WorldWideScience

Sample records for seawater

  1. Materials resistant to seawater

    International Nuclear Information System (INIS)

    Lunde, L.

    1986-03-01

    The report is a summary of the topics discussed at a two-day seminar at Institute for Energy Technology, Kjeller in August 1985. Experience with seawater corrosion in Nordic power reactor plants was discussed. There was also input from Danish experience with seawater corrosion in coal fired power plants. The following topics were dealt with: Experience in seawater cooling system materials, chlorination of seawater systems, and accelerated laboratory tests for stainless steels

  2. Seawater predesalination with electrodialysis

    NARCIS (Netherlands)

    Galama, A.H.; Saakes, M.; Bruning, H.; Rijnaarts, H.H.M.; Post, J.W.

    2014-01-01

    The suitability of ED for seawater desalination was investigated and we quantified the energy losses that play a role in electrodialysis. The combination of electrodialysis (ED) and brackish water reverse osmosis (BWRO) is presented as an alternative desalination strategy for seawater reverse

  3. Impact of seawater [Ca

    NARCIS (Netherlands)

    Mewes, A.; Langer, G.; Thoms, S.; Nehrke, G.; Reichart, G.J.; de Nooijer, L.J.; Bijma, J.

    2015-01-01

    Mg / Ca ratios in foraminiferal tests are routinely used as paleotemperature proxies, but on long timescales, they also hold the potential to reconstruct past seawater Mg / Ca. The impact of both temperature and seawater Mg / Ca on Mg incorporation in Foraminifera has been quantified by a number of

  4. Nature/culture/seawater.

    Science.gov (United States)

    Helmreich, Stefan

    2011-01-01

    Seawater has occupied an ambiguous place in anthropological categories of "nature" and "culture." Seawater as nature appears as potentiality of form and uncontainable flux; it moves faster than culture - with culture frequently figured through land-based metaphors - even as culture seeks to channel water's (nature's) flow. Seawater as culture manifests as a medium of pleasure, sustenance, travel, disaster. I argue that, although seawater's qualities in early anthropology were portrayed impressionistically, today technical, scientific descriptions of water's form prevail. For example, processes of globalization - which may also be called "oceanization" - are often described as "currents," "flows," and "circulations." Examining sea-set ethnography, maritime anthropologies, and contemporary social theory, I propose that seawater has operated as a “theory machine” for generating insights about human cultural organization. I develop this argument with ethnography from the Sargasso Sea and in the Sea Islands. I conclude with a critique of appeals to water's form in social theory.

  5. Butterfly valves for seawater

    International Nuclear Information System (INIS)

    Yamanaka, Katsuto

    1991-01-01

    Recently in thermal and nuclear power stations and chemical plants which have become large capacity, large quantity of cooling water is required, and mostly seawater is utilized. In these cooling water systems, considering thermal efficiency and economy, the pipings become complex, and various control functions are demanded. For the purpose, the installation of shut-off valves and control valves for pipings is necessary. The various types of valves have been employed, and in particular, butterfly valves have many merits in their function, size, structure, operation, maintenance, usable period, price and so on. The corrosion behavior of seawater is complicated due to the pollution of seawater, therefore, the environment of the valves used for seawater became severe. The structure and the features of the butterfly valves for seawater, the change of the structure of the butterfly valves for seawater and the checkup of the butterfly valves for seawater are reported. The corrosion of metallic materials is complicatedly different due to the locating condition of plants, the state of pipings and the condition of use. The corrosion countermeasures for butterfly valves must be examined from the synthetic viewpoints. (K.I.)

  6. SRB seawater corrosion project

    Science.gov (United States)

    Bozack, M. J.

    1991-01-01

    The corrosion behavior of 2219 aluminum when exposed to seawater was characterized. Controlled corrosion experiments at three different temperatures (30, 60 and 100 C) and two different environments (seawater and 3.5 percent salt solution) were designed to elucidate the initial stages in the corrosion process. It was found that 2219 aluminum is an active catalytic surface for growth of Al2O3, NaCl, and MgO. Formation of Al2O3 is favored at lower temperatures, while MgO is favored at higher temperatures. Visible corrosion products are formed within 30 minutes after seawater exposure. Corrosion characteristics in 3.5 percent salt solution are different than corrosion in seawater. Techniques utilized were: (1) scanning electron microscopy, (2) energy dispersive x-ray spectroscopy, and (3) Auger electron spectroscopy.

  7. Uranium from seawater

    International Nuclear Information System (INIS)

    Gregg, D.; Folkendt, M.

    1982-01-01

    A novel process for recovering uranium from seawater is proposed and some of the critical technical parameters are evaluated. The process, in summary, consists of two different options for contacting adsorbant pellets with seawater without pumping the seawater. It is expected that this will reduce the mass handling requirements, compared to pumped seawater systems, by a factor of approximately 10 5 , which should also result in a large reduction in initial capital investment. Activated carbon, possibly in combination with a small amount of dissolved titanium hydroxide, is expected to be the preferred adsorbant material instead of the commonly assumed titanium hydroxide alone. The activated carbon, after exposure to seawater, can be stripped of uranium with an appropriate eluant (probably an acid) or can be burned for its heating value (possible in a power plant) leaving the uranium further enriched in its ash. The uranium, representing about 1% of the ash, is then a rich ore and would be recovered in a conventional manner. Experimental results have indicated that activated carbon, acting alone, is not adequately effective in adsorbing the uranium from seawater. We measured partition coefficients (concentration ratios) of approximately 10 3 in seawater instead of the reported values of 10 5 . However, preliminary tests carried out in fresh water show considerable promise for an extraction system that uses a combination of dissolved titanium hydroxide (in minute amounts) which forms an insoluble compound with the uranyl ion, and the insoluble compound then being sorbed out on activated carbon. Such a system showed partition coefficients in excess of 10 5 in fresh water. However, the system was not tested in seawater

  8. Chlorine-36 in seawater

    International Nuclear Information System (INIS)

    Argento, David C.; Stone, John O.; Keith Fifield, L.; Tims, Stephen G.

    2010-01-01

    Natural cosmogenic 36 Cl found in seawater originates from spallation of atmospheric 40 Ar, capture of secondary cosmic-ray neutrons by dissolved 35 Cl, and river runoff which contains 36 Cl produced in situ over the surface of the continents. The long residence time of chloride in the ocean and long half-life of 36 Cl compared to the oceanic mixing time should result in a homogenous 36 Cl/Cl ratio throughout the ocean. Production by neutron capture in the course of nuclear weapons testing should be insignificant averaged over the oceans as a whole, but may have led to regions of elevated 36 Cl concentration. Previous attempts to measure the 36 Cl/Cl ratio of seawater have been hindered by interferences, contamination, or insufficient analytic sensitivity. Here we report preliminary measurements on seawater samples, which demonstrate that the 36 Cl/Cl ratio is 0.5 ± 0.3 x 10 -15 , in reasonable agreement with calculated contributions from the sources listed above.

  9. Uranium from seawater

    International Nuclear Information System (INIS)

    1974-12-01

    The report concerns the possibilities of extracting uranium from seawater using either 'tidal' and 'pumped' schemes. It was decided to undertake an initial exercise on the pumped scheme. It was to take into account not only the direct energy requirements, but also the indirect energy inputs needed to produce the capital equipment, operating materials, etc. The report begins with a discussion of the technique of energy accounting, and the merits and limitations of the two principal approaches are compared. These are: 'Process Analysis' (or 'Energy Cost of Materials') and 'Input-Output Analysis' (or 'Energy Cost of Money'). A comparison is made between the energy cost of the tidal and pumped schemes, by both methods of analysis. A 'Best Estimate' is compiled calling on both methods, and this indicates that on an energy cost basis the pumped scheme is three times as expensive as the tidal scheme. Intermediate schemes are feasible, however. There is some evidence that the energy cost of an ore refining process with an initial concentration of 0.007% would be of the same order as that of the pumped seawater scheme. The energy cost of generating electricity using seawater uranium in an SGHWR is compared with the present UK generating system as a whole. (U.K.)

  10. Perchlorate in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Martinelango, P. Kalyani [Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409-1061 (United States); Tian Kang [Institute of Environmental and Human Health, Texas Tech University, Lubbock, TX 79409 (United States); Dasgupta, Purnendu K. [Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409-1061 (United States)]. E-mail: Sandyd@ttu.edu

    2006-05-10

    There has been no reliable published data on the presence of perchlorate in seawater. Seaweeds are among the most important plant life in the ocean and are good sources of iodine and have been widely used as food and nutritional supplement. Perchlorate is known to inhibit the transport of iodide by the sodium iodide symporter (NIS), present e.g., in the thyroid and mammary glands. With perchlorate being increasingly detected in drinking water, milk and various other foods, increasing the iodide intake through inexpensive natural supplements may be an attractive solution for maintaining iodine assimilation. We report here measurable concentrations of perchlorate in several samples of seawater (detectable in about half the samples analyzed). We also report the iodide and perchlorate concentrations of 11 different species of seaweed and the corresponding bioconcentration factors (BCF) for perchlorate and iodide, relative to the seawater from which they were harvested. All seaweed samples came from the same region, off the coast of Northeastern Maine. Concentrations of iodide and perchlorate in four seawater samples collected from the region near harvest time were 30 {+-} 11 and 0.16 {+-} 0.084 {mu}g l{sup -1}, respectively. Concentrations of both iodide and perchlorate varied over a wide range for different seaweed species; iodide ranging from 16 to 3134 mg kg{sup -1} and perchlorate from 0.077 to 3.2 mg kg{sup -1}. The Laminaria species had the highest iodide concentration; Laminaria digitata is the seaweed species most commonly used in the kelp tablets sold in health food stores. Our sample of L. digitata contained 3134 {+-} 15 mg iodide/kg dry weight. The BCF varied widely for different species, with Laminaria species concentrating iodide preferentially over perchlorate. The iodide BCF (BCF{sub i}) to perchlorate BCF (BCF{sub p}) quotient ranged from 0.66 to 53; L. digitata and L. saccarina having a BCF{sub i}/BCF{sub p} value of 45 and 53, respectively, far

  11. Seawater and marine sidements

    International Nuclear Information System (INIS)

    Eicke, H.F.

    1985-01-01

    The Deutsches Hydrographisches Institut (DHI) is responsible for monitoring the radioactive substances (such as Cs-137, Cs-134, Sr-90, H-3, Pu-239, Pu-240) in the seawater and marine sediments along the Federal German seacoasts, of the fishing grounds of the Federal German offshore fishery industry, and of marine currents moving towards these fishing grounds. The DHI has been carrying out this task since 1965, activities being placed under the responsibility of the DHI Department for Marine Radioactivity, which since 1960 is a directing centre within the Government's system for environmental radioactivity monitoring. (orig./DG) [de

  12. Perchlorate in seawater

    International Nuclear Information System (INIS)

    Martinelango, P. Kalyani; Tian Kang; Dasgupta, Purnendu K.

    2006-01-01

    There has been no reliable published data on the presence of perchlorate in seawater. Seaweeds are among the most important plant life in the ocean and are good sources of iodine and have been widely used as food and nutritional supplement. Perchlorate is known to inhibit the transport of iodide by the sodium iodide symporter (NIS), present e.g., in the thyroid and mammary glands. With perchlorate being increasingly detected in drinking water, milk and various other foods, increasing the iodide intake through inexpensive natural supplements may be an attractive solution for maintaining iodine assimilation. We report here measurable concentrations of perchlorate in several samples of seawater (detectable in about half the samples analyzed). We also report the iodide and perchlorate concentrations of 11 different species of seaweed and the corresponding bioconcentration factors (BCF) for perchlorate and iodide, relative to the seawater from which they were harvested. All seaweed samples came from the same region, off the coast of Northeastern Maine. Concentrations of iodide and perchlorate in four seawater samples collected from the region near harvest time were 30 ± 11 and 0.16 ± 0.084 μg l -1 , respectively. Concentrations of both iodide and perchlorate varied over a wide range for different seaweed species; iodide ranging from 16 to 3134 mg kg -1 and perchlorate from 0.077 to 3.2 mg kg -1 . The Laminaria species had the highest iodide concentration; Laminaria digitata is the seaweed species most commonly used in the kelp tablets sold in health food stores. Our sample of L. digitata contained 3134 ± 15 mg iodide/kg dry weight. The BCF varied widely for different species, with Laminaria species concentrating iodide preferentially over perchlorate. The iodide BCF (BCF i ) to perchlorate BCF (BCF p ) quotient ranged from 0.66 to 53; L. digitata and L. saccarina having a BCF i /BCF p value of 45 and 53, respectively, far greater than a simple anion exchange process

  13. Corrosion in seawater systems

    International Nuclear Information System (INIS)

    Henrikson, S.

    1988-01-01

    Highly alloyed stainless steels have been exposed to natural chlorinated and chlorine-free seawater at 35 deg. C. Simulated tube-tubesheet joints, weld joints and galvanic couples with titanium, 90/10 CuNi and NiAl bronze were tested and evaluated for corrosion. The corrosion rates of various anode materials - zinc, aluminium and soft iron - were also determined. Finally the risk of hydrogen embrittlement of tubes of ferritic stainless steels and titanium as a consequence of cathodic protection was studied. An attempt was also made to explain the cracking mechanism of the ferritic steels by means of transmission electron microscopy. One important conclusion of the project is that chlorinated seawater is considerably more corrosive to stainless steels than chlorine-free water, whereas chlorination reduces the rate of galvanic corrosion of copper materials coupled to stainless steels. Hydrogen embrittlement of ferritic stainless steels and titanium as a consequence of cathodic protection of carbon steel or cast iron in the same structure can be avoided by strict potentiostatic control of the applied potential. (author)

  14. Effect of different seawater Mg

    NARCIS (Netherlands)

    Mewes, A.; Langer, G.; de Nooijer, L.J.; Bijma, J.; Reichart, G.J.

    2014-01-01

    Magnesium, incorporated in foraminiferal calcite (Mg/CaCC), is used intensively to reconstruct past seawater temperatures but, in addition to temperature, the Mg/CaCC of foraminiferal tests also depends on the ratio of Mg and Ca in seawater (Mg/CaSW). The physiological mechanisms responsible for

  15. Fuel Production from Seawater and Fuel Cells Using Seawater.

    Science.gov (United States)

    Fukuzumi, Shunichi; Lee, Yong-Min; Nam, Wonwoo

    2017-11-23

    Seawater is the most abundant resource on our planet and fuel production from seawater has the notable advantage that it would not compete with growing demands for pure water. This Review focuses on the production of fuels from seawater and their direct use in fuel cells. Electrolysis of seawater under appropriate conditions affords hydrogen and dioxygen with 100 % faradaic efficiency without oxidation of chloride. Photoelectrocatalytic production of hydrogen from seawater provides a promising way to produce hydrogen with low cost and high efficiency. Microbial solar cells (MSCs) that use biofilms produced in seawater can generate electricity from sunlight without additional fuel because the products of photosynthesis can be utilized as electrode reactants, whereas the electrode products can be utilized as photosynthetic reactants. Another important source for hydrogen is hydrogen sulfide, which is abundantly found in Black Sea deep water. Hydrogen produced by electrolysis of Black Sea deep water can also be used in hydrogen fuel cells. Production of a fuel and its direct use in a fuel cell has been made possible for the first time by a combination of photocatalytic production of hydrogen peroxide from seawater and dioxygen in the air and its direct use in one-compartment hydrogen peroxide fuel cells to obtain electric power. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Uranium extraction from seawater

    International Nuclear Information System (INIS)

    Bals, H.G.

    1976-03-01

    After an introduction to the physics and chemistry of the sea and an estimation of the chances for the absorption of uranium from rivers, the material-sepecific characteristics of the adsorber technology are decribed in detail. Then, the methods used for gaining uranium form seawater are described with special regard to the tidal and the so-called serial (sequency) method. Whether all methods described can be realised is an economic problem since very high quantitics of water are necessary because of the low contents of uranium. A positive energy balance (gained energy/lost energy) is not definitely ensured yet for the production methods used. The development measures to be taken to obtain a positive energy balance are briefly described, and the research programme of the UEBG is mentioned. (UA) [de

  17. Uranium recovery from seawater

    International Nuclear Information System (INIS)

    Bitte, J.; Fremery, M.I.; Kellner, A.; Schroeer, K.; Knippenberg, W.

    1984-09-01

    The present publication describes the development work of a process to recover uranium from seawater and the proposition of a commercial demonstration plant. The essential components of this process are verified in the laboratory scale as well as in some field tests. A detailed engineering design for a model plant in a semi-technical scale to allow field tests in the marine environment is also presented. These field tests are expected to produce more realistic data on the technical and economical feasibility of the proposed technology. Production cost estimates based on state-of-the-art technology lie around 250 Dollar/1b U 3 O 8 . However, the effect of a corresponding uranium price increase on electricity costs are comparable to cost increases in coal operated power plants caused by the desulfurisation of coal. Further reductions of the production costs in the range below 150 Dollar/1b U 3 O 8 seem possible through special research efforts in the area of sorber development and concept design. (orig.) [de

  18. Neodymium isotopic variations in seawater

    International Nuclear Information System (INIS)

    Piepgras, D.J.; Wasserburg, G.J.

    1980-01-01

    New data for the direct measurement of the isotopic composition of neodymium in Atlantic Ocean seawater are compared with previous measurements of Pacific Ocean seawater and ferromanganese sediments from major ocean basins. Data for Atlantic seawater are in excellent agreement with Nd isotopic measurements made on Atlantic ferromanganese sediments and are distinctly different from the observed compositions of Pacific samples. These results clearly demonstrate the existence of distinctive differences in the isotopic composition of Nd in the waters of the major ocean basins and are characteristic of the ocean basin sampled. The average epsilonsub(N)sub(d)(0) values for the major oceans as determined by data from seawater and ferromanganese sediments are as follows: Atlantic Ocean, epsilonsub(N)sub(d)(0) approx. equal to - 12 +- 2; Indian Ocean, epsilonsub(N)sub(d)(0) approx. equal to - 8 +- 2; Pacific Ocean, epsilonsub(N)sub(d)(0) approx. equal to -3 +- 2. These values are considerably less than epsilonsub(N)sub(d)(0) value sources with oceanic mantle affinities indicating that the REE in the oceans are dominated by continental sources. The difference in the absolute abundance of 143 Nd between the Pacific and Atlantic Oceans corresponds to approx. 10 6 atoms 143 Nd per gram of seawater. The correspondence between the 143 Nd/ 144 Nd in seawater and in the associated sediments suggests the possible application of this approach to paleo-oceanography. (orig./HAE)

  19. Recovery of uranium from seawater

    International Nuclear Information System (INIS)

    Hirotsu, Takahiro; Takagi, Norio; Katoh, Shunsaku

    1995-01-01

    Present status of the development of chelating adsorbents for the recovery of uranium from seawater is outlined with emphasis on the research by the author. Uranium is estimated to exist as stable tri (carbonate) uranylate (6) ion in seawater in a very low concentration. The adsorbent for uranium from seawater in a very low concentration. The adsorbent for uranium from seawater should have high selectivity and affinity for uranium around pH 8. The required characteristics for uranium adsorbent are examined. Various chelating adsorbents have been proposed for the uranium adsorbent and their structures are discussed. Amidoxime type adsorbents have the highest adsorbing power for uranium among the adsorbents hitherto developed and fibrous amidoxime adsorbents are most promising for the practical application. Synthesis, structure and suitable shape of the amidoxime adsorbents are discussed. Uranium adsorption behavior and the amount of saturated adsorption are examined theoretically based on the complexation of an amidoxime monomer and the formula for the adsorption equiliburium is derived. The adsorption and recovery process for uranium from seawater is composed of adsorption, desorption, separation and concentration and finally, uranium is recovered as the yellow cake. A floating body mooring system is proposed by Nobukawa. (T.H.)

  20. Seawater desalination with nuclear power

    International Nuclear Information System (INIS)

    2005-01-01

    Nuclear power helps reduce costs for energy-intensive processes such as seawater desalination. A new generation of innovative small and medium nuclear power plants could co-generate electricity and potable water from seawater, both safely and at competitive prices in today's market. The IAEA provides technical support to Member States facing water shortage problems, on assessing the viability of nuclear power in seawater desalination. The support, usually channelled through national Technical Cooperation (TC) projects, can take several forms, ranging from educational training and technical advice on feasibility studies to design and safety review of demonstration projects. The IAEA offers a software tool (DEEP) that can be used to evaluate the economics of the different desalination and heat source configurations, including nuclear and fossil options

  1. Paleogene Seawater Osmium Isotope Records

    Science.gov (United States)

    Rolewicz, Z.; Thomas, D. J.; Marcantonio, F.

    2012-12-01

    Paleoceanographic reconstructions of the Late Cretaceous and early Cenozoic require enhanced geographic coverage, particularly in the Pacific, in order to better constrain meridional variations in environmental conditions. The challenge with the existing inventory of Pacific deep-sea cores is that they consist almost exclusively of pelagic clay with little existing age control. Pelagic clay sequences are useful for reconstructions of dust accumulation and water mass composition, but accurate correlation of these records to other sites requires improved age control. Recent work indicates that seawater Os isotope analyses provide useful age control for red clay sequences. The residence time of Os in seawater is relatively long compared to oceanic mixing, therefore the global seawater 187Os/188Os composition is practically homogeneous. A growing body of Late Cretaceous and Cenozoic data has constrained the evolution of the seawater Os isotopic composition and this curve is now a viable stratigraphic tool, employed in dating layers of Fe-Mn crusts (e.g., Klemm et al., 2005). Ravizza (2007) also demonstrated that the seawater Os isotopic composition can be extracted reliably from pelagic red clay sediments by analyzing the leached oxide minerals. The drawback to using seawater Os isotope stratigraphy to date Paleogene age sediments is that the compilation of existing data has some significant temporal gaps, notably between ~38 and 55 Ma. To improve the temporal resolution of the seawater Os isotope curve, we present new data from Ocean Drilling Program (ODP) Site 865 in the equatorial Pacific. Site 865 has excellent biostratigraphic age control over the interval ~38-55Ma. Preliminary data indicate an increase in the seawater composition from 0.427 at 53.4 Ma to 0.499 by 43 Ma, consistent with the apparent trend in the few existing data points. We also analyzed the Os isotopic composition recorded by oxide minerals at Integrated Ocean Drilling Program (IODP) Site U1370

  2. Neodymium isotopic variations in seawater

    Science.gov (United States)

    Piepgras, D. J.; Wasserburg, G. J.

    1980-01-01

    Direct measurement of the isotopic composition of Nd in the Atlantic agree with the Nd content in ferromanganese sediments and differ from the observed amounts in the Pacific samples. These data indicate the existence of distinctive differences in the isotopic composition of Nd in the waters of major oceans; the average values determined from seawater and ferromanganese sediments are considerably lower than in sources with oceanic mantle affinities showing that the REE in the oceans is dominated by continental sources. The Nd isotopic variations in seawater are applied to relate the residence time of Nd and mixing rates between the oceans.

  3. Faraday's Law and Seawater Motion

    Science.gov (United States)

    De Luca, R.

    2010-01-01

    Using Faraday's law, one can illustrate how an electromotive force generator, directly utilizing seawater motion, works. The conceptual device proposed is rather simple in its components and can be built in any high school or college laboratory. The description of the way in which the device generates an electromotive force can be instructive not…

  4. Rapid determination of 90Sr in seawater

    International Nuclear Information System (INIS)

    Pavlotskaya, F.I.; Moskin, A.I.

    1994-01-01

    A method for determining 90 Sr in seawater that is based on direct isolation and radiochemical purification of daughter 90 Y is proposed. The analysis time is 6-8 h. The chemical yield of the Y-carrier during the 90 Sr determination from 35 liters of seawater varies in the range 37-69%. The analysis uncertainty is 90 Sr from seawater and subsequent isolation of 90 Y

  5. Sorption isolation of strontium from seawater

    International Nuclear Information System (INIS)

    Avramenko, V.A.; Zheleznov, V.V.; Kaplun, E.V.; Sokol'nitskaya, T.A.; Yukhkam, A.A.

    2001-01-01

    Sorption isolation of strontium from seawater is considered and prospects of use of selective adsorbents for purification of seawater or liquid radioactive wastes mixed with seawater from 90 Sr are discussed. Comparative analysis of sorptive properties of adsorbents of different nature is done. It is shown that sorption-reagent materials developed by authors can to afford effective separation of 90 Sr from seawater. Possible mechanism of strontium sorption by these adsorbents is considered. The prospect of their use for purification of liquid radioactive wastes from strontium is shown [ru

  6. Recovery of lithium from seawater

    International Nuclear Information System (INIS)

    Ooi, Kenta; Miyai, Yoshitaka; Katoh, Shunsaku; Abe, Mitsuo.

    1989-01-01

    Lithium has been used for air conditioners, aluminum refining, ceramics, organic metal compounds, batteries and many other uses. Besides, attention is paid as the aluminum-lithium alloys as aircraft materials, and the raw materials for large capacity batteries and nuclear fusion reactors for the future. The amount of lithium resources has been estimated as 14 million tons, and is relatively abundant, but when the future increase of demand is considered, it is not necessarily sufficient. Japan lacks lithium resources, and the stable ensuring of the resources has become an important problem. Seawater contains lithium by 170 μg/l, and its total amount reaches 230 billion tons. The process of recovering lithium from seawater, geothermal water and natural gas brine has been actively researched since 10 years ago centering around Japan. At present, the search for the adsorbent that effectively collects lithium is the main subject. Also the recovery by coprecipitation has been investigated basically. The inorganic adsorbent for lithium is classified into aluminum type, compound antimonic acid type, layered compound type, ion sieve oxide type and others. Their lithium adsorption performance and adsorption mechanism are different remarkably, therefore, these of each group are described. (K.I.) 70 refs

  7. Past seawater experience enhances seawater adaptability in medaka, Oryzias latipes.

    Science.gov (United States)

    Miyanishi, Hiroshi; Inokuchi, Mayu; Nobata, Shigenori; Kaneko, Toyoji

    2016-01-01

    During the course of evolution, fishes have acquired adaptability to various salinity environments, and acquirement of seawater (SW) adaptability has played important roles in fish evolution and diversity. However, little is known about how saline environments influence the acquirement of SW adaptability. The Japanese medaka Oryzias latipes is a euryhaline species that usually inhabits freshwater (FW), but is also adaptable to full-strength SW when transferred through diluted SW. In the present study, we examined how past SW experience affects hyposmoregulatory ability in Japanese medaka. For the preparation of SW-experienced fish, FW medaka were acclimated to SW after pre-acclimation to 1/2 SW, and the SW-acclimated fish were transferred back to FW. The SW-experienced fish and control FW fish (SW-inexperienced fish) were transferred directly to SW. Whereas control FW fish did not survive direct transfer to SW, 1/4 of SW-experienced fish adapted successfully to SW. Although there were no significant differences in blood osmolality and plasma Na(+) and Cl(-) concentrations between SW-experienced and control FW medaka in FW, increments in these parameters following SW transfer were lower in SW-experienced fish than in control FW fish. The gene expression of SW-type Na(+), K(+)-ATPase (NKA) in the gills of SW-experienced medaka increased more quickly after direct SW transfer compared with the expression in control FW fish. Prior to SW transfer, the density of NKA-immunoreactive ionocytes in the gills was higher in SW-experienced fish than in control FW fish. Ionocytes expressing CFTR Cl(-) channel at the apical membrane and those forming multicellular complexes, both of which were characteristic of SW-type ionocytes, were also increased in SW-experienced fish. These results indicate that past SW experience enhances the capacity of Na(+) and Cl(-) secretion in ionocytes and thus hypoosmoregulatory ability of Japanese medaka, suggesting the presence of epigenetic

  8. Primary biodegradation of petroleum hydrocarbons in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Comber, M.I.H.; Den Haan, K.H.; Djemel, N.; Eadsforth, C.V.; King, D.; Paumen, M.L.; Parkerton, T.; Dmytrasz, B.

    2012-12-15

    This report describes primary biodegradation experiments performed to determine the persistence of higher molecular weight petroleum hydrocarbons in seawater. Results from the biodegradation experiments show that the majority of tested petroleum hydrocarbons have half-lives in seawater less than 60 days.

  9. Chemical effect on ozone deposition over seawater

    Science.gov (United States)

    Surface layer resistance plays an important role in determining ozone deposition velocity over seawater. Recent studies suggest that surface layer resistance over sea-water is influenced by wind-speed and chemical interaction at the air-water interface. Here, we investigate the e...

  10. Rapid determination of actinides in seawater samples

    International Nuclear Information System (INIS)

    Maxwell, S.L.; Culligan, B.K.; Hutchison, J.B.; Utsey, R.C.; McAlister, D.R.

    2014-01-01

    A new rapid method for the determination of actinides in seawater samples has been developed at the Savannah River National Laboratory. The actinides can be measured by alpha spectrometry or inductively-coupled plasma mass spectrometry. The new method employs novel pre-concentration steps to collect the actinide isotopes quickly from 80 L or more of seawater. Actinides are co-precipitated using an iron hydroxide co-precipitation step enhanced with Ti +3 reductant, followed by lanthanum fluoride co-precipitation. Stacked TEVA Resin and TRU Resin cartridges are used to rapidly separate Pu, U, and Np isotopes from seawater samples. TEVA Resin and DGA Resin were used to separate and measure Pu, Am and Cm isotopes in seawater volumes up to 80 L. This robust method is ideal for emergency seawater samples following a radiological incident. It can also be used, however, for the routine analysis of seawater samples for oceanographic studies to enhance efficiency and productivity. In contrast, many current methods to determine actinides in seawater can take 1-2 weeks and provide chemical yields of ∼30-60 %. This new sample preparation method can be performed in 4-8 h with tracer yields of ∼85-95 %. By employing a rapid, robust sample preparation method with high chemical yields, less seawater is needed to achieve lower or comparable detection limits for actinide isotopes with less time and effort. (author)

  11. Colloidal nature of radionuclides in seawater

    International Nuclear Information System (INIS)

    Feldman, I.

    1976-01-01

    There is considerable doubt that equilibrium calculations, i.e., employing solubility products and complex-ion stability constants, are valid for the submicro concentrations of radionuclides in seawater. The existence of radiocolloids should be expected in seawater. The great tendency of radiocolloids to adsorb onto finely-divided hydrous oxides makes their formation of significance in seawater, especially for artificial radionuclides. The subject of radiocolloid formation is reviewed in this chapter. It is shown that the 226 Ra/ 230 Th/U relationship found in seawater can be explained from the fact that the tendencies of these elements to form radiocolloids in seawater should decrease in order thorium > radium much greater than uranium. This explanation is much simpler than the prevailing oceanographic one. The theories for radiocolloid formation are discussed. The recent theory of Jones and Healy for the adsorption of hydrolyzable metal ions onto hydrous oxides is reviewed briefly, and its relevance to radiocolloid formation is pointed out

  12. Development of radioactive seawater monitors, 1

    International Nuclear Information System (INIS)

    Fukushima, Masanori

    1989-01-01

    Applicability of some adsorptive materials to monitoring of radioactive seawater is generalized. Studied techniques that allow utilization of adsorptive materials in monitoring radioactive seawater are the substitute methods using sampled seawater or indicator plants such as gulfweed and the method using adsorptive materials for continuous monitoring of underwater radioactivity, the method using them for field measurement of under water radioactivity from a boat, and the method using an adsorptive material moored underwater for integration monitoring of underwater radioactivity. Selected adsorptive materials that were judged suitable for monitoring radioactive seawater is the one composed of some kind of adsorptive compound (manganese dioxide or ferrocyan cobalt potassium) fixed to crylic cellulose. This adsorptive material permits selective scavenging radioactive Cs, Mn, Co, Zn, Ce, Fe, Ru, Ra Th, Pu and Am from seawater. (aurhor)

  13. Automated nutrient analyses in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Whitledge, T.E.; Malloy, S.C.; Patton, C.J.; Wirick, C.D.

    1981-02-01

    This manual was assembled for use as a guide for analyzing the nutrient content of seawater samples collected in the marine coastal zone of the Northeast United States and the Bering Sea. Some modifications (changes in dilution or sample pump tube sizes) may be necessary to achieve optimum measurements in very pronounced oligotrophic, eutrophic or brackish areas. Information is presented under the following section headings: theory and mechanics of automated analysis; continuous flow system description; operation of autoanalyzer system; cookbook of current nutrient methods; automated analyzer and data analysis software; computer interfacing and hardware modifications; and trouble shooting. The three appendixes are entitled: references and additional reading; manifold components and chemicals; and software listings. (JGB)

  14. Present status of uranium extraction from seawater

    International Nuclear Information System (INIS)

    Kusakabe, Katsuki; Morooka, Shigeharu

    1993-01-01

    For the research on the extraction of uranium from seawater, various processes have been examined, but the most promising process is adsorption. Its key point is the performance of the adsorbent. The system as compact as possible, in which a large quantity of seawater effectively contacts with the adsorbent, must be constructed economically. As the inorganic adsorbent, titanium oxide is the best, but organic amidoxime is superior to it. The present state of the development of the adsorbent, the rate of adsorption of the adsorbenbt, the seawater uranium adsorption system and the experiment in Imari Bay are reported. (K.I.)

  15. The Geologic History of Seawater

    Science.gov (United States)

    Holland, H. D.

    2003-12-01

    Aristotle proposed that the saltness of the sea was due to the effect of sunlight on water. Robert Boyle took strong exception to this view and - in the manner of the Royal Society - laid out a program of research in the opening paragraph of his Observations and Experiments about the Saltness of the Sea (1674) (Figure 1): (20K)Figure 1. Title page of Robert Boyle's Tracts consisting of Observations about the Saltness of the Sea and other essays (1674). The Cause of the Saltness of the Sea appears by Aristotle's Writings to have busied the Curiosity of Naturalists before his time; since which, his Authority, perhaps much more than his Reasons, did for divers Ages make the Schools and the generality of Naturalists of his Opinion, till towards the end of the last Century, and the beginning of ours, some Learned Men took the boldness to question the common Opinion; since when the Controversie has been kept on foot, and, for ought I know, will be so, as long as ‘tis argued on both sides but by Dialectical Arguments, which may be probable on both sides, but are not convincing on either. Wherefore I shall here briefly deliver some particulars about the Saltness of the Sea, obtained by my own trials, where I was able; and where I was not, by the best Relations I could procure, especially from Navigators.Boyle measured and compiled a considerable set of data for variations in the saltness of surface seawater. He also designed an improved piece of equipment for sampling seawater at depth, but the depths at which it was used were modest: 30 m with his own instrument, 80 m with another, similar sampler. However, the younger John Winthrop (1606-1676), an early member of the Royal Society, an important Governor of Connecticut, and a benefactor of Harvard College, was asked to collect seawater from the bottom of the Atlantic Ocean during his crossing from England to New England in the spring of 1663. The minutes of the Royal Society's meeting on July 20, 1663, give the

  16. Seawater circulating system in an aquaculture laboratory

    Digital Repository Service at National Institute of Oceanography (India)

    Chatterji, A.; Ingole, B.S.; Parulekar, A.H.

    The note gives an account, for the first time in India, of an Aquaculture Laboratory with open type seawater circulating system developed at the National Institute of Oceanography, Goa, India. Besides describing the details of the system...

  17. Seawater Immersion of GEM II Propellant

    National Research Council Canada - National Science Library

    Merrill, Calude

    1999-01-01

    ... (% AP lost/week aged in seawater) and intercepts that depend on sample size. Friction and impact data on dried aged propellant samples showed no increased burning hazard compared with propellant not exposed to water...

  18. Uranium preconcentration from seawater using adsorptive membranes

    International Nuclear Information System (INIS)

    Das, Sadananda; Pandey, A.K.; Manchanda, V.K.; Athawale, A.A.

    2009-01-01

    Uranium recovery from bio-aggressive but lean feed like seawater is a challenging problem as it requires in situ preconcentration of uranium in presence of huge excess of competing ions with fast sorption kinetics. In our laboratory, widely used amidoxime membrane (AO-membrane) was evaluated for uranium sorption under seawater conditions. This study indicated that AO-membrane was inherently slow because of the complexation chemistry involved in transfer of U(VI) from (UO 2 (CO 3 ) 3 ) 4 - to AO sites in membrane. In order to search better options, several chemical compositions of membrane were scanned for their efficacy for uranium preconcentration from seawater, and concluded that EGMP-membrane offers several advantages over AO-membrane. In this paper, the comparison of EGMP-membrane with AO-membrane for uranium sorption under seawater conditions has been reviewed. (author)

  19. Behaviour of stainless steel in natural seawater

    OpenAIRE

    Compere, Chantal; Le Bozec, Nathalie

    1997-01-01

    In this paper, investigations performed in natural and artificial seawater on stainless steels will be presented. They concerned studies on: biofilm formation, passive layers composition, electrochemical behaviour, localised corrosion and the evolution of these different parameters as a function of ageing time. According to literature surveys, the different aspects will be discussed. Some conclusions will be drawn concerning the actual knowledge on the behaviour of stainless steels in seawater.

  20. Greening Drylands with Seawater Easily and Naturally.

    Science.gov (United States)

    Moustafa, Khaled

    2017-03-01

    The sun and sea are inexhaustible sources of energy and water that could be used to transform drylands into more viable ecosystems. A sustainable and cost-effective approach is proposed for greening drylands and restoring wildlife and biodiversity in deserts using seawater desert-houses (or movable seawater ponds) that could offer important environmental advantages. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Radiolytic removal of trihalomethane in chlorinated seawater

    International Nuclear Information System (INIS)

    Rajamohan, R.; Rajesh, Puspalata; Venugopalan, V.P.; Rangarajan, S.; Natesan, Usha

    2015-01-01

    Biofouling is one of the major operational problems in seawater cooling systems. It is controlled by application of chlorine based biocides in the range of 0.5-2.0 mg L -1 . The bromide in seawater reacts with the added chlorine and forms hypobromous acid. The brominated residual biocides react with natural organic matter present in the seawater, resulting in the formation of trihalomethanes (THM) such as bromoform (CHBr 3 ), dibromochloromethane (CHBr 2 Cl) bromodichloromethane (CHBrCl 2 ). Though THMs represent a small fraction of the added chlorine, they are relatively more persistent than residual chlorine, and hence pose a potential hazard to marine life because of their reported mutagenicity. There have been few reports on removal of THMs from chlorinated seawater. In this work, the efficacy of gamma irradiation technique for the removal of THMs from chlorine-dosed seawater was investigated. Experiments were carried out using seawater collected from Kalpakkam. Irradiation study was conducted in chlorinated (1, 3, and 5 mg L -1 of Cl 2 ) seawater by applying various dosages (0.4-5.0 kGy) of gamma radiation using a 60 Co Gamma Chamber 5000. Bromoform showed a faster rate of degradation as compared to other halocarbons like bromodichloromethane and dibromochloromethane. This shows the change in total THM concentration with variation in the radiation dose and initial Cl 2 dosing. When the percentage degradation of all the three trihalomethane species was compared with applied doses, it was found that the maximum reduction occurred at a dose of 2.5 kGy. The reduction was almost similar for all the three doses (1, 3, 5 ppm of Cl 2 ) used for chlorination. With a further increase in radiation dose to 5.0 kGy, a slight increase in reduction was observed

  2. [The effect of hypertonic seawater and isotonic seawater for nasal mucosa of allergic rhinitis mice model].

    Science.gov (United States)

    Deng, Zhifeng; Xu, Yu; Ou, Jin; Xiang, Rong; Tao, Zezhang

    2014-12-01

    To study the effect of hypertonic seawater and isotonic seawater for nasal mucosa of allergic rhinitis mice model, and explore the possible mechanism of nasal irrigation with seawater in treatment of allergic rhinitis. We used Der pl to make allergic rhinitis model of BALB/c mice, and divided them into three groups randomly. Nasal irrigation with hypertonic seawater (HS) or isotonic seawater (IS) in the treatment group 1-14 days after modeling, and black control (BC) group was given no treatment after modeling. Normal control (NC) group was given no treatment, the number of rubs and sneezings in each group were counted in 30 min after the last nasal irrigation. Mice were then killed 24 h after the last therapy. The noses of mice from each group were removed and fixed, then the slices were stained with hematoxylin and eosin, the others were observed by transmission electron microscope. Mice with hypertonic seawater and isotonic seawater were significantly improved in rubs and sneezings compared to the black control group (P 0. 05); Ciliated columnar epithelium cells in mucosal tissues of HS group and IS group were arranged trimly, better than that in the black control group. Morphology and microstructure in nasal mucosal of HS group was closer to the normal group than in IS group. The injury of nasal mucosa ciliated epithelium was significantly improved by nasal irrigation with hypertonic seawater and isotonic seawater, and the former is better than the latter, the mechanism of nasal irrigation with seawater in treatment of allergic rhinitis may rely on repairing the injured nasal mucosa ciliated epithelium, thereby the symptoms of nasal was reduced.

  3. Extracting Minerals from Seawater: An Energy Analysis

    Directory of Open Access Journals (Sweden)

    Ugo Bardi

    2010-04-01

    Full Text Available The concept of recovering minerals from seawater has been proposed as a way of counteracting the gradual depletion of conventional mineral ores. Seawater contains large amounts of dissolved ions and the four most concentrated metal ones (Na, Mg, Ca, K are being commercially extracted today. However, all the other metal ions exist at much lower concentrations. This paper reports an estimate of the feasibility of the extraction of these metal ions on the basis of the energy needed. In most cases, the result is that extraction in amounts comparable to the present production from land mines would be impossible because of the very large amount of energy needed. This conclusion holds also for uranium as fuel for the present generation of nuclear fission plants. Nevertheless, in a few cases, mainly lithium, extraction from seawater could provide amounts of metals sufficient for closing the cycle of metal use in the economy, provided that an increased level of recycling can be attained.

  4. Seawater bicarbonate removal during hydrothermal circulation

    Science.gov (United States)

    Proskurowski, G. K.; Seewald, J.; Sylva, S. P.; Reeves, E.; Lilley, M. D.

    2013-12-01

    High temperature fluids sampled at hydrothermal vents represent a complex alteration product of water-rock reactions on a multi-component mixture of source fluids. Sources to high-temperature hydrothermal samples include the 'original' seawater present in the recharge limb of circulation, magmatically influenced fluids added at depth as well as any seawater entrained during sampling. High-temperature hydrothermal fluids are typically enriched in magmatic volatiles, with CO2 the dominant species, characterized by concentrations of 10's-100's of mmol/kg (1, 2). Typically, the high concentration of CO2 relative to background seawater bicarbonate concentrations (~2.3 mmol/kg) obscures a full analysis of the fate of seawater bicarbonate during high-temperature hydrothermal circulation. Here we present data from a suite of samples collected over the past 15 years from high-temperature hydrothermal vents at 9N, Endeavour, Lau Basin, and the MAR that have endmember CO2 concentrations less than 10 mmol/kg. Using stable and radiocarbon isotope measurements these samples provide a unique opportunity to examine the balance between 'original' seawater bicarbonate and CO2 added from magmatic sources. Multiple lines of evidence from multiple hydrothermal settings consistently points to the removal of ~80% of the 'original' 2.3 mmol/kg seawater bicarbonate. Assuming that this removal occurs in the low-temperature, 'recharge' limb of hydrothermal circulation, this removal process is widely occurring and has important contributions to the global carbon cycle over geologic time. 1. Lilley MD, Butterfield DA, Lupton JE, & Olson EJ (2003) Magmatic events can produce rapid changes in hydrothermal vent chemistry. Nature 422(6934):878-881. 2. Seewald J, Cruse A, & Saccocia P (2003) Aqueous volatiles in hydrothermal fluids from the Main Endeavour Field, northern Juan de Fuca Ridge: temporal variability following earthquake activity. Earth and Planetary Science Letters 216(4):575-590.

  5. Nucleation from seawater emissions during mesocosm experiments

    Science.gov (United States)

    Rose, Clémence; Culot, Anais; Pey, Jorge; Schwier, Allison; Mas, Sébastien; Charriere, Bruno; Sempéré, Richard; Marchand, Nicolas; D'Anna, Barbara; Sellegri, Karine

    2015-04-01

    Nucleation and new particle formation in the marine atmosphere is usually associated to the presence of macroalgea emerged at low tides in coastal areas, while these processes were very rarely detected away from coastlines. In the present study, we evidence the formation of new particles from the 1 nm size above the seawater surface in the absence of any macroalgea population. Within the SAM project (Sources of marine Aerosol in the Mediterranean),seawater mesocosms experiments were deployed in May 2013 at the STARESO in western Corsica, with the goal of investigating the relationship between marine aerosol emissions and the seawater biogeochemical properties. Three mesocosms imprisoned 3,3 m3 of seawater each and their emerged part was flushed with aerosol-filtered natural air. One of these mesocosms was left unchanged as control and the two others were enriched by addition of nitrates and phosphates respecting Redfield ratio (N:P = 16) in order to create different levels of phytoplanctonic activities. We followed both water and air characteristics of three mesocosms during a period of three weeks by using online water and atmospheric probes as well as seawater daily samples for chemical and biological analysis. Secondary new particle formation was followed on-line in the emerged parts of the mesocosms, using a SMPS for the size distribution above 6 nm and a Particle Size Magnifyer (PSM) for the number of cluster particles between 1 and 6 nm. We will present how the cluster formation rates and early growth rates relate to the gaz-phase emissions from the seawater and to its biogeochemical properties. Aknowledgemnts: The authors want to acknowledge the financial support of the ANR "Source of marine Aerosol in the Mediterranean" (SAM), and the support of MISTRAL CHARMEX and MERMEX programs.

  6. The nuclear energy in the seawater desalination

    International Nuclear Information System (INIS)

    Moreno A, J.; Flores E, R.M.

    2004-01-01

    In general, the hydric resources of diverse regions of the world are insufficient for to satisfy the necessities of their inhabitants. Among the different technologies that are applied for the desalination of seawater are the distillation processes, the use of membranes and in particular recently in development the use of the nuclear energy (Nuclear Desalination; System to produce drinkable water starting from seawater in a complex integrated in that as much the nuclear reactor as the desalination system are in a common location, the facilities and pertinent services are shared, and the nuclear reactor produces the energy that is used for the desalination process). (Author)

  7. Biofouling control of industrial seawater cooling towers

    KAUST Repository

    Albloushi, Mohammed

    2017-11-01

    The use of seawater in cooling towers for industrial applications has much merit in the Gulf Cooperation Council countries due to the scarcity and availability of fresh water. Seawater make-up in cooling towers is deemed the most feasible because of its unlimited supply in coastal areas. Such latent-heat removal with seawater in cooling towers is several folds more efficient than sensible heat extraction via heat exchangers. Operational challenges such as scaling, corrosion, and biofouling are a major challenge in conventional cooling towers, where the latter is also a major issue in seawater cooling towers. Biofouling can significantly hamper the efficiency of cooling towers. The most popular methods used in cooling treatment to control biofouling are disinfection by chlorination. However, the disadvantages of chlorination are formation of harmful disinfection byproducts in the presence of high organic loading and safety concerns in the storage of chlorine gas. In this study, the research focuses on biofouling control in seawater cooling towers by investigating two different approaches. The first strategy addresses the use of alternative oxidants (i.e. ozone micro-bubbles and chlorine dioxide) in treatment of cooling towers. The second strategy investigates removing nutrients in seawater using granular activated carbon filter column and ultrafiltration to prevent the growth of microorganisms. Laboratory bench-scale tests in terms of temperature, cycle of concentration, dosage, etc. indicated that, at lower oxidant dosages (total residual oxidant (TRO) equivalent = 0.1 mg/l Cl2), chlorine dioxide had a better disinfection effect than chlorine and ozone. The performance of oxidizing biocides at pilot scale, operating at assorted conditions, showed that for the disinfectants tested, ozone could remove 95 % bioactivity of total number of bacteria and algae followed by chlorine dioxide at 85%, while conventional chlorine dosing only gave 60% reduction in bioactivities

  8. Impacts of seawater rise on seawater intrusion in the Nile Delta Aquifer, Egypt.

    Science.gov (United States)

    Sefelnasr, Ahmed; Sherif, Mohsen

    2014-01-01

    Several investigations have recently considered the possible impacts of climate change and seawater level rise on seawater intrusion in coastal aquifers. All have revealed the severity of the problem and the significance of the landward movement of the dispersion zone under the condition of seawater level rise. Most of the studies did not consider the possible effects of the seawater rise on the inland movement of the shoreline and the associate changes in the boundary conditions at the seaside and the domain geometry. Such effects become more evident in flat, low land, coastal alluvial plans where large areas might be submerged with seawater under a relatively small increase in the seawater level. None of the studies combined the effect of increased groundwater pumping, due to the possible decline in precipitation and shortage in surface water resources, with the expected landward shift of the shore line. In this article, the possible effects of seawater level rise in the Mediterranean Sea on the seawater intrusion problem in the Nile Delta Aquifer are investigated using FEFLOW. The simulations are conducted in horizontal view while considering the effect of the shoreline landward shift using digital elevation models. In addition to the basic run (current conditions), six different scenarios are considered. Scenarios one, two, and three assume a 0.5 m seawater rise while the total pumping is reduced by 50%, maintained as per the current conditions and doubled, respectively. Scenarios four, five, and six assume a 1.0 m seawater rise and the total pumping is changed as in the first three scenarios. The shoreline is moved to account for the seawater rise and hence the study domain and the seaside boundary are modified accordingly. It is concluded that, large areas in the coastal zone of the Nile Delta will be submerged by seawater and the coast line will shift landward by several kilometers in the eastern and western sides of the Delta. Scenario six represents

  9. Simulation of seawater intrusion in coastal aquifers: Some typical ...

    Indian Academy of Sciences (India)

    Springer Verlag Heidelberg #4 2048 1996 Dec 15 10:16:45

    Seawater intrusion; coastal aquifers; density-dependent flow and ... The seawater intrusion mechanism in coastal aquifers generally causes the occurrence of ... (4) The dynamic viscosity of the fluid does not change with respect to salinity and.

  10. Biologically mediated dissolution of volcanic glass in seawater

    NARCIS (Netherlands)

    Staudigel, H; Yayanos, A; Chastain, R; Davies, G.T.; Verdurmen, E.A Th; Schiffmann, P; Bourcier, R; de Baar, H.J.W.

    1998-01-01

    We studied the effects of biological mediation on the dissolution of basaltic glass in seawater. Experiments with typical seawater microbial populations were contrasted with a sterile control, and reactions were monitored chemically and isotopically. Biologically mediated experiments produce twice

  11. Concentration of uranium in seawater by flotation

    International Nuclear Information System (INIS)

    Nozaki, Toru; Yamashita, Hiroshi

    1986-01-01

    A method has been developed for the concentration of uranium in seawater by precipitation flotation-carbonate extraction-ion flotation. Uranium in seawater was coprecipitated with hydrated iron (III) oxide by adjusting the pH to 5.5 after addition of 1.0 x 10 -3 mol/l of iron (III) and agitating for 1 hr, and the precipitate was floated with 1.0 x 10 -5 mol/l of sodium oleate and 5.0 x 10 -5 mol/l of sodium lauryl sulfate by bubbling nitrogen through the seawater for 15 min. Uranium was extracted from the precipitate scum at the yield of 89 % with 100 ml of 1.8 % of ammonium carbonate solution by agitating for 2 hr, and floated with 1.2 x 10 -3 mol/l of cetylpyridinium chloride by bubbling nitrogen through the extract diluted 5-fold for 30 min in the recovery of about 100 %. The fairly selective recovery of uranium was obtained from 4 l of seawater at the yield of 87 % throughout the entire process. (author)

  12. Biofouling control of industrial seawater cooling towers

    KAUST Repository

    Al-Bloushi, Mohammed

    2017-01-01

    In this study, the research focuses on biofouling control in seawater cooling towers by investigating two different approaches. The first strategy addresses the use of alternative oxidants (i.e. ozone micro-bubbles and chlorine dioxide) in treatment of cooling towers. The second strategy investigates removing nutrients in seawater using granular activated carbon filter column and ultrafiltration to prevent the growth of microorganisms. Laboratory bench-scale tests in terms of temperature, cycle of concentration, dosage, etc. indicated that, at lower oxidant dosages (total residual oxidant (TRO) equivalent = 0.1 mg/l Cl2), chlorine dioxide had a better disinfection effect than chlorine and ozone. The performance of oxidizing biocides at pilot scale, operating at assorted conditions, showed that for the disinfectants tested, ozone could remove 95 % bioactivity of total number of bacteria and algae followed by chlorine dioxide at 85%, while conventional chlorine dosing only gave 60% reduction in bioactivities. Test results of GAC bio-filter showed that around 70 % removal of total organic carbon in the seawater feed was achieved and was effective in keeping the microbial growth to a minimum. The measured results from this study enable designers of seawater cooling towers to manage the biofouling problems when such cooling towers are extrapolated to a pilot scale.

  13. Technical note: Examining ozone deposition over seawater

    Science.gov (United States)

    Surface layer resistance plays an important role in determining ozone deposition velocity over sea-water and can be influenced by chemical interactions at the air-water interface. Here, we examine the effect of chemical interactions of iodide, dimethylsulfide, dissolved organic c...

  14. Durability of high performance concrete in seawater

    International Nuclear Information System (INIS)

    Amjad Hussain Memon; Salihuddin Radin Sumadi; Rabitah Handan

    2000-01-01

    This paper presents a report on the effects of blended cements on the durability of high performance concrete (HPC) in seawater. In this research the effect of seawater was investigated. The specimens were initially subjected to water curing for seven days inside the laboratory at room temperature, followed by seawater curing exposed to tidal zone until testing. In this study three levels of cement replacement (0%, 30% and 70%) were used. The combined use of chemical and mineral admixtures has resulted in a new generation of concrete called HPC. The HPC has been identified as one of the most important advanced materials necessary in the effort to build a nation's infrastructure. HPC opens new opportunities in the utilization of the industrial by-products (mineral admixtures) in the construction industry. As a matter of fact permeability is considered as one of the fundamental properties governing the durability of concrete in the marine environment. Results of this investigation indicated that the oxygen permeability values for the blended cement concretes at the age of one year are reduced by a factor of about 2 as compared to OPC control mix concrete. Therefore both blended cement concretes are expected to withstand in the seawater exposed to tidal zone without serious deterioration. (Author)

  15. A Survey of Tritium in Irish Seawater

    International Nuclear Information System (INIS)

    Currivan, L.; Kelleher, K.; McGinnity, P.; Wong, J.; McMahon, C.

    2013-07-01

    This report provides a comprehensive record of the study and measurements of tritium in Irish seawater undertaken by the Radiological Protection Institute of Ireland RPII. The majority of the samples analysed were found to have tritium concentrations below the limit of detection and a conservative assessment of radiation dose arising showed a negligible impact to the public. Tritium is discharged in large quantities from various nuclear facilities, and mostly in liquid form. For this reason it is included in the list of radioactive substances of interest to the OSPAR (Oslo-Paris) Convention to protect the marine environment of the North-East Atlantic. To fulfil its role within OSPAR, to provide technical support to the Irish Government, RPII carried out a project to determine the levels of tritium in seawater from around the Irish coast to supplement its routine marine monitoring programme. A total of 85 seawater samples were collected over a three year period and analysed at the RPII's laboratory. Given that the operational discharges for tritium from the nuclear fuel reprocessing plant at Sellafield, UK, are expected to increase due to current and planned decommissioning activities RPII will continue to monitor tritium levels in seawater around the Irish coast, including the Irish Sea, as part of its routine marine monitoring programme

  16. Potential Effects of Desalinated Seawater on Arteriosclerosis in Rats.

    Science.gov (United States)

    Duan, Lian; Zhang, Li Xia; Zhang, Shao Ping; Kong, Jian; Zhi, Hong; Zhang, Ming; Lu, Kai; Zhang, Hong Wei

    2017-10-01

    To evaluate the potential risk of arteriosclerosis caused by desalinated seawater, Wistar rats were provided desalinated seawater over a 1-year period, and blood samples were collected at 0, 90, 180, and 360 days. Blood calcium, magnesium, and arteriosclerosis-related indicators were investigated. Female rats treated with desalinated seawater for 180 days showed lower magnesium levels than the control rats (P seawater for 360 days (P seawater, and no increase in risk of arteriosclerosis was observed. Copyright © 2017 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  17. Recovery of uranium from sea-water

    International Nuclear Information System (INIS)

    Llewelyn, G.I.W.

    1976-01-01

    The possibility of extraction of uranium from sea-water on a sufficiently large scale to contribute significantly to national UK requirements is placed in perspective. It seems unlikely that there are sites around the UK coast where this could be achieved, and insufficient work has been done to be confident that sites exist anywhere to enable uranium extraction to be carried out on a large scale. Process techniques have been developed on a small scale, but extensive further research work would be necessary to reduce appreciably the present uncertainties. It would be unwise to expect uranium from sea-water to contribute significant amounts to the world's uranium demand for thermal reactors on an acceptable timescale. (author)

  18. Radiochemical determination of cesium-137 in seawater

    International Nuclear Information System (INIS)

    Cunha, I.I.L.; Munita, C.S.; Paiva, R.P.

    1990-01-01

    Seawater samples were collected from the Atlantic Ocean, in the vicinity of Ubatuba (Sao Paulo State - Brazil), acidified to pH 1 and stored in polyethylene containers. Cesium was precipitated with ammonium phospho molybdate (AMP), synthesized in our laboratory. The elements potassium and rubidium present in the seawater are also coprecipitated by AMP and adequate decontamination of the cesium is made by preparing a column by mixing Cs-137 AMP precipitate and asbestos. The interfering elements were eluted with 1.0 M ammonium nitrate solution whereas cesium was eluted with 1.0 M sodium hydroxide solution. Cesium was reprecipitated by acidifying the solution with concentrated hydrochloric acid. The overall chemical yield of cesium was of 75%. (author)

  19. Process for enriching uranium from seawater

    International Nuclear Information System (INIS)

    Heitkamp, D.; Inden, P.

    1982-01-01

    In selective elutriation of uranium deposited on titanium oxide hydrate by carbonate solution, only uranium should be dissolved from the absorption material forming carbonate compounds, without the deposited ballast ions, above all of magnesium, calcium and sodium being elutriated. The uranium elutriation according to the invention is therefore carried out in the presence of these ballast ions in the same concentrations as those in seawater. The carbonate concentration can only be raised as far as the solubility product of the basic magnesium carbonate permits, so that magnesium remains in the solution, as well as carbonate, in the concentration present in seawater. One must accept the absence of calcium ions in the elutriation solution, as their solubility product with carbonate is considerably less than that for magnesium. (orig./PW) [de

  20. Uncertainties in Climatological Seawater Density Calculations

    Science.gov (United States)

    Dai, Hao; Zhang, Xining

    2018-03-01

    In most applications, with seawater conductivity, temperature, and pressure data measured in situ by various observation instruments e.g., Conductivity-Temperature-Depth instruments (CTD), the density which has strong ties to ocean dynamics and so on is computed according to equations of state for seawater. This paper, based on density computational formulae in the Thermodynamic Equation of Seawater 2010 (TEOS-10), follows the Guide of the expression of Uncertainty in Measurement (GUM) and assesses the main sources of uncertainties. By virtue of climatological decades-average temperature/Practical Salinity/pressure data sets in the global ocean provided by the National Oceanic and Atmospheric Administration (NOAA), correlation coefficients between uncertainty sources are determined and the combined standard uncertainties uc>(ρ>) in seawater density calculations are evaluated. For grid points in the world ocean with 0.25° resolution, the standard deviations of uc>(ρ>) in vertical profiles cover the magnitude order of 10-4 kg m-3. The uc>(ρ>) means in vertical profiles of the Baltic Sea are about 0.028kg m-3 due to the larger scatter of Absolute Salinity anomaly. The distribution of the uc>(ρ>) means in vertical profiles of the world ocean except for the Baltic Sea, which covers the range of >(0.004,0.01>) kg m-3, is related to the correlation coefficient r>(SA,p>) between Absolute Salinity SA and pressure p. The results in the paper are based on sensors' measuring uncertainties of high accuracy CTD. Larger uncertainties in density calculations may arise if connected with lower sensors' specifications. This work may provide valuable uncertainty information required for reliability considerations of ocean circulation and global climate models.

  1. Effect of Greenhouse Gases Dissolved in Seawater.

    Science.gov (United States)

    Matsunaga, Shigeki

    2015-12-30

    A molecular dynamics simulation has been performed on the greenhouse gases carbon dioxide and methane dissolved in a sodium chloride aqueous solution, as a simple model of seawater. A carbon dioxide molecule is also treated as a hydrogen carbonate ion. The structure, coordination number, diffusion coefficient, shear viscosity, specific heat, and thermal conductivity of the solutions have been discussed. The anomalous behaviors of these properties, especially the negative pressure dependence of thermal conductivity, have been observed in the higher-pressure region.

  2. Drinking water in Cuba and seawater desalination

    International Nuclear Information System (INIS)

    Meneses-Ruiz, E.; Turtos-Carbonell, L.M.; Oviedo-Rivero, I.

    2004-01-01

    The lack of drinking water has become a problem at world level because, in many places, supplies are very limited and, in other places, their reserves have been drained. At the present time there are estimated to be around two thousand million people that don't have drinking water for several reasons, such as drought, contamination and the presence of saline waters not suitable for human consumption. Because of the human need for water, they have always taken residence in areas where the supply was guaranteed, sometimes impeding the exploitation of other areas that can be economically very interesting. However, this resource is usually very close and in abundance in the form of seawater but its salinity makes it unusable for many basic requirements. Humanity has been forced, therefore, to take into consideration the possibilities of the economic treatment of seawater. Cuba has regions where the supplies of drinking water are scarce and others where the lack of this resource limits economic exploitation. The present work is approached with regard to the situation of hydro resources in Cuba, it includes: a description of the main hydrographic basins of the country; the contamination levels of the waters and the measures for mitigation; analysis of the supplies and demand for drinking water and its quality; regulatory aspects. The state of seawater desalination in Cuba is also included and the possibility of its realisation using nuclear energy and the advantages that this would bring is evaluated. (author)

  3. Mimicking Seawater For Culturing Marine Bacteria

    DEFF Research Database (Denmark)

    Rygaard, Anita Mac; Sonnenschein, Eva; Gram, Lone

    2015-01-01

    Only about 1% of marine bacteria have been brought into culture using traditional techniques. The purpose of this study was to investigate if mimicking the natural bacterial environment can increase culturability.We used marine substrates containing defined algal polymers or gellan gum as solidif......Only about 1% of marine bacteria have been brought into culture using traditional techniques. The purpose of this study was to investigate if mimicking the natural bacterial environment can increase culturability.We used marine substrates containing defined algal polymers or gellan gum...... as solidifying agents, and enumerated bacteria from seawater and algal exudates. We tested if culturability could be influenced by addition of quorum sensing signals (AHLs). All plates were incubated at 15°C. Bacterial counts (CFU/g) from algal exudates from brown algae were highest on media containing algal...... polymers. In general, bacteria isolated from algal exudates preferred more rich media than bacteria isolated from seawater. Overall, culturability ranged from 0.01 to 0.8% as compared to total cell count. Substitution of agar with gellan gum increased the culturability of seawater bacteria approximately...

  4. 60Co levels in the seawater regions

    International Nuclear Information System (INIS)

    Yoshioka, Mitsuo

    1983-01-01

    In order to assess the contribution from nuclear power facilities to the 60 Co levels in seawater regions, it is essential to grasp the background values of 60 Co. The following matters are described: 60 Co sources and the respective inputs; nuclear test fallout and nuclear power plants; the 60 Co levels in overseas countries; the 60 Co levels in Japan; the 60 Co levels from nuclear power plants in Fukui prefecture. In the seawater regions around Japan, there have been numerous instances of 60 Co detection; several pCi/kg of dry earth in sea bottom earth and about 1 pCi/kg of raw material in marine life can be considered as the background levels due to nuclear test fallout and nuclear-powered submarines. In the seawater regions of Fukui prefecture, the 60 Co levels appreciably exceeded the above background due to the nuclear power plants, which are insignificant concerning the radiation exposure of the local people. (Mori, K.)

  5. Seawater movement in the Japan Sea inferred from 14C measurement in seawater

    International Nuclear Information System (INIS)

    Otosaka, Shigeyoshi; Tanaka, Takayuki; Togawa, Orihiko; Amano, Hikaru; Aramaki, Takafumi

    2008-01-01

    Research Group for Environmental Science, JAEA has carried out oceanographic observations in the Japan Sea since 1997 to clarify the biogeochemical cycle in the Japan Sea. More than 3,000 seawater samples for measurement of radiocarbon were collected during the observations, and radiocarbon in the seawater samples was measured at AMS facility in JAEA Mutsu. In this paper, formation and circulation of water mass in the northern Japan Sea were discussed using analysis of radiocarbon and hydrographic data (e.g. salinity, temperature, nutrients). (author)

  6. Conceptual design on uranium recovery plant from seawater

    International Nuclear Information System (INIS)

    Kato, Toshiaki; Okugawa, Katsumi; Sugihara, Yutaka; Matsumura, Tsuyoshi

    1999-01-01

    Uranium containing in seawater is extremely low concentration, which is about 3 mg (3 ppb) per 1 ton of seawater. Recently, a report on development of a more effective collector of uranium in seawater (a radiation graft polymerization product of amidoxime onto polyethylene fiber) was issued by Japan Atomic Energy Research Institute. In this paper, an outline design of a uranium recovery plant from seawater was conducted on a base of the collector. As a result of cost estimation, the collection cost of seawater uranium using this method was much higher than that of uranium mine on land and described in the Red Book for mineral uranium cost. In order to make the seawater uranium cost comparable to the on-land uranium cost, it is necessary to establish comprehensive efforts in future technical development, such as development in absorption property of uranium with the collector, resolution method using less HCl, and so forth. (G.K.)

  7. Simultaneous Extraction of Lithium and Hydrogen from Seawater

    Science.gov (United States)

    2011-08-22

    N00014-10-M-0234 20126083 0001AD Dr. Pyoungho Choi University of Central Florida/Florida Solar Energy Center 1679 Clearlake Road Cocoa FL 32922-5703...South America (Bolivia and Chile), Australia, and China. There have been debates as to whether the lithium supplies would meet the surging demand...extract the lithium in seawater should be developed [1]. Seawater is also the ultimate source of hydrogen. The production of hydrogen from seawater is

  8. Distributed Memory Parallel Computing with SEAWAT

    Science.gov (United States)

    Verkaik, J.; Huizer, S.; van Engelen, J.; Oude Essink, G.; Ram, R.; Vuik, K.

    2017-12-01

    Fresh groundwater reserves in coastal aquifers are threatened by sea-level rise, extreme weather conditions, increasing urbanization and associated groundwater extraction rates. To counteract these threats, accurate high-resolution numerical models are required to optimize the management of these precious reserves. The major model drawbacks are long run times and large memory requirements, limiting the predictive power of these models. Distributed memory parallel computing is an efficient technique for reducing run times and memory requirements, where the problem is divided over multiple processor cores. A new Parallel Krylov Solver (PKS) for SEAWAT is presented. PKS has recently been applied to MODFLOW and includes Conjugate Gradient (CG) and Biconjugate Gradient Stabilized (BiCGSTAB) linear accelerators. Both accelerators are preconditioned by an overlapping additive Schwarz preconditioner in a way that: a) subdomains are partitioned using Recursive Coordinate Bisection (RCB) load balancing, b) each subdomain uses local memory only and communicates with other subdomains by Message Passing Interface (MPI) within the linear accelerator, c) it is fully integrated in SEAWAT. Within SEAWAT, the PKS-CG solver replaces the Preconditioned Conjugate Gradient (PCG) solver for solving the variable-density groundwater flow equation and the PKS-BiCGSTAB solver replaces the Generalized Conjugate Gradient (GCG) solver for solving the advection-diffusion equation. PKS supports the third-order Total Variation Diminishing (TVD) scheme for computing advection. Benchmarks were performed on the Dutch national supercomputer (https://userinfo.surfsara.nl/systems/cartesius) using up to 128 cores, for a synthetic 3D Henry model (100 million cells) and the real-life Sand Engine model ( 10 million cells). The Sand Engine model was used to investigate the potential effect of the long-term morphological evolution of a large sand replenishment and climate change on fresh groundwater resources

  9. Effect of Greenhouse Gases Dissolved in Seawater

    Directory of Open Access Journals (Sweden)

    Shigeki Matsunaga

    2015-12-01

    Full Text Available A molecular dynamics simulation has been performed on the greenhouse gases carbon dioxide and methane dissolved in a sodium chloride aqueous solution, as a simple model of seawater. A carbon dioxide molecule is also treated as a hydrogen carbonate ion. The structure, coordination number, diffusion coefficient, shear viscosity, specific heat, and thermal conductivity of the solutions have been discussed. The anomalous behaviors of these properties, especially the negative pressure dependence of thermal conductivity, have been observed in the higher-pressure region.

  10. Mortality of fecal bacteria in seawater

    International Nuclear Information System (INIS)

    Garcia-Lara, J.; Menon, P.; Servais, P.; Billen, G.

