WorldWideScience

Sample records for earth phosphorus geochemistry

  1. HELGES: Helmholtz Laboratory for the Geochemistry of the Earth Surface

    OpenAIRE

    Friedhelm von Blanckenburg; Hella Wittmann; Schuessler, Jan A.

    2016-01-01

    New developments in Geochemistry during the last two decades have revolutionized our understanding of the processes that shape Earth's surface. Here, complex interactions occur between the tectonic forces acting from within the Earth and the exogenic forces like climate that are strongly modulated by biota and, increasingly today, by human activity. Within the Helmholtz Laboratory for the Geochemistry of the Earth Surface (HELGES) of the Helmholtz Centre Potsdam GFZ German Research Centre for...

  2. Geochemistry of colloid systems. For earth scientists

    NARCIS (Netherlands)

    Nickel, E.

    1979-01-01

    The second part of the title of this book gives an indication for whom it has been written. It is a real 'synthesizer'. Throughout ten chapters the reader is introduced into the highly complex matter of colloid chemistry and its role in geochemistry, pedology, oceanography, and geology.

  3. GEOCHEMISTRY

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    <正>20041015 Chen Ming (Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, Guangdong); Xie Xiande Geochemical Behavior of Alkaline Elements in the Deep Earth: Evidence from High -Pressure Minerals in Shocked Meteorites (Geochimica, ISSN 0379 - 1726, CN 44 -1398/P, 32(2), 2003, p. 161-166, 3 il-lus. , 30 refs. , with English abstract)

  4. GEOCHEMISTRY

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>20102226 Liu Congqiang(State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550002,China);Lang Yunchao Researches on Biogeochemical Processes and Nutrient Cycling in Karstic Ecological Systems,Southwest China:A review(Earth Science Frontiers,ISSN1005-2321,CN11-3370/P,16(6),2009,p.1-12,36 refs.)Key words:biogeochemistry,karst environmentBased on the previous studies,this paper introduces the researches on biogeochemical processes and nutrient cycling occurri

  5. HELGES: Helmholtz Laboratory for the Geochemistry of the Earth Surface

    Directory of Open Access Journals (Sweden)

    Friedhelm von Blanckenburg

    2016-08-01

    Full Text Available New developments in Geochemistry during the last two decades have revolutionized our understanding of the processes that shape Earth's surface. Here, complex interactions occur between the tectonic forces acting from within the Earth and the exogenic forces like climate that are strongly modulated by biota and, increasingly today, by human activity. Within the Helmholtz Laboratory for the Geochemistry of the Earth Surface (HELGES of the Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences, it is our goal to quantify the rates and fluxes of these processes in detail and to develop new techniques to fingerprint them over various temporal and spatial scales. We use mass spectrometry facilities to analyze metal stable isotopes, element concentrations and cosmogenic nuclides to fingerprint and quantify geomorphological changes driven by erosion and weathering processes. We use these novel geochemical tools, to quantify, for example, the recycling of metals in plants after their release during weathering of rocks and soils, soil formation and its erosion rates, and mechanisms and speed of sediment transport through drainage basins. Our research is thus dedicated towards understanding material turnover rates at the Earth's surface by using geochemical fingerprints.

  6. The Medical Geochemistry of Dusts, Soils, and Other Earth Materials

    Science.gov (United States)

    Plumlee, G. S.; Ziegler, T. L.

    2003-12-01

    "Town clenched in suffocating grip of asbestos"USA Today, article on Libby,Montana, February, 2000"Researchers find volcanoes are bad for your health… long after they finish erupting"University of WarwickPress Release, 1999"Toxic soils plague city - arsenic, lead in 5 neighborhoods could imperil 17,000 residents"Denver Post, 2002"Ill winds - dust storms ferry toxic agents between countries and even continents"Science News, 2002A quick scan of newspapers, television, science magazines, or the internet on any given day has a fairly high likelihood of encountering a story (usually accompanied by a creative headline such as those above) regarding human health concerns linked to dusts, soils, or other earth materials. Many such concerns have been recognized and studied for decades, but new concerns arise regularly.Earth scientists have played significant roles in helping the medical community understand some important links between earth materials and human health, such as the role of asbestos mineralogy in disease (Skinner et al., 1988; Ross, 1999; Holland and Smith, 2001), and the role of dusts generated by the 1994 Northridge, California, earthquake in an outbreak of Valley Fever ( Jibson et al., 1998; Schneider et al., 1997).Earth science activities tied to health issues are growing (Skinner and Berger, 2003), and are commonly classified under the emerging discipline of medical geology (Finkelman et al., 2001; Selinus and Frank, 2000; Selinus, in press).Medical geochemistry (also referred to as environmental geochemistry and health: Smith and Huyck (1999), Appleton et al. (1996)) can be considered as a diverse subdiscipline of medical geology that deals with human and animal health in the context of the Earth's geochemical cycle ( Figure 1). Many medical geochemistry studies have focused on how chemical elements in rocks, soils, and sediments are transmitted via water or vegetation into the food chain, and how regional geochemical variations can result in disease

  7. GEOCHEMISTRY

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>20101501 Dou Chuanwei (State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China); Lian Bin Microbial Weathering of Calcite by Rock-Inhabiting Fungi, biogenic processes

  8. Calcination-Digestion-Desliming of Phosphorus Ore Bearing Rare Earth

    Institute of Scientific and Technical Information of China (English)

    Zhang Qin; Zhang Jie; Wang Jing; Qiu Yue qin

    2004-01-01

    The recoveries of phosphorus and RE of ore from Zhijin in Guizhou were studied.The influences of the calcination temperature, resident time, the digested time and water volume of the calcinating on concentrate yield by desliming were also investigated by orthogonal design.Appropriate calcination temperature is initial condition that makes carbonate mineral decomposition.The recovery of phosphorus is 83.02% and rare earth is 90.56% in phosphorus concentrate when calcined temperature is 900 ℃, other conditions include: calcined time is 30 min, digestion water volume is 300 ml, digestion time is 20 min.The results show that the pre-treatment of the ore is favorable for the separation and enrichment of rare earth from phosphorus ore, and a process of calcination-digestion-desliming was promised.

  9. GEOCHEMISTRY

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    20150115Guo Haifeng(State Key Laboratory of Isotope Geochemistry,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,China);Xia Xiaoping LA-MC-ICPMS In-Situ Boron Isotope Analyses of Tourmalines from the Shangbao Granites(Southern Hunan Province)and Its Geological Significance(Geochimica,ISSN0379-1726,CN44-1398/P,43(1),2014,p.11-19,3illus.,1table,66refs.)Key words:micro-zone analysis,boron isotopes,Hunan Province LA-MC-ICPMS tourmaline in-situ

  10. GEOCHEMISTRY

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>20140115 Bian Youyan(Key Laboratory of Marginal Sea Geology,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,China);Chen Duofu Cold Seep Activities Recorded by Geochemical Characteristics of Authigenic Carbonates from Green Canyon 140,Gulf of Mexico(Geochimica,ISSN0379-1726,CN44-1398/P,42(3),2013,p.212-220,4illus.,2tables,49refs.)Key words:carbonate rocks,lithogeochemistry,Mexico

  11. Geochemistry of Rare Earth Elements in Aktishikan Gold Deposit, Xinjiang

    Institute of Scientific and Technical Information of China (English)

    袁峰; 周涛发; 岳书仓

    2002-01-01

    The characteristics and the models of rare earth elements in the geolo gical bodies and the hydrothermal water balanced with the adamellite were compre h ensively studied in Aktishikan gold deposit,Nurt area of Altay,Xinjiang.And th e behavior of rare earth elements during metasomatic alteration was discussed by using the isocon method of Grant.The results show that the rare earth elements a re inert during metasomatic alteration,the hydrothermal water has no relation t o the magmatic water,and the gold material sources mainly stem from the wall rock.

  12. GEOCHEMISTRY

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    20160133Bao Liran(Southeast Sichuan Geological Group,Chongqing Bureau of Geology and Minerals Exploration,Chongqing400038,China);Gong Yuanyuan Element Geochemical Baseline and Distributions in Soil in Chongqing West Economic Zone,China(Earth

  13. Tungsten geochemistry and implications for understanding the Earth's interior

    Science.gov (United States)

    Arevalo, Ricardo; McDonough, William F.

    2008-08-01

    The concentration of tungsten (W) in basaltic melts provides a window into the behavior of this element during core-mantle separation, crust formation, silicate differentiation, and potentially core-mantle interaction. We have analyzed an extensive suite of modern basalts ( n = 86) for their trace element chemistry via laser ablation ICP-MS, with barium (Ba), thorium (Th), uranium (U), and W concentrations typically determined to ≤ 5% (2 σ) uncertainty. We find that the partitioning behavior of U mirrors that of W during basalt genesis, whereas Ba and Th both behave more incompatibly. The W/U ratio of our complete sample suite (0.65 ± 0.45, 2 σ) is representative of the mean modern mantle, and is indistinguishable from that of mid-ocean ridge basalts (W/U MORB = 0.65 ± 0.41, n = 52), ocean island basalts (W/U OIB = 0.63 ± 0.07, n = 10), and back-arc basin basalts (W/U BABB = 0.62 ± 0.09, n = 12). This ratio is also consistent with the W/U ratio of the continental crust, and thus represents the W/U ratio of the entire silicate portion of the Earth. Assuming a concentration of 20 ± 8 (2 σ) ng/g U in the bulk silicate Earth, the abundance of W in the silicate Earth is 13 ± 10 ng/g. Following mass balance, this implies a mean modern mantle and core composition of 8.3 ± 7.1 ng/g W and 500 ± 120 ng/g W, respectively. Additionally, the MORB source is modeled to contain approximately 3.0 ± 2.3 ng/g W, indicating a four-fold depletion of the highly incompatible elements in the MORB source relative to the silicate Earth. Although both the isotopic composition of W and the constancy of the silicate Earth W/U ratio allow for potential insight into core-mantle exchange, both of these proxies are extremely dependent on the chemical composition of the source. A case study of three Hawaiian picrites with enrichments in 186Os- 187Os but terrestrial ɛ182W can be explained by: i) a lack of a core component in the Hawaiian "plume," ii) crustal contamination, or iii) a

  14. GEOCHEMISTRY

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20112218 Kang Zhiqiang (College of Earth Sciences,Guilin University of Technology, Guilin 541004,China);Feng Zuohai Reliability Comparison of Al-in-Hornblende and Biotite Barometer-A Case Study of Guposhan - Huashan Granite in North Guangxi(Journal of Guilin University of Technology,1674-9057, 45-1375/N,30(4),2010,p.474-479,3 illus.,3tables 14refs.)

  15. GEOCHEMISTRY

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20110070 Chen Gen(College of Earth Science,Chengdu University of Technology,Chengdu 610059,China);Zhu Zhengjie Advances in Research into Carbon and Oxygen Isotopes of Lacustrine Carbonate(Acta Geologica Sichuan,ISSN1006-0995,CN51-1273/P,30(1),2010,p.75-78,1 illus.,5 refs.)Key words:carbonate sediments,carbon isotopes,oxygen isotopes This paper deals with control factors and environment significance of δ13C and δ18O values of lacustrine authigenic carbonate and makes an

  16. Phosphorus geochemistry of recent sediments in the South Basin of Lake Winnipeg

    Science.gov (United States)

    Mayer, T.; Simpson, S.L.; Thorleifson, L.H.; Lockhart, W.L.; Wilkinson, Philip M.

    2006-01-01

    Lake Winnipeg supports the largest commercial fishery on Canadian Prairies. It has been influenced by a variety of environmental forces and anthropogenic activities. To gain a better understanding of recent changes in nutrient status of the lake, it is important to reconstruct its previous history from sedimentary records. Lacustrine sediments are known to be an important sink of many dissolved and suspended substances, including phosphorus, hence, they provide a permanent historical record of changes occurring in the lake. These changes may be induced by natural factors or by anthropogenic activities in the watershed. Phosphorus profiles from dated sediment cores collected in 1999 and 1994 from the South Basin of Lake Winnipeg were investigated to determine phosphorus enrichment in recent sediments. To interpret the nutrient status and depositional conditions responsible for the trends in total phosphorus, three operationally defined forms of phosphorus (P) were determined: non-apatite inorganic P, apatite P, and organic P. Significant increases in sediment phosphorus concentrations were observed in the uppermost 20 cm of the cores and several anomalies were observed at depth. A doubling in total phosphorus relative to aluminum over the last fifty years is largely due to increases in the non-apatite inorganic fraction, suggesting that much of sedimentary phosphorus increase is attributable to changes in the nutrient status of the water column related to anthropogenic inputs. Organic phosphorus exhibits a subtle increase in the upper 20 cm of the gravity cores, likely due to increases in the primary productivity of the lake. Except for the slight increase in deeper sediments, apatite phosphorus, which is thought to be of detrital origin, remained fairly constant over the length of the cores. Anomalous spikes in phosphorus concentrations deeper in the cores, comprised mainly of the non-apatite inorganic phosphorus fraction, likely resulted from natural variation in

  17. Building the EarthChem System for Advanced Data Management in Igneous Geochemistry

    Science.gov (United States)

    Lehnert, K.; Walker, J. D.; Carlson, R. W.; Hofmann, A. W.; Sarbas, B.

    2004-12-01

    Several mature databases of geochemical analyses for igneous rocks are now available over the Internet. The existence of these databases has revolutionized access to data for researchers and students allowing them to extract data sets customized to their specific problem from global data compilations with their desktop computer within a few minutes. Three of the database efforts - PetDB, GEOROC, and NAVDAT - have initiated a collaborative effort called EarthChem to create better and more advanced and integrated data management for igneous geochemistry. The EarthChem web site (http://www.earthchem.org/) serves as a portal to the three databases and information related to EarthChem activities. EarthChem participants agreed to establish a dialog to minimize duplication of effort and share useful tools and approaches. To initiate this dialog, a workshop was run by EarthChem in October, 2003 to discuss cyberinfrastructure needs in igneous geochemistry (workshop report available at the EarthChem site). EarthChem ran an information booth with database and visualization demonstrations at the Fall 2003 AGU meeting (and will have one in 2004) and participated in the May 2003 GERM meeting in Lyon, France where we provided the newly established Publishers' Round Table a list of minimum standards of data reporting to ease the assimilation of data into the databases. Aspects of these suggestions already have been incorporated into new data policies at Geochimica et Cosmochimica Acta and Chemical Geology (Goldstein et al. 2004), and are under study by the Geological Society of America. EarthChem presented its objectives and activities to the Solid Earth Sciences community at the Annual GSA Meeting 2003 (Lehnert et al, 2003). Future plans for EarthChem include expanding the types and amounts of data available from a single portal, giving researchers, faculty, students, and the general public the ability to search, visualize, and download geochemical and geochronological data for a

  18. Hydro-geochemistry and retention of phosphorus in drainage filters and constructed wetlands

    DEFF Research Database (Denmark)

    Canga, Eriona; Kjærgaard, Charlotte; Iversen, Bo Vangsø

    in drainage water to below environmental threshold values (pollutants as well as the potential for recycling P saturated filters is also investigated......Despite substantial efforts, the leaching of nutrients from agricultural land is still a serious and costly environmental problem in Denmark and elsewhere. The quality goals of the European Water Framework Directive (WFD) for the aquatic environment require a substantial reduction of diffuse...... nutrient loads from farmland in Denmark. Tile drains and ditches connect fields to receiving waters and act as subsurface highways for both soluble and particulate phosphorus (P), nitrogen (N) as well as other agricultural contaminants. Drainage losses of nutrients contribute to estimated 33% of total P...

  19. Rare earth element geochemistry of outcrop and core samples from the Marcellus Shale.

    Science.gov (United States)

    Noack, Clinton W; Jain, Jinesh C; Stegmeier, John; Hakala, J Alexandra; Karamalidis, Athanasios K

    2015-01-01

    In this work, the geochemistry of the rare earth elements (REE) was studied in eleven outcrop samples and six, depth-interval samples of a core from the Marcellus Shale. The REE are classically applied analytes for investigating depositional environments and inferring geochemical processes, making them of interest as potential, naturally occurring indicators of fluid sources as well as indicators of geochemical processes in solid waste disposal. However, little is known of the REE occurrence in the Marcellus Shale or its produced waters, and this study represents one of the first, thorough characterizations of the REE in the Marcellus Shale. In these samples, the abundance of REE and the fractionation of REE profiles were correlated with different mineral components of the shale. Namely, samples with a larger clay component were inferred to have higher absolute concentrations of REE but have less distinctive patterns. Conversely, samples with larger carbonate fractions exhibited a greater degree of fractionation, albeit with lower total abundance. Further study is necessary to determine release mechanisms, as well as REE fate-and-transport, however these results have implications for future brine and solid waste management applications.

  20. Electrochemical studies of iron meteorites: phosphorus redox chemistry on the early Earth

    Science.gov (United States)

    Bryant, David E.; Greenfield, David; Walshaw, Richard D.; Evans, Suzanne M.; Nimmo, Alexander E.; Smith, Caroline L.; Wang, Liming; Pasek, Matthew A.; Kee, Terence P.

    2009-01-01

    The mineral schreibersite, (Fe,Ni)3P, a ubiquitous component of iron meteorites, is known to undergo anoxic hydrolytic modification to afford a range of phosphorus oxyacids. H-phosphonic acid (H3PO3) is the principal hydrolytic product under hydrothermal conditions, as confirmed here by 31P-NMR spectroscopic studies on shavings of the Seymchan pallasite (Magadan, Russia, 1967), but in the presence of photochemical irradiation a more reduced derivative, H-phosphinic (H3PO2) acid, dominates. The significance of such lower oxidation state oxyacids of phosphorus to prebiotic chemistry upon the early Earth lies with the facts that such forms of phosphorus are considerably more soluble and chemically reactive than orthophosphate, the commonly found form of phosphorus on Earth, thus allowing nature a mechanism to circumvent the so-called Phosphate Problem. This paper describes the Galvanic corrosion of Fe3P, a hydrolytic modification pathway for schreibersite, leading again to H-phosphinic acid as the key P-containing product. We envisage this pathway to be highly significant within a meteoritic context as iron meteorites are polymetallic composites in which dissimilar metals, with different electrochemical potentials, are connected by an electrically conducting matrix. In the presence of a suitable electrolyte medium, i.e., salt water, galvanic corrosion can take place. In addition to model electrochemical studies, we also report the first application of the Kelvin technique to map surface potentials of a meteorite sample that allows the electrochemical differentiation of schreibersite inclusions within an Fe:Ni matrix. Such experiments, coupled with thermodynamic calculations, may allow us to better understand the chemical redox behaviour of meteoritic components with early Earth environments.

  1. Impact during the proterozoic era possibly inundated the earth with phosphorus

    Science.gov (United States)

    Sisodia, M. S.

    2009-07-01

    The stromatolites of the Precambrian Aravalli Supergroup outcropping around Udaipur, Rajasthan, India are classified into two distinct lithofacies: the older carbonate stromatolites facies and the younger phosphate-bearing stromatolite facies. Phosphate-bearing stromatolites of the same age have been reported from China, Russia and Australia. The phosphate-bearing stromatolites of Udaipur show fossil cyanobacteria. These cyanobacteria grew luxuriantly in the absence of any competitors and accumulated abnormal amounts of phosphorus from the novo phosphorus-rich environment, eventually forming a workable phosphate deposit owing to their post-mortem alteration. There is a sharp and abrupt contact between the two facies. This sharp contact or diastem underlying the phosphate-bearing stromatolites is of extreme importance as it denotes a stratigraphic hiatus characterizing a period of overall change in the environment. This change could be due to some catastrophic episode. The Earth during its geologic history has been subjected to several such episodes caused by certain high-energy events, such as impacts by extraterrestrial bodies. These impacts caused mass extinctions as occurred at the Permian-Triassic or Cretaceous-Tertiary boundary or the emergence of new flora and fauna as occurred at the Precambrian-Cambrian boundary. It is therefore argued that the diastem noted between carbonate and phosphate-bearing stromatolites is possibly due to an impact that inundated the Earth with phosphorus. Phosphorus is a key constituent of proteins, which are the major repository of chemical energy for metabolism. Its abundance after this event triggered the emergence of new advanced species.

  2. Processing of Phosphorus Slag with Recovery of Rare Earth Metals and Obtaining Silicon Containing Cake

    Science.gov (United States)

    Karshigina, Zaure; Abisheva, Zinesh; Bochevskaya, Yelena; Akcil, Ata; Sharipova, Aynash; Sargelova, Elmira

    2016-10-01

    The present research is devoted to the processing of slag generating during the yellow phosphorus production. In this paper are presented studies on leaching of phosphorus production slag by nitric acid with recovery of rare earth metals (REMs) into solution. REMs recovery into the solution achieved 98 % during the leaching process with using 7.5 mol/L of HNO3, liquid-to-solid ratio is 2.6:1, temperature is 60°C, process duration is 1 hour and stirrer speed is 500 rpm. Behaviour during the leaching of associated components such as calcium, aluminium, and iron was studied. After the leaching cake contains ∼⃒75-85 % of SiO2 and it might be useful for obtaining of precipitated silicon dioxide. With the purpose of separation from the impurities, recovery and concentrating of REMs, the obtained solution after leaching was subjected to extraction processing methods. The influence of ratio of organic and aqueous phases (O: A) on the extraction of rare earth metals by tributyl phosphate (TBP) with concentrations from 20 up to 100 % was studied. The REMs extraction with increasing TBP concentration under changes O:A ratio from 1:20 down to 1:1 into the organic phase from the solutions after nitric acid leaching increased from 22.2 up to 99.3%. The duration effect of REMs extraction process was studied by tributyl phosphate. It is revealed that with increasing of duration of the extraction process from 10 to 30 minutes REMs recovery into the organic phase almost did not changed. The behaviour of iron in the extraction process by TBP was studied. It was found that such accompanying components as calcium and aluminium by tributyl phosphate didn't extracted. To construct isotherm of REMs extraction of by tributyl phosphate was used variable volume method. It was calculated three-step extraction is needed for REMs recovery from the solutions after nitric acid leaching of phosphorus production slag. The process of the three-steps counter current extraction of rare earth

  3. Rare earth element geochemistry of Cambrian phosphorites from the Yangtze Region

    Institute of Scientific and Technical Information of China (English)

    CHEN Jiyan; YANG Ruidong; WEI Huairui; GAO Junbo

    2013-01-01

    Analysis on P2O5 and REE (rare earth elements) in basal Cambrian phosphorites from the Yangtze Region,showed that the phosphofites from Bailongtan in Yunnan Province,Zhijin,Jinsha,Xishui,Zunyi,Tianzhu and Tongren in Guizhou Province,Shangrao in Jiangxi Province,Jiangshan in Zhejiang Province and Nanjing in Jiangsu Province contained high REE contents in phosphorites,especially those from Tianzhu and Tongren in Guizhou Province,Shangrao in Jiangxi Province,Jiangshan in Zhejiang Province and Nanjing in Jiangsu Province.Among them,the highest REE contents reached up to 1361.59× 10-6 and P2O5 contents up to 29.45%.In contrast,phosphofites from Kaiyang,Qingzhen and Zhenyuan in Guizhou Province had relatively low total REE contents and low P2O5 contents,with the lowest total REE content of 53.19× 10-6,and the lowest P2O5 content of 0.07%.REE contents exhibited a positive correlation with phosphorous contents,indicating a close genetic relationship between REE and phosphorous element.The main reason was the difference of the sedimentary environments and the contents of phosphorous and REE in deep water mass formed in upwelling currents,at an upper slope facies (Slu) in reducing condition due to relatively closed sedimentary environment.It was very difficult for the upswelling phosphorous and REE to deposit,massive phosphorous deposits were hard to be formed.At a deep water ramp facies (DRa) in the ascending process of currents,phosphorus and REE underwent differentiation rather than sedimentation.Consequently,the contents of P2O5 sediments and REE were low.At a shallow water ramp facies (including shoals and tidal fiats) (SRa),with active seawater circulation and phosphatic supplement,sunny weather,high nutrition and rapid growth of algae,were benefitial for the physical enrichment of carbonate sediments.Therefore,massive phosphorite deposits were easy to be formed with abundant REE minerals,and finally turned into high REE beating phosphorous deposits.

  4. Using rare earth elements to control phosphorus and track manure in runoff.

    Science.gov (United States)

    Buda, Anthony R; Church, Clinton; Kleinman, Peter J A; Saporito, Lou S; Moyer, Barton G; Tao, Liang

    2010-01-01

    Concern over the enrichment of agricultural runoff with phosphorus (P) from land applied livestock manures has prompted the development of manure amendments that minimize P solubility. In this study, we amended poultry, dairy, and swine manures with two rare earth chlorides, lanthanum chloride (LaCl(3).7H(2)O) and ytterbium chloride (YbCl(3).6H(2)O), to evaluate their effects on P solubility in the manure following incubation in the laboratory as well as on the fate of P and rare earth elements (REEs) when manures were surface-applied to packed soil boxes and subjected to simulated rainfall. In terms of manure P solubility, La:water-extractable P (WEP) ratios close to 1:1 resulted in maximum WEP reduction of 95% in dairy manure and 98% in dry poultry litter. Results from the runoff study showed that REE applications to dry manures such as poultry litter were less effective in reducing dissolved reactive phosphorus (DRP) in runoff than in liquid manures and slurries, which was likely due to mixing limitations. The most effective reductions of DRP in runoff by REEs were observed in the alkaline pH soil, although reductions of DRP in runoff from the acidic soil were still >50%. Particulate REEs were strongly associated with particulate P in runoff, suggesting a potentially useful role in tracking the fate of P and other manure constituents from manure-amended soils. Finally, REEs that remained in soil following runoff had a tendency to precipitate WEP, especially in soils receiving manure amendments. The findings have valuable applications in water quality protection and the evaluation of P site assessment indices.

  5. Geochemistry of Rare Earth Elements in Lamprophyres in Laowangzhai Gold Orefield, Yunnan Province

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Lamprophyres, widely distributed in the Laowangzhai gold orefield, Yunnan Province, China, and closely related to gold mineralization in time and space, can be distinguished into three kinds: the fresh(weakly altered), the altered, and the mineralized lamprophyres. These lamprophyres in the orefield are similar in the range of REE contents and REE patterns, but definitely different in parameters of LRE/HRE, NLa/Yb etc. The geochemistry of REE in fresh lamprophyre shows that the rock is a product of different partial melting of the enriched mantle. Calculation results of mass balance of REE activity regularity in the process of alteration and mineralization of the lamprophyres in the orefield shows that the altering fluids and mineralizing fluids contain REE, and these fluids are mainly the products of mantle degassing and magma degassing during the lamprophyric magmatism.

  6. Geochemistry of Rare Earth Elements in Aktishikan Gold Deposit,Xinjiang

    Institute of Scientific and Technical Information of China (English)

    袁峰; 周涛发; 等

    2002-01-01

    The characteristics and the models of rare earth elements in the geological bodies and the hydrothermal water balancel with the adamellite were comprehensivealy studied in Aktishikan gold deposit,Nurt area of Altay,Xinjiang,And the behavior of rare earth elements during metasomatic alteration was discussed by using the isocon method of Grant,The results show that the rare earth elements are inert during metasomatic alteration,the hydrotheraml water has no relation to the magmatic water,and the gold material sources mainly stem from the wall rock.

  7. Geochemistry of Rare Earth Elements (REE) in the Weathered Crusts from the Granitic Rocks in Sulawesi Island, Indonesia

    Institute of Scientific and Technical Information of China (English)

    Adi Maulana; Kotaro Yonezu; Koichiro Watanabe

    2014-01-01

    We report for the first time the geochemistry of rare earth elements (REE) in the weath-ered crusts of I-type and calc-alkaline to high-K (shoshonitic) granitic rocks at Mamasa and Palu re-gion, Sulawesi Island, Indonesia. The weathered crusts can be divided into horizon A (lateritic profile) and B (weathered horizon). Quartz, albite, kaolinite, halloysite and montmorrilonite prevail in the weathered crust. Both weathered profiles show that the total REE increased from the parent rocks to the horizon B but significantly decrease toward the upper part (horizon A). LREE are enriched toward the upper part of the profile as shown by La/YbN value. However, HREE concentrations are high in horizon B1 in Palu profile. The total REE content of the weathered crust are relatively elevated com-pared to the parent rocks, particularly in the lower part of horizon B in Mamasa profile and in horizon B2 in Palu profile. This suggests that REE-bearing accessory minerals may be resistant against weath-ering and may remain as residual phase in the weathered crusts. The normalized isocon diagram shows that the mass balance of major and REE components between each horizon in Mamasa and Palu weathering profile are different. The positive Ce anomaly in the horizon A of Mamasa profile indicated that Ce is rapidly precipitated during weathering and retain at the upper soil horizon.

  8. Evidence from Sardinian basalt geochemistry for recycling of plume heads into the Earth's mantle.

    Science.gov (United States)

    Gasperini, D; Blichert-Toft, J; Bosch, D; Del Moro, A; Macera, P; Télouk, P; Albarède, F

    2000-12-07

    Up to 10 per cent of the ocean floor consists of plateaux--regions of unusually thick oceanic crust thought to be formed by the heads of mantle plumes. Given the ubiquitous presence of recycled oceanic crust in the mantle source of hotspot basalts, it follows that plateau material should also be an important mantle constituent. Here we show that the geochemistry of the Pleistocene basalts from Logudoro, Sardinia, is compatible with the remelting of ancient ocean plateau material that has been recycled into the mantle. The Sr, Nd and Hf isotope compositions of these basalts do not show the signature of pelagic sediments. The basalts' low CaO/Al2O3 and Ce/Pb ratios, their unradiogenic 206Pb and 208Pb, and their Sr, Ba, Eu and Pb excesses indicate that their mantle source contains ancient gabbros formed initially by plagioclase accumulation, typical of plateau material. Also, the high Th/U ratios of the mantle source resemble those of plume magmas. Geochemically, the Logudoro basalts resemble those from Pitcairn Island, which contain the controversial EM-1 component that has been interpreted as arising from a mantle source sprinkled with remains of pelagic sediments. We argue, instead, that the EM-1 source from these two localities is essentially free of sedimentary material, the geochemical characteristics of these lavas being better explained by the presence of recycled oceanic plateaux. The storage of plume heads in the deep mantle through time offers a convenient explanation for the persistence of chemical and mineralogical layering in the mantle.

  9. Geochemistry of some rare earth elements in groundwater, Vierlingsbeek, the Netherlands

    NARCIS (Netherlands)

    Janssen RPT; Verweij W; Versteegh JFM; LWD

    1997-01-01

    Speciation calculations were carried out on groundwater samples to shed more light on the chemical processes of rare earth elements (REE). These samples were taken from seven boreholes at several depths near the drinking water pumping station, Vierlingsbeek, The Netherlands. Complexation and precip

  10. Spherical disharmonics in the Earth sciences and the spatial solution: Ridges, hotspots, slabs, geochemistry and tomography correlations

    Science.gov (United States)

    Ray, Terrill W.; Anderson, Don L.

    1994-01-01

    There is increasing use of statistical correlations between geophysical fields and between geochemical and geophysical fields in attempts to understand how the Earth works. Typically, such correlations have been based on spherical harmonic expansions. The expression of functions on the sphere as spherical harmonic series has many pitfalls, especially if the data are nonuniformly and/or sparsely sampled. Many of the difficulties involved in the use of spherical harmonic expansion techniques can be avoided through the use of spatial domain correlations, but this introduces other complications, such as the choice of a sampling lattice. Additionally, many geophysical and geochemical fields fail to satisfy the assumptions of standard statistical significance tests. This is especially problematic when the data values to be correlated with a geophysical field were collected at sample locations which themselves correlate with that field. This paper examines many correlations which have been claimed in the past between geochemistry and mantle tomography and between hotspot, ridge, and slab locations and tomography using both spherical harmonic coefficient correlations and spatial domain correlations. No conclusively significant correlations are found between isotopic geochemistry and mantle tomography. The Crough and Jurdy (short) hotspot location list shows statistically significant correlation with lowermost mantle tomography for degree 2 of the spherical harmonic expansion, but there are no statistically significant correlations in the spatial case. The Vogt (long) hotspot location list does not correlate with tomography anywhere in the mantle using either technique. Both hotspot lists show a strong correlation between hotspot locations and geoid highs when spatially correlated, but no correlations are revealed by spherical harmonic techniques. Ridge locations do not show any statistically significant correlations with tomography, slab locations, or the geoid; the

  11. Iron oxides, divalent cations, silica, and the early earth phosphorus crisis

    DEFF Research Database (Denmark)

    Jones, C.; Nomosatryo, S.; Crowe, S.A.;

    2015-01-01

    and silica content of BIFs, we estimate that seawater in the Archean and early Proterozoic Eons likely contained 0.04–0.13 µM phosphorus, on average. These phosphorus limiting conditions could have favored primary production through photoferrotrophy at the expense of oxygenic photosynthesis until upwelling......As a nutrient required for growth, phosphorus regulates the activity of life in the oceans. Iron oxides sorb phosphorus from seawater, and through the Archean and early Proterozoic Eons, massive quantities of iron oxides precipitated from the oceans, producing a record of seawater chemistry...

  12. Rare earth elements geochemistry in springs from Taftan geothermal area SE Iran

    Science.gov (United States)

    Shakeri, Ata; Ghoreyshinia, Sayedkazem; Mehrabi, Behzad; Delavari, Morteza

    2015-10-01

    Concentrations of rare earth elements (REEs) were determined in springs and andesitic-dacitic rocks of Taftan geothermal field. Hydrochemical results of major ions indicate that thermal springs are Na-SO4-Cl and Ca-SO4-Cl types. Concentrations of REEs are in ranges of 10- 4 to 1.2 and 49 to ~ 62 times of chondrite for springwater and rock samples, respectively. The thermal (STS and TTS) and the cold (APS) springs with low pH values exhibit a very high REE contents (0.64 to 3.15 mg/l). Saturation index indicates that Fe and Al phases can control dissolved REE concentration in FTS and PF cold springs. The speciation of REE complexes indicates dominant presence of LnSO4+ and free ion in the Taftan thermal springs. In APS cold spring with pH ~ 4, fluoride complexes are dominate over the free ion and sulfate species, while in PF and FTS cold springs with pH 6.4 and 7, respectively, carbonate complexes (LnCO3+) are predominant species. Chondrite-normalized pattern for the low-pH waters show very distinctive gull-wing patterns, characteristic feature of acid-sulfate geothermal systems, and are similar to those of the host rocks. Chemical characteristics of rare earth elements in spring and volcanic rock samples indicate that REEs are originated from the andesitic-dacitic host rocks. Whole-rock-normalized REE patterns and petrographic evidences show that rare earth elements leached mainly from marginal alteration of minerals and matrix decomposition in volcanic rocks. In chondrite-normalized REE patterns, significant negative Eu anomaly in the cold springs compare to the thermal and acidic springs indicates that alteration of plagioclase is more intense in the later, corresponding to increasing in temperature and acidic state of reactant water.

  13. Role of Phosphorus Minerals in the Origin of Life on Earth

    Science.gov (United States)

    Gull, M.; Pasek, M. A.

    2013-12-01

    In the origin of life, phosphorus (P) plays a vital role as it is a key biologic element (1). However, a big question still remains as to how P was incorporated into the first biomolecules as the availability of dissolved P in water is low. Orthophosphate minerals such as apatite, whitelockite and monetite are the major carriers of phosphate on Earth, but these are poorly soluble in water and are inert. The recent discovery of phosphite in Archean rocks (2) suggests that it is likely that some other source of P was present on the early Earth which could very well mix with Hadean Ocean to generate biomolecules. The meteoritic mineral schreibersite (SC thereafter) may have provided reduced P that would corrode into water and generate reactive inorganic P. In this study we present the significance of some important P minerals including apatite, whitelockite, monazite, struvite, monetite and meteoritic mineral SC (or its synthetic analogue Fe3P). Two major aspects of these P minerals were studied; first the release of P into water and second whether phosphorylation of organic compound (glycerol) could be carried out. It was seen all the phosphate minerals such as apatite, whitelockite, monazite and monetite when heated (65-75oC for 8-10 days) with an aqueous solution of 0.5 M glycerol gave no prominent phosphorylated products (P31NMR & mass spectrometry) and released very little amount of phosphate into water and remained inert. Struvite on heating with glycerol gave around 8-10 % of glycerol monophosphates along with phosphate release in the water. When SC (or Fe3P) was heated in an aqueous solution of glycerol it not only yielded 3-6 % glycerol monophosphates but also some glycerol-di-phosphate along with rich species of inorganic P compounds. SC from the meteorite Seymchan also demonstrated phosphorylation of glycerol. Since the prebiotic role of struvite mineral as a prebiotic P mineral is not clearly known (3), this suggests SC was a potential prebiotic P source

  14. Behaviors of Rare Earths during Fluid-Rock Interaction and Its Significance of Geochemistry

    Institute of Scientific and Technical Information of China (English)

    凌其聪; 刘丛强

    2001-01-01

    Rare earths in ores, altered and unaltered sericite phyllite, altered and unaltered dacite porphyry were determined in order to examine behaviors of rare earths in hydrothermal alteration associating with ore-forming processes of Yinshan deposit. It is not sufficient to show the mobility only by the absolute abundance of trace elements changes before and after alteration. This can simply result from dilution or concentration if other elements are added to or removed from the rock. As shown by that in Yinshan deposit, less than 20% of the increment of RE was caused by the "condensed" of leaching some of major elements (e.g. Si, Na) from the rock. The principal factor which should be responsible for the higher contents of RE in altered rock is the addition of RE into the rock by hydrothermal fluids. Eu is selectively leached from the altered sericite phyllite by a mild acidity and reducing fluid which is characterized by much lower LRE/HRE ratio and a large positive Eu anomaly. A major effect on the RE patterns is the tendency to develop relatively flatter chondrite-normalized patterns. The RE characteristics may be used to distinguish between small and large ore bodies at a later stage of exploration.

  15. Alkali and alkaline earth element geochemistry of Los Humeros Caldera, Puebla, Mexico

    Science.gov (United States)

    Verma, Surendra P.

    1984-03-01

    Results of the measurements of alkali (K, Rb and Cs) and alkaline earth (Ba and Sr) elements on seven pre-caldera and twenty post-caldera samples of Los Humeros volcanics (Pliocene to Recent) are described. These data are interpreted in terms of the known solid-liquid partition coefficients. It appears that fractional crystallization is a dominant petrogenetic process and is controlled by the observed modal phases, namely plagioclase, olivine and clinopyroxene (in decreasing importance), and perhaps, in addition, biotite and titanomagnetite in the later stages of the differentiation sequence. The available major element chemistry and mass-balance calculations support these conclusions. Sr and Nd isotopic data further suggest that these magmas were generated in the underlying mantle, fractionated in a shallow-level magma chamber and underwent very insignificant sialic contamination before eruption.

  16. Geochemistry of rare earth elements in a passive treatment system built for acid mine drainage remediation.

    Science.gov (United States)

    Prudêncio, Maria Isabel; Valente, Teresa; Marques, Rosa; Sequeira Braga, Maria Amália; Pamplona, Jorge

    2015-11-01

    Rare earth elements (REE) were used to assess attenuation processes in a passive system for acid mine drainage treatment (Jales, Portugal). Hydrochemical parameters and REE contents in water, soils and sediments were obtained along the treatment system, after summer and winter. A decrease of REE contents in the water resulting from the interaction with limestone after summer occurs; in the wetlands REE are significantly released by the soil particles to the water. After winter, a higher water dynamics favors the AMD treatment effectiveness and performance since REE contents decrease along the system; La and Ce are preferentially sequestered by ochre sludge but released to the water in the wetlands, influencing the REE pattern of the creek water. Thus, REE fractionation occurs in the passive treatment systems and can be used as tracer to follow up and understand the geochemical processes that promote the remediation of AMD.

  17. [Impact of rice agriculture on nitrogen and phosphorus exports in streams in hilly red soil earth region of central subtropics].

    Science.gov (United States)

    Song, Li-Fang; Wang, Yi; Wu, Jin-Shui; Li, Yong; Li, Yu-Yuan; Meng, Cen; Li, Hang; Zhang, Man-Yi

    2014-01-01

    The research selected the Tuojia catchment and Jianshan catchment in Changsha County, Hunan Province, to comparatively study the effects of rice agriculture on the nitrogen and phosphorus concentrations and exports in streams in the typical agricultural catchments of the hilly red soil earth region. The monitoring of 16 months suggested that, there was a moderate stream nutrient pollution in both Tuojia and Jianshan catchments, especially for nitrogen pollution. Comparing the two catchments, the nitrogen and phosphorus concentrations were higher and the water quality was worse in the Tuojia catchment than that in the Jianshan catchment. From the nutrient composition of view, ammonia nitrogen was the main species of total nitrogen in the Tuojia catchment (accounting for 58.5% of total nitrogen), while it was nitrate nitrogen in the Jianshan catchment (accounting for 76. 1% of total nitrogen). The proportion of dissolved phosphorus in total phosphorus was 47. 1% in the Tuojia catchment, higher than the proportion of 37.5% in the Jianshan catchment. From temporal variations of nutrient dynamics of view, concentrations of all forms of nitrogen were higher during January to February and in July, respectively, and total phosphorus and dissolved phosphorus were higher during May to June and during October to December. Since the stream discharge in the catchments concentrated during the rice growing period from April to October, the higher nutrient concentrations during the period suggested potential risks of nitrogen and phosphorus losses. The total nitrogen mass flux was 1.67 kg x (hm2 x month)(-1) and TP was 0.06 kg x (hm2 x month)(-1) in the Tuojia catchment, which were greater than the 0.44 kg x (hm2 x month)(-1) and 0.02 kg x (hm2 x month)(-1) in the Jianshan catchment. Given the similar climate, geomorphology, soil type and cultivation patterns but the different area proportion of rice agriculture between two catchments, results suggested that, under the traditional

  18. Rare earth element geochemistry of groundwater from a deep seated sandstone aquifer, northern Anhui province, China

    Institute of Scientific and Technical Information of China (English)

    Gui Herong; Sun Linhua; Chen Luwang; Chen Song

    2011-01-01

    Deep coal mines in northern Anhui province,China,provide opportunities for tracing the distribution and fractionation of rare earth elements (REEs) in deep seated environments.Major ions,as well as REE concentrations were measured in groundwater from a sandstone aquifer located between -400 and -280 m.Our results indicate that this groundwater consists of Cl·HCO3-Na or Cl·CO3-Na water types with warm temperature (30.1-31.4℃),circumneutral pH (7.27-8.61) and high levels of total dissolved solids (TDS- 1306-2165 mg/L).Concentrations of REEs in groundwater are high as expressed by their Nd concentrations (0.0086-0.018 μg/L).Except for weak heavy REEs (HREE) enrichment relative to light REEs (LREE),the similarity of REE distribution patterns between groundwater and aquifer rock indicate that enrichment of REEs is considered to be controlled by aquifer rock,as well as by their minerals,whereas the fractionation of REEs is controlled by HREE enriched minerals and,to a lesser extent,by inorganic REE complexes.Ce anomalies normalized to Post Archean Average Shale (PAAS) and aquifer rock are weak,which probably reflect the contribution of reduced conditions in combination with pH,rather than a signature of aquifer rock.

  19. Environmental geochemistry reflected by rare earth elements in Bohai Bay (North China) core sediments.

    Science.gov (United States)

    Xu, Ya-Yan; Song, Jin-Ming; Duan, Li-Qin; Li, Xue-Gang; Zhang, Ying; Sun, Pei-Yan

    2010-08-05

    In Bohai Bay sediment, two cores were collected to estimate the source of sediments, and assess the environmental changes. Sequential extractions were carried out in this study. Rare earth elements (REE) were leached out from four labile fractions: Exchangeable (L1), Bound to carbonates (L2), Bound to Fe-Mn oxides (L3), Bound to organic matter (L4), and the remainder was Residual (R5). The percentages of REE in different fractions follow the order: R5 > L3 > L2 > L4 > L1. With heavy REE depletion and no pronounced REE fractionation, NASC-normalized REE patterns of Bohai Bay sediments are quite consistent with that of Haihe River sediment, which is the key river of Bohai Bay. Y/Ho ratios of total contents are all much lower than the average value of continental crust, while Y/Ho ratios of L2 are higher than those of other fractions. Based on the patterns of REE and Y/Ho ratios of samples, sediments of Bohai Bay mainly come from terrigenous matters, which are mainly brought by Haihe River. And REE combined with carbonates may be partly inherited from anthropogenic matter. Moreover, environmental changes exert significant influences on the patterns and fractionations of REE, and they can be deduced from the characteristics of REE. Our results on the patterns and burial fluxes of REE reflect two environmental changes: Bohai Bay has been shifting towards more reducing conditions in the last one hundred years, and there was a large flood in 1939.

  20. A review of noble gas geochemistry in relation to early Earth history

    Science.gov (United States)

    Kurz, M. D.

    1985-01-01

    One of the most fundamental noble gas constraints on early Earth history is derived from isotopic differences in (129)Xe/(130)Xe between various terrestrial materials. The short half life (17 m.y.) of extinct (129I, parent of (129)Xe, means that these differences must have been produced within the first 100 m.y. after terrestrial accretion. The identification of large anomalies in (129)Xe/(130)Xe in mid ocean ridge basalts (MORB), with respect to atmospheric xenon, suggests that the atmosphere and upper mantle have remained separate since that time. This alone is a very strong argument for early catastrophic degassing, which would be consistent with an early fractionation resulting in core formation. However, noble gas isotopic systematics of oceanic basalts show that the mantle cannot necessarily be regarded as a homogeneous system, since there are significant variations in (3)He/(4)He, (40)Ar/(36)Ar, and (129)Xe/(130)Xe. Therefore, the early degassing cannot be considered to have acted on the whole mantle. The specific mechanisms of degassing, in particular the thickness and growth of the early crust, is an important variable in understanding present day noble gas inventories. Another constraint can be obtained from rocks that are thought to be derived from near the lithosphere asthenosphere boundary: ultramafic xenoliths.

  1. The Use of Lead Isotope and Rare Earth Element Geochemistry for Forensic Geographic Provenancing

    Science.gov (United States)

    Carey, A.; Darrah, T.; Harrold, Z.; Prutsman-Pfeiffer, J.; Poreda, R.

    2008-12-01

    Lead isotope and rare earth element composition of modern human bones are analyzed to explore their utility for geographical provenancing. DNA analysis is the standard for identification of individuals. DNA analysis requires a DNA match for comparison. Thus, DNA analysis is of limited use in cases involving unknown remains. Trace elements are incorporated into bones and teeth during biomineralization, recording the characteristics of an individual's geochemical environment. Teeth form during adolescence, recording the geochemical environment of an individual's youth. Bones remodel throughout an individual's lifetime. Bones consist of two types of bone tissue (cortical and trabecular) that remodel at different rates, recording the geochemical environment at the time of biomineralization. Cortical bone tissue, forming the outer surface of bones, is dense, hard tissue that remodels in 25-30 yrs. Conversely, trabecular bone tissue, the inner cavity of bones, is low density, porous and remodels in 2-5 years. Thus, analyzing teeth and both bone tissues allows for the development of a geographical time line capable of tracking immigration patterns through time instead of only an individual's youth. Geochemical isotopic techniques (Sr, O, C, N) have been used for geographical provenancing in physical anthropology. The isotopic values of Sr, C, O, N are predominantly a function of soil compositions in areas where food is grown or water is consumed. Application of these provenancing techniques has become difficult as an individual's diet may reflect the isotopic composition of foods obtained at the local grocer as opposed to local soil compositions. Thus, we explore the use of REEs and Pb isotopes for geographical provenancing. Pb and REEs are likely more reliable indicators of modern geographical location as their composition are high in bio-available sources such as local soils, atmospheric aerosols, and dust as opposed to Sr, C, O, N that are controlled by food and

  2. The estuarine geochemistry of rare earth elements and indium in the Chao Phraya River, Thailand

    Science.gov (United States)

    Nozaki, Yoshiyuki; Lerche, Dorte; Alibo, Dia Sotto; Snidvongs, Anond

    2000-12-01

    A new filtration method using a 0.04 μm hollow fiber filter was applied to the river, estuarine, and coastal waters in the Chao Phraya estuary for geochemical investigation. The filtered waters were analyzed for all the lanthanides, Y and In by using inductively coupled plasma mass spectrometry (ICPMS). The dissolved concentrations of rare earth elements (REEs) are significantly lower than those reported previously for other rivers, presumably because of effective removal of river colloids by the ultra-filtration. The variation of dissolved REEs in the estuary is dependent on the season. The light REEs vary considerably in the low salinity ( S river discharge is low, the REEs show maxima in the mid salinity ( S = 5-12) zone suggesting that dissolved REEs are supplied to the waters by either desorption from suspended loads or remineralization of underlying sediments. The rapid removal of the REEs is also taking place in the turbid-clear water transition zone ( S = 12-15), presumably due to biological uptake associated with blooming of Noctilca occurred at the time of January sampling. In the medium to high discharge season (July and November), the dissolved REE(III)s at S > 3 show almost conservative trends being consistent with some of the previous works. Europium is strongly enriched in the river and estuarine waters compared to the South China Sea waters. Thus, the REE source of the Chao Phraya River must be fractionated and modified in entering to the South China Sea. Dissolved In and Ce in the high salinity ( S = 20-25) zone of the estuary are lower than those of the offshore waters, and therefore, the dissolved flux of the Chao Phraya River cannot account for the higher concentrations of dissolved In and Ce in the surface waters of the South China Sea. The negative Ce anomaly is progressively developed with increasing salinity, being consistent with continued oxidation of Ce(III) to Ce(IV) in the estuary. Fractionation of the light-to-heavy REEs seems to take

  3. Mineralogy and geochemistry of trace and Rare Earth Element from the Manaila massive sulphide deposit (Eastern Carpathians, Romania)

    Science.gov (United States)

    Moldoveanu, S.; Iancu, O. G.; Kasper, H. U.

    2012-04-01

    Keywords: Eastern Carpathians, Mănăila deposit, REE, trace elements, pyrite The present paper deal with the mineralogy and trace elements geochemistry of sulphide deposits from Mănăila mine field located in NE area of Eastern Carpathians Mountains (Romania). The mineralization occurs within metamorphic rocks of Tulgheş terrane, part of Crystalline-Mezozoic zone of the Eastern Carpathians. The metamorphic rocks in Mănăila area consist of felsic metavolcanics rocks with quartzites and quartz-feldspathic rocks as prevailing types. The P-T metamorphic conditions are typical of greenschis facies with biotite and garnet (Mn-Grt) in mineral assemblage. The mineralogical study was performed using reflected light microscope and Scanning Electron Microscopy (SEM) methods. Thus, the both methods show that the main sulphides minerals are represented by pyrite and chalcopyrite, being followed by sphalerite, galena and little amount of Cu sulphosalts (tetrahedrite and bournonite) and also by gangue minerals (quartz and carbonates). Pyrite occurs as large euhedral to subhedral grains in quartz and small rounded inclusion in chalcopyrite. The trace elements analysis was achieved on whole-rock samples and involved the determination of REE, LIL (Rb, Ba, Sr) and HFS (Y, Zr, Hf, U, Th, Nb, Ta) by ICP-MS method. The concentration of LIL and HFS trace elements in mineralized rocks decrease as follows: Ba > Bi > As > Sb > Co > Ga > Ni > Cd. Even if the barium contents in Mănăila ore is high, baritina (BaSO4) was not identified throught the mineralogical analyses carried out so far. The total rare earth element content (REE) of the samples from Mănăila range from 26.84 to 246.46 ppm. Chondrite - normalized REE patterns of the mineralized rocks show that the LREE are enriched in relation to the HREE. Also a positive Ce anomalies and negative Eu anomalies are present. Y/Ho and Zr/Hf ratios are close to the chondritic ratios indicating Charge-and-Radius-Controlled (CHARAC

  4. Microbial Paleontology, Mineralogy and Geochemistry of Modern and Ancient Thermal Spring Deposits and Their Recognition on the Early Earth and Mars"

    Science.gov (United States)

    Farmer, Jack D.

    2004-01-01

    The vision of this project was to improve our understanding of the processes by which microbiological information is captured and preserved in rapidly mineralizing sedimentary environments. Specifically, the research focused on the ways in which microbial mats and biofilms influence the sedimentology, geochemistry and paleontology of modem hydrothermal spring deposits in Yellowstone national Park and their ancient analogs. Toward that goal, we sought to understand how the preservation of fossil biosignatures is affected by 1) taphonomy- the natural degradation processes that affect an organism from the time of its death, until its discovery as a fossil and 2) diagenesis- longer-term, post-depositional processes, including cementation and matrix recrystallization, which collectively affect the mineral matrix that contains fossil biosignature information. Early objectives of this project included the development of observational frameworks (facies models) and methods (highly-integrated, interdisciplinary approaches) that could be used to explore for hydrothermal deposits in ancient terranes on Earth, and eventually on Mars.

  5. The study of major, trace and rare earth elements geochemistry in Shahrestanak Mn deposit, south of Qom: Implications for genesis

    Directory of Open Access Journals (Sweden)

    Mohammad Maanijou

    2015-04-01

    Full Text Available Introduction The Shahrestanak Mn deposit is located in southern Qom province, 12 km southwest of the city of Kahak. Based on geological-structural divisions of Iran, the deposit belongs to central volcanic belt or Urumieh-Dokhtar zone. The Venarch deposit is one the most important known manganese deposits in Iran. The Sharestanak and Venarch deposits are spatially and temporally related to each other, and have similar geology, mineral texture and structure, host rocks, relationships with faults, and depositional environment. So, their magmatism and deposition conditions can be related to each other. Since no systematic study on the Shahrestanak deposit had been performed before discussing its geological and geochemical characteristics, here it is being attempted to study the geology, petrography, geochemistry of major, minor and trace elements, and Rare Earth Elements (REE of ore, to distinguish the depositional environments and genesis of this deposit and to compare REE of ore in this deposit with other deposits. Sampling and method of study Fourteen samples of manganese ore were selected for geochemical study and analyzing of major, minor, trace elements and REE by ICP-AES and ICP-MS and were sent to SGS Co., Toronto. Detection limits for major elements and trace elements are 0.01% and 0.05ppm, respectively. Result and discussion The deposit is characterized by various lithology and stratigraphy units, consist of: 1 Middle to -Upper Eocene volcano-sedimentary rocks, 2 Oligocene lower red conglomerate and sandstone, 3 Oligo-Miocene limestone and marl (Qom Formation, and 4 Eocene and Lower Miocene basic to intermediate dykes. The most abundant minerals of the deposit are braunite, hausmannite, pyrolusite, and manganite. Evidences such as high Mn/Fe (11.33 and Si/Al (4.86 ratios, low contents of trace elements specially Co (11.40 ppm, Ni (24 ppm, Cu (81.85 ppm, and Ce, with high amounts of SiO2, Mn, Fe, Ba, Zn, As and Sr, all represent

  6. Rare earth element geochemistry of Late Devonian reefal carbonates, Canning Basin, Western Australia: confirmation of a seawater REE proxy in ancient limestones

    Science.gov (United States)

    Nothdurft, Luke D.; Webb, Gregory E.; Kamber, Balz S.

    2004-01-01

    Rare earth element and yttrium (REE+Y) concentrations were determined in 49 Late Devonian reefal carbonates from the Lennard Shelf, Canning Basin, Western Australia. Shale-normalized (SN) REE+Y patterns of the Late Devonian samples display features consistent with the geochemistry of well-oxygenated, shallow seawater. A variety of different ancient limestone components, including microbialites, some skeletal carbonates (stromatoporoids), and cements, record seawater-like REE+Y signatures. Contamination associated with phosphate, Fe-oxides and shale was tested quantitatively, and can be discounted as the source of the REE+Y patterns. Co-occurring carbonate components that presumably precipitated from the same seawater have different relative REE concentrations, but consistent REE+Y patterns. Clean Devonian early marine cements ( n = 3) display REE+Y signatures most like that of modern open ocean seawater and the highest Y/Ho ratios (e.g., 59) and greatest light REE (LREE) depletion (average Nd SN/Yb SN = 0.413, SD = 0.076). However, synsedimentary cements have the lowest REE concentrations (e.g., 405 ppb). Non-contaminated Devonian microbialite samples containing a mixture of the calcimicrobe Renalcis and micritic thrombolite aggregates in early marine cement ( n = 11) have the highest relative REE concentrations of tested carbonates (average total REE = 11.3 ppm). Stromatoporoid skeletons, unlike modern corals, algae and molluscs, also contain well-developed, seawater-like REE patterns. Samples from an estuarine fringing reef have very different REE+Y patterns with LREE enrichment (Nd SN/Yb SN > 1), possibly reflecting inclusion of estuarine colloidal material that contained preferentially scavenged LREE from a nearby riverine input source. Hence, Devonian limestones provide a proxy for marine REE geochemistry and allow the differentiation of co-occurring water masses on the ancient Lennard Shelf. Although appropriate partition coefficients for quantification of

  7. Advancing Access, Attribution, and Integration of Earth & Ocean Science Data: Integrated Services of the Marine Geoscience Data System and the Geoinformatics for Geochemistry Program

    Science.gov (United States)

    Lehnert, K. A.; Carbotte, S. M.; Ferrini, V.; Arko, R. A.; Chan, S.; Ryan, W. B.

    2010-12-01

    Development and operation of digital data collections are needed across all areas of the earth and ocean sciences to ensure access and preservation of data sets collected in support of earth and ocean sciences in order to maximize the return on research investments, while enabling verification of research results and contributing to new science initiatives. This is particularly true for data sets that are acquired at high cost, particularly in the marine environment, and that contain irreplaceable observations made of earth’s dynamic properties. The Marine Geoscience Data System (MGDS, www.marine-geo.org) and the Geoinformatics for Geochemistry Program (GfG, www.geoinfogeochem.org) have over the past decade developed, maintained, and operated community-driven data collections that support the preservation, discovery, retrieval, and analysis of a wide range of observational field and analytical data types from the marine and terrestrial environments, among them the PetDB database, the EarthChem data network, the Ridge2000 and MARGINS databases, the Antarctic and Southern Ocean Data System (ASODS), the Global Multi Resolution Topography Synthesis, and the System for Earth Sample Registration (SESAR). MGDS and GfG systems have been developed based on an active understanding of the practices, needs, and concerns of their user communities. They have engaged investigators in the design of the systems, seeking their feedback, and educating the community about responsibilities and benefits of scientific data management and sharing, and worked with funding agencies, editors, publishers, professional societies, and researchers to achieve broad community support, to proactively drive the development of community standards and best practices for data submission, data publication, data documentation, and data archiving, and to advance implementation. In a new formal partnership named IEDA (Integrated Earth Data Applications), the MGDS and GfG will be funded by the US National

  8. Rare earth element distribution and mineralization in Sweden: an application of principal component analysis to FOREGS soil geochemistry

    NARCIS (Netherlands)

    Sadeghi, Martiya; Morris, George A.; Carranza, Emmanuel John M.; Laderberger, Anna; Andersson, Madelen

    2013-01-01

    This paper presents results of statistical analyses and spatial interpretations of distributions of rare earth elements (REEs) in Sweden using the Forum of European Geological Surveys (FOREGS) geochemical database of topsoil, subsoil and stream sediment compositions. Raster maps depicting spatial di

  9. Rare earth element (REE) geochemistry of phosphorites of the Sonrai area of Paleoproterozoic Bijawar basin, Uttar Pradesh, India

    Institute of Scientific and Technical Information of China (English)

    K. F. Khan; Shamim A. Dar; Saif A. Khan

    2012-01-01

    The rare earth element (REE) data from the Paleoproterozoic Bijawar basin,Sonrai phosphorites were used to interpret the depositional conditions of the phosphorites.The post archean Australian shales (PAAS) normalized REE patterns of the Sonrai phosphorites were characterized by negative Ce and positive Eu anomalies.Middle rare earth elements (MREE)-ennchment was a characteristic feature.Phosphorites showing the diagenetic effects on the REE patterns were limited.The observed Eu anomaly was indicative of an anoxic (or sulphate reducing) diagenetic environment of phosphate formation.Mixing of sea water and upwelling during the Paleoproterozoic was responsible for the recording of positive Eu and negative Ce anomalies in the Sonrai phosphorites.

  10. The Toxicological Geochemistry of Dusts, Soils, and Other Earth Materials: Insights From In Vitro Physiologically-based Geochemical Leach Tests

    Science.gov (United States)

    Plumlee, G. S.; Ziegler, T. L.; Lamothe, P.; Meeker, G. P.; Sutley, S.

    2003-12-01

    Exposure to mineral dusts, soils, and other earth materials results in chemical reactions between the materials and different body fluids that include, depending upon the exposure route, lung fluids, gastrointestinal fluids, and perspiration. In vitro physiologically-based geochemical leach tests provide useful insights into these chemical reactions and their potential toxicological implications. We have conducted such leach tests on a variety of earth materials, including asbestos, volcanic ash, dusts from dry lake beds, mine wastes, wastes left from the roasting of mercury ores, mineral processing wastes, coal dusts and coal fly ash, various soils, and complex dusts generated by the World Trade Center collapse. Size-fractionated samples of earth materials that have been well-characterized mineralogically and chemically are reacted at body temperature (37 C) for periods from 2 hours up to multiple days with various proportions of simulated lung, gastric, intestinal, and/or plasma-based fluids. Results indicate that different earth materials may have quite different solubility and dissolution behavior in vivo, depending upon a) the mineralogic makeup of the material, and b) the exposure route. For example, biodurable minerals such as asbestos and volcanic ash particles, whose health effects result because they dissolve very slowly in vivo, bleed off low levels of trace metals into the simulated lung fluids; these include metals such as Fe and Cr that are suspected by health scientists of contributing to the generation of reactive oxygen species and resulting DNA damage in vivo. In contrast, dry lake bed dusts and concrete-rich dusts are highly alkaline and bioreactive, and cause substantial pH increases and other chemical changes in the simulated body fluids. Many of the earth materials tested contain a variety of metals that can be quite soluble (bioaccessible), depending upon the material and the simulated body fluid composition. For example, due to their acidic

  11. The toxicological geochemistry of Earth materials: An overview of processes and the interdisciplinary methods used to understand them

    Science.gov (United States)

    Plumlee, Geoffrey S.; Morman, Suzette A.; Ziegler, Thomas L.

    2006-01-01

    A broad spectrum of earth materials have been linked to, blamed for, and/or debated as sources for disease. In some cases, the links are clear. For example, excessive exposures to mineral dusts have long been recognized for their role in diseases such as: asbestosis, mesothelioma, and lung cancers (asbestos); silicosis and lung cancer (silica dusts); and coal-workers pneumoconiosis (coal dust). Lead poisoning, particularly in toddlers and young children, has been conclusively linked to involuntary ingestion of soils or other materials contaminated with lead-rich paint particles, leaded gasoline combustion byproducts, and some types of lead-rich mine wastes or smelter particulates. Waters with naturally elevated arsenic contents are common in many regions of the globe, and consumption of these waters has been documented as the source of arsenic-related diseases affecting thousands of people in south Asia and other regions. Exposure to dusts or soils containing pathogens has been documented as the cause of regionally common diseases such as valley fever (coccidioidomycosis) and much rarer diseases such as anthrax. Links between many other earth materials and specific diseases, although suspected, are less clear or are debated. For example, it has been suggested that geographic clusters of diseases such as leukemia are related to exposures to waters or atmospheric particulates containing organic or metal contaminants; however, for many clusters the exact causal relationships between disease and environmental exposure are difficult to prove conclusively. Even for many diseases in which the causal relationship is clear, such as in asbestosis and mesothelioma triggered by asbestos exposure, the minimum exposures needed to trigger disease, the influence of genetic factors, and the exact mechanisms of toxicity are still incompletely understood and are the focus of considerable debate within the public health community. Hence, understanding the health effects resulting from

  12. The effects of sulfur amendments on the geochemistry of sulfur, phosphorus and iron in the mangrove plant (Kandelia obovata (S. L.)) rhizosphere.

    Science.gov (United States)

    Jian, Li; Junyi, Yu; Jingchun, Liu; Chongling, Yan; Haoliang, Lu; Spencer, Kate L

    2017-01-30

    P (phosphorus) and Fe (iron) are limiting elements and S (sulfur) is an important element of the biogeochemical cycle in the mangrove environment. To assess the effects of sulfur on the geochemical cycling of Fe and P at the sediment-plant interface, the speciation distributions of Fe, P and S in sediments were examined. The data showed that higher proportions of amorphous Fe, Fe-bound phosphate, chromium reducible sulfur and elemental sulfur were found in the rhizosphere, while more crystalline Fe, exchangeable phosphate and acid-volatile sulfide were determined in the non-rhizosphere. Sulfate application induced an increase in the Ex-P concentration, high P accumulation and high iron plaque deposition in the roots. In conclusion, sulfate applications had a significant influence on the geochemical cycling of Fe and P in the sediments. It significantly curtailed the Fe and P limit to plant growth and enhanced plant resistance to the rugged surroundings in mangrove. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Geochemistry of rare earth elements in cobalt-rich crusts from the Mid-Pacific M seamount

    Institute of Scientific and Technical Information of China (English)

    CUI Yingchun; LIU Jihua; REN Xiangwen; SHI Xuefa

    2009-01-01

    Rare earth elements (REEs) and major elements of 25 cobalt-rich crusts obtained from different depths of Mid-Pacific M seamount were analyzed using inductively coupled plasma-atomic emission spectrometer and gravimetric method. The results showed that they were hydrogenous crusts with average ∑REE content of 2084.69 μg/g and the light REE (LREE)/heavy REE (HREE) ratio of 4.84. The shale-normalized REE patterns showed positive Ce anomalies. The total content of strictly trivalent REEs increased with water depth. The Ce content and LREE/HREE ratios in Fe-Mn crusts above 2000 m were lower than those below 2000 m. The change in REE with water depth could be explained by two processes: adsorptive scavenging by setting matters and behaviors of REE in seawater. However, the Ce abundance took no obvious correlation with water depth reflects the constant Ce flux. The Ce in crusts existed mainly as Ce(IV), implying that the oxidative-enriching process was controlled by kinetic factors.

  14. Rare earth element geochemistry of groundwaters from coal bearing aquifer in Renlou coal mine, northern Anhui Province, China

    Institute of Scientific and Technical Information of China (English)

    SUN Linhua; GUI Herong; CHEN Song

    2011-01-01

    Rare earth element (REE) concentrations of two different types of groundwaters (high SO42- water-SW and high alkaline waterCW) from coal bearing aquifer (-400~-280 m) in Renlou coal mine, northern Anhui Province, China were measured. The results indicated that they had different REE characteristics: the total concentrations of REEs (∑REE) of SW were lower than those of CW in general although they all had heavy REEs enriched relative to light REEs. The dissolved REE inorganic species of SW included Ln3+, LnCO3+, LnSO4+,Ln(CO3)2- and Ln(SO4)2-, whereas the CW are Ln(CO3)2- and LnCO3+ dominant, and the proportions of Ln(CO3)2- increased while other species decreased with pH increasing. Combined with correlation analysis, the enrichment and fractionation of SW (low alkaline water) were considered to be affected by alkaline concentrations via affecting the types and proportons of REE inorganic species. However, the effect of alkaline concentrations to the enrichment and fractionation of REEs of CW (high alkaline water) was less important than total dissolved solids and pH, which reflected the contribution from different rocks they flowed over, different degrees of water-rock interactions and/or REE solid-liquid partition coefficients.

  15. Rare earth element geochemistry of shallow carbonate outcropping strata in Saudi Arabia: Application for depositional environments prediction

    Science.gov (United States)

    Eltom, Hassan A.; Abdullatif, Osman M.; Makkawi, Mohammed H.; Eltoum, Isam-Eldin A.

    2017-03-01

    The interpretation of depositional environments provides important information to understand facies distribution and geometry. The classical approach to interpret depositional environments principally relies on the analysis of lithofacies, biofacies and stratigraphic data, among others. An alternative method, based on geochemical data (chemical element data), is advantageous because it can simply, reproducibly and efficiently interpret and refine the interpretation of the depositional environment of carbonate strata. Here we geochemically analyze and statistically model carbonate samples (n = 156) from seven sections of the Arab-D reservoir outcrop analog of central Saudi Arabia, to determine whether the elemental signatures (major, trace and rare earth elements [REEs]) can be effectively used to predict depositional environments. We find that lithofacies associations of the studied outcrop (peritidal to open marine depositional environments) possess altered REE signatures, and that this trend increases stratigraphically from bottom-to-top, which corresponds to an upward shallowing of depositional environments. The relationship between REEs and major, minor and trace elements indicates that contamination by detrital materials is the principal source of REEs, whereas redox condition, marine and diagenetic processes have minimal impact on the relative distribution of REEs in the lithofacies. In a statistical model (factor analysis and logistic regression), REEs, major and trace elements cluster together and serve as markers to differentiate between peritidal and open marine facies and to differentiate between intertidal and subtidal lithofacies within the peritidal facies. The results indicate that statistical modelling of the elemental composition of carbonate strata can be used as a quantitative method to predict depositional environments and regional paleogeography. The significance of this study lies in offering new assessments of the relationships between

  16. Biogeochemistry: Early phosphorus redigested

    Science.gov (United States)

    Poulton, Simon W.

