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Sample records for sands process-affected water

  1. Oil sand process-affected water treatment using coke adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Gamal El-Din, M.; Pourrezaei, P.; Chelme-Ayala, P.; Zubot, W. [Alberta Univ., Edmonton, AB (Canada). Dept. of Civil and Environmental Engineering

    2010-07-01

    Oil sands operations generate an array of oil sands process-affected water (OSPW) that will eventually be released to the environment. This water must be evaluated within conventional and advanced water treatment technologies. Water management strategies propose options for increased reuse and recycling of water from settling ponds, as well as safe discharge. This presentation outlined the typical composition of OSPW. Constituents of concern in OSPW include suspended solids, hydrocarbons, salts, ammonia, trace metals, and dissolved organics such as naphthenic acids (NAs). Petroleum coke is one of the by-products generated from bitumen extraction in the oil sands industry and can be used as one of the possible treatment processes for the removal of organic compounds found in OSPW. Activated carbon adsorption is an effective process, able to adsorb organic substances such as oils, radioactive compounds, petroleum hydrocarbons, poly aromatic hydrocarbons and various halogenated compounds. The objectives of this study were to evaluate the production of activated carbon from petroleum coke using steam as the activation media; to determine the factors affecting the absorption of NAs; and to evaluate the activated coke adsorption capacity for the reduction of NAs and dissolved organic carbons present in OSPW. It was concluded that petroleum non-activated coke has the ability to decrease COD, alkalinity, and NA concentration. tabs., figs.

  2. Coagulation-flocculation pretreatment of oil sands process affected water

    Energy Technology Data Exchange (ETDEWEB)

    Pourrezaei, P.; El-Din, M.G. [Alberta Univ., Edmonton, AB (Canada). Dept. of Civil and Environmental Engineering

    2008-07-01

    This presentation addressed the issue of water use in the oil sands industry and efforts to use this limited resource more efficiently. Three wastewater treatment schemes for oil sands tailings ponds were proposed, notably primary, secondary and tertiary treatment. Primary treatment involves the removal of suspended solids using physical-chemical treatments. Secondary treatment involves the removal of dissolved solids and organics using chemical oxidation, ultrafiltration or nanofiltration. Tertiary treatment involves removal of residual organics/solids using biological activated carbon filtration, sand filtration or reverse osmosis. The composition of oil sands process water (OSPW) was also discussed with reference to suspended solids, salts, hydrocarbons, other dissolved organics (such as naphthenic acids and phenols), ammonia, inorganic compounds and trace elements. The conventional coagulation/flocculation process is essential in industrial wastewater treatment. It is cost effective, easy to operate and energy efficient. The process is used because small suspended and colloidal particles and dissolved constituents cannot be removed quickly by sedimentation. A chemical method must be used. Coagulation/flocculation brings small suspended and colloidal particles into contact so that they collide, stick and grow to a size that settles readily. Alum is the predominant and least expensive water treatment coagulant used for the coagulation/flocculation process. It provides positively charged ions to neutralize the negative charge of colloidal particles resulting in aggregation. It creates big settling flocs that enmesh colloids as it settles. The factors affecting the process include pH, chemical type, chemical concentration, rapid mixing intensity, slow mixing intensity and time. tabs., figs.

  3. Characterization of napthenic acids in oil sands process-affected waters using fluorescence technology

    Energy Technology Data Exchange (ETDEWEB)

    Brown, L.; Alostaz, M.; Ulrich, A. [Alberta Univ., Edmonton, AB (Canada). Dept. of Civil and Environmental Engineering

    2009-07-01

    Process-affected water from oil sands production plants presents a major environmental challenge to oil sands operators due to its toxicity to different organisms as well as its corrosiveness in refinery units. This abstract investigated the use of fluorescence excitation-emission matrices to detect and characterize changes in naphthenic acid in oil sands process-affected waters. Samples from oil sands production plants and storage ponds were tested. The study showed that oil sands naphthenic acids show characteristic fluorescence signatures when excited by ultraviolet light in the range of 260 to 350 mm. The signal was a unique attribute of the naphthenic acid molecule. Changes in the fluorescence signature can be used to determine chemical changes such as degradation or aging. It was concluded that the technology can be used as a non-invasive continuous water quality monitoring tool to increase process control in oil sands processing plants.

  4. Petroleum coke adsorption as a water management option for oil sands process-affected water

    Energy Technology Data Exchange (ETDEWEB)

    Zubot, Warren [Syncrude Canada Ltd., Research and Development, Edmonton, Alberta, Canada T6N 1H4 (Canada); MacKinnon, Michael D. [OSPM Solutions Ltd., Hamilton, Ontario, Canada L8H 6X2 (Canada); Chelme-Ayala, Pamela; Smith, Daniel W. [University of Alberta, Department of Civil and Environmental Engineering, Edmonton, Alberta, Canada T6G 2W2 (Canada); Gamal El-Din, Mohamed, E-mail: mgamalel-din@ualberta.ca [University of Alberta, Department of Civil and Environmental Engineering, Edmonton, Alberta, Canada T6G 2W2 (Canada)

    2012-06-15

    Water is integral to both operational and environmental aspects of the oil sands industry. A water treatment option based on the use of petroleum coke (PC), a by-product of bitumen upgrading, was examined as an opportunity to reduce site oil sands process-affected water (OSPW) inventories and net raw water demand. Changes in OSPW quality when treated with PC included increments in pH levels and concentrations of vanadium, molybdenum, and sulphate. Constituents that decreased in concentration after PC adsorption included total acid-extractable organics (TAO), bicarbonate, calcium, barium, magnesium, and strontium. Changes in naphthenic acids (NAs) speciation were observed after PC adsorption. A battery of bioassays was used to measure the OSPW toxicity. The results indicated that untreated OSPW was toxic towards Vibrio fischeri and rainbow trout. However, OSPW treated with PC at appropriate dosages was not acutely toxic towards these test organisms. Removal of TAO was found to be an adsorption process, fitting the Langmuir and Langmuir-Freundlich isotherm models. For TAO concentrations of 60 mg/L, adsorption capacities ranged between 0.1 and 0.46 mg/g. This study demonstrates that freshly produced PC from fluid cokers provides an effective treatment of OSPW in terms of key constituents' removal and toxicity reduction. - Highlights: Black-Right-Pointing-Pointer Treatment of oil sands process-affected water (OSPW) using petroleum coke (PC) adsorption was investigated. Black-Right-Pointing-Pointer PC was effective at adsorbing naphthenic acids with higher cyclicity. Black-Right-Pointing-Pointer OSPW treated with PC at appropriate dosages was not toxic towards Vibrio fisheri and rainbow trout. Black-Right-Pointing-Pointer The adsorption of organic acids fitted the Langmuir and Langmuir-Freundlich isotherm models. Black-Right-Pointing-Pointer PC has the potential to be an effective adsorbent to treat OSPW either directly or as a pretreatment step.

  5. Characterization of oil sands process-affected waters by liquid chromatography orbitrap mass spectrometry.

    Science.gov (United States)

    Pereira, Alberto S; Bhattacharjee, Subir; Martin, Jonathan W

    2013-05-21

    Recovery of bitumen from oil sands in northern Alberta, Canada, occurs by surface mining or in situ thermal recovery, and both methods produce toxic oil sands process-affected water (OSPW). A new characterization strategy for surface mining OSPW (sm-OSPW) and in situ OSPW (is-OSPW) was achieved by combining liquid chromatography with orbitrap mass spectrometry (MS). In electrospray positive and negative ionization modes (ESI(+)/ESI(-)), mass spectral data were acquired with high resolving power (RP > 100,000-190,000) and mass accuracy (method should be further applied to environmental forensic analysis of water in the region.

  6. The growth and photosynthesis of Typha in oil sands process affected material and water

    Energy Technology Data Exchange (ETDEWEB)

    Foote, L. [Alberta Univ., Edmonton, AB (Canada); Hornung, J. [Petro-Canada, Calgary, AB (Canada)

    2007-07-01

    Aquatic plants such as cattail contribute substantially to the energy flow in wetlands. Since Typha (cattail) plants acquire and cycle carbon and nutrients through wetlands, their growth and recycling of captured nutrients are an important part of natural, healthy wetland ecosystems. Cattail are pervasive and satisfy many of the criteria to be used as indicators of wetland integrity. This study investigated if cattail growth and carbon accrual were influenced by oil sands process materials (OSPM) such as consolidated tailings (CT). The purpose was to facilitate land reclamation initiatives by evaluating the impact that constituents of oil sands process material have on aquatic plant growth. The study was conducted at Suncor's experimental trenches. Six lined basins were used, of which 3 were filled with natural water and 3 were filled with trench water. Cattail were planted in different growth medium combinations, including CT over CT; soil over soil; soil over CT; and soil over sterilized sand. All leaf lengths and widths were measured along with the photosynthesis of the leaves and root and plant biomass at planting and after 2-years growth. A larger leaf area was observed under oil sands process influence, which may indicate increased carbon accrual above ground. Leaf area data suggested that CT affected plants are quite productive. The study also indicated that oil sands affected water may reduce plant fitness, and therefore could influence the overall oil sands reclamation timelines. Conversely, cattail grown in soil capped process affected material had a much larger leaf area compared to those grown in soil capped sand, most likely due to the higher levels of ammonia in process affected material.

  7. Detecting oil sands process-affected waters in the Alberta oil sands region using synchronous fluorescence spectroscopy.

    Science.gov (United States)

    Kavanagh, Richard J; Burnison, B Kent; Frank, Richard A; Solomon, Keith R; Van Der Kraak, Glen

    2009-06-01

    Large volumes of oil sands process-affected waters (OSPW) are produced during the extraction of bitumen from oil sand. There are approximately 10(9) m(3) of OSPW currently being stored in settling basins on oil sands mining sites in Northern Alberta. Developers plan to create artificial lakes with OSPW and it is expected that this water may eventually enter the environment. This study was conducted in order to determine if synchronous fluorescence spectroscopy (SFS) could detect OSPW contamination in water systems. Water samples collected from ponds containing OSPW and selected sites in the Alberta oil sands region were evaluated using SFS with an offset value of 18 nm. OSPW ponds consistently displayed a minor peak at 282.5 nm and a broad major peak ranging between 320 and 340 nm. Water from reference sites within the oil sands region had little fluorescence at 282.5 nm but greater fluorescence beyond 345 nm. Naphthenic acids are the major toxic component of OSPW. Both a commercial naphthenic acid and a naphthenic acid extract prepared from OSPW had similar fluorescent spectra with peaks at 280 nm and 320 nm and minor shoulders at approximately 303 and 331 nm. The presence of aromatic acids closely associated with the naphthenic acids may be responsible for unique fluorescence at 320-340 nm. SFS is proposed to be a simple and fast method to monitor the release of OSPW into ground and surface waters in the oil sands region.

  8. Application of forward osmosis membrane technology for oil sands process-affected water desalination.

    Science.gov (United States)

    Jiang, Yaxin; Liang, Jiaming; Liu, Yang

    2016-01-01

    The extraction process used to obtain bitumen from the oil sands produces large volumes of oil sands process-affected water (OSPW). As a newly emerging desalination technology, forward osmosis (FO) has shown great promise in saving electrical power requirements, increasing water recovery, and minimizing brine discharge. With the support of this funding, a FO system was constructed using a cellulose triacetate FO membrane to test the feasibility of OSPW desalination and contaminant removal. The FO systems were optimized using different types and concentrations of draw solution. The FO system using 4 M NH4HCO3 as a draw solution achieved 85% water recovery from OSPW, and 80 to 100% contaminant rejection for most metals and ions. A water backwash cleaning method was applied to clean the fouled membrane, and the cleaned membrane achieved 77% water recovery, a performance comparable to that of new FO membranes. This suggests that the membrane fouling was reversible. The FO system developed in this project provides a novel and energy efficient strategy to remediate the tailings waters generated by oil sands bitumen extraction and processing.

  9. Oil sands process-affected water impairs feeding by Daphnia magna.

    Science.gov (United States)

    Lari, Ebrahim; Steinkey, Dylan; Morandi, Garrett; Rasmussen, Joseph B; Giesy, John P; Pyle, Greg G

    2017-05-01

    Growth in extraction of bitumen from oil sands has raised concerns about influences of this industry on surrounding environments. Water clearance rate (a surrogate of feeding rate by Daphnia magna) in water containing D. magna exposed to oil sands process-affected water (OSPW) and its principal components, dissolved component (DC) and suspended particulate matter (SPM), was reduced to 72, 29, and 59% of controls, respectively. This study also examined several possible mechanisms for the observed changes algal cell density (i.e., feeding rate). There was no change in the digestive enzymes trypsin or amylase when D. magna were exposed to DC or SPM; however, exposure to total OSPW reduced trypsin activity. Mandible rolling or post-abdominal rejections, which are indicators of feeding and palatability of food, were not affected by any exposures to OSPW. Beating of thoracic limbs, which provides water flow toward the feeding groove, was reduced by exposure to SPM or total OSPW. Peristaltic activity was reduced by exposure to DC, which then might result in reduced digestion time in D. magna exposed to DC, SPM or whole OSPW. All treatments caused an increase in numbers of intact algae cells in the hindgut and excreted material. These results suggest that both DC and SPM affect feeding of D. magna by impairing actions of the digestive system, but most probably not by reducing rates of ingestion.

  10. Sulfate reducing bacteria and their activities in oil sands process-affected water biofilm

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hong; Yu, Tong, E-mail: tong.yu@ualberta.ca; Liu, Yang, E-mail: yang.liu@ualberta.ca

    2015-12-01

    Biofilm reactors were constructed to grow stratified multispecies biofilm in oil sands process-affected water (OSPW) supplemented with growth medium. The development of sulfate reducing bacteria (SRB) within the biofilm and the biofilm treatment of OSPW were evaluated. The community structure and potential activity of SRB in the biofilm were investigated with H{sub 2}S microsensor measurements, dsrB gene-based denaturing gradient gel electrophoresis (DGGE), and the real time quantitative polymerase chain reaction (qPCR). Multispecies biofilm with a thickness of 1000 μm was successfully developed on engineered biocarriers. H{sub 2}S production was observed in the deeper anoxic zone of the biofilm from around 750 μm to 1000 μm below the bulk water-biofilm interface, revealing sulfate reduction in the deeper zone of the stratified biofilm. The biofilm removed chemical oxygen demand (COD), sulfate, and nitrogen. The study expands current knowledge of biofilm treatment of OSPW and the function of anaerobic SRB in OSPW biofilm, and thus provides information for future bioreactor development in the reclamation of OSPW. - Graphical abstract: The development of sulfate reducing bacteria (SRB) within Oil Sands Process-affected Water (OSPW) biofilm and the biofilm treatment of OSPW were evaluated by Liu and coworkers. Combined microsensor and molecular biology techniques were utilized in this study. Their results demonstrated that multispecies biofilm with a thickness of 1000 μm was successfully developed on engineered biocarriers. H{sub 2}S production was observed in the deeper anoxic zone of the biofilm from around 750 μm to 1000 μm below the bulk water-biofilm interface, revealing sulfate reduction in the deeper zone of the biofilm. The biofilm removed chemical oxygen demand (COD), sulfate, and nitrogen. - Highlights: • Biofilm in oil sands wastewater was developed on engineered biocarriers. • Bacterial community and in situ activity of SRB were studied in the

  11. Fathead minnow (Pimephales promelas) reproduction is impaired in aged oil sands process-affected waters.

    Science.gov (United States)

    Kavanagh, Richard J; Frank, Richard A; Oakes, Ken D; Servos, Mark R; Young, Rozlyn F; Fedorak, Phillip M; MacKinnon, Mike D; Solomon, Keith R; Dixon, D George; Van Der Kraak, Glen

    2011-01-17

    Large volumes of fluid tailings are generated during the extraction of bitumen from oil sands. As part of their reclamation plan, oil sands operators in Alberta propose to transfer these fluid tailings to end pit lakes and, over time, these are expected to develop lake habitats with productive capabilities comparable to natural lakes in the region. This study evaluates the potential impact of various oil sands process-affected waters (OSPW) on the reproduction of adult fathead minnow (Pimephales promelas) under laboratory conditions. Two separate assays with aged OPSW (>15 years) from the experimental ponds at Syncrude Canada Ltd. showed that water containing high concentrations of naphthenic acids (NAs; >25 mg/l) and elevated conductivity (>2000 μS/cm) completely inhibited spawning of fathead minnows and reduced male secondary sexual characteristics. Measurement of plasma sex steroid levels showed that male fathead minnows had lower concentrations of testosterone and 11-ketotestosterone whereas females had lower concentrations of 17β-estradiol. In a third assay, fathead minnows were first acclimated to the higher salinity conditions typical of OSPW for several weeks and then exposed to aged OSPW from Suncor Energy Inc. (NAs ∼40 mg/l and conductivity ∼2000 μS/cm). Spawning was significantly reduced in fathead minnows held in this effluent and male fathead minnows had lower concentrations of testosterone and 11-ketotestosterone. Collectively, these studies demonstrate that aged OSPW has the potential to negatively affect the reproductive physiology of fathead minnows and suggest that aquatic habitats with high NAs concentrations (>25 mg/l) and conductivities (>2000 μS/cm) would not be conducive for successful fish reproduction.

  12. Solar photocatalytic degradation of naphthenic acids in oil sands process-affected water.

    Science.gov (United States)

    Leshuk, Tim; Wong, Timothy; Linley, Stuart; Peru, Kerry M; Headley, John V; Gu, Frank

    2016-02-01

    Bitumen mining in the Canadian oil sands creates large volumes of oil sands process-affected water (OSPW), the toxicity of which is due in part to naphthenic acids (NAs) and other acid extractable organics (AEO). The objective of this work was to evaluate the potential of solar photocatalysis over TiO2 to remove AEO from OSPW. One day of photocatalytic treatment under natural sunlight (25 MJ/m(2) over ∼14 h daylight) eradicated AEO from raw OSPW, and acute toxicity of the OSPW toward Vibrio fischeri was eliminated. Nearly complete mineralization of organic carbon was achieved within 1-7 day equivalents of sunlight exposure, and degradation was shown to proceed through a superoxide-mediated oxidation pathway. High resolution mass spectrometry (HRMS) analysis of oxidized intermediate compounds indicated preferential degradation of the heavier and more cyclic NAs (higher number of double bond equivalents), which are the most environmentally persistent fractions. The photocatalyst was shown to be recyclable for multiple uses, and thus solar photocatalysis may be a promising "green" advanced oxidation process (AOP) for OSPW treatment.

  13. Screening of genotoxicity and mutagenicity in extractable organics from oil sands process-affected water.

    Science.gov (United States)

    Zetouni, Nikolas C; Siraki, Arno G; Weinfeld, Michael; Pereira, Alberto Dos Santos; Martin, Jonathan W

    2016-11-01

    Large volumes of oil sands process-affected water (OSPW) are produced by the oil sands surface mining industry during alkaline hot-water extraction of bitumen. It is well documented that the acid extractable organics (AEOs) in OSPW, a highly complex mixture of acidic and polar neutral substances, are acutely toxic; but few studies have examined the genotoxicity or mutagenicity of this mixture. In the present study, the in vitro SOS Chromotest and the Ames test (TA98 and TA100 strains) were used to evaluate genotoxicity and mutagenicity for whole OSPW AEOs in the presence and absence of biotransformation by rat S9 liver enzymes. Two subfractions were also examined in the same assays: neutral extractable fraction (F1-NE), and the subsequent acid extractable fraction (F2-AE). In the SOS assay, whole AEO was cytotoxic when concentrated 2× (i.e., twice as concentrated as the environmental sample) and showed increasing genotoxic response above 6×. Co-exposure with S9 had a protective effect on the cell SOS-inducing factor and survival but did not eliminate genotoxicity above 6× concentrations. Most of the cytotoxicity was attributable to F2-AE, but both F1-NE and F2-AE had similar genotoxic dose-responses above 6×. In the Ames test without S9, whole AEO was mutagenic in both strains above 10× concentrations. Co-incubation with S9 had little effect on the TA100 strain but with TA98 resulted in bioactivation at midlevel doses (1.5-6.3×) and protection at higher doses (10-25×). The 2 subfractions were mutagenic in both strains but with different dose-responses. Further research in vivo or in more relevant cells is warranted to investigate the carcinogenic risks of OSPW. Environ Toxicol Chem 2016;9999:1-8. © 2016 SETAC.

  14. Sulfate reducing bacteria and their activities in oil sands process-affected water biofilm.

    Science.gov (United States)

    Liu, Hong; Yu, Tong; Liu, Yang

    2015-12-01

    Biofilm reactors were constructed to grow stratified multispecies biofilm in oil sands process-affected water (OSPW) supplemented with growth medium. The development of sulfate reducing bacteria (SRB) within the biofilm and the biofilm treatment of OSPW were evaluated. The community structure and potential activity of SRB in the biofilm were investigated with H2S microsensor measurements, dsrB gene-based denaturing gradient gel electrophoresis (DGGE), and the real time quantitative polymerase chain reaction (qPCR). Multispecies biofilm with a thickness of 1000 μm was successfully developed on engineered biocarriers. H2S production was observed in the deeper anoxic zone of the biofilm from around 750 μm to 1000 μm below the bulk water-biofilm interface, revealing sulfate reduction in the deeper zone of the stratified biofilm. The biofilm removed chemical oxygen demand (COD), sulfate, and nitrogen. The study expands current knowledge of biofilm treatment of OSPW and the function of anaerobic SRB in OSPW biofilm, and thus provides information for future bioreactor development in the reclamation of OSPW.

  15. Pseudomonads biodegradation of aromatic compounds in oil sands process-affected water.

    Science.gov (United States)

    Zhang, Yanyan; McPhedran, Kerry N; Gamal El-Din, Mohamed

    2015-07-15

    Aromatic naphthenic acids (NAs) have been shown to be more toxic than the classical NAs found in oil sands process-affected water (OSPW). To reduce this toxicity, Pseudomonas fluorescens and Pseudomonas putida were used to determine their ability to biodegrade aromatic compounds including treatments considering the impacts of external carbon and iron addition. Results showed that with added carbon P. fluorescens and P. putida have the capability of biodegrading these aromatics. In the presence of external carbon, gene expression of a functional PAH-ring hydroxylating dioxygenase (PAH-RHDα) was determined through reverse transcription real-time PCR, suggesting active degradation of OSPW aromatic compounds. Although no significant classical NAs removal was observed during this process, toxicity was reduced by 49.3% under optimal conditions. OSPW toxicity was eliminated with the combination of ozonation at a dose of 80 mg/L followed by biodegradation, indicating that it is a promising combined OSPW treatment approach for the safe discharge to the aquatic environment.

  16. Ozonation of oil sands process-affected water accelerates microbial bioremediation.

    Science.gov (United States)

    Martin, Jonathan W; Barri, Thaer; Han, Xiumei; Fedorak, Phillip M; El-Din, Mohamed Gamal; Perez, Leonidas; Scott, Angela C; Jiang, Jason Tiange

    2010-11-01

    Ozonation can degrade toxic naphthenic acids (NAs) in oil sands process-affected water (OSPW), but even after extensive treatment a residual NA fraction remains. Here we hypothesized that mild ozonation would selectively oxidize the most biopersistent NA fraction, thereby accelerating subsequent NA biodegradation and toxicity removal by indigenous microbes. OSPW was ozonated to achieve approximately 50% and 75% NA degradation, and the major ozonation byproducts included oxidized NAs (i.e., hydroxy- or keto-NAs). However, oxidized NAs are already present in untreated OSPW and were shown to be formed during the microbial biodegradation of NAs. Ozonation alone did not affect OSPW toxicity, based on Microtox; however, there was a significant acceleration of toxicity removal in ozonated OSPW following inoculation with native microbes. Furthermore, all residual NAs biodegraded significantly faster in ozonated OSPW. The opposite trend was found for ozonated commercial NAs, which are known to contain no significant biopersistent fraction. Thus, we suggest that ozonation preferentially degraded the most biopersistent OSPW NA fraction, and that ozonation is complementary to the biodegradation capacity of microbial populations in OSPW. The toxicity of ozonated OSPW to higher organisms needs to be assessed, but there is promise that this technique could be applied to accelerate the bioremediation of large volumes of OSPW in Northern Alberta, Canada.

  17. Reproductive and stress hormone levels in goldfish (Carassius auratus) exposed to oil sands process-affected water.

    Science.gov (United States)

    Lister, A; Nero, V; Farwell, A; Dixon, D G; Van Der Kraak, G

    2008-05-01

    Athabasca oil sands mining in northern Alberta produces process-affected waters that are characterized by the presence of naphthenic acids, polycyclic aromatic hydrocarbons, and high salinity. The purpose of this study was to examine the impact of these process-affected waters on reproductive and stress related endpoints in mature goldfish, Carassius auratus. In two separate studies, testosterone and 17beta-estradiol levels in the plasma were significantly reduced in both male and female goldfish caged for 19 days in process-affected waters relative to controls. This effect was most pronounced in goldfish caged at a site containing mature fine tailing and tailings pond water (P5). Ovarian and testicular tissues from fish in the caging studies were incubated in vitro to evaluate potential differences in basal steroid production levels and responsiveness to human chorionic gonadotropin (hCG). Basal levels of testosterone were reduced significantly in males and females from P5 compared with the control pond (P1) demonstrating that the gonads from exposed fish had a diminished steroidogenic capacity. Gonadal tissues of fish from all ponds responded similarly to hCG suggesting that the steroid biosynthetic pathway remained functionally intact. Plasma cortisol levels were significantly higher in male goldfish caged in a pond containing mature fine tailings and capped with uncontaminated water (P3) and in P5 compared with P1. Collectively, these studies suggest that waste products of oil sands mining have the potential to disrupt the normal endocrine functioning in exposed fish through alterations to both reproductive and glucocorticoid hormone biosynthesis. In additional laboratory studies, exposure of goldfish to a naphthenic acid extract for 7 days failed to replicate the effects of processes-affected waters on plasma steroid levels and the causative agent(s) responsible for the effects on steroid biosynthesis remains to be identified.

  18. Diamondoid diacids ('O4' species) in oil sands process-affected water.

    Science.gov (United States)

    Lengger, Sabine K; Scarlett, Alan G; West, Charles E; Rowland, Steven J

    2013-12-15

    As a by-product of oil sands extraction, large volumes of oil sands process water (OSPW) are generated, which are contaminated with a large range of water-soluble organic compounds. The acids are thought to be derived from hydrocarbons via natural biodegradation pathways such as α- and β-oxidation of alkyl substituents, which could produce mono- and diacids, for example. However, while several monoacids ('O2' species) have been identified, the presence of diacids (i.e. 'O4' species) has only been deduced from results obtained via Fourier transform infrared (FTIR) spectroscopy, Fourier transform ion cyclotron resonance high-resolution mass spectrometry (FTICR-HRMS) and nuclear magnetic resonance ((1)H-NMR) spectroscopy and the structures have never been confirmed. An extract of an OSPW from a Canadian tailings pond was analysed and the retention times and the electron ionization mass spectra of some analytes were compared with those of bis-methyl esters of authentic diacids by gas chromatography × gas chromatography/time-of-flight mass spectrometry (GCxGC/TOFMS) in nominal and accurate mass configurations. Two diamondoid diacids (3-carboxymethyladamantane-1-carboxylic acid and adamantane-1,3-dicarboxylic acid) were firmly identified as their bis-methyl esters by retention time and mass spectral matching and several other structural isomers were more tentatively assigned. Diacids have substantially increased polarity over the hydrocarbon and monoacid species from which they probably derive: as late members of biodegradation processes they may be useful indicators of weathering and ageing, not only of OSPW, but potentially of crude oil residues more generally. Structures of O4 species in OSPW have been identified. This confirms pathways of microbial biodegradation, which were only postulated previously, and may be a further indication that remediation of OSPW toxicity can occur by natural microbial action. The presence and abundance of these diacids might

  19. Assessing the bioremediation potential of algal species indigenous to oil sands process-affected waters on mixtures of oil sands acid extractable organics.

    Science.gov (United States)

    Ruffell, Sarah E; Frank, Richard A; Woodworth, Adam P; Bragg, Leslie M; Bauer, Anthony E; Deeth, Lorna E; Müller, Kirsten M; Farwell, Andrea J; Dixon, D George; Servos, Mark R; McConkey, Brendan J

    2016-11-01

    Surface mining extraction of bitumen from oil sand in Alberta, Canada results in the accumulation of oil sands process-affected water (OSPW). In attempts to maximize water recycling, and because its constituents are recognized as being toxic, OSPW is retained in settling basins. Consequently, research efforts are currently focused on developing remediation strategies capable of detoxifying OSPW to allow for eventual release. One potential bioremediation strategy proposes to utilize phytoplankton native to the Alberta oil sand region to sequester, break down, or modify the complex oil sands acid extractable organic (AEO) mixtures in OSPW. Preliminary attempts to quantify changes in total oil sands AEO concentration in test solutions by ESI-MS following a 14-day algal remediation period revealed the presence of unknown organic acids in control samples, likely released by the phytoplankton strains and often of the same atomic mass range as the oil sands AEO under investigation. To address the presence of these "biogenic" organic acids in test samples, ESI-MS in MRM mode was utilized to identify oil sands AEO "marker ions" that were a) present within the tested oil sands AEO extract and b) unique to the oil sands AEO extract only (e.g. atomic masses different from biogenic organic acids). Using this approach, one of the 21 tested algal strains, Stichococcus sp. 1, proved capable of significantly reducing the AEO marker ion concentration at test concentrations of 10, 30, and 100mgL(-1). This result, along with the accelerated growth rate and recalcitrance of this algal strain with exposure to oil sands AEO, suggests the strong potential for the use of the isolated Stichococcus sp. 1 as a candidate for bioremediation strategies.

  20. Modified biopolymers as sorbents for the removal of naphthenic acids from oil sands process affected water (OSPW).

    Science.gov (United States)

    Arshad, Muhammad; Khosa, M A; Siddique, Tariq; Ullah, Aman

    2016-11-01

    Oil sands operations consume large volumes of water in bitumen extraction process and produce tailings that express pore water to the surface of tailings ponds known as oil sands process-affected water (OSPW). The OSPW is toxic and cannot be released into the environment without treatment. In addition to metals, dissolved solids, dissolved gases, hydrocarbons and polyaromatic compounds etc., OSPW also contains a complex mixture of dissolved organic acids, referred to as naphthenic acids (NAs). The NAs are highly toxic and react with metals to develop highly corrosive functionalities which cause corrosion in the oil sands processing and refining processes. We have chemically modified keratin biopolymer using polyhedral oligomeric silsesquioxanes (POSS) nanocages and goethite dopant to unfold keratinous structure for improving functionality. The untreated neat keratin and two modified sorbents were characterized to investigate structural, morphological, dimensional and thermal properties. These sorbents were then tested for the removal of NAs from OSPW. The NAs were selectively extracted and quantified before and after sorption process. The biosorption capacity (Q), rejection percentage (R%) and isotherm models were studied to investigate NAs removal efficiency of POSS modified keratin biopolymer (PMKB) and goethite modified keratin biopolymer (GMKB) from aliquots of OSPW.

  1. Geochemical interactions between process-affected water from oil sands tailings ponds and North Alberta surficial sediments.

    Science.gov (United States)

    Holden, A A; Donahue, R B; Ulrich, A C

    2011-01-25

    In Northern Alberta, the placement of out-of-pit oil sands tailings ponds atop natural buried sand channels is becoming increasingly common. Preliminary modeling of such a site suggests that process-affected (PA) pond water will infiltrate through the underlying clay till aquitard, reaching the sand channel. However, the impact of seepage upon native sediments and groundwater resources is not known. The goal of this study is to investigate the role of adsorption and ion exchange reactions in the clay till and their effect on the attenuation or release of inorganic species. This was evaluated using batch sorption experiments (traditional and a recent modification using less disturbed sediment samples) and geochemical modeling with PHREEQC. The results show that clay till sediments have the capacity to mitigate the high concentrations of ingressing sodium (600 mg L(-1)), with linear sorption partitioning coefficients (K(d)) of 0.45 L kg(-1). Ion exchange theory was required to account for all other cation behaviour, precluding the calculation of such coefficients for other species. Qualitative evidence suggests that chloride will behave conservatively, with high concentrations remaining in solution (375 mg L(-1)). As a whole, system behaviour was found to be controlled by a combination of competitive ion exchange, dissolution and precipitation reactions. Observations, supported by PHREEQC simulations, suggest that the influx of PA water will induce the dissolution of pre-existing sulphate salts. Sodium present in the process-affected water will exchange with sediment-bound calcium and magnesium, increasing the divalent ions' pore fluid concentrations, and leading to the precipitation of a calcium-magnesium carbonate mineral phase. Thus, in similar tailings pond settings, particularly if the glacial till coverage is thin or altogether absent, it is reasonable to expect that high concentrations of sodium and chloride will remain in solution, while sulphate

  2. Photocatalytic degradation kinetics of naphthenic acids in oil sands process-affected water: Multifactorial determination of significant factors.

    Science.gov (United States)

    Leshuk, Tim; de Oliveira Livera, Diogo; Peru, Kerry M; Headley, John V; Vijayaraghavan, Sucharita; Wong, Timothy; Gu, Frank

    2016-12-01

    Oil sands process-affected water (OSPW) is generated as a byproduct of bitumen extraction in Canada's oil sands. Due to the water's toxicity, associated with dissolved acid extractable organics (AEO), especially naphthenic acids (NAs), along with base-neutral organics, OSPW may require treatment to enable safe discharge to the environment. Heterogeneous photocatalysis is a promising advanced oxidation process (AOP) for OSPW remediation, however, predicting treatment efficacy can be challenging due to the unique water chemistry of OSPW from different tailings ponds. The objective of this work was to study various factors affecting the kinetics of photocatalytic AEO degradation in OSPW. The rate of photocatalytic treatment varied significantly in two different OSPW sources, which could not be accounted for by differences in AEO composition, as studied by high resolution mass spectrometry (HRMS). The effects of inorganic water constituents were investigated using factorial and response surface experiments, which revealed that hydroxyl (HO) radical scavenging by iron (Fe(3+)) and bicarbonate (HCO3(-)) inhibited the NA degradation rate. The effects of NA concentration and temperature on the treatment kinetics were also evaluated in terms of Langmuir-Hinshelwood and Arrhenius models; pH and temperature were identified as weak factors, while dissolved oxygen (DO) was critical to the photo-oxidation reaction. Accounting for all of these variables, a general empirical kinetic expression is proposed, enabling prediction of photocatalytic treatment performance in diverse sources of OSPW.

  3. Degradation and aquatic toxicity of naphthenic acids in oil sands process-affected waters using simulated wetlands.

    Science.gov (United States)

    Toor, Navdeep S; Franz, Eric D; Fedorak, Phillip M; MacKinnon, Michael D; Liber, Karsten

    2013-01-01

    Oil sands process-affected waters (OSPWs) produced during the extraction of bitumen at the Athabasca Oil Sands (AOS) located in northeastern Alberta, Canada, are toxic to many aquatic organisms. Much of this toxicity is related to a group of dissolved organic acids known as naphthenic acids (NAs). Naphthenic acids are a natural component of bitumen and are released into process water during the separation of bitumen from the oil sand ore by a caustic hot water extraction process. Using laboratory microcosms as an analogue of a proposed constructed wetland reclamation strategy for OSPW, we evaluated the effectiveness of these microcosms in degrading NAs and reducing the aquatic toxicity of OSPW over a 52-week test period. Experimental manipulations included two sources of OSPW (one from Syncrude Canada Ltd. and one from Suncor Energy Inc.), two different hydraulic retention times (HRTs; 40 and 400 d), and increased nutrient availability (added nitrate and phosphate). Microcosms with a longer HRT (for both OSPWs) showed higher reductions in total NAs concentrations (64-74% NAs reduction, p100% v/v) independent of HRT. However, EC20s from separate Microtox® bioassays were relatively unchanged when comparing the input and microcosm waters at both HRTs over the 52-week study period (p>0.05), indicating that some sub-lethal toxicity persisted under these experimental conditions. The present study demonstrated that given sufficiently long HRTs, simulated wetland microcosms containing OSPW significantly reduced total NAs concentrations and acute toxicity, but left behind a persistent component of the NAs mixture that appeared to be associated with residual chronic toxicity.

  4. Elucidating mechanisms of toxic action of dissolved organic chemicals in oil sands process-affected water (OSPW).

    Science.gov (United States)

    Morandi, Garrett D; Wiseman, Steve B; Guan, Miao; Zhang, Xiaowei W; Martin, Jonathan W; Giesy, John P

    2017-08-08

    Oil sands process-affected water (OSPW) is generated during extraction of bitumen in the surface-mining oil sands industry in Alberta, Canada, and is acutely and chronically toxic to aquatic organisms. It is known that dissolved organic compounds in OSPW are responsible for most toxic effects, but knowledge of the specific mechanism(s) of toxicity, is limited. Using bioassay-based effects-directed analysis, the dissolved organic fraction of OSPW has previously been fractionated, ultimately producing refined samples of dissolved organic chemicals in OSPW, each with distinct chemical profiles. Using the Escherichia coli K-12 strain MG1655 gene reporter live cell array, the present study investigated relationships between toxic potencies of each fraction, expression of genes and characterization of chemicals in each of five acutely toxic and one non-toxic extract of OSPW derived by use of effects-directed analysis. Effects on expressions of genes related to response to oxidative stress, protein stress and DNA damage were indicative of exposure to acutely toxic extracts of OSPW. Additionally, six genes were uniquely responsive to acutely toxic extracts of OSPW. Evidence presented supports a role for sulphur- and nitrogen-containing chemical classes in the toxicity of extracts of OSPW. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Granular activated carbon for simultaneous adsorption and biodegradation of toxic oil sands process-affected water organic compounds.

    Science.gov (United States)

    Islam, Md Shahinoor; Zhang, Yanyan; McPhedran, Kerry N; Liu, Yang; Gamal El-Din, Mohamed

    2015-04-01

    Naphthenic acids (NAs) released into oil sands process-affected water (OSPW) during bitumen processing in Northern Alberta are problematic for oil sands industries due to their toxicity in the environment and resistance to degradation during conventional wastewater treatment processes. Granular activated carbon (GAC) has shown to be an effective media in removing biopersistent organics from wastewater using a combination of adsorption and biodegradation removal mechanisms. A simultaneous GAC (0.4 g GAC/L) adsorption and biodegradation (combined treatment) study was used for the treatment of raw and ozonated OSPW. After 28 days of batch treatment, classical and oxidized NAs removals for raw OSPW were 93.3% and 73.7%, and for ozonated OSPW were 96.2% and 77.1%, respectively. Synergetic effects of the combined treatment process were observed in removals of COD, the acid extractable fraction, and oxidized NAs, which indicated enhanced biodegradation and bioregeneration in GAC biofilms. A bacteria copy number >10(8) copies/g GAC on GAC surfaces was found using quantitative real time polymerase chain reaction after treatment for both raw and ozonated OSPW. A Microtox(®) acute toxicity test (Vibrio fischeri) showed effective toxicity removal (>95.3%) for the combined treatments. Therefore, the simultaneous GAC adsorption and biodegradation treatment process is a promising technology for the elimination of toxic OSPW NAs.