    1991-01-01

    The authors propose a method for determining the mortality rate for allochthonous bacteria released in aquatic environments without interference due to the loss of culturability in specific culture media. This method consists of following the disappearance of radioactivity from the trichloracetic acid-insoluble fraction in water samples to which [ 3 H]thymidine-prelabeled allochthonous bacteria have been added. In coastal seawater, they found that the actual rate of disappearance of fecal bacteria was 1 order of magnitude lower than the rate of loss of culturability on specific media. Minor adaptation of the procedure may facilitate assessment of the effect of protozoan grazing and bacteriophage lysis on the overall bacterial mortality rate

  11. Enhancement of Extraction of Uranium from Seawater

    Energy Technology Data Exchange (ETDEWEB)

    Al-Sheikhly, Mohamad [Univ. of Maryland, College Park, MD (United States); Dietz, Travis [Univ. of Maryland, College Park, MD (United States); Tsinas, Zois [Univ. of Maryland, College Park, MD (United States); Tomaszewski, Claire [Univ. of Maryland, College Park, MD (United States); Pazos, Ileana M. [Univ. of Maryland, College Park, MD (United States); Nigliazzo, Olga [The Catholic Univ. of America, Washington, DC (United States); Li, Weixing [The Catholic Univ. of America, Washington, DC (United States); Adel-Hadadi, Mohamad [Univ. of Maryland, College Park, MD (United States); Barkatt, Aaron [Univ. of Palermo (Italy)

    2016-04-01

    Even at a concentration of 3 μg/L, the world’s oceans contain a thousand times more uranium than currently know terrestrial sources. In order to take advantage of this stockpile, methods and materials must be developed to extract it efficiently, a difficult task considering the very low concentration of the element and the competition for extraction by other atoms in seawater such as sodium, calcium, and vanadium. The majority of current research on methods to extract uranium from seawater are vertical explorations of the grafting of amidoxime ligand, which was originally discovered and promoted by Japanese studies in the late 1980s. Our study expands on this research horizontally by exploring the effectiveness of novel uranium extraction ligands grafted to the surface of polymer substrates using radiation. Through this expansion, a greater understanding of uranium binding chemistry and radiation grafting effects on polymers has been obtained. While amidoxime-functionalized fabrics have been shown to have the greatest extraction efficiency so far, they suffer from an extensive chemical processing step which involves treatment with powerful basic solutions. Not only does this add to the chemical waste produced in the extraction process and add to the method’s complexity, but it also significantly impacts the regenerability of the amidoxime fabric. The approach of this project has been to utilize alternative, commercially available monomers capable of extracting uranium and containing a carbon-carbon double bond to allow it to be grafted using radiation, specifically phosphate, oxalate, and azo monomers. The use of commercially available monomers and radiation grafting with electron beam or gamma irradiation will allow for an easily scalable fabrication process once the technology has been optimized. The need to develop a cheap and reliable method for extracting uranium from seawater is extremely valuable to energy independence and will extend the quantity of

  12. Determination of radioactive strontium in seawater

    International Nuclear Information System (INIS)

    Grahek, Zeljko; Rozmaric Macefat, Martina

    2005-01-01

    This paper describes the procedures of isolating strontium and yttrium from seawater that enable the determination of 89,90 Sr. In one procedure, strontium is directly isolated from seawater on the column filled with Sr resin by binding of strontium to the resin from 3 M HNO 3 in a seawater, and successive elution with HNO 3 . In others, strontium is precipitated from seawater with (NH 4 ) 2 CO 3 , followed by isolation on a Sr column or an anion exchange column. It is shown that strontium precipitation is optimal with concentration of 0.3 M (NH 4 ) 2 CO 3 at pH = 11. In these conditions, 100% Y, 78% Sr, 80% Ca and 50% Mg are precipitated. Strontium is bound on to Sr column from 5 to 8 M HNO 3 , separated from other elements by elution with 3 M HNO 3 and 0.05 M HNO 3 . Strontium and yttrium are bound on to anion exchange column from alcoholic solutions of nitric acid. The optimum mixture of alcohols for sample binding is a mixture of ethanol and methanol with the volume ratio 1:3. Strontium and yttrium are separated from Mg, Ca, K, and other elements by elution with 0.25 M HNO 3 in the mixture of ethanol and methanol. After the separation, yttrium and strontium are eluted from the column with water or methanol. In the procedure of direct isolation from 1 l of the sample, the average recovery of 50% was obtained. In the remaining two procedures, the strontium recovery was about 60% for the Sr column and 65% for anion exchange column. Recovery of yttrium is about 70% for the anion exchange column. It turned out that the procedure with the Sr resin (direct isolation and isolation after precipitation) is simpler and faster in the phase of the isolation on the column in comparison with the procedure with the anion exchanger. The procedure with the anion exchanger, however, enables the simultaneous isolation of yttrium and strontium and rapid determination of 89,90 Sr. These procedures were tested by determination of 89,90 Sr on liquid scintillation counter and Cherenkov

  13. Enhancement of Extraction of Uranium from Seawater

    International Nuclear Information System (INIS)

    Al-Sheikhly, Mohamad; Dietz, Travis; Tsinas, Zois; Tomaszewski, Claire; Pazos, Ileana M.; Nigliazzo, Olga; Li, Weixing; Adel-Hadadi, Mohamad; Barkatt, Aaron

    2016-01-01

    Even at a concentration of 3 @@g/L, the world@@@s oceans contain a thousand times more uranium than currently know terrestrial sources. In order to take advantage of this stockpile, methods and materials must be developed to extract it efficiently, a difficult task considering the very low concentration of the element and the competition for extraction by other atoms in seawater such as sodium, calcium, and vanadium. The majority of current research on methods to extract uranium from seawater are vertical explorations of the grafting of amidoxime ligand, which was originally discovered and promoted by Japanese studies in the late 1980s. Our study expands on this research horizontally by exploring the effectiveness of novel uranium extraction ligands grafted to the surface of polymer substrates using radiation. Through this expansion, a greater understanding of uranium binding chemistry and radiation grafting effects on polymers has been obtained. While amidoxime-functionalized fabrics have been shown to have the greatest extraction efficiency so far, they suffer from an extensive chemical processing step which involves treatment with powerful basic solutions. Not only does this add to the chemical waste produced in the extraction process and add to the method@@@s complexity, but it also significantly impacts the regenerability of the amidoxime fabric. The approach of this project has been to utilize alternative, commercially available monomers capable of extracting uranium and containing a carbon-carbon double bond to allow it to be grafted using radiation, specifically phosphate, oxalate, and azo monomers. The use of commercially available monomers and radiation grafting with electron beam or gamma irradiation will allow for an easily scalable fabrication process once the technology has been optimized. The need to develop a cheap and reliable method for extracting uranium from seawater is extremely valuable to energy independence and will extend the quantity of

  14. Corrosion and Protection of Metal in the Seawater Desalination

    Science.gov (United States)

    Hou, Xiangyu; Gao, Lili; Cui, Zhendong; Yin, Jianhua

    2018-01-01

    Seawater desalination develops rapid for it can solve water scarcity efficiently. However, corrosion problem in the seawater desalination system is more serious than that in normal water. So, it is important to pay attention to the corrosion and protection of metal in seawater desalination. The corrosion characteristics and corrosion types of metal in the seawater desalination system are introduced in this paper; In addition, corrosion protect methods and main influencing factors are stated, the latest new technologies about anti-corrosion with quantum energy assisted and magnetic inhibitor are presented.

  15. The strontium isotopic composition of seawater, and seawater-oceanic crust interaction

    International Nuclear Information System (INIS)

    Spooner, E.T.C.

    1976-01-01

    The 87 Sr/ 86 Sr ratio of seawater strontium (0.7091) is less than the 87 Sr/ 86 Sr ratio of dissolved strontium delivered to the oceans by continental run-off (approximately 0.716). Isotope exchange with strontium isotopically lighter oceanic crust during hydrothermal convection within spreading oceanic ridges can explain this observation. In quantitative terms, the current 87 Sr/ 86 Sr ratio of seawater (0.7091) may be maintained by balancing the continental run-off flux of strontium (0.59 x 10 12 g/yr) against a hydrothermal recirculation flux of 3.6 x 10 12 g/yr, during which the 87 Sr/ 86 Sr ratio of seawater drops by 0.0011. A concomitant mean increase in the 87 Sr/ 86 Sr ratio of the upper 4.5 km of oceanic crust of 0.0010 (0.7029-0.7039) should be produced. This required 87 Sr enrichment has been observed in hydrothermally metamorphosed ophiolitic rocks from the Troodos Massif, Cyprus. The post-Upper Cretaceous increase in the strontium isotopic composition of seawater (approximately 0.7075-0.7091) covaries smoothly with inferred increase in land area. This suggests that during this period the main factor which has caused variability in the 87 Sr/ 86 Sr ratio of seawater strontium could have been variation in the magnitude of the continental run-off flux caused by variation in land area. Variations in land area may themselves have been partly a consequence of variations in global mean sea-floor spreading rate. (Auth.)

  16. Post-Mesozoic Rapid Increase of Seawater Mg/Ca due to Enhanced Mantle-Seawater Interaction

    OpenAIRE

    Marco Ligi; Enrico Bonatti; Marco Cuffaro; Daniele Brunelli

    2013-01-01

    The seawater Mg/Ca ratio increased significantly from ~ 80?Ma to present, as suggested by studies of carbonate veins in oceanic basalts and of fluid inclusions in halite. We show here that reactions of mantle-derived peridotites with seawater along slow spreading mid-ocean ridges contributed to the post-Cretaceous Mg/Ca increase. These reactions can release to modern seawater up to 20% of the yearly Mg river input. However, no significant peridotite-seawater interaction and Mg-release to the ...

  17. Corrosion of barrier materials in seawater environments

    International Nuclear Information System (INIS)

    Heiser, J.H.; Soo, P.

    1995-07-01

    A brief review has been carried out on the performance of barrier materials for low-level radioactive wastes in seawater environments. The environments include those for shallower coastal waters as well as the deep ocean (down to 3800 m). The review is mainly focused on metallic materials since they are the most common for seawater service and they have the largest data base. Information from the literature is usually pertinent to shallower coastal locations, but there is a valuable source of corrosion data obtained from several studies of metallic specimens exposed to ocean-bed conditions. In addition, the corrosion of carbon steel barriers has been evaluated for actual waste containers that were retrieved from previously-used disposal sites in the Atlantic and Pacific Oceans. Of the metallic materials studied, carbon steel showed the least corrosion resistance. Failure by non-uniform attack in a typical waste container could occur in as little as 25 y in some ocean environments ' Penetration by local attack, such as pitting and crevice corrosion resistance was also observed for more expensive materials such as low-alloy steels, stainless steels, titanium alloys, zirconium alloys, copper alloys, nickel alloys, aluminum alloys, and lead alloys

  18. Desalination of seawater: a nuclear solution

    International Nuclear Information System (INIS)

    Basta, H.

    2003-01-01

    1,4 milliard human beings do not benefit of sufficient clean water supply. The desalting of seawater is a valid and tested solution in terms of technology but the 2 physical processes involved, evaporation and reverse osmosis are energy-greedy. Only rich countries like Kuwait or Saudi-Arabia can afford producing massive volumes of fresh water from seawater. Today the total world capacity of desalting reaches 30 milliard m 3 a day with 10.000 operating units, half of which installed in middle-east countries. The use of nuclear energy is a solution to lower costs. In Aktau (Kazakhstan) a BN-350 fast reactor has been producing a 135 MW electrical output and 80.000 m 3 of fresh water a day for 27 years. In Japan about 10 desalting units have been coupled to nuclear power plants. A company (Eskom) based in South-Africa is developing a new concept of high temperature reactor: the PBMR (pebble bed modular reactor). The suitability of this reactor has been assessed for desalting and it appears that its main assets are its size: 165 MW electrical output (400 MW thermal output) and its Brayton cycle. Other characteristics such as the coolant (helium), the type of fuel (8% enriched uranium encapsulated in carbon), the low design and maintenance costs, the short building time (2 years) are important when considering issues like nuclear safety, non-proliferation and profitability. (A.C.)

  19. Microbial control of seawater by microfiltration

    Directory of Open Access Journals (Sweden)

    Wilmer Soler T

    2010-08-01

    Full Text Available Recent scientific literature presents seawater as a potential aid to solve a variety of health diseases in animals and human beings because by means of its mineral and trace elements content. In Colombia, Nicaragua and Spain it is collected in a natural way from de shore and drunk; however, this can represent a health risk because of the problems related to chemical and microbiological contamination. Microbial control of seawater allows the improvement of its microbiological quality. Objective: to compare the efficiency of three microbial control methods: microfiltration, solar exposition and quarantine. Methodology: 30 samples were collected in 20-liter high density polyethylene containers in three different places in the Colombian Atlantic coast. Results: 15 samples out of 30 showed the presence of bacteria such as E. coli and halophiles bacteria like Vibrio and Aeromonas. Microfiltration through ceramic filters of 0.5 µm produces disinfection in 100% of the samples but the quarantine for five months and solar disinfection are effective in 66 and 21% respectively. The latter requires certain weather conditions to achieve disinfection and it only allows managing small quantities of water. Dicussion: Considering chemical contamination in some places which cannot be controlled through disinfection methods, the collection of water offshore in clean places is suggested and then microfiltration treatment should be performed.

  20. On the classification of seawater intrusion

    Science.gov (United States)

    Werner, Adrian D.

    2017-08-01

    Seawater intrusion (SWI) arising from aquifer depletion is often classified as ;active; or ;passive;, depending on whether seawater moves in the same direction as groundwater flow or not. However, recent studies have demonstrated that alternative forms of active SWI show distinctly different characteristics, to the degree that the term ;active SWI; may be misleading without additional qualification. In response, this article proposes to modify hydrogeology lexicon by defining and characterizing three classes of SWI, namely passive SWI, passive-active SWI and active SWI. The threshold parameter combinations for the onset of each form of SWI are developed using sharp-interface, steady-state analytical solutions. Numerical simulation is then applied to a hypothetical case study to test the developed theory and to provide additional insights into dispersive SWI behavior. The results indicate that the three classes of SWI are readily predictable, with the exception of active SWI occurring in the presence of distributed recharge. The key characteristics of each SWI class are described to distinguish their most defining features. For example, active SWI occurring in aquifers receiving distributed recharge only creates watertable salinization downstream of the groundwater mound and only where dispersion effects are significant. The revised classification of SWI proposed in this article, along with the analysis of thresholds and SWI characteristics, provides coastal aquifer custodians with an improved basis upon which to expect salinization mechanisms to impact freshwater availability following aquifer depletion.

  1. Corrosion of mild steel, copper and brass in crude oil / seawater mixture

    Digital Repository Service at National Institute of Oceanography (India)

    PrabhaDevi, S.; Sawant, S.S.; Wagh, A.B.

    Mild steel, copper and brass coupons were introduced in natural seawater containing varying amount of crude oil. Mild steel showed higher rate of corrosion in seawater containing oil and lower corrosion rate in natural as well as artificial seawater...

  2. Investigation of adsorbers for the extracting of uranium from seawater

    International Nuclear Information System (INIS)

    Witte, E.G.; Astheimer, L.; Schenk, H.J.; Schwochau, K.

    1979-01-01

    Organic ion exchangers have been tested with respect to their efficiency uranium from seawater. A complexing polymer resin which combines fast uptake of uranium with high selectivity is found to be able to accumulate uranium from natural seawater by a factor of 2.6 x 10 5 . (orig.) 891 HK/orig. 892 MKO [de

  3. Contribution of Seawater Surfactants to Generated Primary Marine Aerosol Particles

    Science.gov (United States)

    Frossard, A. A.; Gerard, V.; Duplessis, P.; Kinsey, J. D.; Lu, X.; Zhu, Y.; Bisgrove, J.; Maben, J. R.; Long, M. S.; Chang, R.; Beaupre, S. R.; Kieber, D. J.; Keene, W. C.; Noziere, B.; Cohen, R. C.

    2017-12-01

    Surfactants account for minor fractions of total organic carbon in the ocean but may have major impacts on the surface tension of bursting bubbles at the sea surface that drive the production of primary marine aerosol particles (PMA). Surfactants associated with marine aerosol may also significantly reduce the surface tension of water thereby increasing the potential for cloud droplet activation and growth. During September and October 2016, PMA were produced from bursting bubbles in seawater using a high capacity generator at two biologically productive and two oligotrophic stations in the western North Atlantic, as part of a cruise on the R/V Endeavor. Surfactants were extracted from paired PMA and seawater samples, and their ionic compositions, total concentrations, and critical micelle concentrations (CMC) were quantified and compared for the four hydrographic stations. Higher surfactant concentrations were determined in the aerosol produced from biologically productive seawater compared to oligotrophic seawater, and the surfactants extracted from productive seawater were stronger (had lower CMCs) than those in the oligotrophic seawater. Surfactants associated with PMA and seawater in productive regions also varied over diel cycles, whereas those in the oligotrophic regions did not. This work demonstrates a direct link between surfactants in seawater and those in PMA.

  4. Coagulation and ultrafiltration in seawater reverse osmosis pretreatment

    NARCIS (Netherlands)

    Tabatabai, S.A.A.

    2014-01-01

    Seawater desalination is a globally expanding coastal industry with an installed capacity of over 80 million m3/day. Algal blooms pose a challenge to the operation of seawater reverse osmosis (SWRO) membranes and pre-treatment systems due to high concentrations of algal cells and algal organic

  5. Degradation of riverine dissolved organic matter by seawater bacteria

    NARCIS (Netherlands)

    Rochelle-Newall, E.J.; Pizay, M-D.; Middelburg, J.J.; Boschker, H.T.S.; Gattuso, J.P.

    2004-01-01

    The functional response of a seawater bacterial community transplanted into freshwater dissolved organic matter (DOM) was investigated together with the response of natural populations of bacteria to size-fractioned natural source water. Seawater bacteria were incubated over a period of 8 d in

  6. Progress in recovery technology for uranium from seawater

    International Nuclear Information System (INIS)

    Sugo, Takanobu; Saito, Kyoichi.

    1994-01-01

    By the facts that the research group in Japan improved the performance of amidoxime resin which is the adsorbent for collecting seawater uranium, proposed the method of mooring floating bodies utilizing sea current and waves as the adsorption system, and further, verified the results of laboratory basic experiment by marine experiment, the technology of collecting seawater uranium has progressed. After the oil crisis, various countries started the research on seawater uranium, but only Japan has continued the systematic study up to now. In this report, the research on seawater uranium collection carried out so far is summarized, and the characteristics of the adsorbent which was synthesized by radiation graft polymerization and the results of the uranium collection test using coastal seawater are reported. In seawater of 1 m 3 , the uranium of 3.3 mg is dissolved in the form of uranyl tricarbonate complex ions. In the total quantity of seawater, the dissolved uranium amounts to about 4.6 billion tons, about 1000 times of the uranium resources on land. The research on seawater uranium collection and the performance of uranium adsorption of synthesized amidoxime fibers are reported. (K.I.)

  7. Biodegradation of phenanthrene in artificial seawater by using free ...

    African Journals Online (AJOL)

    and related aromatic compounds. This paper reports the domestication of strain Sphingomonas sp. GY2B in artificial seawater (AS) and the immobilization of the strain onto rice straw. Results showed that adding 85% artificial seawater had very low impact on the growth and phenanthrene degradation ability of strain GY2B ...

  8. Sulfate was a trace constituent of Archean seawater

    DEFF Research Database (Denmark)

    Crowe, Sean Andrew; Paris, Guillaume; Katsev, Sergei

    2014-01-01

    In the low-oxygen Archean world (>2400 million years ago), seawater sulfate concentrations were much lower than today, yet open questions frustrate the translation of modern measurements of sulfur isotope fractionations into estimates of Archean seawater sulfate concentrations. In the water column...

  9. Modelling of a transmembrane evaporation module for desalination of seawater

    NARCIS (Netherlands)

    Guijt, C.M.; Racz, I.G.; van Heuven, Jan Willem; Reith, T.; de Haan, A.B.

    1999-01-01

    Transmembrane evaporation (often called membrane distillation) carried out in a countercurrent flow module, in which incoming cold seawater is heated by the condensing product water flow, is a promising technology for low-cost seawater desalination. This paper presents a model for preliminary design

  10. Analysis of seawater flow through optical fiber

    Science.gov (United States)

    Fernández López, Sheila; Carrera Ramírez, Jesús; Rodriguez Sinobar, Leonor; Benitez, Javier; Rossi, Riccardo; Laresse de Tetto, Antonia

    2015-04-01

    The relation between sea and coastal aquifer is very important to the human populations living in coastal areas. The interrelation involves the submarine ground water discharge of relatively fresh water to the sea and the intrusion of sea water into the aquifer, which impairs the quality of ground water. The main process in seawater intrusion is managed by fluid-density effects which control the displacement of saline water. The underlain salinity acts as the restoring force, while hydrodynamic dispersion and convection lead to a mixing and vertical displacement of the brine. Because of this, a good definition of this saltwater-freshwater interface is needed what is intimately joined to the study of the movements (velocity fields) of fresh and salt water. As it is well known, the flow of salt water studied in seawater intrusion in stationary state, is nearly null or very low. However, in the rest of cases, this flux can be very important, so it is necessary its study to a better comprehension of this process. One possible manner of carry out this analysis is through the data from optical fiber. So, to research the distribution and velocity of the fresh and saltwater in the aquifer, a fiber optic system (OF) has been installed in Argentona (Baix Maresme, Catalonia). The main objective is to obtain the distributed temperature measurements (OF-DTS) and made progress in the interpretation of the dynamic processes of water. For some applications, the optical fiber acts as a passive temperature sensor but in our case, the technique Heated Active Fiber Optic will be used. This is based on the thermal response of the ground as a heat emission source is introduced. The thermal properties of the soil, dependent variables of soil water content, will make a specific temperature distribution around the cable. From the analyzed data we will deduce the velocity field, the real objective of our problem. To simulate this phenomenon and the coupled transport and flow problem

  11. Lawrence Livermore Laboratory concept for uranium recovery from seawater

    International Nuclear Information System (INIS)

    Gregg, D.; Wang, F.

    1980-01-01

    The Lawrence Livermore Laboratory concept for uranium recovery from seawater involves the following process steps: (1) produce activated carbon via a coal gasification plant; (2) contact activated carbon sorbent with seawater using a settling process (no pumping of seawater); (3) vacuum activated carbon from sea floor; (4) gasify or burn activated carbon (further concentrating the uranium in the ash); (5) extract the uranium from the rich ash ore by conventional techniques. The process advantages are: (1) eliminates seawater pumping, the need for an illuent, and the need for a fresh water wash; (2) should result in much lower capital investment and regional process energy. Major process issues are: (1) uranium loading on activated carbon; (2) activated carbon modifications required to improve the sorbtion performance; (3) activated carbon particle size needed to meet system requirements; (4) minimization of sorbent losses when contacted with seawater

  12. Inhibition of Sodium Benzoate on Stainless Steel in Tropical Seawater

    International Nuclear Information System (INIS)

    Seoh, S. Y.; Senin, H. B.; Nik, W. N. Wan; Amin, M. M.

    2007-01-01

    The inhibition of sodium benzoate for stainless steel controlling corrosion was studied in seawater at room temperature. Three sets of sample have been immersed in seawater containing sodium benzoate with the concentrations of 0.3M, 0.6M and 1.0M respectively. One set of sample has been immersed in seawater without adding any sodium benzoate. It was found that the highest corrosion rate was observed for the stainless steel with no inhibitor was added to the seawater. As the concentration of sodium benzoate being increased, the corrosion rate is decreases. Results show that by the addition of 1.0M of sodium benzoate in seawater samples, it giving ≥ 90% efficiencies

  13. Proteolytic enzymes in seawater: contribution of prokaryotes and protists

    Science.gov (United States)

    Obayashi, Y.; Suzuki, S.

    2016-02-01

    Proteolytic enzyme is one of the major catalysts of microbial processing of organic matter in biogeochemical cycle. Here we summarize some of our studies about proteases in seawater, including 1) distribution of protease activities in coastal and oceanic seawater, 2) responses of microbial community and protease activities in seawater to organic matter amending, and 3) possible contribution of heterotrophic protists besides prokaryotes to proteases in seawater, to clarify cleared facts and remaining questions. Activities of aminopeptidases, trypsin-type and chymotrypsin-type proteases were detected from both coastal and oceanic seawater by using MCA-substrate assay. Significant activities were detected from not only particulate (cell-associated) fraction but also dissolved fraction of seawater, especially for trypsin-type and chymotrypsin-type proteases. Hydrolytic enzymes in seawater have been commonly thought to be mainly derived from heterotrophic prokaryotes; however, it was difficult to determine actual source organisms of dissolved enzymes in natural seawater. Our experiment with addition of dissolved protein to subtropical oligotrophic Pacific water showed drastically enhancement of the protease activities especially aminopeptidases in seawater, and the prokaryotic community structure simultaneously changed to be dominant of Bacteroidetes, indicating that heterotrophic bacteria were actually one of the sources of proteases in seawater. Another microcosm experiment with free-living marine heterotrophic ciliate Paranophrys marina together with an associated bacterium showed that extracellular trypsin-type activity was mainly attributed to the ciliate. The protist seemed to work in organic matter digestion in addition to be a grazer. From the results, we propose a system of organic matter digestion by prokaryotes and protists in aquatic environments, although their actual contribution in natural environments should be estimated in future studies.

  14. Post-Mesozoic Rapid Increase of Seawater Mg/Ca due to Enhanced Mantle-Seawater Interaction

    Science.gov (United States)

    Ligi, Marco; Bonatti, Enrico; Cuffaro, Marco; Brunelli, Daniele

    2013-01-01

    The seawater Mg/Ca ratio increased significantly from ~ 80 Ma to present, as suggested by studies of carbonate veins in oceanic basalts and of fluid inclusions in halite. We show here that reactions of mantle-derived peridotites with seawater along slow spreading mid-ocean ridges contributed to the post-Cretaceous Mg/Ca increase. These reactions can release to modern seawater up to 20% of the yearly Mg river input. However, no significant peridotite-seawater interaction and Mg-release to the ocean occur in fast spreading, East Pacific Rise-type ridges. The Mesozoic Pangean superocean implies a hot fast spreading ridge system. This prevented peridotite-seawater interaction and Mg release to the Mesozoic ocean, but favored hydrothermal Mg capture and Ca release by the basaltic crust, resulting in a low seawater Mg/Ca ratio. Continent dispersal and development of slow spreading ridges allowed Mg release to the ocean by peridotite-seawater reactions, contributing to the increase of the Mg/Ca ratio of post-Mesozoic seawater. PMID:24067442

  15. Evaluation of seawater corrosion of SSCs

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-08-15

    In the unit 1 to unit 4 of the Fukushima Daiichi Nuclear Power Plant, seawater was injected in reactor pressure vessels and spent fuel pools in order to cool nuclear fuel after the disaster of the 2011 off the Pacific coast of Tohoku Earthquake and Tsunami. In fiscal 2012, overall plan of this project has been developed in consideration of corrosion events that might be assumed reactor pressure vessels, spent fuel pools and primary containment vessels of Fukushima Daiichi Nuclear Power Station that was designated to be as the 'Specified Nuclear Power Facilities'. In this project, crevice corrosion susceptibility of stainless steel, galvanic corrosion of aluminum alloy, and uniform corrosion of carbon steel piping will be evaluated. (author)

  16. Energy Implications of Seawater Desalination (Invited)

    Science.gov (United States)

    Cooley, H.; Heberger, M. G.

    2013-12-01

    Freshwater has traditionally come from rivers, lakes, streams, and groundwater aquifers. As demand increases and climate change alters the location and timing of water supply, these traditional sources are becoming unavailable, more difficult, or increasingly expensive to develop. As a result, many communities are switching to alternative sources of water. Interest in pursuing seawater desalination is high in many coastal communities. In California, for example, 17 plants are proposed for development along the California coast and two in Mexico. Water managers are pursing desalination because is a local supply that can help diversify the water supply portfolio. Additionally, it is a reliable supply, which can be especially valuable during a drought. But removing the salt from seawater is an energy-intensive process that consumes more energy per gallon than most other water supply and treatment options. These energy requirements are key factors that will impact the extent and success of desalination in California. Energy requirements for seawater desalination average about 4.0 kWh per cubic meter (m3) of water produced. By comparison, the least energy-intensive options of local sources of groundwater and surface water require 0 - 0.90 kWh per m3; wastewater reuse, depending on treatment levels, may require from 0.26 - 2.2 kWh per m3. Beyond the electricity required for the desalination facility itself, producing any new source of water, including through desalination, increases the amount of energy required to deliver and use the water produced as well as collect, treat, and dispose of the wastewater generated. Energy is the largest single variable cost for a desalination plant, varying from one-third to more than one-half the cost of produced water. Building a desalination plant may reduce a water utility's exposure to water reliability risks at the added expense of an increase in exposure to energy price risk. In dependent on hydropower, electricity prices tend to

  17. Herbicide Persistence in Seawater Simulation Experiments.

    Directory of Open Access Journals (Sweden)

    Philip Mercurio

    Full Text Available Herbicides are detected year-round in marine waters, including those of the World Heritage listed Great Barrier Reef (GBR. The few previous studies that have investigated herbicide persistence in seawater generally reported half-lives in the order of months, and several studies were too short to detect significant degradation. Here we investigated the persistence of eight herbicides commonly detected in the GBR or its catchments in standard OECD simulation flask experiments, but with the aim to mimic natural conditions similar to those found on the GBR (i.e., relatively low herbicide concentrations, typical temperatures, light and microbial communities. Very little degradation was recorded over the standard 60 d period (Experiment 1 so a second experiment was extended to 365 d. Half-lives of PSII herbicides ametryn, atrazine, diuron, hexazinone and tebuthiuron were consistently greater than a year, indicating high persistence. The detection of atrazine and diuron metabolites and longer persistence in mercuric chloride-treated seawater confirmed that biodegradation contributed to the breakdown of herbicides. The shortest half-life recorded was 88 d for growth-regulating herbicide 2,4-D at 31°C in the dark, while the fatty acid-inhibitor metolachlor exhibited a minimum half-life of 281 d. The presence of moderate light and elevated temperatures affected the persistence of most of the herbicides; however, the scale and direction of the differences were not predictable and were likely due to changes in microbial community composition. The persistence estimates here represent some of the first appropriate data for application in risk assessments for herbicide exposure in tropical marine systems. The long persistence of herbicides identified in the present study helps explain detection of herbicides in nearshore waters of the GBR year round. Little degradation of these herbicides would be expected during the wet season with runoff and associated

  18. Energy balance for uranium recovery from seawater

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, E.; Lindner, H. [The University of Texas, 1 University Station C2200, Austin, TX 78712 (United States)

    2013-07-01

    The energy return on investment (EROI) of an energy resource is the ratio of the energy it ultimately produces to the energy used to recover it. EROI is a key viability measure for a new recovery technology, particularly in its early stages of development when financial cost assessment would be premature or highly uncertain. This paper estimates the EROI of uranium recovery from seawater via a braid adsorbent technology. In this paper, the energy cost of obtaining uranium from seawater is assessed by breaking the production chain into three processes: adsorbent production, adsorbent deployment and mooring, and uranium elution and purification. Both direct and embodied energy inputs are considered. Direct energy is the energy used by the processes themselves, while embodied energy is used to fabricate their material, equipment or chemical inputs. If the uranium is used in a once-through fuel cycle, the braid adsorbent technology EROI ranges from 12 to 27, depending on still-uncertain performance and system design parameters. It is highly sensitive to the adsorbent capacity in grams of U captured per kg of adsorbent as well as to potential economies in chemical use. This compares to an EROI of ca. 300 for contemporary terrestrial mining. It is important to note that these figures only consider the mineral extraction step in the fuel cycle. At a reference performance level of 2.76 g U recovered per kg adsorbent immersed, the largest energy consumers are the chemicals used in adsorbent production (63%), anchor chain mooring system fabrication and operations (17%), and unit processes in the adsorbent production step (12%). (authors)

  19. Herbicide Persistence in Seawater Simulation Experiments

    Science.gov (United States)

    Mercurio, Philip; Mueller, Jochen F.; Eaglesham, Geoff; Flores, Florita; Negri, Andrew P.

    2015-01-01

    Herbicides are detected year-round in marine waters, including those of the World Heritage listed Great Barrier Reef (GBR). The few previous studies that have investigated herbicide persistence in seawater generally reported half-lives in the order of months, and several studies were too short to detect significant degradation. Here we investigated the persistence of eight herbicides commonly detected in the GBR or its catchments in standard OECD simulation flask experiments, but with the aim to mimic natural conditions similar to those found on the GBR (i.e., relatively low herbicide concentrations, typical temperatures, light and microbial communities). Very little degradation was recorded over the standard 60 d period (Experiment 1) so a second experiment was extended to 365 d. Half-lives of PSII herbicides ametryn, atrazine, diuron, hexazinone and tebuthiuron were consistently greater than a year, indicating high persistence. The detection of atrazine and diuron metabolites and longer persistence in mercuric chloride-treated seawater confirmed that biodegradation contributed to the breakdown of herbicides. The shortest half-life recorded was 88 d for growth-regulating herbicide 2,4-D at 31°C in the dark, while the fatty acid-inhibitor metolachlor exhibited a minimum half-life of 281 d. The presence of moderate light and elevated temperatures affected the persistence of most of the herbicides; however, the scale and direction of the differences were not predictable and were likely due to changes in microbial community composition. The persistence estimates here represent some of the first appropriate data for application in risk assessments for herbicide exposure in tropical marine systems. The long persistence of herbicides identified in the present study helps explain detection of herbicides in nearshore waters of the GBR year round. Little degradation of these herbicides would be expected during the wet season with runoff and associated flood plumes

  20. Physico-chemical behavior of radionuclides in seawater

    International Nuclear Information System (INIS)

    Kimura, Yuichiro; Ogawa, Yoshihiro; Honda, Yoshihide; Katsurayama, Kosuke.

    1980-01-01

    To elucidate the physico-chemical states of radionuclides in seawater in relation to uptake by the marine biosphere, the physicochemical behavior of radiocobalt, radioruthenium and radiocerium in seawater was investigated by electrodialysis, high-voltage paper electrophoresis, and also by paper chromatography for nitrosylruthenium complexes. Most of the radiocobalt in seawater behaved as dialytic cations. However, these cationic species were not necessarily simple divalent, because their electrophoretic bands were rather diffuse and showed two peaks temporarily. The electroneutral form also increased with aging in seawater. The radioruthenium in seawater showed relatively a number of well-defined species which could be readily classified into anionic, cationic, electroneutral, colloidal or particulate, non-dialytic and more or less adsorbable species. The radioruthenium in the chloro and nitratonitrosylruthenium complexes occurred mainly electroneutral and anionic species, while nitro and binuclear oxygen-bridged nitratonitrosylruthenium complexes showed dominant anionic species. The hydrolysis of higher nitro and nitratonitrosylruthenium complexes to lower ones was demonstrated with aging in seawater by paper chromatography. The radiocerium in seawater showed initially cationic species. However, the electroneutral and anionic species were revealed with aging by electrodialysis. The radiocerium were strongly adsorbed on filter paper at the starting band in paper electrophoresis, presumably because of the formation of strongly adsorbable or insoluble hydrolytic species or particle formation. (author)

  1. Uranium from Seawater Program Review; Fuel Resources Uranium from Seawater Program DOE Office of Nuclear Energy

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-07-01

    For nuclear energy to remain sustainable in the United States, economically viable sources of uranium beyond terrestrial ores must be developed. The goal of this program is to develop advanced adsorbents that can extract uranium from seawater at twice the capacity of the best adsorbent developed by researchers at the Japan Atomic Energy Agency (JAEA), 1.5 mg U/g adsorbent. A multidisciplinary team from Oak Ridge National Laboratory, Lawrence Berkeley National Laboratory, Pacific Northwest National Laboratory, and the University of Texas at Austin was assembled to address this challenging problem. Polymeric adsorbents, based on the radiation grafting of acrylonitrile and methacrylic acid onto high surface-area polyethylene fibers followed by conversion of the nitriles to amidoximes, have been developed. These poly(acrylamidoxime-co-methacrylic acid) fibers showed uranium adsorption capacities for the extraction of uranium from seawater that exceed 3 mg U/g adsorbent in testing at the Pacific Northwest National Laboratory Marine Sciences Laboratory. The essence of this novel technology lies in the unique high surface-area trunk material that considerably increases the grafting yield of functional groups without compromising its mechanical properties. This technology received an R&D100 Award in 2012. In addition, high surface area nanomaterial adsorbents are under development with the goal of increasing uranium adsorption capacity by taking advantage of the high surface areas and tunable porosity of carbon-based nanomaterials. Simultaneously, de novo structure-based computational design methods are being used to design more selective and stable ligands and the most promising candidates are being synthesized, tested and evaluated for incorporation onto a support matrix. Fundamental thermodynamic and kinetic studies are being carried out to improve the adsorption efficiency, the selectivity of uranium over other metals, and the stability of the adsorbents. Understanding

  2. Evaluation of durability of SSCs injected with seawater

    International Nuclear Information System (INIS)

    2012-01-01

    At the units 1 to 4 in the Fukushima Daiichi Nuclear Power Plant, seawater was injected into reactor pressure vessels and spent fuel pools in order to cool down nuclear fuel is after the disaster of the 2011 off the Pacific Coast of Tohoku Earthquake and Tsunami. Therefore, for fuel cladding tubes exposed to seawater and piping items to pour seawater into a nuclear reactor, it was necessary to evaluate structural integrity under the seawater environment. And then, JNES carried out the safety research of 'Evaluation of Durability of SSCs injected with Seawater' in FY2011. The contents and the results obtained from the search are as follows; (1) For the pipes and nuclear reactor containment vessels, corrosion tests under high temperature seawater at 50degC and 80degC were carried out for the carbon steel that corrosion resistance was less. The data of relationship between a dipping time upto 1,500h and a corrosion rate were obtained as parameters at chloride ion (CI - ) content and the temperature of the seawater. As the results, the corrosion rate was almost 0.1 mm/y for the carbon steel SGV480. No significant influence of CT - content and the temperature of the seawater was confirmed. (2) Corrosion tests were carried out to obtain the relations of time and corrosion under different CI - content conditions for the simulated fuel rod specimens in seawater at 90degC for durations upto 1,200h. As the results, very little corrosion was observed on Zry-2 cladding tube. Brown rust was slightly appeared on the nut made of stainless steel and the lower tie plate made of cast stainless steel. Thinning and corrosion pit were not observed. (author)

  3. Hydraulic conductivity of some bentonites in artificial seawater

    International Nuclear Information System (INIS)

    Komine, Hideo; Murakami, Satoshi; Yasuhara, Kazuya

    2011-01-01

    A high-level radioactive waste disposal facility might be built in a coastal area in Japan from the viewpoint of feasible transportation of waste. Therefore, it is important to investigate the effects of seawater on a bentonite-based buffer. This study investigated the influence of seawater on hydraulic conductivity of three common sodium-types of bentonite and one calcium-type bentonite by the laboratory experiments. >From the results of laboratory experiment, this study discussed the influence of seawater on hydraulic conductivity of bentonites from the viewpoints of kinds of bentonite such as exchangeable-cation type and montmorillonite content and dry density of bentonite-based buffer. (author)

  4. Determination of uranium in seawater by fluorescence spectrometry

    International Nuclear Information System (INIS)

    Kawashima, Toshi; Kawakubo, Senkichi; Minegishi, Hisako.

    1984-01-01

    A Fluorescence spectrometry for the determination of uranium in seawater has been developed. Anion exchange separation of uranium from seawater followed by preparation of NaF-carbonate cake and by spectrometry for ultraviolet ray excited fluorescence of uranium on the fluoride host provide the trace determinaton of uranium at the subnano gram level. Anion exchange behavior, excitation-emission behavior of the uranium on the host and effects of foreign ions to the fluorescence have been presented. Appling the method to 1 ml of seawater 3 ppb of uranium has been determined. (author)

  5. Numerical Study of Groundwater Flow and Salinity Distribution Cycling Controlled by Seawater/Freshwater Interaction in Karst Aquifer Using SEAWAT

    Science.gov (United States)

    Xu, Z.; Hu, B.

    2017-12-01

    The interest to predict seawater intrusion and salinity distribution in Woodville Karst Plain (WKP) has increased due to the huge challenge on quality of drinkable water and serious environmental problems. Seawater intrudes into the conduit system from submarine karst caves at Spring Creek Spring due to density difference and sea level rising, nowadays the low salinity has been detected at Wakulla Spring which is 18 km from coastal line. The groundwater discharge at two major springs and salinity distribution in this area is controlled by the seawater/freshwater interaction under different rainfall conditions: during low rainfall periods, seawater flow into the submarine spring through karst windows, then the salinity rising at the submarine spring leads to seawater further intrudes into conduit system; during high rainfall periods, seawater is pushed out by fresh water discharge at submarine spring. The previous numerical studies of WKP mainly focused on the density independent transport modeling and seawater/freshwater discharge at major karst springs, in this study, a SEAWAT model has been developed to fully investigate the salinity distribution in the WKP under repeating phases of low rainfall and high rainfall periods, the conduit system was simulated as porous media with high conductivity and porosity. The precipitation, salinity and discharge at springs were used to calibrate the model. The results showed that the salinity distribution in porous media and conduit system is controlled by the rainfall change, in general, the salinity distribution inland under low rainfall conditions is much higher and wider than the high rainfall conditions. The results propose a prediction on the environmental problem caused by seawater intrusion in karst coastal aquifer, in addition, provide a visual and scientific basis for future groundwater remediation.

  6. Strontium (Sr) separation from seawater using titanate adsorbents: Effects of seawater matrix ions on Sr sorption behavior

    Science.gov (United States)

    Ryu, Jungho; Hong, Hye-jin; Ryu, Taegong; Park, In-Su

    2017-04-01

    Strontium (Sr) which has many industrial applications such as ferrite magnet, ceramic, and fire works exists in seawater with the concentration of approximately 7 mg/L. In previous report estimating economic potential on recovery of various elements from seawater in terms of their commercial values and concentrations in seawater, Sr locates upper than approximate break-even line, which implies Sr recovery from seawater can be potentially profitable. Recently, Sr separation from seawater has received great attention in the environmental aspect after Fukushima Nuclear Power Plant (NPP) accident which released much amount of radioactive Sr and Cs. Accordingly, the efficient separation of radioactive elements released to seawater has become critical as an important technological need as well as their removal from radioactive wastes. So far, it has been introduced to separate Sr from aqueous media by various methods including solvent extraction, adsorption by solid materials, and ion exchange. Among them, the adsorption technique using solid adsorbents is of great interest for selectively separating Sr from seawater with respect to low concentration level of Sr. In this study, we synthesized titanate nanotube (TiNT) by simple hydrothermal reaction, characterized its physicochemical properties, and systematically evaluated Sr sorption behavior under various reaction conditions corresponding to seawater environment. The synthesized TiNT exhibited the fibril-type nanotube structure with high specific surface area of 260 m2/g. The adsorption of Sr on TiNT rapidly occurred following pseudo-second-order kinetic model, and was in good agreement with Langmuir isotherm model, indicating maximum adsorption capacity of 97 mg/g. Based on Sr uptake and Na release with stoichiometric balance, sorption mechanism of Sr on TiNT was found to be ion-exchange between Na in TiNT lattice and Sr in solution phase, which was also confirmed by XRD and Raman analysis. Among competitive ions, Ca

  7. Seawater State Variables in Hatchery and Raceway Tanks

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Ambient seawater temperature and salinity was recorded on an intermittent basis for comparison with adjusted temperatures used in the aquaculture of bivalves

  8. Effect of Groundwater Pumping on Seawater Intrusion in Coastal Aquifers

    Directory of Open Access Journals (Sweden)

    M.M. Sherif

    2002-06-01

    Full Text Available Many aquifers around the globe are located in coastal areas and are thus subjected to the seawater intrusion phenomenon. The growth of population in coastal areas and the conjugate increase in human, agricultural, and industrial activities have imposed an increasing demand for freshwater. This increase in water demand is often covered by extensive pumping of fresh groundwater, causing subsequent lowering of the water table (or piezometric head and upsetting the dynamic balance between freshwater and saline water bodies. The classical result of such a development is seawater intrusion. This paper presents a review for the seawater intrusion phenomenon in coastal aquifers. The effect of pumping activities on the seawater intrusion in the Nile Delta aquifer of Egypt is investigated. It was concluded that any additional pumping should be located in the middle Delta and avoided in the eastern and western sides of the Delta.

  9. Reasons for the Fast Growing Seawater Desalination Capacity in Algeria

    KAUST Repository

    Drouiche, Nadjib; Ghaffour, NorEddine; Naceur, Mohamed Wahib; Mahmoudi, Hacè ne; Ouslimane, Tarik

    2011-01-01

    growing markets. Five desalination plants, including the Africa's largest seawater reverse osmosis project with a total capacity of 200,000 m3 per day, are already in operation and the remaining projects are either under construction or in commissioning

  10. Ionic potential as a controller of seawater composition

    Digital Repository Service at National Institute of Oceanography (India)

    DileepKumar, M.

    depend on IP inversely but L2, L3, siderophilic and chalcophilic elements exhibit positive linear relationships with respect to seawater-crustal rock partition coefficients. The mean oceanic residence times of L1 elements show negative relationship...

  11. Latent Toxicity of Endothall to Anadromous Salmonids During Seawater Challenge.

    Science.gov (United States)

    Courter, Lauren A; Garrison, Thomas M; Courter, Ian I

    2016-05-01

    Limited evidence exists on the latent effects of toxicant exposure on the seawater adaptability of anadromous salmon and steelhead. It is unclear whether such an effect exists for the widely used and relatively non-toxic herbicide endothall. Coho salmon, Oncorhynchus kisutch (coho), Chinook salmon, O. tshawytscha (Chinook), and anadromous rainbow trout, O. mykiss (steelhead) were subjected to a 10-day seawater challenge following freshwater treatments [0-12 mg acid equivalent (a.e)./L at 96 h]. Mean survival resulted in 82 % (n = 225), 84 % (n = 133), 90 % (n = 73) and 59 % (n = 147) survival for 0, 3-5, 6-8, and 9-12 mg a.e./L, respectively. Our results indicate a lower toxicity threshold compared with previously reported acute toxicity results, but higher compared with previous seawater challenge studies. We demonstrate the utility of the seawater challenge assay to accurately define toxic effects of pesticides on salmonids with complex life-histories.

  12. An Evaluation of Carbon Steel Corrosion Under Stagnant Seawater Conditions

    National Research Council Canada - National Science Library

    Lee, Jason

    2004-01-01

    Corrosion, of 1020 carbon steel coupons in, natural seawater over a six-month period was more aggressive under stagnant anaerobic conditions than stagnant aerobic conditions as measured by weight loss...

  13. Speciation and spectrophotometric determination of uranium in seawater

    Directory of Open Access Journals (Sweden)

    M. KONSTANTINOU

    2004-06-01

    Full Text Available A series of ion-exchange and extraction procedures for the separation of uranium from seawater samples and subsequent spectrophotometric determination of uranium in seawater by means of arsenazo(III is described. According to the measurements performed by means of traced samples at every stage of separation, the yield of the pre-analytical procedures is generally over 90% and the separation of uranium very selective. The mean uranium concentration in seawater samples collected from five different coastal areas in Cyprus was found to be 3.2 ± 0.2 & micro; g L-1. Uranium in seawater is stable in its hexavalent oxidation state and UO2 (CO334- is the predominant species under normal coastal conditions (pH ≥ 8, EH ≥ 0.35 mV, 1 atm and 0.03% CO2.

  14. Uptake of elements from seawater by ferromanganese crusts: Solid-phase associations and seawater speciation

    Science.gov (United States)

    Koschinsky, A.; Hein, J.R.

    2003-01-01

    Marine Fe-Mn oxyhydroxide crusts form by precipitation of dissolved components from seawater. Three hydrogenetic crust samples (one phosphatized) and two hydrothermal Mn-oxide samples were subjected to a sequential-leaching procedure in order to determine the host phases of 40 elements. Those host-phase associations are discussed with respect to element speciation in seawater. The partitioning of elements between the two major phases, Mn oxide and Fe oxyhydroxide, can in a first-order approximation be explained by a simple sorption model related to the inorganic speciation of the elements in seawater, as has been proposed in earlier models. Free and weakly complexed cations, such as alkali and alkaline earth metals, Mn, Co, Ni, Zn, T1(I), and partly Y, are sorbed preferentially on the negatively charged surface of the MnO2 in hydrogenetic crusts. The driving force is a strong coulombic interaction. All neutral or negatively charged chloro (Cd, Hg, T1), carbonate (Cu, Y, Pb, and U), and hydroxide (Be, Sc, Ti, Fe, Zr, Nb, In, Sn, Sb, Te, Hf, Ta, Bi, Th, and T1(III)) complexes and oxyanions (V, Cr, As, Se, Mo, and W) bind to the slightly positively charged surface of the amorphous FeOOH phase. While coulombic interaction can explain the sorption of the negatively charged species, the binding of neutral species is based on specific chemical interaction. Organic complexation of elements in deep-ocean water seems to be at most of minor importance. Surface oxidation can explain some strong metal associations, e.g. of Co and T1 with the MnO2 and Te with the FeOOH. Sorption reactions initially driven by coulombic forces are often followed by the formation of specific bonds between the adsorbate and the atoms of the oxide surface. Differences in the associations of some metals between the non-phosphatized and phosphatized hydrogenetic crusts and between the hydrogenetic and the hydrothermal samples reflect the different physico-chemical environments of formation and

  15. Calcium extraction from brine water and seawater using oxalic acid

    Science.gov (United States)

    Natasha, Nadia Chrisayu; Lalasari, Latifa Hanum

    2017-01-01

    Calcium can be extracted not only from rocks but also from natural liquor such as seawater and brine water. In order to extract the calcium from seawater and brine water, oxalic acid was used in this research. Effect of variations of the volume of the oxalic acid at a constant concentration in seawater and brine water to produce calcium was investigated. The concentration of oxalic acid was 100 g/l and the variations of its volume were 2 ml, 4 ml, 6 ml, 8 ml, 10 ml, 20 ml, 30 ml, 40 ml, and 50 ml. The used seawater and brine water were firstly evaporated from 100 ml into 50 ml and then the oxalic acid was added into them with mixing to produce the calcium precipitates. The precipitates were analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM) and the filtrates were analyzed by inductively coupled plasma-optical emission spectrometry (ICP-OES). The SEM analysis showed that the precipitates from brine water were consisted of only calcium compound while from seawater sodium one was also found along with calcium compound. The XRD analysis showed that the calcium was present in the form of calcium oxalate for both seawater and brine water. The ICP-OES analysis of the filtrate from seawater precipitation showed that the its calcium content was decreased from 826.20 ppm to 0.04 ppm while from brine water, it decreased from 170.06 ppm to 1.96 ppm. These results showed that both seawater and brine water have the potential to be a raw material for calcium production.

  16. Influence of seawater intrusion on microbial communities in groundwater.

    Science.gov (United States)

    Unno, Tatsuya; Kim, Jungman; Kim, Yumi; Nguyen, Son G; Guevarra, Robin B; Kim, Gee Pyo; Lee, Ji-Hoon; Sadowsky, Michael J

    2015-11-01

    Groundwater is the sole source of potable water on Jeju Island in the Republic of (South) Korea. Groundwater is also used for irrigation and industrial purposes, and it is severely impacted by seawater intrusion in coastal areas. Consequently, monitoring the intrusion of seawater into groundwater on Jeju is very important for health and environmental reasons. A number of studies have used hydrological models to predict the deterioration of groundwater quality caused by seawater intrusion. However, there is conflicting evidence of intrusion due to complicated environmental influences on groundwater quality. Here we investigated the use of next generation sequencing (NGS)-based microbial community analysis as a way to monitor groundwater quality and detect seawater intrusion. Pristine groundwater, groundwater from three coastal areas, and seawater were compared. Analysis of the distribution of bacterial species clearly indicated that the high and low salinity groundwater differed significantly with respect to microbial composition. While members of the family Parvularculaceae were only identified in high salinity water samples, a greater percentage of the phylum Actinobacteria was predominantly observed in pristine groundwater. In addition, we identified 48 shared operational taxonomic units (OTUs) with seawater, among which the high salinity groundwater sample shared a greater number of bacterial species with seawater (6.7%). In contrast, other groundwater samples shared less than 0.5%. Our results suggest that NGS-based microbial community analysis of groundwater may be a useful tool for monitoring groundwater quality and detect seawater intrusion. This technology may also provide additional insights in understanding hydrological dynamics. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Biomass production of Tetraselmis suecica using seawater with sanguaza

    Directory of Open Access Journals (Sweden)

    Juan Silva B.

    2011-03-01

    Full Text Available The growth of Tetraselmis suecica was evaluated. The experiment was realized using the Response Surface Methodology (RSM with Central Composite Rotational Design (CCRD with two factors, pH and sanguaza/seawater concentration in the range of 7 - 9 and 2 - 5 % (v/v, respectively. The culture media were stirred by bubbling air constantly (0.07 L/s and continuously illuminated with 40 W of fluorescent light in glass containers of 1.5 L capacity at a temperature of 22.5 ± 2.1 °C. Using the Gompertz mathematical model was determined that from an 8.0 of pH and a ratio of 3.5% of sanguaza/seawater, the Tetraselmis suecica achieves maximum growth. An 8.71 of pH and a ratio of 4.56% of sanguaza/seawater allow the Tetraselmis suecica maximum growth (logN/N0 of 0.659, with a 12.3% of prediction error by applying a mathematical model of 2nd order. According to the study, the values obtained in sanguaza/seawater as a culture medium outperformed the traditionally used culture medium (Guillard F/2 with seawater. The results demonstrate the potential use of the sanguaza/seawater medium in scalable studies on pilot scale production of Tetraselmis suecica, with a view to the production of biodiesel

  18. Status of technology of uranium recovery from seawater

    International Nuclear Information System (INIS)

    Sugo, Takanobu; Saito, Kyoichi.

    1990-01-01

    By bringing the solid material called adsorbent in contact with seawater, uranium can be collected, therefore, the adsorbent to which uranium was adsorbed in seawater can be regarded as the resource of uranium storing. To the adsorbent, also rare metals are concentrated in addition to uranium. From such viewpoint, the development of the technology for collecting seawater uranium is important for the Japanese energy policy. The uranium concentration in seawater is about 3 mg/m 3 and its form of dissolution is uranyl tricarbonate ions. The technology of collecting seawater uranium is the separation technology for extracting the component of very low concentration from the aqueous solution containing many components. The total amount of uranium in the whole oceans reaches about 4 billion t, which is about 1000 times as much as the uranium commercially mined on land. It is the target of the technology to make artificial uranium ore of as high quality as possible quickly. The process of collecting seawater uranium comprises adsorption, desorption, separation and enrichment. As the adsorbents, hydrated titanium oxide and chelate resin represented by amidoxime are promising. The adsorption system is described. (K.I.)

  19. Development of adsorbents for recovery of uranium from seawater

    International Nuclear Information System (INIS)

    Egawa, Hiroaki; Furusaki, Shintaro.

    1987-01-01

    The largest subject for putting the extraction of uranium from seawater in practical use is the development of high performance adsorbents for uranium. In this paper, the way of thinking about the development of adsorbents for extracting uranium from seawater and the recent reports on this subject are described. Next, the research on the adsorbing capacity and adsorbing rate of the adsorbents developed so far is summarized, and the way of thinking about the evaluation of adsorbent performance which is the base of the design of a system for extracting uranium from seawater is explained, taking amidoxime type adsorbent as the example. For Japan where energy resources are scant, the uranium contained in seawater, which is estimated to be about 4.2 billion t, is the most luring important element. Uranium is contained in seawater is very low concentration of 3 ppb, and exists as anion complex salt. In 1960s, the Harwell Atomic Energy Research Establishment in UK found out that titanium oxide hydrate is the most promising as the adsorbent. Also a number of organic absorbents have been developed. In order to bring adsorbents in contact with seawater, pumping, ocean current and wave force are utilized. Adsorbents are in spherical, fiber and film forms, and held as fixed beds and fluidized beds. (Kako, I.) 48 refs

  20. Improvement of seawater booster pump outlet check valve

    International Nuclear Information System (INIS)

    Li Xuning; Du Yansong; Huang Huimin

    2010-01-01

    Conventional island seawater booster pump set of QNPC 310 MWe unit are very important in the whole circulating cooling system, and the integrate function of seawater booster pump outlet check valve is the foundation of steady operation of the seawater booster pump set. The article mainly introduce that through the analyses to the reason to the problem that the seawater booster pump outlet check valve of QNPC 310 MWe unit appeared in past years by our team, and considering the influence of operation condition and circumstance, the team improve the seawater booster pump outlet check valve from swing check valve to shuttle check valve which operate more appropriately in the system. By the test of continuous practice, we make further modification to the inner structure of shuttle check valve contrapuntally, and therefore we solve the problem in seawater booster pump outlet check valve fundamentally which has troubled the security of system operation in past years, so we realize the aim of technical improvement and ensure that the system operate in safety and stability. (authors)

  1. Effects of dissolved species on radiolysis of diluted seawater

    International Nuclear Information System (INIS)

    Hata, Kuniki; Hanawa, Satoshi; Kasahara, Shigeki; Motooka, Takafumi; Tsukada, Takashi; Muroya, Yusa; Yamashita, Shinichi; Katsumura, Yosuke

    2014-01-01

    Fukushima Daiichi Nuclear Power Plants (NPPs) experienced seawater injection into the cores and fuel pools as an emergent measure after the accident. After the accident, retained water has been continuously desalinized, and subsequently the concentration of chloride ion (Cl"-) has been kept at a lower level these days. These ions in seawater are known to affect water radiolysis, which causes the production of radiolytic products, such as hydrogen peroxide (H_2O_2), molecular hydrogen (H_2) and molecular oxygen (O_2). However, the effects of dissolved ions relating seawater on the production of the stable radiolytic products are not well understood in the diluted seawater. To understand of the production behavior in diluted seawater under radiation, radiolysis calculations were carried out. Production of H_2 is effectively suppressed by diluting by up to vol10%. The concentrations of oxidants (H_2O_2 and O_2) are also suppressed by dilution of dissolved species. The effect of oxidants on corrosion of materials is thought to be low when the seawater was diluted by less than 1 vol% by water. It is also shown that deaeration is one of the effective measure to suppress the concentrations of oxidants at a lower level for any dilution conditions. (author)

  2. Comment on: 'The strontium isotopic composition of seawater and seawater-oceanic crust interaction' by E.T.C. Spooner

    International Nuclear Information System (INIS)

    Brass, G.W.; Turekian, K.L.

    1977-01-01

    Various processes have been proposed as the source of strontium to the oceans but there is no evidence to support the mechanism of release of relatively unradiogenic strontium from deep dea basalts to sea-water. (B.D.)

  3. Desalination of Seawater using Nuclear Energy

    International Nuclear Information System (INIS)

    Misra, B.M.

    2006-01-01

    Desalination technologies have been well established since the mid 20th century and are widely deployed in many parts of the world having acute water scarcity problems. The energy for these plants is generally supplied in the form of either steam or electricity largely using fossil fuels. The intensive fuels of fossil fuels raises environmental concerns especially in relation to greenhouse gas emissions. The depleting sources and future price uncertainty of the fossil fuels and their better use for other vital industrial applications is also a factor to be considered for sustainability. The desalination of sea water using nuclear energy is a feasible option to meet the growing demand of potable water. Over 150 reactor-years of operating experience of a nuclear desalination have been accumulated worldwide. Several demonstration programs of nuclear desalination are also in progress to confirm its technical and economic viability under country specific conditions, with the technical coordination or support of IAEA. Recent techno-economic feasibility studies carried out by some Member States indicate the competitiveness of nuclear desalination. This paper presents the salient activities on nuclear desalination in the Agency and in the interested Member states. Economic research on further water cost reduction includes investigation on utilization of waste heat from different reactor types for thermal desalination pre-heat reverse osmosis and hybrid desalination systems. The main challenge for the large scale deployment of nuclear seawater desalination is the lack of infrastructure and the resources in the countries affected by water scarcity problems which are however, interested in adoption of nuclear desalination for the sustainable water resources. Socio-economic and environmental aspects and the public perception are also important factors requiring greater information exchange. (author)

  4. Influence of glacial meltwater on global seawater δ234U

    Science.gov (United States)

    Arendt, Carli A.; Aciego, Sarah M.; Sims, Kenneth W. W.; Das, Sarah B.; Sheik, Cody; Stevenson, Emily I.

    2018-03-01

    We present the first published uranium-series measurements from modern Greenland Ice Sheet (GrIS) runoff and proximal seawater, and investigate the influence of glacial melt on global seawater δ234U over glacial-interglacial (g-ig) timescales. Climate reconstructions based on closed-system uranium-thorium (U/Th) dating of fossil corals assume U chemistry of seawater has remained stable over time despite notable fluctuations in major elemental compositions, concentrations, and isotopic compositions of global seawater on g-ig timescales. Deglacial processes increase weathering, significantly increasing U-series concentrations and changing the δ234U of glacial meltwater. Analyses of glacial discharge from GrIS outlet glaciers indicate that meltwater runoff has elevated U concentrations and differing 222Rn concentrations and δ234U compositions, likely due to variations in subglacial residence time. Locations with high δ234U have the potential to increase proximal seawater δ234U. To better understand the impact of bulk glacial melt on global seawater δ234U over time, we use a simple box model to scale these processes to periods of extreme deglaciation. We account for U fluxes from the GrIS, Antarctica, and large Northern Hemisphere Continental Ice Sheets, and assess sensitivity by varying melt volumes, duration and U flux input rates based on modern subglacial water U concentrations and compositions. All scenarios support the hypothesis that global seawater δ234U has varied by more than 1‰ through time as a function of predictable perturbations in continental U fluxes during g-ig periods.

  5. Estimates of ikaite export from sea ice to the underlying seawater in a sea ice-seawater mesocosm

    Science.gov (United States)

    Geilfus, Nicolas-Xavier; Galley, Ryan J.; Else, Brent G. T.; Campbell, Karley; Papakyriakou, Tim; Crabeck, Odile; Lemes, Marcos; Delille, Bruno; Rysgaard, Søren

    2016-09-01

    The precipitation of ikaite and its fate within sea ice is still poorly understood. We quantify temporal inorganic carbon dynamics in sea ice from initial formation to its melt in a sea ice-seawater mesocosm pool from 11 to 29 January 2013. Based on measurements of total alkalinity (TA) and total dissolved inorganic carbon (TCO2), the main processes affecting inorganic carbon dynamics within sea ice were ikaite precipitation and CO2 exchange with the atmosphere. In the underlying seawater, the dissolution of ikaite was the main process affecting inorganic carbon dynamics. Sea ice acted as an active layer, releasing CO2 to the atmosphere during the growth phase, taking up CO2 as it melted and exporting both ikaite and TCO2 into the underlying seawater during the whole experiment. Ikaite precipitation of up to 167 µmol kg-1 within sea ice was estimated, while its export and dissolution into the underlying seawater was responsible for a TA increase of 64-66 µmol kg-1 in the water column. The export of TCO2 from sea ice to the water column increased the underlying seawater TCO2 by 43.5 µmol kg-1, suggesting that almost all of the TCO2 that left the sea ice was exported to the underlying seawater. The export of ikaite from the ice to the underlying seawater was associated with brine rejection during sea ice growth, increased vertical connectivity in sea ice due to the upward percolation of seawater and meltwater flushing during sea ice melt. Based on the change in TA in the water column around the onset of sea ice melt, more than half of the total ikaite precipitated in the ice during sea ice growth was still contained in the ice when the sea ice began to melt. Ikaite crystal dissolution in the water column kept the seawater pCO2 undersaturated with respect to the atmosphere in spite of increased salinity, TA and TCO2 associated with sea ice growth. Results indicate that ikaite export from sea ice and its dissolution in the underlying seawater can potentially hamper

  6. Boron Removal in Seawater Reverse Osmosis System

    KAUST Repository

    Rahmawati, Karina

    2011-07-01

    Reverse osmosis successfully proves to remove more than 99% of solute in seawater, providing fresh water supply with satisfied quality. Due to some operational constraints, however, some trace contaminants removal, such as boron, cannot be achieved in one pass system. The stringent criterion for boron from World Health Organization (WHO) and Saudi Arabia local standard (0.5 mg/l) is hardly fulfilled by single pass sea water reverse osmosis (SWRO) plants. Some design processes have been proposed to deal with boron removal, but they are not economically efficient due to high energy and chemical consumption. The objective of this study was to study boron removal by different reverse osmosis membranes in two pH conditions, with and without antiscalant addition. Thus, it was expected to observe the possibility of operating single pass system and necessity to operate two pass system using low energy membrane. Five membrane samples were obtained from two different manufacturers. Three types of feed water pH were used, pH 8, pH 10, and pH 10 with antiscalant addition. Experiment was conducted in parallel to compare membrane performance from two manufacturers. Filtration was run with fully recycle mode for three days. Sample of permeate and feed were taken every 12 hours, and analyzed for their boron and TDS concentration. Membrane samples were also tested for their surface charge. The results showed that boron rejection increases as the feed pH increases. This was caused by dissociation of boric acid to negatively charged borate ion and more negatively charged membrane surface at elevated pH which enhance boron rejection. This study found that single pass reverse osmosis system, with and without elevating the pH, may not be possible to be applied because of two reasons. First, permeate quality in term of boron, does not fulfill WHO and local Saudi Arabia regulations. Second, severe scaling occurs due to operation in alkaline condition, since Ca and Mg concentration are

  7. Comparison of techniques for pre-concentrating radium from seawater

    International Nuclear Information System (INIS)

    Bourquin, M.; Van Beek, P.; Souhaut, M.; Jeandel, C.; Reyss, J.L.; Charette, M.A.

    2008-01-01

    In the framework of the KEOPS project (Kerguelen: compared study of the Ocean and the Plateau in Surface water), we aimed to provide information on the water mass pathways and vertical mixing on the Kerguelen Plateau, Southern Ocean, based on 228 Ra profiles. Because 228 Ra activities are extremely low in this area (∼ 0.1 dpm/100 kg or ∼ 2.10 -18 g kg -1 ), the filtration of large volumes of seawater was required in order to be able to detect it with minimal uncertainty. This challenging study was an opportunity for us to test and compare methods aimed at removing efficiently radium isotopes from seawater. We used Mn-fiber that retains radium and that allows the measurement of all four radium isotopes ( 226 Ra, 228 Ra, 223 Ra, 224 Ra). First, we used Niskin bottles or the ship's seawater intake to collect large volumes of seawater that were passed onto Mn-fiber in the laboratory. Second, we filled cartridges with Mn-fiber that we placed in tandem on in situ pumps. Finally, we fixed nylon nets filled with Mn-fiber on the frame of in situ pumps to allow the passive filtration of seawater during the pump deployment. Yields of radium fixation on the cartridges filled with Mn-fiber and placed on in situ pumps are ca. 30% when combining the two cartridges. Because large volumes of seawater can be filtered with these pumps, this yields to effective volumes of 177-280 kg (that is, higher than that recovered from fourteen 12-1 Niskin bottles). Finally, the effective volume of seawater that passed through Mn-fiber placed in nylon nets and deployed during 4 h ranged between 125 and 364 kg. Consequently, the two techniques that separate Ra isotopes in situ are good alternatives for pre-concentrating radium from seawater. They can save ship-time by avoiding repeated CTD casts to obtain the large volumes of seawater. This is especially true when in situ pumps are deployed to collect suspended particles. However, both methods only provide 228 Ra/ 226 Ra ratios. The

  8. Non‐diluted seawater enhances nasal ciliary beat frequency and wound repair speed compared to diluted seawater and normal saline

    Science.gov (United States)

    Bonnomet, Arnaud; Luczka, Emilie; Coraux, Christelle

    2016-01-01

    Background The regulation of mucociliary clearance is a key part of the defense mechanisms developed by the airway epithelium. If a high aggregate quality of evidence shows the clinical effectiveness of nasal irrigation, there is a lack of studies showing the intrinsic role of the different irrigation solutions allowing such results. This study investigated the impact of solutions with different pH and ionic compositions, eg, normal saline, non‐diluted seawater and diluted seawater, on nasal mucosa functional parameters. Methods For this randomized, controlled, blinded, in vitro study, we used airway epithelial cells obtained from 13 nasal polyps explants to measure ciliary beat frequency (CBF) and epithelial wound repair speed (WRS) in response to 3 isotonic nasal irrigation solutions: (1) normal saline 0.9%; (2) non‐diluted seawater (Physiomer®); and (3) 30% diluted seawater (Stérimar). The results were compared to control (cell culture medium). Results Non‐diluted seawater enhanced the CBF and the WRS when compared to diluted seawater and to normal saline. When compared to the control, it significantly enhanced CBF and slightly, though nonsignificantly, improved the WRS. Interestingly, normal saline markedly reduced the number of epithelial cells and ciliated cells when compared to the control condition. Conclusion Our results suggest that the physicochemical features of the nasal wash solution is important because it determines the optimal conditions to enhance CBF and epithelial WRS thus preserving the respiratory mucosa in pathological conditions. Non‐diluted seawater obtains the best results on CBF and WRS vs normal saline showing a deleterious effect on epithelial cell function. PMID:27101776

  9. Non-diluted seawater enhances nasal ciliary beat frequency and wound repair speed compared to diluted seawater and normal saline.

    Science.gov (United States)

    Bonnomet, Arnaud; Luczka, Emilie; Coraux, Christelle; de Gabory, Ludovic

    2016-10-01

    The regulation of mucociliary clearance is a key part of the defense mechanisms developed by the airway epithelium. If a high aggregate quality of evidence shows the clinical effectiveness of nasal irrigation, there is a lack of studies showing the intrinsic role of the different irrigation solutions allowing such results. This study investigated the impact of solutions with different pH and ionic compositions, eg, normal saline, non-diluted seawater and diluted seawater, on nasal mucosa functional parameters. For this randomized, controlled, blinded, in vitro study, we used airway epithelial cells obtained from 13 nasal polyps explants to measure ciliary beat frequency (CBF) and epithelial wound repair speed (WRS) in response to 3 isotonic nasal irrigation solutions: (1) normal saline 0.9%; (2) non-diluted seawater (Physiomer®); and (3) 30% diluted seawater (Stérimar). The results were compared to control (cell culture medium). Non-diluted seawater enhanced the CBF and the WRS when compared to diluted seawater and to normal saline. When compared to the control, it significantly enhanced CBF and slightly, though nonsignificantly, improved the WRS. Interestingly, normal saline markedly reduced the number of epithelial cells and ciliated cells when compared to the control condition. Our results suggest that the physicochemical features of the nasal wash solution is important because it determines the optimal conditions to enhance CBF and epithelial WRS thus preserving the respiratory mucosa in pathological conditions. Non-diluted seawater obtains the best results on CBF and WRS vs normal saline showing a deleterious effect on epithelial cell function. © 2016 The Authors International Forum of Allergy & Rhinology, published by ARSAAOA, LLC.

  10. XAS and TRLIF spectroscopy of uranium and neptunium in seawater.

    Science.gov (United States)

    Maloubier, Melody; Solari, Pier Lorenzo; Moisy, Philippe; Monfort, Marguerite; Den Auwer, Christophe; Moulin, Christophe

    2015-03-28

    Seawater contains radionuclides at environmental levels; some are naturally present and others come from anthropogenic nuclear activity. In this report, the molecular speciation in seawater of uranium(VI) and neptunium(V) at a concentration of 5 × 10(-5) M has been investigated for the first time using a combination of two spectroscopic techniques: Time-resolved laser-induced fluorescence (TRLIF) for U and extended X-ray absorption fine structure (EXAFS) for U and Np at the LIII edge. In parallel, the theoretical speciation of uranium and neptunium in seawater at the same concentration is also discussed and compared to spectroscopic data. The uranium complex was identified as the neutral carbonato calcic complex UO2(CO3)3Ca2, which has been previously described in other natural systems. In the case of neptunium, the complex identified is mainly a carbonato complex whose exact stoichiometry is more difficult to assess. The knowledge of the actinide molecular speciation and reactivity in seawater is of fundamental interest in the particular case of uranium recovery and more generally regarding the actinide life cycle within the biosphere in the case of accidental release. This is the first report of actinide direct speciation in seawater medium that can complement inventory data.

  11. Seawater-cultured Botryococcus braunii for efficient hydrocarbon extraction.

    Directory of Open Access Journals (Sweden)

    Kenichi Furuhashi

    Full Text Available As a potential source of biofuel, the green colonial microalga Botryococcus braunii produces large amounts of hydrocarbons that are accumulated in the extracellular matrix. Generally, pretreatment such as drying or heating of wet algae is needed for sufficient recoveries of hydrocarbons from B. braunii using organic solvents. In this study, the Showa strain of B. braunii was cultured in media derived from the modified Chu13 medium by supplying artificial seawater, natural seawater, or NaCl. After a certain period of culture in the media with an osmotic pressure corresponding to 1/4-seawater, hydrocarbon recovery rates exceeding 90% were obtained by simply mixing intact wet algae with n-hexane without any pretreatments and the results using the present culture conditions indicate the potential for hydrocarbon milking.Seawater was used for efficient hydrocarbon extraction from Botryococcus braunii. The alga was cultured in media prepared with seawater or NaCl. Hydrocarbon recovery rate exceeding 90% was obtained without any pretreatment.

  12. Seawater calcium isotope ratios across the Eocene-Oligocene transition

    Science.gov (United States)

    Griffith, E.M.; Paytan, A.; Eisenhauer, A.; Bullen, T.D.; Thomas, E.

    2011-01-01

    During the Eocene-Oligocene transition (EOT, ca. 34 Ma), Earth's climate cooled significantly from a greenhouse to an icehouse climate, while the calcite (CaCO3) compensation depth (CCD) in the Pacific Ocean increased rapidly. Fluctuations in the CCD could result from various processes that create an imbalance between calcium (Ca) sources to, and sinks from, the ocean (e.g., weathering and CaCO3 deposition), with different effects on the isotopic composition of dissolved Ca in the oceans due to differences in the Ca isotopic composition of various inputs and outputs. We used Ca isotope ratios (??44/40Ca) of coeval pelagic marine barite and bulk carbonate to evaluate changes in the marine Ca cycle across the EOT. We show that the permanent deepening of the CCD was not accompanied by a pronounced change in seawater ??44/40Ca, whereas time intervals in the Neogene with smaller carbonate depositional changes are characterized by seawater ??44/40Ca shifts. This suggests that the response of seawater ??44/40Ca to changes in weathering fluxes and to imbalances in the oceanic alkalinity budget depends on the chemical composition of seawater. A minor and transient fluctuation in the Ca isotope ratio of bulk carbonate may reflect a change in isotopic fractionation associated with CaCO3 precipitation from seawater due to a combination of factors, including changes in temperature and/or in the assemblages of calcifying organisms. ?? 2011 Geological Society of America.

  13. Table Salt from Seawater (Solar Evaporation). What We Take from Our Environment. Science and Technology Education in Philippine Society.

    Science.gov (United States)

    Philippines Univ., Quezon City. Science Education Center.