    2017-02-01

    Atmospheric oxygen was maintained at low levels throughout huge swathes of Earth's early history. Estimates of phosphorus availability through time suggest that scavenging from anoxic, iron-rich oceans stabilized this low-oxygen world.

  17. Sulfide Mineralogy and Geochemistry

    Science.gov (United States)

    Dilles, John

    2007-02-01

    Reviews in Mineralogy and Geochemistry Series, Volume 61 David J. Vaughan, Editor Geochemical Society and Mineralogical Society of America; ISBN 0-939950-73-1 xiii + 714 pp.; 2006; $40. Sulfide minerals as a class represent important minor rock-forming minerals, but they are generally known as the chief sources of many economic metallic ores. In the past two decades, sulfide research has been extended to include important roles in environmental geology of sulfide weathering and resultant acid mine drainage, as well as in geomicrobiology in which bacteria make use of sulfides for metabolic energy sources. In the latter respect, sulfides played an important role in early evolution of life on Earth and in geochemical cycling of elements in the Earth's crust and hydrosphere.

  18. Experimental investigation of the partitioning of phosphorus between metal and silicate phases - Implications for the earth, moon and eucrite parent body

    Science.gov (United States)

    Newsom, H. E.; Drake, M. J.

    1983-01-01

    An experimental study is reported of the partitioning of Phosphorus between solid metal and basaltic silicate liquid as a function of temperature and oxygen fugacity and of the implications for the earth, moon and eucrite parent body (EPB). The relationship established between the partition coefficient and the fugacity is given at 1190 C by log D(P) = -1.12 log fO2 - 15.95 and by log D(P) = -1.53 log fO2 17.73 at 1300 C. The partition coefficient D(P) was determined, and it is found to be consistent with a valence state of 5 for P in the molten silicate. Using the determined coefficient the low P/La ratios of the earth, moon, and eucrites relative to C1 chondrites can be explained. The lowering of the P/La ratio in the eucrites relative to Cl chondrite by a factor of 40 can be explained by partitioning P into 20-25 wt% sulfur-bearing metallic liquid corresponding to 5-25% of the total metal plus silicate system. The low P/La and W/La ratios in the moon may be explained by the partitioning of P and W into metal during formation of a small core by separation of liquid metal from silicate at low degrees of partial melting of the silicates. These observations are consistent with independent formation of the moon and the earth.

  19. Calcium stable isotope geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Gausonne, Nikolaus [Muenster Univ. (Germany). Inst. fuer Mineralogie; Schmitt, Anne-Desiree [Strasbourg Univ. (France). LHyGeS/EOST; Heuser, Alexander [Bonn Univ. (Germany). Steinmann-Inst. fuer Geologie, Mineralogie und Palaeontologie; Wombacher, Frank [Koeln Univ. (Germany). Inst. fuer Geologie und Mineralogie; Dietzel, Martin [Technische Univ. Graz (Austria). Inst. fuer Angewandte Geowissenschaften; Tipper, Edward [Cambridge Univ. (United Kingdom). Dept. of Earth Sciences; Schiller, Martin [Copenhagen Univ. (Denmark). Natural History Museum of Denmark

    2016-08-01

    This book provides an overview of the fundamentals and reference values for Ca stable isotope research, as well as current analytical methodologies including detailed instructions for sample preparation and isotope analysis. As such, it introduces readers to the different fields of application, including low-temperature mineral precipitation and biomineralisation, Earth surface processes and global cycling, high-temperature processes and cosmochemistry, and lastly human studies and biomedical applications. The current state of the art in these major areas is discussed, and open questions and possible future directions are identified. In terms of its depth and coverage, the current work extends and complements the previous reviews of Ca stable isotope geochemistry, addressing the needs of graduate students and advanced researchers who want to familiarize themselves with Ca stable isotope research.

  20. The astysphere and urban geochemistry-a new approach to integrate urban systems into the geoscientific concept of spheres and a challenging concept of modern geochemistry supporting the sustainable development of planet earth.

    Science.gov (United States)

    Norra, Stefan

    2009-07-01

    In 1875, the geoscientist Walter Suess introduced several spheres, such as the lithosphere and the atmosphere to promote a comprehensive understanding of the system earth. Since then, this idea became the dominating concept for the understanding of the distribution of chemical elements in the system earth. Meanwhile, due to the importance of human beings on global element fluxes, the term anthroposphere was introduced. Nevertheless, in face of the ongoing urbanization of the earth, this concept is not any more adequate enough to develop a comprehensive understanding of global element fluxes in and between solid, liquid, and gaseous phases. This article discusses a new concept integrating urbanization into the geoscientific concept of spheres. No geological exogenic force has altered the earth's surface during the last centuries in such an extent as human activity. Humans have altered the morphology and element balances of the earth by establishing agrosystems first and urban systems later. Currently, urban systems happen to become the main regulators for fluxes of many elements on a global scale due to ongoing industrial and economic development and a growing number of inhabitants. Additionally, urban systems are constantly expanding and cover more and more former natural and agricultural areas. For nature, urban systems are new phenomena, which never existed in previous geological eras. The process of the globe's urbanization concurrently is active with the global climate change. In fact, urban systems are a major emitter for climate active gases. Thus, beside the global changes in economy and society, urbanization is an important factor within the global change of nature as is already accepted for climate, ecosystems, and biodiversity. Due to the fact that urbanization has become a global process shaping the earth and that the urban systems are globally cross-linked among each other, a new geoscientific sphere has to be introduced: the astysphere. This sphere

  1. Partitioning of Phosphorus and Molybdenum between the Earth's Mantle and Core and the Conditions of Core Formation

    Science.gov (United States)

    Acuff, K. M.; Danielson, L.; Righter, K.; Lee, C. T.

    2008-01-01

    There are several hypotheses on the specific processes that might have occurred during the formation of the Earth. One hypothesis that has been proposed is that early in the Earth's formation, there was a magma ocean present, and within this body, siderophile elements separated out of the silicate liquid to form the metal core. This study addresses this hypothesis. P and Mo are moderately siderophile elements that are present in both the mantle and the core. The concentrations of P and Mo in silicate vs. metal can be measured and in turn used to determine the temperatures, pressures, oxygen fugacity and melt composition required to achieve the same concentrations as observed in the mantle. The data here include eight experiments examining the partitioning of P and Mo between metallic liquid and silicate liquid. The purpose of the experiments has been to gain a greater understanding of core-mantle separation during the Earth formation process and examines temperature effect on P and Mo, which has not been systematically studied before.

  2. Fluid Inclusion Studies and Geochemistry of Rare Earth Elements of Hydrothermal Fluorites from P?hrenk, Kir?ehir, Central Turkey

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Fluorite mineralization occurs along fractures and cracks of Middle Eocene and Pliocene limestones and marls in the north and northeast of the P?hrenk region (?i?ekdagi, Kirsehir). Tb/Ca ( Tb/La and Y/Ho ratios were obtained from REE contents of fluorites which have revealed that mineralization is of hydrothermal type. Negative Ce anomalies and positive Eu anomalies reflect that hydrothermal solutions once had high oxygen fugacity. Fluid inclusion studies indicate that homogenization temperatures of mineralization varied between 90oC and 200oC, and hydrothermal solutions are composed of NaCl + KCl + MgCl2 + H2O. In addition, salinity measurements show that hydrothermal solutions were mixed with meteoric or rock formation water. Geologic setting, REE geochemistry and fluid inclusion studies suggest that mineralization was deposited from a solution generated by mixing of magmatic and meteoric water under epithermal conditions.

  3. Radioactive geochronometry from the treatise on geochemistry

    CERN Document Server

    Holland, H D

    2011-01-01

    The history of Earth in the Solar System has been unraveled using natural radioactivity. The sources of this radioactivity are the original creation of the elements and the subsequent bombardment of objects, including Earth, in the Solar System by cosmic rays. Both radioactive and radiogenic nuclides are harnessed to arrive at ages of various events and processes on Earth. This collection of chapters from the "Treatise on Geochemistry" displays the range of radioactive geochronometric studies that have been addressed by researchers in various fields of Earth science. These range from the age of Earth and the Solar System to the dating of the history of Earth that assists us in defining the major events in Earth history. In addition, the use of radioactive geochronometry in describing rates of Earth surface processes, including the climate history recorded in ocean sediments and the patterns of circulation of the fluid Earth, has extended the range of utility of radioactive isotopes as chronometric and tracer ...

  4. Prospects for study of tectono-geochemistry

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Focusing on fault tectono-geochemistry, the authors will illustrate four aspects of the fault tectono-geochemistry and its research prospects: (1) the major elements, trace elements and rare earth elements and their differentiation and dissipation sequence; (2)mineral veins, secondary inclusions, sync-deformation fluids and their micro-kinetic analyses; (3) pressure intensity, temperature grads,solution concentration and their coupled correlation system; (4) tectonic stress fields, rheologic physical fields, geochemical fields and digital modeling of parameters. The four aspects are unique in their own systems and related to one another. A unified explanation of spatial and temporal evolution can be obtained in combination with the geodynamics and tectonic chronology.

  5. Earth

    CERN Document Server

    Carter, Jason

    2017-01-01

    This curriculum-based, easy-to-follow book teaches young readers about Earth as one of the eight planets in our solar system in astronomical terms. With accessible text, it provides the fundamental information any student needs to begin their studies in astronomy, such as how Earth spins and revolves around the Sun, why it's uniquely suitable for life, its physical features, atmosphere, biosphere, moon, its past, future, and more. To enhance the learning experience, many of the images come directly from NASA. This straightforward title offers the fundamental information any student needs to sp

  6. Geochemistry of rare earth elements and yttrium in a Ge-poor coal from the Wulantuga ore deposit, Inner Mongolia, North China

    Institute of Scientific and Technical Information of China (English)

    Jingjing Liu; Yaofa Jiang; Panpan Xie; Qingqian Li

    2014-01-01

    This paper reports data of yttrium and rare earth (REY, or REE if Y is considered) in a Ge-poor (the average value of Ge is 0.57μg/g) coal from the Wulantuga ore deposit, middle Inner Mongolia, northern China. The contents of yttrium and rare earth in six coal samples of the Wulantuga ore deposit were detected by inductively coupled plasma mass spectrometry. The content of yttrium and rare earth in the study area varies from 5.88 to 119.19μg/g, with an average of 61.85μg/g, similar to the average value for world coals. The light-REY and heavy-REY enrichments are the two major REY-enrichment types of the Ge-poor coal from the Wulantuga ore deposit, and the top and bottom parts of the coal seam have a higher content of REY than the middle part. The sources of yttrium and rare earth in the Ge-poor coal of Wulantuga may be mainly associated with terrigenous materials and natural waters enriched in yttrium and rare earth.

  7. Phosphorus, Agriculture & The Environment

    OpenAIRE

    Mullins, Gregory Lee

    2009-01-01

    Discusses potential environmental impacts of phosphorus, the functions of phosphorus in plants and animals, and the soil phosphorus cycle. Notes methods for controlling phosphorus losses to surface waters

  8. The Nolans Bore rare-earth element-phosphorus-uranium mineral system: geology, origin and post-depositional modifications

    Science.gov (United States)

    Huston, David L.; Maas, Roland; Cross, Andrew; Hussey, Kelvin J.; Mernagh, Terrence P.; Fraser, Geoff; Champion, David C.

    2016-08-01

    Nolans Bore is a rare-earth element (REE)-U-P fluorapatite vein deposit hosted mostly by the ~1805 Ma Boothby Orthogneiss in the Aileron Province, Northern Territory, Australia. The fluorapatite veins are complex, with two stages: (1) massive to granular fluorapatite with inclusions of REE silicates, phosphates and (fluoro)carbonates, and (2) calcite-allanite with accessory REE-bearing phosphate and (fluoro)carbonate minerals that vein and brecciate the earlier stage. The veins are locally accompanied by narrow skarn-like (garnet-diopside-amphibole) wall rock alteration zones. SHRIMP Th-Pb analyses of allanite yielded an age of 1525 ± 18 Ma, interpreted as the minimum age of mineralisation. The maximum age is provided by a ~1550 Ma SHRIMP U-Pb age for a pegmatite that predates the fluorapatite veins. Other isotopic systems yielded ages from ~1443 to ~345 Ma, implying significant post-depositional isotopic disturbance. Calculation of initial ɛNd and 87Sr/86Sr at 1525 Ma and stable isotope data are consistent with an enriched mantle or lower crust source, although post-depositional disturbance is likely. Processes leading to formation of Nolans Bore began with north-dipping subduction along the south margin of the Aileron Province at 1820-1750 Ma, producing a metasomatised, volatile-rich, lithospheric mantle wedge. About 200 million years later, near the end of the Chewings Orogeny, this reservoir and/or the lower crust sourced alkaline low-degree partial melts which passed into the mid- and upper-crust. Fluids derived from these melts, which may have included phosphatic melts, eventually deposited the Nolans Bore fluorapatite veins due to fluid-rock interaction, cooling, depressurisation and/or fluid mixing. Owing to its size and high concentration of Th (2500 ppm), in situ radiogenic heating caused significant recrystallisation and isotopic resetting. The system finally cooled below 300 °C at ~370 Ma, possibly in response to unroofing during the Alice Springs

  9. Geology and stable isotope geochemistry of Paleoarchean sulfur. Formation, preservation and geobiology of ancient pyrite and barite. (Utrecht Studies in Earth Sciences 031)

    NARCIS (Netherlands)

    Roerdink, D.L.

    2013-01-01

    Sulfur isotopes in ancient sulfate and sulfide minerals provide a comprehensive record of microbial processes involved in the early sulfur cycle on Earth. However, the interpretation of these isotopic signatures requires information on the geological context of such samples, because abiotic reaction

  10. Geochemistry of U and Th and its Influence on the Origin and Evolution of the Crust of Earth and the Biological Evolution

    CERN Document Server

    Bao, Xuezhao

    1998-01-01

    We have investigated the migration behaviors of uranium (U) and thorium (Th) in the Earth and other terrestrial planets. Theoretical models of U and Th migration have been proposed. These models suggest that the unique features of the Earth are closely connected with its unique U and Th migration models and distribution patterns. In the Earth, U and Th can combine with oxidative volatile components and water, migrate up to the asthenosphere position to form an enrichment zone (EZ) of U and Th first, and then migrate up further to the crusts through magmatism and metamorphism. We emphasize that the formation of an EZ of U, Th and other heat-producing elements is a prerequisite for the formation of a plate tectonic system. The heat-producing elements, currently mainly U and Th, in the EZ are also the energy sources that drive the formation and evolution of the crust of Earth and create special granitic continental crusts. In other terrestrial planets, including Mercury, Venus, and Mars, an EZ can not be formed ...

  11. Geochemistry of Platinum Group and Rare Earth Elements of the Polymetallic Layer in the Lower Cambrian,Weng'an,Guizhou Province

    Institute of Scientific and Technical Information of China (English)

    FU Yong; WU Chaodong; GUAN Ping; QU Wenjun; CHEN Jiafu

    2009-01-01

    The black shales of the Lower Cambrian Niutitang Formation in Weng'an.on the Yangtze platform of south China,contain voluminous polymetallic sulfide deposits.A comprehensive geochemical investigation of trace,rare earth,and platinum group elements(PGE)has been undertaken in order to discuss its ore genesis and correlation with the tectono.depositional setting.The ore-bearing layers enrich molybdenum(Mo),nickeI(Ni),vanadium(V),lead(Pb),strontium(Sr), bariam(Ba),uranium(U),arsenic(As),and rare earth elements(REE)in abundance.High uranium/thorium(U/Th)ratios(U/Th>1)indicated that mineralization was mainly influenced by the hydrothermal process.The δU value Was above 1.9.showing a reducing sedimentary condition.The REE patterns showed high enrichment in Iight rare earth elements (LREE)(heavy rare earth elements (HREE)(LREE/HREE=5-17),slightly negative europium(EU)and cerium(Ce)anomalies(δEu=0.81-0.93).and positive Ce anomalies(δCe=0.76-1.12).PGE abundance was characterized by the PGE-type distribution patterns,enriching platinum(Pt),palladium(Pd),ruthenium(RuJ and osmium(Os).The Pt,Pd ratio was 0.8.which is close to the ratios of seawater and ultramafic rocks.AII of these geochemical features suggest that the mineralization was triggered by hydrothermal activity in an extensionai setting in the context of break-up of the Rodinian supercontinent.

  12. Geochemistry of rare-earth elements and its significance in the study of climatic and environmental change in Barrow, Arctic Alaska

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Geochemical characteristics of rare-earth elements (REE) and sedimentary features were studied in the borehole 96-7-1 from Elson Lagoon in Barrow, Arctic Alaska. The results show that total contents of REE (∑ REE) are lower, suggesting that physical weathering is dominate, therefore, concentrations of rare-earth elements are lower in the paleosediment environment. The chondrite-normalized distribution patterns of RE,Es are characterized by light REE (LREE) enrichment and Eu-depletion with the terrestrial sedimentary rock as the parent materials. In comparison with the borecore AB-67 in Elson Lagoon, the main conclusions for climatic and environmental changes are similar: before 1740 A. D. , it was cold and dry with terrestrial properties,but the comparatively warming around 1400 A.D. and 1550 A. D. ; after 1740 A. D. ,it became warming, or markedly after 1821 A.D. ; but it was cold around 1890 A. D.From 1904 A. D. , it got warm again, but it was relatively cold around 1971 A. D..

  13. USGS Energy Geochemistry Database

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Since January of 1989, the U.S Geological Survey (USGS) Energy Resources Program Geochemistry Laboratory Data Base has grown to contain the analytical data for over...

  14. The 8th ICGG International Conference on Gas Geochemistry Preface: Fluids and tectonics

    Directory of Open Access Journals (Sweden)

    F. Italiano

    2007-06-01

    Full Text Available The 8th International Conference on Gas Geochemistry provided the opportunity for scientists from different countries to meet each other, exchange ideas on the state of the art in gas geochemistry, and discuss advance in fluid geochemistry. The 8th ICGG meeting focused on three main geologic environments currently interacting with the human life: volcanoes, earthquakes and hydrocarbons. Ninety-four presentations gave participants chance to cover a variety of important research topics on gas geochemistry in geosciences including: gas migration in terrestrial and marine environments, Earth degassing and its relation to seismicity, volcanic eruptions, rare gases and application of isotope techniques, measurement and analytical techniques.

  15. Anomaly and geochemistry of rare earth elements and yttrium in the late Permian coal from the Moxinpo mine, Chongqing, southwestern China

    Institute of Scientific and Technical Information of China (English)

    Jianhua Zou; Dong Liu; Heming Tian; Tian Li; Feng Liu; Lin Tan

    2014-01-01

    The rare earth elements and yttrium (REY) of the K2 coal from the Moxinpo mine, Chongqing, were deter-mined using inductively coupled plasma mass spectrometry (ICP-MS). The results show that REY are enriched in the K2 coal, with the average content up to 462 lg/g, much higher than average values of most coals in the world. The REY distribution patterns indicate that the light REY is enriched and show a well-pronounced Eu minimum. The fractionation of individual light-REY is higher than that of the heavy-REY. The REY distribution through the K2 coal seam shows that the top and bottom portion of the coal seam have a lower content of REY than the middle portion. Goyazite and rhabdophane were identified with a scanning electron microscope equipped with an energy-dispersed X-ray spectrometer (SEM-EDX). The REY distributions through the coal seam, SEM-EDX data and the correlation analysis between ash yields and the concentrations have revealed that the REY mainly occurs in the organic matter. The K2 coal is a potential rare-metal resource due to its high REY contents, and the coal ash could be regarded as a new and promising raw material for recovery of REY as a by-product.

  16. Evolution of the global phosphorus cycle.

    Science.gov (United States)

    Reinhard, Christopher T; Planavsky, Noah J; Gill, Benjamin C; Ozaki, Kazumi; Robbins, Leslie J; Lyons, Timothy W; Fischer, Woodward W; Wang, Chunjiang; Cole, Devon B; Konhauser, Kurt O

    2017-01-19

    The macronutrient phosphorus is thought to limit primary productivity in the oceans on geological timescales. Although there has been a sustained effort to reconstruct the dynamics of the phosphorus cycle over the past 3.5 billion years, it remains uncertain whether phosphorus limitation persisted throughout Earth's history and therefore whether the phosphorus cycle has consistently modulated biospheric productivity and ocean-atmosphere oxygen levels over time. Here we present a compilation of phosphorus abundances in marine sedimentary rocks spanning the past 3.5 billion years. We find evidence for relatively low authigenic phosphorus burial in shallow marine environments until about 800 to 700 million years ago. Our interpretation of the database leads us to propose that limited marginal phosphorus burial before that time was linked to phosphorus biolimitation, resulting in elemental stoichiometries in primary producers that diverged strongly from the Redfield ratio (the atomic ratio of carbon, nitrogen and phosphorus found in phytoplankton). We place our phosphorus record in a quantitative biogeochemical model framework and find that a combination of enhanced phosphorus scavenging in anoxic, iron-rich oceans and a nutrient-based bistability in atmospheric oxygen levels could have resulted in a stable low-oxygen world. The combination of these factors may explain the protracted oxygenation of Earth's surface over the last 3.5 billion years of Earth history. However, our analysis also suggests that a fundamental shift in the phosphorus cycle may have occurred during the late Proterozoic eon (between 800 and 635 million years ago), coincident with a previously inferred shift in marine redox states, severe perturbations to Earth's climate system, and the emergence of animals.

  17. Geochemistry of rare earth elements in the Baba Ali magnetite skarn deposit, western Iran – a key to determine conditions of mineralisation

    Directory of Open Access Journals (Sweden)

    Zamanian Hassan

    2016-03-01

    Full Text Available The Baba Ali skarn deposit, situated 39 km to the northwest of Hamadan (Iran, is the result of a syenitic pluton that intruded and metamorphosed the diorite host rock. Rare earth element (REE values in the quartz syenite and diorite range between 35.4 and 560 ppm. Although the distribution pattern of REEs is more and less flat and smooth, light REEs (LREEs in general show higher concentrations than heavy REEs (HREEs in different lithounits. The skarn zone reveals the highest REE-enriched pattern, while the ore zone shows the maximum depletion pattern. A comparison of the concentration variations of LREEs (La–Nd, middle REEs (MREEs; Sm–Ho and HREEs (Er–Lu of the ore zone samples to the other zones elucidates two important points for the distribution of REEs: 1 the distribution patterns of LREEs and MREEs show a distinct depletion in the ore zone while representing a great enrichment in the skarn facies neighbouring the ore body border and decreasing towards the altered diorite host rock; 2 HREEs show the same pattern, but in the exoskarn do not reveal any distinct increase as observed for LREEs and MREEs. The ratio of La/Y in the Baba Ali skarn ranges from 0.37 to 2.89. The ore zone has the highest La/Y ratio. In this regard the skarn zones exhibit two distinctive portions: 1 one that has La/Y >1 beingadjacent to the ore body and; 2 another one with La/Y < 1 neighbouring altered diorite. Accordingly, the Baba Ali profile, from the quartz syenite to the middle part of the exoskarn, demonstrates chiefly alkaline conditions of formation, with a gradual change to acidic towards the altered diorite host rocks. Utilising three parameters, Ce/Ce*, Eu/Eu* and (Pr/Ybn, in different minerals implies that the hydrothermal fluids responsible for epidote and garnet were mostly of magmatic origin and for magnetite, actinolite and phlogopite these were of magmatic origin with low REE concentration or meteoric water involved.

  18. The rare earth element geochemistry of acid-sulphate and acid-sulphate-chloride geothermal systems from Yellowstone National Park, Wyoming, USA

    Science.gov (United States)

    Lewis, Anita J.; Palmer, Martin R.; Sturchio, Neil C.; Kemp, Anthony J.

    1997-02-01

    Rare earth element (REE) concentrations have been determined by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) in acid-sulphate and acid-sulphate-chloride waters and the associated sinters and volcanic rocks from the Yellowstone National Park (YNP), Wyoming, USA, geothermal system. REE concentrations in the volcanic rocks range from 222 to 347 ppm; their chondite-normalised REE patterns are typical of upper continental crust, with LREE > HREE and negative Eu anomalies. Total REE concentrations in the fluids range from 3 to 1133 nmol kg -1 (≥ 162 ppm), and ΣREE concentrations in sinter are ≥ 181 ppm. REE abundances and patterns in drill core material from YNP indicate some REE mobility. Normalisation of REE concentrations in altered Lava Creek Tuff (LCT) from Y-12 drill core to REE concentrations in fresh LCT indicate that the REE overall have been depleted with the exception of Eu, which has been decoupled from the REE series and concentrated in the altered rocks. Relative to the host rocks the REE patterns of the fluids are variably depleted in HREEs and LREEs, and usually have a pronounced positive Eu anomaly. This decoupling of Eu from the REE suite suggests that (1) Eu has been preferentially removed either from the host rock glass or from the host rock minerals, or (2) the waters are from a high temperature or reducing environment where Eu 2+ is more soluble than the trivalent REEs. Since the latter is inconsistent with production of acid-sulphate springs in a low temperature, oxidising near-surface environment, we suggest that the positive Eu anomalies in the fluids result from preferential dissolution of a Eu-rich phase in the host rock. Spatial and temporal variations in major element chemistry and pH of the springs sampled from Norris Geyser Basin and Crater Hills accompany variations in REE concentrations and patterns of individual geothermal springs. These are possibly related to changes in subsurface plumbing, which results in variations in

  19. Direct evidence for the availability of reactive, water soluble phosphorus on the early Earth. H-phosphinic acid from the Nantan meteorite.

    Science.gov (United States)

    Bryant, David E; Kee, Terence P

    2006-06-14

    Anoxic irradiation of a type IIICD iron meteorite known to contain the phosphide mineral schreibersite (Fe,Ni)3P in the presence of ethanol/water affords the reactive oxyacid H-phosphinic acid (H3PO2) as the dominant phosphorus product.

  20. Rapakivi granites in the geological history of the earth. Part 1, magmatic associations with rapakivi granites: Age, geochemistry, and tectonic setting

    Science.gov (United States)

    Larin, A. M.

    2009-06-01

    peripheral orogens whose evolution lasted from ˜1.9 to 1.0 Ga. Magmatism of this kind was most active 1.8-1.3 Ga ago and represented the distal effect of subduction or collisional events along the convergent boundaries of lithospheric plates. An important factor that favored the emplacement of rapakivi granites and anorthosites in a huge volume was the thermal and rheologic state of the lithosphere inherited from antedating orogenic events, first of all from the event ˜1.9 Ga ago, which was unique in terms of heat capacity transferred into the lithosphere. Anorthosite-mangerite-rapakivi granite-peralkaline granite magmatism is connected with activity of the mantle plums only. Degradation of the rapakivi granite magmatism toward the terminal Proterozoic was controlled by the general cooling of the Earth in the course of the steady dissipation of its endogenic energy, as these processes became accelerated since the Late Riphean

  1. The Marine Geochemistry of Rhenium, Iridium and Platinum

    Science.gov (United States)

    1991-09-01

    in the boundary clay, and proposed that this was the result of the impact of a 10 km meteorite with the Earth (Alvarez et al. 1980). Subsequently, Ir...Esser, B. K. (1991). Osmium Isotope Geochemistry of Terrigenous and Marine Sediments. PhD thesis, Yale University. Felitsyn, S. B. and P. A. Vaganov...C. E. (1990). Rhenium- Osmium Isotope Geochemistry of the Mantle, PhD Thesis, Yale University. McCallum, M. E., R. R. Loucks, R. R. Carlson, E. F

  2. Prebiotic phosphorus chemistry reconsidered

    Science.gov (United States)

    Schwartz, A. W.; Orgel, L. E. (Principal Investigator)

    1997-01-01

    The available evidence indicates that the origin of life on Earth certainly occurred earlier than 3.5 billion years ago and perhaps substantially earlier. The time available for the chemical evolution which must have preceded this event is more difficult to estimate. Both endogenic and exogenic contributions to chemical evolution have been considered; i.e., from chemical reactions in a primitive atmosphere, or by introduction in the interiors of comets and/or meteorites. It is argued, however, that the phosphorus chemistry of Earth's earliest hydrosphere, whether primarily exogenic or endogenic in origin, was most likely dominated by compounds less oxidized than phosphoric acid and its esters. A scenario is presented for the early production of a suite of reactive phosphonic acid derivatives, the properties of which may have foreshadowed the later appearance of biophosphates.

  3. Phosphorus Cycling Through Space and Time

    Science.gov (United States)

    Filippelli, Gabriel

    2014-05-01

    The cycling of phosphorus, a biocritical element in short supply in nature, is an important Earth system process. Variations in the phosphorus cycle have occurred in the past. For example, the rapid uplift of the Himalayan-Tibet Plateau increased chemical weathering, which led to enhanced input of phosphorus to the oceans. This drove the late Miocene "biogenic bloom." On glacial timescales, phosphorus is quite dynamic. In terrestrial systems, phosphorus soil mineralogy alters rapidly in response to early soil development, and ultimately becomes limited to plant availability in many setting. In marine systems, the loss of the substantial continental margin sink for reactive P occurs during glacial sea-level lowstands, effectively concentrating phosphorus in the deep sea. Finally, in the modern, the phosphorus cycle is dominated by human activity and agriculture, which causes unwanted pollution due to high phosphorus loading and itself poses significant concerns about the ultimate future availability of this nutrient to feed an expanding human population. This presentation will cover several critical components of the phosphorus cycle, including terrestrial and marine systems, through the lens of geologic time. This perspective reveals the significant changes that have occurred in the availability of phosphorus through time, and how other biogeochemical systems have responded to these changes. Furthermore, the perspective provides some sobering insights into the mechanisms behind the concentration of marine phosphorus into viable sources of phosphate rock. The rarity of high-quality phosphate rock deposits and the limitation of easily minable reserves are becoming critical, as the human demand for fertilizer phosphorus far outstrips the geologic rate of replacement and few prospects exist for new discoveries of phosphate rock.

  4. Evolution of the global phosphorus cycle

    Science.gov (United States)

    Reinhard, Christopher T.; Planavsky, Noah J.; Gill, Benjamin C.; Ozaki, Kazumi; Robbins, Leslie J.; Lyons, Timothy W.; Fischer, Woodward W.; Wang, Chunjiang; Cole, Devon B.; Konhauser, Kurt O.

    2016-12-01

    The macronutrient phosphorus is thought to limit primary productivity in the oceans on geological timescales. Although there has been a sustained effort to reconstruct the dynamics of the phosphorus cycle over the past 3.5 billion years, it remains uncertain whether phosphorus limitation persisted throughout Earth’s history and therefore whether the phosphorus cycle has consistently modulated biospheric productivity and ocean–atmosphere oxygen levels over time. Here we present a compilation of phosphorus abundances in marine sedimentary rocks spanning the past 3.5 billion years. We find evidence for relatively low authigenic phosphorus burial in shallow marine environments until about 800 to 700 million years ago. Our interpretation of the database leads us to propose that limited marginal phosphorus burial before that time was linked to phosphorus biolimitation, resulting in elemental stoichiometries in primary producers that diverged strongly from the Redfield ratio (the atomic ratio of carbon, nitrogen and phosphorus found in phytoplankton). We place our phosphorus record in a quantitative biogeochemical model framework and find that a combination of enhanced phosphorus scavenging in anoxic, iron-rich oceans and a nutrient-based bistability in atmospheric oxygen levels could have resulted in a stable low-oxygen world. The combination of these factors may explain the protracted oxygenation of Earth’s surface over the last 3.5 billion years of Earth history. However, our analysis also suggests that a fundamental shift in the phosphorus cycle may have occurred during the late Proterozoic eon (between 800 and 635 million years ago), coincident with a previously inferred shift in marine redox states, severe perturbations to Earth’s climate system, and the emergence of animals.

  5. Phosphorus speciation by coupled HPLC-ICPMS: low level determination of reduced phosphorus in natural materials

    Science.gov (United States)

    Atlas, Zachary; Pasek, Matthew; Sampson, Jacqueline

    2015-04-01

    Phosphorus is a geologically important minor element in the Earth's crust commonly found as relatively insoluble apatite. This constraint causes phosphorus to be a key limiting nutrient in biologic processes. Despite this, phosphorus plays a direct role in the formation of DNA, RNA and other cellular materials. Recent works suggest that since reduced phosphorus is considerably more soluble than oxidized phosphorus that it was integrally involved in the development of life on the early Earth and may continue to play a role in biologic productivity to this day. This work examines a new method for quantification and identification of reduced phosphorus as well as applications to the speciation of organo-phosphates separated by coupled HPLC - ICP-MS. We show that reduced phosphorus species (P1+, P3+ and P5+) are cleanly separated in the HPLC and coupled with the ICPMS reaction cell, using oxygen as a reaction gas to effectively convert elemental P to P-O. Analysis at M/Z= 47 producing lower background and flatter baseline chromatography than analyses performed at M/Z = 31. Results suggest very low detection limits (0.05 μM) for P species analyzed as P-O. Additionally we show that this technique has potential to speciate at least 5 other forms of phosphorus compounds. We verified the efficacy of method on numerous materials including leached Archean rocks, suburban retention pond waters, blood and urine samples and most samples show small but detectible levels of reduced phosphorus and or organo-phaospates. This finding in nearly all substances analyzed supports the assumption that the redox processing of phosphorus has played a significant role throughout the history of the Earth and it's presence in the present environment is nearly ubiquitous with the reduced oxidation state phosphorus compounds, phosphite and hypophosphite, potentially acting as significant constituents in the anaerobic environment.

  6. 内蒙古阿刀亥矿晚古生代煤的微量元素和稀土元素地球化学特征%Geochemistry of trace and rare earth elements in the Late Paleozoic Coal from Adaohai Mine, Inner Mongolia

    Institute of Scientific and Technical Information of China (English)

    邹建华; 刘东; 田和明; 刘峰; 李甜; 杨洪永

    2013-01-01

    The trace and rare earth element geochemistry of coal in Adaohai mine were studied using the methods of inductively coupled plasma mass spectrometry,X-ray fluorescence and proximate analysis.On the basis of the contents and ratios of some elements,the peat-accumulating environment of studying area was discussed.The results show that elements including Cl,Sc,Ge,Se,Zr,Mo,Cd,In,Sb,Te,Hf,Hg,Pb,Bi and REE are enriched,compared with the average content of Chinese upper crust.The rare earth element patterns indicate that the light rare earth element is enriched while the heavy rare earth element is deficit and show a clear Eu negative anomaly.The fractionation of light rare earth element is high,and that of the heavy rare earth element is low.The occurrence of rare earth element is probably related to clay minerals.The ratios of δEu,Sr/Ba,V/(V+Ni),V/Ni,Ni/Co and S illustrate that the peat-accumulating environment of Adaohai is in-lake fresh water,intermittenly affected by sea water.%利用电感耦合等离子体质谱(ICP-MS)、X射线荧光光谱(XRF)、工业分析等方法对内蒙古阿刀亥矿煤的微量元素和稀土元素地球化学特征进行了研究,并根据某些微量元素的含量及比值探讨了研究区的成煤环境.研究发现,与中国上陆壳相比阿刀亥矿煤中比较富集Cl,Sc,Ge,Se,Zr,Mo,Cd,In,Sb,Te,Hf,Hg,Pb,Bi和REE.稀土元素分布模式表明LREE明显富集,HREE相对亏损,Eu负异常明显,且轻稀土元素之间的分馏程度较高,重稀土元素之间的分馏程度较低,稀土元素可能主要赋存于黏土矿物中.δEu,Sr/Ba,V/(V+Ni),V/Ni,Ni/Co值及S的含量总体上反映出阿刀亥矿泥炭的沉积环境为内陆淡水还原环境,间或受到海水的影响.

  7. Dietary phosphorus, serum phosphorus, and cardiovascular disease.

    Science.gov (United States)

    Menon, Madhav C; Ix, Joachim H

    2013-10-01

    Recent epidemiologic studies have linked higher serum phosphorus concentrations to cardiovascular disease (CVD) events and mortality. This association has been identified in the general population and in those with chronic kidney disease (CKD). The risk of adverse outcomes appears to begin with phosphorus concentrations within the upper limit of the normal reference range. Multiple experimental studies have suggested pathogenetic mechanisms that involve direct and indirect effects of high phosphorus concentrations to explain these associations. Drawing from these observations, guideline-forming agencies have recommended that serum phosphorus concentrations be maintained within the normal reference range in patients with CKD and that dietary phosphorus restriction or use of intestinal phosphate binders should be considered to achieve this goal. However, outside the dialysis population, the links between dietary phosphorus intake and serum phosphorus concentrations, and dietary phosphorus intake and CVD events, are uncertain. With specific reference to the nondialysis populations, this review discusses the available data linking dietary phosphorus intake with serum phosphorus concentrations and CVD events.

  8. Earth Abides Arsenic Biotransformations

    OpenAIRE

    Zhu, Yong-Guan; Yoshinaga, Masafumi; Zhao, Fang-Jie; Rosen, Barry P.

    2014-01-01

    Arsenic is the most prevalent environmental toxic element and causes health problems throughout the world. The toxicity, mobility, and fate of arsenic in the environment are largely determined by its speciation, and arsenic speciation changes are driven, at least to some extent, by biological processes. In this article, biotransformation of arsenic is reviewed from the perspective of the formation of Earth and the evolution of life, and the connection between arsenic geochemistry and biology ...

  9. Phosphorus recycling from an unexplored source by polyphosphate accumulating microalgae and cyanobacteria – a step to phosphorus security in agriculture

    Directory of Open Access Journals (Sweden)

    Chandan eMukherjee

    2015-12-01

    Full Text Available Phosphorus (P, an essential element required for crop growth has no substitute. The global food security depends on phosphorus availability in soil for crop production. World phosphorus reserves are fast depleting and with an annual increase of 2.3% in phosphorus demand, the current reserves will be exhausted in coming 50-100 years. India and other Western countries are forced to import phosphorus fertilizers at high costs to meet their agricultural demands due to uneven distribution of phosphate rocks on earth. The present study from India, aims to draw attention to an unnoticed source of phosphorus being wasted as parboiled rice mill effluent and subsequent bio-recovery of the valuable element from this unconventional source. The research was conducted in West Bengal, India, a state with the highest number of parboiled rice mills where its effluent carries on an average ~40 mg/L of soluble phosphorus. Technology to recover and recycle this wastewater P in India in a simple, inexpensive mode is yet to be optimized. Our strategy to use microalgae, Chlorella sp. and cyanobacteria, Cyanobacterium sp., Lyngbya sp. and Anabaena sp. to sequester the excess phosphorus from the effluent as polyphosphate inclusions and its subsequent recycling as slow and moderate release phosphorus biofertilizers to aid plant growth, preventing phosphorus loss and pollution, is a contemporary venture to meet the need of the hour. These polyphosphate accumulating microorganisms play a dual role of remediation and recovery of phosphorus, preliminarily validated in laboratory scale.

  10. Geochemistry between search for raw materials and environmental protection

    Energy Technology Data Exchange (ETDEWEB)

    Hunziker, J.C. [Lausanne Institut de Mineralogie, Lausanne (Switzerland)

    2000-07-01

    Geochemistry is a speciality of earth sciences regarding distribution and movement of chemical elements throughout the planetary system. Known for about 170 years, the term geochemistry has been proposed as science per se by the Swedish chemist Joern Jakob Berzelius and in 1838 Christian Friederich Schoenbein, professor for chemistry in Basel, has introduced the term for this science between chemistry, physics and mineralogy. The advances, mainly in analytical means, with the different spectrographs and spectrometers, starting in the early twenties of this century, have triggered the geochemical knowledge of the planet. In this context it has to be mentioned the famous geochemist Victor Moritz Goldschmidt, who considerably contributed to the basic knowledge of this science.

  11. Iron geochemistry of the mantle

    Science.gov (United States)

    Humayun, M.; Campbell, T. J.; Brandon, A. D.; Davis, F. A.; Hirschmann, M. M.

    2011-12-01

    The Fe/Mg ratio is an important constraint on the compositionally controlled density of the mantle. However, this ratio cannot be inferred from erupted lavas from OIB or MORB sources, but must be determined directly from mantle peridotites. Recently, the Fe/Mn ratio of erupted lavas has been used as an indicator of potential Fe variability in the mantle driven by core-mantle interaction, recycled oceanic crust, or even variations in the temperature of mantle melting. The classic compilation of McDonough & Sun (1995) provided the currently accepted Fe/Mn ratio of the upper mantle, 60±10. The uncertainty on this ratio allows for 15-30% variability in mantle iron abundances, which is equivalent to a density variation larger than observed by seismic tomography in the mantle. To better understand the relationship between mantle peridotites and erupted lavas, and to search for real variability in the Fe/Mn ratio of mantle peridotites, we report precise new ICP-MS measurements of the transition element geochemistry of suites of mantle xenoliths that have known Fe/Mg ratios. For 12 Kilbourne Hole xenoliths, we observe a clear correlation between Fe/Mn and MgO (or Fe/Mg) over an Fe/Mn range of 59-72. Extrapolation of this trend to a Primitive Mantle (PM) MgO content of 37.8 yields an Fe/Mn of 59±1 for the PM. Our new analyses of KLB-1 powder and fused glass beads yield an Fe/Mn of 61.4 for both samples, which plots on the Kilbourne Hole Fe/Mn vs. MgO trend. A set of ten xenoliths from San Carlos yield a wide range of Fe/Mn (56-65) not correlated with MgO content. The San Carlos xenoliths may have experienced a metasomatic effect that imprinted variable Fe/Mn. A clinopyroxene-rich lithology from San Carlos yields an Fe/Mn of 38, which plots on an extension of the Kilbourne Hole Fe/Mn vs. MgO trend. These new results, and those from other xenolith localities being measured in our lab, provide new constraints on the compositional variability of the Earth's upper mantle. Mc

  12. Alteration geochemistry of the volcanic-hosted Dedeninyurdu, Yergen and Fındıklıyar Cu-Fe mineralization, Northern part of Gökçedoǧan Village, Çorum-Kargi Region, Turkey: Implications for the rare earth elements geochemical characteristics

    Science.gov (United States)

    Ozturk, Sercan; Gumus, Lokman; Abdelnasser, Amr; Yalçin, Cihan; Kumral, Mustafa; Hanilçi, Nurullah

    2016-04-01

    This study deals with the rare earth element (REE) geochemical behavior the alteration zonesassociated with the volcanic-hosted Cu-Femineralization at the northern part of Gökçedoǧan village, Çorum-Kargi region (N Turkey) which are Dedeninyurdu, Yergen and Fındıklıyar mineralization. The study areacomprises Bekirli Formation, Saraycık Formation, Beşpınar Formation, and Ilgaz Formation. Saraycık Formation consists ofUpper Cretaceous KargıOphiolites, pelagic limestone, siltstone, chert and spilitic volcanic rocks. Fe-Cu mineralization occurred in the spiliticvolcanic rocks of Saraycık Formation representing the host rockand is related with the silicification and sericitizationalteration zones. Dedeninyurdu and Yergen mineralization zone directed nearly N75-80oEis following structural a line but Fındıklıyar mineralization zone has nearly NW direction. The ore mineralogy in these zonesinclude pyrite, chalcopyrite, covellite, hematite with malachite, goethite and a limonite as a result of oxidation. The geochemical characteristics of REE of the least altered spiliticbasalt show flat light and heavy REE with slight positive Eu- and Sr-anomalies according to their chondrite-, N-type MORB, and primitive mantle-normalized REE patterns. While the REE geochemical features of the altered rocks collected from the different alteration zones show that there are negative Eu and Sr anomalies as a result of leaching during the alteration processes.There are positive and negative correlations between K2O index with LREE and HREE, respectively. This is due to the additions of K and La during the alteration processes referring to the pervasive sericitization alteration is the responsible for the Cu-Fe mineralization at the study area. Keywords: Cu-Fe mineralization, Spilitic volcanic rocks, alteration, Rare earth elements (REE) geochemistry.

  13. Medical geochemistry of tropical environments

    Science.gov (United States)

    Dissanayake, C. B.; Chandrajith, Rohana

    1999-10-01

    Geochemically, tropical environments are unique. This uniqueness stems from the fact that these terrains are continuously subjected to extreme rainfall and drought with resulting strong geochemical fractionation of elements. This characteristic geochemical partitioning results in either severe depletion of elements or accumulation to toxic levels. In both these situations, the effect on plant, animal and human health is marked. Medical geochemistry involves the study of the relationships between the geochemistry of the environment in which we live and the health of the population living in this particular domain. Interestingly, the relationships between geochemistry and health are most marked in the tropical countries, which coincidentally are among the poorest in the world. The very heavy dependence on the immediate environment for sustainable living in these lands enables the medical geochemist to observe correlations between particular geochemical provinces and the incidence of certain diseases unique to these terrains. The aetiology of diseases such as dental and skeletal fluorosis, iodine deficiency disorders, diseases of humans and animals caused by mineral imbalances among others, lie clearly in the geochemical environment. The study of the chemistry of the soils, water and stream sediments in relation to the incidence of geographically distributed diseases in the tropics has not only opened up new frontiers in multidisciplinary research, but has offered new challenges to the medical profession to seriously focus attention on the emerging field of medical geochemistry with the collaboration of geochemists and epidemiologists.

  14. Origin of the Moon new concept geochemistry and dynamics

    CERN Document Server

    Galimov, Erik M

    2012-01-01

    The origin of the Moon remains an unsolved problem of the planetary science. Researchers engaged in celestial dynamics, geophysics, and geochemistry are still discussing various models of creation of our closest cosmic neighbour. The most popular scenario, the impact hypothesis involving a collision early in the Earth's history, has been substantially challenged by the new data. The birth and development of a planet-moon system always play a role in the formation of an entire planetary system around our Sun or around another star. This way, the story of our Moon acquires broader ramifications

  15. Glacial atmospheric phosphorus deposition

    Science.gov (United States)

    Kjær, Helle Astrid; Dallmayr, Remi; Gabrieli, Jacopo; Goto-Azuma, Kumiko; Hirabayashi, Motohiro; Svensson, Anders; Vallelonga, Paul

    2016-04-01

    Phosphorus in the atmosphere is poorly studied and thus not much is known about atmospheric phosphorus and phosphate transport and deposition changes over time, though it is well known that phosphorus can be a source of long-range nutrient transport, e.g. Saharan dust transported to the tropical forests of Brazil. In glacial times it has been speculated that transport of phosphorus from exposed shelves would increase the ocean productivity by wash out. However whether the exposed shelf would also increase the atmospheric load to more remote places has not been investigated. Polar ice cores offer a unique opportunity to study the atmospheric transport of aerosols on various timescales, from glacial-interglacial periods to recent anthropogenic influences. We have for the first time determined the atmospheric transport of phosphorus to the Arctic by means of ice core analysis. Both total and dissolved reactive phosphorus were measured to investigate current and past atmospheric transport of phosphorus to the Arctic. Results show that glacial cold stadials had increased atmospheric total phosphorus mass loads of 70 times higher than in the past century, while DRP was only increased by a factor of 14. In the recent period we find evidence of a phosphorus increase over the past 50 yrs in ice cores close to human occupation likely correlated to forest fires. References: Kjær, Helle Astrid, et al. "Continuous flow analysis method for determination of dissolved reactive phosphorus in ice cores." Environmental science & technology 47.21 (2013): 12325-12332. Kjær, Helle Astrid, et al. "Greenland ice cores constrain glacial atmospheric fluxes of phosphorus." Journal of Geophysical Research: Atmospheres120.20 (2015).

  16. Trace- and rare-earth element geochemistry and Pb-Pb dating of black shales and intercalated Ni-Mo-PGE-Au sulfide ores in Lower Cambrian strata, Yangtze Platform, South China

    Science.gov (United States)

    Jiang, Shao-Yong; Chen, Yong-Quan; Ling, Hong-Fei; Yang, Jing-Hong; Feng, Hong-Zhen; Ni, Pei

    2006-08-01

    The Lower Cambrian black shale sequence of the Niutitang Formation in the Yangtze Platform, South China, hosts an extreme metal-enriched sulfide ore bed that shows >10,000 times enrichment in Mo, Ni, Se, Re, Os, As, Hg, and Sb and >1,000 times enrichment in Ag, Au, Pt, and Pd, when compared to average upper continental crust. We report in this paper trace- and rare-earth-element concentrations and Pb-Pb isotope dating for the Ni-Mo-PGE-Au sulfide ores and their host black shales. Both the sulfide ores and their host black shales show similar trace-element distribution patterns with pronounced depletion in Th, Nb, Hf, Zr, and Ti, and extreme enrichment in U, Ni, Mo, and V compared to average upper crust. The high-field-strength elements, such as Zr, Hf, Nb, Ta, Sc, Th, rare-earth elements, Rb, and Ga, show significant inter-element correlations and may have been derived mainly from terrigenous sources. The redox sensitive elements, such as V, Ni, Mo, U, and Mn; base metals, such as Cu, Zn, and Pb; and Sr and Ba may have been derived from mixing of seawater and venting hydrothermal sources. The chondrite-normalized REE patterns, positive Eu and Y anomalies, and high Y/Ho ratios for the Ni-Mo-PGE-Au sulfide ores are also suggestive for their submarine hydrothermal-exhalative origin. A stepwise acid-leaching Pb-Pb isotope analytical technique has been employed for the Niutitang black shales and the Ni-Mo-PGE-Au sulfide ores, and two Pb-Pb isochron ages have been obtained for the black shales (531±24 Ma) and for the Ni-Mo-PGE-Au sulfide ores (521±54 Ma), respectively, which are identical and overlap within uncertainty, and are in good agreement with previously obtained ages for presumed age-equivalent strata.

  17. Reservoir geochemistry; Geoquimica de reservatorios

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Joelma Pimentel; Rangel, Mario Duncan; Morais, Erica Tavares de [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)], Emails: joelma.lopes@petrobras.com.br, mduncan@petrobras.com.br, ericat@petrobras.com.br; Aguiar, Helen G.M. de [Fundacao GORCEIX, Ouro Preto, MG (Brazil)], E-mail: helenaguiar.GORCEIX@petrobras.com.br

    2008-03-15

    Reservoir Geochemistry has many important practical applications during petroleum exploration, appraisal and development of oil fields. The most important uses are related to providing or disproving connectivity between reservoirs of a particular well or horizon. During exploration, reservoir geochemistry can indicate the direction of oil filling, suggesting the most appropriate places for drilling new wells. During production, studies of variations in composition with time and determination of proportions of commingled production from multiple zones, may also be carried out. The chemical constituents of petroleum in natural reservoirs frequently show measurable compositional variations, laterally and vertically. Due to the physical and chemical nature of petroleum changes with increasing maturity (or contribution of a second source during the filling process), lateral and vertical compositional variations exist in petroleum columns as reservoir filling is complete. Compositional variation can also be introduced by biodegradation or water washing. Once the reservoir is filled, density driven mixing and molecular diffusion tend to eliminate inherited compositional variations in an attempt to establish mechanical and chemical equilibrium in the petroleum column (England, 1990). Based on organic geochemical analysis it is possible to define these compositional variations among reservoirs, and use these data for developing of petroleum fields and for reservoir appraisal. Reservoir geochemistry offers rapid and low cost evaluation tools to aid in understanding development and production problems. Moreover, the applied methodology is relatively simple and gives reliable results, and can be performed routinely in any good geochemical laboratory at a relatively low cost. (author)

  18. Phosphorus recovery from wastes

    Science.gov (United States)

    Phosphorus (P) is an important macro-nutrient essential for all living organisms and phosphate rock is the main raw material for all inorganic P fertilizers. It is expected that there will be a P peak and resulting P fertilizer shortage in near future. In general, phosphorus use efficiency is low a...

  19. Trace and rare-earth element geochemistry: A tool for petrogenetic and geotectonic modeling of ensi-matic ortho-amphibolites from Pan-African belt of Obudu Plateau, Southeastern Nigeria

    Institute of Scientific and Technical Information of China (English)

    Ukaegbu V.U.; Beka F.T.

    2009-01-01

    A model for the petrogenetic affinity and original geotectonic setting of ortho-amphibolites from the Obudu Plateau was tested using the distribution patterns of trace and rare-earth elements from the geochemical analyses of twelve representative amphibolite samples. Discrimination plots, normalized patterns of the incompatible trace elements against average MORB, low ratios of Ba/Nb (9-23) and Ba/Ta (130-327) and other geochemical characteristics suggest that the protoliths were dominantly of tholeiitic MORB composition. The values of the ratios of La/Ta (8.13-10.8), Rb/Sr (0.044).07), Th/U (mainly 4.43-5.43) and Hf/Ta (2.35-2.88) further indicate that the ortho-amphibolites demonstrate E-type MORB characteristics. These features are related to substantial ocean floor divergent tectonic boundary setting rather than marginal basin tectonic setting. This evolutionary pattern appears to be controlled by limited progressive partial melting and fractional crystallization of a single mantle source region, irrespective, however, of variations due to local source heterogeneities. The tholeiitic magmas were most probably generated by hotspot activities on the constructive plate margins and subsequently modified by subduction-related low-K tholeiitic chemistry due to narrowing of a proto oceanic basin between the West African craton and eastern Sahara plate. A likely model, therefore, is that the amphibolites of the Obudu Plateau represent ophiolitic suites with characteristics of enriched mid-ocean floor tholeiites, which were deformed and metamorphosed during a reversed plate motion involving subduction and collision within the Obudu Plateau in the Pan-African orogenic episode.

  20. New constraints on the Paleoarchean meteorite bombardment of the Earth - Geochemistry and Re-Os isotope signatures of spherule layers in the BARB5 ICDP drill core from the Barberton Greenstone Belt, South Africa

    Science.gov (United States)

    Schulz, Toni; Koeberl, Christian; Luguet, Ambre; van Acken, David; Mohr-Westheide, Tanja; Ozdemir, Seda; Reimold, Wolf Uwe

    2017-08-01

    Archean spherule layers, resulting from impacts by large extraterrestrial objects, to date represent the only remnants of the early meteorite, asteroid, and comet bombardment of the Earth. Only few Archean impact debris layers have been documented, all of them embedded in the 3.23-3.47 billion year old successions of the Barberton Greenstone Belt (BGB) in South Africa and the Pilbara Craton in Western Australia. Some of them might be correlated with each other. Given the scarcity of Archean spherule deposits, four spherule layer intersections from the recently recovered BARB5 drill core from the central Barberton Greenstone Belt, analyzed in this study, provide an opportunity to gain new insight into the early terrestrial impact bombardment. Despite being hydrothermally overprinted, siderophile element abundance signatures of spherule-rich samples from the BARB5 drill core, at least in part, retained a meteoritic fingerprint. The impact hypothesis for the generation of the BARB5 spherule layers is supported by correlations between the abundances of moderately (Cr, Co, Ni) and highly siderophile (Re, Os, Ir, Pt, Ru and Pd) elements, whose peak concentrations and interelement ratios are within the range of those for chondrites. Rhenium-Osmium isotope evidence further support the impact hypothesis. Collectively, this study provides evidence for extraterrestrial admixtures ranging between ∼40 and up to 100% to three of the four analyzed BARB5 spherule layers, and a scenario for their genesis involving (i) impact of a chondritic bolide into a sedimentary target, (ii) varying admixtures of meteoritic components to target materials, (iii) spherule formation via condensation in an impact vapor plume, (iv) transportation of the spherules and sedimentation under submarine conditions, followed by (v) moderate post-impact remobilization of transition metals and highly siderophile elements.

  1. The geology and geochemistry of Isla Floreana, Galápagos: A different type of late-stage ocean island volcanism: Chapter 6 in The Galápagos: A natural laboratory for the earth sciences

    Science.gov (United States)

    Harpp, Karen S.; Geist, Dennis J.; Koleszar, Alison M.; Christensen, Branden; Lyons, John; Sabga, Melissa; Rollins, Nathan; Harpp, Karen S.; Mittelstaedt, Eric; d'Ozouville, Noémi; Graham, David W

    2014-01-01

    Isla Floreana, the southernmost volcano in the Galápagos Archipelago, has erupted a diverse suite of alkaline basalts continually since 1.5 Ma. Because these basalts have different compositions than xenoliths and older lavas from the deep submarine sector of the volcano, Floreana is interpreted as being in a rejuvenescent or late-stage phase of volcanism. Most lavas contain xenoliths, or their disaggregated remains. The xenolithic debris and large ranges in composition, including during single eruptions, indicate that the magmas do not reside in crustal magma chambers, unlike magmas in the western Galápagos. Floreana lavas have distinctive trace element compositions that are rich in fluid-immobile elements (e.g., Ta, Nb, Th, Zr) and even richer in fluid-mobile elements (e.g., Ba, Sr, Pb). Rare earth element (REE) patterns are light REE-enriched and distinctively concave-up. Neodymium isotopic ratios are comparable to those from Fernandina, at the core of the Galápagos plume, but Floreana has the most radiogenic Sr and Pb isotopic ratios in the archipelago. These trace element patterns and isotopic ratios are attributed to a mixed source originating within the Galápagos plume, which includes depleted upper mantle, plume material rich in TITAN elements (Ti, Ta, Nb), and recycled oceanic crust that has undergone partial dehydration in an ancient subduction zone. Because Floreana lies at the periphery of the Galápagos plume, melting occurs mostly in the spinel zone, and enriched components dominate; the Floreana recycled mantle component influence is detectable in volcanoes along the entire southern periphery of the archipelago as well. Floreana is the only Galápagos volcano known to have undergone late-stage volcanism. Here, however, the secondary stage activity is more compositionally enriched than the shield-building phase, in contrast to what is observed in Hawai‘i, suggesting that the mechanism driving late-stage volcanism may vary among ocean island

  2. Geochemistry of rare earth elements (REEs) in coal from magmatic intrusion area from Wolonghu Coal Mine%卧龙湖煤矿岩浆侵入区煤中稀土元素的地球化学特征

    Institute of Scientific and Technical Information of China (English)

    姜萌萌; 刘桂建; 吴斌; 郑刘根

    2012-01-01

    以淮北卧龙湖煤矿包含岩浆岩、煤层的剖面为研究对象,通过对岩浆岩、煤岩混合带、高变质煤样品采集,结合逐级化学提取实验,采用等离子体质谱(ICP-MS)对原煤样、岩浆岩样、煤灰分以 及煤和岩浆岩逐级提取实验中各种提取物的稀土元素进行了测试,系统、深入地研究了稀土元素的含量特征、分布模式以及赋存状态.研究结果表明,岩浆岩在侵入过程中与煤层间发生一定的物质交换作用,岩样与煤样中的稀土元素分布模式相差较大,逐级化学提取实验结果表明煤和岩浆岩中稀土元素都是以硅酸盐结合态占主导,但煤中稀土元素主要来源于陆源碎屑的供给.%Magmatic rock samples and adjacent coal samples were collected from a vertical section in the Wolonghu Coal Mine, Huaibei. The chemical extraction experiments were carried out, and the abundances of rare earth elements (REEs) in samples and coal ashes were determined by inductively couple-plasma mass spectrometry (ICP-MS). The occurrences of REEs were studied using sequential chemical extraction Experiment (SCEE) in different extraction liquids and conditions. The characterizations of the concentration, distribution patterns and the occurrence of REEs were analyzed. The results show that exchange of material between the magma and the coals occurred in the process of magmatic intrusion. Due to the superimposition of coal-forming microenvironment and magmatic intrusion, the distribution patterns of magma and coals are different. The result of SCEE shows that REEs are mainly distributed in sialic state, and that the source of REEs is terrigenous.

  3. MASS BALANCE GEOCHEMISTRY OF THE RED EARTH IN SOUTHERN CHINA AND ITS ENVIRONMENTAL IMPLICATIONS%南方红土元素迁移特征及其古环境意义

    Institute of Scientific and Technical Information of China (English)

    熊尚发; 丁仲礼; 刘东生

    2001-01-01

    The soil responses to climatic changes are a key problem in the studies of global change. Soils in the past provide a valuable record for the understanding of the relationship between the soil and the climatic changes. Here we report a case study to the red earth section at Jiujiang City in southern China. This section is about 15m in thickness, and consists of two pedogenic units. The upper part is a layer of yellowish silty clay, while the lower part a layer of red clay with yellow and white worm-shaped veins. Mass-balance equations applied to geochemical analyses reveal that the degree of weathering increased down-section and the concentration of resistate constituents decreased upward. A pronounced depletion of bases(Na, K) has been shown in the lower part of the section. This weathering trend is not observed in the loess sections in northern China, and is probably the results of Quaternary climatic changes in southern China and of the variations in dust input resulting from the deterioration over central Asia.%气候变化下土壤物质过程的响应特征是全球变化研究的重要主题。本文选取江西九江剖面,通过协变分析,对其元素迁移特征进行了研究。结果显示,剖面上部(褐黄色土层)和剖面下部(网纹红土层)的协变状态和元素迁移强度有明显的差别,从盐基赋存状态看,剖面下部元素迁移强度大大高于剖面上部,同时,不同元素的迁移模式的表现明显不同。研究表明,剖面元素组成主要受古气候变化引起的风化强度差异的控制,但也在一定程度上受母质物源变化的影响。

  4. Earth Sciences Division annual report 1989

    Energy Technology Data Exchange (ETDEWEB)

    1990-06-01

    This Annual Report presents summaries of selected representative research activities from Lawrence Berkeley Laboratory grouped according to the principal disciplines of the Earth Sciences Division: Reservoir Engineering and Hydrology, Geology and Geochemistry, and Geophysics and Geomechanics. We are proud to be able to bring you this report, which we hope will convey not only a description of the Division's scientific activities but also a sense of the enthusiasm and excitement present today in the Earth Sciences.

  5. The distribution of inorganic phosphorus in modern sediments of the Bay of Biscay; La distribution du phosphore inorganique dans les sediments modernes du golfe de Gasgogne

    Energy Technology Data Exchange (ETDEWEB)

    Anschutz, P.; Hyacinthe, Ch.; Carbonel, P.; Jouanneau, J.M.; Jorissen, F. [Bordeaux-1 Univ., 33 - Talence (France). Dept. de Geologie et d`Oceanographie, UMR CNRS 5805

    1999-06-01

    The phosphorus geochemistry on the bay of Biscay margin shows that modern sediments represent a source of phosphate for overlying seawater. However, particulate phosphorus leached with an ascorbate solution and 1 N HCl remains constant in the sedimentary column which suggests that inorganic particulate phosphorus is trapped in the sediment. This is due to bioturbation, which carries iron oxides with high adsorption capacities for phosphate deep into the sediment, and also, to the precipitation of authigenic phosphate minerals in the anaerobic zone of the sediment. (authors) 17 refs.

  6. Applied Geochemistry Special Issue on Environmental geochemistry of modern mining

    Science.gov (United States)

    Seal, Robert R.; Nordstrom, D. Kirk

    2015-01-01

    Environmental geochemistry is an integral part of the mine-life cycle, particularly for modern mining. The critical importance of environmental geochemistry begins with pre-mining baseline characterization and the assessment of environmental risks related to mining, continues through active mining especially in water and waste management practices, and culminates in mine closure. The enhanced significance of environmental geochemistry to modern mining has arisen from an increased knowledge of the impacts that historical and active mining can have on the environment, and from new regulations meant to guard against these impacts. New regulations are commonly motivated by advances in the scientific understanding of the environmental impacts of past mining. The impacts can be physical, chemical, and biological in nature. The physical challenges typically fall within the purview of engineers, whereas the chemical and biological challenges typically require a multidisciplinary array of expertise including geologists, geochemists, hydrologists, microbiologists, and biologists. The modern mine-permitting process throughout most of the world now requires that potential risks be assessed prior to the start of mining. The strategies for this risk assessment include a thorough characterization of pre-mining baseline conditions and the identification of risks specifically related to the manner in which the ore will be mined and processed, how water and waste products will be managed, and what the final configuration of the post-mining landscape will be.In the Fall 2010, the Society of Economic Geologists held a short course in conjunction with the annual meeting of the Geological Society of America in Denver, Colorado (USA) to examine the environmental geochemistry of modern mining. The intent was to focus on issues that are pertinent to current and future mines, as opposed to abandoned mines, which have been the focus of numerous previous short courses. The geochemical

  7. Organic chemistry of elemental phosphorus

    Energy Technology Data Exchange (ETDEWEB)

    Milyukov, V A; Budnikova, Yulia H; Sinyashin, Oleg G [A.E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Centre of the Russian Academy of Sciences, Kazan (Russian Federation)

    2005-09-30

    The principal achievements and the modern trends in the development of the chemistry of elemental phosphorus are analysed, described systematically and generalised. The possibilities and advantages of the preparation of organophosphorus compounds directly from white phosphorus are demonstrated. Attention is focused on the activation and transformation of elemental phosphorus in the coordination sphere of transition metal complexes. The mechanisms of the reactions of white phosphorus with nucleophilic and electrophilic reagents are discussed. Electrochemical approaches to the synthesis of organic phosphorus derivatives based on white phosphorus are considered.

  8. Low Phosphorus Diet: Best for Kidney Disease?

    Science.gov (United States)

    ... diet: Best for kidney disease? Why is a low-phosphorus diet useful in managing kidney disease? What ... choose foods that are lower in phosphorus. Choose low-phosphorus foods The best way to limit phosphorus ...

  9. III. Quantitative aspects of phosphorus excretionin ruminants

    OpenAIRE

    Bravo, David; Sauvant, Daniel; Bogaert, Catherine; Meschy, François

    2003-01-01

    International audience; Ruminant phosphorus excretion and metabolism were studied through a database. Faecal endogenous phosphorus is the main pathway of phosphorus excretion and averages 0.85 of total faecal phosphorus. The remaining 0.15 is unabsorbed dietary phosphorus. Faecal endogenous phosphorus is mainly unabsorbed phosphorus, with saliva being the major source, and is correlated to factors influencing saliva secretion (DM intake, physical dietary characteristics and dietary phosphorus...

  10. The Marine Geochemistry of the Rare Earth Elements

    Science.gov (United States)

    1983-09-01

    constants for iminodiacetic acid and N-benzylimino- diacetic acid with Rare Eartn ions at 250C and I = 0.1 ionic strength ( KNO3 medium)(Taken from...Unclassified Unlimited Distribution 2. Security Class (This Page) 22. Price (See ANSI.-Z39.’I) See Instructions on Reverse OPTIONAL FORM 272 (4-771 (Formely NTIS

  11. phosphorus retention data and metadata

    Data.gov (United States)

    U.S. Environmental Protection Agency — phosphorus retention in wetlands data and metadata. This dataset is associated with the following publication: Lane , C., and B. Autrey. Phosphorus retention of...

  12. GEOCHEMISTRY

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20110807 Li Chao(National Research Center for Geoanalysis,Beijing 100037,China);Qu Wenjun Advances in the Study of the Re-Os Isotopic System of Organic-Rich Samples(Acta Petrologica et Mineralogica,ISSN1000-6524,CN11-1966/P,29(4),2010,p.421-430,3 illus.,1 table,45 refs.)Key words:organic compounds,rhenium isotopes,osmium isotopes This paper deals with the principles of Re-Os isotopic system applied to various organic-rich geological samples such as black shale,oil shale,asphalt,schungite,oil and coal.Moreover,the potential disturbances of the weathering-leaching and the hydrocarbon maturation to the closure of Re-Os isotopic system are analyzed.In the aspect of practical application,several cases are cited to illustrate the significance of this isotopic system in the organic-rich

  13. GEOCHEMISTRY

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>20140692 Duo Tianhui(No.402 Geological Team,Exploration of Geology and Mineral Resources of Sichuan Authority,Chengdu611730,China);Wang Yongli Computer Simulation of Neptunium Existing Forms in the Groundwater(Computing Techniques for Geophysical and Geochemical Exploration,ISSN1001-1749,CN51-1242/P,35(3),

  14. GEOCHEMISTRY

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>20141357 Guo Tao(School of Mathematics and Science,Shijiazhuang University of Economics,Shijiazhuang 050031,China);Hu Jiawen Assessment on the New Pressure-Volume-Temperature(PVT) Data of Supercritical Water(Geological Journal of China Universities,ISSN1006-7493,CN32-1440/P,19(3),2013,p.447-455,9 illus.,3 tables,32 refs.)Key words:supercritical fluids

  15. GEOCHEMISTRY

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>20131468 Zhang Yuanpei(Hubei Institute of Geophysical Exploration Technology,Wuhan430056,China);Huan Chunjuan Geochemical Characteristics of Trace Elements in the Diorite Weathered Crust of Zigui Area(Geophysical and Geochemical Exploration,ISSN1000-

  16. GEOCHEMISTRY

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>20082178 Cheng Liangjuan(College of Re- sources and Environmental Sciences,Nanjing Agricultural University,Nanjing 210095, China);Li Fuchun Adsorption of Silicate Bacteria on Surface of Orthoclase and Biotite and Its Selectivity(Geological Journal of Chi- na Universities,ISSN1006—7493,CN32—1440/P,13 (4),2007,p.669—674,4 illus.,21 refs.,with English abstract) Key words:silicates,bacteria

  17. Phosphorus derivatives of salicylic acid

    Science.gov (United States)

    Chvertkina, L. V.; Khoklov, P. S.; Mironov, Vladimir F.

