Science.gov

Sample records for fresh water inflow

  1. Fresh Water Inflow and Oyster Productivity in Apalachicola Bay, FL (USA)

    EPA Science Inventory

    Apalachicola Bay lies at the mouth of the Apalachicola River, where seasonally variable freshwater inflows and shifting winds support an unusually productive and commercially important oyster fishery. While there is concern that upstream water withdrawals may impact the fishery,...

  2. Fresh oxygen for the Baltic Sea — An exceptional saline inflow after a decade of stagnation

    NASA Astrophysics Data System (ADS)

    Mohrholz, V.; Naumann, M.; Nausch, G.; Krüger, S.; Gräwe, U.

    2015-08-01

    The ecological state of the Baltic Sea depends crucially on sufficiently frequent, strong deep water renewal on the periodic deep water renewal events by inflow of oxygen rich saline water from the North Sea. Due to the strong density stratification these inflows are the only source for deep water ventilation. Since the early eighties of the last century the frequency of inflow events has dropped drastically from 5 to 7 major inflows per decade to only one inflow per decade. Wide spread anoxic conditions became the usual state in the central Baltic. The rare major Baltic inflow (MBI) events in 1993 and 2003 could interrupt the anoxic bottom conditions only temporarily. After more than 10 years without a major Baltic inflow events, in December 2014 a strong MBI brought large amounts of saline and well oxygenated water into the Baltic Sea. Based on observations and numerical modeling, the inflow was classified as one of the rare very strong events. The inflow volume and the amount of salt transported into the Baltic were estimated to be with 198 km3 and 4 Gt, respectively. The strength of the MBI exceeded considerably the previous 2003 event. In the list of the MBIs since 1880, the 2014 inflow is the third strongest event together with the MBI in 1913. This inflow event will most probably turn the entire Baltic deep water from anoxic to oxic conditions, with substantial spread consequences for marine life and biogeochemical cycles.

  3. Impact of inflow transport approximation on light water reactor analysis

    NASA Astrophysics Data System (ADS)

    Choi, Sooyoung; Smith, Kord; Lee, Hyun Chul; Lee, Deokjung

    2015-10-01

    The impact of the inflow transport approximation on light water reactor analysis is investigated, and it is verified that the inflow transport approximation significantly improves the accuracy of the transport and transport/diffusion solutions. A methodology for an inflow transport approximation is implemented in order to generate an accurate transport cross section. The inflow transport approximation is compared to the conventional methods, which are the consistent-PN and the outflow transport approximations. The three transport approximations are implemented in the lattice physics code STREAM, and verification is performed for various verification problems in order to investigate their effects and accuracy. From the verification, it is noted that the consistent-PN and the outflow transport approximations cause significant error in calculating the eigenvalue and the power distribution. The inflow transport approximation shows very accurate and precise results for the verification problems. The inflow transport approximation shows significant improvements not only for the high leakage problem but also for practical large core problem analyses.

  4. Fresh Water Content Variability in the Arctic Ocean

    NASA Technical Reports Server (NTRS)

    Hakkinen, Sirpa; Proshutinsky, Andrey

    2003-01-01

    Arctic Ocean model simulations have revealed that the Arctic Ocean has a basin wide oscillation with cyclonic and anticyclonic circulation anomalies (Arctic Ocean Oscillation; AOO) which has a prominent decadal variability. This study explores how the simulated AOO affects the Arctic Ocean stratification and its relationship to the sea ice cover variations. The simulation uses the Princeton Ocean Model coupled to sea ice. The surface forcing is based on NCEP-NCAR Reanalysis and its climatology, of which the latter is used to force the model spin-up phase. Our focus is to investigate the competition between ocean dynamics and ice formation/melt on the Arctic basin-wide fresh water balance. We find that changes in the Atlantic water inflow can explain almost all of the simulated fresh water anomalies in the main Arctic basin. The Atlantic water inflow anomalies are an essential part of AOO, which is the wind driven barotropic response to the Arctic Oscillation (AO). The baroclinic response to AO, such as Ekman pumping in the Beaufort Gyre, and ice meldfreeze anomalies in response to AO are less significant considering the whole Arctic fresh water balance.

  5. Simulation Of Mine Water Inflow: Case Study Of The Štavalj Coal Mine (Southwestern Serbia)

    NASA Astrophysics Data System (ADS)

    Miladinović, Branko; Vakanjac, Vesna Ristić; Bukumirović, Dragomir; Dragišić, Veselin; Vakanjac, Boris

    2015-12-01

    The inflow of mine water to mining operations is often caused by random events such as precipitation. Consequently, the mine water inflow regime can be defined as a function of random events applying the theory of random processes. Regression models of the multiple linear correlation type have been used to simulate the inflow of mine water into mining operations, produce short-range predictions and facilitate rapid response inside the mine. The significance of such models lies in the ability to simulate and predict the consequences (mine water inflow), caused by events of a random nature (meteorological parameters: precipitation and air temperature). The presented prognostic models have been calibrated for mine water inflow to the Štavalj Coal Mine in southwestern Serbia. Mathematical dependencies were defined based on daily mine water inflow rates recorded during the period from 2003 to 2011, which can be used to generate short-range (1-7 day) predictions of mean daily mine water inflow rates to the Štavalj Coal Mine. A strong correlation (coefficient of correlation r = 0.93, Sig. = 0.00) was derived for the one-day forecast. The coefficients of correlation for predictions of mean daily mine water inflow rates related to time periods of two, three...seven days gradually declined to 0.63 (7-day mean daily inflow rate).

  6. DISPERSIBILITY OF CRUDE OIL IN FRESH WATER

    EPA Science Inventory

    The effects of surfactant composition on the ability of chemical dispersants to disperse crude oil in fresh water were investigated. The objective of this research was to determine whether effective fresh water dispersants can be designed in case this technology is ever consider...

  7. The MEDESS-GIB database: tracking the Atlantic water inflow

    NASA Astrophysics Data System (ADS)

    Sotillo, M. G.; Garcia-Ladona, E.; Orfila, A.; Rodríguez-Rubio, P.; Maraver, J. C.; Conti, D.; Padorno, E.; Jiménez, J. A.; Capó, E.; Pérez, F.; Sayol, J. M.; de los Santos, F. J.; Amo, A.; Rietz, A.; Troupin, C.; Tintore, J.; Álvarez-Fanjul, E.

    2015-11-01

    On 9 September 2014, an intensive drifter deployment was carried out in the Strait of Gibraltar. In the frame of the EU MED Program MEDESS-4MS, the MEDESS-GIB experiment consisted of the deployment of 35 satellite tracked drifters, mostly of CODE-type, equipped with temperature sensor sampling at a rate of 30 min. Drifters were distributed along and on both sides of the Strait of Gibraltar. The MEDESS-GIB deployment plan was designed as to ensure quasi-synoptic spatial coverage. To this end, 4 boats covering an area of about 680 NM2 in 6 h were coordinated. As far as authors know, this experiment is the most important exercise in the area in terms of number of drifters released. Collected satellite-tracked data along drifter trajectories have been quality controlled and processed to build the here presented MEDESS-GIB database. This paper reports the MEDESS-GIB dataset that comprises drifter trajectories, derived surface currents and in situ SST measurements collected along the buoys tracks. This series of data is available through the PANGAEA (Data Publisher for Earth and Environmental Science) repository, with the following doi:10.1594/PANGAEA.853701. Likewise, the MEDESS-GIB data will be incorporated as part of the Copernicus Marine historical products. The MEDESS-GIB dataset provides a complete Lagrangian view of the surface inflow of Atlantic waters through the Strait of Gibraltar and thus, very useful data for further studies on the surface circulation patterns in the Alboran Sea, and their links with one of the most energetic Mediterranean Sea flows: the Algerian Current.

  8. The MEDESS-GIB database: tracking the Atlantic water inflow

    NASA Astrophysics Data System (ADS)

    García Sotillo, Marcos; Garcia-Ladona, Emilio; Orfila, Alejandro; Rodríguez-Rubio, Pablo; Cristobal Maraver, José; Conti, Daniel; Padorno, Elena; Jiménez, José Antonio; Capó, Este; Pérez, Fernando; Sayol, Juan Manuel; de los Santos, Francisco Javier; Amo, Arancha; Rietz, Ana; Troupin, Charles; Tintore, Joaquín; Álvarez-Fanjul, Enrique

    2016-03-01

    On 9 September 2014, an intensive drifter deployment was carried out in the Strait of Gibraltar. In the frame of the MEDESS-4MS Project (EU MED Program), the MEDESS-GIB experiment consisted of the deployment of 35 satellite tracked drifters, mostly of CODE-type, equipped with temperature sensor sampling at a rate of 30 min. Drifters were distributed along and on both sides of the Strait of Gibraltar. The MEDESS-GIB deployment plan was designed as to ensure quasi-synoptic spatial coverage. To this end, four boats covering an area of about 680 NM2 in 6 h were coordinated. As far as these authors know, this experiment is the most important exercise in the area in terms of number of drifters released. Collected satellite-tracked data along drifter trajectories have been quality controlled and processed to build the presented MEDESS-GIB database. This paper reports the MEDESS-GIB data set that comprises drifter trajectories, derived surface currents and in situ SST measurements collected along the buoys tracks. This series of data is available through the PANGAEA (Data Publisher for Earth and Environmental Science) repository, with the following doi:10.1594/PANGAEA.853701. Likewise, the MEDESS-GIB data will be incorporated as part of the Copernicus Marine historical products. The MEDESS-GIB data set provides a complete Lagrangian view of the surface inflow of Atlantic waters through the Strait of Gibraltar and thus, very useful data for further studies on the surface circulation patterns in the Alboran Sea, and their links with one of the most energetic Mediterranean Sea flows: the Algerian Current.

  9. Dispersibility of crude oil in fresh water.

    PubMed

    Wrenn, B A; Virkus, A; Mukherjee, B; Venosa, A D

    2009-06-01

    The effects of surfactant composition on the ability of chemical dispersants to disperse crude oil in fresh water were investigated. The objective of this research was to determine whether effective fresh water dispersants can be designed in case this technology is ever considered for use in fresh water environments. Previous studies on the chemical dispersion of crude oil in fresh water neither identified the dispersants that were investigated nor described the chemistry of the surfactants used. This information is necessary for developing a more fundamental understanding of chemical dispersion of crude oil at low salinity. Therefore, we evaluated the relationship between surfactant chemistry and dispersion effectiveness. We found that dispersants can be designed to drive an oil slick into the freshwater column with the same efficiency as in salt water as long as the hydrophilic-lipophilic balance is optimum.

  10. Establishing the Global Fresh Water Sensor Web

    NASA Technical Reports Server (NTRS)

    Hildebrand, Peter H.

    2005-01-01

    This paper presents an approach to measuring the major components of the water cycle from space using the concept of a sensor-web of satellites that are linked to a data assimilation system. This topic is of increasing importance, due to the need for fresh water to support the growing human population, coupled with climate variability and change. The net effect is that water is an increasingly valuable commodity. The distribution of fresh water is highly uneven over the Earth, with both strong latitudinal distributions due to the atmospheric general circulation, and even larger variability due to landforms and the interaction of land with global weather systems. The annual global fresh water budget is largely a balance between evaporation, atmospheric transport, precipitation and runoff. Although the available volume of fresh water on land is small, the short residence time of water in these fresh water reservoirs causes the flux of fresh water - through evaporation, atmospheric transport, precipitation and runoff - to be large. With a total atmospheric water store of approx. 13 x 10(exp 12)cu m, and an annual flux of approx. 460 x 10(exp 12)cu m/y, the mean atmospheric residence time of water is approx. 10 days. River residence times are similar, biological are approx. 1 week, soil moisture is approx. 2 months, and lakes and aquifers are highly variable, extending from weeks to years. The hypothesized potential for redistribution and acceleration of the global hydrological cycle is therefore of concern. This hypothesized speed-up - thought to be associated with global warming - adds to the pressure placed upon water resources by the burgeoning human population, the variability of weather and climate, and concerns about anthropogenic impacts on global fresh water availability.

  11. Searching for storm water inflows in foul sewers using fibre-optic distributed temperature sensing.

    PubMed

    Schilperoort, Rémy; Hoppe, Holger; de Haan, Cornelis; Langeveld, Jeroen

    2013-01-01

    A major drawback of separate sewer systems is the occurrence of illicit connections: unintended sewer cross-connections that connect foul water outlets from residential or industrial premises to the storm water system and/or storm water outlets to the foul sewer system. The amount of unwanted storm water in foul sewer systems can be significant, resulting in a number of detrimental effects on the performance of the wastewater system. Efficient removal of storm water inflows into foul sewers requires knowledge of the exact locations of the inflows. This paper presents the use of distributed temperature sensing (DTS) monitoring data to localize illicit storm water inflows into foul sewer systems. Data results from two monitoring campaigns in foul sewer systems in the Netherlands and Germany are presented. For both areas a number of storm water inflow locations can be derived from the data. Storm water inflow can only be detected as long as the temperature of this inflow differs from the in-sewer temperatures prior to the event. Also, the in-sewer propagation of storm and wastewater can be monitored, enabling a detailed view on advection.

  12. Modelling the impact of Black Sea water inflow on the North Aegean Sea hydrodynamics

    NASA Astrophysics Data System (ADS)

    Tzali, Margarita; Sofianos, Sarantis; Mantziafou, Anneta; Skliris, Nikolaos

    2010-06-01

    The impact of the Black Sea Water (BSW) inflow on the circulation and the water mass characteristics of the North Aegean Sea is investigated using a high-resolution 3D numerical model. Four climatological numerical experiments are performed exploring the effects of the exchange amplitude at the Dardanelles Straits in terms of the mean annual volume exchanged and the amplitude of its seasonal cycle. Larger inflow of low salinity BSW influences the water characteristics of the whole basin. The largest salinity reduction is encountered in the upper layers of the water column, and the most affected region is the northeastern part of the basin. The winter insulation character of the BSW layer (low-salinity layer) is reduced by the seasonal cycle of the inflow (minimum during winter). The maximum atmospheric cooling coincides with the minimum BSW inflow rate, weakening the vertical density gradients close to the surface and thus facilitating the vertical mixing. The inflow rate of BSW into the North Aegean Sea constitutes an essential factor for the circulation in the basin. Increased inflow rate results into considerably higher kinetic energy, stronger circulation and reinforcement of the mesoscale circulation features. Although the position of the front between BSW and waters of Levantine origin does not vary significantly with the intensity of the BSW inflow rate, the flow along the front becomes stronger and more unstable as the inflow rate increases, forming meanders and rings. The changes in the intensity of BSW inflow rate overpower the wind and thermohaline forcing and largely determine the general circulation of the North Aegean Sea.

  13. Model simulation of inflow water to the Baltic Sea based on ¹²⁹I.

    PubMed

    Yi, P; Chen, X G; Bao, D X; Qian, R Z; Aldahan, A; Tian, F Y; Possnert, G; Bryhn, A C; Gu, T F; Hou, X L; He, P; Yu, Z B; Wang, B

    2013-12-01

    The semi-enclosed Baltic Sea represents a vital economic and recreational resource for more than 90 million people inhabiting its coasts. Extensive contamination of this sea by a variety of anthropogenic pollutants has raised the concern of the people in the region. Quantifying seawater inflow is crucial for estimating potential environmental risks as well as to find the best remedial strategy. We present here a model to estimate water inflow from the North Sea to the Baltic Sea by utilizing ¹²⁹I as a tracer. The results predicted inflow range of 230-450 km³/y with best fit value around 330 km³/y from the North Sea to the Baltic Sea during 1980-1999. Despite limited time series data on ¹²⁹I, the model presented here demonstrates a new management tool for the Baltic Sea to calculate inflow water compared to conventional methods (such as salinity, temperature and hydrographic models).

  14. Methods for Chemical Analysis of Fresh Waters.

    ERIC Educational Resources Information Center

    Golterman, H. L.

    This manual, one of a series prepared for the guidance of research workers conducting studies as part of the International Biological Programme, contains recommended methods for the analysis of fresh water. The techniques are grouped in the following major sections: Sample Taking and Storage; Conductivity, pH, Oxidation-Reduction Potential,…

  15. Estimating ground-water inflow to lakes in central Florida using the isotope mass-balance approach

    USGS Publications Warehouse

    Sacks, Laura A.

    2002-01-01

    The isotope mass-balance approach was used to estimate ground-water inflow to 81 lakes in the central highlands and coastal lowlands of central Florida. The study area is characterized by a subtropical climate and numerous lakes in a mantled karst terrain. Ground-water inflow was computed using both steady-state and transient formulations of the isotope mass-balance equation. More detailed data were collected from two study lakes, including climatic, hydrologic, and isotopic (hydrogen and oxygen isotope ratio) data. For one of these lakes (Lake Starr), ground-water inflow was independently computed from a water-budget study. Climatic and isotopic data collected from the two lakes were similar even though they were in different physiographic settings about 60 miles apart. Isotopic data from all of the study lakes plotted on an evaporation trend line, which had a very similar slope to the theoretical slope computed for Lake Starr. These similarities suggest that data collected from the detailed study lakes can be extrapolated to the rest of the study area. Ground-water inflow computed using the isotope mass-balance approach ranged from 0 to more than 260 inches per year (or 0 to more than 80 percent of total inflows). Steady-state and transient estimates of ground-water inflow were very similar. Computed ground-water inflow was most sensitive to uncertainty in variables used to calculate the isotopic composition of lake evaporate (isotopic compositions of lake water and atmospheric moisture and climatic variables). Transient results were particularly sensitive to changes in the isotopic composition of lake water. Uncertainty in ground-water inflow results is considerably less for lakes with higher ground-water inflow than for lakes with lower ground-water inflow. Because of these uncertainties, the isotope mass-balance approach is better used to distinguish whether ground-water inflow quantities fall within certain ranges of values, rather than for precise

  16. Changes of near-bottom water properties in polish zone generated by the inflow 2014

    NASA Astrophysics Data System (ADS)

    Rak, Daniel

    2016-04-01

    Since 11 years, in winter 2014 for the first time large amount of water - more than 200 km3 (Morholtz, 2015), were pushed into the Baltic Sea from the North Sea. This process has been classified as a Major Baltic Inflow (MBI). The inflow water brought to the Baltic Proper large amounts of salt (4 Gt) and oxygen. Oxygen and salt-reach, dense inflow waters are a phenomenon increasingly rare, since the early 80s average occurrence is once per decade. Therefore, the number of measurements both the situation during the process and changes of the water properties after termination of driving forces are limited. Institute of Oceanology PAS observed inflow and changes taking place afterwards during 6 r/v Oceania's cruises in the period December 2014 - December 2015. Refreshing of the bottom layers occurred in the Bornholm Deep and Słupsk Furrow, but in the Gdańsk Deep there was no change in the anoxic layer. In the Bornholm Deep effects of increased amount of oxygen quickly vanished, depleting the concentration of oxygen at a rate of 1 mg/l within a month. The initial high oxygen content of the inflow water (approximately 10 mg/l) was reduced and after 10 months anaerobic conditions returned. In the Słupsk Furrow this process was five times slower than in the Bornholm Deep, rate of the oxygen concentration was 0.2 mg/l per month. At the same time bottom salinity in the Polish zone remained relatively high. In November 2015 appearance of the warm (12 °C) and oxygenated (6 mg/l) layer of water below the halocline in the Bornholm Deep was observed. This inflow resulted in lifting the halocline to a depth that allowed the dense waters to pass through the Słupsk Sill.

  17. Insight Into Sustainability of Fresh Water

    NASA Astrophysics Data System (ADS)

    Simonovic, S. P.

    2002-05-01

    Global modeling often assumes that water is not an issue on the macro scale. WorldWater system dynamics model has been developed for modeling global world water balance and capturing the dynamic character of main variables affecting water availability and use in the future. In spite of not being a novel approach, system dynamics offers (i) a new way for identifying factors that are affecting the future availability of fresh water and provides (ii) insight into the impacts of different development strategies on the future availability of fresh water. WorldWater simulations are clearly demonstrating the strong feedback relation between water availability and different aspects of world development. Results of numerous simulations are contradictory to the assumption made by many global modelers and do confirm that water is an issue on the global scale. Two major observations are made from early model simulations: (a) the use of clean water for dilution and transport of wastewater, if not dealt in other ways, imposes a major stress on the global world water balance; and (b) water use by different sectors is demonstrating quite different dynamics then predicted by classical forecasting tools and other water-models. Inherent linkages between water quantity and quality sectors with food, industry, persistent pollution, technology, and nonrenewable resources sectors of the model create shoot and collapse behavior in water use dynamics. This presentation is discussing a number of different water-related scenarios and their implications on the future water balance. In particular, two extreme scenarios (business as usual - named `Chaos', and unlimited desalination - named `Ocean') will be discussed. Based on the conclusions derived from these two extreme cases a set of more moderate and realistic scenarios (named `Conservation') is proposed.

  18. Groundwater infiltration, surface water inflow and sewerage exfiltration considering hydrodynamic conditions in sewer systems.

    PubMed

    Karpf, Christian; Hoeft, Stefan; Scheffer, Claudia; Fuchs, Lothar; Krebs, Peter

    2011-01-01

    Sewer systems are closely interlinked with groundwater and surface water. Due to leaks and regular openings in the sewer system (e.g. combined sewer overflow structures with sometimes reverse pressure conditions), groundwater infiltration and surface water inflow as well as exfiltration of sewage take place and cannot be avoided. In the paper a new hydrodynamic sewer network modelling approach will be presented, which includes--besides precipitation--hydrographs of groundwater and surface water as essential boundary conditions. The concept of the modelling approach and the models to describe the infiltration, inflow and exfiltration fluxes are described. The model application to the sewerage system of the City of Dresden during a flood event with complex conditions shows that the processes of infiltration, exfiltration and surface water inflows can be described with a higher reliability and accuracy, showing that surface water inflow causes a pronounced system reaction. Further, according to the simulation results, a high sensitivity of exfiltration rates on the in-sewer water levels and a relatively low influence of the dynamic conditions on the infiltration rates were found.

  19. Dynamic control of flood limited water level for reservoir operation by considering inflow uncertainty

    NASA Astrophysics Data System (ADS)

    Li, Xiang; Guo, Shenglian; Liu, Pan; Chen, Guiya

    2010-09-01

    SummaryAccording to the Chinese Flood Control Act, reservoir water levels generally are not allowed to exceed the flood limited water level (FLWL) during flood season in order to offer adequate storage for flood prevention. However, the operation rules based on the current FLWL have neglected meteorological and real-time flood forecasting information and give too much priority to low probability floods. For floodwater utilization, dynamic control of reservoir FLWL is a valuable and effective methodology to compromise between flood control and conservation for reservoir operation during the flood season. The dynamic control bound is a fundamental key element for implementing reservoir FLWL dynamic control operation. In this paper, a dynamic control operation model that considers inflow uncertainty, i.e. the inflow forecasting error and uncertainty of the flood hydrograph shape is proposed and developed. The model consists of three modules: the first one is a pre-release module, which is used to estimate the upper boundary of dynamic control bound on basis of inflow forecasting results; the second one is a refill operation module, which is used to retain recession flood, and the third one is a risk analysis module, which is used to assess flood risk. The acceptable flood control operation risk constraints and quantificational analysis methods are given, and the dynamic control bound of reservoir FLWL is estimated by using Monte Carlo simulation. The China's three gorges reservoir (TGR) is selected as a case study. A multiple-input single-output linear systematic model is chosen for inflow forecasting of the TGR, and the future inflows are derived from gauged records by assuming that the inflow forecasting error follows a normal distribution. The application results show that the dynamic control of reservoir FLWL can effectively increase hydropower generation and the floodwater utilization rate without increasing flood control risk.

  20. Global modeling of fresh surface water temperature

    NASA Astrophysics Data System (ADS)

    Bierkens, M. F.; Eikelboom, T.; van Vliet, M. T.; Van Beek, L. P.

    2011-12-01

    Temperature determines a range of water physical properties, the solubility of oxygen and other gases and acts as a strong control on fresh water biogeochemistry, influencing chemical reaction rates, phytoplankton and zooplankton composition and the presence or absence of pathogens. Thus, in freshwater ecosystems the thermal regime affects the geographical distribution of aquatic species through their growth and metabolism, tolerance to parasites, diseases and pollution and life history. Compared to statistical approaches, physically-based models of surface water temperature have the advantage that they are robust in light of changes in flow regime, river morphology, radiation balance and upstream hydrology. Such models are therefore better suited for projecting the effects of global change on water temperature. Till now, physically-based models have only been applied to well-defined fresh water bodies of limited size (e.g., lakes or stream segments), where the numerous parameters can be measured or otherwise established, whereas attempts to model water temperature over larger scales has thus far been limited to regression type of models. Here, we present a first attempt to apply a physically-based model of global fresh surface water temperature. The model adds a surface water energy balance to river discharge modelled by the global hydrological model PCR-GLOBWB. In addition to advection of energy from direct precipitation, runoff and lateral exchange along the drainage network, energy is exchanged between the water body and the atmosphere by short and long-wave radiation and sensible and latent heat fluxes. Also included are ice-formation and its effect on heat storage and river hydraulics. We used the coupled surface water and energy balance model to simulate global fresh surface water temperature at daily time steps on a 0.5x0.5 degree grid for the period 1970-2000. Meteorological forcing was obtained from the CRU data set, downscaled to daily values with ECMWF

  1. Hot water, fresh beer, and salt

    SciTech Connect

    Crawford, F.S. Physics Department, University of California, Berkeley, CA )

    1990-11-01

    In the hot chocolate effect'' the best musical scales (those with the finest tone quality, largest range, and best tempo) are obtained by adding salt to a glass of hot water supersaturated with air. Good scales can also be obtained by adding salt to a glass of freshly opened beer (supersaturated with CO{sub 2}) provided you first (a) get rid of much of the excess CO{sub 2} so as to produce smaller, hence slower, rising bubbles, and (b) get rid of the head of foam, which damps the standing wave and ruins the tone quality. Finally the old question, Do ionizing particles produce bubbles in fresh beer '' is answered experimentally.

  2. Power, fresh water, and food from cold, deep sea water.

    PubMed

    Othmer, D F; Roels, O A

    1973-10-12

    Many times more solar heat energy accumulates in the vast volume of warm tropic seas than that produced by all of our power plants. The looming energy crisis causes a renewal of interest in utilizing this stored solar heat to give, in addition to electric power, vast quantities of fresh water. Warm surface water, when evaporated, generates steam, to power a turbine, then fresh water when the steam is condensed by the cold water. A great increase in revenues over that from power and fresh water is shown by a substantial mariculture pilot plant. Deep sea water contains large quantities of nutrients. These feed algae which feed shellfish, ultimately shrimps and lobsters, in shallow ponds. Wastes grow seaweed of value; and combined revenues from desalination, power generation, and mariculture will give substantial profit. PMID:17777883

  3. Power, fresh water, and food from cold, deep sea water.

    PubMed

    Othmer, D F; Roels, O A

    1973-10-12

    Many times more solar heat energy accumulates in the vast volume of warm tropic seas than that produced by all of our power plants. The looming energy crisis causes a renewal of interest in utilizing this stored solar heat to give, in addition to electric power, vast quantities of fresh water. Warm surface water, when evaporated, generates steam, to power a turbine, then fresh water when the steam is condensed by the cold water. A great increase in revenues over that from power and fresh water is shown by a substantial mariculture pilot plant. Deep sea water contains large quantities of nutrients. These feed algae which feed shellfish, ultimately shrimps and lobsters, in shallow ponds. Wastes grow seaweed of value; and combined revenues from desalination, power generation, and mariculture will give substantial profit.

  4. [Relationship Between Agricultural Land and Water Quality of Inflow River in Erhai Lake Basin].

    PubMed

    Pang, Yan; Xiang, Song; Chu, Zhao-sheng; Xue, Li-qiang; Ye, Bi-bi

    2015-11-01

    We studied the relationship between agricultural land and water quality of inflow river in Erhai Lake Basin, by means of spatial and statistical analysis, from the perspective of comprehensive agricultural land and the area percentage of different types of agricultural land. The obtained results indicated that inflow water quality showed a significant spatial difference, the inflow TP pollution in the western inflow rivers of Erhai Basin was serious. The major pollution indicators in the northern and southern inflow rivers (except for D3) were organic matter and nitrogen. The area percentage of agricultural land had a significantly indicative effect on the water quality of inflow river. The area percentage of comprehensive agricultural land negatively correlated with permanganate index, NH4(+) -N, TN and TP contents in wet season, the correlation coefficients were - 0.859, - 0.565, - 0.693, - 0.181. It negatively correlated with permanganate index and NH4(+) -N content in dry season, the correlation coefficients were - 0.384, - 0.328. It had positive relationships with and TN, TP content in dry season, the correlation coefficients were 0.221 and 0.146. The area percentage of different types of agricultural land had an obviously indicative effect on the inflow water quality. Farmland positively correlated with TN and TP contents both in wet and dry seasons. The correlation coefficients between farmland and TN, TP were 0.252, 0.581 in rainy season and were 0.149, 0.511 in dry season. It had positive and negative relationships with permanganate index, NH4(+) -N content in wet season and dry season, respectively. The correlation coefficients between farmland and permanganate index, NH4(+) -N were 0.388, 0.053 in rainy season and were -0.137, -0.147 in dry season. Forest land exhibited an opposite performance to that of farmland. The correlation coefficients between forest land and TN, TP, permanganate index, NH4(+) -N were - 0.526, - 0.275, - 0.469, -0.155 in rainy

  5. Progress at Fresh Kills improving water quality

    SciTech Connect

    Londres, E.J.

    1991-06-01

    This paper reports that in December 1987, the federal district court in Nevada issued a consent order forcing New York City (NYC) to improve its handling of solid waste and reduce the discharge of solid waste into the surrounding waterway. Implementation of the consent order by NYC resulted in many improvements in the transport of solid waste from the Marine Transfer Station (MTS) to Fresh Kills Landfill. The end result was a marked reduction in solid waste discharge and an improvement in water quality along the New Jersey shore areas.

  6. Water flow in fractured rock masses: numerical modeling for tunnel inflow assessment

    NASA Astrophysics Data System (ADS)

    Gattinoni, P.; Scesi, L.; Terrana, S.

    2009-04-01

    Water circulation in rocks represents a very important element to solve many problems linked with civil, environmental and mining engineering. In particular, the interaction of tunnelling with groundwater has become a very relevant problem not only due to the need to safeguard water resources from impoverishment and from the pollution risk, but also to guarantee the safety of workers and to assure the efficiency of the tunnel drainage systems. The evaluation of the hydrogeological risk linked to the underground excavation is very complex, either for the large number of variables involved or for the lack of data available during the planning stage. The study is aimed to quantify the influence of some geo-structural parameters (i.e. discontinuities dip and dip direction) on the tunnel drainage process, comparing the traditional analytical method to the modeling approach, with specific reference to the case of anisotropic rock masses. To forecast the tunnel inflows, a few Authors suggest analytic formulations (Goodman et al., 1965; Knutsson et al., 1996; Ribacchi et al., 2002; Park et al., 2008; Perrochet et al., 2007; Cesano et al., 2003; Hwang et al., 2007), valid for infinite, homogeneous and isotropic aquifer, in which the permeability value is given as a modulus of equivalent hydraulic conductivity Keq. On the contrary, in discontinuous rock masses the water flow is strongly controlled by joints orientation, by their hydraulic characteristics and by rocks fracturing conditions. The analytic equations found in the technical literature could be very useful, but often they don't reflect the real phenomena of the tunnel inflow in rock masses. Actually, these equations are based on the hypothesis of homogeneous aquifer, and then they don't give good agreement for an heterogeneous fractured medium. In this latter case, the numerical modelling could provide the best results, but only with a detailed conceptual model of the water circulation, high costs and long

  7. Evaporation over fresh and saline water surfaces

    NASA Astrophysics Data System (ADS)

    Abdelrady, Ahmed; Timmermans, Joris; Vekerdy, Zoltan

    2013-04-01

    Evaporation over large water bodies has a crucial role in the global hydrological cycle. Evaporation occurs whenever there is a vapor pressure deficit between a water surface and the atmosphere, and the available energy is sufficient. Salinity affects the density and latent heat of vaporization of the water body, which reflects on the evaporation rate. Different models have been developed to estimate the evaporation process over water surfaces using earth observation data. Most of these models are concerned with the atmospheric parameters. However these models do not take into account the influence of salinity on the evaporation rate; they do not consider the difference in the energy needed for vaporization. For this purpose an energy balance model is required. Several energy balance models that calculate daily evapotranspiration exist, such as the surface energy balance system (SEBS). They estimate the heat fluxes by integration of satellite data and hydro-meteorological field data. SEBS has the advantage that it can be applied over a large scale because it incorporates the physical state of the surface and the aerodynamic resistances in the daily evapotranspiration estimation. Nevertheless this model has not used over water surfaces. The goal of this research is to adapt SEBS to estimate the daily evaporation over fresh and saline water bodies. In particular, 1) water heat flux and roughness of momentum and heat transfer estimation need to be updated, 2) upscaling to daily evaporation needs to be investigated and finally 3) integration of the salinity factor to estimate the evaporation over saline water needs to be performed. Eddy covariance measurements over the Ijsselmeer Lake (The Netherlands) were used to estimate the roughness of momentum and heat transfer at respectively 0.0002 and 0.0001 m. Application of these values over Tana Lake (freshwater), in Ethiopia showed latent heat to be in a good agreement with the measurements, with RMSE of 35.5 Wm-2and r

  8. [Microbial indicators and fresh water quality assessment].

    PubMed

    Briancesco, Rossella

    2005-01-01

    Traditionally, the microbiological quality of waters has been measured by the analysis of indicator microorganisms. The article reviews the sanitary significance of traditional indicators of faecal contamination (total coliforms, faecal coliforms and faecal streptococci) and points out their limits. For some characteristics Escherichia coli may be considered a more useful indicator then faecal coliforms and recently it has been included in all recent laws regarding fresh, marine and drinking water. A clearer taxonomic definition of faecal streptococci evidenced the difficulty into defining a specific standard methodology of enumeration and suggested the more suitable role of enterococci as indicator microorganisms. Several current laws require the detection of enterococci. The resistance of Clostridium perfringens spores may mean that they would serve as a useful indicator of the sanitary quality of sea sediments.

  9. Evapotranspiration and water balance of an anthropogenic coastal desert wetland: responses to fire, inflows and salinities

    USGS Publications Warehouse

    Glenn, Edward P.; Mexicano, Lourdes; Garcia-Hernandez, Jaqueline; Nagler, Pamela L.; Gomez-Sapiens, Martha M.; Tang, Dawei; Lomeli, Marcelo A.; Ramírez-Hernández, Jorge; Zamora-Arroyo, Francisco

    2013-01-01

    Evapotranspiration (ET) and other water balance components were estimated for Cienega de Santa Clara, an anthropogenic brackish wetland in the delta of the Colorado River in Mexico. The marsh is in the Biosphere Reserve of the Upper Gulf of California and Delta of the Colorado River, and supports a high abundance and diversity of wildlife. Over 95% of its water supply originates as agricultural drain water from the USA, sent for disposal in Mexico. This study was conducted from 2009 to 2011, before, during and after a trial run of the Yuma Desalting Plant in the USA, which will divert water from the wetland and replace it with brine from the desalting operation. The goal was to estimate the main components in the water budget to be used in creating management scenarios for this marsh. We used a remote sensing algorithm to estimate ET from meteorological data and Enhanced Vegetation Index values from the Moderate Resolution Imaging Spectrometer (MODIS) sensors on the Terra satellite. ET estimates from the MODIS method were then compared to results from a mass balance of water and salt inflows and outflows over the study period. By both methods, mean annual ET estimates ranged from 2.6 to 3.0 mm d−1, or 50 to 60% of reference ET (ETo). Water entered at a mean salinity of 2.6 g L−1 TDS and mean salinity in the wetland was 3.73 g L−1 TDS over the 33 month study period. Over an annual cycle, 54% of inflows supported ET while the rest exited the marsh as outflows; however, in winter when ET was low, up to 90% of the inflows exited the marsh. An analysis of ET estimates over the years 2000–2011 showed that annual ET was proportional to the volume of inflows, but was also markedly stimulated by fires. Spring fires in 2006 and 2011 burned off accumulated thatch, resulting in vigorous growth of new leaves and a 30% increase in peak summer ET compared to non-fire years. Following fires, peak summer ET estimates were equal to ETo, while in non-fire years peak ET was

  10. Downstream changes of water quality in a lowland river due to groundwater inflows.

    NASA Astrophysics Data System (ADS)

    Zieba, Damian; Bar-Michalczyk, Dominika; Kania, Jarosław; Malina, Grzegorz; Michalczyk, Tomasz; Rozanski, Kazimierz; Witczak, Stanislaw; Wachniew, Przemyslaw; Zurek, Anna J.

    2016-04-01

    The Kocinka catchment (ca. 250 km2) in southern Poland receives substantial inflows of groundwater from a major fissured-carbonate aquifer polluted with nitrates originating from agriculture and domestic sewage. The 40 km long Kocinka river reveals large spatial variations in physical and chemical water properties with large downstream changes of nitrate concentrations. Detailed longitudinal surveys of such water characteristics as nitrate concentration, water temperature, pH, electric conductivity, stable isotopic composition, tritium concentration were performed in order to identify and quantify groundwater inflows. The river gains groundwater down to the 25 km from the source and a looses water further downstream. The subsequent increase and decrease of nitrate concentration in the upper and middle reaches of the river are caused by inflows of the, respectively, polluted and non-polluted groundwaters. The range of such changes can be even five-fold while the drop of nitrate concentration along the semi natural, 18 km long, lower reach where the river is well connected to its riparian and hyporheic zones nitrate loss is of the order of 10%. More significant nitrate losses were observed in the dammed reaches and in a small reservoir in the upper part of the river. Results of the study have implications for identification of measures that can be undertaken to reduce nitrate export from the catchment. Because of the role of groundwater in river runoff reduction of nitrate loads to the aquifer should be primary objective. Acknowledgements. The work was carried out as part of the BONUS Soils2Sea project on groundwater system (http:/www.soils2sea.eu) financed by the European Commission 7 FP contract 226536 and the statutory funds of the AGH University of Science and Technology (project No.11.11.140.026 and 11.11.220.01).

  11. The influence of Black Sea Water inflow and its synoptic time-scale variability in the North Aegean Sea hydrodynamics

    NASA Astrophysics Data System (ADS)

    Mavropoulou, Apostolia-Maria; Mantziafou, Anneta; Jarosz, Ewa; Sofianos, Sarantis

    2016-02-01

    The exchange water fluxes between the Black Sea and the North Aegean Sea through the Dardanelles Strait constitute an essential factor for the general circulation of the region. The Black Sea Water (BSW) inflow to the Aegean plays an important role in the hydrography and circulation of the basin and can affect the North Aegean deep water formation processes. Numerical experiments evaluating the influence of the time-scale variability (synoptic and seasonal) and the seasonality (period of maximum/minimum) of the Black Sea Water inflow on the dynamics of the North Aegean basin were performed. The experiments were carried out for the period from August 2008 to October 2009, using observed upper and lower-layer fluxes from the Dardanelles Strait, high-resolution atmospheric forcing, and boundary conditions derived from an operational system (ALERMO). The large-scale spatial patterns of the circulation and the seasonal variability of the North Aegean circulation show that dynamics of the basin can effectively absorb most of the Black Sea Water inflow variability. The overall cyclonic circulation of the North Aegean Sea and the predominant cyclonic and anti-cyclonic features are robust and are little affected by the different lateral fluxes. However, differences in the seasonality of the BSW inflow have an important impact in the North Aegean water column structure, while the synoptic variability observed in the Black Sea Water inflow affects the kinetic energy of the basin and the pathway of the Black Sea Water plume.

  12. Compositions for depolluting fresh water and salt water bodies

    SciTech Connect

    Olivieri, R.; Degen, L.; Robertiello, A.

    1983-11-08

    Compositions are disclosed, which are adapted to depollute fresh and sea water bodies from crude oil and petroleum product pollution by microbial action. The growth of micro-organisms capable of metabolizing hydrocarbons is exalted by certain combination of nutrients, such as lecithin as a phosphorus source, hydantoins, amides allophanates, polyamines, acyl-ureas and esters of the hydantoic and allantoic acids as the nitrogen sources. Ureido-derivatives of amides are also contemplated as additional nutrients.

  13. Inflow, outflow, and water levels in Lake Michigan during the last part of the Wisconsin glaciation

    SciTech Connect

    Clayton, L.; Attig, J.W. ); Mickelson, D.M. . Dept. of Geology and Geophysics)

    1992-01-01

    Between about 14,000 and 10,000 B.P., water flowed to and from Lake Michigan through several channels connected with adjacent glacial lakes and the Mississippi basin. Inflow and outflow depend on lake-level fluctuations, but no known lake-level chronology for the Lake Michigan basin explains all the supposed facts. Several kinds of information can be use to construct such a chronology: elevations of beaches, elevations and locations of outlets, ice-margin positions, till stratigraphy, and glacial history relative to outlets and lake-sediment distribution. If the crustal rebound predicted by J.A. Clark (bracketed by glacial Lake Wisconsin and Door Peninsula water planes) is used as the basis for a lake-level chronology, lake elevations would have been much higher than previously recognized, beaches previously thought to be late glacial must be middle Holocene, and the predicted sequence of spillways from glacial Lake Oshkosh, in the Green Bay basin, to Lake Michigan seems incompatible with the till stratigraphy of the region. On the other hand, a hinge line model such as proposed by J.W. Goldthwait allows far less rebound than is required by their knowledge of present-day rebound and by the rebound interpreted from shore features of glacial Lake Wisconsin. Therefore major flaws exist in their understanding of the glacial chronology and stratigraphy, of the glacial lake deposits, or of the crustal rebound; the reconstructed of inflow and outflow will remain uncertain until these conflicts are resolved.

  14. Estimated water and nutrient inflows and outflows, Lake Cochituate, eastern Massachusetts, 1977-79

    USGS Publications Warehouse

    Gay, F.B.

    1984-01-01

    Streamflow was the major source of water and nutrients (nitrogen and phosphorus) to Lake Cochituate, followed by ground water, and then precipitation during April 1978 through March 1979. Compared to all sources during that period, streams contributed 7,217 million gallons (a little over 82 percent) of water, 63 ,000 pounds (between 50 and 60 percent) of nitrogen, and 3,000 pounds (94 percent) of phosphorus. A little over 60 percent of all the water that entered Lake Cochituate flowed from Fisk Pond. This single source transported about 38,000 pounds of nitrogen and 2,000 pounds of phosphorus. Ground-water inflow to Lake Cochituate occurs along its shoreline except at the north end of Lake Cochituate 's North Pond where natural seepage from the lake is occurring and at locations on the lake 's Middle and South Ponds where municipal wells induce infiltration of lake water amounting to 1,228 million gallons for that period. Discharge of ground water to the lake was estimated to range from 462 to 816 million gallons and transported from 31,000 to 55,000 pounds of nitrogen and from 46 to 82 pounds of phosphorus. Bulk precipitation was estimated to contribute about the same volume of water to the lake as ground water but double its phosphorus load. However, the load of nitrogen, 8000 pounds, from bulk precipitation was the smallest of any source. (USGS)

  15. Melting icebergs to produce fresh water and mechanical energy

    SciTech Connect

    Camirand, W.M.; Hautala, E.; Randall, J.M.

    1981-10-20

    Fresh water and mechanical energy are obtained from melting of icebergs. Warm surface seawater is contacted with a fluid, which is vaporized. The resulting vapor is used to generate mechanical energy and then is condensed by contacting it with cold melt water from the iceberg. The fluid is regenerated with a concomitant elevation in the temperature of the melt water. The warmer melt water is cycled to the body of the iceberg to facilitate its melting and produce additional cold melt water, which is apportioned as fresh water and water cycled to condense the aforesaid vapor. In an alternate embodiment of the invention warm seawater is evaporated at reduced pressure. Mechanical energy is generated from the vapor, which is then condensed by direct and intimate contact with cold melt water from the iceberg. The resultant fresh water is a mixture of condensed vapor and melt water from the iceberg and has a temperature greater than the cold melt water. This fresh water mixture is contacted with the body of the iceberg to further melt it; part of the cold melt water is separated as fresh water and the remainder is cycled for use in condensing the vapor from the warm surface seawater.

  16. Toward an Improved Understanding of the Global Fresh Water Budget

    NASA Technical Reports Server (NTRS)

    Hildebrand, Peter H.

    2005-01-01

    The major components of the global fresh water cycle include the evaporation from the land and ocean surfaces, precipitation onto the Ocean and land surfaces, the net atmospheric transport of water from oceanic areas over land, and the return flow of water from the land back into the ocean. The additional components of oceanic water transport are few, principally, the mixing of fresh water through the oceanic boundary layer, transport by ocean currents, and sea ice processes. On land the situation is considerably more complex, and includes the deposition of rain and snow on land; water flow in runoff; infiltration of water into the soil and groundwater; storage of water in soil, lakes and streams, and groundwater; polar and glacial ice; and use of water in vegetation and human activities. Knowledge of the key terms in the fresh water flux budget is poor. Some components of the budget, e.g. precipitation, runoff, storage, are measured with variable accuracy across the globe. We are just now obtaining precise measurements of the major components of global fresh water storage in global ice and ground water. The easily accessible fresh water sources in rivers, lakes and snow runoff are only adequately measured in the more affluent portions of the world. presents proposals are suggesting methods of making global measurements of these quantities from space. At the same time, knowledge of the global fresh water resources under the effects of climate change is of increasing importance and the human population grows. This paper provides an overview of the state of knowledge of the global fresh water budget, evaluating the accuracy of various global water budget measuring and modeling techniques. We review the measurement capabilities of satellite instruments as compared with field validation studies and modeling approaches. Based on these analyses, and on the goal of improved knowledge of the global fresh water budget under the effects of climate change, we suggest

  17. The regional steady interface between fresh water and salt water in a coastal aquifer

    NASA Astrophysics Data System (ADS)

    Kishi, Yosuke; Fukuo, Yoshiaki; Kakinuma, Tadao; Ifuku, Makoto

    1982-08-01

    First, a theoretical model is presented which is useful for determining the regional steady interface between fresh water and salt water under the appropriate boundary conditions for both confined and unconfined aquifers. This model is then applied to the confined groundwater in the estuary of the Naka River, Tokushima Prefecture, Japan, and the phenomenon of the seawater intrusion into the aquifer is analyzed. Boundary conditions of the confined aquifer and the parameters necessary for analysis are determined from the data. Calculations using a finite-element method are carried out in various cases, by changing the inflow SR or the total pumping amount Q of the groundwater in this alluvial plain. It is found that the region where salt water is intruding expands rapidly inland when SR approaches Q and vice versa. It is also found that the distributions of chloride ion concentration in groundwater calculated by this model with a simplified assumption are in fairly good agreement with the results observed in deep wells.

  18. Robustness Analysis of Regional Water Supply Portfolios using Synthetic Inflow Scenarios with Variable Drought Frequency

    NASA Astrophysics Data System (ADS)

    Herman, J. D.; Zeff, H. B.; Lamontagne, J. R.; Reed, P. M.; Characklis, G. W.

    2015-12-01

    Robustness analyses of water supply systems have moved toward exploratory simulation to discover scenarios in which existing or planned policies may fail to meet stakeholder objectives. Such assessments rely heavily on the choice of plausible future scenarios, which, in the case of drought management, requires sampling or generating a broad ensemble of reservoir inflows which do not necessarily reflect the historical record. Here we adapt a widely used synthetic streamflow generation method to adjust the frequency of low-flow periods, which can be related to impactful historical events from the perspective of decision makers. Specifically, the modified generation procedure allows the user to specify parameters n, p such that events with observed weekly non-exceedance frequency p appear in the synthetic scenario with approximate frequency np (i.e., the pth percentile flow occurs n times more frequently). Additionally, the generator preserves the historical autocorrelation of streamflow and its seasonality, as well as approximate multi-site correlation. Using model simulations from recent work in multi-objective urban drought portfolio planning in North Carolina, a region whose water supply faces both climate and population pressures, we illustrate the decision-relevant consequences caused by raising the frequency of low flows associated with the 2007-2008 drought. This method explores system performance under extreme events of increasing frequency prior to reconciling these findings with climate model projections, and thus can be used to support bottom-up robustness methods in water systems planning.

  19. Land use, water use, streamflow characteristics, and water-quality characteristics of the Charlotte Harbor inflow area, Florida

    USGS Publications Warehouse

    Hammett, K.M.

    1990-01-01

    Charlotte Harbor is a 270-square-mile estuarine system in west-central Florida. It is being subjected to increasing environmental stress by rapid population growth and development. By 2020, population in the inflow area may double, which will result in increased demands for freshwater and increased waste loads. The Charlotte Harbor inflow area includes about 4,685 square miles. The Myakka, the Peace, and the Caloosahatchee are the major rivers emptying into the harbor. About 70 percent of the land in these three river basins is used for agriculture and range. In the coastal basin around Charlotte Harbor, about 50 percent of the total land area is devoted to commercial or residential uses. Water use in the inflow area is about 565 million gallons per day, of which 59 percent is used for irrigation, 26 percent for industry, 11 percent for public supply, and 4 percent for rural supply. Total freshwater inflow from the three major rivers, the coastal area, and rainfall directly into Charlotte Harbor averages between 5,700 and 6,100 cubic feet per second, which is more than 3,500 million gallons per day. A trend analysis of about 50 years of streamflow data shows a statistically significant decreasing trend for the Peace River stations at Bartow, Zolfo Springs, and Arcadia. No significant trend has been observed in the Myakka or the Caloosahatchee River data. In the Peace River, the decrease in flow may be related to a long-term decline in the potentiometric surface of the underlying Floridan aquifer system, which resulted from ground-water withdrawals. It is not possible to determine whether the trend will continue. However, if it does continue at the same rate, then, except for brief periods of storm runoff, the Peace River at Zolfo Springs could be dry year-round in about 100 years. Of the 114 facilities permitted to discharge domestic or industrial effluent to waters tributary to Charlotte Harbor, 88 are in the Peace River basin. Phosphate ore and citrus processing

  20. Saline solutions: the quest for fresh water.

    PubMed

    Reuther, C G

    2000-02-01

    Despite steady advances in the technology, desalination remains one of the most expensive ways to produce potable water. But as water scarcity forces communities to find new sources of drinking water, scientists are developing innovations that may soon make desalination a reasonable option for many more communities. The newest approach to desalination is membrane systems, which include reverse osmosis and electrodialysis systems. Current research seeks to make these systems more effective and less likely to produce environmentally hazardous by-products. Many facilities use traditional distillation to desalinate water, and efforts are being made to combine membranes and distillation for more efficient systems.

  1. Saline solutions: the quest for fresh water.

    PubMed Central

    Reuther, C G

    2000-01-01

    Despite steady advances in the technology, desalination remains one of the most expensive ways to produce potable water. But as water scarcity forces communities to find new sources of drinking water, scientists are developing innovations that may soon make desalination a reasonable option for many more communities. The newest approach to desalination is membrane systems, which include reverse osmosis and electrodialysis systems. Current research seeks to make these systems more effective and less likely to produce environmentally hazardous by-products. Many facilities use traditional distillation to desalinate water, and efforts are being made to combine membranes and distillation for more efficient systems. PMID:10656867

  2. Recovering fresh water stored in saline limestone aquifers.

    USGS Publications Warehouse

    Merritt, M.L.

    1986-01-01

    Numerical modeling techniques are used to examine the hydrogeologic, design, and management factors governing the recovery efficiency of subsurface fresh-water storage. The modeling approach permitted many combinations of conditions to be studied. A sensitivity analysis was used that consisted of varying certain parameters while keeping constant as many other parameters or processes as possible. The results show that a loss of recovery efficiency resulted from: 1) processes causing mixing of injected fresh water with native saline water (hydrodynamic dispersion); 2) processes or conditions causing the irreversible displacement of the injected fresh water with respect to the well (buoyancy stratification and background hydraulic gradients); or 3) processes or procedures causing injection and withdrawal flow patterns to be dissimilar (dissimilar injection and withdrawal schedules in multiple-well systems). Other results indicated that recovery efficiency improved considerably during the first several successive cycles, provided that each recovery phase ended whgen the chloride concentration of withdrawn water exceeded established criteria for potability (usually 250 milligrams per liter). Other findings were that fresh water injected into highly permeable or highly saline aquifers would buoy rapidly with a deleterious effect on recovery efficiency. -Author

  3. Fog as a fresh-water resource: overview and perspectives.

    PubMed

    Klemm, Otto; Schemenauer, Robert S; Lummerich, Anne; Cereceda, Pilar; Marzol, Victoria; Corell, David; van Heerden, Johan; Reinhard, Dirk; Gherezghiher, Tseggai; Olivier, Jana; Osses, Pablo; Sarsour, Jamal; Frost, Ernst; Estrela, María J; Valiente, José A; Fessehaye, Gebregiorgis Mussie

    2012-05-01

    The collection of fog water is a simple and sustainable technology to obtain fresh water for afforestation, gardening, and as a drinking water source for human and animal consumption. In regions where fresh water is sparse and fog frequently occurs, it is feasible to set up a passive mesh system for fog water collection. The mesh is directly exposed to the atmosphere, and the foggy air is pushed through the mesh by the wind. Fog droplets are deposited on the mesh, combine to form larger droplets, and run down passing into a storage tank. Fog water collection rates vary dramatically from site to site but yearly averages from 3 to 10 l m(-2) of mesh per day are typical of operational projects. The scope of this article is to review fog collection projects worldwide, to analyze factors of success, and to evaluate the prospects of this technology. PMID:22328161

  4. Fog as a fresh-water resource: overview and perspectives.

    PubMed

    Klemm, Otto; Schemenauer, Robert S; Lummerich, Anne; Cereceda, Pilar; Marzol, Victoria; Corell, David; van Heerden, Johan; Reinhard, Dirk; Gherezghiher, Tseggai; Olivier, Jana; Osses, Pablo; Sarsour, Jamal; Frost, Ernst; Estrela, María J; Valiente, José A; Fessehaye, Gebregiorgis Mussie

    2012-05-01

    The collection of fog water is a simple and sustainable technology to obtain fresh water for afforestation, gardening, and as a drinking water source for human and animal consumption. In regions where fresh water is sparse and fog frequently occurs, it is feasible to set up a passive mesh system for fog water collection. The mesh is directly exposed to the atmosphere, and the foggy air is pushed through the mesh by the wind. Fog droplets are deposited on the mesh, combine to form larger droplets, and run down passing into a storage tank. Fog water collection rates vary dramatically from site to site but yearly averages from 3 to 10 l m(-2) of mesh per day are typical of operational projects. The scope of this article is to review fog collection projects worldwide, to analyze factors of success, and to evaluate the prospects of this technology.

  5. Fresh water and power from the sea

    NASA Astrophysics Data System (ADS)

    Thomas, Anthony; Hillis, David L.

    An experiment--the Heat and Mass Transfer Scoping Test Apparatus--was built to obtain design data for a larger test that will assess the technical feasibility of the open-cycle OTEC process. (This closed-cycle concept was successfully demonstrated in 1979.) The project is a joint effort between Argonne National Laboratory (ANL) and the Solar Energy Research Institute (SERI). The apparatus was erected at the Natural Energy Laboratory of Hawaii and became operational in the summer of 1987. It is used by both ANL and SERI to conduct open-cycle OTEC experiments. After initial debugging, it produced 350 gallons per hour of potable water having a salinity of 86 ppM, one-fifth that of local tap water available at the test site.

  6. Innovative Fresh Water Production Process for Fossil Fuel Plants

    SciTech Connect

    James F. Klausner; Renwei Mei; Yi Li; Jessica Knight; Venugopal Jogi

    2005-09-01

    This project concerns a diffusion driven desalination (DDD) process where warm water is evaporated into a low humidity air stream, and the vapor is condensed out to produce distilled water. Although the process has a low fresh water to feed water conversion efficiency, it has been demonstrated that this process can potentially produce low cost distilled water when driven by low grade waste heat. This report describes the annual progress made in the development and analysis of a Diffusion Driven Desalination (DDD) system. A dynamic analysis of heat and mass transfer demonstrates that the DDD process can yield a fresh water production of 1.03 million gallon/day by utilizing waste heat from a 100 MW steam power plant based on a condensing steam pressure of only 3 Hg. The optimum operating condition for the DDD process with a high temperature of 50 C and sink temperature of 25 C has an air mass flux of 1.5 kg/m{sup 2}-s, air to feed water mass flow ratio of 1 in the diffusion tower, and a fresh water to air mass flow ratio of 2 in the condenser. Operating at these conditions yields a fresh water production efficiency (m{sub fW}/m{sub L}) of 0.031 and electric energy consumption rate of 0.0023 kW-hr/kg{sub fW}. Throughout the past year, the main focus of the desalination process has been on the direct contact condenser. Detailed heat and mass transfer analyses required to size and analyze these heat and mass transfer devices are described. The analyses agree quite well with the current data. Recently, it has been recognized that the fresh water production efficiency can be significantly enhanced with air heating. This type of configuration is well suited for power plants utilizing air-cooled condensers. The experimental DDD facility has been modified with an air heating section, and temperature and humidity data have been collected over a range of flow and thermal conditions. It has been experimentally observed that the fresh water production rate is enhanced when air

  7. Low toxic corrosion inhibitors for aluminum in fresh water

    NASA Technical Reports Server (NTRS)

    Humphries, T. S.

    1978-01-01

    Combinations of chemical compounds that reportedly reduce the corrosion of aluminum in fresh water were evaluated. These included combinations of borates, nitrates, nitrites, phosphates, silicates, and mercaptobenzothiazole. Eight of fifty inhibitor combinations evaluated gave excellent corrosion protection and compared favorably with sodium chromate, which has generally been considered standard for many years.

  8. [Fresh water macroinvertebrates of Costa Rica I].

    PubMed

    Springer, Monika; Ramirez, Alonso; Hanson, Paul

    2010-12-01

    This is the first in a series of three volumes on the freshwater macroinvertebrates of Costa Rica. The present volume includes an introductory chapter summarizing the major types of freshwater environments, the biology of freshwater macroinvertebrates (habitats, food, respiration, osmoregulation, etc.), ecological and economic importance, conservation and a synopis of the major groups, followed by a simplified key. The next two chapters discuss collecting methods and biomonitoring. These are followed by chapters on mayflies (Ephemeroptera: 10 families), dragonflies (Odonata: 13 families), stoneflies (Plecoptera: 1 family) and caddisflies (Trichoptera: 15 families). Both in this volume and in those to follow, the chapters treating individual taxa include a summary of the natural history, importance, taxonomy, collecting methods, morphology and an illustrated key to the families; each family is discussed separately and an illustrated key to genera is provided; each chapter ends with a bibliography and a table listing all the genera with information on number of species, distribution, habitat and tolerance to water pollution. While the emphasis is on families and genera known from Costa Rica, additional taxa occurring elsewhere in Central America are mentioned. The present volume also includes numerous color plates of aquatic macroinvertebrates.

  9. Increased salinization of fresh water in the northeastern United States.

    PubMed

    Kaushal, Sujay S; Groffman, Peter M; Likens, Gene E; Belt, Kenneth T; Stack, William P; Kelly, Victoria R; Band, Lawrence E; Fisher, Gary T

    2005-09-20

    Chloride concentrations are increasing at a rate that threatens the availability of fresh water in the northeastern United States. Increases in roadways and deicer use are now salinizing fresh waters, degrading habitat for aquatic organisms, and impacting large supplies of drinking water for humans throughout the region. We observed chloride concentrations of up to 25% of the concentration of seawater in streams of Maryland, New York, and New Hampshire during winters, and chloride concentrations remaining up to 100 times greater than unimpacted forest streams during summers. Mean annual chloride concentration increased as a function of impervious surface and exceeded tolerance for freshwater life in suburban and urban watersheds. Our analysis shows that if salinity were to continue to increase at its present rate due to changes in impervious surface coverage and current management practices, many surface waters in the northeastern United States would not be potable for human consumption and would become toxic to freshwater life within the next century.

  10. Increased salinization of fresh water in the northeastern United States

    PubMed Central

    Kaushal, Sujay S.; Groffman, Peter M.; Likens, Gene E.; Belt, Kenneth T.; Stack, William P.; Kelly, Victoria R.; Band, Lawrence E.; Fisher, Gary T.

    2005-01-01

    Chloride concentrations are increasing at a rate that threatens the availability of fresh water in the northeastern United States. Increases in roadways and deicer use are now salinizing fresh waters, degrading habitat for aquatic organisms, and impacting large supplies of drinking water for humans throughout the region. We observed chloride concentrations of up to 25% of the concentration of seawater in streams of Maryland, New York, and New Hampshire during winters, and chloride concentrations remaining up to 100 times greater than unimpacted forest streams during summers. Mean annual chloride concentration increased as a function of impervious surface and exceeded tolerance for freshwater life in suburban and urban watersheds. Our analysis shows that if salinity were to continue to increase at its present rate due to changes in impervious surface coverage and current management practices, many surface waters in the northeastern United States would not be potable for human consumption and would become toxic to freshwater life within the next century. PMID:16157871

  11. INNOVATIVE FRESH WATER PRODUCTION PROCESS FOR FOSSIL FUEL PLANTS

    SciTech Connect

    James F. Klausner; Renwei Mei; Yi Li; Mohamed Darwish; Diego Acevedo; Jessica Knight

    2003-09-01

    This report describes the annual progress made in the development and analysis of a Diffusion Driven Desalination (DDD) system, which is powered by the waste heat from low pressure condensing steam in power plants. The desalination is driven by water vapor saturating dry air flowing through a diffusion tower. Liquid water is condensed out of the air/vapor mixture in a direct contact condenser. A thermodynamic analysis demonstrates that the DDD process can yield a fresh water production efficiency of 4.5% based on a feed water inlet temperature of only 50 C. An example is discussed in which the DDD process utilizes waste heat from a 100 MW steam power plant to produce 1.51 million gallons of fresh water per day. The main focus of the initial development of the desalination process has been on the diffusion tower. A detailed mathematical model for the diffusion tower has been described, and its numerical implementation has been used to characterize its performance and provide guidance for design. The analysis has been used to design a laboratory scale diffusion tower, which has been thoroughly instrumented to allow detailed measurements of heat and mass transfer coefficient, as well as fresh water production efficiency. The experimental facility has been described in detail.

  12. Tracking evolution of urban biogeochemical cycles: salinization of fresh water

    NASA Astrophysics Data System (ADS)

    Kaushal, S.; McDowell, W. H.; Wollheim, W. M.; Duan, S.; Gorman, J. K.; Haq, S.; Hohman, S.; Smith, R. M.; Mayer, P. M.

    2014-12-01

    The built environment often changes quickly in response to human activities, thus contributing to an evolution of stream chemistry over time. Depending upon development and management strategies, these changes can result in pulses and/or long-term trends. Here, we explore patterns of evolving salinization of fresh water over time, and we evaluate the potential water quality implications of fresh water salinization. We show that there has been global salinization of freshwater across urbanizing landscapes over a century. We also show that human-accelerated weathering in watersheds and river alkalinization can further influence regional rates of salinization (in addition to anthropogenic sources such as road salts, sewage leaks, etc.). Finally, we investigate how salinization of fresh water can impact stream sediment fluxes of carbon, nutrients, and sulfate in watersheds across a land use gradient at the Baltimore Long-Term Ecological Research (LTER) site. The impacts of salinization on mobilization and uptake of carbon, nutrients, and sulfate in streams warrant further consideration in water quality management strategies. Overall, we propose that salinization can be a "universal tracer" of watershed urbanization globally with major regional consequences for drinking water and evolution of biogeochemical cycles in freshwater ecosystems.

  13. Stable isotope estimates of evaporation: inflow and water residence time for lakes across the United States as a tool for national lake water quality assessments

    EPA Science Inventory

    Stable isotope ratios of water (delta18O and delta2H) can be very useful in large-scale monitoring programs because water samples are easy to collect and isotope ratios integrate information about basic hydrologic processes such as evaporation as a percentage of inflow (E/I) and ...

  14. INNOVATIVE FRESH WATER PRODUCTION PROCESS FOR FOSSIL FUEL PLANTS

    SciTech Connect

    James F. Klausner; Renwei Mei; Yi Li; Jessica Knight

    2004-09-01

    An innovative Diffusion Driven Desalination (DDD) process was recently described where evaporation of mineralized water is driven by diffusion within a packed bed. The energy source to drive the process is derived from low pressure condensing steam within the main condenser of a steam power generating plant. Since waste heat is used to drive the process, the main cost of fresh water production is attributed to the energy cost of pumping air and water through the packed bed. This report describes the annual progress made in the development and analysis of a Diffusion Driven Desalination (DDD) system. A combined thermodynamic and dynamic analysis demonstrates that the DDD process can yield a fresh water production of 1.03 million gallon/day by utilizing waste heat from a 100 MW steam power plant based on a condensing steam pressure of only 3'' Hg. Throughout the past year, the main focus of the desalination process has been on the diffusion tower and direct contact condenser. Detailed heat and mass transfer analyses required to size and analyze these heat and mass transfer devices are described. An experimental DDD facility has been fabricated, and temperature and humidity data have been collected over a range of flow and thermal conditions. The analyses agree quite well with the current data and the information available in the literature. Direct contact condensers with and without packing have been investigated. It has been experimentally observed that the fresh water production rate is significantly enhanced when packing is added to the direct contact condensers.

  15. Copper toxicity to the fresh water snail, Lymnaea luteola

    SciTech Connect

    Reddy, N.M.; Rao, P.V.

    1987-07-01

    Haemocyanins are found in arthropoda and mollusca and show a copper content characteristic for each phylum. Heavy metal accumulation by mollusks is widely reported. Approximately one third of the enzymes either required addition of a metal ion as a cofactor in order to exhibit maximum activity or contained a slightly bound metal ion which appeared to be involved in the catalytic process. Copper is the only metal which has been detected in significant amounts in amino oxidase. The present study is designed to evaluate the influence of such copper, which is of such common occurrence in biological material, on some of the lipolytic enzymes of fresh water pulmonate snail, Lymnaea luteola when added to ambient medium. The present study also highlights the possible detoxification mechanism prevailing in this fresh water mollusk.

  16. Modeling the Influence of Variable Tributary Inflow on Circulation and Contaminant Transport in a Water Supply Reservoir

    NASA Astrophysics Data System (ADS)

    Nguyen, L. H.; Wildman, R.

    2012-12-01

    This study characterizes quantitatively the flow and mixing regimes of a water supply reservoir, while also conducting numerical tracer experiments on different operation scenarios. We investigate the effects of weather events on water quality via storm water inflows. Our study site the Kensico Reservoir, New York, the penultimate reservoir of New York City's water supply, is never filtered and thus dependent on stringent watershed protection. This reservoir must meet federal drinking water standards under changing conditions such as increased suburban, commercial, and highway developments that are much higher than the rest of the watershed. Impacts from these sources on water quality are magnified by minor tributary flows subject to contaminants from development projects as other tributaries providing >99% of water to this reservoir are exceedingly clean due to management practices upstream. These threats, coupled with possible changes in the frequency/intensity of weather events due to climate change, increase the potential for contaminants to enter the reservoir and drinking water intakes. This situation provides us with the unique ability to study the effects of weather events on water quality via insignificant storm water inflows, without influence from the major tributaries due to their pristine water quality characteristics. The concentration of contaminants at the drinking water intake depends partially on transport from their point of entry in the reservoir. Thus, it is crucial to understand water circulation in this reservoir and to estimate residence times and water ages at different locations and under different hydrologic scenarios. We described water age, residence time, thermal structure, and flow dynamics of tributary plumes in Kensico Reservoir during a 22-year simulation period using a two-dimensional hydrodynamic and water quality model (CE-QUAL-W2). Our estimates of water age can reach a maximum of ~300 days in deep-reservoir-cells, with

  17. Collective oscillations of fresh and salt water bubble plumes

    PubMed

    Orris; Nicholas

    2000-02-01

    Bubble plumes of various void fractions and sizes were produced by varying the flow velocity of a water jet impinging normally on a water surface. The bubbles entrained at the surface were carried downwards by the fluid flow to depths ranging from 33 to 65 cm, and formed roughly cylindrical plumes with diameters ranging from 12 to 27 cm. The acoustic emissions from the plumes were recorded onto digital audio tape using a hydrophone placed outside the cloud at distances ranging from 50 cm to 16.0 m. Closeup video images of the individual bubbles within the plume were also taken in order to gain knowledge of the bubble size distributions. The experiments were performed in both fresh-water and salt-water environments. The fresh-water clouds emitted sounds with a modal structure that was significantly different from that produced by the salt-water clouds. Furthermore, the smaller bubbles present in the salt-water clouds have a fundamental effect on the amplification of turbulence noise, generating sound at significant levels for frequencies up to several hundred Hertz.

  18. Identification of Corrosion Products Due to Seawater and Fresh Water

    NASA Astrophysics Data System (ADS)

    Gismelseed, A.; Elzain, M.; Yousif, A.; Al Rawas, A.; Al-Omari, I. A.; Widatallah, H.; Rais, A.

    2004-12-01

    Mössbauer and X-ray diffraction (XRD) measurements were performed on corrosion products extracted from the inner surface of two different metal tubes used in a desalination plant in Oman. One of the tubes corroded due to the seawater while the second was corroded due to fresh water. The corrosion products thus resulted due to seawater were scrapped off in to two layers, the easily removable rust from the top is termed outer surface corrosion product and the strongly adhered rust as internal corrosion product. The Mössbauer spectra together with the XRD pattern of the outer surface showed the presence of magnetite (Fe3O4), akaganeite (β-FeOOH), lepidocrocite (γ-FeOOH), goethite (α-FeOOH) and hematite (Fe2O3). The inner surface however showed the presence of akaganite, goethite, and magnetite. On the other hand, the corrosion products due to the fresh water showed only the presence of goethite and magnetite. The mechanism of the corrosion process will be discussed based on the significant differences between the formation of the iron components of the corrosion products due to seawater and the fresh water.

  19. Innovative Fresh Water Production Process for Fossil Fuel Plants

    SciTech Connect

    James F. Klausner; Renwei Mei; Yi Li; Jessica Knight

    2006-09-29

    This project concerns a diffusion driven desalination (DDD) process where warm water is evaporated into a low humidity air stream, and the vapor is condensed out to produce distilled water. Although the process has a low fresh water to feed water conversion efficiency, it has been demonstrated that this process can potentially produce low cost distilled water when driven by low grade waste heat. This report summarizes the progress made in the development and analysis of a Diffusion Driven Desalination (DDD) system. Detailed heat and mass transfer analyses required to size and analyze the diffusion tower using a heated water input are described. The analyses agree quite well with the current data and the information available in the literature. The direct contact condenser has also been thoroughly analyzed and the system performance at optimal operating conditions has been considered using a heated water/ambient air input to the diffusion tower. The diffusion tower has also been analyzed using a heated air input. The DDD laboratory facility has successfully been modified to include an air heating section. Experiments have been conducted over a range of parameters for two different cases: heated air/heated water and heated air/ambient water. A theoretical heat and mass transfer model has been examined for both of these cases and agreement between the experimental and theoretical data is good. A parametric study reveals that for every liquid mass flux there is an air mass flux value where the diffusion tower energy consumption is minimal and an air mass flux where the fresh water production flux is maximized. A study was also performed to compare the DDD process with different inlet operating conditions as well as different packing. It is shown that the heated air/heated water case is more capable of greater fresh water production with the same energy consumption than the ambient air/heated water process at high liquid mass flux. It is also shown that there can be

  20. Increasing nitrogen limitation in the Bothnian Sea, potentially caused by inflow of phosphate-rich water from the Baltic Proper.

    PubMed

    Rolff, Carl; Elfwing, Tina

    2015-11-01

    The study showed that the open water of the Bothnian Sea (BS) is likely to have shifted from altering nitrogen and phosphorous limitations of the spring bloom to more nitrogen-limited conditions during the last 20 years. This is affected by the by inflow of phosphate-rich and oxygen-depleted water from depths near the halocline in the northern Baltic Proper, where severe oxygen conditions currently cause extreme phosphate concentrations in the deep water. The change in relation between inorganic nitrogen and phosphorous in the BS occurs first in the deep water and then progresses to the surface water. The change can potentially cause increased production in the BS and more frequent cyanobacterial blooms. There does not appear to be any immediate concern in the short-term perspective for the state of the BS, but a progression of the processes may lead to a more eutrophic state of the BS.

  1. Increasing nitrogen limitation in the Bothnian Sea, potentially caused by inflow of phosphate-rich water from the Baltic Proper.

    PubMed

    Rolff, Carl; Elfwing, Tina

    2015-11-01

    The study showed that the open water of the Bothnian Sea (BS) is likely to have shifted from altering nitrogen and phosphorous limitations of the spring bloom to more nitrogen-limited conditions during the last 20 years. This is affected by the by inflow of phosphate-rich and oxygen-depleted water from depths near the halocline in the northern Baltic Proper, where severe oxygen conditions currently cause extreme phosphate concentrations in the deep water. The change in relation between inorganic nitrogen and phosphorous in the BS occurs first in the deep water and then progresses to the surface water. The change can potentially cause increased production in the BS and more frequent cyanobacterial blooms. There does not appear to be any immediate concern in the short-term perspective for the state of the BS, but a progression of the processes may lead to a more eutrophic state of the BS. PMID:25990584

  2. A simple method for locating the fresh water-salt water interface using pressure data.

    PubMed

    Kim, Kue-Young; Chon, Chul-Min; Park, Ki-Hwa

    2007-01-01

    Salt water intrusion is a key issue in dealing with exploitation, restoration, and management of fresh ground water in coastal aquifers. Constant monitoring of the fresh water-salt water interface is necessary for proper management of ground water resources. This study presents a simple method to estimate the depth of the fresh water-salt water interface in coastal aquifers using two sets of pressure data obtained from the fresh and saline zones within a single borehole. This method uses the density difference between fresh water and saline water and can practically be used at coastal aquifers that have a relatively sharp fresh water-salt water interface with a thin transition zone. The proposed method was applied to data collected from a coastal aquifer on Jeju Island, Korea, to estimate the variations in the depth of the interface. The interface varied with daily tidal fluctuations and heavy rainfall in the rainy season. The estimated depth of the interface showed a good agreement with the measured electrical conductivity profile.

  3. Caldecott 4th bore tunnel project: influence of ground water flows and inflows triggered by tectonic fault zones?

    NASA Astrophysics Data System (ADS)

    Neuhuber, G.; G. Neuhuber1, W. Klary1, A. Nitschke1, B. Thapa2, Chris Risden3, T. Crampton4, D. Zerga5

    2011-12-01

    nearly perpendicular, separating different geological units were expected along the 4th Bore alignment. This paper will describe encountered ground conditions adjacent to the fault contact where rock conditions are influenced to an extent of 5ft to 85ft from the contact. This paper will also compare the anticipated inflow of 55gpm within 100ft of the top heading excavation and fault zones inflow rates up to 110gpm to the actual measured maximum inflow into the tunnel of150gpm away from fault zones to a maximum inflow between 60gpm and 100gpm near fault zones. In presence of fault zones the water inflow is significant lower than expected and in absence of fault zones higher inflow rates as expected were measured. This paper will discuss the influence of fault zones on the water inflow - or are rock properties and lithology more significant?

  4. Increased salinization of fresh water in the Northeastern United States

    USGS Publications Warehouse

    Kaushal, S.S.; Groffman, P.M.; Likens, G.E.; Belt, K.T.; Stack, W.P.; Kelly, V.R.; Band, L.E.; Fisher, G.T.

    2005-01-01

    Chloride concentrations are increasing at a rate that threatens the availability of fresh water in the northeastern United States. Increases in roadways and deicer use are now salinizing fresh waters, degrading habitat for aquatic organisms, and impacting large supplies of drinking water for humans throughout the region. We observed chloride concentrations of up to 25% of the concentration of seawater in streams of Maryland, New York, and New Hampshire during winters, and chloride concentrations remaining up to 100 times greater than unimpacted forest streams during summers. Mean annual chloride concentration increased as a function of impervious surface and exceeded tolerance for freshwater life in suburban and urban watersheds. Our analysis shows that if salinity were to continue to increase at its present rate due to changes in impervious surface coverage and current management practices, many surface waters in the northeastern United States would not be potable for human consumption and would become toxic to freshwater life within the next century. ?? 2005 by The National Academy of Sciences of the USA.