    This module discusses methods of obtaining table salt from seawater. Topic areas considered include: (1) obtaining salt by solar evaporation of seawater in holes; (2) obtaining salt by boiling seawater in pots; (3) how table salt is obtained from seawater in the Philippines; and (4) methods of making salt by solar evaporation of seawater in the…

  14. Corrosion and antifouling characteristics of technetium 99 in seawater

    International Nuclear Information System (INIS)

    Spitsyn, V.I.; Strekalov, P.V.; Balakhovskij, O.A.; Mikhajlovskij, Yu.N.

    1982-01-01

    The results are presented of studying the corrosive and antifouling properties of metallic technetium-99 in the Barents Sea and the Sea of Japan. Foil of 99 Tc glued on acrylic plastic served as a sample. High corrosion resistance and antifouling properties exhibited by 99 Tc in seawater point to favorable prospects of further studies aimed at development of new methods for protection against corrosion and fouling of metallic structures and parts with the use of technetium. The antifouling properties of technetium would evidently be used most efficiently when coating materials of high corrosion resistance to seawater (titanium, stainless steels, special alloys, etc.) with layers of technetium. The use of technetium for coating low-alloyed or carbon steels employed in seawater is yet problematic

  15. Seawater desalination using small and medium light water reactors

    International Nuclear Information System (INIS)

    Shimamura, Kazuo

    2000-01-01

    Water is an essential substance for sustaining human life. As Japan is an island country, surrounded by the sea and having abundant rainfall, there is no scarcity of water in daily life except during abnormally dry summers or after disasters such as earthquakes. Consequently, there is hardly any demand for seawater desalination plants except on remote islands, Okinawa and a part of Kyushu. However, the IAEA has forecast a scarcity of drinking water in developing countries at the beginning of the 21st century. Further, much more irrigation water will be required every year to prevent cultivated areas from being lost by desertification. If developing countries were to produce such water by seawater desalination using current fossil fuel energy technology, it would cause increased air pollution and global warming. This paper explains the concept of seawater desalination plants using small and medium water reactors (hereinafter called 'nuclear desalination'), as well as important matters regarding the export nuclear desalination plants to developing countries. (author)

  16. Algal blooms: an emerging threat to seawater reverse osmosis desalination

    KAUST Repository

    Villacorte, Loreen O.

    2014-08-04

    Seawater reverse osmosis (SWRO) desalination technology has been rapidly growing in terms of installed capacity and global application over the last decade. An emerging threat to SWRO application is the seasonal proliferation of microscopic algae in seawater known as algal blooms. Such blooms have caused operational problems in SWRO plants due to clogging and poor effluent quality of the pre-treatment system which eventually forced the shutdown of various desalination plants to avoid irreversible fouling of downstream SWRO membranes. This article summarizes the current state of SWRO technology and the emerging threat of algal blooms to its application. It also highlights the importance of studying the algal bloom phenomena in the perspective of seawater desalination, so proper mitigation and preventive strategies can be developed in the near future. © 2014 © 2014 Balaban Desalination Publications. All rights reserved.

  17. Algal blooms: an emerging threat to seawater reverse osmosis desalination

    KAUST Repository

    Villacorte, Loreen O.; Tabatabai, S. Assiyeh Alizadeh; Dhakal, N.; Amy, Gary L.; Schippers, Jan Cornelis; Kennedy, Maria Dolores

    2014-01-01

    Seawater reverse osmosis (SWRO) desalination technology has been rapidly growing in terms of installed capacity and global application over the last decade. An emerging threat to SWRO application is the seasonal proliferation of microscopic algae in seawater known as algal blooms. Such blooms have caused operational problems in SWRO plants due to clogging and poor effluent quality of the pre-treatment system which eventually forced the shutdown of various desalination plants to avoid irreversible fouling of downstream SWRO membranes. This article summarizes the current state of SWRO technology and the emerging threat of algal blooms to its application. It also highlights the importance of studying the algal bloom phenomena in the perspective of seawater desalination, so proper mitigation and preventive strategies can be developed in the near future. © 2014 © 2014 Balaban Desalination Publications. All rights reserved.

  18. Methane-oxidizing seawater microbial communities from an Arctic shelf

    Science.gov (United States)

    Uhlig, Christiane; Kirkpatrick, John B.; D'Hondt, Steven; Loose, Brice

    2018-06-01

    Marine microbial communities can consume dissolved methane before it can escape to the atmosphere and contribute to global warming. Seawater over the shallow Arctic shelf is characterized by excess methane compared to atmospheric equilibrium. This methane originates in sediment, permafrost, and hydrate. Particularly high concentrations are found beneath sea ice. We studied the structure and methane oxidation potential of the microbial communities from seawater collected close to Utqiagvik, Alaska, in April 2016. The in situ methane concentrations were 16.3 ± 7.2 nmol L-1, approximately 4.8 times oversaturated relative to atmospheric equilibrium. The group of methane-oxidizing bacteria (MOB) in the natural seawater and incubated seawater was > 97 % dominated by Methylococcales (γ-Proteobacteria). Incubations of seawater under a range of methane concentrations led to loss of diversity in the bacterial community. The abundance of MOB was low with maximal fractions of 2.5 % at 200 times elevated methane concentration, while sequence reads of non-MOB methylotrophs were 4 times more abundant than MOB in most incubations. The abundances of MOB as well as non-MOB methylotroph sequences correlated tightly with the rate constant (kox) for methane oxidation, indicating that non-MOB methylotrophs might be coupled to MOB and involved in community methane oxidation. In sea ice, where methane concentrations of 82 ± 35.8 nmol kg-1 were found, Methylobacterium (α-Proteobacteria) was the dominant MOB with a relative abundance of 80 %. Total MOB abundances were very low in sea ice, with maximal fractions found at the ice-snow interface (0.1 %), while non-MOB methylotrophs were present in abundances similar to natural seawater communities. The dissimilarities in MOB taxa, methane concentrations, and stable isotope ratios between the sea ice and water column point toward different methane dynamics in the two environments.

  19. Analytical approximations to seawater optical phase functions of scattering

    Science.gov (United States)

    Haltrin, Vladimir I.

    2004-11-01

    This paper proposes a number of analytical approximations to the classic and recently measured seawater light scattering phase functions. The three types of analytical phase functions are derived: individual representations for 15 Petzold, 41 Mankovsky, and 91 Gulf of Mexico phase functions; collective fits to Petzold phase functions; and analytical representations that take into account dependencies between inherent optical properties of seawater. The proposed phase functions may be used for problems of radiative transfer, remote sensing, visibility and image propagation in natural waters of various turbidity.

  20. Recent work at MIT on uranium recovery from seawater

    International Nuclear Information System (INIS)

    Driscoll, M.J.

    1984-01-01

    Recent work at MIT has confirmed the superiority of fiber-form ion exchange media for uranium recovery from seawater, subject to demonstration of the ability to control fouling by suspended particulate matter. Calculations and laboratory experiments indicate loading rates of several hundred ppm U/day: an order of magnitude faster than for bead-type sorbers in fixed or fluidized beds. A high performance, modular, sorber cartridge/seawater contactor system capable of a lifetime-levelized cost of product in the range 100-150 $/1b U 3 O 8 has been designed. (author)

  1. Determination of thorium concentration in seawater by neutron activation analysis

    International Nuclear Information System (INIS)

    Huh, C.A.; Bacon, M.P.

    1985-01-01

    A sensitive neutron activation analysis method has been successfully developed to determine 232 Th concentration in seawater. The method involves both preirradiation and postirradiation radiochemical separations. The isotopes were separated from the samples and purified during the preirradiation chemistry. 233 Pa was extracted and counted after the irradiation. Yields were monitored with 230 Th and 231 Pa tracers. The separation and purification schemes include ion exchange chromatography and solvent extraction. By this method the authors have measured 232 Th concentrations in some seawater samples that are 1 order of magnitude lower than most previously reported values. 21 references, 3 figures, 2 tables

  2. The major-ion composition of Carboniferous seawater

    Science.gov (United States)

    Holt, Nora M.; García-Veigas, Javier; Lowenstein, Tim K.; Giles, Peter S.; Williams-Stroud, Sherilyn

    2014-06-01

    The major-ion chemistry (Na+, Mg2+, Ca2+, K+, SO42-, and Cl-) of Carboniferous seawater was determined from chemical analyses of fluid inclusions in marine halites, using the cryo scanning electron microscopy (Cryo-SEM) X-ray energy-dispersive spectrometry (EDS) technique. Fluid inclusions in halite from the Mississippian Windsor and Mabou Groups, Shubenacadie Basin, Nova Scotia, Canada (Asbian and Pendleian Substages, 335.5-330 Ma), and from the Pennsylvanian Paradox Formation, Utah, USA, (Desmoinesian Stage 309-305 Ma) contain Na+-Mg2+-K+-Ca2+-Cl- brines, with no measurable SO42-, which shows that the Carboniferous ocean was a “CaCl2 sea”, relatively enriched in Ca2+ and low in SO42- with equivalents Ca2+ > SO42- + HCO3-. δ34S values from anhydrite in the Mississippian Shubenacadie Basin (13.2-14.0 ‰) and the Pennsylvanian Paradox Formation (11.2-12.6 ‰) support seawater sources. Br in halite from the Shubenacadie Basin (53-111 ppm) and the Paradox Basin (68-147 ppm) also indicate seawater parentages. Carboniferous seawater, modeled from fluid inclusions, contained ∼22 mmol Ca2+/kg H2O (Mississippian) and ∼24 mmol Ca2+/kg H2O (Pennsylvanian). Estimated sulfate concentrations are ∼14 mmol SO42-/kg H2O (Mississippian), and ∼12 mmol SO42-/kg H2O (Pennsylvanian). Calculated Mg2+/Ca2+ ratios are 2.5 (Mississippian) and 2.3 (Pennsylvanian), with an estimated range of 2.0-3.2. The fluid inclusion record of seawater chemistry shows a long period of CaCl2 seas in the Paleozoic, from the Early Cambrian through the Carboniferous, when seawater was enriched in Ca2+ and relatively depleted in SO42-. During this ∼200 Myr interval, Ca2+ decreased and SO42- increased, but did not cross the Ca2+-SO42- chemical divide to become a MgSO4 sea (when SO42- in seawater became greater than Ca2+) until the latest Pennsylvanian or earliest Permian (∼309-295 Ma). Seawater remained a MgSO4 sea during the Permian and Triassic, for ∼100 Myr. Fluid inclusions also record

  3. Rapid determination of total phenols in seawater by 4-aminoantipyrine colorimetry

    Digital Repository Service at National Institute of Oceanography (India)

    Kadam, A.N.; Bhangale, V.P.

    A rapid and efficient 4-aminoantipyrine (4-AAP) colorimetric method without any cleanup step to determine total phenols in seawater is described. Efficiency of the method for seawater using external addition of phenol concentrations with working...

  4. Physiological indices of seawater readiness in postspawning steelhead kelts

    Science.gov (United States)

    Buelow, Jessica; Moffitt, Christine M.

    2015-01-01

    Management goals to improve the recovery of steelhead (Oncorhynchus mykiss) stocks at risk of extinction include increasing the proportion of postspawning fish that survive and spawn again. To be successful, postspawning steelhead (kelts) migrating downstream to the ocean must prepare physiologically and physically for a seawater transition. We sampled blood, gill filaments, and evaluated the external condition of migrating kelts from an ESA-listed population in the Snake/Columbia River system over two consecutive years to evaluate their physiological readiness for transition to seawater. We chose attributes often considered as measures of preparation for seawater in juveniles, including gill Na+,K+ ATPase activity, plasma electrolytes and hormones to consider factors related to external condition, size and sex. We found kelts in good external condition had plasma profiles similar to downstream-migrating smolts. In addition, we found more than 80% of kelts ranked in good external condition had smolt-like body silvering. We compared measures from migrating kelts with samples obtained from hatchery fish at the time of spawning to confirm that Na+, K+ ATPase activity in kelts was significantly elevated over spawning fish. We found significant differences in gill Na+, K+ ATPase activity in migrating kelts between the years of sampling, but little indication of influence of fish condition. We conclude that the postspawning steelhead sampled exhibited a suite of behaviours, condition and physiology characteristic of fish prepared for successful transition to a seawater environment.

  5. A bio-thermic seawater desalination system using halophytes

    NARCIS (Netherlands)

    Finck, C.

    2014-01-01

    A bio-thermic seawater desalination system using halophytes was developed and successfully tested. A greenhouse as part of a test rig, with different sorts of mangroves, was installed. Measurements showed promising results concerning fresh water relative yielding rates up to 1.4 kg/h/m2 (leaf

  6. State-of-art report on the seawater desalination process

    International Nuclear Information System (INIS)

    Hwang, Young Dong; Kim, Young In; Lee, Doo Jung; Chang, Moon Hee

    2000-11-01

    Desalination technologies have been developed over the last 40 years and become a reliable industrial process for water production from sea or blackish water. At present, various desalination processes are available for the effective use of seawater or blackish water as valuable water resources. Since a large amount of energy is required for seawater desalination, the cost of energy is important for desalination. For the regions of severe water shortage, however, desalination is the most economical way of water supply compare to any other alternatives. Currently, water supply by seawater desalination is being increased in the areas of the Caribbean, North African and Middle East. Also, desalination of blackish water is being increased in the south-east region of USA. In general, the distillation process and the membrane technology are used for seawater esalination and the membrane and the electric-dialysis for blackish water. However, the selection of the desalination process is highly dependent on the use of produced water and the local environmental conditions where the desalination plant installed. The local condition is the most important parameters for the selection of the desalination process

  7. Fugacity analysis of polycyclic aromatic hydrocarbons between microplastics and seawater

    Science.gov (United States)

    Lee, Hwang; Chang, Sein; Kim, Seung-Kyu; Kwon, Jung-Hwan

    2017-03-01

    Recently, the accumulation of plastic debris in the marine environment has become a great concern worldwide. Although plastics are biologically and chemically inert, plastic debris has been suspected of causing adverse effects on ecosystems due to the increase in reactivity by size reduction and/or micropollutants associated with plastics. Because of the high sorption capacity of microplastics toward organic micropollutants, it is suspected that microplastics may play roles in the distribution and fate of micropollutants. In order to quantitatively evaluate the "net flow" of environmental contaminants in water-plastic-organism systems, a fugacity analysis was conducted using concentrations of polycyclic aromatic hydrocarbons (PAHs) in open oceans and in polyethylene as a representative material of plastic debris. Ratio of fugacity in polyethylene to that in seawater showed a decreasing trend with increasing partition coefficient between polyethylene and seawater (KPE/sw). This indicates that phase equilibrium between polyethylene and seawater is not attained for higher molecular weight PAHs. Disequilibrium of high molecular weight PAHs suggests that transfer from seawater to plastic debris is thermodynamically driven and the role of plastic debris as a vector to transfer them to living organisms would be minimal. However, additives may slowly migrate from plastics into the environment causing potentially serious effects on ecosystems.

  8. Distribution coefficient of plutonium between sediment and seawater

    International Nuclear Information System (INIS)

    Duursma, E.K.; Parsi, P.

    1974-01-01

    Using plutonium 237 as a tracer, a series of experiments were conducted to determine the distribution coefficient of plutonium onto sediments both under oxic and anoxic conditions, where the plutonium was added to seawater in three different valence states: III, IV and VI

  9. Adsorption behavior of lithium from seawater using manganese oxide adsorbent

    International Nuclear Information System (INIS)

    Wajima, Takaaki; Munakata, Kenzo; Uda, Tatsuhiko

    2012-01-01

    The deuterium-tritium (D-T) fusion reactor system is expected to provide the main source of electricity in the future. Large amounts of lithium will be required, dependent on the reactor design concept, and alternative resources should be found to provide lithium inventories for nuclear fusion plants. Seawater has recently become an attractive source of this element and the separation and recovery of lithium from seawater by co-precipitation, solvent extraction and adsorption have been investigated. Amongst these techniques, the adsorption method is suitable for recovery of lithium from seawater, because certain inorganic ion-exchange materials, especially spinel-type manganese oxides, show extremely high selectivity for the lithium ion. In this study, we prepared a lithium adsorbent (HMn 2 O 4 ) by elution of spinel-type lithium di-manganese-tetra-oxide (LiMn 2 O 4 ) and examined the kinetics of the adsorbent for lithium ions in seawater using a pseudo-second-order kinetic model. The intermediate, LiMn 2 O 4 , can be synthesized from LiOH·H 2 O and Mn 3 O 4 , from which the lithium adsorbent can subsequently be prepared via acid treatment., The adsorption kinetics become faster and the amount of lithium adsorbed on the adsorbent increases with increasing solution temperature. The thermodynamic values, ΔG 0 , ΔH 0 and ΔS 0 , indicate that adsorption is an endothermic and spontaneous process. (author)

  10. Controlling Biofouling in Seawater Reverse Osmosis Membrane Systems

    NARCIS (Netherlands)

    Dhakal, N.

    2017-01-01

    Seawater desalination is a rapidly growing coastal industry that is increasingly threatened by algal blooms. Depending on the severity of algal blooms, desalination systems may be forced to shut down because of clogging and/or poor feed water quality. To maintain stable operation and provide good

  11. Xanthomarina gelatinilytica gen nov., sp nov., isolated from seawater

    Digital Repository Service at National Institute of Oceanography (India)

    Bhumika, V.; Ravinder, K.; Sharma, G.; Srinivas, T.N.R.; AnilKumar, P.

    A novel Gram-stain-negative, rod-shaped, yellow-pigmented, non-sporulating, non-motile bacterium, designated strain AK20T, was isolated from seawater collected from Kochi city, Kerala state, India Colonies on marine agar were circular...

  12. Roseovarius azorensis sp. nov., isolated from seawater at Espalamaca, Azores

    Digital Repository Service at National Institute of Oceanography (India)

    Rajasabapathy, R.; Mohandass, C; Dastager, S.G.; Liu, Q.; Khieu, T.-N.; Son, C; Li, W.-J; Colaco, A.

    A Gram-negative, motile, non-spore forming, rod shaped aerobic bacterium, designated strain SSW084T, was isolated from a surface seawater sample collected at Espalamaca (38°33`N; 28°39`W), Azores. Growth was found to occur from 15 to 40...

  13. Management of the Tobruk power station and seawater desalination plant

    Energy Technology Data Exchange (ETDEWEB)

    Homann, H J

    1983-01-01

    BBC and two consortium firms provided, for one year, the management personnel for operation and maintenance of the power and seawater desalination plant in Tobruk, Libya, constructed under the leadership of BBC. The plant organisation was established at site in cooperation with the client. Following thorough training, the client's staff took over plant management after one year according to contract.

  14. Detection of salmonella in shellfish grown in polluted seawater

    CSIR Research Space (South Africa)

    Kfir, R

    1993-01-01

    Full Text Available Three bays along the South African coast were studied for the presence of Salmonella spp in seawater, effluent and storm water discharges into the bays and in shellfish harvested at the same sites. The microbial quality of water and shellfish...

  15. Freeze desalination of seawater using LNG cold energy

    KAUST Repository

    Chang, Jian; Zuo, Jian; Lu, Kang-Jia; Chung, Neal Tai-Shung

    2016-01-01

    With the aid of cold energy from regasification of liquefied natural gas (LNG), freeze desalination (FD) is an emerging technology for seawater desalination because of its low energy characteristics and insensitivities to fouling problems. This work aims to investigate the major operating parameters of FD such as coolant temperature, freezing duration, supercooling, seeding, agitation, crystallizer material and subsequent washing procedure on ice production and water quality. It was found that the optimal freezing duration per batch was 1 h for an iron crystallizer and 1.5 h for a glass crystallizer. The optimal coolant temperature should be around −8 °C. The optimal amount of washing water to clean the raw ice was about 50 wt% of the raw ice. Over 50 wt% of the feed could be recovered as raw ice within 1 h, which means an overall ice recovery rate of higher than 25% (of the original seawater), considering the consumption of washing water. Both artificial and real seawater were tested under the optimized conditions. The total dissolved solid in the product ice was around 300 ppm, which met the World Health Organization (WHO) potable water salinity standard of 500 ppm. Therefore, the process parameters optimized in this study can be directly used for the freeze desalination of seawater.

  16. The density-salinity relation of standard seawater

    Science.gov (United States)

    Schmidt, Hannes; Seitz, Steffen; Hassel, Egon; Wolf, Henning

    2018-01-01

    The determination of salinity by means of electrical conductivity relies on stable salt proportions in the North Atlantic Ocean, because standard seawater, which is required for salinometer calibration, is produced from water of the North Atlantic. To verify the long-term stability of the standard seawater composition, it was proposed to perform measurements of the standard seawater density. Since the density is sensitive to all salt components, a density measurement can detect any change in the composition. A conversion of the density values to salinity can be performed by means of a density-salinity relation. To use such a relation with a target uncertainty in salinity comparable to that in salinity obtained from conductivity measurements, a density measurement with an uncertainty of 2 g m-3 is mandatory. We present a new density-salinity relation based on such accurate density measurements. The substitution measurement method used is described and density corrections for uniform isotopic and chemical compositions are reported. The comparison of densities calculated using the new relation with those calculated using the present reference equations of state TEOS-10 suggests that the density accuracy of TEOS-10 (as well as that of EOS-80) has been overestimated, as the accuracy of some of its underlying density measurements had been overestimated. The new density-salinity relation may be used to verify the stable composition of standard seawater by means of routine density measurements.

  17. Freeze desalination of seawater using LNG cold energy

    KAUST Repository

    Chang, Jian

    2016-06-23

    With the aid of cold energy from regasification of liquefied natural gas (LNG), freeze desalination (FD) is an emerging technology for seawater desalination because of its low energy characteristics and insensitivities to fouling problems. This work aims to investigate the major operating parameters of FD such as coolant temperature, freezing duration, supercooling, seeding, agitation, crystallizer material and subsequent washing procedure on ice production and water quality. It was found that the optimal freezing duration per batch was 1 h for an iron crystallizer and 1.5 h for a glass crystallizer. The optimal coolant temperature should be around −8 °C. The optimal amount of washing water to clean the raw ice was about 50 wt% of the raw ice. Over 50 wt% of the feed could be recovered as raw ice within 1 h, which means an overall ice recovery rate of higher than 25% (of the original seawater), considering the consumption of washing water. Both artificial and real seawater were tested under the optimized conditions. The total dissolved solid in the product ice was around 300 ppm, which met the World Health Organization (WHO) potable water salinity standard of 500 ppm. Therefore, the process parameters optimized in this study can be directly used for the freeze desalination of seawater.

  18. Contribution of anthropic activities to the seawater pollution at the ...

    African Journals Online (AJOL)

    The high toxicity of seawater is due to the presence of lead and cadmium with concentrations exceeding 60 times the normal value (0.015 mg/l). Moreover, the deficit in D.O announces strong biological activities. This wild aggression is related to the industrial discharges in the port area. Keywords: marine pollution; heavy ...

  19. Removal of trihalomethane from chlorinated seawater using gamma radiation.

    Science.gov (United States)

    Rajamohan, R; Natesan, Usha; Venugopalan, V P; Rajesh, Puspalata; Rangarajan, S

    2015-12-01

    Chlorine addition as a biocide in seawater results in the formation of chlorination by-products such as trihalomethanes (THMs). Removal of THMs is of importance as they are potential mutagenic and carcinogenic agents. In this context, a study was conducted that used ionizing radiation to remove THMs from chlorinated (1, 3, and 5 mg/L) seawater by applying various dosages (0.4-5.0 kGy) of gamma radiation. Bromoform (BF) showed a faster rate of degradation as compared to other halocarbons such as bromodichloromethane (BDCM) and dibromochloromethane (DBCM). In chlorine-dosed seawater, total irradiation dose of 0.4 to 5 kGy caused percentage reduction in the range of 6.9 to 76.7%, 2.3 to 99.6%, and 45.7 to 98.3% for BDCM, DBCM, and BF, respectively. During the irradiation process, pH of the chlorinated seawater decreased with increase in the absorbed dose; however, no change in total organic carbon (TOC) was observed. The results show that gamma dose of 2.5 kGy was adequate for maximum degradation of THM; but for complete mineralization, higher dose would be required.

  20. State-of-art report on the seawater desalination process

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Young Dong; Kim, Young In; Lee, Doo Jung; Chang, Moon Hee

    2000-11-01

    Desalination technologies have been developed over the last 40 years and become a reliable industrial process for water production from sea or blackish water. At present, various desalination processes are available for the effective use of seawater or blackish water as valuable water resources. Since a large amount of energy is required for seawater desalination, the cost of energy is important for desalination. For the regions of severe water shortage, however, desalination is the most economical way of water supply compare to any other alternatives. Currently, water supply by seawater desalination is being increased in the areas of the Caribbean, North African and Middle East. Also, desalination of blackish water is being increased in the south-east region of USA. In general, the distillation process and the membrane technology are used for seawater esalination and the membrane and the electric-dialysis for blackish water. However, the selection of the desalination process is highly dependent on the use of produced water and the local environmental conditions where the desalination plant installed. The local condition is the most important parameters for the selection of the desalination process.

  1. Dynamic Bubble Surface Tension Measurements in Northwest Atlantic Seawater

    Science.gov (United States)

    Kieber, D. J.; Long, M. S.; Keene, W. C.; Kinsey, J. D.; Frossard, A. A.; Beaupre, S. R.; Duplessis, P.; Maben, J. R.; Lu, X.; Chang, R.; Zhu, Y.; Bisgrove, J.

    2017-12-01

    Numerous reports suggest that most organic matter (OM) associated with newly formed primary marine aerosol (PMA) originates from the sea-surface microlayer. However, surface-active OM rapidly adsorbs onto bubble surfaces in the water column and is ejected into the atmosphere when bubbles burst at the air-water interface. Here we present dynamic surface tension measurements of bubbles produced in near surface seawater from biologically productive and oligotrophic sites and in deep seawater collected from 2500 m in the northwest Atlantic. In all cases, the surface tension of bubble surfaces decreased within seconds after the bubbles were exposed to seawater. These observations demonstrate that bubble surfaces are rapidly saturated by surfactant material scavenged from seawater. Spatial and diel variability in bubble surface evolution indicate corresponding variability in surfactant concentrations and/or composition. Our results reveal that surface-active OM is found throughout the water column, and that at least some surfactants are not of recent biological origin. Our results also support the hypothesis that the surface microlayer is a minor to negligible source of OM associated with freshly produced PMA.

  2. Chemical Characteristics of Seawater and Sediment in the Yap Trench

    Science.gov (United States)

    Ding, H.; Sun, C.; Yang, G.

    2017-12-01

    In June 2016, seawater samples at sediment-seawater interface and sediment samples were collected by the he Jiaolong, China's manned submersible, at four sampling sites located in the Yap Trench. Seawater samples from different depths of the trench were also collected by CTD. Chemical parameters, including pH, alkanility, concentrations of dissolved inorganic carbon, dissolved and total organic carbon, methane, dimethylsulfoniopropionate, nutrients, carbohydrates, and amino acids were analyzed in the seawater samples. Concentrations of total organic carbon, six constant elements and nine trace elements were determined in the sediment samples. All the vertical profiles of the chemical parameters in the seawater have unique characteristics. Our resluts also showed that the carbonate compensation depth (CCD) was between 4500 m and 5000 m in the trench. The hadal sediment at 6500 m depth under the CCD line was siliceous ooze favored for the burial of orgaic carbon, attributed to accumulation of surface sediment by gravity flow. The abyssal sediment at the 4500 m depth was calcareous ooze. Various microfossils, such as discoasters and diatoms, were identified in different sediment layers of the sediment samples.Based on the ratios of Fe/Al and Ti/Al, and the correlation between different elements, the sediment in the Yap Trench were derived from biogenic, terrestrial, volcanic and autogenic sources. The ratios of Ni/Co and V/Cr showed that the deposition environment of the trench should be oxidative, arributed to inflow of the Antractic bottom oxygen-rich seawater.The high concentraiont of Ca in the sediment from the station 371-Yap-S02 below 4 cm depth indicated that there was no large-scale volcanic eruption in the research area and the volcanic materials in the sediment might orginated from the Mariana Volcanic Arc, and the Carolyn Ridge has been slowly sinking on the east side of the trench due to plate subduction. This study is the first systematic study of

  3. 76 FR 14953 - Notice of Availability of Draft Environmental Impact Statement for the Proposed Honolulu Seawater...

    Science.gov (United States)

    2011-03-18

    ... air conditioning system for downtown Honolulu buildings. In order to obtain deep, cold seawater to..., utilize, and return deep, cold seawater, Honolulu Seawater Air Conditioning, LLC (applicant) proposes to... visiting the USACE Honolulu District Web site at http://www.poh.usace.army.mil and selecting ``Public...

  4. Full utilization of silt density index (SDI) measurements for seawater pre-treatment

    KAUST Repository

    Wei, Chunhai; Laborie, Sté phanie; Ben Aï m, Roger M.; Amy, Gary L.

    2012-01-01

    according to the standard protocol for SDI measurement, in which two kinds of 0.45μm membranes of different material and seawater samples from the Mediterranean including raw seawater and seawater pre-treated by coagulation followed by sand filtration (CSF

  5. Extraction of Carbon Dioxide and Hydrogen from Seawater and Hydrocarbon Production Therefrom

    Science.gov (United States)

    2016-04-05

    acidification of seawater by subjecting the seawater to an ion exchange reaction to exchange H.sup. ions for Na.sup. ions. Carbon dioxide may be...extracted from the acidified seawater. Optionally, the ion exchange reaction can be conducted under conditions which produce hydrogen as well as carbon dioxide . The carbon dioxide and hydrogen may be used to produce hydrocarbons.

  6. Adsorption and desorption of phosphate on limestone in experiments simulating seawater intrusion

    Science.gov (United States)

    The absorption and desorption of phosphorus on a large block of limestone was investigated using deionized water (DIW) and seawater. The limestone had a high affinity to adsorb phosphorus in DIW. Phosphate adsorption was significantly less in seawater, and more phosphorus was desorbed in the seawate...

  7. Decomposition of dilute residual active chlorine in sea-water

    International Nuclear Information System (INIS)

    Yoshinaga, Tetsutaro; Kawano, Kentaro; Yanagase, Kenjiro; Shiga, Akira

    1985-01-01

    Coastal industries such as power stations require enormous quantities of sea-water for cooling, but the marine organisms in it often result in fouling and/or blockade of the circulating water condenser and pipeworks. To prevent this, chlorine, or hypochlorite by the direct electrolysis of sea-water have been added. Environmental concerns, however, dictate that the residual chlorine concentration at the outlet should be less than the regulated value (0.02 ppm). Methods for decomposing dilute residual chlorine solutions were therefore studied. It was found that: 1) The addition of (raw) sea-water to the sea-water which passed through the condenser lowered the residual chlorine concentration to an greater extent than could be expected by dilution only. 2) Ozonation of the residual chlorine solution led to degradation of OCl - , but in solutions with a residual chlorine concentrations of less than 3 -- 4 ppm, ozonation had no effect. 3) Irradiation with ultra violet light (254 nm) decomposed the residual chlorine. Under the present work conditions (25 0 C: pH 8; depth 10 mm), nearly first order kinetics were to hold [da/dt = ksub((1)) (1-a)sup(n)]. There is a proportional relationship between the kinetic constant (k) and illuminous intensity (L), i.e., ksub((1))[C 0 sup(Cl 2 ): 10 ppm] = 6.56 x 10 -5 L (L = 0 -- 1000 lx). Thus, the use of both sea-water addition and UV irradiation provides a probable method for decomposing a residual chlorine to the expected concentration. (author)

  8. Radiation-induced reactions of Cl-, CO32-, and Br- in seawater, - Model calculation of gamma radiolysis of seawater

    International Nuclear Information System (INIS)

    Hata, Kuniki; Hanawa, Satoshi; Kasahara, Shigeki; Muroya, Yusa; Katsumura, Yosuke

    2012-09-01

    Gamma-radiolysis of seawater has been simulated to estimate the concentrations of radiolysis products. Although gas products such as H 2 , O 2 and H 2 O 2 in irradiated pure water quickly attain the steady state with very low concentrations, the products in seawater monotonically increase with dose. It was found that H 2 is produced almost linearly with dose, and corresponding G-value was 4.4 x 10 -8 mol J -1 . As similar result was obtained from the calculation of 8 x 10 -4 mol dm -3 NaBr solution, the origin of the linear increase in seawater was attributable to be the reactions of Br - . According to the sensitivity analysis, three reactions, 1: Br - + ·OH → BrOH· - , 2: BrOH· - → Br - + ·OH, and 3: BrOH· - → Br· + OH - , determined the concentrations of the products. The presence of Cl - and HCO 3 - in seawater hardly affected the concentrations of the radiolysis products. Oxyanions derived from Cl - and Br - were not obtained at observable concentration. (authors)

  9. Coral calcifying fluid pH is modulated by seawater carbonate chemistry not solely seawater pH.

    Science.gov (United States)

    Comeau, S; Tambutté, E; Carpenter, R C; Edmunds, P J; Evensen, N R; Allemand, D; Ferrier-Pagès, C; Tambutté, S; Venn, A A

    2017-01-25

    Reef coral calcification depends on regulation of pH in the internal calcifying fluid (CF) in which the coral skeleton forms. However, little is known about calcifying fluid pH (pH CF ) regulation, despite its importance in determining the response of corals to ocean acidification. Here, we investigate pH CF in the coral Stylophora pistillata in seawater maintained at constant pH with manipulated carbonate chemistry to alter dissolved inorganic carbon (DIC) concentration, and therefore total alkalinity (A T ). We also investigate the intracellular pH of calcifying cells, photosynthesis, respiration and calcification rates under the same conditions. Our results show that despite constant pH in the surrounding seawater, pH CF is sensitive to shifts in carbonate chemistry associated with changes in [DIC] and [A T ], revealing that seawater pH is not the sole driver of pH CF Notably, when we synthesize our results with published data, we identify linear relationships of pH CF with the seawater [DIC]/[H + ] ratio, [A T ]/ [H + ] ratio and [[Formula: see text

  10. Atmospheric Aerosol Emissions Related to the Mediterranean Seawater Biogeochemistry

    Science.gov (United States)

    Sellegri, K.; Schwier, A.; Rose, C.; Gazeau, F. P. H.; Guieu, C.; D'anna, B.; Ebling, A. M.; Pey, J.; Marchand, N.; Charriere, B.; Sempéré, R.; Mas, S.

    2016-02-01

    Marine aerosols contribute significantly to the global aerosol load and consequently has an important impact on the Earth's climate. Different factors influence the way they are produced at the air/seawater interface. The sea state (whitecap coverage, temperature, etc. ) influence the size and concentration of primarily produced particles but also biogeochemical characteristics of the seawater influence both the physical and chemical primary fluxes to the atmosphere. An additional aerosol source of marine aerosol to the atmosphere is the formation of new particles by gaz-to-particle conversion, i.e. nucleation. How the seawater and surface microlayer biogeochemical compositions influences the aerosol emissions is still a large debate. In order to study marine emissions, one approach is to use semi-controlled environments such as mesocosms. Within the MedSea and SAM projects, we characterize the primary Sea Spray Aerosol (SSA) during mesocosms experiments performed during different seasons in the Mediteranean Sea. Mesocosms were either left unchanged as control or enriched by addition of nutriments in order to create different levels of phytoplanctonic activities. The mesocosms waters were daily analyzed for their chemical and biological composition (DOC, CDOM, TEP, Chl-a, virus, bacteria, phytoplankton and zooplankton concentrations). SSA production by bubble bursting was daily simulated in a dedicated set-up. The size segregated SSA number fluxes, cloud condensation nuclei (CCN) properties, and chemical composition were determined as a function of the seawater characteristics. We show that the SSA organic content was clearly correlated to the seawater Chl-a level, provided that the mesocosm was not enriched to create an artificial phytoplanctonic bloom. In our experiments, the enrichment of the seawater with natural surface microlayer did not impact the SSA organic content nor its CCN properties. At last, nucleation of secondary particles were observed to occur in

  11. Development of Novel Sorbents for Uranium Extraction from Seawater

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Wenbin [Univ. of Chicago, IL (United States); Taylor-Pashow, Kathryn [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2014-01-08

    As the uranium resource in terrestrial ores is limited, it is difficult to ensure a long-term sustainable nuclear energy technology. The oceans contain approximately 4.5 billion tons of uranium, which is one thousand times the amount of uranium in terrestrial ores. Development of technologies to recover the uranium from seawater would greatly improve the uranium resource availability, sustaining the fuel supply for nuclear energy. Several methods have been previously evaluated including solvent extraction, ion exchange, flotation, biomass collection, and adsorption; however, none have been found to be suitable for reasons such as cost effectiveness, long term stability, and selectivity. Recent research has focused on the amidoxime functional group as a promising candidate for uranium sorption. Polymer beads and fibers have been functionalized with amidoxime functional groups, and uranium adsorption capacities as high as 1.5 g U/kg adsorbent have recently been reported with these types of materials. As uranium concentration in seawater is only ~3 ppb, great improvements to uranium collection systems must be made in order to make uranium extraction from seawater economically feasible. This proposed research intends to develop transformative technologies for economic uranium extraction from seawater. The Lin group will design advanced porous supports by taking advantage of recent breakthroughs in nanoscience and nanotechnology and incorporate high densities of well-designed chelators into such nanoporous supports to allow selective and efficient binding of uranyl ions from seawater. Several classes of nanoporous materials, including mesoporous silica nanoparticles (MSNs), mesoporous carbon nanoparticles (MCNs), meta-organic frameworks (MOFs), and covalent-organic frameworks (COFs), will be synthesized. Selective uranium-binding liagnds such as amidoxime will be incorporated into the nanoporous materials to afford a new generation of sorbent materials that will be

  12. Development of Novel Sorbents for Uranium Extraction from Seawater

    International Nuclear Information System (INIS)

    Lin, Wenbin; Taylor-Pashow, Kathryn

    2014-01-01

    As the uranium resource in terrestrial ores is limited, it is difficult to ensure a long-term sustainable nuclear energy technology. The oceans contain approximately 4.5 billion tons of uranium, which is one thousand times the amount of uranium in terrestrial ores. Development of technologies to recover the uranium from seawater would greatly improve the uranium resource availability, sustaining the fuel supply for nuclear energy. Several methods have been previously evaluated including solvent extraction, ion exchange, flotation, biomass collection, and adsorption; however, none have been found to be suitable for reasons such as cost effectiveness, long term stability, and selectivity. Recent research has focused on the amidoxime functional group as a promising candidate for uranium sorption. Polymer beads and fibers have been functionalized with amidoxime functional groups, and uranium adsorption capacities as high as 1.5 g U/kg adsorbent have recently been reported with these types of materials. As uranium concentration in seawater is only ~3 ppb, great improvements to uranium collection systems must be made in order to make uranium extraction from seawater economically feasible. This proposed research intends to develop transformative technologies for economic uranium extraction from seawater. The Lin group will design advanced porous supports by taking advantage of recent breakthroughs in nanoscience and nanotechnology and incorporate high densities of well-designed chelators into such nanoporous supports to allow selective and efficient binding of uranyl ions from seawater. Several classes of nanoporous materials, including mesoporous silica nanoparticles (MSNs), mesoporous carbon nanoparticles (MCNs), meta-organic frameworks (MOFs), and covalent-organic frameworks (COFs), will be synthesized. Selective uranium-binding liagnds such as amidoxime will be incorporated into the nanoporous materials to afford a new generation of sorbent materials that will be

  13. Impediment to Symbiosis Establishment between Giant Clams and Symbiodinium Algae Due to Sterilization of Seawater

    Science.gov (United States)

    Kurihara, Takeo; Yamada, Hideaki; Inoue, Ken; Iwai, Kenji; Hatta, Masayuki

    2013-01-01

    To survive the juvenile stage, giant clam juveniles need to establish a symbiotic relationship with the microalgae Symbiodinium occurring in the environment. The percentage of giant clam juveniles succeeding in symbiosis establishment (“symbiosis rate”) is often low, which is problematic for seed producers. We investigated how and why symbiosis rates vary, depending on whether giant clam seeds are continuously reared in UV treated or non treated seawater. Results repeatedly demonstrated that symbiosis rates were lower for UV treated seawater than for non treated seawater. Symbiosis rates were also lower for autoclaved seawater and 0.2-µm filtered seawater than for non treated seawater. The decreased symbiosis rates in various sterilized seawater suggest the possibility that some factors helping symbiosis establishment in natural seawater are weakened owing to sterilization. The possible factors include vitality of giant clam seeds, since additional experiments revealed that survival rates of seeds reared alone without Symbiodinium were lower in sterilized seawater than in non treated seawater. In conclusion, UV treatment of seawater was found to lead to decreased symbiosis rates, which is due possibly to some adverse effects common to the various sterilization techniques and relates to the vitality of the giant clam seeds. PMID:23613802

  14. Impediment to symbiosis establishment between giant clams and Symbiodinium algae due to sterilization of seawater.

    Science.gov (United States)

    Kurihara, Takeo; Yamada, Hideaki; Inoue, Ken; Iwai, Kenji; Hatta, Masayuki

    2013-01-01

    To survive the juvenile stage, giant clam juveniles need to establish a symbiotic relationship with the microalgae Symbiodinium occurring in the environment. The percentage of giant clam juveniles succeeding in symbiosis establishment ("symbiosis rate") is often low, which is problematic for seed producers. We investigated how and why symbiosis rates vary, depending on whether giant clam seeds are continuously reared in UV treated or non treated seawater. Results repeatedly demonstrated that symbiosis rates were lower for UV treated seawater than for non treated seawater. Symbiosis rates were also lower for autoclaved seawater and 0.2-µm filtered seawater than for non treated seawater. The decreased symbiosis rates in various sterilized seawater suggest the possibility that some factors helping symbiosis establishment in natural seawater are weakened owing to sterilization. The possible factors include vitality of giant clam seeds, since additional experiments revealed that survival rates of seeds reared alone without Symbiodinium were lower in sterilized seawater than in non treated seawater. In conclusion, UV treatment of seawater was found to lead to decreased symbiosis rates, which is due possibly to some adverse effects common to the various sterilization techniques and relates to the vitality of the giant clam seeds.

  15. Modification of Optical Properties of Seawater Exposed to Oil Contaminants Based on Excitation-Emission Spectra

    Science.gov (United States)

    Baszanowska, E.; Otremba, Z.

    2015-10-01

    The optical behaviour of seawater exposed to a residual amount of oil pollution is presented and a comparison of the fluorescence spectra of oil dissolved in both n-hexane and seawater is discussed based on excitation-emission spectra. Crude oil extracted from the southern part of the Baltic Sea was used to characterise petroleum properties after contact with seawater. The wavelength-independent fluorescence maximum for natural seawater and seawater artificially polluted with oil were determined. Moreover, the specific excitation-emission peaks for natural seawater and polluted water were analysed to identify the natural organic matter composition. It was found that fluorescence spectra identification is a promising method to detect even an extremely low concentration of petroleum residues directly in the seawater. In addition, alien substances disturbing the fluorescence signatures of natural organic substances in a marine environment is also discussed.

  16. Desalting seawater and brackish waters: 1981 cost update

    International Nuclear Information System (INIS)

    Reed, S.A.

    1982-08-01

    This is the fourth in a series of desalting cost update reports. Cost data are reported for desalting seawater by various distillation systems and by reverse osmosis. Costs of desalting four brackish waters, representative of those found in the United States by both reverse osmosis and electrodialysis are also given. Cost data are presented parametrically as a function of energy cost and plant size. The cost of desalting seawater by distillation has increased by 40% during the past two years, while desalting by reverse osmosis has increased by about 36% during the same period. Brackish water desalting by reverse osmosis has only increased by about 12%, and brackish water desalting by electrodialysis is up by 40%. Again, the continued increase in energy costs has had a major impact on all desalination systems

  17. Recovery of uranium from seawater by composite fiber adsorbent

    International Nuclear Information System (INIS)

    Kubuke, Y.; Aoki, T.; Tanaka, H.; Tabushi, I.; Kamaishi, T.; Hagiwara, I.

    1991-01-01

    The authors of this paper developed a composite fiber adsorbent (CFA) to entrap finely powdered amidoxime into fibrils of supporting material with silica in a previous report. This was further tested for uranyl recovery directly from seawater. The adsorption rate showed a flow rate dependence with almost a saturation value of ∼100 μg of U/g of CFA at a mean flow rate of sea current. Chemical as well as physical deterioration was overcome by using 1 N NaHCO 3 and 0.72 M NaCl as liberating and washing agents, to keep the pH and ionic strength, respectively, constant, and the initial adsorption rate was maintained even after a recycle time of 50. A continuous passage of seawater showed a linear increase of the adsorption to afford 1560 μg of U/g of CFA after 3 weeks

  18. Monitoring of uranium isotopes in seaweeds and seawater

    International Nuclear Information System (INIS)

    Meena, Balram; Mehendarge, S.T.; Baburajan, A.; Rao, D.D.

    2012-01-01

    The paper deals with the concentration of uranium in seawater and different types of seaweed found along the coast line of Tarapur marine environment. The seaweeds are the trend indicators of heavy metals and radionuclides present in the aquatic environment. Seaweeds also serve as a food to the marine organisms and thus can enter the human being through food chain. The higher concentration of uranium in seafood may have radiological impact on human health. The Tarapur Atomic Power Station is adjoined to the sea and has a rocky surface area, which act as a good dwelling for the growth and survival of marine biota. In present study, separation and measurements were made to determine the uranium concentration in seaweed seawater at Tarapur coastal environment

  19. Durability of Geopolymer Lightweight Concrete Infilled LECA in Seawater Exposure

    Science.gov (United States)

    Razak, R. A.; Abdullah, M. M. A. B.; Yahya, Z.; Hamid, M. S. A.

    2017-11-01

    This paper describes a development of lightweight concrete using lightweight expanded clay aggregate (LECA) in fly ash (FA) based geopolymer immersed in seawater. The objective of this research is to compare the performance of geopolymer concrete (GPC) with ordinary Portland cement (OPC) concrete infilled lightweight expanded clay aggregate (LECA) in seawater exposure. Geopolymer concrete is produced by using alkaline activator to activate the raw material, FA. The highest compressive strength of this study is 42.0 MPa at 28 days and 49.8 MPa at 60 days. The density for this concrete is in the range of 1580 kg/m3 to 1660 kg/m3. The result for water absorption is in the range of 6.82% to 14.72%. However, the test results of weight loss is in the range between 0.30% to 0.43%.

  20. Operational experience of stainless steels in seawater-cooled systems

    International Nuclear Information System (INIS)

    Henriksson, S.

    1981-06-01

    A study has been made of chiefly Swedish and Finnish operational experience of stainless steel in seawater and brackish water. A report is given on 23 typical cases, behind which in actual fact a considerably larger number of individual practical cases are concealed. The answer to the primary question why a standard steel of type SS 2343 (AISI 316) sometimes, contrary to expectation, remains unattacked by local corrosion is that there is usually spontaneous cathodic protection by other less noble components of carbon steel, cast iron or some copper alloy in direct contact with the stainless steel. The study confirms in other respects the adverse effect of residual oxides after welding and the beneficial of low temperature, high continuous waterflow and periodic cleaning, and of rinsing with fresh water during out-of service periods. It also verifies the additional advantages of the new high-alloy special steels which have begun to be marketed in recent years for seawater applications. (author)

  1. Microbiologically Influenced Corrosion in Copper and Nickel Seawater Piping Systems

    Science.gov (United States)

    1990-09-01

    Influenced Tipton, D. G. and Kain, R. M. 1980. Effect of temperature onCorosiope in Nuclear Power Plants atudy a Mical Gnuide the resistance to pitting of...Monel alloy 400 in seawater. In:Corrosion in Nuclear Power Plants anda Practical ie fr Proceedings of Corrosion 󈨔. Chicago, Illinois: National...Sons Ltd. 441 pp. Quimica . Verink, E.D. and Pourbaix, M. 1971. Use of electrochemical Pope, D. H., Duquette, D. J., Johannes, A. H., and Wayner

  2. Atmospheric and marine controls on aerosol iron solubility in seawater

    OpenAIRE

    Baker, A.R.; Croot, Peter

    2010-01-01

    The fraction of atmospherically deposited iron which dissolves in seawater, or becomes available to phytoplankton for growth, is a key determinant of primary productivity in many open ocean regions. As such this parameter plays an important part in the global oceanic cycles of iron and carbon, and yet the factors that control iron dissolution from aerosol are very poorly understood. In this manuscript we seek to synthesise the available knowledge of these factors, which operate in the atmos...

  3. Examining the economics of seawater desalination using the DEEP code

    International Nuclear Information System (INIS)

    2000-11-01

    This Technical Document presents analysis of the results of the study initiated by the IAEA on comparison of costs of nuclear and fossil fuel energy sources coupled with selected seawater desalination processes, including regional studies and sensitivity analysis. The economical modelling was performed with use of the Desalination Economic Evaluation Program code (DEEP) released in 1998 which incorporated the latest advances in economic modelling and technological changes in both desalination and reactor technologies

  4. Comparative ecotoxicity of polystyrene nanoparticles in natural seawater and reconstituted seawater using the rotifer Brachionus plicatilis.

    Science.gov (United States)

    Manfra, L; Rotini, A; Bergami, E; Grassi, G; Faleri, C; Corsi, I

    2017-11-01

    The impact of nanoplastics using model polystyrene nanoparticles (PS NPs), anionic (PS-COOH) and cationic (PS-NH 2 ), has been investigated on the marine rotifer Brachionus plicatilis, a major component of marine zooplanktonic species. The role of different surface charges in affecting PS NP behaviour and toxicity has been considered in high ionic strength media. To this aim, the selected media were standardized reconstituted seawater (RSW) and natural sea water (NSW), the latter resembling more natural exposure scenarios. Hatched rotifer larvae were exposed for 24h and 48h to both PS NPs in the range of 0.5-50μg/ml using PS NP suspensions made in RSW and NSW. No effects on lethality upon exposure to anionic NPs were observed despite a clear gut retention was evident in all exposed rotifers. On the contrary, cationic NPs caused lethality to rotifer larvae but LC 50 values resulted lower in rotifers exposed in RSW (LC 50 =2.75±0.67µg/ml) compared to those exposed in NSW (LC 50 =6.62±0.87µg/ml). PS NPs showed similar pattern of aggregation in both high ionic strength media (RSW and NSW) but while anionic NPs resulted in large microscale aggregates (Z-average 1109 ± 128nm and 998±67nm respectively), cationic NP aggregates were still in nano-size forms (93.99 ± 11.22nm and 108.3 ± 12.79nm). Both PDI and Z-potential of PS NPs slightly differed in the two media suggesting a role of their different surface charges in affecting their behaviour and stability. Our findings confirm the role of surface charges in nanoplastic behaviour in salt water media and provide a first evidence of a different toxicity in rotifers using artificial media (RSW) compared to natural one (NSW). Such evidence poses the question on how to select the best medium in standardized ecotoxicity assays in order to properly assess their hazard to marine life in natural environmental scenarios. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Investigation of the Performance of an Inductive Seawater Conductivity Sensor

    Directory of Open Access Journals (Sweden)

    WU Sheng

    2015-03-01

    Full Text Available As one of the factors in marine hydrographic survey, seawater salinity plays an important role in marine scientific research, marine exploitation and military defense. In practical measurement, the salinity is always presented indirectly by seawater conductivity value. Compared with the electrode conductivity sensors, inductive conductivity sensors have an advantage of anti-biofouling, and that is very interested in long term ocean observation device. From the principle point of view, this paper discus the different methods to improve inductive sensor output signal, which is confirmed by the relative experimental results. The basic working system of inductive sensor is described here as well as a calibration in standard seawater. From a wide range of temperature, measurement absolute error and stability are close to those of actual electrode conductivity sensors. Furthermore, in the 1000 meters deep sea experiment, our inductive sensor presents a perfect similarity of conductivity profile like sea- bird sensor, even for some small variations. The performance of our inductive sensor can compete with that of commercially available electrode conductivity sensors.

  6. Extracting Uranium from Seawater: Benefits, Risks and Policy Implication

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, Aznan Fazli; Yim, Man-Sung; Marsh, Matthew [KAIST, Daejon (Korea, Republic of)

    2015-05-15

    One of the key issues that need to be addressed regarding the future of nuclear power is the availability of uranium. The most economical way to this day of providing uranium for nuclear energy has been through conventional mining. However, the current projection of the well-known, easily obtainable sources of uranium indicates that global nuclear industry can be supported through the end of the century under the once-through cycle. It, however, could be extended up to 250 years if the speculative uranium sources are taken into account. Uranium is also available in seawater. Extracting uranium from seawater has both pros and cons. The only main obstacles at this point is it not economically competitive compared to the conventional mining. Solving this issue will open up a new era of the way of extracting uranium to meet the future requirement of nuclear energy. As the uranium seawater extraction technology is rapidly being developed and might become feasible in the near future, an appropriate mechanism are required to safeguard the extraction technology.

  7. Speciation of cadmium in seawater - a direct voltammetric approach

    International Nuclear Information System (INIS)

    Helmers, E.

    1994-01-01

    The present report deals with differential pulse anodic stripping voltammetry (DPASV) applied for the analysis of cadmium in open ocean seawater. Evaluation of different Cd species can generate information about distribution and speciation of Cd in the open ocean. Distribution of Cd was investigated in surface waters of the Atlantic Ocean over a wide geographical range as well as in the water column. Surface water sampling on board the research vessel Polarstern was performed from the bow boom of the ship as well as with a snorkel system which allowed continuous sample-taking. Two different Cd species could be differentiated in the voltammograms. UV-irradiation experiments allowed the identification of an inorganic and organic Cd form, the latter caused by the association between Cd and organic matter as e.g. humic substances (HS). Atlantic ocean surface seawater normally contains between 2 and 4 ng organically complexed Cd/kg and no detectable inorganic Cd. Some areas however showed readings of up to 14 ng inorganic Cd/kg in addition. Water column samples exhibited an enrichment of inorganic Cd by depth. Occurrence of inorganic Cd at the surface could be related to specific oceanographical conditions. Together with analytical results of trace metal contents in the particulate phases of surface seawater, new aspects could be established about the biogeochemical cycling of Cd in the sea. (orig.)

  8. Does Chlorination of Seawater Reverse Osmosis Membranes Control Biofouling?

    KAUST Repository

    Khan, Muhammad Tariq; Hong, Pei-Ying; Nada, Nabil; Croue, Jean Philippe

    2015-01-01

    Biofouling is the major problem of reverse osmosis (RO) membranes used for desalting seawater (SW). The use of chlorine is a conventional and common practice to control/prevent biofouling. Unlike polyamide RO membranes, cellulose triacetate (CTA) RO membranes display a high chlorine tolerance. Due to this characteristic, CTA membranes are used in most of the RO plants located in the Middle East region where the elevated seawater temperature and water quality promote the risk of membrane biofouling. However, there is no detailed study on the investigation/characterization of CTA-RO membrane fouling. In this investigation, the fouling profile of a full–scale SWRO desalination plant operating with not only continuous chlorination of raw seawater but also intermittent chlorination of CTA-RO membranes was studied. Detailed water quality and membrane fouling analyses were conducted. Profiles of microbiological, inorganic, and organic constituents of analysed fouling layers were extensively discussed. Our results clearly identified biofilm development on these membranes. The incapability of chlorination on preventing biofilm formation on SWRO membranes could be assigned to its failure in effectively reaching throughout the different regions of the permeators. This failure could have occurred due to three main factors: plugging of membrane fibers, chlorine consumption by organics accumulated on the front side fibers, or chlorine adaptation of certain bacterial populations.

  9. Liquid chromatographic determination of uranium in seawater with coulometric detection

    International Nuclear Information System (INIS)

    Maekoya, Chiaki; Takata, Yoshinori

    1980-01-01

    A method of the separation with anion-exchange chromatography and of the coulometric detection of uranium in seawater was investigated. The size of the separation column used was 9 mm in inside diameter and 100 mm in length, and strong basic anion-exchange resin (Hitachi No. 2632) of carbonate form was packed in the column. A concentrator with two mini-columns in which the same resin was packed was applied for the preconcentration of uranium in seawater containing 20 g of potassium thiocyanate and 10 ml of hydrochloric acid per liter. Good result was obtained when a mixed solution of sodium carbonate (0.12 mol/l), sodium bicarbonate (0.08 mol/l), sodium bisulfite (0.03 mol/l) and sodium chloride (0.5 mol/l) was used as an eluent for the separation of uranium from vanadium. Sodium bisulfite was of use for dropping the background current based on an electrochemical reduction of dissolved oxygen. Sodium bicarbonate acted as an eliminator of an unknown peak by its bufferise effect. The optimum working electrode potential for the detection was -1.45 V vs. ferri-ferrocyanide. The detection limit was 3.2 x 10 -10 mol (80 ngU). The coefficient of variation at 3.0 ppb was about 4% (n=5) for seawater analysis. And the analysis time was approximately 1.5 hours. (author)

  10. Selective uptake of manganese in seawater by hybrid microcapsules

    International Nuclear Information System (INIS)

    Kuzumaki, Takenori; Yan, Wu; Mimura, Hitoshi; Niibori, Yuichi

    2008-01-01

    The selective separation and recovery of low concentrated elements in seawater are very important subjects for the advancement of environmental monitoring. Selective uptake of manganese from seawater was carried out by using two kinds of microcapsules (MCs) including activated carbon (AC) and insoluble tannin (T). The adsorbents, AC and T, having affinity for manganese, were enclosed into MCs (ACMS, TMC) by sol-gel method using matrices of biopolymer (calcium alginate gel polymer, CaALG). The uptake properties and selectivity of Mn 2+ (1 ppm) for MCs were examined by batch method. Relatively large uptake percentages of Mn 2+ above 80% were obtained within 1 h, and the uptake percentage above 80% was kept at pH 3-6. The uptake order was found to be T, AC, CaALG > ACMC, TMC. The uptake of Mn 2+ decreased with increasing Na + ion concentration. This tendency depends on the swelling property of CaALG; it tends to solate in the presence of highly concentrated Na + ions. The manganese ions were adsorbed on CaALG, ACMC and TMC from seawater containing 1,000 ppm Mn 2+ . ACMC and TMC had selectivity to Mn 2+ , and, especially, the matrices of CaALG also had an excellent uptake and selectivity properties. (author)

  11. Does Chlorination of Seawater Reverse Osmosis Membranes Control Biofouling?

    KAUST Repository

    Khan, Muhammad Tariq

    2015-04-01

    Biofouling is the major problem of reverse osmosis (RO) membranes used for desalting seawater (SW). The use of chlorine is a conventional and common practice to control/prevent biofouling. Unlike polyamide RO membranes, cellulose triacetate (CTA) RO membranes display a high chlorine tolerance. Due to this characteristic, CTA membranes are used in most of the RO plants located in the Middle East region where the elevated seawater temperature and water quality promote the risk of membrane biofouling. However, there is no detailed study on the investigation/characterization of CTA-RO membrane fouling. In this investigation, the fouling profile of a full–scale SWRO desalination plant operating with not only continuous chlorination of raw seawater but also intermittent chlorination of CTA-RO membranes was studied. Detailed water quality and membrane fouling analyses were conducted. Profiles of microbiological, inorganic, and organic constituents of analysed fouling layers were extensively discussed. Our results clearly identified biofilm development on these membranes. The incapability of chlorination on preventing biofilm formation on SWRO membranes could be assigned to its failure in effectively reaching throughout the different regions of the permeators. This failure could have occurred due to three main factors: plugging of membrane fibers, chlorine consumption by organics accumulated on the front side fibers, or chlorine adaptation of certain bacterial populations.

  12. Fission product separation from seawater by electrocoagulation method

    International Nuclear Information System (INIS)

    Kitagaki, T.; Hoshino, T.; Sambommatsu, Y.; Yano, K.; Takeuchi, M.; Igarashi, T.; Suzuki, T.

    2013-01-01

    At the Fukushima Daiichi nuclear power station, seawater was urgently injected into the reactor core. Therefore a large amount of seawater containing highly radioactive fission products (FP) accumulated and its treatment has been a serious problem. FP such as Cs, Sr and I in water are generally removed by an ion exchanger such as zeolite and separated with column or chemical precipitation methods. An alternative electrocoagulation method, which efficiently separates fine particles from the liquid phase without a chemical reagent is expected to be part of a useful separation system that can reduce the amount of waste, decrease processing time and simplify the process. In this study, powdered adsorbents, such as ferrocyanide and zeolite, were added to seawater containing simulated FP, and the electrocoagulation effect with Al alloy electrodes were investigated. More than 99 % of Cs and 90 % of I were removed by potassium nickel hexacyanoferrate(II) and silver zeolite, respectively. Sedimentation was promoted by electrocoagulation and addition of an inorganic cohesion promoter further increased the sedimentation rate. Moreover, rapid dissolution reaction with heating of the aggregation substance was not observed, so the thermal risk of aqueous processing of it would be low. In addition, thermal analyses showed that the electrocoagulation process did not lead to thermal decomposition. Therefore, if the electrocoagulation method is applied to a decontamination system, it has the potential to thermally stabilize and reduce waste. (author)

  13. Influence of fuel costs on seawater desalination options

    International Nuclear Information System (INIS)

    Methnani, Mabrouk

    2007-01-01

    Reference estimates of seawater desalination costs for recent mega projects are all quoted in the range of US$0.50/m 3 . This however does not reflect the recent trends of escalating fossil fuel costs. In order to analyze the effect of these trends, a recently updated version of the IAEA Desalination Economic Evaluation Program, DEEP-3, has been used to compare fossil and nuclear seawater desalination options, under varied fuel cost and interest rate scenarios. Results presented for a gas combined-cycle and a modular high-temperature gas-cooled reactor design, show clear cost advantages for the latter, for both Multi-Effect Distillation (MED) and Reverse Osmosis (RO). Water production cost estimates for the Brayton cycle nuclear option are hardly affected by fuel costs, while combined cycle seawater desalination costs show an increase of more than 40% when fuel costs are doubled. For all cases run, the nuclear desalination costs are lower and if the current trend in fossil fuel prices continues as predicted by pessimist scenarios and the carbon tax carried by greenhouse emissions is enforced in the future, the cost advantage for nuclear desalination will be even more pronounced. Increasing the interest rate from 5 to 8% has a smaller effect than fuel cost variations. It translates into a water cost increase in the range of 10-20%, with the nuclear option being the more sensitive. (author)

  14. Corrosion of aluminum alloys in ocean thermal energy conversion seawaters

    International Nuclear Information System (INIS)

    Larsen-Basse, J.

    1984-01-01

    Aluminum alloys 5052, 3004, and Alclad 3003 and 3004 were exposed to flowing seawater at 2.44 m/s (8 fps) at the Seacoast Test Facility on Hawaii. One year data for warm surface water and three mouth data for cold water from 600 m depth are reported for free fouling, chlorinated and sponge ball cleaned conditions. All alloys pit in deep seawater, but show no pitting in warm surface water. Uniform corrosion in the warm water is initially rapid, but after 25 to 30 days the rate becomes slower and extrapolated 30 year material losses are in the 125 to 215 μm range. Chlorination at a level of 0.05 ppm for one hour per day has only a minor effect on corrosion rates, while sponge ball cleaning leads to erosion-corrosion of the Alclad surfaces and has no effect on alloy 5052. The need for additional testing in tropical seawater is discussed, as is the need for an improved understanding of the formation of inorganic scale films, their properties, and their effect on corrosion rates and heat transfer

  15. Effects of drinking desalinated seawater on cell viability and proliferation.

    Science.gov (United States)

    Macarrão, Camila Longhi; Bachi, André Luis Lacerda; Mariano, Mario; Abel, Lucia Jamli

    2017-06-01

    Desalination of seawater is becoming an important means to address the increasing scarcity of freshwater resources in the world. Seawater has been used as drinking water in the health, food, and medical fields and various beneficial effects have been suggested, although not confirmed. Given the presence of 63 minerals and trace elements in drinking desalinated seawater (63 DSW), we evaluated their effects on the behavior of tumorigenic and nontumorigenic cells through the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and annexin-V-fluorescein isothiocyanate/propidium iodide staining. Our results showed that cell viability and proliferation in the presence of 63 DSW were significantly greater than in mineral water and in the presence of fetal bovine serum in a dose-dependent manner. Furthermore, 63 DSW showed no toxic effect on murine embryonic fibroblast (NIH-3T3) and murine melanoma (B16-F10) cells. In another assay, we also showed that pre-treatment of non-adherent THP-1 cells with 63 DSW reduces apoptosis incidence, suggesting a protective effect against cell death. We conclude that cell viability and proliferation were improved by the mineral components of 63 DSW and this effect can guide further studies on health effects associated with DSW consumption.

  16. Marshes on the Move: Testing effects of seawater intrusion on ...

    Science.gov (United States)

    The Northeastern United States is a hotspot for sea level rise (SLR), subjecting coastal salt marshes to erosive loss, shifts in vegetation communities, and altered biogeochemistry due to seawater intrusion. Salt marsh plant community zonation is driven by tradeoffs in stress tolerance and interspecific interactions. As seawater inundates progressively higher marsh elevations, shifts in marsh vegetation communities landward may herald salt marsh “migration”, which could allow continuity of marsh function and ecosystem service provision. To elucidate possible effects of seawater intrusion on marsh-upland edge plant communities, a space-for-time approach was replicated at two Rhode Island salt marshes. At each site, peat blocks (0.5 m x 0.5 m x 0.5 m, n=6) with intact upland-marsh edge vegetation were transplanted downslope into the regularly-inundated mid-marsh. Procedural controls (n=3) were established at each elevation by removing and replacing peat blocks, and natural controls (n=3) consisted of undisturbed plots. During peak productivity, each plot was assessed for species composition, percent cover and average height. Results demonstrate stunting of marsh-upland edge vegetation in response to increased inundation, and the beginnings of colonization of the transplanted plots by salt marsh species. The extent of colonization differed between the two sites, suggesting that site-specific factors govern vegetation responses to increased inundation.

  17. Impact of Seawater Nonlinearities on Nordic Seas Circulation

    Science.gov (United States)

    Helber, R. W.; Wallcraft, A. J.; Shriver, J. F.

    2017-12-01

    The Nordic Seas (Greenland, Iceland, and Norwegian Seas) form an ocean basin important for Arctic-mid-latitude climate linkages. Cold fresh water from the Arctic Ocean and warm salty water from the North Atlantic Ocean meet in the Nordic Seas, where a delicate balance between temperature and salinity variability results in deep water formation. Seawater non-linearities are stronger at low temperatures and salinities making high-latitude oceans highly subject to thermbaricity and cabbeling. This presentation highlights and quantifies the impact of seawater non-linearities on the Nordic Seas circulation. We use two layered ocean circulation models, the Hybrid Coordinate Ocean Model (HYOCM) and the Modular Ocean Model version 6 (MOM6), that enable accurate representation of processes along and across density or neutral density surfaces. Different equations-of-state and vertical coordinates are evaluated to clarify the impact of seawater non-linearities. Present Navy systems, however, do not capture some features in the Nrodic Seas vertical structure. For example, observations from the Greenland Sea reveal a subsurface temperature maximum that deepens from approximately 1500 m during 1998 to 1800 m during 2005. We demonstrate that in terms of density, salinity is the largest source of error in Nordic Seas Navy forecasts, regional scale models can represent mesoscale features driven by thermobaricity, vertical coordinates are a critical issue in Nordic Sea circulation modeling.

  18. Membrane-based seawater desalination: Present and future prospects

    KAUST Repository

    Amy, Gary L.

    2016-10-20

    Given increasing regional water scarcity and that almost half of the world\\'s population lives within 100 km of an ocean, seawater represents a virtually infinite water resource. However, its exploitation is presently limited by the significant specific energy consumption (kWh/m) required by conventional desalination technologies, further exasperated by high unit costs ($/m) and environmental impacts including GHG emissions (g CO-eq/m), organism impingement/entrainment through intakes, and brine disposal through outfalls. This paper explores the state-of-the-art in present seawater desalination practice, emphasizing membrane-based technologies, while identifying future opportunities in step improvements to conventional technologies and development of emerging, potentially disruptive, technologies through advances in material science, process engineering, and system integration. In this paper, seawater reverse osmosis (RO) serves as the baseline conventional technology. The discussion extends beyond desalting processes into membrane-based salinity gradient energy production processes, which can provide an energy offset to desalination process energy requirements. The future membrane landscape in membrane-based desalination and salinity gradient energy is projected to include ultrahigh permeability RO membranes, renewable-energy driven desalination, and emerging processes including closed-circuit RO, membrane distillation, forward osmosis, pressure retarded osmosis, and reverse electrodialysis according various niche applications and/or hybrids, operating separately or in conjunction with RO.

  19. Why do local communities support or oppose seawater desalination?

    Science.gov (United States)

    Mirza Ordshahi, B.; Heck, N.; Faraola, S.; Paytan, A.; Haddad, B.; Potts, D. C.

    2016-12-01

    Freshwater shortages have become a global problem due to increasing water consumption and environmental changes which are reducing the reliability of traditional water resources. One option to address water shortages in coastal areas is the use of seawater desalination. Desalination technology is particularly valued for the production of high quality drinking water and consistent production. However, seawater desalination is controversial due to potential environmental, economic, and societal impacts and lack of public support for this water supply method. Compared to alternative potable water production methods, such as water recycling, little is known about public attitudes towards seawater desalination and factors that shape local support or rejection. Our research addresses this gap and explores variables that influence support for proposed desalination plants in the Monterey Bay region, where multiple facilities have been proposed in recent years. Data was collected via a questionnaire-based survey among a random sample of coastal residents and marine stakeholders between June-July, 2016. Findings of the study identify the influence of socio-demographic variables, knowledge about desalination, engagement in marine activities, perception of the environmental context, and the existence of a National Marine Sanctuary on local support. Research outcome provide novel insights into public attitudes towards desalination and enhances our understanding of why communities might support or reject this water supply technology.

  20. Recovery of uranium from seawater. 14. System arrangements for the recovery of uranium from seawater by spherical amidoxime chelating resins utilizing natural seawater motions

    International Nuclear Information System (INIS)

    Egawa, Hiroaki; Kabay, Nalan; Shuto, Taketomi; Jyo, Akinori

    1993-01-01

    In order to evaluate performances of lightly cross-linked highly porous amidoxime resins in uranium-adsorption systems utilizing natural seawater motions, uranium uptake by the resins from seawater was studied by different approaches, such as simulated sea current exposure tests, towing trials, and/or mooring trials. In general, the efficiency of uranium uptake became higher with a decrease in the thickness of packing layers, indicating important roles of fluidization of the resin particles. On the basis of these fundamental data, mooring tests in the natural sea current were designed and conducted. By mooring flat adsorption beds (base area 260 cm 2 , height 3.0 cm) packed with 780 ml of the resin for 40 h, promising uranium uptake as high as 44 mg/kg of resin (9.9 mg/l of resin) was achieved under sea conditions in which the velocity of sea currents and the vertical velocity of waves were 5.5-49.7 cm/s and 3.4-27 cm/s, respectively

  1. Extraction of uranium from seawater: a few facts

    Directory of Open Access Journals (Sweden)

    Guidez Joel

    2016-01-01

    Full Text Available Although uranium concentration in seawater is only about 3 micrograms per liter, the quantity of uranium dissolved in the world's oceans is estimated to amount to 4.5 billion tonnes of uranium metal (tU. In contrast, the current conventional terrestrial resource is estimated to amount to about 17 million tU. However, for a number of reasons the extraction of significant amounts of uranium from seawater remains today more a dream than a reality. Firstly, pumping the seawater to extract this uranium would need more energy than what could be produced with the recuperated uranium. Then if trying to use existing industrial flow rates, as for example on a nuclear power plant, it appears that the annual possible quantity remains very low. In fact huge quantities of water must be treated. To produce the annual world uranium consumption (around 65,000 tU, it would need at least to extract all uranium of 2 × 1013 tonnes of seawater, the volume equivalent of the entire North Sea. In fact only the great ocean currents are providing without pumping these huge quantities, and the idea is to try to extract even very partially this uranium. For example Japan, which used before the Fukushima accident about 8,000 tU by year, sees about 5.2 million tU passing every year, in the ocean current Kuro Shio in which it lies. A lot of research works have been published on the studies of adsorbents immersed in these currents. Then, after submersion, these adsorbents are chemically treated to recuperate the uranium. Final quantities remain very low in comparison of the complex and costly operations to be done in sea. One kilogram of adsorbent, after one month of submersion, yields about 2 g of uranium and the adsorbent can only be used six times due to decreasing efficiency. The industrial extrapolation exercise made for the extraction of 1,200 tU/year give with these values a very costly installation installed on more than 1000 km2 of sea with a

  2. Development of an Assessment Procedure for Seawater Intrusion Mitigation

    Science.gov (United States)

    Hsi Ting, F.; Yih Chi, T.

