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Sample records for lwr water chemistry

  1. Water Chemistry: Seeking Information

    ERIC Educational Resources Information Center

    Delfino, Joseph J.

    1977-01-01

    A survey of the available literature in water chemistry is presented. Materials surveyed include: texts, reference books, bibliographic resources, journals, American Chemical Society publications, proceedings, unpublished articles, and reports. (BT)

  2. Water Chemistry Laboratory Manual.

    ERIC Educational Resources Information Center

    Jenkins, David; And Others

    This manual of laboratory experiments in water chemistry serves a dual function of illustrating fundamental chemical principles of dilute aqueous systems and of providing the student with some familiarity with the chemical measurements commonly used in water and wastewater analysis. Experiments are grouped in categories on the basis of similar…

  3. Characterization and chemistry of fission products released from LWR fuel under accident conditions

    SciTech Connect

    Norwood, K.S.; Collins, J.L.; Osborne, M.F.; Lorenz, R.A.; Wichner, R.P.

    1984-01-01

    Segments from commercial LWR fuel rods have been tested at temperatures between 1400 and 2000/sup 0/C in a flowing steam-helium atmosphere to simulate severe accident conditions. The primary goals of the tests were to determine the rate of fission product release and to characterize the chemical behavior. This paper is concerned primarily with the identification and chemical behavior of the released fission products with emphasis on antimony, cesium, iodine, and silver. The iodine appeared to behave primarily as cesium iodide and the antimony and silver as elements, while cesium behavior was much more complex. 17 refs., 7 figs., 1 tab.

  4. Feasibility of Water Cooled Thorium Breeder Reactor Based on LWR Technology

    SciTech Connect

    Takaki, Naoyuki; Permana, Sidik; Sekimoto, Hiroshi

    2007-07-01

    The feasibility of Th-{sup 233}U fueled, homogenous breeder reactor based on matured conventional LWR technology was studied. The famous demonstration at Shipping-port showed that the Th-{sup 233}U fueled, heterogeneous PWR with four different lattice fuels was possible to breed fissile but its low averaged burn-up including blanket fuel and the complicated core configuration were not suitable for economically competitive reactor. The authors investigated the wide design range in terms of fuel cell design, power density, averaged discharge burn-up, etc. to determine the potential of water-cooled Th reactor as a competitive breeder. It is found that a low moderated (MFR=0.3) H{sub 2}O-cooled reactor with comparable burn-up with current LWR is feasible to breed fissile fuel but the core size is too large to be economical because of the low pellet power density. On the other hand, D{sub 2}O-cooled reactor shows relatively wider feasible design window, therefore it is possible to design a core having better neutronic and economic performance than H{sub 2}O-cooled. Both coolant-type cores show negative void reactivity coefficient while achieving breeding capability which is a distinguished characteristics of thorium based fuel breeder reactor. (authors)

  5. Water chemistry and poultry processing water quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study examined the influences of water chemistry on the quality of process water used in immersion chillers. During commercial poultry processing the bird carcasses come in direct contact with process water during washing and chilling operations. Contamination of the process water with bacteria...

  6. Water Chemistry Education

    ERIC Educational Resources Information Center

    Hindin, Ervin

    1975-01-01

    Describes the purpose, content, and relevancy of courses dealing with natural and artificial aquatic environments, including surface water and ground water systems as well as water and waste treatment processes. Describes existing programs which are offered at the graduate level in this subject area. (MLH)

  7. Storage of LWR (light-water-reactor) spent fuel in air

    SciTech Connect

    Thomas, L.E.; Charlot, L.A.; Coleman, J.E. ); Knoll, R.W. )

    1989-12-01

    An experimental program is being conducted at Pacific Northwest Laboratory (PNL) to determine the oxidation response of light-water-reactor (LWR) spent fuels under conditions appropriate to fuel storage in air. The program is designed to investigate several independent variables that might affect the oxidation behavior of spent fuel. Included are temperature (135 to 230{degree}C), fuel burnup (to about 34 MWd/kgM), reactor type (pressurized and boiling water reactors), moisture level in the air, and the presence of a high gamma field. In continuing tests with declad spent fuel and nonirradiated UO{sub 2} specimens, oxidation rates were monitored by weight-gain measurements and the microstructures of subsamples taken during the weighing intervals were characterized by several analytical methods. The oxidation behavior indicated by weight gain and time to form powder will be reported in Volume III of this series. The characterization results obtained from x-ray diffractometry, transmission electron microscopy, scanning electron microscopy, and Auger electron spectrometry of oxidized fuel samples are presented in this report. 28 refs., 21 figs., 3 tabs.

  8. Green chemistry oriented organic synthesis in water.

    PubMed

    Simon, Marc-Olivier; Li, Chao-Jun

    2012-02-21

    The use of water as solvent features many benefits such as improving reactivities and selectivities, simplifying the workup procedures, enabling the recycling of the catalyst and allowing mild reaction conditions and protecting-group free synthesis in addition to being benign itself. In addition, exploring organic chemistry in water can lead to uncommon reactivities and selectivities complementing the organic chemists' synthetic toolbox in organic solvents. Studying chemistry in water also allows insight to be gained into Nature's way of chemical synthesis. However, using water as solvent is not always green. This tutorial review briefly discusses organic synthesis in water with a Green Chemistry perspective. PMID:22048162

  9. Water, water everywhere, and its remarkable chemistry.

    PubMed

    Barber, Jim

    2004-04-12

    Photosystem II (PSII), the multisubunit pigment-protein complex localised in the thylakoid membranes of oxygenic photosynthetic organisms, uses light energy to drive a series of remarkable reactions leading to the oxidation of water. The products of this oxidation are dioxygen, which is released to the atmosphere, and reducing equivalents destined to reduce carbon dioxide to organic molecules. The water oxidation occurs at catalytic sites composed of four manganese atoms (Mn(4)-cluster) and powered by the redox potential of an oxidised chlorophyll a molecule (P680(*+)). Gerald T (Jerry) Babcock and colleagues showed that electron/proton transfer processes from substrate water to P680(*+) involved a tyrosine residue (Y(Z)) and proposed an attractive reaction mechanism for the direct involvement of Y(Z) in the chemistry of water oxidation. The 'hydrogen-atom abstract/metalloradical' mechanism he formulated is an expression of his genius and a highlight of his many other outstanding contributions to photosynthesis research. A structural basis for Jerry's model is now being revealed by X-ray crystallography. PMID:15100024

  10. Perspective: Water cluster mediated atmospheric chemistry

    SciTech Connect

    Vaida, Veronica

    2011-07-14

    The importance of water in atmospheric and environmental chemistry initiated recent studies with results documenting catalysis, suppression and anti-catalysis of thermal and photochemical reactions due to hydrogen bonding of reagents with water. Water, even one water molecule in binary complexes, has been shown by quantum chemistry to stabilize the transition state and lower its energy. However, new results underscore the need to evaluate the relative competing rates between reaction and dissipation to elucidate the role of water in chemistry. Water clusters have been used successfully as models for reactions in gas-phase, in aqueous condensed phases and at aqueous surfaces. Opportunities for experimental and theoretical chemical physics to make fundamental new discoveries abound. Work in this field is timely given the importance of water in atmospheric and environmental chemistry.

  11. Fog water chemistry in Shanghai

    NASA Astrophysics Data System (ADS)

    Li, Pengfei; Li, Xiang; Yang, Chenyu; Wang, Xinjun; Chen, Jianmin; Collett, Jeffrey L., Jr.

    2011-08-01

    With the aim of understanding the fog chemistry in a Chinese megacity, twenty-six fog water samples were collected in urban Shanghai from March 2009 to March 2010. The following parameters were measured: pH, electrical conductivity (EC), ten inorganic major ions ( SO42-, NO3-, NO2-, F -, Cl -, Na +, K +, Ca 2+, Mg 2+, NH4+) and four major organic acids (CH 3COO -, HCOO -, CO42-, MSA). The total ionic concentration (TIC) and EC of fog samples were one or two orders of magnitude higher than those often found in Europe, North America and other Asian countries. Pollutants were expected to be mainly from local sources, including factories, motor vehicle emissions and civil construction. Non-local sources such as moderate- and long-range transport of sea salt also contributed to pollution levels in fog events as indicated by back trajectory analysis. The pH of the fog water collected during the monitoring period varied from 4.68 to 6.58; acidic fogs represented about 30.8% of the total fog events during this period. The fog water was characterized by high concentrations of SO42- (20.0% of measured TIC), NO3- (17.1%), NH4+ (28.3%) and Ca 2+ (14.4%). SO42- and NO3-, the main precursors of fog acidity, were related to burning fossil fuels and vehicle emissions, respectively. NH4+, originating from the scavenging of gaseous ammonia and particulate ammonium nitrate and ammonium sulfate, and Ca 2+, originating from the scavenging of coarse particles, acted as acid neutralizers and were the main cause for the relatively high pH of fogs in Shanghai. The ratio of ( SO42- + NO3-)/( NH4+ + Ca 2+) was lower than 1, indicating the alkaline nature of the fog water. A high ratio of NO3-/ SO42- and low ratio of HCOO -/CH 3COO - were consistent with large contributions from vehicular emissions that produce severe air pollution in megacities.

  12. Condensate and feedwater systems, pumps, and water chemistry. Volume seven

    SciTech Connect

    Not Available

    1986-01-01

    Subject matter includes condensate and feedwater systems (general features of condensate and feedwater systems, condenser hotwell level control, condensate flow, feedwater flow), pumps (principles of fluid flow, types of pumps, centrifugal pumps, positive displacement pumps, jet pumps, pump operating characteristics) and water chemistry (water chemistry fundamentals, corrosion, scaling, radiochemistry, water chemistry control processes, water pretreatment, PWR water chemistry, BWR water chemistry, condenser circulating water chemistry.

  13. A review of irradiation effects on LWR core internal materials - IASCC susceptibility and crack growth rates of austenitic stainless steels

    NASA Astrophysics Data System (ADS)

    Chopra, O. K.; Rao, A. S.

    2011-02-01

    Austenitic stainless steels (SSs) are used extensively as structural alloys in the internal components of light water reactor (LWR) pressure vessels because of their relatively high strength, ductility, and fracture toughness. However, exposure to neutron irradiation for extended periods changes the microstructure (radiation hardening) and microchemistry (radiation-induced segregation) of these steels, and degrades their fracture properties. Irradiation-assisted stress corrosion cracking (IASCC) is another degradation process that affects LWR internal components exposed to neutron radiation. The existing data on irradiated austenitic SSs were reviewed to evaluate the effects of key parameters such as material composition, irradiation dose, and water chemistry on IASCC susceptibility and crack growth rates of these materials in LWR environments. The significance of microstructural and microchemistry changes in the material on IASCC susceptibility is also discussed. The results are used to determine (a) the threshold fluence for IASCC and (b) the disposition curves for cyclic and IASCC growth rates for irradiated SSs in LWR environments.

  14. Water Treatment Technology - Chemistry/Bacteriology.

    ERIC Educational Resources Information Center

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on chemistry/bacteriology provides instructional materials for twelve competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: waterborne diseases, water sampling…

  15. Water chemistry affects catfish susceptibility to columnaris

    Technology Transfer Automated Retrieval System (TEKTRAN)

    While columnaris disease has been well-studied, little is known about how specific water chemistries can affect attachment. Recent studies in our labs offer new insight on this subject. Well waters from the USDA/ARS Stuttgart National Aquaculture Research Center (SNARC; Stuttgart, Arkansas) and fr...

  16. Enhanced water management using bromine chemistry

    SciTech Connect

    Sergent, R.H.

    1986-01-01

    This paper focuses on bromine chemistry and some of its unique properties, with regard to providing solutions to new and changing problems. Bromine Chemistry offers many unique properties for enhancing a water management program. Regardless of the method used to generate a residual, hypobromous acid delivers faster kill rates than an equimolar concentration of hypochlorous acid at an elevated pH or in the presence of ammonia or nitrogenous materials. In addition, the faster degradation of most bromine compounds relative to their chlorinated analogs increases the environmental acceptability of most brominated effluents relative to chlorination. Based on these advantages, the application of bromine chemistry to water treatment requirements has moved out of the speculative research phase and has moved into the sphere of a practical, commercial reality.

  17. Chemistry of saline-water chlorination

    SciTech Connect

    Haag, W.R.

    1981-06-01

    Vast quantities of natural waters are used by power plants for cooling purposes. This water is chlorinated to prevent slime build-up inside the cooling pipes, is circulated through the cooling system, and eventually discharged back into the water body. In order to assess the environmental impact of water chlorination, it is necessary to know what chemical compounds are produced and discharged into the receiving waters. To attack this problem, a review of the present state of knowledge of natural water chlorination chemistry was performed, and some experimental work explained the results of previous workers by showing that chlorine losses at very high doses in seawater are simply the result of chlorate and bromate formation which, however, is negligible at normal doses. The most important chlorine-produced oxidants, along with the relevant chemical reactions, were chosen as a basis for a kinetic model of saline water chlorination chemistry. Kinetic data were compiled in a computer program which simultaneously solves 24 differential equations, one for each species modelled. Estimates were made for the unknown rate constants. A purely predictive model was not possible due to the great variability in the organic demand; however, the model is applicable under a broad variety of conditions (except sunlight), and it provides a reasonably good description of a halamine chemistry under environmental conditions.

  18. Tularosa Basin Play Fairway Analysis: Water Chemistry

    SciTech Connect

    Adam Brandt

    2015-12-15

    This shapefile contains 409 well data points on Tularosa Basin Water Chemistry, each of which have a location (UTM), temperature, quartz and Potassium/Magnesium geothermometer; as well as concentrations of chemicals like Mn, Fe, Ba, Sr, Cs, Rb, As, NH4, HCO3, SO4, F, Cl, B, SiO2, Mg, Ca, K, Na, and Li.

  19. Experience with non-fuel-bearing components in LWR (light-water reactor) fuel systems

    SciTech Connect

    Bailey, W.J.; Berting, F.M.

    1990-12-01

    Many non-fuel-bearing components are so closely associated with the spent fuel assemblies that their integrity and behavior must be taken into consideration with the fuel assemblies, when handling spent fuel of planning waste management activities. Presented herein is some of the experience that has been gained over the past two decades from non-fuel-bearing components in light-water reactors (LWRs), both pressurized-water reactors (PWRs) and boiling-water reactors (BWRs). Among the most important of these components are the control rod systems, the absorber and burnable poison rods, and the fuel assembly channels. 15 refs., 5 figs., 2 tabs.

  20. SCC CRACK GROWTH OF COLD-WORKED TYPE 316 SS IN SIMULATED BWR OXIDIZING AND HYDROGEN WATER CHEMISTRY CONDITIONS

    SciTech Connect

    Toloczko, Mychailo B.; Andresen, Peter L.; Bruemmer, Stephen M.

    2007-08-19

    There is considerable interest in the stress corrosion cracking (SCC) susceptibility of austenitic stainless steels in low electrochemical potential (ECP), light water reactor (LWR) environments. Crack growth measurements are presented for ~20% cold-worked, 316 and 316L stainless steels tested in 288°C high-purity water under oxidizing (2000 ppb O2) and hydrogen water chemistry (74-1560 ppb H2) conditions. High SCC crack-growth rates of ~1x10-7 mm/s at constant K were observed in one heat at low ECP, hydrogen water chemistry conditions. Crack morphologies for this heat were mixed intergranular (IG) and transgranular (TG) for all environments but with less TG cracking at the lowest K level tested. Comparisons made to a larger set of data on cold-worked stainless steels indicate that the SCC crack-growth rates from PNNL on this heat are at the high end of test data under low ECP, LWR conditions. Possible reasons for the higher observed SCC propagation rates in the cold-worked 316LSS heat are discussed.

  1. Setting up the water chemistry for thermal water treatment

    NASA Astrophysics Data System (ADS)

    Boglovskii, A. V.; Chernozubov, V. B.; Chernykh, N. E.; Gorbunov, A. V.; Birdin, R. Kh.

    2007-07-01

    Results are presented from the development and setting up of water-chemistry conditions for a thermal water treatment process that allows saline effluents from a boiler house to be eliminated. Peculiarities of reducing scale formation in the evaporator through the use of chalk primer and type PAF-13A antiscale agent are discussed. The results of industrial tests of a thermal water treatment plant are presented that confirm the possibility of producing makeup water for heating networks and steam boilers.

  2. LWR (Light Water Reactor) power plant simulations using the AD10 and AD100 systems

    SciTech Connect

    Wulff, W.; Cheng, H.S.; Chien, C.J.; Jang, J.Y.; Lin, H.C.; Mallen, A.N.; Wang, S.J.; Institute of Nuclear Energy Research, Lung-Tan; Tawian Power Co., Taipei; Brookhaven National Lab., Upton, NY; Institute of Nuclear Energy Research, Lung-Tan )

    1989-01-01

    Boiling (BWR) and Pressurized (PWR) Water Reactor Power Plants are being simulated at BNL with the AD10 and AD100 Peripheral Processor Systems. The AD10 system has been used for BWR simulations since 1984 for safety analyses, emergency training and optimization studies. BWR simulation capabilities have been implemented recently on the AD100 system and PWR simulation capabilities are currently being developed under the auspices of international cooperation. Modeling and simulation methods are presented with emphasis on the simulation of the Nuclear Steam Supply System. Results are presented for BWR simulation and performance characteristics are compared of the AD10 and AD100 systems. It will be shown that the AD100 simulates two times faster than two AD10 processors operating in parallel and that the computing capacity of one AD100 (with FMU processor) is twice as large as that of two AD10 processors. 9 refs., 5 figs., 1 tab.

  3. Categorization of failed and damaged spent LWR (light-water reactor) fuel currently in storage

    SciTech Connect

    Bailey, W.J.

    1987-11-01

    The results of a study that was jointly sponsored by the US Department of Energy and the Electric Power Research Institute are described in this report. The purpose of the study was to (1) estimate the number of failed fuel assemblies and damaged fuel assemblies (i.e., ones that have sustained mechanical or chemical damage but with fuel rod cladding that is not breached) in storage, (2) categorize those fuel assemblies, and (3) prepare this report as an authoritative, illustrated source of information on such fuel. Among the more than 45,975 spent light-water reactor fuel assemblies currently in storage in the United States, it appears that there are nearly 5000 failed or damaged fuel assemblies. 78 refs., 23 figs., 19 tabs.

  4. Water oxidation chemistry of photosystem II

    PubMed Central

    Brudvig, Gary W

    2007-01-01

    Photosystem II (PSII) uses light energy to split water into protons, electrons and O2. In this reaction, nature has solved the difficult chemical problem of efficient four-electron oxidation of water to yield O2 without significant amounts of reactive intermediate species such as superoxide, hydrogen peroxide and hydroxyl radicals. In order to use nature's solution for the design of artificial catalysts that split water, it is important to understand the mechanism of the reaction. The recently published X-ray crystal structures of cyanobacterial PSII complexes provide information on the structure of the Mn and Ca ions, the redox-active tyrosine called YZ and the surrounding amino acids that comprise the O2-evolving complex (OEC). The emerging structure of the OEC provides constraints on the different hypothesized mechanisms for O2 evolution. The water oxidation mechanism of PSII is discussed in the light of biophysical and computational studies, inorganic chemistry and X-ray crystallographic information. PMID:17954436

  5. PWR secondary water chemistry guidelines: Revision 3. Final report

    SciTech Connect

    Lurie, S.; Bucci, G.; Johnson, L.; King, M.; Lamanna, L.; Morgan, E.; Bates, J.; Burns, R.; Eaker, R.; Ward, G.; Linnenbom, V.; Millet, P.; Paine, J.P.; Wood, C.J.; Gatten, T.; Meatheany, D.; Seager, J.; Thompson, R.; Brobst, G.; Connor, W.; Lewis, G.; Shirmer, R.; Gillen, J.; Kerns, M.; Jones, V.; Lappegaard, S.; Sawochka, S.; Smith, F.; Spires, D.; Pagan, S.; Gardner, J.; Polidoroff, T.; Lambert, S.; Dahl, B.; Hundley, F.; Miller, B.; Andersson, P.; Briden, D.; Fellers, B.; Harvey, S.; Polchow, J.; Rootham, M.; Fredrichs, T.; Flint, W.

    1993-05-01

    An effective, state-of-the art secondary water chemistry control program is essential to maximize the availability and operating life of major PWR components. Furthermore, the costs related to maintaining secondary water chemistry will likely be less than the repair or replacement of steam generators or large turbine rotors, with resulting outages taken into account. The revised PWR secondary water chemistry guidelines in this report represent the latest field and laboratory data on steam generator corrosion phenomena. This document supersedes Interim PWR Secondary Water Chemistry Recommendations for IGA/SCC Control (EPRI report TR-101230) as well as PWR Secondary Water Chemistry Guidelines--Revision 2 (NP-6239).

  6. Evaluation of conceptual flowsheets for incorporating Light Water Reactor (LWR) fuel materials in an advanced nuclear fuel cycle

    SciTech Connect

    Bell, J.T.; Burch, W.D.; Collins, E.D.; Forsberg, C.W.; Prince, B.E.; Bond, W.D.; Campbell, D.O.; Delene, J.G.; Mailen, J.C.

    1990-08-01

    A preliminary study by a group of experts at ORNL has generated and evaluated a number of aqueous and non-aqueous flowsheets for recovering transuranium actinides from LWR fuel for use as fuel in an LMR and, at the same time, for transmutation of the wastes to less hazardous materials. The need for proliferation resistance was a consideration in the flowsheets. The current state of development of the flowsheets was evaluated and recommendations for additional study were made. 3 refs., 6 figs.

  7. Acidic deposition and surface water chemistry

    NASA Astrophysics Data System (ADS)

    Church, M. R.

    A pair of back-to-back (morning and afternoon) hydrology sessions, held December 10, 1987, at the AGU Fall Meeting in San Francisco, Calif., covered “Predicting the Effects of Acidic Deposition on Surface Water Chemistry.” The combined sessions included four invited papers, 12 contributed papers, and a panel discussion at its conclusion. The gathering dealt with questions on a variety of aspects of modeling the effects of acidic deposition on surface water chemistry.Contributed papers included discussions on the representation of processes in models as well as limiting assumptions in model application (V. S. Tripathi et al., Oak Ridge National Laboratory, Oak Ridge, Tenn., and E. C. Krug, Illinois State Water Survey, Champaign), along with problems in estimating depositional inputs to catchments and thus inputs to be used in the simulation of catchment response (M. M. Reddy et al., U.S. Geological Survey, Lakewood, Colo.; and E. A. McBean, University of Waterloo, Waterloo, Canada). L. A. Baker et al. (University of Minnesota, Minneapolis) dealt with the problem of modeling seepage lake systems, an exceedingly important portion of the aquatic resources in Florida and parts of the upper U.S. Midwest. J. A. Hau and Y. Eckstein (Kent State University, Kent, Ohio) considered equilibrium modeling of two northern Ohio watersheds that receive very different loads of acidic deposition but are highly similar in other respects.

  8. Montane wetland water chemistry, Uinta Mountains, Utah

    NASA Astrophysics Data System (ADS)

    Severson, K. S.; Matyjasik, M.; Ford, R. L.; Hernandez, M. W.; Welsh, S. B.; Summers, S.; Bartholomew, L. M.

    2009-12-01

    This study attempts to determine the relationship between surface and groundwater chemistry and wetland characteristics within the Reader Lakes watershed, Uinta Mountains. The dominant rock type in the study area is quartz sandstone of the Hades Pass formation, Unita Mountain Group (Middle Proterozoic). Minor amounts of interbedded arkose and illite-bearing shale are also present. Water chemistry data have been collected from more than one hundred locations during the 2008 and 2009 summer seasons. The Reader Creek watershed is approximately 9.8 km long and about 3.5 km wide in the central portion of the basin. Direct precipitation is the primary source of groundwater recharge and the area is typically covered by snow from November until May. Four distinct wetland complexes, designated as the upper, middle, lower and the sloping fen, constitute the major wetland environments in the study area. The chemistry of the melt water from the high-elevation snowfield is affected by weathering of incorporated atmospheric dust and surface rocks. Total dissolved solids in both years were between 7 and 9 mg/L. Major anions include HCO3 (averaging 4.0 mg/L), SO4 (1.3 mg/L), NO3 (0.9 mg/L), Cl (0.8 mg/L), F (0.07 mg/L), PO4 (0.03 mg/L), and Br(0.015 mg/L). Major cations include Na (1.1 mg/L), Ca (1.0 mg/L), K (0.28 mg/L), and Mg (0.15 mg/L). Groundwater concentrations in the lower meadow, as measured in piezomters, are distinctly different, with the following maximum concentrations of anions: HCO3 (36.7 mg/L), SO4 (5.0 mg/L), Cl (3.4 mg/L), NO3 (0.9 mg/L), PO4 (0.28 mg/L), F (0.23 mg/L), Br (0.12 mg/L), and cations: Ca (22 mg/L), Na (4.6 mg/L), Mg (3.4 mg/L), and K (1.8 mg/L)- with a maximum value of 83 mg/L for total dissolved solids. Waters in Reader Creek, the main trunk channel, are typically sodium-potassium and sodium -potassium bicarbonate, with some calcium-bicarbonate, mostly in the middle part of the watershed. Groundwater from springs is sodium-potassium in the upper

  9. Water oxidation chemistry of photosystem II.

    PubMed Central

    Vrettos, John S; Brudvig, Gary W

    2002-01-01

    The O(2)-evolving complex of photosystem II catalyses the light-driven four-electron oxidation of water to dioxygen in photosynthesis. In this article, the steps leading to photosynthetic O(2) evolution are discussed. Emphasis is given to the proton-coupled electron-transfer steps involved in oxidation of the manganese cluster by oxidized tyrosine Z (Y(*)(Z)), the function of Ca(2+) and the mechanism by which water is activated for formation of an O-O bond. Based on a consideration of the biophysical studies of photosystem II and inorganic manganese model chemistry, a mechanism for photosynthetic O(2) evolution is presented in which the O-O bond-forming step occurs via nucleophilic attack on an electron-deficient Mn(V)=O species by a calcium-bound water molecule. The proposed mechanism includes specific roles for the tetranuclear manganese cluster, calcium, chloride, Y(Z) and His190 of the D1 polypeptide. Recent studies of the ion selectivity of the calcium site in the O(2)-evolving complex and of a functional inorganic manganese model system that test key aspects of this mechanism are also discussed. PMID:12437878

  10. Automated Water Chemistry Control at University of Virginia Pools.

    ERIC Educational Resources Information Center

    Krone, Dan

    1997-01-01

    Describes the technologically advanced aquatic and fitness center at the University of Virginia. Discusses the imprecise water chemistry control at the former facility and its intensive monitoring requirements. Details the new chemistry control standards initiated in the new center, which ensure constant chlorine and pH levels. (RJM)

  11. Multiphysics simulations for LWR analysis

    SciTech Connect

    Hamilton, S.; Clarno, K.; Berrill, M.; Evans, T.; Davidson, G.; Lefebvre, R.; Sampath, R.; Hansel, J.; Ragusa, J.; Josey, C.

    2013-07-01

    Accurate prediction of the neutron and temperature distributions within an operating nuclear reactor requires the solution of multiple coupled physics equations. In a light water reactor (LWR), there is a very strong coupling between the power distribution (described by the radiation transport equation) and the temperature and density distributions (described by a thermal diffusion equation in combination with a fluid flow model). This study aims to begin to quantify the impact of such feedback mechanisms as well as identify numerical difficulties associated with such multiphysics problems. A description of the multiphysics model and current solution strategy within the Exnihilo code package for coupling between 3-D radiation transport and 3-D heat transfer is given. Numerical results detailing the effects of varying the nature of the coupling and the impact of mesh refinement for a representative 3x3 pressurized water reactor (PWR) 'mini-assembly' are presented. (authors)

  12. Contribution of water chemistry and fish condition to otolith chemistry: comparisons across salinity environments.

    PubMed

    Izzo, C; Doubleday, Z A; Schultz, A G; Woodcock, S H; Gillanders, B M

    2015-06-01

    This study quantified the per cent contribution of water chemistry to otolith chemistry using enriched stable isotopes of strontium ((86) Sr) and barium ((137) Ba). Euryhaline barramundi Lates calcarifer, were reared in marine (salinity 40), estuarine (salinity 20) and freshwater (salinity 0) under different temperature treatments. To calculate the contribution of water to Sr and Ba in otoliths, enriched isotopes in the tank water and otoliths were quantified and fitted to isotope mixing models. Fulton's K and RNA:DNA were also measured to explore the influence of fish condition on sources of element uptake. Water was the predominant source of otolith Sr (between 65 and 99%) and Ba (between 64 and 89%) in all treatments, but contributions varied with temperature (for Ba), or interactively with temperature and salinity (for Sr). Fish condition indices were affected independently by the experimental rearing conditions, as RNA:DNA differed significantly among salinity treatments and Fulton's K was significantly different between temperature treatments. Regression analyses did not detect relations between fish condition and per cent contribution values. General linear models indicated that contributions from water chemistry to otolith chemistry were primarily influenced by temperature and secondly by fish condition, with a relatively minor influence of salinity. These results further the understanding of factors that affect otolith element uptake, highlighting the necessity to consider the influence of environment and fish condition when interpreting otolith element data to reconstruct the environmental histories of fish. PMID:26033292

  13. Par Pond Fish, Water, and Sediment Chemistry

    SciTech Connect

    Paller, M.H.; Wike, L.D.

    1996-06-01

    The objectives of this report are to describe the Par Pond fish community and the impact of the drawdown and refill on the community, describe contaminant levels in Par Pond fish, sediments, and water and indicate how contaminant concentrations and distributions were affected by the drawdown and refill, and predict possible effects of future water level fluctuations in Par Pond.

  14. Environmental Chemistry: Air and Water Pollution.

    ERIC Educational Resources Information Center

    Stoker, H. Stephen; Seager, Spencer L.

    This is a book about air and water pollution whose chapters cover the topics of air pollution--general considerations, carbon monoxide, oxides of nitrogen, hydrocarbons and photochemical oxidants, sulfur oxides, particulates, temperature inversions and the greenhouse effect; and water pollution--general considerations, mercury, lead, detergents,…

  15. Radiation Damage Assessment in the Reactor Pressure Vessel of the Integral Inherently Safe Light Water Reactor (I2S-LWR)

    NASA Astrophysics Data System (ADS)

    Flaspoehler, Timothy; Petrovic, Bojan

    2016-02-01

    One of the major limiting factors to nuclear reactors lifetime is the radiation-induced material damage in the Reactor Pressure Vessel (RPV). While older reactors were designed assuming a 40-year operating lifetime, new reactor designs are expected to have lifetimes up to 100 years. For safe operation, the integrity of the RPV must be ensured against significant material property changes. In this work, typical neutron damage indicators are calculated in the RPV of the I2S-LWR (Integral Inherently Safe LWR) Power Plant, including DPA (displacements per atom) and fast neutron fluence (>1 MeV and >0.1MeV). I2S-LWR is a PWR of integral design, which means that its wider downcomer provides additional shielding to the vessel. However, its higher core power density and longer lifetime may offset this advantage. In order to accurately represent the neutron environment for RPV damage assessment, a detailed model based on the preliminary design specifications of the I2S-LWR was developed to be used in the MAVRIC (Monaco with Automated Variance Reduction using Importance Calculations) sequence of the Scale6.1 code package. MAVRIC uses the CADIS (Consistent Adjoint-Driven Importance Sampling) methodology to bias a fixed-source MC (Monte Carlo) simulation. To establish the upper limit of a bounding envelope, a flat-source distribution was used. For the low limit, a center-peaked source was generated using the KENO-VI criticality sequence assuming uniform fresh fuel core. Results based on the preliminary I2S-LWR model show that DPA rates and fast fluence rates are conservatively 75% lower than in typical PWRs being operated currently in the US.

  16. Assessment of LWR piping design loading based on plant operating experience

    SciTech Connect

    Svensson, P. O.

    1980-08-01

    The objective of this study has been to: (1) identify current Light Water Reactor (LWR) piping design load parameters, (2) identify significant actual LWR piping loads from plant operating experience, (3) perform a comparison of these two sets of data and determine the significance of any differences, and (4) make an evaluation of the load representation in current LWR piping design practice, in view of plant operating experience with respect to piping behavior and response to loading.

  17. Hydrological Controls on Water Chemistry that Supports Freshwater Mussel Populations

    NASA Astrophysics Data System (ADS)

    Prestegaard, K. L.

    2012-12-01

    Native freshwater mussel species ranges and population sizes have been declining throughout N. America. Due to their sedentary nature, adult mussels are vulnerable to both local habitat changes (often associated with land-use changes, contaminants, and biological invaders) and to climate changes that can alter river flow regimes, bed stability, and water chemistry. The purpose of this study is to examine the relationship between water chemistry and hydrological events in rivers that support native mussel populations. USGS ion concentration and water quality (pH, temperature, conductivity) data were used to calculate saturation indices for aragonite. For some sites, electrical conductivity was highly correlated with calcium and bicarbonate concentrations and could be used to estimate concentrations when ion chemistry was not measured. Continuous water quality data from datasondes could thus be used to evaluate saturation indices for aragonite on a daily basis for 10-15 year periods. For the Delaware River, which has relatively few carbonate rocks in its watershed, tributary aragonite saturation tended to reflect local geological conditions. The lower main stem of the river integrates the water chemistry of the basin and also responds to climatic conditions. The lower Delaware supports aragonite precipitation approximately 50 days per year, with considerable inter-annual variability. During most years, aragonite precipitation could occur during both the spring and late summer periods, but years with heavy spring rains rather than snowmelt shifts aragonite precipitation to late summer periods. In 2011 when several major tropical storms hit the Delaware basin, streamflow was too dilute for aragonite precipitation for most of the summer period. These data suggest that hydrological changes associated with climatic changes may influence the water chemistry and affect the suitability of some rivers as mussel habitat.

  18. The chemistry of salt-affected soils and waters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Knowledge of the chemistry of salt affected soils and waters is necessary for management of irrigation in arid and semi-arid regions. In this chapter we review the origin of salts in the landscape, the major chemical reactions necessary for prediction of the soil solution composition, and the use of...

  19. Long-term trends in precipitation and surface water chemistry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter shows long-term data and trends in precipitation and surface water chemistry for each site. It contains a brief introduction to the topic, and methods of measurements, selection of variables, and their data source. It consists primarily of a large number of figures showing long-term da...

  20. Adaptation of Coccolith Calcification to Sea Water Carbonate Chemistry

    NASA Astrophysics Data System (ADS)

    Ziveri, P.; Langer, G.; Probert, I.; Young, J.

    2008-12-01

    Coccolithophores are major calcifiers and through calcification cause feedbacks to atmospheric CO2 cycling. The formation of CaCO3 in seawater, in fact, causes a shift of the carbonate system towards CO2, which in turn affects atmosphere / ocean CO2 exchange. A change in marine calcification provides a concomitant feedback in organic carbon export and would lead to a change in the drawdown of atmospheric CO2. Coccolithophore culture experiments and field observations showed controversial results regarding the response of calcification to high CO2. The three strains of Emiliania huxleyi (the most abundant living coccolithophore species) tested so far show both increased and decreased calcification at high CO2 levels (lower pH). Living E. huxleyi is known to have a large variability in both size and carbonate content. The hypothesis that we want to test in this work is the importance of adaptation of calcification to the seawater carbonate chemistry where coccolithophores calcify. We selected 4 strains of E. huxleyi maintained at the Roscoff culture collection, collected from different oceanographic settings with different carbon speciation. The selected strains are collected from environments with very different water carbonate chemistry and they have different carbonate mass. They have been experimentally grown at different CO2 levels to test the strain calcification response to sea water carbonate chemistry. . With these experiments we test the importance of the calcification strain adaptation to carbonate chemistry. Size and possibly different responses to carbonate chemistry variations will also be discussed.

  1. Enhanced Accident Tolerant LWR Fuels: Metrics Development

    SciTech Connect

    Shannon Bragg-Sitton; Lori Braase; Rose Montgomery; Chris Stanek; Robert Montgomery; Lance Snead; Larry Ott; Mike Billone

    2013-09-01

    The Department of Energy (DOE) Fuel Cycle Research and Development (FCRD) Advanced Fuels Campaign (AFC) is conducting research and development on enhanced Accident Tolerant Fuels (ATF) for light water reactors (LWRs). This mission emphasizes the development of novel fuel and cladding concepts to replace the current zirconium alloy-uranium dioxide (UO2) fuel system. The overall mission of the ATF research is to develop advanced fuels/cladding with improved performance, reliability and safety characteristics during normal operations and accident conditions, while minimizing waste generation. The initial effort will focus on implementation in operating reactors or reactors with design certifications. To initiate the development of quantitative metrics for ATR, a LWR Enhanced Accident Tolerant Fuels Metrics Development Workshop was held in October 2012 in Germantown, MD. This paper summarizes the outcome of that workshop and the current status of metrics development for LWR ATF.

  2. Control of degradation of spent LWR (light-water reactor) fuel during dry storage in an inert atmosphere

    SciTech Connect

    Cunningham, M.E.; Simonen, E.P.; Allemann, R.T.; Levy, I.S.; Hazelton, R.F.

    1987-10-01

    Dry storage of Zircaloy-clad spent fuel in inert gas (referred to as inerted dry storage or IDS) is being developed as an alternative to water pool storage of spent fuel. The objectives of the activities described in this report are to identify potential Zircaloy degradation mechanisms and evaluate their applicability to cladding breach during IDS, develop models of the dominant Zircaloy degradation mechanisms, and recommend cladding temperature limits during IDS to control Zircaloy degradation. The principal potential Zircaloy cladding breach mechanisms during IDS have been identified as creep rupture, stress corrosion cracking (SCC), and delayed hydride cracking (DHC). Creep rupture is concluded to be the primary cladding breach mechanism during IDS. Deformation and fracture maps based on creep rupture were developed for Zircaloy. These maps were then used as the basis for developing spent fuel cladding temperature limits that would prevent cladding breach during a 40-year IDS period. The probability of cladding breach for spent fuel stored at the temperature limit is less than 0.5% per spent fuel rod. 52 refs., 7 figs., 1 tab.