  6. Reproductive and health assessment of fathead minnows (Pimephales promelas) inhabiting a pond containing oil sands process-affected water

    Energy Technology Data Exchange (ETDEWEB)

    Kavanagh, Richard J., E-mail: rkavanag@uoguelph.ca [Department of Integrative Biology, University of Guelph, Guelph, ON, Canada N1G 2W1 (Canada); Frank, Richard A.; Solomon, Keith R. [Centre for Toxicology, University of Guelph, Guelph, ON, Canada N1G 2W1 (Canada); Van Der Kraak, Glen [Department of Integrative Biology, University of Guelph, Guelph, ON, Canada N1G 2W1 (Canada)

    2013-04-15

    Highlights: ► Fish were collected from a pond containing oil sands process-affected water (OSPW). ► They were compared to fish from two reference sites within the oil sands region. ► Differences in GSIs and tubercle numbers were observed in fish from the OSPW pond. ► Opercula, gills, and 11-KT concentrations also differed in fish from the OSPW pond. ► Black spot and tapeworms were not observed in any of the fish from the OSPW pond. -- Abstract: Previous laboratory based studies have shown that oil sands process-affected waters (OSPWs) containing high concentrations of naphthenic acids (>25 mg/l) have adverse effects on the reproductive physiology of fish. The purpose of this study was to assess the reproductive development and health of a wild population of fathead minnows (Pimephales promelas) inhabiting an OSPW pond that has moderate concentrations of naphthenic acids (∼10 mg/l). Fathead minnows were collected at various times during the period of 2006 through 2008 from Demonstration Pond (OSPW) located at Syncrude Canada Ltd., and two reference sites, Beaver Creek reservoir and Poplar Creek reservoir, which are all north of Fort McMurray, AB, Canada. Condition factor, gill histopathology, gonadosomatic indices, liver somatic indices, male secondary sexual characteristics, and plasma sex steroids were examined. Depending on the time of year that fathead minnows were collected, there were differences in the condition factor, gonadosomatic indices, liver somatic indices, and secondary sexual characteristics of fathead minnows (in males) from Demonstration Pond when compared to the fathead minnows from the reference sites. In comparison to reference fish, lower concentrations of 11-ketotestosterone were measured in the plasma of male fathead minnows collected from Demonstration Pond in June 2006 and July 2007. Black spot disease and Ligula intestinalis were prevalent in fathead minnows from the reference sites but were not observed in fathead minnows

  7. Naphthenic acids speciation and removal during petroleum-coke adsorption and ozonation of oil sands process-affected water.

    Science.gov (United States)

    Gamal El-Din, Mohamed; Fu, Hongjing; Wang, Nan; Chelme-Ayala, Pamela; Pérez-Estrada, Leonidas; Drzewicz, Przemysław; Martin, Jonathan W; Zubot, Warren; Smith, Daniel W

    2011-11-01

    The Athabasca Oil Sands industry produces large volumes of oil sands process-affected water (OSPW) as a result of bitumen extraction and upgrading processes. Constituents of OSPW include chloride, naphthenic acids (NAs), aromatic hydrocarbons, and trace heavy metals, among other inorganic and organic compounds. To address the environmental issues associated with the recycling and/or safe return of OSPW into the environment, water treatment technologies are required. This study examined, for the first time, the impacts of pretreatment steps, including filtration and petroleum-coke adsorption, on ozonation requirements and performance. The effect of the initial OSPW pH on treatment performance, and the evolution of ozonation and its impact on OSPW toxicity and biodegradability were also examined. The degradation of more than 76% of total acid-extractable organics was achieved using a semi-batch ozonation system at a utilized ozone dose of 150 mg/L. With a utilized ozone dose of 100 mg/L, the treated OSPW became more biodegradable and showed no toxicity towards Vibrio fischeri. Changes in the NA profiles in terms of carbon number and number of rings were observed after ozonation. The filtration of the OSPW did not improve the ozonation performance. Petroleum-coke adsorption was found to be effective in reducing total acid-extractable organics by a 91%, NA content by an 84%, and OSPW toxicity from 4.3 to 1.1 toxicity units. The results of this study indicate that the combination of petroleum-coke adsorption and ozonation is a promising treatment approach to treat OSPW.

  8. Treatment of oil sands process-affected water using moving bed biofilm reactors: With and without ozone pretreatment.

    Science.gov (United States)

    Shi, Yijing; Huang, Chunkai; Rocha, Ketley Costa; El-Din, Mohamed Gamal; Liu, Yang

    2015-09-01

    Two moving bed biofilm reactors (MBBRs) were operated to treat raw (untreated) and 30 mg/L ozone-treated oil sands process-affected water (OSPW). After 210 days, the MBBR process showed 18.3% of acid-extractable fraction (AEF) and 34.8% of naphthenic acids (NAs) removal, while the ozonation combined MBBR process showed higher removal of AEF (41.0%) and NAs (78.8%). Biodegradation of raw and ozone treated OSPW showed similar performance. UPLC/HRMS analysis showed a highest NAs removal efficiency with a carbon number of 14 and a -Z number of 4. Confocal laser scanning microscopy (CLSM) showed thicker biofilms in the raw OSPW MBBR (97 ± 5 μm) than in the ozonated OSPW MBBR (71 ± 12 μm). Quantitative polymerase chain reaction (q-PCR) results showed higher abundance of gene copies of total bacteria and nitrogen removal relevant bacteria in the ozonated OSPW MBBR, but no significant difference was found. MiSeq sequencing showed Proteobacteria, Nitrospirae, and Acidobacteria were dominant.

  9. Biostimulation of Oil Sands Process-Affected Water with Phosphate Yields Removal of Sulfur-Containing Organics and Detoxification.

    Science.gov (United States)

    Quesnel, Dean M; Oldenburg, Thomas B P; Larter, Stephen R; Gieg, Lisa M; Chua, Gordon

    2015-11-01

    The ability to mitigate toxicity of oil sands process-affected water (OSPW) for return into the environment is an important issue for effective tailings management in Alberta, Canada. OSPW toxicity has been linked to classical naphthenic acids (NAs), but the toxic contribution of other acid-extractable organics (AEOs) remains unknown. Here, we examine the potential for in situ bioremediation of OSPW AEOs by indigenous algae. Phosphate biostimulation was performed in OSPW to promote the growth of indigenous photosynthetic microorganisms and subsequent toxicity and chemical changes were determined. After 12 weeks, the AEO fraction of phosphate-biostimulated OSPW was significantly less toxic to the fission yeast Schizosaccharomyces pombe than unstimulated OSPW. Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) analysis of the AEO fraction in phosphate-biostimulated OSPW showed decreased levels of SO3 class compounds, including a subset that may represent linear arylsulfonates. A screen with S. pombe transcription factor mutant strains for growth sensitivity to the AEO fraction or sodium dodecylbenzenesulfonate revealed a mode of toxic action consistent with oxidative stress and detrimental effects on cellular membranes. These findings demonstrate a potential algal-based in situ bioremediation strategy for OSPW AEOs and uncover a link between toxicity and AEOs other than classical NAs.

  10. Assessing spatial and temporal variability of acid-extractable organics in oil sands process-affected waters.

    Science.gov (United States)

    Frank, Richard A; Milestone, Craig B; Rowland, Steve J; Headley, John V; Kavanagh, Richard J; Lengger, Sabine K; Scarlett, Alan G; West, Charles E; Peru, Kerry M; Hewitt, L Mark

    2016-10-01

    The acid-extractable organic compounds (AEOs), including naphthenic acids (NAs), present within oil sands process-affected water (OSPW) receive great attention due to their known toxicity. While recent progress in advanced separation and analytical methodologies for AEOs has improved our understanding of the composition of these mixtures, little is known regarding any variability (i.e., spatial, temporal) inherent within, or between, tailings ponds. In this study, 5 samples were collected from the same location of one tailings pond over a 2-week period. In addition, 5 samples were collected simultaneously from different locations within a tailings pond from a different mine site, as well as its associated recycling pond. In both cases, the AEOs were analyzed using SFS, ESI-MS, HRMS, GC×GC-ToF/MS, and GC- & LC-QToF/MS (GC analyses following conversion to methyl esters). Principal component analysis of HRMS data was able to distinguish the ponds from each other, while data from GC×GC-ToF/MS, and LC- and GC-QToF/MS were used to differentiate samples from within the temporal and spatial sample sets, with the greater variability associated with the latter. Spatial differences could be attributed to pond dynamics, including differences in inputs of tailings and surface run-off. Application of novel chemometric data analyses of unknown compounds detected by LC- and GC-QToF/MS allowed further differentiation of samples both within and between data sets, providing an innovative approach for future fingerprinting studies.

  11. Desalination of oil sands process-affected water and basal depressurization water in Fort McMurray, Alberta, Canada: application of electrodialysis.

    Science.gov (United States)

    Kim, Eun-Sik; Dong, Shimiao; Liu, Yang; Gamal El-Din, Mohamed

    2013-01-01

    The high content of inorganic species in water used to extract bitumen from the Alberta oil sands and in the groundwater below the oil sands is an increasing environmental concern. These water matrices require treatment before they can be reused or safely discharged. Desalination of the oil sands process-affected water (OSPW) and groundwater, or basal depressurization water (BDW), can be accomplished with deionization techniques such as electrodialysis (ED). In order to achieve the effective ED treatment, OSPW and BDW were pretreated with coagulation-flocculation-sedimentation to remove solid species and turbidity. We demonstrated that a conductivity range for industrial reuse of OSPW and BDW can be achieved with the ED treatment and showed the possibility of applying ED in the oil sands industry. A continuous ED system that reuses the diluate stream as a source for the concentrate stream was designed. The cost of a hypothetical ED water treatment plant in Fort McMurray, Alberta, was estimated to be C$10.71 per cubic meter of treated water.

  12. A risk-based approach for identifying constituents of concern in oil sands process-affected water from the Athabasca Oil Sands region.

    Science.gov (United States)

    McQueen, Andrew D; Kinley, Ciera M; Hendrikse, Maas; Gaspari, Daniel P; Calomeni, Alyssa J; Iwinski, Kyla J; Castle, James W; Haakensen, Monique C; Peru, Kerry M; Headley, John V; Rodgers, John H

    2017-04-01

    Mining leases in the Athabasca Oil Sands (AOS) region produce large volumes of oil sands process-affected water (OSPW) containing constituents that limit beneficial uses and discharge into receiving systems. The aim of this research is to identify constituents of concern (COCs) in OSPW sourced from an active settling basin with the goal of providing a sound rational for developing mitigation strategies for using constructed treatment wetlands for COCs contained in OSPW. COCs were identified through several lines of evidence: 1) chemical and physical characterization of OSPW and comparisons with numeric water quality guidelines and toxicity endpoints, 2) measuring toxicity of OSPW using a taxonomic range of sentinel organisms (i.e. fish, aquatic invertebrates, and a macrophyte), 3) conducting process-based manipulations (PBMs) of OSPW to alter toxicity and inform treatment processes, and 4) discerning potential treatment pathways to mitigate ecological risks of OSPW based on identification of COCs, toxicological analyses, and PBM results. COCs identified in OSPW included organics (naphthenic acids [NAs], oil and grease [O/G]), metals/metalloids, and suspended solids. In terms of species sensitivities to undiluted OSPW, fish ≥ aquatic invertebrates > macrophytes. Bench-scale manipulations of the organic fractions of OSPW via PBMs (i.e. H2O2+UV254 and granular activated charcoal treatments) eliminated toxicity to Ceriodaphnia dubia (7-8 d), in terms of mortality and reproduction. Results from this study provide critical information to inform mitigation strategies using passive or semi-passive treatment processes (e.g., constructed treatment wetlands) to mitigate ecological risks of OSPW to aquatic organisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Isolation and estimation of the 'aromatic' naphthenic acid content of an oil sands process-affected water extract.

    Science.gov (United States)

    Jones, David; West, Charles E; Scarlett, Alan G; Frank, Richard A; Rowland, Steven J

    2012-07-20

    The naphthenic acids of oil sands process-affected water (OSPW) are said to be important toxicants. The major acids are stated to have alicyclic structures and recently, numerous of these have been identified, but some evidence suggests 'aromatic' acids are also present. The proportions of such acids have not been reported because they exist in so-called supercomplex mixtures with the alicyclic species. Their contribution to the toxicity of OSPW, if any, is therefore unknown. Here we report the use of multidimensional comprehensive gas chromatography-mass spectrometry (GC×GC-MS) with polar first dimension and non-polar second dimension GC columns and argentation solid phase extraction, to separate methyl esters of the acids of an OSPW supercomplex, into distinct fractions. A major fraction (ca 70%) was shown to contain acids (methyl esters) previously identified as alicyclic species. Authentic adamantane acid methyl esters were shown to chromatograph in this fraction. This fraction was isolated by argentation solid phase extraction (SPE) by elution with hexane. GC-MS and GC×GC-MS confirmed this to be the major fraction in the original supercomplex containing alicyclic acids (methyl esters). A second fraction shown to contain monoaromatic acids (methyl esters) by GC×GC-MS was unexpectedly abundant (ca 30% relative to the acyclic acids). The naphtheno-aromatic dehydroabietic acid was confirmed by co-injection with an authentic compound and several acids previously tentatively identified as naphtheno-monoaromatics were present. This fraction was isolated by argentation SPE by elution with more polar 5% diethyl ether in hexane. GC-MS and GC×GC-MS confirmed that the fraction represented a significant proportion of the original supercomplex. A further fraction, eluting from the argentation SPE column with more 5% diethyl ether in hexane in the same retention volume as authentic methyl naphthoate, contained, in addition to some of the second fraction, a third, much

  14. Monitoring the Effects of Oil Sands Process-Affected Water (OSPW) on Thecamoebian Assemblages: An Experimental Approach

    Science.gov (United States)

    Christie, D. G.; McCarthy, F. F.; Penner, T.; MacKinnon, M. M.

    2009-05-01

    Thecamoebian (testate amoeba) assemblages have been shown to respond over short time periods to environmental conditions in aquatic reclamation options under development at oil sands operations in northeastern Alberta. This makes them a useful bio-monitoring tool for assessing reclamation success. Thecamoebian responses to Oil Sands Process Water (OSPW) have been monitored in the field at lacustrine and wetland test sites established by Syncrude Canada Ltd. and Suncor Energy Ltd. These field studies have confirmed that the generation times of testate amoebas is sufficiently rapid to permit the construction of a controlled laboratory experiment to be completed within one year, where controlled exposures of a natural assemblage of thecamoebians to OSPW can be undertaken to better understand the community responses to stressors We intend to culture these protists in the lab and monitor their response to different concentrations of OSPW in a controlled environment. Survival and changes in relative community composition (difflugiids vs. centropyxids) will be used to establish the dilution of OSPW in which thecameobians can survive and examine how a natural assemblage changes over time in response to increased concentrations of OSPW. This will assist in reclamation management in the Oil Sands region of Alberta.

  15. An omic approach for the identification of oil sands process-affected water compounds using multivariate statistical analysis of ultrahigh resolution mass spectrometry datasets.

    Science.gov (United States)

    Chen, Yuan; McPhedran, Kerry N; Perez-Estrada, Leonidas; Gamal El-Din, Mohamed

    2015-04-01

    Oil sands process-affected water (OSPW) is a major environmental issue due to its acute and chronic toxicity to aquatic life. Advanced oxidation processes are promising treatments to successfully degrade toxic OSPW compounds. This study applied high resolution mass spectrometry to detect over 1000 compounds in OSPW samples after treatments including general ozonation, and ozone with carbonate, tert-butyl-alcohol, carbonate/tert-butyl-alcohol, tetranitromethane, or iron. Hierarchal clustering analysis showed that samples clustered based on sampling time and principal component analysis corroborated these results while also providing information on significant markers responsible for the clustering. Some markers were uniquely present in certain treatment conditions, while others showed variable behaviors in two or more treatments due to the presence of scavengers/catalysts. This advanced approach to monitoring significant changes of markers by using multivariate analysis can be invaluable for future work on OSPW treatment by-products and their potential toxicity to receiving environment organisms.

  16. Potential of capillary electrophoresis mass spectrometry for the characterization and monitoring of amine-derivatized naphthenic acids from oil sands process-affected water.

    Science.gov (United States)

    MacLennan, Matthew S; Tie, Cai; Kovalchik, Kevin; Peru, Kerry M; Zhang, Xinxiang; Headley, John V; Chen, David D Y

    2016-11-01

    Capillary electrophoresis coupled to mass spectrometry (CE-MS) was used for the analysis of naphthenic acid fraction compounds (NAFCs) of oil sands process-affected water (OSPW). A standard mixture of amine-derivatized naphthenic acids is injected directly onto the CE column and analyzed by CE-MS in less than 15min. Time of flight MS analysis (TOFMS), optimized for high molecular weight ions, showed NAFCs between 250 and 800m/z. With a quadrupole mass analyzer, only low-molecular weight NAFCs (between 100 and 450m/z) are visible under our experimental conditions. Derivatization of NAFCs consisted of two-step amidation reactions mediated by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), or mediated by a mixture of EDC and N-hydroxysuccinimide, in dimethyl sulfoxide, dichloromethane or ethyl acetate. The optimum background electrolyte composition was determined to be 30% (V/V) methanol in water and 2% (V/V) formic acid. NAFCs extracted from OSPW in the Athabasca oil sands region were used to demonstrate the feasibility of CE-MS for the analysis of NAFCs in environmental samples, showing that the labeled naphthenic acids are in the mass range of 350 to 1500m/z. Copyright © 2016. Published by Elsevier B.V.

  17. Prediction of naphthenic acid species degradation by kinetic and surrogate models during the ozonation of oil sands process-affected water.

    Science.gov (United States)

    Islam, Md Shahinoor; Moreira, Jesús; Chelme-Ayala, Pamela; Gamal El-Din, Mohamed

    2014-09-15

    Oil sands process-affected water (OSPW) is a complex mixture of organic and inorganic contaminants, and suspended solids, generated by the oil sands industry during the bitumen extraction process. OSPW contains a large number of structurally diverse organic compounds, and due to variability of the water quality of different OSPW matrices, there is a need to select a group of easily measured surrogate parameters for monitoring and treatment process control. In this study, kinetic and surrogate correlation models were developed to predict the degradation of naphthenic acids (NAs) species during the ozonation of OSPW. Additionally, the speciation and distribution of classical and oxidized NA species in raw and ozonated OSPW were also examined. The structure-reactivity of NA species indicated that the reactivity of individual NA species increased as the carbon and hydrogen deficiency numbers increased. The kinetic parameters obtained in this study allowed calculating the evolution of the concentrations of the acid-extractable fraction (AEF), chemical oxygen demand (COD), and NA distributions for a given ozonation process. High correlations between the AEF and COD and NA species were found, suggesting that AEF and COD can be used as surrogate parameters to predict the degradation of NAs during the ozonation of OSPW.

  18. Naphthenic Acid Mixtures from Oil Sands Process-Affected Water Enhance Differentiation of Mouse Embryonic Stem Cells and Affect Development of the Heart.

    Science.gov (United States)

    Mohseni, Paria; Hahn, Noah A; Frank, Richard A; Hewitt, L Mark; Hajibabaei, Mehrdad; Van Der Kraak, Glen

    2015-08-18

    Extraction of petrochemicals from the surface mining of oil sand deposits results in generation of large volumes of oil sands process-affected water (OSPW). Naphthenic acids (NA) are generally considered to be among the most toxic components of OSPW. Previous studies have shown that NAs are toxic to aquatic organisms, however knowledge of their effects on mammalian health and development is limited. In the present study, we evaluated the developmental effects of an NA extract prepared from fresh OSPW on differentiating mouse embryonic stem cells (ESC). We found that treatment of differentiating cells with the NA extract at noncytotoxic concentrations alters expression of various lineage specification markers and development of the heart. Notably, expression of cardiac specific markers such as Nkx2.5, Gata4, and Mef2c were significantly up-regulated. Moreover, exposure to the NA extract enhanced differentiation of embryoid bodies and resulted in the early appearance of spontaneously beating clusters. Interestingly, exposure of undifferentiated mouse ESCs to the NA extract did not change the expression level of pluripotency markers (i.e., Oct4, Nanog, and Sox2). Altogether, these data identify some of the molecular pathways affected by components within this NA extract during differentiation of mammalian cells.

  19. Toxicokinetics and toxicodynamics of chlorpyrifos is altered in embryos of Japanese medaka exposed to oil sands process-affected water: evidence for inhibition of P-glycoprotein.

    Science.gov (United States)

    Alharbi, Hattan A; Alcorn, Jane; Al-Mousa, Ahmed; Giesy, John P; Wiseman, Steve B

    2016-10-24

    Oil sands process-affected water (OSPW) is generated during extraction of bitumen in the surface mining oil sands industry in Alberta, Canada. Studies were performed in vitro by use of Caco-2 cells, and in vivo with larvae of Japanese medaka (Oryzias latipes) to determine if organic compounds from the aqueous phase of OSPW inhibit ATP binding cassette protein ABCB1 (permeability-glycoprotein, P-gp). Neutral and basic fractions of OSPW inhibited activity of P-gp in Caco-2 cells by 1.9- and 2.0-fold, respectively, while the acidic fraction had the least effect. The organophosphate pesticides chlorpyrifos (a substrate of P-gp) and malathion (not a substrate of P-gp), were used as model chemicals to investigate inhibition of P-gp in larvae. Co-exposure to chlorpyrifos and an extract of OSPW containing basic and neutral compounds reduced survival of larvae to 26.5% compared to survival of larvae exposed only to chlorpyrifos, which was 93.7%. However, co-exposure to malathion and the extract of OSPW did not cause acute lethality compared to exposure only to malathion. Accumulation and bioconcentration of chlorpyrifos, but not malathion, was greater in larvae co-exposed with the extract of OSPW. The terminal elimination half-life of chlorpyrifos in larvae exposed to chlorpyrifos in freshwater was 5 days compared with 11.3 days in larvae exposed to chlorpyrifos in OSPW. Results suggest that in non-acute exposures, basic and neutral organic compounds in the water-soluble fraction of OSPW inhibit activity of P-gp, which suggests that OSPW has the potential to cause adverse effects by chemosensitization. Copyright © 2016 John Wiley & Sons, Ltd.

  20. Removal of organic compounds and trace metals from oil sands process-affected water using zero valent iron enhanced by petroleum coke.

    Science.gov (United States)

    Pourrezaei, Parastoo; Alpatova, Alla; Khosravi, Kambiz; Drzewicz, Przemysław; Chen, Yuan; Chelme-Ayala, Pamela; Gamal El-Din, Mohamed

    2014-06-15

    The oil production generates large volumes of oil sands process-affected water (OSPW), referring to the water that has been in contact with oil sands or released from tailings deposits. There are concerns about the environmental impacts of the release of OSPW because of its toxicity. Zero valent iron alone (ZVI) and in combination with petroleum coke (CZVI) were investigated as environmentally friendly treatment processes for the removal of naphthenic acids (NAs), acid-extractable fraction (AEF), fluorophore organic compounds, and trace metals from OSPW. While the application of 25 g/L ZVI to OSPW resulted in 58.4% removal of NAs in the presence of oxygen, the addition of 25 g petroleum coke (PC) as an electron conductor enhanced the NAs removal up to 90.9%. The increase in ZVI concentration enhanced the removals of NAs, AEF, and fluorophore compounds from OSPW. It was suggested that the electrons generated from the oxidation of ZVI were transferred to oxygen, resulting in the production of hydroxyl radicals and oxidation of NAs. When OSPW was de-oxygenated, the NAs removal decreased to 17.5% and 65.4% during treatment with ZVI and CZVI, respectively. The removal of metals in ZVI samples was similar to that obtained during CZVI treatment. Although an increase in ZVI concentration did not enhance the removal of metals, their concentrations effectively decreased at all ZVI loadings. The Microtox(®) bioassay with Vibrio fischeri showed a decrease in the toxicity of ZVI- and CZVI-treated OSPW. The results obtained in this study showed that the application of ZVI in combination with PC is a promising technology for OSPW treatment. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Impact of ozonation pre-treatment of oil sands process-affected water on the operational performance of a GAC-fluidized bed biofilm reactor.

    Science.gov (United States)

    Islam, Md Shahinoor; Dong, Tao; McPhedran, Kerry N; Sheng, Zhiya; Zhang, Yanyan; Liu, Yang; Gamal El-Din, Mohamed

    2014-11-01

    Treatment of oil sands process-affected water (OSPW) using biodegradation has the potential to be an environmentally sound approach for tailings water reclamation. This process is both economical and efficient, however, the recalcitrance of some OSPW constituents, such as naphthenic acids (NAs), require the pre-treatment of raw OSPW to improve its biodegradability. This study evaluated the treatment of OSPW using ozonation followed by fluidized bed biofilm reactor (FBBR) using granular activated carbon (GAC). Different organic and hydraulic loading rates were applied to investigate the performance of the bioreactor over 120 days. It was shown that ozonation improved the adsorption capacity of GAC for OSPW and improved biodegradation by reducing NAs cyclicity. Bioreactor treatment efficiencies were dependent on the organic loading rate (OLR), and to a lesser degree, the hydraulic loading rate (HLR). The combined ozonation, GAC adsorption, and biodegradation process removed 62 % of chemical oxygen demand (COD), 88 % of acid-extractable fraction (AEF) and 99.9 % of NAs under optimized operational conditions. Compared with a planktonic bacterial community in raw and ozonated OSPW, more diverse microbial communities were found in biofilms colonized on the surface of GAC after 120 days, with various carbon degraders found in the bioreactor including Burkholderia multivorans, Polaromonas jejuensis and Roseomonas sp.

  2. Adsorption of acid-extractable organics from oil sands process-affected water onto biomass-based biochar: Metal content matters.

    Science.gov (United States)

    Bhuiyan, Tazul I; Tak, Jin K; Sessarego, Sebastian; Harfield, Don; Hill, Josephine M

    2017-02-01

    The impact of biochar properties on acid-extractable organics (AEO) adsorption from oil sands process-affected water (OSPW) was studied. Biochar from wheat straw with the highest ash content (14%) had the highest adsorption capacity (0.59 mg/g) followed by biochar from pulp mill sludge, switchgrass, mountain pine, hemp shives, and aspen wood. The adsorption capacity had no obvious trend with surface area, total pore volume, bulk polarity and aromaticity. The large impact of metal content was consistent with the carboxylates (i.e., naphthenate species) in the OSPW binding to the metals (mainly Al and Fe) on the carbon substrate. Although the capacity of biochar is still approximately two orders of magnitude lower than that of a commercial activated carbon, confirming the property (i.e., metal content) that most influenced AEO adsorption, may allow biochar to become competitive with activated carbon after normalizing for cost, especially if this cost includes environmental impacts. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Treatment of oil sands process-affected water (OSPW) using a membrane bioreactor with a submerged flat-sheet ceramic microfiltration membrane.

    Science.gov (United States)

    Xue, Jinkai; Zhang, Yanyan; Liu, Yang; Gamal El-Din, Mohamed

    2016-01-01

    The release of oil sands process-affected water (OSPW) into the environment is a concern because it contains persistent organic pollutants that are toxic to aquatic life. A modified Ludzack-Ettinger membrane bioreactor (MLE-MBR) with a submerged ceramic membrane was continuously operated for 425 days to evaluate its feasibility on OSPW treatment. A stabilized biomass concentration of 3730 mg mixed liquor volatile suspended solids per litre and a naphthenic acid (NA) removal of 24.7% were observed in the reactor after 361 days of operation. Ultra Performance Liquid Chromatography/High Resolution Mass Spectrometry analysis revealed that the removal of individual NA species declined with increased ring numbers. Pyrosequencing analysis revealed that Betaproteobacteria were dominant in sludge samples from the MLE-MBR, with microorganisms such as Rhodocyclales and Sphingobacteriales capable of degrading hydrocarbon and aromatic compounds. During 425 days of continuous operation, no severe membrane fouling was observed as the transmembrane pressure (TMP) of the MLE-MBR never exceeded -20 kPa given that the manufacturer's suggested critical TMP for chemical cleaning is -35 kPa. Our results indicated that the proposed MLE-MBR has a good potential for removing recalcitrant organics in OSPW.

  4. Coagulation/flocculation process with polyaluminum chloride for the remediation of oil sands process-affected water: Performance and mechanism study.

    Science.gov (United States)

    Wang, Chengjin; Alpatova, Alla; McPhedran, Kerry N; Gamal El-Din, Mohamed

    2015-09-01

    This study investigated the application of polyaluminum chloride (PACl) for the treatment of the oil sands process-affected water (OSPW). These coagulants are commonly used in water treatment with the most effective species reported to be Al13. PACl with 83.6% Al13 was synthesized using the slow base titration method and compared with a commercially available PACl in terms of aluminum species distribution, coagulation/flocculation (CF) performance, floc morphology, and contaminant removal. Both coagulants were effective in removing suspended solids, achieving over 96% turbidity removal at all applied coagulant doses (0.5-3.0 mM Al). The removal efficiencies of metals varied among different metals depending on their pKa values with metal cations having pKa values (Fe, Al, Ga, and Ti) below OSPW pH of 6.9-8.1 (dose dependent) being removed by more than 90%, while cations with higher pKa values (K, Na, Ca, Mg and Ni) had removals of less than 40%. Naphthenic acids were not removed due to their low molecular weights, negative charges, and hydrophilic characteristics at the OSPW pH. At the highest applied coagulant dose of 3.0 mM Al, the synthetic PACl reduced Vibrio fischeri inhibition effect to 43.3 ± 3.0% from 49.5 ± 0.4% in raw OSPW. In contrast, no reduction of toxicity was found for OSPW treated with the commercial PACl. Based on water quality and floc analyses, the dominant CF mechanism for particle removal during OSPW treatment was considered to be enmeshment in the precipitates (i.e., sweep flocculation). Overall, the CF using synthesized PACl can be a valuable pretreatment process for OSPW to create wastewater that is more easily treated by downstream processes.

  5. Fractionation of oil sands-process affected water using pH-dependent extractions: a study of dissociation constants for naphthenic acids species.

    Science.gov (United States)

    Huang, Rongfu; Sun, Nian; Chelme-Ayala, Pamela; McPhedran, Kerry N; Changalov, Mohamed; Gamal El-Din, Mohamed

    2015-05-01

    The fractionation of oil sands process-affected water (OSPW) via pH-dependent extractions was performed to quantitatively investigate naphthenic acids (NAs, CnH2n+ZO2) and oxidized NAs (Ox-NAs) species (CnH2n+ZO3 and CnH2n+ZO4) using ultra-performance liquid chromatography time-of-flight mass spectrometry (UPLC-TOFMS). A mathematical model was also developed to estimate the dissociation constant pKa for NAs species, considering the liquid-liquid extraction process and the aqueous layer acid-base equilibrium. This model provides estimated dissociation constants for compounds in water samples based on fractionation extraction and relative quantification. Overall, the sum of O2-, O3-, and O4-NAs species accounted for 33.6% of total extracted organic matter. Accumulative extracted masses at different pHs revealed that every oxygen atom added to NAs increases the pKa (i.e., O2-NAs

  6. Acute toxicity of aromatic and non-aromatic fractions of naphthenic acids extracted from oil sands process-affected water to larval zebrafish.

    Science.gov (United States)

    Scarlett, A G; Reinardy, H C; Henry, T B; West, C E; Frank, R A; Hewitt, L M; Rowland, S J

    2013-09-01

    The toxicity of oil sands process-affected water (OSPW) has regularly been attributed to naphthenic acids, which exist in complex mixtures. If on remediation treatment (e.g., ozonation) or on entering the environment, the mixtures of these acids all behave in the same way, then they can be studied as a whole. If, however, some acids are resistant to change, whilst others are not, or are less resistant, it is important to establish which sub-classes of acids are the most toxic. In the present study we therefore assayed the acute toxicity to larval fish, of a whole acidified OSPW extract and an esterifiable naphthenic acids fraction, de-esterified with alkali: both fractions were toxic (LC50 ∼5-8mgL(-1)). We then fractionated the acids by argentation solid phase extraction of the esters and examined the acute toxicity of two fractions: a de-esterified alicyclic acids fraction, which contained, for example, adamantane and diamantane carboxylic acids, and an aromatic acids fraction. The alicyclic acids were toxic (LC50 13mgL(-1)) but the higher molecular weight aromatic acids fraction was somewhat more toxic, at least on a weight per volume basis (LC50 8mgL(-1); P<0.05) (for comparison, the monoaromatic dehydroabietic acid had a LC50 of ∼1mgL(-1)). These results show how toxic naphthenic acids of OSPW are to these larval fish and that on a weight per volume basis, the aromatic acids are at least as toxic as the 'classical' alicyclic acids. The environmental fates and other toxic effects, if any, of the fractions remain to be established. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. The effect of oil sands process-affected water and model naphthenic acids on photosynthesis and growth in Emiliania huxleyi and Chlorella vulgaris.

    Science.gov (United States)

    Beddow, Jessica; Johnson, Richard J; Lawson, Tracy; Breckels, Mark N; Webster, Richard J; Smith, Ben E; Rowland, Steven J; Whitby, Corinne

    2016-02-01

    Naphthenic acids (NAs) are among the most toxic organic pollutants present in oil sands process waters (OSPW) and enter marine and freshwater environments through natural and anthropogenic sources. We investigated the effects of the acid extractable organic (AEO) fraction of OSPW and individual surrogate NAs, on maximum photosynthetic efficiency of photosystem II (PSII) (FV/FM) and cell growth in Emiliania huxleyi and Chlorella vulgaris as representative marine and freshwater phytoplankton. Whilst FV/FM in E. huxleyi and C. vulgaris was not inhibited by AEO, exposure to two surrogate NAs: (4'-n-butylphenyl)-4-butanoic acid (n-BPBA) and (4'-tert-butylphenyl)-4-butanoic acid (tert-BPBA), caused complete inhibition of FV/FM in E. huxleyi (≥10 mg L(-1)n-BPBA; ≥50 mg L(-1)tert-BPBA) but not in C. vulgaris. Growth rates and cell abundances in E. huxleyi were also reduced when exposed to ≥10 mg L(-1)n- and tert-BPBA; however, higher concentrations of n- and tert-BPBA (100 mg L(-1)) were required to reduce cell growth in C. vulgaris. AEO at ≥10 mg L(-1) stimulated E. huxleyi growth rate (p ≤ 0.002), yet had no apparent effect on C. vulgaris. In conclusion, E. huxleyi was generally more sensitive to NAs than C. vulgaris. This report provides a better understanding of the physiological responses of phytoplankton to NAs which will enable improved monitoring of NA pollution in aquatic ecosystems in the future.

  8. Potential for in situ chemical oxidation of acid extractable organics in oil sands process affected groundwater.

    Science.gov (United States)

    Sohrabi, V; Ross, M S; Martin, J W; Barker, J F

    2013-11-01

    The process of bitumen extraction from oil sands in Alberta, Canada leads to an accumulation of toxic acid-extractable organics (AEOs) in oil sands process water (OSPW). Infiltration of OSPW from tailings ponds and from their retaining sand dykes and subsequent transport towards surface water has occurred. Given the apparent lack of significant natural attenuation of AEOs in groundwater, remediation may be required. This laboratory study evaluates the potential use of unactivated persulfate and permanganate as in situ oxidation agents for remediation of AEOs in groundwater. Naphthenic acids (NAs; CnH2n+zO2), which are a component of the acutely toxic AEOs, were degraded by both oxidants in OSPW samples. Permanganate oxidation yielded some residual dissolved organic carbon (DOC) whereas persulfate mineralized the AEO compounds with less residual DOC. Acid-extractable organics from oxidized OSPW had essentially no Microtox toxicity.

  9. Aromatic naphthenic acids in oil sands process-affected water, resolved by GCxGC-MS, only weakly induce the gene for vitellogenin production in zebrafish (Danio rerio) larvae.

    Science.gov (United States)

    Reinardy, Helena C; Scarlett, Alan G; Henry, Theodore B; West, Charles E; Hewitt, L Mark; Frank, Richard A; Rowland, Steven J

    2013-06-18

    Process waters from oil sands industries (OSPW) have been reported to exhibit estrogenic effects. Although the compounds responsible are unknown, some aromatic naphthenic acids (NA) have been implicated. The present study was designed to investigate whether aromatic NA might cause such effects. Here we demonstrate induction of vitellogenin genes (vtg) in fish, which is a common bioassay used to indicate effects consistent with exposure to exogenous estrogens. Solutions in water of 20-2000 μg L(-1) of an extract of a total OSPW NA concentrate did not induce expression of vtg in larval zebrafish, consistent with earlier studies which showed that much higher NA concentrations of undiluted OSPW were needed. Although 20-2000 μg L(-1) of an esterifiable NA subfraction of the OSPW NA concentrate did induce expression, this was of much lower magnitude to that induced by much lower concentrations of 17α-ethynyl estradiol, indicating that the effect of the total NAs was only weak. However, given the high NA concentrations and large volumes of OSPW extant in Canada, it is important to ascertain which of these esterifiable NA in the OSPW produce the effect. Up to 1000 μg L(-1) of an OSPW subfraction containing only alicyclic NA, and considered by most authors to be NA sensu stricto, did not produce induction; but, as predicted, 10-1000 μg L(-1) of an aromatic NA fraction did. Such effects by the aromatic acids are again consistent with those of only a weak estrogenic substance. These findings may help to focus studies of the most environmentally significant OSPW-related pollutants, if reproduced in a greater range of OSPW.

  10. Sand and Water Table Play

    Science.gov (United States)

    Wallace, Ann H.; White, Mary J.; Stone, Ryan

    2010-01-01

    The authors observed preschoolers engaged at the sand and water table to determine if math could be found within their play. Wanting to understand how children interact with provided materials and what kinds of math ideas they explore during these interactions, the authors offer practical examples of how such play can promote mathematical…

  11. Sand and Water Table Play

    Science.gov (United States)

    Wallace, Ann H.; White, Mary J.; Stone, Ryan

    2010-01-01

    The authors observed preschoolers engaged at the sand and water table to determine if math could be found within their play. Wanting to understand how children interact with provided materials and what kinds of math ideas they explore during these interactions, the authors offer practical examples of how such play can promote mathematical…

  12. Impact on sand and water

    NARCIS (Netherlands)

    Bergmann, R.P.H.M.

    2007-01-01

    In this thesis we investigate the impact of a body on sand and water. When a body impacts a free surface in the inertial regime the series of events is the following: On impact material is blown away in all directions and an impact cavity forms. Due to the hydrostatic pressure from the sides the cav

  13. Conditions and processes affecting sand resources at archeological sites in the Colorado River corridor below Glen Canyon Dam, Arizona

    Science.gov (United States)

    East, Amy E.; Collins, Brian D.; Sankey, Joel B.; Corbett, Skye C.; Fairley, Helen C.; Caster, Joshua

    2016-05-17

    This study examined links among fluvial, aeolian, and hillslope geomorphic processes that affect archeological sites and surrounding landscapes in the Colorado River corridor downstream from Glen Canyon Dam, Arizona. We assessed the potential for Colorado River sediment to enhance the preservation of river-corridor archeological resources through aeolian sand deposition or mitigation of gully erosion. By identifying locally prevailing wind directions, locations of modern sandbars, and likely aeolian-transport barriers, we determined that relatively few archeological sites are now ideally situated to receive aeolian sand supply from sandbars deposited by recent controlled floods. Whereas three-fourths of the 358 river-corridor archeological sites we examined include Colorado River sediment as an integral component of their geomorphic context, only 32 sites currently appear to have a high degree of connectivity (coupled interactions) between modern fluvial sandbars and sand-dominated landscapes downwind. This represents a substantial decrease from past decades, as determined by aerial-photograph analysis. Thus, we infer that recent controlled floods have had a limited, and declining, influence on archeological-site preservation.

  14. Water quality and processes affecting dissolved oxygen concentrations in the Blackwater River, Canaan Valley, West Virginia

    Science.gov (United States)

    Waldron, M.C.; Wiley, J.B.

    1996-01-01

    The water quality and environmental processes affecting dissolved oxygen were determined for the Blackwater River in Canaan Valley, West Virginia. Canaan Valley is oval-shaped (14 miles by 5 miles) and is located in the Allegheny Mountains at an average elevation of 3,200 feet above sea level. Tourism, population, and real estate development have increased in the past two decades. Most streams in Canaan Valley are a dilute calcium magnesium bicarbonate-type water. Streamwater typicaly was soft and low in alkalinity and dissolved solids. Maximum values for specific conductance, hardness, alkalinity, and dissolved solids occurred during low-flow periods when streamflow was at or near baseflow. Dissolved oxygen concentrations are most sensitive to processes affecting the rate of reaeration. The reaeration is affected by solubility (atmospheric pressure, water temperature, humidity, and cloud cover) and processes that determine stream turbulence (stream depth, width, velocity, and roughness). In the headwaters, photosynthetic dissolved oxygen production by benthic algae can result in supersaturated dissolved oxygen concentrations. In beaver pools, dissolved oxygen consumption from sediment oxygen demand and carbonaceous biochemical oxygen demand can result in dissolved oxygen deficits.