    2017-12-01

    The Pingtung Plain is one of the areas with extremely plentiful groundwater resources in Taiwan. Due to that the application of the water resource is restricted by significant variation of precipitation between wet and dry seasons, groundwater must be used as a recharge source to implement the insufficient surface water resource during dry seasons. In recent years, the coastal aquaculture rises, and the over withdrawn of groundwater by private well results in fast drop of groundwater level. Then it causes imbalance of groundwater supply and leads to serious seawater intrusion in the coastal areas. The purpose of this study is to develop an integrated numerical model of groundwater resources and seawater intrusion. Soil and Water Assessment Tool (SWAT), MODFLOW and MT3D models were applied to analyze the variation of the groundwater levels and salinity concentration to investigate the correlation of parameters, which are used to the model applications in order to disposal saltwater intrusion. The data of groundwater levels, pumping capacity and hydrogeological data to were collected to build an integrated numerical model. Firstly, we will collect the information of layered aquifer and the data of hydrological parameters to build the groundwater numerical model at Pingtung Plain, and identify the amount of the groundwater which flow into the sea. In order to deal with the future climate change conditions or extreme weather conditions, we will consider the recharge with groundwater model to improve the seawater intrusion problem. The integrated numerical model which describes that seawater intrusion to deep confined aquifers and shallow unsaturated aquifers. Secondly, we will use the above model to investigate the weights influenced by different factors to the amount area of seawater intrusion, and predict the salinity concentration distribution of evaluation at coastal area of Pingtung Plain. Finally, we will simulate groundwater recharge/ injection at the coastal

  3. Concentration of enteric virus indicator from seawater using granular activated carbon.

    Science.gov (United States)

    Cormier, Jiemin; Gutierrez, Miguel; Goodridge, Lawrence; Janes, Marlene

    2014-02-01

    Fecal contamination of shellfish growing seawater with enteric viruses is often associated with human outbreaks of gastroenteritis. Male specific bacteriophage MS2 is correlated with those of enteric viruses in a wide range of water environments and has been used widely as a surrogate for pathogenic waterborne viruses. Since viruses in contaminated water are usually at low levels, the development of methods to concentrate viruses from water is crucial for detection purposes. In the present study, granular activated carbon was evaluated for concentration of MS2 from artificial seawater, and different parameters of the seawater were also compared. Recovery of MS2 from warm seawater (37°C) was found to be significantly greater than from cold seawater (4 and 20°C), and even greater than from fresh water (4, 20 and 37°C); the difference between seawater and fresh water became less profound when the temperatures of both were below 37°C. Although not of statistical significance, recovery of MS2 from low salinity seawater (10 and 20 parts per thousand, ppt) was greater than from high salinity seawater (30 and 40ppt). One gram of granular activated carbon was able to extract 6-log plaque forming units (PFU) of MS2 from 500ml seawater at 37°C. This study demonstrated that granular activated carbon can concentrate an enteric virus indicator from shellfish growing seawater effectively. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Experimental study of composition and influence factors on fouling of stainless steel and copper in seawater

    International Nuclear Information System (INIS)

    Yang, Dazhang; Liu, Jianhua; E, Xiaoxue; Jiang, Linlin

    2016-01-01

    Highlights: • An increase of seawater temperature deteriorates the fouling and corrosion. • The main compositions of crystals are Mg(OH) 2 , Al(OH) 3 and their complex compounds. • The images of the seawater fouling on stainless steel and copper were shown in the paper. • A higher heat flux and A higher Reynolds number are prone to crystallization fouling accumulation in seawater. - Abstract: Metals and alloys are easily fouled in marine environment. It is a big problem for heat exchangers using cooling seawater in power plants or ships. In the paper, a seawater-fouling dynamic test device was built to investigate the composition and influence factors on fouling of stainless steel and copper in the cooling seawater system. Moreover, the static trials were performed to study the fouling and corrosion of stainless steel and copper in marine environment. The experimental results show that the seawater fouling of stainless steel is crystallization fouling, and the main elements of fouling are magnesium and aluminum. In addition, the results show that the seawater fouling of copper is corrosion fouling. In the dynamic experiments, the effects of heat flux and Reynolds number on stainless steel fouling were studied. The results show that higher heat flux and higher Reynolds number of seawater lead to the accumulation of seawater fouling.

  5. Endothelial Semaphorin 7A promotes inflammation in seawater aspiration-induced acute lung injury.

    Science.gov (United States)

    Zhang, Minlong; Wang, Li; Dong, Mingqing; Li, Zhichao; Jin, Faguang

    2014-10-28

    Inflammation is involved in the pathogenesis of seawater aspiration-induced acute lung injury (ALI). Although several studies have shown that Semaphorin 7A (SEMA7A) promotes inflammation, there are limited reports regarding immunological function of SEMA7A in seawater aspiration-induced ALI. Therefore, we investigated the role of SEMA7A during seawater aspiration-induced ALI. Male Sprague-Dawley rats were underwent seawater instillation. Then, lung samples were collected at an indicated time for analysis. In addition, rat pulmonary microvascular endothelial cells (RPMVECs) were cultured and then stimulated with 25% seawater for indicated time point. After these treatments, cells samples were collected for analysis. In vivo, seawater instillation induced lung histopathologic changes, pro-inflammation cytokines release and increased expression of SEMA7A. In vitro, seawater stimulation led to pro-inflammation cytokine release, cytoskeleton remodeling and increased monolayer permeability in pulmonary microvascular endothelial cells. In addition, knockdown of hypoxia-inducible factor (HIF)-1α inhibited the seawater induced increase expression of SEMA7A. Meanwhile, knockdown of SEMA7A by specific siRNA inhibited the seawater induced aberrant inflammation, endothelial cytoskeleton remodeling and endothelial permeability. These results suggest that SEMA7A is critical in the development of lung inflammation and pulmonary edema in seawater aspiration-induced ALI, and may be a therapeutic target for this disease.

  6. New Technologies for Seawater Desalination Using Nuclear Energy

    International Nuclear Information System (INIS)

    2015-01-01

    As seawater desalination technologies are rapidly evolving and more States are opting for dual purpose integrated power plants (i.e. cogeneration), the need for advanced technologies suitable for coupling to nuclear power plants and leading to more efficient and economic nuclear desalination systems is obvious. The Coordinated Research Programme (CRP) New Technologies for Seawater Desalination using Nuclear Energy was organized in the framework of the Technical Working Group on Nuclear Desalination (TWG-ND). The TWGND was established in 2008 with the purpose of advising the IAEA Deputy Director General and promoting the exchange of technical information on national programmes in the field of seawater desalination using nuclear energy. This CRP project was conducted within the Nuclear Power Technology Development Section of the IAEA. It was launched in 2009 and completed by 2011, with research proposals received from nine Member States: Algeria, Egypt, France, India, Indonesia, Pakistan, the Syrian Arab Republic, the United Kingdom and the United States of America. The project aimed to review innovative technologies for seawater desalination which could be coupled to main types of existing nuclear power plant. Such coupling is expected to help making nuclear desalination safer and more economical, and hence more attractive for newcomer States interested in nuclear desalination. The project also aimed to collect ideas and suggestions necessary to update the IAEA desalination economic evaluation program (DEEP) software to become more robust and versatile. The specific objectives of the project were the introduction of innovative technologies and their economic viability, which could help make nuclear desalination a globally viable option for the safe and sustainable production of fresh water. The technologies under scrutiny in this CRP involve the low temperature horizontal tube multi-effect distillation, heat recovery systems using heat pipe based heat exchangers

  7. Numerical Model of SO2 Scrubbing with Seawater Applied to Marine Engines

    Directory of Open Access Journals (Sweden)

    Lamas M. I.

    2016-04-01

    Full Text Available The present paper proposes a CFD model to study sulphur dioxide (SO2 absorption in seawater. The focus is on the treatment of marine diesel engine exhaust gas. Both seawater and distilled water were compared to analyze the effect of seawater alkalinity. The results indicate that seawater is more appropriate than distilled water due to its alkalinity, obtaining almost 100% cleaning efficiency for the conditions analyzed. This SO2 reduction meets the limits of SOx emission control areas (SECA when operating on heavy fuel oil. These numerical simulations were satisfactory validated with experimental tests. Such data are essential in designing seawater scrubbers and judging the operating cost of seawater scrubbing compared to alternative fuels.

  8. Erythropoietin Pretreatment Attenuates Seawater Aspiration-Induced Acute Lung Injury in Rats.

    Science.gov (United States)

    Ji, Mu-Huo; Tong, Jian-Hua; Tan, Yuan-Hui; Cao, Zhen-Yu; Ou, Cong-Yang; Li, Wei-Yan; Yang, Jian-Jun; Peng, Y G; Zhu, Si-Hai

    2016-02-01

    Seawater drowning-induced acute lung injury (ALI) is a serious clinical condition characterized by increased alveolar-capillary permeability, excessive inflammatory responses, and refractory hypoxemia. However, current therapeutic options are largely supportive; thus, it is of great interest to search for alternative agents to treat seawater aspiration-induced ALI. Erythropoietin (EPO) is a multifunctional agent with antiinflammatory, antioxidative, and antiapoptotic properties. However, the effects of EPO on seawater aspiration-induced ALI remain unclear. In the present study, male rats were randomly assigned to the naive group, normal saline group, seawater group, or seawater + EPO group. EPO was administered intraperitoneally at 48 and 24 h before seawater aspiration. Arterial blood gas analysis was performed with a gas analyzer at baseline, 30 min, 1 h, 4 h, and 24 h after seawater aspiration, respectively. Histological scores, computed tomography scan, nuclear factor kappa B p65, inducible nitric oxide synthase, caspase-3, tumor necrosis factor-alpha, interleukin (IL)-1β, IL-6, IL-10, wet-to-dry weight ratio, myeloperoxidase activity, malondialdehyde, and superoxide dismutase in the lung were determined 30 min after seawater aspiration. Our results showed that EPO pretreatment alleviated seawater aspiration-induced ALI, as indicated by increased arterial partial oxygen tension and decreased lung histological scores. Furthermore, EPO pretreatment attenuated seawater aspiration-induced increase in the expressions of pulmonary nuclear factor kappa B p65, inducible nitric oxide synthase, caspase-3, tumor necrosis factor-alpha, IL-1β, myeloperoxidase activity, and malondialdehyde when compared with the seawater group. Collectively, our study suggested that EPO pretreatment attenuates seawater aspiration-induced ALI by down-regulation of pulmonary pro-inflammatory cytokines, oxidative stress, and apoptosis.

  9. Behaviors and chemical forms of radionuclides in seawater

    International Nuclear Information System (INIS)

    Honda, Yoshihide

    1981-01-01

    Although the radionuclides introduced into the marine environment from various sources and routes are finally distributed among the components of the marine ecosystem, the residence time is one of the most useful measures of the reactivity of an element in the oceanic chemical system. Heavy metals such as Mn, Fe, Co and Zn which have shorter residence times, reveal more complicated behaviours in relation to marine radioecological interest than alkaline earth element such as Sr which has a longer residence time. The possible physico-chemical forms of radionuclides in the oceans are usually classified into three categories, that is, species in true solution, colloidal species, and particulate forms. The modeling to study the dispersion of radionuclides introduced into the marine environment can be approached with the aid of the knowledge of behaviors of their stable counterparts in seawater. The different physico-chemical forms between stable and radioactive nuclides in seawater may cause different biological concentration of the element. To realize the chemical speciation of radionuclides in the marine environment, it is also important in thermodynamical calculation to consider heterogeneous interfaces where cause raising the concentration of reactants in seawater, especially in the coastal waters. In the discussion on the primary factors that can affect the elemental distribution in the marine environment, primary productivity and bacterial activity are emphasized for the transformation of physicochemical states of radionuclides in the marine environment. Finally, the radioecological differences between radiocobalt in organic complexed and ionic forms were demonstrated in the experiments on the uptake and elimination of radiocobalt by mussels. (J.P.N.)

  10. Innovative Elution Processes for Recovering Uranium from Seawater

    International Nuclear Information System (INIS)

    Wai, Chien; Tian, Guoxin; Janke, Christopher

    2014-01-01

    Utilizing amidoxime-based polymer sorbents for extraction of uranium from seawater has attracted considerable interest in recent years. Uranium collected in the sorbent is recovered typically by elution with an acid. One drawback of acid elution is deterioration of the sorbent which is a significant factor that limits the economic competitiveness of the amidoxime-based sorbent systems for sequestering uranium from seawater. Developing innovative elution processes to improve efficiency and to minimize loss of sorbent capacity become essential in order to make this technology economically feasible for large-scale industrial applications. This project has evaluated several elution processes including acid elution, carbonate elution, and supercritical fluid elution for recovering uranium from amidoxime-based polymer sorbents. The elution efficiency, durability and sorbent regeneration for repeated uranium adsorption- desorption cycles in simulated seawater have been studied. Spectroscopic techniques are used to evaluate chemical nature of the sorbent before and after elution. A sodium carbonate-hydrogen peroxide elution process for effective removal of uranium from amidoxime-based sorbent is developed. The cause of this sodium carbonate and hydrogen peroxide synergistic leaching of uranium from amidoxime-based sorbent is attributed to the formation of an extremely stable uranyl peroxo-carbonato complex. The efficiency of uranium elution by the carbonate-hydrogen peroxide method is comparable to that of the hydrochloric acid elution but damage to the sorbent material is much less for the former. The carbonate- hydrogen peroxide elution also does not need any elaborate step to regenerate the sorbent as those required for hydrochloric acid leaching. Several CO2-soluble ligands have been tested for extraction of uranium from the sorbent in supercritical fluid carbon dioxide. A mixture of hexafluoroacetylacetone and tri-n-butylphosphate shows the best result but uranium

  11. A seawater desalination scheme for global hydrological models

    Science.gov (United States)

    Hanasaki, Naota; Yoshikawa, Sayaka; Kakinuma, Kaoru; Kanae, Shinjiro

    2016-10-01

    Seawater desalination is a practical technology for providing fresh water to coastal arid regions. Indeed, the use of desalination is rapidly increasing due to growing water demand in these areas and decreases in production costs due to technological advances. In this study, we developed a model to estimate the areas where seawater desalination is likely to be used as a major water source and the likely volume of production. The model was designed to be incorporated into global hydrological models (GHMs) that explicitly include human water usage. The model requires spatially detailed information on climate, income levels, and industrial and municipal water use, which represent standard input/output data in GHMs. The model was applied to a specific historical year (2005) and showed fairly good reproduction of the present geographical distribution and national production of desalinated water in the world. The model was applied globally to two periods in the future (2011-2040 and 2041-2070) under three distinct socioeconomic conditions, i.e., SSP (shared socioeconomic pathway) 1, SSP2, and SSP3. The results indicate that the usage of seawater desalination will have expanded considerably in geographical extent, and that production will have increased by 1.4-2.1-fold in 2011-2040 compared to the present (from 2.8 × 109 m3 yr-1 in 2005 to 4.0-6.0 × 109 m3 yr-1), and 6.7-17.3-fold in 2041-2070 (from 18.7 to 48.6 × 109 m3 yr-1). The estimated global costs for production for each period are USD 1.1-10.6 × 109 (0.002-0.019 % of the total global GDP), USD 1.6-22.8 × 109 (0.001-0.020 %), and USD 7.5-183.9 × 109 (0.002-0.100 %), respectively. The large spreads in these projections are primarily attributable to variations within the socioeconomic scenarios.

  12. Innovative Elution Processes for Recovering Uranium from Seawater

    Energy Technology Data Exchange (ETDEWEB)

    Wai, Chien [Univ. of Idaho, Moscow, ID (United States); Tian, Guoxin [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Janke, Christopher [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-05-29

    Utilizing amidoxime-based polymer sorbents for extraction of uranium from seawater has attracted considerable interest in recent years. Uranium collected in the sorbent is recovered typically by elution with an acid. One drawback of acid elution is deterioration of the sorbent which is a significant factor that limits the economic competitiveness of the amidoxime-based sorbent systems for sequestering uranium from seawater. Developing innovative elution processes to improve efficiency and to minimize loss of sorbent capacity become essential in order to make this technology economically feasible for large-scale industrial applications. This project has evaluated several elution processes including acid elution, carbonate elution, and supercritical fluid elution for recovering uranium from amidoxime-based polymer sorbents. The elution efficiency, durability and sorbent regeneration for repeated uranium adsorption- desorption cycles in simulated seawater have been studied. Spectroscopic techniques are used to evaluate chemical nature of the sorbent before and after elution. A sodium carbonate-hydrogen peroxide elution process for effective removal of uranium from amidoxime-based sorbent is developed. The cause of this sodium carbonate and hydrogen peroxide synergistic leaching of uranium from amidoxime-based sorbent is attributed to the formation of an extremely stable uranyl peroxo-carbonato complex. The efficiency of uranium elution by the carbonate-hydrogen peroxide method is comparable to that of the hydrochloric acid elution but damage to the sorbent material is much less for the former. The carbonate- hydrogen peroxide elution also does not need any elaborate step to regenerate the sorbent as those required for hydrochloric acid leaching. Several CO2-soluble ligands have been tested for extraction of uranium from the sorbent in supercritical fluid carbon dioxide. A mixture of hexafluoroacetylacetone and tri-n-butylphosphate shows the best result but uranium

  13. Performance and flow characteristics of MHD seawater thruster

    Energy Technology Data Exchange (ETDEWEB)

    Doss, E.D.

    1990-01-01

    The main goal of the research is to investigate the effects of strong magnetic fields on the electrical and flow fields inside MHD thrusters. The results of this study is important in the assessment of the feasibility of MHD seawater propulsion for the Navy. To accomplish this goal a three-dimensional fluid flow computer model has been developed and applied to study the concept of MHD seawater propulsion. The effects of strong magnetic fields on the current and electric fields inside the MHD thruster and their interaction with the flow fields, particularly those in the boundary layers, have been investigated. The results of the three-dimensional computations indicate that the velocity profiles are flatter over the sidewalls of the thruster walls in comparison to the velocity profiles over the electrode walls. These nonuniformities in the flow fields give rise to nonuniform distribution of the skin friction along the walls of the thrusters, where higher values are predicted over the sidewalls relative to those over the electrode walls. Also, a parametric study has been performed using the three-dimensional MHD flow model to analyze the performance of continuous electrode seawater thrusters under different operating parameters. The effects of these parameters on the fluid flow characteristics, and on the thruster efficiency have been investigated. Those parameters include the magnetic field (10--20 T), thruster diameter, surface roughness, flow velocity, and the electric load factor. The results show also that the thruster performance improves with the strength of the magnetic field and thruster diameter, and the efficiency decreases with the flow velocity and surface roughness.

  14. Seawater sulfate reduction and sulfur isotope fractionation in basaltic systems: interaction of seawater with fayalite and magnetite at 200-3500C

    International Nuclear Information System (INIS)

    Shanks, W.C. III; Bischoff, J.L.; Rosenbauer, R.J.

    1981-01-01

    Sulfate reduction during seawater reaction with fayalite and with magnetite was rapid at 350 0 C, producing equilibrium assemblages of talc-pyrite-hematite-magnetite at low water/rock ratios and talc-pyrite-hematite-anhydrite at higher water/rock ratios. At 250 0 C, seawater reacting with fayalite produced detectable amounts of dissolved H 2 S. At 200 0 C, dissolved H 2 S was not detected, even after 219 days. Reaction stoichiometry indicates that sulfate reduction requires large amounts of H + , which, in subseafloor hydrothermal systems is provided by Mg metasomatism. Seawater contains sufficient Mg to supply all the H + necessary for quantitative reduction of seawater sulfate. Systematics of sulfur isotopes in the 250 and 350 0 C experiments indicate that isotopic equilibrium is reached and can be modeled as a Rayleigh distillation process. Isotopic composition of hydrothermally produced H 2 S in natural systems is strongly dependent upon the seawater/basalt ratio in the geothermal system, which controls the relative sulfide contributions from the two important sulfur sources, seawater sulfate and sulfide phases in basalt. Anhydrite precipitation during geothermal heating severely limits sulfate ingress into high temperature interaction zones. Quantitative sulfate reduction can thus be accomplished without producing strongly oxidized rocks and resultant sulfide sulfur isotope values represent a mixture of seawater and basaltic sulfur. (author)

  15. Carbonate-H₂O₂ leaching for sequestering uranium from seawater.

    Science.gov (United States)

    Pan, Horng-Bin; Liao, Weisheng; Wai, Chien M; Oyola, Yatsandra; Janke, Christopher J; Tian, Guoxin; Rao, Linfeng

    2014-07-28

    Uranium adsorbed on amidoxime-based polyethylene fiber in simulated seawater can be quantitatively eluted at room temperature using 1 M Na2CO3 containing 0.1 M H2O2. This efficient elution process is probably due to the formation of an extremely stable uranyl-peroxo-carbonato complex in the carbonate solution. After washing with water, the sorbent can be reused with minimal loss of uranium loading capacity. Possible existence of this stable uranyl species in ocean water is also discussed.

  16. Recovery of uranium from seawater using amidoxime hollow fibers

    International Nuclear Information System (INIS)

    Saito, K.; Uezu, K.; Hori, T.; Furusaki, S.; Sugo, T.; Okamoto, J.

    1988-01-01

    A novel amidoxime-group-containing adsorbent of hollow-fiber form (AO-H fiber) was prepared by radiation-induced graft polymerization of acrylonitrile onto a polyethylene hollow fiber, followed by chemical conversion of the produced cyano group to an amidoxime group. Distribution of the amidoxime group was uniform throughout hollow-fiber membrane. The fixed-bed adsorption column, 30 cm in length and charged with the bundle of AO-H fibers, was found to adsorb uranium from natural seawater at a sufficiently high rate: 0.66 mg uranium per g of adsorbent in 25 days

  17. Results of Plutonium Intercalibration in Seawater and Seaweed Samples

    International Nuclear Information System (INIS)

    Fukai, R.; Murray, C.N.

    1976-01-01

    The results of the intercalibration exercise for the measurement of plutonium-239 and 228 in two seawater samples SW-I-1 and SW-I-2 and a marine algae sample AG-I-1 are presented. Seventeen laboratories from 8 countries as well as the IAEA International Laboratory of Marine Radioactivity took part. A discussion of the results and methods used in the analysis is given. It is concluded that in spite of the complicated chemical procedures involved in plutonium analysis, the scatter of the reported results was much smaller than that for fission product radionuclides such as strontium-90, ruthenium-106, cesium-137 etc. (author)

  18. Documentation of the seawater intrusion (SWI2) package for MODFLOW

    Science.gov (United States)

    Bakker, Mark; Schaars, Frans; Hughes, Joseph D.; Langevin, Christian D.; Dausman, Alyssa M.

    2013-01-01

    The SWI2 Package is the latest release of the Seawater Intrusion (SWI) Package for MODFLOW. The SWI2 Package allows three-dimensional vertically integrated variable-density groundwater flow and seawater intrusion in coastal multiaquifer systems to be simulated using MODFLOW-2005. Vertically integrated variable-density groundwater flow is based on the Dupuit approximation in which an aquifer is vertically discretized into zones of differing densities, separated from each other by defined surfaces representing interfaces or density isosurfaces. The numerical approach used in the SWI2 Package does not account for diffusion and dispersion and should not be used where these processes are important. The resulting differential equations are equivalent in form to the groundwater flow equation for uniform-density flow. The approach implemented in the SWI2 Package allows density effects to be incorporated into MODFLOW-2005 through the addition of pseudo-source terms to the groundwater flow equation without the need to solve a separate advective-dispersive transport equation. Vertical and horizontal movement of defined density surfaces is calculated separately using a combination of fluxes calculated through solution of the groundwater flow equation and a simple tip and toe tracking algorithm. Use of the SWI2 Package in MODFLOW-2005 only requires the addition of a single additional input file and modification of boundary heads to freshwater heads referenced to the top of the aquifer. Fluid density within model layers can be represented using zones of constant density (stratified flow) or continuously varying density (piecewise linear in the vertical direction) in the SWI2 Package. The main advantage of using the SWI2 Package instead of variable-density groundwater flow and dispersive solute transport codes, such as SEAWAT and SUTRA, is that fewer model cells are required for simulations using the SWI2 Package because every aquifer can be represented by a single layer of cells

  19. Erosion Corrosion and Protection of Recycle System with Seawater

    Directory of Open Access Journals (Sweden)

    Xue Jin

    2016-01-01

    Full Text Available In order to investigate the corrosion of recycle system with seawater in rights of power plant, the erosion behavior and mechanism of erosion corrosion in this system constructed with several corrosionresistance alloys have been studied and tested in the condition of high speed fluid with a sand particles. Both special protection technologies and results, one designed by high temperature epoxy resin powder coating and another of the associating method of anode protection together with such same coating, have been discussed as well in this case.

  20. Extraction of uranium from seawater: a few facts - 5025

    International Nuclear Information System (INIS)

    Guidez, J.; Gabriel, S.

    2015-01-01

    Although uranium concentration in seawater is only about 3 micrograms/liter, the quantity of uranium dissolved in the world's oceans is estimated to amount to 4.5 billions tonnes of uranium metal (tU). In contrast, the current conventional terrestrial resource is estimated to amount to about 17 million tU. However, for a number of reasons the extraction of significant amounts of uranium from seawater remains today more a dream than a reality. Firstly, pumping the seawater to extract this uranium would need more energy more energy than what could be produced with the recuperated uranium. Then if trying to use existing industrial flow rates, as for example on a nuclear power plant, it appears that the annual possible quantity remains very low. In fact huge quantities of water must be treated. To produce the annual world uranium consumption (around 65.000 tU), it would need at least to extract all uranium of 2*10 13 tonnes of water, the volume equivalent to the entire North Sea. In fact only the great ocean currents are providing without pumping huge quantities of seawater and the idea is to try to extract even very partially this uranium. A lot of research works have been published, on the studies of adsorbents immersed in these currents. Then, after immersion, these adsorbents are chemically treated to recuperate the uranium. Final quantities remain low in comparison of the complex and costly operations to be done in sea. One kilogram of adsorbent, after one month of immersion, yields about 2 g of uranium and the adsorbent can only be used 6 times due to decreasing efficiency. The industrial extrapolation exercise made for the extraction of 1.200 tU/year give with these values a very costly installation installed on more than 1000 km 2 of sea with a lot of boats for transportation and maintenance. The ecological management of this huge installation would present significant challenges. (authors)

  1. Uranyl peroxide enhanced nuclear fuel corrosion in seawater.

    Science.gov (United States)

    Armstrong, Christopher R; Nyman, May; Shvareva, Tatiana; Sigmon, Ginger E; Burns, Peter C; Navrotsky, Alexandra

    2012-02-07

    The Fukushima-Daiichi nuclear accident brought together compromised irradiated fuel and large amounts of seawater in a high radiation field. Based on newly acquired thermochemical data for a series of uranyl peroxide compounds containing charge-balancing alkali cations, here we show that nanoscale cage clusters containing as many as 60 uranyl ions, bonded through peroxide and hydroxide bridges, are likely to form in solution or as precipitates under such conditions. These species will enhance the corrosion of the damaged fuel and, being thermodynamically stable and kinetically persistent in the absence of peroxide, they can potentially transport uranium over long distances.

  2. Enhancement of Extraction of Uranium from Seawater – Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Dietz, Travis Cameron [Univ. of Maryland, College Park, MD (United States); Tsinas, Zois [Univ. of Maryland, College Park, MD (United States); Tomaszewski, Claire [Univ. of Maryland, College Park, MD (United States); Pazos, Ileana [Univ. of Maryland, College Park, MD (United States); Nigliazzo, Olga [University of Palermo, Palermo (Italy); Li, Weixing [Univ. of Maryland, College Park, MD (United States); Adel-Hadadi, Mohammad [Univ. of Maryland, College Park, MD (United States); Barkatt, Aaron [The Catholic Univ. of America, Washington, DC (United States); Al-Sheikhly, Mohamad [Univ. of Maryland, College Park, MD (United States)

    2016-05-16

    Even at a concentration of 3 μg/L, the world’s oceans contain a thousand times more uranium than currently know terrestrial sources. In order to take advantage of this stockpile, methods and materials must be developed to extract it efficiently, a difficult task considering the very low concentration of the element and the competition for extraction by other atoms in seawater such as sodium, calcium, and vanadium. The majority of current research on methods to extract uranium from seawater are vertical explorations of the grafting of amidoxime ligand, which was originally discovered and promoted by Japanese studies in the late 1980s. Our study expands on this research horizontally by exploring the effectiveness of novel uranium extraction ligands grafted to the surface of polymer substrates using radiation. Through this expansion, a greater understanding of uranium binding chemistry and radiation grafting effects on polymers has been obtained. While amidoxime-functionalized fabrics have been shown to have the greatest extraction efficiency so far, they suffer from an extensive chemical processing step which involves treatment with powerful basic solutions. Not only does this add to the chemical waste produced in the extraction process and add to the method’s complexity, but it also significantly impacts the regenerability of the amidoxime fabric. The approach of this project has been to utilize alternative, commercially available monomers capable of extracting uranium and containing a carbon-carbon double bond to allow it to be grafted using radiation, specifically phosphate, oxalate, and azo monomers. The use of commercially available monomers and radiation grafting with electron beam or gamma irradiation will allow for an easily scalable fabrication process once the technology has been optimized. The need to develop a cheap and reliable method for extracting uranium from seawater is extremely valuable to energy independence, and will extend the quantity of

  3. Prospects for the extraction of uranium from seawater

    Energy Technology Data Exchange (ETDEWEB)

    Vernon, F; Cameron, H; Georghiou, L

    1982-10-01

    Current discussions of the long-term prospects for the nuclear power industry centre on disagreements over energy demand forecasts, and on social, political and enviromental issues. The availability of adequate uranium supplies is also necessary for any expansion of generating capacity, and for consideration of possible fast breeder reactor strategies. This paper outlines some of the factors which will determine the viability of one non-conventional source of uranium, and comments on work currently being undertaken at the Universities of Salford and Manchester into exploitation of uranium resources in seawater.

  4. Control and Modelling of Seawater Desalination Using Solar Technology

    Energy Technology Data Exchange (ETDEWEB)

    Roca, L.; Yebra, L. J.; Berenguel, M.; Alarcon, D. C.

    2006-07-01

    Desalination plants play a fundamental role in fighting the shortage of fresh water in places with plentiful seawater resources. This paper briefly describes a solar desalination system designed, erected and operated in the AQUASOL project at the Plataforma Solar de Almeria (PSA), consisting basically of a CPC (Compound Parabolic Concentrator) solar collector field, two water storage tanks, a multi-effect distillation plant (MED) and a Double Effect Absorption Heat Pump (DEAHP). These subsystems have been modeled to estimate system behaviour and develop control techniques for maintaining optimal operating conditions. (Author)

  5. Enhancement of Extraction of Uranium from Seawater - Final Report

    International Nuclear Information System (INIS)

    Dietz, Travis Cameron; Tsinas, Zois; Tomaszewski, Claire; Pazos, Ileana; Nigliazzo, Olga; Li, Weixing; Adel-Hadadi, Mohammad; Barkatt, Aaron; Al-Sheikhly, Mohamad

    2016-01-01

    Even at a concentration of 3 μg/L, the world's oceans contain a thousand times more uranium than currently know terrestrial sources. In order to take advantage of this stockpile, methods and materials must be developed to extract it efficiently, a difficult task considering the very low concentration of the element and the competition for extraction by other atoms in seawater such as sodium, calcium, and vanadium. The majority of current research on methods to extract uranium from seawater are vertical explorations of the grafting of amidoxime ligand, which was originally discovered and promoted by Japanese studies in the late 1980s. Our study expands on this research horizontally by exploring the effectiveness of novel uranium extraction ligands grafted to the surface of polymer substrates using radiation. Through this expansion, a greater understanding of uranium binding chemistry and radiation grafting effects on polymers has been obtained. While amidoxime-functionalized fabrics have been shown to have the greatest extraction efficiency so far, they suffer from an extensive chemical processing step which involves treatment with powerful basic solutions. Not only does this add to the chemical waste produced in the extraction process and add to the method's complexity, but it also significantly impacts the regenerability of the amidoxime fabric. The approach of this project has been to utilize alternative, commercially available monomers capable of extracting uranium and containing a carbon-carbon double bond to allow it to be grafted using radiation, specifically phosphate, oxalate, and azo monomers. The use of commercially available monomers and radiation grafting with electron beam or gamma irradiation will allow for an easily scalable fabrication process once the technology has been optimized. The need to develop a cheap and reliable method for extracting uranium from seawater is extremely valuable to energy independence, and will extend the

  6. Study of corrosion behavior of carbon steel under seawater film using the wire beam electrode method

    International Nuclear Information System (INIS)

    Liu, Zaijian; Wang, Wei; Wang, Jia; Peng, Xin; Wang, Yanhua; Zhang, Penghui; Wang, Haijie; Gao, Congjie

    2014-01-01

    Corrosion behavior of carbon steel under seawater film with various thickness was investigated by the wire beam electrode (WBE) method. It was found that the corrosion rate of carbon steel increased significantly under thin seawater film than it was immersed in seawater. The current variation under seawater film indicated that the thickness of diffusion layer of oxygen was about 500 μm, and the maximal current appeared around 40 μm, at which corrosion rate transited from cathodic control to anodic control. The results suggest that WBE method is helpful to study the corrosion process under thin electrolyte film

  7. Factors affecting seawater-based pretreatment of lignocellulosic date palm residues

    DEFF Research Database (Denmark)

    Fang, Chuanji; Thomsen, Mette Hedegaard; Frankaer, Christian Grundahl

    2017-01-01

    Seawater-based pretreatment of lignocellulosic biomass is an innovative process at research stage. With respect to process optimization, factors affecting seawater-based pretreatment of lignocellulosic date palm residues were studied for the first time in this paper. Pretreatment temperature (180...... °C–210 °C), salinity of seawater (0 ppt–50 ppt), and catalysts (H2SO4, Na2CO3, and NaOH) were investigated. The results showed that pretreatment temperature exerted the largest influence on seawater-based pretreatment in terms of the enzymatic digestibility and fermentability of pretreated solids...

  8. Hydrochemical and isotopic characteristics of estuarial seawater and river water of Bailanghe in Laizhou Bay, China

    Science.gov (United States)

    Yang, Qiaofeng; Xu, Suning; Wang, Ruijiu; Li, Wenpeng; Wang, Zhiyi; Mei, Junjun; Ding, Zhilei; Yang, Peijie; Yu, Liangju; Lv, Tieying; Bai, Gang; Kang, Wei

    2016-04-01

    In the study of seawater intrusion, seawater is usually taken as an end-member that mixes with other source(s). However, compared to standard seawater, the coastal seawater particularly that near the estuary, can be strongly influenced by the rivers into the sea and by coastal human activities. Their composition can be thus continuously changed and redistributed with space and time. Therefore, before investigating seawater intrusion in a certain area, it is essentially important to determine the features of the estuarine seawater (e.g. the mixture percentage between standard seawater and river water). In this study, we aimed to gain a clear situation of the seawater intrusion in Laizhou Bay, Southern Bohai, China. The issue aforementioned was investigated by comparing the stable isotopic and hydrochemical composition of the marine and river water collected in this area. Samples investigated include 5 surface water samples collected at the downstream of the Bailanghe and 7 seawater samples near the estuary of Laizhou Bay. Inert tracers (δD, δ18O, Cl, Br) and reaction tracers (Na, Mg, SO4, HCO3, Ca, NO3) are particularly analyzed. The major results are as follows: 1) All the river water samples fall below the Global Meteoric Water Line in the δD - δ18O diagram, reflecting evaporation of the upstream reservoir water. The seawater samples fall on the mixing line of standard seawater and the river water in the stable isotopic diagram. 2) The Cl-δ18O diagram indicates widespread dissolution of evaporate into the river, while high concentration of Ca and HCO3-, as well as the SO42- - Cl relation of the river water samples reflect the dissolution of CO2 , carbonate and sulfate in the atmosphere and on the ground. 3) The Br/Cl ratios of seawater samples are closed to the marine ratios. This together with the plots of major ions vs. Cl suggest that the seawater samples are originated from the mixture of standard seawater and river water. Therefore, when referring to the

  9. One-dimensional self-sealing ability of bentonites in artificial seawater

    International Nuclear Information System (INIS)

    Komine, Hideo; Yasuhara, Kazuya; Murakami, Satoshi

    2009-01-01

    A high-level radioactive waste disposal facility might be built in a coastal area in Japan from the viewpoint of feasible transportation of waste. Therefore, it is important to investigate the effects of seawater on a bentonite-based buffer. This study investigated the influence of seawater on self-sealing ability of three common sodium-types of bentonite by the laboratory experiment and chemical analysis. From the results of laboratory experiment, suitable specifications were defined for a bentonite-based buffer that can withstand the effects of seawater. Furthermore, mechanism on filtration of seawater components in highly compacted bentonite was discussed by the results of chemical analysis. (author)

  10. Investigating the Crevice Corrosion Behavior of Coated Stainless Steel in Seawater

    National Research Council Canada - National Science Library

    Kain, Robert

    2000-01-01

    .... austenitic stainless steel. Testing in natural seawater has demonstrated that coatings can protect susceptible stainless steel from barnacle related crevice corrosion and localized corrosion at weldments...

  11. Standardization of solvent extraction procedure for determination of uranium in seawater

    International Nuclear Information System (INIS)

    Sukanta Maity; Sahu, S.K.; Pandit, G.G.

    2015-01-01

    Solvent extraction procedure using ammonium pyrolidine dithiocarbamate complexing agent in methyl isobutyl ketone organic phase and acid exchange back-extraction is described for the simultaneous quantitative pre-concentration of uranium in seawater followed by its determination by differential pulse adsorptive stripping voltammetry. Solvent extraction time is optimized for extraction of uranium from seawater. Solvent extraction efficiency for uranium in seawater at different pH was carried out. The method gives a recovery of 98 ± 2 % for 400 mL sample at pH 3.0 ± 0.02, facilitating the rapid and interference free analysis of seawater samples. (author)

  12. assessment of Seawater Intrusion in Concrete by Measuring Chlorine Concentration

    International Nuclear Information System (INIS)

    Abdel-Monem, A.M.; Kansouh, W.A.; Osman, A.M.; Bashter, I.I.

    2011-01-01

    The object of this work is to measure water intrusion in concrete using a new methodology based on neutron activation technique. The applied method depends on measuring the activated gamma energy lines emitted from 38 Cl using a gamma spectrometer with Ge(Li) and HPGe detectors. Concrete samples with different percentages of silica fume (SF), up to 20 % submerged in seawater for different period of time were used to perform the investigation. Samples of concrete taken from different positions along the direction of water intrusion in concrete block were irradiated by thermal neutrons using the irradiation cell of 252 Cf neutron source and one of the vertical channels of search reactor at Delft University. The measured 38 Cl concentrations of the irradiated samples were used to plot groups of water profiles distribution in concrete samples with different SF % and submerged in seawater for different periods. These profiles were compared with the others which use here measured by neutron back emitted method where a satisfactory agreement was observed between the two. Further, the displayed measured results; show that the diffusivity for all water contents decreases with increasing the silica fume percentage up to 15 %. However, for concrete samples with silica fume 20 % the observed phenomenon is reversed due to the deterioration of concrete physical and mechanical properties

  13. Desalination of seawater with nuclear power reactors in cogeneration

    International Nuclear Information System (INIS)

    Flores E, R.M.

    2004-01-01

    The growing demand for energy and hydraulic resources for satisfy the domestic, industrial, agricultural activities, etc. has wakened up the interest to carry out concerning investigations to study the diverse technologies guided to increase the available hydraulic resources, as well as to the search of alternatives of electric power generation, economic and socially profitable. In this sense the possible use of the nuclear energy is examined in cogeneration to obtain electricity and drinkable water for desalination of seawater. The technologies are analysed involved in the nuclear cogeneration (desalination technology, nuclear and desalination-nuclear joining) available in the world. At the same time it is exemplified the coupling of a nuclear reactor and a process of hybrid desalination that today in day the adult offers and economic advantages. Finally, the nuclear desalination is presented as a technical and economically viable solution in regions where necessities of drinkable water are had for the urban, agricultural consumption and industrial in great scale and that for local situations it is possible to satisfy it desalinating seawater. (Author)

  14. Fatigue crack growth in welded joints in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, S.B.

    1988-01-01

    A pipe-to-plate specimen has been developed to study the influence of seawater on the fatigue behaviour of welded tubular joints. DC potential drop techniques have been used to detect fatigue crack initiation, and to monitor the subsequent growth of fatigue cracks. Results for three specimens, tested in air are compared with similar data for tubular and T-plate joints. These comparisons indicate that the pipe/plate is a reasonable model of a tubular joint. Testing was performed on a further six specimens in artificial seawater; two each with free corrosion, optimum cathodic protection, and cathodic overprotection. Fatigue life reduction factors compared with corresponding tests in air were 1.8 and 2.8 for free corrosion, 1.7 and 1.1 with cathodic protection, and 4.2 and 3.3 with cathodic over-protection. These fatigue life reduction factors were comparable to results on T-plate specimens, and were strongly dependent on crack shape development. Linear elastic fracture mechanics techniques appear suitable for the calculation of fatigue crack propagation life. Three approximate solution techniques for crack tip stress intensity factors show reasonable agreement with experimentally derived values. It is recommended that forcing functions be used to model crack aspect ratio development in welded joints. Such forcing functions are influenced by the initial stress distribution and the environment. 207 refs., 192 figs., 22 tabs.

  15. Dissolution of basaltic glass in seawater: Mechanism and rate

    International Nuclear Information System (INIS)

    Crovisier, J.L.; Honnorez, J.; Eberhart, J.P.

    1987-01-01

    Basaltic glasses are considered as natural analogues for nuclear waste glasses. Thermodynamic computer codes used to evaluate long term behavior of both nuclear waste and basaltic glasses require the knowledge of the dissolution mechanism of the glass network. The paper presents the results of a series of experiments designed to study the structure and chemical composition of alteration layers formed on the surface of artificial tholeiitic glass altered in artificial seawater. Experiments were performed at 60 degree C, 1 bar and 350 bars in non-renewed conditions. A natural sample from Palagonia (Sicily) has been studied by electron microscopy and comparison between natural and experimental palagonitic layers is made. The behavior of dissolved silica during experiments, and both the structure and the chemical composition of the palagonitic layers, indicate that they form by precipitation of secondary minerals from solution after a total breakdown of the glassy network, i.e., congruent dissolution of the glass. Hence the dissolution equation necessary for thermodynamic modelling of basaltic glass dissolution in seawater at low temperature must be written as a simple stoichiometric process. These experiments indicate that the transformation of glass to palagonitic material is not isovolumetric. Hence it is preferable to use Fe or Ti as conservative elements for chemical budget calculations

  16. A Method for Seawater Desalination via Squeezing Ionic Hydrogels.

    Science.gov (United States)

    Yu, Chi; Wang, Yanhong; Lang, Xuemei; Fan, Shuanshi

    2016-12-06

    In this study, mechanical force applied to squeeze poly(sodium acrylate-co-2-hydroxyethyl methacrylate) hydrogels that contained seawater in order to obtain fresh water. By incorporating ionic monomer sodium acrylate (SA) into hydrogels, the salt rejection was significantly enhanced from 27.62% to 64.57% (feed concentration 35.00g/L NaCl solution). As SA's concentration continuously increased, salt rejection declined due to the change in hydrogel's matrix structure. Therefore, water recovery raised as the current swelling degree increased. We also measured pore size distribution by applying mercury intrusion porosimetry on each hydrogel sample in the interest of finding out whether the sample SA5/HEMA15 owned multi pore structure, since the result could be good for the desalination performance. After 4 times reused, the hydrogel remained good desalination performance. Although compared to reverse osmosis (RO) and multistage flash distillation (MSF) & multiple effect distillation (MED) the salt rejection of this hydrogel (roughly 64%) seemed low, the hydrogels can be used for forward osmosis and reverse osmosis, as pretreatment of seawater to reduce the energy consumption for the downstream.

  17. Seawater reverse osmosis desalination and (harmful) algal blooms

    KAUST Repository

    Villacorte, Loreen O.; Tabatabai, S. Assiyeh Alizadeh; Anderson, Donald M.; Amy, Gary L.; Schippers, Jan Cornelis; Kennedy, Maria Dolores

    2015-01-01

    This article reviews the occurrence of HABs in seawater, their effects on the operation of seawater reverse osmosis (SWRO) plants, the indicators for quantifying/predicting these effects, and the pretreatment strategies for mitigating operational issues during algal blooms. The potential issues in SWRO plants during HABs are particulate/organic fouling of pretreatment systems and biological fouling of RO membranes, mainly due to accumulation of algal organic matter (AOM). The presence of HAB toxins in desalinated water is also a potential concern but only at very low concentrations. Monitoring algal cell density, AOM concentrations and membrane fouling indices is a promising approach to assess the quality of SWRO feedwater and performance of the pretreatment system. When geological condition is favourable, subsurface intake can be a robust pretreatment for SWRO during HABs. Existing SWRO plants with open intake and are fitted with granular media filtration can improve performance in terms of capacity and product water quality, if preceded by dissolved air flotation or sedimentation. However, the application of advanced pretreatment using ultrafiltration membrane with in-line coagulation is often a better option as it is capable of maintaining stable operation and better RO feed water quality during algal bloom periods with significantly lower chemical consumption.

  18. Mechanical cleaning of oil spills in seawater using circular conduits

    Energy Technology Data Exchange (ETDEWEB)

    Shedid, S.; Abou Kassem, J.; Zekri, A. [United Arab Emirates Univ., Al Ain City (United Arab Emirates). Dept. of Chemical and Petroleum Engineering

    2005-10-15

    Treatment of the crude oil pollution in seawater has attracted global attention during the last two decades. This study was undertaken using circular conduits as a mechanical means to clean oil spills in seawater under different conditions of temperature, oil gravity, shaking frequency, conduit diameter, and initial thickness of oil layer. An experimental model was designed and built to achieve the study. It consists of shaking water bath (to represent sea waves) fitted with temperature controller and glass tubes of different inside diameters of 0.3 cm, 0.5 cm, and 0.7 cm. Three crude oils of different oil gravity of 35{sup o}API, 38{sup o}API, and 47{sup o}API were investigated under different shaking frequencies of 20, 40, and 60 stroke/minute with different tube diameters. The results proved that application of mechanical cleaning of oil spills using circular conduits is a practical technique. The cleaning of black oil spills is more efficient than one of volatile oil. Furthermore, the results indicated that the increase of shaking frequency and/or water temperature provide(s) faster cleaning of oil spills while temperature increase recovers the maximum oil. (Author)

  19. Metrological traceability of carbon dioxide measurements in atmosphere and seawater

    International Nuclear Information System (INIS)

    Rolle, F; Pessana, E; Sega, M

    2017-01-01

    The accurate determination of gaseous pollutants is fundamental for the monitoring of the trends of these analytes in the environment and the application of the metrological concepts to this field is necessary to assure the reliability of the measurement results. In this work, an overview of the activity carried out at Istituto Nazionale di Ricerca Metrologica to establish the metrological traceability of the measurements of gaseous atmospheric pollutants, in particular of carbon dioxide (CO 2 ), is presented. Two primary methods, the gravimetry and the dynamic dilution, are used for the preparation of reference standards for composition which can be used to calibrate sensors and analytical instrumentation. At present, research is carried out to lower the measurement uncertainties of the primary gas mixtures and to extend their application to the oceanic field. The reason of such investigation is due to the evidence of the changes occurring in seawater carbonate chemistry, connected to the rising level of CO 2 in the atmosphere. The well established activity to assure the metrological traceability of CO 2 in the atmosphere will be applied to the determination of CO 2 in seawater, by developing suitable reference materials for calibration and control of the sensors during their routine use. (paper)

  20. Seawater reverse osmosis desalination and (harmful) algal blooms

    KAUST Repository

    Villacorte, Loreen O.

    2015-03-01

    This article reviews the occurrence of HABs in seawater, their effects on the operation of seawater reverse osmosis (SWRO) plants, the indicators for quantifying/predicting these effects, and the pretreatment strategies for mitigating operational issues during algal blooms. The potential issues in SWRO plants during HABs are particulate/organic fouling of pretreatment systems and biological fouling of RO membranes, mainly due to accumulation of algal organic matter (AOM). The presence of HAB toxins in desalinated water is also a potential concern but only at very low concentrations. Monitoring algal cell density, AOM concentrations and membrane fouling indices is a promising approach to assess the quality of SWRO feedwater and performance of the pretreatment system. When geological condition is favourable, subsurface intake can be a robust pretreatment for SWRO during HABs. Existing SWRO plants with open intake and are fitted with granular media filtration can improve performance in terms of capacity and product water quality, if preceded by dissolved air flotation or sedimentation. However, the application of advanced pretreatment using ultrafiltration membrane with in-line coagulation is often a better option as it is capable of maintaining stable operation and better RO feed water quality during algal bloom periods with significantly lower chemical consumption.

  1. Comparative study of economic competitive for nuclear seawater desalination

    International Nuclear Information System (INIS)

    Tian Li; Wang Yongqing

    2001-01-01

    The method of levelized discounted production water cost and the new desalination economic evaluation program (DEEP1.1) are used. Many cases of seawater desalination by nuclear energy or fossil energy combined with reverse osmosis (RO), Multi-effect distillation (MED) or multi-stage flash (MSF) technology in south-east Asia is performed and their economic competitive is analyzed. Their results indicate, the nuclear desalination plants have stronger economic competitive comparing to the fossil in the RO, MED and MSF technology. The desalination water cost is very changeable depending on the difference of desalination technology and water plant size. Its range is 0.56 dollar · m -3 - 1.89 dollar · m -3 , the lowest desalination water cost is product by RO and the highest is by MSF. The sensitive factors of the economic competitive are orderly the discounted rate, desalination plant size, seawater temperature and total dissolved solids (TDS), fossil fuel price and specific power plant investment. The highest rate of water cost is about 19.3% comparing to base case

  2. Full utilization of silt density index (SDI) measurements for seawater pre-treatment

    KAUST Repository

    Wei, Chunhai

    2012-07-01

    In order to clarify the fouling mechanism during silt density index (SDI) measurements of seawater in the seawater reverse osmosis (SWRO) desalination process, 11 runs were conducted under constant-pressure (207kPa) dead-end filtration mode according to the standard protocol for SDI measurement, in which two kinds of 0.45μm membranes of different material and seawater samples from the Mediterranean including raw seawater and seawater pre-treated by coagulation followed by sand filtration (CSF) and coagulation followed by microfiltration (CMF) technologies were tested. Fouling mechanisms based on the constant-pressure filtration equation were fully analyzed. For all runs, only t/(V/A)∼t showed very good linearity (correlation coefficient R 2>0.99) since the first moment of the filtration, indicating that standard blocking rather than cake filtration was the dominant fouling mechanism during the entire filtration process. The very low concentration of suspended solids rejected by MF of 0.45μm in seawater was the main reason why a cake layer was not formed. High turbidity removal during filtration indicated that organic colloids retained on and/or adsorbed in membrane pores governed the filtration process (i.e., standard blocking) due to the important contribution of organic substances to seawater turbidity in this study. Therefore the standard blocking coefficient k s, i.e., the slope of t/(V/A)∼t, could be used as a good fouling index for seawater because it showed good linearity with feed seawater turbidity. The correlation of SDI with k s and feed seawater quality indicated that SDI could be reliably used for seawater with low fouling potential (SDI 15min<5) like pre-treated seawater in this study. From both k s and SDI, the order of fouling potential was raw seawater>seawater pre-treated by CSF>seawater pre-treated by CMF, indicating the better performance of CMF than CSF. © 2012 Elsevier B.V.

  3. Mercury isotope signatures of seawater discharged from a coal-fired power plant equipped with a seawater flue gas desulfurization system.

    Science.gov (United States)

    Lin, Haiying; Peng, Jingji; Yuan, Dongxing; Lu, Bingyan; Lin, Kunning; Huang, Shuyuan

    2016-07-01

    Seawater flue gas desulfurization (SFGD) systems are commonly used to remove acidic SO2 from the flue gas with alkaline seawater in many coastal coal-fired power plants in China. However, large amount of mercury (Hg) originated from coal is also transferred into seawater during the desulfurization (De-SO2) process. This research investigated Hg isotopes in seawater discharged from a coastal plant equipped with a SFGD system for the first time. Suspended particles of inorganic minerals, carbon residuals and sulfides are enriched in heavy Hg isotopes during the De-SO2 process. δ(202)Hg of particulate mercury (PHg) gradually decreased from -0.30‰ to -1.53‰ in study sea area as the distance from the point of discharge increased. The results revealed that physical mixing of contaminated De-SO2 seawater and uncontaminated fresh seawater caused a change in isotopic composition of PHg isotopes in the discharging area; and suggested that both De-SO2 seawater and local background contributed to PHg. The impacted sea area predicted with isotopic tracing technique was much larger than that resulted from a simple comparison of pollutant concentration. It was the first attempt to apply mercury isotopic composition signatures with two-component mixing model to trace the mercury pollution and its influence in seawater. The results could be beneficial to the coal-fired plants with SFGD systems to assess and control Hg pollution in sea area. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. A reactive transport investigation of a seawater intrusion experiment in a shallow aquifer, Skansehage Denmark

    DEFF Research Database (Denmark)

    Christensen, Flemming Damgaard; Engesgaard, Peter Knudegaard; Kipp, K.L.

    2001-01-01

    Previous investigations on seawater intrusion have mainly focused on either the physical density flow system with transport of a single non-reactive species or focused on the geochemical aspects neglecting density effects. This study focuses on both the geochemical and physical aspects of seawate...

  5. Predatory bacteria as natural modulators of Vibrio parahaemolyticus and Vibrio vulnificus in seawater and oysters

    Science.gov (United States)

    This study shows that naturally occurring Vibrio predatory bacteria (VPB) exert a major role in controlling pathogenic vibrios in seawater and shellfish. The growth and persistence of Vibrio parahaemolyticus (Vp) and Vibrio vulnificus (Vv) were assessed in natural seawater and in the Eastern oyster...

  6. Predicting and measurement of pH of seawater reverse osmosis concentrates

    KAUST Repository

    Waly, Tarek; Kennedy, Maria Dolores; Witkamp, Geert-Jan; Amy, Gary L.; Schippers, Jan Cornelis

    2011-01-01

    The pH of seawater reverse osmosis plants (SWRO) is the most influential parameter in determining the degree of supersaturation of CaCO3 in the concentrate stream. For this, the results of pH measurements of the concentrate of a seawater reverse

  7. Role of bacteria in marine barite precipitation : A case study using Mediterranean seawater

    NARCIS (Netherlands)

    Torres-Crespo, N.; Martínez-Ruiz, F.; González-Muñoz, M. T.; Bedmar, E. J.; De Lange, G. J.; Jroundi, F.

    2015-01-01

    Marine bacteria isolated from natural seawater were used to test their capacity to promote barite precipitation under laboratory conditions. Seawater samples were collected in the western and eastern Mediterranean at 250. m and 200. m depths, respectively, since marine barite formation is thought to

  8. Development of an environmental impact assessment and decision support system for seawater desalination plants

    NARCIS (Netherlands)

    Lattemann, S.

    2010-01-01

    Seawater desalination is a rapidly growing coastal-based industry. The combined production capacity of all seawater desalination plants worldwide has increased by 30% over the last two years: from 28 million cubic meters per day in 2007—which is the equivalent of the average discharge of the River

  9. Intensively exploited Mediterranean aquifers: resilience to seawater intrusion and proximity to critical thresholds

    Science.gov (United States)

    Mazi, K.; Koussis, A. D.; Destouni, G.

    2014-05-01

    We investigate seawater intrusion in three prominent Mediterranean aquifers that are subject to intensive exploitation and modified hydrologic regimes by human activities: the Nile Delta, Israel Coastal and Cyprus Akrotiri aquifers. Using a generalized analytical sharp interface model, we review the salinization history and current status of these aquifers, and quantify their resilience/vulnerability to current and future seawater intrusion forcings. We identify two different critical limits of seawater intrusion under groundwater exploitation and/or climatic stress: a limit of well intrusion, at which intruded seawater reaches key locations of groundwater pumping, and a tipping point of complete seawater intrusion up to the prevailing groundwater divide of a coastal aquifer. Either limit can be reached, and ultimately crossed, under intensive aquifer exploitation and/or climate-driven change. We show that seawater intrusion vulnerability for different aquifer cases can be directly compared in terms of normalized intrusion performance curves. The site-specific assessments show that (a) the intruding seawater currently seriously threatens the Nile Delta aquifer, (b) in the Israel Coastal aquifer the sharp interface toe approaches the well location and (c) the Cyprus Akrotiri aquifer is currently somewhat less threatened by increased seawater intrusion.

  10. Global Cr-isotope distributions in surface seawater and incorporation of Cr isotopes into carbonate shells

    DEFF Research Database (Denmark)

    Paulukat, Cora Stefanie; Frei, Robert; Vögelin, Andrea Regula

    produced carbonate shells (bivalves, gastropods) and corals. Our preliminary data set ranges approximately from d53Cr = -0.2 to +0.7‰. They are isotopically lighter than local seawater. This is in good agreement with [6], who measured a negative offset from seawater in corals. These offsets indicate some...

  11. Impact of seawater [Ca2+] on the calcification and calcite Mg / Ca of Amphistegina lessonii

    NARCIS (Netherlands)

    Mewes, A.; Langer, G.; Thoms, S.; Nehrke, G.; Reichart, G. J.; de Nooijer, L. J.; Bijma, J.

    2015-01-01

    Mg / Ca ratios in foraminiferal tests are routinely used as paleotemperature proxies, but on long timescales, they also hold the potential to reconstruct past seawater Mg / Ca. The impact of both temperature and seawater Mg / Ca on Mg incorporation in Foraminifera has been quantified by a number of

  12. Seasonal levels of the Vibrio predator Bacteriovorax in Atlantic, Pacific and Gulf Coast Seawater

    Science.gov (United States)

    Bacteriovorax were quantified in US Atlantic, Gulf and Pacific seawater to determine baseline levels of these predatory bacteria and possible seasonal fluctuations in levels. Surface seawater was analyzed monthly for 1 year from Kailua-Kona, Hawaii; the Gulf Coast of Alabama; and four sites along t...

  13. Seawater mesocosm experiments in the Arctic uncover differential transfer of marine bacteria to aerosols.

    Science.gov (United States)

    Fahlgren, Camilla; Gómez-Consarnau, Laura; Zábori, Julia; Lindh, Markus V; Krejci, Radovan; Mårtensson, E Monica; Nilsson, Douglas; Pinhassi, Jarone

    2015-06-01

    Biogenic aerosols critically control atmospheric processes. However, although bacteria constitute major portions of living matter in seawater, bacterial aerosolization from oceanic surface layers remains poorly understood. We analysed bacterial diversity in seawater and experimentally generated aerosols from three Kongsfjorden sites, Svalbard. Construction of 16S rRNA gene clone libraries from paired seawater and aerosol samples resulted in 1294 sequences clustering into 149 bacterial and 34 phytoplankton operational taxonomic units (OTUs). Bacterial communities in aerosols differed greatly from corresponding seawater communities in three out of four experiments. Dominant populations of both seawater and aerosols were Flavobacteriia, Alphaproteobacteria and Gammaproteobacteria. Across the entire dataset, most OTUs from seawater could also be found in aerosols; in each experiment, however, several OTUs were either selectively enriched in aerosols or little aerosolized. Notably, a SAR11 clade OTU was consistently abundant in the seawater, but was recorded in significantly lower proportions in aerosols. A strikingly high proportion of colony-forming bacteria were pigmented in aerosols compared with seawater, suggesting that selection during aerosolization contributes to explaining elevated proportions of pigmented bacteria frequently observed in atmospheric samples. Our findings imply that atmospheric processes could be considerably influenced by spatiotemporal variations in the aerosolization efficiency of different marine bacteria. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  14. Distribution of lead-210 and polonium-210 between soluble and particulate phases in seawater

    International Nuclear Information System (INIS)

    Spencer, D.W.

    1975-01-01

    Results are reported from radiometric measurements of the distribution of 210 Pb and 210 Po in surface seawater and suspended particulate matter. Samples of plankton and sediments collected from some locations were also analyzed. Samples of seawater and suspended particulate matter were collected from stations located in the Gulf of Maine, the North Atlantic, and approximately 500 miles southwest of Gilbraltar. (U.S.)

  15. Fast concentration of dissolved forms of cesium radioisotopes from large seawater samples

    International Nuclear Information System (INIS)

    Jan Kamenik; Henrieta Dulaiova; Ferdinand Sebesta; Kamila St'astna; Czech Technical University, Prague

    2013-01-01

    The method developed for cesium concentration from large freshwater samples was tested and adapted for analysis of cesium radionuclides in seawater. Concentration of dissolved forms of cesium in large seawater samples (about 100 L) was performed using composite absorbers AMP-PAN and KNiFC-PAN with ammonium molybdophosphate and potassium–nickel hexacyanoferrate(II) as active components, respectively, and polyacrylonitrile as a binding polymer. A specially designed chromatography column with bed volume (BV) 25 mL allowed fast flow rates of seawater (up to 1,200 BV h -1 ). The recovery yields were determined by ICP-MS analysis of stable cesium added to seawater sample. Both absorbers proved usability for cesium concentration from large seawater samples. KNiFC-PAN material was slightly more effective in cesium concentration from acidified seawater (recovery yield around 93 % for 700 BV h -1 ). This material showed similar efficiency in cesium concentration also from natural seawater. The activity concentrations of 137 Cs determined in seawater from the central Pacific Ocean were 1.5 ± 0.1 and 1.4 ± 0.1 Bq m -3 for an offshore (January 2012) and a coastal (February 2012) locality, respectively, 134 Cs activities were below detection limit ( -3 ). (author)

  16. Temporal Patterns in Seawater Quality from Dredging in Tropical Environments.

    Directory of Open Access Journals (Sweden)

    Ross Jones

    Full Text Available Maintenance and capital dredging represents a potential risk to tropical environments, especially in turbidity-sensitive environments such as coral reefs. There is little detailed, published observational time-series data that quantifies how dredging affects seawater quality conditions temporally and spatially. This information is needed to test realistic exposure scenarios to better understand the seawater-quality implications of dredging and ultimately to better predict and manage impacts of future projects. Using data from three recent major capital dredging programs in North Western Australia, the extent and duration of natural (baseline and dredging-related turbidity events are described over periods ranging from hours to weeks. Very close to dredging i.e. <500 m distance, a characteristic features of these particular case studies was high temporal variability. Over several hours suspended sediment concentrations (SSCs can range from 100-500 mg L-1. Less turbid conditions (10-80 mg L-1 can persist over several days but over longer periods (weeks to months averages were <10 mg L-1. During turbidity events all benthic light was sometimes extinguished, even in the shallow reefal environment, however a much more common feature was very low light 'caliginous' or daytime twilight periods. Compared to pre-dredging conditions, dredging increased the intensity, duration and frequency of the turbidity events by 10-, 5- and 3-fold respectively (at sites <500 m from dredging. However, when averaged across the entire dredging period of 80-180 weeks, turbidity values only increased by 2-3 fold above pre-dredging levels. Similarly, the upper percentile values (e.g., P99, P95 of seawater quality parameters can be highly elevated over short periods, but converge to values only marginally above baseline states over longer periods. Dredging in these studies altered the overall probability density distribution, increasing the frequency of extreme values. As

  17. Determination of 226Ra and 228Ra in surface seawater around Sagami bay and its vicinity

    International Nuclear Information System (INIS)

    Nakano-Ohta, T.; Kubota, T.; Mahara, Y.; Yoshikawa, M.; Sato, J.

    2006-01-01

    Activity ratios of 228 Ra/ 226 Ra in surface seawaters were observed at 5 ports of Izu-Oshima, Ajiro port of Sagami bay and Umizuri park of Tokyo bay. The 228 Ra/ 226 Ra activity ratio in surface seawaters were from 0.2 to 0.7 for Izu-Oshima, from 0.2 to 0.7 for Ajiro port and from 0.6 to 0.8 for Tokyo bay. The activity ratio in surface seawaters of Izu-Oshima and Atami of Sagami bay showed lower in spring and highly in autumn, while narrow variation pattern was observed in Umizuri park of Tokyo bay. The observed variation patterns of 228 Ra/ 226 Ra in surface seawaters at Izu-oshima, Ajiro park and Umizuri park may be reflected by difference of contribution from amount of seawater far off coast with low 228 Ra concentration. (author)

  18. Effectiveness of KNIFC-PAN Resin in Absorbing Radiocesium in Seawater

    International Nuclear Information System (INIS)

    Nurrul Assyikeen Mohd Jaffary; Abdul Kadir Ishak; Zal Uyun Wan Mahmood; Wo, Y.M.; Norfaizal Mohamed; Mohd Tarmizi Ishak

    2016-01-01

    The effectiveness of KNiFC-PAN absorber, potassium-nickel hexacyanoferrate (II) (KNiFC) bound into modified polyacrylonitrile (PAN) have been tested for capability in absorbing radiocesium in seawater samples. The efficiency of the KNiFC-PAN were measured by the different activity of the radiocesium measured using Hyper Pure Germanium Detector (HPGe) in initial spiked seawater and eluent seawater after passed through 5 ml of KNiFC absorber. Study showed 87 % effectiveness of the KNiFC-PAN in absorbing radiocesium. Further study conducted to illustrate relation between spiked seawater and activity measured for 5 ml of KniFC passed through spiked seawater in packed column. This study suggested this relative 15L cubitainer method can be used to monitor the radiocesium in emergency situation for the fast and reliable result. (author)

  19. Seawater infiltration effect on thermal degradation of fiber reinforced epoxy composites

    Science.gov (United States)

    Ibrahim, Mohd Haziq Izzuddin bin; Hassan, Mohamad Zaki bin; Ibrahim, Ikhwan; Rashidi, Ahmad Hadi Mohamed; Nor, Siti Fadzilah M.; Daud, Mohd Yusof Md

    2018-05-01

    Seawater salinity has been associated with the reduction of polymer structure durability. The aim of this study is to investigate the change in thermal degradation of fiber reinforced epoxy composite due to the presence of seawater. Carbon fiber, carbon/kevlar, fiberglass, and jute that reinforced with epoxy resin was laminated through hand-layup technique. Initially, these specimen was sectioned to 5×5 mm dimension, then immersed in seawater and distilled water at room temperature until it has thoroughly saturated. Following, the thermal degradation analysis using Differential Scanning Calorimetry (DSC), the thermic changes due to seawater infiltration was defined. The finding shows that moisture absorption reduces the glass transition temperature (Tg) of fiber reinforced epoxy composite. However, the glass transition temperature (Tg) of seawater infiltrated laminate composite is compareable with distilled water infiltrated laminate composite. The carbon fiber reinfored epoxy has the highest glass transition temperature out of all specimen.

  20. Formation of emerging DBPs from the chlorination and chloramination of seawater algal organic matter and related model compounds

    KAUST Repository

    Nihemaiti, Maolida

    2014-01-01

    Limited studies focused on reactions occurring during disinfection and oxidation processes of seawater. The aim of this work was to investigate disinfection by-products (DBPs) formation from the chlorination and chloramination of seawater algal

  1. Removal of tributyltin from contaminated seawater by combinations of photolytic and TiO2 mediated photocatalytic processes

    DEFF Research Database (Denmark)

    Muff, Jens; Simonsen, Morten Enggrob; Søgaard, Erik Gydesen

    2017-01-01

    Harbour sediment contaminated with tributyltin (TBT) is a worldwide problem and treatment of TBT contaminated seawater is an issue during dredging operations. This study presents results from photolytic and photocatalytic treatment experiments where the influence of the seawater matrix, different...

  2. Technical feasibility of a seabed gallery seawater intake at Ras Abu Ali Island, Arabian Gulf, Saudi Arabia

    KAUST Repository

    Rachman, Rinaldi; Missimer, Thomas M.

    2014-01-01

    high quality raw seawater even before pretreatment. Subsurface intakes extract seawater indirectly through the geological structure of shoreline or nearshore sediments. Water percolation through geological units provides physical and biological

  3. Seawater immersion aggravates burn-associated lung injury and inflammatory and oxidative-stress responses.

    Science.gov (United States)

    Ma, Jun; Wang, Ying; Wu, Qi; Chen, Xiaowei; Wang, Jiahan; Yang, Lei

    2017-08-01

    With the increasing frequency of marine development activities and local wars at sea, the incidence of scald burns in marine accidents or wars has been increasing yearly. Various studies have indicated that immersion in seawater has a systemic impact on some organs of animals or humans with burn. Thus, for burn/scald injuries after immersion in seawater, it is desirable to study the effects and mechanisms of action on important organs. In the present study, we aimed to investigate the effect of immersion in seawater on lung injury, inflammatory and oxidative-stress responses in scalded rats. The structural damage to lungs was detected by hematoxylin and eosin staining and the results showed that seawater immersion aggravated structural lung injury in scalded rats. The expression of HMGB1 in lung tissues was detected by immunohistochemical analysis and the results showed that seawater immersion increased HMGB1 expression in lung tissues of scalded rats. Apoptosis in lung tissues was detected by terminal deoxynucleotidyl transfer-mediated dUTP nick end-labeling (TUNEL) staining and the results showed that seawater immersion increased apoptosis rate in lung tissues of scalded rats. In addition, the expression levels of TNF-α, IL-6, IL-8, SOD, and MDA in serum were analyzed by enzyme-linked immunosorbent assays (ELISAs) and the results showed that seawater immersion induced secretion of proinflammatory factors (TNF-α, IL-6, and IL-8), increased MDA protein level, and suppressed SOD activity in the serum of scalded rats. Furthermore, measurement of plasma volume and pH showed that seawater immersion decreased plasma volume and pH value. Overall, the results indicated that all effects induced by immersion in seawater in scalded rats are more pronounced than those induced by freshwater. In conclusion, seawater immersion may aggravate lung injury and enhance inflammatory and oxidative-stress responses after burn. Copyright © 2017 Elsevier Ltd and ISBI. All rights

  4. Thermodynamical research of using solar energy for desalination of seawater

    Directory of Open Access Journals (Sweden)

    Arsović Marjan R.

    2015-01-01

    Full Text Available Many regions of the world face the problem of saline water. Water desalination processes, which require significant energy consumption, are a common solution to produce drinking water. This study evaluated the influence of the following process operational parameters on the energy consumption of seawater RO systems: water salinity, permeate recovery ratio, membrane performance and feed water temperature. Optimal operational conditions for the theoretical minimum energy consumption were determined with experiments by varying water qualities and operational parameters. In order to further reduce energy consumption a RO system was integrated with a PV solar system and a pilot PVRO system was built and tested. The results obtained from this study indicated that even though a Solar PV system incurs a huge initial capital investment, it will yield significant benefits in the long run of the RO operational period.

  5. Economic competitiveness of seawater desalinated by nuclear and fossil energy

    International Nuclear Information System (INIS)

    Tian Li; Wang Yongqing; Guo Jilin; Liu Wei

    2001-01-01

    The levelized discounted production water cost method and the new desalination economic evaluation program (DEEP1.1) were used to compare the economics of desalination using nuclear or fossil energy. The results indicate that nuclear desalination is more economic than fossil desalination with reverse osmosis (RO), multi-effect distillation (MED) and multi-stage flash (MSF). The desalination water cost varies depending on the desalination technology and the water plant size from 0.52-1.98 USD·m -3 with the lowest water price by RO and the highest by MSF. The sensitivity factors for the economic competitiveness increases in order of the discounted rate, desalination plant scale, fossil fuel price, specific power plant investment, seawater temperature and total dissolve solid (TDS). The highest water cost is about 22.6% more than the base case

  6. The seawater desalination needs of Tunisia after the year 2010

    International Nuclear Information System (INIS)

    Ben-Kraiem, H.