  3. Uniform corrosion of FeCrAl alloys in LWR coolant environments

    DOE PAGESBeta

    Terrani, K. A.; Pint, B. A.; Kim, Y. -J.; Unocic, K. A.; Yang, Y.; Silva, C. M.; Meyer, III, H. M.; Rebak, R. B.

    2016-06-29

    In this study, the corrosion behavior of commercial and model FeCrAl alloys and type 310 stainless steel was examined by autoclave tests and compared to Zircaloy-4, the reference cladding materials in light water reactors. The corrosion studies were carried out in three distinct water chemistry environments found in pressurized and boiling water reactor primary coolant loop conditions for up to one year. The structure and morphology of the oxides formed on the surface of these alloys was consistent with thermodynamic predictions. Spinel-type oxides were found to be present after hydrogen water chemistry exposures, while the oxygenated water tests resulted inmore » the formation of very thin and protective hematite-type oxides. Unlike the alloys exposed to oxygenated water tests, the alloys tested in hydrogen water chemistry conditions experienced mass loss as a function of time. This mass loss was the result of net sum of mass gain due to parabolic oxidation and mass loss due to dissolution that also exhibits parabolic kinetics. Finally, the maximum thickness loss after one year of LWR water corrosion in the absence of irradiation was ~2 μm, which is inconsequential for a ~300–500 μm thick cladding.« less

  4. Uniform corrosion of FeCrAl alloys in LWR coolant environments

    NASA Astrophysics Data System (ADS)

    Terrani, K. A.; Pint, B. A.; Kim, Y.-J.; Unocic, K. A.; Yang, Y.; Silva, C. M.; Meyer, H. M.; Rebak, R. B.

    2016-10-01

    The corrosion behavior of commercial and model FeCrAl alloys and type 310 stainless steel was examined by autoclave tests and compared to Zircaloy-4, the reference cladding materials in light water reactors. The corrosion studies were carried out in three distinct water chemistry environments found in pressurized and boiling water reactor primary coolant loop conditions for up to one year. The structure and morphology of the oxides formed on the surface of these alloys was consistent with thermodynamic predictions. Spinel-type oxides were found to be present after hydrogen water chemistry exposures, while the oxygenated water tests resulted in the formation of very thin and protective hematite-type oxides. Unlike the alloys exposed to oxygenated water tests, the alloys tested in hydrogen water chemistry conditions experienced mass loss as a function of time. This mass loss was the result of net sum of mass gain due to parabolic oxidation and mass loss due to dissolution that also exhibits parabolic kinetics. The maximum thickness loss after one year of LWR water corrosion in the absence of irradiation was ∼2 μm, which is inconsequential for a ∼300-500 μm thick cladding.

  5. Radiation chemistry in ammonia-water ices

    SciTech Connect

    Loeffler, M. J.; Raut, U.; Baragiola, R. A.

    2010-02-07

    We studied the effects of 100 keV proton irradiation on films of ammonia-water mixtures between 20 and 120 K. Irradiation destroys ammonia, leading to the formation and trapping of H{sub 2}, N{sub 2}, NO, and N{sub 2}O, the formation of cavities containing radiolytic gases, and ejection of molecules by sputtering. Using infrared spectroscopy, we show that at all temperatures the destruction of ammonia is substantial, but at higher temperatures (120 K), it is nearly complete ({approx}97% destroyed) after a fluence of 10{sup 16} ions/cm{sup 2}. Using mass spectroscopy and microbalance gravimetry, we measure the sputtering yield of our sample and the main components of the sputtered flux. We find that the sputtering yield depends on fluence. At low temperatures, the yield is very low initially and increases quadratically with fluence, while at 120 K the yield is constant and higher initially. The increase in the sputtering yield with fluence is explained by the formation and trapping of the ammonia decay products, N{sub 2} and H{sub 2}, which are seen to be ejected from the ice at all temperatures.

  6. Radiation Chemistry in Ammonia-Water Ices

    NASA Technical Reports Server (NTRS)

    Loeffler, M. J.; Raut, U.; Baragiola, R. A.

    2010-01-01

    We studied the effects of 100 keV proton irradiation on films of ammonia-water mixtures between 20 and 120 K. Irradiation destroys ammonia, leading to the formation and trapping of H2, N2 NO, and N2O, the formation of cavities containing radiolytic gases, and ejection of molecules by sputtering. Using infrared spectroscopy, we show that at all temperatures the destruction of ammonia is substantial, but at higher temperatures (120 K), it is nearly complete (approximately 97% destroyed) after a fluence of 10(exp 16) ions per square centimeter. Using mass spectroscopy and microbalance gravimetry, we measure the sputtering yield of our sample and the main components of the sputtered flux. We find that the sputtering yield depends on fluence. At low temperatures, the yield is very low initially and increases quadratically with fluence, while at 120 K the yield is constant and higher initially. The increase in the sputtering yield with fluence is explained by the formation and trapping of the ammonia decay products, N2 and H2 which are seen to be ejected from the ice at all temperatures.

  7. Ground-water and water-chemistry data for the upper Deschutes Basin, Oregon

    USGS Publications Warehouse

    Caldwell, Rodney R.; Truini, Margot

    1997-01-01

    This report presents ground-water data collected and compiled as part of a study of the ground-water resources of the upper Deschutes Basin, Oregon. Data in this report include tabulated information and a location map for more than 1,500 field-located water wells, hydrographs showing water-level fluctuations over various time periods for 102 of the wells, and water-chemistry analyses from 26 wells, 7 springs, and 5 surface-water sites.

  8. Physical chemistry: Water's response to the fear of water

    NASA Astrophysics Data System (ADS)

    Bakker, Huib J.

    2012-11-01

    Spectroscopic analysis reveals that, at low temperatures, hydrophobic molecules dissolved in water strengthen the hydrogen bonding between nearby water molecules. But at high temperatures, the reverse can be true. See Letter p.582

  9. The Role of Water Chemistry in Marine Aquarium Design: A Model System for a General Chemistry Class

    NASA Astrophysics Data System (ADS)

    Keaffaber, Jeffrey J.; Palma, Ramiro; Williams, Kathryn R.

    2008-02-01

    Water chemistry is central to aquarium design, and it provides many potential applications for discussion in undergraduate chemistry and engineering courses. Marine aquaria and their life support systems feature many chemical processes. A life support system consists of the entire recirculation system, as well as the habitat tank and all ancillary water treatment processes. Many fundamental concepts learned in general chemistry, for example, unit conversion, solution concentrations, stoichiometry, redox reactions, and acid-base chemistry are all key to understanding the life support system. This article uses a hypothetical tank to house ocean sunfish as a model to show students the calculations and other considerations that are needed when designing a marine aquarium.

  10. Chemistry of Stream Sediments and Surface Waters in New England

    USGS Publications Warehouse

    Robinson, Gilpin R., Jr.; Kapo, Katherine E.; Grossman, Jeffrey N.

    2004-01-01

    Summary -- This online publication portrays regional data for pH, alkalinity, and specific conductance for stream waters and a multi-element geochemical dataset for stream sediments collected in the New England states of Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. A series of interpolation grid maps portray the chemistry of the stream waters and sediments in relation to bedrock geology, lithology, drainage basins, and urban areas. A series of box plots portray the statistical variation of the chemical data grouped by lithology and other features.

  11. MCNP LWR Core Generator

    SciTech Connect

    Fischer, Noah A.

    2012-08-14

    The reactor core input generator allows for MCNP input files to be tailored to design specifications and generated in seconds. Full reactor models can now easily be created by specifying a small set of parameters and generating an MCNP input for a full reactor core. Axial zoning of the core will allow for density variation in the fuel and moderator, with pin-by-pin fidelity, so that BWR cores can more accurately be modeled. LWR core work in progress: (1) Reflectivity option for specifying 1/4, 1/2, or full core simulation; (2) Axial zoning for moderator densities that vary with height; (3) Generating multiple types of assemblies for different fuel enrichments; and (4) Parameters for specifying BWR box walls. Fuel pin work in progress: (1) Radial and azimuthal zoning for generating further unique materials in fuel rods; (2) Options for specifying different types of fuel for MOX or multiple burn assemblies; (3) Additional options for replacing fuel rods with burnable poison rods; and (4) Control rod/blade modeling.

  12. Guidelines and techniques for obtaining water samples that accurately represent the water chemistry of an aquifer

    USGS Publications Warehouse

    Claassen, Hans C.

    1982-01-01

    Obtaining ground-water samples that accurately represent the water chemistry of an aquifer is a complex task. Before a ground-water sampling program can be started, an understanding of the kind of chemical data needed and the potential changes in water chemistry resulting from various drilling, well-completion, and sampling techniques is needed. This report provides a basis for such an evaluation and permits a choice of techniques that will result in obtaining the best possible data for the time and money allocated.

  13. Water Formation and Oxygen Chemistry on Dust Grains

    NASA Astrophysics Data System (ADS)

    Vidali, Gianfranco; He, Jiao

    Water plays an important role in space. As ice on cold dust grains, it provides the medium for a rich chemistry; in the gas-phase, it gives information on the particular environment it is in. It is understood that the formation of water occurs both in the gas-phase and on grains. While the importance of water formation on dust grain surfaces has been recognized for a long time (1) , it is only recently that laboratory investigations have been undertaken to characterize the network of reactions (2) . Closely connected to this work on water formation, is the study of oxygen chemistry on dust grains. Of particular importance is the characterization of the energetics of adsorption, diffusion and desorption of oxygen-containing molecules. I will present data from recent experiments on the interaction of oxygen and hydroxyls with silicate surfaces and on the formation of water on warm (T>30K) amorphous silicates. Such results provide new values to parameters used in simulation codes of the chemical evolution of interstellar space environments. 1. A.G.G.M Tielens & W. Hagen, Astron. & Astrophys. 114, 245 (1982). 2. G. Vidali, J. Low Temp. Phys. 170,1 (2013). This work is supported by the NSF, Astronomy & Astrophysics Division (Grants No. 0908108 and 1311958), and NASA (Grant No. NNX12AF38G). We thank Dr. J.Brucato of the Astrophysical Observatory of Arcetri for providing the samples used in these experiments.

  14. Effect of Revised Nebular Water Distribution on Nebular Chemistry

    NASA Astrophysics Data System (ADS)

    Cyr, K. E.; Sears, W. D.; Sharp, C.; Lunine, J. I.

    1997-07-01

    The distribution of water in the solar nebula is important both because water is extremely abundant and because it condenses out at 5 AU, allowing ice and vapor to affect the chemistry of the nebula and forming solar system bodies. In one previous examination of the distribution of nebular water, (Stevenson, D. J. and Lunine, J. I. 1988, Icarus 75, 146), vapor is transported across the condensation front by eddy diffusion and rapidly condenses out as ice. The ice is assumed to suffer little effect from gas drag or other transport processes and so remains in the condensation zone. The model predicts that the inner 5 AU of the nebula becomes severely depleted in water vapor in as little as 10(5) yr. However, in recent work (Cyr, K. E. et al. 1997, Icarus submitted) we found that gas drag effects in Stevenson and Lunine (1988) had been underestimated and that ice particles could drift back inward of 5 AU significant distances and sublimate, re-injecting the nebula with water vapor. Our expanded water transport model which incorporated both diffusion and drift processes still predicts an overall depletion in water vapor, but with a zone of local vapor enhancement on the order of 20-100% from 1-2 AU, which gradually drops off out to 5 AU. Thus, unlike Steveson and Lunine, we find a radial dependence to the water vapor depletion pattern and thus to the reducing nature and C/O ratio in the inner nebula. We will consider the overall effect of the radial dependence of water depletion on nebular chemistry, using a chemical equilibrium code that computes abundances of nebular elements and major molecular C, N, S species. In particular, we will examine changes in local [CO]/[CH4] and [N2]/[NH3] ratios due to the radially dependent decrease in oxygen fugacity, and the implications for forming solar system bodies.

  15. A robust model for pore-water chemistry of clayrock

    NASA Astrophysics Data System (ADS)

    Gaucher, E. C.; Tournassat, C.; Pearson, F. J.; Blanc, P.; Crouzet, C.; Lerouge, C.; Altmann, S.

    2009-11-01

    The chemistry of pore water is an important property of clayrocks being considered as host rocks for long-term storage of radioactive waste. It may be difficult, if not impossible, to obtain water samples for chemical analysis from such rocks because of their low hydraulic conductivity. This paper presents an approach for calculating the pore-water compositions of clayrocks from laboratory-measured properties of core samples, including their leachable Cl and SO 4 concentrations and analysed exchangeable cations, and from mineral and cation exchange equilibria based on the formation mineralogy. New core sampling and analysis procedures are presented that reduce or quantify side reactions such as sample oxidation (e.g. pyrite) and soluble mineral dissolution (celestite, SrSO 4) that affect measured SO 4 concentrations and exchangeable cation distributions. The model considers phase equilibria only with minerals that are observed in the formation including the principal clay phases. The model has been used to calculate the composition of mobile pore water in the Callovo-Oxfordian clayrock and validated against measurements of water chemistry made in an underground research laboratory in that formation. The model reproduces the measured, in situ pore-water composition without any estimated parameters. All required parameters can be obtained from core sample analysis. We highlight the need to consider only those mineral phases which can be shown to be in equilibrium with contacting pore water. The consequence of this is that some conceptual models available in the literature appear not to be appropriate for modelling clayrocks, particularly those considering high temperature and/or high pressure detrital phases as chemical buffers of pore water. The robustness of our model with respect to uncertainties in the log K values of clay phases is also demonstrated. Large uncertainties in log K values for clay minerals have relatively small effects on modelled pore-water

  16. Hadronic chemistry applied to hydrogen and water molecules

    NASA Astrophysics Data System (ADS)

    Tangde, Vijay M.

    2012-09-01

    The decades of research of R M Santilli resulted into the formulation of iso-, geno- and hyper- mathematics [1, 2] that helped in understanding numerous diversified problems and removing inadequacies in most of the established and celebrated theories of 20th century physics and chemistry, for example, the theories of relativity, quantum mechanics (chemistry), astrophysics, particle physics, and so on. This involves the isotopic, genotopic, etc. lifting of Lie algebra that generated Lie admissible mathematics to properly describe irreversible processes. The studies on Hadronic m Mechanics based on Santilli's mathematics for the first time has removed the very fundamental limitations of quantum chemistry [3, 4] [2, 3, 4]. Herein, we review a Santilli-Shillady model[3, 4, 5] of hydrogen and water molecules characterized by a bond at short distances of the two valance electrons into a singlet quasi-particle state called isoelectronium for hydrogen molecule and two isoelctronia (one per H-O dimer) in case of water molecule. We especially emphasis on: the numerically exact representation of binding energies from unadulterated first axiomatic principle, the reduction of the hydrogen molecule to a restricted three body problem that admits exact analytic solutions and the reduction of computer time by at least a factor of 1000 folds due to a much faster convergent series.

  17. The Chemistry and Excitation of Water in Molecular Clouds

    NASA Technical Reports Server (NTRS)

    Hollenbach, David

    2003-01-01

    We model the chemistry and thermal balance of opaque molecular clouds exposed to an external flux of ultraviolet photons. We include the processes of gas phase and grain surface chemical reactions; in particular we examine closely the freezing of atoms and molecules onto grain surfaces and the desorption of molecules from grain surfaces as a function of depth into a molecular cloud. We find that on the surface of a molecular cloud the gas phase water abundances are low because of photodissociation, and the grain phase water (ice) abundance is low because of photodesorption of water from the grain surfaces. Deeper into the cloud, at A(sub v) less than or approximately 2-8 depending on the strength of the external ultraviolet flux, the gas phase water abundance increases with depth as the photodissociation rates decline due to dust attenuation of the ultraviolet field. However, beyond A(sub v) less than or approximately 2-8 the gas phase water abundance declines because the water freezes as water ice on the grains, and photodesorption is no longer effective in clearing the ice. A peak water abundance of about 10(exp -6) to 10(exp -7) occurs at about A(sub v) approximately 2-8, relatively independent of the gas density and the ultraviolet field. We show that such a model matches very closely the observations of the Submillimeter Wave Astronomical Satellite (SWAS), a NASA Small Explorer Mission. The model elucidates several mechanisms that have been recently invoked to understand gas phase chemistry in clouds, including-the freeze-out of molecules onto grain surface, the desorption of these molecules from the surfaces, and the abundance gradients of molecules as functions of depth into molecular clouds.

  18. Chemistry of trace elements in coalbed methane product water.

    PubMed

    McBeth, Ian; Reddy, Katta J; Skinner, Quentin D

    2003-02-01

    Extraction of methane (natural gas) from coal deposits is facilitated by pumping of aquifer water. Coalbed methane (CBM) product water, produced from pumping ground water, is discharged into associated unlined holding ponds. The objective of this study was to examine the chemistry of trace elements in CBM product water at discharge points and in associated holding ponds across the Powder River Basin, Wyoming. Product water samples from discharge points and associated holding ponds were collected from the Cheyenne River (CHR), Belle Fourche River (BFR), and Little Powder River (LPR) watersheds during the summers of 1999 and 2000. Samples were analyzed for pH, Al (aluminum), As (arsenic), B (boron), Ba (barium), Cr (chromium), Cu (copper), F (fluoride), Fe (iron), Mn (manganese), Mo (molybdenum), Se (selenium), and Zn (zinc). Chemistry of trace element concentrations were modeled with the MINTEQA2 geochemical equilibrium model. Results of this study show that pH of product water for three watersheds increased in holding ponds. For example the pH of CBM product water increased from 7.21 to 8.26 for LPR watershed. Among three watersheds, the CBM product water exhibited relatively less change in trace element concentrations in CHR watershed holding ponds. Concentration of dissolved Al, Fe, As, Se, and F in product water increased in BFR watershed holding ponds. For example, concentration of dissolved Fe increased from 113 to 135 microg/L. Boron, Cu, and Zn concentrations of product water did not change in BFR watershed holding ponds. However, concentration of dissolved Ba, Mn, and Cr in product water decreased in BFR watershed holding ponds. For instance, Ba and Cr concentrations decreased from 445 to 386 microg/L and from 43.6 to 25.1 microg/L, respectively. In the LPR watershed, Al, Fe, As, Se, and F concentrations of product water increased substantially in holding ponds. For example, Fe concentration increased from 192 to 312 microg/L. However, concentration of

  19. Size resolved fog water chemistry and its atmospheric implications

    NASA Astrophysics Data System (ADS)

    Chakraborty, Abhishek; Gupta, Tarun; Tripathi, Sachchida; Ervens, Barbara; Bhattu, Deepika

    2015-04-01

    Fog is a natural meteorological phenomenon that occurs throughout the world. It usually contains substantial quantity of liquid water and results in severe visibility reduction leading to disruption of normal life. Fog is generally seen as a natural cleansing agent but it also has the potential to form Secondary Organic Aerosol (SOA) via aqueous processing of ambient aerosols. Size- resolved fog water chemistry for inorganics were reported in previous studies but processing of organics inside the fog water and quantification of aqSOA remained a challenge. To assess the organics processing via fog aqueous processing, size resolved fog water samples were collected in two consecutive winter seasons (2012-13, 2013-14) at Kanpur, a heavily polluted urban area of India. Caltech 3 stage fog collector was used to collect the fog droplets in 3 size fraction; coarse (droplet diameter > 22 µm), medium (22> droplet diameter >16 µm) and fine (16> droplet diameter >4 µm). Collected samples were atomized into various instruments such as Aerosol Mass Spectrometer (AMS), Cloud Condensation Nucleus Counter (CCNc), Total Organic Carbon (TOC) and a thermo denuder (TD) for the physico-chemical characterization of soluble constituents. Fine droplets are found to be more enriched with different aerosol species and interestingly contain more aged and less volatile organics compared to other coarser sizes. Organics inside fine droplets have an average O/C = 0.87 compared to O/C of 0.67 and 0.74 of coarse and medium droplets. Metal chemistry and higher residence time of fine droplets are seemed to be the two most likely reasons for this outcome from as the results of a comprehensive modeling carried out on the observed data indicate. CCN activities of the aerosols from fine droplets are also much higher than that of coarse or medium droplets. Fine droplets also contain light absorbing material as was obvious from their 'yellowish' solution. Source apportionment of fog water organics via

  20. The Role of Water Chemistry in Marine Aquarium Design: A Model System for a General Chemistry Class

    ERIC Educational Resources Information Center

    Keaffaber, Jeffrey J.; Palma, Ramiro; Williams, Kathryn R.

    2008-01-01

    Water chemistry is central to aquarium design, and it provides many potential applications for discussion in undergraduate chemistry and engineering courses. Marine aquaria and their life support systems feature many chemical processes. A life support system consists of the entire recirculation system, as well as the habitat tank and all ancillary…

  1. The Effect of Improved Water Chemistry on Corrosion Cracking of BWR Piping: Workshop Proceedings

    SciTech Connect

    1989-12-01

    Implementation of the EPRI BWR water chemistry guidelines by utilities has significantly improved the chemistry of BWRs. Water chemistry improvements extend the service life of BWR piping and provide a technical justification for increased intervals of in-service inspections of BWR piping.

  2. Multiscale Drivers of Water Chemistry of Boreal Lakes and Streams

    PubMed Central

    Johnson, Richard K.

    2006-01-01

    The variability in surface water chemistry within and between aquatic ecosystems is regulated by many factors operating at several spatial and temporal scales. The importance of geographic, regional-, and local-scale factors as drivers of the natural variability of three water chemistry variables representing buffering capacity and the importance of weathering (acid neutralizing capacity, ANC), nutrient concentration (total phosphorus, TP), and importance of allochthonous inputs (total organic carbon, TOC) were studied in boreal streams and lakes using a method of variance decomposition. Partial redundancy analysis (pRDA) of ANC, TP, and TOC and 38 environmental variables in 361 lakes and 390 streams showed the importance of the interaction between geographic position and regional-scale variables. Geographic position and regional-scale factors combined explained 15.3% (streams) and 10.6% (lakes) of the variation in ANC, TP, and TOC. The unique variance explained by geographic, regional, and local-scale variables alone was <10%. The largest amount of variance was explained by the pure effect of regional-scale variables (9.9% for streams and 7.8% for lakes), followed by local-scale variables (2.9% and 5.8%) and geographic position (1.8% and 3.7%). The combined effect of geographic position, regional-, and local-scale variables accounted for between 30.3% (lakes) and 39.9% (streams) of the variance in surface water chemistry. These findings lend support to the conjecture that lakes and streams are intimately linked to their catchments and have important implications regarding conservation and restoration (management) endeavors. PMID:16955233

  3. Influence of surface structure and chemistry on water droplet splashing.

    PubMed

    Koch, Kerstin; Grichnik, Roland

    2016-08-01

    Water droplet splashing and aerosolization play a role in human hygiene and health systems as well as in crop culturing. Prevention or reduction of splashing can prevent transmission of diseases between animals and plants and keep technical systems such as pipe or bottling systems free of contamination. This study demonstrates to what extent the surface chemistry and structures influence the water droplet splashing behaviour. Smooth surfaces and structured replicas of Calathea zebrina (Sims) Lindl. leaves were produced. Modification of their wettability was done by coating with hydrophobizing and hydrophilizing agents. Their wetting was characterized by contact angle measurement and splashing behaviour was observed with a high-speed video camera. Hydrophobic and superhydrophilic surfaces generally showed fewer tendencies to splash than hydrophobic ones. Structuring amplified the underlying behaviour of the surface chemistries, increasing hydrophobic surfaces' tendency to splash and decreasing splash on hydrophilic surfaces by quickly transporting water off the impact point by capillary forces. The non-porous surface structures found in C. zebrina could easily be applied to technical products such as plastic foils or mats and coated with hydrophilizing agents to suppress splash in areas of increased hygiene requirements or wherever pooling of liquids is not desirable.This article is part of the themed issue 'Bioinspired hierarchically structured surfaces for green science'. PMID:27354737

  4. Acid-base chemistry of frustrated water at protein interfaces.

    PubMed

    Fernández, Ariel

    2016-01-01

    Water molecules at a protein interface are often frustrated in hydrogen-bonding opportunities due to subnanoscale confinement. As shown, this condition makes them behave as a general base that may titrate side-chain ammonium and guanidinium cations. Frustration-based chemistry is captured by a quantum mechanical treatment of proton transference and shown to remove same-charge uncompensated anticontacts at the interface found in the crystallographic record and in other spectroscopic information on the aqueous interface. Such observations are untenable within classical arguments, as hydronium is a stronger acid than ammonium or guanidinium. Frustration enables a directed Grotthuss mechanism for proton transference stabilizing same-charge anticontacts. PMID:26762189

  5. Assessing background ground water chemistry beneath a new unsewered subdivision

    USGS Publications Warehouse

    Wilcox, J.D.; Bradbury, K.R.; Thomas, C.L.; Bahr, J.M.

    2005-01-01

    Previous site-specific studies designed to assess the impacts of unsewered subdivisions on ground water quality have relied on upgradient monitoring wells or very limited background data to characterize conditions prior to development. In this study, an extensive monitoring program was designed to document ground water conditions prior to construction of a rural subdivision in south-central Wisconsin. Previous agricultural land use has impacted ground water quality; concentrations of chloride, nitrate-nitrogen, and atrazine ranged from below the level of detection to 296 mg/L, 36 mg/L, and 0.8 ??g/L, respectively, and were highly variable from well to well and through time. Seasonal variations in recharge, surface topography, aquifer heterogeneities, surficial loading patterns, and well casing depth explain observed variations in ground water chemistry. This variability would not have been detected if background conditions were determined from only a few monitoring wells or inferred from wells located upgradient of the subdivision site. This project demonstrates the importance of characterizing both ground water quality and chemical variability prior to land-use change to detect any changes once homes are constructed. Copyright ?? 2005 National Ground Water Association.

  6. Surface Chemistry and Water Dispersability of Carbon Black Materials

    SciTech Connect

    Contescu, Cristian I; Baker, Frederick S; Burchell, Timothy D

    2006-01-01

    Formulation of water-stable carbon black dispersions is a double-sided task, which requires selection of a proper dispersing agents and matching it with the properties of a specific carbon black. Among other properties that affect water dispersability of carbon blacks (particle size, surface area, and aggregate structure), surface chemistry plays a prime-order role. We have characterized physical and chemical properties of several carbon black materials, and correlated them with the stability of dispersions formed with ionic and non-ionic surfactants. In particular, chemical characterization of surface functional groups on carbon blacks based on potentiometric titration measurements (pKa spectra) provided a comprehensive picture of pH effects on dispersion stability. The results obtained were complemented by information from physical characterization methods, such as XPS and FTIR. The selection of a suitable dispersing agent able to withstand large pH variations will be discussed.

  7. Water chemistry of hot waters of Umut geothermal field (SW Turkey)

    NASA Astrophysics Data System (ADS)

    Avşar, Özgür; Türe, Orkun

    2014-05-01

    Umut geothermal field is located on Menderes graben which is one of the most active geothermal regions of Turkey. In order to delineate the chemistry of the waters of Umut geothermal field, fourteen samples were taken from four wells and ten from hot springs. Discharge temperatures of the waters range from 20 to 120 °C. According to the results of chemical analyses, the waters are Na+K - HCO3 type. Cation geothermometer calculations revealed a reservoir temperature greater than 200 °C for Umut geothermal field waters. Stable isotope analyses results indicates that the waters are meteoric in origin.

  8. Introduction to Chemistry for Water and Wastewater Treatment Plant Operators. Water and Wastewater Training Program.

    ERIC Educational Resources Information Center

    South Dakota Dept. of Environmental Protection, Pierre.

    Presented are basic concepts of chemistry necessary for operators who manage drinking water treatment plants and wastewater facilities. It includes discussions of chemical terms and concepts, laboratory procedures for basic analyses of interest to operators, and discussions of appropriate chemical calculations. Exercises are included and answer…

  9. New Mechanistic Pathways for Criegee-Water Chemistry at the Air/Water Interface.

    PubMed

    Zhu, Chongqin; Kumar, Manoj; Zhong, Jie; Li, Lei; Francisco, Joseph S; Zeng, Xiao Cheng

    2016-09-01

    Understanding Criegee chemistry has become one of central topics in atmospheric research recently. The reaction of Criegee intermediates with gas-phase water clusters has been widely viewed as a key Criegee reaction in the troposphere. However, the effect of aerosols or clouds on Criegee chemistry has received little attention. In this work, we have investigated the reaction between the smallest Criegee intermediate, CH2OO, and water clusters in the gas phase, as well as at the air/water surface using ab initio quantum chemical calculations and adaptive buffered force quantum mechanics/molecular mechanics (QM/MM) dynamics simulations. Our simulation results show that the typical time scale for the reaction of CH2OO with water at the air/water interface is on the order of a few picoseconds, 2-3 orders of magnitude shorter than that in the gas phase. Importantly, the adbf-QM/MM dynamics simulations suggest several reaction pathways for the CH2OO + water reaction at the air/water interface, including the loop-structure-mediated mechanism and the stepwise mechanism. Contrary to the conventional gas-phase CH2OO reaction, the loop-structure is not a prerequisite for the stepwise mechanism. For the latter, a water molecule and the CH2OO at the air/water interface, upon their interaction, can result in the formation of (H3O)(+) and (OH)CH2(OO)(-). Thereafter, a hydrogen bond can be formed between (H3O)(+) and the terminal oxygen atom of (OH)CH2(OO)(-), leading to direct proton transfer and the formation of α-hydroxy methylperoxide, HOCH2OOH. The mechanistic insights obtained from this simulation study should motivate future experimental studies of the effect of water clouds on Criegee chemistry. PMID:27509207

  10. LWR improvement in EUV resist process

    NASA Astrophysics Data System (ADS)

    Koh, Chawon; Kim, Hyun-Woo; Kim, Sumin; Na, Hai-Sub; Park, Chang-Min; Park, Cheolhong; Cho, Kyoung-Yong

    2011-04-01

    Extreme ultraviolet lithography (EUVL) is the most effective way to print sub-30 nm features. The roughness of both the resist sidewall (line width roughness [LWR]) and resist top must be overcome soon for EUVL to be implemented. Currently, LWR can vary by about 1 nm according to the recipe used. We have characterized two promising techniques to improve LWR, an EUV rinse/TBAH process and an implant process, and demonstrated their efficacy. After cleaning inspection (ACI), LWR was improved with both the rinse and implant processes. After development inspection (ADI), LWR improved (0.12 nm, 2.4%) and ACI LWR improved (0.1 nm, 2.0% improvement) after using the EUV rinse process. ADI and ACI LWR improvement (0.45 nm, 9.1%, and 0.3 nm, 6.9%, respectively) was demonstrated with the EUV rinse/TBAH process. ADI LWR improvement (0.5 nm, 8.1%) and ACI LWR improvement (-0.5 nm, -16.9%) were characterized with the implant process. Critical dimension (CD) showed similar changes through pitch after the EUV rinse or TBAH process, but the degree of change depended on the initial pattern size giving CD difference of 2 nm between 30 nm HP and 50 nm HP after the implant process. For this technique, the dependence of CD change on pattern size must be minimized. Further extensive studies with rinse or implant are strongly encouraged for continued LWR improvement and real process implementation in EUVL. Demonstrating <2.2 nm LWR after pattern transfer is important in EUVL and needs to be pursued using various technical approaches. Initial resist LWR is important in assessing LWR improvements with additional process techniques. An initial EUV LWR < ~5.0 nm is required to properly assess the validity of the technique. Further study is required to improve ADI LWR and maintain better LWR after etch with advanced EUV rinse materials. Defects also need to be confirmed following the EUV rinse and TBAH developer. Further developing the implant process should focus on LWR improvement at low

  11. Uranium mononitride as a potential commercial LWR fuel

    SciTech Connect

    Xu, P.; Yan, J.; Lahoda, E. J.; Ray, S.

    2012-07-01

    This paper evaluated uranium mononitride (UN) as a potential replacement for 5% enriched UO{sub 2} fuel in Generation III and III+ commercial light water reactors (LWRs). Significant improvement in LWR performance depends on developing and implementing changes in the nuclear fuel used in these reactors. Compared to UO{sub 2}, UN offers several advantages such as higher uranium loading and better thermal conductivity. In this paper, the thermal safety margin of UN was evaluated at both normal and accident conditions using a readily available coupled CFD model developed for the US DOE CASL program. One of the prime technical challenges in utilization of UN as LWR fuel is the water compatibility because pure phase UN is not stable in water at 350 deg. C. The water corrosion resistance of UN and the corrosion mechanism were reviewed and mitigation methods were proposed. (authors)

  12. Technical basis for hydrogen-water chemistry: Laboratory studies of water chemistry effects on SCC (stress-corrosion-cracking)

    SciTech Connect

    Kassner, T.F.; Ruther, W.E.; Soppet, W.K.

    1986-10-01

    The influence of different impurities, viz., oxyacids and several chloride salts, on the stress-corrosion-cracking (SCC) of sensitized Type 304 stainless steel (SS) was investigated in constant-extension-rate-tensile (CERT) tests in 289/sup 0/C water at a low dissolved-oxygen concentration (<5 ppB). Cyclic loading experiments on fatigue precracked fracture-mechanics-type specimens of this material and Type 316NG were also performed at 289/sup 0/C in low-oxygen environments with and without sulfate at low concentrations. In these experiments, the crack growth behavior of the materials was correlated with the type and concentration of the impurities and the electrochemical potentials of Type 304 SS and platinum electrodes in the simulated hydrogen-water chemistry environments. The information suggests that better characterization of water quality, through measurement of the concentrations of individual species (SO/sub 4//sup 2 -/, NO/sub 3//sup -/, Cu/sup 2 +/, etc.) coupled with measurements of the corrosion and redox potentials at high temperatures will provide a viable means to monitor and ultimately improve the performance of BWR system materials.

  13. Photosynthetic water oxidation: insights from manganese model chemistry.

    PubMed

    Young, Karin J; Brennan, Bradley J; Tagore, Ranitendranath; Brudvig, Gary W

    2015-03-17

    Catalysts for light-driven water oxidation are a critical component for development of solar fuels technology. The multielectron redox chemistry required for this process has been successfully deployed on a global scale in natural photosynthesis by green plants and cyanobacteria using photosystem II (PSII). PSII employs a conserved, cuboidal Mn4CaOX cluster called the O2-evolving complex (OEC) that offers inspiration for artificial O2-evolution catalysts. In this Account, we describe our work on manganese model chemistry relevant to PSII, particularly the functional model [Mn(III/IV)2(terpy)2(μ-O)2(OH2)2](NO3)3 complex (terpy = 2,2';6',2″-terpyridine), a mixed-valent di-μ-oxo Mn dimer with two terminal aqua ligands. In the presence of oxo-donor oxidants such as HSO5(-), this complex evolves O2 by two pathways, one of which incorporates solvent water in an O-O bond-forming reaction. Deactivation pathways of this catalyst include comproportionation to form an inactive Mn(IV)Mn(IV) dimer and also degradation to MnO2, a consequence of ligand loss when the oxidation state of the complex is reduced to labile Mn(II) upon release of O2. The catalyst's versatility has been shown by its continued catalytic activity after direct binding to the semiconductor titanium dioxide. In addition, after binding to the surface of TiO2 via a chromophoric linker, the catalyst can be oxidized by a photoinduced electron-transfer mechanism, mimicking the natural PSII process. Model oxomanganese complexes have also aided in interpreting biophysical and computational studies on PSII. In particular, the μ-oxo exchange rates of the Mn-terpy dimer have been instrumental in establishing that the time scale for μ-oxo exchange of high-valent oxomanganese complexes with terminal water ligands is slower than O2 evolution in the natural photosynthetic system. Furthermore, computational studies on the Mn-terpy dimer and the OEC point to similar Mn(IV)-oxyl intermediates in the O-O bond

  14. Thermal expansion coefficient of steels used in LWR vessels

    NASA Astrophysics Data System (ADS)

    Daw, J. E.; Rempe, J. L.; Knudson, D. L.; Crepeau, J. C.

    2008-05-01

    Because of the impact that melt relocation and vessel failure have on subsequent progression and associated consequences of a light water reactor (LWR) accident, it is important to accurately predict the heat-up and relocation of materials within the reactor vessel and heat transfer to and from the reactor vessel. Accurate predictions of such heat transfer phenomena require high temperature thermal properties. However, a review of vessel and structural steel material properties in severe accident analysis codes reveals that the required high temperature material properties are extrapolated with little, if any, data above 700 °C. To reduce uncertainties in predictions relying upon this extrapolated high temperature data, new thermal expansion data were obtained using pushrod dilatometry techniques for two steels used in LWR vessels: SA 533 Grade B, Class 1 (SA533B1) low alloy steel, which is used to fabricate most US LWR reactor vessels; and Type 304 stainless steel (SS304), which is used in LWR vessel piping, penetration tubes, and internal structures. This paper summarizes the new data and compares it to existing, lower temperature data in the literature.

  15. High temperature thermal properties for metals used in LWR vessels

    NASA Astrophysics Data System (ADS)

    Rempe, J. L.; Knudson, D. L.