  15. Water management in the oil sands industry

    Energy Technology Data Exchange (ETDEWEB)

    Pauls, R. [Syncrude Canada Ltd., Fort McMurray, AB (Canada)

    2004-07-01

    Water management issues at Alberta's 4 oil sand deposits were discussed. The 4 deposits include the Peace River, Athabasca, Wabasca and Cold Lake deposits, with the Athabasca deposit being the largest and the only surface-mineable deposit. Large quantities of water are needed to extract bitumen from oil sands. This paper addressed water volume withdrawal from the Athabasca River, the primary source of water for the surface-mining oil sands industry. It also addressed Muskeg River watershed integrity, quality of water withdrawn from reclaimed landscapes, groundwater contamination, and ecological viability of end-pit lakes. Currently, half of Syncrude's oil sand is transported from mine to extraction plant by conveyor belts. The other half is pipelined as a warm water slurry. By 2005, all transport will be by pipeline. The oil sand is mixed with hot water, steam and surfactants to condition it for extraction. Seventy-nine per cent of the water used by Syncrude is recycled water and the remainder comes from the Athabasca River. Syncrude diverts 2.5 to 3 barrels of water from the Athabasca River for every barrel of oil produced. This paper discussed the in-stream flow needs of the Athabasca River based on protection of aquatic ecosystems. Flow needs are addressed by the Cumulative Effects Management Association (CEMA). The paper states that the proportion of annual flow withdrawn from the Athabasca River is too low to have a significant impact on aquatic systems, but the main concern lies in water use during low flow periods, typically during the winter months. Developers will likely come under pressure to develop off-site reservoirs to store water for use during these low-flow periods. tabs., figs.

  16. Oil sands mining water use and management

    Energy Technology Data Exchange (ETDEWEB)

    Bender, M.; Long, D.; Fitch, M. [Golder Associates Ltd., Calgary, AB (Canada)

    2010-07-01

    There are currently 4 bitumen mining operations operating along the Athabasca River in northern Alberta. This paper presented details of the water licences, historical water use, present water use, and future plans for water management in relation to oil sands mining operations. The study was based on work currently conducted for the Oil Sands Developers Group (OSDG) and Canadian Association of Petroleum Producers (CAPP), as well as on mine site water balance analyses for proposed mines in the region. Typical mine site water balances were discussed, and water use rates for the mining operations were reviewed. The new Athabasca River water management framework may require that mines provide additional water storage or delayed reclamation of mine areas in order to offset water losses during winter low-flow periods. New regulations may also reduce the requirement for make-up water. The study also noted that release criteria are still being developed for on-site water within closed-loop mine operations. The oil sands industry will need to balance various factors related to water use in the future. 5 refs., 3 figs.

  17. Early diagenetic processes affecting nutrients in the pore waters of Central Indian Ocean cores

    Digital Repository Service at National Institute of Oceanography (India)

    Nath, B.N.; Mudholkar, A.V.

    Pore-water nutrients, nitrite, nitrate, phosphate, silicate, pH and solid-phase organic carbon were analysed for one core from the Arabian Sea and three cores from the manganese nodule area in the Central Indian Ocean Basin. Possible denitrification...

  18. Key parameters and processes affecting the re-establishment of eelgrass in estuaries and coastal water

    DEFF Research Database (Denmark)

    Canal Vergés, Paula

    of field activities and laboratory experiments around seed and seedling survival fitting and success rates were planned. Initially, there were performed pre-screening activities, in a pre-selected study area, Odense fjord (Fyn, Denmark). From the pre-screening basic data on fauna, benthic vegetation...... and sediment trapping. In the last decades seagrass, in general and eelgrass (Zostera marina) in particular, have been heavily reduced, primarily due to a generalized euthrophication of the coastal waters. In Denmark, a numerous efforts on nutrient reduction and improvement on coastal water quality have been...... of the objectives were to gain a further and deeper understanding on eelgrass recolonization processes and to gather all the collected data into a modelling tool which allowing to predict eelgrass reestablishment. Eelgrass re-establishment in Denmark has to be based on seed and seedling success, therefore a series...

  19. Ammonium in thermal waters of Yellowstone National Park: processes affecting speciation and isotope fractionation

    Science.gov (United States)

    Holloway, J.M.; Nordstrom, D.K.; Böhlke, J.K.; McCleskey, R.B.; Ball, J.W.

    2011-01-01

    Dissolved inorganic nitrogen, largely in reduced form (NH4(T)≈NH4(aq)++NH3(aq)o), has been documented in thermal waters throughout Yellowstone National Park, with concentrations ranging from a few micromolar along the Firehole River to millimolar concentrations at Washburn Hot Springs. Indirect evidence from rock nitrogen analyses and previous work on organic compounds associated with Washburn Hot Springs and the Mirror Plateau indicate multiple sources for thermal water NH4(T), including Mesozoic marine sedimentary rocks, Eocene lacustrine deposits, and glacial deposits. A positive correlation between NH4(T) concentration and δ18O of thermal water indicates that boiling is an important mechanism for increasing concentrations of NH4(T) and other solutes in some areas. The isotopic composition of dissolved NH4(T) is highly variable (δ15N = −6‰ to +30‰) and is positively correlated with pH values. In comparison to likely δ15N values of nitrogen source materials (+1‰ to +7‰), high δ15N values in hot springs with pH >5 are attributed to isotope fractionation associated with NH3(aq)o loss by volatilization. NH4(T) in springs with low pH typically is relatively unfractionated, except for some acid springs with negative δ15N values that are attributed to NH3(g)o condensation. NH4(T) concentration and isotopic variations were evident spatially (between springs) and temporally (in individual springs). These variations are likely to be reflected in biomass and sediments associated with the hot springs and outflows. Elevated NH4(T) concentrations can persist for 10s to 1000s of meters in surface waters draining hot spring areas before being completely assimilated or oxidized.

  20. Mineral-Water Interface Processes Affecting Uranium Fate in Contaminated Sediments

    Science.gov (United States)

    Catalano, J. G.

    2011-12-01

    Widespread uranium contamination of soil, sediments, and groundwater systems has resulted from mining activities, nuclear weapon production, and energy generation. The fate and transport of uranium in such systems is strongly affected by geochemical processes occurring at mineral-water interfaces. I will present a summary of the mineral-water interface processes found to affect uranium fate in example contaminated sediments at the U.S. Department of Energy's Hanford sites and in related model systems. Processes occurring under oxic conditions will be the primary focus of this talk as under these conditions uranium is most mobile and thus presents the greatest hazard. Three dominant solid-phase uranium species are observed in contaminated soil and sediments at the Hanford site: uranyl silicates, uranyl phosphates, and uranyl adsorbed to clays and iron oxides. In deep sediments, uranyl silicates are found in microfractures in feldspar grains, likely because slow diffusion in such fractures maintains a high silicate activity. Such silicates are also found in waste-impacted shallow sediments and soil; waste fluids or evaporative processes may have generated the silicate activity needed to produce such phases. Uranyl phosphates are less abundant, occurring primarily in shallow sediments exposed to P-bearing waste fluids. However, remediation approaches under consideration may produce substantial quantities of uranyl phosphates in the future. Adsorbed uranyl is dispersed throughout contaminated soils and shallow sediments and likely has the greatest potential for remobilization. Analogue studies show that precipitation of uranyl phosphates is rapid when such phases are supersaturated and that both homogeneous and heterogeneous nucleation may occur. Specific adsorption of uranyl to minerals is strongly affected by the presence of complexation anions. Carbonate suppresses uranyl adsorption but also forms uranyl-carbonate ternary surface complexes. At conditions below

  1. Streamflow and water-quality conditions including geologic sources and processes affecting selenium loading in the Toll Gate Creek watershed, Aurora, Arapahoe County, Colorado, 2007

    Science.gov (United States)

    Paschke, Suzanne S.; Runkel, Robert L.; Walton-Day, Katherine; Kimball, Briant A.; Schaffrath, Keelin R.

    2013-01-01

    Toll Gate Creek is a perennial stream draining a suburban area in Aurora, Colorado, where selenium concentrations have consistently exceeded the State of Colorado aquatic-life standard for selenium of 4.6 micrograms per liter since the early 2000s. In cooperation with the City of Aurora, Colorado, Utilities Department, a synoptic water-quality study was performed along an 18-kilometer reach of Toll Gate Creek extending from downstream from Quincy Reservoir to the confluence with Sand Creek to develop a detailed understanding of streamflow and concentrations and loads of selenium in Toll Gate Creek. Streamflow and surface-water quality were characterized for summer low-flow conditions (July–August 2007) using four spatially overlapping synoptic-sampling subreaches. Mass-balance methods were applied to the synoptic-sampling and tracer-injection results to estimate streamflow and develop spatial profiles of concentration and load for selenium and other chemical constituents in Toll Gate Creek surface water. Concurrent groundwater sampling determined concentrations of selenium and other chemical constituents in groundwater in areas surrounding the Toll Gate Creek study reaches. Multivariate principal-component analysis was used to group samples and to suggest common sources for dissolved selenium and major ions. Hydrogen and oxygen stable-isotope ratios, groundwater-age interpretations, and chemical analysis of water-soluble paste extractions from core samples are presented, and interpretation of the hydrologic and geochemical data support conclusions regarding geologic sources of selenium and the processes affecting selenium loading in the Toll Gate Creek watershed.

  2. Microwaves energy in curing process of water glass molding sands

    Directory of Open Access Journals (Sweden)

    Granat K.

    2007-01-01

    Full Text Available This work presents the results of investigation of microwave heating on hardening process of water glass molding sands. Essential influence of this heating process on basic properties such as: compression, bending and tensile strength as well as permeability and abrasion resistance has been found. It has been proved, that all investigated sorts of sodium water glass with a module between 2.0 and 3.3 can be used as a binder of molding sands in microwave curing process. It has been found during analysis of research results of sands with 2.5 % water glass addition that they are practically the same as in case of identical molding sands dried for 120 minutes at the temperature of 110°C, used for comparative purposes. Application of microwave curing of molding sands with water glass, however, guarantees reduction of hardening time (from 120 to 4 minutes as well as significant reduction of energy consumption. Attempts of two stage hardening of the investigated water glass molding sands have also been carried out, that is after an initial hardening during a classical CO2 process (identical sands have also been tested for comparison after CO2 blowing process and additional microwave heating. It has been found that application of this kind of treatment for curing sands with 2.5 % sodium water glass content and module from 2.0 up to 3.3 results in the improvement of properties in comparison to classical CO2 process.

  3. Sustainable water management in Alberta's oil sands

    Energy Technology Data Exchange (ETDEWEB)

    Byers, Bill; Usher, Robyn; Roach, Andrea [CH2M HILL, Englewood, CO (United States); Lambert, Gord; Kotecha, Prit [Suncor Energy Inc., Calgary (Canada)

    2012-07-01

    The Canadian Association of Petroleum Producers forecast published in 2011 predicts that oil production from oil sands will increase by 50% in the next 3 years and double by 2020. This rate of growth will result in significant pressure on water resources; water use per barrel of oil sands production is comparable to other energy resources - about 2.5 barrels of fresh water per barrel of oil produced are used by mining operations and 0.5 barrels by in-situ operations. Suncor Energy Inc. (Suncor) was the first company to develop the oil sands in northern Alberta and holds one of the largest oil sands positions in Canada. In 2010, Suncor announced plans to increase production to more than 1 million barrels of oil equivalent per day by 2020, which it plans to achieve through oil sands production growth of approximately 10% per year. Because water supply and potential impacts to water quality are critical to its future growth, in 2010-2011 Suncor conducted a risk assessment to identify water-related business risks related to its northern Alberta operations. The assessment identified more than 20 high level business risks in strategic water risk areas including water supply, water reuse, storm water management, groundwater, waste management and river water return. The risk assessment results prompted development of a strategic roadmap to guide water stewardship across Suncor's regional operations. The roadmap describes goals, objectives, and specific activities for each of six key water risk areas, and informs prioritization and selection of prospective water management activities. Suncor is not only exploring water within its own boundaries, but is also collaborating with other oil sands producers to explore ways of integrating its water systems through industry consortia; Suncor is a member of the Oil Sands Leadership Initiative and of the recently formed Canadian Oil Sands Innovation Alliance, among others. (author)

  4. Dynamic response of dry and water-saturated sand systems

    Science.gov (United States)

    LaJeunesse, J. W.; Hankin, M.; Kennedy, G. B.; Spaulding, D. K.; Schumaker, M. G.; Neel, C. H.; Borg, J. P.; Stewart, S. T.; Thadhani, N. N.

    2017-07-01

    The effect of grain size and moisture content on the dynamic macroscopic response of granular geological materials was explored by performing uniaxial planar impact experiments on high purity, Oklahoma #1, sand samples composed of either fine (75-150 μm) or coarse (425-500 μm) grain sizes in either dry or fully water-saturated conditions. Oklahoma #1 sand was chosen for its smooth, quasi-spherical grain shapes, narrow grain size distributions, and nearly pure SiO2 composition (99.8 wt. %). The water-saturated samples were completely saturated ensuring a two-phase mixture with roughly 65% sand and 35% water. Sand samples were dynamically loaded to pressures between 1 and 11 GPa. Three-dimensional meso-scale simulations using an Eulerian hydrocode, CTH, were created to model the response of each sand sample. Multi-phase equations of state were used for both silicon dioxide, which comprised individual sand grains, and water, which surrounded individual grains. Particle velocity profiles measured from the rear surface of the sand, both experimentally and computationally, reveal that fine grain samples have steeper rise characteristics than coarse grain samples and water-saturated samples have an overall much stiffer response than dry samples. The experimentally determined particle velocity vs. shock velocity response of dry sand was linear over this pressure range, with little difference between the two grain sizes investigated. The experimental response for the water saturated sand exhibited a piecewise continuous response with a transition region between particle velocities of 0.6 km s-1 and 0.8 km s-1 and a pressure of 4.5-6 GPa. Hypotheses for the cause of this transition region are drawn based on results of the meso-scale simulations.

  5. Locomotory transition from water to sand and its effects on undulatory kinematics in sand lances (Ammodytidae).

    Science.gov (United States)

    Gidmark, Nicholas J; Strother, James A; Horton, Jaquan M; Summers, Adam P; Brainerd, Elizabeth L

    2011-02-15

    Sand lances, fishes in the genus Ammodytes, exhibit a peculiar burrowing behavior in which they appear to swim rapidly into the substrate. They use posteriorly propagated undulations of the body to move in both water, a Newtonian fluid, and in sand, a non-Newtonian, granular substrate. In typical aquatic limbless locomotion, undulations of the body push against water, which flows because it is incapable of supporting the static stresses exerted by the animal, thus the undulations move in world space (slipping wave locomotion). In typical terrestrial limbless locomotion, these undulations push against substrate irregularities and move relatively little in world space (non-slipping wave locomotion). We used standard and X-ray video to determine the roles of slipping wave and non-slipping wave locomotion during burrowing in sand lances. We find that sand lances in water use slipping wave locomotion, similar to most aquatic undulators, but switch to non-slipping waves once they burrow. We identify a progression of three stages in the burrowing process: first, aquatic undulations similar to typical anguilliform locomotion (but without head yaw) push the head into the sand; second, more pronounced undulations of the aquatic portion of the body push most of the animal below ground; third, the remaining above-ground portion of the body ceases undulation and the subterranean portion takes over, transitioning to non-slipping wave locomotion. We find no evidence that sand lances use their body motions to fluidize the sand. Instead, as soon as enough of the body is underground, they undergo a kinematic shift and locomote like terrestrial limbless vertebrates.

  6. A Simple Slow-Sand Filter for Drinking Water Purification

    Directory of Open Access Journals (Sweden)

    K. O. Yusuf

    2017-04-01

    Full Text Available Water-borne diseases are commonly encountered when pathogen-contaminated water is consumed. In rural areas, water is usually obtained from ponds, open shallow wells, streams and rain water during rainy season. Rain water is often contaminated by pathogens due to unhygienic of physical and chemical conditions of the roofs thereby making it unsafe for consumption. A simple slow sand filter mechanism was designed and fabricated for purification of water in rural areas where electricity is not available to power water purification devices. Rain water samples were collected from aluminum roof, galvanized roof and thatched roof. The waters samples were allowed to flow through the slow sand filter. The values of turbidity, total dissolved solids, calcium, nitrite, faecal coliform and total coliform from unfiltered water through thatched roof were 0.92 NTU, 27.23 mg/l, 6 mg/l, 0.16 mg/l, 5cfu/100ml and 6.0 cfu/100ml, respectively while the corresponding values for slow sand filter from thatched roof were 0.01 NTU, 0.23 mg/l, 2.5 mg/l, 0.1 mg/l, 0 cfu/100ml and 0 cfu/100ml, respectively. The values of turbidity, total dissolved solid, nitrite, calcium, faecal coliform and total coliform from unfiltered water for aluminum roof were 0.82 NTU, 23.68 mg/l, 2.70 mg/l, 1.0 mg/l, 4 cfu/100ml and 4cfu/100ml, respectively while the corresponding values for slow sand filter were 0.01 NTU, 0.16 mg/l, 0.57 mg/l, 0.2 mg/l, 0 cfu/100ml and 0 cfu/100ml, respectively. The values obtained for galvanized roof were also satisfactory. The slow sand filter is recommended for used in rural areas for water purification to prevent risk of water-borne diseases.

  7. Fingering Instability in a Water-Sand Mixture

    CERN Document Server

    Lange, A; Scherer, M A; Engel, A; Rehberg, I

    1997-01-01

    The temporal evolution of a water-sand interface driven by gravity is experimentally investigated. By means of a Fourier analysis of the evolving interface the growth rates are determined for the different modes appearing in the developing front. To model the observed behavior we apply the idea of the Rayleigh-Taylor instability for two stratified fluids. Carrying out a linear stability analysis we calculate the growth rates from the corresponding dispersion relations for finite and infinite cell sizes. Taking into account the uncertainty in the viscosity measurements for sand dispersed in water, the theoretical results catch the essence of the experiment but also demonstrate the limitations of this approach.

  8. Successful strategies for water management in the oil sands region

    Energy Technology Data Exchange (ETDEWEB)

    Smith, J.; Baker, M. [Shell Canada Ltd., Calgary, AB (Canada). Oil Sands Division

    2004-07-01

    Since large quantities of water are required for oil sand mining, water withdrawals from rivers located near oil sand mining facilities may increase. This paper referred to the water-based extraction process at the Muskeg River Mine operated by Albian Sands Energy. Although water is recycled and reused as much as possible, drought conditions in Alberta have raised concerns about the potential increased rates of water withdrawal during seasonal low flow periods. Measures have been taken to manage river withdrawals and ensure sustainability of aquatic resources. A committee has been established under the Cumulative Environmental Management Association (CEMA) to develop a management system for the Athabasca River. The committee includes stakeholders from federal and provincial governments, First Nations, non-government groups and industry. This paper describes the challenges facing oil sands developers in the region with particular emphasis on the role that the newly developed management system called 'Instream Flow Needs', will have on the cumulative water withdrawal from the Athabasca River. 9 figs.

  9. White Sands Missile Range 2011 Drinking Water Quality Report

    Science.gov (United States)

    2012-01-01

    acerca de su agua potable . Haga que alguien lo traduzca para usted, o hable con alguien que lo entienda. Main Post White Sands Missile Range 2011...standards. What is This Water Quality Report? Este informe contiene informacion importante acerca de su agua potable . Haga que alguien lo traduzca

  10. Effects of oil sands waste water on the wood frog (rana sylvatica)

    Energy Technology Data Exchange (ETDEWEB)

    Hersikorn, B.; Smits, J.E. [Saskatchewan Univ., Regina, SK (Canada)

    2007-07-01

    The sustainability of various reclamation strategies can be determined by the growth and health of indigenous amphibians (Wood Frogs). This paper referred to the large quantities of tailings water that are generated by oil sand extraction activities. It presented the results of a study that was conducted in the spring and summer of 2006 and 2007 on reclaimed formation wetlands comprising tailings water. The objective was to understand the impact of these wetlands on native amphibians. Frogs were exposed to wetlands containing oil sands process affected water (OSPW) and reference water (no OSPW). Six experimental trenches were made at one site in the first year. Each trench had 3 enclosures with 50 tadpoles. In the second year, there were 13 sites, including 6 reference and 7 OSPW affected sites, which were classified as old (more than 8 yrs) or young (less than 7 yrs). Four enclosures, with 50 tadpoles each, were placed in each wetland. The study involved the evaluation of growth rate, survival, time to metamorphosis, thyroid hormone concentrations, liver EROD activity, and tissue retinol concentrations. In addition, stable isotopes were used to track carbon flow from primary production plants, through the food chain, to tadpoles and frogs which represent intermediate and higher trophic levels in reclaimed wetlands.

  11. Oil sands water withdrawal challenges and the Athabasca River

    Energy Technology Data Exchange (ETDEWEB)

    Smith, J.; Baker, M. [Shell Canada Ltd., Calgary, AB (Canada). Calgary Research Centre

    2003-07-01

    Drought conditions in Alberta have raised concerns regarding water withdrawal from the Athabasca River for oil sands development projects in the Regional Municipality of Wood Buffalo in Northeastern Alberta. In particular, concerns have been raised about the potential increased rates of water withdrawal during seasonal low flow periods. A committee has been established under the Cumulative Environmental Management Association (CEMA) to develop a management system for the Athabasca River. The committee includes stakeholders from federal and provincial governments, First Nations, non-government groups and industry. This paper describes the challenges facing oil sands developers in the region with particular emphasis on the role that the newly developed management system called 'Instream Flow Needs', will have on the cumulative water withdrawal from the Athabasca River. tabs., figs.

  12. Characteristics of streams and aquifers and processes affecting the salinity of water in the upper Colorado River basin, Texas

    Science.gov (United States)

    Slade, R.M.; Buszka, P.M.

    1994-01-01

    The upper Colorado River and some of its tributaries between Lake J.B. Thomas and O.H. Ivie Reservoir contain saline water (defined as water having dissolved-solids concentrations greater than 1,000 milligrams per liter). Dissolved-solids loads at nine streamflow water-quality stations increased from 1986 to 1988. The largest increases were in Beals Creek and in the Colorado River downstream from Beals Creek as a result of outflow of saline water from Natural Dam Salt Lake. The outflow contained 654,000 tons of dissolved solids and had a mean dissolved-solids concentration of 7,900 milligrams per liter. This amount represents about 51 percent of the dissolved-solids load to E.V. Spence Reservoir during 1986-88.

  13. Catchment process affecting drinking water quality, including the significance of rainfall events, using factor analysis and event mean concentrations.

    Science.gov (United States)

    Cinque, Kathy; Jayasuriya, Niranjali

    2010-12-01

    To ensure the protection of drinking water an understanding of the catchment processes which can affect water quality is important as it enables targeted catchment management actions to be implemented. In this study factor analysis (FA) and comparing event mean concentrations (EMCs) with baseline values were techniques used to asses the relationships between water quality parameters and linking those parameters to processes within an agricultural drinking water catchment. FA found that 55% of the variance in the water quality data could be explained by the first factor, which was dominated by parameters usually associated with erosion. Inclusion of pathogenic indicators in an additional FA showed that Enterococcus and Clostridium perfringens (C. perfringens) were also related to the erosion factor. Analysis of the EMCs found that most parameters were significantly higher during periods of rainfall runoff. This study shows that the most dominant processes in an agricultural catchment are surface runoff and erosion. It also shows that it is these processes which mobilise pathogenic indicators and are therefore most likely to influence the transport of pathogens. Catchment management efforts need to focus on reducing the effect of these processes on water quality.

  14. Virus removal vs. subsurface water velocity during slow sand filtration.

    Science.gov (United States)

    Dizer, Halim; Brackmann, Bernhard; Rahman, M Azizur; Szewzyk, Regine; Sprenger, Christoph; Holzbecher, Ekkehard; López-Pila, Juan M

    2015-06-01

    In an attempt to obtain a conservative estimate of virus removal during slow sand and river bank filtration, a somatic phage was isolated with slow decay and poor adsorption to coarse sand. We continuously fed a phage suspension to a 7-m infiltration path and measured the phage removal. In a second set of experiments, we fed the phage suspension to 1-m long columns run at different pore water velocities. Using the data obtained, a mathematical model was constructed describing removal vs. pore water velocity (PWV), assuming different statistical distributions of the adsorption coefficient λ. The bimodal distribution best fit the results for PWVs higher than 1 m/d. It predicted a removal of approximately 4 log10 after 50 days infiltration at 1 m/d. At PWVs below 1 m/d the model underestimated removal. Sand-bound phages dissociated slowly into the liquid phase, with a detachment constant kdet of 2.6 × 10⁻⁵. This low kdet suggests that river bank filtration plants should be intermittently operated when viral overload is suspected, e.g. during flooding events or at high water-marks in rivers, in order for viruses to become soil-associated during the periods of standstill. Resuming filtration will allow only a very slow virus release from the soil.

  15. Groundwater and surface-water interaction, water quality, and processes affecting loads of dissolved solids, selenium, and uranium in Fountain Creek near Pueblo, Colorado, 2012–2014

    Science.gov (United States)

    Arnold, L. Rick; Ortiz, Roderick F.; Brown, Christopher R.; Watts, Kenneth R.

    2016-11-28

    In 2012, the U.S. Geological Survey, in cooperation with the Arkansas River Basin Regional Resource Planning Group, initiated a study of groundwater and surface-water interaction, water quality, and loading of dissolved solids, selenium, and uranium to Fountain Creek near Pueblo, Colorado, to improve understanding of sources and processes affecting loading of these constituents to streams in the Arkansas River Basin. Fourteen monitoring wells were installed in a series of three transects across Fountain Creek near Pueblo, and temporary streamgages were established at each transect to facilitate data collection for the study. Groundwater and surface-water interaction was characterized by using hydrogeologic mapping, groundwater and stream-surface levels, groundwater and stream temperatures, vertical hydraulic-head gradients and ratios of oxygen and hydrogen isotopes in the hyporheic zone, and streamflow mass-balance measurements. Water quality was characterized by collecting periodic samples from groundwater, surface water, and the hyporheic zone for analysis of dissolved solids, selenium, uranium, and other selected constituents and by evaluating the oxidation-reduction condition for each groundwater sample under different hydrologic conditions throughout the study period. Groundwater loads to Fountain Creek and in-stream loads were computed for the study area, and processes affecting loads of dissolved solids, selenium, and uranium were evaluated on the basis of geology, geochemical conditions, land and water use, and evapoconcentration.During the study period, the groundwater-flow system generally contributed flow to Fountain Creek and its hyporheic zone (as a single system) except for the reach between the north and middle transects. However, the direction of flow between the stream, the hyporheic zone, and the near-stream aquifer was variable in response to streamflow and stage. During periods of low streamflow, Fountain Creek generally gained flow from

  16. Numerical Simulations of Vertical Water Redistribution in Sand

    Science.gov (United States)

    Abhishek, A.

    2016-12-01

    Moisture redistribution process in porous media has a wide range of practical applications in petroleum industry, agriculture engineering, hydrology and carbon/CO2 sequestration. Recently, a vertical water redistribution experiment was designed. A thin column with dimensions of 50 (height) by 1.2 cm (inner diameter) was employed. Five water tensiometers were mounted along the column at distances of 1, 13, 25, 37 and 49 cm from the top. Two air tensiometers were mounted at 15 and 35 cm from the top to measure air pressure. The column was packed with saturated medium sand and was set up vertically. The bottom of the column was set open to the air to allow the sand to drain gradually under gravity. Once the flow completely ceased and equilibrium was reached, the column was reversed to let moisture in the sand redistribute. During both free drainage and redistribution processes, saturation was measured by gamma transmission method, and water and air pressure were measured by tensiometers. Numerical simulations were used to estimate saturation distribution over the whole column and the duration of experiments. We used both 1D and 2D models based on Richards equation to simulate this vertical redistribution process. Both COMSOL and HYDRUS-1D were used to solve 1D model, while COMSOL was employed to solve 2D model. In 1D simulations, equilibrium time was found to increase linearly during free drainage process, proportional to the length of the column. It was 1.4 days for the length of 50 cm, which is employed in experiments. In 2D simulations, water saturation profiles were non-uniform along the width of the domain at earlier time steps, while they become almost uniform when equilibrium was reached. The simulated results are compared with experimental results.

  17. Water repellency of clay, sand and organic soils in Finland

    Directory of Open Access Journals (Sweden)

    K. RASA

    2008-12-01

    Full Text Available Water repellency (WR delays soil wetting process, increases preferential flow and may give rise to surface runoff and consequent erosion. WR is commonly recognized in the soils of warm and temperate climates. To explore the occurrence of WR in soils in Finland, soil R index was studied on 12 sites of different soil types. The effects of soil management practice, vegetation age, soil moisture and drying temperature on WR were studied by a mini-infiltrometer with samples from depths of 0-5 and 5-10 cm. All studied sites exhibited WR (R index >1.95 at the time of sampling. WR increased as follows: sand (R = 1.8-5.0 < clay (R = 2.4-10.3 < organic (R = 7.9-undefined. At clay and sand, WR was generally higher at the soil surface and at the older sites (14 yr., where organic matter is accumulated. Below 41 vol. % water content these mineral soils were water repellent whereas organic soil exhibited WR even at saturation. These results show that soil WR also reduces water infiltration at the prevalent field moisture regime in the soils of boreal climate. The ageing of vegetation increases WR and on the other hand, cultivation reduces or hinders the development of WR.;

  18. Arsenate removal from water using sand--red mud columns.

    Science.gov (United States)

    Genç-Fuhrman, Hülya; Bregnhøj, Henrik; McConchie, David

    2005-08-01

    This study describes experiments in which sorption filters, filled with chemically modified red mud (Bauxsol) or activated Bauxsol (AB) coated sand, are used to remove As(V) (arsenate) from water. Bauxsol-coated sand (BCS) and AB-coated sand (ABCS) are prepared by mixing Bauxsol or AB with wet sand and drying. Samples of the BCS and ABCS are also used in batch experiments to obtain isotherm data. The observed adsorption data fit the Langmuir model well, with adsorption maxima of 3.32 and 1.64 mgg(-1) at pH values of 4.5 and 7.1, respectively for BCS; and of 2.14 mgg(-1) for ABCS at a pH of 7.1. Test results show that higher arsenate adsorption capacities can be achieved for both BCS and ABCS when using the columns compared to results for batch experiments; the difference is greater for BCS. Additional batch tests, carried out for 21 days using BCS to explain the observed discrepancy, show that the equilibrium time previously used in batch experiments was too short because adsorption continued for at least 21 days and reached 87% after 21 days compared to only 35% obtained after 4h. Fixed bed column tests, used to investigate the effects of flow rate and initial arsenate concentration indicate that the process is sensitive to both parameters, with lower flow rates (longer effective residence times in the columns) and initial arsenate concentrations providing better column performance. An examination of the combined effect of potential competing anions (i.e. silicate, phosphate, sulphate and bicarbonate) on the column performance showed that the presence of these anions in tap water slightly decreases arsenate removal. Each breakthrough curve is compared to the Thomas model, and it is found that the model may be applied to estimate the arsenate sorption capacity in columns filled with BCS and ABCS. The data obtained from both batch and column studies indicate that BCS and ABCS filtration could be effectively used to remove arsenate from water, with the latter being

  19. Geology, Surficial - SAND_ILITH_IN: Total Thickness of Sand and Gravel in Indiana, Derived from the iLITH Water-Well Database (Indiana Geological Survey, Grid)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — SAND_ILITH_IN is a grid that shows total thickness of sand, as derived from logs of water wells in the state of Indiana. (It presents the same data as shown in a...

  20. Limited effectiveness of household sand filters for removal of arsenic from well water in North Vietnam.

    Science.gov (United States)

    Ilmiawati, Cimi; Thang, Nguyen Dinh; Iida, Machiko; Maeda, Masao; Ohnuma, Shoko; Yajima, Ichiro; Ohgami, Nobutaka; Oshino, Reina; Al Hossain, M M Aeorangajeb; Ninomiya, Hiromasa; Kato, Masashi

    2016-12-01

    Since well water utilized for domestic purposes in the Red River Delta of North Vietnam has been reported to be polluted by arsenic, barium, iron, and manganese, household sand filters consisting of various components are used. Information regarding the effectiveness of various sand filters for removal of the four toxic elements in well water is limited. In this study, arsenic levels in 13/20 of well water samples and 1/7 of tap water samples exceeded World Health Organization (WHO) health-based guideline value for drinking water. Moreover, 2/20, 6/20, and 4/20 of well water samples had levels exceeding the present and previous guideline levels for barium, iron, and manganese, respectively. Levels of iron and manganese, but not arsenic, in well water treated by sand filters were lower than those in untreated water, although previous studies showed that sand filters removed all of those elements from water. A low ratio of iron/arsenic in well water may not be sufficient for efficient removal of arsenic from household sand filters. The levels of barium in well water treated by sand filters, especially a filter composed of sand and charcoal, were significantly lower than those in untreated water. Thus, we demonstrated characteristics of sand filters in North Vietnam.

  1. Processes of microbial pesticide degradation in rapid sand filters for treatment of drinking water

    DEFF Research Database (Denmark)

    Hedegaard, Mathilde Jørgensen; Albrechtsen, Hans-Jørgen

    concentrations of 0.04-2.4 μg/L. The pesticides were removed from the water in microcosms with filter sand from all three investigated sand filters. Within the experimental periode of six to 13 days, 65-85% of the bentazone, 86-93% of the glyphosate, 97-99% of the p-nitrophenol was removed from the water phase......Aerobic rapid sand filters for treatment of groundwater at waterworks were investigated for the ability to remove pesticides. The potential, kinetics and mechanisms of microbial pesticide removal was investigated in microcosms consisting of filter sand, treated water and pesticides in initial...

  2. Production of high quality water for oil sands application

    Energy Technology Data Exchange (ETDEWEB)

    Beaudette-Hodsman, C.; Macleod, B. [Pall Corp., Mississauga, ON (Canada); Venkatadri, R. [Pall Corp., East Hills, NY (United States)

    2008-10-15

    This paper described a pressurized microfiltration membrane system installed at an oil sands extraction site in Alberta. The system was designed to complement a reverse osmosis (RO) system installed at the site to produce the high quality feed water required by the system's boilers. Groundwater in the region exhibited moderate total suspended solids and high alkalinity and hardness levels, and the RO system required feed water with a silt density index of 3 or less. The conventional pretreatment system used at the site was slowing down production due to the severe fouling of the RO membranes. The new microfiltration system contained an automated PVDF hollow fiber microfiltration membrane system contained in a trailer. Suspended particles and bacteria were captured within the filter, and permeate was sent to the RO unit. Within 6 hours of being installed, the unit was producing water with SDI values in the range of 1.0 to 2.5. It was concluded that the microfiltration system performed reliably regardless of wide variations in feed water quality and flow rates. 3 refs., 1 tab., 8 figs.

  3. Experimental Investigation of Evaporation and Drainage in Wettable and Water-Repellent Sands

    Directory of Open Access Journals (Sweden)

    Dae Hyun Kim

    2015-05-01

    Full Text Available This study presents experimental results on evaporation and drainage in both wettable and water-repellent sands whose surface wettability was artificially modified by silanization. The 2D optical and 3D X-ray computed tomographic imaging was performed during evaporation and the water retention during cyclic drainage and infiltration was measured to assess effects of wettability and initial wetting conditions. The evaporation gradually induces its front at the early stage advance regardless of the wettability and sand types, while its rate becomes higher in water-repellent Ottawa sand than the wettable one. Jumunjin sand which has a smaller particle size and irregular particle shape than Ottawa sand exhibits a similar evaporation rate independent of wettability. Water-repellent sand can facilitate the evaporation when both wettable and water-repellent sands are naturally in contact with each other. The 3D X-ray imaging reveals that the hydraulically connected water films in wettable sands facilitate the propagation of the evaporation front into the soil such that the drying front deeply advances into the soil. For cyclic drainage-infiltration testing, the evolution of water retention is similar in both wettable and water-repellent sands when both are initially wet. However, when conditions are initially dry, water-repellent sands exhibit low residual saturation values. The experimental observations made from this study propose that the surface wettability may not be a sole factor while the degree of water-repellency, type of sands, and initial wetting condition are predominant when assessing evaporation and drainage behaviors.

  4. Effect of water content on the water repellency for hydrophobized sands

    Science.gov (United States)

    Subedi, S.; Kawamoto, K.; Kuroda, T.; Moldrup, P.; Komatsu, T.

    2011-12-01

    Alternative earthen covers such as capillary barriers (CBs) and evapotranspirative covers are recognized as useful technical and low-cost solutions for limiting water infiltration and controlling seepage flow at solid waste landfills in semi-arid and arid regions. However, their application to the landfills at wet regions seems to be matter of concern due to loss of their impending capability under high precipitation. One of the possible techniques to enhance the impermeable properties of CBs is to alter soil grain surfaces to be water-repellent by mixing/coating hydrophobic agents (HAs). In order to examine a potential use of model sands hydrophobized with locally available and environmental-friendly HAs such as oleic acid (OA) and stearic acid (SA) for hydrophobic CBs. In the present study, we first characterized the effect of water content on the degree of water repellency (WR) for hydrophobized sands and volcanic ash soil at different depth. Secondly, the time dependency of the contact angle in hydrophobized sands and volcanic ash soils at different water content was evaluated. Further, the effects of hydrophobic organic matter contents on the WR of hydrophobized sands were investigated by horizontal infiltration test. We investigated the degree of WR as functions of volumetric water content (θ) of a volcanic ash soil samples from different depth and water adjusted hydrophobized sand samples with different ratio of HAs by using sessile drop method (SDM). The initial contact angle (αi) measured from SDM decreased gradually with increasing water content in OA and SA coated samples. Measured αi values for volcanic ash soils increased with increasing water content and reached a peak values of 111.7o at θ= 0.325 cm3 cm-3, where-after αi gradually decreased. Each test sample exhibited sharp decrease in contact angle with time at higher water content. Sorptivity values for oleic acid coated samples decreased with increasing HA content and reached the minimum

  5. Densities and antimicrobial resistance of Escherichia coli isolated from marine waters and beach sands.

    Science.gov (United States)

    Andrade, Vanessa da Costa; Zampieri, Bruna Del Busso; Ballesteros, Eliete Rodrigues; Pinto, Aline Bartelochi; de Oliveira, Ana Julia Fernandes Cardoso

    2015-06-01

    Bacterial resistance is a rising problem all over the world. Many studies have showed that beach sands can contain higher concentration of microorganisms and represent a risk to public health. This paper aims to evaluate the densities and resistance to antimicrobials of Escherichia coli strains, isolated from seawater and samples. The hypothesis is that microorganisms show higher densities in contaminated beach sands and more antimicrobial resistance than the water column. Density, distribution, and antimicrobial resistance of bacteria E. coli were evaluate in seawater and sands from two recreational beaches with different levels of pollution. At the beach with higher degree of pollution (Gonzaguinha), water samples presented the highest densities of E. coli; however, higher frequency of resistant strains was observe in wet sand (71.9 %). Resistance to a larger number of antimicrobial groups was observe in water (betalactamics, aminoglycosides, macrolides, rifampicins, and tetracyclines) and sand (betagalactamics and aminoglycosids). In water samples, highest frequencies of resistance were obtain against ampicilin (22.5 %), streptomycin (15.0 %), and rifampicin (15.0 %), while in sand, the highest frequencies were observe in relation to ampicilin (36.25 %) and streptomycin (23.52 %). At the less polluted beach, Ilha Porchat, highest densities of E. coli and higher frequency of resistance were obtain in wet and dry sand (53.7 and 53.8 %, respectively) compared to water (50 %). Antimicrobial resistance in strains isolated from water and sand only occurred against betalactamics (ampicilin and amoxicilin plus clavulanic acid). The frequency and variability of bacterial resistance to antimicrobials in marine recreational waters and sands were related to the degree of fecal contamination in this environment. These results show that water and sands from beaches with a high index of fecal contamination of human origin may be potential sources of contamination by pathogens

  6. Effect of hardening methods of moulding sands with water glass on structure of bonding bridges

    OpenAIRE

    Stachowicz, M.; K. Granat; Nowak, D.

