WorldWideScience

Sample records for solar salt ponds

  1. Microbiology of solar salt ponds

    Science.gov (United States)

    Javor, B.

    1985-01-01

    Solar salt ponds are shallow ponds of brines that range in salinity from that of normal seawater (3.4 percent) through NaCl saturation. Some salterns evaporate brines to the potash stage of concentration (bitterns). All the brines (except the bitterns, which are devoid of life) harbor high concentrations of microorganisms. The high concentrations of microorganisms and their adaptation to life in the salt pond are discussed.

  2. EXPERIMENTAL INVESTIGATION OF HEAT STORAGE CHARACTERISTIC OF UREA AND BORAX SALT GRADIENT SOLAR PONDS

    Directory of Open Access Journals (Sweden)

    Hüseyin KURT

    2006-03-01

    Full Text Available Salt gradient solar ponds are simple and low cost solar energy system for collecting and storing solar energy. In this study, heat storage characteristic of urea and borax solutions in the solar pond were examined experimentally. Establishing density gradients in different concentration, variations in the temperature and density profiles were observed in four different experiments. Maximum storage temperatures were measured as 28ºC and 36 ºC for the ponds with urea and borax solution, respectively. The temperature difference between the bottom and the surface of the pond were measured as 13 ºC for urea and 17 ºC for borax- solutions. According to these results, heat storage characteristic of the solar pond with borax solution was found to be better than urea solution.

  3. Performance investigation of a salt gradient solar pond coupled with desalination facility near the Dead Sea

    International Nuclear Information System (INIS)

    Saleh, A.; Qudeiri, J.A.; Al-Nimr, M.A.

    2011-01-01

    Solar ponds provide the most convenient and least expensive option for heat storage for daily and seasonal cycles. This is particularly important for a desalination facility, if steady and constant water production is required. If, in addition to high storage capacity, other favorable conditions exist, the salt gradient solar ponds (SGSPs) are expected to be able to carry the entire load of a large-scale flash desalination plants without dependence upon supplementary sources. This paper presents a performance investigation of a SGSP coupled with desalination plant under Jordanian climatic conditions. This is particularly convenient in the Dead Sea region characterized by high solar radiation intensities, high ambient temperature most of the year, and by the availability of high concentration brine. It was found that a 3000 m 2 solar pond installed near the Dead Sea is able to provide an annual average production rate of 4.3 L min -1 distilled water compared with 3.3 L min -1 that would be produced by El Paso solar pond, which has the same surface area. Based on this study, solar ponds appear to be a feasible and an appropriate technology for water desalination near the Dead Sea in Jordan. -- Research highlights: → A performance investigation of a solar pond coupled with desalination plant. → Dead Sea area is characterized by availability of high solar radiation and brine. → The Dead Sea solar pond can provide production rate of 4.3 L min -1 . → El Paso solar pond has production rate of 3.32 L min -1 . The improvement is about 30%. → The solar pond with desalination investigated showed to be a feasible technology.

  4. A comparison between evaporation ponds and evaporation surfaces as a source of the concentrated salt brine for salt gradient maintenance at Tajoura solar pond

    International Nuclear Information System (INIS)

    Ramadan, Abdulghani M.; Agha, Khairy R.; Abughres, M.

    2012-01-01

    One of the main problems that negatively affect the operation of salt gradient solar ponds and influence its thermal stability is the maintenance of salt gradient profile. Evaporation pond (EP) is designed to generate the salt which lost upward salt diffusion from the lower convective zone (LCZ) of the solar pond. Another attractive method is the evaporation surface facility (ES). Regions with moderate to high precipitation favor Evaporation Surface over Evaporation Ponds. Dry climates will generally favor Evaporation Ponds for the brine re-concentration. In previous studies [1-3], the authors have shown that the (EP) of Tajoura's Experimental Solar Pond (TESP) is under sized and can provide only about 30% of the salt required by a Salt Gradient Solar Pond (SGSP). The anticipated size of (EP) was estimated and presented in those studies under different design conditions, including Summer, Autumn and Spring designs, while the winter design was excluded due to the low rates of net evaporation during the winter season. In addition, the results presented were predicted for the first three years of operation. The daily variations of brine concentration in the (EP) of (TESP) and those based on different designs were predicted and discussed under different scenarios. The quantities of brine provided by the evaporation pond and that required by SGSP were predicted for both cases of surface water flushing (fresh water and sea-water) under the different design conditions as shown in Table 1. This paper investigates the differences between (EP) and (ES) both as a source for salt brine generation by evaporation. The effect of (EP) depth on the area ratio and daily variations of salt concentrations for three years of operation is shown. Results show that evaporation can be a reasonable method for salt brine generation. Reducing the depth of (EP) improves the capability of (EP) for brine re-concentration. It also increases the (EP) surface area for the same quantity of

  5. Experimental and numerical analysis of sodium-carbonate salt gradient solar-pond performance under simulated solar-radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kurt, Hueseyin; Ozkaymak, Mehmet [Zonguldak Karaelmas University, Technical Education Faculty, 78200 Karabuk (Turkey); Binark, A. Korhan [Marmara University, Technical Education Faculty, 34722 Kuyubasi-Istanbul (Turkey)

    2006-04-01

    The objective of this study is to investigate experimentally and theoretically whether sodium carbonate (Na{sub 2}CO{sub 3}) salt is suitable for establishing a salinity gradient in a salt-gradient solar-pond (SGSP). For this purpose, a small-scale prismatic solar-pond was constructed. Experiments were conducted in the laboratory under the incident radiation from two halogen-lamps acting as a solar simulator. Furthermore, a one-dimensional transient mathematical model that describes the heat and mass transfer behaviour of the SGSP was developed. The differential equations obtained were solved numerically using a finite-difference method. It was found from the experiments that the density gradient, achieved using sodium carbonate salt, can suppress convection from the bottom to the surface of the pond. (author)

  6. Experimental and numerical analysis of sodium-carbonate salt gradient solar-pond performance under simulated solar-radiation

    International Nuclear Information System (INIS)

    Kurt, Hueseyin; Ozkaymak, Mehmet; Binark, A. Korhan

    2006-01-01

    The objective of this study is to investigate experimentally and theoretically whether sodium carbonate (Na 2 CO 3 ) salt is suitable for establishing a salinity gradient in a salt-gradient solar-pond (SGSP). For this purpose, a small-scale prismatic solar-pond was constructed. Experiments were conducted in the laboratory under the incident radiation from two halogen-lamps acting as a solar simulator. Furthermore, a one-dimensional transient mathematical model that describes the heat and mass transfer behaviour of the SGSP was developed. The differential equations obtained were solved numerically using a finite-difference method. It was found from the experiments that the density gradient, achieved using sodium carbonate salt, can suppress convection from the bottom to the surface of the pond

  7. Regional applicability and potential of salt-gradient solar ponds in the United States. Volume 2: Detailed report

    Science.gov (United States)

    Lin, E. I. H.

    1982-03-01

    A comprehensive assessment of the regional applicability and potential of salt-gradient solar ponds in the United States is provided. The assessment is focused on the general characteristics of twelve defined geographic regions. Natural resources essential to solar ponds are surveyed. Meteorological and hydrogeological conditions affecting pond performance are examined. Potentially favorable pond sites are identified. Regional thermal and electrical energy output from solar ponds is calculated. Selected pond design cases are studied. Five major potential market sectors are evaluated in terms of technical and energy-consumption characteristics, and solar-pond applicability and potential. Relevant pond system data and financial factors are analyzed. Solar-pond energy costs are compared with conventional energy costs. The assessment concludes that, excepting Alaska, ponds are applicable in all regions for at least two market sectors. Total solar pond energy supply potential in the five market sectors examined is estimated to be 8.94 quads/yr by the year 2000, approximately 7.2% of the projected total national energy demand.

  8. Combined effect of bottom reflectivity and water turbidity on steady state thermal efficiency of salt gradient solar pond

    International Nuclear Information System (INIS)

    Husain, M.; Patil, P.S.; Patil, S.R.; Samdarshi, S.K.

    2004-01-01

    In salt gradient solar ponds, the clarity of water and absorptivity of the bottom are important concerns. However, both are practically difficult to maintain beyond a certain limit. The reflectivity of the bottom causes the loss of a fraction of the incident radiation flux, resulting in lower absorption of flux in the pond. Turbidity hinders the propagation of radiation. Thereby it decreases the flux reaching the storage zone. Both these factors lower the efficiency of the pond significantly. However, the same turbidity also prevents the loss of radiation reflected from the bottom. Hence, the combined effect is compensatory to some extent. The present work is an analysis of the combined effect of the bottom's reflectivity and water turbidity on the steady state efficiency of solar ponds. It is found that in the case of a reflective bottom, turbidity, within certain limits, improves the efficiency of pond. This is apparently contradictory to the conventional beliefs about the pond. Nevertheless, this conclusion is of practical importance for design and maintenance of solar ponds

  9. A Two-Dimensional Numerical Study of Hydrodynamic, Heat and Mass Transfer and Stability in a Salt Gradient Solar Pond

    Directory of Open Access Journals (Sweden)

    Ali Ben Moussa

    2012-10-01

    Full Text Available In this work, the problem of hydrodynamic, heat and mass transfer and stability in a salt gradient solar pond has been numerically studied by means of computational fluid dynamics in transient regime. The body of the simulated pond is an enclosure of height H and length L wherein an artificial salinity gradient is created in order to suppress convective motions induced by solar radiation absorption and to stabilize the solar pond during the period of operation. Here we show the distribution of velocity, temperature and salt concentration fields during energy collection and storage in a solar pond filled with water and constituted by three different salinity zones. The bottom of the pond is blackened and the free-surface is subjected to heat losses by convection, evaporation and radiation while the vertical walls are adiabatic and impermeable. The governing equations of continuity, momentum, thermal energy and mass transfer are discretized by finite–volume method in transient regime. Velocity vector fields show the presence of thin convective cells in the upper convective zone (UCZ and large convective cells in the lower convective zone (LCZ. This study shows the importance of buoyancy ratio in the decrease of temperature in the UCZ and in the preservation of high temperature in the LCZ. It shows also the importance of the thickness of Non-Convective Zone (NCZ in the reduction of the upwards heat losses.

  10. Halite depositional facies in a solar salt pond: A key to interpreting physical energy and water depth in ancient deposits?

    Science.gov (United States)

    Robertson Handford, C.

    1990-08-01

    Subaqueous deposits of aragonite, gypsum, and halite are accumulating in shallow solar salt ponds constructed in the Pekelmeer, a sea-level sauna on Bonaire, Netherlands Antilles. Several halite facies are deposited in the crystallizer ponds in response to differences in water depth and wave energy. Cumulate halite, which originates as floating rafts, is present only along the protected, upwind margins of ponds where low-energy conditions foster their formation and preservation. Cornet crystals with peculiar mushroom- and mortarboard-shaped caps precipitate in centimetre-deep brine sheets within a couple of metres of the upwind or low-energy margins. Downwind from these margins, cornet and chevron halite precipitate on the pond floors in water depths ranging from a few centimetres to ˜60 cm. Halite pisoids with radial-concentric structure are precipitated in the swash zone along downwind high-energy shorelines where they form pebbly beaches. This study suggests that primary halite facies are energy and/or depth dependent and that some primary features, if preserved in ancient halite deposits, can be used to infer physical energy conditions, subenvironments such as low- to high-energy shorelines, and extremely shallow water depths in ancient evaporite basins.

  11. Solar pond conception - experimental and theoretical studies

    Energy Technology Data Exchange (ETDEWEB)

    Kurt, Huseyin [Zonguldak Karaelmas Univ., Technical Education Faculty, Karabuk (Turkey); Halici, Fethi [Sakarya Univ., Mechanical Engineering Dept., Adapazari (Turkey); Binark, A. Korhan [Marmara Univ., Technical Education Faculty, Istanbul (Turkey)

    2000-07-01

    A one dimensional transient mathematical model for predicting the thermal performance of the salt gradient solar pond is developed and presented. In this paper, the natural solar ponds and different artificial solar pond systems found in the literature are introduced. Necessary modifications are made on the experimental stand located in Istanbul Technical University, the experimental stand is introduced and natural phenomena produced in the pond by the different solar pond variations under natural conditions are observed. In the theoretical work based on a one dimensional unsteady state heat conduction model with internal heat generation, the energy and mass balance equations for the upper convective zone, the non-convective zone and the lower convective zone, all of which form the solar pond, are written in terms of differential equations. These equations are solved analytically and numerically. The results obtained from the analysis are compared with the experimental results. The temperature and the concentration profiles are separately presented in the figures. (Author)

  12. Solar pond design for Arabian Gulf conditions

    Energy Technology Data Exchange (ETDEWEB)

    Hassab, M.A.; Tag, I.A.; Jassim, I.A.; Al-Juburi, F.Y.

    1987-01-01

    Collection and storage of solar energy in salt gradient solar ponds under conditions of high ambient and ground temperatures and all year-round sunny weather are investigated theoretically. A transient model based on measured local environmental conditions is developed to predict solar transmission, temperature distribution and salt distribution inside the pond for any day of the year. In the model the effects of heat dissipation into the ground, bottom reflection, pond dimensions, load extraction and variation of the pond's physical properties with temperature and concentration are investigated. The generated non-linear coupled system of heat and salt concentration equations for the composite media, considered to have isothermal boundary conditions, is solved numerically using the implicit finite-difference scheme.

  13. Calculation of heat balance considering the reflection, refraction of incident ray and salt diffusion on solar pad; Hikari no hansha kussetsu oyobi shio no kakusan wo koryoshita solar pond no netsukeisan

    Energy Technology Data Exchange (ETDEWEB)

    Kanayama, K; Li, X; Baba, H; Endo, N [Kitami Institute of Technology, (Japan)

    1997-11-25

    In calculating heat balance of solar pond, calculation was made considering things except quality of the incident ray and physical properties of pond water which were conventionally considered. The real optical path length was determined from the reflection ratio of ray on the water surface based on the refraction ratio of pond water and the locus of water transmitted ray in order to calculate a total transmission rate. The rate of absorption of monochromatic lights composing of solar light in their going through the media is different by wavelength, and therefore, calculation was made in each monochromatic light. As to four kinds of salt water solution, NaCl, KCl, MgCl2 and CaCl2, these phenomena seen in solar pond are taken in, and a total transmission rate based on reality can be calculated by the wavelength integration method. Moreover, in the salt gradient layer, there are gradients in both concentration and temperature, and thermal physical values of each layer change. Accordingly, mass transfer and thermal transfer by both gradients were considered at the same time. An analytic solution was introduced which analyzes salt diffusion in the temperature field in the gradient layer and determines the concentration distribution. By these, concentration and physical values of each layer were calculated according to phenomena, and thermal balance of each layer of the solar pond was able to be accurately calculated. 6 refs., 5 figs., 2 tabs.

  14. South Bay Salt Pond Mercury Studies Project

    Science.gov (United States)

    Information about the SFBWQP South Bay Salt Pond Mercury Studies Project, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

  15. A theoretical study of a direct contact membrane distillation system coupled to a salt-gradient solar pond for terminal lakes reclamation.

    Science.gov (United States)

    Suárez, Francisco; Tyler, Scott W; Childress, Amy E

    2010-08-01

    Terminal lakes are water bodies that are located in closed watersheds with the only output of water occurring through evaporation or infiltration. The majority of these lakes, which are commonly located in the desert and influenced by human activities, are increasing in salinity. Treatment options are limited, due to energy costs, and many of these lakes provide an excellent opportunity to test solar-powered desalination systems. This paper theoretically investigates utilization of direct contact membrane distillation (DCMD) coupled to a salt-gradient solar pond (SGSP) for sustainable freshwater production at terminal lakes. A model for heat and mass transport in the DCMD module and a thermal model for an SGSP were developed and coupled to evaluate the feasibility of freshwater production. The construction of an SGSP outside and inside of a terminal lake was studied. As results showed that freshwater flows are on the same order of magnitude as evaporation, these systems will only be successful if the SGSP is constructed inside the terminal lake so that there is little or no net increase in surface area. For the study site of this investigation, water production on the order of 2.7 x 10(-3) m(3) d(-1) per m(2) of SGSP is possible. The major advantages of this system are that renewable thermal energy is used so that little electrical energy is required, the coupled system requires low maintenance, and the terminal lake provides a source of salts to create the stratification in the SGSP. (c) 2010 Elsevier Ltd. All rights reserved.

  16. South Bay Salt Pond Tidal Marsh Restoration at Pond A17 Project

    Science.gov (United States)

    Information about the SFBWQP South Bay Salt Pond Tidal Marsh Restoration at Pond A17 Project, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

  17. Observations of the transmittance in two solar ponds

    Energy Technology Data Exchange (ETDEWEB)

    Almanza, R.; Bryant, M.C.

    1983-11-01

    A NaCl salt gradient solar pond has been in continuous operation at the University of New Mexico since the fall of 1975; a smaller pond, using KNO/sub 3/ to produce the salinity gradient, was commissioned in the fall of 1981. The distribution of absorbed radiation in the ponds is of key importance in the determination of their efficiencies for collecting and storing solar energy. The absorption coefficient of light in an aqueous solution is very dependent upon wavelength; the spectral distribution of sunlight shifts toward the blue and the amount of solar energy absorbed per unit length of path declines with depth of penetration. The presence of suspended solids and bioforms further complicate the transmittance of sun light through the pond, specially since this contamination tends to vary strongly with depth. Because of its importance to the phytoplankton population , considerable work has been done by oceanographers on the absorption and scattering of light for different wavelengths. However, in a solar pond the big question is the amount of energy reaching the lower convective layer (storage). Several attempts have been made to measure the transmittance in solar ponds, mainly NaCl but the problem is to find a temperature-insensitive submersible pyranometer. Convenient formulas have been offered for the attenuation of solar radiation in pond water by considering it to be divided into spectral bands, or by fitting simple analytical functions, or specifying the extintion coefficient. (For the first method, it is necessary to know the absorption and scattering of light for different lambda.) In this paper some measurements of transmittance in the UNM ponds, are presented thereby exhibiting a simple procedure which may be of interest to others in this field.

  18. Solar pond for heating anaerobic digesters

    International Nuclear Information System (INIS)

    Song Kehui; Li Shensheng

    1991-10-01

    A theoretical analysis and numerical results calculated for solar pond heating anaerobic digesters in Beijing area in China are presented. The effect of temperature rise is evident and rather steady. 3 refs, 1 fig., 1 tab

  19. South Bay Salt Pond Tidal Wetland Restoration Phase II Planning

    Science.gov (United States)

    Information about the SFBWQP South Bay Salt Pond Tidal Wetland Restoration Phase II Planning project, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic re

  20. South Bay Salt Pond Restoration, Phase II at Ravenswood

    Science.gov (United States)

    Information about the South Bay Salt Pond Restoration Project: Phase II Construction at Ravenswood, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

  1. Investigation of turbidity effect on exergetic performance of solar ponds

    International Nuclear Information System (INIS)

    Atiz, Ayhan; Bozkurt, Ismail; Karakilcik, Mehmet; Dincer, Ibrahim

    2014-01-01

    Highlights: • A comprehensive experimental work on a turbidity of the solar pond. • Percentage transmission evaluation of the turbid and clean salty water of the zones. • Exergy analysis of the inner zones for turbid and clean salty water. • Turbidity effect on exergy efficiencies of the solar pond. • The thermal performance assessment by comparing the exergetic efficiencies of the solar pond. - Abstract: The present paper undertakes a study on the exergetic performance assessment of a solar pond and experimental investigation of turbidity effect on the system performance. There are various types of solar energy applications including solar ponds. One of significant parameters to consider in the assessment of solar pond performance is turbidity which is caused by dirty over time (e.g., insects, leaf, dust and wind bringing parts fall down). Thus, the turbidity in the salty water decreases solar energy transmission through the zones. In this study, the samples are taken from the three zones of the solar pond and analyzed using a spectrometer for three months. The transmission aspects of the solar pond are investigated under calm and turbidity currents to help distinguish the efficiencies. Furthermore, the maximum exergy efficiencies are found to be 28.40% for the calm case and 22.27% with turbidity effects for the month of August, respectively. As a result, it is confirmed that the solar pond performance is greatly affected by the turbidity effect

  2. Solar Pond Potential as A New Renewable Energy in South Sulawesi

    Science.gov (United States)

    Fadliah Baso, Nur; Chaerah Gunadin, Indar; Yusran

    2018-03-01

    Renewable energy sources need to be developed to maintain the electric energy availability by utilizing oceanic energy, namely solar pond energy. This energy is highly influenced by several factors including salinity, air temperature and solar radiation. This study was focused on finding the potential of solar pond in South Sulawesi, a region with fairly high solar radiation and abundant salt water raw materials availability. The method used in this study was analyzing the values from the mathematic models of daily horizontal solar radiation, air temperature, wind speed, relative humidity and atmospheric pressure for the last 22 years which were finalized using MATLAB. The findings of this study will show the areas with good potentials to apply solar pond in South Sulawesi that can be utilized in various fields including power generator, industrial heating process, desalination and heating for biomass conversion.

  3. Road Salts as Environmental Constraints in Urban Pond Food Webs

    Science.gov (United States)

    Van Meter, Robin J.; Swan, Christopher M.

    2014-01-01

    Freshwater salinization is an emerging environmental filter in urban aquatic ecosystems that receive chloride road salt runoff from vast expanses of impervious surface cover. Our study was designed to evaluate the effects of chloride contamination on urban stormwater pond food webs through changes in zooplankton community composition as well as density and biomass of primary producers and consumers. From May – July 2009, we employed a 2×2×2 full-factorial design to manipulate chloride concentration (low = 177 mg L−1 Cl−/high = 1067 mg L−1 Cl−), gray treefrog (Hyla versicolor) tadpoles (presence/absence) and source of stormwater pond algae and zooplankton inoculum (low conductance/high conductance urban ponds) in 40, 600-L mesocosms. Road salt did serve as a constraint on zooplankton community structure, driving community divergence between the low and high chloride treatments. Phytoplankton biomass (chlorophyll [a] µg L−1) in the mesocosms was significantly greater for the high conductance inoculum (Psalts among algal resources and zooplankton taxa, and further suggest that road salts can act as a significant environmental constraint on urban stormwater pond communities. PMID:24587259

  4. Renewable water: Direct contact membrane distillation coupled with solar ponds

    International Nuclear Information System (INIS)

    Suárez, Francisco; Ruskowitz, Jeffrey A.; Tyler, Scott W.; Childress, Amy E.

    2015-01-01

    Highlights: • Experimental investigation of direct contact membrane distillation driven by solar ponds. • The DCMD/SGSP system treats ∼6 times the water flow treated by an AGMD/SGSP system. • Half of the energy extracted from the SGSP was used to transport water across the membrane. • Reducing heat losses through the DCMD/SGSP system would yield higher water fluxes. - Abstract: Desalination powered by renewable energy sources is an attractive solution to address the worldwide water-shortage problem without contributing significant to greenhouse gas emissions. A promising system for renewable energy desalination is the utilization of low-temperature direct contact membrane distillation (DCMD) driven by a thermal solar energy system, such as a salt-gradient solar pond (SGSP). This investigation presents the first experimental study of fresh water production in a coupled DCMD/SGSP system. The objectives of this work are to determine the experimental fresh water production rates and the energetic requirements of the different components of the system. From the laboratory results, it was found that the coupled DCMD/SGSP system treats approximately six times the water flow treated by a similar system that consisted of an air–gap membrane distillation unit driven by an SGSP. In terms of the energetic requirements, approximately 70% of the heat extracted from the SGSP was utilized to drive thermal desalination and the rest was lost in different locations of the system. In the membrane module, only half of the useful heat was actually used to transport water across the membrane and the remainder was lost by conduction in the membrane. It was also found that by reducing heat losses throughout the system would yield higher water fluxes, pointing out the need to improve the efficiency throughout the DCMD/SGSP coupled system. Therefore, further investigation of membrane properties, insulation of the system, or optimal design of the solar pond must be addressed in

  5. Heat recovery from ground below the solar pond

    NARCIS (Netherlands)

    Ganguly, S.; Date, Abhijit; Akbarzadeh, Aliakbar

    2017-01-01

    The method of heat recovery from the ground below solar ponds is investigated in the present brief note. Solar ponds lose considerable amount of heat from its bottom to the ground due to temperature gradient between them. This waste heat from ground, which is at different temperature at different

  6. The critical role of islands for waterbird breeding and foraging habitat in managed ponds of the South Bay Salt Pond Restoration Project, South San Francisco Bay, California

    Science.gov (United States)

    Ackerman, Joshua T.; Hartman, C. Alex; Herzog, Mark P.; Smith, Lacy M.; Moskal, Stacy M.; De La Cruz, Susan E. W.; Yee, Julie L.; Takekawa, John Y.

    2014-01-01

    The South Bay Salt Pond Restoration Project aims to restore 50–90 percent of former salt evaporation ponds into tidal marsh in South San Francisco Bay, California. However, large numbers of waterbirds use these ponds annually as nesting and foraging habitat. Islands within ponds are particularly important habitat for nesting, foraging, and roosting waterbirds. To maintain current waterbird populations, the South Bay Salt Pond Restoration Project plans to create new islands within former salt ponds in South San Francisco Bay. In a series of studies, we investigated pond and individual island attributes that are most beneficial to nesting, foraging, and roosting waterbirds.

  7. Mercury Cycling in Salt Marsh Pond Ecosystems: Cape Cod, MA

    Science.gov (United States)

    Ganguli, P. M.; Gonneea, M. E.; Lamborg, C. H.; Kroeger, K. D.; Swarr, G.; Vadman, K. J.; Baldwin, S.; Brooks, T. W.; Green, A.

    2014-12-01

    We are measuring total mercury (HgT) and monomethylmercury (CH3Hg+ or MMHg) in pore water, surface water, and sediment cores from two salt marsh pond systems on the south shore of Cape Cod, MA to characterize the distribution of mercury species and to identify features that influence mercury speciation and transport. Sage Lot Pond is relatively undisturbed and has low nitrogen loading (12 kg ha-1 y-1). It is part of the Waquoit Bay National Estuarine Reserve and is surrounded by undeveloped wooded uplands. In contrast, Great Pond is highly impacted. Nitrogen loading to the site is elevated (600 kg ha-1 y-1) and the marsh is adjacent to a large residential area. In both systems, a 1 to 2 m organic-rich peat layer overlies the permeable sand aquifer. Groundwater in this region is typically oxic, where pore water within salt marsh peat is suboxic to anoxic. We hypothesize that redox gradients at the transition from the root zone to peat and at the peat-sand interface may provide habitat for MMHg-producing anaerobic bacteria. Preliminary results from a 2-m nearshore depth profile at Sage Lot Pond indicate HgT in groundwater within the sand aquifer occurred primarily in the > 0.2 μm fraction, with unfiltered concentrations exceeding 100 pM. Filtered (fraction of filtered HgT in peat pore water. Although MMHg in both groundwater and pore water remained around 1 pM throughout our depth profile, we observed an increase in sediment MMHg (0.3 to 1.6 μg/kg) at the peat-sand interface. MMHg comprised ~50% of the HgT concentration in pore water suggesting mercury in the salt marsh peat is biologically available.

  8. EXPERIMENTAL INVESTIGATION OF SOLAR POND PERFORMANCE IN KARABUK ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Mehmet ÖZKAYMAK

    2004-01-01

    Full Text Available The solar energy, one of the alternative energy sources, can be economically and cheaply and efficiently collected with solar ponds. In this study, varying concentrations of sodium carbonate dilution in the solar pond in terms of heat storage performance has been examined. Experiment apparatus has been located Zonguldak Karaelmas University Karabük Technical Education Faculty. Five experiments with different density levels have been done and the changes in the temperature and density have been presented graphically within the solar pond. The experiments show that the temperature difference between the bottom and top level of solar pond is max. 21 °C and the highest temperature in lower convective zone (LCZ has been measured as 49 °C.

  9. Comparative productivity of distillation and reverse osmosis desalination using energy from solar ponds

    Energy Technology Data Exchange (ETDEWEB)

    Tleimat, B.W.; Howe, E.D.

    1982-11-01

    This paper presents comparative analyses of two methods for producing desalted water using the heat collected by a solar pond - the first by distillation, and the second by reverse osmosis. The distillation scheme uses a multiple-effect distiller supplied with steam generated in a flash boiler using heat from a solar pond. Solar pond water passes through a heat exchanger in the water system ahead of the flash boiler. The second scheme uses a similar arrangement to generate hydrocarbon vapor which drives a Rankine cycle engine. This engine produces mechanical/ electrical power for the RO plant. The analyses use two pond water temperatures -82.2/sup 0/C (180/sup 0/F) and 71.1/sup 0/C (160/sup 0/F) -- which seem to cover the range expected from salt-gradient ponds. In each case, the pond water temperature drops by 5.56/sup 0/C (10/sup 0/F) while passing through the vapor generator system. Results of these analyses show that, based on the assumptions made, desalted water could be produced by distillation at productivity rates much greater than those estimated for the RO plant.

  10. Comparative productivity of distillation and reverse osmosis desalination using energy from solar ponds

    Energy Technology Data Exchange (ETDEWEB)

    Tleimat, B.W.; Howe, E.D.

    1982-11-01

    This paper presents comparative analyses of two methods for producing desalted water using the heat collected by a solar pond - the first by distillation, and the second by reverse osmosis. The distillation scheme uses a multiple-effect distiller supplied with steam generated in a flash boiler using heat from a solar pond. Solar pond water passes through a heat exchanger in the water system ahead of the flash boiler. The second scheme uses a similar arrangement to generate hydrocarbon vapor which drives a Rankine cycle engine. This engine produces mechanical/ electrical power for the RO plant. The analyses use two pond water temperatures 82.2/sup 0/C (180/sup 0/F) and 71.1/sup 0/C (160/sup 0/F) - which seem to cover the range expected from salt-gradient ponds. In each case, the pond water temperature drops by 5.56/sup 0/C (10/sup 0/F) while passing through the vapor generator system. Results of these analyses show that, based on the assumptions made, desalted water could be produced by distillation at productivity rates much greater than those estimated for the RO plant.

  11. Heating an aquaculture pond with a solar pool blanket

    Energy Technology Data Exchange (ETDEWEB)

    Wisely, B; Holliday, J E; MacDonald, R E

    1982-01-01

    A floating solar blanket of laminated bubble plastic was used to heat a 0.11 ha seawater pond of 1.3 m depth. The covered pond maintained daily temperatures 6 to 9/sup 0/C above two controls. Local air temperatures averaged 14 to 19/sup 0/C. Oysters, prawns, seasquirts, and fish in the covered pond all survived. After three weeks, the blanket separated. This was the result of pond temperatures exceeding 30/sup 0/C, the maximum manufacturer's specification. Floating blankets fabricated to higher specifications would be useful for maintaining above-ambient temperatures in small ponds or tanks in temporary situations during cold winter months and might have a more permanent use.

  12. Avian communities in baylands and artificial salt evaporation ponds of the San Francisco Bay estuary

    Science.gov (United States)

    Takekawa, John Y.; Lu, C.T.; Pratt, R.T.

    2001-01-01

    San Francisco Bay wetlands, seasonal and tidal marshes between the historic low and high tide lines, are now highly fragmented because of development during the past 150 years. Artificial salt pond systems in the Bay are hypersaline and typically support simple assemblages of algae and invertebrates. In order to establish the value of salt ponds for migratory waterbirds, we used datasets to conduct a meta-analysis of avian communities in the baylands and salt ponds of San Pablo Bay. Fifty-three species of waterbirds in the salt ponds represented six foraging guilds: surface feeders, shallow probers, deep probers, dabblers, diving benthivores and piscivores. The total number of species and the Shannon-Weiner diversity index was higher in baylands than in salt ponds during all four seasons. However, overall bird density (number/ha) was higher in salt ponds compared with baylands in the winter and spring, primarily because of large concentrations of benthivores. Cessation of salt production in 1993 and subsequent reduction in water depth resulted in a decline of some diving duck populations that used the salt ponds.

  13. The Salt-Gradient Solar Pond.

    Science.gov (United States)

    1983-02-01

    X rGP)**2H1*(DEFH+X1 UP)(i... X CP( *(E-’PfH+XTGP]/lo) 10851) y 1000)i(IC tZE*X~GT*0.) 109001 11110 D( I )= (,,+* IELT *PtH1 ( 2) 2/ .o+4LX ) ( I.’(Q...2.*LLX**2)( I.-(0*DRbT)/(DELX 12100 _. D *42)) +PhI()+((* iELT )/(2.*(.ELA*42) ))PHI(T-1)+(EELT/2.. -1 2 3 0 9 ... . . .... ---(1 I

  14. Use of clays as liners in solar ponds

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Gerardo [Facultad de Ingenieria, Universidad Anahuac Mexico Norte, Huixquilucan, Edo. de Mexico 52786 (Mexico); Almanza, Rafael [Instituto de Ingenieria, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, Mexico D.F. 04510 (Mexico)

    2009-06-15

    An alternative to synthetic materials for use in solar pond liners is to select clayey soils as hydraulic barriers. This option reduces the cost of construction and the risk of contamination of subsoil and groundwater by hot brines. This paper deals with the physical, chemical and hydraulic properties of different soils tested mainly as compacted clay liners. The underdeveloped nations have the option to use this type of liner, but before doing so several tests are recommended, including those for soil and water composition, permeability, plasticity and X-ray diffraction analysis. In this investigation the following samples are analyzed: native clayey soils with illite, montmorillonite and halloysite, treated and non-treated bentonites in powder and granulated form, a mixture of zeolite and sodium bentonite, and industrial minerals composed largely of halloysite, kaolinite and attapulgite selected clays. Neutral salt aqueous solutions (NaCl and KCl) at different concentrations and under temperature gradients were used for compatibility testing conducted on these specimens. Experiment setup and particular testing procedures are also discussed. (author)

  15. Quality monitoring of salt produced in Indonesia through seawater evaporation on HDPE geomembrane lined ponds

    Science.gov (United States)

    Jumaeri; Sulistyaningsih, T.; Alighiri, D.

    2018-03-01

    Salt is one of the primary ingredients that humans always need for various purposes, both for consumption and industry. The need for high-quality salt continues to increase, as long as industry growth. It must improve product quality through the development of salt production process technology. In this research, the quality monitoring of salt produced in Indonesia by evaporation of seawater on ponds lined using high-density polyethylene (HDPE) geomembrane has been studied. The manufacturing of salt carried out through the gradual precipitation principle on prepared ponds. HDPE geomembrane is used to coat evaporation ponds with viscosity 12-22°Be and crystallization ponds with a viscosity of 23°Be. The monitoring of the product is carried out in the particular periods during the salt production period. The result of control shows that the quality of salt produced in HDPE geomembrane coated salt ponds has an average NaCl content of 95.75%, so it has fulfilled with Indonesia National Standard (SNI), that is NaCl> 94.70%. The production of salt with HDPE geomembrane can improve the quality of salt product from NaCl 85.4% (conventional system) to 95.75%.

  16. Site-Specific Research Conducted in Support of the Salton Sea Solar Pond Project - FY 1982 Report

    Science.gov (United States)

    French, R. L.; Marsh, H. E.; Roschke, E. J.; Wu, Y. C.

    1984-01-01

    The design and operation of a salt-gradient solar pond power plant at the Salton Sea presents problems not encountered at small research ponds that were built in the United States. The specific characteristics of the Salton Sea site and the desire to construct the pond using the local clay as a sealant represent major deviations from previous solar pond experience. The site-specific research in support of the plant design is described. The research activity included validation of the spectrophotometric light transmission measurement technique, a search for options for clarifying the turbid and colored water of the Salton Sea, development of water clarification specifications in terms common to industry practice, quantification of gas production from microbiological reactions in the ground, a determination of the combined effects of temperature and salinity on the permeation of the local clays, and a preliminary evaluation of material corrosion.

  17. Greenhouse heating with a fresh water floating collector solar pond

    International Nuclear Information System (INIS)

    Arbel, A.; Sokolov, M.

    1991-01-01

    The fresh water floating collector solar pond was investigated both experimentally and theoretically in a previous work, and it is now matched, by simulation, with the heat load requirements of a greenhouse. Results of the simulation indicate that such a pond is a potential energy source for greenhouse heating. This is especially true when the material properties are such that solar absorption and storage are enhanced. This paper reports that to demonstrate this point, three sets of collectors constructed with materials of different physical (radiation) properties were tested. One set is constructed of common materials which are readily available and are normally used as covers for greenhouses. The second set made of improved materials which are also available but have a smaller long-wave transmittance. The last set made of ideal material which additionally possesses selective radiation absorption properties. Collectors made of ideal materials make a superior solar pond; thus, manufacturing films with improved properties should become a worthwhile challenge for the agricultural polyethylene-films industry. Preliminary economic studies indicate that even with the low oil (<$20/Bbl) prices which exist between 1986-1989, the fresh water floating collectors solar pond provides an economically attractive alternative to the conventional oil-burning heating system. This is especially true in mild climate areas and when the large initial investment is justified by long-term greenhouse utilization planning

  18. Natural heat storage in a brine-filled solar pond in the Tully Valley of central New York

    Science.gov (United States)

    Hayhurst, Brett; Kappel, William M.

    2014-01-01

    The Tully Valley, located in southern Onondaga County, New York, has a long history of unusual natural hydrogeologic phenomena including mudboils (Kappel, 2009), landslides (Tamulonis and others, 2009; Pair and others, 2000), landsurface subsidence (Hackett and others, 2009; Kappel, 2009), and a brine-filled sinkhole or “Solar pond” (fig. 1), which is documented in this report. A solar pond is a pool of salty water (brine) which stores the sun’s energy in the form of heat. The saltwater naturally forms distinct layers with increasing density between transitional zones (haloclines) of rapidly changing specific conductance with depth. In a typical solar pond, the top layer has a low salt content and is often times referred to as the upper convective zone (Lu and others, 2002). The bottom layer is a concentrated brine that is either convective or temperature stratified dependent on the surrounding environment. Solar insolation is absorbed and stored in the lower, denser brine while the overlying halocline acts as an insulating layer and prevents heat from moving upwards from the lower zone (Lu and others, 2002). In the case of the Tully Valley solar pond, water within the pond can be over 90 degrees Fahrenheit (°F) in late summer and early fall. The purpose of this report is to summarize observations at the Tully Valley brine-filled sinkhole and provide supplemental climate data which might affect the pond salinity gradients insolation (solar energy).

  19. Avian response to early tidal salt marsh restoration at former commercial salt evaporation ponds in San Francisco Bay, California, USA

    Science.gov (United States)

    Athearn, Nicole D.; Takekawa, John Y.; Shinn, Joel

    2009-01-01

    Restoration of former commercial salt evaporation ponds in the San Francisco Bay estuary is intended to reverse a severe decline (>79%) in tidal salt marshes. San Francisco Bay is a critical migratory stopover site and wintering area for shorebirds and waterfowl, and salt ponds are important high tide roosting and foraging areas. Conservation of past bird abundance is a stated goal of area restoration projects, and early adaptive management will be critical for achieving this objective. However, initial avian response at sites restored to tidal flow may not be indicative of long-term results. For example, winter shorebirds at a 529 ha pond breached in 2002 showed a marked increase in shorebird abundance following breaching. Shorebirds comprised 1% of area totals during 1999-2002 and increased to 46% during 2003-2008. These changes accompanied increased tidal range and sedimentation, but minimal vegetation establishment. Conversely, a fully vegetated, restored 216 ha pond in the same system consistently supported less than 2% of all waterbirds in the region. Early restoration may temporarily increase habitat, but managed ponds will be needed for long-term waterbird abundance within a restored pond-marsh system.

  20. On the addition of heat to solar pond from external sources

    NARCIS (Netherlands)

    Ganguly, S.; Jain, Ravi; Date, Abhijit; Akbarzadeh, Aliakbar

    2017-01-01

    This brief note addresses the method of adding heat to a solar pond from an external source which is used to enhance the performance of a solar pond. Heat energy collected by Evacuated Tube Solar Collectors (ETSC) is transferred by circulating fluid from the Lower Convective Zone (LCZ) of a solar

  1. The effect of sunny area ratios on the thermal performance of solar ponds

    International Nuclear Information System (INIS)

    Bozkurt, Ismail; Karakilcik, Mehmet

    2015-01-01

    Highlights: • The effect of sunny area ratio on model solar ponds in different geometries. • The sunny area ratio was calculated for 8 different cases. • The efficiency of the model solar pond was determined for 8 different cases. • The energy efficiencies of the solar pond are affected by the sizes of the solar pond, strongly. • The results help to select the sizes of the solar pond before construction. - Abstract: In this study, we investigated the effect of the sunny area ratios on thermal efficiency of model solar pond for different cases in Adiyaman, Turkey. For this purpose, we modeled the solar ponds to compute theoretical sunny area ratios of the zones and temperature distributions in order to find the performance of the model solar ponds. Incorporating the finite difference approach, one and two dimensional heat balances were written for inner zones and insulation side walls. Through, careful determination of the dimensions, insulation parameter and incoming solar radiation reaching the storage zone increased the efficiency of the solar pond. The efficiencies of the model solar pond were determined for case1a–2a–3a–4a to be maximum 14.93%, 20.42%, 23.51% and 27.84%, and for case1b–2b–3b–4b to be maximum 12.65%, 16.76%, 21.37% and 23.30% in August, respectively. With the increase of the sunny area ratio, the performance of the solar pond significantly increased. However, with the increasing rate of the surface area, performance increase rate decreased gradually. The results provide a strong perspective to determine the dimensions of the solar pond before starting the project of a solar pond

  2. Solar Pond devices: free energy or bioreactors for Artemia biomass production?

    Science.gov (United States)

    Gouveia, Luisa; Sousa, João; Marques, Ana; Tavares, Célia; Giestas, Margarida

    2009-08-01

    The recent exponential growth in industrial aquaculture has led to a huge increase in Artemia biomass production in order to meet increased fish production needs. The present study explores the potential use of salt gradient solar ponds (SGSPs) for production of Artemia nauplii. An SGSP is a basin of water where solar energy is trapped and collected via an artificially imposed gradient. Three zones can be identified in an SGSP: upper and lower zones, which are both convective, and a middle zone, which is intended to be non-convective. The latter acts as a transparent insulation layer and allows for storage of solar energy at the bottom, where it is available for use. The combination of salt, temperature and high transparency could make SGSPs promising bioreactors for the production of Artemia nauplii. Using particle image velocymetry (PIV) and Shadowgraph visualisation techniques, the behaviour of Artemia nauplii under critical cultivation parameters (namely, salinity, temperature and light) was monitored to determine movement velocity, and how movement of Artemia affects the salt gradient. It was observed that Artemia nauplii constantly follow light, irrespective of adverse salinity and/or temperature conditions. However, despite the substantial displacement of Artemia following the light source, the salt gradient is not disrupted. The suitability of SGSPs as bioreactors for Artemia biomass production was then tested. The results were disappointing, probably due to the lack of sufficient O(2) for Artemia survival and growth. Follow-up trials were conducted aimed at using the SGSP as a green and economically attractive energy source to induce faster hatching of cysts and improved Artemia nauplii growth. The results of these trials, and a case study of Artemia nauplii production using an SGSP, are presented. The authors constructed a Solar Pond device, which they suggest as a novel way of supplying thermal energy for Artemia biomass production in an aquaculture

  3. A mathematical procedure to estimate solar absorptance of shallow water ponds

    International Nuclear Information System (INIS)

    Wu Hongbo; Tang Runsheng; Li Zhimin; Zhong Hao

    2009-01-01

    In this article, a mathematical procedure is developed for estimating solar absorption of shallow water ponds with different pond floor based on the fact that the solar radiation trapped inside the water layer undergoes multiplicative reflection and absorption and on that the solar absorption of water is selective. Theoretical model indicates that the solar absorption of a water pond is related to the reflectivity of the pond floor, the solar spectrum and the water depth. To validate the mathematical model, a concrete water pond measuring 3 x 3 x 0.24 m was constructed. Experimental results indicate that solar reflectivity calculated based on the mathematical model proposed in this work were in good agreement with those measured. For water ponds with a water-permeable floor, such as concrete floor, theoretical calculations of the solar absorptance of a water pond should be done based on the reflectivity of full wet floor, whereas for water ponds with a non-water-permeable floor, theoretical calculations should be done based on the fact that solar reflection on the floor is neither perfect specular reflection nor prefect isotropic diffuse reflection. Results of numerical calculation show that theoretical calculations of solar absorption of a water pond by dividing solar spectrum into six bands were pretty agreement with those by dividing solar spectrum into 20 bands.

  4. Using nanofluids in enhancing the performance of a novel two-layer solar pond

    International Nuclear Information System (INIS)

    Al-Nimr, Moh'd A.; Al-Dafaie, Ameer Mohammed Abbas

    2014-01-01

    A novel two-layer nanofluid solar pond is introduced. A mathematical model that describes the thermal performance of the pond has been developed and solved. The upper layer of the pond is made of mineral oil and the lower layer is made of nanofluid. Nanofluid is known to be an excellent solar radiation absorber, and this has been tested and verified using the mathematical model. Using nanofluid will increase the extinction coefficient of the lower layer and consequently will improve the thermal efficiency and the storage capacity of the pond. The effects of other parameters have been also investigated. - Highlights: • A novel two-layer solar pond is discussed. • Nanofluid as thermal energy storage is used in this pond. • A mathematical model is developed to predict the performance of the pond. • The mathematical model is solved using Green's function. • The pond is simulated for different values of governing parameter

  5. Remote sensing of the biological dynamics of large-scale salt evaporation ponds

    Science.gov (United States)

    Richardson, Laurie L.; Bachoon, Dave; Ingram-Willey, Vebbra; Chow, Colin C.; Weinstock, Kenneth

    1992-01-01

    Optical properties of salt evaporation ponds associated with Exportadora de Sal, a salt production company in Baja California Sur, Mexico, were analyzed using a combination of spectroradiometer and extracted pigment data, and Landsat-5 Thematic Mapper imagery. The optical characteristics of each pond are determined by the biota, which consists of dense populations of algae and photosynthetic bacteria containing a wide variety of photosynthetic and photoprotective pigments. Analysis has shown that spectral and image data can differentiate between taxonomic groups of the microbiota, detect changes in population distributions, and reveal large-scale seasonal dynamics.

  6. Habitat selection by Forster's Terns (Sterna forsteri) at multiple spatial scales in an urbanized estuary: The importance of salt ponds

    Science.gov (United States)

    Bluso-Demers, Jill; Ackerman, Joshua T.; Takekawa, John Y.; Peterson, Sarah

    2016-01-01

    The highly urbanized San Francisco Bay Estuary, California, USA, is currently undergoing large-scale habitat restoration, and several thousand hectares of former salt evaporation ponds are being converted to tidal marsh. To identify potential effects of this habitat restoration on breeding waterbirds, habitat selection of radiotagged Forster's Terns (Sterna forsteri) was examined at multiple spatial scales during the pre-breeding and breeding seasons of 2005 and 2006. At each spatial scale, habitat selection ratios were calculated by season, year, and sex. Forster's Terns selected salt pond habitats at most spatial scales and demonstrated the importance of salt ponds for foraging and roosting. Salinity influenced the types of salt pond habitats that were selected. Specifically, Forster's Terns strongly selected lower salinity salt ponds (0.5–30 g/L) and generally avoided higher salinity salt ponds (≥31 g/L). Forster's Terns typically used tidal marsh and managed marsh habitats in proportion to their availability, avoided upland and tidal flat habitats, and strongly avoided open bay habitats. Salt ponds provide important habitat for breeding waterbirds, and restoration efforts to convert former salt ponds to tidal marsh may reduce the availability of preferred breeding and foraging areas.

  7. Trends and habitat associations of waterbirds using the South Bay Salt Pond Restoration Project, San Francisco Bay, California

    Science.gov (United States)

    De La Cruz, Susan E. W.; Smith, Lacy M.; Moskal, Stacy M.; Strong, Cheryl; Krause, John; Wang, Yiwei; Takekawa, John Y.

    2018-04-02

    Executive SummaryThe aim of the South Bay Salt Pond Restoration Project (hereinafter “Project”) is to restore 50–90 percent of former salt evaporation ponds to tidal marsh in San Francisco Bay (SFB). However, hundreds of thousands of waterbirds use these ponds over winter and during fall and spring migration. To ensure that existing waterbird populations are supported while tidal marsh is restored in the Project area, managers plan to enhance the habitat suitability of ponds by adding islands and berms to change pond topography, manipulating water salinity and depth, and selecting appropriate ponds to maintain for birds. To help inform these actions, we used 13 years of monthly (October–April) bird abundance data from Project ponds to (1) assess trends in waterbird abundance since the inception of the Project, and (2) evaluate which pond habitat characteristics were associated with highest abundances of different avian guilds and species. For comparison, we also evaluated waterbird abundance trends in active salt production ponds using 10 years of monthly survey data.We assessed bird guild and species abundance trends through time, and created separate trend curves for Project and salt production ponds using data from every pond that was counted in a year. We divided abundance data into three seasons—fall (October–November), winter (December–February), and spring (March–April). We used the resulting curves to assess which periods had the highest bird abundance and to identify increasing or decreasing trends for each guild and species.

  8. Unintended consequences of management actions in salt pond restoration: cascading effects in trophic interactions.

    Directory of Open Access Journals (Sweden)

    John Y Takekawa

    Full Text Available Salt evaporation ponds have played an important role as habitat for migratory waterbirds across the world, however, efforts to restore and manage these habitats to maximize their conservation value has proven to be challenging. For example, salinity reduction has been a goal for restoring and managing former salt evaporation ponds to support waterbirds in the South Bay Salt Pond Restoration Project in San Francisco Bay, California, USA. Here, we describe a case study of unexpected consequences of a low-dissolved oxygen (DO event on trophic interactions in a salt pond system following management actions to reduce salinity concentrations. We document the ramifications of an anoxic event in water quality including salinity, DO, and temperature, and in the response of the biota including prey fish biomass, numerical response by California Gulls (Larus californicus, and chick survival of Forster's Tern (Sterna forsteri. Management actions intended to protect receiving waters resulted in decreased DO concentrations that collapsed to zero for ≥ 4 consecutive days, resulting in an extensive fish kill. DO depletion likely resulted from an algal bloom that arose following transition of the pond system from high to low salinity as respiration and decomposition outpaced photosynthetic production. We measured a ≥ 6-fold increase in biomass of fish dropped on the levee by foraging avian predators compared with weeks prior to and following the low-DO event. California Gulls rapidly responded to the availability of aerobically-stressed and vulnerable fish and increased in abundance by two orders of magnitude. Mark-recapture analysis of 254 Forster's Tern chicks indicated that their survival declined substantially following the increase in gull abundance. Thus, management actions to reduce salinity concentrations resulted in cascading effects in trophic interactions that serves as a cautionary tale illustrating the importance of understanding the interaction

  9. Unintended consequences of management actions in salt pond restoration: cascading effects in trophic interactions

    Science.gov (United States)

    Takekawa, John Y.; Ackerman, Joshua T.; Brand, Arriana; Graham, Tanya R.; Eagles-Smith, Collin A.; Herzog, Mark; Topping, Brent R.; Shellenbarger, Gregory; Kuwabara, James S.; Mruz, Eric; Piotter, Sara L.; Athearn, Nicole D.

    2015-01-01

    Salt evaporation ponds have played an important role as habitat for migratory waterbirds across the world, however, efforts to restore and manage these habitats to maximize their conservation value has proven to be challenging. For example, salinity reduction has been a goal for restoring and managing former salt evaporation ponds to support waterbirds in the South Bay Salt Pond Restoration Project in San Francisco Bay, California, USA. Here, we describe a case study of unexpected consequences of a low-dissolved oxygen (DO) event on trophic interactions in a salt pond system following management actions to reduce salinity concentrations. We document the ramifications of an anoxic event in water quality including salinity, DO, and temperature, and in the response of the biota including prey fish biomass, numerical response by California Gulls (Larus californicus), and chick survival of Forster's Tern (Sterna forsteri). Management actions intended to protect receiving waters resulted in decreased DO concentrations that collapsed to zero for ≥ 4 consecutive days, resulting in an extensive fish kill. DO depletion likely resulted from an algal bloom that arose following transition of the pond system from high to low salinity as respiration and decomposition outpaced photosynthetic production. We measured a ≥ 6-fold increase in biomass of fish dropped on the levee by foraging avian predators compared with weeks prior to and following the low-DO event. California Gulls rapidly responded to the availability of aerobically-stressed and vulnerable fish and increased in abundance by two orders of magnitude. Mark-recapture analysis of 254 Forster's Tern chicks indicated that their survival declined substantially following the increase in gull abundance. Thus, management actions to reduce salinity concentrations resulted in cascading effects in trophic interactions that serves as a cautionary tale illustrating the importance of understanding the interaction of water quality

  10. Unintended consequences of management actions in salt pond restoration: cascading effects in trophic interactions.

    Science.gov (United States)

    Takekawa, John Y; Ackerman, Joshua T; Brand, L Arriana; Graham, Tanya R; Eagles-Smith, Collin A; Herzog, Mark P; Topping, Brent R; Shellenbarger, Gregory G; Kuwabara, James S; Mruz, Eric; Piotter, Sara L; Athearn, Nicole D

    2015-01-01

    Salt evaporation ponds have played an important role as habitat for migratory waterbirds across the world, however, efforts to restore and manage these habitats to maximize their conservation value has proven to be challenging. For example, salinity reduction has been a goal for restoring and managing former salt evaporation ponds to support waterbirds in the South Bay Salt Pond Restoration Project in San Francisco Bay, California, USA. Here, we describe a case study of unexpected consequences of a low-dissolved oxygen (DO) event on trophic interactions in a salt pond system following management actions to reduce salinity concentrations. We document the ramifications of an anoxic event in water quality including salinity, DO, and temperature, and in the response of the biota including prey fish biomass, numerical response by California Gulls (Larus californicus), and chick survival of Forster's Tern (Sterna forsteri). Management actions intended to protect receiving waters resulted in decreased DO concentrations that collapsed to zero for ≥ 4 consecutive days, resulting in an extensive fish kill. DO depletion likely resulted from an algal bloom that arose following transition of the pond system from high to low salinity as respiration and decomposition outpaced photosynthetic production. We measured a ≥ 6-fold increase in biomass of fish dropped on the levee by foraging avian predators compared with weeks prior to and following the low-DO event. California Gulls rapidly responded to the availability of aerobically-stressed and vulnerable fish and increased in abundance by two orders of magnitude. Mark-recapture analysis of 254 Forster's Tern chicks indicated that their survival declined substantially following the increase in gull abundance. Thus, management actions to reduce salinity concentrations resulted in cascading effects in trophic interactions that serves as a cautionary tale illustrating the importance of understanding the interaction of water quality

  11. Geochemistry and toxicity of sediment porewater in a salt-impacted urban stormwater detention pond

    International Nuclear Information System (INIS)

    Mayer, T.; Rochfort, Q.; Borgmann, U.; Snodgrass, W.

    2008-01-01

    A comprehensive study was carried out to investigate the impacts of road salts on the benthic compartment of a small urban detention facility, Rouge River Pond. Although the pond is an engineered water body, it is representative of many small urban lakes, ponds and wetlands, which receive road runoff and are probable high impact areas. Specific objectives of the study were to document the porewater chemistry of an aquatic system affected by elevated salt concentrations and to carry out a toxicological assessment of sediment porewater to determine what factors may cause porewater toxicity. The results indicate that the sediment porewater may itself attain high salt concentrations. The computations show that increased chloride levels have important implications on the Cd complexation, augmenting its concentration in porewater. The toxicity tests suggest that the toxicity in porewater is caused by metals or other toxic chemicals, rather than high levels of chloride. - Effects of chlorides on metal chemistry and toxicity of sediment porewater in a stormwater detention pond impacted by road salts

  12. Tolerance to road salt deicers in chronically exposed urban pond communities

    Science.gov (United States)

    Freshwater salinization is a concern in urban aquatic ecosystems that receive road salt runoff from vast expanses of impervious surface cover. Our study was designed to evaluate the effects of chloride contamination on urban stormwater pond food webs and to assess the tolerance o...

  13. Isolation and characterization of halophilic bacteria and archaea from salt ponds in Hangu Saltworks, Tianjin, China

    Science.gov (United States)

    Deng, Yuangao; Xu, Gaochao; Sui, Liying

    2015-07-01

    A total of 26 isolates were obtained from solar salt ponds of different salinities (100, 150, 200, and 250) in Hangu Saltworks Co. Ltd., Tianjin, China. Phylogenetic analysis of 16S rRNA gene sequences indicated that five bacteria genera Halomonas, Salinicoccus, Oceanobacillus, Gracibacillus, and Salimicrobium and one archaea genera Halorubrum were present. The genus Halomonas was predominant with eight strains distributed in a salinity range of 100-200, followed by Halorubrum with six strains in salinity 250. Based on the genus and original sampling salinity, eight bacterial and two archaeal isolates were selected for further morphological, physiological, and biochemical characterization. All of the bacterial strains were moderately halophilic with the optimal salinity for growth being either 50 or 100, while two archaeal strains were extremely halophilic with an optimal growth salinity of 200. Additionally, we put forth strain SM.200-5 as a new candidate Salimicrobium species based on the phylogenic analysis of the 16S rRNA gene sequence and its biochemical characteristics when compared with known related species.

  14. Predicting salt advection in groundwater from saline aquaculture ponds

    Science.gov (United States)

    Verrall, D. P.; Read, W. W.; Narayan, K. A.

    2009-01-01

    SummaryThis paper predicts saltwater advection in groundwater from leaky aquaculture ponds. A closed form solution for the potential function, stream function and velocity field is derived via the series solutions method. Numerically integrating along different streamlines gives the location (or advection front) of saltwater throughout the domain for any predefined upper time limit. Extending this process produces a function which predicts advection front location against time. The models considered in this paper are easily modified given knowledge of the required physical parameters.

  15. An experimental and theoretical investigation of novel configurations of solar ponds for use in Iraq.

    OpenAIRE

    Sayer, Asaad Hameed

    2017-01-01

    Solar energy is likely to be the energy of the future; solar ponds, especially salinity gradient solar ponds (SGSPs), facilitate simple and cost-effective thermal energy storage. Research on maximising their potential is of particular relevance to developing countries, which often have an abundance of solar energy and a critical need for increased power supplies. For this research, a theoretical model for heat transfer in a SGSP was developed to study the energy balance in the three separate ...

  16. Design and Application of a Solar Mobile Pond Aquaculture Water Quality-Regulation Machine Based in Bream Pond Aquaculture.

    Science.gov (United States)

    Liu, Xingguo; Xu, Hao; Ma, Zhuojun; Zhang, Yongjun; Tian, Changfeng; Cheng, Guofeng; Zou, Haisheng; Lu, Shimin; Liu, Shijing; Tang, Rong

    2016-01-01

    Bream pond aquaculture plays a very important role in China's aquaculture industry and is the main source of aquatic products. To regulate and control pond water quality and sediment, a movable solar pond aquaculture water quality regulation machine (SMWM) was designed and used. This machine is solar-powered and moves on water, and its primary components are a solar power supply device, a sediment lifting device, a mechanism for walking on the water's surface and a control system. The solar power supply device provides power for the machine, and the water walking mechanism drives the machine's motion on the water. The sediment lifting device orbits the main section of the machine and affects a large area of the pond. Tests of the machine's mechanical properties revealed that the minimum illumination necessary for the SMWM to function is 13,000 Lx and that its stable speed on the water is 0.02-0.03 m/s. For an illumination of 13,000-52,500 Lx, the sediment lifting device runs at 0.13-0.35 m/s, and its water delivery capacity is 110-208 m(3)/h. The sediment lifting device is able to fold away, and the angle of the suction chamber can be adjusted, making the machine work well in ponds at different water depths from 0.5 m to 2 m. The optimal distance from the sediment lifting device to the bottom of the pond is 10-15 cm. In addition, adjusting the length of the connecting rod and the direction of the traction rope allows the SMWM to work in a pond water area greater than 80%. The analysis of water quality in Wuchang bream (Parabramis pekinensis) and silver carp (Hypophthalmichthys molitrix) culture ponds using the SMWM resulted in decreased NH3(+)-N and available phosphorus concentrations and increased TP concentrations. The TN content and the amount of available phosphorus in the sediment were reduced. In addition, the fish production showed that the SMWM enhanced the yields of Wuchang bream and silver carp by more than 30% and 24%, respectively. These results

  17. Passive flow heat exchanger simulation for power generation from solar pond using thermoelectric generators

    Science.gov (United States)

    Baharin, Nuraida'Aadilia; Arzami, Amir Afiq; Singh, Baljit; Remeli, Muhammad Fairuz; Tan, Lippong; Oberoi, Amandeep

    2017-04-01

    In this study, a thermoelectric generator heat exchanger system was designed and simulated for electricity generation from solar pond. A thermoelectric generator heat exchanger was studied by using Computational Fluid Dynamics to simulate flow and heat transfer. A thermoelectric generator heat exchanger designed for passive in-pond flow used in solar pond for electrical power generation. A simple analysis simulation was developed to obtain the amount of electricity generated at different conditions for hot temperatures of a solar pond at different flow rates. Results indicated that the system is capable of producing electricity. This study and design provides an alternative way to generate electricity from solar pond in tropical countries like Malaysia for possible renewable energy applications.

  18. Dewatering and RCRA partial closure action on solar evaporation ponds, Rocky Flats Plant, Golden, Colorado

    International Nuclear Information System (INIS)

    1991-06-01

    The Department of Energy (DOE) has prepared an Environmental Assessment (DOE/EA-0487) on its proposal to partially close five solar evaporation ponds at the Rocky Flats Plant (RFP) pursuant to the requirements of the Resource Conservation and Recovery Act (RCRA). This proposal would be known as a RCRA partial closure and would be accomplished by dewatering the ponds, where necessary, and converting any remaining sludge or evaporator concentrate to a solid wasteform (pondcrete and saltcrete). The pond sites would be stabilized to prevent erosion or other disturbance to the soil and to prevent infiltration of rain or snowmelt. The solid wasteform would be transported offsite for disposal. The five solar ponds (designated 207-A, 207-B (north, center, and south), and 207-C), are the only solar evaporation ponds that exist at the RFP. A finding of no significant impact is included

  19. Solar-thermal-energy collection/storage-pond system

    Science.gov (United States)

    Blahnik, D.E.

    1982-03-25

    A solar thermal energy collection and storage system is disclosed. Water is contained, and the water surface is exposed directly to the sun. The central part of an impermeable membrane is positioned below the water's surface and above its bottom with a first side of the membrane pointing generally upward in its central portion. The perimeter part of the membrane is placed to create a watertight boundary separating the water into a first volume which is directly exposable to the sun and which touches the membranes first side, and a second volumn which touches the membranes second side. A salt is dissolved in the first water volume.

  20. Hyperspectral Biofilm Classification Analysis for Carrying Capacity of Migratory Birds in the South Bay Salt Ponds

    Science.gov (United States)

    Hsu, Wei-Chen; Kuss, Amber Jean; Ketron, Tyler; Nguyen, Andrew; Remar, Alex Covello; Newcomer, Michelle; Fleming, Erich; Debout, Leslie; Debout, Brad; Detweiler, Angela; hide

    2011-01-01

    Tidal marshes are highly productive ecosystems that support migratory birds as roosting and over-wintering habitats on the Pacific Flyway. Microphytobenthos, or more commonly 'biofilms' contribute significantly to the primary productivity of wetland ecosystems, and provide a substantial food source for macroinvertebrates and avian communities. In this study, biofilms were characterized based on taxonomic classification, density differences, and spectral signatures. These techniques were then applied to remotely sensed images to map biofilm densities and distributions in the South Bay Salt Ponds and predict the carrying capacity of these newly restored ponds for migratory birds. The GER-1500 spectroradiometer was used to obtain in situ spectral signatures for each density-class of biofilm. The spectral variation and taxonomic classification between high, medium, and low density biofilm cover types was mapped using in-situ spectral measurements and classification of EO-1 Hyperion and Landsat TM 5 images. Biofilm samples were also collected in the field to perform laboratory analyses including chlorophyll-a, taxonomic classification, and energy content. Comparison of the spectral signatures between the three density groups shows distinct variations useful for classification. Also, analysis of chlorophyll-a concentrations show statistically significant differences between each density group, using the Tukey-Kramer test at an alpha level of 0.05. The potential carrying capacity in South Bay Salt Ponds is estimated to be 250,000 birds.