  5. Striped bass: environmental risks in fresh and salt water

    SciTech Connect

    Coutant, C.C.

    1985-01-01

    At the 112th Annual meeting of the American Fisheries Society (AFS) at Hilton Head Island, South Carolina, the society held a 1-day symposium Striped Bass: Environmental Risks in Fresh and Salt Water. This issue of the Transactions contains some of the papers from that symposium. This symposium explored several hypotheses about sources of environmental risks that could cause problems for striped bass populations: (1) habitat squeeze on adults stemming from their thermal and dissolved oxygen requirements; (2) stress from toxic materials; and (3) meteorological controls of living space and food. A nonenvironmental factor, fishing pressure, also was raised as an alternative hypothesis.

  6. The bioconcentration of {sup 131}I in fresh water fish

    SciTech Connect

    Yu, K.N.; Cheung, T.; Young, E.C.M.; Luo, D.L.

    1996-11-01

    The dynamic characteristics of the radionuclide concentration process in fresh water fish have been studied. The experimental data for the tilapias were fitted using a simple compartment model to get characteristics parameters such as concentration factors, elimination rate constants, and initial concentration rates, which are 3.08 Bq kg{sup {minus}1}/Bq L{sup {minus}1}, 0.00573 h{sup {minus}1}, and 12.42 Bq kg{sup {minus}1} h{sup {minus}1}, respectively. The relative concentrations of {sup 131}I in different parts, i.e., head, gills, flesh, bone and internal organs, of the tilapias are also determined, which are found to be 10.8, 15.4, 26.1, 11.0, and 37.0%, respectively. The effects of different factors on the transfer of radionuclides in fresh water fishes are also discussed. Experiments on the tilapias and the common carp show that the variation of concentration factors for different species may be significant even for the same radionuclide and the same ecological system. On the other hand, the variation in the concentration factors for the flesh of the tilapias is not significant for a certain range of {sup 131}I concentrations in the water. 12 refs., 1 fig., 1 tab.

  7. Atomic fluorescence determination of mercury in fresh water ecosystems.

    PubMed

    Knox, R; Kammin, W R; Thomson, D

    1995-01-01

    This paper reports on an investigation into determining nanogram/l quantities of mercury in marine and fresh water matrices using a cold vapour generation of mercury, followed by fluorescence detection. Samples were prepared for analysis using a free bromine oxidation technique. A high efficiency gas-liquid separator was used to enhance the detection of mercury. For fresh water, typical method detection limits (MDL) were determined at less than 1 nanogram/l (ng/l). For near shore seawater, the MDL was 1.2 ng/l. Method spikes, which were performed at 20 ng/l, showed mean recoveries within US EPA Contract Laboratory Protocol (CLP) acceptance criteria. System blanks averaged 0.12 ng/l, and recoveries of NIST 1641c diluted to 29.4 ng/l averaged 93.4%. A number of local rivers and streams were sampled, and mercury was determined. All results to date indicate mercury levels below the US EPA chronic water quality criteria for mercury. PMID:18925015

  8. Fresh Water Generation from Aquifer-Pressured Carbon Storage

    SciTech Connect

    Aines, R D; Wolery, T J; Bourcier, W L; Wolfe, T; Haussmann, C

    2010-02-19

    Can we use the pressure associated with sequestration to make brine into fresh water? This project is establishing the potential for using brine pressurized by Carbon Capture and Storage (CCS) operations in saline formations as the feedstock for desalination and water treatment technologies including reverse osmosis (RO) and nanofiltration (NF). Possible products are: Drinking water, Cooling water, and Extra aquifer space for CO{sub 2} storage. The conclusions are: (1) Many saline formation waters appear to be amenable to largely conventional RO treatment; (2) Thermodynamic modeling indicates that osmotic pressure is more limiting on water recovery than mineral scaling; (3) The use of thermodynamic modeling with Pitzer's equations (or Extended UNIQUAC) allows accurate estimation of osmotic pressure limits; (4) A general categorization of treatment feasibility is based on TDS has been proposed, in which brines with 10,000-85,000 mg/L are the most attractive targets; (5) Brines in this TDS range appear to be abundant (geographically and with depth) and could be targeted in planning future CCS operations (including site selection and choice of injection formation); and (6) The estimated cost of treating waters in the 10,000-85,000 mg/L TDS range is about half that for conventional seawater desalination, due to the anticipated pressure recovery.

  9. Status of fresh water mussel research in Virginia

    SciTech Connect

    Neves, R.J.

    1983-10-01

    In addition to the previously described mussel research projects in Virginia, the Tennessee Valley Authority (TVA) has undertaken a wide-ranging Cumberlandian Mollusc Conservation Program to (a) accumulate information on the present distribution, life histories, and ecological requirements of the Cumberlandian mussel fauna and (b) conserve or increase populations of these species in the Tennessee River drainage. This TVA program has contributed greatly toward a better understanding of species status, water quality problems, and research needs for this unique faunal group. The attention currently being given to fresh water mussels in the upper Tennessee River system is unprecedented, and participating State and Federal agencies are to be commended for supporting conservation activities far beyond what is legally required. The success of a mollusk conservation effort will depend on public awareness, not of mussels in and for themselves but as indicators of riverine degradation and its effect on environmental health and recreational opportunities for man.

  10. Occurrence of human enteric viruses at freshwater beaches during swimming season and its link to water inflow.

    PubMed

    Lee, Chang Soo; Lee, Cheonghoon; Marion, Jason; Wang, Qiuhong; Saif, Linda; Lee, Jiyoung

    2014-02-15

    Human enteric viruses are significant etiological agents for many recreational waterborne illnesses. The occurrence and density of human enteric viruses such as human adenovirus (HAdV), human enterovirus (HEnV), and human norovirus genogroups I/II (HNoV GI/GII) were investigated using quantitative real-time PCR (qPCR) at freshwater beaches along with monitoring fecal indicators and environmental parameters. During the 2009 swimming season, water samples were collected from three inland freshwater beaches in Ohio, USA. Of the total samples, 40% (26/65) and 17% (11/65) were positive for HAdV and HEnV respectively, but HNoV GI/GII were not detected. There was no significant association among the detected human enteric viruses (HAdV and HEnV) and fecal bacteria indicators (Escherichia coli and Bacteroides) by Spearman correlation and principal component analyses. Logistic regression analysis also revealed that the odds of finding HAdV or HEnV was not influenced by levels of fecal bacteria indicators. However, there was a 14-fold increase in the odds of HEnV detection for each 1-log increase in daily water inflow (m(3)/s) into freshwater beach reservoirs (adjusted odds ratio=14.2; 95% confidence interval=1.19-171). In summary, the viral occurrence at the freshwater beaches was not readily explained by the levels of fecal bacteria indicators, but appeared to be more related to water reservoir inflows. These results suggest that hydrological data must be considered in future epidemiology efforts aimed at characterizing beach water safety.

  11. Increasing water stress negatively affects pear fruit growth by reducing first its xylem and then its phloem inflow.

    PubMed

    Morandi, Brunella; Losciale, Pasquale; Manfrini, Luigi; Zibordi, Marco; Anconelli, Stefano; Galli, Fabio; Pierpaoli, Emanuele; Corelli Grappadelli, Luca

    2014-10-15

    Drought stress negatively affects many physiological parameters and determines lower yields and fruit size. This paper investigates on the effects of prolonged water restriction on leaf gas exchanges, water relations and fruit growth on a 24-h time-scale in order to understand how different physiological processes interact to each other to face increasing drought stress and affect pear productive performances during the season. The diurnal patterns of tree water relations, leaf gas exchanges, fruit growth, fruit vascular and transpiration flows were monitored at about 50, 95 and 145 days after full bloom (DAFB) on pear trees of the cv. Abbé Fétel, subjected to two irrigation regimes, corresponding to a water restitution of 100% and 25% of the estimated Etc, respectively. Drought stress progressively increased during the season due to lower soil tensions and higher daily vapour pressure deficits (VPDs). Stem water potential was the first parameter to be negatively affected by stress and determined the simultaneous reduction of fruit xylem flow, which at 95 DAFB was reflected by a decrease in fruit daily growth. Leaf photosynthesis was reduced only from 95 DAFB on, but was not immediately reflected by a decrease in fruit phloem flow, which instead was reduced only at 145 DAFB. This work shows how water stress negatively affects pear fruit growth by reducing first its xylem and then its phloem inflow. This determines a progressive increase in the phloem relative contribution to growth, which lead to the typical higher dry matter percentages of stressed fruit.

  12. Water-Quality Data Collected from Vallecito Reservoir, Its Inflows and Outflow, Southwestern Colorado, 1999-2002

    USGS Publications Warehouse

    Ranalli, Anthony J.

    2008-01-01

    The Pine River Watershed Stakeholders Group was created in December 1997 to allow local participation in addressing water-quality issues in Los Pi?os River watershed, including Vallecito Reservoir in southwestern Colorado. One water-quality issue identified by the stakeholder group is to increase the understanding of the current water quality of Vallecito Reservoir, its two major inflows, and its outflow. The U.S. Geological Survey (USGS), in cooperation with volunteers from the Pine River Watershed Stakeholders Group and the U.S. Environmental Protection Agency (USEPA), U.S. Bureau of Reclamation (BOR), Colorado Department of Public Health and Environment (CDPHE), Pine River Irrigation District, Southern Ute Tribe, San Juan Basin Health Department, and San Juan Resource Conservation and Development, collected water-quality samples from Vallecito Reservoir, its two major inflows, and its outflow between August 1999 and November 2002 at about monthly intervals from April through November. The water-quality samples were analyzed for total and dissolved metals (aluminum, arsenic, cadmium, copper, chromium, iron, lead, manganese, mercury, nickel, silver, and zinc), dissolved major ions (calcium, magnesium, sodium, potassium, chloride, bicarbonate, and sulfate), dissolved silica, dissolved organic carbon (DOC), ultraviolet (UV) absorbance at 254 and 280 nanometers, nutrients (total organic nitrogen, dissolved organic nitrogen, dissolved ammonia, dissolved nitrate, total phosphorus, dissolved phosphorus, and orthophosphate), chlorophyll-a (reservoir only), and suspended sediment (inlets to the reservoir only). Measurements of field properties (pH, specific conductance, water temperature, and dissolved oxygen) were also made at each sampling site each time a water-quality sample was collected. This report documents (1) sampling sites and times of sample collection, (2) sample-collection methods, (3) laboratory analytical methods, and (4) responsibilities of each agency

  13. Water dynamics in fresh and frozen yeasted dough.

    PubMed

    Loveday, Simon M; Huang, Victor T; Reid, David S; Winger, Ray J

    2012-01-01

    Water is an integral part of wheat flour dough-the amount, physical state, and location of water are crucial to the formation of a dough that will hold gas and produce an open, aerated crumb structure in the final product. This has been understood for centuries by craft bakers, who were highly attuned to the "feel" of dough in their hands. In the 20th century, empirical instruments were invented that simulated part of the breadmaking process, and their limited predictive capacity made them valuable quality control tools. During the latter decades of the 20th century the cost and availability of advanced instrumental methods for characterizing foods improved dramatically, and facilitated a "fundamental science" approach to food research. The physicochemical mechanisms by which water exerts such a strong influence on the character of dough are now better understood. This review contrasts the empirical and fundamental view points, and summarizes recent knowledge about the roles of water in the manufacture of fresh and frozen yeasted dough. PMID:22369259

  14. Water age, exposure time, and local flushing time in semi-enclosed, tidal basins with negligible freshwater inflow

    NASA Astrophysics Data System (ADS)

    Viero, Daniele Pietro; Defina, Andrea

    2016-04-01

    Within the framework of tidally flushed, semi-enclosed basins with negligible freshwater inflow, and under steady periodic flow conditions, three frequently used local transport time scales to quantify the efficiency of water renewal, namely water age, exposure time, and local flushing time are studied and compared to each other. In these environments, water renewal is strongly controlled by diffusion, and it is significantly affected by the return flow (i.e., the fraction of effluent water that returns into the basin on each flood tide). The definition of water age is here modified to account for the return flow, in analogy with exposure time and local flushing time. We consider approximate time scales, whose accuracy is analyzed, in order to overcome problems related to the size of the computational domain and to reduce the computational effort. A new approximate procedure is introduced to estimate water age, which is based on the water aging rate. Also, the concept of local flushing time as a relevant time scale is introduced. Under steady periodic conditions, we demonstrate that the local flushing time quantitatively corresponds to water age, and well approximates exposure time when the flow is dominated by diffusion. Since the effort required to compute water age and exposure time is greater than that required to compute the local flushing time, the present results can also have a practical interest in the assessment of water renewal efficiency of semi-enclosed water basins. The results of a modeling study, in which the lagoon of Venice is used as a benchmark, confirm the substantial quantitative equivalence between these three transport time scales in highly diffusive environments.

  15. Moisture Advection and Fresh Water Flux over Oceans

    NASA Technical Reports Server (NTRS)

    Tang, Wenqing; Liu, W. Timothy

    2002-01-01

    Moisture transport in the atmosphere is one of the most significant components in the hydrological cycle. Under stationary condition, ocean surface fresh water flux, which is the difference between precipitation (P) and evaporation (E), is balanced by the divergence of column-integrated moisture transport (IMT) in the atmosphere. Characterizing accurately a global picture of IMT from observation is a difficult task. It requires measurements of vertical profiles for wind vector and humidity. More specifically, IMT can be defined as the integration in pressure coordinates the product of specific humidity q and wind vector u, where g is the gravitational acceleration, and p, is the atmospheric pressure at ocean surface.In this study, a statistical relationship is derived between u, and u(sub)s using data from numerical weather prediction model. The relationship is then validated using surface and vertical profile from radiosonde data, before applied to spacebased measurements.

  16. Application of tidal energy for purification in fresh water lake

    NASA Astrophysics Data System (ADS)

    Jung, Rho-Taek; Isshiki, Hiroshi

    2015-01-01

    In order to preserve the quality of fresh water in the artificial lake after the reclamation of an intertidal flat at the mouth of a river, we suggest two novel methods of water purification by using tidal potential energy and an enclosed permeable embankment called an utsuro (Akai et al., 1990) in the reclaimed region. One method uses an inflatable bag on the seabed within an utsuro, while the other uses a moored floating barge out of a dyke. Each case employs a subsea pipe to allow flow between the inside and outside of the utsuro. The change in water level in the utsuro, which is pushed through the pipe by the potential energy outside, caused circulation in the artificial lake. In this paper, we analyzed the inflatable bag and floating barge motion as well as the pipe flow characteristics and drafts as given by a harmonic sea level, and compared the theoretical value with an experimental value with a simple small model basin. The numerical calculation based on theory showed good agreement with experimental values.

  17. Effects of acute fresh water exposure on water flux rates and osmotic responses in Kemp's ridley sea turtles (Lepidochelys kempi)

    NASA Technical Reports Server (NTRS)

    Ortiz, R. M.; Patterson, R. M.; Wade, C. E.; Byers, F. M.

    2000-01-01

    Water flux rates and osmotic responses of Kemp's Ridley sea turtles (Lepidochelys kempi) acutely exposed to fresh water were quantified. Salt-water adapted turtles were exposed to fresh water for 4 d before being returned to salt water. During the initial salt water phase, absolute and relative water flux rates were 1.2+/-0.1 l d(-1) and 123.0+/-6.8 ml kg(-1) d(-1), respectively. When turtles were exposed to fresh water, rates increased by approximately 30%. Upon return to salt water, rates decreased to original levels. Plasma osmolality, Na(+), K(+), and Cl(-) decreased during exposure to fresh water, and subsequently increased during the return to salt water. The Na(+):K(+) ratio was elevated during the fresh water phase and subsequently decreased upon return to salt water. Aldosterone and corticosterone were not altered during exposure to fresh water. Elevated water flux rates during fresh water exposure reflected an increase in water consumption, resulting in a decrease in ionic and osmotic concentrations. The lack of a change in adrenocorticoids to acute fresh water exposure suggests that adrenal responsiveness to an hypo-osmotic environment may be delayed in marine turtles when compared to marine mammals.

  18. Effects of acute fresh water exposure on water flux rates and osmotic responses in Kemp's ridley sea turtles (Lepidochelys kempi).

    PubMed

    Ortiz, R M; Patterson, R M; Wade, C E; Byers, F M

    2000-09-01

    Water flux rates and osmotic responses of Kemp's Ridley sea turtles (Lepidochelys kempi) acutely exposed to fresh water were quantified. Salt-water adapted turtles were exposed to fresh water for 4 d before being returned to salt water. During the initial salt water phase, absolute and relative water flux rates were 1.2+/-0.1 l d(-1) and 123.0+/-6.8 ml kg(-1) d(-1), respectively. When turtles were exposed to fresh water, rates increased by approximately 30%. Upon return to salt water, rates decreased to original levels. Plasma osmolality, Na(+), K(+), and Cl(-) decreased during exposure to fresh water, and subsequently increased during the return to salt water. The Na(+):K(+) ratio was elevated during the fresh water phase and subsequently decreased upon return to salt water. Aldosterone and corticosterone were not altered during exposure to fresh water. Elevated water flux rates during fresh water exposure reflected an increase in water consumption, resulting in a decrease in ionic and osmotic concentrations. The lack of a change in adrenocorticoids to acute fresh water exposure suggests that adrenal responsiveness to an hypo-osmotic environment may be delayed in marine turtles when compared to marine mammals.

  19. Example calculations of possible ground-water inflow to mine pits at the West Decker, East Decker, and proposed North Decker mines, southeastern Montana

    USGS Publications Warehouse

    Davis, R.E.

    1984-01-01

    Proposed plans to raise the spillway of the Tongue River Dam, Montana, 14 feet would result in an increase in the reservoir stage, which will affect the amount of ground-water inflow from the reservoir to existing and proposed surface coal mine pits near Tongue River Reservoir. Example calculations are based on flow from the reservoir to the mine pits through areas approximately perpendicular to the long axis of the reservoir. The planned increase in the stage of the reservoir will result in an increase of inflow to the mine pits in most areas. The increases will be greatest where the mine pits are near the reservoir and separated from the reservoir solely by aquifer zones of relatively large hydraulic conductivity. However, the inflow determined from the calculations is subject to a large degree of error, owing to the simplified method of calculation and the assumptions used. (USGS)

  20. Inflow rate-driven changes in the composition and dynamics of chromophoric dissolved organic matter in a large drinking water lake.

    PubMed

    Zhou, Yongqiang; Zhang, Yunlin; Jeppesen, Erik; Murphy, Kathleen R; Shi, Kun; Liu, Mingliang; Liu, Xiaohan; Zhu, Guangwei

    2016-09-01

    Drinking water lakes are threatened globally and therefore in need of protection. To date, few studies have been carried out to investigate how the composition and dynamics of chromophoric dissolved organic matter (CDOM) in drinking water lakes are influenced by inflow rate. Such CDOM can lead to unpleasant taste and odor of the water and produce undesirable disinfection byproducts during drinking water treatment. We studied the drinking water Lake Qiandao, China, and found that the concentrations of suspended particulate matter (SPM) in the lake increased significantly with inflow rate (p < 0.001). Similarly, close relationships between inflow rate and the CDOM absorption coefficient at 350 nm a(350) and with terrestrial humic-like fluorescence C3 and a negative relationship between inflow rate and the first principal component (PC1) scores, which, in turn, were negatively related to the concentrations and relative molecular size of CDOM (p < 0.001), i.e. the concentration and molecular size of CDOM entering the lake increased proportionately with inflow rate. Furthermore, stable isotopes (δD and δ(18)O) were depleted in the upstream river mouth relative to downstream remaining lake regions, substantiating that riverine CDOM entering the lake was probably driven by inflow rate. This was further underpinned by remarkably higher mean chlorophyll-a and in situ measured terrestrial CDOM fluorescence (365/480 nm) and apparent oxygen utilization (AOU), and notably lower mean PC1 and CDOM spectral slope (S275-295) recorded in the upstream river mouth than in the downstream main lake area. Strong negative correlations between inflow rate and a(250):a(365), S275-295, and the spectral slope ratio (SR) implied that CDOM input to the lake in rainy period was dominated by larger organic molecules with a more humic-like character. Rainy period, especially rainstorm events, therefore poses a risk to drinking water safety and requires higher removal efficiency of CDOM

  1. Inflow rate-driven changes in the composition and dynamics of chromophoric dissolved organic matter in a large drinking water lake.

    PubMed

    Zhou, Yongqiang; Zhang, Yunlin; Jeppesen, Erik; Murphy, Kathleen R; Shi, Kun; Liu, Mingliang; Liu, Xiaohan; Zhu, Guangwei

    2016-09-01

    Drinking water lakes are threatened globally and therefore in need of protection. To date, few studies have been carried out to investigate how the composition and dynamics of chromophoric dissolved organic matter (CDOM) in drinking water lakes are influenced by inflow rate. Such CDOM can lead to unpleasant taste and odor of the water and produce undesirable disinfection byproducts during drinking water treatment. We studied the drinking water Lake Qiandao, China, and found that the concentrations of suspended particulate matter (SPM) in the lake increased significantly with inflow rate (p < 0.001). Similarly, close relationships between inflow rate and the CDOM absorption coefficient at 350 nm a(350) and with terrestrial humic-like fluorescence C3 and a negative relationship between inflow rate and the first principal component (PC1) scores, which, in turn, were negatively related to the concentrations and relative molecular size of CDOM (p < 0.001), i.e. the concentration and molecular size of CDOM entering the lake increased proportionately with inflow rate. Furthermore, stable isotopes (δD and δ(18)O) were depleted in the upstream river mouth relative to downstream remaining lake regions, substantiating that riverine CDOM entering the lake was probably driven by inflow rate. This was further underpinned by remarkably higher mean chlorophyll-a and in situ measured terrestrial CDOM fluorescence (365/480 nm) and apparent oxygen utilization (AOU), and notably lower mean PC1 and CDOM spectral slope (S275-295) recorded in the upstream river mouth than in the downstream main lake area. Strong negative correlations between inflow rate and a(250):a(365), S275-295, and the spectral slope ratio (SR) implied that CDOM input to the lake in rainy period was dominated by larger organic molecules with a more humic-like character. Rainy period, especially rainstorm events, therefore poses a risk to drinking water safety and requires higher removal efficiency of CDOM

  2. Fresh Waters and Fish Diversity: Distribution, Protection and Disturbance in Tropical Australia

    PubMed Central

    Januchowski-Hartley, Stephanie R.; Pearson, Richard G.; Puschendorf, Robert; Rayner, Thomas

    2011-01-01

    Background Given the globally poor protection of fresh waters for their intrinsic ecological values, assessments are needed to determine how well fresh waters and supported fish species are incidentally protected within existing terrestrial protected-area networks, and to identify their vulnerability to human-induced disturbances. To date, gaps in data have severely constrained any attempt to explore the representation of fresh waters in tropical regions. Methodology and Results We determined the distribution of fresh waters and fish diversity in the Wet Tropics of Queensland, Australia. We then used distribution data of fresh waters, fish species, human-induced disturbances, and the terrestrial protected-area network to assess the effectiveness of terrestrial protected areas for fresh waters and fish species. We also identified human-induced disturbances likely to influence the effectiveness of freshwater protection and evaluated the vulnerability of fresh waters to these disturbances within and outside protected areas. The representation of fresh waters and fish species in the protected areas of the Wet Tropics is poor: 83% of stream types defined by order, 75% of wetland types, and 89% of fish species have less than 20% of their total Wet Tropics length, area or distribution completely within IUCN category II protected areas. Numerous disturbances affect fresh waters both within and outside of protected areas despite the high level of protection afforded to terrestrial areas in the Wet Tropics (>60% of the region). High-order streams and associated wetlands are influenced by the greatest number of human-induced disturbances and are also the least protected. Thirty-two percent of stream length upstream of protected areas has at least one human-induced disturbance present. Conclusions/Significance We demonstrate the need for greater consideration of explicit protection and off-reserve management for fresh waters and supported biodiversity by showing that, even in

  3. Characteristic of pollution with groundwater inflow (90)Sr natural waters and terrestrial ecosystems near a radioactive waste storage.

    PubMed

    Lavrentyeva, G V

    2014-09-01

    The studies were conducted in the territory contaminated by (90)Sr with groundwater inflow as a result of leakage from the near-surface trench-type radioactive waste storage. The vertical soil (90)Sr distribution up to the depth of 2-3 m is analyzed. The area of radioactive contamination to be calculated with a value which exceeds the minimum significant activity 1 kBq/kg for the tested soil layers: the contaminated area for the 0-5 cm soil layer amounted to 1800 ± 85 m(2), for the 5-10 cm soil layer amounted to 300 ± 12 m(2), for the 10-15 cm soil layer amounted to 180 ± 10 m(2). It is found that (90)Sr accumulation proceeds in a natural sorption geochemical barrier of the marshy terrace near flood plain. The exposure doses for terrestrial mollusks Bradybaena fruticum are presented. The excess (90)Sr interference level was registered both in the ground and surface water during winter and summer low-water periods and autumn heavy rains.

  4. Characteristic of pollution with groundwater inflow (90)Sr natural waters and terrestrial ecosystems near a radioactive waste storage.

    PubMed

    Lavrentyeva, G V

    2014-09-01

    The studies were conducted in the territory contaminated by (90)Sr with groundwater inflow as a result of leakage from the near-surface trench-type radioactive waste storage. The vertical soil (90)Sr distribution up to the depth of 2-3 m is analyzed. The area of radioactive contamination to be calculated with a value which exceeds the minimum significant activity 1 kBq/kg for the tested soil layers: the contaminated area for the 0-5 cm soil layer amounted to 1800 ± 85 m(2), for the 5-10 cm soil layer amounted to 300 ± 12 m(2), for the 10-15 cm soil layer amounted to 180 ± 10 m(2). It is found that (90)Sr accumulation proceeds in a natural sorption geochemical barrier of the marshy terrace near flood plain. The exposure doses for terrestrial mollusks Bradybaena fruticum are presented. The excess (90)Sr interference level was registered both in the ground and surface water during winter and summer low-water periods and autumn heavy rains. PMID:24832768

  5. Wet Worlds: Explore the World of Water. Marine and Fresh Water Activities for the Elementary Classroom.

    ERIC Educational Resources Information Center

    Solomon, Gerard; And Others

    Complete with student worksheets, field trip ideas, illustrations, vocabulary lists, suggested materials, and step-by-step procedures, the document presents a compilation of ideas for teaching elementary school (K-6) students about marine and fresh water. In the first unit students build miniature monuments and observe the deterioration of…

  6. Correlation of lineaments to ground water inflows in a bedrock tunnel.

    PubMed

    Mabee, Stephen B; Curry, Patrick J; Hardcastle, Kenneth C

    2002-01-01

    Lineaments derived from three image types (1:80,000 black and white, 1:58,000 color infrared, and 1:250,000 side-looking airborne radar) were compared to water-bearing features within a 9.6 km section of tunnel being constructed through foliated crystalline metamorphic bedrock in a glaciated region of eastern Massachusetts. Lineaments drawn by three observers during two independent trials (N = 9137) were reduced to three sets (one per image type) of coincident lineaments (N = 794). Thirty-five coincident lineaments crossed the tunnel. Nineteen discrete flow zones, each producing > or = 19 L/min, were identified in the tunnel and used to quantify the reliability of lineament analysis as a method of predicting water-bearing features in glaciated metamorphic Thirteen (68%) of the flow zones correlate with coincident lineaments, six zones correlate with more than one image type, and one zone correlates with all three image types. Overall, without additional corroborating evidence, it is difficult to interpret in advance which lineaments will result in a successful correlation with water-producing zones in the subsurface and which ones will not. Most of the observed flow (80%) correlates with northwest-trending coincident lineaments; however, the majority of the flow (67%) associated with these lineaments is produced from structures that strike to the north or northeast. In addition, only 15 of the 35 coincident lineaments correlate with the flow zones, indicating that 20 lineaments are not associated with any appreciable flow. Six flow zones are undetected by the lineament analysis.

  7. Regression study of environmental quality objectives for soil, fresh water, and marine water, derived independently.

    PubMed

    Vega, M M; Urzelai, A; Angulo, E

    1997-12-01

    A regression study among environmental quality objectives on soil, marine and fresh water is studied, considering toxicity data on ecological representative species of invertebrates. The study was carried out by comparing VIE-C values, as defined by E. Angulo and A. Urzelai (1994, in Plan Director para la Protección del Suelo. Calidad del Suelo. Valores Indicativos de Evaluacion, pp. 121-184. IHOBE, Bilbao). To derive these VIE-C values, no-observed-effect concentrations from chronic single-species assays that consider relevant parameters in population dynamics are used. The calculations follow the method of N. M. van Straalen and C.A.J. Denneman (1989, Ecotoxicol. Environ. Saf. 18, 241-251). Equations relating long-term toxicity data of fresh/marine waters, soil/marine water, and soil/fresh water for five metals (Cd, Cu, Hg, Pb, and Zn) are calculated, indicating good correlation between environments: 0.85, 0.78, and 0.89, respectively. On the basis of these results this approach may be useful to obtain soil quality criteria values from other environmental compartments, when soil data are not available.

  8. Excavation of the Aica-Mules pilot tunnel for the Brenner base tunnel: information gained on water inflows in tunnels in granitic massifs

    NASA Astrophysics Data System (ADS)

    Perello, Paolo; Baietto, Alessandro; Burger, Ulrich; Skuk, Stefan

    2014-05-01

    The construction of the Aica-Mules tunnel, completed in 2010, provides a relevant case history for improving the knowledge of hydrogeological issues related to the excavation of deep tunnels in granitic massifs. The Aica-Mules tunnel is a 10 km-long structure, forming part of the high-speed railway connection between Austria and Italy across the Alpine chain, located at an average depth of 500-1,000 m below the surface. Prior to and during the construction, intense hydrogeological monitoring was set up, allowing the collection of abundant data concerning: (1) the evolution of water inflows into the tunnel; (2) the chemistry and temperature of drained groundwater; and (3) the influence of tunnel drainage on springs. Based on detailed analysis of geological/hydrogeological data, this article provides an insight into the permeability distribution in granitic rocks affected by relevant brittle tectonic deformation, and the consequences of water inflow during excavation. The available time series from the principal water discharges in the tunnel have been used in order to test the reliability of some of the most commonly applied analytical methods for the forecast of water inflows into tunnels.

  9. Investigation and incorporation of water inflow uncertainties through stochastic modelling in a combined optimisation methodology for water allocation in Alfeios River (Greece)

    NASA Astrophysics Data System (ADS)

    Bekri, Eleni; Yannopoulos, Panayotis; Disse, Markus

    2014-05-01

    The Alfeios River plays a vital role for Western Peloponnisos in Greece from natural, ecological, social and economic aspect. The main river and its six tributaries, forming the longest watercourse and the highest streamflow rate of Peloponnisose, represent a significant source of water supply for the region, aiming at delivering and satisfying the expected demands from a variety of water users, including irrigation, drinking water supply, hydropower production and recreation. In the previous EGU General Assembly, a fuzzy-boundary-interval linear programming methodology, based on Li et al. (2010) and Bekri et al. (2012), has been presented for optimal water allocation under uncertain and vague system conditions in the Alfeios River Basin. Uncertainties associated with the benefit and cost coefficient in the objective function of the main water uses (hydropower production and irrigation) were expressed as probability distributions and fuzzy boundary intervals derived by associated α-cut levels. The uncertainty of the monthly water inflows was not incorporated in the previous initial application and the analysis of all other sources of uncertainty has been applied to two extreme hydrologic years represented by a selected wet and dry year. To manage and operate the river system, decision makers should be able to analyze and evaluate the impact of various hydrologic scenarios. In the present work, the critical uncertain parameter of water inflows is analyzed and its incorporation as an additional type of uncertainty in the suggested methodology is investigated, in order to enable the assessment of optimal water allocation for hydrologic and socio-economic scenarios based both on historical data and projected climate change conditions. For this purpose, stochastic simulation analysis for a part of the Alfeios river system is undertaken, testing various stochastic models from simple stationary ones (AR and ARMA), Thomas-Fiering, ARIMA as well as more sophisticated and

  10. Mortality of experimentally descaled smolts of coho salmon (Oncorhynchus kisutch) in fresh and salt water

    USGS Publications Warehouse

    Bouck, Gerald R.; Smith, Stanley D.

    1979-01-01

    Removal of slime from 25% of the body caused no deaths among smolts of coho salmon in fresh water or in seawater (28‰). Removal of slime and scales from the same percentage of body area caused no deaths in fresh water, but 75% mortality within 10 days in seawater. The 10-day median tolerance limit was 10% scale removal immediately before the smolts entered seawater. Mortality was highest when the scales were removed from the area of the rib cage. Recovery of smolts in fresh water from a loss of scales that would be lethal in seawater occurred rapidly; 90% of the fish regained tolerance to seawater within 1 day.

  11. Modeling fresh water lens damage and recovery on atolls after storm-wave washover.

    PubMed

    Chui, Ting Fong May; Terry, James P

    2012-01-01

    The principal natural source of fresh water on scattered coral atolls throughout the tropical Pacific Ocean is thin unconfined groundwater lenses within islet substrates. Although there are many threats to the viability of atoll fresh water lenses, salinization caused by large storm waves washing over individual atoll islets is poorly understood. In this study, a mathematical modeling approach is used to examine the immediate responses, longer-term behavior, and subsequent (partial) recovery of a Pacific atoll fresh water lens after saline damage caused by cyclone-generated wave washover under different scenarios. Important findings include: (1) the saline plume formed by a washover event mostly migrates downward first through the top coral sand and gravel substrate, but then exits the aquifer to the ocean laterally through the more permeable basement limestone; (2) a lower water table position before the washover event, rather than a longer duration of storm washover, causes more severe damage to the fresh water lens; (3) relatively fresher water can possibly be found as a preserved horizon in the deeper part of an aquifer after disturbance, especially if the fresh water lens extends into the limestone under normal conditions; (4) post-cyclone accumulation of sea water in the central depression (swamp) of an atoll islet prolongs the later stage of fresh water lens recovery. PMID:21883195

  12. Modeling fresh water lens damage and recovery on atolls after storm-wave washover.

    PubMed

    Chui, Ting Fong May; Terry, James P

    2012-01-01

    The principal natural source of fresh water on scattered coral atolls throughout the tropical Pacific Ocean is thin unconfined groundwater lenses within islet substrates. Although there are many threats to the viability of atoll fresh water lenses, salinization caused by large storm waves washing over individual atoll islets is poorly understood. In this study, a mathematical modeling approach is used to examine the immediate responses, longer-term behavior, and subsequent (partial) recovery of a Pacific atoll fresh water lens after saline damage caused by cyclone-generated wave washover under different scenarios. Important findings include: (1) the saline plume formed by a washover event mostly migrates downward first through the top coral sand and gravel substrate, but then exits the aquifer to the ocean laterally through the more permeable basement limestone; (2) a lower water table position before the washover event, rather than a longer duration of storm washover, causes more severe damage to the fresh water lens; (3) relatively fresher water can possibly be found as a preserved horizon in the deeper part of an aquifer after disturbance, especially if the fresh water lens extends into the limestone under normal conditions; (4) post-cyclone accumulation of sea water in the central depression (swamp) of an atoll islet prolongs the later stage of fresh water lens recovery.

  13. Electromyogram as a measure of heavy metal toxicity in fresh water and salt water mussels

    SciTech Connect

    Kidder, G.W. III |; McCoy, A.A. |

    1996-02-01

    The response of bivalves to heavy metals and other toxins has usually been determined by observing valve position. Since mussels close their valves to avoid noxious stimuli, experimental delivery of chemicals ins uncertain. To obtain constant results plastic spacers can be employed to hold the valves apart. This obviates valve position as an index of response and some other method is required. Electromyography of intact mussels is one such index, giving a simple, effective, and quantitative measurement of activity. Experiments are reported in this article on the effects of added mercury on salt water and fresh water species.

  14. Clear salt water above sediment-laden fresh water: Interfacial instabilities

    NASA Astrophysics Data System (ADS)

    Schulte, B.; Konopliv, N.; Meiburg, E.

    2016-05-01

    The stability of an interface separating less dense, clear salt water above from more dense, sediment-laden fresh water below is explored via direct numerical simulations. We find that the destabilizing effects of double diffusion and particle settling amplify each other above the diffusive interface, whereas they tend to cancel each other below. For moderate settling velocities, plumes form both above and below the interface, whereas for large settling velocities plume formation below the interface is suppressed. We identify the dimensionless parameter that determines in which regime a given flow takes place, along with the critical value at which the transition between the regimes takes place.

  15. Population and annual renewable fresh water availability: selected countries, 1955-2050.

    PubMed

    1995-03-01

    This chart presents population figures and total annual renewable fresh water available by country for 100 countries as well as estimates of per capita water availability based on these figures for 1955, for 1990, and for the UN medium population projection for 2025 and 2050. Graphs are provided which illustrate the population experiencing fresh water scarcity for 1990-2050 according to the UN's low, medium, and high population projections. The low projection (7.9 billion) shows 3.5 billion people living in 51 water-short countries, the medium projection (nearly 10 billion) has 4.4 billion people living in 58 water-short countries, and the high projection (11.9 billion) places 7.7 billion people in 66 water-short nations. Thus, there is an urgent need for population stabilization policies as well as efforts to ensure that all people have access to clean fresh water.

  16. Effects of Basin Flux on Regional Interactions between Fresh Water and Saline Groundwater

    NASA Astrophysics Data System (ADS)

    Xie, S.; Murdoch, L. C.; Falta, R. W.

    2013-12-01

    Saline groundwater underlies fresh water aquifers at depths of 100 m or less in the midwestern U.S. to one to several kilometers in coastal areas. The upward migration of the interface between fresh and saline water can degrade freshwater aquifers and threaten aquatic ecosystems if the saline water discharges to surface water. Storage of CO2 in deep saline aquifers is being considered to reduce greenhouse gases in the atmosphere, and this process is expected to increase the pressure in these deep aquifers. One potential consequence of pressurization is an increase in the upward flux of saline water. This research aims to evaluate the risks associated with increasing the flux from saline to fresh water aquifers as a result of CO2 storage. The research approach is to develop and evaluate simulations of fresh water aquifers overlying saline groundwater that is subjected to changes in flux. Computational codes COMSOL, SEAWAT, and TOUGH2 were verified by solving classic benchmark problems of density-dependent flow. The models were then used to analyze idealized 2D and 3D geometries representing the essential details of a shallow, fresh water aquifer underlain by a saline ground water in a sedimentary basin. The effects of saline encroachment are evaluated using a sensitivity analysis of key parameters, and the results are formulated in both dimensioned and dimensionless form. Results indicate that the depth of the saline water-freshwater interface is closely related to the surface water circulation pattern as well as the magnitude and duration of basin encroachment. Increased upward flux of saline water will raise the interface between salt and fresh water, and it will increase the salinity of water discharging to streams. However, the expected magnitudes of these effects appear to be small when the expected changes in flux caused by CO2 storage are considered. Ongoing work is refining these analyses and verify them using field observations to further constrain risks

  17. Real-time Control of sewer pumps by using ControlNEXT to smooth inflow at Waste Water Treatment Plant Garmerwolde

    NASA Astrophysics Data System (ADS)

    van Heeringen, Klaas-Jan; van Nooijen, Ronald; Kooij, Kees; Postma, Bokke

    2016-04-01

    The Garmerwolde waste water treatment plant (WWTP) in the Groningen area of the Netherlands, receives waste water from a large area. That waste water is collected from many sewer systems and transported to the WWTP through pressurized pipes. The supply of waste water to the WWTP is relatively low and very irregular during dry-weather conditions, resulting in a random pattern of flows. This irregularity is the effect of the local control of the pumps, where the pumps are individually operated as an on/off control based on the water levels in the connected sewer system. The influent may change from zero to high values in a few minutes. The treatment processes at the WWTP are negatively influenced by this irregularity, which ends in high costs for energy and use of chemicals. The ControlNEXT central control system is used to control the 5 largest pump stations, such that the total inflow at the WWTP becomes much smoother. This results in a reduction of operational costs of about 10%. The control algorithm determines whether the actual condition is dry or wet, based on real-time radar precipitation images and the rainfall forecast product HiRLAM. All actual data is also collected and validated, like water levels, pump operations and pump availability. This data management is done using Delft-FEWS. If the situation is identified as "wet", the sewer systems are emptied as far as possible to create maximum storage. If the situation is "dry" (and of course there is a dead band between dry and wet), the pumps are operated such that the total inflow into the WWTP is smoothed. This is done with a Greedy algorithm, developed by Delft University of Technology. The algorithm makes a plan for the next 24 hours (as the daily inflow has a typical daily pattern) and generally stores some water volume in the sewer systems during the day to be able to continue operations during the night. The pumps are controlled with a time step of 5 minutes, where ControlNEXT manages the

  18. Estimation of water turnover rates of captive West Indian manatees (Trichechus manatus) held in fresh and salt water.

    PubMed

    Ortiz, R M; Worthy, G A; Byers, F M

    1999-01-01

    The ability of West Indian manatees (Trichechus manatus) to move between fresh and salt water raises the question of whether manatees drink salt water. Water turnover rates were estimated in captive West Indian manatees using the deuterium oxide dilution technique. Rates were quantified in animals using four experimental treatments: (1) held in fresh water and fed lettuce (N=4), (2) held in salt water and fed lettuce (N=2), (3) acutely exposed to salt water and fed lettuce (N=4), and (4) chronically exposed to salt water with limited access to fresh water and fed sea grass (N=5). Animals held in fresh water had the highest turnover rates (145+/-12 ml kg-1 day-1) (mean +/- s.e.m.). Animals acutely exposed to salt water decreased their turnover rate significantly when moved into salt water (from 124+/-15 to 65+/-15 ml kg-1 day-1) and subsequently increased their turnover rate upon re-entry to fresh water (146+/-19 ml kg-1 day-1). Manatees chronically exposed to salt water had significantly lower turnover rates (21+/-3 ml kg-1 day-1) compared with animals held in salt water and fed lettuce (45+/-3 ml kg-1 day-1). Manatees chronically exposed to salt water and fed sea grass had very low turnover rates compared with manatees held in salt water and fed lettuce, which is consistent with a lack of mariposia. Manatees in fresh water drank large volumes of water, which may make them susceptible to hyponatremia if access to a source of Na+ is not provided.

  19. Estimation of water turnover rates of captive West Indian manatees (Trichechus manatus) held in fresh and salt water

    NASA Technical Reports Server (NTRS)

    Ortiz, R. M.; Worthy, G. A.; Byers, F. M.

    1999-01-01

    The ability of West Indian manatees (Trichechus manatus) to move between fresh and salt water raises the question of whether manatees drink salt water. Water turnover rates were estimated in captive West Indian manatees using the deuterium oxide dilution technique. Rates were quantified in animals using four experimental treatments: (1) held in fresh water and fed lettuce (N=4), (2) held in salt water and fed lettuce (N=2), (3) acutely exposed to salt water and fed lettuce (N=4), and (4) chronically exposed to salt water with limited access to fresh water and fed sea grass (N=5). Animals held in fresh water had the highest turnover rates (145+/-12 ml kg-1 day-1) (mean +/- s.e.m.). Animals acutely exposed to salt water decreased their turnover rate significantly when moved into salt water (from 124+/-15 to 65+/-15 ml kg-1 day-1) and subsequently increased their turnover rate upon re-entry to fresh water (146+/-19 ml kg-1 day-1). Manatees chronically exposed to salt water had significantly lower turnover rates (21+/-3 ml kg-1 day-1) compared with animals held in salt water and fed lettuce (45+/-3 ml kg-1 day-1). Manatees chronically exposed to salt water and fed sea grass had very low turnover rates compared with manatees held in salt water and fed lettuce, which is consistent with a lack of mariposia. Manatees in fresh water drank large volumes of water, which may make them susceptible to hyponatremia if access to a source of Na+ is not provided.

  20. Groundwater flow cycling between a submarine spring and an inland fresh water spring.

    PubMed

    Davis, J Hal; Verdi, Richard

    2014-01-01

    Spring Creek Springs and Wakulla Springs are large first magnitude springs that derive water from the Upper Floridan Aquifer. The submarine Spring Creek Springs are located in a marine estuary and Wakulla Springs are located 18 km inland. Wakulla Springs has had a consistent increase in flow from the 1930s to the present. This increase is probably due to the rising sea level, which puts additional pressure head on the submarine Spring Creek Springs, reducing its fresh water flow and increasing flows in Wakulla Springs. To improve understanding of the complex relations between these springs, flow and salinity data were collected from June 25, 2007 to June 30, 2010. The flow in Spring Creek Springs was most sensitive to rainfall and salt water intrusion, and the flow in Wakulla Springs was most sensitive to rainfall and the flow in Spring Creek Springs. Flows from the springs were found to be connected, and composed of three repeating phases in a karst spring flow cycle: Phase 1 occurred during low rainfall periods and was characterized by salt water backflow into the Spring Creek Springs caves. The higher density salt water blocked fresh water flow and resulted in a higher equivalent fresh water head in Spring Creek Springs than in Wakulla Springs. The blocked fresh water was diverted to Wakulla Springs, approximately doubling its flow. Phase 2 occurred when heavy rainfall resulted in temporarily high creek flows to nearby sinkholes that purged the salt water from the Spring Creek Springs caves. Phase 3 occurred after streams returned to base flow. The Spring Creek Springs caves retained a lower equivalent fresh water head than Wakulla Springs, causing them to flow large amounts of fresh water while Wakulla Springs flow was reduced by about half.

  1. Groundwater flow cycling between a submarine spring and an inland fresh water spring

    USGS Publications Warehouse

    Davis, J. Hal; Verdi, Richard

    2014-01-01

    Spring Creek Springs and Wakulla Springs are large first magnitude springs that derive water from the Upper Floridan Aquifer. The submarine Spring Creek Springs are located in a marine estuary and Wakulla Springs are located 18 km inland. Wakulla Springs has had a consistent increase in flow from the 1930s to the present. This increase is probably due to the rising sea level, which puts additional pressure head on the submarine Spring Creek Springs, reducing its fresh water flow and increasing flows in Wakulla Springs. To improve understanding of the complex relations between these springs, flow and salinity data were collected from June 25, 2007 to June 30, 2010. The flow in Spring Creek Springs was most sensitive to rainfall and salt water intrusion, and the flow in Wakulla Springs was most sensitive to rainfall and the flow in Spring Creek Springs. Flows from the springs were found to be connected, and composed of three repeating phases in a karst spring flow cycle: Phase 1 occurred during low rainfall periods and was characterized by salt water backflow into the Spring Creek Springs caves. The higher density salt water blocked fresh water flow and resulted in a higher equivalent fresh water head in Spring Creek Springs than in Wakulla Springs. The blocked fresh water was diverted to Wakulla Springs, approximately doubling its flow. Phase 2 occurred when heavy rainfall resulted in temporarily high creek flows to nearby sinkholes that purged the salt water from the Spring Creek Springs caves. Phase 3 occurred after streams returned to base flow. The Spring Creek Springs caves retained a lower equivalent fresh water head than Wakulla Springs, causing them to flow large amounts of fresh water while Wakulla Springs flow was reduced by about half.

  2. Accumulation pattern of pesticides in tropical fresh waters.

    PubMed

    Bhushan, R; Thapar, S; Mathur, R P

    1997-01-01

    High-performance liquid chromatography has been used to study the persistence of commonly used organophosphorus and carbamate pesticides-carbaryl, carbendazim, carbofuran, dimethoate, malathion and methyl parathion in river water in the presence of bottom sediment in laboratory aquaria. The fate of pesticides in water and sediment in pre- and post-monsoon water from three sources has been compared. It has been established that rapid degradation occurs once the pesticide leaches into sediment from water. Degradation was at a much faster rate in post-monsoon water and sediment. It was found that pH and organic matter content affect rate of decay.

  3. Fresh-water cementation of a 1,000-year-old oolite

    USGS Publications Warehouse

    Halley, R. B.; Harris, P. M.

    1979-01-01

    Calcite cementation of aragonite ooid sand is producing oolite on Joulters Cays, Bahamas. During the last 1,000 years, calcite cement has formed at an average rate of between 27 and 55 cm3 /m3 /yr and is derived from dissolution of ooid aragonite in fresh water. The dissolution-reprecipitation of carbonate minerals in the aquifer results in ground waters of unusually high Sr content. Sea water and mixtures of fresh and sea water appear to inhibit cementation. A pronounced cement fabric change occurs across the water table and has produced an obvious petrographic record of fresh-water diagenesis. Above the water table, cement is typically near grain contact positions, where water is held by capillarity; below the water table, cement is more randomly distributed around grains. At the water table a transition zone, 1 meter thick, marks the boundary between cement textures. No porosity reduction is associated with cementation; calcite cement precipitation is apparently compensated by an equal or greater amount of aragonite dissolution in the interval undergoing cementation. Permeability is more variable above the water table than below it, reflecting early channelling of flow patterns in the vadose zone. Effective permeability below the water table is one to two orders of magnitude higher than above the water table because of entrained gas in the vadose zone. This permeability difference promotes preservation of unstable minerals above the water table and continued diagenetic alteration below the water table.

  4. Infections Acquired via Fresh Water: From Lakes to Hot Tubs.

    PubMed

    Ayi, Bertha

    2015-12-01

    This chapter is unique in its focus on infections that are acquired in water. For those who like to swim and spend time in water parks and pools, the exposure to water and therefore the risk of infection is higher. Recreational water illnesses are illnesses related to recreation in water. Of these recreational water illnesses, infections are the most common because water laden with microorganisms or contaminated by human activity gains access to healthy tissue through the skin and body orifices. Infection occurs by inhalation, ingestion, or direct invasion of the respiratory and gastrointestinal tract. Gastrointestinal infections are the most common. This chapter discusses skin and soft tissue infections, ocular infections, urinary tract infections, pulmonary infections, central nervous system infections, and disseminated infections that can occur as people come into contact with natural nonmarine water bodies as well as manmade aquatic environments. Most of these infections are mild but can occasionally be life threatening. There is a focus on the latest methods to treat these infections. Pseudomonas aeruginosa is a very common pathogen in water. The chapter discusses P. aeruginosa dermatitis at length and also looks at keratitis and pneumonia caused by this organism. The chapter also discusses the latest treatments for primary amoebic meningoencephalitis, a severe life-threatening illness with a high mortality, caused by Naegleria fowleri. Finally, there is an in-depth discussion of the notorious gastrointestinal illnesses such as norovirus and Cryptosporidium parvum that can affect large numbers of people at a time. PMID:27337285

  5. Diagnosing death by drowning in fresh water using blood strontium as an indicator.

    PubMed

    Azparren, J E; Fernandez-Rodriguez, A; Vallejo, G

    2003-10-14

    The interpretation of the level of strontium (Sr) in blood has been demonstrated to be useful in the diagnosis of death by drowning occurred in sea water, but its use in fresh water drownings is not so evident because of the low Sr concentration present in most of fresh water media. In this paper, we show a survey of the results obtained in the casework analysis of Sr in ventricular blood used in the diagnosis of drowning in 144 bodies found immersed in fresh water over a period of 10 years. Thirty-two percent of the immersion cases examined could be diagnosed as drownings with a reasonable degree of confidence. It is thought that this percentage of positive diagnoses could be largely improved in the case of blood samples taken a few hours after death.

  6. Acid precipitation: Effects on fresh water ecosystems. (Latest citations from the Life Sciences Collection database). Published Search

    SciTech Connect

    Not Available

    1993-05-01

    The bibliography contains citations concerning the effects of acidification on fresh water ecosystems. Algae and diatom distribution, survival and reproduction rates of specific fish species under acid lake conditions, and tolerance to stress caused by acidic conditions in fresh water ecosystems are studied. Effects of water pH on trace metal toxicity to fresh water organisms are briefly considered. Control and reduction of acidification are excluded from this bibliography. (Contains 250 citations and includes a subject term index and title list.)

  7. COSOLVENT EFFECTS ON PHENANTHRENE SORPTION-DESORPTION ON A FRESH-WATER SEDIMENT

    EPA Science Inventory

    This study evaluated the effects of the water-miscible cosolvent methanol on the sorption-desorption of phenanthrene by the natural organic matter (NOM) of a fresh-water sediment. A biphasic pattern was observed in the relationship between the log of the carbon-normalized sorpti...

  8. Assessment and speciation of chlorine demand in fresh-cut produce wash water

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Production of high quality, fresh-cut produce is a key driver for the produce industry. A critical area of concern is the chlorinated wash water used during post-harvest processing in large industrial processing facilities. Predominantly using a batch process, wash water is recycled over 8hr shift...

  9. Competency-Based Curriculum for Prevocational Exploration. Marine/Fresh Water.

    ERIC Educational Resources Information Center

    Reese, Clara C.

    This competency-based curriculum is intended to help teachers of prevocational career exploration courses in West Virginia to present information about marine/fresh water occupations. The document is organized into five units: fisheries, life sciences, marine life cultivation, research, and water vehicle operation. Each unit consists of five to 15…

  10. Simulation and Evaluation of Pollution Load Reduction Scenarios for Water Environmental Management: A Case Study of Inflow River of Taihu Lake, China

    PubMed Central

    Zhang, Ruibin; Qian, Xin; Zhu, Wenting; Gao, Hailong; Hu, Wei; Wang, Jinhua

    2014-01-01

    In the beginning of the 21st century, the deterioration of water quality in Taihu Lake, China, has caused widespread concern. The primary source of pollution in Taihu Lake is river inflows. Effective pollution load reduction scenarios need to be implemented in these rivers in order to improve the water quality of Taihu Lake. It is important to select appropriate pollution load reduction scenarios for achieving particular goals. The aim of this study was to facilitate the selection of appropriate scenarios. The QUAL2K model for river water quality was used to simulate the effects of a range of pollution load reduction scenarios in the Wujin River, which is one of the major inflow rivers of Taihu Lake. The model was calibrated for the year 2010 and validated for the year 2011. Various pollution load reduction scenarios were assessed using an analytic hierarchy process, and increasing rates of evaluation indicators were predicted using the Delphi method. The results showed that control of pollution from the source is the optimal method for pollution prevention and control, and the method of “Treatment after Pollution” has bad environmental, social and ecological effects. The method applied in this study can assist for environmental managers to select suitable pollution load reduction scenarios for achieving various objectives. PMID:25207492

  11. Simulation and evaluation of pollution load reduction scenarios for water environmental management: a case study of inflow river of Taihu Lake, China.

    PubMed

    Zhang, Ruibin; Qian, Xin; Zhu, Wenting; Gao, Hailong; Hu, Wei; Wang, Jinhua

    2014-09-01

    In the beginning of the 21st century, the deterioration of water quality in Taihu Lake, China, has caused widespread concern. The primary source of pollution in Taihu Lake is river inflows. Effective pollution load reduction scenarios need to be implemented in these rivers in order to improve the water quality of Taihu Lake. It is important to select appropriate pollution load reduction scenarios for achieving particular goals. The aim of this study was to facilitate the selection of appropriate scenarios. The QUAL2K model for river water quality was used to simulate the effects of a range of pollution load reduction scenarios in the Wujin River, which is one of the major inflow rivers of Taihu Lake. The model was calibrated for the year 2010 and validated for the year 2011. Various pollution load reduction scenarios were assessed using an analytic hierarchy process, and increasing rates of evaluation indicators were predicted using the Delphi method. The results showed that control of pollution from the source is the optimal method for pollution prevention and control, and the method of "Treatment after Pollution" has bad environmental, social and ecological effects. The method applied in this study can assist for environmental managers to select suitable pollution load reduction scenarios for achieving various objectives.

  12. Aggregation and deposition of engineered TiO2 nanoparticles in natural fresh and brackish waters

    NASA Astrophysics Data System (ADS)

    Sillanpää, Markus; Paunu, Tiina-Mari; Sainio, Pirjo

    2011-07-01

    The use and thus environmental release potential of metal-based nanoparticles have rapidly increased. Due to their size-dependent new properties, the fate and effect of nanomaterial may differ from those of the conventional form of corresponding material. The agglomeration and sedimentation were studied by spiking the TiO2-P25 particles in natural fresh and brackish water samples. The natural waters were determined for conductivity, pH, salinity, total organic carbon, turbidity, common nutrients and trace elements. The hydrodynamic diameter and concentration of TiO2-P25 particle dispersions were monitored by using a dynamic light scattering and a spectrophotometer, respectively. The experiments were performed at two particle concentrations 100 mg/l and 1 mg/l (10 mg/l for deposition studies). The aggregation rates in brackish waters were clearly higher in higher initial concentration and the sedimentation of aggregates decreased the TiO2 concentration down to 20% and 80% of initial higher and lower concentrations, respectively. One fresh water sample favoured the destabilisation of TiO2-P25 particles whereas another fresh water sample stabilised the TiO2 particle dispersion. The aggregation had a strong dependence on the particle concentration. High ionic content of brackish water probably explains the formation of aggregates, whereas organic substances and pH may account for the different agglomeration behaviour in fresh waters.

  13. Cultivation of macroscopic marine algae and fresh water aquatic weeds

    SciTech Connect

    Ryther, J.H.

    1982-02-01

    The ORCA clone of the red seaweed Gracilaria tikvahiae has been in culture continuously for over two years. Yield for the past year has averaged 12 g ash-free dry wt/m/sup 2/ .day (17.5 t/a.y) in suspended 2600-1 aluminum tank cultures with four exchanges of enriched seawater per day and continuous aeration. Yields from nonintensive pond-bottom culture, similar to commercial Gracilaria culture methods in Taiwan, averaged 3 g afdw/m/sup 2/.day in preliminary experiments. Rope and spray cultures were not successful. Yields of water hyacinths from March 1978 to March 1979 averaged 25 g afdw/m/sup 2/.day (37 t/a.y). Season, nutrient availability (form and quantity) and stand density were found to affect the relative proportions of structural and nonstructural tissue in water hyacinths and thereby significantly affect digestibility of and methane production by the plants. Pennywort (Hydrocotyle) grew poorly in winter and its annual yield averaged only one-third that of water hyacinth. Water lettuce (Pistia) appears more comparable to hyacinths in preliminary studies and its yields will be monitored throughout a complete year. Stable, continuous anaerobic digestion of both water hyacinths and Gracilaria has been maintained with an average gas production from both species of 0.4 1/g volatile solids at 60% methane.

  14. Perspectives on Temperature in the Pacific Northwest's Fresh Waters

    SciTech Connect

    Coutant, C.C.

    1999-06-01

    This report provides a perspective on environmental water temperatures in the Pacific Northwest as they relate to the establishment of water temperature standards by the state and their review by the US Environmental Protection Agency. It is a companion to other detailed reviews of the literature on thermal effects on organisms important to the region. Many factors, both natural and anthropogenic, affect water temperatures in the region. Different environmental zones have characteristic temperatures and mechanisms that affect them. There are specific biotic adaptations to environmental temperatures. Life-cycle strategies of salmonids, in particular, are attuned to annual temperature patterns. Physiological and behavioral requirements on key species form the basis of present water temperature criteria, but may need to be augmented with more concern for environmental settings. There are many issues in the setting of standards, and these are discussed. There are also issues in compliance. Alternative temperature-regulating mechanisms are discussed, as are examples of actions to control water temperatures in the environment. Standards-setting is a social process for which this report should provide background and outline options, alternatives, limitations, and other points for discussion by those in the region.

  15. Formation of trichloromethane in chlorinated water and fresh-cut produce and as a result of reacting with citric acid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chlorine (sodium hypochlorite) is commonly used by the fresh produce industry to sanitize wash water, fresh and fresh-cut fruits and vegetables. However, possible formation of harmful chlorine by-products is a concern. The objectives of this study were to compare chlorine and chlorine dioxide in t...

  16. A Primer on Fresh Water: The Environmental Citizenship Series.

    ERIC Educational Resources Information Center

    Environment Canada, Ottawa (Ontario).

    Water is the lifeblood of the environment as no organisms can survive without it. This reference booklet is designed to help people make environmentally responsible decisions. The primer is targeted at the general public (grade 8 to post-secondary) to be used by educators, communities and organizations as well as individuals, as part of a learning…

  17. Survival of Candida albicans in tropical marine and fresh waters.

    PubMed Central

    Valdes-Collazo, L; Schultz, A J; Hazen, T C

    1987-01-01

    A survey of Candida albicans indicated that the organism was present at all sites sampled in a rain forest stream and in near-shore coastal waters of Puerto Rico. In the rain forest watershed no relationship existed between densities of fecal coliforms and densities of C. albicans. At two pristine sites in the rain forest watershed both C. albicans and Escherichia coli survived in diffusion chambers for extended periods of time. In near-shore coastal waters C. albicans and E. coli survival times in diffusion chambers were enhanced by effluent from a rum distillery. The rum distillery effluent had a greater effect on E. coli than on C. albicans survival in the diffusion chambers. These studies show that neither E. coli nor C. albicans organisms are good indicators of recent fecal contamination in tropical waters. It further demonstrates that pristine freshwater environments and marine waters receiving organic loading in the tropics can support densities of C. albicans which may be a health hazard. Images PMID:3310885

  18. Consumptive water use associated with food waste: case study of fresh mango in Australia

    NASA Astrophysics Data System (ADS)

    Ridoutt, B. G.; Juliano, P.; Sanguansri, P.; Sellahewa, J.

    2009-07-01

    In many parts of the world, freshwater is already a scarce and overexploited natural resource, raising concerns about global food security and damage to freshwater ecosystems. This situation is expected to intensify with the FAO estimating that world food production must double by 2050. Food chains must therefore become much more efficient in terms of consumptive water use. For the small and geographically well-defined Australian mango industry, having an average annual production of 44 692 t of marketable fresh fruit, the average virtual water content (sum of green, blue and gray water) at orchard gate was 2298 l kg-1. However, due to wastage in the distribution and consumption stages of the product life cycle, the average virtual water content of one kg of Australian-grown fresh mango consumed by an Australian household was 5218 l. This latter figure compares to an Australian-equivalent water footprint of 217 l kg-1, which is the volume of direct water use by an Australian household having an equivalent potential to contribute to water scarcity. Nationally, distribution and consumption waste in the food chain of Australian-grown fresh mango to Australian households represented an annual waste of 26.7 Gl of green water and 16.6 Gl of blue water. These findings suggest that interventions to reduce food chain waste will likely have as great or even greater impact on freshwater resource availability as other water use efficiency measures in agriculture and food production.

  19. Impact of domestic sewage on fresh water body.

    PubMed

    Shiddamallayya, N; Pratima, M

    2008-05-01

    In the present study various (physico-chemical) factors were assessed over a period of two years (from February 2002 to January 2004) to note the chemistry and quality of tank water in Bhalki town of Bidar. Physico-chemical factors like pH, dissolved oxygen, magnesium, chlorine, nitrite, sulphates and chemical oxygen demand were found with maximum concentration during summer season. Similarly, during monsoon season free carbon dioxide, alkalinity hardness, calcium, phosphate, silicon, total solids and biological oxygen demand; and in winter season organic matter were recorded. The concentrations viz., pH, hardness and nitrite were more compared to the potable water standard of WHO. The correlation matrix and dendrogram of physico-chemical factors have been computed and analysed. The positive co-relation coefficient observed between pH and magnesium, dissolved oxygen and hardness, free carbondioxide and calcium, alkalinity and nitrite, alkalinityand phosphate, alkalinity and biological oxygen demand, hardness and calcium, hardness and magnesium, magnesium and chlorine, nitrate and phosphate, nitrite and biological oxygen demand, phosphate and organic matter; and silicon and chemical oxygen demand. The dendrogram confirms chlorine, pH, hardness, silicon, total solids and sulphates are the key factors of the change in the chemistry of water body

  20. Exploring the limits of the terrestrial fresh water cycle

    NASA Astrophysics Data System (ADS)

    van der Ent, Ruud; Wang-Erlandsson, Lan; Keys, Patrick; Savenije, Hubert

    2014-05-01

    Precipitation is the ultimate source of life on this planet: it makes our crops grow, provides drinking water, feeds rivers and replenishes groundwater aquifers. Climate modelling studies estimate changes in precipitation due to increased greenhouse gas emissions and climate impact studies use those estimates as input to their (hydrological) models to predict future water availability and societal impact. However, humans also significantly alter the land surface by, for example, deforestation and irrigation, which is not frequently taken into account in our climate studies. Here, we present an overview of several papers in the field of moisture recycling, published by our group, that show the extent to which terrestrial evaporation influences terrestrial precipitation. It is found that 38% of the terrestrial precipitation originates from terrestrial evaporation and that 58% of all terrestrial evaporation recycles, and return again as terrestrial precipitation. Knowing this, it is clear that evaporation is not necessary a loss to the hydrological cycle. We show that in some cases even transpiration during the dry season can act as a moisture source for a distant region. To assess the vulnerability of a region to local and remote land use changes we propose the concept of the precipitationshed, which maps out a region's precipitation sources. Our results are useful in mapping out possible land use change threats, but also opportunities to safeguard our water resources in the Anthropocene.

  1. Developing the greatest Blue Economy: Water productivity, fresh water depletion, and virtual water trade in the Great Lakes basin

    NASA Astrophysics Data System (ADS)

    Mayer, Alex; Mubako, Stanley; Ruddell, Benjamin L.

    2016-06-01

    The Great Lakes basin hosts the world's most abundant surface fresh water reserve. Historically an industrial and natural resource powerhouse, the region has suffered economic stagnation in recent decades. Meanwhile, growing water resource scarcity around the world is creating pressure on water-intensive human activities. This situation creates the potential for the Great Lakes region to sustainably utilize its relative water wealth for economic benefit. We combine economic production and trade datasets with water consumption data and models of surface water depletion in the region. We find that, on average, the current economy does not create significant impacts on surface waters, but there is some risk that unregulated large water uses can create environmental flow impacts if they are developed in the wrong locations. Water uses drawing on deep groundwater or the Great Lakes themselves are unlikely to create a significant depletion, and discharge of groundwater withdrawals to surface waters offsets most surface water depletion. This relative abundance of surface water means that science-based management of large water uses to avoid accidentally creating "hotspots" is likely to be successful in avoiding future impacts, even if water use is significantly increased. Commercial water uses are the most productive, with thermoelectric, mining, and agricultural water uses in the lowest tier of water productivity. Surprisingly for such a water-abundant economy, the region is a net importer of water-derived goods and services. This, combined with the abundance of surface water, suggests that the region's water-based economy has room to grow in the 21st century.

  2. Production of Algal-based Biofuel from Non-fresh Water Sources

    NASA Astrophysics Data System (ADS)

    Sun, A. C.; Reno, M. D.

    2008-12-01

    A system dynamics model is developed to assess the availability and feasibility of non-traditional water sources from dairy wastewater, produced water from crude oil production and from coal-bed methane gas extraction for the production of algal-based biofuel. The conceptual framework is based on two locales within New Mexico, the San Juan basin in the northwest and the Permian basin in the southeast, where oil and gas drilling have increased considerably in the last ten years. The simulation framework contains an algal growth module, a dairy module, an oil production module, and a gas production module. Our preliminary investigation indicates a cyclical demand for non-fresh water due to the cyclical nature of algal biomass production and crop evapotranspiration. The wastewater from the dairy industry is not a feasible non-fresh water source because the agricultural water demand for cow's dry feed far exceeds the amount generated at the dairy. The uncertainty associated with the water demand for cow's dry matter intake is the greatest in this model. The oil and gas produced water, ignoring the quality, provides ample supply for water demand in algal biomass production. There remains work to address technical challenges associated with coupling the appropriate non-fresh water source to the local demand.

  3. Quantifying the Global Fresh Water Budget: Capabilities from Current and Future Satellite Sensors

    NASA Technical Reports Server (NTRS)

    Hildebrand, Peter; Zaitchik, Benjamin

    2007-01-01

    The global water cycle is complex and its components are difficult to measure, particularly at the global scales and with the precision needed for assessing climate impacts. Recent advances in satellite observational capabilities, however, are greatly improving our knowledge of the key terms in the fresh water flux budget. Many components of the of the global water budget, e.g. precipitation, atmospheric moisture profiles, soil moisture, snow cover, sea ice are now routinely measured globally using instruments on satellites such as TRMM, AQUA, TERRA, GRACE, and ICESat, as well as on operational satellites. New techniques, many using data assimilation approaches, are providing pathways toward measuring snow water equivalent, evapotranspiration, ground water, ice mass, as well as improving the measurement quality for other components of the global water budget. This paper evaluates these current and developing satellite capabilities to observe the global fresh water budget, then looks forward to evaluate the potential for improvements that may result from future space missions as detailed by the US Decadal Survey, and operational plans. Based on these analyses, and on the goal of improved knowledge of the global fresh water budget under the effects of climate change, we suggest some priorities for the future, based on new approaches that may provide the improved measurements and the analyses needed to understand and observe the potential speed-up of the global water cycle under the effects of climate change.

  4. Episodic fresh surface waters in the Eocene Arctic Ocean

    USGS Publications Warehouse

    Brinkhuis, H.; Schouten, S.; Collinson, M.E.; Sluijs, A.; Damste, J.S.S.; Dickens, G.R.; Huber, M.; Cronin, T. M.; Onodera, J.; Takahashi, K.; Bujak, J.P.; Stein, R.; Van Der Burgh, J.; Eldrett, J.S.; Harding, I.C.; Lotter, A.F.; Sangiorgi, F.; Cittert, H.V.K.V.; De Leeuw, J. W.; Matthiessen, J.; Backman, J.; Moran, K.

    2006-01-01

    It has been suggested, on the basis of modern hydrology and fully coupled palaeoclimate simulations, that the warm greenhouse conditions that characterized the early Palaeogene period (55-45 Myr ago) probably induced an intensified hydrological cycle with precipitation exceeding evaporation at high latitudes. Little field evidence, however, has been available to constrain oceanic conditions in the Arctic during this period. Here we analyse Palaeogene sediments obtained during the Arctic Coring Expedition, showing that large quantities of the free-floating fern Azolla grew and reproduced in the Arctic Ocean by the onset of the middle Eocene epoch (???50 Myr ago). The Azolla and accompanying abundant freshwater organic and siliceous microfossils indicate an episodic freshening of Arctic surface waters during an ???800,000-year interval. The abundant remains of Azolla that characterize basal middle Eocene marine deposits of all Nordic seas probably represent transported assemblages resulting from freshwater spills from the Arctic Ocean that reached as far south as the North Sea. The termination of the Azolla phase in the Arctic coincides with a local sea surface temperature rise from ???10??C to 13??C, pointing to simultaneous increases in salt and heat supply owing to the influx of waters from adjacent oceans. We suggest that onset and termination of the Azolla phase depended on the degree of oceanic exchange between Arctic Ocean and adjacent seas. ?? 2006 Nature Publishing Group.

  5. Impact of increasing inflow of warm Atlantic water on the sea-air exchange of carbon dioxide and methane in the Laptev Sea

    NASA Astrophysics Data System (ADS)

    Wâhlström, Iréne; Dieterich, Christian; Pemberton, Per; Meier, H. E. Markus

    2016-07-01

    The Laptev Sea is generally a sink for atmospheric carbon dioxide and a source of methane to the atmosphere. We investigate how sensitive the net sea-air exchange of carbon dioxide and methane in the Laptev Sea are to observed changes in the inflow of Atlantic water into the Arctic Ocean and in atmospheric conditions occurring after 1990. Using a time-dependent coupled physical-biogeochemical column model, both the physical and biogeochemical effects are investigated in a series of sensitivity experiments. The forcing functions are kept constant at 40 year climatological values except successively selected drivers that vary in time. Their effects are examined by comparing two periods, 1971-1989 and 1991-2009. We find that the flux of carbon dioxide is more sensitive to the increased Atlantic water inflow than the methane exchange. The increased volume transport of water in the Atlantic layer increases the ocean net uptake of carbon dioxide more than the warming of the incoming bottom water as the vertical advection is enhanced in the first case. The methane cycling is mainly affected by the increase in temperature, irrespective of whether the warming originates from the atmosphere or the incoming bottom water, causing increased outgassing to the atmosphere. In summary, our results suggest that the observed changes in the atmosphere and ocean potentially had a substantial impact on carbon dioxide uptake on the Siberian Shelf. However, the results suggest that the impact on the outgassing of methane might have been relatively modest compared to the interannual variability of sea-air fluxes of methane.

  6. Benthic plastic debris in marine and fresh water environments.

    PubMed

    Corcoran, Patricia L

    2015-08-01

    This review provides a discussion of the published literature concerning benthic plastic debris in ocean, sea, lake, estuary and river bottoms throughout the world. Although numerous investigations of shoreline, surface and near-surface plastic debris provide important information on plastic types, distribution, accumulation, and degradation, studies of submerged plastic debris have been sporadic in the past and have become more prominent only recently. The distribution of benthic debris is controlled mainly by combinations of urban proximity and its association with fishing-related activities, geomorphology, hydrological conditions, and river input. High density plastics, biofouled products, polymers with mineral fillers or adsorbed minerals, and plastic-metal composites all have the potential to sink. Once deposited on the bottoms of water basins and channels, plastics are shielded from UV light, thus slowing the degradation process significantly. Investigations of the interactions between benthic plastic debris and bottom-dwelling organisms will help shed light on the potential dangers of submerged plastic litter.

  7. The widespread threat of calcium decline in fresh waters.

    PubMed

    Jeziorski, Adam; Yan, Norman D; Paterson, Andrew M; Desellas, Anna M; Turner, Michael A; Jeffries, Dean S; Keller, Bill; Weeber, Russ C; McNicol, Don K; Palmer, Michelle E; McIver, Kyle; Arseneau, Kristina; Ginn, Brian K; Cumming, Brian F; Smol, John P

    2008-11-28

    Calcium concentrations are now commonly declining in softwater boreal lakes. Although the mechanisms leading to these declines are generally well known, the consequences for the aquatic biota have not yet been reported. By examining crustacean zooplankton remains preserved in lake sediment cores, we document near extirpations of calcium-rich Daphnia species, which are keystone herbivores in pelagic food webs, concurrent with declining lake-water calcium. A large proportion (62%, 47 to 81% by region) of the Canadian Shield lakes we examined has a calcium concentration approaching or below the threshold at which laboratory Daphnia populations suffer reduced survival and fecundity. The ecological impacts of environmental calcium loss are likely to be both widespread and pronounced. PMID:19039134

  8. Benthic plastic debris in marine and fresh water environments.

    PubMed

    Corcoran, Patricia L

    2015-08-01

    This review provides a discussion of the published literature concerning benthic plastic debris in ocean, sea, lake, estuary and river bottoms throughout the world. Although numerous investigations of shoreline, surface and near-surface plastic debris provide important information on plastic types, distribution, accumulation, and degradation, studies of submerged plastic debris have been sporadic in the past and have become more prominent only recently. The distribution of benthic debris is controlled mainly by combinations of urban proximity and its association with fishing-related activities, geomorphology, hydrological conditions, and river input. High density plastics, biofouled products, polymers with mineral fillers or adsorbed minerals, and plastic-metal composites all have the potential to sink. Once deposited on the bottoms of water basins and channels, plastics are shielded from UV light, thus slowing the degradation process significantly. Investigations of the interactions between benthic plastic debris and bottom-dwelling organisms will help shed light on the potential dangers of submerged plastic litter. PMID:26129903

  9. The widespread threat of calcium decline in fresh waters.

    PubMed

    Jeziorski, Adam; Yan, Norman D; Paterson, Andrew M; Desellas, Anna M; Turner, Michael A; Jeffries, Dean S; Keller, Bill; Weeber, Russ C; McNicol, Don K; Palmer, Michelle E; McIver, Kyle; Arseneau, Kristina; Ginn, Brian K; Cumming, Brian F; Smol, John P

    2008-11-28

    Calcium concentrations are now commonly declining in softwater boreal lakes. Although the mechanisms leading to these declines are generally well known, the consequences for the aquatic biota have not yet been reported. By examining crustacean zooplankton remains preserved in lake sediment cores, we document near extirpations of calcium-rich Daphnia species, which are keystone herbivores in pelagic food webs, concurrent with declining lake-water calcium. A large proportion (62%, 47 to 81% by region) of the Canadian Shield lakes we examined has a calcium concentration approaching or below the threshold at which laboratory Daphnia populations suffer reduced survival and fecundity. The ecological impacts of environmental calcium loss are likely to be both widespread and pronounced.