    2008-01-01

    Because of the impact that melt relocation and vessel failure has on subsequent progression and associated consequences of a light water reactor (LWR) accident, it is important to accurately predict the heatup and relocation of materials within the reactor vessel and heat transfer to and from the reactor vessel. Accurate predictions of such heat transfer phenomena require high temperature thermal properties. However, a review of vessel and structural steel material properties in severe accident analysis codes reveals that the required high temperature material properties are extrapolated with little, if any, data above 700 °C. To reduce uncertainties in predictions relying upon this extrapolated high temperature data, INL obtained data using laser-flash thermal diffusivity techniques for two metals used in LWR vessels: SA 533 Grade B, Class 1 (SA533B1) low alloy steel, which is used to fabricate most US LWR reactor vessels; and Type 304 Stainless Steel SS304, which is used in LWR vessel piping, penetration tubes, and internal structures. This paper summarizes the new data, compares it to existing data in the literature, and provides recommended correlations for thermal properties based on this data.

  16. Diagnostic tools for mixing models of stream water chemistry

    USGS Publications Warehouse

    Hooper, R.P.

    2003-01-01

    Mixing models provide a useful null hypothesis against which to evaluate processes controlling stream water chemical data. Because conservative mixing of end-members with constant concentration is a linear process, a number of simple mathematical and multivariate statistical methods can be applied to this problem. Although mixing models have been most typically used in the context of mixing soil and groundwater end-members, an extension of the mathematics of mixing models is presented that assesses the "fit" of a multivariate data set to a lower dimensional mixing subspace without the need for explicitly identified end-members. Diagnostic tools are developed to determine the approximate rank of the data set and to assess lack of fit of the data. This permits identification of processes that violate the assumptions of the mixing model and can suggest the dominant processes controlling stream water chemical variation. These same diagnostic tools can be used to assess the fit of the chemistry of one site into the mixing subspace of a different site, thereby permitting an assessment of the consistency of controlling end-members across sites. This technique is applied to a number of sites at the Panola Mountain Research Watershed located near Atlanta, Georgia.

  17. Water at surfaces with tunable surface chemistries and the chiral imprint of water around DNA

    NASA Astrophysics Data System (ADS)

    Petersen, Poul

    Aqueous interfaces are ubiquitous in atmospheric chemistry and biological systems but are notoriously hard to probe experimentally. Surface-specific vibrational spectroscopy offers an avenue to directly probe the vibrational modes of the water OH stretching band but this method is challenging to implement to buried surfaces. Here we present results from sum-frequency generation (SFG) spectroscopy probing the buried interface between a functionalized surface and aqueous solutions. Studying such buried surfaces offers the advantage of being able to systematically tune the surface chemistry using self-assembled monolayers, i.e. the hydrophobic and hydrophilic character, and examine the effect on the interfacial water. In addition to water at these controlled surfaces, we have initiated studying water at biological surfaces. This includes the solvation structure around DNA. X-ray experiments at cryogenic temperatures have found crystallographic water in the minor grove of DNA giving rise to the notion of a spine of hydration surrounding DNA. Such structured water should exhibit a chiral structure adapted from DNA. We investigate if such a chiral water structure exist around DNA at room temperature using chiral SFG. This work was supported by the National Science Foundation under a NSF CAREER Grant (CHE-1151079).

  18. Water chemistry controlled aggregation and photo-transformation of silver nanoparticles in environmental waters.

    PubMed

    Yin, Yongguang; Yang, Xiaoya; Zhou, Xiaoxia; Wang, Weidong; Yu, Sujuan; Liu, Jingfu; Jiang, Guibin

    2015-08-01

    The inevitable release of engineered silver nanoparticles (AgNPs) into aquatic environments has drawn great concerns about its environmental toxicity and safety. Although aggregation and transformation play crucial roles in the transport and toxicity of AgNPs, how the water chemistry of environmental waters influences the aggregation and transformation of engineered AgNPs is still not well understood. In this study, the aggregation of polyvinylpyrrolidone (PVP) coated AgNPs was investigated in eight typical environmental water samples (with different ionic strengths, hardness, and dissolved organic matter (DOM) concentrations) by using UV-visible spectroscopy and dynamic light scattering. Raman spectroscopy was applied to probe the interaction of DOM with the surface of AgNPs. Further, the photo-transformation and morphology changes of AgNPs in environmental waters were studied by UV-visible spectroscopy, inductively coupled plasma mass spectrometry, and transmission electron microscopy. The results suggested that both electrolytes (especially Ca(2+) and Mg(2+)) and DOM in the surface waters are key parameters for AgNP aggregation, and sunlight could accelerate the morphology change, aggregation, and further sedimentation of AgNPs. This water chemistry controlled aggregation and photo-transformation should have significant environmental impacts on the transport and toxicity of AgNPs in the aquatic environments. PMID:26257354

  19. Ground-water and water-chemistry data for the Willamette basin, Oregon

    USGS Publications Warehouse

    Orzol, Leonard L.; Wozniak, Karl C.; Meissner, Tiffany R.; Lee, Douglas B.

    2000-01-01

    This report presents ground-water data collected and compiled as part of a study of the ground-water resources of the Willamette River Basin, Oregon. The report includes tabulated information and a location map for 1,234 field-located water wells and 6 springs, hydrographs showing water-level fluctuations during various time periods for 265 of the wells, borehole geophysical data for 16 wells, and water-chemistry analyses from 125 wells and 6 springs. These data, as well as data for 4,752 additional fieldlocated wells and 1 spring, are included on a CD-ROM. In addition, the locations of the field-located wells and springs are provided in geographic information system formats on the CD-ROM.

  20. Deposition and Release of Microorganisms with Runoff Water Solution Chemistry

    NASA Astrophysics Data System (ADS)

    Bradford, S. A.

    2012-12-01

    Experiments were conducted to investigate the influence of solution chemistry on the transport, retention, and release of representative viral (coliphage phiX174) and bacterial (Escherichia coli D21g) indicator microorganisms in runoff water. Runoff experiments were conducted in a chamber (3 m long, 0.15 m wide, and 0.12 m high) packed with Tujunga sandy loam that was placed in a metal frame at a inclination of 7%. Microbial transport and retention studies were initiated by adding a step tracer pulse at a steady flow rate to the top side of the chamber and then monitoring the microbial concentrations in the runoff water outflow. Outflow concentrations of phiX174 and E. coli D21g were near input levels when deionized (DI) water was used at the background and eluting solutions. In contrast, significant amounts phiX174 and E. coli D21g retention occurred when the background and eluting solutions were 100 mM NaCl. Greater retention occurred for the smaller phiX174 likely because it had a higher diffusion coefficient and mainly irreversibly interacted with soil heterogeneities. Subsequent reduction in the solution ionic strength (IS) by flushing the chamber with DI water resulted in the release of a portion of the retained E. coli D21g, whereas much less phiX174 was released with a reduction in IS. Additional experiments were conducted by packing the top 1 cm of the chamber with soil spiked with E. coli D21g in 1 mM NaCl and then sequentially flushing the chamber with solutions that exhibited a step reduction in IS (100 mM, 50 mM, 25mM, and 1 mM NaCl). The amount of E. coli D21g recovered in the chamber effluent was inversely correlated with the solution IS. The optical density of the chamber effluent exhibited this same trend, indicating that other soil colloids (clays) were also strongly influenced by a reduction in solution IS. Consequently, the amount of E. coli D21g in the chamber effluent was strongly correlated with the optical density and electrical conductivity.

  1. The Effect of Water Chemistry on the Removal of Arsenic from Drinking Water During Iron Removal Treatment

    EPA Science Inventory

    This research investigates the effects of water chemistry, oxidant type and concentration on the removal of iron and arsenic from drinking water. The research will be conducted using one of the National Risk Management Research Laboratory’s Water Supply and Water Resources Divisi...

  2. Optimization of the water chemistry of the primary coolant at nuclear power plants with VVER

    SciTech Connect

    Barmin, L. F.; Kruglova, T. K.; Sinitsyn, V. P.

    2005-01-15

    Results of the use of automatic hydrogen-content meter for controlling the parameter of 'hydrogen' in the primary coolant circuit of the Kola nuclear power plant are presented. It is shown that the correlation between the 'hydrogen' parameter in the coolant and the 'hydrazine' parameter in the makeup water can be used for controlling the water chemistry of the primary coolant system, which should make it possible to optimize the water chemistry at different power levels.

  3. LWR fuel rod bundle behavior under severe fuel damage conditions

    SciTech Connect

    Kuczera, B. Hagen, S.; Hofmann, P.

    1988-01-01

    Light water reactor (LWR) safety research and development activities conducted at Kernforschungszentrum Karlsruhe have recently been reorganized with a concentrated mission under the LWR safety project group. The topics treated relate mainly to severe-accident analysis research and source term assessment as well as to source term mitigation measures. A major part of the investigations concerns the early phase of a severe core meltdown accident, specifically LWR rod assembly behavior under sever fuel damage (SFD) conditions. To determine the extent of fuel rod damage, including the relocation behavior of molten reaction products, damage propagation, time-dependent H{sub 2} generation from clad oxidation, and fragmentation of oxygen-embrittled materials during cooldown and quenching, extensive out-of-pile rod bundle experiments have been initiated in the new CORA test facility. The bundle parameters, such as rod dimensions, rod pitch, and grid spacer, can be adjusted to both pressurized water reactor (PWR) and boiling water reactor (BWR) conditions. Currently, the test program consists of 15 experiments in which the influence of Inconel grid spacer, (Ag,In,Cd)-absorber rods (PWR) and of B{sub 4}C control blades (BWR) on fuel damage initiation and damage propagation are being investigated for different boundary conditions. As of June 1988, four bundle tests had been successfully carried out for PWR accident conditions.

  4. Spent fuel dissolution rates as a function of burnup and water chemistry

    SciTech Connect

    Gray, W.J.

    1998-06-01

    To help provide a source term for performance-assessment calculations, dissolution studies on light-water-reactor (LWR) spent fuel have been conducted over the past few years at Pacific Northwest National Laboratory in support of the Yucca Mountain Site Characterization Project. This report describes that work for fiscal years 1996 through mid-1998 and includes summaries of some results from previous years for completeness. The following conclusions were based on the results of various flowthrough dissolution rate tests and on tests designed to measure the inventories of {sup 129}I located within the fuel/cladding gap region of different spent fuels: (1) Spent fuels with burnups in the range 30 to 50 MWd/kgM all dissolved at about the same rate over the conditions tested. To help determine whether the lack of burnup dependence extends to higher and lower values, tests are in progress or planned for spent fuels with burnups of 13 and {approximately} 65 MWd/kgM. (2) Oxidation of spent fuel up to the U{sub 4}O{sub 9+x} stage does not have a large effect on intrinsic dissolution rates. However, this degree of oxidation could increase the dissolution rates of relatively intact fuel by opening the grain boundaries, thereby increasing the effective surface area that is available for contact by water. From a disposal viewpoint, this is a potentially more important consideration than the effect on intrinsic rates. (3) The gap inventories of {sup 129}I were found to be smaller than the fission gas release (FGR) for the same fuel rod with the exception of the rod with the highest FGR. Several additional fuels would have to be tested to determine whether a generalized relationship exists between FGR and {sup 129}I gap inventory for US LWR fuels.

  5. Improving the safety of LWR power plants. Final report

    SciTech Connect

    Not Available

    1980-04-01

    This report documents the results of the Study to identify current, potential research issues and efforts for improving the safety of Light Water Reactor (LWR) power plants. This final report describes the work accomplished, the results obtained, the problem areas, and the recommended solutions. Specifically, for each of the issues identified in this report for improving the safety of LWR power plants, a description is provided in detail of the safety significance, the current status (including information sources, status of technical knowledge, problem solution and current activities), and the suggestions for further research and development. Further, the issues are ranked for action into high, medium, and low priority with respect to primarily (a) improved safety (e.g. potential reduction in public risk and occupational exposure), and secondly (b) reduction in safety-related costs (improving or maintaining level of safety with simpler systems or in a more cost-effective manner).

  6. FROZEN GROUND CONTROL ON SNOWMELT FLOWPATHS AND SURFACE WATER CHEMISTRY IN TWO ALPINE BASINS

    EPA Science Inventory

    This study will increase our understanding of how snowmelt flowpaths are influenced by frozen ground in mid-latitude alpine basins. It also will elucidate how these flowpaths dictate surface water chemistry in relation to snowmelt.

  7. Regional relationships between geomorphic/hydrologic parameters and surface water chemistry relative to acidic deposition

    SciTech Connect

    Rochelle, B.P.; Liff, C.I.; Campbell, W.G.; Cassell, D.L.; Church, M.R.

    1989-01-01

    The authors determined geomorphic and hydrologic parameters for 144 forested, lake watersheds in the Northeast (NE) of the United States based primarily on measurements from topographic maps. These parameters were used to test for relationships with selected surface water chemistry relevant to acidic deposition. Analyses were conducted on regional and subregional scales delineated based on soils, land use, physiography, total sulfur deposition and statistical clustering of selected geomorphic/hydrologic parameters. Significant relationships were found among the geomorphic/hydrologic parameters and the surface water chemistry for the NE. Elevation had the most significant relationship with surface water chemistry, particularly in the mountainous areas of the NE. Other factors occurring consistently as significant predictors of surface water chemistry were maximum relief, relief ratio, runoff, and estimates of basin elongation. Results suggest that elevational parameters might be surrogates for other watershed characteristics, such as soils or spatial deposition patterns.

  8. Analysis of valve failure data for LWR nuclear power plants

    SciTech Connect

    Schmidt, W. H.

    1980-01-01

    A computer analysis of the Nuclear Regulatory Commission (NRC) data file, compiled from Licensee Event Report (LER) data sheets, has been performed to characterize and highlight valve failures in light water reactor (LWR) nuclear power plants and provide guidance for valve improvement programs. The analysis is based on data from 1975 through 1978. Over this period, 889 valve citations were reported for pressurized water reactor (PWR) plants and 891 for boiling water reactor (BWR) plants. This report presents the pertinent LER data in a manner which indicates valve performance areas toward which improvement efforts may be directed.

  9. NATIONAL SURFACE WATER SURVEY: WESTERN LAKE SURVEY (PHASE 1 - SYNOPTIC CHEMISTRY) QUALITY ASSURANCE PLAN

    EPA Science Inventory

    The purpose of the National Surface Water Survey of the National Acid Precipitation Assessment Program is to evaluate the present water chemistry of lakes and streams, to determine the status of certain biotic resources, and to select regionally representative surface waters for ...

  10. Ground-water, surface-water, and water-chemistry data, Black Mesa area, northeastern Arizona, 1997

    USGS Publications Warehouse

    Littin, Gregory R.; Baum, Bradley M.; Truini, Margot

    1999-01-01

    The Black Mesa monitoring program is designed to document long-term effects of ground-water from the N aquifer by industrial and municipal users. The N aquifer is the major source of water in the 5,400-square-mile Black Mesa area, and the ground water occurs under confined and unconfined conditions. Monitoring activities include continuous and periodic measurements of (1) ground-water pumpage from the confined and unconfined parts of the aquifer, (2) ground-water levels in the confined and unconfined parts of the aquifer, (3) surface-water discharge, and (4) chemistry of the ground water and surface water. In 1997, ground-water withdrawals for industrial and municipal use totaled about 7,090 acre-feet, which is less than a 1-percent increase from 1996. Pumpage from the confined part of the aquifer increased by about 2 percent to 5,510 acre-feet, and pumpage from the unconfined part of the aquifer decreased by about 4 percent to 1,580 acre-feet. Water-level declines in the confined part during 1997 were recorded in 5 of 12 wells; however, the median change was a rise of about 0.2 foot as opposed to a decline of 2.8 feet for 1996. Water-level declines in the unconfined part were recorded in 7 of 15 wells, and the median change was 0.0 foot in 1997 as opposed to a decline of 0.5 foot in 1996. The low-flow discharge at the Moenkopi streamflow-gaging station ranged from 1.6 to 2.0 cubic feet per second in 1997. Streamflow-discharge measurements also were made at Laguna Creek, Dinnebito Wash, and Polacca Wash during 1997. The low-flow discharge ranged from 2.3 to 4.2 cubic feet per second at Laguna Creek, 0.44 to 0.48 cubic foot per second at Dinnebito Wash, and 0.15 to 0.26 cubic foot per second at Polacca Wash. Discharge was measured at three springs. Discharge from Moenkopi School Spring increased by about 3 gallons per minute from the measurement in 1996. Discharge from an unnamed spring near Dennehotso increased by 9.9 gallons per minute from the measurement made in

  11. DESTRUCTIVE EXAMINATION OF 3-CYCLE LWR (LIGHT WATER REACTOR) FUEL RODS FROM TURKEY POINT UNIT 3 FOR THE CLIMAX - SPENT FUEL TEST

    SciTech Connect

    ATKIN SD

    1981-06-01

    The destructive examination results of five light water reactor rods from the Turkey Point Unit 3 reactor are presented. The examinations included fission gas collection and analyses, burnup and hydrogen analyses, and a metallographic evaluation of the fuel, cladding, oxide, and hydrides. The rods exhibited a low fission gas release with all other results appearing representative for pressurized water reator fuel rods with similar burnups (28 GWd/MTU) and operating histories.

  12. Major ion chemistry of the Son River, India: Weathering processes, dissolved fluxes and water quality assessment

    NASA Astrophysics Data System (ADS)

    Maharana, Chinmaya; Gautam, Sandeep Kumar; Singh, Abhay Kumar; Tripathi, Jayant K.

    2015-08-01

    River Son, draining diverse lithologies in the subtropical climate of the peninsular sub-basin of the Ganga basin, is one of the major tributaries of the Ganga River. The chemistry of major ions in the surface water of the Son River was studied in detail to determine various source(s) and processes controlling its water chemistry, seasonal and spatial variations in water chemistry, dissolved fluxes and chemical denudation rate (CDR). The study shows that Ca2+, Mg2+ and HCO 3- are major ionic species in the river water. Most of the measured parameters exhibit a relatively lower concentration in the post-monsoon as compared to pre-monsoon season. The water chemistry highlights the influence of continental weathering aided by secondary contributions from ground water, saline/alkaline soils and anthropogenic activities in the catchment. Results also reflect the dominance of carbonate weathering over silicate weathering in controlling water composition. The Son River delivers about 4.2 million tons of dissolved loads annually to the Ganga River, which accounts for ˜6% of the total annual load carried by the Ganga River to the Bay of Bengal. The average CDR of the Son River is 59.5 tons km -2 yr -1, which is less than the reported 72 tons km -2 yr -1 of the Ganga River and higher than the global average of 36 tons km -2 yr -1. The water chemistry for the pre-monsoon and post-monsoon periods shows a strong seasonal control on solute flux and CDR values. The water chemistry indicates that the Son River water is good to excellent in quality for irrigation and also suitable for drinking purposes.

  13. Water chemistry of surface waters affected by the Fourmile Canyon wildfire, Colorado, 2010-2011

    USGS Publications Warehouse

    McCleskey, R. Blaine; Writer, Jeffrey H.; Murphy, Sheila F.

    2012-01-01

    In September 2010, the Fourmile Canyon fire burned about 23 percent of the Fourmile Creek watershed in Boulder County, Colo. Water-quality sampling of Fourmile Creek began within a month after the wildfire to assess its effects on surface-water chemistry. Water samples were collected from five sites along Fourmile Creek (above, within, and below the burned area) monthly during base flow, twice weekly during snowmelt runoff, and at higher frequencies during storm events. Stream discharge was also monitored. Water-quality samples were collected less frequently from an additional 6 sites on Fourmile Creek, from 11 tributaries or other inputs, and from 3 sites along Boulder Creek. The pH, electrical conductivity, temperature, specific ultraviolet absorbance, total suspended solids, and concentrations (dissolved and total) of major cations (calcium, magnesium, sodium, and potassium), anions (chloride, sulfate, alkalinity, fluoride, and bromide), nutrients (nitrate, ammonium, and phosphorus), trace metals (aluminum, arsenic, boron, barium, beryllium, cadmium, cobalt, chromium, copper, iron, mercury, lithium, manganese, molybdenum, nickel, lead, rubidium, antimony, selenium, strontium, vanadium, and zinc), and dissolved organic carbon are here reported for 436 samples collected during 2010 and 2011.

  14. Application of the organic on water reactions to prebiotic chemistry

    NASA Astrophysics Data System (ADS)

    Kolb, Vera M.

    2012-10-01

    The old view that prebiotic reactions in water are hampered by the low solubility of the organic compounds in water is now being revised due to the discoveries of the reactions "on water". These reactions occur in the heterogeneous system comprising of the organic compounds and water. Unexpectedly, such reactions are extremely efficient; they often give quantitative yields, and are accelerated in the presence of water as compared to the organic solvents. These "on water" reactions are not the same as the "in water" reactions, which occur in solution, and are thus homogenous. Examples of the "on water" reactions include Diels-Alder, Claisen, Passerini and Ugi reactions, among many others. Some of these reactions are multicomponent, but give a single product. We survey a selected number of the "on water" reactions, which have a potential prebiotic applications.

  15. Interstellar Ice Chemistry: From Water to Complex Organics

    NASA Astrophysics Data System (ADS)

    Oberg, Karin I.; Fayolle, E.; Linnartz, H.; van Dishoeck, E.; Fillion, J.; Bertin, M.

    2013-06-01

    Molecular cloud cores, protostellar envelopes and protoplanetary disk midplanes are all characterized by freeze-out of atoms and molecules (other than H and H2) onto interstellar dust grains. On the grain surface, atom addition reactions, especially hydrogenation, are efficient and H2O forms readily from O, CH3OH from CO etc. The result is an icy mantle typically dominated by H2O, but also rich in CO2, CO, NH3, CH3OH and CH4. These ices are further processed through interactions with radiation, electrons and energetic particles. Because of the efficiency of the freeze-out process, and the complex chemistry that succeeds it, these icy grain mantles constitute a major reservoir of volatiles during star formation and are also the source of much of the chemical evolution observed in star forming regions. Laboratory experiments allow us to explore how molecules and radicals desorb, dissociate, diffuse and react in ices when exposed to different sources of energy. Changes in ice composition and structure is constrained using infrared spectroscopy and mass spectrometry. By comparing ice desorption, segregation, and chemistry efficiencies under different experimental conditions, we can characterize the basic ice processes, e.g. diffusion of different species, that underpin the observable changes in ice composition and structure. This information can then be used to predict the interstellar ice chemical evolution. I will review some of the key laboratory discoveries on ice chemistry during the past few years and how they have been used to predict and interpret astronomical observations of ice bands and gas-phase molecules associated with ice evaporation. These include measurements of thermal diffusion in and evaporation from ice mixtures, non-thermal diffusion efficiencies (including the recent results on frequency resolved UV photodesorption), and the expected temperature dependencies of the complex ice chemistry regulated by radical formation and diffusion. Based on these

  16. Groundwater, surface-water, and water-chemistry data from C-aquifer monitoring program, northeastern Arizona, 2005-11

    USGS Publications Warehouse

    Brown, Christopher R.; Macy, Jamie P.

    2012-01-01

    Water-chemistry data for selected wells and baseflow investigations sites are presented. No well samples analyzed exceeded the U.S. Environmental Protection Agency Maximum Contaminant Level standards for drinking water, but several samples exceeded Secondary Maximum Contaminant Level standards for chloride, fluoride, sulfate, iron, and total dissolved solids.

  17. Applying the Philosophical Concept of Reduction to the Chemistry of Water: Implications for Chemical Education

    NASA Astrophysics Data System (ADS)

    Erduran, Sibel

    Even though philosophical themes in science education have been advocated for several decades, little attention has been paid to how these themes can be contextualized in the teaching of a particular domain of science. The purpose of this paper is to provide an example theoretical framework for applying a philosophical theme, reduction, in chemistry education. The inclusion of the concept reduction in chemistry education not only elaborates on this important philosophical thesis in the specific context of chemistry but also it might offer some insight into how students interest in philosophical aspects of chemistry might be stimulated. The consideration of concepts such as chemical composition, molecular structure and bonding in chemistry of water provides an example for the application of reduction in chemistry education. The water example also promotes the reflection on the microscopic, macroscopic and symbolic features of substances, themes which are repeatedly covered in secondary as well as tertiary chemical education. Some implications include the need for restructuring the curriculum in higher education to be more inclusive of the controversial nature of quantum mechanical applications in chemistry.

  18. The hydrochemistry of glacial Ebba River (Petunia Bay, Central Spitsbergen): Groundwater influence on surface water chemistry

    NASA Astrophysics Data System (ADS)

    Dragon, Krzysztof; Marciniak, Marek; Szpikowski, Józef; Szpikowska, Grażyna; Wawrzyniak, Tomasz

    2015-10-01

    The article presents the investigation of surface water chemistry changes of the glacial Ebba River (Central Spitsbergen) during three melting seasons of 2008, 2009 and 2010. The twice daily water chemistry analyses allow recognition of the surface water chemistry differentiation. The surface water chemistry changes are related to the river discharge and changes in the influence of different water balance components during each melting season. One of the most important process that influence river water component concentration increase is groundwater inflow from active layer occurring on the valley area. The significance of this process is the most important at the end of the melting season when temperatures below 0 °C occur on glaciers (resulting in a slowdown of melting of ice and snow and a smaller recharge of the river by the water from the glaciers) while the flow of groundwater is still active, causing a relatively higher contribution of groundwater to the total river discharge. The findings presented in this paper show that groundwater contribution to the total polar river water balance is more important than previously thought and its recognition allow a better understanding of the hydrological processes occurring in a polar environment.

  19. The influence of water chemistries on Flavobacterium columnare pathogenesis in channel catfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Columnaris disease can cause tremendous losses of freshwater fish. While it has been studied exhaustively, little is known about its affinity to specific water chemistries that affects attachment. Recent studies in our labs have illuminated this subject. In the first experiment, two waters were u...

  20. An Environmental Chemistry Experiment: The Determination of Radon Levels in Water.

    ERIC Educational Resources Information Center

    Welch, Lawrence E.; Mossman, Daniel M.

    1994-01-01

    Describes a radiation experiment developed to complement a new environmental chemistry laboratory curriculum. A scintillation counter is used to measure radon in water. The procedure relies on the fact that toluene will preferentially extract radon from water. Sample preparation is complete in less than 90 minutes. Because the level of…

  1. ADDRESSING EMERGING ISSUES IN WATER QUALITY THROUGH ENVIRONMENTAL CHEMISTRY

    EPA Science Inventory

    Public concern over cleanliness and safety of source and recreational waters has prompted researchers to look for indicators of water quality. Giving public water authorities multiple tools to measure and monitor levels of chemical contaminants, as well as chemical markers of c...

  2. Water and Life in the International Year of Chemistry

    ERIC Educational Resources Information Center

    Bernal, Pedro J.

    2011-01-01

    This commentary talks about the worldwide health impact of lack of access to potable water. Household water treatment and storage (HWTS) is described as one approach to improving potable water accessibility in which students and educators can make a contribution to alleviate the problem of lack of access. The author suggests that, as chemists,…

  3. Ground-water, surface-water, and water-chemistry data, Black Mesa area, northeastern Arizona, 1996

    USGS Publications Warehouse

    Littin, Gregory R.; Monroe, Stephen A.

    1997-01-01

    The Black Mesa monitoring program is designed to document long-term effects of ground-water pumping from the N aquifer by industrial and municipal users. The N aquifer is the major source of water in the 5,400-square-mile Black Mesa area, and the ground water occurs under confined and unconfined conditions. Monitoring activities include continuous and periodic measurements of (1) ground-water pumpage from the confined and unconfined parts of the aquifer, (2) ground-water levels in the confined and unconfined areas of the aquifer, (3) surface-water discharge, and (4) chemistry of the ground water and surface water. In 1996, ground-water withdrawals for industrial and municipal use totaled about 7,040 acre-feet, which is less than a 1-percent decrease from 1995. Pumpage from the confined part of the aquifer decreased by about 3 percent to 5,390 acre-feet, and pumpage from the unconfined part of the aquifer increased by about 9 percent to 1,650 acre-feet. Water-level declines in the confined area during 1996 were recorded in 11 of 13 wells, and the median change was a decline of about 2.7 feet as opposed to a decline of 1.8 feet for 1995. Water-level declines in the unconfined area were recorded in 11 of 18 wells, and the median change was a decline of 0.5 foot in 1996 as opposed to a decline of 0.1 foot in 1995. The average low-flow discharge at the Moenkopi streamflow-gaging station was 2.3 cubic feet per second in 1996. Streamflow-discharge measurements also were made at Laguna Creek, Dinnebito Wash, and Polacca Wash during 1996. Average low-flow discharge was 2.3 cubic feet per second at Laguna Creek, 0.4 cubic foot per second at Dinnebito Wash, and 0.2 cubic foot per second at Polacca Wash. Discharge was measured at three springs. Discharge from Moenkopi School Spring decreased by about 2 gallons per minute from the measurement in 1995. Discharge from an unnamed spring near Dennehotso decreased by 1.3 gallons per minute from the measurement made in 1995; however

  4. Spatial organization of stream water discharge and chemistry in forested headwaters

    NASA Astrophysics Data System (ADS)

    Egusa, T.; Ohte, N.; Oda, T.; Suzuki, M.

    2013-12-01

    It has long been known that, in small catchments, stream water discharge and chemistry are highly variable but the variability decreases gradually with an increase in the catchment area. Wood et al. (1988) showed that model calculations of infiltration and the runoff rate became constant above a certain threshold area. They defined the threshold area as the representative elementary area (REA) and stated that above the REA only minimum knowledge of the underlying parameters is needed to explain the stream water discharge and chemistry. Subsequently, empirical studies were conducted in several catchments. These studies all verified the existence of an REA in real catchments and indicated that the REA values differed among catchments. The results also suggested that the confluence processes of stream water discharge and chemistry differed among catchments. However, it has not been clarified how the confluence processes behave and why processes differ among catchments. One of the unclear things to resolve is whether the variability of discharge and chemistry among small catchments can be regarded as randomness or if it is organized. Two previous studies examined it and reported the opposite results. Woods et al. (1995) reported that organization was apparent from their observations of specific discharge. However, Asano and Uchida (2010) stated that their results for SiO2 could be regarded as randomness. These studies targeted different observed items and different catchments. Therefore, general knowledge about organization of stream water discharge and chemistry has not been obtained. We observed spatial variability of stream water discharge and chemistry and examined the existence of spatial organization by using the statistical method. Our objective was to elucidate whether the spatial organization exists about stream water discharge and chemistry. Observations were conducted in three forested catchments in Japan. Snapshot samplings of stream water discharge and

  5. Chemistry and movement of ground water, Nevada Test Site

    USGS Publications Warehouse

    Schoff, S.L.; Moore, J.E.

    1964-01-01

    Three chemical types of ground water are distinguished at the Nevada Test Site and vicinity. A sodium-potassium water is related to tuff (in part zeolitized) and to alluvium containing detrital tuff. A calcium-magnesium water is related to limestone and dolomite, or to alluvium containing detritus of these rock types. A mixed chemical type, containing about as much sodium and potassium as calcium and magnesium, may result from the addition of one of the first two types of water to the other; to passage of water first through tuff and then through carbonate rock, or vice versa; and to ion-exchange during water travel. Consideration of the distribution of these water types, together with the distribution of sodium in the water and progressive changes in the dissolved solids, suggests that the ground water in the Nevada Test Site probably moves toward the Amargosa Desert, not into Indian Spring Valley and thence southeastward toward Las Vegas. The low dissolved solids content of ground-water reservoirs in alluvium and tuff of the enclosed basins indicates that recharge is local in origin.

  6. Ground-water, surface-water, and water-chemistry data, Black Mesa area, northeastern Arizona--2004-05

    USGS Publications Warehouse

    Truini, Margot; Macy, J.P.

    2006-01-01

    The N aquifer is the major source of water in the 5,400-square-mile area of Black Mesa in northeastern Arizona. Availability of water is an important issue in this area because of continued industrial and municipal use, a growing population, and precipitation of about 6 to 14 inches per year. The monitoring program in the Black Mesa area has been operating since 1971 and is designed to determine the long-term effects of ground-water withdrawals from the N aquifer for industrial and municipal uses. The monitoring program includes measurements of (1) ground-water pumping, (2) ground-water levels, (3) spring discharge, (4) surface-water discharge, (5) ground-water chemistry, and (6) periodic testing of ground-water withdrawal meters. In 2004, total ground-water withdrawals were 7,210 acre-feet, industrial withdrawals were 4,370 acre-feet, and municipal withdrawals were 2,840 acre-feet. From 2003 to 2004, total withdrawals decreased by less than 1 percent, industrial withdrawals decreased by 2 percent, and municipal withdrawals increased by 2 percent. From 2004 to 2005, annually measured water levels declined in 6 of 13 wells in the unconfined areas of the aquifer, and the median change was -0.1 foot. Water levels declined in 8 of 12 wells in the confined area of the aquifer, and the median change was -1.2 feet. From the prestress period (prior to 1965) to 2005, the median water-level change for 33 wells was -9.0 feet. Median water-level changes were -0.6 foot for 16 wells in the unconfined areas and -32.0 feet for 17 wells in the confined area. Discharges were measured once in 2004 and once in 2005 at four springs. Discharge increased by 8 percent at Pasture Canyon Spring, decreased by 5 percent at Moenkopi School Spring, increased by 71 percent at an unnamed spring near Dennehotso, and stayed the same at Burro Spring. For the period of record at each spring, discharges from the four springs have fluctuated; however, an increasing or decreasing trend is not apparent

  7. Ground-water, surface-water, and water-chemistry data, Black Mesa area, northeastern Arizona, 2002-03

    USGS Publications Warehouse

    Truini, Margot; Thomas, Blakemore E.

    2004-01-01

    The N aquifer is the major source of water in the 5,400-square-mile area of Black Mesa in northeastern Arizona. Availability of water is an important issue in this area because of continued industrial and municipal use, a growing population, and precipitation of about 6 to 14 inches per year. The monitoring program in the Black Mesa area has been operating since 1971 and is designed to determine the long-term effects of ground-water withdrawals from the N aquifer for industrial and municipal uses. The monitoring program includes measurements of (1) ground-water pumping, (2) ground-water levels, (3) spring discharge, (4) surface-water discharge, (5) ground-water chemistry, and (6) periodic testing of ground-water withdrawal meters. In 2002, total ground-water withdrawals were 8,000 acre-feet, industrial use was 4,640 acre-feet, and municipal use was 3,360 acre-feet. From 2001 to 2002, total withdrawals increased by 4 percent, industrial use increased by 2 percent, and municipal use increased by 7 percent. Flowmeter testing was completed for 32 municipal wells in 2003. The median difference between pumping rates for the permanent meter and a test meter for all the sites tested was -2.0 percent. Values ranged from -13.7 percent at Hopi High School no. 2 to +12.9 percent at Shonto PM3. From 2002 to 2003, water levels declined in 5 of 13 wells in the unconfined part of the aquifer, and the median change was 0.0 foot. Water levels declined in 8 of 13 wells in the confined part of the aquifer, and the median change was -1.1 feet. From the prestress period (prior to 1965) to 2003, the median water-level change for 26 wells was -8.3 feet. Median water-level changes were -0.4 foot for 13 wells in the unconfirned part of the aquifer and -60.3 feet for 13 wells in the confined part. Discharges were measured once in 2002 and once in 2003 at four springs. Discharge decreased by 16 percent at Pasture Canyon Spring, increased 10 percent at Moenkopi Spring and 90 percent at an

  8. Ground-water, surface-water, and water-chemistry data, Black Mesa area, northeastern Arizona--2003-04

    USGS Publications Warehouse

    Truini, Margot; Macy, Jamie P.; Porter, Thomas J.

    2005-01-01

    The N aquifer is the major source of water in the 5,400-square-mile area of Black Mesa in northeastern Arizona. Availability of water is an important issue in this area because of continued industrial and municipal use, a growing population, and precipitation of about 6 to 14 inches per year. The monitoring program in the Black Mesa area has been operating since 1971 and is designed to determine the long-term effects of ground-water withdrawals from the N aquifer for industrial and municipal uses. The monitoring program includes measurements of (1) ground-water pumping, (2) ground-water levels, (3) spring discharge, (4) surface-water discharge, (5) ground-water chemistry, and (6) periodic testing of ground-water withdrawal meters. In 2003, total ground-water withdrawals were 7,240 acre-feet, industrial withdrawals were 4,450 acre-feet, and municipal withdrawals were 2,790 acre-feet. From 2002 to 2003, total withdrawals decreased by 10 percent, industrial withdrawals decreased by 4 percent, and municipal withdrawals decreased by 20 percent. Flowmeter testing was completed for 24 municipal wells in 2004. The median difference between pumping rates for the permanent meter and a test meter for all the sites tested was -2.9 percent. Values ranged from -10.9 percent at Forest Lake NTUA 1 to +7.8 percent at Rough Rock NTUA 2. From 2003 to 2004, water levels declined in 6 of 12 wells in the unconfined part of the aquifer, and the median change was -0.1 foot. Water levels declined in 7 of 11 wells in the confined part of the aquifer, and the median change was -2.7 feet. From the prestress period (prior to 1965) to 2003, the median water-level change for 26 wells was -23.2 feet. Median water-level change were -6.1 feet for 14 wells in the unconfined parts of the aquifer and and -72.1 feet for 12 wells in the confined part. Discharges were measured once in 2003 and once in 2004 at four springs. Discharge stayed the same at Pasture Canyon Spring, increased 9 percent at

  9. Chemistry of spring and well waters on Kilauea Volcano, Hawaii, and vicinity

    SciTech Connect

    Janik, C.J.; Nathenson, M.; Scholl, M.A.