  1. Environmental sampling program for a solar evaporation pond for liquid radioactive wastes

    International Nuclear Information System (INIS)

    Romero, R.; Gunderson, T.C.; Talley, A.D.

    1980-04-01

    Los Alamos Scientific Laboratory (LASL) is evaluating solar evaporation as a method for disposal of liquid radioactive wastes. This report describes a sampling program designed to monitor possible escape of radioactivity to the environment from a solar evaporation pond prototype constructed at LASL. Background radioactivity levels at the pond site were determined from soil and vegetation analyses before construction. When the pond is operative, the sampling program will qualitatively and quantitatively detect the transport of radioactivity to the soil, air, and vegetation in the vicinity. Possible correlation of meteorological data with sampling results is being investigated and measures to control export of radioactivity by biological vectors are being assessed

  2. Stabilization of mixed waste - Rocky Flats solar ponds

    International Nuclear Information System (INIS)

    Bittner, T.A.; Mathew, S.A.; Henderson, W.C.

    1993-01-01

    Among the wastes that require disposal as part of the Department of Energy's (DOE's) Environmental Restoration Program are large amounts of contaminated sludge and inorganic wastes. Halliburton NUS Corporation was awarded a contract by EG ampersand G Rocky Flats in March 1991 to stabilize mixed waste sludge contained in five solar evaporator ponds and to reprocess billets of solidified waste called Pondcrete and Saltcrete at DOE's Rocky Flats Plant. The scope of the project consists of waste characterization and treatability studies for process development, followed by design, construction and operation of various process trains to remediate different waste forms ranging from solid Pondcrete/Saltcrete blocks to aqueous brine solutions. One of the significant advances made was the development of a durable and certifiable stabilization formulation capable of treating concentrated nitrate solution wastes. The project uses high-volume grout mixing and pumping technologies with process control techniques that accommodate the heterogeneity of the wastes. To comply with all relevant environmental regulations and to provide a safe working atmosphere for plant personnel, Halliburton NUS designed process trains such that all emissions were eliminated during the remediation process. Personnel protection equipment requirements have been downgraded due to safeguards incorporated in the design. The technical and regulatory issues that were encountered would be typical of stabilization efforts underway at other DOE sites. Thus the lessons learned and concepts developed can be expected to have widespread application

  3. Dietary flexibility in three representative waterbirds across salinity and depth gradients in salt ponds of San Francisco Bay

    Science.gov (United States)

    Takekawa, John Y.; Miles, A.K.; Tsao-Melcer, D. C.; Schoellhamer, D.H.; Fregien, S.; Athearn, N.D.

    2009-01-01

    Salt evaporation ponds have existed in San Francisco Bay, California, for more than a century. In the past decade, most of the salt ponds have been retired from production and purchased for resource conservation with a focus on tidal marsh restoration. However, large numbers of waterbirds are found in salt ponds, especially during migration and wintering periods. The value of these hypersaline wetlands for waterbirds is not well understood, including how different avian foraging guilds use invertebrate prey resources at different salinities and depths. The aim of this study was to investigate the dietary flexibility of waterbirds by examining the population number and diet of three feeding guilds across a salinity and depth gradient in former salt ponds of the Napa-Sonoma Marshes. Although total invertebrate biomass and species richness were greater in low than high salinity salt ponds, waterbirds fed in ponds that ranged from low (20 g l-1) to very high salinities (250 g l -1). American avocets (surface sweeper) foraged in shallow areas at pond edges and consumed a wide range of prey types (8) including seeds at low salinity, but preferred brine flies at mid salinity (40-80 g l-1). Western sandpipers (prober) focused on exposed edges and shoal habitats and consumed only a few prey types (2-4) at both low and mid salinities. Suitable depths for foraging were greatest for ruddy ducks (diving benthivore) that consumed a wide variety of invertebrate taxa (5) at low salinity, but focused on fewer prey (3) at mid salinity. We found few brine shrimp, common in higher salinity waters, in the digestive tracts of any of these species. Dietary flexibility allows different guilds to use ponds across a range of salinities, but their foraging extent is limited by available water depths. ?? 2009 USGS, US Government.

  4. Stability considerations and a double-diffusive convection model for solar ponds

    Energy Technology Data Exchange (ETDEWEB)

    Lin, E.I.H.; Sha, W.T.; Soo, S.L.

    1979-04-01

    A brief survey is made on the basic principles, current designs and economic advantages of salinity-gradient solar ponds as solar collectors and reservoirs. Solar ponds are well-suited for various AIPH (agricultural and industrial process heat) applications, and as annual storage devices for space heating and cooling. The benefit of an efficient pond is demonstrated via a preliminary economic analysis which suggests the idea of energy farming as a profitable alternative for land usage in the face of rising fuel cost. The economy and reliability of solar-pond operation depend crucially on the stability of the nonconvective gradient zone against disturbances such as generated by a severe weather condition. Attention is focused on the subject of stability, and pertinent existing results are summarized and discussed. Details of the derivation of three-dimensional stability criteria for thermohaline convection with linear gradients are presented. Ten key questions pertaining to stability are posed, whose answers must be sought through extensive analytical and numerical studies. Possible methods of approach toward enhancing solar-pond stability are also discussed. For the numerical studies of pond behavior and stability characteristics, a double-diffusive convection model is proposed. The model can be constructed by extending the three-dimensional thermohydrodynamic computer code COMMIX-SA, following the necessary steps outlined; computational plans are described. Similarities exist between the halothermocline and the thermocline storage systems, and an extended COMMIX-SA will be a valuable tool for the investigation of both.

  5. 78 FR 56921 - South Bay Salt Pond Restoration Project, Phase 2 (Ponds R3, R4, R5, S5, A1, A2W, A8, A8S, A19...

    Science.gov (United States)

    2013-09-16

    ...-F2013227943] South Bay Salt Pond Restoration Project, Phase 2 (Ponds R3, R4, R5, S5, A1, A2W, A8, A8S, A19... South Bay Salt Pond Restoration Project and consists of restoring and enhancing over 2,000 acres of... Pollution Control Plant located at 700 Los Esteros Road, San Jose, California. The details of the public...

  6. Elemental signature of terrigenous sediment runoff as recorded in coastal salt ponds: US Virgin Islands

    International Nuclear Information System (INIS)

    Larson, Rebekka A.; Brooks, Gregg R.; Devine, Barry; Schwing, Patrick T.; Holmes, Charles W.; Jilbert, Tom; Reichart, Gert-Jan

    2015-01-01

    A high-resolution, multi-proxy approach is utilized on mm- to cm-scale laminated coastal salt pond sediments from St. John, U.S. Virgin Islands, to determine: (1) the sedimentological signature of depositional events/processes, (2) link this sedimentological signature with known depositional events/processes in the historical (past ∼100 years) record; and, (3) project back into the recent geologic past (past ∼1400 years) to investigate the natural variability of depositional events/processes. High-resolution, short-lived radioisotope geochronology ("2"1"0Pb, "1"3"7Cs, "7Be) combined with high-resolution elemental scanning techniques (scanning XRF and scanning LA-ICP-MS) allows for the direct comparison of well-preserved salt pond deposits to historical records of depositional events (e.g., runoff/rainfall, tropical cyclones, tsunamis) to identify the sedimentary signature of each type of event. There is a robust sedimentary record of terrigenous sediment runoff linked to the frequency of rainfall events that exceed a threshold of ∼12 mm/day (minimum to mobilize and transport sediment) for study sites. This is manifested in the sedimentary record as increases in terrigenous indicator elements (%Al, %Fe, %Ti, %Si), which agree well with rainfall records over the past ∼50 years. Variability in the sedimentary record over the past ∼100 years reflects decadal-scale fluctuations between periods of increased frequency of rainfall events, and decreased frequency of rainfall events. Dm-scale variability in terrigenous indicator elements over the past ∼1400 years represents the natural system variability on a decadal–centennial scale, and provides a high-resolution, long-term baseline of natural variability of rainfall/runoff events. A period of increased terrigenous sediment delivery during the 1700s and 1800s likely indicates increased erosion in response to anthropogenic activities associated with the island’s plantation era, and perhaps increased

  7. Tsunami Stratigraphy in a Coastal Salt Pond, St. Croix, US Virgin Islands

    Science.gov (United States)

    Russell, P.; Browning, T. N.; Brooks, G.; Larson, R. A.; Cook, A.; Sawyer, D. E.

    2017-12-01

    The Caribbean has significant exposure to tsunamis from multiple sources, such as earthquakes, volcanoes, and landslides. Due to the limited historical record in the region, paleotsunami deposits provide important information about the size, location, and sources of these events. In turn, these data inform the public and policymakers about the tsunamigenic threat to their communities. A key challenge is that tsunami deposits are often poorly preserved. However, a good candidate for high preservation potential are coastal salt ponds commonly found on the perimeter of tropical islands. The US Virgin Islands has both high susceptibility to tsunamis and large, low lying salt ponds. The most prominent historical example of a tsunami in the US Virgin Islands is the 1867 event which caused widespread devastation throughout the region, including Puerto Rico. One of the hardest hit locations was Frederiksted, on the western end of St. Croix, US Virgin Islands with 7m runups that beached the USS Monongahela. Frederiksted is also in close proximity to a large coastal salt pond. We targeted this, and older, events by collecting a series of sediment cores at four sites in the salt pond during a summer 2017 field campaign. At each location we acquired a 3" aluminum core and a 4" acrylic companion core to core refusal, which most often occurred at a impenetrable horizon. Maximum core recovery was .79m and the average was .54m. Each 4" core was extruded in 1cm intervals and used to determine grain size, total carbon content, and age dating via radioisotope dating. The 3" core was scanned in a X-Ray CT Lab, split, described, and samples from key layers were targeted for detailed sedimentological analyses. The defining stratigraphic sequence is fine-grained muds interspersed with coarse-grained units that exhibit a fining-upwards trend and contained a variety of marine debris, which we infer to represent tsunami or tropical storm event deposits. However, each core did not exhibit

  8. Study for reclamation of land occupied by solar evaporation pond at UCIL, Bhopal, India.

    Science.gov (United States)

    George, K V; Patil, M R; Swaminathan, R

    2001-12-01

    Solar Evaporation Ponds (SEP) were used by Union Carbide India Limited (UCIL), Bhopal for storage of wastewater containing high concentrations of inorganic chemicals especially chlorides. Area occupied by the SEPs had to be recovered due to closure of the plant. A prerequisite to the reclamation of the SEP area is a study of adjoining soil and groundwater, which may be contaminated due to possible leakage in the pond. Surface soil, subsurface soil and groundwater samples were collected and analysed. The electrical conductivity method was employed inside the pond to test for leak in the geo-membrane liner. This was further confirmed by physically checking the liners. Based on the wet period, total rainfall and evaporation rate of the region, drying of remaining wastewater by spreading in dry ponds followed by pond dismantling was scheduled.

  9. Ground water input to coastal salt ponds of southern Rhode Island estimated using 226Ra as a tracer.

    Science.gov (United States)

    Scott, M K; Moran, S B

    2001-01-01

    The naturally occurring radionuclide 226Ra (t1/2 = 1600 years) was used as a tracer to determine ground water input to Point Judith, Potter, Green Hill and Ninigret ponds in southern Rhode Island. Measurements of 226Ra activity were made in samples collected from salt ponds, pore waters, sediments, and local ground water wells during June-August, 1997. These results were combined with a simple box model to derive ground water input fluxes of 0.1-0.3 cm3 cm-2 d-1 (2-5 x 10(7) L d-1), which are comparable to previous estimates of ground water input to these ponds.

  10. Thermal Desalination using MEMS and Salinity-Gradient Solar Pond Technology

    Science.gov (United States)

    Lu, H.; Walton, J. C.; Hein, H.

    2002-08-01

    MEMS (multi-effect, multi-stage) flash desalination (distillation) driven by thermal energy derived from a salinity-gradient solar pond is investigated in this study for the purpose of improving the thermodynamic efficiency and economics of this technology. Three major tasks are performed: (1) a MEMS unit is tested under various operating conditions at the El Paso Solar Pond site; (2) the operation and maintenance procedures of the salinity-gradient solar pond coupled with the MEMS operation is studied; and (3) previous test data on a 24-stage, falling-film flash distillation unit (known as the Spinflash) is analyzed and compared with the performance of the MEMS unit. The data and information obtained from this investigation is applicable to a variety of thermal desalination processes using other solar options and/or waste heat.

  11. Solar pond-based rural development programme for selected coastal regions - A concept

    Digital Repository Service at National Institute of Oceanography (India)

    Gopinathan, C.K.

    is expected to aid speedy development of selected coastal areas. The programme involves design and construction of a solar pond in which brine in the lower layer is heated to 85 degrees C by solar radiation and is used as the heat source for a closed cycle...

  12. Thermal performance of a single-basin solar still integrated with a shallow solar pond

    International Nuclear Information System (INIS)

    El-Sebaii, A.A.; Ramadan, M.R.I.; Aboul-Enein, S.; Salem, N.

    2008-01-01

    In an attempt to improve the daily productivity of the single effect solar stills, a single-slope single-basin solar still integrated with a shallow solar pond (SSP) was studied to perform solar distillation at a relatively high temperature. The energy balance equations of various elements of the considered system were formulated and solved analytically. Suitable computer programs were prepared for optimizing and predicting the thermal performance of the considered system. Numerical calculations were carried out on typical summer and winter days in Tanta (latitude 30 deg. 47'N) for different thicknesses and mass flow rates of the flowing water to study the effect of these parameters on the daily productivity and efficiency of the system. To validate the proposed theoretical model, comparisons between calculated and measured results were carried out. Good agreement has been achieved. The year-round performances of the still with and without the SSP were also investigated. The optimum values of the flowing water thickness and the mass flow rate for this typical configuration of the SSP-active solar still were obtained as 0.03 m and 0.0009 kg/s. The annual average values of the daily productivity P-bar d and efficiency η-bar d of the still with the SSP were found to be higher than those obtained without the SSP by 52.36% and 43.80%, respectively

  13. Thermal performance of a single-basin solar still integrated with a shallow solar pond

    Energy Technology Data Exchange (ETDEWEB)

    El-Sebaii, A.A.; Ramadan, M.R.I.; Aboul-Enein, S.; Salem, N. [Department of Physics, Faculty of Science, Tanta University, Tanta (Egypt)

    2008-10-15

    In an attempt to improve the daily productivity of the single effect solar stills, a single-slope single-basin solar still integrated with a shallow solar pond (SSP) was studied to perform solar distillation at a relatively high temperature. The energy balance equations of various elements of the considered system were formulated and solved analytically. Suitable computer programs were prepared for optimizing and predicting the thermal performance of the considered system. Numerical calculations were carried out on typical summer and winter days in Tanta (latitude 30 47'N) for different thicknesses and mass flow rates of the flowing water to study the effect of these parameters on the daily productivity and efficiency of the system. To validate the proposed theoretical model, comparisons between calculated and measured results were carried out. Good agreement has been achieved. The year-round performances of the still with and without the SSP were also investigated. The optimum values of the flowing water thickness and the mass flow rate for this typical configuration of the SSP-active solar still were obtained as 0.03 m and 0.0009 kg/s. The annual average values of the daily productivity anti P{sub d} and efficiency anti {eta}{sub d} of the still with the SSP were found to be higher than those obtained without the SSP by 52.36% and 43.80%, respectively. (author)

  14. A First Approach to Natural Thermoventilation of Residential Buildings through Ventilation Chimneys Supplied by Solar Ponds

    Directory of Open Access Journals (Sweden)

    Ferdinando Salata

    2015-07-01

    Full Text Available The exploitation of natural ventilation is a good solution to improve buildings from an energetic point of view and to fulfill the requirements demanded by the thermohygrometric comfort and the air quality in enclosed spaces. Some past researches demonstrated how some devices, useful to this purpose, follow the principles of solar chimneys and are able to move air masses while exploiting the Archimedes thrust. The natural ventilation must be supplied by a flow moving upward, generated by a heat source performing at temperatures slightly higher than the one present in the environment. To have a minimum energetic effect, the heat can be extracted from solar ponds; solar ponds are able to collect and store solar energy in the geographical regions characterized by sufficient values of solar radiation. Thus it is possible, in summer, to provoke a nocturnal natural ventilation useful for the air change in indoor spaces (in those climatic areas where, during the night, there is a temperature gradient.

  15. Experimental and comparative study of the effect of paraffin oil and covering for solar ponds without saline water

    Energy Technology Data Exchange (ETDEWEB)

    Spyridonos, A V; Anagnostatos, G S; Novakovic, M M

    1989-01-01

    The effect of a superficial layer of paraffin or a plastic covering on the thermal storage efficiency of three kinds of non-saline solar pond has been investigated. Four small scale ponds were used for experimental measurements. These were: (1) a reference pond; (2) a pond divided horizontally into compartments separated by plastic sheets; (3) a pond with a superficial layer of paraffin and (4) a pond filled with hollow plastic cubes. Comparisons were made between these four ponds with and without plastic coverings, and with a layer of paraffin in addition on ponds 2 and 4. The rise in mean temperature of each pond during a number of heating cycles has been studied. A difference in mean temperature of the order of 10 to 20/sup 0/C was observed in each case between the beginning and end of the heating period and the temperature at the bottom of the pond after heating was in the range 30 to 50/sup 0/C. The results for these experimental ponds may be of use in the choice of full-size shallow ponds and may also give important indications for ponds of much greater depth.

  16. Thermal behavior of laboratory models of honeycomb-covered solar ponds

    Science.gov (United States)

    Lin, E. I. H.

    1983-01-01

    Laboratory experiments were conducted to provide insight into the technical feasibility of honeycomb-covered solar ponds. Cooling tests using honeycomb panels of various materials and geometries showed that a 5.7-cm-thick one-tier panel insulated as effectively as a 10-cm fiberglass slab. Heating tests demonstrated that a model pond covered with a polycarbonate panel boiled upon 16 hours of continuous exposure to a 150-W spotlight. Analysis of the experimental data indicates positively that honeycomb-covered solar ponds can be expected to perform satisfactorily, and that larger-scale outdoor tests should be conducted to provide a more realistic assessment and a more refined performance estimate.

  17. Evaluation of remedial alternatives for the Solar Ponds Plume, Rocky Flats Environmental Technology Site

    International Nuclear Information System (INIS)

    Hranac, K.C.

    1998-01-01

    This paper describes the process used to select a remedial alternative for handling contaminated groundwater emanating from the Solar Evaporation Ponds (Solar Ponds) at the Rocky Flats Environmental Technology Site (RFETS) and prevent it from reaching the nearest surface water body, North Walnut Creek. Preliminary results of field investigations conducted to provide additional information for the alternatives analysis are also presented. The contaminated groundwater is referred to as the Solar Ponds Plume (SPP). The primary contaminants in the SPP are nitrate and uranium; however, some metals exceed the site action levels at several locations and volatile organic compounds, originating from other sources, also have been detected. Currently the SPP, local surface water runoff, and infiltrated precipitation are collected by a trench system located downgradient of the Solar Ponds and pumped to three storage tanks. The water (two to three million gallons annually) is then pumped to an on-site treatment plant for evaporation at an approximate cost of $7.57 per liter

  18. Effects of salt pond restoration on benthic flux: Sediment as a source of nutrients to the water column

    Science.gov (United States)

    Topping, Brent R.; Kuwabara, James S.; Carter, James L.; Garrettt, Krista K.; Mruz, Eric; Piotter, Sarah; Takekawa, John Y.

    2016-01-01

    Understanding nutrient flux between the benthos and the overlying water (benthic flux) is critical to restoration of water quality and biological resources because it can represent a major source of nutrients to the water column. Extensive water management commenced in the San Francisco Bay, Beginning around 1850, San Francisco Bay wetlands were converted to salt ponds and mined extensively for more than a century. Long-term (decadal) salt pond restoration efforts began in 2003. A patented device for sampling porewater at varying depths, to calculate the gradient, was employed between 2010 and 2012. Within the former ponds, the benthic flux of soluble reactive phosphorus and that of dissolved ammonia were consistently positive (i.e., moving out of the sediment into the water column). The lack of measurable nitrate or nitrite concentration gradients across the sediment-water interface suggested negligible fluxes for dissolved nitrate and nitrite. The dominance of ammonia in the porewater indicated anoxic sediment conditions, even at only 1 cm depth, which is consistent with the observed, elevated sediment oxygen demand. Nearby openestuary sediments showed much lower benthic flux values for nutrients than the salt ponds under resortation. Allochthonous solute transport provides a nutrient advective flux for comparison to benthic flux. For ammonia, averaged for all sites and dates, benthic flux was about 80,000 kg/year, well above the advective flux range of −50 to 1500 kg/year, with much of the variability depending on the tidal cycle. By contrast, the average benthic flux of soluble reactive phosphorus was about 12,000 kg/year, of significant magnitude, but less than the advective flux range of 21,500 to 30,000 kg/year. These benthic flux estimates, based on solute diffusion across the sediment-water interface, reveal a significant nutrient source to the water column of the pond which stimulates algal blooms (often autotrophic). This benthic source may be

  19. Thermal performance of shallow solar pond under open cycle continuous flow heating mode for heat extraction

    Energy Technology Data Exchange (ETDEWEB)

    El-Sebaii, A.A. [Department of Physics, Faculty of Science, Tanta University, Tanta 31527 (Egypt)]. E-mail: aasebaii@yahoo.com; Aboul-Enein, S. [Department of Physics, Faculty of Science, Tanta University, Tanta 31527 (Egypt); Ramadan, M.R.I. [Department of Physics, Faculty of Science, Tanta University, Tanta 31527 (Egypt); Khallaf, A.M. [Department of Physics, Faculty of Science, Tanta University, Tanta 31527 (Egypt)

    2006-05-15

    The thermal performance of a shallow solar pond (SSP) under an open cycle continuous flow heating mode for heat extraction has been investigated. A serpentine heat exchanger (HE), either welded to the absorber plate or immersed in the pond water, has been used for extracting the heat. Suitable computer programs have been developed based on analytical solutions of the energy balance equations for the various elements of the SSP in the presence of the HE. Numerical calculations have been performed to study the effect of different operational and configurational parameters on the pond performance. In order to improve the pond performance, optimization of the various dimensions of the pond with the HE has been performed. The effects of the design parameters of the HE's tube, i.e. length L{sub he}, diameter D and mass flow rate m-bar {sub f} of the fluid flowing through the HE, on the pond performance have been investigated. The outlet temperature of the HE's fluid T{sub fo} is found to increase with increase of the HE length L{sub he}, and it decreases with increase of the mass flow rate of the HE's fluid m-bar {sub f} up to typical values for these parameters. Typical values for L{sub he} and m-bar {sub f} are found to be 4m and 0.004kg/s beyond which the change in T{sub fo} becomes insignificant. Experiments have been performed for the pond under different operational conditions with a HE welded to the absorber plate. To validate the proposed mathematical models, comparisons between experimental and theoretical results have been performed. Good agreement has been achieved.

  20. Power generation enhancement in a salinity-gradient solar pond power plant using thermoelectric generator

    International Nuclear Information System (INIS)

    Ziapour, Behrooz M.; Saadat, Mohammad; Palideh, Vahid; Afzal, Sadegh

    2017-01-01

    Highlights: • Thermoelectric generator was used and simulated within a salinity-gradient solar pond power plant. • Results showed that the thermoelectric generator can be able to enhance the power plant efficiency. • Results showed that the presented models can be able to produce generation even in the cold months. • The optimum size of area of solar pond based on its effect on efficiency is 50,000 m 2 . - Abstract: Salinity-gradient solar pond (SGSP) has been a reliable supply of heat source for power generation when it has been integrated with low temperature thermodynamics cycles like organic Rankine cycle (ORC). Also, thermoelectric generator (TEG) plays a critical role in the production of electricity from renewable energy sources. This paper investigates the potential of thermoelectric generator as a power generation system using heat from SGSP. In this work, thermoelectric generator was used instead of condenser of ORC with the purpose of improving the performance of system. Two new models of SGSP have been presented as: (1) SGSP using TEG in condenser of ORC without heat exchanger and (2) SGSP using TEG in condenser of ORC with heat exchanger. These proposed systems was evaluated through computer simulations. The ambient conditions were collected from beach of Urmia lake in IRAN. Simulation results indicated that, for identical conditions, the model 1 has higher performance than other model 2. For models 1 and 2 in T LCZ = 90 °C, the overall thermal efficiency of the solar pond power plant, were obtained 0.21% and 0.2% more than ORC without TEG, respectively.

  1. Don Quixote Pond: A Small Scale Model of Weathering and Salt Accumulation

    Science.gov (United States)

    Englert, P.; Bishop, J. L.; Patel, S. N.; Gibson, E. K.; Koeberl, C.

    2015-01-01

    The formation of Don Quixote Pond in the North Fork of Wright Valley, Antarctica, is a model for unique terrestrial calcium, chlorine, and sulfate weathering, accumulation, and distribution processes. The formation of Don Quixote Pond by simple shallow and deep groundwater contrasts more complex models for Don Juan Pond in the South Fork of Wright Valley. Our study intends to understand the formation of Don Quixote Pond as unique terrestrial processes and as a model for Ca, C1, and S weathering and distribution on Mars.

  2. Bacillus isabeliae sp. nov., a halophilic bacterium isolated from a sea salt evaporation pond.

    Science.gov (United States)

    Albuquerque, Luciana; Tiago, Igor; Taborda, Marco; Nobre, M Fernanda; Veríssimo, António; da Costa, Milton S

    2008-01-01

    A low-G+C, Gram-positive isolate, designated strain CVS-8(T), was isolated from a sea salt evaporation pond on the Island of Sal in the Cape Verde Archipelago. This organism was found to be a catalase- and oxidase-positive, non-motile, spore-forming, aerobic, curved rod-shaped organism with an optimum growth temperature of about 35-37 degrees C and an optimum pH between 7.5 and 8.0. Optimal growth occurred in media containing 4-6% (w/v) NaCl and no growth occurred in medium without NaCl. The cell-wall peptidoglycan was of the A1gamma type with meso-diaminopimelic acid, the major respiratory quinone was MK-7, the major fatty acids were iso-15:0, 16:0, anteiso-15:0 and iso-16:0 and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an unidentified aminoglycophospholipid. The G+C content of the DNA was 37.9 mol%. Phylogenetic analysis of the 16S rRNA gene sequence indicated that strain CVS-8(T) represented a novel species of the genus Bacillus, the highest levels of sequence similarity (mean pairwise similarity values of approximately 97.5 %) being found with respect to the type strains of Bacillus shackletonii and Bacillus acidicola. On the basis of the phylogenetic, physiological and biochemical data, strain CVS-8(T) represents a novel species of the genus Bacillus, for which the name Bacillus isabeliae sp. nov. is proposed. The type strain is CVS-8(T) (=LMG 22838(T)=CIP 108578(T)).

  3. Community solar salt production in Goa, India.

    Science.gov (United States)

    Mani, Kabilan; Salgaonkar, Bhakti B; Das, Deepthi; Bragança, Judith M

    2012-12-01

    Traditional salt farming in Goa, India has been practised for the past 1,500 years by a few communities. Goa's riverine estuaries, easy access to sea water and favourable climatic conditions makes salt production attractive during summer. Salt produced through this natural evaporation process also played an important role in the economy of Goa even during the Portuguese rule as salt was the chief export commodity. In the past there were 36 villages involved in salt production, which is now reduced to 9. Low income, lack of skilled labour, competition from industrially produced salt, losses incurred on the yearly damage of embankments are the major reasons responsible for the reduction in the number of salt pans.Salt pans (Mithagar or Mithache agor) form a part of the reclaimed waterlogged khazan lands, which are also utilised for aquaculture, pisciculture and agriculture. Salt pans in Goa experience three phases namely, the ceased phase during monsoon period of June to October, preparatory phase from December to January, and salt harvesting phase, from February to June. After the monsoons, the salt pans are prepared manually for salt production. During high tide, an influx of sea water occurs, which enters the reservoir pans through sluice gates. The sea water after 1-2 days on attaining a salinity of approximately 5ºBé, is released into the evaporator pans and kept till it attains a salinity of 23 - 25ºBé. The brine is then released to crystallizer pans, where the salt crystallises out 25 - 27ºBé and is then harvested.Salt pans form a unique ecosystem where succession of different organisms with varying environmental conditions occurs. Organisms ranging from bacteria, archaea to fungi, algae, etc., are known to colonise salt pans and may influence the quality of salt produced.The aim of this review is to describe salt farming in Goa's history, importance of salt production as a community activity, traditional method of salt production and the biota

  4. Different methods for modeling absorption heat transformer powered by solar pond

    International Nuclear Information System (INIS)

    Sencan, Arzu; Kizilkan, Onder; Bezir, Nalan C.; Kalogirou, Soteris A.

    2007-01-01

    Solar ponds are a type of solar collector used for storing solar energy at temperature below 90 o C. Absorption heat transformers (AHTs) are devices used to increase the temperature of moderately warm fluid to a more useful temperature level. In this study, a theoretical modelling of an absorption heat transformer for the temperature range obtained from an experimental solar pond with dimensions 3.5 x 3.5 x 2 m is presented. The working fluid pair in the absorption heat transformer is aqueous ternary hydroxide fluid consisting of sodium, potassium and caesium hydroxides in the proportions 40:36:24 (NaOH:KOH:CsOH). Different methods such as linear regression (LR), pace regression (PR), sequential minimal optimization (SMO), M5 model tree, M5' rules, decision table and back propagation neural network (BPNN) are used for modelling the absorption heat transformer. The best results were obtained by the back propagation neural network model. A new formulation based on the BPNN is presented to determine the flow ratio (FR) and the coefficient of performance (COP) of the absorption heat transformer. The BPNN procedure is more accurate and requires significantly less computation time than the other methods

  5. Salt Lake City, Utah: Solar in Action (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2011-10-01

    This brochure provides an overview of the challenges and successes of Salt Lake City, UT, a 2007 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  6. Development of a small-scale solar pond technology testbed for education purposes

    International Nuclear Information System (INIS)

    Rahmat, I.; Shazi, M.; Farizal, M.; Nor Azli; Fakhruldin M Hashim

    2006-01-01

    The search for clean energy sources that do not pollute have led researchers to test their ideas on a multitude of possible technology avenues. A number of these solutions rely on the sun. however, the initial financial investment required is great. These solutions, such as solar water heaters, depend on an insulated water tank to store the captured energy. A more effective device could be used to both capture and store copious amounts of sunlight energy, allowing almost continuous use even at night. Solar ponds show great promise in fulfilling this requirement. The one currently in operation at Universiti Teknologi PETRONAS is of the non-convecting type. It uses concentrated brine in the depths of the pond to capture solar energy. The energy is then trapped by the presence of a non-saline top layer, which insulates from convection heat losses. This phenomenon manifests itself as a rise in temperature of the brine. In this manner, thermal energy is contained in the pond, which can serve as the heat source for any appropriate power cycle or used for heating purposes. To make the technology feasible for education purposes it is imperative that its cost is lowered. The system is not dug out of the ground but uses a commercial bathtub to simulate the body of water. This method also greatly simplifies fabrication and maintenance. With this rudimentary setup, the highest temperature reached so far is 54 o C, achieved in a water depth of only 0.28 m. The next step is to increase the water depth, search for the most cost-effective side insulation and continue research into the appropriate energy extraction system to match the output and size of the solar pond. The main intent of this project is to educate students on this concept and develop it into an effective technology demonstrator. By keeping the cost low it can be turned into a viable secondary school Living Skills project to educate them on the potential of solar energy and the existence of alternative solutions in

  7. A THEORETICAL AND NUMERICAL STUDY OF THERMOSOLUTAL CONVECTION: STABILITY OF A SALINITY GRADIENT SOLAR POND

    Directory of Open Access Journals (Sweden)

    Djamel Kalache

    2011-01-01

    Full Text Available A theoretical and numerical study of the effect of thermodiffusion on the stability of a gradient layer is presented. It intends to clarify the mechanisms of fluid dynamics and the processes which occur in a salinity gradient solar pond. A mathematical modelling is developed to describe the thermodiffusion contribution on the solar pond where thermal, radiative, and massive fluxes are coupled in the double diffusion. More realistic boundary conditions for temperature and concentration profiles are used. Our results are compared with those obtained experimentally by authors without extracting the heat flux from the storage zone. We have considered the stability analysis of the equilibrium solution. We assumed that the perturbation of quantities such as velocity, temperature, and concentration are infinitesimal. Linearized equations satisfying appropriate prescribed boundary conditions are then obtained and expanded into polynomials form. The Galerkin method along with a symbolic algebra code (Maple are used to solve these equations. The effect of the separation coefficient y is analyzed in the positive and negative case. We have also numerically compared the critical Rayleigh numbers for the onset of convection with those obtained by the linear stability analysis for Le = 100, µa = 0.8, and f = 0.5.

  8. Achievement report for fiscal 1999 on project for supporting the formation of energy/environmental technology verification project. International joint verification research project (Study on an optimum heat and electricity supply system using a solar pond); 1999 nendo solar pond ni okeru saiteki netsuden kyokyu system no kenkyu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    This report covers the outcome of survey and research jointly conducted by a Russian research organization and a Japanese committee of experts. Concerning the present trend and the future outlook of the solar pond technology across the world, feasibility studies of Australia, America, Malaysia, Italy, etc., are presented. It is reported that a solar pond may be able to compete with other profitable power generation systems in terms of cost if advantageous siting conditions are available; that solar ponds are already in presence in Israel, America, Australia, India, etc.; but that none of them is commercially active on a large scale. In the evaluation of solar pond feasibility, various findings are obtained on solar pond performance characteristics through the examination of solar pond operating data supplied from the University of Texas, America. The findings are used in the evaluation of the siting cost in case one is to be installed in Russia and Japan. (NEDO)

  9. Evaluating the fisheries potential of solar salt works reservoirs at ...

    African Journals Online (AJOL)

    Artisanal fisheries are important livelihoods for coastal communities in many developing countries, where uncontrolled fishing can easily lead to depleted stocks in nearshore waters. Man-made reservoirs associated with solar salt works along the coast of Ungwana Bay provide alternative fishing grounds for local fishers ...

  10. Phase 1 studies summary of major findings of the South Bay Salt Pond Restoration Project, South San Francisco Bay, California

    Science.gov (United States)

    Valoppi, Laura

    2018-04-02

    Executive SummaryThe South Bay Salt Pond Restoration Project (Project) is one of the largest restoration efforts in the United States. It is located in South San Francisco Bay of California. It is unique not only for its size—more than 15,000 acres—but also for its location adjacent to one of the nation’s largest urban areas, home to more than 4 million people (Alameda, Santa Clara, and San Mateo Counties). The Project is intended to restore and enhance wetlands in South San Francisco Bay while providing for flood management, wildlife-oriented public access, and recreation. Restoration goals of the project are to provide a mosaic of saltmarsh habitat to benefit marsh species and managed ponds to benefit waterbirds, throughout 3 complexes and 54 former salt ponds.Although much is known about the project area, significant uncertainties remain with a project of this geographic and temporal scale of an estimated 50 years to complete the restoration. For example, in order to convert anywhere from 50 to 90 percent of the existing managed ponds to saltmarsh habitat, conservation managers first enhance the habitat of managed ponds in order to increase use by waterbirds, and provide migratory, wintering, and nesting habitat for more than 90 species of waterbirds. Project managers have concluded that the best way to address these uncertainties is to carefully implement the project in phases and learn from the outcome of each phase. The Adaptive Management Plan (AMP) identifies specific restoration targets for multiple aspects of the Project and defines triggers that would necessitate some type of management action if a particular aspect is trending negatively. U.S. Geological Survey (USGS) biologist Laura Valoppi served as the project Lead Scientist and oversaw implementation of the AMP in coordination with other members of the Project Management Team (PMT), comprised of representatives from the California State Coastal Conservancy, California Department of Fish and

  11. Egg production and hatching success of Paracartia grani (Copepoda, Calanoida, Acartiidae) in two hypersaline ponds of a Tunisian Solar Saltern

    Science.gov (United States)

    Annabi-Trabelsi, Neila; Rebai, Rayda Kobbi; Ali, Mohammad; Subrahmanyam, M. N. V.; Belmonte, Genuario; Ayadi, Habib

    2018-04-01

    Reproductive traits of Paracartia grani [percentage of spawning females, egg production rate (EPR), and hatching success (HS)] were investigated for the first time at high salinities (39-121 psu) to examine the impact of such a particular situation. The study was done in two hypersaline ponds [A1 (39-46 psu) and C31 (70-121 psu)] in Sfax Solar Saltern, central-eastern coast of Tunisia. These ponds also differed in terms of the composition and concentrations of nutritional parameters. The EPR differed significantly between the ponds (ANOVA, F = 29.45, p eggs female- 1 day- 1 (7 December 2009) and 14 ± 1 eggs female- 1 day- 1 (19 January 2010) with an average of 13.3 ± 0.44 eggs female- 1 day- 1. HS after 48 h of incubation were significantly higher than those after 24 h. The mean values of HS after 48 h were 42.72 ± 2.58% at pond A1 and 41.67 ± 3.92% at pond C31. The two peaks of HS (after 48 h) were observed at 15 °C in pond A1 (21 December 2009, 45.18% nauplii eggs- 1) and in C31 (4 January 2010, 48.78%) at the same temperature. This study confirms that a broad salinity tolerance allows P. grani to settle itself in environments, which are normally hostile to the development of other Acartiidae.

  12. Performance study of a laboratory model shallow solar pond with and without single transparent glass cover for solar thermal energy conversion applications.

    Science.gov (United States)

    Ganesh, S; Arumugam, S

    2016-12-01

    The thermal performance of a shallow solar pond with and without the single transparent glass cover has been investigated experimentally. This experiment has been performed during the summer season of 2014 under the operational condition for five different storage volumes of water upto a maximum of 10liter. The pond performance is investigated in terms of the rate of energy collected and its collection efficiency. A Low Density Polyethylene (LDPE) black sheet liner of 200μm thickness was laid on all the interior sides of the pond for solar energy absorption. A clear transparent PVC plastic sheet of 150μm thickness was laid over the water surface as evaporation suppressing membrane. Calibrated Copper constantan thermocouples were used to measure the temperatures of the system. A highest temperature of 81.5°C has been achieved for the stored volume of 2liter of water, when the pond was used with a single transparent glass cover of 5mm thickness. When the shallow solar pond was used without the transparent glass cover the system attained a maximum temperature of 62°C for the same stored volume of 2liter. A comparison between the two conditions of with and without the transparent glass cover, on the thermal performance of the SSP has been reported. A shallow solar pond system of the present type could be used us a source of warm water, of desired temperature, below 10°C which are required for the domestic and industrial utilities. The global warming is increased day by day; inorder to reduce global warming a typical method of small scale shallow solar pond has been used to absorb the radiation from the sun to convert it to useful heat energy by the source of water. The SSP is an eco friendly way to generate energy without polluting our environment and in an environment safety manner. Based on environmental safety this study has experimentally investigated the thermal performance of the shallow solar pond. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Artificial coastal lagoons at solar salt-working sites: A network of habitats for specialised, protected and alien biodiversity

    Science.gov (United States)

    Herbert, Roger J. H.; Broderick, Lee G.; Ross, Kathryn; Moody, Chris; Cruz, Tamira; Clarke, Leo; Stillman, Richard A.

    2018-04-01

    There are concerns that novel structures might displace protected species, facilitate the spread of non-indigenous species, or modify native habitats. It is also predicted that ocean warming and the associated effects of climate change will significantly increase biodiversity loss within coastal regions. Resilience is to a large extent influenced by the magnitude of dispersal and level of connectivity within and between populations. Therefore it is important to investigate the distribution and ecological significance of novel and artificial habitats, the presence of protected and alien species and potential vectors of propagule dispersal. The legacy of solar salt-making in tropical and warm temperate regions is regionally extensive areas of artificial hypersaline ponds, canals and ditches. Yet the broad-scale contribution of salt-working to a network of benthic biodiversity has not been fully established. Artisanal, abandoned and historic salt-working sites were investigated along the Atlantic coast of Europe between southern England (50°N) and Andalucía, Spain (36°N). Natural lagoons are scarce along this macrotidal coast and are vulnerable to environmental change; however it is suspected that avian propagule dispersal is important in maintaining population connectivity. During bird migration periods, benthic cores were collected for infauna from 70 waterbodies across 21 salt-working sites in 5 coastal regions. Bird ringing data were used to investigate potential avian connectivity between locations. Lagoonal specialist species, some of international conservation importance, were recorded across all regions in the storage reservoirs and evaporation ponds of continental salinas, yet few non-indigenous species were observed. Potential avian propagule transport and connectivity within and between extant salt-working sites is high and these artificial habitats are likely to contribute significantly to a network of coastal lagoon biodiversity in Europe.

  14. Experimental characterization of a solar cooker with thermal energy storage based on solar salt

    Science.gov (United States)

    Coccia, G.; Di Nicola, G.; Tomassetti, S.; Gabrielli, G.; Chieruzzi, M.; Pierantozzi, M.

    2017-11-01

    High temperature solar cooking allows to cook food fast and with good efficiency. An unavoidable drawback of this technology is that it requires nearly clear-sky conditions. In addition, evening cooking is difficult to be accomplished, particularly on the winter season during which solar radiation availability is limited to a few hours in the afternoon in most of countries. These restrictions could be overcome using a cooker thermal storage unit (TSU). In this work, a TSU based on solar salt was studied. The unit consists of two metal concentric cylindrical vessels, connected together to form a double-walled vessel. The volume between walls was filled with a certain amount of nitrate based phase change material (solar salt). In order to characterize the TSU, a test bench used to assess solar cooker performance was adopted. Experimental load tests with the TSU were carried out to evaluate the cooker performance. The obtained preliminary results show that the adoption of the solar salt TSU seems to allow both the opportunity of evening cooking and the possibility to better stabilize the cooker temperature when sky conditions are variable.

  15. Molten salt based nanofluids based on solar salt and alumina nanoparticles: An industrial approach

    Science.gov (United States)

    Muñoz-Sánchez, Belén; Nieto-Maestre, Javier; Guerreiro, Luis; Julia, José Enrique; Collares-Pereira, Manuel; García-Romero, Ana

    2017-06-01

    Thermal Energy Storage (TES) and its associated dispatchability is extremely important in Concentrated Solar Power (CSP) plants since it represents the main advantage of CSP technology in relation to other renewable energy sources like photovoltaic (PV). Molten salts are used in CSP plants as a TES material because of their high operational temperature and stability of up to 600°C. Their main problems are their relative poor thermal properties and energy storage density. A simple cost-effective way to improve the thermal properties of molten salts is to dope them with nanoparticles, thus obtaining the so-called salt-based nanofluids. Additionally, the use of molten salt based nanofluids as TES materials and Heat Transfer Fluid (HTF) has been attracting great interest in recent years. The addition of tiny amounts of nanoparticles to the base salt can improve its specific heat as shown by different authors1-3. The application of these nano-enhanced materials can lead to important savings on the investment costs in new TES systems for CSP plants. However, there is still a long way to go in order to achieve a commercial product. In this sense, the improvement of the stability of the nanofluids is a key factor. The stability of nanofluids will depend on the nature and size of the nanoparticles, the base salt and the interactions between them. In this work, Solar Salt (SS) commonly used in CSP plants (60% NaNO3 + 40% KNO3 wt.) was doped with alumina nanoparticles (ANPs) at a solid mass concentration of 1% wt. at laboratory scale. The tendency of nanoparticles to agglomeration and sedimentation is tested in the molten state by analyzing their size and concentration through the time. The specific heat of the nanofluid at 396 °C (molten state) is measured at different times (30 min, 1 h, 5 h). Further research is needed to understand the mechanisms of agglomeration. A good understanding of the interactions between the nanoparticle surface and the ionic media would provide

  16. 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…

  17. Rocky Flats Solar Evaporation Ponds RCRA hybrid-closure case study

    International Nuclear Information System (INIS)

    Ogg, R.T.; Everett, L.G.; Cullen, S.J.

    1994-01-01

    The Solar Evaporation Ponds (SEP)/Operable Unit 4 (OU 4), located at the Rocky Flats Plant (RFP) sixteen miles northwest of Denver, Colorado, is currently undergoing remediation/Resource Conservation and Recovery Act (RCRA) closure in accordance with the Rocky Flats Interagency Agreement (IAG) signed by the US Department of Energy (DOE), US Environmental Protection Agency (EPA) and Colorado Department of Health (CDH) on January 22, 1991. Based on the ''Phase 1'' (source and soils) RCRA Facility Investigation/Remedial Investigation (RFM data and interpretations), the DOE and EG and G Rocky Flats, Inc. (EG and G) have selected a permanent surface engineered/isolation barrier as the technological option for remediation of the SEP. The DOE and EG and G will utilize all natural materials to create an ''impermeable'' barrier/structure to isolate the waste being left in place from impacting human health and the environment for a minimum of 1,000 years. Their rationale for utilizing natural materials is two fold; (1) optimize long term performance of the barrier and; (2) design a structure which will be near maintenance free (passive remediation) for 1,000 years. The DOE and EG and G have taken a proactive approach in providing post closure performance assessment for this RCRA closure action. An integrated monitoring system has been designed which will include monitoring the engineered barrier, vadose zone and ground water systems. Rocky Flats will integrate instrumentation into the permanent engineered barrier which will provide early warning of potential liquid migration through the barrier and into the waste zone

  18. Salirhabdus euzebyi gen. nov., sp. nov., a Gram-positive, halotolerant bacterium isolated from a sea salt evaporation pond.

    Science.gov (United States)

    Albuquerque, Luciana; Tiago, Igor; Rainey, Fred A; Taborda, Marco; Nobre, M Fernanda; Veríssimo, António; da Costa, Milton S

    2007-07-01

    A low-G+C, Gram-positive bacterium, designated CVS-14(T), was recovered from a sea salt evaporation pond on the island of Sal in the Cape Verde Archipelago. This organism was catalase- and oxidase-positive. Cells were motile, spore-forming aerobic rods, with an optimum growth temperature of about 35-40 degrees C and optimum pH between 7.0 and 8.5. Optimal growth occurred in media containing 4-6 % (w/v) NaCl, although the organism was able to grow in medium without added NaCl and in medium containing 16 % NaCl. The cell-wall peptidoglycan was of A1 gamma type and the major respiratory quinone was menaquinone 7 (MK-7). Major fatty acids were iso-15 : 0, anteiso-15 : 0, iso-17 : 0 and anteiso-17 : 0. The DNA G+C content was 37.0 mol%. Phylogenetic analysis of the 16S rRNA gene sequence indicated that strain CVS-14(T) formed a distinct new branch within the radiation of the moderately halophilic bacilli group, forming a separate lineage from species of the genera Salinibacillus, Paucisalibacillus, Oceanobacillus, Lentibacillus and Virgibacillus. Strain CVS-14(T) showed 16S rRNA gene pairwise similarity values of approximately 95 % with species of the genus Salinibacillus. On the basis of morphological, physiological, chemotaxonomic and phylogenetic characteristics, strain CVS-14(T) is considered to represent a novel species in a new genus, for which the name Salirhabdus euzebyi gen. nov., sp. nov. is proposed. The type strain is CVS-14(T) (=LMG 22839(T)=CIP 108577(T)).

  19. Optimized molten salt receivers for ultimate trough solar fields

    Science.gov (United States)

    Riffelmann, Klaus-J.; Richert, Timo; Kuckelkorn, Thomas

    2016-05-01

    Today parabolic trough collectors are the most successful concentrating solar power (CSP) technology. For the next development step new systems with increased operation temperature and new heat transfer fluids (HTF) are currently developed. Although the first power tower projects have successfully been realized, up to now there is no evidence of an all-dominant economic or technical advantage of power tower or parabolic trough. The development of parabolic trough technology towards higher performance and significant cost reduction have led to significant improvements in competitiveness. The use of molten salt instead of synthetic oil as heat transfer fluid will bring down the levelized costs of electricity (LCOE) even further while providing dispatchable energy with high capacity factors. FLABEG has developed the Ultimate TroughTM (UT) collector, jointly with sbp Sonne GmbH and supported by public funds. Due to its validated high optical accuracy, the collector is very suitable to operate efficiently at elevated temperatures up to 550 °C. SCHOTT will drive the key-innovations by introducing the 4th generation solar receiver that addresses the most significant performance and cost improvement measures. The new receivers have been completely redesigned to provide a product platform that is ready for high temperature operation up to 550 °C. Moreover distinct product features have been introduced to reduce costs and risks in solar field assembly and installation. The increased material and design challenges incurred with the high temperature operation have been reflected in sophisticated qualification and validation procedures.

  20. Effect of solar radiation on the lipid characterization of biomass cultivated in high-rate algal ponds using domestic sewage.

    Science.gov (United States)

    Assemany, Paula Peixoto; Calijuri, Maria Lúcia; Santiago, Anibal da Fonseca; do Couto, Eduardo de Aguiar; Leite, Mauricio de Oliveira; Sierra, Jose Jovanny Bermudez

    2014-01-01

    The objective of this paper is to compare the lipid content and composition ofbiomass produced by a consortium of microalgae and bacteria, cultivated under different solar radiation intensities and tropical conditions in pilot-scale high-rate ponds (HRPs) using domestic sewage as culture medium. The treatment system consisted of an upflow anaerobic sludge blanket reactor followed by UV disinfection and six HRPs covered with shading screens that blocked 9%, 18%, 30%, 60% and 80% of the solar radiation. The total lipid content does not vary significantly among the units, showing a medium value of 9.5%. The results show that blocking over 30% of the solar radiation has a negative effect on the lipid productivity. The units with no shading and with 30% and 60% of solar radiation blocking have statistically significant lipid productivities, varying from 0.92 to 0.96 gm(-2) day(-1). Besides radiation, other variables such as volatile suspended solids and chlorophyll-a are able to explain the lipid accumulation. The lipid profile has a predominance of C16, C18:1 and C18:3 acids. The unsaturation of fatty acids increases with the reduction in solar radiation. On the other hand, the effect of polyunsaturation is not observed, which is probably due to the presence of a complex and diverse biomass.

  1. Steam generator design for solar towers using solar salt as heat transfer fluid

    Science.gov (United States)

    González-Gómez, Pedro Ángel; Petrakopoulou, Fontina; Briongos, Javier Villa; Santana, Domingo

    2017-06-01

    Since the operation of a concentrating solar power plant depends on the intermittent character of solar energy, the steam generator is subject to daily start-ups, stops and load variations. Faster start-up and load changes increase the plant flexibility and the daily energy production. However, it involves high thermal stresses on thick-walled components. Continuous operational conditions may eventually lead to a material failure. For these reasons, it is important to evaluate the transient behavior of the proposed designs in order to assure the reliability. The aim of this work is to analyze different steam generator designs for solar power tower plants using molten salt as heat transfer fluid. A conceptual steam generator design is proposed and associated heat transfer areas and steam drum size are calculated. Then, dynamic models for the main parts of the steam generator are developed to represent its transient performance. A temperature change rate that ensures safe hot start-up conditions is studied for the molten salt. The thermal stress evolution on the steam drum is calculated as key component of the steam generator.

  2. Seasonal changes in submarine groundwater discharge to coastal salt ponds estimated using 226Ra and 228Ra as tracers

    Science.gov (United States)

    Hougham, A.L.; Moran, S.B.; Masterson, J.P.; Kelly, R.P.

    2008-01-01

    Submarine groundwater discharge (SGD) to coastal southern Rhode Island was estimated from measurements of the naturally-occurring radioisotopes 226Ra (t1/2 = 1600??y) and 228Ra (t1/2 = 5.75??y). Surface water and porewater samples were collected quarterly in Winnapaug, Quonochontaug, Ninigret, Green Hill, and Pt. Judith-Potter Ponds, as well as nearly monthly in the surface water of Rhode Island Sound, from January 2002 to August 2003; additional porewater samples were collected in August 2005. Surface water activities ranged from 12-83??dpm 100??L- 1 (60??dpm = 1??Bq) and 21-256??dpm 100??L- 1 for 226Ra and 228Ra, respectively. Porewater 226Ra activities ranged from 16-736??dpm 100??L- 1 (2002-2003) and 95-815??dpm 100??L- 1 (2005), while porewater 228Ra activities ranged from 23-1265??dpm 100??L- 1. Combining these data with a simple box model provided average 226Ra-based submarine groundwater fluxes ranging from 11-159??L m- 2 d- 1 and average 228Ra-derived fluxes of 15-259??L m- 2 d- 1. Seasonal changes in Ra-derived SGD were apparent in all ponds as well as between ponds, with SGD values of 30-472??L m- 2 d- 1 (Winnapaug Pond), 6-20??L m- 2 d- 1 (Quonochontaug Pond), 36-273??L m- 2 d- 1 (Ninigret Pond), 29-76??L m- 2 d- 1 (Green Hill Pond), and 19-83??L m- 2 d- 1 (Pt. Judith-Potter Pond). These Ra-derived fluxes are up to two orders of magnitude higher than results predicted by a numerical model of groundwater flow, estimates of aquifer recharge for the study period, and values published in previous Ra-based SGD studies in Rhode Island. This disparity may result from differences in the type of flow (recirculated seawater versus fresh groundwater) determined using each technique, as well as variability in porewater Ra activity. ?? 2007 Elsevier B.V. All rights reserved.

  3. Domestic Material Content in Molten-Salt Concentrating Solar Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Turchi, Craig [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kurup, Parthiv [National Renewable Energy Lab. (NREL), Golden, CO (United States); Akar, Sertac [National Renewable Energy Lab. (NREL), Golden, CO (United States); Flores, Francisco [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-08-26

    This study lists material composition data for two concentrating solar power (CSP) plant designs: a molten-salt power tower and a hypothetical parabolic trough plant, both of which employ a molten salt for the heat transfer fluid (HTF) and thermal storage media. The two designs have equivalent generating and thermal energy storage capacities. The material content of the saltHTF trough plant was approximately 25% lower than a comparably sized conventional oil-HTF parabolic trough plant. The significant reduction in oil, salt, metal, and insulation mass by switching to a salt-HTF design is expected to reduce the capital cost and LCOE for the parabolic trough system.

  4. Chemical perspectives on alkali and earth alkaline nitrate and nitrite salts for concentrated solar power applications

    Energy Technology Data Exchange (ETDEWEB)

    Cordaro, Joseph G. [Sandia National Labsoratories, Livermore, CA (United States)

    2013-04-01

    Molten salts have been widely considered as the leading candidate heat transfer fluids (HTF) used in high temperature, concentrated solar power plants. Specifically, nitrate and nitrite based salts have been investigated as a HTF and even deployed in pilot plants generating up to 19.9 MW of electricity at operating temperatures above 500 C. New plant designs requiring higher operating temperatures for better efficiencies are pushing the stability limit of HTF. This paper presents an overview of the thermophysical properties of nitrate and nitrite salts and discusses thermodynamic and kinetic stability limitations as they relate to concentrated solar power generation. (orig.)

  5. Korean Solar Salt Ameliorates Colon Carcinogenesis in an AOM/DSS-Induced C57BL/6 Mouse Model.

    Science.gov (United States)

    Ju, Jaehyun; Kim, Yeung-Ju; Park, Eui Seong; Park, Kun-Young

    2017-06-01

    The effects of Korean solar salt on an azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced colon cancer C57BL/6 mouse model were studied. Korean solar salt samples (SS-S, solar salt from S salt field; SS-Yb, solar salt from Yb salt field), nine-time-baked bamboo salt (BS-9x, made from SS-Yb), purified salt (PS), and SS-G (solar salt from Guérande, France) were orally administered at a concentration of 1% during AOM/DSS colon cancer induction, and compared for their protective effects during colon carcinogenesis in C57BL/6 mice. SS-S and SS-Yb suppressed colon length shortening and tumor counts in mouse colons. Histological evaluation by hematoxylin and eosin staining also revealed suppression of tumorigenesis by SS-S. Conversely, PS and SS-G did not show a similar suppressive efficacy as Korean solar salt. SS-S and SS-Yb promoted colon mRNA expression of an apoptosis-related factor and cell-cycle-related gene and suppressed pro-inflammatory factor. SS-Yb baked into BS-9x further promoted these anti-carcinogenic efficacies. Taken together, the results indicate that Korean solar salt, especially SS-S and SS-Yb, exhibited anti-cancer activity by modulating apoptosis- and inflammation-related gene expression during colon carcinogenesis in mice, and bamboo salt baked from SS-Yb showed enhanced anti-cancer functionality.

  6. Water quality in South San Francisco Bay, California: current condition and potential issues for the South Bay Salt Pond Restoration Project.

    Science.gov (United States)

    Grenier, J Letitia; Davis, Jay A

    2010-01-01

    The SBSPRP is an extensive tidal wetland restoration project that is underway at the margin of South San Francisco Bay, California. The Project, which aims to restore former salt ponds to tidal marsh and manage other ponds for water bird support, is taking place in the context of a highly urbanized watershed and an Estuary already impacted by chemical contaminants. There is an intimate relationship between water quality in the watershed, the Bay, and the transitional wetland areas where the Project is located. The Project seeks to restore habitat for endangered and endemic species and to provide recreational opportunities for people. Therefore, water quality and bioaccumulation of contaminants in fish and wildlife is an important concern for the success of the Project. Mercury, PCBs, and PBDEs are the persistent contaminants of greatest concern in the region. All of these contaminants are present at elevated concentrations both in the abiotic environment and in wildlife. Dioxins, pyrethroids, PAHs, and selenium are also problematic. Organochlorine insecticides have historically impacted the Bay, and they remain above thresholds for concern in a small proportion of samples. Emerging contaminants, such as PFCs and non-PBDE flame retardants, are also an important water quality issue. Beyond chemical pollutants, other concerns for water quality in South San Francisco Bay exist, and include biological constituents, especially invasive species, and chemical attributes, such as dissolved oxygen and salinity. Future changes, both from within the Project and from the Bay and watershed, are likely to influence water quality in the region. Project actions to restore wetlands could worsen, improve, or not affect the already impaired water quality in South Bay. Accelerated erosion of buried sediment as a consequence of Project restoration actions is a potentially serious regional threat to South Bay water and sediment quality. Furthermore, the planned restoration of salt ponds

  7. Solar thermal technology report, FY 1981. Volume 1: Executive summary

    Science.gov (United States)

    1982-01-01

    The activities of the Department of Energy's Solar Thermal Technology Program are discussed. Highlights of technical activities and brief descriptions of each technology are given. Solar thermal conversion concepts are discussed in detail, particularily concentrating collectors and salt-gradient solar ponds.

  8. The Characteristic of Molten Heat Salt Storage System Utilizing Solar Energy Combined with Valley Electric

    Directory of Open Access Journals (Sweden)

    LI .Jiu-ru

    2017-02-01

    Full Text Available With the environmental pollution and energy consumption clue to the large difference between peak and valley of power grid,the molten salt heat storage system(MSHSS utilizing solar Energy combined with valley electric is presented for good energy saving and low emissions. The costs of MSHSS utilizing solar Energy combined with valley electric are greatly reduced. The law of heat transfer in molten salt heat storage technology is studied with the method of grey correlation analysis. The results show the effect of elbow sizes on surface convective heat transfer coefficient with different flow velocities.

  9. Methane-steam reforming by molten salt - membrane reactor using concentrated solar thermal energy

    International Nuclear Information System (INIS)

    Watanuki, K.; Nakajima, H.; Hasegawa, N.; Kaneko, H.; Tamaura, Y.

    2006-01-01

    By utilization of concentrated solar thermal energy for steam reforming of natural gas, which is an endothermic reaction, the chemical energy of natural gas can be up-graded. The chemical system for steam reforming of natural gas with concentrated solar thermal energy was studied to produce hydrogen by using the thermal storage with molten salt and the membrane reactor. The original steam reforming module with hydrogen permeable palladium membrane was developed and fabricated. Steam reforming of methane proceeded with the original module with palladium membrane below the decomposition temperature of molten salt (around 870 K). (authors)

  10. Latent energy storage with salt and metal mixtures for solar dynamic applications

    Science.gov (United States)

    Crane, R. A.; Konstantinou, K. S.

    1988-01-01

    This paper examines three design alternatives for the development of a solar dynamic heat receiver as applied to power systems operating in low earth orbit. These include a base line design used for comparison in ongoing NASA studies, a system incorporating a salt energy storage system with the salt dispersed within a metal mesh and a hybrid system incorporating both a molten salt and molten metal for energy storage. Based on a typical low earth orbit condition, designs are developed and compared to determine the effect of resultant conductivity, heat capacity and heat of fusion on system size, weight, temperature gradients, cycle turbine inlet temperature and material utilization.

  11. Solar gasification of biomass: design and characterization of a molten salt gasification reactor

    Science.gov (United States)

    Hathaway, Brandon Jay

    The design and implementation of a prototype molten salt solar reactor for gasification of biomass is a significant milestone in the development of a solar gasification process. The reactor developed in this work allows for 3 kWth operation with an average aperture flux of 1530 suns at salt temperatures of 1200 K with pneumatic injection of ground or powdered dry biomass feedstocks directly into the salt melt. Laboratory scale experiments in an electrically heated reactor demonstrate the benefits of molten salt and the data was evaluated to determine the kinetics of pyrolysis and gasification of biomass or carbon in molten salt. In the presence of molten salt overall gas yields are increased by up to 22%; pyrolysis rates double due to improved heat transfer, while carbon gasification rates increase by an order of magnitude. Existing kinetic models for cellulose pyrolysis fit the data well, while carbon gasification in molten salt follows kinetics modeled with a 2/3 order shrinking-grain model with a pre-exponential factor of 1.5*106 min-1 and activation energy of 158 kJ/mol. A reactor concept is developed based around a concentric cylinder geometry with a cavity-style solar receiver immersed within a volume of molten carbonate salt. Concentrated radiation delivered to the cavity is absorbed in the cavity walls and transferred via convection to the salt volume. Feedstock is delivered into the molten salt volume where biomass gasification reactions will be carried out producing the desired product gas. The features of the cavity receiver/reactor concept are optimized based on modeling of the key physical processes. The cavity absorber geometry is optimized according to a parametric survey of radiative exchange using a Monte Carlo ray tracing model, resulting in a cavity design that achieves absorption efficiencies of 80%-90%. A parametric survey coupling the radiative exchange simulations to a CFD model of molten salt natural convection is used to size the annulus

  12. Evaluation of social attraction measures to establish Forster’s tern (Sterna forsteri) nesting colonies for the South Bay Salt Pond Restoration Project, San Francisco Bay, California—2017 Annual Report

    Science.gov (United States)

    Hartman, C. Alex; Ackerman, Joshua T.; Herzog, Mark P.; Wang, Yiwei; Strong, Cheryl

    2018-05-31

    Forster’s terns (Sterna forsteri), historically one of the most numerous colonial-breeding waterbirds in South San Francisco Bay, California, have had recent decreases in the number of nesting colonies and overall breeding population size. The South Bay Salt Pond (SBSP) Restoration Project aims to restore 50–90 percent of former salt evaporation ponds to tidal marsh habitat in South San Francisco Bay. This restoration will remove much of the historical island nesting habitat used by Forster’s terns, American avocets (Recurvirostra americana), and other waterbirds. To address this issue, the SBSP Restoration Project organized the construction of new nesting islands in managed ponds that will not be restored to tidal marsh, thereby providing enduring island nesting habitat for waterbirds. In 2012, 16 new islands were constructed in Pond A16 in the Alviso complex of the Don Edwards San Francisco Bay National Wildlife Refuge, increasing the number of islands in this pond from 4 to 20. However, despite a history of nesting on the four historical islands in Pond A16 before 2012, no Forster’s terns have nested in Pond A16 since the new islands were constructed.In 2017, we used social attraction measures (decoys and electronic call systems) to attract Forster’s terns to islands within Pond A16 to re-establish nesting colonies. We maintained these systems from March through August 2017. To evaluate the effect of these social attraction measures, we also completed waterbird surveys between April and August, where we recorded the number and location of all Forster’s terns and other waterbirds using Pond A16, and monitored waterbird nests. We compared bird survey and nest monitoring data collected in 2017 to data collected in 2015 and 2016, prior to the implementation of social attraction measures, allowing for direct evaluation of social attraction efforts on Forster’s terns.To increase the visibility and stakeholder involvement of this project, we engaged in

  13. Thermodynamics investigation of a solar power system integrated oil and molten salt as heat transfer fluids

    International Nuclear Information System (INIS)

    Liu, Qibin; Bai, Zhang; Sun, Jie; Yan, Yuejun; Gao, Zhichao; Jin, Hongguang

    2016-01-01

    Highlights: • A new concentrating solar power system with a dual-solar field is proposed. • The superheated steam with more than 773 K is produced. • The performances of the proposed system are demonstrated. • The economic feasibility of the proposed system is validated. - Abstract: In this paper, a new parabolic trough solar power system that incorporates a dual-solar field with oil and molten salt as heat transfer fluids (HTFs) is proposed to effectively utilize the solar energy. The oil is chosen as a HTF in the low temperature solar field to heat the feeding water, and the high temperature solar field uses molten salt to superheat the steam that the temperature is higher than 773 K. The produced superheated steam enters a steam turbine to generate power. Energy analysis and exergy analysis of the system are implemented to evaluate the feasibility of the proposed system. Under considerations of variations of solar irradiation, the on-design and off-design thermodynamic performances of the system and the characteristics are investigated. The annual average solar-to-electric efficiency and the nominal efficiency under the given condition for the proposed solar thermal power generation system reach to 15.86% and 22.80%, which are higher than the reference system with a single HTF. The exergy losses within the solar heat transfer process of the proposed system are reduced by 7.8% and 45.23% compared with the solar power thermal systems using oil and molten salt as HTFs, respectively. The integrated approach with oil and molten salt as HTFs can make full use of the different physical properties of the HTFs, and optimize the heat transfer process between the HTFs and the water/steam. The exergy loss in the water evaporation and superheated process are reduced, the system efficiency and the economic performance are improved. The research findings provide a new approach for the improvement of the performances of solar thermal power plants.