  10. Fluctuations of fresh-saline water interface and of water table induced by sea tides in unconfined aquifers

    NASA Astrophysics Data System (ADS)

    Levanon, Elad; Shalev, Eyal; Yechieli, Yoseph; Gvirtzman, Haim

    2016-10-01

    This study examines effects of tides on fluctuations of the fresh-saline water interface and the groundwater level in unconfined coastal aquifers using a two-dimensional numerical model. The time-lags of the simulated hydraulic heads and salinities fluctuations compared to sea level fluctuations are analyzed using cross-correlation analysis. The results show that both the fresh-saline water interface and the groundwater level are affected harmonically by sea tide fluctuations. However, significantly different time-lags are obtained between the hydraulic head in the deeper and upper parts of the aquifer, and between head and salinity in the fresh-saline water interface. The hydraulic head in the deeper part of the aquifer responses much faster to sea level fluctuations than in the upper part. Surprisingly, a similar difference is detected between the time-lag of the hydraulic head in the fresh-saline water interface and the time-lag of the salinity at the same location. Furthermore, the time-lag of the salinity in the fresh-saline water interface is similar to the time-lag of the water table. We suggest a comprehensive mechanism for tidal influence on the coastal groundwater system, in which two main processes act simultaneously. First, sea tide causes a pressure head wave which propagates into the saturated zone of the aquifer, governed by the diffusivity of the aquifer (Ks/Ss). Second, this pressure head wave is attenuated at the water table due to the unsaturated flow within the capillary fringe which occurs during groundwater level oscillations. Because the tidal forcing acts on the sea-floor boundary and the attenuation of the groundwater level due to capillary effect acts on the groundwater table, two dimensional distributions of time-lag and hydraulic head amplitude are created. The capillary effect in the unsaturated zone plays a key role not only in the water table fluctuations as shown previously, but also on the salinity fluctuations in the fresh

  11. Fresh and saline ground-water zones in the Punjab region, West Pakistan

    USGS Publications Warehouse

    Swarzenski, W.V.

    1968-01-01

    An extensive program of test drilling and water sampling, undertaken by the Water and Soils Investigation Division (WASID) of the West Pakistan Water and Power Development Authority (WAPDA) to evaluate hydrologic problems related to waterlogging and soil salinity, has furnished data for the delineation of fresh and saline ground-water zones in the Punjab region of West Pakistan. Fresh ground water containing generally less than 500 ppm (parts per million) of total dissolved solids is found in wide belts paralleling the major rivers and in other areas of ground-water recharge. The fresh groundwater zone of upper (northeastern) Rechna Doab, where annual precipitation in places exceeds 30 inches, is the most extensive of the Punjab region and attains a depth of 1,700 feet or more below land surface near Gujranwala. Fresh ground water adjacent to the Indus River extends locally to depths of about l,500 feet. Saline ground water occurs downgradient from sources of recharge, particularly in the central parts of the interfluvial areas. Also, available data indicate a gradual increase in mineralization with depth and distance from sources of fresh-water recharge. Thus, even extensive fresh-water zones appear to be underlain, at variable depths, by saline ground water in most of the Punjab region. The saline ground waters of the Punjab region do not constitute, however, a distinct salt-water body that can be defined in terms of stratigraphic position, sea-level datum, particular lithology, or by chemical character. The ground waters of the Punjab region are characterized by a gradation from calcium magnesium bicarbonate types, near the sources of recharge, to waters containing a dominant proportion of sodium. Water containing from 500 to 1,000 ppm is commonly of the sodium bicarbonate type, or it may be of the mixed type, having about equal proportions of the common anions (bicarbonate, chloride, and sulfate). With increasing mineralization from about 1,000 to 3,000 ppm

  12. [Underwater dive in fresh water complicated by a cardiorespiratory arrest on obstructive shock].

    PubMed

    Bourmanne, E; Jacobs, D; Caldow, M; El Kaissi, M

    2015-01-01

    We present the case of a french patient who dived in fresh water in Lac de l'Eau d'Heure on 8 December 2014. The 35 meters deep diving was complicated by an obstructive shock resulting from lung overpressure and decompression illness.

  13. Geoacoustic inversion of a shallow fresh-water environment

    NASA Astrophysics Data System (ADS)

    Stotts, Steven A.; Knobles, David P.; Koch, Robert A.; Piper, James N.; Keller, Jason A.

    2003-10-01

    A recent experiment was conducted at The University of Texas/Applied Research Laboratories test station located at Lake Travis, Austin, TX. Implosive (light bulb), explosive (firecracker), and tonal sources were recorded on a dual receiver system located on the bottom next to a range-independent underwater river channel. Inversion results of the broadband time series obtained over ranges less than 1.5 km were used to predict measured transmission loss at several tonal frequencies in the band from 250-1000 Hz. The average water depth was approximately 38 m along the channel during the experiment. Sound speed profiles were calculated from recorded temperature readings measured as a function of depth. Implosive source spectrums were measured and used to evaluate a model/data correlation cost function in a simulated annealing algorithm. Comparisons of inversion results using both a normal mode and a ray-based plane wave reflection coefficient forward model [Stotts et al., J. Acoust. Soc. Am. (submitted)] are discussed. Predicted transmission loss based on the inversion results are compared to the measured transmission loss. Differences between fluid and elastic layer bottom models will also be presented.

  14. Decapod crustaceans in fresh waters of southeastern Bahia, Brazil.

    PubMed

    de Almeida, Alexandre Oliveira; Coelho, Petrônio Alves; Luz, Joaldo Rocha; dos Santos, José Tiago Almeida; Ferraz, Neyva Ribeiro

    2008-09-01

    A total of 117 species of freshwater decapod crustaceans are known from Brazil. Knowledge regarding the fauna of Decapoda from inland waters in the state of Bahia, northeast Brazil, is incipient. In spite of its wide territory and rich hydrographic net, only 13 species of limnetic decapods have been reported from that state. The objective of this contribution was to survey decapod crustaceans of some hydrographic basins in southeastern Bahia. The material described herein was obtained in samplings conducted between 1997 and 2005. Voucher specimens were deposited in the carcinological collections of the Museu de Zoologia, Universidade Estadual de Santa Cruz, Ilhéus, Brazil, and Departamento de Oceanografia, Universidade Federal de Pernambuco, Recife, Brazil. A total of 13 species was collected. The carideans were represented by the atyids Atya scabra (Leach, 1815) and Potimirim potimirim (Müller, 1881) and the palaemonids Macrobrachium acanthurus (Wiegmann, 1836), M. amazonicum (Heller, 1862), M. carcinus (Linnaeus, 1758), M. heterochirus (Wiegmann, 1836), M. jelskii (Miers, 1877), M. olfersi (Wiegmann, 1836), and Palaemon (Palaemon) pandaliformis (Stimpson, 1871). The brachyurans were represented by the portunids Callinectes bocourti A. Milne-Edwards, 1879 and C. sapidus Rathbun, 1895, the trichodactylid Trichodactylus fluviatilis Latreille, 1828 and the panopeid Panopeus rugosus A. Milne-Edwards, 1881. Macrobrachium heterochirus represents a new record from Bahia, and M. amazonicum is reported for the first time in southeast Bahia. The occurrence of two extreme different forms of T. fluviatilis was observed. Form A is characterized by the frontal margin of carapace bordered by conspicuous granules, the anterolateral margin provided with developed teeth plus granules, and the posterolateral margin provided with granulation similar to that found on the front. In form B the frontal margin is smooth or has an inconspicuous granulation; the anterolateral margin is

  15. Decapod crustaceans in fresh waters of southeastern Bahia, Brazil.

    PubMed

    de Almeida, Alexandre Oliveira; Coelho, Petrônio Alves; Luz, Joaldo Rocha; dos Santos, José Tiago Almeida; Ferraz, Neyva Ribeiro

    2008-09-01

    A total of 117 species of freshwater decapod crustaceans are known from Brazil. Knowledge regarding the fauna of Decapoda from inland waters in the state of Bahia, northeast Brazil, is incipient. In spite of its wide territory and rich hydrographic net, only 13 species of limnetic decapods have been reported from that state. The objective of this contribution was to survey decapod crustaceans of some hydrographic basins in southeastern Bahia. The material described herein was obtained in samplings conducted between 1997 and 2005. Voucher specimens were deposited in the carcinological collections of the Museu de Zoologia, Universidade Estadual de Santa Cruz, Ilhéus, Brazil, and Departamento de Oceanografia, Universidade Federal de Pernambuco, Recife, Brazil. A total of 13 species was collected. The carideans were represented by the atyids Atya scabra (Leach, 1815) and Potimirim potimirim (Müller, 1881) and the palaemonids Macrobrachium acanthurus (Wiegmann, 1836), M. amazonicum (Heller, 1862), M. carcinus (Linnaeus, 1758), M. heterochirus (Wiegmann, 1836), M. jelskii (Miers, 1877), M. olfersi (Wiegmann, 1836), and Palaemon (Palaemon) pandaliformis (Stimpson, 1871). The brachyurans were represented by the portunids Callinectes bocourti A. Milne-Edwards, 1879 and C. sapidus Rathbun, 1895, the trichodactylid Trichodactylus fluviatilis Latreille, 1828 and the panopeid Panopeus rugosus A. Milne-Edwards, 1881. Macrobrachium heterochirus represents a new record from Bahia, and M. amazonicum is reported for the first time in southeast Bahia. The occurrence of two extreme different forms of T. fluviatilis was observed. Form A is characterized by the frontal margin of carapace bordered by conspicuous granules, the anterolateral margin provided with developed teeth plus granules, and the posterolateral margin provided with granulation similar to that found on the front. In form B the frontal margin is smooth or has an inconspicuous granulation; the anterolateral margin is

  16. Production of algal-based biofuel using non-fresh water sources.

    SciTech Connect

    Sun, Amy Cha-Tien; Reno, Marissa Devan

    2007-09-01

    The goal of this LDRD involves development of a system dynamics model to understand the interdependencies between water resource availability and water needs for production of biofuels. Specifically, this model focuses on availability and feasibility of non-traditional water sources from dairy wastewater, produced water from crude oil production and from coal-bed methane gas extraction for the production of algal-based biofuel. The conceptual simulation framework and historical data are based on two locales within New Mexico, the San Juan basin in the northwest and the Permian basin in the southeast, where oil and gas drilling have increased considerably in the last ten years. The overall water balance ignores both transportation options and water chemistry and is broken down by county level. The resulting model contains an algal growth module, a dairy module, an oil production module, and a gas production module. A user interface is also created for controlling the adjustable parameters in the model. Our preliminary investigation indicates a cyclical demand for non-fresh water due to the cyclical nature of algal biomass production and crop evapotranspiration. The wastewater from the dairy industry is not a feasible non-fresh water source because the agricultural water demand for cow's dry feed far exceeds the amount generated at the dairy. The uncertainty associated with the water demand for cow's dry matter intake is the greatest in this model. The oil- and gas-produced water, ignoring the quality, provides ample supply for water demand in algal biomass production. There remains work to address technical challenges associated with coupling the appropriate non-fresh water source to the local demand.

  17. Renal effects of fresh water-induced hypo-osmolality in a marine adapted seal

    NASA Technical Reports Server (NTRS)

    Ortiz, R. M.; Wade, C. E.; Costa, D. P.; Ortiz, C. L.

    2002-01-01

    With few exceptions, marine mammals are not exposed to fresh water; however quantifying the endocrine and renal responses of a marine-adapted mammal to the infusion of fresh water could provide insight on the evolutionary adaptation of kidney function and on the renal capabilities of these mammals. Therefore, renal function and hormonal changes associated with fresh water-induced diuresis were examined in four, fasting northern elephant seal ( Mirounga angustirostris) (NES) pups. A series of plasma samples and 24-h urine voids were collected prior to (control) and after the infusion of water. Water infusion resulted in an osmotic diuresis associated with an increase in glomerular filtration rate (GFR), but not an increase in free water clearance. The increase in excreted urea accounted for 96% of the increase in osmotic excretion. Following infusion of fresh water, plasma osmolality and renin activity decreased, while plasma aldosterone increased. Although primary regulators of aldosterone release (Na(+), K(+) and angiotensin II) were not significantly altered in the appropriate directions to individually stimulate aldosterone secretion, increased aldosterone may have resulted from multiple, non-significant changes acting in concert. Aldosterone release may also be hypersensitive to slight reductions in plasma Na(+), which may be an adaptive mechanism in a species not known to drink seawater. Excreted aldosterone and urea were correlated suggesting aldosterone may regulate urea excretion during hypo-osmotic conditions in NES pups. Urea excretion appears to be a significant mechanism by which NES pups sustain electrolyte resorption during conditions that can negatively affect ionic homeostasis such as prolonged fasting.

  18. Effects of temperature on electrolyte balance and osmoregulation of the alewife (Alosa pseudoharengus) in fresh and sea water

    USGS Publications Warehouse

    Stanley, Jon G.; Colby, Peter J.

    1971-01-01

    In the laboratory, alewife mortalities caused by increasing or decreasing temperatures were about equal in fresh water and sea water. These findings suggest that salinity does not modify the capacity of alewives to tolerate acute temperature stress.

  19. Ozonated water extends the shelf life of fresh-cut lettuce.

    PubMed

    Beltrán, David; Selma, María V; Marín, Alicia; Gil, María I

    2005-07-13

    The use of ozonated water as a sanitizer to extend the shelf life of fresh-cut lettuce and the effect on the antioxidant constituents (polyphenols and vitamin C) were investigated. Fresh-cut iceberg lettuce (Lactuca sativa L.) was washed at 4 degrees C using three different ozonated water dips [10, 20, and 10 activated by ultraviolet C (UV-C) light mg L(-1) min total ozone dose], and the dips were compared with water and chlorine rinses. Treated lettuce was packaged in air or active modified atmosphere packaging (MAP) (4 kPa of O2 + 12 kPa of CO2 balanced with N2) and stored for 13 days at 4 degrees C. Despite its strong oxidizing activity, ozonated water did not stimulate the respiratory activity of fresh-cut lettuce. Moreover, ozonated water maintained the initial visual appearance of fresh-cut lettuce and controlled browning during storage in air. Initially, ozonated water and chlorine reduced the total mesophilic population by 1.6 and 2.1 log, respectively, when compared with water. Active MAP was effective in controlling total microbial growth, achieving 2.0 log reduction in relation to samples stored in air at the end of storage. On the other hand, active MAP caused a 2.0-3.5 reduction of coliforms on sanitized samples compared with water-washed samples. The most efficient treatments were ozone 20 and ozone 10 activated by UV-C, which were as effective as chlorine. Changes in individual phenolic compounds were independent of the washing treatments. In air, chlorogenic and isochlorogenic acid contents increased noticeably after 13 days while monocaffeoyltartaric and dicaffeoyltartaric acids remained unchanged. MAP effectively suppressed accumulation of caffeoylquinic derivatives, whereas caffeoyltartaric derivatives decreased during MAP storage to reach similar levels. The content of vitamin C (ascorbic acid and dehydroascorbic acid) decreased during storage, particularly under MAP. Ozonated water could be an alternative sanitizer to chlorine for fresh

  20. Rehydration after exercise with fresh young coconut water, carbohydrate-electrolyte beverage and plain water.

    PubMed

    Saat, Mohamed; Singh, Rabindarjeet; Sirisinghe, Roland Gamini; Nawawi, Mohd

    2002-03-01

    This is to cross-over study to assess the effectiveness of fresh young coconut water (CW), and carbohydrate-electrolyte beverage (CEB) compared with plain water (PW) for whole body rehydration and blood volume (BV) restoration during a 2 h rehydration period following exercise-induced dehydration. Eight healthy male volunteers (mean age and VO2max of 22.4 +/- 3.3 years and 45.8 +/- 1.5 ml min kg-1 respectively) exercised at 60% of VO2max in the heat (31.1 +/- 0.03 degrees C, 51.4 +/- 0.1% rh) until 2.78 +/- 0.06% (1.6 +/- 0.1 kg) of their body weight (BW) was lost. After exercise, the subjects sat for 2 h in a thermoneutral environment (22.5 +/- 0.1 degrees C; 67.0 +/- 1.0% rh) and drank a volume of PW, CW and CEB on different occasions representing 120% of the fluid loss. A blood and urine sample, and the body weight of each subject was taken before and after exercise and at 30 min intervals throughout a rehydration period. Each subject remained fasted throughout rehydration. Each fluid was consumed in three portions in separate trials representing 50% (781 +/- 47 ml), 40% (625 +/- 33 ml) and 30% (469 +/- 28 ml) of the 120% fluid loss at 0, 30 and 60 min of the 2 h rehydration period, respectively. The drinks given were randomised. In all the trials the subjects were somewhat hypohydrated (range 0.08-0.18 kg BW below euhydrated BW; p > 0.05) after a 2 h rehydration period since additional water and BW were lost as a result of urine formation, respiration, sweat and metabolism. The percent of body weight loss that was regained (used as index of percent rehydration) during CW, PW, and CEB trials was 75 +/- 5%, 73 +/- 5% and 80 +/- 4% respectively, but was not statistically different between trials. The rehydration index, which provided an indication of how much of what was actually ingested was used for body weight restoration, was again not different statistically between trials (1.56 +/- 0.14, 1.36 +/- 0.13 and 1.71 +/- 0.21 for CW, CEB and PW respectively

  1. Water quality of the Boca Raton canal system and effects of the Hillsboro Canal inflow, southeastern Florida, 1990-91

    USGS Publications Warehouse

    McKenzie, D.J.

    1995-01-01

    The City of Boca Raton in southeastern Palm Beach County, Florida, is an urban residential area that has sustained a constant population growth with subsequent increase in water use. The Boca Raton network of canals is controlled to provide for drainage of excess water, to maintain proper coastal ground-water levels to prevent saltwater intrusion, and to recharge the surficial aquifer system from which the city withdraws potable water. Most of the water supplied to the Boca Raton canal system and the surficial aquifer system, other than rainfall and runoff, is pumped from the Hillsboro Canal. The Biscayne aquifer, principal hydrogeologic unit of the surficial aquifer system, is highly permeable and there is a close relation between water levels in the canals and the aquifer. The amount of water supplied by seepage from the conservation areas is unknown. Because the Hillsboro Canal flows from Lake Okeechobee and Water Conservation Areas 1 and 2, which are places of more highly mineralized ground water and surface water, the canal is a possible source of contamination. Water samples were collected at 10 canal sites during wet and dry seasons and analyzed for major inorganic ions and related characteristics, nutrients, and trace elements. All concentrations were generally within or less than the drinking-water standards established by the Florida Department of Environmental Protection. The high concentrations of sodium and chloride that were detected in samples from the Boca Raton canal system are probably from the more mineralized water of the Hillsboro Canal. Other water-quality data, gathered from various sources from 1982 through 1991, did not indicate any significant changes nor trends. The effects of the Hillsboro Canal on the water quality of the Boca Raton canal system are indicated by increased concentrations of sodium, chloride, dissolved solids, and total organic carbon. Concentrations of the constituents in the canal water generally decrease with distance

  2. Salinization of a fresh palaeo-ground water resource by enhanced recharge.

    PubMed

    Leaney, F W; Herczeg, A L; Walker, G R

    2003-01-01

    Deterioration of fresh ground water resources caused by salinization is a growing issue in many arid and semi-arid parts of the world. We discuss here the incipient salinization of a 10(4) km2 area of fresh ground water (<3,000 mg/L) in the semiarid Murray Basin of Australia caused by widespread changes in land use. Ground water 14C concentrations and unsaturated zone Cl soil water inventories indicate that the low salinity ground water originated mainly from palaeo-recharge during wet climatic periods more than 20,000 years ago. However, much of the soil water in the 20 to 60 m thick unsaturated zone throughout the area is generally saline (>15,000 mg/L) because of relatively high evapotranspiration during the predominantly semiarid climate of the last 20,000 years. Widespread clearing of native vegetation over the last 100 years and replacement with crops and pastures leads to enhancement of recharge rates that progressively displace the saline soil-water from the unsaturated zone into the ground water. To quantify the impact of this new hydrologic regime, a one-dimensional model that simulates projected ground water salinities as a function of depth to ground water, recharge rates, and soil water salt inventory was developed. Results from the model suggest that, in some areas, the ground water salinity within the top 10 m of the water table is likely to increase by a factor of 2 to 6 during the next 100 years. Ground water quality will therefore potentially degrade beyond the point of usefulness well before extraction of the ground water exhausts the resource.

  3. Of all the planet's renewable resources, fresh water may be the most unforgiving.

    PubMed

    1994-01-01

    Access to water is essential to social and economic development and the stability of cultures and civilizations throughout the world historically. The UN Commission on Sustainable Development in mid-1993 emphasized the importance of transfer of technology to poor countries for improvement in water quality. Less attention has been given to the issue of water availability. The amount of fresh water is finite. The capacity for storage of water has increased over time, but commodity expansion has not improved. Salinization processes have proven to be too costly in dollars, pollution, and nonrenewable fossil fuels. As population grows, the average amount of fresh water available declines. Improvements can only be made in efficiency of usage or conservation. Per capita use of water doubled to 800 cubic meters per person per year. But global use of water increased by 4 times in 50 years. Only 2.5% of the world's 1.4 billion cubic kilometers of water is fit for drinking, crops, or most industrial uses. In Africa and the Middle East water resources are declining in availability and quality. An important feature of water resources is the extent of replenishment in the hydrologic cycle. Water availability from rain and snow amounts to about 113,000 cubic kilometers yearly, of which 72,000 evaporates. Aquifers, rivers, and oceans are renewed with the remaining 41,000 cu km. About 50% returns to oceans and 1/8 is too far from human habitation for use. Estimates of renewable freshwater average 9-14,000 cu km yearly, and a substantial amount is needed to sustain ecosystems in rivers, wetlands, and coastal waters. Internal resources within each country may amount to only about 20% of potential water resources, due to water storage suitability of the land and the extent and condition of infrastructure.

  4. Of all the planet's renewable resources, fresh water may be the most unforgiving.

    PubMed

    1994-01-01

    Access to water is essential to social and economic development and the stability of cultures and civilizations throughout the world historically. The UN Commission on Sustainable Development in mid-1993 emphasized the importance of transfer of technology to poor countries for improvement in water quality. Less attention has been given to the issue of water availability. The amount of fresh water is finite. The capacity for storage of water has increased over time, but commodity expansion has not improved. Salinization processes have proven to be too costly in dollars, pollution, and nonrenewable fossil fuels. As population grows, the average amount of fresh water available declines. Improvements can only be made in efficiency of usage or conservation. Per capita use of water doubled to 800 cubic meters per person per year. But global use of water increased by 4 times in 50 years. Only 2.5% of the world's 1.4 billion cubic kilometers of water is fit for drinking, crops, or most industrial uses. In Africa and the Middle East water resources are declining in availability and quality. An important feature of water resources is the extent of replenishment in the hydrologic cycle. Water availability from rain and snow amounts to about 113,000 cubic kilometers yearly, of which 72,000 evaporates. Aquifers, rivers, and oceans are renewed with the remaining 41,000 cu km. About 50% returns to oceans and 1/8 is too far from human habitation for use. Estimates of renewable freshwater average 9-14,000 cu km yearly, and a substantial amount is needed to sustain ecosystems in rivers, wetlands, and coastal waters. Internal resources within each country may amount to only about 20% of potential water resources, due to water storage suitability of the land and the extent and condition of infrastructure. PMID:12179243

  5. Effects of land use on fresh waters: Agriculture, forestry, mineral exploitation, urbanisation

    SciTech Connect

    Solbe, J.F.

    1986-01-01

    This book offers a broad consideration of the effects of land use on fresh waters above and below ground. Experts address a wide range of issues in relation to the four major uses of land. Taken from an international conference held at the University of Stirling in 1985, coverage includes sewerage and waste-water treatment, long-term contamination of aquifers below cities, mineral exploitation, use of water in food production, wood production and more. Remedies and areas requiring further study are outlined.

  6. Relative Recovery of Thermal Energy and Fresh Water in Aquifer Storage and Recovery Systems.

    PubMed

    Miotliński, K; Dillon, P J

    2015-01-01

    This paper explores the relationship between thermal energy and fresh water recoveries from an aquifer storage recovery (ASR) well in a brackish confined aquifer. It reveals the spatial and temporal distributions of temperature and conservative solutes between injected and recovered water. The evaluation is based on a review of processes affecting heat and solute transport in a homogeneous aquifer. In this simplified analysis, it is assumed that the aquifer is sufficiently anisotropic to inhibit density-affected flow, flow is axisymmetric, and the analysis is limited to a single ASR cycle. Results show that the radial extent of fresh water at the end of injection is greater than that of the temperature change due to the heating or cooling of the geological matrix as well as the interstitial water. While solutes progress only marginally into low permeability aquitards by diffusion, conduction of heat into aquitards above and below is more substantial. Consequently, the heat recovery is less than the solute recovery when the volume of the recovered water is lower than the injection volume. When the full volume of injected water is recovered the temperature mixing ratio divided by the solute mixing ratio for recovered water ranges from 0.95 to 0.6 for ratios of maximum plume radius to aquifer thickness of 0.6 to 4.6. This work is intended to assist conceptual design for dual use of ASR for conjunctive storage of water and thermal energy to maximize the potential benefits.

  7. Effects of small-scale vertical variations in well-screen inflow rates and concentrations of organic compounds on the collection of representative ground-water-quality samples

    USGS Publications Warehouse

    Gibs, Jacob; Brown, G. Allan; Turner, Kenneth S.; MacLeod, Cecilia L.; Jelinski, James; Koehnlein, Susan A.

    1993-01-01

    Because a water sample collected from a well is an integration of water from different depths along the well screen, measured concentrations can be biased if analyte concentrations are not uniform along the length of the well screen. The resulting concentration in the sample, therefore, is a function of variations in well-screen inflow rate and analyte concentration with depth. A multiport sampler with seven short screened intervals was designed and used to investigate small-scale vertical variations in water chemistry and aquifer hydraulic conductivity in ground water contaminated by leaded gasoline at Galloway Township, Atlantic County, New Jersey. The multiport samplers were used to collect independent samples from seven intervals within the screened zone that were flow-rate weighted and integrated to simulate a 5-foot-long, 2.375-inch- outside-diameter conventional wire-wound screen. The integration of the results of analyses of samples collected from two multiport samplers showed that a conventional 5-foot-long well screen would integrate contaminant concentrations over its length and resulted in an apparent contaminant concentration that was a little as 28 percent of the maximum concentration observed in the multiport sampler.

  8. Purification and partial characterization of haloperoxidase from fresh water algae Cladophora glomerata.

    PubMed

    Verdel, E F; Kline, P C; Wani, S; Woods, A E

    2000-02-01

    Many haloperoxidases have been purified from diverse organisms, including lichen, fungi, bacteria, and marine algae. In this study a haloperoxidase was purified from the fresh water algae, Cladophora glomerata, by homogenization and centrifugation, ammonium sulfate fractionation, ion-exchange and gel filtration chromatography. Molecular weight was determined by SDS-PAGE and by size exclusion HPLC and found to be approximately 43 kDa. The isoelectric point was determined to be approximately 8.1 by isoelectric focusing. The UV spectrum of the peroxidase showed a strong absorbance in the Soret band indicating a heme protein, unlike vanadium-dependent haloperoxidases from marine algae. Fresh water algal haloperoxidase catalyzed the iodination of tyrosine at a pH of 3.1. This haloperoxidase also catalyzes the oxidation of guaiacol and oxidation of iodide as well as catalyzing a peroxide-dependent reaction in both the presence and absence of chloride and bromide ions.

  9. Fresh-water discharge salinity relations in the tidal Delaware River

    USGS Publications Warehouse

    Keighton, Walter B.

    1966-01-01

    Sustained flows of fresh water greater than 3,500, 4,400, and 5,300 cubic feet per second into the Delaware River estuary at Trenton, NJ assure low salinity at League Island, Eddystone, and Marcus Hook, respectively. When the discharge at Trenton is less than these critical values, salinity is very sensitive to change in discharge, so that a relatively small decrease in fresh-water discharge results in a relatively great increase in salinity. Comparison of the discharge-salinity relations observed for the 14-year period August 1949-December 1963 with relations proposed by other workers but based on other time periods indicate that such relations change with time and that salinity is affected not only by discharge but also by dredging; construction of breakwater, dikes, and tidal barriers; changing sea level; tidal elevation; tidal range; and wind intensity and direction.

  10. Vegetation dynamics in response to water inflow rates and fire in a brackish Typha domingensis Pers. marsh in the delta of the Colorado River, Mexico

    USGS Publications Warehouse

    Mexicano, Lourdes; Nagler, Pamela L.; Zamora-Arroyo, Francisco; Glenn, Edward P.

    2012-01-01

    The Cienega de Santa Clara is a 5600 ha, anthropogenic wetland in the delta of the Colorado River in Mexico. It is the inadvertent creation of the disposal of brackish agricultural waste water from the U.S. into the intertidal zone of the river delta in Mexico, but has become an internationally important wetland for resident and migratory water birds. We used high resolution Quickbird and WorldView-2 images to produce seasonal vegetation maps of the Cienega before, during and after a test run of the Yuma Desalting Plant, which will remove water from the inflow stream and replace it with brine. We also used moderate resolution, 16-day composite NDVI imagery from the Moderate Resolution Imaging Spectrometer (MODIS) sensors on the Terra satellite to determine the main factors controlling green vegetation density over the years 2000–2011. The marsh is dominated by Typha domingensis Pers. with Phragmites australis (Cav.) Trin. Ex Steud. as a sub-dominant species in shallower marsh areas. The most important factor controlling vegetation density was fire. Spring fires in 2006 and 2011 were followed by much more rapid green-up of T. domingensis in late spring and 30% higher peak summer NDVI values compared to non-fire years (P < 0.001). Fires removed thatch and returned nutrients to the water, resulting in more vigorous vegetation growth compared to non-fire years. The second significant (P < 0.01) factor controlling NDVI was flow rate of agricultural drain water from the U.S. into the marsh. Reduced summer flows in 2001 due to canal repairs, and in 2010 during the YDP test run, produced the two lowest NDVI values of the time series from 2000 to 2011 (P < 0.05). Salinity is a further determinant of vegetation dynamics as determined by greenhouse experiments, but was nearly constant over the period 2000–2011, so it was not a significant variable in regression analyses. It is concluded that any reduction in inflow volumes will result in a linear decrease in green foliage

  11. Environmental Levels Of 129I Present In Bovine Thyroid And Fresh Water In Argentina

    SciTech Connect

    Negri, A. E.; Arazi, A.; Carnellia, P. F. F.; Barbara, E. de; Figueira, J. M.; Fimiani, L.; Heimanna, D. M.; Zalazara, L.; Fernandez Niello, J.; La Gamma, A. M.; Wallner, A.

    2010-08-04

    Concentrations of {sup 129}I in bovine thyroid and fresh water samples coming from all over Argentina were analyzed by Accelerator Mass Spectrometry (AMS) and total iodine present in samples by Gas Chromatography (GC) and Inductive Coupled Plasma Mass Spectrometry (ICP-MS), respectively. Once we complete this study, it will be the first set of data of this kind from an extended region of the south American subcontinent.

  12. Soil moisture and excavation behaviour in the Chaco leaf-cutting ant (Atta vollenweideri): digging performance and prevention of water inflow into the nest.

    PubMed

    Pielström, Steffen; Roces, Flavio

    2014-01-01

    The Chaco leaf-cutting ant Atta vollenweideri is native to the clay-heavy soils of the Gran Chaco region in South America. Because of seasonal floods, colonies are regularly exposed to varying moisture across the soil profile, a factor that not only strongly influences workers' digging performance during nest building, but also determines the suitability of the soil for the rearing of the colony's symbiotic fungus. In this study, we investigated the effects of varying soil moisture on behaviours associated with underground nest building in A. vollenweideri. This was done in a series of laboratory experiments using standardised, plastic clay-water mixtures with gravimetric water contents ranging from relatively brittle material to mixtures close to the liquid limit. Our experiments showed that preference and group-level digging rate increased with increasing water content, but then dropped considerably for extremely moist materials. The production of vibrational recruitment signals during digging showed, on the contrary, a slightly negative linear correlation with soil moisture. Workers formed and carried clay pellets at higher rates in moist clay, even at the highest water content tested. Hence, their weak preference and low group-level excavation rate observed for that mixture cannot be explained by any inability to work with the material. More likely, extremely high moistures may indicate locations unsuitable for nest building. To test this hypothesis, we simulated a situation in which workers excavated an upward tunnel below accumulated surface water. The ants stopped digging about 12 mm below the interface soil/water, a behaviour representing a possible adaptation to the threat of water inflow field colonies are exposed to while digging under seasonally flooded soils. Possible roles of soil water in the temporal and spatial pattern of nest growth are discussed.

  13. Soil Moisture and Excavation Behaviour in the Chaco Leaf-Cutting Ant (Atta vollenweideri): Digging Performance and Prevention of Water Inflow into the Nest

    PubMed Central

    Pielström, Steffen; Roces, Flavio

    2014-01-01

    The Chaco leaf-cutting ant Atta vollenweideri is native to the clay-heavy soils of the Gran Chaco region in South America. Because of seasonal floods, colonies are regularly exposed to varying moisture across the soil profile, a factor that not only strongly influences workers' digging performance during nest building, but also determines the suitability of the soil for the rearing of the colony's symbiotic fungus. In this study, we investigated the effects of varying soil moisture on behaviours associated with underground nest building in A. vollenweideri. This was done in a series of laboratory experiments using standardised, plastic clay-water mixtures with gravimetric water contents ranging from relatively brittle material to mixtures close to the liquid limit. Our experiments showed that preference and group-level digging rate increased with increasing water content, but then dropped considerably for extremely moist materials. The production of vibrational recruitment signals during digging showed, on the contrary, a slightly negative linear correlation with soil moisture. Workers formed and carried clay pellets at higher rates in moist clay, even at the highest water content tested. Hence, their weak preference and low group-level excavation rate observed for that mixture cannot be explained by any inability to work with the material. More likely, extremely high moistures may indicate locations unsuitable for nest building. To test this hypothesis, we simulated a situation in which workers excavated an upward tunnel below accumulated surface water. The ants stopped digging about 12 mm below the interface soil/water, a behaviour representing a possible adaptation to the threat of water inflow field colonies are exposed to while digging under seasonally flooded soils. Possible roles of soil water in the temporal and spatial pattern of nest growth are discussed. PMID:24748382

  14. [Accelerated senescence of fresh-cut Chinese water chestnut tissues in relation to hydrogen peroxide accumulation].

    PubMed

    Peng, Li-Tao; Jiang, Yue-Ming; Yang, Shu-Zhen; Pan, Si-Yi

    2005-10-01

    Accelerated senescence of fresh-cut Chinese water chestnut (CWC) tissues in relation to active oxygen species (AOS) metabolism was investigated. Fresh-cut CWC (2 mm thick) and intact CWC were stored at 4 degrees C in trays wrapped with plastic films. Changes in superoxide anion production rate, activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) were monitored, while contents of hydrogen peroxide, ascorbic acid, MDA as well as electrolyte leakage were measured. Fresh-cutting of CWC induced activities of SOD, CAT and APX to a certain extent (Fig. 2B and Fig. 3), but simultaneously stimulated superoxide anion production markedly (Fig. 2A), enhanced hydrogen peroxide accumulation and accelerated loss in ascorbic acid (Figs. 4 and 5), which resulted in increased lipid peroxidation indicated by malondialdehyde (MDA) content and electrolyte leakage (Fig. 1). Statistics analysis indicated that there was a significantly positive correlation among hydrogen peroxide accumulation, MDA content and electrolyte leakage (Table 1). Histochemical detection with 3, 3'-diaminobenzidine further demonstrated that hydrogen peroxide accumulation increased in fresh-cut CWC during storage (Fig. 5). AOS production rate and activities of SOD, CAT and APX changed little while no obvious hydrogen peroxide accumulation was observed, in intact CWC during storage.

  15. Collagen scaffolds derived from fresh water fish origin and their biocompatibility.

    PubMed

    Pati, Falguni; Datta, Pallab; Adhikari, Basudam; Dhara, Santanu; Ghosh, Kuntal; Das Mohapatra, Pradeep Kumar

    2012-04-01

    Collagen, a major component of native extracellular matrix, has diverse biomedical applications. However, its application is limited due to lack of cost-effective production and risk of disease transmission from bovine sources currently utilized. This study describes fabrication and characterization of nano/micro fibrous scaffolds utilizing collagen extracted from fresh water fish origin. This is the first time collagen extracted from fresh water fish origin was studied for their biocompatibility and immunogenicity. The nano/micro fibrous collagen scaffolds were fabricated through self-assembly owing to its amphiphilic nature and were subsequently cross-linked. In vitro degradation study revealed higher stability of the cross-linked scaffolds with only ~50% reduction of mass in 30 days, while the uncross-linked one degraded completely in 4 days. Further, minimal inflammatory response was observed when collagen solution was injected in mice with or without adjuvant, without significant dilution of sera. The fish collagen scaffolds exhibited considerable cell viability and were comparable with that of bovine collagen. SEM and fluorescence microscopic analysis revealed significant proliferation rate of cells on the scaffolds and within 5 days the cells were fully confluent. These findings indicated that fish collagen scaffolds derived from fresh water origin were highly biocompatible in nature.

  16. Research of enzymatic activities of fresh juice and water infusions from dry herbs.

    PubMed

    Chudnicka, Alina; Matysik, Grazyna

    2005-06-01

    Research was done on the presence of enzymes in juice obtained from fresh plant material from Chamomilla recutita L. (Rauschel)-anthodium, Lamium album L.-flos, Calendula officinalis L.-flos, Plantaginis lanceolata L.-folium and Euphrasiae rostkoviana Hayne-herba, and in the prepared water infusion of these materials; the objective was to determine the activity of enzymes which beside biologically active substances may have an influence of the final therapeutic effect of the applied plant preparations. The research was conducted by means of the API ZYM system (bioMerieux). Higher enzymatic activities were found in fresh juices of the examined plant material than in prepared water infusions from dried plants. In both cases naphthol-AS-BI-phosphohydrolase should have highest activity. The second one in terms of activity out of 17 studied enzymes was acidic phosphatase. The highest enzymatic activity of fresh juice was found in Lamii albi flos and Calendulae officinalis flos. Water infusions showed the highest enzymatic activity in Lamii albi flos, Chamomille recutita anthodium and Plantaginis lanceolata folium. Drying the plant material resulted in decreased enzymatic activities but not in the case of naphthol-AS-BI-phosphohydrolase and acidic phosphatase which showed very low activities. The complex composition of plant materials in terms of content of biologically active substances may imply that the therapeutic effect might be directly related to the quantity and activity of plant enzymes present in preparations applied in therapeutics. PMID:15894139

  17. Fresh Water Generation from Aquifer-Pressured Carbon Storage: Annual Report FY09

    SciTech Connect

    Wolery, T; Aines, R; Hao, Y; Bourcier, W; Wolfe, T; Haussman, C

    2009-11-25

    This project is establishing the potential for using brine pressurized by Carbon Capture and Storage (CCS) operations in saline formations as the feedstock for desalination and water treatment technologies including reverse osmosis (RO) and nanofiltration (NF). The aquifer pressure resulting from the energy required to inject the carbon dioxide provides all or part of the inlet pressure for the desalination system. Residual brine is reinjected into the formation at net volume reduction, such that the volume of fresh water extracted balances the volume of CO{sub 2} injected into the formation. This process provides additional CO{sub 2} storage capacity in the aquifer, reduces operational risks (cap-rock fracturing, contamination of neighboring fresh water aquifers, and seismicity) by relieving overpressure in the formation, and provides a source of low-cost fresh water to offset costs or operational water needs. This multi-faceted project combines elements of geochemistry, reservoir engineering, and water treatment engineering. The range of saline formation waters is being identified and analyzed. Computer modeling and laboratory-scale experimentation are being used to examine mineral scaling and osmotic pressure limitations. Computer modeling is being used to evaluate processes in the storage aquifer, including the evolution of the pressure field. Water treatment costs are being evaluated by comparing the necessary process facilities to those in common use for seawater RO. There are presently limited brine composition data available for actual CCS sites by the site operators including in the U.S. the seven regional Carbon Sequestration Partnerships (CSPs). To work around this, we are building a 'catalog' of compositions representative of 'produced' waters (waters produced in the course of seeking or producing oil and gas), to which we are adding data from actual CCS sites as they become available. Produced waters comprise the most common examples of saline

  18. Global Gray Water Footprint and Water Pollution Levels Related to Anthropogenic Nitrogen Loads to Fresh Water.

    PubMed

    Mekonnen, Mesfin M; Hoekstra, Arjen Y

    2015-11-01

    This is the first global assessment of nitrogen-related water pollution in river basins with a specification of the pollution by economic sector, and by crop for the agricultural sector. At a spatial resolution of 5 by 5 arc minute, we estimate anthropogenic nitrogen (N) loads to freshwater, calculate the resultant gray water footprints (GWFs), and relate the GWFs per river basin to runoff to calculate the N-related water pollution level (WPL) per catchment. The accumulated global GWF related to anthropogenic N loads in the period 2002-2010 was 13×10(12) m3/y. China contributed about 45% to the global total. Three quarters of the GWF related to N loads came from diffuse sources (agriculture), 23% from domestic point sources and 2% from industrial point sources. Among the crops, production of cereals had the largest contribution to the N-related GWF (18%), followed by vegetables (15%) and oil crops (11%). The river basins with WPL>1 (where the N load exceeds the basin's assimilation capacity), cover about 17% of the global land area, contribute about 9% of the global river discharge, and provide residence to 48% of the global population.

  19. Global Gray Water Footprint and Water Pollution Levels Related to Anthropogenic Nitrogen Loads to Fresh Water.

    PubMed

    Mekonnen, Mesfin M; Hoekstra, Arjen Y

    2015-11-01

    This is the first global assessment of nitrogen-related water pollution in river basins with a specification of the pollution by economic sector, and by crop for the agricultural sector. At a spatial resolution of 5 by 5 arc minute, we estimate anthropogenic nitrogen (N) loads to freshwater, calculate the resultant gray water footprints (GWFs), and relate the GWFs per river basin to runoff to calculate the N-related water pollution level (WPL) per catchment. The accumulated global GWF related to anthropogenic N loads in the period 2002-2010 was 13×10(12) m3/y. China contributed about 45% to the global total. Three quarters of the GWF related to N loads came from diffuse sources (agriculture), 23% from domestic point sources and 2% from industrial point sources. Among the crops, production of cereals had the largest contribution to the N-related GWF (18%), followed by vegetables (15%) and oil crops (11%). The river basins with WPL>1 (where the N load exceeds the basin's assimilation capacity), cover about 17% of the global land area, contribute about 9% of the global river discharge, and provide residence to 48% of the global population. PMID:26440220

  20. Seasonal Variations of Chemical Compositions of Lake and Inflowing River Water from Nam Co Catchment — a Three-Year Monitoring Study

    NASA Astrophysics Data System (ADS)

    Wang, J.; Ju, J.; Daut, G.; Wang, Y.; Ma, Q.; Huang, L.; Maeusbacher, R.; Zhu, L.

    2014-12-01

    Major ionic compositions of water are of importance in a catchment, because they reflect sources of materials deposited in a lake and the controlling mechanisms. Especially Ca2+, Mg2+ and HCO3- are of interest, because they influence the process of carbonate precipitation in a lake. In this study, we present the seasonal variations of chemical compositions of lake and inflowing river water from Nam Co area. Two sites (T1 and T2) were selected for regular water sampling in Nam Co, they were located in eastern small basin (T1, water depth ~57m) and center area of the main basin (T2, water depth ~93m), respectively. Totally twenty one rivers were selected for water sampling around the lake. Water samplings were conducted in T1 and T2 stations with 10m depth interval from the top to the bottom of water column. The samples were taken almost in every month from May to December of 2011-2013. The results showed significant increase of major ions during post-mosoon period (late October) than pre-monsoon period (mid-May). In lake water, Mg2+ increased by 46.84% and 46.95% on average in two sites, while Ca2+ increased by 67.02% and 75.11% on average, respectively. HCO3- increased 27.61% and 25.02% in two sites, respectively. In river water, most ions also showed the similar trends, Mg2+ and Ca2+ increased by 40.55% and 33.20% averagely. HCO3- and SO42- increased 36.81% and 28.48%. Total dissolved solid (TDS) was used to evaluate seasonal variations of water chemistry. It is indicated both lake and river water show similar patterns. The lowest concentration of lake and river water (T2, ~1220mg/l; river average, ~95mg/l) was appeared in spring (mid-May) after the lake ice was melted. Then the TDS increased very quickly by ~10.7% and remained at a relatively stable level until mid-September, another increase of TDS occurred afterwards with the highest concentration (T2, ~1460mg/l; river average, ~145mg/l) in mid-November. During the stagnation period, the TDS of lake water

  1. Homologue and isomer distribution of dioxins observed in water samples collected from Kahokugata Lagoon and inflowing rivers, Japan.

    PubMed

    Kakimoto, Hitoshi; Oka, Hideo; Miyata, Yoshiaki; Yonezawa, Yumiko; Niikawa, Akiko; Kyudo, Hirohisa; Tang, Ning; Toriba, Akira; Kizu, Ryoichi; Hayakawa, Kazuichi

    2006-06-01

    Water samples were collected at 17 sites in Kahokugata Water Basin, a closed water basin in central Japan. We determined the concentration of dioxins of the water samples. Linear relationships between toxic equivalent (TEQ) concentrations of dioxin and concentrations of suspended solid (SS) were obtained at sites in Kahokugata Lagoon and in the rivers flowing into the lagoon. Homologue composition of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) indicated that all the water samples were still strongly influenced by chlorinated herbicides, such as chloronitrofen (CNP) and pentachlorophenol (PCP) that had been widely used in rice fields. The main isomer distributions of the PCDD homologues were not significantly different among the sampling sites, while the main isomer distributions of the PCDF homologues were considerably different among the sampling sites. At a few sampling points in the downstream part of one of the rivers, high concentrations of 1,3,6,7,8-pentachloro dibenzofuran (1,3,6,7,8-PeCDF) and its related isomers (1,3,6,8-chlorine-substituted PCDFs) were traced to a dye manufacturing plant. These non-toxic isomers are usually only minor constituents in environmental water samples and are not indicators of any known dioxin sources. The dyeing discharge was found to make a contribution only in the water samples collected near the plant and the seasonal variation of the contribution might depend on the flow rate of the river.

  2. Availability of fresh ground water, Montauk Point area, Suffolk County, Long Island, New York

    USGS Publications Warehouse

    Perlmutter, Nathaniel Matthew; DeLuca, Frank A.

    1963-01-01

    Ground water is the only source of supply at the Montauk Air Force Station n eastern Suffolk County. The water is contained in the upper 200 feet of deposits of late Pleistocene age, which are broadly divided into an upper unit of undifferentiated till and stratified drift and a lower unit of stratified drift. Fresh water in the principal aquifer, which is in the lower unit, is a lens-shaped body, which lies above salty water containing as much as 11,300 ppm of chloride. The fresh water is under artesian pressure and has a head ranging from about sea level to 3.5 feet above sea level. Pumping rates of 50 to 100 gpm cause salty water to move toward the. supply wells from below. The optimum pumping rate of most wells is about 30 gpm. New wells should be drilled as remote as possible from existing wells, and the well screens should be set as high above the zone of diffusion as the deposits permit.

  3. Hydrochemical reactions and origin of offshore relatively fresh pore water from core samples in Hong Kong

    NASA Astrophysics Data System (ADS)

    Kwong, Hiu Tung; Jiao, Jiu Jimmy

    2016-06-01

    The existence of relatively fresh pore water offshore has been well recognised over the globe but studies on the chemistry of the pore water from offshore geological formations are extremely limited. This study aims to characterize the hydrochemistry of the submarine groundwater body in Hong Kong. It looks into the major ion concentrations and the stable isotopic compositions of pore water extracted from core samples from an offshore 42.30-m vibrocore in the southwestern Hong Kong waters. A minimum Cl- level of about one-third of that in typical seawater was noted in the terrestrial sediments, suggesting the presence of offshore relatively fresh water. Unexpectedly high NH4+ levels are attributed to organic matter decomposition in the terrestrial sediments. The leaching of shells due to exposure of marine sediments at sea-level low stands raises the Mg2+ and Ca2+ concentrations. Base Exchange Indices show weak cation exchange reactions in which Na+ and K+ are released while Mg2+ and Ca2+ are adsorbed. Isotopic compositions of pore water reveal that the low-salinity water is probably the relic water sequestered in fluvial systems during relative sea-level low stands. Cores properly stored in a freezer for a long time has been used to study the pore water chemistry. For the first time, this study introduces an approach to correct the measured data by considering the possible evaporation effect during the transportation and storage of the samples. Corrections for evaporation were applied to the major ion concentrations and the stable isotopic compositions of pore water measured. It is found that the corrections determined by the Cl- mass balance approach are more reliable. The corrected measurements give more reasonable observations and hence allow sensible conclusions on the hydrochemical reactions and the origin of pore water.

  4. INFLUENCE OF FRESHWATER INFLOW AND WATER MANAGEMENT ON OYSTER-REEF RESIDENT ORGANISMS: IMPLICATIONS FOR ECOSYSTEM RESTORATION.

    EPA Science Inventory

    Two sources of seasonal programming are at work in southwest Florida estuaries: variation in temperature and variation in rainfall and water release resulting in downstream variations in salinity. Since more significant correlations were detected between salinity and metrics than...

  5. Delineating the physico-chemical, structural, and water characteristic changes during the deterioration of fresh noodles: Understanding the deterioration mechanisms of fresh noodles.

    PubMed

    Li, Man; Ma, Meng; Zhu, Ke-Xue; Guo, Xiao-Na; Zhou, Hui-Ming

    2017-02-01

    In this study, changes in fresh noodles during storage were evaluated at the physico-chemical, structural, and molecular levels. An increase in TPC and decrease in L(∗) value mostly occurred during the first 24h; the pH value significantly decreased (P<0.05) and proteins were partially depolymerized with the deterioration of fresh noodles, as evidenced by free amino acid determination and SDS-PAGE. Changes were also detected in the pasting and viscosity properties of the starch component. Moreover, the water sorption isotherm of fresh noodles decreased during storage, and the NMR transverse relaxation peak shifted right with an increased peak area between 10 and 100ms. MRI images showed that with increased storage time, the original structure was damaged and water distribution became non-uniform and migrated to the surface. TPC, pH, and L(∗) value were selected as the visualized parameters to characterize the fresh noodle deterioration, based on the correlation and factor analyses. PMID:27596433

  6. Remote sensing of chlorophyll and temperature in marine and fresh waters.

    NASA Technical Reports Server (NTRS)

    Arvesen, J. C.; Millard, J. P.; Weaver, E. C.

    1973-01-01

    An airborne differential radiometer was demonstrated to be a sensitive, real-time detector of surface chlorophyll content in water bodies. The instrument continuously measures the difference in radiance between two wavelength bands, one centered near the maximum of the blue chlorophyll a absorption region and the other at a reference wavelength outside this region. Flights were made over fresh water lakes, marine waters, and an estuary, and the results were compared with 'ground truth' measurements of chlorophyll concentration. A correlation between output signal of the differential radiometer and the chlorophyll concentration was obtained. Examples of flight data are illustrated. Simultaneous airborne measurements of chlorophyll content and water temperature revealed that variations in chlorophyll are often associated with changes in temperature. Thus, simultaneous sensing of chlorophyll and temperature provides useful information for studies of marine food production, water pollution, and physical processes such as upwelling.

  7. Phosphate adsorption characteristics at the sediment-water interface and phosphorus fractions in Nansi Lake, China, and its main inflow rivers.

    PubMed

    An, W C; Li, X M

    2009-01-01

    Phosphorus fractions and phosphate adsorption characteristics of 16 sediments from a shallow freshwater lake (Nansi Lake, China) and its inflow estuaries were investigated. In the present study, the sediment phosphorus is fractionated into exchangeable P (exch-P), Al-P, Fe-P, Ca-P, organic P (OP), inorganic P (IP) and total P (TP). The results show that the total phosphorus (TP) content in the sediments ranges from 571.67 to 1,113.55 mg kg(-1), and calcium bound phosphorus (Ca-P) is the main fraction of IP. The biologically available phosphorus (BAP) ranges from 32.02 to 229.67 mg kg(-1) in the Nansi Lake sediments. Phosphate adsorption on the sediments mainly occurs within 10 h and is completed within 48 h. The content of native adsorbed phosphorus (omega(NAP)) varies greatly from 6.05 to 194.37 mg kg(-1), showing a significant correlation with the total maximal amount of phosphorus adsorbed (TQ(max)). Adsorption efficiency (m) ranges from 574.79 to 3,220.68 l kg(-1) and zero equilibrium phosphorus concentration (C(EPC)) ranges from 0.010 to 0.157 mg l(-1). After the South-to-North Water Diversion Project, the inherent phosphorus present in sediments will be a major threat to the diverted water quality and be a predominant factor determining the trophic status of the lake even if the external load is reduced.

  8. Advanced Membrane Filtration Technology for Cost Effective Recovery of Fresh Water from Oil & Gas Produced Brine

    SciTech Connect

    David B. Burnett

    2004-09-29

    Produced water is a major waste generated at the oil and natural gas wells in the state of Texas. This water could be a possible source of new fresh water to meet the growing demands of the state after treatment and purification. Treatment of brine generated in oil fields or produced water with an ultrafiltration membranes were the subject of this thesis. The characterization of ultrafiltration membranes for oil and suspended solids removal of produced water, coupled with the reverse osmosis (RO) desalination of brine were studied on lab size membrane testing equipment and a field size testing unit to test whether a viable membrane system could be used to treat produced water. Oil and suspended solids were evaluated using turbidity and oil in water measurements taken periodically. The research considered the effect of pressure and flow rate on membrane performance of produced water treatment of three commercially available membranes for oily water. The study also analyzed the flux through the membrane and any effect it had on membrane performance. The research showed that an ultrafiltration membrane provided turbidity removal of over 99% and oil removal of 78% for the produced water samples. The results indicated that the ultrafiltration membranes would be asset as one of the first steps in purifying the water. Further results on selected RO membranes showed that salt rejection of greater than 97% could be achieved with satisfactory flux and at reasonable operating cost.

  9. Multiple Sulfur Isotopic Composition of Sulfate in the Fresh Water, Deception Island, South Shetland Islands, Antarctica

    NASA Astrophysics Data System (ADS)

    Lee, I.; Lee, J.; Seo, J.; Park, B.; Farquhar, J.; Kaufman, A. J.; Kim, K.

    2008-12-01

    Isotopic compositions of sulfur (δ33S, δ34S, δ36S) from sulfate of the fresh water in Deception island were measured to provide the information on the sources of sulfate in the surface water and to check the possibility of mass independent fractionation of sulfur in this area. Most part of the Deception Island is covered by volcanic rocks from the recent activities not exceeding 200 ka. To south and north of the Deception Island, plutonic rocks of granitic composition ranging from Mesozoic to Cenozoic are widely distributed. Because of the recent volcanic activities in Deception Island (most recent eruptions in 1970), sulfur containing aerosols produced in the stratosphere might have been added and could contribute the mass independent signature to the hydrologic system. The δ34S values of sulfate extracted from water samples at Deception Island range from 8.1 to 17.3 per mil. The Δ33S values of sulfate extracted from water samples at Deception island range from 0.000 to 0.046 per mil. Δ36S values of sulfate extracted from water samples range from -0.257 to 0.186 per mil. These waters represent the concentration from Antarctic snow and ice. In Antarctic region the natural source of sulfate dissolved in water could be originated from marine biogenic source (DMS), sea-salt, volcanic source, or other continental sources. The δ34S values of water sulfate at Deception Island well support the dominance of marine biogenic origin for the source of sulfur. Mass independent sulfur isotope anomalies are known to be produced through photochemical reactions and have been reported in Precambrian rock samples, recent atmospheric aerosols, and ice cores containing the volcanic erupted ashes piercing through stratosphere. Isotopic composition of sulfate in fresh water indicates that only mass-dependent fractionation was prevailing for sulfur isotopic system at Deception Island.

  10. Prediction in Ungauged Basins (PUB) for estimating water availability during water scarcity conditions: rainfall-runoff modelling of the ungauged diversion inflows to the Ridracoli water supply reservoir

    NASA Astrophysics Data System (ADS)

    Toth, Elena

    2013-04-01

    The Ridracoli reservoir is the main drinking water supply reservoir serving the whole Romagna region, in Northern Italy. Such water supply system has a crucial role in an area where the different characteristics of the communities to be served, their size, the mass tourism and the presence of food industries highlight strong differences in drinking water needs. Its operation allows high quality drinking water supply to a million resident customers, plus a few millions of tourists during the summer of people and it reduces the need for water pumping from underground sources, and this is particularly important since the coastal area is subject also to subsidence and saline ingression into aquifers. The system experienced water shortage conditions thrice in the last decade, in 2002, in 2007 and in autumn-winter 2011-2012, when the reservoir water storage fell below the attention and the pre-emergency thresholds, thus prompting the implementation of a set of mitigation measures, including limitations to the population's water consumption. The reservoir receives water not only from the headwater catchment, closed at the dam, but also from four diversion watersheds, linked to the reservoir through an underground water channel. Such withdrawals are currently undersized, abstracting only a part of the streamflow exceeding the established minimum flows, due to the design of the water intake structures; it is therefore crucial understanding how the reservoir water availability might be increased through a fuller exploitation of the existing diversion catchment area. Since one of the four diversion catchment is currently ungauged (at least at the fine temporal scale needed for keeping into account the minimum flow requirements downstream of the intakes), the study first presents the set up and parameterisation of a continuous rainfall-runoff model at hourly time-step for the three gauged diversion watersheds and for the headwater catchment: a regional parameterisation

  11. Surface-water and suspended-sediment inflow and outflow for Nutria Reservoir No 3, Zuni Indian Reservation, New Mexico, March 1994 to September 1995

    USGS Publications Warehouse

    Gellis, A.C.

    1998-01-01

    Surface-water and suspended-sediment inflow to and outflow from Nutria Reservoir No. 3 on the Zuni Indian Reservation, western New Mexico, were calculated. The period of study was March 3, 1994, to September 30, 1995. Total runoff into Nutria Reservoir No. 3 during the study period was 6,812 acre-feet. During the study period, 24,310 tons of suspended sediment was transported into Nutria Reservoir No. 3, and 259 tons of suspended sediment was transported out of Nutria Reservoir No. 3. Runoff during the study period, recorded at an upstream gage with 25 years of record, was 137 percent higher than that for a 19-month period similar to the study period. This may indicate that suspended-sediment loads transported into Nutria Reservoir No. 3 also were larger than average. Based on the difference between inflow and outflow of suspended sediment, 24,050 tons of suspended sediment was deposited in Nutria Reservoir No. 3. From March 1994 to May 1994 the spillway elevation of Nutria Reservoir No. 3 was raised to allow water to be diverted into an adjacent reservoir, Nutria Reservoir No. 4. This flow and sediment transported into Nutria Reservoir No. 4 were not recorded. If the elevation of the spillway had not been raised, suspended- sediment loads recorded downstream from Nutria Reservoir No. 3 would have been larger and the calculated amount of sediment deposited in Nutria Reservoir would have been smaller. Of the total suspended-sediment load entering Nutria Reservoir No. 3 during the study period, 94 percent was transported by an arroyo, Garcia Draw. Garcia Draw drains only 15 percent of the total drainage area of Nutria Reservoir No. 3 and contributed less than 5 percent of the total surface runoff to the reservoir. The average annual amount of sediment deposited in Nutria Reservoir No. 3 during the study was 15,355 tons. By using a dry-weight density of 99.4 pounds per cubic foot for the deposited sediment, the annual volume of sediment deposited in Nutria Reservoir

  12. Finite-difference model to simulate the areal flow of saltwater and fresh water separated by an interface

    USGS Publications Warehouse

    Mercer, James W.; Larson, S.P.; Faust, Charles R.

    1980-01-01

    Model documentation is presented for a two-dimensional (areal) model capable of simulating ground-water flow of salt water and fresh water separated by an interface. The partial differential equations are integrated over the thicknesses of fresh water and salt water resulting in two equations describing the flow characteristics in the areal domain. These equations are approximated using finite-difference techniques and the resulting algebraic equations are solved for the dependent variables, fresh water head and salt water head. An iterative solution method was found to be most appropriate. The program is designed to simulate time-dependent problems such as those associated with the development of coastal aquifers, and can treat water-table conditions or confined conditions with steady-state leakage of fresh water. The program will generally be most applicable to the analysis of regional aquifer problems in which the zone between salt water and fresh water can be considered a surface (sharp interface). Example problems and a listing of the computer code are included. (USGS).

  13. THE EFFECT OF FRESHWATER INFLOW ON NET ECOSYSTEM METABOLISM IN LAVACA BAY, TEXAS

    EPA Science Inventory

    Estuaries and other coastal ecosystems depend on freshwater inflow to maintain the gradients in environmental characteristics that define these transitional water bodies. Freshwater inflow (FWI) rates in many estuaries are changing due to changing land use patterns, water divers...

  14. Observed vulnerability of Filchner-Ronne Ice Shelf to wind-driven inflow of warm deep water.

    PubMed

    Darelius, E; Fer, I; Nicholls, K W

    2016-01-01

    The average rate of melting at the base of the large Filchner-Ronne Ice Shelf in the southern Weddell Sea is currently low, but projected to increase dramatically within the next century. In a model study, melt rates increase as changing ice conditions cause a redirection of a coastal current, bringing warm water of open ocean origin through the Filchner Depression and into the Filchner Ice Shelf cavity. Here we present observations from near Filchner Ice Shelf and from the Filchner Depression, which show that pulses of warm water already arrive as far south as the ice front. This southward heat transport follows the eastern flank of the Filchner Depression and is found to be directly linked to the strength of a wind-driven coastal current. Our observations emphasize the potential sensitivity of Filchner-Ronne Ice Shelf melt rates to changes in wind forcing. PMID:27481659

  15. Observed vulnerability of Filchner-Ronne Ice Shelf to wind-driven inflow of warm deep water.

    PubMed

    Darelius, E; Fer, I; Nicholls, K W

    2016-01-01

    The average rate of melting at the base of the large Filchner-Ronne Ice Shelf in the southern Weddell Sea is currently low, but projected to increase dramatically within the next century. In a model study, melt rates increase as changing ice conditions cause a redirection of a coastal current, bringing warm water of open ocean origin through the Filchner Depression and into the Filchner Ice Shelf cavity. Here we present observations from near Filchner Ice Shelf and from the Filchner Depression, which show that pulses of warm water already arrive as far south as the ice front. This southward heat transport follows the eastern flank of the Filchner Depression and is found to be directly linked to the strength of a wind-driven coastal current. Our observations emphasize the potential sensitivity of Filchner-Ronne Ice Shelf melt rates to changes in wind forcing.

  16. Observed vulnerability of Filchner-Ronne Ice Shelf to wind-driven inflow of warm deep water

    NASA Astrophysics Data System (ADS)

    Darelius, E.; Fer, I.; Nicholls, K. W.

    2016-08-01

    The average rate of melting at the base of the large Filchner-Ronne Ice Shelf in the southern Weddell Sea is currently low, but projected to increase dramatically within the next century. In a model study, melt rates increase as changing ice conditions cause a redirection of a coastal current, bringing warm water of open ocean origin through the Filchner Depression and into the Filchner Ice Shelf cavity. Here we present observations from near Filchner Ice Shelf and from the Filchner Depression, which show that pulses of warm water already arrive as far south as the ice front. This southward heat transport follows the eastern flank of the Filchner Depression and is found to be directly linked to the strength of a wind-driven coastal current. Our observations emphasize the potential sensitivity of Filchner-Ronne Ice Shelf melt rates to changes in wind forcing.

  17. Observed vulnerability of Filchner-Ronne Ice Shelf to wind-driven inflow of warm deep water

    PubMed Central

    Darelius, E.; Fer, I.; Nicholls, K. W.

    2016-01-01

    The average rate of melting at the base of the large Filchner-Ronne Ice Shelf in the southern Weddell Sea is currently low, but projected to increase dramatically within the next century. In a model study, melt rates increase as changing ice conditions cause a redirection of a coastal current, bringing warm water of open ocean origin through the Filchner Depression and into the Filchner Ice Shelf cavity. Here we present observations from near Filchner Ice Shelf and from the Filchner Depression, which show that pulses of warm water already arrive as far south as the ice front. This southward heat transport follows the eastern flank of the Filchner Depression and is found to be directly linked to the strength of a wind-driven coastal current. Our observations emphasize the potential sensitivity of Filchner-Ronne Ice Shelf melt rates to changes in wind forcing. PMID:27481659

  18. A comparison of the coupled fresh water-salt water flow and the Ghyben-Herzberg sharp interface approaches to modeling of transient behavior in coastal aquifer systems

    USGS Publications Warehouse

    Essaid, H.I.

    1986-01-01

    A quasi-three dimensional finite difference model which simulates coupled, fresh water and salt water flow, separated by a sharp interface, is used to investigate the effects of storage characteristics, transmissivity, boundary conditions and anisotropy on the transient responses of such flow systems. The magnitude and duration of the departure of aquifer response from the behavior predicted using the Ghyben-Herzberg, one-fluid approach is a function of the ease with which flow can be induced in the salt water region. In many common hydrogeologic settings short-term fresh water head responses, and transitional responses between short-term and long-term, can only be realistically reproduced by including the effects of salt water flow on the dynamics of coastal flow systems. The coupled fresh water-salt water flow modeling approach is able to reproduce the observed annual fresh water head response of the Waialae aquifer of southeastern Oahu, Hawaii. ?? 1986.

  19. Does presence of permanent fresh water affect recruitment in prairie-nesting dabbling ducks?

    USGS Publications Warehouse

    Krapu, G.L.; Pietz, P.J.; Brandt, D.A.; Cox, R.R., Jr.

    2004-01-01

    Historically, most of the Prairie Pothole Region contained limited permanent fresh water. In recent decades, permanent water bodies have been created for water-based recreation, for flood control, to increase cropland through wetland consolidation, and as part of waterfowl habitat development. We studied survival of radio-marked gadwall and mallard ducklings in wetland complexes bordering an extensive permanent water body (the McClusky Canal) in central North Dakota, and compared their survival rates (1) to those obtained on our study area before this permanent water body was created, and (2) to estimates we obtained concurrently on other study areas with little permanent water. We found that duckling survival was lower when there was substantial permanent water on the landscape, apparently because permanent water provided habitat for mink, the major predator of ducklings in our study. Permanent water allows mink populations to survive periods of drought, such as the 1988-92 drought that occurred at the beginning of our study. Environmental planners and waterfowl managers should be aware of potential risks to productivity of waterfowl and other waterbirds from development of permanent freshwater bodies in prairie pothole landscapes.

  20. Decadal predictability of extreme fresh water export events from the Arctic Ocean into the Nordic Seas and subpolar North Atlantic

    NASA Astrophysics Data System (ADS)

    Schmith, Torben; Olsen, Steffen M.; Ringgaard, Ida M.; May, Wilhelm

    2016-04-01

    Abrupt fresh water releases originating in the Arctic Ocean have been documented to affect ocean circulation and climate in the North Atlantic area. Therefore, in this study, we investigate prospects for predicting such events up to one decade ahead. This is done in a perfect model setup by a combination of analyzing a 500 year control experiment and dedicated ensemble experiment aimed at predicting selected 10 year long segments of the control experiment. The selected segments are characterized by a large positive or negative trend in the total fresh water content in the Arctic Ocean. The analysis of the components (liquid fresh water and sea ice) reveals that they develop in a near random walk manner. From this we conclude that the main mechanism is integration of fresh water in the Beaufort Gyre through Ekman pumping from the randomly varying atmosphere. Therefore, the predictions from the ensemble experiments are on average not better than a damped persistence predictions. By running two different families of ensemble predictions, one starting from the 'observed' ocean globally, and one starting from climatology in the Arctic Ocean and from the observed ocean elsewhere, we conclude that the former outperforms the latter for the first few years as regards liquid fresh water and for the first year as regards sea ice. Analysis of the model experiments in terms of the fresh water export from the Arctic Ocean into Nordic seas and the subpolar North Atlantic reveals a very modest potential for predictability.

  1. Fusion of Radarsat SAR and ETM+ imagery for identification of fresh water wetland

    NASA Astrophysics Data System (ADS)

    Ruan, Renzong; Feng, Xuezhi; She, Yuanjian

    2007-06-01

    The main aim of this paper was to identify inland fresh water wetland by using RADARSAT SAR data in combination with optical remote sensing data ETM+. The test area is a part of Hongze Lake, the fourth biggest fresh water lake in China, one of important wetlands for migratory birds in China. In this paper, two scenes of RADARSAT SAR data were acquired, one was obtained (incidence angle 39.1°) on July 9, 2003, another scene of SAR acquired on July 13, 2003(incidence angle 29.8 °). Optical remotely sensed data was Landsat ETM+ acquired on August 21, 2002. In order to explore the potential of Radarsat SAR data in the differentiation of different wetland types and wetland and upland types, two schemes were designed: one scheme was that Landsat ETM+ data and its derived data such as textural metrics were used to the classification of the study area; the other is that the Landsat ETM+ data, derived ancillary data and SAR data were used. CART algorithm was selected for the generation of decision rules, and the rules were applied to the classification of landuse/cover in the whole study area. The results showed that the combination of the SAR data and the optical remotely sensed data have achieved the highest classification accuracy (92.3% of total classification accuracy). The results also confirmed the value of classification tree in the identification of fresh water wetland. It was illustrated that radar data was a good data source for the identification of wetland.

  2. The effect of microwave power and heating time pretreatment on biogas production from fresh and dried water hyacinth (Eichhornia crassipes)

    NASA Astrophysics Data System (ADS)

    Sumardiono, Siswo; Budiyono, Mardiani, Dini Tri

    2015-12-01

    The objective of this research was to study the effect of microwave pretreatment of fresh and dried water hyacinth on biogas production. The variations of microwave power levels are 240; 400; 560 and 800 W. The variations of microwave heating time are 5; 7 and 9 min. The unpretreated fresh and dried water hyacinth are used as control. The result of research showed that almost all pretreated water hyacinth produced biogas were higher compare tounpretreated water hyacinth. The maximum of biogas production from fresh and dried water hyacinthwere obtained at 560 W for 7 min and 400 W for 7 min of microwave pretreatment. In this condition, pretreated fresh and dried water hyacinth resulted biogas production of 75,12 and 53,06 mL/g TS, respectively. The unpretreated fresh and dried water hyacinth produced biogas of 37,56 and 33,56 mL/g TS, respectively. The microwave pretreatment of water hyacinth improved biogas production. Microwave pretreatment had a positive impact on anaerobic biodegradability of water hyacinth.

  3. Power Satellites, Carbon Dioxide, Synthetic Fuel, Sequestering Carbon as Synthetic Oil and Fresh Water from Seawater

    NASA Astrophysics Data System (ADS)

    Keith Henson, H.

    2010-05-01

    A small number of people have been working for the past year on ways to reduce the cost of power from space to the point that it could entirely displace fossil fuels and even put carbon dioxide back in empty oil fields as synthetic oil. The challenging part is reducing the cost of transport to GEO by a factor of ˜200 discussed in another paper in this volume. Given low cost power, synthetic fuels, carbon sequestration, and fresh water from seawater become economical.

  4. An Examination of the Sea Surface Salinity - Fresh Water Flux Relationship Using Satellite Observations

    NASA Astrophysics Data System (ADS)

    Xie, P.; Kumar, A.; Xue, Y.; Liu, W. T.

    2014-12-01

    Relationship between the sea surface salinity (SSS) and the oceanic fresh water flux (E-P) is examined using the SSS retrievals derived from the passive microwave (PMW) observations aboard the SMOS and Aquarius satellites, the CMORPH integrated satellite precipitation estimates (P) and the evaporation data (E) produced by the NCEP Climate Forecast System (CFS) reanalysis. Preprocessing is performed to construct gridded fields of SSS, P, and E on a 1o lat/lon grid over the global oceans and at a 30-min time resolution for a 54-month period from January 2010 to June 2014. Relationships between the SSS observed at a point in time and the P, E, and P-E at the same grid box accumulated over various time periods ending at the SSS observation time are examined. As a first step, we focused our investigation on an oceanic area over the central equatorial Pacific (10oS-10oN; 180o-160oW) where SSS is not influenced by the river runoffs. Our preliminary results show clear linear relationship between the satellite-observed skin SSS and the fresh water flux over the region. The Aquarius observed instantaneous SSS presents a correlation of ~0.4 with the E-P accumulated over the 30-min period of the SSS observations. The correlation between the instantaneous SSS and the E-P drops with the accumulation period for E-P, down to 0.36 for 6-hourly accumulated E-P. The Correlation, however, bounces back and improves with the E-P accumulation period longer than 6 hours, reaching to ~0.7 for an accumulation time period of 30 days. The existence of the minimum correlation between the instantaneous SSS and the E-P accumulation over a 6-hour period suggests the involvement of air-sea interaction and oceanic processes on multiple time scales in the manner E-P influences to the SSS variations. Among the two primary components of the fresh water flux, precipitation dominates the influences on the SSS. Further analysis is under way to repeat the examination for different regions to examine the

  5. A universal method for flocculating harmful algal blooms in marine and fresh waters using modified sand.

    PubMed

    Li, Liang; Pan, Gang

    2013-05-01

    A universal environmental friendly method was developed to turn sand into effective flocculants for mitigating harmful algal blooms (HABs) in marine and freshwater systems. The isoelectric point of sand was largely increased from pH 4.5 to 10.5 after been modified by Moringa oleifera coagulant (MO) abstracted form MO seeds. However, when sand was modified by MO alone, maximum removal efficiencies of 80% and 20% for Amphidinium carterae (A.C.) and Chlorella sp. (C.S.) in seawater and 60% for Microcystis aeruginosa (M.A.) in fresh water were achieved in 30 min. The limited removal improvement was due to the form of only small flocs (20-100 μm) by surface charge modification only. Large flocs (270-800 μm) and high removal rate of 96% A.C. and C.S. cells in seawater and 90% of M.A. cells in fresh water were achieved within 30 min when the small MO-algae-sand flocs were linked and bridged by chitosan. High HAB removal rate is achievable when the sand is modified by the bicomponent mechanism of surface charge and netting-bridging modification using biodegradable modifiers such as MO and chitosan. The optimized dosage of modified sand depends on the property of algal cells and water conditions.

  6. Five new species of yeasts from fresh water and marine habitats in the Florida Everglades.

    PubMed

    Fell, Jack W; Statzell-Tallman, Adele; Scorzetti, Gloria; Gutiérrez, Marcelo H

    2011-03-01

    Yeast populations in the Shark River Slough of the Florida Everglades, USA, were examined during a 3-year period (2002-2005) at six locations ranging from fresh water marshes to marine mangroves. Seventy-four described species (33 ascomycetes and 41 basidiomycetes) and an approximately equal number of undescribed species were isolated during the course of the investigation. Serious human pathogens, such as Candida tropicalis, were not observed, which indicates that their presence in coastal waters is due to sources of pollution. Some of the observed species were widespread throughout the fresh water and marine habitats, whereas others appeared to be habitat restricted. Species occurrence ranged from prevalent to rare. Five representative unknown species were selected for formal description. The five species comprise two ascomycetes: Candida sharkiensis sp. nov. (CBS 11368(T)) and Candida rhizophoriensis sp. nov. (CBS 11402(T)) (Saccharomycetales, Metschnikowiaceae), and three basidiomycetes: Rhodotorula cladiensis sp. nov. (CBS 10878(T)) in the Sakaguchia clade (Cystobasidiomycetes), Rhodotorula evergladiensis sp. nov. (CBS 10880(T)) in the Rhodosporidium toruloides clade (Microbotryomycetes, Sporidiobolales) and Cryptococcus mangaliensis sp. nov. (CBS 10870(T)) in the Bulleromyces clade (Agaricomycotina, Tremellales). PMID:20967499

  7. Availability of fresh and slightly saline ground water in the basins of westernmost Texas

    USGS Publications Warehouse

    Gates, Joseph Spencer; Stanley, W.D.; Ackermann, H.D.