    2000-01-01

    The supply of drinking water for north and central Tunisia is guaranteed from surface water resources in the north and other subsurface resources. These resources will satisfy the water demand in this region until the year 2010 and 100000 m 3 /d by the year 2015. In the south of Tunisia, the water supply comes from local subsurface resources, including the lake water of the chotts. Maximum exploitation of these lakes, whose average salinity exceeds 2 g/l, has already been reached. Therefore, non-conventional resources such as desalination have become unavoidable if the water quality is to be improved and the resources are to be maximized. The needs of this region will reach 80000 m 3 /d by the year 2010. This deficit can only be met by the desalination of seawater. At present, about 60000 m 3 /d of water is desalinated in the country using the reverse osmosis process and electric energy. (author)

  7. Wireless Sensor Node for Surface Seawater Density Measurements

    Directory of Open Access Journals (Sweden)

    Roberto Saletti

    2012-03-01

    Full Text Available An electronic meter to measure surface seawater density is presented. It is based on the measurement of the difference in displacements of a surface level probe and a weighted float, which according to Archimedes’ law depends on the density of the water. The displacements are simultaneously measured using a high-accuracy magnetostrictive sensor, to which a custom electronic board provides a wireless connection and power supply so that it can become part of a wireless sensor network. The electronics are designed so that different kinds of wireless networks can be used, by simply changing the wireless module and the relevant firmware of the microcontroller. Lastly, laboratory and at-sea tests are presented and discussed in order to highlight the functionality and the performance of a prototype of the wireless density meter node in a Bluetooth radio network. The experimental results show a good agreement of the values of the calculated density compared to reference hydrometer readings.

  8. Wireless sensor node for surface seawater density measurements.

    Science.gov (United States)

    Baronti, Federico; Fantechi, Gabriele; Roncella, Roberto; Saletti, Roberto

    2012-01-01

    An electronic meter to measure surface seawater density is presented. It is based on the measurement of the difference in displacements of a surface level probe and a weighted float, which according to Archimedes' law depends on the density of the water. The displacements are simultaneously measured using a high-accuracy magnetostrictive sensor, to which a custom electronic board provides a wireless connection and power supply so that it can become part of a wireless sensor network. The electronics are designed so that different kinds of wireless networks can be used, by simply changing the wireless module and the relevant firmware of the microcontroller. Lastly, laboratory and at-sea tests are presented and discussed in order to highlight the functionality and the performance of a prototype of the wireless density meter node in a Bluetooth radio network. The experimental results show a good agreement of the values of the calculated density compared to reference hydrometer readings.

  9. Corrosion fatigue of high strength fastener materials in seawater

    Science.gov (United States)

    Tipton, D. G.

    1983-12-01

    Environmental effects which significantly reduce the fatigue life of metals are discussed. Corrosion fatigue is a major concern in the engineering application of high strength fasteners in marine environments. The corrosion fatigue failure of an AISI 41L4O high strength steel blade to hub attachment bolt at the MOD-OA 200 kW wind turbine generator was investigated. The reduction of fatigue strength of AISI 41L4O in marine environments and to obtain similar corrosion fatigue data for candidate replacement materials was studied. The AISI 4140, PH 13-8Mo stainless steel, alloy 718 and alloy MP-35N were tested in axial fatigue at a frequency of 20 Hz in dry air and natural seawater. The fatigue data are fitted by regression equations to allow determination of fatigue strength for a given number of cycles to failure.

  10. Cl-36 in polar ice, rainwater and seawater

    Science.gov (United States)

    Finkel, R. C.; Nishiizumi, K.; Elmore, D.; Ferraro, R. D.; Gove, H. E.

    1980-01-01

    Concentrations of the cosmogenic radioisotope Cl-36 in Antarctic ice, rain, and an upper limit of the seawater value are determined using van de Graaff accelerator high energy mass spectrometry. Cl-36 concentrations in Antarctic ice range between 2.5 to 8.7 x 10 to the 6th atoms Cl-36/kg, while those concentrations in samples collected at the Alan Hills ice field locations where meteorites have been brought to the surface by glacial flow and ablation are found to vary by more than a factor of three. This variation is attributed either to the effects of atmospheric mixing and scavenging or to radioactive decay in old ice. The Cl-36 concentration found in a present sample of rainwater is much lower than that reported in samples collected in the early 1960's, suggesting the occurrence of a decrease in the concentration of atmospheric Cl-36 derived from nuclear weapons tests over this time period.

  11. Cathodic properties of different stainless steels in natural seawater

    International Nuclear Information System (INIS)

    Johnsen, R.; Bardal, E.

    1985-01-01

    The cathodic properties of a number of stainless steels, which were exposed to natural seawater flowing at 0 to 2.5 m/s and polarized to potentials from -300 to -950 mV SCE, have been studied. The current density development at constant potential and the free corrosion potential during the exposure time were recorded continuously. At the end of the exposure period, after approximately 28 to 36 days of exposure, polarization curves were determined. After one to three weeks of exposure, depending on the water velocity, microbiological activity on the surface caused an increase in the current density requirement of the specimen. An explanation for the mechanism behind the current density increase caused by slime production from marine bacteria may be increased exchange current density, i 0 . There was no measurable calcareous deposit on the stainless steel surfaces at the end of the exposure periods

  12. Modeling shoreline bioremediation: Continuous flow and seawater exchange columns

    International Nuclear Information System (INIS)

    Ramstad, S.; Sveum, P.; Bech, C.; Faksness, L.G.

    1995-01-01

    This paper describes the design and use of the columns in the study of bioremediation processes, and gives some results from an experiment designed to study the effects of different additives (fish meal, stick water, and Max Bac) on biodegradation of crude oil. There is significant difference in oil degradation(nC 17 /pristane ratio) between the column with additives and those without. Open system models in this type of open column give valuable data o how the chemical and biological parameters, including oil degradation, are affected by the additives, and simultaneously by the dilutive effect of seawater washing through the sediment, and for optimizing formulations. The system is designed with a large number of units and provides a good first approximation for mesocosm studies and field experiments, thus reducing the need for large numbers of such resource-demanding experiments

  13. Uptake of technetium from seawater by red abalone Haliotis rufescens

    International Nuclear Information System (INIS)

    Spies, R.B.

    1975-01-01

    Technetium accumulation from seawater by the abalone Haliotis rufescens was studied with 95 Tc. Concentration factors, uptake rates, steady state concentrations, and biological half-lives were determined experimentally for whole-body uptake. Whole-body concentration factors ranged from 135 to 205; biological half-life was 60 days. Changes in concentration factors were determined for six tissues during the uptake period. The highest activities were in the order of: digestive gland>gill>kidneys>heart>gonad>columnar muscle. Dead shells accumulated little activity compared to shells of living abalone. Gills and digestive system appear to be the routes of entry. Autoradiography shows that of the muscular tissues the outer edge of the foot and epipodium are the most active and the edible columnar muscle the least active. (author)

  14. Effects of seawater acidification on a coral reef meiofauna community

    Science.gov (United States)

    Sarmento, V. C.; Souza, T. P.; Esteves, A. M.; Santos, P. J. P.

    2015-09-01

    Despite the increasing risk that ocean acidification will modify benthic communities, great uncertainty remains about how this impact will affect the lower trophic levels, such as members of the meiofauna. A mesocosm experiment was conducted to investigate the effects of water acidification on a phytal meiofauna community from a coral reef. Community samples collected from the coral reef subtidal zone (Recife de Fora Municipal Marine Park, Porto Seguro, Bahia, Brazil), using artificial substrate units, were exposed to a control pH (ambient seawater) and to three levels of seawater acidification (pH reductions of 0.3, 0.6, and 0.9 units below ambient) and collected after 15 and 30 d. After 30 d of exposure, major changes in the structure of the meiofauna community were observed in response to reduced pH. The major meiofauna groups showed divergent responses to acidification. Harpacticoida and Polychaeta densities did not show significant differences due to pH. Nematoda, Ostracoda, Turbellaria, and Tardigrada exhibited their highest densities in low-pH treatments (especially at the pH reduction of 0.6 units, pH 7.5), while harpacticoid nauplii were strongly negatively affected by low pH. This community-based mesocosm study supports previous suggestions that ocean acidification induces important changes in the structure of marine benthic communities. Considering the importance of meiofauna in the food web of coral reef ecosystems, the results presented here demonstrate that the trophic functioning of coral reefs is seriously threatened by ocean acidification.

  15. Aragonite coating solutions (ACS) based on artificial seawater

    International Nuclear Information System (INIS)

    Tas, A. Cuneyt

    2015-01-01

    Graphical abstract: - Highlights: • Developed completely inorganic solutions for the deposition of monolayers of aragonite spherules (or ooids). • Solutions mimicked the artificial seawater. • Biomimetic crystallization was performed at the tropical sea surface temperature of 30 °C. - Abstract: Aragonite (CaCO 3 , calcium carbonate) is an abundant biomaterial of marine life. It is the dominant inorganic phase of coral reefs, mollusc bivalve shells and the stalactites or stalagmites of geological sediments. Inorganic and initially precipitate-free aragonite coating solutions (ACS) of pH 7.4 were developed in this study to deposit monolayers of aragonite spherules or ooids on biomaterial (e.g., UHMWPE, ultrahigh molecular weight polyethylene) surfaces soaked in ACS at 30 °C. The ACS solutions of this study have been developed for the surface engineering of synthetic biomaterials. The abiotic ACS solutions, enriched with calcium and bicarbonate ions at different concentrations, essentially mimicked the artificial seawater composition and started to deposit aragonite after a long (4 h) incubation period at the tropical sea surface temperature of 30 °C. While numerous techniques for the solution deposition of calcium hydroxyapatite (Ca 10 (PO 4 ) 6 (OH) 2 ), of low thermodynamic solubility, on synthetic biomaterials have been demonstrated, procedures related to the solution-based surface deposition of high solubility aragonite remained uncommon. Monolayers of aragonite ooids deposited at 30 °C on UHMWPE substrates soaked in organic-free ACS solutions were found to possess nano-structures similar to the mortar-and-brick-type botryoids observed in biogenic marine shells. Samples were characterized using SEM, XRD, FTIR, ICP-AES and contact angle goniometry

  16. Kinetics of Inorganic Calcite Dissolution in Seawater under Pressure

    Science.gov (United States)

    Dong, S.; Subhas, A.; Rollins, N.; Berelson, W.; Adkins, J. F.

    2016-02-01

    While understanding calcium carbonate dissolution is vital in constructing global carbon cycles and predicting the effect of seawater acidification as a result of increasing atmospheric CO2, there is still a major debate over the basic formulation of a dissolution rate law. The kinetics of calcium carbonate dissolution are typically described by the equation: Rate=k(1-Ω)n, while Ω=[Ca2+][CO32-]/Ksp. In this study, 13C-labeled calcite is dissolved in unlabeled seawater and the evolving d13C composition of the fluid is traced over time to establish dissolution rate. Instead of changing ion concentration to obtain varying Ω (as in our previous study; Subhas et al. 2015), we changed Ksp by conducting experiments under different pressures (described in theory as ∂lnKsp/∂P=-ΔV/RT, where ΔV is partial molal volume). This involved the construction of a pressure vessel that could hold our sample bag and provide aliquots while remaining pressurized. Pressure experiments were conducted between 0-2000PSI. Results support the conclusion in our previous study that near-equilibrium dissolution rates are highly nonlinear, but give a disparate relationship between undersaturation and dissolution rate if Ω is calculated assuming the specific ΔV embedded in CO2SYS. A revised ΔV from -37cm3 to -65cm3 would make the dissolution formulation equation agree, but clearly appears unreasonable. Our results are explained by a pressure effect on carbonate dissolution kinetics over and above the influence of pressure on Ω. If this is a phenomenon that occurs in nature, then we would predict that dissolution should be occurring shallower in the water column (as sometimes observed) than indicated by standard Ω calculations.

  17. Responses to high seawater temperatures in zooxanthellate octocorals.

    Science.gov (United States)

    Sammarco, Paul W; Strychar, Kevin B

    2013-01-01

    Increases in Sea Surface Temperatures (SSTs) as a result of global warming have caused reef-building scleractinian corals to bleach worldwide, a result of the loss of obligate endosymbiotic zooxanthellae. Since the 1980's, bleaching severity and frequency has increased, in some cases causing mass mortality of corals. Earlier experiments have demonstrated that zooxanthellae in scleractinian corals from three families from the Great Barrier Reef, Australia (Faviidae, Poritidae, and Acroporidae) are more sensitive to heat stress than their hosts, exhibiting differential symptoms of programmed cell death - apoptosis and necrosis. Most zooxanthellar phylotypes are dying during expulsion upon release from the host. The host corals appear to be adapted or exapted to the heat increases. We attempt to determine whether this adaptation/exaptation occurs in octocorals by examining the heat-sensitivities of zooxanthellae and their host octocoral alcyonacean soft corals - Sarcophyton ehrenbergi (Alcyoniidae), Sinularia lochmodes (Alcyoniidae), and Xenia elongata (Xeniidae), species from two different families. The soft coral holobionts were subjected to experimental seawater temperatures of 28, 30, 32, 34, and 36°C for 48 hrs. Host and zooxanthellar cells were examined for viability, apoptosis, and necrosis (in hospite and expelled) using transmission electron microscopy (TEM), fluorescent microscopy (FM), and flow cytometry (FC). As experimental temperatures increased, zooxanthellae generally exhibited apoptotic and necrotic symptoms at lower temperatures than host cells and were expelled. Responses varied species-specifically. Soft coral hosts were adapted/exapted to higher seawater temperatures than their zooxanthellae. As with the scleractinians, the zooxanthellae appear to be the limiting factor for survival of the holobiont in the groups tested, in this region. These limits have now been shown to operate in six species within five families and two orders of the Cnidaria

  18. Responses to high seawater temperatures in zooxanthellate octocorals.

    Directory of Open Access Journals (Sweden)

    Paul W Sammarco

    Full Text Available Increases in Sea Surface Temperatures (SSTs as a result of global warming have caused reef-building scleractinian corals to bleach worldwide, a result of the loss of obligate endosymbiotic zooxanthellae. Since the 1980's, bleaching severity and frequency has increased, in some cases causing mass mortality of corals. Earlier experiments have demonstrated that zooxanthellae in scleractinian corals from three families from the Great Barrier Reef, Australia (Faviidae, Poritidae, and Acroporidae are more sensitive to heat stress than their hosts, exhibiting differential symptoms of programmed cell death - apoptosis and necrosis. Most zooxanthellar phylotypes are dying during expulsion upon release from the host. The host corals appear to be adapted or exapted to the heat increases. We attempt to determine whether this adaptation/exaptation occurs in octocorals by examining the heat-sensitivities of zooxanthellae and their host octocoral alcyonacean soft corals - Sarcophyton ehrenbergi (Alcyoniidae, Sinularia lochmodes (Alcyoniidae, and Xenia elongata (Xeniidae, species from two different families. The soft coral holobionts were subjected to experimental seawater temperatures of 28, 30, 32, 34, and 36°C for 48 hrs. Host and zooxanthellar cells were examined for viability, apoptosis, and necrosis (in hospite and expelled using transmission electron microscopy (TEM, fluorescent microscopy (FM, and flow cytometry (FC. As experimental temperatures increased, zooxanthellae generally exhibited apoptotic and necrotic symptoms at lower temperatures than host cells and were expelled. Responses varied species-specifically. Soft coral hosts were adapted/exapted to higher seawater temperatures than their zooxanthellae. As with the scleractinians, the zooxanthellae appear to be the limiting factor for survival of the holobiont in the groups tested, in this region. These limits have now been shown to operate in six species within five families and two orders of

  19. Aragonite coating solutions (ACS) based on artificial seawater

    Energy Technology Data Exchange (ETDEWEB)

    Tas, A. Cuneyt, E-mail: c_tas@hotmail.com

    2015-03-01

    Graphical abstract: - Highlights: • Developed completely inorganic solutions for the deposition of monolayers of aragonite spherules (or ooids). • Solutions mimicked the artificial seawater. • Biomimetic crystallization was performed at the tropical sea surface temperature of 30 °C. - Abstract: Aragonite (CaCO{sub 3}, calcium carbonate) is an abundant biomaterial of marine life. It is the dominant inorganic phase of coral reefs, mollusc bivalve shells and the stalactites or stalagmites of geological sediments. Inorganic and initially precipitate-free aragonite coating solutions (ACS) of pH 7.4 were developed in this study to deposit monolayers of aragonite spherules or ooids on biomaterial (e.g., UHMWPE, ultrahigh molecular weight polyethylene) surfaces soaked in ACS at 30 °C. The ACS solutions of this study have been developed for the surface engineering of synthetic biomaterials. The abiotic ACS solutions, enriched with calcium and bicarbonate ions at different concentrations, essentially mimicked the artificial seawater composition and started to deposit aragonite after a long (4 h) incubation period at the tropical sea surface temperature of 30 °C. While numerous techniques for the solution deposition of calcium hydroxyapatite (Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}), of low thermodynamic solubility, on synthetic biomaterials have been demonstrated, procedures related to the solution-based surface deposition of high solubility aragonite remained uncommon. Monolayers of aragonite ooids deposited at 30 °C on UHMWPE substrates soaked in organic-free ACS solutions were found to possess nano-structures similar to the mortar-and-brick-type botryoids observed in biogenic marine shells. Samples were characterized using SEM, XRD, FTIR, ICP-AES and contact angle goniometry.

  20. Perturbations of modeling and forecast of karachi coastal region seawater

    International Nuclear Information System (INIS)

    Hussain, M.A.; Abbas, S.; Ansari, M.R.K.; Zaffar, A.

    2013-01-01

    Global warming is now a stark reality affecting the humanity in many hazardous ways. Continuous floods in Pakistan in past two years are an eye opener in this regard. A great loss of property, agriculture and life as a result of these floods suggests for an intelligent monitoring of the future projections of climate change and global warming. This is necessary because the harmful impacts of natural hazards can be coped and alleviated with a good planning in advance. This monitoring demands for enhanced forecasting capabilities, use of better analytical techniques and a clear determination and study of the controlling factors. Karachi is a coastal city which is also the industrial hub of Pakistan. Moreover, it is among one of the largest metropolitans of the world. So expectedly is most suitable for the study of high level of complex natural and anthropogenic activities. It is peculiar in the sense that it has two summer seasons, a situation scarcely observable on the globe. Here, summer season seawater temperature fluctuations are studied with the help of Seasonal Autoregressive Integrated Moving Average (SARIMA) models and short- and long-term forecasts are made. Our short-term forecasts determine months for the summer wise temperature extremes. It appears that the months of May, June, July and August are the months of extreme temperature for the first summer and October is the month of extreme temperature for the second summer. The long-term forecasts predict that 2014, 2016, 2018, and 2019 will be the years of warm summers. The analysis appearing here would be useful for coastal-urban planners in emphasizing the impact of seawater extreme temperatures on urban industrial activities, etc. (author)

  1. 238U, 234U and 232Th in seawater

    International Nuclear Information System (INIS)

    Chen, J.H.; Edwards, R.L.; Wasserburg, G.J.

    1986-01-01

    We have developed techniques to determine 238 U, 234 U and 232 Th concentrations in seawater by isotope dilution mass spectrometry. Using these techniques, we have measured 238 U, 234 U and 232 Th in vertical profiles of unfiltered, acidified seawater from the Atlantic and 238 U and 234 U in vertical profiles from the Pacific. Determinations of 234 U/ 238 U at depths ranging from 0 to 4900 m in the Atlantic (7 0 44'N, 40 0 43'W) and the Pacific (14 0 41'N, 160 0 01'W) Oceans are the same within experimental error (±5per mille, 2σ). The average of these 234 U/ 238 U measurements is 144±2per mille (2σ) higher than the equilibrium ratio of 5.472 x 10 -5 . U concentrations, normalized to 35per mille salinity, range from 3.162 to 3.281 ng/g, a range of 3.8%. The average concentration of the Pacific samples (31 0 4'N, 159 0 1'W) is ∝1% higher than that of the Atlantic (7 0 44'N, 40 0 43'W and 31 0 49'N, 64 0 6'W). 232 Th concentrations from an Atlantic profile range from 0.092 to 0.145 pg/g. The observed constancy of the 234 U/ 238 U ratio is consistent with the predicted range of 234 U/ 238 U using a simple two-box model and the residence time of deep water in the ocean determined from 14 C. The variation in salinity-normalized U concentrations suggests that U may be much more reactive in the marine environment than previously thought. (orig./WB)

  2. Reasons for the Fast Growing Seawater Desalination Capacity in Algeria

    KAUST Repository

    Drouiche, Nadjib

    2011-05-24

    Seawater/brackish water desalination has been widely adopted by the Algerian Government in the last few years to supply potable water to municipality for various purposes mainly for domestic and industrial uses especially in areas where demand is high due to shortage of fresh water resources, rapid population growth and development of industry and tourism. Ten years ago, desalination was confined to the industrial use only especially in oil and gas industry as the country was relying on rain water and other available sources to supply fresh water to municipalities. Due to chronic drought conditions, the Ministry of Water Resources reviewed the national water strategy and a strong option for desalination was adopted where an ambitious program was thus put into action. Sixteen mega-plants, with capacities ranging from 100,000 to 500,000 m3 per day, primarily based on Reverse Osmosis technology, were launched in the last few years making the Algerian desalination program one of the world\\'s fastest growing markets. Five desalination plants, including the Africa\\'s largest seawater reverse osmosis project with a total capacity of 200,000 m3 per day, are already in operation and the remaining projects are either under construction or in commissioning. An integrated water resources management was also adopted as additional option to cuter the increasing water demand as there is also a great potential for water reuse and conventional water treatment. An additional benefit of this would be reducing the volume of treated wastewater disposed into the environment. © 2011 Springer Science+Business Media B.V.

  3. Estimates of ikaite export from sea ice to the underlying seawater in a sea ice–seawater mesocosm

    Directory of Open Access Journals (Sweden)

    N.-X. Geilfus

    2016-09-01

    Full Text Available The precipitation of ikaite and its fate within sea ice is still poorly understood. We quantify temporal inorganic carbon dynamics in sea ice from initial formation to its melt in a sea ice–seawater mesocosm pool from 11 to 29 January 2013. Based on measurements of total alkalinity (TA and total dissolved inorganic carbon (TCO2, the main processes affecting inorganic carbon dynamics within sea ice were ikaite precipitation and CO2 exchange with the atmosphere. In the underlying seawater, the dissolution of ikaite was the main process affecting inorganic carbon dynamics. Sea ice acted as an active layer, releasing CO2 to the atmosphere during the growth phase, taking up CO2 as it melted and exporting both ikaite and TCO2 into the underlying seawater during the whole experiment. Ikaite precipitation of up to 167 µmolkg−1 within sea ice was estimated, while its export and dissolution into the underlying seawater was responsible for a TA increase of 64–66 µmolkg−1 in the water column. The export of TCO2 from sea ice to the water column increased the underlying seawater TCO2 by 43.5 µmolkg−1, suggesting that almost all of the TCO2 that left the sea ice was exported to the underlying seawater. The export of ikaite from the ice to the underlying seawater was associated with brine rejection during sea ice growth, increased vertical connectivity in sea ice due to the upward percolation of seawater and meltwater flushing during sea ice melt. Based on the change in TA in the water column around the onset of sea ice melt, more than half of the total ikaite precipitated in the ice during sea ice growth was still contained in the ice when the sea ice began to melt. Ikaite crystal dissolution in the water column kept the seawater pCO2 undersaturated with respect to the atmosphere in spite of increased salinity, TA and TCO2 associated with sea ice growth. Results indicate that ikaite export from sea ice and its dissolution in the underlying

  4. Sustainable and safe energy supply with seawater uranium fueled HTGR and its economy

    International Nuclear Information System (INIS)

    Fukaya, Y.; Goto, M.

    2017-01-01

    Highlights: • We discussed uranium resources with an energy security perspective. • We concluded seawater uranium is preferable for sustainability and energy security. • We evaluated electricity generation cost of seawater uranium fueled HTGR. • We concluded electricity generation with seawater uranium is reasonable. - Abstract: Sustainable and safe energy supply with High Temperature Gas-cooled Reactor (HTGR) fueled by uranium from seawater have been investigated and discussed. From the view point of safety feature of self-regulation with thermal reactor of HTGR, the uranium resources should be inexhaustible. The seawater uranium is expected to be alternative resources to conventional resources because it exists so much in seawater as a solute. It is said that 4.5 billion tons of uranium is dissolved in the seawater, which corresponds to a consumption of approximately 72 thousand years. Moreover, a thousand times of the amount of 4.5 trillion tU of uranium, which corresponds to the consumption of 72 million years, also is included in the rock on the surface of the sea floor, and that is also recoverable as seawater uranium because uranium in seawater is in an equilibrium state with that. In other words, the uranium from seawater is almost inexhaustible natural resource. However, the recovery cost with current technology is still expensive compared with that of conventional uranium. Then, we assessed the effect of increase in uranium purchase cost on the entire electricity generation cost. In this study, the economy of electricity generation of cost of a commercial HTGR was evaluated with conventional uranium and seawater uranium. Compared with ordinary LWR using conventional uranium, HTGR can generate electricity cheaply because of small volume of simple direct gas turbine system compared with water and steam systems of LWR, rationalization by modularizing, and high thermal efficiency, even if fueled by seawater uranium. It is concluded that the HTGR

  5. Ultra-trace plutonium determination in small volume seawater by sector field inductively coupled plasma mass spectrometry with application to Fukushima seawater samples.

    Science.gov (United States)

    Bu, Wenting; Zheng, Jian; Guo, Qiuju; Aono, Tatsuo; Tagami, Keiko; Uchida, Shigeo; Tazoe, Hirofumi; Yamada, Masatoshi

    2014-04-11

    Long-term monitoring of Pu isotopes in seawater is required for assessing Pu contamination in the marine environment from the Fukushima Dai-ichi Nuclear Power Plant accident. In this study, we established an accurate and precise analytical method based on anion-exchange chromatography and SF-ICP-MS. This method was able to determine Pu isotopes in seawater samples with small volumes (20-60L). The U decontamination factor was 3×10(7)-1×10(8), which provided sufficient removal of interfering U from the seawater samples. The estimated limits of detection for (239)Pu and (240)Pu were 0.11fgmL(-1) and 0.08fgmL(-1), respectively, which corresponded to 0.01mBqm(-3) for (239)Pu and 0.03mBqm(-3) for (240)Pu when a 20L volume of seawater was measured. We achieved good precision (2.9%) and accuracy (0.8%) for measurement of the (240)Pu/(239)Pu atom ratio in the standard Pu solution with a (239)Pu concentration of 11fgmL(-1) and (240)Pu concentration of 2.7fgmL(-1). Seawater reference materials were used for the method validation and both the (239+240)Pu activities and (240)Pu/(239)Pu atom ratios agreed well with the expected values. Surface and bottom seawater samples collected off Fukushima in the western North Pacific since March 2011 were analyzed. Our results suggested that there was no significant variation of the Pu distribution in seawater in the investigated areas compared to the distribution before the accident. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Seawater-drowning-induced acute lung injury: From molecular mechanisms to potential treatments.

    Science.gov (United States)

    Jin, Faguang; Li, Congcong

    2017-06-01

    Drowning is a crucial public safety problem and is the third leading cause of accidental fatality, claiming ~372,000 lives annually, worldwide. In near-drowning patients, acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) is one of the most common complications. Approximately 1/3 of near-drowning patients fulfill the criteria for ALI or ARDS. In the present article, the current literature of near-drowning, pathophysiologic changes and the molecular mechanisms of seawater-drowning-induced ALI and ARDS was reviewed. Seawater is three times more hyperosmolar than plasma, and following inhalation of seawater the hyperosmotic seawater may cause serious injury in the lung and alveoli. The perturbing effects of seawater may be primarily categorized into insufficiency of pulmonary surfactant, blood-air barrier disruption, formation of pulmonary edema, inflammation, oxidative stress, autophagy, apoptosis and various other hypertonic stimulation. Potential treatments for seawater-induced ALI/ARDS were also presented, in addition to suggestions for further studies. A total of nine therapeutic strategies had been tested and all had focused on modulating the over-activated immunoreactions. In conclusion, seawater drowning is a complex injury process and the exact mechanisms and potential treatments require further exploration.

  7. Different Planctomycetes diversity patterns in latitudinal surface seawater of the open sea and in sediment.

    Science.gov (United States)

    Shu, Qinglong; Jiao, Nianzhi

    2008-04-01

    The 16S rRNA gene approach was applied to investigate the diversity of Planctomycetes in latitudinal surface seawater of the Western Pacific Ocean. The results revealed that the Pirellula-Rhodopirellula-Blastopirellula clade dominated the Planctomycetes community at all surface seawater sites while the minority genera Gemmata and Planctomyces were only found at sites H5 and H2 respectively. Although the clone frequency of the PRB clade seemed stable (between 83.3% and 94.1%) for all surface seawater sites, the retrieved Pirellula-Rhodopirellula-Blastopirellula clade presented unexpected diversity. Interestingly, low latitude seawater appeared to have higher diversity than mid-latitudes. integral-LIBSHUFF software analysis revealed significantly different diversity patterns between in latitudinal surface seawater and in the sediment of South China Sea station M2896. Our data suggested that different hydrological and geographic features contributed to the shift of Planctomycetes diversity in marine environments. This is, to our knowledge, the first systematic assessment of Planctomycetes in latitudinal surface seawater of the open sea and the first comparison of diversity pattern between surface seawater and sediments and has broadened our understanding of Planctomycetes diversity in marine environments.

  8. Determination of trace metals in coastal seawater around Okinawa and its multielement profiling analysis

    International Nuclear Information System (INIS)

    Itoh, Akihide; Ishigaki, Teruyuki; Arakaki, Teruo; Yamada, Ayako; Yamaguchi, Mami; Kabe, Noriko

    2009-01-01

    In the present study, trace metals in coastal surface seawater around Okinawa were determined by inductively coupled plasma mass spectrometry (ICP-MS) with chelating disk preconcentration. As a result, the concentrations of V, Mn, Co, Ni, Cu, Zn, Mo, Cd, Pb, and U were obtained in the range from 10 μgL -1 to 0.001 μgL -1 for 6 samples. In addition, multielement profiling analyses were carried out using analytical values obtained in order to elucidate the features of trace metals in each coastal sea area. For coastal surface seawater near an urban area, the analytical values for Zn, Cu, Mn, and Pb were higher by more than 10-fold the literature values for open-surface seawater, and those of Cd were also relatively high. Such a trend concerning the multi-element profile was almost similar to the literature values for coastal seawater of the main island of Japan. On the other hand, the analytical values of most elements for coastal surface seawater near a suburb area were in the range from 0.5 to 5 fold, compared to the literature values for open surface seawater. From multielement profiling analyses for nutrient type elements in marine chemistry, it was suggested that the concentrations of Zn and Cd in a coral sea area normalized to literature values for open surface-seawater were higher than those of Ni and Cu. (author)

  9. Seawater-drowning-induced acute lung injury: From molecular mechanisms to potential treatments

    Science.gov (United States)

    Jin, Faguang; Li, Congcong

    2017-01-01

    Drowning is a crucial public safety problem and is the third leading cause of accidental fatality, claiming ~372,000 lives annually, worldwide. In near-drowning patients, acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) is one of the most common complications. Approximately 1/3 of near-drowning patients fulfill the criteria for ALI or ARDS. In the present article, the current literature of near-drowning, pathophysiologic changes and the molecular mechanisms of seawater-drowning-induced ALI and ARDS was reviewed. Seawater is three times more hyperosmolar than plasma, and following inhalation of seawater the hyperosmotic seawater may cause serious injury in the lung and alveoli. The perturbing effects of seawater may be primarily categorized into insufficiency of pulmonary surfactant, blood-air barrier disruption, formation of pulmonary edema, inflammation, oxidative stress, autophagy, apoptosis and various other hypertonic stimulation. Potential treatments for seawater-induced ALI/ARDS were also presented, in addition to suggestions for further studies. A total of nine therapeutic strategies had been tested and all had focused on modulating the over-activated immunoreactions. In conclusion, seawater drowning is a complex injury process and the exact mechanisms and potential treatments require further exploration. PMID:28587319

  10. Plutonium determination in seawater by inductively coupled plasma mass spectrometry: A review.

    Science.gov (United States)

    Cao, Liguo; Bu, Wenting; Zheng, Jian; Pan, Shaoming; Wang, Zhongtang; Uchida, Shigeo

    2016-05-01

    Knowing the concentration and isotopic ratio of Pu in seawater is of critical importance for assessing Pu contamination and investigating oceanic processes. In recent decades, the concentration of (239+240)Pu in seawater, particularly for surface seawater, has presented an exponential decreasing trend with time; thus determination of Pu in seawater has become a challenge nowadays. Here, we have summarized and critically discussed a variety of reported analytical methods for Pu determination in seawater sample based on inductively coupled plasma mass spectrometry (ICP-MS) analytical technique for rapid ultra-trace detection of Pu. Generally, pretreatments for seawater sample include co-precipitation, valence adjustment and chemical separation and purification procedures, all of which are comprehensively reviewed. Overall, the selected anion-exchange, extraction resins and operation condition are important for decontamination of interference from matrix elements and achieving satisfactory chemical yields. In addition, other mass spectrometric and radiometric detections are briefly addressed and compared with the focus on assessing ICP-MS. Finally, we discuss some issues and prospects in determination and application of Pu isotopes in seawater samples for future research. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. A field study of physico-chemical states of artificial radionuclides in seawater

    International Nuclear Information System (INIS)

    Nagaya, Yutaka; Nakamura, Kiyoshi

    1974-01-01

    The physico-chemical states of artificial radionuclides, 90 Sr, 137 Cs and 144 Ce in seawater were investigated by radiochemical analysis of filtered and unfiltered seawater. The difference of radionuclide concentrations between unfiltered and filtered seawaters was defined as the ''particulate form'' radioisotope and its ''particle ratio'' was discussed. Practically no particulate 90 Sr, greater than 0.22 μ in size, was observed in both coastal and open seawaters, but some of 137 Cs seemed to be insoluble in some circumstances, especially in coastal waters. A considerable amount of 144 Ce was found to be particulate. An estimation of the radionuclides in particulate form was made for Kashima-nada seawaters collected in 1970 to 1972, and it was shown that the possible occurrence of particulate radionuclides, greater than 0.22 μ in size, were 1% or less for 90 Sr and 6% for 137 Cs. In the coastal water, 80% of 144 Ce were seemed to be in particulate form, but in the open seawater only a few %. The influences of suspended materials to 137 Cs and 144 Ce concentration levels in seawater were not negligible and further investigations are desirable. (auth.)

  12. A solvent extraction technique for the isotopic measurement of dissolved copper in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Claire M., E-mail: claire.thompson@anu.edu.au; Ellwood, Michael J., E-mail: michael.ellwood@anu.edu.au; Wille, Martin, E-mail: martin.wille@uni-tuebingen.de

    2013-05-02

    Graphical abstract: -- Highlights: •A new sample preparation method for seawater copper isotopic analysis (δ{sup 65}Cu). •Solvent-extraction was used to pre-concentrate metals from seawater samples. •Anion-exchange was used to purify copper from the metal-rich extract. •δ{sup 65}Cu was measured in the north Tasman Sea. •Seawater δ{sup 65}Cu may be linked to marine biological activity. -- Abstract: Stable copper (Cu) isotope geochemistry provides a new perspective for investigating and understanding Cu speciation and biogeochemical Cu cycling in seawater. In this work, sample preparation for isotopic analysis employed solvent-extraction with amino pyrollidine dithiocarbamate/diethyl dithiocarbamate (APDC/DDC), coupled with a nitric acid back-extraction, to concentrate Cu from seawater. This was followed by Cu-purification using anion-exchange. This straightforward technique is high yielding and fractionation free for Cu and allows precise measurement of the seawater Cu isotopic composition using multi-collector inductively coupled plasma mass-spectrometry. A deep-sea profile measured in the oligotrophic north Tasman Sea shows fractionation in the Cu isotopic signature in the photic zone but is relatively homogenised at depth. A minima in the Cu isotopic profile correlates with the chlorophyll a maximum at the site. These results indicate that a range of processes are likely to fractionate stable Cu isotopes in seawater.

  13. Cardiorespiratory upregulation during seawater acclimation in rainbow trout: effects on gastrointestinal perfusion and postprandial responses.

    Science.gov (United States)

    Brijs, Jeroen; Gräns, Albin; Ekström, Andreas; Olsson, Catharina; Axelsson, Michael; Sandblom, Erik

    2016-05-01

    Increased gastrointestinal blood flow is essential for euryhaline fishes to maintain osmotic homeostasis during the initial phase of a transition from freshwater to seawater. However, the cardiorespiratory responses and hemodynamic changes required for a successful long-term transition to seawater remain largely unknown. In the present study, we simultaneously measured oxygen consumption rate (ṀO2), cardiac output (CO), heart rate (HR), and gastrointestinal blood flow (GBF) in rainbow trout (Oncorhynchus mykiss) acclimated to either freshwater or seawater for at least 6 wk. Seawater-acclimated trout displayed significantly elevated ṀO2 (day: 18%, night: 19%), CO (day: 22%, night: 48%), and GBF (day: 96%, night: 147%), demonstrating that an overall cardiorespiratory upregulation occurs during seawater acclimation. The elevated GBF was achieved via a combination of increased CO, mediated through elevated stroke volume (SV), and a redistribution of blood flow to the gastrointestinal tract. Interestingly, virtually all of the increase in CO of seawater-acclimated trout was directed to the gastrointestinal tract. Although unfed seawater-acclimated trout displayed substantially elevated cardiorespiratory activity, the ingestion of a meal resulted in a similar specific dynamic action (SDA) and postprandial GBF response as in freshwater-acclimated fish. This indicates that the capacity for the transportation of absorbed nutrients, gastrointestinal tissue oxygen delivery, and acid-base regulation is maintained during digestion in seawater. The novel findings presented in this study clearly demonstrate that euryhaline fish upregulate cardiovascular function when in seawater, while retaining sufficient capacity for the metabolic and cardiovascular changes associated with the postprandial response. Copyright © 2016 the American Physiological Society.

  14. Investigation on the effect of seawater to hydraulic property and wetting process of bentonite

    International Nuclear Information System (INIS)

    Hasegawa, Takuma

    2004-01-01

    On high-level waste disposal, bentonite is one of the most promising material for buffer and backfill material. The hydraulic properties and wetting process of bentonite are important not only for barrier performance assessment but also for prediction of waste disposal environment, such as resaturation time and thermal distribution. In Japan, we should consider the effect of seawater for bentonite, because radioactive waste will be disposed of in coastal area and in marine sediment where seawater remained. However, it is not enough to understand the effect of seawater. Therefore, experimental study was conducted to investigate the effect of seawater on the hydraulic conductivity and wetting process of bentonite. The effect of seawater on hydraulic conductivity is significant for Na-bentonite, the hydraulic conductivity of Na-bentonite in seawater is one order to magnitude higher than that in distilled water. On the other hand, the hydraulic conductivity of Ca-bentonite is not influenced by seawater. The hydraulic conductivity of bentonite decreases as effective montmorillonite density increases. The effective montmorillonite density is ratio between the weight of montmorillonite and volume of porosity and montmorillonite. The hydraulic conductivity of bentonite is close related to swelling property since the hydraulic conductivity decrease as the swelling pressure increase. Wetting process of compacted bentonite could be evaluated by diffusion phenomena since infiltration rate and change of saturation rate and represented by diffusion equation. The effect of seawater on water diffusivity is significant for Na-type bentonite with low effective montmorillonite density. Except for that condition, the water diffusivity of bentonite is almost constant and is not influenced by effective montmorillonite density and seawater. (author)

  15. Morpholino Gene Knockdown in Adult Fundulus heteroclitus: Role of SGK1 in Seawater Acclimation

    Science.gov (United States)

    Notch, Emily G.; Shaw, Joseph R.; Coutermarsh, Bonita A.; Dzioba, Marisa; Stanton, Bruce A.

    2011-01-01

    The Atlantic killifish (Fundulus heteroclitus) is an environmental sentinel organism used extensively for studies on environmental toxicants and salt (NaCl) homeostasis. Previous research in our laboratory has shown that rapid acclimation of killifish to seawater is mediated by trafficking of CFTR chloride channels from intracellular vesicles to the plasma membrane in the opercular membrane within the first hour in seawater, which enhances chloride secretion into seawater, thereby contributing to salt homeostasis. Acute transition to seawater is also marked by an increase in both mRNA and protein levels of serum glucocorticoid kinase 1 (SGK1) within 15 minutes of transfer. Although the rise in SGK1 in gill and its functional analog, the opercular membrane, after seawater transfer precedes the increase in membrane CFTR, a direct role of SGK1 in elevating membrane CFTR has not been established in vivo. To test the hypothesis that SGK1 mediates the increase in plasma membrane CFTR we designed two functionally different vivo-morpholinos to knock down SGK1 in gill, and developed and validated a vivo-morpholino knock down technique for adult killifish. Injection (intraperitoneal, IP) of the splice blocking SGK1 vivo-morpholino reduced SGK1 mRNA in the gill after transition from fresh to seawater by 66%. The IP injection of the translational blocking and splice blocking vivo-morpholinos reduced gill SGK1 protein abundance in fish transferred from fresh to seawater by 64% and 53%, respectively. Moreover, knock down of SGK1 completely eliminated the seawater induced rise in plasma membrane CFTR, demonstrating that the increase in SGK1 protein is required for the trafficking of CFTR from intracellular vesicles in mitochondrion rich cells to the plasma membrane in the gill during acclimation to seawater. This is the first report of the use of vivo-morpholinos in adult killifish and demonstrates that vivo-morpholinos are a valuable genetic tool for this environmentally

  16. Symbiotic Role of the Viable but Nonculturable State of Vibrio fischeri in Hawaiian Coastal Seawater.

    Science.gov (United States)

    Lee, K; Ruby, E G

    1995-01-01

    To achieve functional bioluminescence, the developing light organ of newly hatched juveniles of the Hawaiian squid Euprymna scolopes must become colonized by luminous, symbiosis-competent Vibrio fischeri present in the ambient seawater. This benign infection occurs rapidly in animals placed in seawater from the host's natural habitat. Therefore, it was surprising that colony hybridization studies with a V. fischeri-specific luxA gene probe indicated the presence of only about 2 CFU of V. fischeri per ml of this infective seawater. To examine this paradox, we estimated the total concentration of V. fischeri cells present in seawater from the host's habitat in two additional ways. In the first approach, the total bacterial assemblage in samples of seawater was collected on polycarbonate membrane filters and used as a source of both a crude cell lysate and purified DNA. These preparations were then assayed by quantitative DNA-DNA hybridization with the luxA gene probe. The results suggested the presence of between 200 and 400 cells of V. fischeri per ml of natural seawater, a concentration more than 100 times that revealed by colony hybridization. In the second approach, we amplified V. fischeri-specific luxA sequences from microliter volumes of natural seawater by PCR. Most-probable-number analyses of the frequency of positive PCR results from cell lysates in these small volumes gave an estimate of the concentration of V. fischeri luxA gene targets of between 130 and 1,680 copies per ml. From these measurements, we conclude that in their natural seawater environment, the majority of V. fischeri cells become nonculturable while remaining viable and symbiotically infective. Experimental studies indicated that V. fischeri cells suspended in natural Hawaiian seawater enter such a state within a few days.

  17. Intercomparison study of sampling methods for the determination of polychlorinated biphenyl (PCB) in seawater

    International Nuclear Information System (INIS)

    Schulz-Bull, D.E.

    1999-01-01

    The determination of organic pollutants in seawater is a serious problem, as their concentrations in the water column are typical in the fg - ng/L range. Available methods therefore includes extensive sampling and laboratory work. The development of simple sampling techniques for organochlorines (e.g. passive sampling with semipermeable membrane device (SPMD), mussel watch) is required. Three methods for the measurement of trace organochlorines in seawater were investigated: (1) the filtration (GF/F) and extraction (XAD-2 resin) of seawater with an in-situ pumping system, (2) biological-accumulation by mussels (mytilus edulis) and (3) passive sampling with SPMD

  18. A study on antifouling technique through seawater electrolyzing reaction on ship hull surface 【Article】

    OpenAIRE

    Huang, Yi; Saito, Kimio; Usami, Masahiro

    2003-01-01

    The antifouling technique through seawater electrolysis for ship hulls may be realized by an antifoul-ing system consisting of a power unit and the electro-conductive film. In the electric field formed bysuch an antifouling system, besides that both the electro-conductive film layer sub-region and the sea-water sub-region are included, polarization occurs on the interface between electro-conductive film layerand seawater. Therefore, based on the Interface Electro-Double Layer theory, a numeri...

  19. Anion-exchange enrichment and spectrophotometric determination of uranium in sea-water

    International Nuclear Information System (INIS)

    Kuroda, Rokuro; Oguma, Koichi; Mukai, Noriko; Iwamoto, Masatoshi

    1987-01-01

    A method is proposed for the determination of uranium in sea-water. The uranium is strongly sorbed on a strongly basic anion-exchange resin (Cl - form) from acidified sea-water containing sodium azide (0.3M) and is easily eluted with 1M hydrochloric acid. Uranium in the effluent can be determined spectrophotometrically with Arsenazo III. The combined method allows easy and selective determination of uranium in sea-water without using a sophisticated adsorbent. The overall recovery and precision are satisfactory at the 3 μg/1. level. (author)

  20. Aragonite coating solutions (ACS) based on artificial seawater

    Science.gov (United States)

    Tas, A. Cuneyt

    2015-03-01

    Aragonite (CaCO3, calcium carbonate) is an abundant biomaterial of marine life. It is the dominant inorganic phase of coral reefs, mollusc bivalve shells and the stalactites or stalagmites of geological sediments. Inorganic and initially precipitate-free aragonite coating solutions (ACS) of pH 7.4 were developed in this study to deposit monolayers of aragonite spherules or ooids on biomaterial (e.g., UHMWPE, ultrahigh molecular weight polyethylene) surfaces soaked in ACS at 30 °C. The ACS solutions of this study have been developed for the surface engineering of synthetic biomaterials. The abiotic ACS solutions, enriched with calcium and bicarbonate ions at different concentrations, essentially mimicked the artificial seawater composition and started to deposit aragonite after a long (4 h) incubation period at the tropical sea surface temperature of 30 °C. While numerous techniques for the solution deposition of calcium hydroxyapatite (Ca10(PO4)6(OH)2), of low thermodynamic solubility, on synthetic biomaterials have been demonstrated, procedures related to the solution-based surface deposition of high solubility aragonite remained uncommon. Monolayers of aragonite ooids deposited at 30 °C on UHMWPE substrates soaked in organic-free ACS solutions were found to possess nano-structures similar to the mortar-and-brick-type botryoids observed in biogenic marine shells. Samples were characterized using SEM, XRD, FTIR, ICP-AES and contact angle goniometry.

  1. On the classification of active and passive seawater intrusion

    Science.gov (United States)

    Werner, A. D.

    2017-12-01

    Active and passive seawater intrusion (SWI) arise when the freshwater head gradient slopes downwards towards land and the sea, respectively. However, a third category exists (i.e., passive-active SWI), whereby active SWI occurs inland of a mound in piezometric surface, whereas passive SWI occurs on the seaward side of the mound. In this study, numerical modelling is used to characterize the three forms of SWI, including an overview of the transient features of active SWI. While only simple cross-sectional representations of coastal aquifer settings are considered, the analysis provides guidance on some of the key attributes of each SWI class, as an extension to previous SWI research that offers limited differentiation between the various SWI types. Threshold parameter combinations for the onset of each form of SWI are provided, as derived from sharp-interface, steady-state analytical solutions. Dispersive aspects of SWI are then explored using numerical simulation. Important differences between the various forms of SWI include the salinization of the watertable that occurs under active SWI and in the absence of recharge, and the formation of persistent freshwater lenses in aquifers experiencing active SWI but also subject to surface recharge. Attempts to characterize transient active SWI processes, in terms of buoyancy, advective and dispersive processes, using dimensionless ratios that are drawn from previous studies of steady-state SWI, highlight the complex, nonlinear relationships that govern active SWI, even for idealized circumstances.

  2. Direct determination of molybdenum in seawater by adsorption voltametry

    International Nuclear Information System (INIS)

    Berg, M.G. van den.

    1985-01-01

    Complex ions of molybdenum(VI) with 8-hydroxyquinoline (oxine) are shown to adsorb onto the hanging mercury drop electrode. This property forms the basis of a sensitive electrochemical technique by which dissolved molybdenum in seawater can be determined directly. The reduction current of adsorbed complex ions is measured by differential pulse adsorption voltametry, preceded by a period of 1 or 2 min of unstirred collection at an adsorption potential of -0.2 V. In the presence of 2 x 10 -3 M oxine and at pH 2.5 the potential of the main reduction peak is located at -0.59 V. The peak current-molybdenum concentration relationship is linear up to 3 x 10 -7 M; the detection limit is 4 nM. Greater sensitivity is obtained after stirred collection at pH 3.0 and with 10 -4 M oxine, but the calibration curve is nonlinear. In these conditions the limit of detection lies at 10 -10 M after 10 min stirred collection. 19 references, 8 figures

  3. Butiltins Compound in Seawater and Sediment of Banten Bay

    Directory of Open Access Journals (Sweden)

    Hamidah Razak

    2004-08-01

    Full Text Available bservation on butiltin (BTs compound content in seawater and sediments from Banten Bay were conducted in August 2003 and October 2003. Butiltin content including TBT, DBT and MBT on August 2003 respectively range between <2ng Sn/l, <2 to 9 ng Sn/l and < 5 to 17 ng Sn/l and on October 2003 was found respectively nd to <2 ng Sn/l, <0.5 to 12 ng Sn/g, 0.5 to 2.7 ng Sn/g and <0.5 to 2.2 ng Sn/g, and on October 2003 was found varied from <0.5 to 4.2ng Sn/g, <0.5 to 1.1ng Sn/g and <0.5 to 1 ng Sn/g. Content of TBT was found on August 2003 higher than October 03 and also the content of TBT compound in sediments was high compared to waters. It indicated that there was accumulation of TBT in sediment. The minimal risk of TBT in seaport and for marine life according to Minister of environment in Keputusan Menteri Negara Kependudukan dan Lingkungan Hidup No.51 tahun 2004 is 10 ng/l. The results showed that Banten Bay is still appropiate for seaport and marine life.

  4. Seawater desalination using an advanced small integral reactor - SMART

    International Nuclear Information System (INIS)

    Hwang, Young Dong; Chang, Moon Hee; Lee, Man Ki

    1999-01-01

    A concept of a dual-purpose integrated nuclear desalination plant coupled with the advanced small integral reactor SMART was established. The design concept of the plant aims to produce 40,000m 5 /day of water with the MED process and to generate about 90 MWe of electricity. In order to examine the technical, economic, and safety considerations in coupling SMART with desalination, a preliminary analysis on water production costs and a safety review of potential disturbances of the integrated nuclear desalination plant have been performed. The results of economic evaluation show that the use of SMART for seawater desalination is either comparative to or more economical, with respect to the water production cost, than the use of fossil fuels in comparison with the data published by the IAEA. It was also found that any possible transient event of the desalination plant does not impact on the reactor safety. The key safety parameters of the transient events induced by the potential disturbances of the desalination plant are bounded by the limits of safety analysis of SMART

  5. Seawater desalination in micro grids. An integrated planning approach

    Energy Technology Data Exchange (ETDEWEB)

    Bognar, Kristina; Behrendt, Frank [Technische Univ. Berlin (Germany). Dept. of Energy Engineering; Blechinger, Philipp [Technische Univ. Berlin (Germany). Dept. of Energy Engineering; Reiner Lemoine Institut gGmbH, Berlin (Germany)

    2012-12-15

    Islands often depend on the import of fossil fuels for power generation. Due to the combined effect of high oil prices and transportation costs, energy supply systems based on renewable energies are already able to compete successfully with fossil fuel systems for a number of these islands. Depending on local and regional conditions, not only energy supply is a challenge, but also the finding of a reliable supply of water. A promising alternative to freshwater shipments is seawater desalination. Desalination processes can act as a flexible load whenever excess electricity generated by renewable sources is present. Numerical simulations of combined energy and water supply systems for the Caribbean island, Petite Martinique, Grenada, are accomplished. Considering renewable energy sources like wind and solar radiation, energy storage technologies, and desalination processes, various scenarios are introduced and simulated, and the results are compared. An extension of the current energy supply system with renewable energy technologies reduces power generation costs by approximately 40%. The excess energy generated by renewables can supply a significant share of a desalination plant's energy demand. The levelized costs of electricity and water show that the integration of desalination as a deferrable load is beneficial to the considered micro grid. The implementation of renewable energy generation and desalination as deferrable load is recommendable in Petite Martinique. Possible refinancing strategies depending on the combination of different electricity and water tariffs can be derived and applied to similar business cases in remote regions. (orig.)

  6. Corrosion of titanium alloys in high temperature near anaerobic seawater

    International Nuclear Information System (INIS)

    Pang, Jianjun; Blackwood, Daniel J.

    2016-01-01

    Highlights: • In absence of CO 2 Ti grades 2 and 5 suffer crevice corrosion at temperatures 80 °C and 200 °C. • For Ti grade 5 crevice corrosion can occur as low as 80 °C in the presence of CO 2 . • Ti grade 7 is immune to crevice corrosion in test conditions. • All grades resistant to SCC and pitting in presence of CO 2 . • Rare earth yttrium additions below 0.2 wt%. for improved mechanical properties are detrimental to corrosions performance. • Analysis of threat of hydrogen induced cracking suggest this is not a threat at a deepsea well head. - Abstract: Grades 2, 5 and Grade 7 were investigated in near anaerobic (<1 ppm oxygen) seawater up to 200 °C with and without CO 2 . All three grades were found to resist stress corrosion cracking and pitting corrosion. Grades 2 and 5 suffer crevice corrosion at temperatures 80 °C and 200 °C respectively. In the presence of CO 2 Grade 5 becomes more vulnerable to crevice corrosion, with attack starting at 80 °C with preferential dissolution of the beta phase. An analysis of the threat of hydrogen induced cracking leads to the conclusion that this was not a likely threat to any of the Ti alloys investigated.

  7. Determination of Uranium and Thorium in Drinking and Seawater

    International Nuclear Information System (INIS)

    Rozmaric Macefat, M.; Gojmerac Ivsic, A.; Grahek, Z.; Barisic, D.

    2008-01-01

    Uranium and thorium are the first members of natural radioactive chain which makes their determination in natural materials interesting from geochemical and radioecological aspect. They are quantitatively determined as elements by spectrophotometric method and/or their radioisotopes by alpha spectrometry and ICP-MS. It is necessary to develop inexpensive, rapid and sensitive methods for the routine researches because of continuous monitoring of the radioactivity level. Development of a new method for the isolation of uranium and thorium from liquid samples and subsequent spectrophotometric determination is described in this paper. It is possible to isolate uranium and thorium from drinking and seawater using extraction chromatography or ion exchange chromatography. Uranium and thorium can be strongly bound on the TRU extraction chromatographic resin from 3 mol dm -3 HNO 3 (chemical recovery is 100 percent) and separated from other interfering elements (sodium, potassium, calcium, strontium etc). Their mutual separation is possible by using anion exchanger Amberlite CG-400 (NO 3 - form). From alcoholic solutions of nitric acid thorium can be strongly bound on the anion exchanger while uranium is much more weakly bound which enables its separation from thorium. After the separation, uranium and thorium are determined by spectrophotometric method with arsenazo III at 652 nm and 662 nm respectively. Developed method enables selection of the optimal mode of isolation for the given purposes.(author)

  8. Microbial degradation of pharmaceuticals in estuarine and coastal seawater

    Energy Technology Data Exchange (ETDEWEB)

    Benotti, Mark J. [Marine Sciences Research Center, Stony Brook University, Stony Brook, NY 11794-5000 (United States); Brownawell, Bruce J. [Marine Sciences Research Center, Stony Brook University, Stony Brook, NY 11794-5000 (United States)], E-mail: bruce.brownawell@sunysb.edu

    2009-03-15

    Microbial degradation rates were measured for 19 pharmaceuticals in estuarine and coastal surface water samples. Antipyrine, carbamazepine, cotinine, sulfamethoxazole, and trimethoprim were the most refractory (half-lives, t{sub 1/2} = 35 to >100 days), making them excellent candidates for wastewater tracers. Nicotine, acetaminophen, and fluoxetine were labile across all treatments (t{sub 1/2} = 0.68-11 days). Caffeine, diltiazem, and nifedipine were also and relatively labile in all but one of the treatments (t{sub 1/2} = 3.5-13 days). Microbial degradation of caffeine was further confirmed by production {sup 14}CO{sub 2}. The fastest decay of non-refractory compounds was always observed in more sewage-affected Jamaica Bay waters. Degradation rates for the majority of these pharmaceuticals are much slower than reported rates for small biomolecules, such as glucose and amino acids. Batch sorption experiments indicate that removal of these soluble pharmaceuticals from the water column to sediments is a relatively insignificant removal process in these receiving waters. - Microbial degradation rates were measured for 19 structurally variable pharmaceuticals in wastewater-impacted estuarine and coastal seawater.

  9. Systems studies on the extraction of uranium from seawater

    International Nuclear Information System (INIS)

    Driscoll, M.J.; Best, F.R.

    1981-11-01

    This report summarizes the work done at MIT during FY 1981 on the overall system design of a uranium-from-seawater facility. It consists of a sequence of seven major chapters, each of which was originally prepared as a stand-alone internal progress report. These chapters trace the historical progression of the MIT effort, from an early concern with scoping calculations to define the practical boundaries of a design envelope, as constrained by elementary economic and energy balance considerations, through a parallel evaluation of actively-pumped and passive current-driven concepts, and thence to quantification of the features of a second generation system based on a shipboard-mounted, actively-pumped concept designed around the use of thin beds of powdered ion exchange resin supported by cloth fiber cylinders (similar to the baghouse flyash filters used on power station offgas). An assessment of the apparently inherent limitations of even thin settled-bed sorber media then led to selection of an expanded bed (in the form of an ion exchange wool), which would permit an order of magnitude increase in flow loading, as a desirable advance. Thus the final two chapters evaluate ways in which this approach could be implemented, and the resulting performance levels which could be attained. Overall, U 3 O 8 production costs under 200 $/lb appear to be within reach if a high capacity (several thousand ppM U) ion exchange wool can be developed

  10. SEAWAT-based simulation of axisymmetric heat transport.

    Science.gov (United States)

    Vandenbohede, Alexander; Louwyck, Andy; Vlamynck, Nele

    2014-01-01

    Simulation of heat transport has its applications in geothermal exploitation of aquifers and the analysis of temperature dependent chemical reactions. Under homogeneous conditions and in the absence of a regional hydraulic gradient, groundwater flow and heat transport from or to a well exhibit radial symmetry, and governing equations are reduced by one dimension (1D) which increases computational efficiency importantly. Solute transport codes can simulate heat transport and input parameters may be modified such that the Cartesian geometry can handle radial flow. In this article, SEAWAT is evaluated as simulator for heat transport under radial flow conditions. The 1971, 1D analytical solution of Gelhar and Collins is used to compare axisymmetric transport with retardation (i.e., as a result of thermal equilibrium between fluid and solid) and a large diffusion (conduction). It is shown that an axisymmetric simulation compares well with a fully three dimensional (3D) simulation of an aquifer thermal energy storage systems. The influence of grid discretization, solver parameters, and advection solution is illustrated. Because of the high diffusion to simulate conduction, convergence criterion for heat transport must be set much smaller (10(-10) ) than for solute transport (10(-6) ). Grid discretization should be considered carefully, in particular the subdivision of the screen interval. On the other hand, different methods to calculate the pumping or injection rate distribution over different nodes of a multilayer well lead to small differences only. © 2013, National Ground Water Association.

  11. The interaction of physical properties of seawater via statistical approach

    Science.gov (United States)

    Hamzah, Firdaus Mohamad; Jaafar, Othman; Sabri, Samsul Rijal Mohd; Ismail, Mohd Tahir; Jaafar, Khamisah; Arbin, Norazman

    2015-09-01

    It is of importance to determine the relationships between physical parameters in marine ecology. Model and expert opinion are needed for exploration of the form of relationship between two parameters due to the complexity of the ecosystems. These need justification with observed data over a particular periods. Novel statistical techniques such as nonparametric regression is presented to investigate the ecological relationships. These are achieved by demonstrating the features of pH, salinity and conductivity at in Straits of Johor. The monthly data measurements from 2004 until 2013 at a chosen sampling location are examined. Testing for no-effect followed by linearity testing for the relationships between salinity and pH; conductivity and pH, and conductivity and salinity are carried out, with the ecological objectives of investigating the evidence of changes in each of the above physical parameters. The findings reveal the appropriateness of smooth function to explain the variation of pH in response to the changes in salinity whilst the changes in conductivity with regards to different concentrations of salinity could be modelled parametrically. The analysis highlights the importance of both parametric and nonparametric models for assessing ecological response to environmental change in seawater.

  12. Experimental analysis of humidification process by air passing through seawater

    International Nuclear Information System (INIS)

    El-Agouz, S.A.; Abugderah, M.

    2008-01-01

    An experimental investigation of humidification process by air passing through seawater is presented. The main objective of this work was to determine the humid air behaviour through single-stage of heating-humidifying processes. This experimental work studied the influence of the operating conditions such as the water temperature, the headwater difference, the air velocity and the inlet air temperature to evaporator chamber on the vapour content difference and humidification efficiency. Two cases of different inlet conditions of ambient and heated air cases are studied. The experimental results show that, the vapour content difference and the humidification efficiency of the system is strongly affected by the saline water temperature in the evaporator chamber, headwater difference and the air velocity. The inlet air temperature to evaporator chamber variation was found to have a small affect on the vapour content difference. The obtained maximum vapour content difference of the air was about 222 gr w /kg a at 75 deg. C for water and air. The obtained vapour content is high compared to that obtained in literature for single-stage and very similar for multi-stage

  13. Corrosion and protection of aluminum alloys in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Nisancioglu Kemal [Department of Materials Technology, Norwegian University of Science and Technology, N-7491 Trondheim (Norway)

    2004-07-01

    The paper deals with pitting and uniform corrosion and effectiveness of cathodic protection in reducing these corrosion forms. In stagnant waters or presence of low flow rates, pitting may occur. However, pitting corrosion, driven by the Fe-rich cathodic intermetallic compounds, is often of superficial nature. The pits tend to passivate as a result of etching or passivation of the intermetallics with time. Cathodic protection is an effective way of preventing pitting. It also requires low current densities since the cathodic area, defined by the Fe-rich intermetallics, is small in contrast to steel, which is uniformly accessible to the cathodic reaction. Although thermodynamic calculations suggest possible instability of the oxide in slightly alkaline solutions, such as seawater, protective nature of the oxide in practice is attributed to the presence of alloying elements such as Mg and Mn. Thus, the passivity of both the aluminum matrix alloy (the anode) and the intermetallics (cathodes) have to be considered in evaluating the corrosion and protection of aluminum alloys. With increasing flow rate, the possibility of pitting corrosion reduces with increase in the rate of uniform corrosion, which is controlled by the flow dependent chemical dissolution of the oxide. Cathodic protection does not stop this phenomenon, and coatings have to be used. (authors)

  14. Seawater strontium isotopes at the Cretaceous-Tertiary boundary

    Science.gov (United States)

    Macdougall, J. D.; Martin, E.

    1988-01-01

    Anomalously high values of Seawater Sr-87/Sr-86 near the Cretaceous-Tertiary (K-T) boundary have been reported. However, few of the data from the literature are from a single continuous section, and perhaps the most complete study of the boundary region, from a shallow marine limestone sequence in Alabama, showed elevated Sr-87/Sr-86 but no pronounced spike. Thus, in order to investigate the cause of the change in strontium isotopic composition, it is important to determine the exact nature and magnitude of the increase by studying in detail continuous sections through the boundary. If there is indeed a Sr isotope spike at the K-T boundary, it requires the addition of a large amount of radiogenic Sr to the oceans over a short time period, a phenomenon that may be linked to other large-scale environmental disturbances which occurred at that time. In order to address this question, a high-resolution strontium isotope study of foraminifera from three Deep Sea Drilling Project (DSDP) cores which recovered the K-T boundary section: Site 356 in the South Atlantic, Site 384 in the North Atlantic and Site 577 from the Shatsky Rise in the Pacific was initiated. The isotope measurements are being made on either single or small numbers of forams carefully picked and identified and in most cases examined by SEM before analysis. Because this work is not yet complete, conclusions drawn here must be viewed as tentative. They are briefly discussed.

  15. Microbial degradation of pharmaceuticals in estuarine and coastal seawater

    International Nuclear Information System (INIS)

    Benotti, Mark J.; Brownawell, Bruce J.

    2009-01-01

    Microbial degradation rates were measured for 19 pharmaceuticals in estuarine and coastal surface water samples. Antipyrine, carbamazepine, cotinine, sulfamethoxazole, and trimethoprim were the most refractory (half-lives, t 1/2 = 35 to >100 days), making them excellent candidates for wastewater tracers. Nicotine, acetaminophen, and fluoxetine were labile across all treatments (t 1/2 = 0.68-11 days). Caffeine, diltiazem, and nifedipine were also and relatively labile in all but one of the treatments (t 1/2 = 3.5-13 days). Microbial degradation of caffeine was further confirmed by production 14 CO 2 . The fastest decay of non-refractory compounds was always observed in more sewage-affected Jamaica Bay waters. Degradation rates for the majority of these pharmaceuticals are much slower than reported rates for small biomolecules, such as glucose and amino acids. Batch sorption experiments indicate that removal of these soluble pharmaceuticals from the water column to sediments is a relatively insignificant removal process in these receiving waters. - Microbial degradation rates were measured for 19 structurally variable pharmaceuticals in wastewater-impacted estuarine and coastal seawater

  16. 'Rare biosphere' bacteria as key phenanthrene degraders in coastal seawaters.

    Science.gov (United States)

    Sauret, Caroline; Séverin, Tatiana; Vétion, Gilles; Guigue, Catherine; Goutx, Madeleine; Pujo-Pay, Mireille; Conan, Pascal; Fagervold, Sonja K; Ghiglione, Jean-François

    2014-11-01

    By coupling DNA-SIP and pyrosequencing approaches, we identified Cycloclasticus sp. as a keystone degrader of polycyclic aromatic hydrocarbons (PAH) despite being a member of the 'rare biosphere' in NW Mediterranean seawaters. We discovered novel PAH-degrading bacteria (Oceanibaculum sp., Sneathiella sp.) and we identified other groups already known to possess this function (Alteromonas sp., Paracoccus sp.). Together with Cycloclasticus sp., these groups contributed to potential in situ phenanthrene degradation at a rate >0.5 mg l(-1) day(-1), sufficient to account for a considerable part of PAH degradation. Further, we characterized the PAH-tolerant bacterial communities, which were much more diverse in the polluted site by comparison to unpolluted marine references. PAH-tolerant bacteria were also members of the rare biosphere, such as Glaciecola sp. Collectively, these data show the complex interactions between PAH-degraders and PAH-tolerant bacteria and provide new insights for the understanding of the functional ecology of marine bacteria in polluted waters. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Nuclear energy for seawater desalination - options in future

    International Nuclear Information System (INIS)

    Yadav, M.K.; Murugan, V.; Balasubramaniyan, C.; Nagaraj, R.; Dangore, Y.

    2010-01-01

    Full text: With ever increasing water scarcity, many alternatives are being tried to supplement the existing water resources. There are regions where water is scarce and population is growing and is at the mercy of inadequate supplies. Seawater constitutes a practically unlimited source of saline water. When desalted, it can augment the existing potable water resources for the people in nearby area and also meet the increasing demand. BARC has been engaged in the field of desalination and developed expertise in both thermal and membrane technologies. It has setup 6300 M 3 /D Nuclear Desalination Demonstration Project (NDDP) at Kalpakkam, where both membrane and thermal technologies have been used for sea water desalination. Desalination process needs energy and nuclear energy is strong option in view of limited fossil fuels and environmental concerns. Multi Stage Flash (MSF) plant based on thermal technology has been coupled to MAPS Reactors and Sea Water Reverse Osmosis (SWRO) plant is based on membrane technology. This paper discusses various aspects of coupling of desalination plant with nuclear reactors and also discusses salient features of hybridization of thermal and membrane technologies

  18. Preliminary ecotoxicity assessment of new generation alternative fuels in seawater.

    Science.gov (United States)

    Rosen, Gunther; Dolecal, Renee E; Colvin, Marienne A; George, Robert D

    2014-06-01

    The United States Navy (USN) is currently demonstrating the viability of environmentally sustainable alternative fuels to power its fleet comprised of aircraft and ships. As with any fuel used in a maritime setting, there is potential for introduction into the environment through transport, storage, and spills. However, while alternative fuels are often presumed to be eco-friendly relative to conventional petroleum-based fuels, their environmental fate and effects on marine environments are essentially unknown. Here, standard laboratory-based toxicity experiments were conducted for two alternative fuels, jet fuel derived from Camelina sativa (wild flax) seeds (HRJ5) and diesel fuel derived from algae (HRD76), and two conventional counterparts, jet fuel (JP5) and ship diesel (F76). Initial toxicity tests performed on water-accommodated fractions (WAF) from neat fuels partitioned into seawater, using four standard marine species in acute and chronic/sublethal tests, indicate that the alternative fuels are significantly less toxic to marine organisms. Published by Elsevier Ltd.

  19. Radionuclides in sediments and seawater at Rongelap Atoll

    Energy Technology Data Exchange (ETDEWEB)

    Noshkin, V.E.; Robison, W.L.; Eagle, R.J.; Brunk, J.L.

    1998-03-01

    The present concentrations and distributions of long-lived, man-made radionuclides in Rongelap Atoll lagoon surface sediments, based on samples collected and analyzed in this report. The radionuclides were associated with debris generated with the 1954 Bravo thermonuclear test at Bikini Atoll. Presently, only {sup 90}Sr and the transuranic radionuclides are found associated with the surface sediments in any quantity. Other radionuclides, including {sup 60}Co and {sup 137} Cs, are virtually absent and have either decayed or migrated from the deposits to the overlying seawater. Present inventories of {sup 241}Am and {sup 249+240}Pu in the surface layer at Rongelap are estimated to be 3% of the respective inventories in surface sediments from Bikini Atoll. There is a continuous slow release of the transuranics from the sediments back to the water column. The inventories will only slowly change with time unless the chemical-physical processes that now regulate this release to the water column are changed or altered.

  20. Impact of Acid Cleaning on the Performance of PVDF UF Membranes in Seawater Reverse Osmosis Pretreatment

    KAUST Repository

    Alsogair, Safiya

    2016-01-01

    required to maintain the characteristics of the membrane. This research was made with the purpose of investigating the effects of acid cleaning during chemically enhanced backwashing (CEB) on the performance of ultrafiltration (UF) membranes in seawater

  1. Optimal scheduling of biocide dosing for seawater-cooled power and desalination plants

    KAUST Repository

    Mahfouz, Abdullah Bin; Atilhan, Selma; Batchelor, Bill; Linke, Patrick; Abdel-Wahab, Ahmed; El-Halwagi, Mahmoud M.