  14. Compatibility tests between Solar Salt and thermal storage ceramics from inorganic industrial wastes

    International Nuclear Information System (INIS)

    Motte, Fabrice; Falcoz, Quentin; Veron, Emmanuel; Py, Xavier

    2015-01-01

    Highlights: • ESEM and XRD characterizations have been performed. • Compatibility of these ceramics with the conventional binary Solar Salt is tested at 500 °C. • Tested ceramics have relevant properties to store thermal energy up to 1000 °C. • Feasibility of using ceramics as filler materials in thermocline is demonstrated. - Abstract: This paper demonstrates the feasibility of using several post-industrial ceramics as filler materials in a direct thermocline storage configuration. The tested ceramics, coming from several industrial processes (asbestos containing waste treatment, coal fired power plants or metallurgic furnaces) demonstrate relevant properties to store thermal energy by sensible heat up to 1000 °C. Thus, they represent at low-cost a promising, efficient and sustainable approach for thermal energy storage. In the present study, the thermo-chemical compatibility of these ceramics with the conventional binary Solar Salt is tested at medium temperature (500 °C) under steady state. In order to determine the feasibility of using such ceramics as filler material, Environmental Scanning Electron Microscopy (ESEM) and X-Ray Diffraction (XRD) characterizations have been performed to check for their chemical and structural evolution during corrosion tests. The final objective is to develop a molten salt thermocline direct storage system using low-cost shaped ceramic as structured filler material. Most of the tested ceramics present an excellent corrosion resistance in molten Solar Salt and should significantly decrease the current cost of concentrated solar thermal energy storage system

  15. High-temperature molten salt thermal energy storage systems for solar applications

    Science.gov (United States)

    Petri, R. J.; Claar, T. D.; Ong, E.

    1983-01-01

    Experimental results of compatibility screening studies of 100 salt/containment/thermal conductivity enhancement (TCE) combinations for the high temperature solar thermal application range of 704 deg to 871 C (1300 to 1600 F) are presented. Nine candidate containment/HX alloy materials and two TCE materials were tested with six candidate solar thermal alkali and alkaline earth carbonate storage salts (both reagent and technical grade of each). Compatibility tests were conducted with salt encapsulated in approx. 6.0 inch x 1 inch welded containers of test material from 300 to 3000 hours. Compatibility evaluations were end application oriented, considering the potential 30 year lifetime requirement of solar thermal power plant components. Analyses were based on depth and nature of salt side corrosion of materials, containment alloy thermal aging effects, weld integrity in salt environment, air side containment oxidation, and chemical and physical analyses of the salt. A need for more reliable, and in some cases first time determined thermophysical and transport property data was also identified for molten carbonates in the 704 to 871 C temperature range. In particular, accurate melting point (mp) measurements were performed for Li2CO3 and Na2CO3 while melting point, heat of fusion, and specific heat determinations were conducted on 81.3 weight percent Na2CO3-18.7 weight percent K2CO3 and 52.2 weight percent BaCO3-47.8 weight percent Na2CO3 to support future TES system design and ultimate scale up of solar thermal energy storage (TES) subsystems.

  16. Molten Salt-Carbon Nanotube Thermal Energy Storage for Concentrating Solar Power Systems Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Michael Schuller; Frank Little; Darren Malik; Matt Betts; Qian Shao; Jun Luo; Wan Zhong; Sandhya Shankar; Ashwin Padmanaban

    2012-03-30

    We demonstrated that adding nanoparticles to a molten salt would increase its utility as a thermal energy storage medium for a concentrating solar power system. Specifically, we demonstrated that we could increase the specific heat of nitrate and carbonate salts containing 1% or less of alumina nanoparticles. We fabricated the composite materials using both evaporative and air drying methods. We tested several thermophysical properties of the composite materials, including the specific heat, thermal conductivity, latent heat, and melting point. We also assessed the stability of the composite material with repeated thermal cycling and the effects of adding the nanoparticles on the corrosion of stainless steel by the composite salt. Our results indicate that stable, repeatable 25-50% improvements in specific heat are possible for these materials. We found that using these composite salts as the thermal energy storage material for a concentrating solar thermal power system can reduce the levelized cost of electricity by 10-20%. We conclude that these materials are worth further development and inclusion in future concentrating solar power systems.

  17. Economic Optimization of a Concentrating Solar Power Plant with Molten-salt Thermocline Storage

    OpenAIRE

    Flueckiger, S. M.; Iverson, B. D.; Garimella, S V

    2014-01-01

    System-level simulation of a molten-salt thermocline tank is undertaken in response to year-long historical weather data and corresponding plant control. Such a simulation is enabled by combining a finite-volume model of the tank that includes a sufficiently faithful representation at low computation cost with a system-level power tower plant model. Annual plant performance of a 100 MWe molten-salt power tower plant is optimized as a function of the thermocline tank size and the plant solar m...

  18. Computational Analysis of Nanoparticles-Molten Salt Thermal Energy Storage for Concentrated Solar Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Vinod [Univ. of Texas, El Paso, TX (United States)

    2017-05-05

    High fidelity computational models of thermocline-based thermal energy storage (TES) were developed. The research goal was to advance the understanding of a single tank nanofludized molten salt based thermocline TES system under various concentration and sizes of the particles suspension. Our objectives were to utilize sensible-heat that operates with least irreversibility by using nanoscale physics. This was achieved by performing computational analysis of several storage designs, analyzing storage efficiency and estimating cost effectiveness for the TES systems under a concentrating solar power (CSP) scheme using molten salt as the storage medium. Since TES is one of the most costly but important components of a CSP plant, an efficient TES system has potential to make the electricity generated from solar technologies cost competitive with conventional sources of electricity.

  19. Response surface methodology modeling to improve degradation of Chlorpyrifos in agriculture runoff using TiO2 solar photocatalytic in a raceway pond reactor.

    Science.gov (United States)

    Amiri, Hoda; Nabizadeh, Ramin; Silva Martinez, Susana; Jamaleddin Shahtaheri, Seyed; Yaghmaeian, Kamyar; Badiei, Alireza; Nazmara, Shahrokh; Naddafi, Kazem

    2018-01-01

    This paper deals with the use of a raceway pond reactor (RPR) as an alternative photoreactor for solar photocatalytic applications. Raceway pond reactors are common low-cost reactors which can treat large volumes of water. The experiments were carried out with TiO 2 in the agriculture effluent spiked with Chlorpyrifos (CPF) at circumneutral pH. The Response Surface Methodology (RSM) was used to find the optimum process parameters to maximize CPF oxidation from the mathematical model equations developed in this study using R software. By ANOVA, p-value of lack of fit > 0.05 indicated that, the equation was well-fitted. The theoretical efficiency of CPF removal, under the optimum oxidation conditions with UV solar energy of around 697 ± 5.33 lux, was 84.01%, which is in close agreement with the mean experimental value (80 ± 1.42%) confirming that the response model was suitable for the optimization. As far as the authors know, this is the first study of CPF removal using RPR in agriculture runoff at circumneutral pH. Copyright © 2017. Published by Elsevier Inc.

  20. Spatial modeling of limnological parameters in a solar saltwork of northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Diógenes Félix da Silva Costa

    2015-03-01

    Full Text Available AimIn this research, we aimed to model limnological parameters in the Salina Unidos (Macau-Brazil using GIS technology. We hypothesized that in solar saltworks, the geochemical characteristics of the brines (i.e. the strong solution of salts vary considerably through the salt ponds circuit, in which drastic changes can damage the entire salt production.MethodsGeochemical parameters were monitored in seven sampling points distributed along the salt ponds circuit, during a complete cycle of salt production, i.e., from January to December 2007. The open source software Spring 5.1.6 was used to build, store, analyze and model the spatial distribution of the parameters.ResultsWe identified a spatial gradient of the salinity and temperature, with values increasing from evaporation ponds to concentration ponds, showing a relationship with the salt production. The parameters, depth, dissolved oxygen concentrations and total dissolved reactive phosphorus showed a decrease from the evaporation ponds towards the concentration ponds. Among the dissolved inorganic nitrogen forms analyzed (NH3-, NO2- and NO3-, nitrate was the predominant, namely in the concentration ponds, where it reached the highest concentrations. The concentration of chlorophyll awas higher in the initial and intermediate evaporation ponds, showing a distinct dynamics of in relation to other environmental variables.ConclusionsThe increased concentration of the analyzed limnological parameters, from the evaporation ponds towards the concentration ponds, evidenced a heterogeneous distribution varying significantly with season. The geochemical spatialization of brine, as illustrated by GIS approach, is very important for the conservation of these environments because this spatial heterogeneity can provide a high diversity of habitat types. This spatial analysis proved to be a practical tool for an adequate management of solar saltworks considering the environmental (ecosystem and the socio

  1. Renewable and high efficient syngas production from carbon dioxide and water through solar energy assisted electrolysis in eutectic molten salts

    KAUST Repository

    Wu, Hongjun; Liu, Yue; Ji, Deqiang; Li, Zhida; Yi, Guanlin; Yuan, Dandan; Wang, Baohui; Zhang, Zhonghai; Wang, Peng

    2017-01-01

    sustainable energy sources: concentrated solar light heats molten salt and solar cell supplies electricity for electrolysis. The eutectic Li0.85Na0.61K0.54CO3/nLiOH molten electrolyte is rationally designed with low melting point (<450 °C). The synthesized

  2. Increment of specific heat capacity of solar salt with SiO2 nanoparticles.

    Science.gov (United States)

    Andreu-Cabedo, Patricia; Mondragon, Rosa; Hernandez, Leonor; Martinez-Cuenca, Raul; Cabedo, Luis; Julia, J Enrique

    2014-01-01

    Thermal energy storage (TES) is extremely important in concentrated solar power (CSP) plants since it represents the main difference and advantage of CSP plants with respect to other renewable energy sources such as wind, photovoltaic, etc. CSP represents a low-carbon emission renewable source of energy, and TES allows CSP plants to have energy availability and dispatchability using available industrial technologies. Molten salts are used in CSP plants as a TES material because of their high operational temperature and stability of up to 500°C. Their main drawbacks are their relative poor thermal properties and energy storage density. A simple cost-effective way to improve thermal properties of fluids is to dope them with nanoparticles, thus obtaining the so-called salt-based nanofluids. In this work, solar salt used in CSP plants (60% NaNO3 + 40% KNO3) was doped with silica nanoparticles at different solid mass concentrations (from 0.5% to 2%). Specific heat was measured by means of differential scanning calorimetry (DSC). A maximum increase of 25.03% was found at an optimal concentration of 1 wt.% of nanoparticles. The size distribution of nanoparticle clusters present in the salt at each concentration was evaluated by means of scanning electron microscopy (SEM) and image processing, as well as by means of dynamic light scattering (DLS). The cluster size and the specific surface available depended on the solid content, and a relationship between the specific heat increment and the available particle surface area was obtained. It was proved that the mechanism involved in the specific heat increment is based on a surface phenomenon. Stability of samples was tested for several thermal cycles and thermogravimetric analysis at high temperature was carried out, the samples being stable. 65.: Thermal properties of condensed matter; 65.20.-w: Thermal properties of liquids; 65.20.Jk: Studies of thermodynamic properties of specific liquids.

  3. In Situ Production of Copper Oxide Nanoparticles in a Binary Molten Salt for Concentrated Solar Power Plant Applications.

    Science.gov (United States)

    Lasfargues, Mathieu; Stead, Graham; Amjad, Muhammad; Ding, Yulong; Wen, Dongsheng

    2017-05-19

    Seeding nanoparticles in molten salts has been shown recently as a promising way to improve their thermo-physical properties. The prospect of such technology is of interest to both academic and industrial sectors in order to enhance the specific heat capacity of molten salt. The latter is used in concentrated solar power plants as both heat transfer fluid and sensible storage. This work explores the feasibility of producing and dispersing nanoparticles with a novel one pot synthesis method. Using such a method, CuO nanoparticles were produced in situ via the decomposition of copper sulphate pentahydrate in a KNO₃-NaNO₃ binary salt. Analyses of the results suggested preferential disposition of atoms around produced nanoparticles in the molten salt. Thermal characterization of the produced nano-salt suspension indicated the dependence of the specific heat enhancement on particle morphology and distribution within the salts.

  4. In Situ Production of Copper Oxide Nanoparticles in a Binary Molten Salt for Concentrated Solar Power Plant Applications

    Directory of Open Access Journals (Sweden)

    Mathieu Lasfargues

    2017-05-01

    Full Text Available Seeding nanoparticles in molten salts has been shown recently as a promising way to improve their thermo-physical properties. The prospect of such technology is of interest to both academic and industrial sectors in order to enhance the specific heat capacity of molten salt. The latter is used in concentrated solar power plants as both heat transfer fluid and sensible storage. This work explores the feasibility of producing and dispersing nanoparticles with a novel one pot synthesis method. Using such a method, CuO nanoparticles were produced in situ via the decomposition of copper sulphate pentahydrate in a KNO3-NaNO3 binary salt. Analyses of the results suggested preferential disposition of atoms around produced nanoparticles in the molten salt. Thermal characterization of the produced nano-salt suspension indicated the dependence of the specific heat enhancement on particle morphology and distribution within the salts.

  5. Frozen ponds

    DEFF Research Database (Denmark)

    Langer, M; Westermann, S.; Anthony, K. Walter

    2015-01-01

    to a warming climate are complex and only poorly understood. Small waterbodies have been attracting an increasing amount of attention since recent studies demonstrated that ponds can make a significant contribution to the CO2 and CH4emissions of tundra ecosystems. Waterbodies also have a marked effect...... on the thermal state of the surrounding permafrost; during the freezing period they prolong the period of time during which thawed soil material is available for microbial decomposition.  This study presents net CH4 production rates during the freezing period from ponds within a typical lowland tundra landscape...

  6. Gas Turbine/Solar Parabolic Trough Hybrid Design Using Molten Salt Heat Transfer Fluid: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Turchi, C. S.; Ma, Z.

    2011-08-01

    Parabolic trough power plants can provide reliable power by incorporating either thermal energy storage (TES) or backup heat from fossil fuels. This paper describes a gas turbine / parabolic trough hybrid design that combines a solar contribution greater than 50% with gas heat rates that rival those of natural gas combined-cycle plants. Previous work illustrated benefits of integrating gas turbines with conventional oil heat-transfer-fluid (HTF) troughs running at 390?C. This work extends that analysis to examine the integration of gas turbines with salt-HTF troughs running at 450 degrees C and including TES. Using gas turbine waste heat to supplement the TES system provides greater operating flexibility while enhancing the efficiency of gas utilization. The analysis indicates that the hybrid plant design produces solar-derived electricity and gas-derived electricity at lower cost than either system operating alone.

  7. Development of Molten-Salt Heat Transfer Fluid Technology for Parabolic Trough Solar Power Plants - Public Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Grogan, Dylan C. P.

    2013-08-15

    Executive Summary This Final Report for the "Development of Molten-Salt Heat Transfer Fluid (HTF) Technology for Parabolic Trough Solar Power Plants” describes the overall project accomplishments, results and conclusions. Phase 1 analyzed the feasibility, cost and performance of a parabolic trough solar power plant with a molten salt heat transfer fluid (HTF); researched and/or developed feasible component options, detailed cost estimates and workable operating procedures; and developed hourly performance models. As a result, a molten salt plant with 6 hours of storage was shown to reduce Thermal Energy Storage (TES) cost by 43.2%, solar field cost by 14.8%, and levelized cost of energy (LCOE) by 9.8% - 14.5% relative to a similar state-of-the-art baseline plant. The LCOE savings range met the project’s Go/No Go criteria of 10% LCOE reduction. Another primary focus of Phase 1 and 2 was risk mitigation. The large risk areas associated with a molten salt parabolic trough plant were addressed in both Phases, such as; HTF freeze prevention and recovery, collector components and piping connections, and complex component interactions. Phase 2 analyzed in more detail the technical and economic feasibility of a 140 MWe,gross molten-salt CSP plant with 6 hours of TES. Phase 2 accomplishments included developing technical solutions to the above mentioned risk areas, such as freeze protection/recovery, corrosion effects of applicable molten salts, collector design improvements for molten salt, and developing plant operating strategies for maximized plant performance and freeze risk mitigation. Phase 2 accomplishments also included developing and thoroughly analyzing a molten salt, Parabolic Trough power plant performance model, in order to achieve the project cost and performance targets. The plant performance model and an extensive basic Engineering, Procurement, and Construction (EPC) quote were used to calculate a real levelized cost of energy (LCOE) of 11.50

  8. A rational approach for evaluation and screening of treatment and disposal options for the solar pond sludges at Rocky Flats

    International Nuclear Information System (INIS)

    Dickerson, K.S.

    1995-01-01

    This document consists of information about the treatment options for the sludge that is located in the evaporation ponds at the Rocky Flats Plant. The sludges are mixed low-level radioactive wastes whose composition and character were variable. Sludges similar to these are typically treated prior to ultimate disposal. Disposal of treated sludges includes both on-site and off-site options. The rational approach described in this paper is useful for technology evaluation and screening because it provides a format for developing objectives, listing alternatives, and weighing the alternatives against the objectives and against each other

  9. A rational approach for evaluation and screening of treatment and disposal options for the solar pond sludges at Rocky Flats

    Energy Technology Data Exchange (ETDEWEB)

    Dickerson, K.S.

    1995-12-31

    This document consists of information about the treatment options for the sludge that is located in the evaporation ponds at the Rocky Flats Plant. The sludges are mixed low-level radioactive wastes whose composition and character were variable. Sludges similar to these are typically treated prior to ultimate disposal. Disposal of treated sludges includes both on-site and off-site options. The rational approach described in this paper is useful for technology evaluation and screening because it provides a format for developing objectives, listing alternatives, and weighing the alternatives against the objectives and against each other.

  10. Emission of Volatile OrganoHalogens by Southern African Solar Salt Works

    Science.gov (United States)

    Kotte, Karsten; Weissflog, Ludwig; Lange, Christian Albert; Huber, Stefan; Pienaar, Jacobus J.

    2010-05-01

    Volatile organic compounds containing halogens - especially chlorine - have been considered for a long time of industrial origin only, and it was assumed that the production and emission of these compounds can easily be controlled by humans in case they will cause a threat for life on Earth. Since the middle of the 80ies of the last century it became clear that the biologically active organohalogens isolated by chemists are purposefully produced by nature as antibiotics or as antifeedant etc. To date more than 3800 organohalogens are known to be naturally produced by bio-geochemical processes. The global budgets of many such species are poorly understood and only now with the emergence of better analytical techniques being discovered. For example the compound chloromethane nature's production (5 GT) outdates the anthropogenic production (50 KT) by a factor of 100. Thus organohalogens are an interesting recent case in point since they can influence the ozone budget of the boundary layer, play a role in the production of aerosols and the climate change discussion. An intriguing observation is that most of the atmospheric CH3Cl and CH3Br are of terrestrial rather than of marine origin and that a number of halogenated small organic molecules are produced in soils. The high concentrations of halides in salt soils point to a possibly higher importance of natural halogenation processes as a source of volatile organohalogens. Terrestrial biota, such as fungi, plants, animals and insects, as well as marine algea, bacteria and archaea are known or suspected to be de-novo producers of volatile organohalogens. In recent years we revealed the possibility for VOX to form actively in water and bottom sediments of hyper-saline environments in the course of studying aridization processes during climatic warming. Due to the nature of their production process solar salt works, as to be found along-side the Southern African coast line but also upcountry, combine a variety of semi- and

  11. Preparation and characterization of molten salt based nanothermic fluids with enhanced thermal properties for solar thermal applications

    International Nuclear Information System (INIS)

    Madathil, Pramod Kandoth; Balagi, Nagaraj; Saha, Priyanka; Bharali, Jitalaxmi; Rao, Peddy V.C.; Choudary, Nettem V.; Ramesh, Kanaparthi

    2016-01-01

    Highlights: • Prepared and characterized inorganic ternary molten salt based nanothermic fluids. • MoS_2 and CuO nanoparticles incorporated ternary molten salts have been prepared. • Thermal properties enhanced by the addition of MoS_2 and CuO nanoparticles. • The amount of nanoparticles has been optimized. - Abstract: In the current energy scenario, solar energy is attracting considerable attention as a renewable energy source with ample research and commercial opportunities. The novel and efficient technologies in the solar energy are directed to develop methods for solar energy capture, storage and utilization. High temperature thermal energy storage systems can deal with a wide range of temperatures and therefore they are highly recommended for concentrated solar power (CSP) applications. In the present study, a systematic investigation has been carried out to identify the suitable inorganic nanoparticles and their addition in the molten salt has been optimized. In order to enhance the thermo-physical properties such as thermal conductivity and specific heat capacity of molten salt based HTFs, we report the utilization of MoS_2 and CuO nanoparticles. The enhancement in the above mentioned thermo-physical properties has been demonstrated for optimized compositions and the morphologies of nanoparticle-incorporated molten salts have been studied by scanning electron microscopy (SEM). Nanoparticle addition to molten salts is an efficient method to prepare thermally stable molten salt based heat transfer fluids which can be used in CSP plants. It is also observed that the sedimentation of nanoparticles in molten salt is negligible compared to that in organic heat transfer fluids.

  12. Heat Transfer and Latent Heat Storage in Inorganic Molten Salts for Concentrating Solar Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Mathur, Anoop [Terrafore Inc.

    2013-08-14

    A key technological issue facing the success of future Concentrating Solar Thermal Power (CSP) plants is creating an economical Thermal Energy Storage (TES) system. Current TES systems use either sensible heat in fluids such as oil, or molten salts, or use thermal stratification in a dual-media consisting of a solid and a heat-transfer fluid. However, utilizing the heat of fusion in inorganic molten salt mixtures in addition to sensible heat , as in a Phase change material (PCM)-based TES, can significantly increase the energy density of storage requiring less salt and smaller containers. A major issue that is preventing the commercial use of PCM-based TES is that it is difficult to discharge the latent heat stored in the PCM melt. This is because when heat is extracted, the melt solidifies onto the heat exchanger surface decreasing the heat transfer. Even a few millimeters of thickness of solid material on heat transfer surface results in a large drop in heat transfer due to the low thermal conductivity of solid PCM. Thus, to maintain the desired heat rate, the heat exchange area must be large which increases cost. This project demonstrated that the heat transfer coefficient can be increase ten-fold by using forced convection by pumping a hyper-eutectic salt mixture over specially coated heat exchanger tubes. However,only 15% of the latent heat is used against a goal of 40% resulting in a projected cost savings of only 17% against a goal of 30%. Based on the failure mode effect analysis and experience with pumping salt at near freezing point significant care must be used during operation which can increase the operating costs. Therefore, we conclude the savings are marginal to justify using this concept for PCM-TES over a two-tank TES. The report documents the specialty coatings, the composition and morphology of hypereutectic salt mixtures and the results from the experiment conducted with the active heat exchanger along with the lessons learnt during

  13. A new hybrid ocean thermal energy conversion–Offshore solar pond (OTEC–OSP) design: a cost optimization approach

    NARCIS (Netherlands)

    Straatman, P.J.T.; van Sark, W.G.J.H.M.

    2008-01-01

    Solar thermal electricity (STE) generation offers an excellent opportunity to supply electricity with a non-CO2 emitting technology. However, present costs hamper widespread deployment and therefore research and development efforts are concentrated on accelerated cost reductions and efficiency

  14. Kocuria marina BS-15 a biosurfactant producing halophilic bacteria isolated from solar salt works in India

    Science.gov (United States)

    Sarafin, Yesurethinam; Donio, Mariathasan Birdilla Selva; Velmurugan, Subramanian; Michaelbabu, Mariavincent; Citarasu, Thavasimuthu

    2014-01-01

    Biosurfactant screening was made among the eight halophilic bacterial genera isolated from Kovalam solar salt works in Kanyakumari of India. After initial screening, Kocuria sp. (Km), Kurthia sp. (Ku) and Halococcus sp. (Hc) were found to have positive biosurfactant activity. Biosurfactant derived from Kocuria sp. emulsified more than 50% of the crude oil, coconut oil, sunflower oil, olive oil and kerosene when compared to the other strains. Further, Kocuria marina BS-15 derived biosurfactant was purified and characterized by TLC, FTIR and GC–MS analysis. The TLC analysis revealed that, the purified biosurfactants belong to the lipopeptide group. The IR spectrum results revealed that functional groups are R2C 000000000000 000000000000 000000000000 111111111111 000000000000 111111111111 000000000000 000000000000 000000000000 NN, alkenes and N–H. The GC–MS analysis confirmed the compound as Nonanoic acid and Cyclopropane with the retention time of 12.78 and 24.65, respectively. PMID:25473358

  15. Investigation of solar parabolic trough power plants with and without integrated TES (thermal energy storage) and FBS (fuel backup system) using thermic oil and solar salt

    International Nuclear Information System (INIS)

    Boukelia, T.E.; Mecibah, M.S.; Kumar, B.N.; Reddy, K.S.

    2015-01-01

    Thermodynamic, economic and environmental analyses of concentrating solar power plants assist in identifying an effective and viable configuration. In this paper, a 4E (energy-exergy-environmental-economic) comparative study of 8 different configurations of parabolic trough solar thermal power plants with two different working fluids (Therminol VP-1 -oil and molten solar salt), with and without integrated thermal energy storage or/and backup fuel system is presented. The results of the comparative study indicate relevant differences among the 8 configurations. The molten solar salt configuration with integrated thermal energy storage and fossil fuel backup system exhibits the highest overall energy efficiency (18.48%) compared to other configurations. Whereas, the highest overall exergy efficiency (21.77%), capacity factor (38.20%) and annual energy generation (114 GWh) are found for the oil based configuration with integrated thermal energy storage and fossil fuel backup system. The results indicate that the configurations based on molten salt are better in terms of environmental and economical parameters. The configurations with integrated thermal energy storage and fossil fuel backup system are found to be techno-economical, but on the other hand are less environment friendly. A detailed comparison of these plants after optimization must be performed before drawing a final conclusion about the best configuration to be adopted in parabolic trough solar thermal power plant. - Highlights: • 4E comparative study of 8 configurations of PTSTPP with two different fluids. • Comparison of the configurations with and without integrated TES (thermal energy storage) and FBS (fuel backup system). • The overall energy efficiency of the salt plant with TES and FBS is the highest. • The overall exergy efficiency of the oil plant with TES and FBS is the highest. • The salt plants are the best configurations in terms of environ–eco parameters

  16. Theoretical study on thermal stability of molten salt for solar thermal power

    International Nuclear Information System (INIS)

    Wei, Xiaolan; Peng, Qiang; Ding, Jing; Yang, Xiaoxi; Yang, Jianping; Long, Bin

    2013-01-01

    Molten salt (HTS) composed of 53% KNO 3 , 40% NaNO 2 and 7 wt.% NaNO 3 has been used as heat transfer media and thermal storage fluid in the solar thermal power, but thermal decomposition will occur at higher temperature because of the oxidation of nitrite to nitrate in the air. In this paper, the reaction mechanism of NO 2 − oxidation is researched by quantum mechanical method. The results show that two components of the transition state (O 2 NO 2 − ) and intermediate ([NO 4 − ]) are found in the reaction. This reaction is an exothermic reaction and the activation barrier is 94.0 kJ mol −1 . The energy difference of this reaction is very large, so the reaction rate is very slow. -- Highlights: ► The mechanism of the oxidation of nitrite salt in HTS is explained. ► Two components of the transition state (O 2 NO 2 − ) and intermediate ([NO 4 − ]) are found. ► The activation barrier of the nitrite oxidation is determined

  17. Biogeochemical ecology of aquaculture ponds

    International Nuclear Information System (INIS)

    Weisburd, R.S.J.

    1988-01-01

    Two methods to determine rates of organic matter production and consumption were applied in shrimp aquaculture ponds. Several questions were posed: can net rates of organic matter production and consumption be determined accurately through application of dissolved inorganic carbon (DIC) mass balance in a pond with high advective through-put? Are organically loaded aquaculture ponds autotrophic? How do rates of organic production vary temporally? Are there diurnal changes in respiration rates? Four marine ponds in Hawaii have been evaluated for a 53 day period through the use of geochemical mass balances. All fluxes of DIC into and out of the ponds were considered. DIC was calculated from hourly pH measurements and weekly alkalinity measurements. Average uptake of DIC from the pond water, equivalent to net community production, revealed net autotrophy in all cases. Hourly and longer period variations in organic matter production rates were examined. The daily cycle dominated the variation in rates of net community production. Maximal rates of net community production were maintained for four to six hours starting in mid-morning. Respiration rates decreased rapidly during the night in two of the ponds and remained essentially constant in the others. A similar pattern of decreasing respiration at night was seen in freshwater shrimp ponds which were studied with incubations. A new method involving isotope dilution of 14 C-labeled DIC was used to measure respiration rates in light and dark bottles. This method is an inexpensive and convenient procedure which should also be useful in other environments. The incubations demonstrated that plankton respiration rates peak at or soon after solar noon and vary over the course of the day by about a factor of two

  18. Waste Stabilisation Ponds

    OpenAIRE

    Von Sperling, Marcos

    2007-01-01

    "Waste Stabilisation Ponds is the third volume in the series Biological Wastewater Treatment. The major variants of pond systems are fully covered, namely: facultative ponds anaerobic ponds aerated lagoons maturation ponds The book presents in a clear and informative way the main concepts, working principles, expected removal efficiencies, design criteria, design examples, construction aspects, operational guidelines and sludge managment for pond systems. About the series: The series is...

  19. Long-term cover design for low-level radioactive and hazardous waste sites as applied to the Rocky Flats Environmental Technology Site solar evaporation ponds

    International Nuclear Information System (INIS)

    Stenseng, S.E.; Nixon, P.A.

    1996-01-01

    The US Department of Energy (DOE) operated five lined solar evaporation ponds (SEPs) at the Rocky Flats Environmental Technology Site (RFETS) in Jefferson County, Colorado from 1953 until 1986. The SEPs were used primarily to store and evaporate low-level radioactive and hazardous process wastes. Operation of the SEPs has resulted in contamination of the surrounding soils, and may also provide a source of groundwater contamination. The DOE proposes to close the SEPs by consolidating the contaminated material beneath an engineered cover. The primary objective of the closure of such hazardous and radioactive sites is to limit the exposure of the general public to the contaminants for time periods ranging from 100 to 10,000 years. The goal of the SEPs engineered cover is to isolate hazardous and low-level radioactive soils for a minimum of 1,000 years. Since there is currently no existing regulatory design guidance for a 1,000-year engineered cover, the proposed design of the SEPs engineered cover is based on research and testing that has been conducted for many years at various DOE facilities in the US. This paper discusses the main design theories of the proposed engineered cover for the closure of the SEPs, and how the research and test results of these other programs have been used to arrive at the final cover configuration, the material selections, the component layering, layer thicknesses, and the balance and interaction between components to establish an overall effective cover system

  20. Coupled optical and thermal detailed simulations for the accurate evaluation and performance improvement of molten salts solar towers

    Science.gov (United States)

    García-Barberena, Javier; Mutuberria, Amaia; Palacin, Luis G.; Sanz, Javier L.; Pereira, Daniel; Bernardos, Ana; Sanchez, Marcelino; Rocha, Alberto R.

    2017-06-01

    The National Renewable Energy Centre of Spain, CENER, and the Technology & Innovation area of ACS Cobra, as a result of their long term expertise in the CSP field, have developed a high-quality and high level of detail optical and thermal simulation software for the accurate evaluation of Molten Salts Solar Towers. The main purpose of this software is to make a step forward in the state-of-the-art of the Solar Towers simulation programs. Generally, these programs deal with the most critical systems of such plants, i.e. the solar field and the receiver, on an independent basis. Therefore, these programs typically neglect relevant aspects in the operation of the plant as heliostat aiming strategies, solar flux shapes onto the receiver, material physical and operational limitations, transient processes as preheating and secure cloud passing operating modes, and more. The modelling approach implemented in the developed program consists on effectively coupling detailed optical simulations of the heliostat field with also detailed and full-transient thermal simulations of the molten salts tube-based external receiver. The optical model is based on an accurate Monte Carlo ray-tracing method which solves the complete solar field by simulating each of the heliostats at once according to their specific layout in the field. In the thermal side, the tube-based cylindrical external receiver of a Molten Salts Solar Tower is modelled assuming one representative tube per panel, and implementing the specific connection layout of the panels as well as the internal receiver pipes. Each tube is longitudinally discretized and the transient energy and mass balances in the temperature dependent molten salts and steel tube models are solved. For this, a one dimensional radial heat transfer model based is used. The thermal model is completed with a detailed control and operation strategy module, able to represent the appropriate operation of the plant. An integration framework has been

  1. Thermal performance prediction and sensitivity analysis for future deployment of molten salt cavity receiver solar power plants in Algeria

    International Nuclear Information System (INIS)

    Boudaoud, S.; Khellaf, A.; Mohammedi, K.; Behar, O.

    2015-01-01

    Highlights: • Performance of power plant with molten salt cavity receiver is assessed. • A method has been used to optimize the plant solar multiple, capacity factor and LEC. • Comparison of the simulated results to those of PS20 has shown good agreement. • Higher fossil fuel fraction reduces the LEC and increases the capacity factor. • Highland and Sahara regions are suitable for CRS plants deployment. - Abstract: Of all Concentrating Solar Power (CSP) technologies available today, the molten salt solar power plant appears to be the most important option for providing a major share of the clean and renewable electricity needed in the future. In the present paper, a technical and economic analysis for the implementation of a probable molten salt cavity receiver thermal power plant in Algeria has been carried out. In order to do so, we have investigated the effect of solar field size, storage capacity factor, solar radiation intensity, hybridization and power plant capacity on the thermal efficiency and electricity cost of the selected plant. The system advisor model has been used to perform the technical performance and the economic assessment for different locations (coastal, highland and Sahara regions) in Algeria. Taking into account various factors, a method has been applied to optimize the solar multiple and the capacity factor of the plant, to get a trade-off between the incremental investment costs of the heliostat field and the thermal energy storage. The analysis has shown that the use of higher fossil fuel fraction significantly reduces the levelized electricity cost (LEC) and sensibly increases the capacity factor (CF). The present study indicates that hybrid molten salt solar tower power technology is very promising. The CF and the LEC have been found to be respectively of the order of 71% and 0.35 $/kW e . For solar-only power plants, these parameters are respectively about 27% and 0.63 $/kW e . Therefore, hybrid central receiver systems are

  2. The refreezing of melt ponds on Arctic sea ice

    Science.gov (United States)

    Flocco, Daniela; Feltham, Daniel L.; Bailey, Eleanor; Schroeder, David

    2015-02-01

    The presence of melt ponds on the surface of Arctic sea ice significantly reduces its albedo, inducing a positive feedback leading to sea ice thinning. While the role of melt ponds in enhancing the summer melt of sea ice is well known, their impact on suppressing winter freezing of sea ice has, hitherto, received less attention. Melt ponds freeze by forming an ice lid at the upper surface, which insulates them from the atmosphere and traps pond water between the underlying sea ice and the ice lid. The pond water is a store of latent heat, which is released during refreezing. Until a pond freezes completely, there can be minimal ice growth at the base of the underlying sea ice. In this work, we present a model of the refreezing of a melt pond that includes the heat and salt balances in the ice lid, trapped pond, and underlying sea ice. The model uses a two-stream radiation model to account for radiative scattering at phase boundaries. Simulations and related sensitivity studies suggest that trapped pond water may survive for over a month. We focus on the role that pond salinity has on delaying the refreezing process and retarding basal sea ice growth. We estimate that for a typical sea ice pond coverage in autumn, excluding the impact of trapped ponds in models overestimates ice growth by up to 265 million km3, an overestimate of 26%.

  3. Description of Idiomarina insulisalsae sp. nov., isolated from the soil of a sea salt evaporation pond, proposal to transfer the species of the genus Pseudidiomarina to the genus Idiomarina and emended description of the genus Idiomarina.

    Science.gov (United States)

    Taborda, Marco; Antunes, André; Tiago, Igor; Veríssimo, António; Nobre, M Fernanda; da Costa, Milton S

    2009-09-01

    A halophilic, aerobic Gram-negative bacterium, designated strain CVS-6(T), was isolated from a sea salt evaporation pond on the Island of Sal in the Cape Verde Archipelago. Phylogenetic analysis of the 16S rRNA gene sequence revealed a clear affiliation of the organism with members of the family Idiomarinaceae. Sequence similarities between CVS-6(T) and the type strains of the species of the genera Pseudidiomarina and Idiomarina ranged from 93.7% to 96.9%. The major isoprenoid quinone was ubiquinone 8 (Q-8). The major cellular fatty acids were 15:0 iso (21.8%), 17:0 iso (12.5%), 17:1 iso omega9c (10.7%), and 16:1 omega7c (10.6%). The DNA G+C content was 51.6 mol%. The species represented by strain CVS-6(T) could be distinguished from the species of the genera Pseudidiomarina and Idiomarina; however, it was not possible to distinguish both genera from each other using the phenotypic or chemotaxonomic characteristics examined. Consequently, we propose that the species classified in the genus Pseudidiomarina should be transferred to the genus Idiomarina. We also propose that, on the basis of physiological and biochemical characteristics, strain CVS-6(T) (=LMG 23123=CIP 108836) represents a new species which we name Idiomarina insulisalsae.

  4. Novel concepts in electrochemical solar cells. Second quarterly progress report, August 15, 1979-October 15, 1979. [Molten salt electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    DuBow, J.; Job, R.; Krishnan, R.; Gale, B.

    1979-01-01

    It is considered that the short term stability of n-GaAs PEC's in a ferrocene-based, ambient temperature molten salt electrolyte is reasonably good. However, longer term evaluation is required to determine the extent and significance of corrosion, stability, etc. Extremely few fundamental studies have been made of the semiconductor/molten salt interphase and experiments in this area would be most useful. Indeed, even the design parameters for PECs of any kind have not been quantitatively delineated and present consideration will be given to models for PEC solar cells and limitations caused by ion transport in the electrolyte. The MoSe/sub 2/ and MoS/sub 2/ electrodes appear to have substrate reproducibility and transport limitations that make them unsuitable candidates for efficient PEC's at this time. Similarly, the lack of availability of high quality CuInSe/sub 2/ and CuInS/sub 2/ substrates limits the quantitative experimental evaluation of their utility for PEC applications. We are presently focusing attention on CdSe/CdTe mixtures and CdS as electrodes as well as Si and GaAs in molten salt and polyelectrolyte solutions. The system for solar cell evaluation and network analysis of substrates and cells was mode operational. Preliminary work on economic and theoretical modelling was begun. Progress is reported. (WHK)

  5. Lake or Pond WBID

    Data.gov (United States)

    Vermont Center for Geographic Information — The VT DEC (Vermont Department of Environmental Conservation) manages an inventory of lake and pond information. The "Lakes and Ponds Inventory" stores the Water...

  6. Treatment of pond sludge at the Rocky Flats Plant

    International Nuclear Information System (INIS)

    Wienand, J.; Tyler, R.; Baldwin, C.

    1992-01-01

    The treatment of low-level radioactive/hazardous materials sludges from five inactive solar evaporation settling ponds at the Rocky Flats Plant is discussed. The paper presents information on the following topics: history of the ponds; previous pond cleanout activities; current approach to the problem with respect to water management, sludge management, regulatory actions, and disposal; and future processing technology needs in the areas of polymer solidification, microwave solidification, joule-heated glass melters, and advanced technology incineration

  7. Technical manual for calculating cooling pond performance

    International Nuclear Information System (INIS)

    Krstulovich, S.F.

    1988-01-01

    This manual is produced in response to a growing number of requests for a technical aid to explain methods for simulating cooling pond performance. As such, it is a compilation of reports, charts and graphs developed through the years for use in analyzing situations. Section II contains a report summarizing the factors affecting cooling pond performance and lists statistical parameters used in developing performance simulations. Section III contains the graphs of simulated cooling pond performance on an hourly basis for various combinations of criteria (wind, solar, depth, air temperature and humidity) developed from the report in Section II. Section IV contains correspondence describing how to develop further data from the graphs in Section III, as well as mathematical models for the system of performance calculation. Section V contains the formulas used to simulate cooling pond performances in a cascade arrangement, such as the Fermilab Main Ring ponds. Section VI contains the calculations currently in use to evaluate the Main Ring pond performance based on current flows and Watts loadings. Section VII contains the overall site drawing of the Main Ring cooling ponds with thermal analysis and physical data

  8. Halomonas sp. BS4, A biosurfactant producing halophilic bacterium isolated from solar salt works in India and their biomedical importance

    OpenAIRE

    Donio, Mariathason Birdilla Selva; Ronica, Fernando Arul; Viji, Vijayaragavan Thanga; Velmurugan, Subramanian; Jenifer, John Selesteen Charles Adlin; Michaelbabu, Mariavincent; Dhar, Prasenjit; Citarasu, Thavasimuthu

    2013-01-01

    Halophilic bacteria were isolated from Thamaraikulam solar salt works in India. After routine biosurfactant screening by various methods, the biosurfactant producing bacteria, Halomonas sp BS4 was confirmed by 16?S rRNA sequencing. The growth optimization of Halomonas sp BS4 revealed their optimum growth at 8% NaCl and 6-8?pH in the growth medium. Further the partially purified biosurfactants were characterized by TLC, FTIR and GC-MS analysis. GC-MS results revealed that, the partial purified...

  9. Stabilization of molten salt materials using metal chlorides for solar thermal storage.

    Science.gov (United States)

    Dunlop, T O; Jarvis, D J; Voice, W E; Sullivan, J H

    2018-05-29

    The effect of a variety of metal-chlorides additions on the melting behavior and thermal stability of commercially available salts was investigated. Ternary salts comprised of KNO 3, NaNO 2, and NaNO 3 were produced with additions of a variety of chlorides (KCl, LiCl, CaCl 2 , ZnCl 2 , NaCl and MgCl 2 ). Thermogravimetric analysis and weight loss experiments showed that the quaternary salt containing a 5 wt% addition of LiCl and KCl led to an increase in short term thermal stability compared to the ternary control salts. These additions allowed the salts to remain stable up to a temperature of 630 °C. Long term weight loss experiments showed an upper stability increase of 50 °C. A 5 wt% LiCl addition resulted in a weight loss of only 25% after 30 hours in comparison to a 61% loss for control ternary salts. Calorimetry showed that LiCl additions allow partial melting at 80 °C, in comparison to the 142 °C of ternary salts. This drop in melting point, combined with increased stability, provided a molten working range increase of almost 100 °C in total, in comparison to the control ternary salts. XRD analysis showed the oxidation effect of decomposing salts and the additional phase created with LiCl additions to allow melting point changes to occur.

  10. The color of melt ponds on Arctic sea ice

    Science.gov (United States)

    Lu, Peng; Leppäranta, Matti; Cheng, Bin; Li, Zhijun; Istomina, Larysa; Heygster, Georg

    2018-04-01

    Pond color, which creates the visual appearance of melt ponds on Arctic sea ice in summer, is quantitatively investigated using a two-stream radiative transfer model for ponded sea ice. The upwelling irradiance from the pond surface is determined and then its spectrum is transformed into RGB (red, green, blue) color space using a colorimetric method. The dependence of pond color on various factors such as water and ice properties and incident solar radiation is investigated. The results reveal that increasing underlying ice thickness Hi enhances both the green and blue intensities of pond color, whereas the red intensity is mostly sensitive to Hi for thin ice (Hi 1.5 m), similar to the behavior of melt-pond albedo. The distribution of the incident solar spectrum F0 with wavelength affects the pond color rather than its intensity. The pond color changes from dark blue to brighter blue with increasing scattering in ice, and the influence of absorption in ice on pond color is limited. The pond color reproduced by the model agrees with field observations for Arctic sea ice in summer, which supports the validity of this study. More importantly, the pond color has been confirmed to contain information about meltwater and underlying ice, and therefore it can be used as an index to retrieve Hi and Hp. Retrievals of Hi for thin ice (Hi measurements than retrievals for thick ice, but those of Hp are not good. The analysis of pond color is a new potential method to obtain thin ice thickness in summer, although more validation data and improvements to the radiative transfer model will be needed in future.

  11. Renewable and high efficient syngas production from carbon dioxide and water through solar energy assisted electrolysis in eutectic molten salts

    Science.gov (United States)

    Wu, Hongjun; Liu, Yue; Ji, Deqiang; Li, Zhida; Yi, Guanlin; Yuan, Dandan; Wang, Baohui; Zhang, Zhonghai; Wang, Peng

    2017-09-01

    Over-reliance on non-renewable fossil fuel leads to steadily increasing concentration of atmospheric CO2, which has been implicated as a critical factor contributing to global warming. The efficient conversion of CO2 into useful product is highly sought after both in academic and industry. Herein, a novel conversion strategy is proposed to one-step transform CO2/H2O into syngas (CO/H2) in molten salt with electrolysis method. All the energy consumption in this system are contributed from sustainable energy sources: concentrated solar light heats molten salt and solar cell supplies electricity for electrolysis. The eutectic Li0.85Na0.61K0.54CO3/nLiOH molten electrolyte is rationally designed with low melting point (<450 °C). The synthesized syngas contains very desirable content of H2 and CO, with tuneable molar ratios (H2/CO) from 0.6 to 7.8, and with an efficient faradaic efficiency of ∼94.5%. The synthesis of syngas from CO2 with renewable energy at a such low electrolytic temperature not only alleviates heat loss, mitigates system corrosion, and heightens operational safety, but also decreases the generation of methane, thus increases the yield of syngas, which is a remarkable technological breakthrough and this work thus represents a stride in sustainable conversion of CO2 to value-added product.

  12. Renewable and high efficient syngas production from carbon dioxide and water through solar energy assisted electrolysis in eutectic molten salts

    KAUST Repository

    Wu, Hongjun

    2017-07-13

    Over-reliance on non-renewable fossil fuel leads to steadily increasing concentration of atmospheric CO2, which has been implicated as a critical factor contributing to global warming. The efficient conversion of CO2 into useful product is highly sought after both in academic and industry. Herein, a novel conversion strategy is proposed to one-step transform CO2/H2O into syngas (CO/H2) in molten salt with electrolysis method. All the energy consumption in this system are contributed from sustainable energy sources: concentrated solar light heats molten salt and solar cell supplies electricity for electrolysis. The eutectic Li0.85Na0.61K0.54CO3/nLiOH molten electrolyte is rationally designed with low melting point (<450 °C). The synthesized syngas contains very desirable content of H2 and CO, with tuneable molar ratios (H2/CO) from 0.6 to 7.8, and with an efficient faradaic efficiency of ∼94.5%. The synthesis of syngas from CO2 with renewable energy at a such low electrolytic temperature not only alleviates heat loss, mitigates system corrosion, and heightens operational safety, but also decreases the generation of methane, thus increases the yield of syngas, which is a remarkable technological breakthrough and this work thus represents a stride in sustainable conversion of CO2 to value-added product.

  13. Improvement of N-phthaloylchitosan based gel polymer electrolyte in dye-sensitized solar cells using a binary salt system.

    Science.gov (United States)

    Yusuf, S N F; Azzahari, A D; Selvanathan, V; Yahya, R; Careem, M A; Arof, A K

    2017-02-10

    A binary salt system utilizing lithium iodide (LiI) as the auxiliary component has been introduced to the N-phthaloylchitosan (PhCh) based gel polymer electrolyte consisting of ethylene carbonate (EC), dimethylformamide (DMF), tetrapropylammonium iodide (TPAI), and iodine (I 2 ) in order to improve the performance of dye-sensitized solar cell (DSSC) with efficiency of 6.36%, photocurrent density, J SC of 17.29mAcm -2 , open circuit voltage, V OC of 0.59V and fill factor, FF of 0.62. This efficiency value is an improvement from the 5.00% performance obtained by the DSSC consisting of only TPAI single salt system. The presence of the LiI in addition to the TPAI improves the charge injection rates and increases the iodide contribution to the total conductivity and both factors contribute to the increase in efficiency of the DSSC. The interaction behavior between polymer-plasticizer-salt was thoroughly investigated using EIS, FTIR spectroscopy and XRD. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. The influence of mixing water on the thermophysical properties of nanofluids based on solar salt and silica nanoparticles

    Science.gov (United States)

    Muñoz-Sánchez, B.; Nieto-Maestre, J.; Iparraguirre-Torres, I.; Sánchez-García, J. A.; Julia, J. E.; García-Romero, A.

    2016-05-01

    The use of nanofluids (NFs) based on Solar Salt (SS) and nanoparticles (NPs), either as Thermal Energy Storage (TES) material or as Heat Transfer Fluid (HTF), is attracting great interest in recent years. Many authors [1,3] have reported important improvements on the thermophysical properties (specific heat capacity cp,thermal conductivity k) of NFs based on SS and ceramic NPs. These improvements would lead to important savings and better performance of TES facilities on new Concentrated Solar Power (CSP) plants due to lower quantities of material required and smaller storage tanks. To achieve these advantageous features in the final NFs, it is essential to avoid NP agglomeration during their preparation. Different synthesis procedures have been reported: mixing of solid NPs within a SS solution by means of ultrasounds [1-3], direct mixing of solid NPs and molten salt [4]. In this work, NFs based on SS and 1% by wt. of silica NPs were synthetized from a SS-water solution and a commercial water-silica NF called Ludox HS 30% (Sigma-Aldrich). The influence of the mixing water volume (MW) on the cp of NFs was evaluated. With this aim, the cp of these samples was measured by Differential Scanning Calorimetry (DSC) both in the solid and the liquid state. In addition, the distribution of sizes was measured during the whole preparation process by Dynamic Light Scattering (DLS). Further information about sizes and uniformity of the final NFs was obtained from Scanning Electron Microscopy (SEM) images. X-ray Diffraction (XRD) patterns of the SS and final NF were performed.

  15. Mineral resource of the month: salt

    Science.gov (United States)

    Kostick, Dennis S.

    2010-01-01

    The article presents information on various types of salt. Rock salt is either found from underground halite deposits or near the surface. Other types of salt include solar salt, salt brine, and vacuum pan salt. The different uses of salt are also given including its use as a flavor enhancer, as a road deicing agent, and to manufacture sodium hydroxide.

  16. A solar-thermal energy harvesting scheme: enhanced heat capacity of molten HITEC salt mixed with Sn/SiO(x) core-shell nanoparticles.

    Science.gov (United States)

    Lai, Chih-Chung; Chang, Wen-Chih; Hu, Wen-Liang; Wang, Zhiming M; Lu, Ming-Chang; Chueh, Yu-Lun

    2014-05-07

    We demonstrated enhanced solar-thermal storage by releasing the latent heat of Sn/SiO(x) core-shell nanoparticles (NPs) embedded in a eutectic salt. The microstructures and chemical compositions of Sn/SiO(x) core-shell NPs were characterized. In situ heating XRD provides dynamic crystalline information about the Sn/SiO(x) core-shell NPs during cyclic heating processes. The latent heat of ∼29 J g(-1) for Sn/SiO(x) core-shell NPs was measured, and 30% enhanced heat capacity was achieved from 1.57 to 2.03 J g(-1) K(-1) for the HITEC solar salt without and with, respectively, a mixture of 5% Sn/SiO(x) core-shell NPs. In addition, an endurance cycle test was performed to prove a stable operation in practical applications. The approach provides a method to enhance energy storage in solar-thermal power plants.

  17. Par Pond water balance

    International Nuclear Information System (INIS)

    Hiergesell, R.A.; Dixon, K.L.

    1996-06-01

    A water budget for the Par Pond hydrologic system was established in order to estimate the rate of groundwater influx to Par Pond. This estimate will be used in modeling exercises to predict Par Pond reservoir elevation and spillway discharge in the scenario where Savannah River water is no longer pumped and discharged into Par Pond. The principal of conservation of mass was used to develop the water budget, where water inflow was set equal to water outflow. Components of the water budget were identified, and the flux associated with each was determined. The water budget was considered balanced when inflow and outflow summed to zero. The results of this study suggest that Par Pond gains water from the groundwater system in the upper reaches of the reservoir, but looses water to the groundwater system near the dam. The rate of flux of groundwater from the water table aquifer into Par Pond was determined to be 13 cfs. The rate of flux from Par Pond to the water table aquifer near the dam was determined to be 7 cfs

  18. Estimation of Melt Ponds over Arctic Sea Ice using MODIS Surface Reflectance Data

    Science.gov (United States)

    Ding, Y.; Cheng, X.; Liu, J.

    2017-12-01

    Melt ponds over Arctic sea ice is one of the main factors affecting variability of surface albedo, increasing absorption of solar radiation and further melting of snow and ice. In recent years, a large number of melt ponds have been observed during the melt season in Arctic. Moreover, some studies have suggested that late spring to mid summer melt ponds information promises to improve the prediction skill of seasonal Arctic sea ice minimum. In the study, we extract the melt pond fraction over Arctic sea ice since 2000 using three bands MODIS weekly surface reflectance data by considering the difference of spectral reflectance in ponds, ice and open water. The preliminary comparison shows our derived Arctic-wide melt ponds are in good agreement with that derived by the University of Hamburg, especially at the pond distribution. We analyze seasonal evolution, interannual variability and trend of the melt ponds, as well as the changes of onset and re-freezing. The melt pond fraction shows an asymmetrical growth and decay pattern. The observed melt ponds fraction is almost within 25% in early May and increases rapidly in June and July with a high fraction of more than 40% in the east of Greenland and Beaufort Sea. A significant increasing trend in the melt pond fraction is observed for the period of 2000-2017. The relationship between melt pond fraction and sea ice extent will be also discussed. Key Words: melt ponds, sea ice, Arctic

  19. Solar program of the Research Institute/UPM

    Energy Technology Data Exchange (ETDEWEB)

    Nimmo, B.; Dabbagh, A.; Said, S.

    1980-07-01

    Projects are described and results presented for three of the solar related activities presently underway: Solar Radiation Monitoring, Effects of Dust Accumulation on Collector Performance, and Salt Gradient Solar Pond Analytical and Experimental Studies. Measurements of total horizontal and direct radiation have been made continuously since May, 1979 and the data are presented in a user oriented format on an hourly basis. These results have been extended by calculation to allow presentation on an hourly basis of diffuse radiation and total radiation on a surface tilted to the local latitude angle. The system is presently being expanded to allow measurement of several additional radiation parameters of interest as well as six meteorological parameters. Some results are presented to show the effects of atmospheric dust on radiation attenuation, as well as the clearness index, anti K/sub T/. Results are also presented for a related study, the impact of surface dust accumulation on the performance of photovoltaic and thermal collectors. Continuous monitoring of the peak watt output of a small photovoltaic panel during a period which included severe dust storms showed a decrease in performance of sixty percent (60%) relative to the clean panel output. Settling of dust on the surface of a solar pond does not, on the other hand, appear to be a problem. The salt gradient solar pond work is proceeding on two fronts: analytical and experimental. Preliminary results are presented for a varying property transient one dimensional computer model currently being used in design studies. Preliminary experimental results are also presented for temperature profiles measured in our small prototype pond.

  20. Integration of membrane distillation into traditional salt farming method: Process development and modelling

    Science.gov (United States)

    Hizam, S.; Bilad, M. R.; Putra, Z. A.

    2017-10-01

    Farmers still practice the traditional salt farming in many regions, particularly in Indonesia. This archaic method not only produces low yield and poor salt quality, it is also laborious. Furthermore, the farming locations typically have poor access to fresh water and are far away from electricity grid, which restrict upgrade to a more advanced technology for salt production. This paper proposes a new concept of salt harvesting method that improves the salt yield and at the same time facilitates recovery of fresh water from seawater. The new concept integrates solar powered membrane distillation (MD) and photovoltaic cells to drive the pumping. We performed basic solar still experiments to quantify the heat flux received by a pond. The data were used as insight for designing the proposed concept, particularly on operational strategy and the most effective way to integrate MD. After the conceptual design had been developed, we formulated mass and energy balance to estimate the performance of the proposed concept. Based on our data and design, it is expected that the system would improve the yield and quality of the salt production, maximizing fresh water harvesting, and eventually provides economical gain for salt farmers hence improving their quality of life. The key performance can only be measured via experiment using gain output ratio as performance indicator, which will be done in a future study.

  1. Emissions from Produced Water Treatment Ponds, Uintah Basin, Utah, USA

    Science.gov (United States)

    Mansfield, M. L.; Lyman, S. N.; Tran, H.; O'Neil, T.; Anderson, R.

    2015-12-01

    An aqueous phase, known as "produced water," usually accompanies the hydrocarbon fluid phases that are extracted from Earth's crust during oil and natural gas extraction. Produced water contains dissolved and suspended organics and other contaminants and hence cannot be discharged directly into the hydrosphere. One common disposal method is to discharge produced water into open-pit evaporation ponds. Spent hydraulic fracturing fluids are also often discharged into the same ponds. It is obvious to anyone with a healthy olfactory system that such ponds emit volatile organics to the atmosphere, but very little work has been done to characterize such emissions. Because oil, gas, and water phases are often in contact in geologic formations, we can expect that more highly soluble compounds (e.g., salts, alcohols, carbonyls, carboxyls, BTEX, etc.) partition preferentially into produced water. However, as the water in the ponds age, many physical, chemical, and biological processes alter the composition of the water, and therefore the composition and strength of volatile organic emissions. For example, some ponds are aerated to hasten evaporation, which also promotes oxidation of organics dissolved in the water. Some ponds are treated with microbes to promote bio-oxidation. In other words, emissions from ponds are expected to be a complex function of the composition of the water as it first enters the pond, and also of the age of the water and of its treatment history. We have conducted many measurements of emissions from produced water ponds in the Uintah Basin of eastern Utah, both by flux chamber and by evacuated canister sampling with inverse modeling. These measurements include fluxes of CO2, CH4, methanol, and many other volatile organic gases. We have also measured chemical compositions and microbial content of water in the ponds. Results of these measurements will be reported.

  2. Halomonas sp. BS4, A biosurfactant producing halophilic bacterium isolated from solar salt works in India and their biomedical importance.

    Science.gov (United States)

    Donio, Mariathason Birdilla Selva; Ronica, Fernando Arul; Viji, Vijayaragavan Thanga; Velmurugan, Subramanian; Jenifer, John Selesteen Charles Adlin; Michaelbabu, Mariavincent; Dhar, Prasenjit; Citarasu, Thavasimuthu

    2013-12-01

    Halophilic bacteria were isolated from Thamaraikulam solar salt works in India. After routine biosurfactant screening by various methods, the biosurfactant producing bacteria, Halomonas sp BS4 was confirmed by 16 S rRNA sequencing. The growth optimization of Halomonas sp BS4 revealed their optimum growth at 8% NaCl and 6-8 pH in the growth medium. Further the partially purified biosurfactants were characterized by TLC, FTIR and GC-MS analysis. GC-MS results revealed that, the partial purified biosurfactants contain 1, 2-Ethanediamine N, N, N', N'-tetra, 8-Methyl-6-nonenamide, (Z)-9-octadecenamide and a fatty acid derivative. Pharmacological screening of antibacterial, antifungal, antiviral and anticancer assays revealed that, the biosurfactant extracted from Halomonas sp BS4 effectively controlled the human pathogenic bacteria and fungi an aquaculturally important virus, WSSV. The biosurfactant also suppressed the proliferation of mammary epithelial carcinoma cell by 46.77% at 2.5 μg concentration. Based on these findings, the present study concluded that, there is a possibility to develop eco-friendly antimicrobial and anticancer drugs from the extremophilic origin.

  3. Microbial reduction of [Co(III)-EDTA]⁻ by Bacillus licheniformis SPB-2 strain isolated from a solar salt pan.

    Science.gov (United States)

    Paraneeiswaran, Arunachalam; Shukla, Sudhir K; Prashanth, K; Rao, T Subba

    2015-01-01

    Naturally stressed habitats are known to be repositories for novel microorganisms with potential bioremediation applications. In this study, we isolated a [Co(III)-EDTA](-) reducing bacterium Bacillus licheniformis SPB-2 from a solar salt pan that is exposed to constant cycles of hydration and desiccation in nature. [Co(III)-EDTA](-) generated during nuclear waste management process is difficult to remove from the waste due to its high stability and solubility. It is reduced form i.e. [Co(II)-EDTA](2-) is less stable though it is toxic. This study showed that B. licheniformis SPB-2 reduced 1mM [Co(III)-EDTA](-) in 14 days when grown in a batch mode. However, subsequent cycles showed an increase in the reduction activity, which was observed up to four cycles. Interestingly, the present study also showed that [Co(III)-EDTA](-) acted as an inducer for B. licheniformis SPB-2 spore germination. Vegetative cells germinated from the spores were found to be involved in [Co(III)-EDTA](-) reduction. More detailed investigations showed that after [Co(III)-EDTA](-) reduction, i.e. [Co(II)-EDTA](2-) complex was removed by B. licheniformis SPB-2 from the bulk liquid by adsorption phenomenon. The bacterium showed a D10 value (radiation dose required to kill 90% cells) of ∼250 Gray (Gy), which signifies the potential use of B. licheniformis SPB-2 for bioremediation of moderately active nuclear waste. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Identification of salt-alloy combinations for thermal energy storage applications in advanced solar dynamic power systems

    Science.gov (United States)

    Whittenberger, J. D.; Misra, A. K.

    1987-01-01

    Thermodynamic calculations based on the available data for flouride salt systems reveal that a number of congruently melting compositions and eutectics exist which have the potential to meet the lightweight, high energy storage requirements imposed for advanced solar dynamic systems operating between about 1000 and 1400 K. Compatibility studies to determine suitable containment alloys to be used with NaF-22CaF2-13MgF2, NaF-32CaF2, and NaF-23MgF2 have been conducted at the eutectic temperature + 25 K for each system. For these three NaF-based eutectics, none of the common, commercially available high temperature alloys appear to offer adequate corrosion resistance for a long lifetime; however mild steel, pure nickel and Nb-1Zr could prove useful. These latter materials suggest the possibility that a strong, corrosion resistant, nonrefractory, elevated temperature alloy based on the Ni-Ni3Nb system could be developed.

  5. Cooling pond fog studies

    International Nuclear Information System (INIS)

    Hicks, B.B.

