfide is preferred under normal turnover conditions. However, under pathological conditions when sulfite concentrations are high, sulfite could compete with sulfide for addition to the active site disulfide, leading to attenuation of SQR activity and to an alternate route for thiosulfate formation. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  3. Experimental simulations of sulfide formation in the solar nebula.

    Science.gov (United States)

    Lauretta, D S; Lodders, K; Fegley, B

    1997-07-18

    Sulfurization of meteoritic metal in H2S-H2 gas produced three different sulfides: monosulfide solid solution [(Fe,Ni)1-xS], pentlandite [(Fe,Ni)9-xS8], and a phosphorus-rich sulfide. The composition of the remnant metal was unchanged. These results are contrary to theoretical predictions that sulfide formation in the solar nebula produced troilite (FeS) and enriched the remaining metal in nickel. The experimental sulfides are chemically and morphologically similar to sulfide grains in the matrix of the Alais (class CI) carbonaceous chondrite, suggesting that these meteoritic sulfides may be condensates from the solar nebula.

  4. Mercury Phase II Study - Mercury Behavior in Salt Processing Flowsheet

    International Nuclear Information System (INIS)

    Jain, V.; Shah, H.; Wilmarth, W. R.

    2016-01-01

    Mercury (Hg) in the Savannah River Site Liquid Waste System (LWS) originated from decades of canyon processing where it was used as a catalyst for dissolving the aluminum cladding of reactor fuel. Approximately 60 metric tons of mercury is currently present throughout the LWS. Mercury has long been a consideration in the LWS, from both hazard and processing perspectives. In February 2015, a Mercury Program Team was established at the request of the Department of Energy to develop a comprehensive action plan for long-term management and removal of mercury. Evaluation was focused in two Phases. Phase I activities assessed the Liquid Waste inventory and chemical processing behavior using a system-by-system review methodology, and determined the speciation of the different mercury forms (Hg+, Hg++, elemental Hg, organomercury, and soluble versus insoluble mercury) within the LWS. Phase II activities are building on the Phase I activities, and results of the LWS flowsheet evaluations will be summarized in three reports: Mercury Behavior in the Salt Processing Flowsheet (i.e. this report); Mercury Behavior in the Defense Waste Processing Facility (DWPF) Flowsheet; and Mercury behavior in the Tank Farm Flowsheet (Evaporator Operations). The evaluation of the mercury behavior in the salt processing flowsheet indicates, inter alia, the following: (1) In the assembled Salt Batches 7, 8 and 9 in Tank 21, the total mercury is mostly soluble with methylmercury (MHg) contributing over 50% of the total mercury. Based on the analyses of samples from 2H Evaporator feed and drop tanks (Tanks 38/43), the source of MHg in Salt Batches 7, 8 and 9 can be attributed to the 2H evaporator concentrate used in assembling the salt batches. The 2H Evaporator is used to evaporate DWPF recycle water. (2) Comparison of data between Tank 21/49, Salt Solution Feed Tank (SSFT), Decontaminated Salt Solution Hold Tank (DSSHT), and Tank 50 samples suggests that the total mercury as well as speciated

  5. A mercury transport and fate model (LM2-mercury) for mass budget assessment of mercury cycling in Lake Michigan

    Science.gov (United States)

    LM2-Mercury, a mercury mass balance model, was developed to simulate and evaluate the transport, fate, and biogeochemical transformations of mercury in Lake Michigan. The model simulates total suspended solids (TSS), disolved organic carbon (DOC), and total, elemental, divalent, ...

  6. Mercury stabilization in chemically bonded phosphate ceramics

    International Nuclear Information System (INIS)

    Wagh, A. S.; Singh, D.; Jeong, S. Y.

    2000-01-01

    Mercury stabilization and solidification is a significant challenge for conventional stabilization technologies. This is because of the stringent regulatory limits on leaching of its stabilized products. In a conventional cement stabilization process, Hg is converted at high pH to its hydroxide, which is not a very insoluble compound; hence the preferred route for Hg sulfidation to convert it into insoluble cinnabar (HgS). Unfortunately, efficient formation of this compound is pH-dependent. At a high pH, one obtains a more soluble Hg sulfate, in a very low pH range, insufficient immobilization occurs because of the escape of hydrogen sulfide, while efficient formation of HgS occurs only in a moderately acidic region. Thus, the pH range of 4 to 8 is where stabilization with Chemically Bonded Phosphate Ceramics (CBPC) is carried out. This paper discusses the authors experience on bench-scale stabilization of various US Department of Energy (DOE) waste streams containing Hg in the CBPC process. This process was developed to treat DOE's mixed waste streams. It is a room-temperature-setting process based on an acid-base reaction between magnesium oxide and monopotassium phosphate solution that forms a dense ceramic within hours. For Hg stabilization, addition of a small amount ( 2 S or K 2 S is sufficient in the binder composition. Here the Toxicity Characteristic Leaching Procedure (TCLP) results on CBPC waste forms of surrogate waste streams representing secondary Hg containing wastes such as combustion residues and Delphi DETOXtrademark residues are presented. The results show that although the current limit on leaching of Hg is 0.2 mg/L, the results from the CBPC waste forms are at least one order lower than this stringent limit. Encouraged by these results on surrogate wastes, they treated actual low-level Hg-containing mixed waste from their facility at Idaho. TCLP results on this waste are presented here. The efficient stabilization in all these cases is

  7. Mercury Exposure and Heart Diseases

    Science.gov (United States)

    Genchi, Giuseppe; Sinicropi, Maria Stefania; Carocci, Alessia; Lauria, Graziantonio; Catalano, Alessia

    2017-01-01

    Environmental contamination has exposed humans to various metal agents, including mercury. It has been determined that mercury is not only harmful to the health of vulnerable populations such as pregnant women and children, but is also toxic to ordinary adults in various ways. For many years, mercury was used in a wide variety of human activities. Nowadays, the exposure to this metal from both natural and artificial sources is significantly increasing. Recent studies suggest that chronic exposure, even to low concentration levels of mercury, can cause cardiovascular, reproductive, and developmental toxicity, neurotoxicity, nephrotoxicity, immunotoxicity, and carcinogenicity. Possible biological effects of mercury, including the relationship between mercury toxicity and diseases of the cardiovascular system, such as hypertension, coronary heart disease, and myocardial infarction, are being studied. As heart rhythm and function are under autonomic nervous system control, it has been hypothesized that the neurotoxic effects of mercury might also impact cardiac autonomic function. Mercury exposure could have a long-lasting effect on cardiac parasympathetic activity and some evidence has shown that mercury exposure might affect heart rate variability, particularly early exposures in children. The mechanism by which mercury produces toxic effects on the cardiovascular system is not fully elucidated, but this mechanism is believed to involve an increase in oxidative stress. The exposure to mercury increases the production of free radicals, potentially because of the role of mercury in the Fenton reaction and a reduction in the activity of antioxidant enzymes, such as glutathione peroxidase. In this review we report an overview on the toxicity of mercury and focus our attention on the toxic effects on the cardiovascular system. PMID:28085104

  8. Mercury Exposure and Heart Diseases.

    Science.gov (United States)

    Genchi, Giuseppe; Sinicropi, Maria Stefania; Carocci, Alessia; Lauria, Graziantonio; Catalano, Alessia

    2017-01-12

    Environmental contamination has exposed humans to various metal agents, including mercury. It has been determined that mercury is not only harmful to the health of vulnerable populations such as pregnant women and children, but is also toxic to ordinary adults in various ways. For many years, mercury was used in a wide variety of human activities. Nowadays, the exposure to this metal from both natural and artificial sources is significantly increasing. Recent studies suggest that chronic exposure, even to low concentration levels of mercury, can cause cardiovascular, reproductive, and developmental toxicity, neurotoxicity, nephrotoxicity, immunotoxicity, and carcinogenicity. Possible biological effects of mercury, including the relationship between mercury toxicity and diseases of the cardiovascular system, such as hypertension, coronary heart disease, and myocardial infarction, are being studied. As heart rhythm and function are under autonomic nervous system control, it has been hypothesized that the neurotoxic effects of mercury might also impact cardiac autonomic function. Mercury exposure could have a long-lasting effect on cardiac parasympathetic activity and some evidence has shown that mercury exposure might affect heart rate variability, particularly early exposures in children. The mechanism by which mercury produces toxic effects on the cardiovascular system is not fully elucidated, but this mechanism is believed to involve an increase in oxidative stress. The exposure to mercury increases the production of free radicals, potentially because of the role of mercury in the Fenton reaction and a reduction in the activity of antioxidant enzymes, such as glutathione peroxidase. In this review we report an overview on the toxicity of mercury and focus our attention on the toxic effects on the cardiovascular system.

  9. Mercury Exposure and Heart Diseases

    Directory of Open Access Journals (Sweden)

    Giuseppe Genchi

    2017-01-01

    Full Text Available Environmental contamination has exposed humans to various metal agents, including mercury. It has been determined that mercury is not only harmful to the health of vulnerable populations such as pregnant women and children, but is also toxic to ordinary adults in various ways. For many years, mercury was used in a wide variety of human activities. Nowadays, the exposure to this metal from both natural and artificial sources is significantly increasing. Recent studies suggest that chronic exposure, even to low concentration levels of mercury, can cause cardiovascular, reproductive, and developmental toxicity, neurotoxicity, nephrotoxicity, immunotoxicity, and carcinogenicity. Possible biological effects of mercury, including the relationship between mercury toxicity and diseases of the cardiovascular system, such as hypertension, coronary heart disease, and myocardial infarction, are being studied. As heart rhythm and function are under autonomic nervous system control, it has been hypothesized that the neurotoxic effects of mercury might also impact cardiac autonomic function. Mercury exposure could have a long-lasting effect on cardiac parasympathetic activity and some evidence has shown that mercury exposure might affect heart rate variability, particularly early exposures in children. The mechanism by which mercury produces toxic effects on the cardiovascular system is not fully elucidated, but this mechanism is believed to involve an increase in oxidative stress. The exposure to mercury increases the production of free radicals, potentially because of the role of mercury in the Fenton reaction and a reduction in the activity of antioxidant enzymes, such as glutathione peroxidase. In this review we report an overview on the toxicity of mercury and focus our attention on the toxic effects on the cardiovascular system.

  10. MERCURY USAGE AND ALTERNATIVES IN THE ELECTRICAL AND ELECTRONICS INDUSTRIES

    Science.gov (United States)

    Many industries have already found alternatives for mercury or have greatly decreased mercury use. However, the unique electromechanical and photoelectric properties of mercury and mercury compounds have made replacement of mercury difficult in some applications. This study was i...

  11. Sulfide Precipitation in Wastewater at Short Timescales

    DEFF Research Database (Denmark)

    Kiilerich, Bruno; van de Ven, Wilbert; Nielsen, Asbjørn Haaning

    2017-01-01

    Abatement of sulfides in sewer systems using iron salts is a widely used strategy. When dosing at the end of a pumping main, the reaction kinetics of sulfide precipitation becomes important. Traditionally the reaction has been assumed to be rapid or even instantaneous. This work shows that this i......Abatement of sulfides in sewer systems using iron salts is a widely used strategy. When dosing at the end of a pumping main, the reaction kinetics of sulfide precipitation becomes important. Traditionally the reaction has been assumed to be rapid or even instantaneous. This work shows...... that this is not the case for sulfide precipitation by ferric iron. Instead, the reaction time was found to be on a timescale where it must be considered when performing end-of-pipe treatment. For real wastewaters at pH 7, a stoichiometric ratio around 14 mol Fe(II) (mol S(−II))−1 was obtained after 1.5 s, while the ratio...

  12. Mercury's exosphere: observations during MESSENGER's First Mercury flyby.

    Science.gov (United States)

    McClintock, William E; Bradley, E Todd; Vervack, Ronald J; Killen, Rosemary M; Sprague, Ann L; Izenberg, Noam R; Solomon, Sean C

    2008-07-04

    During MESSENGER's first Mercury flyby, the Mercury Atmospheric and Surface Composition Spectrometer measured Mercury's exospheric emissions, including those from the antisunward sodium tail, calcium and sodium close to the planet, and hydrogen at high altitudes on the dayside. Spatial variations indicate that multiple source and loss processes generate and maintain the exosphere. Energetic processes connected to the solar wind and magnetospheric interaction with the planet likely played an important role in determining the distributions of exospheric species during the flyby.

  13. Recovery of mercury from acid waste residues

    Science.gov (United States)

    Greenhalgh, Wilbur O.

    1989-12-05

    Mercury can be recovered from nitric acid-containing fluids by reacting the fluid with aluminum metal to produce mercury metal, and then quenching the reactivity of the nitric acid prior to nitration of the mercury metal.

  14. Health Effects of Exposures to Mercury

    Science.gov (United States)

    ... IRIS database Top of Page Elemental (Metallic) Mercury Effects Exposures to metallic mercury most often occur when metallic ... poor performance on tests of mental function Higher exposures may also cause kidney effects, respiratory failure and death. Note that metallic mercury ...

  15. Mercury Poisoning Linked to Skin Products

    Science.gov (United States)

    ... Products For Consumers Home For Consumers Consumer Updates Mercury Poisoning Linked to Skin Products Share Tweet Linkedin ... and, in some situations, criminal prosecution. Dangers of Mercury Exposure to mercury can have serious health consequences. ...

  16. Functional consortium for denitrifying sulfide removal process.

    Science.gov (United States)

    Chen, Chuan; Ren, Nanqi; Wang, Aijie; Liu, Lihong; Lee, Duu-Jong

    2010-03-01

    Denitrifying sulfide removal (DSR) process simultaneously converts sulfide, nitrate, and chemical oxygen demand from industrial wastewaters to elemental sulfur, nitrogen gas, and carbon dioxide, respectively. This investigation utilizes a dilution-to-extinction approach at 10(-2) to 10(-6) dilutions to elucidate the correlation between the composition of the microbial community and the DSR performance. In the original suspension and in 10(-2) dilution, the strains Stenotrophomonas sp., Thauera sp., and Azoarcus sp. are the heterotrophic denitrifiers and the strains Paracoccus sp. and Pseudomonas sp. are the sulfide-oxidizing denitrifers. The 10(-4) dilution is identified as the functional consortium for the present DSR system, which comprises two functional strains, Stenotrophomonas sp. strain Paracoccus sp. At 10(-6) dilution, all DSR performance was lost. The functions of the constituent cells in the DSR granules were discussed based on data obtained using the dilution-to-extinction approach.

  17. Acute inhalation toxicity of carbonyl sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Benson, J.M.; Hahn, F.F.; Barr, E.B. [and others

    1995-12-01

    Carbonyl sulfide (COS), a colorless gas, is a side product of industrial procedures sure as coal hydrogenation and gasification. It is structurally related to and is a metabolite of carbon disulfide. COS is metabolized in the body by carbonic anhydrase to hydrogen sulfide (H{sub 2}S), which is thought to be responsible for COS toxicity. No threshold limit value for COS has been established. Results of these studies indicate COS (with an LC{sub 50} of 590 ppm) is slightly less acutely toxic than H{sub 2}S (LC{sub 50} of 440 ppm).

  18. Girdler-sulfide process physical properties

    International Nuclear Information System (INIS)

    Neuburg, H.J.; Atherley, J.F.; Walker, L.G.

    1977-05-01

    Physical properties of pure hydrogen sulfide and of gaseous and liquid solutions of the H 2 S-H 2 O system have been formulated. Tables for forty-nine different properties in the pressure and temperature range of interest to the Girdler-Sulfide (GS) process for heavy water production are given. All properties are presented in SI units. A computer program capable of calculating properties of the pure components as well as gaseous mixtures and liquid solutions at saturated and non-saturated conditions is included. (author)

  19. Interior Volatile Reservoirs in Mercury

    Science.gov (United States)

    Anzures, B. A.; Parman, S. W.; Milliken, R. E.; Head, J. W.

    2018-05-01

    More measurements of 1) surface volatiles, and 2) pyroclastic deposits paired with experimental volatile analyses in silicate minerals can constrain conditions of melting and subsequent eruption on Mercury.

  20. Mercury in Canadian crude oil

    International Nuclear Information System (INIS)

    Hollebone, B.P.

    2005-01-01

    Estimates for average mercury concentrations in crude oil range widely from 10 ng/g of oil to 3,500 ng/g of oil. With such a broad range of estimates, it is difficult to determine the contributions of the petroleum sector to the total budget of mercury emissions. In response to concerns that the combustion of petroleum products may be a major source of air-borne mercury pollution, Environment Canada and the Canadian Petroleum Products Institute has undertaken a survey of the average total mercury concentration in crude oil processed in Canadian refineries. In order to calculate the potential upper limit of total mercury in all refined products, samples of more than 30 different types of crude oil collected from refineries were measured for their concentration of mercury as it enters into a refinery before processing. High temperature combustion, cold vapour atomic absorption and cold vapour atomic fluorescence were the techniques used to quantify mercury in the samples. The results of the study provide information on the total mass of mercury present in crude oil processed in Canada each year. Results can be used to determine the impact of vehicle exhaust emissions to the overall Canadian mercury emission budget. 17 refs., 2 tabs., 2 figs

  1. Mercury in bryophytes (moss)

    Energy Technology Data Exchange (ETDEWEB)

    Yeaple, D S

    1972-01-28

    Recent reports in the literature, concerning the ability of certain mosses and lichens to concentrate heavy metals, have led to an investigation of the potential application of mosses as indicators of the transport of mercury through the atmosphere. A number of moss samples were collected to provide information regarding the level of mercury in moss around several types of populated areas. The results reported are from moss collected within an 80 mile radius of Boston, Massachusetts, along the Maine coast, near the tops of Mount Katahdin in Maine and Mount Washington in New Hampshire, and from Walden, New York, a small town located about 60 miles north of New York City. The data are admittedly limited, but provide sufficient insight into the usefulness of moss as an indicator to warrant the pursuit of a more detailed investigation. 6 references, 1 table.

  2. Integrated criteria document mercury

    International Nuclear Information System (INIS)

    Sloof, W.; Beelan, P. van; Annema, J.A.; Janus, J.A.

    1995-01-01

    The document contains a systematic review and a critical evaluation of the most relevant data on the priority substance mercury for the purpose of effect-oriented environmental policy. Chapter headings are: properties and existing standards; production, application, sources and emissions (natural sources, industry, energy, households, agriculture, dental use, waste); distribution and transformation (cinnabar; Hg 2+ , Hg 2 2+ , elemental mercury, methylmercury, behavior in soil, water, air, biota); concentrations and fluxes in the environment and exposure levels (sampling and measuring methods, occurrence in soil, water, air etc.); effects (toxicity to humans and aquatic and terrestrial systems); emissions reduction (from industrial sources, energy, waste processing etc.); and evaluation (risks, standards, emission reduction objectives, measuring strategies). 395 refs

  3. Method for mercury refinement

    Science.gov (United States)

    Grossman, M.W.; Speer, R.; George, W.A.

    1991-04-09

    The effluent from mercury collected during the photochemical separation of the [sup 196]Hg isotope is often contaminated with particulate mercurous chloride, Hg[sub 2]Cl[sub 2]. The use of mechanical filtering via thin glass tubes, ultrasonic rinsing with acetone (dimethyl ketone) and a specially designed cold trap have been found effective in removing the particulate (i.e., solid) Hg[sub 2]Cl[sub 2] contaminant. The present invention is particularly directed to such filtering. 5 figures.

  4. Apparatus for mercury refinement

    Science.gov (United States)

    Grossman, M.W.; Speer, R.; George, W.A.

    1991-07-16

    The effluent from mercury collected during the photochemical separation of the [sup 196]Hg isotope is often contaminated with particulate mercurous chloride, Hg[sub 2]Cl[sub 2]. The use of mechanical filtering via thin glass tubes, ultrasonic rinsing with acetone (dimethyl ketone) and a specially designed cold trap have been found effective in removing the particulate (i.e., solid) Hg[sub 2]Cl[sub 2] contaminant. The present invention is particularly directed to such filtering. 5 figures.

  5. The planet Mercury (1971)

    Science.gov (United States)

    1972-01-01

    The physical properties of the planet Mercury, its surface, and atmosphere are presented for space vehicle design criteria. The mass, dimensions, mean density, and orbital and rotational motions are described. The gravity field, magnetic field, electromagnetic radiation, and charged particles in the planet's orbit are discussed. Atmospheric pressure, temperature, and composition data are given along with the surface composition, soil mechanical properties, and topography, and the surface electromagnetic and temperature properties.

  6. Magnetic field of Mercury

    International Nuclear Information System (INIS)

    Jackson, D.J.; Beard, D.B.

    1977-01-01

    The geomagnetic field, suitably scaled down and parameterized, is shown to give a very good fit to the magnetic field measurements taken on the first and third passes of the Mariner 10 space probe past Mercury. The excellence of the fit to a reliable planetary magnetospheric model is good evidence that the Mercury magnetosphere is formed by a simple, permanent, intrinsic planetary magnetic field distorted by the effects of the solar wind. The parameters used for a best fit to all the data are (depending slightly on the choice of data) 2.44--2.55 for the ratio of Mercury's magnetic field strength at the subsolar point to that of the earth's subsolar point field (this results in a dipole moment of 170 γR/sub M/ 3 (R/sub M/ is Mercury Radius), i.e., 2.41 x 10 22 G cm 3 in the same direction as the earth's dipole), approx.-113 γR/sub M/ 4 for the planetary quadrupole moment parallel to the dipole moment, 10degree--17degree for the tilt of the planet dipole toward the sun, 4.5degree for the tilt of the dipole toward dawn, and 2.5degree--7.6degree aberration angle for the shift in the tail axis from the planet-sun direction because of the planet's orbital velocity. The rms deviation overall for the entire data set compared with the theoretical fitted model for the magnetic field strength was 17 γ (approx.4% of the maximum field measured). If the data from the first pass that show presumed strong time variations are excluded, the overall rms deviation for the field magnitude is only 10 γ

  7. Method for scavenging mercury

    Science.gov (United States)

    Chang, Shih-ger [El Cerrito, CA; Liu, Shou-heng [Kaohsiung, TW; Liu, Zhao-rong [Beijing, CN; Yan, Naiqiang [Berkeley, CA

    2009-01-20

    Disclosed herein is a method for removing mercury from a gas stream comprising contacting the gas stream with a getter composition comprising bromine, bromochloride, sulphur bromide, sulphur dichloride or sulphur monochloride and mixtures thereof. In one preferred embodiment the getter composition is adsorbed onto a sorbent. The sorbent may be selected from the group consisting of flyash, limestone, lime, calcium sulphate, calcium sulfite, activated carbon, charcoal, silicate, alumina and mixtures thereof. Preferred is flyash, activated carbon and silica.

  8. Apparatus for mercury refinement

    International Nuclear Information System (INIS)

    Grossman, M.W.; Speer, R.; George, W.A.

    1991-01-01

    The effluent from mercury collected during the photochemical separation of the 196 Hg isotope is often contaminated with particulate mercurous chloride, Hg 2 Cl 2 . The use of mechanical filtering via thin glass tubes, ultrasonic rinsing with acetone (dimethyl ketone) and a specially designed cold trap have been found effective in removing the particulate (i.e., solid) Hg 2 Cl 2 contaminant. The present invention is particularly directed to such filtering. 5 figures

  9. Method for mercury refinement

    International Nuclear Information System (INIS)

    Grossman, M.W.; Speer, R.; George, W.A.

    1991-01-01

    The effluent from mercury collected during the photochemical separation of the 196 Hg isotope is often contaminated with particulate mercurous chloride, Hg 2 Cl 2 . The use of mechanical filtering via thin glass tubes, ultrasonic rinsing with acetone (dimethyl ketone) and a specially designed cold trap have been found effective in removing the particulate (i.e., solid) Hg 2 Cl 2 contaminant. The present invention is particularly directed to such filtering. 5 figures

  10. Use of biogenic sulfide for ZnS precipitation

    NARCIS (Netherlands)

    Esposito, G.; Veeken, A.; Weijma, J.; Lens, P.N.L.

    2006-01-01

    A 600 ml continuously stirred tank reactor was used to assess the performance of a zinc sulfide precipitation process using a biogenic sulfide solution (the effluent of a sulfate-reducing bioreactor) as sulfide source. In all experiments, a proportional-integral (PI) control algorithm was used to

  11. Mercury's Densely Cratered Surface

    Science.gov (United States)

    1974-01-01

    Mariner 10 took this picture (FDS 27465) of the densely cratered surface of Mercury when the spacecraft was 18,200 kilometers (8085 miles) from the planet on March 29. The dark line across top of picture is a 'dropout' of a few TV lines of data. At lower left, a portion of a 61 kilometer (38 mile) crater shows a flow front extending across the crater floor and filling more than half of the crater. The smaller, fresh crater at center is about 25 kilometers (15 miles) in diameter. Craters as small as one kilometer (about one-half mile) across are visible in the picture.The Mariner 10 mission, managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, explored Venus in February 1974 on the way to three encounters with Mercury-in March and September 1974 and in March 1975. The spacecraft took more than 7,000 photos of Mercury, Venus, the Earth and the Moon.Image Credit: NASA/JPL/Northwestern University

  12. Mercury removal sorbents

    Science.gov (United States)

    Alptekin, Gokhan

    2016-03-29

    Sorbents and methods of using them for removing mercury from flue gases over a wide range of temperatures are disclosed. Sorbent materials of this invention comprise oxy- or hydroxyl-halogen (chlorides and bromides) of manganese, copper and calcium as the active phase for Hg.sup.0 oxidation, and are dispersed on a high surface porous supports. In addition to the powder activated carbons (PACs), this support material can be comprised of commercial ceramic supports such as silica (SiO.sub.2), alumina (Al.sub.2O.sub.3), zeolites and clays. The support material may also comprise of oxides of various metals such as iron, manganese, and calcium. The non-carbon sorbents of the invention can be easily injected into the flue gas and recovered in the Particulate Control Device (PCD) along with the fly ash without altering the properties of the by-product fly ash enabling its use as a cement additive. Sorbent materials of this invention effectively remove both elemental and oxidized forms of mercury from flue gases and can be used at elevated temperatures. The sorbent combines an oxidation catalyst and a sorbent in the same particle to both oxidize the mercury and then immobilize it.

  13. Sediment-water interactions affecting dissolved-mercury distributions in Camp Far West Reservoir, California

    Science.gov (United States)

    Kuwabara, James S.; Alpers, Charles N.; Marvin-DiPasquale, Mark; Topping, Brent R.; Carter, James L.; Stewart, A. Robin; Fend, Steven V.; Parcheso, Francis; Moon, Gerald E.; Krabbenhoft, David P.

    2003-01-01

    Field and laboratory studies were conducted in April and November 2002 to provide the first direct measurements of the benthic flux of dissolved (0.2-micrometer filtered) mercury species (total and methylated forms) between the bottom sediment and water column at three sampling locations within Camp Far West Reservoir, California: one near the Bear River inlet to the reservoir, a second at a mid-reservoir site of comparable depth to the inlet site, and the third at the deepest position in the reservoir near the dam (herein referred to as the inlet, midreservoir and near-dam sites, respectively; Background, Fig. 1). Because of interest in the effects of historic hydraulic mining and ore processing in the Sierra Nevada foothills just upstream of the reservoir, dissolved-mercury species and predominant ligands that often control the mercury speciation (represented by dissolved organic carbon, and sulfides) were the solutes of primary interest. Benthic flux, sometimes referred to as internal recycling, represents the transport of dissolved chemical species between the water column and the underlying sediment. Because of the affinity of mercury to adsorb onto particle surfaces and to form insoluble precipitates (particularly with sulfides), the mass transport of mercury in mining-affected watersheds is typically particle dominated. As these enriched particles accumulate at depositional sites such as reservoirs, benthic processes facilitate the repartitioning, transformation, and transport of mercury in dissolved, biologically reactive forms (dissolved methylmercury being the most bioavailable for trophic transfer). These are the forms of mercury examined in this study. In contrast to typical scientific manuscripts, this report is formatted in a pyramid-like structure to serve the needs of diverse groups who may be interested in reviewing or acquiring information at various levels of technical detail (Appendix 1). The report enables quick transitions between the initial

  14. Possibilities of mercury removal in the dry flue gas cleaning lines of solid waste incineration units.

    Science.gov (United States)

    Svoboda, Karel; Hartman, Miloslav; Šyc, Michal; Pohořelý, Michael; Kameníková, Petra; Jeremiáš, Michal; Durda, Tomáš

    2016-01-15

    Dry methods of the flue gas cleaning (for HCl and SO2 removal) are useful particularly in smaller solid waste incineration units. The amount and forms of mercury emissions depend on waste (fuel) composition, content of mercury and chlorine and on the entire process of the flue gas cleaning. In the case of high HCl/total Hg molar ratio in the flue gas, the majority (usually 70-90%) of mercury is present in the form of HgCl2 and a smaller amount in the form of mercury vapors at higher temperatures. Removal of both main forms of mercury from the flue gas is dependent on chemical reactions and sorption processes at the temperatures below approx. 340 °C. Significant part of HgCl2 and a small part of elemental Hg vapors can be adsorbed on fly ash and solid particle in the air pollution control (APC) processes, which are removed in dust filters. Injection of non-impregnated active carbon (AC) or activated lignite coke particles is able to remove mainly the oxidized Hg(2+) compounds. Vapors of metallic Hg(o) are adsorbed relatively weakly. Much better chemisorption of Hg(o) together with higher sorbent capacity is achieved by AC-based sorbents impregnated with sulfur, alkali poly-sulfides, ferric chloride, etc. Inorganic sorbents with the same or similar chemical impregnation are also applicable for deeper Hg(o) removal (over 85%). SCR catalysts convert part of Hg(o) into oxidized compounds (HgO, HgCl2, etc.) contributing to more efficient Hg removal, but excess of NH3 has a negative effect. Both forms, elemental Hg(o) and HgCl2, can be converted into HgS particles by reacting with droplets/aerosol of poly-sulfides solutions/solids in flue gas. Mercury captured in the form of water insoluble HgS is more advantageous in the disposal of solid waste from APC processes. Four selected options of the dry flue gas cleaning with mercury removal are analyzed, assessed and compared (in terms of efficiency of Hg-emission reduction and costs) with wet methods and retrofits for more

  15. Modeling Sulfides, pH and Hydrogen Sulfide Gas in the Sewers of San Francisco

    DEFF Research Database (Denmark)

    Vollertsen, Jes; Revilla, Nohemy; Hvitved-Jacobsen, Thorkild

    2015-01-01

    An extensive measuring campaign targeted on sewer odor problems was undertaken in San Francisco. It was assessed whether a conceptual sewer process model could reproduce the measured concentrations of total sulfide in the wastewater and H2S gas in the sewer atmosphere, and to which degree...... such simulations have potential for further improving odor and sulfide management. The campaign covered measurement of wastewater sulfide by grab sampling and diurnal sampling, and H2S gas in the sewer atmosphere was logged. The tested model was based on the Wastewater Aerobic/Anaerobic Transformations in Sewers...... (WATS) sewer process concept, which never had been calibrated to such an extensive dataset. The study showed that the model was capable of reproducing the general levels of wastewater sulfide, wastewater pH, and sewer H2S gas. It could also reproduce the general variability of these parameters, albeit...

  16. Reaction between Hydrogen Sulfide and Limestone Calcines

    Czech Academy of Sciences Publication Activity Database

    Hartman, Miloslav; Svoboda, Karel; Trnka, Otakar; Čermák, Jiří

    2002-01-01

    Roč. 41, č. 10 (2002), s. 2392-2398 ISSN 0888-5885 R&D Projects: GA AV ČR IAA4072711; GA AV ČR IAA4072801 Keywords : hydrogen sulfide * limestone calcines * desulfurization Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.247, year: 2002

  17. Microaeration reduces hydrogen sulfide in biogas

    Science.gov (United States)

    Although there are a variety of biological and chemical treatments for removal of hydrogen sulfide (H2S) from biogas, all require some level of chemical or water inputs and maintenance. In practice, managing biogas H2S remains a significant challenge for agricultural digesters where labor and opera...

  18. Support Effect in Hydrodesulfurization over Ruthenium Sulfide

    Czech Academy of Sciences Publication Activity Database

    Gulková, Daniela; Kaluža, Luděk; Vít, Zdeněk; Zdražil, Miroslav

    2009-01-01

    Roč. 51, č. 2 (2009), s. 146-149 ISSN 1337-7027 R&D Projects: GA ČR GA104/06/0705 Institutional research plan: CEZ:AV0Z40720504 Keywords : ruthenium sulfide * hydrodesulfurization * support effect Subject RIV: CC - Organic Chemistry

  19. Monitoring sulfide and sulfate-reducing bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Tanner, R.S.

    1995-12-31

    Simple yet precise and accurate methods for monitoring sulfate-reducing bacteria (SRB) and sulfide remain useful for the study of bacterial souring and corrosion. Test kits are available to measure sulfide in field samples. A more precise methylene blue sulfide assay for both field and laboratory studies is described here. Improved media, compared to that in API RP-38, for enumeration of SRB have been formulated. One of these, API-RST, contained cysteine (1.1 mM) as a reducing agent, which may be a confounding source of sulfide. While cysteine was required for rapid enumeration of SRB from environmental samples, the concentration of cysteine in medium could be reduced to 0.4 mM. It was also determined that elevated levels of yeast extract (>1 g/liter) could interfere with enumeration of SRB from environmental samples. The API-RST medium was modified to a RST-11 medium. Other changes in medium composition, in addition to reduction of cysteine, included reduction of the concentration of phosphate from 3.4 mM to 2.2 mM, reduction of the concentration of ferrous iron from 0.8 mM to 0.5 mM and preparation of a stock mineral solution to ease medium preparation. SRB from environmental samples could be enumerated in a week in this medium.

  20. Acid volatile sulfide (AVS)- a comment

    NARCIS (Netherlands)

    Meysman, F.J.R.; Middelburg, J.J.

    2005-01-01

    The review by Rickard and Morse (this volume) adequately summarizes our current understanding with respect to acid-volatile sulfides (AVS). At the same time, this review addresses some of the misunderstandings with regard to measurements and dynamics of this important sedimentary sulfur pool. In

  1. Carbon a support for sulfide catalysts

    NARCIS (Netherlands)

    Vissers, J.P.R.; Lensing, T.J.; Mercx, F.P.M.; Beer, de V.H.J.; Prins, R.

    1983-01-01

    Two types of carbon materials, carbon black composite and carbon covered alumina, were studied for-their use as support for sulfide catalysts. The following parameters were varied: type of carbon black, carbon coverage of the alumina and carbon pretreatment. Pore size distributions were determined

  2. Bioavailability of mercury in contaminated Oak Ridge watershed and potential remediation of river/runoff/storm water by an aquatic plant - 16319

    International Nuclear Information System (INIS)

    Su, Yi; Han, Fengxiang X.; Chen, Jian; Xia, Yunju; Monts, David L.

    2009-01-01

    Historically as part of its national security mission, the U.S. Department of Energy's Y-12 National Security Facility in Oak Ridge, TN, USA acquired a significant fraction of the world's supply of elemental mercury. During the 1950's and 1960's, a large amount of elemental mercury escaped confinement and is still present in the buildings and grounds of the Y-12 Facility and in the Y-12 Watershed. Because of the adverse effects of elemental mercury and mercury compounds upon human health, the Oak Ridge Site is engaged in an on-going effort to monitor and remediate the area. The main thrust of the Oak Ridge mercury remediation effort is currently scheduled for implementation in FY09. In order to more cost effectively implement those extensive remediation efforts, it is necessary now to obtain an improved understanding of the role that mercury and mercury compounds play in the Oak Ridge ecosystem. Most recently, concentrations of both total mercury and methylmercury in fish and water of lower East Fork Poplar Creek (LEFPC) of Oak Ridge increased although the majority of mercury in the site is mercury sulfide. This drives the US DOE and the Oak Ridge Site to study the long-term bioavailability of mercury and speciation at the site. The stability and bioavailability of mercury sulfide as affected by various biogeochemical conditions -presence of iron oxides have been studied. We examined the kinetic rate of dissolution of cinnabar from Oak Ridge soils and possible mechanisms and pathways in triggering the most recent increase of mercury solubility, bioavailability and mobility in Oak Ridge site. The effects of pH and chlorine on oxidative dissolution of cinnabar from cinnabar-contaminated Oak Ridge soils is discussed. On the other hand, aquatic plants might be good candidate for phyto-remediate contaminated waste water and phyto-filtration of collective storm water and surface runoff and river. Our greenhouse studies on uptake of Hg by water lettuce (Pistia stratiotes

  3. Re-processing CRT phosphors for mercury-free applications

    International Nuclear Information System (INIS)

    Dexpert-Ghys, Jeannette; Regnier, Sophie; Canac, Sophie; Beaudette, Tristan; Guillot, Philippe; Caillier, Bruno; Mauricot, Robert; Navarro, Julien; Sekhri, Salem

    2009-01-01

    This study is part of an operation in the framework of treatment and revalorization of IEEE (Informatics, Electronics and related) wastes. It aims to recover the active phosphors in cathode ray tubes (CRTs) and to re-cycle these powders by appropriate treatments as phosphors for mercury-free applications such as plasma display panels, flat lamps, advertising and lighting. The studied waste comes from a large panel of CRTs from any supplier. Several thermo-chemical treatments have been investigated. The removal of zinc sulfide-based phosphors and the recovery of a red phosphor Y 2 O 3 :Eu 3+ has been achieved by one (basic attack) route. The photoluminescence efficiency under VUV excitation of the obtained powders is at most 30% that of a commercial phosphor. The second route (acid attack) appears less promising. It has been established that silicate-based impurities could prevent isolating the yttrium based phosphor.

  4. Re-processing CRT phosphors for mercury-free applications

    Energy Technology Data Exchange (ETDEWEB)

    Dexpert-Ghys, Jeannette, E-mail: jdexpert@cemes.f [CEMES, 29 rue Jeanne Marvig, BP 94347, 31055 Toulouse cedex 4 (France); Regnier, Sophie; Canac, Sophie [ICAM, 75 avenue de Grande Bretagne, 31300 Toulouse (France); Beaudette, Tristan; Guillot, Philippe; Caillier, Bruno [DPHE, Universite Jean Francois Champollion, place de Verdun, 81012 Albi cedex 9 (France); Mauricot, Robert; Navarro, Julien [CEMES, 29 rue Jeanne Marvig, BP 94347, 31055 Toulouse cedex 4 (France); Sekhri, Salem [ENVOI, Cheminement Glueck, 31100 Toulouse (France)

    2009-12-15

    This study is part of an operation in the framework of treatment and revalorization of IEEE (Informatics, Electronics and related) wastes. It aims to recover the active phosphors in cathode ray tubes (CRTs) and to re-cycle these powders by appropriate treatments as phosphors for mercury-free applications such as plasma display panels, flat lamps, advertising and lighting. The studied waste comes from a large panel of CRTs from any supplier. Several thermo-chemical treatments have been investigated. The removal of zinc sulfide-based phosphors and the recovery of a red phosphor Y{sub 2}O{sub 3}:Eu{sup 3+} has been achieved by one (basic attack) route. The photoluminescence efficiency under VUV excitation of the obtained powders is at most 30% that of a commercial phosphor. The second route (acid attack) appears less promising. It has been established that silicate-based impurities could prevent isolating the yttrium based phosphor.

  5. Rotation of the planet mercury.

    Science.gov (United States)

    Jefferys, W H

    1966-04-08

    The equations of motion for the rotation of Mercury are solved for the general case by an asymptotic expansion. The findings of Liu and O'Keefe, obtained by numerical integration of a special case, that it is possible for Mercury's rotation to be locked into a 2:3 resonance with its revolution, are confirmed in detail. The general solution has further applications.

  6. Mercury: Exploration of a Planet

    Science.gov (United States)

    1976-01-01

    The flight of the Mariner 10 spacecraft to Venus and Mercury is detailed in animation and photography. Views of Mercury are featured. Also included is animation on the origin of the solar system. Dr. Bruce C. Murray, director of the Jet Propulsion Laboratory, comments on the mission.

  7. 49 CFR 173.164 - Mercury (metallic and articles containing mercury).

    Science.gov (United States)

    2010-10-01

    ... ounces) of mercury per package; (iv) Tubes which are completely jacketed in sealed leakproof metal cases... 49 Transportation 2 2010-10-01 2010-10-01 false Mercury (metallic and articles containing mercury... Than Class 1 and Class 7 § 173.164 Mercury (metallic and articles containing mercury). (a) For...

  8. Study on the sulfidation behavior of smithsonite

    International Nuclear Information System (INIS)

    Wu, Dandan; Wen, Shuming; Deng, Jiushuai; Liu, Jian; Mao, Yingbo

    2015-01-01

    Highlights: • Zeta potential showed that the pH IEP of smithsonite decreased from 7.7 to 6. • ICP test showed the gradual reduction of C S in the solution. • SEM showed that the mineral surface was partially changed to ZnS film. • XPS indicated that the presence of a characteristic signal peak of sulfur ions. - Abstract: Zinc extraction from low-grade mineral resources of oxidized zinc has recently become a focus of study. Sulfidation is an important process in oxidized ore flotation. In this study, the influence of sulfur ion adsorption on smithsonite surface was investigated with the use of zeta potential, inductively coupled plasma (ICP), scanning electron microscope (SEM), and X-ray photoelectron spectroscopic studies. Zeta potential measurements of sodium sulfide showed that sulfur ions were adsorbed onto the surface of pure smithsonite, as evidenced by the increased negative charge and the decrease in the pH IEP of smithsonite from 7.7 to 6 after sodium sulfide treatment. The ICP test revealed the gradual reduction in sulfur ion adsorption onto the surface of smithsonite in pulp sulfur. After 30 min of absorption, C S in the solution declined from 1000 × 10 −6 mol/L to 1.4 × 10 −6 mol/L. SEM results showed that the mineral surface was partially changed to ZnS film after sodium sulfide treatment, whereas EDS analysis results showed that 2% S is contained on the smithsonite surface. X-ray photoelectron spectroscopy results indicated the presence of a characteristic signal peak of sulfur ions after sulfidation. Sulfur concentration increased to 11.89%, whereas oxygen concentration decreased from 42.31% to 13.74%. Sulfur ions were not only present during chemical adsorption, but were also incorporated into the crystal lattices of minerals by the exchange reaction between S 2− and CO 3 2− ions

  9. Methyl mercury in terrestrial compartments

    International Nuclear Information System (INIS)

    Stoeppler, M.; Burow, M.; Padberg, S.; May, K.