    2011-01-01

    Thermal desalination systems are typically integrated with power plants to exploit the excess heat resulting from the power-generation units. Using seawater in cooling the power plant and the desalination system is a common practice in many parts

  2. Bicarbonate Elution of Uranium from Amidoxime-Based Polymer Adsorbents for Sequestering Uranium from Seawater

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Horng-Bin [Department of Chemistry, University of Idaho, Moscow, Idaho 83844 USA; Wai, Chien M. [Department of Chemistry, University of Idaho, Moscow, Idaho 83844 USA; Kuo, Li-Jung [Pacific Northwest National Laboratory, Marine Sciences Laboratory, Sequim, Washington 98382 USA; Gill, Gary [Pacific Northwest National Laboratory, Marine Sciences Laboratory, Sequim, Washington 98382 USA; Tian, Guoxin [Lawrence Berkeley National Laboratory, Berkeley, California 94720 USA; Rao, Linfeng [Lawrence Berkeley National Laboratory, Berkeley, California 94720 USA; Das, Sadananda [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 USA; Mayes, Richard T. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 USA; Janke, Christopher J. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 USA

    2017-05-02

    Uranium adsorbed on amidoxime-based polyethylene fibers in simulated seawater can be quantitatively eluted using 3 M KHCO3 at 40°C. Thermodynamic calculations are in agreement with the experimental observation that at high bicarbonate concentrations (3 M) uranyl ions bound to amidoxime molecules are converted to uranyl tris-carbonato complex in the aqueous solution. The elution process is basically the reverse reaction of the uranium adsorption process which occurs at a very low bicarbonate concentration (~10-3 M) in seawater. In real seawater experiments, the bicarbonate elution is followed by a NaOH treatment to remove natural organic matter adsorbed on the polymer adsorbent. Using the sequential bicarbonate and NaOH elution, the adsorbent is reusable after rinsing with deionized water and the recycled adsorbent shows no loss of uranium loading capacity based on real seawater experiments.

  3. Novel extractants with high selectivity for valuable metals in seawater. Calixarene derivatives

    International Nuclear Information System (INIS)

    Kakoi, Takahiko; Goto, Masahiro

    1997-01-01

    Seawater contains various valuable metals such as uranium and lithium. Therefore, attempts are being made to develop highly selective extractants which recognize target metal ions in reclaimed seawater. In this review, we have focused our study on the application of novel cyclic compound calixarene based extractants. A novel host compound calixarene, which is a cyclic compound connecting some phenol rings, is capable of forming several different extractant ring sizes and introducing various kinds of functional groups towards targeting of metal ions in seawater. Therefore, calixarene derivatives are capable of extracting valuable metals such as uranium, alkaline metals, heavy metals, rare earth metals and noble metals selectively by varying structural ring size and functional groups. The novel host compound calixarene has given promising results which line it up as a potential extractant for the separation of valuable metal ions in seawater. (author)

  4. State of art and tendency of uranium extraction from seawater abroad

    International Nuclear Information System (INIS)

    Zhang Jinrui

    1995-01-01

    The amount of the natural resources in land is becoming smaller and smaller, and the people places hopes on the oceans. This paper describes and discusses the new achievements in the research of uranium extraction from seawater abroad

  5. 87Sr enrichment of ophiolitic sulphide deposits in Cyprus confirms ore formation by circulating seawater

    International Nuclear Information System (INIS)

    Chapman, H.J.; Spooner, E.T.C.

    1977-01-01

    The hypothesis that seawater was the source of the hydrothermal fluid which formed the Upper Cretaceous ophiolitic cupriferous pyrite ore deposits of the Troodos Massif (Cyprus) has been tested by analysing the strontium isotopic composition of thirteen mineralized samples from four mines. Initial 87 Sr/ 86 Sr ratios range from 0.7052+-0.0001 to 0.7075+-0.00002, the latter value being indistinguishable from that of Upper Cretaceous seawater at 0.7076+-0.0006 (2 sigma). Hence, the mineralized metabasalt samples have been contaminated with 87 Sr, relative to initial magmatic strontium isotope ratios of the Troodos ophiolitic complex (0.70338+-0.00010 to 0.70365+-0.00005). Since seawater was the only source of strontium available during formation of the Troodos Complex which was isotopically relatively enriched in 87 Sr, the data confirm that seawater was the source of the hydrothermal oreforming fluid. (Auth.)

  6. Improvement of 137Cs analysis in small volume seawater samples using the Ogoya underground facility

    International Nuclear Information System (INIS)

    Hirose, K.; Komura, K.; Kanazawa University, Ishikawa; Aoyama, M.; Igarashi, Y.

    2008-01-01

    137 Cs in seawater is one of the most powerful tracers of water motion. Large volumes of samples have been required for determination of 137 Cs in seawater. This paper describes improvement of separation and purification processes of 137 Cs in seawater, which includes purification of 137 Cs using hexachloroplatinic acid in addition to ammonium phosphomolybdate (AMP) precipitation. As a result, we succeeded the 137 Cs determination in seawater with a smaller sample volume of 10 liter by using ultra-low background gamma-spectrometry in the Ogoya underground facility. 137 Cs detection limit was about 0.1 mBq (counting time: 10 6 s). This method is applied to determine 137 Cs in small samples of the South Pacific deep waters. (author)

  7. Long-term market prospects/demand for seawater desalination for municipal supply

    International Nuclear Information System (INIS)

    Furukawa, D.H.; Zimerman, Z.

    1996-01-01

    The current status of the seawater desalination market was reviewed, and the expected evolution of installed capacities up to the year 2015 was projected in five year intervals by: Individual countries; unit size; desalination process used. 2 refs, 2 figs

  8. Removal of oil pollutants in seawater as pretreatment of reverse osmosis desalination process

    Energy Technology Data Exchange (ETDEWEB)

    Wen Jian; Nishijima, Wataru; Baes, Aloysius U.; Okada, Mitsumasa [Hiroshima Univ., Environmental Science Dept., Hiroshima (Japan); Kitanaka, Atsushi [Fuji-Electric Corporate Research and Development Ltd., Yokosuka, Kanagawa (Japan)

    1999-11-01

    Weathered oil contaminated seawater (WOCS) was used to investigate the behaviour of soluble oil components in seawater in various pretreatment processes for removal of oil pollutants in seawater. The various pretreatment processes were a reverse osmosis desalination process in combination with advanced oxidation processes, ultrafiltration, coagulation, GAC adsorption, biological treatment and separation with a low pressure RO membrane. WOCS was prepared by mixing oil, nutrients and fresh seawater which was exposed to sunlight to simulate photooxidation and microbial degradation of oil in the marine environment. It was found that WOCS contained soluble components with relatively small molecular size, which are refractory to biodegradation and difficult to remove by advanced oxidation processes (AOPs), UF membrane or coagulation using FeCl{sub 3} or PAC as flocculants. However, DOC in WOCS (OCWOCS) was easily adsorbed to GAC. Low pressure RO membranes with higher salt rejection rate could remove more OCWOCS compared to those of lower salt rejection rate. (Author)

  9. Removal of oil pollutants in seawater as pretreatment of reverse osmosis desalination process

    Energy Technology Data Exchange (ETDEWEB)

    Wen Jian; Nishijima, Wataru; Baes, Aloysius U.; Okada, Mitsumasa [Hiroshima Univ., Environmental Science Dept., Hiroshima (Japan); Kitanaka, Atsushi [Fuji-Electric Corporate Research and Development Ltd., Yokosuka, Kanagawa (Japan)

    1999-07-01

    Weathered oil contaminated seawater (WOCS) was used to investigate the behaviour of soluble oil components in seawater in various pretreatment processes for removal of oil pollutants in seawater. The various pretreatment processes were a reverse osmosis desalination process in combination with advanced oxidation processes, ultrafiltration, coagulation, GAC adsorption, biological treatment and separation with a low pressure RO membrane. WOCS was prepared by mixing oil, nutrients and fresh seawater which was exposed to sunlight to simulate photooxidation and microbial degradation of oil in the marine environment. It was found that WOCS contained soluble components with relatively small molecular size, which are refractory to biodegradation and difficult to remove by advanced oxidation processes (AOPs), UF membrane or coagulation using FeCl{sub 3} or PAC as flocculants. However, DOC in WOCS (OCWOCS) was easily adsorbed to GAC. Low pressure RO membranes with higher salt rejection rate could remove more OCWOCS compared to those of lower salt rejection rate. (Author)

  10. Distribution of 137Cs in surface seawater and sediment around Sabahs Sulu-Sulawesi Sea

    International Nuclear Information System (INIS)

    Mohd Izwan Abdul Aziz; Ahmad Sanadi Abu Bakar; Yii, Mei Wo; Nurrul Assyikeen Jaffary; Zaharudin Ahmad

    2010-01-01

    The studies on distribution of 137 Cs in surface seawater and sediment around Sabahs Sulu-Sulawesi Sea were carried out during Ekspedisi Pelayaran Saintifik Perdana (EPSP) in July 2009. About sixteen and twenty five sampling locations were identified for surface seawater and sediment respectively in Sabahs Sulu-Sulawesi Sea. Large volumes of seawater samples are collected and co-precipitation technique was employed to concentrate cesium content before known amounts of 134 Cs tracer were added as yield determinant. Grab sampler were used to collect surface sediment sample. The caesium precipitate and sediment were dried and finely ground before counted using gamma-ray spectrometry system at 661 keV. The activity of 137 Cs was found in surface seawater and sediment to be in the range 1.73 Bq/ m 3 to 5.50 Bq/ m 3 and 1.15 Bq/ kg to 4.53 Bq/ kg respectively. (author)

  11. Effectiveness of seawater reverse osmosis (SWRO) pretreatment systems in removing transparent exopolymer particles (TEP) substances

    KAUST Repository

    Lee, Shang-Tse

    2015-01-01

    Transparent exopolymer particles (TEP) have been reported as one of the main factors of membrane fouling in seawater reverse osmosis (SWRO) process. Research has been focused on algal TEP so far, overlooking bacterial TEP. This thesis investigated

  12. Fouling of Seawater Reverse Osmosis (SWRO) Membrane: Chemical and Microbiological Characterization

    KAUST Repository

    Khan, Muhammad T.

    2013-01-01

    In spite of abundant water resources, world is suffering from the scarcity of usable water. Seawater Reverse Osmosis (SWRO) desalination technology using polymeric membranes has been recognized as a key solution to water scarcity problem. However

  13. Development of pre-concentration procedure for the determination of Hg isotope ratios in seawater samples

    International Nuclear Information System (INIS)

    Štrok, Marko; Hintelmann, Holger; Dimock, Brian

    2014-01-01

    Highlights: • The method for the quantitative pre-concentration of Hg from seawater was developed. • First report of Hg isotope ratios in seawater is presented. • A unique mass independent 200 Hg isotope fractionation was observed. • This fractionation has unique potential to distinguish anthropogenic and natural Hg. - Abstract: Hg concentrations in seawater are usually too low to allow direct (without pre-concentration and removal of salt matrix) measurement of its isotope ratios with multicollector-inductively coupled plasma mass spectrometry (MC-ICP-MS). Therefore, a new method for the pre-concentration of Hg from large volumes of seawater was developed. The final method allows for relatively fast (about 2.5 L h −1 ) and quantitative pre-concentration of Hg from seawater samples with an average Hg recovery of 98 ± 6%. Using this newly developed method we determined Hg isotope ratios in seawater. Reference seawater samples were compared to samples potentially impacted by anthropogenic activity. The results show negative mass dependent fractionation relative to the NIST 3133 Hg standard with δ 202 Hg values in the range from −0.50‰ to −1.50‰. In addition, positive mass independent fractionation of 200 Hg was observed for samples from reference sites, while impacted sites did not show significant Δ 200 Hg values. Although the influence of the impacted sediments is limited to the seawater and particulate matter in very close proximity to the sediment, this observation may raise the possibility of using Δ 200 Hg to distinguish between samples from impacted and reference sites

  14. Assessing the pollution risk of a groundwater source field at western Laizhou Bay under seawater intrusion

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Xiankui; Wu, Jichun; Wang, Dong, E-mail: wangdong@nju.edu.cn; Zhu, Xiaobin

    2016-07-15

    Coastal areas have great significance for human living, economy and society development in the world. With the rapid increase of pressures from human activities and climate change, the safety of groundwater resource is under the threat of seawater intrusion in coastal areas. The area of Laizhou Bay is one of the most serious seawater intruded areas in China, since seawater intrusion phenomenon was firstly recognized in the middle of 1970s. This study assessed the pollution risk of a groundwater source filed of western Laizhou Bay area by inferring the probability distribution of groundwater Cl{sup −} concentration. The numerical model of seawater intrusion process is built by using SEAWAT4. The parameter uncertainty of this model is evaluated by Markov Chain Monte Carlo (MCMC) simulation, and DREAM{sub (ZS)} is used as sampling algorithm. Then, the predictive distribution of Cl{sup -} concentration at groundwater source field is inferred by using the samples of model parameters obtained from MCMC. After that, the pollution risk of groundwater source filed is assessed by the predictive quantiles of Cl{sup -} concentration. The results of model calibration and verification demonstrate that the DREAM{sub (ZS)} based MCMC is efficient and reliable to estimate model parameters under current observation. Under the condition of 95% confidence level, the groundwater source point will not be polluted by seawater intrusion in future five years (2015–2019). In addition, the 2.5% and 97.5% predictive quantiles show that the Cl{sup −} concentration of groundwater source field always vary between 175 mg/l and 200 mg/l. - Highlights: • The parameter uncertainty of seawater intrusion model is evaluated by MCMC. • Groundwater source field won’t be polluted by seawater intrusion in future 5 years. • The pollution risk is assessed by the predictive quantiles of Cl{sup −} concentration.

  15. Application of Geophysical Method for Determining Seawater Intrusion in Coastal Aquifer

    International Nuclear Information System (INIS)

    Mohd Muzamil Mohd Hashim; Kamarudin Samuding; Mohd Hafiz Zawawi; Daung, J.A.D.; Mohd Hafiz Zulkurnain; Kamaruzaman Mohamad

    2016-01-01

    A study of seawater intrusion has been proposed in the coastal area of Pahang. Electrical resistivity tomography (ERT) is a geophysical technique that used in this study. The survey was conducted at UMP, Tanjung Batu and Nenasi using Wenner-Schlumberger protocol. Electrical resistivity profile obtained from the survey indicates an area with low resistivity value (<5Ωm) associated with the resistivity value of seawater. (author)

  16. Assessing the pollution risk of a groundwater source field at western Laizhou Bay under seawater intrusion

    International Nuclear Information System (INIS)

    Zeng, Xiankui; Wu, Jichun; Wang, Dong; Zhu, Xiaobin

    2016-01-01

    Coastal areas have great significance for human living, economy and society development in the world. With the rapid increase of pressures from human activities and climate change, the safety of groundwater resource is under the threat of seawater intrusion in coastal areas. The area of Laizhou Bay is one of the most serious seawater intruded areas in China, since seawater intrusion phenomenon was firstly recognized in the middle of 1970s. This study assessed the pollution risk of a groundwater source filed of western Laizhou Bay area by inferring the probability distribution of groundwater Cl − concentration. The numerical model of seawater intrusion process is built by using SEAWAT4. The parameter uncertainty of this model is evaluated by Markov Chain Monte Carlo (MCMC) simulation, and DREAM (ZS) is used as sampling algorithm. Then, the predictive distribution of Cl - concentration at groundwater source field is inferred by using the samples of model parameters obtained from MCMC. After that, the pollution risk of groundwater source filed is assessed by the predictive quantiles of Cl - concentration. The results of model calibration and verification demonstrate that the DREAM (ZS) based MCMC is efficient and reliable to estimate model parameters under current observation. Under the condition of 95% confidence level, the groundwater source point will not be polluted by seawater intrusion in future five years (2015–2019). In addition, the 2.5% and 97.5% predictive quantiles show that the Cl − concentration of groundwater source field always vary between 175 mg/l and 200 mg/l. - Highlights: • The parameter uncertainty of seawater intrusion model is evaluated by MCMC. • Groundwater source field won’t be polluted by seawater intrusion in future 5 years. • The pollution risk is assessed by the predictive quantiles of Cl − concentration

  17. Sulfide Production and Corrosion in Seawater During Exposure to FAME Alternative Fuel

    Science.gov (United States)

    2012-06-01

    transporting fatty acid methyl ester ( FAME ] alternative diesel fuel in contact with natural seawater under anaerobic conditions. Coastal Key West...Glycerol Fatty Acid Methyl Ester Exposure Chamber Anaerobic Chamber - bal. N2,10% H2, 0.1% C02 - maintain pH ~8 Polarization Resistance (Rp...and Corrosion in Seawater During Exposure to FAME Alternative Fuel Jason 5. Lee Richard I. Ray BrendaJ. Little Naval Research Laboratory Stennis

  18. Oxidative stress in the hydrocoral Millepora alcicornis exposed to CO2-driven seawater acidification

    Science.gov (United States)

    Luz, Débora Camacho; Zebral, Yuri Dornelles; Klein, Roberta Daniele; Marques, Joseane Aparecida; Marangoni, Laura Fernandes de Barros; Pereira, Cristiano Macedo; Duarte, Gustavo Adolpho Santos; Pires, Débora de Oliveira; Castro, Clovis Barreira e.; Calderon, Emiliano Nicolas; Bianchini, Adalto

    2018-06-01

    Global impacts are affecting negatively coral reefs' health worldwide. Ocean acidification associated with the increasing CO2 partial pressure in the atmosphere can potentially induce oxidative stress with consequent cellular damage in corals and hydrocorals. In the present study, parameters related to oxidative status were evaluated in the hydrocoral Millepora alcicornis exposed to three different levels of seawater acidification using a mesocosm system. CO2-driven acidification of seawater was performed until reaching 0.3, 0.6 and 0.9 pH units below the current pH of seawater pumped from the coral reef adjacent to the mesocosm. Therefore, treatments corresponded to control (pH 8.1), mild (pH 7.8), intermediate (pH 7.5) and severe (pH 7.2) seawater acidification. After 0, 16 and 30 d of exposure, hydrocorals were collected and the following parameters were analyzed in the holobiont: antioxidant capacity against peroxyl radicals (ACAP), total glutathione (GSHt) concentration, reduced (GSH) and oxidized (GSSG) glutathione ratio (GSH/GSSG), lipid peroxidation (LPO) and protein carbonyl group (PC) levels. ACAP was increased in hydrocorals after 16 d of exposure to intermediate levels of seawater acidification. GSHt and GSH/GSSG did not change over the experimental period. LPO was increased at any level of seawater acidification, while PC content was increased in hydrocorals exposed to intermediate and severe seawater acidification for 30 d. These findings indicate that the antioxidant defense system of M. alcicornis is capable of coping with acidic conditions for a short period of time (16 d). Additionally, they clearly show that a long-term (30 d) exposure to seawater acidification induces oxidative stress with consequent oxidative damage to lipids and proteins, which could compromise hydrocoral health.

  19. Impact of seawater carbonate chemistry on the calcification of marine bivalves

    OpenAIRE

    Thomsen Jörn; Haynert Kristin; Wegner K Mathias; Melzner Frank

    2015-01-01

    Bivalve calcification, particular of the early larval stages is highly sensitive to the change of ocean carbonate chemistry resulting from atmospheric CO2 uptake. Earlier studies suggested that declining seawater [CO32−] and thereby lowered carbonate saturation affect shell production. However, disturbances of physiological processes such as acid-base regulation by adverse seawater pCO2 and pH can affect calcification in a secondary fashion. In order to determine the e...

  20. On the influence of adsorber performance on plant design for the extraction of uranium from seawater

    International Nuclear Information System (INIS)

    Koske, P.H.; Ohlrogge, K.

    1983-01-01

    Based on simple seawater and dissolved uranium balances the influence of specific adsorber parameters on size and design of production plants with fluidized adsorber beds for the extraction of uranium from seawater is discussed. Besides a critical review of two recently published plant designs in the USA and Japan experimentally determined adsorber data for a polyamidoxim (PAO) granulate are presented together with an evaluation of their influence on the key plant parameters. (orig.) [de

  1. Determination of thorium in seawater by neutron activation analysis and mass spectrometry

    International Nuclear Information System (INIS)

    Huh, Chih-An.

    1987-01-01

    The recent development of neutron activation analysis and mass spectrometric methods for the determination of 232 Th in seawater has made possible rapid sampling and analysis of this long-lived, non-radiogenic thorium isotope on small-volume samples. The marine geochemical utility of 232 Th, whose concentration in seawater is extremely low, warrants the development of these sensitive techniques. The analytical methods and some results are presented and discussed in this article. 24 refs., 3 figs

  2. The adsorber loop concept for the contact between seawater and adsorber granulate

    International Nuclear Information System (INIS)

    Koske, P.H.; Ohlrogge, K.

    1984-01-01

    The present paper deals with the so-called ''adsorber loop concept'' in which the adsorber granulate is carried along with the seawater to be processed in a loop-like configuration and is separated again from the depleted water before this is leaving the adsorption unit. This concept enables high seawater velocities thus reducing the required bed area. Theoretical considerations are presented together with experimental results from field tests. (orig.) [de

  3. Seawater Durability of Nano-Montmorillonite Modified Single-Lap Joining Epoxy Composite Laminates

    OpenAIRE

    ULUS, Hasan; KAYBAL, Halil Burak; DEMİR, Okan; TATAR, Ahmet Caner; SENYURT, Muhammed Ali; AVCI, Ahmet

    2018-01-01

    The objective of this study was to investigate of nano-montmorillonite modified epoxy composite single-lap bonded joints, after being exposed to seawater immersion in order to understand the effect of seawater environment on their performance. To prepare the nano adhesives, nano montmorillonite (2 wt %) was incorporated into epoxy resin. Composite bonded specimens which manufactured with VARIM (Vacuum Assisted Resin Infusion Method) were prepared accordance with ASTM D5868-01 and immersed in ...

  4. Effect of the scale inhibitor on ion content in reverse osmosis system for seawater desalination

    Science.gov (United States)

    Gao, Yuhua; Liu, Zhenfa; Zhang, Lihui; Li, Haihua

    2017-09-01

    A scale inhibitor was synthesized from polysuccinimide with 2-aminoethanesulfonic acid and aspartic acid. The effect of scale inhibitor on ion content in reverse osmosis system for seawater desalination was studied. The results showed that the ion content of permeate water is lower with the scale inhibitor added in RO system for seawater desalination than without scale inhibitor. On the contrary, the ion content of concentrate water is higher when with scale inhibitor in RO system.

  5. A Simulation-Optimization Model for Seawater Intrusion Management at Pingtung Coastal Area, Taiwan

    Directory of Open Access Journals (Sweden)

    Po-Syun Huang

    2018-02-01

    Full Text Available The coastal regions of Pingtung Plain in southern Taiwan rely on groundwater as their main source of fresh water for aquaculture, agriculture, domestic, and industrial sectors. The availability of fresh groundwater is threatened by unsustainable groundwater extraction and the over-pumpage leads to the serious problem of seawater intrusion. It is desired to find appropriate management strategies to control groundwater salinity and mitigate seawater intrusion. In this study, a simulation–optimization model has been presented to solve the problem of seawater intrusion along the coastal aquifers in Pingtung Plain and the objective is using injection well barriers and minimizing the total injection rate based on the pre-determined locations of injection barriers. The SEAWAT code is used to simulate the process of seawater intrusion and the surrogate model of artificial neural networks (ANNs is used to approximate the seawater intrusion (SWI numerical model to increase the computational efficiency during the optimization process. The heuristic optimization scheme of differential evolution (DE algorithm is selected to identify the global optimal management solution. Two different management scenarios, one is the injection barriers located along the coast and the other is the injection barrier located at the inland, are considered and the optimized results show that the deployment of injection barriers at the inland is more effective to reduce total dissolved solids (TDS concentrations and mitigate seawater intrusion than that along the coast. The computational time can be reduced by more than 98% when using ANNs to replace the numerical model and the DE algorithm has been confirmed as a robust optimization scheme to solve groundwater management problems. The proposed framework can identify the most reliable management strategies and provide a reference tool for decision making with regard to seawater intrusion remediation.

  6. Studies on rare earth elements in seawater and uptake by marine organisms

    International Nuclear Information System (INIS)

    Suzuki, H.; Koyanagi, T.; Saiki, M.

    1975-01-01

    The contents of rare earth elements in marine environmental samples were determined by neutron activation analysis to examine the existing state in coastal seawater and the concentration by marine organisms of the elements. Seawater was filtered through a Millipore filter GS (pore size 0.22 μm), before the analysis. Some of the seawater was treated with HC1 solution before filtration and some after filtration. Certain marine organisms were also analysed for determination of rare earth elements. These were: flounder (Paralichthys olivaceus); yellowtails (Seriola quinqueradiata); immature anchovy (Engraulis japonica); clams (Meretrix lusoria); green algae (Ulva pertusa); brown algae (Hizikia fusiforme, Sargassum fulvellum, Undaria pinnatifida). In the seawater without HC1 treatment before filtration, considerable amounts of the elements existed in residue on the filter, whereas in the seawater treated with HC1 before filtration, the greater part remained in the dissolved state. Concentration factors calculated from the contents of stable elements, therefore, are affected remarkably by the existing state of the elements in seawater. If only the dissolved state is assumed available for marine organisms, values one order higher are attained compared with the case where total amounts of the elements were used for the calculation. However, the contribution of the insoluble state seems to be not negligible with some organisms. The higher concentration factors for immature anchovy and clams observed in this study were considered to be caused by surface adsorption of elements in particulate form and also ingested sediment with high element concentration. (author)

  7. Extraction of uranium from seawater: chemical process and plant design feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, M.H.; Frame, J.M.; Dudey, N.D.; Kiel, G.R.; Mesec, V.; Woodfield, F.W.; Binney, S.E.; Jante, M.R.; Anderson, R.C.; Clark, G.T.

    1979-02-01

    A major assessment was made of the uranium resources in seawater. Several concepts for moving seawater to recover the uranium were investigated, including pumping the seawater and using natural ocean currents or tides directly. The optimal site chosen was on the southeastern Puerto Rico coast, with the south U.S. Atlantic coast as an alternate. The various processes for extracting uranium from seawater were reviewed, with the adsorption process being the most promising at the present time. Of the possible adsorbents, hydrous titanium oxide was found to have the best properties. A uranium extraction plant was conceptually designed. Of the possible methods for contacting the seawater with the adsorbent, a continuous fluidized bed concept was chosen as most practical for a pumped system. A plant recovering 500 tonnes of U/sub 3/O/sub 8/ per year requires 5900 cubic meters per second of seawater to be pumped through the adsorbent beds for a 70% overall recovery efficiency. Total cost of the plant was estimated to be about $6.2 billion. A computer model for the process was used for parametric sensitivity studies and economic projections. Several design case variations were developed. Other topics addressed were the impact of co-product recovery, environmental considerations, etc.

  8. Bioaccumulation of PCBs in the cuttlefish Sepia officinalis from seawater, sediment and food pathways

    International Nuclear Information System (INIS)

    Danis, B.; Bustamante, P.; Cotret, O.; Teyssie, J.L.; Fowler, S.W.; Warnau, M.

    2005-01-01

    The cuttlefish Sepia officinalis was selected as a model cephalopod to study PCB bioaccumulation via seawater, sediments and food. Newly hatched, juvenile cuttlefish were exposed for 17 days to environmentally realistic concentrations of 14 C-labeled 2,2',4,4',5,5'-hexachlorobiphenyl (PCB no. 153) (18 ng PCB l -1 seawater; 30 ng PCB g -1 dry wt sediments; Artemia salina exposed to 18 ng PCB l -1 seawater). Accumulation of PCB no. 153 was followed in three body compartments: digestive gland, cuttlebone and the combined remaining tissues. Results showed that (1) uptake kinetics were source- and body compartment-dependent, (2) for each body compartment, the accumulation was far greater when S. officinalis was exposed via seawater, (3) the cuttlebone accumulated little of the contaminant regardless of the source, and (4) the PCB congener showed a similar distribution pattern among the different body compartments following exposure to contaminated seawater, sediment or food with the lowest concentrations in the cuttlebone and the highest in the remaining tissues. The use of radiotracer techniques allowed delineating PCB kinetics in small whole organisms as well as in their separate tissues. The results underscore the enhanced ability of cephalopods to concentrate organic pollutants such as PCBs, and raise the question of potential risk to their predators in contaminated areas. - Bioaccumulation of PCBs by cuttlefish is studied, via seawater, sediments and their food

  9. The status quo and the prospect of extraction of resources in seawater

    International Nuclear Information System (INIS)

    Katoh, Shunsaku

    1991-01-01

    Sea is the natural storage, and the enormous quantity of river water which contains the large amount of ions and compositions flows into sea, accordingly it has been calculated that seawater is replaced with new water in about 4 x 10 4 years. Sea is always agitated by tidal current, therefore, the composition of seawater is nearly uniform in most sea areas. Almost all elements existing in nature are dissolved in seawater, and the state of dissolution of main elements and their concentration are shown. The total quantity of seawater is as enormous as 1.35 x 10 9 km 3 , accordingly even in the trace elements in seawater, the total dissolved amount is enormous. For Japan which lacks resources, it is the important subject to develop the technology of effectively utilizing the resources in sea. The methods of obtaining sodium chloride, magnesium, bromine and potassium, which are the main components of seawater, are briefly explained. As the extraction of trace components, gold and silver, uranium, lithium, boron, strontium, vanadium, molybdenum, yttrium and heavy water are taken up. The optimal system must be built including the development of high performance adsorbents. (K.I.)

  10. Conceptual model: possible changes of the seawater uranium isotopic composition through time

    Energy Technology Data Exchange (ETDEWEB)

    Nowitzki, Hannah; Frank, Norbert; Fohlmeister, Jens [Universitaet Heidelberg (Germany)

    2015-07-01

    U behaves in seawater like a conservative element. More than 99% of the oceanic U content is {sup 238}U, whereas {sup 234}U is only present in trace amounts. As the residence time of U is significantly longer than the mixing time of the ocean, the ocean is well mixed with respect to U and its isotopic composition (Dunk 2002). Moreover, living corals incorporate U without isotopic fractionation. Therefore, the past seawater isotopic evolution of ({sup 234}U/{sup 238}U) can be accessed via U/Th age-dating of corals and the subsequent calculation of the initial ({sup 234}U/{sup 238}U) value. The isotopic ({sup 234}U/{sup 238}U) composition of seawater during the last 360 ka scatters around the modern seawater value (δ{sup 234}U ∼ (145±15) %, Henderson 2002). As these variations in the δ{sup 234}U value are rather small, a 'constant seawater isotopic composition hypothesis' is often used to validate U/Th ages of fossil corals. However, some authors find that the variability of the isotopic composition exceeds the expected range and suggest that it provides valuable information on variations in continental weathering and global run-off fluctuations or sea-level changes. This work will attempt to compare literature data of the seawater U isotopic composition to the results of a conceptual box-model of the oceanic U budget.

  11. Extraction of uranium from seawater: chemical process and plant design feasibility study

    International Nuclear Information System (INIS)

    Campbell, M.H.; Frame, J.M.; Dudey, N.D.; Kiel, G.R.; Mesec, V.; Woodfield, F.W.; Binney, S.E.; Jante, M.R.; Anderson, R.C.; Clark, G.T.

    1979-02-01

    A major assessment was made of the uranium resources in seawater. Several concepts for moving seawater to recover the uranium were investigated, including pumping the seawater and using natural ocean currents or tides directly. The optimal site chosen was on the southeastern Puerto Rico coast, with the south U.S. Atlantic coast as an alternate. The various processes for extracting uranium from seawater were reviewed, with the adsorption process being the most promising at the present time. Of the possible adsorbents, hydrous titanium oxide was found to have the best properties. A uranium extraction plant was conceptually designed. Of the possible methods for contacting the seawater with the adsorbent, a continuous fluidized bed concept was chosen as most practical for a pumped system. A plant recovering 500 tonnes of U 3 O 8 per year requires 5900 cubic meters per second of seawater to be pumped through the adsorbent beds for a 70% overall recovery efficiency. Total cost of the plant was estimated to be about $6.2 billion. A computer model for the process was used for parametric sensitivity studies and economic projections. Several design case variations were developed. Other topics addressed were the impact of co-product recovery, environmental considerations, etc

  12. Responses of an Agricultural Soil Microbiome to Flooding with Seawater after Managed Coastal Realignment

    Directory of Open Access Journals (Sweden)

    Kamilla S. Sjøgaard

    2018-01-01

    Full Text Available Coastal areas have become more prone to flooding with seawater due to climate-change-induced sea-level rise and intensified storm surges. One way to cope with this issue is by “managed coastal realignment”, where low-lying coastal areas are no longer protected and instead flooded with seawater. How flooding with seawater impacts soil microbiomes and the biogeochemical cycling of elements is poorly understood. To address this, we conducted a microcosm experiment using soil cores collected at the nature restoration project site Gyldensteen Strand (Denmark, which were flooded with seawater and monitored over six months. Throughout the experiment, biogeochemical analyses, microbial community fingerprinting and the quantification of marker genes documented clear shifts in microbiome composition and activity. The flooding with seawater initially resulted in accelerated heterotrophic activity that entailed high ammonium production and net removal of nitrogen from the system, also demonstrated by a concurrent increase in the abundances of marker genes for ammonium oxidation and denitrification. Due to the depletion of labile soil organic matter, microbial activity decreased after approximately four months. The event of flooding caused the largest shifts in microbiome composition with the availability of labile organic matter subsequently being the most important driver for the succession in microbiome composition in soils flooded with seawater.

  13. Cultivation of oleaginous Rhodotorula mucilaginosa in airlift bioreactor by using seawater.

    Science.gov (United States)

    Yen, Hong-Wei; Liao, Yu-Ting; Liu, Yi Xian

    2016-02-01

    The enormous water resource consumption is a concern to the scale-up fermentation process, especially for those cheap fermentation commodities, such as microbial oils as the feedstock for biodiesel production. The direct cultivation of oleaginous Rhodotorula mucilaginosa in a 5-L airlift bioreactor using seawater instead of pure water led to a slightly lower biomass being achieved, at 17.2 compared to 18.1 g/L, respectively. Nevertheless, a higher lipid content of 65 ± 5% was measured in the batch using seawater as compared to the pure water batch. Both the salinity and osmotic pressure decreased as the cultivation time increased in the seawater batch, and these effects may contribute to the high tolerance for salinity. No effects were observed for the seawater on the fatty acid profiles. The major components for both batches using seawater and pure water were C16:0 (palmitic acid), C18:1 (oleic acid) and C18:2 (linoleic acid), which together accounted for over 85% of total lipids. The results of this study indicated that seawater could be a suitable option for scaling up the growth of oleaginous R. mucilaginosa, especially from the perspective of water resource utilization. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  14. Model for the Assessment of Seawater Environmental Quality Based on Multiobjective Variable Fuzzy Set Theory

    Directory of Open Access Journals (Sweden)

    Lina Ke

    2013-01-01

    Full Text Available With the rapid development of marine economy industry, the activities for exploring and exploiting the marine resources are increasing, and there are more and more marine construction projects, which contribute to the growing trend of eutrophication and frequent occurrence of red tide. Thus, seawater quality has become the topic which the people generally cared about. The seawater quality evaluation could be considered as an analysis process which combined the evaluation indexes with certainty and evaluation factors with uncertainty and its changes. This paper built a model for the assessment of seawater environmental quality based on the multiobjective variable fuzzy set theory (VFEM. The Qingdao marine dumping site in China is taken as an evaluation example. Through the quantitative research of water-quality data from 2004 to 2008, the model is more reliable than other traditional methods, in which uncertainty and ambiguity of the seawater quality evaluation are considered, and trade the stable results as the final results of seawater quality evaluation, which effectively solved the impact of the fuzzy boundary of evaluation standard and monitoring error, is more suitable for evaluation of a multi-index, multilevel, and nonlinear marine environment system and has been proved to be an effective tool for seawater quality evaluation.

  15. Seawater spray injury to Quercus acutissima leaves: crystal deposition, stomatal clogging, and chloroplast degeneration.

    Science.gov (United States)

    Kim, Ki Woo; Koo, Kyosang; Kim, Pan-Gi

    2011-05-01

    Effects of seawater spray on leaf structure were investigated in Quercus acutissima by electron microscopy and X-ray microanalysis. Two-year-old seedlings of Q. acutissima were sprayed with seawater and kept in a greenhouse maintained at 25°C. The most recognizable symptoms of seawater-sprayed seedlings included leaf necrosis, crystal deposition, stomatal clogging, and chloroplast degeneration. Field emission scanning electron microscopy revealed that the leaf surface was covered with additional layers of remnants of seawater spray. Composed of sodium and chloride, cube-shaped crystals (halite) were prevalently found on trichomes and epidermis, and formed aggregates. Meanwhile, wedge-shaped crystals were deposited on epidermis and consisted of calcium and sulfur. As a result of stomatal clogging by crystal deposition on the abaxial surface, it was conceivable that plant respiration became severely hampered. Transmission electron microscopy showed degenerated cytoplasm of seawater-sprayed leaves. It was common to observe severe plasmolysis and disrupted chloroplasts with a reduced number of thylakoids in grana. These results indicate that foliar applications of seawater were sufficient to induce necrosis of Q. acutissima seedlings as an abiotic disturbance factor. Copyright © 2010 Wiley-Liss, Inc.

  16. Application of vacuum-assisted closure in seawater-immersed wound treatment under different negative pressures.

    Science.gov (United States)

    Cao, L; Peng, M M; Sun, J J; Yu, X C; Shi, B

    2015-06-11

    The therapeutic effect of vacuum-assisted closure (VAC) has been confirmed in many types of complex wounds, but there are few relevant reports regarding seawater-immersed wounds. The aim of this study was to determine the effect of VAC on seawater-immersed wound healing under different negative pressures and explore the optimal negative pressure value. Four purebred miniature pigs were used as the experimental animal models. Four acute, symmetrical wounds were made on each side of the spine and designated as the experimental group (wounds with 2 h of seawater immersion) and the control group (wounds without seawater immersion). Wounds were divided into a conventional dressing group and 3 further groups with different VAC therapies (negative pressure at either 120, 180, or 240 mmHg). The extent of wound healing, and speed of granulation growth and re-epithelialization were measured. Bacterial flora distribution in the wounds was observed, and fibronectin levels in the exudate of the wounds were tested. Results showed that seawater immersion aggravated wound injury and that VAC therapy with 180 mmHg negative pressure induced the fastest epidermis migration, obvious edema elimination, significant capillary proliferation, and the highest level of fibronectin, and that in wounds, the proportion of Gram-negative bacteria tended to decrease and that of Gram-positive bacteria tended to increase. Our results show that VAC promotes seawater-immersed wound healing and that 180 mmHg negative pressure may be optimal for wound healing.

  17. Development of pre-concentration procedure for the determination of Hg isotope ratios in seawater samples.

    Science.gov (United States)

    Štrok, Marko; Hintelmann, Holger; Dimock, Brian

    2014-12-03

    Hg concentrations in seawater are usually too low to allow direct (without pre-concentration and removal of salt matrix) measurement of its isotope ratios with multicollector-inductively coupled plasma mass spectrometry (MC-ICP-MS). Therefore, a new method for the pre-concentration of Hg from large volumes of seawater was developed. The final method allows for relatively fast (about 2.5Lh(-1)) and quantitative pre-concentration of Hg from seawater samples with an average Hg recovery of 98±6%. Using this newly developed method we determined Hg isotope ratios in seawater. Reference seawater samples were compared to samples potentially impacted by anthropogenic activity. The results show negative mass dependent fractionation relative to the NIST 3133 Hg standard with δ(202)Hg values in the range from -0.50‰ to -1.50‰. In addition, positive mass independent fractionation of (200)Hg was observed for samples from reference sites, while impacted sites did not show significant Δ(200)Hg values. Although the influence of the impacted sediments is limited to the seawater and particulate matter in very close proximity to the sediment, this observation may raise the possibility of using Δ(200)Hg to distinguish between samples from impacted and reference sites. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Vertical variability of seawater DMS in the South Pacific Ocean and its implication for atmospheric and surface seawater DMS.

    Science.gov (United States)

    Lee, Gangwoong; Park, Jooyoung; Jang, Yuwoon; Lee, Meehye; Kim, Kyung-Ryul; Oh, Jae-Ryoung; Kim, Dongseon; Yi, Hi-Il; Kim, Tong-Yup

    2010-02-01

    Shipboard measurements of atmospheric dimethylsulfide (DMS) and sea surface water DMS were performed aboard the R/V Onnuri across the South Pacific from Santiago, Chile to Fiji in February 2000. Hydrographic profiles of DMS, dissolved dimethylsulfoniopropionate (DMSP(d)), and particulate DMSP(p) in the upper 200m were obtained at 16 stations along the track. Atmospheric and sea surface water DMS concentrations ranged from 3 to 442pptv and from 0.1 to 19.9nM, respectively; the mean values of 61pptv and 2.1nM, respectively, were comparable to those from previous studies in the South Pacific. The South Pacific Gyre was distinguished by longitudinal-vertical distributions of DMS, DMSP(d), and DMSP(p), which was thought to be associated with the characteristic modification of biological activities that occurs mainly due to significant change in water temperature. The averaged DMS maximum appeared at 40m depth, whereas DMSP(p) and DMSP(d) maxima coincided with that of dissolved oxygen content at 60-80m. The sea-to-air fluxes of DMS were estimated to be 0.4-11.3micromold(-1)m(-2) (mean=2.8micromold(-1)m(-2)). A fairly good correlation between atmospheric DMS and sea-to-air DMS flux indicated that atmospheric DMS concentration was more sensitive to change in physical parameters than its photochemical removal process or surface seawater DMS concentrations.

  19. Microbial communities related to biodegradation of dispersed Macondo oil at low seawater temperature with Norwegian coastal seawater

    Science.gov (United States)

    Brakstad, Odd G; Throne-Holst, Mimmi; Netzer, Roman; Stoeckel, Donald M; Atlas, Ronald M

    2015-01-01

    The Deepwater Horizon (DWH) accident in 2010 created a deepwater plume of small oil droplets from a deepwater well in the Mississippi Canyon lease block 252 (‘Macondo oil’). A novel laboratory system was used in the current study to investigate biodegradation of Macondo oil dispersions (10 μm or 30 μm median droplet sizes) at low oil concentrations (2 mg l−1) in coastal Norwegian seawater at a temperature of 4–5°C. Whole metagenome analyses showed that oil biodegradation was associated with the successive increased abundances of Gammaproteobacteria, while Alphaproteobacteria (Pelagibacter) became dominant at the end of the experiment. Colwellia and Oceanospirillales were related to n-alkane biodegradation, while particularly Cycloclasticus and Marinobacter were associated with degradation of aromatic hydrocarbons (HCs). The larger oil droplet dispersions resulted in delayed sequential changes of Oceanospirillales and Cycloclasticus, related with slower degradation of alkanes and aromatic HCs. The bacterial successions associated with oil biodegradation showed both similarities and differences when compared with the results from DWH field samples and laboratory studies performed with deepwater from the Gulf of Mexico. PMID:26485443

  20. Dynamics of bacterial populations during bench-scale bioremediation of oily seawater and desert soil bioaugmented with coastal microbial mats.

    Science.gov (United States)

    Ali, Nidaa; Dashti, Narjes; Salamah, Samar; Sorkhoh, Naser; Al-Awadhi, Husain; Radwan, Samir

    2016-03-01

    This study describes a bench-scale attempt to bioremediate Kuwaiti, oily water and soil samples through bioaugmentation with coastal microbial mats rich in hydrocarbonoclastic bacterioflora. Seawater and desert soil samples were artificially polluted with 1% weathered oil, and bioaugmented with microbial mat suspensions. Oil removal and microbial community dynamics were monitored. In batch cultures, oil removal was more effective in soil than in seawater. Hydrocarbonoclastic bacteria associated with mat samples colonized soil more readily than seawater. The predominant oil degrading bacterium in seawater batches was the autochthonous seawater species Marinobacter hydrocarbonoclasticus. The main oil degraders in the inoculated soil samples, on the other hand, were a mixture of the autochthonous mat and desert soil bacteria; Xanthobacter tagetidis, Pseudomonas geniculata, Olivibacter ginsengisoli and others. More bacterial diversity prevailed in seawater during continuous than batch bioremediation. Out of seven hydrocarbonoclastic bacterial species isolated from those cultures, only one, Mycobacterium chlorophenolicum, was of mat origin. This result too confirms that most of the autochthonous mat bacteria failed to colonize seawater. Also culture-independent analysis of seawater from continuous cultures revealed high-bacterial diversity. Many of the bacteria belonged to the Alphaproteobacteria, Flavobacteria and Gammaproteobacteria, and were hydrocarbonoclastic. Optimal biostimulation practices for continuous culture bioremediation of seawater via mat bioaugmentation were adding the highest possible oil concentration as one lot in the beginning of bioremediation, addition of vitamins, and slowing down the seawater flow rate. © 2016 The Author. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  1. Forward osmosis niches in seawater desalination and wastewater reuse.

    Science.gov (United States)

    Valladares Linares, R; Li, Z; Sarp, S; Bucs, Sz S; Amy, G; Vrouwenvelder, J S

    2014-12-01

    This review focuses on the present status of forward osmosis (FO) niches in two main areas: seawater desalination and wastewater reuse. Specific applications for desalination and impaired-quality water treatment and reuse are described, as well as the benefits, advantages, challenges, costs and knowledge gaps on FO hybrid systems are discussed. FO can play a role as a bridge to integrate upstream and downstream water treatment processes, to reduce the energy consumption of the entire desalination or water recovery and reuse processes, thus achieving a sustainable solution for the water-energy nexus. FO hybrid membrane systems showed to have advantages over traditional membrane process like high pressure reverse osmosis and nanofiltration for desalination and wastewater treatment: (i) chemical storage and feed water systems may be reduced for capital, operational and maintenance cost, (ii) water quality is improved, (iii) reduced process piping costs, (iv) more flexible treatment units, and (v) higher overall sustainability of the desalination and wastewater treatment process. Nevertheless, major challenges make FO systems not yet a commercially viable technology, the most critical being the development of a high flux membrane, capable of maintaining an elevated salt rejection and a reduced internal concentration polarization effect, and the availability of appropriate draw solutions (cost effective and non-toxic), which can be recirculated via an efficient recovery process. This review article highlights the features of hybrid FO systems and specifically provides the state-of-the-art applications in the water industry in a novel classification and based on the latest developments toward scaling up these systems. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Pseudomonas oceani sp. nov., isolated from deep seawater.

    Science.gov (United States)

    Wang, Ming-Qing; Sun, Li

    2016-10-01

    In this study, we identified a novel Gram-stain-negative, aerobic, motile, and rod-shaped bacterium, strain KX 20T, isolated from the deep seawater in Okinawa Trough, northwestern Pacific Ocean. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain KX 20T was related to members of the genus Pseudomonas and shares the highest sequence identities with Pseudomonas aestusnigri CECT 8317T (99.4 %) and Pseudomonas pachastrellae JCM 12285T (98.5 %). The 16S rRNA gene sequence identities between strain KX 20T and other members of the genus Pseudomonaswere below 96.6 %. The gyrB and rpoD genes of strain KX 20T shared 82.0 to 89.3 % sequence identity with the gyrB and rpoD genes of the closest phylogenetic neighbours of KX 20T. The predominant cellular fatty acids of strain KX 20T were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) (29.2 %), C16 : 0 (24.5 %), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) (21.5 %) and C12 : 0 (8.2 %). The major polar lipids of strain KX 20T were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and unknown phospholipids. The genomic DNA G+C content of strain KX 20T was 62.9 mol%. On the basis of phylogenetic analysis and phenotypic characteristics, a novel species, Pseudomonas oceani sp. nov. is proposed. The type strain is KX 20T (=CGMCC 1.15195T=DSM 100277T).

  3. Geochemical Processes During Managed Aquifer Recharge With Desalinated Seawater

    Science.gov (United States)

    Ganot, Y.; Holtzman, R.; Weisbrod, N.; Russak, A.; Katz, Y.; Kurtzman, D.

    2018-02-01

    We study geochemical processes along the variably-saturated zone during managed aquifer recharge (MAR) with reverse-osmosis desalinated seawater (DSW). The DSW, post-treated at the desalination plant by calcite dissolution (remineralization) to meet the Israeli water quality standards, is recharged into the Israeli Coastal Aquifer through an infiltration pond. Water quality monitoring during two MAR events using suction cups and wells inside the pond indicates that cation exchange is the dominant subsurface reaction, driven by the high Ca2+ concentration in the post-treated DSW. Stable isotope analysis shows that the shallow groundwater composition is similar to the recharged DSW, except for enrichment of Mg2+, Na+, Ca2+, and HCO3-. A calibrated variably-saturated reactive transport model is used to predict the geochemical evolution during 50 years of MAR for two water quality scenarios: (i) post-treated DSW (current practice) and (ii) soft DSW (lacking the remineralization post-treatment process). The latter scenario was aimed to test soil-aquifer-treatment (SAT) as an alternative post-treatment technique. Both scenarios provide an enrichment of ˜2.5 mg L-1 in Mg2+ due to cation exchange, compared to practically zero Mg2+ currently found in the Israeli DSW. Simulations of the alternative SAT scenario provide Ca2+ and HCO3- remineralization due to calcite dissolution at levels that meet the Israeli standard for DSW. The simulated calcite content reduction in the sediments below the infiltration pond after 50 years of MAR was low (<1%). Our findings suggest that remineralization using SAT for DSW is a potentially sustainable practice at MAR sites overlying calcareous sandy aquifers.

  4. Geochemical processes during managed aquifer recharge with desalinated seawater

    Science.gov (United States)

    Ganot, Y.; Holtzman, R.; Weisbrod, N.; Russak, A.; Katz, Y.; Kurtzman, D.

    2017-12-01

    In this work we study the geochemical processes along the variably-saturated zone during managed aquifer recharge (MAR) with reverse-osmosis desalinated seawater (DSW) to an infiltration pond at the Menashe site, located above the Israeli coastal aquifer. The DSW is post-treated by calcite dissolution (remineralization) in order to meet the Israeli desalinated water quality criteria. Suction cups and monitoring wells inside the pond were used to monitor water quality during two MAR events on 2015 and 2016. Results show that cation exchange is dominant, driven by the high Ca2+ concentration in the post-treated DSW. Stable isotope analysis shows that the composition of the shallow groundwater is similar to the recharged DSW, but with enrichment of Mg2+, Na+, Ca2+ and HCO3-. A calibrated variably-saturated reactive transport model was used to predict the geochemical evolution during 50 years of MAR with two water quality scenarios: post-treated DSW and soft DSW (without post-treatment). The latter scenario was aimed to test soil-aquifer-treatment as an alternative post-treatment technique. In terms of water quality, the results of the two scenarios were found within the range of the desalinated water criteria. Mg2+ enrichment was stable ( 2.5 mg L-1), higher than the zero concentration found in the Israeli DSW. Calcite content reduction was low (<1%) along the variably-saturated profile, after 50 years of MAR. This suggests that using soil-aquifer-treatment as a remineralization technique for DSW is potentially a sustainable practice, which is limited only by the current hydraulic capacity of the Menashe MAR site.

  5. A coastal surface seawater analyzer for nitrogenous nutrient mapping

    Science.gov (United States)

    Masserini, Robert T.; Fanning, Kent A.; Hendrix, Steven A.; Kleiman, Brittany M.

    2017-11-01

    Satellite-data-based modeling of chlorophyll indicates that ocean waters in the mesosphere category are responsible for the majority of oceanic net primary productivity. Coastal waters, which frequently have surface chlorophyll values in the mesosphere range and have strong horizontal chlorophyll gradients and large temporal variations. Thus programs of detailed coastal nutrient surveys are essential to the study of the dynamics of oceanic net primary productivity, along with land use impacts on estuarine and coastal ecosystems. The degree of variability in these regions necessitates flexible instrumentation capable of near real-time analysis to detect and monitor analytes of interest. This work describes the development of a portable coastal surface seawater analyzer for nutrient mapping that can simultaneously elucidate with high resolution the distribution of nitrate, nitrite, and ammonium - the three principal nitrogenous inorganic nutrients in coastal systems. The approach focuses on the use of pulsed xenon flash lamps to construct an analyzer which can be adapted to any automated chemistry with fluorescence detection. The system has two heaters, on-the-fly standardization, on-board data logging, an independent 24 volt direct current power supply, internal local operating network, a 12 channel peristaltic pump, four rotary injection/selection valves, and an intuitive graphical user interface. Using the methodology of Masserini and Fanning (2000) the detection limits for ammonium, nitrite, and nitrate plus nitrite were 11, 10, and 22 nM, respectively. A field test of the analyzer in Gulf of Mexico coastal waters demonstrated its ability to monitor and delineate the complexity of inorganic nitrogen nutrient enrichments within a coastal system.

  6. Kordia antarctica sp. nov., isolated from Antarctic seawater.

    Science.gov (United States)

    Baek, Kiwoon; Choi, Ahyoung; Kang, Ilnam; Lee, Kiyoung; Cho, Jang-Cheon

    2013-10-01

    A Gram-staining-negative, chemoheterotrophic, yellow-pigmented, non-motile, flexirubin-negative, facultatively anaerobic bacterium, designated strain IMCC3317(T), was isolated from a coastal seawater sample from the Antarctic Penninsula. Optimal growth of strain IMCC3317(T) was observed at 20 °C, pH 8.0 and in the presence of 2-3 % NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain IMCC3317(T) belonged to the genus Kordia and was closely related to Kordia algicida OT-1(T) (96.7 % sequence similarity) and Kordia periserrulae IMCC1412(T) (96.1 % sequence similarity). The major fatty acids were 10-methyl C16 : 0 and/or iso-C16 : 1ω9c, iso-C17 : 0 3-OH, iso-C15 : 0 and anteiso-C15 : 0. The G+C content of the genomic DNA was 35.1 mol%. The strain contained menaquinone-6 (MK-6) as the respiratory quinone. The polar lipids detected in the strain were phosphatidylethanolamine and unknown aminophospholipids, aminolipids and polar lipids. On the basis of phylogenetic distinction and differential phenotypic characteristics, it is suggested that strain IMCC3317(T) ( = KCTC 32292(T) = NBRC 109401(T)) be assigned to the genus Kordia as the type strain of a novel species, for which the name Kordia antarctica sp. nov. is proposed.

  7. Nucleation of metastable aragonite CaCO3 in seawater.

    Science.gov (United States)

    Sun, Wenhao; Jayaraman, Saivenkataraman; Chen, Wei; Persson, Kristin A; Ceder, Gerbrand

    2015-03-17

    Predicting the conditions in which a compound adopts a metastable structure when it crystallizes out of solution is an unsolved and fundamental problem in materials synthesis, and one which, if understood and harnessed, could enable the rational design of synthesis pathways toward or away from metastable structures. Crystallization of metastable phases is particularly accessible via low-temperature solution-based routes, such as chimie douce and hydrothermal synthesis, but although the chemistry of the solution plays a crucial role in governing which polymorph forms, how it does so is poorly understood. Here, we demonstrate an ab initio technique to quantify thermodynamic parameters of surfaces and bulks in equilibrium with an aqueous environment, enabling the calculation of nucleation barriers of competing polymorphs as a function of solution chemistry, thereby predicting the solution conditions governing polymorph selection. We apply this approach to resolve the long-standing "calcite-aragonite problem"--the observation that calcium carbonate precipitates as the metastable aragonite polymorph in marine environments, rather than the stable phase calcite--which is of tremendous relevance to biomineralization, carbon sequestration, paleogeochemistry, and the vulnerability of marine life to ocean acidification. We identify a direct relationship between the calcite surface energy and solution Mg:Ca [corrected] ion concentrations, showing that the calcite nucleation barrier surpasses that of metastable aragonite in solutions with Mg:Ca ratios consistent with modern seawater, allowing aragonite to dominate the kinetics of nucleation. Our ability to quantify how solution parameters distinguish between polymorphs marks an important step toward the ab initio prediction of materials synthesis pathways in solution.

  8. Umboniibacter roseus sp. nov., isolated from coastal seawater.

    Science.gov (United States)

    Sung, Hye-Ri; Kim, Mibang; Shin, Kee-Sun

    2015-11-01

    A Gram-reaction-negative, non-motile, strictly aerobic, dark pink-pigmented and rod-shaped bacterial isolate, designated 14-121-B13T, was isolated from surface seawater off the coast of the South Sea at Namhae-gun, Republic of Korea. Cells were catalase- and oxidase-positive and required NaCl for growth. Strain 14-121-B13T grew optimally at 30 °C, in the presence of 2 % (w/v) NaCl and at pH 7.5-8.0.Neighbour-joining, maximum-likelihood and maximum-parsimony phylogenetic trees based on 16S rRNA gene sequences showed that strain 14-121-B13T clustered with the type strain of Umboniibacter marinipuniceus, with which it exhibited 96.7 % sequence similarity. The DNA G+C content of strain 14-121-B13T was 48.9 mol%. The major cellular fatty acids were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. The major respiratory quinone was ubiquinone Q-7 and the polar lipids detected in strain 14-121-B13T were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, an unidentified aminolipid, unidentified phospholipids, unidentified aminophospholipids and unidentified lipids. Based on the phenotypic, chemotaxonomic and phylogenetic data presented, strain 14-121-B13T is considered to represent a novel species of the genus, Umboniibacter for which the name Umboniibacter roseus sp. nov. is proposed. The type strain is 14-121-B13T ( = DSM 29882T = KCTC 42467T).

  9. Forward osmosis niches in seawater desalination and wastewater reuse

    KAUST Repository

    Valladares Linares, Rodrigo

    2014-12-01

    This review focuses on the present status of forward osmosis (FO) niches in two main areas: seawater desalination and wastewater reuse. Specific applications for desalination and impaired-quality water treatment and reuse are described, as well as the benefits, advantages, challenges, costs and knowledge gaps on FO hybrid systems are discussed. FO can play a role as a bridge to integrate upstream and downstream water treatment processes, to reduce the energy consumption of the entire desalination or water recovery and reuse processes, thus achieving a sustainable solution for the water-energy nexus. FO hybrid membrane systems showed to have advantages over traditional membrane process like high pressure reverse osmosis and nanofiltration for desalination and wastewater treatment: (i) chemical storage and feed water systems may be reduced for capital, operational and maintenance cost, (ii) water quality is improved, (iii) reduced process piping costs, (iv) more flexible treatment units, and (v) higher overall sustainability of the desalination and wastewater treatment process. Nevertheless, major challenges make FO systems not yet a commercially viable technology, the most critical being the development of a high flux membrane, capable of maintaining an elevated salt rejection and a reduced internal concentration polarization effect, and the availability of appropriate draw solutions (cost effective and non-toxic), which can be recirculated via an efficient recovery process. This review article highlights the features of hybrid FO systems and specifically provides the state-of-the-art applications in the water industry in a novel classification and based on the latest developments toward scaling up these systems.

  10. An optical fiber expendable seawater temperature/depth profile sensor

    Science.gov (United States)

    Zhao, Qiang; Chen, Shizhe; Zhang, Keke; Yan, Xingkui; Yang, Xianglong; Bai, Xuejiao; Liu, Shixuan

    2017-10-01

    Marine expendable temperature/depth profiler (XBT) is a disposable measuring instrument which can obtain temperature/depth profile data quickly in large area waters and mainly used for marine surveys, scientific research, military application. The temperature measuring device is a thermistor in the conventional XBT probe (CXBT)and the depth data is only a calculated value by speed and time depth calculation formula which is not an accurate measurement result. Firstly, an optical fiber expendable temperature/depth sensor based on the FBG-LPG cascaded structure is proposed to solve the problems of the CXBT, namely the use of LPG and FBG were used to detect the water temperature and depth, respectively. Secondly, the fiber end reflective mirror is used to simplify optical cascade structure and optimize the system performance. Finally, the optical path is designed and optimized using the reflective optical fiber end mirror. The experimental results show that the sensitivity of temperature and depth sensing based on FBG-LPG cascade structure is about 0.0030C and 0.1%F.S. respectively, which can meet the requirements of the sea water temperature/depth observation. The reflectivity of reflection mirror is in the range from 48.8% to 72.5%, the resonant peak of FBG and LPG are reasonable and the whole spectrum are suitable for demodulation. Through research on the optical fiber XBT (FXBT), the direct measurement of deep-sea temperature/depth profile data can be obtained simultaneously, quickly and accurately. The FXBT is a new all-optical seawater temperature/depth sensor, which has important academic value and broad application prospect and is expected to replace the CXBT in the future.

  11. Development of sorbers for the recovery of uranium from seawater. Part 2. The accumulation of uranium from seawater by resins containing amidoxime and imidoxime functional groups

    International Nuclear Information System (INIS)

    Astheimer, L.; Schenk, H.J.; Witte, E.G.; Schwochau, K.

    1983-01-01

    Hydroxylamine derivatives of cross-linked poly(acrylonitriles), so-called poly(acrylamidoxime) resins, are suitable for the accumulation of uranium from natural seawater of pH = 8.1 to 8.3. Depending on the method of manufacture, these sorbers yield excellent uranium loadings up to some thousand ppM which roughly equals the average uranium content of actually explored uranium ores. The rate of uranium uptake, which is 5 to 30 ppM/d at room temperature, increases with increasing temperature of seawater. Uranium can be eluted by 1 M HCl with an elution efficiency of more than 90%. Owing to a certain instability of the uranium binding groups in acid eluants, the uranium uptake decreases with increasing number of sorption-elution cycles. Hydroxylamine derivatives of poly(acrylonitrile) are shown to contain simultaneously at least two kinds of functional groups: open-chain amidoxime groups which are stable and cyclic imidoxime groups which are unstable in 1 M HCl. Experimental evidence is presented that the uptake of uranium from natural seawater is closely related to the presence of cyclic imidoxime configurations in the polyacrylic lattice. Polystyrene and poly(glycidylmethacrylate)-based amidoxime and imide dioxime resins are less effective in extracting uranium from natural seawater. 10 figures, 4 tables

  12. Seawater-sediment interaction at elevated temperatures and pressures: implications for the near field chemical environment

    International Nuclear Information System (INIS)

    Seyfried, W.E. Jr.; Thornton, E.C.; Janecky, D.R.

    1981-01-01

    Results of four experiments are reported which document chemical exchange and mineralogic modification during seawater-sediment interaction at 200 0 to 300 0 C, 500 bars. Sediments used for this study are from MPG-1 (central North Pacific). Experimental conditions (T, P, W/R) were chosen to be reasonably analogous to conditions which will characterize the near field environment; that is a zone within approximately 1 m of the buried waste canister. In general, the major element chemistry of seawater was similarly modified in all experiments. The aqueous concentrations of Ca, Mg, Sr, and SO 4 decreased and SiO 2 /sub (aq)/, Na, K, and ΣCO 2 increased relative to values in seawater prior to reaction with sediments. pH decreased and remained distinctly acid. Con comitantly significant concentrations of heavy metals entered seawater from the sediments during reaction. Dissolution of Mn-rich phases profoundly affected alteration processes. For example, reaction of MnO 2 components of the smectite-rich sediment (Pacific smectite) with seawater created an unusually oxidizing milieu (fO 2 = 10 -7 74 ), and resulted in dissolution of significant quantities of Au from the reaction cell. Although illite-quartz-Fe-chlorite (sediment B)-seawater interaction also created a relatively oxidizing environment, this environment was not capable of oxidizing Au. Thus, in this regard (oxidation potential) sediment mineralogy exerts a strong influence. Mineralogic modification of sediment B at 200 0 and 300 0 C was minor and characterized by partial dissolution of illite and exchange of Fe for Mg in chlorite. In contrast the smectite-rich sediment, which, prior to reaction with seawater contained a poorly crystalline smectite phase, clinoptilolite, and amorphous material, recrystallized totally to a well defined smectite mineral. Anhydrite was abundantly present amongst the alteration products of all experiments

  13. Variable response of three Trifolium repens ecotypes to soil flooding by seawater.

    Science.gov (United States)

    White, Anissia C; Colmer, Timothy D; Cawthray, Greg R; Hanley, Mick E

    2014-08-01

    Despite concerns about the impact of rising sea levels and storm surge events on coastal ecosystems, there is remarkably little information on the response of terrestrial coastal plant species to seawater inundation. The aim of this study was to elucidate responses of a glycophyte (white clover, Trifolium repens) to short-duration soil flooding by seawater and recovery following leaching of salts. Using plants cultivated from parent ecotypes collected from a natural soil salinity gradient, the impact of short-duration seawater soil flooding (8 or 24 h) on short-term changes in leaf salt ion and organic solute concentrations was examined, together with longer term impacts on plant growth (stolon elongation) and flowering. There was substantial Cl(-) and Na(+) accumulation in leaves, especially for plants subjected to 24 h soil flooding with seawater, but no consistent variation linked to parent plant provenance. Proline and sucrose concentrations also increased in plants following seawater flooding of the soil. Plant growth and flowering were reduced by longer soil immersion times (seawater flooding followed by drainage and freshwater inputs), but plants originating from more saline soil responded less negatively than those from lower salinity soil. The accumulation of proline and sucrose indicates a potential for solute accumulation as a response to the osmotic imbalance caused by salt ions, while variation in growth and flowering responses between ecotypes points to a natural adaptive capacity for tolerance of short-duration seawater soil flooding in T. repens. Consequently, it is suggested that selection for tolerant ecotypes is possible should the predicted increase in frequency of storm surge flooding events occur. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Activation of TRPV1-dependent calcium oscillation exacerbates seawater inhalation-induced acute lung injury.

    Science.gov (United States)

    Li, Congcong; Bo, Liyan; Liu, Qingqing; Liu, Wei; Chen, Xiangjun; Xu, Dunquan; Jin, Faguang

    2016-03-01

    Calcium is an important second messenger and it is widely recognized that acute lung injury (ALI) is often caused by oscillations of cytosolic free Ca2+. Previous studies have indicated that the activation of transient receptor potential‑vanilloid (TRPV) channels and subsequent Ca2+ entry initiates an acute calcium‑dependent permeability increase during ALI. However, whether seawater exposure induces such an effect through the activation of TRPV channels remains unknown. In the current study, the effect of calcium, a component of seawater, on the inflammatory reactions that occur during seawater drowning‑induced ALI, was examined. The results demonstrated that a high concentration of calcium ions in seawater increased lung tissue myeloperoxidase activity and the secretion of inflammatory mediators, such as tumor necrosis factor‑α (TNF‑α) and interleukin (IL)‑1β and IL‑6. Further study demonstrated that the seawater challenge elevated cytosolic Ca2+ concentration, indicated by [Ca2+]c, by inducing calcium influx from the extracellular medium via TRPV1 channels. The elevated [Ca2+c] may have resulted in the increased release of TNF‑α and IL‑1β via increased phosphorylation of nuclear factor‑κB (NF‑κB). It was concluded that a high concentration of calcium in seawater exacerbated lung injury, and TRPV1 channels were notable mediators of the calcium increase initiated by the seawater challenge. Calcium influx through TRPV1 may have led to greater phosphorylation of NF‑κB and increased release of TNF‑α and IL‑1β.

  15. Microbial ureolysis in the seawater-catalysed urine phosphorus recovery system: Kinetic study and reactor verification.

    Science.gov (United States)

    Tang, Wen-Tao; Dai, Ji; Liu, Rulong; Chen, Guang-Hao

    2015-12-15

    Our previous study has confirmed the feasibility of using seawater as an economical precipitant for urine phosphorus (P) precipitation. However, we still understand very little about the ureolysis in the Seawater-based Urine Phosphorus Recovery (SUPR) system despite its being a crucial step for urine P recovery. In this study, batch experiments were conducted to investigate the kinetics of microbial ureolysis in the seawater-urine system. Indigenous bacteria from urine and seawater exhibited relatively low ureolytic activity, but they adapted quickly to the urine-seawater mixture during batch cultivation. During cultivation, both the abundance and specific ureolysis rate of the indigenous bacteria were greatly enhanced as confirmed by a biomass-dependent Michaelis-Menten model. The period for fully ureolysis was decreased from 180 h to 2.5 h after four cycles of cultivation. Based on the successful cultivation, a lab-scale SUPR reactor was set up to verify the fast ureolysis and efficient P recovery in the SUPR system. Nearly complete urine P removal was achieved in the reactor in 6 h without adding any chemicals. Terminal Restriction Fragment Length Polymorphism (TRFLP) analysis revealed that the predominant groups of bacteria in the SUPR reactor likely originated from seawater rather than urine. Moreover, batch tests confirmed the high ureolysis rates and high phosphorus removal efficiency induced by cultivated bacteria in the SUPR reactor under seawater-to-urine mixing ratios ranging from 1:1 to 9:1. This study has proved that the enrichment of indigenous bacteria in the SUPR system can lead to sufficient ureolytic activity for phosphate precipitation, thus providing an efficient and economical method for urine P recovery. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Cell Culture Isolation of Piscine Nodavirus (Betanodavirus) in Fish-Rearing Seawater.

    Science.gov (United States)

    Nishi, Shinnosuke; Yamashita, Hirofumi; Kawato, Yasuhiko; Nakai, Toshihiro

    2016-04-01

    Piscine nodavirus (betanodavirus) is the causative agent of viral nervous necrosis (VNN) in a variety of cultured fish species, particularly marine fish. In the present study, we developed a sensitive method for cell culture isolation of the virus from seawater and applied the method to a spontaneous fish-rearing environment. The virus in seawater was concentrated by an iron-based flocculation method and subjected to isolation with E-11 cells. A real-time reverse transcriptase PCR (RT-PCR) assay was used to quantify the virus in water. After spiking into seawater was performed, a betanodavirus strain (red spotted grouper nervous necrosis virus [RGNNV] genotype) was effectively recovered in the E-11 cells at a detection limit of approximately 10(5)copies (equivalent to 10(2)50% tissue culture infective doses [TCID50])/liter seawater. In an experimental infection of juvenile sevenband grouper (Epinephelus septemfasciatus) with the virus, the virus was isolated from the drainage of a fish-rearing tank when the virus level in water was at least approximately 10(5)copies/liter. The application of this method to seven band grouper-rearing floating net pens, where VNN prevailed, resulted in the successful isolation of the virus from seawater. No differences were found in the partial sequences of the coat protein gene (RNA2) between the clinical virus isolates of dead fish and the cell-cultured virus isolates from seawater, and the viruses were identified as RGNNV. The infection experiment showed that the virus isolates from seawater were virulent to seven band grouper. These results showed direct evidence of the horizontal transmission of betanodavirus via rearing water in marine aquaculture. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  17. Corrosion studies of a chromium steel in imitated seawater

    International Nuclear Information System (INIS)

    Lakatos-Varsanyi, M.; Meisel, W.

    2002-01-01

    A series of in-door experiments was performed to get some insight into the corrosion behavior of a commercial alloy Fe-12% Cr (3CR12) exposed to imitated seawater. Applying different analytical methods, the main corrosion process was found to be the formation of flakes on the surface which, peel off after they have reached a certain size. Some Cr is dissolved in the solution, its relative concentration with respect to Fe is higher than in the bulk material. The flakes consist mainly of mixed oxihydroxides of the type FeOOH containing some Cr and Mg. The oxidic layer on the interface is very thin, behaves essentially stationary with a slight growth of about 0.05 nm/day. It consists of Cr oxide with some inclusions of Fe and Mg and is not of a chromite type. Immediately below this oxidic layer, the metallic substrate exhibits a thin layer depleted in Cr and behaving like α-Fe (bcc). As compared with stainless steel, potentiostatic current vs. time records at anodic potentials below the pitting potential indicate a very different stability of the surface films for 3CR12. The kinetics of the passive layer formation on 3CR12 was found to follow a parabolic law initially and to change later (after 10...100 seconds in deaerated solution and even earlier in aerated solution) to a linear law. After some time, pitting corrosion and/or cracks due to internal stresses play the dominant role. Cr does not form a protective oxidic layer. The surface morphology of samples exposed at -200 mV for 20 and 80 minutes has been studied by scanning electron microscopy and scanning Auger microprobe. The results reflect the competing formation of oxidic layers and pitting, the participation of Cr in the dissolution process. It is also suggested that Mg, which is a component of the solution was incorporated into the rust and some Mg was also found on the metallic surface. (author)

  18. Sea-level rise impacts on seawater intrusion in coastal aquifers: Review and integration

    Science.gov (United States)

    Ketabchi, Hamed; Mahmoodzadeh, Davood; Ataie-Ashtiani, Behzad; Simmons, Craig T.