    1992-10-01

    The present state of work on the methods of synthesis, chemical properties, and practical applications of phosphorus-containing derivatives of salicylic acid has been reviewed. The characteristics of the chemical transformations of cyclic and acyclic phosphorus derivatives of salicylic acid related to the coordination state of the phosphorus atom have been examined. The bibliography includes 158 references.

  18. In Situ Instrumentation for Sub-Surface Planetary Geochemistry

    Science.gov (United States)

    Bodnarik, J.; Evans, L.; Floyd, S.; Lim, L.; McClanahan, T.; Namkung, M.; Parsons, A.; Schweitzer, J.; Starr, R.; Trombka, J.

    2010-01-01

    Novel instrumentation is under development at NASA's Goddard Space Flight Center, building upon earth-based techniques for hostile environments, to infer geochemical processes important to formation and evolution of solid bodies in our Solar System. A prototype instrument, the Pulsed Neutron Generator Gamma Ray and Neutron Detectors (PNG-GRAND), has a 14 MeV pulsed neutron generator coupled with gamma ray and neutron detectors to measure quantitative elemental concentrations and bulk densities of a number of major, minor and trace elements at or below the surfaces with approximately a meter-sized spatial resolution down to depths of about 50 cm without the need to drill. PNG-GRAND's in situ a meter-scale measurements and adaptability to a variety of extreme space environments will complement orbital kilometer-scale and in-situ millimeter scale elemental and mineralogical measurements to provide a more complete picture of the geochemistry of planets, moons, asteroids and comets.

  19. Phosphorus Deficiency in Ducklins

    Institute of Scientific and Technical Information of China (English)

    CuiHengmin; LuoLingping

    1995-01-01

    20 one-day-old Tianfu ducklings were fed on a natural diet deficient in phosphorus(Ca 0.80%,P 0.366%)for three weeks and examined for signs and lesions.Signs began to appear at the age of one week,and became serous at two weeks.13 ducklings died during the experiment.Morbidity was 100% and mortality was 65%.The affected ducklings mainly showed leg weakness,severe lamencess,deprssion,lack of appetite and stunted growth,The serum alkaline phosphatase activities increased markedly.The serum phosphorus concentration,tibial ash,ash calcium and phosphorus content decreased obviously.At necropsy,maxillae and ribe were soft,and the latter was crooked.Long ones were soft and broke easily.The hypertrophic zone of the growth-plate in the epiphysis of long ones was lengthened and osteoid tissue increased in the metaphyseal spongiosa histopathologically.The above mentioned symptoms and lesions could be prevented by adding phosphorus to the natural deficient diet(up to 0.65%),The relationship between lesions and signs,pathomorphological characterisation and pathogensis were also discussed in this paper.

  20. Phosphorus cycling in the deep subseafloor biosphere at North Pond

    Science.gov (United States)

    Defforey, D.; Paytan, A.

    2013-12-01

    Phosphorus is a macronutrient involved both in functional and structural components of all living cells. This makes it an essential nutrient for life, including microbial life in the deep subseafloor habitat. Phosphorus availability in this environment is limited since it is thought to be mainly present in refractory mineral phases. However, recent estimates suggest that the deep biosphere may contain up to 1% of Earth's total biomass, which implies that microorganisms may possess mechanisms to harvest recalcitrant phosphorus compounds in this environment. This study sheds light on those mechanisms by investigating phosphorus cycling in deep open-ocean sediments using stable oxygen isotope ratios in phosphate. Furthermore, this study provides insight into changes in phosphorus bioavailability and mobility under a range of natural environmental conditions within the deep biosphere. Sediment samples were collected from four boreholes drilled during the IODP Expedition 336 to North Pond, an isolated sediment pond on the western flank of the Mid-Atlantic Ridge. Sedimentary phosphorus compounds are characterized using sequential extractions (SEDEX), which separate them into five distinct pools. Phosphate from the various extracts are then concentrated, purified through a series of steps, then converted to silver phosphate, which is pyrolyzed and analyzed by continuous-flow isotope ratio mass spectrometry (CF-IRMS). The isotopic signatures and/or fractionations associated with many of the potential reactions and transformations operating in the P cycle have been determined, and provide the basis for interpreting isotopic data that are obtained from the phosphate extracts.

  1. Advances in the Study of Geochemistry and Paleo-oceanography of the Co-rich Crust

    Institute of Scientific and Technical Information of China (English)

    Cai Yihua; Huang Yipu

    2002-01-01

    The current advances in the study of geochemistry and paleo-oceanography of the Co-rich crust are reviewed in this paper. We summarize the study of geochemistry of the Co-rich crust, discuss the diffusion of elements in the Co-rich crust and the exchange with ambient seawater. Besides, we discuss the effect of phosphatization and substrate rocks on the composition of the Co-rich crust. We also introduce the application of stable isotopes (including the stable isotopes of Pb, Nd, and Hf), radioactive isotopes (including the radioactive isotopes of Be, U and Th), and elements (including the major elements, minor elements and rare earth elements) to the study of paleo-oceanography of the Co-rich crust.

  2. Earth Abides Arsenic Biotransformations

    Science.gov (United States)

    Zhu, Yong-Guan; Yoshinaga, Masafumi; Zhao, Fang-Jie; Rosen, Barry P.

    2014-05-01

    Arsenic is the most prevalent environmental toxic element and causes health problems throughout the world. The toxicity, mobility, and fate of arsenic in the environment are largely determined by its speciation, and arsenic speciation changes are driven, at least to some extent, by biological processes. In this article, biotransformation of arsenic is reviewed from the perspective of the formation of Earth and the evolution of life, and the connection between arsenic geochemistry and biology is described. The article provides a comprehensive overview of molecular mechanisms of arsenic redox and methylation cycles as well as other arsenic biotransformations. It also discusses the implications of arsenic biotransformation in environmental remediation and food safety, with particular emphasis on groundwater arsenic contamination and arsenic accumulation in rice.

  3. Earth Abides Arsenic Biotransformations

    Science.gov (United States)

    Zhu, Yong-Guan; Yoshinaga, Masafumi; Zhao, Fang-Jie; Rosen, Barry P.

    2015-01-01

    Arsenic is the most prevalent environmental toxic element and causes health problems throughout the world. The toxicity, mobility, and fate of arsenic in the environment are largely determined by its speciation, and arsenic speciation changes are driven, at least to some extent, by biological processes. In this article, biotransformation of arsenic is reviewed from the perspective of the formation of Earth and the evolution of life, and the connection between arsenic geochemistry and biology is described. The article provides a comprehensive overview of molecular mechanisms of arsenic redox and methylation cycles as well as other arsenic biotransformations. It also discusses the implications of arsenic biotransformation in environmental remediation and food safety, with particular emphasis on groundwater arsenic contamination and arsenic accumulation in rice. PMID:26778863

  4. Earth Sciences annual report, 1987

    Energy Technology Data Exchange (ETDEWEB)

    Younker, L.W.; Donohue, M.L.; Peterson, S.J. (eds.)

    1988-12-01

    The Earth Sciences Department at Lawrence Livermore National Laboratory conducts work in support of the Laboratory's energy, defense, and research programs. The Department is organized into ten groups. Five of these -- Nuclear Waste Management, Fossil Energy, Containment, Verification, and Research -- represent major programmatic activities within the Department. Five others -- Experimental Geophysics, Geomechanics, Geology/Geological Engineering, Geochemistry, and Seismology/Applied Geophysics -- are major disciplinary areas that support these and other laboratory programs. This report summarizes work carried out in 1987 by each group and contains a bibliography of their 1987 publications.

  5. Organic geochemistry - A retrospective of its first 70 years

    Science.gov (United States)

    Kvenvolden, K.A.

    2006-01-01

    Organic geochemistry had its origin in the early part of the 20th century when organic chemists and geologists realized that detailed information on the organic materials in sediments and rocks was scientifically interesting and of practical importance. The generally acknowledged "father" of organic geochemistry is Alfred E. Treibs (1899-1983), who discovered and described, in 1936, porphyrin pigments in shale, coal, and crude oil, and traced the source of these molecules to their biological precursors. Thus, the year 1936 marks the beginning of organic geochemistry. However, formal organization of organic geochemistry dates from 1959 when the Organic Geochemistry Division (OGD) of The Geochemical Society was founded in the United States, followed 22 years later (1981) by the establishment of the European Association of Organic Geochemists (EAOG). Organic geochemistry (1) has its own journal, Organic Geochemistry (beginning in 1979) which, since 1988, is the official journal of the EAOG, (2) convenes two major conferences [International Meeting on Organic Geochemistry (IMOG), since 1962, and Gordon Research Conferences on Organic Geochemistry (GRC), since 1968] in alternate years, and (3) is the subject matter of several textbooks. Organic geochemistry is now a widely recognized geoscience in which organic chemistry has contributed significantly not only to geology (i.e., petroleum geochemistry, molecular stratigraphy) and biology (i.e., biogeochemistry), but also to other disciplines, such as chemical oceanography, environmental science, hydrology, biochemical ecology, archaeology, and cosmochemistry.

  6. Responses of Legumes to Phosphorus Deficiency

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Phosphorus deficiency is a universal problem in most world soils. Furthermore, of all nutrients, shortage of phosphorus has the biggest impact on legumes, therefore, lots of studies were carried out for identifying responses of legumes to shortage of phosphorus. They concluded that to maintain improved growth under phosphorus deficiency conditions plants develop two major mechanisms: (i) Phosphorus acquisition (root morphology, root exudation and phosphorus uptake mechanisms), (ii) Phosphorus utilization (internal mechanisms associated with better use of absorbed phosphorus at cellular level). The aim of this brief review is to elucidate root morphological changes and rhizophere acidification to phosphorus deficiency.

  7. Characterization and sonochemical synthesis of black phosphorus from red phosphorus

    Science.gov (United States)

    Aldave, Sandra H.; Yogeesh, Maruthi N.; Zhu, Weinan; Kim, Joonseok; Sonde, Sushant S.; Nayak, Avinash P.; Akinwande, Deji

    2016-03-01

    Phosphorene is a new two-dimensional material which is commonly prepared by exfoliation from black phosphorus bulk crystals that historically have been synthesized from white phosphorus under high-pressure conditions. The few layers of phosphorene have a direct band gap in the range of 0.3-2 eV and high mobility at room temperature comparable to epitaxial graphene. These characteristics can be used for the design of high speed digital circuits, radio frequency circuits, flexible and printed systems, and optoelectronic devices. In this work, we synthesized black phosphorus from red phosphorus, which is a safer solid precursor, using sonochemistry. Furthermore, via a variety of microscopy and spectroscopy techniques, we report characterization results of the sonochemically synthesized black phosphorus in addition to the commercial black phosphorus. Finally, we describe the air stability of black phosphors and the crystalline structure of the synthesized material. This is the first result of sonochemical or solution-based synthesis of black phosphorus based on readily available low-cost red phosphorus. This solution-based synthesis of black phosphorus is suitable for printable applications of nanomaterial.

  8. Impact of seasonal oxygen deficiency on the phosphorous geochemistry of surface sediments along the Western Continental Shelf of India

    Directory of Open Access Journals (Sweden)

    Josia Jacob

    2010-08-01

    Full Text Available The intensification of the natural coastal hypoxic zone over the western Indian shelf in the recent years and its impact on the biogeochemistry and marine life is a matter of concern. This study examines the influence of the seasonal oxygen deficiency on the phosphorus geochemistry of the surface sediments along the western continental shelf of India (WCSI. Speciation of phosphorus along with the geochemical characteristics (total organic carbon – TOC, total nitrogen – TN, and total phosphorus – TP of the surface sediments and the hydrography of the western continental shelf of India (WCSI were studied, during late summer monsoon (LSM and spring intermonsoon (SIM. The hydrography of the WCSI revealed upwelling and associated seasonal oxygen deficiency with denitrifying suboxic conditions along the inner shelf and hypoxic conditions along the outer shelf. High concentrations of dissolved phosphate (PO4 and dissolved Iron (Fe were also observed in the subsurface water of the inner shelf during LSM. The shelf water of the WCSI was oligotrophic and oxygen rich during SIM. A latitudinal enrichment of TOC, TN and TP in the surface sediments was observed at 13–17° N, along the WCSI during LSM, where seasonal suboxia was intense. Authigenic apatite bound phosphorus (Paut was the major phosphorus species along the WCSI during LSM whereas detrital flourapatite bound phosphorus (Pdet was the major species during SIM. Substantial depletion of reactive iron(III-bound phosphorus (ΔPFe was observed in the surface sediments of the WCSI during LSM which showed significant correlation with the enrichment of PO4 (ΔPO4 in the overlying water during LSM compared to SIM. PO4 diffusing into the water column from the sediments by reductive dissolution of PPFe probably leads to high dissolved PO4 along the inner shelf water during LSM which agrees with the

  9. Geochemistry of sulfur in the Florida Everglades; 1994 through 1999

    Science.gov (United States)

    Bates, Anne L.; Orem, W.H.; Harvey, J.W.; Spiker, E. C.

    2000-01-01

    In this report, we present data on the geochemistry of sulfur in sediments and in surface water, groundwater, and rainwater in the Everglades region in south Florida. The results presented here are part of a larger study intended to determine the roles played by the cycling of carbon, nitrogen, phosphorus, and sulfur in the ecology of the south Florida wetlands. The geochemistry of sulfur in the region is particularly important because of its link to the production of toxic methylmercury through processes mediated by sulfate reducing bacteria. Sediment cores were collected from the Everglades Agricultural Area (EAA), Water Conservation Areas (WCAs) 1A and 2A, from Lake Okeechobee, and from Taylor Slough in the southern Everglades. Water collection was more widespread and includes surface water from WCAs 1A, 2A, 3A, 2B, the EAA, Taylor Slough, Lake Okeechobee, and the Kissimmee River. Groundwater was collected from The Everglades Nutrient Removal Area (ENR) and from WCA 2A. Rainwater was collected at two month intervals over a period of one year from the ENR and from WCA 2A. Water was analyzed for sulfate concentration and sulfate sulfur stable isotopic ratio (34S/32S). Sediment cores were analyzed for total sulfur concentration and/or for concentrations of sulfur species (sulfate, organic sulfur, disulfides, and acid volatile sulfides (AVS)) and for their stable sulfur isotopic ratio. Results show a decrease in total sulfur content (1.57 to 0.61 percent dry weight) with depth in two sediment cores collected in WCA 2A, indicating that there has been an increase in total sulfur content in recent times. A sediment core from the center of Lake Okeechobee shows a decrease in total sulfur content with depth (0.28 to 0.08 percent dry weight). A core from the periphery of the lake (South Bay) likewise shows a decrease in total sulfur content with depth (1.00 to 0.69 percent dry weight), however, the overall sulfur content is greater than that near the center at all depths

  10. Sustainable Phosphorus Measures: Strategies and Technologies for Achieving Phosphorus Security

    Directory of Open Access Journals (Sweden)

    Stuart White

    2013-01-01

    Full Text Available Phosphorus underpins the world’s food systems by ensuring soil fertility, maximising crop yields, supporting farmer livelihoods and ultimately food security. Yet increasing concerns around long-term availability and accessibility of the world’s main source of phosphorus—phosphate rock, means there is a need to investigate sustainable measures to buffer the world’s food systems against the long and short-term impacts of global phosphorus scarcity. While the timeline of phosphorus scarcity is contested, there is consensus that more efficient use and recycling of phosphorus is required. While the agricultural sector will be crucial in achieving this, sustainable phosphorus measures in sectors upstream and downstream of agriculture from mine to fork will also need to be addressed. This paper presents a comprehensive classification of all potential phosphorus supply- and demand-side measures to meet long-term phosphorus needs for food production. Examples range from increasing efficiency in the agricultural and mining sector, to technologies for recovering phosphorus from urine and food waste. Such measures are often undertaken in isolation from one another rather than linked in an integrated strategy. This integrated approach will enable scientists and policy-makers to take a systematic approach when identifying potential sustainable phosphorus measures. If a systematic approach is not taken, there is a risk of inappropriate investment in research and implementation of technologies and that will not ultimately ensure sufficient access to phosphorus to produce food in the future. The paper concludes by introducing a framework to assess and compare sustainable phosphorus measures and to determine the least cost options in a given context.

  11. Historical foundations of chemical geology and geochemistry

    NARCIS (Netherlands)

    Manten, A.A.

    1966-01-01

    Roughly, the name chemical geology has been used for as long as chemistry has been applied in geology; the name geochemistry was introduced by Schönbein, in 1838. Whereas initially the names were often regarded as synonymous, in our century there is a tendency to make a distinction between the two o

  12. Geochemistry of sulphur in petroleum systems

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Orr, W.L.

    1990-01-01

    A renaissance in the 1980s concerning geochemistry of sulfur in fossil fuels makes an update of the subject timely. Papers developed from the 1989 ACS Symposium in Dallas provide a cross-section of recent research and progress in our understanding of the abundance and nature of organically bound

  13. Geochemistry of sulphur in petroleum systems

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Orr, W.L.

    1990-01-01

    A renaissance in the 1980s concerning geochemistry of sulfur in fossil fuels makes an update of the subject timely. Papers developed from the 1989 ACS Symposium in Dallas provide a cross-section of recent research and progress in our understanding of the abundance and nature of organically bound sul

  14. Geochemistry of coalbed gas - a review

    Science.gov (United States)

    Clayton, J.L.

    1998-01-01

    Coals are both sources and reservoirs of large amounts of gas that has received increasing attention in recent years as a largely untapped potential energy resource. Coal mining operations, such as ventilation of coalbed gas from underground mines, release coalbed CH4 into the atmosphere, an important greehouse gas whose concentration in the atmosphere is increasing. Because of these energy and environmental issues, increased research attention has been focused on the geochemistry of coalbed gas in recent years. This paper presents a summary review of the main aspects of coalbed gas geochemistry and current research advances.Coals are both sources and reservoirs of large amounts of gas that has received increasing attention in recent years as a largely untapped potential energy resource. Coal mining operations, such as ventilation of coalbed gas from underground mines, release coalbed CH4 into the atmosphere, an important greenhouse gas whose concentration in the atmosphere is increasing. Because of these energy and environmental issues, increased research attention has been focused on the geochemistry of coalbed gas in recent years. This paper presents a summary review of the main aspects of coalbed gas geochemistry and current research advances.

  15. Application of neogeographic tools for geochemistry

    Science.gov (United States)

    Zhilin, Denis

    2010-05-01

    Neogeography is a usage of geographical tools for utilization by a non-expert group of users. It have been rapidly developing last ten years and is founded on (a) availability of Global Positioning System (GPS) receivers, that allows to obtain very precise geographical position (b) services, that allows linking geographical position with satellite images, GoogleEarth for example and (c) programs as GPS Track Maker or OziExplorer, that allows linking geographical coordinates with other raster images (for example, maps). However, the possibilities of neogeographic approach are much wider. It allows linking different parameters with geographical coordinates on the one hand and space image or map - on the other. If it is easy to measure a parameter, a great database could be collected for a very small time. The results can be presented in very different ways. One can plot a parameter versus the distance from a particular point (for example, a source of a substance), make two-dimension distribution of parameter of put the results onto a map or space image. In the case of chemical parameters it can help finding the source of pollution, trace the influence of pollution, reveal geochemical processes and patterns. The main advantage of neogeograpic approach is the employment of non-experts in collecting data. Now non-experts can easily measure electrical conductivity and pH of natural waters, concentration of different gases in the atmosphere, solar irradiation, radioactivity and so on. If the results are obtained (for example, by students of secondary schools) and shared, experts can proceed them and make significant conclusions. An interface of sharing the results (http://maps.sch192.ru/) was elaborated by V. Ilyin. Within the interface a user can load *.csv file with coordinates, type of parameter and the value of parameter in a particular point. The points are marked on the GoogleEarth map with the color corresponding the value of the parameter. The color scale can be

  16. Geochemical Constraints on Core Formation in the Earth

    Science.gov (United States)

    Jones, John H.; Drake, Michael J.

    1986-01-01

    New experimental data on the partitioning of siderophile and chalcophile elements among metallic and silicate phases may be used to constrain hypotheses of core formation in the Earth. Three current hypotheses can explain gross features of mantle geochemistry, but none predicts siderophile and chalcophile element abundances to within a factor of two of observed values. Either our understanding of metal-silicate interactions and/or our understanding of the early Earth requires revision.

  17. Reservoir geochemistry. A reservoir engineering perspective

    Energy Technology Data Exchange (ETDEWEB)

    England, W.A. [BP Exploration, Chertsey Road, Sunbury-on-Thames, Middlesex, TW16 7LN (United Kingdom)

    2007-09-15

    This paper reviews the applications of reservoir geochemistry from a reservoir engineering point of view. Some of the main tasks of reservoir engineering are discussed with an emphasis on the importance of appraising reservoirs in the pre-development stage. A brief review of the principal methods and applications of reservoir geochemistry are given, in the context of applications to reservoir engineering problems. The importance of compositional differences in fluid samples from different depths or spatial locations is discussed in connection with the identification of internal flow barriers. The importance of understanding the magnitude and origin of vertical compositional gradients is emphasised because of possible confusion with purely lateral changes. The geochemical origin and rate of dissipation of compositional differences over geological time is discussed. Geochemical techniques suitable for bulk petroleum fluid samples include GC fingerprinting, GCMS, isotopic and PVT measurements. Core sample petroleum extracts may also be studied by standard geochemical methods but with the added complication of possible contamination by drilling mud. Aqueous phase residual salt extracts can be studied by strontium isotope analysis from core samples. Petroleum fluid inclusions allow the possibility of establishing the composition of paleo-accumulations. The problems in predicting flow barriers from geochemical measurements are discussed in terms of 'false positives' and 'false negatives'. Suggestions are made for areas that need further development in order to encourage the wider acceptance and application of reservoir geochemistry by the reservoir engineering community. The importance of integrating all available data is emphasised. Reservoir geochemistry may be applied to a range of practical engineering problems including production allocation, reservoir compartmentalisation, and the prediction of gravitational gradients. In this review

  18. Annual review of earth and planetary sciences. Volume 17

    Energy Technology Data Exchange (ETDEWEB)

    Wetherill, G.W.; Albee, A.L.; Stehli, F.G.

    1989-01-01

    Recent advances in earth and planetary science are examined in reviews by leading experts. The subjects discussed include geochemistry and the dynamics of the Yellowstone hydrothermal system, Alpine and Himalayan blueschists, pressure solution during diagenesis, achondrites and igneous processes on asteroids, Sr isotopes in seawater, sediment magnetization and the evolution of magnetite biomineralization, active deformation of the continents, the nature of deep-focus earthquakes, and the use of Raman spectroscopy in mineralogy and geochemistry. Consideration is given to the mechanics of faulting, the crustal structure of western Europe, gases in diamonds, metamorphic fluids in the deep crust, faunal dynamics of pleistocene mammals, magma chambers, and the nature of the Mohorovicic discontinuity.

  19. Naturally occurring radionuclides and Earth sciences

    Directory of Open Access Journals (Sweden)

    G. Ferrara

    1997-06-01

    Full Text Available Naturally occurring radionuclides are used in Earth sciences for two fundamental purposes: age determination of rocks and minerals and studies of variation of the isotopic composition of radiogenic nuclides. The methodologies that are in use today allow us to determine ages spanning from the Earth's age to the late Quaternary. The variations of isotopic composition of radiogenic nuclides can be applied to problems of mantle evolution, magma genesis and characterization with respect to different geodynamic situations and can provide valuable information not obtainable by elemental geochemistry.

  20. PHOSPHORUS REMOVAL USING STEEL SLAG

    Institute of Scientific and Technical Information of China (English)

    Y.Z. Lan; S. Zhang; J.K. Wang; R. W. Smith

    2006-01-01

    Steel slag is a byproduct produced in large amounts in the steel-making process. It is an important resource that can be effectively utilized. An experiment was described in which steel slag was tested as an adsorbent for the removal of phosphorus from waste water. Phosphorus removal depended on the amount of steel slag added, the pH value, the contact time, and the initial concentration. Under laboratory conditions when the added slag was 7.5g/L, the contact time 2h, and the pH value was equivalent to 6.5, over 99% of the phosphorus was removed; the experimental data on steel slag adsorption of phosphorus in the water fitted the Freundlich isotherm model. Steel slag was found to be very effective in adsorbing phosphorus.

  1. Virtual phosphorus ore requirement of Japanese economy.

    Science.gov (United States)

    Matsubae, Kazuyo; Kajiyama, Jun; Hiraki, Takehito; Nagasaka, Tetsuya

    2011-08-01

    Phosphorus is indispensable for agricultural production. Hence, the consumption of imported food indirectly implies the import of phosphorus resources. The global consumption of agricultural products depends on a small number of ore-producing countries. For sustainable management of phosphorus resources, the global supply and demand network should be clarified. In this study, we propose the virtual phosphorus ore requirement as a new indicator of the direct and indirect phosphorus requirements for our society. The virtual phosphorus ore requirement indicates the direct and indirect demands for phosphorus ore transformed into agricultural products and fertilizer. In this study, the virtual phosphorus ore requirement was evaluated for the Japanese economy in 2005. Importantly, the results show that our society requires twice as much phosphorus ore as the domestic demand for fertilizer production. The phosphorus contained in "eaten" agricultural products was only 12% of virtual phosphorus ore requirement.

  2. Incorporating phosphorus cycling into global modeling efforts: a worthwhile, tractable endeavor

    Science.gov (United States)

    Reed, Sasha C.; Yang, Xiaojuan; Thornton, Peter E.

    2015-01-01

    Myriad field, laboratory, and modeling studies show that nutrient availability plays a fundamental role in regulating CO2 exchange between the Earth's biosphere and atmosphere, and in determining how carbon pools and fluxes respond to climatic change. Accordingly, global models that incorporate coupled climate–carbon cycle feedbacks made a significant advance with the introduction of a prognostic nitrogen cycle. Here we propose that incorporating phosphorus cycling represents an important next step in coupled climate–carbon cycling model development, particularly for lowland tropical forests where phosphorus availability is often presumed to limit primary production. We highlight challenges to including phosphorus in modeling efforts and provide suggestions for how to move forward.

  3. Geochemistry of surficial sediments along the central southwest coast of India - Seasonal changes in regional distribution

    Digital Repository Service at National Institute of Oceanography (India)

    Balachandran, K.K.; Joseph, T.; Nair, M.; Sankaranarayanan, V.N.; Das, V.K.; Sheeba, P.

    carbon of the composite samples using wet digestion (chromic acid) followed by back titration with ferrous ammonium sulphate (EL WAKEEL and RILEY, 1957, precision::':: 0.25%). Finely powdered and dried (at 105 0 ::':: 5°C) sediments were digested in a...-earth element;; in the fluvial fraction « 4 IJ-m) that also date back to one~ct of sampling during 1981. Inadequacies in all the above stud ies have been their proper addressing of the influence 'If Seasonal Analysis of Sediment Geochemistry 665 Legend: PALL...

  4. Earth Sciences Division annual report 1990

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1991-06-01

    This Annual Report presents summaries of selected representative research activities grouped according to the principal disciplines of the Earth Sciences Division: Reservoir Engineering and Hydrogeology, Geology and Geochemistry, and Geophysics and Geomechanics. Much of the Division`s research deals with the physical and chemical properties and processes in the earth`s crust, from the partially saturated, low-temperature near-surface environment to the high-temperature environments characteristic of regions where magmatic-hydrothermal processes are active. Strengths in laboratory and field instrumentation, numerical modeling, and in situ measurement allow study of the transport of mass and heat through geologic media -- studies that now include the appropriate chemical reactions and the hydraulic-mechanical complexities of fractured rock systems. Of particular note are three major Division efforts addressing problems in the discovery and recovery of petroleum, the application of isotope geochemistry to the study of geodynamic processes and earth history, and the development of borehole methods for high-resolution imaging of the subsurface using seismic and electromagnetic waves. In 1989 a major DOE-wide effort was launched in the areas of Environmental Restoration and Waste Management. Many of the methods previously developed for and applied to deeper regions of the earth will in the coming years be turned toward process definition and characterization of the very shallow subsurface, where man-induced contaminants now intrude and where remedial action is required.

  5. Geochemistry of Fine-grained Sediments and Sedimentary Rocks

    Science.gov (United States)

    Sageman, B. B.; Lyons, T. W.

    2003-12-01

    The nature of detrital sedimentary (siliciclastic) rocks is determined by geological processes that occur in the four main Earth surface environments encountered over the sediment's history from source to final sink: (i) the site of sediment production (provenance), where interactions among bedrock geology, tectonic uplift, and climate control weathering and erosion processes; (ii) the transport path, where the medium of transport, gradient, and distance to the depositional basin may modify the texture and composition of weathered material; (iii) the site of deposition, where a suite of physical, chemical, and biological processes control the nature of sediment accumulation and early burial modification; and (iv) the conditions of later burial, where diagenetic processes may further alter the texture and composition of buried sediments. Many of these geological processes leave characteristic geochemical signatures, making detrital sedimentary rocks one of the most important archives of geochemical data available for reconstructions of ancient Earth surface environments. Although documentation of geochemical data has long been a part of the study of sedimentation (e.g., Twenhofel, 1926, 1950; Pettijohn, 1949; Trask, 1955), the development and application of geochemical methods specific to sedimentary geological problems blossomed in the period following the Second World War ( Degens, 1965; Garrels and Mackenzie, 1971) and culminated in recent years, as reflected by the publication of various texts on marine geochemistry (e.g., Chester, 1990, 2000), biogeochemistry (e.g., Schlesinger, 1991; Libes, 1992), and organic geochemistry (e.g., Tissot and Welte, 1984; Engel and Macko, 1993).Coincident with the growth of these subdisciplines a new focus has emerged in the geological sciences broadly represented under the title of "Earth System Science" (e.g., Kump et al., 1999). Geochemistry has played the central role in this revolution (e.g., Berner, 1980; Garrels and Lerman

  6. SPATIAL Short Courses Build Expertise and Community in Isotope Geochemistry

    Science.gov (United States)

    Riggs, E. M.; Bowen, G. J.

    2015-12-01

    The SPATIAL short course at the University of Utah is designed for graduate students and professionals in the earth and environmental sciences from around the globe. An integral part of the broader, NSF-funded Inter-university Training for Continental-scale Ecology (ITCE) project, the course is an intensive two-week field, classroom and laboratory experience with internationally-known researchers as instructors. The course focuses on stable isotope geochemistry coupled with spatial analysis techniques. Participants do not typically know each other or this research community well upon entering. One of the stated goals of the overall project is to build a community of practice around these techniques. This design is common in many professional fields, but is not often applied at the graduate level nor formally assessed in the earth sciences. Paired pre- and post-tests were administered before the start and after the close of the short courses over 3 years. The survey is a set of instruments adapted from social-cognitive psychology measuring changes in identity and community with other items to measure content knowledge outcomes. We see a subtle, consistent convergence of identities between large-scale isotope geochemistry and participants' research areas. Results also show that the course generates an increase in understanding about stable isotopes' use and application. The data show the SPATIAL course is very effective at bringing students together socially with each other and with faculty to create an environment that fosters community and scientific cooperation. Semi-structured pre-and post- interviews were conducted to understand the program elements that generated gains in learning and community. Participants were selected based on initial responses on the pre-survey to capture the range of initial conditions for the group. Qualitative analysis shows that the major factors for participants were 1) ready access to researchers in an informal setting during the

  7. Handbook of environmental isotope geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Baskaran, Mark (ed.) [Wayne State Univ., Detroit, MI (United States). Dept. Geology

    2011-07-01

    Applications of radioactive and stable isotopes have revolutionized our understanding of the Earth and near-earth surface processes. The utility of the isotopes are ever-increasing and our sole focus is to bring out the applications of these isotopes as tracers and chronometers to a wider audience so that they can be used as powerful tools to solve environmental problems. New developments in this field remain mostly in peer-reviewed journal articles and hence our goal is to synthesize these findings for easy reference for students, faculty, regulators in governmental and non-governmental agencies, and environmental companies. While this volume maintains its rigor in terms of its depth of knowledge and quantitative information, it contains the breadth needed for wide variety problems and applications in the environmental sciences. This volume presents all of the newer and older applications of isotopes pertaining to the environmental problems in one place that is readily accessible to readers. This book not only has the depth and rigor that is needed for academia, but it has the breadth and case studies to illustrate the utility of the isotopes in a wide variety of environments (atmosphere, oceans, lakes, rivers and streams, terrestrial environments, and sub-surface environments) and serves a large audience, from students and researchers, regulators in federal, state and local governments, and environmental companies. (orig.)

  8. 钱塘江河口区晚第四纪古环境演化及其元素地球化学特征%PALEOENVIRONMENT EVOLUTION DURING THE LATE QUATERNARY IN THE QIANTANG RIVER MOUTH AREA: EVIDENCE FROM THE SE2 CORE SEDIMENT AND ITS RARE EARTH ELEMENTS GEOCHEMISTRY

    Institute of Scientific and Technical Information of China (English)

    李艳丽; 林春明; 张霞; 周健; 曲长伟; 潘峰; 姚玉来

    2011-01-01

    In 2009, a 51. 5-m-long core SE2 was drilled at 120°21'57" E, 30°12'38" N, from the Kanshan town, Hangzhou city, in the south bank of the Qiantang River. The ground surface elevation of the core is 6. Om above mean sea level. Core SE2,10. 8cm in diameter,was obtained by rotary drilling with a 96% recovery. A total of 294 samples were collected at 10 ~20cm intervals along the cored succession for grain size analysis,93 samples at 20 ~ 80cm intervals for foraminifera identification, and 27 samples at 200cm intervals for rare earth elements analysis. The lithology, grain size, sedimentary structure, foraminifera, and rare earth elements of Late Quaternary sediments in the borehole SE2 were analyzed to research the sedimentary environment evolution, and the associated distribution variation of rare earth elements in the Qiantang River mouth area. The results indicate that five sedimentary facies, including fluvial channel,floodplain,tidal flat,shallow marine,and estuarine sand bar,can be distinguished,and the rare earth elements distribution is closely related to sedimentary environment. Fluvial channel facies consists of sandy gravel,gravelly sand, and fine sand, with high content of rolling and saltation population. Foraminifera are absent. The sediments have the lowest total rare earth elements content in all sedimentary facies,and high light rare earth elements concentration. The fractionation degree of light and heavy rare earth elements, and fractionation degree of heavy rare earth elements are positively related with the total rare earth elements content. The fractionation of light rare earth elements shows negative correlation with the total rare earth elements content, heavy rare earth elements concentration, the fractionation of light and heavy rare earth elements, and fractionation in heavy rare earth elements. Floodplain facies are dominated by clay, with foraminifera and rolling population absent. Total rare earth elements content is the highest. The

  9. Isotope Geochemistry for Comparative Planetology of Exoplanets

    Science.gov (United States)

    Mandt, K. E.; Atreya, S.; Luspay-Kuti, A.; Mousis, O.; Simon, A.; Hofstadter, M. D.

    2017-01-01

    Isotope geochemistry has played a critical role in understanding processes at work in and the history of solar system bodies. Application of these techniques to exoplanets would be revolutionary and would allow comparative planetology with the formation and evolution of exoplanet systems. The roadmap for comparative planetology of the origins and workings of exoplanets involves isotopic geochemistry efforts in three areas: (1) technology development to expand observations of the isotopic composition of solar system bodies and expand observations to isotopic composition of exoplanet atmospheres; (2) theoretical modeling of how isotopes fractionate and the role they play in evolution of exoplanetary systems, atmospheres, surfaces and interiors; and (3) laboratory studies to constrain isotopic fractionation due to processes at work throughout the solar system.

  10. Introduction to geochemistry: principles and applications

    National Research Council Canada - National Science Library

    Misra, Kula C

    2012-01-01

    ...: crystal chemistry, chemical reactions, isotope chemistry, and the Earth supersystem, which includes discussions pertinent to the evolution of the solid Earth, the atmosphere, and the hydrosphere...

  11. [Phosphorus intake and osteoporosis].

    Science.gov (United States)

    Omi, N; Ezawa, I

    2001-10-01

    Phosphorus (P) is one of the most important nutrients for bone metabolism, such as calcium. In general, P intake is usually adequate in our daily diet, and there is a risk of over-consumption from processed food. On the other hand, Ca intake is not always adequate from the Japanese daily diet. When Ca/P is taken from the daily diet at a level of 0.5 - 2.0, the P intake level dose not affect intestinal Ca absorption. Therefore, it is important not only to pay attention to preventing the over-consumption of P, but also to obtain a sufficient intake of Ca. For the prevention of osteoporosis, it is important to consume sufficient Ca and to maintain and appropriate Ca/P balance from diet.

  12. Electric Conductivity of Phosphorus Nanowires

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jing-Xiang; LI Hui; ZHANG Xue-Qing; LIEW Kim-Meow

    2009-01-01

    We present the structures and electrical transport properties of nanowires made from different strands of phosphorus chains encapsulated in carbon nanotubes. Optimized by density function theory, our results indicate that the conductance spectra reveal an oscillation dependence on the size of wires. It can be seen from the density of states and current-voltage curves that the structure of nanowires affects their properties greatly. Among them,the DNA-like double-helical phosphorus nanowire exhibits the distinct characteristic of an approximately linear I - V relationship and has a higher conductance than others. The transport properties of phosphorus nanowires are highly correlated with their microstructures.

  13. Earthing the human body influences physiologic processes.

    Science.gov (United States)

    Sokal, Karol; Sokal, Pawel

    2011-04-01

    This study was designed to answer the question: Does the contact of the human organism with the Earth via a copper conductor affect physiologic processes? Subjects and experiments: Five (5) experiments are presented: experiment 1-effect of earthing on calcium-phosphate homeostasis and serum concentrations of iron (N = 84 participants); experiment 2-effect of earthing on serum concentrations of electrolytes (N = 28); experiment 3-effect of earthing on thyroid function (N = 12); experiment 4-effect of earthing on glucose concentration (N = 12); experiment 5-effect of earthing on immune response to vaccine (N = 32). Subjects were divided into two groups. One (1) group of people was earthed, while the second group remained without contact with the Earth. Blood and urine samples were examined. Earthing of an electrically insulated human organism during night rest causes lowering of serum concentrations of iron, ionized calcium, inorganic phosphorus, and reduction of renal excretion of calcium and phosphorus. Earthing during night rest decreases free tri-iodothyronine and increases free thyroxine and thyroid-stimulating hormone. The continuous earthing of the human body decreases blood glucose in patients with diabetes. Earthing decreases sodium, potassium, magnesium, iron, total protein, and albumin concentrations while the levels of transferrin, ferritin, and globulins α1, α2, β, and γ increase. These results are statistically significant. Earthing the human body influences human physiologic processes. This influence is observed during night relaxation and during physical activity. Effect of the earthing on calcium-phosphate homeostasis is the opposite of that which occurs in states of weightlessness. It also increases the activity of catabolic processes. It may be the primary factor regulating endocrine and nervous systems.

  14. Total Phosphorus in Surface Water

    Data.gov (United States)

    U.S. Environmental Protection Agency — Excess phosphorus in surface water can result in eutrophication. TOTALP is reported in kilograms/hectare/year. More information about these resources, including the...

  15. Dietary phosphorus and kidney disease.

    Science.gov (United States)

    Uribarri, Jaime

    2013-10-01

    High serum phosphate is linked to poor health outcome and mortality in chronic kidney disease (CKD) patients before or after the initiation of dialysis. Therefore, maintenance of normal serum phosphate levels is a major concern in the clinical care of this population with dietary phosphorus restriction and/or use of oral phosphate binders considered to be the best corrective care. This review discusses (1) evidence for an association between serum phosphate levels and bone and cardiovascular disease (CVD) in CKD patients as well as progression of kidney disease itself; (2) the relationship between serum phosphate and dietary phosphorus intake; and (3) implications from these data for future research. Increasing our understanding of the relationship between altered phosphorus metabolism and disease in CKD patients may clarify the potential role of excess dietary phosphorus as a risk factor for disease in the general population.

  16. The influence of geochemistry on health risks to animals and ...

    African Journals Online (AJOL)

    Unknown

    The influence of geochemistry on health risks to animals and humans in ... geochemistry related risk factors, and health implications, within communal livestock production .... to have adverse effects at relatively low levels, and that all trace minerals are toxic if ingested ... and environmental antagonists (altitude, temperature).

  17. Geochemistry of sediments of the eastern continental shelf of India

    Digital Repository Service at National Institute of Oceanography (India)

    Mascarenhas, A; Paropkari, A; Murty, P.S

    The bulk and partition geochemistry of Al, Fe, Ti, Mn, Zn, and Cu have been investigated in sediments of the eastern continental shelf of India. The results show that (1) the bulk geochemistry varies from one shelf unit to the other, (2) all...

  18. Phosphorus balance with daily dialysis.

    Science.gov (United States)

    Kooienga, Laura

    2007-01-01

    Hyperphosphatemia is an almost universal finding in patients with end-stage renal disease and is associated with increased all-cause mortality, cardiovascular mortality, and vascular calcification. These associations have raised the question of whether reducing phosphorus levels could result in improved survival. In light of the recent findings that increased per-session dialysis dose, as assessed by urea kinetics, did not result in improved survival, the definition of adequacy of dialysis should be re-evaluated and consideration given to alternative markers. Two alternatives to conventional thrice weekly dialysis (CHD) are nocturnal hemodialysis (NHD) and short daily hemodialysis (SDHD). The elimination kinetics of phosphorus as they relate to these alternative daily dialysis schedules and the clinical implications of overall phosphorus balance are discussed here. The total weekly phosphorus removal with NHD is more than twice that removed by CHD (4985 mg/week +/- 1827 mg vs. 2347 mg/week +/- 697 mg) and this is associated with a significantly lower average serum phosphorous (4.0 mg/dl vs. 6.5 mg/dl). In spite of the observed increase in protein and phosphorus intake seen in patients on SDHD, phosphate binder requirements and serum phosphorus levels are generally stable to decrease although this effect is strongly dependent on the frequency and overall treatment time.

  19. Hydro-geochemistry and retention of phosphorus in drainage filters and constructed wetlands

    DEFF Research Database (Denmark)

    Canga, Eriona; Kjærgaard, Charlotte; Iversen, Bo Vangsø

    . The project further explores the denitrification capacity and potential green house gas emissions in different types of constructed wetlands and filter solutions. Sensitivity analyses using integrated models will provide filter design parameters for optimized filter performance and allow analysis of cost...... typically applied to point sources. This calls for a shift of paradigm towards the development of new, cost-efficient technologies to mitigate site-specific nutrient losses in drainage. A newly launched Danish research project “SUPREME-TECH” (2010-2015) (www.supreme-tech.dk) funded by the Danish Strategic...... Research Council, aims at providing the scientific basis for developing cost-effective filter technologies targeting P-retention and N-removal in agricultural subsurface drainage. The project studies different approaches of implementing the filter technologies including drainage well filters as well...

  20. Geochemistry@BGS : a guide to geochemical data at the British Geological Survey

    OpenAIRE

    Johnson, C C

    2011-01-01

    This report reviews the main activities in the British Geological Survey (and previously as the Institute of Geological Sciences) that have generated geochemical data. Included are; the mineral reconnaissance programme; regional geochemical mapping; groundwater geochemistry; marine and estuarine surveys; environmental geochemistry and health; radiometric surveys; isotopic geochemistry; lithogeochemical investigations; organic geochemistry laboratories; and many international activities involv...

  1. Expanding earth

    Energy Technology Data Exchange (ETDEWEB)

    Carey, S.W.

    1976-01-01

    Arguments in favor of an expanding earth are presented. The author believes that the theory of plate tectonics is a classic error in the history of geology. The case for the expanding earth is organized in the following way: introductory review - face of the earth, development of expanding earth concept, necessity for expansion, the subduction myth, and definitions; some principles - scale of tectonic phenomena, non-uniformitarianism, tectonic profile, paleomagnetism, asymmetry of the earth, rotation of the earth, and modes of crustal extension; regional studies - western North America, Central America, South-East Asia, and the rift oceans; tests and cause of expansion. 824 references, 197 figures, 11 tables. (RWR)

  2. The Nitrogen Budget of Earth

    CERN Document Server

    Johnson, Ben

    2015-01-01

    We comprehensively compile and review N content in geologic materials to calculate a new N budget for Earth. Using analyses of rocks and minerals in conjunction with N-Ar geochemistry demonstrates that the Bulk Silicate Earth (BSE) contains \\sim7\\pm4 times present atmospheric N (4\\times10^18 kg N, PAN), with 27\\pm16\\times10^18 kg N. Comparison to chondritic composition, after subtracting N sequestered into the core, yields a consistent result, with BSE N between 17\\pm13\\times10^18 kg to 31\\pm24\\times10^18 kg N. In the chondritic comparison we calculate a N mass in Earth's core (180\\pm110 to 300\\pm180\\times10^18 kg) and discuss the Moon as a proxy for the early mantle. Significantly, we find the majority of the planetary budget of N is in the solid Earth. The N estimate herein precludes the need for a "missing N" reservoir. Nitrogen-Ar systematics in mantle rocks and basalts identify two mantle reservoirs: MORB-source like (MSL) and high-N. High-N mantle is composed of young, N-rich material subducted from the...

  3. Statistical geochemistry reveals disruption in secular lithospheric evolution about 2.5 Gyr ago.

    Science.gov (United States)

    Keller, C Brenhin; Schoene, Blair

    2012-05-23

    The Earth has cooled over the past 4.5 billion years (Gyr) as a result of surface heat loss and declining radiogenic heat production. Igneous geochemistry has been used to understand how changing heat flux influenced Archaean geodynamics, but records of systematic geochemical evolution are complicated by heterogeneity of the rock record and uncertainties regarding selection and preservation bias. Here we apply statistical sampling techniques to a geochemical database of about 70,000 samples from the continental igneous rock record to produce a comprehensive record of secular geochemical evolution throughout Earth history. Consistent with secular mantle cooling, compatible and incompatible elements in basalts record gradually decreasing mantle melt fraction through time. Superimposed on this gradual evolution is a pervasive geochemical discontinuity occurring about 2.5 Gyr ago, involving substantial decreases in mantle melt fraction in basalts, and in indicators of deep crustal melting and fractionation, such as Na/K, Eu/Eu* (europium anomaly) and La/Yb ratios in felsic rocks. Along with an increase in preserved crustal thickness across the Archaean/Proterozoic boundary, these data are consistent with a model in which high-degree Archaean mantle melting produced a thick, mafic lower crust and consequent deep crustal delamination and melting--leading to abundant tonalite-trondhjemite-granodiorite magmatism and a thin preserved Archaean crust. The coincidence of the observed changes in geochemistry and crustal thickness with stepwise atmospheric oxidation at the end of the Archaean eon provides a significant temporal link between deep Earth geochemical processes and the rise of atmospheric oxygen on the Earth.

  4. Not So Rare Earth? New Developments in Understanding the Origin of the Earth and Moon

    Science.gov (United States)

    Righter, Kevin

    2007-01-01

    A widely accepted model for the origin of the Earth and Moon has been a somewhat specific giant impact scenario involving an impactor to proto-Earth mass ratio of 3:7, occurring 50-60 Ma after T(sub 0), when the Earth was only half accreted, with the majority of Earth's water then accreted after the main stage of growth, perhaps from comets. There have been many changes to this specific scenario, due to advances in isotopic and trace element geochemistry, more detailed, improved, and realistic giant impact and terrestrial planet accretion modeling, and consideration of terrestrial water sources other than high D/H comets. The current scenario is that the Earth accreted faster and differentiated quickly, the Moon-forming impact could have been mid to late in the accretion process, and water may have been present during accretion. These new developments have broadened the range of conditions required to make an Earth-Moon system, and suggests there may be many new fruitful avenues of research. There are also some classic and unresolved problems such as the significance of the identical O isotopic composition of the Earth and Moon, the depletion of volatiles on the lunar mantle relative to Earth's, the relative contribution of the impactor and proto-Earth to the Moon's mass, and the timing of Earth's possible atmospheric loss relative to the giant impact.

  5. Contaminant geochemistry--a new perspective.

    Science.gov (United States)

    Yaron, Bruno; Dror, Ishai; Berkowitz, Brian

    2010-01-01

    To date, the field of contaminant geochemistry--which deals with the study of chemical interactions in soil and aquifer environments--has focused mainly on pollutant toxicity, retention, persistence, and transport and/or on remediation of contaminated sites. Alteration of subsurface physicochemical properties by anthropogenic chemicals, which reach the land surface as a result of human activity, has been essentially neglected. Contaminant-induced changes in subsurface properties are usually considered as deviations from a normal geological environment, which will disappear under natural attenuation or following remediation procedures. However, contaminants may in many cases cause irreversible changes in both structure and properties of the soil-subsurface geosystem between the land surface and groundwater. The time scales associated with these changes are on a "human time scale", far shorter than geological scales relevant for geochemical processes. In this review, we draw attention to a new perspective of contaminant geochemistry, namely, irreversible changes in the subsurface as a result of anthropogenic chemical pollution. We begin by briefly reviewing processes governing contaminant-subsurface interactions. We then survey how chemical contamination causes irreversible changes in subsurface structure and properties. The magnitude of the anthropogenic impact on the soil and subsurface is linked directly to the amounts of chemical contaminants applied and/or disposed of on the land surface. This particular aspect is of major importance when examining the effects of humans on global environmental changes. Consideration of these phenomena opens new perspectives for the field of contaminant geochemistry and for research of human impacts on the soil and subsurface regimes.

  6. The Relevance of Phosphorus and Iron Chemistry to the Recovery of Phosphorus from Wastewater: A Review.

    Science.gov (United States)

    Wilfert, Philipp; Kumar, Prashanth Suresh; Korving, Leon; Witkamp, Geert-Jan; van Loosdrecht, Mark C M

    2015-08-18

    The addition of iron is a convenient way for removing phosphorus from wastewater, but this is often considered to limit phosphorus recovery. Struvite precipitation is currently used to recover phosphorus, and this approach has attracted much interest. However, it requires the use of enhanced biological phosphorus removal (EBPR). EBPR is not yet widely applied and the recovery potential is low. Other phosphorus recovery methods, including sludge application to agricultural land or recovering phosphorus from sludge ash, also have limitations. Energy-producing wastewater treatment plants increasingly rely on phosphorus removal using iron, but the problem (as in current processes) is the subsequent recovery of phosphorus from the iron. In contrast, phosphorus is efficiently mobilized from iron by natural processes in sediments and soils. Iron-phosphorus chemistry is diverse, and many parameters influence the binding and release of phosphorus, including redox conditions, pH, presence of organic substances, and particle morphology. We suggest that the current poor understanding of iron and phosphorus chemistry in wastewater systems is preventing processes being developed to recover phosphorus from iron-phosphorus rich wastes like municipal wastewater sludge. Parameters that affect phosphorus recovery are reviewed here, and methods are suggested for manipulating iron-phosphorus chemistry in wastewater treatment processes to allow phosphorus to be recovered.

  7. Earth Sciences report, 1989--1990

    Energy Technology Data Exchange (ETDEWEB)

    Younker, L.W.; Peterson, S.J.; Price, M.E. (eds.)

    1991-03-01

    The Earth Sciences Department at Lawrence Livermore National Laboratory (LLNL) conducts work in support of the Laboratory's energy, defense, environmental, and basic research programs. The Department comprises more than 100 professional scientific personnel spanning a variety of subdisciplines: geology, seismology, physics, geophysics, geochemistry, geohydrology, chemical engineering, and mechanical engineering. Resident technical support groups add significant additional technical expertise, including Containment Engineering, Computations, Electronic Engineering, Mechanical Engineering, Chemistry and Materials Science, and Technical Information. In total, approximately 180 professional scientists and engineers are housed in the Earth Sciences Department, making it one of the largest geo-science research groups in the nation. Previous Earth Sciences reports have presented an outline of the technical capabilities and accomplishments of the groups within the Department. In this FY 89/90 Report, we have chosen instead to present twelve of our projects in full-length technical articles. This Overview introduces those articles and highlights other significant research performed during this period.

  8. Speciation of phosphorus in the continental shelf sediments in the Eastern Arabian Sea

    Science.gov (United States)

    Acharya, Shiba Shankar; Panigrahi, Mruganka Kumar; Kurian, John; Gupta, Anil Kumar; Tripathy, Subhasish

    2016-03-01

    The distributions of various forms of phosphorus (P) and their relation with sediment geochemistry in two core sediments near Karwar and Mangalore offshore have been studied through the modified SEDEX procedure (Ruttenberg et al., 2009) and bulk chemical analysis. The present study provides the first quantitative analysis of complete phosphorus speciation in the core sediments of the Eastern Arabian shelf. The chemical index of alteration (CIA), chemical Index of Weathering (CIW) and Al-Ti-Zr ternary diagram suggest low to moderate source area weathering of granodioritic to tonalitic source rock composition, despite the intense orographic rainfall in the source area. Due to the presence of same source rock and identical oxic depositional environment, the studied sediments show the same range of variation of total phosphorus (24 to 83 μmol/g) with a down-depth depleting trend. Organic bound P and detrital P are the two major chemical forms followed by iron-bound P, exchangeable/loosely bound P and authigenic P. The authigenic P content in the sediments near Mangalore coast varies linearly with calcium (r=0.88) unlike that of Karwar coast. The different reactive-phosphorus pools exhibit identical depleting trend with depth. This indicates that the phosphorus released from the organic matter and Fe bound fractions are prevented from precipitating as authigenic phosphates in the deeper parts of the sediment column. The low concentration of total P, dominance of detrital non-reactive fraction of P and inhibition of formation of authigenic phosphate result in the absence of active phosphatization in the Eastern Arabian Shelf in the studied region. High sedimentation rate (35-58 cm/kyr) and absence of winnowing effect appear to be the dominant factor controlling the P-speciation in the studied sediments.

  9. Geochemistry of apollo 15 basalt 15555 and soil 15531.

    Science.gov (United States)

    Schnetzler, C C; Philpotts, J A; Nava, D F; Schuhmann, S; Thomas, H H

    1972-01-28

    Major and trace element concentrations have been determined by atomic absorption spectrophotometry, colorimetry, and isotope dilution in Apollo 15 mare basalt 15555 from the Hadley Rille area; trace element concentrations have also been determined in plagioclase and pyroxene separates from basalt 15555 and in soil 15531 from the same area. Basalt 15555 most closely resembles in composition the Apollo 12 olivine-rich basalts. The concentrations of lithium, potassium, rubidium, barium, rare-earth elements, and zirconium in basalt 15555 are the lowest, and the negative europium anomaly is the smallest, reported for lunar basalts; this basalt might be the least differentiated material yet returned from the moon. Crystallization and removal of about 6 percent of plagioclase similar to that contained in the basalt would account for the observed europium anomaly; if plagioclase is not on the liquidus of this basalt, a multistage origin is indicated. Mineral data indicate that plagioclase and pyroxene approached quasi-equilibrium. Most of the chemical differences between basalt 15555 and soil 15531 would be accounted for if the soil were a mixture of 88 percent basalt, 6 percent KREEP (a component, identified in other Apollo soils, rich in potassium, rare-earth elements, and phosphorus) and 6 percent plagioclase (anorthosite?).

  10. Natural Phosphorus Sources for the Pacific Northwest

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Phosphorus is a naturally occurring element found in all rocks; the amount varies by the type of rock. The amount of phosphorus in sediments is expected to be...

  11. Economic feasibility study for phosphorus recovery processes.

    Science.gov (United States)

    Molinos-Senante, María; Hernández-Sancho, Francesc; Sala-Garrido, Ramón; Garrido-Baserba, Manel

    2011-06-01

    Phosphorus recovery from wastewater has become a necessity for sustainable development because phosphorus is a non-renewable essential resource, and its discharge into the environment causes serious negative impacts. There are no economic incentives for the implementation of phosphorus recovery technologies because the selling price of rock phosphate is lower than phosphorus recovered from sewage. The methodologies used to determine the feasibility of such projects are usually focused on internal costs without considering environmental externalities. This article shows a methodology to assess the economic feasibility of wastewater phosphorus recovery projects that takes into account internal and external impacts. The shadow price of phosphorus is estimated using the directional distance function to measure the environmental benefits obtained by preventing the discharge of phosphorus into the environment. The economic feasibility analysis taking into account the environmental benefits shows that the phosphorus recovery is viable not only from sustainable development but also from an economic point of view.

  12. Edge phonons in black phosphorus

    Science.gov (United States)

    Ribeiro, H. B.; Villegas, C. E. P.; Bahamon, D. A.; Muraca, D.; Castro Neto, A. H.; de Souza, E. A. T.; Rocha, A. R.; Pimenta, M. A.; de Matos, C. J. S.

    2016-07-01

    Black phosphorus has recently emerged as a new layered crystal that, due to its peculiar and anisotropic crystalline and electronic band structures, may have important applications in electronics, optoelectronics and photonics. Despite the fact that the edges of layered crystals host a range of singular properties whose characterization and exploitation are of utmost importance for device development, the edges of black phosphorus remain poorly characterized. In this work, the atomic structure and behaviour of phonons near different black phosphorus edges are experimentally and theoretically studied using Raman spectroscopy and density functional theory calculations. Polarized Raman results show the appearance of new modes at the edges of the sample, and their spectra depend on the atomic structure of the edges (zigzag or armchair). Theoretical simulations confirm that the new modes are due to edge phonon states that are forbidden in the bulk, and originated from the lattice termination rearrangements.

  13. Phosphorus Flamethrower: A Demonstration Using Red and White Allotropes of Phosphorus

    Science.gov (United States)

    Golden, Melissa L.; Person, Eric C.; Bejar, Miriam; Golden, Donnie R.; Powell, Jonathan M.

    2010-01-01

    A demonstration was created to display the unique behavior of a familiar element, phosphorus, and to make chemistry more accessible to the introductory student. The common allotropes of phosphorus and their reactivity are discussed. In this demonstration, the white allotrope of phosphorus is synthesized from the red phosphorus obtained from a…

  14. New visiting scientists in NSF's Earth sciences

    Science.gov (United States)

    MacGregor, Ian

    The National Science Foundation's Division of Earth Sciences has hired two new rotators to serve as program directors, as part of the ongoing visiting scientists program. The new directors are Jonathan Fink in Geochemistry and Petrology, and L. Douglas James in Hydrological Sciences.Fink has exchanged roles for 1 year with NSF's John Snyder, who is on sabbatical at Arizona State University. Fink's current research includes studies of how the Theological properties of magma govern the emplacement of volcanic domes and lava flows, and the gravitational control on their mass movements. This research extends to the mechanisms of igneous intrusion and interpretation of volcanic features in extraterrestrial and submarine environments.

  15. Evolution of the global phosphorus cycle

    OpenAIRE

    Reinhard, Christopher T.; Noah J. Planavsky; Gill, Benjamin C.; Ozaki, Kazumi; Robbins, Leslie J.; Lyons, Timothy W.; Fischer, Woodward W.; Wang, Chunjiang; Cole, Devon B.; Konhauser, Kurt O.

    2016-01-01

    The macronutrient phosphorus is thought to limit primary productivity in the oceans on geological timescales. Although there has been a sustained effort to reconstruct the dynamics of the phosphorus cycle over the past 3.5 billion years, it remains uncertain whether phosphorus limitation persisted throughout Earth’s history and therefore whether the phosphorus cycle has consistently modulated biospheric productivity and ocean–atmosphere oxygen levels over time. Here we present a compilation o...

  16. Theory of Earth

    Science.gov (United States)

    Anderson, D. L.

    2014-12-01

    Earth is an isolated, cooling planet that obeys the 2nd law. Interior dynamics is driven from the top, by cold sinking slabs. High-resolution broad-band seismology and geodesy has confirmed that mantle flow is characterized by narrow downwellings and ~20 broad slowly rising updrafts. The low-velocity zone (LVZ) consists of a hot melange of sheared peridotite intruded with aligned melt-rich lamellae that are tapped by intraplate volcanoes. The high temperature is a simple consequence of the thermal overshoot common in large bodies of convecting fluids. The transition zone consists of ancient eclogite layers that are displaced upwards by slabs to become broad passive, and cool, ridge feeding updrafts of ambient mantle. The physics that is overlooked in canonical models of mantle dynamics and geochemistry includes; the 2nd law, convective overshoots, subadiabaticity, wave-melt interactions, Archimedes' principle, and kinetics (rapid transitions allow stress-waves to interact with melting and phase changes, creating LVZs; sluggish transitions in cold slabs keep eclogite in the TZ where it warms up by extracting heat from mantle below 650 km, creating the appearance of slab penetration). Canonical chemical geodynamic models are the exact opposite of physics and thermodynamic based models and of the real Earth. A model that results from inverting the assumptions regarding initial and boundary conditions (hot origin, secular cooling, no external power sources, cooling internal boundaries, broad passive upwellings, adiabaticity and whole-mantle convection not imposed, layering and self-organization allowed) results in a thick refractory-yet-fertile surface layer, with ancient xenoliths and cratons at the top and a hot overshoot at the base, and a thin mobile D" layer that is an unlikely plume generation zone. Accounting for the physics that is overlooked, or violated (2nd law), in canonical models, plus modern seismology, undermines the assumptions and conclusions of these

  17. Magma genesis, plate tectonics, and chemical differentiation of the Earth

    OpenAIRE

    Wyllie, Peter J.

    1988-01-01

    Magma genesis, migration, and eruption have played prominent roles in the chemical differentiation of the Earth. Plate tectonics has provided the framework of tectonic environments for different suites of igneous rocks and the dynamic mechanisms for moving masses of rock into melting regions. Petrology is rooted in geophysics. Petrological and geophysical processes are calibrated by the phase equilibria of the materials. The geochemistry of basalts and mantle xenoliths demonstrates that the m...

  18. Phosphorus depletion in forest soils shapes bacterial communities towards phosphorus recycling systems.

    Science.gov (United States)

    Bergkemper, Fabian; Schöler, Anne; Engel, Marion; Lang, Friederike; Krüger, Jaane; Schloter, Michael; Schulz, Stefanie

    2016-06-01

    Phosphorus (P) is an important macronutrient for all biota on earth but similarly a finite resource. Microorganisms play on both sides of the fence as they effectively mineralize organic and solubilize precipitated forms of soil phosphorus but conversely also take up and immobilize P. Therefore, we analysed the role of microbes in two beech forest soils with high and low P content by direct sequencing of metagenomic deoxyribonucleic acid. For inorganic P solubilization, a significantly higher microbial potential was detected in the P-rich soil. This trait especially referred to Candidatus Solibacter usiatus, likewise one of the dominating species in the data sets. A higher microbial potential for efficient phosphate uptake systems (pstSCAB) was detected in the P-depleted soil. Genes involved in P starvation response regulation (phoB, phoR) were prevalent in both soils. This underlines the importance of effective phosphate (Pho) regulon control for microorganisms to use alternative P sources during phosphate limitation. Predicted genes were primarily harboured by Rhizobiales, Actinomycetales and Acidobacteriales.

  19. A CONTRIBUTION TO THE RESEARCH ON RARE EARTH ELEMENTS IN SEDIMENTARY ROCKS

    Directory of Open Access Journals (Sweden)

    Josip Crnički

    1989-12-01

    Full Text Available The main features of the geochemistry of rare earth elements (REE, REE mineralogy and the REE i contents and distributions in sedimentary rocks are presented. A new classification of REE minerals as well as a new systematic order of the REE behaviour in sedimentology is introduced and explained.

  20. Guiding phosphorus stewardship for multiple ecosystem services

    Science.gov (United States)

    Phosphorus is vital to agricultural production and water quality regulation. While the role of phosphorus in agriculture and water quality has been studied for decades, the benefits of sustainable phosphorus use and management for society due to its downstream impacts on multiple ecosystem services...

  1. REE geochemistry of 3.2 Ga BIF from the Mapepe Formation, Barberton Greenstone Belt, South Africa

    Science.gov (United States)

    Yahagi, T. R.; Yamaguchi, K. E.; Haraguchi, S.; Sano, R.; Teraji, S.; Kiyokawa, S.; Ikehara, M.; Ito, T.

    2012-12-01

    Banded iron formations (BIFs) are chemical sediments interbedded with Fe- and Si-rich layers, characteristically present in the early history of the Earth. A popular hypothesis for the formation of BIFs postulates that dissolved oxygen produced by photosynthesizers such as cyanobacteria oxidized dissolved ferrous Fe supplied by submarine hydrothermal activities. During precipitation of Fe-oxide minerals, phosphorus and rare earth elements (REEs) were most likely adsorbed on their surface. Therefore, chemical compositions of REEs that adsorbed onto Fe-oxide have useful information on the seawater chemistry at the time of deposition. Especially, information on the redox state of seawater and the extent of the contribution of hydrothermal activity during BIF deposition are expected to have been recorded. Occurrence of BIF has been traditionally tied to the chemical evolution of the atmosphere. Rise of atmospheric oxygen, or as known as GOE (Great Oxidation Event: e.g., Holland, 1994), has been widely believed to have occurred at around 2.4 Ga ago. Contrary, however, some studies have suggested that such oxygenation could have occurred much earlier (e.g., Hoashi et al., 2009). In this study, we used 3.2 Ga old BIF from the Mapepe Formation at the bottom of the Fig Tree Group of the Swaziland Supergroup in the northeastern part of the Barberton Greenstone Belt, South Africa. We aimed to constrain the marine environment, and by inference atmospheric environment, at the time of BIF deposition from REE geochemistry. Major elements and REE compositions of 37 samples were measured using XRF and ICP-MS, respectively. Samples with less than 1.0 wt% Al2O3 are considered to be "pure" BIFs with minimal amount of continental contamination, and are expected to have inherited marine REE signatures. Abundance of REE normalized by C1 chondrite for the analyzed samples commonly exhibits positive Eu anomaly and LREE

  2. Marine geochemistry ocean circulation, carbon cycle and climate change

    CERN Document Server

    Roy-Barman, Matthieu

    2016-01-01

    Marine geochemistry uses chemical elements and their isotopes to study how the ocean works. It brings quantitative answers to questions such as: What is the deep ocean mixing rate? How much atmospheric CO2 is pumped by the ocean? How fast are pollutants removed from the ocean? How do ecosystems react to the anthropogenic pressure? The book provides a simple introduction to the concepts (environmental chemistry, isotopes), the methods (field approach, remote sensing, modeling) and the applications (ocean circulation, carbon cycle, climate change) of marine geochemistry with a particular emphasis on isotopic tracers. Marine geochemistry is not an isolated discipline: numerous openings on physical oceanography, marine biology, climatology, geology, pollutions and ecology are proposed and provide a global vision of the ocean. It includes new topics based on ongoing research programs such as GEOTRACES, Global Carbon Project, Tara Ocean. It provides a complete outline for a course in marine geochemistry. To favor a...

  3. 40 CFR 422.20 - Applicability; description of the phosphorus consuming subcategory.

    Science.gov (United States)

    2010-07-01

    ... phosphorus consuming subcategory. 422.20 Section 422.20 Protection of Environment ENVIRONMENTAL PROTECTION... Phosphorus Consuming Subcategory § 422.20 Applicability; description of the phosphorus consuming subcategory... manufacture of phosphoric acid, phosphorus pentoxide, phosphorus pentasulfide, phosphorus trichloride,...

  4. Computational Studies in Molecular Geochemistry and Biogeochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Felmy, Andrew R.; Bylaska, Eric J.; Dixon, David A.; Dupuis, Michel; Halley, James W.; Kawai, R.; Rosso, Kevin M.; Rustad, James R.; Smith, Paul E.; Straatsma, TP; Voth, Gregory A.; Weare, John H.; Yuen, David A.