    1994-12-31

    Published and new data for chemical and isotopic samples from wells and springs on Kilauea Volcano and vicinity are presented. These data are used to understand processes that determine the chemistry of dilute meteoric water, mixtures with sea water, and thermal water. Data for well and spring samples of non-thermal water indicate that mixing with sea water and dissolution of rock from weathering are the major processes that determine the composition of dissolved constituents in water. Data from coastal springs demonstrate that there is a large thermal system south of the lower east rift of Kilauea. Samples of thermal water from shallow wells in the lower east rift and vicinity have rather variable chemistry indicating that a number of processes operate in the near surface. Water sampled from the available deep wells is different in composition from the shallow thermal water, indicating that generally there is not a significant component of deep water in the shallow wells. Data for samples from available deep wells show significant gradients in chemistry and steam content of the reservoir fluid. These gradients are interpreted to indicate that the reservoir tapped by the existing wells is an evolving vapor-dominated system.

  10. Chemistry of water collected from an unventilated drift, Yucca Mountain, Nevada

    USGS Publications Warehouse

    Marshall, B.D.; Oliver, T.A.; Peterman, Z.E.

    2007-01-01

    Water samples (referred to as puddle water samples) were collected from the surfaces of a conveyor belt and plastic sheeting in the unventilated portion of the Enhanced Characterization of the Repository Block (ECRB) Cross Drift in 2003 and 2005 at Yucca Mountain, Nevada. The chemistry of these puddle water samples is very different than that of pore water samples from borehole cores in the same region of the Cross Drift or than seepage water samples collected from the Exploratory Studies Facility tunnel in 2005. The origin of the puddle water is condensation on surfaces of introduced materials and its chemistry is dominated by components of the introduced materials. Large CO2 concentrations may be indicative of localized chemical conditions induced by biologic activity. ?? 2007 Materials Research Society.

  11. Chemistry of Water Collected From an Unventilated Drift, Yucca Mountain, Nevada

    SciTech Connect

    Marshall, Brian D.; Peterman, Zell E.

    2007-07-01

    Water samples (referred to as puddle water samples) were collected from the surfaces of a conveyor belt and plastic sheeting in the unventilated portion of the Enhanced Characterization of the Repository Block (ECRB) Cross Drift in 2003 and 2005 at Yucca Mountain, Nevada. The chemistry of these puddle water samples is very different than that of pore water samples from borehole cores in the same region of the Cross Drift or than seepage water samples collected from the Exploratory Studies Facility tunnel in 2005. The origin of the puddle water is condensation on surfaces of introduced materials and its chemistry is dominated by components of the introduced materials. Large CO{sub 2} concentrations may be indicative of localized chemical conditions induced by biologic activity. (authors)

  12. Variance in water chemistry parameters in isolated wetlands of Florida, USA, and relationships with macroinvertebrate and diatom community structure

    EPA Science Inventory

    Eighty small isolated wetlands throughout Florida were sampled in 2005 to explore within-site variability of water chemistry parameters and relate water chemistry to macroinvertebrate and diatom community structure. Three samples or measures of water were collected within each si...

  13. Water chemistry influences the toxicity of silver to the green-lipped mussel Perna viridis.

    PubMed

    Vijayavel, Kannappan

    2010-08-01

    The study determined the influence and relative importance of water chemistry parameters (pH, alkalinity, hardness) on the acute toxicity of silver to the green mussel Perna viridis. A preliminary bioassay revealed that 4 mg L(-1) of silver caused 50% mortality (LC50) in 96 h for mussels placed in seawater with pH 8.5, hardness 1,872 mg L(-1), and alkalinity 172 mg L(-1). Mortality of mussels increased with decreasing pH and increasing hardness and alkalinity variables. In contrast the mortality decreased with increasing pH and decreasing hardness and alkalinity values. The water chemistry also affected the concentration of silver in experimental seawater and bioaccumulation of silver in mussels. The results revealed that the chemical properties of seawater must be considered while conducting toxicity tests with metals like silver. The possible explanations for the influence of water chemistry on silver toxicity to P. viridis are discussed. PMID:19565346

  14. Spatial and temporal patterns in water chemistry of two high elevation lakes in southeast Wyoming

    SciTech Connect

    Musselman, R.C.

    1995-12-31

    The Glacier Lakes Ecosystem Experiments Site (GLEES) was established to examine the effects of atmospheric deposition and climate change on alpine and subalpine ecosystems. This report documents temporal and spatial trends during 1993 in water chemistry in East and West Glacier Lakes. Data are presented on seasonal and lake depth changes in water chemistry of the two lakes. The application of the results to appropriate sampling protocols for two alpine lakes is discussed. Both lakes were sampled during the same day, at midday. Samples were kept cool, returned to the lab the same day, and filtered for analysis. Samples were analyzed for cations and anions, pH, and conductivity at the Rocky Mountain Station Water Chemistry laboratory. Silica and aluminum were also measured for some sample dates.

  15. Tools for placing the radiological health hazard in perspective following a severe emergency at a light water reactor (LWR) or its spent fuel pool.

    PubMed

    McKenna, Thomas; Welter, Phillip Vilar; Callen, Jessica; Martincic, Rafael; Dodd, Brian; Kutkov, Vladimir

    2015-01-01

    Experience from past nuclear and radiological emergencies shows that placing the radiological health hazard in perspective and having a definition of "safe" are required in order to prevent members of the public, those responsible for protecting the public (i.e., decision makers), and others from taking inappropriate and damaging actions that are not justified based on the radiological health hazard. The principle concerns of the public during a severe nuclear power plant or spent fuel pool emergency are "Am I safe?" and "What should I do to be safe?" However, these questions have not been answered to the satisfaction of the public, despite various protective actions being implemented to ensure their safety. Instead, calculated doses or various measured quantities (e.g., ambient dose rate or radionuclide concentrations) are used to describe the situation to the public without placing them into perspective in terms of the possible radiological health hazard, or if they have, it has been done incorrectly. This has contributed to members of the public taking actions that do more harm than good in the belief that they are protecting themselves. Based on established international guidance, this paper provides a definition of "safe" for the radiological health hazard for use in nuclear or radiological emergencies and a system for putting the radiological health hazard in perspective for quantities most commonly measured after a release resulting from a severe emergency at a light water reactor or its spent fuel pool. PMID:25437516

  16. Water chemistry and antimicrobial treatment in poultry processing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study examined the influence of calcium and magnesium ions in process water on the solubility of trisodium phosphate. Water used in poultry processing operations may be treated with sanitizers such as trisodium phosphate to reduce microbial activity and the risk of contamination. This occurs wh...

  17. CLOUD WATER CHEMISTRY AND THE PRODUCTION OF SULFATES IN CLOUDS

    EPA Science Inventory

    Measurements are presented of the pH and ionic content of water collected in clouds over Western Washington and the Los Angeles Basin. Evidence for sulfate production in some of the clouds is presented. Not all of the sulfur in the cloud water was in the form of sulfate. However,...

  18. Fast-Geomimicking using Chemistry in Supercritical Water.

    PubMed

    Dumas, Angela; Claverie, Marie; Slostowski, Cédric; Aubert, Guillaume; Careme, Cristel; Le Roux, Christophe; Micoud, Pierre; Martin, François; Aymonier, Cyril

    2016-08-16

    Herein we introduce a powerful and fast method to produce nanominerals using a bottom up approach. The supercritical hydrothermal flow synthesis is exploited to produce model nanominerals by mimicking natural environments at high temperatures under pressure. This innovative concept is demonstrated with the talc synthesis; this represents a major technical breakthrough since it allows decreasing the mineral-synthesis time from tens of hours to tens of seconds. Through this example, we show these nanominerals exhibit new crystal-chemistry signals and new properties. This approach provides a means to reproduce the early stages of formation of minerals in different natural environments from sedimentary environments (low temperature and pressure) to hydrothermal/metamorphic environments (high temperature and high pressure). PMID:27321954

  19. Impacts of Lithological and Anthropogenic Factors Affecting Water Chemistry in the Upper Paraguay River Basin.

    PubMed

    Rezende-Filho, Ary T; Valles, Vincent; Furian, Sônia; Oliveira, Célia M S C; Ouardi, Jamila; Barbiero, Laurent

    2015-11-01

    Located in the Upper Paraguay River Basin (UPRB), the Pantanal is considered the world's largest wetland, being rather pristine although increasingly threatened by development programs. The main objective of this paper is to provide a baseline of water chemistry for this region, which is largely unknown as a result of poor accessibility. We used two datasets (70 and 122 water samples) collected in the Pantanal floodplain and surrounding uplands during the wet season occurring from November to March. From the major-ion mineral chemistry, dissolved silica, pH, electrical conductivity (EC), and the ionic forms of N, principal components analysis (PCA) treatments were used to identify and rank the main factors of variability and decipher the associated processes affecting the water chemistry. The results revealed that the water mineral concentration was a major factor of variability and it must be attributed first to lithology and second to agricultural inputs from extensive crop cultivation areas that mainly affects sulfate (SO) concentration on the eastern edge of the Pantanal. These processes influence the floodplain, where (i) the mixing of waters remains the main process, (ii) the weight of the biological and redox processes increased, and (iii) the chemical signature of the extensive cropping is transferred along the São Lourenço Basin down to its confluence with the Cuiaba River. Optimized parameters based on projections in the main factorial score plots were used for the mapping of lithological and agricultural impacts on water chemistry. PMID:26641335

  20. Ground-water, surface-water and water-chemistry data, Black Mesa area, northeastern Arizona: 2001-02

    USGS Publications Warehouse

    Thomas, Blakemore E.

    2002-01-01

    The N aquifer is the major source of water in the 5,400-square-mile area of Black Mesa in northeastern Arizona. Availability of water is an important issue in this area because of continued industrial and municipal use, a growing population, and precipitation of about 6 to 14 inches per year. The monitoring program in the Black Mesa area has been operating since 1971 and is designed to determine the long-term effects of ground-water withdrawals from the N aquifer for industrial and municipal uses. The monitoring program includes measurements of (1) ground-water pumping, (2) ground-water levels, (3) spring discharge, (4) surface-water discharge, and (5) ground-water chemistry. In 2001, total ground-water withdrawals were 7,680 acre-feet, industrial use was 4,530 acre-feet, and municipal use was 3,150 acre-feet. From 2000 to 2001, total withdrawals decreased by 1 percent, industrial use increased by 1 percent, and municipal use decreased by 3 percent. From 2001 to 2002, water levels declined in 5 of 14 wells in the unconfined part of the aquifer, and the median change was +0.2 foot. Water levels declined in 12 of 17 wells in the confined part of the aquifer, and the median change was -1.4 feet. From the prestress period (prior to 1965) to 2002, the median water-level change for 32 wells was -15.8 feet. Median water-level changes were -1.3 feet for 15 wells in the unconfined part of the aquifer and -31.7 feet for 17 wells in the confined part. Discharges were measured once in 2001 and once in 2002 at four springs. Discharges decreased by 26 percent and 66 percent at two springs, increased by 100 percent at one spring, and did not change at one spring. For the past 10 years, discharges from the four springs have fluctuated; however, an increasing or decreasing trend is not apparent. Continuous records of surface-water discharge have been collected from 1976 to 2001 at Moenkopi Wash, 1996 to 2001 at Laguna Creek, 1993 to 2001 at Dinnebito Wash, and 1994 to 2001 at

  1. Ground-water, surface-water, and water-chemistry data, Black Mesa area, Northeastern Arizona: 1999

    USGS Publications Warehouse

    Thomas, Blakemore E.; Truini, Margot

    2000-01-01

    The N aquifer is the major source of water in the 5,400-square-mile area of Black Mesa in northeastern Arizona. Availability of water is an important issue in this area because of continued industrial and municipal use, a growing population, and a precipitation of only about 6 to 12 inches per year. The monitoring program in Black Mesa has been operating since 1971 and is designed to determine the long-term effects of ground-water withdrawals from the N aquifer for industrial and municipal uses. The monitoring program includes measurements of (1) ground-water pumping, (2) ground-water levels, (3) spring discharge, (4) surface-water discharge, and (5) ground-water chemistry. In 1999, total ground-water withdrawals were 7,110 acre-feet, industrial use was 4,210 acre-feet, and municipal use was 2,900 acre-feet. From 1998 to 1999, total withdrawals increased by 0.7 percent, industrial use increased by 4 percent, and municipal use decreased by 4 percent. From 1998 to 1999, water levels declined in 11 of 15 wells in the unconfined part of the aquifer, and the median decline was 0.7 foot. Water levels declined in 14 of 16 wells in the confined part of the aquifer, and the median decline was 1.2 feet. From the prestress period (prior to 1965) to 1999, the median water-level decline in 31 wells was 10.6 feet. Median water-level changes were 0.0 foot for 15 wells in the unconfined part of the aquifer and a decline of 45.5 feet in 16 wells in the confined part. From 1998 to 1999, discharges were measured annually at four springs. Discharges declined 30 percent and 3 percent at 2 springs, did not change at 1 spring, and increased by 11 percent at 1 spring. For the past 10 years, discharges from the four springs have fluctuated; however, an increasing or decreasing trend was not observed. Continuous records of surface-water discharge have been collected from July 1976 to 1999 at Moenkopi Wash, July 1996 to 1999 at Laguna Creek, June 1993 to 1999 at Dinnebito Wash, and April

  2. Analytical chemistry in water quality monitoring during manned space missions

    NASA Astrophysics Data System (ADS)

    Artemyeva, Anastasia A.

    2016-09-01

    Water quality monitoring during human spaceflights is essential. However, most of the traditional methods require sample collection with a subsequent ground analysis because of the limitations in volume, power, safety and gravity. The space missions are becoming longer-lasting; hence methods suitable for in-flight monitoring are demanded. Since 2009, water quality has been monitored in-flight with colorimetric methods allowing for detection of iodine and ionic silver. Organic compounds in water have been monitored with a second generation total organic carbon analyzer, which provides information on the amount of carbon in water at both the U.S. and Russian segments of the International Space Station since 2008. The disadvantage of this approach is the lack of compound-specific information. The recently developed methods and tools may potentially allow one to obtain in-flight a more detailed information on water quality. Namely, the microanalyzers based on potentiometric measurements were designed for online detection of chloride, potassium, nitrate ions and ammonia. The recent application of the current highly developed air quality monitoring system for water analysis was a logical step because most of the target analytes are the same in air and water. An electro-thermal vaporizer was designed, manufactured and coupled with the air quality control system. This development allowed for liberating the analytes from the aqueous matrix and further compound-specific analysis in the gas phase.

  3. Sterilization Resistance of Bacterial Spores Explained with Water Chemistry.

    PubMed

    Friedline, Anthony W; Zachariah, Malcolm M; Middaugh, Amy N; Garimella, Ravindranath; Vaishampayan, Parag A; Rice, Charles V

    2015-11-01

    Bacterial spores can survive for long periods without nutrients and in harsh environmental conditions. This survival is influenced by the structure of the spore, the presence of protective compounds, and water retention. These compounds, and the physical state of water in particular, allow some species of bacterial spores to survive sterilization schemes with hydrogen peroxide and UV light. The chemical nature of the spore core and its water has been a subject of some contention and the chemical environment of the water impacts resistance paradigms. Either the spore has a glassy core, where water is immobilized along with other core components, or the core is gel-like with mobile water diffusion. These properties affect the movement of peroxide and radical species, and hence resistance. Deuterium solid-state NMR experiments are useful for examining the nature of the water inside the spore. Previous work in our lab with spores of Bacillus subtilis indicate that, for spores, the core water is in a more immobilized state than expected for the gel-like core theory, suggesting a glassy core environment. Here, we report deuterium solid-state NMR observations of the water within UV- and peroxide-resistant spores from Bacillus pumilus SAFR-032. Variable-temperature NMR experiments indicate no change in the line shape after heating to 50 °C, but an overall decrease in signal after heating to 100 °C. These results show glass-like core dynamics within B. pumilus SAFR-032 that may be the potential source of its known UV-resistance properties. The observed NMR traits can be attributed to the presence of an exosporium containing additional labile deuterons that can aid in the deactivation of sterilizing agents. PMID:26435315

  4. Investigation of valve failure problems in LWR power plants

    SciTech Connect

    1980-04-01

    An analysis of component failures from information in the computerized Nuclear Safety Information Center (NSIC) data bank shows that for both PWR and BWR plants the component category most responsible for approximately 19.3% of light water reactor (LWR) power plant shutdowns. This investigation by Burns and Roe, Inc. shows that the greatest cause of shutdowns in LWRs due to valve failures is leakage from valve stem packing. Both BWR plants and PWR plants have stem leakage problems (BWRs, 21% and PWRs, 34%).

  5. Cloud water chemistry and the production of sulfates in clouds

    NASA Technical Reports Server (NTRS)

    Hegg, D. A.; Hobbs, P. V.

    1981-01-01

    Measurements are presented of the pH and ionic content of water collected in clouds over western Washington and the Los Angeles Basin. Evidence for sulfate production in some of the clouds is presented. Not all of the sulfur in the cloud water was in the form of sulfate. However, the measurements indicate that the production of sulfate in clouds is of considerable significance in the atmosphere. Comparison of field measurements with model results show reasonable agreement and suggest that the production of sulfate in cloud water is a consequence of more than one conversion mechanism.

  6. Water oxidation in photosystem II: From radical chemistry to multielectron chemistry

    SciTech Connect

    Babcock, G.T.; Barry, B.A.; Debus, R.J.; Hoganson, C.W.; Atamian, M.; McIntosh, L.; Sithole, I. ); Yocum, C.F. )

    1989-12-12

    This review article describes the progress that has been made in understanding the photosystem II/oxygen-evolving complex (PSII/OEC). Photosystem II forms the photochemical core of the system: upon light absorption PSII generates oxidizing equivalents or holes at sufficiently high potential to oxidize water. The OEC can exist in five redox states depending on the number of stored oxidizing equivalents. These redox states are designated S{sub 0}-S{sub 4}, with S{sub 4} being the most oxidizing and capable of oxidizing water. The rapid progress in researching this important membrane protein has been due to several factors. First, oxygen evolution has proven to be quite stable to biochemical manipulation. Second, the crystallization of the bacterial reaction center, the realization of the analogies between it and PSII, and the demonstration of the relevance of constructing experiments on the basis of the analogy have provided a shortcut to dissecting the oxygen-evolving system. Finally, because the water-splitting process, like all photosynthetic reactions, can be initiated by light, kinetic studies over the picosecond to second time regime have become possible. The majority of the current work is aimed at determining the structure of the complex.

  7. Effect of Surface Chemistry on Water Interaction with Cu(111).

    PubMed

    Antony, Andrew C; Liang, Tao; Akhade, Sneha A; Janik, Michael J; Phillpot, Simon R; Sinnott, Susan B

    2016-08-16

    The interfacial dynamics of water in contact with bare, oxidized, and hydroxylated copper surfaces are examined using classical molecular dynamics (MD) simulations. A third-generation charge-optimized many-body (COMB3) potential is used in the MD simulations to investigate the adsorption of water molecules on Cu(111), and the results are compared to the findings of density functional theory (DFT) calculations. The adsorption energies and structures predicted by COMB3 are generally consistent with those determined with DFT. The COMB3 potential is then used to investigate the wetting behavior of water nanodroplets on Cu(111) at 20, 130, and 300 K. At room temperature, the simulations predict that the spreading rate of the base radius, R0, of a water droplet with a diameter of about 1.5 nm exhibits a spreading rate of R0 ≈ t(0.16) and a final base radius of 3.5 nm. At 20 and 130 K, water droplets are predicted to retain their structure after adsorption on Cu(111) and to undergo minimal spreading in agreement with scanning tunneling microscopy data. When the same water droplet encounters a reconstructed, oxidized Cu(111) surface, the classical MD simulations predict wetting with a spreading rate of R ≈ t(0.14) and a final base radius of 3.0 nm. Similarly, our MD simulations predict a spreading rate of R ≈ t(0.14) and a final base radius of 2.5 nm when water encounters OH-covered Cu(111). These results indicate that oxidation and hydroxylation cause a reduction in the degree of spreading and final base radius that is directly associated with a decreased spreading rate for water nanodroplets on copper. PMID:27442055

  8. Methods for incorporating effects of LWR coolant environment into ASME code fatigue evaluations.

    SciTech Connect

    Chopra, O. K.

    1999-04-15

    The ASME Boiler and Pressure Vessel Code provides rules for the construction of nuclear power plant components. Appendix I to Section HI of the Code specifies design fatigue curves for structural materials. However, the effects of light water reactor (LWR) coolant environments are not explicitly addressed by the Code design curves. Recent test data illustrate potentially significant effects of LWR environments on the fatigue resistance of carbon and low-alloy steels and austenitic stainless steels (SSs). Under certain loading and environmental conditions, fatigue lives of carbon and low-alloy steels can be a factor of {approx}70 lower in an LWR environment than in air. These results raise the issue of whether the design fatigue curves in Section III are appropriate for the intended purpose. This paper presents the two methods that have been proposed for incorporating the effects of LWR coolant environments into the ASME Code fatigue evaluations. The mechanisms of fatigue crack initiation in carbon and low-alloy steels and austenitic SSs in LWR environments are discussed.

  9. Water chemistry of the Zhujiang (Pearl River): Natural processes and anthropogenic influences

    NASA Astrophysics Data System (ADS)

    Zhang, Shu-Rong; Lu, Xi Xi; Higgitt, David Laurence; Chen, Chen-Tung Arthur; Sun, Hui-Guo; Han, Jing-Tai

    2007-03-01

    The temporal and spatial variations of major ions in the Zhujiang (Pearl River) were analyzed using long-term water chemistry data of major dissolved ions (Ca2+, Mg2+, the sum of Na+ and K+, HCO3-, SO42-, Cl-) and dissolved silica (SiO2) from 75 hydrological stations (1958-2002). The total dissolved solids (TDS) within the Zhujiang basin varies from 34.0 mg/l to 416.1 mg/l generally decreasing from upstream to downstream along the main stem of the Zhujiang. Rock weathering is the dominant controlling factor for the water chemistry of the Zhujiang, and more specifically, on average, 68% (22-92%) of total dissolved load comes from carbonate weathering, 22% (2-68%) from silicate weathering, and 10% (3-24%) from evaporite weathering, respectively. The flux calculations indicate that in total about 41.8 × 106 tonnes/year of TDS are transported out of the Zhujiang (excluding the Delta Region), averaged for the period 1958-2002. Changes in water chemistry can be observed from long-term trend analysis, notably for SO42- and Cl-, as a result of anthropogenic influences, such as acid deposition, domestic and industrial wastewater discharge, and basin water resource development. An intense reforestation policy coupled with rapid reservoir development in the Zhujiang Basin would trigger more significant anthropogenic impacts on water chemistry in the future.

  10. Ground- and Surface-Water Chemistry of Handcart Gulch, Park County, Colorado, 2003-2006

    USGS Publications Warehouse

    Verplanck, Philip L.; Manning, Andrew H.; Kimball, Briant A.; McCleskey, R. Blaine; Runkel, Robert L.; Caine, Jonathan Saul; Adams, Monique; Gemery-Hill, Pamela A.; Fey, David L.

    2008-01-01

    As part of a multidisciplinary project to determine the processes that control ground-water chemistry and flow in mineralized alpine environments, ground- and surface-water samples from Handcart Gulch, Colorado were collected for analysis of inorganic solutes and water and dissolved sulfate stable isotopes in selected samples. The primary aim of this study was to document variations in ground-water chemistry in Handcart Gulch and to identify changes in water chemistry along the receiving stream of Handcart Gulch. Water analyses are reported for ground-water samples collected from 12 wells in Handcart Gulch, Colorado. Samples were collected between August 2003 and October 2005. Water analyses for surface-water samples are reported for 50 samples collected from Handcart Gulch and its inflows during a low-flow tracer injection on August 6, 2003. In addition, water analyses are reported for three other Handcart Gulch stream samples collected in September 2005 and March 2006. Reported analyses include field parameters (pH, specific conductance, temperature, dissolved oxygen, and Eh), major and trace constituents, oxygen and hydrogen isotopic composition of water and oxygen and sulfur isotopic composition of dissolved sulfate. Ground-water samples from this study are Ca-SO4 type and range in pH from 2.5 to 6.8. Most of the samples (75 percent) have pH values between 3.3 and 4.3. Surface water samples are also Ca-SO4 type and have a narrower range in pH (2.7?4.0). Ground- and surface-water samples vary from relatively dilute (specific conductance of 68 ?S/cm) to concentrated (specific conductance of 2,000 ?S/cm).

  11. Removal of sediment and bacteria from water using green chemistry.

    PubMed

    Buttice, Audrey L; Stroot, Joyce M; Lim, Daniel V; Stroot, Peter G; Alcantar, Norma A

    2010-05-01

    Although nearly all newly derived water purification methods have improved the water quality in developing countries, few have been accepted and maintained for long-term use. Field studies indicate that the most beneficial methods use indigenous resources, as they are both accessible and accepted by communities they help. In an effort to implement a material that will meet community needs, two fractions of mucilage gum were extracted from the Opuntia ficus-indica cactus and tested as flocculation agents against sediment and bacterial contamination. As diatomic ions are known to affect both mucilage and promote cell aggregation, CaCl(2) was studied in conjunction and compared with mucilage as a bacteria removal method. To evaluate performance, ion-rich waters that mimic natural water bodies were prepared. Column tests containing suspensions of the sediment kaolin exhibited particle flocculation and settling rates up to 13.2 cm/min with mucilage versus control settling rates of 0.5 cm/min. Bacillus cereus tests displayed flocculation and improved settling times with mucilage concentrations lower than 5 ppm and removal rates between 97 and 98% were observed for high bacteria concentration tests (>10(8) cells/ml). This natural material not only displays water purification abilities, but it is also affordable, renewable and readily available. PMID:20369814

  12. Aluminum in acidic surface waters: chemistry, transport, and effects.

    PubMed Central

    Driscoll, C T

    1985-01-01

    Ecologically significant concentrations of Al have been reported in surface waters draining "acid-sensitive" watersheds that are receiving elevated inputs of acidic deposition. It has been hypothesized that mineral acids from atmospheric deposition have remobilized Al previously precipitated within the soil during soil development. This Al is then thought to be transported to adjacent surface waters. Dissolved mononuclear Al occurs as aquo Al, as well as OH-, F-, SO4(2-), and organic complexes. Although past investigations have often ignored non-hydroxide complexes of Al, it appears that organic and F complexes are the predominant forms of Al in dilute (low ionic strength) acidic surface waters. The concentration of inorganic forms of Al increases exponentially with decreases in solution pH. This response is similar to the theoretical pH dependent solubility of Al mineral phases. The concentration of organic forms of Al, however, is strongly correlated with variations in organic carbon concentration of surface waters rather than pH. Elevated concentrations of Al in dilute acidic waters are of interest because: Al is an important pH buffer; Al may influence the cycling of important elements like P, organic carbon, and trace metals; and Al is potentially toxic to aquatic organisms. An understanding of the aqueous speciation of Al is essential for an evaluation of these processes. PMID:3935428

  13. Coagulation chemistries for silica removal from cooling tower water.

    SciTech Connect

    Nyman, May Devan; Altman, Susan Jeanne; Stewart, Tom

    2010-02-01

    The formation of silica scale is a problem for thermoelectric power generating facilities, and this study investigated the potential for removal of silica by means of chemical coagulation from source water before it is subjected to mineral concentration in cooling towers. In Phase I, a screening of many typical as well as novel coagulants was carried out using concentrated cooling tower water, with and without flocculation aids, at concentrations typical for water purification with limited results. In Phase II, it was decided that treatment of source or make up water was more appropriate, and that higher dosing with coagulants delivered promising results. In fact, the less exotic coagulants proved to be more efficacious for reasons not yet fully determined. Some analysis was made of the molecular nature of the precipitated floc, which may aid in process improvements. In Phase III, more detailed study of process conditions for aluminum chloride coagulation was undertaken. Lime-soda water softening and the precipitation of magnesium hydroxide were shown to be too limited in terms of effectiveness, speed, and energy consumption to be considered further for the present application. In Phase IV, sodium aluminate emerged as an effective coagulant for silica, and the most attractive of those tested to date because of its availability, ease of use, and low requirement for additional chemicals. Some process optimization was performed for coagulant concentration and operational pH. It is concluded that silica coagulation with simple aluminum-based agents is effective, simple, and compatible with other industrial processes.

  14. Pore-water chemistry explains zinc phytotoxicity in soil.

    PubMed

    Kader, Mohammed; Lamb, Dane T; Correll, Ray; Megharaj, Mallavarapu; Naidu, Ravi

    2015-12-01

    Zinc (Zn) is a widespread soil contaminant arising from a numerous anthropogenic sources. However, adequately predicting toxicity of Zn to ecological receptors remains difficult due to the complexity of soil characteristics. In this study, we examined solid-solution partitioning using pore-water data and toxicity of Zn to cucumber (Cucumis sativus L.) in spiked soils. Pore-water effective concentration (ECx, x=10%, 20% and 50% reduction) values were negatively related to pH, indicating lower Zn pore water concentration were needed to cause phytotoxicity at high pH soils. Total dissolved zinc (Znpw) and free zinc (Zn(2+)) in soil-pore water successfully described 78% and 80.3% of the variation in relative growth (%) in the full dataset. When the complete data set was used (10 soils), the estimated EC50pw was 450 and 79.2 µM for Znpw and Zn(2+), respectively. Total added Zn, soil pore water pH (pHpw) and dissolve organic carbon (DOC) were the best predictors of Znpw and Zn(2+) in pore-water. The EC10 (total loading) values ranged from 179 to 5214 mg/kg, depending on soil type. Only pH measurements in soil were related to ECx total Zn data. The strongest relationship to ECx overall was pHca, although pHw and pHpw were in general related to Zn ECx. Similarly, when a solution-only model was used to predict Zn in shoot, DOC was negatively related to Zn in shoot, indicating a reduction in uptake/ translocation of Zn from solution with increasing DOC. PMID:26283289

  15. A review of irradiation effects on LWR core internal materials - neutron embrittlement.

    SciTech Connect

    Chopra, O. K.; Rao, A. S.

    2011-05-01

    Austenitic stainless steels (SSs) are used extensively as structural alloys in the internal components of light water reactor (LWR) pressure vessels because of their relatively high strength, ductility, and fracture toughness. However, exposure to neutron irradiation for extended periods not only changes the microstructure and microchemistry of these steels, but also degrades their fracture properties. The existing data on irradiated austenitic SSs are reviewed to determine the effects of key parameters such as material type and condition and irradiation temperature, dose, and dose rate on neutron embrittlement. Differences in the radiation-induced degradation of fracture properties between LWR and fast-reactor irradiations are also discussed. The results are used to (a) define a threshold fluence above which irradiation effects on fracture toughness of the material are significant, (b) evaluate the potential of neutron embrittlement under LWR operating conditions, and (c) assess the potential effects of voids on fracture toughness.

  16. A review of irradiation effects on LWR core internal materials - Neutron embrittlement

    NASA Astrophysics Data System (ADS)

    Chopra, O. K.; Rao, A. S.

    2011-05-01

    Austenitic stainless steels (SSs) are used extensively as structural alloys in the internal components of light water reactor (LWR) pressure vessels because of their relatively high strength, ductility, and fracture toughness. However, exposure to neutron irradiation for extended periods not only changes the microstructure and microchemistry of these steels, but also degrades their fracture properties. The existing data on irradiated austenitic SSs are reviewed to determine the effects of key parameters such as material type and condition and irradiation temperature, dose, and dose rate on neutron embrittlement. Differences in the radiation-induced degradation of fracture properties between LWR and fast-reactor irradiations are also discussed. The results are used to (a) define a threshold fluence above which irradiation effects on fracture toughness of the material are significant, (b) evaluate the potential of neutron embrittlement under LWR operating conditions, and (c) assess the potential effects of voids on fracture toughness.

  17. SPENT NUCLEAR FUEL STORAGE BASIN WATER CHEMISTRY: ELECTROCHEMICAL EVALUATION OF ALUMINUM CORROSION

    SciTech Connect

    Hathcock, D

    2007-10-30

    The factors affecting the optimal water chemistry of the Savannah River Site spent fuel storage basin must be determines in order to optimize facility efficiency, minimize fuel corrosion, and reduce overall environmental impact from long term spent nuclear fuel storage at the Savannah River Site. The Savannah River National Laboratory is using statistically designed experiments to study the effects of NO{sub 3}{sup -}, SO{sub 4}{sup 2-}, and Cl{sup -} concentrations on alloys commonly used not only as fuel cladding, but also as rack construction materials The results of cyclic polarization pitting and corrosion experiments on samples of Al 6061 and 1100 alloys will be used to construct a predictive model of the basin corrosion and its dependence on the species in the basin. The basin chemistry model and corrosion will be discussed in terms of optimized water chemistry envelope and minimization of cladding corrosion.

  18. Photocatalytic water splitting with acridine dyes: Guidelines from computational chemistry

    NASA Astrophysics Data System (ADS)

    Liu, Xiaojun; Karsili, Tolga N. V.; Sobolewski, Andrzej L.; Domcke, Wolfgang

    2016-01-01

    The photocatalytic splitting of water into Hrad and OHrad radicals in hydrogen-bonded chromophore-water complexes has been explored with computational methods for the chromophores acridine orange (AO) and benzacridine (BA). These dyes are strong absorbers within the range of the solar spectrum. It is shown that low-lying charge-transfer excited states exist in the hydrogen-bonded AOsbnd H2O and BAsbnd H2O complexes which drive the transfer of a proton from water to the chromophore, which results in AOHradsbnd OHrad or BAHradsbnd OHrad biradicals. The AOHrad and BAHrad radicals possess bright ππ∗ excited states with vertical excitation energies near 3.0 eV which are predissociated by a low-lying repulsive πσ∗ state. The conical intersections of the πσ∗ state with the ππ∗ excited states and the ground state provide a mechanism for the photodetachment of the H-atom by a second photon. Our results indicate that AO and BA are promising chromophores for water splitting with visible light.

  19. Integrating Biology, Chemistry, and Mathematics to Evaluate Global Water Problems

    ERIC Educational Resources Information Center

    Kosal, Erica; Lawrence, Carol; Austin, Rodney

    2010-01-01

    An interdisciplinary and context-driven course focused on global water issues was developed and taught at the college level. Students designed a semester-long research project, collected and analyzed data, and ultimately presented their results and conclusions to the larger community. As a result of the course, students' science literacy improved…

  20. Spatial And Temporal Variation In The Dissolved Trace Element Chemistry Of Chesapeake Bay Surface Waters

    NASA Astrophysics Data System (ADS)

    Dorval, E.; Hannigan, R.; Jones, C.

    2001-12-01

    Surface waters were collected from sea grass beds around the Chesapeake Bay of Virginia as well as from the mouths of the York, James, Potomac and Rappahannock rivers and Tangier and Smith islands. These sea grass beds represent the nursery habitats for a variety of sport fish including Spotted Sea Trout and Weakfish. Trace element ratios of fish otoliths record the unique chemistries of bodies of water in which the fish live. The data presented here represent the initial results of a "ground-truthing" investigation of the relationships between the water and otolith chemistry. Waters were collected bi-monthly (July through September) from 30 sites around the western and eastern shore of Chesapeake Bay including major tributaries and Tangier and Smith islands. Water was collected using trace metal clean procedures including filtration through a 0.45 uM filter and acidification in the field to pH < 2 with ultra-pure nitric acid. Dissolved trace element composition was measured by sector field ICP-MS. The trace element chemistry of samples show both spatial and temporal variation. Using discriminant analysis it is not possible to statistically classify samples to the respective zones (western shore, eastern shore or islands) but it is possible to separate samples from the Tangier and Smith island sites from the eastern and western shore sites. Elements that allow this classification include Ce and Th, which are found in higher concentration in the samples from the island sites than in the eastern and western shore samples. These relationships follow the trends observed in pH and dissolved oxygen likely related to a restricted flow regime between the islands and the eastern shore. Mg/Ca and Sr/Ca ratios are unique for the sea grass beds along the western shore and allow the distinction of beds located between the York and Rappahannock rivers from those between the Rappahannock and Potomac rivers. Sr and Ba concentrations are variable between sites along the eastern

  1. Water chemistry-based classification of streams and implications for restoring mined Appalachian watersheds

    SciTech Connect

    Merovich, G.T.; Stiles, J.M.; Petty, J.T.; Ziemkiewicz, P.F.; Fulton, J.B.

    2007-07-15

    We analyzed seasonal water samples from the Cheat and Tygart Valley river basins, West Virginia, USA, in an attempt to classify streams based on water chemistry in this coal-mining region. We also examined temporal variability among water samples. Principal component analysis identified two important dimensions of variation in water chemistry. This variation was determined largely by mining-related factors (elevated metals, sulfates, and conductivity) and an alkalinity-hardness gradient. Cluster analysis grouped water samples into six types that we described as reference, soft, hard, transitional, moderate acid mine drainage, and severe acid mine drainage. These types were statistically distinguishable in multidimensional space. Classification tree analysis confirmed that chemical constituents related to acid mine drainage and acid rain distinguished these six groups. Hard, soft, and severe acid mine drainage type streams were temporally constant compared to streams identified as reference, transitional, and moderate acid mine drainage type, which had a greater tendency to shift to a different water type between seasons. Our research is the first to establish a statistically supported stream classification system in mined watersheds. The results suggest that human-related stressors superimposed on geology are responsible for producing distinct water quality types in this region as opposed to more continuous variation in chemistry that would be expected in an unimpacted setting. These findings provide a basis for simplifying stream monitoring efforts, developing generalized remediation strategies, and identifying specific remediation priorities in mined Appalachian watersheds.

  2. Incorporating landscape characteristics in a distance metric for interpolating between observations of stream water chemistry

    NASA Astrophysics Data System (ADS)

    Lyon, S. W.; Seibert, J.; Lembo, A. J.; Steenhuis, T. S.; Walter, M. T.