    1993-09-01

    On the basis of the analytical methodology available at present the state of the art for the determination of total mercury and of various organometallic compounds of mercury in air, precipitation, limnic systems, soils, plants and biota is reviewed. This is followed by the presentation and discussion of examples for the data obtained hitherto for trace and ultratrace levels of total mercury and mainly methyl mercury in terrestrial and limnic environments as well as in biota. The data discussed stem predominantly from the past decade in which, due to significant methodological progress, many new aspects were elucidated. They include the most important results in this area achieved by the Research Centre (KFA) Juelich within the project 'Origin and Fate of Methyl Mercury' (contracts EV4V-0138-D and STEP-CT90-0057) supported by the Commission of the European Communities, Brussels. (orig.) [de

  10. Human Exposure and Health Effects of Inorganic and Elemental Mercury

    OpenAIRE

    Park, Jung-Duck; Zheng, Wei

    2012-01-01

    Mercury is a toxic and non-essential metal in the human body. Mercury is ubiquitously distributed in the environment, present in natural products, and exists extensively in items encountered in daily life. There are three forms of mercury, i.e., elemental (or metallic) mercury, inorganic mercury compounds, and organic mercury compounds. This review examines the toxicity of elemental mercury and inorganic mercury compounds. Inorganic mercury compounds are water soluble with a bioavailability o...

  11. Methods for dispensing mercury into devices

    Science.gov (United States)

    Grossman, Mark W.; George, William A.

    1987-04-28

    A process for dispensing mercury into devices which requires mercury. Mercury is first electrolytically separated from either HgO or Hg.sub.2 Cl.sub.2 and plated onto a cathode wire. The cathode wire is then placed into a device requiring mercury.

  12. Determination of mercury in plant material

    Energy Technology Data Exchange (ETDEWEB)

    Pickard, J A; Martin, J T

    1960-07-01

    An analytical procedure used for the determination of traces of mercury in plant material is described. The conditions of combustion of organic matter are controlled to avoid loss of mercury and EDTA is used to reduce the values for apparent mercury on uncontaminated samples. Satisfactory recoveries of mercury added to apples, tomatoes and coffee are obtained. 10 references, 1 table.

  13. Mercury's Lithospheric Magnetization

    Science.gov (United States)

    Johnson, C.; Phillips, R. J.; Philpott, L. C.; Al Asad, M.; Plattner, A.; Mast, S.; Kinczyk, M. J.; Prockter, L. M.

    2017-12-01

    Magnetic field data obtained by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft have been used to demonstrate the presence of lithospheric magnetization on Mercury. Larger amplitude fields resulting from the core dynamo and the strongly time-varying magnetospheric current systems are first estimated and subtracted from the magnetic field data to isolate lithospheric signals with wavelengths less than 500 km. These signals (hereafter referred to as data) are only observed at spacecraft altitudes less than 120 km, and are typically a few to 10 nT in amplitude. We present and compare equivalent source dipole magnetization models for latitudes 35°N to 75°N obtained from two distinct approaches to constrain the distribution and origin of lithospheric magnetization. First, models that fit either the data or the surface field predicted from a regional spherical harmonic representation of the data (see Plattner & Johnson abstract) and that minimize the root mean square (RMS) value of the magnetization are derived. Second, models in which the spatial distribution of magnetization required to fit the data is minimized are derived using the approach of Parker (1991). As seen previously, the largest amplitudes of lithospheric magnetization are concentrated around the Caloris basin. With this exception, across the northern hemisphere there are no overall correlations of magnetization with surface geology, although higher magnetizations are found in regions with darker surfaces. Similarly, there is no systematic correlation of magnetization signatures with crater materials, although there are specific instances of craters with interiors or ejecta that have magnetizations distinct from the surrounding region. For the latter case, we observe no correlation of the occurrence of these signatures with crater degradation state (a proxy for age). At the lowest spacecraft altitudes (source depths less than O(10 km) are unlikely in most regions

  14. Radar observations of Mercury

    International Nuclear Information System (INIS)

    Harmon, J.K.; Campbell, D.B.

    1988-01-01

    Some of the radar altimetry profiles of Mercury obtained on the basis of data from the Arecibo Observatory are presented. In these measurements, the delay-Doppler method was used to measure altitudes along the Doppler equator, rather than to map radar reflectivity. The profiles, derived from observations made over a 6-yr period, provide extensive coverage over a restricted equatorial band and permit the identification of radar signatures for features as small as 50-km diameter craters and 1-km-high arcuate scarps. The data allowed identification of large-scale topographic features such as smooth plains subsidence zones and major highland regions

  15. Fluorescent sensor for mercury

    Science.gov (United States)

    Wang, Zidong [Urbana, IL; Lee, Jung Heon [Evanston, IL; Lu, Yi [Champaign, IL

    2011-11-22

    The present invention provides a sensor for detecting mercury, comprising: a first polynucleotide, comprising a first region, and a second region, a second polynucleotide, a third polynucleotide, a fluorophore, and a quencher, wherein the third polynucleotide is optionally linked to the second region; the fluorophore is linked to the first polynucleotide and the quencher is linked to the second polynucleotide, or the fluorophore is linked to the second polynucleotide and the quencher is linked to the first polynucleotide; the first region and the second region hybridize to the second polynucleotide; and the second region binds to the third polynucleotide in the presence of Hg.sup.2+ ions.

  16. Cysteine Addition Promotes Sulfide Production and 4-Fold Hg(II)-S Coordination in Actively Metabolizing Escherichia coli.

    Science.gov (United States)

    Thomas, Sara A; Gaillard, Jean-François

    2017-04-18

    The bacterial uptake of mercury(II), Hg(II), is believed to be energy-dependent and is enhanced by cysteine in diverse species of bacteria under aerobic and anaerobic conditions. To gain insight into this Hg(II) biouptake pathway, we have employed X-ray absorption spectroscopy (XAS) to investigate the relationship between exogenous cysteine, cellular metabolism, cellular localization, and Hg(II) coordination in aerobically respiring Escherichia coli (E. coli). We show that cells harvested in exponential growth phase consistently display mixtures of 2-fold and 4-fold Hg(II) coordination to sulfur (Hg-S 2 and Hg-S 4 ), with added cysteine enhancing Hg-S 4 formation. In contrast, cells in stationary growth phase or cells treated with a protonophore causing a decrease in cellular ATP predominantly contain Hg-S 2 , regardless of cysteine addition. Our XAS results favor metacinnabar (β-HgS) as the Hg-S 4 species, which we show is associated with both the cell envelope and cytoplasm. Additionally, we observe that added cysteine abiotically oxidizes to cystine and exponentially growing E. coli degrade high cysteine concentrations (100-1000 μM) into sulfide. Thermodynamic calculations confirm that cysteine-induced sulfide biosynthesis can promote the formation of dissolved and particulate Hg(II)-sulfide species. This report reveals new complexities arising in Hg(II) bioassays with cysteine and emphasizes the need for considering changes in chemical speciation as well as growth stage.

  17. Sulfurization of Dissolved Organic Matter Increases Hg-Sulfide-Dissolved Organic Matter Bioavailability to a Hg-Methylating Bacterium.

    Science.gov (United States)

    Graham, Andrew M; Cameron-Burr, Keaton T; Hajic, Hayley A; Lee, Connie; Msekela, Deborah; Gilmour, Cynthia C

    2017-08-15

    Reactions of dissolved organic matter (DOM) with aqueous sulfide (termed sulfurization) in anoxic environments can substantially increase DOM's reduced sulfur functional group content. Sulfurization may affect DOM-trace metal interactions, including complexation and metal-containing particle precipitation, aggregation, and dissolution. Using a diverse suite of DOM samples, we found that susceptibility to additional sulfur incorporation via reaction with aqueous sulfide increased with increasing DOM aromatic-, carbonyl-, and carboxyl-C content. The role of DOM sulfurization in enhancing Hg bioavailability for microbial methylation was evaluated under conditions typical of Hg methylation environments (μM sulfide concentrations and low Hg-to-DOM molar ratios). Under the conditions of predicted metacinnabar supersaturation, microbial Hg methylation increased with increasing DOM sulfurization, likely reflecting either effective inhibition of metacinnabar growth and aggregation or the formation of Hg(II)-DOM thiol complexes with high bioavailability. Remarkably, Hg methylation efficiencies with the most sulfurized DOM samples were similar (>85% of total Hg methylated) to that observed in the presence of l-cysteine, a ligand facilitating rapid Hg(II) biouptake and methylation. This suggests that complexes of Hg(II) with DOM thiols have similar bioavailability to Hg(II) complexes with low-molecular-weight thiols. Overall, our results are a demonstration of the importance of DOM sulfurization to trace metal and metalloid (especially mercury) fate in the environment. DOM sulfurization likely represents another link between anthropogenic sulfate enrichment and MeHg production in the environment.

  18. Mercury kinetics in marine zooplankton

    International Nuclear Information System (INIS)

    Fowler, S.W.; Heyraud, M.; LaRosa, J.

    1976-01-01

    Mercury, like many other heavy metals, is potentially available to marine animals by uptake directly from water and/or through the organisms food. Furthermore, bioavailability, assimilation and subsequent retention in biota may be affected by the chemical species of the element in sea water. While mercury is known to exist in the inorganic form in sea water, recent work has indicated that, in certain coastal areas, a good portion of the total mercury appears to be organically bound; however, the exact chemical nature of the organic fraction has yet to be determined. Methyl mercury may be one constituent of the natural organically bound fraction since microbial mechanisms for in situ methylation of mercury have been demonstrated in the aquatic environment. Despite the fact that naturally produced methyl mercury probably comprises only a small fraction of an aquatic ecosystem, the well-documented toxic effects of this organo-mercurial, caused by man-made introductions into marine food chains, make it an important compound to study

  19. Volcanic mercury in Pinus canariensis

    Science.gov (United States)

    Rodríguez Martín, José Antonio; Nanos, Nikos; Miranda, José Carlos; Carbonell, Gregoria; Gil, Luis

    2013-08-01

    Mercury (Hg) is a toxic element that is emitted to the atmosphere by both human activities and natural processes. Volcanic emissions are considered a natural source of mercury in the environment. In some cases, tree ring records taken close to volcanoes and their relation to volcanic activity over time are contradictory. In 1949, the Hoyo Negro volcano (La Palma-Canary Islands) produced significant pyroclastic flows that damaged the nearby stand of Pinus canariensis. Recently, 60 years after the eruption, we assessed mercury concentrations in the stem of a pine which survived volcano formation, located at a distance of 50 m from the crater. We show that Hg content in a wound caused by pyroclastic impacts (22.3 μg kg-1) is an order of magnitude higher than the Hg concentrations measured in the xylem before and after the eruption (2.3 μg kg-1). Thus, mercury emissions originating from the eruption remained only as a mark—in pyroclastic wounds—and can be considered a sporadic and very high mercury input that did not affect the overall Hg input in the xylem. In addition, mercury contents recorded in the phloem (9.5 μg kg-1) and bark (6.0 μg kg-1) suggest that mercury shifts towards non-living tissues of the pine, an aspect that can be related to detoxification in volcanism-adapted species.

  20. Atmospheric mercury footprints of nations.

    Science.gov (United States)

    Liang, Sai; Wang, Yafei; Cinnirella, Sergio; Pirrone, Nicola

    2015-03-17

    The Minamata Convention was established to protect humans and the natural environment from the adverse effects of mercury emissions. A cogent assessment of mercury emissions is required to help implement the Minamata Convention. Here, we use an environmentally extended multi-regional input-output model to calculate atmospheric mercury footprints of nations based on upstream production (meaning direct emissions from the production activities of a nation), downstream production (meaning both direct and indirect emissions caused by the production activities of a nation), and consumption (meaning both direct and indirect emissions caused by final consumption of goods and services in a nation). Results show that nations function differently within global supply chains. Developed nations usually have larger consumption-based emissions than up- and downstream production-based emissions. India, South Korea, and Taiwan have larger downstream production-based emissions than their upstream production- and consumption-based emissions. Developed nations (e.g., United States, Japan, and Germany) are in part responsible for mercury emissions of developing nations (e.g., China, India, and Indonesia). Our findings indicate that global mercury abatement should focus on multiple stages of global supply chains. We propose three initiatives for global mercury abatement, comprising the establishment of mercury control technologies of upstream producers, productivity improvement of downstream producers, and behavior optimization of final consumers.

  1. Volcanic mercury in Pinus canariensis.

    Science.gov (United States)

    Rodríguez Martín, José Antonio; Nanos, Nikos; Miranda, José Carlos; Carbonell, Gregoria; Gil, Luis

    2013-08-01

    Mercury (Hg) is a toxic element that is emitted to the atmosphere by both human activities and natural processes. Volcanic emissions are considered a natural source of mercury in the environment. In some cases, tree ring records taken close to volcanoes and their relation to volcanic activity over time are contradictory. In 1949, the Hoyo Negro volcano (La Palma-Canary Islands) produced significant pyroclastic flows that damaged the nearby stand of Pinus canariensis. Recently, 60 years after the eruption, we assessed mercury concentrations in the stem of a pine which survived volcano formation, located at a distance of 50 m from the crater. We show that Hg content in a wound caused by pyroclastic impacts (22.3 μg kg(-1)) is an order of magnitude higher than the Hg concentrations measured in the xylem before and after the eruption (2.3 μg kg(-1)). Thus, mercury emissions originating from the eruption remained only as a mark-in pyroclastic wounds-and can be considered a sporadic and very high mercury input that did not affect the overall Hg input in the xylem. In addition, mercury contents recorded in the phloem (9.5 μg kg(-1)) and bark (6.0 μg kg(-1)) suggest that mercury shifts towards non-living tissues of the pine, an aspect that can be related to detoxification in volcanism-adapted species.

  2. Method for removal and stabilization of mercury in mercury-containing gas streams

    Science.gov (United States)

    Broderick, Thomas E.

    2005-09-13

    The present invention is directed to a process and apparatus for removing and stabilizing mercury from mercury-containing gas streams. A gas stream containing vapor phase elemental and/or speciated mercury is contacted with reagent, such as an oxygen-containing oxidant, in a liquid environment to form a mercury-containing precipitate. The mercury-containing precipitate is kept or placed in solution and reacts with one or more additional reagents to form a solid, stable mercury-containing compound.

  3. Hydrogen sulfide concentration in Beaver Dam Creek

    International Nuclear Information System (INIS)

    Kiser, D.L.

    1979-01-01

    Concentration-time profiles calculated with LODIPS for various hypothetical releases of hydrogen sulfide from the heavy water extraction facility predict lethal conditions for swamp fish from releases as small as 568 kg discharged over a period of 30 minutes or from releases of 1818 kg discharged over a period of 6 hours or less. The necessary volatilization and oxidation coefficients for LODIPS were derived from field measurements following planned releases of H 2 S. Upsets in the operation of the wastewater strippers in the Girdler-Sulfide (GS) heavy water extraction facility in D Area have released significant amounts of dissolved H 2 S to Beaver Dam Creek. Because H 2 S is toxic to fish in concentrations as low as 1 mg/liter, the downstream environmental impact of H 2 S releases from D Area was evaluated

  4. Iron-sulfide redox flow batteries

    Science.gov (United States)

    Xia, Guan-Guang; Yang, Zhenguo; Li, Liyu; Kim, Soowhan; Liu, Jun; Graff, Gordon L

    2013-12-17

    Iron-sulfide redox flow battery (RFB) systems can be advantageous for energy storage, particularly when the electrolytes have pH values greater than 6. Such systems can exhibit excellent energy conversion efficiency and stability and can utilize low-cost materials that are relatively safer and more environmentally friendly. One example of an iron-sulfide RFB is characterized by a positive electrolyte that comprises Fe(III) and/or Fe(II) in a positive electrolyte supporting solution, a negative electrolyte that comprises S.sup.2- and/or S in a negative electrolyte supporting solution, and a membrane, or a separator, that separates the positive electrolyte and electrode from the negative electrolyte and electrode.

  5. The partitioning of mercury in the solids components of forest soils and flooded forest soils in a hydroelectric reservoir, Quebec

    International Nuclear Information System (INIS)

    Dmytriw, R.P.

    1993-11-01

    Upon inundation, the soils in a hydroelection reservoir are subjected to several years of physical, biological and chemical changes as the transition from a terrestrial to an aquatic ecosystem is achieved. Changes in Eh, pH and microbial activity are believed to alter the metal binding capacity of solid substrates (organic matter, reactive Fe and Mn oxides, and clay minerals) within the soil profile, leading to remobilization of mercury associated with these phases. Four cores were collected along a transect from an unflooded forest soil to a pre-impoundment lake bottom sediment in the La-Grande-2 reservoir and watershed. The samples were sequentially extracted to determine the distribution of mercury between three operationally defined solid compartments: organic carbon, reactive Fe and Mn oxides/hydroxides, and the solid clay residue. Results indicate that up to 80% of the mercury in the O-horizon in forest soils and flooded forest soils, and up to 85% of the mercury in the lake sediments is bound to NaOH extractable organic carbon fractions. In the B-horizon podzol where organic content is low, 40-60% of the total mercury was found to be associated with reactive Fe minerals. In contrast, the flooded soil contains very little reactive Fe at any depth and the associated mercury concentrations are low. It is proposed that, upon inundation, oxide minerals are reduced and Hg released to the pore waters where it is immediately bound to an available substrate. Analyses of the residues suggests that there is an enrichment of mercury in the residual fraction immediately above the B-horizon of a flooded soil while the sulfide mineralization appears to play a role in sequestering mercury in lake sediments. 14 refs., 22 figs., 3 tabs

  6. The effect of mercury deposition to ecosystem around coal-power plants in Tan-An peninsular, S. Korea

    Science.gov (United States)

    Kim, Y.; Lee, J.; Song, K.; Shin, S.; Han, J.; Hong, E.; Jung, G.

    2009-12-01

    According to UNEP’s Report in 2008, Korea is one of the largest mercury emitting country with emission amount of 32 tones and the contribution of stationary coal combustion is estimated around 59%, as one of major mercury emission sources. There are growing needs of ecosystem mercury monitoring to evaluate the effectiveness on mercury emission controls by regulations. Thus, the aim of this study was to identify the useful monitoring indicators by comparing mercury levels of various environmental matrices in different ecosystems. Tae-an coal power plant, located on the west coastal of Korea is selected for study sites since it is one of the largest coal power plant in Korea with 4000 MW capacities. We chose 2 reservoirs near to Tae-an coal power plant and 2 others in An-myeon and Baeg-ryeong island for control study. Total gaseous mercury of ambient air was 3.6, 4.5 and 1.2 ng/m3 for Tae-an, An-myeon and Baeg-ryeong sites, respectively. From these results, we investigated and compared total mercury and methylmercury concentrations in surface water, soil, sediment, leaves and freshwater fish between reservoirs, which were known for the indicators of mercury atmospheric deposition. Estimates for the potential rates of methylation and activities of sulfur reducing bacteria were also made by injection radioactive isotopes of 203Hg and 35S. Potential methylation rate and acid volatile sulfide formation potential were dramatically changed by depth and maximum values were found in the top sediment section.

  7. Exploring Mercury: The Iron Planet

    OpenAIRE

    Stevenson, David J.

    2004-01-01

    Planet Mercury is both difficult to observe and difficult to reach by spacecraft. Just one spacecraft, Mariner 10, flew by the planet 30 years ago. An upcoming NASA mission, MESSENGER, will be launched this year and will go into orbit around Mercury at the end of this decade. A European mission is planned for the following decade. It's worth going there because Mercury is a strange body and the history of planetary exploration has taught us that strangeness gives us insight into planetary ori...

  8. Chelation Therapy for Mercury Poisoning

    Directory of Open Access Journals (Sweden)

    Rong Guan

    2009-01-01

    Full Text Available Chelation therapy has been the major treatment for heavy metal poisoning. Various chelating agents have been developed and tested for treatment of heavy metal intoxications, including mercury poisoning. It has been clearly shown that chelating agents could rescue the toxicity caused by heavy metal intoxication, but the potential preventive role of chelating agents against heavy metal poisoning has not been explored much. Recent paper by Siddiqi and colleagues has suggested a protective role of chelating agents against mercury poisoning, which provides a promising research direction for broader application of chelation therapy in prevention and treatment of mercury poisoning.

  9. MESSENGER'S First Flyby of Mercury

    Science.gov (United States)

    Slavin, James A.

    2008-01-01

    The MESSENGER mission to Mercury offers our first opportunity to explore this planet's miniature magnetosphere since Mariner 10's brief fly-bys in 1974-5. The magnetosphere of Mercury is the smallest in the solar system with its magnetic field typically standing off the solar wind only - 1000 to 2000 km above the surface. An overview of the MESSENGER mission and its January 14th close flyby of Mercury will be provided. Primary science objectives and the science instrumentation will be described. Initial results from MESSENGER'S first flyby on January 14th, 2008 will be discussed with an emphasis on the magnetic field and charged particle measurements.

  10. Distribution and retention of organic and inorganic mercury in methyl mercury-treated neonatal rats

    International Nuclear Information System (INIS)

    Thomas, D.J.; Fisher, H.L.; Sumler, M.R.; Hall, L.L.; Mushak, P.

    1988-01-01

    Seven-day-old Long Evans rats received one mumol of 203 Hg-labeled methyl mercury/kg sc and whole body retention and tissue distribution of organic and inorganic mercury were examined for 32 days postdosing. Neonates cleared mercury slowly until 10 days postdosing when the clearance rate abruptly increased. During the interval when whole body clearance of mercury was extremely slow, methyl mercury was metabolized to inorganic mercury. Peak concentration of mercury in kidney occurred at 2 days postdosing. At 32 days postdosing, 8% of mercury in kidney was in an organic from. Liver mercury concentration peaked at 2 days postdosing and organic mercury accounted for 38% at 32 days postdosing. Brain concentrations of mercury peaked at 2 days postdosing. At 10 days postdosing, organic mercury accounted for 86% of the brain mercury burden, and, at 32 days postdosing, for 60%. The percentage of mercury body burden in pelt rose from 30 to 70% between 1 and 10 days postdosing. At 32 days postdosing pelt contained 85% of the body burden of mercury. At all time points, about 95% of mercury in pelt was in an organic form. Compartmental analysis of these data permitted development of a model to describe the distribution and excretion of organic and inorganic mercury in methyl mercury-treated neonatal rats

  11. Hydrogen sulfide prodrugs—a review

    Directory of Open Access Journals (Sweden)

    Yueqin Zheng

    2015-09-01

    Full Text Available Hydrogen sulfide (H2S is recognized as one of three gasotransmitters together with nitric oxide (NO and carbon monoxide (CO. As a signaling molecule, H2S plays an important role in physiology and shows great potential in pharmaceutical applications. Along this line, there is a need for the development of H2S prodrugs for various reasons. In this review, we summarize different H2S prodrugs, their chemical properties, and some of their potential therapeutic applications.

  12. Mercury speciation on three European mining districts by XANES techniques

    Science.gov (United States)

    Esbri, J. M.; Garcia-Noguero, E. M.; Guerrero, B.; Kocman, D.; Bernaus, A.; Gaona, X.; Higueras, P.; Alvarez, R.; Loredo, J.; Horvat, M.; Ávila, M.

    2009-04-01

    The mobility, bioavailability and toxicity of mercury in the environment depend on the chemical species in which is present in soil, sediments, water or air. In this work we used synchrotron radiation to determine mercury species in geological samples of three mercury mining districts: Almadén (Spain), Idria (Slovenia) and Asturias (Spain). The aim of this study was to find differences on mobility and bioavailability of mercury on three mining districts with different type of mineralization. For this porpoises we selected samples of ore, calcines, soils and stream sediments from the three sites, completely characterized by the Almadén School of Mines, Josef Stefan Institute of Ljubljana and Oviedo School of Mines. Speciation of mercury was carried out on Synchrotron Laboratories of Hamburg (HASYLAB) by XANES techniques. Spectra of pure compounds [HgCl2, HgSO4, HgO, CH3HgCl, Hg2Cl2 (calomel), HgSred (cinnabar), HgSblack (metacinnabar), Hg2NCl0.5(SO4)0.3(MoO4)0.1(CO3)0.1(H2O) (mosesite), Hg3S2Cl2 (corderoite), Hg3(SO4)O2 (schuetteite) y Hg2ClO (terlinguaite)] were obtained on transmittance mode. The number and type of the compounds required to reconstruct experimental spectra for each sample was obtained by PCA analysis and linear fitting of minimum quadratics of the pure compounds spectra. This offers a semiquantitative approach to the mineralogical constitution of each analyzed sample. The results put forward differences on the efficiency of roasting furnaces from the three studied sites, evidenced by the presence of metacinnabar on the less efficient (Almadén and Asturias) and absence on the most efficient (Idria). For the three studied sites, sulfide species (cinnabar and metacinnabar) were largely more abundant than soluble species (chlorides and sulfates). On the other hand, recent results on the mobility of both Hg and As on the target sites will be presented. These results correlate with the related chemical species found by XANES techniques.

  13. The Use of Bacteria for Remediation of Mercury Contaminated Groundwater

    Science.gov (United States)

    Many processes of mercury transformation in the environment are bacteria mediated. Mercury properties cause some difficulties of remediation of mercury contaminated environment. Despite the significance of the problem of mercury pollution, methods of large scale bioremediation ...

  14. Elimination of mercury in health care facilities.

    Science.gov (United States)

    2000-03-01

    Mercury is a persistent, bioaccumulative toxin that has been linked to numerous health effects in humans and wildlife. It is a potent neurotoxin that may also harm the brain, kidneys, and lungs. Unborn children and young infants are at particular risk for brain damage from mercury exposure. Hospitals' use of mercury in chemical solutions, thermometers, blood pressure gauges, batteries, and fluorescent lamps makes these facilities large contributors to the overall emission of mercury into the environment. Most hospitals recognize the dangers of mercury. In a recent survey, four out of five hospitals stated that they have policies in place to eliminate the use of mercury-containing products. Sixty-two percent of them require vendors to disclose the presence of mercury in chemicals that the hospitals purchase. Only 12 percent distribute mercury-containing thermometers to new parents. Ninety-two percent teach their employees about the health and environmental effects of mercury, and 46 percent teach all employees how to clean up mercury spills. However, the same study showed that many hospitals have not implemented their policies. Forty-two percent were not aware whether they still purchased items containing mercury. In addition, 49 percent still purchase mercury thermometers, 44 percent purchase mercury gastrointestinal diagnostic equipment, and 64 percent still purchase mercury lab thermometers.

  15. Simultaneous removal of sulfide, nitrate and acetate: Kinetic modeling

    International Nuclear Information System (INIS)

    Wang Aijie; Liu Chunshuang; Ren Nanqi; Han Hongjun; Lee Duujong

    2010-01-01

    Biological removal of sulfide, nitrate and chemical oxygen demand (COD) simultaneously from industrial wastewaters to elementary sulfur (S 0 ), N 2 , and CO 2 , or named the denitrifying sulfide (DSR) process, is a cost effective and environmentally friendly treatment process for high strength sulfide and nitrate laden organic wastewater. Kinetic model for the DSR process was established for the first time on the basis of Activated Sludge Model No. 1 (ASM1). The DSR experiments were conducted at influent sulfide concentrations of 200-800 mg/L, whose results calibrate the model parameters. The model correlates well with the DSR process dynamics. By introducing the switch function and the inhibition function, the competition between autotrophic and heterotrophic denitrifiers is quantitatively described and the degree of inhibition of sulfide on heterotrophic denitrifiers is realized. The model output indicates that the DSR reactor can work well at 0.5 1000 mg/L influent sulfide, however, the DSR system will break down.

  16. Microaeration for hydrogen sulfide removal in UASB reactor.

    Science.gov (United States)

    Krayzelova, Lucie; Bartacek, Jan; Kolesarova, Nina; Jenicek, Pavel

    2014-11-01

    The removal of hydrogen sulfide from biogas by microaeration was studied in Up-flow Anaerobic Sludge Blanket (UASB) reactors treating synthetic brewery wastewater. A fully anaerobic UASB reactor served as a control while air was dosed into a microaerobic UASB reactor (UMSB). After a year of operation, sulfur balance was described in both reactors. In UASB, sulfur was mainly presented in the effluent as sulfide (49%) and in biogas as hydrogen sulfide (34%). In UMSB, 74% of sulfur was detected in the effluent (41% being sulfide and 33% being elemental sulfur), 10% accumulated in headspace as elemental sulfur and 9% escaped in biogas as hydrogen sulfide. The efficiency of hydrogen sulfide removal in UMSB was on average 73%. Microaeration did not cause any decrease in COD removal or methanogenic activity in UMSB and the elemental sulfur produced by microaeration did not accumulate in granular sludge. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Reduction of produced elementary sulfur in denitrifying sulfide removal process.

    Science.gov (United States)

    Zhou, Xu; Liu, Lihong; Chen, Chuan; Ren, Nanqi; Wang, Aijie; Lee, Duu-Jong

    2011-05-01

    Denitrifying sulfide removal (DSR) processes simultaneously convert sulfide, nitrate, and chemical oxygen demand from industrial wastewater into elemental sulfur, dinitrogen gas, and carbon dioxide, respectively. The failure of a DSR process is signaled by high concentrations of sulfide in reactor effluent. Conventionally, DSR reactor failure is blamed for overcompetition for heterotroph to autotroph communities. This study indicates that the elementary sulfur produced by oxidizing sulfide that is a recoverable resource from sulfide-laden wastewaters can be reduced back to sulfide by sulfur-reducing Methanobacterium sp. The Methanobacterium sp. was stimulated with excess organic carbon (acetate) when nitrite was completely consumed by heterotrophic denitrifiers. Adjusting hydraulic retention time of a DSR reactor when nitrite is completely consumed provides an additional control variable for maximizing DSR performance.

  18. Study on the sulfidation behavior of smithsonite

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Dandan; Wen, Shuming, E-mail: shmwen@126.com; Deng, Jiushuai, E-mail: dengshuai689@163.com; Liu, Jian; Mao, Yingbo

    2015-02-28

    Highlights: • Zeta potential showed that the pH{sub IEP} of smithsonite decreased from 7.7 to 6. • ICP test showed the gradual reduction of C{sub S} in the solution. • SEM showed that the mineral surface was partially changed to ZnS film. • XPS indicated that the presence of a characteristic signal peak of sulfur ions. - Abstract: Zinc extraction from low-grade mineral resources of oxidized zinc has recently become a focus of study. Sulfidation is an important process in oxidized ore flotation. In this study, the influence of sulfur ion adsorption on smithsonite surface was investigated with the use of zeta potential, inductively coupled plasma (ICP), scanning electron microscope (SEM), and X-ray photoelectron spectroscopic studies. Zeta potential measurements of sodium sulfide showed that sulfur ions were adsorbed onto the surface of pure smithsonite, as evidenced by the increased negative charge and the decrease in the pH{sub IEP} of smithsonite from 7.7 to 6 after sodium sulfide treatment. The ICP test revealed the gradual reduction in sulfur ion adsorption onto the surface of smithsonite in pulp sulfur. After 30 min of absorption, C{sub S} in the solution declined from 1000 × 10{sup −6} mol/L to 1.4 × 10{sup −6} mol/L. SEM results showed that the mineral surface was partially changed to ZnS film after sodium sulfide treatment, whereas EDS analysis results showed that 2% S is contained on the smithsonite surface. X-ray photoelectron spectroscopy results indicated the presence of a characteristic signal peak of sulfur ions after sulfidation. Sulfur concentration increased to 11.89%, whereas oxygen concentration decreased from 42.31% to 13.74%. Sulfur ions were not only present during chemical adsorption, but were also incorporated into the crystal lattices of minerals by the exchange reaction between S{sup 2−} and CO{sub 3}{sup 2−} ions.

  19. Deconvolution of Thermal Emissivity Spectra of Mercury to their Endmember Counterparts measured in Simulated Mercury Surface Conditions

    Science.gov (United States)

    Varatharajan, I.; D'Amore, M.; Maturilli, A.; Helbert, J.; Hiesinger, H.

    2017-12-01

    The Mercury Radiometer and Thermal Imaging Spectrometer (MERTIS) payload of ESA/JAXA Bepicolombo mission to Mercury will map the thermal emissivity at wavelength range of 7-14 μm and spatial resolution of 500 m/pixel [1]. Mercury was also imaged at the same wavelength range using the Boston University's Mid-Infrared Spectrometer and Imager (MIRSI) mounted on the NASA Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii with the minimum spatial coverage of 400-600km/spectra which blends all rocks, minerals, and soil types [2]. Therefore, the study [2] used quantitative deconvolution algorithm developed by [3] for spectral unmixing of this composite thermal emissivity spectrum from telescope to their respective areal fractions of endmember spectra; however, the thermal emissivity of endmembers used in [2] is the inverted reflectance measurements (Kirchhoff's law) of various samples measured at room temperature and pressure. Over a decade, the Planetary Spectroscopy Laboratory (PSL) at the Institute of Planetary Research (PF) at the German Aerospace Center (DLR) facilitates the thermal emissivity measurements under controlled and simulated surface conditions of Mercury by taking emissivity measurements at varying temperatures from 100-500°C under vacuum conditions supporting MERTIS payload. The measured thermal emissivity endmember spectral library therefore includes major silicates such as bytownite, anorthoclase, synthetic glass, olivine, enstatite, nepheline basanite, rocks like komatiite, tektite, Johnson Space Center lunar simulant (1A), and synthetic powdered sulfides which includes MgS, FeS, CaS, CrS, TiS, NaS, and MnS. Using such specialized endmember spectral library created under Mercury's conditions significantly increases the accuracy of the deconvolution model results. In this study, we revisited the available telescope spectra and redeveloped the algorithm by [3] by only choosing the endmember spectral library created at PSL for unbiased model

  20. Mercury pollution: a transdisciplinary treatment

    National Research Council Canada - National Science Library

    Zuber, Sharon L; Newman, Michael C

    2012-01-01

    .... Also included are smaller case studies, such as the Minamata tragedy, fish consumption, and international treaties"-- "Mercury is the gravest chemical pollutant problem of our time, and this is...

  1. Mercury contamination in the Amazon

    International Development Research Centre (IDRC) Digital Library (Canada)

    Nancy Minogue

    contamination is mainly caused by deforestation upstream. ... The team expected to find that the mercury levels in the water, sediment, and soil decreased as they ... Methylmercury poisoning — known as Minamata Disease after the Japanese ...

  2. Mercury absorption in aqueous hypochlorite

    International Nuclear Information System (INIS)

    Zhao, L.L.; Rochelle, G.T.

    1999-01-01

    The absorption of elemental Hg vapor into aqueous hypochlorite was measured in a stirred tank reactor at 25 and 55C. NaOCl strongly absorbs Hg even at high pH. Low pH, high Cl - and high-temperature favor mercury absorption. Aqueous free Cl 2 was the active species that reacted with mercury. However, chlorine desorption was evident at high Cl - and pH 15 M -1 s -1 at 25C and 1.4x10 17 M -1 s -1 at 55C. Gas-phase reaction was observed between Hg and Cl 2 on apparatus surfaces. Strong mercury absorption in water was also detected with Cl 2 present. Results indicate that the chlorine concentration, moisture, and surface area contribute positively to mercury removal. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  3. Origin and composition of Mercury

    International Nuclear Information System (INIS)

    Lewis, J.S.

    1988-01-01

    The predictions of the expected range of composition of Mercury at the time of its formation made on the basis of a suite of condensation-accretion models of Mercury spanning a range of condensation temperature and accretion sampling functions appropriate to Mercury are examined. It is concluded that these compositonal models can, if modified to take into account the nonselective loss of most of the silicate component of the planet during accretion, provide compositional predictions for the Weidenschilling (1978, 1980) mechanism for the accretion of a metal-rich Mercury. The silicate portion would, in this case, contain 3.6 to 4.5 percent alumina, roughly 1 percent of alkali oxides, and between 0.5 and 6 percent FeO

  4. Localized surface plasmon resonance mercury detection system and methods

    Science.gov (United States)

    James, Jay; Lucas, Donald; Crosby, Jeffrey Scott; Koshland, Catherine P.

    2016-03-22

    A mercury detection system that includes a flow cell having a mercury sensor, a light source and a light detector is provided. The mercury sensor includes a transparent substrate and a submonolayer of mercury absorbing nanoparticles, e.g., gold nanoparticles, on a surface of the substrate. Methods of determining whether mercury is present in a sample using the mercury sensors are also provided. The subject mercury detection systems and methods find use in a variety of different applications, including mercury detecting applications.

  5. Carbon Solubility in Silicon-Iron-Bearing Metals during Core Formation on Mercury

    Science.gov (United States)

    Vander Kaaden, Kathleen E.; McCubbin, Francis M.; Ross, D. Kent; Rapp, Jennifer F.; Danielson, Lisa R.; Keller, Lindsay P.; Righter, Kevin

    2016-01-01

    Recent results obtained from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft showed the surface of Mercury has high S abundances (approximately 4 wt%) and low Iron(II) Oxide abundances (less than 2 wt%). Based on these extreme values, the oxygen fugacity of Mercury's surface materials was estimated to be approximately 3 to 7 log(sub 10) units below the IW buffer (Delta IW-3 to Delta IW-7). This highly reducing nature of the planet has resulted in a large core and relatively thin mantle, extending to only approximately 420 km depth (corresponding to a core-mantle boundary pressure of approximately 4-7 GPa) within the planet. Furthermore, MESSENGER results have suggested the presence of carbon on the surface of the planet. Previous experimental results from have also suggested the possibility of a primary floatation crust on Mercury composed of graphite, produced after a global magma ocean event. With these exotic conditions of this compositional end-member planet, it begs the question, what is the core composition of Mercury? Although no definitive conclusion has been reached, previous studies have made advances towards answering this question. Riner et al. and Chen et al. looked at iron sulfide systems and implemented various crystallization and layered core scenarios to try and determine the composition and structure of Mercury's core. Malavergne et al. examined core crystallization scenarios in the presence of sulfur and silicon. Hauck et al. used the most recent geophysical constraints from the MESSENGER spacecraft to model the internal structure of Mercury, including the core, in a iron-sulfur-silicon system. More recently, Chabot et al. conducted a series of metal-silicate partitioning experiments in a iron-sulfur-silicon system. These results showed the core of Mercury has the potential to contain more than 15 wt% silicon. However, with the newest results from MESSENGER's low altitude campaign, carbon is another

  6. Nanostructured silver sulfide: synthesis of various forms and their application

    Science.gov (United States)

    Sadovnikov, S. I.; Rempel, A. A.; Gusev, A. I.

    2018-04-01

    The results of experimental studies on nanostructured silver sulfide are analyzed and generalized. The influence of small particle size on nonstoichiometry of silver sulfide is discussed. Methods for the synthesis of various forms of nanostructured Ag2S including nanopowders, stable colloidal solutions, quantum dots, core–shell nanoparticles and heteronanostructures are described. The advantages and drawbacks of different synthetic procedures are analyzed. Main fields of application of nanostructured silver sulfide are considered. The bibliography includes 184 references.

  7. Mercury Toolset for Spatiotemporal Metadata

    Science.gov (United States)

    Devarakonda, Ranjeet; Palanisamy, Giri; Green, James; Wilson, Bruce; Rhyne, B. Timothy; Lindsley, Chris

    2010-06-01

    Mercury (http://mercury.ornl.gov) is a set of tools for federated harvesting, searching, and retrieving metadata, particularly spatiotemporal metadata. Version 3.0 of the Mercury toolset provides orders of magnitude improvements in search speed, support for additional metadata formats, integration with Google Maps for spatial queries, facetted type search, support for RSS (Really Simple Syndication) delivery of search results, and enhanced customization to meet the needs of the multiple projects that use Mercury. It provides a single portal to very quickly search for data and information contained in disparate data management systems, each of which may use different metadata formats. Mercury harvests metadata and key data from contributing project servers distributed around the world and builds a centralized index. The search interfaces then allow the users to perform a variety of fielded, spatial, and temporal searches across these metadata sources. This centralized repository of metadata with distributed data sources provides extremely fast search results to the user, while allowing data providers to advertise the availability of their data and maintain complete control and ownership of that data. Mercury periodically (typically daily)harvests metadata sources through a collection of interfaces and re-indexes these metadata to provide extremely rapid search capabilities, even over collections with tens of millions of metadata records. A number of both graphical and application interfaces have been constructed within Mercury, to enable both human users and other computer programs to perform queries. Mercury was also designed to support multiple different projects, so that the particular fields that can be queried and used with search filters are easy to configure for each different project.

  8. Mercury Toolset for Spatiotemporal Metadata

    Science.gov (United States)

    Wilson, Bruce E.; Palanisamy, Giri; Devarakonda, Ranjeet; Rhyne, B. Timothy; Lindsley, Chris; Green, James

    2010-01-01

    Mercury (http://mercury.ornl.gov) is a set of tools for federated harvesting, searching, and retrieving metadata, particularly spatiotemporal metadata. Version 3.0 of the Mercury toolset provides orders of magnitude improvements in search speed, support for additional metadata formats, integration with Google Maps for spatial queries, facetted type search, support for RSS (Really Simple Syndication) delivery of search results, and enhanced customization to meet the needs of the multiple projects that use Mercury. It provides a single portal to very quickly search for data and information contained in disparate data management systems, each of which may use different metadata formats. Mercury harvests metadata and key data from contributing project servers distributed around the world and builds a centralized index. The search interfaces then allow the users to perform a variety of fielded, spatial, and temporal searches across these metadata sources. This centralized repository of metadata with distributed data sources provides extremely fast search results to the user, while allowing data providers to advertise the availability of their data and maintain complete control and ownership of that data. Mercury periodically (typically daily) harvests metadata sources through a collection of interfaces and re-indexes these metadata to provide extremely rapid search capabilities, even over collections with tens of millions of metadata records. A number of both graphical and application interfaces have been constructed within Mercury, to enable both human users and other computer programs to perform queries. Mercury was also designed to support multiple different projects, so that the particular fields that can be queried and used with search filters are easy to configure for each different project.