    2006-04-18

    The ability to predict the transport and transformations of contaminants within the subsurface is critical for decisions on virtually every waste disposal option facing the Department of Energy (DOE), from remediation technologies such as in situ bioremediation to evaluations of the safety of nuclear waste repositories. With this fact in mind, the DOE has recently sponsored a series of workshops on the development of a Strategic Simulation Plan on applications of high perform-ance computing to national problems of significance to the DOE. One of the areas selected for application was in the area of subsurface transport and environmental chemistry. Within the SSP on subsurface transport and environmental chemistry several areas were identified where applications of high performance computing could potentially significantly advance our knowledge of contaminant fate and transport. Within each of these areas molecular level simulations were specifically identified as a key capability necessary for the development of a fundamental mechanistic understanding of complex biogeochemical processes. This effort consists of a series of specific molecular level simulations and program development in four key areas of geochemistry/biogeochemistry (i.e., aqueous hydrolysis, redox chemistry, mineral surface interactions, and microbial surface properties). By addressing these four differ-ent, but computationally related, areas it becomes possible to assemble a team of investigators with the necessary expertise in high performance computing, molecular simulation, and geochemistry/biogeochemistry to make significant progress in each area. The specific targeted geochemical/biogeochemical issues include: Microbial surface mediated processes: the effects of lipopolysacchardies present on gram-negative bacteria. Environmental redox chemistry: Dechlorination pathways of carbon tetrachloride and other polychlorinated compounds in the subsurface. Mineral surface interactions: Describing

  5. Greening the global phosphorus cycle

    NARCIS (Netherlands)

    Withers, Paul J.A.; Elser, James J.; Hilton, Julian; Ohtake, Hisao; Schipper, Willem J.; Dijk, Van Kimo C.

    2015-01-01

    The sustainability of global phosphorus (P) use is emerging as a major societal goal to secure future food, energy, and water security for a growing population. Phosphate rock (PR) is a critical raw material whose inefficiency of use is leading to widespread eutrophication and uncertainties about

  6. Natural phosphorus sources for the Pacific Northwest

    Science.gov (United States)

    Johnson, Hank

    2011-01-01

    Phosphorus is a naturally occurring element found in all rocks; the amount varies by the type of rock. The amount of phosphorus in sediments is expected to be correlated with the amount of phosphorus in the parent rocks. Streambed sediment collected by the National Uranium Resource Evaluation (NURE) Program were used to estimate the variation of phosphorus across the Pacific Northwest. This file provides an estimate of the mean concentration of phosphorus in soils for each incremental catchment of the USGS Pacific Northwest SPARROW model.

  7. Environmental Phosphorus Recovery Based on Molecular Bioscavengers

    DEFF Research Database (Denmark)

    Gruber, Mathias Felix

    Phosphorus is a ubiquitous element of all known life and as such it is found throughout numerous key molecules related to various cellular functions. The supply of phosphorus is tightly linked to global food security, since phosphorus is used to produce agricultural fertilizers, without which...... it would not be possible to feed the world population. Sadly, the current supply of phosphorus is based on the gradual depletion of limited fossil reserves, and some estimates predict that within 15-25 years we will consume more phosphorus than we can produce. There is therefore a strong international...

  8. Geology, geochemistry and geochronology of the Songwe Hill carbonatite, Malawi

    Science.gov (United States)

    Broom-Fendley, Sam; Brady, Aoife E.; Horstwood, Matthew S. A.; Woolley, Alan R.; Mtegha, James; Wall, Frances; Dawes, Will; Gunn, Gus

    2017-10-01

    Songwe Hill, Malawi, is one of the least studied carbonatites but has now become particularly important as it hosts a relatively large rare earth deposit. The results of new mapping, petrography, geochemistry and geochronology indicate that the 0.8 km diameter Songwe Hill is distinct from the other Chilwa Alkaline Province carbonatites in that it intruded the side of the much larger (4 × 6 km) and slightly older (134.6 ± 4.4 Ma) Mauze nepheline syenite and then evolved through three different carbonatite compositions (C1-C3). Early C1 carbonatite is scarce and is composed of medium-coarse-grained calcite carbonatite containing zircons with a U-Pb age of 132.9 ± 6.7 Ma. It is similar to magmatic carbonatite in other carbonatite complexes at Chilwa Island and Tundulu in the Chilwa Alkaline Province and others worldwide. The fine-grained calcite carbonatite (C2) is the most abundant stage at Songwe Hill, followed by a more REE- and Sr-rich ferroan calcite carbonatite (C3). Both stages C2 and C3 display evidence of extensive (carbo)-hydrothermal overprinting that has produced apatite enriched in HREE (<2000 ppm Y) and, in C3, synchysite-(Ce). The final stages comprise HREE-rich apatite fluorite veins and Mn-Fe-rich veins. Widespread brecciation and incorporation of fenite into carbonatite, brittle fracturing, rounded clasts and a fenite carapace at the top of the hill indicate a shallow level of emplacement into the crust. This shallow intrusion level acted as a reservoir for multiple stages of carbonatite-derived fluid and HREE-enriched apatite mineralisation as well as LREE-enriched synchysite-(Ce). The close proximity and similar age of the large Mauze nepheline syenite suggests it may have acted as a heat source driving a hydrothermal system that has differentiated Songwe Hill from other Chilwa carbonatites.

  9. Carbon isotope geochemistry of the Santa Clara River

    Science.gov (United States)

    Masiello, Caroline A.; Druffel, Ellen R. M.

    2001-06-01

    The Santa Clara River is a prototypical small mountainous river, with a headwater height greater than 1000 m and a basin area smaller than 10,000 m 2. Although individual small mountainous rivers export trivial amounts of sediment and carbon to the ocean, as a group these rivers may export a major fraction (as much as 50%) of the total global river sediment flux [Milliman and Syvitski, 1992], making their geochemistry relevant the study of the ocean's carbon cycle. In addition, many small rivers export sediment in a few high flux events, causing massive, sporadic discharge of carbon onto coastal shelves, discharge conditions very different from those of large rivers. This class of rivers is an end-member of the river-ocean carbon exchange system,. opposite the Earth's largest river, the Amazon. The carbon mass and isotopic properties of the Santa Clara River are significantly different from previously studied large rivers. During the 1997-1998 winter, all Santa Clara carbon pools were old, with flux-weighted average Δl4C values of-428±76‰ for particulate organic carbon, -73±31‰ for dissolved organic carbon, and-644±58‰ for black carbon. The age of exported carbon is primarily due to the deep erosion of old soils and not to inclusion of fossil fuel carbon. Additionally, the δ13C signatures of exported carbon pools were high relative to terrestrial carbon, bearing a signature quite similar to marine carbon (average particulate organic carbon (POC) δ13C = -22.2±0.8‰). The Santa Clara's estuary is small and drains onto the narrow eastern Pacific coastal margin, exporting this old soil organic matter directly into the ocean. If the Santa Clara export patterns are representative of this class of rivers, they may be a significant source of refractory terrestrial carbon to the ocean.

  10. Aqueous Geochemistry at High Pressures and High Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Bass, Jay D. [Univ. of Illinois, Urbana-Champaign, IL (United States)

    2015-05-21

    This project is aimed at experimental characterization of the sound velocities, equations of state (EOS), and derived physical and chemical properties of aqueous solutions and carbon dioxide at extreme pressure and temperature conditions relevant to processes occurring in the interior of the Earth. Chemical transport, phase changes (including melting), fluid-solid reactions, and formation of magmatic liquids at convergent plat boundaries are a key motivation for this project. Research in this area has long been limited by the extreme experimental challenges and lack of data under the appropriate pressure-temperature (P-T) conditions. The vast majority of studies of aqueous geochemistry relevant to terrestrial problems of fluid-rock interactions have been conducted at 0.3 GPa or less, and the widely used Helgeson-Kirkham-Flowers equation of state for aqueous species is applicable only at ~ < 0.5 GPa. These limits are unfortunate because fluid flow and reactions plays a central role in many deeper environments. Recent efforts including our own, have resulted in new experimental techniques that now make it possible to investigate properties of homogeneous and heterogeneous equilibria involving aqueous species and minerals over a much broader range of pressure and temperature appropriate for deep crustal and upper mantle processes involving water-rich fluids. We carried out 1) Brillouin scattering measurements of the equations of state and molar volume of water and carbon dioxide to over 10 GPa and 870K using precise resistance heating of samples under pressure in the diamond anvil cell, and 2) the phase diagrams of the water and CO2, and 3) Exploring new experimental approaches, including CO2 laser heating of samples in a diamond cell, to measurements of sound velocities, EOS, and phase relations by Brillouin scattering to far greater pressures and temperatures.

  11. Ocean productivity before about 1.9 Gyr ago limited by phosphorus adsorption onto iron oxides.

    Science.gov (United States)

    Bjerrum, Christian J; Canfield, Donald E

    2002-05-09

    After the evolution of oxygen-producing cyanobacteria at some time before 2.7 billion years ago, oxygen production on Earth is thought to have depended on the availability of nutrients in the oceans, such as phosphorus (in the form of orthophosphate). In the modern oceans, a significant removal pathway for phosphorus occurs by way of its adsorption onto iron oxide deposits. Such deposits were thought to be more abundant in the past when, under low sulphate conditions, the formation of large amounts of iron oxides resulted in the deposition of banded iron formations. Under these circumstances, phosphorus removal by iron oxide adsorption could have been enhanced. Here we analyse the phosphorus and iron content of banded iron formations to show that ocean orthophosphate concentrations from 3.2 to 1.9 billion years ago (during the Archaean and early Proterozoic eras) were probably only approximately 10-25% of present-day concentrations. We suggest therefore that low phosphorus availability should have significantly reduced rates of photosynthesis and carbon burial, thereby reducing the long-term oxygen production on the early Earth--as previously speculated--and contributing to the low concentrations of atmospheric oxygen during the late Archaean and early Proterozoic.

  12. Earth\\'s Mass Variability

    CERN Document Server

    Mawad, Ramy

    2014-01-01

    The perturbation of the Earth caused by variability of mass of Earth as additional reason with gravity of celestial bodies and shape of the Earth. The Earth eating and collecting matters from space and loss or eject matters to space through its flying in the space around the Sun. The source of the rising in the global sea level is not closed in global warming and icebergs, but the outer space is the additional important source for this rising. The Earth eats waters from space in unknown mechanism. The mass of the Earth become greater in November i.e. before transit apoapsis two months, and become latter in February i.e. after transit apoapsis to two months.

  13. Geochemistry of Los Humeros Caldera, Puebla, Mexico

    Science.gov (United States)

    Verma, S. P.; Lopez, M.

    1982-03-01

    Geochemistry of Pliocene to recent volcanic rocks from Los Humeros caldera (19°30' N - 19°50' N and 97°15° W - 97°35' W) in East-Central mexico is described. The volcanic rocks from this area seem to represent both alkali and high-alumina basalt series, or both calcalkaline and high-K calc-alkaline sequences. The available bulk-chemical analyses (23 this study and 18 from unpublished literature) show that the entire sequence of rocks from basalts to rhyolites are present in this area. Different degrees of partial melting of the source region followed by extensive shallow-level crystal differentiation seem to have taken place before most volcanic eruptions. These processes are perhaps the most important mechanisms for magma genesis in Los Humeros caldera. Geophysical studies in this area are not sufficient and more detailed geophysical surveys and a better geological interpretation are needed in order to delimit the underlying magma chamber.

  14. Microbial Sulfur Geochemistry in Mine Systems (Invited)

    Science.gov (United States)

    Warren, L. A.; Norlund, K. L.; Hitchcock, A.

    2010-12-01

    Acid mine drainage (AMD), metal laden, acidic water, is the most pressing mining environmental issue on a global scale. While it is well recognized that the activity of autotrophic Fe and S bacteria amplify the oxidation of the sulfidic wastes, thereby generating acidity and leaching metals; the underlying microbial geochemistry is not well described. This talk will highlight results revealing the importance of microbial cooperation associated with a novel sulfur-metabolizing consortium enriched from mine waters. Results generated by an integrated approach, combining field characterization, geochemical experimentation, scanning transmission X-ray microscopy (STXM), and fluorescence in situ hybridization (FISH) [1]describing the underlying ecological drivers, the functionally relevant biogeochemical architecture of the consortial macrostructure as well as the identities of this environmental sulphur redox cycling consortium will be presented. The two common mine bacterial strains involved in this consortium, Acidithiobacillus ferroxidans and Acidiphilium sp., are specifically spatially segregated within a macrostructure (pod) of extracellular polymeric substance (EPS) that enables coupled sulphur oxidation and reduction reactions despite bulk, oxygenated conditions. Identical pod formation by type culture strains was induced and linked to ecological conditions. The proposed sulphur geochemistry associated with this bacterial consortium produces 40-90% less acid than expected based on abiotic AMD models, with implications for both AMD mitigation and AMD carbon flux modeling. We are currently investigating the implications of these sulphur-processing pods for metal dynamics in mine systems. These results demonstrate how microbes can orchestrate their geochemical environment to facilitate metabolism, and underscore the need to consider microbial interactions and ecology in constraining their geochemical impacts. [1] Norlund, Southam, Tyliszcczak, Hu, Karunakaran, Obst

  15. Data-driven Science in Geochemistry & Petrology: Vision & Reality

    Science.gov (United States)

    Lehnert, K. A.; Ghiorso, M. S.; Spear, F. S.

    2013-12-01

    measurements, experiments, and models, both from past and from present studies, and their poor discoverability, interoperability, and standardization. Other deficiencies include the lack of widespread sample curation and online sample catalogs, and broad community support and enforcement of open data sharing policies and a strategy for sustained funding and operation of the cyberinfrastructure. In order to achieve true data-driven science in geochemistry and petrology, one of the primary requirements is to change the way data and models are managed and shared to dramatically improve their access and re-usability. Adoption of new data publication practices, new ways of citing data that ensure attribution and credit to authors, tools that help investigators to seamlessly manage their data throughout the data life cycle, from the point of acquisition to upload to repositories, and population of databases with historical data are among the most urgent needs. The community, especially early career scientists, must work together to produce the cultural shift within the discipline toward sharing of data and knowledge, virtual collaboration, and social networking. Dziewonski, A M, & Anderson, D L: Physics of the Earth and Planet Interiors 25 (4), 297 (1981) Hey, T, Tansley, S, Tolle, K (Eds.): Redmond, VA: Microsoft Research (2009) Zindler, A, & Hart, S R: Ann. Rev. Earth Plan. Sci. 14, 493 (1986)

  16. Geochemistry of zinc in the sediments of the western continental shelf and slope of India

    Digital Repository Service at National Institute of Oceanography (India)

    Murty, P.S.N.; Paropkari, A.L.; Rao, Ch.M.

    The bulk geochemistry of zinc in the sediments of the western continental shelf and slope of India and also the partition geochemistry of the sediments of the shelf and slope regions between Ratnagiri and Mangalore have been studied. The studies...

  17. Phosphorus Recovery from Ashes of Sewage Sludge

    Energy Technology Data Exchange (ETDEWEB)

    Cornel, Peter; Schaum, Peter

    2003-07-01

    About 90% of the incoming phosphorus load of waste water is eliminated by waste water treatment and transferred into the sewage sludge. Considerable amounts of sewage sludge can not be used agriculturally but are incinerated. Thus the ash from mono sludge incineration plants contains significant amounts of phosphorus (up to 25% P{sub 2}O{sub 5}) and could be used as raw material in fertilizer industry. The ash is hygienically harmless and free of organic substances. The ratio of phosphorus to heavy metals is basically the same as in the sewage sludge. The first step in separating phosphorus from heavy metals is to dissolve phosphorus by extraction. The most promising way seems to be the release of phosphorus with acids or bases. With 1 m sulphuric acid it is possible to release phosphorus completely. By use of acid most of the heavy metals dissolve, too. With caustic soda as solvent, only 30-40% of the phosphorus can be dissolved but the eluate is almost free of heavy metals. The amount of phosphorus which can be released with caustic soda, depends on the applied precipitant (Al or Fe salts) for phosphorus elimination at the waste water treatment. (author)

  18. Dietary phosphorus acutely impairs endothelial function.

    Science.gov (United States)

    Shuto, Emi; Taketani, Yutaka; Tanaka, Rieko; Harada, Nagakatsu; Isshiki, Masashi; Sato, Minako; Nashiki, Kunitaka; Amo, Kikuko; Yamamoto, Hironori; Higashi, Yukihito; Nakaya, Yutaka; Takeda, Eiji

    2009-07-01

    Excessive dietary phosphorus may increase cardiovascular risk in healthy individuals as well as in patients with chronic kidney disease, but the mechanisms underlying this risk are not completely understood. To determine whether postprandial hyperphosphatemia may promote endothelial dysfunction, we investigated the acute effect of phosphorus loading on endothelial function in vitro and in vivo. Exposing bovine aortic endothelial cells to a phosphorus load increased production of reactive oxygen species, which depended on phosphorus influx via sodium-dependent phosphate transporters, and decreased nitric oxide production via inhibitory phosphorylation of endothelial nitric oxide synthase. Phosphorus loading inhibited endothelium-dependent vasodilation of rat aortic rings. In 11 healthy men, we alternately served meals containing 400 mg or 1200 mg of phosphorus in a double-blind crossover study and measured flow-mediated dilation of the brachial artery before and 2 h after the meals. The high dietary phosphorus load increased serum phosphorus at 2 h and significantly decreased flow-mediated dilation. Flow-mediated dilation correlated inversely with serum phosphorus. Taken together, these findings suggest that endothelial dysfunction mediated by acute postprandial hyperphosphatemia may contribute to the relationship between serum phosphorus level and the risk for cardiovascular morbidity and mortality.

  19. Phosphorus doping a semiconductor particle

    Science.gov (United States)

    Stevens, G.D.; Reynolds, J.S.

    1999-07-20

    A method of phosphorus doping a semiconductor particle using ammonium phosphate is disclosed. A p-doped silicon sphere is mixed with a diluted solution of ammonium phosphate having a predetermined concentration. These spheres are dried with the phosphorus then being diffused into the sphere to create either a shallow or deep p-n junction. A good PSG glass layer is formed on the surface of the sphere during the diffusion process. A subsequent segregation anneal process is utilized to strip metal impurities from near the p-n junction into the glass layer. A subsequent HF strip procedure is then utilized to removed the PSG layer. Ammonium phosphate is not a restricted chemical, is inexpensive, and does not pose any special shipping, handling, or disposal requirement. 1 fig.

  20. Phytoextraction of excess soil phosphorus

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Nilesh C. [Department of Biology, Western Kentucky University, 1906 College Heights Boulevard 11080, Bowling Green, KY 42101-1080 (United States); Starnes, Daniel L. [Department of Biology, Western Kentucky University, 1906 College Heights Boulevard 11080, Bowling Green, KY 42101-1080 (United States); Sahi, Shivendra V. [Department of Biology, Western Kentucky University, 1906 College Heights Boulevard 11080, Bowling Green, KY 42101-1080 (United States)]. E-mail: shiv.sahi@wku.edu

    2007-03-15

    In the search for a suitable plant to be used in P phytoremediation, several species belonging to legume, vegetable and herb crops were grown in P-enriched soils, and screened for P accumulation potentials. A large variation in P concentrations of different plant species was observed. Some vegetable species such as cucumber (Cucumis sativus) and yellow squash (Cucurbita pepo var. melopepo) were identified as potential P accumulators with >1% (dry weight) P in their shoots. These plants also displayed a satisfactory biomass accumulation while growing on a high concentration of soil P. The elevated activities of phosphomonoesterase and phytase were observed when plants were grown in P-enriched soils, this possibly contributing to high P acquisition in these species. Sunflower plants also demonstrated an increased shoot P accumulation. This study shows that the phytoextraction of phosphorus can be effective using appropriate plant species. - Crop plants such as cucumber, squash and sunflower accumulate phosphorus and thus can be used in the phytoextraction of excess phosphorus from soils.

  1. RADIOIODINE GEOCHEMISTRY IN THE SRS SUBSURFACE ENVIRONMENT

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, D.; Emerson, H.; Powell, B.; Roberts, K.; Zhang, S.; Xu, C.; Schwer, K.; Li, H.; Ho, Y.; Denham, M.; Yeager, C.; Santschi, P.

    2013-05-16

    Iodine-129 is one of the key risk drivers for several Savannah River Site (SRS) performance assessments (PA), including that for the Low-Level Waste Disposal Facility in E-Area. In an effort to reduce the uncertainty associated with the conceptual model and the input values used in PA, several studies have recently been conducted dealing with radioiodine geochemistry at the SRS. The objective of this report was to review these recent studies and evaluate their implications on SRS PA calculations. For the first time, these studies measured iodine speciation in SRS groundwater and provided technical justification for assuming the presence of more strongly sorbing species (iodate and organo-iodine), and measured greater iodine sediment sorption when experiments included these newly identified species; specifically they measured greater sorption coefficients (K{sub d} values: the concentration ratio of iodine on the solid phase divided by the concentration in the aqueous phase). Based on these recent studies, new best estimates were proposed for future PA calculations. The new K{sub d} values are greater than previous recommended values. These proposed K{sub d} values reflect a better understanding of iodine geochemistry in the SRS subsurface environment, which permits reducing the associated conservatism included in the original estimates to account for uncertainty. Among the key contributing discoveries supporting the contention that the K{sub d} values should be increased are that: 1) not only iodide (I{sup -}), but also the more strongly sorbing iodate (IO{sub 3}{sup -}) species exists in SRS groundwater (average total iodine = 15% iodide, 42% iodate, and 43% organoiodine), 2) when iodine was added as iodate, the measured K{sub d} values were 2 to 6 times greater than when the iodine was added as iodide, and perhaps most importantly, 3) higher desorption (10 to 20 mL/g) than (ad)sorption (all previous studies) K{sub d} values were measured. The implications of this

  2. Earth materials and earth dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, K; Shankland, T. [and others

    2000-11-01

    In the project ''Earth Materials and Earth Dynamics'' we linked fundamental and exploratory, experimental, theoretical, and computational research programs to shed light on the current and past states of the dynamic Earth. Our objective was to combine different geological, geochemical, geophysical, and materials science analyses with numerical techniques to illuminate active processes in the Earth. These processes include fluid-rock interactions that form and modify the lithosphere, non-linear wave attenuations in rocks that drive plate tectonics and perturb the earth's surface, dynamic recrystallization of olivine that deforms the upper mantle, development of texture in high-pressure olivine polymorphs that create anisotropic velocity regions in the convecting upper mantle and transition zone, and the intense chemical reactions between the mantle and core. We measured physical properties such as texture and nonlinear elasticity, equation of states at simultaneous pressures and temperatures, magnetic spins and bonding, chemical permeability, and thermal-chemical feedback to better characterize earth materials. We artificially generated seismic waves, numerically modeled fluid flow and transport in rock systems and modified polycrystal plasticity theory to interpret measured physical properties and integrate them into our understanding of the Earth. This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL).

  3. Unusually Stable Helical Coil Allotrope of Phosphorus.

    Science.gov (United States)

    Liu, Dan; Guan, Jie; Jiang, Jingwei; Tománek, David

    2016-12-14

    We have identified an unusually stable helical coil allotrope of phosphorus. Our ab initio density functional theory calculations indicate that the uncoiled, isolated straight one-dimensional chain is equally stable as a monolayer of black phosphorus dubbed phosphorene. The coiling tendency and the attraction between adjacent coil segments add an extra stabilization energy of ∼12 meV/atom to the coil allotrope, similar in value to the ∼16 meV/atom interlayer attraction in bulk black phosphorus. Thus, the helical coil structure is essentially as stable as black phosphorus, the most stable phosphorus allotrope known to date. With an optimum radius of 2.4 nm, the helical coil of phosphorus may fit well and even form inside wide carbon nanotubes.

  4. Phosphorus-containing materials for organic electronics.

    Science.gov (United States)

    Stolar, Monika; Baumgartner, Thomas

    2014-05-01

    Phosphorus-based materials have received widespread attention in recent years, in particular as possible candidates for practical application in organic electronics. The geometry and electronic nature of phosphorus make it a favorable heteroatom for property tuning in order to obtain better performing organic electronics. This Focus Review discusses recent structural modifications and syntheses of phosphorus-based materials, illustrates property tuning at the same time, and highlights specific examples for device applications.

  5. Development of a Phosphorus-Eutrophication Management Strategy for Vermont: Evaluations Available Phosphorus Loads.

    Science.gov (United States)

    1985-11-01

    attention is biological phosphorus removal . 107 This technique has been known for many years, but is only now beginning to receive widespread use...phosphorus from biological treatment plants below that attainable using this technology alone. A recent study indicated that biological phosphorus removal has...Guide for HSPF, EPA 600/3-84-065 (1984). USEPA, Emerging Technology Assessment of Biological Phosphorus Removal , NTIS #PB-85 165-744 (1985). Velz, C. J

  6. DOE workshop: Sedimentary systems, aqueous and organic geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    1993-07-01

    A DOE workshop on sedimentary systems, aqueous and organic geochemistry was held July 15-16, 1993 at Lawrence Berkeley Laboratory. Papers were organized into several sections: Fundamental Properties, containing papers on the thermodynamics of brines, minerals and aqueous electrolyte solutions; Geochemical Transport, covering 3-D imaging of drill core samples, hydrothermal geochemistry, chemical interactions in hydrocarbon reservoirs, fluid flow model application, among others; Rock-Water Interactions, with presentations on stable isotope systematics of fluid/rock interaction, fluid flow and petotectonic evolution, grain boundary transport, sulfur incorporation, tracers in geologic reservoirs, geothermal controls on oil-reservoir evolution, and mineral hydrolysis kinetics; Organic Geochemistry covered new methods for constraining time of hydrocarbon migration, kinetic models of petroleum formation, mudstones in burial diagenesis, compound-specific carbon isotope analysis of petroleums, stability of natural gas, sulfur in sedimentary organic matter, organic geochemistry of deep ocean sediments, direct speciation of metal by optical spectroscopies; and lastly, Sedimentary Systems, covering sequence stratigraphy, seismic reflectors and diagenetic changes in carbonates, geochemistry and origin of regional dolomites, and evidence of large comet or asteroid impacts at extinction boundaries.

  7. Thermal, dynamic and compositional aspects of the core-forming Earth

    Science.gov (United States)

    Stevenson, D. J.

    1985-01-01

    Core formation is the most important and singular differentiation event in the history of a terrestrial planet. It almost certainly involved the downward migration of a partially or wholly molten iron alloy through a silicate and oxide mantle, and was contemporaneous with accretion. Several important, unresolved issues which have implications for mantle and core geochemistry, the thermal history of the Earth, and the origin of geomagnetism are addressed: whether the early Earth was molten; whether core formation involved low or high pressure geochemistry, or both; early Earth mantle homogenization; whether equilibration established between core forming material and the mantle through which it migrated; and how much iron is stranded and unable to reach the core.

  8. Geochemistry: Sulphur from heaven and hell

    Science.gov (United States)

    Dauphas, Nicolas

    2013-09-01

    Fingerprints of sulphur isotopes in rocks from the ridge beneath the Atlantic Ocean suggest that a substantial fraction of sulphur at Earth's surface is left over from the formation of the planet's core. See Letter p.208

  9. Phosphorus recovery from wastewater through microbial processes.

    Science.gov (United States)

    Yuan, Zhiguo; Pratt, Steven; Batstone, Damien J

    2012-12-01

    Waste streams offer a compelling opportunity to recover phosphorus (P). 15-20% of world demand for phosphate rock could theoretically be satisfied by recovering phosphorus from domestic waste streams alone. For very dilute streams (application is effective, but the product is bulky and carries contaminant risks that need to be managed. Phosphorus release can be achieved using either thermochemical or biochemical methods, while recovery is generally by precipitation as struvite. We conclude that while EBPR technology is mature, the subsequent phosphorus release and recovery technologies need additional development.

  10. Phosphorus removal in aerated stirred tank reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ghigliazza, R.; Lodi, A.; Rovatti, M. [Inst. of Chemical and Process Engineering ``G.B. Bonino``, Univ. of Genoa (Italy)

    1999-03-01

    The possibility to obtain biological phosphorus removal in strictly aerobic conditions has been investigated. Experiments, carried out in a continuous stirred tank reactor (CSTR), show the feasibility to obtain phosphorus removal without the anaerobic phase. Reactor performance in terms of phosphorus abatement kept always higher then 65% depending on adopted sludge retention time (SRT). In fact increasing SRT from 5 days to 8 days phosphorus removal and reactor performance increase but overcoming this SRT value a decreasing in reactor efficiency was recorded. (orig.) With 6 figs., 3 tabs., 18 refs.

  11. Towards global phosphorus security: A systems framework for phosphorus recovery and reuse options

    NARCIS (Netherlands)

    Cordell, D.; Rosemarin, A.; Schroder, J.J.; Smit, A.L.

    2011-01-01

    Human intervention in the global phosphorus cycle has mobilised nearly half a billion tonnes of the element from phosphate rock into the hydrosphere over the past half century. The resultant water pollution concerns have been the main driver for sustainable phosphorus use (including phosphorus recov

  12. Influence of feeding various phosphorus sources on apparent digestibility of phosphorus in dairy cows

    NARCIS (Netherlands)

    Ekelund, A.; Sporndly, R.; Valk, H.; Murphy, M.

    2003-01-01

    The present investigated differences in the apparent digestibility of phosphorus (ADP) in lactating cows fed various feed materials containing organic forms of phosphorus (P) or a highly available inorganic phosphorus source. Cows milking an average of 36 kg energy corrected milk (ECM) were used in

  13. Towards global phosphorus security: A systems framework for phosphorus recovery and reuse options

    NARCIS (Netherlands)

    Cordell, D.; Rosemarin, A.; Schroder, J.J.; Smit, A.L.

    2011-01-01

    Human intervention in the global phosphorus cycle has mobilised nearly half a billion tonnes of the element from phosphate rock into the hydrosphere over the past half century. The resultant water pollution concerns have been the main driver for sustainable phosphorus use (including phosphorus

  14. Geochemistry of vanadium (V) in Chinese coals.

    Science.gov (United States)

    Liu, Yuan; Liu, Guijian; Qu, Qinyuan; Qi, Cuicui; Sun, Ruoyu; Liu, Houqi

    2016-10-11

    Vanadium in coals may have potential environmental and economic impacts. However, comprehensive knowledge of the geochemistry of V in coals is lacking. In this study, abundances, distribution and modes of occurrence of V are reviewed by compiling >2900 reported Chinese coal samples. With coal reserves in individual provinces as the weighting factors, V in Chinese coals is estimated to have an average abundance of 35.81 μg/g. Large variation of V concentration is observed in Chinese coals of different regions, coal-forming periods, and maturation ranks. According to the concentration coefficient of V in coals from individual provinces, three regions are divided across Chinese coal deposits. Vanadium in Chinese coals is probably influenced by sediment source and sedimentary environment, supplemented by late-stage hydrothermal fluids. Specifically, hydrothermal fluids have relatively more significant effect on the enrichment of V in local coal seams. Vanadium in coals is commonly associated with aluminosilicate minerals and organic matter, and the modes of V occurrence in coal depend on coal-forming environment and coal rank. The Chinese V emission inventory during coal combustion is estimated to be 4906 mt in 2014, accounting for 50.55 % of global emission. Vanadium emissions by electric power plants are the largest contributor.

  15. Geochemistry studies in Eastern Kentucky. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Negus-de Wys, J.

    1981-04-01

    Presented here are the results of inorganic geochemical studies on well cuttings from fourteen wells in the Big Sandy Gas Field. Both x-ray fluorescence and x-ray diffraction were used in analysis. Resultant mineralic data and elemental data were mapped by computer and by hand for five intervals of Ohio Shale and for the Berea/Bedford sequence. Comparisons of the geochemistry trend maps were made with lithology, structure, thermal maturation, gas open flow, and paleoenvironment. Techniques used included visual map comparison, computer map comparison programs utilizing correlation coefficients based on grid derived data sets, cluster analysis, x-y plots, and r/sup 2/ (coefficient of determination). A limited number of regional maps are included. It is concluded that inorganic geochemical analysis can be useful in: (1) suggesting paleoenvironmental trends; (2) establishing depositional trends; (3) enhancing exploration in terms of setting limits and pinpointing potential areas for hydrocarbon recovery; and (4) identification of likely locations for large gas fields when used with other geological studies. Elemental data analysis is the most accurate, and can be done quickly and inexpensively. It is concluded that the Big Sandy gas field area is a unique stratigraphic-structural gas trap, in which sedimentary factors, depositional basin features, plant evolution and occurrence, and structural elements all played important roles. Combinations of certain of these ingredients in different amounts may exist in other parts of the basin, and thus, suggest areas for hydrocarbon accumulation and potential recovery.

  16. Snowball Earth

    OpenAIRE

    2016-01-01

    In the ongoing quest to better understand where life may exist elsewhere in the Universe, important lessons may be gained from our own planet. In particular, much can be learned from planetary glaciation events that Earth suffered ∼600 million years ago, so-called `Snowball Earth' episodes. I begin with an overview of how the climate works. This helps to explain how the ice-albedo feedback effect can destabilise a planet's climate. The process relies on lower temperatures causing more ice to ...

  17. Application of Hydrocarbons Biomarkers in Marine Organic Geochemistry

    Institute of Scientific and Technical Information of China (English)

    吴莹; 张经

    2001-01-01

    Biomarker is an important tool in the study of marine organic geochemistry. Its development and application makes it possible to elucidate the process and mechanism of the organic matter in the ocean. Hydrocarbons are the most useful molecular markers. They are used as tracers in many aspects, such as source indication; the degradation of organic matter; diagensis process; environmental pollution and paleooceanic study, etc. They are studied in the estuaries,coastal area and deep sea to give the knowledge of marine organic geochemistry. The paper deals with the characteristics, development and application ofbiomarkers as well as their advantages and disadvantages.

  18. Reservoir geochemistry: A link between reservoir geology and engineering?

    Energy Technology Data Exchange (ETDEWEB)

    Larter, S.R.; Aplin, A.C. [Univ. of Newcastle upon Tyne (United Kingdom); Corbett, P.; Ementon, N. [Heriot-Watt Univ., Edinburgh (United Kingdom)

    1994-12-31

    Geochemistry provides a natural but poorly exploited link between reservoir geology and engineering. The authors summarize some current applications of geochemistry to reservoir description and stress that because of their strong interactions with mineral surfaces and water, nitrogen and oxygen compounds in petroleum may exert an important influence on the PVT properties of petroleum, viscosity and wettability. The distribution of these compounds in reservoirs is heterogeneous on a sub-meter scale and is partly controlled by variations in reservoir quality. The implied variations in petroleum properties and wettability may account for some of the errors in reservoir simulations.

  19. Reservoir geochemistry: A link between reservoir geology and engineering?

    Energy Technology Data Exchange (ETDEWEB)

    Larter, S.R.; Aplin, A.C.; Chen, M.; Taylor, P.N. [Univ. of Newcastle (Australia); Corbett, P.W.M.; Ementon, N. [Heriot-Watt Univ., Edinburgh (United Kingdom)

    1997-02-01

    Geochemistry provides a natural, but poorly exploited, link between reservoir geology and engineering. The authors summarize some current applications of geochemistry to reservoir description and stress that, because of their strong interactions with mineral surfaces and water, nitrogen and oxygen compounds in petroleum may exert an important influence on the pressure/volume/temperature (PVT) properties of petroleum, viscosity and wettability. The distribution of these compounds in reservoirs is heterogeneous on a submeter scale and is partly controlled by variations in reservoir quality. The implied variations in petroleum properties and wettability may account for some of the errors in reservoir simulations.

  20. [Dietary reference intakes of phosphorus].

    Science.gov (United States)

    Uenishi, Kazuhiro

    2012-10-01

    Phosphorus (P) exists at the all organs and plays important physiological roles in the body. A wide range of food contains P, which is absorbed at a higher level (60-70%) and its insufficiency and deficiency are rarely found. P is used as food additives in many processed food, where risk of overconsumption could be an issue. P has less evidence in terms of nutrition. P has the adequate intake and the tolerable upper intake level, for risk reduction of health disorders associated with excess intake, at the Dietary Reference Intakes for Japanese (2010 edition).

  1. Geochemistry of Monazite within Carbonatite Related REE Deposits

    Directory of Open Access Journals (Sweden)

    Wei Chen

    2017-09-01

    Full Text Available Approximately >50% of global rare earth element (REE resources are hosted by carbonatite related deposits, of which monazite is one of the most important REE minerals. Monazite dominates more than 30 carbonatite-related REE deposits around the world, including currently exploited mineralization at Bayan Obo and Mount Weld. These deposits are widely distributed across all continents, except Antarctica. Though rare, monazite occurs as the primary mineral in carbonatite, and mostly presents as a secondary mineral that has a strong association with apatite. It can partially or completely replace thin or thick overgrowth apatite, depending on the availability of REE. Other mineral phases that usually crystallize together with monazite include barite, fluorite, xenotime, sulfide, and quartz in a carbonate matrix (e.g., dolomite, calcite. This review of monazite geochemistry within carbonatite-related REE deposits aims to provide information regarding the use of monazite as a geochemical indicator to track the formation history of the REE deposits and also supply additional information for the beneficiation of monazite. The chemical compositions of monazite are highly variable, and Ce-monazite is the dominant solid solution in carbonatite related deposits. Most monazite displays steep fractionation from La to Lu, absent of either Eu or Ce anomalies in the chondrite normalized REE plot. The other significant components are huttonite and cheratite. Some rare sulfur-bearing monazite is also identified with an SO3 content up to 4 wt %. A 147Sm/144Nd ratio with an average ~0.071 for monazite within carbonatite-related ores is similar to that of their host rocks (~0.065, and is the lowest among all types of REE deposits. Sm/Nd variation of monazite from a single complex reflects the differentiation stage of magma, which decreases from early to late. Based on the differences of Nd and Sr abundances, Nd isotopic composition for monazite can be used to track

  2. The 2009 Earth Science Literacy Principles

    Science.gov (United States)

    Wysession, M. E.; Budd, D. A.; Campbell, K. M.; Conklin, M. H.; Kappel, E. S.; Ladue, N.; Lewis, G.; Raynolds, R.; Ridky, R. W.; Ross, R. M.; Taber, J.; Tewksbury, B. J.; Tuddenham, P.

    2009-12-01

    In 2009, the NSF-funded Earth Science Literacy Initiative (ESLI) completed and published a document representing a community consensus about what all Americans should understand about Earth sciences. These Earth Science Literacy Principles, presented as a printed brochure and on the Internet at www.earthscienceliteracy.org, were created through the work of nearly 1000 geoscientists and geoeducators who helped identify nine “big ideas” and seventy-five “supporting concepts” fundamental to terrestrial geosciences. The content scope involved the geosphere and land-based hydrosphere as addressed by the NSF-EAR program, including the fields of geobiology and low-temperature geochemistry, geomorphology and land-use dynamics, geophysics, hydrologic sciences, petrology and geochemistry, sedimentary geology and paleobiology, and tectonics. The ESLI Principles were designed to complement similar documents from the ocean, atmosphere, and climate research communities, with the long-term goal of combining these separate literacy documents into a single Earth System Science literacy framework. The aim of these principles is to educate the public, shape the future of geoscience education, and help guide the development of government policy related to Earth science. For example, K-12 textbooks are currently being written and museum exhibits constructed with these Principles in hand. NPR-funded educational videos are in the process of being made in alignment with the ESLP Principles. US House and Senate representatives on science and education committees have been made aware that the major geoscience organizations have endorsed such a document generated and supported by the community. Given the importance of Earth science in so many societally relevant topics such as climate change, energy and mineral resources, water availability, natural hazards, agriculture, and human impacts on the biosphere, efforts should be taken to ensure that this document is in a position to

  3. Digital Earth - A sustainable Earth

    Science.gov (United States)

    Mahavir

    2014-02-01

    All life, particularly human, cannot be sustainable, unless complimented with shelter, poverty reduction, provision of basic infrastructure and services, equal opportunities and social justice. Yet, in the context of cities, it is believed that they can accommodate more and more people, endlessly, regardless to their carrying capacity and increasing ecological footprint. The 'inclusion', for bringing more and more people in the purview of development is often limited to social and economic inclusion rather than spatial and ecological inclusion. Economic investment decisions are also not always supported with spatial planning decisions. Most planning for a sustainable Earth, be at a level of rural settlement, city, region, national or Global, fail on the capacity and capability fronts. In India, for example, out of some 8,000 towns and cities, Master Plans exist for only about 1,800. A chapter on sustainability or environment is neither statutorily compulsory nor a norm for these Master Plans. Geospatial technologies including Remote Sensing, GIS, Indian National Spatial Data Infrastructure (NSDI), Indian National Urban Information Systems (NUIS), Indian Environmental Information System (ENVIS), and Indian National GIS (NGIS), etc. have potential to map, analyse, visualize and take sustainable developmental decisions based on participatory social, economic and social inclusion. Sustainable Earth, at all scales, is a logical and natural outcome of a digitally mapped, conceived and planned Earth. Digital Earth, in fact, itself offers a platform to dovetail the ecological, social and economic considerations in transforming it into a sustainable Earth.

  4. Sedimentary phosphorus cycling and a phosphorus mass balance for the Green Bay (Lake Michigan) ecosystem

    Science.gov (United States)

    Klump, J.V.; Edgington, D. N.; Sager, P.E.; Robertson, D.M.

    2011-01-01

    The tributaries of Green Bay have long been recognized as major sources of phosphorus in the Lake Michigan basin. The status of Green Bay as a sink or source of phosphorus for Lake Michigan proper has been less well defined. The bay receives nearly 70% of its annual load of phosphorus ( 700 metric tons (t) · year-1) from a single source: the Fox River. Most of this phosphorus is deposited in sediments accumulating at rates that reach 160 mg · cm-2 · year-1 with an average of 20 mg · cm-2 · year-1. The phosphorus content of these sediments varies from 70 µmol · g-1. Deposition is highly focused, with ~70% of the total sediment accumulation and at least 80% of the phosphorus burial occurring within 20% of the surface area of the bay. Diagenetic and stoichiometric models of phosphorus cycling imply that >80% of the phosphorus deposited is permanently buried. External phosphorus loading to the bay is combined with sediment fluxes of phophorus to arrive at a simple phosphorus budget. Green Bay acts as an efficient nutrient trap, with the sediments retaining an estimated 70-90% of the external phosphorus inputs before flowing into Lake Michigan.

  5. Plant growth, phosphorus nutrition, and root morphological responses to arbuscular mycorrhizas, phosphorus fertilization, and intraspecific density.

    Science.gov (United States)

    Schroeder, M S; Janos, D P

    2005-05-01

    We examined the effects of arbuscular mycorrhizas (AM), phosphorus fertilization, intraspecific density, and their interaction, on the growth, phosphorus uptake, and root morphology of three facultative mycotrophic crops (Capsicum annuum, Zea mays, and Cucurbita pepo). Plants were grown in pots with or without AM at three densities and four phosphorus availabilities for 10 weeks. AM colonization, plant weight, and shoot phosphorus concentration were measured at harvest. Root morphology was assessed for C. annuum and Z. mays. Phosphorus fertilization reduced but did not eliminate AM colonization of all species. AM, phosphorus, and density interacted significantly to modify growth of C. annuum and C. pepo such that increased density and phosphorus diminished beneficial effects of AM. Increased density reduced positive effects of AM on C. annuum and C. pepo shoot phosphorus concentrations. AM altered both Z. mays and C. annuum root morphology in ways that complemented potential phosphorus uptake by mycorrhizas, but increased density and phosphorus diminished these effects. We infer that increased density predominantly influenced plant responses by affecting whether or not carbon (photosynthate) or phosphorus limited plant growth. By exacerbating carbon limitation, high density reduced the benefit/cost ratio of mycorrhizas and minimized their effects.

  6. Reexamining the Phosphorus-Protein Dilemma: Does Phosphorus Restriction Compromise Protein Status?

    Science.gov (United States)

    St-Jules, David E; Woolf, Kathleen; Pompeii, Mary Lou; Kalantar-Zadeh, Kamyar; Sevick, Mary Ann

    2016-05-01

    Dietary phosphorus restriction is recommended to help control hyperphosphatemia in hemodialysis patients, but many high-phosphorus foods are important sources of protein. In this review, we examine whether restricting dietary phosphorus compromises protein status in hemodialysis patients. Although dietary phosphorus and protein are highly correlated, phosphorus intakes can range up to 600 mg/day for a given energy and protein intake level. Furthermore, the collinearity of phosphorus and protein may be biased because the phosphorus burden of food depends on: (1) the presence of phosphate additives, (2) food preparation method, and (3) bioavailability of phosphorus, which are often unaccounted for in nutrition assessments. Ultimately, we argue that clinically relevant reductions in phosphorus intake can be made without limiting protein intake by avoiding phosphate additives in processed foods, using wet cooking methods such as boiling, and if needed, substituting high-phosphorus foods for nutritionally equivalent foods that are lower in bioavailable phosphorus. Copyright © 2016 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

  7. Sustainable use of phosphorus: a finite resource.

    Science.gov (United States)

    Scholz, Roland W; Ulrich, Andrea E; Eilittä, Marjatta; Roy, Amit

    2013-09-01

    Phosphorus is an essential element of life and of the modern agricultural system. Today, science, policy, agro-industry and other stakeholder groups are increasingly concerned about the sustainable use of this resource, given the dissipative nature of phosphorus and difficulties in assessing, evaluating, and coping with phosphorus pollution in aquatic and terrestrial systems. We argue that predictions about a forthcoming peak, followed by a quick reduction (i.e., physical phosphate rock scarcity) are unreasoned and stress that access to phosphorus (economic scarcity) is already, and may increasingly become critical, in particular for smallholders farmers in different parts of the world. The paper elaborates on the design, development, goals and cutting-edge contributions of a global transdisciplinary process (i.e. mutual learning between science and society including multiple stakeholders) on the understanding of potential contributions and risks related to the current mode of using phosphorus on multiple scales (Global TraPs). While taking a global and comprehensive view on the whole phosphorus-supply chain, Global TraPs organizes and integrates multiple transdisciplinary case studies to better answer questions which inform sustainable future phosphorus use. Its major goals are to contribute to four issues central to sustainable resource management: i) long-term management of biogeochemical cycles, in particular the challenge of closing the phosphorus cycle, ii) achieving food security, iii) avoiding environmental pollution and iv) sustainability learning on a global level by transdisciplinary processes. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Virus production in phosphorus-limited

    NARCIS (Netherlands)

    Maat, D.S.; van Bleijswijk, J.D.L.; Witte, H.J.; Brussaard, C.P.D.

    2016-01-01

    Earlier studies show that the proliferation of phytoplankton viruses can be inhibited by depletion of soluble reactive phosphorus (SRP; orthophosphate). In natural marine waters, phytoplankton phosphorus (P) availability is, however, largely determined by the supply rate of SRP (e.g. through reminer

  9. Geochemistry and the origin of life

    Science.gov (United States)

    Kvenvolden, K. A.

    1974-01-01

    The origin of life on earth is examined from a viewpoint stressing the validity of the concept of chemical evolution. The different geological formations supporting the mechanisms of the theory are described; the stage of chemical evolution (preceding that of biological evolution) would have taken place from the time of the origin of the earth and meteorites, 4.6 billion years ago, to the early Precambrian period, about 3.2 billion years ago. Specific aspects of the problem discussed include amino acids from spark discharges and their comparison with the Murchison meteorite amino acids, the properties and theory of genesis of the carbonaceous complex within the cold Bokevelt meteorite, ammonion ion concentration in the primitive ocean, the oxygen isotope chemistry of ancient charts, the origin and rise of oxygen concentration in the earth's atmosphere, Precambrian microorganisms and evolutionary events prior to the origin of vascular plants, and biogenicity and significance of the oldest known stromatolites.

  10. Microbiology and Geochemistry of Antarctic Paleosols

    Science.gov (United States)

    Mahaney, W. C.; Malloch, D.; Hancock, R. G. V.; Campbell, I. B.; Sheppard, D.

    2000-08-01

    Samples of ancient soils from horizons in paleosols from the Quartermain Mountains (Aztec and New Mountain areas of the Antarctic Dry Valleys) were analyzed for their chemical composition and microbiology to determine the accumulation and movement of salts and other soluble constituents. The salt concentrations are of special interest because they are considered to be a function of age, derived in part from nearby oceanic and high altitude atmospheric sources. The geochemistry of ancient Miocene-age paleosols in these areas is the direct result of the deposition and weathering of till, derived principally from dolerite and sandstone source rock, in association with airborne-influxed salts. Paleosols nearer the coast have greater contents of chlorine, and farther inland near the Inland Ice Sheet, nitrogen tends to increase on a relative basis. The accumulation and vertical distribution of salts and other soluble chemical elements indicate relative amounts of movement in the profile over long periods of time, to the order of several million years. Iron, both in total concentration and in the form of various extracts, indicates it can be used as a geochronometer to assess the buildup of goethite plus hematite over time in the paleosols. Trends for ferrihydrite, a partially soluble Fe-hydroxide, shows limited profile translocation that might be related to the movement of salt. Six of the eight selected subsamples from paleosol horizons in three soil profiles contained nil concentrations of bacteria and fungi. However, two horizons at depths of between three to eight centimeters yielded several colonies of the fungi Beauveria bassiana and Penicillium spp., indicating some input of organic carbon. Beauveria bassiana is often reported in association with insects and is used commercially for the biological control of some insect pests. Penicillium species are commonly isolated from Arctic, temperate and tropical soils and are known to utilize a wide variety of organic

  11. Ultrafast pulse generation with black phosphorus

    CERN Document Server

    Li, Diao; Karvonen, Lasse; Ye, Guojun; Lipsanen, Harri; Chen, Xianhui; Sun, Zhipei

    2015-01-01

    Black phosphorus has been recently rediscovered as a new and interesting two-dimensional material due to its unique electronic and optical properties. Here, we study the linear and nonlinear optical properties of black phosphorus thin films, indicating that both linear and nonlinear optical properties are anisotropic and can be tuned by the film thickness. Then we employ the nonlinear optical property of black phosphorus for ultrafast (pulse duration down to ~786 fs in mode-locking) and large-energy (pulse energy up to >18 nJ in Q-switching) pulse generation in fiber lasers at the near-infrared telecommunication band ~1.5 {\\mu}m. Our results underscore relatively large optical nonlinearity in black phosphorus and its prospective for ultrafast pulse generation, paving the way to black phosphorus based nonlinear and ultrafast photonics applications (e.g., ultrafast all-optical switches/modulators, frequency converters etc.).

  12. Prebiotic Phosphorylation Reactions on the Early Earth

    Directory of Open Access Journals (Sweden)

    Maheen Gull

    2014-07-01

    Full Text Available Phosphorus (P is an essential element for life. It occurs in living beings in the form of phosphate, which is ubiquitous in biochemistry, chiefly in the form of C-O-P (carbon, oxygen and phosphorus, C-P, or P-O-P linkages to form life. Within prebiotic chemistry, several key questions concerning phosphorus chemistry have developed: what were the most likely sources of P on the early Earth? How did it become incorporated into the biological world to form the P compounds that life employs today? Can meteorites be responsible for the delivery of P? What were the most likely solvents on the early Earth and out of those which are favorable for phosphorylation? Or, alternatively, were P compounds most likely produced in relatively dry environments? What were the most suitable temperature conditions for phosphorylation? A route to efficient formation of biological P compounds is still a question that challenges astrobiologists. This article discusses these important issues related to the origin of biological P compounds.

  13. Rare earth element geochemistry of dolostones and its indicative significance of the Permian Changxing Formation in Yuanba Gasfield,northern Sichuan Basin%川北元坝气田二叠系长兴组白云岩稀土元素地球化学特征及其指示意义

    Institute of Scientific and Technical Information of China (English)

    余新亚; 李平平; 邹华耀; 王广伟; 张毅

    2015-01-01

    Rare earth element (REE) and Yttrium (Y) concents were determined from 49 carbon-ate samples of the Permian Changxing Formation of Yuanba Gasfield in northern Sichuan Basin,and the results show that the total content of rare earth elements (REE ) is generally low (average 1 .50 ×1 0 -6 ),which indicates that rock samples were almost without any terrigenous clastics,and not be affect-ed by the deep hydrothermal fluids.Shale-normalized REE characteristics of dolostone including light rare earth element (LREE) depletion,positive La anomalies,negative Ce anomalies (0.49 to 1 .08,aver-age 0.75),positive Eu anomalies (0.89 to 46.00,average 4.68)of different degrees and the higher Y /Ho ratios (28.82 to 63.47,average 43.04)recorded seawater-like REE and Y signatures,which show that the dolomitization fluids is reductive seawater derived,and the dolomitization occurred in a buri-al environment.The brecciated or zebra typical structure of hydrothermal dolostones were not observed in the cores and petrographic thin sections.Flattened structure and the horizontal continuous distribution of dolomite reservoirs and the higher δ1 8O value (-7.07‰ to -2.92‰,average -4.95‰) illustrate that no obvious hydrothermal activities occurred in the study area,and the higher degree of positive Eu anomalies have no relationship with the deep hydrothermal fluids.Many elemental sulfurs and sulfur-rich pyrobitumen originated from thermochemical sulfate reduction (TSR)can be observed by scanning electron micro-scope,which indicates that TSR created an extremely reducing environment of stratal seawater,and then caused the higher degree of positive Eu anomalies,which in turn explains that TSR had a certain dissolu-tion on dolomite reservoirs.%川北元坝气田二叠系长兴组49个碳酸盐岩样品的稀土元素(REE)和钇(Y)含量的测试结果表明:稀土元素总量(ΣREE)普遍较低(平均1.50×10-6),说明岩石样品几乎无陆源碎屑的混入,

  14. Geochemistry and mineralogy of Ogun phosphate rock

    African Journals Online (AJOL)

    user

    The alkali metals K2O and Na2O are variable and low ... INTRODUCTION. Sustainability of human life on earth depends on ... process thus confirming the earlier work done by Jones and Hockey (1964) and ..... An isotopic outlook. Nutrient ...

  15. Geochemistry of trace metals in the Scheldt estuary

    NARCIS (Netherlands)

    Zwolsman, J.J.G.

    1999-01-01

    The distribution of trace metals has been studied in abiotic compartments of the ScheIdt estuary (water column and sediments). Seasonal surveys, carried out in 1987-1988, indicate that the geochemistry of dissolved trace metals (Cd, Cu, Zn) is determined by the redox status of the upper estuary, and

  16. Petrology and geochemistry of igneous inclusions in recent Merapi deposits

    DEFF Research Database (Denmark)

    Chadwick, J.P.; Troll, V.R.; Waight, Tod Earle

    2013-01-01

    , geochemistry and geobarometric calculations. The inclusions may be classified into four main suites: (1) highly crystalline basaltic-andesite inclusions, (2) co-magmatic enclaves, (3) plutonic crystalline inclusions and (4) amphibole megacrysts. Highly crystalline basaltic-andesite inclusions and co...

  17. Major, trace and REE geochemistry of recent sediments from lower Catumbela River (Angola)

    Science.gov (United States)

    Vinha, Manuela; Silva, M. G.; Cabral Pinto, Marina M. S.; Carvalho, Paula Cristina S.

    2016-03-01

    The mineralogy, texture, major, trace and rare earth elements, from recent sediment samples collected in the lower Catumbela River, were analysed in this study to characterize and discuss the factors controlling its geochemistry and provide data that can be used as tracers of Catumbela River inputs to the Angolan continental shelf. The sediments are mainly sands and silty-sands, but sandy-silt also occurs and the mineralogy is composed of quartz, feldspar, phyllosilicates, magnetite, ilmenite and also carbonates when the river crosses limestones and marls in the downstream sector. The hydraulic sorting originates magnetite-ilmenite and REE-enriched minerals placers. The mineralogy of the sediments is controlled by the source rocks and the degree of chemical weathering is lower than erosion. The texture is mainly controlled by location. There is enrichment in all the analysed trace elements in the fine grained, clay minerals and Fe-oxy-hydroxides rich sediments, compared to the coarse grained and quartz plus feldspar rich ones. The coarse grained sediments (without the placers) are impoverished in ΣREE when compared with UCC and NASC compositions, while the fine grained sediments have ΣREE contents similar to UCC and NASC. The placers have ΣREE contents up to 959.59 mg/kg. The source composition is the dominant factor controlling the REE geochemistry of the analysed sediments as there is no difference in the (La/Yb)N, (La/Sm)N and (Gd/Yb)N ratios in coarse and fine grained sediments. The sorting of magnetite, ilmenite, zircon, throrite, thorianite, rutile and titanite explain the HREE/LREE enriched patterns of the coarse grained sediments.

  18. Climate and geochemistry as drivers of eucalypt diversification in Australia.

    Science.gov (United States)

    Bui, E N; Thornhill, A H; González-Orozco, C E; Knerr, N; Miller, J T

    2017-05-01

    Eucalypts cover most of Australia. Here, we investigate the relative contribution of climate and geochemistry to the distribution and diversity of eucalypts. Using geostatistics, we estimate major element concentrations, pH, and electrical conductivity at sites where eucalypts have been recorded. We compare the median predicted geochemistry and reported substrate for individual species that appear associated with extreme conditions; this provides a partial evaluation of the predictions. We generate a site-by-species matrix by aggregating observations to the centroids of 100-km-wide grid cells, calculate diversity indices, and use numerical ecology methods (ordination, variation partitioning) to investigate the ecology of eucalypts and their response to climatic and geochemical gradients. We find that β-diversity coincides with variations in climatic and geochemical patterns. Climate and geochemistry together account for less than half of the variation in eucalypt species assemblages across Australia but for greater than 80% in areas of high species richness. Climate is more important than geochemistry in explaining eucalypts species distribution and change in assemblages across Australia as a whole but there are correlations between the two sets of environmental variables. Many individual eucalypt species and entire taxonomic sections (Aromatica, Longistylus of subgenus Eucalyptus, Dumaria, and Liberivalvae of subgenus Symphyomyrtus) have distributions affected strongly by geochemistry. We conclude that eucalypt diversity is driven by steep geochemical gradients that have arisen as climate patterns have fluctuated over Australia over the Cenozoic, generally aridifying since the Miocene. The diversification of eucalypts across Australia is thus an excellent example of co-evolution of landscapes and biota in space and time and challenges accepted notions of macroecology. © 2017 John Wiley & Sons Ltd.

  19. Characterizing the proposed geologic repository for high-level radioactive waste at Yucca Mountain, Nevada: hydrology and geochemistry

    Science.gov (United States)

    Stuckless, John S.; Levich, Robert A.

    2012-01-01

    This hydrology and geochemistry volume is a companion volume to the 2007 Geological Society of America Memoir 199, The Geology and Climatology of Yucca Mountain and Vicinity, Southern Nevada and California, edited by Stuckless and Levich. The work in both volumes was originally reported in the U.S. Department of Energy regulatory document Yucca Mountain Site Description, for the site characterization study of Yucca Mountain, Nevada, as the proposed U.S. geologic repository for high-level radioactive waste. The selection of Yucca Mountain resulted from a nationwide search and numerous committee studies during a period of more than 40 yr. The waste, largely from commercial nuclear power reactors and the government's nuclear weapons programs, is characterized by intense penetrating radiation and high heat production, and, therefore, it must be isolated from the biosphere for tens of thousands of years. The extensive, unique, and often innovative geoscience investigations conducted at Yucca Mountain for more than 20 yr make it one of the most thoroughly studied geologic features on Earth. The results of these investigations contribute extensive knowledge to the hydrologic and geochemical aspects of radioactive waste disposal in the unsaturated zone. The science, analyses, and interpretations are important not only to Yucca Mountain, but also to the assessment of other sites or alternative processes that may be considered for waste disposal in the future. Groundwater conditions, processes, and geochemistry, especially in combination with the heat from radionuclide decay, are integral to the ability of a repository to isolate waste. Hydrology and geochemistry are discussed here in chapters on unsaturated zone hydrology, saturated zone hydrology, paleohydrology, hydrochemistry, radionuclide transport, and thermally driven coupled processes affecting long-term waste isolation. This introductory chapter reviews some of the reasons for choosing to study Yucca Mountain as a

  20. Characterizing the proposed geologic repository for high-level radioactive waste at Yucca Mountain, Nevada--hydrology and geochemistry

    Science.gov (United States)

    Stuckless, John S.; Levich, Robert A.

    2012-01-01

    This hydrology and geochemistry volume is a companion volume to the 2007 Geological Society of America Memoir 199, The Geology and Climatology of Yucca Mountain and Vicinity, Southern Nevada and California, edited by Stuckless and Levich. The work in both volumes was originally reported in the U.S. Department of Energy regulatory document Yucca Mountain Site Description, for the site characterization study of Yucca Mountain, Nevada, as the proposed U.S. geologic repository for high-level radioactive waste. The selection of Yucca Mountain resulted from a nationwide search and numerous committee studies during a period of more than 40 yr. The waste, largely from commercial nuclear power reactors and the government's nuclear weapons programs, is characterized by intense penetrating radiation and high heat production, and, therefore, it must be isolated from the biosphere for tens of thousands of years. The extensive, unique, and often innovative geoscience investigations conducted at Yucca Mountain for more than 20 yr make it one of the most thoroughly studied geologic features on Earth. The results of these investigations contribute extensive knowledge to the hydrologic and geochemical aspects of radioactive waste disposal in the unsaturated zone. The science, analyses, and interpretations are important not only to Yucca Mountain, but also to the assessment of other sites or alternative processes that may be considered for waste disposal in the future. Groundwater conditions, processes, and geochemistry, especially in combination with the heat from radionuclide decay, are integral to the ability of a repository to isolate waste. Hydrology and geochemistry are discussed here in chapters on unsaturated zone hydrology, saturated zone hydrology, paleohydrology, hydrochemistry, radionuclide transport, and thermally driven coupled processes affecting long-term waste isolation. This introductory chapter reviews some of the reasons for choosing to study Yucca Mountain as a

  1. Geochemistry and mineralogy of mafic Icelandic hyaloclastites

    Science.gov (United States)

    Hudak, M. R.; Feineman, M. D.; Eyer, C.; Bindeman, I. N.; Sigmarsson, O.

    2016-12-01

    Hyaloclastite in the crust may be a cryptic contaminant contributing to some volatile-rich Icelandic basalts and in some places reach 2.5 km1. Hyaloclastites are highly fragmented composites of lithics, glass, and crystals in a palagonite matrix that form as a result of magma-ice or magma-water interactions. These rocks have high water content and porosity and a high initial glass content, which makes them susceptible to rapid alteration by ambient or hydrothermal waters and potentially fast digestion by magmas. Due to low density and ductility, they have the potential to stall ascending mantle-derived magmas to form sills, and in the process may contribute exotic volatile or fluid-mobile components. We have characterized the geochemistry and mineralogy of 18 hyaloclastite samples from the Reykjanes Peninsula (RP), Vestmannajyar, and the southern coast of Iceland. Major and trace elements were obtained using ICP-AES and ICP-MS, respectively, and mineralogy was determined by XRD. Loss on ignition is highly variable (0.44 - 15.7 wt.%) and positively correlated with alkali loss reflected in the Chemical Index of Alteration [34.8 - 51.3; CIA = Al2O3/(Al2O3+CaO+Na2O+K2O)]. Primitive mantle normalized multi-element plots for RP hyaloclastites are broadly similar to those for unaltered RP Holocene basalts. Two samples have trace element profiles resembling those of picrites in the region. The samples from the south coast and Vestmannaeyjar have OIB-like enrichments similar to local Holocene basalts. Five well-sorted hyaloclastite samples have broad humps in their XRD patterns from 20-50° 2q. These samples contain only primary magmatic mineral phases (plagioclase, olivine, and pyroxene), if any, while other hyaloclastites contain both primary phases and secondary alteration phases including halite, calcite, clays, chlorite, and zeolites. Preliminary O and H isotope investigation demonstrates large ranges in both parameters. Future work will include oxygen isotope analyses

  2. Prevalence of phosphorus containing food additives in grocery stores

    Directory of Open Access Journals (Sweden)

    Janeen B. Leon

    2012-06-01

    In conclusion, phosphorus additives are commonly present in groceries and contribute significantly to the phosphorus content of foods. Moreover, phosphorus additive foods are less costly than additive-free foods. As a result, phosphorus additives may be an important contributor to hyperphosphatemia among persons with chronic kidney disease

  3. 49 CFR 173.188 - White or yellow phosphorus.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false White or yellow phosphorus. 173.188 Section 173... Class 7 § 173.188 White or yellow phosphorus. Phosphorus, white or yellow, when offered for... pound) of phosphorus with screw-top closures; or (2) Steel drums (1A1) not over 250 L (66...

  4. The electron affinity of phosphorus

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, P [Department of Physics, Goeteborg University, SE-412 96, Goeteborg (Sweden); Lindahl, A O [Department of Physics, Goeteborg University, SE-412 96, Goeteborg (Sweden); Alfredsson, C [Department of Physics, Goeteborg University, SE-412 96, Goeteborg (Sweden); Rogstroem, L [Department of Physics, Goeteborg University, SE-412 96, Goeteborg (Sweden); Diehl, C [Institut fuer Physik, Johannes Gutenberg-Universitaet, Mainz, D-55099 Mainz (Germany); Pegg, D J [Department of Physics, University of Tennessee, Knoxville, TN 37996 (United States); Hanstorp, D [Department of Physics, Goeteborg University, SE-412 96, Goeteborg (Sweden)

    2007-10-28

    We have measured the energies of all three fine structure components in the {sup 3}P{sub J} ground state of the negative ion of phosphorus using laser photodetachment threshold spectroscopy. The experiment yielded an electron affinity of 746.68(6) meV. The {delta}J = 2-0, 2-1 and 1-0 fine structure splittings were determined to be 32.73(7) meV, 22.48(7) meV and 10.25(3) meV, respectively. In the experiment, a mass selected beam of P{sup -} ions was merged with the output from a pulsed infrared optical parametric oscillator. The residual atoms produced in the photodetachment process were detected and used as a monitor of the photon-energy dependence of the relative cross section. The Wigner law was fitted to each of the three observed onsets of production of neutrals in order to extract the threshold energies.

  5. Anthropogenic phosphorus flows in Denmark

    DEFF Research Database (Denmark)

    Klinglmair, Manfred

    is coupled with dependence on imports from a limited number of suppliers outside the EU-28, so that the EU updated its list of critical raw materials in 2014 to include phosphate rock. As a plant nutrient, P is not destroyed by human use, but dissipated into the environment, where it is a pollutant......Phosphorus (P) is an essential plant nutrient mined from the earth’s crust as phosphate rock. It cannot be substituted, making it a crucial resource for food production. For the EU, future phosphate scarcity is a potential geopolitical and strategic threat. An increasing worldwide phosphate demand...... contributing to eutrophication of water bodies and soils. The anthropogenic P is open on the global scale, with global shipments of animal feed, fertiliser, and food; and on the local scale, through the inefficient use of fertiliser or animal manure by application in excess of plant P demand, and losses...

  6. Black phosphorus for future devices

    Science.gov (United States)

    Meunier, Vincent

    Black phosphorus (or ``phosphorene'' at the monolayer limit) has attracted significant attention as an emerging 2D material due to its unique properties compared with well-explored graphene and transition metal dichalcogenides such as MoS2 and WSe2. In bulk form, this monoelemental layered structure is a highly anisotropic semiconductor with a bandgap of 0.3 eV which presents marked distinctions in optical and electronic properties depending on crystalline directions. In addition, black phosphorus possesses a high carrier mobility, making it promising for applications in high frequency electronics. A large number of characterization studies have been performed to understand the intrinsic properties of BP. Here I wil present a number of investigations where first-principles modelling was combined with scanning tunneling microscopy (STM), Raman spectroscopy, and transmission electron microscopy (TEM) to assist in the design of phosphorene-based devices. . I will provide an overview of these studies and position them in the context of the very active research devoted to this material. In particular, I will show how low-frequency Raman spectra provide a unique handle on the physics of multilayered systems and how BP's structural anisotropy weaves its way to its unusual polarization dependent Raman signature. Finally, I will show recent progress where nanopores, nanobridges, and nanogaps have been sculpted directly from a few-layer BP sample using a TEM, and indicate the potential use of these results on the creation of phosphorene-based nanoelectronics. I wil conclude this talk with a critical look at the issues of phosphorene stability under ambient conditions. Collaborators on this research include: Liangbo Liang, Bobby G. Sumpter, Alex Puretzky, Minghu Pan, (Oak Ridge National Laboratory), Marija Drndic (University of Pennsylvania), Mildred Dresselhaus, Xi-Ling, Shengxi Huang (Massachusetts Institute of Technology).