    2008-06-01

    Spatial patterns of water chemistry along stream networks can be quantified using synoptic or "snapshot" sampling. The basic idea is to sample stream water at many points over a relatively short period of time. Even for intense sampling campaigns, the number of sample points is limited and interpolation methods, like kriging, are commonly used to produce continuous maps of water chemistry based on the point observations from the synoptic sampling. Interpolated concentrations are influenced heavily by how distance between points along the stream network is defined. In this study, we investigate different ways to define distance and test these based on data from a snapshot sampling campaign in a 37-km2 watershed in the Catskill Mountains region (New York State). Three distance definitions (or metrics) were compared: Euclidean or straight-line distance, in-stream distance, and in-stream distance adjusted according characteristics of the local contributing area, i.e., an adjusted in-stream distance. Using the adjusted distance metric resulted in a lower cross-validation error of the interpolated concentrations, i.e., a better agreement of kriging results with measurements, than the other distance definitions. The adjusted distance metric can also be used in an exploratory manner to test which landscape characteristics are most influential for the spatial patterns of stream water chemistry and, thus, to target future investigations to gain process-based understanding of in-stream chemistry dynamics.

  3. Incorporating landscape characteristics in a distance metric for interpolating between observations of stream water chemistry

    NASA Astrophysics Data System (ADS)

    Lyon, S. W.; Seibert, J.; Lembo, A. J.; Steenhuis, T. S.; Walter, M. T.

    2008-10-01

    Spatial patterns of water chemistry along stream networks can be quantified using synoptic or "snapshot" sampling. The basic idea is to sample stream water at many points over a relatively short period of time. Even for intense sampling campaigns, the number of sample points is limited and interpolation methods, like kriging, are commonly used to produce continuous maps of water chemistry based on the point observations from the synoptic sampling. Interpolated concentrations are influenced heavily by how distance between points along the stream network is defined. In this study, we investigate different ways to define distance and test these based on data from a snapshot sampling campaign in a 37-km2 watershed in the Catskill Mountains region (New York State). Three distance definitions (or metrics) were compared: Euclidean or straight-line distance, in-stream distance, and in-stream distance adjusted according characteristics of the local contributing area, i.e., an adjusted in-stream distance. Using the adjusted distance metric resulted in a lower cross-validation error of the interpolated concentrations, i.e., a better agreement of kriging results with measurements, than the other distance definitions. The adjusted distance metric can also be used in an exploratory manner to test which landscape characteristics are most influential for the spatial patterns of stream water chemistry and, thus, to target future investigations to gain process-based understanding of in-stream chemistry dynamics.

  4. Role(s) of adsorbed water in the surface chemistry of environmental interfaces.

    PubMed

    Rubasinghege, Gayan; Grassian, Vicki H

    2013-04-18

    The chemistry of environmental interfaces such as oxide and carbonate surfaces under ambient conditions of temperature and relative humidity is of great interest from many perspectives including heterogeneous atmospheric chemistry, heterogeneous catalysis, photocatalysis, sensor technology, corrosion science, and cultural heritage science. As discussed here, adsorbed water plays important roles in the reaction chemistry of oxide and carbonate surfaces with indoor and outdoor pollutant molecules including nitrogen oxides, sulfur dioxide, carbon dioxide, ozone and organic acids. Mechanisms of these reactions are just beginning to be unraveled and found to depend on the details of the reaction mechanism as well as the coverage of water on the surface. As discussed here, adsorbed water can: (i) alter reaction pathways and surface speciation relative to the dry surface; (ii) hydrolyze reactants, intermediates and products; (iii) enhance surface reactivity by providing a medium for ionic dissociation; (iv) inhibit surface reactivity by blocking sites; (v) solvate ions; (vi) enhance ion mobility on surfaces and (vii) alter the stability of surface adsorbed species. In this feature article, drawing on research that has been going on for over a decade on the reaction chemistry of oxide and carbonate surfaces under ambient conditions of temperature and relative humidity, a number of specific examples showing the multi-faceted roles of adsorbed water are presented. PMID:23417201

  5. Pesticides in Drinking Water: Project-based Learning within the Introductory Chemistry Curriculum.

    ERIC Educational Resources Information Center

    O'Hara, Patricia B.; Sanborn, Jon A.; Howard, Meredith

    1999-01-01

    Describes a four-week laboratory module for an introductory chemistry course that focuses on the analysis of trace levels of xenoestrogenic pesticides in local drinking water and a comparison of the molecular shapes of these pesticides to the hormone estrogen. (WRM)

  6. Water chemistry responses to hydraulic manipulation of an agricultural wetland

    NASA Astrophysics Data System (ADS)

    Powers, S.; Stanley, E. H.

    2011-12-01

    Small impoundments are often crucial factors for the movement of sediment, organic matter, water-borne nutrients, and toxic materials through river networks. By recent accounting, at least 2.6 million small artificial water bodies exist in the US alone. A large proportion of those structures occur in regions with high intensity of agriculture, such as in the Midwestern grain belt. While small impoundments are aging structures which appear to serve few purposes, some hold ecological and biogeochemical value as artificial wetlands. We documented instantaneous net fluxes of solute (chloride, sulfate, nitrate, ammonium, and soluble reactive phosphorus) through an artificial flow-through wetland in agricultural southern Wisconsin over 6 years which spanned removal of a small dam. Phased dewatering and dam removal ultimately converted the artificial wetland to a canal-like state (increase in mean water velocity from 0.08 to 0.22 m s-1). Mean net flux for chloride across the system averaged nearly 0 g d-1, indicating conservative transport and successful characterization of hydrology. In contrast, net fluxes for other solute forms were altered following loss of the wetland: a persistent net sulfate sink (5-10% of inputs retained), suggestive of sulfate-reducing bacteria, was reduced; seasonal (summer) net sinks for nitrate and ammonium, suggestive of uptake by algae and denitrifying bacteria, were reduced; temporal variability for the net flux of soluble reactive phosphorus was reduced. Overall, loss of the artificial wetland caused by dam removal shifted seasonal and annual net fluxes of biologically available solute toward export. Nutrient retention by artificial wetlands could be important for elemental budgets in regions which have high nutrient loading to surface and ground water.

  7. Ground-water, surface-water, and water-chemistry data, Black Mesa area, northeastern Arizona: 1998

    USGS Publications Warehouse

    Truini, Margot; Baum, Bradley M.; Littin, Gregory R.; Shingoitewa-Honanie, Gayl

    2000-01-01

    The Black Mesa monitoring program is designed to document long-term effects of ground-water pumping from the N aquifer by industrial and municipal users. The N aquifer is the major source of water in the 5,400-square-mile Black Mesa area, and the ground water occurs under confined and unconfined conditions. Monitoring activities include continuous and periodic measurements of (1) ground-water pumpage from the confined and unconfined parts of the aquifer, (2) ground-water levels in the confined and unconfined parts of the aquifer, (3) surface-water discharge, (4) flowmeter tests, and (5) ground-water and surface-water chemistry. In 1998, ground-water withdrawals for industrial and municipal use totaled about 7,060 acre-feet, which is less than a 1 percent decrease from 1997. Pumpage from the confined part of the aquifer decreased by less than 1 percent to 5,470 acre-feet, and pumpage from the unconfined part of the aquifer increased by less than 1 percent to 1,590 acre-feet. Water-level declines in the confined part of the aquifer were recorded in 10 of 14 wells during 1998, and the median change from 1997 was a decline of 3.0 feet as opposed to a rise of 0.2 feet for the change from 1996 to 1997. Water-level declines in the unconfined part of the aquifer were recorded in 9 of 16 wells, and the median change from 1997 was 0.0 feet, which is the same as the median change from 1996 to 1997. Of the 35 pumpage meters on municipal wells that were tested, the difference between metered and tested discharge ranged from +6.3 to -19.6 percent. The average difference was about -3.4 percent. Five of the meters exceeded the allowable difference (10 percent) and should be repaired or replaced. The low-flow discharge at the Moenkopi streamflow-gaging station ranged from 2.6 to 4.7 cubic feet per second in 1998. Streamflow-discharge measurements also were made at Laguna Creek, Dinnebito Wash, and Polacca Wash during 1998. The low-flow discharge ranged from 0.41 to 5.1 cubic feet

  8. Random Phase Approximation in Surface Chemistry: Water Splitting on Iron.

    PubMed

    Karlický, František; Lazar, Petr; Dubecký, Matúš; Otyepka, Michal

    2013-08-13

    The reaction of water with zero-valent iron (anaerobic corrosion) is a complex chemical process involving physisorption and chemisorption events. We employ random phase approximation (RPA) along with gradient-corrected and hybrid density functional theory (DFT) functionals to study the reaction of water with the Fe atom and Fe(100) surface. We show that the involvement of the exact electron exchange and nonlocal correlation effects in RPA improves the description of all steps of the reaction on the Fe surface with respect to standard [meaning local density approximation (LDA) or generalized gradient approximation (GGA)] DFT methods. The reaction profile calculated by range-separated hybrid functional HSE06 agrees reasonably well with the RPA profile, which makes HSE06 a computationally less demanding alternative to RPA. We also investigate the reaction of the Fe atom with water using DFT, RPA, and coupled-cluster through the perturbative triples complete basis set [CCSD(T)-3s3p-DKH/CBS] method. Local DFT methods significantly underestimate reaction barriers, while the reaction kinetics and thermodynamics from RPA agree with the reference CCSD(T) data. Both systems, i.e., the Fe atom and Fe(100), provide the same reaction mechanism, indicating that anaerobic corrosion is a stepwise process involving one-electron steps, with the first reaction step (formation of the HFeOH intermediate) representing the rate-limiting step. PMID:26584120

  9. Governing chemistry of cellulose hydrolysis in supercritical water.

    PubMed

    Cantero, Danilo A; Bermejo, M Dolores; Cocero, M José

    2015-03-01

    At extremely low reaction times (0.02 s), cellulose was hydrolyzed in supercritical water (T=400 °C and P=25 MPa) to obtain a sugar yield higher than 95 wt%, whereas the 5-hydroxymethylfurfural (5-HMF) yield was lower than 0.01 wt %. If the reaction time was increased to 1 s, the main product was glycolaldehyde (60 wt%). Independently of the reaction time, the yield of 5-HMF was always lower than 0.01 wt%. To evaluate the reaction mechanism of biomass hydrolysis in pressurized water, several parameters (temperature, pressure, reaction time, and reaction medium) were studied for different biomasses (cellulose, glucose, fructose, and wheat bran). It was found that the H(+) and OH(-) ion concentration in the reaction medium as a result of water dissociation is the determining factor in the selectivity. The reaction of glucose isomerization to fructose and the further dehydration to 5-HMF are highly dependent on the ion concentration. By an increase in the pOH/pH value, these reactions were minimized to allow control of 5-HMF production. Under these conditions, the retroaldol condensation pathway was enhanced, instead of the isomerization/dehydration pathway. PMID:25704124

  10. Ground-Water, Surface-Water, and Water-Chemistry Data, Black Mesa Area, Northeastern Arizona - 2006-07

    USGS Publications Warehouse

    Truini, Margot; Macy, J.P.

    2008-01-01

    The N aquifer is the major source of water in the 5,400 square-mile Black Mesa area in northeastern Arizona. Availability of water is an important issue in northeastern Arizona because of continued water requirements for industrial and municipal use and the needs of a growing population. Precipitation in the Black Mesa area is typically about 6 to 14 inches per year. The water-monitoring program in the Black Mesa area began in 1971 and is designed to provide information about the long-term effects of ground-water withdrawals from the N aquifer for industrial and municipal uses. This report presents results of data collected for the monitoring program in the Black Mesa area from January 2006 to September 2007. The monitoring program includes measurements of (1) ground-water withdrawals, (2) ground-water levels, (3) spring discharge, (4) surface-water discharge, and (5) ground-water chemistry. Periodic testing of ground-water withdrawal meters is completed every 4 to 5 years. The Navajo Tribal Utility Authority (NTUA) yearly totals for the ground-water metered withdrawal data were unavailable in 2006 due to an up-grade within the NTUA computer network. Because NTUA data is often combined with Bureau of Indian Affairs data for the total withdrawals in a well system, withdrawals will not be published in this year's annual report. From 2006 to 2007, annually measured water levels in the Black Mesa area declined in 3 of 11 wells measured in the unconfined areas of the N aquifer, and the median change was 0.0 feet. Measurements indicated that water levels declined in 8 of 17 wells measured in the confined area of the aquifer. The median change for the confined area of the aquifer was 0.2 feet. From the prestress period (prior to 1965) to 2007, the median water-level change for 30 wells was -11.1 feet. Median water-level changes were 2.9 feet for 11 wells measured in the unconfined areas and -40.2 feet for 19 wells measured in the confined area. Spring flow was measured

  11. Chemistry of thermal waters and mineralogy of the new deposits at Mount St. Helens: a preliminary report

    SciTech Connect

    Dethier, D.P.; Frank, D.; Peavear, D.R.

    1980-12-01

    After May 18, 1980 eruption of Mount St. Helens, Washington, interactions between the hot deposits and shallow ground water produced ephemeral phreatic eruptions and thermal ponds and streams. In early June water and sediment samples were collected from about 20 sites in the devastated zone to study the initial alteration of the new deposits, and the effects of the eruption on water chemistry. The levels of certain trace elements in thermal waters, and whether these mineralized waters were reaching the North Fork Toutle River in appreciable quantities were studied. Collection and analysis procedures, the mineralogy of the new deposits, and the chemistry of the thermal waters are discussed. Finally, the chemistry of water from different deposits is compared, alteration reactions suggested by the water chemistry, and the mineralogy of the deposits is discussed.

  12. NUCLEAR CHEMISTRY OF WATER-COOLED FUSION REACTORS: ISSUES AND SOLUTIONS

    SciTech Connect

    Petrov, Andrei Y; Flanagan, George F

    2010-01-01

    ITER is an experimental Tokamak fusion energy reactor that is being built in Cadarache, France, in collaboration with seven agencies representing China, the European Union, India, Japan, Republic of Korea, the Russian Federation, and the United States. The main objective of ITER is to demonstrate the scientific and technical feasibility of a controlled fusion reaction An important U.S. contribution is the design, fabrication, and delivery of the Tokamak Cooling Water System (TCWS). This paper describes the main sources of radioactivity in TCWS water, which are the nitrogen isotopes 16N and 17N, tritium, activated corrosion products, and the carbon isotope 14C; the relative contribution of each of these sources to the total radioactive contamination of water; issues related to excess accumulation of these species; and methods to control TCWS radioactivity within acceptable limits. Among these methods are: (1) water purification to minimize corrosion of materials in contact with TCWS water; (2) monitoring of vital chemistry parameters and control of water chemistry; (3) design of proper building structure and/or TCWS loop/geometry configuration; and (4) design of an ITER liquid radwaste facility tailored to TCWS operational requirements. Design of TCWS nuclear chemistry control is crucial to ensuring that the inventory of radioactive species is consistent with the principle of 'As Low as Reasonably Achievable.'

  13. Kinugasa reactions in water: from green chemistry to bioorthogonal labelling.

    PubMed

    Chigrinova, Mariya; MacKenzie, Douglas A; Sherratt, Allison R; Cheung, Lawrence L W; Pezacki, John Paul; Pezacki, Paul

    2015-01-01

    The Kinugasa reaction has become an efficient method for the direct synthesis of β-lactams from substituted nitrones and copper(I) acetylides. In recent years, the reaction scope has been expanded to include the use of water as the solvent, and with micelle-promoted [3+2] cycloadditions followed by rearrangement furnishing high yields of β-lactams. The high yields of stable products under aqueous conditions render the modified Kinugasa reaction amenable to metabolic labelling and bioorthogonal applications. Herein, the development of methods for use of the Kinugasa reaction in aqueous media is reviewed, with emphasis on its potential use as a bioorthogonal coupling strategy. PMID:25913933

  14. Ground-Water, Surface-Water, and Water-Chemistry Data, Black Mesa Area, Northeastern Arizona-2005-06

    USGS Publications Warehouse

    Truini, Margot; Macy, J.P.

    2007-01-01

    The N aquifer is the major source of water in the 5,400 square-mile Black Mesa area in northeastern Arizona. Availability of water is an important issue in northeastern Arizona because of continued water requirements for industrial and municipal use and the needs of a growing population. Precipitation in the Black Mesa area averages about 6 to 14 inches per year. The water monitoring program in the Black Mesa area began in 1971 and is designed to provide information about the long-term effects of ground-water withdrawals from the N aquifer for industrial and municipal uses. This report presents results of data collected for the monitoring program in the Black Mesa area from January 2005 to September 2006. The monitoring program includes measurements of (1) ground-water pumping, (2) ground-water levels, (3) spring discharge, (4) surface-water discharge, (5) ground-water chemistry, and (6) periodic testing of ground-water withdrawal meters. In 2005, ground-water withdrawals in the Black Mesa area totaled 7,330 acre-feet, including ground-water withdrawals for industrial (4,480 acre-feet) and municipal (2,850 acre-feet) uses. From 2004 to 2005, total withdrawals increased by less than 2 percent, industrial withdrawals increased by approximately 3 percent, and total municipal withdrawals increased by 0.35 percent. From 2005 to 2006, annually measured water levels in the Black Mesa area declined in 10 of 13 wells in the unconfined areas of the N aquifer, and the median change was -0.5 foot. Measurements indicated that water levels declined in 12 of 15 wells in the confined area of the aquifer, and the median change was -1.4 feet. From the prestress period (prior to 1965) to 2006, the median water-level change for 29 wells was -8.5 feet. Median water-level changes were -0.2 foot for 13 wells in the unconfined areas and -46.6 feet for 16 wells in the confined area. Ground-water discharges were measured once in 2005 and once in 2006 at Moenkopi School Spring and Burro

  15. Changes in water chemistry can disable plankton prey defenses

    PubMed Central

    Riessen, Howard P.; Linley, Robert Dallas; Altshuler, Ianina; Rabus, Max; Söllradl, Thomas; Clausen-Schaumann, Hauke; Laforsch, Christian; Yan, Norman D.

    2012-01-01

    The effectiveness of antipredator defenses is greatly influenced by the environment in which an organism lives. In aquatic ecosystems, the chemical composition of the water itself may play an important role in the outcome of predator–prey interactions by altering the ability of prey to detect predators or to implement defensive responses once the predator’s presence is perceived. Here, we demonstrate that low calcium concentrations (<1.5 mg/L) that are found in many softwater lakes and ponds disable the ability of the water flea, Daphnia pulex to respond effectively to its predator, larvae of the phantom midge, Chaoborus americanus. This low-calcium environment prevents development of the prey’s normal array of induced defenses, which include an increase in body size, formation of neck spines, and strengthening of the carapace. We estimate that this inability to access these otherwise effective defenses results in a 50–186% increase in the vulnerability of the smaller juvenile instars of Daphnia, the stages most susceptible to Chaoborus predation. Such a change likely contributes to the observed lack of success of daphniids in most low-calcium freshwater environments, and will speed the loss of these important zooplankton in lakes where calcium levels are in decline. PMID:22949653

  16. Groundwater chemistry and water-rock interactions at Stripa

    USGS Publications Warehouse

    Nordstrom, D.K.; Ball, J.W.; Donahoe, R.J.; Whittemore, D.

    1989-01-01

    Groundwaters from near surface to a depth of 1232 m in the Stripa granite have been sampled and analyzed for major and trace constituents. The groundwater composition consists of two general types: a typical recharge water of Ca-HCO3 type (700 m depth) of high pH (8-10) that reaches a maximum of 1250 mg/L in total dissolved solids (TDS). Intermediate depths show mixtures of the two types that are highly fracture-dependent rather than depth-dependent. Any borehole can vary significantly and erratically in TDS for either a horizontal or vertical direction. The general transition from Ca-HCO3 type to Na-Ca-Cl type correlates with the depth profile for hydraulic conductivity that drops from 10-8 m/s to 10-11 m/s or lower. Thermomechanical stress (from heater experiments) clearly shows an effect on the groundwater composition that could be caused by changing flow paths, leakage of fluid inclusions or both. Dissolution and precipitation of calcite, fluorite and barite, aluminosilicate hydrolysis, and addition of a saline source (possibly fluid inclusion leakage) play the major roles in defining the groundwater composition. The low permeability of the Stripa granite has produced a groundwater composition that appears intermediate between the dilute, shallow groundwaters typical of recharge in a crystalline rock terrain and the saline waters and brines typical of cratonic shield areas at depth. ?? 1989.

  17. A spatial and seasonal assessment of river water chemistry across North West England.

    PubMed

    Rothwell, J J; Dise, N B; Taylor, K G; Allott, T E H; Scholefield, P; Davies, H; Neal, C

    2010-01-15

    This paper presents information on the spatial and seasonal patterns of river water chemistry at approximately 800 sites in North West England based on data from the Environment Agency regional monitoring programme. Within a GIS framework, the linkages between average water chemistry (pH, sulphate, base cations, nutrients and metals) catchment characteristics (topography, land cover, soil hydrology, base flow index and geology), rainfall, deposition chemistry and geo-spatial information on discharge consents (point sources) are examined. Water quality maps reveal that there is a clear distinction between the uplands and lowlands. Upland waters are acidic and have low concentrations of base cations, explained by background geological sources and land cover. Localised high concentrations of metals occur in areas of the Cumbrian Fells which are subjected to mining effluent inputs. Nutrient concentrations are low in the uplands with the exception sites receiving effluent inputs from rural point sources. In the lowlands, both past and present human activities have a major impact on river water chemistry, especially in the urban and industrial heartlands of Greater Manchester, south Lancashire and Merseyside. Over 40% of the sites have average orthophosphate concentrations >0.1mg-Pl(-1). Results suggest that the dominant control on orthophosphate concentrations is point source contributions from sewage effluent inputs. Diffuse agricultural sources are also important, although this influence is masked by the impact of point sources. Average nitrate concentrations are linked to the coverage of arable land, although sewage effluent inputs have a significant effect on nitrate concentrations. Metal concentrations in the lowlands are linked to diffuse and point sources. The study demonstrates that point sources, as well as diffuse sources, need to be considered when targeting measures for the effective reduction in river nutrient concentrations. This issue is clearly important

  18. Martian atmospheric chemistry during the time of low water abundance

    NASA Technical Reports Server (NTRS)

    Nair, Hari; Allen, Mark; Yung, Yuk L.; Clancy, R. Todd

    1992-01-01

    The importance of odd hydrogen (or HO(x)) radicals in the catalytic recombination of carbon monoxide and oxygen in the Martian atmosphere is a well known fact. The inclusion of recent chemical kinetics data, specifically temperature-dependent CO2 absorption cross sections, into our one dimensional photochemical model shows that HO(x) is too efficient in this regard. The absorption cross sections of CO2 are smaller than previously assumed; this leads to a reduction in the photolysis rate of CO2 while the photolysis rate of H2O has increased. As a consequence the predicted mixing ratio of CO in our models is substantially less than the observed value of 6.5(10)(exp -4). Simultaneous measurements of water, ozone, and carbon monoxide were obtained in the Martian atmosphere in early Dec. 1990 (L(sub s) for Mars was 344 deg.).

  19. Chemistry and nanoparticulate compositions of a 10,000 year-old ice core melt water.

    PubMed

    Murr, L E; Esquivel, E V; Bang, J J; de la Rosa, G; Gardea-Torresdey, J L

    2004-11-01

    Particulates extracted from a single section of a 10,000 year-old ice core melt sample exhibited characteristics of contemporary, airborne fine particulates: a majority were microcrystalline particulates and aggregated microcrystals, including some mixtures of microcrystals and carbonaceous matter. Particularly significant were the presence of carbon nanotubes and fullerene nanocrystals composing aggregated particulates reflecting global combustion products similar to contemporary, airborne carbon nanocrystal aggregates. ICP elemental analysis of the melt water showed significant concentrations of Ca, K and especially Na (corresponding to K, NaCl), S, Si, Se, and Zn. Overall, the elemental analysis of the melt water is similar to local tap water. However, lead was absent in the local tap water and only half the concentration of selenium was present in the tap water in contrast to the ice core water. While these observations cannot be generalized, the methodology illustrates the potential to characterize and compare airborne particulate regimes and water chemistries in antiquity. PMID:15491674

  20. Dominant processes controlling water chemistry of the Pecos River in American southwest

    NASA Astrophysics Data System (ADS)

    Yuan, Fasong; Miyamoto, Seiichi

    2005-09-01

    Here we show an analysis of river flow and water chemistry data from eleven gauging stations along the Pecos River in eastern New Mexico and western Texas, with time spanning 1959-2002. Analysis of spatial relationship between the long-term average flow and total dissolved solids (TDS) concentration allows us to illuminate four major processes controlling river chemistry, namely saline water addition, evaporative concentration with salt gain or loss, dilution with salt gain or loss, and salt storage. Of the 10 river reaches studied, six reaches exhibit the process dominated by evaporative concentration or freshwater dilution with little change in salt load. Four reaches show considerable salt gains or losses that are induced by surface-ground water interactions. This analysis suggests that the evaporative concentration and freshwater dilution are the prevailing mechanisms, but local processes (e.g., variations in hydrologic flowpath and lithologic formation) also play an important role in regulating the hydrochemistry of the Pecos River.

  1. Variation in water chemistry parameters in the Clayburn Creek watershed, British Columbia during fall 2015.

    NASA Astrophysics Data System (ADS)

    Marsh, S. J.; Gillies, S. L.; Peucker-Ehrenbrink, B.; Janmaat, A.; Clemence, E.; Faber, A.; Yakemchuk, A.; McCabe, M.; Toner, A.; Strangway, A.; Turner, S.; Sidhu, D.; Sidhu, B.; Sekhton, J.; Puri, K.; Paulson, D.; Mahil, G.; Leffers, R.; Kanda, S.; Gaultier, M.; Dhaliwal, H.

    2015-12-01

    faculty and students from the University of the Fraser Valley have conducted the time series sampling of water chemistry of the Fraser River at Fort Langley and five Fraser Valley tributaries as a member of the Global Rivers Observatory (GRO, www.globalrivers.org) organized by Woods Hole Oceanographic Institution and Woods Hole Research Center. Clayburn Creek and Willband Creek in Abbotsford, British Columbiahave been part of this project and have been sampled for nutrient and major ion concentrations and parameters such as water temperature, dissolved oxygen, conductivity, pH and turbidity. This watershed is being threatened by increasing anthropogenic activity (agricultural, industrial and residential development) that may threaten the salmon that spawn in this watershed. Documenting the change in the water chemistry in this watershed as the seasons progress from a dry summer to a wet fall will yield a greater understanding of our impact on this watershed and may assist our attempts to protect this watershed.

  2. Vertical Gradients in Water Chemistry and Age in the Northern High Plains Aquifer, Nebraska, 2003

    USGS Publications Warehouse

    McMahon, P.B.; Böhlke, J.K.; Carney, C.P.

    2007-01-01

    The northern High Plains aquifer is the primary source of water used for domestic, industrial, and irrigation purposes in parts of Colorado, Kansas, Nebraska, South Dakota, and Wyoming. Despite the aquifer's importance to the regional economy, fundamental ground-water characteristics, such as vertical gradients in water chemistry and age, remain poorly defined. As part of the U.S. Geological Survey's National Water-Quality Assessment Program, water samples from nested, short-screen monitoring wells installed in the northern High Plains aquifer were analyzed for major ions, nutrients, trace elements, dissolved organic carbon, pesticides, stable and radioactive isotopes, dissolved gases, and other parameters to evaluate vertical gradients in water chemistry and age in the aquifer. Chemical data and tritium and radiocarbon ages show that water in the aquifer was chemically and temporally stratified in the study area, with a relatively thin zone of recently recharged water (less than 50 years) near the water table overlying a thicker zone of older water (1,800 to 15,600 radiocarbon years). In areas where irrigated agriculture was an important land use, the recently recharged ground water was characterized by elevated concentrations of major ions and nitrate and the detection of pesticide compounds. Below the zone of agricultural influence, major-ion concentrations exhibited small increases with depth and distance along flow paths because of rock/water interactions. The concentration increases were accounted for primarily by dissolved calcium, sodium, bicarbonate, sulfate, and silica. In general, the chemistry of ground water throughout the aquifer was of high quality. None of the approximately 90 chemical constituents analyzed in each sample exceeded primary drinking-water standards. Mass-balance models indicate that changes in ground-water chemistry along flow paths in the aquifer can be accounted for by small amounts of feldspar and calcite dissolution; goethite and

  3. Water chemistry of a combined-cycle power plant's auxiliary equipment cooling system

    NASA Astrophysics Data System (ADS)

    Larin, B. M.; Korotkov, A. N.; Oparin, M. Yu.; Larin, A. B.

    2013-04-01

    Results from an analysis of methods aimed at reducing the corrosion rate of structural metal used in heat-transfer systems with water coolant are presented. Data from examination of the closed-circuit system for cooling the auxiliary mechanisms of a combined-cycle plant-based power unit and the results from adjustment of its water chemistry are given. A conclusion is drawn about the possibility of using a reagent prepared on the basis of sodium sulfite for reducing the corrosion rate when the loss of coolant is replenished with nondeaerated water.

  4. Geohydrological characterization, water-chemistry, and ground-water flow simulation model of the Sonoma Valley area, Sonoma County, California

    USGS Publications Warehouse

    Farrar, Christopher D.; Metzger, Loren F.; Nishikawa, Tracy; Koczot, Kathryn M.; Reichard, Eric G.; Langenheim, V.E.

    2006-01-01

    The Sonoma Valley, located about 30 miles north of San Francisco, is one of several basins in Sonoma County that use a combination of ground water and water delivered from the Russian River for supply. Over the past 30 years, Sonoma Valley has experienced rapid population growth and land-use changes. In particular, there has been a significant increase in irrigated agriculture, predominantly vineyards. To provide a better understanding of the ground-water/surface-water system in Sonoma Valley, the U.S. Geological Survey compiled and evaluated existing data, collected and analyzed new data, and developed a ground-water flow model to better understand and manage the ground-water system. The new data collected include subsurface lithology, gravity measurements, groundwater levels, streamflow gains and losses, temperature, water chemistry, and stable isotopes. Sonoma Valley is drained by Sonoma Creek, which discharges into San Pablo Bay. The long-term average annual volume of precipitation in the watershed is estimated to be 269,000 acre-feet. Recharge to the ground-water system is primarily from direct precipitation and Sonoma Creek. Discharge from the ground-water system is predominantly outflow to Sonoma Creek, pumpage, and outflow to marshlands and to San Pablo Bay. Geologic units of most importance for groundwater supply are the Quaternary alluvial deposits, the Glen Ellen Formation, the Huichica Formation, and the Sonoma Volcanics. In this report, the ground-water system is divided into three depth-based geohydrologic units: upper (less than 200 feet below land surface), middle (between 200 and 500 feet), and lower (greater than 500 feet). Synoptic streamflow measurements were made along Sonoma Creek and indicate those reaches with statistically significant gains or losses. Changes in ground-water levels in wells were analyzed by comparing historical contour maps with the contour map for 2003. In addition, individual hydrographs were evaluated to assess temporal

  5. Six-decade change in water chemistry of large freshwater Lake Taihu, China.

    PubMed

    Tao, Yu; Yuan, Zhang; Fengchang, Wu; Wei, Meng

    2013-08-20

    Taihu lake has become a hot spot internationally due to its algae bloom. However, its natural water chemistry (major ions) received little attention though it is equally important for drinking water and aquatic ecology. Using historical data (1950s-2012) we explored the drastic change of Taihu water chemistry over the past six decades and the driving factors. Results show that major ions increased around 2-7-fold and TDS increased nearly 3-fold during the last 60 years. The dominant cation has shifted from Ca(2+) to Na(+), and the current Cl(-) is dominant over HCO3(-), the predominant anion before the 2000s. Analyses show that population increase and human activities were the major driving factors responsible for the drastic change. Whereas the mechanism of increase was different for ions, i.e., Na(+) and Cl(-) increase was directly related to the population increase and sewage discharge in the basin; SO4(2-) was related to atmospheric deposition derived from increasing coal consumption and SO2 emissions; hardness (Ca and Mg) increase was closely linked to the acidic precipitation. No increase trend of HCO3(-) was attributable to frequent outbreaks of algae bloom which consumed HCO3(-). Estimation indicated that sewage discharge in the basin contributed 23% to the lake in terms of Cl(-), exceeding the contribution from rock weathering. Current water chemistry of Taihu lake has become "anthropogenic dominance" from its original rock dominance. PMID:23875770

  6. Uranium release from sediment to groundwater: influence of water chemistry and insights into release mechanisms.

    PubMed

    Alam, Md Samrat; Cheng, Tao

    2014-08-01

    Uranium (U) contamination in groundwater often results from natural geochemical processes such as mineral dissolution and desorption of adsorbed U from mineral surface. Although U adsorption and U mineral dissolution have been extensively studied, current knowledge of minerals and water chemistry conditions that control U release in uncontaminated soil and aquifers is still limited. Identification of these minerals and the knowledge of how water chemistry conditions influence U release is critical to better understand, predict, and manage geogenic U contamination in soil and groundwater. The objective of this study is to determine the extent and mechanisms of U release from a heterogeneous natural sediment under water chemistry conditions relevant to natural soil water and groundwater. A sediment sample was collected and characterized by XRD, SEM-EDX and extraction methods, and examined using laboratory leaching experiments. Our results show that Fe-Mn (oxy)hydroxides and silicate minerals are the major U hosting minerals, and a substantial fraction of U exists as adsorbed ions on minerals. We also found that U release is controlled by a number of interactive processes including dissolution of U-bearing minerals, U desorption from mineral surface, formation of aqueous U complexes, and reductive precipitation of U. Results from this study shed light on the important geochemical reactions that need be considered for developing a conceptual model that predicts U contamination in subsurface environment. PMID:24954631

  7. Geohydrology and water-chemistry of the Alexander Valley, Sonoma County, California

    USGS Publications Warehouse

    Metzger, Loren F.; Farrar, Christopher D.; Koczot, Kathryn M.; Reichard, Eric G.

    2006-01-01

    This study of the geohydrology and water chemistry of the Alexander Valley, California, was done to provide an improved scientific basis for addressing emerging water-management issues, including potential increases in water demand and changes in flows in the Russian River. The study tasks included (1) evaluation of existing geohydrological, geophysical, and geochemical data; (2) collection and analysis of new geohydrologic data, including subsurface lithologic data, ground-water levels, and streamflow records; and (3) collection and analysis of new water-chemistry data. The estimated total water use for the Alexander Valley for 1999 was approximately 15,800 acre-feet. About 13,500 acre-feet of this amount was for agricultural use, primarily vineyards, and about 2,300 acre-feet was for municipal/industrial use. Ground water is the main source of water supply for this area. The main sources of ground water in the Alexander Valley are the Quaternary alluvial deposits, the Glen Ellen Formation, and the Sonoma Volcanics. The alluvial units, where sufficiently thick and saturated, comprise the best aquifer in the study area. Average recharge to the Alexander Valley is estimated from a simple, basinwide water budget. On the basis of an estimated annual average of 298,000 acre-feet of precipitation, 160,000 acre-feet of runoff, and 113,000 to 133,000 acre-feet of evapotranspiration, about 5,000 to 25,000 acre-feet per year is available for ground-water recharge. Because this estimate is based on differences between large numbers, there is significant uncertainty in this recharge estimate. Long-term changes in ground-water levels are evident in parts of the study area, but because of the sparse network and lack of data on well construction and lithology, it is uncertain if any significant changes have occurred in the northern part of the study area since 1980. In the southern half of the study area, ground-water levels generally were lower at the end of the 2002 irrigation

  8. Regional characters of cloud water chemistry over severe acid rain areas of China

    SciTech Connect

    Zhilai Shen; Hui Xiao; Hengchi Lei; Meiyuan Huang

    1996-12-31

    The results and discussion are presented of measurements of cloud water chemistry made over severe add rain areas, such as Chongqing, Chengdu, Guiyang, Guangzhou, Nanchang, and Changsha in China from 1985 to 1993. Analyses indicate that acid cloud water is widespread in these areas, the range of cloud water pH is large within an area, the highest acidity is not over big city, and the difference of average values of pH is not obvious in different areas. In some areas, for example Chongqing, the annual variation of average pH is large. The range of average of total ion concentrations of cloud water is also large and the maximum is six more than minimum. The relationship between the acidity and ion concentration of cloud water is unlinear. The chemistry parameters of cloud water exhibit an obvious region character in Southwest China (Chongqing, Chengdu and Guiyang) SO4= is a dominant anion and SO4=/NO3- is more than 8, Ca++ and NH4+ are the main cation, Ca++/NH4+>1 (in the remaining areas, Ca++/NH4+<1), the cloud water acidity is higher than that of ground rain, indicating that there is an acidification process below cloud. In South China (Guangzhou and Guiyang) NO3 is same important as SO4= and SO4=/NO3- is about 1. In Central China (Nanchang and Changsha) the total ion concentration is highest on comparison with other areas and the value is more than that of ground rainwater, meaning probably that there is an influence of cloud microphysical process on cloud water and rainwater chemistry.

  9. A review of the effects of coolant environments on the fatigue life of LWR structural materials.

    SciTech Connect

    Chopra, O. K.; Shack, W. J.