  9. Precipitation and growth of zinc sulfide nanoparticles in the presence of thiol-containing natural organic ligands.

    Science.gov (United States)

    Lau, Boris L T; Hsu-Kim, Heileen

    2008-10-01

    In sulfidic aquatic systems, metal sulfides can control the mobility and bioavailability of trace metal pollutants such as zinc, mercury, and silver. Nanoparticles of ZnS and other metal sulfides are known to exist in oxic and anoxic waters. However, the processes that lead to their persistence in the aquatic environment are relatively unknown. The objective of this study was to evaluate the importance of dissolved natural organics in stabilizing nanoparticulate ZnS that precipitates under environmentally relevant conditions. Precipitation and growth of ZnS particles were investigated in the presence of dissolved humic acid and low-molecular weight organic acids that are prevalent in sediment porewater. Dynamic light scattering was used to monitor the hydrodynamic diameter of particles precipitating in laboratory solutions. Zn speciation was also measured by filtering the ZnS solutions (precipitation experiments and not to the dissolved organic ligands. X-ray photoelectron spectroscopy and electron microscopy were used to confirm that amorphous particles containing Zn and S were precipitating in the suspensions. Observed growth rates of ZnS particles varied by orders of magnitude, depending on the type and concentration of organic ligand in solution. In the presence of humic acid and thiol-containing ligands (cysteine, glutathione, and thioglycolate), observed growth rates decreased by 1-3 orders of magnitude relative to controls without the ligands. In contrast, growth rates of the particles were consistently within 1 order of magnitude of the ligand-free control when oxygen- and amine-containing ligands (oxalate, serine, and glycolate) were present Furthermore, particle growth rates decreased with an increase in thiol concentration and increased with NaNO3 electrolyte concentration. These studies suggest that specific surface interactions with thiol-containing organics may be one factor that contributes to the persistence of naturally occurring and anthropogenic

  10. Carbon steel protection in G.S. (Girlder sulfide) plants. Iron sulfide scales formation conditions. Pt. 1

    International Nuclear Information System (INIS)

    Bruzzoni, P.; Burkart, A.L.; Garavaglia, R.N.

    1981-11-01

    An ASTM A 516 degree 60 carbon steel superficial protection technique submitted to a hydrogen-water sulfide corrosive medium at 2 MPa of pressure and 40-125 deg C forming on itself an iron sulfide layer was tested. Studies on pH influence, temperature, passivating mean characteristics and exposure time as well as the mechanical resistance of sulfide layers to erosion are included. (Author) [es

  11. 76 FR 64022 - Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting

    Science.gov (United States)

    2011-10-17

    ... Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting AGENCY: Environmental Protection Agency (EPA). ACTION: Lifting of Administrative Stay for Hydrogen Sulfide. SUMMARY: EPA is announcing... (EPCRA) section 313 toxic chemical release reporting requirements for hydrogen sulfide (Chemical...

  12. Phytoremediation of Ionic and Methyl Mercury Pollution

    Energy Technology Data Exchange (ETDEWEB)

    Meagher, Richard B.

    2005-06-01

    Phytoremediation is defined as the use of plants to extract, resist, detoxify, and/or sequester toxic environmental pollutants. The long-term goal of the proposed research is to develop and test highly productive, field-adapted plant species that have been engineered for the phytoremediation of mercury. A variety of different genes, which should enable plants to clean mercury polluted sites are being tested as tools for mercury phytoremediation, first in model laboratory plants and then in potential field species. Several of these genes have already been shown to enhance mercury phytoremediation. Mercury pollution is a serious, world-wide problem affecting the health of human and wildlife populations. Environmentally, the most serious mercury threat is the production of methylmercury (CH3Hg+) by native bacteria at mercury contaminated wetland sites. Methylmercury is inherently more toxic than metallic (Hg(0)) or ionic (Hg(II)) mercury, and because methylmercury is prolifically biomagnified up the food chain, it poses the most immediate danger to animal populations. We have successfully engineered two model plants, Arabidopsis and tobacco, to use the bacterial merB gene to convert methylmercury to less toxic ionic mercury and to use the bacterial merA gene to further detoxify ionic mercury to the least toxic form of mercury, metallic mercury. Plants expressing both MerA and MerB proteins detoxify methylmercury in two steps to the metallic form. These plants germinate, grow, and set seed at normal growth rates on levels of methylmercury or ionic mercury that are lethal to normal plants. Our newest efforts involve engineering plants with several additional bacterial and plant genes that allow for higher levels of mercury resistance and mercury hyperaccumulation. The potential for these plants to hyperaccumulate mercury was further advanced by developing constitutive, aboveground, and root-specific gene expression systems. Our current strategy is to engineer plants to

  13. Autometallographic tracing of mercury in frog liver

    International Nuclear Information System (INIS)

    Loumbourdis, N.S.; Danscher, G.

    2004-01-01

    The distribution of mercury in the liver of the frog Rana ridibunda with the autometallographic method was investigated. The mercury specific autometallographic (HgS/Se AMG ) technique is a sensitive histochemical approach for tracing mercury in tissues from mercury-exposed organisms. Mercury accumulates in vivo as mercury sulphur/mercury selenium nanocrystals that can be silver-enhanced. Thus, only a fraction of the Hg can be visualized. Six animals were exposed for one day and another group of six animals for 6 days in 1 ppm mercury (as HgCI 2 ) dissolved in fresh water. A third group of six animals, served as controls, were sacrificed the day of arrival at the laboratory. First, mercury appears in the blood plasma and erythrocytes. Next, mercury moves to hepatocytes and in the apical part of the cells, that facing bile canaliculi. In a next step, mercury appears in the endothelial and Kupffer cells. It seems likely that, the mercury of hepatocytes moves through bile canaliculi to the gut, most probably bound to glutathione and/or other similar ligands. Most probably, the endothelial and Kupffer cells comprise the first line of defense against metal toxicity. - Frogs can be good bioindicators of mercury

  14. Mercury: Aspects of its ecology and environmental toxicity. [physiological effects of mercury compound contamination of environment

    Science.gov (United States)

    Siegel, S. M.

    1973-01-01

    A study was conducted to determine the effects of mercury pollution on the environment. The possible sources of mercury contamination in sea water are identified. The effects of mercury on food sources, as represented by swordfish, are analyzed. The physiological effects of varying concentrations of mercury are reported. Emphasis is placed on the situation existing in the Hawaiian Islands.

  15. 76 FR 13851 - National Emission Standards for Hazardous Air Pollutants: Mercury Emissions From Mercury Cell...

    Science.gov (United States)

    2011-03-14

    ... National Emission Standards for Hazardous Air Pollutants: Mercury Emissions From Mercury Cell Chlor-Alkali...-5] RIN 2060-AN99 National Emission Standards for Hazardous Air Pollutants: Mercury Emissions From Mercury Cell Chlor-Alkali Plants AGENCY: Environmental Protection Agency (EPA). ACTION: Supplemental...

  16. Groundwater Modeling Of Mercury Pollution At A Former Mercury Cell Chlor Alkali Facility In Pavoldar, Kazakhstan

    Science.gov (United States)

    In Kazakhstan, there is a serious case of mercury pollution near the city of Pavlodar from an old mercury cell chlor-alkali plant. The soil, sediment, and water is severly contaminated with mercury and mercury compounds as a result of the industrial activity of this chemical pla...

  17. Iron sulfide crystal growth: a literature review

    International Nuclear Information System (INIS)

    Dewar, E.J.

    1977-04-01

    Iron pyrite (FeS 2 ) is often found on trays and in heat exchangers in Girdler-Sulfide (G.S.) plants used to extract D 2 O from fresh water. A critical review of the literature was made to find: (i) what is known about FeS 2 crystal growth; (ii) which techniques could be used to study FeS 2 crystal growth experimentally; (iii) potential chemical additives that could be used in trace amounts to poison FeS 2 crystals and reduce their growth rate in G.S. plants. (author)

  18. Sulfide geochronlogy along the Southwest Indian Ridge

    Science.gov (United States)

    Yang, W.; Tao, C.; Li, H.; Liang, J.; Liao, S.

    2017-12-01

    Dragon Flag and Duanqiao hydrothermal field is located between the Indomed and Gallieni fracture zones in the ultraslow-spreading Southwest Indian Ridge (SWIR). Ten subsamples from active and inactive vents of Dragon Flag hydrothermal field and twenty-eight subsamples from Duanqiao hydrothermal field were dated using the 230Th/238U method. Four main episodes of hydrothermal activity of Duanqiao were determined according to the restricted results: 68.9-84.3, 43.9-48.4, 25.3-34.8, and 0.7-17.3 kyrs. Hydrothermal activity of Duanqiao probably started about 84.3 (±0.5) kyrs ago and ceased about 0.737 (±0.023) kyrs ago. And sulfide samples from the nearby Dragon Flag filed at the same time and the results show that the ages of most sulfides from Dragon Flag field range from 1.496(±0.176) to 5.416 (±0.116) kyrs with the oldest age estimated at 15.997 (±0.155) kyrs Münch et al. (2001) reconstructed the evolution history of Mt. Jourdanne hydrothermal field. The age dating results indicate activity in two episodes, at 70-40 and 27-13 kyrs. The hydrothermal activity in Dragon Flag field is much more recent than that of Duanqiao or Mt. Jourdanne fields. The massive sulfides are younger than the sulfides from other hydrothermal fields such as Rainbow, Sonne and Ashadze-2. All these results suggest that hydrothermal activity of Dragon Flag field is much more recent than that of Duanqiao or Mt. Jourdanne fields. Mt. Jourdanne is situated on an axial volcanic ridge which has both volcanic and tectonic activity. This is necessary to develop the heat source and pathways for the fluid convection, which enables the hydrothermal circulation. Hydrothermal activity in Dragon Flag Field is located next to the detachment fault termination. The detachment fault system provides a pathway for hydrothermal convection. Such style of heat source can contribute to continuous hydrothermal activity for over 1000 years. Duanqiao field is located near the central volcano and there is a hot

  19. Mercury - the hollow planet

    Science.gov (United States)

    Rothery, D. A.

    2012-04-01

    Mercury is turning out to be a planet characterized by various kinds of endogenous hole (discounting impact craters), which are compared here. These include volcanic vents and collapse features on horizontal scales of tens of km, and smaller scale depressions ('hollows') associated with bright crater-floor deposits (BCFD). The BCFD hollows are tens of metres deep and kilometres or less across and are characteristically flat-floored, with steep, scalloped walls. Their form suggests that they most likely result from removal of surface material by some kind of mass-wasting process, probably associated with volume-loss caused by removal (via sublimation?) of a volatile component. These do not appear to be primarily a result of undermining. Determining the composition of the high-albedo bluish surface coating in BCFDs will be a key goal for BepiColombo instruments such as MIXS (Mercury Imaging Xray Spectrometer). In contrast, collapse features are non-circular rimless pits, typically on crater floors (pit-floor craters), whose morphology suggests collapse into void spaces left by magma withdrawal. This could be by drainage of either erupted lava (or impact melt) or of shallowly-intruded magma. Unlike the much smaller-scale BCFD hollows, these 'collapse pit' features tend to lack extensive flat floors and instead tend to be close to triangular in cross-section with inward slopes near to the critical angle of repose. The different scale and morphology of BCFD hollows and collapse pits argues for quite different modes of origin. However, BCFD hollows adjacent to and within the collapse pit inside Scarlatti crater suggest that the volatile material whose loss was responsible for the growth of the hollows may have been emplaced in association with the magma whose drainage caused the main collapse. Another kind of volcanic collapse can be seen within a 25 km-wide volcanic vent outside the southern rim of the Caloris basin (22.5° N, 146.1° E), on a 28 m/pixel MDIS NAC image

  20. Mercury in dated Greenland marine sediments

    DEFF Research Database (Denmark)

    Asmund, G.; Nielsen, S.P.

    2000-01-01

    Twenty marine sediment cores from Greenland were analysed for mercury, and dated by the lead-210 method. In general the cores exhibit a mercury profile with higher mercury concentrations in the upper centimetres of the core. The cores were studied by linear regression of In Hg vs, age of the sedi......Twenty marine sediment cores from Greenland were analysed for mercury, and dated by the lead-210 method. In general the cores exhibit a mercury profile with higher mercury concentrations in the upper centimetres of the core. The cores were studied by linear regression of In Hg vs, age...... indicating that the mercury mainly originates from atmospheric washout. But the large variability indicates that other processes also influence the mercury flux to Arctic marine sediments. (C) 2000 Elsevier Science B.V. All rights reserved....

  1. Sorption of mercury on chemically synthesized polyaniline

    International Nuclear Information System (INIS)

    Remya Devi, P.S.; Verma, R.; Sudersanan, M.

    2006-01-01

    Sorption of inorganic mercury (Hg 2+ ) and methyl mercury, on chemically synthesized polyaniline, in 0.1-10N HCl solutions has been studied. Hg 2+ is strongly sorbed at low acidities and the extent of sorption decreases with increase in acidity. The sorption of methyl mercury is very low in the HCl concentration range studied. Sorption of Hg 2+ on polyaniline in 0.1-10N LiCl and H 2 SO 4 solutions has also been studied. The analysis of the data indicates that the sorption of Hg 2+ depends on the degree of protonation of polyaniline and the nature of mercury(II) chloride complexes in solution. X-ray photoelectron spectroscopy analysis (XPS) of polyaniline sorbed with mercury show that mercury is bound as Hg 2+ . Sorbed mercury is quantitatively eluted from polyaniline with 0.5N HNO 3 . Polyaniline can be used for separation and pre-concentration of inorganic mercury from aqueous samples. (author)

  2. Genetic effects of organic mercury compounds

    Energy Technology Data Exchange (ETDEWEB)

    Ramel, C

    1967-01-01

    Studies on the genetic and developmental effects of organic mercury compounds on lilies, drosophila, and ice were carried out. It was found that chromosomal and developmental abnormalities were correlated with the administration of mercury compounds.

  3. Mercury-Containing Devices and Demolition

    Science.gov (United States)

    Some items inside residential buildings contain mercury, which poses a persistent and toxic human health and environmental threat. These materials should be carefully salvaged for proper recycling to prevent mercury contamination prior to demolition.

  4. EPA Leadership in the Global Mercury Partnership

    Science.gov (United States)

    The Global Mercury Partnership is a voluntary multi-stakeholder partnership initiated in 2005 to take immediate actions to protect human health and the environment from the releases of mercury and its compounds to the environment.

  5. Mercury in Thana creek, Bombay harbour

    Digital Repository Service at National Institute of Oceanography (India)

    Zingde, M.D.; Desai, B.N.

    weight) with marked increased from harbour to the creek region suggests substantial mercury input in the head region. Chemical extraction by hydrogen peroxide indicated that more than 70% of mercury was leachable and probably organically bound...

  6. Mercury Lander Mission Concept Study Summary

    Science.gov (United States)

    Eng, D. A.

    2018-05-01

    Provides a summary of the Mercury Lander Mission Concept Study performed as part of the last Planetary Decadal Survey. The presentation will focus on engineering trades and the challenges of developing a Mercury lander mission.

  7. Mercury Emission Measurement in Coal-Fired Boilers by Continuous Mercury Monitor and Ontario Hydro Method

    Science.gov (United States)

    Zhu, Yanqun; Zhou, Jinsong; He, Sheng; Cai, Xiaoshu; Hu, Changxin; Zheng, Jianming; Zhang, Le; Luo, Zhongyang; Cen, Kefa

    2007-06-01

    The mercury emission control approach attaches more importance. The accurate measurement of mercury speciation is a first step. Because OH method (accepted method) can't provide the real-time data and 2-week time for results attained, it's high time to seek on line mercury continuous emission monitors(Hg-CEM). Firstly, the gaseous elemental and oxidized mercury were conducted to measure using OH and CEM method under normal operation conditions of PC boiler after ESP, the results between two methods show good consistency. Secondly, through ESP, gaseous oxidized mercury decrease a little and particulate mercury reduce a little bit, but the elemental mercury is just the opposite. Besides, the WFGD system achieved to gaseous oxidized mercury removal of 53.4%, gaseous overall mercury and elemental mercury are 37.1% and 22.1%, respectively.

  8. Method for the removal and recovery of mercury

    Science.gov (United States)

    Easterly, Clay E.; Vass, Arpad A.; Tyndall, Richard L.

    1997-01-01

    The present invention is an enhanced method for the removal and recovery of mercury from mercury-contaminated matrices. The method involves contacting a mercury-contaminated matrix with an aqueous dispersant solution derived from specific intra-amoebic isolates to release the mercury from the mercury-contaminated matrix and emulsify the mercury; then, contacting the matrix with an amalgamating metal from a metal source to amalgamate the mercury to the amalgamating metal; removing the metallic source from the mercury-contaminated matrix; and heating the metallic source to vaporize the mercury in a closed system to capture the mercury vapors.

  9. Study of the environmental cycling of mercury

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Frades, J P; Hildebrand, S G; Huckabee, J W; Murias, B; Diaz, F S; Wilson, R H

    1977-01-01

    A study of mercury in the environment is under way near the mercury mine at Almaden, Spain. The main aspects of the project are: ecology; atmospheric monitoring; and human studies. The mercury deposit at Almaden is described. The liquid effluent from the mine and smelter contains high concentrations of mercury that pollute nearby rivers. Sample collection and analytical methods used in the ecological survey are reviewed. Ecological experiments are considered. Air monitoring studies and human studies currently being performed are assessed. (1 map)

  10. Phytoremediation of Ionic and Methyl Mercury Pollution

    Energy Technology Data Exchange (ETDEWEB)

    Meagher, Richard B.

    2004-12-01

    Phytoremediation is defined as the use of plants to extract, resist, detoxify, and/or sequester toxic environmental pollutants. The long-term goal of the proposed research is to develop and test highly productive, field-adapted plant species that have been engineered for the phytoremediation of mercury. A variety of different genes, which should enable plants to clean mercury polluted sites are being tested as tools for mercury phytoremediation, first in model laboratory plants and then in potential field species. Several of these genes have already been shown to enhance mercury phytoremediation. Mercury pollution is a serious, world-wide problem affecting the health of human and wildlife populations. Environmentally, the most serious mercury threat is the production of methylmercury (CH3Hg+) by native bacteria at mercury contaminated wetland sites. Methylmercury is inherently more toxic than metallic (Hg(0)) or ionic (Hg(II)) mercury, and because methylmercury is prolifically biomagnified up the food chain, it poses the most immediate danger to animal populations. We have successfully engineered two model plants, Arabidopsis and tobacco, to use the bacterial merB gene to convert methylmercury to less toxic ionic mercury and to use the bacterial merA gene to further detoxify ionic mercury to the least toxic form of mercury, metallic mercury. Plants expressing both MerA and MerB proteins detoxify methylmercury in two steps to the metallic form. These plants germinate, grow, and set seed at normal growth rates on levels of methylmercury or ionic mercury that are lethal to normal plants. Our newest efforts involve engineering plants with several additional bacterial and plant genes that allow for higher levels of mercury resistance and mercury hyperaccumulation. The potential for these plants to hyperaccumulate mercury was further advanced by developing constitutive, aboveground, and root-specific gene expression systems.

  11. Microbial selenium sulfide reduction for selenium recovery from wastewater

    NARCIS (Netherlands)

    Hageman, S.P.W.; Weijden, van der R.D.; Stams, A.J.M.; Cappellen, van P.; Buisman, C.J.N.

    2017-01-01

    Microbial reduction of selenium sulfide (SeS2) is a key step in a new treatment process to recover selenium from selenate and selenite streams. In this process, selenate is first reduced to selenite, and subsequently selenite is reduced by sulfide and precipitates from the solution as SeS2. The

  12. Recent findings on sinks for sulfide in gravity sewer networks

    DEFF Research Database (Denmark)

    Nielsen, Asbjørn Haaning; Hvitved-Jacobsen, Thorkild; Vollertsen, Jes

    2006-01-01

    summarizes this newly obtained knowledge and emphasizes important implications of the findings. Model simulations of the in-sewer processes important for the sulfur cycle showed that sulfide oxidation in the wetted biofilm is typically the most important sink for dissolved sulfide in gravity sewers. However...

  13. Technetium behavior in sulfide and ferrous iron solutions

    International Nuclear Information System (INIS)

    Lee, S.Y.; Bondietti, E.A.

    1982-01-01

    Pertechnetate oxyanion ( 99 TcO 4- ), a potentially mobile species in leachate from a breached radioactive waste repository, was removed from a brine solution by precipitation with sulfide, iron, and ferrous sulfide at environmental pH's. Maghemite (ν-Fe 2 O 3 ) and geothite (α-FeOOH) were the dominant minerals in the precipitate obtained from the TcO 4- -ferrous iron reaction. The observation of small particle size and poor crystallinity of the minerals formed in the presence of Tc suggested that the Tc was incorporated into the mineral structure after reduction to a lower valence state. Amorphous ferrous sulfide, an initial phase precipitating in the TcO 4- -ferrous iron-sulfide reaction, was transformed to goethite and hematite (α-Fe 2 O 3 ) on aging. The black precipitate obtained from the TcO 4- -sulfide reaction was poorly crystallized technetium sulfide (Tc 2 S 7 ) which was insoluble in both acid and alkaline solution in the absence of strong oxidents. The results suggested that ferrous- and/or sulfide-bearing groundwaters and minerals in host rocks or backfill barriers could reduce the mobility of Tc through the formation of less-soluble Tc-bearing iron and/or sulfide minerals

  14. Sulfidation of carbon-supported iron oxide catalysts

    NARCIS (Netherlands)

    Ramselaar, W.L.T.M.; Hadders, R.H.; Gerkema, E.; Beer, de V.H.J.; Oers, van E.M.; Kraan, van der A.M.

    1989-01-01

    The sulfidation of carbon-supported iron oxide catalysts was studied by means of in-situ Mössbauer spectroscopy at temperatures down to 4.2 K. The catalysts were dried in two different ways and then sulfided in a flow of 10% H2S in H2 at temperatures between 293 and 773 K. Thiophene

  15. Mercury Continuous Emmission Monitor Calibration

    Energy Technology Data Exchange (ETDEWEB)

    John Schabron; Eric Kalberer; Ryan Boysen; William Schuster; Joseph Rovani

    2009-03-12

    Mercury continuous emissions monitoring systems (CEMs) are being implemented in over 800 coal-fired power plant stacks throughput the U.S. Western Research Institute (WRI) is working closely with the Electric Power Research Institute (EPRI), the National Institute of Standards and Technology (NIST), and the Environmental Protection Agency (EPA) to facilitate the development of the experimental criteria for a NIST traceability protocol for dynamic elemental mercury vapor calibrators/generators. These devices are used to calibrate mercury CEMs at power plant sites. The Clean Air Mercury Rule (CAMR) which was published in the Federal Register on May 18, 2005 and vacated by a Federal appeals court in early 2008 required that calibration be performed with NIST-traceable standards. Despite the vacature, mercury emissions regulations in the future will require NIST traceable calibration standards, and EPA does not want to interrupt the effort towards developing NIST traceability protocols. The traceability procedures will be defined by EPA. An initial draft traceability protocol was issued by EPA in May 2007 for comment. In August 2007, EPA issued a conceptual interim traceability protocol for elemental mercury calibrators. The protocol is based on the actual analysis of the output of each calibration unit at several concentration levels ranging initially from about 2-40 {micro}g/m{sup 3} elemental mercury, and in the future down to 0.2 {micro}g/m{sup 3}, and this analysis will be directly traceable to analyses by NIST. The EPA traceability protocol document is divided into two separate sections. The first deals with the qualification of calibrator models by the vendors for use in mercury CEM calibration. The second describes the procedure that the vendors must use to certify the calibrators that meet the qualification specifications. The NIST traceable certification is performance based, traceable to analysis using isotope dilution inductively coupled plasma

  16. MODELING MERCURY CONTROL WITH POWDERED ACTIVATED CARBON

    Science.gov (United States)

    The paper presents a mathematical model of total mercury removed from the flue gas at coal-fired plants equipped with powdered activated carbon (PAC) injection for Mercury control. The developed algorithms account for mercury removal by both existing equipment and an added PAC in...

  17. Plain formation on Mercury: tectonic implications

    International Nuclear Information System (INIS)

    Thomas, P.

    1980-01-01

    Four major plain units, plus intermediates, are distinguished on Mercury. The chronologic relationships between these plains indicate that plains formation was a permanent process on Mercury. Their location and morphology seem to indicate a possible volcanic origin for these plains. The relationships between tectonism and volcanism seems to indicate the global contraction is not the only tectonic process on Mercury. (Auth.)

  18. 21 CFR 872.3700 - Dental mercury.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Dental mercury. 872.3700 Section 872.3700 Food and... DENTAL DEVICES Prosthetic Devices § 872.3700 Dental mercury. (a) Identification. Dental mercury is a... dental cavity or a broken tooth. (b) Classification. Class I. ...

  19. Quarter 9 Mercury information clearinghouse final report

    Energy Technology Data Exchange (ETDEWEB)

    Laudal, D.L.; Miller, S.; Pflughoeft-Hassett, D.; Ralston, N.; Dunham, G.; Weber, G.

    2005-12-15

    The Canadian Electricity Association (CEA) identified a need and contracted the Energy & Environmental Research Center (EERC) to create and maintain an information clearinghouse on global research and development activities related to mercury emissions from coal-fired electric utilities. A total of eight reports were completed and are summarized and updated in this final CEA quarterly report. Selected topics were discussed in detail in each quarterly report. Issues related to mercury from coal-fired utilities include the general areas of measurement, control, policy, and transformations. Specific topics that have been addressed in previous quarterly reports include the following: Quarterly 1 - Sorbent Control Technologies for Mercury Control; Quarterly 2 - Mercury Measurement; Quarterly 3 - Advanced and Developmental Mercury Control Technologies; Quarterly 4 - Prerelease of Mercury from Coal Combustion By-Products; Quarterly 5 - Mercury Fundamentals; Quarterly 6 - Mercury Control Field Demonstrations; Quarterly 7 - Mercury Regulations in the United States: Federal and State; and Quarterly 8 - Commercialization Aspects of Sorbent Injection Technologies in Canada. In this last of nine quarterly reports, an update of these mercury issues is presented that includes a summary of each topic, with recent information pertinent to advances made since the quarterly reports were originally presented. In addition to a comprehensive update of previous mercury-related topics, a review of results from the CEA Mercury Program is provided. 86 refs., 11 figs., 8 tabs.

  20. 40 CFR 721.10068 - Elemental mercury.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Elemental mercury. 721.10068 Section... Substances § 721.10068 Elemental mercury. (a) Definitions. The definitions in § 721.3 apply to this section... elemental mercury (CAS. No. 7439-97-6) is subject to reporting under this section for the significant new...

  1. Mercury bioaccumulation in the Mediterranean

    Directory of Open Access Journals (Sweden)

    Cinnirella S.

    2013-04-01

    Full Text Available This study details mercury pollution within the food chain of the Mediterranean by analysing the most comprehensive mercury dataset available for biota and water measurements. In this study we computed a bioaccumulation factor (BAF for datasets in the existing mercury-related scientific literature, in on-going programs, and in past measurement campaigns. Preliminary results indicate a major lack of information, making the outcome of any assessment very uncertain. Importantly, not all marine eco-regions are (or have ever been covered by measurement campaigns. Most lacking is information associated with the South-Eastern part of the Mediterranean, and in several eco-regions it is still impossible to reconstruct a trophic net, as the required species were not accounted for when mercury measurements were taken. The datasets also have additional temporal sampling problems, as species were often not sampled systematically (but only sporadically during any given sampling period. Moreover, datasets composed of mercury concentrations in water also suffer from similar geographic limitations, as they are concentrated in the North-Western Mediterranean. Despite these concerns, we found a very clear bioaccumulation trend in 1999, the only year where comprehensive information on both methylmercury concentrations in water and biota was available.

  2. Technology Evaluations Related to Mercury, Technetium, and Chloride in Treatment of Wastes at the Idaho Nuclear Technology and Engineering Center of the Idaho National Engineering and Environmental Laboratory

    International Nuclear Information System (INIS)

    Barnes, C.M.; Taylor, D.D.; Ashworth, S.C.; Bosley, J.B.; Haefner, D.R.

    1999-01-01

    The Idaho High-Level Waste and Facility Disposition Environmental Impact Statement defines alternative for treating and disposing of wastes stored at the Idaho Nuclear Technology and Engineering Center. Development is required for several technologies under consideration for treatment of these wastes. This report contains evaluations of whether specific treatment is needed and if so, by what methods, to remove mercury, technetium, and chlorides in proposed Environmental Impact Statement treatment processes. The evaluations of mercury include a review of regulatory requirements that would apply to mercury wastes in separations processes, an evaluation of the sensitivity of mercury flowrates and concentrations to changes in separations processing schemes and conditions, test results from laboratory-scale experiments of precipitation of mercury by sulfide precipitation agents from the TRUEX carbonate wash effluent, and evaluations of methods to remove mercury from New Waste Calcining Facility liquid and gaseous streams. The evaluation of technetium relates to the need for technetium removal and alternative methods to remove technetium from streams in separations processes. The need for removal of chlorides from New Waste Calcining Facility scrub solution is also evaluated

  3. Technology Evaluations Related to Mercury, Technetium, and Chloride in Treatment of Wastes at the Idaho Nuclear Technology and Engineering Center of the Idaho National Engineering and Environmental Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    C. M. Barnes; D. D. Taylor; S. C. Ashworth; J. B. Bosley; D. R. Haefner

    1999-10-01

    The Idaho High-Level Waste and Facility Disposition Environmental Impact Statement defines alternative for treating and disposing of wastes stored at the Idaho Nuclear Technology and Engineering Center. Development is required for several technologies under consideration for treatment of these wastes. This report contains evaluations of whether specific treatment is needed and if so, by what methods, to remove mercury, technetium, and chlorides in proposed Environmental Impact Statement treatment processes. The evaluations of mercury include a review of regulatory requirements that would apply to mercury wastes in separations processes, an evaluation of the sensitivity of mercury flowrates and concentrations to changes in separations processing schemes and conditions, test results from laboratory-scale experiments of precipitation of mercury by sulfide precipitation agents from the TRUEX carbonate wash effluent, and evaluations of methods to remove mercury from New Waste Calcining Facility liquid and gaseous streams. The evaluation of technetium relates to the need for technetium removal and alternative methods to remove technetium from streams in separations processes. The need for removal of chlorides from New Waste Calcining Facility scrub solution is also evaluated.

  4. Influence of Water Salinity on Air Purification from Hydrogen Sulfide

    Directory of Open Access Journals (Sweden)

    Leybovych L.I.

    2015-12-01

    Full Text Available Mathematical modeling of «sliding» water drop motion in the air flow was performed in software package FlowVision. The result of mathematical modeling of water motion in a droplet with diameter 100 microns at the «sliding» velocity of 15 m/s is shown. It is established that hydrogen sulfide oxidation occurs at the surface of phases contact. The schematic diagram of the experimental setup for studying air purification from hydrogen sulfide is shown. The results of the experimental research of hydrogen sulfide oxidation by tap and distilled water are presented. The dependence determining the share of hydrogen sulfide oxidized at the surface of phases contact from the dimensionless initial concentration of hydrogen sulfide in the air has been obtained.

  5. Sulindac Sulfide, but Not Sulindac Sulfone, Inhibits Colorectal Cancer Growth

    Directory of Open Access Journals (Sweden)

    Christopher S. Williams

    1999-06-01

    Full Text Available Sulindac sulfide, a metabolite of the nonsteroidal antiinflammatory drug (NSAID sulindac sulfoxide, is effective at reducing tumor burden in both familial adenomatous polyposis patients and in animals with colorectal cancer. Another sulindac sulfoxide metabolite, sulindac sulfone, has been reported to have antitumor properties without inhibiting cyclooxygenase activity. Here we report the effect of sulindac sulfone treatment on the growth of colorectal carcinoma cells. We observed that sulindac sulfide or sulfone treatment of HCA-7 cells led to inhibition of prostaglandin E2 production. Both sulindac sulfide and sulfone inhibited HCA-7 and HCT-116 cell growth in vitro. Sulindac sulfone had no effect on the growth of either HCA-7 or HCT-116 xenografts, whereas the sulfide derivative inhibited HCA-7 growth in vivo. Both sulindac sulfide and sulfone inhibited colon carcinoma cell growth and prostaglandin production in vitro, but sulindac sulfone had no effect on the growth of colon cancer cell xenografts in nude mice.

  6. Oxidation and Precipitation of Sulfide in Sewer Networks

    DEFF Research Database (Denmark)

    Nielsen, A. H.

    risks and corrosion of concrete and metals. Most of the problems relate to the buildup of hydrogen sulfide in the atmosphere of sewer networks. In this respect, the processes of the sulfur cycle are of fundamental importance in ultimately determining the extent of such problems. This study focused...... calibrated and validated against field data. In the extension to the WATS model, sulfur transformations were described by six processes: 1. Sulfide production taking place in the biofilm and sediments covering the permanently wetted sewer walls; 2. Biological sulfide oxidation in the permanently wetted...... to the sewer atmosphere, potentially resulting in concrete corrosion. The extended WATS model represents a major improvement over previously developed models for prediction of sulfide buildup in sewer networks. Compared to such models, the major processes governing sulfide buildup in sewer networks...

  7. Kinetic Spectrophotometric Determination of Trace Amounts of Sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Barzegar, Mohsen [Tarbiat Modarres University, Tehran (Iran, Islamic Republic of); Jabbari, Ali [K. N. Toosi University, Tehran (Iran, Islamic Republic of); Esmaeili, Majid [Razi University, Kermanshah (Iran, Islamic Republic of)

    2003-09-15

    A method for the determination of trace amount of sulfide based on the addition reaction of sulfide with methyl green at pH 7.5 and 25 .deg. C is described. The reaction is monitored spectrophotometrically by measuring the decrease in absorbance of the dyestuff at 637 nm by the initial rate and fixed time method. The calibration graph is linear in the range 30-1200 ppb. The theoretical limit of detection was 0.014 ppm. Seven replicate analysis of a sample solution containing 0.70 ppm sulfide gave a relative standard deviation of 1.5%. The interfering effects of various ions on sulfide determination have been reported and procedures for removal of interference have been described. The proposed method was applied successfully to the determination of sulfide in tap and wastewater samples.

  8. Kinetic Spectrophotometric Determination of Trace Amounts of Sulfide

    International Nuclear Information System (INIS)

    Barzegar, Mohsen; Jabbari, Ali; Esmaeili, Majid

    2003-01-01

    A method for the determination of trace amount of sulfide based on the addition reaction of sulfide with methyl green at pH 7.5 and 25 .deg. C is described. The reaction is monitored spectrophotometrically by measuring the decrease in absorbance of the dyestuff at 637 nm by the initial rate and fixed time method. The calibration graph is linear in the range 30-1200 ppb. The theoretical limit of detection was 0.014 ppm. Seven replicate analysis of a sample solution containing 0.70 ppm sulfide gave a relative standard deviation of 1.5%. The interfering effects of various ions on sulfide determination have been reported and procedures for removal of interference have been described. The proposed method was applied successfully to the determination of sulfide in tap and wastewater samples

  9. Anoxic sulfide biooxidation using nitrite as electron acceptor

    International Nuclear Information System (INIS)

    Mahmood, Qaisar; Zheng Ping; Cai Jing; Wu Donglei; Hu, Baolan; Li Jinye

    2007-01-01

    Biotechnology can be used to assess the well being of ecosystems, transform pollutants into benign substances, generate biodegradable materials from renewable sources, and develop environmentally safe manufacturing and disposal processes. Simultaneous elimination of sulfide and nitrite from synthetic wastewaters was investigated using a bioreactor. A laboratory scale anoxic sulfide-oxidizing (ASO) reactor was operated for 135 days to evaluate the potential for volumetric loading rates, effect of hydraulic retention time (HRT) and substrate concentration on the process performance. The maximal sulfide and nitrite removal rates were achieved to be 13.82 and 16.311 kg/(m 3 day), respectively, at 0.10 day HRT. The process can endure high sulfide concentrations, as the sulfide removal percentage always remained higher than 88.97% with influent concentration up to 1920 mg/L. Incomplete sulfide oxidation took place due to lower consumed nitrite to sulfide ratios of 0.93. It also tolerated high nitrite concentration up to 2265.25 mg/L. The potential achieved by decreasing HRT at fixed substrate concentration is higher than that by increasing substrate concentration at fixed HRT. The process can bear short HRT of 0.10 day but careful operation is needed. Nitrite conversion was more sensitive to HRT than sulfide conversion when HRT was decreased from 1.50 to 0.08 day. Stoichiometric analyses and results of batch experiments show that major part of sulfide (89-90%) was reduced by nitrite while some autooxidation (10-11%) was resulted from presence of small quantities of dissolved oxygen in the influent wastewater. There was ammonia amassing in considerably high amounts in the bioreactor when the influent nitrite concentration reached above 2265.25 mg/L. High ammonia concentrations (200-550 mg/L) in the bioreactor contributed towards the overall inhibition of the process. Present biotechnology exhibits practical value with a high potential for simultaneous removal of nitrite

  10. Control of mercury emissions: policies, technologies, and future trends

    OpenAIRE

    Rhee, Seung-Whee

    2015-01-01

    Seung-Whee Rhee Department of Environmental Engineering, Kyonggi University, Suwon, Republic of Korea Abstract: Owing to the Minamata Convention on Mercury and the Global Mercury Partnership, policies and regulations on mercury management in advanced countries were intensified by a mercury phaseout program in the mercury control strategy. In developing countries, the legislative or regulatory frameworks on mercury emissions are not established specifically, but mercury management is designed...

  11. Sodium Velocity Maps on Mercury

    Science.gov (United States)

    Potter, A. E.; Killen, R. M.

    2011-01-01

    The objective of the current work was to measure two-dimensional maps of sodium velocities on the Mercury surface and examine the maps for evidence of sources or sinks of sodium on the surface. The McMath-Pierce Solar Telescope and the Stellar Spectrograph were used to measure Mercury spectra that were sampled at 7 milliAngstrom intervals. Observations were made each day during the period October 5-9, 2010. The dawn terminator was in view during that time. The velocity shift of the centroid of the Mercury emission line was measured relative to the solar sodium Fraunhofer line corrected for radial velocity of the Earth. The difference between the observed and calculated velocity shift was taken to be the velocity vector of the sodium relative to Earth. For each position of the spectrograph slit, a line of velocities across the planet was measured. Then, the spectrograph slit was stepped over the surface of Mercury at 1 arc second intervals. The position of Mercury was stabilized by an adaptive optics system. The collection of lines were assembled into an images of surface reflection, sodium emission intensities, and Earthward velocities over the surface of Mercury. The velocity map shows patches of higher velocity in the southern hemisphere, suggesting the existence of sodium sources there. The peak earthward velocity occurs in the equatorial region, and extends to the terminator. Since this was a dawn terminator, this might be an indication of dawn evaporation of sodium. Leblanc et al. (2008) have published a velocity map that is similar.

  12. Carbon steel protection in G.S. (Girlder sulfide) plants. Pressure influence on iron sulfide scales formation. Pt. 5

    International Nuclear Information System (INIS)

    Delfino, C.A.; Lires, O.A.; Rojo, E.A.

    1987-01-01

    In order to protect carbon steel towers and piping of Girlder sulfide (G.S.) experimental heavy water plants against corrosion produced by the action of aqueous solutions of hydrogen sulfide, a method, previously published, was developed. Carbon steel, exposed to saturated aqueous solutions of hydrogen sulfide, forms iron sulfide scales. In oxygen free solutions evolution of corrosion follows the sequence: mackinawite → cubic ferrous sulfide → troilite → pyrrotite → pyrite. Scales formed by pyrrotite-pyrite or pyrite are the most protective layers (these are obtained at 130 deg C, 2MPa, for periods of 14 days). Experiments, at 125 deg C and periods of 10-25 days, were performed in two different ways: 1- constant pressure operations at 0.5 and 1.1 MPa. 2- variable pressure operation between 0.3-1 MPa. In all cases pyrrotite-pyrite scales were obtained. (Author) [es

  13. Intake of mercury through fish consumption

    International Nuclear Information System (INIS)

    Sarmani, S.B.; Kiprawi, A.Z.; Ismail, R.B.; Hassan, R.B.; Wood, A.K.; Rahman, S.A.

    1995-01-01

    Fish has been known as a source of non-occupational mercury exposure to fish consuming population groups, and this is shown by the high hair mercury levels. In this study, hair samples collected from fishermen and their families, and commercial marine fishes were analyzed for mercury and methylmercury by neutron activation and gas chromatography. The results showed a correlation between hair mercury levels and fish consumption patterns. The levels of mercury found in this study were similar to those reported by other workers for fish consuming population groups worldwide. (author)

  14. Coal fired flue gas mercury emission controls

    CERN Document Server

    Wu, Jiang; Pan, Weiguo; Pan, Weiping

    2015-01-01

    Mercury (Hg) is one of the most toxic heavy metals, harmful to both the environment and human health. Hg is released into the atmosphere from natural and anthropogenic sources and its emission control has caused much concern. This book introduces readers to Hg pollution from natural and anthropogenic sources and systematically describes coal-fired flue gas mercury emission control in industry, especially from coal-fired power stations. Mercury emission control theory and experimental research are demonstrated, including how elemental mercury is oxidized into oxidized mercury and the effect of

  15. Marine biogeochemistry of mercury

    International Nuclear Information System (INIS)

    Gill, G.A.