  7. IMPROVING PHOSPHORUS NUTRITION OF CORN

    Directory of Open Access Journals (Sweden)

    Walter B. Gordon

    2014-01-01

    Full Text Available Phosphorus (P generally occurs in soils as the anions H2PO4- or HPO4-2 depending on soil pH. These anions readily react with soil cations such as calcium, magnesium, iron and aluminum to produce various phosphate compounds of very limited water solubility. Crop recovery of applied phosphate fertilizer can be quite low during the season of application. In addition, the large amounts of crop residue present in no-tillage production systems can lower soil temperature thus reducing root growth and nutrient uptake of plants even on soils not low in available Phosphorus (P. Specialty Fertilizer Products, Leawood, KS has developed and patented a product registered as AVAIL® that is reported to attract and sequester antagonistic cations out of the soil solution leaving more of the applied P in available form for plant uptake. The objective of this experiment was to evaluate the effectiveness of AVAIL treated P-fertilizer on growth, P-uptake and yield of irrigated corn (Zea mays L. grown in a no-tillage production system. A 3-year experiment was conducted from 2001-2003 at the North Central Kansas Experiment Field, located near Scandia, KS, on a Crete silt loam soil (fine, montmorillonitic, mesic Pachic Arquistoll. Treatments consisted of three rates of P with or without AVAIL. A no P check plot was also included. When averaged over the years and P rates, the use of AVAIL increased yield of corn by 1.1 Mg ha-1. AVAIL also increased corn dry weight at the six-leaf stage, whole plant P uptake at the six-leaf stage and P concentration at mid-silk. The use of AVAIL proved beneficial in overcoming many of the problems associated with P nutrition in corn. AVAIL consistently increased P uptake and yield in this experiment.

  8. Mineralogia e geoquímica de perfis de solo com Terra Preta Arqueológica de Bom Jesus do Tocantins, sudeste da Amazônia Mineralogy and geochemistry of soil profiles with Archeological Black Earth from Bom Jesus do Tocantins, southeastern Amazon

    Directory of Open Access Journals (Sweden)

    Any Kelly Terra da Silva

    2012-01-01

    chemical data of a soil with anthropic horizons - Archeological Black Earth (ABE and surrounding Argissolos (Typic Kandiudox or Ultisols allowed the identification of the main process acting on the ABE formation from the town of Bom Jesus do Tocantins, southeastern Pará State. The similarity between the data in the subsurface horizons of ABE and surrounding soils indicates that the former was likely developed from Argissolos with later pedogenetic transformation by the input of organic and inorganic materials from ancient human settlements, which resulted in thickness of the surface horizon and higher concentrations of CaO and P2O5 (total content, Zn (trace content, available P and Zn (available content, and exchangeable Ca and Mg (exchangeable content compared to surrounding Argissolos. Furthermore, such anthropic disturbance also resulted in changes in the subsurface horizon of Argissolos with ABE, such as high concentrations of P2O5 and available P. The Soil Taxonomy and Brazilian System of Soil Classification (BSSC are suitable to identify soils with ABE, as they prioritize at the highest categorical level the main pedogenetic process acting on soil development and formation, related to the subsurface horizons, and later pedogenetic transformations in the surface horizon. However, this study proposes the addition of diagnostic properties such as ceramic and lithic artifacts, P2O5 and available P and Zn, organic C, Ca2++ Mg2+ (exchangeable content, CEC and base saturation in the surface horizon to classify and discriminate several kinds of anthropic soils in the Amazon region.

  9. Impact of phosphorus control measures on in-river phosphorus retention associated with point source pollution

    Directory of Open Access Journals (Sweden)

    B. O. L. Demars

    2005-01-01

    Full Text Available In-river phosphorus retention alters the quantity and timings of phosphorus delivery to downstream aquatic systems. Many intensive studies of in-river phosphorus retention have been carried out but generally on a short time scale (2-4 years. In this paper, monthly water quality data, collected by the Environment Agency of England and Wales over 12 years (1990-2001, were used to model daily phosphorus fluxes and monthly in-river phosphorus retention in the lowland calcareous River Wensum, Norfolk, UK. The effectiveness of phosphorus stripping at two major sewage treatment works was quantified over different hydrological conditions. The model explained 78% and 88% of the observed variance before and after phosphorus control, respectively. During relatively dry years, there was no net export of phosphorus from the catchment. High retention of phosphorus occurred, particularly during the summer months, which was not compensated for, by subsequent higher flow events. The critical discharge (Q above which net remobilisation would occur, was only reached during few, high flow events Q25-Q13. Phosphorus removal from the effluent at two major STWs (Sewage Treatment Works reduced the phosphorus catchment mass balance variability by 20-24% under the Q99-Q1. range of flow conditions. Although the absorbing capacity of the catchment against human impact was remarkable, further phosphorus remedial strategies will be necessary to prevent downstream risks of eutrophication occuring independently of the unpredictable variability in weather conditions.

  10. Towards global phosphorus security: a systems framework for phosphorus recovery and reuse options.

    Science.gov (United States)

    Cordell, D; Rosemarin, A; Schröder, J J; Smit, A L

    2011-08-01

    Human intervention in the global phosphorus cycle has mobilised nearly half a billion tonnes of the element from phosphate rock into the hydrosphere over the past half century. The resultant water pollution concerns have been the main driver for sustainable phosphorus use (including phosphorus recovery). However the emerging global challenge of phosphorus scarcity with serious implications for future food security, means phosphorus will also need to be recovered for productive reuse as a fertilizer in food production to replace increasingly scarce and more expensive phosphate rock. Through an integrated and systems framework, this paper examines the full spectrum of sustainable phosphorus recovery and reuse options (from small-scale low-cost to large-scale high-tech), facilitates integrated decision-making and identifies future opportunities and challenges for achieving global phosphorus security. Case studies are provided rather than focusing on a specific technology or process. There is no single solution to achieving a phosphorus-secure future: in addition to increasing phosphorus use efficiency, phosphorus will need to be recovered and reused from all current waste streams throughout the food production and consumption system (from human and animal excreta to food and crop wastes). There is a need for new sustainable policies, partnerships and strategic frameworks to develop renewable phosphorus fertilizer systems for farmers. Further research is also required to determine the most sustainable means in a given context for recovering phosphorus from waste streams and converting the final products into effective fertilizers, accounting for life cycle costs, resource and energy consumption, availability, farmer accessibility and pollution.

  11. Mineralogy and Geochemistry of Upper Maastrichtian-Middle Eocene Clay - Rich Volcano - Sedimentary Units from South-Eastern of Elazıg Basin (Eastern Turkey)

    Science.gov (United States)

    Akkoca, Dicle Bal; Daş, Burhan

    2017-04-01

    Clay-rich Hazar-Maden volcano-sediments were deposited along the southern branch of the Neotethys Ocean margin during Upper Maastrichtian - Middle Eocene times. Mineralogy and geochemistry of Hatunkoy section from the south - easthern of Elazıg were studied by X-ray powder diffraction (XRD), ICP-AES, ICP-MS. The Upper Jurassic - Lower Cretaceous Guleman Ophiolites, Upper Maastrichtian - Middle Eocene Hazar Group, the Middle Eocene Maden Group, Pliocene-Quaternary alluvial deposits are situated in the study area. The Guleman Ophiolites are composed of dunite, harzburgite with podiform chromite, alternating dunite-wherlite, clinopyroxenite banded gabbro, quartz gabbro/diorite or plagiogranite and volcanites. The Hazar Group consists of limestone and interbedded shale and sandstone. The Maden Group has a complex lithology consisting of limestones, red-green clayey limestones, sandstone, agglomerate, tuffs, reddish mudstone and basaltic-andesitic pillow lavas. Mineralogy and geochemistry of Hazar and Maden Group samples are similar in Hatunkoy section. All samples consist of clay minerals (chlorite, illite), calcite, quartz, and feldspar. SiO2, Al2O3, Fe2O3, K2O contents show that samples are convenient with Fe shales and shales. The ratios of Zr/TiO2, Th/Sc, Zr/Sc, Y/Ni-Cr/V, Al/(Al+Fe+Mn) show dominance of neutral-basic volcanism in the area. Rare earth elements (REE) concentrations of samples are normalized to chondrite values and it is determined that low light rare earth elements (LREEs) are enriched in comparison to high rare earth elements (HREEs), and the absence of Eu anomalies shows that our samples are generally neutral-basic in composition. REE of samples were compared with North American shale composite (NASC), European shale (ES) and Post-Archean Australian shale (PAAS). Elements are not in concurrence with these compositions. Key Words:Mineralogy, Geochemistry, Volcano sedimentary Units, Eastern Turkey.

  12. Total Phosphorus in Surface Water (Future)

    Data.gov (United States)

    U.S. Environmental Protection Agency — Excess phosphorus in surface water can result in eutrophication. TOTALPFuture is reported in kilograms/hectare/year. More information about these resources,...

  13. [Lack of phosphorus intake and nutrition].

    Science.gov (United States)

    Takeda, Eiji; Ikeda, Syoko; Nakahashi, Otoki

    2012-10-01

    Since one gram of protein in food provides approximately 15 mg of phosphorus, phosphorus deficiency frequently observed in patients with protein-energy malnutrition (PEM). Chronic phosphorus deficiency in humans causes proximal myopathy. Acute hypophosphatemia may precipitate rhabdomyolysis. Plasma low phosphorus concentration suppresses erythrocyte synthesis and stores of 2,3-diphosphoglycerate (2,3-DPG) , which plays an important role in the affinity of hemoglobin for oxygen. Symptoms of nervous system dysfunction, such as weakness, apathy, a bedridden state, and intention tremors, are also observed in severe hypophosphatemia. Refeeding syndrome is caused by rapid refeeding in PEM, characterized by hypophosphatemia and has metabolic and clinical complications. This is potentially fatal, yet is preventable. Awareness and identification of at-risk patients is crucial to improving management.

  14. Potential Phosphorus Mobilisation in Peat Soils

    DEFF Research Database (Denmark)

    Forsmann, Ditte M.; Kjærgaard, Charlotte

    2012-01-01

    for each location. This mobilisation was measured using intact soil cores (d: 6 cm; h: 15 cm) from the 10 locations set up in an anaerobic closed-flow system. Finally, the hydro- physical parameters like soil-water retention curves, break-through curves, air-filled porosity and bulk density were measured......Re-establishment of wetlands on peat soils containing phosphorus bound to iron(III)-oxides can lead to an undesirable phosphorus loss to the aquatic environment due to the reductive dissolution of iron(III)-oxides. Thus it is important to be able to assess the potential phosphorus mobilisation from...... peat soils before a re-establishment takes place. The potential phosphorus mobilisation from a peat soil depends not only on the geochemical characteristics but also on the redox conditions, the hydrological regime in the area as well as the hydro-physical properties of the soil. The hypothesis...

  15. Phosphorus in antique iron music wire.

    Science.gov (United States)

    Goodway, M

    1987-05-22

    Harpsichords and other wire-strung musical instruments were made with longer strings about the beginning of the 17th century. This change required stronger music wire. Although these changes coincided with the introduction of the first mass-produced steel (iron alloyed with carbon), carbon was not found in samples of antique iron harpsichord wire. The wire contained an amount of phosphorus sufficient to have impeded its conversion to steel, and may have been drawn from iron rejected for this purpose. The method used to select pig iron for wire drawing ensured the highest possible phosphorus content at a time when its presence in iron was unsuspected. Phosphorus as an alloying element has had the reputation for making steel brittle when worked cold. Nevertheless, in replicating the antique wire, it was found that lowcarbon iron that contained 0.16 percent phosphorus was easily drawn to appropriate gauges and strengths for restringing antique harpsichords.

  16. Geochemistry of the Bela Ophiolite, Pakistan

    Science.gov (United States)

    Khan, M.; Nicholson, K. N.; Mahmood, K.

    2008-12-01

    The Bela ophiolite complex of Balochistan, Pakistan has been the subject of several geochemical and tectonic studies in the past. However until now there has never been a combined structural, geochemical and tectonic assimilation study which adequately explains the observed geochemistry and structural geology in a global tectonic framework. Here we present the geochemical findings of our work. The Bela ophiolite complex consists of two major units: the basal section or Lower Unit, and the Upper Unit, between the two is a mélange zone. The Lower Unit is relatively homogeneous and consists almost entirely of flow basalts and pillow basalts. The base of the Upper Unit is the metamorphic sole which is overlain by a sequence of massive basalts flows and intrusions of gabbro and granites. The entire Upper Unit is cut by doleritic dykes and sills. Geochemically the Lower Unit is comprised of basaltic lavas with E-MORB affinities. These lavas are tholeiitic, low-K series lavas with trace element signatures of E-type MORB. For example ratios such as V/Ti, Zr/Y, Nb/Th, Th/La and Nb/U all suggest these lavas are E-MORB. Previous workers have suggested these lavas are back-arc basin (BAB) however the samples lack the characteristic signatures of subduction modified MORB. This conclusion is supported by chondrite and N-MORB normalized spider diagrams where the Lower Unit lavas are enriched in the LILE with respect to the HFSE. The Upper Unit of the Bela Ophiolite sequence has a slightly more complex history. The older lavas sequences, the massive basalt flows, gabbros and granites, all formed in an oceanic arc environment. These lavas exhibit classic arc signatures such as a negative Nb and Ti anomalies, are enriched in LILE and LREE relative to HSFE, and plot in the volcanic arc and island arc fields in classic ternary plots such as 2Nb- Zr/4-Y and Y/15-La/10-Nb/8. The younger sequence of intrusions found in the Bela ophiolite appear to have BAB signatures. These lavas have

  17. Environmental geochemistry at the global scale

    Science.gov (United States)

    Plant, J.; Smith, D.; Smith, B.; Williams, L.

    2000-01-01

    Land degradation and pollution caused by population pressure and economic development pose a threat to the sustainability of the Earth's surface, especially in tropical regions where a long history of chemical weathering has made the surface environment particularly fragile. Systematic baseline geochemical data provide a means of monitoring the state of the environment and identifying problem areas. Regional surveys have already been carried out in some countries, and with increased national and international funding they can be extended to cover the rest of the land surface of the globe. Preparations have been made, under the auspices of the IUGS, for the establishment of just such an integrated global database.

  18. Soil phosphorus constrains biodiversity across European grasslands.

    Science.gov (United States)

    Ceulemans, Tobias; Stevens, Carly J; Duchateau, Luc; Jacquemyn, Hans; Gowing, David J G; Merckx, Roel; Wallace, Hilary; van Rooijen, Nils; Goethem, Thomas; Bobbink, Roland; Dorland, Edu; Gaudnik, Cassandre; Alard, Didier; Corcket, Emmanuel; Muller, Serge; Dise, Nancy B; Dupré, Cecilia; Diekmann, Martin; Honnay, Olivier

    2014-12-01

    Nutrient pollution presents a serious threat to biodiversity conservation. In terrestrial ecosystems, the deleterious effects of nitrogen pollution are increasingly understood and several mitigating environmental policies have been developed. Compared to nitrogen, the effects of increased phosphorus have received far less attention, although some studies have indicated that phosphorus pollution may be detrimental for biodiversity as well. On the basis of a dataset covering 501 grassland plots throughout Europe, we demonstrate that, independent of the level of atmospheric nitrogen deposition and soil acidity, plant species richness was consistently negatively related to soil phosphorus. We also identified thresholds in soil phosphorus above which biodiversity appears to remain at a constant low level. Our results indicate that nutrient management policies biased toward reducing nitrogen pollution will fail to preserve biodiversity. As soil phosphorus is known to be extremely persistent and we found no evidence for a critical threshold below which no environmental harm is expected, we suggest that agro-environmental schemes should include grasslands that are permanently free from phosphorus fertilization.

  19. Possibility in optimization of biological phosphorus removal

    Energy Technology Data Exchange (ETDEWEB)

    Schoenberger, R.

    1989-02-01

    The elimination-efficiency of wastewater treatment plants with biological phosphorus removal is often limited by the following aspects: Low concentrations of organic acids in influent wastewater, hydraulic- and load fluctuations, low anaerobic sludge detention time, transfer of nitrate into the anaerobic zone, phosphorus release in the final clarifier and in sludge treatment units, high effluent suspended solids content. In this context, the following optimization measures seem to be advantageous: 'Activated primary tanks' and 'activated sludge thickeners' are adequate techniques to raise the concentration of organic acids in the wastewater by pre-acidification. Simultaneous acidification takes place in an anaerobic sedimentation basin as realized in the EASC-process (extended anaerobic sludge contact). Below the sludge blanket of an EASC-sedimentation tank, anaerobic conditions can be maintained even in the case of nitrate input. Furthermore, this process is suitable to compensate load- and hydraulic fluctuations of wastewater. To avoid phosphorus release in the final clarifier, it is important to improve sludge settleability. If a low sludge blanket and/or high oxygen concentrations are maintained, phosphorus release in the final clarifier can be limited. Further reduction of total phosphorus is possible with filtration only. Measures against high return flow phosphorus loads are mechanical dewatering of excess sludge and chemical precipitation of digester supernatant.

  20. Recovery of phosphorus from sewerage treatment sludge

    Energy Technology Data Exchange (ETDEWEB)

    Manuilova, Anastasia

    1999-07-01

    This thesis is a review of the current state of technologies for the removal of phosphorus from wastewater and sludge, and the recovery and re-use of phosphorus. It explains the need for phosphorus removal and describes the current removal processes. Focus is given to phosphorus crystallisation processes and to the processes which treat sewage treatment sludges into potential sources of phosphorus. An interesting possibility to recover phosphorus from sewage sludge by use of Psenner fractionation is also discussed. By this method, the following phosphate fractions of technological significance may be distinguished: (1) redox sensitive phosphates, mainly bound to Fe(OH){sub 3}; (2) phosphate adsorbed to surfaces (Al{sub 2}O{sub 3}), exchangeable against OH{sup -}, and alkali-soluble phosphate; (3) phosphate bound to CaCO{sub 3}, MgCO{sub 3} and in apatite; and (4) organically bound phosphate. The basic removal mechanisms, process schemes and treatment results are described. Two experiments with three different types of sludges from Henriksdal wastewater treatment plant in Stockholm were performed in the laboratory. It was shown that the addition of sodium hydroxide or hydrochloric acid cause the significant release of phosphate (about 80%) for all types of sludges. If a whole Psenner fractionation was performed the phosphate release is approximately 100%.

  1. Sulfur Earth

    Science.gov (United States)

    de Jong, B. H.

    2007-12-01

    Variations in surface tension affect the buoyancy of objects floating in a liquid. Thus an object floating in water will sink deeper in the presence of dishwater fluid. This is a very minor but measurable effect. It causes for instance ducks to drown in aqueous solutions with added surfactant. The surface tension of liquid iron is very strongly affected by the presence of sulfur which acts as a surfactant in this system varying between 1.9 and 0.4 N/m at 10 mass percent Sulfur (Lee & Morita (2002), This last value is inferred to be the maximum value for Sulfur inferred to be present in the liquid outer core. Venting of Sulfur from the liquid core manifests itself on the Earth surface by the 105 to 106 ton of sulfur vented into the atmosphere annually (Wedepohl, 1984). Inspection of surface Sulfur emission indicates that venting is non-homogeneously distributed over the Earth's surface. The implication of such large variation in surface tension in the liquid outer core are that at locally low Sulfur concentration, the liquid outer core does not wet the predominantly MgSiO3 matrix with which it is in contact. However at a local high in Sulfur, the liquid outer core wets this matrix which in the fluid state has a surface tension of 0.4 N/m (Bansal & Doremus, 1986), couples with it, and causes it to sink. This differential and diapiric movement is transmitted through the essentially brittle mantle (1024 Pa.s, Lambeck & Johnson, 1998; the maximum value for ice being about 1030 Pa.s at 0 K, in all likely hood representing an upper bound of viscosity for all materials) and manifests itself on the surface by the roughly 20 km differentiation, about 0.1 % of the total mantle thickness, between topographical heights and lows with concomitant lateral movement in the crust and upper mantle resulting in thin skin tectonics. The brittle nature of the medium though which this movement is transmitted suggests that the extremes in topography of the D" layer are similar in range to

  2. Au-bearing magnetite mineralizaion in Kashmar (alteration, mineralization, geochemistry, geochemistry and fluid inclusions;

    Directory of Open Access Journals (Sweden)

    Alireza Almasi

    2017-02-01

    Full Text Available Introduction The study area is located in the central part of the Khaf- Kashmar- Bardaskan volcano-plotunic belt (briefly KKBB. Several IOCG deposits such as Tanourjeh Au-bearing magnetite deposit and Kuh-e-Zar Specularite-rich Au deposit have been explored in KKBB. Geology, alteration, mineralization, geochemistry and fluid inclusion results in Kashmar suggest the IOCG type Au-bearing magnetite mineralization. These IOCG deposits at KKBB form at an active continental arc related to SSZ-type Sabzevar oceanic subduction. Materials and methods Use of Landsat 7+, IRS and Aster satellites. Petrography and alteration Studies in 150 thin sections of volcanic and intrusive rocks. Sampling of ore-bearing quartz vein and mineralography. Preparation of 28 geochemistry samples by the chip composite method of ore-bearing quartz vein and analyzing them in the ACME laboratory by Aqua Regia 1DX1. Fluid inclusions studies of 14 samples of quartz and barite related to the ore minerals of ore-bearing quartz vein by THM600 stage of Linkam company. Results Magmatic events in Kashmar occur at Paleocene-Eocene and include: (1 old mafic - intermediate volcano-plutonic series; (2 felsic volcanic and granitoids; and (3 parallel swarm dykes which are youngest (Almasi et al., 2016. Geochemically, Kashmar rocks are metaluminous to highly peraluminous and Tholeitic to calc-alkaline and shoshonitic in composition (Almasi et al., 2016. The field characteristics, together with isotope and geochemical analyses show that all rock types are essentially co-magmatic and post-collisional I-type (Almasi et al., 2016. Alteration of Kashmar is described in two ways: (1 intense ellipsoidal-linear Argillic-Sillicification and low sericitic with Silica caps and with medium widespread and propylitic alterations in triple regions, next to Dorouneh fault; and (2 Medium Hematite-Carbonate-Chlorite-Silicification alterations in Kamarmard heights. In parts of near the Doruneh fault, sometimes

  3. Plutonium and Americium Geochemistry at Hanford: A Site Wide Review

    Energy Technology Data Exchange (ETDEWEB)

    Cantrell, Kirk J.; Felmy, Andrew R.

    2012-08-23

    This report was produced to provide a systematic review of the state-of-knowledge of plutonium and americium geochemistry at the Hanford Site. The report integrates existing knowledge of the subsurface migration behavior of plutonium and americium at the Hanford Site with available information in the scientific literature regarding the geochemistry of plutonium and americium in systems that are environmentally relevant to the Hanford Site. As a part of the report, key research needs are identified and prioritized, with the ultimate goal of developing a science-based capability to quantitatively assess risk at sites contaminated with plutonium and americium at the Hanford Site and the impact of remediation technologies and closure strategies.

  4. The geochemistry of stable chlorine and bromine isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Eggenkamp, Hans [Onderzock and Beleving, Bussum (Netherlands)

    2014-11-01

    First book solely dedicated to the geochemistry of chlorine and bromine isotopes. Detailed description of analytical techniques, including their advantages and disadvantages. Indication of research fields where measurement of these isotopes is especially useful. This book provides detailed information on the history, analysis and applications of chlorine and bromine isotope geochemistry. Chlorine and bromine are geochemically unique as they prefer to exist as single charged negative ions. For this reason isotope fractionation reflects mostly processes that are not related to changes in the redox state and this fractionation is generally modest. The book will describe the processes that are most easily detected using these isotopes. Also isotope variations, and processes that cause them, measured in oxidised species such as perchlorates and in organic molecules will be described in this book.

  5. Sedimentary basin geochemistry and fluid/rock interactions workshop

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1991-12-31

    Fundamental research related to organic geochemistry, fluid-rock interactions, and the processes by which fluids migrate through basins has long been a part of the U.S. Department of Energy Geosciences program. Objectives of this program were to emphasize those principles and processes which would be applicable to a wide range of problems associated with petroleum discovery, occurrence and extraction, waste disposal of all kinds, and environmental management. To gain a better understanding of the progress being made in understanding basinal fluids, their geochemistry and movement, and related research, and to enhance communication and interaction between principal investigators and DOE and other Federal program managers interested in this topic, this workshop was organized by the School of Geology and Geophysics and held in Norman, Oklahoma in November, 1991.

  6. Phosphorus K4 Crystal: A New Stable Allotrope

    Science.gov (United States)

    Liu, Jie; Zhang, Shunhong; Guo, Yaguang; Wang, Qian

    2016-11-01

    The intriguing properties of phosphorene motivate scientists to further explore the structures and properties of phosphorus materials. Here, we report a new allotrope named K4 phosphorus composed of three-coordinated phosphorus atoms in non-layered structure which is not only dynamically and mechanically stable, but also possesses thermal stability comparable to that of the orthorhombic black phosphorus (A17). Due to its unique configuration, K4 phosphorus exhibits exceptional properties: it possesses a band gap of 1.54 eV which is much larger than that of black phosphorus (0.30 eV), and it is stiffer than black phosphorus. The band gap of the newly predicted phase can be effectively tuned by appling hydrostastic pressure. In addition, K4 phosphorus exibits a good light absorption in visible and near ultraviolet region. These findings add additional features to the phosphorus family with new potential applications in nanoelectronics and nanomechanics.

  7. Estimate of dietary phosphorus intake using 24-h urine collection.

    Science.gov (United States)

    Morimoto, Yuuka; Sakuma, Masae; Ohta, Hiroyuki; Suzuki, Akitsu; Matsushita, Asami; Umeda, Minako; Ishikawa, Makoto; Taketani, Yutaka; Takeda, Eiji; Arai, Hidekazu

    2014-07-01

    Increases in serum phosphorus levels and dietary phosphorus intake induces vascular calcification, arterial sclerosis and cardiovascular diseases. Limiting phosphorus intake is advisable, however, no assessment methods are capable of estimating dietary phosphorus intake. We hypothesized that urinary phosphorus excretion can be translated into estimation of dietary phosphorus intake, and we evaluated whether a 24-h urine collection method could estimate dietary phosphorus intake. Thirty two healthy subjects were recruited for this study. Subjects collected urine samples over 24 h and weighed dietary records. We calculated dietary protein intake and phosphorus intake from dietary records and urine collection, and investigated associations between the two methods in estimating protein and phosphorus intake. Significant positive correlations were observed between dietary records and UC for protein and phosphorus intake. The average intakes determined from dietary records were significantly higher than from urine collection for both protein and phosphorus. There was a significant positive correlation between both the phosphorus and protein difference in dietary records and urine collection. The phosphorus-protein ratio in urine collection was significantly higher than in dietary records. Our data indicated that the 24-h urine collection method can estimate the amount of dietary phosphorus intake, and the results were superior to estimation by weighed dietary record.

  8. The Chemical Evolution of Phosphorus

    CERN Document Server

    Jacobson, Heather R; Frebel, Anna; Roederer, Ian U; Cescutti, Gabriele; Matteucci, Francesca

    2014-01-01

    Phosphorus is one of the few remaining light elements for which little is known about its nucleosynthetic origin and chemical evolution, given the lack of optical absorption lines in the spectra of long-lived FGK-type stars. We have identified a P I doublet in the near-ultraviolet (2135/2136 A) that is measurable in stars of low metallicity. Using archival Hubble Space Telescope-STIS spectra, we have measured P abundances in 13 stars spanning -3.3 <= [Fe/H] <= -0.2, and obtained an upper limit for a star with [Fe/H] ~ -3.8. Combined with the only other sample of P abundances in solar-type stars in the literature, which spans a range of -1 <= [Fe/H] <= +0.2, we compare the stellar data to chemical evolution models. Our results support previous indications that massive-star P yields may need to be increased by a factor of a few to match stellar data at all metallicities. Our results also show that hypernovae were important contributors to the P production in the early universe. As P is one of the ke...

  9. The renaissance of black phosphorus

    Science.gov (United States)

    Ling, Xi; Wang, Han; Huang, Shengxi; Xia, Fengnian; Dresselhaus, Mildred S.

    2015-04-01

    One hundred years after its first successful synthesis in the bulk form in 1914, black phosphorus (black P) was recently rediscovered from the perspective of a 2D layered material, attracting tremendous interest from condensed matter physicists, chemists, semiconductor device engineers, and material scientists. Similar to graphite and transition metal dichalcogenides (TMDs), black P has a layered structure but with a unique puckered single-layer geometry. Because the direct electronic band gap of thin film black P can be varied from 0.3 eV to around 2 eV, depending on its film thickness, and because of its high carrier mobility and anisotropic in-plane properties, black P is promising for novel applications in nanoelectronics and nanophotonics different from graphene and TMDs. Black P as a nanomaterial has already attracted much attention from researchers within the past year. Here, we offer our opinions on this emerging material with the goal of motivating and inspiring fellow researchers in the 2D materials community and the broad readership of PNAS to discuss and contribute to this exciting new field. We also give our perspectives on future 2D and thin film black P research directions, aiming to assist researchers coming from a variety of disciplines who are desirous of working in this exciting research field.

  10. Petrography and Geochemistry of Lunar Meteorite Miller Range 13317

    Science.gov (United States)

    Zeigler, R. A.; Korotev, R. L.

    2016-01-01

    Miller Range (MIL) 13317 is a 32-g lunar meteorite collected during the 2013-2014 ANSMET (Antarctic Search for Meteorites) field season. It was initially described as having 25% black fusion crust covering a light- to dark-grey matrix, with numerous clasts ranging in size up to 1 cm; it was tenta-tively classified as a lunar anorthositic breccia. Here we present the petrography and geochemistry of MIL 13317, and examine possible pairing relationships with previously described lunar meteorites.

  11. Soil phosphorus availability and soybean response to phosphorus starter fertilizer

    Directory of Open Access Journals (Sweden)

    Ciro Antonio Rosolem

    2014-10-01

    Full Text Available Phosphorus fixation in tropical soils may decrease under no-till. In this case, P fertilizer could be surface-spread, which would improve farm operations by decreasing the time spend in reloading the planter with fertilizers. In the long term, less soluble P sources could be viable. In this experiment, the effect of surface-broadcast P fertilization with both soluble and reactive phosphates on soil P forms and availability to soybean was studied with or without fertilization with soluble P in the planting furrow in a long-term experiment in which soybean was grown in rotation with Ruzigrass (Brachiaria ruziziensis. No P or 80 kg ha-1 of P2O5 in the form of triple superphosphate or Arad reactive rock phosphate was applied on the surface of a soil with variable P fertilization history. Soil samples were taken to a depth of 60 cm and soil P was fractionated. Soybean was grown with 0, 30, and 60 kg ha-1 of P2O5 in the form of triple phosphate applied in the seed furrow. Both fertilizers applied increased available P in the uppermost soil layers and the moderately labile organic and inorganic forms of P in the soil profile, probably as result of root decay. Soybean responded to phosphates applied on the soil surface or in the seed furrow; however, application of soluble P in the seed furrow should not be discarded. In tropical soils with a history of P fertilization, soluble P sources may be substituted for natural reactive phosphates broadcast on the surface. The planting operation may be facilitated through reduction in the rate of P applied in the planting furrow in relation to the rates currently applied.

  12. Hydrology and isotope geochemistry; Hydrologie et geochimie isotopique

    Energy Technology Data Exchange (ETDEWEB)

    Causse, Ch.; Gasse, F

    1998-12-31

    This book gathers recent works in hydrology and isotopic geochemistry. Part I exposes the general water cycle, from precipitations to deep aquifers, through the analysis of hydrogen, oxygen and carbon isotopic composition. Regional types are laid out from high latitudes (Spitzberg), through temperate regions (Parisian Basin), to the tropics (the Soudanian-Sahelian Niger Basin). The significance of isotopic techniques for Global Change analysis in shown in part II. Several case studies, mainly in Africa, reconstruct the hydro-climatic history through the pluri-proxy analysis of sediment profiles, where isotopic geochemistry is key. The last glacial maximum cooling is shown to have been homogeneous throughout middle and low latitudes, based upon noble gases isotopic analysis in groundwaters. The interpretation of some isotopic analysis could sometimes be questionable due to the organic origin of carbon in some sedimented carbonates. Part III refers to isotopes of cosmic origin and to in situ production of radionuclides. {sup 14}C dating is reminded to have contributed to our understanding of climate change mechanisms during the last glacial and post-glacial periods. Both the limitations and the recent improvements in this methodology are highlighted in a well documented synthesis. Isotopic data enable geochemistry to be the base for modelling stability conditions in the Oklo natural fossil nuclear fission reactor. (author)

  13. Production of Low-Phosphorus Molten Iron from High-Phosphorus Oolitic Hematite Using Biomass Char

    Science.gov (United States)

    Tang, Huiqing; Qi, Tengfei; Qin, Yanqi

    2015-09-01

    In this study, an energy-saving and environmentally friendly method to produce low-phosphorus molten iron from high-phosphorus oolitic hematite was experimentally investigated and theoretically analyzed. The results indicate that biomass char is a suitable reducing agent for the proposed method. In the direct reduction stage, the ore-char briquette reached a metallization degree of 80-82% and a residual carbon content of 0.1-0.3 mass%. Under the optimized condition, phosphorus remained in the gangue as calcium phosphate. In the melting separation stage, phosphorus content ([%P]) in molten iron could be controlled by introducing a Na2CO3 additive, and the phosphorus behavior could be predicted using ion molecular coexistence theory. Molten iron with [%P] less than 0.3 mass% was obtained from the metallic briquettes with the aforementioned quality by introducing 2-4% Na2CO3 and the iron recovery rate was 75-78%.

  14. The Dark Side of the Earth

    Science.gov (United States)

    Frankel, Henry

    1986-10-01

    Wood's The Dark Side of the Earth is another addition to the growing list of books on the recent revolution in the earth sciences. Wood rightly points out that any new book on the topic should break new ground. In the preface, he writes of himself and his book that he has benefited from previous accounts by saving himself research time, and that his book, unlike others, “attempts to tell one complete story of the study of the Earth, geologists, geophysicists, dreamers and all” (p. vi). Wood is ambitious, for his work covers much of 19th-century geology as well as the development, reception, rejection, and eventual acceptance of mobilist ideas. Before discussing the work of the German meteorologist and geophysicist Alfred L. Wegener, American glacial geomorphologist Frank Taylor, and several of their predecessors who proposed “mobilist” ideas, he manages to string together brief descriptions of the contributions of (among others) German mineralogist Abraham Gottlob Werner, British geologists James Hutten and John Playfair, British engineer William Smith, British geologist Charles Lyell, American geologists James Hall and James Dwight Dana, British volcanologist William Lowthian Green, American geologist Grove Karl Gilbert, French geologist Elie de Beaumont, British geologist and mathematician Osmond Fisher, American geologist Clarence Dutton, British mathematician and physicist Lord Kelvin, Austrian geologist Eduard Suess, French geologist Marcel Bertrand, and American geologist Thomas Chrowder Chamberlin. Moreover, Wood offers an interesting thesis about the revolution in the earth sciences. He claims that the real revolution was not the replacement of fixist views with the mobilist ones of sea floor spreading and plate tectonics, but rather the replacement of geology with the new discipline of the earth sciences in which geophysics and geochemistry play the central role.

  15. Geochemistry of some rare earth elements in groundwater, Vierlingsbeek, the Netherlands

    NARCIS (Netherlands)

    Janssen RPT; Verweij W; Versteegh JFM; LWD

    1997-01-01

    In de nabijheid van het drinkwaterpompstation Vierlingsbeek zijn uit zeven boorputten grondwatermonsters op verschillende diepten genomen. Speciatieberekeningen zijn uitgevoerd om meer inzicht te krijgen in de chemische processen van zeldzame aarden (REE). Bij de modellering is rekening gehouden m

  16. Ferromanganese nodules and their associated sediments from the Central Indian Ocean Basin: Rare earth element geochemistry

    Digital Repository Service at National Institute of Oceanography (India)

    Pattan, J.N.; Rao, Ch.M.; Migdisov, A.A.; Colley, S.; Higgs, N.C.; Demidenko, L.

    in the nodules are carried by Fe, P, and Ti, whereas in the sediment they are carried by P and Mn phases. A similar REE fractionation pattern with middle REE enrichment over heavy and light REE in both the nodules and their associated sediment suggest...

  17. Rare earth element geochemistry of ferromanganese deposits of the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Nath, B.N.; Balaram, V.; Sudhakar, M.; Pluger, W.L.

    and the shallower depths of the Central Indian Basin are delta -MnOd2 rich, and are characterizEd. by high concentrations of REE and higher positive cerium anomalies. These two areas are in the realm of cold Antarctic Bottom Water (AABW), which may enhance...

  18. Geochemistry of Rare Earth Elements in Xikeng Ag-Pb-Zn Ore Deposit, South Anhui, China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper, a comparative study is done on the geochemical charateristics of REE in ore, ore-hosted rocks of Lantian group, granite related to ore deposit, and altered rocks for tracing origin of ore-forming materials. The result indicates that the ore-forming fluid and ore-forming materials for Xikeng silver-polymetallic ore deposit were derived from Yixian granite's magmatic activity. Water-rock reaction of the hydrothermal fluid with the carbonate-rich stratum led the altered rock to relatively enrich in HREE.

  19. Rare earth element mineralogy and geochemistry in a laterite profile from Madagascar

    DEFF Research Database (Denmark)

    Berger, Alfons; Janots, Emilie; Gnos, Edwin

    2014-01-01

    group minerals in cracks and pores. The presence of sulfate ligands, produced by sulfide oxidation, may be responsible for the REE speciation, as suggested by the composition of the secondary REE-minerals. Rhabdophane group minerals contain up to 9 wt% SO3 and 7 wt% CaO, indicating a mixture between...... rhabdophane sensu stricto, (REE)PO4·H2O, and tristamite, (Ca,U,Fe(III))(PO4,SO4)·2H2O. Due to intense Ca-leaching, rhabdophane disappears and Al-phosphates (alunite–jarosite group) are found in the soil. Cerianite (Ce(IV)O2) also precipitates in the B-horizon of the soil. Mass transfer calculations based...

  20. Rare Earth Elements Geochemistry of Dongtian Gold Deposit in Western Guangdong

    Institute of Scientific and Technical Information of China (English)

    曹建劲

    2003-01-01

    Yunkai uplifted area is one of the important metallogenic areas in Guangdong and Guangxi Provinces, in which many gold, silver, tungsten, tin, lead, zinc, molybdenum, and iron deposits were found. Dongtian gold deposit in the middle of Yunkai uplifted area, western Guangdong Province, is chosen as an example of those deposits. Comparative studies on the chondrite-normalized REE patterns and ΣREE, LREE/HREE, δEu, δCe, NLa/Yb, and NLa/Sm of auriferous quartz veins, altered gneiss-type gold ores, Caledonian gneissic biotite granite, and Late Yanshanian granite porphyry were made. The results indicate that the source of the metallogenic materials of the auriferous quartz veins and the altered gneiss-type gold ores are the same, and both of them come from the gneissic biotite granite. Metallogenic epoch of the deposit is estimated to be Caledonian period.

  1. Aqueous geochemistry of the rare earth elements in marine anoxic basins

    NARCIS (Netherlands)

    Schijf, J.

    1992-01-01

    Life in the oceans mainly occurs in the upper tens of meters of the watercolumn, where sunlight penetrates. This sunlight is used by phytoplankton to combine carbon and nutrients to organic matter, which subsequently serves zooplankton and higher life forms as food. When the plankton dies it slowly

  2. Earth's evolving subcontinental lithospheric mantle: inferences from LIP continental flood basalt geochemistry

    Science.gov (United States)

    Greenough, John D.; McDivitt, Jordan A.

    2017-06-01

    Archean and Proterozoic subcontinental lithospheric mantle (SLM) is compared using 83 similarly incompatible element ratios (SIER; minimally affected by % melting or differentiation, e.g., Rb/Ba, Nb/Pb, Ti/Y) for >3700 basalts from ten continental flood basalt (CFB) provinces representing nine large igneous provinces (LIPs). Nine transition metals (TM; Fe, Mn, Sc, V, Cr, Co, Ni, Cu, Zn) in 102 primitive basalts (Mg# = 0.69-0.72) from nine provinces yield additional SLM information. An iterative evaluation of SIER values indicates that, regardless of age, CFB transecting Archean lithosphere are enriched in Rb, K, Pb, Th and heavy REE(?); whereas P, Ti, Nb, Ta and light REE(?) are higher in Proterozoic-and-younger SLM sources. This suggests efficient transfer of alkali metals and Pb to the continental lithosphere perhaps in association with melting of subducted ocean floor to form Archean tonalite-trondhjemite-granodiorite terranes. Titanium, Nb and Ta were not efficiently transferred, perhaps due to the stabilization of oxide phases (e.g., rutile or ilmenite) in down-going Archean slabs. CFB transecting Archean lithosphere have EM1-like SIER that are more extreme than seen in oceanic island basalts (OIB) suggesting an Archean SLM origin for OIB-enriched mantle 1 (EM1). In contrast, OIB high U/Pb (HIMU) sources have more extreme SIER than seen in CFB provinces. HIMU may represent subduction-processed ocean floor recycled directly to the convecting mantle, but to avoid convective homogenization and produce its unique Pb isotopic signature may require long-term isolation and incubation in SLM. Based on all TM, CFB transecting Proterozoic lithosphere are distinct from those cutting Archean lithosphere. There is a tendency for lower Sc, Cr, Ni and Cu, and higher Zn, in the sources for Archean-cutting CFB and EM1 OIB, than Proterozoic-cutting CFB and HIMU OIB. All CFB have SiO2 (pressure proxy)-Nb/Y (% melting proxy) relationships supporting low pressure, high % melting resembling OIB tholeiites, but TM concentrations do not correlate with % melting. Thus, the association of layered intrusion (plutonic CFB) TM deposits with Archean terranes does not appear related to higher metal concentrations or higher percentages of melting in Archean SLM. Other characteristics of these EM1-like magmas (e.g., S2 or O2 fugacity) may lead to element scavenging and concentration during differentiation to form ore deposits.

  3. Aqueous geochemistry of the rare earth elements in marine anoxic basins

    NARCIS (Netherlands)

    Schijf, J.

    1992-01-01

    Life in the oceans mainly occurs in the upper tens of meters of the watercolumn, where sunlight penetrates. This sunlight is used by phytoplankton to combine carbon and nutrients to organic matter, which subsequently serves zooplankton and higher life forms as food. When the plankton dies it

  4. Kinetic analysis of anaerobic phosphorus release during biological phosphorus removal process

    Institute of Scientific and Technical Information of China (English)

    DOU Junfeng; LUO Guyuan; LIU Xiang

    2007-01-01

    Enhanced biological phosphorus removal(EBPR)is a commonly used and sustainable method for phosphorus removal from wastewater.Poly-β-hydroxybutyrate(PHB),polyphosphate,and glycogen are three kinds of intracellular storage polymers in phosphorus accumulation organisms.The variation of these polymers under different conditions has an apparent influence on anaerobic phosphorus release,which is very important for controlling the performance of EBPR.To obtain the mechanism and kinetic character of anaerobic phosphorus release,a series of batch experiments were performed using the excessively aerated sludge from the aerobic unit of the biological phosphorus removal system in this study.The results showed that the volatile suspended solid(vss)had an increasing trend,while the mixed liquid suspended sludge(MLSS)and ashes were reduced during the anaerobic phosphorus release process.The interruption of anaerobic HAc-uptake and phosphorus-release occurs when the glycogen in the phosphorus-accumulating-organisms is exhausted.Under the condition of lower initial HAc-COD,HAc became the limiting factor after some time for anaerobic HAc uptake.Under the condition of higher initial HAc-COD,HAc uptake was stopped because of the depletion of glycogen in the microorganisms.The mean ratio of △ρP/△ρPHB,△ρGLY/△ρPHB,△ρP/△COD,and △ρPHB/△COD was 0.48,0.50,0.44.and 0.92.respectively,which was nearly the same as the theoretical value.The calibrated kinetic parameters of the HAc-uptake and phosphorus-release model were evaluated as Kgly was 0.005,and KCOD was 3 mg/L.An apparently linear correlation was observed between the ratio of △ρP/△COD and pH of the solution,and the equation between them was obtained in this study.

  5. Critical phosphorus concentrations in winter wheat genotypes with various phosphorus efficiencies

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Under greenhouse conditions, a pot experiment was conducted to seek critical phosphorus concentrations of wheat genotypes with high and low phosphorus use efficiency. Results indicated that low efficient genotype was much more sensitive to phosphorus deficiency, with low or without phosphorus application, seed yield and dry matter of biomass were much lower. The yield of all the genotypes gradually got higher as application rate increased, but high efficient genotype--Lofflin produced relatively higher yields of seeds and biomass with low or without phosphorus input. Highly tolerate to low availability of soil phosphorus and efficient activation and absorption for soil unavailable phosphorus had been displayed. As application rates increased, yields of both genotypes were increased but high efficient genotype maintained stable while low efficient one showed continuously increase with remuneration decrease progressively. Critical phosphorus concentrations in high efficient genotypes of winter wheat were lower than that in low efficient ones and changed with various development stages, for example, at seedling state, the concentrations of high efficient genotype were 4.50-4.60 g/kg while low efficient one was 5.0 g/kg. They were 2.25-2.30 g/kg and 2.52 g/kg at flower stage, 1.96-2.05 g/kg and 2.15 g/kg at maturity respectively. But the values in seeds were reversal, higher in high efficient genotype(4.05-4.10 g/kg) than that in low efficient(3.90 g/kg). Therefore, phosphorus high efficient genotypes belong to the phosphorus resource saving type.

  6. 40 CFR 422.10 - Applicability; description of the phosphorus production subcategory.

    Science.gov (United States)

    2010-07-01

    ... phosphorus production subcategory. 422.10 Section 422.10 Protection of Environment ENVIRONMENTAL PROTECTION... Phosphorus Production Subcategory § 422.10 Applicability; description of the phosphorus production... production of phosphorus and ferrophosphorus by smelting of phosphate ore....

  7. Long-term agricultural non-point source pollution loading dynamics and correlation with outlet sediment geochemistry

    Science.gov (United States)

    Ouyang, Wei; Jiao, Wei; Li, Xiaoming; Giubilato, Elisa; Critto, Andrea

    2016-09-01

    Some agricultural non-point source (NPS) pollutants accumulate in sediments in the outlet sections of watersheds. It is crucial to evaluate the historical interactions between sediment properties and watershed NPS loading. Therefore, a sediment core from the outlet of an agricultural watershed was collected. The core age was dated using the 210Pb method, and sedimentation rates were determined using the constant rate of supply (CRS) model. The total nitrogen (TN), total phosphorus (TP), Cd, Pb, Cu, Ni and Cr accumulations in the sediment generally showed fluctuating increases, with the highest sedimentation fluxes all occurring in approximately 1998. The measurement of specific mass sedimentation rates reflected a record of watershed soil erosion dynamics. Using SWAT (Soil and Water Assessment Tool) to simulate long-term watershed agricultural NPS pollution loadings, the historical interactions between sediment properties and NPS loadings were further evaluated. The N leaching process weakened these interactions, but the historical accumulations of TP and heavy metals in sediments generally correlated well with watershed NPS TP loading. The regression analysis suggested that Pb and Cr were the most suitable indexes for assessing long-term NPS TN and TP pollution, respectively. Assessing the NPS loading dynamics using the vertical characteristics of sediment geochemistry is a new method.

  8. Geology, mineralogy and geochemistry of Ferezneh ferromanganese anomaly, east of Sangan mines complex, NE Iran

    Directory of Open Access Journals (Sweden)

    Nazi Mazhari

    2015-04-01

    stratabound in recrystallized limestone that followed the structure pattern. Iron oxides often include goethite and hematite; while manganese oxides are pyrolusite, psilomelane and lesser amounts of cryptomelane. Small spots of rutile are rarely seen. The gangue minerals are dolomite, calcite and cryptocrystalline quartz. XRD analysis shows that iron and manganese oxides are the only metallic minerals. The geochemistry of mineralization was studied by ICP-MS and XRF analysis for major oxides, trace elements and REE. The range of Fe anomaly changes from 43.5 to 68% and Mn anomalies vary between 1.9 and 4.8 %. The range of Cu varies from 20 to 1063 ppm and the range of As differs between 20 and 1269 ppm, no Cu and As mineralization has been observed. Mn and Fe oxides uptake trace elements. In the Fe:Mn:Si ternary diagram, ten of the analyzed samples were plotted in the characteristic compositional field for Fe-rich hydrothermal. In the Fe:Mn:(Co+Ni+Cu×10 ternary diagram, data were also plotted in hydrothermal fields. Minor and trace elements in the binary diagram of Ni+Co vs. Cu+Zn+Pb+Mo+V+As (Crerar et al., 1982 show samples within the field for hydrothermal deposits. REE pattern shows positive Eu anomaly and the Eu/Eu* ratio changes from 2 to 7, LREE/HREE ratio varies between 2.25 and 13.78, the mean being 6.94. Rare earth element contents show relatively low to moderate subtraction pattern. LREE have more variations than HREE values that have been fixed. Enrichment of LREE over HREE and positive Eu anomaly, are the key indications of hydrothermal origin for the ore deposits and low amounts of REE are the characteristic for hydrothermal deposits (Xu Bao et al., 2008. As, Cu, Pb, Zn and Sb act as trace indicator elements in reaching the hidden epithermal or hydrothermal sulfide deposit in depth. Although the type of mineralization in the main parts of Sangan is skarn (Karimpour and Malekzadeh Shafaroudi, 2006; Karimpour and Malekzadeh Shafaroudi, 2008; Golmohammadi et al

  9. Secondary poisoning of kestrels by white phosphorus

    Science.gov (United States)

    Sparling, D.W.; Federoff, N.E.

    1997-01-01

    Since 1982, extensive waterfowl mortality due to white phosphorus (P4) has been observed at Eagle River Flats, a tidal marsh near Anchorage, Alaska. Ducks and swans that ingest P4 pellets become lethargic and may display severe convulsions. Intoxicated waterfowl attract raptors and gulls that feed on dead or dying birds. To determine if avian predators can be affected by secondary poisoning, we fed American kestrels (Falco sparverius) 10-day-old domestic chickens that had been dosed with white phosphorus. Eight of 15 kestrels fed intact chicks with a pellet of P4 implanted in their crops died within seven days. Three of 15 kestrels fed chicks that had their upper digestive tracts removed to eliminate any pellets of white phosphorus also died. Hematocrit and hemoglobin in kestrels decreased whereas lactate dehydrogenaseL, glucose, and alanine aminotransferase levels in plasma increased with exposure to contaminated chicks. Histological examination of liver and kidneys showed that the incidence and severity of lesions increased when kestrels were fed contaminated chicks. White phosphorus residues were measurable in 87% of the kestrels dying on study and 20% of the survivors. This study shows that raptors can become intoxicated either by ingesting portions of digestive tracts containing white phosphorus pellets or by consuming tissues of P4 contaminated prey.

  10. 镧系元素地球化学效应的一个重要应用——以稀土元素的岩石分类和煤燃烧中的迁移富集过程为例%The effect on geochemistry of the Rare Earth Element: an example of important application in the REE classification for petrology and study for migrating of the REE during the burning of lignite

    Institute of Scientific and Technical Information of China (English)

    杨建业

    2011-01-01

    Form the point of effect on geochiemistry of the REE, the REE distribution of sandstone, coal form ZKA183 - 87 drilling of Dongsheng in Orduos Basin and REE migration law in different ways of buming of lignite which form Xiaolongtan mine in Yunnan, Province were studied by using the date were published. The result shows that, in the REE distribution types of sandstone and coal consistent with previous findings on, at the same time, a new idea about the REE migration duing buming of lignite is put forwarded : whatever the form of combustion, it is same migating way for HREE from lignite to fly and bottom ashes; howere, LREE ,which migrating from lignite to fly and bottom ashes ,is compliant about affected by different combustion: Pulverized coal combustion in power plant, the the larger ionic radius of LREE, the more enriched the fly ash while the larger ionic radius of HREE,the more enriched the bottom ash , and it is easily affected by the combustion of lignite and its burning temperature for REE distribution to fly and bottom ashes in two staged combustion or two non - staged combustion. this study shows that effect on geochemistry of REE, as a new study method, is effective in study REE mode of distribution of various types of geological and it complement the traditional methods for geochemistry of REE.%从镧系元素地球化学效应的角度,探讨了鄂尔多斯盆地东胜ZKA183-87钻孔中砂岩、煤的稀土分布类型和云南小龙潭矿区褐煤不同燃烧方式下的稀土元素迁移和富集规律.研究结果表明,砂岩、煤的稀土分布类型与前人研究结论基本致.发现褐煤燃烧时稀土元素的迁移和富集具有以下特征:无论哪种燃烧方式,褐煤中HREE均以同一种模式向飞灰和底灰中迁移;而LREE向飞灰、底灰迁移富集过程中则要受到燃烧方式的影响,不同的燃烧方式对其迁移模式影响较大;电厂粉煤燃烧时,愈是大离子LREE,愈趋于向飞灰相对富集,愈是大

  11. Environmental geochemistry and ecological risk of vanadium pollution in Panzhihua mining and smelting area, Sichuan, China

    Institute of Scientific and Technical Information of China (English)

    TENG Yanguo; NI Shijun; ZHANG Chengjiang; WANG Jinsheng; LIN Xueyu; HUANG Yi

    2006-01-01

    Vanadium is a trace element widely distributed in the Earth's crust. Naturally high levels of vanadium are recognized mainly in basic rocks and minerals, particularly in titaniferous magnetite. And the anthropogenic sources of vanadium include fossil fuel combustion and wastes including steel-industry slags. In the last few years, the authors have made investigations and assessments on the environmental geochemistry and ecological risk of vanadium in the Panzhihua mining and smelting area. In the study area, anthropogenic vanadium resulted from mining, extracting and smelting of V-Ti magnetite; vanadium pollution of topsoil and sediments occurs mainly in the mining and extracting area, smelting area, slag dumping area, tailing dam and coal mining area. In the soil, the chemical speciation of vanadium shows: insoluble residue>organically bound>Fe (amorphous) oxide-bound>Mn oxide-bound>soluble component. Vanadium pollution can cause potential harmful effects on ecological systems, and lead to animal poisoning and human disease. So vanadiam pollution should be monitored on a regular basis in the Panzhihua area.

  12. Geochronology and Geochemistry of the Middle Proterozoic Aoyougou Ophiolite in the North Qilian Mountains, Northwestern China

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The Aoyougou ophiolite lies in an early Palaeozoic orogenic belt of the western North Qilian Mountains, near the Aoyougou valley in Gansu Province, northwestern China. It consists of serpentinite, a cumulate sequence of gabbro and diorite, pillow and massive lavas, diabase and chert. Ages of 1840±2 Ma, 1783±2 Ma and 1784±2 Ma on three zircons from diabase, indicate an early Middle Proterozoic age. The diabases and basalts show light rare-earth element enrichment and have relatively high TiO2 contents, characteristic of ocean island basalts. All of the lavas have low MgO, Cr, Ni contents and Mg numbers indicating a more evolved character. They are believed to have been derived from a more mafic parental magma by fractionation of olivine, Cr-spinel and minor plagioclase. Based on the lava geochemistry and regional geology, the Aoyougou ophiolite was probably believed to have formed at a spreading centre in a small marginal basin. Subduction of the newly formed oceanic lithosphere in the Middle Proterozoic produced a trench-arc-basin system, which is preserved in the North Qilian Mountains.

  13. (De)Constructing the Undergraduate Research Experience in an Environmental Geochemistry Lab (Invited)

    Science.gov (United States)

    Kim, C. S.

    2013-12-01

    Maintaining a productive research lab at the undergraduate level requires a savvy combination of internal organization, high (but realistic) expectations, and adaptation of one's research interests into semester- and summer-length projects. Several key strategies can help achieve the goal of building a lab culture that both enriches students' academic experiences and advances one's own scholarly research and visibility. Foremost among these is the need to maintain momentum and preserve institutional knowledge in an environment where undergraduate students' lifetime in an individual lab may only last a year or two. Examples from the Environmental Geochemistry Lab at Chapman University (www.chapman.edu/envgeo) developed over several years and with 40+ undergraduate students will be presented which can be transferable to other faculty research labs in the earth sciences. Approaches to writing successful external research grant proposals at a primarily undergraduate institution (PUI) and strategies for both personal and institutional time management/savings will also be discussed, with a focus on new models at Chapman offered to further incentivize faculty involvement in undergraduate research.

  14. Geochemistry of the barkinite liptobiolith (Late Permian) from the Jinshan Mine, Anhui Province, China.

    Science.gov (United States)

    Sun, Yuzhuang; Lin, Mingyue; Qin, Peng; Zhao, Cunliang; Jin, Kankun

    2007-02-01

    This paper discusses the geochemistry and mineralogy of the barkinite liptobiolith of the Late Permian age from the Jinshan Mine, Guangde County, Anhui Province, China. Samples were examined using inductively coupled plasma-mass spectroscopy, X-ray fluorescence, cold-vapor atomic absorption spectrometry, ion-selective electrode, sequential chemical extraction, scanning electron microscopy equipped with energy-dispersive X-ray, and optical microscopy. The coal is a medium-ash and high-sulfur resource. Minerals in the coal are composed of kaolinite, pyrite, calcite, and quartz. Pyrite and calcite are derived from seawater during peat accumulation. Quartz in the coal is of authigenic origin. Part of the kaolinite is from a land-source region, and part occurs as cell-fillings and is of authigenic origin. The results also indicate that the barkinite liptobiolith contains some toxic elements in high concentrations. Elements including Li, Be, Si, Sc, Ti, V, Cr, Fe, Ga, Se, Y, Zr, Mo, the rare earth elements (REEs), W, Hg, Tl, Pb, Th, and U in the coals are enriched in the barkinite liptobiolith. Results of sequential chemical extraction showed that Li, Sc, Ti, Cr, Y, Zr, REEs, and Th in the coal mainly occur as silicates, while Be and W are related to organic matter. Pyrite is the dominant source of S, Mo, Hg, Tl, and Pb. Gallium only occurs in silicate, and U and V occur both in organic and silicate associations.

  15. Iron and titanium geochemistry for paleoclimate reconstruction from Talos Dome ice core (East Antarctica)

    Science.gov (United States)

    Maggi, Valter; Marcelli, Augusto; Hampai, Dariush; Cibin, Giannantonio; Delmonte, Barbara; Baccolo, Giovanni

    2015-04-01

    Mineral dust affects the Earth's radiation budget. It can both scatter sunlight back to space (negative radiative forcing) and absorb solar and infrared radiation (positive forcing). Thus, in opposition to the greenhouse gases, the combination of absorption and reflection of solar radiation caused by dust microparticles can lead to a net (longwave and shortwave) negative radiative forcing at the surface and at the top of atmosphere. Transported from the Southern Hemisphere continental landmasses to the remote East Antarctic plateau (long-term transport), mineral dust travels in the high troposphere and interacts with climate. However, processes occurring during atmospheric transport from source areas to polar ice sheets are responsible for the strong reduction of dust concentration and size in the polar atmosphere. Moreover, concentration and grain size, such as mineralogy and shape of dust and aerosols, influencing the dust radiative effect are still poorly known. We present here new Synchrotron radiation spectroscopy data, i.e., X-ray Absorption Near Edge Structure (XANES) at the Fe and Ti K edge from Talos Dome dust samples (72°49'S, 159°110'E; 2315 m a.s.l.) spanning the last two climate cycles (ca. 250 kyrs). The analysis allows the reconstruction of dust geochemistry and Fe and Ti coordination state in selected climatic periods. Dust composition changes in time provide an important contribution to the scientific knowledge on palaeoclimate changes in near coastal regions of the Antarctic ice sheet and novel information on possible changes occurred at the source areas.

  16. Geochemistry of the barkinite liptobiolith (Late Permian) from the Jinshan Mine, Anhui Province, China

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Y.Z.; Lin, M.Y.; Qin, P.; Zhao, C.L.; Jin, K.K. [Hebei University of Engineering, Handan (China)

    2007-02-15

    This paper discusses the geochemistry and mineralogy of the barkinite liptobiolith of the Late Permian age from the Jinshan Mine, Guangde County, Anhui Province, China. Samples were examined using inductively coupled plasma-mass spectroscopy, X-ray fluorescence, cold-vapor atomic absorption spectrometry, ion-selective electrode, sequential chemical extraction, scanning electron microscopy equipped with energy-dispersive X-ray, and optical microscopy. The coal is a medium-ash and high-sulfur resource. Minerals in the coal are composed of kaolinite, pyrite, calcite, and quartz. Pyrite and calcite are derived from seawater during peat accumulation. Quartz in the coal is of authigenic origin. Part of the kaolinite is from a land-source region, and part occurs as cell-fillings and is of authigenic origin. The results also indicate that the barkinite liptobiolith contains some toxic elements in high concentrations. Elements including Li, Be, Si, Sc, Ti, V, Cr, Fe, Ga, Se, Y, Zr, Mo, the rare earth elements (REEs), W, Hg, Tl, Pb, Th, and U in the coals are enriched in the barkinite liptobiolith. Results of sequential chemical extraction showed that Li, Sc, Ti, Cr, Y, Zr, REEs, and Th in the coal mainly occur as silicates, while Be and W are related to organic matter. Pyrite is the dominant source of S, Mo, Hg, Tl, and Pb. Gallium only occurs in silicate, and U and V occur both in organic and silicate associations.

  17. Response of Sugarcane in a Red Ultisol to Phosphorus Rates, Phosphorus Sources, and Filter Cake

    Science.gov (United States)

    Prado, Renato de Mello; Campos, Cid Naudi Silva; Rosatto Moda, Leandro; de Lima Vasconcelos, Ricardo; Pizauro Júnior, João Martins

    2015-01-01

    We evaluated the effect of phosphorus application rates from various sources and in the presence or absence of filter cake on soil phosphorus, plant phosphorus, changes in acid phosphatase activity, and sugarcane productivity grown in Eutrophic Red Ultisol. Three P sources were used (triple superphosphate, Araxa rock phosphate, and Bayovar rock phosphate) and four application rates (0, 90, 180, and 360 kg ha−1 of P2O5) in the presence or absence of filter cake (7.5 t ha−1, dry basis). The soil P, the accumulated plant P, the leaf acid phosphatase activity and straw, the stalk productivity, the concentration of soluble solids in the juice (Brix), the juice sucrose content (Pol), and the purity were the parameters evaluated. We found that P applications increased levels of soil, leaf, and juice phosphorus and led to higher phosphorus accumulation and greater stalk and straw productivity. These levels were highest in the presence of filter cake. Acid phosphatase activity decreased with increasing plant phosphorus concentration. Phosphate fertilization did not show effect on sugarcane technological quality. We concluded that P application, regardless of source, improved phosphorus nutrition and increased productivity in sugarcane and, when associated with filter cake, reduced the need for mineral fertilizer. PMID:26078993

  18. Effect of phosphorus-ion implantation on the corrosion resistance and biocompatibility of titanium.

    Science.gov (United States)

    Krupa, D; Baszkiewicz, J; Kozubowski, J A; Barcz, A; Sobczak, J W; Biliński, A; Lewandowska-Szumieł, M; Rajchel, B

    2002-08-01

    This work presents data on the structure and corrosion resistance of titanium after phosphorus-ion implantation with a dose of 10(17)P/cm2. The ion energy was 25keV. Transmission electron microscopy was used to investigate the microstructure of the implanted layer. The chemical composition of the surface layer was examined by X-ray photoelectron spectroscopy and secondary ion mass spectrometry. The corrosion resistance was examined by electrochemical methods in a simulated body fluid at a temperature of 37 C. Biocompatibility tests in vitro were performed in a culture of human derived bone cells in direct contact with the materials tested. Both, the viability of the cells determined by an XTT assay and activity of the cells evaluated by alkaline phosphatase activity measurements in contact with implanted and non-implanted titanium samples were detected. The morphology of the cells spread on the surface of the materials examined was also observed. The results confirmed the biocompatibility of both phosphorus-ion-implanted and non-implanted titanium under the conditions of the experiment. As shown by transmission electron microscope results, the surface layer formed during phosphorus-ion implantation was amorphous. The results of electrochemical examinations indicate that phosphorus-ion implantation increases the corrosion resistance after short-term as well as long-term exposures.

  19. A leaf phosphorus assay for seedlings of Acacia mangium.

    Science.gov (United States)

    Sun, J S; Simpson, R J; Sands, R

    1992-10-01

    Concentrations of extractable and total phosphorus in leaves, stem, root and nodules of 12-week-old seedlings of two provenances of Acacia mangium Willd. were analyzed to identify the fraction of phosphorus and the plant part most suitable for predicting the phosphorus nutritional status of the seedlings.For both provenances, concentrations of extractable phosphorus were more sensitive to changes in soil phosphorus status and varied less among different plant parts than concentrations of total phosphorus. Concentrations of extractable phosphorus in the youngest fully expanded leaf (Leaf 3 from the apex) and the next two older leaves correlated closely with seedling dry mass and may be used to assess the phosphorus nutritional status of Acacia mangium seedlings.

  20. Bioretention column studies of phosphorus removal from urban stormwater runoff.

    Science.gov (United States)

    Hsieh, Chi-hsu; Davis, Allen P; Needelman, Brian A

    2007-02-01

    This study investigated the effectiveness of bioretention as a stormwater management practice using repetitive bioretention columns for phosphorus removal. Bioretention media, with a higher short-term phosphorus sorption capacity, retained more phosphorus from infiltrating runoff after 3 mg/L phosphorus loading. A surface mulch layer prevented clogging after repetitive total suspended solids input. Evidence suggests that long-term phosphorus reactions will regenerate active short-term phosphorus adsorption sites. A high hydraulic conductivity media overlaying one with low hydraulic conductivity resulted in a higher runoff infiltration rate, from 0.51 to 0.16 cm/min at a fixed 15-cm head, and was more efficient in phosphorus removal (85% mass removal) than a profile with low conductivity media over high (63% mass removal). Media extractions suggest that most of the retained phosphorus in the media layers is available for vegetative uptake and that environmental risk thresholds were not exceeded.

  1. [Effect of phosphorus on the production of microcystin].

    Science.gov (United States)

    Shi, Hong-Xing; Wang, Geng; Wang, Chen-Yu; Li, Yan-Li; Bai, Yun

    2011-10-01

    Effect of phosphorus on the production of microcystin was researched. The effects of soluble reactive phosphorus (SRP) on the growth of cells and on the production of Microcystin were studied. In addition, the efficiency of four different phosphorus compounds was researched. The results showed that microcystin increased with the increase of SRP, and c(TP) = 0.55 mg x L(-1) was the best growth concentration. When c(TP) microcystin production increased with the increase of phosphorus concentration and was the lowest without phosphorus. Moreover, when c(TP) > 0.55 mg x L(-1), the microcystin was restrained by the content of phosphorus. At the same time, the effects of three inorganic substance of different phosphorus forms (K3PO4, K2HPO4, and KH2PO4) were no significant difference, but their effects on the production of microcystis were larger than organic phosphorus of sodium beta-glycerophosphate (GP).

  2. Xingfa Group: To Be World-Famous Phosphorus Chemical Enterprise

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ As the biggest fine phosphorus chemical producer in China, Hubei Xingfa Chemicals Co., Ltd. (Xingfa Group, SH: 600141) is mainly engaged in the production and sales of phosphorus chemicals and fine chemicals.

  3. Phosphorus cycling in agricultural soils. Pt.1: Introduction

    NARCIS (Netherlands)

    Ritsema, C.J.

    1987-01-01

    The excess of phosphorus brought into the soil system is subject to transformation processes and displacement. In general, the mobility of phosphorus in soil solution will remain low due to the very effective retention possibilities of soil

  4. Changes of organic phosphorus in river waters in northern Bangladesh

    Directory of Open Access Journals (Sweden)

    MJ Islam

    2015-12-01

    Full Text Available The variability in phosphorus concentrations and the decomposition rates of organic phosphorus were measured in five selected rivers through four surveys in July and November of 2012, and February and May of 2013. After collection the water samples were incubated for 20 days in a dark incubator and the change of forms of phosphorus such as particulate organic phosphorus (POP, dissolved organic phosphorus (DOP and dissolved inorganic phosphorus (DIP were analyzed. By fitting the changes to two types of models, the decomposition rates of organic phosphorus were determined. The mean total organic phosphorus (TOP decomposition rate coefficients in the studied rivers was 0.039 day-1. The average POP decomposition rate coefficient (POP→DOP→DIP model was 0.038 day-1 while the mean DOP decomposition rate coefficient was 0.251 day-1. The decomposition rate coefficients measured in this study might be applicable for modeling of river water quality.

  5. Flammability of Epoxy Resins Containing Phosphorus

    Science.gov (United States)

    Hergenrother, P. M.; Thompson, C. M.; Smith, J. G.; Connell, J. W.; Hinkley, J. A.