    2009-04-01

    The American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code specifies design curves for the fatigue life of structural materials in nuclear power plants. However, the effects of light water reactor (LWR) coolant environments were not explicitly considered in the development of the design curves. The existing fatigue-strain-versus-life ({var_epsilon}-N) data indicate potentially significant effects of LWR coolant environments on the fatigue resistance of pressure vessel and piping steels. Under certain environmental and loading conditions, fatigue lives in water relative to those in air can be a factor of 15 lower for austenitic stainless steels and a factor of {approx}30 lower for carbon and low-alloy steels. This paper reviews the current technical basis for the understanding of the fatigue of piping and pressure vessel steels in LWR environments. The existing fatigue {var_epsilon}-N data have been evaluated to identify the various material, environmental, and loading parameters that influence fatigue crack initiation and to establish the effects of key parameters on the fatigue life of these steels. Statistical models are presented for estimating fatigue life as a function of material, loading, and environmental conditions. An environmental fatigue correction factor for incorporating the effects of LWR environments into ASME Code fatigue evaluations is described. This paper also presents a critical review of the ASME Code fatigue design margins of 2 on stress (or strain) and 20 on life and assesses the possible conservatism in the current choice of design margins.

  10. Effect of material heat treatment on fatigue crack initiation in austenitic stainless steels in LWR environments.

    SciTech Connect

    Chopra, O. K.; Alexandreanu, B.; Shack, W. J.; Energy Technology

    2005-07-31

    The ASME Boiler and Pressure Vessel Code provides rules for the design of Class 1 components of nuclear power plants. Figures I-9.1 through I-9.6 of Appendix I to Section III of the Code specify design curves for applicable structural materials. However, the effects of light water reactor (LWR) coolant environments are not explicitly addressed by the Code design curves. The existing fatigue strain-vs.-life ({var_epsilon}-N) data illustrate potentially significant effects of LWR coolant environments on the fatigue resistance of pressure vessel and piping steels. Under certain environmental and loading conditions, fatigue lives of austenitic stainless steels (SSs) can be a factor of 20 lower in water than in air. This report presents experimental data on the effect of heat treatment on fatigue crack initiation in austenitic Type 304 SS in LWR coolant environments. A detailed metallographic examination of fatigue test specimens was performed to characterize the crack morphology and fracture morphology. The key material, loading, and environmental parameters and their effect on the fatigue life of these steels are also described. Statistical models are presented for estimating the fatigue {var_epsilon}-N curves for austenitic SSs as a function of material, loading, and environmental parameters. Two methods for incorporating the effects of LWR coolant environments into the ASME Code fatigue evaluations are presented.

  11. Controls on ground water chemistry in the central Couloir Sud Rifain, Morocco.

    PubMed

    Benaabidate, Lahcen; Fryar, Alan E

    2010-01-01

    Irrigation, urbanization, and drought pose challenges for the sustainable use of ground water in the central Couloir sud rifain, a major agricultural region in north-central Morocco, which includes the cities of Fès and Meknès. The central Couloir is underlain by unconfined and confined carbonate aquifers that have suffered declines in hydraulic head and reductions in spring flow in recent decades. Previous studies have surveyed ground water flow and water quality in wells and springs but have not comprehensively addressed the chemistry of the regional aquifer system. Using graphical techniques and saturation index calculations, we infer that major ion chemistry is controlled (1) in the surficial aquifer by cation exchange, calcite dissolution, mixing with deep ground water, and possibly calcite precipitation and (2) in the confined aquifer and warm springs by calcite dissolution, dolomite dissolution, mixing with water that has dissolved gypsum and halite, and calcite precipitation. Analyses of (2)H and (18)O indicate that shallow ground water is affected by evaporation during recharge (either of infiltrating precipitation or return flow), whereas deep ground water is sustained by meteoric recharge with little evaporation. Mechanisms of recharge and hydrochemical evolution are broadly consistent with those delineated for similar regional aquifer systems elsewhere in Morocco and in southern Spain. PMID:19210561

  12. The unique chemistry of Eastern Mediterranean water masses selects for distinct microbial communities by depth.

    PubMed

    Techtmann, Stephen M; Fortney, Julian L; Ayers, Kati A; Joyner, Dominique C; Linley, Thomas D; Pfiffner, Susan M; Hazen, Terry C

    2015-01-01

    The waters of the Eastern Mediterranean are characterized by unique physical and chemical properties within separate water masses occupying different depths. Distinct water masses are present throughout the oceans, which drive thermohaline circulation. These water masses may contain specific microbial assemblages. The goal of this study was to examine the effect of physical and geological phenomena on the microbial community of the Eastern Mediterranean water column. Chemical measurements were combined with phospholipid fatty acid (PLFA) analysis and high-throughput 16S rRNA sequencing to characterize the microbial community in the water column at five sites. We demonstrate that the chemistry and microbial community of the water column were stratified into three distinct water masses. The salinity and nutrient concentrations vary between these water masses. Nutrient concentrations increased with depth, and salinity was highest in the intermediate water mass. Our PLFA analysis indicated different lipid classes were abundant in each water mass, suggesting that distinct groups of microbes inhabit these water masses. 16S rRNA gene sequencing confirmed the presence of distinct microbial communities in each water mass. Taxa involved in autotrophic nitrogen cycling were enriched in the intermediate water mass suggesting that microbes in this water mass may be important to the nitrogen cycle of the Eastern Mediterranean. The Eastern Mediterranean also contains numerous active hydrocarbon seeps. We sampled above the North Alex Mud Volcano, in order to test the effect of these geological features on the microbial community in the adjacent water column. The community in the waters overlaying the mud volcano was distinct from other communities collected at similar depths and was enriched in known hydrocarbon degrading taxa. Our results demonstrate that physical phenomena such stratification as well as geological phenomena such as mud volcanoes strongly affect microbial

  13. The Unique Chemistry of Eastern Mediterranean Water Masses Selects for Distinct Microbial Communities by Depth

    PubMed Central

    Techtmann, Stephen M.; Fortney, Julian L.; Ayers, Kati A.; Joyner, Dominique C.; Linley, Thomas D.; Pfiffner, Susan M.; Hazen, Terry C.

    2015-01-01

    The waters of the Eastern Mediterranean are characterized by unique physical and chemical properties within separate water masses occupying different depths. Distinct water masses are present throughout the oceans, which drive thermohaline circulation. These water masses may contain specific microbial assemblages. The goal of this study was to examine the effect of physical and geological phenomena on the microbial community of the Eastern Mediterranean water column. Chemical measurements were combined with phospholipid fatty acid (PLFA) analysis and high-throughput 16S rRNA sequencing to characterize the microbial community in the water column at five sites. We demonstrate that the chemistry and microbial community of the water column were stratified into three distinct water masses. The salinity and nutrient concentrations vary between these water masses. Nutrient concentrations increased with depth, and salinity was highest in the intermediate water mass. Our PLFA analysis indicated different lipid classes were abundant in each water mass, suggesting that distinct groups of microbes inhabit these water masses. 16S rRNA gene sequencing confirmed the presence of distinct microbial communities in each water mass. Taxa involved in autotrophic nitrogen cycling were enriched in the intermediate water mass suggesting that microbes in this water mass may be important to the nitrogen cycle of the Eastern Mediterranean. The Eastern Mediterranean also contains numerous active hydrocarbon seeps. We sampled above the North Alex Mud Volcano, in order to test the effect of these geological features on the microbial community in the adjacent water column. The community in the waters overlaying the mud volcano was distinct from other communities collected at similar depths and was enriched in known hydrocarbon degrading taxa. Our results demonstrate that physical phenomena such stratification as well as geological phenomena such as mud volcanoes strongly affect microbial

  14. Precipitation chemistry - Atmospheric loadings to the surface waters of the Indian River lagoon basin by rainfall

    NASA Technical Reports Server (NTRS)

    Dreschel, Thomas W.; Madsen, Brooks C.; Maull, Lee A.; Hinkle, C. R.; Knott, William M., III

    1990-01-01

    Rain volume and chemistry monitoring as part of the Kennedy Space Center Long Term Environmental Monitoring Program included the years 1984-1987 as part of the National Atmospheric Deposition Program. Atmospheric deposition in rainfall consisted primarily of sea salt and hydrogen ion, sulfate, nitrate, and ammonium ions. The deposition of nitrogen (a principal plant nutrient) was on the order of 200-300 metric tons per year to the surface waters.

  15. Effects of iron on arsenic speciation and redox chemistry in acid mine water

    USGS Publications Warehouse

    Bednar, A.J.; Garbarino, J.R.; Ranville, J.F.; Wildeman, T.R.

    2005-01-01

    Concern about arsenic is increasing throughout the world, including areas of the United States. Elevated levels of arsenic above current drinking-water regulations in ground and surface water can be the result of purely natural phenomena, but often are due to anthropogenic activities, such as mining and agriculture. The current study correlates arsenic speciation in acid mine drainage and mining-influenced water with the important water-chemistry properties Eh, pH, and iron(III) concentration. The results show that arsenic speciation is generally in equilibrium with iron chemistry in low pH AMD, which is often not the case in other natural-water matrices. High pH mine waters and groundwater do not always hold to the redox predictions as well as low pH AMD samples. The oxidation and precipitation of oxyhydroxides deplete iron from some systems, and also affect arsenite and arsenate concentrations through sorption processes. ?? 2004 Elsevier B.V. All rights reserved.

  16. Correction of ground-water chemistry and carbon isotopic composition for effects of CO2 outgassing

    USGS Publications Warehouse

    Pearson, F.J., Jr.; Fisher, D.W.; Plummer, L.N.

    1978-01-01

    Direct Pco2 measurements on water samples from several CO2-charged warm springs are significantly higher than Pco2 values calculated from field pH and alkalinity (and other constituents). In addition, calcite saturation indices calculated from field pH and solution composition indicated supersaturation in samples which, on the basis of hydrogeologic concepts, should be near saturation or undersaturated. We attribute these discrepancies to uncertainties in field pH, resulting from CO2 outgassing during pH measurement. Because samples for direct Pco2 measurement can be taken with minimal disturbance to the water chemistry, we have used the measured Pco2 to back calculate an estimate of the field pH and the carbon isotopic composition of the water before outgassing. By reconstructing water chemistry in this way, we find generally consistent grouping of ??13C, pH, and degree of calcite saturation in samples taken from the same source at different times, an observation which we expect based on our understanding of the hydrogeology and geochemistry of the ground-water systems. This suggests that for very careful geochemical work, particularly on ground-waters much above ambient temperature, Pco2 measurements may provide more information on the system and a better estimate of its state of saturation with respect to carbonate minerals than can field measurements of pH. ?? 1978.

  17. Organic peroxide and OH formation in aerosol and cloud water: laboratory evidence for this aqueous chemistry

    NASA Astrophysics Data System (ADS)

    Lim, Y. B.; Turpin, B. J.

    2015-06-01

    Aqueous chemistry in atmospheric waters (e.g., cloud droplets or wet aerosols) is well accepted as an atmospheric pathway to produce secondary organic aerosol (SOAaq). Water-soluble organic compounds with small carbon numbers (C2-C3) are precursors for SOAaq and products include organic acids, organic sulfates, and high molecular weight compounds/oligomers. Fenton reactions and the uptake of gas-phase OH radicals are considered to be the major oxidant sources for aqueous organic chemistry. However, the sources and availability of oxidants in atmospheric waters are not well understood. The degree to which OH is produced in the aqueous phase affects the balance of radical and non-radical aqueous chemistry, the properties of the resulting aerosol, and likely its atmospheric behavior. This paper demonstrates organic peroxide formation during aqueous photooxidation of methylglyoxal using ultra high resolution Fourier Transform Ion Cyclotron Resonance electrospray ionization mass spectrometry (FTICR-MS). Organic peroxides are known to form through gas-phase oxidation of volatile organic compounds. They contribute secondary organic aerosol (SOA) formation directly by forming peroxyhemiacetals, and epoxides, and indirectly by enhancing gas-phase oxidation through OH recycling. We provide simulation results of organic peroxide/peroxyhemiacetal formation in clouds and wet aerosols and discuss organic peroxides as a source of condensed-phase OH radicals and as a contributor to aqueous SOA.

  18. The influence of supraglacial debris on proglacial runoff fluctuations and water chemistry

    NASA Astrophysics Data System (ADS)

    Fyffe, Catriona; Brock, Ben; Kirkbride, Martin; Black, Andrew; Smiraglia, Claudio; Diolaiuti, Guglielmina

    2016-04-01

    This paper seeks to explore how the debris' influence on glacial ablation, topography and drainage structure impacts on the water chemistry and runoff signal of the proglacial stream. This was achieved through analysis of the supraglacial and proglacial water chemistry and the proglacial hydrograph of Miage Glacier, Western Italian Alps. Although the supraglacial water chemistry was influenced by the debris, there was also evidence that the less efficient hydrological system beneath the debris-covered lower tongue also increased the ion concentration of the proglacial stream. Compared to published data for clean glaciers, fewer diurnally classified daily hydrographs were found in the proglacial discharge record, with the amplitude of the diurnal signal peaking later and being relatively low in amplitude. These hydrograph characteristics were thought due to the debris' attenuation of the melt signal, and the smaller input streams and less efficient subglacial drainage system beneath the debris-covered lower tongue. Warmer than average weather conditions were required for strongly diurnal hydrographs to be shown, with a 'saw-toothed' hydrograph shown under average conditions. The diurnal relationship between conductivity and discharge often demonstrated anti-clockwise hysteresis, indicating that the more rapidly routed dilute melt component from the mid-glacier peaked before the peak in discharge. Components from higher up glacier and the lower debris-covered tongue likely had longer transit times and reached the proglacial stream later.

  19. Effects of LWR coolant environments on fatigue lives of austenitic stainless steels

    SciTech Connect

    Chopra, O.K.; Gavenda, D.J.

    1997-07-01

    The ASME Boiler and Pressure Vessel Code fatigue design curves for structural materials do not explicitly address the effects of reactor coolant environments on fatigue life. Recent test data indicate a significant decrease in fatigue life of pressure vessel and piping materials in light water reactor (LWR) environments. Fatigue tests have been conducted on Types 304 and 316NG stainless steel in air and LWR environments to evaluate the effects of various material and loading variables, e.g., steel type, strain rate, dissolved oxygen (DO) in water, and strain range, on fatigue lives of these steels. The results confirm the significant decrease in fatigue life in water. The environmentally assisted decrease in fatigue life depends both on strain rate and DO content in water. A decrease in strain rate from 0.4 to 0.004%/s decreases fatigue life by a factor of {approx} 8. However, unlike carbon and low-alloy steels, environmental effects are more pronounced in low-DO than in high-DO water. At {approx} 0.004%/s strain rate, reduction in fatigue life in water containing <10 ppb D is greater by a factor of {approx} 2 than in water containing {ge} 200 ppb DO. Experimental results have been compared with estimates of fatigue life based on the statistical model. The formation and growth of fatigue cracks in austenitic stainless steels in air and LWR environments are discussed.

  20. Introduction of Mass Spectrometry in an First-Semester General Chemistry Laboratory Course: Quantification of Mtbe or Dmso in Water

    ERIC Educational Resources Information Center

    Solow, Mike

    2004-01-01

    Quantification of a contaminant in water provides the first-year general chemistry students with a tangible application of mass spectrometry. The relevance of chemistry to assessing and solving environmental problems is highlighted for students when they perform mass spectroscopy experiments.

  1. Wildfires and water chemistry: effect of metals associated with wood ash.

    PubMed

    Cerrato, José M; Blake, Johanna M; Hirani, Chris; Clark, Alexander L; Ali, Abdul-Mehdi S; Artyushkova, Kateryna; Peterson, Eric; Bixby, Rebecca J

    2016-08-10

    The reactivity of metals associated with ash from wood collected from the Valles Caldera National Preserve, Jemez Mountains, New Mexico, was assessed through a series of laboratory experiments. Microscopy, spectroscopy, diffraction, and aqueous chemistry measurements were integrated to determine the chemical composition of wood ash and its effect on water chemistry. Climate change has caused dramatic impacts and stresses that have resulted in large-scale increases in wildfire activity in semi-arid areas of the world. Metals and other constituents associated with wildfire ash can be transported by storm event runoff and negatively affect the water quality in streams and rivers. Differences among ash from six tree species based on total concentrations of metals such as Ca, Al, Mg, Fe, and Mn were identified using non-metric multidimensional analysis. Metal-bearing carbonate and oxide phases were quantified by X-ray diffraction analyses and X-ray spectroscopy analyses. These metal-bearing carbonate phases were readily dissolved in the first 30 minutes of reaction with 18 MΩ water and 10 mM HCO3(-) in laboratory batch experiments which resulted in the release of metals and carbonates in the ash, causing water alkalinity to increase. However, metal concentrations decreased over the course of the experiment, suggesting that metals re-adsorb to ash. Our results suggest that the dissolution of metal-bearing carbonate and oxide phases in ash and metal re-adsorption to ash are relevant processes affecting water chemistry after wildfire events. These results have important implications to better understand the impact of wildfire events on water quality. PMID:27457586

  2. Understanding the Role of Water on Electron-Initiated Processes and Radical Chemistry

    SciTech Connect

    Garrett, Bruce C; Colson, Steven D; Dixon, David A.; Laufer, Allan H; Ray, Douglas

    2003-06-10

    On September 26–28, 2002, a workshop entitled “Understanding the Role of Water on Electron-Initiated Processes and Radical Chemistry” was held to assess new research opportunities in electron-driven processes and radical chemistry in aqueous systems. Of particular interest was the unique and complex role that the structure of water plays in influencing these processes. Novel experimental and theoretical approaches to solving long-standing problems in the field were explored. A broad selection of participants from universities and the national laboratories contributed to the workshop, which included scientific and technical presentations and parallel sessions for discussions and report writing.

  3. Technical report on LWR design decision methodology. Phase I

    SciTech Connect

    1980-03-01

    Energy Incorporated (EI) was selected by Sandia Laboratories to develop and test on LWR design decision methodology. Contract Number 42-4229 provided funding for Phase I of this work. This technical report on LWR design decision methodology documents the activities performed under that contract. Phase I was a short-term effort to thoroughly review the curret LWR design decision process to assure complete understanding of current practices and to establish a well defined interface for development of initial quantitative design guidelines.

  4. HIGH TEMPERATURE THERMAL AND STRUCTURAL MATERIAL PROPERTIES FOR METALS USED IN LWR VESSELS

    SciTech Connect

    J.L. Rempe; D.L. Knudson; J. E. Daw; J. C. Crepeau

    2008-06-01

    Because of the impact that melt relocation and vessel failure may have on subsequent progression and associated consequences of a Light Water Reactor (LWR) accident, it is important to accurately predict heating and relocation of materials within the reactor vessel, heat transfer to and from the reactor vessel, and the potential for failure of the vessel and structures within it. Accurate predictions of such phenomena require high temperature thermal and structural properties. However, a review of vessel and structural steel material properties used in severe accident analysis codes reveals that the required high temperature material properties are extrapolated with little, if any, data above 1000 K. To reduce uncertainties in predictions relying upon extrapolated high temperature data, Idaho National Laboratory (INL) obtained high data for two metals used in LWR vessels: SA 533 Grade B, Class 1 (SA533B1) low alloy steel, which is used to fabricate most US LWR reactor vessels; and Type 304 Stainless Steel SS304, which is used in LWR vessel piping, penetration tubes, and internal structures. This paper summarizes the new data, and compares it to existing data.

  5. Evolution of water chemistry during Marcellus Shale gas development: A case study in West Virginia.

    PubMed

    Ziemkiewicz, Paul F; Thomas He, Y

    2015-09-01

    Hydraulic fracturing (HF) has been used with horizontal drilling to extract gas and natural gas liquids from source rock such as the Marcellus Shale in the Appalachian Basin. Horizontal drilling and HF generates large volumes of waste water known as flowback. While inorganic ion chemistry has been well characterized, and the general increase in concentration through the flowback is widely recognized, the literature contains little information relative to organic compounds and radionuclides. This study examined the chemical evolution of liquid process and waste streams (including makeup water, HF fluids, and flowback) in four Marcellus Shale gas well sites in north central West Virginia. Concentrations of organic and inorganic constituents and radioactive isotopes were measured to determine changes in waste water chemistry during shale gas development. We found that additives used in fracturing fluid may contribute to some of the constituents (e.g., Fe) found in flowback, but they appear to play a minor role. Time sequence samples collected during flowback indicated increasing concentrations of organic, inorganic and radioactive constituents. Nearly all constituents were found in much higher concentrations in flowback water than in injected HF fluids suggesting that the bulk of constituents originate in the Marcellus Shale formation rather than in the formulation of the injected HF fluids. Liquid wastes such as flowback and produced water, are largely recycled for subsequent fracturing operations. These practices limit environmental exposure to flowback. PMID:25957035

  6. Mineralogical and Anthropogenic Controls of Stream Water Chemistry in Salted Watersheds

    NASA Astrophysics Data System (ADS)

    Sun, H.; Alexander, J.; Gove, B.; Chakowski, N.; Husch, J.

    2013-12-01

    Analyses of major cation and anion concentrations in stream water and soil solutions from two salted (regular applications of winter road deicing salt) watersheds located in the northeastern United States indicate that both mineralogical and anthropogenic factors are important in controlling water chemistry. The relatively stable concentrations of calcium and magnesium, as well as their possible weathering paths identified by mass-balance models, indicate that the weathering of feldspars and the dissolution of carbonates are the primary sources for these two cations in the small, salted Centennial Lake Watershed (CLW, 1.95 km 2). However, the relatively stable and lower concentrations of sodium and chloride in soil solutions, and their fluctuating and higher concentrations in stream water from the CLW, indicate that road deicing salt is the primary source for these ions in stream water. Furthermore, positive correlations between calcium and sulfur concentrations and magnesium and sulfur concentrations in soil solutions, as well as positive correlations between sulfur and iron concentrations in soil compositions, indicate that both the dissolution of gypsum and the oxidation of pyrite into hematite are the primary sources of sulfate in the CLW. Analyses of water chemistry from the related and much larger Delaware River Watershed (DRW, 17560 km 2) show that sodium and chloride concentrations have increased steadily due to the regular application of winter deicing salt over the 68 years for which data are available. The more rapid increase of stream water chloride concentrations, relative to the increase in sodium, also results in the steady decline of Na+/Cl-molar ratios in the DRW over that time. In addition, the reduction of sulfate and increase of bicarbonate concentration since 1980 in DRW stream water may be attributed to the decline of sulfate levels in atmospheric deposition resulting from enhanced national and state environmental regulations and a shift in

  7. Chemistry of Water Collected From an Unventillated Drift, Yucca Mountain, Nevada

    SciTech Connect

    B.D. Marshall; T.A. Oliver; Z.E. Peterman

    2006-06-20

    The chemical composition of water that may be present in the emplacement drifts is a key issue for the isolation of high-level radioactive waste in a proposed mined geologic repository at Yucca Mountain, Nevada. Chemical constituents in water that may contact waste containers may affect rates of corrosion of the container materials. Long-term simulations of the in-drift chemical environment rely on ambient water chemistry, heat perturbations, and the interaction of ambient water with the engineered barriers (e.g. waste containers) and other introduced materials (e.g. rock bolts). In an attempt to induce seepage in the Enhanced Characterization of the Repository Block Cross Drift, bulkheads were constructed to isolate part of the 2.7-km-long drift from active ventilation. The bulkheads were closed and active ventilation ceased for periods up.to 454 days. After opening the bulkheads, water was observed in small puddles on plastic sheets and on rubber conveyor belt surfaces; droplets of water were observed on many surfaces of various construction-related introduced materials. Mold or fungal colonies also were present. The puddles of water were sampled seven times from January 2003 to June 2005; most samples appeared yellow to brown. The water samples were analyzed for major and trace constituents by using ion chromatography and inductively-coupled plasma mass spectrometry. Total dissolved solids (TDS) in the puddle-water samples ranged from 195 to 22,000 milligrams per liter (mg/L) and pH ranged from 4.2 to 8.9; these values are different from ambient pore-water samples extracted from adjacent rock (TDS < 1,400 mg/L and pH from 6.7 to 8.2). The chemical composition of the puddle-water samples is dominated by sodium and chloride, also different from the pore-water samples, which are dominated by sodium, calcium, and bicarbonate. Zinc concentrations ranged from 0.5 to 3,100 mg/L, substantially greater than the less than 0.1 mg/L values measured in pore water. Some of

  8. Complexes and clusters of water relevant to atmospheric chemistry: H2O complexes with oxidants.

    PubMed

    Sennikov, Petr G; Ignatov, Stanislav K; Schrems, Otto

    2005-03-01

    Experimental observations and data from quantum chemical calculations on complexes between water molecules and small, oxygen-containing inorganic species that play an important role as oxidants in the atmosphere (O(1D), O(3P), O2(X3sigmag), O2(b1sigmag+), O3, HO, HOO, HOOO, and H2O2) are reviewed, with emphasis on their structure, hydrogen bonding, interaction energies, thermodynamic parameters, and infrared spectra. In recent years, weakly bound complexes containing water have increasingly attracted scientific attention. Water in all its phases is a major player in the absorption of solar and terrestrial radiation. Thus, complexes between water and other atmospheric species may have a perceivable influence on the radiative balance and contribute to the greenhouse effect, even though their concentrations are low. In addition, they can play an important role in the chemistry of the Earth's atmosphere, particularly in the oxidation of trace gases. Apart from gas-phase complexes, the interactions of oxidants with ice surfaces have also received considerable advertency lately due to their importance in the chemistry of snow, ice clouds, and ice surfaces (e.g., ice shields in polar regions). In paleoclimate--respectively paleoenvironmental--studies, it is essential to understand the transfer processes from the atmosphere to the ice surface. Consequently, special attention is being paid here to the intercomparison of the properties of binary complexes and the complexes and clusters of more complicated compositions, including oxidants adsorbed on ice surfaces, where ice is considered a kind of large water cluster. Various facts concerning the chemistry of the Earth's atmosphere (concentration profiles and possible influence on radical reactions in the atmosphere) are discussed. PMID:15799459

  9. Relationships between precipitation and surface water chemistry in three Carolina bays

    SciTech Connect

    Monegue, R.L.; Jagoe, C.H.

    1995-12-31

    Carolina Bays are shallow freshwater wetlands, the only naturally occurring lentic systems on the southeastern coastal plain. Bays are breeding sites for many amphibian species, but data on precipitation/surface water relationships and long-term chemical trends are lacking. Such data are essential to interpret major fluctuations in amphibian populations. Surface water and bulk precipitation were sampled bi-weekly for over two years at three bays along a 25 km transect on the Savannah River Site in South Carolina. Precipitation chemistry was similar at all sites; average pH was 4.56, and the major ions were H{sup +} (30.8 % of total), and SO{sub 4} (50.3% of total). H{sup +} was positively correlated with SO{sub 4}, suggesting the importance of anthropogenic acids to precipitation chemistry. All three bays, Rainbow Bay (RB), Thunder Bay (TB), and Ellenton Bay (EB), contained soft (specific conductivity 5--90 {micro}S/cm), acidic water (pH 4.0--5.9) with DOM from 4--40 mg/L. The major cation for RB, TB, and EB, respectively, was: Mg (30.8 % of total); Na (27% of total); and Ca (34.2% of total). DOM was the major anion for all bays, and SO{sub 4} represented 13 to 28 % of total anions. H{sup +} was not correlated to DOM or SO, in RB; H{sup +} was positively correlated to DOM and SO{sub 4} in TB, and negatively correlated to DOM and SO{sub 4} in EB. Different biogeochemical processes probably control pH and other chemical variables in each bay. While surface water H{sup +} was not directly correlated with precipitation H{sup +}, NO{sub 3}, or SO{sub 4}, precipitation and shallow groundwater are dominant water sources for these bays. Atmospheric inputs of anthropogenic acids and other chemicals are important factors influencing bay chemistry.

  10. Analysis of Water-Quality Trends for Selected Streams in the Water Chemistry Monitoring Program, Michigan, 1998-2005

    USGS Publications Warehouse

    Hoard, C.J.; Fuller, Lori M.; Fogarty, Lisa R.

    2009-01-01

    In 1998, the Michigan Department of Environmental Quality and the U.S. Geological Survey began a long-term monitoring program to evaluate the water quality of most watersheds in Michigan. Major goals of this Water-Chemistry Monitoring Program were to identify streams exceeding or not meeting State or Federal water-quality standards and to assess if constituent concentrations reflecting water quality in these streams were increasing or decreasing over time. As part of this program, water-quality data collected from 1998 to 2005 were analyzed to identify potential trends. Sixteen water-quality constituents were analyzed at 31 sites across Michigan, 28 of which had sufficient data to analyze for trends. Trend analysis on the various water-quality data was done using the uncensored Seasonal Kendall test within the computer program ESTREND. The most prevalent trend detected throughout the state was for chloride. Chloride trends were detected at 8 of the 28 sites; trends at 7 sites were increasing and the trend at 1 site was decreasing. Although no trends were detected for various nitrogen species or phosphorus, these constituents were detected at levels greater than the U.S. Environmental Protection Agency recommendations for nutrients in water. The results of the trend analysis will help to establish a baseline to evaluate future changes in water quality in Michigan streams.

  11. Seasonal variation of water level, water and soil temperature, chemistry, and stable isotopes in hyporheic zone of Korea

    NASA Astrophysics Data System (ADS)

    Jeon, W. H.; Lee, J. Y.

    2015-12-01

    The purpose of study was to evaluate interaction between groundwater and stream water in hyporheic zone using water level, water temperature, soil temperature, chemistry, and stable isotopes. We installed seven piezometers (IYHW1 to 7) in the streambed that across stream in every 10 m and in depth of 0.85 to 1.54 m, a device that measure stage level nearby IYHW1, and devices that measure soil temperature in every 10 cm down to 50 cm nearby each piezometer was installed. We monitored water level and water temperature every hour from automatic transducers at the piezometers and the stage level, and soil temperatures were monitored every two hours. We took samples from the hyporheic water, stream water, and nearby groundwater to analysis chemical and isotopic compositions. The water level difference between stream water and hyporheic waters indicated that groundwater was downwelling in wet season and upwelling in dry season. The groundwater temperature remained steady in different seasons, but the stream water represented a frequent fluctuation with large amplitude. The hyporheic waters and soil temperature represented intermediate variation characteristics. The chemical compositions were not able to indicate in interaction of groundwater and stream water because no distinctive difference in seasonal variation in waters. The quantity of isotopic compositions of oxygen and hydrogen determined from using mixing ratio indicated that downwelling in wet season and upwelling in dry season. This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2011-0007232).

  12. LWR spent fuel reduction by the removal of U and the compact storage of Pu with FP for long-term nuclear sustainability

    SciTech Connect

    Fukasawa, T.; Hoshino, K.; Takano, M.; Sato, S.; Shimazu, Y.

    2013-07-01

    Fast breeder reactors (FBR) nuclear fuel cycle is needed for long-term nuclear sustainability while preventing global warming and maximum utilizing the limited uranium (U) resources. The 'Framework for Nuclear Energy Policy' by the Japanese government on October 2005 stated that commercial FBR deployment will start around 2050 under its suitable conditions by the successive replacement of light water reactors (LWR) to FBR. Even after Fukushima Daiichi Nuclear Power Plant accident which made Japanese tendency slow down the nuclear power generation activities, Japan should have various options for energy resources including nuclear, and also consider the delay of FBR deployment and increase of LWR spent fuel (LWR-SF) storage amounts. As plutonium (Pu) for FBR deployment will be supplied from LWR-SF reprocessing and Japan will not possess surplus Pu, the authors have developed the flexible fuel cycle initiative (FFCI) for the transition from LWR to FBR. The FFCI system is based on the possibility to stored recycled materials (U, Pu)temporarily for a suitable period according to the FBR deployment rate to control the Pu demand/supply balance. This FFCI system is also effective after the Fukushima accident for the reduction of LWR-SF and future LWR-to-FBR transition. (authors)

  13. INLAND DISSOLVED SALT CHEMISTRY: STATISTICAL EVALUATION OF BIVARIATE AND TERNARY DIAGRAM MODELS FOR SURFACE AND SUBSURFACE WATERS

    EPA Science Inventory

    We compared the use of ternary and bivariate diagrams to distinguish the effects of atmospheric precipitation, rock weathering, and evaporation on inland surface and subsurface water chemistry. The three processes could not be statistically differentiated using bivariate models e...

  14. National Surface Water Survey: Western Lake Survey (Phase 1 - synoptic chemistry) quality assurance plan

    SciTech Connect

    Silverstein, M.E.; Drouse, S.K.; Engels, J.L.; Faber, M.L.; Mitchell-Hall, T.E.

    1987-06-01

    The purpose of the National Surface Water Survey of the National Acid Precipitation Assessment Program is to evaluate the present water chemistry of lakes and streams, to determine the status of certain biotic resources, and to select regionally representative surface waters for a long-term monitoring program to study changes in aquatic resources. The Western Lake Survey is part of the National Surface Water Survey. The U.S. Environmental Protection Agency requires that data-collection activities be based on a program that ensures that the resulting data are of known quality and are suitable for their intended purpose. This quality assurance plan describes in detail the quality-assurance requirements and procedures that are unique to the Western Lake Survey - Phase I.

  15. Characteristics of spent fuel, high-level waste, and other radioactive wastes which may require long-term isolation: Appendix 2A, Physical descriptions of LWR (Light-Water Reactor) fuel assemblies

    SciTech Connect

    Not Available

    1987-12-01

    This appendix includes a four-page Physical Description report for each assembly type identified from the current data. Where available, a drawing of an assembly follows the appropriate Physical Description report. If no drawing is available for an assembly, a cross-reference to a similar assembly is provided if possible. For Advanced Nuclear Fuels, Babcock and Wilcox, Combustion Engineering, and Westinghouse assemblies, information was obtained via subcontracts with these fuel vendors. Data for some assembly types are not available. For such assemblies, the information shown in this report was obtained from the open literature and by inference from reload fuels made by other vendors. Efforts to obtain additional information are continuing. Individual Physical Description reports can be generated interactively through the menu-driven LWR Assemblies Data Base system. These reports can be viewed on the screen or directed to a printer. Special reports and compilations of specific data items can be produced on request.

  16. Geohydrology and water chemistry in the Rialto-Colton Basin, San Bernardino County, California

    USGS Publications Warehouse

    Woolfenden, Linda R.; Kadhim, Dina

    1997-01-01

    The 40-square-mile Rialto-Colton ground- water basin is in western San Bernardino County, California, about 60 miles east of Los Angeles.This basin was chosen for storage of imported water because of the good quality of native ground water, the known capacity for additional ground-water storage in the basin, and the availability of imported water. Because the movement and mixing of imported water needed to be determined, the San Bernardino Valley Municipal Water District entered into a cooperative program with the U.S.Geological Survey in 1991 to study the geohydrology and water chemistry in the Rialto- Colton basin. Ground-water flow and chemistry were investigated using existing data, borehole- geophysical and lithologic logs from newly drilled test holes, measurement of water levels, and chemical analyses of water samples. The Rialto-Colton basin is bounded on the northwest and southeast by the San Gabriel Mountains and the Badlands, respectively. The San Jacinto Fault and Barrier E form the northeastern boundary, and the Rialto-Colton Fault forms the southwestern boundary. Except in the southeastern part of the basin, the San Jacinto and Rialto-Colton Faults act as groundwater barriers that impede ground- water flow into and out of the basin.Barrier E generally does not impede ground- water flow into the basin. The ground-water system consists primarily of gravel, sand, silt, and clay. The maximum thickness is greater than 1,000 feet. The ground- water system is divided into four water-bearing units: river-channel deposits, and upper, middle, and lower water-bearing units. Relatively impermeable consolidated deposits underlie the lower water- bearing unit and form the lower boundary of the ground- water system. Ground water moves from east to west in the river-channel deposits and upper water-bearing unit in the southeastern part of the basin, and from northwest to southeast in the middle and lower water-bearing units. Two major internal faults, Barrier J and

  17. Evaluation of FSV-1 cask for the transport of LWR irradiated fuel assemblies

    SciTech Connect

    Not Available

    1980-05-01

    The Model FSV-1 spent fuel shipping cask was designed by General Atomic Company (GA) to service the Fort St. Vrain (FSV) nuclear generating station, a High Temperature Gas Reactor (HTGR) owned and operated by Public Service Company of Colorado (PSC). This report presents an evaluation of the suitability of the FSV-1 cask for the transport of irradiated Light Water Reactor (LWR) fuel assemblies from both Pressurized Water Reactors (PWR) and Boiling Water Reactors (BWR). The FSV-1 cask evaluation parameters covered a wide spectrum of LWR fuel assemblies, based on burnup in Megawatt Days/Metric Ton of Heavy Metal (MWD/MTHM) and years of decay since irradiation. The criteria for suitability included allowable radiation dose rates, cask surface and interior temperatures and the Gross Vehicle Weight (GVW) of the complete shipping system.

  18. Chemistry and age of ground water in the southwestern Hueco Bolson, New Mexico and Texas

    USGS Publications Warehouse

    Anderholm, Scott K.; Heywood, Charles E.

    2003-01-01

    This report, prepared in cooperation with El Paso Water Utilities, presents the results of an investigation to determine the chemistry and age of ground water on the southwestern side of the Hueco Bolson. The radioactive isotope carbon-14 was used to estimate the length of time that water from wells has been isolated from the atmosphere, which is the modern carbon-14 reservoir. Nine wells on the southwestern side of the Hueco Bolson were sampled for analysis of common constituents, nutrients, total organic carbon, trace elements, stable isotopes, and radioactive isotopes. Dissolved-solids concentrations in water from the wells sampled ranged from 269 to 2,630 milligrams per liter. Sodium concentrations generally increased linearly with chloride concentrations, possibly indicating mixing of dilute recharge water with sodium chloride brine. Concentrations of nutrients and trace elements generally were small. The deuterium and oxygen-18 composition in all samples except those from wells adjacent to the Rio Grande indicates that infiltration of precipitation is the main source of water to these wells and that evaporation has not affected the isotopic composition of the water. The source of water from wells adjacent to the Rio Grande is probably not the same source as the water from wells adjacent to the Franklin Mountains. The calculated apparent carbon- 14 ages ranged from 12,100 to 25,500 years.