    1986-01-01

    Noncontaminating sample collection and handling procedures and accurate and sensitive analysis methods were developed to measure sub-picomolar Hg concentrations in seawater. Reliable and diagnostic oceanographic Hg distributions were obtained, permitting major processes governing the marine biogeochemistry of Hg to be identified. Mercury concentrations in the northwest Atlantic, central Pacific, southeast Pacific, and Tasman Sea ranged from 0.5 to 12 pM. Vertical Hg distributions often exhibited a maximum within or near the main thermocline. At similar depths, Hg concentrations in the northwest Atlantic Ocean were elevated compared to the N. Pacific Ocean. This pattern appears to result from a combination of enhanced supply of Hg to the northwest Atlantic by rainfall and scavenging removal along deep water circulation pathways. These observations are supported by geochemical steady-state box modelling which predicts a relatively short mean residence time for Hg in the oceans; demonstrating the reactive nature of Hg in seawater and precluding significant involvement in nutrient-type recyclic. Evidence for the rapid removal of Hg from seawater was obtained at two locations. Surface seawater Hg measurements along 160 0 W (20 0 N to 20 0 S) showed a depression in the equatorial upwelling area which correlated well with the transect region exhibiting low 234 Th/ 238 U activity ratios. This relationship implies that Hg will be scavenged and removed from surface seawater in biologically productive oceanic zones. Further, a broad minimum in the vertical distribution of Hg was observed to coincide with the intense oxygen minimum zone in the water column in coastal waters off Peru

  16. Mercury accumulation plant Cyrtomium macrophyllum and its potential for phytoremediation of mercury polluted sites.

    Science.gov (United States)

    Xun, Yu; Feng, Liu; Li, Youdan; Dong, Haochen

    2017-12-01

    Cyrtomium macrophyllum naturally grown in 225.73 mg kg -1 of soil mercury in mining area was found to be a potential mercury accumulator plant with the translocation factor of 2.62 and the high mercury concentration of 36.44 mg kg -1 accumulated in its aerial parts. Pot experiments indicated that Cyrtomium macrophyllum could even grow in 500 mg kg -1 of soil mercury with observed inhibition on growth but no obvious toxic effects, and showed excellent mercury accumulation and translocation abilities with both translocation and bioconcentration factors greater than 1 when exposed to 200 mg kg -1 and lower soil mercury, indicating that it could be considered as a great mercury accumulating species. Furthermore, the leaf tissue of Cyrtomium macrophyllum showed high resistance to mercury stress because of both the increased superoxide dismutase activity and the accumulation of glutathione and proline induced by mercury stress, which favorited mercury translocation from the roots to the aerial parts, revealing the possible reason for Cyrtomium macrophyllum to tolerate high concentration of soil mercury. In sum, due to its excellent mercury accumulation and translocation abilities as well as its high resistance to mercury stress, the use of Cyrtomium macrophyllum should be a promising approach to remediating mercury polluted soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Global Mercury Pathways in the Arctic Ecosystem

    Science.gov (United States)

    Lahoutifard, N.; Lean, D.

    2003-12-01

    The sudden depletions of atmospheric mercury which occur during the Arctic spring are believed to involve oxidation of gaseous elemental mercury, Hg(0), rendering it less volatile and more soluble. The Hg(II) oxidation product(s) are more susceptible to deposition, consistent with the observation of dramatic increases in snow mercury levels during depletion events. Temporal correlations with ozone depletion events and the proliferation of BrO radicals support the hypothesis that oxidation of Hg(0) occurs in the gas phase and results in its conversion to RGM (Reactive Gaseous Mercury). The mechanisms of Hg(0) oxidation and particularly Hg(II) reduction are as yet unproven. In order to evaluate the feasibility of proposed chemical processes involving mercury in the Arctic atmosphere and its pathway after deposition on the snow from the air, we investigated mercury speciation in air and snow pack at Resolute, Nunavut, Canada (latitude 75° N) prior to and during snow melt during spring 2003. Quantitative, real-time information on emission, air transport and deposition were combined with experimental studies of the distribution and concentrations of different mercury species, methyl mercury, anions, total organic carbon and total inorganic carbon in snow samples. The effect of solar radiation and photoreductants on mercury in snow samples was also investigated. In this work, we quantify mercury removed from the air, and deposited on the snow and the transformation to inorganic and methyl mercury.

  18. Mercury emission monitoring on municipal waste combustion

    International Nuclear Information System (INIS)

    Braun, H.; Gerig, A.

    1991-01-01

    In waste incineration, mercury is the only heavy metal to be released as a gas, mostly as mercury(II) chloride, because of its high volatility. Continuous emission monitoring is possible only when mercury occurs in its elemental form. This paper reports on various possibilities of converting Hg(II) into Hg(0) that has been studied and tested on a laboratory scale and in the TAMARA refuse incineration pilot facility. Continuous mercury emission measurement appears to be possible, provided mercury is converted in the flue gas condensate precipitated. The measuring results obtained on two municipal solid waste and on one sewage treatment sludge incineration plants show that the mercury monitor is a highly sensitive and selective continuously working instrument for mercury emission monitoring

  19. Genetic effects of organic mercury compounds

    Energy Technology Data Exchange (ETDEWEB)

    Ramel, C

    1967-01-01

    Organic mercury compounds have a c-mitotic effect on plant cells that cause polyploidi. Studies were performed on Allium root cells. These investigations involved methyl mercury dicyandiamide, methyl mercury hydroxide, and phenyl mercury hydroxide. The lowest concentration necessary for a cytologically observable effect was about 0.05 ppM Hg for the methyl compounds. For the phenyl compound, the value was lower. Experiments were performed on Drosophila melanogaster. The question was whether the mercury would reach the gonads. Experimental data with mercury treated larvae indicated a chromosome disjunction. Data indicated a preferential segregation at the meiotic division might be involved. Experiments are being performed on mice inbred (CBA) in order to investigate teratogenic effects and dominant lethality caused by organic mercury compounds. The mutagenic effects of these compounds are studied on Neurospora Drosophila. No conclusive data is now available.

  20. Mercury risk in poultry in the Wanshan Mercury Mine, China

    International Nuclear Information System (INIS)

    Yin, Runsheng; Zhang, Wei; Sun, Guangyi; Feng, Zhaohui; Hurley, James P.; Yang, Liyuan; Shang, Lihai; Feng, Xinbin

    2017-01-01

    In this study, total mercury (THg) and methylmercury (MeHg) concentrations in muscles (leg and breast), organs (intestine, heart, stomach, liver) and blood were investigated for backyard chickens, ducks and geese of the Wanshan Mercury Mine, China. THg in poultry meat products range from 7.9 to 3917.1 ng/g, most of which exceeded the Chinese national standard limit for THg in meat (50 ng/g). Elevated MeHg concentrations (0.4–62.8 ng/g) were also observed in meat products, suggesting that poultry meat can be an important human MeHg exposure source. Ducks and geese showed higher Hg levels than chickens. For all poultry species, the highest Hg concentrations were observed in liver (THg: 23.2–3917.1 ng/g; MeHg: 7.1–62.8 ng/g) and blood (THg: 12.3–338.0 ng/g; MeHg: 1.4–17.6 ng/g). We estimated the Hg burdens in chickens (THg: 15.3–238.1 μg; MeHg: 2.2–15.6 μg), ducks (THg: 15.3–238.1 μg; MeHg: 3.5–14.7 μg) and geese (THg: 83.8–93.4 μg; MeHg: 15.4–29.7 μg). To not exceed the daily intake limit for THg (34.2 μg/day) and MeHg (6 μg/day), we suggested that the maximum amount (g) for chicken leg, breast, heart, stomach, intestine, liver, and blood should be 1384, 1498, 2315, 1214, 1081, 257, and 717, respectively; the maximum amount (g) for duck leg, breast, heart, stomach, intestine, liver, and blood should be 750, 1041, 986, 858, 752, 134, and 573, respectively; and the maximum amount (g) for goose leg, breast, heart, stomach, intestine, liver, and blood should be 941, 1051, 1040, 1131, 964, 137, and 562, respectively. - Highlights: • Elevated mercury levels were observed in poultry from Wanshan Mercury Mine, China. • Ducks and geese showed higher mercury levels than chickens. • Liver and blood showed the highest mercury levels. • Poultry can be an important dietary Hg exposure source for local residents. - High levels of Hg associated with poultry surrounding the Wanshan Mercury Mine pose a great risk of Hg exposure to

  1. Occupational exposure to hydrogen sulfide: management of hydrogen sulfide exposure victims (Preprint No. SA-5)

    International Nuclear Information System (INIS)

    Srivastava, P.P.

    1989-04-01

    National Institute of Occupational Safety and Health, U.S.A. has listed 73 industries with potential exposure to hydrogen sulphide. Though the toxicity of hydrogen sulfide is known to mankind since the beginning of seventeenth century the exact mode of its toxicity and effective therapeutic regimen remains unclear as yet. This paper presents current thoughts on the toxicity of this substance and a discussion on the role of various antidotes used in H 2 S poisoning. (autho r)

  2. Azo dye decolorization assisted by chemical and biogenic sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Prato-Garcia, Dorian [Laboratory for Research on Advanced Processes for Water Treatment, Unidad Académica Juriquilla, Instituto de Ingeniería, Universidad Nacional Autónoma de México, Blvd. Juriquilla 3001, Querétaro 76230 (Mexico); Cervantes, Francisco J. [División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa de San José 2055, San Luis Potosí 78216 (Mexico); Buitrón, Germán, E-mail: gbuitronm@ii.unam.mx [Laboratory for Research on Advanced Processes for Water Treatment, Unidad Académica Juriquilla, Instituto de Ingeniería, Universidad Nacional Autónoma de México, Blvd. Juriquilla 3001, Querétaro 76230 (Mexico)

    2013-04-15

    Highlights: ► Azo dyes were reduced efficiently by chemical and biogenic sulfide. ► Biogenic sulfide was more efficient than chemical sulfide. ► There was no competition between dyes and sulfate for reducing equivalents. ► Aromatic amines barely affected the sulfate-reducing process. -- Abstract: The effectiveness of chemical and biogenic sulfide in decolorizing three sulfonated azo dyes and the robustness of a sulfate-reducing process for simultaneous decolorization and sulfate removal were evaluated. The results demonstrated that decolorization of azo dyes assisted by chemical sulfide and anthraquinone-2,6-disulfonate (AQDS) was effective. In the absence of AQDS, biogenic sulfide was more efficient than chemical sulfide for decolorizing the azo dyes. The performance of sulfate-reducing bacteria in attached-growth sequencing batch reactors suggested the absence of competition between the studied azo dyes and the sulfate-reducing process for the reducing equivalents. Additionally, the presence of chemical reduction by-products had an almost negligible effect on the sulfate removal rate, which was nearly constant (94%) after azo dye injection.

  3. Simultaneous removal of sulfide, nitrate and acetate: Kinetic modeling

    Energy Technology Data Exchange (ETDEWEB)

    Wang Aijie, E-mail: waj0578@hit.edu.cn [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), Harbin 150090 (China); Liu Chunshuang; Ren Nanqi; Han Hongjun [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), Harbin 150090 (China); Lee Duujong [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), Harbin 150090 (China); Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan (China)

    2010-06-15

    Biological removal of sulfide, nitrate and chemical oxygen demand (COD) simultaneously from industrial wastewaters to elementary sulfur (S{sup 0}), N{sub 2}, and CO{sub 2}, or named the denitrifying sulfide (DSR) process, is a cost effective and environmentally friendly treatment process for high strength sulfide and nitrate laden organic wastewater. Kinetic model for the DSR process was established for the first time on the basis of Activated Sludge Model No. 1 (ASM1). The DSR experiments were conducted at influent sulfide concentrations of 200-800 mg/L, whose results calibrate the model parameters. The model correlates well with the DSR process dynamics. By introducing the switch function and the inhibition function, the competition between autotrophic and heterotrophic denitrifiers is quantitatively described and the degree of inhibition of sulfide on heterotrophic denitrifiers is realized. The model output indicates that the DSR reactor can work well at 0.5 < C/S < 3.0 with influent sulfide concentration of 400-1000 mg/L. At >1000 mg/L influent sulfide, however, the DSR system will break down.

  4. Behaviour of mercury compounds in soil

    Energy Technology Data Exchange (ETDEWEB)

    Booer, J R

    1944-01-01

    The uses of inorganic compounds of mercury for the control of plant pests is reviewed, and a summary of the relevant chemical and physical properties of the compounds concerned is given. On chemical evidence a working hypothesis is propounded showing that all compounds may be expected to decompose into metallic mercury. A pot technique is described by means of which a correlation can be obtained between the effective mercury content of a given soil sample and the rate of growth of wheat seedlings. The mathematical treatment of the results is described, and the validity of the pot technique is verified by statistical analysis of results. Using the pot technqiue it is shown that volatilization losses are insignificant but that mercury is slowly rendered ineffective by the formation of mercuric sulphide. The effect of sulphur-reducing bacteria is considered and the influence of Vibrio desulphuricans on mercury is studied in detail. Experimental evidence obtained by the pot technique is produced to show that mercurous chloride slowly decomposes in the soil giving mercury and mercuric chloride, mercuric chloride rapidly decomposes into mercury and mercurous chloride, and other inorganic compounds decompose directly into mercury. The working hypothesis is substantiated in all major aspects. The uses and properties of the organo-mercury compounds are then discussed. Type compounds selected are ethyl mercury phosphate, phenyl mercury acetate and methoxyethyl mercury acetate. Using the pot technique it is shown that the formation of organo-mercury clays takes place and that these clays decompose giving metallic mercury. A mechanism is suggested.

  5. Mercury in the environment : a review

    International Nuclear Information System (INIS)

    Goodarzi, F.

    2000-01-01

    Both geogenic and anthropogenic sources are responsible for the input of mercury into the environment. However, mercury comes mostly from geogenic sources and is found naturally in air, water and soil. Crustal degassing results in emission of mercury into the atmosphere. Mercury in water and soil is due mostly to input from sedimentary rocks. Mercury in lake sediments is related mainly to input by country rock and anthropogenic activities such as agriculture. The mercury content of coal is similar to or less than the amount found in the earths crust. Natural charcoal is also able to capture mercury at low temperature combustion. The amount of mercury emitted from the stack of coal-fired power plants is related to the nature of the milled coal and its mineralogical and elemental content. Mercury emissions originating from the combustion of coal from electric utility power plants are considered to be among the greatest contributors to global mercury air emissions. In order to quantify the impact the electric power industry has on the environment, information regarding mercury concentrations in coal and their speciation is needed. For this reason the author examined the behaviour of mercury in three coal samples ashed at increasing temperatures. Mercury removal from coal-fired power plants ranges from 10 to 50 per cent by fabric filters and 20 to 95 per cent by FGD systems. This data will help in regulating emissions of hazardous air pollutants from electric utility steam generating units and will potentially provide insight into the industry's contribution to the global mercury burden. 50 refs

  6. Dissolved gaseous mercury formation and mercury volatilization in intertidal sediments.

    Science.gov (United States)

    Cesário, Rute; Poissant, Laurier; Pilote, Martin; O'Driscoll, Nelson J; Mota, Ana M; Canário, João

    2017-12-15

    Intertidal sediments of Tagus estuary regularly experiences complex redistribution due to tidal forcing, which affects the cycling of mercury (Hg) between sediments and the water column. This study quantifies total mercury (Hg) and methylmercury (MMHg) concentrations and fluxes in a flooded mudflat as well as the effects on water-level fluctuations on the air-surface exchange of mercury. A fast increase in dissolved Hg and MMHg concentrations was observed in overlying water in the first 10min of inundation and corresponded to a decrease in pore waters, suggesting a rapid export of Hg and MMHg from sediments to the water column. Estimations of daily advective transport exceeded the predicted diffusive fluxes by 5 orders of magnitude. A fast increase in dissolved gaseous mercury (DGM) concentration was also observed in the first 20-30min of inundation (maximum of 40pg L -1 ). Suspended particulate matter (SPM) concentrations were inversely correlated with DGM concentrations. Dissolved Hg variation suggested that biotic DGM production in pore waters is a significant factor in addition to the photochemical reduction of Hg. Mercury volatilization (ranged from 1.1 to 3.3ngm -2 h -1 ; average of 2.1ngm -2 h -1 ) and DGM production exhibited the same pattern with no significant time-lag suggesting a fast release of the produced DGM. These results indicate that Hg sediment/water exchanges in the physical dominated estuaries can be underestimated when the tidal effect is not considered. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Mercury erosion experiments for spallation target system

    International Nuclear Information System (INIS)

    Kinoshita, Hidetaka; Kaminaga, Masanori; Haga, Katsuhiro; Hino, Ryutaro

    2003-01-01

    The Japan Atomic Energy Research Institute (JAERI) and the High Energy Accelerator Research Organization (KEK) are promoting a plan to construct the spallation neutron source at the Tokai Research Establishment, JAERI, under the High-Intensity Proton Accelerator Project (J-PARC). A mercury circulation system has been designed so as to supply mercury to the target stably under the rated flow rate of 41 m 3 /hr. Then, it was necessary to confirm a mercury pump performance from the viewpoint of making the mercury circulation system feasible, and more, to investigate erosion rate under the mercury flow as well as an amount of mercury remained on the surface after drain from the viewpoints of mechanical strength relating to the lifetime and remote handling of mercury components. The mercury pump performance was tested under the mercury flow conditions by using an experimental gear pump, which had almost the same structure as a practical mercury pump to be expected in the mercury circulation system, and the erosion rates in a mercury pipeline as well as the amount of mercury remained on the surface were also investigated. The discharged flow rates of the experimental gear pump increased linearly with the rotation speed, so that the gear pump would work as the flow meter. Erosion rates obtained under the mercury velocity less than 1.6 m/s was found to be so small that decrease of pipeline wall thickness would be 390 μm after 30-year operation under the rated mercury velocity of 0.7 m/s. For the amount of remaining mercury on the pipeline, remaining rates of weight and volume were estimated at 50.7 g/m 2 and 3.74 Hg-cm 3 /m 2 , respectively. Applying these remaining rates of weight and volume to the mercury target, the remaining mercury was estimated at about 106.5 g and 7.9 cm 3 . Radioactivity of this remaining mercury volume was found to be three-order lower than that of the target casing. (author)

  8. Interactions among sulfide-oxidizing bacteria

    Science.gov (United States)

    Poplawski, R.

    1985-01-01

    The responses of different phototrophic bacteria in a competitive experimental system are studied, one in which primary factors such as H2S or light limited photometabolism. Two different types of bacteria shared one limited source of sulfide under specific conditions of light. The selection of a purple and a green sulfur bacteria and the cyanobacterium was based on their physiological similarity and also on the fact that they occur together in microbial mats. They all share anoxygenic photosynthesis, and are thus probably part of an evolutionary continuum of phototrophic organisms that runs from, strictly anaerobic physiology to the ability of some cyanobacteria to shift between anoxygenic bacterial style photosynthesis and the oxygenic kind typical of eukaryotes.

  9. Eelgrass fairy rings: sulfide as inhibiting agent

    DEFF Research Database (Denmark)

    Borum, Jens; Raun, Ane-Marie Løvendahl; Hasler-Sheetal, Harald

    2014-01-01

    specifically, for the apparent die- off of eelgrass shoots on the inner side of the rings. The fairy rings were up to 15 m in diameter consisting of 0.3- to 1-m-wide zones of sea grass shoots at densities of up to 1,200 shoots m−2 and rooted in an up to 10-cm-thick sediment layer. On the outer side, shoots...... expanded over the bare chalk plates. On the inner side, shoots were smaller, had lower absolute and specific leaf growth, shoot density was lower and the sediment eroded leaving the bare chalk with scattered boulders behind. Sediment organic matter and nutrients and tissue nutrient contents were...... substantial invasion of sulfide from the sediment. neither the clonal growth pattern of eelgrass, sediment burial of shoots, hydrodynamic forcing nor nutrient limitation could explain the ring-shaped pattern. We conclude that the most likely explanation must be found in invasion of eelgrass shoots by toxic...

  10. On the pelletizing of sulfide molybdenite concentrate

    International Nuclear Information System (INIS)

    Palant, A.A.

    2007-01-01

    Investigation results are discussed on the process of pelletizing with the use of various binders (water, syrup, sulfite-alcoholic residue and bentonite) for flotation sulfide molybdenite concentrate (∼84 % MoS 2 ) of the Mongolian deposit. It is established that with the use of syrup rather strong pellets (>300 g/p) of desired size (2-3 mm) can be obtained at a binder flowrate of 1 kg per 100 kg of concentrate. The main advantage of using syrup instead of bentonite lies in the fact that in this instance no depletion of a molybdenum calcine obtained by oxidizing roasting of raw ore takes place due to syrup complete burning out. This affects positively subsequent hydrometallurgical conversion because of decreasing molybdenum losses with waste cakes [ru

  11. Modulated structure calculated for superconducting hydrogen sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Majumdar, Arnab; Tse, John S.; Yao, Yansun [Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, SK (Canada)

    2017-09-11

    Compression of hydrogen sulfide using first principles metadynamics and molecular dynamics calculations revealed a modulated structure with high proton mobility which exhibits a diffraction pattern matching well with experiment. The structure consists of a sublattice of rectangular meandering SH{sup -} chains and molecular-like H{sub 3}S{sup +} stacked alternately in tetragonal and cubic slabs forming a long-period modulation. The novel structure offers a new perspective on the possible origin of the superconductivity at very high temperatures in which the conducting electrons in the SH chains are perturbed by the fluxional motions of the H{sub 3}S resulting in strong electron-phonon coupling. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Mechanism of hydrodenitrogenation on phosphides and sulfides.

    Science.gov (United States)

    Oyama, S Ted; Lee, Yong-Kul

    2005-02-17

    The mechanism of hydrodenitrogenation (HDN) of 2-methylpiperidine was studied over a silica-supported nickel phosphide catalyst (Ni2P/SiO2, Ni/P = 1/2) and a commercial Ni-Mo-S/Al2O3 catalyst in a three-phase trickle-bed reactor operated at 3.1 MPa and 450-600 K. Analysis of the product distribution as a function of contact time indicated that the reaction proceeded in both cases predominantly by a substitution mechanism, with a smaller contribution of an elimination mechanism. Fourier transform infrared spectroscopy (FTIR) of the 2-methylpiperidine indicated that at reaction conditions a piperidinium ion intermediate was formed on both the sulfide and the phosphide. It is concluded that the mechanism of HDN on nickel phosphide is very similar to that on sulfides. The mechanism on the nickel phosphide was also probed by comparing the reactivity of piperidine and several of its derivatives in the presence of 3000 ppm S. The relative elimination rates depended on the structure of the molecules, and followed the sequence: 4-methylpiperidine approximately piperidine > 3-methylpiperidine > 2,6-dimethylpiperidine > 2-methylpiperidine. [Chemical structure: see text] This order of reactivity was not dependent on the number of alpha-H or beta-H atoms in the molecules, ruling out their reaction through a single, simple mechanism. It is likely that the unhindered piperidine molecules reacted by an S(N)2 substitution process and the more hindered 2,6-dimethylpiperidine reacted by an E2 elimination process.

  13. New cyclic sulfides, garlicnins I2, M, N, and O, from Allium sativum.

    Science.gov (United States)

    Nohara, Toshihiro; Ono, Masateru; Nishioka, Naho; Masuda, Fuka; Fujiwara, Yukio; Ikeda, Tsuyoshi; Nakano, Daisuke; Kinjo, Junei

    2018-01-01

    One atypical thiolane-type sulfide, garlicnin I 2 (1), two 3,4-dimethylthiolane-type sulfides, garlicnins M (2) and N (3), and one thiabicyclic-type sulfide, garlicnin O (4), were isolated from the acetone extracts of Chinese garlic bulbs, Allium sativum and their structures were characterized. Hypothetical pathways for the production of the respective sulfides were discussed.

  14. 76 FR 75446 - Amendment of Class E Airspace; Mercury, NV

    Science.gov (United States)

    2011-12-02

    ...-0894; Airspace Docket No. 11-AWP-14] Amendment of Class E Airspace; Mercury, NV AGENCY: Federal... Mercury, Desert Rock Airport, Mercury, NV. Decommissioning of the Mercury Non-Directional Beacon (NDB) at Mercury, Desert Rock Airport has made this action necessary for the safety and management of Instrument...

  15. Touchstones and mercury at Hedeby

    Czech Academy of Sciences Publication Activity Database

    Ježek, Martin; Holub, M.

    2014-01-01

    Roč. 89, č. 1 (2014), s. 193-204 ISSN 0079-4848 Institutional support: RVO:67985912 Keywords : Hedeby * Viking Age * grave goods * touchstone * precious metal * mercury * chemical microanalysis * archaeometallurgy Subject RIV: AC - Archeology, Anthropology, Ethnology Impact factor: 0.278, year: 2014

  16. Venus and Mercury as Planets

    Science.gov (United States)

    1974-01-01

    A general evolutionary history of the solar planetary system is given. The previously observed characteristics of Venus and Mercury (i.e. length of day, solar orbit, temperature) are discussed. The role of the Mariner 10 space probe in gathering scientific information on the two planets is briefly described.

  17. PERCEPTION OF MERCURY RISK INFORMATION

    Science.gov (United States)

    Approximately 8% of American women have blood Mercury levels exceeding the EPA reference dose (a dose below which symptoms would be unlikely). The children of these women are at risk of neurological deficits (lower IQ scores) primarily because of the mother's consumption of conta...

  18. Venus and Mercury as planets

    International Nuclear Information System (INIS)

    1974-01-01

    A general evolutionary history of the solar planetary system is given. The previously observed characteristics of Venus and Mercury (i.e. length of day, solar orbit, temperature) are discussed. The role of the Mariner 10 space probe in gathering scientific information on the two planets is briefly described

  19. A downstream voyage with mercury

    Science.gov (United States)

    Heinz, Gary

    2016-01-01

    Retrospective essay for the Bulletin of Environmental Contamination and Toxicology.As I look back on my paper, “Effects of Low Dietary Levels of Methyl Mercury on Mallard Reproduction,” published in 1974 in the Bulletin of Environmental Contamination and Toxicology, a thought sticks in my mind. I realize just how much my mercury research was not unlike a leaf in a stream, carried this way and that, sometimes stalled in an eddy, restarted, and carried downstream at a pace and path that was not completely under my control. I was hired in 1969 by the Patuxent Wildlife Research Center to study the effects of environmental pollutants on the behavior of wildlife. A colleague was conducting a study on the reproductive effects of methylmercury on mallards (Anas platyrhynchos), and he offered to give me some of the ducklings. I conducted a pilot study, testing how readily ducklings approached a tape-recorded maternal call. Sample sizes were small, but the results suggested that ducklings from mercury-treated parents behaved differently than controls. That’s how I got into mercury research—pretty much by chance.

  20. Optimization of the superconducting phase of hydrogen sulfide

    Science.gov (United States)

    Degtyarenko, N. N.; Masur, E. A.

    2015-12-01

    The electron and phonon spectra, as well as the densities of electron and phonon states of the SH3 phase and the stable orthorhombic structure of hydrogen sulfide SH2, are calculated for the pressure interval 100-225 GPa. It is found that the I4/ mmm phase can be responsible for the superconducting properties of metallic hydrogen sulfide along with the SH3 phase. Sequential stages for obtaining and conservation of the SH2 phase are proposed. The properties of two (SH2 and SH3) superconducting phases of hydrogen sulfide are compared.

  1. Process for scavenging hydrogen sulfide from hydrocarbon gases

    International Nuclear Information System (INIS)

    Fox, I.

    1981-01-01

    A process for scavenging hydrogen sulfide from hydrocarbon gases utilizes iron oxide particles of unique chemical and physical properties. These particles have large surface area, and are comprised substantially of amorphous Fe 2 O 3 containing a crystalline phase of Fe 2 O 3 , Fe 3 O 4 and combinations thereof. In scavenging hydrogen sulfide, the iron oxide particles are suspended in a liquid which enters into intimate mixing contact with hydrocarbon gases; the hydrogen sulfide is reacted at an exceptional rate and only acid-stable reaction products are formed. Thereafter, the sweetened hydrocarbon gases are collected

  2. Sulfidization of an aluminocobaltomolybdenum catalyst using the 35S radioisotope

    International Nuclear Information System (INIS)

    Isagulyants, G.V.; Greish, A.A.; Kogan, V.M.

    1987-01-01

    It has been established that in aluminocobaltomolybdenum catalyst sulfidized with elemental sulfur there are two types of sulfur, free and bound. The maximum amount of bound sulfur in ACM catalyst is 6.6 wt. %, which corresponds to practically complete sulfidation of the ACM catalyst. In the presence of hydrogen an equilibrium distribution of bound sulfur is achieved in a granule of ACM catalyst irrespective of the temperature of sulfidation. In a nitrogen atmosphere it is primarily the surface layers of the catalyst that are sulfured

  3. Sulfide Oxidation in the Anoxic Black-Sea Chemocline

    DEFF Research Database (Denmark)

    JØRGENSEN, BB; FOSSING, H.; WIRSEN, CO

    1991-01-01

    per day, occurred in anoxic water at the top of the sulfide zone concurrent with the highest rates of dark CO2 assimilation. The main soluble oxidized products of sulfide were thiosulfate (68-82%) and sulfate. Indirect evidence was presented for the formation of elemental sulfur which accumulated...... that the measured H2S oxidation rates were 4-fold higher than could be explained by the downward flux of organic carbon and too high to balance the availability of electron acceptors such as oxidized iron or manganese. A nitrate maximum at the lower boundary of the O2 zone did not extend down to the sulfide zone....

  4. Thermoelectric properties of non-stoichiometric lanthanum sulfides

    International Nuclear Information System (INIS)

    Shapiro, E.; Danielson, L.R.

    1983-01-01

    The lanthanum sulfides are promising candidate materials for high-efficiency thermoelectric applications at temperatures up to 1300 0 C. The nonstoichiometric lanthanum sulfides (LaS /SUB x/ , where 1.33 2 //rho/ can be chosen. The thermal conductivity remains approximately constant with stoichiometry, so a material with an optimum value of α 2 //rho/ should possess the optimum figure-of-merit. Data for the Seebeck coefficient and electrical resistivity of non-stoichiometric lanthanum sulfides is presented, together with structural properties of these materials

  5. Denitrifying sulfide removal process on high-salinity wastewaters.

    Science.gov (United States)

    Liu, Chunshuang; Zhao, Chaocheng; Wang, Aijie; Guo, Yadong; Lee, Duu-Jong

    2015-08-01

    Denitrifying sulfide removal (DSR) process comprising both heterotrophic and autotrophic denitrifiers can simultaneously convert nitrate, sulfide, and acetate into nitrogen gas, elemental sulfur (S(0)), and carbon dioxide, respectively. Sulfide- and nitrate-laden wastewaters at 2-35 g/L NaCl were treated by DSR process. A C/N ratio of 3:1 was proposed to maintain high S(0) conversion rate. The granular sludge with a compact structure and smooth outer surface was formed. The microbial communities of DSR consortium via high-throughput sequencing method suggested that salinity shifts the predominating heterotrophic denitrifiers at 10 g/L NaCl.

  6. Remediation of Sulfidic Wastewater by Aeration in the Presence of Ultrasonic Vibration

    Directory of Open Access Journals (Sweden)

    F. Ahmad

    2018-06-01

    Full Text Available In the current study, the aerial oxidation of sodium sulfide in the presence of ultrasonic vibration is investigated. Sulfide analysis was carried out by the methylene blue method. Sodium sulfide is oxidized to elemental sulfur in the presence of ultrasonic vibration. The influence of air flow rate, initial sodium sulfide concentration and ultrasonic vibration intensity on the oxidation of sodium sulfide was investigated. The rate law equation regarding the oxidation of sulfide was determined from the experimental data. The order of reaction with respect to sulfide and oxygen was found to be 0.36 and 0.67 respectively. The overall reaction followed nearly first order kinetics.

  7. Chemical Form Matters: Differential Accumulation of Mercury Following Inorganic and Organic Mercury Exposures in Zebrafish Larvae

    Energy Technology Data Exchange (ETDEWEB)

    Korbas, Malgorzata; MacDonald, Tracy C.; Pickering, Ingrid J.; George, Graham N.; Krone, Patrick H. (Saskatchewan)

    2013-04-08

    Mercury, one of the most toxic elements, exists in various chemical forms each with different toxicities and health implications. Some methylated mercury forms, one of which exists in fish and other seafood products, pose a potential threat, especially during embryonic and early postnatal development. Despite global concerns, little is known about the mechanisms underlying transport and toxicity of different mercury species. To investigate the impact of different mercury chemical forms on vertebrate development, we have successfully combined the zebrafish, a well-established developmental biology model system, with synchrotron-based X-ray fluorescence imaging. Our work revealed substantial differences in tissue-specific accumulation patterns of mercury in zebrafish larvae exposed to four different mercury formulations in water. Methylmercury species not only resulted in overall higher mercury burdens but also targeted different cells and tissues than their inorganic counterparts, thus revealing a significant role of speciation in cellular and molecular targeting and mercury sequestration. For methylmercury species, the highest mercury concentrations were in the eye lens epithelial cells, independent of the formulation ligand (chloride versus L-cysteine). For inorganic mercury species, in absence of L-cysteine, the olfactory epithelium and kidney accumulated the greatest amounts of mercury. However, with L-cysteine present in the treatment solution, mercuric bis-L-cysteineate species dominated the treatment, significantly decreasing uptake. Our results clearly demonstrate that the common differentiation between organic and inorganic mercury is not sufficient to determine the toxicity of various mercury species.

  8. The Plasma Environment at Mercury

    Science.gov (United States)

    Raines, James M.; Gershman, Daniel J.; Zurbuchen, Thomas H.; Gloeckler, George; Slavin, James A.; Anderson, Brian J.; Korth, Haje; Krimigis, Stamatios M.; Killen, Rosemary M.; Sarantos, Menalos; hide

    2011-01-01

    Mercury is the least explored terrestrial planet, and the one subjected to the highest flux of solar radiation in the heliosphere. Its highly dynamic, miniature magnetosphere contains ions from the exosphere and solar wind, and at times may allow solar wind ions to directly impact the planet's surface. Together these features create a plasma environment that shares many features with, but is nonetheless very different from, that of Earth. The first in situ measurements of plasma ions in the Mercury space environment were made only recently, by the Fast Imaging Plasma Spectrometer (FIPS) during the MESSENGER spacecraft's three flybys of the planet in 2008-2009 as the probe was en route to insertion into orbit about Mercury earlier this year. Here. we present analysis of flyby and early orbital mission data with novel techniques that address the particular challenges inherent in these measurements. First. spacecraft structures and sensor orientation limit the FIPS field of view and allow only partial sampling of velocity distribution functions. We use a software model of FIPS sampling in velocity space to explore these effects and recover bulk parameters under certain assumptions. Second, the low densities found in the Mercury magnetosphere result in a relatively low signal-to-noise ratio for many ions. To address this issue, we apply a kernel density spread function to guide removal of background counts according to a background-signature probability map. We then assign individual counts to particular ion species with a time-of-flight forward model, taking into account energy losses in the carbon foil and other physical behavior of ions within the instrument. Using these methods, we have derived bulk plasma properties and heavy ion composition and evaluated them in the context of the Mercury magnetosphere.

  9. Mercury emission from crematories in Japan

    Directory of Open Access Journals (Sweden)

    M. Takaoka

    2010-04-01

    Full Text Available Anthropogenic sources of mercury emissions have a significant impact on global pollution. Therefore, finding uncharacterised sources and assessing the emissions from these sources are important. However, limited data are available worldwide on mercury emissions from crematories. In Japan, 99.9% of dead bodies are cremated, which is the highest percentage in the world, and more than 1600 crematories are in operation. We thus focused on emissions from crematories in Japan. The number of targeted facilities was seven, and we used continuous emission monitoring to measure the mercury concentrations and investigate mercury behaviour. The total mercury concentrations in stack gases were a few μg/Nm3 (normal cubic meters. Considering the time profile of mercury and its species in cremations, the findings confirmed that the mercury in stack gas originated from dental amalgam. The amount of mercury emissions was calculated using the total concentration and gas flow rate. Furthermore, the annual amount of mercury emission from crematories in Japan was estimated by using the total number of corpses. The emission amount was considerably lower than that estimated in the United Kingdom. From statistical analyses on population demographics and measurements, future total emissions from crematories were also predicted. As a result, the amount of mercury emitted by crematories will likely increase by 2.6-fold from 2007 to 2037.

  10. Environmental Mercury and Its Toxic Effects

    Directory of Open Access Journals (Sweden)

    Kevin M. Rice

    2014-03-01

    Full Text Available Mercury exists naturally and as a man-made contaminant. The release of processed mercury can lead to a progressive increase in the amount of atmospheric mercury, which enters the atmospheric-soil-water distribution cycles where it can remain in circulation for years. Mercury poisoning is the result of exposure to mercury or mercury compounds resulting in various toxic effects depend on its chemical form and route of exposure. The major route of human exposure to methylmercury (MeHg is largely through eating contaminated fish, seafood, and wildlife which have been exposed to mercury through ingestion of contaminated lower organisms. MeHg toxicity is associated with nervous system damage in adults and impaired neurological development in infants and children. Ingested mercury may undergo bioaccumulation leading to progressive increases in body burdens. This review addresses the systemic pathophysiology of individual organ systems associated with mercury poisoning. Mercury has profound cellular, cardiovascular, hematological, pulmonary, renal, immunological, neurological, endocrine, reproductive, and embryonic toxicological effects.

  11. New Mechanisms of Mercury Binding to Peat

    Science.gov (United States)

    Nagy, K. L.; Manceau, A.; Gasper, J. D.; Ryan, J. N.; Aiken, G. R.

    2007-12-01

    Mercury can be immobilized in the aquatic environment by binding to peat, a solid form of natural organic matter. Binding mechanisms can vary in strength and reversibility, and therefore will control concentrations of bioreactive mercury, may explain rates of mercury methylation, and are important for designing approaches to improve water quality using natural wetlands or engineered phytoremediation schemes. In addition, strong binding between mercury and peat is likely to result in the fixation of mercury that ultimately resides in coal. The mechanisms by which aqueous mercury at low concentrations reacts with both dissolved and solid natural organic matter remain incompletely understood, despite recent efforts. We have identified three distinct binding mechanisms of divalent cationic mercury to solid peats from the Florida Everglades using EXAFS spectroscopic data (FAME beamline, European Synchrotron Radiation Facility (ESRF)) obtained on experimental samples as compared to relevant references including mercury-bearing solids and mercury bound to various organic molecules. The proportions of the three molecular configurations vary with Hg concentration, and two new configurations that involve sulfur ligands occur at Hg concentrations up to about 4000 ppm. The binding mechanism at the lowest experimental Hg concentration (60-80 ppm) elucidates published reports on the inhibition of metacinnabar formation in the presence of Hg-bearing solutions and dissolved natural organic matter, and also, the differences in extent of mercury methylation in distinct areas of the Florida Everglades.

  12. Mercury emissions from municipal solid waste combustors

    Energy Technology Data Exchange (ETDEWEB)

    1993-05-01

    This report examines emissions of mercury (Hg) from municipal solid waste (MSW) combustion in the United States (US). It is projected that total annual nationwide MSW combustor emissions of mercury could decrease from about 97 tonnes (1989 baseline uncontrolled emissions) to less than about 4 tonnes in the year 2000. This represents approximately a 95 percent reduction in the amount of mercury emitted from combusted MSW compared to the 1989 mercury emissions baseline. The likelihood that routinely achievable mercury emissions removal efficiencies of about 80 percent or more can be assured; it is estimated that MSW combustors in the US could prove to be a comparatively minor source of mercury emissions after about 1995. This forecast assumes that diligent measures to control mercury emissions, such as via use of supplemental control technologies (e.g., carbon adsorption), are generally employed at that time. However, no present consensus was found that such emissions control measures can be implemented industry-wide in the US within this time frame. Although the availability of technology is apparently not a limiting factor, practical implementation of necessary control technology may be limited by administrative constraints and other considerations (e.g., planning, budgeting, regulatory compliance requirements, etc.). These projections assume that: (a) about 80 percent mercury emissions reduction control efficiency is achieved with air pollution control equipment likely to be employed by that time; (b) most cylinder-shaped mercury-zinc (CSMZ) batteries used in hospital applications can be prevented from being disposed into the MSW stream or are replaced with alternative batteries that do not contain mercury; and (c) either the amount of mercury used in fluorescent lamps is decreased to an industry-wide average of about 27 milligrams of mercury per lamp or extensive diversion from the MSW stream of fluorescent lamps that contain mercury is accomplished.

  13. Enhanced sulfidation xanthate flotation of malachite using ammonium ions as activator

    OpenAIRE

    Dandan Wu; Wenhui Ma; Yingbo Mao; Jiushuai Deng; Shuming Wen

    2017-01-01

    In this study, ammonium ion was used to enhance the sulfidation flotation of malachite. The effect of ammonium ion on the sulfidation flotation of malachite was investigated using microflotation test, inductively coupled plasma (ICP) analysis, zeta potential measurements, and scanning electron microscope analysis (SEM). The results of microflotation test show that the addition of sodium sulfide and ammonium sulfate resulted in better sulfidation than the addition of sodium sulfide alone. The ...

  14. Instrument for Airborne Measurement of Carbonyl Sulfide, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Southwest Sciences proposes to develop small, low power instrumentation for the real-time direct measurement of carbonyl sulfide (OCS) in the atmosphere, especially...

  15. New sulfide catalysts for the hydroliquefaction of coal

    NARCIS (Netherlands)

    Vissers, J.P.R.; Oers, van E.M.; Beer, de V.H.J.; Prins, R.

    1987-01-01

    Possibilities for the preparation of new metal sulfide catalyst systems based on carbon carriers having favourable textural and surface properties have been explored, and attention has been given to the characterization (structure) and evaluation (hydrosulfurization activity) of these catalysts. Two

  16. Formation of Copper Sulfide Precipitate in Solid Iron

    Science.gov (United States)

    Urata, Kentaro; Kobayashi, Yoshinao

    The growth rate of copper sulfide precipitates has been measured in low carbon steel samples such as Fe-0.3mass%Cu-0.03mass%S-0.1mass%C and Fe-0.1mass%Cu-0.01mass%S- 0.1mass%C. Heat-treatment of the samples was conducted at 1273, 1423 and 1573 K for 100 s - 14.4 ks for precipitation of copper sulfides and then the samples were observed by a scanning electron microscope and a transmission electron microscope to measure the diameter of copper sulfides precipitated in the samples. The growth rate of copper sulfide has been found to be well described by the Ostwald growth model, as follows: R\

  17. Optimization of biological sulfide removal in a CSTR bioreactor.

    Science.gov (United States)

    Roosta, Aliakbar; Jahanmiri, Abdolhossein; Mowla, Dariush; Niazi, Ali; Sotoodeh, Hamidreza

    2012-08-01

    In this study, biological sulfide removal from natural gas in a continuous bioreactor is investigated for estimation of the optimal operational parameters. According to the carried out reactions, sulfide can be converted to elemental sulfur, sulfate, thiosulfate, and polysulfide, of which elemental sulfur is the desired product. A mathematical model is developed and was used for investigation of the effect of various parameters on elemental sulfur selectivity. The results of the simulation show that elemental sulfur selectivity is a function of dissolved oxygen, sulfide load, pH, and concentration of bacteria. Optimal parameter values are calculated for maximum elemental sulfur selectivity by using genetic algorithm as an adaptive heuristic search. In the optimal conditions, 87.76% of sulfide loaded to the bioreactor is converted to elemental sulfur.