    2010-01-01

    Research on influence of hardening methods on structure of bonding bridges in moulding sands with sodium water glass is presented.Moulding sands with addition of 2.5 % of binder with molar module 2.0 were hardened with CO2 and dried in traditional way or hardenedwith microwaves. It was proved that the hardening method affects structure of bonding bridges, correlating with properties of the hardened moulding sands. It was found that strength of the moulding sands hardened with microwaves for 4...

  7. Effect of hardening methods of moulding sands with water glass on structure of bonding bridges

    Directory of Open Access Journals (Sweden)

    M. Stachowicz

    2010-07-01

    Full Text Available Research on influence of hardening methods on structure of bonding bridges in moulding sands with sodium water glass is presented.Moulding sands with addition of 2.5 % of binder with molar module 2.0 were hardened with CO2 and dried in traditional way or hardenedwith microwaves. It was proved that the hardening method affects structure of bonding bridges, correlating with properties of the hardened moulding sands. It was found that strength of the moulding sands hardened with microwaves for 4 min is very close to that measured after traditional drying at 110 °C for 120 min. So, application of microwave hardening ensures significant shortening of the process time to the value comparable with CO2 hardening but guaranteeing over 10-fold increase of mechanical properties. Analysis of SEM images of hardened moulding sands permitted explaining differences in quality parameters of moulding sands by connecting them with structure of the created bonding bridges.

  8. In vitro evaluation of the toxic effects and endocrine disrupting potential of oil sands processed water and naphthenic acids

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, X.; Wiseman, S.; Higley, E.; Jones, P.D.; Hecker, M.; Giesy, J.P. [Saskatchewan Univ., Saskatoon, SK (Canada); Gamel El Din, M.; Martin, J.W. [Alberta Univ., Edmonton, AB (Canada)

    2009-07-01

    Naphthenic acids (NAs) are the primary toxic constituents of oil sands process-affected waters (OSPW). This presentation reported on a series of in vitro studies that were initiated to evaluate potential endocrine modulating effects of OSPW and their constituent NAs. The H295R steroidogenesis bioassay was used to examine the impact of OSPW and NA on 52 steroidogenesis. In particular, dose-response and time course studies were conducted to evaluate the impact of OSPW and NAs on testosterone and estradiol production. Aromatase activity and transcript abundance of the key 11 steroidogenic enzymes were also quantified to complement analysis of hormone levels. The MVLN trans-activation assay was used to test the estrogenicity/anti-estrogenicity of OSPW and NAs. In vitro cell viability and apoptosis (live-dead) caused by OSPW and NAs was quantified by the MTS reduction and caspase-3/7 activity in H295R and MVLN cells.

  9. The influence of microwave curing time and water glass kind on the properties of molding sands

    Directory of Open Access Journals (Sweden)

    K. Granat

    2007-12-01

    Full Text Available This work presents results of research on the influence of microwave heating time on the process of hardening of water glass molding sands. Essential influence of this drying process on basic properties such as: compression, bending and tensile strength as well as permeability and wear resistance, has been found. It has been proved, that all the investigated sorts of sodium water glass could be used as binding material of molding sands intended for curing with the microwave process heating. It has been found, while analyzing the results of property studies of microwave heated molding sands with 2.5% addition of water glass, that all available on the market kinds of this binding agent (including the most frequently used in foundry 145 and 149 kinds after microwave heating guarantee very good compression, bending and tensile strength as well as permeability and wear resistance. Moreover, it has been determined that the optimal curing time of molding sands containing various kinds of water glass is 240 seconds. After this time, all basic properties of molding sands are stable. The use of microwave curing of water glass molding sands results in a significant decrease of hardening process time, full stabilization of molding sands as well as much lower energy consumption.

  10. Granulation of After Reclamation Dusts from the Mixed Sands Technology: Water Glass – Resolit

    Directory of Open Access Journals (Sweden)

    J. Kamińska

    2013-04-01

    Full Text Available A technology of sands with water glass hardened by liquid esters is a cheap and ecologic method of producing moulding sands. Due to these advantages, this technology is still very important in several foundry plants for production of heavy iron and steel castings. Reclamation of the mixed moulding and core sands generates significant amounts of dusts, which require further treatments for their reuse. The results of investigations of a pressureless granulation of dusts generated in the dry mechanical reclamation process of the mixture consisting in app. 90 % of moulding sands from the Floster S technology and in 10 % of core sands with phenolic resin resol type, are presented in the hereby paper. Investigations were aimed at obtaining granulates of the determined dimensional and strength parameters. Granules were formed from the mixture of dusts consisting of 75 mass% of dusts after the reclamation of sands mixture and of 25 mass% of dusts from bentonite sands processing plant. Wetted dusts from bentonite sands were used as a binding agent allowing the granulation of after reclamation dusts originated from the mixed sands technology.

  11. A new ester hardener for moulding sands with water glass having slower activity

    Directory of Open Access Journals (Sweden)

    K. Major-Gabryś

    2009-10-01

    Full Text Available The article takes into consideration the researches concerning inputting the new hardener to moulding sands with water glass, carried out in ester technology. Investigations are continuation of works connected to hardener based on carbonic acid’s esters, that significantly upgrades the ability of these moulding sands to mechanical reclamation. Its’ nuisance is short vitality. This is why, new investigations were taken to elaborate another hardener keeping the positive characteristics of the previous one and allowing the wider usage of technologies of loose self-hardened moulding sands with water glass.

  12. Movement of coliform bacteria and nutrients in ground water flowing through basalt and sand aquifers.

    Science.gov (United States)

    Entry, J A; Farmer, N

    2001-01-01

    Large-scale deposition of animal manure can result in contamination of surface and ground water and in potential transfer of disease-causing enteric bacteria to animals or humans. We measured total coliform bacteria (TC), fecal coliform bacteria (FC), NO3, NH4, total P, and PO4 in ground water flowing from basalt and sand aquifers, in wells into basalt and sand aquifers, in irrigation water, and in river water. Samples were collected monthly for 1 yr. Total coliform and FC numbers were always higher in irrigation water than in ground water, indicating that soil and sediment filtered most of these bacteria before they entered the aquifers. Total coliform and FC numbers in ground water were generally higher in the faster flowing basalt aquifer than in the sand aquifer, indicating that the slower flow and finer grain size may filter more TC and FC bacteria from water. At least one coliform bacterium/100 mL of water was found in ground water from both basalt and sand aquifers, indicating that ground water pumped from these aquifers is not necessarily safe for human consumption according to the American Public Health Association and the USEPA. The NO3 concentrations were usually higher in water flowing from the sand aquifer than in water flowing from the basalt aquifer or in perched water tables in the basalt aquifer. The PO4 concentrations were usually higher in water flowing from the basalt aquifer than in water flowing from the sand aquifer. The main concern is fecal contamination of these aquifers and health consequences that may arise from human consumption.

  13. Influence of wet activation of used inorganic binder on cyclically refreshed water glass moulding sands hardened by microwaves

    OpenAIRE

    Mateusz Stachowicz; Kazimierz Granat

    2016-01-01

    The paper presents the research results of using an innovative method to reclaim the waste moulding sands containing water glass. Two of the examined processes are connected with "dry" or "wet" activation of inorganic binder in waste moulding sand mixtures physically hardened by microwave radiation. The sand mixtures consisting of high-silica sand and water-glass with average molar module 2.5, were subjected to the following cyclical process: mixing the components, compacting, microwave heati...

  14. Submerged Pond Sand Filter-A Novel Approach to Rural Water Supply

    DEFF Research Database (Denmark)

    Øhlenschlæger, Mia; Christensen, Sarah Christine Boesgaard; Bregnhøj, Henrik

    2016-01-01

    This study describes the new design and function of a modified version of a traditional slow sand filter. The Submerged Pond Sand Filter is built inside a pond and has a vertical as well as a horizontal flow of water through a sloped filter opening. The filter provides treated drinking water......-depleted area, where only surface water was available. Furthermore, it is a sustainable treatment method due to low maintenance requirements....... to a rural Indian village. The filter has functioned with minimal maintenance for five years without being subject to the typical scraping off and changing of sand as needed in traditional slow sand filters every few months. This five-year study showed bacterial removal efficiency of 97% on average...

  15. Contribution of sand-associated enterococci to dry weather water quality.

    Science.gov (United States)

    Halliday, Elizabeth; Ralston, David K; Gast, Rebecca J

    2015-01-06

    Culturable enterococci and a suite of environmental variables were collected during a predominantly dry summer at a beach impacted by nonpoint source pollution. These data were used to evaluate sands as a source of enterococci to nearshore waters, and to assess the relationship between environmental factors and dry-weather enterococci abundance. Best-fit multiple linear regressions used environmental variables to explain more than half of the observed variation in enterococci in water and dry sands. Notably, during dry weather the abundance of enterococci in dry sands at the mean high-tide line was significantly positively related to sand moisture content (ranging from mean ENT in water could be predicted by a linear regression with turbidity alone. Temperature was also positively correlated with ENT abundance in this study, which may indicate an important role of seasonal warming in temperate regions. Inundation by spring tides was the primary rewetting mechanism that sustained culturable enterococci populations in high-tide sands. Tidal forcing modulated the abundance of enterococci in the water, as both turbidity and enterococci were elevated during ebb and flood tides. The probability of samples violating the single-sample maximum was significantly greater when collected during periods with increased tidal range: spring ebb and flood tides. Tidal forcing also affected groundwater mixing zones, mobilizing enterococci from sand to water. These data show that routine monitoring programs using discrete enterococci measurements may be biased by tides and other environmental factors, providing a flawed basis for beach closure decisions.

  16. High-temperature expansion and knock-out properties of moulding sands with water glass

    Directory of Open Access Journals (Sweden)

    Major-Gabryś K.

    2007-01-01

    Full Text Available The article focuses on the topic of improving the knock-out properties of moulding sand with water glass and ester hardener. It is settled that the cause of worse knock-out properties of moulding sand can be brought by their thermal expansion in increased temperatures. There is a presentation of the influence of different additives, containing Al2O3, on moulding sands’ expansion in increased temperatures. Within the frames of research, there was an elaboration of the influence of authors own additive- Glassex, on the expansion phenomenon of moulding sands with water glass and ester hardener. It is concluded, that the new additive stops the expansion of moulding sands and as well it improves their knock-out properties.

  17. Biodegradation of gasoline compounds (BTEX) in a water works sand filter

    DEFF Research Database (Denmark)

    Arvin, Erik; Engelsen, P.; Sebber, U.

    2004-01-01

    Various chemical compounds including aromatic gasoline compounds frequently contaminate drinking water wells in urban areas. Because ground water treatment is simple, usually consisting of aeration/stripping and sand-filtration, it is of significant interest to know the ability of the conventional...... treatment to remove the chemical contaminants. The removal of gasoline compounds was investigated in a two-stage pilot scale sand filter, each with a filter depth of 0.8-1 m and with a filtration rate of 7.6 m/h. The concentrations of aromatic compounds were in the range 7-15 mu g/L, which are realistically...... sand grains). Influent iron concentrations in the range 0-4 mg/L and backwashing did not adversely affect the biodegradation of hydrocarbons. This study has shown that a conventional biological active sand filter can act as an efficient barrier against gasoline compounds, thereby saving the consumer...

  18. Potential of the application of the modified polysaccharides water solutions as binders of moulding sands

    Directory of Open Access Journals (Sweden)

    K. Kaczmarska

    2015-10-01

    Full Text Available The results of preliminary tests of selected properties of the moulding sands with the binder in the form of a 5 % water solution of the sodium salt of carboxymethyl starch (with a degree of substitution (DS of 0,2 and 0,87 arepresented in this study. The moulding sand properties such as permeability, abrasion resistance, tensile and bendingstrength - after curing - are shown in series of tests. The cure process was conducted in a field of electromagnetic radiation within the microwave range. The effect of the microwave treatment on the moulding sand was evaporating of water (solvent in a binder and cross-linking of the polymeric binder. As a result the cured moulding sands with particular properties, essential in the context of its application in the mould technology in the foundry industry, were obtained.

  19. Release of Escherichia coli from Foreshore Sand and Pore Water during Intensified Wave Conditions at a Recreational Beach.

    Science.gov (United States)

    Vogel, Laura J; O'Carroll, Denis M; Edge, Thomas A; Robinson, Clare E

    2016-06-01

    Foreshore beach sands and pore water may act as a reservoir and nonpoint source of fecal indicator bacteria (FIB) to surface waters. This paper presents data collected at a fine sand beach on Lake Huron, Canada over three field events. The data show that foreshore sand erosion as wave height increases results in elevated Escherichia coli concentrations in surface water, as well as depletion of E. coli from the foreshore sand and pore water. E. coli initially attached to foreshore sand rather than initially residing in the pore water was found to be the main contributor to elevated surface water concentrations. Surface water E. coli concentrations were a function of not only wave height (and associated sand erosion) but also the time elapsed since a preceding period of high wave intensity. This finding is important for statistical regression models used to predict beach advisories. While calculations suggest that foreshore sand erosion may be the dominant mechanism for releasing E. coli to surface water during intensified wave conditions at a fine sand beach, comparative characterization of the E. coli distribution at a coarse sand-cobble beach suggests that interstitial pore water flow and discharge may be more important for coarser sand beaches.

  20. Mass spectral characterisation of a polar, esterified fraction of an organic extract of an oil sands process water.

    Science.gov (United States)

    Rowland, S J; Pereira, A S; Martin, J W; Scarlett, A G; West, C E; Lengger, S K; Wilde, M J; Pureveen, J; Tegelaar, E W; Frank, R A; Hewitt, L M

    2014-11-15

    Characterising complex mixtures of organic compounds in polar fractions of heavy petroleum is challenging, but is important for pollution studies and for exploration and production geochemistry. Oil sands process-affected water (OSPW) stored in large tailings ponds by Canadian oil sands industries contains such mixtures. A polar OSPW fraction was obtained by silver ion solid-phase extraction with methanol elution. This was examined by numerous methods, including electrospray ionisation (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS) and ultra-high-pressure liquid chromatography (uHPLC)/Orbitrap MS, in multiple ionisation and MS/MS modes. Compounds were also synthesised for comparison. The major ESI ionisable compounds detected (+ion mode) were C15-28 SO3 species with 3-7 double bond equivalents (DBE) and C27-28 SO5 species with 5 DBE. ESI-MS/MS collision-induced losses were due to water, methanol, water plus methanol and water plus methyl formate, typical of methyl esters of hydroxy acids. Once the fraction was re-saponified, species originally detected by positive ion MS, could be detected only by negative ion MS, consistent with their assignment as sulphur-containing hydroxy carboxylic acids. The free acid of a keto dibenzothiophene alkanoic acid was added to an unesterified acid extract of OSPW in known concentrations as a putative internal standard, but attempted quantification in this way proved unreliable. The results suggest the more polar acidic organic SO3 constituents of OSPW include C15-28  S-containing, alicyclic and aromatic hydroxy carboxylic acids. SO5 species are possibly sulphone analogues of these. The origin of such compounds is probably via further biotransformation (hydroxylation) of the related S-containing carboxylic acids identified previously in a less polar OSPW fraction. The environmental risks, corrosivity and oil flow assurance effects should be easier to assess, given that partial structures are now known

  1. Moisture diffusion coefficients determination of furan bonded sands and water based foundry coatings

    DEFF Research Database (Denmark)

    Di Muoio, Giovanni Luca; Tiedje, Niels Skat

    2016-01-01

    Moisture content in furan bonded sand and water based coatings can be one of the main causes for gas related defects in large cast iron parts. Moisture diffusion coefficients for these materials are needed to precisely predict the possible moisture levels in foundry moulds. In this study, we firs...... provide an example on how it is possible to apply this knowledge to estimate moisture variation in a sand mould during production....

  2. Preliminary study of sand jets in water-capped artificial and real MFT

    Energy Technology Data Exchange (ETDEWEB)

    Cai, J.; Zhu, D.; Rajaratnam, N. [Alberta Univ., Edmonton, AB (Canada). Dept. of Civil and Environmental Engineering

    2008-07-01

    A preliminary study of sand jets in water-capped artificial and real MFT was presented. Background information on oil sands tailing reclamation including water capping and sand capping were first discussed, followed by background information to the study, including non-Newtonian fluids and laponite clay, the artificial clay used mainly in small amounts as a rheology modifier in industrial fluids and materials. Although laponite clay is insoluble in water, it hydrates to make a clear and colourless colloidal, which is thixotropic and also behaves as a Bingham plastic fluid. The benefit of using gels made from laponite is the ability to see through to observe the physical processes in it. The objectives of the study were to examine the dynamics of sand jets in water-capped laponite gel and real MFT; improve the understanding of physical processes related to MFT and sand/slurry operations in tailings ponds; and find potential applications in recycling processed water and decommissioning of tailings ponds. It was concluded that it is much more difficult for jets to penetrate water-capped MFT due to larger yield stress in MFT. Future studies will focus on density correction, viscosity adjustment, and sensitivity analysis. tabs., figs.

  3. Total Coliforms and Turbidity Removal of Water in the Continuous Sand Filter

    Directory of Open Access Journals (Sweden)

    AH Mahvi

    2003-09-01

    Full Text Available The continuous filter is a kind of sand filter, which will operate without any interruptions for backwashing and also it accepts high-suspended solid levels in feed stream. Fouled sand is continuously removed from the filter bed, washed and recycled back without interruption with filtration process. Various samples of water with certain amounts of turbidity enter through a feed pipe and being distributed to the filter. A central column runs from top to bottom of the filter. The water is led through an outer tube in the column by a set of radial, distributor arms. The polluted water flows up ward through the sand bed. The water emerges; clean, in the top section of the tank, and eventually spills over a weir, and then inters into a discharge pipe. In this research, the continuous sand filter was studied to determine its disinfection efficiency in addition to turbidity removal. The results showed that the filtered water had a high quality and the turbidity reduction was 95.5 %. Inspecting the work of the filter had revealed that the removal rates of coliforms and microbial colonies were 99.67 % and 98.99 % respectively. On the other hand, by the use of direct filtration, turbidity reduction was over 97 %. In direct filtration, drinking water with less than 1 NTU turbidity was provided. This continuous sand filter has the advantage of stable operation and more energy saving as compared to the conventional ones.

  4. Evaluating regional water scarcity: Irrigated crop water budgets for groundwater management in the Wisconsin Central Sands

    Science.gov (United States)

    Nocco, M. A.; Kucharik, C. J.; Kraft, G.

    2013-12-01

    Regional water scarcity dilemmas between agricultural and aquatic land users pervade the humid northern lake states of Wisconsin, Minnesota, and Michigan, where agricultural irrigation relies on groundwater drawn from shallow aquifers. As these aquifers have strong connectivity to surface waters, irrigation lowers water levels in lakes and wetlands and reduces stream discharges. Irrigation expansion has cultivated a 60-year water scarcity dilemma in The Wisconsin Central Sands, the largest irrigated region in the humid northern lake states, dedicated to potato, maize, and processing vegetable production. Irrigation has depleted Wisconsin Central Sands surface waters, lowering levels in some lakes by over 2 m and drying some coldwater trout streams. Aquatic ecosystems, property values, and recreational uses in some surface waters have been devastated. While the causal link between pumping and surface water stress is established, understanding crop-mediated processes, such as the timing and magnitude of groundwater consumption by evapotranspiration (ET) and groundwater recharge, will be useful in management of groundwater, irrigated cropping systems, and surface water health. Previous modeling and field efforts have compared irrigated crop water use to a natural reference condition on a net annual basis. As a result, we presently understand that for irrigated potatoes and maize, the average annual ET is greater and therefore, the average annual recharge is less than rainfed row crops, grasslands, and both coniferous and deciduous forests. However, we have a limited understanding of the magnitude and timing of ET and recharge from irrigated cropping systems on shorter time scales that proceed with the annual cropping cycle (i.e. planting, full canopy, harvest, residue cover). We seek to understand the spatiotemporal variability of crop water budgets and associated water scarcity in the Wisconsin Central Sands through detailed measurements of drainage (potential

  5. Water quality, weather and environmental factors associated with fecal indicator organism density in beach sand at two recreational marine beaches

    Science.gov (United States)

    Heaney, Christopher D.; Exum, Natalie G.; Dufour, Alfred P.; Brenner, Kristen P.; Haugland, Richard A.; Chern, Eunice; Schwab, Kellogg J.; Love, David C.; Serre, Marc L.; Noble, Rachel; Wade, Timothy J.

    2015-01-01

    Recent studies showing an association between fecal indicator organisms (FIOs) in sand and gastrointestinal (GI) illness among beachgoers with sand contact have important public health implications because of the large numbers of people who recreate at beaches and engage in sand contact activities. Yet, factors that influence fecal pollution in beach sand remain unclear. During the 2007 National Epidemiological and Environmental Assessment of Recreational (NEEAR) Water Study, sand samples were collected at three locations (60 m apart) on weekend days (Sat, Sun) and holidays between June and September at two marine beaches — Fairhope Beach, AL and Goddard Beach, RI — with nearby publicly-owned treatment works (POTWs) outfalls. F+ coliphage, enterococci, Bacteroidales, fecal Bacteroides spp., and Clostridium spp. were measured in sand using culture and qPCR-based calibrator-cell equivalent methods. Water samples were also collected on the same days, times and transects as the 144 sand samples and were assayed using the same FIO measurements. Weather and environmental data were collected at the time of sample collection. Mean FIO concentrations in sand varied over time, but not space. Enterococci CFU and CCE densities in sand were not correlated, although other FIOs in sand were. The strongest correlation between FIO density in sand and water was fecal Bacteroides CCE, followed by enterococci CFU, Clostridium spp. CCE, and Bacteroidales CCE. Overall, the factors associated with FIO concentrations in sand were related to the sand–water interface (i.e., sand-wetting) and included daily average densities of FIOs in water, rainfall, and wave height. Targeted monitoring that focuses on daily trends of sand FIO variability, combined with information about specific water quality, weather, and environmental factors may inform beach monitoring and management decisions to reduce microbial burdens in beach sand. The views expressed in this paper are those of the authors

  6. Submerged Pond Sand Filter—A Novel Approach to Rural Water Supply

    Directory of Open Access Journals (Sweden)

    Mia Øhlenschlæger

    2016-06-01

    Full Text Available This study describes the new design and function of a modified version of a traditional slow sand filter. The Submerged Pond Sand Filter is built inside a pond and has a vertical as well as a horizontal flow of water through a sloped filter opening. The filter provides treated drinking water to a rural Indian village. The filter has functioned with minimal maintenance for five years without being subject to the typical scraping off and changing of sand as needed in traditional slow sand filters every few months. This five-year study showed bacterial removal efficiency of 97% on average with a level of faecal coliforms of 2 ± 2 colony forming units (CFU/100 mL measured in the treated water. Turbidity was visibly removed during treatment. When water was retrieved from the filter through a manual pump for long consistent time intervals (60 min, faecal coliform counts increased from four to 10 CFU/100 mL on average compared to shorter pumping intervals (5 min. Though the treated water did not comply with the World Health Organization standards of 0 CFU/100 mL, the filter significantly improved water quality and provided one of the best sources of drinkable water in a water-depleted area, where only surface water was available. Furthermore, it is a sustainable treatment method due to low maintenance requirements.

  7. Experimental Investigation on Dilation Mechanisms of Land-Facies Karamay Oil Sand Reservoirs under Water Injection

    Science.gov (United States)

    Lin, Botao; Jin, Yan; Pang, Huiwen; Cerato, Amy B.

    2016-04-01

    The success of steam-assisted gravity drainage (SAGD) is strongly dependent on the formation of a homogeneous and highly permeable zone in the land-facies Karamay oil sand reservoirs. To accomplish this, hydraulic fracturing is applied through controlled water injection to a pair of horizontal wells to create a dilation zone between the dual wells. The mechanical response of the reservoirs during this injection process, however, has remained unclear for the land-facies oil sand that has a loosely packed structure. This research conducted triaxial, permeability and scanning electron microscopy (SEM) tests on the field-collected oil sand samples. The tests evaluated the influences of the field temperature, confining stress and injection pressure on the dilation mechanisms as shear dilation and tensile parting during injection. To account for petrophysical heterogeneity, five reservoir rocks including regular oil sand, mud-rich oil sand, bitumen-rich oil sand, mudstone and sandstone were investigated. It was found that the permeability evolution in the oil sand samples subjected to shear dilation closely followed the porosity and microcrack evolutions in the shear bands. In contrast, the mudstone and sandstone samples developed distinct shear planes, which formed preferred permeation paths. Tensile parting expanded the pore space and increased the permeability of all the samples in various degrees. Based on this analysis, it is concluded that the range of injection propagation in the pay zone determines the overall quality of hydraulic fracturing, while the injection pressure must be carefully controlled. A region in a reservoir has little dilation upon injection if it remains unsaturated. Moreover, a cooling of the injected water can strengthen the dilation potential of a reservoir. Finally, it is suggested that the numerical modeling of water injection in the Karamay oil sand reservoirs must take into account the volumetric plastic strain in hydrostatic loading.

  8. Thermal diffusivity of peat, sand and their mixtures at different water contents

    Science.gov (United States)

    Gvozdkova, Anna; Arkhangelskaya, Tatiana

    2014-05-01

    Thermal diffusivity of peat, sand and their mixtures at different water contents was studied using the unsteady-state method described in (Parikh et al., 1979). Volume sand content in studied samples was 0 % (pure peat), 5, 10, 15, 20, 30, 40, 50, 55 and 62 % (pure sand). Thermal diffusivity of air-dry samples varied from 0.6×10-7m2s-1 for pure peat to 7.0×10-7m2s-1 for pure sand. Adding 5 and 10 vol. % of sand didn't change the thermal diffusivity of studied mixture as compared with that of the pure air-dry peat. Adding 15 % of sand resulted in significant increase of thermal diffusivity by approximately 1.5 times: from 0.6×10-7m2s-1 to 0.9×10-7m2s-1. It means that small amounts of sand with separate sand particles distributed within the peat don't contribute much to the heat transfer through the studied media. And there is a kind of threshold between the 10 and 15 vol. % of sand, after which the continuous sandy chains are formed within the peat, which can serve as preferential paths of heat transport. Adding 20 and 30 % of sand resulted in further increase of thermal diffusivity to 1.3×10-7m2s-1 and 1.7×10-7m2s-1, which is more than two and three times greater than the initial value for pure peat. Thermal diffusivity vs. moisture content dependencies had different shapes. For sand contents of 0 to 40 vol. % the thermal diffusivity increased with water content in the whole studied range from air-dry samples to the capillary moistened ones. For pure peat the experimental curves were almost linear; the more sand was added the more pronounced became the S-shape of the curves. For sand contents of 50 % and more the curves had a pronounced maximum within the range of water contents between 0.10 and 0.25 m3m-3 and then decreased. The experimental k(θ) curves, where k is soil thermal diffusivity, θ is water content, were parameterized with a 4-parameter approximating function (Arkhangelskaya, 2009, 2014). The suggested approximation has an advantage of clear

  9. Effects of full-scale beach renovation on fecal indicator levels in shoreline sand and water.

    Science.gov (United States)

    Hernandez, Rafael J; Hernandez, Yasiel; Jimenez, Nasly H; Piggot, Alan M; Klaus, James S; Feng, Zhixuan; Reniers, Ad; Solo-Gabriele, Helena M

    2014-01-01

    Recolonization of enterococci, at a non-point source beach known to contain high background levels of bacteria, was studied after a full-scale beach renovation project. The renovation involved importation of new exogenous sand, in addition to infrastructure improvements. The study's objectives were to document changes in sand and water quality and to evaluate the relative contribution of different renovation activities towards these changes. These objectives were addressed: by measuring enterococci levels in the sand and fecal indicator bacteria levels (enterococci and fecal coliform) in the water, by documenting sediment characteristics (mineralogy and biofilm levels), and by estimating changes in observable enterococci loads. Analysis of enterococci levels on surface sand and within sediment depth cores were significantly higher prior to beach renovation (6.3-72 CFU/g for each sampling day) when compared to levels during and after beach renovation (0.8-12 CFU/g) (P < 0.01). During the renovation process, sand enterococci levels were frequently below detection limits (<0.1 CFU/g). For water, exceedances in the regulatory thresholds that would trigger a beach advisory decreased by 40% for enterococci and by 90% for fecal coliform. Factors that did not change significantly between pre- and post- renovation included the enterococci loads from animals (approx. 3 × 10(11) CFU per month). Factors that were observed to change between pre- and post- renovation activities included: the composition of the beach sand (64% versus 98% quartz, and a significant decrease in biofilm levels) and loads from direct stormwater inputs (reduction of 3 × 10(11) CFU per month). Overall, this study supports that beach renovation activities contributed to improved sand and water quality resulting in a 50% decrease of observable enterococci loads due to upgrades to the stormwater infrastructure. Of interest was that the change in the sand mineralogy also coincided with changes in biofilm

  10. Slow-sand water filter: design, implementation, accessibility and sustainability in developing countries.

    Science.gov (United States)

    Clark, Peter A; Pinedo, Catalina Arango; Fadus, Matthew; Capuzzi, Stephen

    2012-07-01

    The need for clean water has risen exponentially over the globe. Millions of people are affected daily by a lack of clean water, especially women and children, as much of their day is dedicated to collecting water. The global water crisis not only has severe medical implications, but social, political, and economic consequences as well. The Institute of Catholic Bioethics at Saint Joseph's University has recognized this, and has designed a slow-sand water filter that is accessible, cost-effective, and sustainable. Through the implementation of the Institute's slow-sand water filter and the utilization of microfinancing services, developing countries will not only have access to clean, drinkable water, but will also have the opportunity to break out of a devastating cycle of poverty.

  11. Rice straw biochar affects water retention and air movement in a sand-textured tropical soil

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Ahmed, Fauziatu

    2017-01-01

    Despite the current global attention on biochar (BC) as a soil amendment, knowledge is limited on how BC impacts the physical properties of coarse-textured soils (sand > 95%), particularly in tropical regions. A two-season field-study was conducted to investigate the effect of rice straw BC (3% w....../w) on water retention, gas transport and structure of a sand-textured tropical soil. We sampled 3 months and 15 months after BC application and measured wet- and dry-region soil water retention, air permeability and gas diffusivity at selected matric potentials. At all measured potentials and for both...... and over time provide better structure for agricultural purposes....

  12. Bitumen recovery from surface mined oil sands recycle water ponds

    Energy Technology Data Exchange (ETDEWEB)

    Mikula, R.J.; Munoz, V.A.; Elliott, G. L. [Natural Resources Canada, CanmetENERGY, Devon, Alberta (Canada)

    2011-07-01

    In surface mined oil sands, high bitumen recovery can be achieved but tailings have accumulated over the years. Several technologies have been proposed for recovering bitumen from tailings, but because this bitumen carries high surfactant concentrations there have been processing problems. This paper presents the application of oxidized ore characterization and processing methods to process tailings pond bitumen. Laboratory tests were carried out to characterize bitumen samples coming from four different tailings sources and tests were run with caustic additive. Results showed that high caustic additions can be applied to surfactant rich tailings pond bitumen to avoid downstream froth treatment emulsion problems; the oxidation degree should be carefully monitored. This study demonstrated that the use of caustic additive, already used for oxidized ores, can be applied to treat the bitumen recovered from tailings streams.

  13. Productivity of chironomid larvae exposed to oil sands process water : in situ vs. lab bioassay results

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, K.; Ciborowski, J. [Windsor Univ., ON (Canada)

    2010-07-01

    Oil sands process water (OSPW) contains toxic concentrations of salts and napthenic acids that may compromise wetland reclamation efforts. The productivity of wetland biota is one of the criteria used by the Alberta government to determine if land leased to oil sands mining companies is restored. This study determined how chironomid productivity is influenced by the water from oil sands process material (OSPM) affected wetland. In this study, 26 10-day in situ and laboratory bioassays from water of three oil sands process material (OSPM) were compared with water from 3 reference wetlands to determine the influence of water from OSPM affected wetlands on chironomid productivity. Parallel studies were conducted with Chironomus riparius lab-cultured larvae and Chironomus sp larvae cultured from egg masses collected from an OSPW-affected wetland. In situ, chironomids were housed in small cylinders with fine-mesh netting to allow water exchange and contact with the sediment. Preliminary estimates of chironomids emerging from study wetlands indicated that native and lab cultured chironomids are not uniformly responsive to OSPW.

  14. The influence of Glassex additive on properties of microwave-hardened and self- hardened moulding sands with water glass

    Directory of Open Access Journals (Sweden)

    K. Major-Gabryś

    2012-01-01

    Full Text Available The article takes into consideration the researches concerning inserting the Glassex additive to the microwaved-hardened and self- hardened moulding sands with water glass. In the research different types of ester hardeners to self-hardened moulding sands with water glass were used. The influence of Glassex additive on retained strength of moulding sands with different hardeners and prepared by different technologies of hardening were tested. The influence of different hardeners and the technology of hardening on retained strength of moulding sand with water glass and the Glassex additive were also estimated.

  15. Amplitude equation for under water sand-ripples in one dimension

    DEFF Research Database (Denmark)

    Sand-ripples under oscillatory water flow form periodic patterns with wave lengths primarily controlled by the amplitude d of the water motion. We present an amplitude equation for sand-ripples in one spatial dimension which captures the formation of the ripples as well as secondary bifurcations...... observed when the amplitude $d$ is suddenly varied. The equation has the form h_t=- ε(h-mean(h))+((h_x)^2-1)h_(xx)- h_(xxxx)+ δ((h_x)^2)_(xx) which, due to the first term, is neither completely local (it has long-range coupling through the average height mean(h)) nor has local sand conservation. We argue...

  16. Ozonation of oil sands process water removes naphthenic acids and toxicity.

    Science.gov (United States)

    Scott, Angela C; Zubot, Warren; MacKinnon, Michael D; Smith, Daniel W; Fedorak, Phillip M

    2008-03-01

    Naphthenic acids are naturally-occurring, aliphatic or alicyclic carboxylic acids found in petroleum. Water used to extract bitumen from the Athabasca oil sands becomes toxic to various organisms due to the presence of naphthenic acids released from the bitumen. Natural biodegradation was expected to be the most cost-effective method for reducing the toxicity of the oil sands process water (OSPW). However, naphthenic acids are poorly biodegraded in the holding ponds located on properties leased by the oil sands companies. In the present study, chemical oxidation using ozone was investigated as an option for mitigation of this toxicity. Ozonation of sediment-free OSPW was conducted using proprietary technology manufactured by Seair Diffusion Systems Inc. Ozonation for 50min generated a non-toxic effluent (based on the Microtox bioassay) and decreased the naphthenic acids concentration by approximately 70%. After 130min of ozonation, the residual naphthenic acids concentration was 2mgl(-1): or = 22).

  17. Geology, Surficial - SAND_ILITH_PTS_IN: Total Thickness of Sand and Gravel in Indiana, Derived from the iLITH Water-Well Database (Indiana Geological Survey, Point Shapefile)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — SAND_ILITH_PTS_IN is a point shapefile that shows total thickness of sand, as derived from logs of water wells in the state of Indiana. (It presents the source data...

  18. Microbial degradation of pesticides in rapid sand filters for treatment of drinking water

    DEFF Research Database (Denmark)

    Hedegaard, Mathilde Jørgensen; Albrechtsen, Hans-Jørgen

    2014-01-01

    to remove pesticides from the water phase and pesticides are detected in 24% of the active Danish waterworks wells. This study aimed at investigating the potential of microbial pesticide removal in rapid sand filters for drinking water treatment. Removal of the pesticides MCPP, bentazone, glyphosate...... of pesticides in the water decreased – MCPP decreased to 42-85%, bentazone to 15-35%, glyphosate to 7-14% and p-nitrophenol 1-3% – from the initial concentration over a period of 6-13 days. The largest microbial removal was observed at Sjælsø waterworks Plant II, where the pesticides were partially mineralised......In Denmark drinking water supply is based on groundwater which is treated by aeration followed by filtration in rapid sand filters. Unfortunately pesticide contamination of the groundwater poses a threat to the water supply, since the simple treatment process at the waterworks is not considered...

  19. Water availability for development of major tar sands areas in Utah

    Energy Technology Data Exchange (ETDEWEB)

    Keefer, T.N.; McQuivey, R.S.

    1979-05-01

    The Sutron Corporation, under contract with Colorado State University, has conducted a study for the Laramie Energy Technology Center (LETC) to determine the availability of water for future extraction of viscous petroleum (bitumen) from the six major tar sands deposits in Utah. Specifically, the areas are: Asphalt Ridge and Whiterocks, which lie immediately west of Vernal, Utah; P.R. Spring, a large area extending from the Colorado River to the White River along Utah's eastern border; Hill Creek, adjacent to P.R. Spring to the west; Sunnyside, immediately across the Green River from Hill Creek between the Price and Green Rivers; and Tar Sand Triangle, near the confluence of the Colorado and Dirty Devil Rivers. The study, conducted between September and December of 1978, was a fact-finding effort involving the compilation of information from publications of the US Geological Survey (USGS), Utah State Engineer, Utah Department of Natural Resources, and other federal and state agencies. The information covers the general physiographic and geologic features of the total area, the estimated water requirements for tar sands development, the availability of water in each of the six areas, and the legal and sociological restraints and impacts. The conclusions regarding water availability for tar sands development in each of the six areas and specific recommendations related to the development of each area are presented also.

  20. Status of water quality subject to sand mining in the kelantan river, kelantan.

    Science.gov (United States)

    Peck Yen, Tan; Rohasliney, H

    2013-08-01

    This paper aimed to describe the effects of sand mining on the Kelantan River with respect to physical and chemical parameter analyses. Three replicates of water samples were collected from five stations along the Kelantan River (November 2010 until February 2011). The physical parameters included water temperature, water conductivity, dissolved oxygen (DO), pH, total dissolved solids (TDS), total suspended solids (TSS) and turbidity, whereas the chemical parameters included the concentration of nitrogen nutrients such as ammonia, nitrate and nitrite. The Kelantan River case study revealed that TSS, turbidity and nitrate contents exceed the Malaysian Interim National Water Quality Standard (INWQS) range and are significantly different between Station 1 (KK) and Station 3 (TM). Station 1 has the largest variation of TDS, TSS, turbidity and nitrogen nutrients because of sand mining and upstream logging activities. The extremely high content of TSS and the turbidity have caused poor and stressful conditions for the aquatic life in the Kelantan River.

  1. Stratification of nitrification activity in rapid sand filters for drinking water treatment

    DEFF Research Database (Denmark)

    Tatari, Karolina; Smets, Barth F.; Musovic, Sanin

    2013-01-01

    Rapid sand filters used in groundwater treatment remove ammonium, iron and manganese from the water. Ammonium is removed biologically by nitrifying microorganisms attached on the sand surface. Nitrification kinetics and activity is strongly affected by filter design and operation, which are the key...... parameters in process optimization. Nitrification optimization needs a detailed insight of the process and the way it takes place in the filter. Filters are often considered in a “black box” approach, where data are only available for influent and effluent and the entire filter is assumed homogenous. The aim...... of this study is to investigate nitrification activity in a rapid sand filter, with focus on its homogeneity and how it relates to filter performance. Two groundwater treatment plants in Denmark were selected for the experimental investigations. Plant 1 operates a single line of pre and after filters and has...