    2005-01-01

    As part of a program to develop fire-resistant exterior composite structures for future subsonic commercial and general aviation aircraft, flame-retardant epoxy resins are under investigation. Epoxies and their curing agents (aromatic diamines) containing phosphorus were synthesized and used to prepare epoxy formulations. Phosphorus was incorporated within the backbone of the epoxy resin and not used as an additive. The resulting cured neat epoxy formulations were characterized by thermogravimetric analysis, propane torch test, elemental analysis, microscale combustion calorimetry, and fire calorimetry. Several formulations showed excellent flame retardation with phosphorous contents as low as 1.5% by weight. The fracture toughness and compressive strength of several cured formulations showed no detrimental effect due to phosphorus content. The chemistry and properties of these new epoxy formulations are discussed.

  6. Adaptive Evolution of Phosphorus Metabolism in Prochlorococcus

    DEFF Research Database (Denmark)

    Casey, John R; Mardinoglu, Adil; Nielsen, Jens

    2016-01-01

    reactions involving 680 metabolites distributed in 6 subcellular locations. iJC568 was used to quantify metabolic fluxes under PLG conditions, and we observed a close correspondence between experimental and computed fluxes. We found that MED4 has minimized its dependence on intracellular phosphate, not only...... and in the field; however, the optimization of phosphorus metabolism and associated gains for its phosphorus-limited-growth (PLG) phenotype have not been studied. Here, we reconstructed a genome-scale metabolic network of the HLI axenic strain MED4 (iJC568), consisting of 568 metabolic genes in relation to 794...... and an extremely high proportion of essential metabolic genes (47%; defined as the percentage of lethal in silico gene knockouts). These strategies are examples of nutrient-controlled adaptive evolution and confer a dramatic growth rate advantage to MED4 in phosphorus-limited regions. ...

  7. Dynamic Coupling of Iron, Manganese, and Phosphorus Behavior in Water and Sediment of Shallow Ice-Covered Eutrophic Lakes.

    Science.gov (United States)

    Schroth, Andrew W; Giles, Courtney D; Isles, Peter D F; Xu, Yaoyang; Perzan, Zachary; Druschel, Gregory K

    2015-08-18

    Decreasing duration and occurrence of northern hemisphere ice cover due to recent climate warming is well-documented; however, biogeochemical dynamics underneath the ice are poorly understood. We couple time-series analyses of water column and sediment water interface (SWI) geochemistry with hydrodynamic data to develop a holistic model of iron (Fe), manganese (Mn), and phosphorus (P) behavior underneath the ice of a shallow eutrophic freshwater bay. During periods of persistent subfreezing temperatures, a highly reactive pool of dissolved and colloidal Fe, Mn, and P develops over time in surface sediments and bottom waters due to reductive dissolution of Fe/Mn(oxy)hydroxides below the SWI. Redox dynamics are driven by benthic O2 consumption, limited air-water exchange of oxygen due to ice cover, and minimal circulation. During thaw events, the concentration, distribution and size partitioning of all species changes, with the highest concentrations of P and "truly dissolved" Fe near the water column surface, and a relatively well-mixed "truly dissolved" Mn and "colloidal" Fe profile due to the influx of geochemically distinct river water and increased circulation. The partitioning and flux of trace metals and phosphorus beneath the ice is dynamic, and heavily influenced by climate-dependent physical processes that vary in both time and space.

  8. Phosphorus isothermal adsorption characteristics of mulch of bioretention

    OpenAIRE

    Mei Ying; Yang Xiao-Hua; Jiang Rong; Di Chong-Li; Zhang Xue-Jun

    2012-01-01

    This study aims to identify mulch of bioretention which has high phosphorus sorption capacity. The phosphorus adsorption characteristics of five types of mulch of bioretention are studied by three isothermal adsorption experiments. Results show that the Langmuir eqution is suitable for describing absorption characteristics of five types of mulch. The positive values of Gibbs free energy for phosphorus indicate that the phosphorus biosorption by five mulches is a non-spontaneous process,...

  9. [Bone and Nutrition. A novel function of phosphorus].

    Science.gov (United States)

    Taketani, Yutaka; Imi, Yukiko; Abuduli, Maerjianghan

    2015-07-01

    Phosphorus is an essential nutrient for bone formation by forming hydroxyapatite with calcium. Simultaneously, phosphorus is also a component of high energy bond of ATP, nucleic acids, and phospholipids. Recent studies have demonstrated that excess or lack of dietary phosphorus intake may cause vascular dysfunction, cardiac hypertrophy, and impaired glucose tolerance. Here, we introduce recent findings about the effects of high or low dietary phosphorus intake on several organs except for bone.

  10. Results of activated sludge plants applying enhanced biological phosphorus removal

    Energy Technology Data Exchange (ETDEWEB)

    Machado, A.; Pinto, M.; Neder, K.; Hoffmann, H.

    1989-02-01

    To stop the eutrophication in lakes and rivers, the input of nutrient and phosphorus compounds must be limited. The biological elimination of phosphorus describes a possibility, to reduce phosphorus in the biological stage of a treatment plant to a considerable extent. In this paper the process-system and the operation-results of a pilot plant and two municipal treatment plants are presented, where biological phosphorus reduction about 80% takes place without any constructional modifications.

  11. Rare Earth Market Review

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Oversupply of rare earths led to the significant price drop of rare earth mineral products and separated products in Chinese domestic market. To stabilize the price, prevent waste of resources, further improve regulation capability on domestic rare earth market and rare earth price and maintain sustaining and healthy development of rare earth industry, partial rare earth producers in Baotou and Jiangxi province projected to cease the production for one month.

  12. IMPROVING PHOSPHORUS NUTRITION OF COTTON

    Directory of Open Access Journals (Sweden)

    Walter B. Gordon

    2014-01-01

    Full Text Available Crop recovery of applied Phosphorus (P fertilizer can be low, especially during season of low soil temperature, which decreases plant root growth and nutrient uptake. The H2PO4- or HPO4-2 anions readily react with soil cations such as Calcium (Ca, Magnesium (Mg, iron (Fe and Aluminum (Al to produce various phosphate compounds of very limited water solubility. Specialty Fertilizer Products (SFP, Leawood, KS, USA has developed and patented a product registered as AVAIL® that is reported to attract and sequester antagonistic cations out of the soil solution leaving more of applied P in available form for plant uptake. To evaluate effectiveness of AVAIL product for cotton production, experiments were conducted in two locations in West Tennessee, Grand Junction (GJ in Hardeman County and Ames Plantation (AP located in Fayette County. Treatments consisted of applying Mono-Ammonium Phosphate (MAP, 11-52-0 alone or coated with AVAIL at rates of 34 or 68 kg ha-1 P2O5. A no P check was also included. An additional treatment consisting of AVAIL treated P in combination with Nutrisphere-N®, a Nitrogen (N stabilizer product offered by SFP, was also included. At GJ site, when averaged over P rates and years, AVAIL treated MAP improved tissue P concentration and increased cotton lint yield by 157 kg ha-1 over untreated MAP. At AP site, when averaged over years and P rates, application of AVAIL treated MAP increased cotton lint yield by 85 kg ha-1 over untreated MAP. In both experiments, 34 kg ha-1 AVAIL treated MAP produced higher tissue P concentrations and greater yields than 68 kg ha-1 without AVAIL. Influencing reactions in the micro-environment around the fertilizer granule has proven to have a significant benefit on the yield and P uptake of cotton. More research is needed to determine P content in the soil and further

  13. 46 CFR 151.50-50 - Elemental phosphorus in water.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Elemental phosphorus in water. 151.50-50 Section 151.50... phosphorus in water. (a) Tanks shall be designed and tested for a head equivalent to the design lading of phosphorus and its water blanket extended to 8 feet above the tank top. In addition, tank design...

  14. Reaching ultra low phosphorus concentrations by filtration techniques

    NARCIS (Netherlands)

    Scherrenberg, S.M.

    2011-01-01

    This research deals with tertiary treatment techniques used for the removal of phosphorus from wastewater treatment plant (WWTP) effluent. The main objective of this research is to obtain ultra low total phosphorus (<0.15 mg total phosphorus/L) concentrations by coagulation, flocculation and filtrat

  15. 76 FR 38592 - Phosphorus Water Quality Standards for Florida Everglades

    Science.gov (United States)

    2011-07-01

    ... AGENCY 40 CFR Part 131 Phosphorus Water Quality Standards for Florida Everglades AGENCY: Environmental... provisions of Florida's Water Quality Standards for Phosphorus in the Everglades Protection Area (Phosphorus... are not applicable water quality standards for purposes of the Clean Water Act. EPA is proposing...

  16. 77 FR 46298 - Phosphorus Water Quality Standards for Florida Everglades

    Science.gov (United States)

    2012-08-03

    ... AGENCY 40 CFR Part 131 RIN 2040-AF38 Phosphorus Water Quality Standards for Florida Everglades AGENCY... provisions of Florida's Water Quality Standards for Phosphorus in the Everglades Protection Area (Phosphorus... are not applicable water quality standards for purposes of the Clean Water Act. EPA is...

  17. Availability of phosphorus contained in poultry litter for lambs.

    Science.gov (United States)

    Tagari, H; Silanikove, N; Hurwitz, S

    1981-03-01

    Percentage net phosphorus availability (NPHA) and set phosphorus utilization (NPHU) of the phosphorus contained in a heat-sterilized poultry litter (PL) as compared to feed grade dicalcium phosphate (DCP) for lambs was assessed by the "slope" method. The method was based on the evaluation of the function of apparent phosphorus absorption (NPHA), or retention (NPHU), on phosphorus intake. Nitrogen retention was also evaluated. Plasma inorganic phosphorus concentration as a function of phosphorus intake was evaluated and compared to NPHA and NPHU. The percentage of NPHA was found to be 63.7 and 39, and that of NPHU was 63 and 38 for the phosphorus supplied by DCP and PL, respectively. Thus, the NPHA or NPHU for the phosphorus contained in PL is 60.9 and 60.3% of that of DCP, respectively. The slope ratio between the two phosphate supplements as observed for plasma inorganic phosphorus concentrations was similar to those found for NPHA and NPHU but the coefficient of variation was 5 times higher. Nitrogen digestibility was not affected by the level of phosphorus in the diets. Correlation between nitrogen retention and NPHA or NPHU was, however, significant (P less than 0.05). The slopes of dependence of N retention upon phosphorus intake were 2.81 and 1.6 (P less than 0.05) for DCP and PL treatments, respectively, and the ratio between the slopes was 0.57, close to the ratio of NPHU in PL to DCP-supplemented diets.

  18. Reaching ultra low phosphorus concentrations by filtration techniques

    NARCIS (Netherlands)

    Scherrenberg, S.M.

    2011-01-01

    This research deals with tertiary treatment techniques used for the removal of phosphorus from wastewater treatment plant (WWTP) effluent. The main objective of this research is to obtain ultra low total phosphorus (<0.15 mg total phosphorus/L) concentrations by coagulation, flocculation and

  19. 40 CFR 721.2752 - Epoxy resin containing phosphorus (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Epoxy resin containing phosphorus... Specific Chemical Substances § 721.2752 Epoxy resin containing phosphorus (generic). (a) Chemical substance... epoxy resin containing phosphorus (PMN P-00-912) is subject to reporting under this section for...

  20. Recovering the primary geochemistry of Jack Hills zircons through quantitative estimates of chemical alteration

    Science.gov (United States)

    Bell, Elizabeth A.; Boehnke, Patrick; Harrison, T. Mark

    2016-10-01

    Despite the robust nature of zircon in most crustal and surface environments, chemical alteration, especially associated with radiation damaged regions, can affect its geochemistry. This consideration is especially important when drawing inferences from the detrital record where the original rock context is missing. Typically, alteration is qualitatively diagnosed through inspection of zircon REE patterns and the style of zoning shown by cathodoluminescence imaging, since fluid-mediated alteration often causes a flat, high LREE pattern. Due to the much lower abundance of LREE in zircon relative both to other crustal materials and to the other REE, disturbance to the LREE pattern is the most likely first sign of disruption to zircon trace element contents. Using a database of 378 (148 new) trace element and 801 (201 new) oxygen isotope measurements on zircons from Jack Hills, Western Australia, we propose a quantitative framework for assessing chemical contamination and exchange with fluids in this population. The Light Rare Earth Element Index is scaled on the relative abundance of light to middle REE, or LREE-I = (Dy/Nd) + (Dy/Sm). LREE-I values vary systematically with other known contaminants (e.g., Fe, P) more faithfully than other suggested proxies for zircon alteration (Sm/La, various absolute concentrations of LREEs) and can be used to distinguish primary compositions when textural evidence for alteration is ambiguous. We find that zircon oxygen isotopes do not vary systematically with placement on or off cracks or with degree of LREE-related chemical alteration, suggesting an essentially primary signature. By omitting zircons affected by LREE-related alteration or contamination by mineral inclusions, we present the best estimate for the primary igneous geochemistry of the Jack Hills zircons. This approach increases the available dataset by allowing for discrimination of on-crack analyses (and analyses with ambiguous or no information on spot placement or

  1. Simultaneous Recovery of Iron and Phosphorus from a High-Phosphorus Oolitic Iron Ore to Prepare Fe-P Alloy for High-Phosphorus Steel Production

    Science.gov (United States)

    Yang, Congcong; Zhu, Deqing; Pan, Jian; Lu, Liming

    2017-09-01

    Unlike previous dephosphorization studies, the present work complies with a concept to recover phosphorus within the utilization of high-phosphorus oolitic iron ores to prepare Fe -P alloy for high-phosphorus steel production. Simultaneous enrichment of iron and phosphorus can be achieved by directly alloying the high-phosphorus oolitic iron ore at high reduction temperatures (≥1623 K). Neither fluxes nor other special additives need to be used. Consequently, the phosphorus element migrates from original apatite to the slag phase with the elevating temperature from 1323 K to 1473 K, and it further moves into metallic iron and forms Fe3P at 1623 K. A metalized iron -phosphorus alloy with assaying of 96.51% iron and 2.03% phosphorus content was obtained at 1623 K for 10 min at corresponding iron and phosphorus recovery rates of 97.50% and 64.51%, respectively. This process exhibits high economic efficiency and is practicable as a stepping-stone for the efficient and direct utilization of high-phosphorus iron ore resources.

  2. The nature of the earth's core

    Science.gov (United States)

    Jeanloz, Raymond

    1990-01-01

    The properties of the earth's core are overviewed with emphasis on seismologically determined regions and pressures and seismologically measured density, elastic wave velocities, and gravitational acceleration. Attention is given to solid-state convection of the inner core, and it is noted that though seismological results do not conclusively prove that the inner core is convective, the occurrence and magnitude of seismic anisotropy are explained by the effects of solid-state convection. Igneous petrology and geochemistry of the inner core, a layer at the base of the mantle and contact metasomatism at the core-mantle boundary, and evolution of the core-mantle system are discussed. It is pointed out that high-pressure melting experiments indicate that the temperature of the core is ranging from 4500 to 6500 K, and a major implication of such high temperature is that the tectonics and convection of the mantle, as well as the resulting geological processes observed at the surface, are powered by heat from the core. As a result of the high temperatures, along with the compositional contrast between silicates and iron alloy, the core-mantle boundary is considered to be most chemically active region of the earth.

  3. Phosphorus status of soils from contrasting forested ecosystems in Southwestern Siberia: combined effects of plant species and climate

    OpenAIRE

    2012-01-01

    The Russian boreal forest, which mainly consists of extensive forests in Siberia, is the largest continuous forest region on Earth and represents 70 % of the world's boreal forest. Siberian forest is a tremendous repository of terrestrial organic carbon (C), which may increase owing to climate change, potential increases in ecosystem productivity and hence C sequestration. Phosphorus (P) availability could limit the C sequestration potential, but tree roots may mine the soil deeper to ...

  4. Linking bacterial diversity and geochemistry of uranium-contaminated groundwater.

    Science.gov (United States)

    Cho, Kelly; Zholi, Alma; Frabutt, Dylan; Flood, Matthew; Floyd, Dalton; Tiquia, Sonia M

    2012-01-01

    To understand the link between bacterial diversity and geochemistry in uranium-contaminated groundwater, microbial communities were assessed based on clone libraries of 16S rDNA genes from the USDOE Oak Ridge Field Research Centre (FRC) site. Four groundwater wells (GW835, GW836, FW113-47 and FW215-49) with a wide range of pH (3 to 7), nitrate (44 to 23,400 mg L(-1)), uranium (0.73 to 60.36 mg L(-1)) and other metal contamination, were investigated. Results indicated that bacterial diversity correlated with the geochemistry of the groundwater. Microbial diversity decreased in relation to the contamination levels of the wells. The highly contaminated well (FW113-47) had lower gene diversity than less contaminated wells (FW215-49, GW835 and GW836). The high concentrations of contaminants present in well FW113-47 stimulated the growth of organisms capable of reducing uranium (Shewanella and Pseudomonas), nitrate (Pseudomonas, Rhodanobacter and Xanthomonas) and iron (Stenotrophomonas), and which were unique to this well. The clone libraries consisted primarily of sequences closely related to the phylum Proteobacteria, with FW-113-47 almost exclusively containing this phylum. Metal-reducing bacteria were present in all four wells, which may suggest that there is potential for successful bioremediation of the groundwater at the Oak Ridge FRC. The microbial community information gained from this study and previous studies at the site can be used to develop predictive multivariate and geographical information system (GIS) based models for microbial populations at the Oak Ridge FRC. This will allow for a better understanding of what organisms are likely to occur where and when, based on geochemistry, and how these organisms relate to bioremediation processes at the site.

  5. Geochemistry and chronology of the Bunburra Rockhole ungrouped achondrite

    Science.gov (United States)

    Spivak-Birndorf, Lev J.; Bouvier, Audrey; Benedix, Gretchen K.; Hammond, Samantha; Brennecka, Gregory A.; Howard, Kieren; Rogers, Nick; Wadhwa, Meenakshi; Bland, Philip A.; Spurný, Pavel; Towner, Martin C.

    2015-05-01

    Bunburra Rockhole is a unique basaltic achondrite that has many mineralogical and petrographic characteristics in common with the noncumulate eucrites, but differs in its oxygen isotope composition. Here, we report a study of the mineralogy, petrology, geochemistry, and chronology of Bunburra Rockhole to better understand the petrogenesis of this meteorite and compare it to the eucrites. The geochemistry of bulk samples and of pyroxene, plagioclase, and Ca-phosphate in Bunburra Rockhole is similar to that of typical noncumulate eucrites. Chronological data for Bunburra Rockhole indicate early formation, followed by slow cooling and perhaps multiple subsequent heating events, which is also similar to some noncumulate eucrites. The 26Al-26Mg extinct radionuclide chronometer was reset in Bunburra Rockhole after the complete decay of 26Al, but a slight excess in the radiogenic 26Mg in a bulk sample allows the determination of a model 26Al-26Mg age that suggests formation of the parent melt for this meteorite from its source magma within the first ~3 Ma of the beginning of the solar system. The 207Pb-206Pb absolute chronometer is also disturbed in Bunburra Rockhole minerals, but a whole-rock isochron provides a re-equilibration age of ~4.1 Ga, most likely caused by impact heating. The mineralogy, geochemistry, and chronology of Bunburra Rockhole demonstrate the similarities of this achondrite to the eucrites, and suggest that it formed from a parent melt with a composition similar to that for noncumulate eucrites and subsequently experienced a thermal history and evolution comparable to that of eucritic basalts. This implies the formation of multiple differentiated parent bodies in the early solar system that had nearly identical bulk elemental compositions and petrogenetic histories, but different oxygen isotope compositions inherited from the solar nebula.

  6. Residue formations of phosphorus hydride polymers and phosphorus oxyacids during phosphine gas fumigations of stored products.

    Science.gov (United States)

    Flora, Jason W; Byers, Loran E; Plunkett, Susan E; Faustini, Daryl L

    2006-01-11

    With the extent of international usage and the critical role phosphine gas (PH3) plays in commercial pest control, identification of the residual components deposited during fumigation is mandatory. It has been postulated that these infrequent residues are primarily composed of phosphoric acid or reduced forms of phosphoric acid [hypophosphorous acid (H3PO2) and phosphorous acid (H3PO3)], due to the oxidative degradation of phosphine. Using environmental scanning electron microscopy, gas phase Fourier transform infrared spectroscopy, and X-ray fluorescence spectroscopy, the structural elucidation and formation mechanism of the yellow amorphous polyhydric phosphorus polymers (P(x)H(y)) that occur in addition to the lower oxyacids of phosphorus in residues deposited during PH3 fumigations of select tobacco commodities are explored. This research determined that nitric oxide gas (or nitrogen dioxide) initiates residue formation of phosphorus hydride polymers and phosphorus oxyacids during PH3 fumigations of stored products.

  7. Infrared Spectroscopy and Stable Isotope Geochemistry of Hydrous Silicate Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Stolper, Edward

    2007-03-05

    The focus of this DOE-funded project has been the study of volatile components in magmas and the atmosphere. Over the twenty-one year period of this project, we have used experimental petrology and stable isotope geochemistry to study the behavior and properties of volatile components dissolved in silicate minerals and melts and glasses. More recently, we have also studied the concentration and isotopic composition of CO2 in the atmosphere, especially in relation to air quality issues in the Los Angeles basin.

  8. Private Collection of Geochemistry and Oceanography Articles Available

    Science.gov (United States)

    Manheim, Frank T.

    2014-05-01

    It's time! I'm disposing of a 37-year career's worth of books and other scientific materials in geochemistry and oceanography. Ordinarily, reprints of articles have little value. However, in the course of my research, I assembled what may be the world's most comprehensive private collection of articles on marine ferromanganese deposits up to the late 1980s. It includes foreign language materials, especially Russian language articles. Soviet researchers played an active role in this field (I cooperated with them and was a guest of the Soviet Academy).

  9. Carbon isotope geochemistry of the Santa Clara River

    OpenAIRE

    2001-01-01

    The Santa Clara River is a prototypical small mountainous river, with a headwater height greater than 1000 m and a basin area smaller than 10,000 m 2. Although individual small mountainous rivers export trivial amounts of sediment and carbon to the ocean, as a group these rivers may export a major fraction (as much as 50%) of the total global river sediment flux [Milliman and Syvitski, 1992], making their geochemistry relevant the study of the ocean's carbon cycle. In addition, many small riv...

  10. Simulation of Water Chemistry using and Geochemistry Code, PHREEQE

    Energy Technology Data Exchange (ETDEWEB)

    Chi, J.H. [Korea Electric Power Research Institute, Taejeon (Korea)

    2001-07-01

    This report introduces principles and procedures of simulation for water chemistry using a geochemistry code, PHREEQE. As and example of the application of this code, we described the simulation procedure for titration of an aquatic sample with strong acid to investigate the state of Carbonates in aquatic solution. Major contents of this report are as follows; Concepts and principles of PHREEQE, Kinds of chemical reactions which may be properly simulated by PHREEQE, The definition and meaning of each input data, An example of simulation using PHREEQE. (author). 2 figs., 1 tab.

  11. Effects of Amazonian Dark Earths on growth and leaf nutrient balance of tropical tree seedlings

    NARCIS (Netherlands)

    Quintero Vallejo, Estela; Pena Claros, M.; Bongers, F.; Toledo, M.; Poorter, L.

    2015-01-01

    Background and aims: Amazonian Dark Earths (ADE) are ancient anthropogenic soils distributed in the Amazon basin. They are characterized by high nutrients such as phosphorus, calcium, potassium and nitrogen. We studied the effect of ADE on growth, morphology and physiology of 17 tree species from a

  12. Improving phosphorus use efficiency in agriculture

    NARCIS (Netherlands)

    Wiel, van de Clemens C.M.; Linden, van der Gerard; Scholten, Olga E.

    2016-01-01

    Phosphorus (P) is often an important limiting factor for crop yields, but rock phosphate as fertilizer is a non-renewable resource and expected to become scarce in the future. High P input levels in agriculture have led to environmental problems. One of the ways to tackle these issues simultaneou

  13. Phosphorus recovery from sewage sludge char ash

    NARCIS (Netherlands)

    Atienza-Martinez, M.; Gea, G.; Arauzo, J.; Kersten, S.R.A.; Kootstra, A.M.J.

    2014-01-01

    Phosphorus was recovered from the ash obtained after combustion at different temperatures (600 °C, 750 °C and 900 °C) and after gasification (at 820 °C using a mixture of air and steam as fluidising agent) of char from sewage sludge fast pyrolysis carried out at 530 °C. Depending on the leaching con

  14. Use of reactive materials to bind phosphorus

    NARCIS (Netherlands)

    Chardon, W.J.; Groenenberg, J.E.; Temminghoff, E.J.M.; Koopmans, G.F.

    2012-01-01

    Phosphorus (P) losses from agricultural soils have caused surface water quality impairment in many regions of the world, including The Netherlands. Due to the large amounts of P accumulated in Dutch soils, the generic fertilizer and manure policy will not be sufficient to reach in time the surface

  15. Phosphorus recovery and reuse from waste streams

    Science.gov (United States)

    Phosphorus (P) is a macronutrient essential for all living organisms. Regrettably, it is a finite resource since phosphate rock (PR) is the main material used for production of P fertilizers. Globally, the demand for quality PR is escalating due to many factors including increasing human population....

  16. Phosphate recycling in the phosphorus industry

    NARCIS (Netherlands)

    Schipper, W.J.; Klapwijk, A.; Potjer, A.; Rulkens, W.H.; Temmink, B.G.; Kiestra, F.D.G.; Lijmbach, A.C.M.

    2001-01-01

    The feasibility of phosphate recycling in the white phosphorus production process is discussed. Several types of materials may be recycled, provided they are dry inorganic materials, low in iron, copper and zinc. Sewage sludge ash may be used if no iron is used for phosphate precipitation in the tre

  17. Phosphorus recycling from the waste sector

    NARCIS (Netherlands)

    Ruijter, de F.J.; Dijk, Van W.; Curth-van Middelkoop, J.C.; Reuler, van H.

    2015-01-01

    An efficient use of phosphorus (P) is necessary as phosphate rock is a finite resource and P is essential for crop production. From the waste sector in the Netherlands, 23 Mkg P is sequestered in landfill, incineration ashes and cement. Flows containing P are discussed, together with options to reco

  18. Kinetic Equations for Describing Phosphorus Transport

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@Studies on kinetics of adsorption and release of phosphorus by soil,a new field in soil chemistry,began only over ten years ago (He et al.,1989; Wang and Zhu,1988;Zhang and Zhang,1991; Lin,1989; Lin and Xue,1989; Jiang,1993; Xue et al.,1995;LU et al.,1997).

  19. Regulating phosphorus from the agricultural sector

    DEFF Research Database (Denmark)

    Hansen, Line Block; Hansen, Lars Gårn; Rubæk, Gitte Holton

    2010-01-01

      Loss of phosphorus (P) from agricultural areas is one of the main contributors to eutrophication of water systems in many European countries. Regulatory systems such as ambient taxes or discharge taxes which are suitable for regulation of N are insufficient for regulating P because these systems...

  20. Nanotubes based on monolayer blue phosphorus

    KAUST Repository

    Montes Muñoz, Enrique

    2016-07-08

    We demonstrate structural stability of monolayer zigzag and armchair blue phosphorus nanotubes by means of molecular dynamics simulations. The vibrational spectrum and electronic band structure are determined and analyzed as functions of the tube diameter and axial strain. The nanotubes are found to be semiconductors with a sensitive indirect band gap that allows flexible tuning.

  1. Phosphate recycling in the phosphorus industry

    NARCIS (Netherlands)

    Schipper, W.J.; Klapwijk, A.; Potjer, B.; Rulkens, W.H.; Temmink, B.G.; Kiestra, F.D.G.; Lijmbach, A.C.M.

    2004-01-01

    The article describes the potential and limitations for recovery of phosphate from secondary materials in the production process for white phosphorus. This thermal process involves the feeding of phosphate rock, cokes and pebbles to a furnace. The reducing conditions in the furnace promote the forma

  2. Endangered plants persist under phosphorus limitation.

    Science.gov (United States)

    Wassen, Martin J; Venterink, Harry Olde; Lapshina, Elena D; Tanneberger, Franziska

    2005-09-22

    Nitrogen enrichment is widely thought to be responsible for the loss of plant species from temperate terrestrial ecosystems. This view is based on field surveys and controlled experiments showing that species richness correlates negatively with high productivity and nitrogen enrichment. However, as the type of nutrient limitation has never been examined on a large geographical scale the causality of these relationships is uncertain. We investigated species richness in herbaceous terrestrial ecosystems, sampled along a transect through temperate Eurasia that represented a gradient of declining levels of atmospheric nitrogen deposition--from approximately 50 kg ha(-1) yr(-1) in western Europe to natural background values of less than 5 kg ha(-1) yr(-1) in Siberia. Here we show that many more endangered plant species persist under phosphorus-limited than under nitrogen-limited conditions, and we conclude that enhanced phosphorus is more likely to be the cause of species loss than nitrogen enrichment. Our results highlight the need for a better understanding of the mechanisms of phosphorus enrichment, and for a stronger focus on conservation management to reduce phosphorus availability.

  3. Stewardship to tackle global phosphorus inefficiency

    NARCIS (Netherlands)

    Withers, P.J.A.; Dijk, van K.C.; Neset, T.S.S.; Nesme, Thomas; Oenema, Oene; Rubæk, G.H.; Schoumans, O.F.; Smit, Bert; Pellerin, Sylvain

    2015-01-01

    The inefficient use of phosphorus (P) in the food chain is a threat to the global aquatic environment and the health and well-being of citizens, and it is depleting an essential finite natural resource critical for future food security and ecosystem function. We outline a strategic framework of 5

  4. Lake Erie phosphorus loading and Cladophora updates

    Science.gov (United States)

    The presentation will focus on updates or progress being made on each Phosphorus Loadings and Cladophora for Lake Erie. The format will give a brief summary of data, findings, and results that were used by the Great Lakes Water Quality Agreement (GLWQA) Annex 4 Nutrients Modeli...

  5. Use of reactive materials to bind phosphorus

    NARCIS (Netherlands)

    Chardon, W.J.; Groenenberg, J.E.; Temminghoff, E.J.M.; Koopmans, G.F.

    2012-01-01

    Phosphorus (P) losses from agricultural soils have caused surface water quality impairment in many regions of the world, including The Netherlands. Due to the large amounts of P accumulated in Dutch soils, the generic fertilizer and manure policy will not be sufficient to reach in time the surface w

  6. A Study on Phosphorus Use Efficiency of Wheat

    Institute of Scientific and Technical Information of China (English)

    Yuanyuan YUAN; Kai GUO; Bei DONG; Rongting ZHANG; Liwen SUN

    2016-01-01

    Wheat is one of the most important grain crops in China with great demand. It plays an important role to use phosphorus fertilizer for improving wheat yield. Therefore,application and foundation studies on wheat phosphorus use efficiency are so vital nowadays. Here,we have a simple review on definition of phosphorus use efficiency,response to phosphate starvation in plant,relevant genes cloning,impact factors,screening high phosphorus efficiency genotype and QTL analysis of phosphorus utilization efficiency in wheat.

  7. Temperature-dependant study of phosphorus ion implantation in germanium

    Science.gov (United States)

    Razali, M. A.; Smith, A. J.; Jeynes, C.; Gwilliam, R. M.

    2012-11-01

    We present experimental results on shallow junction formation in germanium by phosphorus ion implantation and standard rapid thermal processing. An attempt is made to improve phosphorus activation by implanting phosphorus at high and low temperature. The focus is on studying the germanium damage and phosphorus activation as a function of implant temperature. Rutherford backscattering spectrometry with channelling and Hall Effect measurements are employed for characterisation of germanium damage and phosphorus activation, respectively. High and low temperature implants were found to be better compared to room temperature implant.

  8. Diversity enhances agricultural productivity via rhizosphere phosphorus facilitation on phosphorus-deficient soils.

    Science.gov (United States)

    Li, Long; Li, Shu-Min; Sun, Jian-Hao; Zhou, Li-Li; Bao, Xing-Guo; Zhang, Hong-Gang; Zhang, Fu-Suo

    2007-07-01

    Intercropping, which grows at least two crop species on the same pieces of land at the same time, can increase grain yields greatly. Legume-grass intercrops are known to overyield because of legume nitrogen fixation. However, many agricultural soils are deficient in phosphorus. Here we show that a new mechanism of overyielding, in which phosphorus mobilized by one crop species increases the growth of a second crop species grown in alternate rows, led to large yield increases on phosphorus-deficient soils. In 4 years of field experiments, maize (Zea mays L.) overyielded by 43% and faba bean (Vicia faba L.) overyielded by 26% when intercropped on a low-phosphorus but high-nitrogen soil. We found that overyielding of maize was attributable to below-ground interactions between faba bean and maize in another field experiment. Intercropping with faba bean improved maize grain yield significantly and above-ground biomass marginally significantly, compared with maize grown with wheat, at lower rates of P fertilizer application (112.5 kg of P(2)O(5) per hectare). By using permeable and impermeable root barriers, we found that maize overyielding resulted from its uptake of phosphorus mobilized by the acidification of the rhizosphere via faba bean root release of organic acids and protons. Faba bean overyielded because its growth season and rooting depth differed from maize. The large increase in yields from intercropping on low-phosphorus soils is likely to be especially important on heavily weathered soils.

  9. EarthRef.org: Exploring aspects of a Cyber Infrastructure in Earth Science and Education

    Science.gov (United States)

    Staudigel, H.; Koppers, A.; Tauxe, L.; Constable, C.; Helly, J.

    2004-12-01

    EarthRef.org is the common host and (co-) developer of a range of earth science databases and IT resources providing a test bed for a Cyberinfrastructure in Earth Science and Education (CIESE). EarthRef.org data base efforts include in particular the Geochemical Earth Reference Model (GERM), the Magnetics Information Consortium (MagIC), the Educational Resources for Earth Science Education (ERESE) project, the Seamount Catalog, the Mid-Ocean Ridge Catalog, the Radio-Isotope Geochronology (RiG) initiative for CHRONOS, and the Microbial Observatory for Fe oxidizing microbes on Loihi Seamount (FeMO; the most recent development). These diverse databases are developed under a single database umbrella and webserver at the San Diego Supercomputing Center. All the data bases have similar structures, with consistent metadata concepts, a common database layout, and automated upload wizards. Shared resources include supporting databases like an address book, a reference/publication catalog, and a common digital archive making database development and maintenance cost-effective, while guaranteeing interoperability. The EarthRef.org CIESE provides a common umbrella for synthesis information as well as sample-based data, and it bridges the gap between science and science education in middle and high schools, validating the potential for a system wide data infrastructure in a CIESE. EarthRef.org experiences have shown that effective communication with the respective communities is a key part of a successful CIESE facilitating both utility and community buy-in. GERM has been particularly successful at developing a metadata scheme for geochemistry and in the development of a new electronic journal (G-cubed) that has made much progress in data publication and linkages between journals and community data bases. GERM also has worked, through editors and publishers, towards interfacing databases with the publication process, to accomplish a more scholarly and database friendly data

  10. Earth from Above

    Science.gov (United States)

    Stahley, Tom

    2006-01-01

    Google Earth is a free online software that provides a virtual view of Earth. Using Google Earth, students can view Earth by hovering over features and locations they preselect or by serendipitously exploring locations that catch their fascination. Going beyond hovering, they can swoop forward and even tilt images to make more detailed…

  11. Phosphorus reduction by sifting fish waste meal

    Directory of Open Access Journals (Sweden)

    Ronaldo Lima de Lima

    2014-10-01

    Full Text Available Fish meal is widely included in animal feed because it contains ideal essential amino acids profile, it is rich in energy, essential fatty acids, vitamins and minerals and with >80% apparent protein digestibility in peneid shrimp. In human nutrition, studies are investigating the inclusion of fish meal in snacks, cakes, breads and cookies, as an enrichment in calcium, phosphorus, iron, protein and, especially, omega-3 fatty acids. Omega-3 fatty acids reduces heart diseases and have antithrombotic and anti-inflammatory properties (eicosapentaenoic acid, and are essential to the formation of brain tissue and retina in infants and are important during pregnancy and lactation (docosahexaenoic acid. Fish meal produced from fish waste is rich in minerals (phosphorus, which may cause eutrophication and impair water quality in aquaculture. The aim of this study was to reduce phosphorus content from commercial fish meal produced from waste by sifting (0.60 - 1.00 - 1.18 - 1.40 - 2.36 and 3.35mm mesh sizes. Fish meal samples were collected monthly for 24 months. Proximate composition of subsamples per mesh size was compared to the unsieved sample. Results indicate that sifting through a 0.60mm sieve total phosphorus and ash contents were reduced up to 32% and 36%, respectively, further to increase protein content up to 20%. Average composition of the subsamples was 47.04% ash, 5.56% of total phosphorus and 39.45% protein, suggesting that the residue of the fractionation may be marketed as a mineral and protein supplement.

  12. Rare Earth Resolution

    Institute of Scientific and Technical Information of China (English)

    Mei Xinyu

    2012-01-01

    BEFORE the early 1970s, China had no rare earth exports, and the world rare earth market was dominated by the United States, Europe and Japan. In the 1970s, China began to enter the world rare earth market and its share has picked up sharply in the following decades. Today, having the monopoly over global rare earth production, China must improve the benefits from rare earth production, not only from producing individual rare earth products, but also from mastering the intensive processing of rare earth products.

  13. Do soils loose phosphorus with dissolved organic matter?

    Science.gov (United States)

    Kaiser, K.; Brödlin, D.; Hagedorn, F.

    2014-12-01

    During ecosystem development and soil formation, primary mineral sources of phosphorus are becoming increasingly depleted. Inorganic phosphorus forms tend to be bound strongly to or within secondary minerals, thus, are hardly available to plants and are not leached from soil. What about organic forms of phosphorus? Since rarely studied, little is known on the composition, mobility, and bioavailability of dissolved organic phosphorus. There is some evidence that plant-derived compounds, such as phytate, bind strongly to minerals as well, while microbial compounds, such as nucleotides and nucleic acids, may represent more mobile fractions of soil phosphorus. In some weakly developed, shallow soils, leaching losses of phosphorus seem to be governed by mobile organic forms. Consequently, much of the phosphorus losses observed during initial stages of ecosystem development may be due to the leaching of dissolved organic matter. However, the potentially mobile microbial compounds are enzymatically hydrolysable. Forest ecosystems on developed soils already depleted in easily available inorganic phosphorus are characterized by rapid recycling of organic phosphors. That can reduce the production of soluble forms of organic phosphorus as well as increase the enzymatic hydrolysis and subsequent plant uptake of phosphorus bound within dissolved organic matter. This work aims at giving an outlook to the potential role of dissolved organic matter in the cycling of phosphorus within developing forest ecosystems, based on literature evidence and first results of ongoing research.

  14. Research progress in studies on the coalbed gas geochemistry

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The current situation of geochemical studies on coalbed gas is reviewed in this paper. Generally, coalbed gas is compositionally dominated by methane with δ13C1 values ranging approximately from - 80‰ to - 10‰. However, few isotopic studies have been carried out on other components of coalbed gas except for hydrogen and carbon dioxide, whose δDCH4 values available for utilization vary from - 333‰ to - 117‰, and δ13CCO2 values from -29.4‰ to + 18.6‰. Two major types of coalbed gas, thermogenic gas and secondary biogenic gas, have been identified, and there are also some other classification criteria. Compared with conventional natural gases,coalbed gas has a wide distribution range of δ13C1 andδ13CCO2 values, especially possessing some extremely heavy values. Current problems that remain unsolved in the coalbed gas geochemistry include the variation mechanism, controlling factors and application of carbon and hydrogen isotopes of methane, the relation between the values of δ13C1 and Ro, the systematic classification scheme and criterion of genetic types, and the application of the coalbed gas geochemistry in evaluating target districts of the coalbed gas exploration.

  15. Proceedings of the Rome seminar on environmental geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Marini, L.; Ottonello, G. [eds.

    1998-12-31

    The paper collected in this book represent most part of the lectures given by invited speakers at the Seminar on Environmental Geochemistry, held in Rome (May 22-26, 1996) under the sponsorship of the `Dipartimento della Protezione Civile` (Ministry of the Interiors), the `Consiglio Nazionale delle Ricerche` (Strategic Projects `Geologia delle grandi aree urbane` e `Carta Geochimica d`Italia`); the University of Genoa and the `Gruppo informale di geochimica`. In deciding to assemble the Proceedings, there was the difficulty of molding the various expertise necessary to deal with the geochemical aspects of environmental problems and of presenting them in a logical sequence. In fact, Geochemistry is a vast subject, strictly connected with Physical Chemistry and Mathematics in its theoretical aspects, but also with Hydrology, Urban Geology, Chemical Engineering, and even Administration in its applicative aspects. It was then decided to privilege at first the theoretical aspects of water-rock interactions processes relevant to environmental control. Indeed, most part of the book is covered by three articles dealing with the numerical aspects of reactive flow and transport in natural systems, the role of metal-organic complexing and of surface-controlled reaction kinetics.

  16. Effect of Carbon on Grain Boundary Segregation of Phosphorus and Phosphorus-Induced Intergranular Fracture in High Purity Iron with Phosphorus

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The segregation of carbon at grain boundaries and its effect on phosphorus segregation and phosphorus-induced intergranular fracture in the alloy of high purity iron with phosphorus were investigated by scanning Auger electron spectroscopy, impact test and SEM observation of fractured surface. The experimental results showed that the carbon segregation at grain boundaries decreases the phosphorus segregation, and a change of fracture mode from intergranular fracture to transgranular one, hence a decrease of ductile-brittle transition temperature is observed. The mechanism of these effects was discussed.

  17. Geochemistry and U-Pb geochronology of detrital zircons in the Brujas beach sands, Campeche, Southwestern Gulf of Mexico, Mexico

    Science.gov (United States)

    Tapia-Fernandez, Hector J.; Armstrong-Altrin, John S.; Selvaraj, Kandasamy

    2017-07-01

    This study investigated the bulk sediment geochemistry, U-Pb ages and rare earth element (REE) geochemistry of one hundred detrital zircons recovered from the Brujas beach sands in southwestern Gulf of Mexico to understand the provenance and age spectra. The bulk sediments are high in Zr and Hf contents (∼1400-3773 ppm and ∼33-90 ppm, respectively) suggested the abundance of resistant mineral zircon. The chondrite normalized REE patterns of the bulk sediments are less fractionated with enriched low REE (LREE; LaCN/SmCN = ∼491-693), depleted heavy REE (HREE; GdCN/YbCN = ∼44-69) and a negative Eu anomaly (Eu/Eu∗ = ∼0.44-0.67) suggested that the source rock is felsic type. The results of this study revealed highly varied contents of Th (∼4.2-321 ppm), U (∼20.7-1680 ppm), and Hf (∼6970-14,200 ppm) in detrital zircons compared to bulk sands. The total REE content (∼75 and 1600 ppm) and its chondrite-normalized pattern with positive Ce and negative Eu anomalies as well as low Th/U ratio of zircon grains indicated that they were dominantly of magmatic origin. U-Pb data of zircons indicated two age populations, with predominance of Permian-Triassic (∼216-286 Ma) and Neoproterozoic (∼551-996 Ma). The Permian-Triassic zircons were contributed by the granitoids and recycled metasedimentary rocks of the Chiapas Massif Complex. The major contribution of Neoproterozoic zircons was from the Chaucus, Oaxacan, and Chiapas Massif Complexes in Grenville Province, southern Mexico. U-Pb ages of zircons from the Brujas beach are consistent to the reported zircon ages from the drainage basins of Usumacinta, Coatzacoalcos, and Grijalva Rivers in southern Mexico, suggesting that the sediments delivered by the rivers to the beach area are vital in defining the provenance of placers.

  18. Geochemistry of Archean metasedimentary rocks of the Aravalli craton, NW India: Implications for provenance, paleoweathering and supercontinent reconstruction

    Science.gov (United States)

    Ahmad, Iftikhar; Mondal, M. E. A.; Satyanarayanan, M.

    2016-08-01

    Basement complex of the Aravalli craton (NW India) known as the Banded Gneissic Complex (BGC) is classified into two domains viz. Archean BGC-I and Proterozoic BGC-II. We present first comprehensive geochemical study of the Archean metasedimentary rocks occurring within the BGC-I. These rocks occur associated with intrusive amphibolites in a linear belt within the basement gneisses. The association is only concentrated on the western margin of the BGC-I. The samples are highly mature (MSm) to very immature (MSi), along with highly variable geochemistry. Their major (SiO2/Al2O3, Na2O/K2O and Al2O3/TiO2) and trace (Th/Sc, Cr/Th, Th/Co, La/Sc, Zr/Sc) element ratios, and rare earth element (REE) patterns are consistent with derivation of detritus from the basement gneisses and its mafic enclaves, with major contribution from the former. Variable mixing between the two end members and closed system recycling (cannibalism) resulted in the compositional heterogeneity. Chemical index of alteration (CIA) of the samples indicate low to moderate weathering of the source terrain in a sub-tropical environment. In A-CN-K ternary diagram, some samples deceptively appear to have undergone post-depositional K-metasomatism. Nevertheless, their petrography and geochemistry (low K2O and Rb) preclude the post-depositional alteration. We propose non-preferential leaching of elements during cannibalism as the cause of the deceptive K-metasomatism as well as enigmatic low CIA values of some highly mature samples. The Archean metasedimentary rocks were deposited on stable basement gneisses, making the BGC-I a plausible participant in the Archean Ur supercontinent.

  19. Elemental and Sm-Nd isotopic geochemistry on detrital sedimentary rocks in the Ganzi-Songpan block and Longmen Mountains

    Institute of Scientific and Technical Information of China (English)

    CHEN Yuelong; LIU Fei; ZHANG Hongfei; NIE Lanshi; JIANG Liting

    2007-01-01

    Systematic results of major and trace element geochemistry and Sm-Nd isotopic geochemistry on detrital sedimentary rocks of Precambrian to Triassic in the Ganzi-Songpan block and Longmen Mountains are presented. The rocks are classified into greywaekes or feldspar sandstones,grains of which are the mixtures of mafic rocks, felsic rocks,and quartz + calcite. Total rare earth elements (REE) contents of the rocks increase gradually and negative Eu anomalies become more obvious from Precambrian to Triassic, which may indicate intensifying crustal anatexis. Tectonic setting was stable during the Late Paleozoic, the refore there are obvious negative Ce anomalies. Nd model ages are between 1.6 Ga and 2.4 Ga, which are very similar to those of the Yangtze croton, South Qinling and North Qinling belts and quite different from those of the North China craton. There-fore, provenance of the sedimentary rocks in the Ganzi-Songpan block and Longmen Mountains was the Yangtze craton and/or the Qinling orogen, which evolved on the basis of the Yangtze craton. The correlation between provenances and tectonostratigraphic strata of the western Yangtze craton shows that the source materials should be primarily from Neoproterozoic. Secondary sources were Archean and Paleoproterozoic strata. Triassic clastic sedimentary rocks contain Late Paleozoic mantle-derived materials, represented by the Emeishan Permian flood basalts. Spatial distribution of initial Nd isotopic compositions indicates that denudating areas were in the east and the north and depositing areas of deep water were in the west and the south for the Ganzi-Songpan basin during Triassic.

  20. Petrology and geochemistry of Late Proterozoic hornblende gabbros from southeast of Fariman, Khorasan Razavi province, Iran

    Directory of Open Access Journals (Sweden)

    Seyed Masoud Homam

    2015-04-01

    Full Text Available Introduction Hornblende-bearing gabbroic rocks are quite common in subduction-related magmatic suites and considered to represent magmatic differentiation process in arc magmas (Heliker, 1995; Hickey-Vargas et al., 1995; Mandal and Ray, 2012. The presence of hornblende as an important mineral phase in gabbroic rocks of subduction zone has been considered either as an early crystallizing mineral from water-bearing mafic magmas (Beard and Borgia 1989; Mandal and Ray, 2012 or as a product of reaction of early crystallized minerals (olivine, pyroxene and plagioclase and water-rich evolved melt/aqueous fluid (Costa et al., 2002; Mandal and Ray, 2012. The careful study of petrology and geochemistry of hornblende-bearing gabbroic rocks from Chahak area, of Neoproterozoic age, can provide important information about their petrogenesis. Because of the special characteristics of Chahak hornblende gabbros according to their age and their situation in the main structural units of Iran, their study can present critical keys for the knowledge of geological history of Iran specially central Iran zone. Material and Methods This study carried out in two parts including field and laboratory works. Sampling and structural studies were carried out during field work. Geological map for the study area was also prepared. 65 thin and polished thin sections for petrographical purpose were studied. Major oxides, rare earth elements and trace elements were analyzed for 4 samples (92P-1, 92P-3, B1and B6 from hornblende gabbros on the basis of 4AB1 method using ICP-MS of ACME Laboratory from Canada. In addition, major oxides of three hornblende gabbro samples (89P-62, 89P-59 and 89P-46 were used from Partovifar (Partovifar, 2012. Results and discussion Fariman metamorphic terrains, of Proterozoic age, consist of metamorphosed sedimentary and igneous (plutonic and volcanic rocks. Hornblende gabbros of the study area include plagioclase, hornblende, biotite pyroxene and

  1. Effect of phosphorus stress on Microcystis aeruginosa growth and phosphorus uptake

    Science.gov (United States)

    Ghaffar, Sajeela; Stevenson, R. Jan; Khan, Zahiruddin

    2017-01-01

    This study was designed to advance understanding of phosphorus regulation of Microcystis aeruginosa growth, phosphorus uptake and storage in changing phosphorus (P) conditions as would occur in lakes. We hypothesized that Microcystis growth and nutrient uptake would fit classic models by Monod, Droop, and Michaelis-Menten in these changing conditions. Microcystis grown in luxury nutrient concentrations was transferred to treatments with phosphorus concentrations ranging from 0–256 μg P∙L-1 and luxury nitrogen. Dissolved phosphorus concentration, cell phosphorus quota, P uptake rate and cell densities were measured at day 3 and 6. Results showed little relationship to predicted models. Microcystis growth was asymptotically related to P treatment from day 0–3, fitting Monod model well, but negatively related to P treatment and cell quota from day 3–6. From day 0–3, cell quota was negatively related to P treatments at <2 μg∙L-1, but increased slightly at higher P. Cell quota decreased greatly in low P treatments from day 3–6, which may have enabled high growths in low P treatments. P uptake was positively and linearly related to P treatment during both periods. Negative uptake rates and increases in measured culture phosphorus concentrations to 5 μg∙L-1 in the lowest P treatments indicated P leaked from cells into culture medium. This leakage during early stages of the experiment may have been sufficient to stimulate metabolism and use of intracellular P stores in low P treatments for rapid growth. Our study shows P regulation of Microcystis growth can be complex as a result of changing P concentrations, and this complexity may be important for modeling Microcystis for nutrient and ecosystem management. PMID:28328927

  2. MESSENGER, MErcury: Surface, Space ENvironment, GEochemistry, and Ranging; A Mission to Orbit and Explore the Planet Mercury

    Science.gov (United States)

    1999-01-01

    MESSENGER is a scientific mission to Mercury. Understanding this extraordinary planet and the forces that have shaped it is fundamental to understanding the processes that have governed the formation, evolution, and dynamics of the terrestrial planets. MESSENGER is a MErcury Surface, Space ENvironment, GEochemistry and Ranging mission to orbit Mercury for one Earth year after completing two flybys of that planet following two flybys of Venus. The necessary flybys return significant new data early in the mission, while the orbital phase, guided by the flyby data, enables a focused scientific investigation of this least-studied terrestrial planet. Answers to key questions about Mercury's high density, crustal composition and structure, volcanic history, core structure, magnetic field generation, polar deposits, exosphere, overall volatile inventory, and magnetosphere are provided by an optimized set of miniaturized space instruments. Our goal is to gain new insight into the formation and evolution of the solar system, including Earth. By traveling to the inner edge of the solar system and exploring a poorly known world, MESSENGER fulfills this quest.

  3. Earth Sciences Division Research Summaries 2006-2007

    Energy Technology Data Exchange (ETDEWEB)

    DePaolo, Donald; DePaolo, Donald

    2008-07-21

    Research in earth and atmospheric sciences has become increasingly important in light of the energy, climate change, and other environmental issues facing the United States and the world. The development of new energy resources other than fossil hydrocarbons, the safe disposal of nuclear waste and greenhouse gases, and a detailed understanding of the climatic consequences of our energy choices are all critical to meeting energy needs while ensuring environmental safety. The cleanup of underground contamination and the preservation and management of water supplies continue to provide challenges, as they will for generations into the future. To address the critical energy and environmental issues requires continuing advances in our knowledge of Earth systems and our ability to translate that knowledge into new technologies. The fundamental Earth science research common to energy and environmental issues largely involves the physics, chemistry, and biology of fluids in and on the Earth. To manage Earth fluids requires the ability to understand their properties and behavior at the most fundamental molecular level, as well as prediction, characterization, imaging, and manipulation of those fluids and their behavior in real Earth reservoirs. The broad range of disciplinary expertise, the huge range of spatial and time scales, and the need to integrate theoretical, computational, laboratory and field research, represent both the challenge and the excitement of Earth science research. The Earth Sciences Division (ESD) of the Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley Lab) is committed to addressing the key scientific and technical challenges that are needed to secure our energy future in an environmentally responsibly way. Our staff of over 200 scientists, UC Berkeley faculty, support staff and guests perform world-acclaimed fundamental research in hydrogeology and reservoir engineering, geophysics and geomechanics, geochemistry, microbial ecology

  4. Earth Sciences Division Research Summaries 2006-2007

    Energy Technology Data Exchange (ETDEWEB)

    DePaolo, Donald; DePaolo, Donald

    2008-07-21

    Research in earth and atmospheric sciences has become increasingly important in light of the energy, climate change, and other environmental issues facing the United States and the world. The development of new energy resources other than fossil hydrocarbons, the safe disposal of nuclear waste and greenhouse gases, and a detailed understanding of the climatic consequences of our energy choices are all critical to meeting energy needs while ensuring environmental safety. The cleanup of underground contamination and the preservation and management of water supplies continue to provide challenges, as they will for generations into the future. To address the critical energy and environmental issues requires continuing advances in our knowledge of Earth systems and our ability to translate that knowledge into new technologies. The fundamental Earth science research common to energy and environmental issues largely involves the physics, chemistry, and biology of fluids in and on the Earth. To manage Earth fluids requires the ability to understand their properties and behavior at the most fundamental molecular level, as well as prediction, characterization, imaging, and manipulation of those fluids and their behavior in real Earth reservoirs. The broad range of disciplinary expertise, the huge range of spatial and time scales, and the need to integrate theoretical, computational, laboratory and field research, represent both the challenge and the excitement of Earth science research. The Earth Sciences Division (ESD) of the Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley Lab) is committed to addressing the key scientific and technical challenges that are needed to secure our energy future in an environmentally responsibly way. Our staff of over 200 scientists, UC Berkeley faculty, support staff and guests perform world-acclaimed fundamental research in hydrogeology and reservoir engineering, geophysics and geomechanics, geochemistry, microbial ecology

  5. Phosphorus release from anaerobic peat soil during convective discharge – effect of soil Fe:P molar ratio and preferential flow

    DEFF Research Database (Denmark)

    Forsmann, Ditte M.; Kjærgaard, Charlotte

    2014-01-01

    was controlled by reductive Fe(III) dissolution, and was well predicted from the soil FeBD:PBD molar ratio. Continuous convective column discharge with oxygen-free deionised water at 1 mm h− 1 for 10 effluent pore volumes resulted in highly variable in situ redox potential (Eh from − 200 to 300 mV), effluent Fe...... influence of soil geochemistry and local scale active flow volume. Combining batch incubation experiments and continuous column discharge experiments, we investigated iron (Fe) reduction and P release from 10 anoxic Fe-dominated (oxalate extractable Fe (Feox) from ~ 5500 to 50,000 mg kg− 1) lowland peat......(II) concentrations (23 to 2000 μM) and effluent dissolved reactive phosphorus (DRP) concentrations (discharge (3...

  6. Rhizosphere effect of different aquatic plants on phosphorus depletion

    Institute of Scientific and Technical Information of China (English)

    Zhenyu WANG; Shengfang WEN; Baoshan XING; Dongmei GAO; Fengmin LI

    2008-01-01

    A series of pot experiments with Alternanthera philoxeroides, Typha latifolia, Sagittaria sagittifolia and Phragmites communis were conducted to assess the phos-phorus depletion effect in the rhizosphere. The ratio of root to shoot, root morphology, phosphorus uptake efficiency and phosphorus utilization efficiency were analyzed. An obvious variation in phosphorus concentrations between the rhizosphere soil and non-rhizosphere soil was observed. The water-soluble P contents in the rhizosphere soil of A. philoxeroides, T. latifolia, S. sagittifolia and P. communis were reduced by 81%, 42%, 18% and 16%, respectively, compared with that in the non-rhizosphere soil. A. philox-eroides had the highest phosphorus uptake efficiency (1.32 mg/m), while T. latifolia achieved the effective phos-phorus depletion by the strong rooting system and the high phosphorus uptake efficiency (0.52 mg/m). T. latifolia not only used phosphorus to produce biomass economically, but also adjusted carbon allocation to the roots to explore the soil for more available phosphorus. A. philoxeroides and T. latifolia were more effective in depleting phosphorus in the rhizosphere than S. sagittifolia and P. communis.

  7. Performance of fertigation technique for phosphorus application in cotton

    Directory of Open Access Journals (Sweden)

    M. Aslam

    2009-05-01

    Full Text Available Low native soil phosphorus availability coupled with poor utilization of added phosphorus is one of the major constraints limiting the productivity of the crops. With a view of addressing this issue, field studies were conducted to compare the relative efficacy of broadcast and fertigation techniques for phosphorus application during 2005-2006 using cotton as a test crop. Two methods of phosphorus application i.e. broadcast and fertigation were evaluated using five levels of P2O5 (0, 30, 45, 60 and 75 kg P2O5 ha -1. Fertigation showed an edge over broadcast method at all levels of phosphorus application. The highest seed cotton yield was recorded with 75 kg P2O5 ha-1. Fertilizer phosphorus applied at the rate of 60 kg ha-1 through fertigation produced 3.4 tons ha-1 of seed cotton yield, which was statistically identical to 3.3 tons recorded with 75 kg ha-1 of broadcast phosphorus. Agronomic performance of phosphorus was influenced considerably by either method of fertilizer application. The seed cotton yield per kg of fertigation phosphorus was 48% higher than the corresponding broadcast application. The results of these studies showed that fertigation was the most efficient method of phosphorus application compared with the conventional broadcast application of fertilizers.

  8. [Radioactivity of phosphorus implanted TiNi alloy].

    Science.gov (United States)

    Zhao, Xingke; Cai, Wei; Zhao, Liancheng

    2003-09-01

    Exposed to neutron flow, the phosphorus implanted TiNi alloy gets radioactive. This radioactive material is used in vascular stent for prevention and cure of restenosis. Phosphorus implantation is carried out in a plasma immerged ion implantation system, and the dose of phosphorus implantation is in the range of 2-10 x 10(17) cm-2. After ion implantation, the alloy is exposed to the slow neutron flow in a nuclear reactor, the dose of the slow neutron is 1.39-5.88 x 10(19) n/cm2. The radioactivity of the TiNi alloy was measured by liquid scintillation spectrometry and radio-chromic-film dosimetry. The result shows that whether the phosphorus is implanted or not, the TiNi alloy comes to be radioactive after exposure to neutron flow. Just after neutron irradiation, the radiation dose of phosphorus implanted TiNi alloy is about one hundred times higher than that of un-phosphorus implanted TiNi alloy. The radiation difference between phosphorus and un-phosphorus implanted alloy decreases as time elapses. Within three months after neutron irradiation, the average half-decay period of phosphorus implanted TiNi alloy is about 62 days. The radiation ray penetration of phosphorus implanted TiNi alloy is deeper than that of pure 32P; this is of benefit to making radiation uniformity between stent struts and reducing radiation grads beyond the edge of stent.

  9. The Lifeworld Earth and a Modelled Earth

    Science.gov (United States)

    Juuti, Kalle

    2014-01-01

    The goal of this paper is to study the question of whether a phenomenological view of the Earth could be empirically endorsed. The phenomenological way of thinking considers the Earth as a material entity, but not as an object as viewed in science. In the learning science tradition, tracking the process of the conceptual change of the shape of the…

  10. The Lifeworld Earth and a Modelled Earth

    Science.gov (United States)

    Juuti, Kalle

    2014-01-01

    The goal of this paper is to study the question of whether a phenomenological view of the Earth could be empirically endorsed. The phenomenological way of thinking considers the Earth as a material entity, but not as an object as viewed in science. In the learning science tradition, tracking the process of the conceptual change of the shape of the…

  11. Visualizing alternative phosphorus scenarios for future food security

    Directory of Open Access Journals (Sweden)

    Tina-Simone Neset

    2016-10-01

    Full Text Available The impact of global phosphorus scarcity on food security has increasingly been the focus of scientific studies over the past decade. However, systematic analyses of alternative futures for phosphorus supply and demand throughout the food system are still rare and provide limited inclusion of key stakeholders. Addressing global phosphorus scarcity requires an integrated approach exploring potential demand reduction as well as recycling opportunities. This implies recovering phosphorus from multiple sources, such as food waste, manure and excreta, as well as exploring novel opportunities to reduce the long-term demand for phosphorus in food production such as changing diets. Presently, there is a lack of stakeholder and scientific consensus around priority measures. To therefore enable exploration of multiple pathways and facilitate a stakeholder dialogue on the technical, behavioral and institutional changes required to meet long-term future phosphorus demand, this paper introduces an interactive web-based tool, designed for visualizing global phosphorus scenarios in real-time. The interactive global phosphorus scenario tool builds on several demand and supply side measures that can be selected and manipulated interactively by the user. It provides a platform to facilitate stakeholder dialogue to plan for a soft landing and identify a suite of concrete priority options, such as investing in agricultural phosphorus use efficiency, or renewable fertilizers derived from phosphorus recovered from wastewater and food waste, to determine how phosphorus demand to meet future food security could be attained on a global scale in 2040 and 2070. This paper presents four example scenarios, including (1 the potential of full recovery of human excreta, (2 the challenge of a potential increase in non-food phosphorus demand, (3 the potential of a decreased animal product consumption, and (4 the potential decrease in phosphorus demand from increased efficiency

  12. Visualizing Alternative Phosphorus Scenarios for Future Food Security.

    Science.gov (United States)

    Neset, Tina-Simone; Cordell, Dana; Mohr, Steve; VanRiper, Froggi; White, Stuart

    2016-01-01

    The impact of global phosphorus scarcity on food security has increasingly been the focus of scientific studies over the past decade. However, systematic analyses of alternative futures for phosphorus supply and demand throughout the food system are still rare and provide limited inclusion of key stakeholders. Addressing global phosphorus scarcity requires an integrated approach exploring potential demand reduction as well as recycling opportunities. This implies recovering phosphorus from multiple sources, such as food waste, manure, and excreta, as well as exploring novel opportunities to reduce the long-term demand for phosphorus in food production such as changing diets. Presently, there is a lack of stakeholder and scientific consensus around priority measures. To therefore enable exploration of multiple pathways and facilitate a stakeholder dialog on the technical, behavioral, and institutional changes required to meet long-term future phosphorus demand, this paper introduces an interactive web-based tool, designed for visualizing global phosphorus scenarios in real time. The interactive global phosphorus scenario tool builds on several demand and supply side measures that can be selected and manipulated interactively by the user. It provides a platform to facilitate stakeholder dialog to plan for a soft landing and identify a suite of concrete priority options, such as investing in agricultural phosphorus use efficiency, or renewable fertilizers derived from phosphorus recovered from wastewater and food waste, to determine how phosphorus demand to meet future food security could be attained on a global scale in 2040 and 2070. This paper presents four example scenarios, including (1) the potential of full recovery of human excreta, (2) the challenge of a potential increase in non-food phosphorus demand, (3) the potential of decreased animal product consumption, and (4) the potential decrease in phosphorus demand from increased efficiency and yield gains in

  13. Peak phosphorus - peak food? The need to close the phosphorus cycle.

    Science.gov (United States)

    Rhodes, Christopher J

    2013-01-01

    The peak in the world production of phosphorus has been predicted to occur in 2033, based on world reserves of rock phosphate (URR) reckoned at around 24,000 million tonnes (Mt), with around 18,000 Mt remaining. This figure was reckoned-up to 71,000 Mt, by the USGS, in 2012, but a production maximum during the present century is still highly probable. There are complex issues over what the demand will be for phosphorus in the future, as measured against a rising population (from 7 billion to over 9 billion in 2050), and a greater per capita demand for fertiliser to grow more grain, in part to feed animals and meet a rising demand for meat by a human species that is not merely more populous but more affluent. As a counterweight to this, we may expect that greater efficiencies in the use of phosphorus - including recycling from farms and of human and animal waste - will reduce the per capita demand for phosphate rock. The unseen game changer is peak oil, since phosphate is mined and recovered using machinery powered by liquid fuels refined from crude oil. Hence, peak oil and peak phosphorus might appear as conjoined twins. There is no unequivocal case that we can afford to ignore the likelihood of a supply-demand gap for phosphorus occurring sometime this century, and it would be perilous to do so.

  14. Organic Geochemistry Data of Alaska DDS-59 Version 1.0

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The U. S. Geological Survey Central Energy Resources Science Center's Organic Geochemistry Laboratory is a research laboratory devoted to the investigation of the...

  15. Anisotropic Thermal Conductivity of Exfoliated Black Phosphorus.

    Science.gov (United States)

    Jang, Hyejin; Wood, Joshua D; Ryder, Christopher R; Hersam, Mark C; Cahill, David G

    2015-12-22

    The anisotropic thermal conductivity of passivated black phosphorus (BP), a reactive two-dimensional material with strong in-plane anisotropy, is ascertained. The room-temperature thermal conductivity for three crystalline axes of exfoliated BP is measured by time-domain thermo-reflectance. The thermal conductivity along the zigzag direction is ≈2.5 times higher than that of the armchair direction.

  16. Syntheses of Novel Nitrogen and Phosphorus Heterocycles.

    Science.gov (United States)

    2014-09-26

    some of the interaction products was associated with ammonia elimination. Depending on reaction conditions, specific phosphorus-containing compounds...TABLE OF CONTENTS iv LIST OF TABLES v LIST OF FIGURES vi 1. ABSTRACT 1 2. INTRODUCTION 3 3. RESULTS AND DISCUSSION 4 3.1 Attempted synthesis of fused ring...addition compounds Both linear and cyclic materials were identified. The ation of some of the inter- action products was associated with ammonia

  17. Sustainable Hydrogen Photoproduction by Phosphorus-Deprived Marine Green Microalgae Chlorella sp.

    Directory of Open Access Journals (Sweden)

    Khorcheska Batyrova

    2015-01-01

    Full Text Available Previously it has been shown that green microalga Chlamydomonas reinhardtii is capable of prolonged H2 photoproduction when deprived of sulfur. In addition to sulfur deprivation (-S, sustained H2 photoproduction in C. reinhardtii cultures can be achieved under phosphorus-deprived (-P conditions. Similar to sulfur deprivation, phosphorus deprivation limits O2 evolving activity in algal cells and causes other metabolic changes that are favorable for H2 photoproduction. Although significant advances in H2 photoproduction have recently been realized in fresh water microalgae, relatively few studies have focused on H2 production in marine green microalgae. In the present study phosphorus deprivation was applied for hydrogen production in marine green microalgae Chlorella sp., where sulfur deprivation is impossible due to a high concentration of sulfates in the sea water. Since resources of fresh water on earth are limited, the possibility of hydrogen production in seawater is more attractive. In order to achieve H2 photoproduction in P-deprived marine green microalgae Chlorella sp., the dilution approach was applied. Cultures diluted to about 0.5–1.8 mg Chl·L−1 in the beginning of P-deprivation were able to establish anaerobiosis, after the initial growth period, where cells utilize intracellular phosphorus, with subsequent transition to H2 photoproduction stage. It appears that marine microalgae during P-deprivation passed the same stages of adaptation as fresh water microalgae. The presence of inorganic carbon was essential for starch accumulation and subsequent hydrogen production by microalgae. The H2 accumulation was up to 40 mL H2 gas per 1iter of the culture, which is comparable to that obtained in P-deprived C. reinhardtii culture.

  18. Geobiology: A Conceptual Framework for Understanding Earth's Surface

    Science.gov (United States)

    Sumner, D. Y.