    1978-01-01

    The Fog Excess Water Index (FEWI) method of fog prediction has been verified by the use of data obtained at the Dresden cooling pond during 1976 and 1977 and by a reanalysis of observations made in conjunction with a study of cooling pond simulators during 1974. For applications in which the method is applied to measurements or estimates of bulk water temperature, a critical value of about 0.7 mb appears to be most appropriate. The present analyses confirm the earlier finding that wind speed plays little part in determining the susceptibility for fog generation

  6. Trophic structure and avian communities across a salinity gradient in evaporation ponds of the San Francisco Bay estuary

    Science.gov (United States)

    Takekawa, John Y.; Miles, A.K.; Schoellhamer, D.H.; Athearn, N.D.; Saiki, M.K.; Duffy, W.D.; Kleinschmidt, S.; Shellenbarger, G.G.; Jannusch, C.A.

    2006-01-01

    Commercial salt evaporation ponds comprise a large proportion of baylands adjacent to the San Francisco Bay, a highly urbanized estuary. In the past two centuries, more than 79% of the historic tidal wetlands in this estuary have been lost. Resource management agencies have acquired more than 10 000 ha of commercial salt ponds with plans to undertake one of the largest wetland restoration projects in North America. However, these plans have created debate about the ecological importance of salt ponds for migratory bird communities in western North America. Salt ponds are unique mesohaline (5–18 g l−1) to hyperhaline (> 40 g l−1) wetlands, but little is known of their ecological structure or value. Thus, we studied decommissioned salt ponds in the North Bay of the San Francisco Bay estuary from January 1999 through November 2001. We measured water quality parameters (salinity, DO, pH, temperature), nutrient concentrations, primary productivity, zooplankton, macroinvertebrates, fish, and birds across a range of salinities from 24 to 264 g l−1. Our studies documented how unique limnological characteristics of salt ponds were related to nutrient levels, primary productivity rates, invertebrate biomass and taxa richness, prey fish, and avian predator numbers. Salt ponds were shown to have unique trophic and physical attributes that supported large numbers of migratory birds. Therefore, managers should carefully weigh the benefits of increasing habitat for native tidal marsh species with the costs of losing these unique hypersaline systems.

  7. Renewable energy for the aeration of wastewater ponds.

    Science.gov (United States)

    Hobus, I; Hegemann, W

    2003-01-01

    The application of a decentralised renewable energy supply for the aeration of wastewater ponds, and the influence of an unsteady oxygen supply on the specific conversion rate and biocoenose was investigated. With the discontinuous aeration the specific conversion rate is increased as compared to facultative ponds. The estimation of the microorganisms consortia was done with in situ hybridisation techniques. A significant shift in the bacteria population with the chosen specific probes for anaerobic, sulphate reducing and nitrifying bacteria could not be detected. Wastewater ponds have sufficient buffer volume to compensate for the fluctuating energy supply. But the efficiency of the energy supply of a photovoltaic plant decreases in shallow lakes (d photovoltaic and wind power plant, energy management, aeration system and wastewater pond, a simulation model was developed and tested. The application of renewable energy for the aeration of wastewater ponds is a useful alternative for the redevelopment of overloaded ponds as well as the construction of new wastewater ponds, especially in areas with an inadequate central electricity grid and a high availability of wind and solar energy.

  8. Effect of Al_2O_3 nanoparticle dispersion on the specific heat capacity of a eutectic binary nitrate salt for solar power applications

    International Nuclear Information System (INIS)

    Hu, Yanwei; He, Yurong; Zhang, Zhenduo; Wen, Dongsheng

    2017-01-01

    Highlights: • Stable binary nitrate eutectic salt based Al_2O_3 nanofluids were prepared. • A maximum enhancement of 8.3% on c_p was obtained at 2.0 wt.% nanoparticles. • MD simulation results show good agreement with experimental data. • The change in Coulombic energy contributed to most of the large change in c_p. - Abstract: Molten salts can be used as heat transfer fluids or thermal storage materials in a concentrated solar power plant. Improving the thermal properties can influence the utilization efficiency of solar energy. In this study, the effect of doping eutectic binary salt solvent with Al_2O_3 nanoparticles on its specific heat capacity (c_p) was investigated. The effects of the mass fraction of nanoparticles on the c_p of the composite nanofluid were analyzed, using both differential scanning calorimetry measurements and molecular dynamics simulations. The specific heat capacity of the nanocomposites was enhanced by increasing the nanoparticle concentration. The maximum enhancement was found to be 8.3%, at a nanoparticle concentration of 2.0%. A scanning electron microscope was used to analyze the material morphology. It was observed that special nanostructures were formed and the specific heat capacity of the nanocomposites was enhanced by increasing the quantity of nanostructures. Simulation results of c_p agreed well with the experimental data, and the potential energy and interaction energy in the system were analyzed. The change in Coulombic energy contributed to most of the large change in c_p, which explains the discrepancy in values between conventional nanofluids and molten salt-based nanofluids.

  9. Effect of iron salt counter ion in dose-response curves for inactivation of Fusarium solani in water through solar driven Fenton-like processes

    Science.gov (United States)

    Aurioles-López, Verónica; Polo-López, M. Inmaculada; Fernández-Ibáñez, Pilar; López-Malo, Aurelio; Bandala, Erick R.

    2016-02-01

    The inactivation of Fusarium solani in water was assessed by solar driven Fenton-like processes using three different iron salts: ferric acetylacetonate (Fe(acac)3), ferric chloride (FeCl3) and ferrous sulfate (FeSO4). The experimental conditions tested were [Fe] ≈ 5 mg L-1, [H2O2] ≈ 10 mg L-1 and [Fe] ≈ 10 mg L-1; [H2O2] ≈ 20 mg L-1 mild and high, respectively, and pH 3.0 and 5.0, under solar radiation. The highest inactivation rates were observed at high reaction conditions for the three iron salts tested at pH 5.0 with less than 3.0 kJ L-1 of accumulate energy (QUV) to achieve over 99.9% of F. solani inactivation. Fe(acac)3 was the best iron salt to accomplishing F. solani inactivation. The modified Fermi equation was used to fix the experimental inactivation, data showed it was helpful for modeling the process, adequately describing dose-response curves. Inactivation process using FeSO4 at pH 3.0 was modeled fairly with r2 = 0.98 and 0.99 (mild and high concentration, respectively). Fe(acac)3, FeCl3 and FeSO4 at high concentration (i.e. [Fe] ≈ 10 mg L-1; [H2O2] ≈ 20 mg L-1) and pH 5.0 showed the highest fitting values (r2 = 0.99). Iron salt type showed a remarkable influence on the Fenton-like inactivation process.

  10. Solar India - 82: national solar energy convention

    Energy Technology Data Exchange (ETDEWEB)

    1982-01-01

    This document is the proceedings of the Solar India - 82 conference, which was held 17-19 December 1982. The papers are organized into functional groupings which include: (1) solar radiation, (2) flat plate solar collectors and solar water heaters, (3) solar concentrators, (4) solar air heaters and dryers, (5) solar ponds and energy storage, (6) solar cookers, (7) solar stills, (8) selective coatings, (9) photovoltaics, (10) space heating and cooling, (11) bio-energy, and (12) miscellaneous papers. The vast majority of the papers describe work carried out in India, the vast majority of the papers also contain relatively readable abstracts.

  11. Holocene closure of Lib Pond, Marshall Islands.

    Directory of Open Access Journals (Sweden)

    Conor L Myhrvold

    Full Text Available Well-preserved sediment from closed water bodies of atolls such as Lib Pond are rare opportunities to reconstruct the past regional climate, which pieced together across a latitude and longitude range identify the range of movement patterns of wider scale climate phenomena such as the Intertropical Convergence Zone (ITCZ and El Niño Southern Oscillation (ENSO. We conducted the first physico-chemical survey of Lib Pond, a shallow, closed-water saline lake located on remote and difficult to access Lib Island in the Marshall Islands at 8° 18' 48.99″ N, 167 22' 51.90″ E in the Pacific Ocean, in July 2009. We performed a bathymetric survey, recorded salinity, dissolved oxygen, pH, and temperature profiles, monitored the tidal variability, and conducted a vegetation survey surrounding the lake. From bathymetric data we calculated the lake volume, which we used to estimate the lake's salt budget, and ultimately the residence time of water in the lake basin. We took a series of sediment cores from the lake, cores which indicate Lib Island's changing environment and climate. Radiocarbon measurements determined sediment age, and reveal significant mixing over the last 2 ka of deposition. We conclude that prior to 3 ka, Lib Island was an atoll with a central lagoon connected to the open ocean, which was then closed off from the open ocean to form the brackish system that exists today. We predict that the sediment accumulation in Lib Pond evident today will continue. As seawater is inhibited from exchanging with fresh water, Lib Pond will become a shallower lake with increasingly fresh water.

  12. Holocene closure of Lib Pond, Marshall Islands.

    Science.gov (United States)

    Myhrvold, Conor L; Janny, Fran; Nelson, Daniel; Ladd, S Nemiah; Atwood, Alyssa; Sachs, Julian P

    2014-01-01

    Well-preserved sediment from closed water bodies of atolls such as Lib Pond are rare opportunities to reconstruct the past regional climate, which pieced together across a latitude and longitude range identify the range of movement patterns of wider scale climate phenomena such as the Intertropical Convergence Zone (ITCZ) and El Niño Southern Oscillation (ENSO). We conducted the first physico-chemical survey of Lib Pond, a shallow, closed-water saline lake located on remote and difficult to access Lib Island in the Marshall Islands at 8° 18' 48.99″ N, 167 22' 51.90″ E in the Pacific Ocean, in July 2009. We performed a bathymetric survey, recorded salinity, dissolved oxygen, pH, and temperature profiles, monitored the tidal variability, and conducted a vegetation survey surrounding the lake. From bathymetric data we calculated the lake volume, which we used to estimate the lake's salt budget, and ultimately the residence time of water in the lake basin. We took a series of sediment cores from the lake, cores which indicate Lib Island's changing environment and climate. Radiocarbon measurements determined sediment age, and reveal significant mixing over the last 2 ka of deposition. We conclude that prior to 3 ka, Lib Island was an atoll with a central lagoon connected to the open ocean, which was then closed off from the open ocean to form the brackish system that exists today. We predict that the sediment accumulation in Lib Pond evident today will continue. As seawater is inhibited from exchanging with fresh water, Lib Pond will become a shallower lake with increasingly fresh water.

  13. Results of molten salt panel and component experiments for solar central receivers: Cold fill, freeze/thaw, thermal cycling and shock, and instrumentation tests

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco, J.E.; Ralph, M.E.; Chavez, J.M.; Dunkin, S.R.; Rush, E.E.; Ghanbari, C.M.; Matthews, M.W.

    1995-01-01

    Experiments have been conducted with a molten salt loop at Sandia National Laboratories in Albuquerque, NM to resolve issues associated with the operation of the 10MW{sub e} Solar Two Central Receiver Power Plant located near Barstow, CA. The salt loop contained two receiver panels, components such as flanges and a check valve, vortex shedding and ultrasonic flow meters, and an impedance pressure transducer. Tests were conducted on procedures for filling and thawing a panel, and assessing components and instrumentation in a molten salt environment. Four categories of experiments were conducted: (1) cold filling procedures, (2) freeze/thaw procedures, (3) component tests, and (4) instrumentation tests. Cold-panel and -piping fill experiments are described, in which the panels and piping were preheated to temperatures below the salt freezing point prior to initiating flow, to determine the feasibility of cold filling the receiver and piping. The transient thermal response was measured, and heat transfer coefficients and transient stresses were calculated from the data. Freeze/thaw experiments were conducted with the panels, in which the salt was intentionally allowed to freeze in the receiver tubes, then thawed with heliostat beams. Slow thermal cycling tests were conducted to measure both how well various designs of flanges (e.g., tapered flanges or clamp type flanges) hold a seal under thermal conditions typical of nightly shut down, and the practicality of using these flanges on high maintenance components. In addition, the flanges were thermally shocked to simulate cold starting the system. Instrumentation such as vortex shedding and ultrasonic flow meters were tested alongside each other, and compared with flow measurements from calibration tanks in the flow loop.

  14. Preparation and thermal properties of Glauber’s salt-based phase-change materials for Qinghai-Tibet Plateau solar greenhouses

    Science.gov (United States)

    Jiang, Zipeng; Tie, Shengnian

    2017-07-01

    This paper reports the preparation and characterization of eutectic Glauber’s salt-based composite, phase-change materials (G-PCMs). PCMs were prepared using industrial-grade sodium sulfate decahydrate (Na2SO4 ṡ 10H2O) as the basic material. Other salts were added to obtain the eutectic Glauber’s salt-based PCMs with phase-change temperatures of 25∘C, 15∘C and 10∘C. The modification of the G-PCMs was designed using the same experimental method to select the efficient nucleating, thickening and thermal conductive agents. The results show that borax can be an effective nucleating agent, sodium carboxymethyl cellulose is an excellent thickener and carbon powder is a good thermal conductive agent. The phase-change temperature, latent heat and thermal conductivity of the three different PCMs are 23.9∘C, 15.4∘C and 9.5∘C; 179.6, 129 and 116.2 J/g; and 1.02, 1.10 and 1.23 W/(m K), respectively. These PCMs possess suitable phase-change temperature, high latent heat and good thermal conductivity, and can be used in Qinghai-Tibet Plateau agricultural solar greenhouses.

  15. Revegetation of flue gas desulfurization sludge pond disposal sites

    International Nuclear Information System (INIS)

    Artiola, J.F.

    1994-12-01

    A comprehensive search of published literature was conducted to summarize research undertaken to date on revegetation of flue gas desulfurization (FGD) waste disposal ponds. A review of the physical and chemical properties of FGD sludges and wastes with similar characteristics is also included in order to determine the advantages and limitations of FGD sludge for plant growth. No specific guidelines have been developed for the revegetation of FGD sludge disposal sites. Survey studies showed that the wide-ranging composition of FGD wastes was determined primarily by the sulfur dioxide and other flue gas scrubbing processes used at powerplants. Sulfate rich (>90%CaSO 4 ) FGD sludges are physically and chemically more stable, and thus more amenable to revegetation. Because of lack of macronutrients and extremely limited microbial activity, FBD sludge ponds presented a poor plant growth environment without amendment. Studies showed the natural process of inoculation of the FGD sludge with soil microbes that promote plant growth be can after disposal but proceeded slowly. Revegetation studies reviewed showed that FGD sludges amended with soils supported a wider variety of plant species better and longer than abandoned FGD ponds. Two major types of plants have been successful in revegetation of FGD waste ponds and similar wastes: salt-tolerant plants and aquatic plants. A comprehensive list of plant species with potential for regetation of FGD sludge disposal pond sites is presented along with successful revegetation techniques

  16. The Pond Is Our Laboratory

    Science.gov (United States)

    Marchewka, Barbara Turco

    1978-01-01

    This science teacher's laboratory is a pond within walking distance of his school that provides a stimulating environment for exploring the natural world. With simple materials students practice making careful observations, taking measurements and compiling and graphing information for their science studies. They also extend their pond experiences…

  17. Carbonate deposition on tail feathers of ruddy ducks using evaporation ponds

    Science.gov (United States)

    Euliss, N.H.; Jarvis, R.L.; Gilmer, D.S.

    1989-01-01

    Substantial carbonate deposits were observed on rectrices of Ruddy Ducks (Oxyura jamaicensis) collected during 1982-1984 on evaporation ponds in the San Joaquin Valley, California. Carbonate deposits were composed of about 75% aragonite and 25% calcite, both polymorphous forms of CaCO3. Significantly more carbonate deposits were observed on Ruddy Ducks as length of exposure to agricultural drain water increased, during the 1983-1984 field season when salt concentrations in the ponds were higher, and in certain evaporation-pond systems.

  18. Solar Spots - Activities to Introduce Solar Energy into the K-8 Curricula.

    Science.gov (United States)

    Longe, Karen M.; McClelland, Michael J.

    Following an introduction to solar technology which reviews solar heating and cooling, passive solar systems (direct gain systems, thermal storage walls, sun spaces, roof ponds, and convection loops), active solar systems, solar electricity (photovoltaic and solar thermal conversion systems), wind energy, and biomass, activities to introduce solar…

  19. Effects of human disturbance on waterbird nesting and reproductive success at restoration pond SF2, south San Francisco Bay, California

    Science.gov (United States)

    Ackerman, Joshua T.; Herzog, Mark P.; Hartman, Christopher A.

    2014-01-01

    To offset for the loss of managed pond habitat during restoration of wetlands to tidal marsh, the South Bay Salt Pond (SBSP) Restoration Project is enhancing some of the remaining ponds by constructing islands for roosting and nesting waterbirds. Among these wetland habitats, the SBSP Restoration Project also is installing walking trails and viewing platforms in an effort to bring the public closer to nature. In winter of 2010–11, the SBSP Restoration Project constructed 30 islands in Pond SF2 and walking trails and viewing platforms around the edge of the pond. The restoration project partners acknowledged that human disturbance could detrimentally affect nesting and roosting waterbirds. Although optimal buffer distances and potential for human disturbance were unknown, islands in Pond SF2, nevertheless, were designed with built-in buffers of greater than 300 feet (91 meters) from a trail and 600 feet (182 meters) from a viewing platform in order to minimize potential human disturbances.

  20. Novel thixotropic gel electrolytes based on dicationic bis-imidazolium salts for quasi-solid-state dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jun Young [Department of Polymer Science and Engineering, SungKyunKwan University, Suwon, Kyunggi-do 440-746 (Korea); Functional Polymer Lab., Korea Institute of Science and Technology, Seoul 136-791 (Korea); Kim, Tae Ho [Department of Polymer Science and Engineering, SungKyunKwan University, Suwon, Kyunggi-do 440-746 (Korea); Kim, Dong Young; Park, Nam-Gyu [Energy Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea); Ahn, Kwang-Duk [Functional Polymer Lab., Korea Institute of Science and Technology, Seoul 136-791 (Korea)

    2008-01-03

    Novel thixotropic gel electrolytes have been successfully prepared by utilizing oligomeric poly(ethylene oxide) (PEO)-based bis-imidazolium diiodide salts and hydrophilic silica nanoparticles for application in quasi-solid-state dye-sensitized solar cells (DSSCs). The thixotropic gel-state of the ionic liquid-based composite electrolytes is confirmed by observing the typical hysteresis loop and temporary hydrogen bonding. On using the PEO-based composite electrolyte, a quasi-solid-state DSSC exhibited highly improved properties such as easy penetration of the electrolyte into the cell without leakage, long-term stability, high open-circuit voltage without the use of 4-tert-butylpyridine, and a high energy-conversion efficiency of 5.25% under AM 1.5 illumination (100 mW cm{sup -2}). (author)

  1. Novel thixotropic gel electrolytes based on dicationic bis-imidazolium salts for quasi-solid-state dye-sensitized solar cells

    Science.gov (United States)

    Kim, Jun Young; Kim, Tae Ho; Kim, Dong Young; Park, Nam-Gyu; Ahn, Kwang-Duk

    Novel thixotropic gel electrolytes have been successfully prepared by utilizing oligomeric poly(ethylene oxide) (PEO)-based bis-imidazolium diiodide salts and hydrophilic silica nanoparticles for application in quasi-solid-state dye-sensitized solar cells (DSSCs). The thixotropic gel-state of the ionic liquid-based composite electrolytes is confirmed by observing the typical hysteresis loop and temporary hydrogen bonding. On using the PEO-based composite electrolyte, a quasi-solid-state DSSC exhibited highly improved properties such as easy penetration of the electrolyte into the cell without leakage, long-term stability, high open-circuit voltage without the use of 4- tert-butylpyridine, and a high energy-conversion efficiency of 5.25% under AM 1.5 illumination (100 mW cm -2).

  2. Diffusion of single oxidation pond

    Directory of Open Access Journals (Sweden)

    Song Ruo-Yuan

    2016-01-01

    Full Text Available The hydraulic characteristic of an oxidation pond was studied by the tracer experiment, and an empirical formula of Peclet number was obtained, which can be well applied to the model of plug flow reactor with longitudinal diffusion.

  3. Par Pond vegetation status 1996

    International Nuclear Information System (INIS)

    Mackey, H.E. Jr.; Riley, R.S.

    1996-12-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the newly emergent, shoreline aquatic plant communities of Par Pond began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level. These surveys continued in July, September, and late October, 1995, and into the early spring and late summer of 1996. Communities similar to the pre-drawdown, Par Pond aquatic plant communities continue to become re-established. Emergent beds of maidencane, lotus, waterlily, watershield, and Pontederia are extensive and well developed. Measures of percent cover, width of beds, and estimates of area of coverage with satellite data indicate regrowth within two years of from 40 to 60% of levels prior to the draw down. Cattail occurrence continued to increase during the summer of 1996, especially in the former warm arm of Par Pond, but large beds common to Par Pond prior to the draw down still have not formed. Lotus has invaded and occupies many of the areas formerly dominated by cattail beds. To track the continued development of macrophytes in Par Pond, future surveys through the summer and early fall of 1997, along with the evaluation of satellite data to map the extent of the macrophyte beds of Par Pond, are planned

  4. Metagenomic Sequence of Prokaryotic Microbiota from an Intermediate-Salinity Pond of a Saltern in Isla Cristina, Spain

    OpenAIRE

    Fernández, Ana B.; León, María José; Vera, Blanca; Sánchez-Porro, Cristina; Ventosa, Antonio

    2014-01-01

    Marine salterns are artificial multipond systems designed for the commercial production of salt by evaporation of seawater. We report here the metagenomic sequence of the prokaryotic microbiota of a pond with intermediate salinity (21% total salts) of a saltern located in Isla Cristina, Huelva, southwest Spain.

  5. Metagenomic sequence of prokaryotic microbiota from an intermediate-salinity pond of a saltern in isla cristina, Spain.

    Science.gov (United States)

    Fernández, Ana B; León, María José; Vera, Blanca; Sánchez-Porro, Cristina; Ventosa, Antonio

    2014-02-13

    Marine salterns are artificial multipond systems designed for the commercial production of salt by evaporation of seawater. We report here the metagenomic sequence of the prokaryotic microbiota of a pond with intermediate salinity (21% total salts) of a saltern located in Isla Cristina, Huelva, southwest Spain.

  6. 2101-M pond closure plan

    International Nuclear Information System (INIS)

    1993-06-01

    This document describes activities for the closure of a surface impoundment (2101-M Pond) at the Hanford Site. The 2101-H Pond was initially constructed in 1953 to serve as a drainage collection area for the 2101-H Building. (Until the Basalt Waste Isolation Project (BWIP) Laboratory was constructed in the 2101-M Building in 1979--1981, the only source contributing discharge to the pond was condensate water from the 2101-H Building heating, ventilation, and air conditioning (HVAC) system. The drains for the BWIP Laboratory rooms were plumbed into a 4-in., cast-iron, low-pressure drain pipe that carries waste water from the HVAC system to the pond. During the active life of the BWIP Laboratory, solutions of dissolved barium in groundwater samples were discharged to the 2101-M Pond via the laboratory drains. As a result of the discharges, a Part A permit application was initially submitted to the Washington State Department of Ecology (Ecology) in August 1986 which designates the 2101-M Pond as a surface impoundment

  7. The use of electro-deoxidation in molten salts to reduce the energy consumption of solar grade silicon and increase the output of PV solar cells

    Directory of Open Access Journals (Sweden)

    Paul R. Coxon

    2015-12-01

    Full Text Available Solar photovoltaics, based upon silicon, are the most popular form of solar cell with efficiencies around 20%. These efficiencies can be further increased by employing light trapping schemes to minimise optical losses through scattering and reflection which enhances the amount of light absorbed and number of photo-carriers generated. Typical approaches employ antireflection coatings (ARCs or texturise the surface of the silicon disks, so that the structure consists of an array of needles which can absorb most of the light. Usually, these structures are created by leaching the silicon with hydrofluoric-based acids or by reactive ion etching (RIE methods. This paper reviews some of the methods for improving the energy efficiency of silicon production, and describes the use of electro-deoxidation of SiO2 layers, on silicon, in molten calcium chloride to form nano-porous black silicon (b-Si structures. By coating b-Si surface with TiO2, a common ARC, extremely black surfaces with negligible reflectance of about 0.1%, are produced, which can have applications for low-cost high efficiency solar cells.

  8. Toxicity of road salt to Nova Scotia amphibians.

    Science.gov (United States)

    Collins, Sara J; Russell, Ronald W

    2009-01-01

    The deposition of chemical pollutants into roadside wetlands from runoff is a current environmental concern. In northern latitudes, a major pollutant in runoff water is salt (NaCl), used as de-icing agents. In this study, 26 roadside ponds were surveyed for amphibian species richness and chloride concentration. Acute toxicity tests (LC(50)) were performed on five locally common amphibian species using a range of environmentally significant NaCl concentrations. Field surveys indicated that spotted salamanders (Ambystoma maculatum) and wood frogs (Rana sylvatica) did not occupy high chloride ponds. American toads (Bufo americanus) showed no pond preference based on chloride concentration. Acute toxicity tests showed spotted salamanders and wood frogs were most sensitive to chloride, and American toads were the least. Spring peepers (Pseudacris crucifer) and green frogs (Rana clamitans) showed intermediate sensitivities. We concluded that chloride concentrations in ponds due to application of de-icing salts, influenced community structure by excluding salt intolerant species.

  9. A Closer Look on Spatiotemporal Variations of Dissolved Oxygen in Waste Stabilization Ponds Using Mixed Models

    Directory of Open Access Journals (Sweden)

    Long Ho

    2018-02-01

    Full Text Available Dissolved oxygen is an essential controlling factor in the performance of facultative and maturation ponds since both take many advantages of algal photosynthetic oxygenation. The rate of this photosynthesis strongly depends on the time during the day and the location in a pond system, whose roles have been overlooked in previous guidelines of pond operation and maintenance (O&M. To elucidate these influences, a linear mixed effect model (LMM was built on the data collected from three intensive sampling campaigns in a waste stabilization pond in Cuenca, Ecuador. Within two parallel lines of facultative and maturation ponds, nine locations were sampled at two depths in each pond. In general, the output of the mixed model indicated high spatial autocorrelations of data and wide spatiotemporal variations of the oxygen level among and within the ponds. Particularly, different ponds showed different patterns of oxygen dynamics, which were associated with many factors including flow behavior, sludge accumulation, algal distribution, influent fluctuation, and pond function. Moreover, a substantial temporal change in the oxygen level between day and night, from zero to above 20 mg O2·L−1, was observed. Algal photosynthetic activity appeared to be the main reason for these variations in the model, as it was facilitated by intensive solar radiation at high altitude. Since these diurnal and spatial patterns can supply a large amount of useful information on pond performance, insightful recommendations on dissolved oxygen (DO monitoring and regulations were delivered. More importantly, as a mixed model showed high predictive performance, i.e., high goodness-of-fit (R2 of 0.94, low values of mean absolute error, we recommended this advanced statistical technique as an effective tool for dealing with high autocorrelation of data in pond systems.

  10. Blogging from North Pond

    Science.gov (United States)

    Marziali, C. G.; Edwards, K. J.

    2009-12-01

    Sea going research expeditions provide an ideal opportunity for outreach through blogs: the finite duration limits the author's commitment; scientists are usually in a remote location with fewer distractions; and fieldwork is visual and interesting to describe. Over four weeks this winter, Katrina Edwards of USC authored a blog about her deep-sea drilling expedition to North Pond, a depression in the ocean crust in the mid-Atlantic. She emailed daily dispatches and photos to USC Media Relations, which maintained a (still accessible) blog. Written for the general public, the blog quickly attracted interest from lay readers as well as from media organizations. Scientific American carried the blog on its web site, and the National Science Foundation linked to it in its "Science 360" electronic news digest. The blog also led to a Q&A with Edwards in the widely-read "Behind the Scenes" feature of LiveScience. Interest from science bloggers and National Geographic towards the end suggests that the blog could have expanded its reach given more time: expeditions lasting between six weeks and three months, such as occur during ocean drilling expeditions, would appear to be ideal candidates for a blog. Most importantly, the blog educated readers about the importance to planetary life of what Edwards calls the "intraterrestrials": the countless microbes that inhabit the oceanic crust and influence major chemical and biological cycles. Considering that the subjects of the expedition were invisible critters in a pitch-dark place, the blog shows what can be accomplished by scientists and institutions committed to public outreach.

  11. Operation of roof pond systems, considering its advantages and disadvantages

    Energy Technology Data Exchange (ETDEWEB)

    Noohi, Samira; Rezaei, Davood [Faculty of engineering, Zanjan University (Iran, Islamic Republic of)], email: noohi.sam@gmail.com, email: d_rezaei@znu.ac.ir

    2011-07-01

    With the coming shortage of fossil fuels it is important to develop energy efficient buildings to reduce both energy consumption and pollution at the same time. The roof pond system is a passive solar system which gathers heat from the sun and can distribute it to the living space to cool it or heat it by changing the operating cycle. Although not recent, this method has not been widely implemented due to certain limitations and the aim of this paper is to assess the different advantages and disadvantages of this system over other passive solar heating systems. This study showed that a roof pond has a low impact on the building, provides controllable energy delivery and variations in indoor temperature are low; however it requires an active solar system as a backup and vegetation can limit sunlight penetration. This study highlighted that the efficiency of the roof system pond depends on climate conditions and that it is best suited to lower latitude and low humidity areas.

  12. Thermal evolutions of two kinds of melt pond with different salinity

    Science.gov (United States)

    Kim, Joo-Hong; Wilkinson, Jeremy; Moon, Woosok; Hwang, Byongjun; Granskog, Mats

    2016-04-01

    Melt ponds are water pools on sea ice. Their formation reduces ice surface albedo and alter surface energy balance, by which the ice melting and freezing processes are regulated. Thus, better understanding of their radiative characteristics has been vital to improve the simulation of melting/freezing of sea ice in numerical models. A melt pond would preserve nearly fresh water if it formed on multi-year ice and no flooding of sea water occurred, whereas a melt pond would contain more salty water if it formed on thinner and porous first-year ice, if there were an inflow of sea water by streams or cracks. One would expect that the fluid dynamic/thermodynamic properties (e.g., turbulence, stability, etc.) of pond water are influenced by the salinity, so that the response of pond water to any heat input (e.g., shortwave radiation) would be different. Therefore, better understanding of the salinity-dependent thermal evolution also has significant potential to improve the numerical simulation of the sea ice melting/freezing response to radiative thermal forcing. To observe and understand the salinity-dependent thermal evolution, two ice mass balance buoys (IMBs) were deployed in two kinds (fresh and salty) of melt pond on a same ice floe on 13 August 2015 during Araon Arctic cruise. The thermistor chain, extending from the air through the pond and ice into the sea water, was deployed through a drilled borehole inside the pond. Besides, the IMBs were also accompanied with three broadband solar radiation sensors (two (up and down) in the air over melt pond and one upward-looking under sea ice) to measure the net shortwave radiation at the pond surface and the penetrating solar radiation through ice. Also, the web camera was installed to observe any updates in the conditions of equipment and surrounding environment (e.g., weather, surface state, etc.). On the date of deployment, the fresh pond had salinity of 2.3 psu, light blue color, lots of slush ice particles which

  13. Microbial population responses in three stratified Antarctic meltwater ponds during the autumn freeze

    DEFF Research Database (Denmark)

    Safi, Karl; Hawes, Ian; Sorrell, Brian Keith

    2012-01-01

    The planktonic microbial communities of three meltwater ponds, located on the McMurdo Ice Shelf, were investigated from the end of January 2008 to early April, during which almost the entire pond volumes froze. The ponds were comprised of an upper mixed layer overlying a salt-stabilized density g...... for increasing heterotrophy within the remaining microbial communities, although all components of the food web eventually decline as the final freeze approaches....... role of autotrophic and heterotrophic microplankton within the ponds. The results showed that microbial groups responded to the onset of winter by declining in abundance, though an exception was the appearance of filamentous cyanobacteria in the water column in March. As freezing progressed, autotrophs...... declined more rapidly than heterotrophs and grazing rates and abundances of mixotrophic and heterotrophic organisms increased. Grazing pressure on bacteria and picophytoplankton also increased, in part explaining their decline over time. The results indicate that stressors imposed during freezing select...

  14. Where Does Road Salt Go - a Static Salt Model

    Science.gov (United States)

    Yu, C. W.; Liu, F.; Moriarty, V. W.

    2017-12-01

    Each winter, more than 15 million tons of road salt is applied in the United States for the de-icing purpose. Considerable amount of chloride in road salt flows into streams/drainage systems with the snow melt runoff and spring storms, and eventually goes into ecologically sensitive low-lying areas in the watershed, such as ponds and lakes. In many watersheds in the northern part of US, the chloride level in the water body has increased significantly in the past decades, and continues an upward trend. The environmental and ecological impact of the elevated chloride level can no longer be ignored. However although there are many studies on the biological impact of elevated chloride levels, there are few investigations on how the spatially distributed road salt application affects various parts of the watershed. In this presentation, we propose a static road salt model as a first-order metric to address spacial distribution of salt loading. Derived from the Topological Wetness Index (TWI) in many hydrological models, this static salt model provides a spatial impact as- sessment of road salt applications. To demonstrate the effectiveness of the static model, National Elevation Dataset (NED) of ten-meter resolution of Lake George watershed in New York State is used to generate the TWI, which is used to compute a spatially dis- tributed "salt-loading coefficient" of the whole watershed. Spatially varying salt applica- tion rate is then aggregated, using the salt-loading coefficients as weights, to provide salt loading assessments of streams in the watershed. Time-aggregated data from five CTD (conductivity-temperature-depth) sensors in selected streams are used for calibration. The model outputs and the sensor data demonstrate a strong linear correlation, with the R value of 0.97. The investigation shows that the static modeling approach may provide an effective method for the understanding the input and transport of road salt to within watersheds.

  15. 216-B-3 expansion ponds closure plan

    Energy Technology Data Exchange (ETDEWEB)

    1994-10-01

    This document describes the activities for clean closure under the Resource Conservation and Recovery Act of 1976 (RCRA) of the 216-B-3 Expansion Ponds. The 216-B-3 Expansion Ponds are operated by the US Department of Energy, Richland Operations Office (DOE-RL) and co-operated by Westinghouse Hanford Company (Westinghouse Hanford). The 216-B-3 Expansion Ponds consists of a series of three earthen, unlined, interconnected ponds that receive waste water from various 200 East Area operating facilities. The 3A, 3B, and 3C ponds are referred to as Expansion Ponds because they expanded the capability of the B Pond System. Waste water (primarily cooling water, steam condensate, and sanitary water) from various 200 East Area facilities is discharged to the Bypass pipe (Project X-009). Water discharged to the Bypass pipe flows directly into the 216-B-3C Pond. The ponds were operated in a cascade mode, where the Main Pond overflowed into the 3A Pond and the 3A Pond overflowed into the 3C Pond. The 3B Pond has not received waste water since May 1985; however, when in operation, the 3B Pond received overflow from the 3A Pond. In the past, waste water discharges to the Expansion Ponds had the potential to have contained mixed waste (radioactive waste and dangerous waste). The radioactive portion of mixed waste has been interpreted by the US Department of Energy (DOE) to be regulated under the Atomic Energy Act of 1954; the dangerous waste portion of mixed waste is regulated under RCRA.

  16. 216-B-3 expansion ponds closure plan

    International Nuclear Information System (INIS)

    1994-10-01

    This document describes the activities for clean closure under the Resource Conservation and Recovery Act of 1976 (RCRA) of the 216-B-3 Expansion Ponds. The 216-B-3 Expansion Ponds are operated by the US Department of Energy, Richland Operations Office (DOE-RL) and co-operated by Westinghouse Hanford Company (Westinghouse Hanford). The 216-B-3 Expansion Ponds consists of a series of three earthen, unlined, interconnected ponds that receive waste water from various 200 East Area operating facilities. The 3A, 3B, and 3C ponds are referred to as Expansion Ponds because they expanded the capability of the B Pond System. Waste water (primarily cooling water, steam condensate, and sanitary water) from various 200 East Area facilities is discharged to the Bypass pipe (Project X-009). Water discharged to the Bypass pipe flows directly into the 216-B-3C Pond. The ponds were operated in a cascade mode, where the Main Pond overflowed into the 3A Pond and the 3A Pond overflowed into the 3C Pond. The 3B Pond has not received waste water since May 1985; however, when in operation, the 3B Pond received overflow from the 3A Pond. In the past, waste water discharges to the Expansion Ponds had the potential to have contained mixed waste (radioactive waste and dangerous waste). The radioactive portion of mixed waste has been interpreted by the US Department of Energy (DOE) to be regulated under the Atomic Energy Act of 1954; the dangerous waste portion of mixed waste is regulated under RCRA

  17. Flocculation of retention pond water

    International Nuclear Information System (INIS)

    Hart, B.T.; McGregor, R.J.

    1982-05-01

    An integral part of the water management strategy proposed by Ranger Uranium Mining Pty. Ltd. involves the collection of runoff water in a series of retention ponds. This water will subsequently be used in the uranium milling plant or released to Magela Creek. Runoff water collected during the wet season caused a section of Magela Creek to become turbid when it was released. The eroded material causing the turbidity was very highly dispersed and showed little tendency to sediment out in the retention ponds. Results of a preliminary study to determine the feasibility of clarifying retention pond water by flocculation with alum are presented. A concentration of 30 Mg/L alum reduced turbidity from an initial 340 NTU to less than 30 NTU in four hours

  18. Comparison of prokaryotic community structure from Mediterranean and Atlantic saltern concentrator ponds by a metagenomic approach

    Directory of Open Access Journals (Sweden)

    Ana Beatriz eFernández

    2014-05-01

    Full Text Available We analyzed the prokaryotic community structure of a saltern pond with 21 % total salts located in Isla Cristina, Huelva, Southwest Spain, close to the Atlantic ocean coast. For this purpose, we constructed a metagenome (designated as IC21 obtained by pyrosequencing consisting of 486 Mb with an average read length of 397 bp and compared it with other metagenomic datasets obtained from ponds with 19, 33 and 37 % total salts acquired from Santa Pola marine saltern, located in Alicante, East Spain, on the Mediterranean coast. Although the salinity in IC21 is closer to the pond with 19 % total salts from Santa Pola saltern (designated as SS19, IC21 is more similar at higher taxonomic levels to the pond with 33 % total salts from Santa Pola saltern (designated as SS33, since both are predominated by the phylum Euryarchaeota. However, there are significant differences at lower taxonomic levels where most sequences were related to the genus Halorubrum in IC21 and to Haloquadratum in SS33. Within the Bacteroidetes, the genus Psychroflexus is the most abundant in IC21 while Salinibacter dominates in SS33. Sequences related to bacteriorhodopsins and halorhodopsins correlate with the abundance of Haloquadratum in Santa Pola SS19 to SS33 and of Halorubrum in Isla Cristina IC21 dataset, respectively. Differences in composition might be attributed to local ecological conditions since IC21 showed a decrease in the number of sequences related to the synthesis of compatible solutes and in the utilization of phosphonate.

  19. Par Pond Fish, Water, and Sediment Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Paller, M.H. [Westinghouse Savannah River Company, AIKEN, SC (United States); Wike, L.D.

    1996-06-01

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

  20. Par Pond Fish, Water, and Sediment Chemistry

    International Nuclear Information System (INIS)

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

    1996-06-01

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

  1. Liner used in tailings ponds

    International Nuclear Information System (INIS)

    Dinchak, W.G.

    1984-01-01

    A composite liner has been developed for use in hazardous waste impoundments and in tailings ponds where uranium is involved. The liner offers a high degree of reliability against seepage, is durable, and provides a firm working surface. The advantages of the liner are discussed

  2. Concentrated Brine Treatment using New Energy in Coal Mine Evaporation Ponds

    Science.gov (United States)

    Li, Ting; Li, Jingfeng

    2017-12-01

    Recently, more and more coal mine water is being advanced treated and reused in China. The concentrated brine that results from advanced treatment methods can only be evaporated in an evaporation pond. Because of limited treatment capabilities and winter freezing, evaporation ponds often overflow, causing environment contamination. In this paper, based on analysis of brine water quality and economic-technical feasibility, we present a suitable treatment method for brine in evaporation ponds as electrodialysis using solar energy. In addition, we propose a new system to treat brine in coal mine evaporation ponds, which is powered by solar and wind. The operating efficiency of this treatment system proposed in this paper can meet the concentrated brine treatment demands in most coal mines in western mining areas of China and it places the photovoltaic power generation plates on the surface of the evaporation pond on a fixed floating island, which reduces any risk associated with land acquisition. This system can enhance brine treatment efficiency, requires a reduced evaporation pond area, increases the utilization of coal mine water, and minimizes the risk of environment contamination.

  3. ELECTROKINETIC DENSIFICATION OF COAL FINES IN WASTE PONDS

    Energy Technology Data Exchange (ETDEWEB)

    E. James Davis

    1999-12-18

    The objective of this research was to demonstrate that electrokinetics can be used to remove colloidal coal and mineral particles from coal-washing ponds and lakes without the addition of chemical additives such as salts and polymeric flocculants. The specific objectives were: Design and develop a scaleable electrophoresis apparatus to clarify suspensions of colloidal coal and clay particles; Demonstrate the separation process using polluted waste water from the coal-washing facilities at the coal-fired power plants in Centralia, WA; Develop a mathematical model of the process to predict the rate of clarification and the suspension electrical properties needed for scale up.

  4. A temperature rise equation for predicting environmental impact and performance of cooling ponds

    Energy Technology Data Exchange (ETDEWEB)

    Serag-Eldin, M.A. [American Univ. in Cairo, Cairo (Egypt). Dept. of Mechanical Engineering

    2009-07-01

    Cooling ponds are used to cool the condenser water used in large central air-conditioning systems. However, larger cooling loads can often increase pond surface evaporation rates. A temperature-rise energy equation was developed to predict temperature rises in cooling ponds subjected to heating loads. The equation was designed to reduce the need for detailed meteorological data as well as to determine the required surface area and depth of the pond for any given design criteria. Energy equations in the presence and absence of cooling loads were subtracted from each other to determine increases in pond temperature resulting from the cooling load. The energy equations include solar radiation, radiation exchange with sky and surroundings, heat convection from the surface, evaporative cooling, heat conducted to the walls, and rate of change of water temperature. Results of the study suggested that the environmental impact and performance of the cooling pond is a function of temperature only. It was concluded that with the aid of the calculated flow field and temperature distribution, the method can be used to position sprays in order to produce near-uniform pond temperatures. 10 refs., 12 figs.

  5. thermic oil and molten salt

    African Journals Online (AJOL)

    Boukelia T.E, Mecibah M.S and Laouafi A

    1 mai 2016 ... [27] Zavoico, AB. Solar Power Tower Design Basis Document. Tech. rep, Sandia National. Laboratories, SAND2001-2100, 2001. How to cite this article: Boukelia T.E, Mecibah M.S and Laouafi A. Performance simulation of parabolic trough solar collector using two fluids (thermic oil and molten salt).

  6. Tidal day organic and inorganic material flux of ponds in the Liberty Island freshwater tidal wetland.

    Science.gov (United States)

    Lehman, Peggy W; Mayr, Shawn; Liu, Leji; Tang, Alison

    2015-01-01

    The loss of inorganic and organic material export and habitat produced by freshwater tidal wetlands is hypothesized to be an important contributing factor to the long-term decline in fishery production in San Francisco Estuary. However, due to the absence of freshwater tidal wetlands in the estuary, there is little information on the export of inorganic and organic carbon, nutrient or phytoplankton community biomass and the associated mechanisms. A single-day study was conducted to assess the potential contribution of two small vegetated ponds and one large open-water pond to the inorganic and organic material flux within the freshwater tidal wetland Liberty Island in San Francisco Estuary. The study consisted of an intensive tidal day (25.5 h) sampling program that measured the flux of inorganic and organic material at three ponds using continuous monitoring of flow, chlorophyll a, turbidity and salt combined with discrete measurements of phytoplankton community carbon, total and dissolved organic carbon and nutrient concentration at 1.5 h intervals. Vegetated ponds had greater material concentrations than the open water pond and, despite their small area, contributed up to 81% of the organic and 61% of the inorganic material flux of the wetland. Exchange between ponds was important to wetland flux. The small vegetated pond in the interior of the wetland contributed as much as 72-87% of the total organic carbon and chlorophyll a and 10% of the diatom flux of the wetland. Export of inorganic and organic material from the small vegetated ponds was facilitated by small-scale topography and tidal asymmetry that produced a 40% greater material export on ebb tide. The small vegetated ponds contrasted with the large open water pond, which imported 29-96% of the inorganic and 4-81% of the organic material into the wetland from the adjacent river. This study identified small vegetated ponds as an important source of inorganic and organic material to the wetland and the

  7. Microbial reduction of [Co(III)–EDTA]− by Bacillus licheniformis SPB-2 strain isolated from a solar salt pan

    International Nuclear Information System (INIS)

    Paraneeiswaran, Arunachalam; Shukla, Sudhir K.; Prashanth, K.; Rao, T. Subba

    2015-01-01

    Graphical abstract: - Highlights: • Bacillus licheniformis SPB-2 was used in the bioremediation of [Co(III)–EDTA] − . • The bacterial biomass adsorbed the Co–EDTA complex after its reduction. • [Co(III)–EDTA] − complex showed Bacillus spore inducing property. • B. licheniformis SPB-2 showed significantly radio-tolerance (D 10 = 250 Gy). - Abstract: Naturally stressed habitats are known to be repositories for novel microorganisms with potential bioremediation applications. In this study, we isolated a [Co(III)–EDTA] − reducing bacterium Bacillus licheniformis SPB-2 from a solar salt pan that is exposed to constant cycles of hydration and desiccation in nature. [Co(III)–EDTA] − generated during nuclear waste management process is difficult to remove from the waste due to its high stability and solubility. It is reduced form i.e. [Co(II)–EDTA] 2− is less stable though it is toxic. This study showed that B. licheniformis SPB-2 reduced 1 mM [Co(III)–EDTA] − in 14 days when grown in a batch mode. However, subsequent cycles showed an increase in the reduction activity, which was observed up to four cycles. Interestingly, the present study also showed that [Co(III)–EDTA] − acted as an inducer for B. licheniformis SPB-2 spore germination. Vegetative cells germinated from the spores were found to be involved in [Co(III)–EDTA] − reduction. More detailed investigations showed that after [Co(III)–EDTA] − reduction, i.e. [Co(II)–EDTA] 2− complex was removed by B. licheniformis SPB-2 from the bulk liquid by adsorption phenomenon. The bacterium showed a D 10 value (radiation dose required to kill 90% cells) of ∼250 Gray (Gy), which signifies the potential use of B. licheniformis SPB-2 for bioremediation of moderately active nuclear waste

  8. Microbial reduction of [Co(III)–EDTA]{sup −} by Bacillus licheniformis SPB-2 strain isolated from a solar salt pan

    Energy Technology Data Exchange (ETDEWEB)

    Paraneeiswaran, Arunachalam [Departartment of Biotechnology, Pondicherry University, Puducherry (India); Shukla, Sudhir K. [Biofouling and Biofilm Processes Section, Water and Steam Chemistry Division, BARC Facilities, Kalpakkam 603102 (India); Homi Bhabha National Institute, Mumbai 400094 (India); Prashanth, K. [Departartment of Biotechnology, Pondicherry University, Puducherry (India); Rao, T. Subba, E-mail: subbarao@igcar.gov.in [Biofouling and Biofilm Processes Section, Water and Steam Chemistry Division, BARC Facilities, Kalpakkam 603102 (India); Homi Bhabha National Institute, Mumbai 400094 (India)

    2015-02-11

    Graphical abstract: - Highlights: • Bacillus licheniformis SPB-2 was used in the bioremediation of [Co(III)–EDTA]{sup −}. • The bacterial biomass adsorbed the Co–EDTA complex after its reduction. • [Co(III)–EDTA]{sup −} complex showed Bacillus spore inducing property. • B. licheniformis SPB-2 showed significantly radio-tolerance (D{sub 10} = 250 Gy). - Abstract: Naturally stressed habitats are known to be repositories for novel microorganisms with potential bioremediation applications. In this study, we isolated a [Co(III)–EDTA]{sup −} reducing bacterium Bacillus licheniformis SPB-2 from a solar salt pan that is exposed to constant cycles of hydration and desiccation in nature. [Co(III)–EDTA]{sup −} generated during nuclear waste management process is difficult to remove from the waste due to its high stability and solubility. It is reduced form i.e. [Co(II)–EDTA]{sup 2−} is less stable though it is toxic. This study showed that B. licheniformis SPB-2 reduced 1 mM [Co(III)–EDTA]{sup −} in 14 days when grown in a batch mode. However, subsequent cycles showed an increase in the reduction activity, which was observed up to four cycles. Interestingly, the present study also showed that [Co(III)–EDTA]{sup −} acted as an inducer for B. licheniformis SPB-2 spore germination. Vegetative cells germinated from the spores were found to be involved in [Co(III)–EDTA]{sup −} reduction. More detailed investigations showed that after [Co(III)–EDTA]{sup −} reduction, i.e. [Co(II)–EDTA]{sup 2−} complex was removed by B. licheniformis SPB-2 from the bulk liquid by adsorption phenomenon. The bacterium showed a D{sub 10} value (radiation dose required to kill 90% cells) of ∼250 Gray (Gy), which signifies the potential use of B. licheniformis SPB-2 for bioremediation of moderately active nuclear waste.

  9. The Ruminant and the Pond

    OpenAIRE

    Lajarin-Encina, Aitor

    2015-01-01

    The Ruminant and the Pond presents a group of paintings and a film that explore contemporary psycho-social conditions through fictional narratives. Paintings and film explore territories of thinking and emotion engaging the audience in subjective digressions related to ideas of artificiality, relativeness, absurdity, futility or alienation in relation to intersubjective reality perception, production and representation. At the same time the project delves in the specific relationship existin...

  10. Effects of pond draining on biodiversity and water quality of farm ponds.

    Science.gov (United States)

    Usio, Nisikawa; Imada, Miho; Nakagawa, Megumi; Akasaka, Munemitsu; Takamura, Noriko

    2013-12-01

    Farm ponds have high conservation value because they contribute significantly to regional biodiversity and ecosystem services. In Japan pond draining is a traditional management method that is widely believed to improve water quality and eradicate invasive fish. In addition, fishing by means of pond draining has significant cultural value for local people, serving as a social event. However, there is a widespread belief that pond draining reduces freshwater biodiversity through the extirpation of aquatic animals, but scientific evaluation of the effectiveness of pond draining is lacking. We conducted a large-scale field study to evaluate the effects of pond draining on invasive animal control, water quality, and aquatic biodiversity relative to different pond-management practices, pond physicochemistry, and surrounding land use. The results of boosted regression-tree models and analyses of similarity showed that pond draining had little effect on invasive fish control, water quality, or aquatic biodiversity. Draining even facilitated the colonization of farm ponds by invasive red swamp crayfish (Procambarus clarkii), which in turn may have detrimental effects on the biodiversity and water quality of farm ponds. Our results highlight the need for reconsidering current pond management and developing management plans with respect to multifunctionality of such ponds. Efectos del Drenado de Estanques sobre la Biodiversidad y la Calidad del Agua en Estanques de Cultivo. © 2013 Society for Conservation Biology.

  11. uG-LilyPond - Floating Plant Pond for Microgravity, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed μG-LilyPond is an autonomous environmentally controlled floating plant cultivation system for use in microgravity. The μG-LilyPond concept expands the...

  12. Solar engineering 1994

    International Nuclear Information System (INIS)

    Klett, D.E.; Hogan, R.E.; Tanaka, Tadayoshi

    1994-01-01

    This volume of 83 papers constitutes the Proceedings of the 1994 International Solar Energy Conference held March 27--30, 1994 in San Francisco, California. The Conference was jointly sponsored by the Solar Energy Division of the American Society of Mechanical Engineers, The Japan Society of Mechanical Engineers and the Japan Solar Energy Society. This is the fourth cooperation between ASME, JSME and JSES in cosponsoring the International Solar Energy Conference. The papers cover a wide range of solar technologies from low temperature solar ponds and desalinization to high temperature concentrators for space applications and central receivers for terrestrial power generation. Other topics covered include solar detoxification of hazardous waste, dish Stirling systems, solar cooling, photovoltaics, building energy analysis and conservation, simulation, and testing and measurement techniques. All papers were indexed separately for the data base

  13. Salt Tolerance

    OpenAIRE

    Xiong, Liming; Zhu, Jian-Kang

    2002-01-01

    Studying salt stress is an important means to the understanding of plant ion homeostasis and osmo-balance. Salt stress research also benefits agriculture because soil salinity significantly limits plant productivity on agricultural lands. Decades of physiological and molecular studies have generated a large body of literature regarding potential salt tolerance determinants. Recent advances in applying molecular genetic analysis and genomics tools in the model plant Arabidopsis thaliana are sh...

  14. Sea salt

    OpenAIRE

    Galvis-Sánchez, Andrea C.; Lopes, João Almeida; Delgadillo, Ivone; Rangel, António O. S. S.

    2013-01-01

    The geographical indication (GI) status links a product with the territory and with the biodiversity involved. Besides, the specific knowledge and cultural practices of a human group that permit transforming a resource into a useful good is protected under a GI designation. Traditional sea salt is a hand-harvested product originating exclusively from salt marshes from specific geographical regions. Once salt is harvested, no washing, artificial drying or addition of anti-caking agents are all...

  15. 100-D Ponds closure plan. Revision 1

    International Nuclear Information System (INIS)

    Petersen, S.W.

    1997-09-01

    The 100-D Ponds is a Treatment, Storage, and Disposal (TSD) unit on the Hanford Facility that received both dangerous and nonregulated waste. This Closure Plan (Rev. 1) for the 100-D Ponds TSD unit consists of a RCRA Part A Dangerous Waste Permit Application (Rev. 3), a RCRA Closure Plan, and supporting information contained in the appendices to the plan. The closure plan consists of eight chapters containing facility description, process information, waste characteristics, and groundwater monitoring data. There are also chapters containing the closure strategy and performance standards. The strategy for the closure of the 100-D Ponds TSD unit is clean closure. Appendices A and B of the closure plan demonstrate that soil and groundwater beneath 100-D Ponds are below cleanup limits. All dangerous wastes or dangerous waste constituents or residues associated with the operation of the ponds have been removed, therefore, human health and the environment are protected. Discharges to the 100-D Ponds, which are located in the 100-DR-1 operable unit, were discontinued in June 1994. Contaminated sediment was removed from the ponds in August 1996. Subsequent sampling and analysis demonstrated that there is no contamination remaining in the ponds, therefore, this closure plan is a demonstration of clean closure

  16. Aquatic studies of Gable Mountain Pond

    International Nuclear Information System (INIS)

    Cushing, C.E.; Watson, D.G.

    1974-12-01

    Studies of the biotic and abiotic components of the Gable Mountain Pond (HAPO cooling water disposal pond) ecosystem were undertaken to determine if there was a potential problem for off-site transfer of radioactivity to man originating with the aquatic food web. Most of the 137 Cs in the pond is associated with the sediments which are probably the main source of 137 Cs for uptake by the biota. Generally, highest concentrations of 137 Cs and other radioisotopes were found in the upper two inches of sediments in the northwest end of the pond and in the deeper areas along the long-axis of the pond. Native goldfish had maximum and average 137 Cs concentrations of about 340 and 170 pCi/g dry wt, respectively. Algae, macrophytes, and detritus comprised the main food items of the goldfish, and the 137 Cs levels in the plants were usually higher than the 137 Cs concentration in the fish. The 137 Cs concentrations of wild experimental ducks restricted to Gable Mountain Pond were approximately the same as resident coots, but significantly higher than transient wild ducks. Neither the goldfish nor the waterfowl inhabiting the pond attained concentrations of 137 Cs exceeding acceptable limits. Sediment, however, could be a source of high concentrations of radioactivity or radioactive contamination concern if the concentration of radiocontaminants increased and/or the pond dries up, and the contaminated sediments become windborne. (U.S.)

  17. Par Pond vegetation status Summer 1995 -- Summary

    International Nuclear Information System (INIS)

    Mackey, H.E. Jr.; Riley, R.S.

    1996-01-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the newly emergent, shoreline aquatic plant communities of Par Pond began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level. These surveys continued in July, September, and late October, 1995. Communities similar to the pre-drawdown, Par Pond aquatic plant communities are becoming re-established. Emergent beds of maidencane, lotus, waterlily, and watershield are extensive and well developed. Cattail occurrence continued to increase during the summer, but large beds common to Par Pond prior to the drawdown have not formed. Estimates from SPOT HRV, remote sensing satellite data indicated that as much as 120 hectares of emergent wetlands vegetation may have been present along the Par Pond shoreline by early October, 1995. To track the continued development of macrophytes in Par Pond, future surveys throughout 1996 and 1997, along with the continued evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned

  18. Organic matter decomposition in simulated aquaculture ponds

    NARCIS (Netherlands)

    Torres Beristain, B.

    2005-01-01

    Different kinds of organic and inorganic compounds (e.g. formulated food, manures, fertilizers) are added to aquaculture ponds to increase fish production. However, a large part of these inputs are not utilized by the fish and are decomposed inside the pond. The microbiological decomposition of the

  19. Pond of Illusion: Interacting through Mixed Reality

    DEFF Research Database (Denmark)

    Nobel-Jørgensen, Morten; Nielsen, Jannik Boll; Larsen, Anders Boesen Lindbo

    2013-01-01

    Pond of Illusion is a mixed reality installation where a virtual space (the pond) is injected between two real spaces. The users are in either of the real spaces, and they can see each other through windows in the virtual space as illustrated in Figure 1(left). The installation attracts people...... to a large display in either of the real spaces by allowing them to feed virtual fish swimming in the pond. Figure 1(middle) shows how a Microsoft Kinect mounted on top of the display is used for detecting throw motions, which triggers virtual breadcrumbs to be thrown into the pond for feeding the nearby...... fish. Of course, the fish may not be available because they are busy eating what people have thrown into the pond from the other side....

  20. Intermediate pond sizes contain the highest density, richness, and diversity of pond-breeding amphibians.

    Directory of Open Access Journals (Sweden)

    Raymond D Semlitsch

    Full Text Available We present data on amphibian density, species richness, and diversity from a 7140-ha area consisting of 200 ponds in the Midwestern U.S. that represents most of the possible lentic aquatic breeding habitats common in this region. Our study includes all possible breeding sites with natural and anthropogenic disturbance processes that can be missing from studies where sampling intensity is low, sample area is small, or partial disturbance gradients are sampled. We tested whether pond area was a significant predictor of density, species richness, and diversity of amphibians and if values peaked at intermediate pond areas. We found that in all cases a quadratic model fit our data significantly better than a linear model. Because small ponds have a high probability of pond drying and large ponds have a high probability of fish colonization and accumulation of invertebrate predators, drying and predation may be two mechanisms driving the peak of density and diversity towards intermediate values of pond size. We also found that not all intermediate sized ponds produced many larvae; in fact, some had low amphibian density, richness, and diversity. Further analyses of the subset of ponds represented in the peak of the area distribution showed that fish, hydroperiod, invertebrate density, and canopy are additional factors that drive density, richness and diversity of ponds up or down, when extremely small or large ponds are eliminated. Our results indicate that fishless ponds at intermediate sizes are more diverse, produce more larvae, and have greater potential to recruit juveniles into adult populations of most species sampled. Further, hylid and chorus frogs are found predictably more often in ephemeral ponds whereas bullfrogs, green frogs, and cricket frogs are found most often in permanent ponds with fish. Our data increase understanding of what factors structure and maintain amphibian diversity across large landscapes.

  1. Profit of solar energy for salting and drying of a brazilian fish Colossoma mitrei Berg, 1895; Utilizacao da energia solar para avaliacao da salga e secagem do pacu, Colossoma mitrei Berg, 1895

    Energy Technology Data Exchange (ETDEWEB)

    Sales, Ronaldo de Oliveira [1Ceara Univ., Fortaleza, CE (Brazil). Centro de Ciencias Agrarias; Beirao, Luiz Henrique [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Ciencias e Tecnologia de Alimentos

    1986-12-01

    This paper studied a simple method for processing dried-salted `pacu` fish. The average weight in relation to total weight was 58,6% and the result came very close to the average of weight of other dried salted fishes, when treated in same way. The main purpose of this process was to reduce the long time expanded by the conventional process, allowing to reduce the humidity of the dried-salted product from 56 to 43,5% in 28 hours only. (author) 20 refs., 3 figs., 8 tabs.

  2. Toxicity of road salt to Nova Scotia amphibians

    International Nuclear Information System (INIS)

    Collins, Sara J.; Russell, Ronald W.

    2009-01-01

    The deposition of chemical pollutants into roadside wetlands from runoff is a current environmental concern. In northern latitudes, a major pollutant in runoff water is salt (NaCl), used as de-icing agents. In this study, 26 roadside ponds were surveyed for amphibian species richness and chloride concentration. Acute toxicity tests (LC 50 ) were performed on five locally common amphibian species using a range of environmentally significant NaCl concentrations. Field surveys indicated that spotted salamanders (Ambystoma maculatum) and wood frogs (Rana sylvatica) did not occupy high chloride ponds. American toads (Bufo americanus) showed no pond preference based on chloride concentration. Acute toxicity tests showed spotted salamanders and wood frogs were most sensitive to chloride, and American toads were the least. Spring peepers (Pseudacris crucifer) and green frogs (Rana clamitans) showed intermediate sensitivities. We concluded that chloride concentrations in ponds due to application of de-icing salts, influenced community structure by excluding salt intolerant species. - Salt toxicity is presented as a mechanism affecting the distribution of amphibians and structure of amphibian communities in roadside wetlands

  3. CO₂ efflux from shrimp ponds in Indonesia.

    Science.gov (United States)

    Sidik, Frida; Lovelock, Catherine E

    2013-01-01

    The conversion of mangrove forest to aquaculture ponds has been increasing in recent decades. One of major concerns of this habitat loss is the release of stored 'blue' carbon from mangrove soils to the atmosphere. In this study, we assessed carbon dioxide (CO₂) efflux from soil in intensive shrimp ponds in Bali, Indonesia. We measured CO₂ efflux from the floors and walls of shrimp ponds. Rates of CO₂ efflux within shrimp ponds were 4.37 kg CO₂ m⁻² y⁻¹ from the walls and 1.60 kg CO₂ m⁻² y⁻¹ from the floors. Combining our findings with published data of aquaculture land use in Indonesia, we estimated that shrimp ponds in this region result in CO₂ emissions to the atmosphere between 5.76 and 13.95 Tg y⁻¹. The results indicate that conversion of mangrove forests to aquaculture ponds contributes to greenhouse gas emissions that are comparable to peat forest conversion to other land uses in Indonesia. Higher magnitudes of CO₂ emission may be released to atmosphere where ponds are constructed in newly cleared mangrove forests. This study indicates the need for incentives that can meet the target of aquaculture industry without expanding the converted mangrove areas, which will lead to increased CO₂ released to atmosphere.

  4. CO₂ efflux from shrimp ponds in Indonesia.

    Directory of Open Access Journals (Sweden)

    Frida Sidik

    Full Text Available The conversion of mangrove forest to aquaculture ponds has been increasing in recent decades. One of major concerns of this habitat loss is the release of stored 'blue' carbon from mangrove soils to the atmosphere. In this study, we assessed carbon dioxide (CO₂ efflux from soil in intensive shrimp ponds in Bali, Indonesia. We measured CO₂ efflux from the floors and walls of shrimp ponds. Rates of CO₂ efflux within shrimp ponds were 4.37 kg CO₂ m⁻² y⁻¹ from the walls and 1.60 kg CO₂ m⁻² y⁻¹ from the floors. Combining our findings with published data of aquaculture land use in Indonesia, we estimated that shrimp ponds in this region result in CO₂ emissions to the atmosphere between 5.76 and 13.95 Tg y⁻¹. The results indicate that conversion of mangrove forests to aquaculture ponds contributes to greenhouse gas emissions that are comparable to peat forest conversion to other land uses in Indonesia. Higher magnitudes of CO₂ emission may be released to atmosphere where ponds are constructed in newly cleared mangrove forests. This study indicates the need for incentives that can meet the target of aquaculture industry without expanding the converted mangrove areas, which will lead to increased CO₂ released to atmosphere.