    1978-01-01

    Significant quantities of fresh ground water occur in the basin fill of the northern Hueco bolson and lower Mesilla Valley and in the Wildhorse Flat, Michigan Flat, Lobo Flat, and Ryan Flat areas of the Salt Basin; and may occur in Red Light Draw, Presidio bolson, and Green River valley. More than 20 million acre-feet of freshwater is estimated to be in storage in the basin fill of westernmost Texas. About 12 million acre-feet, or more than half, is in El Paso County in the Hueco bolson and Mesilla Valley. In addition, the basins contain about 7 million acre-feet of slightly saline water in basin fill, in Rio Grande alluvium in the Hueco bolson and lower Mesilla Valley, and in the Capitan Limestone in the northern Salt Basin. Ground-water pumping for municipal supply and industrial use in the El Paso area caused water-level declines of as much as 74 feet during 1903-73, and pumping for irrigation in the Salt Basin caused a maximum decline of 150 feet at Lobo Flat during 1949-73. Additional development of ground water in westernmost Texas will be accompanied by further declines in water levels, and will probably induce local migration of slightly saline or poorer quality water into freshwater areas. Land-surface subsidence could occur in local areas where water-level declines are large and the basin fill contains large amounts of compressible clay. (Kosco-USGS)

  8. Recovery of Fresh Water Resources from Desalination of Brine Produced During Oil and Gas Production Operations

    SciTech Connect

    David B. Burnett; Mustafa Siddiqui

    2006-12-29

    removal of hydrocarbons from produced water. The results of these experiments show that hydrocarbons from produced water can be reduced from 200 ppm to below 29 ppm level. Experiments were also done to remove the dissolved solids (salts) from the pretreated produced water using desalination membranes. Produced water with up to 45,000 ppm total dissolved solids (TDS) can be treated to agricultural water quality water standards having less than 500 ppm TDS. The Report also discusses the results of field testing of various process trains to measure performance of the desalination process. Economic analysis based on field testing, including capital and operational costs, was done to predict the water treatment costs. Cost of treating produced water containing 15,000 ppm total dissolved solids and 200 ppm hydrocarbons to obtain agricultural water quality with less than 200 ppm TDS and 2 ppm hydrocarbons range between $0.5-1.5 /bbl. The contribution of fresh water resource from produced water will contribute enormously to the sustainable development of the communities where oil and gas is produced and fresh water is a scarce resource. This water can be used for many beneficial purposes such as agriculture, horticulture, rangeland and ecological restorations, and other environmental and industrial application.

  9. Laboratory Study on Water Uptake by Freshly Emitted Peat Smoke Particles in Southeast Asia

    NASA Astrophysics Data System (ADS)

    Chen, J.; Kuwata, M.; Itoh, M.

    2015-12-01

    Tropical peatland burning activities in Southeast Asia, which can keep smouldering for a long time, have been becoming rather frequent during the last few decades. These combustions have released huge amounts of greenhouse gases and aerosol particles into the atmosphere, contributing large uncertainties to the global radiative forcing estimation. In addition, the gas and aerosol particles emitted from the peat-fire have caused environmental and human health issues. These regional and global impacts are closely tied to water uptake properties of aerosol particles, which alter their physical and chemical characteristics. However, hygroscopic property of peat burning aerosol particles has rarely been investigated. Here, we utilized a self-built Humidified Tandem Differential Mobility Analyzer (HTDMA) to measure diameter growth factors of fresh peat burning particles, which were generated during laboratory peat combustion experiments under controlled conditions. Particle number size distribution and chemical composition were also measured using a Scanning Mobility Particle Sizer (SMPS) and the Time of Flight - Aerosol Chemical Speciation Monitor (ToF-ACSM). Number size distribution demonstrated a bimodal pattern, with the mode diameters in the size ranges of 50-80 nm and 300-500 nm, respectively. The corresponding normalized volume size distribution was unimodal distributed with mode diameter at around 400-600nm. Water uptake of freshly emitted peat smoke aerosol particles was less hygroscopic, probably because fresh peat burning aerosol particles were predominantly composed of organic compounds and sulfates were negligible. The obtained information can be further applied into the studies on the influence of peat burning aerosol particles on regional and global climate.

  10. Decarb/Desal: Separation of Carbon Dioxide from Flue Gas with Simultaneous Fresh Water Production

    SciTech Connect

    Aines, R; Bourcier, W

    2009-10-21

    If fossil fuels continue to be a major part of the world's energy supply, effective means must be developed to deal with the carbon emissions. Geologic sequestration of supercritical CO{sub 2} is expected to play a major role in mitigating this problem. Separating carbon dioxide from other gases is the most costly aspect of schemes for geologic sequestration. That cost is driven by the complexity and energy intensity of current chemical-stripping methods for separating carbon dioxide. Our experience in water treatment technology indicated that an entirely new approach could be developed, taking advantage of water's propensity to separate gases that ionize in water (like CO{sub 2}) from those that do not (like N{sub 2}). Even though water-based systems might not have the extreme selectivity of chemicals like substituted amines used in industrial systems today, they have the potential to tolerate NO{sub x}, SO{sub x}, and particulates while also producing clean drinking water as a valuable byproduct. Lower capital cost, broader range of applicability, environmental friendliness, and revenue from a second product stream give this approach the potential to significantly expand the worldwide application of carbon separation for geologic sequestration. Here we report results for separation of CO{sub 2} from flue gas by two methods that simultaneously separate carbon dioxide and fresh water: ionic pumping of carbonate ions dissolved in water, and thermal distillation. The ion pumping method dramatically increases dissolved carbonate ion in solution and hence the overlying vapor pressure of CO{sub 2} gas, allowing its removal as a pure gas. We have used two common water treatment methods to drive the ion pumping approach, reverse osmosis and electrodialysis to produce pure CO{sub 2}. This novel approach to increasing the concentration of the extracted gas permits new approaches to treating flue gas, because the slightly basic water used as the extraction medium is

  11. Radial inflow turbine study

    NASA Astrophysics Data System (ADS)

    Hamid, S.; Elder, R. L.

    1992-03-01

    The radial inflow turbine is a primary component used both in small gas turbines and turbochargers. Better understanding of the flow processes occurring within the small passages of the machine could well result in the improved design of units. As most of the detailed aerodynamics is still ill-defined, a joint research project with the objective of improving our understanding has been instigated by Cranfield, the US Army and Turbomach (San Diego). This document gives the seventh report on the project and describes progress and measurements taken.

  12. Influence of water allocation and freshwater inflow on oyster production: a hydrodynamic-oyster population model for Galveston Bay, Texas, USA.

    PubMed

    Powell, Eric N; Klinck, John M; Hofmann, Eileen E; McManus, Margaret A

    2003-01-01

    A hydrodynamic-oyster population model was developed to assess the effect of changes in freshwater inflow on oyster populations in Galveston Bay, Texas, USA. The population model includes the effects of environmental conditions, predators, and the oyster parasite, Perkinsus marinus, on oyster populations. The hydrodynamic model includes the effects of wind stress, river runoff, tides, and oceanic exchange on the circulation of the bay. Simulations were run for low, mean, and high freshwater inflow conditions under the present (1993) hydrology and predicted hydrologies for 2024 and 2049 that include both changes in total freshwater inflow and diversions of freshwater from one primary drainage basin to another. Freshwater diversion to supply the Houston metropolitan area is predicted to negatively impact oyster production in Galveston Bay. Fecundity and larval survivorship both decline. Mortality from Perkinsus marinus increases, but to a lesser extent. A larger negative impact in 2049 relative to 2024 originates from the larger drop in fecundity under that hydrology. Changes in recruitment and mortality, resulting in lowered oyster abundance, occur because the bay volume available for mixing freshwater input from the San Jacinto and Buffalo Bayou drainage basins that drain metropolitan Houston is small in comparison to the volume of Trinity Bay that presently receives the bulk of the bay's freshwater inflow. A smaller volume for mixing results in salinities that decline more rapidly and to a greater extent under conditions of high freshwater discharge.Thus, the decline in oyster abundance results from a disequilibrium between geography and salinity brought about by freshwater diversion. Although the bay hydrology shifts, available hard substrate does not. The simulations stress the fact that it is not just the well-appreciated reduction in freshwater inflow that can result in decreased oyster production. Changing the location of freshwater inflow can also

  13. Circulation and transformation of Atlantic water in the Eurasian Basin and the contribution of the Fram Strait inflow branch to the Arctic Ocean heat budget

    NASA Astrophysics Data System (ADS)

    Rudels, Bert; Korhonen, Meri; Schauer, Ursula; Pisarev, Sergey; Rabe, Benjamin; Wisotzki, Andreas

    2015-03-01

    The inflows of Atlantic water from the Nordic Seas to the Arctic Ocean through Fram Strait and over the Barents Sea are examined and their pathways and transformations in the Eurasian Basin are described based primarily on hydrographic observations from two cruises with RV Polarstern in 2007 and 2011. The contrast between the high salinity Atlantic water core in the Nansen Basin and the lower Atlantic water salinity in the Amundsen Basin, combined with a salinity minimum below the Atlantic layer, suggest that the Fram Strait branch mainly remains in the Nansen Basin, while the Barents Sea branch continues along the continental slope, enters the Amundsen Basin and provides most of the Atlantic water in the Makarov and Canada basins. To examine the consequences of such a circulation pattern recently published estimates of the in- and outflows of volume and liquid freshwater through the Barents Sea, Bering Strait and the Canadian Arctic Archipelago as well as river runoff, net precipitation and ice export are reviewed and added together. To achieve volume and freshwater balances net outflows through Fram Strait of 2.3 Sv and 100 mSv respectively are required. This is reasonably close to the recently reported Fram Strait transport estimates. The net outflows are separated into two parts, upper layer transports, less dense than the entering Atlantic water, and lower layer transports, as dense as or denser than the Atlantic water. The largest net volume outflow occurs in the lower layer, 1.65 Sv, while the liquid freshwater is almost exclusively exported in the 0.64 Sv net outflow in upper layer, leading to unrealistically low salinities in the upper layer compared with observations. Atlantic water is north of Svalbard transformed into less saline surface water through melting of sea ice, which can supply the necessary higher salinity (halocline) water to the upper layer. 1.23 Sv of halocline water of salinity 34.2 must be added to obtain a more realistic salinity of 33

  14. Reduction of organic trace compounds and fresh water consumption by recovery of advanced oxidation processes treated industrial wastewater.

    PubMed

    Bierbaum, S; Öller, H-J; Kersten, A; Klemenčič, A Krivograd

    2014-01-01

    Ozone (O(3)) has been used successfully in advanced wastewater treatment in paper mills, other sectors and municipalities. To solve the water problems of regions lacking fresh water, wastewater treated by advanced oxidation processes (AOPs) can substitute fresh water in highly water-consuming industries. Results of this study have shown that paper strength properties are not impaired and whiteness is slightly impaired only when reusing paper mill wastewater. Furthermore, organic trace compounds are becoming an issue in the German paper industry. The results of this study have shown that AOPs are capable of improving wastewater quality by reducing organic load, colour and organic trace compounds.

  15. Analytical approach for determining the mean water level profile in an estuary with substantial fresh water discharge

    NASA Astrophysics Data System (ADS)

    Cai, Huayang; Savenije, Hubert H. G.; Jiang, Chenjuan; Zhao, Lili; Yang, Qingshu

    2016-03-01

    The mean water level in estuaries rises in the landward direction due to a combination of the density gradient, the tidal asymmetry, and the backwater effect. This phenomenon is more prominent under an increase of the fresh water discharge, which strongly intensifies both the tidal asymmetry and the backwater effect. However, the interactions between tide and river flow and their individual contributions to the rise of the mean water level along the estuary are not yet completely understood. In this study, we adopt an analytical approach to describe the tidal wave propagation under the influence of substantial fresh water discharge, where the analytical solutions are obtained by solving a set of four implicit equations for the tidal damping, the velocity amplitude, the wave celerity, and the phase lag. The analytical model is used to quantify the contributions made by tide, river, and tide-river interaction to the water level slope along the estuary, which sheds new light on the generation of backwater due to tide-river interaction. Subsequently, the method is applied to the Yangtze estuary under a wide range of river discharge conditions where the influence of both tidal amplitude and fresh water discharge on the longitudinal variation of the mean tidal water level is explored. Analytical model results show that in the tide-dominated region the mean water level is mainly controlled by the tide-river interaction, while it is primarily determined by the river flow in the river-dominated region, which is in agreement with previous studies. Interestingly, we demonstrate that the effect of the tide alone is most important in the transitional zone, where the ratio of velocity amplitude to river flow velocity approaches unity. This has to do with the fact that the contribution of tidal flow, river flow, and tide-river interaction to the residual water level slope are all proportional to the square of the velocity scale. Finally, we show that, in combination with extreme

  16. The behavior of heavy metals in tidal flat sediments during fresh water leaching.

    PubMed

    Li, QuSheng; Liu, YaNan; Du, YeFeng; Cui, ZhiHong; Shi, Lei; Wang, LiLi; Li, HongJie

    2011-02-01

    Many of the coastal tidal flats in China that were polluted with heavy metals are now being reclaimed for arable land. The safety of these soils for agriculture is of great concern. The present study investigated the sediment chemical properties, concentrations, and speciation of heavy metals at different levels of desalination during a controlled leaching experiment. After leaching with fresh water, the average reductions in the heavy metal species examined in 0-65 cm depth sediment were 32.1% for Pb, 26.2% for Cd, 14.0% for Zn, 13.8% for Cu, and 11.0% for Cr, while the Ni concentration in sediment did not change significantly. The amounts of Cd, Pb, Cr, Cu, and Zn bound to the reducible fraction, the amounts of Cd, Pb, and Zn bound to the exchangeable fraction, the amounts of Pb, Cr, Cu, and Zn associated with the carbonate fraction, and the Cu associated with the oxidizable fraction all decreased significantly. Complexation with salt anions, ion exchange between the cations and the metal ions, removal of SO4(2-), dissolution of carbonate, and the redox potential variations all contributed to the decreases in Pb, Cd, Zn, Cu, and Cr. These results suggest that leaching with fresh water can also remove a fraction of the heavy metal contamination when it diminishes sediment salinity. PMID:21131022

  17. Control of spoiler Pseudomonas spp. on fresh cut vegetables by neutral electrolyzed water.

    PubMed

    Pinto, Loris; Ippolito, Antonio; Baruzzi, Federico

    2015-09-01

    In the present study, we evaluated the antimicrobial activity of neutral electrolyzed water (NEW) against 14 strains of spoilage Pseudomonas of fresh cut vegetables under cold storage. The NEW, produced from solutions of potassium and sodium chloride, and sodium bicarbonate developed up to 4000 mg/L of free chlorine, depending on the salt and relative concentration used. The antimicrobial effect of the NEW was evaluated against different bacterial strains at 10(5) cells/ml, with different combinations of free chlorine concentration/contact time; all concentrations above 100 mg/L, regardless of the salt used, were found to be bactericidal already after 2 min. When catalogna chicory and lettuce leaves were dipped for 5 min in diluted NEW, microbial loads of mesophilic bacteria and Enterobacteriaceae were reduced on average of 1.7 log cfu/g. In addition, when lettuce leaves were dipped in a cellular suspension of the spoiler Pseudomonas chicorii I3C strain, diluted NEW was able to reduce Pseudomonas population of about 1.0 log cfu/g. Thanks to its high antimicrobial activity against spoilage microorganisms, and low cost of operation, the application of cycles of electrolysis to the washing water looks as an effective tool in controlling fresh cut vegetable microbial spoilage contamination occurring during washing steps.

  18. The behavior of heavy metals in tidal flat sediments during fresh water leaching.

    PubMed

    Li, QuSheng; Liu, YaNan; Du, YeFeng; Cui, ZhiHong; Shi, Lei; Wang, LiLi; Li, HongJie

    2011-02-01

    Many of the coastal tidal flats in China that were polluted with heavy metals are now being reclaimed for arable land. The safety of these soils for agriculture is of great concern. The present study investigated the sediment chemical properties, concentrations, and speciation of heavy metals at different levels of desalination during a controlled leaching experiment. After leaching with fresh water, the average reductions in the heavy metal species examined in 0-65 cm depth sediment were 32.1% for Pb, 26.2% for Cd, 14.0% for Zn, 13.8% for Cu, and 11.0% for Cr, while the Ni concentration in sediment did not change significantly. The amounts of Cd, Pb, Cr, Cu, and Zn bound to the reducible fraction, the amounts of Cd, Pb, and Zn bound to the exchangeable fraction, the amounts of Pb, Cr, Cu, and Zn associated with the carbonate fraction, and the Cu associated with the oxidizable fraction all decreased significantly. Complexation with salt anions, ion exchange between the cations and the metal ions, removal of SO4(2-), dissolution of carbonate, and the redox potential variations all contributed to the decreases in Pb, Cd, Zn, Cu, and Cr. These results suggest that leaching with fresh water can also remove a fraction of the heavy metal contamination when it diminishes sediment salinity.

  19. Control of spoiler Pseudomonas spp. on fresh cut vegetables by neutral electrolyzed water.

    PubMed

    Pinto, Loris; Ippolito, Antonio; Baruzzi, Federico

    2015-09-01

    In the present study, we evaluated the antimicrobial activity of neutral electrolyzed water (NEW) against 14 strains of spoilage Pseudomonas of fresh cut vegetables under cold storage. The NEW, produced from solutions of potassium and sodium chloride, and sodium bicarbonate developed up to 4000 mg/L of free chlorine, depending on the salt and relative concentration used. The antimicrobial effect of the NEW was evaluated against different bacterial strains at 10(5) cells/ml, with different combinations of free chlorine concentration/contact time; all concentrations above 100 mg/L, regardless of the salt used, were found to be bactericidal already after 2 min. When catalogna chicory and lettuce leaves were dipped for 5 min in diluted NEW, microbial loads of mesophilic bacteria and Enterobacteriaceae were reduced on average of 1.7 log cfu/g. In addition, when lettuce leaves were dipped in a cellular suspension of the spoiler Pseudomonas chicorii I3C strain, diluted NEW was able to reduce Pseudomonas population of about 1.0 log cfu/g. Thanks to its high antimicrobial activity against spoilage microorganisms, and low cost of operation, the application of cycles of electrolysis to the washing water looks as an effective tool in controlling fresh cut vegetable microbial spoilage contamination occurring during washing steps. PMID:25998822

  20. Effect of electrolyzed oxidizing water treatment on the reduction of nitrite levels in fresh spinach during storage.

    PubMed

    Hao, Jianxiong; Li, Huiying; Wan, Yangfang; Liu, Haijie

    2015-03-01

    Leafy vegetables are the major source of nitrite intake in the human diet, and technological processing to control nitrite levels in harvested vegetables is necessary. In the current work, the effect of electrolyzed oxidizing water (EOW) on the nitrite and nitrate levels in fresh spinach during storage was studied. EOW treatment, including slightly acidic electrolyzed water and acidic electrolyzed water, was found to effectively reduce nitrite levels in fresh spinach during storage; levels in the late period were 30 to 40% lower than that of the control. However, the nitrate levels in fresh spinach during storage were not influenced by EOW treatment. The reduction of nitrite levels in EOW-treated fresh spinach during storage can be attributed to the inactivation of nitrate reductase directly and to the reduction of bacterial populations. Our results suggest that treatment with slightly acidic electrolyzed water may be a better choice to control nitrite levels in fresh vegetables during storage. This study provided a useful method to reduce nitrite levels in fresh spinach.

  1. DNA adducts in marine mussel and fresh water fishes living in polluted and unpolluted environments

    SciTech Connect

    Kurelec, B.; Checko, M.; Krca, S.; Garg, A.; Gupta, R.C. Baylor College of Medicine, Houston, TX )

    1988-09-01

    {sup 32}P-postlabeling analysis of DNA adducts in the digestive gland of marine mussel Mytilus galloprovincialis from polluted and unpolluted sites near Rovinj, Northern Adriatic, revealed that majority of adducts are caused by natural environmental factors rather than by man-made chemicals. The only pollutant-specific adducts were observed in a mussel exposed to seawater experimentally polluted with aminofluorene, and in a population of mussel living at a site heavily polluted with a waste waters of an oil refinery. Fresh water fish species Leuciscus cephalus, Barbus barbus, Abramis brama and Rutilus pigus virgo living in a polluted Sava River, Yugoslavia, or in its unpolluted tributary Korana River, have induced in their livers qualitatively identical and quantitatively similar DNA adducts. These DNA adducts had a species-specific patterns and their appearance was seasonally-dependent.

  2. Membrane filter procedure for enumeration of Aeromonas hydrophila in fresh waters.

    PubMed

    Rippey, S R; Cabelli, V J

    1979-07-01

    A membrane filter method (mA) for the enumeration of Aeromonas hydrophila in natural water samples was developed. The complex, primary medium employs trehalose as a fermentable carbohydrate and ampicillin and ethanol as selective inhibitors. After 20 h of incubation at 37 degrees C, an in situ mannitol fermentation test followed by an in situ oxidase test is used to further differentiate A. hydrophila from other aquatic and terrestrial microorganisms present in freshwaters. The primary medium decreases background microbial growth by about two orders of magnitude. The recoveries on mA medium from suspensions of A. hydrophila prepared from pure cultures and held for 24 h at 15 degrees C exceeded 95% of the recoveries on brain-heart infusion agar spread plates. The confirmation rate for colonies designated A. hydrophila was 98%, whereas 11% of the presumptively negative colonies were, in fact, A. hydrophila. Recoveries of A. hydrophila from fresh, surface water samples exceeded recoveries by the other methods examined.

  3. Assessing Pesticide Contamination to Fresh Water in Some Agricultural Sites, Close to Oaxaca City, Mexico

    NASA Astrophysics Data System (ADS)

    Tomas, G.

    2002-12-01

    This study presents the results of a survey on pesticides in fresh water in shallow aquifers, rivers and dams in Zaachila, Tlacolula and Etla and agricultural valleys close to Oaxaca City, SW of Mexico. In the study zones, there are generalized uses of pesticides and the impact on the water resources by inadequate use of agricultural activities. Water is used for irrigation and drinking. Surveying criteria was to sample the aquifer (production wells), its water table (dig wells) and a regional water collector (Plan Benito Juarez Yuayapan dam). A total of 14 samples were analyzed for the identification and quantification of organochlorine and organophosphorous pesticides. Method was 508-EPA. Gas chromatographer was a 5890 series II Hewlett Packard, calibrated with several patterns. Results: 10 samples are contaminated with some pesticide of the used patterns; Dieldrin, Chlordano, Malathion, Mirex were not found; Traces of organophosphorus compounds were found in 8 samples, mainly Merphos, Parathion Ethylic and Disulfoton ; There was detected traces of world-forbidden insecticides as Metoxychlor, Parathion Ethylic and Disulfoton; and In one sample (Cuilapam well #1) DDT exceeds, the Mexican maximum limit for potable water (1 mg/l),

  4. Total alkalinity versus buffer value (capacity) as a sensitivity indicator for fresh waters receiving acid rain

    SciTech Connect

    Faust, S.D.

    1983-09-01

    The frequently stated idea that total alkalinity is a measure of the buffer capacity of a natural water is refuted. Total alkalinity is a measure of the acid neutralizing capacity, equivalents/liter, of a water. In natural waters, the carbonate system provides most of this neutralizing capacity. In as much as the pH values of natural fresh waters lie below 8.3, the total alkalinity is, for all intents and purposes, the total bicarbonate content. Any contributions of carbonate and hydroxide to total alkalinity are nil. The buffer capacity or buffer value is the relation between the increment of a strong base, or strong acid, that causes a one unit change in the pH value. The values of total alkalinity and pH, considered individually cannot give an accurate assessment of the impact of acid deposition on a natural water. Rather it is necessary to combine the pH and alkalinity values into the beta concept in order to assess accurately and to calculate the capacity of a natural water to resist the impact of acid deposition. An analytical determination of total alkalinity is given with an application of the beta value. 17 references, 2 figures, 4 tables.

  5. Influence of fresh water, nutrients and DOC in two submarine-groundwater-fed estuaries on the west of Ireland.

    PubMed

    Smith, Aisling M; Cave, Rachel R

    2012-11-01

    Coastal fresh water sources, which discharge to the sea are expected to be directly influenced by climate change (e.g. increased frequency of extreme weather events). Sea-level rise and changes in rainfall patterns, changes in demand for drinking water and contamination caused by population and land use change, will also have an impact. Coastal waters with submarine groundwater discharge are of particular interest as this fresh water source is very poorly quantified. Two adjacent bays which host shellfish aquaculture sites along the coast of Co. Galway in the west of Ireland have been studied to establish the influence of fresh water inputs on nutrients and dissolved organic carbon (DOC) in each bay. Neither bay has riverine input and both are underlain by the karst limestone of the Burren and are susceptible to submarine groundwater discharge. Water and suspended matter samples were collected half hourly over 13 h tidal cycles over several seasons. Water samples were analysed for nutrients and DOC, while suspended matter was analysed for organic/inorganic content. Temperature and salinity measurements were recorded during each tidal station by SBE 37 MicroCAT conductivity/temperature sensors. Long-term mooring data were used to track freshwater input for Kinvara and Aughinish Bays and compare it with rainfall data. Results show that Kinvara Bay is much more heavily influenced by fresh water input than Aughinish Bay, and this is a strong source of fixed nitrogen to Kinvara Bay. Only during flood events is there a significant input of inorganic nitrogen from fresh water to Aughinish Bay, such as in late November 2009. Fresh water input does not appear to be a significant source of dissolved inorganic phosphate (DIP) to either bay, but is a source of DOC to both bays. C:N ratios of DOC/DON show a clear distinction between marine and terrestrially derived dissolved organic material.

  6. Numerical modelling and hydrochemical characterisation of a fresh-water lens in the Belgian coastal plain

    NASA Astrophysics Data System (ADS)

    Vandenbohede, A.; Lebbe, L.

    2002-05-01

    The distribution of fresh and salt water in coastal aquifers is influenced by many processes. The influence of aquifer heterogeneity and human interference such as land reclamation is illustrated in the Belgian coastal plain where, around A.D. 1200, the reclamation of a tidally influenced environment was completed. The aquifer, which was filled with salt water, was thereafter freshened. The areal distribution of peat, clay, silt and sand influences the general flow and distribution of fresh and salt water along with the drainage pattern and results in the development of fresh-water lenses. The water quality in and around the fresh-water lenses below an inverted tidal channel ridge is surveyed. The hydrochemical evolution of the fresh water lens is reconstructed, pointing to cation exchange, solution of calcite and the oxidation of organic material as the major chemical reactions. The formation and evolution of the fresh water lens is modelled using a two-dimensional density-dependent solute transport model and the sensitivity of drainage and conductivities are studied. Drainage level mainly influences the depth of the fresh-water lens, whereas the time of formation is mainly influenced by conductivity. Résumé. La répartition de l'eau douce et de l'eau salée dans les aquifères littoraux est influencée par de nombreux mécanismes. L'influence de l'hétérogénéité de l'aquifère et des interférences anthropiques telles que la mise en valeur des terres est illustrée par la plaine côtière belge où, depuis l'an 1200, on a mis en valeur un environnement soumis aux marées. L'aquifère, qui contenait de l'eau salée, contient maintenant de l'eau douce. La distribution spatiale de tourbe, d'argile, de silt et de sable joue un rôle dans l'écoulement général et dans la répartition de l'eau douce et de l'eau salée le long du réseau de drainage et produit des lentilles d'eau douce. La qualité de l'eau dans et autour des lentilles d'eau douce sous une lev

  7. Effects of water extract of propolis on fresh shibuta (Barbus grypus) fillets during chilled storage.

    PubMed

    Duman, Muhsine; Özpolat, Emine

    2015-12-15

    The present study examined the effects of water extract of propolis on the chemical, microbiological and sensory quality in vacuum-packed fresh shibuta (Barbus grypus) fillets during storage at 2°C. Treatments in the study included the following: control (P0) without extract of propolis, 0.1 (P1), 0.3 (P3) and 0.5 (P5) % (v/w) the water extract of propolis, respectively. After 24 days of storage, the total volatile basic nitrogen (TVB-N) values were 57.76, 44.66, 42.23 and 36.5mg/100g, and total viable counts (TVC) were 8.9, 8.3, 7.96 and 6.95logcfu/g, for water extract of propolis additions of 0.1 (P1), 0.3 (P3), 0.5 (P5) and 0 (control; P0) % (v/w), respectively. The highest acceptable TVB-N value was adopted as 30 mg/100g, corresponding to shelf lives of 9, 15, 18 and 21 days for P0, P1, P3 and P5, respectively. Addition of 0.1% water extract of propolis extended the product's shelf-life by approximately 6 days, whereas the 0.5% water extract of propolis resulted in a significant shelf-life extension of the shibuta fillets, i.e. by approximately 12 days, according to sensory data, as compared to the control sample.

  8. Reductions of Cd in a Cd-contaminated fish by long-term exposure to EDTA or fresh-water

    SciTech Connect

    Muramoto, S.

    1982-01-01

    The variations in Cd levels with the passage of time in the viscera and gills of carp (Cyprinus carpio L.) after exposure to 0.01 and 0.05 ppm Cd containing water for 3 months were determined. After 3 months, the fish were treated with fresh-water. The fresh-water treatment produced slow recovery in the viscera, but the Cd concentration in the gills remained approximately the same. From the results of the study, it was postulated that the recovery of fish contaminated with Cd and other heavy metals would seem possible due to loose bindings of the metals to protein of the fish. (JMT)

  9. The deglaciation over Laurentian Fan: History of diatoms, IRD, ice and fresh water

    NASA Astrophysics Data System (ADS)

    Gil, Isabelle M.; Keigwin, Lloyd D.; Abrantes, Fatima

    2015-12-01

    A high-resolution diatom census coupled with other proxy data from Laurentian Fan (LF) provides a detailed description of the last deglaciation, bringing new insight to that period by revealing directly the timing of sea-ice formation and melting. Cold events Heinrich Event 1 (H1) and the Younger Dryas (YD) were multiphase events. H1 (˜16.8-15.7 cal kyr BP) was defined by a two-pulse release of icebergs promoting sea-ice formation. Melting of sea-ice after H1 corresponds to a cold and fresh anomaly that may have kept the Bølling colder than the Allerød. At ˜13.6 cal kyr BP, a cooling trend culminated with sea-ice formation, marking the YD onset (˜12.8 cal kyr BP). The decrease in sea-ice (˜12.2 cal kyr BP) led to a YD second phase characterized by very cold winters. However, the contribution of warm water diatoms tends to increase at the same time and the YD gradual end (˜11.6 cal kyr BP) contrasts with its abrupt end in Greenland ice cores. The YD cannot be regarded as an event triggered by a fresh water input through the Laurentian Channel since only one weak brief input nearly 1000 yrs after its onset is recorded. Very cold and cool conditions without ice mark the following Preboreal. A northward heat flux between 10.8 and 10.2 cal kyr BP was interrupted by the increased influence of coastal waters likely fed by inland melting. There was no further development of sea-ice or ice-drift then.

  10. Salt water and its relation to fresh ground water in Harris County, Texas

    USGS Publications Warehouse

    Winslow, Allen G.; Doyel, William Watson; Wood, L.A.

    1957-01-01

    Other less probable potential sources of salt-water contamination which are discussed include upward movement of salt water from below, vertical movement around salt domes or along faults, downward seepage from surface sources, and contamination through leaking wells.

  11. Acid precipitation: effects on fresh-water ecosystems. January 1978-September 1988 (Citations from the Life Sciences Collection data base). Report for January 1978-September 1988

    SciTech Connect

    Not Available

    1988-10-01

    This bibliography contains citations concerning the effects of acidification of fresh-water ecosystems. Algae and diatom distribution, survival, and reproduction rates of specific fish species under acid-lake conditions, and tolerance to stress caused by acidic conditions in fresh water ecosystems are studied. Effects of water ph on trace metal toxicity to fresh water organisms is briefly considered. Control and reduction of acidification is excluded from this bibliography. (Contains 290 citations fully indexed and including a title list.)

  12. Radial Inflow Turboexpander Redesign

    SciTech Connect

    William G. Price

    2001-09-24

    Steamboat Envirosystems, LLC (SELC) was awarded a grant in accordance with the DOE Enhanced Geothermal Systems Project Development. Atlas-Copco Rotoflow (ACR), a radial expansion turbine manufacturer, was responsible for the manufacturing of the turbine and the creation of the new computer program. SB Geo, Inc. (SBG), the facility operator, monitored and assisted ACR's activities as well as provided installation and startup assistance. The primary scope of the project is the redesign of an axial flow turbine to a radial inflow turboexpander to provide increased efficiency and reliability at an existing facility. In addition to the increased efficiency and reliability, the redesign includes an improved reduction gear design, and improved shaft seal design, and upgraded control system and a greater flexibility of application

  13. Water from land - fresh water outflow from glaciated and non-glaciated catchments into the Hornsund fjord, Svalbard

    NASA Astrophysics Data System (ADS)

    Nawrot, Adam; Wawrzyniak, Tomasz; Walczowski, Waldemar; Osuch, Marzena

    2016-04-01

    Freshwater processes in South Spitsbergen catchments are facing climate related alterations and issues, such as prolongation of the ablation seasons, water level changes and droughts. Snow accumulation and duration of snow cover in high latitude areas largely determine hydrological and periglacial processes, influencing flora, fauna and their ecology. Hydrological data from this part of the Arctic so far were sparse and major gaps remained in our understanding of freshwater distribution, regime, status and threats. From 2013 to 2015 as part of multidisciplinary and complex investigations within the framework of "AWAKE2 - Arctic Climate System Study of Ocean, Sea Ice and Glaciers Interactions in Svalbard Area" project, field measurements were conducted around Hornsund, the southernmost fjord of Spitsbergen. This was the first study of the fresh water and snow cover in such scale in this area and included spatial distribution of snow, together with water balance measurements in non-glaciated and glaciated catchments. During the fieldwork in Hornsund Fjord area, snow thickness and snow density have been measured in 350 and 50 points, respectively. Precipitation was measured in 6 points. Runoff was measured on 7 rivers in different glaciated (Ariedalen, Sofiedalen, Lorchbreen, Bautabreen, Gashamna) and non-glaciated (Fuglebekken, Lisbetdalen) catchments. Meteorological observations were conducted at the Hornsund Polish Polar Station and in the in the surroundings of Hornsund fjord. The results of this investigation show response of the freshwater hydrological processes to observed seasonal climatic variations in this area. Approximated water balance and known volume of fresh water outflow to the sea are the key components of understanding Arctic fjord ecosystem mechanisms. This is the first comprehensive investigation of the water balance in this region. Project AWAKE2 is funded by Norway Grants.

  14. Biological differences between brackish and fresh water-derived Aedes aegypti from two locations in the Jaffna peninsula of Sri Lanka and the implications for arboviral disease transmission.

    PubMed

    Ramasamy, Ranjan; Jude, Pavilupillai J; Veluppillai, Thabothiny; Eswaramohan, Thampoe; Surendran, Sinnathamby N

    2014-01-01

    The mainly fresh water arboviral vector Aedes aegypti L. (Diptera: Culicidae) can also undergo pre-imaginal development in brackish water of up to 15 ppt (parts per thousand) salt in coastal areas. We investigated differences in salinity tolerance, egg laying preference, egg hatching and larval development times and resistance to common insecticides in Ae. aegypti collected from brackish and fresh water habitats in Jaffna, Sri Lanka. Brackish water-derived Ae. aegypti were more tolerant of salinity than fresh water-derived Ae. aegypti and this difference was only partly reduced after their transfer to fresh water for up to five generations. Brackish water-derived Ae. aegypti did not significantly discriminate between 10 ppt salt brackish water and fresh water for oviposition, while fresh water-derived Ae. aegypti preferred fresh water. The hatching of eggs from both brackish and fresh water-derived Ae. aegypti was less efficient and the time taken for larvae to develop into pupae was prolonged in 10 ppt salt brackish water. Ae. aegypti isolated from coastal brackish water were less resistant to the organophosphate insecticide malathion than inland fresh water Ae. aegypti. Brackish and fresh water-derived Ae. aegypti however were able to mate and produce viable offspring in the laboratory. The results suggest that development in brackish water is characterised by pertinent biological changes, and that there is restricted genetic exchange between coastal brackish and inland fresh water Ae. aegypti isolates from sites 5 km apart. The findings highlight the need for monitoring Ae. aegypti developing in coastal brackish waters and extending vector control measures to their habitats.

  15. Biological differences between brackish and fresh water-derived Aedes aegypti from two locations in the Jaffna peninsula of Sri Lanka and the implications for arboviral disease transmission.

    PubMed

    Ramasamy, Ranjan; Jude, Pavilupillai J; Veluppillai, Thabothiny; Eswaramohan, Thampoe; Surendran, Sinnathamby N

    2014-01-01

    The mainly fresh water arboviral vector Aedes aegypti L. (Diptera: Culicidae) can also undergo pre-imaginal development in brackish water of up to 15 ppt (parts per thousand) salt in coastal areas. We investigated differences in salinity tolerance, egg laying preference, egg hatching and larval development times and resistance to common insecticides in Ae. aegypti collected from brackish and fresh water habitats in Jaffna, Sri Lanka. Brackish water-derived Ae. aegypti were more tolerant of salinity than fresh water-derived Ae. aegypti and this difference was only partly reduced after their transfer to fresh water for up to five generations. Brackish water-derived Ae. aegypti did not significantly discriminate between 10 ppt salt brackish water and fresh water for oviposition, while fresh water-derived Ae. aegypti preferred fresh water. The hatching of eggs from both brackish and fresh water-derived Ae. aegypti was less efficient and the time taken for larvae to develop into pupae was prolonged in 10 ppt salt brackish water. Ae. aegypti isolated from coastal brackish water were less resistant to the organophosphate insecticide malathion than inland fresh water Ae. aegypti. Brackish and fresh water-derived Ae. aegypti however were able to mate and produce viable offspring in the laboratory. The results suggest that development in brackish water is characterised by pertinent biological changes, and that there is restricted genetic exchange between coastal brackish and inland fresh water Ae. aegypti isolates from sites 5 km apart. The findings highlight the need for monitoring Ae. aegypti developing in coastal brackish waters and extending vector control measures to their habitats. PMID:25170879

  16. Advanced Membrane Filtration Technology for Cost Effective Recovery of Fresh Water from Oil & Gas Produced Brine

    SciTech Connect

    David B. Burnett

    2005-09-29

    This study is developing a comprehensive study of what is involved in the desalination of oil field produced brine and the technical developments and regulatory changes needed to make the concept a commercial reality. It was originally based on ''conventional'' produced water treatment and reviewed (1) the basics of produced water management, (2) the potential for desalination of produced brine in order to make the resource more useful and available in areas of limited fresh water availability, and (3) the potential beneficial uses of produced water for other than oil production operations. Since we have begun however, a new area of interest has appeared that of brine water treatment at the well site. Details are discussed in this technical progress report. One way to reduce the impact of O&G operations is to treat produced brine by desalination. The main body of the report contains information showing where oil field brine is produced, its composition, and the volume available for treatment and desalination. This collection of information all relates to what the oil and gas industry refers to as ''produced water management''. It is a critical issue for the industry as produced water accounts for more than 80% of all the byproducts produced in oil and gas exploration and production. The expense of handling unwanted waste fluids draws scarce capital away for the development of new petroleum resources, decreases the economic lifetimes of existing oil and gas reservoirs, and makes environmental compliance more expensive to achieve. More than 200 million barrels of produced water are generated worldwide each day; this adds up to more than 75 billion barrels per year. For the United States, the American Petroleum Institute estimated about 18 billion barrels per year were generated from onshore wells in 1995, and similar volumes are generated today. Offshore wells in the United States generate several hundred million barrels of produced water per year. Internationally

  17. Molecular identification of the occurrence of magnetotactic bacteria in fresh water sediments (Czech Republic)

    PubMed Central

    Rulík, Martin; Chaudhary, Prem Prashant

    2014-01-01

    Magnetotactic bacteria (MTB) are of considerable interest because of their importance in the manufacture of various bioinspired materials. In order to find out the status of magnetotactic bacteria at three different sediment in Czech Republic, samples collected from both standing and running freshwaters were subjected to molecular diversity analysis by using 16S rRNA gene approach. Total community DNA from sediment sample was isolated and used for PCR, cloning and sequence analysis. Of the 24 analyzed sequences, six clones are closely related to Magnetobacterium sp. affiliated with the Nitrospira phylum which showed the dominance of Magnetobacterium phylotypes in the sample. This study will provide useful insight about the community structure of MTB in this particular geographical region. However more detailed and specific studies are warranted in order to properly assess the community structure of MTB’s in fresh water sediments. PMID:25763029

  18. [Two new species of Myxidium (Myxosporea: Myxidiidae) parasites of fresh water fish in Cameroon].

    PubMed

    Fomena, A; Lekeufack, Folefack G B; Bouix, G

    2010-03-01

    The study of Myxosporidia infecting Clarias pachynema Boulenger, 1903 (Clariidae), Ctenopoma petherici Günther, 1864 (Anabantidae) and Parachanna obscura (Günther, 1861) (Channidae) from the basin of Nkam in Cameroon, revealed the presence of two new species of Myxosporidia of the genus Myxidium Bütschli, 1882, all found in the gall bladder of their hosts. These new species were: Myxidium nkamensis n. sp., found in Clarias pachynema and M. sangei n. sp. found in the gall bladder wall of Parachanna obscura. Two other species, Myxidium petrocephali Fomena and Bouix, 1986 and M. distichodi Kostoïngué, Faye and Toguebaye, 1998 were found in new hosts. The list of Myxidium species parasitizing African fresh water fishes is given.

  19. Applicability of ERTS to Antarctic iceberg resources. [harvesting sea ice for fresh water

    NASA Technical Reports Server (NTRS)

    Hult, J. L. (Principal Investigator); Ostrander, N. C.

    1973-01-01

    The author has identified the following significant results. This investigation explorers the applicability of ERTS to (1) determine the Antarctic sea ice and environmental behavior that may influence the harvesting of icebergs, and (2) monitor iceberg locations, characteristics, and evolution. Imagery has shown that the potential applicability of ERTS to the research, planning, and harvesting operations can contribute importantly to the glowing promise derived from broader scope studies for the use of Antarctic icebergs to relieve a growing global thirst for fresh water. Several years of comprehensive monitoring will be necessary to characterize sea ice and environmental behavior and iceberg evolution. Live ERTS services will assist harvesting control and claiming operations and offer a means of harmonizing entitlements of iceberg resources. The valuable ERTS services will be more cost effective than other means will be easily justified and borne by the iceberg harvesting operations.

  20. Comment on "The deglaciation over the Laurentide Fan: History of diatoms, IRD, ice and fresh water"

    NASA Astrophysics Data System (ADS)

    Carlson, Anders E.; Clark, Peter U.; Leydet, David J.; Rayburn, John A.

    2016-05-01

    Gil et al. (2015) present new and existing data in core OCE326 GGC14 from the Laurentian Fan off of the Laurentian Channel. In their study, they criticize data published from the same core by Obbink et al. (2010) and from a nearby core by Carlson et al. (2007). One major conclusion of Gil et al. (2015) is that "The YD [Younger Dryas cold event; 12.9-11.7 ka; Rasmussen et al., 2006] cannot be regarded as an event triggered by a fresh water input through the Laurentian Channel since only a weak brief input nearly 1000 yrs after its onset is recorded." Here we show that their study misrepresents existing data, and ignores their own data and its uncertainty, which leads to different conclusions than in Gil et al. (2015).

  1. Isolation, purification and identification of etiolation substrate from fresh-cut Chinese water-chestnut (Eleocharis tuberosa).

    PubMed

    Pan, Yong-Gui; Li, Yi-Xiao; Yuan, Meng-Qi

    2015-11-01

    Fresh cut Chinese water-chestnut is a popular ready-to-eat fresh-cut fruit in China. However, it is prone to etiolation and the chemicals responsible for this process are not known yet. To address this problem, we extracted phytochemicals from etiolated Chinese water-chestnut and separated them using MPLC and column chromatography. Four compounds were obtained and their structures were determined by interpretation of UV, TLC, HPLC and NMR spectral data and by comparison with reported data. We identified these compounds as eriodictyol, naringenin, sucrose and ethyl D-glucoside. Among those, eriodictyol and naringenin were both isolated for the first time in fresh-cut Chinese water-chestnut and are responsible for the yellowing of this fruit cutting.

  2. Inductively coupled plasma mass spectrometry for the determination of aluminum, calcium, chlorine, iron, magnesium, manganese and sodium in fresh water

    SciTech Connect

    Vanhaecke, F.; Vandecasteele, C.; Dams, R. )

    1992-05-01

    Al, Ca, Cl, Fe, Mg, Mn and Na were determined in two candidate reference materials, low mineral content fresh water CRM 398 and high mineral content fresh water CRM 398 and high mineral content fresh water CRM 399. The concentration of the elements ranged from 30 ng/g (for Mn) to 80 {mu}/g (for Ca). Metals present at relatively high concentrations were determined under operating conditions of non-optimal sensitivity, but with no loss in precision. The accuracy and precision of the results obtained by ICP-MS were checked by comparing with other analytical techniques and laboratories. The agreement was excellent. This study showed that ICP-MS not only yields excellent results for interference-free elements at trace levels, but is also competitive for less ideal elements e.g. Ca, Fe and Cl.

  3. Microbial and chemical characterization of underwater fresh water springs in the Dead Sea.

    PubMed

    Ionescu, Danny; Siebert, Christian; Polerecky, Lubos; Munwes, Yaniv Y; Lott, Christian; Häusler, Stefan; Bižić-Ionescu, Mina; Quast, Christian; Peplies, Jörg; Glöckner, Frank Oliver; Ramette, Alban; Rödiger, Tino; Dittmar, Thorsten; Oren, Aharon; Geyer, Stefan; Stärk, Hans-Joachim; Sauter, Martin; Licha, Tobias; Laronne, Jonathan B; de Beer, Dirk

    2012-01-01

    Due to its extreme salinity and high Mg concentration the Dead Sea is characterized by a very low density of cells most of which are Archaea. We discovered several underwater fresh to brackish water springs in the Dead Sea harboring dense microbial communities. We provide the first characterization of these communities, discuss their possible origin, hydrochemical environment, energetic resources and the putative biogeochemical pathways they are mediating. Pyrosequencing of the 16S rRNA gene and community fingerprinting methods showed that the spring community originates from the Dead Sea sediments and not from the aquifer. Furthermore, it suggested that there is a dense Archaeal community in the shoreline pore water of the lake. Sequences of bacterial sulfate reducers, nitrifiers iron oxidizers and iron reducers were identified as well. Analysis of white and green biofilms suggested that sulfide oxidation through chemolitotrophy and phototrophy is highly significant. Hyperspectral analysis showed a tight association between abundant green sulfur bacteria and cyanobacteria in the green biofilms. Together, our findings show that the Dead Sea floor harbors diverse microbial communities, part of which is not known from other hypersaline environments. Analysis of the water's chemistry shows evidence of microbial activity along the path and suggests that the springs supply nitrogen, phosphorus and organic matter to the microbial communities in the Dead Sea. The underwater springs are a newly recognized water source for the Dead Sea. Their input of microorganisms and nutrients needs to be considered in the assessment of possible impact of dilution events of the lake surface waters, such as those that will occur in the future due to the intended establishment of the Red Sea-Dead Sea water conduit. PMID:22679498

  4. Experimental evaluation of four infiltration models for calcareous soil irrigated with treated untreated grey water and fresh water

    NASA Astrophysics Data System (ADS)

    Gharaibeh, M. A.; Eltaif, N. I.; Alrababah, M. A.; Alhamad, M. N.

    2009-04-01

    Infiltration is vital for both irrigated and rainfed agriculture. The knowledge of infiltration characteristics of a soil is the basic information required for designing an efficient irrigation system. The objective of the present study was to model soil infiltration using four models: Green and Ampt, Horton, Kostaikov and modified Kostiakov. Infiltration tests were conducted on field plot irrigated with treated, untreated greywater and fresh water. The field water infiltration data used in these models were based on double ring infiltrometer tests conducted for 4 h. The algebraic parameters of the infiltration models and nonlinear least squares regression were fitted using measured infiltration time [I (t)] data. Among process-based infiltration models, the Horton model performed best and matched the measured I (t) data with lower sum of squares (SS).

  5. First report of toxic Cylindrospermopsis raciborskii and Raphidiopsis mediterranea (Cyanoprokaryota) in Egyptian fresh waters.

    PubMed

    Mohamed, Zakaria A

    2007-03-01

    Cylindrospermopsis raciborskii, a potentially toxic and highly adaptable freshwater cyanobacterium, was believed to have been misidentified in the Nile at the end of the 19th century. This study reports the presence of Cylindrospermopsis raciborskii and Raphidiopsis mediterranea for the first time in Egyptian fresh waters since that time. Cylindrospermopsis raciborskii appeared in the El-Dowyrat fish pond during May 2002, when bottom waters reached, as a result of climatic change, sufficiently high temperatures to allow the germination of its akinetes in the sediments. Both C. raciborskii and R. mediterranea showed seasonal variations, with highest densities recorded in August of each year. The count of the two species correlated positively with pH, temperature and conductance, and negatively with nutrients, during the study period. The densities of C. raciborskii and R. mediterranea varied significantly along the depth profile of this pond, with peaks obtained at 1 and 0.5m, respectively. Isolates of C. raciborskii and R. mediterranea from this pond exhibited toxicity to Artemia salina, Daphnia magna and mice. Cylindrospermopsis raciborskii extracts had hepatotoxic effects on mice, but R. mediterranea extracts showed neurotoxic effects on mice. The identification of toxic C. raciborskii and R. mediterranea in this pond should be considered during the monitoring of cyanobacteria in drinking and recreational water sources in Egypt.

  6. Use of electrolyzed water ice for preserving freshness of pacific saury (Cololabis saira).

    PubMed

    Kim, Won-Tae; Lim, Yeong-Seon; Shin, Il-Shik; Park, Hoon; Chung, Donghwa; Suzuki, Tetsuya

    2006-09-01

    The effects of electrolyzed water ice (EW-ice), compared with traditional tap water ice (TW-ice), on the microbiological, chemical, and sensory quality of Pacific saury (Cololabis saira) stored for a period of up to 30 days at 4 degrees C were evaluated. EW-ice with active chlorine at a concentration of 34 mg/kg was prepared from weak acidic electrolyzed water, whose pH, oxidation-reduction potential, and chlorine content were 5, 866 mV, and 47 mg/liter, respectively. Microbiological analysis showed that EW-ice, compared with TW-ice, markedly inhibited the growth of both aerobic and psychrotrophic bacteria in saury flesh during refrigerated storage, primarily because of the action of active chlorine. Chemical analysis revealed that EW-ice retarded the formation of volatile basic nitrogen and thiobarbituric acid-reactive substances and reduced the accumulation of alkaline compounds in the fish flesh in comparison with TW-ice. Sensory analysis confirmed that the freshness of saury was better preserved in EW-ice than in TW-ice and showed that the saury stored in EW-ice had a shelf life that was about 4 to 5 days longer than the fish stored in TW-ice. PMID:16995524

  7. Cassini capturing of freshly-produced water-group ions in the Enceladus torus

    NASA Astrophysics Data System (ADS)

    Yaroshenko, V. V.; Miloch, W. J.; Thomas, H. M.; Morfill, G. E.

    2012-09-01

    The water vapor plume on the geological-active south-polar region of the moon Enceladus is recognized as the main source of Saturn's neutral torus centered on the Enceladus orbit. The composition of the torus is dominated by water group species. Recent in situ Cassini plasma spectrometer measurements indicate the existence of freshly produced, slow and non-thermalized water group ions throughout the Enceladus torus including regions far from the moon. We report the results of modeling spacecraft-plasma interactions in the environment relevant for the Enceladus torus to show that new-born non-thermalized ions will inevitably be captured by the electric fields arising around the charged spacecraft. The associated plasma configuration can directly impact the plasma measurements and thus is important for reliable interpretation of data obtained by Cassini instruments in the Enceladus torus. The simulation results appear to be partially supported by Cassini observations and can provide new insights into intricate process of Enceladus-plasma interactions.

  8. Interaction of a fresh water lake and a karstic spring via a syncline fold.

    PubMed

    Rezaei, Abolfazl; Zare, Mohammad; Raeisi, Ezzatollah; Ghanbari, Reza Namdar

    2013-03-01

    Kaftar Lake is a high-altitude fresh water lake located in High Zagros, south of Iran. Despite the high annual evaporation to precipitation ratio in the area, lake water electrical conductivity is usually lower than 1000 µS/cm, this may be due to high seepage from the floor of the lake. Therefore, the hypothesis of possible underground connections between Namdan Basin, where the lake is located, and the surrounding basins with lower elevation (Aspas and Dehbid Basins) was investigated. Hydrogeology, hydrochemistry, and stable isotopes data of the lake and surrounding basins along with the lake water balance study were applied to test the hypothesis. Results indicate that Kaftar Lake has no connection with Aspas Basin in south, but it is hydraulically connected to Dehbid Basin. In Dehbid Basin, "Ghasr_e_Yaghoob spring" (average discharge ≅1200 L/s) emerges from a small outcrop (about 0.8 km(2) ) of Daryan limestone Formation, where this outcrop is much smaller than the required recharge area for such average discharge rate. The study shows that this spring is recharged by Kaftar Lake and Namdan Basin aquifer, through Daryan Formation of Gandboee Syncline located to the northern part of the lake.

  9. Contaminant Loading in Drainage and Fresh Water Used for Wetland Management at Stillwater National Wildlife Refuge

    PubMed

    Kilbride; Paveglio; Altstatt; Henry; Janik

    1998-08-01

    Throughout the western United States, studies have identified various detrimental effects of contaminants to aquatic biota from the use of agricultural drainage water for management of arid wetlands. However, little is known about the relative contributions of contaminant loading from pollutants dissolved in water compared with those carried by drifting material (e.g., detritus) associated with drainage water. Consequently, we determined loading rates for contaminants dissolved in water and those incorporated by drifting material for drainage (Diagonal Drain) as well as fresh (S-Line Canal) water used for wetland management at Stillwater National Wildlife Refuge (SNWR), Nevada during the early, middle, and late periods of the irrigation season (June through mid-November) in 1993. We found loading rates for trace elements throughout the irrigation season were almost entirely (> 98%) associated with contaminants dissolved in the water rather than incorporated by drift. Although drift contributed little to the total loading for trace elements to SNWR wetlands, contaminant concentrations were much greater in drift compared with those dissolved in water. Loading rates for dissolved As, B, Hg, and total dissolved solids (TDS) differed among periods for the Diagonal Drain. Along the Diagonal Drain, loading rates for dissolved As, B, Hg, Mo, unionized ammonia (NH3-N), TDS, and Zn differed among its three sampling sites. B was the only trace element with differences in loading rates for drift among periods from the Diagonal Drain. In contrast, loading rates for As, B, Cr, Cu, Hg, Se, and Zn in drift differed among periods for the S-Line Canal. Along Diagonal Drain, loading rates in drift for B (middle and late periods), Cr, Cu, and Zn differed among sites. Hg (x- >/= 12.0 ng/L) and NH3-N (x- >/= 0.985 mg/L) dissolved in water as well as B (x- >/= 97.4 µg/g DW) and Hg (x- >/= 0.461 µg/g DW) in drift from the Diagonal Drain and S-Line Canal exceeded screening levels (SLs

  10. The effect on slurry water as a fresh water replacement in concrete properties

    NASA Astrophysics Data System (ADS)

    Kadir, Aeslina Abdul; Shahidan, Shahiron; Hai Yee, Lau; Ikhmal Haqeem Hassan, Mohd; Bakri Abdullah, Mohd Mustafa Al

    2016-06-01

    Concrete is the most widely used engineering material in the world and one of the largest water consuming industries. Consequently, the concrete manufacturer, ready mixed concrete plant is increased dramatically due to high demand from urban development project. At the same time, slurry water was generated and leading to environmental problems. Thus, this paper is to investigate the effect of using slurry water on concrete properties in term of mechanical properties. The basic wastewater characterization was investigated according to USEPA (Method 150.1 & 300.0) while the mechanical property of concrete with slurry water was compared according to ASTM C1602 and BS EN 1008 standards. In this research, the compressive strength, modulus of elasticity and tensile strength were studied. The percentage of wastewater replaced in concrete mixing was ranging from 0% up to 50%. In addition, the resulted also suggested that the concrete with 20% replacement of slurry water was achieved the highest compressive strength and modulus of elasticity compared to other percentages. Moreover, the results also recommended that concrete with slurry water mix have better compressive strength compared to control mix concrete.

  11. Microbial and Chemical Characterization of Underwater Fresh Water Springs in the Dead Sea

    PubMed Central

    Ionescu, Danny; Siebert, Christian; Polerecky, Lubos; Munwes, Yaniv Y.; Lott, Christian; Häusler, Stefan; Bižić-Ionescu, Mina; Quast, Christian; Peplies, Jörg; Glöckner, Frank Oliver; Ramette, Alban; Rödiger, Tino; Dittmar, Thorsten; Oren, Aharon; Geyer, Stefan; Stärk, Hans-Joachim; Sauter, Martin; Licha, Tobias; Laronne, Jonathan B.; de Beer, Dirk

    2012-01-01

    Due to its extreme salinity and high Mg concentration the Dead Sea is characterized by a very low density of cells most of which are Archaea. We discovered several underwater fresh to brackish water springs in the Dead Sea harboring dense microbial communities. We provide the first characterization of these communities, discuss their possible origin, hydrochemical environment, energetic resources and the putative biogeochemical pathways they are mediating. Pyrosequencing of the 16S rRNA gene and community fingerprinting methods showed that the spring community originates from the Dead Sea sediments and not from the aquifer. Furthermore, it suggested that there is a dense Archaeal community in the shoreline pore water of the lake. Sequences of bacterial sulfate reducers, nitrifiers iron oxidizers and iron reducers were identified as well. Analysis of white and green biofilms suggested that sulfide oxidation through chemolitotrophy and phototrophy is highly significant. Hyperspectral analysis showed a tight association between abundant green sulfur bacteria and cyanobacteria in the green biofilms. Together, our findings show that the Dead Sea floor harbors diverse microbial communities, part of which is not known from other hypersaline environments. Analysis of the water’s chemistry shows evidence of microbial activity along the path and suggests that the springs supply nitrogen, phosphorus and organic matter to the microbial communities in the Dead Sea. The underwater springs are a newly recognized water source for the Dead Sea. Their input of microorganisms and nutrients needs to be considered in the assessment of possible impact of dilution events of the lake surface waters, such as those that will occur in the future due to the intended establishment of the Red Sea−Dead Sea water conduit. PMID:22679498

  12. High resolution Raman lidar measurements for the characterization of the water vapour inflow in the frame of the Hydrological Cycle in the Mediterranean Experiment

    NASA Astrophysics Data System (ADS)

    Di Girolamo, Paolo; Cacciani, Marco; Stelitano, Dario; Summa, Donato

    2013-04-01

    The University of BASILicata Raman Lidar system (BASIL) was deployed in Candillargues (Southern France, Lat: 43°37' N, Long: 4° 4' E) in the frame of the Hydrological Cycle in the Mediterranean Experiment - HyMeX. Within this experiment a major field campaign (Special Observation Period 1-SOP1, September to November 2012) took place over the Northwestern Mediterranean Sea and its surrounding coastal regions in France, Italy and Spain, with a specific focus on the study of heavy precipitation and flash-flood events. During HyMeX-SOP1, BASIL operated between 5 September and 5 November 2012, collecting more than 600 hours of measurements, distributed over 51 measurement days and 19 intensive observation periods (IOPs). The major feature of BASIL is represented by its capability to perform high-resolution and accurate measurements of atmospheric temperature and water vapour, both in daytime and night-time, based on the application of the rotational and vibrational Raman lidar techniques in the UV (Di Girolamo et al., 2004, 2006, 2009). This makes it an ideal tool for the characterization of the water vapour inflow in Southern France, which is important piece of information to improve the comprehension and forecasting capabilities of heavy precipitations in the Northwestern Mediterranean basin. Preliminary measurements from this field deployment will be illustrated and discussed at the Conference. These measurements allow to monitor and characterize the marine atmospheric flow that transport moist and conditionaly unstable air towards the coasts, which is feeding into the HPE events in Southern France. Measurements from BASIL can also be used to better characterize Planetary Boundary Layer moisture transport mechanisms from the surface to deep-convection systems. Besides temperature and water vapour, BASIL also provides measurements of the particle (aerosol/cloud) backscattering coefficient at 355, 532 and 1064 nm, of the particle extinction coefficient at 355 and 532

  13. Water Follies: Groundwater Pumping and the Fate of America's Fresh Waters

    NASA Astrophysics Data System (ADS)

    Glennon, R.

    2002-12-01

    The next time you open a bottle of spring water, consider that it may have come from a well that is drying up a blue-ribbon trout stream. The next time you super-size a meal at McDonald's, note that the fries are all the same length. That's because the potato farmers irrigate their fields with groundwater from wells, some adjacent to nearby rivers. The next time you purchase gold jewelry, consider that it may have come from a mine that has pumped so much groundwater to de-water the gold-bearing rock that 60 to100 years will pass before the water table recovers. The next time you water your suburban lawn, pause to reflect on what that's doing to the nearby wetland. And the next time you visit Las Vegas and flip on the light in your hotel room, consider that the electricity may have been generated by a coal-fired power plant supplied by a slurry pipeline that uses groundwater critical to springs sacred to the Hopi people. These and countless other seemingly innocuous activities reflect our individual and societal dependence on groundwater that is hydrologically connected to surface water. Hydrologists understand that ground and surface water are interconnected, but frequently the legal rules governing water distinguish between ground and surface water. This has led to groundwater pumping that has dried up many rivers, particularly in the arid West. In Arizona, many once verdant streams have become desiccated sandboxes as city, mines, and farms pumped groundwater to such an extent that surface flows were totally depleted. The problem of the impact of groundwater pumping on the environment, however, is not confined to the arid West. It is an enormous national, indeed international problem. This presentation will focus on the United States and illustrate with examples from around the country the array of environmental problems caused by excessive groundwater pumping. The locations of these case studies range from Maine to California, from Minnesota to Florida, and from

  14. Carbon cycle. Sunlight controls water column processing of carbon in arctic fresh waters.

    PubMed

    Cory, Rose M; Ward, Collin P; Crump, Byron C; Kling, George W

    2014-08-22

    Carbon in thawing permafrost soils may have global impacts on climate change; however, the factors that control its processing and fate are poorly understood. The dominant fate of dissolved organic carbon (DOC) released from soils to inland waters is either complete oxidation to CO2 or partial oxidation and river export to oceans. Although both processes are most often attributed to bacterial respiration, we found that photochemical oxidation exceeds rates of respiration and accounts for 70 to 95% of total DOC processed in the water column of arctic lakes and rivers. At the basin scale, photochemical processing of DOC is about one-third of the total CO2 released from surface waters and is thus an important component of the arctic carbon budget.

  15. Does salt water intrusion constitute a mercury contamination risk for coastal fresh water aquifers?

    PubMed

    Protano, G; Riccobono, F; Sabatini, G

    2000-12-01

    Four different sampling surveys were carried out in 1998 to evaluate the possible causes of severe mercury contamination involving many wells spread over a vast territory along the coast of southern Tuscany (Italy). Several samples of groundwater and coastal sea water were collected to determine the Hg, Cl, Ar, He and N contents. Anthropogenic or deep-seated sources of the Hg involved in the contamination event can be excluded. The observed coupling of Hg pollution with progressive salt water intrusion along the coastal aquifer indicates a close causal relation between these two phenomena.

  16. Toxic effects of the herbicide Roundup in the guppy Poecilia vivipara acclimated to fresh water.

    PubMed

    Harayashiki, Cyntia Ayumi Yokota; Varela, Antonio Sergio; Machado, Anderson Abel de Souza; Cabrera, Liziara da Costa; Primel, Ednei Gilberto; Bianchini, Adalto; Corcini, Carine Dahl

    2013-10-15

    Although it is believed that glyphosate-based herbicides are relatively nontoxic to humans, its broad use in agriculture and consequent contamination of aquatic systems is a concern. In the present study, reproductive (sperm quality) and biochemical parameters (acetylcholinesterase and glutathione S-transferase activity, lipoperoxidation, and antioxidant capacity against peroxyl radicals) were evaluated in adult guppies (Poecilia vivipara) acclimated to fresh water and exposed (96 h) to environmentally realistic concentrations of glyphosate (130 and 700 μg L(-1)) as the commercial formulation Roundup. Male guppies exposed to Roundup showed a poorer sperm quality, measured as reduced plasmatic membrane integrity, mitochondrial functionality, DNA integrity, motility, motility period and concentration of spermatic cells, than those kept under control condition (no Roundup addition to the water). Most of the spermatic parameters analyzed showed strong association to each other, which may help to understand the mechanisms underlying the observed reduction in sperm quality. Exposure to Roundup did not alter the biochemical parameters analyzed, though differences between genders were observed and deserve further investigations. Findings from the present study suggest that exposure to environmentally relevant concentrations of Roundup may negatively affect at long-term the reproduction of P. vivipara, with consequent changes in fish populations inhabiting environments contaminated with the herbicide.

  17. Chemical characterization of high molecular weight dissolved organic matter in fresh and marine waters

    NASA Astrophysics Data System (ADS)

    Repeta, Daniel J.; Quan, Tracy M.; Aluwihare, Lihini I.; Accardi, AmyMarie

    2002-03-01

    The high molecular weight fraction of dissolved organic matter in a suite of lakes, rivers, seawater, and marine sediment interstitial water samples was collected by ultrafiltration and characterized by molecular level and spectroscopic techniques. Proton nuclear magnetic resonance spectra of all samples show a high degree of similarity, with major contributions from carbohydrates, bound acetate, and lipids. Molecular level analyses of neutral sugars show seven monosaccharides, rhamnose, fucose, arabinose, xylose, mannose, glucose, and galactose, to be abundant, and to occur in comparable relative amounts in each sample. Previous studies have emphasized the distinctive composition of dissolved humic substances in fresh and marine waters, and have attributed these differences to sources and transformations of organic matter unique to each environment. In contrast we find a large fraction of freshwater high molecular weight dissolved organic matter (HMWDOM; > 1kD) to be indistinguishable from marine HMWDOM in bulk and molecular-level chemical properties. Aquatic HMWDOM is similar in chemical composition to biologically derived acylated heteropolysaccharides isolated from marine algal cultures, suggesting a biological source for some fraction of persistent HMWDOM. High molecular weight DOC contributes 51 ± 26% of the total DOC, and monosaccharides 18 ± 8% of the total HMWDOC in our freshwater samples. These contributions are on average higher and more variable, but not significantly different than for surface seawater (30% and 16% respectively). Biogeochemical processes that produce, accumulate, and recycle DOM may therefore share important similarities and be broadly comparable across a range of environmental settings.

  18. Risk assessment of cryptosporidium and giardia in water irrigating fresh produce in Mexico.

    PubMed

    Mota, Alain; Mena, Kristina D; Soto-Beltran, Marcela; Tarwater, Patrick M; Cháidez, Cristóbal

    2009-10-01

    A rise in foodborne outbreaks in the United States associated with fresh produce has resulted in increased concerns with the importation of fruits and vegetables. Mexico is a major exporter of produce to the United States, particularly tomatoes and bell peppers. A quantitative microbial risk assessment (QMRA) was conducted to evaluate the public health impact of protozoan-laden water irrigating produce in Culiacan, Sinaloa, Mexico. Specifically, a QMRA was conducted to address the human health impact associated with consumption of tomatoes, bell peppers, cucumbers, and lettuce irrigated with water contaminated with Cryptosporidium and Giardia. Yearly infection risks were estimated and assumed a 120-day exposure in a given year. Annual risks range from 9 x 10(-6) for Cryptosporidium at the lowest concentration associated with bell peppers to almost 2 x 10(-1) for exposure to Giardia on lettuce at the highest detected concentration. With the relatively high number of illnesses resulting from produce-related outbreaks, addressing pre- and postharvest points of contamination for fruits and vegetables consumed raw should be a food industry priority. This research shows how QMRA can be used to interpret microbial contamination data for public health significance and subsequently provide the foundation for guideline development. PMID:19833043

  19. Coupling reverse osmosis with electrodialysis to isolate natural organic matter from fresh waters.

    PubMed

    Koprivnjak, J F; Perdue, E M; Pfromm, P H

    2006-10-01

    Reverse osmosis (RO) has proven to be an effective method for the concentration of natural organic matter (NOM) from fresh waters, but an undesirable consequence of this process is the co-concentration of some inorganic solutes. Accordingly, current practice yields solutions of NOM that, upon desalting and freeze-drying, are converted into dry solids containing finely dispersed sulfuric acid and silicic acid (H(4)SiO(4)). These acids will contribute to the apparent carboxylic and phenolic contents of NOM, leading to an overestimation of both. NOM may also be chemically altered by sulfuric acid, which reacts strongly with many classes of organic compounds. The sulfur content and ash content of NOM will be elevated in the presence of sulfuric acid and H(4)SiO(4). The goal of this study is to develop and test a method in which the removal of water by RO is coupled with the removal of salts by electrodialysis (ED). Like RO, ED is a relatively mild treatment that enables the desalting of NOM solutions without subjecting those samples to conditions of extremely high or low pH. The end product of the coupled process is a desalted, concentrated liquid sample from which low-ash NOM can be obtained as a freeze-dried solid material. In this study, the efficacy of ED for desalting NOM is evaluated using concentrated synthetic river waters and actual concentrated (by RO) river waters. Under optimal operating conditions, both sulfate and silica can be largely removed from RO-concentrated solutions of riverine NOM with only an average loss of 3% of total organic carbon. PMID:16952387

  20. Phosphorus dynamics in soils irrigated with reclaimed waste water or fresh water - A study using oxygen isotopic composition of phosphate

    USGS Publications Warehouse

    Zohar, I.; Shaviv, A.; Young, M.; Kendall, C.; Silva, S.; Paytan, A.

    2010-01-01

    Transformations of phosphate (Pi) in different soil fractions were tracked using the stable isotopic composition of oxygen in phosphate (??18Op) and Pi concentrations. Clay soil from Israel was treated with either reclaimed waste water (secondary, low grade) or with fresh water amended with a chemical fertilizer of a known isotopic signature. Changes of ??18Op and Pi within different soil fractions, during a month of incubation, elucidate biogeochemical processes in the soil, revealing the biological and the chemical transformation impacting the various P pools. P in the soil solution is affected primarily by enzymatic activity that yields isotopic equilibrium with the water molecules in the soil solution. The dissolved P interacts rapidly with the loosely bound P (extracted by bicarbonate). The oxides and mineral P fractions (extracted by NaOH and HCl, respectively), which are considered as relatively stable pools of P, also exhibited isotopic alterations in the first two weeks after P application, likely related to the activity of microbial populations associated with soil surfaces. Specifically, isotopic depletion which could result from organic P mineralization was followed by isotopic enrichment which could result from preferential biological uptake of depleted P from the mineralized pool. Similar transformations were observed in both soils although transformations related to biological activity were more pronounced in the soil treated with reclaimed waste water compared to the fertilizer treated soil. ?? 2010 Elsevier B.V.

  1. Discovery of a Balkan fresh-water fauna in the Idaho formation of Snake River Valley, Idaho

    USGS Publications Warehouse

    Dall, W.H.

    1925-01-01

    In 1866 Gabb described Melania taylori and Lithasia antiqua "from a fresh-water deposit on Snake River, Idaho Territory, on the road from Fort Boise to the Owyhee mining country. Collected by A. Taylor." He states that a small bivalve, perhaps a Sphaerium, was associated with them.

  2. Fresh-water planarias and a marine planaria are relatively dissimilar in the 5S rRNA sequences.

    PubMed

    Ohama, T; Kumazaki, T; Hori, H; Osawa, S; Takai, M

    1983-01-25

    The nucleotide sequences from fresh-water Dugesia japonica and marine Planocera reticulata have been determined. The similarity between these two species is only 69%. The Planocera sequence reveals nearly 80% similarity (72-81%) to the sequences of multicellular animals, while the Dugesia sequences are considerably different from them (66-73%).

  3. Seasonal Variations in δ18O of Inflowing River Water, Lake Water, Sediment Trap Material and Ostracod Shells of Lake Nam Co and its Catchment (Tibet, China) — a Proxy Calibration Study

    NASA Astrophysics Data System (ADS)

    Daut, G.; Wang, J.; Ju, J.; Plessen, B.; Fürstenberg, S.; Baade, J.; Frenzel, P.; Haberzettl, T.; Maeusbacher, R.; Zhu, L.

    2014-12-01

    δ18O is a very common proxy used in palaeoclimate studies all over the world, but for most parts of the world and especially the Tibetan Plateau modern studies that trace the pathway of this isotope from sink to source are lacking. In this study, financed by the BMBF (German Ministry of Science and Education, Project CADY), we present data that fill this gap. The study was performed in the terminal lake Nam Co, the biggest lake on the central Tibetan Plateau and its catchment. Water of the main tributaries to the lake, lake water at three different stations and from different water depths, bulk carbonate collected from different water depths with sediment traps and shells of living ostracods were collected for one year at lake Nam Co in approx. monthly intervals and analyzed for their δ18O values. The inflowing river waters mainly reflect the precipitation and show regional as well as seasonal variations depending on their location and on Monsoon or Westerly season but are in general on the global meteoric waterline. The lake water shows only minor vertical and spatial variations and is clearly off the meteoric waterline due to strong evaporation effects in this terminal lake. δ18O values of the bulk carbonate of sediment collected in sediment traps show only minor vertical and spatial variations during the year and the δ18O offset compared to the lake water is with around 1 ‰ quite small. Most probably this is attributed to chemical fractionation during formation of monohydrocalcite in the water column. In contrast δ18O values of ostracod shells are significant heavier than the lake water indicating isotopic fractionation (vital effect) during shell formation. In addition a seasonal variability is visible. The data of this proxy calibration study give now for the first time the opportunity to validate δ18O proxy data measured on core material from Lake Nam Co for their palaeoclimatic significance.

  4. Water-table contours, directions of ground-water movement, and measurements of inflow to American Falls Reservoir, Southeastern Idaho, April 1984

    USGS Publications Warehouse

    Young, H.W.

    1984-01-01

    In 1978 the U.S. Geological Survey began a 5-year study of the High Plains regional aquifer system to provide hydrologic information for evaluating the effects of long-term development of the aquifer and to develop a capability for predicting aquifer response to alternative changes in ground-water management. By use of a digital model, this report presents a quantitative description of the High Plains aquifer in Oklahoma. The High Plains aquifer consists predominantly of the Tertiary Ogallala Formation and overlying Quaternary alluvium and terrace deposits which are hydraulically connected to the High Plains aquifer. Much of the aquifer is underlain by formations of Permian through Cretaceous age, which generally have very small hydraulic conductivities. In some areas parts of underlying Triassic, Jurassic, or Cretaceous rocks are hydraulically connected with the aquifer. The High Plains aquifer is a water-table aquifer in which water moves generally to the east-southeast. Before the beginning of extensive irrigation of the 1960's, the aquifer was essentially in dynamic equilibrium with recharge from precipitation balanced by natural discharge from the aquifer. Ground-water discharge appeared in streams leaving the area or was returned to the atmosphere through evapotranspiration. Accurate records of irrigation pumpage are not available from the High Plains. In order to estimate irrigation pumpage, published records of crop distribution were used and a consumptive use was assigned to each principal irrigated crop. This method gave an estimated irrigation demand. Pumpage was taken as a percentage of the total irrigation demand. Irrigation has decreased ground-water discharge from the High Plains aquifer. Ground-water discharge was estimated as approximately 118 cubic feet per second in 1980. A finite-difference digital model was used to simulate flow in the High Plains aquifer. The recharge was adjusted so that 1980 ground-water discharge was 118 cubic feet per

  5. Improved method for measuring transparent exopolymer particles (TEP) and their precursors in fresh and saline water.

    PubMed

    Villacorte, Loreen O; Ekowati, Yuli; Calix-Ponce, Helga N; Schippers, Jan C; Amy, Gary L; Kennedy, Maria D

    2015-03-01

    Transparent exopolymer particles (TEP) and their precursors produced by phyto-/bacterio-planktons in fresh and marine aquatic environments are increasingly considered as a major contributor to organic/particulate and biological fouling in micro-/ultra-filtration and reverse osmosis membrane (RO) systems. However, currently established methods which are based on Alcian blue (AB) staining and spectrophotometric techniques do not measure TEP-precursors and have the tendency to overestimate concentration in brackish/saline water samples due to interference of salinity on AB staining. Here we propose a new semi-quantitative method which allows measurement of both TEP and their colloidal precursors without the interference of salinity. TEP and their precursors are first retained on 10 kDa membrane, rinsed with ultra-pure water, and re-suspended in ultra-pure water by sonication and stained with AB, followed by exclusion of TEP-AB precipitates by filtration and absorbance measurement of residual AB. The concentration is then determined based on the reduction of AB absorbance due to reaction with acidic polysaccharides, blank correction and calibration with Xanthan gum standard. The extraction procedure allows concentration of TEP and their pre-cursors which makes it possible to analyse samples with a wide range of concentrations (down to <0.1 mg Xeq/L). This was demonstrated through application of the method for monitoring these compounds in algal cultures and a full-scale RO plant. The monitoring also revealed that concentrations of the colloidal precursors were substantially higher than the concentration of TEP themselves. In the RO plant, complete TEP removal was observed over the pre-treatment processes (coagulation-sedimentation-filtration and ultrafiltration) but the TEP precursors were not completely removed, emphasising the importance of measuring this colloidal component to better understand the role of TEP and acidic polysaccharides in RO membrane fouling.