    2016-04-01

    Sea-level rise (SLR) influences groundwater hydraulics and in particular seawater intrusion (SWI) in many coastal aquifers. The quantification of the combined and relative impacts of influential factors on SWI has not previously been considered in coastal aquifers. In the present study, a systematic review of the available literature on this topic is first provided. Then, the potential remaining challenges are scrutinized. Open questions on the effects of more realistic complexities such as gradual SLR, parameter uncertainties, and the associated influences in decision-making models are issues requiring further investigation. We assess and quantify the seawater toe location under the impacts of SLR in combination with recharge rate variations, land-surface inundation (LSI) due to SLR, aquifer bed slope variation, and changing landward boundary conditions (LWBCs). This is the first study to include all of these factors in a single analysis framework. Both analytical and numerical models are used for these sensitivity assessments. It is demonstrated that (1) LSI caused by SLR has a significant incremental impact on the seawater toe location, especially in the flatter coasts and the flux-controlled (FC) LWBCs, however this impact is less than the reported orders of magnitude differences which were estimated using only analytical solutions; (2) LWBCs significantly influence the SLR impacts under almost all conditions considered in this study; (3) The main controlling factors of seawater toe location are the magnitudes of fresh groundwater discharge to sea and recharge rate. Regional freshwater flux entering from the landward boundary and the groundwater hydraulic gradient are the major contributors of fresh groundwater discharge to sea for both FC and head-controlled (HC) systems, respectively; (4) A larger response of the aquifer and larger seawater toe location changes are demonstrable for a larger ratio of the aquifer thickness to the aquifer length particularly in

  19. Investigations into the Reusability of Amidoxime-Based Polymeric Adsorbents for Seawater Uranium Extraction

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, Li-Jung [Marine; Pan, Horng-Bin [Department; Wai, Chien M. [Department; Byers, Margaret F. [Nuclear; Schneider, Erich [Nuclear; Strivens, Jonathan E. [Marine; Janke, Christopher J. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831, United States; Das, Sadananda [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831, United States; Mayes, Richard T. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831, United States; Wood, Jordana R. [Marine; Schlafer, Nicholas [Marine; Gill, Gary A. [Marine

    2017-09-29

    The ability to re-use amidoxime-based polymeric adsorbents is a critical component in reducing the overall cost of the technology to extract uranium from seawater. This report describes an evaluation of adsorbent reusability in multiple re-use (adsorption/stripping) cycles in real seawater exposures with potassium bicarbonate (KHCO3) elution using several amidoxime-based polymeric adsorbents. The KHCO3 elution technique achieved ~100% recovery of uranium adsorption capacity in the first re-use. Subsequent re-uses showed significant drops in adsorption capacity. After the 4th re-use with the ORNL AI8 adsorbent, the 56-day adsorption capacity dropped to 28% of its original capacity. FTIR spectra revealed that there was a conversion of the amidoxime ligands to carboxylate groups during extended seawater exposure, becoming more significant with longer the exposure time. Ca and Mg adsorption capacities also increased with each re-use cycle supporting the hypothesis that long term exposure resulted in converting amidoxime to carboxylate, enhancing the adsorption of Ca and Mg. Shorter seawater exposure (adsorption/stripping) cycles (28 vs. 42 days) had higher adsorption capacities after re-use, but the shorter exposure cycle time did not produce an overall better performance in terms of cumulative exposure time. Recovery of uranium capacity in re-uses may also vary across different adsorbent formulations. Through multiple re-use the adsorbent AI8 can harvest 10 g uranium/kg adsorbent in ~140 days, using a 28-day adsorption/stripping cycle, a performance much better than would be achieved with a single use of the adsorbent through very long-term exposure (saturation capacity = 7.4 g U/kg adsorbent). A time dependent seawater exposure model to evaluate the cost associated with reusing amidoxime-based adsorbents in real seawater exposures was developed. The cost to extract uranium from seawater ranged from $610-830/kg U was predicted. Model simulation suggests that a short

  20. Measurement of the Dielectric Constant of Seawater at L-Band: Techniques and Measurements

    Science.gov (United States)

    Lang, R.; Utku, C.; Tarkocin, Y.; LeVine, D.

    2009-01-01

    Satellite instruments, that will monitor salinity from space in the near future, require an accurate relationship between salinity/temperature and seawater dielectric constant. This paper will review measurements that were made of the dielectric constant of seawater during the past several years. The objective of the measurements is to determine the dependence of the dielectric constant of seawater on salinity and on temperature, more accurately than in the past. by taking advantage of modem instrumentation. The measurements of seawater permittivity have been performed as a function of salinity and temperature using a transmission resonant cavity technique. The measurements have been made in the salinity range of 10 to 38 psu and in the temperature range of IOU C to 35 C. These results will be useful in algorithm development for sensor systems such as SMOS and Aquarius. The measurement system consists of a brass microwave cavity that is resonant at 1.413 GHz. The seawater is introduced into the cavity through a capillary glass tube having an inner diameter of 0.1 mm. The diameter of the tube has been made very small so that the amount of seawater introduced in the cavity is small - thus maintaining the sensitivity of the measurements and allowing the use of perturbation theory predicting the seawater permittivity. The change in resonant frequency and the change in cavity Q can be used to determine the real and imaginary pare of the dielectric constant of seawater introduced into the slender tube. The microwave measurements are made by an HPS722D network analyzer. The cavity has been immersed in a uateriethylene-glycol bath which is connected to a Lauda circulator. The circulator keeps the brass cavity at a temperature constant to within 0.01 degrees. The system is automated using a Visual Basic program to control the analyzer and to collect the data. The results of the dielectric constant measurements of seawater will be presented. The measurement results will be

  1. Effects of seawater components on radiolysis of water at elevated temperature

    International Nuclear Information System (INIS)

    Wada, Yoichi; Tachibana, Masahiko; Ishida, Kazushige; Ota, Nobuyuki; Shigenaka, Naoto; Inagaki, Hiromitsu; Noda, Hiroshi

    2014-01-01

    Effects of seawater components on radiolysis of water at elevated temperature have been studied with a radiolysis model in order to evaluate influence on integrity of materials used in an ABWR. In 2011, seawater flowed into a wide part of the nuclear power plant system of the Hamaoka Nuclear Power Station Reactor No. 5 owned by Chubu Electric Power Co., Inc. after condenser tubes broke during the plant shutdown operation. The reactor water temperature was 250°C and its maximum Cl − concentration was ca. 450 ppm when seawater was mixed with reactor water. In order to clarify effects of the sea water components on radiolysis of water at elevated temperature, a radiolysis model calculation was conducted with Hitachi's radiolysis analysis code 'SIMFONY'. For the calculation, the temperature range was set from 50 to 250°C with 50°C increments and the gamma dose rate was set at 60 Gys −1 to see the effect of gamma irradiation from fuels under shutdown conditions. Concentrations of radiolytic species were calculated for 10 5 s. Dilution ratio of seawater was changed to see the effects of concentration of seawater components. Reaction rate constants of the Cl − , Br − , HCO 3 − , and SO 4 2− systems were considered. The main radiolytic species were predicted to be hydrogen and oxygen. Hydrogen peroxide of low concentration was produced in seawater-mixed water at elevated temperatures. Compared with these main products, concentrations of radiolytic products originating from chloride ion and other seawater components were found to be rather low. The dominant product among them was ClO 3 − and its concentration was found to be below 0.01ppm at 10 5 s. Then, during the plant shutdown operation, the harmful influence from radiolytic species originating from seawater components on integrity of fuel materials must be smaller than that of chloride ion which is the main ionic species in seawater. (author)

  2. Biodegradation of n-alkanes on oil-seawater interfaces at different temperatures and microbial communities associated with the degradation.

    Science.gov (United States)

    Lofthus, Synnøve; Netzer, Roman; Lewin, Anna S; Heggeset, Tonje M B; Haugen, Tone; Brakstad, Odd Gunnar

    2018-04-01

    Oil biodegradation studies have mainly focused on microbial processes in dispersions, not specifically on the interfaces between the oil and the seawater in the dispersions. In this study, a hydrophobic adsorbent system, consisting of Fluortex fabrics, was used to investigate biodegradation of n-alkanes and microbial communities on oil-seawater interfaces in natural non-amended seawater. The study was performed over a temperature range from 0 to 20 °C, to determine how temperature affected biodegradation at the oil-seawater interfaces. Biodegradation of n-alkanes were influenced both by seawater temperature and chain-length. Biotransformation rates of n-alkanes decreased by reduced seawater temperature. Low rate coefficients at a seawater temperature of 0 °C were probably associated with changes in physical-chemical properties of alkanes. The primary bacterial colonization of the interfaces was predominated by the family Oceanospirillaceae at all temperatures, demonstrating the wide temperature range of these hydrocarbonoclastic bacteria. The mesophilic genus Oleibacter was predominant at the seawater temperature of 20 °C, and the psychrophilic genus Oleispira at 5 and 0 °C. Upon completion of n-alkane biotransformation, other oil-degrading and heterotrophic bacteria became abundant, including Piscirickettsiaceae (Cycloclasticus), Colwelliaceae (Colwellia), Altermonadaceae (Altermonas), and Rhodobacteraceae. This is one of a few studies that describe the biodegradation of oil, and the microbial communities associated with the degradation, directly at the oil-seawater interfaces over a large temperature interval.

  3. Numerical modeling of seawater intrusion in Zhoushuizi district of Dalian City, China

    Science.gov (United States)

    Zhao, J.; Lin, J.; Wu, J.

    2013-12-01

    A three-dimensional heterogeneous density-dependent numerical model was constructed to simulate the seawater intrusion process in coastal aquifers in Zhoushuizi Region, Dalian City. Model calibration was achieved through a prediction-correction method by adjusting the zonation and values of hydrogeologic parameters until the calculated heads and concentrations matched the observed values. Model validation results also showed that it was reasonable under current data conditions. Then the calibrated and validated model was applied to predict the dynamics and trend of seawater intrusion according to the current groundwater abstraction conditions in this study area 30 years after 2010. Prediction results showed that overall seawater intrusion in the future would be even more severe. Actually, with the growing of the population and development of the economy, the demand for ground water will be increasing continuously so that the problem of seawater intrusion may be more serious than that predicted by the modelin this study. Better strategies for reasonably governing exploitation of groundwater in the study area can be further developed by using this three-dimensional seawater intrusion model.

  4. Concentration of 99Tc in seawater by coprecipitation with iron hydroxide

    International Nuclear Information System (INIS)

    Momoshima, Noriyuki; Eto, Ichiro; Muhammad Sayad; Takashima, Yoshimasa

    1991-01-01

    A method for accumulation of 99 Tc in seawater has been developed. Technetium tracer in +VII oxidation state was added to the seawater together with reducing agent, potassium pyrosulfite, and coprecipitation agent, ferric chloride. After reduction of Tc(VII) at pH 4, Tc(IV) was coprecipitated as iron hydroxide by addition of sodium hydroxide to pH 9. The reduction and coprecipitation was quantitative and overall recovery of Tc was more than 98%. The green color of iron precipitate formed at pH 9 suggested that Tc(VII) as well as ferric ion was reduced under this condition. Adsorption of Tc(IV), however, was poor for iron hydroxide which was prepared in advance indicating active surface of freshly precipitated iron hydroxide is necessary for quantitative recovery of Tc(IV). A repeating coprecipitation technique was examined for enrichment of Tc in seawater that the same iron was used repeatedly as coprecipitater. After separation of iron hydroxide with Tc(IV) from supernatant, the precipitate was dissolved by addition of acid and then new seawater which contained reducing agent and Tc(VII) was added. Reduction and coprecipitation was again carried out. Good recovery was attained for 7 repeats. The proposed repeating coprecipitation technique was applicable to a large amount of seawater without increasing the amount of iron hydroxide which is subjected to radiochemical analysis. (author)

  5. Nitrogen fate in a subtropical mangrove swamp: Potential association with seawater-groundwater exchange.

    Science.gov (United States)

    Xiao, Kai; Wu, Jiapeng; Li, Hailong; Hong, Yiguo; Wilson, Alicia M; Jiao, Jiu Jimmy; Shananan, Meghan

    2018-04-18

    Coastal mangrove swamps play an important role in nutrient cycling at the land-ocean boundary. However, little is known about the role of periodic seawater-groundwater exchange in the nitrogen cycling processes. Seawater-groundwater exchange rates and inorganic nitrogen concentrations were investigated along a shore-perpendicular intertidal transect in Daya Bay, China. The intertidal transect comprises three hydrologic subzones (tidal creek, mangrove and bare mudflat zones), each with different physicochemical characteristics. Salinity and hydraulic head measurements taken along the transect were used to estimate the exchange rates between seawater and groundwater over a spring-neap tidal cycle. Results showed that the maximum seawater-groundwater exchange occurred within the tidal creek zone, which facilitated high-oxygen seawater infiltration and subsequent nitrification. In contrast, the lowest exchange rate found in the mangrove zone caused over-loading of organic matter and longer groundwater residence times. This created an anoxic environment conducive to nitrogen loss through the anammox and denitrification processes. Potential oxidation rates of ammonia and nitrite were measured by the rapid and high-throughput method and rates of denitrification and anammox were measured by the modified membrane inlet mass spectrometry (MIMS) with isotope pairing, respectively. In the whole transect, denitrification accounted for 90% of the total nitrogen loss, and anammox accounted for the remaining 10%. The average nitrogen removal rate was about 2.07g per day per cubic meter of mangrove sediments. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Degradation of Organic UV filters in Chlorinated Seawater Swimming Pools: Transformation Pathways and Bromoform Formation.

    Science.gov (United States)

    Manasfi, Tarek; Coulomb, Bruno; Ravier, Sylvain; Boudenne, Jean-Luc

    2017-12-05

    Organic ultraviolet (UV) filters are used in sunscreens and other personal-care products to protect against harmful effects of exposure to UV solar radiation. Little is known about the fate of UV filters in seawater swimming pools disinfected with chlorine. The present study investigated the occurrence and fate of five commonly used organic UV filters, namely dioxybenzone, oxybenzone, avobenzone, 2-ethylhexyl-4-methoxycinnamate, and octocrylene, in chlorinated seawater swimming pools. Pool samples were collected to monitor the variation of UV filter concentrations during pool opening hours. Furthermore, laboratory-controlled chlorination experiments were conducted in seawater spiked with UV filters to investigate the reactivity of UV filters. Extracts of chlorination reaction samples were analyzed using high-resolution mass spectrometry and electron-capture detection to identify the potentially formed byproducts. In the collected pool samples, all the UV filters except dioxybenzone were detected. Chlorination reactions showed that only octocrylene was stable in chlorinated seawater. The four reactive UV filters generated brominated transformation products and disinfection byproducts. This formation of brominated products resulted from reactions between the reactive UV filters and bromine, which is formed rapidly when chlorine is added to seawater. Based on the identified byproducts, the transformation pathways of the reactive UV filters were proposed for the first time. Bromoform was generated by all the reactive UV filters at different yields. Bromal hydrate was also detected as one of the byproducts generated by oxybenzone and dioxybenzone.

  7. A study of marine pollution caused by the release of metals into seawater following acid spills.

    Science.gov (United States)

    Cabon, Jean-Yves; Giamarchi, Philippe; Le Floch, Stephane

    2010-07-01

    This study examined the potential metal pollution induced by the accidental spill of different acids into seawater. The acids sink to the bottom according to their densities and subsequently react with marine sediments. The acids selected for this study were acetic, hydrochloric, nitric, sulfuric, and phosphoric acids; the metallic elements selected were Cr, Cu, Fe, Mn, Pb and Zn. The sediment was collected in Brest Harbour. The percentages of metals released from this sediment in the presence of various concentrations of acids in seawater were important; concentrations of approximately 7 mg L(-1) for Mn and 60 mg L(-1) for Zn were observed under our experimental conditions. We also examined the rate of release of these metals from the sediment into the seawater in the presence of the different acids and under different experimental conditions. We found that most of the metallic elements were released from the sediments into the seawater during the first fifteen minutes of exposure. After this time, a high degree of pollution was induced if acids leached into seawater were not rapidly diluted. Copyright 2010 Elsevier Ltd. All rights reserved.

  8. Stabilization of arsenic and lead by magnesium oxide (MgO) in different seawater concentrations.

    Science.gov (United States)

    Kameda, Kentaro; Hashimoto, Yohey; Ok, Yong Sik

    2018-02-01

    Ongoing sea level rise will have a major impact on mobility and migration of contaminants by changing a number of natural phenomena that alter geochemistry and hydrology of subsurface environment. In-situ immobilization techniques may be a promising remediation strategy for mitigating contaminant mobility induced by sea level rise. This study investigated the reaction mechanisms of magnesium oxide (MgO) with aqueous Pb and As under freshwater and seawater using XAFS spectroscopy. Initial concentrations of Pb and As in freshwater strongly controlled the characteristics of the reaction product of MgO. Our study revealed that i) the removal of aqueous Pb and As by MgO was increased by the elevation of seawater concentration, and ii) the removal of As was attributed primarily to (inner-sphere) surface adsorption on MgO, independent on seawater concentrations, and iii) the retention mechanism of Pb was dependent on seawater concentrations where formations of Pb oxides and adsorption on the MgO surface were predominant in solutions with low and high salinity, respectively. The release of As fixed with MgO significantly increased in seawater compared to freshwater, although the amount of As desorbed accounted for <0.2% of total As. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Construction of the seawater 87Sr/86Sr curve for the Cenozoic and Cretaceous: supporting data

    International Nuclear Information System (INIS)

    Koepnick, R.B.; Burke, W.H.; Denison, R.E.; Hetherington, E.A.; Nelson, H.F.; Otto, J.B.; Waite, L.E.

    1985-01-01

    We present the data used to construct the Cenozoic and Cretaceous portion of the Phanerozoic curve of seawater 87 Sr/ 86 Sr that had been given in summary form by W.H. Burke and coworkers. All Cenozoic samples (128) and 22 Cretaceous samples are foram-nannofossil oozes and limestones from DSDP cores distributed among 13 sites in the Atlantic, Pacific and Indian Oceans, and the Caribbean Sea. Non-DSDP Cretaceous samples (126) include limestone, anhydrite and phosphate samples from North America, Europe and Asia. Determination of the 87 Sr/ 86 Sr value of seawater at particular times in the past is based on comparison of ratios derived from coeval marine samples from widely separated geographic areas. The general configuration of the Cenozoic and Cretaceous curve appears to be strongly influenced by the history of plate interactions and sea-floor spreading. Specific rises and falls in the 87 Sr/ 86 Sr of seawater, however, may be caused by a variety of factors such as variation in lithologic composition of the crust exposed to weathering, configuration and topographic relief of continents, volcanic activity, rate of sea-floor spreading, extent of continental inundation by epeiric seas, and variations in both climate and paleo-oceanographic conditions. Many or all of these factors are probably related to global tectonic processes, yet their combined effect on the temporal variation of seawater 87 Sr/ 86 Sr can complicate a direct plate-tectonic interpretation for portions of the seawater curve. (Auth.)

  10. Caldera unrest detected with seawater temperature anomalies at Deception Island, Antarctic Peninsula

    Science.gov (United States)

    Berrocoso, M.; Prates, G.; Fernández-Ros, A.; Peci, L. M.; de Gil, A.; Rosado, B.; Páez, R.; Jigena, B.

    2018-04-01

    Increased thermal activity was detected to coincide with the onset of volcano inflation in the seawater-filled caldera at Deception Island. This thermal activity was manifested in pulses of high water temperature that coincided with ocean tide cycles. The seawater temperature anomalies were detected by a thermometric sensor attached to the tide gauge (bottom pressure sensor). This was installed where the seawater circulation and the locations of known thermal anomalies, fumaroles and thermal springs, together favor the detection of water warmed within the caldera. Detection of the increased thermal activity was also possible because sea ice, which covers the entire caldera during the austral winter months, insulates the water and thus reduces temperature exchange between seawater and atmosphere. In these conditions, the water temperature data has been shown to provide significant information about Deception volcano activity. The detected seawater temperature increase, also observed in soil temperature readings, suggests rapid and near-simultaneous increase in geothermal activity with onset of caldera inflation and an increased number of seismic events observed in the following austral summer.

  11. Optimal scheduling of biocide dosing for seawater-cooled power and desalination plants

    KAUST Repository

    Mahfouz, Abdullah Bin

    2011-02-13

    Thermal desalination systems are typically integrated with power plants to exploit the excess heat resulting from the power-generation units. Using seawater in cooling the power plant and the desalination system is a common practice in many parts of the world where there is a shortage of freshwater. Biofouling is one of the major problems associated with the usage of seawater in cooling systems. Because of the dynamic variation in the power and water demands as well as the changes in the characteristics of seawater and the process, there is a need to develop an optimal policy for scheduling biocide usage and cleaning maintenance of the heat exchangers. The objective of this article is to introduce a systematic procedure for the optimization of scheduling the dosing of biocide and dechlorination chemicals as well as cleaning maintenance for a power production/thermal desalination plant. A multi-period optimization formulation is developed and solved to determine: the optimal levels of dosing and dechlorination chemicals; the timing of maintenance to clean the heat-exchange surfaces; and the dynamic dependence of the biofilm growth on the applied doses, the seawater-biocide chemistry, the process conditions, and seawater characteristics for each time period. The technical, economic, and environmental considerations of the system are accounted for. A case study is solved to elucidate the applicability of the developed optimization approach. © 2011 Springer-Verlag.

  12. The adsorber loop concept for the contact between seawater and adsorber granulate

    International Nuclear Information System (INIS)

    Koske, P.H.; Ohlrogge, K.

    1984-01-01

    For the production of 1 kg uranium from seawater about 10 9 kg seawater - depending on the extraction efficiency - have to be processed in a production plant. Such high seawater flows have to be put through adsorber beds the area of which depends on the flow velocity of the water in the bed. For a typical polyamidoxim (PAO) adsorber granulate with a grain size distribution of 0.3 to 1.2 mm the velocity in a fluidized bed is limited to about 1 cm/s in order to prevent carry out of the adsorber material. The consequences of this rather low bed velocity are large and expensive bed areas for technical production plants. The present paper deals with the so-called ''adsorber loop concept'' in which the adsorber granulate is carried along with the seawater to be processed in a loop-like configuration and is separated again from the water before this is leaving the adsorption unit. This concept enables considerably higher seawater velocities thus reducing the bed area. Theoretical considerations are presented together with experimental results from field tests. (author)

  13. An exploratory study on seawater-catalysed urine phosphorus recovery (SUPR).

    Science.gov (United States)

    Dai, Ji; Tang, Wen-Tao; Zheng, Yi-Se; Mackey, Hamish R; Chui, Ho Kwong; van Loosdrecht, Mark C M; Chen, Guang-Hao

    2014-12-01

    Phosphorus (P) is a crucial and non-renewable resource, while it is excessively discharged via sewage, significant amounts originating from human urine. Recovery of P from source-separated urine presents an opportunity not only to recover this precious resource but also to improve downstream sewage treatment works. This paper proposes a simple and economic method to recover urine derived P by using seawater as a low-cost precipitant to form struvite, as Hong Kong has practised seawater toilet flushing as an alternative water resource since 1958. Chemical reactions, process conditions and precipitate composition for P precipitation in urine have been investigated to develop this new urine P recovery approach. This study concluded that ureolysis extent in a urine-seawater mixture determines the reaction pH that in turn influences the P recovery efficiency significantly; 98% of urine P can precipitate with seawater within 10 min when 40-75% of the urea in urine is ureolysed; the urine to seawater ratio alters the composition of the precipitates. The P content in the precipitates was found to be more than 9% when the urine fraction was 40% or higher. Magnesium ammonium phosphate (MAP) was confirmed to be the predominant component of the precipitates. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Concentration and detection of hepatitis A virus and its indicator from artificial seawater using zeolite.

    Science.gov (United States)

    Cormier, Jiemin; Janes, Marlene

    2016-09-01

    Hepatitis A virus (HAV) infection is the leading worldwide cause of acute viral hepatitis, and outbreaks caused by this virus often occur in fecal polluted waters. Rapid concentration and detection of viral contamination in water environments can prevent economic loss and can identify the source of contamination within a short time. However, conventional methods for virus concentration are often laborious, time consuming, and subject to clogging. Furthermore, most methods require a secondary concentration step to reduce the final volume of samples. We developed a method to concentrate HAV from seawater using zeolite in aid of rapid detection. In this method,artificial seawater was inoculated with HAV (7-8 log TCID50) and filtered with zeolite. The viruses were then eluted from zeolite with sodium dodecyl sulfate and detected via real-time PCR (qPCR). Zeolite was able to concentrate HAV from artificial seawater with ∼99% efficiency in less than 5min and was more efficient in seawater than in fresh water. The entire concentration and detection can be done in approximately 2h. Compared to existing methods, this method eliminated the need for a secondary concentration step as well as the necessity to modify the pH or salinity of the seawater during concentration, and was simple and inexpensive. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Expression of aquaporin 3 in gills of the Atlantic killifish (Fundulus heteroclitus): Effects of seawater acclimation

    Science.gov (United States)

    Jung, Dawoon; Sato, J. Denry; Shaw, Joseph R.; Stanton, Bruce A.

    2011-01-01

    Estuarine fish, such as the Atlantic killifish (Fundulus heteroclitus), are constantly and rapidly exposed to changes in salinity. Although ion transport in killifish gills during acclimation to increased salinity has been studied extensively, no studies have examined the role of aquaglyceroporin 3 (AQP3), a water, glycerol, urea, and ammonia transporter, during acclimation to increased salinity in this sentinel environmental model organism. The goal of this study was to test the hypothesis that transfer from freshwater to seawater decreases AQP3 gene and protein expression in the gill of killifish. Transfer from freshwater to seawater decreased AQP3 mRNA in the gill after 1 day, but had no effect on total gill AQP3 protein abundance as determined by western blot. Quantitative confocal immunocytochemistry confirmed western blot studies that transfer from freshwater to seawater did not change total AQP3 abundance in the gill; however, immunocytochemistry revealed that the amount of AQP3 in pillar cells of secondary lamellae decreased in seawater fish, whereas the amount of AQP3 in mitochondrion rich cells (MRC) in primary filaments of the gill increased in seawater fish. This response of AQP3 expression is unique to killifish compared to other teleosts. Although the role of AQP3 in the gill of killifish has not been completely elucidated, these results suggest that AQP3 may play an important role in the ability of killifish to acclimate to increased salinity. PMID:22193757

  16. Substrate Use of Pseudovibrio sp. Growing in Ultra-Oligotrophic Seawater

    Science.gov (United States)

    Schwedt, Anne; Seidel, Michael; Dittmar, Thorsten; Simon, Meinhard; Bondarev, Vladimir; Romano, Stefano; Lavik, Gaute; Schulz-Vogt, Heide N.

    2015-01-01

    Marine planktonic bacteria often live in habitats with extremely low concentrations of dissolved organic matter (DOM). To study the use of trace amounts of DOM by the facultatively oligotrophic Pseudovibrio sp. FO-BEG1, we investigated the composition of artificial and natural seawater before and after growth. We determined the concentrations of dissolved organic carbon (DOC), total dissolved nitrogen (TDN), free and hydrolysable amino acids, and the molecular composition of DOM by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR-MS). The DOC concentration of the artificial seawater we used for cultivation was 4.4 μmol C L-1, which was eight times lower compared to the natural oligotrophic seawater we used for parallel experiments (36 μmol C L -1). During the three-week duration of the experiment, cell numbers increased from 40 cells mL-1 to 2x104 cells mL -1 in artificial and to 3x105 cells mL -1 in natural seawater. No nitrogen fixation and minor CO2 fixation (seawater, using unexpected organic compounds to fuel their energy, carbon and nitrogen requirements. PMID:25826215

  17. Survival behaviour and virulence of the fish pathogen Vibrio ordalii in seawater microcosms.

    Science.gov (United States)

    Ruiz, Pamela; Poblete-Morales, Matías; Irgang, Rute; Toranzo, Alicia E; Avendaño-Herrera, Ruben

    2016-06-15

    Vibrio ordalii, the causative agent of atypical vibriosis, is a Gram-negative, motile, rod-shaped bacterium that severely affects the salmonid aquaculture industry. V. ordalii has been biochemically, antigenically and genetically characterized. However, studies on the survival behaviour of this bacterium in aquatic environments are scarce, and there is no information regarding its disease transmission and infectious abilities outside of the fish host or regarding water as a possible reservoir. The present study investigated the survival behaviour of V. ordalii Vo-LM-06 and Vo-LM-18 in sterile and non-sterile seawater microcosms. After a year in sterile seawater without nutrients, 1% of both V. ordalii strains survived (~10(3) colony-forming units ml(-1)), and long-term maintenance did not affect bacterial biochemical or genetic properties. Additionally, V. ordalii maintained for 60 d in sterile seawater remained infective in rainbow trout Oncorhynchus mykiss. However, after 2 d of natural seawater exposure, this bacterium became non-culturable, indicating that autochthonous microbiota may play an important role in survival. Recuperation assays that added fresh medium to non-sterile microcosms did not favour V. ordalii recovery on solid media. Our results contribute towards a better understanding of V. ordalii survival behaviour in seawater ecosystems.

  18. Anthropogenic 236U in Danish Seawater: Global Fallout versus Reprocessing Discharge.

    Science.gov (United States)

    Qiao, Jixin; Steier, Peter; Nielsen, Sven; Hou, Xiaolin; Roos, Per; Golser, Robin

    2017-06-20

    This work focuses on the occurrence of 236 U in seawater along Danish coasts, which is the sole water-exchange region between the North Sea-Atlantic Ocean and the Baltic Sea. Seawater collected in 2013 and 2014 were analyzed for 236 U (as well as 238 U and 137 Cs). Our results indicate that 236 U concentrations in Danish seawater are distributed within a relatively narrow range of (3.6-8.2) × 10 7 atom/L and, to a certain extent, independent of salinity. 236 U/ 238 U atomic ratios in Danish seawater are more than 4 times higher than the estimated global fallout value of 1× 10 -9 . The levels of 236 U/ 238 U atomic ratios obtained are comparable to those reported for the open North Sea and much higher than several other open oceans worldwide. This indicates that besides the global fallout input, the discharges from the two major European nuclear reprocessing plants are dominating sources of 236 U in Danish seawater. However, unexpectedly high 236 U/ 238 U ratios as well as high 236 U concentrations were observed at low-salinity locations of the Baltic Sea. While this feature might be interpreted as a clue for another significant 236 U input in the Baltic Sea, it may also be caused by the complexity of water currents or slow turnover rate.

  19. Seawater-based wastewater accelerates development of aerobic granular sludge: A laboratory proof-of-concept.

    Science.gov (United States)

    Li, Xiling; Luo, Jinghai; Guo, Gang; Mackey, Hamish R; Hao, Tianwei; Chen, Guanghao

    2017-05-15

    This study aimed to develop an aerobic granular sludge process for the efficient treatment of highly saline wastewater and understand the granulation process in a seawater-based multi-ion matrix. Five identical sequencing batch airlift reactors (SBARs) are used to treat synthetic saline sewage with different proportions of real seawater (0%-100%). The results confirm that aerobic granular sludge can be successfully developed with various proportions of seawater up to 100% and show that seawater not only significantly accelerates granulation but also generates stronger granular structures than does freshwater. The increased presence of gel-forming alginate-like exopolysaccharides in the granules explains why a greater proportion of seawater leads to higher density and improves the cohesive strength of the granules. SEM-EDX analysis further revealed substantial presence of both Ca 2+ and Mg 2+ phosphate in the granule core as well as in the outer layers providing extra bridging forces in addition to alginate-like exopolysaccharides for accelerating the granule formation and maintaining the structure. It is hoped that this work could explore another approach for saline sewage treatment and bring some clues for the mystery of granulation mechanism. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Mercury isotope fractionation during transfer from post-desulfurized seawater to air.

    Science.gov (United States)

    Huang, Shuyuan; Lin, Kunning; Yuan, Dongxing; Gao, Yaqin; Sun, Lumin

    2016-12-15

    Samples of dissolved gaseous mercury (DGM) in the post-desulfurized seawater discharged from a coal-fired power plant together with samples of gaseous elemental mercury (GEM) over the post-desulfurized seawater surface were collected and analyzed to study the mercury isotope fractionation during transfer from post-desulfurized seawater to air. Experimental results showed that when DGM in the seawater was converted to GEM in the air, the δ 202 Hg and Δ 199 Hg values were changed, ranging from -2.98 to -0.04‰ and from -0.31 to 0.64‰, respectively. Aeration played a key role in accelerating the transformation of DGM to GEM, and resulted in light mercury isotopes being more likely to be enriched in the GEM. The ratio Δ 199 Hg/Δ 201 Hg was 1.626 in all samples, suggesting that mercury mass independent fractionation occurred owing to the nuclear volume effect during the transformation. In addition, mass independent fractionation of mercury even isotopes was found in the GEM above the post-desulfurized seawater surface in the aeration pool. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Effects of electrode settings on chlorine generation efficiency of electrolyzing seawater.

    Science.gov (United States)

    Hsu, Guoo-Shyng Wang; Hsia, Chih-Wei; Hsu, Shun-Yao

    2015-12-01

    Electrolyzed water has significant disinfection effects, can comply with food safety regulations, and is environmental friendly. We investigated the effects of immersion depth of electrodes, stirring, electrode size, and electrode gap on the properties and chlorine generation efficiency of electrolyzing seawater and its storage stability. Results indicated that temperature and oxidation-reduction potential (ORP) of the seawater increased gradually, whereas electrical conductivity decreased steadily in electrolysis. During the electrolysis process, pH values and electric currents also decreased slightly within small ranges. Additional stirring or immersing the electrodes deep under the seawater significantly increased current density without affecting its electric efficiency and current efficiency. Decreasing electrode size or increasing electrode gap decreased chlorine production and electric current of the process without affecting its electric efficiency and current efficiency. Less than 35% of chlorine in the electrolyzed seawater was lost in a 3-week storage period. The decrement trend leveled off after the 1 st week of storage. The electrolyzing system is a convenient and economical method for producing high-chlorine seawater, which will have high potential applications in agriculture, aquaculture, or food processing. Copyright © 2015. Published by Elsevier B.V.

  2. Effects of electrode settings on chlorine generation efficiency of electrolyzing seawater

    Directory of Open Access Journals (Sweden)

    Guoo-Shyng Wang Hsu

    2015-12-01

    Full Text Available Electrolyzed water has significant disinfection effects, can comply with food safety regulations, and is environmental friendly. We investigated the effects of immersion depth of electrodes, stirring, electrode size, and electrode gap on the properties and chlorine generation efficiency of electrolyzing seawater and its storage stability. Results indicated that temperature and oxidation-reduction potential (ORP of the seawater increased gradually, whereas electrical conductivity decreased steadily in electrolysis. During the electrolysis process, pH values and electric currents also decreased slightly within small ranges. Additional stirring or immersing the electrodes deep under the seawater significantly increased current density without affecting its electric efficiency and current efficiency. Decreasing electrode size or increasing electrode gap decreased chlorine production and electric current of the process without affecting its electric efficiency and current efficiency. Less than 35% of chlorine in the electrolyzed seawater was lost in a 3-week storage period. The decrement trend leveled off after the 1st week of storage. The electrolyzing system is a convenient and economical method for producing high-chlorine seawater, which will have high potential applications in agriculture, aquaculture, or food processing.

  3. Effect of different seawater Mg2 + concentrations on calcification in two benthic foraminifers

    Science.gov (United States)

    Mewes, Antje; Langer, Gerald; de Nooijer, Lennart Jan; Bijma, Jelle; Reichart, Gert-Jan

    2014-01-01

    Magnesium, incorporated in foraminiferal calcite (Mg/CaCC), is used intensively to reconstruct past seawater temperatures but, in addition to temperature, the Mg/CaCC of foraminiferal tests also depends on the ratio of Mg and Ca in seawater (Mg/CaSW). The physiological mechanisms responsible for these proxy relationships are still unknown. This culture study investigates the impact of different seawater [Mg2 +] on calcification in two benthic foraminiferal species precipitating contrasting Mg/CaCC: Ammonia aomoriensis, producing low-Mg calcite and Amphistegina lessonii, producing intermediate-Mg calcite. Foraminiferal growth and test thickness were determined and, Mg/Ca was analyzed using Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS). Results show that at present-day seawater Mg/CaSW of ~ 5, both species have highest growth rates, reflecting their adaptation to modern seawater element concentrations. Test thickness is not significantly affected by different Mg/CaSW. The relationship between Mg/CaSW and Mg/CaCC shows a distinct positive y-axis intercept, possibly reflecting at least two processes involved in foraminiferal biomineralization. The associated Mg partition (DMg) changes non-linearly with increasing Mg/CaSW, hence suggesting that the DMg is best described by an exponential function approaching an asymptote. PMID:26089590

  4. Online preconcentration ICP-MS analysis of rare earth elements in seawater

    Science.gov (United States)

    Hathorne, Ed C.; Haley, Brian; Stichel, Torben; Grasse, Patricia; Zieringer, Moritz; Frank, Martin

    2012-01-01

    The rare earth elements (REEs) with their systematically varying properties are powerful tracers of continental inputs, particle scavenging intensity and the oxidation state of seawater. However, their generally low (˜pmol/kg) concentrations in seawater and fractionation potential during chemical treatment makes them difficult to measure. Here we report a technique using an automated preconcentration system, which efficiently separates seawater matrix elements and elutes the preconcentrated sample directly into the spray chamber of an ICP-MS instrument. The commercially available "seaFAST" system (Elemental Scientific Inc.) makes use of a resin with ethylenediaminetriacetic acid and iminodiacetic acid functional groups to preconcentrate REEs and other metals while anions and alkali and alkaline earth cations are washed out. Repeated measurements of seawater from 2000 m water depth in the Southern Ocean allows the external precision (2σ) of the technique to be estimated at mine water reference materials diluted with a NaCl matrix with recommended values in the literature. This makes the online preconcentration ICP-MS technique advantageous for the minimal sample preparation required and the relatively small sample volume consumed (7 mL) thus enabling large data sets for the REEs in seawater to be rapidly acquired.

  5. Degradation of basalt fibre and glass fibre/epoxy resin composites in seawater

    International Nuclear Information System (INIS)

    Wei Bin; Cao Hailin; Song Shenhua

    2011-01-01

    Research highlights: → BFRP degradation process in seawater environment was first investigated. → The mass gain change includes two effects: absorption and extraction. → The interfacial adhesion of BFRP is bigger than GFRP. → After treated, the bending strength of BFRP is lower than GFRP. → Reducing the Fe 2+ in the basalt fibre could lead to a higher stability of BFRP. - Abstract: Epoxy resins reinforced, respectively, by basalt fibres and glass fibres were treated with a seawater solution for different periods of time. Both the mass gain ratio and the strength maintenance ratio of the composites were examined after the treatment. The fracture surfaces were characterized using scanning electron microscopy. The tensile and bending strengths of the seawater treated samples showed a decreasing trend with treating time. In general, the anti-seawater corrosion property of the basalt fibre reinforced composites was almost the same as that of the glass fibre reinforced ones. Based on the experimental results, possible corrosion mechanisms were explored, indicating that an effective lowering of the Fe 2+ content in the basalt fibre could lead to a higher stability for the basalt fibre reinforced composites in a seawater environment.

  6. Environmental DNA from seawater samples correlate with trawl catches of Subarctic, deepwater fishes

    DEFF Research Database (Denmark)

    Thomsen, Philip Francis; Møller, Peter Rask; Sigsgaard, Eva Egelyng

    2016-01-01

    such as bottom trawling, and on official reporting of global catches, which can be unreliable. Thus, there is need for alternative and non-invasive techniques for qualitative and quantitative oceanic fish surveys. Here we report environmental DNA (eDNA) metabarcoding of seawater samples from continental slope...... depths in Southwest Greenland. We collected seawater samples at depths of 188-918 m and compared seawater eDNA to catch data from trawling. We used Illumina sequencing of PCR products to demonstrate that eDNA reads show equivalence to fishing catch data obtained from trawling. Twenty-six families were...... found with both trawling and eDNA, while three families were found only with eDNA and two families were found only with trawling. Key commercial fish species for Greenland were the most abundant species in both eDNA reads and biomass catch, and interpolation of eDNA abundances between sampling sites...

  7. Electrochemical behaviour of aluminum alloy containing various stanum concentration tested in tropical seawater

    International Nuclear Information System (INIS)

    Siti Radiah Mohd Kamarudin; Muhamad Daud; Mohd Shariff Satar

    2004-01-01

    A study has been carried out to investigate the electrochemical behaviour of sacrificial anodes with different Sh concentration in tropical seawater environment. In this work, samples of Aluminum alloy with the addition of Sn in a range of 1. 0% - 1. 7% were tested in tropical seawater at room temperature. Tafel technique was used to produce a graph of the measured current versus potential for each different Sh concentration of aluminum alloy. The results show that the variation in alloy compositions affected the values of corrosion rate, corrosion current density and potential compared to alloy without Sn content. Furthermore, it was found that small addition of Sn successfully increased aluminum ion dissolution into seawater by producing a higher value of corrosion current density and corrosion rate. (Author)

  8. Microstructure and mechanical properties of recycled aggregate concrete in seawater environment.

    Science.gov (United States)

    Yue, Pengjun; Tan, Zhuoying; Guo, Zhiying

    2013-01-01

    This study aims to conduct research about the microstructure and basic properties of recycled aggregate concrete under seawater corrosion. Concrete specimens were fabricated and tested with different replacement percentages of 0%, 30%, and 60% after immersing in seawater for 4, 8, 12, and 16 months, respectively. The basic properties of recycled aggregate concrete (RAC) including the compressive strength, the elastic modulus, and chloride penetration depth were explicitly investigated. And the microstructure of recycled concrete aggregate (RCA) was revealed to find the seawater corrosion by using scanning electron microscope (SEM). The results showed that higher amount of the RCA means more porosity and less strength, which could lower both the compressive strength and resistance to chloride penetration. This research could be a guide in theoretical and numerical analysis for the design of RAC structures.

  9. Recovery of uranium from seawater-status of technology and needed future research and development

    International Nuclear Information System (INIS)

    Kelmers, A.D.

    1980-01-01

    A survey of recent publications concerning uranium recovery from seawater shows that considerable experimental work in this area is currently under way in Japan, less in European countries. Repeated screening programs have identified hydrous titanium oxide as the most promising candidate adsorbent; however, many of its properties, such as distribution coefficient, selectivity, loading, and possibly stability, appear to fall far short of those required for a practical recovery system. In addition, various evaluations of the energy efficiency of pumped or tidal power schemes for contacting the sorbent and seawater are in serious disagreement. Needed future research and development tasks have been identified. A fundamental development program to achieve significantly improved adsorbent properties would be required to permit economical recovery of uranium from seawater. Unresolved engineering aspects of such recovery systems are also identified and discussed. 63 references

  10. Recent developments in corrosion-resistant metallic alloys for construction of seawater pumps

    International Nuclear Information System (INIS)

    Glover, T.J.

    1988-01-01

    The location of power stations, refineries, and chemical plants on the coasts, the massive growth in desalination plants in the Middle East, and the growth of the North Sea offshore industry in the past 10 years have substantially increased the quantity of seawater being handled. Conveying this seawater from the sea to locations within the plant for cooling or desalting purposes requires many pumps, which traditionally have been constructed from cast iron, Ni-Resist, gunmetal, bronze, and stainless steel. The majority of these materials have given an adequate cost-to-life performance. The choice of materials for seawater pumps is continually growing; this article discusses the most likely choices commercially available: high-strength cupronickels; duplex stainless steels; high-alloy austenitic stainless steels; high-nickel alloys; and titanium and its alloys

  11. The Flakt-Hydro process: flue gas desulfurization by use of seawater

    Energy Technology Data Exchange (ETDEWEB)

    Xia, W.Z. [ABB China Limited, Shanghai (China)

    1999-07-01

    ABB's seawater scrubbing process (the Flakt-Hydro process) for flue gas desulfurization has recently triggered interest among power producers because of its simple operating principle and high reliability. The process uses seawater to absorb and neutralize sulfur dioxide in flue gases. The absorbed gas is oxidized and returned to the ocean in the form it originated in the first place, namely as dissolved sulfate salts. The process uses the seawater downstream of the power plant condensers. This paper gives an introduction to the basic principle of the process and presents some of the recent power plant applications, namely at the Paiton Private Power Project; Phase 1 (2 x 670 MWe) in Indonesia and at the Shenzhen West Power Plant, Unit 2 (300 MWe) in China.

  12. Facile Preparation of Porous WO3 Film for Photoelectrochemical Splitting of Natural Seawater

    Science.gov (United States)

    Shi, Yonghong; Li, Yuangang; Wei, Xiaoliang; Feng, Juan; Li, Huajing; Zhou, Wanyi

    2017-12-01

    Sunlight-driven natural seawater splitting provides a promising way for large-scale conversion and storage of solar energy. Here, we develop a facile and low-cost method via a deposition-annealing technique to fabricate porous WO3 film and demonstrate its application as a photoanode for natural seawater splitting. The WO3 film yields a photocurrent density of 1.95 mA cm-2 and possesses excellent stability at 1.23 V (versus RHE), under the illumination of 100 mW cm-2 (AM 1.5G). The photoelectrochemical performance is ascribed to the large surface area and good permeation of the electrolyte into the porous film. Furthermore, the photocurrent density remains almost the same during 3 h continuous light irradiation. The evolution of chlorine gas from seawater splitting was determined with qualitative and quantitative analyses, with a Faradic efficiency of about 56%.

  13. Environmental DNA from seawater samples correlate with trawl catches of Subarctic, deepwater fishes

    DEFF Research Database (Denmark)

    Thomsen, Philip Francis; Møller, Peter Rask; Sigsgaard, Eva Egelyng

    2016-01-01

    depths in Southwest Greenland. We collected seawater samples at depths of 188-918 m and compared seawater eDNA to catch data from trawling. We used Illumina sequencing of PCR products to demonstrate that eDNA reads show equivalence to fishing catch data obtained from trawling. Twenty-six families were......Remote polar and deepwater fish faunas are under pressure from ongoing climate change and increasing fishing effort. However, these fish communities are difficult to monitor for logistic and financial reasons. Currently, monitoring of marine fishes largely relies on invasive techniques...... such as bottom trawling, and on official reporting of global catches, which can be unreliable. Thus, there is need for alternative and non-invasive techniques for qualitative and quantitative oceanic fish surveys. Here we report environmental DNA (eDNA) metabarcoding of seawater samples from continental slope...

  14. Study of Henna (Lawsonia inermis) as Natural Corrosion Inhibitor for Aluminum Alloy in Seawater

    International Nuclear Information System (INIS)

    Nik, W B Wan; Zulkifli, F; Sulaiman, O; Samo, K B; Rosliza, R

    2012-01-01

    Commercial henna (Lawsonia inermis) was investigated to inhibit the corrosion of aluminum alloy through immersion in seawater. The aluminum alloy (5083) was prepared in size of 25mm × 25mm × 3mm. The immersion test was conducted in seawater with different concentration of henna, 100ppm, 300ppm, 500ppm for duration of 60 days. Four characterizations were performed in this study which was weight loss study, Fourier Transform Infrared (FTIR), Electrochemical Impedance Spectroscopy (EIS) and adsorption isotherm. The results indicated that henna has major constituents of lawsone which contributed to the chemisorptions or adsorption process by forming an isolation layers on the aluminum alloy surface which follows the Langmuir adsorption isotherm. It was found that the protection layer attached on metal was not permanent and precipitation occurred as the time increases. The highest inhibition efficiency was found at 88% (500ppm). This research found that henna is an excellent natural inhibitor for aluminum alloy in seawater.

  15. Interpretation FTIR spectrum of seawater and sediment in the Ambon Bay (TAD)

    Science.gov (United States)

    Patty, Diana Julaidy; Loupatty, Grace; Sopalauw, Fitria

    2017-01-01

    Research has done to interpretated FTIR spectrum of seawaters and sediment of the Ambon Bay (TAD). Analysis of samples of sediment and seawater using FTIR spectroscopy. The results showed the sand sediment samples identified Stretch bond OH group (3600-3500 cm-1), N-H Stretch (3400-3300 cm-1), C≡N (2250 cm-1), and NH bending (1640 to 1550 cm-1). And for seawater samples identified bonding group that is N-H Stretch (3400-3350 cm-1), N-H bending (1640 to 1550 cm-1) and C=O (1670-1640 cm-1). The existence of functional groups, carbonyl (C=O), alcohol (OH), carboxyl (COOH) can cause the complexation of metal cations. And the results showed analysis group N-O bond-containing compounds Nitro indicate heavy metal content of Lead (Pb) and group N-H bond-containing compound Amina indicate heavy metal content of Cadmium (Cd).

  16. Anthropogenic 236U in Danish Seawater: Global Fallout versus Reprocessing Discharge

    DEFF Research Database (Denmark)

    Qiao, Jixin; Steier, Peter; Nielsen, Sven Poul

    2017-01-01

    This work focuses on the occurrence of 236U in seawater along Danish coasts, which is the sole water-exchange region between the North Sea-Atlantic Ocean and the Baltic Sea. Seawater collected in 2013 and 2014 were analyzed for 236U (as well as 238U and 137Cs). Our results indicate that 236U...... seawater. However, unexpectedly high 236U/238U ratios as well as high 236U concentrations were observed at low-salinity locations of the Baltic Sea. While this feature might be interpreted as a clue for another significant 236U input in the Baltic Sea, it may also be caused by the complexity of water...... currents or slow turnover rate....

  17. Changing of Sumatra backswamp peat properties by seawater and zeolite application

    Science.gov (United States)

    Sarifuddin; Nasution, Z.; Rauf, A.; Mulyanto, B.

    2018-02-01

    This research attempts to improve the properties of backswamp peatsoil originated from Asahan District, North Sumatra Indonesia by adding sea water and zeolite using factorial randomized block design with volume of sea water as first factor, consisting of without seawater, 500 ml, 1000 ml and 1500 ml and second factor are dosages of zeolite consisting of without zeolite, 100 g, 200 g each 10 kgs of wet peat soil. at green house in faculty of agriculture University of Sumatra Utara (USU) Medan, Indonesia. The result showed that the application of seawater decreased pH, C/N and Cation Exchange Capacity and increased of base saturation of peat soil. Adding of zeolite minerals can buffered the increasing of acidity and Electric Conductivity caused by sea water application. Interaction seawater + zeolite decreased of C/N and increased of percent of base saturation.

  18. Determination of picomolar beryllium levels in seawater with inductively coupled plasma mass spectrometry following silica-gel preconcentration

    Energy Technology Data Exchange (ETDEWEB)

    Tazoe, Hirofumi, E-mail: tazoe@cc.hirosaki-u.ac.jp [Department of Radiation Chemistry, Institute of Radiation Emergency Mediation, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564 (Japan); College of Humanities and Sciences, Nihon University, 3-25-40, Sakurajosui, Setagaya-ku, Tokyo 156-8550 (Japan); Yamagata, Takeyasu [College of Humanities and Sciences, Nihon University, 3-25-40, Sakurajosui, Setagaya-ku, Tokyo 156-8550 (Japan); Obata, Hajime [Atmosphere and Ocean Research Institute, The Tokyo University, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8564 (Japan); Nagai, Hisao [College of Humanities and Sciences, Nihon University, 3-25-40, Sakurajosui, Setagaya-ku, Tokyo 156-8550 (Japan)

    2014-12-10

    Highlights: • We developesd the simplest and robust SPE method for ultra low picomolar level beryllium in seawater. • Just silica gel column can quantitatively adsorb beryllium in neutral pH condition containing natural seawater. • EDTA solution can eliminate seawater matrixes retaining Be in the column, which optimize to ICP-MS detemination. • Accurate and precise Be data have been obtained for natural seawater from North Pacific Ocean. - Abstract: A robust and rapid method for the determination of natural levels of beryllium (Be) in seawater was developed to facilitate mapping Be concentrations in the ocean. A solid-phase extraction method using a silica gel column was applied for preconcentration and purification of Be in seawater prior to determination of Be concentrations with inductively coupled plasma mass spectrometry (ICP-MS). Be was quantitatively adsorbed onto silica gel from solutions with pH values ranging from 6.3 to 9, including natural seawater. The chelating agent ethylenediamine tetraacetic acid was used to remove other ions in the seawater matrix (Na, Mg, and Ca) that interfere with the ICP-MS analysis. The reproducibility of the method was 3% based on triplicate analyses of natural seawater samples, and the detection limit was 0.4 pmol kg{sup −1} for 250 mL of seawater, which is sufficient for the analysis of seawater in the open ocean. The method was then used to determine the vertical profile of Be in the eastern North Pacific Ocean, which was found to be a recycled-type profile in which the Be concentration increased with depth from the surface (7.2 pmol kg{sup −1} at <200 m) to deep water (29.2 pmol kg{sup −1} from 3500 m to the bottom)

  19. Determination of picomolar beryllium levels in seawater with inductively coupled plasma mass spectrometry following silica-gel preconcentration

    International Nuclear Information System (INIS)

    Tazoe, Hirofumi; Yamagata, Takeyasu; Obata, Hajime; Nagai, Hisao

    2014-01-01

    Highlights: • We developesd the simplest and robust SPE method for ultra low picomolar level beryllium in seawater. • Just silica gel column can quantitatively adsorb beryllium in neutral pH condition containing natural seawater. • EDTA solution can eliminate seawater matrixes retaining Be in the column, which optimize to ICP-MS detemination. • Accurate and precise Be data have been obtained for natural seawater from North Pacific Ocean. - Abstract: A robust and rapid method for the determination of natural levels of beryllium (Be) in seawater was developed to facilitate mapping Be concentrations in the ocean. A solid-phase extraction method using a silica gel column was applied for preconcentration and purification of Be in seawater prior to determination of Be concentrations with inductively coupled plasma mass spectrometry (ICP-MS). Be was quantitatively adsorbed onto silica gel from solutions with pH values ranging from 6.3 to 9, including natural seawater. The chelating agent ethylenediamine tetraacetic acid was used to remove other ions in the seawater matrix (Na, Mg, and Ca) that interfere with the ICP-MS analysis. The reproducibility of the method was 3% based on triplicate analyses of natural seawater samples, and the detection limit was 0.4 pmol kg −1 for 250 mL of seawater, which is sufficient for the analysis of seawater in the open ocean. The method was then used to determine the vertical profile of Be in the eastern North Pacific Ocean, which was found to be a recycled-type profile in which the Be concentration increased with depth from the surface (7.2 pmol kg −1 at <200 m) to deep water (29.2 pmol kg −1 from 3500 m to the bottom)

  20. Viral lysis of photosynthesizing microbes as a mechanism for calcium carbonate nucleation in seawater

    Science.gov (United States)

    Lisle, John T.; Robbins, Lisa L.

    2016-01-01

    Removal of carbon through the precipitation and burial of calcium carbonate in marine sediments constitutes over 70% of the total carbon on Earth and is partitioned between coastal and pelagic zones. The precipitation of authigenic calcium carbonate in seawater, however, has been hotly debated because despite being in a supersaturated state, there is an absence of persistent precipitation. One of the explanations for this paradox is the geochemical conditions in seawater cannot overcome the activation energy barrier for the first step in any precipitation reaction; nucleation. Here we show that virally induced rupturing of photosynthetic cyanobacterial cells releases cytoplasmic-associated bicarbonate at concentrations ~23-fold greater than in the surrounding seawater, thereby shifting the carbonate chemistry toward the homogenous nucleation of one or more of the calcium carbonate polymorphs. Using geochemical reaction energetics, we show the saturation states (Ω) in typical seawater for calcite (Ω = 4.3), aragonite (Ω = 3.1), and vaterite (Ω = 1.2) are significantly elevated following the release and diffusion of the cytoplasmic bicarbonate (Ωcalcite = 95.7; Ωaragonite = 68.5; Ωvaterite = 25.9). These increases in Ω significantly reduce the activation energy for nuclei formation thresholds for all three polymorphs, but only vaterite nucleation is energetically favored. In the post-lysis seawater, vaterite's nuclei formation activation energy is significantly reduced from 1.85 × 10−17 J to 3.85 × 10−20 J, which increases the nuclei formation rate from highly improbable (nucleation of calcium carbonate in seawater describes a mechanism through which the initial step in the production of carbonate sediments may proceed. It also presents an additional role of photosynthesizing microbes and their viruses in marine carbon cycles and reveals these microorganisms are a collective repository for concentrated and reactive dissolved inorganic carbon (DIC

  1. The role of humic and fulvic acids in the phototransformation of phenolic compounds in seawater

    International Nuclear Information System (INIS)

    Calza, P.; Vione, D.; Minero, C.

    2014-01-01

    Humic substances (HS) are known to act as photosensitizers toward the transformation of pollutants in the surface layer of natural waters. This study focused on the role played by HS toward the transformation of xenobiotics in seawater, with the purpose of assessing the prevailing degradation routes. Phenol was chosen as model xenobiotic and its transformation was investigated under simulated sunlight in the presence of terrestrial or marine humic and fulvic acids, in pure water at pH 8, artificial seawater (ASW) or natural seawater (NSW). The following parameters were determined: (1) the phenol degradation rate; (2) the variation in HS concentration with irradiation time; (3) the production of transformation products; (4) the influence of iron species on the transformation process. Faster transformation of phenol was observed with humic acids (HA) compared to fulvic acids (SRFA), and transformation induced by both HA and SRFA was faster in ASW than that in pure water. These observations can be explained by assuming an interplay between different competing and sometimes opposite processes, including the competition between chloride, bromide and dissolved oxygen for reaction with HS triplet states. The analysis of intermediates formed in the different matrices under study showed the formation of several hydroxylated (hydroquinone, 1,4-benzoquinone, resorcinol) and condensed compounds (2,2′-bisphenol, 4,4′-bisphenol, 4-phenoxyphenol). Although 1,4-benzoquinone was the main transformation product, formation of condensed molecules was significant with both HA and SRFA. Experiments on natural seawater spiked with HS confirmed the favored formation of condensed products, suggesting a key role of humic matter in dimerization reactions occurring in saline water. - Highlights: • Phenol transformation in seawater can be photosensitized by humic substances. • Dimeric species are peculiar intermediates formed in the process. • Phenol degradation occurred faster with

  2. Flux patterns and membrane fouling propensity during desalination of seawater by forward osmosis

    KAUST Repository

    Li, Zhenyu; Yangali-Quintanilla, Victor; Valladares Linares, Rodrigo; Li, Qingyu; Zhan, Tong; Amy, Gary L.

    2012-01-01

    The membrane fouling propensity of natural seawater during forward osmosis was studied. Seawater from the Red Sea was used as the feed in a forward osmosis process while a 2. M sodium chloride solution was used as the draw solution. The process was conducted in a semi-batch mode under two crossflow velocities, 16.7. cm/s and 4.2. cm/s. For the first time reported, silica scaling was found to be the dominant inorganic fouling (scaling) on the surface of membrane active layer during seawater forward osmosis. Polymerization of dissolved silica was the major mechanism for the formation of silica scaling. After ten batches of seawater forward osmosis, the membrane surface was covered by a fouling layer of assorted polymerized silica clusters and natural organic matter, especially biopolymers. Moreover, the absorbed biopolymers also provided bacterial attachment sites. The accumulated organic fouling could be partially removed by water flushing while the polymerized silica was difficult to remove. The rate of flux decline was about 53% with a crossflow velocity of 16.7. cm/s while reaching more than 70% with a crossflow velocity of 4.2. cm/s. Both concentration polarization and fouling played roles in the decrease of flux. The salt rejection was stable at about 98% during seawater forward osmosis. In addition, an almost complete rejection of natural organic matter was attained. The results from this study are valuable for the design and development of a successful protocol for a pretreatment process before seawater forward osmosis and a cleaning method for fouled membranes. © 2011 Elsevier Ltd.

  3. Exposure to seawater increases intestinal motility in euryhaline rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Brijs, Jeroen; Hennig, Grant W; Gräns, Albin; Dekens, Esmée; Axelsson, Michael; Olsson, Catharina

    2017-07-01

    Upon exposure to seawater, euryhaline teleosts need to imbibe and desalinate seawater to allow for intestinal ion and water absorption, as this is essential for maintaining osmotic homeostasis. Despite the potential benefits of increased mixing and transport of imbibed water for increasing the efficiency of absorptive processes, the effect of water salinity on intestinal motility in teleosts remains unexplored. By qualitatively and quantitatively describing in vivo intestinal motility of euryhaline rainbow trout ( Oncorhynchus mykiss ), this study demonstrates that, in freshwater, the most common motility pattern consisted of clusters of rhythmic, posteriorly propagating contractions that lasted ∼1-2 min followed by a period of quiescence lasting ∼4-5 min. This pattern closely resembles mammalian migrating motor complexes (MMCs). Following a transition to seawater, imbibed seawater resulted in a significant distension of the intestine and the frequency of MMCs increased twofold to threefold with a concomitant reduction in the periods of quiescence. The increased frequency of MMCs was also accompanied by ripple-type contractions occurring every 12-60 s. These findings demonstrate that intestinal contractile activity of euryhaline teleosts is dramatically increased upon exposure to seawater, which is likely part of the overall response for maintaining osmotic homeostasis as increased drinking and mechanical perturbation of fluids is necessary to optimise intestinal ion and water absorption. Finally, the temporal response of intestinal motility in rainbow trout transitioning from freshwater to seawater coincides with previously documented physiological modifications associated with osmoregulation and may provide further insight into the underlying reasons shaping the migration patterns of salmonids. © 2017. Published by The Company of Biologists Ltd.

  4. Viral lysis of photosynthesizing microbes as a mechanism for calcium carbonate nucleation in seawater

    Science.gov (United States)

    Lisle, John T.; Robbins, Lisa L.

    2016-01-01

    Removal of carbon through the precipitation and burial of calcium carbonate in marine sediments constitutes over 70% of the total carbon on Earth and is partitioned between coastal and pelagic zones. The precipitation of authigenic calcium carbonate in seawater, however, has been hotly debated because despite being in a supersaturated state, there is an absence of persistent precipitation. One of the explanations for this paradox is the geochemical conditions in seawater cannot overcome the activation energy barrier for the first step in any precipitation reaction; nucleation. Here we show that virally induced rupturing of photosynthetic cyanobacterial cells releases cytoplasmic-associated bicarbonate at concentrations ~23-fold greater than in the surrounding seawater, thereby shifting the carbonate chemistry toward the homogenous nucleation of one or more of the calcium carbonate polymorphs. Using geochemical reaction energetics, we show the saturation states (Ω) in typical seawater for calcite (Ω = 4.3), aragonite (Ω = 3.1), and vaterite (Ω = 1.2) are significantly elevated following the release and diffusion of the cytoplasmic bicarbonate (Ωcalcite = 95.7; Ωaragonite = 68.5; Ωvaterite = 25.9). These increases in Ω significantly reduce the activation energy for nuclei formation thresholds for all three polymorphs, but only vaterite nucleation is energetically favored. In the post-lysis seawater, vaterite's nuclei formation activation energy is significantly reduced from 1.85 × 10−17 J to 3.85 × 10−20 J, which increases the nuclei formation rate from highly improbable (seawater describes a mechanism through which the initial step in the production of carbonate sediments may proceed. It also presents an additional role of photosynthesizing microbes and their viruses in marine carbon cycles and reveals these microorganisms are a collective repository for concentrated and reactive dissolved inorganic carbon (DIC) that is currently not accounted for

  5. Surfactant induced complex formation and their effects on the interfacial properties of seawater.

    Science.gov (United States)

    Guzmán, Eduardo; Santini, Eva; Benedetti, Alessandro; Ravera, Francesca; Ferrari, Michele; Liggieri, Libero

    2014-11-01

    The effect of a cationic surfactant, hexadecyltrimethylammonium bromide (CTAB), on the interfacial properties of seawater has been studied by dynamic and equilibrium surface tension and by dilational rheology essays. Important modifications of the surface tension and dilational rheology response have been observed already at the very low CTAB concentrations, where the effects due to the high ionic strength are negligible. The comparison with the effects of CTAB in different seawater models, or in natural seawater fractions, points out the establishment of strong interactions between the surfactant molecules and the lipophilic fraction of organic material dispersed/dissolved in seawater, affecting the interfacial activity of the molecules. Considering the biochemical richness of seawater, these results can be explained assuming interaction mechanisms and adsorption schemes similar to those speculated for protein and other macromolecules in the presence of surfactants, which in fact show similar features. Thus already at the low concentrations the surfactant molecules form highly surface-active complexes with part of the organic fraction of seawater. At the larger surfactant concentrations these complexes compete for adsorption with an excess of free CTAB molecules which, according to the thermodynamic conditions, are most favoured to occupy the liquid interface. The results of this study underline the important role of the sea organic content in enhancing the surface-activity of surfactants, which is relevant for a deeper understand of the direct and indirect effects of these types of pollutants on the physico-chemical environment in the sea coastal areas and develop mitigation strategies. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Comparative decay of Catellicoccus marimmalium and enterococci in beach sand and seawater.

    Science.gov (United States)

    Brown, Kendra I; Boehm, Alexandria B

    2015-10-15

    Most studies characterize microbial source tracking (MST) target performance using sensitivity and specificity metrics. However, it is important to also consider the temporal stability of MST targets in relation to regulated microbial pollutants. Differences among bacterial target stabilities may lead to erroneous conclusions about sources of contamination. The present study evaluates the relative stability of MST targets and fecal indicator organisms using the gull/pigeon-associated Catellicoccus marimammalium (CAT) marker and enterococci (ENT). The decay rates of CAT and ENT measured by culture (cENT) and QPCR (tENT) were compared in sand and seawater laboratory microcosms under environmentally relevant conditions (subject to tidal wetting versus no wetting in sand, and sunlit versus dark conditions in seawater). Bacterial targets were more persistent in beach sand than in seawater with decay rates on the order of 0.01-0.1 per day and 1 to 10 per day, respectively. Targets were more persistent in unwetted compared to wetted sand, and dark compared to sunlit seawater. During the first 8 days of the sand experiment, the decay rate k of CAT was greater than that of cENT. The decay rates of CAT, tENT, and cENT were similar in sand after day 8 and in dark seawater. In sunlit seawater, the decay rates were different between targets with kcENT > kCAT > ktENT. The decay rates presented here are useful for fate and transport models and also inform the use of MST marker concentrations to infer ENT sources in the environment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Assessing the pollution risk of a groundwater source field at western Laizhou Bay under seawater intrusion.

    Science.gov (United States)

    Zeng, Xiankui; Wu, Jichun; Wang, Dong; Zhu, Xiaobin

    2016-07-01

    Coastal areas have great significance for human living, economy and society development in the world. With the rapid increase of pressures from human activities and climate change, the safety of groundwater resource is under the threat of seawater intrusion in coastal areas. The area of Laizhou Bay is one of the most serious seawater intruded areas in China, since seawater intrusion phenomenon was firstly recognized in the middle of 1970s. This study assessed the pollution risk of a groundwater source filed of western Laizhou Bay area by inferring the probability distribution of groundwater Cl(-) concentration. The numerical model of seawater intrusion process is built by using SEAWAT4. The parameter uncertainty of this model is evaluated by Markov Chain Monte Carlo (MCMC) simulation, and DREAM(ZS) is used as sampling algorithm. Then, the predictive distribution of Cl(-) concentration at groundwater source field is inferred by using the samples of model parameters obtained from MCMC. After that, the pollution risk of groundwater source filed is assessed by the predictive quantiles of Cl(-) concentration. The results of model calibration and verification demonstrate that the DREAM(ZS) based MCMC is efficient and reliable to estimate model parameters under current observation. Under the condition of 95% confidence level, the groundwater source point will not be polluted by seawater intrusion in future five years (2015-2019). In addition, the 2.5% and 97.5% predictive quantiles show that the Cl(-) concentration of groundwater source field always vary between 175mg/l and 200mg/l. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. A Plan to Develop a Red Tide Warning System for Seawater Desalination Process Management

    Science.gov (United States)

    Kim, Tae Woo; Yun, Hong Sik

    2017-04-01

    The holt of the seawater desalination process for fifty five days due to the eight-month long red tide in 2008 in the Persian Gulf, the Middle East, had lost about 10 billion KRW. The POSCO Seawater Desalination facility, located in Gwangyang Bay Area in the Southern Sea, has produced 30,000 tons of fresh water per day since 2014. Since there has been an incident of red time in the area for three months in August, 2012, it is necessary to establish a warning system for red tide that threatens the stable operation of the seawater desalination facility. A red tide warning system can offer the seawater desalination facility manager customized services on red tide information and potential red tide inflow to the water intake. This study aimed to develop a red tide warning system in Gwangyang Bay Area by combining RS, modeling and monitoring technologies, which provides red tide forecasting information with which to effectively control the seawater desalination process. Using the proposed system, the seawater desalination facility manager can take phased measures to cope with the inflow of red tide. ACKNOWLEDGMENTS This research was supported by a grant(16IFIP-C088924-03) from Industrial Facilities & Infrastructure Research Program funded by Ministry of Land, Infrastructure and Transport(MOLIT) of the Korea government and the Korea Agency for Infrastructure Technology Advancement (KAIA). This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education(NRF-2014R1A1A2054975).

  9. Hydrogen evolution in enzymatic photoelectrochemical cell using modified seawater electrolytes produced by membrane desalination process

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Hyunku; Yoon, Jaekyung [Hydrogen Energy Research Center, New and Renewable Energy Research Division, Korea Institute of Energy Research, 71-2 Jang-dong, Yuseong-gu, Daejeon 305-343 (Korea); Bae, Sanghyun [Department of Environmental Engineering, Yonsei University, 234 Maeji-ri, Hungub-myun, Wonju, Gangwon-do 220-710 (Korea); Kim, Chunghwan; Kim, Suhan [Korea Institute of Water and Environment, K-Water, 462-1 Jeonmin-dong, Yuseong-gu, Daejeon 305-730 (Korea)

    2009-09-15

    In the near future, potential water shortages are expected to occur all over the world and this problem will have a significant influence on the availability of water for water-splitting processes, such as photocatalysis and electrolysis, as well as for drinking water. For this reason, it has been suggested that seawater could be used as an alternative for the various water industries including hydrogen production. Seawater contains a large amount of dissolved ion components, thus allowing it to be used as an electrolyte in photoelectrochemical (PEC) systems for producing hydrogen. Especially, the concentrate (retentate) stream shows higher salinity than the seawater fed to the membrane desalination process, because purified water (fresh water) is produced as the permeate stream and the waste brine is more concentrated than the original seawater. In this study, we investigated the hydrogen evolution rate in a photoelectrochemical system, including the preparation and characterization of an anodized tubular TiO{sub 2} electrode (ATTE) as both the photoanode and the cathode with the assistance of an immobilized hydrogenase enzyme and an external bias (solar cell), and the use of various qualities of seawater produced by membrane desalination processes as the electrolyte. The results showed that the rate of hydrogen evolution obtained using the nanofiltration (NF) retentate in the PEC system is ca. 105 {mu}mol/cm{sup 2} h, showing that this is an effective seawater electrolyte for hydrogen production, the optimum amount of enzyme immobilized on the cathode is ca. 3.66 units per geometrical unit area (1 cm x 1 cm), and the optimum external external bias supplied by the solar cell is 2.0 V. (author)

  10. The role of humic and fulvic acids in the phototransformation of phenolic compounds in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Calza, P., E-mail: paola.calza@unito.it; Vione, D.; Minero, C.