  5. Waste Stabilization Ponds and Aerated Lagoons Performance in Removal of Wastewater Indicator Microorganisms

    Directory of Open Access Journals (Sweden)

    Seyed ali Ghasemi

    2013-08-01

    Full Text Available In this work, the performance of two treatment plants in the City of Mashhad, one with an aerated lagoons system and the other one with waste stabilization ponds system were evaluated in regard to their efficiency in reduction of pathogenic microorganisms. For this purpose, over a period of one year (with 15-days intervals, samples were taken from the influent and effluent (prior to disinfection unit of the above mentioned treatment plants. The samples then were analyzed for parameters such as temperature, pH, density of total coliforms (TC and fecal coliforms (FC, dissolved oxygen and total suspended solids concentration. The results indicated that the aerated lagoons system was much more efficient in removal of indicator bacteria than the waste stabilization ponds during autumn and winter periods. However during the summer months, the waste stabilization ponds showed a higher efficiency in this regard. In general, the waste stabilization ponds system reduced the density of TC and FC by 0.21-2.15 log10 and 0.20-2.33 log10, respectively. In contrast, the levels of reduction in aerated lagoons system were in the range of 0.29-2.03 log10 for TC and 0.42-2.40 log10 for FC. Results indicated that solar intensity, pH and dissolved oxygen concentration were found to be the most significant parameters that reduced the microorganisms population in waste stabilization ponds, While, in the aerated lagoons system, the dissolved oxygen concentration in aerated basin and solar intensity play the most important role. In general, without receiving an adequate disinfection, the effluent from waste stabilization ponds and aerated lagoons cannot provide the microbiological standards required for irrigation of agricultural crops.

  6. ELECTROKINETIC DENSIFICATION OF COAL FINES IN WASTE PONDS

    Energy Technology Data Exchange (ETDEWEB)

    E. James Davis

    1998-05-01

    The objective of this research is to demonstrate that electrokinetics can be used to remove colloidal coal and mineral particles from coal-washing ponds and lakes without the addition of chemical additives such as salts and polymeric flocculants. In this experimental and analytical study the authors elucidate the transport processes that control the rate of concentrated colloidal particle removal, demonstrate the process on a laboratory scale, and develop the scale-up laws needed to design commercial-scale processes. The authors are also addressing the fundamental problems associated with particle-particle interactions (electrical and hydrodynamic), the effects of particle concentration on the applied electric field, the electrochemical reactions that occur at the electrodes, and the prediction of power requirements.

  7. ANL-W 779 pond seepage test

    International Nuclear Information System (INIS)

    Braun, D.R.

    1992-11-01

    The ANL-W 779 sanitary wastewater treatment ponds are located on the Idaho National Engineering Laboratory (INEL), north of the Argonne National Laboratory -- West (ANL-W) site A seepage test was performed for two Argonne National Laboratory -- West (ANL-W) sanitary wastewater treatment ponds, Facility 779. Seepage rates were measured to determine if the ponds are a wastewater land application facility. The common industry standard for wastewater land application facilities is a field-measured seepage rate of one quarter inch per day or greater

  8. 100-D Ponds groundwater quality assessment

    International Nuclear Information System (INIS)

    Hartman, M.J.

    1996-01-01

    The 100-D Ponds facility is regulated under the Resource Conservation and Recovery Act of 1976. The pH of groundwater in a downgradient well is statistically different than local background, triggering an assessment of groundwater contamination under 40 CFR 265.93. Results of a similar assessment, conducted in 1993, show that the elevated pH is caused by the presence of alkaline ash sediments beneath the ponds, which are not part of the RCRA unit. The 100-D Ponds should remain in indicator evaluation monitoring

  9. WWER-type NPP spray ponds screen

    International Nuclear Information System (INIS)

    Nikolova, M.; Jordanov, M.; Denev, J.; Markov, D.

    2003-01-01

    The objective of this study is to develop a protection screen of WWER-type NPP spray ponds. The screen design is to ensure reduction of the water droplets blown by the wind and, if possible, their return back to the spray ponds. The cooling capacity of the ponds is not to be changed below the design level for safety reasons. Computational fluid dynamics analysis is used to assess the influence of each design variant on the behavior of the water droplets distribution. Two variants are presented here. The one with plants is found not feasible. The second variant, with steel screen and terrain profile modification is selected for implementation. (author)

  10. An automatic energy-saving and thermal monitoring/controlling system for a pond

    Directory of Open Access Journals (Sweden)

    Cheng Ching-Chien

    2017-01-01

    Full Text Available Because of low temperatures and oxygen in cold water, fish will die when cold currents arrive. This will cause tremendous loss of money. In order reduce the cooling of the pond, an automatic thermal detecting and cold-roofing system using a wind-proofing device, heaters, and thermal detectors is proposed. To reduce heat loss due to thermal convection above the pond surface, a motor-driven wind-proofing device automatically controlled by a PLC controller is adopted. Here, the wind-proofing device, thermal detectors, and heating system are connected to the PLC controller. The PLC will also be connected to the PC interface. The temperature thresholds used to trigger the heater and the wind proofing device can be set at the PC interface. Two options for manipulating the heating and the automatic heating can be selected. The related wind-proofing area and the number of heaters will be determined according to the current temperature. Moreover, the PLC can be wirelessly connected to the server PC in the control room. The pond keeper can monitor everything online and control the pond water's temperature. With this, the problem of fish dying in a cold wave can be solved. Consequently, to reduce the electrical exhaust when heating up the pond water, green energy, solar energy and wind energy, is used.

  11. Percolation blockage: A process that enables melt pond formation on first year Arctic sea ice

    Science.gov (United States)

    Polashenski, Chris; Golden, Kenneth M.; Perovich, Donald K.; Skyllingstad, Eric; Arnsten, Alexandra; Stwertka, Carolyn; Wright, Nicholas

    2017-01-01

    Melt pond formation atop Arctic sea ice is a primary control of shortwave energy balance in the Arctic Ocean. During late spring and summer, the ponds determine sea ice albedo and how much solar radiation is transmitted into the upper ocean through the sea ice. The initial formation of ponds requires that melt water be retained above sea level on the ice surface. Both theory and observations, however, show that first year sea ice is so highly porous prior to the formation of melt ponds that multiday retention of water above hydraulic equilibrium should not be possible. Here we present results of percolation experiments that identify and directly demonstrate a mechanism allowing melt pond formation. The infiltration of fresh water into the pore structure of sea ice is responsible for blocking percolation pathways with ice, sealing the ice against water percolation, and allowing water to pool above sea level. We demonstrate that this mechanism is dependent on fresh water availability, known to be predominantly from snowmelt, and ice temperature at melt onset. We argue that the blockage process has the potential to exert significant control over interannual variability in ice albedo. Finally, we suggest that incorporating the mechanism into models would enhance their physical realism. Full treatment would be complex. We provide a simple temperature threshold-based scheme that may be used to incorporate percolation blockage behavior into existing model frameworks.

  12. Identification and characterization of bacteria in a selenium-contaminated hypersaline evaporation pond.

    Science.gov (United States)

    de Souza, M P; Amini, A; Dojka, M A; Pickering, I J; Dawson, S C; Pace, N R; Terry , N

    2001-09-01

    Solar evaporation ponds are commonly used to reduce the volume of seleniferous agricultural drainage water in the San Joaquin Valley, Calif. These hypersaline ponds pose an environmental health hazard because they are heavily contaminated with selenium (Se), mainly in the form of selenate. Se in the ponds may be removed by microbial Se volatilization, a bioremediation process whereby toxic, bioavailable selenate is converted to relatively nontoxic dimethylselenide gas. In order to identify microbes that may be used for Se bioremediation, a 16S ribosomal DNA phylogenetic analysis of an aerobic hypersaline pond in the San Joaquin Valley showed that a previously unaffiliated group of uncultured bacteria (belonging to the order Cytophagales) was dominant, followed by a group of cultured gamma-Proteobacteria which was closely related to Halomonas species. Se K-edge X-ray absorption spectroscopy of selenate-treated bacterial isolates showed that they accumulated a mixture of predominantly selenate and a selenomethionine-like species, consistent with the idea that selenate was assimilated via the S assimilation pathway. One of these bacterial isolates (Halomonas-like strain MPD-51) was the best candidate for the bioremediation of hypersaline evaporation ponds contaminated with high Se concentrations because it tolerated 2 M selenate and 32.5% NaCl, grew rapidly in media containing selenate, and accumulated and volatilized Se at high rates (1.65 microg of Se g of protein(-1) x h(-1)), compared to other cultured bacterial isolates.

  13. Modeling Nitrogen Decrease in Water Lettuce Ponds from Waste Stabilization Ponds

    Science.gov (United States)

    Putri, Gitta Agnes; Sunarsih

    2018-02-01

    This paper presents about the dynamic modeling of the Water Lettuce ponds as a form of improvement from the Water Hyacinth ponds. The purpose of this paper is to predict nitrogen decrease and nitrogen transformation in Water Lettuce ponds integrated with Waste Stabilization Ponds. The model consists of 4 mass balances, namely Dissolved Organic Nitrogen (DON), Particulate Organic Nitrogen (PON), ammonium (NH4+), Nitrate and Nitrite (NOx). The process of nitrogen transformation which considered in a Water Lettuce ponds, namely hydrolysis, mineralization, nitrification, denitrification, plant and bacterial uptake processes. Numerical simulations are performed by giving the values of parameters and the initial values of nitrogen compounds based on a review of previous studies. Numerical results show that the rate of change in the concentration of nitrogen compounds in the integration ponds of waste stabilization and water lettuce decreases and reaches stable at different times.

  14. Salt cookbook

    CERN Document Server

    Saha, Anirban

    2015-01-01

    If you are a professional associated with system and infrastructure management, looking at automated infrastructure and deployments, then this book is for you. No prior experience of Salt is required.

  15. Musculoskeletal disorder survey for pond workers

    Science.gov (United States)

    Maryani, A.; Partiwi, S. G.; Dewi, H. N. F.

    2018-04-01

    Mucsuloskeletal disorder will affect worker performance and become serious injury when ignored, so that workers cannot work normally. Therefore, an effective strategy plan is needed to reduce the risk of musculoskeletal disorder. A pond worker is profession with high risk of physical complain. Four main activities are ponds preparation, seed distribution, pond maintenance, and harvesting. The methods employed in this current musculoskeletal disorder survey are questionnaire and interview. The result from 73 questionnaires shown that most of pond workers were working for 7 days a week. Prevalence physical complain are on neck, shoulders, upper back, lower back, and knees. The level of perceived complaint is moderate pain. However, most of them do not contact therapists or physicians. Therefore it is necessary to improve the working methods to be able to reduce physical complains due to musculoskeletal disorder.

  16. Investigation of the source of residual phthalate in sundried salt.

    Science.gov (United States)

    Kim, Jin Hyo; Lee, Jin Hwan; Kim, So-Young

    2014-03-01

    Phthalate contamination in sundried salt has recently garnered interest in Korea. Phthalate concentrations were investigated in Korean sundried salts, source waters, and aqueous extracts from polyvinyl chloride materials used in salt ponds. Preliminary screening results for phthalates in Korean sundried salts revealed that only di(2-ethylhexyl)phthalate (DEHP) was over the limit of detection, with an 8.6% detection rate, and the concentration ranged from below the limit of detection to 0.189 mg/kg. The tolerable daily intake contribution ratio of the salt was calculated to be only 0.001%. Residual phthalates were below 0.026 mg/liter in source water, and the aqueous extracted di-n-butylphthalate, benzylbutylphthalate, and DEHP, which are considered endocrine disruptors, were below 0.029 mg/kg as derived from the polyvinyl chloride materials in salt ponds. The transfer ratios of the six phthalates from seawater to sundried salts were investigated; transfer ratio was correlated with vapor pressure (r(2) = 0.9875). Thus, di-n-butylphthalate, benzylbutylphthalate, DEHP, and di-n-octylphthalate can be considered highly likely residual pollutants in some consumer salts.

  17. Pond and Irrigation Model (PIM): a tool for simultaneously evaluating pond water availability and crop irrigation demand

    Science.gov (United States)

    Ying Ouyang; Gary Feng; Theodor D. Leininger; John Read; Johnie N. Jenkins

    2018-01-01

    Agricultural ponds are an important alternative source of water for crop irrigation to conserve surface and ground water resources. In recent years more such ponds have been constructed in Mississippi and around the world. There is currently, however, a lack of a tool to simultaneously estimate crop irrigation demand and pond water availability. In this study, a Pond-...

  18. Wintertime Emissions from Produced Water Ponds

    Science.gov (United States)

    Evans, J.; Lyman, S.; Mansfield, M. L.

    2013-12-01

    Every year oil and gas drilling in the U.S. generates billions of barrels of produced water (water brought to the surface during oil or gas production). Efficiently disposing of produced water presents a constant financial challenge for producers. The most noticeable disposal method in eastern Utah's Uintah Basin is the use of evaporation ponds. There are 427 acres of produced water ponds in the Uintah Basin, and these were used to evaporate more than 5 million barrels of produced water in 2012, 6% of all produced water in the Basin. Ozone concentrations exceeding EPA standards have been observed in the Uintah Basin during winter inversion conditions, with daily maximum 8 hour average concentrations at some research sites exceeding 150 parts per billion. Produced water contains ozone-forming volatile organic compounds (VOC) which escape into the atmosphere as the water is evaporated, potentially contributing to air quality problems. No peer-reviewed study of VOC emissions from produced water ponds has been reported, and filling this gap is essential for the development of accurate emissions inventories for the Uintah Basin and other air sheds with oil and gas production. Methane, carbon dioxide, and VOC emissions were measured at three separate pond facilities in the Uintah Basin in February and March of 2013 using a dynamic flux chamber. Pond emissions vary with meteorological conditions, so measurements of VOC emissions were collected during winter to obtain data relevant to periods of high ozone production. Much of the pond area at evaporation facilities was frozen during the study period, but areas that actively received water from trucks remained unfrozen. These areas accounted for 99.2% of total emissions but only 9.5% of the total pond area on average. Ice and snow on frozen ponds served as a cap, prohibiting VOC from being emitted into the atmosphere. Emissions of benzene, toluene, and other aromatic VOCs averaged over 150 mg m-2 h-1 from unfrozen pond

  19. UHS, Ultimate Heat Sink Cooling Pond Analysis

    International Nuclear Information System (INIS)

    Codell, R.; Nuttle, W.K.

    1998-01-01

    1 - Description of program or function: Three programs model performance of an ultimate heat sink cooling pond. National Weather Service data is read and analyzed to predict periods of lowest cooling performance and highest evaporative loss. The data is compared to local site data for significant differences. Then the maximum pond temperature is predicted. Five programs model performance of an ultimate heat sink spray pond. The cooling performance, evaporative water loss, and drift water loss as a function of wind speed are estimated for a spray field. These estimates are used in conjunction with National Weather Service data to predict periods of lowest cooling performance and highest evaporative loss. This data is compared to local site data for significant differences. Then the maximum pond temperature is predicted. 2 - Method of solution: The transfer of heat and water vapor is modeled using an equilibrium temperature procedure for an UHS cooling pond. The UHS spray pond model considers heat, mass, and momentum transfer from a single water drop with the surrounding air, and modification of the surrounding air resulting from the heat, mass, and momentum transfer from many drops in different parts of a spray field. 3 - Restrictions on the complexity of the problem: The program SPRCO uses RANF, a uniform random number generator which is an intrinsic function on the CDC. All programs except COMET use the NAMELIST statement, which is non standard. Otherwise these programs conform to the ANSI Fortran 77 standard. The meteorological data scanning procedure requires tens of years of recorded data to be effective. The models and methods, provided as useful tool for UHS analyses of cooling ponds and spray ponds, are intended as guidelines only. Use of these methods does not automatically assure NRC approval, nor are they required procedures for nuclear-power-plant licensing

  20. Molten salt power towers operating at 600–650 °C: Salt selection and cost benefits

    Energy Technology Data Exchange (ETDEWEB)

    Turchi, Craig S. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Vidal, Judith [National Renewable Energy Lab. (NREL), Golden, CO (United States); Bauer, Matthew

    2018-04-01

    This analysis examines the potential benefit of adopting the supercritical carbon dioxide (sCO2) Brayton cycle at 600-650 degrees C compared to the current state-of-the-art power tower operating a steam-Rankine cycle with solar salt at approximately 574 degrees C. The analysis compares a molten-salt power tower configuration using direct storage of solar salt (60:40 wt% sodium nitrate: potassium nitrate) or single-component nitrate salts at 600 degrees C or alternative carbonate- or chloride-based salts at 650 degrees C.

  1. Modelling radiative transfer through ponded first-year Arctic sea ice with a plane-parallel model

    Science.gov (United States)

    Taskjelle, Torbjørn; Hudson, Stephen R.; Granskog, Mats A.; Hamre, Børge

    2017-09-01

    Under-ice irradiance measurements were done on ponded first-year pack ice along three transects during the ICE12 expedition north of Svalbard. Bulk transmittances (400-900 nm) were found to be on average 0.15-0.20 under bare ice, and 0.39-0.46 under ponded ice. Radiative transfer modelling was done with a plane-parallel model. While simulated transmittances deviate significantly from measured transmittances close to the edge of ponds, spatially averaged bulk transmittances agree well. That is, transect-average bulk transmittances, calculated using typical simulated transmittances for ponded and bare ice weighted by the fractional coverage of the two surface types, are in good agreement with the measured values. Radiative heating rates calculated from model output indicates that about 20 % of the incident solar energy is absorbed in bare ice, and 50 % in ponded ice (35 % in pond itself, 15 % in the underlying ice). This large difference is due to the highly scattering surface scattering layer (SSL) increasing the albedo of the bare ice.

  2. Modelling radiative transfer through ponded first-year Arctic sea ice with a plane-parallel model

    Directory of Open Access Journals (Sweden)

    T. Taskjelle

    2017-09-01

    Full Text Available Under-ice irradiance measurements were done on ponded first-year pack ice along three transects during the ICE12 expedition north of Svalbard. Bulk transmittances (400–900 nm were found to be on average 0.15–0.20 under bare ice, and 0.39–0.46 under ponded ice. Radiative transfer modelling was done with a plane-parallel model. While simulated transmittances deviate significantly from measured transmittances close to the edge of ponds, spatially averaged bulk transmittances agree well. That is, transect-average bulk transmittances, calculated using typical simulated transmittances for ponded and bare ice weighted by the fractional coverage of the two surface types, are in good agreement with the measured values. Radiative heating rates calculated from model output indicates that about 20 % of the incident solar energy is absorbed in bare ice, and 50 % in ponded ice (35 % in pond itself, 15 % in the underlying ice. This large difference is due to the highly scattering surface scattering layer (SSL increasing the albedo of the bare ice.

  3. Models and observations of Arctic melt ponds

    Science.gov (United States)

    Golden, K. M.

    2016-12-01

    During the Arctic melt season, the sea ice surface undergoes a striking transformation from vast expanses of snow covered ice to complex mosaics of ice and melt ponds. Sea ice albedo, a key parameter in climate modeling, is largely determined by the complex evolution of melt pond configurations. In fact, ice-albedo feedback has played a significant role in the recent declines of the summer Arctic sea ice pack. However, understanding melt pond evolution remains a challenge to improving climate projections. It has been found that as the ponds grow and coalesce, the fractal dimension of their boundaries undergoes a transition from 1 to about 2, around a critical length scale of 100 square meters in area. As the ponds evolve they take complex, self-similar shapes with boundaries resembling space-filling curves. I will outline how mathematical models of composite materials and statistical physics, such as percolation and Ising models, are being used to describe this evolution and predict key geometrical parameters that agree very closely with observations.

  4. Bath Salts

    Science.gov (United States)

    ... deaths and been blamed for a handful of suicides and murders. Two of the chemicals in bath salts (mephedrone and MDPV) are Schedule I class drugs. That means they have a high potential for abuse and no accepted medical use . People who are ...

  5. Accumulation of Pollutants in Highway Detention Ponds

    DEFF Research Database (Denmark)

    Bentzen, Thomas Ruby

    single rain event. From the hindcast results it is possible to calculate mean water and pollutant loads. This method is commonly used in urban drainage systems for capacity analysis or for prediction of CSO's. The challenge is to develop a simplified and still accurate description of flow and transport......This PhD study deals with issues related to water and pollutant transport from highway surfaces caused by rain. It is essential in the study to apply methods and models in which improvements in relation to removal of pollutants can be identified and to be able to predict the yearly discharges....... Measurements of water and pollutant transport are carried out in different highway systems. A geometrically well-defined test pond is established, wherein the deposition of particulate matter can be measured. The result from the test pond is transferred to real detention ponds in which the three...

  6. Fate of Pyrethroids in Farmland Ponds

    DEFF Research Database (Denmark)

    Mogensen, B. B.; Sørensen, P. B.; Stuer-Lauridsen, F.

    Pyrethroids constitute a group of widely used insecticides, which are toxic to aquatic organisms. This report presents the results from a 2-year study of the fate of pyrethroids in ponds, i.e. their distribution in the water column, the sediment and the surface microlayer respectively. The measur......Pyrethroids constitute a group of widely used insecticides, which are toxic to aquatic organisms. This report presents the results from a 2-year study of the fate of pyrethroids in ponds, i.e. their distribution in the water column, the sediment and the surface microlayer respectively...

  7. Pond dyes are Culex mosquito oviposition attractants

    Directory of Open Access Journals (Sweden)

    Natali Ortiz Perea

    2017-05-01

    Full Text Available Background British mosquito population distribution, abundance, species composition and potential for mosquito disease transmission are intimately linked to the physical environment. The presence of ponds and water storage can significantly increase the density of particular mosquito species in the garden. Culex pipiens is the mosquito most commonly found in UK gardens and a potential vector of West Nile Virus WNV, although the current risk of transmission is low. However any factors that significantly change the distribution and population of C. pipiens are likely to impact subsequent risk of disease transmission. Pond dyes are used to control algal growth and improve aesthetics of still water reflecting surrounding planting. However, it is well documented that females of some species of mosquito prefer to lay eggs in dark water and/or containers of different colours and we predict that dyed ponds will be attractive to Culex mosquitoes. Methods Black pond dye was used in oviposition choice tests using wild-caught gravid C. pipiens. Larvae from wild-caught C. pipiens were also reared in the pond dye to determine whether it had any impact on survival. An emergence trap caught any adults that emerged from the water. Water butts (80 L were positioned around university glasshouses and woodland and treated with black pond dye or left undyed. Weekly sampling over a six month period through summer and autumn was performed to quantified numbers of larvae and pupae in each treatment and habitat. Results Gravid female Culex mosquitoes preferred to lay eggs in dyed water. This was highly significant in tests conducted under laboratory conditions and in a semi-field choice test. Despite this, survivorship in black dyed water was significantly reduced compared to undyed water. Seasonal analysis of wild larval and pupal numbers in two habitats with and without dye showed no impact of dye but a significant impact of season and habitat. Mosquitoes were more

  8. Solar Thermal Utilization: Past, Present and Future

    Science.gov (United States)

    2010-09-01

    SO•C NON-FOCUSSING FLAT PLATE / (FPC) 100- 150•C For low temperature 50- 200•C COMPOUND applications PARABOLIC EVACUATED CONCENTRATOR ~ (ETC...2030 Ø 200GW BY 2050 Ø 20 MILLION SQ.METER SOLAR THERMAL COLLECTORS (20GW power) Ø 20 MILLION SOLAR LIGHTS LAUNCHING OF SOLAR INDIA SOLAR THERMAL...Temperature (20oC- 80oC) NALSUN ApplicationsThermal Conversion range SOLAR ENERGY COLLECTORS 40- GO•C UNGLAZED COLLECTORS 60- 90•C SOLAR POND 60

  9. Assessment of groundwater pollution from the oxidation ponds in tenth of Ramadan city, using isotopic techniques and hydrogeological modelling

    International Nuclear Information System (INIS)

    Abd El-Samie, S.G.; Sadek, M.A.; Mahmoud, N.S.

    2002-01-01

    The tenth of ramadan city is an intensive industrial settement on the peripheries of cairo. All types of wastewater from industrial and domestic practices are discharged into three unlined oxidation ponds to eliminate pollutants. The present srudy has been conduted to assess the extent of seepage to groundwater from the ponds and how efficient they are for pollution reduction. The chemical composition is more developed in the groundwater of the miocene aquifer due to the less active recharge and the dominance of readily dissolved salts that interact with the inflow. The seepage from ismailia canal and the excess irrigation from agricultural lands and the infiltration from the oxidation ponds as well as the upleaked water represent the main sources of recharge in the quaternary aquifer. The chemical and isotopic composition of the water in the oxidation ponds is controlled by the nature of the drained water and the geochemical processes affecting the solute content. The isotopic enrichment differs for the three ponds being related to the evaporation intensity in each

  10. Developing Ecological Models on Carbon and Nitrogen in Secondary Facultative Ponds

    Directory of Open Access Journals (Sweden)

    Aponte-Reyes Alexander

    2014-07-01

    Full Text Available Ecological models formulated for TOC, CO2, NH4+, NO3- and NTK, based in literature reviewed and field work were obtained monitoring three facultative secondary stabilization ponds, FSSP, pilots: conventional pond, CP, baffled pond, BP, and baffled-meshed pond, BMP. Models were sensitive to flow inlet, solar radiation, pH and oxygen content; the sensitive parameters in Carbon Model were KCOT Ba, umax Ba, umax Al, K1OX, VAl, R1DCH4, YBh. The sensitive parameters in the Nitrogen model were KCOT Ba, umax Ba, umax Al, VAl, KOPH, KOPA, r4An. The test t–paired showed a good simulating of Carbon model refers to TOC in FSSP; on the other side, the Nitrogen model showed a good simulating of NH4+. Different topological models modify ecosystem ecology forcing different transformation pathways of Nitrogen; equal transformations of the Carbon BMP topology could be achieved using lower volumes, however, a calibration for a new model would be required. Carbon and Nitrogen models developed could be coupled to hydrodynamics models for better modeling of FSSP.

  11. Patterns of microbial diversity along a salinity gradient in the Guerrero Negro solar saltern, Baja CA Sur, Mexico

    Directory of Open Access Journals (Sweden)

    Jesse G Dillon

    2013-12-01

    Full Text Available The goal of this study was to use environmental sequencing of 16S rRNA and bop genes to compare the diversity of planktonic bacteria and archaea across ponds with increasing salinity in the Exportadora de Sal (ESSA evaporative saltern in Guerrero Negro, Baja CA S., Mexico. We hypothesized that diverse communities of heterotrophic bacteria and archaea would be found in the ESSA ponds, but that bacterial diversity would decrease relative to archaea at the highest salinities. Archaeal 16S rRNA diversity was higher in Ponds 11 and 12 (370 & 380 g l-1 total salts respectively compared to Pond 9 (180 g l-1 total salts. Both Pond 11 and 12 communities had high representation (47 and 45% of clones respectively by Haloquadratum walsbyi-like (99% similarity lineages. The archaeal community in Pond 9 was dominated (79% by a single uncultured phylotype with 99% similarity to sequences recovered from the Sfax saltern in Tunisia. This pattern was mirrored in bop gene diversity with greater numbers of highly supported phylotypes including many Haloquadratum-like sequences from the two highest salinity ponds. In Pond 9, most bop sequences, were not closely related to sequences in databases. Bacterial 16S rRNA diversity was higher than archaeal in both Pond 9 and Pond 12 samples, but not Pond 11, where a non-Salinibacter lineage within the Bacteroidetes >98% similar to environmental clones recovered from Lake Tuz in Turkey and a saltern in Chula Vista, CA was most abundant (69% of community. This OTU was also the most abundant in Pond 12, but only represented 14% of clones in the more diverse pond. The most abundant OTU in Pond 9 (33% of community was 99% similar to an uncultured gammaproteobacterial clone from the Salton Sea. Results suggest that the communities of saltern bacteria and archaea vary even in ponds with similar salinity and further investigation into the ecology of diverse, uncultured halophile communities is warranted.

  12. Sea Ice Melt Pond Data from the Canadian Arctic

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains observations of albedo, depth, and physical characteristics of melt ponds on sea ice, taken during the summer of 1994. The melt ponds studied...

  13. Valuing Multiple Benefits, and the Public Perception of SUDS Ponds

    Directory of Open Access Journals (Sweden)

    Joy Jarvie

    2017-02-01

    Full Text Available Understanding how the public perceive and value ponds is fundamental to appreciate the synergy between Sustainable urban Drainage (SUDS ponds and the multiple benefits they provide. This paper investigates this, through the application of a structured postal and online survey, for a case study area of Edinburgh, in the UK. It compares man-made ponds (including SUDS, and ponds with natural origins. The results from Whole Life Cost show that the benefits (based on Contingent Valuation exceed the CAPEX and OPEX costs for three of five artificial ponds studied. Benefits from natural (reference ponds exceed the replacement costs for a pond with the same surface area/catchment. This paper highlights the importance of monetising the multiple benefits from ponds.

  14. EVALUACIÓN DE ALTERNATIVAS PARA CLIMATIZACIÓN DE ESTANQUES CON ENERGÍA SOLAR PARA CULTIVO DE TILAPIA ROJA (Oreochromis sp), LOCALIZADOS EN LA ZONA FRÍA DEL VALLE DEL CAUCA, COLOMBIA EVALUATION OF ALTERNATIVES FOR AIR CONDITIONING OF PONDS WITH SOLAR ENERGY FOR CULTIVATION OF RED TILAPIA (Oreochromis sp), LOCATED IN THE COLD AREA OF THE CAUCA VALLEY, COLOMBIA

    OpenAIRE

    Francisco Javier Borja Gallardo; Luis Octavio González Salcedo; Victoria Eugenia Quintero de Vallejo

    2006-01-01

    La investigación fue desarrollada para que la tilapia roja (Oreochromis sp), especie de pez mÁs producida en Colombia, pueda ser explotada en lugares donde las condiciones óptimas para su normal desarrollo no son las adecuadas, como son las regiones altas con temperaturas por debajo de los 24 °C, aplicando metodologías relacionadas con el aprovechamiento de la energía solar. Las técnicas evaluadas fueron: climatización por medio de colectores solares, climatización por medio de manta térmica,...

  15. 76 FR 78021 - Notice of Availability of the Record of Decision for the Rice Solar Energy, LLC, Rice Solar...

    Science.gov (United States)

    2011-12-15

    ... LVRWB10B3780] Notice of Availability of the Record of Decision for the Rice Solar Energy, LLC, Rice Solar... Solar Energy, LLC, a subsidiary of SolarReserve, LLC plans to construct a 150 megawatt (MW) solar... allows solar energy to be captured throughout the day and retained in a molten salt heat transfer fluid...

  16. Heavy metal composition in stormwater and retention in ponds dependent on pond age, design and catchment type

    DEFF Research Database (Denmark)

    Egemose, Sara; Sønderup, Melanie J.; Grudinina, Anna

    2015-01-01

    Heavy metals have toxic effects on flora and fauna in the aquatic environments and are of great concern in stormwater. Heavy metal runoff was studied in 37 stormwater ponds in Denmark with varying heavy metal load, catchment type and pond design. The studied metals were Cu, Cr, Cd, Pb, Ni and Zn...... difficult to retain. The removal efficiency in the ponds varied considerably, with the highest retention of Pb, Ni and Zn due to higher particulate fraction. The retention increased with increased pond volume-to-reduced catchment area ratio. In addition, the pond age affected the efficiency; whereas ponds...... less than 1-2 years efficiently removed all metals, 30-40-year-old ponds only removed Pb, Ni and Zn, but steeply decreasing over the years. Physical parameters such as pond size, age and sedimentation patterns were found to play a more significant role in the removal compared with chemical parameters...

  17. EVALUACIÓN DE ALTERNATIVAS PARA CLIMATIZACIÓN DE ESTANQUES CON ENERGÍA SOLAR PARA CULTIVO DE TILAPIA ROJA (Oreochromis sp, LOCALIZADOS EN LA ZONA FRÍA DEL VALLE DEL CAUCA, COLOMBIA EVALUATION OF ALTERNATIVES FOR AIR CONDITIONING OF PONDS WITH SOLAR ENERGY FOR CULTIVATION OF RED TILAPIA (Oreochromis sp, LOCATED IN THE COLD AREA OF THE CAUCA VALLEY, COLOMBIA

    Directory of Open Access Journals (Sweden)

    Francisco Javier Borja Gallardo

    2006-06-01

    Full Text Available La investigación fue desarrollada para que la tilapia roja (Oreochromis sp, especie de pez mÁs producida en Colombia, pueda ser explotada en lugares donde las condiciones óptimas para su normal desarrollo no son las adecuadas, como son las regiones altas con temperaturas por debajo de los 24 °C, aplicando metodologías relacionadas con el aprovechamiento de la energía solar. Las técnicas evaluadas fueron: climatización por medio de colectores solares, climatización por medio de manta térmica, climatización por medio de mangueras térmicas y climatización por medio de resistencias eléctricas. Se analizaron factores como funcionalidad, mantenimiento, limitaciones organizativas, espaciales, y costos.The research was developed so that the red tilapia (Oreochromis sp, fish species that more taken place in Colombia can be exploited in regions where the good conditions for its normal development are not the appropriate ones as in the high regions with temperatures below the 24 °C, applying methodologies related with the use of the solar energy. The evaluated methodologies were: air conditioning by means of solar collectors, air conditioning by means of thermal blanket, air conditioning by means of thermal hoses and air conditioning by means of electric resistances. Factors like functionality, maintenance, organizational and space limitations, and costs were analized.

  18. Characterisation of potential aquaculture pond effluents, and ...

    African Journals Online (AJOL)

    Conventional treatment of effluents from these small-scale, low-volume operations, which discharge relatively dilute effluents infrequently, might not be cost-effective. Keywords: aquaculture–environment interaction, earthen ponds, effluent characterisation, K-means clustering, t ilapia, water quality. African Journal of Aquatic ...

  19. Aquatic Habitats: Exploring Desktop Ponds. Teacher's Guide.

    Science.gov (United States)

    Barrett, Katharine; Willard, Carolyn

    This book, for grades 2-6, is designed to provide students with a highly motivating and unique opportunity to investigate an aquatic habitat. Students set up, observe, study, and reflect upon their own "desktop ponds." Accessible plants and small animals used in these activities include Elodea, Tubifex worms, snails, mosquito larvae, and fish.…

  20. Interconnected ponds operation for flood hazard distribution

    Science.gov (United States)

    Putra, S. S.; Ridwan, B. W.

    2016-05-01

    The climatic anomaly, which comes with extreme rainfall, will increase the flood hazard in an area within a short period of time. The river capacity in discharging the flood is not continuous along the river stretch and sensitive to the flood peak. This paper contains the alternatives on how to locate the flood retention pond that are physically feasible to reduce the flood peak. The flood ponds were designed based on flood curve number criteria (TR-55, USDA) with the aim of rapid flood peak capturing and gradual flood retuning back to the river. As a case study, the hydrologic condition of upper Ciliwung river basin with several presumed flood pond locations was conceptually designed. A fundamental tank model that reproducing the operation of interconnected ponds was elaborated to achieve the designed flood discharge that will flows to the downstream area. The flood hazard distribution status, as the model performance criteria, will be computed within Ciliwung river reach in Manggarai Sluice Gate spot. The predicted hazard reduction with the operation of the interconnected retention area result had been bench marked with the normal flow condition.

  1. Scenario evaluation of open pond microalgae production

    NARCIS (Netherlands)

    Slegers, P.M.; Lösing, M.B.; Wijffels, R.H.; Straten, van G.; Boxtel, van A.J.B.

    2013-01-01

    To evaluate microalgae production in large scale open ponds under different climatologic conditions, a model-based framework is used to study the effect of light conditions, water temperature and reactor design on trends in algae productivity. Scenario analyses have been done for two algae species

  2. Thermal performances of molten salt steam generator

    International Nuclear Information System (INIS)

    Yuan, Yibo; He, Canming; Lu, Jianfeng; Ding, Jing

    2016-01-01

    Highlights: • Thermal performances of molten salt steam generator were experimentally studied. • Overall heat transfer coefficient reached maximum with optimal molten salt flow rate. • Energy efficiency first rose and then decreased with salt flow rate and temperature. • Optimal molten salt flow rate and temperature existed for good thermal performance. • High inlet water temperature benefited steam generating rate and energy efficiency. - Abstract: Molten salt steam generator is the key technology for thermal energy conversion from high temperature molten salt to steam, and it is used in solar thermal power station and molten salt reactor. A shell and tube type molten salt steam generator was set up, and its thermal performance and heat transfer mechanism were studied. As a coupling heat transfer process, molten salt steam generation is mainly affected by molten salt convective heat transfer and boiling heat transfer, while its energy efficiency is also affected by the heat loss. As molten salt temperature increased, the energy efficiency first rose with the increase of heat flow absorbed by water/steam, and then slightly decreased for large heat loss as the absorbed heat flow still rising. At very high molten salt temperature, the absorbed heat flow decreased as boiling heat transfer coefficient dropping, and then the energy efficiency quickly dropped. As the inlet water temperature increased, the boiling region in the steam generator remarkably expanded, and then the steam generation rate and energy efficiency both rose with the overall heat transfer coefficient increasing. As the molten salt flow rate increased, the wall temperature rose and the boiling heat transfer coefficient first increased and then decreased according to the boiling curve, so the overall heat transfer coefficient first increased and then decreased, and then the steam generation rate and energy efficiency of steam generator both had maxima.

  3. Microbial activities and communities in oil sands tailings ponds

    Energy Technology Data Exchange (ETDEWEB)

    Gieg, Lisa; Ramos, Esther; Clothier, Lindsay; Bordenave, Sylvain; Lin, Shiping; Voordouw, Gerrit; Dong, Xiaoli; Sensen, Christoph [University of Calgary (Canada)

    2011-07-01

    This paper discusses how the microbial communities and their activity play a vital role in tailings ponds. The ponds contain microorganisms along with metals, hydrocarbon diluent, naphthenic acid and others. The ponds play an important role in mining operations because they store bitumen extraction waste and also allow water to be re-used in the bitumen extraction process. Pond management presents a few challenges that include, among others, gas emissions and the presence of toxic and corrosive acids. Microbial activities and communities help in managing these ponds. Microbial activity measurement in active and inactive ponds is described and analyzed and the results are presented. The conditions for reducing sulfate, nitrate and iron are also presented. From the results it can be concluded that naphthenic acids can potentially serve as substrates for anaerobic populations in tailings ponds.

  4. Heavy metals, PAHs and toxicity in stormwater wet detention ponds

    DEFF Research Database (Denmark)

    Wium-Andersen, Tove; Nielsen, Asbjørn Haaning; Hvitved-Jacobsen, Thorkild

    2011-01-01

    Concentrations of 6 different heavy metals and total Polycyclic Aromatic Hydrocarbons (PAH) were determined in stormwater runoff and in the pond water of two Danish wet detention ponds. The pond water samples were analyzed for toxic effects, using the algae Selenastrum capricornutum as a test...... organism. Stormwater and pond water from a catchment with light industry showed high levels of heavy metals, especially zinc and copper. The pond water showed high toxic effects and copper were found to be the main toxicant. Additionally, a large part of the copper was suspected to be complex bound......, reducing the potential toxicity of the metal. Another catchment (residential) produced stormwater and pond water with moderate concentration of heavy metals. The pond water occasionally showed toxic effects but no correlation between heavy metals and toxicity was identified. PAHs concentrations were...

  5. The complex challenge of repairing the gantry steelwork on the first generation magnox storage pond at Sellafield: Legacy Waste Storage, First Generation Magnox Storage Pond - 59133

    International Nuclear Information System (INIS)

    Richardson, Ian E.

    2012-01-01

    This paper puts into context the challenges that were faced when repairing the Gantry Steelwork of the First Generation Magnox Storage Pond (FGMSP). The First Generation Magnox Fuel Storage Pond (FGMSP) provided fuel storage and de-canning capability from the early 1960's until 1986. A significant programme of work has been underway since the completion of operational activities to support the programmes strategic intent of retrieving and storing all legacy wastes, and remediating the structure of the plant to support decommissioning activities. A key enabler to the retrievals programme is the Pond Skip Handler Machine (SHM), removed from service in 2002 following the discovery of significant signs of corrosion and distress, an inevitable consequence of being located in a coastal, salt laden environment. The SHM provides sole capability to access and retrieve the inventory of over 1000 fuel skips. It is also fundamental to future operations and the deployment of de-sludging equipment to recover significant bulk sludge's from the pond floor. Failure of the SHM steelwork gantry at worst case could potentially result in the Skip Handler Machine being derailed. This has some potential to damage to the pond structure and at worst case may result in local radiological and environmental consequences. This paper will examine the challenges faced by the team as they successfully defined, planned and executed remedial work to a specific aspect of the civil structure, the SHM gantry rail system, using a purpose built refurbishment platform; the Gantry Refurbishment System. The paper will examine how an 'innovative' approach was adopted to resolve the related issues of: - Refurbishing an aged structure to meet extended future operational demands. - The application of pragmatic engineering solutions against current codes and standards including seismic performance; - Provision of safe access for the workforce to undertake the refurbishment work against significant radiological

  6. Par Pond refill water quality sampling

    International Nuclear Information System (INIS)

    Koch, J.W. II; Martin, F.D.; Westbury, H.M.

    1996-08-01

    This study was designed to document anoxia and its cause in the event that the anoxia caused a fish kill. However, no fish kill was observed during this study, and dissolved oxygen and nutrient concentrations generally remained within the range expected for southeastern reservoirs. Par Pond water quality monitoring will continue during the second summer after refill as the aquatic macrophytes become reestablished and nutrients in the sediments are released to the water column

  7. Engineered design of SSC cooling ponds

    International Nuclear Information System (INIS)

    Bear, J.B.

    1993-05-01

    The cooling requirements of the SSC are significant and adequate cooling water systems to meet these requirements are critical to the project's successful operation. The use of adequately designed cooling ponds will provide reliable cooling for operation while also meeting environmental goals of the project to maintain streamflow and flood peaks to preconstruction levels as well as other streamflow and water quality requirements of the Texas Water Commission and the Environmental Protection Agency

  8. Changes in tundra pond limnology: re-sampling Alaskan ponds after 40 years.

    Science.gov (United States)

    Lougheed, Vanessa L; Butler, Malcolm G; McEwen, Daniel C; Hobbie, John E

    2011-09-01

    The arctic tundra ponds at the International Biological Program (IBP) site in Barrow, AK, were studied extensively in the 1970s; however, very little aquatic research has been conducted there for over three decades. Due to the rapid climate changes already occurring in northern Alaska, identifying any changes in the ponds' structure and function over the past 30-40 years can help identify any potential climate-related impacts. Current research on the IBP ponds has revealed significant changes in the physical, chemical, and biological characteristics of these ponds over time. These changes include increased water temperatures, increased water column nutrient concentrations, the presence of at least one new chironomid species, and increased macrophyte cover. However, we have also observed significant annual variation in many measured variables and caution that this variation must be taken into account when attempting to make statements about longer-term change. The Barrow IBP tundra ponds represent one of the very few locations in the Arctic where long-term data are available on freshwater ecosystem structure and function. Continued monitoring and protection of these invaluable sites is required to help understand the implications of climate change on freshwater ecosystems in the Arctic.

  9. Beaver ponds increase methylmercury concentrations in Canadian shield streams along vegetation and pond-age gradients.

    Science.gov (United States)

    Roy, Virginie; Amyot, Marc; Carignan, Richard

    2009-08-01

    Beaver impoundments flood forested areas and may be important production sites for methylmercury (MeHg) because of the resulting enhanced microbial activity and oxygen depletion. The influence of 17 beaver impoundments on streamwater chemistry (total mercury (THg), MeHg, nutrients, cations, and anions)] was investigated by sampling sites located along vegetation and pond-age gradients in southwestern Quebec (Canada). Recently inundated beaver ponds (beaver ponds as suggested by depletions of dissolved oxygen, sulfate and nitrite-nitrate concentrations, and increases in nutrients (e.g., dissolved organic carbon, total phosphorus, and total nitrogen) in outlets compared to inlets. Acidic waters at coniferous sites may have stimulated more MeHg production than in mixed woodland regions. Lower methylation efficiencies in older ponds (> 20 years old) may be due to the degradation of less labile organic matter as ponds age. Beavers actively alter watersheds by building impoundments, and our findings indicate that this landscape disturbance may be a significant source of MeHg to downstream water bodies.

  10. Cooking without salt

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000760.htm Cooking without salt To use the sharing features on ... other dishes to add zest. Try Salt-free Cooking Explore cooking with salt substitutes. Add a splash ...

  11. Mechanisms for parasites removal in a waste stabilisation pond.

    Science.gov (United States)

    Reinoso, Roberto; Blanco, Saúl; Torres-Villamizar, Linda A; Bécares, Eloy

    2011-04-01

    A waste stabilisation pond (WSP) system formed by two anaerobic ponds, a facultative pond and a maturation pond was studied from December 2003 to September 2004 in north-western Spain in order to evaluate its efficiency in the removal of faecal indicator bacteria (total coliforms, Escherichia coli, faecal streptococci), coliphages, helminth eggs and protozoan (oo)cysts (Cryptosporidium and Giardia). Furthermore, sediment samples were collected from the bottom of the ponds to assess the settling rates and thus determine the main pathogen removal mechanisms in the WSPs system. The overall removal ranged from 1.4 log units for coliphages in the cold period to 5.0 log units for E. coli in the hot period. Cryptosporidium oocysts were reduced by an average of 96%, Giardia cysts by 98% and helminth eggs by 100%. The anaerobic ponds showed significantly higher surface removal rates (4.6, 5.2 and 3.7 log (oo)cysts/eggs removed m(-2) day(-1), respectively) than facultative and maturation ponds. Sunlight and water physicochemical conditions were the main factors influencing C. parvum oocysts removal both in the anaerobic and maturation ponds, whereas other factors like predation or natural mortality were more important in the facultative pond. Sedimentation, the most commonly proposed mechanism for cyst removal had, therefore, a negligible influence in the studied ponds.

  12. Rapid surface-water volume estimations in beaver ponds

    Science.gov (United States)

    Karran, Daniel J.; Westbrook, Cherie J.; Wheaton, Joseph M.; Johnston, Carol A.; Bedard-Haughn, Angela

    2017-02-01

    Beaver ponds are surface-water features that are transient through space and time. Such qualities complicate the inclusion of beaver ponds in local and regional water balances, and in hydrological models, as reliable estimates of surface-water storage are difficult to acquire without time- and labour-intensive topographic surveys. A simpler approach to overcome this challenge is needed, given the abundance of the beaver ponds in North America, Eurasia, and southern South America. We investigated whether simple morphometric characteristics derived from readily available aerial imagery or quickly measured field attributes of beaver ponds can be used to approximate surface-water storage among the range of environmental settings in which beaver ponds are found. Studied were a total of 40 beaver ponds from four different sites in North and South America. The simplified volume-area-depth (V-A-h) approach, originally developed for prairie potholes, was tested. With only two measurements of pond depth and corresponding surface area, this method estimated surface-water storage in beaver ponds within 5 % on average. Beaver pond morphometry was characterized by a median basin coefficient of 0.91, and dam length and pond surface area were strongly correlated with beaver pond storage capacity, regardless of geographic setting. These attributes provide a means for coarsely estimating surface-water storage capacity in beaver ponds. Overall, this research demonstrates that reliable estimates of surface-water storage in beaver ponds only requires simple measurements derived from aerial imagery and/or brief visits to the field. Future research efforts should be directed at incorporating these simple methods into both broader beaver-related tools and catchment-scale hydrological models.

  13. Evaluation of revegetation techniques of a saline flue gas desulfurization sludge pond

    Energy Technology Data Exchange (ETDEWEB)

    Salo, L.F.; Artiola, J.F.; Goodrich-Mahoney, J.W. [University of Arizona, Tucson, AZ (United States). Renewable National Resources

    1999-01-01

    Codisposal of flue gas desulfurization (FGD) sludge with low-volume generating station waste simplifies disposal but creates a saline, high boron (B) waste that may be difficult to revegetate after site closure. Studies on a delta of waste material in a codisposal pond at the coal-fired Coronado Generating Station in eastern Arizona evaluated management techniques, amendments, and plants for revegetating this material. One study investigated leaching and ridging techniques and a second evaluated amendment with manure, wood shavings, and fly ash, Four salt-tolerant grass species and four saltbushes (A triplex spp,) were evaluated in the two studies. Criteria for success were high survival rates and growth, as measured by grass height and shrub height x width. Leaching salts and B from the waste was not necessary for establishment and growth of transplanted shrubs and grasses. Ridging was not a successful technique, due to limited moisture and high levels of salinity and B on these structures. Gardner saltbush (A, gardneri (Moq.) D, Dietr.) and a fourwing saltbush (A. canescens (Pursh) Nutt,) accession from the site were the most successful shrubs and alkali sactonn (Sporobolus airoides (Torr,) Torr. `Saltalk`) was the most successful grass at this disposal pond. Amendment with manure, wood shavings, or fly ash did not increase plant survival. Growth of grasses was improved with all amendments and was greatest with manure, but growth of shrubs was not improved with any amendment. 33 refs., 8 tabs.

  14. Development of shrimp in small ponds

    Directory of Open Access Journals (Sweden)

    Armando Adolfo Ortega Salas

    2014-06-01

    Full Text Available Development of white shrimp Litopenaeus vannamei in small ponds ( 6 m3 in fresh water (2-3‰ and seawater; ponds 3.66 x 1.65 x 1.0 m; availability of fresh water, sea water, aeration and drainage. Two cycles of three months each were made. The postlarvae were acclimated to seawater fresh water in four days. Four hundred postlarvas/m3 were seeded in freshwater pond and 500 in the pool of seawater. First, a culture of Daphnia magna in the freshwater pond, also appeared chyronomid larvae; Artemia cysts were seeded in sea water as a dietary supplement. The shrimp were fed Camaronina (25% protein at libitum, daily; is offered on a tray of food; the temperature ranged between 27 and 30° C, oxygen 4.26 ± 1.43 mg / L , pH between 7 and 8 . Detritus siphoned every third day. Water changes between 10 and 20% are often performed. The feed conversion rate (FCR was 1:1.3 . The shrimp were measured in length and weight to calculate weekly growth by Bertalanffy model. Survival in the first cycle was 95.8 , and 97.9% for the second cycle. In seawater parameters of the population of the first cycle were k = 0.0301, L ∞ = 322.16 and t0 = -0.8852, the second cycle of k = 0.0203, L ∞ = 294.42 and t0 = -5.3771. The biomass of 27 kg was obtained for the first cycle and 16 kg for the second cycle. Freshwater population parameters of the first cycle were k = 0.0957, L ∞ = 146.98 and t0 = - 0.93; in the second cycle of k = 0.0172 , L ∞ = 367.82 and t0 = - 4.60. The biomass of 26 kg was obtained for the first cycle and 16 kg for the second cycle. The results indicate a rapid growth during the first 10 weeks. In small ponds can be handled well aseptic conditions without disease problems, good crop was obtained.

  15. Site-specific health and safety plan 100-D Pond remediation project

    International Nuclear Information System (INIS)

    Hobbs, B.J.

    1996-06-01

    The 100-D Ponds are located north of the northern perimeter fence of the 100-D Area. The ponds were excavated in a preexisting basin that had been used for disposal of coal ash. There are two ponds, one used as a settling pond and the other a percolation pond. Liquid effluent from the 100-D process sewers was discharged to the ponds from 1977 through 1987; after 1987 the ponds received backwash and rinsate from the 100-D water treatment facilities. All discharges to the ponds ceased in June 1994, and the ponds were allowed to dry up

  16. Geochemistry of the Upper Parana River floodplain. Study of the Garcas Pond and Patos Pond

    International Nuclear Information System (INIS)

    Marcelo Bevilacqua Remor; Silvio Cesar Sampaio; Marcio Antonio Vilas Boas; Ralpho Rinaldo dos Reis

    2015-01-01

    The aim of this study was to investigate the temporal evolution of the supply of chemical elements to the Upper Parana River floodplain and identify trends in the geochemistry of its drainage basin. The primary factor that regulates the supply of chemical elements of the Upper Parana River floodplain is the flood pulse, which can be magnified by the El Nino-Southern Oscillation. Garcas Pond is affected by agriculture, urbanization, discharge of industrial effluents and hydroelectric power production activities. Patos Pond is affected by sugarcane burning, gold mining, agriculture and urbanization. (author)

  17. The western pond turtle: Habitat and history. Final report

    International Nuclear Information System (INIS)

    Holland, D.C.

    1994-08-01

    The western pond turtle is known from many areas of Oregon. The majority of sightings and other records occur in the major drainages of the Klamath, Rogue, Umpqua, Willamette and Columbia River systems. A brief overview is presented of the evolution of the Willamette-Puget Sound hydrographic basin. A synopsis is also presented of the natural history of the western pond turtle, as well as, the status of this turtle in the Willamette drainage basin. The reproductive ecology and molecular genetics of the western pond turtle are discussed. Aquatic movements and overwintering of the western pond turtle are evaluated. The effect of introduced turtle species on the status of the western pond turtle was investigated in a central California Pond. Experiments were performed to determine if this turtle could be translocated as a mitigation strategy

  18. Bioaccumulation of heavy metals in two wet retention ponds

    DEFF Research Database (Denmark)

    Søberg, Laila C.; Vollertsen, Jes; Blecken, Godecke-Tobias

    2016-01-01

    Metal accumulation in stormwater ponds may contaminate the inhabiting fauna, thus jeopardizing their ecosystem servicing function. We evaluated bioaccumulation of metals in natural fauna and caged mussel indicator organisms in two wet retention ponds. Mussel cages were distributed throughout...... the ponds to detect bioaccumulation gradients and obtain a time-integrated measure of metal bioavailability. We further investigated if sediment metal concentrations correlate with those in the fauna and mussels. Metal concentrations in the fauna tended to be higher in the ponds than in a reference lake......, but statistical significance was only shown for Cu. Positive correlations were found for some metals in fauna and sediment. Sediment metal concentrations in one pond decreased from inlet to outlet while no gradients were observed in the mussels in either pond. These findings indicate that metal accumulation...

  19. Relationship Between Accumulation and Influx of Pollutants in Highway Ponds

    DEFF Research Database (Denmark)

    Bentzen, Thomas Ruby; Larsen, Torben; Rasmussen, Michael R.

    The paper discusses the long term mass balance of pollutants in highway ponds. The accumulations of five polycyclic aromatic hydrocarbons (PAHs) and six heavy metals have been measured in eight Danish detention ponds, which receive runoff from highways only. For each pollutant the accumulation has...... been compared to the long-term influx, estimated from short-term measurements of concentrations in highway runoff. The results show that a large proportion of the incoming heavy metals in short-term runoff events has accumulated in the ponds. This is not the case for the toxic organic compounds....... The results also show that the accumulation rates for the heavy metals depend significantly on the relative pond area (pond area divided by catchment area). The conclusion is that the mass balances of heavy metals and PAHs in highway ponds can be estimated with acceptable accuracy from a combination of short...

  20. Samples of Asteroid Surface Ponded Deposits in Chondritic Meteorites

    Science.gov (United States)

    Zolensky, M. E.; Lee, R.; Le, L.

    2004-01-01

    One of the many unexpected observations of asteroid 433 Eros by the Near Earth Asteroid Rendezvous (NEAR) mission was the many ponds of fine-grained materials [1-3]. The ponds have smooth surfaces, and define equipotential surfaces up to 10's of meters in diameter [4]. The ponds have a uniformly sub-cm grain size and appear to be cohesive or indurated to some degree, as revealed by slumping. The ponds appear to be concentrated within 30 degrees of the equator of Eros, where gravity is lowest. There is some insight into the mineralogy and composition of the ponds surfaces from NEAR spectroscopy [2,4,5,6]. Compared to the bulk asteroid, ponds: (1) are distinctly bluer (high 550/760 nm ratio), (2) have a deeper 1um mafic band, (3) have reflectance elevated by 5%.

  1. Simple intervention to reduce mosquito breeding in waste stabilisation ponds

    DEFF Research Database (Denmark)

    Ensink, Jeroen H J; Mukhtar, Muhammad; van der Hoek, Wim

    2007-01-01

    Waste stabilisation ponds (WSP) are the preferred method for treatment of urban wastewater in low-income countries but, especially in arid regions, the pond systems can be important breeding sites for mosquitoes of medical importance. In a WSP system in Faisalabad, Pakistan, we assessed the impact...... of simple environmental interventions on mosquito occurrence and abundance. Reducing the amount of floating matter in the ponds, eliminating emergent vegetation and repairing cracks in the cement structure reduced the number of mosquito-positive samples in the intervention ponds to almost zero, whereas...... the control ponds had a significant number of positive samples. This suggests that a combination of simple low-cost interventions is a feasible environmental management strategy for vector control in WSP systems that are located in areas where medically important mosquitoes may breed in the shallow ponds....

  2. Transition in the fractal geometry of Arctic melt ponds

    Directory of Open Access Journals (Sweden)

    C. Hohenegger

    2012-10-01

    Full Text Available During the Arctic melt season, the sea ice surface undergoes a remarkable transformation from vast expanses of snow covered ice to complex mosaics of ice and melt ponds. Sea ice albedo, a key parameter in climate modeling, is determined by the complex evolution of melt pond configurations. In fact, ice–albedo feedback has played a major role in the recent declines of the summer Arctic sea ice pack. However, understanding melt pond evolution remains a significant challenge to improving climate projections. By analyzing area–perimeter data from hundreds of thousands of melt ponds, we find here an unexpected separation of scales, where pond fractal dimension D transitions from 1 to 2 around a critical length scale of 100 m2 in area. Pond complexity increases rapidly through the transition as smaller ponds coalesce to form large connected regions, and reaches a maximum for ponds larger than 1000 m2, whose boundaries resemble space-filling curves, with D ≈ 2. These universal features of Arctic melt pond evolution are similar to phase transitions in statistical physics. The results impact sea ice albedo, the transmitted radiation fields under melting sea ice, the heat balance of sea ice and the upper ocean, and biological productivity such as under ice phytoplankton blooms.

  3. Avifauna of waste ponds ERDA Hanford Reservation, Benton County, Washington

    International Nuclear Information System (INIS)

    Fitzner, R.E.; Rickard, W.H.

    1975-06-01

    The presence of small ponds on the Hanford 200 Area plateau provides attractive habitats for birds. During a 29-month period, 126 bird species were observed utilizing these ponds, their associated vegetation, and air space. Waterfowls are the important agents of dispersal of radionuclides from waste ponds based on food habits, abundance, migratory habits, and importance as food in the diet of people. Abundance, long residence time, and food habits identify the American coot as the single most important species to be considered in the biological dispersal of radionuclides from waste ponds. (U.S.)

  4. Full-energy-chain analysis of greenhouse gas emissions for solar thermal electric power generation systems

    International Nuclear Information System (INIS)

    Norton, B.; Lawson, W.R.

    1997-01-01

    Technical attributes and environmental impacts of solar thermal options for centralized electricity generation are discussed. In particular, the full-energy-chain, including embodied energy and energy production, is considered in relation to greenhouse gas emission arising from solar thermal electricity generation. Central receiver, parabolic dish, parabolic trough and solar pond systems are considered. (author)

  5. International experience in tailings pond remediation

    International Nuclear Information System (INIS)

    Robertson, A.MacG.

    2001-01-01

    Tailings pond remediation is required primarily on mine closure. While mining is an ancient industry, requirement for mine facility remediation is a comparatively new development. Requirement for remediation has come about partly as a result of mans awareness of the environmental impacts of mining and his desire to minimize this, partly, as a result of the ever-increasing scale and production rates of tailings generation and the resulting increased environmental impacts and safety risks. The paper starts with a review of the evolution of mans intolerance of environmental impacts from tailings production and the assignment of liability to remediate such impacts. Many of the tailings ponds currently undergoing remediation were designed and constructed using methods and technology that would be considered inappropriate for new impoundments being designed and developed today. The paper reviews the history of tailings impoundment design and construction practice and the resulting inherent deficiencies that must be remediated. Current practices and future trends in tailings pond remediation are reviewed. The evolution of regulatory requirements is not only in terms of technical and safety criteria, but also in terms of financial and political risk. Perhaps the most substantive driver of risk management is today the requirement for corporate governance at mining company board level and oversight of new project development in the underdeveloped countries by the large financial institutions responsible for funding projects. Embarrassment in the public eye and punishment in the stock markets for poor environmental and safety performance is driving the need for efficient and effective risk management of potential impacts and the remediation to avoid these. A basis for practical risk management is described. (orig.)

  6. International experience in tailings pond remediation

    Energy Technology Data Exchange (ETDEWEB)

    MacG. Robertson, A. [Robertson GeoConsultants Ltd., Vancouver (Canada)

    2001-07-01

    Tailings pond remediation is required primarily on mine closure. While mining is an ancient industry, requirement for mine facility remediation is a comparatively new development. Requirement for remediation has come about partly as a result of mans awareness of the environmental impacts of mining and his desire to minimize this, partly, as a result of the ever-increasing scale and production rates of tailings generation and the resulting increased environmental impacts and safety risks. The paper starts with a review of the evolution of mans intolerance of environmental impacts from tailings production and the assignment of liability to remediate such impacts. Many of the tailings ponds currently undergoing remediation were designed and constructed using methods and technology that would be considered inappropriate for new impoundments being designed and developed today. The paper reviews the history of tailings impoundment design and construction practice and the resulting inherent deficiencies that must be remediated. Current practices and future trends in tailings pond remediation are reviewed. The evolution of regulatory requirements is not only in terms of technical and safety criteria, but also in terms of financial and political risk. Perhaps the most substantive driver of risk management is today the requirement for corporate governance at mining company board level and oversight of new project development in the underdeveloped countries by the large financial institutions responsible for funding projects. Embarrassment in the public eye and punishment in the stock markets for poor environmental and safety performance is driving the need for efficient and effective risk management of potential impacts and the remediation to avoid these. A basis for practical risk management is described. (orig.)

  7. Comparison of phytoplankton communities in catfish split-pond aquaculture systems with conventional ponds

    Science.gov (United States)

    There has been a growing interest and use of variations of partitioned aquaculture systems (PAS) in recent years by the southeastern United States of America farmed catfish industry. Split-pond systems, one type of PAS, are designed to better manage fish waste byproducts (e.g., ammonia) and dissolv...

  8. Thermal performance experiments on ultimate heat sinks, spray ponds, and cooling ponds

    International Nuclear Information System (INIS)

    Hadlock, R.K.

    1976-12-01

    A program of measurement on a Battelle-Northwest (BNW) spray pond has been completed to prove an integrated instrumentation system for application in future field experiments. The measurement programs in the field will produce data of relevance to the design and understanding of performance for ultimate heat sinks as components of emergency core cooling systems. In the absence of active emergency cooling systems, the data will be obtained on analog systems--prime candidates among these are the naturally-occurring hot ponds at Yellowstone National Park and man-made hot cooling ponds at Savannah River National Laboratory as well as spray ponds at various industrial facilities. The proof experiment has provided data that not only illustrate the effectiveness of the instrumentation system but also display interesting site-specific heat transfer processes. The data to be obtained in the field will also be site specific but must be of generic applicability in modeling for design and performance purposes. The integrated instrumentation system will evolve, through modest modifications and substantial supplementation, to provide the requisite data for the more demanding situation of work in and about hot water

  9. Phyllosphere mycobiota on garden ponds plants

    Directory of Open Access Journals (Sweden)

    Maria Kowalik

    2013-12-01

    Full Text Available Investigations were conducted on calamus, common cattail, soft rush, yellow iris and white water lily plants in twenty ponds in Malopolska and Podkarpacie Regions. Mycobiota existing in the phyllosphere caused discolouring and necroses of leaves and shoots. 88 species of mycobiota were identified and isolated from the diseased tissues. Dominant were Alternaria alternata, Epicoccum nigrum and Isaria farinosa. Fungi of genera: Aspergillus, Botrytis, Chaetomium, Cladosporium, Fusarium, Ilyonectria, Mortierella, Mucor, Penicillium, Phialophora, Phoma, Pleustomophora, Sordaria, Trichoderma and Umbelopsis were also numerous. The monophagous and the polyphagous were identified.

  10. Comparison between field data and ultimate heat-sink cooling-pond and spray-pond models

    International Nuclear Information System (INIS)

    Codell, R.