  18. Overview of Mercury Magnetospheric Orbiter (MMO) for BepiColombo

    Science.gov (United States)

    Murakami, G.; Hayakawa, H.; Fujimoto, M.; BepiColombo Project Team

    2018-05-01

    The next Mercury exploration mission BepiColombo will be launched in October 2018 and will arrive at Mercury in December 2025. We present the current status, science goals, and observation plans of JAXA's Mercury Magnetospheric Orbiter (MMO).

  19. INVESTIGATIONS ON BIOCHEMICAL PURIFICATION OF GROUND WATER FROM HYDROGEN SULFIDE

    Directory of Open Access Journals (Sweden)

    Yu. P. Sedlukho

    2015-01-01

    Full Text Available The paper considers problems and features of biochemical removal of hydrogen sulfide from ground water. The analysis of existing methods for purification of ground water from hydrogen sulfide has been given in the paper. The paper has established shortcomings of physical and chemical purification of ground water. While using aeration methods for removal of hydrogen sulfide formation of colloidal sulfur that gives muddiness and opalescence to water occurs due to partial chemical air oxidation. In addition to this violation of sulfide-carbonate equilibrium taking place in the process of aeration due to desorption of H2S and CO2, often leads to clogging of degasifier nozzles with formed CaCO3 that causes serious operational problems. Chemical methods require relatively large flow of complex reagent facilities, storage facilities and transportation costs.In terms of hydrogen sulfide ground water purification the greatest interest is given to the biochemical method. Factors deterring widespread application of the biochemical method is its insufficient previous investigation and necessity to execute special research in order to determine optimal process parameters while purifying groundwater of a particular water supply source. Biochemical methods for oxidation of sulfur compounds are based on natural biological processes that ensure natural sulfur cycle. S. Vinogradsky has established a two-stage mechanism for oxidation of hydrogen sulfide with sulfur bacteria (Beggiatoa. The first stage presupposes oxidation of hydrogen sulphide to elemental sulfur which is accumulating in the cytoplasm in the form of globules. During the second stage sulfur bacteria begin to oxidize intracellular sulfur to sulfuric acid due to shortage of hydrogen sulfide.The paper provides the results of technological tests of large-scale pilot plants for biochemical purification of groundwater from hydrogen sulfide in semi-industrial conditions. Dependences of water quality

  20. Determination of Hydrogen Sulfide in Fermentation Broths Containing SO21

    Science.gov (United States)

    Acree, T. E.; Sonoff, Elisabeth P.; Splittstoesser, D. F.

    1971-01-01

    A procedure for the determination of hydrogen sulfide in fermentation broths containing up to 100 μg of SO2 per ml is described. The method involves the sparging of H2S from the broth into a cadmium hydroxide absorption solution, the formation of methylene blue from the absorbed sulfide, and the measuring of this color spectrophotometrically. The use of cadmium hydroxide instead of zinc acetate, the common absorbent, substantially reduced the interference of SO2 with the analysis. PMID:5111300

  1. Spatial variation of mercury bioaccumulation in bats of Canada linked to atmospheric mercury deposition.

    Science.gov (United States)

    Chételat, John; Hickey, M Brian C; Poulain, Alexandre J; Dastoor, Ashu; Ryjkov, Andrei; McAlpine, Donald; Vanderwolf, Karen; Jung, Thomas S; Hale, Lesley; Cooke, Emma L L; Hobson, Dave; Jonasson, Kristin; Kaupas, Laura; McCarthy, Sara; McClelland, Christine; Morningstar, Derek; Norquay, Kaleigh J O; Novy, Richard; Player, Delanie; Redford, Tony; Simard, Anouk; Stamler, Samantha; Webber, Quinn M R; Yumvihoze, Emmanuel; Zanuttig, Michelle

    2018-06-01

    Wildlife are exposed to neurotoxic mercury at locations distant from anthropogenic emission sources because of long-range atmospheric transport of this metal. In this study, mercury bioaccumulation in insectivorous bat species (Mammalia: Chiroptera) was investigated on a broad geographic scale in Canada. Fur was analyzed (n=1178) for total mercury from 43 locations spanning 20° latitude and 77° longitude. Total mercury and methylmercury concentrations in fur were positively correlated with concentrations in internal tissues (brain, liver, kidney) for a small subset (n=21) of little brown bats (Myotis lucifugus) and big brown bats (Eptesicus fuscus), validating the use of fur to indicate internal mercury exposure. Brain methylmercury concentrations were approximately 10% of total mercury concentrations in fur. Three bat species were mainly collected (little brown bats, big brown bats, and northern long-eared bats [M. septentrionalis]), with little brown bats having lower total mercury concentrations in their fur than the other two species at sites where both species were sampled. On average, juvenile bats had lower total mercury concentrations than adults but no differences were found between males and females of a species. Combining our dataset with previously published data for eastern Canada, median total mercury concentrations in fur of little brown bats ranged from 0.88-12.78μg/g among 11 provinces and territories. Highest concentrations were found in eastern Canada where bats are most endangered from introduced disease. Model estimates of atmospheric mercury deposition indicated that eastern Canada was exposed to greater mercury deposition than central and western sites. Further, mean total mercury concentrations in fur of adult little brown bats were positively correlated with site-specific estimates of atmospheric mercury deposition. This study provides the largest geographic coverage of mercury measurements in bats to date and indicates that atmospheric

  2. Mercury Flow Through the Mercury-Containing Lamp Sector of the Economy of the United States

    Science.gov (United States)

    Goonan, Thomas G.

    2006-01-01

    Introduction: This Scientific Investigations Report examines the flow of mercury through the mercury-containing lamp sector of the U.S. economy in 2001 from lamp manufacture through disposal or recycling. Mercury-containing lamps illuminate commercial and industrial buildings, outdoor areas, and residences. Mercury is an essential component in fluorescent lamps and high-intensity discharge lamps (high-pressure sodium, mercury-vapor, and metal halide). A typical fluorescent lamp is composed of a phosphor-coated glass tube with electrodes located at either end. Only a very small amount of the mercury is in vapor form. The remainder of the mercury is in the form of either liquid mercury metal or solid mercury oxide (mercury oxidizes over the life of the lamp). When voltage is applied, the electrodes energize the mercury vapor and cause it to emit ultraviolet energy. The phosphor coating absorbs the ultraviolet energy, which causes the phosphor to fluoresce and emit visible light. Mercury-containing lamps provide more lumens per watt than incandescent lamps and, as a result, require from three to four times less energy to operate. Mercury is persistent and toxic within the environment. Mercury-containing lamps are of environmental concern because they are widely distributed throughout the environment and are easily broken in handling. The magnitude of lamp sector mercury emissions, estimated to be 2.9 metric tons per year (t/yr), is small compared with the estimated mercury losses of the U.S. coal-burning and chlor-alkali industries, which are about 70 t/yr and about 90 t/yr, respectively.

  3. Amended Silicated for Mercury Control

    Energy Technology Data Exchange (ETDEWEB)

    James Butz; Thomas Broderick; Craig Turchi

    2006-12-31

    Amended Silicates{trademark}, a powdered, noncarbon mercury-control sorbent, was tested at Duke Energy's Miami Fort Station, Unit 6 during the first quarter of 2006. Unit 6 is a 175-MW boiler with a cold-side electrostatic precipitator (ESP). The plant burns run-of-the-river eastern bituminous coal with typical ash contents ranging from 8-15% and sulfur contents from 1.6-2.6% on an as-received basis. The performance of the Amended Silicates sorbent was compared with that for powdered activated carbon (PAC). The trial began with a period of baseline monitoring during which no sorbent was injected. Sampling during this and subsequent periods indicated mercury capture by the native fly ash was less than 10%. After the baseline period, Amended Silicates sorbent was injected at several different ratios, followed by a 30-day trial at a fixed injection ratio of 5-6 lb/MMACF. After this period, PAC was injected to provide a comparison. Approximately 40% mercury control was achieved for both the Amended Silicates sorbent and PAC at injection ratios of 5-6 lbs/MMACF. Higher injection ratios did not achieve significantly increased removal. Similar removal efficiencies have been reported for PAC injection trials at other plants with cold-side ESPs, most notably for plants using medium to high sulfur coal. Sorbent injection did not detrimentally impact plant operations and testing confirmed that the use of Amended Silicates sorbent does not degrade fly ash quality (unlike PAC). The cost for mercury control using either PAC or Amended Silicates sorbent was estimated to be equivalent if fly ash sales are not a consideration. However, if the plant did sell fly ash, the effective cost for mercury control could more than double if those sales were no longer possible, due to lost by-product sales and additional cost for waste disposal. Accordingly, the use of Amended Silicates sorbent could reduce the overall cost of mercury control by 50% or more versus PAC for locations where

  4. Human accumulation of mercury in Greenland

    DEFF Research Database (Denmark)

    Johansen, Poul; Mulvad, Gert; Pedersen, Henning Sloth

    2007-01-01

    In the Arctic, the traditional diet exposes its people to a high intake of mercury especially from marine mammals. To determine whether the mercury is accumulated in humans, we analyzed autopsy samples of liver, kidney and spleen from adult ethnic Greenlanders who died between 1990 and 1994 from...... a wide range of causes, natural and violent. Liver, kidney and spleen samples from between 33 and 71 case subjects were analyzed for total mercury and methylmercury, and liver samples also for selenium. Metal levels in men and women did not differ and were not related to age except in one case, i.......e. for total mercury in liver, where a significant declining concentration with age was observed. The highest total mercury levels were found in kidney followed by liver and spleen. Methylmercury followed the same pattern, but levels were much lower, constituting only 19% of the total mercury concentration...

  5. Acclimation of subsurface microbial communities to mercury

    DEFF Research Database (Denmark)

    de Lipthay, Julia R; Rasmussen, Lasse D; Øregaard, Gunnar

    2008-01-01

    of mercury tolerance and functional versatility of bacterial communities in contaminated soils initially were higher for surface soil, compared with the deeper soils. However, following new mercury exposure, no differences between bacterial communities were observed, which indicates a high adaptive potential......We studied the acclimation to mercury of bacterial communities of different depths from contaminated and noncontaminated floodplain soils. The level of mercury tolerance of the bacterial communities from the contaminated site was higher than those of the reference site. Furthermore, the level...... of the subsurface communities, possibly due to differences in the availability of mercury. IncP-1 trfA genes were detected in extracted community DNA from all soil depths of the contaminated site, and this finding was correlated to the isolation of four different mercury-resistance plasmids, all belonging...

  6. Action of mercury as a soil fungicide

    Energy Technology Data Exchange (ETDEWEB)

    Booer, J R

    1951-01-01

    Metallic mercury and mercury compounds in the soil retard the growth of plants. The development of mosses and lichens is inhibited, and experimental evidence shows that the growth of toadstools on turf and the activity of ascomycetes is retarded by mercury. In vitro, mercury has no fungicidal action but the rate of growth of hyphae is reduced by mercury vapour. The lack of fungicial properties of mercury and its good performance in controlling certain soil-borne diseases are reconciled by assuming that a differential retardation disturbs the relationships necessary for infection. This assumption is supported by diagrams which treat the rates of growth of the parasite and the host as population characteristics normally distributed. 21 references, 10 figures, 5 tables.

  7. Human accumulation of mercury in Greenland

    DEFF Research Database (Denmark)

    Johansen, P.; Mulvad, G.; Pedersen, H. S.

    2007-01-01

    a wide range of causes, natural and violent. Liver, kidney and spleen samples from between 33 and 71 case subjects were analyzed for total mercury and methylmercury, and liver samples also for selenium. Metal levels in men and women did not differ and were not related to age except in one case, i......In the Arctic, the traditional diet exposes its people to a high intake of mercury especially from marine mammals. To determine whether the mercury is accumulated in humans, we analyzed autopsy samples of liver, kidney and spleen from adult ethnic Greenlanders who died between 1990 and 1994 from.......e. for total mercury in liver, where a significant declining concentration with age was observed. The highest total mercury levels were found in kidney followed by liver and spleen. Methylmercury followed the same pattern, but levels were much lower, constituting only 19% of the total mercury concentration...

  8. Hydrogen sulfide oxidation without oxygen - oxidation products and pathways

    International Nuclear Information System (INIS)

    Fossing, H.

    1992-01-01

    Hydrogen sulfide oxidation was studied in anoxic marine sediments-both in undisturbed sediment cores and in sediment slurries. The turn over of hydrogen sulfide was followed using 35 S-radiolabeled hydrogen sulfide which was injected into the sediment. However, isotope exchange reactions between the reduced sulfur compounds, in particular between elemental sulfur and hydrogen sulfide, influenced on the specific radioactivity of these pools. It was, therefore, not possible to measure the turn over rates of the reduced sulfur pools by the radiotracer technique but merely to use the radioisotope to demonstrate some of the oxidation products. Thiosulfate was one important intermediate in the anoxic oxidation of hydrogen sulfide and was continuously turned over by reduction, oxidation and disproportionation. The author discusses the importance of isotope exchange and also presents the results from experiments in which both 35 S-radiolabeled elemental sulfur, radiolabeled hydrogen sulfide and radiolabeled thiosulfate were used to study the intermediates in the oxidative pathways of the sulfur cycle

  9. Laser cleaning of sulfide scale on compressor impeller blade

    International Nuclear Information System (INIS)

    Tang, Q.H.; Zhou, D.; Wang, Y.L.; Liu, G.F.

    2015-01-01

    Highlights: • The effects of sulfide layers and fluence values on the mechanism of laser cleaning were experimentally established. • The specimen surface with sulfide scale becomes slightly smoother than that before laser cleaning. • The mechanism of laser cleaning the sulfide scale of stainless steel is spallation without oxidization. • It would avoid chemical waste and dust pollution using a fiber laser instead of using nitric acids or sandblasting. - Abstract: Sulfide scale on the surface of a compressor impeller blade can considerably reduce the impeller performance and its service life. To prepare for subsequent remanufacturing, such as plasma spraying, it needs to be removed completely. In the corrosion process on an FV(520)B stainless steel, sulfide scale is divided into two layers because of different outward diffusion rates of Cr, Ni and Fe. In this paper, the cleaning threshold values of the upper and inner layers and the damage threshold value of the substrate were investigated using a pulsed fiber laser. To obtain experimental evidence, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and 3D surface profilometry were employed to investigate the two kinds of sulfide layers on specimens before, during, and after laser cleaning.

  10. Hydrogen sulfide production from subgingival plaque samples.

    Science.gov (United States)

    Basic, A; Dahlén, G

    2015-10-01

    Periodontitis is a polymicrobial anaerobe infection. Little is known about the dysbiotic microbiota and the role of bacterial metabolites in the disease process. It is suggested that the production of certain waste products in the proteolytic metabolism may work as markers for disease severity. Hydrogen sulfide (H2S) is a gas produced by degradation of proteins in the subgingival pocket. It is highly toxic and believed to have pro-inflammatory properties. We aimed to study H2S production from subgingival plaque samples in relation to disease severity in subjects with natural development of the disease, using a colorimetric method based on bismuth precipitation. In remote areas of northern Thailand, adults with poor oral hygiene habits and a natural development of periodontal disease were examined for their oral health status. H2S production was measured with the bismuth method and subgingival plaque samples were analyzed for the presence of 20 bacterial species with the checkerboard DNA-DNA hybridization technique. In total, 43 subjects were examined (age 40-60 years, mean PI 95 ± 6.6%). Fifty-six percent had moderate periodontal breakdown (CAL > 3  7 mm) on at least one site. Parvimonas micra, Filifactor alocis, Porphyromonas endodontalis and Fusobacterium nucleatum were frequently detected. H2S production could not be correlated to periodontal disease severity (PPD or CAL at sampled sites) or to a specific bacterial composition. Site 21 had statistically lower production of H2S (p = 0.02) compared to 16 and 46. Betel nut chewers had statistically significant lower H2S production (p = 0.01) than non-chewers. Rapid detection and estimation of subgingival H2S production capacity was easily and reliably tested by the colorimetric bismuth sulfide precipitation method. H2S may be a valuable clinical marker for degradation of proteins in the subgingival pocket. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Thiosulphate assisted phytoextraction of mercury contaminated soils at the Wanshan Mercury Mining District, Southwest China

    Directory of Open Access Journals (Sweden)

    J. Wang

    2013-10-01

    Full Text Available Wanshan, known as the “Mercury Capital” of China, is located in the Southwest of China. Due to the extensive mining and smelting works in the Wanshan area, the local ecosystem has been serious contaminated with mercury. In the present study, a number of soil samples were taken from the Wanshan mercury mining area and the mercury fractionations in soils were analyzed using sequential extraction procedure technique. The obtained results showed that the dominate mercury fractions (represent 95% of total mercury were residual and organic bound mercury. A field trial was conducted in a mercury polluted farmland at the Wanshan mercury mine. Four plant species Brassica juncea Czern. et Coss.var. ASKYC (ASKYC, Brassica juncea Czern. et Coss.var.DPDH (DPDH, Brassica juncea Czern. et Coss.var.CHBD(CHBD, Brassica juncea Czern. et Coss.var.LDZY (LDZY were tested their ability to extract mercury from soil with thiosulphate amendment. The results indicated that the mercury concentration in the roots and shoots of the four plants were significantly increased with thiosulphate treatment. The mercury phytoextraction yield of ASKYC, DPDH, CHBD and LDZY were 92, 526, 294 and 129 g/ha, respectively

  12. Thiosulphate assisted phytoextraction of mercury contaminated soils at the Wanshan Mercury Mining District, Southwest China

    Directory of Open Access Journals (Sweden)

    J Wang

    2013-10-01

    Full Text Available Wanshan, known as the “Mercury Capital” of China, is located in the Southwest of China. Due to the extensive mining and smelting works in the Wanshan area, the local ecosystem has been serious contaminated with mercury. In the present study, a number of soil samples were taken from the Wanshan mercury mining area and the mercury fractionations in soils were analyzed using sequential extraction procedure technique. The obtained results showed that the dominate mercury fractions (represent 95% of total mercury were residual and organic bound mercury. A field trial was conducted in a mercury polluted farmland at the Wanshan mercury mine. Four plant species Brassica juncea Czern. et Coss.var. ASKYC (ASKYC, Brassica juncea Czern. et Coss.var.DPDH (DPDH, Brassica juncea Czern. et Coss.var.CHBD(CHBD, Brassica juncea Czern. et Coss.var.LDZY (LDZY were tested their ability to extract mercury from soil with thiosulphate amendment. The results indicated that the mercury concentration in the roots and shoots of the four plants were significantly increased with thiosulphate treatment. The mercury phytoextraction yield of ASKYC, DPDH, CHBD and LDZY were 92, 526, 294 and 129 g/ha, respectively.

  13. Radioactive mercury distribution in biological fluids and excretion in human subjects after inhalation of mercury vapor

    International Nuclear Information System (INIS)

    Cherian, M.G.; Hursh, J.B.; Clarkson, T.W.; Allen, J.

    1978-01-01

    The distribution of mercury in red blood cells (RBCs) and plasma, and its excretion in urine and feces are described in five human subjects during the first 7 days following inhalation of radioactive mercury vapor. A major portion (98%) of radioactive mercury in whole blood is initially accumulated in the RBCs and is transferred partly to the plasma compartment until the ratio of mercury in RBCs to plasma is about 2 within 20 h. The cumulative urinary and fecal excretion of mercury for 7 days is about 11.6% of the retained dose, and is closely related to the percent decline in body burden of mercury. There is little correlation between either the urinary excretion and plasma radioactivity of mercury, or the specific activities of urine and plasma mercury, suggesting a mechanism other than a direct glomerular filtration involved in the urinary excretion of recently exposed mercury. These studies suggest that blood mercury levels can be used as an index of recent exposure, while urinary levels may be an index of renal concentration of mercury. However, there is no reliable index for mercury concentration in the brain

  14. Physiological behavior of hydrogen sulfide in rice plant. Part 5. Effect of hydrogen sulfide on respiration of rice roots

    Energy Technology Data Exchange (ETDEWEB)

    Okajima, H; Takagi, S

    1955-01-01

    The inhibitory effects of hydrogen sulfide on the respiration of rice plant roots were investigated using Warburg's manometory technique. Hydrogen sulfide inhibited not only aerobic respiration but anaerobic respiration process of roots. Inhibitory action of hydrogen sulfide and potassium cyanide on the respiration were apparently reversible, but the style of recovery reaction from inhibition was somewhat different in each case. Oxygen consumption of roots was increased by addition of ammonium salts, but the same effects were not recognized by the addition of any other salt examined (except nitrate salts). There was close relationship between respiration of roots and assimilation of nitrogen by roots. The increased oxygen uptake by addition of ammonium salt was also inhibited by hydrogen sulfide. The reactivation of this reaction occurred with the recovery of endogenous respiration of roots. 19 references, 8 figures, 3 tables.

  15. Surface composition of Mercury from reflectance spectrophotometry

    Science.gov (United States)

    Vilas, Faith

    1988-01-01

    The controversies surrounding the existing spectra of Mercury are discussed together with the various implications for interpretations of Mercury's surface composition. Special attention is given to the basic procedure used for reducing reflectance spectrophotometry data, the factors that must be accounted for in the reduction of these data, and the methodology for defining the portion of the surface contributing the greatest amount of light to an individual spectrum. The application of these methodologies to Mercury's spectra is presented.

  16. Mercury concentration in coal - Unraveling the puzzle

    Science.gov (United States)

    Toole-O'Neil, B.; Tewalt, S.J.; Finkelman, R.B.; Akers, D.J.

    1999-01-01

    Based on data from the US Geological Survey's COALQUAL database, the mean concentration of mercury in coal is approximately 0.2 ??gg-1. Assuming the database reflects in-ground US coal resources, values for conterminous US coal areas range from 0.08 ??gg-1 for coal in the San Juan and Uinta regions to 0.22 ??gg-1 for the Gulf Coast lignites. Recalculating the COALQUAL data to an equal energy basis unadjusted for moisture differences, the Gulf Coast lignites have the highest values (36.4 lb of Hg/1012 Btu) and the Hams Fork region coal has the lowest value (4.8 lb of Hg/1012Btu). Strong indirect geochemical evidence indicates that a substantial proportion of the mercury in coal is associated with pyrite occurrence. This association of mercury and pyrite probably accounts for the removal of mercury with the pyrite by physical coal cleaning procedures. Data from the literature indicate that conventional coal cleaning removes approximately 37% of the mercury on an equal energy basis, with a range of 0% to 78%. When the average mercury reduction value is applied to in-ground mercury values from the COALQUAL database, the resulting 'cleaned' mercury values are very close to mercury in 'as-shipped' coal from the same coal bed in the same county. Applying the reduction fact or for coal cleaning to eastern US bituminous coal, reduces the mercury input load compared to lower-rank non-deaned western US coal. In the absence of analytical data on as-shipped coal, the mercury data in the COALQUAL database, adjusted for deanability where appropriate, may be used as an estimator of mercury contents of as-shipped coal. ?? 1998 Published by Elsevier Science Ltd. All rights reserved.

  17. Mercury and halogens in coal: Chapter 2

    Science.gov (United States)

    Kolker, Allan; Quick, Jeffrey C.; Granite, Evan J.; Pennline, Henry W.; Senior, Constance L.

    2014-01-01

    Apart from mercury itself, coal rank and halogen content are among the most important factors inherent in coal that determine the proportion of mercury captured by conventional controls during coal combustion. This chapter reviews how mercury in coal occurs, gives available concentration data for mercury in U.S. and international commercial coals, and provides an overview of the natural variation in halogens that influence mercury capture. Three databases, the U.S. Geological Survey coal quality (USGS COALQUAL) database for in-ground coals, and the 1999 and 2010 U.S. Environmental Protection Agency (EPA) Information Collection Request (ICR) databases for coals delivered to power stations, provide extensive results for mercury and other parameters that are compared in this chapter. In addition to the United States, detailed characterization of mercury is available on a nationwide basis for China, whose mean values in recent compilations are very similar to the United States in-ground mean of 0.17 ppm mercury. Available data for the next five largest producers (India, Australia, South Africa, the Russian Federation, and Indonesia) are more limited and with the possible exceptions of Australia and the Russian Federation, do not allow nationwide means for mercury in coal to be calculated. Chlorine in coal varies as a function of rank and correspondingly, depth of burial. As discussed elsewhere in this volume, on a proportional basis, bromine is more effective than chlorine in promoting mercury oxidation in flue gas and capture by conventional controls. The ratio of bromine to chlorine in coal is indicative of the proportion of halogens present in formation waters within a coal basin. This ratio is relatively constant except in coals that have interacted with deep-basin brines that have reached halite saturation, enriching residual fluids in bromine. Results presented here help optimize mercury capture by conventional controls and provide a starting point for

  18. Apparatus for isotopic alteration of mercury vapor

    International Nuclear Information System (INIS)

    Grossman, M.W.; George, W.A.; Marcucci, R.V.

    1988-01-01

    This patent describes an apparatus for enriching the isotopic content of mercury. It comprises: a low pressure electric discharge lamp, the lamp comprising an envelope transparent to ultraviolet radiation and containing a fill comprising mercury and an inert gas; a filter concentrically arranged around the low pressure electric discharge lamp, the filter being transparent to ultraviolet radiation and containing mercury including 196 Hg isotope; means for controlling mercury pressure in the filter; and a reactor arranged around the filter such that radiation passes from the low pressure electric discharge lamp through the filter and into Said reactor, the reactor being transparent to ultraviolet light

  19. Alkaline sorbent injection for mercury control

    Science.gov (United States)

    Madden, Deborah A.; Holmes, Michael J.

    2002-01-01

    A mercury removal system for removing mercury from combustion flue gases is provided in which alkaline sorbents at generally extremely low stoichiometric molar ratios of alkaline earth or an alkali metal to sulfur of less than 1.0 are injected into a power plant system at one or more locations to remove at least between about 40% and 60% of the mercury content from combustion flue gases. Small amounts of alkaline sorbents are injected into the flue gas stream at a relatively low rate. A particulate filter is used to remove mercury-containing particles downstream of each injection point used in the power plant system.

  20. Apparatus for isotopic alteration of mercury vapor

    Science.gov (United States)

    Grossman, Mark W.; George, William A.; Marcucci, Rudolph V.

    1988-01-01

    An apparatus for enriching the isotopic Hg content of mercury is provided. The apparatus includes a reactor, a low pressure electric discharge lamp containing a fill including mercury and an inert gas. A filter is arranged concentrically around the lamp. In a preferred embodiment, constant mercury pressure is maintained in the filter by means of a water-cooled tube that depends from it, the tube having a drop of mercury disposed in it. The reactor is arranged around the filter, whereby radiation from said lamp passes through the filter and into said reactor. The lamp, the filter and the reactor are formed of a material which is transparent to ultraviolet light.

  1. Identification of elemental mercury in the subsurface

    Science.gov (United States)

    Jackson, Dennis G

    2015-01-06

    An apparatus and process is provided for detecting elemental mercury in soil. A sacrificial electrode of aluminum is inserted below ground to a desired location using direct-push/cone-penetrometer based equipment. The insertion process removes any oxides or previously found mercury from the electrode surface. Any mercury present adjacent the electrode can be detected using a voltmeter which indicates the presence or absence of mercury. Upon repositioning the electrode within the soil, a fresh surface of the aluminum electrode is created allowing additional new measurements.

  2. Coal fired flue gas mercury emission controls

    International Nuclear Information System (INIS)

    Wu, Jiang; Pan, Weiguo; Cao, Yan; Pan, Weiping

    2015-01-01

    Mercury (Hg) is one of the most toxic heavy metals, harmful to both the environment and human health. Hg is released into the atmosphere from natural and anthropogenic sources and its emission control has caused much concern. This book introduces readers to Hg pollution from natural and anthropogenic sources and systematically describes coal-fired flue gas mercury emission control in industry, especially from coal-fired power stations. Mercury emission control theory and experimental research are demonstrated, including how elemental mercury is oxidized into oxidized mercury and the effect of flue gas contents on the mercury speciation transformation process. Mercury emission control methods, such as existing APCDs (air pollution control devices) at power stations, sorbent injection, additives in coal combustion and photo-catalytic methods are introduced in detail. Lab-scale, pilot-scale and full-scale experimental studies of sorbent injection conducted by the authors are presented systematically, helping researchers and engineers to understand how this approach reduces the mercury emissions in flue gas and to apply the methods in mercury emission control at coal-fired power stations.

  3. Observations of Mercury in 1988 and 1989

    International Nuclear Information System (INIS)

    Schmude, R.W. Jr.

    1990-01-01

    A visual study of the planet Mercury was carried out in May 1988 and in April and May 1989. Most of the observations were made with the 35.5-cm telescope at the Texas A ampersand M University Observatory. This report presents drawings and a map of Mercury that covers the longitude range of 195-285 deg. One important finding was that a polarizing filter combined with color filters gives a sharper view of the planet. It is also concluded that high-resolution images of Mercury's terminator, either as seen from the earth or with the Hubble Space Telescope, can provide information about Mercury's topography. 10 refs

  4. Fate of mercury in the Arctic (FOMA)

    DEFF Research Database (Denmark)

    Skov, H.; Christensen, J.; Asmund, G.

    This report is the final reporting of the project FONA, funded by the Danish Environmental Protection Agency with means from the MIKA/DANCEA funds for Environmental Support to the Arctic Region. The aim of the project is to study the intercompartment mercury transport chain in the arctic area. From...... in the Arctic. The report focus on the surface exchange of mercury, the uptake of abiotic mercury into the biological system, and the bioaccumulation in the first steps of the food web, and the resulting distribution and time trend of mercury in selected animals feeding on various trophic levels...

  5. Sorbents for mercury removal from flue gas

    Energy Technology Data Exchange (ETDEWEB)

    Granite, Evan J.; Hargis, Richard A.; Pennline, Henry W.

    1998-01-01

    A review of the various promoters and sorbents examined for the removal of mercury from flue gas is presented. Commercial sorbent processes are described along with the chemistry of the various sorbent-mercury interactions. Novel sorbents for removing mercury from flue gas are suggested. Since activated carbons are expensive, alternate sorbents and/or improved activated carbons are needed. Because of their lower cost, sorbent development work can focus on base metal oxides and halides. Additionally, the long-term sequestration of the mercury on the sorbent needs to be addressed. Contacting methods between the flue gas and the sorbent also merit investigation.

  6. Coal fired flue gas mercury emission controls

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jiang; Pan, Weiguo [Shanghai Univ. of Electric Power (China); Cao, Yan; Pan, Weiping [Western Kentucky Univ., Bowling Green, KY (United States)

    2015-05-01

    Mercury (Hg) is one of the most toxic heavy metals, harmful to both the environment and human health. Hg is released into the atmosphere from natural and anthropogenic sources and its emission control has caused much concern. This book introduces readers to Hg pollution from natural and anthropogenic sources and systematically describes coal-fired flue gas mercury emission control in industry, especially from coal-fired power stations. Mercury emission control theory and experimental research are demonstrated, including how elemental mercury is oxidized into oxidized mercury and the effect of flue gas contents on the mercury speciation transformation process. Mercury emission control methods, such as existing APCDs (air pollution control devices) at power stations, sorbent injection, additives in coal combustion and photo-catalytic methods are introduced in detail. Lab-scale, pilot-scale and full-scale experimental studies of sorbent injection conducted by the authors are presented systematically, helping researchers and engineers to understand how this approach reduces the mercury emissions in flue gas and to apply the methods in mercury emission control at coal-fired power stations.

  7. Risk assessment of mercury contaminated sites

    International Nuclear Information System (INIS)

    Hempel, M.

    1993-01-01

    At two sites, highly contaminated with mercury, risk assessment was executed. Methods were developed to determine organomercury compounds in water, air and soil. Toxicity tests demonstrated the high toxicity of organomercury compounds compared to inorganic mercury. Besides highly toxic methylmercury, ethylmercury was found in soils close to a chemical plant in Marktredwitz. In ultrafiltration-experiments mercury showed great affinity to high molecular substances in water. Lysimeter-experiments proved, that organomercury compounds are adsorbed and transformed to inorganic and elemental mercury. (orig.) [de

  8. EDITORIAL: Mercury-free discharges for lighting

    Science.gov (United States)

    Haverlag, M.

    2007-07-01

    This special Cluster of articles in Journal of Physics D: Applied Physics covers the subject of mercury-free discharges that are being investigated by different light source researchers, as an alternative to existing mercury-containing lamps. The main driving force to move away from mercury-containing discharge light sources is connected to the environmentally unfriendly nature of mercury. After inhalation or direct contact, severe mercury exposure can lead to damage to human brain cells, the kidneys, the liver and the nervous system. For this reason, the use of mercury in products is becoming more and more restricted by different governmental bodies. In the lighting industry, however, many products still make use of mercury, for different reasons. The main reason is that mercury-containing products are, in most cases, more efficient than mercury-free products. For a realistic comparison of the environmental impact, the mercury-contamination due to electricity production must be taken into account, which depends on the type of fuel being used. For an average European fuel-mix, the amount of mercury that is released into the environment is around 29 μg kWh-1. This means that a typical 30 W TL lamp during a lifetime of 20,000 hours will release a total of about 20 mg mercury due to electricity production, which exceeds the total mercury dose in the lamp (more and more of which is being recycled) by a factor of 5-10 for a modern TL lamp. This illustrates that, quite apart from other environmental arguments like increased CO2 production, mercury-free alternatives that use more energy can in fact be detrimental for the total mercury pollution over the lifetime of the lamp. For this reason, the lighting industry has concentrated on lowering the mercury content in lamps as long as no efficient alternatives exist. Nevertheless, new initiatives for HID lamps and fluorescent lamps with more or less equal efficiency are underway, and a number of them are described in this

  9. Phytoremediation of Ionic and Methyl Mercury Pollution

    Energy Technology Data Exchange (ETDEWEB)

    Meagher, Richard B.

    2005-06-01

    Phytoremediation is defined as the use of plants to extract, resist, detoxify, and/or sequester toxic environmental pollutants. The long-term goal of the proposed research is to develop and test highly productive, field-adapted plant species that have been engineered for the phytoremediation of mercury. A variety of different genes, which should enable plants to clean mercury polluted sites are being tested as tools for mercury phytoremediation, first in model laboratory plants and then in potential field species. Several of these genes have already been shown to enhance mercury phytoremediation. Mercury pollution is a serious, world-wide problem affecting the health of human and wildlife populations. Environmentally, the most serious mercury threat is the production of methylmercury (CH3Hg+) by native bacteria at mercury contaminated wetland sites. Methylmercury is inherently more toxic than metallic (Hg(0)) or ionic (Hg(II)) mercury, and because methylmercury is prolifically biomagnified up the food chain, it poses the most immediate danger to animal populations. We have successfully engineered two model plants, Arabidopsis and tobacco, to use the bacterial merB gene to convert methylmercury to less toxic ionic mercury and to use the bacterial merA gene to further detoxify ionic mercury to the least toxic form of mercury, metallic mercury. Plants expressing both MerA and MerB proteins detoxify methylmercury in two steps to the metallic form. These plants germinate, grow, and set seed at normal growth rates on levels of methylmercury or ionic mercury that are lethal to normal plants. Our newest efforts involve engineering plants with several additional bacterial and plant genes that allow for higher levels of mercury resistance and mercury hyperaccumulation. The potential for these plants to hyperaccumulate mercury was further advanced by developing constitutive, aboveground, and root-specific gene expression systems. Our current strategy is to engineer plants to

  10. Augustus as Mercury at last

    Directory of Open Access Journals (Sweden)

    Paulo Martins

    2017-07-01

    Full Text Available My purpose in this paper is to investigate and to analyse the representation of Augustus as Mercury, and what this association may suggest and mean to the Romans from both the urbs and the prouinciae, focusing the epigraphy, the numismatic, and the literature. Furthermore, I review three researches that someway work this problem: Bandinelli, Zanker and Martins. Even though the associations between divinities and rulers were very common – Augustus represented as Apollo, Jupiter or Neptune; Tiberius as Apollo; Claudius as Jupiter; or Commodus as Hercules –, the discussion on the relationship between Augustus and Mercury is very rare in recent bibliography. The latest relevant research on this subject dates back to the first half of the twentieth century. Chittenden’s work on numismatic and Grether’s article on epigraphy are both very important. Thus, new evidences must be considered, so that we can further investigate these representations in the Roman world.

  11. The Messenger Mission to Mercury

    CERN Document Server

    Domingue, D. L

    2007-01-01

    NASA’s MESSENGER mission, launched on 3 August, 2004 is the seventh mission in the Discovery series. MESSENGER encounters the planet Mercury four times, culminating with an insertion into orbit on 18 March 2011. It carries a comprehensive package of geophysical, geological, geochemical, and space environment experiments to complete the complex investigations of this solar-system end member, which begun with Mariner 10. The articles in this book, written by the experts in each area of the MESSENGER mission, describe the mission, spacecraft, scientific objectives, and payload. The book is of interest to all potential users of the data returned by the MESSENGER mission, to those studying the nature of the planet Mercury, and by all those interested in the design and implementation of planetary exploration missions.

  12. Assessing the Behavior of Typically Lithophile Elements Under Highly Reducing Conditions Relevant to the Planet Mercury

    Science.gov (United States)

    Rowland, Rick, II; Vander Kaaden, Kathleen E.; McCubbin, Francis M.; Danielson, Lisa R.

    2017-01-01

    With the data returned from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission, there are now numerous constraints on the physical and chemical properties of Mercury, including its surface composition. The high Sand low FeO contents observed from MESSENGER suggest a low oxygen fugacity of the present materials on the planet's surface. Most of our understanding of elemental partitioning behavior comes from observations made on terrestrial rocks, but Mercury's oxygen fugacity is far outside the conditions of those samples, estimated at approximately 3-7 log units below the Iron-Wtistite (lW) oxygen buffer, several orders of magnitude more reducing than other terrestrial bodies we have data from. With limited oxygen available, lithophile elements may instead exhibit chalcophile, halophile, or siderophile behaviors. Furthermore, very few natural samples of rocks that formed under reducing conditions (e.g., enstatite chondrites, achondrites, aubrites) are available in our collections for examination of this change in geochemical affinity. Our goal is to determine the elemental partitioning behavior of typically lithophile elements at lower oxygen fugacity as a function of temperature and pressure. Experiments were conducted at I GPa in a 13 mm QUICKpress piston cylinder and at 4 GPa in an 880-ton multianvil press, at temperatures up to 1850degC. The composition of starting materials for the experiments were designed so the final run products contained metal, silicate melt, and sulfide melt phases. Oxygen fugacity was controlled in the experiments by adding silicon metal to the samples, in order to utilize the Si-Si02 buffer, which is approximately 5 log units more reducing than the IW buffer at our temperatures of interest. The target silicate melt composition was diopside (CaMgSi206) because measured surface compositions indicate partial melting of a pyroxene-rich mantle. The results of our experiments will aid in our understanding of

  13. METHYL MERCURY PRODUCTION IN NATURAL-COLLECTED SEDIMENT WITH DIFFERENT GEOCHEMICAL PARAMETERS

    Directory of Open Access Journals (Sweden)

    Markus T. Lasut

    2010-06-01

    Full Text Available Production of methyl mercury (MeHg has been shown in laboratory experiments using mercuric chloride (HgCl2 compound released into natural-collected sediments with different geochemical conditions. While the HgCl2 concentration was 30 µl of 113 ppm of HgCl2, the geochemical conditions [pH, salinity, total organic content (TOC, sulfur] of sampled sediments were A: 8.20, 0.00 ppt, 1.97%, and 0.92 ppt, respectively; B: 7.90, 2.00 ppt, 4.69%, and 1.98 ppt, respectively; and C: 8.20, 24.00 ppt, 1.32 %, and 90.90 ppt, respectively. A control was set with no HgCl2. Samples and control were incubated in room temperature of 27 ± 1 °C. Observations were done along 9 days with interval of 3 days. While total Hg was measured using mercury analyzer with Cold Vapor-Atomic Absorbtion Spectrophometer (CV-AAS system, MeHg was measured by using a gas chromatograph with ECD detector after extracted by dithizone-sodium sulfide extraction method. The result shows that MeHg was found in both treatment and control experiments. The concentrations of the MeHg varied according to the geochemical condition of the sampled sediments. Peak production of MeHg occurred on the third day; however, the production was not significantly affected by the incubation time. Optimum production was found inversely related to the pH, in which highest and lowest the pH formed an ineffectively methylated mercury species. The TOC was significantly correlated to the optimum production. Salinity and sulfate contents were found not correlated to the optimum of MeHg production.   Keywords: Methyl mercury; methylation process; sediment; biogeochemistry

  14. Thiosulfate leaching of gold from sulfide wastes

    Energy Technology Data Exchange (ETDEWEB)

    Block-Bolten, A.; Torma, A.E.

    1986-07-01

    The kinetics of gold extraction from lead-zinc sulfide flotation tailings by thiosulfate leachants has been investigated. The order of reaction as well as the overall reaction rate constant were, with respect to thiosulfate concentration, calculated to be n=0.75 and k=1.05 x 10/sup -6/ mol/sup 1/4/ dm/sup 5/4/ min/sup -1/. The apparent activation energy was found to be ..delta..E/sub a/=48.53 kJ and the frequency factor A=7.5 x 10/sup 2/ mol dm/sup -3/ min/sup -1/. This activation energy value suggests chemical control of the reaction mechanism. Optimum leach temperature of 50/sup 0/C was established. Gold extractions as high as 99% have been realized in two step countercurrent leachings. Change in pH throughout the leaching process was found to be an excellent indicator for the progress of the extraction. A preliminary economic evaluation of the process is given.

  15. Luminescent sulfides of monovalent and trivalent cations

    International Nuclear Information System (INIS)

    1975-01-01

    The invention discloses a family of luminescent materials or phosphors having a rhombohedral crystal structure and consisting essentially of a mixed host sulfide of at least one monovalent host cation and at least one trivalent host cation, and containing, for each mole of phosphor, 0.0005 to 0.05 mole of at least one activating cation. The monovalent host cations may be Na, K or Rb and Cs. The trivalent host cations may be Gd, La, Lu, Sc and Y. The activating cations may be one or more of trivalent As, Bi, Ce, Dy, Er, Pr, Sb, Sm, Tb and Tm; divalent Lu, Mn, Pb and Sn; and monovalent Ag, Cu and Tl. The novel phosphors may be used in devices to convert electron-beam, ultraviolet or x-ray energy to light in the visible spectrum. Such energy conversion can be employed for example in fluoroscopic screens, and in viewing screens of cathode-ray tubes and other electron tubes

  16. Comparison of Carbon XANES Spectra from an Iron Sulfide from Comet Wild 2 with an Iron Sulfide Interplanetary Dust Particle

    Science.gov (United States)

    Wirick, S.; Flynn, G. J.; Keller, L. P.; Sanford, S. A.; Zolensky, M. E.; Messenger, Nakamura K.; Jacobsen, C.