  19. Chemistry of the solid-water interface: Processes at the mineral-water and particle-water interface in natural systems

    SciTech Connect

    Stumm, W.

    1992-01-01

    The title book covers coordination chemistry of the hydrous oxide-water interface; surface charge and the electric double layer; adsorption; chemical weathering phenomena; homogeneous and heterogeneous nucleation and precipitation; particle-particle interaction; carbonate reactivity; redox processes mediated by surfaces; photochemistry; and trace element transport. It can be used as a source book for teaching and for professionals in geochemical and environmental disciplines.

  20. Lagrangian transport of water vapor and CFCs in a coupled Chemistry Climate Model

    NASA Astrophysics Data System (ADS)

    Hoppe, Charlotte; Müller, Rolf; Hoffmann, Lars; Konopka, Paul; Plöger, Felix; Grooß, Jens-Uwe

    2013-04-01

    We describe the implementation of a Lagrangian transport core in a chemistry climate model (CCM). Thereby we address the common problem of properly representing trace gas distributions in a classical Eulerian framework with a fixed model grid, particularly in regions with strong trace gas gradients. A prominent example is stratospheric water vapor, which is an important driver of surface climate change on decadal scales. In this case, the transport representation is particularly important in the tropical tropopause layer (TTL), where tropospheric air enters into the stratosphere. We have coupled the Chemical Lagrangian Model of the Stratosphere (CLaMS) with the ECHAM-MESSy Atmospheric Chemistry Model (EMAC). The latter includes the ECHAM5 climate model, and the MESSy interface, which allows for flexible coupling and switching between different submodels. The chemistry transport model CLaMS provides a fully Lagrangian transport representation to calculate constituent transport for an ensemble of air parcels that move along trajectories. To facilitate the calculation of long time-series a simplified chemistry scheme was implemented. Various studies show that the CLaMS model is particularly suited to properly represent dynamics and chemistry in the UT/LS region. The analysis of mean age of stratospheric air gives insight into the different transport characteristics of the Eulerian and the Lagrangian transport schemes. Mean age of air, calculated in both frameworks, is compared regarding the representation of important processes, i.e. descent in the polar vortex, upwelling in the tropical pipe, and isentropic in-mixing in subtropical regions. We also compared the zonal mean distributions and photochemical lifetimes of CFC-11 and CFC-12 with climatologies from different satellite experiments (ACE-FTS, HIRDLS, and MIPAS). CLaMS stratospheric water vapor distributions show remarkable differences compared to the stratospheric water vapor simulated by ECHAM, especially in

  1. Uncertainties in water chemistry in disks: An application to TW Hydrae

    NASA Astrophysics Data System (ADS)

    Kamp, I.; Thi, W.-F.; Meeus, G.; Woitke, P.; Pinte, C.; Meijerink, R.; Spaans, M.; Pascucci, I.; Aresu, G.; Dent, W. R. F.

    2013-11-01

    Context. This paper discusses the sensitivity of water lines to chemical processes and radiative transfer for the protoplanetary disk around TW Hya. The study focuses on the Herschel spectral range in the context of new line detections with the PACS instrument from the Gas in Protoplanetary Systems project (GASPS). Aims: The paper presents an overview of the chemistry in the main water reservoirs in the disk around TW Hya. It discusses the limitations in the interpretation of observed water line fluxes. Methods: We use a previously published thermo-chemical Protoplanetary Disk Model (ProDiMo) of the disk around TW Hya and study a range of chemical modeling uncertainties: metallicity, C/O ratio, and reaction pathways and rates leading to the formation of water. We provide results for the simplified assumption of Tgas = Tdust to quantify uncertainties arising for the complex heating/cooling processes of the gas and elaborate on limitations due to water line radiative transfer. Results: We report new line detections of p-H2O (322-211) at 89.99 μm and CO J = 18-17 at 144.78 μm for the disk around TW Hya. Disk modeling shows that the far-IR fine structure lines ([O i], [C ii]) and molecular submm lines are very robust to uncertainties in the chemistry, while the water line fluxes can change by factors of a few. The water lines are optically thick, sub-thermally excited and can couple to the background continuum radiation field. The low-excitation water lines are also sensitive to uncertainties in the collision rates, e.g. with neutral hydrogen. The gas temperature plays an important role for the [O i] fine structure line fluxes, the water line fluxes originating from the inner disk as well as the high excitation CO, CH+ and OH lines. Conclusions: Due to their sensitivity on chemical input data and radiative transfer, water lines have to be used cautiously for understanding details of the disk structure. Water lines covering a wide range of excitation energies provide

  2. Thermal Properties of Structural Materials Used in LWR Vessels

    SciTech Connect

    J. E. Daw; J. L. Rempe; D. L. Knudson

    2011-01-01

    High temperature material property data for structural materials used in existing Light Water Reactors (LWRs) are limited. Often, extrapolated values recommended in the literature differ significantly. To reduce uncertainties in predictions relying upon extrapolated data for LWR vessel and penetration materials, high temperature tests were completed on SA533 Grade B, Class 1 (SA533B1) low alloy steel, Stainless Steel 304 (SS304), and Inconel 600 using material property measurement systems available in the High Temperature Test Laboratory (HTTL) at the Idaho National Laboratory (INL). Properties measured include thermal expansion, specific heat capacity, and thermal diffusivity for temperatures up to 1200 °C. From these results, thermal conductivity and density were calculated. Results show that, in some cases, previously recommended values for these materials differ significantly from measured values at high temperatures.

  3. Short Term Variability in Water Column and Porewater Carbon Chemistry on a Tropical Reef

    NASA Astrophysics Data System (ADS)

    Drupp, P. S.; De Carlo, E. H.; Mackenzie, F. T.; Thompson, R.; Sabine, C. L.; Feely, R. A.

    2013-12-01

    A high-resolution carbon system study has been ongoing on the Kaneohe Bay barrier reef on the island of Oahu, Hawaii since 2008, in an effort to characterize short term variability of the carbon system in the water column and porewaters. In addition, during a 3 week time period from June 4th-24th, multiple sensors were deployed at the CRIMP-2 MAPCO2 buoy and discrete bottle samples were collected frequently, including once an hour for a period of 48 hours. In-situ sensors measured pCO2, pH, temperature and salinity at the CRIMP-2 location. Dissolved inorganic carbon to total alkalinity ratios indicate a reef system where primary production slightly exceeds calcification, consistent with previous studies on the reef. A second MAP-CO2 buoy located outside the bay (Kaneohe Buoy) also measured pCO2 and pH to serve as an end member point for water entering the reef system. Porewater has been collected at varying depths in order to determine the effect of overlying water conditions on the carbonic-acid system chemistry. Porewater alkalinity appears to vary with changes in overlying water column chemistry and physical forcings such as wind and current speeds, which influence flushing rates and ventilation, and calcium and magnesium data suggests dissolution of soluble magnesian calcites concurrently with precipitation of calcites.

  4. Assessing Changes in Water Chemistry Along the Mountain to Urban Gradient

    NASA Astrophysics Data System (ADS)

    Gabor, R. S.; Brooks, P. D.; Neilson, B. T.; Barnes, M. L.; Stout, T.; Millington, M. R.; Gelderloos, A.; Tennant, H.; Eiriksson, D.

    2015-12-01

    Throughout the western US, growing population centers rely on mountain watersheds that are already sensitive to hydrologic stressors. We examined rivers along Utah's Wasatch Front over a range of spatial and discharge scales, confusing on the mountain-to-urban transition to identify how urbanization impacts water resources. The rivers we studied all originate in canyons with impact level ranging from minimal human disturbance to roads and open grazing cattle. Each river enters an urban area after leaving the canyon, where there is significantly more anthropogenic impact on the system. As part of an interdisciplinary effort with the iUTAH project, sample sites were selected at intervals along each river and a variety of measurements were made, including basic water chemistry along with discharge, water isotopes, nutrients, and organic matter analysis. By combining physical and chemical parameters we were able to quantify groundwater influence in gaining reaches and how those differ between the mountain and urban environments. We also identified how the urban system impacted hydrologic and biogeochemical processes in the catchment. For example, in Red Butte Creek discharge tripled through gaining reached in the canyon with only small corresponding changes in conductivity or nitrate levels. However in the urban stretch a gaining reach that tripled the discharge corresponded with a doubling in the conductivity and order of magnitude increase in nitrate. The fact that we first see this change in chemistry during a gaining reach, and not in an area full of storm culverts, suggests that urban impact to stream chemistry predominately occurs through the groundwater. Further work will incorporate ecological and climatic data along with the hydrologic and chemical datasets to identify how controls on water resources change along the mountain to urban gradient. By combining this physical information with sociological data we can identify green infrastructure solutions to

  5. Monsoon Season Surface Water Chemistry Response Following Wildfire: 2003 Aspen Fire in Sabino Canyon, Arizona

    NASA Astrophysics Data System (ADS)

    Einloth, S. L.; Chief, K. D.; Ekwurzel, B.; Nijssen, B.; Ferré, P. A.

    2003-12-01

    The Aspen Fire in the Coronado National Forest north of Tucson burned in excess of 80,000 acres and destroyed more than 300 structures. Exposed, burned soils are highly vulnerable to intense monsoon rains, leading to increases in surface runoff, peak flows, and erosion rates. As part of an integrated investigation of the hydrologic impacts of this fire, we rapidly mobilized a field sampling campaign during the 2003 monsoon season that began immediately following the resolution of the fire. Stream water chemistry serves as an integrated signal of many watershed processes: precipitation, runoff, infiltration, soil hydrophobic layers, ash deposition in the stream, debris flows, and subsequent water/ash chemical equilibrium reactions. The portion of the watershed that has been burned by the Aspen fire covers a wide range of elevation and vegetation zones of the Santa Catalina Mountains. Many biogeochemical and hydrological processes within this area were altered by a sudden lack of vegetation and changes in soil properties following a fire: evapotranspiration, litter volume, organic decomposition, leaching, cation exchange, anion sorption, nutrient uptake, and soil hydrophobic layers. Surface water and precipitation samples were collected following an event-based sampling strategy, while soil samples were collected in each vegetation and burn severity regime. Precipitation samples were collected to characterize temperature and elevation effects on precipitation chemistry, in particular stable isotopes. The surface water chemistry changes measured throughout each hydrograph event can be linked to air permeameter results, a rapid measurement for soil hydraulic conductivity, for the different burn severity and vegetation zone regimes. Both nutrient and suspended sediment loads greatly increased following the fire. A debris flow mobilized large diameter boulders. Stream gauge flow event peaks were larger than expected given concurrent extensive precipitation gauge network

  6. Evaluation of Main Compositions of Water Chemistry Data By Graphical Methods, Edremit (Balikesir) Alluvial Aquifer System

    NASA Astrophysics Data System (ADS)

    Ertekin, Can; Sedat Çetiner, Ziya

    2015-04-01

    This case study aims to characterize and compare hydrogeochemistry based on major ion composition belonging to the year of 1970's, 2007 and 2008 for Edremit alluvial aquifer system which lies on the northwestern coast of Anatolia. Graphical representations including Piper, Schoeller, Stiff and Durov diagrams are applied to ease a systematic interpretation of a wide range of well chemistry data sets. In Piper diagram, water types of the aquifer system are mainly dominated with calcium, carbonate-bicarbonate and sulphate ions. Water types of the site are separated as sulphate or carbonate-bicarbonate ion dominated zones for 1970's data. Comparing data of 1970's, 2007 and 2008 the newest data set is clustered into magnesium dominate zone. This is related to relatively deep groundwater chemistry affect probably resulting from long term groundwater withdrawal for irrigation in the aquifer system. The Schoeller diagram portrays differences of the data set of 1970's, 2007 and 2008 more clearly comparing the Piper diagram. In this diagram, higher portions of magnesium and sulphate composition of the well data belonging to the year of 2007 and 2008 are possibly related to deep routes of groundwater flow paths of the site and/or geothermal water mixing. In Durov diagram, the data set was projected to a rectangular shape and it was not immediately clear to differentiate ionic composition of the water. This is not coincidence because the fact that pH values do not change significantly over the years and its contribution is not substantial comparing to major ion chemistry. Finally, application of hydrogeochemical modeling as a further step was touched upon herein to further depict undergone processes and end-members in the whole aquifer system on Edremit Plain. Keywords: Edremit, groundwater, aquifer, hydrogeochemistry, facies

  7. The millennium water vapour drop in the stratosphere in chemistry-climate model simulations

    NASA Astrophysics Data System (ADS)

    Brinkop, Sabine; Dameris, Martin; Joeckel, Patrick; Garny, Hella; Lossow, Stefan; Stiller, Gabriele

    2015-04-01

    This study investigates the millennium water vapour drop, the abrupt and severe water vapour decline in the stratosphere beginning in year 2000, by means of various simulations using the Chemistry-Climate Model (CCM) EMAC. Since the beginning 1980s, balloon borne stratospheric water vapour measurements and corresponding satellite measurements starting in the early 1990s indicated a long-term steady increase of water vapour concentrations. However, the multi-year data sets also show significant fluctuations on different time scales. In the year 2000, an extraordinary sudden drop of stratospheric water vapour concentration has been observed followed by persistent low values for several years. Solomon et al. (2010) showed that this drop slowed down the rate of increase in global surface temperature over the following decade by about 25%. So far, the stratospheric water vapour variations observed by satellite from 1992 to 2012 are not reproduced by CCM simulations forced by observed changes in sea surface temperatures, greenhouse gases and ozone-depleting substances (Gettelman et al., 2010, Randel and Jensen, 2013). However, the CCM EMAC is able to reproduce the signature and pattern of the water vapour disturbances in agreement with those derived from observations. In this paper we present results of a hierarchy of simulations with the CCM EMAC, demonstrating that it is possible to retrace the observed water vapour fluctuations in the stratosphere (incl. the millennium drop), if suitable inner and outer boundary conditions are applied.

  8. Seasonal change in precipitation, snowpack, snowmelt, soil water and streamwater chemistry, northern Michigan

    USGS Publications Warehouse

    Stottlemyer, R.; Toczydlowski, D.

    1999-01-01

    We have studied weekly precipitation, snowpack, snowmelt, soil water and streamwater chemistry throughout winter for over a decade in a small (176 ha) northern Michigan watershed with high snowfall and vegetated by 60 to 80 year-old northern hardwoods. In this paper, we examine physical, chemical, and biological processes responsible for observed seasonal change in streamwater chemistry based upon intensive study during winter 1996-1997. The objective was to define the contributions made to winter and spring streamwater chemical concentration and flux by processes as snowmelt, over-winter forest floor and surface soil mineralization, immobilization, and exchange, and subsurface flowpath. The forest floor and soil were unfrozen beneath the snowpack which permitted most snowmelt to enter. Over-winter soil mineralization and other biological processes maintain shallow subsurface ion and dissolved organic carbon (DOC) reservoirs. Small, but steady, snowmelt throughout winter removed readily mobilized soil NO3- which resulted in high over-winter streamwater concentrations but little flux. Winter soil water levels and flowpaths were generally deep which increased soil water and streamwater base cation (C(B)), HCO3-, and Si concentrations. Spring snowmelt increased soil water levels and removal of ions and DOC from the biologically active forest floor and shallow soils. The snowpack solute content was a minor component in determining streamwater ion concentration or flux during and following peak snowmelt. Exchangeable ions, weakly adsorbed anions, and DOC in the forest floor and surface soils dominated the chemical concentration and flux in soil water and streamwater. Following peak snowmelt, soil microbial immobilization and rapidly increased plant uptake of limiting nutrients removed nearly all available nitrogen from soil water and streamwater. During the growing season high evapotranspiration increased subsurface flowpath depth which in turn removed weathering

  9. Comparative analysis of LWR and FBR spent fuels for nuclear forensics evaluation

    SciTech Connect

    Permana, Sidik; Suzuki, Mitsutoshi; Su'ud, Zaki

    2012-06-06

    Some interesting issues are attributed to nuclide compositions of spent fuels from thermal reactors as well as fast reactors such as a potential to reuse as recycled fuel, and a possible capability to be manage as a fuel for destructive devices. In addition, analysis on nuclear forensics which is related to spent fuel compositions becomes one of the interesting topics to evaluate the origin and the composition of spent fuels from the spent fuel foot-prints. Spent fuel compositions of different fuel types give some typical spent fuel foot prints and can be estimated the origin of source of those spent fuel compositions. Some technics or methods have been developing based on some science and technological capability including experimental and modeling or theoretical aspects of analyses. Some foot-print of nuclear forensics will identify the typical information of spent fuel compositions such as enrichment information, burnup or irradiation time, reactor types as well as the cooling time which is related to the age of spent fuels. This paper intends to evaluate the typical spent fuel compositions of light water (LWR) and fast breeder reactors (FBR) from the view point of some foot prints of nuclear forensics. An established depletion code of ORIGEN is adopted to analyze LWR spent fuel (SF) for several burnup constants and decay times. For analyzing some spent fuel compositions of FBR, some coupling codes such as SLAROM code, JOINT and CITATION codes including JFS-3-J-3.2R as nuclear data library have been adopted. Enriched U-235 fuel composition of oxide type is used for fresh fuel of LWR and a mixed oxide fuel (MOX) for FBR fresh fuel. Those MOX fuels of FBR come from the spent fuels of LWR. Some typical spent fuels from both LWR and FBR will be compared to distinguish some typical foot-prints of SF based on nuclear forensic analysis.

  10. Comparative analysis of LWR and FBR spent fuels for nuclear forensics evaluation

    NASA Astrophysics Data System (ADS)

    Permana, Sidik; Suzuki, Mitsutoshi; Su'ud, Zaki

    2012-06-01

    Some interesting issues are attributed to nuclide compositions of spent fuels from thermal reactors as well as fast reactors such as a potential to reuse as recycled fuel, and a possible capability to be manage as a fuel for destructive devices. In addition, analysis on nuclear forensics which is related to spent fuel compositions becomes one of the interesting topics to evaluate the origin and the composition of spent fuels from the spent fuel foot-prints. Spent fuel compositions of different fuel types give some typical spent fuel foot prints and can be estimated the origin of source of those spent fuel compositions. Some technics or methods have been developing based on some science and technological capability including experimental and modeling or theoretical aspects of analyses. Some foot-print of nuclear forensics will identify the typical information of spent fuel compositions such as enrichment information, burnup or irradiation time, reactor types as well as the cooling time which is related to the age of spent fuels. This paper intends to evaluate the typical spent fuel compositions of light water (LWR) and fast breeder reactors (FBR) from the view point of some foot prints of nuclear forensics. An established depletion code of ORIGEN is adopted to analyze LWR spent fuel (SF) for several burnup constants and decay times. For analyzing some spent fuel compositions of FBR, some coupling codes such as SLAROM code, JOINT and CITATION codes including JFS-3-J-3.2R as nuclear data library have been adopted. Enriched U-235 fuel composition of oxide type is used for fresh fuel of LWR and a mixed oxide fuel (MOX) for FBR fresh fuel. Those MOX fuels of FBR come from the spent fuels of LWR. Some typical spent fuels from both LWR and FBR will be compared to distinguish some typical foot-prints of SF based on nuclear forensic analysis.

  11. Mercury cycling in stream ecosystems. 1. Water column chemistry and transport

    USGS Publications Warehouse

    Brigham, M.E.; Wentz, D.A.; Aiken, G.R.; Krabbenhoft, D.P.

    2009-01-01

    We studied total mercury (THg) and methylmercury (MeHg) in eight streams, located in Oregon, Wisconsin, and Florida, that span large ranges in climate, landscape characteristics, atmospheric Hg deposition, and water chemistry. While atmospheric deposition was the source of Hg at each site, basin characteristics appeared to mediate this source by providing controls on methylation and fluvial THg and MeHg transport. Instantaneous concentrations of filtered total mercury (FTHg) and filtered methylmercury (FMeHg) exhibited strong positive correlations with both dissolved organic carbon (DOC) concentrations and streamflow for most streams, whereas mean FTHg and FMeHg concentrations were correlated with wetland density of the basins. For all streams combined, whole water concentrations (sum of filtered and particulate forms) of THg and MeHg correlated strongly with DOC and suspended sediment concentrations in the water column. ?? 2009 American Chemical Society.

  12. Influence of Water Table Depth on Pore Water Chemistry and Trihalomethane Formation Potential in Peatlands.

    PubMed

    Gough, Rachel; Holliman, Peter J; Fenner, Nathalie; Peacock, Mike; Freeman, Christopher

    2016-02-01

    Drained peatland catchments are reported to produce more colored, dissolved organic carbon (DOC)-rich water, presenting problems for potable water treatment. The blocking of peatland drainage ditches to restore the water table is increasingly being considered as a strategy to address this deterioration in water quality. However, the effect of ditch blocking on the potential of DOC to form trihalomethanes (THMs) has not been assessed. In this study, the effect of peat rewetting on pore water DOC concentration and characteristics (including THM formation potential [THMFP]) was assessed over 12 months using peat cores collected from two drained peatland sites. The data show little evidence of differences in DOC concentration or characteristics between the different treatments. The absence of any difference in the THMFP of pore water between treatments suggests that, in the short term at least, ditch blocking may not have an effect on the THMFP of waters draining peatland catchments. PMID:26803099

  13. Groundwater chemistry near an impoundment for produced water, Powder River Basin, Wyoming, USA

    USGS Publications Warehouse

    Healy, R.W.; Bartos, T.T.; Rice, C.A.; McKinley, M.P.; Smith, B.D.

    2011-01-01

    The Powder River Basin is one of the largest producers of coal-bed natural gas (CBNG) in the United States. An important environmental concern in the Basin is the fate of the large amounts of groundwater extracted during CBNG production. Most of this produced water is disposed of in unlined surface impoundments. A 6-year study of groundwater flow and water chemistry at one impoundment, Skewed Reservoir, has produced the most detailed data set for any impoundment in the Basin. Data were collected from a network of 21 observation wells and three suction lysimeters. A groundwater mound formed atop bedrock within initially unsaturated, unconsolidated deposits underlying the reservoir. Heterogeneity in physical and chemical properties of sediments resulted in complex groundwater flow paths and highly variable groundwater chemistry. Sulfate, bicarbonate, sodium, and magnesium were the dominant ions in all areas, but substantial variability existed in relative concentrations; pH varied from less than 3 to more than 9, and total dissolved solids concentrations ranged from less than 5000 to greater than 100,000. mg/L. Selenium was a useful tracer of reservoir water; selenium concentrations exceeded 300 ??g/L in samples obtained from 18 of the 24 sampling points. Groundwater travel time from the reservoir to a nearby alluvial aquifer (a linear distance of 177. m) was calculated at 474. days on the basis of selenium concentrations. The produced water is not the primary source of solutes in the groundwater. Naturally occurring salts and minerals within the unsaturated zone, dissolved and mobilized by infiltrating impoundment water, account for most of the solute mass in groundwater. Gypsum dissolution, cation-exchange, and pyrite oxidation appear to be important reactions. The complex geochemistry and groundwater flow paths at the study site underscore the difficulty in assessing effects of surface impoundments on water resources within the Powder River Basin. ?? 2011.

  14. Carbonate chemistry of intermediate waters in the Southwest Pacific Ocean since the Last Glacial Maximum

    NASA Astrophysics Data System (ADS)

    Allen, K. A.; Sikes, E. L.; Elmore, A.; Hoenisch, B.; deMenocal, P. B.; Rosenthal, Y.

    2013-12-01

    Shifts in ocean circulation and marine carbon storage likely played an important role in the termination of the last ice age, but the mechanisms driving these changes have not yet been fully explained. It has been suggested that a greater amount of CO2 was stored in the deep sea during glacial periods via the biologic pump and/or increased uptake by a more alkaline ocean. To quantify the relative roles of such processes, more constraints on past deep ocean alkalinity are needed. Here, we present a new record of deep water carbonate chemistry for the last 30,000 years derived from a sediment core located at 1,627 meters depth in New Zealand's Bay of Plenty. Today, this core site lies at the boundary between relatively fresh Antarctic/Tasman Intermediate Water (above), and Circumpolar Deep Water (below) with more corrosive Pacific Deep Water also intruding from the north. Trace element and stable isotopic composition of foraminiferal calcite (the epibenthic species Cibicidoides wuellerstorfi) reveal changes in bottom water carbonate chemistry during periods of atmospheric CO2 change. The boron to calcium ratio (B/Ca) in these shells indicates that deep water saturation (ΔCO32-) during the last glacial maximum (LGM) was only 5 μmol kg-1 less than the modern value of ~ 20 μmol/kg, consistent with previous work identifying the Pacific as a 'well-buffered' ocean basin on long timescales. However, reconstructed ΔCO32- values fluctuated by as much as 30 μmol/kg across the deglaciation, exhibiting the most pronounced changes between 17 and 13 ka. Together with shifts in carbon isotopes, these results imply changes in circulation and/or respired CO2 storage, and support a series of events in which major oceanographic changes are intimately linked with shifts in atmospheric circulation.

  15. Temporal variations of geyser water chemistry in the Upper Geyser Basin, Yellowstone National Park, USA

    USGS Publications Warehouse

    Hurwitz, Shaul; Hunt, Andrew G.; Evans, William C.

    2012-01-01

    Geysers are rare features that reflect a delicate balance between an abundant supply of water and heat and a unique geometry of fractures and porous rocks. Between April 2007 and September 2008, we sampled Old Faithful, Daisy, Grand, Oblong, and Aurum geysers in Yellowstone National Park's Upper Geyser Basin and characterized temporal variations in major element chemistry and water isotopes (δ18O, δD, 3H). We compare these temporal variations with temporal trends of Geyser Eruption Intervals (GEI). SiO2 concentrations and geothermometry indicate that the geysers are fed by waters ascending from a reservoir with temperatures of ∼190 to 210°C. The studied geysers display small and complex chemical and isotopic seasonal variations, and geysers with smaller volume display larger seasonal variations than geysers with larger volumes. Aurum and Oblong Geysers contain detectable tritium concentrations, suggesting that erupted water contains some modern meteoric water. We propose that seasonal GEI variations result from varying degrees of evaporation, meteoric water recharge, water table fluctuations, and possible hydraulic interaction with the adjacent Firehole River. We demonstrate that the concentrations of major dissolved species in Old Faithful Geyser have remained nearly constant since 1884 despite large changes in Old Faithful's eruption intervals, suggesting that no major changes have occurred in the hydrothermal system of the Upper Geyser Basin for >120 years. Our data set provides a baseline for monitoring future changes in geyser activity that might result from varying climate, earthquakes, and changes in heat flow from the underlying magmatic system.

  16. Fog and rain water chemistry at Mt. Fuji: A case study during the September 2002 campaign

    NASA Astrophysics Data System (ADS)

    Watanabe, Koichi; Takebe, Yusaku; Sode, Nobuhiro; Igarashi, Yasuhito; Takahashi, Hiroshi; Dokiya, Yukiko

    2006-12-01

    Measurements of fog and rain water chemistry at the summit of Mt. Fuji, the highest peak in Japan, as well as at Tarobo, the ESE slope of Mt. Fuji in September 2002. The pH of fog and rain water sampled at Mt. Fuji varied over a range of 4.0-6.8. Acidic fogs (pH < 5.0) were observed at the summit when the air mass came from the industrial regions on the Asian continent. The ratio of [SO 42-]/[NO 3-] in the fog water was lower at Tarobo than at the summit. High concentrations of Na + and Cl - were determined in the rain water sampled at the summit, possibly because of the long-range transport of sea-salt particles raised by a typhoon through the middle troposphere. The vertical transport of sea-salt particles would influence the cloud microphysical properties in the middle troposphere. Significant loss of Mg 2+ was seen in the rain water at the summit. The concentrations of peroxides in the fog and rain water were relatively large (10-105 μM). The potential capacity for SO 2 oxidation seems to be strong from summer to early autumn at Mt. Fuji. The fog water peroxide concentrations displayed diurnal variability. The peroxide concentrations in the nighttime were significantly higher than those in the daytime.

  17. Temporal variations of geyser water chemistry in the Upper Geyser Basin, Yellowstone National Park, USA

    NASA Astrophysics Data System (ADS)

    Hurwitz, Shaul; Hunt, Andrew G.; Evans, William C.

    2012-12-01

    Geysers are rare features that reflect a delicate balance between an abundant supply of water and heat and a unique geometry of fractures and porous rocks. Between April 2007 and September 2008, we sampled Old Faithful, Daisy, Grand, Oblong, and Aurum geysers in Yellowstone National Park's Upper Geyser Basin and characterized temporal variations in major element chemistry and water isotopes (δ18O, δD, 3H). We compare these temporal variations with temporal trends of Geyser Eruption Intervals (GEI). SiO2 concentrations and geothermometry indicate that the geysers are fed by waters ascending from a reservoir with temperatures of ˜190 to 210°C. The studied geysers display small and complex chemical and isotopic seasonal variations, and geysers with smaller volume display larger seasonal variations than geysers with larger volumes. Aurum and Oblong Geysers contain detectable tritium concentrations, suggesting that erupted water contains some modern meteoric water. We propose that seasonal GEI variations result from varying degrees of evaporation, meteoric water recharge, water table fluctuations, and possible hydraulic interaction with the adjacent Firehole River. We demonstrate that the concentrations of major dissolved species in Old Faithful Geyser have remained nearly constant since 1884 despite large changes in Old Faithful's eruption intervals, suggesting that no major changes have occurred in the hydrothermal system of the Upper Geyser Basin for >120 years. Our data set provides a baseline for monitoring future changes in geyser activity that might result from varying climate, earthquakes, and changes in heat flow from the underlying magmatic system.

  18. Hydrothermal activity in the Lau back-arc basin: Sulfides and water chemistry

    SciTech Connect

    Fouquet, Y.; Charlou, J.L.; Donval, J.P.; Foucher, J.P. ); von Stackelberg, U.; Wiedicke, M. ); Erzinger, J. ); Herzig, P. ); Muhe, R. ); Soakai, S. ); Whitechurch, H. )

    1991-04-01

    The submersible Nautile completed 22 dives during the Nautilau cruise (R/V Nadir, April 17-May 10, 1989) for a detailed investigation of the southern Lau basin near Tonga. The objective of the scientific team from France, Germany, and Tonga was to understand the process of sea-floor ore formation associated with hydrothermal circulation along the Valu Fa back-arc ridge behind the Tonga-Kermadec trench. The four diving areas, between lat21{degree}25'S and 22{degree}40'S in water{approximately}2000 m deep, were selected on the basis of results from cruises of the R/V Jean Charcot and R/V Sonne. The Nadir cruise provided proof of hydrothermal activity-in all for areas, over more than 100 km-as indicated by the widespread occurence of hydrothermal deposits and by heat flow, conductivity, and temperature measurements near the sea bottom. The most spectacular findings were high-temperature white and black smokers and associated fauna and ore deposits. Hydrothermal water chemistry and sulfide composition data presented here indicate that this hydrothermal field is very different from the hydrothermal fields in oceanic ridges. This difference is seen in water chemistry of the hydrothermal fluid (pH=2 and high metal content) and the chemical composition of sulfides (enrichment in Ba, As, and Pb).

  19. Hydrothermal activity in the Lau back-arc basin:Sulfides and water chemistry

    NASA Astrophysics Data System (ADS)

    Fouquet, Yves; von Stackelberg, Ulrich; Charlou, Jean Luc; Donval, Jean Pierre; Foucher, Jean Paul; Erzinger, Jorg; Herzig, Peter; Mühe, Richard; Wiedicke, Michael; Soakai, Sione; Whitechurch, Hubert

    1991-04-01

    The submersible Nautile completed 22 dives during the Nautilau cruise (R/V Nadir, April 17-May 10, 1989) for a detailed investigation of the southern Lau basin near Tonga. The objective of the scientific team from France, Germany, and Tonga was to understand the process of sea-floor ore formation associated with hydrothermal circulation along the Valu Fa back-arc ridge behind the Tonga- Kermadec trench. The four diving areas, between lat 21°25‧S and 22°40‧S in water ˜2000 m deep, were selected on the basis of results from cruises of the R/V JeanCharcot and R/V Sonne. The Nadir cruise provided proof of hydrothermal activity—in all four areas, over more than 100 km—as indicated by the widespread occurrence of hydrothermal deposits and by heat flow, conductivity, and temperature measurements near the sea bottom. The most spectacular findings were high-temperature white and black smokers and associated fauna and ore deposits. Hydrothermal water chemistry and sulfide composition data presented here indicate that this hydrothermal field is very different from the hydrothermal fields in oceanic ridges. This difference is seen in the water chemistry of the hydrothermal fluid (pH = 2 and high metal content) and the chemical composition of sulfides (enrichment in Ba, As, and Pb).

  20. Geology, Streamflow, and Water Chemistry of the Talufofo Stream Basin, Saipan, Northern Mariana Islands

    USGS Publications Warehouse

    Izuka, Scot K.; Ewart, Charles J., III

    1995-01-01

    A study of the geology, streamflow, and water chemistry of Talufofo Stream Basin, Saipan, Commonwealth of the Northern Mariana Islands, was undertaken to determine the flow characteristics of Talufofo Stream and the relation to the geology of the drainage basin. The Commonwealth government is exploring the feasibility of using water from Talufofo Stream to supplement Saipan's stressed municipal water supply. Streamflow records from gaging stations on the principal forks of Talufofo Stream indicate that peak streamflows and long-term average flow are higher at the South Fork gaging station than at the Middle Fork gaging station because the drainage area of the South Fork gaging station is larger, but persistent base flow from ground-water discharge during dry weather is greater in the Middle Fork gaging station. The sum of the average flows at the Middle Fork and South Fork gaging stations, plus an estimate of the average flow at a point in the lower reaches of the North Fork, is about 2.96 cubic feet per second or 1.91 million gallons per day. Although this average represents the theoretical maximum long-term draft rate possible from the Talufofo Stream Basin if an adequate reservoir can be built, the actual amount of surface water available will be less because of evaporation, leaks, induced infiltration, and reservoir-design constraints. Base-flow characteristics, such as stream seepage and spring discharge, are related to geology of the basin. Base flow in the Talufofo Stream Basin originates as discharge from springs near the base of limestones located in the headwaters of Talufofo Stream, flows over low-permeability volcanic rocks in the middle reaches, and seeps back into the high-permeability limestones in the lower reaches. Water sampled from Talufofo Stream during base flow had high dissolved-calcium concentrations (between 35 and 98 milligrams per liter), characteristic of water from a limestone aquifer. Concentrations of potassium, sodium, and chloride

  1. Environmental Chemistry at Vapor/Water Interfaces: Insights from Vibrational Sum Frequency Generation Spectroscopy

    NASA Astrophysics Data System (ADS)

    Jubb, Aaron M.; Hua, Wei; Allen, Heather C.

    2012-05-01

    The chemistry that occurs at surfaces has been an intense area of study for many years owing to its complexity and importance in describing a wide range of physical phenomena. The vapor/water interface is particularly interesting from an environmental chemistry perspective as this surface plays host to a wide range of chemistries that influence atmospheric and geochemical interactions. The application of vibrational sum frequency generation (VSFG), an inherently surface-specific, even-order nonlinear optical spectroscopy, enables the direct interrogation of various vapor/aqueous interfaces to elucidate the behavior and reaction of chemical species within the surface regime. In this review we discuss the application of VSFG to the study of a variety of atmospherically important systems at the vapor/aqueous interface. Chemical systems presented include inorganic ionic solutions prevalent in aqueous marine aerosols, small molecular solutes, and long-chain fatty acids relevant to fat-coated aerosols. The ability of VSFG to probe both the organization and reactions that may occur for these systems is highlighted. A future perspective toward the application of VSFG to the study of environmental interfaces is also provided.

  2. Multilevel transport solution of LWR reactor cores

    SciTech Connect

    Jose Ignacio Marquez Damian; Cassiano R.E. de Oliveira; HyeonKae Park

    2008-09-01

    This work presents a multilevel approach for the solution of the transport equation in typical LWR assemblies and core configurations. It is based on the second-order, even-parity formulation of the transport equation, which is solved within the framework provided by the finite element-spherical harmonics code EVENT. The performance of the new solver has been compared with that of the standard conjugate gradient solver for diffusion and transport problems on structured and unstruc-tured grids. Numerical results demonstrate the potential of the multilevel scheme for realistic reactor calculations.