    1982-09-01

    Two previously published reports, NUREG-0693 and NUREG-0733, presented models and methods by which ultimate heat sink cooling ponds and spray ponds used for safety-related water supplies in nuclear power plants could be analyzed for design-basis conditions of heat load and meteorology. These models were only partially verified with field data. The present report compares the NRC models to data collected for NRC by Battelle Pacific Northwest Laboratories on the performance of small geothermally heated ponds and spray ponds. These comparisons generally support the conclusion that the NRC models are useful tools in predicting ultimate heat sink performance

  11. Solar Still Coupled With Solar Collector and Storage Tank

    OpenAIRE

    Rajesh, A. M.; Bharath, K. N.

    2010-01-01

    Acute shortage of good, clean drinking water is a major problem for most developing countries of the world. In most cases, ponds, streams, wells and rivers are often polluted that they are unsafe for direct use as drinking water >.Often water sources are brackish and or contain harmful bacteria. Therefore cannot be used for drinking .In addition there are many coastal locations where sea water is abundant but potable water is not available. Solar distillation is one of the important methods o...

  12. PERFORMANCES OF TIGER SHRIMP CULTURE IN ENVIRONMENTALLY FRIENDLY PONDS

    Directory of Open Access Journals (Sweden)

    Taufik Ahmad

    2016-10-01

    Full Text Available Mangrove ecosystem plays an obvious role in maintaining the biological balance in the coastal environment where shrimp ponds are usually constructed. The removal of mangroves around shrimp ponds has frequently brought about harvest failure. The study evaluated the performance of tiger shrimp culture in ponds provided with water from a water body where there was mangrove vegetation (hereafter mangrove reservoir. Twelve ponds, each measuring 2,500 m2, were filled with seawater from the mangrove reservoir until the water depth of 100 cm and then stocked with 20-40 PL/m2. In the first six ponds, the bottom water was released into the reservoir when the water depth reached 140 cm and then the water depth was maintained at 100 cm. In the second six ponds, the water was released from the ponds until the water depth reached 60 cm and then refilled with reservoir water until a depth of 100 cm. Both treatment ponds received water from the reservoir which also received the wastewater. The feeds for the shrimps were broadcast into the ponds twice a day to meet the 3% shrimp biomass requirement, which adjusted every other week through sampling. The result showed that mangrove  vegetation is capable of removing excessive nutrients, up to 70% for NO3- N and NH4 +-N, reducing PO4 =-P fluctuation, and producing bioactive  compounds. In the second treatment ponds, shrimp mortality started to occur in day 28 and most died by day 54 after stocking due to white spot disease outbreak. Mass mortality took place 54 days after stocking in two out of six of the first treatment ponds.

  13. First description of underwater acoustic diversity in three temperate ponds

    Directory of Open Access Journals (Sweden)

    Camille Desjonquères

    2015-11-01

    Full Text Available The past decade has produced an increased ecological interest in sonic environments, or soundscapes. However, despite this rise in interest and technological improvements that allow for long-term acoustic surveys in various environments, some habitats’ soundscapes remain to be explored. Ponds, and more generally freshwater habitats, are one of these acoustically unexplored environments. Here we undertook the first long term acoustic monitoring of three temperate ponds in France. By aural and visual inspection of a selection of recordings, we identified 48 different sound types, and according to the rarefaction curves we calculated, more sound types are likely present in one of the three ponds. The richness of sound types varied significantly across ponds. Surprisingly, there was no pond-to-pond daily consistency of sound type richness variation; each pond had its own daily patterns of activity. We also explored the possibility of using six acoustic diversity indices to conduct rapid biodiversity assessments in temperate ponds. We found that all indices were sensitive to the background noise as estimated through correlations with the signal-to-noise ratio (SNR. However, we determined that the AR index could be a good candidate to measure acoustic diversities using partial correlations with the SNR as a control variable. Yet, research is still required to automatically compute the SNR in order to apply this index on a large data set of recordings. The results showed that these three temperate ponds host a high level of acoustic diversity in which the soundscapes were variable not only between but also within the ponds. The sources producing this diversity of sounds and the drivers of difference in daily song type richness variation both require further investigation. Such research would yield insights into the biodiversity and ecology of temperate ponds.

  14. Examining Water Quality Variations of Tidal Pond System

    Science.gov (United States)

    Chui, T. F. M.; Cui, W.

    2014-12-01

    Brackish tidal shrimp ponds, traditionally referred to as gei wais, have been constructed along coastal areas in many parts of the world. The regular exchange of pond water with the surrounding coastal environment is important as it brings shrimp larvae and nutrients, etc. into and out of the pond. Such a water exchange can reduce the quality of the receiving waters; though there are opposing views recently because farming practices are becoming more sustainable while other sources of pollutions in the surroundings are increasing. This project monitors the water quality of a tidal shrimp pond and its receiving water at high temporal resolution. The pond is located within the wetland complex of Mai Po Nature Reserve in Hong Kong, China. Water quality parameters (i.e., dissolved oxygen, temperature, salinity, pH, water depth and chlorophyll) were recorded at 15-minute interval from December 2013 to March 2014 within the pond and also at its receiving water which is a water channel within a mangrove forest. Data reveals both daily and fortnightly fluctuations. Daily variations in mangrove correspond to both tidal flushing and insolation, whereas those within the pond correspond mainly to insolation. For example, dissolved oxygen in mangrove shows two peaks daily which correlate with tidal elevation, and that within the pond shows only one peak which correlates with sunlight. Dissolved oxygen within the pond also shows a fortnightly pattern that corresponds to the schedule of water exchange. Such high temporal resolution of monitoring reveals the two-way water quality influences between the pond and the mangrove. It sheds insights that can possibly lead to refinement of water exchange practice and water sampling schedule given the temporal variations of the water quality both inside and outside the pond. It thus enables us to take a step closer in adopting more sustainable farming practices despite increasing pollution in the surrounding areas.

  15. Capturing temporal and spatial variability in the chemistry of shallow permafrost ponds

    Science.gov (United States)

    Morison, Matthew Q.; Macrae, Merrin L.; Petrone, Richard M.; Fishback, LeeAnn

    2017-12-01

    Across the circumpolar north, the fate of small freshwater ponds and lakes (mediated by processes within ponds. This work demonstrates the importance of understanding hydrologically driven chemodynamics in permafrost ponds on multiple scales (seasonal and event scale).

  16. Mixed Waste Salt Encapsulation Using Polysiloxane - Final Report

    International Nuclear Information System (INIS)

    Miller, C.M.; Loomis, G.G.; Prewett, S.W.

    1997-01-01

    A proof-of-concept experimental study was performed to investigate the use of Orbit Technologies polysiloxane grouting material for encapsulation of U.S. Department of Energy mixed waste salts leading to a final waste form for disposal. Evaporator pond salt residues and other salt-like material contaminated with both radioactive isotopes and hazardous components are ubiquitous in the DOE complex and may exceed 250,000,000 kg of material. Current treatment involves mixing low waste percentages (less than 10% by mass salt) with cement or costly thermal treatment followed by cementation to the ash residue. The proposed technology involves simple mixing of the granular salt material (with relatively high waste loadings-greater than 50%) in a polysiloxane-based system that polymerizes to form a silicon-based polymer material. This study involved a mixing study to determine optimum waste loadings and compressive strengths of the resultant monoliths. Following the mixing study, durability testing was performed on promising waste forms. Leaching studies including the accelerated leach test and the toxicity characteristic leaching procedure were also performed on a high nitrate salt waste form. In addition to this testing, the waste form was examined by scanning electron microscope. Preliminary cost estimates for applying this technology to the DOE complex mixed waste salt problem is also given

  17. Naphtha evaporation from oil sands tailings ponds

    Energy Technology Data Exchange (ETDEWEB)

    Kasperski, K.; Munoz, V.; Mikula, R. [Natural Resources Canada, Devon, AB (Canada). CANMET Western Research Centre

    2010-07-01

    The environmental impacts of volatile organic compounds (VOCs) from oil sands tailings ponds must be considered when evaluating new oil sands mining and extraction operations. Studies have suggested that only 40 percent of the solvent sent to tailings ponds is available to the environment, while the rest is irreversibly trapped. The recovery of hydrocarbons from oil sands froth process water is low. This PowerPoint presentation discussed a method of distinguishing between water and hydrocarbons at low temperatures. Samples were heated to 246 degrees C at 15 degrees C and held for 10 minutes. Heating was then resumed at 750 degrees C and held for 10 minutes in a pyrolysis phase, then cooled and reheated with an oxygen addition. The method demonstrated that the diluent distribution between the solids and water phases is misinterpreted as diluent that will evaporate, and diluent that will not evaporate. The study concluded by suggesting that the definition of recoverable and unrecoverable hydrocarbon should be re-termed as easily recoverable, and difficult to recover. tabs., figs.

  18. Spray pond design for nuclear power plants

    International Nuclear Information System (INIS)

    Codell, R.B.; Asce, A.M.

    1986-01-01

    This paper presents a complex methodology for assessing the performance of spray ponds in ultimate heat sink service at nuclear power plants. A spray pond performance model, developed in the companion paper, is used in conjunction with on-site and off-site meteorological data to predict the highest temperature and greatest 30 day water loss which can reasonable be expected to occur during the lifetime of the plant. The performance model for heat and mass transfer is used to develop an efficient phenomenological model used to scan the long-term meteorological records. Refined estimates of temperature or water loss may then be based on more complicated models if necessary. Short-term onsite data are correlated to the long-term off-site data to formulate correction factors for the difference in location. Cumulative distribution functions for temperature and water loss are determined from the long-term meteorological records to predict the occurrence of these quantities which are less severe that the peak. The methodology is demonstrated using data and parameters from the Palo Verde nuclear plant as an example

  19. 2101-M Pond hydrogeologic characterization report

    Energy Technology Data Exchange (ETDEWEB)

    Chamness, M.A.; Luttrell, S.P.; Bates, D.J.; Martin, W.J.

    1990-09-01

    This report documents information collected by the Pacific Northwest Laboratory {sup (a)} at the request of Westinghouse Hanford Company. Presented in this report is the interpretation of the hydrogeologic environment at the 2101-M Pond, located in the 200-East Area of the Hanford Site. This information and its accompanying interpretation were derived from sampling and testing activities associated with the installation of four ground-water monitoring wells, in addition to data gathered from several previously existing wells. The new monitoring wells were installed as part of a groundwater monitoring program initiated in 1988. The four new monitoring wells were installed around the 2101-M Pond between May 23 and August 27, 1988. Geologic sampling, aquifer testing, and initial ground-water sampling were performed during the installation of these wells. Laboratory analyses of the sediment samples for particle size, calcium carbonate content, and selected natural and contaminant constituents were performed. A full year of quarterly ground-water sampling and the first statistical analysis of background and downgradient data have also been performed. 112 refs., 49 figs., 18 tabs.

  20. Lanthanide behavior in hypersaline evaporation ponds at Guerrero Negro, Baja California, Mexico - an environment with halophiles

    Science.gov (United States)

    Choumiline, K.; López-Cortés, A.; Grajeda-Muñoz, M.; Shumilin, E.; Sapozhnikov, D.

    2013-12-01

    Lanthanides are known, in some cases, to be sensitive to changes in water column or sediment chemistry, a fact that allows them to be used as environmental fingerprints. Nevertheless, the behavior of these elements in hypersaline environments is insufficiently understood, especially in those colonized by bacteria, archaea and eukarya halophiles. Extreme environments like the mentioned exist in the artificially-controlled ponds of the 'Exportadora de Sal' salt-producing enterprise located in Guerrero Negro (Baja California, Mexico). Sediment cores from various ponds were collected, subsampled and measured by ICP-MS and INAA. This allowed differencing the behavior of lanthanides and trace elements under a water column salinity gradient along the evaporation sequence of ponds. Sediment profiles (30 mm long), obtained in Pond 5, dominated by Ca and Mg precipitation and at the same time rich in organic matter due to bacterial mat presence, showed highs and lows of the shale-normalized patterns along different in-core depths. Two groups of elements could be distinguished with similar trends: set A (La, Ce, Pr and Nd) and set B (Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu). The first 'group A' had two prominent peaks at 15 mm and around 22 mm, whereas the 'group B' showed only slight increase at 15 mm and none at 22 mm. Microscopic analyses of prokaryotic cells of a stratified mat in Pond 5 (collected in 2004) showed filamentous bacteria and cyanobacteria with a cell abundance and morphotype richness maxima of prokaryotic cells in a chemocline from 3 mm to 7 mm depth which co-exists nine morphotypes of aerobic and anaerobic prokaryotes Microcoleus chthonoplastes, Leptolyngbya, Cyanothece, Geitlerinema, Spirulina, Chloroflexus, Beggiatoa, Chromatium and Thioploca. Below the 7 mm depth, oxygenic photosynthesis depletes and sulfur reducing compounds increase. The highs of the shale-normalized lanthanide contents of the 'group A' (at 15 mm depth) seem to correlate with the

  1. Pond bank access as an approach for managing toxic cyanobacteria in beef cattle pasture drinking water ponds.

    Science.gov (United States)

    Wilson, Alan E; Chislock, Michael F; Yang, Zhen; Barros, Mário U G; Roberts, John F

    2018-03-25

    Forty-one livestock drinking water ponds in Alabama beef cattle pastures during were surveyed during the late summer to generally understand water quality patterns in these important water resources. Since livestock drinking water ponds are prone to excess nutrients that typically lead to eutrophication, which can promote blooms of toxigenic phytoplankton such as cyanobacteria, we also assessed the threat of exposure to the hepatotoxin, microcystin. Eighty percent of the ponds studied contained measurable microcystin, while three of these ponds had concentrations above human drinking water thresholds set by the US Environmental Protection Agency (i.e., 0.3 μg/L). Water quality patterns in the livestock drinking water ponds contrasted sharply with patterns typically observed for temperate freshwater lakes and reservoirs. Namely, we found several non-linear relationships between phytoplankton abundance (measured as chlorophyll) and nutrients or total suspended solids. Livestock had direct access to all the study ponds. Consequently, the proportion of inorganic suspended solids (e.g., sediment) increased with higher concentrations of total suspended solids, which underlies these patterns. Unimodal relationships were also observed between microcystin and phytoplankton abundance or nutrients. Euglenoids were abundant in the four ponds with chlorophyll concentrations > 250 μg/L (and dominated three of these ponds), which could explain why ponds with high chlorophyll concentrations would have low microcystin concentrations. Based on observations made during sampling events and available water quality data, livestock-mediated bioturbation is causing elevated total suspended solids that lead to reduced phytoplankton abundance and microcystin despite high concentrations of nutrients, such as phosphorus and nitrogen. Thus, livestock could be used to manage algal blooms, including toxic secondary metabolites, in their drinking water ponds by allowing them to walk in the

  2. Biological removal of algae in an integrated pond system

    CSIR Research Space (South Africa)

    Meiring, PGJ

    1995-01-01

    Full Text Available A system of oxidation ponds in series with a biological trickling filter is described. It was known that this arrangement was incapable of reducing effectively the levels of algae present in the pond liquid even though nitrification was effected...

  3. Modeling the summertime evolution of sea-ice melt ponds

    DEFF Research Database (Denmark)

    Lüthje, Mikael; Feltham, D.L.; Taylor, P.D.

    2006-01-01

    We present a mathematical model describing the summer melting of sea ice. We simulate the evolution of melt ponds and determine area coverage and total surface ablation. The model predictions are tested for sensitivity to the melt rate of unponded ice, enhanced melt rate beneath the melt ponds...

  4. Assessment of waste stabilization ponds (WSP) efficiency on ...

    African Journals Online (AJOL)

    This stage is essential for polishing water and nutrient as well as pathogen removal. There is need of frequent awareness campaign to a community for the reuse of wastewater for agriculture and its possible impacts. Ponds should be modified and addition of maturation ponds constructed. Further studies are required for ...

  5. Arthropod fauna of the University of Nigeria, Nsukka, Sewage pond ...

    African Journals Online (AJOL)

    A survey of arthropod fauna of the University of Nigeria Nsukka sewage pond was carried out within May and June 2011. The aim was to determine the various arthropod species and its abundance in the sewage pond. The analysis was carried out by two methods, physico-chemical analysis and arthropod faunal studies.

  6. Feeding selectivity of wild and pond-cultured Nile tilapia ...

    African Journals Online (AJOL)

    A comparison of feeding selectivity of wild and pond-cultured Nile tilapia Oreochromis niloticus was conducted in 2008. Water and fish samples were collected in Shirati Bay, Lake Victoria, and from fish ponds in Tarime district using a La Motte water sampler and seine nets, respectively. Cyanophytes were abundant and ...

  7. Effects of riparian buffers on hydrology of northern seasonal ponds

    Science.gov (United States)

    Randall K. Kolka; Brian J. Palik; Daniel P. Tersteeg; James C. Bell

    2011-01-01

    Although seasonal ponds are common in northern, glaciated, forested landscapes, forest management guidelines are generally lacking for these systems. The objective of this study was to determine the effect of riparian buffer type on seasonal pond hydrology following harvest of the adjacent upland forest. A replicated block design consisting of four buffer treatments...

  8. Fertilization of Earth Ponds. II: Effects on Plankton Communities ...

    African Journals Online (AJOL)

    A study of the effects of slurry inorganic and organic of fertilizers on the production of phyto-and zooplankton in earth ponds was conducted in Central Scotland, U.K. over a period of one year. For the inorganic fertilization, replicate ponds were treated with low and high phosphorus (LP, HP), high phosphorus and nitrogen ...

  9. Mathematical modeling of dissolved oxygen in fish ponds ...

    African Journals Online (AJOL)

    Mathematical modeling of dissolved oxygen in fish ponds. WJS Mwegoha, ME Kaseva, SMM Sabai. Abstract. A mathematical model was developed to predict the effects of wind speed, light, pH, Temperature, dissolved carbon dioxide and chemical oxygen demand (COD) on Dissolved Oxygen (DO) in fish ponds. The effects ...

  10. Walden Pond, Massachusetts: Environmental Setting and Current Investigations

    Science.gov (United States)

    Colman, John A.; Waldron, Marcus C.

    1998-01-01

    Introduction Walden Pond, in Concord, Massachusetts, is famous among lakes because of its unique social history. Walden was the setting for American naturalist Henry David Thoreau's well-known essay 'Walden; or, Life in the Woods,' first published in 1854. Thoreau lived and wrote at Walden Pond from July 1845 to September 1847. In 'Walden,' Thoreau combined highly admired writing on Transcendental philosophy with pioneering observations of aquatic ecology and physical aspects of limnology, the study of lakes. Because Thoreau also defended so effectively the value of living close to nature in the Walden woods, the pond is considered by many to be the birthplace of the American conservation movement. Visitors come from all over the world to the pond, which has been designated a National Historic Landmark, and its fame has resulted in a major fund drive to preserve the surrounding woods. Walden Pond has no surfacewater inflow or outflow, and much of its ground-water contributing area likely is preserved within the Walden Pond Reservation area (fig. 1). Only 15 miles from Boston, the pond is unusually clear and pristine for an urban-area lake. However, point sources of nutrients near the pond, and a large annual visitor attendance, concentrated during the summer when the swimming beach (fig. 2) is open, may contribute a nutrient load sufficient to change the pond environment. The occurrence of nuisance algal species, a recent beach closing, and an awareness of water-quality problems suffered by other ponds in the region raise concerns about the risk of ecological change at Walden Pond. Despite the role of Walden Pond as a cultural and environmental icon, little is known about the pond's ecological features, such as its internal nutrient cycling or the structure of its food web, nor have consistent measurements been made to determine whether these features are changing or are stable. Production rates of aquatic plants in lakes and ponds naturally undergo a slow increase

  11. The evaporation from ponds in the French Midwest

    Directory of Open Access Journals (Sweden)

    Mohammad AL DOMANY

    2013-12-01

    Full Text Available This research shows the results of a study about evaporation in five ponds in the Midwest of France. To realize this study we used climate data from the meteorological station of the Limoges-Bellegarde airport and the data of a weather station installed by us near one of the ponds. We used eight different methods to calculate the evaporation rate and we modified the Penman-Monteith method by replacing the air temperature by water temperature. To understand the role of ponds in water loss through evaporation, we proposed a hypothesis that says : if the pond did not exist, what results would we get? Based on this hypothesis we calculated the potential evapotranspiration rate taking into account the percentage of interception by vegetation. In conclusion, this study indicates that the ponds in the French Midwest present a gain of water

  12. [Historical roles of salt].

    Science.gov (United States)

    Ritz, E; Ritz, C

    2004-12-17

    Recently increasing evidence has been provided pointing to a close relation of salt consumption to hypertension as well as to target organ damage. It is interesting to note that the discussion concerning salt is unusually emotional. This may be explained, at least in part, by the fact that since ancient times salt had deep symbolic significance, as exemplified, mostly subconsciously, by many customs and expressions still in current use. In the past salt was essential to preserve food. The past importance of salt as a commodity can well be compared with that of oil today. These and further historical aspects of the role of salt are briefly dealt with in this article.

  13. Vanishing Ponds and Regional Water Resources in Taoyuan, Taiwan

    Directory of Open Access Journals (Sweden)

    Yuei-An Liou

    2015-01-01

    Full Text Available Taiwan has a Subtropic to Tropical climate, but its precipitation varies widely in response to seasonal effects and weather events such as Typhoon and Meiyu systems. Precipitation must be held back in reservoirs to provide and regulate sufficient water supply. Balancing the irregular precipitation and increasing water demands generates tremendous pressure on water resources management for the water stored in the Shihmen Reservoir, which is the major unitary water supply system in the Greater Taoyuan Area. Such pressure will be significantly enlarged due to the huge 17 billion USD Taoyuan Aerotropolis Project. In earlier days many small artificial ponds (a common terminology in this article, including irrigation ponds, fishery ponds and others, were built to cope with water shortages in Taoyuan County. These small storage ponds provided a solution that resolved seasonal precipitation shortages. Unfortunately, these ponds have been vanishing one after another one due to regional industrialization and urbanization in recent decades and less than 40% of them still remain today. There is great urgency and importance to investigating the link between vanishing ponds and water resources management. Remote sensing technology was used in this study to monitor the environmental consequences in the Taoyuan area by conducting multi-temporal analysis on the changes in water bodies, i.e., ponds. SPOT satellite images taken in 1993, 2003, and 2010 were utilized to analyze and assess the importance of small-scale ponds as water conservation facilities. It was found that, during the seventeen years from 1993 - 2010, the number of irrigation ponds decreased by 35.94%. These ponds can reduce the burden on the major reservoir and increase the water recycling rate if they are properly conserved. They can also improve rainfall interception and surface detention capabilities, and provide another planning advantage for regional water management.

  14. Characterizing bacterial communities in tilapia pond surface sediment and their responses to pond differences and temporal variations.

    Science.gov (United States)

    Fan, Limin; Barry, Kamira; Hu, Gengdong; Meng, Shunlong; Song, Chao; Qiu, Liping; Zheng, Yao; Wu, Wei; Qu, Jianhong; Chen, Jiazhang; Xu, Pao

    2017-01-01

    Bacterial community compositions in the surface sediment of tilapia ponds and their responses to pond characteristics or seasonal variations were investigated. For that, three ponds with different stocking densities were selected to collect the samples. And the method of Illumina high-throughput sequencing was used to amplify the bacterial 16S rRNA genes. A total of 662, 876 valid reads and 5649 operational taxonomic units were obtained. Further analysis showed that the dominant phyla in all three ponds were Proteobacteria, Bacteroidetes, Chloroflexi, and Acidobacteria. The phyla Planctomycetes, Firmicutes, Chlorobi, and Spirochaetae were also relatively abundant. Among the eight phyla, the abundances of only Proteobacteria, Bacteroidetes, Firmicutes, and Spirochaetae were affected by seasonal variations, while seven of these (with the exception of Acidobacteria) were affected by pond differences. A comprehensive analysis of the richness and diversity of the bacterial 16S rRNA gene, and of the similarity in bacterial community composition in sediment also showed that the communities in tilapia pond sediment were shaped more by pond differences than by seasonal variations. Linear discriminant analysis further indicated that the influences of pond characteristics on sediment bacterial communities might be related to feed coefficients and stocking densities of genetically improved farmed tilapia (GIFT).

  15. Par Pond phytoplankton in association with refilling of the pond: Final Report for sampling from February 1995 -- September 1996

    International Nuclear Information System (INIS)

    Wilde, E.W.; Johnson, M.A.; Cody, W.C.

    1996-01-01

    This report describes the results of phytoplankton analyses from Par Pond samples collected between February 1995 and September 1996. The principal objective of the study was to determine the effect of refilling of Par Pond following repair of the dam on the phytoplankton community. Algal blooms are often responsible for fish kills and other detrimental effects in ponds and lakes, and it was postulated that decaying vegetation from formerly exposed sediments might trigger algal blooms that could result in fish kills in Par Pond following the refill. Sporadic algal blooms involving blue-green algae were detected, especially during the summer of 1996. However, the data derived from the study demonstrates that overall, the refilling effort caused no significant negative impact to the pond attributable to phytoplankton dynamics

  16. Par Pond phytoplankton in association with refilling of the pond: Final Report for sampling from February 1995 -- September 1996

    Energy Technology Data Exchange (ETDEWEB)

    Wilde, E.W.; Johnson, M.A.; Cody, W.C.

    1996-12-31

    This report describes the results of phytoplankton analyses from Par Pond samples collected between February 1995 and September 1996. The principal objective of the study was to determine the effect of refilling of Par Pond following repair of the dam on the phytoplankton community. Algal blooms are often responsible for fish kills and other detrimental effects in ponds and lakes, and it was postulated that decaying vegetation from formerly exposed sediments might trigger algal blooms that could result in fish kills in Par Pond following the refill. Sporadic algal blooms involving blue-green algae were detected, especially during the summer of 1996. However, the data derived from the study demonstrates that overall, the refilling effort caused no significant negative impact to the pond attributable to phytoplankton dynamics.

  17. Results of submerged sediment core sampling and analysis on Par Pond, Pond C, and L Lake: July 1995

    International Nuclear Information System (INIS)

    Koch, J.W. II; Martin, F.D.; Friday, G.P.

    1996-06-01

    Sediment cores from shallow and deep water locations in Par Pond, Pond C, and L Lake were collected and analyzed in 1995 for radioactive and nonradioactive constituents. This core analysis was conducted to develop a defensible characterization of contaminants found in the sediments of Par Pond, Pond C, and L Lake. Mercury was the only nonradiological constituent with a nonestimated quantity that was detected above the U.S Environmental Protection Agency Region IV potential contaminants of concern screening criteria. It was detected at a depth of 0.3--0.6 meters (1.0--2.0 feet) at one location in L Lake. Cesium-137, promethium-146, plutonium-238, and zirconium-95 had significantly higher concentrations in Par Pond sediments than in sediments from the reference sites. Cobalt-60, cesium-137, plutonium-238, plutonium-239/240, and strontium-90 had significantly higher concentrations in L-Lake sediments than sediments from the reference sites

  18. Data validation report for the 100-D Ponds Operable Unit: 100-D ponds sampling

    International Nuclear Information System (INIS)

    Stankovich, M.T.

    1994-01-01

    Westinghouse-Hanford has requested that 100 percent of the Sample Delivery Groups be validated for the 100-D Ponds Operable Unit Sampling Investigation. Therefore the data from the chemical analysis of all 30 samples from this sampling event and their related quality assurance samples were reviewed and validated to verify that reported sample results were of sufficient quality to support decisions regarding remedial actions performed at this site

  19. Sea Salt vs. Table Salt: What's the Difference?

    Science.gov (United States)

    ... and healthy eating What's the difference between sea salt and table salt? Answers from Katherine Zeratsky, R.D., L.D. The main differences between sea salt and table salt are in their taste, texture ...

  20. Low-salt diet

    Science.gov (United States)

    Low-sodium diet; Salt restriction ... control many functions. Too much sodium in your diet can be bad for you. For most people, ... you limit salt. Try to eat a balanced diet. Buy fresh vegetables and fruits whenever possible. They ...

  1. Molten salt breeder reactor

    International Nuclear Information System (INIS)

    1977-01-01

    MSBR Study Group formed in October 1974 has studied molten salt breeder reactor and its various aspects. Usage of a molten salt fuel, extremely interesting as reactor chemistry, is a great feature to MSBR; there is no need for separate fuel making, reprocessing, waste storage facilities. The group studied the following, and these results are presented: molten salt technology, molten salt fuel chemistry and reprocessing, reactor characteristics, economy, reactor structural materials, etc. (Mori, K.)

  2. QUALITATIVE COMPOSITION OF PHYTOPLANKTONS IN DIFFERENTLY MANURED CARP PONDS

    Directory of Open Access Journals (Sweden)

    Ljubica Debeljak

    1997-04-01

    Full Text Available Researches on qualitative composition of phytoplanktons in differently manured fish-ponds "Jelas" were carried out in 1996. The carp fingerling from larve to its second month was nurtured in three fish-ponds (A,B,C with the plantation of larves of 1,000,000 ind.ha-1. Larves and carp fry were nurtured by trouvit and wheat flour. The fish-pond A was controlled but not manured; the fish-pond B was fertilized by the total of 200 kg.ha-1 NPK (15:15:15 and the fish-pond C was fertilized by the total of 75 l.ha-1 of UAN and 75 kg.l-1 of NP (12:52. All fish-ponds had similar water chemism. In the qualitative composition of phytoplanktons there were stated 93 kinds, members of systematic groups Cyanophyta (10%, Euglenophyta (16.2%, Pyrrophyta (2%, Chrysophyta (39.4% and Chlorophyta (32%. All fish-ponds had similar qualitative composition of phytoplanktons with the flora similarity quotient from 65.5% to 72%.

  3. Ecological behavior of plutonium and americium in a freshwater pond

    International Nuclear Information System (INIS)

    Emery, R.M.; Klopfer, D.C.; Garland, T.R.; Weimer, W.C.

    1976-01-01

    A plutonium (Pu) processing waste pond on the Hanford Reservation has been studied since mid-1973 to characterize the pond's limnology and determine the ecological behavior of transuranics in this ecosystem. This ultra-eutrophic pond has a water inflow rate of 10 m 3 /min, of which 95% leaves the pond by percolation. Macrophytes (mainly Potamogeton), algae (mainly Cladophora), benthic invertebrates (mainly dipteran and odonate larvae, hemipterans, amphipods and gastropods) and goldfish are the major biotic components of the system. Sediments appear to be the principal repository of Pu and Am, having mean concentrations for 238 Pu, 239 240 Pu and 241 Am of 112, 121 and 71 pCi/g (dry), respectively. Mean ratios of isotopes in the sediments are 0.85 for 238 Pu to 239 240 Pu, and 0.49 for 241 Am to 239 240 Pu. Algal floc (decomposing algal material) is the major concentrator of Pu and Am in the pond having mean concentrations of 238 Pu of 986 pCi/g, for 239 240 Pu of 615 pCi/g, and for 241 Am of 256 pCi/g. Watercress (Rorippa) had Pu levels about equal to those of the sediments, while dragonfly larvae (Libellula) and snails (Lymnaea) along with watercress had Am levels approximating those of the sediments. The remaining biota had Pu and Am levels which were generally well below those of the sediments.Preliminary in situ experiments indicate that goldfish reach an equilibrium level for Pu of about 15 pCi/g within a few days of exposure to the pond, after which they may remain active in the pond for many months without further accumulation. Experimental goldfish established ratios of 238 Pu to 239 240 Pu and 241 Am to 239 240 Pu that were similar to all other pond biota within 2 weeks of pond residence, suggesting a common source of biologically available Pu and Am

  4. Monthly and diurnal variations of limnological conditions of two ponds

    Directory of Open Access Journals (Sweden)

    AKM Fazlur Rahaman

    2017-06-01

    Full Text Available A study on monthly and diurnal changes of limnological conditions of two ponds was conducted in the Bangladesh Agricultural University campus, Mymensingh. The research work was performed by studying the limnological parameters such as transparency, temperature, dissolved oxygen, free carbon dioxide, pH, total alkalinity, nitrate-nitrogen, phosphate-phosphorus and plankton. Diurnal variations of physico-chemical factors were studied fortnightly at 6 hrs intervals at 6 a.m., 12 noon, 6 p.m. and 12 midnight. The amounts of transparency, dissolved oxygen and pH were higher during winter months than in summer months in both the ponds. Transparency, water temperature, total alkalinity, NO3-N and PO4-P were higher during summer months than in winter months in both the ponds. But the amount of free carbon dioxide was higher during winter months than in summer months in pond 1 while in pond 2 the amount of free carbon dioxide was higher during summer months than in winter months. Qualitative and quantitative monthly variations of phytoplankton and zooplankton were observed in both the ponds during the study period. The highest amount of dissolved oxygen, pH and total alkalinity were recorded at 6 p.m. and the lowest amounts of those at 6 a.m. in both the ponds. The highest temperature was recorded at 12 noon and the lowest at 12 midnight. But the highest amount of free carbon dioxide was recorded at 6 a.m. and the lowest at 6 p.m. in both the ponds. All the factors showed appreciable diel variations throughout the study period, which indicate that the ponds are productive.

  5. Groundwater impact assessment report for the 100-D Ponds

    International Nuclear Information System (INIS)

    Alexander, D.J.

    1993-07-01

    The 183-D Water Treatment Facility (WTF) discharges effluent to the 120-0-1 Ponds (100-D Ponds) located north of the 100-D Area perimeter fence. This report satisfies one of the requirements of the Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement) Milestone M-17-00B as agreed by the US Department of Energy, Washington State Department of Ecology, and the US Environmental Protection Agency. Tri-Party Agreement Milestone M-17-00B includes a requirement to assess impacts to groundwater from disposal of the 183-D WTF effluent to the 100-D Ponds. In addition, the 100-D Ponds are a Resource Conservation and Recovery Act of 1976 treatment, storage, and disposal facility covered by the 100-D Ponds Closure Plan (DOE-RL 1993a). There is evidence of groundwater contamination, primarily nitrate, tritium, and chromium, in the unconfined aquifer beneath the 100-D Area and 100 Areas in general. The contaminant plumes are area wide and are a result of past-practice reactor and disposal operations in the 100-D Area currently being investigated as part of the 100-DR-1 and 100-HR-3 Operable Units (DOE-RL 1992b, 1992a). Based on current effluent conditions, continued operation of the 100-D Ponds will not adversely affect the groundwater quality in the 100-D Area. Monitoring wells near the pond have slightly higher alkaline pH values than wells in the rest of the area. Concentrations of known contaminants in these wells are lower than ambient 100-D Area groundwater conditions and exhibit a localized dilution effect associated with discharges to the pond. Hydraulic impact to the local groundwater system from these discharges is minor. The groundwater monitoring well network for the 100-D Ponds is adequate

  6. An attempt to develop a protocol for revegetation of tailings pond at Jaduguda

    International Nuclear Information System (INIS)

    Jha, V.N.; Sethy, N.K.; Sahoo, S.K.; Tripathi, R.M.; Puranik, V.D.; Singh, V.K.

    2007-01-01

    Reclamation of uranium mill tailings is a global challenge. The mill tailings contain long-lived radionuclides and chemical additives required for the recovery of uranium. Plants can be used for consolidation of tailings and phytoremediation of contaminated soil. Present work is an attempt to develop a protocol for revegetation of used up tailings pond at Jaduguda. Brassica juncea species was used for growing vegetation over the modified tailings. It was observed that a combination of cultivation land soil, tailings and naturally digested sewage manure was effective medium for proper growth of the plants. The growth increased with increase in the quantity of sewage manure. Moreover, such combination supplemented with reagents like EDTA and chloride salt led to even better performance with respect to growth and reproduction. (author)

  7. A review of virus removal in wastewater treatment pond systems.

    Science.gov (United States)

    Verbyla, Matthew E; Mihelcic, James R

    2015-03-15

    Wastewater treatment ponds (lagoons) are one of the most common types of technologies used for wastewater management worldwide, especially in small cities and towns. They are particularly well-suited for systems where the effluent is reused for irrigation. However, the efficiency of virus removal in wastewater treatment pond systems is not very well understood. The main objective of this paper is to critically review the major findings related to virus removal in wastewater treatment pond systems and to statistically analyze results reported in the literature from field studies on virus removal in these systems. A comprehensive analysis of virus removal reported in the literature from 71 different wastewater treatment pond systems reveals only a weak to moderate correlation of virus removal with theoretical hydraulic retention time. On average, one log10 reduction of viruses was achieved for every 14.5-20.9 days of retention, but the 95th percentile value of the data analyzed was 54 days. The mechanisms responsible for virus removal in wastewater treatment ponds were also reviewed. One recent finding is that sedimentation may not be a significant virus removal mechanism in some wastewater ponds. Recent research has also revealed that direct and indirect sunlight-mediated mechanisms are not only dependent on pond water chemistry and optics, but also on the characteristics of the virus and its genome. MS2 coliphage is considered to be the best surrogate for studying sunlight disinfection in ponds. The interaction of viruses with particles, with other microorganisms, and with macroinvertebrates in wastewater treatment ponds has not been extensively studied. It is also unclear whether virus internalization by higher trophic-level organisms has a protective or a detrimental effect on virus viability and transport in pond systems. Similarly, the impact of virus-particle associations on sunlight disinfection in ponds is not well understood. Future research should focus on

  8. FROM PONDS TO MAN-MADE SEAS IN RUSSIA

    Directory of Open Access Journals (Sweden)

    Sergey Gorshkov

    2013-01-01

    Full Text Available Russia has more than 2200 reservoirs and large ponds. As time went by, ponds lost their importance in some aspects of human life, while newly created man-made seas impacted the nature and the people in two ways. The costs involved in designing, constructing, and operating the artificial seas, especially on the plains, have been too high to consider them as an undisputed achievement of the Soviet scientists transforming the nature. This paper discusses the problem of ponds and man-made seas in Russia.

  9. Report on the methylmercury situation in Par Pond. Final report

    International Nuclear Information System (INIS)

    Schindler, J.E.; Williams, D.J.; Alberts, J.J.

    1975-06-01

    Studies are reported on the methylation and accumulation of mercury in fish populations of the pond. Results showed that the majority of the mercury in the fish muscles was in the methyl mercury form. Very low concentrations of mercury were found in the pond sediments. Physiological methylation of the mercury could not be demonstrated by in vivo or in vitro techniques. Organic ligand methylation and reduction of the mercury was shown to be a possible mechanism to account for both the mercury distribution in the pond and the concentrations of methylmercury in the fish. Recommendations are made for remedial treatments to eliminate the mercury problem. (HLW)

  10. Limnological database for Par Pond: 1959 to 1980

    International Nuclear Information System (INIS)

    Tilly, L.J.

    1981-03-01

    A limnological database for Par Pond, a cooling reservoir for hot reactor effluent water at the Savannah River Plant, is described. The data are derived from a combination of research and monitoring efforts on Par Pond since 1959. The approximately 24,000-byte database provides water quality, primary productivity, and flow data from a number of different stations, depths, and times during the 22-year history of the Par Pond impoundment. The data have been organized to permit an interpretation of the effects of twenty years of cooling system operations on the structure and function of an aquatic ecosystem

  11. Greenhouse Gas Exchange in Small Arctic Thaw Ponds

    Science.gov (United States)

    Laurion, I.; Bégin, P. N.; Bouchard, F.; Preskienis, V.

    2014-12-01

    Arctic lakes and ponds can represent up to one quarter of the land surface in permafrost landscapes, particularly in lowland tundra landscapes characterized by ice wedge organic polygons. Thaw ponds can be defined as the aquatic ecosystems associated to thawing of organic soils, either resulting from active layer processes and located above low-center peat polygons (hereafter low-center polygonal or LCP ponds), or resulting from thermokarst slumping above melting ice wedges linked to the accelerated degradation of permafrost (hereafter ice-wedge trough or IWT ponds). These ponds can merge together forming larger water bodies, but with relatively stable shores (hereafter merged polygonal or MPG ponds), and with limnological characteristics similar to LCP ponds. These aquatic systems are very small and shallow, and present a different physical structure than the larger thermokarst lakes, generated after years of development and land subsidence. In a glacier valley on Bylot Island, Nunavut, Canada, thermokarst and kettle lakes together represent 29% of the aquatic area, with a thermal profile resembling those of more standard arctic lakes (mixed epilimnion). The IWT ponds (44% of the area) are stratified for a large fraction of the summer despite their shallowness, while LCP and MPG ponds (27% of the area) show a more homogeneous water column. This will affect gas exchange in these diverse aquatic systems, in addition to their unique microbiota and organic carbon lability that control the production and consumption rates of greenhouse gases. The stratification in IWT ponds generates hypoxic conditions at the bottom, and together with the larger availability of organic carbon, stimulates methanogenesis and limits the mitigating action of methanotrophs. Overall, thaw ponds are largely supersaturated in methane, with IWT ponds dominating the emissions in this landscape (92% of total aquatic emissions estimated for the same valley), and they present large variations in

  12. Role of rainwater induced subsurface flow in water-level dynamics and thermoerosion of shallow thermokarst ponds on the Northeastern Qinghai-Tibet Plateau

    Science.gov (United States)

    Pan, X.; Yu, Q.; You, Y.

    2014-12-01

    Understanding hydrological and thermal regimes of thermokarst lakes is of great importance for predicting their responses to climate change. However, mechanism of water-level dynamics and associated thermal effects on thermoerosion of thermokarst lakes are still not well understood on the Qinghai-Tibet Plateau (QTP). In this study, we investigate two typical shallow thermokarst ponds (namely small lakes) in a warm permafrost region with thick active layer on the northeastern QTP through quantifying water budget. Results demonstrate that, rainfall induced subsurface lateral flow dominates pond water-level regime. Annual variation of pond water-level relies on areal water budget of surrounding active layer, particularly the high variable of precipitation. Besides, it is worth noting the extraordinary warming during the late ice-cover period, because marked air gap between upper ice-cover and underlying water, led by the upward thawing of thick ice-cover, might result in greenhouse-like condition due to the unique weather that strong solar radiation and little snowpack. This hydrological mechanism also exerts evident impacts on thermal regime and thermoerosion of the shallow thermokarst ponds, and they are closely related to retreat of thermokarst pondshore and underlying permafrost degradation. These findings imply a localized model addressing the unique hydrological and thermal regimes of thermokarst lakes would be essential to study the evolution of these shallow rainwater dominated thermokarst ponds on the QTP.

  13. Geohydrology and limnology of Walden Pond, Concord, Massachusetts

    Science.gov (United States)

    Colman, John A.; Friesz, Paul J.

    2001-01-01

    The trophic ecology and ground-water contributing area of Walden Pond, in Concord and Lincoln, Mass., were investigated by the U.S. Geological Survey in cooperation with the Massachusetts Department of Environmental Management from April 1997 to July 2000. Bathymetric investigation indicated that Walden Pond (24.88 hectares), a glacial kettle-hole lake with no surface inlet or outlet, has three deep areas. The maximum depth (30.5 meters) essentially was unchanged from measurements made by Henry David Thoreau in 1846. The groundwater contributing area (621,000 square meters) to Walden Pond was determined from water-table contours in areas of stratified glacial deposits and from land-surface contours in areas of bedrock highs. Walden Pond is a flow-through lake: Walden Pond gains water from the aquifer along its eastern perimeter and loses water to the aquifer along its western perimeter. Walden Pond contributing area also includes Goose Pond and its contributing area. A water budget calculated for Walden Pond, expressed as depth of water over the lake surface, indicated that 45 percent of the inflow to the lake was from precipitation (1.215 meters per year) and 55 percent from ground water (1.47 meters per year). The groundwater inflow estimate was based on the average of two different approaches including an isotope mass-balance approach. Evaporation accounted for 26 percent of the outflow from the lake (0.71 meters per year) whereas lake-water seepage to the groundwater system contributed 74 percent of the outflow (1.97 meters per year). The water-residence time of Walden Pond is approximately 5 years. Potential point sources of nutrients to ground water, the Concord municipal landfill and a trailer park, were determined to be outside the Walden Pond groundwater contributing area. A third source, the septic leach field for the Walden Pond State Reservation facilities, was within the groundwater contributing area. Nutrient budgets for the lake indicated that

  14. Elimination and accumulation of polycyclic aromatic hydrocarbons (PAHs) in urban stormwater wet detention ponds

    DEFF Research Database (Denmark)

    Istenič, Daria; Arias, Carlos Alberto; Matamoros, Victor

    2011-01-01

    The concentrations of polycyclic aromatic hydrocarbons (PAHs) in water and sediments of seven wet detention ponds receiving urban stormwater were investigated. The ponds comprised traditional wet detention ponds with a permanent wet volume and a storage volume as well as ponds that were expanded...

  15. Crossing the Salt Barrier

    Indian Academy of Sciences (India)

    either the sea or freshwater (rivers, lakes, ponds, etc.), or brackish ... by use of the term osmol (Osm) where, for ... much lower than EE and a fresh water fish lives in an environment where just ..... than prophyropsin, vision is greatly improved.

  16. Bacterial flora of pond reared Penaeus indicus (Milne Edwards)

    Digital Repository Service at National Institute of Oceanography (India)

    Singh, I.S.B.; Lakshmanaperumalsamy, P.; Chandramohan, D.

    The population size, generic diversity and potential to produce hydrolytic enzymes of heterotrophic bacteria associated with pond reared Penaeus indicus was worked out following standard bacteriological procedures. Chitinoclastic vibrios were found...

  17. The Effects of Species Interaction and Pond Stocking Density on ...

    African Journals Online (AJOL)

    Burchell) and Heterobranchus bidorsalis (Geoffrey Saint-Hilaire) and pond stocking density on the culture of tilapia species which display different parental care strategies. In the presence of catfishes, the maternal mouth-brooder O. niloticus ...

  18. MALLARD REPRODUCTIVE TESTING IN A POND ENVIRONMENT: A PRELIMINARY STUDY

    Science.gov (United States)

    A 2-year preliminary study was conducted on mallard ducks to determine the feasibility of using outdoor pond enclosures for reproductive studies and to evaluate the effects of the insecticide chlorpyrifos on mallard reproduction. No significant reproductive effects were observed ...

  19. Supraglacial Ponds Regulate Runoff From Himalayan Debris-Covered Glaciers

    Science.gov (United States)

    Irvine-Fynn, Tristram D. L.; Porter, Philip R.; Rowan, Ann V.; Quincey, Duncan J.; Gibson, Morgan J.; Bridge, Jonathan W.; Watson, C. Scott; Hubbard, Alun; Glasser, Neil F.

    2017-12-01

    Meltwater and runoff from glaciers in High Mountain Asia is a vital freshwater resource for one-fifth of the Earth's population. Between 13% and 36% of the region's glacierized areas exhibit surface debris cover and associated supraglacial ponds whose hydrological buffering roles remain unconstrained. We present a high-resolution meltwater hydrograph from the extensively debris-covered Khumbu Glacier, Nepal, spanning a 7 month period in 2014. Supraglacial ponds and accompanying debris cover modulate proglacial discharge by acting as transient and evolving reservoirs. Diurnally, the supraglacial pond system may store >23% of observed mean daily discharge, with mean recession constants ranging from 31 to 108 h. Given projections of increased debris cover and supraglacial pond extent across High Mountain Asia, we conclude that runoff regimes may become progressively buffered by the presence of supraglacial reservoirs. Incorporation of these processes is critical to improve predictions of the region's freshwater resource availability and cascading environmental effects downstream.

  20. Western Pond Turtle Observations - Region 1 [ds313

    Data.gov (United States)

    California Natural Resource Agency — This dataset was developed in an effort to compile Western Pond Turtle (Clemmys marmorata) observations in CDFG Region 1. Steve Burton (CDFG Staff Environmental...

  1. VT Northern Forest Lands - Lakes and Ponds area polygons

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) These data identify shorelines of lakes and ponds ten (10) acres and larger. The shorelines are classified according to their development status....

  2. Removal of Heavy Metals and PAH in Highway Detention Ponds

    DEFF Research Database (Denmark)

    Bentzen, Thomas Ruby; Larsen, Torben; Thorndahl, Søren Liedtke

    2005-01-01

    , which has been designed according to standard design criteria for several decades. The study will focus on heavy metals (Cd, Cr, Cu, Pb and Zn) and polyaromatic hydrocarbons (PAH). The long-term simulation of input of flow and pollution to the ponds will be a hind cast based on time series of historical......The paper presents some of the first results from a study of the removal of pollutants in highway detention ponds in Denmark. The objective of the study is to set up a procedure for long-term modelling of discharges of pollutants to the environment from the many Danish highway detention ponds...... rainfalls. The modelling will take place in a special version of the MIKE URBAN. The modelling is calibrated and validated on measurements from selected highway catchments. The removal of pollutants in the ponds is studied by local measurements in combination with CFD modelling using the MIKE 21 and MIKE 3...

  3. Approximate computation of hydrothermal conditions of nuclear reactor spray ponds

    International Nuclear Information System (INIS)

    Yarkho, A.A.; Borshchev, V.A.

    1990-01-01

    An algorithm is presented for determining the evaporation numbers of nuclear reactor spray ponds which provide necessary reactor cooling during its normal operation under given meteorological conditions with account of restrictions on the cooled water temperature at the reactor entrance

  4. Beyond Historical Fiction: Speare's "The Witch of Blackbird Pond."

    Science.gov (United States)

    Thuente, Mary Helen

    1985-01-01

    Reviews "The Witch of Blackbird Pond" by E. Speare to show how the full narrative power of the novel derives from the author's successful integration of two separate narrative genres: historical fiction and the folktale. (EL)

  5. Algoflora of oxbow ponds transformed with beavers' activity

    OpenAIRE

    Макаревич, Т. А.; Белоус, В. В.; Гурчунова, Т. А.

    2016-01-01

    Algoflora of oxbow ponds transformed with beaver activity is characterized by high species richness and taxonomic diversity, high periphyton importance in the formation of algoflora compared with phytoplankton, prevalence of periphytic and benthic algae over typically planktonic forms

  6. VT Northern Forest Lands - Lakes and Ponds boundary lines

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) These data identify shorelines of lakes and ponds ten (10) acres and larger. The shorelines are classified according to their development status....

  7. The Belmont Valley integrated algae pond system in retrospect

    African Journals Online (AJOL)

    2013-03-26

    Mar 26, 2013 ... ness amongst all stakeholders including the public at large, the three spheres of ...... (2011) Algae biofuel from wastewater treatment high rate algal ponds. .... and OELMÜLLER R (2002) Photosynthetic electron transport.

  8. Can terraced pond wetland systems improve urban watershed water quality?

    Science.gov (United States)

    Li, S.; Ho, M.; Flanagan, N. E.; Richardson, C. J.

    2017-12-01

    Properly built constructed wetlands are a more economic and efficient way of wastewater treatment compared with traditional methods, although their mechanisms are far from completely understood. As part of the Stream and Wetland Assessment Management Park (SWAMP), which is aimed to improve the water quality of downstream and thereby enhance watershed ecosystem services, a terraced three-pond wetland system was created near Duke University in 2014. This project is expected to promote the retention and settling of pollutants and sediment before runoffs enter downstream flow. The goal of this study is to examine: (1) whether a terraced pond wetland system improves water quality, during both baseline (low flow) and storm events (high flow), which increases pollutant inputs; and (2) how this system functions to remove pollutants, namely what components of this system (plant, soil or water) increase or decrease the level of pollutants. By analyzing a dataset consisting of more than four-year monthly samplings from Pond 1 (first pond in the system) and Pond 3 (last pond in the system), we found that the pond system has reduced total suspended solids (TSS) but only when elevated inputs occur. Dissolved oxygen (DO) is closely related to temperature and macrophytes growth; whereas acidity (pH), total nitrogen (TN), and total phosphorus (TP) did not show retention in the early stages of the system development. This system reaches its optimum for reducing TSS at the second pond, but the third pond has important effects on DO, pH, TN and TP. A monitoring in 2017 shows this pond system significantly reduces TSS while increasing dissolved oxygen and neutralizing pH after a storm event; although greater variations incurred within the system as time progresses after storm, overall retention function remained valid. Retention of the pollutants is primarily accomplished by the settling process, which occurs in stilled waterbody of the ponds and by the filtration of macrophytes. We

  9. Steam gasification of plant biomass using molten carbonate salts

    International Nuclear Information System (INIS)

    Hathaway, Brandon J.; Honda, Masanori; Kittelson, David B.; Davidson, Jane H.

    2013-01-01

    This paper explores the use of molten alkali-carbonate salts as a reaction and heat transfer medium for steam gasification of plant biomass with the objectives of enhanced heat transfer, faster kinetics, and increased thermal capacitance compared to gasification in an inert gas. The intended application is a solar process in which concentrated solar radiation is the sole source of heat to drive the endothermic production of synthesis gas. The benefits of gasification in a molten ternary blend of lithium, potassium, and sodium carbonate salts is demonstrated for cellulose, switchgrass, a blend of perennial plants, and corn stover through measurements of reaction rate and product composition in an electrically heated reactor. The feedstocks are gasified with steam at 1200 K in argon and in the molten salt. The use of molten salt increases the total useful syngas production by up to 25%, and increases the reactivity index by as much as 490%. Secondary products, in the form of condensable tar, are reduced by 77%. -- Highlights: ► The presence of molten salt increases the rate of gasification by up to 600%. ► Reaction rates across various feedstocks are more uniform with salt present. ► Useful syngas yield is increased by up to 30% when salt is present. ► Secondary production of liquid tars are reduced by 77% when salt is present.

  10. Convergent Diversity and Trait Composition in Temporary Streams and Ponds

    Science.gov (United States)

    2016-05-19

    ilarities ( PERMANOVA , Adonis function) test on the traits × site matrix. Adonis can be used to test for similar means (centroids) of groups. A...al. 2006). Third, we tested for differences in mean trait distanc- es using PERMANOVA (adonis function) on the distance matrices ran with 999...P = 0.001; ponds: P = 0.015). Mean taxonomic dissimilarities showed significant differences between ponds and streams ( PERMANOVA : R2 = 0.40, P

  11. Homestead fish pond and the environment in Nigeria

    OpenAIRE

    Okaeme, A.N.

    1999-01-01

    Homestead fish culture is a recent innovation for mass production of fish at backyard in Nigeria. The processes of pond construction often have resulted in soil disturbances, vegetation losses, and creation of new aquatic environment. The paper discusses homestead ponds in Nigeria, their potential impact on the environment which includes erosion, over flooding, pest and disease, accident risk, undesired fossil fuel production, vegetation destruction and fish genetic conservation, strategies f...

  12. Seasonal dynamics of fish assemblage in a pond canal

    Czech Academy of Sciences Publication Activity Database

    Musil, J.; Adámek, Zdeněk; Baranyi, Ch.

    2007-01-01

    Roč. 15, č. 3-4 (2007), s. 217-226 ISSN 0967-6120. [New Challenges in Pond Aquaculture. České Budějovice, 26.04.2005-28.04.2005] Institutional research plan: CEZ:AV0Z60930519 Keywords : fish assemblage * pond canal * species richness * seasonal dynamics * alien species Subject RIV: GL - Fishing Impact factor: 0.828, year: 2007

  13. Seasonality of dipteran-mediated methylmercury flux from ponds.

    Science.gov (United States)

    Chumchal, Matthew M; Drenner, Ray W; Hall, MacGregor N; Polk, D Kirkland; Williams, Edward B; Ortega-Rodriguez, Celeste L; Kennedy, James H

    2018-03-12

    Methylmercury (MeHg) is an aquatic contaminant that can be transferred to terrestrial predators by emergent aquatic insects. We assessed the effects of month and pond permanence on dipteran-mediated MeHg flux (calculated as emergent dipteran biomass × dipteran MeHg concentration) in 10 experimental ponds. Emergent dipterans were collected weekly from permanent ponds with bluegill (Lepomis macrochirus; n = 5) and semipermanent ponds without fish (n = 5) over a 7-mo period (February-August, 2015). We detected a significant effect of month on MeHg flux from 6 dipteran taxa and aggregate MeHg flux, with the highest MeHg flux from herbivorous/detritivorous chironomid midges and predatory midges in March; biting midges, phantom midges and herbivorous/detritivorous orthoclad midges in April; and mosquitoes in August. Aggregate dipteran-mediated MeHg flux peaked in April and then declined throughout the remainder of the summer. We did not detect a significant main effect of pond permanence or a significant month × pond permanence interaction effect on MeHg flux for any of the taxa examined in the present study or for aggregate MeHg flux. Given their ubiquity in aquatic systems and their importance in food webs at the land-water interface, dipterans are important taxa that should not be overlooked as a part of the Hg cycle. Environ Toxicol Chem 2018;9999:1-6. © 2018 SETAC. © 2018 SETAC.

  14. Distribution of transuranic elements in a freshwater pond ecosystem

    International Nuclear Information System (INIS)

    Emery, R.M.; Klopfer, D.C.

    1975-05-01

    Preliminary results are reported from a study initiated on the Hanford Reservation concerning the ecological behavior of 238 Pu, 239 Pu, 240 Pu, and 241 Am in a freshwater environment. This study involves a waste pond which has been receiving Pu processing wastes for about 30 years. The pond has a sufficiently established ecosystem to provide an excellent location for limnological characterization. In addition, the ecological distribution of Pu and Am was investigated. The pond is also highly enriched with nutrients, thus supporting a high level of algal and macrophyte production. Seston (30 percent diatoms) appears to be the principal concentrators of Pu transuranics in the pond system. The major sink for Pu and Am in this system is the sediments. Organic floc, overlaying the pond sediments, is also a major concentrator of transuranics in this system []Aside from the seston and floc, no other ecological components of the pond appear to have concentrations significantly greater than those of the sediment. Dragonfly, larvae, watercress, and snails show concentrations which approximate those of the sediments but nearly all other food web components have levels of Pu and Am which are lower than those of the sediments, thus, Pu and Am seem to be relatively immobile in the aquatic ecosystem. (CH)

  15. Enhancing Ecoefficiency in Shrimp Farming through Interconnected Ponds

    Directory of Open Access Journals (Sweden)

    Ramón Héctor Barraza-Guardado

    2015-01-01

    Full Text Available The future development of shrimp farming needs to improve its ecoefficiency. The purpose of this study was to evaluate water quality, flows, and nitrogen balance and production parameters on a farm with interconnected pond design to improve the efficiency of the semi-intensive culture of Litopenaeus vannamei ponds. The study was conducted in 21 commercial culture ponds during 180 days at densities of 30–35 ind m−2 and daily water exchange <2%. Our study provides evidence that by interconnecting ponds nutrient recycling is favored by promoting the growth of primary producers of the pond as chlorophyll a. Based on the mass balance and flow of nutrients this culture system reduces the flow of solid, particulate organic matter, and nitrogen compounds to the environment and significantly increases the efficiency of water (5 to 6.5 m3 kg−1 cycle−1, when compared with traditional culture systems. With this culture system it is possible to recover up to 34% of the total nitrogen entering the system, with production in excess of 4,000 kg ha−1 shrimp. We believe that the production system with interconnected ponds is a technically feasible model to improve ecoefficiency production of shrimp farming.

  16. Continuous Hydrologic and Water Quality Monitoring of Vernal Ponds.

    Science.gov (United States)

    Mina, Odette; Gall, Heather E; Chandler, Joseph W; Harper, Jeremy; Taylor, Malcolm

    2017-11-13

    Vernal ponds, also referred to as vernal pools, provide critical ecosystem services and habitat for a variety of threatened and endangered species. However, they are vulnerable parts of the landscapes that are often poorly understood and understudied. Land use and management practices, as well as climate change are thought to be a contribution to the global amphibian decline. However, more research is needed to understand the extent of these impacts. Here, we present methodology for characterizing a vernal pond's morphology and detail a monitoring station that can be used to collect water quantity and quality data over the duration of a vernal pond's hydroperiod. We provide methodology for how to conduct field surveys to characterize the morphology and develop stage-storage curves for a vernal pond. Additionally, we provide methodology for monitoring the water level, temperature, pH, oxidation-reduction potential, dissolved oxygen, and electrical conductivity of water in a vernal pond, as well as monitoring rainfall data. This information can be used to better quantify the ecosystem services that vernal ponds provide and the impacts of anthropogenic activities on their ability to provide these services.

  17. Modeling a ponded infiltration experiment at Yucca Mountain, NV

    International Nuclear Information System (INIS)

    Hudson, D.B.; Guertal, W.R.; Flint, A.L.

    1994-01-01

    Yucca Mountain, Nevada is being evaluated as a potential site for a geologic repository for high level radioactive waste. As part of the site characterization activities at Yucca Mountain, a field-scale ponded infiltration experiment was done to help characterize the hydraulic and infiltration properties of a layered dessert alluvium deposit. Calcium carbonate accumulation and cementation, heterogeneous layered profiles, high evapotranspiration, low precipitation, and rocky soil make the surface difficult to characterize.The effects of the strong morphological horizonation on the infiltration processes, the suitability of measured hydraulic properties, and the usefulness of ponded infiltration experiments in site characterization work were of interest. One-dimensional and two-dimensional radial flow numerical models were used to help interpret the results of the ponding experiment. The objective of this study was to evaluate the results of a ponded infiltration experiment done around borehole UE25 UZN number-sign 85 (N85) at Yucca Mountain, NV. The effects of morphological horizons on the infiltration processes, lateral flow, and measured soil hydaulic properties were studied. The evaluation was done by numerically modeling the results of a field ponded infiltration experiment. A comparison the experimental results and the modeled results was used to qualitatively indicate the degree to which infiltration processes and the hydaulic properties are understood. Results of the field characterization, soil characterization, borehole geophysics, and the ponding experiment are presented in a companion paper

  18. 2101-M pond closure plan. Volume 1, Revision 2

    Energy Technology Data Exchange (ETDEWEB)

    Izatt, R. D.; Lerch, R. E.

    1993-06-01

    This document describes activities for the closure of a surface impoundment (2101-M Pond) at the Hanford Site. The 2101-H Pond was initially constructed in 1953 to serve as a drainage collection area for the 2101-H Building. (Until the Basalt Waste Isolation Project (BWIP) Laboratory was constructed in the 2101-M Building in 1979--1981, the only source contributing discharge to the pond was condensate water from the 2101-H Building heating, ventilation, and air conditioning (HVAC) system. The drains for the BWIP Laboratory rooms were plumbed into a 4-in., cast-iron, low-pressure drain pipe that carries waste water from the HVAC system to the pond. During the active life of the BWIP Laboratory, solutions of dissolved barium in groundwater samples were discharged to the 2101-M Pond via the laboratory drains. As a result of the discharges, a Part A permit application was initially submitted to the Washington State Department of Ecology (Ecology) in August 1986 which designates the 2101-M Pond as a surface impoundment.

  19. Sediment remediation of the Hespeler Mill Pond, Cambridge, Ontario

    Energy Technology Data Exchange (ETDEWEB)

    Angeloni, D.; Eby, M.; Jarvis, S.; Martin, P. [Univ. of Guelph, School of Engineering, Guelph, Ontario (Canada)]. E-mail: danielle.angeloni@earthtech.ca

    2002-06-15

    'Full text:' Low dissolved oxygen levels and large accumulated sediment remediation alternatives were examined to assemble the Hespeler Mill Pond, Cambridge (HMP) into a healthier and more desirable recreational area in the City of Cambridge. The theory that a large amount of sediment has been deposited into the HMP from the Speed River upstream over a number of years predicts the depressed oxygen levels, high nutrient-loading rates and the odour problems in the summer months. The initial phase in the remediation plan for this project involved extensive background research and investigation. The focus was on determining the characteristics of the sediment and the history of the pond, to ultimately decide if the sediment was the source of the issues. Dissolved oxygen field tests and sediment sampling were conducted to get information on the magnitude of the problem and the environmental hazards potentially present in the pond. The pond was modelled utilising the Streeter-Phelps oxygen-sag model to predict the oxygen deficit. Biochemical Oxygen Demand (BOD{sub 5}) testing was completed to determine the oxygen demand in the pond. These tests were conducted by using water samples obtained from various sample points at the pond. The proposed solution is a combined dredging and aeration approach. Mechanical dredging using a clamshell bucket and the installation of aerators is expected to solve the dissolved oxygen and water quality issues. (author)

  20. Geomembrane selection criteria for uranium tailings ponds

    International Nuclear Information System (INIS)

    Mitchell, D.H.; Cuello, R.