  2. Effects of dynamic operating conditions on nitrification in biological rapid sand filters for drinking water treatment

    DEFF Research Database (Denmark)

    Lee, Carson Odell; Boe-Hansen, Rasmus; Musovic, Sanin

    2014-01-01

    Biological rapid sand filters are often used to remove ammonium from groundwater for drinking water supply. They often operate under dynamic substrate and hydraulic loading conditions, which can lead to increased levels of ammonium and nitrite in the effluent. To determine the maximum nitrification...... operating conditions. The ammonium removal rate of the filter was determined by the ammonium loading rate, but was independent of both the flow and influent ammonium concentration individually. Ammonia-oxidizing bacteria and archaea were almost equally abundant in the filter. Both ammonium removal...... rates and safe operating windows of rapid sand filters, a pilot scale rapid sand filter was used to test short-term increased ammonium loads, set by varying either influent ammonium concentrations or hydraulic loading rates. Ammonium and iron (flock) removal were consistent between the pilot...

  3. Reduction of steel-ball velocity using sand or water layer accelerated by high explosive

    Science.gov (United States)

    Homae, Tomotaka; Wakabayashi, Kunihiko; Matsumura, Tomoharu; Nakayama, Yoshio

    2007-06-01

    The reduction of steel-ball velocity using sand or water was studied. A steel ball, diameter of 9.525 mm, was accelerated using comp. C-4 explosive of 37-52 g. After free flight of about 500-750 mm, the steel ball passed through a sand layer in thickness of 30-125 mm, or a water layer in thickness of 75 or 150 mm. The velocities before and after passage of the layer were determined using a high-speed camera. Although the velocity before the passage was varied from about 300 m/s to about 750 m/s, the velocity after passage was almost constant. The velocity depended only on the kind of materials or thickness of the layer. Sand was more effective in reduction than water for same areal density. Moreover, the steel-ball was accelerated in contact with sand layer in thickness of 30-125 mm. The terminal velocity in such case was comparable to that experienced free fright described above.

  4. Water Glass Modification and its Impact on the Mechanical Properties of Moulding Sands

    OpenAIRE

    A. Kmita; B. Hutera

    2013-01-01

    The purpose of the presented experiment was to develop an effective water glass modifier. In the conducted research, an attempt was made to determine the effect of modifier addition on the wettability of quartz grains, viscosity and cohesion of binder and strength RmUof the sand mixture. Water glass modification was carried out with, obtained in electrochemical process [1], colloidal suspension of ZnO nanoparticles in methanol (modifier I) or propanol (modifier II), characterised by a constan...

  5. The stable isotopes of site wide waters at an oil sands mine in northern Alberta, Canada

    Science.gov (United States)

    Baer, Thomas; Barbour, S. Lee; Gibson, John J.

    2016-10-01

    Oil sands mines have large disturbance footprints and contain a range of new landforms constructed from mine waste such as shale overburden and the byproducts of bitumen extraction such as sand and fluid fine tailings. Each of these landforms are a potential source of water and chemical release to adjacent surface and groundwater, and consequently, the development of methods to track water migration through these landforms is of importance. The stable isotopes of water (i.e. 2H and 18O) have been widely used in hydrology and hydrogeology to characterize surface water/groundwater interactions but have not been extensively applied in mining applications, or specifically to oil sands mining in northern Alberta. A prerequisite for applying these techniques is the establishment of a Local Meteoric Water Line (LMWL) to characterize precipitation at the mine sites as well as the development of a 'catalogue' of the stable water isotope signatures of various mine site waters. This study was undertaken at the Mildred Lake Mine Site, owned and operated by Syncrude Canada Ltd. The LMWL developed from 2 years (2009/2012) of sample collection is shown to be consistent with other LMWLs in western Canada. The results of the study highlight the unique stable water isotope signatures associated with hydraulically placed tailings (sand or fluid fine tailings) and overburden shale dumps relative to natural surface water and groundwater. The signature associated with the snow melt water on reclaimed landscapes was found to be similar to ground water recharge in the region. The isotopic composition of the shale overburden deposits are also distinct and consistent with observations made by other researchers in western Canada on undisturbed shales. The process water associated with the fine and coarse tailings streams has highly enriched 2H and 18O signatures. These signatures are developed through the non-equilibrium fractionation of imported fresh river water during evaporation from

  6. Filtration treatment of processing kapuas river's water by coral sands/kaolinite/activated carbon

    Science.gov (United States)

    Sasri, Risya; Wahyuni, Nelly; Utomo, Kiki Prio

    2017-03-01

    Filtration treatment of processing Kapuas river's water in the Sepuk Keladi village, West Kalimantan has been conducted. The aims of the treatments to process kapuas river's water with the characteristics of peat into clean water. Processing method using flow-up-flow filtration system with filter media coral sands / kaolinite / activated carbon. Coral sands was obtained from Kijing beach and characterized using X-Ray Diffraction (XRD) and BET method. The XRD spectrum showed strongest peak at 33.09°, 52.40°, 29.34° and it can be concluded that mineral was verified corresponding to calcium consisting of calcite phase. While the result of BET plot point that surface area of coral sands was 4.954 m2/g. The effectiveness of the filtration media was determined by testing parameters such as pH, total suspended solid (TSS), total dissolved solid (TDS), chloride as Cl, and iron as Fe, before and after filtration of Kapuas river's water. The result show that kapuas river's water after filtration treatment was increased pH from 6,53 to 7,2. Filtration using this systems resulted in an average 43,53% reduction in TSS, 91,63% reduction in TDS, 83,63% reduction in content of chloride as Cl and 33,56 % reduction in content iron as Fe, respectively.

  7. Policy Analysis of Water Availability and Use Issues for Domestic Oil Shale and Oil Sands Development

    Energy Technology Data Exchange (ETDEWEB)

    Ruple, John; Keiter, Robert

    2010-12-31

    Oil shale and oil sands resources located within the intermountain west represent a vast, and as of yet, commercially untapped source of energy. Development will require water, and demand for scarce water resources stands at the front of a long list of barriers to commercialization. Water requirements and the consequences of commercial development will depend on the number, size, and location of facilities, as well as the technologies employed to develop these unconventional fuels. While the details remain unclear, the implication is not – unconventional fuel development will increase demand for water in an arid region where demand for water often exceeds supply. Water demands in excess of supplies have long been the norm in the west, and for more than a century water has been apportioned on a first-come, first-served basis. Unconventional fuel developers who have not already secured water rights stand at the back of a long line and will need to obtain water from willing water purveyors. However, uncertainty regarding the nature and extent of some senior water claims combine with indeterminate interstate river management to cast a cloud over water resource allocation and management. Quantitative and qualitative water requirements associated with Endangered Species protection also stand as barriers to significant water development, and complex water quality regulations will apply to unconventional fuel development. Legal and political decisions can give shape to an indeterminate landscape. Settlement of Northern Ute reserved rights claims would help clarify the worth of existing water rights and viability of alternative sources of supply. Interstate apportionment of the White River would go a long way towards resolving water availability in downstream Utah. And energy policy clarification will help determine the role oil shale and oil sands will play in our nation’s future.

  8. Policy Analysis of Water Availability and Use Issues for Domestic Oil Shale and Oil Sands Development

    Energy Technology Data Exchange (ETDEWEB)

    Ruple, John [Univ. of Utah, Salt Lake City, UT (United States); Keiter, Robert [Univ. of Utah, Salt Lake City, UT (United States)

    2010-03-01

    Oil shale and oil sands resources located within the intermountain west represent a vast, and as of yet, commercially untapped source of energy. Development will require water, and demand for scarce water resources stands at the front of a long list of barriers to commercialization. Water requirements and the consequences of commercial development will depend on the number, size, and location of facilities, as well as the technologies employed to develop these unconventional fuels. While the details remain unclear, the implication is not – unconventional fuel development will increase demand for water in an arid region where demand for water often exceeds supply. Water demands in excess of supplies have long been the norm in the west, and for more than a century water has been apportioned on a first-come, first-served basis. Unconventional fuel developers who have not already secured water rights stand at the back of a long line and will need to obtain water from willing water purveyors. However, uncertainty regarding the nature and extent of some senior water claims combine with indeterminate interstate river management to cast a cloud over water resource allocation and management. Quantitative and qualitative water requirements associated with Endangered Species protection also stand as barriers to significant water development, and complex water quality regulations will apply to unconventional fuel development. Legal and political decisions can give shape to an indeterminate landscape. Settlement of Northern Ute reserved rights claims would help clarify the worth of existing water rights and viability of alternative sources of supply. Interstate apportionment of the White River would go a long way towards resolving water availability in downstream Utah. And energy policy clarification will help determine the role oil shale and oil sands will play in our nation’s future.

  9. Removal of Cryptosporidium and polystyrene microspheres from swimming pool water with sand, cartridge, and precoat filters.

    Science.gov (United States)

    Amburgey, James E; Walsh, Kimberly J; Fielding, Roy R; Arrowood, Michael J

    2012-03-01

    Cryptosporidium has caused the majority of waterborne disease outbreaks in treated recreational water venues in the USA for many years running. This research project evaluated some common US swimming pool filters for removing Cryptosporidium oocysts, 5-µm diameter polystyrene microspheres, and 1-µm diameter polystyrene microspheres. A 946 L hot tub with interchangeable sand, cartridge, and precoat filters was used at room temperature for this research. Simulated pool water for each experiment was created from Charlotte, NC (USA) tap water supplemented with alkalinity, hardness, chlorine, and a mixture of artificial sweat and urine. Precoat (i.e., diatomaceous earth and perlite) filters demonstrated pathogen removal efficiencies of 2.3 to 4.4 log (or 99.4-99.996%). However, sand and cartridge filters had average Cryptosporidium removals of 0.19 log (36%) or less. The combined low filter removal efficiencies of sand and cartridge filters along with the chlorine-resistant properties of Cryptosporidium oocysts could indicate a regulatory gap warranting further attention and having significant implications on the protection of public health in recreational water facilities. The 5-µm microspheres were a good surrogate for Cryptosporidium oocysts in this study and hold promise for use in future research projects, field trials, and/or product testing on swimming pool filters.

  10. Metal removal from oil sands tailings pond water by indigenous micro-alga.

    Science.gov (United States)

    Mahdavi, Hamed; Ulrich, Ania C; Liu, Yang

    2012-09-01

    This paper reports the removal of ten target metals of environmental concern ((53)Cr, Mn, Co, (60)Ni, (65)Cu, (66)Zn, As, (88)Sr, (95)Mo, and Ba) from oil sands tailings pond water. The organism responsible for removal was found to be an indigenous green micro-alga identified as Parachlorella kessleri by sequencing of the 23S rRNA gene. P. kessleri grew in tailings pond water samples taken from two oil sands operators (Syncrude Canada Ltd. and Albian Sands Energy Inc.), and enriched with low (0.24 mM NO(3)(-) and 0.016 mM PO(4)(-3)) and high (1.98 mM NO(3)(-) and 0.20mM PO(4)(-3)) concentrations of nutrient supplements (the most realistic scenario). The removal of (60)Ni, (65)Cu, As, (88)Sr, (95)Mo, and Ba from Syncrude tailings pond water was significantly enhanced by high concentrations of nitrogen and phosphorus, whereas the high nutrient concentrations adversely affected the removal of Co, (60)Ni, As, (88)Sr, and Mo in samples of Albian tailings pond water. Based on ANOVA two-factor analysis, higher nutrient concentration does not always result in higher metal removal, and TPW source must also be considered. Copyright © 2012. Published by Elsevier Ltd.

  11. X-ray computed-tomography observations of water flow through anisotropic methane hydrate-bearing sand

    Energy Technology Data Exchange (ETDEWEB)

    Seol, Yongkoo; Kneafsey, Timothy J.

    2009-06-01

    We used X-ray computed tomography (CT) to image and quantify the effect of a heterogeneous sand grain-size distribution on the formation and dissociation of methane hydrate, as well as the effect on water flow through the heterogeneous hydrate-bearing sand. A 28 cm long sand column was packed with several segments having vertical and horizontal layers with sands of different grain-size distributions. During the hydrate formation, water redistribution occurred. Observations of water flow through the hydrate-bearing sands showed that water was imbibed more readily into the fine sand, and that higher hydrate saturation increased water imbibition in the coarse sand due to increased capillary strength. Hydrate dissociation induced by depressurization resulted in different flow patterns with the different grain sizes and hydrate saturations, but the relationships between dissociation rates and the grain sizes could not be identified using the CT images. The formation, presence, and dissociation of hydrate in the pore space dramatically impact water saturation and flow in the system.

  12. The Caustic Alkali-free Water Extraction Agents for Treating Inner Mongolia Oil Sands

    Institute of Scientific and Technical Information of China (English)

    Shen Zhibing; Zhang Juntao; Zhang Jie; Liang Shengrong

    2014-01-01

    The caustic alkali-free water extraction agents were studied for treating the oil sands excavated from Inner Mon-golia, China. Several kinds of chemical reagents were evaluated, among which sodium carbonate (SC), sodium dodecyl benzene sulfonate (SD) and sodium chloride were conifrmed as composite solutes. Their proportion was optimized by an orthogonal test. The optimum proportion of the composite agent covered 0.03%of SD, 0.50%of sodium chloride, 3.00%of SC, with the rest composed of water. The optimal operating condition was also conifrmed. The oil sands were extracted at the following optimized conditions:a treating time of 15 min, a temperature of 80℃and an extraction agent/feed ratio of 1:1, with the bitumen yield reaching more than 96%. The extraction agent after separation from the bitumen product can be recycled for reuse to carve out a good environmentally friendly route.

  13. Comparison of sand-based water filters for point-of-use arsenic removal in China.

    Science.gov (United States)

    Smith, Kate; Li, Zhenyu; Chen, Bohan; Liang, Honggang; Zhang, Xinyi; Xu, Ruifei; Li, Zhilin; Dai, Huanfang; Wei, Caijie; Liu, Shuming

    2017-02-01

    Contamination of groundwater wells by arsenic is a major problem in China. This study compared arsenic removal efficiency of five sand-based point-of-use filters with the aim of selecting the most effective filter for use in a village in Shanxi province, where the main groundwater source had arsenic concentration >200 μg/L. A biosand filter, two arsenic biosand filters, a SONO-style filter and a version of the biosand filter with nails embedded in the sand were tested. The biosand filter with embedded nails was the most consistent and effective under the study conditions, likely due to increased contact time between water and nails and sustained corrosion. Effluent arsenic was below China's standard of 50 μg/L for more than six months after construction. The removal rate averaged 92% and was never below 86%. In comparison, arsenic removal for the nail-free biosand filter was never higher than 53% and declined with time. The arsenic biosand filter, in which nails sit in a diffuser basin above the sand, performed better but effluent arsenic almost always exceeded the standard. This highlights the positive impact on arsenic removal of embedding nails within the top layer of biosand filter sand and the promise of this low-cost filtration method for rural areas affected by arsenic contamination. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Relationship between sand-dust weather and water dynamics of desert areas in the middle reaches of Heihe River

    Institute of Scientific and Technical Information of China (English)

    Yun Niu; XianDe Liu; Xin Li; YanQiang Wei; Hu Zhang; XiaoYan Li

    2016-01-01

    Sand-dust weather has become an international social-environmental issue of common concern, and constitutes a serious threat to human lives and economic development. In order to explore the responses of natural desert sand and dust to the dynamics of water in desertification, we extracted long-term monitoring data related to precipitation, soil water, groundwater, and sand-dust weather. These data originated from the test stations for desertification control in desert areas of the middle reaches of the Heihe River. We used an algorithm of characteristic parameters, correlations, and multiple regression analysis to establish a regression model for the duration of sand-dust weather. The response char-acteristics of the natural desert sand and dust and changes of the water inter-annual and annual variance were also examined. Our results showed: (1) From 2006 to 2014 the frequency, duration, and volatility trends of sand-dust weather obviously increased, but the change amplitudes of precipitation, soil water, and groundwater level grew smaller. (2) In the vegetative growth seasons from March to November, the annual variance rates of the soil moisture content in each of four studied layers of soil samples were similar, and the changes in the frequency and duration of sand-dust weather were similar. (3) Our new regression equation for the duration of sand-dust weather passed the R test, F test, and t test. By this regression model we could predict the duration of sand-dust weather with an accuracy of 42.9%. This study can thus provide technological support and reference data for water resource management and re-search regarding sand-dust weather mechanisms.

  15. Flow pattern and related chemical quality of ground water in the "500-foot" sand in the Memphis area, Tennessee

    Science.gov (United States)

    Bell, Edwin Allen; Nyman, Dale J.

    1968-01-01

    The '500-foot' sand is the major source of water supply for the Memphis area. Thick layers of impervious clay above and below the sand confine the water in the aquifer under artesian pressure and also protect the aquifer from contamination. Recharge from rainfall enters the '500-foot' sand in the outcrop, or intake area south and east of Memphis. Recharge from other aquifers enters the sand wherever the confining beds are breached or absent. Some of the recharge that enters the '500-foot' sand in eastern Arkansas moves down the gradients created by pumping in the Memphis area. All discharge from the '500-foot' sand in the Memphis area results from well pumping. Since 1886 continuous withdrawals at gradually increasing rates of pumping have lowered water levels and altered hydraulic gradients in the area. These withdrawals have resulted in changes in direction and velocity of movement of water through the '500-foot' sand. Water in the sand in the southeaster n part of the Memphis area normally moves from the (outcrop area east and south of Memphis northwestward toward points of withdrawal. In the northwestern part of the area, water moves southeastward toward points of withdrawal. A flow-net analysis of the aquifer shows that the rate of water movement through the '500-foot' sand in 1964, toward the major cones of depression in the Memphis area, was about 350 feet per year, or 1 mile in 15 years. A flow-net analysis projected for the year 1975 indicates the rate will increase by about 20 percent in the 12-year period 1964-75. Water in the '500-foot' sand in the Memphis area is generally a calcium magnesium sodium bicarbonate type. It is soft, low in dissolved solids, high in concentrations of iron and carbon dioxide, and slightly to moderately corrosive. The softest and least mineralized water occurs in the southeastern part of the area, and the water becomes slightly harder and more mineralized as it moves downdip toward Memphis. The hardest and most mineralized

  16. Retention of radium from thermal waters on sand filters and adsorbents

    Energy Technology Data Exchange (ETDEWEB)

    Elejalde, C. [Dpto. de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria, Alameda de Urquijo s/n, 48013 Bilbao (Spain)]. E-mail: inpelsac@bi.ehu.es; Herranz, M. [Dpto. de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria, Alameda de Urquijo s/n, 48013 Bilbao (Spain); Idoeta, R. [Dpto. de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria, Alameda de Urquijo s/n, 48013 Bilbao (Spain); Legarda, F. [Dpto. de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria, Alameda de Urquijo s/n, 48013 Bilbao (Spain); Romero, F. [Dpto. de Ingenieria Quimica y del Medio Ambiente, Escuela Tecnica Superior de Ingenieria, Alameda de Urquijo s/n, 48013 Bilbao (Spain); Baeza, A. [Dpto. de Fisica, Facultad de Veterinaria, Universidad de Extremadura, Avda. Universidad s/n, 10071 Caceres (Spain)

    2007-06-18

    This study was focussed on laboratory experiences of retention of radium from one thermal water on sand filters and adsorbents, trying to find an easy method for the elimination in drinkable waters polluted with this natural radio-nuclide. A thermal water from Cantabria (Spain) was selected for this work. Retention experiences were made with columns of 35 mm of diameter containing 15 cm layers of washed river sand or 4 cm layers of zeolite A3, passing known volumes of thermal water at flows between 4 and 40 ml/min with control of the retained radium by determining the amount in the water after the treatment. The statistical analysis of data suggests that retention depends on the flow and the volume passed through the columns. As additional adsorbents were used kaolin and a clay rich in illite. Jar-test experiences were made agitating known weights of adsorbents with the selected thermal water, with addition of flocculants and determination of radium in filtrated water after the treatment. Data suggest that retention is related to the weight of adsorbent used, but important quantities of radium seem remain in solution for higher amounts of adsorbents, according to the statistical treatment of data. The elution of retained radium from columns or adsorbents, previously used in experiences, should be the aim of a future research.

  17. Organic matter induced mobilization of polymer-coated silver nanoparticles from water-saturated sand.

    Science.gov (United States)

    Yang, Xinyao; Yin, Ziyi; Chen, Fangmin; Hu, Jingjing; Yang, Yuesuo

    2015-10-01

    Mobilization of polymer-coated silver nanoparticles (AgNPs) by anionic surfactant (sodium dodecylbenzenesulphonate: SDBS), amino acid derivative (N-acetylcysteine: NAC), and chelate (ethylenediaminetetraacetic acid: EDTA) in water-saturated sand medium was explored based on carefully designed column tests. Exposure experiments monitoring the size evolution of polyvinylpyrrolidone (PVP) coated AgNPs in organic solutions confirm the capacity of SDBS, NAC and EDTA to partly displace PVP. Single Pulse Column Experiment (SPCE) results show both the PVP polymer and the silver core controlled AgNP deposition while the effect of the PVP was dominant. Results of Co-injected Pulse Column Experiments (CPCEs) where AgNP and SDBS or NAC were co-injected into the column following a very short mixing (organic would mobilize irreversibly deposited particles from the uncoated sand, while surface charge modification by adsorbed NAC was identified as a potential mobilizing mechanism for AgNP from the iron-oxide-coated sand. Triple Pulse Column Experiment (TPCE) results confirm that such a charging effect of the adsorbed organic molecules may enable SDBS and NAC to mobilize AgNPs from the iron-oxide-coated sands. TPCE results with five distinct levels of SDBS indicate that concentration-stimulated change in the SDBS format from an individual to a micelle significantly increased the mobilizing efficiency and site blockage of SDBS. Although being an electrolyte, EDTA did not mobilize AgNPs, as the case with SDBS or NAC, as it dissolved the iron oxides which in turn prevented EDTA adsorption on sand. The findings have implications for better understanding the behavior of polymer-coated nanoparticles in organic-presented groundwater systems, i.e., detachment-associated uncertainty in exposure prediction of the nanomaterials.

  18. HYDRAULIC ELEVATOR INSTALLATION ESTIMATION FOR THE WATER SOURCE WELL SAND-PACK CLEANING UP

    Directory of Open Access Journals (Sweden)

    V. V. Ivashechkin

    2016-01-01

    Full Text Available The article offers design of a hydraulic elevator installation for cleaning up water-source wells of sand packs. It considerers the installation hydraulic circuit according to which the normal pump feeds the high-level tank water into the borehole through two parallel water lines. The water-jet line with washing nozzle for destroying the sand-pack and the supply pipe-line coupled with the operational nozzle of the hydraulic elevator containing the inlet and the supply pipelines for respectively intaking the hydromixture and removing it from the well. The paper adduces equations for fluid motion in the supply and the water-jet pipelines and offers expressions for evaluating the required heads in them. For determining water flow in the supply and the water-jet pipe lines the author proposes to employ graphical approach allowing finding the regime point in Q–H chart by means of building characteristics of the pump and the pipe-lines. For calculating the useful vertical head, supply and dimensions of the hydraulic elevator the article employs the equation of motion quantity with consistency admission of the motion quantity before and after mixing the flows in the hydraulic elevator. The suggested correlations for evaluating the hydraulic elevator efficiency determine the sand pack removal duration as function of its sizes and the ejected fluid flow rate. A hydraulic-elevator installation parameters estimation example illustrates removing a sand pack from a water-source borehole of 41 m deep and 150 mm diameter bored in the village of Uzla of Myadelsk region, of Minsk oblast. The working efficiency of a manufactured and laboratory tested engineering prototype of the hydraulic elevator installation was acknowledged in actual tests at the indicated borehole site. With application of graphical approach, the suggested for the hydraulic elevator installation parameters calculation procedure allows selecting, with given depth and the borehole diameter

  19. Self assembly, mobilization, and flotation of crude oil contaminated sand particles as granular shells on gas bubbles in water.

    Science.gov (United States)

    Tansel, Berrin; Boglaienko, Daria

    2017-01-01

    Contaminant fate and transport studies and models include transport mechanisms for colloidal particles and dissolved ions which can be easily moved with water currents. However, mobilization of much larger contaminated granular particles (i.e., sand) in sediments have not been considered as a possible mechanism due to the relatively larger size of sand particles and their high bulk density. We conducted experiments to demonstrate that oil contaminated granular particles (which exhibit hydrophobic characteristics) can attach on gas bubbles to form granular shells and transfer from the sediment phase to the water column. The interactions and conditions necessary for the oil contaminated granular particles to self assemble as tightly packed granular shells on the gas bubbles which transfer from sediment phase to the water column were evaluated both experimentally and theoretically for South Louisiana crude oil and quartz sand particles. Analyses showed that buoyancy forces can be adequate to move the granular shell forming around the air bubbles if the bubble radius is above 0.001mm for the sand particles with 0.28mm diameter. Relatively high magnitude of the Hamaker constant for the oil film between sand and air (5.81×10(-20)J for air-oil-sand) indicates that air bubbles have high affinity to attach on the oil film that is on the sand particles in comparison to attaching to the sand particles without the oil film in water (1.60×10(-20)J for air-water-sand). The mobilization mechanism of the contaminated granular particles with gas bubbles can occur in natural environments resulting in transfer of granular particles from sediments to the water column. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Influence of Geometric Parameters of the Hydrocyclone and Sand Concentration on the Water/Sand/Heavy-Oil Separation Process: Modeling and Simulation

    Directory of Open Access Journals (Sweden)

    F Farias

    2016-09-01

    Full Text Available In the oil exploitation, produced fluids are composed of oil, gas, water and sand (depending on the reservoir location. The presence of sand in flow oil leads to several industrial problems for example: erosion and accumulation in valves and pipeline. Thus, it is necessary to stop production for manual cleaning of equipments and pipes. These facts have attracted attention of academic and industrial areas, enabling the appearing of new technologies or improvement of the water/oil/sand separation process. One equipment that has been used to promote phase separation is the hydrocyclone due to high performance of separation and required low cost to installation and maintenance. In this sense, the purpose of this work is to study numerically the effect of geometric parameters (vortex finder diameter of the hydrocyclone and sand concentration on the inlet fluid separation process. A numerical solution of the governing equations was obtained by the ANSYS CFX-11 commercial code. Results of the streamlines, pressure drop and separation efficiency on the hydrocyclone are presented and analyzed. It was observed that the particles concentration and geometry affect the separation efficiency of the hydrocyclone.

  1. Water Glass Modification and its Impact on the Mechanical Properties of Moulding Sands

    Directory of Open Access Journals (Sweden)

    A. Kmita

    2013-04-01

    Full Text Available The purpose of the presented experiment was to develop an effective water glass modifier. In the conducted research, an attempt was made to determine the effect of modifier addition on the wettability of quartz grains, viscosity and cohesion of binder and strength RmUof the sand mixture. Water glass modification was carried out with, obtained in electrochemical process [1], colloidal suspension of ZnO nanoparticles in methanol (modifier I or propanol (modifier II, characterised by a constant molar concentration of c = 0.3 M. It was demonstrated that the addition of a colloidal suspension of ZnO nanoparticles in propanol (modifier II had a significant effect on wettability of quartz grains improvement without the accompanying increase in binder viscosity. Testing the mechanical properties RmUof sand mixtures containing modified binder (modifier II hardened at ambient conditions showed an approximately 28% increase in strength compared with the RmUof the sand bonded with an unmodified binder.

  2. Microbial pesticide removal in rapid sand filters for drinking water treatment – Potential and kinetics

    DEFF Research Database (Denmark)

    Hedegaard, Mathilde Jørgensen; Albrechtsen, Hans-Jørgen

    2014-01-01

    or metabolites mecoprop (MCPP), bentazone, glyphosate and p-nitrophenol were applied in initial concentrations of 0.03–2.4 μg/L. In all the investigated waterworks the concentration of pesticides in the water decreased – MCPP decreased to 42–85%, bentazone to 15–35%, glyphosate to 7–14% and p-nitrophenol 1......–3% – from the initial concentration over a period of 6–13 days. Mineralisation of three out of four investigated pesticides was observed at Sjælsø waterworks Plant II – up to 43% of the initial glyphosate was mineralised within six days. At Sjælsø waterworks Plant II the removal kinetics of bentazone......Filter sand samples, taken from aerobic rapid sand filters used for treating groundwater at three Danish waterworks, were investigated for their pesticide removal potential and to assess the kinetics of the removal process. Microcosms were set up with filter sand, treated water, and the pesticides...

  3. Importance of copper for nitrification in biological rapid sand filters for drinking water production

    DEFF Research Database (Denmark)

    Wagner, Florian Benedikt

    When anoxic groundwater is treated to produce drinking water, ammonium is commonly removed through nitrification in rapid sand filters. Nitrification is a biological process, and is mediated by chemoautotrophic microorganisms. Ammonia oxidizing bacteria (AOB) and archaea (AOA) oxidize ammonium......, the reaction rate is sometimes not high enough. This results in incomplete nitrification, with residual ammonium and nitrite concentrations in the finished water, which are problematic for the biological stability of the drinking water. In Denmark, 11 % of the larger water works (>350,000 m3/year) fail...... to remove ammonium to below the national drinking water quality standard of 0.05 mg NH4+/L. A better process understanding of nitrifying biofilters is needed to optimize treatment performance, remediate existing filters, and to prevent future nitrification problems. The frequent incidents of insufficient...

  4. Biological sand filters: low-cost bioremediation technique for production of clean drinking water.

    Science.gov (United States)

    Lea, Michael

    2008-05-01

    Approximately 1.1 billion people in rural and peri-urban communities of developing countries do not have access to safe drinking water. The mortality from diarrheal-related diseases amounts to approximately 2.2 million people each year from the consumption of unsafe water. Most of them are children under 5 years of age-250 deaths an hour from microbiologically contaminated water. There is conclusive evidence that one low-cost household bioremediation intervention, biological sand filters, are capable of dramatically improving the microbiological quality of drinking water. This unit will describe this relatively new and proven bioremediation technology's ability to empower at-risk populations to use naturally occurring biology and readily available materials as a sustainable way to achieve the health benefits of safe drinking water.

  5. Biological sand filters: low-cost bioremediation technique for production of clean drinking water.

    Science.gov (United States)

    Lea, Michael

    2014-05-01

    Approximately 1.1 billion people in rural and peri-urban communities of developing countries do not have access to safe drinking water. The mortality from diarrheal-related diseases amounts to ∼2.2 million people each year from the consumption of unsafe water. Most of them are children under 5 years of age--250 deaths an hour from microbiologically contaminated water. There is conclusive evidence that one low-cost household bioremediation intervention, use of biological sand filters, is capable of dramatically improving the microbiological quality of drinking water. This unit will describe this relatively new and proven bioremediation technology's ability to empower at-risk populations to use naturally occurring biological principles and readily available materials as a sustainable way to achieve the health benefits of safe drinking water.

  6. Performance of wetland forbs transplanted into marshes amended with oil sands processed water.

    Science.gov (United States)

    Mollard, Federico P O; Roy, Marie-Claude; Foote, A Lee

    2015-03-01

    Companies mining oil sands in Alberta (Canada) face the challenge of reclaiming wetlands under water use restrictions. Wetland reclamation after mining will generate marshes characterized by elevated salinity and residual hydrocarbons. Oil sands wetlands are also impoverished in forbs, suggesting that their establishment may be constrained by water chemistry. We transplanted skullcap, mint, and smartweed plants into experimental trenches that simulated two possible reclamation scenarios: wetlands amended with on-site freshwater or with oil sands processed water (OSPW). The main scientific question was is OSPW a suitable water amendment as freshwater for reclaiming wetland forb habitat? As a surrogate of plant health, we studied plant ecophysiology (gas exchange, leaf fluorescence), leaf chemistry, and plant growth. Results showed that there were no differences in skullcap mineral contents under either treatment; however, mint and smartweed plants subjected to OSPW had a significantly higher Na content than those under freshwater. Smartweed dark-adapted leaf fluorescence showed a reduced photochemistry in OSPW relative to plants in freshwater. Mint leaves exhibited lower stomatal conductance in OSPW than in freshwater, a condition that negatively affected transpiration and carboxylation. Skullcap plants grown in OSPW had lower net CO2 assimilation rates than those in freshwater but did not show any other ecophysiological difference between treatments. Mint plants experienced growth reductions (i.e., shoot height) in OSPW. Our results show, for the first time in the literature, that plants photosynthetic capacity was negatively affected by OSPW. Conditions in OSPW proved to be suitable for establishment as transplanted forbs showed 100 % survival after the first growing season. However, impaired physiological functions in plants subjected to OSPW indicated that OSPW amendment created a less hospitable habitat for wetland forbs than freshwater.

  7. Copper deficiency can limit nitrification in biological rapid sand filters for drinking water production

    DEFF Research Database (Denmark)

    Wagner, Florian Benedikt; Nielsen, Peter Borch; Boe-Hansen, Rasmus

    2016-01-01

    Incomplete nitrification in biological filters during drinking water treatment is problematic, as it compromises drinking water quality. Nitrification problems can be caused by a lack of nutrients for the nitrifying microorganisms. Since copper is an important element in one of the essential...... enzymes in nitrification, we investigated the effect of copper dosing on nitrification in different biological rapid sand filters treating groundwater. A lab-scale column assay with filter material from a water works demonstrated that addition of a trace metal mixture, including copper, increased ammonium...... removal compared to a control without addition. Subsequently, another water works was investigated in full-scale, where copper influent concentrations were below 0.05 μg Cu L-1 and nitrification was incomplete. Copper dosing of less than 5 μg Cu L-1 to a full-scale filter stimulated ammonium removal...

  8. Biannual water-resources review, White Sands Missile Range, New Mexico, 1986 and 1987

    Science.gov (United States)

    Myers, Robert G.; Sharp, Steven C.

    1989-01-01

    Hydrologic data were collected at White Sands Missile Range, New Mexico in 1986 and 1987. The total groundwater withdrawal in 1986 was 565,462,500 gal and in 1987 it was 620,492,000 gal. The total groundwater withdrawal was 110,971,300 gal less in 1986 than in 1985, but 55,029,500 gal more in 1987 than in 1986. Water samples from five Post Headquarters water supply wells were collected for chemical analysis in 1986. In 1987, water samples were collected from four test wells in the Post Headquarters area for analysis of selected volatile organic compounds. Twenty-eight water samples from wells were collected for analysis of specific conductance in 1986 and 1987. (USGS)

  9. Improved waste water treatment by bio-synthesized Graphene Sand Composite.

    Science.gov (United States)

    Poornima Parvathi, V; Umadevi, M; Bhaviya Raj, R

    2015-10-01

    The photocatalytic and antibacterial properties of graphene biosynthesized from sugar and anchored on sand particles has been focused here. The morphology and composition of the synthesized Graphene Sand Composite (GSC) was investigated by means of X-ray powder diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDAX), Fourier Transform Infra-red Spectroscopy (FTIR) and UV-Visible spectroscopy. SEM images show wrinkly edges. This is characteristic of graphenic morphology. Three types of waste water samples namely, textile waste (TW), sugarcane industrial waste water (SW) and domestic waste water from a local purification center at Kodaikanal (KWW) were collected and treated. Adsorption experiments showed effective removal of impurities at 0.2 g of GSC. Photocatalytic activity was analyzed under visible and ultraviolet irradiation. The rate constant for TW increased to 0.0032/min for visible light irradiation from 0.0029/min under UV irradiation. SW showed similar improved activity with rate constant as 0.0023/min in visible irradiation compared to 0.0016/min under UV irradiation. For KWW enhanced activity was seen only in visible light irradiation with rate constant 0.0025/min. GSC showed an inhibition zone of 20 mm against the bacterium Escherichia coli. Results suggest development of economic and effective waste water management systems. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Manganese Coated Sand for Copper (II Removal from Water in Batch Mode

    Directory of Open Access Journals (Sweden)

    Nidal Hilal

    2013-09-01

    Full Text Available Removal of heavy metals, such as copper ions, from water is important to protect human health and the environment. In this study, manganese coated sand (MCS was used as an adsorbent to remove copper ions in a batch system. Equilibrium data were determined at a temperature of 25.6 °C and the Langmuir model was used to describe the experimental data. Mn-coating improved the removal of copper ions by 70% as compared to uncoated sand. Based on a kinetics study, the adsorption of copper ions on MCS was found to occur through a chemisorption process and the pseudo-second-order model was found to fit the kinetics experimental data well. Due to particle interactions, the equilibrium uptake was reduced as the ratio of sand to volume of solution increased. pH affected the removal of copper ions with lowest uptakes found at pH 3 and pHs >7, whilst at pHs in the range of 4 to 7, the uptake was highest and almost constant at the value of 0.0179 mg/g ± 4%. This study has also revealed that copper ions removal was dissolved oxygen (DO dependent with the highest removal occurring at ambient DO concentration, which suggests that DO should be carefully studied when dealing with copper ions adsorption.

  11. Hydrogeochemical contrast between brown and grey sand aquifers in shallow depth of Bengal Basin: consequences for sustainable drinking water supply.

    Science.gov (United States)

    Biswas, Ashis; Nath, Bibhash; Bhattacharya, Prosun; Halder, Dipti; Kundu, Amit K; Mandal, Ujjal; Mukherjee, Abhijit; Chatterjee, Debashis; Mörth, Carl-Magnus; Jacks, Gunnar

    2012-08-01

    Delineation of safe aquifer(s) that can be targeted by cheap drilling technology for tubewell (TW) installation becomes highly imperative to ensure access to safe and sustainable drinking water sources for the arsenic (As) affected population in Bengal Basin. This study investigates the potentiality of brown sand aquifers (BSA) as a safe drinking water source by characterizing its hydrogeochemical contrast to grey sand aquifers (GSA) within shallow depth (water guidelines, which warrants rigorous assessment of attendant health risk for Mn prior to considering mass scale exploitation of the BSA for possible sustainable drinking water supply.

  12. Effects of Different Ultrasound Irradiation Frequencies and Water Temperatures on Extraction Rate of Bitumen from Oil Sand

    Science.gov (United States)

    Okawa, Hirokazu; Saito, Tomonao; Hosokawa, Ryota; Nakamura, Takashi; Kawamura, Youhei; Sugawara, Katsuyasu

    2010-07-01

    Low (28 kHz) and high (200 kHz) frequency sonication combined with hot water treatments at 45 and 75 °C were investigated to assess the effects of different ultrasound frequencies and water temperatures on the extraction of bitumen from oil sand. A mechanical stirrer was also used to compare the efficiency of separation. Bitumen extraction tests were performed under argon, air, and nitrogen atmospheres. Sonication at 200 kHz was shown to extract bitumen effectively from oil sand at 75 °C. The bitumen extraction rate for sonication at 200 kHz was slightly higher than that at 28 kHz. For low temperature (45 °C) solutions, only sonication at 28 kHz could extract bitumen from oil sand, demonstrating that sonication at 28 kHz can effectively breakdown the oil sand aggregates into a suspension.

  13. Evaluating the Metal Tolerance Capacity of Microbial Communities Isolated from Alberta Oil Sands Process Water.

    Directory of Open Access Journals (Sweden)

    Mathew L Frankel

    Full Text Available Anthropogenic activities have resulted in the intensified use of water resources. For example, open pit bitumen extraction by Canada's oil sands operations uses an estimated volume of three barrels of water for every barrel of oil produced. The waste tailings-oil sands process water (OSPW-are stored in holding ponds, and present an environmental concern as they are comprised of residual hydrocarbons and metals. Following the hypothesis that endogenous OSPW microbial communities have an enhanced tolerance to heavy metals, we tested the capacity of planktonic and biofilm populations from OSPW to withstand metal ion challenges, using Cupriavidus metallidurans, a known metal-resistant organism, for comparison. The toxicity of the metals toward biofilm and planktonic bacterial populations was determined by measuring the minimum biofilm inhibitory concentrations (MBICs and planktonic minimum inhibitory concentrations (MICs using the MBEC ™ assay. We observed that the OSPW community and C. metallidurans had similar tolerances to 22 different metals. While thiophillic elements (Te, Ag, Cd, Ni were found to be most toxic, the OSPW consortia demonstrated higher tolerance to metals reported in tailings ponds (Al, Fe, Mo, Pb. Metal toxicity correlated with a number of physicochemical characteristics of the metals. Parameters reflecting metal-ligand affinities showed fewer and weaker correlations for the community compared to C. metallidurans, suggesting that the OSPW consortia may have developed tolerance mechanisms toward metals present in their environment.