    2016-12-01

    A topic of study becomes a new field when it provides a useful conceptual framework for understanding suites of important processes. Geobiology integrates microbial biology with Earth sciences in a way that allows us to ask - and answer - deeper questions about Earth and the life on it. Recent studies of the oxidation of Earth's surface exemplify the impact of Geobiology as a new field. For decades, scientists have understood that Earth's surface was oxidized by photosynthesis. Geochemical records indicate dramatic redox changes both globally, e.g. the loss of MIF sulfur signatures due to formation of an ozone layer, and locally, as preserved in sedimentary rocks. However, these records depend critically on the dynamics of both the global biosphere and local microbial ecology. For example, an increase in global redox due to photosynthetic iron oxidation has different biogeochemical implications than an increase from oxygenic photosynthesis; O2 reacts very differently with organic matter and minerals than iron oxyhydroxides do, influencing microbial ecology as well as potential geochemical signatures in sedimentary rocks. Thus, studies of modern microbial communities provide insights into the interactions among metabolisms and geochemical gradients that have shaped Earth's redox history. For example, the ability of cyanobacteria to create O2 oases in benthic mats and soils on land provides a new framework for evaluating redox-sensitive elemental fluxes to the ocean. Similarly, genomic studies of Cyanobacteria have revealed close relatives, Melainabacteria, that are mostly obligate anaerobes. The evolutionary relationships between these two groups, as preserved in their genomes, reflect important microbial processes that led to oxidation of Earth's surface. By combining insights from microbial biology and sedimentary geochemistry, geobiologists will develop significantly more accurate models of the interactions between life and Earth.

  19. Where is the Phosphorus in Cometary Volatiles?

    Science.gov (United States)

    Boice, Daniel C.; de Almeida, Amaury

    2015-08-01

    Phosphorus is a key element in all living organisms but its role in life's origin is not well understood. Phosphorus-bearing compounds have been observed in space, are ubiquitous in meteorites in small quantities, and have been detected as part of the dust component in comets Halley and Wild 2. However, searches for P-bearing species in the gas phase in cometary comae have been unsuccessful. We present results of the first quantitative study of P-bearing molecules in comets to identify likely species containing phosphorus. We found reaction pathways of gas-phase and photolytic chemistry for simple P-bearing molecules likely to be found in comets and important for prebiotic chemistry. We hope to aid future searches for this important element, especially the Rosetta Mission to Comet 67P/Churyumov-Gerasimenko, possibly shedding light on issues of comet formation (time and place) and understanding prebiotic to biotic evolution of life.Acknowledgements: We greatly appreciate support from the NSF Planetary Astronomy Program under Grant No. 0908529 and the Instituto de Astronomia, Geofísica e Ciências Atmosféricas at the University of São Paulo.

  20. [Information about phosphorus additives and nutritional counseling].

    Science.gov (United States)

    Kido, Shinsuke; Nomura, Kengo; Sasaki, Shohei; Shiozaki, Yuji; Segawa, Hiroko; Tatsumi, Sawako

    2012-10-01

    Hyperphosphatemia is a common disorder in patients with chronic kidney disease (CKD) , and may result in hyperparathyroidism and renal osteodystrophy. Hyperphosphatemia also may contribute to deterioration vascular calcification and increase mortality. Hence, correction and prevention of hyperphosphatemia is a main component of the management of CKD. This goal is usually approached both by administering phosphorus binders and by restricting dietary phosphorus (P) intake. Dietary intake of phosphorus (P) is derived largely from foods with high protein content or food additives and is an important determinant of P balance in patient with CKD. Food additives (PO4) can dramatically increase the amount of P consumed in the daily diet, especially because P is more readily absorbed in its inorganic form. In addition, information about the P content and type in prepared foods is often unavailable or misleading. Therefore, during dietary counseling of patients with CKD, we recommended that they consider both the absolute dietary P content and the P-to-protein ratio of foods and meals including food additives.

  1. Distribution behavior of phosphorus in the coal-based reduction of high-phosphorus-content oolitic iron ore

    Institute of Scientific and Technical Information of China (English)

    Yong-sheng Sun; Yue-xin Han; Peng Gao; Duo-zhen Ren

    2014-01-01

    This study focuses on the reduction of phosphorus from high-phosphorus-content oolitic iron ore via coal-based reduction. The distribution behavior of phosphorus (i.e., the phosphorus content and the phosphorus distribution ratio in the metal, slag, and gas phases) during reduction was investigated in detail. Experimental results showed that the distribution behavior of phosphorus was strongly influenced by the reduction temperature, the reduction time, and the C/O molar ratio. A higher temperature and a longer reaction time were more favor-able for phosphorus reduction and enrichment in the metal phase. An increase in the C/O ratio improved phosphorus reduction but also hin-dered the mass transfer of the reduced phosphorus when the C/O ratio exceeded 2.0. According to scanning electron microscopy analysis, the iron ore was transformed from an integral structure to metal and slag fractions during the reduction process. Apatite in the ore was reduced to P, and the reduced P was mainly enriched in the metal phase. These results suggest that the proposed method may enable utilization of high-phosphorus-content oolitic iron ore resources.

  2. Phosphorus removal and recovery from domestic wastewater in a novel process of enhanced biological phosphorus removal coupled with crystallization.

    Science.gov (United States)

    Zou, Haiming; Wang, Yan

    2016-07-01

    A new process of enhanced biological phosphorus removal coupled with crystallization recovery of phosphorus was developed here, where the feasibility of nutrients removal and potential for phosphorus recovery from domestic wastewater was further assessed. Results showed that an excellent nutrients removal and phosphorus recovery performance was achieved, in which the averaged COD, PO4(3-)-P and NO3(-)-N removal efficiencies were 82.6%, 87.5% and 91.6%, respectively and a total of 59.3% of phosphorus was recovered as hydroxyapatite. What's more, crystallization recovery of phosphorus greatly enhanced the biological phosphorus removal efficiency. After the incorporation of the phosphorus recovery column via side-stream, the phosphorus concentration of effluent was significantly decreased ranging from 1.24mg/L to 0.85mg/L, 0.52mg/L and 0.41mg/L at the lateral flow ratios of 0, 0.1, 0.2 and 0.3, respectively. The results obtained here would be beneficial to provide a prospective alternative for phosphorus removal and recovery from wastewater. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Geochronology, geochemistry and tectonic implications of Xiongshan diabasic dike swarm, northern Fujian

    Institute of Scientific and Technical Information of China (English)

    任胜利; 李继亮; 周新华; 孙敏

    1997-01-01

    Sm/Nd isotopic age determination showed that Xiongshan dike swarm was at 585.7 Ma±30 Ma. The trace element geochemistry and Sr/Nd/Pb isotope geochemistry studies indicate that the dike swarm was products of back-arc basin spreading ridge and the magma originated from the depleted mantle region which was metasomatized by LTLE-rich liquids/melts derived from subduction slab.

  4. Temporal Geochemistry Data from Five Springs in the Cement Creek Watershed, San Juan County, Colorado

    Science.gov (United States)

    Johnson, Raymond H.; Wirt, Laurie; Leib, Kenneth J.

    2008-01-01

    Temporal data from five springs in the Cement Creek watershed, San Juan County, Colorado provide seasonal geochemical data for further research in the formation of ferricretes. In addition, these data can be used to help understand the ground-water flow system. The resulting data demonstrate the difficulty in gathering reliable seasonal data from springs, show the unique geochemistry of each spring due to local geology, and provide seasonal trends in geochemistry for Tiger Iron Spring.

  5. Seasonal variations in pore water and sediment geochemistry of littoral lake sediments (Asylum Lake, MI, USA)

    OpenAIRE

    Miller Douglas; Haas Johnson R; Koretsky Carla M; Ndenga Noah T

    2006-01-01

    Abstract Background Seasonal changes in pore water and sediment redox geochemistry have been observed in many near-surface sediments. Such changes have the potential to strongly influence trace metal distribution and thus create seasonal fluctuations in metal mobility and bioavailability. Results Seasonal trends in pore water and sediment geochemistry are assessed in the upper 50 cm of littoral kettle lake sediments. Pore waters are always redox stratified, with the least compressed redox str...

  6. Assessment of Non-Point Source Total Phosphorus Pollution from Different Land Use and Soil Types in a Mid-High Latitude Region of China

    Directory of Open Access Journals (Sweden)

    Zhiwei Wang

    2016-11-01

    Full Text Available The transport characteristics of phosphorus in soil and the assessment of its environmental risk have become hot topics in the environmental and agricultural fields. The Sanjiang Plain is an important grain production base in China, and it is characterised by serious land use change caused by large-scale agricultural exploitation. Agricultural inputs and tillage management have destroyed the soil nutrient balance formed over long-term conditions. There are few studies on non-point source phosphorus pollution in the Sanjiang Plain, which is the largest swampy low plain in a mid-high-latitude region in China. Most studies have focused on the water quality of rivers in marsh areas, or the export mechanism of phosphorus from specific land uses. They were conducted using experimental methods or empirical models, and need further development towards mechanism models and the macro-scale. The question is how to find a way to couple processes in phosphorus cycling and a distributed hydrological model considering local hydrological features. In this study, we report an attempt to use a distributed phosphorus transport model to analyse non-point source total phosphorus pollution from different land uses and soil types on the Sanjiang Plain. The total phosphorus concentration generally shows an annually increasing trend in the study area. The total phosphorus load intensity is heterogeneous in different land use types and different soil types. The average total phosphorus load intensity of different land use types can be ranked in descending order from paddy field, dry land, wetlands, grassland, and forestland. The average total phosphorus load intensity of different soil types can be ranked in descending order: paddy soil, bog soil, planosol, meadow soil, black soil, and dark brown earth. The dry land and paddy fields account for the majority of total phosphorus load in the study area. This is mainly caused by extensive use of phosphate fertilizer on the

  7. Application of factorial kriging analysis to the FOREGS European topsoil geochemistry database.

    Science.gov (United States)

    Imrie, Claire E; Korre, Anna; Munoz-Melendez, Gabriela; Thornton, Iain; Durucan, Sevket

    2008-04-01

    Concern about increasing levels of trace elements in the environment has led to the development and implementation of a global programme to determine the current baseline levels of these chemicals in the Earth's surface. The FORum of European Geological Surveys (FOREGS) has recently published a geochemical database for Europe, while progress on similar databases is continuing in other major regions of the world. The FOREGS database comprises multimedia samples collected at a resolution of approximately 72x72 km from 26 European countries. This enables the investigation of the factors governing geochemical variation on a continental scale, potentially allowing contributions of natural processes to be appreciated prior to setting environmental quality standards. This paper investigates the variation in European topsoil geochemistry using factorial kriging analysis, which performs principal components analysis at different spatial scales. The results are interpreted with the aid of a GIS database. Four spatial scales were identified: a nugget component representing variation over a range less than the sampling density; a 'short' scale component with a range of 296 km; an 'intermediate' scale component (875 km); and a 'long' scale component (1750 km). The first three principal components (PCs) of the nugget covariance matrix explained 22.2% of the overall variance, representing local variation in geology, land use, weathering and organic matter content. The first two PCs of the short range structure explained 12.6% of the variance, representing variation according to the major structural divisions of Europe, and to carbonate content. The first PC of the intermediate structure explained 7.2% of the variance and was found to relate to glacial history and Quaternary deposition. Finally, the first three PCs of the long range structure explained 29.6% of the variance and represented variation due to mineralisation, soil texture, climate and possibly anthropogenic

  8. Data-driven Approaches to Teaching Stable Isotopes in Hydrology and Environmental Geochemistry

    Science.gov (United States)

    Jefferson, A.; Merchant, W. R.; Dees, D.; Griffith, E. M.; Ortiz, J. D.

    2016-12-01

    Stable isotopes have revolutionized our understanding of watershed hydrology and other earth science processes. However, students may struggle to correctly interpret isotope ratios and few students understand how isotope measurements are made. New laser-based technologies lower the barrier to entry for giving students hands on experience with isotope measurements and data analysis. We hypothesizedthat integrating such activities into the curriculum would increase student content knowledge, perceptions, and motivation to learn. This project assessed the impact that different pedagogical approaches have on student learning of stable isotope concepts in upper-division geoscience courses. An isotope hydrograph separation module was developed and taught for a Watershed Hydrology course, and a Rayleigh distillation activity was developed and deployed for Environmental Geochemistry and Sedimentology/Stratigraphy classes. Groups of students were exposed to this content via (1) a lecture-only format; (2) a paper-based data analysis activity; and (3) hands-on data collection, sometimes including spectrometer analysis. Pre- and post-tests measured gains in content knowledge while approaches to learning and motivational questionnaires instruments were used to identify the effects of the classroom environment on learning approaches and motivation. Focus group interviews were also conducted to verify the quantitative data. All instructional styles appear to be equally effective at increasing student content knowledge of stable isotopes in the geosciences, but future studies need to move beyond "exam question" style assessment of learning. Our results may reflect that hands-on experiences are not new to upper-level geosciences students, because this is the way that many classes are taught in the geosciences (labs, field trips). Thus, active learning approaches may not have had the impact they would with other groups. The "messiness" of hands-on activities and authentic research

  9. Talos Dome ice Core (East Antarctica) Mieral Dust Iron Geochemistry of the Last 160 ky.

    Science.gov (United States)

    Maggi, V.; Augusto, M.; Dariush, H.; Giannantonio, C.; Delmonte, B.; Baccolo, G.

    2015-12-01

    Earth's radiation budget is affected by the mineral dust blowing up from arid and semi-arid sources areas. It can act as negative radiative forcing (mainly by sunlight backscattering out to the space) and positive forcing (as absorbing solar and infrared radiation). The combination of absorption and reflection of solar radiation caused by dust microparticles can lead to a net (longwave and shortwave) negative radiative forcing at the surface and at the top of atmosphere, in opposition to the greenhouse gases.Transported from the Southern Hemisphere continental landmasses to the remote East Antarctic plateau (long-term transport), mineral dust travels in the high troposphere and interacts with climate. However, processes occurring during atmospheric transport from source areas to polar ice sheets are responsible for the strong reduction of dust concentration and size in the polar atmosphere. Moreover, concentration and grain size, such as mineralogy and shape of dust and aerosols, influencing the dust radiative effect are still poorly known.We present here new Synchrotron radiation spectroscopy data, i.e., X-ray Absorption Near Edge Structure (XANES) at the Fe and Ti K edge from Talos Dome dust samples (72°49'S, 159°110'E; 2315 m a.s.l.) spanning the last two climate cycles (ca. 250 kyrs). The analysis allows the reconstruction of dust geochemistry and Fe and Ti coordination state in selected climatic periods. Dust composition changes in time provide an important contribution to the scientific knowledge on palaeoclimate changes in near coastal regions of the Antarctic ice sheet and novel information on possible changes occurred at the source areas.

  10. EarthKAM

    Data.gov (United States)

    National Aeronautics and Space Administration — Sponsored by NASA, EarthKAM (Earth Knowledge Acquired by Middle School Students) is an educational outreach program allowing middle school students to take pictures...

  11. Earth on the Move.

    Science.gov (United States)

    Naturescope, 1987

    1987-01-01

    Provides background information on the layers of the earth, the relationship between changes on the surface of the earth and its insides, and plate tectonics. Teaching activities are included, with some containing reproducible worksheets and handouts to accompany them. (TW)

  12. NASA Earth Exchange (NEX)

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA Earth Exchange (NEX) represents a new platform for the Earth science community that provides a mechanism for scientific collaboration and knowledge sharing....

  13. Biological phosphorus removal inhibition by roxarsone in batch culture systems.

    Science.gov (United States)

    Guo, Qingfeng; Liu, Li; Hu, Zhenhu; Chen, Guowei

    2013-06-01

    Roxarsone has been extensively used in the feed of animals, which is usually excreted unchanged in the manure and eventually enter into animal wastewater, challenging the biological phosphorus removal processes. Knowledge of its inhibition effect is key for guiding treatment of roxarsone-contaminated wastewater, and is unfortunately keeping unclear. We study the inhibition of roxarsone on biological phosphorus removal processes for roxarsone-contaminated wastewater treatment, in terms of the removal and rates of chemical oxygen demand (COD), phosphate. Results showed that presence of roxarsone considerably limited the COD removals, especially at roxarsone concentration exceeding 40 mg L(-1). Additionally, roxarsone inhibited both phosphorus release and uptake processes, consistent with the phosphate profiles during the biological phosphorus removal processes; whereas, roxarsone is more toxic to phosphorus uptake process, than release function. The results indicated that it is roxarsone itself, rather than the inorganic arsenics, inhibit biological phosphorus removal processes within both aerobic and anaerobic roxarsone-contaminated wastewater treatment.

  14. Biological phosphorus uptake under anoxic and aerobic conditions

    DEFF Research Database (Denmark)

    Kerrn-Jespersen, Jens Peter; Henze, Mogens

    1993-01-01

    Biological phosphorus removal was investigated under anoxic and aerobic conditions. Tests were made to establish whether phosphorus accumulating bacteria can take up phosphate under anoxic conditions and thus utilise nitrate as oxidant. Furthermore, it was tested how the amount of organic matter...... sludge from two different pilot plants incorporating phosphorus removal. The results showed that the phosphorus accumulating bacteria can be divided into two groups in respect of process; one group capable of utilising only oxygen as oxidant and another group capable of utilising both oxygen and nitrate...... taken up by the phosphorus accumulating bacteria during the anaerobic phase affects the total denitrification rate, as well as the rate at which the phosphorus accumulating bacteria take up phosphate under anoxic conditions. The tests were conducted as batch experiments in 21. reactors with activated...

  15. Geochemistry and origin of metamorphosed mafic rocks from the Lower Paleozoic Moretown and Cram Hill Formations of North-Central Vermont: Delamination magmatism in the western New England appalachians

    Science.gov (United States)

    Coish, Raymond; Kim, Jonathan; Twelker, Evan; Zolkos, Scott P.; Walsh, Gregory J.

    2015-01-01

    The Moretown Formation, exposed as a north-trending unit that extends from northern Vermont to Connecticut, is located along a critical Appalachian litho-tectonic zone between the paleomargin of Laurentia and accreted oceanic terranes. Remnants of magmatic activity, in part preserved as metamorphosed mafic rocks in the Moretown Formation and the overlying Cram Hill Formation, are a key to further understanding the tectonic history of the northern Appalachians. Field relationships suggest that the metamorphosed mafic rocks might have formed during and after Taconian deformation, which occurred at ca. 470 to 460 Ma. Geochemistry indicates that the sampled metamorphosed mafic rocks were mostly basalts or basaltic andesites. The rocks have moderate TiO2 contents (1–2.5 wt %), are slightly enriched in the light-rare earth elements relative to the heavy rare earths, and have negative Nb-Ta anomalies in MORB-normalized extended rare earth element diagrams. Their chemistry is similar to compositions of basalts from western Pacific extensional basins near volcanic arcs. The metamorphosed mafic rocks of this study are similar in chemistry to both the pre-Silurian Mount Norris Intrusive Suite of northern Vermont, and also to some of Late Silurian rocks within the Lake Memphremagog Intrusive Suite, particularly the Comerford Intrusive Complex of Vermont and New Hampshire. Both suites may be represented among the samples of this study. The geochemistry of all samples indicates that parental magmas were generated in supra-subduction extensional environments during lithospheric delamination.

  16. Stable (C, O, S isotopes and whole-rock geochemistry of carbonatites from Alto Paranaíba Igneous Province, SE Brazil

    Directory of Open Access Journals (Sweden)

    Caroline Siqueira Gomide

    Full Text Available ABSTRACT: The present work investigates the relationship between whole-rock geochemistry and stable isotope composition from carbonatites belonging to the Tapira, Araxá, Salitre, Serra Negra, Catalão I, and Catalão II alkaline-carbonatite complexes of the Alto Paranaiba Igneous Province (APIP, central Brazil and from the Jacupiranga Complex, of the Ponta Grossa Province, southeast Brazil. The APIP complexes are ultrapotassic, comprising bebedourites, phoscorites, nelsonites, and carbonatites, whereas Jacupiranga is a sodic complex composed of ijolite-series rocks, syenites, carbonatites, and alkaline gabbros. The geochemistry data allied to mineralogical constraints allowed us to classify the carbonatites into five groups, and to devise a chemical index (BaO/(BaO+SrO to gauge the magmatic evolution of the studied carbonatites.The APIP carbonatites evolve from apatite-rich calciocarbonatites toward Ba-, Sr-, and rare earth element (REE-rich magnesiocarbonatites. This evolution is mostly driven by apatite, phlogopite, dolomite, and calcite fractionation and consequent enrichment in monazite, norsethite, and strontianite. Stable isotope data show a wide diversity of petrogenetic processes in play at the APIP, relatively to the Jacupiranga Complex, which is interpreted as a result of the shallower intrusion levels of the APIP complexes. Such shallower emplacement, at low lithostatic pressure, allowed for a complex interplay of fractional crystallization, liquid immiscibility, degassing, and interaction with hydrothermal and carbohydrothermal systems.

  17. Schreibersite on the early Earth: Scenarios for prebiotic phosphorylation

    Directory of Open Access Journals (Sweden)

    Matthew A. Pasek

    2017-03-01

    Full Text Available The mineral schreibersite, (Fe,Ni3P, provides a reactive source of phosphorus capable of forming phosphorylated molecules. These molecules may have been an important component of prebiotic chemistry, allowing their build-up and eventual commencement of autopoiesis. Discussed here are potential geochemical routes to providing schreibersite, as a potentially important prebiotic mineral, to the Hadean Earth. Two routes are identified: delivery of phosphides by meteoritic material and the reduction of phosphates to phosphides by high-temperature, low-redox conditions. About 1–10% of all crustal phosphorus is estimated to have been in schreibersite during the Hadean, making the long-term reaction of this mineral with organic-laden water plausible for many years. Ultimately, such conditions would have been conducive to the formation of life as we know it today.

  18. Gas Geochemistry of the Dogger Geothermal Aquifer (Paris Basin, France)

    Energy Technology Data Exchange (ETDEWEB)

    Criaud, A.; Fouillac, C.; Marty, B.; Brach, M.; Wei, H.F.

    1987-01-20

    The low enthalpy program developed in the Paris Basin provides the opportunity for studying the gas geochemistry of the calcareous aquifer of the Dogger. Hydrocarbons and CO{sub 2} are mainly biogenic, He displays high concentrations. He, Ar and N{sub 2} have multiple origins (radioactive decay, atmospheric migration, biochemical processes). The distribution of the gases in the zones of the basin varies in relation to the general chemistry, sedimentology and hydrodynamics. The gas geothermometers do not apply to this environment but useful estimations of the redox potential of the fluid can be derived from CO{sub 2}/CH{sub 4} and N{sub 2}/NH{sub 4}{sup +} ratios. H{sub 2} and H{sub 2}S are involved in corrosion processes and scaling in the pipes. 12 refs., 3 figs., 2 tabs.

  19. Summary report on the geochemistry of Yucca Mountain and environs

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, W.R.; Wolfsberg, K.; Rundberg, R.S.

    1982-12-01

    This report gives a detailed description of work at Los Alamos that will help resolve geochemical issues pertinent to siting a high-level nuclear waste repository in tuff at Yucca Mountain, Nevada. It is necessary to understand the properties and setting of the host tuff because this rock provides the first natural barrier to migration of waste elements from a repository. The geochemistry of tuff is being investigated with particular emphasis on retardation processes. This report addresses the various aspects of sorption by tuff, physical and chemical makeup of tuff, diffusion processes, tuff/groundwater chemistry, waste element chemistry under expected repository conditions, transport processes involved in porous and fracture flow, and geochemical and transport modeling.

  20. Workshop on fundamental geochemistry needs for nuclear waste isolation

    Energy Technology Data Exchange (ETDEWEB)

    Heiken, J.H. (ed.)

    1985-09-01

    In their deliberations, workshop participants did not attempt to incorporate the constraints that the 1982 National Nuclear Waste Management Policy Act placed upon the site-specific investigations. In particular, there was no attempt to (1) identify the research areas that apply most strongly to a particular potential repository site, (2) identify the chronological time when the necessary data or knowledge could be available, or (3) include a sensitivity analysis to prioritize and limit data needs. The workshop participants felt these are the purview of the site-specific investigations; the purpose of the workshop was to discuss the generic geochemistry research needs for a nuclear waste repository among as broad spectrum of individual scientists as possible and to develop a consensus of what geochemical information is important and why.

  1. Study on surface geochemistry and microbiology for hydrocarbon exploration

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-01

    The test results of the experimental device for extraction of dissolved gases from water show that the device can be utilized for the gas geochemistry of water. The device is capable of determining hydrocarbon gases in water to the concentration of less than 5 x 10{sup -4} ml/l of water. According to the results of microbiological studies, the plate count technique can be a useful supplementary method for hydrocarbon exploration. This is based on the facts that the average survival rate to hydrocarbons (pentane, hexane) for heterotrophs is higher in the area known as containing considerable hydrocarbon gases than other areas in the Pohang region. However, it is still necessary to develop techniques to treat the bacteria with gaseous hydrocarbons. (author). 2 figs., 41 tabs.

  2. Late Eocene impact microspherules - Stratigraphy, age and geochemistry

    Science.gov (United States)

    Keller, G.; D'Hondt, S. L.; Orth, C. J.; Gilmore, J. S.; Oliver, P. Q.; Shoemaker, E. M.; Molina, E.

    1987-03-01

    The stratigraphy, faunal changes, and geochemistry of deep-sea sediments associated with late Eocene microtektite and microspherule layers are reported. Microprobe analyses of major element compositions of microspherules show that, although there is some compositional overlap in all three late Eocene layers as well as with the Pleistocene Australasian and Ivory Coast microtektites, each microspherule population has characteristic compositional features. All three microspherule layers are associated with decreased carbonate, possibly due to a sudden productivity change, increased dissolution as a result of sea-level and climate fluctuations, or impact events. A discovery of microtektites in the Gl. cerroazulensis Zone off the New Jersey coast extends the North American strewn field from the Caribbean to the northwest Atlantic.

  3. Microbial phytases in phosphorus acquisition and plant growth promotion

    OpenAIRE

    2011-01-01

    Phosphorus (P) is one of the major constituents in energy metabolism and biosynthesis of nucleic acids and cell membranes with an important role in regulation of a number of enzymes. Soil phosphorous is an important macronutrient for plant growth. Phosphorus deficiency in soil is a major problem for agricultural production. Total soil P occurs in either organic or in organic form. Phytic acid as phytate (salts of phytic acid) is the major form of organic phosphorus in soil and it is not readi...

  4. Metabolism of nonparticulate phosphorus in an acid bog lake

    Energy Technology Data Exchange (ETDEWEB)

    Koenings, J. P.

    1977-01-01

    In North Gate Lake, an acid bog lake located on the northern Michigan-Wisconsin border, U.S.A., the algal nutrient inorganic phosphate (FRP) is not detectable by chemical means. Organic phosphorus (FUP) represents 100% of the detectable filterable phosphorus. The availability and cycling of this organic fraction are of considerable interest in regard to the primary productivity of this system. To clarify these relationships, the cycling of nonparticulate forms of phosphorus found in the epilimnion of this lake was studied.

  5. ESR studies of high-energy phosphorus-ion implanted synthetic diamond crystals

    Energy Technology Data Exchange (ETDEWEB)

    Isoya, J. [University of Library and Information Science, Tsukuba, Ibaraki (Japan); Kanda, H.; Morita, Y.; Ohshima, T.

    1997-03-01

    Phosphorus is among potential n-type dopants in diamond. High pressure synthetic diamond crystals of type IIa implanted with high energy (9-18 MeV) phosphorus ions have been studied by using electron spin resonance (ESR) technique. The intensity and the linewidth of the ESR signal attributed to the dangling bond of the amorphous phase varied with the implantation dose, suggesting the nature of the amorphization varies with the dose. The ESR signals of point defects have been observed in the low dose as-implanted crystals and in the high dose crystals annealed at high temperature and at high pressure. (author)

  6. Determination of phosphorus in natural waters: A historical review.

    Science.gov (United States)

    Worsfold, Paul; McKelvie, Ian; Monbet, Phil

    2016-04-28

    The aim of this paper is to introduce a virtual special issue that reviews the development of analytical approaches to the determination of phosphorus species in natural waters. The focus is on sampling and sample treatment, analytical methods and quality assurance of the data. The export of phosphorus from anthropogenic activities (from diffuse and point sources) can result in increased primary production and eutrophication, and potentially the seasonal development of toxic algal blooms, which can significantly impact on water quality. Therefore the quantification of phosphorus species in natural waters provides important baseline data for studying aquatic phosphorus biogeochemistry, assessing ecosystem health and monitoring compliance with legislation.

  7. Phosphorus removal from domestic wastewater by Echinodorus cordifolius L.

    Science.gov (United States)

    Torit, Jirawan; Siangdung, Wipawan; Thiravetyan, Paitip

    2012-01-01

    This study was to use the plants to remove phosphorus from domestic wastewater which contained high phosphorus concentration. Six higher plant species such as Crinum asiaticum L., Echinodorus cordifolius L., Spathiphyllum clevelandii Schott, Rhizophora apiculata Blume, Thalia dealbata J.fraser., Heliconia psittacorum L.f. were screened for phosphorus removal. Plants were grown in the domestic wastewater and the remaining phosphorus-phosphate concentration in the systems was determined. The results indicated that among studied plants, Echinodorus cordifolius L. was the best for phosphorus removal. Using this plant will improve the quality of domestic wastewater which contained excess phosphorus concentration and induced eutrophication. The relationship between the plants, microorganisms, and soil in the system were also investigated. In this system, adsorption by soil was the major role for phosphorus removal (71%), followed by E. cordifolius (16%), microorganisms in domestic wastewater (7%), and microorganisms in soil (6%). These results indicated the ability of E. cordifolius to remove phosphorus which was superior to that of the microorganisms in the system. Moreover, the rapid phosphorus removal was concomitant to the growth, photosynthesis activity and biomass of E. cordifolius grown in domestic wastewater. The C:N:P ratio of E. cordifolius tissue in the system indicated that elements were taken up from the wastewater. From these results, the suitability of E. cordifolius for domestic wastewater treatment was confirmed.

  8. NMR and mass spectrometry of phosphorus in wetlands

    Science.gov (United States)

    El-Rifai, H.; Heerboth, M.; Gedris, T.E.; Newman, S.; Orem, W.; Cooper, W.T.

    2008-01-01

    There is at present little information on the long-term stability of phosphorus sequestered in wetlands. Phosphorus sequestered during high loading periods may be relatively unstable and easily remobilized following changes in nutrient status or hydrological regime, but the chemical forms of sequestered phosphorus that do remobilize are largely unknown at this time. A lack of suitable analytical techniques has contributed to this dearth of knowledge regarding the stability of soil organic phosphorus. We analysed phosphorus in soils from the 'head' of Rescue Strand tree island and an adjacent marsh in the Florida Everglades by 31P nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry. Tree islands are important areas of biodiversity within the Everglades and offer a unique opportunity to study phosphorus sequestration because they are exposed to large phosphorus loads and appear to be natural nutrient sinks. The 31P NMR profiling of extracts from surface and sediment samples in the tree island indicates that phosphorus input to Rescue Strand tree island soils is mostly in the form of inorganic ortho-phosphate and is either refractory when deposited or rapidly recycled by the native vegetation into a stable phosphorus pool largely resistant to re-utilization by plants or microbes. Mass spectrometry revealed the presence of inositol hexakisphosphate, a common organic monophosphate ester not previously observed in Everglades' soils. ?? 2008 The Authors.

  9. Role of extracellular exopolymers on biological phosphorus removal

    Institute of Scientific and Technical Information of China (English)

    LIU Ya-nan; XUE Gang; YU Shui-li; ZHAO Fang-bo

    2006-01-01

    Three sequencing batch reactors supplied with different carbon sources were investigated. The system supplied with glucose gained the best enhanced biological phosphorus removal although all of the three reactors were seeded from the same sludge. With the measurement of poly-β-hydroxyalkanoate (PHA) concentration, phosphorus content in sludge and extracellular exopolymers (EPS) with scanning electron microscopy (SEM) combined with energy dispersive spectrometry (EDS), it was found that the biosorption effect of EPS played an important role in phosphorus removal and that the amount of PHA at the end of anaerobic phase was not the only key factor to determine the following phosphorus removal efficiency.

  10. Phosphorus limitation in biofiltration for drinking water treatment

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Bacterial growth potential(BGP) method and two parallel pilot-scale biofilters were used to investigate phosphorus limitation and itseffect on the removal of organic matters in biofiltration for drinking water treatment. Addition of phosphorus can substantially increase the BGPsof the samples. Its effect was equivalent to that of addition of a mixture of various inorganic nutrients including phosphorus. The biofilter withphosphate added into its influent performed a higher biological stability of the effluent and a higher CODMn removal than the control filter. Theseresults suggested that phosphorus was the limiting nutrient in the biofiltration and the removal efficiency of organic matters could be improved byadding phosphate into the influent.

  11. Dietary phosphorus in bone health and quality of life.

    Science.gov (United States)

    Takeda, Eiji; Yamamoto, Hironori; Yamanaka-Okumura, Hisami; Taketani, Yutaka

    2012-06-01

    Awareness of phosphorus intake is important because both phosphorus deficiency and overloading impair bone health and quality of life. Phosphorus consumption is increasing in many countries. Most dietary phosphorus is contained in protein-rich foods such as meat, milk, cheese, poultry, fish, and processed foods that contain phosphate-based additives to improve their consistency and appearance. Elevation of extracellular phosphorus levels causes endothelial dysfunction and medial calcification, which are closely associated with the development of cardiovascular disease (CVD). Long-term excessive phosphorus loading, even if it does not cause hyperphosphatemia, can be a risk factor for CVD. In epidemiological studies, higher levels of phosphorus intake have been associated with reduced blood pressure. Interestingly, when examined further, phosphorus from dairy products, but not from other sources, was usually associated with lower blood pressure. A dietary approach to phosphorus reduction is particularly important to prevent bone impairment and CVD in patients with chronic kidney disease. In order to improve bone health and quality of life in the general population, the impact of phosphorous, including in processed foods, should be considered, and measures to indicate the amount of phosphorous in food products should be implemented.

  12. Contributions to total phosphorus intake: all sources considered.

    Science.gov (United States)

    Calvo, Mona S; Uribarri, Jaime

    2013-01-01

    High serum phosphorus is linked to poor health outcome and mortality in chronic kidney disease (CKD) patients before or after the initiation of dialysis. Dietary intake of phosphorus, a major determinant of serum phosphorus, seems to be systematically underestimated using the available software tools and generalized nutrient content databases. Several sources of dietary phosphorus including the addition of phosphorus ingredients in food processing, and phosphorus content of vitamin and mineral supplements and commonly used over-the-counter or prescription medications are not fully accounted for by the nutrient content databases and software programs in current clinical use or used in large population studies. In this review, we explore the many unknown sources of phosphorus in the food supply to identify all possible contributors to total phosphorus intake of Americans that have escaped inclusion in past intake estimates. Our goal is to help delineate areas for future interventions that will enable tighter control of dietary phosphorus intake, a critical factor to maintaining health and quality of life in CKD and dialysis patients.

  13. A novel approach for phosphorus recovery and no wasted sludge in enhanced biological phosphorus removal process with external COD addition.

    Science.gov (United States)

    Xia, Cheng-Wang; Ma, Yun-Jie; Zhang, Fang; Lu, Yong-Ze; Zeng, Raymond J

    2014-01-01

    In enhanced biological phosphorus removal (EBPR) process, phosphorus (P) in wastewater is removed via wasted sludge without actual recovery. A novel approach to realize phosphorus recovery with special external chemical oxygen demand (COD) addition in EBPR process was proposed. During the new operating approach period, it was found that (1) no phosphorus was detected in the effluent; (2) with an external addition of 10 % of influent COD amount, 79 % phosphorus in the wastewater influent was recovered; (3) without wasted sludge, the MLVSS concentration in the system increased from 2,010 to 3,400 mg/L and kept stable after day 11 during 24-day operating period. This demonstrates that the novel approach is feasible to realize phosphorus recovery with no wasted sludge discharge in EBPR process. Furthermore, this approach decouples P removal and sludge age, which may enhance the application of membrane bioreactor for P removal.

  14. Post-impact hydrothermal system geochemistry and mineralogy: Rochechouart impact structure, France.

    Science.gov (United States)

    Simpson, Sarah

    2014-05-01

    Hypervelocity impacts generate extreme temperatures and pressures in target rocks and may permanently alter them. The process of cratering is at the forefront of research involving the study of the evolution and origin of life, both on Mars and Earth, as conditions may be favourable for hydrothermal systems to form. Of the 170 known impact structures on Earth, over one-third are known to contain fossil hydrothermal systems [1]. The introduction of water to a system, when coupled with even small amounts of heat, has the potential to completely alter the target or host rock geochemistry. Often, the mineral assemblages produced in these environments are unique, and are useful indicators of post-impact conditions. The Rochechouart impact structure in South-Central France is dated to 201 ± 2 Ma into a primarily granitic target [2]. Much of the original morphological features have been eroded and very little of the allochthonous impactites remain. This has, however, allowed researchers to study the shock effects on the lower and central areas of the structure, as well as any subsequent hydrothermal activity. Previous work has focused on detailed classification of the target and autochthonous and allochthonous impactites [3, 4], identification of the projectile [5], and dating the structure using Ar-isotope techniques [2]. Authors have also noted geochemical evidence of K-metasomatism, which is pronounced throughout all lithologies as enrichment in K2O and depletion in CaO and Na2O [3, 4, 5]. This indicates a pervasive hydrothermal system, whose effects throughout the structure have yet to be studied in detail, particularly in those parts at and below the transient floor. The purpose of this study is to classify the mineralogical and geochemical effects of the hydrothermal system. Samples were collected via permission from the Réserve Naturelle de l'Astroblème de Rochechouart-Chassenon [6]. Sample selection was based on the presence of secondary mineralization in hand

  15. Capturing Near Earth Objects

    OpenAIRE

    Baoyin, Hexi; CHEN Yang; Li, Junfeng

    2011-01-01

    Recently, Near Earth Objects (NEOs) have been attracting great attention, and thousands of NEOs have been found to date. This paper examines the NEOs' orbital dynamics using the framework of an accurate solar system model and a Sun-Earth-NEO three-body system when the NEOs are close to Earth to search for NEOs with low-energy orbits. It is possible for such an NEO to be temporarily captured by Earth; its orbit would thereby be changed and it would become an Earth-orbiting object after a small...

  16. Effect of phytase supplementation on apparent phosphorus digestibility and phosphorus output in broiler chicks fed low-phosphorus diets

    Directory of Open Access Journals (Sweden)

    Xian-Ren Jiang

    2015-04-01

    Full Text Available This study was conducted to evaluate the effect of supplemental phytase in broiler chicks fed different low levels of total phosphorus (P on the apparent phosphorus digestibility (APD and phosphorus output (PO in the faeces and ileal digesta. After fed a standard broiler starter diet from day 0 to 14 post-hatch, a total of 144 male broiler chicks were allocated to 6 groups for a 7-d experiment with a 2 × 3 factorial design comparing phytase (supplemented without (CTR or with 400 FTU/kg phytase (PHY and total P levels (2.0, 2.5 and 3.0 g/kg. The faecal samples were collected from day 17 to 21 post-hatch. At 22 days of age, all the chicks were slaughtered and collected the ileal digesta. Phytase supplementation significantly (P < 0.01 increased APD and decreased PO in the faeces and ileal digesta in comparison with the CTR group. In addition, PO in the faeces expressed as g/kg DM diets and faeces (Diet × P level, P = 0.047 and < 0.01, respectively as well as PO in the ileal digesta expressed as g/kg DM digesta (Diet × P level, P = 0.04 were affected by diet and P level, which were due to the significant reduction (P < 0.01 by PHY supplementation to the diets with 3.0 g/kg total P. The results evidenced that supplemental phytase improved the APD and PO when chicks was fed 3.0 g/kg total P diet, while lower total P levels may limit exogenous phytase efficacy.

  17. Ethylene: a regulator of root architectural responses to soil phosphorus availability

    NARCIS (Netherlands)

    Borch, K.; Bouma, T.J.; Lynch, J.P.; Brown, K.M.

    1999-01-01

    The involvement of ethylene in root architectural responses to phosphorus availability was investigated in common bean (Phaseolus vulgaris L,) plants grown with sufficient and deficient phosphorus. Although phosphorus deficiency reduced root mass and lateral root number, main root length was

  18. Geochemistry and Fuid-Inclusion Microthermometry of the Farsesh Barite Deposit, Iran

    Directory of Open Access Journals (Sweden)

    Zarasvandi Alireza

    2014-10-01

    Full Text Available The Permian carbonate-hosted Farsesh barite deposit is located southeast of the City of Aligudarz in the province of Lorestan, Iran. Structurally, this deposit lies in the Zagros metallogenic belt and the Sanandaj-Sirjan Zone. Barite mineralisations occur as open-space flling veins, and as massive and replacement ores along fractures, faults and shear zones of the Permian carbonate host rocks. In order to determine the structure, in addition to pe-trographic and fuid-inclusions studies, an ICP-MS analysis was carried out in order to measure the major as well as the trace and rare earth elements. The Farsesh barite deposit has a simple mineralogy, of which barite is the main mineral, followed by calcite, dolomite, quartz, and opaque minerals such as Fe-oxides. Replacement of bar-ite by calcite is common and is more frequent than space-flling mineralisation. Sulphide minerals are minor and mainly consist of chalcopyrite and pyrite, which are altered by weathering to covellite, malachite and azurite. Petrographic analysis and micro-thermometry were carried out on the two-phase liquid/vapour inclusions in ellipsoidal or irregularly shaped minerals ranging in size from 5–10 µm. The measurements were conducted on fuid inclusions during the heating and subsequent homogenisation in the liquid phase. The low homogenisation temperatures (200–125°C and low to moderate salinity (4.2–20 eq wt% NaCl indicate that the barite had precipitated from hydrothermal basinal water with low to moderate salinity. It appears from the major and trace elements that geochemical features such as Ba and Sr enrichment in the barite samples was accompanied by depletion of Pb, Zn, Hg, Cu and Sb. The geochemistry of the rare earth elements, such as low σREE concentrations, LREE-enrichment chondrite-normalised REE patterns, the negative Ce and positive Eu anomalies, the low Ce/La ratio and the positive La and Gd anomalies, suggest that the Farsesh barite was deposited

  19. Petrology, Palynology, and Geochemistry of Gray Hawk Coal (Early Pennsylvanian, Langsettian in Eastern Kentucky, USA

    Directory of Open Access Journals (Sweden)

    James C. Hower

    2015-09-01

    Full Text Available This study presents recently collected data examining the organic petrology, palynology, mineralogy and geochemistry of the Gray Hawk coal bed. From the Early Pennsylvanian, Langsettian substage, Gray Hawk coal has been mined near the western edge of the eastern Kentucky portion of the Central Appalachian coalfield. While the coal is thin, rarely more than 0.5-m thick, it has a low-ash yield and a low-S content, making it an important local resource. The Gray Hawk coal palynology is dominated by Lycospora spp., and contains a diverse spectrum of small lycopods, tree ferns, small ferns, calamites, and gymnosperms. The maceral assemblages show an abundance of collotelinite, telinite, vitrodetrinite, fusinite, and semifusinite. Fecal pellet-derived macrinite, albeit with more compaction than is typically seen in younger coals, was observed in the Gray Hawk coal. The minerals in the coal are dominated by clay minerals (e.g., kaolinite, mixed-layer illite/smectite, illite, and to a lesser extent, pyrite, quartz, and iron III hydroxyl-sulfate, along with traces of chlorite, and in some cases, jarosite, szomolnokite, anatase, and calcite. The clay minerals are of authigenic and detrital origins. The occurrence of anatase as cell-fillings also indicates an authigenic origin. With the exception of Ge and As, which are slightly enriched in the coals, the concentrations of other trace elements are either close to or much lower than the averages for world hard coals. Arsenic and Hg are also enriched in the top bench of the coal and probably occur in pyrite. The elemental associations (e.g., Al2O3/TiO2, Cr/Th-Sc/Th indicate a sediment-source region with intermediate and felsic compositions. Rare metals, including Ga, rare earth elements and Ge, are highly enriched in the coal ashes, and the Gray Hawk coals have a great potential for industrial use of these metals. The rare earth elements in the samples are weakly fractionated or are characterized by heavy

  20. Geochemistry and mineralogy of the Late Permian coals from the Songzao Coalfield, Chongqing,southwestern China

    Institute of Scientific and Technical Information of China (English)

    DAI ShiFeng; ZHOU YiPing; REN DeYi; WANG XiBo; LI Dan; ZHAO Lei

    2007-01-01

    Mineralogy and geochemistry of the four main workable coal seams (No.6, No.7, No.8, and No.11) of Late Permian age from the Songzao Coalfield, Chongqing, Southwest China, were examined using inductively coupled plasma-mass spectrometry (ICP-MS), X-ray fluorescence spectrometry (XRF),cold-vapor absorption spectrometry (CV-AAS), ion-selective electrode (ISE), scanning electron microscopy equipped with an energy-dispersive X-ray spectrometer (SEM-EDX), and X-ray diffraction analysis (XRD). The results showed that the main workable No.8 Coal that accounts for about 60% of the total coal reserves in the Songzao Coalfield was not enriched in hazardous trace elements. The No.11 Coal has high concentrations of alkaline elements, Be (9.14 μg/g), SC (12.9 μg/g), Ti (9508 μg/g),Mn (397 μg/g), Co (23.7 μg/g), Cu (108 μg/g), Zn (123 μg/g), Ga (32 μg/g), Zr (1304 μg/g), Nb (169 μg/g), Hf (32.7 μg/g), Ta (11.4 μg/g), W (24.8 μg/g), Hg (0.28 μg/g), Pb (28.1 μg/g), Th (24.1 μg/g), and rare earth elements (509.62 μg/g). The concentration of Nb and Ta in the No. 11 Coal is higher than the industrial grade, and their potential utilization should be further studied. Besides pyrite, quartz, calcite, and clay minerals, trace minerals including chalcopyrite, marcasite, siderite, albite, mixed-layer clay minerals of illite and smectite, monazite, apatite, anatase, chlorite, and gypsum were found in the No.11 Coal. It should be noted that alabandite of hydrothermal origin and anatase occurring as cement were identified in coal. In addition, the clayey microbands derived from alkaline volcanic ashes were identified in the coal. The dominant compositions of these clayey microbands were mixed-layer clay minerals of illite and smectite, which were interlayered with organic bands. The modes of occurrence of alkaline volcanic ash bands indicate that the volcanic activities were characterized by the multiple eruptions,short time interval and small scale for each eruption during

  1. Geochemistry and mineralogy of the Late Permian coals from the Songzao Coalfield, Chongqing,southwestern China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Mineralogy and geochemistry of the four main workable coal seams (No.6, No.7, No.8, and No.11) of Late Permian age from the Songzao Coalfield, Chongqing, Southwest China, were examined using in- ductively coupled plasma-mass spectrometry (ICP-MS), X-ray fluorescence spectrometry (XRF), cold-vapor absorption spectrometry (CV-AAS), ion-selective electrode (ISE), scanning electron mi- croscopy equipped with an energy-dispersive X-ray spectrometer (SEM-EDX), and X-ray diffraction analysis (XRD). The results showed that the main workable No.8 Coal that accounts for about 60% of the total coal reserves in the Songzao Coalfield was not enriched in hazardous trace elements. The No.11 Coal has high concentrations of alkaline elements, Be (9.14 μg/g), Sc (12.9 μg/g), Ti (9508 μg/g), Mn (397 μg/g), Co (23.7 μg/g), Cu (108 μg/g), Zn (123 μg/g), Ga (32 μg/g), Zr (1304 μg/g), Nb (169 μg/g), Hf (32.7 μg/g), Ta (11.4 μg/g), W (24.8 μg/g), Hg (0.28 μg/g), Pb (28.1 μg/g), Th (24.1 μg/g), and rare earth elements (509.62 μg/g). The concentration of Nb and Ta in the No. 11 Coal is higher than the industrial grade, and their potential utilization should be further studied. Besides pyrite, quartz, calcite, and clay minerals, trace minerals including chalcopyrite, marcasite, siderite, albite, mixed-layer clay minerals of illite and smectite, monazite, apatite, anatase, chlorite, and gypsum were found in the No.11 Coal. It should be noted that alabandite of hydrothermal origin and anatase occurring as cement were identi- fied in coal. In addition, the clayey microbands derived from alkaline volcanic ashes were identified in the coal. The dominant compositions of these clayey microbands were mixed-layer clay minerals of illite and smectite, which were interlayered with organic bands. The modes of occurrence of alkaline volcanic ash bands indicate that the volcanic activities were characterized by the multiple eruptions, short time interval and small scale for each eruption

  2. Effect of mycorrhiza on growth criteria and phosphorus nutrition of lettuce (Lactuca sativa L. under different phosphorus application rates

    Directory of Open Access Journals (Sweden)

    S. Fatih Ergin

    2016-10-01

    Full Text Available In this study, effect of mycorrhiza on growth criteria and phosphorus nutrition of lettuce (Lactuca sativa L. under different phosphorus fertilization rates were investigated. Phosphorus were added into growing media as 0, 50, 100 and 200 mg P2O5/kg with and without mycorrhiza applications. Phosphorus applications significantly increased yield criteria of lettuce according to the control treatment statistically. Mycorrhiza application also significantly increased plant diameter, plant dry weight and phosphor uptake by plant. The highest phosphorus uptakes by plants were determined in 200 mg P2O5/kg treatments as 88.8 mg P/pot with mycorrhiza and 83.1 mg P/pot without mycorrhiza application. In the control at 0 doses of phosphorus with mycorrhiza treatment, phosphorus uptake (69.9 mg P/pot, edible weight (84.36 g, dry weight (8.64 g and leaf number (28 of lettuce were higher than that (47.7 mg P/pot, 59.33 g, 6.75 g and 20, respectively in the control without mycorrhiza application. It was determined that mycorrhiza had positive effect on growth criteria and phosphorus nutrition by lettuce plant, and this effect decreased at higher phosphorus application rates.

  3. Patient education for phosphorus management in chronic kidney disease

    Directory of Open Access Journals (Sweden)

    Kalantar-Zadeh K

    2013-05-01

    Full Text Available Kamyar Kalantar-ZadehHarold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, University of California Irvine’s School of Medicine, Irvine, CA, USAObjectives: This review explores the challenges and solutions in educating patients with chronic kidney disease (CKD to lower serum phosphorus while avoiding protein insufficiency and hypercalcemia.Methods: A literature search including terms “hyperphosphatemia,” “patient education,” “food fatigue,” “hypercalcemia,” and “phosphorus–protein ratio” was undertaken using PubMed.Results: Hyperphosphatemia is a strong predictor of mortality in advanced CKD and is remediated via diet, phosphorus binders, and dialysis. Dietary counseling should encourage the consumption of foods with the least amount of inorganic or absorbable phosphorus, low phosphorus-to-protein ratios, and adequate protein content, and discourage excessive calcium intake in high-risk patients. Emerging educational initiatives include food labeling using a “traffic light” scheme, motivational interviewing techniques, and the Phosphate Education Program – whereby patients no longer have to memorize the phosphorus content of each individual food component, but only a “phosphorus unit” value for a limited number of food groups. Phosphorus binders are associated with a clear survival advantage in CKD patients, overcome the limitations associated with dietary phosphorus restriction, and permit a more flexible approach to achieving normalization of phosphorus levels.Conclusion: Patient education on phosphorus and calcium management can improve concordance and adherence and empower patients to collaborate actively for optimal control of mineral metabolism.Keywords: hyperphosphatemia, renal diet, phosphorus binders, educational programs, food fatigue, concordance

  4. Digestible phosphorus levels for barrows from 50 to 80 kg

    Directory of Open Access Journals (Sweden)

    Viviane Maria Oliveira dos Santos Nieto

    2016-05-01

    Full Text Available ABSTRACT This study was carried out to evaluate the levels of digestible phosphorus in diets for barrows with a high potential for lean meat deposition from 50 to 80 kg. Eighty barrows, with an initial weight of 47.93±3.43 kg, were distributed in completely randomized blocks, with each group given five levels of digestible phosphorus (1.86, 2.23, 2.61, 2.99, and 3.36 g kg−1. There were eight replicates, and two animals per experimental unit. Phosphorus levels did not significantly influence feed intake, weight gain, or feed conversion ratio. Daily digestible phosphorus intake increased linearly as levels of phosphorus in the diet were increased. Phosphorus levels did not significantly influence muscle depth, loin eye area, backfat thickness, or the percentage and quantity of lean meat in the carcass. A linear increase was observed for feeding cost as the levels of digestible phosphorus in the diet were increased, and the level of 1.86 g kg−1 cost 29.4% less when compared with the level of 2.61 g kg−1. The dry matter, natural matter, the coefficient of the residue, and volatile solids of the waste were not significantly influenced by phosphorus levels. Conversely, it was possible to observe an increasing linear effect for total solids, total phosphorus, and total nitrogen in the waste of animals receiving diets with increased levels of digestible phosphorus. The level of 1.86 g kg−1, which corresponded to a daily intake of 4.77 g−1 of digestible phosphorus, meets the requirements of barrows weighing 50 to 80 kg.

  5. Calcium effect on the metabolic pathway of phosphorus accumulating organisms in enhanced biological phosphorus removal systems.

    Science.gov (United States)

    Zhang, Hai-Ling; Sheng, Guo-Ping; Fang, Wei; Wang, Yong-Peng; Fang, Cai-Yun; Shao, Li-Min; Yu, Han-Qing

    2015-11-01

    Phosphorus accumulating organisms (PAOs) have been found to act as glycogen-accumulating organisms (GAOs) under certain conditions, thus, the deterioration in the performance of enhanced biological phosphorus removal systems is not always attributed to the proliferation of GAOs. In this work, the effects of calcium on the metabolic pathway of PAOs were explored. It was found that when the influent Ca(2+) concentration was elevated, the tendency and extent of extracellular calcium phosphate precipitation increased, and the intracellular inert Ca-bound polyphosphate was synthesized, while the microbial population remained almost unchanged. The changes in the ratios of phosphorus released/acetate uptaken, the glycogen degraded/acetate uptaken and the poly-β-hydroxyalkanoates synthesized/acetate uptaken during the anaerobic period confirm that, as the influent Ca(2+) concentration was increased, the polyphosphate-accumulating metabolism was partially shifted to the glycogen-accumulating metabolism. At an influent Ca(2+) around 50 mg/L, in addition to the extracellular calcium phosphate precipitation, the intracellular inert Ca-bound polyphosphate synthesis might also be involved in the metabolic change of PAOs. The results of the present work would be beneficial to better understand the biochemical metabolism of PAOs in enhanced biological phosphorus removal systems. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Effects of phosphorus-deficient diets on the carbon and phosphorus balance of Daphnia magna

    NARCIS (Netherlands)

    DeMott, W.R.; Gulati, R.D.; Siewertsen, K.

    1998-01-01

    We used laboratory growth and feeding experiments to study the balance of carbon (C) and phosphorus (P) in Daphnia magna. Daphnia were fed high-concentration mixtures of P-sufficient and P-deficient green algae (Scenedesmus acutus; molar C:P 80 and 900, respectively) or mixtures of P-deficient

  7. Evaluation of a quantitative phosphorus transport model for potential improvement of southern phosphorus indices

    Science.gov (United States)

    Due to a shortage of available phosphorus (P) loss data sets, simulated data from a quantitative P transport model could be used to evaluate a P-index. However, the model would need to accurately predict the P loss data sets that are available. The objective of this study was to compare predictions ...

  8. Selection of phosphorus solubilizing bacteria with biocontrol potential for growth in phosphorus rich animal bone charcoal

    NARCIS (Netherlands)

    Postma, J.; Nijhuis, E.H.; Sommeus, E.

    2010-01-01

    Bacteria with the ability to solubilize phosphorus (P) and to improve plant health were selected and tested for growth and survival in P-rich animal bone charcoal (ABC). ABC is suggested to be suitable as a carrier for biocontrol agents, offering them a protected niche as well as delivering phosphat

  9. Urban phosphorus sustainability: Systemically incorporating social, ecological, and technological factors into phosphorus flow analysis

    Science.gov (United States)

    Genevieve S. Metson; David M. Iwaniec; Lawrence A. Baker; Elena M. Bennett; Daniel L. Childers; Dana Cordell; Nancy B. Grimm; J. Morgan Grove; Daniel A. Nidzgorski; Stuart. White

    2015-01-01

    Phosphorus (P) is an essential fertilizer for agricultural production but is also a potent aquatic pollutant. Current P management fails to adequately address both the issue of food security due to P scarcity and P pollution threats to water bodies. As centers of food consumption and waste production, cities transport and store much P and thus provide important...

  10. Earth Sciences Division Research Summaries 2002-2003

    Energy Technology Data Exchange (ETDEWEB)

    Bodvarsson, G.S.

    2003-11-01

    Research in earth and atmospheric sciences is becoming increasingly important in light of the energy, climate change, and environmental issues facing the United States and the world. The development of new energy resources other than hydrocarbons and the safe disposal of nuclear waste and greenhouse gases (such as carbon dioxide and methane) are critical to the future energy needs and environmental safety of this planet. In addition, the cleanup of many contaminated sites in the U.S., along with the preservation and management of our water supply, remain key challenges for us as well as future generations. Addressing these energy, climate change, and environmental issues requires the timely integration of earth sciences' disciplines (such as geology, hydrology, oceanography, climatology, geophysics, geochemistry, geomechanics, ecology, and environmental sciences). This integration will involve focusing on fundamental crosscutting concerns that are common to many of these issues. A primary focus will be the characterization, imaging, and manipulation of fluids in the earth. Such capabilities are critical to many DOE applications, from environmental restoration to energy extraction and optimization. The Earth Sciences Division (ESD) of the Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley Lab) is currently addressing many of the key technical issues described above. In this document, we present summaries of many of our current research projects. While it is not a complete accounting, it is representative of the nature and breadth of our research effort. We are proud of our scientific efforts, and we hope that you will find our research useful and exciting. Any comments on our research are appreciated and can be sent to me personally. This report is divided into five sections that correspond to the major research programs in the Earth Sciences Division: (1) Fundamental and Exploratory Research; (2) Nuclear Waste; (3) Energy Resources; (4

  11. Stewardship to tackle global phosphorus inefficiency

    DEFF Research Database (Denmark)

    Withers, Paul J. A.; Dijk, Kimo van; Neset, Tina-Simone

    2015-01-01

    The inefficient use of phosphorus (P) in the food chain is a threat to the global aquatic environment and the health and well-being of citizens, and it is depleting an essential finite natural resource critical for future food security and ecosystem function. We outline a strategic framework of 5R...... imports. Their combined adoption facilitated by interactive policies, co-operation between upstream and downstream stakeholders (researchers, investors, producers, distributors, and consumers), and more harmonized approaches to P accounting would maximize the resource and environmental benefits and help...... deliver a more competitive, circular, and sustainable European economy. The case of Europe provides a blueprint for global P stewardship....

  12. Biological elimination phosphorus; Eliminacion biologia de fosforo

    Energy Technology Data Exchange (ETDEWEB)

    Carrera, J.; Vicent, T.; Lafuente, J. [Universitat Autonoma de Barcelona (Spain)

    2000-07-01

    Phosphorus is the main limiting nutrient in the eutrophication process, and therefore its removal from the aquatic medium is indispensable. Biological Phosphorous Removal is a more efficient and convenient process compared with the classical chemical precipitation, due to a reduction of chemical reagents and sludge production. Moreover, it represents energy save since the sludge produced can be reused for agriculture purposes. In this paper bibliographic hypothesis about the metabolic pathways of the phosphorous accumulating organisms are widely and accurate reviewed and the above mentioned environmental benefits of the Biological Phosphorous Removal are reported. (Author) 22 refs.

  13. Determination of soil organic phosphorus exchange sensitivity

    Science.gov (United States)

    Shand, Charles; Wendler, Renate; Lumsdon, David; Cooper, Pat; George, Timothy; Brown, Lawrie; Giles, Courtney; Stutter, Marc; Menezes-Blackburn, Daniel; Zhang, Hao; Wearing, Catherine; Haygarth, Philip; Blackwell, Martin; Darch, Tegan

    2015-04-01

    Soils contain both organic and inorganic phosphorus (P) species in varying proportions. Studies have shown that many soils contain substantial amounts of inositol hexaphosphate (IHP) and there is much interest worldwide in developing strategies to make some use of this recalcitrant resource for plant growth to reduce P fertilizer inputs. Little is known about the preference of ion exchange processes in the solubilisation of organic vs inorganic P forms in soils, an important first step in making P forms bioavailable. Although they do not possess biotic functions, resins provides a simple means to deplete P forms in soil allowing investigation of exchange selectivity between inorganic and organic P forms. The aim of our work was to determine new understanding of exchange selectivity in soils and provide insight into potential depletion and plant uptake of soil phosphorus, with emphasis on organic forms such as IHP. For our study we used a Cambisol sampled from an agricultural area (Tayport) near Dundee in Scotland. The soil had a high Olsen (0.5 M sodium bicarbonate at pH 8.5) extractable P status (84 mg P/kg) and P-31 nuclear magnetic resonance analysis of its NaOH/EDTA extract showed it contained a substantial proportion of IHP (21 % of total extractable P). For resin extraction we used anion exchange resin sheets (4.17 cm each side) in bicarbonate form to minimise pH related solubilisation effects. We used 3.5 g of soil in 75 ml of water and added 1, 2 or 3 resin squares. After equilibration the resin squares were removed and replaced with fresh resin squares a further 3 times. Phosphorus was recovered from the resin sheets by elution with 0.25 M sulphuric acid and analysed by inductively coupled plasma spectroscopy to determine total P, and colorimetrically with malachite green to determine inorganic P with the remainder assigned to organic P. The data showed that the resin preferentially removed inorganic P and even after four sequential extractions little or

  14. Enhanced biological phosphorus removal employing EDTA disodium

    Energy Technology Data Exchange (ETDEWEB)

    Bojinova, D.; Velkova, R. [Higher Inst. of Chemical Technology, Sofia (Bulgaria)

    1996-12-31

    The biological phosphorus removal is a promising alternative to the conventional chemical technologies for processing of phosphate raw materials. The object of this study was the effect of EDTA disodium on the biotreatment of tunisian phosphorite with the strain of Aspergillus niger. The incubation was carried out in two nutritive mediums, with different phosphate content. The experimental results showed that the additives of EDTA disodium in the nutritive medium increased the rate of extraction of P{sub 2}O{sub 5} and shortened significantly the time for biological leaching. 5 refs., 3 figs., 2 tabs.

  15. Elastic properties of suspended black phosphorus nanosheets

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jia-Ying; Li, Yang; Zhen, Liang; Xu, Cheng-Yan, E-mail: cy-xu@hit.edu.cn [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); MOE Key Laboratory of Micro-systems and Micro-structures Manufacturing, Harbin Institute of Technology, Harbin 150080 (China); Zhan, Zhao-Yao [Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714 (China); Li, Tie [Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China)

    2016-01-04

    The mechanical properties of black phosphorus (BP) nanosheets suspended over circular holes were measured by an atomic force microscope nanoindentation method. The continuum mechanic model was introduced to calculate the elastic modulus and pretension of BP nanosheets with thicknesses ranging from 14.3 to 34 nm. Elastic modulus of BP nanosheets declines with thickness, and the maximum value is 276 ± 32.4 GPa. Besides, the effective strain of BP ranges from 8 to 17% with a breaking strength of 25 GPa. Our results show that BP nanosheets serve as a promising candidate for flexible electronic applications.

  16. Core Forensics: Earth's Accretion and Differentiation

    Science.gov (United States)

    Badro, J.; Brodholt, J. P.; Siebert, J.; Piet, H.; Ryerson, F. J.

    2013-12-01

    Earth's accretion and its primitive differentiation are intimately interlinked processes. One way to constrain accretionary processes is by looking at the major differentiation event that took place during accretion: core formation. Understanding core formation and core composition can certainly shed a new light on early and late accretionary processes. On the other hand, testing certain accretionary models and hypothesis (fluxes, chemistries, timing) allows -short of validating them- at the very least to unambiguously refute them, through the 'filter'' of core formation and composition. Earth's core formed during accretion as a result of melting, phase-separation, and segregation of accretionary building blocks (from meteorites to planetesimals). The bulk composition of the core and mantle depends on the evolution (pressure, temperature, composition) of core extraction during accretion. The entire process left a compositional imprint on both reservoirs: (1) in the silicate Earth, in terms of siderophile trace-element (Ni, Co, V, Cr, among others) concentrations and isotopic fractionation (Si, Cu, among others), a record that is observed in present-day mantle rocks; and (2) on the core, in terms of major element composition and light elements dissolved in the metal, a record that is observed by seismology through the core density-deficit. This imprint constitutes actually a fairly impressive set of evidence (siderophile element concentration and fractionation, volatile and siderophile element isotopic fractionation), can be used today to trace back the primordial processes that occurred 4.5 billion years ago. We are seeking to provide an overhaul of the standard core formation/composition models, by using a new rationale that bridges geophysics and geochemistry. The new ingredients are (1) new laser-heated diamond anvil cell partitioning data, dramatically extending the previous P-T conditions for experimental work, (2) ab initio molecular dynamics calculations to

  17. Potential impact of dietary choices on phosphorus recycling and global phosphorus footprints: the case of the average Australian city

    Directory of Open Access Journals (Sweden)

    Genevieve Metson

    2016-08-01

    Full Text Available Changes in human diets, population increase, changes in farming practices, and globalized food chains have led to dramatic increases in the demand for phosphorus fertilizers. Long-term food security and water quality are however threatened by such increased phosphorus consumption because the world’s main source, phosphate rock, is an increasingly scarce resource. At the same time losses of phosphorus from farms and cities have caused widespread water pollution. As one of the major factors contributing to increased phosphorus demand, dietary choices can play a key role in changing our resource consumption pathway. Importantly, the effects of dietary choices on phosphorus management are two-fold: First, dietary choices affects a person or region’s ‘phosphorus footprint’ – the magnitude of mined phosphate required to meet food demand. Second, dietary choices affect the magnitude of phosphorus content in human excreta, and hence the recycling- and pollution-potential of phosphorus in sanitation systems. When considering options and impacts of interventions at the city scale (e.g. potential for recycling, dietary changes may be undervalued as a solution towards phosphorus sustainability. In an average Australian city for example, a vegetable-based diet could marginally increase phosphorus in human excreta (8% increase. However such a shift could simultaneously dramatically decrease the mined phosphate required to meet the city resident’s annual food demand by 72%. Taking a multi-scalar perspective is therefore key to fully exploring dietary choices as one of the tools for sustainable phosphorus management.

  18. Phosphorus as a limiting factor on sustainable greywater irrigation.

    Science.gov (United States)

    Turner, Ryan D R; Will, Geoffrey D; Dawes, Les A; Gardner, Edward A; Lyons, David J

    2013-07-01

    Water reuse through greywater irrigation has been adopted worldwide and has been proposed as a potential sustainable solution to increased water demands. Despite widespread adoption, there is limited domestic knowledge of greywater reuse. There is no pressure to produce low-level phosphorus products and current guidelines and legislation, such as those in Australia, may be inadequate due to the lack of long-term data to provide a sound scientific basis. Research has clearly identified phosphorus as a potential environmental risk to waterways from many forms of irrigation. To assess the sustainability of greywater irrigation, this study compared four residential lots that had been irrigated with greywater for four years and adjacent non-irrigated lots that acted as controls. Each lot was monitored for the volume of greywater applied and selected physic-chemical water quality parameters and soil chemistry profiles were analysed. The non-irrigated soil profiles showed low levels of phosphorus and were used as controls. The Mechlich3 Phosphorus ratio (M3PSR) and Phosphate Environmental Risk Index (PERI) were used to determine the environmental risk of phosphorus leaching from the irrigated soils. Soil phosphorus concentrations were compared to theoretical greywater irrigation loadings. The measured phosphorus soil concentrations and the estimated greywater loadings were of similar magnitude. Sustainable greywater reuse is possible; however incorrect use and/or lack of understanding of how household products affect greywater can result in phosphorus posing a significant risk to the environment.

  19. Biological phosphorus uptake under anoxic and aerobic conditions

    DEFF Research Database (Denmark)

    Kerrn-Jespersen, Jens Peter; Henze, Mogens

    1993-01-01

    Biological phosphorus removal was investigated under anoxic and aerobic conditions. Tests were made to establish whether phosphorus accumulating bacteria can take up phosphate under anoxic conditions and thus utilise nitrate as oxidant. Furthermore, it was tested how the amount of organic matter...

  20. Effects of phosphorus nutrition on tiller emergence in wheat

    NARCIS (Netherlands)

    Rodríguez, D.; Andrade, F.H.; Goudriaan, J.