    1986-09-01

    The selection criteria, particularly those involving chemical compatibility, of geomembranes to be used in ponds at uranium mill operations are discussed. The principal functional criteria which a geomembrane must meet for this application are: (1) a specified service life and (2) low permeability. Chemical compatibility with the waste is essential in meeting these functional criteria. In two different types of aging tests using simulated acidic uranium mill waste, degradation of chemical and physical properties were examined in geomembranes of high-density polyethylene, polyvinyl chloride, and chlorosulfonated polyethylene. Compatibility tests according to the National Sanitation Foundation procedures are recommended to ascertain the stability of certain physical properties of the proposed geomembrane. Actual experience with a specific geomembrane in an identical application is probably the best method to assure compatibility; however, this experience is frequently not available. Experience with a geomembrane in similar applications is valuable in the selection process, however, small differences in either the geomembrane formulation or the waste composition may result in large differences in performance of the geomembrane. It is likely that many geomembranes have acceptable chemical stability for typical uranium mill applications, therefore, additional factors in the selection processes will include seaming characteristics, mechanical properties, site characteristics, and costs

  1. Integrated oil sands tailings pond water treatment

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Z. [Saskatchewan Research Council, Saskatoon, SK (Canada)

    2010-07-01

    This PowerPoint presentation discussed research currently being conducted to treat oil sands tailings pond water (TPW). The treatment of TPW is challenged by the high level of naphthenic acids (NAs), the slow settling rate of fine particulate materials, and the complex chemistry of the water. The treatment process consisted of bioflocculation, sludge blanket assisted clarification, ozonation, and oil sands coke assisted hybrid biodegradation. The aggregation and adsorption process bound small particles and cells together while also ensuring the passive uptake of pollutants using microbial masses. The mixed liquor then passed through a sludge blanket to ensure enhanced particle capture. An ozonation process was used to increase the biodegradability of the TPW as well as to increase the biodegradability of the residual NAs after ozonation. The process used a hybrid bioreactor that consisted of both suspended and fixed microbial communities. The coke served as a biofilm carrier for the waste. Further studies are being conducted to investigate the efficiency and capability of the process. tabs., figs.

  2. Lowering resistance of the Hoyle Pond Mine

    Energy Technology Data Exchange (ETDEWEB)

    Desjardins, M. [Goldcorp Canada Ltd., Porcupine Gold Mines, Hoyle Pond Mine, Timmins, ON (Canada)

    2010-07-01

    The Hoyle Pond underground mine is located in the Porcupine Gold Camp, east of Timmins, Ontario. Various mining methods are used to excavate the gold, each with different ventilation requirements in terms of layout and volume. The mine was originally designed as a shallow mine but is planning to reach a depth of 2500 m. This paper described the events that lead to the high system pressures encountered at the mine, and the measures taken to reduce them. New surface fans and a new fresh air raise (FAR) were commissioned in 2005. The old FAR had to be sealed as soon as the new fans were in place in order to prevent short-circuiting. As a result, the mine resistance curve steepened considerably. The total pressure at the fan increased from 1500 Pa to 3000 Pa. As such, only 1 surface fan could operate at any give time, providing only half the possible volume of air. The challenge was to reduce the mine's resistance while getting the desired volume of air down to to the mining faces at depth. The solutions were to install booster fans and initiate a raise-bore program that would link the 450 m level to 900 m level. These measures twinned the existing fresh air circuit and resulted in a lowering of the overall mine resistance curve. 1 ref., 9 figs.

  3. Comparison of hydraulics and particle removal efficiencies in a mixed cell raceway and Burrows pond rearing system

    Science.gov (United States)

    Moffitt, Christine M.

    2016-01-01

    We compared the hydrodynamics of replicate experimental mixed cell and replicate standard Burrows pond rearing systems at the Dworshak National Fish Hatchery, ID, in an effort to identify methods for improved solids removal. We measured and compared the hydraulic residence time, particle removal efficiency, and measures of velocity using several tools. Computational fluid dynamics was used first to characterize hydraulics in the proposed retrofit that included removal of the traditional Burrows pond dividing wall and establishment of four counter rotating cells with appropriate drains and inlet water jets. Hydraulic residence time was subsequently established in the four full scale test tanks using measures of conductivity of a salt tracer introduced into the systems both with and without fish present. Vertical and horizontal velocities were also measured with acoustic Doppler velocimetry in transects across each of the rearing systems. Finally, we introduced ABS sinking beads that simulated fish solids then followed the kinetics of their removal via the drains to establish relative purge rates. The mixed cell raceway provided higher mean velocities and a more uniform velocity distribution than did the Burrows pond. Vectors revealed well-defined, counter-rotating cells in the mixed cell raceway, and were likely contributing factors in achieving a relatively high particle removal efficiency-88.6% versus 8.0% during the test period. We speculate retrofits of rearing ponds to mixed cell systems will improve both the rearing environments for the fish and solids removal, improving the efficiency and bio-security of fish culture. We recommend further testing in hatchery production trials to evaluate fish physiology and growth.

  4. Submarine Salt Karst Terrains

    Directory of Open Access Journals (Sweden)

    Nico Augustin

    2016-06-01

    Full Text Available Karst terrains that develop in bodies of rock salt (taken as mainly of halite, NaCl are special not only for developing in one of the most soluble of all rocks, but also for developing in one of the weakest rocks. Salt is so weak that many surface-piercing salt diapirs extrude slow fountains of salt that that gravity spread downslope over deserts on land and over sea floors. Salt fountains in the deserts of Iran are usually so dry that they flow at only a few cm/yr but the few rain storms a decade so soak and weaken them that they surge at dm/day for a few days. We illustrate the only case where the rates at which different parts of one of the many tens of subaerial salt karst terrains in Iran flows downslope constrains the rates at which its subaerial salt karst terrains form. Normal seawater is only 10% saturated in NaCl. It should therefore be sufficiently aggressive to erode karst terrains into exposures of salt on the thousands of known submarine salt extrusions that have flowed or are still flowing over the floors of hundreds of submarine basins worldwide. However, we know of no attempt to constrain the processes that form submarine salt karst terrains on any of these of submarine salt extrusions. As on land, many potential submarine karst terrains are cloaked by clastic and pelagic sediments that are often hundreds of m thick. Nevertheless, detailed geophysical and bathymetric surveys have already mapped likely submarine salt karst terrains in at least the Gulf of Mexico, and the Red Sea. New images of these two areas are offered as clear evidence of submarine salt dissolution due to sinking or rising aggressive fluids. We suggest that repeated 3D surveys of distinctive features (± fixed seismic reflectors of such terrains could measure any downslope salt flow and thus offer an exceptional opportunity to constrain the rates at which submarine salt karst terrains develop. Such rates are of interest to all salt tectonicians and the many

  5. South Bay Salt Pond Restoration Project: Planning Phase at Southern Eden Landing

    Science.gov (United States)

    This project will complete the design and permits to restore 1,300 acres of tidal wetlands, provide 3.5 miles shoreline protection, and accelerate wetlands restoration at the Eden Landing Ecological Reserve.

  6. A history of salt.

    Science.gov (United States)

    Cirillo, M; Capasso, G; Di Leo, V A; De Santo, N G

    1994-01-01

    The medical history of salt begins in ancient times and is closely related to different aspects of human history. Salt may be extracted from sea water, mineral deposits, surface encrustations, saline lakes and brine springs. In many inland areas, wood was used as a fuel source for evaporation of brine and this practice led to major deafforestation in central Europe. Salt played a central role in the economies of many regions, and is often reflected in place names. Salt was also used as a basis for population censuses and taxation, and salt monopolies were practised in many states. Salt was sometimes implicated in the outbreak of conflict, e.g. the French Revolution and the Indian War of Independence. Salt has also been invested with many cultural and religious meanings, from the ancient Egyptians to the Middle Ages. Man's innate appetite for salt may be related to his evolution from predominantly vegetarian anthropoids, and it is noteworthy that those people who live mainly on protein and milk or who drink salty water do not generally salt their food, whereas those who live mainly on vegetables, rice and cereals use much more salt. Medicinal use tended to emphasize the positive aspects of salt, e.g. prevention of putrefaction, reduction of tissue swelling, treatment of diarrhea. Evidence was also available to ancient peoples of its relationship to fertility, particularly in domestic animals. The history of salt thus represents a unique example for studying the impact of a widely used dietary substance on different important aspects of man's life, including medical philosophy.

  7. Solar Indices - Solar Flares

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  8. Solar Indices - Solar Ultraviolet

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  9. Solar Indices - Solar Corona

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  10. Solar Indices - Solar Irradiance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  11. Advancement in solar evaporation techniques for volume reduction of chemical effluents

    Energy Technology Data Exchange (ETDEWEB)

    Parakasamurthy, K S [Nuclear Fuel Complex, Hyderabad (India); Pande, D P [Process Engineering and Systems Development Division, Bhabha Atomic Research Centre, Mumbai (India)

    1994-06-01

    A typical example of advancement of a unit operation for the given requirement is described. The solar evaporation ponds (SEP) have technical and economic advantages compared to other evaporation methods for concentrating chemical effluents. The operation of SEP is strongly dependent on the environmental and site conditions. Tropical conditions with high solar incidence, good wind speed along with hot and dry weather provide suitable climate for efficient operation of solar evaporation ponds. The particular site selected for the ponds at Nuclear Fuel Complex (NFC) has a rocky terrain with murrum over sheet with very low water table and small velocity of groundwater. During the past twenty five years extensive theoretical and experimental investigations have been carried out for advancement of solar evaporation technique. (author). 7 refs.

  12. Advancement in solar evaporation techniques for volume reduction of chemical effluents

    International Nuclear Information System (INIS)

    Parakasamurthy, K.S.; Pande, D.P.

    1994-01-01

    A typical example of advancement of a unit operation for the given requirement is described. The solar evaporation ponds (SEP) have technical and economic advantages compared to other evaporation methods for concentrating chemical effluents. The operation of SEP is strongly dependent on the environmental and site conditions. Tropical conditions with high solar incidence, good wind speed along with hot and dry weather provide suitable climate for efficient operation of solar evaporation ponds. The particular site selected for the ponds at Nuclear Fuel Complex (NFC) has a rocky terrain with murrum over sheet with very low water table and small velocity of groundwater. During the past twenty five years extensive theoretical and experimental investigations have been carried out for advancement of solar evaporation technique. (author)

  13. Worth its salt?

    Science.gov (United States)

    The idea that all underground salt deposits can serve as storage sites for toxic and nuclear waste does not always hold water—literally. According to Daniel Ronen and Brian Berkowitz of Israel's Weizmann Institute of Science and Yoseph Yechieli of the Geological Survey of Israel, some buried salt layers are in fact highly conductive of liquids, suggesting that wastes buried in their confines could easily leech into groundwater and nearby soil.When drilling three wells into a 10,000-year-old salt layer near the Dead Sea, the researchers found that groundwater had seeped into the layer and had absorbed some of its salt.

  14. Pond-aquifer flow and water availability in the vicinity of two coastal area seepage ponds, Glynn and Bulloch Counties, Georgia

    Science.gov (United States)

    Clarke, John S.; Rumman, Malek Abu

    2005-01-01

    Pond-aquifer flow and water availability at excavated seepage pond sites in Glynn County and in southern Bulloch County, Georgia, were evaluated to determine their potential as sources of water supply for irrigation. Excavated seepage ponds derive water primarily from ground water seeping into the pond, in a manner similar to a dug well completed in a surficial aquifer. The availability of water from seepage ponds is controlled by the permeability of surficial deposits, the amount of precipitation recharging the ground-water system, and the volume of water stored in the pond. The viability of seepage ponds as supplies for irrigation is limited by low seepage rates and high dependence on climatic conditions. Ponds will not refill unless there is adequate precipitation to recharge the surficial aquifer, which subsequently drains (seeps) into the pond. Ground-water seepage was estimated using a water-budget approach that utilized on-site climatic and hydrologic measurements, computing pond-volume changes during pond pumping tests, and by digital simulation using steady-state and transient ground-water flow models. From August 1999 to May 2000, the Glynn County pond was mostly losing water (as indicated by negative net seepage); whereas from October 2000 to June 2001, the Bulloch County pond was mostly gaining water. At both sites, most ground-water seepage entered the pond following major rainfall events that provided recharge to the surficial aquifer. Net ground-water seepage, estimated using water-budget analysis and simulation, ranged from -11.5 to 15 gallons per minute (gal/min) at the Glynn County pond site and from -55 to 31 gal/min at the Bulloch County pond site. Simulated values during pumping tests indicate that groundwater seepage to both ponds increases with decreased pond stage. At the Glynn County pond, simulated net ground-water seepage varied between 7.8 gal/min at the beginning of the test (high pond stage and low hydraulic gradient) and 103 gal

  15. Evaluation of relocation of unionid mussels into artificial ponds

    Science.gov (United States)

    Newton, T.J.; Monroe, E.M.; Kenyon, R.; Gutreuter, S.; Welke, K.I.; Thiel, P.A.

    2001-01-01

    Relocation of unionid mussels into refuges (e.g., hatchery ponds) has been suggested as a management tool to protect these animals from the threat of zebra mussel (Dreissena polymorpha) invasion. To evaluate the efficacy of relocation, we experimentally relocated 768 mussels, representing 5 species (Leptodea fragilis, Obliquaria reflexa, Fusconaia flava, Amblema plicata, and Quadrula quadrula) into an earthen pond at a National Fish Hatchery or back into the river. In both locations, mussels were placed into 1 of 4 treatments (mesh bags, corrals, and buried or suspended substrate-filled trays). Mussels were examined annually for survival, growth (shell length and wet mass), and physiological condition (glycogen concentration in foot and mantle and tissue condition index) for 36 mo in the pond or 40 mo in the river. We observed significant differences in mortality rates between locations (mortality was 4 times greater in the pond than in the river), among treatments (lowest mortality in the suspended trays), and among species (lower mortality in the amblemines than lamp-silines). Overall survival in both locations averaged 80% the 1st year; survival in the pond decreased dramatically after that. Although length and weight varied between locations and over time, these changes were small, suggesting that their utility as short-term measures of well being in long-lived unionids is questionable. Mussels relocated to the pond were in poor physiological condition relative to those in the river, but the magnitude of these differences was small compared to the inherent variability in physiological condition of reference mussels. These data suggest that relocation of unionids into artificial ponds is a high-risk conservation strategy; alternatives such as introduction of infected host fish, identification of mussel beds at greatest risk from zebra mussels, and a critical, large-scale assessment of the factors contributing to their decline should be explored.

  16. Par Pond vegetation status Summer 1995 -- June survey descriptive summary

    International Nuclear Information System (INIS)

    Mackey, H.E. Jr.; Riley, R.S.

    1995-06-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the shoreline aquatic plant communities in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level, indicated that much of the original plant communities and the intermediate shoreline communities present on the exposed sediments have been lost. The extensive old-field and emergent marsh communities that were present on the exposed shoreline during the drawdown have been flooded and much of the pre-drawdown Par Pond aquatic plant communities have not had sufficient time for re-establishment. The shoreline does, however, have extensive beds of maidencane which extend from the shoreline margin to areas as deep as 2 and perhaps 3 meters. Scattered individual plants of lotus and watershield are common and may indicate likely directions of future wetland development in Par Pond. In addition, within isolated coves, which apparently received ground water seepage and/or stream surface flows during the period of the Par Pond draw down, extensive beds of waterlilies and spike rush are common. Invasion of willow and red maple occurred along the lake shoreline as well. Although not absent from this survey, evidence of the extensive redevelopment of the large cattail and eel grass beds was not observed in this first survey of Par Pond. Future surveys during the growing seasons of 1995, 1996, and 1997 along with the evaluation of satellite date to map the areal extent of the macrophyte beds of Par Pond are planned

  17. Distribution of transuranic elements in a freshwater pond ecosystem

    International Nuclear Information System (INIS)

    Emery, R.M.; Klopfer, D.C.

    1976-01-01

    During the past two years a unique study has been initiated on the Hanford Reservation concerning the ecological behavior of plutonium and americium in a freshwater environment. This study involves a waste pond which has been receiving occasional low-level plutonium processing wastes for about 30 years. The pond has a sufficiently established ecosystem to provide an excellent location for limnological characterization. In addition, the ecological distribution of plutonium and americium is being investigated. The purpose of this work is to explain plutonium and americium concentrations at specific ecological sites, important export routes out of the pond, and potential pathways to man. The pond is also highly enriched with nutrients, thus supporting a high level of algal and macrophyte production. Seston (30 percent diatoms) appears to be the principal concentrator of transuranics in the pond system. The major sink for plutonium and americium in this system is the sediments. Organic floc, overlaying the pond sediments, is also a major concentrator of transuranics in this system. Aside from the seston and floc, no other ecological components of the pond appear to have concentrations significantly greater than those of the sediment. Dragonfly larvae, watercress, and snails show concentrations which approximate those of the sediments but nearly all other food web components have levels of plutonium and americium which are lower than those of the sediments. Thus, plutonium and americium seem to be relatively immobile in the aquatic ecosystem. However, the role of algae as a potential mechanism for the long-range ecological transport of plutonium and americium will receive additional attention

  18. Arctic sea ice melt pond fractal dimension - explained

    Science.gov (United States)

    Popovic, Predrag

    As Arctic sea ice starts to melt in the summer, pools of melt water quickly form on its surface, significantly changing its albedo, and impacting its subsequent evolution. These melt ponds often form complex geometric shapes. One characteristic of their shape, the fractal dimension of the pond boundaries, D, when plotted as a function of pond size, has been shown to transition between the two fundamental limits of D = 1 and D = 2 at some critical pond size. Here, we provide an explanation for this behavior. First, using aerial photographs, we show how this fractal transition curve changes with time, and show that there is a qualitative difference in the pond shape as ice transitions from impermeable to permeable. Namely, while ice is impermeable, maximum fractal dimension is less than 2, whereas after it becomes permeable, maximum fractal dimension becomes very close to 2. We then show how the fractal dimension of a collection of overlapping circles placed randomly on a plane also transitions from D = 1 to D = 2 at a size equal to the average size of a single circle. We, therefore, conclude that this transition is a simple geometric consequence of regular shapes connecting. The one physical parameter that can be extracted from the fractal transition curve is the length scale at which transition occurs. We provide a possible explanation for this length scale by noting that the flexural wavelength of the ice poses a fundamental limit on the size of melt ponds on permeable ice. If this is true, melt ponds could be used as a proxy for ice thickness.

  19. Polycyclic aromatic hydrocarbon contamination in stormwater detention pond sediments in coastal South Carolina.

    Science.gov (United States)

    Weinstein, John E; Crawford, Kevin D; Garner, Thomas R

    2010-03-01

    The purpose of this study was to characterize the polycyclic aromatic hydrocarbon (PAH) contamination in the sediments of stormwater detention ponds in coastal South Carolina. Levels of the sum of PAH analytes were significantly higher in the sediments of commercial ponds compared to that of reference, golf course, low-density residential, and high-density residential ponds. Isomer ratio analysis suggested that the predominant source of PAHs were pyrogenic; however, many ponds had a PAH signature consistent with mixed uncombusted and combusted PAH sources. PAH levels in these sediments could be modeled using both pond drainage area and pond surface area. These results demonstrate that the sediment from most commercial ponds, and a few residential and golf course ponds, were moderately contaminated with PAHs. PAH levels in these contaminated ponds exceeded between 42% and 75% of the ecological screening values for individual PAH analytes established by US EPA Region IV, suggesting that they may pose a toxicological risk to wildlife.

  20. The laboratory environmental algae pond simulator (LEAPS) photobioreactor: Validation using outdoor pond cultures of Chlorella sorokiniana and Nannochloropsis salina

    Energy Technology Data Exchange (ETDEWEB)

    Huesemann, M.; Williams, P.; Edmundson, S.; Chen, P.; Kruk, R.; Cullinan, V.; Crowe, B.; Lundquist, T.

    2017-09-01

    A bench-scale photobioreactor system, termed Laboratory Environmental Algae Pond Simulator (LEAPS), was designed and constructed to simulate outdoor pond cultivation for a wide range of geographical locations and seasons. The LEAPS consists of six well-mixed glass column photobioreactors sparged with CO2-enriched air to maintain a set-point pH, illuminated from above by a programmable multicolor LED lighting (0 to 2,500 µmol/m2-sec), and submerged in a temperature controlled water-bath (-2 °C to >60 °C). Measured incident light intensities and water temperatures deviated from the respective light and temperature set-points on average only 2.3% and 0.9%, demonstrating accurate simulation of light and temperature conditions measured in outdoor ponds. In order to determine whether microalgae strains cultured in the LEAPS exhibit the same linear phase biomass productivity as in outdoor ponds, Chlorella sorokiniana and Nannochloropsis salina were cultured in the LEAPS bioreactors using light and temperature scripts measured previously in the respective outdoor pond studies. For Chlorella sorokiniana, the summer season biomass productivity in the LEAPS was 6.6% and 11.3% lower than in the respective outdoor ponds in Rimrock, Arizona, and Delhi, California; however, these differences were not statistically significant. For Nannochloropsis salina, the winter season biomass productivity in the LEAPS was statistically significantly higher (15.2%) during the 27 day experimental period than in the respective outdoor ponds in Tucson, Arizona. However, when considering only the first 14 days, the LEAPS biomass productivity was only 9.2% higher than in the outdoor ponds, a difference shown to be not statistically significant. Potential reasons for the positive or negative divergence in LEAPS performance, relative to outdoor ponds, are discussed. To demonstrate the utility of the LEAPS in predicting productivity, two other strains – Scenedesmus obliquus and Stichococcus minor

  1. Advances in molten salt electrochemistry towards future energy systems

    International Nuclear Information System (INIS)

    Ito, Yasuhiko

    2005-01-01

    This review article describes some selected novel molten salt electrochemical processes which have been created/developed by the author and his coworkers, with emphasis on the applications towards future energy systems. After showing a perspective of the applications of molten salt electrochemistry from the viewpoints of energy and environment, several selected topics are described in detail, which include nitride fuel cycle in a nuclear field, hydrogen energy system coupled with ammonia economy, thermally regenerative fuel cell systems, novel Si production process for solar cell and novel molten salt electrochemical processes for various energy and environment related functional materials including nitrides, rare earth-transition metal alloys, fine particles obtained by plasma-induced electrolysis, and carbon film. And finally, the author stresses again, the importance and potential of molten salt electrochemistry, and encourages young students, scientists and researchers to march in a procession hand in hand towards a bright future of molten salts. (author)

  2. Solar thermal central receivers

    International Nuclear Information System (INIS)

    Vant-Hull, L.L.

    1993-01-01

    Market issues, environmental impact, and technology issues related to the Solar Central Receiver concept are addressed. The rationale for selection of the preferred configuration and working fluid are presented as the result of a joint utility-industry analysis. A $30 million conversion of Solar One to an external molten salt receiver would provide the intermediate step to a commercial demonstration plant. The first plant in this series could produce electricity at 11.2 cents/kWhr and the seventh at 8.2 cents/kWhr, completely competitive with projected costs of new utility plants in 1992

  3. Molten salt reactors: chemistry

    International Nuclear Information System (INIS)

    1983-01-01

    This work is a critical analysis of the 1000 MW MSBR project. Behavior of rare gases in the primary coolant circuit, their extraction from helium. Coating of graphite by molybdenum, chemistry of protactinium and niobium produced in the molten salt, continuous reprocessing of the fuel salt and use of stainless steel instead of hastelloy are reviewed [fr

  4. Influences of radiation on carp from farm ponds in Fukushima

    International Nuclear Information System (INIS)

    Suzuki, Yuzuru

    2015-01-01

    A massive release of artificial radionuclides from the Fukushima Dai-ichi Nuclear Power Plant caused radioactive contamination of farms as well as of aquatic products. Carp in small ponds in the highly radiocontaminated area of Iitate Village, Fukushima Prefecture, have been confined to the ponds since the accident, and it is thought that the carp may have suffered health issues as a result. Therefore, I investigated the health condition of the carp in order to elucidate the effects of radiation. Blood neutrophil, monocyte and lymphocyte counts in the carp from three ponds in Fukushima were lower than those in carp from a non-polluted pond in Tochigi Prefecture. Histological observations indicated abnormal hyperplasia of macrophages in the spleen, kidney, liver and pancreas of carp in Fukushima. Although there are likely to have been deleterious effects on carp health due to the radiation in Fukushima, this has not yet been confirmed because only one control pond was available for comparison, and I was not able to find any symptoms in the carp that correlated with internal cesium concentration. Further research is now being conducted to investigate the effects of radiation on carp

  5. PRACTICAL SOLUTIONS FOR ECOLOGICAL RECONSTRUCTION OF GERAI POND

    Directory of Open Access Journals (Sweden)

    Alexandru Dimache

    2012-06-01

    Full Text Available Gerai Pond is one of the last natural wetlands along the Danube, being connected to natural flooding regime of the Danube and is situated at the confluence of the Danube River, between Gârcov and Islaz localities, in Olt County. Aquatic vegetation characteristic is a favorable habitat for two species of conservation concern that nest along the Danube: red duck and pygmy cormorant. During 1961-1970, Gerai Pond has changed radically due to impoundment and draining under the program of drainage and flood meadow regulate of the Danube. These works of land reclamation for decreasing surface lakes and wetlands and water stagnation period, had reduced the breeding areas of the two species mentioned above. Ecological reconstruction of Gerai Pond project was conducted by Technical University of Civil Engineering of Bucharest in collaboration with E.P.A. Olt and W.W.F.-Romania. The project was based on a hydrological study (which included a component related to flooding for the area analyzed, study in which were highlighted the areas which have water access to and from the Pond, surfaces and volumes of water corresponding to different rates, the optimal level of water for restoration of the nesting area. Based on this study were identified the areas of artificial feed-water discharge to and from the Danube. This paper presents the possible solutions for ecological reconstruction of Gerai Pond, identified in the project.

  6. Par Pond vegetation status Summer 1995 -- September survey descriptive summary

    International Nuclear Information System (INIS)

    Mackey, H.E. Jr.; Riley, R.S.

    1995-09-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the emergent shoreline aquatic plant communities began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level and continued with this mid-September survey. Communities similar to the pre-drawdown Par Pond aquatic plant communities are becoming re-established; especially, beds of maidencane, lotus, waterlily, and watershield are now extensive and well established. Cattail occurrence continues to increase, but large beds common to Par Pond prior to the drawdown have not formed. Future surveys during the late growing seasons of 1995, and throughout 1996 and 1997, along with the evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned

  7. Par Pond vegetation status Summer 1995 -- October survey descriptive summary

    International Nuclear Information System (INIS)

    Mackey, H.E. Jr.; Riley, R.S.

    1995-11-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the emergent shoreline aquatic plant communities began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level and continued with this late October survey. Communities similar to the pre-drawdown Par Pond aquatic plant communities are becoming re-established; especially, beds of maiden cane, lotus, waterlily, and watershield are now extensive and well established. Cattail occurrence continues to increase, but large beds common to Par Pond prior to the drawdown have not formed. Future surveys throughout 1996 and 1997, along with the continued evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned

  8. Prediction of local effects of proposed cooling ponds

    International Nuclear Information System (INIS)

    Hicks, B.B.

    1978-01-01

    A Fog Excess Water (FEW) Index has been shown to provide a good measure of the likelihood for steam fog to occur at specific cooling pond installations. The FEW Index is derived from the assumption that the surface boundary layer over a cooling pond will be strongly convective, and that highly efficient vertical transport mechanisms will result in a thorough mixing of air saturated at surface temperature with ambient air aloft. Available data support this assumption. An extension of this approach can be used to derive a simple indicator for use in predicting the formation of rime ice in the immediate downwind environs of a cooling pond. In this case, it is supposed that rime ice will be deposited whenever steam fog and sub-freezing surface temperatures are predicted. This provides a convenient method for interpreting pre-existing meteorological information in order to assess possible icing effects while in the early design stages of the planning process. However, it remains necessary to derive accurate predictions of the cooling pond water surface temperature. Once a suitable and proven procedure for this purpose has been demonstrated, it is then a simple matter to employ the FEW Index in evaluations of the relative merits of alternative cooling pond designs, with the purpose of minimizing overall environmental impact

  9. Thermal performance measurements on ultimate heat sinks--cooling ponds

    International Nuclear Information System (INIS)

    Hadlock, R.K.; Abbey, O.B.

    1977-12-01

    The primary objective of the studies described is to obtain the requisite data, with respect to modeling requirements, to characterize thermal performance of heat sinks for nuclear facilities existing at elevated water temperatures in result of experiencing a genuinely large heat load and responding to meteorological influence. The data should reflect thermal performance for combinations leading to worst-case meteorological influence. A geothermal water retention basin has been chosen as the site for the first measurement program and data have been obtained in the first of several experiments scheduled to be performed there. These data illustrate the thermal and water budgets during episodes of cooling from an initially high pond water bulk temperature. Monitoring proceeded while the pond experienced only meteorological and seepage influence. The data are discussed and are presented as a data volume which may be used for calculation purposes. Suggestions for future measurement programs are stated with the intent to maintain and improve relevance to nuclear ultimate heat sinks while continuing to examine the performance of the analog geothermal pond. It is further suggested that the geothermal pond, with some modification, may be a suitable site for spray pond measurements

  10. Floating Solar Photovoltaics Gaining Ground | State, Local, and Tribal

    Science.gov (United States)

    flotovoltaics (a trademarked term) or floating solar, represent an emerging application in which PV panels are , including efficiency gains (due to water cooling the panels), reductions in unwanted algae growth, slower 994 panels floating on 130 foam-filled pontoons atop the winery's irrigation pond and an additional

  11. Salt Tolerance in Soybean

    Institute of Scientific and Technical Information of China (English)

    Tsui-Hung Phang; Guihua Shao; Hon-Ming Lam

    2008-01-01

    Soybean is an Important cash crop and its productivity is significantly hampered by salt stress. High salt Imposes negative impacts on growth, nodulation, agronomy traits, seed quality and quantity, and thus reduces the yield of soybean. To cope with salt stress, soybean has developed several tolerance mechanisms, including: (I) maintenance of ion homeostasis; (ii) adjustment in response to osmotic stress; (iii) restoration of osmotic balance; and (iv) other metabolic and structural adaptations. The regulatory network for abiotic stress responses in higher plants has been studied extensively in model plants such as Arabidopsis thaliana. Some homologous components involved in salt stress responses have been identified in soybean. In this review, we tried to integrate the relevant works on soybean and proposes a working model to descdbe Its salt stress responses at the molecular level.

  12. Geomechanics of bedded salt

    International Nuclear Information System (INIS)

    Serata, S.; Milnor, S.W.

    1979-01-01

    Creep data from the literature search is reinterpreted by SGI, resulting in a better understanding of the temperature and stress state dependence of the octahedral creep rate and the octahedral shear strength. The concept of a transition strength between the elastic and the plastic states is in agreement with the data. The elastic and rheological properties of salt are described, and a set of constitutive equations is presented. The dependence of material properties on parameters such as temperature is considered. Findings on the permeability of salt are summarized, and the in-situ behavior of openings in bedded salt is described based on extensive engineering experience. A stress measuring system utilizing a finite element computer code is discussed. Geological factors affecting the stability of salt openings are considered, and the Stress Control Technique for designing stable openings in bedded salt formations is explained

  13. Salt og forbrugervalg

    DEFF Research Database (Denmark)

    Mørk, Trine; Grunert, Klaus G

    af saltreducerede fødevarer og deres købsintention af disse. Dette blev undersøgt ved at måle forbrugerens viden om salt, anvendelse af salt, ønske om reduktion af salt og købsintention af saltreducerede fødevarer i en web-baseret undersøgelse. Efter den web-baserede undersøgelse, blev de samme mål...... undersøgt, men i et supermarked, hvor deltagerne blev inddelt i fire grupper for at undersøge effekten af priming og saltmærkning. Desuden blev der foretaget 15 kvalitative interviews, for at studere hvem og hvad der karakteriserer de deltagere i eksperimentet, som enten ender med ingen salt......-reducerede produkter at købe eller som ender med at købe alle de salt-reducerede produkter....

  14. Solar thermal electricity generation

    Science.gov (United States)

    Gasemagha, Khairy Ramadan

    1993-01-01

    This report presents the results of modeling the thermal performance and economic feasibility of large (utility scale) and small solar thermal power plants for electricity generation. A number of solar concepts for power systems applications have been investigated. Each concept has been analyzed over a range of plant power ratings from 1 MW(sub e) to 300 MW(sub e) and over a range of capacity factors from a no-storage case (capacity factor of about 0.25 to 0.30) up to intermediate load capacity factors in the range of 0.46 to 0.60. The solar plant's economic viability is investigated by examining the effect of various parameters on the plant costs (both capital and O & M) and the levelized energy costs (LEC). The cost components are reported in six categories: collectors, energy transport, energy storage, energy conversion, balance of plant, and indirect/contingency costs. Concentrator and receiver costs are included in the collector category. Thermal and electric energy transport costs are included in the energy transport category. Costs for the thermal or electric storage are included in the energy storage category; energy conversion costs are included in the energy conversion category. The balance of plant cost category comprises the structures, land, service facilities, power conditioning, instrumentation and controls, and spare part costs. The indirect/contingency category consists of the indirect construction and the contingency costs. The concepts included in the study are (1) molten salt cavity central receiver with salt storage (PFCR/R-C-Salt); (2) molten salt external central receiver with salt storage (PFCR/R-E-Salt); (3) sodium external central receiver with sodium storage (PFCR/RE-Na); (4) sodium external central receiver with salt storage (PFCR/R-E-Na/Salt); (5) water/steam external central receiver with oil/rock storage (PFCR/R-E-W/S); (6) parabolic dish with stirling engine conversion and lead acid battery storage (PFDR/SLAB); (7) parabolic dish

  15. An Implementation of the Salt-Farm Monitoring System Using Wireless Sensor Network

    Science.gov (United States)

    Ju, Jonggil; Park, Ingon; Lee, Yongwoong; Cho, Jongsik; Cho, Hyunwook; Yoe, Hyun; Shin, Changsun

    In producing solar salt, natural environmental factors such as temperature, humidity, solar radiation, wind direction, wind speed and rain are essential elements which influence on the productivity and quality of salt. If we can manage the above mentioned environmental elements efficiently, we could achieve improved results in production of salt with good quality. To monitor and manage the natural environments, this paper suggests the Salt-Farm Monitoring System (SFMS) which is operated with renewable energy power. The system collects environmental factors directly from the environmental measure sensors and the sensor nodes. To implement a stand-alone system, we applied solar cell and wind generator to operate this system. Finally, we showed that the SFMS could monitor the salt-farm environments by using wireless sensor nodes and operate correctly without external power supply.

  16. Lowering Salt in Your Diet

    Science.gov (United States)

    ... For Consumers Home For Consumers Consumer Updates Lowering Salt in Your Diet Share Tweet Linkedin Pin it ... Subscribe: FDA Consumer Health Information Everyone needs some salt to function. Also known as sodium chloride, salt ...

  17. Water purification using organic salts

    Science.gov (United States)

    Currier, Robert P.

    2004-11-23

    Water purification using organic salts. Feed water is mixed with at least one organic salt at a temperature sufficiently low to form organic salt hydrate crystals and brine. The crystals are separated from the brine, rinsed, and melted to form an aqueous solution of organic salt. Some of the water is removed from the aqueous organic salt solution. The purified water is collected, and the remaining more concentrated aqueous organic salt solution is reused.

  18. Recovery of aquatic insect-mediated methylmercury flux from ponds following drying disturbance.

    Science.gov (United States)

    Chumchal, Matthew M; Drenner, Ray W; Greenhill, Frank M; Kennedy, James H; Courville, Ashlyn E; Gober, Charlie A A; Lossau, Luke O

    2017-08-01

    Small ponds exist across a permanence gradient, and pond permanence is hypothesized to be a primary determinant of insect community structure and insect-mediated methylmercury (MeHg) flux from ponds to the surrounding terrestrial landscape. The present study describes the first experiment examining the recovery of insect-mediated MeHg flux following a drying disturbance that converted permanent ponds with insectivorous fish to semipermanent ponds without fish. Floating emergence traps were used to collect emergent insects for 10 wk in the spring and summer from 5 ponds with fish (permanent) and 5 ponds that were drained to remove fish, dried, and refilled with water (semipermanent). During the 73-d period after semipermanent ponds were refilled, total MeHg flux from semipermanent ponds was not significantly different than total MeHg flux from permanent ponds, indicating that insect-mediated MeHg flux had rapidly recovered in semipermanent ponds following the drying disturbance. Methylmercury fluxes from dragonflies (Odonata: Anisoptera) and phantom midges (Diptera: Chaoboridae) were significantly greater from newly refilled semipermanent ponds than permanent ponds, but the MeHg fluxes from the other 8 emergent insect taxa did not differ between treatments. The present study demonstrates the impact of drying disturbance and the effect of community structure on the cross-system transport of contaminants from aquatic to terrestrial ecosystems. Environ Toxicol Chem 2017;36:1986-1990. © 2017 SETAC. © 2017 SETAC.

  19. Lime application methods, water and bottom soil acidity in fresh water fish ponds

    Directory of Open Access Journals (Sweden)

    Queiroz Julio Ferraz de

    2004-01-01

    Full Text Available Although some methods for determining lime requirement of pond soils are available and commonly used, there is still no consensus on whether it is more effective to apply liming materials to the bottoms of empty ponds or to wait and apply them over the water surface after ponds are filled. There is also little information on how deep lime reacts in pond sediment over time, and whether the depth of reaction is different when liming materials are applied to the water or to the soil. Therefore, three techniques for treating fish ponds with agricultural limestone were evaluated in ponds with clayey soils at a commercial fish farm. Amounts of agricultural limestone equal to the lime requirement of bottom soils were applied to each of three ponds by: direct application over the pond water surface; spread uniformly over the bottom of the empty pond; spread uniformly over the bottom of the empty pond followed by tilling of the bottom. Effectiveness of agricultural limestone applications did not differ among treatment methods. Agricultural limestone also reacted quickly to increase total alkalinity and total hardness of pond water to acceptable concentrations within 2 weeks after application. The reaction of lime to increase soil pH was essentially complete after one to two months, and lime had no effect below a soil depth of 8 cm. Tilling of pond bottoms to incorporate liming materials is unnecessary, and tilling consumes time and is an expensive practice; filled ponds can be limed effectively.

  20. Calculations of condensed moisture escape from a NPP spray pond

    International Nuclear Information System (INIS)

    Bratuta, Eh. G.; Yaroshenko, T.I.

    1988-01-01

    A method for calculating water losses due to condensed moisture escape with a wind away from a spray pond used for cooling steam turbine condensator water and emergency nuclear reactor cooling is developed. The method is based on solving a three-dimensional equation of single drop motion, assuming that during the whole flight only gravity and aerodynamic resistance forces act on a drop. The basic parameter variation ranges are the following: 0-18 m/s wind velocity, 0.04-0.12 MPa pressure drop at the nozzle output, 1-2 m height of sprayers above the pond mirror. The given method permits to determine both the amount of circulation water loss and the local liquid flow rate distribution pattern as well as the area around the pond receiving the escaped moisture that is necessary for estimating the ecological situation near a NPP

  1. Garden ponds as potential introduction pathway of ornamental crayfish

    Directory of Open Access Journals (Sweden)

    Patoka J.

    2014-01-01

    Full Text Available The private stocking of ornamental crayfish in garden ponds was discussed in previous studies, but there is a lack of detailed analysis for better understanding of this introduction pathway. The Czech Republic is one of leading EU countries in trade with ornamental crayfish and private garden ponds are popular among people. The crayfish keepers in the country were interviewed by self-administered questionnaire to gather data about principal characteristics of the keepers and detailed information about crayfish breeding that are of interest for conservation managers. Besides of releasing crayfish into garden ponds, alarming illegal behavior such as releasing of juvenile crayfish into the wild, and capturing of indigenous crayfish from wild populations, were registered. Therefore focusing on public education to increase awareness of possible unwanted consequences of crayfish release and introduction of an obligation to inform customers about hazardousness of non-indigenous crayfish species for retailers and wholesalers is recommended.

  2. Experimental studies on natural circulation in molten salt loops

    International Nuclear Information System (INIS)

    Srivastava, A.K.; Borgohain, A.; Maheshwari, N.K.; Vijayan, P.K.

    2015-01-01

    Molten salts are increasingly getting attention as a coolant and storage medium in solar thermal power plants and as a liquid fuel, blanket and coolant in Molten Salt Reactors (MSR’s). Two different test facilities named Molten Salt Natural Circulation Loop (MSNCL) and Molten Active Fluoride salt Loop (MAFL) have been setup for thermal hydraulics, instrument development and material related studies relevant to MSR and solar power plants. The working medium for MSNCL is a molten nitrate salt which is a mixture of NaNO 3 and KNO 3 in 60:40 ratio and proposed as one of the coolant option for molten salt based reactor and coolant as well as storage medium for solar thermal power application. On the other hand, the working medium for MAFL is a eutectic mixture of LiF and ThF 4 and proposed as a blanket salt for Indian Molten Salt Breeder Reactor (MSBR). Steady state natural circulation experiments at different power level have been performed in the MSNCL. Transient studies for startup of natural circulation, loss of heat sink, heater trip and step change in heater power have also been carried out in the same. A 1D code LeBENC, developed in-house to simulate the natural circulation characteristics in closed loops, has been validated with the experimental data obtained from MSNCL. Further, LeBENC has been used for Pretest analysis of MAFL. This paper deals with the description of both the loops and experimental studies carried out in MSNCL. Validation of LeBENC along with the pretest analysis of MAFL using the same are also reported in this paper. (author)

  3. Solar building

    OpenAIRE

    Zhang, Luxin

    2014-01-01

    In my thesis I describe the utilization of solar energy and solar energy with building integration. In introduction it is also mentioned how the solar building works, trying to make more people understand and accept the solar building. The thesis introduces different types of solar heat collectors. I compared the difference two operation modes of solar water heating system and created examples of solar water system selection. I also introduced other solar building applications. It is conv...

  4. Restoration of a shady urban pond - The pros and cons.

    Science.gov (United States)

    Jurczak, Tomasz; Wojtal-Frankiewicz, Adrianna; Kaczkowski, Zbigniew; Oleksińska, Zuzanna; Bednarek, Agnieszka; Zalewski, Maciej

    2018-07-01

    The Bzura-7 pond (Łódź, Poland) is a typical shallow and shady urban reservoir situated on the Bzura River that is exposed to pollutants introduced mainly by internal loads and the supply from the catchment. In 2010-2012, the following characteristics were observed in the pond: a high allochthonous input of organic matter, high concentration of ammonium, low concentration of dissolved oxygen and low diversity of zooplankton, dominated mainly by Daphnia spp. From January to June 2013, restoration measures were performed, including sediment removal, increasing light access to the pond and construction of a sequential sedimentation-biofiltration system (SSBS). The aim of the present study was to investigate how the water quality in the Bzura-7 pond was affected by the restoration process, which included reducing pollutant inflows and enhancing habitat potential, thus increasing the diversity of this ecosystem. Restoration efforts improved the chemical and physical parameters of the water. The oxygen concentration increased, and the concentrations of TN and ammonium significantly decreased. Despite the increase in pond lighting, the growth of cyanobacteria was limited. However, we observed increased abundance of green algae and diatoms but less than adequate changes in the zooplankton community structures. Although we observed a significant increase in the zooplankton species richness after restoration, this increase was related to the small-bodied groups of zooplankton, rotifers and bosminiids, characteristic of eutrophic ecosystems. In addition, a planktivorous fish - sunbleak (Leucaspius delineatus) - was identified as an unintended side effect of the restoration effort. Further conservation efforts in the Bzura-7 pond and monitoring of results are still needed. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. A holistic water depth simulation model for small ponds

    Science.gov (United States)

    Ali, Shakir; Ghosh, Narayan C.; Mishra, P. K.; Singh, R. K.

    2015-10-01

    Estimation of time varying water depth and time to empty of a pond is prerequisite for comprehensive and coordinated planning of water resource for its effective utilization. A holistic water depth simulation (HWDS) and time to empty (TE) model for small, shallow ephemeral ponds have been derived by employing the generalized model based on the Green-Ampt equation in the basic water balance equation. The HWDS model includes time varying rainfall, runoff, surface water evaporation, outflow and advancement of wetting front length as external inputs. The TE model includes two external inputs; surface water evaporation and advancement of wetting front length. Both the models also consider saturated hydraulic conductivity and fillable porosity of the pond's bed material as their parameters. The solution of the HWDS model involved numerical iteration in successive time intervals. The HWDS model has successfully evaluated with 3 years of field data from two small ponds located within a watershed in a semi-arid region in western India. The HWDS model simulated time varying water depth in the ponds with high accuracy as shown by correlation coefficient (R2 ⩾ 0.9765), index of agreement (d ⩾ 0.9878), root mean square errors (RMSE ⩽ 0.20 m) and percent bias (PB ⩽ 6.23%) for the pooled data sets of the measured and simulated water depth. The statistical F and t-tests also confirmed the reliability of the HWDS model at probability level, p ⩽ 0.0001. The response of the TE model showed its ability to estimate the time to empty the ponds. An additional field calibration and validation of the HWDS and TE models with observed field data in varied hydro-climatic conditions could be conducted to increase the applicability and credibility of the models.

  6. Legacy of road salt: Apparent positive larval effects counteracted by negative postmetamorphic effects in wood frogs.

    Science.gov (United States)

    Dananay, Kacey L; Krynak, Katherine L; Krynak, Timothy J; Benard, Michael F

    2015-10-01

    Road salt runoff has potentially large effects on wetland communities, but is typically investigated in short-term laboratory trials. The authors investigated effects of road salt contamination on wood frogs (Rana sylvatica) by combining a field survey with 2 separate experiments. The field survey tested whether wood frog larval traits were associated with road salt contamination in natural wetlands. As conductivity increased, wood frog larvae were less abundant, but those found were larger. In the first experiment of the present study, the authors raised larvae in outdoor artificial ponds under 4 salt concentrations and measured larval vital rates, algal biomass, and zooplankton abundance. Salt significantly increased larval growth, algal biomass, and decreased zooplankton abundance. In the second experiment, the authors raised larvae to metamorphosis in the presence and absence of salt contamination and followed resulting juvenile frogs in terrestrial pens at high and low densities. Exposure to road salt as larvae caused juvenile frogs to have greater mortality in low-density terrestrial environments, possibly because of altered energy allocation, changes in behavior, or reduced immune defenses. The present study suggests that low concentrations of road salt can have positive effects on larval growth yet negative effects on juvenile survival. These results emphasize the importance of testing for effects of contaminants acting through food webs and across multiple life stages as well as the potential for population-level consequences in natural environments. © 2015 SETAC.

  7. Crushed Salt Constitutive Model

    International Nuclear Information System (INIS)

    Callahan, G.D.

    1999-01-01

    The constitutive model used to describe the deformation of crushed salt is presented in this report. Two mechanisms -- dislocation creep and grain boundary diffusional pressure solution -- are combined to form the basis for the constitutive model governing the deformation of crushed salt. The constitutive model is generalized to represent three-dimensional states of stress. Upon complete consolidation, the crushed-salt model reproduces the Multimechanism Deformation (M-D) model typically used for the Waste Isolation Pilot Plant (WIPP) host geological formation salt. New shear consolidation tests are combined with an existing database that includes hydrostatic consolidation and shear consolidation tests conducted on WIPP and southeastern New Mexico salt. Nonlinear least-squares model fitting to the database produced two sets of material parameter values for the model -- one for the shear consolidation tests and one for a combination of the shear and hydrostatic consolidation tests. Using the parameter values determined from the fitted database, the constitutive model is validated against constant strain-rate tests. Shaft seal problems are analyzed to demonstrate model-predicted consolidation of the shaft seal crushed-salt component. Based on the fitting statistics, the ability of the model to predict the test data, and the ability of the model to predict load paths and test data outside of the fitted database, the model appears to capture the creep consolidation behavior of crushed salt reasonably well

  8. Molten salt reactors

    International Nuclear Information System (INIS)

    Bouchter, J.C.; Dufour, P.; Guidez, J.; Simon, N.; Renault, C.

    2014-01-01

    Molten salt reactors are one of the 6 concepts retained for the 4. generation of nuclear reactors. The principle of this reactor is very innovative: the nuclear fuel is dissolved in the coolant which allows the online reprocessing of the fuel and the online recovery of the fission products. A small prototype: the Molten Salt Reactor Experiment (MSRE - 8 MWt) was operating a few years in the sixties in the USA. The passage towards a fast reactor by the suppression of the graphite moderator leads to the concept of Molten Salt Fast Reactor (MSFR) which is presently studied through different European projects such as MOST, ALISIA and EVOL. Worldwide the main topics of research are: the adequate materials resisting to the high level of corrosiveness of the molten salts, fuel salt reprocessing, the 3-side coupling between neutron transport, thermohydraulics and thermo-chemistry, the management of the changing chemical composition of the salt, the enrichment of lithium with Li 7 in the case of the use of lithium fluoride salt and the use of MSFR using U 233 fuel (thorium cycle). The last part of the article presents a preliminary safety analysis of the MSFR. (A.C.)

  9. Valuating Ecosystem Services of Urban Ponds - case study from Bangladesh

    Science.gov (United States)

    Carle, Nina

    2016-04-01

    A climate risk assessment for the city of Barisal was carried out by a consultancy firm, financed by KfW Development Bank of Germany. Due to high dependencies on natural capital of people in developing countries they are facing high vulnerability when it comes to changes of the asset category 'natural capital' (here: urban ponds), whether due to the exposition on climate (change) related impacts, implemented measures or land use change. With a closer view on the city's assets, the question remained open to the author 1) Under current conditions, what is the demand for ecosystem services (ES) 2) What is the value of the benefits and the how much is the contribution to the city's welfare? 3) What are the future changes in the demand for ES? And what are the future changes on the supply side (pressures and threats to the ecosystem)? Methodology: The City of Barisal in Bangladesh has a calculated number of around 10.000 urban rain-fed ponds,representing 6.5% of the city area, which represents a huge natural water supply and gives the city its characteristic face. In August 2015 a user survey was conducted in the city of Barisal, in every ward (administrative unit), to determine the demand for ecosystem services related to urban ponds, evaluating over 600 ponds. The findings will present the huge variation of provisioning ecosystem services and an important regulating service, related to economic and domestic use, in a spatial resolution. It will be shown, how the importance of ES changes, by changing the unit of analysis (families or ponds or the city) and the importance for the livelihood of pond owners and users. A relationship between pond area(m2) and number of users was detected, also the role of compensation payments for the pond owners by the users. It will be shown how natural capital, privately and publicly owned,contributes in an important way in buffering unequal distribution of societies resources in the short- and long-run. However society's demand for ES

  10. Arctic melt ponds and energy balance in the climate system

    Science.gov (United States)

    Sudakov, Ivan

    2017-02-01

    Elements of Earth's cryosphere, such as the summer Arctic sea ice pack, are melting at precipitous rates that have far outpaced the projections of large scale climate models. Understanding key processes, such as the evolution of melt ponds that form atop Arctic sea ice and control its optical properties, is crucial to improving climate projections. These types of critical phenomena in the cryosphere are of increasing interest as the climate system warms, and are crucial for predicting its stability. In this paper, we consider how geometrical properties of melt ponds can influence ice-albedo feedback and how it can influence the equilibria in the energy balance of the planet.

  11. Arctic melt ponds and bifurcations in the climate system

    Science.gov (United States)

    Sudakov, I.; Vakulenko, S. A.; Golden, K. M.

    2015-05-01

    Understanding how sea ice melts is critical to climate projections. In the Arctic, melt ponds that develop on the surface of sea ice floes during the late spring and summer largely determine their albedo - a key parameter in climate modeling. Here we explore the possibility of a conceptual sea ice climate model passing through a bifurcation point - an irreversible critical threshold as the system warms, by incorporating geometric information about melt pond evolution. This study is based on a bifurcation analysis of the energy balance climate model with ice-albedo feedback as the key mechanism driving the system to bifurcation points.

  12. Storage ponds for fuel elements of nuclear reactors

    International Nuclear Information System (INIS)

    Kumpf, H.

    1981-01-01

    Heat exchangers are inserted in storage ponds for fuel elements of nuclear reactors, so that the heat to be removed is given up to an external coolant, without any radio-activity being emitted. The heat exchanger is a hollow body, which is connected to an air cooler, which works with a cooling circuit with natural circulation. A cooling pipe is enclosed in the hollow body, which forms a cooling circuit with forced flow with an open pond. One therefore obtains two successive separating walls for the external coolant. (orig.) [de

  13. Solar energy

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This chapter discusses the role solar energy may have in the energy future of the US. The topics discussed in the chapter include the solar resource, solar architecture including passive solar design and solar collectors, solar-thermal concentrating systems including parabolic troughs and dishes and central receivers, photovoltaic cells including photovoltaic systems for home use, and environmental, health and safety issues

  14. Gases in molten salts

    CERN Document Server

    Tomkins, RPT

    1991-01-01

    This volume contains tabulated collections and critical evaluations of original data for the solubility of gases in molten salts, gathered from chemical literature through to the end of 1989. Within the volume, material is arranged according to the individual gas. The gases include hydrogen halides, inert gases, oxygen, nitrogen, hydrogen, carbon dioxide, water vapor and halogens. The molten salts consist of single salts, binary mixtures and multicomponent systems. Included also, is a special section on the solubility of gases in molten silicate systems, focussing on slags and fluxes.

  15. A survey for the presence of microcystins in aquaculture ponds in ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-16

    Nov 16, 2009 ... form of blue green algae in an aquaculture pond, they. *Corresponding author. ... passing through the food chain. Fish and other ... Some of these aqua- culture ponds supply their products (harvested fish) directly to spe-.

  16. DNR 100K Lakes - Fishing in the Neighborhood (FiN) Ponds

    Data.gov (United States)

    Minnesota Department of Natural Resources — This layer represents ponds included in DNR's Fishing in the Neighborhood (FiN) program. This program establishes local ponds to provide urban fishing opportunities...

  17. Aquatic biodiversity in sedimentation ponds receiving road runoff - What are the key drivers?

    Science.gov (United States)

    Sun, Zhenhua; Brittain, John E; Sokolova, Ekaterina; Thygesen, Helene; Saltveit, Svein Jakob; Rauch, Sebastien; Meland, Sondre

    2018-01-01

    Recently, increased attention has been paid to biodiversity conservation provided by blue-green solutions such as engineered ponds that are primarily established for water treatment and flood control. However, little research has been done to analyse the factors that affect biodiversity in such ponds. The purpose of this study was to evaluate the influence of environmental factors on aquatic biodiversity, mainly macroinvertebrate communities, in road sedimentation ponds in order to provide a foundation for recommendations on aquatic biodiversity conservation. Multivariate statistical methods, including unconstrained and constrained analysis, were applied to examine the relationships between organisms and the water quality as well as physical factors (including plant cover). Stepwise multiple regressions indicated that the most important variables governing the variation in the biological community composition were pond size, average annual daily traffic, metals, chloride, distance to the closest pond from study pond, dissolved oxygen, hydrocarbons, and phosphorus. The presence of most taxa was positively correlated with pond size and negatively correlated with metals. Small ponds with high pollutant loadings were associated with a low diversity and dominated by a few pollution tolerant taxa such as oligochaetes. A comprehensive understanding of impacts of various environmental factors on aquatic biodiversity is important to effectively promote and conserve aquatic biodiversity in such sedimentation ponds. Our results indicate that road sedimentation ponds should be designed large enough, because large ponds are likely to provide a more heterogeneous habitat and thus contain a species rich fauna. In addition, larger ponds seem to be less contaminated due to dilution compared to smaller ponds, thereby maintaining a higher biodiversity. Finally, creating some additional ponds in the vicinity of the sedimentation ponds in areas with few water bodies would increase the

  18. Use of cooling ponds and hydraulic turbines to save SRP energy consumption

    International Nuclear Information System (INIS)

    Price, J.B.

    1980-01-01

    A substantial amount of energy can be saved by using cooling ponds to supply C and K reactors with cooling water. Hydraulic turbines between the reactor and the cooling pond can recover some of the power used to pump cooling water to the reactors. Cooling ponds would also reduce effluent temperature in the swamps adjacent to the Savannah River. Cooling ponds are evaluated in this memorandum

  19. Validation Hydrodynamic Models of Three Topological Models of Secondary Facultative Ponds

    OpenAIRE

    Aponte-Reyes Alxander

    2014-01-01

    A methodology was developed to analyze boundary conditions, the size of the mesh and the turbulence of a mathematical model of CFD, which could explain hydrodynamic behavior on facultative stabilization ponds, FSP, built to pilot scale: conventional pond, CP, baffled pond, BP, and baffled-mesh pond, BMP. Models dispersion studies were performed in field for validation, taking samples into and out of the FSP, the information was used to carry out CFD model simulations of the three topologies. ...

  20. Temporal dynamics of flooding, evaporation, and desiccation cycles and observations of salt crust area change at the Bonneville Salt Flats, Utah

    Science.gov (United States)

    Bowen, Brenda B.; Kipnis, Evan L.; Raming, Logan W.

    2017-12-01

    The Bonneville Salt Flats (BSF) in Utah is a dynamic saline playa environment responding to natural and anthropogenic forces. Over the last century, the saline groundwater from below BSF has been harvested to produce potash via evaporative mining, mostly used as agricultural fertilizers, while the surface halite crust has provided a significant recreational site for land speed racing. Perceptions of changes in the salt crust through time have spurred debates about land use and management; however, little is known about the timescales of natural change as the salt crust responds to climatic parameters that drive flooding, evaporation, and desiccation (FED) cycles that control surface salt growth and dissolution. Climate data over the last 30 years are examined to identify annual patterns in surface water balance at BSF to identify annual and seasonal climate constraints on FED cycles. Landsat satellite data from 1986 to the present are used to map the areal extent of the surface halite salt crust at BSF at the end of the desiccation season (between August 15 and October 30) annually. Overall, the observed area of the desiccation-stage BSF halite crust has varied from a maximum of 156 km2 in 1993 to a minimum of 72 km2 in 2014 with an overall trend of declining area of halite observed over the 30 years of analysis. Climatic variables that influence FED cycles and seasonal salt dissolution and precipitation have also varied through this time period; however, the relationship between surface water fluxes and salt crust area do not clearly correlate, suggesting that other processes are influencing the extent of the salt. Intra-annual analyses of salt area and weather illustrate the importance of ponded surface water, wind events, and microtopography in shaping a laterally extensive but thin and ephemeral halite crust. Examination of annual to decadal changes in salt crust extent and environmental parameters at BSF provides insights into the processes driving change and

  1. Review and evaluation of information on the thermal performance of ultimate heat sinks: spray ponds and cooling ponds

    International Nuclear Information System (INIS)

    Drake, R.L.

    1975-09-01

    A report is presented which identifies and evaluates available information and data useful in validating and improving existing models for the thermal performance of ultimate heat sinks. Included are discussions of the thermal elements of cooling ponds and spray ponds, the available information and data pertinent to the problem, and the requirements and needs for further research and performance data. An outline is presented of the necessary elements required for a performance test of an ultimate heat sink before the system is thermally approved. (auth)

  2. What Are Bath Salts?

    Science.gov (United States)

    ... bath salts can produce: feelings of joy increased social interaction increased sex drive paranoia nervousness hallucinations (see or ... Institutes of Health; U.S. Department of Health and Human Services. Cite this article APA Style MLA Style ...

  3. Synthetic Cathinones ("Bath Salts")

    Science.gov (United States)

    ... Alcohol Club Drugs Cocaine Fentanyl Hallucinogens Inhalants Heroin Marijuana MDMA (Ecstasy/Molly) Methamphetamine Opioids Over-the-Counter Medicines Prescription Medicines Steroids (Anabolic) Synthetic Cannabinoids (K2/Spice) Synthetic Cathinones (Bath Salts) Tobacco/ ...

  4. Data analysis protocol for using resistivity array as an early-warning wastewater pond leak detector

    Science.gov (United States)

    Typically, holding ponds are used to control runoff from concentrated animal feeding operations. The integrity of these holding ponds has come under increased scrutiny since subsurface leakage has the potential to affect soil and groundwater quality. Traditionally, ponds are monitored by installin...

  5. Performance and Modelling of a Highway Wet Detention Pond Designed for Cold Climate

    DEFF Research Database (Denmark)

    Vollertsen, Jes; Åstebøl, Svein Ole; Coward, Jan Emil

    2009-01-01

    A wet detention pond in Norway has been monitored for 12 months. The pond receives runoff from a highway with a traffic load of 42,000 average daily traffic. Hydraulic conditions in terms of inflow, outflow, and pond water level were recorded every minute. Water quality was monitored by volume pr...

  6. Simple Rules Govern the Patterns of Arctic Sea Ice Melt Ponds

    Science.gov (United States)

    Popović, Predrag; Cael, B. B.; Silber, Mary; Abbot, Dorian S.

    2018-04-01

    Climate change, amplified in the far north, has led to rapid sea ice decline in recent years. In the summer, melt ponds form on the surface of Arctic sea ice, significantly lowering the ice reflectivity (albedo) and thereby accelerating ice melt. Pond geometry controls the details of this crucial feedback; however, a reliable model of pond geometry does not currently exist. Here we show that a simple model of voids surrounding randomly sized and placed overlapping circles reproduces the essential features of pond patterns. The only two model parameters, characteristic circle radius and coverage fraction, are chosen by comparing, between the model and the aerial photographs of the ponds, two correlation functions which determine the typical pond size and their connectedness. Using these parameters, the void model robustly reproduces the ponds' area-perimeter and area-abundance relationships over more than 6 orders of magnitude. By analyzing the correlation functions of ponds on several dates, we also find that the pond scale and the connectedness are surprisingly constant across different years and ice types. Moreover, we find that ponds resemble percolation clusters near the percolation threshold. These results demonstrate that the geometry and abundance of Arctic melt ponds can be simply described, which can be exploited in future models of Arctic melt ponds that would improve predictions of the response of sea ice to Arctic warming.

  7. Investigations for decision making on an old tailing pond of a former experimental metallurgical plant

    International Nuclear Information System (INIS)

    Razikov, Z.A.; Pavljuk, L.M.; Bezzubov, N.I.

    2002-01-01

    Investigations are described on an abandoned tailing pond of a former experimental metallurgical plant which operated during the period 1945-1950. The aim of these investigations was to explore radiological hazards arising from the tailing pond for the population and to obtain data for decision making on redeployment or dumping of the pond. Methods used, results obtained and conclusions drawn are outlined. (author)

  8. Food inputs, water quality and nutrient accumulation in integrated pond systems: A multivariate approach

    NARCIS (Netherlands)

    Nhan, D.K.; Milstein, A.; Verdegem, M.C.J.; Verreth, J.A.J.

    2006-01-01

    A participatory on-farm study was conducted to explore the effects of food input patterns on water quality and sediment nutrient accumulation in ponds, and to identify different types of integrated pond systems. Ten integrated agriculture-aquaculture (IAA) farms, in which ponds associate with fruit

  9. Estimating the ratio of pond size to irrigated soybean land in Mississippi: a case study

    Science.gov (United States)

    Ying Ouyang; G. Feng; J. Read; T. D. Leininger; J. N. Jenkins

    2016-01-01

    Although more on-farm storage ponds have been constructed in recent years to mitigate groundwater resources depletion in Mississippi, little effort has been devoted to estimating the ratio of on-farm water storage pond size to irrigated crop land based on pond metric and its hydrogeological conditions.  In this study, two simulation scenarios were chosen to...