    2008-01-01

    Among one of the first particles removed from the aerogel collector from the Stardust sample return mission was an approx. 5 micron sized iron sulfide. The majority of the spectra from 5 different sections of this particle suggests the presence of aliphatic compounds. Due to the heat of capture in the aerogel we initially assumed these aliphatic compounds were not cometary but after comparing these results to a heated iron sulfide interplanetary dust particle (IDP) we believe our initial interpretation of these spectra was not correct. It has been suggested that ice coating on iron sulfides leads to aqueous alteration in IDP clusters which can then lead to the formation of complex organic compounds from unprocessed organics in the IDPs similar to unprocessed organics found in comets [1]. Iron sulfides have been demonstrated to not only transform halogenated aliphatic hydrocarbons but also enhance the bonding of rubber to steel [2,3]. Bromfield and Coville (1997) demonstrated using Xray photoelectron spectroscopy that "the surface enhancement of segregated sulfur to the surface of sulfided precipitated iron catalysts facilitates the formation of a low-dimensional structure of extraordinary properties" [4]. It may be that the iron sulfide acts in some way to protect aliphatic compounds from alteration due to heat.

  17. The Chemical Composition of Mercury

    OpenAIRE

    Nittler, Larry R.; Chabot, Nancy L.; Grove, Timothy L.; Peplowski, Patrick N.

    2017-01-01

    The chemical composition of a planetary body reflects its starting conditions modified by numerous processes during its formation and geological evolution. Measurements by X-ray, gamma-ray, and neutron spectrometers on the MESSENGER spacecraft revealed Mercury's surface to have surprisingly high abundances of the moderately volatile elements sodium, sulfur, potassium, chlorine, and thorium, and a low abundance of iron. This composition rules out some formation models for which high temperatur...

  18. Multiscale geomorphometric modeling of Mercury

    Science.gov (United States)

    Florinsky, I. V.

    2018-02-01

    Topography is one of the key characteristics of a planetary body. Geomorphometry deals with quantitative modeling and analysis of the topographic surface and relationships between topography and other natural components of landscapes. The surface of Mercury is systematically studied by interpretation of images acquired during the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission. However, the Mercurian surface is still little explored by methods of geomorphometry. In this paper, we evaluate the Mercury MESSENGER Global DEM MSGR_DEM_USG_SC_I_V02 - a global digital elevation model (DEM) of Mercury with the resolution of 0.015625° - as a source for geomorphometric modeling of this planet. The study was performed at three spatial scales: the global, regional (the Caloris basin), and local (the Pantheon Fossae area) ones. As the initial data, we used three DEMs of these areas with resolutions of 0.25°, 0.0625°, and 0.015625°, correspondingly. The DEMs were extracted from the MESSENGER Global DEM. From the DEMs, we derived digital models of several fundamental morphometric variables, such as: slope gradient, horizontal curvature, vertical curvature, minimal curvature, maximal curvature, catchment area, and dispersive area. The morphometric maps obtained represent peculiarities of the Mercurian topography in different ways, according to the physical and mathematical sense of a particular variable. Geomorphometric models are a rich source of information on the Mercurian surface. These data can be utilized to study evolution and internal structure of the planet, for example, to visualize and quantify regional topographic differences as well as to refine geological boundaries.

  19. Chelation Therapy for Mercury Poisoning

    OpenAIRE

    Rong Guan; Han Dai

    2009-01-01

    Chelation therapy has been the major treatment for heavy metal poisoning. Various chelating agents have been developed and tested for treatment of heavy metal intoxications, including mercury poisoning. It has been clearly shown that chelating agents could rescue the toxicity caused by heavy metal intoxication, but the potential preventive role of chelating agents against heavy metal poisoning has not been explored much. Recent paper by Siddiqi and colleagues has suggested a protective role o...

  20. Toward a Unified Understanding of Mercury and Methylated Mercury from the World's Oceans

    Science.gov (United States)

    McNutt, M. K.; Krabbenhoft, D. P.; Landing, W. M.; Sunderland, E. M.

    2012-12-01

    Marine fish and shellfish are the main source of toxic methylmercury exposure for humans. As recently as decade ago, very limited aqueous methylated mercury data were available from marine settings, resulting in a generally poor understanding of the processes controlling mercury in pelagic marine food webs. Recent oceanographic cruises have significantly improved availability of reliable measurements of methylated mercury and total mercury in seawater. This presentation will focus on vertical seawater profiles collected to depths 1000 m from three recent sampling efforts in collaboration with the CLIVAR Repeat Hydrography Program sponsored by NOAA including: 1) the northeastern Pacific (P16N cruise from Honolulu, Hawaii to Kodiak, Alaska); (2) the southern Indian Ocean (I5 cruise from Cape Town, South Africa, to Fremantle, Australia); and, (3) the Southern Ocean cruise (S4P from McMurdo, Antarctica, to Punta Arenas, Chile). Analytical results presented were all derived from the USGS Mercury Research Lab (http://wi.water.usgs.gov/mercury-lab). Supporting data derived from these cruises on water mass ages, nutrients, carbon and dissolved oxygen provide an opportunity to develop a stronger understanding of the biogeochemical factors controlling oceanic distributions of mercury and methylated mercury. Whole-water, median total mercury, and methylated mercury concentrations for the northern Pacific, southern Indian, and Southern Ocean were 1.10, 0.80, and 1.65 pM, , and 0.11, 0.08, and 0.32 pM, respectively. For all three oceans, vertical profiles of total mercury generally show the lowest concentrations in the surface mixed layer, and concentration maxima at the 700-1000 m depths. Surface depletion of total mercury is attributed to photo-chemical reduction and evasion of gaseous elemental mercury as well as scavenging by settling particulate matter, the main vector of transport to the subsurface ocean. Methylated mercury in all the ocean profiles reveal distinct mid

  1. Adsorption of sulfide ions on cerussite surfaces and implications for flotation

    International Nuclear Information System (INIS)

    Feng, Qicheng; Wen, Shuming; Zhao, Wenjuan; Deng, Jiushuai; Xian, Yongjun

    2016-01-01

    Highlights: • A new discussion on the lead sulfide species is introduced. • The Na_2S concentration determines cerussite sulfidization. • The activity of lead sulfide species also determines cerussite sulfidization. • Disulfide and polysulfide in lead sulfide species affect its activity. - Abstract: The adsorption of sulfide ions on cerussite surfaces and implications for flotation were studied by X-ray photoelectron spectroscopy (XPS) analysis, micro-flotation tests, and surface adsorption experiments. The XPS analysis results indicated that lead sulfide species formed on the mineral surface after treatment by Na_2S, and the increase in the Na_2S concentration was beneficial for sulfidization. In addition to the content of lead sulfide species, its activity, which was determined by the proportion of sulfide, disulfide and polysulfide, also played an important role in cerussite sulfidization. Micro-flotation tests results demonstrated that insufficient or excessive addition of Na_2S in pulp solutions has detrimental effects on flotation performance, which was attributed to the dosage of Na_2S and the activity of lead sulfide species formed on the mineral surface. Surface adsorption experiments of sulfide ions determined the residual S concentrations in pulp solutions and provided a quantitative illustration for the inhibition of cerussite flotation by excessive sulfide ions. Moreover, it also revealed that sulfide ions in the pulp solution were transformed onto the mineral surface and formed lead sulfide species. These results showed that both of lead sulfide species and its activity acted as an important role in sulfidization flotation process of cerussite.

  2. Adsorption of sulfide ions on cerussite surfaces and implications for flotation

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Qicheng [State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming 650093 (China); Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 650093 (China); Wen, Shuming, E-mail: fqckmust@126.com [State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming 650093 (China); Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 650093 (China); Zhao, Wenjuan [Kunming Metallurgical Research Institute, Kunming 650031 (China); Deng, Jiushuai; Xian, Yongjun [State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming 650093 (China); Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 650093 (China)

    2016-01-01

    Highlights: • A new discussion on the lead sulfide species is introduced. • The Na{sub 2}S concentration determines cerussite sulfidization. • The activity of lead sulfide species also determines cerussite sulfidization. • Disulfide and polysulfide in lead sulfide species affect its activity. - Abstract: The adsorption of sulfide ions on cerussite surfaces and implications for flotation were studied by X-ray photoelectron spectroscopy (XPS) analysis, micro-flotation tests, and surface adsorption experiments. The XPS analysis results indicated that lead sulfide species formed on the mineral surface after treatment by Na{sub 2}S, and the increase in the Na{sub 2}S concentration was beneficial for sulfidization. In addition to the content of lead sulfide species, its activity, which was determined by the proportion of sulfide, disulfide and polysulfide, also played an important role in cerussite sulfidization. Micro-flotation tests results demonstrated that insufficient or excessive addition of Na{sub 2}S in pulp solutions has detrimental effects on flotation performance, which was attributed to the dosage of Na{sub 2}S and the activity of lead sulfide species formed on the mineral surface. Surface adsorption experiments of sulfide ions determined the residual S concentrations in pulp solutions and provided a quantitative illustration for the inhibition of cerussite flotation by excessive sulfide ions. Moreover, it also revealed that sulfide ions in the pulp solution were transformed onto the mineral surface and formed lead sulfide species. These results showed that both of lead sulfide species and its activity acted as an important role in sulfidization flotation process of cerussite.

  3. Chemical and colloidal aspects of collectorless flotation behavior of sulfide and non-sulfide minerals.

    Science.gov (United States)

    Aghazadeh, Sajjad; Mousavinezhad, Seyed Kamal; Gharabaghi, Mahdi

    2015-11-01

    Flotation has been widely used for separation of valuable minerals from gangues based on their surface characterizations and differences in hydrophobicity on mineral surfaces. As hydrophobicity of minerals widely differs from each other, their separation by flotation will become easier. Collectors are chemical materials which are supposed to make selectively valuable minerals hydrophobic. In addition, there are some minerals which based on their surface and structural features are intrinsically hydrophobic. However, their hydrophobicities are not strong enough to be floatable in the flotation cell without collectors such as sulfide minerals, coal, stibnite, and so forth. To float these minerals in a flotation cell, their hydrophobicity should be increased in specific conditions. Various parameters including pH, Eh, size distribution, mill types, mineral types, ore characterization, and type of reaction in flotation cells affect the hydrophobicity of minerals. Surface analysis results show that when sulfide minerals experience specific flotation conditions, the reactions on the surface of these minerals increase the amount of sulfur on the surface. These phenomenons improve the hydrophobicity of these minerals due to strong hydrophobic feature of sulfurs. Collectorless flotation reduces chemical material consumption amount, increases flotation selectivity (grade increases), and affects the equipment quantities; however, it can also have negative effects. Some minerals with poor surface floatability can be increased by adding some ions to the flotation system. Depressing undesirable minerals in flotation is another application of collectorless flotation.

  4. Silver sulfide nanoparticle assembly obtained by reacting an assembled silver nanoparticle template with hydrogen sulfide gas.

    Science.gov (United States)

    Chen, Rui; Nuhfer, Noel T; Moussa, Laura; Morris, Hannah R; Whitmore, Paul M

    2008-11-12

    A fast, simple procedure is described for obtaining an assembly of silver sulfide nanoparticles (Ag(2)S NPs) on a glass substrate through reaction of a template of an assembled layer of silver nanoparticles (Ag NPs) with hydrogen sulfide (H(2)S) gas. The Ag NP template was prepared by assembling a monolayer of spherical Ag NPs (mean diameter of 7.4 nm) on a polyethylenimine-treated glass substrate. Exposure to pure H(2)S for 10 min converted the Ag NPs of the template to Ag(2)S NPs. The resulting Ag(2)S NP assembly, which retains the template nanostructure and particle distribution, was characterized by optical absorption spectroscopy, atomic force microscopy, transmission electron microscopy (TEM), scanning high resolution TEM, energy dispersive x-ray spectroscopy and x-ray photoelectron spectroscopy. The Ag(2)S NPs have a crystal structure of monoclinic acanthite, and while they retained the spherical shape of the original Ag NPs, their mean particle size increased to 8.4 nm due to changes to the crystal structure when the Ag NPs are converted into Ag(2)S NPs. The measured optical absorption edge of the Ag(2)S NP assembly indicated an indirect interband transition with a band gap energy of 1.71 eV. The Ag(2)S NP assembly absorbed light with wavelengths below 725 nm, and the absorbance increased monotonically toward the UV region.

  5. Maternal transfer of mercury to songbird eggs.

    Science.gov (United States)

    Ackerman, Joshua T; Hartman, C Alex; Herzog, Mark P

    2017-11-01

    We evaluated the maternal transfer of mercury to eggs in songbirds, determined whether this relationship differed between songbird species, and developed equations for predicting mercury concentrations in eggs from maternal blood. We sampled blood and feathers from 44 house wren (Troglodytes aedon) and 34 tree swallow (Tachycineta bicolor) mothers and collected their full clutches (n = 476 eggs) within 3 days of clutch completion. Additionally, we sampled blood and feathers from 53 tree swallow mothers and randomly collected one egg from their clutches (n = 53 eggs) during mid to late incubation (6-10 days incubated) to evaluate whether the relationship varied with the timing of sampling the mother's blood. Mercury concentrations in eggs were positively correlated with mercury concentrations in maternal blood sampled at (1) the time of clutch completion for both house wrens (R 2  = 0.97) and tree swallows (R 2  = 0.97) and (2) during mid to late incubation for tree swallows (R 2  = 0.71). The relationship between mercury concentrations in eggs and maternal blood did not differ with the stage of incubation when maternal blood was sampled. Importantly, the proportion of mercury transferred from mothers to their eggs decreased substantially with increasing blood mercury concentrations in tree swallows, but increased slightly with increasing blood mercury concentrations in house wrens. Additionally, the proportion of mercury transferred to eggs at the same maternal blood mercury concentration differed between species. Specifically, tree swallow mothers transferred 17%-107% more mercury to their eggs than house wren mothers over the observed mercury concentrations in maternal blood (0.15-1.92 μg/g ww). In contrast, mercury concentrations in eggs were not correlated with those in maternal feathers and, likewise, mercury concentrations in maternal blood were not correlated with those in feathers (all R 2  mercury concentrations from maternal blood to eggs

  6. Worldwide trend of atmospheric mercury since 1995

    Directory of Open Access Journals (Sweden)

    F. Slemr

    2011-05-01

    Full Text Available Concern about the adverse effects of mercury on human health and ecosystems has led to tightening emission controls since the mid 1980s. But the resulting mercury emissions reductions in many parts of the world are believed to be offset or even surpassed by the increasing emissions in rapidly industrializing countries. Consequently, concentrations of atmospheric mercury are expected to remain roughly constant. Here we show that the worldwide atmospheric mercury concentrations have decreased by about 20 to 38 % since 1996 as indicated by long-term monitoring at stations in the Southern and Northern Hemispheres combined with intermittent measurements of latitudinal distribution over the Atlantic Ocean. The total reduction of the atmospheric mercury burden of this magnitude within 14 years is unusually large among most atmospheric trace gases and is at odds with the current mercury emission inventories with nearly constant anthropogenic emissions over this period. This suggests a major shift in the biogeochemical cycle of mercury including oceans and soil reservoirs. Decreasing reemissions from the legacy of historical mercury emissions are the most likely explanation for this decline since the hypothesis of an accelerated oxidation rate of elemental mercury in the atmosphere is not supported by the observed trends of other trace gases. Acidification of oceans, climate change, excess nutrient input and pollution may also contribute by their impact on the biogeochemistry of ocean and soils. Consequently, models of the atmospheric mercury cycle have to include soil and ocean mercury pools and their dynamics to be able to make projections of future trends.

  7. Recovery of Mercury From Contaminated Liquid Wastes

    International Nuclear Information System (INIS)

    1998-01-01

    The Base Contract program emphasized the manufacture and testing of superior sorbents for mercury removal, testing of the sorption process at a DOE site, and determination of the regeneration conditions in the laboratory. During this project, ADA Technologies, Inc. demonstrated the following key elements of a successful regenerable mercury sorption process: (1) sorbents that have a high capacity for dissolved, ionic mercury; (2) removal of ionic mercury at greater than 99% efficiency; and (3) thermal regeneration of the spent sorbent. ADA's process is based on the highly efficient and selective sorption of mercury by noble metals. Contaminated liquid flows through two packed columns that contain microporous sorbent particles on which a noble metal has been finely dispersed. A third column is held in reserve. When the sorbent is loaded with mercury to the point of breakthrough at the outlet of the second column, the first column is taken off-line and the flow of contaminated liquid is switched to the second and third columns. The spent column is regenerated by heating. A small flow of purge gas carries the desorbed mercury to a capture unit where the liquid mercury is recovered. Laboratory-scale tests with mercuric chloride solutions demonstrated the sorbents' ability to remove mercury from contaminated wastewater. Isotherms on surrogate wastes from DOE's Y-12 Plant in Oak Ridge, Tennessee showed greater than 99.9% mercury removal. Laboratory- and pilot-scale tests on actual Y-12 Plant wastes were also successful. Mercury concentrations were reduced to less than 1 ppt from a starting concentration of 1,000 ppt. The treatment objective was 50 ppt. The sorption unit showed 10 ppt discharge after six months. Laboratory-scale tests demonstrated the feasibility of sorbent regeneration. Results show that sorption behavior is not affected after four cycles

  8. Mercury(II) and methyl mercury speciation on Streptococcus pyogenes loaded Dowex Optipore SD-2

    International Nuclear Information System (INIS)

    Tuzen, Mustafa; Uluozlu, Ozgur Dogan; Karaman, Isa; Soylak, Mustafa

    2009-01-01

    A solid phase extraction procedure based on speciation of mercury(II) and methyl mercury on Streptococcus pyogenes immobilized on Dowex Optipore SD-2 has been established. Selective and sequential elution with 0.1 mol L -1 HCl for methyl mercury and 2 mol L -1 HCl for mercury(II) were performed at pH 8. The determination of mercury levels was performed by cold vapour atomic absorption spectrometry (CVAAS). Optimal analytical conditions including pH, amounts of biosorbent, sample volumes, etc., were investigated. The influences of the some alkaline and earth alkaline ions and some transition metals on the recoveries were also investigated. The capacity of biosorbent for mercury(II) and methyl mercury was 4.8 and 3.4 mg g -1 . The detection limit (3 sigma) of the reagent blank for mercury(II) and methyl mercury was 2.1 and 1.5 ng L -1 . Preconcentration factor was calculated as 25. The relative standard deviations of the procedure were below 7%. The validation of the presented procedure is performed by the analysis of standard reference material (NRCC-DORM 2 Dogfish Muscle). The procedure was successfully applied to the speciation of mercury(II) and methyl mercury in natural water and environmental samples.

  9. Mercury(II) and methyl mercury speciation on Streptococcus pyogenes loaded Dowex Optipore SD-2

    Energy Technology Data Exchange (ETDEWEB)

    Tuzen, Mustafa, E-mail: m.tuzen@gmail.com [Gaziosmanpasa University, Faculty of Science and Arts, Chemistry Department, 60250 Tokat (Turkey); Uluozlu, Ozgur Dogan [Gaziosmanpasa University, Faculty of Science and Arts, Chemistry Department, 60250 Tokat (Turkey); Karaman, Isa [Gaziosmanpasa University, Faculty of Science and Arts, Biology Department, 60250 Tokat (Turkey); Soylak, Mustafa [Erciyes University, Faculty of Science and Arts, Chemistry Department, 38039 Kayseri (Turkey)

    2009-09-30

    A solid phase extraction procedure based on speciation of mercury(II) and methyl mercury on Streptococcus pyogenes immobilized on Dowex Optipore SD-2 has been established. Selective and sequential elution with 0.1 mol L{sup -1} HCl for methyl mercury and 2 mol L{sup -1} HCl for mercury(II) were performed at pH 8. The determination of mercury levels was performed by cold vapour atomic absorption spectrometry (CVAAS). Optimal analytical conditions including pH, amounts of biosorbent, sample volumes, etc., were investigated. The influences of the some alkaline and earth alkaline ions and some transition metals on the recoveries were also investigated. The capacity of biosorbent for mercury(II) and methyl mercury was 4.8 and 3.4 mg g{sup -1}. The detection limit (3 sigma) of the reagent blank for mercury(II) and methyl mercury was 2.1 and 1.5 ng L{sup -1}. Preconcentration factor was calculated as 25. The relative standard deviations of the procedure were below 7%. The validation of the presented procedure is performed by the analysis of standard reference material (NRCC-DORM 2 Dogfish Muscle). The procedure was successfully applied to the speciation of mercury(II) and methyl mercury in natural water and environmental samples.

  10. Activation mechanism of ammonium ions on sulfidation of malachite (-201) surface by DFT study

    Science.gov (United States)

    Wu, Dandan; Mao, Yingbo; Deng, Jiushuai; Wen, Shuming

    2017-07-01

    The activation mechanism of ammonium ions on the sulfidation of malachite (-201) was determined by density functional theory (DFT) calculations. Results of DFT calculations indicated that interlayer sulfidation occurs during the sulfidation process of malachite (-201). The absorption of both the ammonium ion and sulfide ion on the malachite (-201) surface is stronger than that of sulfur ion. After sulfidation was activated with ammonium ion, the Cu 3d orbital peak is closer to the Fermi level and characterized by a stronger peak value. Therefore, the addition of ammonium ions activated the sulfidation of malachite (-201), thereby improving the flotation performance.

  11. Human Exposure and Health Effects of Inorganic and Elemental Mercury

    Science.gov (United States)

    Zheng, Wei

    2012-01-01

    Mercury is a toxic and non-essential metal in the human body. Mercury is ubiquitously distributed in the environment, present in natural products, and exists extensively in items encountered in daily life. There are three forms of mercury, i.e., elemental (or metallic) mercury, inorganic mercury compounds, and organic mercury compounds. This review examines the toxicity of elemental mercury and inorganic mercury compounds. Inorganic mercury compounds are water soluble with a bioavailability of 7% to 15% after ingestion; they are also irritants and cause gastrointestinal symptoms. Upon entering the body, inorganic mercury compounds are accumulated mainly in the kidneys and produce kidney damage. In contrast, human exposure to elemental mercury is mainly by inhalation, followed by rapid absorption and distribution in all major organs. Elemental mercury from ingestion is poorly absorbed with a bioavailability of less than 0.01%. The primary target organs of elemental mercury are the brain and kidney. Elemental mercury is lipid soluble and can cross the blood-brain barrier, while inorganic mercury compounds are not lipid soluble, rendering them unable to cross the blood-brain barrier. Elemental mercury may also enter the brain from the nasal cavity through the olfactory pathway. The blood mercury is a useful biomarker after short-term and high-level exposure, whereas the urine mercury is the ideal biomarker for long-term exposure to both elemental and inorganic mercury, and also as a good indicator of body burden. This review discusses the common sources of mercury exposure, skin lightening products containing mercury and mercury release from dental amalgam filling, two issues that happen in daily life, bear significant public health importance, and yet undergo extensive debate on their safety. PMID:23230464

  12. Rapid Monitoring of Mercury in Air from an Organic Chemical Factory in China Using a Portable Mercury Analyzer

    Directory of Open Access Journals (Sweden)

    Akira Yasutake

    2011-01-01

    Full Text Available A chemical factory, using a production technology of acetaldehyde with mercury catalysis, was located southeast of Qingzhen City in Guizhou Province, China. Previous research showed heavy mercury pollution through an extensive downstream area. A current investigation of the mercury distribution in ambient air, soils, and plants suggests that mobile mercury species in soils created elevated mercury concentrations in ambient air and vegetation. Mercury concentrations of up to 600 ng/m3 in air over the contaminated area provided evidence of the mercury transformation to volatile Hg(0. Mercury analysis of soil and plant samples demonstrated that the mercury concentrations in soil with vaporized and plant-absorbable forms were higher in the southern area, which was closer to the factory. Our results suggest that air monitoring using a portable mercury analyzer can be a convenient and useful method for the rapid detection and mapping of mercury pollution in advanced field surveys.

  13. Sexual differences in the excretion of organic and inorganic mercury by methyl mercury-treated rats

    International Nuclear Information System (INIS)

    Thomas, D.J.; Fisher, H.L.; Sumler, M.R.; Mushak, P.; Hall, L.L.

    1987-01-01

    Adult male and female Long Evans rats received 1 mumole of methyl ( 203 Hg) mercuric chloride per kilogram sc. Whole-body retention of mercury and excretion of organic and inorganic mercury in urine and feces were monitored for 98 days after dosing. Females cleared mercury from the body more rapidly than did males. The major route of mercury excretion was feces. By 98 days after dosing, cumulative mercury excretion in feces accounted for about 51% of the dose in males and about 54% of the dose in females. For both sexes, about 33% of the dose was excreted in feces as inorganic mercury. Cumulative excretion of organic mercury in feces accounted for about 18 and 21% of the dose in males and females, respectively. Urinary excretion of mercury was quantitatively a smaller route for mercury clearance but important sexual differences in loss by this route were found. Over the 98-day experimental period, males excreted in urine about 3.2% of the dose and females excreted 7.5%. Cumulative organic Hg excretion in urine accounted for 1.8% of the dose in males and 5.3% of the dose in females. These sexual differences in urinary and fecal excretion of organic and inorganic mercury following methyl mercury treatment were consistent with previous reports of sexual differences in mercury distribution and retention in methyl mercury-treated rats, particularly sexual differences in organic mercury uptake and retention in the kidney. Relationships between body burdens of organic or inorganic Hg and output of these forms of Hg in urine and feces were also found to be influenced by the interval after MeHg treatment and by sex. Relationship between concentration of Hg in liver and feces and in kidney and urine differed for organic and inorganic Hg and depended upon sexual status and interval after MeHg treatment

  14. Aubrite and Impact Melt Enstatite Chondrite Meteorites as Potential Analogs to Mercury

    Science.gov (United States)

    Wilbur, Z. E.; Udry, A.; Mccubbin, Francis M.; McCubbin, F. M.; Combs, L. M.; Rahib, R. R.; McCoy, C.; McCoy, T. J.

    2018-01-01

    The MESSENGER (MErcury Sur-face, Space ENvironment, GEochemistry and Ranging) orbiter measured the Mercurian surface abundances of key rock-forming elements to help us better understand the planet's surface and bulk geochemistry. A major discovery is that the Mercurian surface and interior are characterized by an extremely low oxygen fugacity (ƒO2; Iron-Wüstite (IW) -7.3 to IW-2.6. This is supported by low Fe and high S abundances on the surface. This low ƒO2 causes a different elemental partioning from what is observed on Earth. Using surface composition, it was shown that the Mercurian surface mainly consists of normative plagioclase, pyroxene, olivine, and exotic sulfides, such as niningerite ((Mg,Mn, Fe)S) and oldhamite (CaS).

  15. A Challenging Case of Acute Mercury Toxicity

    Directory of Open Access Journals (Sweden)

    Ali Nayfeh

    2018-01-01

    Full Text Available Background. Mercury exists in multiple forms: elemental, organic, and inorganic. Its toxic manifestations depend on the type and magnitude of exposure. The role of colonoscopic decompression in acute mercury toxicity is still unclear. We present a case of acute elemental mercury toxicity secondary to mercury ingestion, which markedly improved with colonoscopic decompression. Clinical Case. A 54-year-old male presented to the ED five days after ingesting five ounces (148 cubic centimeters of elemental mercury. Examination was only significant for a distended abdomen. Labs showed elevated serum and urine mercury levels. An abdominal radiograph showed radiopaque material throughout the colon. Succimer and laxatives were initiated. The patient had recurrent bowel movements, and serial radiographs showed interval decrease of mercury in the descending colon with interval increase in the cecum and ascending colon. Colonoscopic decompression was done successfully. The colon was evacuated, and a repeat radiograph showed decreased hyperdense material in the colon. Three months later, a repeat radiograph showed no hyperdense material in the colon. Conclusion. Ingested elemental mercury can be retained in the colon. Although there are no established guidelines for colonoscopic decompression, our patient showed significant improvement. We believe further studies on this subject are needed to guide management practices.

  16. Mercury in tropical and subtropical coastal environments

    Science.gov (United States)

    Costa, Monica F.; Landing, William M.; Kehrig, Helena A.; Barletta, Mário; Holmes, Christopher D.; Barrocas, Paulo R. G.; Evers, David C.; Buck, David G.; Vasconcellos, Ana Claudia; Hacon, Sandra S.; Moreira, Josino C.; Malm, Olaf

    2012-01-01

    Anthropogenic activities influence the biogeochemical cycles of mercury, both qualitatively and quantitatively, on a global scale from sources to sinks. Anthropogenic processes that alter the temporal and spatial patterns of sources and cycling processes are changing the impacts of mercury contamination on aquatic biota and humans. Human exposure to mercury is dominated by the consumption of fish and products from aquaculture operations. The risk to society and to ecosystems from mercury contamination is growing, and it is important to monitor these expanding risks. However, the extent and manner to which anthropogenic activities will alter mercury sources and biogeochemical cycling in tropical and sub-tropical coastal environments is poorly understood. Factors as (1) lack of reliable local/regional data; (2) rapidly changing environmental conditions; (3) governmental priorities and; (4) technical actions from supra-national institutions, are some of the obstacles to overcome in mercury cycling research and policy formulation. In the tropics and sub-tropics, research on mercury in the environment is moving from an exploratory “inventory” phase towards more process-oriented studies. Addressing biodiversity conservation and human health issues related to mercury contamination of river basins and tropical coastal environments are an integral part of paragraph 221 paragraph of the United Nations document “The Future We Want” issued in Rio de Janeiro in June 2012. PMID:22901765

  17. Mercury Sorption onto Malt Spent Rootlets

    Science.gov (United States)

    Manariotis, I. D.; Anagnostopoulos, V.; Karapanagioti, H. K.; Chrysikopoulos, C.

    2011-12-01

    Mercury is a metal of particular concern due to its toxicity even at relatively low concentrations. The maximum permissible level for mercury in drinking water set by the European Union is 0.001 mg/L. Mercury is released into the environment via four principal pathways: (1) natural processes; i.e. a volcanic eruption, (2) incidental to some other activity; i.e. coal burning power plants, (3) accidentally during the manufacture, breakage or disposal of products that have mercury put into them deliberately, and (4) direct use in industrial settings. The present study focuses on the removal of mercury (II) from aqueous solutions via sorption onto Malt Spent Rootlets (MSR). Batch experiments were conducted employing MSR with size ranging from 0.18 to 1 mm. The effects of pH, mercury concentration, contact time, and solid to liquid ratio on mercury sorption onto MSR were investigated. The highest mercury removal from the aqueous phase, of 41%, was observed at pH of 5.

  18. Recent Advances in Atmospheric Chemistry of Mercury

    Directory of Open Access Journals (Sweden)

    Lin Si

    2018-02-01

    Full Text Available Mercury is one of the most toxic metals and has global importance due to the biomagnification and bioaccumulation of organomercury via the aquatic food web. The physical and chemical transformations of various mercury species in the atmosphere strongly influence their composition, phase, transport characteristics and deposition rate back to the ground. Modeling efforts to assess global cycling of mercury require an accurate understanding of atmospheric mercury chemistry. Yet, there are several key uncertainties precluding accurate modeling of physical and chemical transformations. We focus this article on recent studies (since 2015 on improving our understanding of the atmospheric chemistry of mercury. We discuss recent advances in determining the dominant atmospheric oxidant of elemental mercury (Hg0 and understanding the oxidation reactions of Hg0 by halogen atoms and by nitrate radical (NO3—in the aqueous reduction of oxidized mercury compounds (HgII as well as in the heterogeneous reactions of Hg on atmospheric-relevant surfaces. The need for future research to improve understanding of the fate and transformation of mercury in the atmosphere is also discussed.

  19. Episodic bioavailability of environmental mercury: implications for ...

    African Journals Online (AJOL)

    Perennial wildfires in Africa and other continents contribute an estimated 8 x 105 kg of mercury to the global atmosphere with a residence time of approximately one year. This phenomenon changes the flux of biologically available mercury in natural microbial communities where enzymatic actions, including mercuric ...

  20. Increased Mercury Bioaccumulation Follows Water Quality Improvement

    Energy Technology Data Exchange (ETDEWEB)

    Bogle, M.A.; Peterson, M.J.; Smith, J.G.; Southworth, G.R.

    1999-09-15

    Changes in physical and chemical characteristics of aquatic habitats made to reduce or eliminate ecological risks can sometimes have unforeseen consequences. Environmental management activities on the U.S. Dept. of Energy reservation in Oak Ridge, Tennessee,have succeeded in improving water quality in streams impacted by discharges fi-om industrial facilities and waste disposal sites. The diversity and abundance of pollution-sensitive components of the benthic macroinvertebrate communities of three streams improved after new waste treatment systems or remedial actions reduced inputs of various toxic chemicals. Two of the streams were known to be mercury-contaminated from historical spills and waste disposal practices. Waterborne mercury concentrations in the third were typical of uncontaminated systems. In each case, concentrations of mercury in fish, or the apparent biological availability of mercury increased over the period during which ecological metrics indicated improved water quality. In the system where waterborne mercury concentrations were at background levels, increased mercury bioaccumulation was probably a result of reduced aqueous selenium concentrations; however, the mechanisms for increased mercury accumulation in the other two streams remain under investigation. In each of the three systems, reduced inputs of metals and inorganic anions was followed by improvements in the health of aquatic invertebrate communities. However, this reduction in risk to aquatic invertebrates was accompanied by increased risk to humans and piscivorous wildlife related to increased mercury concentrations in fish.

  1. Intentional intravenous mercury injection | Yudelowitz | South African ...

    African Journals Online (AJOL)

    Intravenous mercury injection is rarely seen, with few documented cases. Treatment strategies are not clearly defined for such cases, although a few options do show benefit. This case report describes a 29-year-old man suffering from bipolar disorder, who presented following self-inflicted intravenous injection of mercury.

  2. Mercury soil surveys: a good reconnaissance tool

    Energy Technology Data Exchange (ETDEWEB)

    Stone, C.; Ruscetta, C.A.; Foley, D. (eds.)

    1981-05-01

    Three examples of mercury soil surveys are discussed, along with the gravity data. An excellent correlation was found in southern Arizona between buried structures revealed by gravity and mercury soil surveys. The advantages of the latter over the former as a reconnaissance tool are listed. (MHR)

  3. Increased Mercury Bioaccumulation Follows Water Quality Improvement

    International Nuclear Information System (INIS)

    Bogle, M.A.; Peterson, M.J.; Smith, J.G.; Southworth, G.R.

    1999-01-01

    Changes in physical and chemical characteristics of aquatic habitats made to reduce or eliminate ecological risks can sometimes have unforeseen consequences. Environmental management activities on the U.S. Dept. of Energy reservation in Oak Ridge, Tennessee,have succeeded in improving water quality in streams impacted by discharges fi-om industrial facilities and waste disposal sites. The diversity and abundance of pollution-sensitive components of the benthic macroinvertebrate communities of three streams improved after new waste treatment systems or remedial actions reduced inputs of various toxic chemicals. Two of the streams were known to be mercury-contaminated from historical spills and waste disposal practices. Waterborne mercury concentrations in the third were typical of uncontaminated systems. In each case, concentrations of mercury in fish, or the apparent biological availability of mercury increased over the period during which ecological metrics indicated improved water quality. In the system where waterborne mercury concentrations were at background levels, increased mercury bioaccumulation was probably a result of reduced aqueous selenium concentrations; however, the mechanisms for increased mercury accumulation in the other two streams remain under investigation. In each of the three systems, reduced inputs of metals and inorganic anions was followed by improvements in the health of aquatic invertebrate communities. However, this reduction in risk to aquatic invertebrates was accompanied by increased risk to humans and piscivorous wildlife related to increased mercury concentrations in fish

  4. Anthropogenic mercury deposition to arctic lake sediments

    Energy Technology Data Exchange (ETDEWEB)

    Hermanson, M.H. [Westchester University, Westchester, PA (United States). Dept. of Health

    1998-01-01

    The history of atmospheric mercury inputs to remote arctic regions can be measured in lake sediment cores using lead-210 chronology. In the investigation, total mercury deposition is measured in sediments from Imitavik and Annak Lakes on the Belcher Islands in southeastern Hudson Bay, an area in the southern Canadian Arctic with no history of local industrial or agricultural sources of contamination. Both lakes received background and atmospheric inputs of mercury while Annak also received mercury from raw domestic sewage from the Hamlet of Sanikiluaq, a growing Inuit community of about 550 established in the late 1960s. Results from Imitavik show that anthropogenic mercury inputs, apparently transported through the atmosphere, began to appear in the mid-eighteenth century, and continued to the 1990s. Annak had a similar mercury history until the late 1960s when disposal of domestic sewage led to increased sediment and contaminant accumulation. The high input of mercury to Annak confirms that Sanikiluaq residents are exposed to mercury through native food sources. 39 refs., 7 figs., 3 tabs.

  5. Mercury-free discharges for lighting - editorial

    NARCIS (Netherlands)

    Haverlag, M.

    2007-01-01

    This special Cluster of articles in Journal of Physics D: Applied Physics covers the subject of mercury-free discharges that are being investigated by different light source researchers, as an alternative to existing mercury-containing lamps. The main driving force to move away from

  6. Urban artisanal gold shops and mercury emissions

    International Nuclear Information System (INIS)

    Cordy, P.; Veiga, M.; Carrasco, V.H.G.

    2008-01-01

    Artisanal miners in developing countries use mercury amalgamation processes to extract gold. The amalgams are then refined before being sold on to urban gold shops. The amalgams can often contain between 2 to 40 per cent mercury. Unburned amalgams are also often sold directly to gold shops. There are serious health risks for shop employees and nearby populations when the gold is melted and further purified. Studies have shown that mercury concentrations in the ambient air of gold shops often exceeds World Health Organization (WHO) limits by an order of magnitude or more. This study examined the practices and technologies used to refine gold in Latin America and Indonesia. The study compared and contrasted various refining methods and their resulting mercury emissions. Methods of reducing mercury emissions were also investigated, including a filtration system designed to capture 80 per cent of mercury emissions. Barriers to implementing mercury emissions reduction plans were also investigated. It was concluded that the design of urban gold shops must include condensers, fume hoods, and efficient mercury capture systems. 15 refs

  7. Mercury distribution in Douro estuary (Portugal)

    Energy Technology Data Exchange (ETDEWEB)

    Ramalhosa, E. [Department of Chemistry, University of Aveiro, 3810-193 Aveiro (Portugal); Pereira, E. [Department of Chemistry, University of Aveiro, 3810-193 Aveiro (Portugal)]. E-mail: eduper@dq.ua.pt; Vale, C. [National Institute for Agronomy and Fishery Research, IPIMAR, Avenida Brasilia, 1449-006 Lisboa (Portugal); Valega, M. [Department of Chemistry, University of Aveiro, 3810-193 Aveiro (Portugal); Monterroso, P. [Department of Chemistry, University of Aveiro, 3810-193 Aveiro (Portugal); Duarte, A.C. [Department of Chemistry, University of Aveiro, 3810-193 Aveiro (Portugal)

    2005-11-15

    Determinations of dissolved reactive and total dissolved mercury, particulate and sedimentary mercury, dissolved organic carbon (DOC), particulate organic carbon (POC) and suspended particulate matter (SPM) have been made in the estuary of river Douro, in northern Portugal. The estuary was stratified by salinity along most of its length, it had low concentrations of SPM, typically <20 mg dm{sup -3}, and concentrations of DOC in the range <1.0-1.8 mg dm{sup -3}. The surface waters had a maximum dissolved concentration of reactive mercury of about 10 ng dm{sup -3}, whereas for the more saline bottom waters it was about 65 ng dm{sup -3}. The surface waters had maximum concentrations of total suspended particulate mercury of {approx}7 {mu}g g{sup -1} and the bottom waters were always <1 {mu}g g{sup -1}. Concentrations of mercury in sediments was low and in the range from 0.06 to 0.18 {mu}g g{sup -1}. The transport of mercury in surface waters was mainly associated with organic-rich particulate matter, while in bottom waters the dissolved phase transport of mercury is more important. Lower particulate organic matter, formation of chlorocomplexes in more saline waters and eventually the presence of colloids appear to explain the difference of mercury partitioning in Douro estuarine waters.

  8. Mercury cycling in peatland watersheds. Chapter 11.

    Science.gov (United States)

    Randall K. Kolka; Carl P.J. Mitchell; Jeffrey D. Jeremiason; Neal A. Hines; David F. Grigal; Daniel R. Engstrom; Jill K. Coleman-Wasik; Edward A. Nater; Edward B. Swain; Bruce A. Monson; Jacob A. Fleck; Brian Johnson; James E. Almendinger; Brian A. Branfireun; Patrick L. Brezonik; James B. Cotner

    2011-01-01

    Mercury (Hg) is of great environmental concern due to its transformation into the toxic methylmercury (MeHg) form that bioaccumulates within the food chain and causes health concerns for both humans and wildlife (U.S. Environmental Protection Agency 2002). Mercury can affect neurological development in fetuses and young children. In adults, exposure to Hg can lead to...

  9. EURISOL MERCURY TARGET EXPERIMENT: CERN SAFETY REPORT

    CERN Document Server

    J. Gulley (CERN SC/GS)

    Report on a visit to the mercury-handling lab at IPUL. The aim was to provide recommendations to IPUL on general health and safety issues relatring to the handling of mercury, the objective being to reduce exposure to acceptable levels, so far as is reasonably practical.

  10. Pneumonitis after Inhalation of Mercury Vapours

    Directory of Open Access Journals (Sweden)

    JD Glezos

    2006-01-01

    Full Text Available A 43-year-old man presented to hospital with pneumonia but only after discharge from hospital did he admit to deliberate prior inhalation of mercury. His pulmonary involvement appeared to resolve almost completely with antibiotics and supportive care. Nevertheless, persisting elevated urinary excretion of mercury required two courses of chelation therapy. No serious systemic sequelae were observed.