  14. Influence of wet activation of used inorganic binder on cyclically refreshed water glass moulding sands hardened by microwaves

    Directory of Open Access Journals (Sweden)

    Mateusz Stachowicz

    2016-11-01

    Full Text Available The paper presents the research results of using an innovative method to reclaim the waste moulding sands containing water glass. Two of the examined processes are connected with "dry" or "wet" activation of inorganic binder in waste moulding sand mixtures physically hardened by microwave radiation. The sand mixtures consisting of high-silica sand and water-glass with average molar module 2.5, were subjected to the following cyclical process: mixing the components, compacting, microwave heating, cooling-down, thermally loading the mould to 800 °C, cooling-down to ambient temperature, and knocking-out. After being knocked-out, the waste moulding sands were subjected to either dry or wet activation of the binder. To activate thermally treated inorganic binder, each of the examined processes employed the surface phenomenon usually associated to mechanical reclamation. The study also covered possible use of some elements of wet reclamation to rehydrate waste binder. To evaluate the effectiveness of the two proposed methods of waste binder activation, selected strength and technological parameters were measured. After each subsequent processing cycle, the permeability, tensile strength and bending strength were determined. In addition, the surface of activated sand grains was examined with a scanning electron microscope. Analysis of the results indicates that it is possible to re-activate the used binder such as sodium silicate, and to stabilize the strength parameters in both activation processes. Permeability of the refreshed moulding sands strongly depends on the surface condition of high-silica grains. The wet activation process by wetting and buffering knocked-out moulding sands in closed humid environment makes it possible to reduce the content of refreshing additive in water-glass. The moulding sands cyclically prepared in both processes do not require the addition of fresh high-silica sand. The relatively high quality achieved in the

  15. Investigating salt and naphthenic acids interactions in the toxicity of oil sands process water to freshwater invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Turcotte, D.; Kautzman, M.; Wojnarowicz, P.; Cutter, J.; Bird, E.; Liber, K. [Saskatchewan Univ., Regina, SK (Canada)

    2010-07-01

    The hot water extraction process used to produce bitumens from oil sands produces a large volume of oil sands process water (OSPW) that contain elevated concentrations of naphthenic acids (NA) and salts. Many oil sands reclamation projects are proposing the use of OSPW as part of reconstructed wetlands projects. This study investigated the toxicity of OSPW to freshwater invertebrates. The toxic interactions between NA and salinity on freshwater invertebrates were assessed. Bioassays with laboratory-cultured Ceriodaphnia dubia were conducted to determine the toxicity of OSPW from selected water bodies. The study showed that while the concentrations of NAs and salinity were elevated in OSPW waters that caused toxic responses, the concentrations of salinity ions varied greatly among the OSPW samples. Results of the study suggested that ion composition may be a factor in toxicity. Interactions between NAs and salinity were then assessed by performing bioassays with mixtures representing major ion combinations in OSPW.

  16. Application of ultrasound and quartz sand for the removal of disinfection byproducts from drinking water.

    Science.gov (United States)

    Yang, Wu; Dong, Lili; Luo, Zhen; Cui, Xiaochun; Liu, Jiancong; Liu, Zhongmou; Huo, Mingxin

    2014-04-01

    To the best of our knowledge, little information is available on the combined use of ultrasound (US) and quartz sand (QS) in the removal of disinfection byproducts (DBPs) from drinking water. This study investigates the removal efficiency for 12 DBPs from drinking water by 20 kHz sonolytic treatment, QS adsorption, and their combination. Results indicate that DBPs with logKow≤1.12 could not be sonolysized; for logKow≥1.97, more than 20% removal efficiency was observed, but the removal efficiency was unrelated to logKow. DBPs containing a nitro group are more sensitive to US than those that comprise nitrile, hydrogen, and hydroxyl groups. Among the 12 investigated DBPs, 9 could be adsorbed by QS adsorption. The adsorption efficiency ranged from 12% for 1,1-dichloro-2-propanone to 80% for trichloroacetonitrile. A synergistic effect was found between the US and QS on DBPs removal, and all the 12 DBPs could be effectively removed by the combined use of US and QS. In the presence of US, part of the QS particles were corroded into small particles which play a role in increasing the number of cavitation bubbles and reducing cavitation bubble size and then improve the removal efficiency of DBPs. On the other hand, the presence of US enhances the DBP mass transfer rate to cavitation bubbles and quartz sand. In addition, sonolytic treatment led to a slight decrease of pH, and TOC values decreased under all the three treatment processes.

  17. Limitation of fluorescence spectrophotometry in the measurement of naphthenic acids in oil sands process water.

    Science.gov (United States)

    Lu, Weibing; Ewanchuk, Andrea; Perez-Estrada, Leonidas; Sego, Dave; Ulrich, Ania

    2013-01-01

    Fluorescence spectrophotometry has been proposed as a quick screening technique for the measurement of naphthenic acids (NAs). To evaluate the feasibility of this application, the fluorescence emission spectra of NAs extracted from three oil sands process water sources were compared with that of commercial NAs. The NAs resulting from the bitumen extraction process cannot be differentiated because of the similarity of the fluorescence spectra. Separation of the fluorescent species in NAs using high performance liquid chromatography with fluorescence detector proved unsuccessful. The acidic fraction of NAs is fluorescent but the basic fraction of NAs is not fluorescent, implying that aromatic acids in NAs give rise to the fluorescent signals. The concentrations of NAs in oil sands process water were measured by Fourier transform infrared spectroscopy (FTIR), fluorescence spectrophotometry and ultra high performance liquid chromatography-time of flight/mass spectrometry (UPLC-TOF/MS). Commercial Merichem and Kodak NAs are the best standards to use when measuring NAs concentration with FTIR and fluorescence spectrophotometry. In addition, the NAs concentrations measured by fluorescence spectrophotometry are about 30 times higher than those measured by FTIR and UPLC-TOF/MS. The findings in this study underscore the limitation of fluorescence spectrophotometry in the measurement of NAs.

  18. Water Flow Investigation on Quartz Sand with 13-interval Stimulated Echo Multi Slice Imaging

    Science.gov (United States)

    Spindler, Natascha; Pohlmeier, Andreas; Galvosas, Petrik

    2011-03-01

    Understanding root water uptake in soils is of high importance for securing nutrition in the context of climate change and linked phenomena like stronger varying weather conditions (draught, strong rain). One step to understand how root water uptake occurs is the knowledge of the water flow in soil towards plant roots. Magnetic Resonance Imaging (MRI) in combination with q-space imaging is potentially the most powerful analytical tool for non-invasive three dimensional visualization of flow and transport in porous media. Numerous attempts have been made to measure local velocity in porous media by combining velocity phase encoding with fast imaging methods, where flow velocities in the vascular bundles of plant stems were investigated. In contrast to water situated in the cellular structure of plants, NMR signal arising from water in the pore space in soil may be much more affected by the presence of internal magnetic field gradients. In this work we account for the existence of these gradients by employing bipolar pulsed field magnetic gradients for velocity encoding. This enables one to study flow through sand (as a model system for soil) at flow rates relevant for the water uptake of plant roots.

  19. Responses of woody species to spatial and temporal ground water changes in coastal sand dune systems

    Directory of Open Access Journals (Sweden)

    C. Máguas

    2011-12-01

    Full Text Available In spite of the relative importance of groundwater in costal dune systems, studies concerning the responses of vegetation to ground water (GW availability variations, particularly in Mediterranean regions, are scarce. Thus, the main purpose of this study is to compare the responses of co-occurring species possessing different functional traits, to changes in GW levels (i.e. the lowering of GW levels in a sand dune ecosystem. For that, five sites were established within a 1 km2 area in a meso-mediterranean sand dune ecosystem dominated by a Pinus pinaster forest. Due to natural topographic variability and anthropogenic GW exploitation, substantial variability in depth to GW between sites was found. Under these conditions it was possible to identify the degree of usage and dependence on GW of different plant species (two deep-rooted trees, a drought adapted shrub, a phreatophyte and a non-native woody invader and how GW dependence varied seasonally and between the heterogeneous sites. Results indicated that the plant species had differential responses to changes in GW depth according to specific functional traits (i.e. rooting depth, leaf morphology, and water use strategy. Species comparison revealed that variability in pre-dawn water potential (Ψpre and bulk leaf δ13C was related to site differences in GW use in the deep-rooted (Pinus pinaster, Myrica faya and phreatophyte (Salix repens species. However, such variation was more evident during spring than during summer drought. The exotic invader, Acacia longifolia, which does not possess a very deep root system, presented the largest seasonal variability in Ψpre and bulk leaf δ13C. In contrast, the response of Corema album, an endemic understory drought-adapted shrub, seemed to be independent of water availability across seasons and sites. Thus, the susceptibility to lowering of GW due to anthropogenic

  20. The Effect of Water Cut on Sand Production%水侵对油井出砂的影响

    Institute of Scientific and Technical Information of China (English)

    张建国

    2001-01-01

    提出了地层出砂过程包括剪切破坏产生屈服区和砂粒运移两个阶段的概念,分析了水侵对油井出砂的影响,水侵加速地层出砂的原因如下:产水能溶解砂粒之间的一部分胶结物,使地层的胶结强度下降;粘土膨胀,渗透率降低;破坏油流的连续性;产生水锁效应,增加油流阻力。同时,建立了粘着力模型,利用该模型分析了水侵量对油井出砂的影响。%It is pointed out in this paper that the sand production includes two steps. The first step is the development of the plastic area induced by the shear failure of the formation. And the second step is that the sand grains are carried by the fluid flow. The effect of the water cut on the sand production is also analyzed. Sand production is increased by the water cut owing to the following reasons: 1. The bonding material among the sand grains is dissolved by the water, which cause the formation strength decrease. 2. The permeability is decreased by clay dilation. 3. The water destroys the oil continuity. 4. The water lock is formed, which increases the fluid flow resistance. Meanwhile, the model to predict the cohesion force is developed. Using this model, the effect of the water cut quantity on the sand production is analyzed.

  1. Microbial metabolism alters pore water chemistry and increases consolidation of oil sands tailings.

    Science.gov (United States)

    Arkell, Nicholas; Kuznetsov, Petr; Kuznetsova, Alsu; Foght, Julia M; Siddique, Tariq

    2015-01-01

    Tailings produced during bitumen extraction from surface-mined oil sands ores (tar sands) comprise an aqueous suspension of clay particles that remain dispersed for decades in tailings ponds. Slow consolidation of the clays hinders water recovery for reuse and retards volume reduction, thereby increasing the environmental footprint of tailings ponds. We investigated mechanisms of tailings consolidation and revealed that indigenous anaerobic microorganisms altered porewater chemistry by producing CO and CH during metabolism of acetate added as a labile carbon amendment. Entrapped biogenic CO decreased tailings pH, thereby increasing calcium (Ca) and magnesium (Mg) cations and bicarbonate (HCO) concentrations in the porewater through dissolution of carbonate minerals. Soluble ions increased the porewater ionic strength, which, with higher exchangeable Ca and Mg, decreased the diffuse double layer of clays and increased consolidation of tailings compared with unamended tailings in which little microbial activity was observed. These results are relevant to effective tailings pond management strategies. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  2. Growth of Chironomus dilutus larvae exposed to ozone-treated and untreated oil sands process water

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, J.; Wiseman, S.; Franz, E.; Jones, P.; Liber, K.; Giesy, J. [Saskatchewan Univ., Saskatoon, SK (Canada); Gamal El-Din, M.; Marin, J. [Alberta Univ., Edmonton, AB (Canada)

    2010-07-01

    Oil sand processing operations require large quantities of freshwater and produce large volumes of oil sands process water (OSPW) which must be stored on-site. This presentation reviewed various treatment methods for remediating OSPW in order to eliminate downstream toxicity. Naphthenic acids are the most important target fractions for treatment because they are primarily responsible for the acute toxicity of OSPW. Although ozonation has shown promise for reducing OSPW toxicity, the effects of ozonation on aquatic invertebrates remain unknown. This study investigated the effects of exposure to untreated and ozonated OSPW in Chironomus dilutus larvae. OSPW was treated with either a 50 or 80 mg O{sub 3}/L dose of ozonation. The effects of ozonation levels on C. dilutus survival and growth were examined. The study showed that after a 10-day exposure, there were pronounced effects on survival of larvae exposed to ozone-treated or untreated OSPW. Larvae exposed to OSPW were 64-77 percent smaller than their respective controls, but the mean wet mass of organisms exposed to 50 mg O{sub 3}/L ozonated OSPW was not much different from that of the controls. Larvae exposed to 80 mg O{sub 3}/L ozone-treated OSPW were 40 percent smaller than the freshwater controls, and the mean wet mass was also much larger than the untreated OSPW. It was concluded that the toxicity of OSPW to benthic invertebrates may be reduced by ozone treatment.

  3. Dissolved organic compounds in reused process water for steam-assisted gravity drainage oil sands extraction.

    Science.gov (United States)

    Kawaguchi, Hideo; Li, Zhengguo; Masuda, Yoshihiro; Sato, Kozo; Nakagawa, Hiroyuki

    2012-11-01

    The in situ oil sands production method called steam-assisted gravity drainage (SAGD) reuses process wastewater following treatment. However, the treatment and reuse processes concentrate contaminants in the process water. To determine the concentration and dynamics of inorganic and organic contaminants, makeup water and process water from six process steps were sampled at a facility employing the SAGD process in Alberta, Canada. In the groundwater used for the makeup water, the total dissolved organic carbon (DOC) content was 4 mg/L. This significantly increased to 508 mg/L in the produced water, followed by a gradual increase with successive steps in subsequent water treatments. The concentrations and dynamics of DOC constituents in the process water determined by gas chromatography-mass spectrometry showed that in the produced water, volatile organic compounds (VOCs) such as acetone (33.1 mg/L) and 2-butanone (13.4 mg/L) predominated, and there were significant amounts of phenolic compounds (total 9.8 mg/L) and organic acids including naphthenic acids (NAs) corresponding to the formula C(n)H(2n+Z)O(X) for combinations of n = 4 to 18, Z = 0 and -2, and X = 2 to 4 (53 mg/L) with trace amounts of polycyclic aromatic hydrocarbons (PAHs) such as naphthalene and phenanthrene. No organic contaminants, except for saturated fatty acids, were detected in the groundwater. The concentration of DOC in the recycled water was 4.4-fold higher than that in the produced water. Likewise, the total concentrations of phenols and organic acids in the recycled water were 1.7- and 4.5-fold higher than in the produced water, whereas the total concentrations of VOCs and PAHs in the recycled water were reduced by over 80%, suggesting that phenols and organic acids are selectively concentrated in the process water treatment. This comprehensive chemical analysis thus identified organic constituents that were concentrated in the process water and which interfere with subsequent

  4. Vibration pore water pressure characteristics of saturated fine sand under partially drained condition

    Institute of Scientific and Technical Information of China (English)

    王炳辉; 陈国兴

    2008-01-01

    Vibration pore water pressure characteristics of saturated fine sand under partially drained condition were investigated through stress-controlled cyclic triaxial tests employed varied fine content of samples and loading frequency. In order to simulate the partially drained condition, one-way drainage for sample was implemented when cyclic loading was applied. The results show that the vibration pore water pressure’s response leads the axial stress and axial strain responses, and is lagged behind or simultaneous with axial strain-rate’s response for all samples in this research. In addition, the satisfactory linear relationship between vibration pore water pressure amplitude and axial strain-rate amplitude is also obtained. It means that the direct cause of vibration pore water pressure generation under partially drained conditions is not the axial stress or axial strain but the axial strain-rate. The lag-phase between pore water pressure and axial strain-rate increases with the increase of the fine content or the loading frequency.

  5. Water repellency and critical soil water content in a dune sand

    NARCIS (Netherlands)

    Dekker, L.W.; Doerr, S.H.; Oostindie, K.; Ziogas, A.K.; Ritsema, C.J.

    2001-01-01

    Assessments of water repellency of soils are commonly made on air-dried or oven-dried samples, without considering the soil water content. The objectives of this study were to examine the spatial and temporal variability of soil water content, actual water repellency over short distances, and the

  6. Influence of obstacles on bubbles rising in water-saturated sand

    Directory of Open Access Journals (Sweden)

    Poryles Raphaël

    2017-01-01

    Full Text Available This work investigates the dynamics of air rising through a water-saturated sand confined in a Hele- Shaw cell in which a circular obstacle is trapped. The air is injected at constant flow rate through a single nozzle at the bottom center of the cell. Without obstacle, in a similar configuration, previous studies pointed out the existence of a fluidized zone generated by the central upward gas motion which entrains two granular convection rolls on its sides. Here, a circular obstacle which diameter is of the order of the central air channel width is trapped at the vertical of the injection nozzle. We analyze the influence of the obstacle location on the size of the fluidized zone and its impact on the morphology of the central air channel. Finally, we quantify the variations of the granular free surface. Two configurations with multiple obstacles are also considered.

  7. A 1-D modelling of streaming potential dependence on water content during drainage experiment in sand

    CERN Document Server

    Allègre, Vincent; Ackerer, Philippe; Jouniaux, Laurence; Sailhac, Pascal; 10.1111/j.1365-246X.2012.05371.x

    2012-01-01

    The understanding of electrokinetics for unsaturated conditions is crucial for numerous of geophysical data interpretation. Nevertheless, the behaviour of the streaming potential coefficient C as a function of the water saturation Sw is still discussed. We propose here to model both the Richards' equation for hydrodynamics and the Poisson's equation for electrical potential for unsaturated conditions using 1-D finite element method. The equations are first presented and the numerical scheme is then detailed for the Poisson's equation. Then, computed streaming potentials (SPs) are compared to recently published SP measurements carried out during drainage experiment in a sand column. We show that the apparent measurement of DV / DP for the dipoles can provide the SP coefficient in these conditions. Two tests have been performed using existing models for the SP coefficient and a third one using a new relation. The results show that existing models of unsaturated SP coefficients C(Sw) provide poor results in term...

  8. Influence of obstacles on bubbles rising in water-saturated sand

    Science.gov (United States)

    Poryles, Raphaël; Varas, Germán; Vidal, Valérie

    2017-06-01

    This work investigates the dynamics of air rising through a water-saturated sand confined in a Hele- Shaw cell in which a circular obstacle is trapped. The air is injected at constant flow rate through a single nozzle at the bottom center of the cell. Without obstacle, in a similar configuration, previous studies pointed out the existence of a fluidized zone generated by the central upward gas motion which entrains two granular convection rolls on its sides. Here, a circular obstacle which diameter is of the order of the central air channel width is trapped at the vertical of the injection nozzle. We analyze the influence of the obstacle location on the size of the fluidized zone and its impact on the morphology of the central air channel. Finally, we quantify the variations of the granular free surface. Two configurations with multiple obstacles are also considered.

  9. Parameterization of Finite-Element Cryo-Hydrologic Sand Dune Model to Constrain Debris-Flow-Initiating Subsurface Temperatures and Pore-Water Pressures, Great Kobuk Sand Dunes, Alaska

    Science.gov (United States)

    Dinwiddie, C. L.; Hooper, D. M.

    2015-05-01

    To explain how debris flows form at subfreezing air temperatures, we present meteorology-driven, numerical simulation-derived subsurface temperature and pore-water pressure profiles in the Great Kobuk Sand Dunes of Alaska, for incipient flow events.

  10. Assessment of water removal from oil sands tailings by evaporation and under-drainage, and the impact on tailings consolidation

    Energy Technology Data Exchange (ETDEWEB)

    Junqueira, Fernando F.; Sanin, Maria Victoria [Golder Associates Ltd (Canada); Sedgwick, Andrea [Total EandP Canada (Canada); Blum, Jim [JG Blum Consulting Ltd (Canada)

    2011-07-01

    Tailings, left-over material produced during the extraction process that separates bitumen from oil sand, are challenging the oil sands industry. These tailings require large surface areas and contain mature fine tailings, made up of fine clay particles suspended in water, which do not settle within a reasonable timeframe. Consequently, maximizing water removal from oil sands tailings is required to accelerate tailings consolidation. The study described in this paper was developed to measure the water loss from oil sands tailings associated with evaporation and under-drainage, using laboratory drying column tests, and to evaluate the impact of water loss on the process of tailings consolidation and the gain in shear strength for different lift thicknesses. Water removal from the tailings through evaporation occurred at a nearly constant rate, while the rate of under-drainage progressively reduced with time. Additionally, it was found that thinner lifts would have better performance in terms of tailings consolidation and gain in shear strength than thick lifts.

  11. Experimental and theoretical modelling of sand-water-object interaction under nonlinear progressive waves

    Science.gov (United States)

    Testik, Firat Yener

    An experimental and theoretical study has been conducted to obtain a fundamental understanding of the dynamics of the sand, water and a solid object interaction as progressive gravity waves impinge on a sloping beach. Aside from obvious scientific interest, this exceedingly complex physical problem is important for naval applications, related to the behavior of disk/cylindrical shaped objects (mines) in the coastal waters. To address this problem, it was divided into a set of simpler basic problems. To begin, nonlinear progressive waves were investigated experimentally in a wave tank for the case of a rigid (impermeable) sloping bottom. Parameterizations for wave characteristics were proposed and compared with the experiments. In parallel, a numerical wave tank model (NWT) was calibrated using experimental data from a single run, and wave field in the wave tank was simulated numerically for the selected experiments. Subsequently, a layer of sand was placed on the slope and bottom topography evolution processes (ripple and sandbar dynamics, bottom topography relaxation under variable wave forcing, etc.) were investigated experimentally. Models for those processes were developed and verified by experimental measurements. Flow over a circular cylinder placed horizontally on a plane wall was also studied. The far-flow field of the cylinder placed in the wave tank was investigated experimentally and numerical results from the NWT simulations were compared with the experimental data. In the mean time, the near-flow velocity/vorticity field around a short cylinder under steady and oscillatory flow was studied in a towing tank. Horseshoe vortex formation and periodic shedding were documented and explained. With the understanding gained through the aforementioned studies, dynamics and burial/scour around the bottom objects in the wave tank were studied. Possible scenarios on the behavior of the disk-shaped objects were identified and explained. Scour around 3D cylindrical

  12. Granular encapsulation of light hydrophobic liquids (LHL) in LHL-salt water systems: Particle induced densification with quartz sand.

    Science.gov (United States)

    Boglaienko, Daria; Tansel, Berrin; Sukop, Michael C

    2016-02-01

    Addition of granular materials to floating crude oil slicks can be effective in capturing and densifying the floating hydrophobic phase, which settles by gravity. Interaction of light hydrophobic liquids (LHL) with quartz sand was investigated in LHL-salt water systems. The LHLs studied were decane, tetradecane, hexadecane, benzene, toluene, ethylbenzene, m-xylene, and 2-cholorotoluene. Experiments were conducted with fine quartz sand (passing sieve No. 40 with openings 0.425 mm). Each LHL was dyed with few crystals of Sudan IV dye for ease of visual observation. A volume of 0.5 mL of each LHL was added to 100 mL salt water (34 g/L). Addition of one gram of quartz sand to the floating hydrophobic liquid layer resulted in formation of sand-encapsulated globules, which settled due to increased density. All LHLs (except for a few globules of decane) formed globules covered with fine sand particles that were heavy enough to settle by gravity. The encapsulated globules were stable and retained their shape upon settling. Polarity of hydrophobic liquids as the main factor of aggregation with minerals was found to be insufficient to explain LHL aggregation with sand. Contact angle measurements were made by submerging a large quartz crystal with the LHL drop on its surface into salt water. A positive correlation was observed between the wetting angle of LHL and the LHL volume captured (r = 0.75). The dependence of the globule density on globule radius was analyzed in relation to the coverage (%) of globule surface (LHL-salt water interface) by fine quartz particles. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Analysis of water and nitrogen use efficiency for maize (Zea mays L.) grown on soft rock and sand compound soil.

    Science.gov (United States)

    Wang, Huanyuan; Han, Jichang; Tong, Wei; Cheng, Jie; Zhang, Haiou

    2017-06-01

    Maize was grown on compound soils constituted from mixtures of soft rock and sand at different ratios, and water use efficiency (WUE), nitrogen use efficiency (NUE) and fertilizer nitrogen use efficiency (FNUE) were quantified. The data were used to assist in designing strategies for optimizing water and nitrogen management practices for maize on the substrates used. Maize was sown in composite soil prepared at three ratios of soft rock and sand (1:1, 1:2 and 1:5 v/v) in Mu Us Sandy Land, Yuyang district, Yulin city, China. Yields, amount of drainage, nitrogen (N) leaching, WUE and NUE were calculated. Then a water and nitrogen management model (WNMM) was calibrated and validated. No significant difference in evapotranspiration of maize was found among compound soils with soft rock/sand ratios of 1:1, 1:2 and 1:5, while water drainage increased significantly with increasing soft rock/sand ratio. WUE increased to 1.30 kg m(-3) in compound soil with 1:2 soft rock/sand ratio. Nitrogen leaching and ammonia volatilization were the main reason for nitrogen loss, and N reduction mainly relied on crop uptake. NUE and FNUE could reach 33.1 and 24.9 kg kg(-1) N respectively. Water drainage and nitrogen leaching occurred mostly during heavy rainfall or irrigation. Through a scenario analysis of different rainfall types, water and fertilizer management systems were formulated each year. This study shows that soft rock plays a key role in improving the WUE, NUE and FNUE of maize. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  14. Endotoxin release from biologically active bench-scale drinking water anthracite/sand filters

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, W.B.; Mayfield, C.I.; Huck, P.M. [University of Waterloo, Waterloo, ON (Canada). Dept. of Civil and Environmental Engineering

    2008-12-15

    Endotoxin release from biologically active dual-media (anthracite/sand) bench-scale drinking water filters was investigated. The biological filters were typically net producers of endotoxin during normal operation with mean concentrations increasing from 6 endotoxin units (EU)/mL to 16 EU/mL in filter influent and effluent, respectively. The filter operating condition resulting in the greatest release of endotoxin occurred upon shutdown and subsequent restart, with the highest observed filter effluent endotoxin concentration being 745 EU/mL in the first pore volume following the return of flow through the filter. Effluent samples collected following filter shutdowns were chlorinated to determine the effect of bacterial cell death on endotoxin release. Chlorination did not induce immediate 'dumping' of endotoxin, nor did holding the chlorinated samples for 5 d result in an increase in aqueous endotoxin concentration. In addition to endotoxin, measurable quantities of potassium were detected in the interstitial water in the biofilter during shutdown periods. In order to reduce potential risk to dialysis patients and humidifier users, it is recommended that, following even short biofilter shutdowns, filters should be immediately backwashed or, failing this, the first five pore volumes of effluent water be discharged to waste to allow endotoxin levels to return to pre-shutdown values.

  15. Effect of liquid distribution on gas-water phase mass transfer in an unsaturated sand during infiltration

    Science.gov (United States)

    Imhoff, Paul T.; Jaffé, Peter R.

    1994-09-01

    Gas-water phase mass transfer was examined in a homogeneous sand with both the gas and water phase mobile: water was infiltrated from the top of the sand column while benzene-laden air flowed upward from the bottom. Mass-transfer limitations for this situation may be important for applications of bioventing, where water and nutrients are added at the ground surface simultaneously with induced air movement to carry oxygen and volatile organics to microbial populations. Gas- and water-phase samples indicate that gas-water phase mass transfer was sufficiently fast that equilibrium between gas and water phases was achieved at all sampling locations within the porous medium. Lower-bound estimates for the gas-water mass-transfer rate coefficient show that mass transfer was at least 10-40 times larger than predictions made from an empirical model developed for gas-water phase mass transfer in an identical porous medium. A water-phase tracer test demonstrates that water flow was much more uniform in this study than in those earlier experiments, which is a likely explanation for the differing rates of gas-water phase mass transfer. It is hypothesized that the liquid distribution in previous laboratory experiments was less uniform because of preferential flow paths due to wetting front instabilities. Gas-water phase mass-transfer rate coefficients reported in this investigation are for an ideal situation of uniform water infiltration: mass-transfer rates in field soils are expected to be significantly smaller.

  16. Arsenic removal from drinking water by a household sand filter in Vietnam--effect of filter usage practices on arsenic removal efficiency and microbiological water quality.

    Science.gov (United States)

    Nitzsche, Katja Sonja; Lan, Vi Mai; Trang, Pham Thi Kim; Viet, Pham Hung; Berg, Michael; Voegelin, Andreas; Planer-Friedrich, Britta; Zahoransky, Jan; Müller, Stefanie-Katharina; Byrne, James Martin; Schröder, Christian; Behrens, Sebastian; Kappler, Andreas

    2015-01-01

    Household sand filters are applied to treat arsenic- and iron-containing anoxic groundwater that is used as drinking water in rural areas of North Vietnam. These filters immobilize poisonous arsenic (As) via co-oxidation with Fe(II) and sorption to or co-precipitation with the formed Fe(III) (oxyhydr)oxides. However, information is lacking regarding the effect of the frequency and duration of filter use as well as of filter sand replacement on the residual As concentrations in the filtered water and on the presence of potentially pathogenic bacteria in the filtered and stored water. We therefore scrutinized a household sand filter with respect to As removal efficiency and the presence of fecal indicator bacteria in treated water as a function of filter operation before and after sand replacement. Quantification of As in the filtered water showed that periods of intense daily use followed by periods of non-use and even sand replacement did not significantly (pwater (95% removal). The first flush of water from the filter contained As concentrations below the drinking water limit and suggests that this water can be used without risk for human health. Colony forming units (CFUs) of coliform bacteria increased during filtration and storage from 5 ± 4 per 100mL in the groundwater to 5.1 ± 1.5 × 10(3) and 15 ± 1.4 × 10(3) per 100mL in the filtered water and in the water from the storage tank, respectively. After filter sand replacement, CFUs of Escherichia coli of samples contained CFUs of Enterococcus spp. No critical enrichment of fecal indicator bacteria belonging to E. coli or Enterococcus spp. was observed in the treated drinking water by qPCR targeting the 23S rRNA gene. The results demonstrate the efficient and reliable performance of household sand filters regarding As removal, but indicate a potential risk for human health arising from the enrichment of coliform bacteria during filtration and from E. coli cells that are introduced by sand replacement.

  17. Influence of dissolved oxygen on silver nanoparticle mobility and dissolution in water-saturated quartz sand

    Energy Technology Data Exchange (ETDEWEB)

    Mittelman, Anjuliee M.; Taghavy, Amir; Wang, Yonggang; Abriola, Linda M.; Pennell, Kurt D., E-mail: kurt.pennell@tufts.edu [Tufts University, Department of Civil and Environmental Engineering (United States)

    2013-07-15

    The influence of dissolved oxygen (DO) on the transport behavior and dissolution kinetics of silver nanoparticles (nAg) was explored through a combination of experimental and mathematical modeling studies. One-dimensional column experiments were conducted with water-saturated 40-50 mesh Ottawa sand, operated at pH 4 or 7 under three DO conditions (8.9, 2, or <0.2 mg/L). The experimental protocol consisted of a nAg deposition phase, designed to assess nanoparticle mobility as a function of DO level, followed by a dissolution phase, to evaluate the release of Ag{sup +} from retained nanoparticles. Experimental observations revealed that the mobility of nAg increased by 15 % when the DO level was reduced from 8.9 to <0.2 mg/L at pH 4, and that, once retained by the quartz sand, the fraction of nAg mass eluted as Ag{sup +} decreased from 21.6 to 13.5 to 11.3 % with decreasing oxygen level (8.9, 2, and <0.2 mg/L, respectively). In both batch and column studies, rates of nAg dissolution decreased over time, behavior attributed to aging of the nanoparticle surface due to oxidation. A hybrid Eulerian-Lagrangian nanoparticle transport model was developed and implemented to simulate the mobility of nAg, subject to DO-dependent dissolution kinetics and particle aging. Model simulations accurately captured nAg transport and dissolution as a function of pH and DO level, and demonstrate the importance of considering nanoparticle surface aging to accurately predict Ag{sup +} release over time.

  18. The use of stable isotopes to trace oil sands constituents

    Energy Technology Data Exchange (ETDEWEB)

    Farwell, A.J.; Nero, V.; Dixon, D.G. [Waterloo Univ., ON (Canada). Dept. of Biology

    2002-07-01

    A study was conducted to determine the biological effects of oil sands mining operations on aquatic ecosystems. The study focused on the Athabasca oil sand deposit, the largest of 4 deposits in northern Alberta. In particular, the study examined the cycling of oil sand constituents in Benthic invertebrates collected from test pits at Syncrude Canada Ltd.. The invertebrates were similar in size, but different in the quantity of process-affected water or mature fine tailings containing residual bitumen. Dragonflies and damselflies in particular, showed trends of depletion for the carbon 13 isotope and enrichment in nitrogen 15 isotope in pits where levels of process affected water was high. The depletion of carbon 13 isotope suggests that oil sand constituents assimilate into the benthic food chain. The greatest carbon 13 depletion, which was approximately 27 per cent, was found to be in test pits with high turbidity. This implies that oil sands constituents degrade microbially instead of by photosynthetic production. All benthic invertebrate group demonstrated an incremental enrichment in nitrogen 15 isotope from the control pit to the pit with greatest levels of mature fine tailings.

  19. The effect of very low water content on the complex dielectric permittivity of clays, sand-clay and sand rocks

    Science.gov (United States)

    Belyaeva, T. A.; Bobrov, P. P.; Kroshka, E. S.; Lapina, A. S.; Rodionova, O. V.

    2017-01-01

    The results of measurements of complex relative permittivity of bentonite and clayey sandstone with different degrees of salinity with low moisture are given in the range of temperatures -20° to  +105 °C at frequencies from 25 Hz to 1 GHz. It is shown, that even a small amount of water in sandy and sandy-argillaceous rocks causes an increase of the real part of complex relative permittivity at frequencies below 100 Hz. The explanation by linearly-broken dependence of refractive index on moisture is given at its small values. By a dielectric method it is shown that in the process of water film formation on the surface of a mineral, the water molecules binding energy changes. Big distinctions in low-frequency dielectric relaxation times testify to the change of binding energy of molecules of water on the surface of a mineral. Also dependences of relaxation times on temperature are various. The results of dielectric measurements showed a strong influence of the salt on the dielectric permittivity of the clay and clayey sandstone even at a low moisture level.

  20. Optimizing nitrification in biological rapid sand filters for drinking water production

    DEFF Research Database (Denmark)

    Albrechtsen, Hans-Jørgen; Smets, Barth F.; Lee, Carson Odell

    Addition of phosphate or trace metals or better management e.g. in terms of anmonium load can improve the nitrification rate and efficiency in biological rapid sand filters.......Addition of phosphate or trace metals or better management e.g. in terms of anmonium load can improve the nitrification rate and efficiency in biological rapid sand filters....

  1. Modeling the Performance of Biological Rapid Sand Filters Used to Remove Ammonium, Iron, and Manganese From Drinking Water

    DEFF Research Database (Denmark)

    Lee, Carson; Albrechtsen, Hans-Jørgen; Smets, Barth F.;

    filter management to performance . Biological rapid sand filters are used for the dual purpose of particle removal (including microorganisms) and contaminant removal through biological activity on the filter media. For drinking water treatment in the United States, biological filters use granular......Although biological rapid sand filters are a well established technology for treating drinking water, there is still a lack of scientific understanding of the processes controlling their performance. For example, the distribution and role of microorganisms in contaminant removal in the filter has...... for chlorine addition following treatment. Under the normal conditions found in many water treatment plants, reduced iron can be oxidized through aeration and the precipitates can be captured by the filter media. Ammonium and manganese can be removed biologically. This research uses both pilot and full scale...

  2. Monitoring degradation of oil sands constituents and foodweb dynamics in aquatic reclamation using stable isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Farwell, A.J.; Butler, B.J.; Dixon, D.G. [Waterloo Univ., ON (Canada). Dept. of Biology; Mackinnon, M.D. [Syncrude Canada Ltd., Edmonton, AB (Canada)

    2003-07-01

    The process of extracting bitumen from the Athabasca oil sands deposits in northern Alberta generates large volumes of process-affected water with highly toxic constituents such as naphthenic acids. Napthenic acids can biodegrade and become less toxic in reclaimed aquatic systems. This study used stable isotopes to examine the cycling of oil sands constituents in aquatic systems. Benthic invertebrates were collected from test pits at Syncrude Canada Ltd. Dragonflies and damselflies showed trends in carbon 13 depletion and nitrogen 15 enrichment in pits with high levels of process-affected water. Chironomids and amphipods showed only nitrogen 15 enrichment. Carbon 13 depletion suggests invertebrate assimilation and incorporation of oil sands constituents through the microbial foodweb. It is important to define the isotope pathway of naphthenic acid degradation because naphthenic acids could represent a major source of carbon in reclaimed systems.

  3. Next-Generation Sequencing Assessment of Eukaryotic Diversity in Oil Sands Tailings Ponds Sediments and Surface Water.

    Science.gov (United States)

    Aguilar, Maria; Richardson, Elisabeth; Tan, BoonFei; Walker, Giselle; Dunfield, Peter F; Bass, David; Nesbø, Camilla; Foght, Julia; Dacks, Joel B

    2016-11-01

    Tailings ponds in the Athabasca oil sands (Canada) contain fluid wastes, generated by the extraction of bitumen from oil sands ores. Although the autochthonous prokaryotic communities have been relatively well characterized, almost nothing is known about microbial eukaryotes living in the anoxic soft sediments of tailings ponds or in the thin oxic layer of water that covers them. We carried out the first next-generation sequencing study of microbial eukaryotic diversity in oil sands tailings ponds. In metagenomes prepared from tailings sediment and surface water, we detected very low numbers of sequences encoding eukaryotic small subunit ribosomal RNA representing seven major taxonomic groups of protists. We also produced and analysed three amplicon-based 18S rRNA libraries prepared from sediment samples. These revealed a more diverse set of taxa, 169 different OTUs encompassing up to eleven higher order groups of eukaryotes, according to detailed classification using homology searching and phylogenetic methods. The 10 most abundant OTUs accounted for > 90% of the total of reads, vs. large numbers of rare OTUs (tailings ponds harbour complex communities of microbial eukaryotes indicating that these organisms should be taken into account when studying the microbiology of the oil sands. © 2016 The Author(s) Journal of Eukaryotic Microbiology © 2016 International Society of Protistologists.

  4. Processes affecting the remediation of chromium-contaminated sites.

    OpenAIRE

    Palmer, C.D.; Wittbrodt, P R

    1991-01-01

    The remediation of chromium-contaminated sites requires knowledge of the processes that control the migration and transformation of chromium. Advection, dispersion, and diffusion are physical processes affecting the rate at which contaminants can migrate in the subsurface. Heterogeneity is an important factor that affects the contribution of each of these mechanisms to the migration of chromium-laden waters. Redox reactions, chemical speciation, adsorption/desorption phenomena, and precipitat...

  5. Chemical mass transport between fluid fine tailings and the overlying water cover of an oil sands end pit lake

    Science.gov (United States)

    Dompierre, Kathryn A.; Barbour, S. Lee; North, Rebecca L.; Carey, Sean K.; Lindsay, Matthew B. J.