  6. Interspecific Aggressive Behaviour of Invasive Pumpkinseed Lepomis gibbosus in Iberian Fresh Waters

    PubMed Central

    Almeida, David; Merino-Aguirre, Raquel; Vilizzi, Lorenzo; Copp, Gordon H.

    2014-01-01

    Pumpkinseed Lepomis gibbosus (L.) are successful invaders in Europe, where this species exerts multiple ecological effects, mainly through trophic interactions. Behavioural interference represents a potential impact for native fauna and this is of particular conservation concern in the Iberian Peninsula because of the highly valuable endemic fauna inhabiting streams of this region. However, aggressive interactions have not previously been examined under natural conditions in Iberian fresh waters. To address this gap in knowledge, the aim of the present study was to assess the effect of pumpkinseed aggression on endemic fauna of an Iberian stream, the River Bullaque (central Spain). In September 2009, we analysed the aggression and environmental contexts of these behavioural interactions by snorkelling: aggressor size, aggression type, shoal size, previous activity to aggression, recipient species, response to aggression, microhabitat structure and prey availability. Small pumpkinseed displayed more threat and fewer pursuit behaviours relative to medium and large individuals, reflecting an ontogenetic behavioural shift from low to high aggression intensity. Small aggressors came from large shoals, with bottom feeding being the most frequently observed activity prior to an aggressive interaction; whereas large pumpkinseed were less gregarious and they were mostly ambulating within the water column prior to aggression. Recipient species of aggression included non-native crayfish and fishes, and more importantly, endemic fishes and frogs. Retreat was the most common response to aggression, irrespective of aggressor size. Small pumpkinseed displayed aggressive behaviours over coarse substrata containing elevated macrobenthos biomass; whereas aggression by large individuals was observed in deeper waters. These findings suggest that small and large pumpkinseed exert a high impact on other stream residents through aggression in competition for food and territory defence

  7. Nationwide monitoring of mercury in wild and farmed fish from fresh and coastal waters of Korea.

    PubMed

    Kim, Chan-Kook; Lee, Tae-Woo; Lee, Kyu-Tae; Lee, Jong-Hyeon; Lee, Chang-Bok

    2012-11-01

    Mercury (Hg) concentrations were monitored in wild and cultured fish collected from fresh and coastal waters in the Korean peninsula from April 2006 to August 2008 nationwide. Total Hg concentrations were reported for 5043 fish samples, including 78 species from 133 locations. Significant interspecies variation was noted in the Hg levels. The average Hg concentration in each fish species ranged from 6.31 μg kg(-1) for mullet (Mugil cephalus) to 200 μg kg(-1) for mandarin fish (Siniperca scherzeri). Among the species collected, the maximum concentration of Hg, 1720 μg kg(-1), was measured in an Amur catfish (Silurus asotus). Only wild freshwater fish exceeded the WHO ingestion standard. Wild freshwater piscivorous fish samples from a large artificial upstream lake contained the highest Hg levels. Hg concentrations were compared between fish groups categorized as wild and farmed fish from freshwater and coastal waters. Although the wild freshwater fish had similar size ranges, their Hg concentrations were higher than those of the other groups. Compared to the feed of farmed marine and freshwater fishes, the prey of wild freshwater fish had a higher Hg concentration, and the total Hg concentrations in freshwater and associated sediment samples were higher than those in coastal water and associated sediment samples. In the freshwater environment, piscivorous fish bioaccumulated two times more Hg than carnivorous and omnivorous fish and four times more than planktivorous fish. The difference in Hg concentrations among trophic groups might have been due to differences in the size of fish, in addition to the variations among different trophic groups. These data will be useful for developing the fish consumption advisory as a management measure to reduce Hg exposure.

  8. In-Situ Ion Analysis of Fresh Waters via an ISE Multiprobe and Artificial Neural Networks

    NASA Astrophysics Data System (ADS)

    Mueller, A. V.; Hemond, H.

    2010-12-01

    The ecological and geochemical sciences stand to substantially gain from capability for comprehensive, real-time, in-situ characterization of the chemical constituents of natural waters, e.g. by facilitating rapid high-resolution adaptive sampling campaigns and avoiding the potential errors and high costs related to traditional grab sample collection, transportation and in-lab analysis. In-situ chemical instrumentation also promotes the goals of large-scale monitoring networks, such as CUASHI and WATERS, by reducing the financial and human resources overhead required for traditional sampling at this scale. Problems of environmental remediation and monitoring of industrial waste waters would additionally benefit from such instrumental capacity. We have pursued in-situ measurement of all major ions contributing to the charge makeup (>99%) of oxic natural fresh waters via an instrument combining an array of ion-selective electrode (ISE) hardware with an appropriate multivariate signal processing architecture. Commercially available electrochemical sensors promote low cost and a fast development schedule, as well as easy maintenance and reproduction. Data processing techniques are adapted from artificial intelligence and chemometrics to extract accurate information from the corresponding in-situ data matrix. This architecture takes into account temperature, conductivity, and non-linearity effects, as well as taking advantage of sensor cross-selectivities traditionally considered as interferences. Chemical and mathematical constraints, e.g. charge balance and total ionic strength, provide further system-level information. Maximizing data recovery from the sensor array allows use of the instrument without the standard additions or ionic strength adjustment traditionally-required with use of ISEs. Initial work demonstrates the effectiveness of this methodology at predicting inorganic cations (sodium, potassium, calcium, and ammonium ) and hydrogen ion in a simplified

  9. Water-quality conditions of inflow, outflow, and impounded water at Rathbun Reservoir, Iowa, Clinton and Pomona Lakes, Kansas, and Harlan County Reservoir, Nebraska, May through August 1993

    USGS Publications Warehouse

    Ziegler, A.C.; Rasmussen, P.P.; Carlson, M.D.; Hargadine, D.A.

    1995-01-01

    During May through August 1993, water-quality samples were collected twice from selected sites in Rathbun Reservoir, Iowa, Clinton and Pomona Lakes, Kansas, and Harlan County Reservoir, Nebraska. Samples were analyzed for selected physical and chemical properties, bacteria, major ions, nutrients, selected metals, total organic carbon, selected herbicides, and chlorophyll-a and -b. During May through August 1993, precipitation at all four reservoirs exceeded mean precipitation at nearby long-term precipitation gages; precipitation ranged from 7.76 inches above the long-term mean at Pomona Lake to 12.62 inches above the long-term mean at Rathbun Reservoir. Reservoir water-surface elevations exceeded flood-pool elevation by 4 feet in Clinton Lake, by 19 feet in Pomona Lake, and by 2 feet in Harlan County Reservoir in July. Thermal stratification of water occurred at one site in Rathbun Reservoir in August, at two sites in Clinton Lake in May, at one site in Pomona Lake in June, and at one site in Harlan County Reservoir in June. Total triazine herbicide concentrations in water samples from all four reservoirs ranged from 0.2 to 19 micrograms per liter and were largest water samples from Rathbun Reservoir in June. Concen- trations of atrazine exceeded the U.S. Environmental Protection Agency's Maximum Contaminant Level of 3.0 micrograms per liter for drinking water in at least one sample each from Rathbun Reservoir, Clinton Lake, and Pomona Lake. Concentrations of cyanazine exceeded the U.S. Environmental Protection Agency's Maximum Contaminant Level of 1.0 microgram per liter in water samples from Rathbun Reservoir.

  10. A study on biological control of six fresh water snails of medical and veterinary importance.

    PubMed

    Abd-Allah, Karim F; Negm-Eldin, Mohsen M; Saleh, Mohamed H; El-Hamshary, Azza M S; El-Gozamy, Bothina M R; Aly, Nagwa S M

    2009-04-01

    This study evaluated the molluscicidal effect of Commiphora mnolmol oil extract (Myrrh), on control of six fresh water snails (Lymnaea natalensis, Bulinus truncatus, Biomphalaria alexandrina, Physa acuta, Melania tuberculata and Cleopatra bulimoides). Also, the extract effect on the egg masses of L. natalensis, B. truncatus, B. alexandrina and Ph. acuta was evaluated. Snails and egg masses were exposed at 16-20 degrees C to various concentrations (conc.). LD50 after 24 hours expo-sure were 264/132, 283/195, 230/252, 200/224, 241/246 & 241/246 ppm for young/adult of L. natalensis, B. truncatus, B. alexandrina, Ph. acuta, M. tuberculata and C. bulimnoides respectively. LDtoo after 24 hours exposure were 400/400 for L. natalensis, B. truncatus, B. alexandrina, M. tuberculata and C. bulimoides, and 300/300 for Ph. acuta. Also, complete mortality (100%) was achieved for the egg masses of L. natalensis, B. truncatus, B. alexandrina and Ph. acuta at concentrations of 300, 200, 300 & 400 ppm respectively. Lower concentrations gave the same results after longer exposure. LD100 of C. molmol oil extract (Myrrh) had a rapid lethal effect on the six snail species and their egg masses in high conc. of 300 & 400 ppm. Commiphora molmol is a promising plant to be included with the candidate plant molluscicides. The oil extract of this plant showed a remarkable molluscicidal activity against used snail species. PMID:19530615

  11. Growth and reproductive performance by different feed types in fresh water angelfish (Pterophyllum scalare Schultze, 1823).

    PubMed

    Kasiri, Milad; Farahi, Amin; Sudagar, Mohammad

    2012-01-01

    It is well established that reproduction is sensitive to the state of energy reserves, and that there is a balance between energy homeostasis and fertility. In this view, this study examined the effects of different diets on growth and reproductive performance of fresh water angelfish. Twenty four pairs of angelfish (weighing 3.58 ± 0.24 g) were fed with four types of diets including live earth worm (LEW), dried Tubifex (DT), dried Gammarus (DG) and prepared granulated feed (PGF), twice a day for 90 days. Reproductive parameters were measured between days 60 and 90. The significant increase in the gonadosomatic index (GSI), fecundity and hatchability brought about by the LEW were demonstrated by the higher number of spawned eggs and hatched larvae. The best growth observed significantly in PGF, and length of larvae was enhanced in this group, consequently. The numbers of dead and deformed fry were lower in the fish fed with PGF and LEW, but there was no significant difference among experimental groups. This study showed that breeders benefit from inclusion of prepared granulated feed and living earth worm during their growth and reproductive stages, and simultaneous using of them for achieving better results is suggested.

  12. Purification and characteristics of trypsin from masu salmon (Oncorhynchus masou) cultured in fresh-water.

    PubMed

    Kanno, Gaku; Yamaguchi, Takahito; Kishimura, Hideki; Yamaha, Etsurou; Saeki, Hiroki

    2010-09-01

    Trypsin from the pyloric ceca of masu salmon (Oncorhynchus masou) cultured in fresh water was purified by a series of chromatographies including Sephacryl S-200, Sephadex G-50 and diethylaminoethyl cellulose to obtain a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and native PAGE. The molecular mass of the purified trypsin was estimated to be approximately 24,000 Da by SDS-PAGE. The enzyme activity was strongly inhibited by phenylmethylsulfonyl fluoride, soybean trypsin inhibitor, and N ( alpha )-p-tosyl-L: -lysine chloromethyl ketone. Masu salmon trypsin was stabilized by calcium ion. The optimum pH of the masu salmon trypsin was around pH 8.5, and the trypsin was unstable below pH 5.0. The optimum temperature of the masu salmon trypsin was around 60 degrees C, and the trypsin was stable below 50 degrees C, like temperate-zone and tropical-zone fish trypsins. The N-terminal 20 amino acid sequence of the masu salmon trypsin was IVGGYECKAYSQPHQVSLNS, and its charged amino acid content was lower than those of trypsins from frigid-zone fish and similar to those of trypsins from temperate-zone and tropical-zone fish. In the phylogenetic tree, the masu salmon trypsin was classified into the group of the temperate-zone fish trypsin.

  13. Carbon sequestration capacity of sediments, algae, and zooplankton from fresh water aquaculture ponds.

    PubMed

    Anikuttan, K K; Adhikari, S; Kavitha, M; Jayasankar, P

    2016-07-01

    The contribution of aquaculture and allied activities to the emission of green house gases and consequently to global warming is an emerging concern among environmentalists in the recent past. However, there exists ample scope for aquaculture activities to sequester carbon and thus compensate for the carbon emissions linked to aquaculture. This article attempts to elucidate the carbon sequestration capacity of sediments, algae, and zooplankton from fresh water aquaculture ponds. The percent organic carbon in the pond sediments ranged from 0.39 to 1.31 with an average value of 0.912 ± 0.321 whereas the carbon sequestration capacity ranged from 0.442 to 1.882 MgC/ha (1 Mg = 10(6) g) with an average value of 1.018 ± 0.447 MgC/ha. In the case of zooplankton and algae from pond, the percent organic carbon was 7.688 ± 0.196 and 2.354 ± 0.047, respectively, whereas the total estimated carbon burial rate was 0.009 ± 0.005 and 0.150 ± 0.003 MgC/ha, respectively. These findings are discussed with the previous reports available at present and are found to be in comparable ranges.

  14. Ionoregulatory responses of the crayfish Orconectes immunis to selenium in fresh water

    SciTech Connect

    Short, T.M.

    1983-01-01

    The purpose of this study was to investigate the effects of chronic exposure to sublethal concentrations of selenium on fluid and tissue electrolyte balance of the crayfish Orconcectes immunis. An ionic profile of O. immunis was obtained from measurements of hemolymph sodium, potassium, calcium, magnesium, and copper in several populations of crayfish in eastern Colorado. The bioassay portion of the study consisted of groups of crayfish maintained in reconstituted fresh water while exposed for 30 days to concentrations of 0.01 mg/liter, 0.10 mg/liter, or 1.00 mg/liter selenium as sodium selenite. Exposure to selenium resulted in various branchial histopathologies to include hypertrophy, necrosis, and sloughing of the cuticular membrane. Hemolymph potassium and copper, however, were significantly reduced in crayfish exposed for 10 days to 1.00 mg/liter selenium and 30 days to 0.10 mg/liter selenium. Copper appeared to be the more responsive to selenium toxicity with reductions of 47.4%-53.7% in hemolymph levels after exposure for 30 days to 1.00 mg/liter selenium. Selenium-induced changes in tissue ionic content (abdominal muscle and carapace) were most evident with respect to muscle levels of potassium and calcium. It is suggested that the observed alterations in fluid and tissue ionic content are largely in response to changes in concentration or electrochemical potential gradients brought about by selenium-induced disturbance of membrance permeability and ionic transport characteristics.

  15. Multiwall carbon nanotubes increase the microbial community in crude oil contaminated fresh water sediments.

    PubMed

    Abbasian, Firouz; Lockington, Robin; Palanisami, Thavamani; Megharaj, Mallavarapu; Naidu, Ravi

    2016-01-01

    Since crude oil contamination is one of the biggest environmental concerns, its removal from contaminated sites is of interest for both researchers and industries. In situ bioremediation is a promising technique for decreasing or even eliminating crude oil and hydrocarbon contamination. However, since these compounds are potentially toxic for many microorganisms, high loads of contamination can inhibit the microbial community and therefore reduce the removal rate. Therefore, any strategy with the ability to increase the microbial population in such circumstances can be of promise in improving the remediation process. In this study, multiwall carbon nanotubes were employed to support microbial growth in sediments contaminated with crude oil. Following spiking of fresh water sediments with different concentrations of crude oil alone and in a mixture with carbon nanotubes for 30days, the microbial profiles in these sediments were obtained using FLX-pyrosequencing. Next, the ratios of each member of the microbial population in these sediments were compared with those values in the untreated control sediment. This study showed that combination of crude oil and carbon nanotubes can increase the diversity of the total microbial population. Furthermore, these treatments could increase the ratios of several microorganisms that are known to be effective in the degradation of hydrocarbons.

  16. Chemical and histological studies of wild and hatchery salmon in fresh water

    USGS Publications Warehouse

    Wood, E.M.; Yasutake, W.T.; Halver, J.E.; Woodall, A.N.

    1960-01-01

    In a study of coho salmon (Oncorhynchus kisutch), the gross chemical and histological changes occurring over a 14-month period spent in fresh water were determined. The determinations were made at 3-month intervals on: 1) hatchery-reared fish, 2) fish hatchery-reared for 3, 6, 9, and 12 months and then planted in a controlled stream for the remainder of the period; and 3) an indigenous group of wild fish in this stream. Wild fish showed high incidence of tissue damage from spinose hairs of the moth larva, Halisidota argentata. Hatchery fish were similarly affected with the severity and incidence of lesions varying directly with the time of exposure of the larvae in the wild environment. Both groups of fish were heavily parasitized by sporozoan organisms in the kidney and spinal cord. Kidney disease appeared in both wild and planted hatchery fish. The gross chemical composition of hatchery fish transformed rapidly after planting to that of the wild fish. Although the initial rate of fat loss is essentially constant for all hatchery groups after planting, fish that were hatchery reared for 9 to 12 months did not complete the transformation to the wild-type body composition by the time of downstream migration at 14 months.

  17. Carbon sequestration capacity of sediments, algae, and zooplankton from fresh water aquaculture ponds.

    PubMed

    Anikuttan, K K; Adhikari, S; Kavitha, M; Jayasankar, P

    2016-07-01

    The contribution of aquaculture and allied activities to the emission of green house gases and consequently to global warming is an emerging concern among environmentalists in the recent past. However, there exists ample scope for aquaculture activities to sequester carbon and thus compensate for the carbon emissions linked to aquaculture. This article attempts to elucidate the carbon sequestration capacity of sediments, algae, and zooplankton from fresh water aquaculture ponds. The percent organic carbon in the pond sediments ranged from 0.39 to 1.31 with an average value of 0.912 ± 0.321 whereas the carbon sequestration capacity ranged from 0.442 to 1.882 MgC/ha (1 Mg = 10(6) g) with an average value of 1.018 ± 0.447 MgC/ha. In the case of zooplankton and algae from pond, the percent organic carbon was 7.688 ± 0.196 and 2.354 ± 0.047, respectively, whereas the total estimated carbon burial rate was 0.009 ± 0.005 and 0.150 ± 0.003 MgC/ha, respectively. These findings are discussed with the previous reports available at present and are found to be in comparable ranges. PMID:27321139

  18. Phytoavailability of heavy metals in tidal flat soils after fresh water leaching.

    PubMed

    Li, QuSheng; Chen, XiaoJiao; Luo, Xuan; Cui, ZhiHong; Shi, Lei; Wang, LiLi; Liu, YaNan

    2012-05-01

    The phytoavailability of Cd, Pb, Cr, Zn, Cu, and Ni, retained in tidal flat soil after fresh water leaching during reclamation was investigated. Two salt-tolerant varieties of tomato (Lycopersicon esculentum) and edible amaranth (Amaranthus mangostanus L.) were planted in soils having eight different desalination levels (from 6.7 to 1.4 g kg(-1) salinity) using pot experiments. Soil leaching significantly decreased the uptake of all metals by crop roots except for Ni. The reduction of soil salinity and exchangeable fraction content of Cd and Pb after leaching contributed to the decrease of uptake of metals by roots. All heavy metal concentrations in the edible parts of both crops in the two lowest salinity level treatments were lower than their maximum allowable levels in food. Results suggest that reclamation of tidal flats can reduce the phytoavailability of the heavy metals retained in soil. But the soil heavy metals may still pose health risks in the cultivation of root food crops.

  19. Antioxidant properties in some selected cyanobacteria isolated from fresh water bodies of Sri Lanka.

    PubMed

    Hossain, Md Fuad; Ratnayake, R R; Meerajini, Kirisnashamy; Wasantha Kumara, K L

    2016-09-01

    Phytonutrients and pigments present in cyanobacteria act as antioxidants, which facilitate the formation of body's defense mechanism against free radical damage to cells. The aim of this investigation was to study the total phenolic content (TPC), total flavonoid content (TFC), antioxidant activity, phycobiliproteins (PBPs), and active compounds in four cyanobacterial species, that is, Oscillatoria sp., Lyngbya sp., Microcystis sp., and Spirulina sp. isolated from fresh water bodies of Sri Lanka. In this study, Lyngbya sp., showed highest TPC (5.02 ± 0.20 mg/g), TFC (664.07 ± 19.76 mg/g), and total PBPs (127.01 mg/g) value. The ferric reducing antioxidant power (FRAP) was recorded highest in Oscillatoria sp. (39.63 ± 7.02), whereas the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity was also reported the highest in Oscillatoria sp. (465.31 ± 25.76) followed by Lyngbya sp. (248.39 ± 11.97). In FTIR spectroscopy, Lyngbya sp. does not show any N-H stretching band which is ultimately responsible for the inhibition of antioxidant activity. The study revealed that Lyngbya sp. and Oscillatoria sp. can be an excellent source for food, pharmaceutical, and other industrial uses. PMID:27625779

  20. Structural and optical characterization of fresh water diatoms (Cyclotella sp.): nature's nanoporous silica manufacturing plant

    NASA Astrophysics Data System (ADS)

    Mazumder, Nirmal; Gogoi, Ankur; Buragohain, Alak K.; Ahmed, Gazi A.; Choudhury, Amarjyoti

    2014-02-01

    Siliceous frustules were extracted from a representative fresh water diatom species (Cyclotella sp.) by treating with aqueous hydrochloric (HCl) acid. The structural characterizations of cleaned frustules were examined by scanning electron microscope (SEM). The microscopy images showed that the diatoms have a regular circular shape and are of almost equal size (average length is 9μm and average width is 3 μm). From energy dispersive X -ray spectroscopy (SEM-EDS) spot analysis it was confirmed that the frustules isolated from diatoms are composed mainly of silicon in the form of amorphous silica (SiO2). The bond information of chemical substances of diatom frustules was carried out at ambient temperature by means of Fourier Transform Infrared (FTIR) Spectroscopy. FTIR spectrum as recorded in transmittance mode showed the characteristic peaks for diatom biosilica, including for Si-O-Si stretching vibration at 1057 and 776 cm-1. Photoluminescence (PL) measurements of diatom frustules were performed at room temperature and it was observed that they emitted strong blue PL centered at 440nm when excited with ultraviolet (UV) radiation.

  1. NEURAL RECONNECTION IN THE TRANSECTED SPINAL CORD OF THE FRESH-WATER TURTLE Trachemys dorbignyi

    PubMed Central

    Rehermann, María Inés; Marichal, Nicolás; Russo, Raúl E.; Trujillo-Cenóz, Omar

    2009-01-01

    This paper provides the first evidence that fresh water turtles are able to reconnect their completely transected spinal cord leading to some degree of recovery of the motor functions lost after injury. Videographic analysis showed that some turtles (5 out of 11) surviving more than 20 days after injury were able to initiate stepping locomotion. However the stepping movements were slower than those of normal animals and swimming patterns were not restored. Even though just 45% of the injured turtles recovered their stepping patterns, all showed axonal sprouting beyond the lesion site. Immunocytochemical and electron microscope images revealed the occurrence of regrowing axons crossing the severed region. A major contingent of the axons reconnecting the cord originated from sensory neurons lying in dorsal ganglia adjacent to the lesion site. The axons bridging the damaged region traveled on a cellular scaffold consisting of BLBP and GFAP positive cells and processes. Serotonergic varicose nerve fibers and endings were found at early stages of the healing process at the epicenter of the lesion. Interestingly, the glial scar commonly found in the damaged central nervous system of mammals was absent. In contrast GFAP and BLBP positive processes were found running parallel to the main axis of the cord accompanying the crossing axons. PMID:19418545

  2. Non-thermal plasma-activated water inactivation of food-borne pathogen on fresh produce.

    PubMed

    Ma, Ruonan; Wang, Guomin; Tian, Ying; Wang, Kaile; Zhang, Jue; Fang, Jing

    2015-12-30

    Non-thermal plasma has been widely considered to be an effective method for decontamination of foods. Recently, numerous studies report that plasma-activated water (PAW) also has outstanding antibacterial ability. This study presents the first report on the potential of PAW for the inactivation of Staphylococcus aureus (S. aureus) inoculated on strawberries. PAW treatments achieved a reduction of S. aureus ranging from 1.6 to 2.3 log at day-0 storage, while 1.7 to 3.4 log at day-4 storage. The inactivation efficiency depended on the plasma-activated time for PAW generation and PAW-treated time of strawberries inoculated with S. aureus. LIVE/DEAD staining and scanning electron microscopy results confirm that PAW could damage the bacterial cell wall. Moreover, optical emission spectra and oxidation reduction potential results demonstrate the inactivation is mainly attributed to oxidative stress induced by reactive oxygen species in PAW. In addition, no significant change was found in color, firmness and pH of the PAW treated strawberries. Thus, PAW can be a promising alternative to traditional sanitizers applied in the fresh produce industry.

  3. Non-thermal plasma-activated water inactivation of food-borne pathogen on fresh produce.

    PubMed

    Ma, Ruonan; Wang, Guomin; Tian, Ying; Wang, Kaile; Zhang, Jue; Fang, Jing

    2015-12-30

    Non-thermal plasma has been widely considered to be an effective method for decontamination of foods. Recently, numerous studies report that plasma-activated water (PAW) also has outstanding antibacterial ability. This study presents the first report on the potential of PAW for the inactivation of Staphylococcus aureus (S. aureus) inoculated on strawberries. PAW treatments achieved a reduction of S. aureus ranging from 1.6 to 2.3 log at day-0 storage, while 1.7 to 3.4 log at day-4 storage. The inactivation efficiency depended on the plasma-activated time for PAW generation and PAW-treated time of strawberries inoculated with S. aureus. LIVE/DEAD staining and scanning electron microscopy results confirm that PAW could damage the bacterial cell wall. Moreover, optical emission spectra and oxidation reduction potential results demonstrate the inactivation is mainly attributed to oxidative stress induced by reactive oxygen species in PAW. In addition, no significant change was found in color, firmness and pH of the PAW treated strawberries. Thus, PAW can be a promising alternative to traditional sanitizers applied in the fresh produce industry. PMID:26282219

  4. Using Snow Fences to Augument Fresh Water Supplies in Shallow Arctic Lakes

    SciTech Connect

    Stuefer, Svetlana

    2013-03-31

    This project was funded by the U.S. Department of Energy, National Energy Technology Laboratory (NETL) to address environmental research questions specifically related to Alaska's oil and gas natural resources development. The focus of this project was on the environmental issues associated with allocation of water resources for construction of ice roads and ice pads. Earlier NETL projects showed that oil and gas exploration activities in the U.S. Arctic require large amounts of water for ice road and ice pad construction. Traditionally, lakes have been the source of freshwater for this purpose. The distinctive hydrological regime of northern lakes, caused by the presence of ice cover and permafrost, exerts influence on lake water availability in winter. Lakes are covered with ice from October to June, and there is often no water recharge of lakes until snowmelt in early June. After snowmelt, water volumes in the lakes decrease throughout the summer, when water loss due to evaporation is considerably greater than water gained from rainfall. This balance switches in August, when air temperature drops, evaporation decreases, and rain (or snow) is more likely to occur. Some of the summer surface storage deficit in the active layer and surface water bodies (lakes, ponds, wetlands) is recharged during this time. However, if the surface storage deficit is not replenished (for example, precipitation in the fall is low and near‐surface soils are dry), lake recharge is directly affected, and water availability for the following winter is reduced. In this study, we used snow fences to augment fresh water supplies in shallow arctic lakes despite unfavorable natural conditions. We implemented snow‐control practices to enhance snowdrift accumulation (greater snow water equivalent), which led to increased meltwater production and an extended melting season that resulted in lake recharge despite low precipitation during the years of the experiment. For three years (2009, 2010

  5. Fresh Water Generation from Aquifer-Pressured Carbon Storage: Interim Progress Report

    SciTech Connect

    Aines, R D; Wolery, T J; Hao, Y; Bourcier, W L

    2009-07-22

    This project is establishing the potential for using brine pressurized by Carbon Capture and Storage (CCS) operations in saline formations as the feedstock for desalination and water treatment technologies including nanofiltration (NF) and reverse osmosis (RO). The aquifer pressure resulting from the energy required to inject the carbon dioxide provides all or part of the inlet pressure for the desalination system. Residual brine would be reinjected into the formation at net volume reduction. This process provides additional storage space (capacity) in the aquifer, reduces operational risks by relieving overpressure in the aquifer, and provides a source of low-cost fresh water to offset costs or operational water needs. Computer modeling and laboratory-scale experimentation are being used to examine mineral scaling and osmotic pressure limitations for brines typical of CCS sites. Computer modeling is being used to evaluate processes in the aquifer, including the evolution of the pressure field. This progress report deals mainly with our geochemical modeling of high-salinity brines and covers the first six months of project execution (September, 2008 to March, 2009). Costs and implementation results will be presented in the annual report. The brines typical of sequestration sites can be several times more concentrated than seawater, requiring specialized modeling codes typical of those developed for nuclear waste disposal calculations. The osmotic pressure developed as the brines are concentrated is of particular concern, as are precipitates that can cause fouling of reverse osmosis membranes and other types of membranes (e.g., NF). We have now completed the development associated with tasks (1) and (2) of the work plan. We now have a contract with Perlorica, Inc., to provide support to the cost analysis and nanofiltration evaluation. We have also conducted several preliminary analyses of the pressure effect in the reservoir in order to confirm that reservoir

  6. Fresh-water lenses and practical limitations of their three-dimensional simulation

    NASA Astrophysics Data System (ADS)

    Ghassemi, F.; Alam, K.; Howard, K. W. F.

    2000-08-01

    Fresh-water lenses are the major sources of water supply in many atoll islands in the Pacific and Indian Oceans, particularly in dry seasons. Several two- and three-dimensional models are currently available for the simulation of atoll-island aquifers; however, 2D models cannot include 3D spatial variability of material properties, they must simplify the boundary conditions, and they cannot correctly simulate pumping wells. In an attempt to overcome these difficulties, a 3D model, SALTFLOW, was adopted for the simulation of Home Island in the Indian Ocean. This exercise required a discretisation on the order of a few metres and time steps of a few hours requiring significantly high CPU times. High CPU demand proved to be a difficult challenge but cannot be considered a serious practical limitation with today's advanced computers. The exhaustive data demands of the model (e.g., 3D distributions of hydraulic conductivity, porosity, dispersivities, and spatial and temporal variations of recharge and extraction rates) proved to be more problematical. Although the Home Island data set is unusually comprehensive by any standards, nonetheless the quality and quantity of the available data proved inadequate to meet the calibration needs of a highly karstic aquifer system. The Home Island modeling demonstrates the practical limitations of 3D models. It raises the concern that our ability to develop computer codes capable of simulating complex systems now exceeds our ability to supply the input data necessary for reliable calibration. Finally, the paper demonstrates the importance of the transient calibration in reliable simulation of various management options and emphasises that transient calibration should be considered as an integral part of any similar 2D or 3D modeling.

  7. Groundwater inflow measurements in wetland systems

    USGS Publications Warehouse

    Hunt, R.J.; Krabbenhoft, D.P.; Anderson, M.P.

    1996-01-01

    Our current understanding of wetlands is insufficient to assess the effects of past and future wetland loss. While knowledge of wetland hydrology is crucial, groundwater flows are often neglected or uncertain. In this paper, groundwater inflows were estimated in wetlands in southwestern Wisconsin using traditional Darcy's law calculations and three independent methods that included (1) stable isotope mass balances, (2) temperature profile modeling, and (3) numerical water balance modeling techniques. Inflows calculated using Darcy's law were lower than inflows estimated using the other approaches and ranged from 0.02 to (0.3 cm/d. Estimates obtained using the other methods generally were higher (0.1 to 1.1 cm/d) and showed similar spatial trends. An areal map of groundwater flux generated by the water balance model demonstrated that areas of both recharge and discharge exist in what is considered a regional discharge area. While each method has strengths and weaknesses, the use of more than one method can reduce uncertainty in the estimates.

  8. Floating brine crusts, reduction of evaporation and possible replacement of fresh water to control dust from Owens Lake bed, California

    NASA Astrophysics Data System (ADS)

    Groeneveld, D. P.; Huntington, J. L.; Barz, D. D.

    2010-10-01

    SummaryOwens Lake, California, a saline terminal lake desiccated after diversion of its water source, was formerly the single largest anthropogenic source of fugitive dust in North America. Over 100 billion m -3 yr -1 of fresh water are projected to be used for mandated dust control in over 100 km 2 of constructed basins required to be wetted to curtail emissions. An extensive evaporite deposit is located at the lake's topographic low and adjacent to the dust control basins. Because this deposit is non-dust-emissive, it was investigated as a potential replacement for the fresh water used in dust control. The deposit consists of precipitated layers of sodium carbonate and sulfate bathed by, and covered with brine dominated by sodium chloride perennially covered with floating salt crust. Evaporation ( E) rates through this crust were measured using a static chamber during the period of highest evaporative demand, late June and early July, 2009. Annualized total E from these measurements was significantly below average annual precipitation, thus ensuring that such salt deposits naturally remain wet throughout the year, despite the arid climate. Because it remains wetted, the evaporite deposit may therefore have the potential to replace fresh water to achieve dust control at near zero water use.

  9. The effect of soil water repellency on water and chemicals distribution in the soil profile for effluent and fresh water irrigation

    NASA Astrophysics Data System (ADS)

    Wallach, Rony; Rahav, Matan; Brindt, Naaran; Furman, Alex

    2015-04-01

    Water repellency (WR) has been reported for many vegetation types and soils and for effluent irrigation. Citrus trees have been found in a previous and in the current study to render sandy soils hydrophobic. The presented study focuses on the synergistic effect of the uneven wetting patterns and preferential flow pathways, known to occur in WR soils, and irrigation water quality on the spatial distribution of salinity and nutrients in the citrus trees' root zone. The study was performed in a commercial grapefruit orchard that is located at the coastal plain of Israel. The soil is sandy (80 % sand, 9 % silt and 11% clay). An experimental orchard area of 1500 m2 was divided into ten plots - five are irrigated with fresh water and five with secondary treated sewage water (effluent) using a drip irrigation system. Each plot contains 12 trees with spacing of 2x6 m. Soil texture, water repellency persistence (WDPT), and OM were measured for all 10 plots. The spatial and temporal water content distribution in the trees' root zone during and between subsequent irrigation events was measured undisturbedly by the electrical resistivity tomography (ERT) method. Soil water content within the root zone was indeed found highly heterogeneous in space and in time. Using ERT scans, two sites with relatively wet soil underneath and two with relatively dry soil underneath were chosen in each plot for further investigation. Disturbed soil samples from two depths, 0-20 and 20-40 cm, were taken from each site and tested in the laboratory for weight-based saturation, current water content, pH, EC, Cl, Na, Mg, NO3, P, K, and OM. The overall finding was that the uneven distribution of water content in the water repellent soil has a substantial effect on the salinity and nutrients distribution in the soil profile. Higher salinity and nutrients concentrations were found in the effluent irrigated plots compared to the fresh water plots. In particular, salinity was higher in the dry spots and

  10. Comparison of metal lability in air-dried and fresh dewatered drinking water treatment residuals.

    PubMed

    Wang, Changhui; Pei, Yuansheng; Zhao, Yaqian

    2015-01-01

    In this work, the labilities of Al, As, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Pb, Sr, V and Zn in air-dried (for 60 days) and fresh dewatered WTRs were compared using the Toxicity Characteristic Leaching Procedure (TCLP), fractionation, in vitro digestion and a plant enrichment test. The results showed that the air-dried and fresh dewatered WTRs had different properties, e.g., organic matter composition and available nutrients. The air-dried and fresh dewatered WTRs were non-haf zardous according to the TCLP assessment method used in the United States; however, the metals in the two types of WTRs had different lability. Compared with the metals in the fresh dewatered WTRs, those in the air-dried WTRs tended to be in more stable fractions and also exhibited lower bioaccessibility and bioavailability. Therefore, air-drying can decrease the metal lability and thereby reduce the potential metal pollution risk of WTRs.

  11. EFFICIENT RECOVERY OF ENTEROCOCCI FROM MARINE AND FRESH WATER BEACHES BY A 30,000 MOLECULAR WEIGHT CUTOFF HOLLOW FIBER ULTRAFILTER

    EPA Science Inventory

    Ultrafiltration systems have been used to concentrate pathogens from various types of fresh water samples. However, less work has been done with marine waters for the concentration of pathogens or indicator bacteria. An ultrafiltration approach to concentrate indicator bacteria...

  12. Disinfection potential of ozone, ultraviolet-C and their combination in wash water for the fresh-cut vegetable industry.

    PubMed

    Selma, María V; Allende, Ana; López-Gálvez, Francisco; Conesa, María A; Gil, María I

    2008-09-01

    The purpose of this research was to investigate the disinfection efficacy of ozone (O(3)) and UV-C illumination (UV), and their combination (O(3)-UV) for reducing microbial flora of fresh-cut onion, escarole, carrot, and spinach wash waters collected from the industry. Furthermore, the influence of water physicochemical parameters on the decontamination efficacy and the effect of these technologies on physicochemical quality of wash water were analyzed. O(3), UV, and O(3)-UV were effective disinfection treatments on vegetable wash water, with a maximum microbial reduction of 6.6 log CFU mL(-1) after 60 min treatment with O(3)-UV. However, maximum total microbial reductions achieved by UV and O(3) treatments after 60 min were 4.0 and 5.9 log CFU mL(-1), lower than by O(3)-UV treatment. Furthermore, turbidity of wash water was reduced significantly by O(3) and O(3)-UV treatments, while UV treatment did not affect the physicochemical quality of the water. Conclusions derived from this study illustrate that O(3) and O(3)-UV are alternatives to other sanitizers used in the fresh-cut washing processes. The use of these technologies would allow less frequent changing of spent water and the use of much lower sanitizer doses. Nevertheless, in specific applications such as carrot wash water, where levels of undesirable microbial and chemical constituents are lower than other vegetable wash water, UV treatment could be an appropriate treatment considering cost-effectiveness criteria.

  13. Biochemical composition of some small indigenous fresh water fishes from the River Mouri, Khulna, Bangladesh.

    PubMed

    Kamal, D; Khan, A N; Rahman, M A; Ahamed, F

    2007-05-01

    Biochemical composition of seven small indigenous fresh water fishes namely Magur (Clarias batrachus), Shingi (Heteropneustes fossilis), Koi (Anabas testudineus), Foli (Notopterus notopterus), Royna (Nandas nandas), Taki (Channa punctatus) and Tangra (Mystus vittatus) from the Mouri river Khulna, Bangladesh was studied in order to evaluate their nutritional values. The mean value of protein, fat, moisture and ash content was found as 14.87 +/- 0.63, 7.90 +/- 1.91, 73.49 +/- 0.69 and 3.74 +/- 0.46% in C. batrachus; 17.34 +/- 0.51, 3.45 +/- 0.92, 76.06 +/- 2.24 and 3.15 +/- 0.25% in H. fossilis; 19.63 +/- 0.5, 7.79 +/- 2.73, 69.27 +/- 1.04 and 3.31 +/- 0.83% in A. testudineus; 18.30 +/- 0.79, 4.98 +/- 1.71, 72.68 +/- 1.08 and 5.82 +/- 0.82% in N. notopterus; 16.09 +/- 2.66, 7.34 +/- 0.49, 75.75 +/- 0.78 and 5.19 +/- .029% in N. nandas; 19.13 +/- 2.40, 4.55 +/- 1.18, 70.55 +/- 1.89 and 6.81 +/- 0.94% in C. punctatus and 15.62 +/- 0.32, 7.53 +/- 1.10, 73.99 +/- 3.13 and 6.50 +/- 0.63% in M. vittatus. Considering the result of the present study, it can be concluded that all the species are rich in food value.

  14. Fresh water acclimation elicits a decrease in plasma corticosteroids in the euryhaline Atlantic stingray, Dasyatis sabina.

    PubMed

    Evans, Andrew N; Nunez, B Scott

    2015-10-01

    It is thought that the elasmobranch corticosteroid hormone 1α-hydroxycorticosterone (1α-B) functions as both a glucocorticoid (GC) and mineralocorticoid (MC). Classical antinatriuretic MC activities would run counter to the osmoregulatory strategy of euryhaline elasmobranchs acclimating to fresh water (FW). Therefore we hypothesize that FW acclimation will be accompanied by a decrease in plasma corticosteroids in these animals. However, events that activate the "fight-or-flight" response could mask changes associated with acclimation to lower salinities. To better define the MC role of corticosteroids in elasmobranchs, we designed a transfer system that allows the acclimation of Atlantic stingrays (Dasyatis sabina) from seawater (SW) to FW over 12h while minimizing other extraneous stressors. Blood and interrenal glands were sampled from one group of stingrays 24h after FW transfer, while another group was sampled two weeks after FW transfer. Two other groups served as mock-transfer controls in that they were treated and sampled in the same way, but remained in SW for the entire period. Plasma corticosteroids, osmolality, chloride, and urea were significantly lower in FW-acclimated stingrays (compared to mock-transfer stingrays) 24h after FW transfer. This pattern remained after two weeks in FW, with the exception that plasma corticosteroids returned to pre-acclimation levels. There were no significant differences between experimental groups in interrenal levels of mRNAs encoding key steroidogenic proteins (steroidogenic acute regulatory protein and cholesterol side chain cleavage enzyme). Temporally decreased corticosteroid levels during FW acclimation are consistent with the unique strategy of euryhaline elasmobranchs, whereby lower plasma osmolality is maintained in FW vs. SW environments to reduce hydromineral gradients. PMID:26315386

  15. Determination of trace vanadium (V) in seawater and fresh water by the catalytic kinetic spectrophotometric method

    NASA Astrophysics Data System (ADS)

    Ji, Hongwei; Sha, Yuanyuan; Xin, Huizhen; Li, Shuang

    2010-12-01

    A new kinetic spectrophotometric method has been developed for the determination of vanadium (V). The method is based on the catalytic effect of vanadium (V) on the oxidation of weak acid brilliant blue dye (RAWL) by KBrO3 using the citric acid as activation reagent. The obtained optimum conditions are: c (RAWL) = 1×10-4 molL-1, c (KBrO3) = 3×10-2 molL-1, c (citric acid) = 9×10-3 molL-1, pH = 2.50, the reaction time being 7.0 min and the temperature being 25.0°C. Under the optimum conditions, the proposed method allows the determination of vanadium (V) in the range of 0-70.0 ng mL-1 and the detection limit is down to 0.407 ng mL-1. For standard vanadium (V) solution determination, the recovery efficiency is in the range of 98.5%-102% and the RSD ranges from 0.76%-1.25%. Moreover, it is demonstrated that most cations and anions do not interfere with the determination of vanadium (V) under the analytical condition. The new method was successfully applied in the determination of vanadium (V) in fresh water and seawater samples with satisfactory results. Vanadium (V) in the seawater samples from Qingdao offshore was determined using the method and the distribution of vanadium (V) was mapped. Compared with other instrumental analytical methods, the proposed method shows good selectivity, sensitivity, simplicity, lower cost and rapidity. It can be employed on shipboard easily.

  16. Fresh water acclimation elicits a decrease in plasma corticosteroids in the euryhaline Atlantic stingray, Dasyatis sabina.

    PubMed

    Evans, Andrew N; Nunez, B Scott

    2015-10-01

    It is thought that the elasmobranch corticosteroid hormone 1α-hydroxycorticosterone (1α-B) functions as both a glucocorticoid (GC) and mineralocorticoid (MC). Classical antinatriuretic MC activities would run counter to the osmoregulatory strategy of euryhaline elasmobranchs acclimating to fresh water (FW). Therefore we hypothesize that FW acclimation will be accompanied by a decrease in plasma corticosteroids in these animals. However, events that activate the "fight-or-flight" response could mask changes associated with acclimation to lower salinities. To better define the MC role of corticosteroids in elasmobranchs, we designed a transfer system that allows the acclimation of Atlantic stingrays (Dasyatis sabina) from seawater (SW) to FW over 12h while minimizing other extraneous stressors. Blood and interrenal glands were sampled from one group of stingrays 24h after FW transfer, while another group was sampled two weeks after FW transfer. Two other groups served as mock-transfer controls in that they were treated and sampled in the same way, but remained in SW for the entire period. Plasma corticosteroids, osmolality, chloride, and urea were significantly lower in FW-acclimated stingrays (compared to mock-transfer stingrays) 24h after FW transfer. This pattern remained after two weeks in FW, with the exception that plasma corticosteroids returned to pre-acclimation levels. There were no significant differences between experimental groups in interrenal levels of mRNAs encoding key steroidogenic proteins (steroidogenic acute regulatory protein and cholesterol side chain cleavage enzyme). Temporally decreased corticosteroid levels during FW acclimation are consistent with the unique strategy of euryhaline elasmobranchs, whereby lower plasma osmolality is maintained in FW vs. SW environments to reduce hydromineral gradients.

  17. Water in barnacle muscle. III. NMR studies of fresh fibers and membrane-damaged fibers equilibrated with selected solutes.

    PubMed Central

    Burnell, E E; Clark, M E; Hinke, J A; Chapman, N R

    1981-01-01

    Water in barnacle muscle has been studied using NMR techniques. Fresh fibers are compared with membrane-damaged fibers treated with solutes that greatly alter fixed charge and total water content. Both water (97%) and solute (3%) protons are visible in continuous wave spectra of oriented fresh fibers. No local field inhomogeneities were detected, nor are cell solutes significantly bound. In pulse experiments, all cell water is visible and exhibits a single exponential decay. In fresh fibers, T2 approximately or equal to 40 ms; faster decaying signals are assigned to immobile and mobile protons on macromolecules. T1 and T1p are frequency dependent. Using equations derived for a two-compartment model with fast exchange, we calculate the following: tau b, the correlation time for anisotropic rotational motion of bound water; Sb, its order parameter; tau ex, the correlation time for exchange between bound and free fractions; f, the fraction of water bound; and Hr, the grams of water bound per gram of macromolecule. Whereas f varies inversely with total water content, the other parameters are virtually constant, with values: tau b approximately or equal to 1.3 X 10(-8) S; tau ex approximately or equal to 8 X 10(-6) s; Sb approximately or equal to 0.06; and Hr approximately or equal to 0.1g H2O/g macromolecule. Thus, the NMR relaxation detectable properties of water bound to macromolecules are unaffected by solutes that greatly alter the macromolecular surface charge. PMID:7272435

  18. Influence of conjunctive use of coffee effluent and fresh water on performance of robusta coffee and soil properties.

    PubMed

    Salakinkop, S R; Shivaprasad, P

    2012-01-01

    A field experiment was conducted to study the influence of treated coffee effluent irrigation on performance of established robusta coffee, nutrient contribution and microbial activities in the soil. The results revealed that the field irrigated with coffee effluent from aerobic tank having COD of 1009 ppm, did not affect the yield of clean coffee (1309 kg/ha) and it was statistically similar (on par) with the plots irrigated with fresh water (1310 kg/ha) with respect to clean coffee yield. Effluent irrigation increased significantly the population bacteria, yeast, fungi, actinomycetes and PSB (122, 52, 12, 34 and 6 x 104/g respectively)) in the soil compared to the soil irrigated with fresh water (87, 22, 5, 24 and 2 x 10(4)/g respectively). The organic carbon (2.60%), available nutrients in the soil like P (57.2 kg/ha), K (401.6 kg/ha, Ca (695.3 ppm), S (5.3 ppm),Cu (4.09 ppm) and Zn(4.78 ppm) were also increased due to effluent irrigation compared to fresh water irrigation. Thus analysis of coffee effluent for major and minor plant nutrients content revealed its potential as source of nutrients and water for plant growth.

  19. Adaptive patterns of osmotic and ionic regulation, and the invasion of fresh water by the palaemonid shrimps.

    PubMed

    Freire, Carolina A; Cavassin, Fabiola; Rodrigues, Ellen N; Torres, Antonio H; McNamara, John C

    2003-11-01

    To evaluate trends in the osmoregulatory behavior of neotropical, palaemonid shrimps, we investigated osmotic and ionic regulatory patterns in five species of Palaemon or Macrobrachium. The species' life histories depend on saline water to differing degrees, their habitats ranging from the marine/intertidal (P. northropi), through estuaries (P. pandaliformis) to coastal, freshwater streams (M. olfersii, M. potiuna) and inland, continental river systems (M. brasiliense). Hemolymph osmolality, chloride, sodium and magnesium concentrations were measured in shrimps exposed to experimental media ranging from fresh water (<0.5 per thousand ) to concentrated seawater (42 per thousand ) for up to 10 days. The marine and estuarine Palaemon species exhibit well-developed hyper/hypo-osmotic, sodium and chloride regulatory capabilities in mid-range salinities, tending to hyperconform in low salinities. The freshwater Macrobrachium species show variable hyperosmotic, sodium and chloride regulatory capacities, tending to hypoconform or unable to survive at higher salinities. All species hyper-regulate magnesium in fresh water, but hyporegulate strongly in saline media. Palaemonids from the saline habitats show the strongest osmoregulatory capabilities, and fresh water may have been gradually invaded by ancestral species with similar regulatory capacity. However, this regulatory plasticity has been lost to varying degrees in extant freshwater species.

  20. Assessment of the fresh-and brackish-water resources underlying Dunedin and adjacent areas on northern Pinellas County, Florida

    USGS Publications Warehouse

    Knochenmus, L.A.; Swenson, E.S.

    1996-01-01

    The city of Dunedin is enhancing their potable ground-water resources through desalination of brackish ground water. An assessment of the fresh- and brackish-water resources in the Upper Floridan aquifer was needed to estimate the changes that may result from brackish-water development. The complex hydrogeologic framework underlying Dunedin and adjacent areas of northern Pinellas County is conceptualized as a multilayered sequence of permeable zones and confining and semiconfining units. The permeable zones contain vertically spaced, discrete, water-producing zones with differing water quality. Water levels, water-level responses, and water quality are highly variable among the different permeable zones. The Upper Floridan aquifer is best characterized as a local flow system in most of northern Pinellas County. Pumping from the Dunedin well field is probably not influencing water levels in the aquifer outside Dunedin, but has resulted in localized depressions in the potentiometric surface surrounding production-well clusters. The complex geologic layering combined with the effects of production-well distribution probably contribute to the spatial and temporal variability in chloride concentrations in the Dunedin well field. Chloride concentrations in ground water underlying the Dunedin well field vary both vertically and laterally. In general, water-quality rapidly changes below depths of 400 feet below sea level. Additionally, randomly distributed water-producing zones with higher chloride concentrations may occur at shallow, discrete intervals above 400 feet. A relation between chloride concentration and distance from St. Joseph Sound is not apparent; however, a possible relation exists between chloride concentration and production-well density. Chloride-concentration data from production wells show a consistently increasing pattern that has accelerated since the late 1980's. Chloride-concentration data from 15 observation wells show increasing trends for 6 wells

  1. Application of electromagnetic propagation logging in the interpretation of fresh water neogene sands of upper Assam tertiary basin (India)

    NASA Astrophysics Data System (ADS)

    Handique, G. K.; Saikia, A. K.; Mallick, R. K.; Das, S. C.

    The EPT and ND overlay technique has been tried and found to be quite succesful in distinguishing between hydrocarbon and water zones in fresh water Tipam and Girujan sands, some of which could have been easily overlooked other wise, in a number of Upper Assam oilfields. The EPT-MSEL combination offers reliable values of m which could be utilized for estimation of more accurate values of water saturation. EPT measurement has also proved to be particularly useful in resolution of thin beds in the wells of Upper Assam basin.

  2. The Surface Water and Ocean Topography Mission: a mission concept to study the world's oceans and fresh water

    NASA Astrophysics Data System (ADS)

    Vaze, Parag; Albuys, Vincent; Esteban-Fernandez, Daniel; Lafon, Thierry; Lambin, Juliette; Mallet, Alain; Rodriguez, Ernesto

    2010-10-01

    The Surface Water and Ocean Topography (SWOT) is a planned satellite mission to study the world's oceans and terrestrial surface water bodies. The SWOT mission concept has been proposed jointly by the global Hydrology and Oceanography science communities to make the first global survey of the Earth's surface water, observe the fine details of the ocean's surface topography, and measure how water bodies change over time. SWOT was one of 15 missions listed in the 2007 National Research Council's Decadal Survey for Earth science as a mission that NASA should implement in the incoming decade. This mission concept builds upon the heritage of prior missions and technologies such as Topex/Poseidon, Jason-1/ 2, the Shuttle Radar Topography Mission (SRTM), and the initial development of the Wide Swatch Ocean Altimeter intended for the Ocean Surface Topography Mission/Jason-2. The key measurement capability for SWOT is provided by a Ka-band synthetic aperture radar interferometer (KaRIn). With an orbit altitude of 970 km, the KaRIn instrument provides a high-resolution swath width of 120 km enabling global coverage (~90%) of the world's ocean's and fresh water bodies. The KaRIn measurement is being designed to provide a spatial resolution of 1 km for the oceans (after on-board processing), and 100 m for land water, both at centimetric accuracy. An additional instrument suite similar to the Jason series will complement KaRIn: a Ku-band nadir altimeter, a Microwave Radiometer and Precision Orbit Determination (POD) systems. To enable this challenging measurement performance, the SWOT mission concept is designed to overcome several challenges, such as very high raw data rate (320 Mbps), large on-board data volumes, high power demand, stringent pointing and stability requirements, and ground data processing systems, to produce meaningful science data products to our user community. The SWOT mission concept is being developed as a cooperative effort between NASA and CNES. This

  3. Effects of organic and inorganic lead on the oxygen equilibrium curves of the fresh water field crab, Barytelphusa guerini

    SciTech Connect

    Tulasi, S.J.; Ramana Rao, J.V.

    1989-02-01

    Haemocyanin serves as normal transporter of oxygen in many Arthropods. The oxygen equilibrium curves have been described for the haemocyanins of many Arthropods and Molluscs. Oxygen equilibrium curves of the blood reveal the relationship between the oxygen tension and the percentage saturation of the haemocyanin. The shape of the oxygen equilibrium curves vary in position from sigmoid to hyperbolic in different animals or even undulatory as shown in some chitons. Oxygen equilibrium curves are known to be influenced by pH, temperature and inorganic ions. The effect of environmental pollutants like the heavy metals on the oxygen equilibrium curves of the fresh water crab has not been previously reported. One of the toxic heavy metals with regard to aquatic organisms is lead. Hence the present study was designed to determine the effect of organic and inorganic lead on the oxygen equilibrium curve of the fresh water crab, Barytelphusa guerini.

  4. SEQUESTERING AGENTS FOR METAL IMMOBILIZATION APPLICATION TO THE DEVELOPMENT OF ACTIVE CAPS IN FRESH AND SALT WATER SEDIMENTS

    SciTech Connect

    Knox, A; Michael Paller, M

    2006-11-17

    This research evaluated the removal of inorganic contaminants by a variety of amendments and mixtures of amendments in fresh and salt water. A series of removal and retention batch experiments was conducted to identify the best treatment for metal removal. Metal removal by the amendments was evaluated by calculating the partition coefficient and percent removal. Retention of metals by the amendments was evaluated in retention (desorption) studies in which residue from the removal studies was extracted with 1 M MgCl{sub 2} solution. The results indicated that phosphate amendments, some organoclays (e.g., OCB-750), and the biopolymer, chitosan, are very effective in removal and retention of metals in both fresh and salt water. These amendments are being evaluated further as components in the development of active caps for sediment remediation.

  5. Design of a proteus lattice representative of a burnt and fresh fuel interface at power conditions in light water reactors

    SciTech Connect

    Hursin, M.; Perret, G.

    2012-07-01

    The research program LIFE (Large-scale Irradiated Fuel Experiment) between PSI and Swissnuclear has been started in 2006 to study the interaction between large sets of burnt and fresh fuel pins in conditions representative of power light water reactors. Reactor physics parameters such as flux ratios and reaction rate distributions ({sup 235}U and {sup 238}U fissions and {sup 238}U capture) are calculated to estimate an appropriate arrangement of burnt and fresh fuel pins within the central element of the test zone of the zero-power research reactor PROTEUS. The arrangement should minimize the number of burnt fuel pins to ease fuel handling and reduce costs, whilst guaranteeing that the neutron spectrum in both burnt and fresh fuel regions and at their interface is representative of a large uniform array of burnt and fresh pins in the same moderation conditions. First results are encouraging, showing that the burnt/fresh fuel interface is well represented with a 6 x 6 bundle of burnt pins. The second part of the project involves the use of TSUNAMI, CASMO-4E and DAKOTA to perform parametric and optimization studies on the PROTEUS lattice by varying its pitch (P) and fraction of D{sub 2}O in moderator (F{sub D2O}) to be as representative as possible of a power light water reactor core at hot full power conditions at beginning of cycle (BOC). The parameters P and F{sub D2O} that best represent a PWR at BOC are 1.36 cm and 5% respectively. (authors)

  6. Dietary sodium requirement determined for juvenile hybrid tilapia (Oreochromis niloticus x O. aureus) reared in fresh water and seawater.

    PubMed

    Shiau, Shi-Yen; Lu, Li-Shan

    2004-04-01

    Two 8-week feeding trials were conducted to determine the dietary Na requirement for juvenile hybrid tilapia (Oreochromis niloticus x O. aureus) reared in fresh water and seawater. In each experiment, NaCl was added to the basal diet at 0, 0.5, 1, 2, 3, 5, or 7 g Na/kg diet (fresh water) and at 0, 0.2, 0.5, 0.8, 1.2, 1.5, 2, or 3 g Na/kg diet (seawater). Each diet was fed to three replicate groups of fish, individual fish initially weighing 0.69 (se 0.01) g, in a closed, recirculating rearing system. In fresh water, the tilapia fed the diet supplemented with 2 g Na/kg diet had significantly (P<0.05) greater weight gain than the fish fed the diets supplemented with >/=3 and fresh water, indicated that the adequate dietary Na concentration for tilapia is about 1.5 g/kg diet. The present study also suggests that no dietary Na is required for tilapia reared in seawater.

  7. Acidic Electrolyzed Water as a Novel Transmitting Medium for High Hydrostatic Pressure Reduction of Bacterial Loads on Shelled Fresh Shrimp.

    PubMed

    Du, Suping; Zhang, Zhaohuan; Xiao, Lili; Lou, Yang; Pan, Yingjie; Zhao, Yong

    2016-01-01

    Acidic electrolyzed water (AEW), a novel non-thermal sterilization technology, is widely used in the food industry. In this study, we firstly investigated the effect of AEW as a new pressure transmitting medium for high hydrostatic pressure (AEW-HHP) processing on microorganisms inactivation on shelled fresh shrimp. The optimal conditions of AEW-HHP for Vibrio parahaemolyticus inactivation on sterile shelled fresh shrimp were obtained using response surface methodology: NaCl concentration to electrolysis 1.5 g/L, treatment pressure 400 MPa, treatment time 10 min. Under the optimal conditions mentioned above, AEW dramatically enhanced the efficiency of HHP for inactivating V. parahaemolyticus and Listeria monocytogenes on artificially contaminated shelled fresh shrimp, and the log reductions were up to 6.08 and 5.71 log10 CFU/g respectively, while the common HHP could only inactivate the two pathogens up to 4.74 and 4.31 log10 CFU/g respectively. Meanwhile, scanning electron microscopy (SEM) showed the same phenomenon. For the naturally contaminated shelled fresh shrimp, AEW-HHP could also significantly reduce the micro flora when examined using plate count and PCR-DGGE. There were also no significant changes, histologically, in the muscle tissues of shrimps undergoing the AEW-HHP treatment. In summary, using AEW as a new transmitting medium for HHP processing is an innovative non thermal technology for improving the food safety of shrimp and other aquatic products.

  8. Acidic Electrolyzed Water as a Novel Transmitting Medium for High Hydrostatic Pressure Reduction of Bacterial Loads on Shelled Fresh Shrimp

    PubMed Central

    Du, Suping; Zhang, Zhaohuan; Xiao, Lili; Lou, Yang; Pan, Yingjie; Zhao, Yong

    2016-01-01

    Acidic electrolyzed water (AEW), a novel non-thermal sterilization technology, is widely used in the food industry. In this study, we firstly investigated the effect of AEW as a new pressure transmitting medium for high hydrostatic pressure (AEW-HHP) processing on microorganisms inactivation on shelled fresh shrimp. The optimal conditions of AEW-HHP for Vibrio parahaemolyticus inactivation on sterile shelled fresh shrimp were obtained using response surface methodology: NaCl concentration to electrolysis 1.5 g/L, treatment pressure 400 MPa, treatment time 10 min. Under the optimal conditions mentioned above, AEW dramatically enhanced the efficiency of HHP for inactivating V. parahaemolyticus and Listeria monocytogenes on artificially contaminated shelled fresh shrimp, and the log reductions were up to 6.08 and 5.71 log10 CFU/g respectively, while the common HHP could only inactivate the two pathogens up to 4.74 and 4.31 log10 CFU/g respectively. Meanwhile, scanning electron microscopy (SEM) showed the same phenomenon. For the naturally contaminated shelled fresh shrimp, AEW-HHP could also significantly reduce the micro flora when examined using plate count and PCR-DGGE. There were also no significant changes, histologically, in the muscle tissues of shrimps undergoing the AEW-HHP treatment. In summary, using AEW as a new transmitting medium for HHP processing is an innovative non thermal technology for improving the food safety of shrimp and other aquatic products. PMID:27014228

  9. Effect of legume seed extracts on the inhibition of proteolytic activity and muscle degradation of fresh water prawn (Macrobrachiumrosenbergii).

    PubMed

    Sriket, Chodsana; Benjakul, Soottawat; Visessanguan, Wonnop; Hara, Kenji

    2011-12-01

    Trypsin inhibitors in the extracts from soybean (Glycine max), adzuki bean (Vigna angularis), bambara groundnut (Vigna subterranea) and red kidney bean (Phaseoulus vulgaris) varied in amount and molecular weight. The soybean extract had the highest level of trypsin inhibitor with molecular weight (MW) of 21kDa, followed by bambara groundnut extract possessing trypsin inhibitor with MW of 15kDa. Both extracts showed a more effective inhibition towards crude protease extract (CE) from the hepatopancreas of fresh water prawn (Macrobrachium rosenbergii) than the extracts from adzuki and red kidney beans. Activity staining also reconfirmed the higher inhibitory activity on CE from hepatopancreas by the extracts from both soybean and bambara groundnut. The extracts from all seeds were able to inhibit the degradation of fresh water prawn meat containing CE in a concentration dependent manner. Based on inhibitor study, the extracts from soybean and bambara groundnut can be a potential aid to suppress the muscle softening of fresh water prawn, mediated by trypsin-like proteases released from hepatopancreas, during extended iced storage.

  10. Effect of legume seed extracts on the inhibition of proteolytic activity and muscle degradation of fresh water prawn (Macrobrachiumrosenbergii).

    PubMed

    Sriket, Chodsana; Benjakul, Soottawat; Visessanguan, Wonnop; Hara, Kenji

    2011-12-01

    Trypsin inhibitors in the extracts from soybean (Glycine max), adzuki bean (Vigna angularis), bambara groundnut (Vigna subterranea) and red kidney bean (Phaseoulus vulgaris) varied in amount and molecular weight. The soybean extract had the highest level of trypsin inhibitor with molecular weight (MW) of 21kDa, followed by bambara groundnut extract possessing trypsin inhibitor with MW of 15kDa. Both extracts showed a more effective inhibition towards crude protease extract (CE) from the hepatopancreas of fresh water prawn (Macrobrachium rosenbergii) than the extracts from adzuki and red kidney beans. Activity staining also reconfirmed the higher inhibitory activity on CE from hepatopancreas by the extracts from both soybean and bambara groundnut. The extracts from all seeds were able to inhibit the degradation of fresh water prawn meat containing CE in a concentration dependent manner. Based on inhibitor study, the extracts from soybean and bambara groundnut can be a potential aid to suppress the muscle softening of fresh water prawn, mediated by trypsin-like proteases released from hepatopancreas, during extended iced storage. PMID:25212342

  11. Spatial and overwinter changes in clam populations of San Pablo Bay, a semiarid estuary with highly variable freshwater inflow

    USGS Publications Warehouse

    Poulton, V.K.; Lovvorn, J.R.; Takekawa, J.Y.

    2004-01-01

    In many estuaries worldwide, climate trends together with human diversion of fresh water have dramatically impacted the benthos. Such impacts have sometimes been complicated by exotic species, whose invasion and persistence can be mediated by wide variations in freshwater inflow. Monitoring such changes usually involves periodic samples at a few sites; but sampling that does not recognize variation at a range of spatial and seasonal scales may not reveal important benthic trends. San Pablo Bay, in northern San Francisco Bay, has extreme fluctuations in freshwater inflow. This bay also experienced a major benthic change with introduction of the Asian clam (Potamocorbula amurensis) in 1986. This species initially displaced the former community, but later appeared to vary in abundance depending on site and freshwater inflow. To investigate such patterns and provide guidelines for research and monitoring, we took 1746 core samples at six sites around San Pablo Bay from 19 October to 17 December 1999 and from 6 March to 19 April 2000. Most biomass consisted of the clams P. amurensis,Macoma balthica and Mya arenaria. Potamocorbula amurensis dominated the benthos at most sites in the fall and recruited a new cohort during winter, while there was weak recruitment in M. balthica and none in M. arenaria. At most but not all sites, densities of P. amurensis and M. arenaria declined dramatically over winter while M. balthica declined only slightly. The dominant clams had patch diameters >5 m at most but not all sites, and some showed inconsistent patch structure at scales of 100–1400 m. In this semiarid estuary with highly variable freshwater inflow, samples for research and monitoring should include multiple sites and seasons, and samples within sites should be ≥5 m apart to account for between-patch variation. Species abundance in winter 1999–2000 appeared to be affected by high freshwater inflows in 1997–1999, while spatial patterns were probably most affected by

  12. Management of fresh water weeds (macrophytes) by vermicomposting using Eisenia fetida.

    PubMed

    Najar, Ishtiyaq Ahmed; Khan, Anisa B

    2013-09-01

    In the present study, potential of Eisenia fetida to recycle the different types of fresh water weeds (macrophytes) used as substrate in different reactors (Azolla pinnata reactor, Trapa natans reactor, Ceratophyllum demersum reactor, free-floating macrophytes mixture reactor, and submerged macrophytes mixture reactor) during 2 months experiment is investigated. E. fetida showed significant variation in number and weight among the reactors and during the different fortnights (P <0.05) with maximum in A. pinnata reactor (number 343.3 ± 10.23 %; weight 98.62 ± 4.23 % ) and minimum in submerged macrophytes mixture reactor (number 105 ± 5.77 %; weight 41.07 ± 3.97 % ). ANOVA showed significant variation in cocoon production (F4 = 15.67, P <0.05) and mean body weight (F4 = 13.49, P <0.05) among different reactors whereas growth rate (F3 = 23.62, P <0.05) and relative growth rate (F3 = 4.91, P <0.05) exhibited significant variation during different fortnights. Reactors showed significant variation (P <0.05) in pH, Electrical conductivity (EC), Organic carbon (OC), Organic nitrogen (ON), and C/N ratio during different fortnights with increase in pH, EC, N, and K whereas decrease in OC and C/N ratio. Hierarchical cluster analysis grouped five substrates (weeds) into three clusters-poor vermicompost substrates, moderate vermicompost substrate, and excellent vermicompost substrate. Two principal components (PCs) have been identified by factor analysis with a cumulative variance of 90.43 %. PC1 accounts for 47.17 % of the total variance represents "reproduction factor" and PC2 explaining 43.26 % variance representing "growth factor." Thus, the nature of macrophyte affects the growth and reproduction pattern of E. fetida among the different reactors, further the addition of A. pinnata in other macrophytes reactors can improve their recycling by E. fetida.

  13. Contrasting patterns in genetic diversity following multiple invasions of fresh and brackish waters.

    PubMed

    Kelly, David W; Muirhead, James R; Heath, Daniel D; Macisaac, Hugh J

    2006-10-01

    of the two invading clades were found principally at recently invaded fresh and brackish water sites in Eastern Europe, and were characterized by higher genetic diversity than putative source populations. Further studies are required to determine if these represent novel genotypes. Our results confirm that biological invasions need not result in diminished genetic diversity, particularly if multiple source populations, each with distinctive genetic composition, contribute to the founding populations. PMID:17032263

  14. Estimation of the depth to the fresh-water/salt-water interface from vertical head gradients in wells in coastal and island aquifers

    USGS Publications Warehouse

    Izuka, S.K.; Gingerich, S.B.

    1998-01-01

    An accurate estimate of the depth to the theoretical interface between fresh, water and salt water is critical to estimates of well yields in coastal and island aquifers. The Ghyben-Herzberg relation, which is commonly used to estimate interface depth, can greatly underestimate or overestimate the fresh-water thickness, because it assumes no vertical head gradients and no vertical flow. Estimation of the interface depth needs to consider the vertical head gradients and aquifer anisotropy that may be present. This paper presents a method to calculate vertical head gradients using water-level measurements made during drilling of a partially penetrating well; the gradient is then used to estimate interface depth. Application of the method to a numerically simulated fresh-water/salt-water system shows that the method is most accurate when the gradient is measured in a deeply penetrating well. Even using a shallow well, the method more accurately estimates the interface position than does the Ghyben-Herzberg relation where substantial vertical head gradients exist. Application of the method to field data shows that drilling, collection methods of water-level data, and aquifer inhomogeneities can cause difficulties, but the effects of these difficulties can be minimized.

  15. Antimicrobial Activities and Water Vapor Barrier of Starch-Lipid Based Edible Coatings on Fresh Produce

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The uses of edible antimicrobial films or coatings have been proven to be a novel way of suppressing pathogen contaminations of fresh foods where physical barriers alone aren’t enough. In the present study, we embedded essential oils into a proprietary starch-lipids composite, called Fantesk, to in...

  16. Determination of naturally-occurring actinides and their progeny in fresh water using ICP-MS and batch separation

    SciTech Connect

    Crain, J.S.; Alvarado, J.A.; Kiely, J.T.

    1995-12-01

    The determination of naturally-occurring actinides (including progeny such as {sup 230}Th) in fresh water is of significance in limnology, hydrology, and environmental monitoring. In many instances, these determinations require multiple analyses and a combination of radiometric and elemental measurement techniques (e.g., alpha spectrometry and thermal ionization mass spectrometry). In this work, we will describe the use of a single technique, inductively coupled plasma-mass spectrometry (ICP-MS), for these determinations. We will also describe the batch separation chemistry used to facilitate these determinations in ground and surface water, where natural analyte concentrations run between 1 {mu}g/L and 1 {mu}g/L.

  17. Effect of Water Stress and Storage Time on Anthocyanins and Other Phenolics of Different Genotypes of Fresh Sweet Basil.

    PubMed

    Luna, María C; Bekhradi, Farzaneh; Ferreres, Federico; Jordán, María J; Delshad, Mojtaba; Gil, María I

    2015-10-28

    This study describes the effect of water stress and storage time on the content of anthocyanins and other phenolics in different genotypes of fresh sweet basil (Ocimum basilicum L.). Purple and green Iranian cultivars and a Genovese variety were exposed to a control (100% of the field capacity, FC) and to water stress of mild and severe deficit irrigation treatments (25 and 50 DI corresponding to 75 and 50% FC, respectively). The individual characterization by HPLC-DAD-ESI/MS(n) and the MS fragmentation pathway of anthocyanins are described. A 50% increase in the anthocyanin content was observed in 50 DI after storage. Water stress markedly enhanced the content of phenolic acids after storage in the three genotypes. Water stress can be an efficient way to help the sustainability of water resources, enriching the content of phenolic compounds that may be beneficial to human health.

  18. Effect of Water Stress and Storage Time on Anthocyanins and Other Phenolics of Different Genotypes of Fresh Sweet Basil.

    PubMed

    Luna, María C; Bekhradi, Farzaneh; Ferreres, Federico; Jordán, María J; Delshad, Mojtaba; Gil, María I

    2015-10-28

    This study describes the effect of water stress and storage time on the content of anthocyanins and other phenolics in different genotypes of fresh sweet basil (Ocimum basilicum L.). Purple and green Iranian cultivars and a Genovese variety were exposed to a control (100% of the field capacity, FC) and to water stress of mild and severe deficit irrigation treatments (25 and 50 DI corresponding to 75 and 50% FC, respectively). The individual characterization by HPLC-DAD-ESI/MS(n) and the MS fragmentation pathway of anthocyanins are described. A 50% increase in the anthocyanin content was observed in 50 DI after storage. Water stress markedly enhanced the content of phenolic acids after storage in the three genotypes. Water stress can be an efficient way to help the sustainability of water resources, enriching the content of phenolic compounds that may be beneficial to human health. PMID:26473474

  19. The distribution of submersed aquatic vegetation and water lettuce in the fresh and oligohaline tidal Potomac River, 2007

    USGS Publications Warehouse

    Campbell, Sarah Hunter; Rybicki, Nancy B.; Schenk, Edward R.

    2015-01-01

    Surveys documenting the composition of species of submersed aquatic vegetation (SAV) have been conducted in the Potomac River for decades. These surveys can help managers assess the proportion of native and exotic plants in the river or can be used to determine relationships between native and exotic plants, environmental conditions, and wildlife. SAV coverage increased from 2005 to 2007 throughout the fresh and oligohaline study area. The 2007 survey documented here determined that eleven species of SAV were present. The abundance of the exotic species Hydrilla verticillata (hydrilla) was relatively low, and species diversity was relatively high compared to previous years. The survey also revealed a new population of the invasive, floating aquatic plant Pistia stratiotes (water lettuce). In 2007, water lettuce, the latest exotic aquatic plant to be found in the fresh to oligohaline portion of the Potomac River, was most abundant in Mattawoman Creek, Charles County, Maryland. However, it was not observed in the fresh to oligohaline portion of the Potomac River in the summer of 2008. An understanding of the distribution of SAV species and factors governing the abundance of native and invasive aquatic species is enhanced by long-term surveys.

  20. Variation in Lateral Plate Quality in Threespine Stickleback from Fresh, Brackish and Marine Water: A Micro-Computed Tomography Study

    PubMed Central

    Reseland, Janne E.; Østbye, Kjartan; Haugen, Håvard J.; Vøllestad, Leif A.

    2016-01-01

    Introduction It is important to understand the drivers leading to adaptive phenotypic diversity within and among species. The threespine stickleback (Gasterosteus aculeatus) has become a model system for investigating the genetic and phenotypic responses during repeated colonization of fresh waters from the original marine habitat. During the freshwater colonization process there has been a recurrent and parallel reduction in the number of lateral bone plates, making it a suitable system for studying adaptability and parallel evolution. Objective The aim of this study was to investigate an alternative evolutionary path of lateral plate reduction, where lateral plates are reduced in size rather than number. Materials and Methods A total of 72 threespine stickleback individuals from freshwater (n = 54), brackish water (n = 27) and marine water (n = 9) were analysed using microcomputed tomography (μCT) to determine variation in size, thickness and structure of the lateral plates. Furthermore, whole-body bone volume, and bone volume, bone surface and porosity of lateral plate number 4 were quantified in all specimens from each environment. Results The results showed a significant difference in plate size (area and volume) among populations, where threespine stickleback from polymorphic freshwater and brackish water populations displayed lateral plates reduced in size (area and volume) compared to marine stickleback Conclusions Reduction of lateral plates in threespine stickleback in fresh and brackish water occurs by both plate loss and reduction in plate size (area and volume). PMID:27764140

  1. Dynamics of the iodine-goitrogen balance in the thyroid status of catfish from selected fresh and brackish water bodies.