  10. Simple Rules Govern the Patterns of Arctic Sea Ice Melt Ponds.

    Science.gov (United States)

    Popović, Predrag; Cael, B B; Silber, Mary; Abbot, Dorian S

    2018-04-06

    Climate change, amplified in the far north, has led to rapid sea ice decline in recent years. In the summer, melt ponds form on the surface of Arctic sea ice, significantly lowering the ice reflectivity (albedo) and thereby accelerating ice melt. Pond geometry controls the details of this crucial feedback; however, a reliable model of pond geometry does not currently exist. Here we show that a simple model of voids surrounding randomly sized and placed overlapping circles reproduces the essential features of pond patterns. The only two model parameters, characteristic circle radius and coverage fraction, are chosen by comparing, between the model and the aerial photographs of the ponds, two correlation functions which determine the typical pond size and their connectedness. Using these parameters, the void model robustly reproduces the ponds' area-perimeter and area-abundance relationships over more than 6 orders of magnitude. By analyzing the correlation functions of ponds on several dates, we also find that the pond scale and the connectedness are surprisingly constant across different years and ice types. Moreover, we find that ponds resemble percolation clusters near the percolation threshold. These results demonstrate that the geometry and abundance of Arctic melt ponds can be simply described, which can be exploited in future models of Arctic melt ponds that would improve predictions of the response of sea ice to Arctic warming.

  11. Heat transfer investigation of molten salts under laminar and turbulent flow regimes

    International Nuclear Information System (INIS)

    Srivastava, A.K.; Vaidya, A.M.; Maheshwari, N.K.; Vijayan, P.K.

    2014-01-01

    High temperature reactor and solar thermal power plants use Molten Salt as a coolant, as it has low melting point and high boiling point, enabling us to operate the system at low pressure. Molten fluoride salt (eutectic mixture of LiF-NaF-KF) and molten nitrate salt (mixture of NaNO 3 and KNO 3 in 60:40 ratios by weight) are proposed as a candidate coolant for High Temperature Reactors (HTR) and solar power plant respectively. BARC is developing a 600 MWth pebble bed high temperature reactor, cooled by natural circulation of fluoride salt and capable of supplying process heat at 1000℃ to facilitate hydrogen production by splitting water. Beside this, BARC is also developing a 2MWe solar power tower system using molten nitrate salt as a primary coolant and storage medium. In order to design this, it is necessary to study the heat transfer characteristics of various molten salts. Most of the previous studies related to molten salts are based on the experimental works. These experiments essentially measured the physical properties of molten salts and their heat transfer characteristics. Ferri et al. introduced the property definitions for molten salts in the RELAP5 code to perform transient simulations at the ProvaCollettoriSolari (PCS) test facility. In this paper, a CFD analysis has been performed to study the heat transfer characteristics of molten fluoride salt and molten nitrate salt flowing in a circular pipe for various regimes of flow. Simulation is performed with the help of in-house developed CFD code, NAFA, acronym for Numerical Analysis of Flows in Axi-symmetric geometries. Uniform velocity and temperature distribution are set as the inlet boundary condition and pressure is employed at the outlet boundary condition. The inlet temperature for all simulation is set as 300℃ for nitrate salt and 500℃ for fluoride salt and the operating pressure is 1 atm in both the cases

  12. Mass transport in bedded salt and salt interbeds

    International Nuclear Information System (INIS)

    Hwang, Y.; Pigford, T.H.; Chambre, P.L.; Lee, W.W.L.

    1989-08-01

    Salt is the proposed host rock for geologic repositories of nuclear waste in several nations because it is nearly dry and probably impermeable. Although experiments and experience at potential salt sites indicate that salt may contain brine, the low porosity, creep, and permeability of salt make it still a good choice for geologic isolation. In this paper we summarize several mass-transfer and transport analyses of salt repositories. The mathematical details are given in our technical reports

  13. Purple Salt and Tiny Drops of Water in Meteorites

    Science.gov (United States)

    Taylor, G. J.

    1999-12-01

    Some meteorites, especially those called carbonaceous chondrites, have been greatly affected by reaction with water on the asteroids in which they formed. These reactions, which took place during the first 10 million years of the Solar System's history, formed assorted water-bearing minerals, but nobody has found any of the water that caused the alteration. Nobody, that is, until now. Michael Zolensky and team of scientists from the Johnson Space Center in Houston and Virginia Tech (Blacksburg, Virginia) discovered strikingly purple sodium chloride (table salt) crystals in two meteorites. The salt contains tiny droplets of salt water (with some other elements dissolved in it). The salt is as old as the Solar System, so the water trapped inside the salt is also ancient. It might give us clues to the nature of the water that so pervasively altered carbonaceous chondrites and formed oceans on Europa and perhaps other icy satellites. However, how the salt got into the two meteorites and how it trapped the water remains a mystery - at least for now.

  14. Molten salt reactor type

    International Nuclear Information System (INIS)

    1977-01-01

    This document is one of the three parts of a first volume devoted to the compilations of American data on the molten salt reactor concept. Emphasize is put essentially on the fuel salt of the primary circuit inside which fission reactions occur. The reasons why the (LiF-BeF 2 -ThF 4 -UF 4 ) salt was chosen for the M.S.B.R. concept are examined; the physical, physicochemical and chemical properties of this salt are discussed with its interactions with the structural materials and its evolution in time. An important part of this volume is devoted to the continuous reprocessing of the active salt, the project designers having deemed advisable to take advantage at best from the availability of a continuous purification, in a thermal breeding. The problem of tritium formation and distribution inside the reactor is also envisaged and the fundamentals of the chemistry of the secondary coolant salt are given. The solutions proposed are: the hydrogen scavenging of the primary circuit, a reduction in metal permeability by an oxyde layer deposition on the side in contact with the vapor, and tritium absorption through an isotope exchange with the hydroxifluoroborate [fr

  15. Fate and effects of esfenvalerate in agricultural ponds

    DEFF Research Database (Denmark)

    Samsøe-Petersen, L.; Gutavson, K.; Madsen, T.

    2001-01-01

    in enclosures in a natural lake and in the laboratory on surface (Cymatia coleoptrata) and sediment (Chironomus riparius) insects. The latter were used in sediment-plus-water and in water-only tests, measuring effects on emergence and mortality. The measurements in the artificial pond indicated exposure...

  16. Performance of municipal waste stabilization ponds in the Canadian Arctic

    DEFF Research Database (Denmark)

    Ragush, Colin M.; Schmidt, Jordan J.; Krkosek, Wendy H.

    2015-01-01

    The majority of small remote communities in the Canadian arctic territory of Nunavut utilize waste stabilization ponds (WSPs) for municipal wastewater treatment because of their relatively low capital and operational costs, and minimal complexity. New national effluent quality regulations have be...

  17. Performance Of The Akosombo Waste Stabilization Ponds In Ghana ...

    African Journals Online (AJOL)

    A study was conducted to determine the treatment performance of the Akosombo waste stabilization ponds and the effect of seasonal changes on the final effluent quality. The waste water quality parameters ... Une étude était entreprise pour déterminer le résultat de traitement de bassins de stabilisation du déchet d' ...

  18. Effect of sewage oxidation pond effluent on macroinvertebrate ...

    African Journals Online (AJOL)

    The influence on aquatic macroinvertebrates of sewage oxidation pond effluent discharge was investigated in a tropical forest stream in Ile-Ife, Nigeria. A total of 858 individual macroinvertebrates were collected. They belong to 8 taxa which represent 5 orders. The number of taxa was low when compared to the findings in ...

  19. Food web interactions and nutrients dynamics in polyculture ponds

    NARCIS (Netherlands)

    Rahman, M.M.

    2006-01-01

    Artificial feed and fertilizers are the main sources of nutrients supporting fish growth in aquaculture ponds. The majority of the added nutrients are lost to the sediment, where they are no longer available for natural food production. By increasing resuspension of the sediment through the

  20. Assessment of water quality around Jaduguda uranium tailings ponds

    International Nuclear Information System (INIS)

    Mohanty, A.K.; Gurunadha Rao, V.V.S.; Ramesh, G.; Surinaidu, L.; Thama Rao, G.; Dhakate, R.; Sarangi, A.K.; Nair, R.N.

    2010-01-01

    The environmental impacts of uranium mining and milling activities are of great concern in many countries for the last three decades. These impacts range from the creation of massive stockpiles of radioactive and toxic waste rock and sand-like tailings to serious contamination of surface and groundwater with radioactive and toxic pollutants, and releases of conventional, toxic and radioactive air pollutants. Uranium mining is also associated with high concentrations of highly toxic heavy metals, which are a major source of surface and groundwater contamination. Depending upon the hydraulic properties of the fractures involved, contaminated ground water may be transported many miles from its point of origin before feeding into an aquifer. Tailings pond may contaminate the groundwater regime by continuous seepage and leaching of radionuclides and other toxic metals due to interaction of rain water through the tailings ponds. The uranium milling and tailings pond operations were started at Jaduguda since 1968. A comprehensive geological and geophysical investigation has been carried out in the Jaduguda watershed covering the tailings ponds to understand the geohydrological characteristics of the region. High resolution electrical resistivity tomography (ERT) surveys have been carried out to delineate the aquifer geometry. Water quality analyses were carried out in three seasons covering from premonsoon to postmonsoon period during 2008-2009. Uranium concentrations have been observed in the dug wells, surface water and monitoring wells

  1. Sustainable aquaculture in ponds: Principles, practices and limits

    NARCIS (Netherlands)

    Bosma, R.H.; Verdegem, M.C.J.

    2011-01-01

    The global aquaculture production of crustaceans, shellfish and fish has to increase to satisfy the growing demand and also to compensate for the reduced capture from overexploited fisheries. Extending the area of brackish and fresh water ponds is constrained by the limited availability of land and

  2. Phytoplankton productivity in newly dug fish ponds within Lake ...

    African Journals Online (AJOL)

    The declining Lake Victoria fisheries resource led to a growing recognition of aquaculture as a source of livelihood to riparian communities. Finger ponds speculated to naturally stock fish during flooding and retain them during dry seasons were introduced within the lake's wetlands. In order to develop a

  3. Remediation of an oily leachate pond in Estonia.

    Science.gov (United States)

    Kriipsalu, Mait; Marques, Marcia; Hogland, William

    2005-12-01

    Until recent years, waste oil and oil-contaminated waters commonly ended up in landfills. At some dump sites, ponds of oily liquids and leachate were formed. To remediate such ponds, an interdisciplinary approach is now required, keeping costs at an affordable level, particularly in countries with changing economies. From 1974 to 1993, liquid oily wastes taken to the Laguja landfill, in Estonia, were disposed of in a pond with a surface area of 9800 m2. It was estimated that the pond contained 4500-6000 m3 of oily water and 3500 m3 of oil-containing bottom sediments. This study aimed at developing an environmentally sound and cost-effective method for remediation of the oily liquids, leachate and contaminated underlying sediment material, to meet the existing legal demands. It was concluded that treatment of contaminated water is well established and the procedures carried out to meet the regulatory demands achieved satisfactory results. However, regarding treatment of sediments it was concluded that legal and technological aspects, as well as monitoring procedures are not fully established and are usually underestimated. Laboratory investigations can provide valuable information in decision-making, and contribute to effective full-scale remediation planning.

  4. Interpretation of ponded infiltration data using numerical experiments

    Czech Academy of Sciences Publication Activity Database

    Dohnal, M.; Vogel, T.; Dušek, J.; Votrubová, J.; Tesař, Miroslav

    2016-01-01

    Roč. 64, č. 3 (2016), s. 289-299 ISSN 0042-790X Institutional support: RVO:67985874 Keywords : ponded infiltration experiment * two-parameter infiltration equation * three-dimensional axisymmetric dualcontinuum model * preferential flow Subject RIV: DA - Hydrology ; Limnology Impact factor: 1.654, year: 2016

  5. Science from the Pond up: Using Measurement to Introduce Inquiry

    Science.gov (United States)

    Demir, Abdulkadir; Schmidt, Frank; Abell, Sandra K.

    2010-01-01

    The authors engaged nonscience majors enrolled in an integrated science course with a prototype activity designed to change their mindset from cookbook to inquiry science. This article describes the activity, the Warm Little Pond, which helped students develop essential understanding of basic statistics, significant figures, and the idea that…

  6. Efficiency of aquatic macrophytes to treat Nile tilapia pond effluents

    Directory of Open Access Journals (Sweden)

    Henry-Silva Gustavo Gonzaga

    2006-01-01

    Full Text Available The effluents from fish farming can increase the quantity of suspended solids and promote the enrichment of nitrogen and phosphorus in aquatic ecosystems. In this context, the aim of this work was to evaluate the efficiency of three species of floating aquatic macrophytes (Eichhornia crassipes, Pistia stratiotes and Salvinia molesta to treat effluents from Nile tilapia culture ponds. The effluent originated from a 1,000-m² pond stocked with 2,000 male Nile tilapia Oreochromis niloticus. The treatment systems consisted of 12 experimental tanks, three tanks for each macrophyte species, and three control tanks (without plants. Water samples were collected from the: (i fish pond source water, (ii effluent from fish pond and (iii effluents from the treatment tanks. The following water variables were evaluated: turbidity, total and dissolved nitrogen, ammoniacal-N, nitrate-N, nitrite-N, total phosphorus and dissolved phosphorus. E. crassipes and P. stratiotes were more efficient in total phosphorus removal (82.0% and 83.3%, respectively and total nitrogen removal (46.1% and 43.9%, respectively than the S. molesta (72.1% total phosphorus and 42.7% total nitrogen and the control (50.3% total phosphorus and 22.8% total nitrogen, indicating that the treated effluents may be reused in the aquaculture activity.

  7. Fertilization of Earth Ponds. III: Effects on Benthic Macro ...

    African Journals Online (AJOL)

    Organic fertilizers in form of cow and chicken manure were applied in oligotrophic or unproductive pond water over a period of one year to stimulate the production of benthic macro invertebrates for the benefit of trout culture, while maintaining adequate water quality. Development of aquatic macrophytes during both ...

  8. Ecological behavior of plutonium and americium in a freshwater pond

    International Nuclear Information System (INIS)

    Emery, R.M.; Klopfer, D.C.; Garland, T.R.; Weimer, W.C.

    1975-03-01

    A Pu processing waste pond on the Hanford Reservation has been studied since mid-1973 to characterize the pond's limnology and determine the ecological behavior in this ecosystem. About 8.1 kg of Pu was reported to have been discharged into waste trenches leading to the pond. Mean ratios of isotopes in the sediments are 0.85 for 238 Pu to 239 240 Pu, 0.61 for 241 Am to 238 Pu, and 0.49 for 241 Am to 239 240 Pu. Levels of Pu and Am in the interstitial water range from 0.5 to 13 pCi/g (dry wt. of sediment). For 238 Pu in pond water the mean concentration is 0.007 pCi/l, for 239 240 Pu it is 0.002 pCi/l, and for 241 Am it is 1.08 pCi/l. The remaining biota had Pu and Am levels which were generally well below those of the sediments. (U.S.)

  9. Rice field for the treatment of pond aquaculture effluents | Wang ...

    African Journals Online (AJOL)

    We conducted an experiment to evaluate the efficiency of rice fields in treating pond aquaculture effluent and its responses to different fertilizer treatments. Four treatments was considered in the experiment: no rice planted as the control (CT); rice planted and no fertilizer input (RE); rice planted and a rate of approximately ...

  10. Prevalence and Mean Intensity of Ectoparasite Infections in Pond ...

    African Journals Online (AJOL)

    A cross sectional study was carried out between September 2007 and September 2008 to investigate the prevalence and mean intensity of ectoparasite infections on the gills and skin of Nile tilapia (Oreochromis niloticus) in Morogoro, Tanzania. A total of 229 fish from 19 ponds were studied. Trichodina spp. and ...

  11. Analysis of ultimate-heat-sink spray ponds. Technical report

    International Nuclear Information System (INIS)

    Codell, R.

    1981-08-01

    This report develops models which can be utilized in the design of certain types of spray ponds used in ultimate heat sinks at nuclear power plants, and ways in which the models may be employed to determine the design basis required by U.S. Nuclear Regulatory Commission Regulatory Guide 1.27

  12. Par Pond vegetation status summer 1995 - July survey descriptive summary

    International Nuclear Information System (INIS)

    Mackey, H.E. Jr.; Riley, R.S.

    1995-07-01

    A survey of the emergent shoreline aquatic plant, communities began in June 1995, three months after the refilling of Par Pond to approximately 200 feet (61 meters) above mean sea level, and continued with this July survey. Aquatic plant communities, similar to the pre-drawdown Par Pond communities, are becoming reestablished. Beds of maidencane (Panicum hemitomon), lotus (Nelumbo lutea), water lily (Nymphaea odorata), and watershield (Brasenia schreberi) are now extensive and well established. In addition, within isolated coves, extensive beds of water lilies and spike-rush (Eleocharis sp.) are common. Cattail occurrence has increased since refill, but large beds common to Par Pond prior to the drawdown have not formed. Invasion of willow (Salix sp.) and red maple (Acer rubrum) occurred along the lake shoreline during drawdown. The red maples along the present shoreline are beginning to show evidence of stress and mortality from flooding over the past four months. Some of the willows appear to be stressed as well. The loblolly pines (Pinus taeda), which were flooded in all but the shallow shoreline areas, are now dead. Future surveys are planned for the growing seasons of 1995, 1996, and 1997, along with the evaluation of satellite data for mapping the areal extent of the macrophyte beds of Par Pond

  13. Groundwater impact assessment report for the 284-WB Powerplant Ponds

    International Nuclear Information System (INIS)

    Alexander, D.J.; Johnson, V.G.; Lindsey, K.A.

    1993-09-01

    As required by the Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement Milestone M-17-00A), this report assesses the impact of wastewater discharged to the 284-WB Powerplant Ponds on groundwater quality. The assessment reported herein expands upon the initial analysis conducted between 1989 and 1990 for the Liquid Effluent Study Final Project Plan

  14. Rabbit droppings as an organic fertilizer in earthen ponds, to ...

    African Journals Online (AJOL)

    cntaganda

    Total nitrogen (TN) concentration increased in direct relation with time of manuring. It was observed that TN concentration in fishpond ..... tilapia from fertilized ponds with duck, chicken and goat manure in China,. Bangladesh and India (Quazi and Huque, 1991). In general, growth and production assessed for O. niloticus ...

  15. Culture Trials of Gymnarchus niloticus in Earthen and Concrete Ponds

    African Journals Online (AJOL)

    Culture trials of Gymnarchus niloticus in earthen and concrete pond was carried out. A total of 440 fingerlings of G. niloticus from Burutu River, Delta State, were collected. A total of 220 fingerlings were stocked in each of the receptacles. The fingerlings were fed with live artemia for two weeks and commercial feed of size ...

  16. Some chemical parameters of a fertilized productive pond | Nwamba ...

    African Journals Online (AJOL)

    There was no significant variation (P>0.05) in the conductivity (ionic content) of the pond water whether fertilized or unfertilized. The increased in the mean values of free carbon dioxide during the fertilized period was attributed to increased rate of decomposition of organic matter and a concomitant release of carbon dioxide.

  17. Thermal energy storage using chloride salts and their eutectics

    International Nuclear Information System (INIS)

    Myers, Philip D.; Goswami, D. Yogi

    2016-01-01

    Achieving the goals of the U.S. Department of Energy (DOE) Sunshot initiative requires (1) higher operating temperatures for concentrating solar power (CSP) plants to increase theoretical efficiency, and (2) effective thermal energy storage (TES) strategies to ensure dispatchability. Current inorganic salt-based TES systems in large-scale CSP plants generally employ molten nitrate salts for energy storage, but nitrate salts are limited in application to lower temperatures—generally, below 600 °C. These materials are sufficient for parabolic trough power plants, but they are inadequate for use at higher temperatures. At the higher operating temperatures achievable in solar power tower-type CSP plants, chloride salts are promising candidates for application as TES materials, owing to their thermal stability and generally lower cost compared to nitrate salts. In light of this, a recent study was conducted, which included a preliminary survey of chloride salts and binary eutectic systems that show promise as high temperature TES media. This study provided some basic information about the salts, including phase equilibria data and estimates of latent heat of fusion for some of the eutectics. Cost estimates were obtained through a review of bulk pricing for the pure salts among various vendors. This review paper updates that prior study, adding data for additional salt eutectic systems obtained from the literature. Where possible, data are obtained from the thermodynamic database software, FactSage. Radiative properties are presented, as well, since at higher temperatures, thermal radiation becomes a significant mode of heat transfer. Material compatibility for inorganic salts is another important consideration (e.g., with regard to piping and/or containment), so a summary of corrosion studies with various materials is also presented. Lastly, cost data for these systems are presented, allowing for meaningful comparison among these systems and other materials for TES

  18. Gamma emitting radionuclides of the Test Reactor Area leaching ponds

    International Nuclear Information System (INIS)

    Millard, J.B.; Whicker, F.W.; Markham, O.D.

    1978-01-01

    Radioactive leaching ponds adjacent to the Test Reactor Area (TRA) located on the Idaho National Engineering Laboratory (INEL) Site were investigated to determine the seasonal distribution and ecological behavior of gamma emitting radionuclides. The potential hazards to man and the environment were considered through the biological export of radioactive materials from the ponds. Both biotic and abiotic pond compartments were sampled. Fall and winter biomass estimates showed that benthic periphyton comprised 52%, macrophytes and littoral vegetation 35%, and seston 10% of the total for all biotic compartments. Concentrations and concentration factors (CFs) for fall and winter are presented for Cr-51, Co-60, Zr-95, I-131, Cs-137, Ba-140, and Ce-141. Concentrations and CFs ranged over seven orders of magnitude for the various nuclides and compartments. Seston and zooplankton had the highest concentrations followed by periphyton, sediment, macrophytes, littoral plants, willow, and filtered water. Arthropods had variable concentrations and CFs. Significant seasonal differences were observed for concentrations and CFs in seston, macrophytes, and littoral vegetation. A compartmental inventory of total gamma emitting activity accounted for 254 Ci (9.25 TBq) of the 731 Ci (24.8 TBq) estimated to remain in the ponds at the time of sampling. Filtered water and surface sediments contained 99% of the total radioactivity, while periphyton and seston had most of the remaining 1%. An estimate of the avian export rate of radioactivity from the TRA ponds showed that potentially harvestable mourning doves had the lowest rate with 0.02 μCi/y. External tissues of migratory waterfowl were found to contribute 90% of the total exported activity for all birds. The total avian export rate was estimated to be 1350 μCi/y during 1975

  19. Cooperativity of complex salt bridges

    OpenAIRE

    Gvritishvili, Anzor G.; Gribenko, Alexey V.; Makhatadze, George I.

    2008-01-01

    The energetic contribution of complex salt bridges, in which one charged residue (anchor residue) forms salt bridges with two or more residues simultaneously, has been suggested to have importance for protein stability. Detailed analysis of the net energetics of complex salt bridge formation using double- and triple-mutant cycle analysis revealed conflicting results. In two cases, it was shown that complex salt bridge formation is cooperative, i.e., the net strength of the complex salt bridge...

  20. [Studies on nitrogen, phosphorus and organic matter in ponds around Chaohu Lake].

    Science.gov (United States)

    Sun, Qing-ye; Ma, Xiu-ling; Yang, Gui-de; Chen, Zheng; Wu, Hong-lin; Xuan, Huai-xiang

    2010-07-01

    There are a lot of ponds around Chaohu Lake. According to location and runoff supply of ponds, the ponds are divided into three types: ponds inner vellage (PIV), ponds adjacent vellage (PAV) and ponds outer vellage (POV). The samples of water and sediment were collected from 136 ponds around Chaohu Lake and the contents of nitrogen, phosphorus and organic matter in water and sediments were analyzed in this study. The results showed that mean contents of total nitrogen (TN), NH4+ -N, NO3- -N, NO2- -N, total phosphorus (TP), soluble PO4(3-) -P and COD were 2.53, 0.65, 0.18, 0.02, 0.97, 0.38 and 51.58 mg x L(-1) in pond water, respectively; and mean contents of TN, NH4+ -N, NO3- -N, NO2- -N, TP, inorganic phosphorus (IP), organic phosphorus (OP) and loss of ignition (LOI) in pond sediment were 1575.36, 35.73, 13.30, 2.88, 933.19, 490.14, 414.75 mg x kg(-1) and 5.44%, respectively. The ponds of more than 90% presented eutrophication in the contents of total nitrogen and phosphorus in water. The contents of TN and NH4+ -N in water and sediment of PIV were significantly higher than that of POV. And the contents of inorganic nitrogen in pond water and sediment displayed a following order: NH4+ -N > NO3- -N > NO2- -N. Data analysis indicated that there was a significantly positive correlation between organic matter and total nitrogen and phosphorus in water and sediment. The nitrogen, phosphorus and organic matter in ponds mainly sourced farmlands and village land surface. The contents of nitrogen, phosphorus and organic matter in ponds were affected by location and runoff supply of ponds. By retaining nitrogen, phosphorus and organic matter in runoff, the ponds can effectively decrease nutrient content into Chaohu Lake.

  1. Understanding the biological activity of high rate algae ponds through the calculation of oxygen balances.

    Science.gov (United States)

    Arbib, Zouhayr; de Godos Crespo, Ignacio; Corona, Enrique Lara; Rogalla, Frank

    2017-06-01

    Microalgae culture in high rate algae ponds (HRAP) is an environmentally friendly technology for wastewater treatment. However, for the implementation of these systems, a better understanding of the oxygenation potential and the influence of climate conditions is required. In this work, the rates of oxygen production, consumption, and exchange with the atmosphere were calculated under varying conditions of solar irradiance and dilution rate during six months of operation in a real scale unit. This analysis allowed determining the biological response of these dynamic systems. The rates of oxygen consumption measured were considerably higher than the values calculated based on the organic loading rate. The response to light intensity in terms of oxygen production in the bioreactor was described with one of the models proposed for microalgae culture in dense concentrations. This model is based on the availability of light inside the culture and the specific response of microalgae to this parameter. The specific response to solar radiation intensity showed a reasonable stability in spite of the fluctuations due to meteorological conditions. The methodology developed is a useful tool for optimization and prediction of the performance of these systems.

  2. Discussion on the source survey method in a natural evaporation pond

    International Nuclear Information System (INIS)

    Dai Xiaoshu; Fan Chengrong; Fu Yunshan

    2014-01-01

    A natural evaporation pond intended to be decommissioned. The survey of the pond focused on investigating radioactive contamination distribution and estimating the total amount of deposits in the pond, in order to provide support for subsequent decommissioning activities. Based on the source survey in the pond, this paper introduced how to implement radiation measurements and sampling (such as water and sediment) in the water. The movable work platform was built on the pond to facilitate sampling and measurement. In addition, a sludge sampler had been designed so as to accurately determine the amount of sampling and its depth. This paper also described the distribution of sampling points. (authors)

  3. Inventory of vegetation and benthos in newly laid and natural ponds in Forsmark 2012

    International Nuclear Information System (INIS)

    Qvarfordt, Susanne; Wallin, Anders; Borgiel, Micke

    2013-01-01

    SKB plans to build a repository for the spent nuclear fuel. The repository is planned to be built in Forsmark and constitutes installations above and below ground. The building and operation of the construction will involve activities that might affect the nature in the area. The impact means, among other things, that a small water body, which today is a reproduction site for the red listed pool frog (Rana lessonae), will disappear. The lost locality for the pool frog has been compensated by creating four new ponds in the Forsmark area. This study is part of the follow-up of these new habitats. The aim is to describe the plant and animal communities in the ponds, and follow the succession, i.e. the development of the habitats. The study also includes two natural ponds that will serve as reference objects. The survey of vegetation and invertebrate fauna in the ponds was conducted in October 2012. The results show that the new ponds had low coverage of submersed vegetation and the species composition in the plant communities differed between the ponds. The reference ponds also had different plant communities, both in terms of species composition and coverage. This indicates that the species composition of the plant communities in the new ponds will likely depend on physical factors specific to the respective pond, but that higher vegetation coverage can be expected over time in all new ponds. The reference ponds had similar animal communities that differed from the animal communities in the new ponds. The similar species composition in the reference ponds, despite the variety of plant communities, suggests that similar animal communities are likely to develop in the new ponds, even if the plant communities continues to be different. Water chemical sampling has also been conducted in the ponds during 2012. A comparison of the inorganic environment (with regard to analysed ions) showed that the reference ponds had relatively similar ion compositions with little

  4. Bioaccumulation of heavy metals in fauna from wet detention ponds for stormwater runoff

    DEFF Research Database (Denmark)

    Stephansen, Diana; Nielsen, Asbjørn Haaning; Hvitved-Jacobsen, Thorkild

    2012-01-01

    Stormwater detention ponds remove pollutants e.g. heavy metals and nutrients from stormwater runoff. These pollutants accumulate in the pond sediment and thereby become available for bioaccumulation in fauna living in the ponds. In this study the bioaccumulation was investigated by fauna samples...... from 5 wet detention ponds for analyses of heavy metal contents. Five rural shallow lakes were included in the study to survey the natural occurrence of heavy metals in water-dwelling fauna. Heavy metal concentrations in water-dwelling fauna were generally found higher in wet detention ponds compared...

  5. Decontamination and decommissioning of the BORAX-V leach pond. Final report

    International Nuclear Information System (INIS)

    Smith, D.L.

    1985-01-01

    This report describes the decontamination and decommissioning (D and D) of the BORAX-V leach pond located at the Idaho National Engineering Laboratory (INEL). The leach pond became radioactively contaminated from the periodic discharge of low-level liquid waste during operation of the Boiling Water Reactor Experiments (BORAX) from 1954 to 1964. This report describes work performed to accomplish the D and D objectives of stabilizing the leach pond and preventing the spread of contamination. D and D of the BORAX-V leach pond consisted to backfilling the pond with clean soil, grading and seeding the area, and erecting a permanent marker to identify very low-level subsurface contamination

  6. Biosynthesis and characterization of polyhydroxyalkanoates produced by an extreme halophilic bacterium, Halomonas nitroreducens, isolated from hypersaline ponds.

    Science.gov (United States)

    Cervantes-Uc, J M; Catzin, J; Vargas, I; Herrera-Kao, W; Moguel, F; Ramirez, E; Rincón-Arriaga, S; Lizama-Uc, G

    2014-10-01

    Morphological, biochemical and genotypic characterization of a halophilic bacterium isolated from hypersaline ponds located at Las Coloradas (Río Lagartos, Yucatán, Mexico). Characterization of polymer produced by this strain was also performed. Twenty strains were isolated from water samples of salt ponds and selected based on both morphological features and their PHA storage capacity, which were determined by SEM and staining methods with Nile red and Nile blue, respectively; strains were also analysed by the fluorescence imaging technique. Among them, JCCOL25.8 strain showed the highest production of PHA's reason why phenotypic and genotypic characterization was performed; this strain was identified as Halomonas nitroreducens. Polymer produced by this strain was characterized by FTIR, DSC, GPC and EDX spectroscopy. Results indicated that the biosynthesized polymer was polyhydroxybutyrate (PHB) which had a melting peak at 170°C and a crystallinity percentage of about 36%. Based on phenotypic and genotypic aspects, JCCOL25.8 strain was identified as H. nitroreducens and it was capable to accumulate PHB. To our knowledge, there is only one study published on the biosynthesis of PHA's by H. nitroreducens strains, although the characterization of the obtained polymer was not reported. © 2014 The Society for Applied Microbiology.

  7. Fundamental Properties of Salts

    Energy Technology Data Exchange (ETDEWEB)

    Toni Y Gutknecht; Guy L Fredrickson

    2012-11-01

    Thermal properties of molten salt systems are of interest to electrorefining operations, pertaining to both the Fuel Cycle Research & Development Program (FCR&D) and Spent Fuel Treatment Mission, currently being pursued by the Department of Energy (DOE). The phase stability of molten salts in an electrorefiner may be adversely impacted by the build-up of fission products in the electrolyte. Potential situations that need to be avoided, during electrorefining operations, include (i) fissile elements build up in the salt that might approach the criticality limits specified for the vessel, (ii) electrolyte freezing at the operating temperature of the electrorefiner due to changes in the liquidus temperature, and (iii) phase separation (non-homogenous solution). The stability (and homogeneity) of the phases can be monitored by studying the thermal characteristics of the molten salts as a function of impurity concentration. Simulated salt compositions consisting of the selected rare earth and alkaline earth chlorides, with a eutectic mixture of LiCl-KCl as the carrier electrolyte, were studied to determine the melting points (thermal characteristics) using a Differential Scanning Calorimeter (DSC). The experimental data were used to model the liquidus temperature. On the basis of the this data, it became possible to predict a spent fuel treatment processing scenario under which electrorefining could no longer be performed as a result of increasing liquidus temperatures of the electrolyte.

  8. Groundwater monitoring plan for the Hanford Site 216-B-3 pond RCRA facility

    International Nuclear Information System (INIS)

    Barnett, D.B.; Chou, C.J.

    1998-06-01

    The 216-B-3 pond system was a series of ponds for disposal of liquid effluent from past Hanford production facilities. In operation since 1945, the B Pond system has been a RCRA facility since 1986, with Resource Conservation and Recovery Act (RCRA) interim-status groundwater monitoring in place since 1988. In 1994, discharges were diverted from the main pond, where the greatest potential for contamination was thought to reside, to the 3C expansion pond. In 1997, all discharges to the pond system were discontinued. In 1990, the B Pond system was elevated from detection groundwater monitoring to an assessment-level status because total organic halogens and total organic carbon were found to exceed critical means in two wells. Subsequent groundwater quality assessment failed to find any specific hazardous waste contaminant that could have accounted for the exceedances, which were largely isolated in occurrence. Thus, it was recommended that the facility be returned to detection-level monitoring

  9. Surface and subsurface soils at the Pond B dam: July 1998

    International Nuclear Information System (INIS)

    Halverson, N.V.

    1999-01-01

    Pond B, 685-13G, is an inactive reactor cooling impoundment built in 1961 on the Savannah River Site (SRS). Between 1961 and 1964, Pond B received R-Reactor cooling water discharges that were contaminated with 137 Cs, 90 Sr and plutonium. Though the pond has not been used since 1964, radionuclides from the contaminated cooling water remain in the water and in the surface sediments of the pond. The current proposal to fix and repair the Pond B dam structure includes installing a new drain system and monitoring equipment. The dam will be reinforced with additional previous material on the downstream face of the dam. The objectives of this report are to describe the sampling methodology used during the July 1998 sampling event at the downstream face of the Pond B dam and in Pond B, present the results of the sampling event, and compare, where possible, these results to related risk-based standards

  10. Solar Features - Solar Flares

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A solar flare is a short-lived sudden increase in the intensity of radiation emitted in the neighborhood of sunspots. For many years it was best monitored in the...

  11. Solar storms; Tormentas solares

    Energy Technology Data Exchange (ETDEWEB)

    Collaboration: Pereira Cuesta, S.; Pereira Pagan, B.

    2016-08-01

    Solar storms begin with an explosion, or solar flare, on the surface of the sun. The X-rays and extreme ultraviolet radiation from the flare reach the Earths orbit minutes later-travelling at light speed. The ionization of upper layers of our atmosphere could cause radio blackouts and satellite navigation errors (GPS). Soon after, a wave of energetic particles, electrons and protons accelerated by the explosion crosses the orbit of the Earth, and can cause real and significant damage. (Author)

  12. Molten salt breeder reactor

    International Nuclear Information System (INIS)

    Furukawa, Kazuo; Tsukada, Kineo; Nakahara, Yasuaki; Oomichi, Toshihiko; Oono, Hideo.

    1982-01-01

    Purpose: To simplify the structure, as well as improve the technical reliability and safety by the elimination of a proton beam entering window. Constitution: The nuclear reactor container main body is made of Hastelloy N and provided at the inner surface with two layers of graphite shields except for openings. An aperture was formed in the upper surface of the container, through which protons accelerated by a linear accelerator are directly entered to the liquid surface of molten salts such as 7LiF-BeF 2 -ThF 4 , 7LiF-NaF-ThF 4 , 7LiF-Rb-UF 4 , NaF-KF-UF 4 and the like. The heated molten salts are introduced by way of a pipeway into a heat exchanger where the heat is transferred to coolant salts and electric generation is conducted by way of heated steams. (Furukawa, Y.)

  13. Patterns of Assemblage Structure Indicate a Broader Conservation Potential of Focal Amphibians for Pond Management.

    Directory of Open Access Journals (Sweden)

    Elin Soomets

    Full Text Available Small freshwater ponds host diverse and vulnerable biotic assemblages but relatively few conspicuous, specially protected taxa. In Europe, the amphibians Triturus cristatus and Pelobates fuscus are among a few species whose populations have been successfully restored using pond restoration and management activities at the landscape scale. In this study, we explored whether the ponds constructed for those two target species have wider conservation significance, particularly for other species of conservation concern. We recorded the occurrence of amphibians and selected aquatic macro-invertebrates (dragonflies; damselflies; diving beetles; water scavenger beetles in 66 ponds specially constructed for amphibians (up to 8 years post construction and, for comparison, in 100 man-made ponds (created by local people for cattle or garden watering, peat excavation, etc. and 65 natural ponds in Estonia. We analysed nestedness of the species assemblages and its dependence on the environment, and described the co-occurrence patterns between the target amphibians and other aquatic species. The assemblages in all ponds were significantly nested, but the environmental determinants of nestedness and co-occurrence of particular species differed among pond types. Constructed ponds were most species-rich irrespective of the presence of the target species; however, T. cristatus was frequent in those ponds and rare elsewhere, and it showed nested patterns in every type of pond. We thus conclude that pond construction for the protected amphibians can serve broader habitat conservation aims in the short term. However, the heterogeneity and inconsistent presence of species of conservation concern observed in other types of ponds implies that long-term perspectives on pond management require more explicit consideration of different habitat and biodiversity values. We also highlight nestedness analysis as a tool that can be used for the practical task of selecting focal

  14. Molten salt reactor type

    International Nuclear Information System (INIS)

    1977-01-01

    This document is one of the three parts of a first volume devoted to the compilations of American data on the molten salt reactor concept. This part 'CIRCUITS' regroups under a condensed form - in French and using international units - the essential information contained in both basic documents of the American project for a molten-salt breeder power plant. This part is only dealing with things relating to the CEA-EDF workshop 'CIRCUITS'. It is not concerned with information on: the reactor and the moderator replacement, the primary and secondary salts, and the fuel salt reprocessing, that are dealt with in parts 'CORE' and 'CHEMISTRY' respectively. The possible evolutions in the data - and solutions - taken by the American designers for their successive projects (1970 to 1972) are shown. The MSBR power plant comprises three successive heat transfer circuits. The primary circuit (Hastelloy N), radioactive and polluted, containing the fuel salt, includes the reactor, pumps and exchangers. The secondary circuit (pipings made of modified Hastelloy N) contaminated in the exchanger, ensures the separation between the fuel and the fluid operating the turbo-alternator. The water-steam circuit feeds the turbine with steam. This steam is produced in the steam generator flowed by the secondary fluid. Some subsidiary circuits (discharge and storage of the primary and secondary salts, ventilation of the primary circuit ...) complete the three principal circuits which are briefly described. All circuits are enclosed inside the controlled-atmosphere building of the nuclear boiler. This building also ensures the biological protection and the mechanical protection against outer aggressions [fr

  15. The dispersal and impact of salt from surface storage piles the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Reith, C.C.; Louderbough, E.T.

    1986-01-01

    A comprehensive program of ecological studies occurs at the Waste Isolation Pilot Plant (WIPP) in an effort to detect and quantify impacts of excavated salt which is stored on the surface in two piles: one having originated in 1980, the other in 1984. Both piles are surrounded by berms which channel runoff to holding ponds, so nearly all dispersal is due to the resuspension, transport, and deposition of salt particles by wind. Ecological parameters which have been monitored since 1984 include: visual evidence (via photography), soil properties, microbial activity, leaf-litter decomposition, seedling emergence, plant foliar cover, and plant species diversity. These are periodically assessed at experimental plots near the salt piles, and at control plots several kilometers away

  16. 21 CFR 100.155 - Salt and iodized salt.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Salt and iodized salt. 100.155 Section 100.155 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION GENERAL Specific Administrative Rulings and Decisions § 100.155 Salt and iodized salt. (a) For the purposes of this section, the...

  17. Macroelements in the surface microlayer of water of urban ponds

    Directory of Open Access Journals (Sweden)

    Antonowicz Józef Piotr

    2016-03-01

    Full Text Available Analyses were conducted concerning the accumulation of four metals representing the group of macroelements, i.e. sodium, potassium, calcium and magnesium in two ponds located in the city of Słupsk. Water samples for chemical analyses were collected from the surface microlayer using a Garrett net. At the same time subsurface water samples were collected. Concentrations of metals were determined using a mass spectrometer. Generally, amounts of sodium, potassium, calcium and magnesium were similar in surface microlayer and subsurface water. Only in the case of potassium and calcium was low enrichment observed in the surface microlayer in one pond, while the greatest extent for magnesium enrichment was observed in the spring period.

  18. Properties of geopolymer binders prepared from milled pond ash

    Directory of Open Access Journals (Sweden)

    J. Temuujin

    2017-09-01

    Full Text Available Alkali-activated materials were prepared from pond ash from the Darkhan city (Mongolia thermal power station. This ash contains about 60 wt % X-ray amorphous material in addition to quartz, mullite, hematite and magnesioferrite, and presents significant storage problems since it is accumulating in large amounts and is a hazardous waste, containing 90–100 ppm of the heavy metals As, Pb and Cr, and about 800 ppm Sr. Alkali-activated materials synthesized from the as-received pond ash achieved compressive strengths of only 3.25 MPa. Reduction of the particle size by mechanical milling for up to 30 min progressively increases the compressive strength of the resulting alkali-activated geopolymer up to 15.4 MPa. Leaching tests indicate that the combination of milling and alkali treatment does not cause the release of the hazardous heavy metals from the product, making it suitable for construction applications.

  19. A Hydrodynamic Study of Davis Pond, Near New Orleans, LA

    Science.gov (United States)

    2008-08-01

    District 2004). This project will make the Barataria estuary a more prolific producer of oysters, shrimp, crab , and fish, as well as a major habitat...yards 0.9144 meters ERDC/CHL TR-08-11 1 1 Introduction The Davis Pond freshwater diversion project is a salinity -control structure located in St...Mathematical model of estuarial sediment transport. Technical Report D-77-12. Vicksburg, MS: U.S. Army Engineer Waterways Experiment Station

  20. Spray pond piping made from fiberglass-reinforced thermosetting resin

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    A method is presented for implementing requirements pertaining to the design, fabrication, and testing of fiberglass-reinforced thermosetting resin piping for spray pond applications. These requirements are given in 10 CFR Part 50, Section 50.55a and Apppendix A, Criterion 1. This guide applies to both light-water-cooled and gas-cooled reactors. Input has been provided by the Advisory Committee on Reactor Safeguards

  1. Pond culture of seaweed Sargassum hemiphyllum in southern China

    Science.gov (United States)

    Yu, Zonghe; Hu, Chaoqun; Sun, Hongyan; Li, Haipeng; Peng, Pengfei

    2013-03-01

    The seaweed Sargassum hemiphyllum is widely distributed throughout the coastal waters of Asia and has high commercial value. In recent years, its natural biomass has declined due to over-exploitation and environmental pollution. To seek for a feasible way to culture this seaweed efficiently, we designed a simple long-line system in a shrimp pond for the culture during winter, and the growth and nutritional composition of the seaweed were examined. Results show that the culture system was durable and flexible allowing S. hemiphyllum to grow vertically off the muddy bottom of the pond. Although the length of pondcultured S. hemiphyllum was inhibited by water depth, the weight-specific growth rate ((1.65±0.17)%/d) was nearly three times higher than that of wild plants ((0.62±0.19)%/d). The crude protein (6.92%±0.88%) and ash content (21.52%±0.07%) of the pond-cultured seaweed were significantly lower than those of the wild plants (9.38%±0.43% and 26.93%±0.07%, respectively); however, crude fat (1.01%±0.04%) was significantly higher than that of the wild plants (0.87%±0.02%). In addition, the nutritional composition of both pond-cultured and wild S. hemiphyllum was comparable to or even higher than those of other common seaweeds being used as food and/or aquaculture fodder. Future studies shall be focused on the impact of environmental parameters on its growth and nutritional composition.

  2. Chromate abatement in the Y-12 Plant's New Hope Pond

    International Nuclear Information System (INIS)

    DeMonbrum, J.R.; Muenzer, W.A.

    1975-01-01

    Results are reported from a 15-months field study that utilized four nonchromate-based water-treatment programs in 16 low-temperature (less than 100 0 F) cooling towers using corrosion and deposition studies, microbiological control, and plant effluent creek analyses as evaluation parameters. The study succeeded in bringing the chromate content of effluent of the New Hope Pond at the Oak Ridge Y-12 Plant to the limits established by the Environmental Protection Agency. (auth)

  3. High Temperature Fluoride Salt Test Loop

    Energy Technology Data Exchange (ETDEWEB)

    Aaron, Adam M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Cunningham, Richard Burns [Univ. of Tennessee, Knoxville, TN (United States); Fugate, David L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Holcomb, David Eugene [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kisner, Roger A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Peretz, Fred J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Robb, Kevin R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wilson, Dane F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Yoder, Jr, Graydon L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-12-01

    Effective high-temperature thermal energy exchange and delivery at temperatures over 600°C has the potential of significant impact by reducing both the capital and operating cost of energy conversion and transport systems. It is one of the key technologies necessary for efficient hydrogen production and could potentially enhance efficiencies of high-temperature solar systems. Today, there are no standard commercially available high-performance heat transfer fluids above 600°C. High pressures associated with water and gaseous coolants (such as helium) at elevated temperatures impose limiting design conditions for the materials in most energy systems. Liquid salts offer high-temperature capabilities at low vapor pressures, good heat transport properties, and reasonable costs and are therefore leading candidate fluids for next-generation energy production. Liquid-fluoride-salt-cooled, graphite-moderated reactors, referred to as Fluoride Salt Reactors (FHRs), are specifically designed to exploit the excellent heat transfer properties of liquid fluoride salts while maximizing their thermal efficiency and minimizing cost. The FHR s outstanding heat transfer properties, combined with its fully passive safety, make this reactor the most technologically desirable nuclear power reactor class for next-generation energy production. Multiple FHR designs are presently being considered. These range from the Pebble Bed Advanced High Temperature Reactor (PB-AHTR) [1] design originally developed by UC-Berkeley to the Small Advanced High-Temperature Reactor (SmAHTR) and the large scale FHR both being developed at ORNL [2]. The value of high-temperature, molten-salt-cooled reactors is also recognized internationally, and Czechoslovakia, France, India, and China all have salt-cooled reactor development under way. The liquid salt experiment presently being developed uses the PB-AHTR as its focus. One core design of the PB-AHTR features multiple 20 cm diameter, 3.2 m long fuel channels

  4. Long-term changes in pond permanence, size, and salinity in Prairie Pothole Region wetlands: The role of groundwater-pond interaction

    Science.gov (United States)

    LaBaugh, James W.; Rosenberry, Donald O.; Mushet, David M.; Neff, Brian; Nelson, Richard D.; Euliss, Ned H.

    2018-01-01

    Study RegionCottonwood Lake area wetlands, North Dakota, U.S.A.Study FocusFluctuations in pond permanence, size, and salinity are key features of prairie-pothole wetlands that provide a variety of wetland habitats for waterfowl in the northern prairie of North America. Observation of water-level and salinity fluctuations in a semi-permanent wetland pond over a 20-year period, included periods when the wetland occasionally was dry, as well as wetter years when the pond depth and surface extent doubled while volume increased 10 times.New hydrological insights for the study regionCompared to all other measured budget components, groundwater flow into the pond often contributed the least water (8–28 percent) but the largest amount (>90 percent) of specific solutes to the water and solute budgets of the pond. In drier years flow from the pond into groundwater represented > 10 percent of water loss, and in 1992 was approximately equal to evapotranspiration loss. Also during the drier years, export of calcium, magnesium, sodium, potassium, chloride, and sulfate by flow from the pond to groundwater was substantial compared with previous or subsequent years, a process that would have been undetected if groundwater flux had been calculated as a net value. Independent quantification of water and solute gains and losses were essential to understand controls on water-level and salinity fluctuations in the pond in response to variable climate conditions.

  5. to salt stress

    African Journals Online (AJOL)

    Tony

    2012-02-14

    Feb 14, 2012 ... 3Inner Mongolia Industrial Engineering Research, Center of University for Castor, Tongliao 028042, ... strengthen and improve salt stress tolerance in plants. .... 2 µl cDNA, 1 µl each of 4 µM forward and reverse primer, 0.2 µl.

  6. Molten salt reactor concept

    International Nuclear Information System (INIS)

    Sood, D.D.

    1980-01-01

    Molten salt reactor is an advanced breeder concept which is suited for the utilization of thorium for nuclear power production. This reactor is based on the use of solutions of uranium or plutonium fluorides in LiF-BeF 2 -ThF 4 as fuel. Unlike the conventional reactors, no external coolant is used in the reactor core and the fuel salt itself is circulated through heat exchangers to transfer the fission produced heat to a secondary salt (NaF-NaBF 4 ) for steam generation. A part of the fuel stream is continuously processed to isolate 233 Pa, so that it can decay to fissile 233 U without getting converted to 234 Pa, and for the removal of neutron absorbing fission products. This on-line processing scheme makes this reactor concept to achieve a breeding ratio of 1.07 which is the highest for any thermal breeder reactor. Experimental studies at the Bhabha Atomic Research Centre, Bombay, have established the use of plutonium as fuel for this reactor. This molten salt reactor concept is described and the work conducted at the Bhabha Atomic Research Centre is summarised. (auth.)

  7. Molten salt electrorefining method

    International Nuclear Information System (INIS)

    Tanaka, Hiroshi; Nakamura, Hitoshi; Shoji, Yuichi; Matsumaru, Ken-ichi.

    1994-01-01

    A molten cadmium phase (lower side) and a molten salt phase (upper side) are filled in an electrolytic bath. A basket incorporating spent nuclear fuels is inserted/disposed in the molten cadmium phase. A rotatable solid cathode is inserted/disposed in the molten salt phase. The spent fuels, for example, natural uranium, incorporated in the basket is dissolved in the molten cadmium phase. In this case, the uranium concentration in the molten salt phase is determined as from 0.5 to 20wt%. Then, electrolysis is conducted while setting a stirring power for stirring at least the molten salt phase of from 2.5 x 10 2 to 1 x 10 4 based on a reynolds number. Crystalline nuclei of uranium are precipitated uniformly on the surface of the solid cathode, and they grow into fine dendrites. With such procedures, since short-circuit between the cathode precipitates and the molten cadmium phase (anode) is scarcely caused, to improve the recovering rate of uranium. (I.N.)

  8. Borehole closure in salt

    International Nuclear Information System (INIS)

    Fuenkajorn, K.; Daemen, J.J.K.

    1988-12-01

    Constitutive law parameters are determined from salt behavior characterization experiments. The results are applied to predict creep (time-dependent) closure of boreholes in salt specimens subjected to various loading configurations. Rheological models (linear and nonlinear viscoelastic and viscoplastic models), empirical models, and physical theory models have been formulated from the results of uniaxial creep tests, strain and stress rate controlled uniaxial tests, constant strain rate triaxial tests, cyclic loading tests, and seismic velocity measurements. Analytical solutions for a thick-walled cylinder subjected to internal and external pressures and for a circular hole in an infinite plate subjected to a biaxial or uniaxial stressfield have been derived from each of the linear viscoelastic models and from one of the empirical laws. The experimental results indicate that the salt samples behave as an elastic-viscoplastic material. The elastic behavior tends to be linear and time-independent. The plastic deformation is time-dependent. The stress increment to strain rate increment ratio gradually decreases as the stress level increases. The transient potential creep law seems to give the simplest satisfactory governing equation describing the viscoplastic behavior of salt during the transient phase. 204 refs., 27 figs., 29 tabs

  9. Salt repository design approach

    International Nuclear Information System (INIS)

    Matthews, S.C.

    1983-01-01

    This paper presents a summary discussion of the approaches that have been and will be taken in design of repository facilities for use with disposal of radioactive wastes in salt formations. Since specific sites have yet to be identified, the discussion is at a general level, supplemented with illustrative examples where appropriate. 5 references, 1 figure

  10. Learning SaltStack

    CERN Document Server

    Myers, Colton

    2015-01-01

    If you are a system administrator who manages multiple servers, then you know how difficult it is to keep your infrastructure in line. If you've been searching for an easier way, this book is for you. No prior experience with SaltStack is required.

  11. Solar thermal repowering systems integration. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Dubberly, L. J.; Gormely, J. E.; McKenzie, A. W.

    1979-08-01

    This report is a solar repowering integration analysis which defines the balance-of-plant characteristics and costs associated with the solar thermal repowering of existing gas/oil-fired electric generating plants. Solar repowering interface requirements for water/steam and salt or sodium-cooled central receivers are defined for unit sizes ranging from 50 MWe non-reheat to 350 MWe reheat. Finally balance-of-plant cost estimates are presented for each of six combinations of plant type, receiver type and percent solar repowering.

  12. Real time fish pond monitoring and automation using Arduino

    Science.gov (United States)

    Harun, Z.; Reda, E.; Hashim, H.

    2018-03-01

    Investment and operating costs are the biggest obstacles in modernizing fish ponds in an otherwise very lucrative industry i.e. food production, in this region. Small-scale farmers running on small ponds could not afford to hire workers to man daily operations which usually consists of monitoring water levels, temperature and feeding fish. Bigger scale enterprises usually have some kinds of automation for water monitoring and replacement. These entities have to consider employing pH and dissolved oxygen (DO) sensors to ensure the health and growth of fish, sooner or later as their farms grow. This project identifies one of the sites, located in Malacca. In this project, water, temperature, pH and DO levels are measured and integrated with aerating and water supply pumps using Arduino. User could receive information at predetermined intervals on preferred communication or display gadgets as long as they have internet. Since integrating devices are comparatively not expensive; it usually consists of Arduino board, internet and relay frames and display system, farmer could source these components easily. A sample of two days measurements of temperature, pH and DO levels show that this farm has a high-quality water. Oxygen levels increases in the day as sunshine supports photosynthesis in the pond. With this integration system, farmer need not hire worker at their site, consequently drive down operating costs and improve efficiency.

  13. Interpretation of ponded infiltration data using numerical experiments

    Directory of Open Access Journals (Sweden)

    Dohnal Michal

    2016-09-01

    Full Text Available Ponded infiltration experiment is a simple test used for in-situ determination of soil hydraulic properties, particularly saturated hydraulic conductivity and sorptivity. It is known that infiltration process in natural soils is strongly affected by presence of macropores, soil layering, initial and experimental conditions etc. As a result, infiltration record encompasses a complex of mutually compensating effects that are difficult to separate from each other. Determination of sorptivity and saturated hydraulic conductivity from such infiltration data is complicated. In the present study we use numerical simulation to examine the impact of selected experimental conditions and soil profile properties on the ponded infiltration experiment results, specifically in terms of the hydraulic conductivity and sorptivity evaluation. The effect of following factors was considered: depth of ponding, ring insertion depth, initial soil water content, presence of preferential pathways, hydraulic conductivity anisotropy, soil layering, surface layer retention capacity and hydraulic conductivity, and presence of soil pipes or stones under the infiltration ring. Results were compared with a large database of infiltration curves measured at the experimental site Liz (Bohemian Forest, Czech Republic. Reasonably good agreement between simulated and observed infiltration curves was achieved by combining several of factors tested. Moreover, the ring insertion effect was recognized as one of the major causes of uncertainty in the determination of soil hydraulic parameters.

  14. Seal Formation Mechanism Beneath Animal Waste Holding Ponds

    Science.gov (United States)

    Cihan, A.; Tyner, J. S.; Wright, W. C.

    2005-12-01

    Infiltration of animal waste from holding ponds can cause contamination of groundwater. Typically, the initial flux from a pond decreases rapidly as a seal of animal waste particulates is deposited at the base of the pond. The purpose of this study was to investigate the mechanism of the seal formation. Twenty-four soil columns (10-cm diameter by 43-cm long) were hand-packed with sand, silty loam or clay soils. A 2.3 m column of dairy or swine waste was applied to the top of the each column. The leakage rate from each column was measured with respect to time to analyze the effect of seal formation on different soil textures and animal waste types. We tested our hypothesis that seal growth and the subsequent decrease of leachate production adheres to a filter cake growth model. Said model predicts that the cumulative leakage rate is proportional to the square root of time and to the square root of the height of the waste.

  15. Shrimp pond wastewater treatment using pyrolyzed chicken feather as adsorbent

    Science.gov (United States)

    Moon, Wei Chek; Jbara, Mohamad Hasan; Palaniandy, Puganeshwary; Yusoff, Mohd Suffian

    2017-10-01

    In this study, chicken feather fiber was used as a raw material to prepare a non-expensive adsorbent by pyrolysis without chemical activation. The main pollutants treated in this study were chemical oxygen demand (COD) and ammoniacal nitrogen (NH3-N) from shrimp pond wastewater containing high concentrations of nutrients, which caused the eutrophication phenomenon in adjacent water. Batch adsorption studies were performed to investigate the effect of pH (5-8), mass of adsorbent (0.5-3 g), and shaking time (0.5-2 h) on the removal efficiency of COD and NH3- N. Experimental results showed that the optimum conditions were as follows: pH 5, 0.5 g of adsorbent, and 0.5 h of shaking. Under these conditions, 34.01% and 40.47% of COD and NH3-N were removed, respectively, from shrimp pond wastewater. The adsorption processes were best described by the Langmuir isotherm model for COD and NH3-N removal, with maximum monolayer adsorption capacity of 36.9 and 7.24 mg/g for COD and NH3-N, respectively. The results proved that chicken feather could remove COD and NH3-N from shrimp pond wastewater. However, further studies on thermal treatment should be carried out to increase the removal efficiency of pyrolyzed chicken feather fiber.

  16. Heat transfer in melt ponds with convection and radiative heating: observationally-inspired modelling

    Science.gov (United States)

    Wells, A.; Langton, T.; Rees Jones, D. W.; Moon, W.; Kim, J. H.; Wilkinson, J.

    2016-12-01

    Melt ponds have key impacts on the evolution of Arctic sea ice and summer ice melt. Small changes to the energy budget can have significant consequences, with a net heat-flux perturbation of only a few Watts per square metre sufficient to explain the thinning of sea ice over recent decades. Whilst parameterisations of melt-pond thermodynamics often assume that pond temperatures remain close to the freezing point, recent in-situ observations show more complex thermal structure with significant diurnal and synoptic variability. We here consider the energy budget of melt ponds and explore the role of internal convective heat transfer in determining the thermal structure within the pond in relatively calm conditions with low winds. We quantify the energy fluxes and temperature variability using two-dimensional direct numerical simulations of convective turbulence within a melt pond, driven by internal radiative heating and surface fluxes. Our results show that the convective flow dynamics are modulated by changes to the incoming radiative flux and sensible heat flux at the pond surface. The evolving pond surface temperature controls the outgoing longwave emissions from the pond. Hence the convective flow modifies the net energy balance of a melt pond, modulating the relative fractions of the incoming heat flux that is re-emitted to the atmosphere or transferred downward into the sea ice to drive melt.

  17. Economic Evaluation and Overall Assessment of Water Harvesting Ponds based on Scorecard System: A Case Study

    Science.gov (United States)

    Dabral, P. P.; Kumar, Santosh; Kiku, Karmchand

    2017-12-01

    In the present study, an attempt has been made to carry out an economic analysis of three (03) water harvesting ponds situated in the district of Lakhimpur (Assam), India. Economic analysis was carried out using three important economic criteria, namely Benefit Cost Ratio (BCR), Net Present Worth (NPW) and the Internal Rate of Returns (IRR). Ponds of the study area were compared with adopting score card system. All the water harvesting ponds were found economically viable as the BCR was more than unity at 12% discount rate. Net present worth was the highest for the water harvesting pond of Radhapukheri Fish Seed Farm, Department of Fisheries, Govt. of Assam, Narayanpur and the least for water harvesting pond of St. Xavier's School, Harmoti. The IRR was found to be the highest (60%) for water harvesting ponds of St. Xavier's School, Harmoti followed by water harvesting pond of a farmer of Narayanpur (48%) and water harvesting pond of Radhapukheri Fish Seed Farm (19.2%).Water harvesting pond of Radhapukheri Fish Seed Farm, Narayanpur scored the highest score (84 marks) followed by water harvesting pond of a farmer of Narayanpur (80 marks) and St. Xavier's school, Harmoti (61 marks).

  18. Estimated hydrologic budgets of kettle-hole ponds in coastal aquifers of southeastern Massachusetts

    Science.gov (United States)

    Walter, Donald A.; Masterson, John P.

    2011-01-01

    Kettle-hole ponds in southeastern Massachusetts are in good hydraulic connection to an extensive coastal aquifer system that includes the Plymouth-Carver aquifer system on the mainland and aquifers underlying Cape Cod. The ponds receive water from, and contribute water to, the underlying glacial aquifer; ponds also receive water from precipitation and lose water to evaporation from the pond surface. Some ponds are connected to surface-water drainage systems and receive water from or contribute water to streams or adjacent wetlands. The Massachusetts Department of Environmental Protection currently (2011) is developing Total Maximum Daily Loads of phosphorus for the freshwater ponds in the region to maintain the health of pond ecosystems; the amounts and sources of water fluxes into and out of the ponds are important factors in determining the amount of phosphorus that can be assimilated into a pond. To assist in this effort, the U.S. Geological Survey used groundwater-flow models of the coastal aquifer system to estimate hydrologic budgets-including inflows and outflows from the aquifer system and adjacent streams and wetlands, and recharge from precipitation-for 425 ponds in southeastern Massachusetts.

  19. The effect of beaver ponds on water quality in rural coastal plain streams

    Science.gov (United States)

    Bason, Christopher W.; Kroes, Daniel; Brinson, Mark M.

    2017-01-01

    We compared water-quality effects of 13 beaver ponds on adjacent free-flowing control reaches in the Coastal Plain of rural North Carolina. We measured concentrations of nitrate, ammonium, soluble reactive phosphorus (SRP), and suspended sediment (SS) upstream and downstream of paired ponds and control reaches. Nitrate and SS concentrations decreased, ammonium concentrations increased, and SRP concentrations were unaffected downstream of the ponds and relative to the control reaches. The pond effect on nitrate concentration was a reduction of 112 ± 55 μg-N/L (19%) compared to a control-reach—influenced reduction of 28 ± 17 μg-N/L. The pond effect on ammonium concentration was an increase of 9.47 ± 10.9 μg-N/L (59%) compared to the control-reach—influenced reduction of 1.49 ± 1.37 μg-N/L. The pond effect on SS concentration was a decrease of 3.41 ± 1.68 mg/L (40%) compared to a control-reach—influenced increase of 0.56 ± 0.27 mg/L. Ponds on lower-order streams reduced nitrate concentrations by greater amounts compared to those in higher-order streams. Older ponds reduced SS concentrations by greater amounts compared to younger ponds. The findings of this study indicate that beaver ponds provide water-quality benefits to rural Coastal Plain streams by reducing concentrations of nitrate and suspended sediment.

  20. Effects of marsh pond terracing on coastal wintering waterbirds before and after Hurricane Rita.

    Science.gov (United States)

    O'Connell, Jessica L; Nyman, John A

    2011-11-01

    From February to March 2005-2006, we surveyed wintering waterbirds to test effects of terracing on coastal pond use before and after Hurricane Rita. Marsh terracing is intended to slow coastal marsh loss in the Chenier Plain by slowing marsh erosion and encouraging vegetation expansion. Terraces also increase marsh edge in ponds, possibly benefiting waterbirds. We monitored paired terraced and unterraced ponds in three sites within southwestern Louisiana's Chenier Plain. Waterbirds were 75% more numerous in terraced than unterraced ponds. Waterbird richness was similar among ponds when corrected for number of individuals, suggesting terracing increased bird density but did not provide habitat unique from unterraced ponds. Birds were 93% more numerous following Hurricane Rita, mostly due to an influx of migrating waterfowl. Year round residents were similar in number before and after Hurricane Rita. Resident richness did not differ among years after correcting for number of observed individuals. Wading and dabbling foragers were more abundant in terraced ponds and these two guilds represented 74% of birds observed. We detected no difference among ponds for other guilds, i.e., probing, aerial, and diving foragers. Increasing proportion of mash edge increased bird density disproportionately: On average ponds with 10% edge had 6 birds observed and ponds with 30% edge had 16 birds observed. Terraces increased habitat interspersion and were an effective tool for increasing numbers of wintering waterfowl and wading birds. The extent to which terraces were sustainable following hurricane forces is unknown.