    2017-06-01

    Fluid fine tailings (FFT) are a principal by-product of the bitumen extraction process at oil sands mines. Base Mine Lake (BML)—the first full-scale demonstration oil sands end pit lake (EPL)—contains approximately 1.9 × 108 m3 of FFT stored under a water cover within a decommissioned mine pit. Chemical mass transfer from the FFT to the water cover can occur via two key processes: (1) advection-dispersion driven by tailings settlement; and (2) FFT disturbance due to fluid movement in the water cover. Dissolved chloride (Cl) was used to evaluate the water cover mass balance and to track mass transport within the underlying FFT based on field sampling and numerical modeling. Results indicated that FFT was the dominant Cl source to the water cover and that the FFT is exhibiting a transient advection-dispersion mass transport regime with intermittent disturbance near the FFT-water interface. The advective pore water flux was estimated by the mass balance to be 0.002 m3 m-2 d-1, which represents 0.73 m of FFT settlement per year. However, the FFT pore water Cl concentrations and corresponding mass transport simulations indicated that advection rates and disturbance depths vary between sample locations. The disturbance depth was estimated to vary with location between 0.75 and 0.95 m. This investigation provides valuable insight for assessing the geochemical evolution of the water cover and performance of EPLs as an oil sands reclamation strategy.

  6. Evaluating the reliability of equilibrium dissolution assumption from residual gasoline in contact with water saturated sands

    Science.gov (United States)

    Lekmine, Greg; Sookhak Lari, Kaveh; Johnston, Colin D.; Bastow, Trevor P.; Rayner, John L.; Davis, Greg B.

    2017-01-01

    Understanding dissolution dynamics of hazardous compounds from complex gasoline mixtures is a key to long-term predictions of groundwater risks. The aim of this study was to investigate if the local equilibrium assumption for BTEX and TMBs (trimethylbenzenes) dissolution was valid under variable saturation in two dimensional flow conditions and evaluate the impact of local heterogeneities when equilibrium is verified at the scale of investigation. An initial residual gasoline saturation was established over the upper two-thirds of a water saturated sand pack. A constant horizontal pore velocity was maintained and water samples were recovered across 38 sampling ports over 141 days. Inside the residual NAPL zone, BTEX and TMBs dissolution curves were in agreement with the TMVOC model based on the local equilibrium assumption. Results compared to previous numerical studies suggest the presence of small scale dissolution fingering created perpendicular to the horizontal dissolution front, mainly triggered by heterogeneities in the medium structure and the local NAPL residual saturation. In the transition zone, TMVOC was able to represent a range of behaviours exhibited by the data, confirming equilibrium or near-equilibrium dissolution at the scale of investigation. The model locally showed discrepancies with the most soluble compounds, i.e. benzene and toluene, due to local heterogeneities exhibiting that at lower scale flow bypassing and channelling may have occurred. In these conditions mass transfer rates were still high enough to fall under the equilibrium assumption in TMVOC at the scale of investigation. Comparisons with other models involving upscaled mass transfer rates demonstrated that such approximations with TMVOC could lead to overestimate BTEX dissolution rates and underestimate the total remediation time.

  7. Elemental and spectroscopic characterization of fractions of an acidic extract of oil sands process water.

    Science.gov (United States)

    Jones, D; Scarlett, A G; West, C E; Frank, R A; Gieleciak, R; Hager, D; Pureveen, J; Tegelaar, E; Rowland, S J

    2013-11-01

    'Naphthenic acids' (NAs) in petroleum produced water and oil sands process water (OSPW), have been implicated in toxicological effects. However, many are not well characterized. A method for fractionation of NAs of an OSPW was used herein and a multi-method characterization of the fractions conducted. The unfractionated OSPW acidic extract was characterized by elemental analysis, electrospray ionization-Orbitrap-mass spectrometry (ESI-MS), and an esterified extract by Fourier Transform infrared (FTIR) and ultraviolet-visible (UV) absorption spectroscopy and by comprehensive multidimensional gas chromatography-MS (GCxGC-MS). Methyl esters were fractionated by argentation solid phase extraction (Ag(+) SPE) and fractions eluting with: hexane; diethyl ether: hexane and diethyl ether, examined. Each was weighed, examined by elemental analysis, FTIR, UV, GC-MS and GCxGC-MS (both nominal and high resolution MS). The ether fraction, containing sulfur, was also examined by GCxGC-sulfur chemiluminescence detection (GCxGC-SCD). The major ions detected by ESI-MS in the OSPW extract were assigned to alicyclic and aromatic 'O2' acids; sulfur was also present. Components recovered by Ag(+) SPE were also methyl esters of alicyclic and aromatic acids; these contained little sulfur or nitrogen. FTIR spectra showed that hydroxy acids and sulfoxides were absent or minor. UV spectra, along with the C/H ratio, further confirmed the aromaticity of the hexane:ether eluate. The more minor ether eluate contained further aromatics and 1.5% sulfur. FTIR spectra indicated free carboxylic acids, in addition to esters. Four major sulfur compounds were detected by GCxGC-SCD. GCxGC-high resolution MS indicated these were methyl esters of C18 S-containing, diaromatics with ≥C3 carboxylic acid side chains. Copyright © 2013 Crown Copyright and Elsevier Ltd. Published by Elsevier Ltd.. All rights reserved.

  8. Sand box experiments to evaluate the influence of subsurface temperature probe design on temperature based water flux calculation

    Directory of Open Access Journals (Sweden)

    M. Munz

    2011-06-01

    Full Text Available Quantification of subsurface water fluxes based on the one dimensional solution to the heat transport equation depends on the accuracy of measured subsurface temperatures. The influence of temperature probe setup on the accuracy of vertical water flux calculation was systematically evaluated in this experimental study. Four temperature probe setups were installed into a sand box experiment to measure temporal highly resolved vertical temperature profiles under controlled water fluxes in the range of ±1.3 m d−1. Pass band filtered time series provided amplitude and phase of the diurnal temperature signal varying with depth depending on water flux. Amplitude ratios of setups directly installed into the saturated sediment significantly varied with sand box hydraulic gradients. Amplitude ratios provided an accurate basis for the analytical calculation of water flow velocities, which matched measured flow velocities. Calculated flow velocities were sensitive to thermal properties of saturated sediment and to probe distance, but insensitive to thermal dispersivity equal to solute dispersivity. Amplitude ratios of temperature probe setups indirectly installed into piezometer pipes were influenced by thermal exchange processes within the pipes and significantly varied with water flux direction only. Temperature time lags of small probe distances of all setups were found to be insensitive to vertical water flux.

  9. Cyclic formation and dissociation of methane hydrate within partially water saturated sand

    Science.gov (United States)

    Kneafsey, T. J.; Nakagawa, S.

    2010-12-01

    For partially water-saturated sediments, laboratory experiments have shown that methane hydrate forms heterogeneously within a sample at the core scale. The heterogeneous distribution of hydrate in combination with grain-scale hydrate location (eg. grain cementing, load bearing, and pore filling), determines the overall mechanical properties of hydrate-bearing sediments including shear strength and seismic properties. For this reason, understanding the heterogeneity of hydrate-bearing sample is essential when the bulk properties of the sample are examined in the laboratory. We present a series of laboratory methane hydrate formation and dissociation experiments with concurrent x-ray CT imaging and low-frequency (near 1 kHz) seismic measurements. The seismic measurements were conducted using a new acoustic resonant bar technique called the Split Hopkinson Resonant Bar method, which allows using a small sediment core (3.75 cm diameter, 7.5 cm length). The experiment was conducted using a jacketed, pre-compacted, fine-grain silica sand sample with a 40% distilled water saturation. Under isotropic confining stress of 6.9 MPa and a temperature 4 oC, the hydrate was formed in the sample by injecting pure methane gas at 5.6 MPa. Once the hydrate formed, it was dissociated by reducing the pore pressure to 2.8 MPa. This cycle was repeated by three times (dissociation test for the third cycle was not done) to examine the resulting changes in the hydrate distribution and seismic signatures. The repeated formation of hydrate resulted in significant changes in its distribution, which resulted in differences in the overall elastic properties of the sample, determined from the seismic measurements. Interestingly, the time intervals between the dissociation and subsequent formation of hydrate affected the rate of hydrate formation, shorter intervals resulting in faster formation. This memory effect, possibly caused by the presence of residual “seed crystals” in the pore water

  10. Effect of hardening method and structure of linking bridges on strength of water glass moulding sands

    Directory of Open Access Journals (Sweden)

    M. Stachowicz

    2010-04-01

    Full Text Available The paper presents examination results of the effect of four hardening methods on structure of linking bridges in sandmixes containing hydrated sodium silicate. Test pieces prepared of the moulding sands containing 2.5 % of a binder with molar module between 2.4 and 2.6 were hardened with carbon dioxide, dried traditionally in an oven and hardened with microwaves at 2.54 GHz or using a combination of the CO2 process and microwave heating. It was revealed that the hardening method influences structure of linking bridges and is correlated with mechanical properties of the hardened moulding sands. It was found that strength of the moulding sands microwave-heated for 240 s is approximate to that measured after traditional drying for 120 min at 110 °C. So, the microwave hardening permits significant reduction of the process time, comparable to the CO2 hardening, at the same time guaranteeing over 10 times higher mechanical properties. Analysis of SEM photographs of the moulding sands hardened with the mentioned methods allow explaining differences in qualitative parameters of the moulding sands and their relation to structures of the created linking bridges.

  11. Impulse Loading Resulting fromShallow Buried Explosives in Water-Saturated Sand

    Science.gov (United States)

    2007-01-01

    stress due to moisture-induced inter-particle lubrication effects, which limits the extent of sand ejection. It should be recalled that the behaviour of...Con- gress, Detroit, April 2005. 24 Van der Veen, W. A. Simulation of a compartmented airbag deployment using an explicit, coupled euler/ Lagrange

  12. Rice straw biochar affects water retention and air movement in a sand-textured tropical soil

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Ahmed, Fauziatu

    2017-01-01

    Despite the current global attention on biochar (BC) as a soil amendment, knowledge is limited on how BC impacts the physical properties of coarse-textured soils (sand > 95%), particularly in tropical regions. A two-season field-study was conducted to investigate the effect of rice straw BC (3% w...

  13. Are there toxic interactions between salinity and naphthenic acids in the toxicity of oil sands process water to freshwater invertebrates?

    Energy Technology Data Exchange (ETDEWEB)

    Turcotte, D.; Pasloski, A.; Lanser, B.; Alm, K.; Liber, K. [Saskatchewan Univ., Saskatoon, SK (Canada)

    2009-07-01

    Large volumes of water are used to extract oil from the oil sands in the Athabasca deposit. The resulting oil sands process water (OSPW) has been proposed for use in future reclamation landscapes. Therefore, it is necessary to evaluate the toxicity of OSPW to freshwater invertebrates in order to develop environmentally acceptable OSPW reclamation plans. The OSPW generally contains high concentrations of salts and naphthenic acids (NAs), but low levels of other contaminants such as PAHs and metals. This study investigated the combined toxic effect of NAs and salinity on freshwater invertebrates. Laboratory cultured Ceriodaphnia dubia were used initially to determine the toxicity of OSPW from selected water bodies. The pond waters that generated a toxic response had elevated levels of NAs and salinity, but the concentrations of salinity ions varied considerably among ponds. Results suggested that ion composition may be a factor in toxicity. Subsequent bioassays were performed with single salts and with mixtures representing major ion combinations present in the OSPW, such as carbonate, sulphate, chloride and sodium. The interaction between NAs and salinity was evaluated by exposing Ceriodaphnia dubia and Daphnia pulex to mixtures of NAs extracted from OSPW and relevant major ions chosen according to the salt toxicity test results.

  14. Development of water quality objectives and management systems for the lower Athabasca River in the oil sands area

    Energy Technology Data Exchange (ETDEWEB)

    Noton, L. [Alberta Environment, Edmonton, AB (Canada). Water Quality; McEachern, P. [Alberta Environment, Edmonton, AB (Canada). Regional Environmental Management

    2004-07-01

    This paper addressed environmental concerns related to the increased oil sands activity along the lower Athabasca River in northeastern Alberta. The concerns include potential effects on water quality of the river even though wastewaters do not currently reach the Athabasca River, nor do they have any significant effects. However, as the industry expands, there is concern that releases of wastewater may increase significantly. A multi-stakeholder group called the Cumulative Environmental Management Association (CEMA) has addressed some of these environmental management issues in the Athabasca area by establishing a water quality task group that examines water quality protection and management activities. The task group intends to develop and recommend water quality objectives and management options on the lower Athabasca River. Their 4 part process includes: (1) defining the problem, (2) setting goals, (3) measuring performance, and (4) managing and adapting to potential impacts. The group has identified and defined about 35 water quality variables of potential concern. It has also identified the uses of water it wants to protect and intends to prevent the degradation of water quality. A plan for developing site specific water quality objectives has been established following a review of water quality guidelines. Performance will be measured using water quality models that simulate full development scenarios. The modelling work will be instrumental in designing management schemes for any potential impacts.

  15. Integrated Metagenomic and Physiochemical Analyses to Evaluate the Potential Role of Microbes in the Sand Filter of a Drinking Water Treatment System

    Science.gov (United States)

    Bai, Yaohui; Liu, Ruiping; Liang, Jinsong; Qu, Jiuhui

    2013-01-01

    While sand filters are widely used to treat drinking water, the role of sand filter associated microorganisms in water purification has not been extensively studied. In the current investigation, we integrated molecular (based on metagenomic) and physicochemical analyses to elucidate microbial community composition and function in a common sand filter used to treat groundwater for potable consumption. The results revealed that the biofilm developed rapidly within 2 days (reaching ∼1011 prokaryotes per gram) in the sand filter along with abiotic and biotic particulates accumulated in the interstitial spaces. Bacteria (up to 90%) dominated the biofilm microbial community, with Alphaproteobacteria being the most common class. Thaumarchaeota was the sole phylum of Archaea, which might be involved in ammonia oxidation. Function annotation of metagenomic datasets revealed a number of aromatic degradation pathway genes, such as aromatic oxygenase and dehydrogenase genes, in the biofilm, suggesting a significant role for microbes in the breakdown of aromatic compounds in groundwater. Simultaneous nitrification and denitrification pathways were confirmed as the primary routes of nitrogen removal. Dissolved heavy metals in groundwater, e.g. Mn2+ and As3+, might be biologically oxidized to insoluble or easily adsorbed compounds and deposited in the sand filter. Our study demonstrated that the role of the microbial community in the sand filter treatment system are critical to effective water purification in drinking water. PMID:23593378

  16. Integrated metagenomic and physiochemical analyses to evaluate the potential role of microbes in the sand filter of a drinking water treatment system.

    Directory of Open Access Journals (Sweden)

    Yaohui Bai

    Full Text Available While sand filters are widely used to treat drinking water, the role of sand filter associated microorganisms in water purification has not been extensively studied. In the current investigation, we integrated molecular (based on metagenomic and physicochemical analyses to elucidate microbial community composition and function in a common sand filter used to treat groundwater for potable consumption. The results revealed that the biofilm developed rapidly within 2 days (reaching ≈ 10(11 prokaryotes per gram in the sand filter along with abiotic and biotic particulates accumulated in the interstitial spaces. Bacteria (up to 90% dominated the biofilm microbial community, with Alphaproteobacteria being the most common class. Thaumarchaeota was the sole phylum of Archaea, which might be involved in ammonia oxidation. Function annotation of metagenomic datasets revealed a number of aromatic degradation pathway genes, such as aromatic oxygenase and dehydrogenase genes, in the biofilm, suggesting a significant role for microbes in the breakdown of aromatic compounds in groundwater. Simultaneous nitrification and denitrification pathways were confirmed as the primary routes of nitrogen removal. Dissolved heavy metals in groundwater, e.g. Mn(2+ and As(3+, might be biologically oxidized to insoluble or easily adsorbed compounds and deposited in the sand filter. Our study demonstrated that the role of the microbial community in the sand filter treatment system are critical to effective water purification in drinking water.

  17. Case study : evaluation of oilfield and water well disposal well designs for oil sands facility in northern Alberta, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Champollion, Y.; Gleixner, M.R.; Wozniewicz, J. [Golder Associates Ltd., Calgary, AB (Canada); MacFarlane, W.D.; Skulski, L. [Nexen Canada Ltd., Calgary, AB (Canada)

    2003-07-01

    Large volumes of wastewater disposal capacity will be required for the production of bitumen at the Long Lake Project, located in northeastern Alberta. An unconsolidated sand aquifer is the target formation for disposal. An evaluation of two disposal well designs, perforated casing (standard oil and gas approach), and wire-wound telescopic screen (standard water well approach) was performed. Skin, transmissivity and storability were the hydraulic parameters quantified. Full superposition type curves were used to conduct the transient analysis, along with the use of pressure derivative data. The results from the injection tests revealed that the sand aquifer at the Long Lake Project had suitable aquifer disposal capacity. The test results also revealed that clogging takes place in the vicinity of the wellbore, probably because of suspended solids in the injection water and the degassing effects. The water well design, as opposed to the standard oilfields well, makes provision for less costly re-development during operations, something that might be required if clogging problems occur. 3 refs., 8 figs.

  18. The formation and migration of sand ripples in closed conduits: experiments with turbulent water flows

    CERN Document Server

    Florez, Jorge Eduar Cardona

    2016-01-01

    The transport of solid particles by a fluid flow is frequently found in nature and industry. Some examples are the transport of sand in rivers and hydrocarbon pipelines. When the shear stresses exerted by a fluid flow on a granular bed remain moderate, some grains are set in motion without fluidizing the bed; the moving grains form a layer, known as bed load, that moves while maintaining contact with the fixed part of the bed. Under bed load conditions, the granular bed may become unstable, generating ripples and dunes. Sand ripples are commonly observed in closed conduits and pipes such as in petroleum pipelines, sewer systems, and dredging lines. Although of importance for many scientific domains and industrial applications, the formation of ripples in closed conduits is not well understood, and the problem is still open. This paper presents an experimental study on the formation and migration of sand ripples under a turbulent closed-conduit flow and bed-load conditions. In our experiments, fully-developed ...

  19. Pharmaceuticals, perfluorosurfactants, and other organic wastewater compounds in public drinking water wells in a shallow sand and gravel aquifer.

    Science.gov (United States)

    Schaider, Laurel A; Rudel, Ruthann A; Ackerman, Janet M; Dunagan, Sarah C; Brody, Julia Green

    2014-01-15

    Approximately 40% of U.S. residents rely on groundwater as a source of drinking water. Groundwater, especially unconfined sand and gravel aquifers, is vulnerable to contamination from septic systems and infiltration of wastewater treatment plant effluent. In this study, we characterized concentrations of pharmaceuticals, perfluorosurfactants, and other organic wastewater compounds (OWCs) in the unconfined sand and gravel aquifer of Cape Cod, Massachusetts, USA, where septic systems are prevalent. Raw water samples from 20 public drinking water supply wells on Cape Cod were tested for 92 OWCs, as well as surrogates of wastewater impact. Fifteen of 20 wells contained at least one OWC; the two most frequently-detected chemicals were sulfamethoxazole (antibiotic) and perfluorooctane sulfonate (perfluorosurfactant). Maximum concentrations of sulfamethoxazole (113 ng/L) and the anticonvulsant phenytoin (66 ng/L) matched or exceeded maximum reported concentrations in other U.S. public drinking water sources. The sum of pharmaceutical concentrations and the number of detected chemicals were both significantly correlated with nitrate, boron, and extent of unsewered residential and commercial development within 500 m, indicating that wastewater surrogates can be useful for identifying wells most likely to contain OWCs. Septic systems appear to be the primary source of OWCs in Cape Cod groundwater, although wastewater treatment plants and other sources were potential contributors to several wells. These results show that drinking water supplies in unconfined aquifers where septic systems are prevalent may be among the most vulnerable to OWCs. The presence of mixtures of OWCs in drinking water raises human health concerns; a full evaluation of potential risks is limited by a lack of health-based guidelines and toxicity assessments.

  20. Fontainebleau Sand

    DEFF Research Database (Denmark)

    Leth, Caspar Thrane

    2006-01-01

    The report is a summary of results from laboratory tests in the geotechncial research group on Fontainebleau sand.......The report is a summary of results from laboratory tests in the geotechncial research group on Fontainebleau sand....

  1. The substitution of sand filtration by immersed-UF for surface water treatment: pilot-scale studies.

    Science.gov (United States)

    Lihua, Sun; Xing, Li; Guoyu, Zhang; Jie, Chen; Zhe, Xu; Guibai, Li

    2009-01-01

    The newly issued National Drinking Water Standard required that turbidity should be lower than 1 NTU, and the substitution of sand filtration by immersed ultrafiltration (immersed-UF) is feasible to achieve the standard. This study aimed to optimise the operational processes (i.e. aeration, backwashing) through pilot scale studies, to control membrane fouling while treating the sedimentation effluent. Results indicated that the immersed-UF was promising to treat the sedimentation effluent. The turbidity was below 0.10 NTU, bacteria and E. coli were not detected in the permeate water. The intermittent filtration with aeration is beneficial to inhibit membrane fouling. The critical aeration intensity is observed to be 60.0 m(3) m(-2) h(-1). At this aeration intensity, the decline rate of permeate flux in one period of backwashing was 1.94% and 7.03% for intermittent filtration and sustained filtration respectively. The different membrane backwashing methods (i.e. aeration 1.5 min, synchronous aeration and water backwashing 2 min, water backwashing 1.5 min; synchronous aeration and water backwashing 3 min, water backwashing 2 min; aeration 3 min, single water backwashing 2 min; synchronous aeration and water backwashing 5 min; single water backwashing 5 min) on the recovery of permeate flux were compared, indicating that the synchronous aeration and water backwashing exhibited best potential for permeate flux recovery. The optimal intensity of water backwashing is shown to be 90.0 L m(-2) h(-1). When the actual water intensity was below or exceeded the value, the recovery rate of permeate flux would be reduced. Additionally, the average operating cost for the immersed UF membrane, including the power, the chemical cleaning reagents, and membrane modules replacement, was about 0.31 RMB/m(3).

  2. Effect of hardening method and structure of linking bridges on strength of water glass moulding sands

    OpenAIRE

    Stachowicz, M.; K. Granat

    2010-01-01

    The paper presents examination results of the effect of four hardening methods on structure of linking bridges in sandmixes containing hydrated sodium silicate. Test pieces prepared of the moulding sands containing 2.5 % of a binder with molar module between 2.4 and 2.6 were hardened with carbon dioxide, dried traditionally in an oven and hardened with microwaves at 2.54 GHz or using a combination of the CO2 process and microwave heating. It was revealed that the hardening method influences s...

  3. Evaluation of the Impact of the Plastic BioSand Filter on Health and Drinking Water Quality in Rural Tamale, Ghana

    OpenAIRE

    Mumuni K. Osman; Stauber, Christine E.; Byron Kominek; Liang, Kaida R.; Sobsey, Mark D.

    2012-01-01

    A randomized controlled trial of the plastic BioSand filter (BSF) was performed in rural communities in Tamale (Ghana) to assess reductions in diarrheal disease and improvements in household drinking water quality. Few studies of household water filters have been performed in this region, where high drinking water turbidity can be a challenge for other household water treatment technologies. During the study, the longitudinal prevalence ratio for diarrhea comparing households that received th...

  4. Tar sand

    Energy Technology Data Exchange (ETDEWEB)

    McLendon, T.R.; Bartke, T.C.

    1990-01-01

    Research on tar sand is briefly discussed. The research program supported by the US Department of Energy (DOE) includes a variety of surface extraction schemes. The University of Utah has process development units (PDU) employing fluidized bed, hot, water-assisted, and fluidized-bed/heat-pipe, coupled combustor technology. Considerable process variable test data have been gathered on these systems: (1) a rotary kiln unit has been built recently; (2) solvent extraction processing is being examined; and (3) an advanced hydrogenation upgrading scheme (hydropyrolysis) has been developed. The University of Arkansas, in collaboration with Diversified Petroleum, Inc., has been working on a fatty acid, solvent extraction process. Oleic acid is the solvent/surfactant. Solvent is recovered by adjusting processing fluid concentrations to separate without expensive operations. Western Research Institute has a PDU-scale scheme called the Recycle Oil Pyrolysis and Extraction (ROPE) process, which combines solvent (hot recycle bitumen) and pyrolytic extraction. 14 refs., 19 figs.

  5. Conditions and processes affecting radionuclide transport

    Science.gov (United States)

    Simmons, Ardyth M.; Neymark, Leonid A.

    2012-01-01

    Characteristics of host rocks, secondary minerals, and fluids would affect the transport of radionuclides from a previously proposed repository at Yucca Mountain, Nevada. Minerals in the Yucca Mountain tuffs that are important for retarding radionuclides include clinoptilolite and mordenite (zeolites), clay minerals, and iron and manganese oxides and hydroxides. Water compositions along flow paths beneath Yucca Mountain are controlled by dissolution reactions, silica and calcite precipitation, and ion-exchange reactions. Radionuclide concentrations along flow paths from a repository could be limited by (1) low waste-form dissolution rates, (2) low radionuclide solubility, and (3) radionuclide sorption onto geological media.

  6. The effects of ground-water development on the water supply in the Post Headquarters area, White Sands Missile Range, New Mexico

    Science.gov (United States)

    Kelly, T.E.; Hearne, Glenn A.

    1976-01-01

    Water-level declines in the Post Headquarters area, White Sands Missile Range, N. Mex., have been accompanied by slight but progressive increases in the concentration of dissolved solids in water withdrawn from the aquifer. Projected water-level declines through 1996 are estimated from a digital simulation model to not exceed 200 feet (61 metres). A conceptual model of water quality provides three potential sources for water that is relatively high in dissolved solids: brine from the Tularosa Basin to the east, slightly saline water beneath the subjacent aquatard, and very slightly saline water from the less permeable units within the aquifer itself. Management of the well field to minimize drawdown and spread the cone of depression would minimize the rate of water-quality deterioration. A well designed monitoring network may provide advance warning of severe or rapid water-quality deterioration.. The Soledad Canyon area 10 miles (16.1 kilometres) south of the Post Headquarters offers the greatest potential for development of additional water supplies.

  7. Antimicrobial Susceptibility of Staphylococcus aureus Isolated from Recreational Waters and Beach Sand in Eastern Cape Province of South Africa.

    Science.gov (United States)

    Akanbi, Olufemi Emmanuel; Njom, Henry Akum; Fri, Justine; Otigbu, Anthony C; Clarke, Anna M

    2017-09-01

    Background: Resistance of Staphylococcus aureus to commonly used antibiotics is linked to their ability to acquire and disseminate antimicrobial-resistant determinants in nature, and the marine environment may serve as a reservoir for antibiotic-resistant bacteria. This study determined the antibiotic sensitivity profile of S.aureus isolated from selected beach water and intertidal beach sand in the Eastern Cape Province of South Africa. Methods: Two hundred and forty-nine beach sand and water samples were obtained from 10 beaches from April 2015 to April 2016. Staphylococcus aureus was isolated from the samples using standard microbiological methods and subjected to susceptibility testing to 15 antibiotics. Methicillin-resistant Staphylococcus aureus (MRSA) was detected by susceptibility to oxacillin and growth on Brilliance MRSA II agar. Antibiotic resistance genes including mecA, femA rpoB, blaZ, ermB, ermA, ermC, vanA, vanB, tetK and tetM were screened. Results: Thirty isolates (12.3%) were positive for S. aureus by PCR with over 50% showing phenotypic resistance to methicillin. Resistance of S. aureus to antibiotics varied considerably with the highest resistance recorded to ampicillin and penicillin (96.7%), rifampicin and clindamycin (80%), oxacillin (73.3%) and erythromycin (70%). S.aureus revealed varying susceptibility to imipenem (96.7%), levofloxacin (86.7%), chloramphenicol (83.3%), cefoxitin (76.7%), ciprofloxacin (66.7%), gentamycin (63.3%), tetracycline and sulfamethoxazole-trimethoprim (56.7%), and vancomycin and doxycycline (50%). All 30 (100%) S. aureus isolates showed multiple antibiotic-resistant patterns (resistant to three or more antibiotics). The mecA, femA, rpoB, blaZ, ermB and tetM genes were detected in 5 (22.7%), 16 (53.3%), 11 (45.8%), 16 (55.2%), 15 (71.4%), and 8 (72.7%) isolates respectively; Conclusions: Results from this study indicate that beach water and sand from the Eastern Cape Province of South Africa may be potential

  8. Fluxes of nutrients and trace metals across the sediment-water interface controlled by sediment-capping agents: bentonite and sand.

    Science.gov (United States)

    Han, Junho; Ro, Hee-Myong; Cho, Kyung Hwa; Kim, Kyoung-Woong

    2016-10-01

    The effect of bentonite and sand, as natural capping agents, on the fluxes of nutrients and trace metals across the sediment-water interface was studied through sediment incubation, and the ecotoxicological impact was assessed by using Daphnia magna. Bentonite and sand were layered on the sediment at 15, 75, and 225 mg cm(-2), and the concentration of cations, nutrients, and trace metals was measured. Sediment incubation showed that bentonite reduced the N flux but increased the P flux as a result of dissolution of non-crystalline P from bentonite, while sand slightly decreased the N fluxes but not the P flux. The concentration of Na increased in the overlying water with increasing application rates of bentonite, while that of Ca decreased. However, regardless of the rate of sand application, concentrations of all cation species remained unchanged. The concentration of As and Cr increased with bentonite application rate but decreased with sand. Both capping materials suppressed fluxes of Cd, Cu, Ni, and Zn compared to control, and the extent of suppression was different depending on the trace metal species and capping agents used. During sediment incubation, the survival rate of D. magna significantly decreased in bentonite suspension but began to decrease at the end in sand suspension. Sediment capping of mildly polluted sediments by using bentonite and sand lowered the level of nutrients and trace metals. However, unexpected or undesirable side effects, such as influxes of P and As from bentonite to the overlying water and a possibility of toxic impacts to aquatic ecosystems, were observed, suggesting that capping agents with an adequate assessment of their side effects and toxicity should be predetermined for site-specific sediment management strategies.

  9. Reducing phosphorus loading of surface water using iron-coated sand

    NARCIS (Netherlands)

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

    2013-01-01

    Phosphorus losses from agricultural soils is an important source of P in surface waters leading to surface water quality impairment. In addition to reducing P inputs, mitigation measures are needed to reduce P enrichment of surface waters. Because drainage of agricultural land by pipe drainage is an

  10. Sand hazards on tourist beaches.

    Science.gov (United States)

    Heggie, Travis W

    2013-01-01

    Visiting the beach is a popular tourist activity worldwide. Unfortunately, the beach environment is abundant with hazards and potential danger to the unsuspecting tourist. While the traditional focus of beach safety has been water safety oriented, there is growing concern about the risks posed by the sand environment on beaches. This study reports on the death and near death experience of eight tourists in the collapse of sand holes, sand dunes, and sand tunnels. Each incident occurred suddenly and the complete burial in sand directly contributed to the victims injury or death in each case report.

  11. Feasibility of hydrofluoric acid etched sand particles for enrichment and determination of polychlorinated biphenyls at trace levels in environmental water samples.

    Science.gov (United States)

    Xing, Han-Zhu; Chen, Xiang-Feng; Wang, Xia; Wang, Ming-Lin; Zhao, Ru-Song

    2014-06-01

    This study aims to investigate the feasibility of etched sand particles being used as solid-phase extraction adsorbents to enrich polychlorinated biphenyls (PCBs), which are typical persistent organic pollutants in the environment, at trace levels. Gas chromatography-tandem mass spectrometry was selected to detect the compounds. Etched sand particles exhibited excellent merits on the enrichment of PCBs. Related important factors affecting extraction efficiencies were investigated and optimized in detail. Under optimized conditions, low limits of detection (0.42 to 3.69 ng L(-1)), wide linear range (10 to 1,000 ng L(-1)), and high repeatability (1.9 to 8.2%) were achieved. The developed method was validated with several real water samples, and satisfactory results were obtained. All of these findings indicate that etched sand particles would be useful for the enrichment and determination of organic pollutants at trace levels in water samples.

  12. Studies of dynamical processes affecting global climate

    Energy Technology Data Exchange (ETDEWEB)

    Keller, C.; Cooper, D.; Eichinger, W. [and others

    1998-12-31

    This is the final report of a three-year, Laboratory Directed Research and Development project at the Los Alamos National Laboratory (LANL). The main objective was, by a combined theoretical and observational approach, to develop improved models of dynamic processes in the oceans and atmosphere and to incorporate them into large climate codes, chiefly in four main areas: numerical physics, chemistry, water vapor, and ocean-atmosphere interactions. Main areas of investigation included studies of: cloud parameterizations for global climate codes, Lidar and the planetary boundary layer, chemistry, climate variability using coupled ocean-atmospheric models, and numerical physical methods. This project employed a unique approach that included participation of a number of University of California faculty, postdoctoral fellows and graduate students who collaborated with Los Alamos research staff on specific tasks, thus greatly enhancing the research output. Overall accomplishments during the sensing of the atmospheric planetary were: (1) first two- and three-dimensional remote sensing of the atmospheric planetary boundary layer using Lidars, (2) modeling of 20-year cycle in both pressure and sea surface temperatures in North Pacific, (3) modeling of low frequency internal variability, (4) addition of aerosols to stratosphere to simulate Pinatubo effect on ozone, (5) development of fast, comprehensive chemistry in the troposphere for urban pollution studies, (6) new prognostic cloud parameterization in global atmospheric code remedied problems with North Pacific atmospheric circulation and excessive equatorial precipitation, (7) development of a unique aerosol analysis technique, the aerosol time-of-flight mass spectrometer (ATOFMS), which allows real-time analysis of the size and chemical composition of individual aerosol particles, and (8) numerical physics applying Approximate Inertial Manifolds to ocean circulation. 14 refs., 6 figs.

  13. Thermodynamic and kinetic studies of As(V) removal from water by zirconium oxide-coated marine sand.

    Science.gov (United States)

    Khan, Tabrez Alam; Chaudhry, Saif Ali; Ali, Imran

    2013-08-01

    Arsenic contamination of groundwater is a major threat to human beings globally. Among various methods available for arsenic removal, adsorption is fast, inexpensive, selective, accurate, reproducible and eco-friendly in nature. The present paper describes removal of arsenate from water on zirconium oxide-coated sand (novel adsorbent). In the present work, zirconium oxide-coated sand was prepared and characterised by infrared and X-ray diffraction techniques. Batch experiments were performed to optimise different adsorption parameters such as initial arsenate concentration (100-1,000 μg/L), dose (1-8 g/L), pH of the solution (2-14), contact time (15-150 min.), and temperature (20, 30, 35 and 40 °C). The experimental data were analysed by Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models. Furthermore, thermodynamic and kinetic parameters were evaluated to know the mode of adsorption between ZrOCMS and As(V). The maximum removal of arsenic, 97 %, was achieved at initial arsenic concentration of 200 μg/L, after 75 min at dosage of 5.0 g/L, pH 7.0 and 27 ± 2 °C. For 600 μg/L concentration, the maximum Langmuir monolayer adsorption capacity was found to be 270 μg/g at 35 °C. Kinetic modelling data indicated that adsorption process followed pseudo-second-order kinetics. The mechanism is controlled by liquid film diffusion model. Thermodynamic parameter, ΔH°, was -57.782, while the values of ΔG° were -9.460, -12.183, -13.343 and -13.905 kJ/mol at 20, 30, 35 and 40 °C, respectively, suggesting exothermic and spontaneous nature of the process. The change in entropy, ΔS°= -0.23 kJ/mol indicated that the entropy decreased due to adsorption of arsenate ion onto the solid adsorbent. The results indicated that the reported zirconium oxide-coated marine sand (ZrOCMS) was good adsorbent with 97 % removal capacity at 200 μg/L concentration. It is interesting to note that the permissible limit of arsenic as per World Health Organization is 10

  14. Effect of Tube Length on Transport of Multi-Wall Nanotubes (MWNTs) in a Water-Saturated Quartz Sand

    Science.gov (United States)

    Wang, Y.; Baek, J.; Kim, J.; Pennell, K. D.

    2009-12-01

    With expanding commercial interests from various application areas, the production of carbon nanotubes (CNTs) in large scale is expected to grow rapidly. The inevitable release of CNTs into the environment and identification of the cytotoxicity of dispersed CNTs prompt the necessity of understanding their transport behavior in porous media. In this study, one-dimensional column experiments were conducted to assess the transport and retention of multi-wall nanotubes (MWNTs) in water-saturated 40-50 mesh Ottawa sand as a function of of tube length. In order to avoid damages to nanotube length by ultrasonication or superacids (e.g., HNO3), a chemical modification method involving a mild acid treatment was adopted to prepare suspensions of MWNTs with three different manufacture-reported (MR) lengths (0.5-2, 10-20, and 50 μm). For each experiment, a pulse (e.g., 5 pore volumes) of MWNT suspension was introduced into the column, followed by 3 pore volumes of MWNT-free solution elution. Measured concentrations of MWNTs in effluent and dissected solid samples were used to construct effluent breakthrough curves and retention profiles, respectively. For an input concentration of ca. 90 mg/L, MWNTs breakthrough concentrations decreased with the increasing MR length. Even with an MR length of 50 μm, MWNTs were readily transported through the packed bed, where ca. 80% of total injected nanotubes passed through the column. While the retention of MWNTs increased with MR length, concentrations of retained nanotubes decreased hyper-exponentially with distance from the column inlet. Further analysis of these findings suggests that clean-bed filtration theory alone is not sufficient to describe MWNT transport and retention behavior in a water-saturated quartz sand.

  15. Hydrogeologic characteristics and water quality of a confined sand unit in the surficial aquifer system, Hunter Army Airfield, Chatham County, Georgia

    Science.gov (United States)

    Gonthier, Gerard J.

    2012-01-01

    An 80-foot-deep well (36Q397, U.S. Geological Survey site identification 320146081073701) was constructed at Hunter Army Airfield to assess the potential of using the surficial aquifer system as a water source to irrigate a ballfield complex. A 300-foot-deep test hole was drilled beneath the ballfield complex to characterize the lithology and water-bearing characteristics of sediments above the Upper Floridan aquifer. The test hole was then completed as well 36Q397 open to a 19-foot-thick shallow, confined sand unit contained within the surficial aquifer system. A single-well, 24-hour aquifer test was performed by pumping well 36Q397 at a rate of 50 gallons per minute during July 13-14, 2011, to characterize the hydrologic properties of the shallow, confined sand unit. Two pumping events prior to the aquifer test affected water levels. Drawdown during all three pumping events and residual drawdown during recovery periods were simulated using the Theis formula on multiple changes in discharge rate. Simulated drawdown and residual drawdown match well with measured drawdown and residual drawdown using values of horizontal hydraulic conductivity and specific storage, which are typical for a confined sand aquifer. Based on the hydrologic parameters used to match simulated drawdown and residual drawdown to measured drawdown and residual drawdown, the transmissivity of the sand was determined to be about 400 feet squared per day. The horizontal hydraulic conductivity of the sand was determined to be about 20 feet per day. Analysis of a water-quality sample indicated that the water is suitable for irrigation. Sample analysis indicated a calcium-carbonate type water having a total dissolved solids concentration of 39 milligrams per liter. Specific conductance and concentrations of all analyzed constituents were below those that would be a concern for irrigation, and were below primary and secondary water-quality criteria levels.

  16. Adsorption and Removal of Organic Dye at Quartz Sand-Water Interface

    Directory of Open Access Journals (Sweden)

    Jada A.

    2013-11-01

    Full Text Available We studied the transport, sorption and desorption of organic cation (Methylene Blue, MB through a porous medium consisting of quartz sand particles negatively charged. We examined various parameters such as the ionic strength of the aqueous solution, the flow velocity, the pH of the aqueous phase, the temperature of the medium and the nature of the divalent metal cations present in solution, which affect the transport and the deposition of MB through the porous medium. Step-input experiments were carried out to measure the dye retention. The data showed a decrease in the MB adsorbed amount on the quartz, when the pH of the aqueous phase, or the temperature, decreases, or when the flow rate, or the affinity of the divalent cation (Ca2+, Cu2+, Zn2+ and Ba2+ toward the quartz surface increases. The increase in ionic strength leads to a small decrease in the MB adsorbed amount. However, the increase in temperature leads to an increase in the retained MB amount, which suggests that the adsorption of MB on the surface of quartz is endothermic in nature. The overall data indicate that, at ambient temperature, electrostatic interaction forces, which occur between the cationic organic pollutant and the negative surface of the quartz substrate, mainly control the adsorption process.