    PubMed

    Akindahunsi, A A; Salawu, S O; Adu, O C

    2004-01-01

    The study was designed to investigate the dynamics of the goitrogen-iodine balance in Igbokoda brackish and Ogbese fresh water bodies in Ondo State, Nigeria. The parameters determined include iodine, thiocyanate, chloride, nitrate, calcium, magnesium hardness, calcium hardness, total hardness, and total coliform counts in water, sediment and/or fish (flesh and serum). The fish were subjected to a number of treatments (boiling with water or sodium chloride solution, frying or roasting) prior to analysis. The iodine level (microg I/100g) in the flesh of fish varied with size, treatment and location; it increased with size, was reduced by some treatments (boiling with either water or NaCl solution), while frying and roasting did not affect the level. The least values were 93.45 (Ogbese fish boiled with NaCl solution) and 160.94 (Igbokoda fish boiled with either water or NaCl solution). On the whole, Igbokoda (160.94-314.08) had higher values than Ogbese (93.45-205.06). Serum iodine (microg I/100mL) was equally higher in Igbokoda (5.00-9.00) compared to Ogbese (2.80-5.00). Only the large sized fish of Ogbese recorded a value of 5.00 micromol/L for thiocyanate while this parameter was not detected in other samples. The calculated I/goitrogen ratios (I/Ca, I/NO3, I/Cl and I/SCN) were higher for Igbokoda water than Ogbese water with the exception of I/Mg. This was equally reinforced by the total count of coliforms (goitrogenic), which was higher in Ogbese (3.0 x 10(3)) than in Igbokoda (2.7 x 10(3)). These results indicate that the Igbokoda brackish water body would be a better source of iodine than Ogbese fresh water body for the population dependent on them. PMID:15174737

  2. Global Anthropogenic Phosphorus Loads to Fresh Water, Grey Water Footprint and Water Pollution Levels: A High-Resolution Global Study

    NASA Astrophysics Data System (ADS)

    Mekonnen, M. M.; Hoekstra, A. Y. Y.

    2014-12-01

    We estimated anthropogenic phosphorus (P) loads to freshwater, globally at a spatial resolution level of 5 by 5 arc minute. The global anthropogenic P load to freshwater systems from both diffuse and point sources in the period 2002-2010 was 1.5 million tonnes per year. China contributed about 30% to this global anthropogenic P load. India was the second largest contributor (8%), followed by the USA (7%), Spain and Brazil each contributing 6% to the total. The domestic sector contributed the largest share (54%) to this total followed by agriculture (38%) and industry (8%). Among the crops, production of cereals had the largest contribution to the P loads (32%), followed by fruits, vegetables, and oil crops, each contributing about 15% to the total. We also calculated the resultant grey water footprints, and relate the grey water footprints per river basin to runoff to calculate the P-related water pollution level (WPL) per catchment.

  3. Taphonomy of deciduous leaves and changes in the d13C signal after deposition in fresh water settings

    NASA Astrophysics Data System (ADS)

    Reimann, Simon; Roth-Nebelsick, Anita; Nebelsick, James; Grein, Michaela

    2016-04-01

    Carbon isotopic signals from fossil plant material are an important source of information for palaeoecology and palaeoclimatology. Usually, the 13C isotope is depleted in plant material, compared to the atmospheric 13C content, because 13C is discriminated against 12C during the process of photosynthesis. The degree of 13C discrimination depends on the photosynthetic pathway (C3, C4 and CAM) and is substantially affected by environmental factors (for example, water stress). Various plant material components, however, differ also with respect to their 13C content. It is generally assumed that the d13C signal found in fossil plants reflects that of the living plant to a sufficient degree. Obtaining information on possible alterations during the taphonomic process is, however, desirable. In this study, changes in d13C of deciduous leaves are monitored, from the living leaf still attached to the tree to leaves deposited in fresh water setting for one or more years, thus focusing on early stages of taphonomy. The considered taxa are species from Quercus (oak) and Fagus (beech). Deposited leaves from three fresh water environments in Southwestern Germany were studied: active stream in a forest, still water pond in a forest, and a waterlogged moor environment. Additionally to the isotope measurements, the degree of leaf tissue degradation and colonization with degrading organisms were observed with Scanning Electron Microscopy.

  4. The Mysidae (Crustacea: Peracarida: Mysida) in fresh and oligohaline waters of the Mediterranean. Taxonomy, biogeography, and bioinvasion.

    PubMed

    Wittmann, Karl J; Ariani, Antonio P; Daneliya, Mikhail

    2016-01-01

    A census of Mysidae yielded a total of twelve species plus two non-nominotypical subspecies found so far in fresh and oligohaline waters of the Mediterranean, all belonging to the subfamily Mysinae. Among the nine species in fresh-waters, three are stenoendemics, namely of a single lake (Diamysis lacustris), of two neighbouring river systems (Paramysis kosswigi) or of karstic cave waters (Troglomysis vjetrenicensis). Four species-T. vjetrenicensis, D. lacustris, D. fluviatilis, and Paramysis adriatica sp. nov. described in this paper-are confined to freshwater tributaries of the Adriatic Sea (NE-Mediterranean). This strengthens previous findings about the outstanding role of the Adriatic basin for the endemic diversity of freshwater Mysidae within the Mediterranean. This is possibly related to alternating marine and freshwater-terrestrial phases during the Pliocene-Pleistocene in this semi-enclosed basin. Based on current knowledge, freshwater populations of D. mesohalobia heterandra are also confined to the Adriatic basin; this taxon, however, shows many more populations in brackish waters of the E-Mediterranean and Marmora basins. Two freshwater species (Limnomysis benedeni, Hemimysis anomala) are wide-range invaders of Ponto-Caspian origin, with recent expansion into fresh and brackish waters of the NW-Mediterranean. A further immigrant to this part of the Mediterranean, Neomysis integer, is of NE-Atlantic origin and occurs only marginally in fresh-water.        Five among the nine species found at least once in fresh-water were also reported in oligohaline conditions, mostly also at even higher salinities. A total of eight species plus two subspecies were recorded in oligohaline waters (S = 0.5-5). Among these, only one oligohalobious stenoendemic, Diamysis hebraica, inhabits streams at the Levantine coast.        In the historical biogeographical context, the current distribution of only one out of nine indigenous species in an- to oligohaline

  5. The Mysidae (Crustacea: Peracarida: Mysida) in fresh and oligohaline waters of the Mediterranean. Taxonomy, biogeography, and bioinvasion.

    PubMed

    Wittmann, Karl J; Ariani, Antonio P; Daneliya, Mikhail

    2016-01-01

    A census of Mysidae yielded a total of twelve species plus two non-nominotypical subspecies found so far in fresh and oligohaline waters of the Mediterranean, all belonging to the subfamily Mysinae. Among the nine species in fresh-waters, three are stenoendemics, namely of a single lake (Diamysis lacustris), of two neighbouring river systems (Paramysis kosswigi) or of karstic cave waters (Troglomysis vjetrenicensis). Four species-T. vjetrenicensis, D. lacustris, D. fluviatilis, and Paramysis adriatica sp. nov. described in this paper-are confined to freshwater tributaries of the Adriatic Sea (NE-Mediterranean). This strengthens previous findings about the outstanding role of the Adriatic basin for the endemic diversity of freshwater Mysidae within the Mediterranean. This is possibly related to alternating marine and freshwater-terrestrial phases during the Pliocene-Pleistocene in this semi-enclosed basin. Based on current knowledge, freshwater populations of D. mesohalobia heterandra are also confined to the Adriatic basin; this taxon, however, shows many more populations in brackish waters of the E-Mediterranean and Marmora basins. Two freshwater species (Limnomysis benedeni, Hemimysis anomala) are wide-range invaders of Ponto-Caspian origin, with recent expansion into fresh and brackish waters of the NW-Mediterranean. A further immigrant to this part of the Mediterranean, Neomysis integer, is of NE-Atlantic origin and occurs only marginally in fresh-water.        Five among the nine species found at least once in fresh-water were also reported in oligohaline conditions, mostly also at even higher salinities. A total of eight species plus two subspecies were recorded in oligohaline waters (S = 0.5-5). Among these, only one oligohalobious stenoendemic, Diamysis hebraica, inhabits streams at the Levantine coast.        In the historical biogeographical context, the current distribution of only one out of nine indigenous species in an- to oligohaline

  6. Precipitation and Runoff Simulations of the Carson Range and Pine Nut Mountains, and Updated Estimates of Ground-Water Inflow and the Ground-Water Budgets for Basin-Fill Aquifers of Carson Valley, Douglas County, Nevada, and Alpine County, California

    USGS Publications Warehouse

    Jeton, Anne E.; Maurer, Douglas K.

    2007-01-01

    Recent estimates of ground-water inflow to the basin-fill aquifers of Carson Valley, Nevada, and California, from the adjacent Carson Range and Pine Nut Mountains ranged from 22,000 to 40,000 acre-feet per year using water-yield and chloride-balance methods. In this study, watershed models were developed for watersheds with perennial streams and for watersheds with ephemeral streams in the Carson Range and Pine Nut Mountains to provide an independent estimate of ground-water inflow. This report documents the development and calibration of the watershed models, presents model results, compares the results with recent estimates of ground-water inflow to the basin-fill aquifers of Carson Valley, and presents updated estimates of the ground-water budget for basin-fill aquifers of Carson Valley. The model used for the study was the Precipitation-Runoff Modeling System, a physically based, distributed-parameter model designed to simulate precipitation and snowmelt runoff as well as snowpack accumulation and snowmelt processes. Geographic Information System software was used to manage spatial data, characterize model drainages, and to develop Hydrologic Response Units. Models were developed for * Two watersheds with gaged perennial streams in the Carson Range and two watersheds with gaged perennial streams in the Pine Nut Mountains using measured daily mean runoff, * Ten watersheds with ungaged perennial streams using estimated daily mean runoff, * Ten watershed with ungaged ephemeral streams in the Carson Range, and * A large area of ephemeral runoff near the Pine Nut Mountains. Models developed for the gaged watersheds were used as index models to guide the calibration of models for ungaged watersheds. Model calibration was constrained by daily mean runoff for 4 gaged watersheds and for 10 ungaged watersheds in the Carson Range estimated in a previous study. The models were further constrained by annual precipitation volumes estimated in a previous study to provide

  7. Prevalence and antimicrobial susceptibility of Arcobacter species in cow milk, water buffalo milk and fresh village cheese.

    PubMed

    Yesilmen, Simten; Vural, Aydin; Erkan, Mehmet Emin; Yildirim, Ibrahim Halil

    2014-10-01

    In this study, the presence of Arcobacter spp. was examined in cow milk (n=50), water buffalo (WB) milk (n=50) and fresh village cheese (n=50) samples. The 16S rDNA-RFLP method was used for the identification of Arcobacter spp. The disc diffusion method was used to investigate the susceptibility of all strains identified to 18 different antimicrobial substances. The most commonly isolated Arcobacter species were found to be Arcobacter butzleri (38.89%), Arcobacter cryaerophilus (22.23%) and Arcobacter skirrowii (11.12%) in cow milk; A. cryaerophilus (33.33%), Arcobacter cibarius (20.83%) and A. butzleri (12.50%) in WB milk; and A. skirrowii (28.57%), A. butzleri (21.43%) and A. cryaerophilus (14.29%) in fresh village cheese. This is the first study to identify the presence of Arcobacter nitrofigilis, Arcobacter cloacae, Arcobacter halophilus, Arcobacter bivalviorum and A. cibarius species in analyzed samples. It was found that all of the A. cryaerophilus (n:16) isolates were resistant to cefoperazone, cloxacillin and penicillin G; all of the A. skirrowii (n:12) and A. butzleri (n:10) isolates were resistant to cefoperazone, tetracycline, ampicillin, erythromycin, cloxacillin and penicillin G. It was concluded that cow milk, WB milk and fresh village cheese samples are an important source of Arcobacter species and pose a risk to public health. PMID:25064812

  8. Prevalence and antimicrobial susceptibility of Arcobacter species in cow milk, water buffalo milk and fresh village cheese.

    PubMed

    Yesilmen, Simten; Vural, Aydin; Erkan, Mehmet Emin; Yildirim, Ibrahim Halil

    2014-10-01

    In this study, the presence of Arcobacter spp. was examined in cow milk (n=50), water buffalo (WB) milk (n=50) and fresh village cheese (n=50) samples. The 16S rDNA-RFLP method was used for the identification of Arcobacter spp. The disc diffusion method was used to investigate the susceptibility of all strains identified to 18 different antimicrobial substances. The most commonly isolated Arcobacter species were found to be Arcobacter butzleri (38.89%), Arcobacter cryaerophilus (22.23%) and Arcobacter skirrowii (11.12%) in cow milk; A. cryaerophilus (33.33%), Arcobacter cibarius (20.83%) and A. butzleri (12.50%) in WB milk; and A. skirrowii (28.57%), A. butzleri (21.43%) and A. cryaerophilus (14.29%) in fresh village cheese. This is the first study to identify the presence of Arcobacter nitrofigilis, Arcobacter cloacae, Arcobacter halophilus, Arcobacter bivalviorum and A. cibarius species in analyzed samples. It was found that all of the A. cryaerophilus (n:16) isolates were resistant to cefoperazone, cloxacillin and penicillin G; all of the A. skirrowii (n:12) and A. butzleri (n:10) isolates were resistant to cefoperazone, tetracycline, ampicillin, erythromycin, cloxacillin and penicillin G. It was concluded that cow milk, WB milk and fresh village cheese samples are an important source of Arcobacter species and pose a risk to public health.

  9. Dose of UV light required to inactivate Listeria monocytogenes in distilled water, fresh brine, and spent brine.

    PubMed

    McKinney, Julie; Williams, Robert C; Boardman, Gregory D; Eifert, Joseph D; Sumner, Susan S

    2009-10-01

    The purpose of this research was to establish the dose of UV light (253.7 nm) needed to inactivate Listeria monocytogenes in distilled water, fresh brine (9% NaCl), spent brine, and diluted (5, 35, and 55%) spent brine, using uridine as a chemical actinometer. Strains N1-227 (isolated from hot dog batter), N3-031 (isolated from turkey franks), and R2-499 (isolated from meat) were mixed in equal proportions and suspended in each solution prepared so as to contain 10(-4) M uridine. Samples were irradiated in sterile quartz cells for 0, 5, 10, 15, 20, 25, or 30 min. Inactivation was evaluated by serially diluting samples in 0.1% peptone, by surface plating in duplicate onto modified Oxford agar and Trypticase soy agar with yeast extract, and by enrichment in brain heart infusion broth, followed by incubation at 37 degrees C for 24 to 48 h. For dose measurements, the absorbance (262 nm) was measured before and after irradiation. Differences were observed in population estimates depending on the solution (P < or = 0.05). Reductions were as follows from greatest to least: water > fresh brine > 5% spent brine > 35% spent brine > 55% spent brine > undiluted spent brine. UV light did not significantly reduce populations suspended in spent brine solutions. L. monocytogenes decreased to below the detection limit (1 log CFU/ml) at doses greater than 33.2 mJ/cm(2) in water and at doses greater than 10.3 mJ/cm(2) in fresh brine. Knowledge of UV dosing required to control L. monocytogenes in brines similar to those used for ready-to-eat meat processing will aid manufacturers in establishing appropriate food safety interventions for these products.

  10. An Examination of the Sea Surface Salinity - Fresh Water Flux Relationship Using Satellite Observations from SMOS and Aquarius

    NASA Astrophysics Data System (ADS)

    Xie, Pingping; Kumar, Arun; Xue, Yan; Liu, Tim

    2015-04-01

    Relationship between the sea surface salinity (SSS) and the oceanic fresh water flux (E-P) is examined using the SSS retrievals derived from the passive microwave (PMW) observations aboard the SMOS and Aquarius satellites, the CMORPH integrated satellite precipitation estimates (P) and the evaporation data (E) produced by the NCEP Climate Forecast System (CFS) reanalysis. Preprocessing is performed to construct gridded fields of SSS, P, and E on a 1o lat/lon grid over the global oceans and at a 30-min time resolution for a 54-month period from January 2010 to June 2014. Relationships between the SSS observed at a point in time and the P, E, and P-E at the same grid box accumulated over various time periods ending at the SSS observation time are examined. As a first step, we focused our investigation on an oceanic area over the central equatorial Pacific (10oS-10oN; 180o-160oW) where SSS is not influenced by the river runoffs. Our preliminary results show clear linear relationship between the satellite-observed skin SSS and the fresh water flux over the region. The Aquarius observed instantaneous SSS presents a correlation of ~0.4 with the E-P accumulated over the 30-min period of the SSS observations. The correlation between the instantaneous SSS and the E-P drops with the accumulation period for E-P, down to 0.36 for 6-hourly accumulated E-P. The Correlation, however, bounces back and improves with the E-P accumulation period longer than 6 hours, reaching to ~0.7 for an accumulation time period of 30 days. The existence of the minimum correlation between the instantaneous SSS and the E-P accumulation over a 6-hour period suggests the involvement of air-sea interaction and oceanic processes on multiple time scales in the manner E-P influences to the SSS variations. Among the two primary components of the fresh water flux, precipitation dominates the influences on the SSS. Further analysis is under way to repeat the examination for different regions to examine the

  11. Involving regional expertise in nationwide modeling for adequate prediction of climate change effects on different demands for fresh water

    NASA Astrophysics Data System (ADS)

    de Lange, W. J.

    2014-05-01

    Wim J. de Lange, Geert F. Prinsen, Jacco H. Hoogewoud, Ab A Veldhuizen, Joachim Hunink, Erik F.W. Ruijgh, Timo Kroon Nationwide modeling aims to produce a balanced distribution of climate change effects (e.g. harm on crops) and possible compensation (e.g. volume fresh water) based on consistent calculation. The present work is based on the Netherlands Hydrological Instrument (NHI, www.nhi.nu), which is a national, integrated, hydrological model that simulates distribution, flow and storage of all water in the surface water and groundwater systems. The instrument is developed to assess the impact on water use on land-surface (sprinkling crops, drinking water) and in surface water (navigation, cooling). The regional expertise involved in the development of NHI come from all parties involved in the use, production and management of water, such as waterboards, drinking water supply companies, provinces, ngo's, and so on. Adequate prediction implies that the model computes changes in the order of magnitude that is relevant to the effects. In scenarios related to drought, adequate prediction applies to the water demand and the hydrological effects during average, dry, very dry and extremely dry periods. The NHI acts as a part of the so-called Deltamodel (www.deltamodel.nl), which aims to predict effects and compensating measures of climate change both on safety against flooding and on water shortage during drought. To assess the effects, a limited number of well-defined scenarios is used within the Deltamodel. The effects on demand of fresh water consist of an increase of the demand e.g. for surface water level control to prevent dike burst, for flushing salt in ditches, for sprinkling of crops, for preserving wet nature and so on. Many of the effects are dealt with by regional and local parties. Therefore, these parties have large interest in the outcome of the scenario analyses. They are participating in the assessment of the NHI previous to the start of the analyses

  12. Involving regional expertise in nationwide modeling for adequate prediction of climate change effects on different demands for fresh water

    NASA Astrophysics Data System (ADS)

    de Lange, Wim; Prinsen, Geert.; Hoogewoud, Jacco; Veldhuizen, Ab; Ruijgh, Erik; Kroon, Timo

    2013-04-01

    Nationwide modeling aims to produce a balanced distribution of climate change effects (e.g. harm on crops) and possible compensation (e.g. volume fresh water) based on consistent calculation. The present work is based on the Netherlands Hydrological Instrument (NHI, www.nhi.nu), which is a national, integrated, hydrological model that simulates distribution, flow and storage of all water in the surface water and groundwater systems. The instrument is developed to assess the impact on water use on land-surface (sprinkling crops, drinking water) and in surface water (navigation, cooling). The regional expertise involved in the development of NHI come from all parties involved in the use, production and management of water, such as waterboards, drinking water supply companies, provinces, ngo's, and so on. Adequate prediction implies that the model computes changes in the order of magnitude that is relevant to the effects. In scenarios related to drought, adequate prediction applies to the water demand and the hydrological effects during average, dry, very dry and extremely dry periods. The NHI acts as a part of the so-called Deltamodel (www.deltamodel.nl), which aims to predict effects and compensating measures of climate change both on safety against flooding and on water shortage during drought. To assess the effects, a limited number of well-defined scenarios is used within the Deltamodel. The effects on demand of fresh water consist of an increase of the demand e.g. for surface water level control to prevent dike burst, for flushing salt in ditches, for sprinkling of crops, for preserving wet nature and so on. Many of the effects are dealt with? by regional and local parties. Therefore, these parties have large interest in the outcome of the scenario analyses. They are participating in the assessment of the NHI previous to the start of the analyses. Regional expertise is welcomed in the calibration phase of NHI. It aims to reduce uncertainties by improving the

  13. Collection of fission and activation product elements from fresh and ocean waters: a comparison of traditional and novel sorbents

    SciTech Connect

    Johnson, Bryce E.; Santschi, Peter H.; Addleman, Raymond S.; Douglas, Matthew; Davidson, Joseph D.; Fryxell, Glen E.; Schwantes, Jon M.

    2010-04-01

    Monitoring natural waters for the inadvertent release of radioactive fission products produced as a result of nuclear power generation downstream from these facilities is essential for maintaining water quality. To this end, we evaluated sorbents for simultaneous in-situ large volume extraction of radionuclides with both soft (e.g., Ag) and hard metal (e.g., Co, Zr, Nb, Ba, and Cs) or anionic (e.g., Ru, Te, Sb) character. In this study, we evaluated a number of conventional and novel nanoporous sorbents in both fresh and salt waters. In most cases, the nanoporous sorbents demonstrated enhanced retention of analytes. Salinity had significant effects upon sorbent performance and was most significant for hard cations, specifically Cs and Ba. The presence of natural organic matter had little effect on the ability of chemisorbents to extract target elements.

  14. Suspended-sediment and fresh-water discharges in the Ob and Yenisey rivers, 1960-1988

    USGS Publications Warehouse

    Meade, R.H.; Bobrovitskaya, N.N.; Babkin, V.I.

    2000-01-01

    Of the world's great rivers, the Ob and Yenisey rank among the largest suppliers of fresh water and among the smallest suppliers of suspended sediment to the coastal ocean. Sediment in the middle reaches of the rivers is mobilized from bordering terraces and exchanged between channels and flood plains. Sediment in the lower reaches of these great rivers is deposited and stored (permanently, on a millennial time scale) in flood plains. Sediment discharges, already small under natural conditions, are diminished further by large manmade reservoirs that trap significant proportions of the moving solids. The long winter freeze and sudden spring breakup impose a peakedness in seasonal water runoff and sediment discharge that contrasts markedly with that in rivers of the tropics and more temperate climates. Very little sediment from the Ob and Yenisey rivers is being transported to the open waters of the Arctic Ocean under present conditions.

  15. Fresh-water lenses and practical limitations of their three-dimensional simulation

    NASA Astrophysics Data System (ADS)

    Ghassemi, F.; Alam, K.; Howard, K. W. F.

    2000-08-01

    Fresh-water lenses are the major sources of water supply in many atoll islands in the Pacific and Indian Oceans, particularly in dry seasons. Several two- and three-dimensional models are currently available for the simulation of atoll-island aquifers; however, 2D models cannot include 3D spatial variability of material properties, they must simplify the boundary conditions, and they cannot correctly simulate pumping wells. In an attempt to overcome these difficulties, a 3D model, SALTFLOW, was adopted for the simulation of Home Island in the Indian Ocean. This exercise required a discretisation on the order of a few metres and time steps of a few hours requiring significantly high CPU times. High CPU demand proved to be a difficult challenge but cannot be considered a serious practical limitation with today's advanced computers. The exhaustive data demands of the model (e.g., 3D distributions of hydraulic conductivity, porosity, dispersivities, and spatial and temporal variations of recharge and extraction rates) proved to be more problematical. Although the Home Island data set is unusually comprehensive by any standards, nonetheless the quality and quantity of the available data proved inadequate to meet the calibration needs of a highly karstic aquifer system. The Home Island modeling demonstrates the practical limitations of 3D models. It raises the concern that our ability to develop computer codes capable of simulating complex systems now exceeds our ability to supply the input data necessary for reliable calibration. Finally, the paper demonstrates the importance of the transient calibration in reliable simulation of various management options and emphasises that transient calibration should be considered as an integral part of any similar 2D or 3D modeling. Résumé. Les lentilles d'eau douce sont la source essentielle d'eau potable pour l'alimentation de nombreux atolls du Pacifique et de l'Océan Indien, notamment au cours des saisons sèches. Plusieurs

  16. A novel reflectance-based model for evaluating chlorophyll concentrations of fresh and water-stressed leaves

    NASA Astrophysics Data System (ADS)

    Lin, C.; Popescu, S. C.; Huang, S. C.; Chang, P. T.; Wen, H. L.

    2015-01-01

    Water deficits can cause chlorophyll degradation which decreases the total concentration of chlorophyll a and b (Chls). Few studies have investigated the effectiveness of spectral indices under water-stressed conditions. Chlorophyll meters have been extensively used for a wide variety of leaf chlorophyll and nitrogen estimations. Since a chlorophyll meter works by sensing leaves absorptance and transmittance, the reading of chlorophyll concentration will be affected by changes in transmittance as if there were a water deficit in the leaves. The overall objective of this paper was to develop a novel and reliable reflectance-based model for estimating Chls of fresh and water-stressed leaves using the reflectance at the absorption bands of chlorophyll a and b and the red edge spectrum. Three independent experiments were designed to collect data from three leaf sample sets for the construction and validation of Chls estimation models. First, a reflectance experiment was conducted to collect foliar Chls and reflectance of leaves with varying water stress using the ASD FieldSpec spectroradiometer. Second, a chlorophyll meter (SPAD-502) experiment was carried out to collect foliar Chls and meter readings. These two data sets were separately used for developing reflectance-based or absorptance-based Chls estimation models using linear and nonlinear regression analysis. Suitable models were suggested mainly based on the coefficient of determination (R2). Finally, an experiment was conducted to collect the third data set for the validation of Chls models using the root mean squared error (RMSE) and the mean absolute error (MAE). In all of the experiments, the observations (real values) of the foliar Chls were extracted from acetone solution and determined by using a Hitachi U-2000 spectrophotometer. The spectral indices in the form of reflectance ratio/difference/slope derived from the Chl b absorption bands (ρ645 and ρ455) provided Chls estimates with RMSE around 0

  17. The influence of wellbore inflow on electromagnetic borehole flowmeter measurements

    USGS Publications Warehouse

    Clemo, T.; Barrash, W.; Reboulet, E.C.; Johnson, T.C.; Leven, C.

    2009-01-01

    This paper describes a combined field, laboratory, and numerical study of electromagnetic borehole flowmeter measurements acquired without the use of a packer or skirt to block bypass flow around the flowmeter. The most significant finding is that inflow through the wellbore screen changes the ratio of flow through the flowmeter to wellbore flow. Experiments reveal up to a factor of two differences in this ratio for conditions with and without inflow through the wellbore screen. Standard practice is to assume the ratio is constant. A numerical model has been developed to simulate the effect of inflow on the flowmeter. The model is formulated using momentum conservation within the borehole and around the flowmeter. The model is embedded in the MODFLOW-2000 ground water flow code. ?? 2009 National Ground Water Association.

  18. A comparative study on biologically and chemically synthesized silver nanoparticles induced Heat Shock Proteins on fresh water fish Oreochromis niloticus.

    PubMed

    Girilal, M; Krishnakumar, V; Poornima, Paramasivan; Mohammed Fayaz, A; Kalaichelvan, P T

    2015-11-01

    The wide applicability of silver nanoparticles in medicine and pharmaceutical industries leads to its over exploitation and thus contaminating our environment. Majority of these nanoscale dimension particles finally accumulates in fresh water and marine ecosystem. As the nanoparticles behave entirely different from its corresponding bulk material, a better understanding of their environmental impacts in aquatic ecosystems is inevitable. The study was focused on a comparative stress physiology analysis of chemically synthesized silver nanoparticles and biogenic silver nanoparticles. Half maximal inhibitory concentration of biologically synthesized and chemically synthesized nanoparticles was found out (30μg/mL and 20μg/mL respectively). The Heat Shock Protein (HSP70) secretion was analysed in the fresh water fish Oreochromis niloticus after exposing to different concentrations of biologically and chemically synthesized silver nanoparticles along with the silver in its ionic form. The intense immune-histochemical staining of fish tissues (muscle, kidney and liver) analyzed proportionately reflected the stress created. The colour intensity was directly proportional to the stress created or the stress protein released. High level of HSP70 expression was observed in all of the fish tissues exposed to silver ions and chemically synthesized silver nanoparticles, when compared to that of biologically synthesized. The results revealed the significance of comparatively safe and less toxic biogenic nanoparticles compared to the chemically synthesized. PMID:26291676

  19. Ceriodaphnia dubia as a Potential Bio-Indicator for Assessing Acute Aluminum Oxide Nanoparticle Toxicity in Fresh Water Environment

    PubMed Central

    Pakrashi, Sunandan; Dalai, Swayamprava; Humayun, Ahmed; Chakravarty, Sujay; Chandrasekaran, Natarajan; Mukherjee, Amitava

    2013-01-01

    Growing nanomaterials based consumer applications have raised concerns about their potential release into the aquatic ecosystems and the consequent toxicological impacts. So environmental monitoring of the nanomaterials in aqueous systems becomes imperative. The current study reveals the potential of Ceriodaphnia dubia (C. dubia) as a bio-indicator for aluminum oxide nanoparticles in a fresh water aquatic ecosystem where it occupies an important ecological niche as a primary consumer. This study aims to investigate the aluminium oxide nanoparticle induced acute toxicity on Ceriodaphnia dubia in a freshwater system. The bioavailability of the aluminum oxide nanoparticles has been studied with respect to their aggregation behavior in the system and correlated with the toxicity endpoints. The oxidative stress generated by the particles contributed greatly toward their toxicity. The crucial role of leached aluminium ion mediated toxicity in the later phases (48 h and 72 h) in conjunction with the effects from the nano-sized particles in the initial phases (24 h) puts forth the dynamics of nanotoxicity in the test system. The internalization of nanoparticles (both gross and systemic uptake) as substantiated through the transmission electron microscopy (TEM) and inductively coupled plasma optical emission spectral (ICP-OES) analysis was another major contributor toward acute toxicity. Concluding the present study, Ceriodaphnia dubia can be a promising candidate for bio-monitoring the aluminium oxide nanoparticles in a fresh water system. PMID:24040143

  20. A comparative study on biologically and chemically synthesized silver nanoparticles induced Heat Shock Proteins on fresh water fish Oreochromis niloticus.

    PubMed

    Girilal, M; Krishnakumar, V; Poornima, Paramasivan; Mohammed Fayaz, A; Kalaichelvan, P T

    2015-11-01

    The wide applicability of silver nanoparticles in medicine and pharmaceutical industries leads to its over exploitation and thus contaminating our environment. Majority of these nanoscale dimension particles finally accumulates in fresh water and marine ecosystem. As the nanoparticles behave entirely different from its corresponding bulk material, a better understanding of their environmental impacts in aquatic ecosystems is inevitable. The study was focused on a comparative stress physiology analysis of chemically synthesized silver nanoparticles and biogenic silver nanoparticles. Half maximal inhibitory concentration of biologically synthesized and chemically synthesized nanoparticles was found out (30μg/mL and 20μg/mL respectively). The Heat Shock Protein (HSP70) secretion was analysed in the fresh water fish Oreochromis niloticus after exposing to different concentrations of biologically and chemically synthesized silver nanoparticles along with the silver in its ionic form. The intense immune-histochemical staining of fish tissues (muscle, kidney and liver) analyzed proportionately reflected the stress created. The colour intensity was directly proportional to the stress created or the stress protein released. High level of HSP70 expression was observed in all of the fish tissues exposed to silver ions and chemically synthesized silver nanoparticles, when compared to that of biologically synthesized. The results revealed the significance of comparatively safe and less toxic biogenic nanoparticles compared to the chemically synthesized.

  1. Ceriodaphnia dubia as a potential bio-indicator for assessing acute aluminum oxide nanoparticle toxicity in fresh water environment.

    PubMed

    Pakrashi, Sunandan; Dalai, Swayamprava; Humayun, Ahmed; Chakravarty, Sujay; Chandrasekaran, Natarajan; Mukherjee, Amitava

    2013-01-01

    Growing nanomaterials based consumer applications have raised concerns about their potential release into the aquatic ecosystems and the consequent toxicological impacts. So environmental monitoring of the nanomaterials in aqueous systems becomes imperative. The current study reveals the potential of Ceriodaphnia dubia (C. dubia) as a bio-indicator for aluminum oxide nanoparticles in a fresh water aquatic ecosystem where it occupies an important ecological niche as a primary consumer. This study aims to investigate the aluminium oxide nanoparticle induced acute toxicity on Ceriodaphnia dubia in a freshwater system. The bioavailability of the aluminum oxide nanoparticles has been studied with respect to their aggregation behavior in the system and correlated with the toxicity endpoints. The oxidative stress generated by the particles contributed greatly toward their toxicity. The crucial role of leached aluminium ion mediated toxicity in the later phases (48 h and 72 h) in conjunction with the effects from the nano-sized particles in the initial phases (24 h) puts forth the dynamics of nanotoxicity in the test system. The internalization of nanoparticles (both gross and systemic uptake) as substantiated through the transmission electron microscopy (TEM) and inductively coupled plasma optical emission spectral (ICP-OES) analysis was another major contributor toward acute toxicity. Concluding the present study, Ceriodaphnia dubia can be a promising candidate for bio-monitoring the aluminium oxide nanoparticles in a fresh water system.

  2. Uranium Series Diagenesis in Corals Exposed to Fresh Water: Toward Better Prospecting for Closed System Samples for High Accuracy Dating

    NASA Astrophysics Data System (ADS)

    Mey, J.; Fairbanks, R.; Mortlock, R.; Bradtmiller, L.

    2005-12-01

    A better understanding of U-series diagenesis in corals exposed to the vadose and phreatic freshwater environments is required to help prospect for closed-system samples needed for high-accuracy dates. Disequilibrium U-series are common in corals exposed to fresh water and a priori screening is generally insufficient to reject samples prior to dating. As a result, a vast number of U-series dates reported in the literature are open system and numerous authors have resorted to various correction models (Bender et al., 1979; Gallup et al., 1994; Thompson et al., 2003; Villemant and Feuillet, 2003; and Scholz et al., 2004). The majority of studies assumes or models continuous or episodic addition of 234U and/or 230Th over time and relies on the low solubility of 230Th and/or 234Th. Several recent studies emphasize progressive production of 234U via α-recoil (Thompson et al., 2003; Villemant and Feuillet, 2003), however the application of these models may lead to over-parameterization and are mainly idiosyncratic to host sample locations (Scholz et al., 2004). Already, some studies make model corrections to open system ages and draw critical conclusions about sea level change (e.g. Scholz et al., 2004; Thompson and Goldstein, 2005). Characteristic of all of these studies is a general correlation between the 234U/238U activity ratio and the 230Th/238U activity ratio between intra-reef samples. On Barbados, the largest activity ratio offsets appear in the youngest samples exposed to fresh water; just the opposite finding of most diagenesis models. Our measurements are consistent with the observations of Scholz et al. (2004) from the Red Sea. The greatest addition of 234U, 230Th, and 231Pa to the Barbados samples occurred during the first exposure to fresh water, in this case Marine Isotope State 3 (MIS3), when 234U, 230Th, and 231Pa are added to samples in similar proportions, but varying amounts. The bulk of reef sands and rubble is aragonite, which releases U

  3. Uptake of uranium by aquatic plants growing in fresh water ecosystem around uranium mill tailings pond at Jaduguda, India.

    PubMed

    Jha, V N; Tripathi, R M; Sethy, N K; Sahoo, S K

    2016-01-01

    Concentration of uranium was determined in aquatic plants and substrate (sediment or water) of fresh water ecosystem on and around uranium mill tailings pond at Jaduguda, India. Aquatic plant/substrate concentration ratios (CRs) of uranium were estimated for different sites on and around the uranium mill tailings disposal area. These sites include upstream and downstream side of surface water sources carrying the treated tailings effluent, a small pond inside tailings disposal area and residual water of this area. Three types of plant groups were investigated namely algae (filamentous and non-filamentous), other free floating & water submerged and sediment rooted plants. Wide variability in concentration ratio was observed for different groups of plants studied. The filamentous algae uranium concentration was significantly correlated with that of water (r=0.86, p<0.003). For sediment rooted plants significant correlation was found between uranium concentration in plant and the substrate (r=0.88, p<0.001). Both for other free floating species and sediment rooted plants, uranium concentration was significantly correlated with Mn, Fe, and Ni concentration of plants (p<0.01). Filamentous algae, Jussiaea and Pistia owing to their high bioproductivity, biomass, uranium accumulation and concentration ratio can be useful for prospecting phytoremediation of stream carrying treated or untreated uranium mill tailings effluent.

  4. Estimation of Fresh and Salt Water Fluxes and Transports in the Indian Ocean using satellite observations and model simulations

    NASA Astrophysics Data System (ADS)

    Bulusu, Subrahmanyam; Nyadjro, Ebenezer

    2014-05-01

    This study describes the fresh and salt water fluxes and transports in the Indian Ocean using satellite-derived salinity observations from the SMOS (Soil Moisture and Ocean Salinity) and Aquarius missions, and model outputs from the HYbrid Coordinate Ocean Model (HYCOM) and the Simple Ocean Data Assimilation (SODA) Re-analysis. Argo salinity data is used to validate the aforementioned salinity datasets. Salt budget estimations using SMOS salinity data show favorable comparisons with published results, with the potential for additional novel studies when more valid satellite-derived salinity data become available. On seasonal time scales, there is a considerable exchange of salt and fresh waters between the Bay of Bengal (BoB) and the Arabian Sea (AS) and vice versa. The pathways of the high/low salinity waters are identified using satellite observations. The Sea Surface Salinity (SSS) changes in the Southeastern Arabian Sea are as a result of the advection of low salinity waters from the BoB via coastal Kelvin waves. The long term mean salt transport shows seasonal reversals that are more pronounced in the northern Indian Ocean than in the southern Indian Ocean. Meridional salt transport is northward along the Somali Current (SC) in the Arabian Sea and the East India coastal Current (EICC) in the Bay of Bengal during the southwest monsoon season. The opposite holds during the northeast monsoon season. Mean zonal salt transport is of a higher magnitude than the meridional component and shows significant seasonal reversals in the equatorial region. Empirical Orthogonal Function (EOF) analyses of meridional salt transport show that the variability is primarily seasonally driven and is the result of seasonally reversing monsoonal winds and currents. The amplitudes of the EOFs suggest that the Indian Ocean dipole may also influence the variability. Spatially, the most variable regions are along the northeast African coast, and in the eastern Arabian Sea, the Bay of

  5. Drought to flood: a comparative assessment of four parallel surface water treatments during the 2010-2012 inflows to the Murray-Darling Basin, South Australia.

    PubMed

    Braun, Kalan; Fabris, Rolando; Morran, Jim; Ho, Lionel; Drikas, Mary

    2014-08-01

    Four treatment processes; conventional coagulation, magnetic ion exchange (MIEX)/coagulation, with and without granular activated carbon (GAC), and membrane treatment combining microfiltration (MF) and nanofiltration (NF), were operated in parallel using the same source water from the Murray-Darling basin in South Australia. During the two year study, high levels of natural organic matter and turbidity arising from floods affecting the Murray-Darling basin in 2010-2012 challenged the four processes. The comparative study indicated that all four processes could effectively meet basic water quality guidelines of turbidity and colour despite challenging source water quality but that the more advanced treatments improved overall organic and bacterial removal. Interestingly, the high organics and turbidity arising from the floods resulted in improved treatment efficiency for all treatments incorporating coagulation to the extent that, despite flood conditions, treated water quality could remain comparatively constant provided that the process was operated and optimised effectively.

  6. On variable density surface water groundwater interaction: A theoretical analysis of mixed convection in a stably-stratified fresh surface water saline groundwater discharge zone

    NASA Astrophysics Data System (ADS)

    Massmann, Gudrun; Simmons, Craig; Love, Andrew; Ward, James; James-Smith, Julianne

    2006-10-01

    SummaryUnderstanding the discharge behaviour of saline groundwater into fresh surface water can be critical for the effective management of water resources. While variable density flow has been studied intensely in a number of settings, the role it plays on the discharge behaviour of saline groundwater into freshwater streams is often neglected when calculating salt loads into a stream. The aim of this study was to determine what role variable-density flow behaviour plays in surface water/groundwater interaction in a stably-stratified fresh surface water/saline groundwater interface. The mixed convection ratio M, a measure of the ratio of density driven flow to advective driven flow, was defined for a matrix of one-dimensional numerical simulations that employed both varying hydraulic and density gradients. Vertical salt breakthrough into the surface water only occurred in the advection dominated cases ( M < 1) and the salt flux into the surface water increased with increasing groundwater concentration until M reached a value of 1. Beyond this, when the flow was driven by the density difference between the two fluids ( M > 1) vertical discharge of salt into surface water did not occur and the saltwater/freshwater interface migrated downwards with increasing density differences between the two fluids. This study therefore shows that there is a critical concentration difference that maximises salt loads to a surface water body and that a density-invariant approach to estimate the salt flux into the surface water (as the product of flow velocity determined through a potentiometric analysis and groundwater concentration) may be inadequate, especially where large density differences exist between the fresher surface water body and the underlying saline groundwater. The study is a purely theoretical approach and conclusions were drawn from simplified 1D simulations. Hence, further laboratory and modelling work is needed to confirm and test the plausibility of these

  7. Relative importance of natural and anthropogenic influences on the fresh surface water chemistry of the Hawkesbury-Nepean River, south-eastern Australia.

    PubMed

    Markich, S J; Brown, P L

    1998-07-01

    Fresh surface waters from the Hawkesbury-Nepean River, the major river supplying water to the Sydney region in south-eastern Australia, were sampled monthly during 1991 and analysed for major ions (Na, K, Ca, Mg, Cl, SO4 and HCO3), nutrients (NO3 and PO4), organic carbon and trace metals (Al, Fe, Cu, Zn, Pb, Cd, Ni, Co and Mn). The chemical composition of the river during 1991 was consistent with other studies of the river from 1977 to 1996. The major ion composition in the river is predominantly influenced by sea-salt aerosols in rainwater (headwaters) and connate sea-salt in groundwater (mid-lower reaches), with a cationic dominance order of Na > Mg > Ca > K (equivalents) and an anionic order of Cl > HCO3 > SO4. This is typical of the headwaters of other permanent coastal rivers (freshwater) in south-eastern Australia with a similar catchment lithology. These results differ markedly from the most common natural major ion assemblages established for world rivers (i.e. Ca > Mg > Na > K and HCO3 > SO4 > Cl), which tend to be predominantly influenced by chemical weathering of rocks and minerals. The mean concentrations of major ions, nutrients, organic carbon and trace metals in the freshwater reaches of the Hawkesbury-Nepean River increased by factors of 2.5-4.4, 14-18, 2.2 and 1.6-11, respectively, with increasing distance from the headwaters. Increases in major ion concentrations are attributed mainly to the increasing influence of saline groundwater inflows from regions of Wianamatta shale. Conversely, concentrations of nutrients, organic carbon and trace metals (except Fe and Al) increased as a consequence of anthropogenic inputs, particularly point discharges from sewage treatment plants (i.e. showing distinct, but variable, concentration peaks), as well as diffuse urban and/or agricultural runoff during storm events. The temporal variability of the mean concentrations of all measured parameters in this study was related to variability in water discharge. The

  8. 40 CFR 35.927-1 - Infiltration/inflow analysis.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 1 2014-07-01 2014-07-01 false Infiltration/inflow analysis. 35.927-1 Section 35.927-1 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works-Clean Water Act §...

  9. Potential fresh water saving using greywater in toilet flushing in Syria.

    PubMed

    Mourad, Khaldoon A; Berndtsson, Justyna C; Berndtsson, Ronny

    2011-10-01

    Greywater reuse is becoming an increasingly important factor for potable water saving in many countries. Syria is one of the most water scarce countries in the Middle East. However, greywater reuse is still not common in the country. Regulations and standards for greywater reuse are not available. Recently, however, several stakeholders have started to plan for greywater reuse. The main objective of this paper is to evaluate the potential for potable water saving by using greywater for toilet flushing in a typical Syrian city. The Sweida city in the southern part of Syria was chosen for this purpose. Interviews were made in order to reflect the social acceptance, water consumption, and the percentage of different indoor water uses. An artificial wetland (AW) and a commercial bio filter (CBF) were proposed to treat the greywater, and an economic analysis was performed for the treatment system. Results show that using treated greywater for toilet flushing would save about 35% of the drinking water. The economic analyses of the two proposed systems showed that, in the current water tariff, the payback period for AW and CBF in block systems is 7 and 52 years, respectively. However, this period will reduce to 3 and 21 years, respectively, if full water costs are paid by beneficiaries. Hence, introducing artificial wetlands in order to make greywater use efficient appears to be a viable alternative to save potable water.

  10. Variations of DOM quality in inflows of a drinking water reservoir: linking of van Krevelen diagrams with EEMF spectra by rank correlation.

    PubMed

    Herzsprung, Peter; von Tümpling, Wolf; Hertkorn, Norbert; Harir, Mourad; Büttner, Olaf; Bravidor, Jenny; Friese, Kurt; Schmitt-Kopplin, Philippe

    2012-05-15

    Elevated concentrations of dissolved organic matter (DOM) such as humic substances in raw water pose significant challenges during the processing of the commercial drinking water supplies. This is a relevant issue in Saxony, Central East Germany, and many other regions worldwide, where drinking water is produced from raw waters with noticeable presence of chromophoric DOM (CDOM), which is assumed to originate from forested watersheds in spring regions of the catchment area. For improved comprehension of DOM molecular composition, the seasonal and spatial variations of humic-like fluorescence and elemental formulas in the catchment area of the Muldenberg reservoir were recorded by excitation emission matrix fluorescence (EEMF) and ultrahigh-resolution mass spectrometry (FT-ICR-MS). The Spearman rank correlation was applied to link the EEMF intensities with exact molecular formulas and their corresponding relative mass peak abundances. Thereby, humic-like fluorescence could be allocated to the pool of oxygen-rich and relatively unsaturated components with stoichiometries similar to those of tannic acids, which are suspected to have a comparatively high disinfection byproduct formation potential associated with the chlorination of raw water. Analogous relationships were established for UV absorption at 254 nm (UV(254)) and dissolved organic carbon (DOC) and compared to the EEMF correlation.

  11. Entanglement entropy and anomaly inflow

    NASA Astrophysics Data System (ADS)

    Hughes, Taylor L.; Leigh, Robert G.; Parrikar, Onkar; Ramamurthy, Srinidhi T.

    2016-03-01

    We study entanglement entropy for parity-violating (time-reversal breaking) quantum field theories on R1 ,2 in the presence of a domain wall between two distinct parity-odd phases. The domain wall hosts a 1 +1 -dimensional conformal field theory (CFT) with nontrivial chiral central charge. Such a CFT possesses gravitational anomalies. It has been shown recently that, as a consequence, its intrinsic entanglement entropy is sensitive to Lorentz boosts around the entangling surface. Here, we show using various methods that the entanglement entropy of the three-dimensional bulk theory is also sensitive to such boosts owing to parity-violating effects, and that the bulk response to a Lorentz boost precisely cancels the contribution coming from the domain wall CFT. We argue that this can naturally be interpreted as entanglement inflow (i.e., inflow of entanglement entropy analogous to the familiar Callan-Harvey effect) between the bulk and the domain-wall, mediated by the low-lying states in the entanglement spectrum. These results can be generally applied to 2 +1 -d topological phases of matter that have edge theories with gravitational anomalies, and provide a precise connection between the gravitational anomaly of the physical edge theory and the low-lying spectrum of the entanglement Hamiltonian.

  12. Corrosion of stainless steel piping in a high manganese fresh water

    SciTech Connect

    Avery, R.E.; Lutey, R.W.; Musick, J.; Pinnow, K.E.; Tuthill, A.H.

    1996-07-01

    In March of 1993, about two years after startup in early 1991, pinhole leaks were found in the 16 in. (406 mm) type 304L stainless steel (UNS S30403) raw water piping at the Brunswick-Topsham Water District (BTWD) Potable Water Treatment Plant (PWTP) in Brunswick, Maine. The low chloride manganese-containing well water is chlorinated in the pump house. After reaching the plant, the raw water is handled in type 304L stainless steel (UNS S30403) piping. It was initially felt that the corrosion might be the microbiologically influenced corrosion (MIC) type corrosion described by Tverberg, Pinnow, and Redmerski. Investigation showed that the role of manganese and chlorine differed, in important respects, from that described by Tverberg et. al., and that heat tint scale may have played a significant role in the corrosion that occurred at the BTWD plant.

  13. F-specific RNA bacteriophages are adequate model organisms for enteric viruses in fresh water.

    PubMed Central

    Havelaar, A H; van Olphen, M; Drost, Y C

    1993-01-01

    Culturable enteroviruses were detected by applying concentration techniques and by inoculating the concentrates on the BGM cell line. Samples were obtained from a wide variety of environments, including raw sewage, secondary effluent, coagulated effluent, chlorinated and UV-irradiated effluents, river water, coagulated river water, and lake water. The virus concentrations varied widely between 0.001 and 570/liter. The same cell line also supported growth of reoviruses, which were abundant in winter (up to 95% of the viruses detected) and scarce in summer (less than 15%). The concentrations of three groups of model organisms in relation to virus concentrations were also studied. The concentrations of bacteria (thermotolerant coliforms and fecal streptococci) were significantly correlated with virus concentrations in river water and coagulated secondary effluent, but were relatively low in disinfected effluents and relatively high in surface water open to nonhuman fecal pollution. The concentrations of F-specific RNA bacteriophages (FRNA phages) were highly correlated with virus concentrations in all environments studied except raw and biologically treated sewage. Numerical relationships were consistent over the whole range of environments; the regression equations for FRNA phages on viruses in river water and lake water were statistically equivalent. These relationships support the possibility that enteric virus concentrations can be predicted from FRNA phage data. PMID:8215367

  14. INVESTIGATIONS INTO THE EFFECTS OF SEASON AND WATER QUALITY ON OYSTERS (CRASSOSTREA VIRGINICA) AND ASSOCIATED FISH ASSEMBLAGES IN THE CALOOSAHATCHEE RIVER ESTUARY, FLORIDA: IMPLICATIONS OF ALTERED FRESHWATER INFLOW

    EPA Science Inventory

    A suite of biological and ecological responses of a Valued Ecosystem Component species, Crassostrea virginica, was used to investigate ecosystem-wide health effects of watershed alterations in the Caloosahatchee River estuary, Florida. The influence of water quality and season on...

  15. Preservation of human tissue immersed for five years in fresh water of known temperature.

    PubMed

    Cotton, G E; Aufderheide, A C; Goldschmidt, V G

    1987-07-01

    Two human bodies were recovered from the waters of the Duluth, Minnesota harbor. Extensive adipocere formation resulted in remarkable preservation of gross anatomic features of internal organs. Total time of immersion could be precisely estimated at five years. Water temperature during those five years could also be accurately estimated by direct measurements taken during the year following recovery of the bodies and from information supplied by a local electric power generating company. Immersion occurred at the time of the year when water temperature was highest (70 degrees F [21 degrees C]) facilitating the rapid formation of adipocere. A proposed mechanism for formation of adipocere is described.

  16. Accumulation and distributions of {sup 137}Cs in fresh water snail Pila ampullacea

    SciTech Connect

    Suseno, Heny

    2014-10-24

    Pila ampullacea are found in tropical freshwaters of Indonesia. This snail exhibit several characteristics of ideal indicator organisms in order to understand the bioaccumulation of {sup 137}Cs. Biokinetic experiment was performaced in aquaria system and under influenced of concentration K{sup +} in water. The result of experiment shown that Under difference K{sup +} concentration in water, Pila ampullacea have capability to accumulated {sup 137}Cs with CF value range 8.95 to 12.52 ml.g{sup −1}. Both uptake and depuration rate were influenced by concentration of K{sup +} in water.

  17. Novel Conductive Carbon Black and Polydimethlysiloxane ECG Electrode: A Comparison with Commercial Electrodes in Fresh, Chlorinated, and Salt Water.

    PubMed

    Noh, Yeonsik; Bales, Justin R; Reyes, Bersain A; Molignano, Jennifer; Clement, Amanda L; Pins, George D; Florian, John P; Chon, Ki H

    2016-08-01

    In this study, we evaluated the performance of two novel conductive carbon black (CB) and polydimethlysiloxane (PDMS) bio-potential electrodes, with and without an integrated flexible copper mesh, against commercially available electrodes (Polar(®) textile, Silver-coated textile, and carbon rubber). The electrodes were tested in three types of water (fresh/unfiltered, chlorinated, and salt water). Our testing revealed that our CB/PDMS electrode with integrated copper mesh provided a high-fidelity ECG signal morphologies without any amplitude degradation in all of the types of water tested (N = 10). The non-meshed CB/PDMS electrodes were also subjected to a long-term durability test by the US Navy SCUBA divers during which the electrodes maintained ECG signal quality for a 6 h period of continuous use. The results of a material degradation analysis revealed the CB/PDMS composite material does not exhibit significant changes in physical integrity after prolonged exposure to the test conditions. The newly developed meshed CB/PDMS electrodes have the potential to be used in a wide variety of both dry and wet environments including the challenge of obtaining ECG signals in salt water environments.

  18. Novel Conductive Carbon Black and Polydimethlysiloxane ECG Electrode: A Comparison with Commercial Electrodes in Fresh, Chlorinated, and Salt Water.

    PubMed

    Noh, Yeonsik; Bales, Justin R; Reyes, Bersain A; Molignano, Jennifer; Clement, Amanda L; Pins, George D; Florian, John P; Chon, Ki H

    2016-08-01

    In this study, we evaluated the performance of two novel conductive carbon black (CB) and polydimethlysiloxane (PDMS) bio-potential electrodes, with and without an integrated flexible copper mesh, against commercially available electrodes (Polar(®) textile, Silver-coated textile, and carbon rubber). The electrodes were tested in three types of water (fresh/unfiltered, chlorinated, and salt water). Our testing revealed that our CB/PDMS electrode with integrated copper mesh provided a high-fidelity ECG signal morphologies without any amplitude degradation in all of the types of water tested (N = 10). The non-meshed CB/PDMS electrodes were also subjected to a long-term durability test by the US Navy SCUBA divers during which the electrodes maintained ECG signal quality for a 6 h period of continuous use. The results of a material degradation analysis revealed the CB/PDMS composite material does not exhibit significant changes in physical integrity after prolonged exposure to the test conditions. The newly developed meshed CB/PDMS electrodes have the potential to be used in a wide variety of both dry and wet environments including the challenge of obtaining ECG signals in salt water environments. PMID:26769718

  19. Prevalence of enterococcus species and their virulence genes in fresh water prior to and after storm events.

    PubMed

    Sidhu, J P S; Skelly, E; Hodgers, L; Ahmed, W; Li, Y; Toze, S

    2014-01-01

    Enterococcus spp. isolates (n = 286) collected from six surface water bodies in subtropical Brisbane, Australia, prior to and after storm events, were identified to species level and tested for the presence of seven clinically important virulence genes (VGs). Enterococcus faecalis (48%), Enterococcus faecium (14%), Enterococcus mundtii (13%), and Enterococcus casseliflavus (13%) were frequently detected at all sites. The frequency of E. faecium occurrence increased from 6% in the dry period to 18% after the wet period. The endocarditis antigen (efaA), gelatinase (gelE), collagen-binding protein (ace), and aggregation substance (asa1) were detected in 61%, 43%, 43%, and 23% of Enterococcus isolates, respectively. The chances of occurrence of ace, gelE, efaA, and asa1 genes in E. faecalis were found to be much higher compared to the other Enterococcus spp. The observed odds ratio of occurrence of ace and gelE genes in E. faecalis was much higher at 7.96 and 6.40 times, respectively. The hyl gene was 3.84 times more likely to be detected in E. casseliflavus. The presence of multiple VGs in most of the E. faecalis isolates underscores the importance of E. faecalis as a reservoir of VGs in the fresh water aquatic environment. Consequently, if contaminated surface water is to be used for production of potable and nonpotable water some degree of treatment depending upon intended use such as detention in basins prior to use or chlorination is required.

  20. Biological responses to the chemical recovery of acidified fresh waters in the UK.

    PubMed

    Monteith, D T; Hildrew, A G; Flower, R J; Raven, P J; Beaumont, W R B; Collen, P; Kreiser, A M; Shilland, E M; Winterbottom, J H

    2005-09-01

    We report biological changes at several UK Acid Waters Monitoring Network lakes and streams that are spatially consistent with the recovery of water chemistry induced by reductions in acid deposition. These include trends toward more acid-sensitive epilithic diatom and macroinvertebrate assemblages, an increasing proportional abundance of macroinvertebrate predators, an increasing occurrence of acid-sensitive aquatic macrophyte species, and the recent appearance of juvenile (<1 year old) brown trout in some of the more acidic flowing waters. Changes are often shown to be directly linked to annual variations in acidity. Although indicative of biological improvement in response to improving water chemistry, "recovery" in most cases is modest and very gradual. While specific ecological recovery endpoints are uncertain, it is likely that physical and biotic interactions are influencing the rate of recovery of certain groups of organisms at particular sites.

  1. Biological responses to the chemical recovery of acidified fresh waters in the UK.

    PubMed

    Monteith, D T; Hildrew, A G; Flower, R J; Raven, P J; Beaumont, W R B; Collen, P; Kreiser, A M; Shilland, E M; Winterbottom, J H

    2005-09-01

    We report biological changes at several UK Acid Waters Monitoring Network lakes and streams that are spatially consistent with the recovery of water chemistry induced by reductions in acid deposition. These include trends toward more acid-sensitive epilithic diatom and macroinvertebrate assemblages, an increasing proportional abundance of macroinvertebrate predators, an increasing occurrence of acid-sensitive aquatic macrophyte species, and the recent appearance of juvenile (<1 year old) brown trout in some of the more acidic flowing waters. Changes are often shown to be directly linked to annual variations in acidity. Although indicative of biological improvement in response to improving water chemistry, "recovery" in most cases is modest and very gradual. While specific ecological recovery endpoints are uncertain, it is likely that physical and biotic interactions are influencing the rate of recovery of certain groups of organisms at particular sites. PMID:15944042

  2. Phosphate adsorption by lanthanum modified bentonite clay in fresh and brackish water.

    PubMed

    Reitzel, Kasper; Andersen, Frede Ø; Egemose, Sara; Jensen, Henning S

    2013-05-15

    Effects of pH, alkalinity and conductivity on the adsorption of soluble reactive phosphorus (SRP) onto lanthanum (La) modified bentonite clay (Phoslock(®)) were investigated in laboratory experiments using eight different types of filtered water representing freshwater with low and normal alkalinity and brackish water with high alkalinity. Different dose ratios (0-200; w/w) of Phoslock(®):P were applied to determine the maximum P binding capacity of Phoslock(®) at SRP concentrations typical of those of sediment pore water. The 100:1 Phoslock(®:)P dose ratio, recommended by the manufacturer, was tested with 12 days exposure time and generally found to be insufficient at binding whole target SRP pool. The ratio performed best in the soft water from Danish Lake Hampen and less good in the hard water from Danish Lake Langesø and in brackish water. The explanation may be an observed negative relationship between alkalinity and the SRP binding capacity of Phoslock(®). A comparative study of Lake Hampen and Lake Langesø suggested that the recorded differences in P adsorption between the two lakes could be attributed to a more pronounced dispersion of Phoslock(®) in the soft water of Lake Hampen, leading to higher fractions of dissolved (<0.2 μm) La and of La in fine particles. In the same two lakes, pH affected the SRP binding of Phoslock(®) negatively at a pH level above 8.1, the effect being reversible, however. The negative pH effect was most significant in hard water Lake Langesø, most likely because of higher [Formula: see text] concentrations.

  3. Effect of Disinfectants on Preventing the Cross-Contamination of Pathogens in Fresh Produce Washing Water.

    PubMed

    Banach, Jennifer L; Sampers, Imca; Van Haute, Sam; van der Fels-Klerx, H J Ine

    2015-07-23

    The potential cross-contamination of pathogens between clean and contaminated produce in the washing tank is highly dependent on the water quality. Process wash water disinfectants are applied to maintain the water quality during processing. The review examines the efficacy of process wash water disinfectants during produce processing with the aim to prevent cross-contamination of pathogens. Process wash water disinfection requires short contact times so microorganisms are rapidly inactivated. Free chlorine, chlorine dioxide, ozone, and peracetic acid were considered suitable disinfectants. A disinfectant's reactivity with the organic matter will determine the disinfectant residual, which is of paramount importance for microbial inactivation and should be monitored in situ. Furthermore, the chemical and worker safety, and the legislative framework will determine the suitability of a disinfection technique. Current research often focuses on produce decontamination and to a lesser extent on preventing cross-contamination. Further research on a sanitizer's efficacy in the washing water is recommended at the laboratory scale, in particular with experimental designs reflecting industrial conditions. Validation on the industrial scale is warranted to better understand the overall effects of a sanitizer.

  4. Effect of Disinfectants on Preventing the Cross-Contamination of Pathogens in Fresh Produce Washing Water

    PubMed Central

    Banach, Jennifer L.; Sampers, Imca; Van Haute, Sam; van der Fels-Klerx, H.J. (Ine)

    2015-01-01

    The potential cross-contamination of pathogens between clean and contaminated produce in the washing tank is highly dependent on the water quality. Process wash water disinfectants are applied to maintain the water quality during processing. The review examines the efficacy of process wash water disinfectants during produce processing with the aim to prevent cross-contamination of pathogens. Process wash water disinfection requires short contact times so microorganisms are rapidly inactivated. Free chlorine, chlorine dioxide, ozone, and peracetic acid were considered suitable disinfectants. A disinfectant’s reactivity with the organic matter will determine the disinfectant residual, which is of paramount importance for microbial inactivation and should be monitored in situ. Furthermore, the chemical and worker safety, and the legislative framework will determine the suitability of a disinfection technique. Current research often focuses on produce decontamination and to a lesser extent on preventing cross-contamination. Further research on a sanitizer’s efficacy in the washing water is recommended at the laboratory scale, in particular with experimental designs reflecting industrial conditions. Validation on the industrial scale is warranted to better understand the overall effects of a sanitizer. PMID:26213953

  5. Effect of Disinfectants on Preventing the Cross-Contamination of Pathogens in Fresh Produce Washing Water.

    PubMed

    Banach, Jennifer L; Sampers, Imca; Van Haute, Sam; van der Fels-Klerx, H J Ine

    2015-08-01

    The potential cross-contamination of pathogens between clean and contaminated produce in the washing tank is highly dependent on the water quality. Process wash water disinfectants are applied to maintain the water quality during processing. The review examines the efficacy of process wash water disinfectants during produce processing with the aim to prevent cross-contamination of pathogens. Process wash water disinfection requires short contact times so microorganisms are rapidly inactivated. Free chlorine, chlorine dioxide, ozone, and peracetic acid were considered suitable disinfectants. A disinfectant's reactivity with the organic matter will determine the disinfectant residual, which is of paramount importance for microbial inactivation and should be monitored in situ. Furthermore, the chemical and worker safety, and the legislative framework will determine the suitability of a disinfection technique. Current research often focuses on produce decontamination and to a lesser extent on preventing cross-contamination. Further research on a sanitizer's efficacy in the washing water is recommended at the laboratory scale, in particular with experimental designs reflecting industrial conditions. Validation on the industrial scale is warranted to better understand the overall effects of a sanitizer. PMID:26213953

  6. Direct-contact condensers for open-cycle OTEC applications: Model validation with fresh water experiments for structured packings

    NASA Astrophysics Data System (ADS)

    Bharathan, D.; Parsons, B. K.; Althof, J. A.

    1988-10-01

    The objective of the reported work was to develop analytical methods for evaluating the design and performance of advanced high-performance heat exchangers for use in open-cycle thermal energy conversion (OC-OTEC) systems. This report describes the progress made on validating a one-dimensional, steady-state analytical computer of fresh water experiments. The condenser model represents the state of the art in direct-contact heat exchange for condensation for OC-OTEC applications. This is expected to provide a basis for optimizing OC-OTEC plant configurations. Using the model, we examined two condenser geometries, a cocurrent and a countercurrent configuration. This report provides detailed validation results for important condenser parameters for cocurrent and countercurrent flows. Based on the comparisons and uncertainty overlap between the experimental data and predictions, the model is shown to predict critical condenser performance parameters with an uncertainty acceptable for general engineering design and performance evaluations.

  7. Application of the distributed activation energy model to the kinetic study of pyrolysis of the fresh water algae Chlorococcum humicola.

    PubMed

    Kirtania, Kawnish; Bhattacharya, Sankar

    2012-03-01

    Apart from capturing carbon dioxide, fresh water algae can be used to produce biofuel. To assess the energy potential of Chlorococcum humicola, the alga's pyrolytic behavior was studied at heating rates of 5-20K/min in a thermobalance. To model the weight loss characteristics, an algorithm was developed based on the distributed activation energy model and applied to experimental data to extract the kinetics of the decomposition process. When the kinetic parameters estimated by this method were applied to another set of experimental data which were not used to estimate the parameters, the model was capable of predicting the pyrolysis behavior, in the new set of data with a R(2) value of 0.999479. The slow weight loss, that took place at the end of the pyrolysis process, was also accounted for by the proposed algorithm which is capable of predicting the pyrolysis kinetics of C. humicola at different heating rates.

  8. Epitheliocystis in Atlantic salmon, Salmo salar L., farmed in fresh water in Ireland is associated with 'Candidatus Clavochlamydia salmonicola' infection.

    PubMed

    Mitchell, S O; Steinum, T; Rodger, H; Holland, C; Falk, K; Colquhoun, D J

    2010-08-01

    Intracellular inclusions containing chlamydia-like organisms are frequently observed in the gill epithelial cells of Atlantic salmon, Salmo salar L., cultured in fresh water in Ireland. In this study, the causative agent was identified in four separate freshwater sites, using 16s rRNA sequencing, as 'Candidatus Clavochlamydia salmonicola'. Histopathology and real-time (RT) PCR were used to further assess infections. The prevalence of infection ranged from 75-100% between sites and infection intensity was highly variable. No significant lesions were associated with these infections. As a diagnostic tool, RT-PCR proved marginally more sensitive than histopathology. The fate of 'Candidatus Clavochlamydia salmonicola' in Atlantic salmon post-seawater transfer was investigated in a 12-week marine longitudinal study. Both RT-PCR and histopathological examination indicate that the organism disappears from the gills 4-6 weeks post-transfer.

  9. Fresh water blue green algae from three agro-climatic zones of Uttar Pradesh, India: distribution pattern with seasonal variation.

    PubMed

    Dwivedi, S; Misra, P K; Rai, U N; Tripathi, R D; Suseela, M R; Sinha, S; Baghel, V S; Pal, Amit; Dwivedi, C P

    2005-01-01

    The paper deals with 45 species of 21 genera of fresh water blue green algae (BGA) from three different agro-climatic zones of Uttar Pradesh. Samples were collected from different habitats varying in physico-chemical properties. Out of 45 species, 13 species belonged to order Chroococcales, 31 to order Nostocales, while only 1 species belonged to order Stigonimatales i.e. Fischerella mucicola. The physico-chemical parameters like pH, temperature, dissolved oxygen, electrical conductivity, nitrate, nitrite and rainfall play an important role in the periodicity of BGA. A positive correlation was found between dissolved oxygen (DO) of different ponds and species diversity, except in the case of western region of Uttar Pradesh (Farukhabad and Mahoba districts) where a positive correlation was found in electrical conductivity and total dissolved solids.

  10. Direct-contact condensers for open-cycle OTEC applications: Model validation with fresh water experiments for structured packings

    SciTech Connect

    Bharathan, D.; Parsons, B.K.; Althof, J.A.

    1988-10-01

    The objective of the reported work was to develop analytical methods for evaluating the design and performance of advanced high-performance heat exchangers for use in open-cycle thermal energy conversion (OC-OTEC) systems. This report describes the progress made on validating a one-dimensional, steady-state analytical computer of fresh water experiments. The condenser model represents the state of the art in direct-contact heat exchange for condensation for OC-OTEC applications. This is expected to provide a basis for optimizing OC-OTEC plant configurations. Using the model, we examined two condenser geometries, a cocurrent and a countercurrent configuration. This report provides detailed validation results for important condenser parameters for cocurrent and countercurrent flows. Based on the comparisons and uncertainty overlap between the experimental data and predictions, the model is shown to predict critical condenser performance parameters with an uncertainty acceptable for general engineering design and performance evaluations. 33 refs., 69 figs., 38 tabs.

  11. Determination of dissolved boron in fresh, estuarine, and geothermal waters by d.c. argon-plasma emission spectrometry

    USGS Publications Warehouse

    Ball, J.W.; Thompson, J.M.; Jenne, E.A.

    1978-01-01

    A d.c. argon-plasma emission spectrometer is used to determine dissolved boron in natural (fresh and estuarine) water samples. Concentrations ranged from 0.02 to 250 mg l-1. The emission-concentration function is linear from 0.02 to 1000 mg l-1. Achievement of a relative standard deviation of ??? 3% requires frequent restandardization to offset sensitivity changes. Dilution may be necessary to overcome high and variable electron density caused by differences in alkali-metal content and to avoid quenching of the plasma by high solute concentrations of sodium and other easily ionized elements. The proposed method was tested against a reference method and found to be more sensitive, equally or more precise and accurate, less subject to interferences, with a wider linear analytical range than the carmine method. Analyses of standard reference samples yielded results in all cases within one standard deviation of the means. ?? 1978.

  12. Influence of freshwater inflow on the inorganic nutrient and dissolved organic matter within coastal sea ice and underlying waters in the Gulf of Finland (Baltic Sea)

    NASA Astrophysics Data System (ADS)

    Granskog, Mats A.; Kaartokallio, Hermanni; Thomas, David N.; Kuosa, Harri

    2005-10-01

    A study was conducted to measure the biogeochemical characteristics of freshwater plumes underlying Baltic Sea land-fast ice, and the overlying sea ice. A 40-km long transect was conducted in the northern Baltic Sea in March 2003, following a freshwater plume from its source into the fully mixed open-sea area. The spreading of river outflow below the ice resulted in a well-stratified low-salinity surface layer further out than normally occurs in the open-water period. The freshwaters were high in dissolved organic matter (DOC, DON and CDOM), and inorganic nutrients (ammonium, nitrate and silicate), although the levels of phosphate were low. In general these parameters changed concurrently with salinity in such a way that mixing was conservative. The characteristics of the ice varied from the freshwater source to the open water, with increasing salinity and brine volumes (porosity) occurring in the more open-sea stations. Coinciding with the changes in ice properties there was an increase in sea-ice algal growth in the more marine stations along the transect. Biological activity in the ice was largely confined to bottom ice assemblages. In contrast to the conditions in the underlying water, no relationship between salinity, inorganic nutrients and organic matter was observed in the ice. In particular ammonium, phosphate, DOC and DON were present in excess of those levels predicted from the dilution curves, indicating the presence of considerable DOM production by ice assemblages, inorganic nutrient uptake and remineralization within the ice.

  13. Factors controlling the configuration of the fresh-saline water interface in the Dead Sea coastal aquifers: Synthesis of TDEM surveys and numerical groundwater modeling

    USGS Publications Warehouse

    Yechieli, Y.; Kafri, U.; Goldman, M.; Voss, C.I.

    2001-01-01

    TDEM (time domain electromagnetic) traverses in the Dead Sea (DS) coastal aquifer help to delineate the configuration of the interrelated fresh-water and brine bodies and the interface in between. A good linear correlation exists between the logarithm of TDEM resistivity and the chloride concentration of groundwater, mostly in the higher salinity range, close to that of the DS brine. In this range, salinity is the most important factor controlling resistivity. The configuration of the fresh-saline water interface is dictated by the hydraulic gradient, which is controlled by a number of hydrological factors. Three types of irregularities in the configuration of fresh-water and saline-water bodies were observed in the study area: 1. Fresh-water aquifers underlying more saline ones ("Reversal") in a multi-aquifer system. 2. "Reversal" and irregular residual saline-water bodies related to historical, frequently fluctuating DS base level and respective interfaces, which have not undergone complete flushing. A rough estimate of flushing rates may be obtained based on knowledge of the above fluctuations. The occurrence of salt beds is also a factor affecting the interface configuration. 3. The interface steepens towards and adjacent to the DS Rift fault zone. Simulation analysis with a numerical, variable-density flow model, using the US Geological Survey's SUTRA code, indicates that interface steep- ening may result from a steep water-level gradient across the zone, possibly due to a low hydraulic conductivity in the immediate vicinity of the fault.

  14. Acid-based balance and blood gas changes in the fresh water field crab, Barytelphusa guerini, on exposure to organic and inorganic lead

    SciTech Connect

    Tulasi, S.J.; Rao, J.V.R.

    1988-02-01

    The acid-base status of crustacean haemolymph depends on various environmental and physiological factors. Acid base status of the haemolymph is known to be influenced by temperature, salinity, strenuous activity and moulting. The studies on the acid-base regulation of the fresh water crabs are meager. The acid-base changes in fishes during environmental stress conditions like acid stress and zinc toxicity had been reported. But the effect of environmental pollutants like the heavy metals on the acid-base regulation of the fresh water crabs have not been previously reported. The haemolymph of the fresh water crab was found to accumulate high amounts of lead on exposure to organic and inorganic lead. Hence the present investigation has been undertaken to study the haemolymph acid-base status on exposure to subtoxic levels of organic and inorganic lead.

  15. How Famine Started in Somalia: A Simple Model of Fresh Water Use

    NASA Astrophysics Data System (ADS)

    Gustafson, K. C.; Motesharrei, S.; Miralles-Wilhelm, F. R.; Kalnay, E.; Rivas, J.; Freshwater Modeling Team

    2011-12-01

    Water is the origin of life on our planet and therefore the most valued and essential natural resource for sustaining life on earth. Human uses of freshwater include not only drinking, washing, and other daily domestic activities, but also manufacturing, energy production, agriculture, aquaculture, etc. Though our planet is 97% water, only a minute portion of this is available as freshwater to be used for anthropogenic necessities and the rate at which the natural system can filter and replenish the freshwater supply cannot compete with the rate of demand. That is why special attention must be given to availability of freshwater at present time and in future. We constructed a fairly elementary model of the water cycle while we were working on a more sophisticated water model that includes several additional details. Upon introducing data from different regions of the world (including United States) into our simple model and running simulations, we can gain insight into the future of water sources and availability of freshwater. In particular, we are able to simulate how drought can result in famine, a catastrophe currently taking place in certain areas of Somalia.

  16. Theoretical analysis of injecting the compressed air through a defensive well into aquifer aimed to separate between polluted and fresh water

    NASA Astrophysics Data System (ADS)

    Boger, M.; Ravina, I.

    2012-12-01

    Injecting a compressed air, through a well, located between the sea or a polluted lake and fresh ground water, creates a "hydraulic barrier" that prevents their mixing. Steady influx of air to a saturated soil produces a pressure gradient from the well and replacement of water by air, hence the interface between air and water increases. After the compression process is stopped, the soil pores are filled with air, so that saturated soil becomes unsaturated with a decreased conductivity. Creating such a barrier, first by the air pressure and second by blocking of the pores, is welcomed at the interface sea-fresh water area, for example. It prevents the loss of fresh water to the sea and it decreases sea water movement into the aquifer. Another positive effect of the air injection is the air flow through unsaturated zone, above the ground water, that decreases polluted water down-seepage from the surface thus defending the fresh ground water against pollution. The regular water well or special drilled one will be used as defensive well. The radius of defensive well can be smaller than the one of the water well. The explanation of the defensive well exploitation in the field for one and multi layer aquifers is presented. Analytical evaluations of the pressure loss and shape of the air-water interfaces in saturated soil are presented for: (a) steady air flow for a one layer aquifer and for a three layer one (leaky aquifer case), (b) transient air flow for a one layer aquifer. It is shown that the shape of air-water interfaces is generally an inverted cone, where the decrease of air pressure in the aquifer with the distance from the well is approximately logarithmic. The necessary pressure to create the effective air flow in the aquifer is only about tens percent higher than static water pressure in the well.