  11. Mercury poisoning | Shamley | South African Medical Journal

    African Journals Online (AJOL)

    The diagnosis of mercury poisoning requires a high index of suspicion. Mercury poisoning in a patient involved in illicit gold extraction is reported and 6 other cases considered. Some of the clinical features and treatment of this condition are discussed. S Afr Med J 1989; 76: 114-116 ...

  12. Cuprous sulfide as a film insulation for superconductors

    International Nuclear Information System (INIS)

    Wagner, G.R.; Uphoff, J.H.; Vecchio, P.D.

    1982-01-01

    The LCP test coil utilizes a conductor of forced-flow design having 486 strands of multifilametary Nb 3 Sn compacted in a stainless steel sheath. The impetus for the work reported here stemmed from the need for some form of insulation for those strands to prevent sintering during reaction and to reduce ac losses. The work reported here experimented with cuprous sulfide coatings at various coating rates and thicknesses. Two solenoids that were wound with cuprous sulfide-coated wires and heat-treated at 700 degrees C were found to demonstrate that the film is effective in providing turn-to-turn insulation for less than about 0.5V between turns. The sulfide layer provided a metal-semiconductor junction which became conducting at roughly 0.5V. Repeated cycling of the coil voltage in excess of that value produced no damage to the sulfide layer. The junction provided self-protection for the coil as long as the upper allowable current density in the sulfide was not exceeded. No training was apparent up to 6.4 T

  13. Sulfide Species Optical Monitoring by a Miniaturized Silicon Photomultiplier

    Directory of Open Access Journals (Sweden)

    Salvatore Petralia

    2018-02-01

    Full Text Available The monitoring of water-soluble pollutants is receiving a growing interest from the scientific community. In this context, sulfide anion species S2− and HS− are particularly relevant since they can cause acute and chronic toxicity including neurological effects and at high concentrations, even death. In this study, a new strategy for fast and sensitive optical detection of sulfide species in water samples is described. The method uses an integrated silicon photomultiplier (SiPM device coupled with the appropriate analytical strategy applied in a plastic microchip with dried reagents on board. More specifically, all sulfide species (H2S, HS− and S2− in water samples are detected by the fluorescence signal emitted upon the reaction with N,N-dimethyl-phenylenediamine sulfate in the presence of Fe3+, leading to the formation of the fluorescent methylene blue (MB species. It has been proven that the system herein proposed is able to measure sulfide concentration in a linear range from 0–10 mg L−1 with a sensitivity value of about 6.7 µA mg−1 L and a detection limit of 0.5 mg L−1. A comparison with conventional UV-Vis detection method has been also carried out. Data show a very good linear correlation (R2 = 0.98093, proving the effectiveness of the method. Results pave the way toward the development of portable and low-cost device systems for water-soluble sulfide pollutants.

  14. Mercury in a coastal marine environment

    Energy Technology Data Exchange (ETDEWEB)

    Burton, J D; Leatherland, T M

    1971-06-18

    The problem of mercury pollution was investigated in Southampton Water and the English Channel. Mercury was determined in five specimens of the mollusk, Mercenaria mercenaria. The concentrations in whole organisms, without shell, ranged from 0.18 to 0.57 p.p.m. The amounts of mercury in the river and estuarine waters were found to be low. Yet, samples from the surface of the bottom mud in different parts of the estuary had mercury contents ranging from 0.19 to 0.64 p.p.m. The role of sediments in the transport of mercury in food chains could be significant, particularly for bottom living, suspension feeding animals. 14 references, 1 table.

  15. High activity carbon sorbents for mercury capture

    Directory of Open Access Journals (Sweden)

    Stavropoulos George G.

    2006-01-01

    Full Text Available High efficiency activated carbons have been prepared for removing mercury from gas streams. Starting materials used were petroleum coke, lignite, charcoal and olive seed waste, and were chemically activated with KOH. Produced adsorbents were primarily characterized for their porosity by N2 adsorption at 77 K. Their mercury retention capacity was characterized based on the breakthrough curves. Compared with typical commercial carbons, they have exhibited considerably enhanced mercury adsorption capacity. An attempt has been made to correlate mercury entrapment and pore structure. It has been shown that physical surface area is increased during activation in contrast to the mercury adsorption capacity that initially increases and tends to decrease at latter stages. Desorption of active sites may be responsible for this behavior.

  16. Release of volatile mercury from vascular plants

    Science.gov (United States)

    Siegel, S. M.; Puerner, N. J.; Speitel, T. W.

    1974-01-01

    Volatile, organic solvent soluble mercury has been found in leaves and seeds of several angiosperms. Leaves of garlic vine, avocado, and haole-koa release mercury in volatile form rapidly at room temperature. In garlic vine, the most active release is temperature dependent, but does not parallel the vapor-pressure temperature relationship for mercury. Mercury can be trapped in nitric-perchloric acid digestion fluid, or n-hexane, but is lost from the hexane unless the acid mixture is present. Seeds of haole-koa also contain extractable mercury but volatility declines in the series n-hexane (90%), methanol (50%), water (10%). This suggests that reduced volatility may accompany solvolysis in the more polar media.

  17. Mercury removal from solid mixed waste

    International Nuclear Information System (INIS)

    Gates, D.D.; Morrissey, M.; Chava, K.K.; Chao, K.

    1994-01-01

    The removal of mercury from mixed wastes is an essential step in eliminating the temporary storage of large inventories of mixed waste throughout the Department of Energy (DOE) complex. Currently thermal treatment has been identified as a baseline technology and is being developed as part of the DOE Mixed Waste Integrated Program (MWIP). Since thermal treatment will not be applicable to all mercury containing mixed waste and the removal of mercury prior to thermal treatment may be desirable, laboratory studies have been initiated at Oak Ridge National Laboratory (ORNL) to develop alternative remediation technologies capable of removing mercury from certain mixed waste. This paper describes laboratory investigations of the KI/I 2 leaching processes to determine the applicability of this process to mercury containing solid mixed waste

  18. Removal of mercury by adsorption: a review.

    Science.gov (United States)

    Yu, Jin-Gang; Yue, Bao-Yu; Wu, Xiong-Wei; Liu, Qi; Jiao, Fei-Peng; Jiang, Xin-Yu; Chen, Xiao-Qing

    2016-03-01

    Due to natural and production activities, mercury contamination has become one of the major environmental problems over the world. Mercury contamination is a serious threat to human health. Among the existing technologies available for mercury pollution control, the adsorption process can get excellent separation effects and has been further studied. This review is attempted to cover a wide range of adsorbents that were developed for the removal of mercury from the year 2011. Various adsorbents, including the latest adsorbents, are presented along with highlighting and discussing the key advancements on their preparation, modification technologies, and strategies. By comparing their adsorption capacities, it is evident from the literature survey that some adsorbents have shown excellent potential for the removal of mercury. However, there is still a need to develop novel, efficient adsorbents with low cost, high stability, and easy production and manufacture for practical utility.

  19. A large industrial pollution problem on the Kyrgyzstan - Uzbekistan border: Soviet production of mercury and stibium for the Soviet military

    International Nuclear Information System (INIS)

    Hadjamberdiev, I.; Tukhvatshin, R.

    2009-01-01

    Soviet industry of mercury and stibium was located in South-East Fergana in Kyrgyzstan and Uzbekistan boarder. Khaidarken combine produced high pure mercury (99.9997 percent) since 1940, it was the second source in the World (after Almadena, Spain). Maximal production was 790 t in 1990, after Transitional Shock about 300 tons a year. Tail was established in 1967. There is special tube 5500 m transporting pulp to tail. The pulp contains about 0,003 mg/liter mercury, 0,005 mg/liter arsenic, 21 mg/liter stibium, etc. Pulp is cleaned by aluminum sulfuric and mortar. After drying and compressing by itself the concentrations rises: mercury 90-250 mg/kg, arsenic 190-400, stibium 800-1700 mg/kg. Environment pollution problem contains three kinds: ground water infiltration; old tube corroding some places (leaking from chink of tube) - both mentioned lead to vegetables cumulating; combine work spreading mercury by air to settlement Khaidarken. Kadamjay enterprise for stibium (mines, combine, purify plant, tails) began work in 1936. Most part of production used in soviet military. Maximal production was 17.000 t clearing ore in 1990, after USSR collapse 1-6 t/year. Tremendous tails and dams (total 150 mln t) remains non re-cultivated until now. The tails contain electrolysis wastage: sodium-sulfides, sulfites, sulfates; stibium; arsenic; cadmium; stibium; etc. Seven deposits (tail-damp really) established 1976, total square 76.1 thousands sq m, total volume 250 thousand cub m. The deposits over-filled, contents filtrating - little saline or lakes generated (one situated 50m near Uzbekistan boarder). River Shakhimardan flow to Uzbekistan (settlement Vuadil, Ferghana town). There are health damage indices in the areas.(author)

  20. Simultaneous removal of sulfide, nitrate and acetate under denitrifying sulfide removal condition: Modeling and experimental validation

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Xijun; Chen, Chuan; Wang, Aijie; Guo, Wanqian; Zhou, Xu [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Lee, Duu-Jong, E-mail: djlee@ntu.edu.tw [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan (China); Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); Ren, Nanqi, E-mail: rnq@hit.edu.cn [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Chang, Jo-Shu [Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan, Taiwan (China)

    2014-01-15

    Graphical abstract: Model evaluation applied to case study 1: (A-G) S{sup 2−}, NO{sub 3}{sup −}-N, NO{sub 2}{sup −}-N, and Ac{sup −}-C profiles under initial sulfide concentrations of 156.2 (A), 539 (B), 964 (C), 1490 (D), 342.7 (E), 718 (F), and 1140.7 (G) mg L{sup −1}. The solid line represents simulated result and scatter represents experimental result. -- Highlights: • This work developed a mathematical model for DSR process. • Kinetics of sulfur–nitrogen–carbon and interactions between denitrifiers were studied. • Kinetic parameters of the model were estimated via data fitting. • The model described kinetic behaviors of DSR processes over wide parametric range. -- Abstract: Simultaneous removal of sulfide (S{sup 2−}), nitrate (NO{sub 3}{sup −}) and acetate (Ac{sup −}) under denitrifying sulfide removal process (DSR) is a novel biological wastewater treatment process. This work developed a mathematical model to describe the kinetic behavior of sulfur–nitrogen–carbon and interactions between autotrophic denitrifiers and heterotrophic denitrifiers. The kinetic parameters of the model were estimated via data fitting considering the effects of initial S{sup 2−} concentration, S{sup 2−}/NO{sub 3}{sup −}-N ratio and Ac{sup −}-C/NO{sub 3}{sup −}-N ratio. Simulation supported that the heterotrophic denitratation step (NO{sub 3}{sup −} reduction to NO{sub 2}{sup −}) was inhibited by S{sup 2−} compared with the denitritation step (NO{sub 2}{sup −} reduction to N{sub 2}). Also, the S{sup 2−} oxidation by autotrophic denitrifiers was shown two times lower in rate with NO{sub 2}{sup −} as electron acceptor than that with NO{sub 3}{sup −} as electron acceptor. NO{sub 3}{sup −} reduction by autotrophic denitrifiers occurs 3–10 times slower when S{sup 0} participates as final electron donor compared to the S{sup 2−}-driven pathway. Model simulation on continuous-flow DSR reactor suggested that the adjustment of

  1. Influences of iron, manganese, and dissolved organic carbon on the hypolimnetic cycling of amended mercury

    International Nuclear Information System (INIS)

    Chadwick, Shawn P.; Babiarz, Chris L.; Hurley, James P.; Armstrong, David E.

    2006-01-01

    The biogeochemical cycling of iron, manganese, sulfide, and dissolved organic carbon were investigated to provide information on the transport and removal processes that control the bioavailability of isotopic mercury amended to a lake. Lake profiles showed a similar trend of hypolimnetic enrichment of Fe, Mn, DOC, sulfide, and the lake spike ( 202 Hg, purity 90.8%) and ambient of pools of total mercury (HgT) and methylmercury (MeHg). Hypolimnetic enrichment of Fe and Mn indicated that reductive mobilization occurred primarily at the sediment-water interface and that Fe and Mn oxides were abundant within the sediments prior to the onset of anoxia. A strong relationship (r 2 = 0.986, n = 15, p 2 = 0.966, n = 15, p 2 = 0.964, n = 15, p 2 = 0.920, n = 27, p 2 = 0.967, n = 23, p 2 = 0.406, n = 27, p 2 = 0.314, n = 15, p = 0.002) suggest a role of organic matter in Hg transport and cycling. However, a weak relationship between the ambient and lake spike pools of MeHg to DOC indicated that other processes have a major role in controlling the abundance and distribution of MeHg. Our results suggest that Fe and Mn play important roles in the transport and cycling of ambient and spike HgT and MeHg in the hypolimnion, in part through processes linked to the formation and dissolution of organic matter-containing Fe and Mn hydrous oxides particles

  2. Tracing Dietary Mercury Histochemically, with Autometallography, through the Liver to the Ovaries and Spawned Eggs of the Spot, a Temperate Coastal Marine Fish.

    Science.gov (United States)

    Govoni, John J; Morris, James A; Evans, David W

    2017-09-01

    Exposure to mercury (Hg) results in reproductive abnormalities and deficiencies in female fish. We traced the maternal assimilation and redistribution of dietary inorganic (HgII) and organic (MeHg) forms of Hg in a coastal marine fish, the Spot Leiostomus xanthurus. We conducted a 90-d laboratory experiment in which treatment Spot were fed muscle of Blue Marlin Makaira nigricans with elevated concentrations of Hg mixed with a commercial fish food, while control Spot were fed only commercial food pellets. Gonadal maturation was induced by shortening the photoperiod and increasing the temperature. Spawning was induced by intramuscular injection of human chorionic gonadotropin at 100 IU/kg. Solid-sampling atomic absorption spectrophotometry measured the total Hg (THg), HgII, and MeHg in Blue Marlin muscle. Autometallography located Hg-sulfide granules in the liver, ovaries, and spawned eggs, and densitometry provided comparisons of Hg-sulfide granules in the ovaries of treatment and control Spot. Overall, the intensity and prevalence of Hg-sulfide granules were greater in the liver, ovaries, and eggs from treatment Spot than in those from controls. The tissue and cellular distribution of Hg-sulfide granules differed. Received November 18, 2016; accepted June 18, 2017.

  3. 21 CFR 880.2920 - Clinical mercury thermometer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Clinical mercury thermometer. 880.2920 Section 880... Devices § 880.2920 Clinical mercury thermometer. (a) Identification. A clinical mercury thermometer is a... mercury. (b) Classification. Class II (special controls). The device is exempt from the premarket...

  4. Mercury content of shark from south-western Australian waters

    Energy Technology Data Exchange (ETDEWEB)

    Caputi, N.; Edmonds, J.S.; Heald, D.I.

    1979-11-01

    Muscle samples from four species of commercially sought sharks off the Western Australia coast were analyzed for total mercury. While substantial amounts of mercury were accumulated by sharks, as by other marine fish, the lack of polluting industry on the coast indicates that such mercury levels probably are natural. Mercury concentrations generally increased with fish size. (4 graphs, 1 map, 8 references, 2 tables)

  5. 21 CFR 862.3600 - Mercury test system.

    Science.gov (United States)

    2010-04-01

    ....3600 Mercury test system. (a) Identification. A mercury test system is a device intended to measure mercury, a heavy metal, in human specimens. Measurements obtained by this device are used in the diagnosis... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Mercury test system. 862.3600 Section 862.3600...

  6. Distribution and excretion of inhaled mercury vapour

    Energy Technology Data Exchange (ETDEWEB)

    Gage, J C

    1961-01-01

    Rats have been exposed for varying periods to an atmosphere containing 1 mg/cu.m. mercury vapor. The toxic effects produced showed resemblances to signs of mercurialism in man. An attempt has been made to study the kinetics of absorption and excretion of mercury from measurements of the amounts excreted and stored in the tissues. The efficiency of absorption of mercury by the rat lung is about 50%. A small proportion is excreted into the gut. After about 10 days of continuous exposure a steady state is reached in which excretion balances absorption. During short exposures the turnover of mercury in all tissues except brain is fairly rapid and most of the mercury is cleared from the body within a week after exposure. The urinary excretion of mercury, during the initial stage of storage in the tissues and the final stage of clearance, shows divergencies from the simple exponential pattern; there appears to be a delay mechanism in the kidney which, in intermittent exposures, may result in the occurrence of peak excretion during periods of non-exposure. After more prolonged exposures the mercury in the kidney appears to be converted to a form which is only very slowly excreted. The significance of the urinary excretion of mercury by man after industrial exposure to mercury vapour is discussed. The rat experiments suggest that single measurements will give only limited information concerning industrial conditions, but that an approximate assessment of the total absorbed during a working week would be obtained if it were possible to make a seven-day collection of urine. Repeated measurements after exposure would yield information on the duration of exposure and would have some diagnostic value.

  7. Mercury flow experiments. 4th report: Measurements of erosion rate caused by mercury flow

    International Nuclear Information System (INIS)

    Kinoshita, Hidetaka; Kaminaga, Masanori; Haga, Katsuhiro; Hino, Ryutaro

    2002-06-01

    The Japan Atomic Energy Research Institute (JAERI) and the High Energy Accelerator Research Organization (KEK) are promoting a construction plan of the Material-Life Science Facility, which is consisted of a Muon Science Facility and a Neutron Scattering Facility, in order to open up the new science fields. The Neutron Scattering Facility will be utilized for advanced fields of Material and Life science using high intensity neutron generated by the spallation reaction of a 1 MW pulsed proton beam and mercury target. Design of the spallation mercury target system aims to obtain high neutron performance with high reliability and safety. Since the target system is using mercury as the target material and contains large amount of radioactive spallation products, it is necessary to estimate reliability for strength of instruments in a mercury flow system during lifetime of the facility. Piping and components in the mercury flow system would be damaged by erosion with mercury flow, since these components will be weak by thickness decreasing. This report presents experimental results of wall thickness change by erosion using a mercury experimental loop. In the experiments, an erosion test section and coupons were installed in the mercury experimental loop, and their wall thickness was measured with an ultra sonic thickness gage after every 1000 hours. As a result, under 0.7 m/s of mercury velocity condition which is slightly higher than the practical velocity in mercury pipelines, the erosion is about 3 μm in 1000 hours. The wall thickness decrease during facility lifetime of 30 years is estimated to be less than 0.5 mm. According to the experimental result, it is confirmed that the effect of erosion on component strength is extremely small. Moreover, a measurement of residual mercury on the piping surface was carried out. As a result, 19 g/m 2 was obtained as the residual mercury for the piping surface. According to this result, estimated amount of residual mercury for

  8. Separation of platinum metals by theirs extraction as sulfides

    International Nuclear Information System (INIS)

    Pilipenko, A.T.; Ryabushko, O.P.; Ty Van Mak

    1978-01-01

    Separation of platinum metals by means of their sediment in the form of sulfides with subsequent extraction is studied. The optimum conditions of metal sulfide extraction are determined, the metal output dependence from acidness and aqueous phase composition and also the organic solvent nature are investigated. Ruthenium concentration was determined photometrically. Ruthenium sulfide is extracted by butyl spirit from 1-4 normal hydrochloric acid. The maximum extraction grade of 63% is reached in 3.2-normal acid. When the mixture of acetic and hydrochloric acids (2:1) is used for decomposition of ruthenium tiosalts, the grade of ruthenium extraction by amyl spirit or the mixture of anyl and butyl spirits (1:1) constitutes 100%

  9. Metal sulfide electrodes and energy storage devices thereof

    Science.gov (United States)

    Chiang, Yet-Ming; Woodford, William Henry; Li, Zheng; Carter, W. Craig

    2017-02-28

    The present invention generally relates to energy storage devices, and to metal sulfide energy storage devices in particular. Some aspects of the invention relate to energy storage devices comprising at least one flowable electrode, wherein the flowable electrode comprises an electroactive metal sulfide material suspended and/or dissolved in a carrier fluid. In some embodiments, the flowable electrode further comprises a plurality of electronically conductive particles suspended and/or dissolved in the carrier fluid, wherein the electronically conductive particles form a percolating conductive network. An energy storage device comprising a flowable electrode comprising a metal sulfide electroactive material and a percolating conductive network may advantageously exhibit, upon reversible cycling, higher energy densities and specific capacities than conventional energy storage devices.

  10. Preparation of transition metal sulfide nanoparticles via hydrothermal route

    International Nuclear Information System (INIS)

    Fei-Ling, P.; Chin-Hua, C.; Sarani Zakaria; Tze-Khong, L.; Mohd Ambar Yarmo; Nay-Ming, H.

    2010-01-01

    Nano sized copper sulfide, iron sulfide and molybdenum sulfide were successfully synthesised via a simple hydrothermal method. Sodium thiosulfate pentahydrate (Na 2 S 2 O 3 ·5H 2 O) and hydroxylamine sulfate ((H 3 NO) 2 ·H 2 SO 4 ) were used as the starting materials and reacted with the transition metal source at 200 degree Celsius for 90 min. The products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and Fourier transform infrared spectroscopy (FTIR). Spherical shape CuS and FeS 2 nanoparticles with high crystallinity were successfully produced. The transmission electron micrographs revealed the well-dispersibility of the produced nanoparticles. Scanning electron micrograph showed the MoS 2 nanoparticles possessed a spherical shape with sheet-like structure covering on the outer surface of the particles. (author)

  11. Conspicuous veils formed by vibrioid bacteria on sulfidic marine sediment

    DEFF Research Database (Denmark)

    Thar, Roland Matthias; Kühl, Michael

    2002-01-01

    , but the bacteria have so far not been isolated in pure culture, and a detailed characterization of their metabolism is still lacking. The bacteria are colorless, gram-negative, and vibrioid-shaped (1.3- to 2.5- by 4- to 10-µm) cells that multiply by binary division and contain several spherical inclusions of poly......We describe the morphology and behavior of a hitherto unknown bacterial species that forms conspicuous veils (typical dimensions, 30 by 30 mm) on sulfidic marine sediment. The new bacteria were enriched on complex sulfidic medium within a benthic gradient chamber in oxygen-sulfide countergradients......, forming a cohesive whitish veil at the oxic-anoxic interface. Bacteria attached to the veil kept rotating and adapted their stalk lengths dynamically to changing oxygen concentrations. The joint action of rotating bacteria on the veil induced a homogeneous water flow from the oxic water region toward...

  12. Study of radiation synovectomy using 188Re-sulfide

    International Nuclear Information System (INIS)

    Chen Gang; Li Peiyong; Jiang Xufeng; Zhang Liying; Wang Xuefeng; Sun Zhenming; Zhang Huan

    2002-01-01

    Objective: To study the radiation synovectomy with 188 Re-sulfide. Methods: Thirty cases were divided into 2 groups, the group with hemophilia and the group with rheumatoid arthritis (RA). Patients with joint synovitis were injected different doses of 188 Re-sulfide, 222 - 444 MBq intra-articular. MRI was taken before and 3 - 6 months after the radiation synovectomy to evaluate the treatment efficacy, and the symptoms were also evaluated. Results: MRI study showed that after the treatment the synovium became thiner and the edema was reduced in the lesioned joint. The symptoms were improved with the pain relieved and duration of intra-articular hemorrhage reduced. Conclusions: Radiation synovectomy using 188 Re-sulfide has effects on synovitis. It can be used clinically to improve the symptoms of joint synovitis and reduce the duration of intra-articular hemorrhage

  13. Estimating mercury emissions from a zinc smelter in relation to China's mercury control policies

    International Nuclear Information System (INIS)

    Wang, S.X.; Song, J.X.; Li, G.H.; Wu, Y.; Zhang, L.; Wan, Q.; Streets, D.G.; Chin, Conrad K.; Hao, J.M.

    2010-01-01

    Mercury concentrations of flue gas at inlet/outlet of the flue gas cleaning, electrostatic demister, reclaiming tower, acid plant, and mercury contents in zinc concentrate and by-products were measured in a hydrometallurgical zinc smelter. The removal efficiency of flue gas cleaning, electrostatic demister, mercury reclaiming and acid plant was about 17.4%, 30.3%, 87.9% and 97.4% respectively. Flue gas cleaning and electrostatic demister captured 11.7% and 25.3% of the mercury in the zinc concentrate, respectively. The mercury reclaiming tower captured 58.3% of the mercury in the zinc concentrate. About 4.2% of the mercury in the zinc concentrate was captured by the acid plant. Consequently, only 0.8% of the mercury in the zinc concentrate was emitted to the atmosphere. The atmospheric mercury emission factor was 0.5 g t -1 of zinc produced for the tested smelter, indicating that this process offers the potential to effectively reduce mercury emissions from zinc smelting. - Modern scale production equipped with acid plant and Hg reclaiming tower will significantly reduce Hg emissions from zinc smelters in China.

  14. Mercury migration into ground water, a literature study

    Energy Technology Data Exchange (ETDEWEB)

    Carlton, W.H.; Carden, J.L.; Kury, R.; Eichholz, G.G.

    1994-11-01

    This report presents a broad review of the technical literature dealing with mercury migration in the soil. The approach followed was to identify relevant articles by searching bibliographic data bases, obtaining the promising articles and searching these articles for any additional relevant citations. Eight catagories were used to organize the literature, with a review and summary of each paper. Catagories used were the following: chemical states of mercury under environmental conditions; diffusion of mercury vapor through soil; solubility and stability of mercury in environmental waters; transport of mercury on colloids; models for mercury migration through the environment; analytical techniques; retention of mercury by soil components; formation of organomecurials.

  15. Study of high levels indoor air mercury contamination from mercury amalgam use in dentistry

    International Nuclear Information System (INIS)

    Khwaja, M.A.; Abbasi, M.S.; Mehmood, F.; Jahangir, S.

    2014-01-01

    In 2005, United Nations Environment Programme (UNEP) estimated that 362 tonnes of dental mercury are consumed annually worldwide. Dental mercury amalgams also called silver fillings and amalgam fillings are widely done. These fillings gave off mercury vapours. Estimated average absorbed concentrations of mercury vapours from dental fillings vary from 3,000 to 17,000 ng Hg. Mercury (Hg) also known as quick silver is an essential constituent of dental amalgam. It is a toxic substance of global concern. A persistent pollutant, mercury is not limited to its source but it travels, on time thousands of kilometers away from the source. Scientific evidence, including, UNEP Global Mercury report, establishes mercury as an extremely toxic substance, which is a major threat to wildlife, ecosystem and human health, at a global scale. Children are more at risk from mercury poisoning which affects their neurological development and brain. Mercury poisoning diminishes memory, attention, thinking and sight. In the past, a number of studies at dental sites in many countries have been carried out and reported which have been reviewed and briefly described. This paper describes and discusses the recent investigations, regarding mercury vapours level in air, carried out at 18 dental sites in Pakistan and other countries. It is evident from the data of 42 dental sites in 17 countries, including, selected dental sites in five main cities of Pakistan, described and discussed in this paper that at most dental sites in many countries including Pakistan, the indoor mercury vapours levels exceed far above the permissible limit, recommended for safe physical and mental health. At these sites, public, in general, and the medical, paramedical staff and vulnerable population, in particular, are at most serious risk to health resulting from exposure to toxic and hazardous mercury. (author)

  16. ELECTROCHEMICAL DETERMINATION OF HYDROGEN SULFIDE AT CARBON NANOTUBE MODIFIED ELECTRODES. (R830900)

    Science.gov (United States)

    Carbon nanotube (CNT) modified glassy carbon electrodes exhibiting a strong and stable electrocatalytic response towards sulfide are described. A substantial (400 mV) decrease in the overvoltage of the sulfide oxidation reaction (compared to ordinary carbon electrodes) is...

  17. Mercuri tutuksi Y-sukupolvelle

    OpenAIRE

    Kyyhkynen, Toni; Kaisla, Noora

    2016-01-01

    Opinnäytetyö on tuotettu toimeksiantona Mercuri International Oy:lle. Opinnäytetyön tavoitteena oli tehdä Mercurille markkinointisuunnitelma, joka lisäisi yrityksen tunnettuutta Y-sukupolven silmissä kohderyhmälle sopivien markkinointitoimenpiteiden avulla. Toinen tavoite oli luoda keskustelua ja kiinnostusta Metropolian Liiketalouden opiskelijoiden keskuudessa B2B-myynnin alaa kohtaan. Teoreettinen osuus antaa viitekehyksen opinnäytetyön tutkimustehtävän sekä toimeksiannon kannalta oleel...

  18. Treatment of mercury containing waste

    Science.gov (United States)

    Kalb, Paul D.; Melamed, Dan; Patel, Bhavesh R; Fuhrmann, Mark

    2002-01-01

    A process is provided for the treatment of mercury containing waste in a single reaction vessel which includes a) stabilizing the waste with sulfur polymer cement under an inert atmosphere to form a resulting mixture and b) encapsulating the resulting mixture by heating the mixture to form a molten product and casting the molten product as a monolithic final waste form. Additional sulfur polymer cement can be added in the encapsulation step if needed, and a stabilizing additive can be added in the process to improve the leaching properties of the waste form.

  19. Final amplifier design and mercury

    International Nuclear Information System (INIS)

    Rose, E.A.; Hanson, D.E.

    1991-01-01

    The final amplifier for the Mercury KrF excimer facility is being designed. The design exercise involves extensive modeling to predict amplifier performance. Models of the pulsed-power system, including a Child-Langmuir diode with closure, electron-beam energy deposition, KrF laser kinetics, amplified spontaneous emission (ASE), a time-dependent laser extraction in the presence of ASE are presented as a design package. The design exercise indicates that the energy objective of Phase I -- 100 joules -- will be met

  20. Geodesy at Mercury with MESSENGER

    Science.gov (United States)

    Smith, David E.; Zuber, Maria t.; Peale, Stanley J.; Phillips, Roger J.; Solomon, Sean C.

    2006-01-01

    In 2011 the MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) spacecraft will enter Mercury orbit and begin the mapping phase of the mission. As part of its science objectives the MESSENGER mission will determine the shape and gravity field of Mercury. These observations will enable the topography and the crustal thickness to be derived for the planet and will determine the small libration of the planet about its axis, the latter critical to constraining the state of the core. These measurements require very precise positioning of the MESSENGER spacecraft in its eccentric orbit, which has a periapsis altitude as low as 200 km, an apoapsis altitude near 15,000 km, and a closest approach to the surface varying from latitude 60 to about 70 N. The X-band tracking of MESSENGER and the laser altimetry are the primary data that will be used to measure the planetary shape and gravity field. The laser altimeter, which has an expected range of 1000 to 1200 km, is expected to provide significant data only over the northern hemisphere because of MESSENGER's eccentric orbit. For the southern hemisphere, radio occultation measurements obtained as the spacecraft passes behind the planet as seen from Earth and images obtained with the imaging system will be used to provide the long-wavelength shape of the planet. Gravity, derived from the tracking data, will also have greater resolution in the northern hemisphere, but full global models for both topography and gravity will be obtained at low harmonic order and degree. The limiting factor for both gravity and topography is expected to be knowledge of the spacecraft location. Present estimations are that in a combined tracking, altimetry, and occultation solution the spacecraft position uncertainty is likely to be of order 10 m. This accuracy should be adequate for establishing an initial geodetic coordinate system for Mercury that will enable positioning of imaged features on the surface, determination of

  1. Analysis of mercury diffusion pumps

    International Nuclear Information System (INIS)

    Dunn, K.A.

    1991-01-01

    Several mercury diffusion pump stages in the Tritium Purification process at the Savannah River Site (SRS) have been removed from service for scheduled preventive maintenance. These stages have been examined to determine if failure has occurred. Evidence of fatigue around the flange portion of the pump has been seen. In addition, erosion and cavitation inside the throat of the venturi tube and corrosion on the other surface of the venturi tube has been observed. Several measures are being examined in an attempt to improve the performance of these pumps. These measures, as well as the noted observations, are described. 4 refs

  2. Legislation, standards and methods for mercury emissions control

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-04-15

    Mercury is an element of growing global concern. The United Nations Environment Programme plans to finalise and ratify a new global legally-binding convention on mercury by 2013. Canada already has legislation on mercury emissions from coal-fired utilities and the USA has recently released the new Mercury and Air Toxics Standard. Although other countries may not have mercury-specific legislation as such, many have legislation which results in significant co-benefit mercury reduction due to the installation of effective flue-gas cleaning technologies. This report reviews the current situation and trends in mercury emission legislation and, where possible, discusses the actions that will be taken under proposed or impending standards globally and regionally. The report also reviews the methods currently applied for mercury control and for mercury emission measurement with emphasis on the methodologies most appropriate for compliance. Examples of the methods of mercury control currently deployed in the USA, Canada and elsewhere are included.

  3. Biogeochemistry of mercury in contaminated environment in the wider Idrija region and the Gulf of Trieste. Highlights and achievements

    International Nuclear Information System (INIS)

    Horvat, Milena

    2002-01-01

    Activities at mercury (Hg) mines can lead to the mobilization of large quantities of Hg that enter the environment and are transported downstream. Although much of this Hg is deposited near the source, over time much of this Hg can be carried hundreds of kilometers where it can potentially enter and bioaccumulate in distant food webs. Mining activities in the ldrija, Slovenia mining district occurred for 500 years and the legacy of that mining can be seen in high concentrations of Hg throughout the watershed and into the Gulf of Trieste. Mercury concentrations are high in the sediments near the mouth of the Soca/Isonzo, River in the Gulf, and the Soca River continues to deliver ∼1.5 tons of Hg to the marine environment ∼100 km from the mine. Much of the Hg carried to the sea is probably as fine cinnabar particles, and the potential remobilization and further transformation of this Hg is of concern with regard to local environmental and the accumulation of methylmercury (MeHg in seafood. Mercury sulfide minerals are subject to dissolution and increased bioavailability when they contact sulfidic environments such as what occurs in coastal marine sediments. This 'newly' available Hg can potentially undergo methylation to supply the environment with newly formed MeHg. Indeed, Gulf sediments contain significant concentrations of MeHg and effluxes of MeHg from Gulf sediments have been observed in recent studies. However, sediments can also support active demethylation by aerobic and anaerobic bacteria. This demethylation can be due to either oxidative or reductive pathways. The present study was conducted to determine the potential of sediments from the Gulf of Trieste to methylate and demethylate Hg including an assessment of which demethylation pathway is most prevalent

  4. Vegetation successfully prevents oxidization of sulfide minerals in mine tailings.

    Science.gov (United States)

    Li, Yang; Sun, Qingye; Zhan, Jing; Yang, Yang; Wang, Dan

    2016-07-15

    The oxidization of metal sulfide in tailings causes acid mine drainage. However, it remains unclear whether vegetation prevents the oxidization of metal sulfides. The oxidization characteristics and microbial indices of the tailings in the presence of various plant species were investigated to explore the effects of vegetation on the oxidization of sulfide minerals in tailings. The pH, reducing sulfur, free iron oxides (Fed), chemical oxygen consumption (COC) and biological oxygen consumption (BOC) were measured. Key iron- and sulfur-oxidizing bacteria (Acidithiobacillus spp., Leptospirillum spp. and Thiobacillus spp.) were quantified using real-time PCR. The results indicate that vegetation growing on tailings can effectively prevent the oxidization of sulfide minerals in tailings. A higher pH and reducing-sulfur content and lower Fed were observed in the 0-30 cm depth interval in the presence of vegetation compared to bare tailings (BT). The COC gradually decreased with depth in all of the soil profiles; specifically, the COC rapidly decreased in the 10-20 cm interval in the presence of vegetation but gradually decreased in the BT profiles. Imperata cylindrica (IC) and Chrysopogon zizanoides (CZ) profiles contained the highest BOC in the 10-20 cm interval. The abundance of key iron- and sulfur-oxidizing bacteria in the vegetated tailings were significantly lower than in the BT; in particular, IC was associated with the lowest iron- and sulfur-oxidizing bacterial abundance. In conclusion, vegetation successfully prevented the oxidization of sulfide minerals in the tailings, and Imperata cylindrica is the most effective in reducing the number of iron- and sulfur-oxidizing bacteria and helped to prevent the oxidization of sulfide minerals in the long term. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. 40 CFR Appendix Xiii to Part 266 - Mercury Bearing Wastes That May Be Processed in Exempt Mercury Recovery Units

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Mercury Bearing Wastes That May Be Processed in Exempt Mercury Recovery Units XIII Appendix XIII to Part 266 Protection of Environment... XIII to Part 266—Mercury Bearing Wastes That May Be Processed in Exempt Mercury Recovery Units These...

  6. Groundwater Modeling of Mercury Pollution at a Former Mercury Cell Chlor Alkali Facility in Pavlodar City, Kazakhstan

    Science.gov (United States)

    In northern Kazakhstan, there is a serious case of mercury pollution near the city of Pavlodar from an old mercury cell chlor-alkali plant. The soil, sediment, and water is severely contaminated with mercury and mercury compounds as a result of the industrial activity of this ch...

  7. Mercury in the environment : a primer

    Energy Technology Data Exchange (ETDEWEB)

    Lourie, B; Glenn, W [ed.; Ogilvie, K; Everhardus, E; Friesen, K; Rae, S

    2003-06-01

    This report provides an overview of the occurrence and effects of mercury in the environment and its impacts on human health. Low levels of mercury occur naturally everywhere in the environment in plants, animals, rocks and air. Incidental emissions occur when natural mercury is released to the environment through human activity. In Canada, coal burning and metal processing are the two largest point sources of atmospheric mercury emissions. Energy facilities have the option to invest in expensive control technologies for coal plants, or they can generate electricity from alternative energy sources. Energy conservation, however, offers the greatest overall benefits for the environment and the public. Mercury can also be released when products containing mercury (such as electrical switches, thermostats, dental amalgam, and thermometers) are broken while in use, or when they are crushed in garbage trucks and dumped in landfills. Source separation is the best way to reduce waste-related emissions. Once mercury is released to the natural environment, it can be transported long distances through air or watercourses. It is volatile, therefore evaporates readily to the atmosphere where it may do one of three things: it may fall out near the point where it was emitted; it may be transported long distances to some point downwind; or, it may enter the global atmospheric mercury pool where it will circle the globe for a year or more within the Earth's major weather systems before being deposited. Data from Canada's National Pollutant Release Inventory indicates that mercury releases and transfers total 28,674 kg per year. The most critical component of the mercury cycle is the conversion of inorganic forms of mercury to the organic compound methylmercury which is more toxic to humans. Most concern about mercury focuses on lakes and other aquatic ecosystems. Fish in hydroelectric reservoirs have been found to contain elevated methylmercury levels because natural mercury in the

  8. Substance Flow Analysis of Mercury in China

    Science.gov (United States)

    Hui, L. M.; Wang, S.; Zhang, L.; Wang, F. Y.; Wu, Q. R.

    2015-12-01

    In previous studies, the emission of anthropogenic atmospheric Hg in China as well as single sector have been examined a lot. However, there might have been more Hg released as solid wastes rather than air. Hg stored in solid wastes may be released to air again when the solid wastes experience high temperature process or cause local pollution if the solid wastes are stacked casually for a long time. To trace the fate of Hg in China, this study developed the substance flow of Hg in 2010 covering all the sectors summarized in table 1. Below showed in Figure 1, the total Hg input is 2825t. The unintentional input of Hg, mined Hg, and recycled Hg account for 57%, 32% and 11% respectively. Figure 2 provides the detail information of substance flow of Hg. Byproducts from one sector may be used as raw materials of another, causing cross Hg flow between sectors. The Hg input of cement production is 303 t, of which 34% comes from coal and limestone, 33% comes from non-ferrous smelting, 23% comes from coal combustion, 7% comes from iron and steel production and 3% comes from mercury mining. Hg flowing to recycledHg production is 639 t, mainly from Hg contained in waste active carbon and mercuric chloride catalyst from VCM production and acid sludge from non-ferrous smelting. There are 20 t mercury flowing from spent mercury adding products to incineration. Figure1 and Figure 2 also show that 46% of the output Hg belongs to "Lagged release", which means this part of mercury might be released later. The "Lagged release" Hg includes 809 t Hg contained in stacked byproducts form coal combustion, non-ferrous smelting, iron and steel production, Al production, cement production and mercury mining, 161t Hg stored in the pipeline of VCM producing, 10 t Hg in fluorescent lamps that are in use and 314 t mercury stored in materials waiting to be handled with in recycled mercury plants. There is 112 t Hg stored in landfill and 129 t Hg exported abroad with the export of mercury adding

  9. Experimental constraints on gold and silver solubility in iron sulfides

    Energy Technology Data Exchange (ETDEWEB)

    Pal' yanova, Galina [Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, 3, Koptyuga, Novosibirsk, 630090 (Russian Federation); Novosibirsk State University, Russia, 2, Pirogova, Novosibirsk, 630090 (Russian Federation); Mikhlin, Yuri [Institute of Chemistry and Chemical Technology, Siberian Branch of the Russian Academy of Sciences, Akademgorodok, 50/24, Krasnoyarsk, 660036 (Russian Federation); Kokh, Konstantin, E-mail: k.a.kokh@gmail.com [Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, 3, Koptyuga, Novosibirsk, 630090 (Russian Federation); Novosibirsk State University, Russia, 2, Pirogova, Novosibirsk, 630090 (Russian Federation); Siberian Physical–Technical Institute of Tomsk State University, 1, Novosobornaya, Tomsk, 634050 (Russian Federation); Karmanov, Nick [Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, 3, Koptyuga, Novosibirsk, 630090 (Russian Federation); Seryotkin, Yurii [Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, 3, Koptyuga, Novosibirsk, 630090 (Russian Federation); Novosibirsk State University, Russia, 2, Pirogova, Novosibirsk, 630090 (Russian Federation)

    2015-11-15

    Experiments were performed to determine crystallization of Fe,S-melts (pyriti≿ and troilitic with molar ratio S/Fe ratios of 2 and 1, respectively) containing traces of gold and silver at (Ag/Au){sub wt} ratios varying from 10 to 0.1. The solid products were studied by optical microscopy, scanning electron microscopy, X-ray powder diffraction (XRD), microprobe analysis, and X-ray photoelectron spectroscopy (XPS) in order to reveal the concentration limits of “invisible” gold and silver in magmatic iron sulfides, and to determine the influence of sulfur on forms of precious metals in the Fe–S system with different Ag/Au ratios. Au–Ag phases do not form inclusions but instead concentrate on the grain boundaries in the synthetic pyrrhotite and troilite, while pyrite comprises micro- (1–5 μm) and macroinclusions of Au–Ag alloys and Au–Ag sulfides. In “pyriti≿” systems, the fineness of alloys increases from 650 to 970‰ and the composition of sulfides changes from acanthite (Ag{sub 2}S) to uytenbogaardtite (Ag{sub 3}AuS{sub 2}) and petrovskaite (AgAuS) as the Ag/Au ratio decreases. The concentrations of “invisible” precious metals revealed in troilite were 0.040 ± 0.013 wt.% Au and 0.079 ± 0.016 wt.% Ag. Measured concentrations in pyrite and pyrrhotite were <0.024 wt.% Au and <0.030 wt.% Ag. The surface layers of iron sulfides probed with XPS were enriched in the precious metals, and in silver relative to gold, especially in the systems with Fe/S = 1, probably, due to depletion of the metallic alloy surfaces with gold. Au- and Ag-bearing iron sulfides crystallized primarily from melts may be the source of redeposited phases in hydrothermal and hypergene processes. - Highlights: • The samples of Fe–S–Au–Ag system were synthesized. • Coupled solubility of gold and silver in iron sulfides was specified. • Ag–Au inclusions on surfaces of iron sulfides are likely to be enriched in silver. • Au–Ag sulfides can exist along with

  10. A sulfidation-resistant nickel-base alloy

    International Nuclear Information System (INIS)

    Lai, G.Y.