    1999-01-01

    Phosphorus (P) deficiency limits the yield of wheat, particularly by reducing the number of ears per unit of area because of a poor tiller emergence. The objectives of this work were to (i) determine whether tiller emergence under low phosphorus availability is a function of the availability of assi

  1. Modeling biogeochemical processes of phosphorus for global food supply.

    Science.gov (United States)

    Dumas, Marion; Frossard, Emmanuel; Scholz, Roland W

    2011-08-01

    Harvests of crops, their trade and consumption, soil erosion, fertilization and recycling of organic waste generate fluxes of phosphorus in and out of the soil that continuously change the worldwide spatial distribution of total phosphorus in arable soils. Furthermore, due to variability in the properties of the virgin soils and the different histories of agricultural practices, on a planetary scale, the distribution of total soil phosphorus is very heterogeneous. There are two key relationships that determine how this distribution and its change over time affect crop yields. One is the relationship between total soil phosphorus and bioavailable soil phosphorus and the second is the relationship between bioavailable soil phosphorus and yields. Both of these depend on environmental variables such as soil properties and climate. We propose a model in which these relationships are described probabilistically and integrated with the dynamic feedbacks of P cycling in the human ecosystem. The model we propose is a first step towards evaluating the large-scale effects of different nutrient management scenarios. One application of particular interest is to evaluate the vulnerability of different regions to an increased scarcity in P mineral fertilizers. Another is to evaluate different regions' deficiency in total soil phosphorus compared with the level at which they could sustain their maximum potential yield without external mineral inputs of phosphorus but solely by recycling organic matter to close the nutrient cycle.

  2. The release of dissolved phosphorus from lake sediments.

    NARCIS (Netherlands)

    Boers, P.C.M.

    1991-01-01

    Chapter 1. Introduction: Eutrophication is one of the world's major water quality problems. Attempts to alleviate eutrophication of lakes have involved the control of phosphorus loadings. In such cases, an internal loading of phosphorus from the sediments may retard an improvement o

  3. Low Phytic Acid Barley Responses to Phosphorus Rates

    Science.gov (United States)

    Low phytic acid (LPA) barley (Hordeum vulgare L.) cultivars partition phosphorus in seed tissue differently than conventional barley cultivars through a reduction in seed phytic acid (myo-inositol-1,2,3,4,5,6-hexkisphosphate) coupled with an increase in inorganic phosphorus. The response of the LPA...

  4. Effect of sulphide on enhanced biological phosphorus removal

    NARCIS (Netherlands)

    Rubio Rincon, F.J.

    2017-01-01

    The enhanced biological removal of phosphorus (EBPR) is a popular process due to high removal efficiency, low operational costs, and the possibility of phosphorus recovery. Nevertheless, the stability of the EBPR depends on different factors such as: temperature, pH, and the presence of toxic

  5. Approaches and Challenges to Engineering Seed Phytate and Total Phosphorus

    Science.gov (United States)

    About 75% of seed total phosphorus (P) is found in a single compound, phytic acid (myo-inositol-1,2,3,4,5,6-hexakisphosphate or InsP6). Phytic acid is not efficiently utilized by monogastric animals (poultry, swine, fish), which creates phosphorus management and environmental impact problems in anim...

  6. Plant based phosphorus recovery from wastewater via algae and macrophytes.

    Science.gov (United States)

    Shilton, Andrew N; Powell, Nicola; Guieysse, Benoit

    2012-12-01

    At present, resource recovery by irrigation of wastewater to plants is usually driven by the value of the water resource rather than phosphorus recovery. Expanded irrigation for increased phosphorus recovery may be expected as the scarcity and price of phosphorus increases, but providing the necessary treatment, storage and conveyance comes at significant expense. An alternative to taking the wastewater to the plants is instead to take the plants to the wastewater. Algal ponds and macrophyte wetlands are already in widespread use for wastewater treatment and if harvested, would require less than one-tenth of the area to recover phosphorus compared to terrestrial crops/pastures. This area could be further decreased if the phosphorus content of the macrophytes and algae biomass was tripled from 1% to 3% via luxury uptake. While this and many other opportunities for plant based recovery of phosphorus exist, e.g. offshore cultivation, much of this technology development is still in its infancy. Research that enhances our understanding of how to maximise phosphorus uptake and harvest yields; and further add value to the biomass for reuse would see the recovery of phosphorus via plants become an important solution in the future.

  7. Dietary phosphorus is associated with greater left ventricular mass.

    Science.gov (United States)

    Yamamoto, Kalani T; Robinson-Cohen, Cassianne; de Oliveira, Marcia C; Kostina, Alina; Nettleton, Jennifer A; Ix, Joachim H; Nguyen, Ha; Eng, John; Lima, Joao A C; Siscovick, David S; Weiss, Noel S; Kestenbaum, Bryan

    2013-04-01

    Dietary phosphorus consumption has risen steadily in the United States. Oral phosphorus loading alters key regulatory hormones and impairs vascular endothelial function, which may lead to an increase in left ventricular mass (LVM). We investigated the association of dietary phosphorus with LVM in 4494 participants from the Multi-Ethnic Study of Atherosclerosis, a community-based study of individuals who were free of known cardiovascular disease. The intake of dietary phosphorus was estimated using a 120-item food frequency questionnaire and the LVM was measured using magnetic resonance imaging. Regression models were used to determine associations of estimated dietary phosphorus with LVM and left ventricular hypertrophy (LVH). Mean estimated dietary phosphorus intake was 1167 mg/day in men and 1017 mg/day in women. After adjustment for demographics, dietary sodium, total calories, lifestyle factors, comorbidities, and established LVH risk factors, each quintile increase in the estimated dietary phosphate intake was associated with an estimated 1.1 g greater LVM. The highest gender-specific dietary phosphorus quintile was associated with an estimated 6.1 g greater LVM compared with the lowest quintile. Higher dietary phosphorus intake was associated with greater odds of LVH among women, but not men. These associations require confirmation in other studies.

  8. Ups and Downs of the Yellow Phosphorus Market in 2007

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ 1 Surplus capacity The rapid growth of the economy in China promoted drastic development of the yellow phosphorus sector from 1985 to 2004. The capacity of yellow phosphorus expanded rapidly from 100 000 t/a in 1985 to 1.2 million t/a in 2004 with an average annual growth of around 14.0%.

  9. Biological Phosphorus Removal in a Moving Bed Biofilm Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Helness, Herman

    2007-09-15

    The scope of this study was to investigate use of the moving bed biofilm reactor (MBBR) process for biological phosphorus removal. The goal has been to describe the operating conditions required for biological phosphorus and nitrogen removal in a MBBR operated as a sequencing batch reactor (SBR), and determine dimensioning criteria for such a process

  10. Seeking evidence of multidisciplinarity in environmental geochemistry and health: an analysis of arsenic in drinking water research.

    Science.gov (United States)

    Aderibigbe, Abiodun D; Stewart, Alex G; Hursthouse, Andrew S

    2017-02-24

    A multidisciplinary approach to research affords the opportunity of objectivity, creation of new knowledge and potentially a more generally acceptable solution to problems that informed the research in the first place. It increasingly features in national programmes supporting basic and applied research, but for over 40 years, has been the arena for many research teams in environmental geochemistry and health. This study explores the nature of multidisciplinary research in the earth and health sciences using a sample selected from co-authored articles reporting research on arsenic (As) in drinking water from 1979 to 2013. A total of 889 relevant articles were sourced using the online version of the science citation index-expanded (SCI-expanded). The articles were classified according to author affiliation and later by author discipline/research interests using the Revised Field of Science and Technology Frascati manual DSTI/EAS/STP/NESTI (2006) 19/FINAL and a decision algorithm. Few articles were published on the topic until 2000. More articles were published across all affiliations in the last 10 years of the review period (2004-2013) than in the first 10 years (1979-1988). Only 84 (~9%) articles fell within the "earth and health" only and "earth, health and other" categories when classification was undertaken by author affiliation alone. This suggests that level of collaboration between earth and health scientists in arsenic in drinking water research may be very low. By refining the classification further using author discipline/research interests, only 28 of the 84 articles appear to be co-authored by earth and health scientists alongside professionals in other fields. More than half of these 28 articles involved descriptive non-experimental, observational study designs, limited in direct causal hypotheses and mechanistic investigation. If collaborative research is to lead to the increased multidisciplinary research, early interaction should be encouraged

  11. Age, geochemistry and melt flux variations for the Hawaiian Ridge

    Science.gov (United States)

    Garcia, M. O.; Weis, D. A.; Greene, A. R.; Wessel, P.; Harrison, L.; Tree, J.

    2012-12-01

    The Hawaiian Ridge portion of the Hawaiian-Emperor Chain, the classic example of a mantle plume produced linear island chain, is 6000 km in length, active for 80+ Myr, and tectonically simple. Despite its importance to our understanding of mantle plumes and Cenozoic plate motion, there are large data gaps for the age and geochemistry of lavas from volcanoes along the Hawaiian Ridge (HR) portion of the Chain. Ages: Only volcanoes near the Hawaiian-Emperor bend and in the Hawaiian Islands have modern Ar-Ar ages, leaving a gap of 2000 km where existing K-Ar ages suggest synchronous volcanism over a 1000 km section. Geochemistry: There is a 2900 km gap in high precision geochemical data for the HR. The Emperor Seamounts (>45 Ma) have better regional coverage of recent isotopic data and show a correlation of Sr isotope composition with age of the underlying oceanic lithosphere (Regelous et al. 2003). The HR has an unexplained, exponential increase in magma flux over the last 30 Myr (Vidal & Bonneville 2004). Potential explanations for the increase in magma flux include: changes in melting conditions (temperature and/or pressure), change in source fertility related to rock type (pyroxenite vs. peridotite) or previous melting history, and/or changes in plate stresses resulting from reconfigurations of plate motion. Our new multi-disciplinary project will: 1) Determine 40Ar/39Ar ages, and whole-rock major, trace element, and Pb, Sr, Nd and Hf isotopic geochemistry for lavas from 20 volcanoes spanning ~2150 km of the HR (NW of the Hawaiian Islands). 2) Use the geochemical data to determine the long-term evolution of the Hawaiian mantle plume source components and to evaluate whether there have been systematic variations in mantle potential temperature, melting pressure, and/or source lithology during the creation of the HR. If so, are they responsible for the 300% variation in melt production along the Ridge? Also, we will assess when the more fertile Loa source component

  12. Raman Sensitive Degradation and Etching Dynamics of Exfoliated Black Phosphorus

    Science.gov (United States)

    Alsaffar, Fadhel; Alodan, Sarah; Alrasheed, Abdul; Alhussain, Abdulrahman; Alrubaiq, Noura; Abbas, Ahmad; Amer, Moh. R.

    2017-01-01

    Layered black phosphorus has drawn much attention due to the existence of a band gap compared to the widely known graphene. However, environmental stability of black phosphorus is still a major issue, which hinders the realization of practical device applications. Here, we spatially Raman map exfoliated black phosphorus using confocal fast-scanning technique at different time intervals. We observe a Raman intensity modulation for , B2g, and modes. This Raman modulation is found to be caused by optical interference, which gives insights into the oxidation mechanism. Finally, we examine the fabrication compatible PMMA coating as a viable passivation layer. Our measurements indicate that PMMA passivated black phosphorus thin film flakes can stay pristine for a period of 19 days when left in a dark environment, allowing sufficient time for further nanofabrication processing. Our results shed light on black phosphorus degradation which can aid future passivation methods. PMID:28317834

  13. Soil phosphorus and the ecology of lowland tropical forests

    Science.gov (United States)

    Turner, Ben

    2016-04-01

    In this presentation I will explore the extent to which phosphorus influences the productivity, diversity, and distribution of plant species in tropical forests. I will highlight the range of soils that occur in tropical forests and will argue that pedogenesis and associated phosphorus depletion is a primary driver of forest diversity over long timescales. I will draw on data from a regional-scale network of forest dynamics plots in Panama to show that tree species distributions are determined predominantly as a function of dry season intensity and soil phosphorus availability, and will suggest potential mechanistic explanations for this pattern in relation to phosphorus acquisition. Finally, I will present observational and experimental evidence from Panama to show how phosphorus, nitrogen, and potassium, limit plant productivity and microbial communities on strongly-weathered soils in the lowland tropics.

  14. Microbial contributions to phosphorus cycling in eutrophic lakes and wastewater.

    Science.gov (United States)

    McMahon, Katherine D; Read, Emily K

    2013-01-01

    Phosphorus is a key element controlling the productivity of freshwater ecosystems, and microbes drive most of its relevant biogeochemistry. Eutrophic lakes are generally dominated by cyanobacteria that compete fiercely with algae and heterotrophs for the element. In wastewater treatment, engineers select for specialized bacteria capable of sequestering phosphorus from the water, to protect surface waters from further loading. The intracellular storage molecule polyphosphate plays an important role in both systems, allowing key taxa to control phosphorus availability. The importance of dissolved organic phosphorus in eutrophic lakes and mineralization mechanisms is still underappreciated and understudied. The need for functional redundancy through biological diversity in wastewater treatment plants is also clear. In both systems, a holistic ecosystems biology approach is needed to understand the molecular mechanisms controlling phosphorus metabolism and the ecological interactions and factors controlling ecosystem-level process rates.

  15. Black Phosphorus: Critical Review and Potential for Water Splitting Photocatalyst

    Directory of Open Access Journals (Sweden)

    Tae Hyung Lee

    2016-10-01

    Full Text Available A century after its first synthesis in 1914, black phosphorus has been attracting significant attention as a promising two-dimensional material in recent years due to its unique properties. Nowadays, with the development of its exfoliation method, there are extensive applications of black phosphorus in transistors, batteries and optoelectronics. Though, because of its hardship in mass production and stability problems, the potential of the black phosphorus in various fields is left unexplored. Here, we provide a comprehensive review of crystal structure, electronic, optical properties and synthesis of black phosphorus. Recent research works about the applications of black phosphorus is summarized. Among them, the possibility of black phosphorous as a solar water splitting photocatalyst is mainly discussed and the feasible novel structure of photocatalysts based on black phosphorous is proposed.

  16. Phosphorus isothermal adsorption characteristics of mulch of bioretention

    Directory of Open Access Journals (Sweden)

    Mei Ying

    2012-01-01

    Full Text Available This study aims to identify mulch of bioretention which has high phosphorus sorption capacity. The phosphorus adsorption characteristics of five types of mulch of bioretention are studied by three isothermal adsorption experiments. Results show that the Langmuir eqution is suitable for describing absorption characteristics of five types of mulch. The positive values of Gibbs free energy for phosphorus indicate that the phosphorus biosorption by five mulches is a non-spontaneous process, and the values of mean sorption free energy of mulch are less than 8 kJ/mol, which proves that the adsorption process can be dominated by physical forces. The vermiculite is the better mulch of bioretention based on high phosphorus removal capacity.

  17. The Earth's Magnetic Field

    OpenAIRE

    Edda Lína Gunnarsdóttir 1988

    2012-01-01

    The Earth's magnetic field is essential for life on Earth, as we know it, to exist. It forms a magnetic shield around the planet, protecting it from high energy particles and radiation from the Sun, which can cause damage to life, power systems, orbiting satellites, astronauts and spacecrafts. This report contains a general overview of the Earth's magnetic field. The different sources that contribute to the total magnetic field are presented and the diverse variations in the field are describ...

  18. Uderstanding Snowball Earth Deglaciation

    Science.gov (United States)

    Abbot, D. S.

    2012-12-01

    Earth, a normally clement planet comfortably in its star's habitable zone, suffered global or nearly global glaciation at least twice during the Neoproterozoic era (at about 635 and 710 million years ago). Viewed in the context of planetary evolution, these pan-global glaciations (Snowball Earth events) were extremely rapid, lasting only a few million years. The dramatic effect of the Snowball Earth events on the development of the planet can be seen through their link to rises in atmospheric oxygen and evolutionary innovations. These potential catastrophes on an otherwise clement planet can be used to gain insight into planetary habitability more generally. Since Earth is not currently a Snowball, a sound deglaciation mechanism is crucial for the viability of the Snowball Earth hypothesis. The traditional deglaciation mechanism is a massive build up of CO2 due to reduced weathering during Snowball Earth events until tropical surface temperatures reach the melting point. Once initiated, such a deglaciation might happen on a timescale of only dozens of thousands of years and would thrust Earth from the coldest climate in its history to the warmest. Therefore embedded in Snowball Earth events is an even more rapid and dramatic environmental change. Early global climate model simulations raised doubt about whether Snowball Earth deglaciation could be achieved at a CO2 concentration low enough to be consistent with geochemical data, which represented a potential challenge to the Snowball Earth hypothesis. Over the past few years dust and clouds have emerged as the essential missing additional processes that would allow Snowball Earth deglaciation at a low enough CO2 concentration. I will discuss the dust and cloud mechanisms and the modeling behind these ideas. This effort is critical for the broader implications of Snowball Earth events because understanding the specific deglaciation mechanism determines whether similar processes could happen on other planets.

  19. Ruzigrass affecting soil-phosphorus availability

    Directory of Open Access Journals (Sweden)

    Alexandre Merlin

    2013-12-01

    Full Text Available The objective of this work was to evaluate the effectiveness of ruzigrass (Urochloaruziziensis in enhancing soil-P availability in areas fertilized with soluble or reactive rock phosphates. The area had been cropped for five years under no-till, in a system involving soybean, triticale/black-oat, and pearl millet. Previously to the five-year cultivation period, corrective phosphorus fertilization was applied once on soil surface, at 0.0 and 80 kg ha-1 P2O5, as triple superphosphate or Arad rock phosphate. After this five-year period, plots received the same corrective P fertilization as before and ruzigrass was introduced to the cropping system in the stead of the other cover crops. Soil samples were taken (0-10 cm after ruzigrass cultivation and subjected to soil-P fractionation. Soybean was grown thereafter without P application to seed furrow. Phosphorus availability in plots with ruzigrass was compared to the ones with spontaneous vegetation for two years. Ruzigrass cultivation increased inorganic (resin-extracted and organic (NaHCO3 soil P, as well as P concentration in soybean leaves, regardless of the P source. However, soybean yield did not increase significantly due to ruzigrass introduction to the cropping system. Soil-P availability did not differ between soluble and reactive P sources. Ruzigrass increases soil-P availability, especially where corrective P fertilization is performed.

  20. Phosphorus Accumulating Organisms and Biogeochemical Hotspots

    Science.gov (United States)

    Archibald, J.; Walter, M. T.

    2008-12-01

    Despite extensive research, many of the processes that control phosphorus (P) movement from agricultural fields to streams and lakes are not well understood. This limits our ability to develop management strategies that will mediate P contamination of freshwater ecosystems and subsequent eutrophication. Recent advances in molecular microbiology have prompted a paradigm shift in wastewater treatment that recognizes and exploits the ways specific microbial processes influence P solubility. Central to this enhanced biological phosphorus removal in wastewater treatment plants is a relatively recently discovered microorganism, Candidatus accumulibacter, which takes-up P and stores it internally as polyphosphate under alternating aerobic and anaerobic conditions. Within the past few months we have discovered this organism in the natural environment and its role in P biogeochemistry is unclear. We speculate that it may function similarly in variable source areas, which experience cycles of saturation and desaturation, as it does in the anaerobic- aerobic cycles in a wastewater treatment plant. If so, there may be potential opportunities to realize similarly new perspectives and advancements in the watershed context as have been seen in wastewater technologies. Here we present some of our preliminary findings.

  1. Geochemistry of groundwater in the Beaver and Camas Creek drainage basins, eastern Idaho

    Science.gov (United States)

    Rattray, Gordon W.; Ginsbach, Michael L.

    2014-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Energy, is studying the fate and transport of waste solutes in the eastern Snake River Plain (ESRP) aquifer at the Idaho National Laboratory (INL) in eastern Idaho. This effort requires an understanding of the natural and anthropogenic geochemistry of groundwater at the INL and of the important physical and chemical processes controlling the geochemistry. In this study, the USGS applied geochemical modeling to investigate the geochemistry of groundwater in the Beaver and Camas Creek drainage basins, which provide groundwater recharge to the ESRP aquifer underlying the northeastern part of the INL. Data used in this study include petrology and mineralogy from 2 sediment and 3 rock samples, and water-quality analyses from 4 surface-water and 18 groundwater samples. The mineralogy of the sediment and rock samples was analyzed with X-ray diffraction, and the mineralogy and petrology of the rock samples were examined in thin sections. The water samples were analyzed for field parameters, major ions, silica, nutrients, dissolved organic carbon, trace elements, tritium, and the stable isotope ratios of hydrogen, oxygen, carbon, sulfur, and nitrogen. Groundwater geochemistry was influenced by reactions with rocks of the geologic terranes—carbonate rocks, rhyolite, basalt, evaporite deposits, and sediment comprised of all of these rocks. Agricultural practices near and south of Dubois and application of road anti-icing liquids on U.S. Interstate Highway 15 were likely sources of nitrate, chloride, calcium, and magnesium to groundwater. Groundwater geochemistry was successfully modeled in the alluvial aquifer in Camas Meadows and the ESRP fractured basalt aquifer using the geochemical modeling code PHREEQC. The primary geochemical processes appear to be precipitation or dissolution of calcite and dissolution of silicate minerals. Dissolution of evaporite minerals, associated with Pleistocene Lake

  2. The Earth's early evolution.

    Science.gov (United States)

    Bowring, S A; Housh, T

    1995-09-15

    The Archean crust contains direct geochemical information of the Earth's early planetary differentiation. A major outstanding question in the Earth sciences is whether the volume of continental crust today represents nearly all that formed over Earth's history or whether its rates of creation and destruction have been approximately balanced since the Archean. Analysis of neodymium isotopic data from the oldest remnants of Archean crust suggests that crustal recycling is important and that preserved continental crust comprises fragments of crust that escaped recycling. Furthermore, the data suggest that the isotopic evolution of Earth's mantle reflects progressive eradication of primordial heterogeneities related to early differentiation.

  3. Near Earth Objects

    DEFF Research Database (Denmark)

    Wolff, Stefan

    2006-01-01

    , Near Earth Objects: Asteroids and comets following paths that bring them near the Earth. NEOs have collided with the Earth since its formation, some causing local devastation, some causing global climate changes, yet the threat from a collision with a near Earth object has only recently been recognised...... of starlight by the Sun, and therefore directly observe the structure of space-time. This thesis explores several aspects of the observation of NEOs with Gaia, emphasising detection of NEOs and the quality of orbits computed from Gaia observations. The main contribution is the work on motion detection...

  4. Biological phosphorus and nitrogen removal in a single sludge system

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, Hans

    1996-05-01

    The primary aim of this thesis was to investigate the process stability of a single sludge activated system designed for the combined operation of enhanced biological phosphorus removal (EBPR) and nitrogen removal. A pilot plant at the Sjoelunda wastewater treatment plant in Malmoe, Sweden, has formed the basis for the investigation. The pilot plant study showed that the concentration of total phosphorus on average was low in the effluent, below 0.5 mg P/l. Simultaneously with the highest concentrations of phosphorus in the effluent, the lowest COD/P ratios in the effluent were recorded. A recurrent pattern of high concentrations of phosphorus was observed every year in July, which is the industrial holiday month in Sweden. Other instances of increased phosphorus concentrations in the secondary effluent illustrate the effect of prolonged periods of rain. Increasing flow rates due to rain lead to a dilution and a change in the composition of the COD in the influent wastewater. The COD/P and VFA/P ratios decrease with decreasing concentrations of COD. It was also shown that high removal ratios of both nitrogen and phosphorus during long periods are possible. The nitrogen removal was stable during the whole investigated period, whereas the phosphorus removal was unstable during prolonged periods with low concentrations of COD in the influent water. The combined biological phosphorus and nitrogen removal process implies that during these periods the risk of recirculating nitrate to the anaerobic reactor increases. Such a recirculation both stabilizes the nitrogen removal and withdraws some of the readily degradable organic material from the bio-P bacteria. The main conclusion of this study is that a phosphorus limited EBPR process can cope with the day to day variations, but occasionally, measures have to be taken if the demands for phosphorus removal are stringent. 49 refs, 8 figs, 1 tab

  5. [Biological phosphorus removal in intermittent aerated biological filter].

    Science.gov (United States)

    Zeng, Long-Yun; Yang, Chun-Ping; Guo, Jun-Yuan; Luo, Sheng-Lian

    2012-01-01

    Under intermittent aerated and continuous fed operation where the biofilm system was subjected to alternated anaerobic/aerobic condition, the effect of influent volatile fatty acids (VFAs) concentrations, operation cycle and backwash on the biological phosphorus removal performance of the biofilter was studied. In the experiment, synthetic domestic wastewater was used, and the influent velocity was 5 L x h(-1) with gas versus liquid ratio of 8:1 and hydraulic retention time (HRT) of 1.3 h, resulting in average COD, ammonium and phosphorus load of 4.7, 0.41 and 0.095 g x (L x d) (-1) respectively. Results show that, (1) effective release and uptake of phosphorus was achieved in a operation cycle; (2) when influent VFAs was 100 mg x L(-1) (calculated by COD value) and operation cycle was 6 h the filter performed best in phosphorus removal, the phosphorus loading removal rate can be as much as 0.059 g x (L x d)(-1) at the aerated phase with those of COD and ammonium being 3.8 g x (L x d)(-1) and 0.28 g x (L x d)(-1) respectively, and with average effluent phosphorus, COD and ammonium concentrations being 1.8, 43.6 and 8.7 mg x L(-1), which shows nitrogen loss also happened; (3) the pause of backwash decreased the phosphorus removal performance rapidly with the removal efficiency lower than 40% in two days, but the consequent daily backwash operation gave a short improvement on the phosphorus removal, which disappeared in another two days. Thus, it is shown that biological phosphorus removal achieved with better phosphorus loading removal performance in the biofilter under intermittent aerated and continuous fed operation, and that sufficient and stable influent VFAs concentration, proper operation cycle, and more frequent backwash favored the performance.

  6. Capturing near-Earth asteroids around Earth

    Science.gov (United States)

    Hasnain, Zaki; Lamb, Christopher A.; Ross, Shane D.

    2012-12-01

    The list of detected near-Earth asteroids (NEAs) is constantly growing. NEAs are likely targets for resources to support space industrialization, as they may be the least expensive source of certain needed raw materials. The limited supply of precious metals and semiconducting elements on Earth may be supplemented or even replaced by the reserves floating in the form of asteroids around the solar system. Precious metals make up a significant fraction NEAs by mass, and even one metallic asteroid of ˜1km size and fair enrichment in platinum-group metals would contain twice the tonnage of such metals already harvested on Earth. There are ˜1000 NEAs with a diameter of greater than 1 km. Capturing these asteroids around the Earth would expand the mining industry into an entirely new dimension. Having such resources within easy reach in Earth's orbit could provide an off-world environmentally friendly remedy for impending terrestrial shortages, especially given the need for raw materials in developing nations. In this paper, we develop and implement a conceptually simple algorithm to determine trajectory characteristics necessary to move NEAs into capture orbits around the Earth. Altered trajectories of asteroids are calculated using an ephemeris model. Only asteroids of eccentricity less than 0.1 have been studied and the model is restricted to the ecliptic plane for simplicity. We constrain the time of retrieval to be 10 years or less, based on considerations of the time to return on investment. For the heliocentric phase, constant acceleration is assumed. The acceleration required for transporting these asteroids from their undisturbed orbits to the sphere of influence of the Earth is the primary output, along with the impulse or acceleration necessary to effect capture to a bound orbit once the Earth's sphere of influence is reached. The initial guess for the constant acceleration is provided by a new estimation method, similar in spirit to Edelbaum's. Based on the

  7. Phosphorus Utilization and Characterization of Excreta From Swine Fed Diets Containing A Variety of Cereal Grains Balanced For Total Phosphorus

    Science.gov (United States)

    Intrinsic phytase in swine feeds may alter phytate utilization and solubility of excreted phosphorus. Therefore, the objective of this experiment was to quantify changes in fecal phosphorus composition from swine fed various cereal grains with a range of phytate concentrations and endogenous phytase...

  8. Application of nonlinear analysis methods for identifying relationships between microbial community structure and groundwater geochemistry.

    Science.gov (United States)

    Schryver, Jack C; Brandt, Craig C; Pfiffner, Susan M; Palumbo, Anthony V; Peacock, Aaron D; White, David C; McKinley, James P; Long, Philip E

    2006-02-01

    The relationship between groundwater geochemistry and microbial community structure can be complex and difficult to assess. We applied nonlinear and generalized linear data analysis methods to relate microbial biomarkers (phospholipids fatty acids, PLFA) to groundwater geochemical characteristics at the Shiprock uranium mill tailings disposal site that is primarily contaminated by uranium, sulfate, and nitrate. First, predictive models were constructed using feedforward artificial neural networks (NN) to predict PLFA classes from geochemistry. To reduce the danger of overfitting, parsimonious NN architectures were selected based on pruning of hidden nodes and elimination of redundant predictor (geochemical) variables. The resulting NN models greatly outperformed the generalized linear models. Sensitivity analysis indicated that tritium, which was indicative of riverine influences, and uranium were important in predicting the distributions of the PLFA classes. In contrast, nitrate concentration and inorganic carbon were least important, and total ionic strength was of intermediate importance. Second, nonlinear principal components (NPC) were extracted from the PLFA data using a variant of the feedforward NN. The NPC grouped the samples according to similar geochemistry. PLFA indicators of Gram-negative bacteria and eukaryotes were associated with the groups of wells with lower levels of contamination. The more contaminated samples contained microbial communities that were predominated by terminally branched saturates and branched monounsaturates that are indicative of metal reducers, actinomycetes, and Gram-positive bacteria. These results indicate that the microbial community at the site is coupled to the geochemistry and knowledge of the geochemistry allows prediction of the community composition.

  9. Application of Nonlinear Analysis Methods for Identifying Relationships Between Microbial Community Structure and Groundwater Geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Schryver, Jack C.; Brandt, Craig C.; Pfiffner, Susan M.; Palumbo, A V.; Peacock, Aaron D.; White, David C.; McKinley, James P.; Long, Philip E.

    2006-02-01

    The relationship between groundwater geochemistry and microbial community structure can be complex and difficult to assess. We applied nonlinear and generalized linear data analysis methods to relate microbial biomarkers (phospholipids fatty acids, PLFA) to groundwater geochemical characteristics at the Shiprock uranium mill tailings disposal site that is primarily contaminated by uranium, sulfate, and nitrate. First, predictive models were constructed using feedforward artificial neural networks (NN) to predict PLFA classes from geochemistry. To reduce the danger of overfitting, parsimonious NN architectures were selected based on pruning of hidden nodes and elimination of redundant predictor (geochemical) variables. The resulting NN models greatly outperformed the generalized linear models. Sensitivity analysis indicated that tritium, which was indicative of riverine influences, and uranium were important in predicting the distributions of the PLFA classes. In contrast, nitrate concentration and inorganic carbon were least important, and total ionic strength was of intermediate importance. Second, nonlinear principal components (NPC) were extracted from the PLFA data using a variant of the feedforward NN. The NPC grouped the samples according to similar geochemistry. PLFA indicators of Gram-negative bacteria and eukaryotes were associated with the groups of wells with lower levels of contamination. The more contaminated samples contained microbial communities that were predominated by terminally branched saturates and branched monounsaturates that are indicative of metal reducers, actinomycetes, and Gram-positive bacteria. These results indicate that the microbial community at the site is coupled to the geochemistry and knowledge of the geochemistry allows prediction of the community composition.

  10. Improving Phosphorus Availability in an Acid Soil Using Organic Amendments Produced from Agroindustrial Wastes

    Directory of Open Access Journals (Sweden)

    Huck Ywih Ch’ng

    2014-01-01

    Full Text Available In acid soils, soluble inorganic phosphorus is fixed by aluminium and iron. To overcome this problem, acid soils are limed to fix aluminium and iron but this practice is not economical. The practice is also not environmentally friendly. This study was conducted to improve phosphorus availability using organic amendments (biochar and compost produced from chicken litter and pineapple leaves, resp. to fix aluminium and iron instead of phosphorus. Amending soil with biochar or compost or a mixture of biochar and compost increased total phosphorus, available phosphorus, inorganic phosphorus fractions (soluble inorganic phosphorus, aluminium bound inorganic phosphorus, iron bound inorganic phosphorus, redundant soluble inorganic phosphorus, and calcium bound phosphorus, and organic phosphorus. This was possible because the organic amendments increased soil pH and reduced exchangeable acidity, exchangeable aluminium, and exchangeable iron. The findings suggest that the organic amendments altered soil chemical properties in a way that enhanced the availability of phosphorus in this study. The amendments effectively fixed aluminium and iron instead of phosphorus, thus rendering phosphorus available by keeping the inorganic phosphorus in a bioavailable labile phosphorus pool for a longer period compared with application of Triple Superphosphate without organic amendments.

  11. Improving phosphorus availability in an acid soil using organic amendments produced from agroindustrial wastes.

    Science.gov (United States)

    Ch'ng, Huck Ywih; Ahmed, Osumanu Haruna; Majid, Nik Muhamad Ab

    2014-01-01

    In acid soils, soluble inorganic phosphorus is fixed by aluminium and iron. To overcome this problem, acid soils are limed to fix aluminium and iron but this practice is not economical. The practice is also not environmentally friendly. This study was conducted to improve phosphorus availability using organic amendments (biochar and compost produced from chicken litter and pineapple leaves, resp.) to fix aluminium and iron instead of phosphorus. Amending soil with biochar or compost or a mixture of biochar and compost increased total phosphorus, available phosphorus, inorganic phosphorus fractions (soluble inorganic phosphorus, aluminium bound inorganic phosphorus, iron bound inorganic phosphorus, redundant soluble inorganic phosphorus, and calcium bound phosphorus), and organic phosphorus. This was possible because the organic amendments increased soil pH and reduced exchangeable acidity, exchangeable aluminium, and exchangeable iron. The findings suggest that the organic amendments altered soil chemical properties in a way that enhanced the availability of phosphorus in this study. The amendments effectively fixed aluminium and iron instead of phosphorus, thus rendering phosphorus available by keeping the inorganic phosphorus in a bioavailable labile phosphorus pool for a longer period compared with application of Triple Superphosphate without organic amendments.

  12. Geochemistry and petrogenesis of Mesoproterozoic A-type granitoids from the Danish island of Bornholm, southern Fennoscandia

    DEFF Research Database (Denmark)

    Johansson, Åke; Waight, Tod Earle; Andersen, Tom

    2016-01-01

    Granitoids and gneisses from the Danish island of Bornholm have been investigated using whole rock geochemistry, Sr and Nd isotope geochemistry and Hf isotopes in zircon. Recent U–Pb dating shows that the rocks were formed during a short time interval at 1.45 to 1.46 Ga, penecontemporaneous...

  13. [In Situ Analysis of Element Geochemistry in Submarine Basalt in Hydrothermal Areas from Ultraslow Spreading Southwest Indian Ridge].

    Science.gov (United States)

    Wang, Yan; Sun, Xiao-ming; Xu, Li; Liang, Ye-heng; Wu, Zhong-wei; Fu, Yu; Huang, Yi

    2015-03-01

    In this study, we analyze element geochemistry of submarine basalt in situ, which is sampled in hydrothermal areas from ultraslow spreading Southwest Indian Ridge, including the fresh basalt rocks (B19-9, B15-13) and altered basalt (B5-2). And we can confirm that altered mineral in B5-2 is celadonite by microscope and Raman Spectrum. Furthermore, amygdaloidal celadonites are analyzed by electron microprobe (EPMA) and EDS-line scanning. The results show that K-contents decrease and Na-contents increase from the core to the edge in these altered minerals, indicating the transition from celadonite to saponite. Celadonite is an altered minerals, forming in low temperature (< 50 degrees C) and oxidizing condition, while saponite form in low water/rock and more reducing condition. As a result, the transition from celadonite to saponite suggests environment change from oxidizing to reducing condition. Using the result of EPMA as internal standard, we can analyze rare earth elements (REE) in altered mineral in situ. Most of result show positive Eu anomaly (Δ(Eu)), indicating hydrothermal fluid transform from oxidizing to reducing, and reducing fluid rework on the early altered minerals. Comparison with REE in matrix feldspar both in altered and unaltered zoning, we find that reducing fluid can leach REE from the matrix feldspar, leading to lower total REE concentrations and positive Eu anomaly. So leaching process play an important role in hydrothermal system.

  14. Clumped-isotope geochemistry of carbonates: A new tool for the reconstruction of temperature and oxygen isotope composition of seawater

    Energy Technology Data Exchange (ETDEWEB)

    Bernasconi, Stefano M., E-mail: Stefano.bernasconi@erdw.ethz.ch [Geological Institute, ETH Zuerich, Sonneggstrasse 5, 8092 Zuerich (Switzerland); Schmid, Thomas W.; Grauel, Anna-Lena [Geological Institute, ETH Zuerich, Sonneggstrasse 5, 8092 Zuerich (Switzerland); Mutterlose, Joerg [Institut fuer Geologie, Mineralogie und Geophysik, Ruhr Universitaet Bochum, Universitaetsstr. 150, 44801 Bochum (Germany)

    2011-06-15

    Highlights: > Clumped-isotope thermometry of carbonates is discussed. > Clumped isotopes of Belemnites show higher sea surface temperatures than commonly assumed for the lower Cretaceous. > The potential of clumped-isotope measurement on foraminifera is discussed. - Abstract: Clumped-isotope geochemistry deals with State of ordering of rare isotopes in molecules, in particular with their tendency to form bonds with other rare isotopes rather than with the most abundant ones. Among its possible applications, carbonate clumped-isotope thermometry is the one that has gained most attention because of the wide potential of applications in many disciplines of the earth sciences. In particular, it allows reconstructing the temperature of formation of carbonate minerals without knowledge of the isotopic composition of the water from which they were formed. In addition, the O isotope composition of the waters from which they were formed can be calculated using the {delta}{sup 18}O of the same carbonate sample. This feature offers new approaches in paleoclimatology for reconstructing past global geochemical cycles. In this contribution two applications of this method are presented. First the potential of a new analytical method of measurement of clumped isotopes on small samples of foraminifera, for high-resolution SST and seawater {delta}{sup 18}O reconstructions from marine sediments is shown. Furthermore the potential of clumped isotope analysis of belemnites, for reconstructing seawater {delta}{sup 18}O and temperatures in the Cretaceous is shown.

  15. Studies on the phosphorus requirement and proper calcium/phosphorus ratio in the diet of the black sea bream ( Sparus macrocephalus)

    Science.gov (United States)

    Liu, Jingke; Li, Maotang; Wang, Keling; Wang, Xincheng; Liu, Jianking

    1993-06-01

    An expriment on the phosphorus requirement and the proper Ca/P ratio in the diet of the black sea bream using the phosphorus gradient method (with casein as basic diet, sodium dihydrogen phosphate as source of phosphorus, and calcium lactate as source of calcium) showed that growth was greatly affected by the diet's phosphorus content and Ca/P ratio. Inadequate phosphorus in the diet resulted in slow growth and poor food conversion ratio (FCR). Analyses of the fish body showed it contained a high level of lipid but a low level of moisture, ash, calcium and phosphorus. The optimal values of phosphorus and Ca/P ratio in the black sea bream diet are 0.68% and 1∶2 respectively. Phosphorus in excess of this optimum value resulted in slow growth or even death. The results of this experiment clearly indicated that phosphorus is the principal mineral additive affecting black sea bream growth.

  16. Effectively Using Groundwater Geochemistry Data: A GIS Approach

    Energy Technology Data Exchange (ETDEWEB)

    Bollinger, J.S. [Westinghouse Savannah River Company, AIKEN, SC (United States)

    1998-07-01

    The Savannah River Site (SRS) has accumulated a wealth of groundwater geochemistry data during the past two decades from a large network of monitoring wells. These data, archived in an Oracle database, have been accessible only in quarterly reports or a spreadsheet format. An ArcView extension has been developed to extract the data using a simple interface. The data are filtered, processed, and returned as an ArcView theme, permitting rapid analysis and evaluation of contaminated areas.Typically, these data must be analyzed by hydrostratigraphic unit to be useful. Unfortunately, a compendium of well screen-versus-aquifer relationships for groundwater monitoring wells at SRS has not been available, making the geochemical data difficult to use and analyze. Therefore, a 3-D hydrostratigraphic model has been developed in geographic information systems (GIS) and used in conjunction with well construction data to determine the location of well screen zones within the SRS vertical hydrostratigraphy. This information has been incorporated into the ArcView extension so that geochemical data can be analyzed and displayed in ArcView by hydrostratigraphic unit.

  17. Metal stable isotope signatures as tracers in environmental geochemistry.

    Science.gov (United States)

    Wiederhold, Jan G

    2015-03-03

    The biogeochemical cycling of metals in natural systems is often accompanied by stable isotope fractionation which can now be measured due to recent analytical advances. In consequence, a new research field has emerged over the last two decades, complementing the traditional stable isotope systems (H, C, O, N, S) with many more elements across the periodic table (Li, B, Mg, Si, Cl, Ca, Ti, V, Cr, Fe, Ni, Cu, Zn, Ge, Se, Br, Sr, Mo, Ag, Cd, Sn, Sb, Te, Ba, W, Pt, Hg, Tl, U) which are being explored and potentially applicable as novel geochemical tracers. This review presents the application of metal stable isotopes as source and process tracers in environmental studies, in particular by using mixing and Rayleigh model approaches. The most important concepts of mass-dependent and mass-independent metal stable isotope fractionation are introduced, and the extent of natural isotopic variations for different elements is compared. A particular focus lies on a discussion of processes (redox transformations, complexation, sorption, precipitation, dissolution, evaporation, diffusion, biological cycling) which are able to induce metal stable isotope fractionation in environmental systems. Additionally, the usefulness and limitations of metal stable isotope signatures as tracers in environmental geochemistry are discussed and future perspectives presented.

  18. Vanadium Geochemistry of Oil Sands Fluid Petroleum Coke.

    Science.gov (United States)

    Nesbitt, Jake A; Lindsay, Matthew B J

    2017-03-07

    Vanadium has previously been linked to elevated toxicity of leachates derived from oil sands petroleum coke. However, geochemical controls on V mobility within coke deposits remain poorly constrained. Detailed examinations of porewater and solid-phase V geochemistry were therefore performed on oil sands fluid petroleum coke deposits in Alberta, Canada. Sample collection focused on both active and reclaimed deposits, which contained more than 3 × 10(7) m(3) of fluid petroleum coke. Dissolved V concentrations were highest (up to 3.0 mg L(-1)) immediately below the water table but decreased rapidly with increasing depth. This trend corresponded to a transition from mildly acidic (pH 6-7) and oxic conditions to mildly alkaline (pH 7-8.5) and anoxic conditions. Scanning electron microscopy (SEM), electron microprobe analysis (EMPA), and micro-X-ray fluorescence (μXRF) mapping revealed coke particles exhibited an internal structure characterized by successive concentric layers. The outer margins of these layers were characterized by elevated V, Fe, Si, and Al concentrations, indicating the presence of inorganic phases. Micro-X-ray absorption near-edge structure (μXANES) spectroscopy revealed that V speciation was dominated by V(IV) porphyrins except at outer margins of layers, where octahedrally coordinated V(III) was a major component. Minor to trace V(V) was also detected within fluid petroleum coke particles.

  19. Current state of the hydrothermal geochemistry studies at Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Fausto L, J.J.; Jimenez S, M.E.; Esquer P, I.

    1981-01-01

    The current state of hydrothermal geochemistry studies being carried out at the field are reported. These studies are based on the results of chemical analysis of water samples collected during 1979 and 1980 at the geothermal wells of the area known as Cerro Prieto I, as well as from those located in the Cerro Prieto II and Cerro Prieto III areas, some of which have only recently started flowing. Data are presented on the chemical variations of the main chemical constituents dissolved in the waters, as well as on the Na/K and Na-K-Ca chemical relations and the temperatures calculated from them and from SiO/sub 2/. Fluid recharge into the reservoir and its direction of flow are interpreted from isotherm contour maps of the field prepared from Na/K and Na-K-Ca geothermometry and from concentration contour maps of some of the main chemical constituents. Well M-43 is discussed as an example of a well affected by well completion problems in its production casing. Its behavior is explained on the basis of the chemical characteristics of the produced water. The chemical changes that have taken place in some of the wells during production are explained by correlating the chemistry with the production mechanisms of the well (steam-water production rates).

  20. Geology,Geochemistry and Genesis of Yinyan Porphyry Tin Deposit

    Institute of Scientific and Technical Information of China (English)

    朱正书; 朱金初; 等

    1989-01-01

    The Yinyan porphyry tin deposit is a blind deposit associated with a small granite porphyry stock.The petrology and geochemistry of the Yinyan granite porphyry suggest that it is genetically of the transfor-mation type,emplaced at the late stage of fractional crystallization within a high-level magma chamber.Ore-forming fluids are derived predominantly from the granitic magma and they interact with the wall rocks intensely when finding their way upwards through the granite porphyry.From the lower part of the porphyry upwards the following alteration zones can be distinguished(a)slightly altered granite porphyry (with weak potash feldspathization),(b)protolithionite-quartz greisenization zone,(c)to-paz-quartz greisenization zone,(d)senicite-quartz sericitization zone,and (e)silicification zone (quartz core at the surface).Tin mineralization is related to greisenization,especially to topaz-quartz greisenization.Rock and ore-forming temperatures and oxygen fugacities are estimated,respectively.There are significant differences in many aspects between the Yinyan porphyry tin deposit and volcan-ic-subvolcanic porphyry tin deposits.

  1. Ca isotopic geochemistry of an Antarctic aquatic system

    Science.gov (United States)

    Lyons, W. Berry; Bullen, Thomas D.; Welch, Kathleen A.

    2017-01-01

    The McMurdo Dry Valleys, Antarctica, are a polar desert ecosystem. The hydrologic system of the dry valleys is linked to climate with ephemeral streams that flow from glacial melt during the austral summer. Past climate variations have strongly influenced the closed-basin, chemically stratified lakes on the valley floor. Results of previous work point to important roles for both in-stream processes (e.g., mineral weathering, precipitation and dissolution of salts) and in-lake processes (e.g., mixing with paleo-seawater and calcite precipitation) in determining the geochemistry of these lakes. These processes have a significant influence on calcium (Ca) biogeochemistry in this aquatic ecosystem, and thus variations in Ca stable isotope compositions of the waters can aid in validating the importance of these processes. We have analyzed the Ca stable isotope compositions of streams and lakes in the McMurdo Dry Valleys. The results validate the important roles of weathering of aluminosilicate minerals and/or CaCO3 in the hyporheic zone of the streams, and mixing of lake surface water with paleo-seawater and precipitation of Ca-salts during cryo-concentration events to form the deep lake waters. The lakes in the McMurdo Dry Valleys evolved following different geochemical pathways, evidenced by their unique, nonsystematic Ca isotope signatures.

  2. EarthChem: Next Developments to Meet New Demands (Invited)

    Science.gov (United States)

    Lehnert, K. A.; Walker, D.; Block, K. A.; Ash, J. M.; Chan, C.

    2009-12-01

    EarthChem is a community-driven effort to facilitate the discovery, access, and preservation of geochemical data to support research and enable new and better science. After its first 4 years of development, EarthChem has established itself as a leading community resource that offers to its users a range of data services comprising: the EarthChem Portal as a central access point to geochemical data in federated databases with tools for data discovery, data access, and data analysis; the Geochemical Resource Library that serves as a repository for user-submitted data and features an online submission tool and a searchable metadata catalog; topical data collections such as the Deep Lithosphere Dataset that are developed and maintained by EarthChem; and GEOCHRON, a system for easy population and access of geochronology and thermochronology data. Growing demands for user-based data contributions, long-term data archiving, interoperability, and expanded data coverage will be addressed in EarthChem’s next development phase, during which EarthChem will enhance its information technology infrastructure, create new digital content, expand partnerships, and continue to promote the implementation of more open and standardized data reporting in geochemistry. Large emphasis will be placed on the development of services that help investigators to organize and manage their data in a way that submission of the data and metadata to EarthChem becomes effortless, seamless, and comprehensive, and that also facilitates the publication of data. The new EarthChem Repository will provide data storage and stewardship for the widest range of geochemical data sets and data collections, with tools for data submission and a data publication service that will allow users to obtain Digital Object Identifier for Scientific Primary Data (STD-DOI) to make their submitted data citable as publications. These applications are expected to ensure more efficient and timely growth of the data

  3. Introducing Earth's Orbital Eccentricity

    Science.gov (United States)

    Oostra, Benjamin

    2015-01-01

    Most students know that planetary orbits, including Earth's, are elliptical; that is Kepler's first law, and it is found in many science textbooks. But quite a few are mistaken about the details, thinking that the orbit is very eccentric, or that this effect is somehow responsible for the seasons. In fact, the Earth's orbital eccentricity is…

  4. The Earth's Core.

    Science.gov (United States)

    Jeanloz, Raymond

    1983-01-01

    The nature of the earth's core is described. Indirect evidence (such as that determined from seismological data) indicates that it is an iron alloy, solid toward its center but otherwise liquid. Evidence also suggests that it is the turbulent flow of the liquid that generates the earth's magnetic field. (JN)

  5. Solid Earth: Introduction

    Science.gov (United States)

    Rummel, R.

    1991-10-01

    The principles of the solid Earth program are introduced. When considering the study of solid Earth from space, satellites are used as beacons, inertial references, free fall probes and carrying platforms. The phenomenon measured by these satellites and the processes which can be studied as a result of these measurements are tabulated. The NASA solid Earth program focusses on research into surface kinematics, Earth rotation, land, ice, and ocean monitoring. The ESA solid Earth program identifies as its priority the Aristoteles mission for determining the gravity and magnetic field globally, with high spatial resolution and high accuracy. The Aristoteles mission characteristics and goals are listed. The benefits of the improved gravity information that will be provided by this mission are highlighted. This information will help in the following research: geodesy, orbit mechanics, geodynamics, oceanography, climate sea level, and the atmosphere.

  6. Fluctuating plasma phosphorus level by changes in dietary phosphorus intake induces endothelial dysfunction

    OpenAIRE

    Watari, Eriko; Taketani, Yutaka; Kitamura, Tomoyo; Tanaka, Terumi; Ohminami, Hirokazu; Abuduli, Maerjianghan; Harada, Nagakatsu; Yamanaka-Okumura, Hisami; Yamamoto, Hironori; Takeda, Eiji

    2014-01-01

    High serum phosphorus (P) impairs endothelial function by increasing oxidative stress and decreasing nitric oxide production. Serum P levels fluctuate due to circadian rhythms or dietary P intake in healthy people and due to dialysis in end-stage chronic kidney disease patients. Here we examined whether fluctuating plasma P caused by changes in dietary P intake may be involved in endothelial dysfunction, resulting in increased cardiovascular risk. Rats were fed a diet containing 0.6% P for 16...

  7. Microbial Phytase and Phosphorus Utilization by Broiler Chickens

    Directory of Open Access Journals (Sweden)

    Martin Kliment

    2012-05-01

    Full Text Available The aim of study was to investigate the mathematical and statistical assesment of the micorbial 6-phytase efficacy on phosphorus utilization at broiler chickens Cobb 500. Broiler chickens fed commercial feed mixtures based on soyabean-maize meal. Each feed mixture was fed ad libitum to chickens in boxes in commercial poultry farm. The trial consited of three groups of broiler chickens, one control group (CG and two trial groups, in which were broiler chickens fed by feed mixtures with decreased phosphorus content (TG1 and with microbial 6-phytase (TG2. A body weight of chickens at the end of the trial (42 day was 1900.0 g compared with 1883,0 g (TG1 and 1827.0 g (CG with not statistically significant differences (P≥0.05. Phosphorus, calcium and magnesium content in blood serum of broiler chickens in every group was not staticstically significant (P≥0.05. Phosphorus content in broiler chickens excreta was most higher in in control group (4.2556 g/kg in comparison with trial group (2.0911 g/kg were was microbial 6-phytase added and in trial group (3.1851 g/kg were was phosphorus content in feed mixtures decreased. In addition we concluded that microbial 6-phytase. Phytase addition into feed mixtures has not negative effect on broiler chickens growth ability and health, and helped to better utilization of phytate phosphorus from feed mixtures in relation to excreted phosphorus.

  8. Preliminary analysis of phosphorus flow in Hue Citadel.

    Science.gov (United States)

    Anh, T N Q; Harada, H; Fujii, S; Anh, P N; Lieu, P K; Tanaka, S

    2016-01-01

    Characteristics of waste and wastewater management can affect material flows. Our research investigates the management of waste and wastewater in urban areas of developing countries and its effects on phosphorus flow based on a case study in Hue Citadel, Hue, Vietnam. One hundred households were interviewed to gain insight into domestic waste and wastewater management together with secondary data collection. Next, a phosphorus flow model was developed to quantify the phosphorus input and output in the area. The results showed that almost all wastewater generated in Hue Citadel was eventually discharged into water bodies and to the ground/groundwater. This led to most of the phosphorus output flowing into water bodies (41.2 kg P/(ha year)) and ground/groundwater (25.3 kg P/(ha year)). Sewage from the sewer system was the largest source of phosphorus loading into water bodies, while effluent from on-site sanitation systems was responsible for a major portion of phosphorus into the ground/groundwater. This elevated phosphorus loading is a serious issue in considering surface water and groundwater protection.

  9. Black phosphorus saturable absorber for ultrashort pulse generation

    Energy Technology Data Exchange (ETDEWEB)

    Sotor, J., E-mail: jaroslaw.sotor@pwr.edu.pl; Sobon, G.; Abramski, K. M. [Laser and Fiber Electronics Group, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, Wroclaw 50-370 (Poland); Macherzynski, W.; Paletko, P. [Faculty of Microsystem Electronics and Photonics, Wroclaw University of Technology, Janiszewskiego 11/17, Wroclaw 50-372 (Poland)

    2015-08-03

    Low-dimensional materials, due to their unique and versatile properties, are very interesting for numerous applications in electronics and optoelectronics. Recently rediscovered black phosphorus, with a graphite-like layered structure, can be effectively exfoliated up to the single atomic layer called phosphorene. Contrary to graphene, it possesses a direct band gap controllable by the number of stacked atomic layers. For those reasons, black phosphorus is now intensively investigated and can complement or replace graphene in various photonics and electronics applications. Here, we demonstrate that black phosphorus can serve as a broadband saturable absorber and can be used for ultrashort optical pulse generation. The mechanically exfoliated ∼300 nm thick layers of black phosphorus were transferred onto the fiber core, and under pulsed excitation at 1560 nm wavelength, its transmission increases by 4.6%. We have demonstrated that the saturable absorption of black phosphorus is polarization sensitive. The fabricated device was used to mode-lock an Er-doped fiber laser. The generated optical solitons with the 10.2 nm bandwidth and 272 fs duration were centered at 1550 nm. The obtained results unambiguously show that black phosphorus can be effectively used for ultrashort pulse generation with performances similar or even better than currently used graphene or carbon nanotubes. This application of black phosphorus proves its great potential to future practical use in photonics.

  10. A Novel Approach to Bioleach Soluble Phosphorus from Rock Phosphate

    Institute of Scientific and Technical Information of China (English)

    池汝安; 肖春桥; 黄晓慧; 王存文; 吴元欣

    2007-01-01

    A novel approach to bioleach soluble phosphorus from rock phosphate, involving the bio-oxidation of pyrite by adaptated Acidithiobacillus ferrooxidans (At. f) and the product of sulfuric acid to dissolve rock phosphate, has been proposed in this paper. The soluble phosphorus could be leached more effectively in the presence of pyrite by At. f than that leached directly by sulfuric acid. The optimal technological parameters are presented. The highest phosphorus leaching rate is 9.00% when the culture substrate is the mixture of FeSO4·7H2O and pyrite, the phosphorus leaching rate is 8.00% when the initial pH and culture time are 2.5 and 5 d, respectively. The optimal rock phosphate particle size is 0.05 mm for the leaching of phosphorus. The bigger the grains of pyrite, the lower the phosphorus leaching rate. The bacterium At. f should be appropriately adaptated, which makes it easier to bioleach soluble phosphorus from rock phosphate.

  11. Effect of pH on biological phosphorus uptake.

    Science.gov (United States)

    Serralta, J; Ferrer, J; Borrás, L; Seco, A

    2006-12-05

    An anaerobic aerobic laboratory scale sequencing batch reactor (SBR) was operated to study the effect of pH on enhanced biological phosphorus removal. Seven steady states were achieved under different operating conditions. In all of them, a slight variation in the pH value was observed during anaerobic phase. However, pH rose significantly during aerobic phase. The increase observed was due to phosphorus uptake and carbon dioxide stripping. When pH was higher than 8.2-8.25 the phosphorus uptake rate clearly decreased. The capability of Activated Sludge Model No. 2d (ASM2d) and Biological Nutrient Removal Model No. 1 (BNRM1) to simulate experimental results was evaluated. Both models successfully characterized the enhanced biological phosphorus removal performance of the SBR. Furthermore, BNRM1 also reproduced the pH variations observed and the decrease in the phosphorus uptake rate. This model includes a switch function in the kinetic expressions to represent the pH inhibition in biological processes. The pH inhibition constants related to polyphosphate storage process were obtained by adjusting model predictions to measured phosphorus concentrations. On the other hand, pH inhibition should be included in ASM2d to accurately simulate experimental phosphorus evolution observed in an A/O SBR.

  12. Cold seeps in Monterey Bay, California: Geochemistry of pore waters and relationship to benthic foraminiferal calcite

    Energy Technology Data Exchange (ETDEWEB)

    Gieskes, Joris, E-mail: jgieskes@ucsd.edu [Scripps Institution of Oceanography, IOD-0208, 9500 Gilman Drive, La Jolla, CA 92093-0208 (United States); Rathburn, Anthony E. [Scripps Institution of Oceanography, IOD-0208, 9500 Gilman Drive, La Jolla, CA 92093-0208 (United States)] [Indiana State University, Department of Earth and Environmental Systems, Terre Haute, IN 47809 (United States); Martin, Jonathan B. [University of Florida, Department of Geological Sciences, Gainesville, FL 32611-2120 (United States); Perez, M. Elena [Indiana State University, Department of Earth and Environmental Systems, Terre Haute, IN 47809 (United States)] [The Natural History Museum, Department of Palaeontology, Cromwell Road, London SW7 5BD (United Kingdom); Mahn, Chris [Scripps Institution of Oceanography, IOD-0208, 9500 Gilman Drive, La Jolla, CA 92093-0208 (United States); Bernhard, Joan M. [Woods Hole Oceanographic Institution, Geology and Geophysics Department, MS52, Woods Hole, MA 02543 (United States); Day, Shelley [University of Florida, Department of Geological Sciences, Gainesville, FL 32611-2120 (United States)

    2011-05-15

    Highlights: > We describe the geochemistry of pore waters in the Clam Flats area of Monterey Bay. > The geochemical data are compared with the {delta}{sup 13}C chemistry of benthic foraminifera. > Living foraminifera indicate little effects of pore water low {delta}{sup 13}C (DIC) in the clam bed. > This phenomenon and its implications are discussed in detail. > Implications with regards to paleo-methane seepage are discussed. - Abstract: An extensive geochemical and biogeochemical examination of CH{sub 4} seeps in the Clam Flats area of Monterey Bay provides insight into the character of relationships between seep geochemistry and benthic foraminiferal geochemistry. The area is characterized by sulfide-rich fluids. Sulfide increases are associated with large increases in alkalinity, as well as small decreases in dissolved Ca and Mg. In addition, only small increases in NH{sub 4} are observed, but values of {delta}{sup 13}C of dissolved inorganic C are as low as -60 per mille at shallow depths (<3 cm). These observations indicate that all these processes are related to the bacterial oxidation of CH{sub 4}, which is transported upward by slow seepage of pore fluids. The geochemistry of the pore fluids should be relevant to the geochemistry of the carbonate tests of living and dead foraminifera. However, a profound disequilibrium of approximately an order of magnitude occurs between the {delta}{sup 13}C values of stained (cytoplasm-containing) foraminiferal carbonate and the C isotope values of ambient pore water dissolved inorganic C. Reasons are unclear for this isotopic disequilibrium, but have important implications for interpretations of foraminiferal carbonate as a paleoenvironmental proxy. Much fine scale work is needed to fully understand the relationships between the biogeochemistry of benthic foraminifera and the geochemistry of the pore waters where they live.

  13. Mass transfer of phosphorus in high-phosphorus hot-metal refining

    Institute of Scientific and Technical Information of China (English)

    Jiang Diao; Xuan Liu,; Tao Zhang; Bing Xie

    2015-01-01

    Mass transfer of phosphorus in high-phosphorus hot-metal refining was investigated using CaO−FetO−SiO2 slags at 1623 K. Based on a two-film theory kinetic model and experimental results, it was found that the overall mass transfer coefficient, which includes the effects of mass transfer in both the slag phase and metal phase, is in the range of 0.0047 to 0.0240 cm/s. With the addition of a small amount of fluxing agents Al2O3 or Na2O into the slag, the overall mass transfer coefficient has an obvious increase. Silicon content in the hot metal also influences the overall mass transfer coefficient. The overall mass transfer coefficient in the lower [Si] heat is much higher than that in the higher [Si] heat. It is concluded that both fluxing agents and lower [Si] hot metal facilitate mass transfer of phosphorus in liquid phases. Fur-thermore, the addition of Na2O could also prevent rephosphorization at the end of the experiment.

  14. Microbial phytases in phosphorus acquisition and plant growth promotion.

    Science.gov (United States)

    Singh, Bijender; Satyanarayana, T

    2011-04-01

    Phosphorus (P) is one of the major constituents in energy metabolism and biosynthesis of nucleic acids and cell membranes with an important role in regulation of a number of enzymes. Soil phosphorous is an important macronutrient for plant growth. Phosphorus deficiency in soil is a major problem for agricultural production. Total soil P occurs in either organic or in organic form. Phytic acid as phytate (salts of phytic acid) is the major form of organic phosphorus in soil and it is not readily available to plants as a source of phosphorus because it either forms a complex with cations or adsorbs to various soil components. Phosphate solubilizing microorganisms are ubiquitous in soils and could play an important role in supplying P to plants. Microorganisms utilizing phytate are found in cultivated soils as well as in wetland, grassland and forest soils. Various fungi and bacteria (including plant growth promoting rhizobacteria) hydrolyze this organic form of phosphorus secreting phosphatases such as phytases and acidic/alkaline phosphatases. A large number of transgenic plants have been developed which were able to utilize sodium phytate as sole source of phosphorus. However, the recombinant phytases were similar to their wild type counterparts in terms of their properties. Increased phytase/phosphatase activity in transgenic plants may be an effective approach to promote their phytate-phosphorus utilization. The extracellular phytase activity of transgenic plant roots is a significant factor in the utilization of phosphorus from phytate. Furthermore, this indicated that an opportunity exists for using gene technology to improve the ability of plants to utilize accumulated forms of soil organic phosphorus. This review is focused on the role of phytases and phytase producing microbes in promoting the growth of different plants.

  15. Cooperative Institute for Dynamic Earth Research (CIDER): Contributions to Education (Invited)

    Science.gov (United States)

    Romanowicz, B. A.

    2010-12-01

    The Cooperative Institute for Dynamic Earth Research (http://www.deep-earth.org) began its activities in 2003 and has so far held four summer programs of duration ranging from 3 to 7 weeks, funded by the NSF/CSEDI program, with support from and at the Kavli Institute for Theoretical Physics in Santa Barbara. CIDER's goals are twofold: (1) as a "synthesis center", to provide an environment for transformative studies of Earth's internal dynamics, requiring a concerted multi-disciplinary effort of leading researchers, and (2) to educate a new generation of Earth scientists with a breadth of competence across the disciplines required to understand the dynamic earth: mineral physics, geodynamics, geochemistry and geomagnetism. CIDER summer programs, so far, have focused on themes related to the Deep Earth: "Reconciling seismic and geochemical heterogeneity in the Earth", "The Earth's transition zone", "Boundary layers in the Earth" and "Fluids and volatiles in the Earth's mantle and core". These programs typically include three weeks of unstructured program designed for senior (assistant professor level and higher) researchers, and a 3-4 weeks "tutorial and workshop" part geared towards advanced graduate students and post-docs, but open also to more senior participants. The first two weeks of the tutorial part include lectures and practical exercises in the different disciplines aimed at providing participants with a basic understanding of the fundamentals and current challenges in disciplines other than their own. During the second week, topics related to the summer program's theme are proposed for further study in a workshop mode by multi-disciplinary groups formed on the fly, continued through the last week or two of the program. These activities often lead to the development of new collaborations and research proposals to the CSEDI program. In 2011, CIDER will hold a summer program at UC Berkeley on the theme "Mountain Building", expanding the scope of the Institute

  16. Remaining Phosphorus Estimate Through Multiple Regression Analysis

    Institute of Scientific and Technical Information of China (English)

    M. E. ALVES; A. LAVORENTI

    2006-01-01

    The remaining phosphorus (Prem), P concentration that remains in solution after shaking soil with 0.01 mol L-1 CaCl2 containing 60 μg mL-1 P, is a very useful index for studies related to the chemistry of variable charge soils. Although the Prem determination is a simple procedure, the possibility of estimating accurate values of this index from easily and/or routinely determined soil properties can be very useful for practical purposes. The present research evaluated the Premestimation through multiple regression analysis in which routinely determined soil chemical data, soil clay content and soil pH measured in 1 mol L-1 NaF (pHNaF) figured as Prem predictor variables. The Prem can be estimated with acceptable accuracy using the above-mentioned approach, and PHNaF not only substitutes for clay content as a predictor variable but also confers more accuracy to the Prem estimates.

  17. Regulating phosphorus from the agricultural sector

    DEFF Research Database (Denmark)

    Hansen, Line Block; Hansen, Lars Gårn; Rubæk, Gitte Holton

    2010-01-01

    do not take into account the importance of P already stored in the soils. Phosphorus stored in the soils is the major source of P losses to surface waters, but at the same time crucial for the soils ability to sustain a viable crop production. Even if measures on P losses from agricultural areas...... could be obtained, such measures may not truly reflect stocks and hence potential risks associated with eg erosion, run-off or climate change. This calls for a method which handles the continuous supply of P to the soils (the current flow effect), P accumulated in the soil (a stock effect......) and the interactions between these two sources. In this paper such a model is outlined and discussed....

  18. Biological phosphorus cycling in dryland regions

    Science.gov (United States)

    Belnap, Jayne; Bunemann, Else; Oberson, Astrid; Frossard, Emmanuel

    2011-01-01

    The relatively few studies done on phosphorus (P) cycling in arid and semiarid lands (drylands) show many factors that distinguish P cycling in drylands from that in more mesic regions. In drylands, most biologically relevant P inputs and losses are from the deposition and loss of dust. Horizontal and vertical redistribution of P is an important process. P is concentrated at the soil surface and thus vulnerable to loss via erosion. High pH and CaCO3 limit P bioavailability, and low rainfall limits microbe and plant ability to free abiotically bound P via exudates, thus making it available for uptake. Many invasive plants are able to access recalcitrant P more effectively than are native plants. As P availability depends on soil moisture and temperature, climate change is expected to have large impacts on P cycling

  19. Radio search for interstellar phosphorus compounds

    Energy Technology Data Exchange (ETDEWEB)

    Hollis, J.M.; Snyder, L.E.; Lovas, F.J.; Ulich, B.L.

    1980-10-01

    The J=1--0 and 3--2 transitions of phosphorus nitride, PN, with resolvable hyperfine components at 46.99 GHz and blended components at 140.97 GHz, and transitions of phosphine, PH/sub 3/, at 47.39 and 46.94 GHz, arising from a small induced dipole moment, have been searched for but not found in interstellar molecular clouds. The J=3/2--1/2, F=3/2--3/2 transition of nitric oxide, NO, and the J/sub K/-K+=16/sub 4,12/15/sub 5,11/ transition of sulfur dioxide, SO/sub 2/, have been detected in Orion and Sagittarius B2. An unidentified emission line, U140921.8 MHz, has been observed in IRC+10216.

  20. A radio search for interstellar phosphorus compounds

    Science.gov (United States)

    Hollis, J. M.; Snyder, L. E.; Lovas, F. J.; Ulich, B. L.

    1980-01-01

    The J = 1-0 and 3-2 transitions of phosphorus nitride, PN, with resolvable hyperfine components at 46.99 GHz and blended components at 140.97 GHz, and transitions of phosphine, PH3, at 47.39 and 46.94 GHz, arising from a small induced dipole moment, have been searched for but not found in interstellar molecular clouds. The J = 3/2-1/2, F - 3/2-3/2 transition of nitric oxide, NO, and the J(K-K+) = 16(4, 12) -15(5, 11) transition of sulfur dioxide, SO2, have been detected in Orion and Sagittarius B2. An unidentified emission line, U140921.8 MHz, has been observed in IRC + 10216.