  17. Extensive Treatment System For Recycling Water For Flushing Fresh Manure And Recovering Nutrients

    NASA Astrophysics Data System (ADS)

    Morand, Philippe; Robin, Paul; Escande, Aurélie; Picot, Bernadette; Pourcher, Anne-Marie; Jiangping, Qiu; Yinsheng, Li; Hamon, Gwenn; Amblard, Charlotte; Luth, Fievet, Sébastien; Oudart, Didier; Le Quéré, Camille Pain; Cluzeau, Daniel; Landrain, Brigitte

    2010-11-01

    From preliminary researches on a pilot scale, a complete demonstration plant was built to treat the effluents of a 30 pregnant sow's piggery. It includes a screen, a vermifilter, a macrophyte lagooning, and a complementary water storage pond; the recycled water is used for flushing, and rainfall is collected to compensate for evapotranspiration. After functioning in 2008 and 2009, it was showed that, during the warm season, the whole plant produced an effluent suitable for flushing, where the concentration decrease was over 70% for the phosphorus and potassium, 95% for the COD and nitrogen, 99.8% for endocrine disruptors (estrogenic activity), and 99.99% for pathogenic micro-organisms. During the cold season, the dilution by the rain water and the treatment effect of the constructed wetlands lead to similar results. Nevertheless, for this season, suitable floating macrophytes that will cover the lagoons remain to be settled.

  18. Reference Inflow Characterization for River Resource Reference Model (RM2)

    SciTech Connect

    Neary, Vincent S

    2011-12-01

    Sandia National Laboratory (SNL) is leading an effort to develop reference models for marine and hydrokinetic technologies and wave and current energy resources. This effort will allow the refinement of technology design tools, accurate estimates of a baseline levelized cost of energy (LCoE), and the identification of the main cost drivers that need to be addressed to achieve a competitive LCoE. As part of this effort, Oak Ridge National Laboratory was charged with examining and reporting reference river inflow characteristics for reference model 2 (RM2). Published turbulent flow data from large rivers, a water supply canal and laboratory flumes, are reviewed to determine the range of velocities, turbulence intensities and turbulent stresses acting on hydrokinetic technologies, and also to evaluate the validity of classical models that describe the depth variation of the time-mean velocity and turbulent normal Reynolds stresses. The classical models are found to generally perform well in describing river inflow characteristics. A potential challenge in river inflow characterization, however, is the high variability of depth and flow over the design life of a hydrokinetic device. This variation can have significant effects on the inflow mean velocity and turbulence intensity experienced by stationary and bottom mounted hydrokinetic energy conversion devices, which requires further investigation, but are expected to have minimal effects on surface mounted devices like the vertical axis turbine device designed for RM2. A simple methodology for obtaining an approximate inflow characterization for surface deployed devices is developed using the relation umax=(7/6)V where V is the bulk velocity and umax is assumed to be the near-surface velocity. The application of this expression is recommended for deriving the local inflow velocity acting on the energy extraction planes of the RM2 vertical axis rotors, where V=Q/A can be calculated given a USGS gage flow time

  19. Climate change impacts on reservoir inflow in the United States

    NASA Astrophysics Data System (ADS)

    Naz, B. S.; Kao, S. C.; Ashfaq, M.; Gangrade, S.; Mei, R.; Ratogi, D.

    2014-12-01

    This study describes the impacts of projected climate change on reservoir inflows across the United States. For this purpose, we focused on several large U.S. reservoirs where inflow to reservoir is non-regulated (i.e. unaffected by human influence or upstream regulation) and also have long-term streamflow observations. We first simulated the 1980-2012 historic hydrologic conditions using the marco-scale Variable Infiltration Capacity (VIC) hydrological model at 1/24th degree grid cell resolution. The VIC-routing model was then used to simulate and compare with observed streamflow at the selected reservoir inflow locations. To project the climate change effects on reservoir inflows, the VIC model was then driven by 12-member dynamically downscaled and bias corrected meteorological forcings ensemble, which was generated by using 12 selected Global Climate Models from Coupled Model Intercomparison Project Phase-5 as an initial and boundary conditions in a regional climate model, RegCM4. Each set of dynamical downscaling experiment was carried out at 18 km horizontal grid spacing over the continental U.S. and parts of Canada and Mexico, and consisted of 41 years in the historic period (1965-2005) and 41 years in the near-term future period (2010-2050) under the Representative Concentration Pathway 8.5. To better understand the impact of projected future changes in temperature and precipitation on shifts in streamflow discharge and distribution, and its implications on reservoir storage, temporal trends in reservoir inflows were also explored. Furthermore, hydrologic sensitivities experiments were conducted to identify the factors affecting the streamflow response to changes in precipitation and temperature. This study provides estimates for changes in the reservoir inflows over the next several decades in response to potential climate variations that can be used for optimized water supply management in the downstream areas.

  20. Electroanalytical techniques in the environmental monitoring of fresh-water ecosystems

    SciTech Connect

    Smolyakov, B.S.; Nemirovskii, A.M.; Kokovkin, V.V.

    1995-10-01

    In this work, in order to develop the analytical support of the environmental monitoring of freshwater ecosystems, the authors used a set of electrochemical techniques for assessing the composition and some integral characteristics of water. Basic attention was paid to adapting these techniques to field measurements and instruments.

  1. THE REDUCTIVE TRANSFORMATION OF PERCHLORATE IN A FRESH WATER SEDIMENT: LABORATORY BATCH STUDIES

    EPA Science Inventory

    Perchlorate is widely used as a propellant in solid rocket fuel, and has recently been found in ground, surface, and drinking water, in many cases above the interim action level of 18 ppb. Perchlorate is recalcitrant to chemical reduction, however, studies of perchlorate in pure ...

  2. THE REDUCTIVE TRANSFORMATION OF PERCHLORATE IN A FRESH WATER SEDIMENT: LABORATORY BATCH STUDIES.

    EPA Science Inventory

    Perchlorate is widely used as a propellant in solid rocket fuel, and has recently been found in ground, surface, and drinking water, in many cases above the interim action level of 18 ppb. Perchlorate is recalcitrant to chemical reduction, however, studies of perchlorate in pure ...

  3. Sea snakes (Laticauda spp.) require fresh drinking water: implication for the distribution and persistence of populations.

    PubMed

    Lillywhite, Harvey B; Babonis, Leslie S; Sheehy, Coleman M; Tu, Ming-Chung

    2008-01-01

    Dehydration and procurement of water are key problems for vertebrates that have secondarily invaded marine environments. Sea snakes and other marine reptiles are thought to remain in water balance without consuming freshwater, owing to the ability of extrarenal salt glands to excrete excess salts obtained either from prey or from drinking seawater directly. Contrary to this long-standing dogma, we report that three species of sea snake actually dehydrate in marine environments. We investigated dehydration and drinking behaviors in three species of amphibious sea kraits (Laticauda spp.) representing a range of habits from semiterrestrial to very highly marine. Snakes that we dehydrated either in air or in seawater refused to drink seawater but drank freshwater or very dilute brackish water (10%-30% seawater) to remain in water balance. We further show that Laticauda spp. can dehydrate severely in the wild and are far more abundant at sites where there are sources of freshwater. A more global examination of all sea snakes demonstrates that species richness correlates positively with mean annual precipitation within the Indo-West Pacific tropical region. The dependence of Laticauda spp. on freshwater might explain the characteristically patchy distributions of these reptiles and is relevant to understanding patterns of extinctions and possible future responses to changes in precipitation related to global warming. In particular, metapopulation dynamics of the Laticauda group of sea snakes are expected to change in relation to projected reductions of tropical dry-season precipitation.

  4. Evaluation Of Selected Sorption Materials For Capping Mercury-Contaminated Fresh Water Sediments

    EPA Science Inventory

    Fate and transport of mercury (Hg) and methylmercury (MeHg) within the aquatic environment involves many complex and interconnected pathways. MeHg is formed mainly at the sediment-water interface, just below which there is a transition from oxic to anoxic conditions. The format...

  5. Buffer capacities of fresh water lakes sensitive to acid rain deposition

    SciTech Connect

    Faust, S.D.; McIntosh, A.

    1983-01-01

    The Van Slyke definition of buffer capacity, the increment of a strong base or strong acid that causes an incremental change in the pH value of water, is better than total alkalinity for defining a water's resistance to acid rain. This Van Slyke value, designated by beta, shows a peak at pH 6.3 for the bicarbonate-carbonate pair, indicating that the effect of acid rain on the pH and alkalinity of natural waters is not deleterious until this peak is traversed. A beta value of zero indicates a dead water with no capacity to neutralize acid. The beta values, pH and total alkalinity of lakes, reservoirs, and streams in New Jersey are given. Data clearly show that pH and alkalinity alone cannot determine buffer capacity. For example: Fairview Lake (pH of 5.5 and alkalinity of 10.2 mg per liter) has a beta value 11 times that of Clyde Potts Reservoir (pH of 7.3, alkalinity of 8.1 mg per liter). 3 references, 1 figure, 1 table.

  6. ARE MACRO AND MICRO ENVIRONMENT AFFECTING MANAGEMENT OF FRESH WATER RESOURCES? A CASE FROM IRAN WITH PESTLE ANALYSIS

    PubMed Central

    Atighechian, Golrokh; Maleki, Mohammadreza; Aryankhesal, Aidin; Jahangiri, Katayoun

    2016-01-01

    Introduction: Oil spill in fresh water can affect ecological processes and accordingly it can influence human health. Iran, due to having 58.8 % of the world oil reserves, is highly vulnerable to water contamination by oil products. Aim: The aim of this study was to determine environmental factors affecting the management of the oil spill into one of the river in Iran using the PESTLE analysis. Material and methods: This was a qualitative case study conducted in 2015 on an oil spill incident in Iran and its roots from a disaster management approach. Semi-structured interviews were conducted for data collection. Seventy managers and staffs with those responsible or involved in oil spill incident management were recruited to the study. Qualitative content analysis approach was employed for the data analysis. Document analysis was used to collect additional information. Results: Findings of the present study indicated that different factors affected the management of the event of oil spill onto one of the central river and consequently the management of drink water resources. Using this analysis, managers can plan for such events and develop scenarios for them to have better performance for the future events. PMID:27698608

  7. Toxicity of neem pesticides on a fresh water loach, Lepidocephalichthys guntea (Hamilton Buchanan) of Darjeeling district in West Bengal.

    PubMed

    Mondal, Debashri; Barat, Sudip; Mukhopadhyay, M K

    2007-01-01

    Static renewal bioassay tests were conducted to evaluate the acute toxicity of two neem based biopesticides, applied widely on tea plantation namely, Nimbecidine and Neem Gold either separately as well as, in combination to the fingerlings (mean body length- 4.46 +/- 0.15 cm; mean body weight- 0.49 +/- 0.15g) of a fresh water loach, Lepidocephalichthys guntea (Hamilton Buchanan) acclimatized to laboratory conditions prior to experiment. The 96 hours LC50 values for Nimbecidine and Neem Gold and the combination of the two were 0.0135 mgl(-1), 0.0525mgl(-1) and 0.0396 mgl(-1), respectively. The regular water quality analysis showed, that with increasing doses of biopesticides, dissolved oxygen level was lower and other parameters like pH, free carbon dioxide, total alkalinity total hardness, chloride ions of water increased. The fish under toxicity stress suffered several abnormalities such as erratic and rapid movement, body imbalance and surface floating responding proportionately to the increase in concentrations of the toxicant biopesticides. The 96 hours LC50 values proved Nimbecidine more toxic than Neem Gold and the combination of the two biopesticides.

  8. Postharvest sour cherry quality and safety maintenance by exposure to Hot- water or treatment with fresh Aloe vera gel.

    PubMed

    Ravanfar, Rahele; Niakousari, Mehrdad; Maftoonazad, Neda

    2014-10-01

    Iranian sour cherries (Prunus cerasus) were coated with fresh Aloe vera gel or treated with hot water (40 ± 2 °C) for 2 min and stored for 17 days at 4 ± 1 °C. The physicochemical characteristics of gel coated and hot water treated samples were compared with untreated fruit during the cold storage period. Untreated fruit showed increased respiration rate, rapid weight loss and colour change, accelerated aging and ripening. On the contrary, sour cherries, particularly those coated with gel significantly delayed the above mentioned parameters allowing a fruit storability extension. The sensory analysis in both treatments revealed beneficial effects in terms of delaying dehydration, maintenance of fruit visual aspect without any detrimental effect on taste, aroma or flavours. Consequently, Aloe vera gel coating and immersion in hot water maintained the properties during postharvest storage of sour cherries and could be introduced as two valuable, simple and non-contaminating treatments. PMID:25328241

  9. ARE MACRO AND MICRO ENVIRONMENT AFFECTING MANAGEMENT OF FRESH WATER RESOURCES? A CASE FROM IRAN WITH PESTLE ANALYSIS

    PubMed Central

    Atighechian, Golrokh; Maleki, Mohammadreza; Aryankhesal, Aidin; Jahangiri, Katayoun

    2016-01-01

    Introduction: Oil spill in fresh water can affect ecological processes and accordingly it can influence human health. Iran, due to having 58.8 % of the world oil reserves, is highly vulnerable to water contamination by oil products. Aim: The aim of this study was to determine environmental factors affecting the management of the oil spill into one of the river in Iran using the PESTLE analysis. Material and methods: This was a qualitative case study conducted in 2015 on an oil spill incident in Iran and its roots from a disaster management approach. Semi-structured interviews were conducted for data collection. Seventy managers and staffs with those responsible or involved in oil spill incident management were recruited to the study. Qualitative content analysis approach was employed for the data analysis. Document analysis was used to collect additional information. Results: Findings of the present study indicated that different factors affected the management of the event of oil spill onto one of the central river and consequently the management of drink water resources. Using this analysis, managers can plan for such events and develop scenarios for them to have better performance for the future events.

  10. Toxicity of neem pesticides on a fresh water loach, Lepidocephalichthys guntea (Hamilton Buchanan) of Darjeeling district in West Bengal.

    PubMed

    Mondal, Debashri; Barat, Sudip; Mukhopadhyay, M K

    2007-01-01

    Static renewal bioassay tests were conducted to evaluate the acute toxicity of two neem based biopesticides, applied widely on tea plantation namely, Nimbecidine and Neem Gold either separately as well as, in combination to the fingerlings (mean body length- 4.46 +/- 0.15 cm; mean body weight- 0.49 +/- 0.15g) of a fresh water loach, Lepidocephalichthys guntea (Hamilton Buchanan) acclimatized to laboratory conditions prior to experiment. The 96 hours LC50 values for Nimbecidine and Neem Gold and the combination of the two were 0.0135 mgl(-1), 0.0525mgl(-1) and 0.0396 mgl(-1), respectively. The regular water quality analysis showed, that with increasing doses of biopesticides, dissolved oxygen level was lower and other parameters like pH, free carbon dioxide, total alkalinity total hardness, chloride ions of water increased. The fish under toxicity stress suffered several abnormalities such as erratic and rapid movement, body imbalance and surface floating responding proportionately to the increase in concentrations of the toxicant biopesticides. The 96 hours LC50 values proved Nimbecidine more toxic than Neem Gold and the combination of the two biopesticides. PMID:17717997

  11. A new method for collection of nitrate from fresh water and the analysis of nitrogen and oxygen isotope ratios

    USGS Publications Warehouse

    Silva, S.R.; Kendall, C.; Wilkison, D.H.; Ziegler, A.C.; Chang, Cecily C.Y.; Avanzino, R.J.

    2000-01-01

    A new method for concentrating nitrate from fresh waters for ??15N and ??18O analysis has been developed and field-tested for four years. The benefits of the method are: (1) elimination of the need to transport large volumes of water to the laboratory for processing; (2) elimination of the need for hazardous preservatives; and (3) the ability to concentrate nitrate from fresh waters. Nitrate is collected by, passing the water-sample through pre-filled, disposable, anion exchanging resin columns in the field. The columns are subsequently transported to the laboratory where the nitrate is extracted, converted to AgNO3 and analyzed for its isotope composition. Nitrate is eluted from the anion exchange columns with 15 ml of 3 M HCl. The nitrate-bearing acid eluant is neutralized with Ag2O, filtered to remove the AgCl precipitate, then freeze-dried to obtain solid AgNO3, which is then combusted to N2 in sealed quartz tubes for ?? 15N analysis. For ?? 18O analysis, aliquots of the neutralized eluant are processed further to remove non-nitrate oxygen-bearing anions and dissolved organic matter. Barium chloride is added to precipitate sulfate and phosphate; the solution is then filtered, passed through a cation exchange column to remove excess Ba2+, re-neutralized with Ag2O, filtered, agitated with activated carbon to remove dissolved organic matter and freeze-dried. The resulting AgNO3 is combusted with graphite in a closed tube to produce CO2, which is cryogenically purified and analyzed for its oxygen isotope composition. The 1?? analytical precisions for ??15N and ??18O are ?? 0.05%o and ??0.5???, respectively, for solutions of KNO3 standard processed through the entire column procedure. High concentrations of anions in solution can interfere with nitrate adsorption on the anion exchange resins, which may result in isotope fractionation of nitrogen and oxygen (fractionation experiments were conducted for nitrogen only; however, fractionation for oxygen is expected

  12. A new method for collection of nitrate from fresh water and the analysis of nitrogen and oxygen isotope ratios

    NASA Astrophysics Data System (ADS)

    Silva, S. R.; Kendall, C.; Wilkison, D. H.; Ziegler, A. C.; Chang, C. C. Y.; Avanzino, R. J.

    2000-02-01

    A new method for concentrating nitrate from fresh waters for δ15N and δ18O analysis has been developed and field-tested for four years. The benefits of the method are: (1) elimination of the need to transport large volumes of water to the laboratory for processing; (2) elimination of the need for hazardous preservatives; and (3) the ability to concentrate nitrate from fresh waters. Nitrate is collected by, passing the water-sample through pre-filled, disposable, anion exchanging resin columns in the field. The columns are subsequently transported to the laboratory where the nitrate is extracted, converted to AgNO 3 and analyzed for its isotope composition. Nitrate is eluted from the anion exchange columns with 15 ml of 3 M HCl. The nitrate-bearing acid eluant is neutralized with Ag 2O, filtered to remove the AgCl precipitate, then freeze-dried to obtain solid AgNO 3, which is then combusted to N 2 in sealed quartz tubes for δ15N analysis. For δ18O analysis, aliquots of the neutralized eluant are processed further to remove non-nitrate oxygen-bearing anions and dissolved organic matter. Barium chloride is added to precipitate sulfate and phosphate; the solution is then filtered, passed through a cation exchange column to remove excess Ba 2+, re-neutralized with Ag 2O, filtered, agitated with activated carbon to remove dissolved organic matter and freeze-dried. The resulting AgNO 3 is combusted with graphite in a closed tube to produce CO 2, which is cryogenically purified and analyzed for its oxygen isotope composition. The 1 σ analytical precisions for δ15N and δ18O are ±0.05‰ and ±0.5‰, respectively, for solutions of KNO 3 standard processed through the entire column procedure. High concentrations of anions in solution can interfere with nitrate adsorption on the anion exchange resins, which may result in isotope fractionation of nitrogen and oxygen (fractionation experiments were conducted for nitrogen only; however, fractionation for oxygen is

  13. An integrated closed system for fish-plankton aquaculture in Amazonian fresh water.

    PubMed

    Gilles, S; Ismiño, R; Sánchez, H; David, F; Núñez, J; Dugué, R; Darias, M J; Römer, U

    2014-08-01

    A prototype of an integrated closed system for fish-plankton aquaculture was developed in Iquitos (Peruvian Amazonia) in order to cultivate the Tiger Catfish, Pseudoplatystoma punctifer (Castelnau, 1855). This freshwater recirculating system consisted of two linked sewage tanks with an intensive rearing unit (a cage) for P. punctifer placed in the first, and with a fish-plankton trophic chain replacing the filters commonly used in clear water closed systems. Detritivorous and zooplanktivorous fishes (Loricariidae and Cichlidae), maintained without external feeding in the sewage volume, mineralized organic matter and permitted the stabilization of the phytoplankton biomass. Water exchange and organic waste discharge were not necessary. In this paper we describe the processes undertaken to equilibrate this ecosystem: first the elimination of an un-adapted spiny alga, Golenkinia sp., whose proliferation was favored by the presence of a small rotifer, Trichocerca sp., and second the control of this rotifer proliferation via the introduction of two cichlid species, Acaronia nassa Heckel, 1840 and Satanoperca jurupari Heckel, 1840, in the sewage part. This favored some development of the green algae Nannochloris sp. and Chlorella sp. At that time we took the opportunity to begin a 3-month rearing test of P. punctifer. The mean specific growth rate and feed conversion ratio (FCR) of P. punctifer were 1.43 and 1.27, respectively, and the global FCR, including fish in the sewage part, was 1.08. This system has proven to be suitable for growing P. punctifer juveniles out to adult, and provides several practical advantages compared with traditional recirculating clear water systems, which use a combination of mechanical and biological filters and require periodic waste removal, leading to water and organic matter losses.

  14. An integrated closed system for fish-plankton aquaculture in Amazonian fresh water.

    PubMed

    Gilles, S; Ismiño, R; Sánchez, H; David, F; Núñez, J; Dugué, R; Darias, M J; Römer, U

    2014-08-01

    A prototype of an integrated closed system for fish-plankton aquaculture was developed in Iquitos (Peruvian Amazonia) in order to cultivate the Tiger Catfish, Pseudoplatystoma punctifer (Castelnau, 1855). This freshwater recirculating system consisted of two linked sewage tanks with an intensive rearing unit (a cage) for P. punctifer placed in the first, and with a fish-plankton trophic chain replacing the filters commonly used in clear water closed systems. Detritivorous and zooplanktivorous fishes (Loricariidae and Cichlidae), maintained without external feeding in the sewage volume, mineralized organic matter and permitted the stabilization of the phytoplankton biomass. Water exchange and organic waste discharge were not necessary. In this paper we describe the processes undertaken to equilibrate this ecosystem: first the elimination of an un-adapted spiny alga, Golenkinia sp., whose proliferation was favored by the presence of a small rotifer, Trichocerca sp., and second the control of this rotifer proliferation via the introduction of two cichlid species, Acaronia nassa Heckel, 1840 and Satanoperca jurupari Heckel, 1840, in the sewage part. This favored some development of the green algae Nannochloris sp. and Chlorella sp. At that time we took the opportunity to begin a 3-month rearing test of P. punctifer. The mean specific growth rate and feed conversion ratio (FCR) of P. punctifer were 1.43 and 1.27, respectively, and the global FCR, including fish in the sewage part, was 1.08. This system has proven to be suitable for growing P. punctifer juveniles out to adult, and provides several practical advantages compared with traditional recirculating clear water systems, which use a combination of mechanical and biological filters and require periodic waste removal, leading to water and organic matter losses. PMID:24849417

  15. Differential use of fresh water environments by wintering waterfowl of coastal Texas

    USGS Publications Warehouse

    White, D.H.; James, D.

    1978-01-01

    A comparative study of the environmental relationships among 14 species of wintering waterfowl was conducted at the Welder Wildlife Foundation, San Patricia County, near Sinton, Texas during the fall and early winter of 1973. Measurements of 20 environmental factors (social, vegetational, physical, and chemical) were subjected to multivariate statistical methods to determine certain niche characteristics and environmental relationships of waterfowl wintering in the aquatic community.....Each waterfowl species occupied a unique realized niche by responding to distinct combinations of environmental factors identified by principal component analysis. One percent confidence ellipses circumscribing the mean scores plotted for the first and second principal components gave an indication of relative niche width for each species. The waterfowl environments were significantly different interspecifically and water depth at feeding site and % emergent vegetation were most important in the separation. This was shown by subjecting the transformed data to multivariate analysis of variance with an associated step-down procedure. The species were distributed along a community cline extending from shallow water with abundant emergent vegetation to open deep water with little emergent vegetation of any kind. Four waterfowl subgroups were significantly separated along the cline, as indicated by one-way analysis of variance with Duncan?s multiple range test. Clumping of the bird species toward the middle of the available habitat hyperspace was shown in a plot of the principal component scores for the random samples and individual species.....Naturally occurring relationships among waterfowl were clarified using principal comcomponent analysis and related multivariate procedures. These techniques may prove useful in wetland management for particular groups of waterfowl based on habitat preferences.

  16. Geohydrology of the Laura fresh-water lens, Majuro atoll: a hydrogeochemical approach

    USGS Publications Warehouse

    Anthony, S.S.; Peterson, F.L.; MacKenzie, F.T.; Hamlin, S.N.

    1989-01-01

    The primary factors controlling the occurrence and flow of ground water in the leeward reef islet of Laura are (1) the depositional history of the upper hydrologic unit, which has resulted in a greater accumulation of low-permeability (fine-grained) sediments beneath the lagoon side of the island and a high- to low-permeability (coarse- to fine-grained sediment) gradation between the ocean and lagoon; and (2) the diagenetic history of the lower hydrologic unit, which has resulted in a highly permeable basement. -from Authors

  17. The comparative osmoregulatory ability of two water beetle genera whose species span the fresh-hypersaline gradient in inland waters (Coleoptera: Dytiscidae, Hydrophilidae).

    PubMed

    Pallarés, Susana; Arribas, Paula; Bilton, David T; Millán, Andrés; Velasco, Josefa

    2015-01-01

    A better knowledge of the physiological basis of salinity tolerance is essential to understanding the ecology and evolutionary history of organisms that have colonized inland saline waters. Coleoptera are amongst the most diverse macroinvertebrates in inland waters, including saline habitats; however, the osmoregulatory strategies they employ to deal with osmotic stress remain unexplored. Survival and haemolymph osmotic concentration at different salinities were examined in adults of eight aquatic beetle species which inhabit different parts of the fresh-hypersaline gradient. Studied species belong to two unrelated genera which have invaded saline waters independently from freshwater ancestors; Nebrioporus (Dytiscidae) and Enochrus (Hydrophilidae). Their osmoregulatory strategy (osmoconformity or osmoregulation) was identified and osmotic capacity (the osmotic gradient between the animal's haemolymph and the external medium) was compared between species pairs co-habiting similar salinities in nature. We show that osmoregulatory capacity, rather than osmoconformity, has evolved independently in these different lineages. All species hyperegulated their haemolymph osmotic concentration in diluted waters; those living in fresh or low-salinity waters were unable to hyporegulate and survive in hyperosmotic media (> 340 mosmol kg(-1)). In contrast, the species which inhabit the hypo-hypersaline habitats were effective hyporegulators, maintaining their haemolymph osmolality within narrow limits (ca. 300 mosmol kg(-1)) across a wide range of external concentrations. The hypersaline species N. ceresyi and E. jesusarribasi tolerated conductivities up to 140 and 180 mS cm(-1), respectively, and maintained osmotic gradients over 3500 mosmol kg(-1), comparable to those of the most effective insect osmoregulators known to date. Syntopic species of both genera showed similar osmotic capacities and in general, osmotic responses correlated well with upper salinity levels occupied by

  18. Concentration of radionuclides in fresh water fish downstream of Rancho Seco Nuclear Generating Plant

    SciTech Connect

    Noshkin, V.E.; Eagle, R.J.; Dawson, J.M.; Brunk, J.L.; Wong, X.M.

    1984-12-27

    Fish were collected for radionuclide analysis over a 5-month period in 1984 from creeks downstream of the Rancho Seco Nuclear Generating Plant, which has been discharging quantities of some fission and activation products to the waterway since 1981. Among the fish, the bluegill was selected for intensive study because it is very territorial and the radionuclide concentrations detected should be representative of the levels in the local environment at the downstream locations sampled. Among the gamma-emitting radionuclides routinely released, only /sup 134/Cs and /sup 137/Cs were detected in the edible flesh of fish. Concentrations in the flesh of fish decreased with distance from the plant. The relationship between concentration and distance was determined to be exponential. Exponential equations were generated to estimate concentrations in fish at downstream locations where no site-specific information was available. Mean concentrations of /sup 137/Cs in bluegill collected during April, May, July and August from specific downstream stations were not significantly different in spite of the release of 131 mCi to the creeks between April and August. The concentrations in fish are not responding to changes in water concentrations brought about by plant discharges. Diet appears to be a more significant factor than size or weight or water concentration in regulating body burdens of /sup 137/Cs in these fish.

  19. Toxicity, bioaccumulation and tissue partitioning of dieldrin by the shrimp, Macrobrachium faustinum de Sassure, in fresh and brackish waters of Jamaica.

    PubMed

    Robinson, D E; Henry, C; Mansingh, A

    2002-11-01

    The 2-week no observed effect (NOEC) and lowest observed effect (LOEC) concentrations of dieldrin were determined for Macrobrachium faustinum de Sassure in fresh and brackish waters. LOEC1,10,50,95 values in fresh water were 0.001, 0.003, 0.011 and 0.058 microg l(-1), respectively, and in brackish water, 0.00006, 0.00027, 0.00165, and 0.0172 microg l(-1), respectively. The 96-hr LC10, LC50 and LC95 values were 0.029, 0.123 and 0.771 microg l(-1), respectively. It is proposed that NOEC and LOEC be redefined to take into account the percentage of individuals affected, the severity of symptoms and the recovery of poisoned individuals. Two new terms are proposed--Median Observable Effect Concentration (MOEC) for pronounced toxic symptoms in most individuals but mortality in <50%, and Pronounced Observed Effect Concentration (POEC), which inflicts mortality in >50% individuals. Bioaccumulation of dieldrin by M. faustinum from surrounding fresh and brackish waters were rapid and fairly uniform for the first 48 h when the bioconcentration equilibrium (14.4 +/- 0.42 ng g(-1) at 0.001 microg l(-1) and 42.5 +/- 1.72 ng g(-1) at 0.01 phi g l(-1)) was achieved. Relative partitioning of residues (ng g(-1) wet wt.), after 24h exposure to 0.001 microg l(-1) of dieldrin in fresh water, in the different tissues was hepatopancreas > gonads > gills > large claws > muscle and exoskeleton. Shrimp which had accumulated 10.5 +/- 0.52 ng g(-1) dieldrin in fresh and brackish water, eliminated only about 52% of the residues after eight days in uncontaminated water.

  20. Spirulina platensis growth in open raceway ponds using fresh water supplemented with carbon, nitrogen and metal ions.

    PubMed

    Costa, Jorge Alberto Vieira; Colla, Luciane Maria; Duarte Filho, Paulo

    2003-01-01

    To investigate the feasibility of using fresh water from Mangueira Lagoon (Rio Grande do Sul, Brazil) for biomass production in open raceway ponds (0.7 m long, 0.18 m wide, 0.075 m deep) we studied the influence of nutrient addition (carbon as sodium bicarbonate, nitrogen as urea, phosphate, sulfate, ferric iron, magnesium and potassium) on the growth rate of the cyanobacteria Spirulina platensis using a 22 factorial design. In unsupplemented lagoon water production of S platensis was 0.78 +/- 0.01 g/l (dry weight basis) while the addition of 2.88 g/l of sodium bicarbonate (without added urea, phosphate, sulfate or metal ions) resulted in 0.82 +/- 0.01 g/l after 400 hours of culture. The further addition of phosphate and metal ions resulted in growth for up to 750 h and a final S. platensis biomass of 1.23 +/- 0.04 to 1.34 +/- 0.03 g/l. PMID:12622231

  1. An integrated approach for the verification of fresh mixed oxide fuel (MOX) assemblies at light water reactor MOX recycle reactors

    SciTech Connect

    Menlove, Howard O; Lee, Sang - Yoon

    2009-01-01

    This paper presents an integrated approach for the verification of mixed oxide (MOX) fuel assemblies prior to their being loaded into the reactor. There is a coupling of the verification approach that starts at the fuel fabrication plant and stops with the transfer of the assemblies into the thermal reactor. The key measurement points are at the output of the fuel fabrication plant, the receipt at the reactor site, and the storage in the water pool as fresh fuel. The IAEA currently has the capability to measure the MOX fuel assemblies at the output of the fuel fabrication plants using a passive neutron coincidence counting systems of the passive neutron collar (PNCL) type. Also. at the MOX reactor pool, the underwater coincidence counter (UWCC) has been developed to measure the MOX assemblies in the water. The UWCC measurement requires that the fuel assembly be lifted about two meters up in the storage rack to avoid interference from the fuel that is stored in the rack. This paper presents a new method to verify the MOX fuel assemblies that are in the storage rack without the necessity of moving the fuel. The detector system is called the Underwater MOX Verification System (UMVS). The integration and relationship of the three measurements systems is described.

  2. Time resolved X-ray Dark-Field Tomography Revealing Water Transport in a Fresh Cement Sample

    PubMed Central

    Prade, Friedrich; Fischer, Kai; Heinz, Detlef; Meyer, Pascal; Mohr, Jürgen; Pfeiffer, Franz

    2016-01-01

    Grating-based X-ray dark-field tomography is a promising technique for biomedical and materials research. Even if the resolution of conventional X-ray tomography does not suffice to resolve relevant structures, the dark-field signal provides valuable information about the sub-pixel microstructural properties of the sample. Here, we report on the potential of X-ray dark-field imaging to be used for time-resolved three-dimensional studies. By repeating consecutive tomography scans on a fresh cement sample, we were able to study the hardening dynamics of the cement paste in three dimensions over time. The hardening of the cement was accompanied by a strong decrease in the dark-field signal pointing to microstructural changes within the cement paste. Furthermore our results hint at the transport of water from certain limestone grains, which were embedded in the sample, to the cement paste during the process of hardening. This is indicated by an increasing scattering signal which was observed for two of the six tested limestone grains. Electron microscopy images revealed a distinct porous structure only for those two grains which supports the following interpretation of our results. When the water filled pores of the limestone grains empty during the experiment the scattering signal of the grains increases. PMID:27357449

  3. Time resolved X-ray Dark-Field Tomography Revealing Water Transport in a Fresh Cement Sample.

    PubMed

    Prade, Friedrich; Fischer, Kai; Heinz, Detlef; Meyer, Pascal; Mohr, Jürgen; Pfeiffer, Franz

    2016-01-01

    Grating-based X-ray dark-field tomography is a promising technique for biomedical and materials research. Even if the resolution of conventional X-ray tomography does not suffice to resolve relevant structures, the dark-field signal provides valuable information about the sub-pixel microstructural properties of the sample. Here, we report on the potential of X-ray dark-field imaging to be used for time-resolved three-dimensional studies. By repeating consecutive tomography scans on a fresh cement sample, we were able to study the hardening dynamics of the cement paste in three dimensions over time. The hardening of the cement was accompanied by a strong decrease in the dark-field signal pointing to microstructural changes within the cement paste. Furthermore our results hint at the transport of water from certain limestone grains, which were embedded in the sample, to the cement paste during the process of hardening. This is indicated by an increasing scattering signal which was observed for two of the six tested limestone grains. Electron microscopy images revealed a distinct porous structure only for those two grains which supports the following interpretation of our results. When the water filled pores of the limestone grains empty during the experiment the scattering signal of the grains increases. PMID:27357449

  4. Time resolved X-ray Dark-Field Tomography Revealing Water Transport in a Fresh Cement Sample

    NASA Astrophysics Data System (ADS)

    Prade, Friedrich; Fischer, Kai; Heinz, Detlef; Meyer, Pascal; Mohr, Jürgen; Pfeiffer, Franz

    2016-06-01

    Grating-based X-ray dark-field tomography is a promising technique for biomedical and materials research. Even if the resolution of conventional X-ray tomography does not suffice to resolve relevant structures, the dark-field signal provides valuable information about the sub-pixel microstructural properties of the sample. Here, we report on the potential of X-ray dark-field imaging to be used for time-resolved three-dimensional studies. By repeating consecutive tomography scans on a fresh cement sample, we were able to study the hardening dynamics of the cement paste in three dimensions over time. The hardening of the cement was accompanied by a strong decrease in the dark-field signal pointing to microstructural changes within the cement paste. Furthermore our results hint at the transport of water from certain limestone grains, which were embedded in the sample, to the cement paste during the process of hardening. This is indicated by an increasing scattering signal which was observed for two of the six tested limestone grains. Electron microscopy images revealed a distinct porous structure only for those two grains which supports the following interpretation of our results. When the water filled pores of the limestone grains empty during the experiment the scattering signal of the grains increases.

  5. Precipitation and Runoff Simulations of the Carson Range and Pine Nut Mountains, and Updated Estimates of Ground-Water Inflow and the Ground-Water Budgets for Basin-Fill Aquifers of Carson Valley, Douglas County, Nevada, and Alpine County, California

    USGS Publications Warehouse

    Jeton, Anne E.; Maurer, Douglas K.

    2007-01-01

    Recent estimates of ground-water inflow to the basin-fill aquifers of Carson Valley, Nevada, and California, from the adjacent Carson Range and Pine Nut Mountains ranged from 22,000 to 40,000 acre-feet per year using water-yield and chloride-balance methods. In this study, watershed models were developed for watersheds with perennial streams and for watersheds with ephemeral streams in the Carson Range and Pine Nut Mountains to provide an independent estimate of ground-water inflow. This report documents the development and calibration of the watershed models, presents model results, compares the results with recent estimates of ground-water inflow to the basin-fill aquifers of Carson Valley, and presents updated estimates of the ground-water budget for basin-fill aquifers of Carson Valley. The model used for the study was the Precipitation-Runoff Modeling System, a physically based, distributed-parameter model designed to simulate precipitation and snowmelt runoff as well as snowpack accumulation and snowmelt processes. Geographic Information System software was used to manage spatial data, characterize model drainages, and to develop Hydrologic Response Units. Models were developed for * Two watersheds with gaged perennial streams in the Carson Range and two watersheds with gaged perennial streams in the Pine Nut Mountains using measured daily mean runoff, * Ten watersheds with ungaged perennial streams using estimated daily mean runoff, * Ten watershed with ungaged ephemeral streams in the Carson Range, and * A large area of ephemeral runoff near the Pine Nut Mountains. Models developed for the gaged watersheds were used as index models to guide the calibration of models for ungaged watersheds. Model calibration was constrained by daily mean runoff for 4 gaged watersheds and for 10 ungaged watersheds in the Carson Range estimated in a previous study. The models were further constrained by annual precipitation volumes estimated in a previous study to provide

  6. Comparative food-chain behavior and distribution of actinide elements in and around a contaminated fresh-water pond

    SciTech Connect

    Garten, C.T. Jr.; Trabalka, J.R.; Bogle, M.A.

    1981-01-01

    The bioaccumulation of /sup 233/ /sup 234/U, /sup 238/U, /sup 238/Pu, /sup 239/ /sup 240/Pu, /sup 241/Am, and /sup 244/Cm in both native and introduced biota was studied at Pond 3513, a former low-level radioactive waste settling basin at Oak Ridge National Laboratory. This system, which was decommissioned in 1976 after more than 30 years use, contains approximately 5 Ci of /sup 239/ /sup 240/Pu; inventories of other actinide isotopes are considerably less. Significantly higher concentrations of actinides in fish that were allowed access to sediments indicated that sedimentary particulates may be the primary source of transuranics to biota in shallow fresh-water ecosystems. Our study determined habitat, in particular the degree of association of an organism with the sediment-water interface, to be the primary factor in controlling transuranic concentrations in aquatic biota. In most of the biological samples analyzed, excluding samples suspected of being contaminated by sediment, /sup 241/Am//sup 239/Pu, /sup 244/Cm//sup 239/Pu, and /sup 238/U//sup 239/Pu ratios were greater than the respective ratio in sediment while /sup 233/ /sup 234/U//sup 238/U, and /sup 239/ /sup 240/Pu//sup 238/Pu ratios were not different from the respective ratios in sediment. The relative uptake of actinides from contaminated sediment by aquatic and terrestrial biota at this site was U > Cm greater than or equal to Am > Pu. The relative extractability of actinides from shoreline sediment was U > Cm approx. = Am > Pu; we also observed the same relative ranking for sediment-water exchange in situ. Concentrations of transuranics in water, terrestrial vegetation, and vertebrate carcasses were less than 10% of the recommended public exposure maximum permissible concentration (MPC) of the ICRP.

  7. Water use and quality of fresh surface-water resources in the Barataria-Terrebonne Basins, Louisiana

    USGS Publications Warehouse

    Johnson-Thibaut, Penny M.; Demcheck, Dennis K.; Swarzenski, Christopher M.; Ensminger, Paul A.

    1998-01-01

    Approximately 170 Mgal/d (million gallons per day) of ground- and surface-water was withdrawn from the Barataria-Terrebonne Basins in 1995. Of this amount, surface water accounted for 64 percent ( 110 MgaVd) of the total withdrawal rates in the basins. The largest surface-water withdrawal rates were from Bayou Lafourche ( 40 Mgal/d), Bayou Boeuf ( 14 MgaVd), and the Gulf Intracoastal Waterway (4.2 Mgal/d). The largest ground-water withdrawal rates were from the Mississippi River alluvial aquifer (29 Mgal/d), the Gonzales-New Orleans aquifer (9.5 Mgal/d), and the Norco aquifer (3.6 MgaVd). The amounts of water withdrawn in the basins in 1995 differed by category of use. Public water suppliers within the basins withdrew 41 Mgal/d of water. The five largest public water suppliers in the basins withdrew 30 Mgal/d of surface water: Terrebonne Waterworks District 1 withdrew the largest amount, almost 15 MgaVd. Industrial facilities withdrew 88 Mgal/d, fossil-fuel plants withdrew 4.7 MgaVd, and commercial facilities withdrew 0.67 MgaVd. Aggregate water-withdrawal rates, compiled by parish for aquaculture (37 Mgal/d), livestock (0.56 Mgal/d), rural domestic (0.44 MgaVd), and irrigation uses (0.54 MgaVd), totaled about 38 MgaVd in the basins. Ninety-five percent of aquaculture withdrawal rates, primarily for crawfish and alligator farming, were from surface-water sources. >br> Total water-withdrawal rates increased 221 percent from 1960–95. Surface-water withdrawal rates have increased by 310 percent, and ground-water withdrawal rates have increased by 133 percent. The projection for the total water-withdrawal rates in 2020 is 220 MgaVd, an increase of 30 percent from 1995. Surface-water withdrawal rates would account for 59 percent of the total, or 130 Mgal/d. Surface-water withdrawal rates are projected to increase by 20 percent from 1995 to 2020. Analysis of water-quality data from the Mississippi River indicates that the main threats to surface water resources are

  8. Sulfated modification and immunomodulatory activity of water-soluble polysaccharides derived from fresh Chinese persimmon fruit.

    PubMed

    Zhang, Yali; Lu, Xiaoyun; Zhang, Yuning; Qin, Liguo; Zhang, Jianbao

    2010-01-01

    In this study, three kinds of chemically sulfated polysaccharides (PFP-S) were derived from a water-soluble polysaccharide of persimmon fruit with chlorosulfonic acid-pyridine method. Relationship between the degree of substitution and immunomodulatory activity of PFP-S was examined with the splenocytes experiment. The results showed that the splenocytes-activating activity was significantly enhanced by PFP-S in all the groups compared with control group (P<0.01). PFP-SII exhibited the most potent splenocytes-activating activity by increased cytokine production and NO release. It also suggested that the sulfate groups and molecular weight of polysaccharides are key factors to regulate the immunomodulatory activities.

  9. Timing of magnesium supplementation administered through drinking water to improve fresh and stored pork quality.

    PubMed

    Frederick, B R; van Heugten, E; See, M T

    2004-05-01

    Thirty-two pigs were used to determine the timing effect of magnesium (Mg) supplementation given through drinking water on pork quality. Pigs (16 barrows and 16 gilts) were individually penned, provided 2.7 kg of feed (0.12% Mg) daily (as-fed basis), and allowed free access to water via a nipple waterer for the duration of the study. After 5 d of adjustment, pigs (120 +/- 0.8 kg BW) were allotted randomly by weight and sex to 900 mg/L of supplemental Mg from magnesium sulfate heptahydrate in drinking water for -6, -4, -2, or 0 d relative to slaughter. The LM and semimembranosus (SM) muscles were removed 24 h postmortem. Retail display storage was simulated for 8 d, and the LM was vacuum-packaged for 25 or 50 d at 4 degrees C. Magnesium did not affect the pH of the LM at either 45 min (P = 0.15) or 24 h postmortem (P = 0.23). However, the pH of the SM at 24 h postmortem tended to be greater (P = 0.08) for pigs consuming Mg for 2 d than for those not supplemented. Fluid loss after 8 d of storage was less (P < 0.05) in the LM of pigs supplemented with Mg for 6 d than in those without supplementation. Furthermore, fluid loss from the SM of pigs provided supplemental Mg for 2 d, but not for 4 or 6 d, was lower (P < 0.05) on each day of retail display than the SM of unsupplemented pigs. Minolta L*, a*, and b* color measurements of the LM during display storage were not (P > 0.10) affected by Mg supplementation. However, Mg supplementation for 2 or 4 d decreased paleness (lower L* value) after 25 d (P < 0.05), but not 50 d (P > 0.10) of vacuum-packaged storage. Magnesium addition for 2 d decreased the extent of oxidation (thiobarbituric acid-reactive substances) of the LM after 4 d of display storage compared with 0 d of Mg (P < 0.05). Oxidation of the SM during 8 d of display storage increased linearly (P < 0.05) as duration of supplementation increased from 2 to 6 d but did not differ (P = 0.22) from 0 d of Mg supplementation. Although the response to Mg supplementation

  10. Pantoea sp. isolated from tropical fresh water exhibiting N-acyl homoserine lactone production.

    PubMed

    Tan, Wen-Si; Muhamad Yunos, Nina Yusrina; Tan, Pui-Wan; Mohamad, Nur Izzati; Adrian, Tan-Guan-Sheng; Yin, Wai-Fong; Chan, Kok-Gan

    2014-01-01

    N-Acyl homoserine lactone (AHL) serves as signaling molecule for quorum sensing (QS) in Gram-negative bacteria to regulate various physiological activities including pathogenicity. With the aim of isolating freshwater-borne bacteria that can cause outbreak of disease in plants and portrayed QS properties, environmental water sampling was conducted. Here we report the preliminary screening of AHL production using Chromobacterium violaceum CV026 and Escherichia coli [pSB401] as AHL biosensors. The 16S rDNA gene sequence of isolate M009 showed the highest sequence similarity to Pantoea stewartii S9-116, which is a plant pathogen. The isolated Pantoea sp. was confirmed to produce N-3-oxohexanoyl-L-HSL (3-oxo-C6-HSL) through analysis of high resolution mass tandem mass spectrometry.

  11. Pantoea sp. Isolated from Tropical Fresh Water Exhibiting N-Acyl Homoserine Lactone Production

    PubMed Central

    Tan, Wen-Si; Tan, Pui-Wan; Adrian, Tan-Guan-Sheng; Yin, Wai-Fong; Chan, Kok-Gan

    2014-01-01

    N-Acyl homoserine lactone (AHL) serves as signaling molecule for quorum sensing (QS) in Gram-negative bacteria to regulate various physiological activities including pathogenicity. With the aim of isolating freshwater-borne bacteria that can cause outbreak of disease in plants and portrayed QS properties, environmental water sampling was conducted. Here we report the preliminary screening of AHL production using Chromobacterium violaceum CV026 and Escherichia coli [pSB401] as AHL biosensors. The 16S rDNA gene sequence of isolate M009 showed the highest sequence similarity to Pantoea stewartii S9-116, which is a plant pathogen. The isolated Pantoea sp. was confirmed to produce N-3-oxohexanoyl-L-HSL (3-oxo-C6-HSL) through analysis of high resolution mass tandem mass spectrometry. PMID:25197715

  12. Timing of magnesium supplementation administered through drinking water to improve fresh and stored pork quality.

    PubMed

    Frederick, B R; van Heugten, E; See, M T

    2004-05-01

    Thirty-two pigs were used to determine the timing effect of magnesium (Mg) supplementation given through drinking water on pork quality. Pigs (16 barrows and 16 gilts) were individually penned, provided 2.7 kg of feed (0.12% Mg) daily (as-fed basis), and allowed free access to water via a nipple waterer for the duration of the study. After 5 d of adjustment, pigs (120 +/- 0.8 kg BW) were allotted randomly by weight and sex to 900 mg/L of supplemental Mg from magnesium sulfate heptahydrate in drinking water for -6, -4, -2, or 0 d relative to slaughter. The LM and semimembranosus (SM) muscles were removed 24 h postmortem. Retail display storage was simulated for 8 d, and the LM was vacuum-packaged for 25 or 50 d at 4 degrees C. Magnesium did not affect the pH of the LM at either 45 min (P = 0.15) or 24 h postmortem (P = 0.23). However, the pH of the SM at 24 h postmortem tended to be greater (P = 0.08) for pigs consuming Mg for 2 d than for those not supplemented. Fluid loss after 8 d of storage was less (P < 0.05) in the LM of pigs supplemented with Mg for 6 d than in those without supplementation. Furthermore, fluid loss from the SM of pigs provided supplemental Mg for 2 d, but not for 4 or 6 d, was lower (P < 0.05) on each day of retail display than the SM of unsupplemented pigs. Minolta L*, a*, and b* color measurements of the LM during display storage were not (P > 0.10) affected by Mg supplementation. However, Mg supplementation for 2 or 4 d decreased paleness (lower L* value) after 25 d (P < 0.05), but not 50 d (P > 0.10) of vacuum-packaged storage. Magnesium addition for 2 d decreased the extent of oxidation (thiobarbituric acid-reactive substances) of the LM after 4 d of display storage compared with 0 d of Mg (P < 0.05). Oxidation of the SM during 8 d of display storage increased linearly (P < 0.05) as duration of supplementation increased from 2 to 6 d but did not differ (P = 0.22) from 0 d of Mg supplementation. Although the response to Mg supplementation

  13. Antibiotics, Antibiotic Resistance Genes, and Bacterial Community Composition in Fresh Water Aquaculture Environment in China.

    PubMed

    Xiong, Wenguang; Sun, Yongxue; Zhang, Tong; Ding, Xueyao; Li, Yafei; Wang, Mianzhi; Zeng, Zhenling

    2015-08-01

    Environmental antibiotic resistance has drawn increasing attention due to its great threat to human health. In this study, we investigated concentrations of antibiotics (tetracyclines, sulfonamides and (fluoro)quinolones) and abundances of antibiotic resistance genes (ARGs), including tetracycline resistance genes, sulfonamide resistance genes, and plasmid-mediated quinolone resistance genes, and analyzed bacterial community composition in aquaculture environment in Guangdong, China. The concentrations of sulfametoxydiazine, sulfamethazine, sulfamethoxazole, oxytetracycline, chlorotetracycline, doxycycline, ciprofloxacin, norfloxacin, and enrofloxacin were as high as 446 μg kg(-1) and 98.6 ng L(-1) in sediment and water samples, respectively. The relative abundances (ARG copies/16S ribosomal RNA (rRNA) gene copies) of ARGs (sul1, sul2, sul3, tetM, tetO, tetW, tetS, tetQ, tetX, tetB/P, qepA, oqxA, oqxB, aac(6')-Ib, and qnrS) were as high as 2.8 × 10(-2). The dominant phyla were Proteobacteria, Bacteroidetes, and Firmicutes in sediment samples and Proteobacteria, Actinobacteria and Bacteroidetes in water samples. The genera associated with pathogens were also observed, such as Acinetobacter, Arcobacter, and Clostridium. This study comprehensively investigated antibiotics, ARGs, and bacterial community composition in aquaculture environment in China. The results indicated that fish ponds are reservoirs of ARGs and the presence of potential resistant and pathogen-associated taxonomic groups in fish ponds might imply the potential risk to human health.

  14. Physicochemical quality and chemical safety of chlorine as a reconditioning agent and wash water disinfectant for fresh-cut lettuce washing.

    PubMed

    Van Haute, Sam; Sampers, Imca; Holvoet, Kevin; Uyttendaele, Mieke

    2013-05-01

    Chlorine was assessed as a reconditioning agent and wash water disinfectant in the fresh-cut produce industry. Artificial fresh-cut lettuce wash water, made from butterhead lettuce, was used for the experiments. In the reconditioning experiments, chlorine was added to artificial wash water inoculated with Escherichia coli O157 (6 log CFU/ml). Regression models were constructed based on the inactivation data and validated in actual wash water from leafy vegetable processing companies. The model that incorporated chlorine dose and chemical oxygen demand (COD) of the wash water accurately predicted inactivation. Listeria monocytogenes was more resistant to chlorine reconditioning in artificial wash water than Salmonella spp. and Escherichia coli O157. During the washing process with inoculated lettuce (4 log CFU/g), in the absence of chlorine, there was a rapid microbial buildup in the water that accumulated to 5.4 ± 0.4 log CFU/100 ml after 1 h. When maintaining a residual concentration of 1 mg/liter free chlorine, wash water contamination was maintained below 2.7, 2.5, and 2.5 log CFU/100 ml for tap water and artificial process water with COD values of 500 and 1,000 mg O2/liter, respectively. A model was developed to predict water contamination during the dynamic washing process. Only minor amounts of total trihalomethanes were formed in the water during reconditioning. Total trihalomethanes accumulated to larger amounts in the water during the wash water disinfection experiments and reached 124.5 ± 13.4 μg/liter after 1 h of execution of the washing process in water with a COD of 1,000 mg O2/liter. However, no total trihalomethanes were found on the fresh-cut lettuce after rinsing.

  15. Physicochemical Quality and Chemical Safety of Chlorine as a Reconditioning Agent and Wash Water Disinfectant for Fresh-Cut Lettuce Washing

    PubMed Central

    Van Haute, Sam; Holvoet, Kevin; Uyttendaele, Mieke

    2013-01-01

    Chlorine was assessed as a reconditioning agent and wash water disinfectant in the fresh-cut produce industry. Artificial fresh-cut lettuce wash water, made from butterhead lettuce, was used for the experiments. In the reconditioning experiments, chlorine was added to artificial wash water inoculated with Escherichia coli O157 (6 log CFU/ml). Regression models were constructed based on the inactivation data and validated in actual wash water from leafy vegetable processing companies. The model that incorporated chlorine dose and chemical oxygen demand (COD) of the wash water accurately predicted inactivation. Listeria monocytogenes was more resistant to chlorine reconditioning in artificial wash water than Salmonella spp. and Escherichia coli O157. During the washing process with inoculated lettuce (4 log CFU/g), in the absence of chlorine, there was a rapid microbial buildup in the water that accumulated to 5.4 ± 0.4 log CFU/100 ml after 1 h. When maintaining a residual concentration of 1 mg/liter free chlorine, wash water contamination was maintained below 2.7, 2.5, and 2.5 log CFU/100 ml for tap water and artificial process water with COD values of 500 and 1,000 mg O2/liter, respectively. A model was developed to predict water contamination during the dynamic washing process. Only minor amounts of total trihalomethanes were formed in the water during reconditioning. Total trihalomethanes accumulated to larger amounts in the water during the wash water disinfection experiments and reached 124.5 ± 13.4 μg/liter after 1 h of execution of the washing process in water with a COD of 1,000 mg O2/liter. However, no total trihalomethanes were found on the fresh-cut lettuce after rinsing. PMID:23396332

  16. MONITORING DIBUTYLTIN AND TRIPHENYLTIN IN FRESH WATERS AND FISH IN THE UNITED STATES USING MICRO-LIQUID CHROMATOGRAPHY-ELECTROSPRAY/ION TRAP MASS SPECTROMETRY

    EPA Science Inventory

    There is a growing body of evidence that toxic organotins are making their way into humans and other mammals (terrestrial and marine). One possible route of environmental exposure in the U.S. to organotins (specifically dibutyltin and triphenyltin) is via fresh surface waters, an...

  17. Cytoplasmic Membrane Changes during Adaptation of the Fresh Water Cyanobacterium Synechococcus 6311 to Salinity 1

    PubMed Central

    Lefort-Tran, Marcelle; Pouphile, Monique; Spath, Susan; Packer, Lester

    1988-01-01

    In this investigation, changes were characterized in cell structure and cytoplasmic membrane organization that occur when the freshwater cyanobacterium Synechococcus 6311 is transferred from `low salt' (0.03 molar NaCl) to `high salt' (0.5 molar NaCl) media (i.e. sea water concentration). Cells were examined at several time points after the imposition of the salt stress and compared to control cells, in thin sections and freeze fracture electron microscopy, and by flow cytometry. One minute after exposure to high salt, i.e. `salt shock,' virtually all intracellular granules disappeared, the density of the cytoplasm decreased, and the appearance of DNA material was changed. Glycogen and other granules, however, reappeared by 4 hours after salt exposure. The organization of the cytoplasmic membrane undergoes major reorganization following salt shock. Freeze-fracture electron microscopy showed that small intramembrane particles (diameters 7.5 and 8.5 nanometers) are reduced in number by two- to fivefold, whereas large particles, (diameters 14.5 and 17.5 nanometers) increase two- to fourfold in frequency, compared to control cells grown in low salt medium. The changes in particle size distribution suggest synthesis of new membrane proteins, in agreement with the known increases in respiration, cytochrome oxidase, and sodium proton exchange activity of the cytoplasmic membrane. Images Fig. 2 Fig. 1 Fig. 5 PMID:11537874

  18. Cataract development in Atlantic salmon (Salmo salar L) in fresh water.

    PubMed

    Bjerkås, E; Waagbø, R; Sveier, H; Breck, O; Bjerkås, I; Bjørnestad, E; Maage, A

    1996-01-01

    Irreversible bilateral cataracts were diagnosed by slit-lamp biomicroscopy in 178 of 200 farm-raised Atlantic salmon (Salmo salar L) fed a standard diet over a five-month period. Initial changes were anterior polar opacities, progressing to involve both the anterior and posterior cortex before changes in the lens nucleus were seen. The lens changes were recorded and given scores according to the severity of the cataracts. At each of 3 samplings, after 2, 4 and 5 months, 200 fish were measured, weighed and examined by slit-lamp biomicroscopy. At all 3 samplings, there was a significant correlation between body length and both cataract incidence and cataract severity. There was also a significant correlation between body weight and cataract incidence and severity for the 2 last samplings. There was a significant correlation between K-factor as a measure of the shape of the fish, and both cataract incidence and severity, at all 3 samplings. Evaluation of specific growth rate in the periods between the examinations showed that the rapidly-growing fish were most susceptible to cataract formation. After cataract developed, however, the growth rate slowed. Follow-up examination of severely affected fish 3 months after transfer to sea water showed a normal cortical zone in the periphery of the lens in 24 out of 28 fish.

  19. The times are changing: temporal shifts in patterns of fish invasions in central European fresh waters.

    PubMed

    Rabitsch, W; Milasowszky, N; Nehring, S; Wiesner, C; Wolter, C; Essl, F

    2013-01-01

    This study examines the invasion history of alien fish species based on exhaustive national data sets on fish invasions of two contiguous central European countries (Germany and Austria). Fifteen alien fish species are currently established in both countries, constituting 14 and 17% of the total freshwater fish fauna of Germany and Austria, respectively. In both countries, six alien species are present, but not established. The status of five alien species in Germany and three species in Austria remains unknown. Accumulation rates of alien fish species have increased in recent decades with >50% of them reported after 1971. North America and Asia were the primary sources of alien fish species in Germany and Austria up to the 1980s, whereas European species of Ponto-Caspian origin dominate now. Fisheries (including aquaculture) and the animal trade were responsible for most earlier introductions, whereas waterways were the main pathway for recent invaders. The extent of the spatial distribution of alien species was positively correlated with residence time, i.e. the time elapsed since the first national record. Different thermal preferences of early invaders (mostly coldwater species) and new invaders (typically warmwater adapted) may benefit the latter in the face of climate change. It is concluded that new challenges for alien fish management arise and that ecosystem-based approaches as endorsed by the E.U. Water Framework Directive (maintaining or restoring good ecological status of rivers and streams) should become the centrepiece of river management in Europe.

  20. Cytoplasmic membrane changes during adaptation of the fresh water cyanobacterium Synechococcus 6311 to salinity

    NASA Technical Reports Server (NTRS)

    Lefort-Tran, M.; Pouphile, M.; Spath, S.; Packer, L.

    1988-01-01

    In this investigation, changes were characterized in cell structure and cytoplasmic membrane organization that occur when the freshwater cyanobacterium Synechococcus 6311 is transferred from 'low salt' (0.03 molar NaCl) to 'high salt' (0.5 molar NaCl) media (i.e. sea water concentration). Cells were examined at several time points after the imposition of the salt stress and compared to control cells, in thin sections and freeze fracture electron microscopy, and by flow cytometry. One minute after exposure to high salt, i.e. 'salt shock', virtually all intracellular granules disappeared, the density of the cytoplasm decreased, and the appearance of DNA material was changed. Glycogen and other granules, however, reappeared by 4 hours after salt exposure. The organization of the cytoplasmic membrane undergoes major reorganization following salt shock. Freeze-fracture electron microscopy showed that small intramembrane particles (diameter 7.5 and 8.5 nanometers) are reduced in number by two- to fivefold, whereas large particles, (diameters 14.5 and 17.5 nanometers) increase two- to fourfold in frequency, compared to control cells grown in low salt medium. The changes in particle size distribution suggest synthesis of new membrane proteins, in agreement with the known increases in respiration, cytochrome oxidase, and sodium proton exchange activity of the cytoplasmic membrane.

  1. Phenotypic and Genetic Diversity of Aeromonas Species Isolated from Fresh Water Lakes in Malaysia

    PubMed Central

    Khor, Wei Ching; Puah, Suat Moi; Tan, Jin Ai Mary Anne; Puthucheary, SD; Chua, Kek Heng

    2015-01-01

    Gram-negative bacilli of the genus Aeromonas are primarily inhabitants of the aquatic environment. Humans acquire this organism from a wide range of food and water sources as well as during aquatic recreational activities. In the present study, the diversity and distribution of Aeromonas species from freshwater lakes in Malaysia was investigated using glycerophospholipid-cholesterol acyltransferase (GCAT) and RNA polymerase sigma-factor (rpoD) genes for speciation. A total of 122 possible Aeromonas strains were isolated and confirmed to genus level using the API20E system. The clonality of the isolates was investigated using ERIC-PCR and 20 duplicate isolates were excluded from the study. The specific GCAT-PCR identified all isolates as belonging to the genus Aeromonas, in agreement with the biochemical identification. A phylogenetic tree was constructed using the rpoD gene sequence and all 102 isolates were identified as: A. veronii 43%, A. jandaei 37%, A. hydrophila 6%, A. caviae 4%, A. salmonicida 2%, A. media 2%, A. allosaccharophila 1%, A. dhakensis 1% and Aeromonas spp. 4%. Twelve virulence genes were present in the following proportions—exu 96%, ser 93%, aer 87%, fla 83%, enolase 70%, ela 62%, act 54%, aexT 33%, lip 16%, dam 16%, alt 8% and ast 4%, and at least 2 of these genes were present in all 102 strains. The ascV, aexU and hlyA genes were not detected among the isolates. A. hydrophila was the main species containing virulence genes alt and ast either present alone or in combination. It is possible that different mechanisms may be used by each genospecies to demonstrate virulence. In summary, with the use of GCAT and rpoD genes, unambiguous identification of Aeromonas species is possible and provides valuable data on the phylogenetic diversity of the organism. PMID:26710336

  2. Phenotypic and Genetic Diversity of Aeromonas Species Isolated from Fresh Water Lakes in Malaysia.

    PubMed

    Khor, Wei Ching; Puah, Suat Moi; Tan, Jin Ai Mary Anne; Puthucheary, S D; Chua, Kek Heng

    2015-01-01

    Gram-negative bacilli of the genus Aeromonas are primarily inhabitants of the aquatic environment. Humans acquire this organism from a wide range of food and water sources as well as during aquatic recreational activities. In the present study, the diversity and distribution of Aeromonas species from freshwater lakes in Malaysia was investigated using glycerophospholipid-cholesterol acyltransferase (GCAT) and RNA polymerase sigma-factor (rpoD) genes for speciation. A total of 122 possible Aeromonas strains were isolated and confirmed to genus level using the API20E system. The clonality of the isolates was investigated using ERIC-PCR and 20 duplicate isolates were excluded from the study. The specific GCAT-PCR identified all isolates as belonging to the genus Aeromonas, in agreement with the biochemical identification. A phylogenetic tree was constructed using the rpoD gene sequence and all 102 isolates were identified as: A. veronii 43%, A. jandaei 37%, A. hydrophila 6%, A. caviae 4%, A. salmonicida 2%, A. media 2%, A. allosaccharophila 1%, A. dhakensis 1% and Aeromonas spp. 4%. Twelve virulence genes were present in the following proportions--exu 96%, ser 93%, aer 87%, fla 83%, enolase 70%, ela 62%, act 54%, aexT 33%, lip 16%, dam 16%, alt 8% and ast 4%, and at least 2 of these genes were present in all 102 strains. The ascV, aexU and hlyA genes were not detected among the isolates. A. hydrophila was the main species containing virulence genes alt and ast either present alone or in combination. It is possible that different mechanisms may be used by each genospecies to demonstrate virulence. In summary, with the use of GCAT and rpoD genes, unambiguous identification of Aeromonas species is possible and provides valuable data on the phylogenetic diversity of the organism.

  3. Effects of nutritional modifications on the water-holding capacity of fresh pork: a review.

    PubMed

    Apple, J K

    2007-11-01

    Although genetics and preslaughter handling and management have the greatest impact on pork quality - especially water-holding capacity (WHC) - modifications to swine diets may offset the negative effects of genotype and/or pig handling on pork quality or improve quality attributes of pork from pigs with the genetic potential for good quality. There is little evidence that pork WHC is altered by the lysine or protein level (and source), cereal grain, or fat source used in growing-finishing diets. Yet, recent research indicates that feeding low-starch, high-fibre, high-fat, glycogen-reducing diets effectively improves the WHC of pork. Moreover, meta-analysis of the available information indicated that including 100, 200, or 400+ mg of alpha-tochopherol per kilogram of diet reduced pork drip losses by 10.1%, 30.5%, and 25.9%, respectively, whereas supplementing swine diets with magnesium for 1-2 days, 3-4 days, or 5-7 days reduced drip losses by 23.1%, 13.7%, or 15.9%, respectively. Some swine nutritionists have advocated the removal of vitamins and trace minerals from finishing diets; however, deletion of vitamin/trace mineral premixes actually reduced the WHC of pork, whereas drip losses were reduced by elevating the dietary inclusion levels of vitamins and trace minerals 150-250% of the recommended levels. Additionally, there is no evidence that feeding pigs ractopamine hydrochloride or injections of porcine somatotropin affect pork WHC. There may not be a single 'silver bullet' that will remedy poor quality genetics or poor animal management, but improvements in pork WHC can be achieved with some modifications to swine finishing diets.

  4. The study of fresh-water lake ice using multiplexed imaging radar

    USGS Publications Warehouse

    Leonard, Bryan M.; Larson, R.W.

    1975-01-01

    The study of ice in the upper Great Lakes, both from the operational and the scientific points of view, is receiving continued attention. Quantitative and qualitative field work is being conducted to provide the needed background for accurate interpretation of remotely sensed data. The data under discussion in this paper were obtained by a side-looking multiplexed airborne radar (SLAR) supplemented with ground-truth data.Because of its ability to penetrate adverse weather, radar is an especially important instrument for monitoring ice in the upper Great Lakes. It has previously been shown that imaging radars can provide maps of ice cover in these areas. However, questions concerning both the nature of the surfaces reflecting radar energy and the interpretation of the radar imagery continually arise.Our analysis of ice in Whitefish Bay (Lake Superior) indicates that the combination of the ice/water interlace and the ice/air interface is the major contributor to the radar backscatter as seen on the imagery At these frequencies the ice has a very low relative dielectric permittivity (< 3.0) and a low loss tangent Thus, this ice is somewhat transparent to the energy used by the imaging SLAR system. The ice types studied include newly formed black ice, pancake ice, and frozen and consolidated pack and brash ice.Although ice thickness cannot be measured directly from the received signals, it is suspected that by combining the information pertaining to radar backscatter with data on the meteorological and sea-state history of the area, together with some basic ground truth, better estimates of the ice thickness may be provided. In addition, certain ice features (e.g. ridges, ice-foot formation, areas of brash ice) may be identified with reasonable confidence. There is a continued need for additional ground work to verify the validity of imaging radars for these types of interpretations.

  5. Organophosphorus flame retardants and plasticizers in marine and fresh water biota and in human milk.

    PubMed

    Sundkvist, Anneli Marklund; Olofsson, Ulrika; Haglund, Peter

    2010-04-01

    The levels and relative proportions of 11 organophosphorus flame retardants and plasticizers (OPs), some of which are reportedly toxic to aquatic organisms, were investigated in human breast milk and samples of fish and mussels from Swedish lakes and coastal areas in order to assess spatial differences in environmental exposure and spatial and temporal differences in human exposure. Some of the biota samples were collected at locations with known potential sources of OPs, but most were collected in background locations. Tris-2-chloroisopropyl phosphate (TCPP) and triphenyl phosphate (TPP) dominated in the biota with levels ranging from 170 to 770 ng g(-1) for TCPP in perch and between 21 and 180 ng g(-1) for TPP. In milk samples, TCPP (median 45 ng g(-1)) and tributyl phosphate (median 12 ng g(-1)) were the most frequently occurring OPs. Among samples of fish from background locations, the concentrations and profiles of most OPs were quite similar, indicating that their sources were diffuse. However, in fish from sample locations near known sources, there were marked differences in OP concentrations and profiles. Fish from a stream receiving surface water from Arlanda airport displayed high levels of OPs (10 200 ng g(-1)) that are commonly used in aircraft hydraulic fluids. Fish collected at points 1 or 2 km downstream of sewage treatment plants showed significantly higher levels of tris(2-butoxyethyl) phosphate (TBEP), one of the most typically abundant OP in effluents from such plants. In the milk samples obtained from women in different towns no distinct differences were detected in OP concentrations or profiles. However, the levels of TBEP tended to be higher in milk collected 10 years ago than in milk collected more recently. However, human exposure to OPs through eating fish or to breastfeeding babies seems to be of minor importance in relation to other potential sources, such as indoor dust inhalation and ingestion.

  6. Drinking water decontamination by biological denitrification using fresh bamboo as inoculum source.

    PubMed

    Bucco, Samuel; Padoin, Natan; Netto, Willibaldo Schmidell; Soares, Hugo Moreira

    2014-10-01

    Groundwater contamination is becoming a serious problem in many Brazilian regions. European countries started to deal with this issue in the 1980s, mainly caused by the extensive usage of nitrogenous fertilizers and the absence of domestic wastewater treatment. Due to its high solubility, nitrate readily passes through the soil and reaches the aquifer. Thereafter, this ion moves, following groundwater flow, and can be found several kilometers from the area where the pollution occurred. Concern about nitrate contamination is due to the link found between this contaminant and various human health diseases, such as methemoglobin and cancer. Studies carried out in France enabled the design and implementation of several biological denitrification plants throughout the country, in order to remove nitrate from its contaminated groundwater. Heterotrophic denitrification facilities shown to be adequate to treat high water flows with satisfactory nitrate removal efficiency, especially when static media supports are employed. The objective of this research was to evaluate the existence of denitrifying microorganisms in bamboo (Bambusa tuldóides) and verify the feasibility of their use to inoculate a pilot-scale fixed-bed bioreactor. The support material selected to fill the bioreactor bed was commercial polypropylene Pall rings, since such support has a high porosity associated with a wide superficial area. The bioreactor was able to produce and retain a large amount of cells. Using ethanol as carbon source, nitrate (N-NO3(-)) removal efficiency of the bioreactor stood around 80 % for a maximum nitrogen loading rate of approximately 6.5 mg N-NO3 (-) L(-1) h(-1).

  7. Contamination of fish in UK fresh water systems: risk assessment for human consumption.

    PubMed

    Rose, Martin; Fernandes, Alwyn; Mortimer, David; Baskaran, Christina

    2015-03-01

    There is growing evidence that more people in the UK are consuming fish taken from inland waterways. This may be partly due to the increased numbers of migrants from Eastern Europe where this is part of traditional culture and partly because of a desire to try new foods encouraged by celebrity chefs. Fish can bioaccumulate environmental contaminants and so could contribute a significant amount to dietary exposure to these chemicals. This study examined the changing habits of anglers and consumers and characterised a range of existing and emerging contaminants in freshwater fish species with a view to determining current levels of occurrence and possible risk from consumption. The project was conducted in two stages. The first stage included (a) a study that identified freshwater systems that are contaminated either by anthropogenic activity or as a result of the geology of the area; and (b) socioeconomic research to assess the consumption habits of the public, particularly anglers, with respect to fish and shellfish from unmanaged inland waterways. Based on the outcome from the first stage, specific rivers and other inland waterways were chosen for investigation, along with the range of contaminants to be included in the analytical programme. Predicted contamination levels and prevalence of anglers were among the factors taken into consideration. The second stage of the project involved sampling and analysis of fish taken from selected locations on the chosen waterways. A range of fish species from a variety of inland water habitats were obtained. These were analysed for the following contaminants: heavy metals, chlorinated dioxins (PCDD/Fs), polybrominated biphenyls (PBBs), polychlorinated biphenyls (PCBs), brominated dioxins (PBDD/Fs), polychlorinated naphthalenes (PCNs), polybrominated diphenylethers (PBDEs), OC pesticides, organotin compounds and organo-fluorine compounds. Legal limits for contaminants apply only to food traded commercially, but some samples

  8. Contamination of fish in UK fresh water systems: risk assessment for human consumption.

    PubMed

    Rose, Martin; Fernandes, Alwyn; Mortimer, David; Baskaran, Christina

    2015-03-01

    There is growing evidence that more people in the UK are consuming fish taken from inland waterways. This may be partly due to the increased numbers of migrants from Eastern Europe where this is part of traditional culture and partly because of a desire to try new foods encouraged by celebrity chefs. Fish can bioaccumulate environmental contaminants and so could contribute a significant amount to dietary exposure to these chemicals. This study examined the changing habits of anglers and consumers and characterised a range of existing and emerging contaminants in freshwater fish species with a view to determining current levels of occurrence and possible risk from consumption. The project was conducted in two stages. The first stage included (a) a study that identified freshwater systems that are contaminated either by anthropogenic activity or as a result of the geology of the area; and (b) socioeconomic research to assess the consumption habits of the public, particularly anglers, with respect to fish and shellfish from unmanaged inland waterways. Based on the outcome from the first stage, specific rivers and other inland waterways were chosen for investigation, along with the range of contaminants to be included in the analytical programme. Predicted contamination levels and prevalence of anglers were among the factors taken into consideration. The second stage of the project involved sampling and analysis of fish taken from selected locations on the chosen waterways. A range of fish species from a variety of inland water habitats were obtained. These were analysed for the following contaminants: heavy metals, chlorinated dioxins (PCDD/Fs), polybrominated biphenyls (PBBs), polychlorinated biphenyls (PCBs), brominated dioxins (PBDD/Fs), polychlorinated naphthalenes (PCNs), polybrominated diphenylethers (PBDEs), OC pesticides, organotin compounds and organo-fluorine compounds. Legal limits for contaminants apply only to food traded commercially, but some samples

  9. Reduced total hardness of fresh water enhances the efficacy of bathing as a treatment for amoebic gill disease in Atlantic salmon, Salmo salar L.

    PubMed

    Roberts, S D; Powell, M D

    2003-10-01

    The current treatment for amoebic gill disease (AGD)-affected Atlantic salmon involves bathing sea-caged fish in fresh water, often sourced from local dams, for 3-4 h. In both a small-scale laboratory and an on-farm field experiment, the effects of water hardness on the efficacy of freshwater bathing were assessed. Results showed that soft fresh water (19.3-37.4 mg L(-1) CaCO3), whether it be naturally soft city mains water or artificially softened dam water, was more efficacious at alleviating AGD in affected fish than hard fresh water (173-236.3 mg L(-1) CaCO3). Soft freshwater bathing significantly reduced viable gill amoebae numbers (from 73.9 to 40.9% of total count) and significantly alleviated gill pathology, both gross and histological. Following bathing, gross gill pathological scores of soft freshwater bathed fish lagged 2 weeks behind hard freshwater bathed fish. Significant gill lesion fragmentation, and shedding of lesion-associated hyperplastic tissue, was accompanied by a significant reduction in AGD-affected gill filaments in soft freshwater bathed fish. Furthermore, soft freshwater bathing alleviated the blood plasma electrolyte imbalance seen in control (sea water) and hard freshwater bathed fish. This study showed that the use of soft fresh water for bathing AGD-affected Atlantic salmon could be an improvement to the current method of treatment. Not only does it reduce gill amoeba numbers, but also, it is of a therapeutic advantage with the potential to reduce bathing frequency.