    1989-01-01

    For applications in mildly to moderately sulfidizing environments, stainless steels, Fe-Ni-Cr alloys (e.g., alloys 800 and 330), and more recently Fe-Ni-Cr-Co alloys (e.g., alloy 556) are frequently used for construction of process equipment. However, for many highly sulfidizing environments, few existing commercial alloys have adequate performance. Thus, a new nickel-based alloy containing 27 wt.% Co, 28 wt.% Cr, 4 wt.% Fe, 2.75 wt.% Si, 0.5 wt.% Mn and 0.05 wt.% C (Haynes alloy HR-160) was developed

  11. The solubility of iron sulfides and their role in mass transport in Girdler-Sulfide heavy water plants

    International Nuclear Information System (INIS)

    Tewari, P.H.; Wallace, G.; Campbell, A.B.

    1978-04-01

    The solubilities of several iron sulfides, mackinawite FeSsub((1-x)), troilite FeS, pyrrhotite Fesub((1-x))S (monoclinic and hexagonal), and pyrite FeS 2 have been determined in aqueous H 2 S solution at 0.1 MPa and 1.8 MPa H 2 S pressures between 25 deg and 125 deg C. The dependence of solubility on the pH of the medium has also been studied. It is concluded that since mackinawite is the most soluble of the iron sulfides, and has the highest dissolution rate and the steepest decline in solubility with temperature, its prolonged formation during plant operation should be avoided to minimize iron transport from lower to higher temperature areas in Girdler-Sulfide (G.S.) heavy water plants. This can be achieved by a preconditioning of carbon steel surfaces to convert mackinawite to pyrrhotite and pyrite

  12. Is succession in wet calcareous dune slacks affected by free sulfide?

    NARCIS (Netherlands)

    Adema, EB; van Gemerden, H; Grootjans, AP; Adema, Erwin B.; Grootjans, Ab P.; Rapson, G.

    Consequences of sulfide toxicity on succession in wet calcareous dune slacks were investigated. Sulfide may exert an inhibitory effect on dune slack plants, but several pioneer species exhibit ROL (Radial Oxygen Loss) and thereby protect themselves against free sulfide. Under oxic conditions free

  13. Identifying the Prospective Area of Sulfide Groundwater within the Area of Palvantash Oil and Gas Deposit

    Directory of Open Access Journals (Sweden)

    M. R. Zhurayev

    2014-03-01

    Full Text Available This paper describes the methodology of prospecting for sulfide groundwater in the area of Palvantash oil fields. In result of study allowed determining the favorable conditions for the sulfide waters formation, and mapping the areas of different sulfide water concentration. The relatively permeable areas were established and the water borehole positions were recommended.

  14. 76 FR 69136 - Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting

    Science.gov (United States)

    2011-11-08

    ... Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting AGENCY: Environmental Protection Agency (EPA). ACTION: Lifting of Administrative Stay for Hydrogen Sulfide; Correction. SUMMARY: The... Administrative Stay of the reporting requirements for hydrogen sulfide. The Office of the Federal Register...

  15. A real support effect on the hydrodeoxygenation of methyl oleate by sulfided NiMo catalysts

    NARCIS (Netherlands)

    Coumans, A.E.; Hensen, E.J.M.

    2017-01-01

    The effect of the support on the catalytic performance of sulfided NiMo in the hydrodeoxygenation of methyl oleate as a model compound for triglyceride upgrading to green diesel was investigated. NiMo sulfides were prepared by impregnation and sulfidation on activated carbon, silica, γ-alumina and

  16. Sulfide-iron interactions in domestic wastewater from a gravity sewer

    NARCIS (Netherlands)

    Nielsen, A.H.; Lens, P.N.L.; Vollertsen, J.; Hvitved-Jacobsen, Th.

    2005-01-01

    Interactions between iron and sulfide in domestic wastewater from a gravity sewer were investigated with particular emphasis on redox cycling of iron and iron sulfide formation. The concentration ranges of iron and total sulfide in the experiments were 0.4-5.4 mg Fe L-1 and 0-5.1 mg S L-1,

  17. Sulfidation of alumina-supported iron and iron-molybdenum oxide catalysts

    NARCIS (Netherlands)

    Ramselaar, W.L.T.M.; Crajé, M.W.J.; Hadders, R.H.; Gerkema, E.; Beer, de V.H.J.; Kraan, van der A.M.

    1990-01-01

    The transition of alumina-supported iron and iron-molybdenum catalysts from the oxidic precursor to the sulfided catalysts was systematically studied by means of in-situ Mössbauer spectroscopy at room temperature. This enabled the adjudgement of various sulfidic phases in the sulfided catalysts. The

  18. A thin, dense crust for Mercury

    Science.gov (United States)

    Sori, Michael M.

    2018-05-01

    Crustal thickness is a crucial geophysical parameter in understanding the geology and geochemistry of terrestrial planets. Recent development of mathematical techniques suggests that previous studies based on assumptions of isostasy overestimated crustal thickness on some of the solid bodies of the solar system, leading to a need to revisit those analyses. Here, I apply these techniques to Mercury. Using MESSENGER-derived elemental abundances, I calculate a map of grain density (average 2974 ± 89 kg/m3) which shows that Pratt isostasy is unlikely to be a major compensation mechanism of Mercury's topography. Assuming Airy isostasy, I find the best fit value for Mercury's mean crustal thickness is 26 ± 11 km, 25% lower than the most recently reported and previously thinnest number. Several geological implications follow from this relatively low value for crustal thickness, including showing that the largest impacts very likely excavated mantle material onto Mercury's surface. The new results also show that Mercury and the Moon have a similar proportion of their rocky silicates composing their crusts, and thus Mercury is not uniquely efficient at crustal production amongst terrestrial bodies. Higher resolution topography and gravity data, especially for the southern hemisphere, will be necessary to refine Mercury's crustal parameters further.

  19. Atmospheric mercury in Changbai Mountain area, northeastern China II. The distribution of reactive gaseous mercury and particulate mercury and mercury deposition fluxes.

    Science.gov (United States)

    Wan, Qi; Feng, Xinbin; Lu, Julia; Zheng, Wei; Song, Xinjie; Li, Ping; Han, Shijie; Xu, Hao

    2009-08-01

    Reactive gaseous mercury (RGM) and particulate mercury (Hgp) concentrations in ambient air from a remote site at Changbai Mountain area in northeastern China were intermittently monitored from August 2005 to July 2006 totaling 93 days representing fall, winter-spring and summer season, respectively. Rainwater and snow samples were collected during a whole year, and total mercury (THg) in rain samples were used to calculate wet depositional flux. A throughfall method and a model method were used to estimate dry depositional flux. Results showed mean concentrations of RGM and Hgp are 65 and 77 pg m(-3). Compared to background concentrations of atmospheric mercury species in Northern Hemisphere, RGM and Hgp are significantly elevated in Changbai area. Large values for standard deviation indicated fast reactivity and a low residence time for these mercury species. Seasonal variability is also important, with lower mercury levels in summer compared to other seasons, which is attributed to scavenging by rainfall and low local mercury emissions in summer. THg concentrations ranged from 11.5 to 15.9 ng L(-1) in rainwater samples and 14.9-18.6 ng L(-1) in throughfall samples. Wet depositional flux in Changbai area is calculated to be 8.4 microg m(-2) a(-1), and dry deposition flux is estimated to be 16.5 microg m(-2) a(-1) according to a throughfall method and 20.2 microg m(-2) a(-1) using a model method.

  20. Failure probability analysis on mercury target vessel

    International Nuclear Information System (INIS)

    Ishikura, Syuichi; Futakawa, Masatoshi; Kogawa, Hiroyuki; Sato, Hiroshi; Haga, Katsuhiro; Ikeda, Yujiro

    2005-03-01

    Failure probability analysis was carried out to estimate the lifetime of the mercury target which will be installed into the JSNS (Japan spallation neutron source) in J-PARC (Japan Proton Accelerator Research Complex). The lifetime was estimated as taking loading condition and materials degradation into account. Considered loads imposed on the target vessel were the static stresses due to thermal expansion and static pre-pressure on He-gas and mercury and the dynamic stresses due to the thermally shocked pressure waves generated repeatedly at 25 Hz. Materials used in target vessel will be degraded by the fatigue, neutron and proton irradiation, mercury immersion and pitting damages, etc. The imposed stresses were evaluated through static and dynamic structural analyses. The material-degradations were deduced based on published experimental data. As a result, it was quantitatively confirmed that the failure probability for the lifetime expected in the design is very much lower, 10 -11 in the safety hull, meaning that it will be hardly failed during the design lifetime. On the other hand, the beam window of mercury vessel suffered with high-pressure waves exhibits the failure probability of 12%. It was concluded, therefore, that the leaked mercury from the failed area at the beam window is adequately kept in the space between the safety hull and the mercury vessel by using mercury-leakage sensors. (author)

  1. Occupational Metallic Mercury Poisoning in Gilders

    Directory of Open Access Journals (Sweden)

    M Vahabzadeh

    2016-04-01

    Full Text Available Occupational exposure to elemental mercury vapor usually occurs through inhalation during its utilizations. This leads to a variety of adverse health effects. In some Islamic cities, this type of poisoning may occur during gilding of shrines using elemental mercury with gold. Herein, we report on three male patients aged 20–53 years, who were diagnosed with occupational metallic mercury poisoning due to gilding of a shrine. All patients presented with neuro-psychiatric disorders such as anxiety, loss of memory and concentration, and sleep disorders with high urinary mercury concentrations of 326–760 μg/L upon referring, 3–10 days after cessation of elemental mercury exposure. Following chelating therapy, the patients recovered clinically and their mercury concentrations declined to non-toxic level (<25 μg/L. Health, environmental and labor authorities, as well as the gilders should be aware of the toxicity risk of exposure to metalic mercury during gilding in closed environments and act accordingly.

  2. Does mercury vapor exposure increase urinary selenium excretion

    Energy Technology Data Exchange (ETDEWEB)

    Hongo, T; Suzuki, T; Himeno, S; Watanabe, C; Satoh, H; Shimada, Y

    1985-01-01

    It has been reported that an increase of urinary selenium excretion may occur as a result of mercury vapor exposure. However, experimental data regarding the interaction between mercury vapor and selenium have yielded ambiguous results about the retention and elimination of selenium due to mercury vapor exposure and the decrease of selenium excretion due to mercury in the form of mercuric mercury (Hg/sup 2 +/). In this study, the authors measured urinary mercury and selenium in workers with or without exposure to mercury vapor to determine whether or not urinary selenium excretion was increased as a result of mercury vapor exposure. Urine samples were collected from 141 workers, 71 men and 70 women, whose extent of exposure to mercury vapor varied according to their job sites. Workers were divided into five groups according to their urinary mercury levels. The mercury level in group I was less than 2.8 nmol/mmol creatinine which means that this group was mostly free from mercury exposure. The average age was almost identical among the groups. For both sexes, group V (with the highest urinary mercury level) had the lowest urinary selenium level, but one-way variance analysis (ANOVA) did not reveal any significant variations of urinary selenium with urinary mercury levels; however, a weak but significant negative correlation between mercury and selenium was found in men.

  3. Mercury's magnetosphere and magnetotial revisited

    International Nuclear Information System (INIS)

    Bergan, S.; Engle, I.M.

    1981-01-01

    Magnetic observations which are not complicated by currents of trapped plasma are a good test of geomagnetopause and geomagnetotail predictions. Recent attempts to model the Hermean magnetospheric field based on a planet-centered magnetic multipole field with a quadrupole moment in addition to the planetary dipole field or a dipole field linearly displaced from planet center and no quadrupole moment have produced reasonably good fits to the Mercury magnetic field measurements. In this work we find a better fit for a dipole displacement from the planet center by making use of an improved representation of the magnetic field in the magnetotail, where many of the Mercury measurements were made. The rms deviation of the data was reduced from 10. or 11. γ to 9.3 γ by employing this new tail field representation. Also, by making use of this new tail field representation, we find a best fit for a dipole displacement of -0.0285 R/sub M/ (earlier, 0.026 R/sub M/) toward the dawn in the magnetic equatorial plane and 0.17 R/sub M/ (earlier, 0.189 R/sub M/ (earlier 0.189 R/sub M/) northward along the magnetic dipole axis, where R/sub M/ is the planet radius. Thus with only minor adjustments in the displacement vector of the dipole from the planet center we achieve a measurable improvement in the fit of the data by using the improved magnetotail field representation

  4. Concentration of mercury in wheat samples stored with mercury tablets as preservative

    International Nuclear Information System (INIS)

    Lalit, B.Y.; Ramachandran, T.V.

    1977-01-01

    Tablets consisting of mercury in the form of a dull grey powder made by triturating mercury with chalk and sugar are used in Indian household for storing food-grains. The contamination of wheat samples by mercury, when stored with mercury tablets for period of upto four years has been assessed by using non-destructive neutron activation analysis. The details of the analytical procedure used have also been briefly described. The concentration of mercury in wheat increases with storage period. Loss of weight of mercury tablet is proportional to the storage period to a first approximation. In the present experiment, the average weight loss at the and end of first year was 0.009716 g corresponding to 6 ppm in wheat. (T.G.)

  5. Mercury flow experiments. 4th report Measurements of erosion rate caused by mercury flow

    CERN Document Server

    Kinoshita, H; Hino, R; Kaminaga, M

    2002-01-01

    The Japan Atomic Energy Research Institute (JAERI) and the High Energy Accelerator Research Organization (KEK) are promoting a construction plan of the Material-Life Science Facility, which is consisted of a Muon Science Facility and a Neutron Scattering Facility, in order to open up the new science fields. The Neutron Scattering Facility will be utilized for advanced fields of Material and Life science using high intensity neutron generated by the spallation reaction of a 1 MW pulsed proton beam and mercury target. Design of the spallation mercury target system aims to obtain high neutron performance with high reliability and safety. Since the target system is using mercury as the target material and contains large amount of radioactive spallation products, it is necessary to estimate reliability for strength of instruments in a mercury flow system during lifetime of the facility. Piping and components in the mercury flow system would be damaged by erosion with mercury flow, since these components will be we...

  6. Concentration of mercury in wheat samples stored with mercury tablets as preservative. [Neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Lalit, B Y; Ramachandran, T V [Bhabha Atomic Research Centre, Bombay (India). Air Monitoring Section

    1977-01-01

    Tablets consisting of mercury in the form of a dull grey powder made by triturating mercury with chalk and sugar are used in Indian household for storing food-grains. The contamination of wheat samples by mercury, when stored with mercury tablets for period of upto four years has been assessed by using non-destructive neutron activation analysis. The details of the analytical procedure used have also been briefly described. The concentration of mercury in wheat increases with storage period. Loss of weight of mercury tablet is proportional to the storage period to a first approximation. In the present experiment, the average weight loss at the and end of first year was 0.009716 g corresponding to 6 ppm in wheat.

  7. Hidden sources of mercury in clinical laboratories.

    Science.gov (United States)

    Alvarez-Chavez, C R; Federico-Perez, R A; Gomez-Alvarez, A; Velazquez-Contreras, L E; Perez-Rios, R

    2014-09-01

    The healthcare sector is an important contributor to mercury (Hg) pollution because of the potential presence of mercury in thermometers, blood pressure cuffs, amalgams, etc. There are also other potential sources of mercury in this sector which are used frequently and in high volumes where the presence of the metal is not obvious and which might be collectively contributing to pollution. For instance, some chemicals used for the clinical diagnosis of illness may contain mercury. The goal of this study was to investigate potential sources of mercury pollution, which originate from clinical laboratory discharges, using an exploratory approach. The focus was on the residue generated during automatic analysis of patients' bodily fluids at a medical center in Hermosillo, Sonora, Mexico. This study shows an overview of what might be happening in the region or the country related to non-obvious sources of mercury in the healthcare sector. The results showed measurable levels of mercury in the residues coming from urine sediment analysis. These amounts do not exceed the maximum allowed by Mexican environmental regulations; nevertheless, the frequency and cumulative volume of residues generated, combined with the potential for persistence and the bioaccumulation of mercury in the environment, warrant attention. The work carried out in this study is being taken as a model for future studies for pollution prevention in the healthcare sector with the goal of measuring mercury emissions to the environment from clinical laboratory wastewater, including identifying sources which--while not obvious--could be important given the frequency and volume of their use in the clinical diagnosis.

  8. Understanding the mercury reduction issue: the impact of mercury on the environment and human health.

    Science.gov (United States)

    Kao, Richard T; Dault, Scott; Pichay, Teresa

    2004-07-01

    Mercury has been used in both medicine and dentistry for centuries. Recent media attention regarding the increased levels of mercury in dietary fish, high levels of mercury in air emissions, and conjecture that certain diseases may be caused by mercury exposure has increased public awareness of the potential adverse health effects of high doses of mercury. Dentistry has been criticized for its continued use of mercury in dental amalgam for both public health and environmental reasons. To address these concerns, dental professionals should understand the impact of the various levels and types of mercury on the environment and human health. Mercury is unique in its ability to form amalgams with other metals. Dental amalgam--consisting of silver, copper, tin, and mercury--has been used as a safe, stable, and cost-effective restorative material for more than 150 years. As a result of this use, the dental profession has been confronted by the public on two separate health issues concerning the mercury content in amalgam. The first issue is whether the mercury amalgamated with the various metals to create dental restorations poses a health issue for patients. The second is whether the scraps associated with amalgam placement and the removal of amalgam restorations poses environmental hazards which may eventually have an impact on human health. Despite the lack of scientific evidence for such hazards, there is growing pressure for the dental profession to address these health issues. In this article, the toxicology of mercury will be reviewed and the impact of amalgam on health and the environment will be examined.

  9. Methyl mercury, but not inorganic mercury, associated with higher blood pressure during pregnancy.

    Science.gov (United States)

    Wells, Ellen M; Herbstman, Julie B; Lin, Yu Hong; Hibbeln, Joseph R; Halden, Rolf U; Witter, Frank R; Goldman, Lynn R

    2017-04-01

    Prior studies addressing associations between mercury and blood pressure have produced inconsistent findings; some of this may result from measuring total instead of speciated mercury. This cross-sectional study of 263 pregnant women assessed total mercury, speciated mercury, selenium, and n-3 polyunsaturated fatty acids in umbilical cord blood and blood pressure during labor and delivery. Models with a) total mercury or b) methyl and inorganic mercury were evaluated. Regression models adjusted for maternal age, race/ethnicity, prepregnancy body mass index, neighborhood income, parity, smoking, n-3 fatty acids and selenium. Geometric mean total, methyl, and inorganic mercury concentrations were 1.40µg/L (95% confidence interval: 1.29, 1.52); 0.95µg/L (0.84, 1.07); and 0.13µg/L (0.10, 0.17), respectively. Elevated systolic BP, diastolic BP, and pulse pressure were found, respectively, in 11.4%, 6.8%, and 19.8% of mothers. In adjusted multivariable models, a one-tertile increase of methyl mercury was associated with 2.83mmHg (0.17, 5.50) higher systolic blood pressure and 2.99mmHg (0.91, 5.08) higher pulse pressure. In the same models, an increase of one tertile of inorganic mercury was associated with -1.18mmHg (-3.72, 1.35) lower systolic blood pressure and -2.51mmHg (-4.49, -0.53) lower pulse pressure. No associations were observed with diastolic pressure. There was a non-significant trend of higher total mercury with higher systolic blood pressure. We observed a significant association of higher methyl mercury with higher systolic and pulse pressure, yet higher inorganic mercury was significantly associated with lower pulse pressure. These results should be confirmed with larger, longitudinal studies. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Isolation, screening and identification of mercury resistant bacteria from mercury contaminated soil

    OpenAIRE

    Kowalczyk Anna; Wilińska Magdalena; Chyc Marek; Bojko Monika; Latowski Dariusz

    2016-01-01

    New bacterial strains resistant to high concentration of mercury were obtained and character iz ed focusing on their potential application in bioremediation. The biological material was isolated from soil contaminated with mercury. The ability to removal of Hg from the liquid medium and the effect of the various pH and mercury concentrations in the environment on bacterial strains growth kinetics were tested. The selected strains were identified by analysis of the 16S ribosome subunit coding ...

  11. Photochemical reactions between mercury (Hg) and dissolved organic matter decrease Hg bioavailability and methylation.

    Science.gov (United States)

    Luo, Hong-Wei; Yin, Xiangping; Jubb, Aaron M; Chen, Hongmei; Lu, Xia; Zhang, Weihua; Lin, Hui; Yu, Han-Qing; Liang, Liyuan; Sheng, Guo-Ping; Gu, Baohua

    2017-01-01

    Atmospheric deposition of mercury (Hg) to surface water is one of the dominant sources of Hg in aquatic environments and ultimately drives methylmercury (MeHg) toxin accumulation in fish. It is known that freshly deposited Hg is more readily methylated by microorganisms than aged or preexisting Hg; however the underlying mechanism of this process is unclear. We report that Hg bioavailability is decreased by photochemical reactions between Hg and dissolved organic matter (DOM) in water. Photo-irradiation of Hg-DOM complexes results in loss of Sn(II)-reducible (i.e. reactive) Hg and up to an 80% decrease in MeHg production by the methylating bacterium Geobacter sulfurreducens PCA. Loss of reactive Hg proceeded at a faster rate with a decrease in the Hg to DOM ratio and is attributed to the possible formation of mercury sulfide (HgS). These results suggest a new pathway of abiotic photochemical formation of HgS in surface water and provide a mechanism whereby freshly deposited Hg is readily methylated but, over time, progressively becomes less available for microbial uptake and methylation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Physical properties of the planet Mercury

    Science.gov (United States)

    Clark, Pamela E.

    1988-01-01

    The global physical properties of Mercury are summarized with attention given to its figure and orbital parameters. The combination of properties suggests that Mercury has an extensive iron-rich core, possibly with a still-functioning dynamo, which is 42 percent of the interior by volume. Mercury's three major axes are comparable in size, indicating that the planet is a triaxial ellipsoid rather than an oblate spheroid. In terms of the domination of its surface by an intermediate plains terrane, it is more Venus- or Mars-like; however, due to the presence of a large metallic magnetic core, its interior may be more earth-like.

  13. Magnetosphere, exosphere, and surface of Mercury

    International Nuclear Information System (INIS)

    Cheng, A.F.; Krimigis, S.M.; Johnson, R.E.; Lanzerotti, L.J.

    1987-01-01

    It is presently suggested in light of the atomic Na exosphere discovered for Mercury that this planet, like the Jupiter moon Io, is capable of maintaining a heavy ion magnetosphere. Na(+) ions from the exosphere are in this scenario accelerated to keV energies en route to making substantial contributions to the mass and energy budgets of the magnetosphere. Since Mercury's Na supply to the exosphere is primarily internal, it would appear that Mercury is losing its semivolatiles and that this process will proceed by way of photosputtering, which maintains an adequate Na-ejection rate from the planet's surface. 39 references

  14. Mercury Thermal Hydraulic Loop (MTHL) Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Felde, David K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Crye, Jason Michael [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wendel, Mark W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Yoder, Jr, Graydon L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Farquharson, George [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jallouk, Philip A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); McFee, Marshall T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pointer, William David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ruggles, Art E. [Univ. of Tennessee, Knoxville, TN (United States); Carbajo, Juan J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-03-01

    The Spallation Neutron Source (SNS) is a high-power linear accelerator built at Oak Ridge National Laboratory (ORNL) which incorporates the use of a flowing liquid mercury target. The Mercury Thermal Hydraulic Loop (MTHL) was constructed to investigate and verify the heat transfer characteristics of liquid mercury in a rectangular channel. This report provides a compilation of previously reported results from the water-cooled and electrically heated straight and curved test sections that simulate the geometry of the window cooling channel in the target nose region.

  15. Conditioning of spent mercury by amalgamation

    International Nuclear Information System (INIS)

    Yim, S. P.; Shon, J. S.; An, B. G.; Lee, H. J.; Lee, J. W.; Ji, C. G.; Kim, S. H.; Yoon, J. H.; Yang, M. S.

    2002-01-01

    Solidification by amalgamation was performed to immobilize and stabilize the liquid spent mercury. First, the appropriate metal and alloy which can convert liquid mercury into a solid form of amalgam were selected through initial tests. The amalgam form, formulated in optimum composition, was characterized and subjected to performance tests including compressive strength, water immersion, leachability and initial vaporization rate to evaluate mechanical integrity, durability and leaching properties. Finally, bench scale amalgamation trial was conducted with about 1 kg of spent mercury to verify the feasibility of amalgamation method

  16. determination of mercury content in milk powder

    International Nuclear Information System (INIS)

    Jovchev, M.; Grigorov, T.; Apostolov, D.

    1985-01-01

    Four samples of humanized full cream cow milk powder of Bulgarian origin for new-born, sucklings, small children and soured milk powder were activated for 18-24 h in a neutron flux of 5.10 12 , resp. 2.10 13 n/cm 2 .sec in quartz ampules. The samples were activated without preliminary lyophilization, thus avoiding possible mistakes from mercury losses. Ag-110m, being eliminated in the amalgam, was not an obstacle to the mercury determination. The results obtained for the mercury content are in the same order as in other investigations and many times lower than the admissible norm for foodstuffs - 50 ppb

  17. Article Commentary: Chelation Therapy for Mercury Poisoning

    Directory of Open Access Journals (Sweden)

    Rong Guan

    2009-01-01

    Full Text Available Chelation therapy has been the major treatment for heavy metal poisoning. Various chelating agents have been developed and tested for treatment of heavy metal intoxications, including mercury poisoning. It has been clearly shown that chelating agents could rescue the toxicity caused by heavy metal intoxication, but the potential preventive role of chelating agents against heavy metal poisoning has not been explored much. Recent paper by Siddiqi and colleagues has suggested a protective role of chelating agents against mercury poisoning, which provides a promising research direction for broader application of chelation therapy in prevention and treatment of mercury poisoning.

  18. A self-focusing mercury jet target

    CERN Document Server

    Johnson, C

    2002-01-01

    Mercury jet production targets have been studied in relation to antiproton production and, more recently, pion production for a neutrino factory. There has always been a temptation to include some self-focusing of the secondaries by passing a current through the mercury jet analogous to the already proven lithium lens. However, skin heating of the mercury causes fast vaporization leading to the development of a gliding discharge along the surface of the jet. This external discharge can, nevertheless, provide some useful focusing of the secondaries in the case of the neutrino factory. The technical complications must not be underestimated.

  19. MESSENGER'S First and Second Flybys of Mercury

    Science.gov (United States)

    Slavin, James A.

    2009-01-01

    The MESSENGER mission to Mercury offers our first opportunity to explore this planet's miniature magnetosphere since Mariner 10's brief fly-bys in 1974-5. The magnetosphere of Mercury is the smallest in the solar system with its magnetic field typically standing off the solar wind only approximately 1000 km above the surface. An overview of the MESSENGER mission and its January 14th and October 6th, 2008 close flybys of Mercury will be provided. Primary science objectives and the science instrumentation will be described. Initial results from MESSENGER will be discussed with an emphasis on the magnetic field and charged particle measurements.

  20. Mercury nano-trap for effective and efficient removal of mercury(II) from aqueous solution

    Science.gov (United States)

    Li, Baiyan; Zhang, Yiming; Ma, Dingxuan; Shi, Zhan; Ma, Shengqian

    2014-11-01

    Highly effective and highly efficient decontamination of mercury from aqueous media remains a serious task for public health and ecosystem protection. Here we report that this task can be addressed by creating a mercury ‘nano-trap’ as illustrated by functionalizing a high surface area and robust porous organic polymer with a high density of strong mercury chelating groups. The resultant porous organic polymer-based mercury ‘nano-trap’ exhibits a record-high saturation mercury uptake capacity of over 1,000 mg g-1, and can effectively reduce the mercury(II) concentration from 10 p.p.m. to the extremely low level of smaller than 0.4 p.p.b. well below the acceptable limits in drinking water standards (2 p.p.b.), and can also efficiently remove >99.9% mercury(II) within a few minutes. Our work therefore presents a new benchmark for mercury adsorbent materials and provides a new perspective for removing mercury(II) and also other heavy metal ions from contaminated water for environmental remediation.

  1. Solubility of helium in mercury for bubbling technology of the spallation neutron mercury target

    International Nuclear Information System (INIS)

    Hasegawa, S.; Naoe, T.; Futakawa, M.

    2010-01-01

    The pitting damage of mercury target container that originates in the pressure wave excited by the proton beam incidence becomes a large problem to reach the high-power neutron source in JSNS and SNS. The lifetime of mercury container is decreased remarkably by the pitting damage. As one of solutions, the pressure wave is mitigated by injecting the helium micro bubbles in mercury. In order to inject the helium micro bubbles into mercury, it is important to understand the characteristic of micro bubbles in mercury. The solubility of mercury-helium system is a key factor to decide bubbling conditions, because the disappearance behavior, i.e. the lifetime of micro bubbles, depends on the solubility. In addition, the bubble generation method is affected by it. Moreover, the experimental data related to the solubility of helium in mercury hardly exist. In this work, the solubility was obtained experimentally by measuring precisely the pressure drop of the gas that is facing to mercury surface. The pressure drop was attributed to the helium dissolution into mercury. Based on the measured solubility, the lifetime of micro bubbles and the method of the bubble generation is estimated using the solubility data.

  2. Mercury in mercury(II)-spiked soils is highly susceptible to plant bioaccumulation.

    Science.gov (United States)

    Hlodák, Michal; Urík, Martin; Matúš, Peter; Kořenková, Lucia

    2016-01-01

    Heavy metal phytotoxicity assessments usually use soluble metal compounds in spiked soils to evaluate metal bioaccumulation, growth inhibition and adverse effects on physiological parameters. However, exampling mercury phytotoxicity for barley (Hordeum vulgare) this paper highlights unsuitability of this experimental approach. Mercury(II) in spiked soils is extremely bioavailable, and there experimentally determined bioaccumulation is significantly higher compared to reported mercury bioaccumulation efficiency from soils collected from mercury-polluted areas. Our results indicate this is not affected by soil sorption capacity, thus soil ageing and formation of more stable mercuric complexes with soil fractions is necessary for reasonable metal phytotoxicity assessments.

  3. An eco-friendly oxidation of sulfide compounds

    Indian Academy of Sciences (India)

    An improved green route has been developed for the oxidation of sulfide compounds. Albendazole is converted to ricobendazole or albendazole sulfone using H₂O₂ as an oxidant and H₂O as the solvent. High yields of the corresponding products were obtained by carrying out the reaction at room temperature.

  4. The Complex Resistivity Spectrum Characteristics About Stratabound Sulfide Deposits

    Science.gov (United States)

    Dong, P.; Sun, B.; Wang, L.; Chen, Z.; Dong, Z.; Wu, Y.

    2010-12-01

    Complex resistivity method has become the key technique of deep prospecting, and widely applied in stratabound sulfide deposits which often form massive ores. However, the complex resistivity spectrum characteristics of stratabound sulfide deposits remains unknown. Through studying variation problem of two-dimensional polarization medium, deducing the differential equations and calculating formula,we applied Cole-Cole model to deduce the spectrum of complex resistivity based on the model of three-node and four-node finite element method, and programmed homologous procedure. We utilized the Earth Model of Geological Layers which has accurate analytical solution to test rationality and accuracy of our modeling. We applied the layer structure provided by drilling results in Chenmenshan copper mine,which is typical strata-bound sulfide deposits in Jiangxi province,China, and calculated the spectra of complex resistivity, then made comparison between modeled and measured values. We find good corellation between them. Our studies may have imporved the interpretation of complex resistivity data, which help apply complex resistivity methods of propecting on stratabound sulfide deposites.

  5. Luminescence in Sulfides: A Rich History and a Bright Future

    Directory of Open Access Journals (Sweden)

    Philippe F. Smet

    2010-04-01

    Full Text Available Sulfide-based luminescent materials have attracted a lot of attention for a wide range of photo-, cathodo- and electroluminescent applications. Upon doping with Ce3+ and Eu2+, the luminescence can be varied over the entire visible region by appropriately choosing the composition of the sulfide host. Main application areas are flat panel displays based on thin film electroluminescence, field emission displays and ZnS-based powder electroluminescence for backlights. For these applications, special attention is given to BaAl2S4:Eu, ZnS:Mn and ZnS:Cu. Recently, sulfide materials have regained interest due to their ability (in contrast to oxide materials to provide a broad band, Eu2+-based red emission for use as a color conversion material in white-light emitting diodes (LEDs. The potential application of rare-earth doped binary alkaline-earth sulfides, like CaS and SrS, thiogallates, thioaluminates and thiosilicates as conversion phosphors is discussed. Finally, this review concludes with the size-dependent luminescence in intrinsic colloidal quantum dots like PbS and CdS, and with the luminescence in doped nanoparticles.

  6. Rapid biosynthesis of cadmium sulfide (CdS) nanoparticles using ...

    African Journals Online (AJOL)

    Rapid biosynthesis of cadmium sulfide (CdS) nanoparticles using culture supernatants of Escherichia coli ATCC 8739, Bacillus subtilis ATCC 6633 and Lactobacillus ... The process of extracellular and fast biosynthesis may help in the development of an easy and eco-friendly route for the synthesis of CdS nanoparticles.

  7. 21 CFR 177.2490 - Polyphenylene sulfide resins.

    Science.gov (United States)

    2010-04-01

    ... Components of Articles Intended for Repeated Use § 177.2490 Polyphenylene sulfide resins. Polyphenylene... coatings of articles intended for repeated use in contact with food, in accordance with the following... are available from the Center for Food Safety and Applied Nutrition (HFS-200), Food and Drug...

  8. 40 CFR 425.04 - Applicability of sulfide pretreatment standards.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Applicability of sulfide pretreatment standards. 425.04 Section 425.04 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY General Provisions...

  9. 40 CFR 425.03 - Sulfide analytical methods and applicability.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Sulfide analytical methods and applicability. 425.03 Section 425.03 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY General Provisions...

  10. Estimation of bacterial hydrogen sulfide production in vitro

    Directory of Open Access Journals (Sweden)

    Amina Basic

    2015-06-01

    Full Text Available Oral bacterial hydrogen sulfide (H2S production was estimated comparing two different colorimetric methods in microtiter plate format. High H2S production was seen for Fusobacterium spp., Treponema denticola, and Prevotella tannerae, associated with periodontal disease. The production differed between the methods indicating that H2S production may follow different pathways.

  11. Carbon-supported iron and iron-molybdenum sulfide catalysts

    International Nuclear Information System (INIS)

    Ramselaar, W.L.T.M.

    1988-01-01

    The main objective was to describe the relations between the characteristics (composition and dispersion) of the actual sulfide phase and the catalytic activity. Attention was also paid to the influence of preparational aspects on these characteristics. The catalysts were characterized using in-situ Moessbauer spectroscopy down to 2.0 K. 254 refs.; 47 figs.; 22 tabs

  12. Impact of Iron Sulfide Transformation on Trichloroethylene Degradation

    Science.gov (United States)

    Trichloroethylene (TCE) is one of the most common and persistent groundwater contaminants encountered at hazardous waste sites around the world. A growing body of evidence indicates that iron sulfides play an important role in degrading TCE in natural environments and in enginee...

  13. Selective Sulfidation of Lead Smelter Slag with Sulfur

    Science.gov (United States)

    Han, Junwei; Liu, Wei; Wang, Dawei; Jiao, Fen; Qin, Wenqing

    2016-02-01

    The selective sulfidation of lead smelter slag with sulfur was studied. The effects of temperature, sulfur dosage, carbon, and Na salts additions were investigated based on thermodynamic calculation. The results indicated that more than 96 pct of zinc in the slag could be converted into sulfides. Increasing temperature, sulfur dosage, or Na salts dosage was conducive to the sulfidation of the zinc oxides in the slag. High temperature and excess Na salts would result in the more consumption of carbon and sulfur. Carbon addition not only promoted the selective sulfidation but reduced the sulfur dosage and eliminated the generation of SO2. Iron oxides had a buffering role on the sulfur efficient utilization. The transformation of sphalerite to wurtzite was feasible under reducing condition at high temperature, especially above 1273 K (1000 °C). The growth of ZnS particles largely depended upon the roasting temperature. They were significantly increased when the temperature was above 1273 K (1000 °C), which was attributed to the formation of a liquid phase.

  14. A physiologically based kinetic model for bacterial sulfide oxidation.

    Science.gov (United States)

    Klok, Johannes B M; de Graaff, Marco; van den Bosch, Pim L F; Boelee, Nadine C; Keesman, Karel J; Janssen, Albert J H

    2013-02-01

    In the biotechnological process for hydrogen sulfide removal from gas streams, a variety of oxidation products can be formed. Under natron-alkaline conditions, sulfide is oxidized by haloalkaliphilic sulfide oxidizing bacteria via flavocytochrome c oxidoreductase. From previous studies, it was concluded that the oxidation-reduction state of cytochrome c is a direct measure for the bacterial end-product formation. Given this physiological feature, incorporation of the oxidation state of cytochrome c in a mathematical model for the bacterial oxidation kinetics will yield a physiologically based model structure. This paper presents a physiologically based model, describing the dynamic formation of the various end-products in the biodesulfurization process. It consists of three elements: 1) Michaelis-Menten kinetics combined with 2) a cytochrome c driven mechanism describing 3) the rate determining enzymes of the respiratory system of haloalkaliphilic sulfide oxidizing bacteria. The proposed model is successfully validated against independent data obtained from biological respiration tests and bench scale gas-lift reactor experiments. The results demonstrate that the model is a powerful tool to describe product formation for haloalkaliphilic biomass under dynamic conditions. The model predicts a maximum S⁰ formation of about 98 mol%. A future challenge is the optimization of this bioprocess by improving the dissolved oxygen control strategy and reactor design. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Thioamides as collectors at flotation of sulfide minerals

    International Nuclear Information System (INIS)

    Fomin, B.M.; Solozhenkin, P.M.; Rukhadze, E.G.; Lyubavina, L.L.

    1976-01-01

    The collective properties of thioamides at flotation of number of sulfide minerals are considered. It is defined that studied thioamides fix on the surface of minerals with formation of appropriate complexes. The spectres of copper thioamides are studied by means of electron paramagnetic resonance and infrared spectroscopy.

  16. Iridium Sulfide and Ir Promoted Mo Based Catalysts.

    Czech Academy of Sciences Publication Activity Database

    Vít, Zdeněk

    2007-01-01

    Roč. 322, - (2007), s. 142-151 ISSN 0926-860X R&D Projects: GA ČR(CZ) GA104/06/0870 Institutional research plan: CEZ:AV0Z40720504 Keywords : iridium sulfide * IrMo catalyst * hydrodesulfurization Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.166, year: 2007

  17. Remediation of arsenic and lead with nanocrystalline zinc sulfide.

    Science.gov (United States)

    Piquette, Alan; Cannon, Cody; Apblett, Allen W

    2012-07-27

    Nanocrystalline (1.7 ± 0.3 nm) zinc sulfide with a specific surface area up to 360 m(2) g(-1) was prepared from the thermal decomposition of a single-source precursor, zinc ethylxanthate. Zinc ethylxanthate decomposes to cubic zinc sulfide upon exposure to temperatures greater than or equal to 125 °C. The resulting zinc sulfide was tested as a water impurity extractant. The target impurities used in this study were As(5+), As(3+), and Pb(2+). The reaction of the nanocrystalline ZnS with Pb(2+) proceeds as a replacement reaction where solid PbS is formed and Zn(2+) is released into the aqueous system. Removal of lead to a level of less than two parts per billion is achievable. The results of a detailed kinetics experiment between the ZnS and Pb(2+) are included in this study. Unlike the instance of lead, both As(5+) and As(3+) adsorb on the surface of the ZnS extractant as opposed to an ion-exchange process. An uptake capacity of > 25 mg g(-1) for the removal of As(5+) is possible. The uptake of As(3+) appears to proceed by a slower process than that of the As(5+) with a capacity of nearly 20 mg g(-1). The nanocrystalline zinc sulfide was extremely successful for the removal of arsenic and lead from simulated oil sand tailing pond water.

  18. Exploiting fields of gases containing hydrogen-sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Shevets, V.A.

    1980-01-01

    The anthology is devoted to problems of geology, hydrogeology, drilling, industrial development, and processing of gas and condensate at the Orenburg Gas-Chemical Complex. Reviews ways to develop the technology for further processing of hydrogen sulfide gas, as well as handling corrosion.

  19. Hydrogen sulfide release from dairy manure storages containing gypsum bedding

    Science.gov (United States)

    Recycled gypsum products can provide a cost-effective bedding alternative for dairy producers. Manufacturers report reduced odors, moisture and bacteria in the stall environment when compared to traditional bedding. Gypsum provides a sulfate source that can be converted to hydrogen sulfide under ana...

  20. Synthesis and photovoltaic application of coper (I) sulfide nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yue; Wadia, Cyrus; Ma, Wanli; Sadtler, Bryce; Alivisatos, A.Paul

    2008-06-24

    We present the rational synthesis of colloidal copper(I) sulfide nanocrystals and demonstrate their application as an active light absorbing component in combination with CdS nanorods to make a solution-processed solar cell with 1.6percent power conversion efficiency on both conventional glass substrates and flexible plastic substrates with stability over a 4 month testing period.