    2014-09-15

    Humic substances (HS) are known to act as photosensitizers toward the transformation of pollutants in the surface layer of natural waters. This study focused on the role played by HS toward the transformation of xenobiotics in seawater, with the purpose of assessing the prevailing degradation routes. Phenol was chosen as model xenobiotic and its transformation was investigated under simulated sunlight in the presence of terrestrial or marine humic and fulvic acids, in pure water at pH 8, artificial seawater (ASW) or natural seawater (NSW). The following parameters were determined: (1) the phenol degradation rate; (2) the variation in HS concentration with irradiation time; (3) the production of transformation products; (4) the influence of iron species on the transformation process. Faster transformation of phenol was observed with humic acids (HA) compared to fulvic acids (SRFA), and transformation induced by both HA and SRFA was faster in ASW than that in pure water. These observations can be explained by assuming an interplay between different competing and sometimes opposite processes, including the competition between chloride, bromide and dissolved oxygen for reaction with HS triplet states. The analysis of intermediates formed in the different matrices under study showed the formation of several hydroxylated (hydroquinone, 1,4-benzoquinone, resorcinol) and condensed compounds (2,2′-bisphenol, 4,4′-bisphenol, 4-phenoxyphenol). Although 1,4-benzoquinone was the main transformation product, formation of condensed molecules was significant with both HA and SRFA. Experiments on natural seawater spiked with HS confirmed the favored formation of condensed products, suggesting a key role of humic matter in dimerization reactions occurring in saline water. - Highlights: • Phenol transformation in seawater can be photosensitized by humic substances. • Dimeric species are peculiar intermediates formed in the process. • Phenol degradation occurred faster with

  11. Distribution of anti fouling biocides in coastal seawater of Egadi Islands

    International Nuclear Information System (INIS)

    Massanisso, Paolo; Ubaldi, Carla; Chiavarini, Salvatore; Pezza, Massimo; Cannarsa, Sigfrido; Bordone, Andrea

    2015-01-01

    The pollution level due to anti fouling biocides in the Marine Protected Area of Egadi Islands (MPA) has been evaluated by both grab and passive sampling. Analyses of tributyltin (TBT), diuron, irgarol, chlorothalonil and dichlofluanid have been carried out on seawater and sediments. The results indicate a good condition of the coastline, but further studies with passive sampling for TBT are required to help the MPA administrators to control the status of the seawater with a methodology suitable to reach the Environmental Quality Standard values established by the Water Framework Directive [it

  12. Reactivity of Aryl Halides for Reductive Dehalogenation in (Seawater Using Polymer-Supported Terpyridine Palladium Catalyst

    Directory of Open Access Journals (Sweden)

    Toshimasa Suzuka

    2015-05-01

    Full Text Available A polymer-supported terpyridine palladium complex was prepared. The complex was found to promote hydrodechlorination of aryl chlorides with potassium formate in seawater. Generally, reductive cleavage of aryl chlorides using transition metal catalysts is more difficult than that of aryl bromides and iodides (reactivity: I > Br > Cl; however, the results obtained did not follow the general trend. Therefore, we investigated the reaction inhibition agents and found a method to remove these inhibitors. The polymeric catalysts showed high catalytic activity and high reusability for transfer reduction in seawater.

  13. Application of electrochemical impedance spectroscopy to monitor seawater fouling on stainless steels and copper alloys

    International Nuclear Information System (INIS)

    Feron, D.

    1991-01-01

    Electrochemical impedance spectroscopy may be applied to detect and to follow seawater fouling. Experiments have been conducted with natural seawater flowing inside tube-electrodes at temperatures between 30 deg C and 85 deg C. With stainless steel tubes, mineral and organic foulings have been followed; a linear relationship between the dry weight of the organic fouling and its electrical resistance, has been observed. On copper alloy tubes, only mineral deposits have occurred and so have been detected by impedance spectroscopy. (Author). 5 refs., 6 figs

  14. Recovery of Uranium from Seawater: Modified Polyacrylonitrile Fibers as Selective Extractants

    Energy Technology Data Exchange (ETDEWEB)

    Alexandratos, Spiro D. [City Univ. (CUNY), NY (United States)

    2017-03-15

    A new bifunctional fiber has been prepared and found to have a significant loading capacity of uranium from real seawater. The fiber support is polyacrylonitrile and bifunctionality is provided by amidoxime and either diethylenetriamine (DETA) or ethylenediamine (EDA) ligands. The key feature is adjusting the hydrophilic /lipophilic balance within the fiber and this was best accomplished by partially acetylating or carboxylating EDA ligands. The bifunctional carboxylated EDA /AO fiber had a loading capacity of 3.83 mg U/g fiber at the Pacific Northwest National Laboratory with a 21 day contact time in real seawater.

  15. Selected bibliography for the extraction of uranium from seawater: chemical process and plant design feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Binney, S.E.; Polkinghorne, S.T.; Jante, R.R.; Rodman, M.R.; Chen, A.C.T.; Gordon, L.I.

    1979-02-01

    A selected annotated bibliography of 521 references was prepared as a part of a feasibility study of the extraction of uranium from seawater. For the most part, these references are related to the chemical processes whereby the uranium is removed from the seawater. A companion docment contains a similar bibliography of 471 references related to oceanographic and uranium extraction plant siting considerations, although some of the references are in common. The bibliography was prepared by computer retrieval from Chemical Abstracts, Nuclear Science Abstracts, Energy Data Base, NTIS, and Oceanic Abstracts. References are listed by author, country of author, and selected keywords.

  16. Development of Alloy Coating Process of Steel Pipe for Seawater service

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jong Man; Kwon, Taeg Kyu; Lee, Sang Hyeog [Daewoo Shipbuilding and Marine Engineering Co., Ltd., Okpo (Korea)

    2001-02-01

    The new alloy coating process was developed to apply steel pipe for seawater service. This process consists of Zn-Al hot-dip coating treatment immediately following after normal galvanizing treatment. The alloy coating process formed double layer after surface treatment, and the surface layer was similar to that of Galfan steel and the intermetallic layer was also similar to that of aluminized steel. The alloy coating layer protect steel pipe galvanically and provide steel pipe with high resistance to general corrosion of seawater. This new alloy coated steel pipe had also good weldability and adhesion strength of paints compared to galvanized steel. 5 refs., 14 figs.

  17. Selected bibliography for the extraction of uranium from seawater: chemical process and plant design feasibility study

    International Nuclear Information System (INIS)

    Binney, S.E.; Polkinghorne, S.T.; Jante, R.R.; Rodman, M.R.; Chen, A.C.T.; Gordon, L.I.

    1979-02-01

    A selected annotated bibliography of 521 references was prepared as a part of a feasibility study of the extraction of uranium from seawater. For the most part, these references are related to the chemical processes whereby the uranium is removed from the seawater. A companion docment contains a similar bibliography of 471 references related to oceanographic and uranium extraction plant siting considerations, although some of the references are in common. The bibliography was prepared by computer retrieval from Chemical Abstracts, Nuclear Science Abstracts, Energy Data Base, NTIS, and Oceanic Abstracts. References are listed by author, country of author, and selected keywords

  18. Physiological controls on seawater uptake and calcification in the benthic foraminifer Ammonia tepida

    Directory of Open Access Journals (Sweden)

    G. Nehrke

    2009-11-01

    Full Text Available To analyze the relation between seawater uptake and calcification, we incubated juveniles of the benthic foraminifer Ammonia tepida with various fluorescent probes and visualised them afterwards with confocal laser scanning microscopy. Vesicle membranes, Ca ions and vacuole fluids were followed with various tracers and showed for the first time that endocytosis of seawater is part of the calcification process in Ammonia tepida. Data on the intracellular Ca ion cycling allowed for calculating a preliminary cellular Ca budget during foraminiferal calcification. This showed that the free calcium involved in the production of a new chamber cannot be sufficient and suggests that foraminifera may precipitate their calcite from an amorphous precursor.

  19. Seawater corrosion tests for low-level radioactive waste drum containers

    International Nuclear Information System (INIS)

    Maeda, Sho; Wadachi, Yoshiki

    1985-11-01

    This report is a part of corrosion tests of drums under various environmental conditions (seawater, river water, coastal sand, inland soil and indoor and outdoor atmosphere) done at Japan Atomic Energy Research Institute sponsored by the Science and Technology Agency. The corrosion tests were started in November, 1977 and complated at March, 1984. This report describes the results of the seawater corrosion tests which are part of the final report, ''Corrosion Safety Demonstration Test'' (Japanese), and it is expected to contribute the safety assessment of sea dumping of low-level radioactive waste packages. (author)

  20. Analyzing the Propagation Behavior of a Gaussian Laser Beam through Seawater and Comparing with Atmosphere

    Directory of Open Access Journals (Sweden)

    F Dabbagh Kashani

    2013-12-01

    Full Text Available Study of the beam propagation behavior through oceanic media is a challenging subject. In this paper, based on generalized Collins integral, the mean irradiance profile of Gaussian laser beam propagation through ocean is investigated. Power In Special Bucket (PIB is calculated. Using analytical expressions and calculating seawater transmission, the effects of absorption and scattering on beam propagation are studied. Based on these formulae, propagation in ocean and atmosphere are compared. The effects of some optical and environmental specifications, such as divergence angle and chlorophyll concentration in seawater on beam propagation by using mean irradiance, PIB and analytical formula of oceanic transmission are studied. The calculated results are shown graphically.

  1. Seawater strontium isotopes, acid rain, and the Cretaceous-Tertiary boundary

    Science.gov (United States)

    Macdougall, J. D.

    1988-01-01

    A large bolide impact at the end of the Cretaceous would have produced significant amounts of nitrogen oxides by shock heating of the atmosphere. The resulting acid precipitation would have increased continental weathering greatly and could be an explanation for the observed high ratio of strontium-87 to strontium-86 in seawater at about this time, due to the dissolution of large amounts of strontium from the continental crust. Spikes to high values in the seawater strontium isotope record at other times may reflect similar episodes.

  2. Geochemical processes at a fresh/seawater interface in a shallow sandy aquifer

    DEFF Research Database (Denmark)

    Andersen, Martin Søgaard; Iversen, Vibeke Margrethe Nyvang; Postma, Diederik Jan

    2001-01-01

    Chemical processes in a natural fresh-/seawater mixing zone were studied in a shallow sandy aquifer. The dominant redox-processes are sulfate reduction and methanogenesis. Methanogenesis produces CO2, which causes calcite dissolution. The produced calcium induces ion exchange with sodium. The fin...... result of these interactions between different types of geochemical processes is an anoxic groundwater enriched in bicarbonate and sodium.......Chemical processes in a natural fresh-/seawater mixing zone were studied in a shallow sandy aquifer. The dominant redox-processes are sulfate reduction and methanogenesis. Methanogenesis produces CO2, which causes calcite dissolution. The produced calcium induces ion exchange with sodium. The final...

  3. Effect of medium-pressure UV-lamp treatment on disinfection by-products in chlorinated seawater swimming pool waters

    DEFF Research Database (Denmark)

    Cheema, Waqas Akram; Manasfi, Tarek; Kaarsholm, Kamilla Marie Speht

    2017-01-01

    Several brominated disinfection by-products (DBPs) are formed in chlorinated seawater pools, due to the high concentration of bromide in seawater. UV irradiation is increasingly employed in freshwater pools, because UV treatment photodegrades harmful chloramines. However, in freshwater pools it has...

  4. Sm-Nd in marine carbonates and phosphates: implications for Nd isotopes in seawater and crustal ages

    International Nuclear Information System (INIS)

    Shaw, H.F.; Wasserburg, G.J.

    1985-01-01

    This study explores the possibility of establishing Nd isotopic variations in seawater over geologic time. Calcite, aragonite and apatite are examined as possible phases recording seawater values of epsilonsubNd. Modern, biogenic and inorganically precipitated calcite and aragonite from marine environments were found to have Nd concentrations of from 0.2 to 70 ppb, showing that primary marine CaCO 3 contains little REE and that Nd/Ca is not greatly enhanced relative to seawater during carbonate precipitation. Very young marine limestone and dolomite containing no continental detritus have approx. 200 ppb Nd. All the carbonates are LREE enriched. Modern and very young Atlantic and Pacific carbonates have epsilonsub(Nd) in the range of shallow Atlantic and Pacific seawater respectively, implying that they derive their REE from local seawater. The Nd in well preserved carbonate fossils is 4 ppb, much greater than in their modern counterparts but like the high values found for carbonates in other studies. Results are also reported for apatite. They suggest that sedimentary apatite can be used to determine epsilonsub(Nd)(T) in ancient seawater. The seawater values so inferred range between -1.7 and -8.9 over the last 700 my and lie in the range of modern seawater, showing no evidence for drastic changes. (U.K.)

  5. Differential utility of the Bacteroidales DNA and RNA markers in the tiered approach for microbial source tracking in subtropical seawater.

    Science.gov (United States)

    Liu, Rulong; Cheng, Ken H F; Wong, Klaine; Cheng, Samuel C S; Lau, Stanley C K

    2015-07-01

    Source tracking of fecal pollution is an emerging component in water quality monitoring. It may be implemented in a tiered approach involving Escherichia coli and/or Enterococcus spp. as the standard fecal indicator bacteria (FIB) and the 16S rRNA gene markers of Bacteroidales as source identifiers. The relative population dynamics of the source identifiers and the FIB may strongly influence the implementation of such approach. Currently, the relative performance of DNA and RNA as detection targets of Bacteroidales markers in the tiered approach is not known. We compared the decay of the DNA and RNA of the total (AllBac) and ruminant specific (CF128) Bacteroidales markers with those of the FIB in seawater spiked with cattle feces. Four treatments of light and oxygen availability simulating the subtropical seawater of Hong Kong were tested. All Bacteroidales markers decayed significantly slower than the FIB in all treatments. Nonetheless, the concentrations of the DNA and RNA markers and E. coli correlated significantly in normoxic seawater independent of light availability, and in hypoxic seawater only under light. In hypoxic seawater without light, the concentrations of RNA but not DNA markers correlated with that of E. coli. Generally, the correlations between Enterococcus spp. and Bacteroidales were insignificant. These results suggest that either DNA or RNA markers may complement E. coli in the tiered approach for normoxic or hypoxic seawater under light. When light is absent, either DNA or RNA markers may serve for normoxic seawater, but only the RNA markers are suitable for hypoxic seawater.

  6. Preparation of Pt deposited nanotubular TiO2 as cathodes for enhanced photoelectrochemical hydrogen production using seawater electrolytes

    International Nuclear Information System (INIS)

    Nam, Wonsik; Oh, Seichang; Joo, Hyunku; Yoon, Jaekyung

    2011-01-01

    The purpose of this study was to develop effective cathodes to increase the production of hydrogen and use the seawater, an abundant resource in the earth as the electrolyte in photoelectrochemical systems. In order to fabricate the Pt/TiO 2 cathodes, various contents of the Pt precursor (0-0.4 wt%) deposited by the electrodeposition method were used. On the basis of the hydrogen evolution rate, 0.2 wt% Pt/TiO 2 was observed to exhibit the best performance among the various Pt/TiO 2 cathodes with the natural seawater and two concentrated seawater electrolytes obtained from single (nanofiltration) and combined membrane (nanofiltration and reverse osmosis) processes. The surface characterizations exhibited that crystal structures and morphological properties of Pt and TiO 2 found the results of XRD pattern and SEM/TEM images, respectively. - Graphical abstract: On the basis of photoelectrochemical hydrogen production, 0.2 wt% Pt/TiO 2 was observed to exhibit the best performance among the various Pt/TIO 2 cathodes with natural seawater. In comparison of hydrogen evolution rate with various seawater electrolytes, 0.2 wt% Pt/TiO 2 was found to show the better performance as cathode with the concentrated seawater electrolytes obtained from membrane. Highlights: → Pt deposited TiO 2 electrodes are used as cathode in PEC H 2 production. → Natural and concentrated seawater by membranes are used as electrolytes in PEC. → Pt/TiO 2 shows a good performance as cathode with seawater electrolytes. → H 2 evolution rate increases with more concentrated seawater electrolyte. → Highly saline seawater is useful resource for H 2 production.

  7. Predicting and measurement of pH of seawater reverse osmosis concentrates

    KAUST Repository

    Waly, Tarek

    2011-10-01

    The pH of seawater reverse osmosis plants (SWRO) is the most influential parameter in determining the degree of supersaturation of CaCO3 in the concentrate stream. For this, the results of pH measurements of the concentrate of a seawater reverse osmosis pilot plant were compared with pH calculations based on the CO2-HCO3 --CO3 2- system equilibrium equations. Results were compared with two commercial software programs from membrane suppliers and also the software package Phreeqc. Results suggest that the real concentrate pH is lower than that of the feed and that none of the used programs was able to predict correctly real pH values. In addition, the effect of incorporating the acidity constant calculated for NaCl medium or seawater medium showed a great influence on the concentrate pH determination. The HCO3 - and CO3 2- equilibrium equation using acidity constants developed for seawater medium was the only method able to predict correctly the concentrate pH. The outcome of this study indicated that the saturation level of the concentrate was lower than previously anticipated. This was confirmed by shutting down the acid and the antiscalants dosing without any signs of scaling over a period of 12 months. © 2011 Elsevier B.V.

  8. Direct measurement of uranium in seawater by inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Qiao, Jixin; Xu, Yihong

    2018-01-01

    samples taken from large volume of seawater stored in immovable containers for relatively long period (i.e., several months), the uranium concentration and salinity data showed slightly increasing trends with the increase of water depth in the container. Therefore, cautions need to be paid in sampling...

  9. Concentrating cesium-137 from seawater using resorcinol-formaldehyde resin for radioecological monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Egorin, Andrei; Tokar, Eduard; Tutov, Mikhail; Avramenko, Valentin [Institute of Chemistry FEBRAS, Vladivostok (Russian Federation); Far Eastern Federal Univ., Vladivostok (Russian Federation); Palamarchuk, Marina; Marinin, Dmitry [Institute of Chemistry FEBRAS, Vladivostok (Russian Federation)

    2017-04-01

    A method of preconcentrating cesium-137 from seawater using a resorcinol-formaldehyde resin, which enables one to optimize the ecological monitoring procedure, has been suggested. Studies of sorption of cesium-137 from seawater by resorcinol-formaldehyde resin have been performed, and it has been demonstrated that the cation exchanger is characterized by high selectivity with respect to cesium-137. It was found that the selectivity depended on the temperature of resin solidification and the seawater pH value. The maximal value of the cesium-137 distribution coefficient is equal to 4.1-4.5 x 10{sup 3} cm{sup 3} g{sup -1}. Under dynamic conditions, the ion-exchange resin capacity is 310-910 bed volumes depending on the seawater pH, whereas the efficiency of cesium removal exceeds 95%. The removal of more than 95% of cesium-137 has been attained using 1-3 M solutions of nitric acid: here, the eluate volume was 8-8.4 bed volumes. Application of 3 M solution of nitric acid results in resin degradation with the release of gaseous products.

  10. Effect of organic on chemical oxidation for biofouling control in pilot-scale seawater cooling towers

    KAUST Repository

    Al-Bloushi, Mohammed

    2017-09-14

    Due to the scarcity of potable water in many regions of the world, the demand for seawater as an alternative evaporative cooling medium in cooling towers (CTs) has increased significantly in recent years. Seawater make-up in CTs is deemed the most feasible because of its unlimited supply in the coastal areas of Gulf and Red Sea. However, the seawater CTs have higher challenges greatly mitigating their performances because it is an open system where biofouling and bio-corrosion occurring within the fillers and piping of recirculation systems. Their pilot-scale CTs were constructed to assess the performance of three types of oxidizing biocides or oxidants, namely chlorine, chlorine dioxide (ClO2) and ozone, for biofouling control. The test results showed that the addition of organic (5mg/L of methanol (MeOH)) increased the bacterial growth in CT basin. All oxidants were effective in keeping the microbial growth to the minimum. Oxidation increased the oxidation-reduction potential (ORP) level from 270 to 600mV. Total residual oxidant (TRO) was increased with oxidation but it was slightly increased with organic addition. Other parameters including pH, dissolved oxygen (DO), conductivity levels were not changed. However, higher formation of disinfection by-products (DBPs) was detected with chlorination and ozonation. This indicates the organic level should be limited in the oxidation for biofouling control in seawater CTs.

  11. Biodegradation of Halloysite Nanotubes-Polyester Nanocomposites Exposed to Short Term Seawater Immersion

    Directory of Open Access Journals (Sweden)

    Mohd Shahneel Saharudin

    2017-07-01

    Full Text Available Halloysite nanotubes (HNTs-polyester nanocomposites with four different concentrations were produced using solution casting technique and the biodegradation effect of short-term seawater exposure (120 h was studied. Monolithic polyester was observed to have the highest seawater absorption with 1.37%. At 0.3 wt % HNTs reinforcement, the seawater absorption dropped significantly to the lowest value of 0.77% due to increase of liquid diffusion path. For samples tested in dry conditions, the Tg, storage modulus, tensile properties and flexural properties were improved. The highest improvement of Tg was from 79.3 to 82.4 °C (increase 3.1 °C in the case of 0.3 wt % HNTs. This can be associated with the exfoliated HNTs particles, which restrict the mobility of polymer chains and thus raised the Tg. After seawater exposure, the Tg, storage modulus, tensile properties and flexural properties of polyester and its nanocomposites were decreased. The Young’s modulus of 0.3 wt % HNTs-polyester dropped 20% while monolithic polyester dropped up to 24% compared to their values in dry condition. Apart from that, 29% flexural modulus reduction was observed, which was 18% higher than monolithic polyester. In contrast, fracture toughness and surface roughness increased due to plasticization effect. The presence of various microbial communities caused gradual biodegradation on the microstructure of the polyester matrix as also evidently shown by SEM images.

  12. The Degradation of Mechanical Properties in Halloysite Nanoclay-Polyester Nanocomposites Exposed in Seawater Environment

    Directory of Open Access Journals (Sweden)

    Mohd Shahneel Saharudin

    2016-01-01

    Full Text Available Polyester based polymers are extensively used in aggressive marine environments; however, inadequate data is available on the effects of the seawater on the polyester based nanocomposites mechanical properties. This paper reports the effect of seawater absorption on the mechanical properties degradation of halloysite nanoclay-polyester nanocomposites. Results confirmed that the addition of halloysite nanoclay into polyester matrix was found to increase seawater uptake and reduce mechanical properties compared to monolithic polyester. The maximum decreases in microhardness, tensile and flexural properties, and impact toughness were observed in case of 1 wt% nanoclay. The microhardness decreased from 107 HV to 41.7 HV (61% decrease. Young’s modulus decreased from 0.6 GPa to 0.4 GPa (33% decrease. The flexural modulus decreased from 0.6 GPa to 0.34 GPa (43% decrease. The impact toughness dropped from 0.71 kJ/m2 to 0.48 kJ/m2 (32% decrease. Interestingly, the fracture toughness KIC increased with the addition of halloysite nanoclay due to the plasticization effect of the resin matrix. SEM images revealed the significant reduction in mechanical properties in case of 1 wt% reinforcement which is attributed to the degradation of the nanoclay-matrix interface influenced by seawater absorption and agglomeration of halloysite nanoclay.

  13. Effects of Bloom-Forming Algae on Fouling of Integrated Membrane Systems in Seawater Desalination

    Science.gov (United States)

    Ladner, David Allen

    2009-01-01

    Combining low- and high-pressure membranes into an integrated membrane system is an effective treatment strategy for seawater desalination. Low-pressure microfiltration (MF) and ultrafiltration (UF) membranes remove particulate material, colloids, and high-molecular-weight organics leaving a relatively foulant-free salt solution for treatment by…

  14. Extraction of uranium from seawater: evaluation of uranium resources and plant siting

    Energy Technology Data Exchange (ETDEWEB)

    Rodman, M.R.; Gordon, L.I.; Chen, A.C.T.

    1979-02-01

    This report deals with the evaluation of U.S. coastal waters as a uranium resource and with the selection of a suitable site for construction of a large-scale plant for uranium extraction. Evaluation of the resource revealed that although the concentration of uranium is quite low, about 3.3 ppB in seawater of average oceanic salinity, the amount present in the total volume of the oceans is very great, some 4.5 billion metric tons. Of this, perhaps only that uranium contained in the upper 100 meters or so of the surface well-mixed layer should be considered accessible for recovery, some 160 million tonnes. The study indicated that open ocean seawater acquired for the purpose of uranium extraction would be a more favorable resource than rivers entering the sea, cooling water of power plants, or the feed or effluent streams of existing plants producing other products such as magnesium, bromine, or potable and/or agricultural water from seawater. Various considerations led to the selection of a site for a pumped seawater coastal plant at a coastal location. Puerto Yabucoa, Puerto Rico was selected. Recommendations are given for further studies. 21 figures, 8 tables.

  15. Detection of methanogenic archaea in seawater particles and the digestive tract of a marine fish species

    NARCIS (Netherlands)

    van der Maarel, MJEC; Sprenger, W; Haanstra, R; Forney, LJ

    1999-01-01

    A methanogen-specific nested PCR approach was used to detect methanogenic archaea in seawater particles of the North Sea and the feces and the digestive tract of flounder (Platichthys flesus), a fish found in the North Sea. A number of 16S rDNA sequences with 97.6-99.5% similarity to

  16. Efficient purification and concentration of viruses from a large body of high turbidity seawater.

    Science.gov (United States)

    Sun, Guowei; Xiao, Jinzhou; Wang, Hongming; Gong, Chaowen; Pan, Yingjie; Yan, Shuling; Wang, Yongjie

    2014-01-01

    Marine viruses are the most abundant entities in the ocean and play crucial roles in the marine ecological system. However, understanding of viral diversity on large scale depends on efficient and reliable viral purification and concentration techniques. Here, we report on developing an efficient method to purify and concentrate viruses from large body of high turbidity seawater. The developed method characterizes with high viral recovery efficiency, high concentration factor, high viral particle densities and high-throughput, and is reliable for viral concentration from high turbidity seawater. Recovered viral particles were used directly for subsequent analysis by epifluorescence microscopy, transmission electron microscopy and metagenomic sequencing. Three points are essential for this method:•The sampled seawater (>150 L) was initially divided into two parts, water fraction and settled matter fraction, after natural sedimentation.•Both viruses in the water fraction concentrated by tangential flow filtration (TFF) and viruses isolated from the settled matter fraction were considered as the whole viral community in high turbidity seawater.•The viral concentrates were re-concentrated by using centrifugal filter device in order to obtain high density of viral particles.

  17. Wind power generation plant installed on cargo ship and marine resources recovery by seawater electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Murahara, M. [Tokyo Inst. of Technology, Tokyo (Japan)]|[Tokai Univ., Hiratsuka, Kanagawa (Japan); Seki, K. [Mingdao Univ., Taiwan (China)]|[Tokai Univ., Hiratsuka, Kanagawa (Japan). Research Inst. of Science and Technology

    2008-07-01

    Transmission loss from offshore wind turbine arrays is directly proportional to the length of the cable that brings power onshore. In order to minimize transmission loss, wind-generated electricity needs to be stored temporarily in a different form. Seawater, rock salt, and water of saline lakes can be desalinated and then electrolyzed to produce hydrogen. This paper presented a new method of offshore sodium production in Japan by seawater electrolysis. In this technique, sodium is manufactured on site by molten-salt electrolysis as a solid fuel. Sodium is electrolytically collected from the seawater or rock salt by the wind power generation. The sodium is then transported to a hydrogen power plant on land and then is added water to generate hydrogen for operating a hydrogen combustion turbine. The sodium hydroxide by-product is then supplied to the soda industry as a raw material. In seawater electrolysis, not only sodium but also fresh water, magnesium, calcium, potassium, sodium hydroxide, chlorine, oxygen, hydrogen, hydrochloric acid, and sulfuric acid are isolated and recovered as by-products. 5 refs., 6 figs.

  18. Flux dependency of particulate/colloidal fouling in seawater reverse osmosis systems

    KAUST Repository

    Salinas Rodrí guez, S. G.; Kennedy, Maria Dolores; Amy, Gary L.; Schippers, Jan Cornelis

    2012-01-01

    of seawater in reverse osmosis systems; (3) to project the increase in pressure due to cake resistance in reverse osmosis systems. In this research, flat ultrafiltration membranes (100, 50, 30 and 10 kDa) are used in a con- stant flux filtration mode to test

  19. Sunlight-enhanced calcareous deposition on cathodic stainless steel in natural seawater

    Digital Repository Service at National Institute of Oceanography (India)

    Eashwar, M.; SathishKumar, P.; Ravishankar, R.; Subramanian, G.

    In replicate series of experiments in natural seawater, one in full darkness and the other in a 1:1 diurnal cycle with as little as 5 percent of natural solar illumination, sunlight promoted calcareous deposition on cathodic stainless steel surfaces...

  20. New insight into the ternary complexes of uranyl carbonate in seawater.

    Science.gov (United States)

    Beccia, M R; Matara-Aho, M; Reeves, B; Roques, J; Solari, P L; Monfort, M; Moulin, C; Den Auwer, C

    2017-11-01

    Uranium is naturally present in seawater at trace levels and may in some cases be present at higher concentrations, due to anthropogenic nuclear activities. Understanding uranium speciation in seawater is thus essential for predicting and controlling its behavior in this specific environmental compartment and consequently, its possible impact on living organisms. The carbonato calcic complex Ca 2 UO 2 (CO 3 ) 3 was previously identified as the main uranium species in natural seawater, together with CaUO 2 (CO 3 ) 3 2- . In this work, we further investigate the role of the alkaline earth cation in the structure of the ternary uranyl-carbonate complexes. For this purpose, artificial seawater, free of Mg 2+ and Ca 2+ , using Sr 2+ as a spectroscopic probe was prepared. Combining TRLIF and EXAFS spectroscopy, together with DFT and theoretical thermodynamic calculations, evidence for the presence of Sr alkaline earth counter ion in the complex structure can be asserted. Furthermore, data suggest that when Ca 2+ is replaced by Sr 2+ , SrUO 2 (CO 3 ) 3 2- is the main complex in solution and it occurs with the presence of at least one monodentate carbonate in the uranyl coordination sphere. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Aerobic methanotrophic communities at the Red Sea brine-seawater interface

    KAUST Repository

    Abdallah, Rehab Z.

    2014-09-23

    Abdallah RZ, Adel M, Ouf A, Sayed A, Ghazy MA, Alam I, Essack M, Lafi FF, Bajic VB, El-Dorry H and Siam R (2014) Aerobic methanotrophic communities at the Red Sea brine-seawater interface. Front. Microbiol. 5:487. doi: 10.3389/fmicb.2014.00487

  2. Towards a quality-controlled and accessible Pitzer model for seawater and related systems

    Directory of Open Access Journals (Sweden)

    David Turner

    2016-09-01

    Full Text Available We elaborate the need for a quality-controlled chemical speciation model for seawater and related natural waters, work which forms the major focus of SCOR Working Group 145. Model development is based on Pitzer equations for the seawater electrolyte and trace components. These equations can be used to calculate activities of dissolved ions and molecules and, in combination with thermodynamic equilibrium constants, chemical speciation. The major tasks to be addressed are ensuring internal consistency of the Pitzer model parameters (expressing the interactions between pairs and triplets of species, which ultimately determines the calculated activities, assessing uncertainties, and identifying important data gaps that should be addressed by new measurements. It is recognised that natural organic matter plays an important role in many aquatic ecosystems, and options for including this material in a Pitzer-based model are discussed. The process of model development begins with the core components which include the seawater electrolyte and the weak acids controlling pH. This core model can then be expanded by incorporating additional chemical components, changing the standard seawater composition and/or broadening the range of temperature and pressure, without compromising its validity. Seven important areas of application are identified: open ocean acidification; micro-nutrient biogeochemistry and geochemical tracers; micro-nutrient behaviour in laboratory studies; water quality in coastal and estuarine waters; cycling of nutrients and trace metals in pore waters; chemical equilibria in hydrothermal systems; brines and salt lakes.

  3. Mathematical modelling of a self-polishing antifouling paint exposed to seawater: A parameter study

    DEFF Research Database (Denmark)

    Kiil, Søren; Pedersen, M. S.; Dam-Johansen, Kim

    2002-01-01

    , and to suggest ways of controlling biocide release rates. A case study with an antifouling paint based on the well-known tributyltin self-polishing copolymer system showed that the rate of paint polishing was influenced, to various degrees, by the following parameters: seawater pH and concentration of Na...

  4. A community-wide intercomparison exercise for the determination of dissolved iron in seawater

    NARCIS (Netherlands)

    Bowie, A.R.; Achterberg, E.P.; Croot, P.l.; de Baar, H.J.W.; Laan, P.; Moffett, J.W; Ussher, S.; Worsfold, P.J.

    2006-01-01

    The first large-scale international intercomparison of analytical methods for the determination of dissolved iron in seawater was carried out between October 2000 and December 2002. The exercise was conducted as a rigorously "blind" comparison of 7 analytical techniques by 24 international

  5. Geophysics and geochemistry techniques in seawater intrusion monitoring and mapping at Kerpan, Kedah

    International Nuclear Information System (INIS)

    Bashillah Baharuddin; Nazrul Hizam Yusoff; Abdul Rahim Samsudin

    2002-01-01

    Lately, groundwater contamination has become a public concern. Seawater intrusion is not a new issue, and only it started to magnetize attention from lots of parties since at also a contributor to groundwater contamination. Therefore a study about seawater intrusion is carried out and the selected area is Kerpan, Kedah. This information is useful particularly in agriculture because any contamination that cause by chlorine (seawater) intrusion can affect crops production. For Kerpan Project, two modernized electric resistivity survey instruments, the Terrameter SAS 4000 and SAS 300C are used which provide image profiles. This profiles have the capability to access a comprehensive geological interpretation by examine subsurface electric characteristics such as resistivity, permittivity and chargeability (John, 1997). At Kerpan, Kedah a study about salinity in canals was also carried out to monitor if there is any seawater intrusion that can get through the canals. The study was done since that the canals are directly to the sea. Instrument for this study is STD 12-plus. (Author)

  6. Sulphide production and corrosion in seawaters during exposure to FAME diesel.

    Science.gov (United States)

    Lee, Jason S; Ray, Richard I; Little, Brenda J; Duncan, Kathleen E; Oldham, Athenia L; Davidova, Irene A; Suflita, Joseph M

    2012-01-01

    Experiments were designed to evaluate the corrosion-related consequences of storing/transporting fatty acid methyl ester (FAME) alternative diesel fuel in contact with natural seawater. Coastal Key West, FL (KW), and Persian Gulf (PG) seawaters, representing an oligotrophic and a more organic- and inorganic mineral-rich environment, respectively, were used in 60 day incubations with unprotected carbon steel. The original microflora of the two seawaters were similar with respect to major taxonomic groups but with markedly different species. After exposure to FAME diesel, the microflora of the waters changed substantially, with Clostridiales (Firmicutes) becoming dominant in both. Despite low numbers of sulphate-reducing bacteria in the original waters and after FAME diesel exposure, sulphide levels and corrosion increased markedly due to microbial sulphide production. Corrosion morphology was in the form of isolated pits surrounded by an intact, passive surface with the deepest pits associated with the fuel/seawater interface in the KW exposure. In the presence of FAME diesel, the highest corrosion rates measured by linear polarization occurred in the KW exposure correlating with significantly higher concentrations of sulphur and chlorine (presumed sulphide and chloride, respectively) in the corrosion products.

  7. Herbicides from the Charente river and the estuarine zone (Marennes-Oleron) to the coastal seawater

    International Nuclear Information System (INIS)

    Scribe, P.; Chouakri, S.; Dupas, S.

    1999-01-01

    Spatial distribution of herbicides was investigated in the fluvial section, the estuary of the Charente river and the coastal zone (Marennes-Oleron). Monthly samplings were performed on a fluvial section from Angouleme to Saintes, at Chalonne, Nersac, Sireuil, Bourg and Brives from 1993 onwards. Estuarine and coastal sea-waters were sampled during two cruises in May 1991 and February 1992

  8. Fluorescent microarray for multiplexed quantification of environmental contaminants in seawater samples

    Science.gov (United States)

    The development of a fluorescent multiplexed microarray platform able to detect and quantify a wide variety of pollutants in seawater is reported. The microarray platform has been manufactured by spotting 6 different bioconjugate competitors and it uses a cocktail of 6 monoclonal and polyclonal anti...

  9. Diversity of bacterioplankton in the surface seawaters of Drake Passage near the Chinese Antarctic station.

    Science.gov (United States)

    Xing, Mengxin; Li, Zhao; Wang, Wei; Sun, Mi

    2015-07-01

    The determination of relative abundances and distribution of different bacterial groups is a critical step toward understanding the functions of various bacteria and its surrounding environment. Few studies focus on the taxonomic composition and functional diversity of microbial communities in Drake Passage. In this study, marine bacterioplankton communities from surface seawaters at five locations in Drake Passage were examined by 16S rRNA gene sequence analyses. The results indicated that psychrophilic bacteria were the most abundant group in Drake Passage, and mainly made up of Bacillus, Aeromonas, Psychrobacter, Pseudomonas and Halomonas. Diversity analysis showed that surface seawater communities had no significant correlation with latitudinal gradient. Additionally, a clear difference among five surface seawater communities was evident, with 1.8% OTUs (only two) belonged to Bacillus consistent across five locations and 71% OTUs (80) existed in only one location. However, the few cosmopolitans had the largest population sizes. Our results support the hypothesis that the dominant bacterial groups appear to be analogous between geographical sites, but significant differences may be detected among rare bacterial groups. The microbial diversity of surface seawaters would be liable to be affected by environmental factors. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. Solid State Sensor for Simultaneous Measurement of Total Alkalinity and pH of Seawater.

    Science.gov (United States)

    Briggs, Ellen M; Sandoval, Sergio; Erten, Ahmet; Takeshita, Yuichiro; Kummel, Andrew C; Martz, Todd R

    2017-09-22

    A novel design is demonstrated for a solid state, reagent-less sensor capable of rapid and simultaneous measurement of pH and Total Alkalinity (A T ) using ion sensitive field effect transistor (ISFET) technology to provide a simplified means of characterization of the aqueous carbon dioxide system through measurement of two "master variables": pH and A T . ISFET-based pH sensors that achieve 0.001 precision are widely used in various oceanographic applications. A modified ISFET is demonstrated to perform a nanoliter-scale acid-base titration of A T in under 40 s. This method of measuring A T , a Coulometric Diffusion Titration, involves electrolytic generation of titrant, H + , through the electrolysis of water on the surface of the chip via a microfabricated electrode eliminating the requirement of external reagents. Characterization has been performed in seawater as well as titrating individual components (i.e., OH - , HCO 3 - , CO 3 2- , B(OH) 4 - , PO 4 3- ) of seawater A T . The seawater measurements are consistent with the design in reaching the benchmark goal of 0.5% precision in A T over the range of seawater A T of ∼2200-2500 μmol kg -1 which demonstrates great potential for autonomous sensing.

  11. Seawater desalination plant using nuclear heating reactor coupled with MED process

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A small size plant for seawater desalination using nuclear heating reactor coupled with MED process was developed by the Institute of Nuclear Energy Technology, Tsinghua University, China. This seawater desalination plant was designed to supply potable water demand to some coastal location or island where both fresh water and energy source are severely lacking. It is also recommended as a demonstration and training facility for seawater desalination using nuclear energy. The design of small size of seawater desalination plant couples two proven technologies: Nuclear Heating Reactor (NHR) and Multi-Effect Destination (MED) process. The NHR design possesses intrinsic and passive safety features, which was demonstrated by the experiences of the project NHR-5. The intermediate circuit and steam circuit were designed as the safety barriers between the NHR reactor and MED desalination system. Within 10~200 MWt of the power range of the heating reactor, the desalination plant could provide 8000 to 150,000 m3/d of high quality potable water. The design concept and parameters, safety features and coupling scheme are presented.

  12. Biofouling of inlet pipes affects water quality in running seawater aquaria and compromises sponge cell proliferation

    NARCIS (Netherlands)

    Alexander, B.E.; Mueller, B.; Vermeij, M.J.A.; van der Geest, H.H.G.; de Goeij, J.M.

    2015-01-01

    Marine organism are often kept, cultured, and experimented on in running seawater aquaria. However, surprisingly little attention is given to the nutrient composition of the water flowing through these systems, which is generally assumed to equal in situ conditions, but may change due to the

  13. Extraction of uranium from seawater: evaluation of uranium resources and plant siting

    International Nuclear Information System (INIS)

    Rodman, M.R.; Gordon, L.I.; Chen, A.C.T.

    1979-02-01

    This report deals with the evaluation of U.S. coastal waters as a uranium resource and with the selection of a suitable site for construction of a large-scale plant for uranium extraction. Evaluation of the resource revealed that although the concentration of uranium is quite low, about 3.3 ppB in seawater of average oceanic salinity, the amount present in the total volume of the oceans is very great, some 4.5 billion metric tons. Of this, perhaps only that uranium contained in the upper 100 meters or so of the surface well-mixed layer should be considered accessible for recovery, some 160 million tonnes. The study indicated that open ocean seawater acquired for the purpose of uranium extraction would be a more favorable resource than rivers entering the sea, cooling water of power plants, or the feed or effluent streams of existing plants producing other products such as magnesium, bromine, or potable and/or agricultural water from seawater. Various considerations led to the selection of a site for a pumped seawater coastal plant at a coastal location. Puerto Yabucoa, Puerto Rico was selected. Recommendations are given for further studies. 21 figures, 8 tables

  14. A review of uranium extraction from seawater: Recent international research and development

    International Nuclear Information System (INIS)

    Nor Azillah Fatimah Othman; Jamaliah Sharif; Siti Fatahiyah Mohamad

    2012-01-01

    Radiation-induced grafting co-polymerization is widely used technique to produce high performance chemically active polymer materials for adsorption and separation processes on the basis of various commercial polymers available in different forms (films, fibers, resins, textiles, powders). The design and synthesis of polymer supported reagents that can selectively complex metal ions from multi-component solutions have been an important area of research during the last decades. Uranyl ions have been one of the target ions to be removed from aqueous systems. Despite the very low uranium concentration (3.3 ppb) in seawater, its total amount reaches 4 x 10 12 kg, that is equivalent to 1000 times of the mine uranium. To recover an economically significant quantity of uranium from seawater, an adsorption method using a suitable solid adsorbent seems to be feasible with regard to economical and environmental impacts. Extensive investigations of adsorbents capable of recovering uranium from seawater and aqueous systems have been carried out during the last two decades especially in Japan Atomic Energy Agency, Japan but until now, this method is not feasible for mass production. In this paper, recent international activities are summarized, on both the laboratory scale experiments and large scale marine experiments. Research and Development opportunities are discussed for improving the system performance and making the collection of uranium from seawater more economically competitive. (author)

  15. Intensively exploited Mediterranean aquifers: resilience and proximity to critical points of seawater intrusion

    Science.gov (United States)

    Mazi, K.; Koussis, A. D.; Destouni, G.

    2013-11-01

    We investigate here seawater intrusion in three prominent Mediterranean aquifers that are subject to intensive exploitation and modified hydrologic regimes by human activities: the Nile Delta Aquifer, the Israel Coastal Aquifer and the Cyprus Akrotiri Aquifer. Using a generalized analytical sharp-interface model, we review the salinization history and current status of these aquifers, and quantify their resilience/vulnerability to current and future sea intrusion forcings. We identify two different critical limits of sea intrusion under groundwater exploitation and/or climatic stress: a limit of well intrusion, at which intruded seawater reaches key locations of groundwater pumping, and a tipping point of complete sea intrusion upto the prevailing groundwater divide of a coastal aquifer. Either limit can be reached, and ultimately crossed, under intensive aquifer exploitation and/or climate-driven change. We show that sea intrusion vulnerability for different aquifer cases can be directly compared in terms of normalized intrusion performance curves. The site-specific assessments show that the advance of seawater currently seriously threatens the Nile Delta Aquifer and the Israel Coastal Aquifer. The Cyprus Akrotiri Aquifer is currently somewhat less threatened by increased seawater intrusion.

  16. Loma salmonae (Protozoa: Microspora) infections in seawater reared coho salmon Oncorhynchus kisutch

    Science.gov (United States)

    Kent, M.L.; Elliott, D.G.; Groff, J.M.; Hedrick, R.P.

    1989-01-01

    Loma salmonae (Putz et al., 1965) infections were observed in five groups of coho salmon, Oncorhynchus kisutch, reared in seawater net-pens in Washington State, U.S.A. in 1984–1986. Ultrastructural characteristics, size of spores, tissues and host infected, and geographical location identified the microsporidium as Loma salmonae. Preserved spores measured 4.4×2.3 (4–5.6×2–2.4) μm and exhibited 14–17 turns of the polar filament. Infections were evident in the gills of some fish before seawater entry, but few parasites were observed and they caused little tissue damage. Infections observed in fish after transfer to seawater were associated with significant pathological changes in the gills. A mixed inflammatory infiltrate was associated with ruptured microsporidian xenomas within the vessels and interstitium of the primary lamellae. Microsporidian spores were dispersed throughout the lesions and were often seen inside phagocytes. The parasite was also observed in the heart, spleen, kidney and pseudobranchs; however, the inflammatory lesions were common only in the heart.Monthly examination of fish after transfer to seawater showed peak prevalences (33–65%) of gill infections during the summer. Although moribund fish were often infected with other pathogens, the high prevalence of L. salmonae infections and the severity of the lesions it caused, suggested that this parasite significantly contributed to the recurrent summer mortalities observed at this net-pen site.

  17. Complete Genome Sequence of Photobacterium sp. Strain J15, Isolated from Seawater of Southwestern Johor, Malaysia.

    Science.gov (United States)

    Roslan, Noordiyanah Nadhirah; Sabri, Suriana; Oslan, Siti Nurbaya; Baharum, Syarul Nataqain; Leow, Thean Chor

    2016-07-28

    Here, we report the genome sequences of Photobacterium sp. strain J15, isolated from seawater in Johor, Malaysia, with the ability to produce lipase and asparaginase. The PacBio genome sequence analysis of Photobacterium sp. strain J15 generated revealed its potential in producing enzymes with different catalytic functions. Copyright © 2016 Roslan et al.

  18. Colwellia agarivorans sp. nov., an agar-digesting marine bacterium isolated from coastal seawater

    Science.gov (United States)

    A novel Gram-stain-negative, facultatively anaerobic, yellowish and agar-digesting marine bacterium, designated strain QM50**T, was isolated from coastal seawater in an aquaculture site near Qingdao, China. Phylogenetic analysis based on 16S rDNA sequences revealed that the novel isolate represented...

  19. Development of detection techniques for monitoring and optimizing biocide dosing in seawater flooding systems

    NARCIS (Netherlands)

    Al-Moniee, M.A.; Al-Abeedi, F.N.; Koopal, C.G.J.; Akmal, N.; Sanders, P.F.; Veen, S. van

    2013-01-01

    Anaerobic microorganisms which are frequently associated with corrosion fail Control of bacterial activity are posing major challenge in Saudi Arabia's massive seawater flooding systems. Biocides are used to control bacteria throughout the oil industry. A study to explore the feasibility to develop

  20. Seawater desalination with solar-energy-integrated vacuum membrane distillation system

    Directory of Open Access Journals (Sweden)

    Fang Wang

    2017-03-01

    Full Text Available This study designed and tested a novel type of solar-energy-integrated vacuum membrane distillation (VMD system for seawater desalination under actual environmental conditions in Wuhan, China. The system consists of eight parts: a seawater tank, solar collector, solar cooker, inclined VMD evaporator, circulating water vacuum pump, heat exchanger, fresh water tank, and brine tank. Natural seawater was used as feed and a hydrophobic hollow-fiber membrane module was used to improve seawater desalination. The experiment was conducted during a typical summer day. Results showed that when the highest ambient temperature was 33 °C, the maximum value of the average solar intensity was 1,080 W/m2. The system was able to generate 36 kg (per m2 membrane module distilled fresh water during 1 day (7:00 am until 6:00 pm, the retention rate was between 99.67 and 99.987%, and electrical conductivity was between 0.00276 and 0.0673 mS/cm. The average salt rejection was over 90%. The proposed VMD system shows favorable potential application in desalination of brackish waters or high-salt wastewater treatment, as well.

  1. Simulation-Optimization Model for Seawater Intrusion Management at Pingtung Coastal Area, Taiwan

    Science.gov (United States)

    Huang, P. S.; Chiu, Y.

    2015-12-01

    In 1970's, the agriculture and aquaculture were rapidly developed at Pingtung coastal area in southern Taiwan. The groundwater aquifers were over-pumped and caused the seawater intrusion. In order to remedy the contaminated groundwater and find the best strategies of groundwater usage, a management model to search the optimal groundwater operational strategies is developed in this study. The objective function is to minimize the total amount of injection water and a set of constraints are applied to ensure the groundwater levels and concentrations are satisfied. A three-dimension density-dependent flow and transport simulation model, called SEAWAT developed by U.S. Geological Survey, is selected to simulate the phenomenon of seawater intrusion. The simulation model is well calibrated by the field measurements and replaced by the surrogate model of trained artificial neural networks (ANNs) to reduce the computational time. The ANNs are embedded in the management model to link the simulation and optimization models, and the global optimizer of differential evolution (DE) is applied for solving the management model. The optimal results show that the fully trained ANNs could substitute the original simulation model and reduce much computational time. Under appropriate setting of objective function and constraints, DE can find the optimal injection rates at predefined barriers. The concentrations at the target locations could decrease more than 50 percent within the planning horizon of 20 years. Keywords : Seawater intrusion, groundwater management, numerical model, artificial neural networks, differential evolution

  2. Seawater desalination plant using nuclear heating reactor coupled with MED process

    International Nuclear Information System (INIS)

    Wu Shaorong; Dong Duo; Zhang Dafang; Wang Xiuzhen

    2000-01-01

    A small size plant for seawater desalination using nuclear heating reactor coupled with MED process was developed by the Institute of Nuclear Energy Technology, Tsinghua University, China. this seawater desalination plant was designed to supply potable water demand to some coastal location or island where both fresh water and energy source are severely lacking. It is also recommended as a demonstration and training facility for seawater desalination using nuclear energy. The design of small size of seawater desalination plant couples two proven technologies: Nuclear Heating Reactor (NHR) and Multi-Effect Destination (MED) process. The NHR design possesses intrinsic and passive safety features, which was demonstrated by the experiences of the project NHR-5. the intermediate circuit and steam circuit were designed as the safety barriers between the NHR reactor and MED desalination system. Within 10-200 MWt of the power range of the heating reactor, the desalination plant could provide 8000 to 150,000 m 3 /d of high quality potable water. The design concept and parameters, safety features and coupling scheme are presented

  3. Mutually consistent thermodynamic potentials for fluid water, ice and seawater: a new standard for oceanography

    Czech Academy of Sciences Publication Activity Database

    Feistel, R.; Wright, D.G.; Miyagawa, K.; Harvey, A.H.; Hrubý, Jan; Jackett, D.R.; McDougall, T.J.; Wagner, W.

    2008-01-01

    Roč. 4, č. 4 (2008), s. 275-291 ISSN 1812-0784 Institutional research plan: CEZ:AV0Z20760514 Keywords : seawater * equation of state * metastable states Subject RIV: BJ - Thermodynamics www.ocean-sci.net/4/275/2008

  4. A methodological framework to assess the environmental and economic effects of injection barriers against seawater intrusion.

    Science.gov (United States)

    Siarkos, Ilias; Latinopoulos, Dionysis; Mallios, Zisis; Latinopoulos, Pericles

    2017-05-15

    Seawater intrusion is responsible for the progressive deterioration of groundwater quality in numerous coastal aquifers worldwide. As a consequence, seawater intrusion may constitute a serious threat to local groundwater resources, as well as to the regional economy of coastal areas. To alleviate these negative effects, a number of well-designed protective measures could be implemented. The implementation of these measures is usually associated with significant benefits for the environment and the local economy. In this perspective, the present study investigates the particular case of constructing injection barriers for controlling seawater intrusion by developing a methodological framework that combines numerical modeling with spatial and cost-benefit analyses. To this task, we introduce a novel approach, which considers the socio-economic aspects of seawater intrusion in the modeling procedure, and at the same time focuses on the spatial and temporal relationships between water salinity and farmers' income. To test the proposed methodology two alternative artificial recharge scenarios - with different volumes of water used for injection - are assessed. According to the results of this analysis, both scenarios are likely to have a positive impact on groundwater quality, as well as, a net economic benefit to local society. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Fluorogenic membrane overlays to enumerate total coliforms, Escherichia coli, and total Vibrionaceae in shellfish and seawater

    Science.gov (United States)

    Three assays were developed to enumerate total coliforms, Escherichia coli, and total Vibrionaceae in shellfish and other foods and in seawater and other environmental samples. Assays involve membrane overlays of overnight colonies on non-selective agar plates to detect ß-glucuronidase and lysyl am...

  6. Assessment of Selected Heavy Metals in Seawater and Sediment at Klang Coastal Area Malaysia

    International Nuclear Information System (INIS)

    Noor Aziatul Aini Hamzan; Farah Fardiana Mohamad Zaini; Mohd Ismail Ibrahim; Nik Azlin Nik Ariffin

    2015-01-01

    Sediments are capable of transporting loads of adsorbed nutrients, pesticides, heavy metals, and other toxins. In this study, the samples of sediment were collected from four sampling points (Kapar, Sungai Puloh, Sementa and North Port) using sediment core sampler. The cores then was sub-sampled by slicing into 1 cm slices and dried at 60 degree Celsius until mass become constant and the weight recorded. The samples were pulverized and sieved through 220 μm stainless steel sieves. Each sub-sample digested using aqua regia acids. For seawater, the samples were evaporated using the hotplate at 60 degree Celsius. The concentration of heavy metals was determined by inductively coupled plasma optical emission spectrometry (ICP-OES). The highest concentration of copper, zinc, iron and lead was observed from seawater samples obtained from Sementa while highest concentration of cadmium was found from Kapar samples). Most of the bottom seawater gives high concentration of the heavy metal compare to the surface. For sediment, the overall concentration of heavy metal in each layer was fluctuated. From the analysis, there is a significant correlation for overall selected heavy metals and the samples (seawater and sediment) that study in this area. (author)

  7. Rapid determination of radium-224/226 in seawater sample by alpha spectrometry.

    Science.gov (United States)

    Song, Lijuan; Yang, Yonggang; Luo, Maoyi; Ma, Yan; Dai, Xiongxin

    2017-05-01

    A new radiochemical separation method has been developed for rapid determination of alpha-emitting radium isotopes in seawater samples. This method can be applied for the measurement of 226 Ra in seawater samples when 224 Ra is used as tracer for chemical recovery correction. Likewise, 226 Ra can also be added as tracer for the determination of 224 Ra in seawater sample. In the method, radium is first pre-concentrated with hydrous titanium oxide (HTiO) and is purified by combined anion/cation exchange column chromatographic separation. The radium in the eluate is then co-precipitated with HTiO, dissolved in 9 M H 2 SO 4 , and followed through a BaSO 4 micro-precipitation step to prepare a thin-layer counting source to determine the activities of 224 Ra/ 226 Ra by alpha spectrometry. Replicate spike and blank samples were measured to evaluate the performance of the procedure. The minimum detectable activity concentration was determined to be 0.5 mBq·L -1 for 226 Ra and 0.4 mBq·L -1 for 224 Ra in 1 L of seawater sample with a counting time of 48 h. The method is a promising candidate for rapid measurement for alpha-emitting Ra isotopes in a large population of environment water samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Design Criteria, Operating Conditions, and Nickel-Iron Hydroxide Catalyst Materials for Selective Seawater Electrolysis.

    Science.gov (United States)

    Dionigi, Fabio; Reier, Tobias; Pawolek, Zarina; Gliech, Manuel; Strasser, Peter

    2016-05-10

    Seawater is an abundant water resource on our planet and its direct electrolysis has the advantage that it would not compete with activities demanding fresh water. Oxygen selectivity is challenging when performing seawater electrolysis owing to competing chloride oxidation reactions. In this work we propose a design criterion based on thermodynamic and kinetic considerations that identifies alkaline conditions as preferable to obtain high selectivity for the oxygen evolution reaction. The criterion states that catalysts sustaining the desired operating current with an overpotential seawater-mimicking electrolyte. The catalyst was synthesized by a solvothermal method and the activity, surface redox chemistry, and stability were tested electrochemically in alkaline and near-neutral conditions (borate buffer at pH 9.2) and under both fresh seawater conditions. The Tafel slope at low current densities is not influenced by pH or presence of chloride. On the other hand, the addition of chloride ions has an influence in the temporal evolution of the nickel reduction peak and on both the activity and stability at high current densities at pH 9.2. Faradaic efficiency close to 100 % under the operating conditions predicted by our design criteria was proven using in situ electrochemical mass spectrometry. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Meta-Cresol Purple Reference Material® (RM) for Seawater pH Measurements

    Science.gov (United States)

    Easley, R. A.; Waters, J. F.; Place, B. J.; Pratt, K. W.

    2016-02-01

    The pH of seawater is a fundamental quantity that governs the carbon dioxide - carbonate system in the world's oceans. High quality pH measurements for long-term monitoring, shipboard studies, and shorter-term biological studies (mesocosm and field experiments) can be ensured through a reference material (RM) that is compatible with existing procedures and which is traceable to primary pH measurement metrology. High-precision spectrophotometric measurements of seawater pH using an indicator dye such as meta-cresol purple (mCP) are well established. However, traceability of these measurements to the International System of Units (SI) additionally requires characterizing the spectrophotometric pH response of the dye in multiple artificial seawater buffers that themselves are benchmarked via primary pH (Harned cell) measurements at a range of pH, salinity, and temperature. NIST is currently developing such a mCP pH RM using this approach. This material will also incorporate new procedures developed at NIST for assessing the purity and homogeneity of the mCP reagent itself. The resulting mCP will provide long-term (years) stability and ease of shipment compared to artificial seawater pH buffers. These efforts will provide the oceanographic user community with a NIST issued mCP (RM), characterized as to its molar absorptivity values and acid dissociation constants (pKa), with uncertainties that comply with the Guide to the Expression of Uncertainty in Measurement (GUM).

  10. Memstill® - Low cost membrane distillation technology for seawater desalination

    NARCIS (Netherlands)

    Hanemaaijer, J.H.

    2004-01-01

    Despite widespread research and development efforts during the last 25 years, membrane distillation still is not an accepted process for seawater desalination. A consortium of nine parties is presently developing a modified air gap membrane distillation (AGMD) process, aiming at presenting a

  11. Experiences of corrosion and corrosion protection in seawater systems in the Nordic countries

    International Nuclear Information System (INIS)

    Henrikson, S.

    1985-01-01

    A summary is given of the experience of the corrosion resistance of pumps, heat exchangers, valves and pipings in different seawater cooling systems in Scandinavia, including power reactor cooling systems in Finland and Sweden. For pumps and heat exchangers the experience has been so extensive that a clear picture of today's standing can be given. Owing to scanty data concerning valves and pipes, the survey of the corrosion in these components is less well supported. Vertically extended centrifugal pumps are the pumps in general use in power plant cooling systems. To counteract corrosion on pump riser and pump casing having an organic surface coating, and on stainless steel shafts and impellers, these components should be provided with internal and external cathodic protection. For tube and plate type heat exchangers, titanium has proved to be the best material choice. Rubber-enclosed carbon steel pipings, or pipings having a thick coating of epoxy plastic, have shown very strong corrosion resistance in power plant seawater cooling systems. Valves in seawater systems have primarily been affected by corrosion due to poorly executed or damaged organic coating on cast iron. Different seawater-resistant bronzes (red bronze, tin bronze and aluminium bronze) are therefore preferable as valve materials

  12. Corrosion of low alloy steels in natural seawater. Influence of alloying elements and bacteria

    International Nuclear Information System (INIS)

    Dajoux Malard, Emilie

    2006-01-01

    Metallic infrastructures immersed in natural seawater are exposed to important corrosion phenomena, sometimes characterised as microbiologically influenced corrosion. The presence of alloying elements in low alloy steels could present a corrosion resistance improvement of the structures. In this context, tests are performed with commercial steel grades, from 0,05 wt pc Cr to 11,5 wt pc Cr. They consist in 'on site' immersion in natural seawater on the one hand, and in laboratory tests with immersion in media enriched with marine sulphide-producing bacteria on the other hand. Gravimetric, microbiological, electrochemical measurements and corrosion product analyses are carried out and show that corrosion phenomenon is composed of several stages. A preliminary step is the reduction of the corrosion kinetics and is correlated with the presence of sessile sulphide-producing bacteria and an important formation of sulphur-containing species. This phase is shorter when the alloying element content of the steel increases. This phase is probably followed by an increase of corrosion, appearing clearly after an 8-month immersion in natural seawater for some of the grade steels. Chromium and molybdenum show at the same time a beneficial influence to generalised corrosion resistance and a toxic effect on sulphide-producing bacteria. This multidisciplinary study reflects the complexity of the interactions between bacteria and steels; sulphide-producing bacteria seem to be involved in corrosion processes in natural seawater and complementary studies would have to clarify occurring mechanisms. (author) [fr

  13. Cathodic delamination of seawater-immersed anticorrosive coatings: Mapping of parameters affecting the rate

    DEFF Research Database (Denmark)

    Sørensen, Per Aggerholm; Dam-Johansen, Kim; Weinell, C. E.

    2010-01-01

    Abstract: Cathodic delamination is one of the major modes of failure for organic coatings immersed in seawater and refers to the weakening or loss of adhesion between the coating and the substrate. The diminished adhesion is the result of electrochemical reactions occurring at the coating...

  14. Effect of organic on chemical oxidation for biofouling control in pilot-scale seawater cooling towers

    KAUST Repository

    Al-Bloushi, Mohammed; Saththasivam, Jayaprakash; Jeong, Sanghyun; Amy, Gary L.; Leiknes, TorOve

    2017-01-01

    Due to the scarcity of potable water in many regions of the world, the demand for seawater as an alternative evaporative cooling medium in cooling towers (CTs) has increased significantly in recent years. Seawater make-up in CTs is deemed the most feasible because of its unlimited supply in the coastal areas of Gulf and Red Sea. However, the seawater CTs have higher challenges greatly mitigating their performances because it is an open system where biofouling and bio-corrosion occurring within the fillers and piping of recirculation systems. Their pilot-scale CTs were constructed to assess the performance of three types of oxidizing biocides or oxidants, namely chlorine, chlorine dioxide (ClO2) and ozone, for biofouling control. The test results showed that the addition of organic (5mg/L of methanol (MeOH)) increased the bacterial growth in CT basin. All oxidants were effective in keeping the microbial growth to the minimum. Oxidation increased the oxidation-reduction potential (ORP) level from 270 to 600mV. Total residual oxidant (TRO) was increased with oxidation but it was slightly increased with organic addition. Other parameters including pH, dissolved oxygen (DO), conductivity levels were not changed. However, higher formation of disinfection by-products (DBPs) was detected with chlorination and ozonation. This indicates the organic level should be limited in the oxidation for biofouling control in seawater CTs.

  15. Determination of Vanadium Binding Mode on Seawater-Contacted Polyamidoxime Adsorbents

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhicheng [Lawrence Berkeley National Laboratory (LBNL); Rao, Linfeng [Lawrence Berkeley National Laboratory (LBNL); Abney, Carter W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bryantsev, Vyacheslav [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ivanov, Aleksandr [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-09-01

    Adsorbents developed for the recovery of uranium from seawater display poor selectivity over other transition metals present in the ocean, with vanadium particularly problematic. To improve selectivity, an indispensable step is the positive identification of metal binding environments following actual seawater deployment. In this work we apply x-ray absorption fine structure (XAFS) spectroscopy to directly investigate the vanadium binding environment on seawater-deployed polyamidoxime adsorbents. Comparison of the x-ray absorption near edge spectra (XANES) reveal marked similarities to recently a reported non-oxido vanadium (V) structure formed upon binding with cyclic imidedioxime, a byproduct of generating amidoxime functionalities. Density functional theory (DFT) calculations provided a series of putative vanadium binding environments for both vanadium (IV) and vanadium (V) oxidation states, and with both amidoxime and cyclic imidedioxime. Fits of the extended XAFS (EXAFS) data confirmed vanadium (V) is bound exclusively by the cyclic imidedioxime moiety in a 1:2 metal:ligand fashion, though a modest structural distortion is also observed compared to crystal structure data and computationally optimized geometries which is attributed to morphology effects from the polymer graft chain and the absence of crystal packing interactions. These results demonstrate that improved selectivity for uranium over vanadium can be achieved by suppressing the formation of cyclic imidedioxime during preparation of polyamidoxime adsorbents for seawater uranium recovery.

  16. Speciation analysis of 129I in seawater using coprecipitation and accelerator mass spectrometry and its applications

    DEFF Research Database (Denmark)

    Xing, Shan; Hou, Xiaolin; Aldahan, Ala

    2017-01-01

    Speciation analysis of long-lived 129I in seawater can provide useful information on the source of water masses. This paper presents an improved method for speciation analysis of 129I based on coprecipitation of iodide as AgI with Ag2SO3 and AgCl. By adding a small amount of 127I carrier...

  17. Manganese in the shell of the bivalve Mytilus edulis: Seawater Mn or physiological control?

    Science.gov (United States)

    Freitas, Pedro S.; Clarke, Leon J.; Kennedy, Hilary; Richardson, Christopher A.

    2016-12-01

    Manganese in the shell calcite of marine bivalves has been suggested to reflect ambient seawater Mn concentrations, thus providing a high-resolution archive of past seawater Mn concentrations. However, a quantitative relationship between seawater Mn and shell Mn/Ca ratios, as well as clear understanding of which process(es) control(s) shell Mn/Ca, are still lacking. Blue mussels, Mytilus edulis, were grown in a one-year duration field experiment in the Menai Strait, U.K., to study the relationship between seawater particulate and dissolved Mn2+ concentrations and shell calcite Mn/Ca ratios. Shell Mn/Ca showed a well-defined intra-annual double-peak, with maximum values during early spring and early summer and low values during autumn and winter. Seawater particulate Mn peaked during winter and autumn, with a series of smaller peaks during spring and summer, whereas dissolved Mn2+ exhibited a marked single maximum during late-spring to early-summer, being low during the remainder of the year. Consequently, neither seawater particulate Mn nor dissolved Mn2+ concentrations explain the intra-annual variation of shell Mn/Ca ratios. A physiological control on shell Mn/Ca ratios is evident from the strong similarity and timing of the double-peaked intra-annual variations of Mn/Ca and shell growth rate (SGR), the latter corresponding to periods of increased metabolic activity (as indicated by respiration rate). It is thus likely that in M. edulis SGR influences shell Mn/Ca by altering the concentration or activity of Mn2+ within the extra-pallial fluid (EPF), by changing the flux of Mn into or the proportion of protein bound Mn within the EPF. By linking shell Mn/Ca ratios to the endogenous and environmental factors that determine growth and metabolic activity, this study helps to explain the lack of a consistent relationship between shell Mn/Ca in marine bivalve shell calcite and seawater particulate and dissolved Mn2+ concentrations. The use of Mn content from M. edulis

  18. Solar irradiance limits the long-term survival of Listeria monocytogenes in seawater.

    Science.gov (United States)

    NicAogáin, K; Magill, D; O'Donoghue, B; Conneely, A; Bennett, C; O'Byrne, C P

    2018-03-01

    Seafood has often been implicated in outbreaks of food-borne illness caused by Listeria monocytogenes but the source of contamination is usually not known. In this study we investigated the possibility that this pathogen could survive in seawater for an extended time period. Freshly collected seawater samples were inoculated with 1 × 10 8  CFU per ml of L. monocytogenes EGD-e and survival was monitored by plate counting for up to 25 days. When incubated in the dark, either at ambient temperatures (4-14°C) or at 16°C, >10 4  CFU per ml survivors were present after 25 days. However, when the seawater cell suspensions were exposed to ambient light (solar irradiation) and temperatures, L. monocytogenes lost viability rapidly and no survivors could be detected after the 80 h time point. Both UV-A and visible light in the blue region of the spectrum (470 nm) were found to contribute to this effect. The stress inducible sigma factor σ B was found to play a role in survival of L. monocytogenes in seawater. Together these data demonstrate that solar irradiation is a critical determinant of L. monocytogenes survival in marine environments. The data further suggest the possibility of controlling this food-borne pathogen in food-processing environments using visible light. Listeria monocytogenes is a food-borne bacterial pathogen capable of causing the life-threatening infection, listeriosis. In seafood the route of contamination from the environment is often not well understood as this pathogen is not generally thought to survive well in seawater. Here we provide evidence that L. monocytogenes is capable of surviving for long periods of time in seawater when light is excluded. Sunlight is demonstrated to have a significant effect on the survival of this pathogen in seawater, and both visible (470 nm) and UV-A light are shown to contribute to this effect. © 2017 The Society for Applied Microbiology.

  19. High-precision measurements of seawater Pb isotope compositions by double spike thermal ionization mass spectrometry.

    Science.gov (United States)

    Paul, Maxence; Bridgestock, Luke; Rehkämper, Mark; van DeFlierdt, Tina; Weiss, Dominik

    2015-03-10

    A new method for the determination of seawater Pb isotope compositions and concentrations was developed, which combines and optimizes previously published protocols for the separation and isotopic analysis of this element. For isotopic analysis, the procedure involves initial separation of Pb from 1 to 2L of seawater by co-precipitation with Mg hydroxide and further purification by a two stage anion exchange procedure. The Pb isotope measurements are subsequently carried out by thermal ionization mass spectrometry using a (207)Pb-(204)Pb double spike for correction of instrumental mass fractionation. These methods are associated with a total procedural Pb blank of 28±21 pg (1sd) and typical Pb recoveries of 40-60%. The Pb concentrations are determined by isotope dilution (ID) on 50 mL of seawater, using a simplified version of above methods. Analyses of multiple aliquots of six seawater samples yield a reproducibility of about ±1 to ±10% (1sd) for Pb concentrations of between 7 and 50 pmol/kg, where precision was primarily limited by the uncertainty of the blank correction (12±4 pg; 1sd). For the Pb isotope analyses, typical reproducibilities (±2sd) of 700-1500 ppm and 1000-2000 ppm were achieved for (207)Pb/(206)Pb, (208)Pb/(206)Pb and (206)Pb/(204)Pb, (207)Pb/(204)Pb, (208)Pb/(204)Pb, respectively. These results are superior to literature data that were obtained using plasma source mass spectrometry and they are at least a factor of five more precise for ratios involving the minor (204)Pb isotope. Both Pb concentration and isotope data, furthermore, show good agreement with published results for two seawater intercomparison samples of the GEOTRACES program. Finally, the new methods were applied to a seawater depth profile from the eastern South Atlantic. Both Pb contents and isotope compositions display a smooth evolution with depth, and no obvious outliers. Compared to previous Pb isotope data for seawater, the (206)Pb/(204)Pb ratios are well correlated

  20. Physiological responses of coccolithophores to abrupt exposure of naturally low pH deep seawater.

    Science.gov (United States)

    Iglesias-Rodriguez, Maria Debora; Jones, Bethan M; Blanco-Ameijeiras, Sonia; Greaves, Mervyn; Huete-Ortega, Maria; Lebrato, Mario

    2017-01-01

    Upwelling is the process by which deep, cold, relatively high-CO2, nutrient-rich seawater rises to the sunlit surface of the ocean. This seasonal process has fueled geoengineering initiatives to fertilize the surface ocean with deep seawater to enhance productivity and thus promote the drawdown of CO2. Coccolithophores, which inhabit many upwelling regions naturally 'fertilized' by deep seawater, have been investigated in the laboratory in the context of ocean acidification to determine the extent to which nutrients and CO2 impact their physiology, but few data exist in the field except from mesocosms. Here, we used the Porcupine Abyssal Plain (north Atlantic Ocean) Observatory to retrieve seawater from depths with elevated CO2 and nutrients, mimicking geoengineering approaches. We tested the effects of abrupt natural deep seawater fertilization on the physiology and biogeochemistry of two strains of Emiliania huxleyi of known physiology. None of the strains tested underwent cell divisions when incubated in waters obtained from seawater from ~1,000 m (pH = 7.9; CO2 ~560 p.p.m.; 14-17 μM nitrate) and ~4,800 m (pH = 7.9; CO2 ~600 p.p.m.; 21 μM nitrate). Emiliania huxleyi strain CCMP 88E showed no differences in growth rate or in cellular content or production rates of particulate organic (POC) and inorganic (PIC) carbon and cellular particulate organic nitrogen (PON) between treatments using water from 1,000 m and 4,800 m. However, despite the N:P ratio of seawater being comparable in water from ~1,000 and ~4,800 m, the PON production rates were three times lower in one incubation using water from ~1,000 m compared to values observed in water from ~4,800 m. Thus, the POC:PON ratios were threefold higher in cells that were incubated in ~1,000 m seawater. The heavily calcified strain NZEH exhibited lower growth rates and PIC production rates when incubated in water from ~4,800 m compared to ~1,000 m, while cellular PIC, POC and PON were higher in water from 4,800 m