  3. Evaluating the effects of variable water chemistry on bacterial transport during infiltration.

    PubMed

    Zhang, Haibo; Nordin, Nahjan Amer; Olson, Mira S

    2013-07-01

    Bacterial infiltration through the subsurface has been studied experimentally under different conditions of interest and is dependent on a variety of physical, chemical and biological factors. However, most bacterial transport studies fail to adequately represent the complex processes occurring in natural systems. Bacteria are frequently detected in stormwater runoff, and may present risk of microbial contamination during stormwater recharge into groundwater. Mixing of stormwater runoff with groundwater during infiltration results in changes in local solution chemistry, which may lead to changes in both bacterial and collector surface properties and subsequent bacterial attachment rates. This study focuses on quantifying changes in bacterial transport behavior under variable solution chemistry, and on comparing the influences of chemical variability and physical variability on bacterial attachment rates. Bacterial attachment rate at the soil-water interface was predicted analytically using a combined rate equation, which varies temporally and spatially with respect to changes in solution chemistry. Two-phase Monte Carlo analysis was conducted and an overall input-output correlation coefficient was calculated to quantitatively describe the importance of physiochemical variation on the estimates of attachment rate. Among physical variables, soil particle size has the highest correlation coefficient, followed by porosity of the soil media, bacterial size and flow velocity. Among chemical variables, ionic strength has the highest correlation coefficient. A semi-reactive microbial transport model was developed within HP1 (HYDRUS1D-PHREEQC) and applied to column transport experiments with constant and variable solution chemistries. Bacterial attachment rates varied from 9.10×10(-3)min(-1) to 3.71×10(-3)min(-1) due to mixing of synthetic stormwater (SSW) with artificial groundwater (AGW), while bacterial attachment remained constant at 9.10×10(-3)min(-1) in a constant

  4. The millennium water vapour drop in chemistry-climate model simulations

    NASA Astrophysics Data System (ADS)

    Brinkop, Sabine; Dameris, Martin; Jöckel, Patrick; Garny, Hella; Lossow, Stefan; Stiller, Gabriele

    2016-07-01

    This study investigates the abrupt and severe water vapour decline in the stratosphere beginning in the year 2000 (the "millennium water vapour drop") and other similarly strong stratospheric water vapour reductions by means of various simulations with the state-of-the-art Chemistry-Climate Model (CCM) EMAC (ECHAM/MESSy Atmospheric Chemistry Model). The model simulations differ with respect to the prescribed sea surface temperatures (SSTs) and whether nudging is applied or not. The CCM EMAC is able to most closely reproduce the signature and pattern of the water vapour drop in agreement with those derived from satellite observations if the model is nudged. Model results confirm that this extraordinary water vapour decline is particularly obvious in the tropical lower stratosphere and is related to a large decrease in cold point temperature. The drop signal propagates under dilution to the higher stratosphere and to the poles via the Brewer-Dobson circulation (BDC). We found that the driving forces for this significant decline in water vapour mixing ratios are tropical sea surface temperature (SST) changes due to a coincidence with a preceding strong El Niño-Southern Oscillation event (1997/1998) followed by a strong La Niña event (1999/2000) and supported by the change of the westerly to the easterly phase of the equatorial stratospheric quasi-biennial oscillation (QBO) in 2000. Correct (observed) SSTs are important for triggering the strong decline in water vapour. There are indications that, at least partly, SSTs contribute to the long period of low water vapour values from 2001 to 2006. For this period, the specific dynamical state of the atmosphere (overall atmospheric large-scale wind and temperature distribution) is important as well, as it causes the observed persistent low cold point temperatures. These are induced by a period of increased upwelling, which, however, has no corresponding pronounced signature in SSTs anomalies in the tropics. Our free

  5. Chemistry of calcium carbonate-rich shallow water sediments in the Bahamas

    SciTech Connect

    Morse, J.W.; Zullig, J.J.; Bernstein, L.D.; Millero, F.J.; Milne, P.; Mucci, A.; Choppin, G.R.

    1985-02-01

    The geochemistry of calcium carbonate-rich sediments from a variety of environments throughout the Bahamas was investigated with particular emphasis on the factors that control the pore water chemistry. Most sediments are supersaturated with respect to aragonite, the most abundant carbonate component. Experimental studies indicate that the observed in situ calcium carbonate ion activity products can often be produced as reversible metastable equilibria between the sediments and seawater. This is interpreted as being the result of interactions between the solutions and the minor high Mg-calcite component present in these sediments. Although the overlying waters are more supersaturated than the pore waters, carbonate dissolution, not precipitation, dominates in these sediments as a result of organic matter oxidation and the resulting increase in P/sub CO/sub 2//. The carbonate sediments of the Bahamas are remarkable for their purity, with the exception of special environments such as mangrove swamps and tidal flats with algal mats. Organic matter and heavy metal content is extremely low. Only minor sulfate reduction is occurring in most sediments. Phosphate is undetectable in all pore waters, probably as a result of adsorption on carbonate mineral surfaces. Other dissolved pore water components such as ammonia and DOC are much lower than typically found in shallow water fine-grained terrigeneous sediments.

  6. Microbiology of Broiler Carcasses and Chemistry of Chiller Water as Affected by Water Reuse

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted to determine the effects of treating and reusing poultry chiller water in a commercial poultry processing facility. Broiler carcasses and chiller water were obtained from a commercial processing facility which had recently installed a TOMCO Pathogen Management SystemJ to recyc...

  7. The millennium water vapour drop in chemistry-climate model simulations

    NASA Astrophysics Data System (ADS)

    Brinkop, S.; Dameris, M.; Jöckel, P.; Garny, H.; Lossow, S.; Stiller, G.

    2015-09-01

    This study investigates the abrupt and severe water vapour decline in the stratosphere beginning in year 2000 (the "millennium water vapour drop") and other similar stratospheric water vapour drops by means of various simulations with the state-of-the-art Chemistry-Climate Model (CCM) EMAC (ECHAM/MESSy Atmospheric Chemistry Model). The CCM EMAC is able to reproduce the signature and pattern of the water vapour disturbances in agreement with those derived from satellite observations. Model data confirm that this extraordinary water vapour decline is in particular obvious in the tropical lower stratosphere. The starting point of the severe water vapour drop is identified in the tropical lower stratosphere and the start date is found to be in the early days of 2000. We show that the driving forces for this significant drop in water vapour mixing ratios are tropical sea surface temperature changes due to a preceding strong El Niño-Southern Oscillation event (1997/98), which was followed by a La Niña and supported by the prevailing western phase of the equatorial stratospheric quasi-biennial oscillation (QBO) at that time. This constellation of ENSO and QBO obviously lead to the outstanding anomalies in meteorological quantities which are identified in the equatorial atmosphere: (a) a distinct warming (up to 1 K) of the tropical upper troposphere (200 to 120 hPa) beginning in mid-1997 and lasting for about one and a half years, (b) a strong warming (up to 2.5 K) of the tropical lower stratosphere (100 to 50 hPa), beginning in early 1999 and ending in early 2000, and (c) a significantly enhanced upwelling at the tropopause in the late 1990s and an obviously reduced upwelling around the year 2000 followed by a period of enhanced upwelling again. These dynamically induced changes are unambiguously connected to the stratospheric water vapour anomaly. Similarly strong water vapour reductions are also found in other years, and seem to be a~typical feature after strong

  8. AOTVAL_pharto01_2: Water and Related Chemistry in the Solar System

    NASA Astrophysics Data System (ADS)

    Hartogh, P.

    2012-12-01

    Water is ubiquitous in the Solar System, being present in gaseous form in all planetary and cometary atmospheres, as ice on the surface and subsurface of Mars, comets, most planetary satellites and distant bodies, and in the liquid phase on Earth. Water plays an important or dominant role in the chemistry of planetary and cometary atmospheres. Comets are sources of water for planets through episodic collisions and continuous production of ice-dust grains. This proposal addresses the broad topic of water and its isotopologues in planetary and cometary atmospheres. The nature of cometary activity and the thermodynamics of cometary comae will be investigated by studying water excitation in a sample of comets. The D/H ratio, the key for constraining the origin and evolution of Solar System species, will be measured for the first time in a Jupiter- family comet. A comparison with existing and new measurements of D/H in Oort-cloud comets will constrain the composition of pre-solar cometary grains and possibly the dynamics of the protosolar nebula. New measurements of D/H in Giant Planets, similarly constraining the composition of proto-planetary ices, will be obtained. The D/H and other isotopic ratios, diagnostic of Mars' atmosphere evolution, will be accurately measured in H2O and CO. The role of water vapor in Mars' atmospheric chemistry will be studied by monitoring vertical profiles of H2O and HDO and by searching for several other species. A detailed study of the source of water in the upper atmosphere of the Giant Planets and Titan will be performed. By monitoring the water abundance, vertical profile, and input fluxes in the various objects, and when possible with the help of mapping observations, we will discriminate between the possible sources of water in the outer planets (interplanetary dust particles, cometary impacts, and local sources). In addition to these inter-connected objectives, serendipitous searches will enhance our knowledge of the composition of

  9. SDP_pharto01_3: Water and Related Chemistry in the Solar System

    NASA Astrophysics Data System (ADS)

    Hartogh, P.

    2012-12-01

    Water is ubiquitous in the Solar System, being present in gaseous form in all planetary and cometary atmospheres, as ice on the surface and subsurface of Mars, comets, most planetary satellites and distant bodies, and in the liquid phase on Earth. Water plays an important or dominant role in the chemistry of planetary and cometary atmospheres. Comets are sources of water for planets through episodic collisions and continuous production of ice-dust grains. This proposal addresses the broad topic of water and its isotopologues in planetary and cometary atmospheres. The nature of cometary activity and the thermodynamics of cometary comae will be investigated by studying water excitation in a sample of comets. The D/H ratio, the key for constraining the origin and evolution of Solar System species, will be measured for the first time in a Jupiter- family comet. A comparison with existing and new measurements of D/H in Oort-cloud comets will constrain the composition of pre-solar cometary grains and possibly the dynamics of the protosolar nebula. New measurements of D/H in Giant Planets, similarly constraining the composition of proto-planetary ices, will be obtained. The D/H and other isotopic ratios, diagnostic of Mars' atmosphere evolution, will be accurately measured in H2O and CO. The role of water vapor in Mars' atmospheric chemistry will be studied by monitoring vertical profiles of H2O and HDO and by searching for several other species. A detailed study of the source of water in the upper atmosphere of the Giant Planets and Titan will be performed. By monitoring the water abundance, vertical profile, and input fluxes in the various objects, and when possible with the help of mapping observations, we will discriminate between the possible sources of water in the outer planets (interplanetary dust particles, cometary impacts, and local sources). In addition to these inter-connected objectives, serendipitous searches will enhance our knowledge of the composition of

  10. Hydrogeologic controls of surface-water chemistry in the Adirondack region of New York State

    USGS Publications Warehouse

    Peters, N.E.; Driscoll, C.T.

    1987-01-01

    Relationships between surface-water discharge, water chemistry, and watershed geology were investigated to evaluate factors affecting the sensitivity of drainage waters in the Adirondack region of New York to acidification by atmospheric deposition. Instantaneous discharge per unit area was derived from relationships between flow and staff-gage readings at 10 drainage basins throughout the region. The average chemical composition of the waters was assessed from monthly samples collected from July 1982 through July 1984. The ratio of flow at the 50-percent exceedence level to the flow at the 95-percent exceedence level of flow duration was negatively correlated with mean values of alkalinity or acid-neutralizing capacity (ANC), sum of basic cations (SBC), and dissolved silica, for basins containing predominantly aluminosilicate minerals and little or no carbonate-bearing minerals. Low ratios are indicative of systems in which flow is predominately derived from surface- and ground-water storage, whereas high ratios are characteristic of watersheds with variable flow that is largely derived from surface runoff. In an evaluation of two representative surface-water sites, concentrations of ANC, SBC, and dissolved silica, derived primarily from soil mineral weathering reactions. decreased with increasing flow. Furthermore, the ANC was highest at low flow when the percentage of streamflow derived from ground water was maximum. As flow increased, the ANC decreased because the contribution of dilute surface runoff and lateral flow through the shallow acidic soil horizons to total flow increased. Basins having relatively high ground-water contributions to total flow, in general, have large deposits of thick till or stratified drift. A major factor controlling the sensitivity of these streams and lakes to acidification is the relative contribution of ground water to total discharge. ?? 1987 Martinus Nijhoff/Dr W. Junk Publishers.

  11. Variation of Fraser Valley, British Columbia, Tributary Streams Water Chemistry, 2010 to 2014.

    NASA Astrophysics Data System (ADS)

    Marsh, S. J.; Gillies, S. L.; Ehrenbrink, B. P. E.; Voss, B.; Bulygina, E.; Fiske, G. J.; Birdwhistell, S.; Janmaat, A.; Yakemchuk, A.; Smith, S.; Faber, A.; Luymes, R.; Epp, A.; Bennett, M. C.; Fanslau, J.; Downey, B.; Wiebe, B.; VanKoughnett, H.; Macklam-Harron, G.; Herbert, J.

    2014-12-01

    The University of the Fraser Valley has undertaken the time series sampling of water chemistry of the Fraser River at Fort Langley, British Columbia and five Fraser Valley tributary creeks as a member of the Global Rivers Observatory (GRO, www.globalrivers.org) which is coordinated by Woods Hole Oceanographic Institutionand Woods Hole Research Center. Kanaka Creek (Maple Ridge), Silverdale Creek (Mission), Clayburn Creek, Willband Creek and Nathan Creek (Abbotsford) have been sampled as part of the GRO. The creeks have been sampled for nutrient concentrations (silicate, phosphate, nitrate/nitrite, and ammonium), major ions and water chemistry parameters, such as dissolved oxygen, temperature, conductivity, pH, and turbidity monthly over the past four years. Each of these salmon bearing creeks is being threatened by anthropogenic activity (agricultural, industrial and residential development) that is occurring in the watersheds. Nathan and Willband Creeks are being threatened by agricultural activity, while Kanaka, Clayburn and Silverdale Creeks are being threatened by residential developments. Understanding these changes and their seasonal variations is crucial in assisting in protecting the natural habitat of these watersheds and streams.

  12. An Empirical Approach to Predicting Effects of Climate Change on Stream Water Chemistry

    NASA Astrophysics Data System (ADS)

    Olson, J. R.; Hawkins, C. P.

    2014-12-01

    Climate change may affect stream solute concentrations by three mechanisms: dilution associated with increased precipitation, evaporative concentration associated with increased temperature, and changes in solute inputs associated with changes in climate-driven weathering. We developed empirical models predicting base-flow water chemistry from watershed geology, soils, and climate for 1975 individual stream sites across the conterminous USA. We then predicted future solute concentrations (2065 and 2099) by applying down-scaled global climate model predictions to these models. The electrical conductivity model (EC, model R2 = 0.78) predicted mean increases in EC of 19 μS/cm by 2065 and 40 μS/cm by 2099. However predicted responses for individual streams ranged from a 43% decrease to a 4x increase. Streams with the greatest predicted decreases occurred in the southern Rocky Mountains and Mid-West, whereas southern California and Sierra Nevada streams showed the greatest increases. Generally, streams in dry areas underlain by non-calcareous rocks were predicted to be the most vulnerable to increases in EC associated with climate change. Predicted changes in other water chemistry parameters (e.g., Acid Neutralization Capacity (ANC), SO4, and Ca) were similar to EC, although the magnitude of ANC and SO4 change was greater. Predicted changes in ANC and SO4 are in general agreement with those changes already observed in seven locations with long term records.

  13. Analysis of southeastern Canada lake-water chemistry data in relation to acidic deposition

    SciTech Connect

    Olson, R.J.; Cook, R.B.; Ross-Todd, B.M.; Beauchamp, J.J.

    1990-05-01

    Lake-water chemistry data were obtained for lakes in southeastern Canada to study relationships between atmospheric deposition and acid-base chemistry as part of the National Acid Precipitation Assessment Program State of Science and Technology reports. Quality assurance checks were made to ensure that the data used were of sufficient quality and were comparable to data from the United States. Ninety-eight percent of the 8506 sampled lakes had pH, ANC, and SO{sub 4}{sup 2 {minus}} data and were used in our analyses. Of these, we created a subset of 4017 lakes having data for more variable (Ca{sup 2+}, Mg{sup 2+}, Na{sup +}, K{sup +}, DOC, and conductivity) to analyze potential sources of lake-water acidity. The objectives of this work were to determine the geographical extent and number of potentially affected systems and to infer causes of acidification based on ion ratios. 35 refs., 28 figs., 12 tabs.

  14. High-pressure photodissociation of water as a tool for hydrogen synthesis and fundamental chemistry

    PubMed Central

    Ceppatelli, Matteo; Bini, Roberto; Schettino, Vincenzo

    2009-01-01

    High-pressure methods have been demonstrated to be efficient in providing new routes for the synthesis of materials of technological interest. In several molecular compounds, the drastic pressure conditions required for spontaneous transformations have been lowered to the kilobar range by photoactivation of the reactions. At these pressures, the syntheses are accessible to large-volume applications and are of interest to bioscience, space, and environmental chemistry. Here, we show that the short-lived hydroxyl radicals, produced in the photodissociation of water molecules by near-UV radiation at room temperature and pressures of a few tenths of a gigapascal (GPa), can be successfully used to trigger chemical reactions in mixtures of water with carbon monoxide or nitrogen. The detection of molecular hydrogen among the reaction products is of particular relevance. Besides the implications in fundamental chemistry, the mild pressure and irradiation conditions, the efficiency of the process, and the nature of the reactant and product molecules suggest applications in synthesis. PMID:19581572

  15. Prebiotic chemistry in eutectic solutions at the water-ice matrix.

    PubMed

    Menor-Salván, César; Marín-Yaseli, Margarita R

    2012-08-21

    A crystalline ice matrix at subzero temperatures can maintain a liquid phase where organic solutes and salts concentrate to form eutectic solutions. This concentration effect converts the confined reactant solutions in the ice matrix, sometimes making condensation and polymerisation reactions occur more favourably. These reactions occur at significantly high rates from a prebiotic chemistry standpoint, and the labile products can be protected from degradation. The experimental study of the synthesis of nitrogen heterocycles at the ice-water system showed the efficiency of this scenario and could explain the origin of nucleobases in the inner Solar System bodies, including meteorites and extra-terrestrial ices, and on the early Earth. The same conditions can also favour the condensation of monomers to form ribonucleic acid and peptides. Together with the synthesis of these monomers, the ice world (i.e., the chemical evolution in the range between the freezing point of water and the limit of stability of liquid brines, 273 to 210 K) is an under-explored experimental model in prebiotic chemistry. PMID:22660387

  16. Modeling water chemistry change and contaminant transport in riverbank filtration systems

    NASA Astrophysics Data System (ADS)

    Mustafa, Shaymaa; Bahar, Arifah; Aziz, Zainal Abdul; Suratman, Saim

    2016-06-01

    Riverbank filtration system is river water treatment approach based on natural removal of contaminants due to physical, chemical and biological processes. In this article, an analytical model is developed by using Green's function method to simulate the effects of pumping well and microbial activity that occurs in riverbed sediments on contaminant transport and evolution of water chemistry. The model is tested with data collected previously for RBF site in France. The results are compared with numerical simulation conducted in the literature by using finite difference method. Graphically, it is noticed that both numerical and analytical results have almost the same behavior. Also it is found that the model can simulate the decreasing of one pollutant concentration at the zone where the bacteria starts to consume this pollutant.

  17. LIFE vs. LWR: End of the Fuel Cycle

    SciTech Connect

    Farmer, J C; Blink, J A; Shaw, H F

    2008-10-02

    The worldwide energy consumption in 2003 was 421 quadrillion Btu (Quads), and included 162 quads for oil, 99 quads for natural gas, 100 quads for coal, 27 quads for nuclear energy, and 33 quads for renewable sources. The projected worldwide energy consumption for 2030 is 722 quads, corresponding to an increase of 71% over the consumption in 2003. The projected consumption for 2030 includes 239 quads for oil, 190 quads for natural gas, 196 quads for coal, 35 quads for nuclear energy, and 62 quads for renewable sources [International Energy Outlook, DOE/EIA-0484, Table D1 (2006) p. 133]. The current fleet of light water reactors (LRWs) provides about 20% of current U.S. electricity, and about 16% of current world electricity. The demand for electricity is expected to grow steeply in this century, as the developing world increases its standard of living. With the increasing price for oil and gasoline within the United States, as well as fear that our CO2 production may be driving intolerable global warming, there is growing pressure to move away from oil, natural gas, and coal towards nuclear energy. Although there is a clear need for nuclear energy, issues facing waste disposal have not been adequately dealt with, either domestically or internationally. Better technological approaches, with better public acceptance, are needed. Nuclear power has been criticized on both safety and waste disposal bases. The safety issues are based on the potential for plant damage and environmental effects due to either nuclear criticality excursions or loss of cooling. Redundant safety systems are used to reduce the probability and consequences of these risks for LWRs. LIFE engines are inherently subcritical, reducing the need for systems to control the fission reactivity. LIFE engines also have a fuel type that tolerates much higher temperatures than LWR fuel, and has two safety systems to remove decay heat in the event of loss of coolant or loss of coolant flow. These features of

  18. Research in Physical Chemistry and Chemical Education: Part A--Water Mediated Chemistry of Oxidized Atmospheric Compounds Part B--The Development of Surveying Tools to Determine How Effective Laboratory Experiments Contribute to Student Conceptual Understanding

    ERIC Educational Resources Information Center

    Maron, Marta Katarzyna

    2011-01-01

    This dissertation is a combination of two research areas, experimental physical chemistry, Chapters I to V, and chemical education, Chapters VI to VII. Chapters I to V describe research on the water-mediated chemistry of oxidized atmospheric molecules and the impact that water has on the spectra of these environmental systems. The role of water…

  19. A study of water chemistry extends the benefits of using silica-based nanoparticles on enhanced oil recovery

    NASA Astrophysics Data System (ADS)

    Hendraningrat, Luky; Torsæter, Ole

    2016-01-01

    Chemistry of the injected water has been investigated as an important parameter to improve/enhance oil recovery (IOR/EOR). Numerous extensive experiments have observed that water chemistry, such as ionic composition and salinity, can be modified for IOR/EOR purposes. However, the possible oil displacement mechanism remains debatable. Nanoparticle recently becomes more popular that have shown a great potential for IOR/EOR purposes in lab-scale, where in most experiments, water-based fluid were used as dispersed fluid. As yet, there has been no discussion in the literature on the study of water chemistry on enhanced oil recovery using silica-based nanoparticles. A broad range of laboratory studies involving rock, nanoparticles and fluid characterization; fluid-fluid and fluid-rock interactions; surface conductivity measurement; coreflood experiment; injection strategy formulation; filtration mechanism and contact angle measurement are conducted to investigate the impact of water chemistry, such as water salinity and ionic composition including hardness cations, on the performance of silica-based nanoparticles in IOR/EOR process and reveal possible displacement mechanism. The experimental results demonstrated that water salinity and ionic composition significantly impacted oil recovery using hydrophilic silica-based nanoparticles and that the oil recovery increased with the salinity. The primary findings from this study are that the water salinity, the ionic composition and the injection strategy are important parameters to be considered in Nano-EOR.

  20. Hydrology and Species-Specific Effects of Bacopa monnieri and Leersia oryzoides on Soil and Water Chemistry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In an eight week greenhouse experiment, Bacopa monnieri (Water Hyssop) and Leersia oryzoides (Rice Cutgrass) were compared for nutrient assimilation as well as soil and water chemistry under variable flooding regimes using a nutrient solution rich in nitrogen (N) and phosphorus (P). Soil redox poten...

  1. Water as Life, Death, and Power: Building an Integrated Interdisciplinary Course Combining Perspectives from Anthropology, Biology, and Chemistry

    ERIC Educational Resources Information Center

    Willermet, Cathy; Mueller, Anja; Juris, Stephen J.; Drake, Eron; Upadhaya, Samik; Chhetri, Pratik

    2013-01-01

    In response to a request from a campus student organization, faculty from three fields came together to develop and teach an integrated interdisciplinary course on water issues and social activism. This course, "Water as Life, Death, and Power", brought together topics from the fields of anthropology, biology and chemistry to explore…

  2. Precipitation and river water chemistry of the Piracicaba River basin, southeast Brazil.

    PubMed

    Williams, M R; Filoso, S; Martinelli, L A; Lara, L B; Camargo, P B

    2001-01-01

    Annual precipitation and river water volumes and chemistry were measured from 1995 to 1998 in a mesoscale agricultural area of southeast Brazil. Precipitation was mildly acidic and solute concentrations were higher in the west than in the east of the basin. Combustion products from biomass burning, automobile exhaust, and industry typically accumulate in the atmosphere from March until October and are responsible for seasonal differences observed in precipitation chemistry. In river waters, the volume-weighted mean (VWM) concentrations of major solutes at 10 sites across the basin were generally lower at upriver than at downriver sampling sites for most solutes. Mass balances for major solutes indicate that, as a regional entity, the Piracicaba River basin was a net sink of H+, PO4(3-), and NH4+, and a net source of other solutes. The main stem of the Piracicaba River had a general increase in solute concentrations from upriver to downriver sampling sites. In contrast, NO3- and NH4+ concentrations increased in the mid-reach sampling sites and decreased due to immobilization or utilization in the mid-reach reservoir, and there was denitrification immediately downriver of this reservoir. Compared with tributaries of the Chesapeake Bay estuary, the Piracicaba River is affected more by point-source inputs of raw sewage and industrial wastes than nonpoint agricultural runoff high in N and P. Inputs of N and C are responsible for a degradation of water quality at downriver sampling sites of the Piracicaba River drainage, and water quality could be considerably improved by augmenting sewage treatment. PMID:11401288

  3. Controls on surface water chemistry in the upper Merced River basin, Yosemite National Park, California

    USGS Publications Warehouse

    Clow, D.W.; Mast, M.A.; Campbell, D.H.

    1996-01-01

    Surface water draining granitic bedrock in Yosemite National Park exhibits considerable variability in chemical composition, despite the relative homogeneity of bedrock chemistry. Other geological factors, including the jointing and distribution of glacial till, appear to exert strong controls on water composition. Chemical data from three surface water surveys in the upper Merced River basin conducted in August 1981, June 1988 and August 1991 were analysed and compared with mapped geological, hydrological and topographic features to identify the solute sources and processes that control water chemistry within the basin during baseflow. Water at most of the sampling sites was dilute, with alkalinities ranging from 26 to 77 ??equiv. 1-1. Alkalinity was much higher in two subcatchments, however, ranging from 51 to 302 ??equiv. 1-1. Base cations and silica were also significantly higher in these two catchments than in the rest of the watershed. Concentrations of weathering products in surface water were correlated to the fraction of each subcatchment underlain by surficial material, which is mostly glacial till. Silicate mineral weathering is the dominant control on concentrations of alkalinity, silica and base cations, and ratios of these constituents in surface water reflect the composition of local bedrock, Chloride concentrations in surface water samples varied widely, ranging from <1 to 96 ??equiv. 1-1. The annual volume-weighted mean chloride concentration in the Merced River at the Happy Isles gauge from 1968 to 1990 was 26 ??equiv. 1-1, which was five times higher than in atmospheric deposition (4-5 ??equiv. 1-1), suggesting that a source of chloride exists within the watershed. Saline groundwater springs, whose locations are probably controlled by vertical jointing in the bedrock, are the most likely source of the chloride. Sulphate concentrations varied much less than most other solutes, ranging from 3 to 14 ??equiv. 1-1. Concentrations of sulphate in

  4. Fracture control of ground water flow and water chemistry in a rock aquitard

    USGS Publications Warehouse

    Eaton, T.T.; Anderson, M.P.; Bradbury, K.R.

    2007-01-01

    There are few studies on the hydrogeology of sedimentary rock aquitards although they are important controls in regional ground water flow systems. We formulate and test a three-dimensional (3D) conceptual model of ground water flow and hydrochemistry in a fractured sedimentary rock aquitard to show that flow dynamics within the aquitard are more complex than previously believed. Similar conceptual models, based on regional observations and recently emerging principles of mechanical stratigraphy in heterogeneous sedimentary rocks, have previously been applied only to aquifers, but we show that they are potentially applicable to aquitards. The major elements of this conceptual model, which is based on detailed information from two sites in the Maquoketa Formation in southeastern Wisconsin, include orders of magnitude contrast between hydraulic diffusivity (K/Ss) of fractured zones and relatively intact aquitard rock matrix, laterally extensive bedding-plane fracture zones extending over distances of over 10 km, very low vertical hydraulic conductivity of thick shale-rich intervals of the aquitard, and a vertical hydraulic head profile controlled by a lateral boundary at the aquitard subcrop, where numerous surface water bodies dominate the shallow aquifer system. Results from a 3D numerical flow model based on this conceptual model are consistent with field observations, which did not fit the typical conceptual model of strictly vertical flow through an aquitard. The 3D flow through an aquitard has implications for predicting ground water flow and for planning and protecting water supplies. ?? 2007 National Ground Water Association.

  5. Anthropogenic impact on water chemistry and benthic macroinvertebrate associated changes in a southern Nigeria stream.

    PubMed

    Arimoro, Francis O; Odume, O Nelson; Uhunoma, Samson I; Edegbene, Augustine O

    2015-02-01

    The Ogba River in southern Nigeria is an important water resource for its riparian communities. This study evaluates impact of anthropogenic influences on the Ogba River using water chemistry and macroinvertebrate data sets obtained over a period of 6 months between January and June 2012. Four stations, stations 1-4, characterised by various human activities were chosen along the river. Organic wastes from domestic and industrial sources were the major point sources of pollutants. Station 2 where the municipal wastewater drains into the river had elevated values of flow velocity, BOD5, sulphate, phosphate, nitrate and sodium. Based on the canonical correspondence analysis (CCA), 5-day biochemical oxygen demand (BOD5), sulphate, nitrate and phosphate were the main factors that help to shape the macroinvertebrate assemblage structure of the Ogba River. Macroinvertebrates clustered strongly by stations than by seasons indicating that water quality differences between the stations were responsible for the observed differences in the biotic assemblage. The preponderance of naidid oligochaetes, baetid nymphs and certain tolerant dipteran taxa including chironomids and ceratopogonids at all four stations was an indication that the entire water body was stressed. The odonates were the single most abundant taxa; their dominance could be attributed to the vegetative nature of the stream, favouring odonate colonisation. Overall, the responses of macroinvertebrates to stress were reflected by the different assemblage structures recorded at the four study stations. Substrate and microhabitat obliteration and poor water quality appeared to be the factors responsible for the observed assemblage structure in the Ogba River. PMID:25619697

  6. Links between climate change, water-table depth, and water chemistry in a mineralized mountain watershed

    USGS Publications Warehouse

    Manning, Andrew H.; Verplanck, Philip L.; Caine; Todd, Andrew S.

    2013-01-01

    Recent studies suggest that climate change is causing rising solute concentrations in mountain lakes and streams. These changes may be more pronounced in mineralized watersheds due to the sensitivity of sulfide weathering to changes in subsurface oxygen transport. Specific causal mechanisms linking climate change and accelerated weathering rates have been proposed, but in general remain entirely hypothetical. For mineralized watersheds, a favored hypothesis is that falling water tables caused by declining recharge rates allow an increasing volume of sulfide-bearing rock to become exposed to air, thus oxygen. Here, we test the hypothesis that falling water tables are the primary cause of an increase in metals and SO4 (100-400%) observed since 1980 in the Upper Snake River (USR), Colorado. The USR drains an alpine watershed geologically and climatologically representative of many others in mineralized areas of the western U.S. Hydrologic and chemical data collected from 2005 to 2011 in a deep monitoring well (WP1) at the top of the USR watershed are utilized. During this period, both water table depths and groundwater SO4 concentrations have generally increased in the well. A numerical model was constructed using TOUGHREACT that simulates pyrite oxidation near WP1, including groundwater flow and oxygen transport in both saturated and unsaturated zones. The modeling suggests that a falling water table could produce an increase in metals and SO4 of a magnitude similar to that observed in the USR (up to 300%). Future water table declines may produce limited increases in sulfide weathering high in the watershed because of the water table dropping below the depth of oxygen penetration, but may continue to enhance sulfide weathering lower in the watershed where water tables are shallower. Advective air (oxygen) transport in the unsaturated zone caused by seasonally variable recharge and associated water table fluctuations was found to have little influence on pyrite

  7. Changing carbonate chemistry in ocean waters surrounding coral reefs in the CMIP5 ensemble

    NASA Astrophysics Data System (ADS)

    Ricke, K.; Schneider, K.; Cao, L.; Caldeira, K.

    2012-12-01

    Coral reefs comprise some of the most biodiverse ecosystems in the world. Today they are threatened by a number of stressors, including pollution, bleaching from global warming and ocean acidification. In this study, we focus on the implications of ocean acidification for the open ocean chemistry surrounding coral reefs. We use results from 13 Earth System Models included in the Coupled Model Intercomparison Project 5 (CMIP5) to examine the changing aragonite saturations (Ωa) of open ocean waters surrounding approximately 6,000 coral reefs. These 13 Earth System Models participating in CMIP5 each have interactive ocean biogeochemistry models that output state variables including DIC, alkalinity, SST, and salinity. Variation in these values were combined with values from the GLODAP database to calculate aragonite, the form of calcium carbonate that corals use to make their skeletons. We used reef locations from ReefBase that were within one degree (in latitude or longitude) of water masses represented both in the GLODAP database and in the climate models. Carbonate chemistry calculations were performed by Dr. James C. Orr (IPSL) as part of a separate study. We find that in preindustrial times, 99.9 % of coral reefs were located in regions of the ocean with aragonite saturations of 3.5 or more. The saturation threshold for viable reef ecosystems in uncertain, but the pre-industrial distribution of water chemistry surrounding coral reefs may nevertheless provide some indication of viability. We examine the fate of coral reefs in the context of several potential aragonite saturation thresholds, i.e., when Ωa_crit equals 3, 3.25, or 3.5. We show that under a business-as-usual scenario Representative Concentration Pathway (RCP) 8.5, the specific value of Ωa_crit does not affect the long-term fate of coral reefs -- by the end of the 21st century, no coral reef considered is surrounded by water with Ωa> 3. However, under scenarios with significant CO2 emissions

  8. Impact of Water Chemistry, Pipe Material and Stagnation on the Building Plumbing Microbiome.

    PubMed

    Ji, Pan; Parks, Jeffrey; Edwards, Marc A; Pruden, Amy

    2015-01-01

    A unique microbiome establishes in the portion of the potable water distribution system within homes and other buildings (i.e., building plumbing). To examine its composition and the factors that shape it, standardized cold water plumbing rigs were deployed at the treatment plant and in the distribution system of five water utilities across the U.S. Three pipe materials (copper with lead solder, CPVC with brass fittings or copper/lead combined pipe) were compared, with 8 hour flush cycles of 10 minutes to simulate typical daily use patterns. High throughput Illumina sequencing of 16S rRNA gene amplicons was employed to profile and compare the resident bulk water bacteria and archaea. The utility, location of the pipe rig, pipe material and stagnation all had a significant influence on the plumbing microbiome composition, but the utility source water and treatment practices were dominant factors. Examination of 21 water chemistry parameters suggested that the total chlorine concentration, pH, P, SO42- and Mg were associated with the most of the variation in bulk water microbiome composition. Disinfectant type exerted a notably low-magnitude impact on microbiome composition. At two utilities using the same source water, slight differences in treatment approaches were associated with differences in rare taxa in samples. For genera containing opportunistic pathogens, Utility C samples (highest pH of 9-10) had the highest frequency of detection for Legionella spp. and lowest relative abundance of Mycobacterium spp. Data were examined across utilities to identify a true universal core, special core, and peripheral organisms to deepen insight into the physical and chemical factors that shape the building plumbing microbiome. PMID:26495985

  9. Impact of Water Chemistry, Pipe Material and Stagnation on the Building Plumbing Microbiome

    PubMed Central

    Ji, Pan; Parks, Jeffrey; Edwards, Marc A.; Pruden, Amy

    2015-01-01

    A unique microbiome establishes in the portion of the potable water distribution system within homes and other buildings (i.e., building plumbing). To examine its composition and the factors that shape it, standardized cold water plumbing rigs were deployed at the treatment plant and in the distribution system of five water utilities across the U.S. Three pipe materials (copper with lead solder, CPVC with brass fittings or copper/lead combined pipe) were compared, with 8 hour flush cycles of 10 minutes to simulate typical daily use patterns. High throughput Illumina sequencing of 16S rRNA gene amplicons was employed to profile and compare the resident bulk water bacteria and archaea. The utility, location of the pipe rig, pipe material and stagnation all had a significant influence on the plumbing microbiome composition, but the utility source water and treatment practices were dominant factors. Examination of 21 water chemistry parameters suggested that the total chlorine concentration, pH, P, SO42- and Mg were associated with the most of the variation in bulk water microbiome composition. Disinfectant type exerted a notably low-magnitude impact on microbiome composition. At two utilities using the same source water, slight differences in treatment approaches were associated with differences in rare taxa in samples. For genera containing opportunistic pathogens, Utility C samples (highest pH of 9–10) had the highest frequency of detection for Legionella spp. and lowest relative abundance of Mycobacterium spp. Data were examined across utilities to identify a true universal core, special core, and peripheral organisms to deepen insight into the physical and chemical factors that shape the building plumbing microbiome. PMID:26495985

  10. Ozone in sea water. Part 1: Chemistry; Part 2: Corrosion of metals

    SciTech Connect

    Wyllie, W.E. II; Brown, B.E.; Duquette, D.J.

    1995-12-01

    Ozonation of sea water for biofouling control is being utilized in desalination processes, heat exchange systems, as well as in salt water aquariums. The chemistry of ozone in sea water is much more complex than in fresh water due to the high concentration of easily oxidizable, ozone-demanding species and the formation of secondary oxidants. The major secondary oxidant is bromine in the form of hypobromite and hypobromous acid (BrO{sup {minus}}/HOBr) which are formed by oxidation of the bromide ion (Br{sup {minus}}), naturally found in sea water in concentrations of 65 mg/L. HOBr can react again with ozone to return Br{sup {minus}}, resulting in accelerated decomposition of ozone, or to form bromate (BrO{sub 3}{sup {minus}}) The BrO ion is known to interfere with the measurement of residual ozone in sea water, so it is important that the feed gas conditions, solution pH, and the hypobromous and bromate concentrations be reported to quantify the amount of ozone introduced into a system. In 0.5 N NaCl and sea water solutions, ozone appears to stabilize the passivity of passivating metals, but susceptibility to crevice corrosion appears to increase in the same environments. The effect of BrO{sup {minus}}/HOBr on the corrosion of metals in sea water is believed to be similar to chlorine and ozone, in that it acts as a strong oxidizer. However, it is not certain whether BrO{sup {minus}}/HOBr and BrO{sub 3}{sup {minus}} have any damaging effects on protective metal films.