  10. Reduced total hardness of fresh water enhances the efficacy of bathing as a treatment for amoebic gill disease in Atlantic salmon, Salmo salar L.

    PubMed

    Roberts, S D; Powell, M D

    2003-10-01

    The current treatment for amoebic gill disease (AGD)-affected Atlantic salmon involves bathing sea-caged fish in fresh water, often sourced from local dams, for 3-4 h. In both a small-scale laboratory and an on-farm field experiment, the effects of water hardness on the efficacy of freshwater bathing were assessed. Results showed that soft fresh water (19.3-37.4 mg L(-1) CaCO3), whether it be naturally soft city mains water or artificially softened dam water, was more efficacious at alleviating AGD in affected fish than hard fresh water (173-236.3 mg L(-1) CaCO3). Soft freshwater bathing significantly reduced viable gill amoebae numbers (from 73.9 to 40.9% of total count) and significantly alleviated gill pathology, both gross and histological. Following bathing, gross gill pathological scores of soft freshwater bathed fish lagged 2 weeks behind hard freshwater bathed fish. Significant gill lesion fragmentation, and shedding of lesion-associated hyperplastic tissue, was accompanied by a significant reduction in AGD-affected gill filaments in soft freshwater bathed fish. Furthermore, soft freshwater bathing alleviated the blood plasma electrolyte imbalance seen in control (sea water) and hard freshwater bathed fish. This study showed that the use of soft fresh water for bathing AGD-affected Atlantic salmon could be an improvement to the current method of treatment. Not only does it reduce gill amoeba numbers, but also, it is of a therapeutic advantage with the potential to reduce bathing frequency. PMID:14653317

  11. Qualitative toxicity assessment of silver nanoparticles on the fresh water bacterial isolates and consortium at low level of exposure concentration.

    PubMed

    Kumar, Deepak; Kumari, Jyoti; Pakrashi, Sunandan; Dalai, Swayamprava; Raichur, Ashok M; Sastry, T P; Mandal, A B; Chandrasekaran, N; Mukherjee, Amitava

    2014-10-01

    Silver nanoparticles (AgNPs) pose a high risk of exposure to the natural environment owing to their extensive usage in various consumer products. In the present study we attempted to understand the harmful effect of AgNPs at environmentally relevant low concentration levels (≤1ppm) towards two different freshwater bacterial isolates and their consortium. The standard plate count assay suggested that the AgNPs were toxic towards the fresh water bacterial isolates as well as the consortium, though toxicity was significantly reduced for the cells in the consortium. The oxidative stress assessment and membrane permeability studies corroborated with the toxicity data. The detailed electron microscopic studies suggested the cell degrading potential of the AgNPs, and the FT-IR studies confirmed the involvement of the surface groups in the toxic effects. No significant ion leaching from the AgNPs was observed at the applied concentration levels signifying the dominant role of the particle size, and size distribution in bacterial toxicity. The reduced toxicity for the cells in the consortium than the individual isolates has major significance in further studies on the ecotoxicity of the AgNPs.

  12. Cascade ultrafiltration and competing ligand exchange for kinetic speciation of aluminium, iron, and nickel in fresh water.

    PubMed

    Hassan, Nouri M; Murimboh, John D; Sekaly, Amina L R; Mandal, Rupasri; Chakrabarti, Chuni L; Grégoire, D Conrad

    2006-04-01

    Kinetic speciation of nickel, aluminium, and iron in fresh water has been investigated by cascade ultrafiltration followed by competing ligand exchange of the ultrafiltered fractions. Graphite furnace atomic absorption spectrometry was used to measure the kinetics of metal complex dissociation. Dissolved metal species were fractionated by cascade ultrafiltration. Metal speciation in each ultrafiltered fraction was then characterized as free metal ions, "labile" metal complexes (with dissociation rate constants >/=10(-3) s(-1)), "slowly labile" metal complexes (with dissociation rate constants >10(-6) s(-1)), and "inert" metal complexes (with dissociation rate constants <10(-6) s(-1)). The experimental results were compared with the predictions of a computer-based equilibrium speciation model, the Windermere humic aqueous model (WHAM) V. Cascade ultrafiltration coupled with kinetic speciation of the metal species in each molecular weight cut-off (MWCO) fraction provided a more comprehensive picture and insight into the physical and the chemical characteristics of the metal species than either ultrafiltration or measurement of dissociation kinetics alone.

  13. Reduced growth of coho salmon fry exposed to two petroleum components, toluene and naphthalene, in fresh water

    SciTech Connect

    Moles, A.; Bates, S.; Rice, S.D.; Korn, S.

    1981-05-01

    Coho salmon, Oncorhynchus kisutch, fry were exposed for 40 days to stable, sublethal concentrations of toluene (0.4, 0.8, 1.6, 3.2, 5.8 ..mu..l/liter) and naphthalene (0.2, 0.4, 0.7. 1.4 mg/liter) in fresh water. All fry were fed equal daily rations of Oregon Moist Pellet Formula II. Dry weights, wet weights, and lengths of fry exposed to the two highest concentrations of each toxicant for 40 days were significantly less than controls (P < 0.01). Growth per day, determined from weights and lengths, decreased linearly with increased concentrations. Fry exposed to naphthalene had a slower growth rate than fry exposed to equivalent concentrations (percentage of the 96-hour median lethal concentration or LC50) of toluene. Concentrations 18% of the LC50 of naphthalene and 26% of the LC50 of toluene had no effect on dry weight, wet weight, or length of exposed fry.

  14. The microstructures of biomineralized surfaces: a spectroscopic study on the exoskeletons of fresh water (Apple) snail, Pila globosa.

    PubMed

    Prasuna, C P Lakshmi; Narasimhulu, K V; Gopal, N O; Rao, J Lakshmana; Rao, T V R K

    2004-08-01

    In view of the importance in understanding biomineralization processes in different molluskan species, the common fresh water apple snail Pila globosa in Indian origin was taken to explore its mineralized exoskeleton structures. The detailed structural studies of the exoskeletons of P. globosa have been undertaken. The isolated layers present in these shells were studied by electron paramagnetic resonance (EPR), optical absorption, and infrared spectral techniques. The EPR spectra of the organic protein layer periostracum show the characteristic signals corresponding to Fe(3+) ions at g = 4.1 and 2.0. The EPR spectra of the ostracum (middle) layer at room temperature gives a complicated spectrum consisting of a number of Mn(2+) signals of at least three sets due to the aragonite nature of the material. The results indicate the presence of the multivalent manganese ions, which undergo the redox mechanisms. The thermal variation of the EPR spectra show marked effect on these samples both in g-values and the basic spectral pattern. PMID:15249020

  15. Hybrid male sterility between the fresh- and brackish-water types of ninespine stickleback Pungitius pungitius (Pisces, Gasterosteidae).

    PubMed

    Takahashi, Hiroshi; Nagai, Terumi; Goto, Akira

    2005-01-01

    Two ecologically distinct forms, fresh- and brackish-water types, of ninespine stickleback co-exist in several freshwater systems on the coast of eastern Hokkaido. Recent genetic analyses of 13 allozyme loci revealed genetic separation between the two types even though their spawning grounds were in close proximity. On the other hand, there is only a small difference in mitochondrial DNA (mtDNA) sequence between the two types suggesting that they diverged quite recently or that mtDNA introgression occurred between them. To test for postzygotic reproductive isolating mechanisms and hybrid mediated gene flow, we examined the viability and reproductive performance of reciprocal F1 hybrids. The hybrids grew to the adult size normally and both sexes expressed secondary sexual characters in the reciprocal crosses. The female hybrids were reciprocally fertile, while the male hybrids were reciprocally sterile. Histological and flow-cytometric analyses of the hybrid testis revealed that the sterility pattern was classified as 'gametic sterility,' with gonads of normal size but abnormal spermatogenesis. To our knowledge, the present finding is a novel example of one sex hybrid sterility in the stickleback family (Gasterosteidae).

  16. Determination of heavy metals in fresh water fish species of the River Ravi, Pakistan compared to farmed fish varieties.

    PubMed

    Nawaz, Shaista; Nagra, Saeed Ahmad; Saleem, Yasar; Priyadarshi, Amit; Priydarshi, Amit

    2010-08-01

    The untreated industrial and sewage wastes arising from industries and metropolitan activities make their passage to the River Ravi, Pakistan, where Balloki Headworks is one of the major sites of effluent concentration. This study was designed to evaluate the concentration of various toxic elements in fishes of that area compared to a nearby fish farm. The concentrations of heavy metals, such as As, Cd, Cu, Pb, Hg, and Zn, and electrolytes Ca, K, and Na were determined in different edible and non-edible fresh water fish varieties. Fish samples were collected from two selected sites and were analyzed for aforementioned elements. Higher levels of As (35.74-45.33 ppm), Cd (0.35-0.45 ppm), Pb (2.1-3.0 ppm), Hg (83.03-92.35 ppm) while normal levels of Zn (37.85-40.74 ppm) and Cu (1.39-2.93 ppm) were observed. Mercury, higher levels of which trigger cough, impairment of pulmonary function, and psychotic reactions, was significantly higher in all studied categories. At the sites under study, there has been observed alarming levels of toxic metals which are needed to be monitored regularly.

  17. Varying disease-mediated selection at different life-history stages of Atlantic salmon in fresh water.

    PubMed

    de Eyto, Elvira; McGinnity, Philip; Huisman, Jisca; Coughlan, Jamie; Consuegra, Sofia; Farrell, Killian; O'Toole, Ciar; Tufto, Jarle; Megens, Hendrik-Jan; Jordan, William; Cross, Tom; Stet, Rene J M

    2011-11-01

    Laboratory studies on associations between disease resistance and susceptibility and major histocompatibility (MH) genes in Atlantic salmon Salmo salar have shown the importance of immunogenetics in understanding the capacity of populations to fight specific diseases. However, the occurrence and virulence of pathogens may vary spatially and temporally in the wild, making it more complicated to predict the overall effect that MH genes exert on fitness of natural populations and over several life-history stages. Here we show that MH variability is a significant determinant of salmon survival in fresh water, by comparing observed and expected genotype frequencies at MH and control microsatellite loci at parr and migrant stages in the wild. We found that additive allelic effects at immunogenetic loci were more likely to determine survival than dominance deviation, and that selection on certain MH alleles varied with life stage, possibly owing to varying pathogen prevalence and/or virulence over time. Our results highlight the importance of preserving genetic diversity (particularly at MH loci) in wild populations, so that they have the best chance of adapting to new and increased disease challenges as a result of projected climate warming and increasing aquaculture.

  18. Carotenoid genes transcriptional regulation for astaxanthin accumulation in fresh water unicellular alga Haematococcus pluvialis by gibberellin A3 (GA3).

    PubMed

    Gao, Zhengquan; Meng, Chunxiao; Gao, Hongzheng; Li, Yan; Zhang, Xiaowen; Xu, Dong; Zhou, Shitan; Liu, Banghui; Su, Yuanfeng; Ye, Naihao

    2013-12-01

    The fresh water unicellular alga Haematococcus pluvialis is a promising natural source of astaxanthin. The present study investigated the transcriptional expression of carotenoid genes for astaxanthin accumulation in H. pluvialis using real-time fluorescence quantitative PCR (qRT-PCR). With treatments of 20 and 40 mg/L of gibberllin A3 (GA3), five genes ipi-1, ipi-2, psy, pds and bkt2 were up-regulated with different expression profiles. GA20 (20 mg/L of GA3) treatment had a greater effect on transcriptional expression of bkt2 than on ipi-1 ipi-2, psy and pds (> 4-fold up-regulation). However, GA40 (40 mg/L of GA3) induced more transcriptional expression of ipi-2, psy and bkt2 than both ipi-1 and pds. The expression of lyc, crtR-B and crtO for astaxanthin biosynthesis was not affected by GA3 in H. piuvialis. In the presence of GA3, astaxanthin biosynthesis genes of ipi-1, pds and bkt2 were up-regulated at transcriptional level, psy at post-transcriptional level, whereas ipi-2 was up-regulated at both levels. The study could potentially lead to a scale application of exogenous GA3 in astaxanthin production with H. pluvialis just like GAs perform in increasing crops production and it would provide new insight about the multifunctional roles of carotenogenesis in response to GA3. PMID:24772980

  19. Effects of (60)Co gamma irradiation on behavior and gill histoarchitecture of giant fresh water prawn Macrobrachium rosenbergii (DE MAN).

    PubMed

    Stalin, A; Broos, K V; Sadiq Bukhari, A; Syed Mohamed, H E; Singhal, R K; Venu-babu, P

    2013-06-01

    Present study was designed to observe the effects of (60)Co gamma radiation in behavioral and histological changes in the gills of giant fresh water prawn Macrobrachium rosenbergii. The adult prawns were irradiated with four different dose levels (3mGy, 30mGy, 300mGy and 3000mGy) and the control group (without irradiation) was maintained separately. Behavioral changes like hyperactivity, loss of balance, reduced swimming rate, slower rate of food intake and convulsions were observed in higher dose levels of 300mGy and 3000mGy. The histological alterations such as accumulated haemocytes in haemocoelic spaces, abnormal gill tips, lifted lamellar epithelium, swollen and fused lamellae, hyperplasic, necrotic, clavate-globate and complete disorganization of lamellae were observed in (60)Co gamma irradiated prawns. Significantly more considerable histological alterations were observed in the highest dose level of 3000mGy, but no mortality was evidenced. This study serves as biomonitoring tool to assess the radiation pollution in the aquatic environment.

  20. Varying disease-mediated selection at different life-history stages of Atlantic salmon in fresh water.

    PubMed

    de Eyto, Elvira; McGinnity, Philip; Huisman, Jisca; Coughlan, Jamie; Consuegra, Sofia; Farrell, Killian; O'Toole, Ciar; Tufto, Jarle; Megens, Hendrik-Jan; Jordan, William; Cross, Tom; Stet, Rene J M

    2011-11-01

    Laboratory studies on associations between disease resistance and susceptibility and major histocompatibility (MH) genes in Atlantic salmon Salmo salar have shown the importance of immunogenetics in understanding the capacity of populations to fight specific diseases. However, the occurrence and virulence of pathogens may vary spatially and temporally in the wild, making it more complicated to predict the overall effect that MH genes exert on fitness of natural populations and over several life-history stages. Here we show that MH variability is a significant determinant of salmon survival in fresh water, by comparing observed and expected genotype frequencies at MH and control microsatellite loci at parr and migrant stages in the wild. We found that additive allelic effects at immunogenetic loci were more likely to determine survival than dominance deviation, and that selection on certain MH alleles varied with life stage, possibly owing to varying pathogen prevalence and/or virulence over time. Our results highlight the importance of preserving genetic diversity (particularly at MH loci) in wild populations, so that they have the best chance of adapting to new and increased disease challenges as a result of projected climate warming and increasing aquaculture. PMID:25568020

  1. Ultimobranchial gland respond in a different way in male and female fresh water teleost Mastacembelus armatus (Lacepede) during reproductive cycle.

    PubMed

    Verma, Sushant Kumar; Alim, Abdul

    2015-05-01

    The present study was carried out to analyze the differences in the activity of ultimobranchial gland (UBG) between male and female fresh water teleost Mastacembelus armatus during reproductive cycle. Considerable variations in the nuclear diameter of UBG cells and plasma calcitonin (CT) levels during different reproductive phases of testicular and ovarian cycle suggested that the activity of the UBG depends upon the sexual maturity of fishes. A positive correlation was observed between plasma CT and sex steroid levels and the gonadosomatic index in both sexes which further confirmed the involvement of UBG in the processes related to gonadal development in fishes irrespective of the sex. Sudden increase in the level of plasma CT and nuclear diameter of UBG cells after administration of 17 α-methyltestosterone in males and 17 β-estradiol in females during resting phase of the reproductive cycle clearly showed that UBG becomes hyperactive with increases in the level of sex steroids. Plasma calcium level was also found to be positively correlated with gonadal maturation in females. However no such change in plasma calcium level in relation to testicular cycle was observed. Thus it can be concluded that UBG becomes hyperactive during gonadal maturation but its role differs between male and female fishes. In females it may involved in both gonadal maturation and plasma calcium regulation while in males its involvement in calcium regulation was not justified. Variations in the level of CT during various phases of testicular cycle evidenced its involvement in gonadal maturation only.

  2. Fresh Water Cyanobacteria Geitlerinema sp. CCC728 and Arthrospira sp. CCC729 as an Anticancer Drug Resource

    PubMed Central

    Tiwari, Ratnakar; Srivastava, Vikas

    2015-01-01

    An increasing number of cancer patients worldwide, especially in third world countries, have raised concern to explore natural drug resources, such as the less explored fresh water filamentous cyanobacteria. Six strains of cyanobacteria (Phormidium sp. CCC727, Geitlerinema sp. CCC728, Arthrospira sp. CCC729, Phormidium sp. CCC731, Phormidium sp. CCC730, and Leptolyngbya sp. CCC732) were isolated (paddy fields and ponds in the Banaras Hindu University, campus) and five strains screened for anticancer potential using human colon adenocarcinoma (HT29) and human kidney adenocarcinoma (A498) cancer cell lines. Geitlerinema sp. CCC728 and Arthrospira sp. CCC729 were the most potent as determined by examination of morphological features and by inhibition of growth by graded concentrations of crude extracts and thin-layer chromatography (TLC) eluates. Cell cycle analysis and multiplex assays using cancer biomarkers also confirmed Geitlerinema sp. CCC728 and Arthrospira sp. CCC729 as cancer drug resources. Apoptotic studies in the cells of A498 (cancer) and MCF-10A (normal human epithelial) exposed to crude extracts and TLC fractions revealed no significant impact on MCF-10A cells emphasizing its importance in the development of anticancer drug. Identification of biomolecules from these extracts are in progress. PMID:26325186

  3. Differential Suppressive Effects of Testosterone on Immune Function in Fresh Water Snake, Natrix piscator: An In Vitro Study

    PubMed Central

    Tripathi, Manish Kumar; Singh, Ramesh

    2014-01-01

    Reptiles represent the crucial phylogenetic group as they were the ancestors of both birds and mammals hence very important to study. The objectives of the present study were to investigate the potential roles of testosterone in the innate immune responses and splenic lymphocyte proliferation in fresh water snake, Natrix piscator. Animals were mildly anesthetized and spleens were taken out to study the splenic macrophage phagocytosis, super oxide production and nitrite release using in vitro testosterone. Splenic lymphocytes were isolated by density gradient centrifugation and were studied for mitogen induced proliferation in presence of in vitro testosterone. Testosterone suppressed the phagocytosis and nitrite release in a concentration dependent manner. Biphasic suppressive effect of testosterone was observed in superoxide production as judged by reduction of nitroblue tetrazolium salt where salt reduction was suppressed at lower and higher concentrations of testosterone. Mitogen induced splenic lymphocyte proliferation was also suppressed by testosterone. By suppressing immune responses, testosterone may, therefore, act as a physiological mechanism regulating the relative amount of energy invested into either reproductive effort or immunocompetence. PMID:25101765

  4. Use of whole-body and subcellular Cu residues of Lumbriculus variegatus to predict waterborne Cu toxicity to both L. variegatus and Chironomus riparius in fresh water.

    PubMed

    Ng, Tania Y T; Pais, Nish M; Dhaliwal, Tarunpreet; Wood, Chris M

    2012-06-01

    We tested the use of whole-body and subcellular Cu residues (biologically-active (BAM) and inactive compartments (BIM)), of the oligochaete Lumbriculus variegatus to predict Cu toxicity in fresh water. The critical whole-body residue associated with 50% mortality (CBR(50)) was constant (38.2-55.6 μg g(-1) fresh wt.) across water hardness (38-117 mg L(-1) as CaCO(3)) and exposure times during the chronic exposure. The critical subcellular residue (CSR(50)) in metal-rich granules (part of BIM) associated with 50% mortality was approximately 5 μg g(-1) fresh wt., indicating that Cu bioavailability is correlated with toxicity:subcellular residue is a better predictor of Cu toxicity than whole-body residue. There was a strong correlation between the whole-body residue of L. variegatus (biomonitor) and survival of Chironomus riparius (relatively sensitive species) in a hard water Cu co-exposure. The CBR(50) in L. variegatus for predicting mortality of C. riparius was 29.1-45.7 μg g(-1) fresh wt., which was consistent within the experimental period; therefore use of Cu residue in an accumulator species to predict bioavailability of Cu to a sensitive species is a promising approach.

  5. An algorithm based on sea level pressure fluctuations to identify major Baltic inflow events

    NASA Astrophysics Data System (ADS)

    Schimanke, Semjon; Dieterich, Christian; Markus Meier, H. E.

    2014-05-01

    The Baltic Sea is one of world largest brackish water areas with an estuarine like circulation. It is connected to the world ocean through the narrow Danish straits limiting the exchange of water masses. The deep water of the Baltic Sea is mainly renewed by so called major Baltic inflows which are an important feature to sustain the sensitive steady state of the Baltic Sea. We introduce an algorithm to identify atmospheric variability favourable for major Baltic inflows. The algorithm is based on sea level pressure fields as the only parameter. Characteristic sea level pressure pattern fluctuations include a precursory phase of 30 days and 10 days of inflow period. The algorithm identifies successfully the majority of observed major Baltic inflows between 1961--2010. In addition, the algorithm finds some occurrences which cannot be related to observed inflows. In these cases with favourable atmospheric conditions inflows were precluded by contemporaneously existing saline water masses or strong freshwater supply. No event is registered during the stagnation period 1983-1993 indicating that the lack of inflows is a consequence of missing favourable atmospheric variability. The only striking inflow which is not identified by the algorithm is the event in January 2003. We demonstrate that this is due to the special evolution of sea level pressure fields which are not comparable with any other event. Finally, the algorithm is applied to an ensemble of scenario simulations. The result indicates that the number of atmospheric events favourable for major Baltic inflows increases slightly in all scenarios. Possible explanations as for instance more frequent atmospheric blockings or changes in the NAO will be discussed.

  6. Toxicity of crude oil to fresh water shrimp, Macrobrachium macrobrachion and Macrobrachium vollenhovenii, from Nigerian coastal water.

    PubMed

    Ekanem, A P; Asuquo, F Emile; Ndick, E J

    2011-04-01

    The water soluble fraction (WSF) of crude oil was tested against Macrobrachium macrobrachion and Macrobrachium vollenhovenii, at 2, 4, 6, 8 and 10 mg/L in glass aquaria stocked with ten animals for 96 h under observations for changes. Moribund swimming, restlessness, respiratory difficulties, depigmentation and mortalities were observed in the WSF exposure groups, but not in the controls. LC(50) values were estimated at 5 ± 1.76 and 4 ± 1.76 mg/L for M. macrobrachion and M. vollenhovenii respectively. There was no significant difference in mortalities between the two species (p > 0.05), leading to the conclusion that the WSF of crude oil in the Nigerian coastal waters may be equally toxic to M. macrobrachion and M. vollenhovenii.

  7. Assessing the Role of Dune Topography on a Fresh Water Lens of a Siliciclastic Barrier Along the Northern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Anderson, C. P.; Carter, G. A.; Mooneyhan, D.

    2013-12-01

    Carlton P. Anderson, Gregory Carter, and David Mooneyhan University of Southern Mississippi Gulf Coast Geospatial Center Department of Geography and Geology Carlton.p.anderson@eagles.usm.edu The Mississippi-Alabama (MS-AL) barrier island chain consist of dynamic depositional landforms that constantly undergo changes in their evolutionary processes through changes in sea level, sediment supply, and weather events. These complex landscapes of the Northern Gulf of Mexico (NGOM) provide a chance to study their geomorphological progressions, which have been produced by sea level rise and fluvial processes throughout the Holocene. Studies on the freshwater lens of barriers have mainly concentrated on carbonate island settings with minimal focus to barriers with siliciclastic geology. The purpose of this study is to examine the relationship beach dune topography plays in the development and sustainability of the fresh water lens of Cat Island, Mississippi. Cat Island offers the opportunity to research a siliciclastic barrier along the NGOM where minimal anthropogenic activities have taken place. To determine the effect dune topography has on the fresh water lens, a transect of permanent water wells were used in conjunction with test wells at different sites throughout the north spit of the island, to establish the water table height above the ellipsoid (WGS 84), with vertical accuracies of 2 cm. Cross-sectional profiles of the dunes were also performed utilizing purposeful transects that intersected fresh water ponds in the dune-swale systems. These ponds provide water table elevations at the surface which were interpolated across the dunes for areas that lacked permanent well sites. To obtain survey-grade accuracies, a Trimble TSC3 receiver coupled with a R8 antennae RTK system were used. Salinity measurements were taken at test sites to determine the salt-to-freshwater interface. Results provide insights into how dune topography influences the fresh water lens of a

  8. Chronic toxicity of water-soluble fractions of fresh and water-leached solvent refined coal-II liquids to a freshwater benthic invertebrate

    SciTech Connect

    Dauble, D.D.; Fallon, W.E.; Gray, R.H.; Bean, R.M.

    1981-01-01

    A solvent refined coal (SRC-II) liquid blend (2.9:1, middle to heavy distillate) obtained from a pilot plant was sequentially extracted with water to observe compositional changes in water soluble fractions (WSF). An initial WSF, designed to simulate chemicals present after contact with water, and a water-leached (artificially weathered) WSF, designed to represent conditions after exposure to the aqueous environment were chemically characterized. Toxicities of the two WSFs were compared by observing chronic effects on a freshwater benthic invertebrate, Tanytarsus dissimilis. Survival to emergence was suppressed at 3.0 ppth of the initial WSF and at 9.4 ppth of the artificially weathered WSF. However, based on equal concentrations of organic carbon and phenolics, weathered WSF solutions were three to five times more toxic. Concentrations, relative distributions, and loss over time of phenols and aromatic hydrocarbons differed between aqueous extractions derived from the fresh and weathered SRC II material. Tests assessing long-term effects of complex materials must be designed and interpreted on the basis of organism exposure to compounds most likely to persist in the environment.

  9. Influence of aluminium on the restoration potential of a terrestrial vascular plant, Portulaca Oleracea L. as a biomonitoring tool of fresh water aquatic environments.

    PubMed

    Anandi, S; Thangavel, P; Subburam, V

    2002-08-01

    In the present study, the influence of aluminium on the regeneration potential of leaf and stem-cuttings of Portulaca oleracea was studied in order to identify a terrestrial plant species as an alternate biomonitoring tool of fresh water environment. The leaves and stem cuttings of the terrestrial plant, P. oleracea grew well in the distilled water producing adventitious and lateral roots. The aluminium treated leaves and stem cuttings showed a reduction in the growth of the adventitious and lateral roots and increase in the decay of leaves and stem cuttings with increasing aluminium concentration. The tolerance index calculated for the leaves and the stem cuttings showed that the leaves were more sensitive than stems to aluminium. Since all the parameters studied showed concentration dependent changes, the terrestrial plant, P oleracea can be considered a suitable 'biomonitoring tool' of fresh water environment besides its usage in the Al toxicity testing. PMID:12197638

  10. 1D and 3D inversion of VES data to outline a fresh water zone floating over saline water body at the northwestern coast of Egypt

    NASA Astrophysics Data System (ADS)

    Massoud, Usama; Soliman, Mamdouh; Taha, Ayman; Khozym, Ashraf; Salah, Hany

    2015-12-01

    Seawater intrusion is a widespread environmental problem in the Egyptian coastal aquifers. It affects the groundwater used in domestic and agricultural activities along these coasts. In this study, resistivity survey in the form of Vertical Electrical Sounding (VES) was conducted at ZAWYET EL HAWALA cultivated site, northwest coast of Egypt to outline a freshwater zone overlies the main saltwater body, and to determine the most suitable location for drilling water well for irrigation purposes. The VES data were measured at 11 stations in the studied site. After processing, the data were inverted in 1-D and 3-D schemes and the final model was presented as resistivity slices with depth. The results indicate that the effect of saltwater intrusion was observed, as low resistivity values, at 7.5 m below ground surface (bgs) at the northern part of the study area (toward the Mediterranean Sea), and extends southward with increasing depth covering the whole area at about 30 m bgs. The fresh water zone shows a minimum thickness of less than 7.5 m at the northern side and a maximum thickness of about 20 m at the southern side of the area. The proper site for drilling water well tap and the freshwater zone is the location of VES6 or VES9 with a maximum well depth of about 20 m bgs. The water withdrawal from the proposed well should be controlled not to raise the main saline water table in the well site. The main sources of the freshwater zone are the rainfall and surface runoff descending from the southern tableland. Excess rainfall and surface runoff can be avoided from direct discharge to the sea by collecting them in man-made outlined trenches and re-using the stored water in irrigation during the dry seasons.

  11. Cell proliferation and cytoarchitectural remodeling during spinal cord reconnection in the fresh-water turtle Trachemys dorbignyi

    PubMed Central

    Rehermann, María Inés; Santiñaque, Federico Fernando; López-Carro, Beatriz; Russo, Raúl E.

    2011-01-01

    In fresh-water turtles, the bridge connecting the proximal and caudal stumps of transected spinal cords consists of regenerating axons running through a glial cellular matrix. To understand the process leading to the generation of the scaffold bridging the lesion, we analyzed the mitotic activity triggered by spinal injury in animals maintained alive for 20–30 days after spinal cord transection. Flow cytometry and bromodeoxyuridine (BrdU)-labeling experiments revealed a significant increment of cycling cells around the lesion epicenter. BrdU-tagged cells maintained a close association with regenerating axons. Most dividing cells expressed the brain lipid-binding protein (BLBP). Cells with BrdU-positive nuclei expressed glial fibrillary acidic protein. As spinal cord regeneration involves dynamic cell rearrangements, we explored the ultra-structure of the bridge and found cells with the aspect of immature oligodendrocytes forming an embryonic-like microenvironment. These cells supported and ensheathed regenerating axons that were recognized by immunocytological and electron-microscopical procedures. Since functional recovery depends on proper impulse transmission, we examined the anatomical axon-glia relationships near the lesion epicenter. Computer-assisted three-dimensional models revealed helical axon-glial junctions in which the intercellular space appeared to be reduced (5–7 nm). Serial-sectioning analysis revealed that fibril-containing processes provided myelinating axon sheaths. Thus, disruption of the ependymal layer elicits mitotic activity predominantly in radial glia expressing BLBP on the lateral aspects of the ependyma. These cycling cells seem to migrate and contribute to the bridge providing the main support and sheaths for regenerating axons. PMID:21574060

  12. Enantioselective ecotoxicity of the herbicide dichlorprop and complexes formed with chitosan in two fresh water green algae.

    PubMed

    Wen, Yuezhong; Chen, Hui; Yuan, Yuli; Xu, Dongmei; Kang, Xiaodong

    2011-04-01

    To reduce the leaching potential, to prevent groundwater contamination and to maintain the efficacy of a pesticide, natural polysaccharides have received increasing attention due to their biocompatibility and useful biological reactivity for controlled release formulations (CRFs) of pesticides. In this paper, the toxicities of the chiral herbicide dichlorprop (DCPP) and its complexes with chitosan molecules (DCPP-CS) and chitosan nanoparticles (DCPP-NP) to two different green algae were determined and compared. The inhibition rates of DCPP, DCPP-CS and DCPP-NP were determined at 24, 48, 72, 96, 120, 144, 168 h, and the results show that (S)-DCPP was more toxic to Chlorella vulgaris than (R)-DCPP, while the (R)-DCPP was more toxic to Scenedesmus obliquus than (S)-DCPP. The study also found that the chiral selectivity of DCPP to Chlorella vulgaris and Scenedesmus obliquus could be changed when DCPP was complexed with chitosan molecules (CS) or chitosan nanoparticles (NP). For Chlorella vulgaris, the order of inhibition was (R)-DCPP-CS > (S)-DCPP-CS and (R)-DCPP-NP > (S)-DCPP-NP; for Scenedesmus obliquus, the order was (S)-DCPP-CS > (R)-DCPP-CS and (S)-DCPP-NP > (R)-DCPP-NP. This phenomenon suggests that the enantioselective behaviors of chiral compounds might shift when interactions with other chiral receptors coexist in different biological environments. Additionally, chitosan molecules and chitosan nanoparticles also showed different toxicities, which could be ascribed to the difference in the physicochemical properties between CS and NP or the differences in the cell walls of the two fresh water green algae.

  13. A mammalian melanopsin in the retina of a fresh water turtle, the red-eared slider (Trachemys scripta elegans).

    PubMed

    Dearworth, James R; Selvarajah, Brian P; Kalman, Ross A; Lanzone, Andrew J; Goch, Abraham M; Boyd, Alison B; Goldberg, Laura A; Cooper, Lori J

    2011-01-28

    A mammalian-like melanopsin (Opn4m) has been found in all major vertebrate classes except reptile. Since the pupillary light reflex (PLR) of the fresh water turtle takes between 5 and 10 min to achieve maximum constriction, and since photosensitive retinal ganglion cells (ipRGCs) in mammals use Opn4m to control their slow sustained pupil responses, we hypothesized that a Opn4m homolog exists in the retina of the turtle. To identify its presence, retinal tissue was dissected from seven turtles, and total RNA extracted. Reverse transcriptase-polymerase chain reactions (RT-PCRs) were carried out to amplify gene sequences using primers targeting the highly conserved core region of Opn4m, and PCR products were analyzed by gel electrophoresis and sequenced. Sequences derived from a 1004-bp PCR product were compared to those stored in GenBank by the basic local alignment search tool (BLAST) algorithm and returned significant matches to several Opn4ms from other vertebrates including chicken. Quantitative real-time PCR (qPCR) was also carried out to compare expression levels of Opn4m in different tissues. The normalized expression level of Opn4m in the retina was higher in comparison to other tissue types: iris, liver, lung, and skeletal muscle. The results suggest that Opn4m exists in the retina of the turtle and provides a possible explanation for the presence of a slow PLR. The turtle is likely to be a useful model for further understanding the photoreceptive mechanisms in the retina which control the dynamics of the PLR. PMID:21050869

  14. Cell proliferation and cytoarchitectural remodeling during spinal cord reconnection in the fresh-water turtle Trachemys dorbignyi.

    PubMed

    Rehermann, María Inés; Santiñaque, Federico Fernando; López-Carro, Beatriz; Russo, Raúl E; Trujillo-Cenóz, Omar

    2011-06-01

    In fresh-water turtles, the bridge connecting the proximal and caudal stumps of transected spinal cords consists of regenerating axons running through a glial cellular matrix. To understand the process leading to the generation of the scaffold bridging the lesion, we analyzed the mitotic activity triggered by spinal injury in animals maintained alive for 20-30 days after spinal cord transection. Flow cytometry and bromodeoxyuridine (BrdU)-labeling experiments revealed a significant increment of cycling cells around the lesion epicenter. BrdU-tagged cells maintained a close association with regenerating axons. Most dividing cells expressed the brain lipid-binding protein (BLBP). Cells with BrdU-positive nuclei expressed glial fibrillary acidic protein. As spinal cord regeneration involves dynamic cell rearrangements, we explored the ultra-structure of the bridge and found cells with the aspect of immature oligodendrocytes forming an embryonic-like microenvironment. These cells supported and ensheathed regenerating axons that were recognized by immunocytological and electron-microscopical procedures. Since functional recovery depends on proper impulse transmission, we examined the anatomical axon-glia relationships near the lesion epicenter. Computer-assisted three-dimensional models revealed helical axon-glial junctions in which the intercellular space appeared to be reduced (5-7 nm). Serial-sectioning analysis revealed that fibril-containing processes provided myelinating axon sheaths. Thus, disruption of the ependymal layer elicits mitotic activity predominantly in radial glia expressing BLBP on the lateral aspects of the ependyma. These cycling cells seem to migrate and contribute to the bridge providing the main support and sheaths for regenerating axons. PMID:21574060

  15. IN-SITU IONIC CHEMICAL ANALYSIS OF FRESH WATER VIA A NOVEL COMBINED MULTI-SENSOR / SIGNAL PROCESSING ARCHITECTURE

    NASA Astrophysics Data System (ADS)

    Mueller, A. V.; Hemond, H.

    2009-12-01

    The capability for comprehensive, real-time, in-situ characterization of the chemical constituents of natural waters is a powerful tool for the advancement of the ecological and geochemical sciences, e.g. by facilitating rapid high-resolution adaptive sampling campaigns and avoiding the potential errors and high costs related to traditional grab sample collection, transportation and analysis. Portable field-ready instrumentation also promotes the goals of large-scale monitoring networks, such as CUASHI and WATERS, without the financial and human resources overhead required for traditional sampling at this scale. Problems of environmental remediation and monitoring of industrial waste waters would additionally benefit from such instrumental capacity. In-situ measurement of all major ions contributing to the charge makeup of natural fresh water is thus pursued via a combined multi-sensor/multivariate signal processing architecture. The instrument is based primarily on commercial electrochemical sensors, e.g. ion selective electrodes (ISEs) and ion selective field-effect transistors (ISFETs), to promote low cost as well as easy maintenance and reproduction,. The system employs a novel architecture of multivariate signal processing to extract accurate information from in-situ data streams via an "unmixing" process that accounts for sensor non-linearities at low concentrations, as well as sensor cross-reactivities. Conductivity, charge neutrality and temperature are applied as additional mathematical constraints on the chemical state of the system. Including such non-ionic information assists in obtaining accurate and useful calibrations even in the non-linear portion of the sensor response curves, and measurements can be made without the traditionally-required standard additions or ionic strength adjustment. Initial work demonstrates the effectiveness of this methodology at predicting inorganic cations (Na+, NH4+, H+, Ca2+, and K+) in a simplified system containing

  16. The Comparative Osmoregulatory Ability of Two Water Beetle Genera Whose Species Span the Fresh-Hypersaline Gradient in Inland Waters (Coleoptera: Dytiscidae, Hydrophilidae)

    PubMed Central

    Pallarés, Susana; Arribas, Paula; Bilton, David T.; Millán, Andrés; Velasco, Josefa

    2015-01-01

    A better knowledge of the physiological basis of salinity tolerance is essential to understanding the ecology and evolutionary history of organisms that have colonized inland saline waters. Coleoptera are amongst the most diverse macroinvertebrates in inland waters, including saline habitats; however, the osmoregulatory strategies they employ to deal with osmotic stress remain unexplored. Survival and haemolymph osmotic concentration at different salinities were examined in adults of eight aquatic beetle species which inhabit different parts of the fresh—hypersaline gradient. Studied species belong to two unrelated genera which have invaded saline waters independently from freshwater ancestors; Nebrioporus (Dytiscidae) and Enochrus (Hydrophilidae). Their osmoregulatory strategy (osmoconformity or osmoregulation) was identified and osmotic capacity (the osmotic gradient between the animal’s haemolymph and the external medium) was compared between species pairs co-habiting similar salinities in nature. We show that osmoregulatory capacity, rather than osmoconformity, has evolved independently in these different lineages. All species hyperegulated their haemolymph osmotic concentration in diluted waters; those living in fresh or low-salinity waters were unable to hyporegulate and survive in hyperosmotic media (> 340 mosmol kg-1). In contrast, the species which inhabit the hypo-hypersaline habitats were effective hyporegulators, maintaining their haemolymph osmolality within narrow limits (ca. 300 mosmol kg-1) across a wide range of external concentrations. The hypersaline species N. ceresyi and E. jesusarribasi tolerated conductivities up to 140 and 180 mS cm-1, respectively, and maintained osmotic gradients over 3500 mosmol kg-1, comparable to those of the most effective insect osmoregulators known to date. Syntopic species of both genera showed similar osmotic capacities and in general, osmotic responses correlated well with upper salinity levels occupied by

  17. Toxic potential of iron oxide, CdS/Ag₂S composite, CdS and Ag₂S NPs on a fresh water alga Mougeotia sp.

    PubMed

    Jagadeesh, E; Khan, Behlol; Chandran, Preethy; Khan, S Sudheer

    2015-01-01

    Nanoparticles (NPs) are being used in many industries ranging from medical, textile, automobile, consumer products, etc. This may increase the probability of their (NPs) release into the environment and fresh water ecosystems. The present study focuses on testing the potential effect of iron oxide, nanocomposite of cadmium sulfide and silver sulfide, cadmium sulfide and silver sulfide nanoparticles (NPs) on a fresh water alga Mougeotia sp. as the model organism. The alga was treated with different concentrations of NPs (0.1-25 mg/L). The NPs exposure caused lipid peroxidation and ROS production, and suppressed the antioxidant defense system such as catalase, glutathione reductase, and superoxide dismutase. Adsorption of NPs on algal surface and membrane damage were confirmed through microscopic evaluation and increase in protein content in extracellular medium. The present investigation pointed out the ecological implications of NPs. The study warrants the need for regulatory agencies to monitor and regulate the use of NPs. PMID:25465759

  18. Toxic potential of iron oxide, CdS/Ag₂S composite, CdS and Ag₂S NPs on a fresh water alga Mougeotia sp.

    PubMed

    Jagadeesh, E; Khan, Behlol; Chandran, Preethy; Khan, S Sudheer

    2015-01-01

    Nanoparticles (NPs) are being used in many industries ranging from medical, textile, automobile, consumer products, etc. This may increase the probability of their (NPs) release into the environment and fresh water ecosystems. The present study focuses on testing the potential effect of iron oxide, nanocomposite of cadmium sulfide and silver sulfide, cadmium sulfide and silver sulfide nanoparticles (NPs) on a fresh water alga Mougeotia sp. as the model organism. The alga was treated with different concentrations of NPs (0.1-25 mg/L). The NPs exposure caused lipid peroxidation and ROS production, and suppressed the antioxidant defense system such as catalase, glutathione reductase, and superoxide dismutase. Adsorption of NPs on algal surface and membrane damage were confirmed through microscopic evaluation and increase in protein content in extracellular medium. The present investigation pointed out the ecological implications of NPs. The study warrants the need for regulatory agencies to monitor and regulate the use of NPs.

  19. Simulated peak inflows for glacier dammed Russell Fiord, near Yakutat, Alaska

    USGS Publications Warehouse

    Neal, Edward G.

    2004-01-01

    In June 2002, Hubbard Glacier advanced across the entrance to 35-mile-long Russell Fiord creating a glacier-dammed lake. After closure of the ice and moraine dam, runoff from mountain streams and glacial melt caused the level in ?Russell Lake? to rise until it eventually breached the dam on August 14, 2002. Daily mean inflows to the lake during the period of closure were estimated on the basis of lake stage data and the hypsometry of Russell Lake. Inflows were regressed against the daily mean streamflows of nearby Ophir Creek and Situk River to generate an equation for simulating Russell Lake inflow. The regression equation was used to produce 11 years of synthetic daily inflows to Russell Lake for the 1992-2002 water years. A flood-frequency analysis was applied to the peak daily mean inflows for these 11 years of record to generate a 100-year peak daily mean inflow of 235,000 cubic feet per second. Regional-regression equations also were applied to the Russell Lake basin, yielding a 100-year inflow of 157,000 cubic feet per second.

  20. Lateral groundwater inflows into alluvial aquifers of main alpine valleys

    NASA Astrophysics Data System (ADS)

    Burger, Ulrich

    2015-04-01

    ; congress of IAEG, Engineering Geology for Society and Territory, Torino Burger U., San Nicoló L. Bösel D. und Perello P. (2012): Hydrogeologische Modelle - Hilfsmittel für die Planung am Beispiel des Brenner Basistunnel, Beiträge zur Beiträge zur COGeo 2011, Salzburg COGEO Perello P., Baietto A., Burger U., Skuk S. (2013): Excavation of the Aica-Mules pilot tunnel for the Brenner base tunnel: information gained on water inflows in tunnels in granitic massifs, Rock Mechanics and Rock Engineering, DOI 10.1007/s00603-013-0480-x

  1. 40 CFR 35.927-1 - Infiltration/inflow analysis.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 1 2012-07-01 2012-07-01 false Infiltration/inflow analysis. 35.927-1... Infiltration/inflow analysis. (a) The infiltration/inflow analysis shall demonstrate the nonexistence or possible existence of excessive infiltration/inflow in the sewer system. The analysis should identify...

  2. 40 CFR 35.927-1 - Infiltration/inflow analysis.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Infiltration/inflow analysis. 35.927-1... Infiltration/inflow analysis. (a) The infiltration/inflow analysis shall demonstrate the nonexistence or possible existence of excessive infiltration/inflow in the sewer system. The analysis should identify...

  3. 40 CFR 35.927-1 - Infiltration/inflow analysis.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Infiltration/inflow analysis. 35.927-1... Infiltration/inflow analysis. (a) The infiltration/inflow analysis shall demonstrate the nonexistence or possible existence of excessive infiltration/inflow in the sewer system. The analysis should identify...

  4. 40 CFR 35.927-1 - Infiltration/inflow analysis.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Infiltration/inflow analysis. 35.927-1... Infiltration/inflow analysis. (a) The infiltration/inflow analysis shall demonstrate the nonexistence or possible existence of excessive infiltration/inflow in the sewer system. The analysis should identify...

  5. Anatomizing one of the largest saltwater inflows into the Baltic Sea in December 2014

    NASA Astrophysics Data System (ADS)

    Gräwe, Ulf; Naumann, Michael; Mohrholz, Volker; Burchard, Hans

    2015-11-01

    In December 2014, an exceptional inflow event into the Baltic Sea was observed, a so-called Major Baltic Inflow (MBI). Such inflow events are important for the deep water ventilation in the Baltic Sea and typically occur every 3-10 years. Based on first observational data sets, this inflow had been ranked as the third largest since 100 years. With the help of a multinested modeling system, reaching from the North Atlantic (8 km resolution) to the Western Baltic Sea (600 m resolution, which is baroclinic eddy resolving), this event is reproduced in detail. The model gave a slightly lower salt transport of 3.8 Gt, compared to the observational estimate of four Gt. Moreover, by using passive tracers to mark the different inflowing water masses, including an age tracer, the inflowing water masses could be tracked and their paths and timing through the different basins could be reproduced and investigated. The analysis is supported by the recently developed Total Exchange Flow (TEF) to quantify the volume transport in different salinity classes. To account for uncertainties in the modeled velocity and tracer fields, a Monte Carlo Analysis (MCA) is applied to correct possible biases and errors. With the help of the MCA, 95% confidence intervals are computed for the transport estimates. Based on the MCA, the "best guess" of the volume transport is 291.0 ± 13.65 km3 and 3.89 ± 0.18 Gt for the total salt transport.

  6. Assessment of climate and land use changes impacts on the rivers inflow to the Lake Baikal

    NASA Astrophysics Data System (ADS)

    Kurovskaia, Victoriia; Semenova, Olga; Vinogradova, Tatyana

    2016-04-01

    Baikal is the deepest lake in the world and one of the biggest reservoirs of fresh water. The aim of this research was to analyze the long-term variability of characteristics of river inflow to the Lake using the historical data and project possible changes in the face of non-stationary climate and land use based on hydrological modelling. The basin of the Lake Baikal has area about 545 000 km2, half of which is situated in Russia. It is characterized by different climate and landscape conditions with annual flow depth varying from 30 to more than 600 mm. Nowadays active development and use of natural resources as well as climate changes have a strong impact on the regime of rivers inflow to the Lake. The watersheds response caused by environmental non-stationarity can be variable and unpredictable. Therefore adequate hydrological models with robust parametrization are required for future projections. This study consisted of two parts. Initially we compiled the database of daily runoff data for about 50 gauges in the basin of the Baikal Lake with continuous period of observations 30-50 years. The data was used to assess the characteristics of river inflow to the Lake for the historical period and estimate observed changes due to current climate change. For the development of future projections we have chosen several small and middle-size representative watersheds in different parts of the Lake basin with area from 151 to 7800 km2 and various types of hydrological regime. The data base for modelling was developed which included the information about landscapes, soils, dominating hydrological processes. The hydrological model parameters for different dominant landscapes were estimated based on that information. We applied distributed process-based hydrological model Hydrograph developed in State Hydrological Institute, Russia (Vinogradov et al., 2011; Semenova et al., 2013). It describes all essential processes of land hydrological cycle including detailed algorithm

  7. DNA adduct measurements in zebra mussels, Dreissena polymorpha, Pallas. Potential use for genotoxicant biomonitoring of fresh water ecosystems.

    PubMed

    Le Goff, J; Gallois, J; Pelhuet, L; Devier, M H; Budzinski, H; Pottier, D; André, V; Cachot, J

    2006-08-12

    biomarker to monitor PAH-exposure and evaluate genotoxicity in fresh water ecosystems.

  8. Radium isotopes in Cayuga Lake, New York: Indicators of inflow and mixing processes

    USGS Publications Warehouse

    Kraemer, T.F.

    2005-01-01

    Naturally occurring radium isotopes (223Ra, 224Ra, 226Ra, and 228Ra) were measured in lake and tributary water of Cayuga Lake, New York, during the course of a vernal inflow event in the spring of 2001. A large influx of groundwater, probably from a carbonate aquifer, entered the lake at its extreme southern end early in the vernal inflow event and spread northward, covering an extensive part of the southern end of the lake. The low 228Ra/226Ra activity ratio of this water mass, compared with bulk lake water, allowed its identification through time. Estimates of mixing with bulk lake water were calculated from changes in the 226Ra content. Groundwater inflow to the lake around the delta of a major tributary was detected on the basis of 223Ra and 224Ra activity of lake and tributary water. Inflow of a water mass to the surface of the lake was also detected using 223Ra and 224Ra activity. The integrity of this water mass was monitored using short-lived radium isotopes. Suspended sediment in the lake water is a source of the short-lived radium isotopes 223Ra (???2 ?? 10 -4 dpm L-1) and 224Ra (???3 ?? 10 -3 dpm L-1), but bottom sediments are a more significant source of 228Ra. Radium isotopes can be valuable new tools in limnological investigations, allowing detection and monitoring of events and processes such as water inflow and mixing, determining sources of inflowing water, and monitoring introduced water masses as they move within the lake.

  9. Methodology for modeling the disinfection efficiency of fresh-cut leafy vegetables wash water applied on peracetic acid combined with lactic acid.

    PubMed

    Van Haute, S; López-Gálvez, F; Gómez-López, V M; Eriksson, Markus; Devlieghere, F; Allende, Ana; Sampers, I

    2015-09-01

    A methodology to i) assess the feasibility of water disinfection in fresh-cut leafy greens wash water and ii) to compare the disinfectant efficiency of water disinfectants was defined and applied for a combination of peracetic acid (PAA) and lactic acid (LA) and comparison with free chlorine was made. Standardized process water, a watery suspension of iceberg lettuce, was used for the experiments. First, the combination of PAA+LA was evaluated for water recycling. In this case disinfectant was added to standardized process water inoculated with Escherichia coli (E. coli) O157 (6logCFU/mL). Regression models were constructed based on the batch inactivation data and validated in industrial process water obtained from fresh-cut leafy green processing plants. The UV254(F) was the best indicator for PAA decay and as such for the E. coli O157 inactivation with PAA+LA. The disinfection efficiency of PAA+LA increased with decreasing pH. Furthermore, PAA+LA efficacy was assessed as a process water disinfectant to be used within the washing tank, using a dynamic washing process with continuous influx of E. coli O157 and organic matter in the washing tank. The process water contamination in the dynamic process was adequately estimated by the developed model that assumed that knowledge of the disinfectant residual was sufficient to estimate the microbial contamination, regardless the physicochemical load. Based on the obtained results, PAA+LA seems to be better suited than chlorine for disinfecting process wash water with a high organic load but a higher disinfectant residual is necessary due to the slower E. coli O157 inactivation kinetics when compared to chlorine.

  10. Methodology for modeling the disinfection efficiency of fresh-cut leafy vegetables wash water applied on peracetic acid combined with lactic acid.

    PubMed

    Van Haute, S; López-Gálvez, F; Gómez-López, V M; Eriksson, Markus; Devlieghere, F; Allende, Ana; Sampers, I

    2015-09-01

    A methodology to i) assess the feasibility of water disinfection in fresh-cut leafy greens wash water and ii) to compare the disinfectant efficiency of water disinfectants was defined and applied for a combination of peracetic acid (PAA) and lactic acid (LA) and comparison with free chlorine was made. Standardized process water, a watery suspension of iceberg lettuce, was used for the experiments. First, the combination of PAA+LA was evaluated for water recycling. In this case disinfectant was added to standardized process water inoculated with Escherichia coli (E. coli) O157 (6logCFU/mL). Regression models were constructed based on the batch inactivation data and validated in industrial process water obtained from fresh-cut leafy green processing plants. The UV254(F) was the best indicator for PAA decay and as such for the E. coli O157 inactivation with PAA+LA. The disinfection efficiency of PAA+LA increased with decreasing pH. Furthermore, PAA+LA efficacy was assessed as a process water disinfectant to be used within the washing tank, using a dynamic washing process with continuous influx of E. coli O157 and organic matter in the washing tank. The process water contamination in the dynamic process was adequately estimated by the developed model that assumed that knowledge of the disinfectant residual was sufficient to estimate the microbial contamination, regardless the physicochemical load. Based on the obtained results, PAA+LA seems to be better suited than chlorine for disinfecting process wash water with a high organic load but a higher disinfectant residual is necessary due to the slower E. coli O157 inactivation kinetics when compared to chlorine. PMID:26065727

  11. Using carbon and water isotopes and noble gases to assess the origin of methane in fresh water aquifers in the south of the Netherlands

    NASA Astrophysics Data System (ADS)

    Broers, Hans Peter; de Weert, Jasperien; Vonhof, Hubert; Janssen, Renee; Sueltenfuss, Juergen; Aeschbach-Hertig, Werner; Castelijns, Jeroen

    2015-04-01

    Groundwater in the Dutch subsurface is known to contain substantial concentrations of methane of which the origin is not always clear. The Dutch subsurface contains relatively high organic matter contents which makes a biogenic origin plausible, however few studies have used water and carbon isotopes to deduce the origin of methane. In relation to possible future exploitation of deep shale gas resources, it is now considered important to assess base line quality of fresh groundwater in overlying aquifers from which drinking water is produced. Therefore, we sampled the raw water of 41 large public supply well fields in the south of the Netherlands which represents a mixture of groundwater of different ages and used the a discrete travel time distribution model (DTTDM, Visser et al. 2013, WRR) in order to quantify the age distribution of the mixture. Measurements included major ion chemistry, 3H, 3He, 4He, 18O, 2H, 14C, 13C-DIC and 13C-CH4 and the full range of noble gases. 13C-CH4 measurements were carried out using a Picarro G2201-i CRDS analyser. The heavier noble gases enable the calculation of the Noble Gas Temperature (NGT) which characterizes the temperature of past recharge conditions. The 14C apparent age of each mixture was derived correcting for dead carbon sources and included carbonate dissolution and methanogenesis as the defining processes. The 13C-CH4 measurements showed a range of δ-values between -70 and -100‰, which give a clear indication for biogenic methane. No clear relations between 13C-CH4 and 13C-DIC or the 4He/CH4 ratio were observed. However, clear spatial patterns indicated that more depleted values are grouped in specific areas. The 13δCH4 values did not show a clear relation with the age distribution of the pumped water, even though a large range of age distributions was observed including old water with an age of > 25 k yrs. We believe that spatial differences in organic matter contents, origin of the geological deposits and/or the

  12. Estimation of the depth to the fresh-water/salt-water interface from vertical head gradients in wells in coastal and island aquifers

    NASA Astrophysics Data System (ADS)

    Izuka, Scot K.; Gingerich, Stephen B.

    An accurate estimate of the depth to the theoretical interface between fresh, water and salt water is critical to estimates of well yields in coastal and island aquifers. The Ghyben-Herzberg relation, which is commonly used to estimate interface depth, can greatly underestimate or overestimate the fresh-water thickness, because it assumes no vertical head gradients and no vertical flow. Estimation of the interface depth needs to consider the vertical head gradients and aquifer anisotropy that may be present. This paper presents a method to calculate vertical head gradients using water-level measurements made during drilling of a partially penetrating well; the gradient is then used to estimate interface depth. Application of the method to a numerically simulated fresh-water/salt-water system shows that the method is most accurate when the gradient is measured in a deeply penetrating well. Even using a shallow well, the method more accurately estimates the interface position than does the Ghyben-Herzberg relation where substantial vertical head gradients exist. Application of the method to field data shows that drilling, collection methods of water-level data, and aquifer inhomogeneities can cause difficulties, but the effects of these difficulties can be minimized. Résumé Une estimation précise de la profondeur de l'interface théorique entre l'eau douce et l'eau salée est un élément critique dans les estimations de rendement des puits dans les aquifères insulaires et littoraux. La relation de Ghyben-Herzberg, qui est habituellement utilisée pour estimer la profondeur de cette interface, peut fortement sous-estimer ou surestimer l'épaisseur de l'eau douce, parce qu'elle suppose l'absence de gradient vertical de charge et d'écoulement vertical. L'estimation de la profondeur de l'interface requiert de prendre en considération les gradients verticaux de charge et l'éventuelle anisotropie de l'aquifère. Cet article propose une méthode de calcul des

  13. Inflow forecasting using Artificial Neural Networks for reservoir operation

    NASA Astrophysics Data System (ADS)

    Chiamsathit, Chuthamat; Adeloye, Adebayo J.; Bankaru-Swamy, Soundharajan

    2016-05-01

    In this study, multi-layer perceptron (MLP) artificial neural networks have been applied to forecast one-month-ahead inflow for the Ubonratana reservoir, Thailand. To assess how well the forecast inflows have performed in the operation of the reservoir, simulations were carried out guided by the systems rule curves. As basis of comparison, four inflow situations were considered: (1) inflow known and assumed to be the historic (Type A); (2) inflow known and assumed to be the forecast (Type F); (3) inflow known and assumed to be the historic mean for month (Type M); and (4) inflow is unknown with release decision only conditioned on the starting reservoir storage (Type N). Reservoir performance was summarised in terms of reliability, resilience, vulnerability and sustainability. It was found that Type F inflow situation produced the best performance while Type N was the worst performing. This clearly demonstrates the importance of good inflow information for effective reservoir operation.

  14. Disentangling the role of atmospheric and oceanic conditions in the occurrence of major Baltic inflows: The importance of haline stratification in the Belt Sea.

    NASA Astrophysics Data System (ADS)

    Höflich, Katharina; Lehmann, Andreas; Myrberg, Kai

    2016-04-01

    The Baltic Sea is a semi-enclosed body of water connected to the North Sea only via the shallow and narrow Danish Straits. Of special importance to the salinity dynamics of the Baltic Sea are so-called major Baltic inflows (highly saline barotropic inflows), that also comprise the only process by which oxygen is supplied to below halocline water masses. Large barotropic inflows (or large volume changes) of the Baltic Sea can be identified from the sea level at Landsort, where the number of large barotropic inflows is found to exceed the number of major Baltic inflows. The occurrence of major Baltic inflows is typically attributed to a sequence of large-scale easterly and westerly atmospheric circulation patterns, that have recently also been linked to the occurrence of large barotropic inflows in general. In this context the widely accepted view that atmospheric conditions (and hence the evolution of the sea level in the North Sea - Baltic Sea system) are of exclusive importance to the occurrence of major Baltic inflows becomes questionable. In this study we attempt to disentangle the role of oceanic and atmospheric conditions to the occurrence of highly saline barotropic inflows, with special focus on the role of the hydrographic conditions in the Belt Sea. For the period 1979 - 2015 and using a realistic three-dimensional numerical ocean model of the Baltic Sea we find that the salinity of the barotropic inflow significantly depends on the availability of saline water masses in the Belt Sea. However, detailed investigation on the time evolution of the single barotropic inflow reveals differences in the rapidness and magnitude of the inflow events. Both are in fact good predictors for the salinity of the inflow, highlighting that within the set of large barotropic inflows also differing atmospheric conditions must play some role in the formation of the salinity of the inflowing water mass. In order to further specify the importance of the hydrographic conditions

  15. Composite desiccant material "CaCl2/Vermiculite/Saw wood": a new material for fresh water production from atmospheric air

    NASA Astrophysics Data System (ADS)

    Kumar, Manoj; Yadav, Avadhesh

    2016-04-01

    In this study a novel composite desiccant material "CaCl2/Vermiculite/Saw wood" have been synthesized and tested for the water generation from atmospheric air. The vermiculite- saw wood used as a host matrix and CaCl2 as a hygroscopic salt. A solar glass desiccant box type system with a collector area of 0.36 m2 has been used. Design parameters for water generation are height of glass from the desiccant material bed as 0.22 m, inclination in angle as 30º, the effective thickness of glass as 3 mm and number of glazing as single. It has been found that the concentration of calcium chloride is the most influencing factor for fresh water generation from atmospheric air. The maximum amount of water produced by using novel composite desiccant material is 195 ml/kg/day.

  16. USEPA RESEARCH ON INFILTRATION/INFLOW CONTROL

    EPA Science Inventory

    From the late 60's to early 80's, the USEPA conducted a series of research, development, and demonsration projects on the characterization, cause and consequence, and control of infiltation/inflow (I/I) in both sanitary and combined sewers. The research effort was driven by the n...

  17. USEPA RESEARCH ON INFILTRATION/INFLOW CONTROL

    EPA Science Inventory

    From the late 60's to early 80's, the USEPA conducted a series of research, development, and demonstration projects on the characterization, cause and consequence, and control of infiltation/inflow (I/I) in both sanitary and combined sewers. The research effort was driven by the ...

  18. The effect of freshwater inflow on meiofaunal consumption of sediment bacteria and microphytobenthos in San Antonio Bay, Texas, U.S.A.

    NASA Astrophysics Data System (ADS)

    Montagna, Paul A.; Yoon, Won Bae

    1991-12-01

    If meiofauna are food-limited then they should respond with increased feeding rates when microbial production is stimulated. River inflow into estuaries is a source of organic matter that can be limiting to bacterial production, and nutrients that might limit primary production. Therefore, inflow should stimulate microbial primary and secondary production, and eventually meiofauna grazing rates should increase as a functional response to increased food availability and quality. To determine if meiofauna grazing rates were affected by inflow, two replicate stations were sampled in the upper, river-dominated end, of San Antonio Bay and contrasted with two replicate stations at the lower end of the estuary. The experiments were performed three times. Water column nutrients and sediment organic matter were higher in the upper end of the estuary than in the lower end. Benthic primary production was 2·5 times higher in the upper end than in the lower end. Benthic metabolism (measured by oxygen consumption) was also higher in the upper end, but bacterial production (measured by thymidine uptake) was not significantly different between the two ends. Grazing rates were 3·5 times higher on bacteria, and 2·5 times higher on microalgae in the upper end of the estuary than in the lower end, confirming our hypothesis that inflow would stimulate grazing rates. Grazing rates were dominated by juvenile molluscs (temporary meiofauna) which accounted for 39% of the microalgae and 68% of the bacteria ingested by the community. Juvenile molluscs were most prevalent in the upper, fresh-water zone. Harpacticoid copepods and nematodes had higher grazing rates in the lower end of the estuary. Grazing rates were higher on microalgae than on bacteria: 4% of the microalgae were removed per hour, compared to only 1% of the bacteria. Grazing rates on microalgae were 2·6 times higher than productivity, indicating meiofauna might be food-limited. Grazing on bacteria was low, and production

  19. Survival and growth of Cronobacter sakazakii on fresh-cut fruit and the effect of UV-C illumination and electrolyzed water in the reduction of its population.

    PubMed

    Santo, David; Graça, Ana; Nunes, Carla; Quintas, Célia

    2016-08-16

    Cronobacter sakazakii, found in foods such as powdered infant formula and plant origin ready-to-eat food, is an opportunistic pathogen to infants, neonates and vulnerable adults. The objective of this study was to monitor the growth of C. sakazakii in fresh-cut 'Royal gala' apple, 'Rocha' pear, and 'Piel de sapo' melon, and the effect of UV-C illumination, acidic electrolyzed water (AEW) and neutral electrolyzed water (NEW) in the reduction of its population. Fresh-cut fruits were inoculated and incubated at different temperatures during 10days while monitoring C. sakazakii. The inhibitory activity of different doses of UV-C (0-10kJ.m(2)), electrolyzed water and sodium hypochlorite (SH) (100ppm chlorine) was evaluated on the fruits inoculated with C. sakazakii. The bacterium showed a significant growth in the fruits at 12 and 20°C, but did not grow at 4°C, despite having survived for 10days. At 8°C, adaptation phases of 0.6-3.9days were estimated in the fruits before exponential growth. The UV-C 7.5 and 10kJ/m(2) produced greater C. sakazakii population decreases (2-2.4logcfu/g) than AEW (1.3-1.8logcfu/g), NEW (1-1.2logcfu/g) and SH (0.8-1.4logcfu/g). The UV-C decontamination system and refrigeration at 4°C, may contribute to the product's safety and quality. The results help better understand the behavior of C. sakazakii on fresh-cut fruit alerting producers of the necessity to respect the high hygienic practices, adequate refrigerating temperature maintenance and caution with the tendency to prolong the validity of this kind of ready-to-eat food. PMID:27163653

  20. Thermosensitive ion channel TRPV1 is endogenously expressed in the sperm of a fresh water teleost fish (Labeo rohita) and regulates sperm motility

    PubMed Central

    Majhi, Rakesh Kumar; Kumar, Ashutosh; Yadav, Manoj; Swain, Nirlipta; Kumari, Shikha; Saha, Ashish; Pradhan, Avinash; Goswami, Luna; Saha, Somdatta; Samanta, Luna; Maity, Apratim; Nayak, Tapas Kumar; Chattopadhyay, Subhasis; Rajakuberan, Chitra; Kumar, Abhishek; Goswami, Chandan

    2013-01-01

    Sperm cells exhibit extremely high sensitivity in response to slight changes in temperature, osmotic pressure and/or presence of various chemical stimuli. In most cases throughout the evolution, these physico-chemical stimuli trigger Ca2+-signaling and subsequently alter structure, cellular function, motility and survival of the sperm cells. Few reports have recently demonstrated the presence of Transient Receptor Potential (TRP) channels in the sperm cells from higher eukaryotes, mainly from higher mammals. In this work, we have explored if the sperm cells from lower vertebrates can also have thermo-sensitive TRP channels. In this paper, we demonstrate the endogenous presence of one specific thermo-sensitive ion channel, namely Transient Receptor Potential Vanilloid family member sub type 1 (TRPV1) in the sperm cells collected from fresh water teleost fish, Labeo rohita. By using western blot analysis, fluorescence assisted cell sorting (FACS) and confocal microscopy; we confirm the presence of this non-selective cation channel. Activation of TRPV1 by an endogenous activator NADA significantly increases the quality as well as the duration of fish sperm movement. The sperm cell specific expression of TRPV1 matches well with our in silico sequence analysis. The results demonstrate that TRPV1 gene is conserved in various fishes, ranging from 1–3 in copy number, and it originated by fish-specific duplication events within the last 320 million years (MY). To the best of our knowledge, this is the first report demonstrating the presence of any thermo-sensitive TRP channels in the sperm cells of early vertebrates as well as of aquatic animals, which undergo external fertilization in fresh water. This observation may have implications in the aquaculture, breeding of several fresh water and marine fish species and cryopreservation of fish sperms. PMID:23912940

  1. Estimates of average annual tributary inflow to the lower Colorado River, Hoover Dam to Mexico

    USGS Publications Warehouse

    Owen-Joyce, Sandra J.

    1987-01-01

    Estimates of tributary inflow by basin or area and by surface water or groundwater are presented in this report and itemized by subreaches in tabular form. Total estimated average annual tributary inflow to the Colorado River between Hoover Dam and Mexico, excluding the measured tributaries, is 96,000 acre-ft or about 1% of the 7.5 million acre-ft/yr of Colorado River water apportioned to the States in the lower Colorado River basin. About 62% of the tributary inflow originates in Arizona, 30% in California, and 8% in Nevada. Tributary inflow is a small component in the water budget for the river. Most of the quantities of unmeasured tributary inflow were estimated in previous studies and were based on mean annual precipitation for 1931-60. Because mean annual precipitation for 1951-80 did not differ significantly from that of 1931-60, these tributary inflow estimates are assumed to be valid for use in 1984. Measured average annual runoff per unit drainage area on the Bill Williams River has remained the same. Surface water inflow from unmeasured tributaries is infrequent and is not captured in surface reservoirs in any of the States; it flows to the Colorado River gaging stations. Estimates of groundwater inflow to the Colorad River valley. Average annual runoff can be used in a water budget; although in wet years, runoff may be large enough to affect the calculation of consumptive use and to be estimated from hydrographs for the Colorado River valley are based on groundwater recharge estimates in the bordering areas, which have not significantly changed through time. In most areas adjacent to the Colorado River valley, groundwater pumpage is small and pumping has not significantly affected the quantity of groundwater discharged to the Colorado River valley. In some areas where groundwater pumpage exceeds the quantity of groundwater discharge and water levels have declined, the quantity of discharge probably has decreased and groundwater inflow to the Colorado

  2. Reservoir operation with combined natural inflow and controlled inflow through inter-basin transfer - A case study of Biliu Reservoir in northeastern China

    NASA Astrophysics Data System (ADS)

    Li, Y.; Zhang, C.; Chu, J.; Cai, X.; Zhou, H.

    2015-12-01

    The essential problem for reservoir operation is how to deal with the variability of inflow. The impacts of both climate change and human interferences on streamflow further complicate the issue of reservoir inflow variability. This paper presents a case study of a reservoir that has both natural inflow (NI) and controlled inflow (CI), and analyzes how CI, which can be a deterministic item, mitigates the effect of NI variability on reservoir operation. Through a case study of the Biliu River Reservoir in northeastern China, we address the following questions: a) how will the combined NI and CI improve water supply reliability, and b) whether and how much of the reservoir storage can be reduced without lowering water supply reliability with a certain level of CI? It is found that CI complements to NI in terms of water supply reliability through a nonlinear relationship, as shown by an inverse "S" curve; the two "turning points" in the curve specify a range of CI with respect to the stochastic nature of NI and the reservoir operation objectives. For the case study reservoir, if the amount of annual CI increases to about 54% of the NI, the primary reservoir storage capacity can be reduced by 40% while providing the same level of water supply reliability.

  3. Molecular cloning of fresh water and deep-sea rod opsin genes from Japanese eel Anguilla japonica and expressional analyses during sexual maturation.

    PubMed

    Zhang, H; Futami, K; Horie, N; Okamura, A; Utoh, T; Mikawa, N; Yamada, Y; Tanaka, S; Okamoto, N

    2000-03-01

    We have determined the complete cDNA sequences of fresh water rod opsin gene (fwo) and deep-sea rod opsin gene (dso) from Japanese eel Anguilla japonica. The cDNA clones of fwo and dso consisted of 1437 and 1497 nucleotides, respectively. The predicted opsins of both genes consisted of 352 amino acid residues. Southern blot and PCR analyses of genomic DNA indicated that the Japanese eel genome contains only one fwo and one dso and they are intronless. Quantitative RT-PCR analyses revealed that the expression of fwo decreases with sexual maturation while that of dso increases.

  4. Swimming-associated haemorrhagic colitis due to Escherichia coli O157:H7 infection: evidence of prolonged contamination of a fresh water lake.

    PubMed Central

    Ackman, D.; Marks, S.; Mack, P.; Caldwell, M.; Root, T.; Birkhead, G.

    1997-01-01

    We describe an Escherichia coli O157:H7 outbreak associated with a fresh water lake at a county park. Campers were surveyed for diarrhoeal illness within 10 days of their visit, and a case-control study of day visitors was conducted. A confirmed case was a symptomatic person with a stool culture positive for E. coli O157:H7 and a probable case was a person with bloody diarrhoea. Clinical isolates of E. coli O157 were subtyped by pulsed field gel electrophoresis (PFGE). In the camper survey, 12 (38%) of 32 swimmers had a diarrhoeal illness (relative risk [RR] = 12.4; 95% confidence interval [CI] = 1.7-89.7). For the case-control study, the 12 cases were more likely than controls to have purposefully ingested lake water (odds ratio [OR] = 6.9, 95% CI = 0.9-55.8). The PFGE patterns of six clinical isolates were indistinguishable. This report further demonstrates that contaminated fresh-water lakes can be the source of community outbreaks of E. coli O157:H7. PMID:9287936

  5. A systematic review and meta-analysis of the effects of extreme weather events and other weather-related variables on Cryptosporidium and Giardia in fresh surface waters.

    PubMed

    Young, Ian; Smith, Ben A; Fazil, Aamir

    2015-03-01

    Global climate change is expected to impact drinking water quality through multiple weather-related phenomena. We conducted a systematic review and meta-analysis of the relationship between various weather-related variables and the occurrence and concentration of Cryptosporidium and Giardia in fresh surface waters. We implemented a comprehensive search in four databases, screened 1,228 unique citations for relevance, extracted data from 107 relevant articles, and conducted random-effects meta-analysis on 16 key relationships. The average odds of identifying Cryptosporidium oocysts and Giardia cysts in fresh surface waters was 2.61 (95% CI = 1.63-4.21; I² = 16%) and 2.87 (95% CI = 1.76-4.67; I² = 0%) times higher, respectively, during and after extreme weather events compared to baseline conditions. Similarly, the average concentration of Cryptosporidium and Giardia identified under these conditions was also higher, by approximately 4.38 oocysts/100 L (95% CI = 2.01-9.54; I(2) = 0%) and 2.68 cysts/100 L (95% CI = 1.08-6.55; I² = 48%). Correlation relationships between other weather-related parameters and the density of these pathogens were frequently heterogeneous and indicated low to moderate effects. Meta-regression analyses identified different study-level factors that influenced the variability in these relationships. The results can be used as direct inputs for quantitative microbial risk assessment. Future research is warranted to investigate these effects and potential mitigation strategies in different settings and contexts.

  6. On the warm inflow at the eastern boundary of the Weddell Gyre

    NASA Astrophysics Data System (ADS)

    Ryan, S.; Schröder, M.; Huhn, O.; Timmermann, R.

    2016-01-01

    The Weddell Sea plays an important role for the global oceans and climate by being one of the biggest production and export areas of Antarctic Bottom Water (AABW). Circumpolar Deep Water (CDW) enters the Weddell Gyre (WG) at its eastern boundary. Then called Warm Deep Water (WDW), it is a major contributor to the formation of deep and bottom waters due to ocean-ice shelf interactions in the southern and soutwestern Weddell Sea. Hydrographic data collected between 0 and 30°E on the RV Polarstern cruise ANT XX/2 reveals a two-core structure for the eastern inflow of warm water at roughly 20°E but not further downstream at the Greenwich meridian (GM). Model results and climatological fields suggest that the two cores represent two separate modes of warm inflow. One mode is driven by eddy mixing in the northeastern corner of the WG and the other one is an advective mode, forming the southern branch of the inflow which extends beyond 30°E before turning westward. Both pathways are likely to carry waters from different origins within the Antarctic Circumpolar Current ACC, where more ventilated CDW is found at the Southern Boundary SB compared to the centre. The southern route shows considerable interannual variability in the model. A variable inflow of two types of CDW together with admixed recirculated and cooler waters from the Weddell Sea can potentially contribute to the observed variability and warming trend of WDW over the last decade at the GM.

  7. Implications of Colorado river (Texas, USA) freshwater inflow to benthic ecosystem dynamics: A modeling study

    NASA Astrophysics Data System (ADS)

    Kim, Hae-Cheol; Montagna, Paul A.

    2009-08-01

    Estuaries are defined by mixing of freshwater from rivers and saltwater from seas. Water resource development can reduce river flows to the coast, but it is difficult to predict effects on estuaries. The Lavaca-Colorado Estuary is a major estuarine system along the Texas coast that provides major economic benefit to the region by supporting a variety of agricultural, residential, industrial, and recreational functions. New water projects could divert freshwater from Matagorda Bay. So, what environmental effects could result from further changes to inflow patterns in the Matagorda Bay system? To answer this question, a bioenergetic model, calibrated using a long-term dataset of benthic biomass, was run to investigate dynamics of macrobenthic biomass related to salinity regimes in the estuary. The model simulation results were interpreted to assess the role of freshwater inflow in controlling benthic productivity. Simulations, based on calibrated parameters (1988-1999), were run for a long-term period from 1988 to 2005. The model performance was found to be promising with the best percent root mean square (RMS) difference being 63% and worst being 92%. Sensitivity tests for the benthic responses to changes in salinity show that, in general, wh