  17. Septic systems as sources of organic wastewater compounds in domestic drinking water wells in a shallow sand and gravel aquifer

    Energy Technology Data Exchange (ETDEWEB)

    Schaider, Laurel A., E-mail: schaider@silentspring.org; Ackerman, Janet M.; Rudel, Ruthann A.

    2016-03-15

    Domestic drinking water wells serve 44 million people in the US and are common globally. They are often located in areas served by onsite wastewater treatment systems, including septic systems, which can be sources of biological and chemical pollutants to groundwater. In this study we tested 20 domestic drinking water wells in a sand and gravel aquifer on Cape Cod, Massachusetts, USA, for 117 organic wastewater compounds (OWCs) and for inorganic markers of septic system impact. We detected 27 OWCs, including 12 pharmaceuticals, five per- and polyfluoroalkyl substances (PFASs), four organophosphate flame retardants, and an artificial sweetener (acesulfame). Maximum concentrations of several PFASs and pharmaceuticals were relatively high compared to public drinking water supplies in the US. The number of detected OWCs and total concentrations of pharmaceuticals and of PFASs were positively correlated with nitrate, boron, and acesulfame and negatively correlated with well depth. These wells were all located in areas served exclusively by onsite wastewater treatment systems, which are likely the main source of the OWCs in these wells, although landfill leachate may also be a source. Our results suggest that current regulations to protect domestic wells from pathogens in septic system discharges do not prevent OWCs from reaching domestic wells, and that nitrate, a commonly measured drinking water contaminant, is a useful screening tool for OWCs in domestic wells. Nitrate concentrations of 1 mg/L NO{sub 3}-N, which are tenfold higher than local background and tenfold lower than the US federal drinking water standard, were associated with wastewater impacts from OWCs in this study. - Highlights: • We tested 20 domestic drinking water wells for 117 organic wastewater compounds. • PFASs, pharmaceuticals, and an artificial sweetener were most frequently detected. • Nitrate, boron, and well depth were all correlated with PFASs and pharmaceuticals. • Acesulfame

  18. Effect of silty sand in formation water on CO{sub 2} corrosion behavior of carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wei, E-mail: weiliu@ustb.edu.cn; Dou, Juanjuan; Lu, Songle; Zhang, Peng; Zhao, Qinghe

    2016-03-30

    Graphical abstract: Silty sand (SiO{sub 2}) promoted the rapid heterogeneous nucleation of corrosion product (FeCO{sub 3}) and simultaneously decreased its grains growth. Silty sand mixed with corrosion product to form the outer layer of corrosion scale with high compactness, blocking the transport of ferrous ions and leading to the formation of the inner layer of corrosion scale without silty sand. The corrosion rate of carbon steel was obviously reduced due to the existence of silty sand in the outer layer by inhibiting anodic and cathodic currents. - Highlights: • CO{sub 2} corrosion rate of carbon steel was obviously reduced due to the existence of silty sand. • The corrosion scale containing silty sand inhibited anodic and cathodic currents, contributing to low corrosion rate. • A development mechanism of corrosion scale in silty sand containing CO{sub 2} environment was proposed. - Abstract: Corrosion behavior of carbon steel in CO{sub 2} aqueous environment containing silty sand was investigated using corrosion mass loss method, scanning electron microscopy (SEM), energy diffraction spectrum (EDS), and various electrochemical measurements. The results show that the corrosion rate of carbon steel was obviously reduced due to the existence of silty sand. Silty sand promoted the rapid heterogeneous nucleation of corrosion product FeCO{sub 3} and simultaneously decreased its grains growth. Silty sand mixed with corrosion product to form the outer layer of corrosion scale with high compactness, blocking the transport of ferrous ions and leading to the formation of the inner layer of corrosion scale without silty sand. The existence of silty sand in the outer layer of corrosion scale inhibited anodic and cathodic currents.

  19. Survival of Organic Materials in Hypervelocity Impacts of Ice on Sand, Ice, and Water in the Laboratory

    Science.gov (United States)

    Bowden, Stephen A.; Cole, Michael; Parnell, John

    2014-01-01

    Abstract The survival of organic molecules in shock impact events has been investigated in the laboratory. A frozen mixture of anthracene and stearic acid, solvated in dimethylsulfoxide (DMSO), was fired in a two-stage light gas gun at speeds of ∼2 and ∼4 km s−1 at targets that included water ice, water, and sand. This involved shock pressures in the range of 2–12 GPa. It was found that the projectile materials were present in elevated quantities in the targets after impact and in some cases in the crater ejecta as well. For DMSO impacting water at 1.9 km s−1 and 45° incidence, we quantify the surviving fraction after impact as 0.44±0.05. This demonstrates successful transfer of organic compounds from projectile to target in high-speed impacts. The range of impact speeds used covers that involved in impacts of terrestrial meteorites on the Moon, as well as impacts in the outer Solar System on icy bodies such as Pluto. The results provide laboratory evidence that suggests that exogenous delivery of complex organic molecules from icy impactors is a viable source of such material on target bodies. Key Words: Organic—Hypervelocity—Shock—Biomarkers. Astrobiology 14, 473–485. PMID:24901745

  20. A sand wave simulation model

    NARCIS (Netherlands)

    Nemeth, A.A.; Hulscher, S.J.M.H.; Damme, van R.M.J.

    2003-01-01

    Sand waves form a prominent regular pattern in the offshore seabeds of sandy shallow seas. A two dimensional vertical (2DV) flow and morphological numerical model describing the behaviour of these sand waves has been developed. The model contains the 2DV shallow water equations, with a free water su

  1. Hysteresis in the nonmonotonic electric response of homogeneous and layered unconsolidated sands under continuous flow conditions with water of various salinities, 100 kHz to 2 MHz

    NARCIS (Netherlands)

    Kavian, M.; Slob, E.C.; Mulder, W.A.

    2011-01-01

    We measured the electric parameters for four different configurations of unconsolidated homogeneous and layered sands as a function of frequency, water saturation, and salinity under fluid flow conditions. Our objective is to determine if the effect of heterogeneities at scales much smaller than the

  2. Effect of probiotic and sand filtration treatments on water quality and growth of tilapia (Oreochromis niloticus) and pangas (Pangasianodon hypophthalmus) in earthen ponds of southern Bangladesh

    DEFF Research Database (Denmark)

    Mahmud, Sultan; Ali, Mohammad Lokman; Alam, Md Ariful

    2016-01-01

    Effects of water treatment by two probiotic products (PondPlus® and AquaPhoto®) and sand filtration were studied on growth performance of tilapia (Oreochromis niloticus) and pangas (Pangasianodon hypophthalmus) stocked at tilapia:pangas ratio of 5:3 in traditional earthen ponds in Bangladesh...

  3. Pore water chemistry in the beach sands of central Tamil Nadu, India

    Digital Repository Service at National Institute of Oceanography (India)

    Chandrasekar, N.; Gujar, A.R.; Loveson, V.J.; Rajamanickam, G.V.; Moscow, S.; Manickaraj, D.S.; Chandrasekaran, R.; Chaturvedi, S.K.; Mahesh, R.; Sudha, V.; Josephine, P.J.; Deepa, V.

    As the pore water chemistry- has been considered as one of the prominent base parameters to infer the impact of coastal mining in introducing environmental deterioration, a study in pore water chemistry is planned here along the beaches for a length...

  4. Septic systems as sources of organic wastewater compounds in domestic drinking water wells in a shallow sand and gravel aquifer.

    Science.gov (United States)

    Schaider, Laurel A; Ackerman, Janet M; Rudel, Ruthann A

    2016-03-15

    Domestic drinking water wells serve 44 million people in the US and are common globally. They are often located in areas served by onsite wastewater treatment systems, including septic systems, which can be sources of biological and chemical pollutants to groundwater. In this study we tested 20 domestic drinking water wells in a sand and gravel aquifer on Cape Cod, Massachusetts, USA, for 117 organic wastewater compounds (OWCs) and for inorganic markers of septic system impact. We detected 27 OWCs, including 12 pharmaceuticals, five per- and polyfluoroalkyl substances (PFASs), four organophosphate flame retardants, and an artificial sweetener (acesulfame). Maximum concentrations of several PFASs and pharmaceuticals were relatively high compared to public drinking water supplies in the US. The number of detected OWCs and total concentrations of pharmaceuticals and of PFASs were positively correlated with nitrate, boron, and acesulfame and negatively correlated with well depth. These wells were all located in areas served exclusively by onsite wastewater treatment systems, which are likely the main source of the OWCs in these wells, although landfill leachate may also be a source. Our results suggest that current regulations to protect domestic wells from pathogens in septic system discharges do not prevent OWCs from reaching domestic wells, and that nitrate, a commonly measured drinking water contaminant, is a useful screening tool for OWCs in domestic wells. Nitrate concentrations of 1mg/L NO3-N, which are tenfold higher than local background and tenfold lower than the US federal drinking water standard, were associated with wastewater impacts from OWCs in this study.

  5. Comparison of the water change characteristics between the formation and dissociation of methane hydrate and the freezing and thawing of ice in sand

    Institute of Scientific and Technical Information of China (English)

    Peng Zhang; Qingbai Wu; Yingmei Wang

    2009-01-01

    Hydrate formation and dissociation processes are always accompanied by water migration in porous media, which is similar to the ice. In our study, a novel pF-meter sensor which could detect the changes of water content inside sand was first applied to hydrate formation and dissociation processes. It also can study the water change characteristics in the core scale of a partially saturated silica sand sample and compare the differences of water changes between the processes of formation and dissociation of methane hydrate and freezing and thawing of ice. The experimental results showed that the water changes in the processes of formation and dissociation of methane hydrate were basically similar to that of the freezing and thawing of ice in sand. When methane hydrate or ice was formed, water changes showed the decrease in water content on the whole and the pF values rose following the formation processes. However, there were very obvious differences between the ice thawing and hydrate dissociation.

  6. Phosphate limitation in biological rapid sand filters used to remove ammonium from drinking water

    DEFF Research Database (Denmark)

    Lee, Carson Odell; Albrechtsen, Hans-Jørgen; Smets, Barth F.

    2013-01-01

    Removing ammonium from drinking water is important for maintaining biological stability in distribution systems. This is especially important in regions that do not use disinfectants in the treatment process or keep a disinfectant residual in the distribution system. Problems with nitrification can...... the total number of ammonium oxidizing bacteria in the column. © 2013 American Water Works Association AWWA WQTC Conference Proceedings All Rights Reserved....

  7. Water, Energy and Carbon Balance Research: Recovery Trajectories For Oil Sands Reclamation and Disturbed Watersheds in the Western Boreal Forest

    Science.gov (United States)

    Petrone, R. M.; Carey, S. K.

    2014-12-01

    The Oil Sand Region (OSR) of North-Central Alberta exists within the sub-humid Boreal Plains (BP) ecozone, with a slight long-term moisture deficit regime. Despite this deficit, the BP is comprised of productive wetland and mixed wood (aspen and conifer dominated) forests. Reclamation activities are now underway at a large number of surface mining operations in the OSR, where target ecosystems are identified, soil prescriptions placed and commercial forest species planted. Some watersheds have been created that now contain wetlands. However, recent work in the BP suggests that over time wetlands supply moisture for the productivity of upland forests. Thus, water use of reclaimed forests is going to be critical in determining the sustainability of these systems and adjacent wetlands, and whether in time, either will achieve some form of equivalent capability that will allow for certification by regulators. A critical component in the success of any reclamation is that sufficient water is available to support target ecosystems through the course of natural climate cycles in the region. Water Use Efficiency (WUE), which links photosynthesis (GEP) with water use (Evapotranspiration (ET)), provides a useful metric to compare ecosystems and evaluate their utilization of resources. In this study, 41 site years of total growing season water and carbon flux data over 8 sites (4 reclamation, 4 regeneration) were evaluated using eddy covariance micrometeorological towers. WUE shows clear discrimination among ecosystem types as aspen stands assimilate more carbon per unit weight of water than conifers. WUEs also change with time as ecosystems become more effective at transpiring water through plant pathways compared with bare-soil evaporation, which allows an assessment of ability to limit water loss without carbon uptake. In addition, clonal rooting systems allow aspen forests to recover quicker after disturbance than reclamation sites in terms of their WUE. For reclamation

  8. Modeling of CO{sub 2}-hydrate formation at the gas-water interface in sand sediment

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, T.; Sato, T.; Hirabayashi, S.; Brumby, P.E. [University of Tokyo, Department of Ocean Technology, Policy, and Environment, Kashiwa (Japan); Inui, M. [Mitsubishi Heavy Industries America, Inc., Environmental Systems Division, Austin, TX (United States)

    2012-10-15

    Sub-seabed geological storage of CO{sub 2} in the form of gas hydrate is attractive because clathrate hydrate stably exists at low temperature and high pressure, even if a fault occurs by diastrophism like a big earthquake. For the effective design of the storage system it is necessary to model the formation of CO{sub 2}-hydrate. Here, it is assumed that the formation of gas hydrate on the interface between gas and water consists of two stages: gas diffusion through the CO{sub 2}-hydrate film and consequent CO{sub 2}-hydrate formation on the interface, between film and water. Also proposed is the presence of a fresh reaction interface, which is part of the interface between the gas and aqueous phases and not covered with CO{sub 2}-hydrate. Parameters necessary to model the hydrate formation in sand sediment are derived by comparing the results of the present numerical simulations and the measurements in the literature. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. Protocol for Measuring the Thermal Properties of a Supercooled Synthetic Sand-water-gas-methane Hydrate Sample.

    Science.gov (United States)

    Muraoka, Michihiro; Susuki, Naoko; Yamaguchi, Hiroko; Tsuji, Tomoya; Yamamoto, Yoshitaka

    2016-03-21

    Methane hydrates (MHs) are present in large amounts in the ocean floor and permafrost regions. Methane and hydrogen hydrates are being studied as future energy resources and energy storage media. To develop a method for gas production from natural MH-bearing sediments and hydrate-based technologies, it is imperative to understand the thermal properties of gas hydrates. The thermal properties' measurements of samples comprising sand, water, methane, and MH are difficult because the melting heat of MH may affect the measurements. To solve this problem, we performed thermal properties' measurements at supercooled conditions during MH formation. The measurement protocol, calculation method of the saturation change, and tips for thermal constants' analysis of the sample using transient plane source techniques are described here. The effect of the formation heat of MH on measurement is very small because the gas hydrate formation rate is very slow. This measurement method can be applied to the thermal properties of the gas hydrate-water-guest gas system, which contains hydrogen, CO2, and ozone hydrates, because the characteristic low formation rate of gas hydrate is not unique to MH. The key point of this method is the low rate of phase transition of the target material. Hence, this method may be applied to other materials having low phase-transition rates.

  10. Ammonium removal pathways and microbial community in GAC-sand dual media filter in drinking water treatment

    Institute of Scientific and Technical Information of China (English)

    Shuo Feng; Shuguang Xie; Xiaojian Zhang; Zhiyu Yang; Wei Ding; Xiaobin Liao; Yuanyuan Liu; Chao Chen

    2012-01-01

    A GAC-sand dual media filter (GSF) was devised as an alternative solution for drinking water treatment plant to tackle the.raw water polluted by ammonium in place of expensive ozone-GAC processes or bio-pretreatments.The ammonium removal pathways and microbial community in the GSFs were investigated.The concentrations of ammonium,nitrite and nitrate nitrogen were monitored along the filter.Total inorganic nitrogen (TIN) loss occurred during the filtration.For 1 mg ammonium removal,the TIN loss was as high as 0.35 mg,DO consumption was 3.06 mg,and alkalinity consumption was 5.55 mg.It was assumed that both nitrification and denitrification processes occur in the filters to fit the TIN loss and low DO consumption.During the filtration,nitritation,nitrification and nitritation-anaerobic ammonium oxidation processes probably occur,while traditional nitrification and denitrification and simultaneous nitrification and denitrification processes may occur.In the GSFs,Nitrosomonas and Nitrospira are likely to be involved in nitrification processes,while Novosphingobium,Comamonadaceae and Oxalobacteraceae may be involved in denitrification processes.

  11. Simulated water-level and water-quality changes in the bolson-fill aquifer, Post Headquarters area, White Sands Missile Range, New Mexico

    Science.gov (United States)

    Risser, D.W.

    1988-01-01

    The quantity of freshwater available in the Post Headquarters well field, White Sand Missile Range, New Mexico, is limited and its quality is threatened by saltwater enroachment. A three-dimensional, finite-difference, groundwater flow model and a cross-sectional, density-dependent solute-transport model were constructed to simulate possible future water level declines and water quality changes in the Post Headquarters well field. A six-layer flow model was constructed using hydraulic-conductivity values in the upper 600 ft of saturated aquifer ranging from 0.1 to 10 ft/day, specific yield of 0.15, and average recharge of about 1,590 acre-ft/yr. Water levels simulated by the model closely matched measured water levels for 1948-82. Possible future water level changes for 1983-2017 were simulated using rates of groundwater withdrawal of 1,033 and 2 ,066 acre-ft/year and wastewater return flow of 0 or 30% of the groundwater withdrawal rate. The cross-sectional solute-transport model indicated that the freshwater zone is about 1,500 to 2,000 ft thick beneath the well field. Transient simulations show that solutes probably will move laterally toward the well field rather than from beneath the well field. (USGS)

  12. Effects of surfactant treatments on the wettability of a water repellent grass-covered dune sand

    NARCIS (Netherlands)

    Dekker, L.W.; Oostindie, K.; Kostka, S.J.; Ritsema, C.J.

    2005-01-01

    Copper is an important micronutrient and trace amounts are essential for crop growth. However, high concentrations of copper will produce toxic effects. Australia is increasingly developing production of crops in water repellent soils. Clay amendment, a common amelioration techniques used in Austral

  13. Comparison of a sand and membrane filtration unit for drinking water production –focus on the arsenic removal

    DEFF Research Database (Denmark)

    Kowalski, Krysztof; Søgaard, Erik Gydesen

    2013-01-01

    Arsenic removal from groundwater by help of micro- (pore size of 1 µm) and ultrafiltration (pore size of 0,04 µm) was evaluated and compared with sand filtration. The dead-end filtration enabled to compare MF/UF with conventional sand filter. The results indicate that none of membrane processes w...

  14. Effect of Low Energy Waves on the Accumulation and Transport of Fecal Indicator Bacteria in Sand and Pore Water at Freshwater Beaches.

    Science.gov (United States)

    Wu, Ming Zhi; O'Carroll, Denis M; Vogel, Laura J; Robinson, Clare E

    2017-02-24

    Elevated fecal indicator bacteria (FIB) in beach sand and pore water represent an important nonpoint source of contamination to surface waters. This study examines the physical processes governing the accumulation and distribution of FIB in a beach aquifer. Field data indicate E. coli and enterococci can be transported 1 and 2 m, respectively, below the water table. Data were used to calibrate a numerical model whereby FIB are delivered to a beach aquifer by wave-induced infiltration across the beach face. Simulations indicate FIB rapidly accumulate in a beach aquifer with FIB primarily associated with sand rather than freely residing in the pore water. Simulated transport of E. coli in a beach aquifer is complex and does not correlate with conservative tracer transport. Beaches with higher wave-induced infiltration rate and vertical infiltration velocity (i.e., beaches with higher beach slope and wave height, and lower terrestrial groundwater discharge) had greater E. coli accumulation and E. coli was transported deeper below the beach face. For certain beach conditions, the amount of FIB accumulated in sand over 5-6 days was found to be sufficient to trigger a beach advisory if eroded to surface water.

  15. The kinetics of activation and deactivation in the process of water ozonising used for advanced oxidation of the dust waste from moulding sands

    Directory of Open Access Journals (Sweden)

    A. Baliński

    2009-01-01

    Full Text Available Adding coal dust and organic carriers of the lustrous carbon to bentonite-bonded moulding sands in amounts justified by thetechnological regime and the use of cores and protective coatings based on organic compounds create serious threats to the environment.During thermal destruction of the individual components of moulding and core sands, some toxic organic compounds are emitted. They formthe majority of the Hazardous Air Pollutants (HAPs, and include mainly compounds like benzene, toluene, xylene, naphtalene, hexane,acetaldehyde, acrolein, aniline, cresol and cumene, their polycyclic derivatives, phenol, formaldehyde, and other similar matters. In thusformed dust waste, the amount of which constitutes about 20% of all the waste from foundries using traditional moulding and core sands, there are still full-value materials which can undergo total recycling, providing the HAPs are partially or totally removed from them. The article discusses some problems of the advanced oxidation of selected toxic chemical compounds present in bentonite-bonded moulding sands due to the effect of high temperature. The results of the investigations of the kinetics of the process of maximum water saturation with ozone (acting as an oxidiser and of the kinetics of the natural process of ozone decomposition to diatomic oxygen were presented. It has been stated that the maximum time of water saturation with ozone using an OZOMATIC OSC-MODULAR 4HC ozone generator and a 1m3 capacity tank with water is 60 minutes. After 30 minute break in the ozonising process, the ozone concentration in water decreases by 40 to 50%. To obtain maximum ozone concentration in water during the next ozonising cycle, it is necessary to have the ozone-generating device running for the next 30 minutes. The stabilisation of ozone concentration in water takes place only after the third ozonising cycle, when it reaches nearly 80%of the maximum value obtained after the first process cycle

  16. Sediment mathematical model for sand ridges and sand waves

    Institute of Scientific and Technical Information of China (English)

    LI Daming; WANG Xiao; WANG Xin; LI Yangyang

    2016-01-01

    A new theoretical model is formulated to describe internal movement mechanisms of the sand ridges and sand waves based on the momentum equation of a solid-liquid two-phase flow under a shear flow. Coupling this equation with two-dimensional shallow water equations and wave reflection-diffraction equation of mild slope, a two-dimensional coupling model is established and a validation is carried out by observed hydrogeology, tides, waves and sediment. The numerical results are compared with available observations. Satisfactory agreements are achieved. This coupling model is then applied to the Dongfang 1-1 Gas Field area to quantitatively predict the movement and evolution of submarine sand ridges and sand waves. As a result, it is found that the sand ridges and sand waves movement distance increases year by year, but the development trend is stable.

  17. Microbial oxidation of soluble sulfide in produced water from the Bakkeen Sands

    Energy Technology Data Exchange (ETDEWEB)

    Gevertz, D.; Zimmerman, S. [Agouron Institute, La Jolla, CA (United States); Jenneman, G.E. [Phillips Petroleum Company, Bartlesville, OK (United States)] [and others

    1995-12-31

    The presence of soluble sulfide in produced water results in problems for the petroleum industry due to its toxicity, odor, corrosive nature, and potential for wellbore plugging. Sulfide oxidation by indigenous nitrate-reducing bacteria (NRB) present in brine collected from wells at the Coleville Unit (CVU) in Saskatchewan, Canada, was investigated. Sulfide oxidation took place readily when nitrate and phosphate were added to brine enrichment cultures, resulting in a decrease in sulfide levels of 99-165 ppm to nondetectable levels (< 3.3 ppm). Produced water collected from a number of producing wells was screened to determine the time required for complete sulfide oxidation, in order to select candidate wells for treatment. Three wells were chosen, based on sulfide removal in 48 hours or less. These wells were treated down the backside of the annulus with a solution containing 10 mM KNO{sub 3} and 100 {mu}M NaH{sub 2}PO{sub 4}. Following a 24- to 72-hour shut-in, reductions in pretreatment sulfide levels of greater than 90% were observed for two of the wells, as well as sustained sulfide reductions of 50% for at least two days following startup. NRB populations in the produced brine were observed to increase significantly following treatment, but no significant increases in sulfate-reducing bacteria were observed. These results demonstrate the technical feasibility of stimulating indigenous populations of NRB to remediate and control sulfide in produced brine.

  18. Conversion of sand filters into activated carbon filters at the La Presa (Valencia) water works; Conversion de filtros de arena porcarbon activo en la ETAP de La Presa (Valencia)

    Energy Technology Data Exchange (ETDEWEB)

    Macian Cervera, V. J.; Monforte Monleon, L.; Ribera Orts, R.; Suris Jorda, J. I.; Klee, J. M.

    2007-07-01

    To improve the water quality at potable water treatment plant of La P esa (Valencia), the sand filters have been replaced for activated carbon filters. In the following review the results and conclusions of the direct sand filter conversion into activated carbon filters will be presented. The leads to a simple and fast solution to odour and taste removal, as well as dissolved organic matter, without investments in works at the water works. (Author)

  19. Comparison of grey water treatment performance by a cascading sand filter and a constructed wetland.

    Science.gov (United States)

    Kadewa, W W; Le Corre, K; Pidou, M; Jeffrey, P J; Jefferson, B

    2010-01-01

    A novel unplanted vertical flow subsurface constructed wetland technology comprising three shallow beds (0.6 m length, 0.45 m width and 0.2 m depth) arranged in a cascading series and a standard single-pass Vertical Flow Planted Constructed Wetland (VFPCW, 6 m² and 0.7 m depth) were tested for grey water treatment. Particular focus was on meeting consent for published wastewater reuse parameters and removal of anionic surfactants. Treatment performance at two hydraulic loading rates (HLR) of 0.08, and 0.17 m³ m⁻² d⁻¹ were compared. Both technologies effectively removed more than 90% turbidity and more than 96% for organics with the prototype meeting the most stringent reuse standard of < 2 NTU and <10 mg/L. However, surfactant removal in the VFPCW was higher (76-85%) than in the prototype which only achieved more than 50% removal at higher loading rate. Generally, the prototype performed consistently better than the VFPCW except for surfactant removal. However, at higher loading rates, both systems did not meet the reuse standard of <1 mg L⁻¹ for anionic surfactants. This observation confirms that shallow beds provide a more oxidised environment leading to higher BOD₅ and COD removals. Presence of plants in the VFPCW led to higher anionic surfactant removal, through increased microbial and sorption processes.

  20. Molecular characterization of microbial populations in groundwater sources and sand filters for drinking water production.

    Science.gov (United States)

    de Vet, W W J M; Dinkla, I J T; Muyzer, G; Rietveld, L C; van Loosdrecht, M C M

    2009-01-01

    In full-scale drinking water production from groundwater, subsurface aeration is an effective means of enhancing the often troublesome process of nitrification. Until now the exact mechanism, however, has been unknown. By studying the microbial population we can improve the understanding of this process. Denaturing gradient gel electrophoresis of PCR-amplified 16S rRNA gene fragments of bacteria, archaea and ammonia-oxidizing bacteria was used to characterize the microbial populations in raw groundwater and trickling filters of an active nitrifying surface aerated system and an inactive non-surface aerated system. Only in the active filter were nitrifying microorganisms found above the detection limit of the method. In ammonia oxidation in this groundwater filter both bacteria and archaea played a role, while members belonging to the genus Nitrospira were the only nitrite-oxidizing species found. The subsurface aerated groundwater did not contain any of the nitrifying organisms active in the filter above the detection limit, but did contain Gallionella species that might play a major role in iron oxidation in the filter.

  1. The effect of a natural water-movement related disturbance on the structure of meiofauna and macrofauna communities in the intertidal sand flat of Rocas Atoll (NE, Brazil)

    Science.gov (United States)

    Netto, S. A.; Attrill, M. J.; Warwick, R. M.

    1999-12-01

    Rocas, the only atoll in the South Atlantic, is located 266 km off the northeast Brazilian coast. Spatial patterns in community structure of meiofauna, particularly nematodes, and macrofauna were examined along a transect through the sediment path from windward to leeward of the Rocas Atoll sand flat. Differences in benthic community structure between four zones of the sand flat were found to be significant and related to the major local processes of carbonate-grain transport and sedimentation. Both meiobenthic and macrobenthic assemblages were significantly more diverse and abundant within the sediment inflow zone (the initial part of the detrital path of Rocas sand flat) than in the other zones, where a clear impoverishment of benthic invertebrates occurred. This first study of the benthos of an intertidal sand flat over a reef island in the Atlantic showed that the meiofauna is numerically dominated by the nematodes Metoncholainus sp. 1 (Oncholaimidae) and Epsilonema sp. 1 (Epsilonematidade), whilst the macrofauna is largely dominated by oligochaetes and large Oncholaimidae nematodes. Analysis of the species composition, trophic structure and abundance of both the meiobenthos and the macrobenthos revealed an impoverished community subjected to an intense water-movement disturbance.

  2. 2010 oil sands performance report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    With the depletion of traditional energy resources and the rising demand for energy, oil sands have become an important energy resource for meeting energy needs. Oil sands are a mixture of water, sand, clay and bitumen which is recovered either through open pit mining or in situ drilling techniques. The bitumen is then converted into syncrude or sold to refineries for the production of gasoline, diesel or other products. Shell has oil sands operations in Alberta and the aim of this report is to present its 2010 performance in terms of CO2, water, tailings, land, and reclamation and engagement. This document covers several of Shell's operations in the Muskeg River and Jackpine mines, Scotford upgrader, Peace River, Orion, Seal, Cliffdale and Chipmunk. It provides useful information on Shell's oil sands performance to governments, environmental groups, First Nations, local communities and the public.

  3. Evaluation of the Impact of the Plastic BioSand Filter on Health and Drinking Water Quality in Rural Tamale, Ghana

    Directory of Open Access Journals (Sweden)

    Mumuni K. Osman

    2012-10-01

    Full Text Available A randomized controlled trial of the plastic BioSand filter (BSF was performed in rural communities in Tamale (Ghana to assess reductions in diarrheal disease and improvements in household drinking water quality. Few studies of household water filters have been performed in this region, where high drinking water turbidity can be a challenge for other household water treatment technologies. During the study, the longitudinal prevalence ratio for diarrhea comparing households that received the plastic BSF to households that did not receive it was 0.40 (95% confidence interval: 0.05, 0.80, suggesting an overall diarrheal disease reduction of 60%. The plastic BSF achieved a geometric mean reduction of 97% and 67% for E. coli and turbidity, respectively. These results suggest the plastic BSF significantly improved drinking water quality and reduced diarrheal disease during the short trial in rural Tamale, Ghana. The results are similar to other trials of household drinking water treatment technologies.

  4. Evaluation of the impact of the plastic BioSand filter on health and drinking water quality in rural Tamale, Ghana.

    Science.gov (United States)

    Stauber, Christine E; Kominek, Byron; Liang, Kaida R; Osman, Mumuni K; Sobsey, Mark D

    2012-10-24

    A randomized controlled trial of the plastic BioSand filter (BSF) was performed in rural communities in Tamale (Ghana) to assess reductions in diarrheal disease and improvements in household drinking water quality. Few studies of household water filters have been performed in this region, where high drinking water turbidity can be a challenge for other household water treatment technologies. During the study, the longitudinal prevalence ratio for diarrhea comparing households that received the plastic BSF to households that did not receive it was 0.41 (95% confidence interval: 0.18, 0.92), suggesting an overall diarrheal disease reduction of 59% [corrected]. The plastic BSF achieved a geometric mean reduction of 97% and 67% for E. coli and turbidity, respectively. These results suggest the plastic BSF significantly improved drinking water quality and reduced diarrheal disease during the short trial in rural Tamale, Ghana. The results are similar to other trials of household drinking water treatment technologies.

  5. Bituminous sands : tax issues

    Energy Technology Data Exchange (ETDEWEB)

    Patel, B. [PricewaterhouseCoopers LLP, Calgary, AB (Canada)

    2004-07-01

    This paper examined some of the tax issues associated with the production of bitumen or synthetic crude oil from oil sands. The oil sands deposits in Alberta are gaining more attention as the supplies of conventional oil in Canada decline. The oil sands reserves located in the Athabasca, Cold Lake and Peace River areas contain about 2.5 trillion barrels of highly viscous hydrocarbons called bitumen, of which nearly 315 billion barrels are recoverable with current technology. The extraction method varies for each geographic area, and even within zones and reservoirs. The two most common extraction methods are surface mining and in-situ extraction such as cyclic steam stimulation (CSS); low pressure steam flood; pressure cycle steam drive; steam assisted gravity drainage (SAGD); hot water flooding; and, fire flood. This paper also discussed the following general tax issues: bituminous sands definition; bituminous sands leases and Canadian development expense versus Canadian oil and gas property expense (COGPE); Canadian exploration expense (CEE) for surface mining versus in-situ methods; additional capital cost allowance; and, scientific research and experimental development (SR and ED). 15 refs.

  6. Ecotoxicological impacts of effluents generated by oil sands bitumen extraction and oil sands lixiviation on Pseudokirchneriella subcapitata.

    Science.gov (United States)

    Debenest, T; Turcotte, P; Gagné, F; Gagnon, C; Blaise, C

    2012-05-15

    The exploitation of Athabasca oil sands deposits in northern Alberta has known an intense development in recent years. This development has raised concern about the ecotoxicological risk of such industrial activities adjacent to the Athabasca River. Indeed, bitumen extraction generated large amounts of oil sands process-affected water (OSPW) which are discharged in tailing ponds in the Athabasca River watershed. This study sought to evaluate and compare the toxicity of OSPW and oil sands lixiviate water (OSLW) with a baseline (oil sands exposed to water; OSW) on a microalgae, Pseudokirchneriella subcapitata, at different concentrations (1.9, 5.5, 12.25, 25 and 37.5%, v/v). Chemical analyses of water-soluble contaminants showed that OSPW and OSLW were enriched in different elements such as vanadium (enrichment factor, EF=66 and 12, respectively), aluminum (EF=64 and 15, respectively), iron (EF=52.5 and 17.1, respectively) and chromium (39 and 10, respectively). The toxicity of OSPW on cells with optimal intracellular esterase activity and chlorophyll autofluorescence (viable cells) (72h-IC 50%37.5%, v/v). OSLW was 4.4 times less toxic (IC 50%=8.5%, v/v) than OSPW and 4.5 times more toxic than OSW. The inhibition of viable cell growth was significantly and highly correlated (copper, lead, molybdenum and vanadium concentrations. The specific photosynthetic responses studied with JIP-test (rapid and polyphasic chlorophyll a fluorescence emission) showed a stimulation of the different functional parameters (efficiency of PSII to absorb energy from photons, size of effective PSII antenna and vitality of photosynthetic apparatus for energy conversion) in cultures exposed to OSPW and OSLW. To our knowledge, our study highlights the first evidence of physiological effects of OSPW and OSLW on microalgae. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

  7. Ecotoxicological impacts of effluents generated by oil sands bitumen extraction and oil sands lixiviation on Pseudokirchneriella subcapitata

    Energy Technology Data Exchange (ETDEWEB)

    Debenest, T., E-mail: tdebenest@yahoo.fr [Environment Canada, Fluvial Ecosystem Research, 105 McGill Street, 7 floor, Montreal, Quebec, H2Y 2E7 (Canada); Turcotte, P. [Environment Canada, Fluvial Ecosystem Research, 105 McGill Street, 7 floor, Montreal, Quebec, H2Y 2E7 (Canada); Gagne, F., E-mail: francois.gagne@ec.gc.ca [Environment Canada, Fluvial Ecosystem Research, 105 McGill Street, 7 floor, Montreal, Quebec, H2Y 2E7 (Canada); Gagnon, C.; Blaise, C. [Environment Canada, Fluvial Ecosystem Research, 105 McGill Street, 7 floor, Montreal, Quebec, H2Y 2E7 (Canada)

    2012-05-15

    The exploitation of Athabasca oil sands deposits in northern Alberta has known an intense development in recent years. This development has raised concern about the ecotoxicological risk of such industrial activities adjacent to the Athabasca River. Indeed, bitumen extraction generated large amounts of oil sands process-affected water (OSPW) which are discharged in tailing ponds in the Athabasca River watershed. This study sought to evaluate and compare the toxicity of OSPW and oil sands lixiviate water (OSLW) with a baseline (oil sands exposed to water; OSW) on a microalgae, Pseudokirchneriella subcapitata, at different concentrations (1.9, 5.5, 12.25, 25 and 37.5%, v/v). Chemical analyses of water-soluble contaminants showed that OSPW and OSLW were enriched in different elements such as vanadium (enrichment factor, EF = 66 and 12, respectively), aluminum (EF = 64 and 15, respectively), iron (EF = 52.5 and 17.1, respectively) and chromium (39 and 10, respectively). The toxicity of OSPW on cells with optimal intracellular esterase activity and chlorophyll autofluorescence (viable cells) (72 h-IC 50% < 1.9%) was 20 times higher than the one of OSW (72 h-IC 50% > 37.5%, v/v). OSLW was 4.4 times less toxic (IC 50% = 8.5%, v/v) than OSPW and 4.5 times more toxic than OSW. The inhibition of viable cell growth was significantly and highly correlated (<-0.7) with the increase of arsenic, beryllium, chromium, copper, lead, molybdenum and vanadium concentrations. The specific photosynthetic responses studied with JIP-test (rapid and polyphasic chlorophyll a fluorescence emission) showed a stimulation of the different functional parameters (efficiency of PSII to absorb energy from photons, size of effective PSII antenna and vitality of photosynthetic apparatus for energy conversion) in cultures exposed to OSPW and OSLW. To our knowledge, our study highlights the first evidence of physiological effects of OSPW and OSLW on microalgae.

  8. 彰武沙地水利改良与利用研究%Improved Water Conservation of Sand Land and its Utilization in Zhangwu County

    Institute of Scientific and Technical Information of China (English)

    焦树仁; 李春龙; 王宝泽; 佟威

    2015-01-01

    In order to improve water conservation and utilization of sand,the experimental demonstration zone in Aer Township of Zhangwu County in Liaoning Province was established.Result shows that:bulldozing dunes can improve the water condition of sand,increase the soil moisture content by 0.9%-1.3%,and expand the utilization area for sand land by 25%-30%;wells were made by using groundwater;a well is distributed every 3.3 hm2;the a-mount of water is seven tons per hour,which used for irrigating farmland,medicine garden,nursery and fast-grow-ing forest.Implementing micro-irrigation and laying underground pipe network can ensure the soil moist during the dry season,and can save water 2-3 times than that with irrigation pipe;using film bags planting and film planting method can save water about one time.%为了进行水利改良与利用沙地,在辽宁省彰武县阿尔乡建立了试验示范区。试验表明,推平沙丘,可以改善沙地水分状况,提高土壤含水率0.9%~1.3%,沙地利用面积扩大25%~30%;利用地下水,打机井,每3.3 hm2分布一眼,出水量每小时7 t,灌溉农田、药圃、苗圃和速生林;实施微润灌溉,铺设地下管网,保障在旱季土壤湿润,比管道灌水节水2~3倍;实行膜袋植树与覆膜植树法,可节水1倍左右。

  9. On the study of ricochet and penetration in sand, water and gelatin by spheres, 7.62 mm APM2, and 25 mm projectiles

    Directory of Open Access Journals (Sweden)

    John F. Moxnes

    2016-04-01

    Full Text Available We examine the ricochet and penetration behavior in sand, water and gelatin by steel spheres, 7.62 mm APM2 and 25 mm projectiles. A threshold impact angle (critical angle exists beyond which ricochet cannot occur. The Autodyn simulation code with the smooth particle hydrodynamic (SPH method and Impetus Afea Solver with the corpuscular model are used and the results are compared with experimental and analytical results. The resistance force in sand for spheres was proportional to a term quadratic in velocity plus a term linear in velocity. The drag coefficient for the quadratic term was 0.65. The Autodyn and Impetus Afea codes simulate too large penetration due to the lack of a linear velocity resistance force. Critical ricochet angles were consistent with analytical results in the literature. In ballistic gelatin at velocities of 50–850 m/s a drag coefficient of 0.30 fits the high speed camera recordings if a linear velocity resistance term is included. However, only a quadratic velocity resistance force with drag coefficient that varies with the Reynolds number also fits the measurements. The simulation of a sphere in water with Autodyn showed too large drag coefficient. The 7.62 mm APM2 core simulations in sand fit reasonable well for both codes. The 25 mm projectile ricochet simulations in sand show consistency with the high speed camera recordings. Computer time was reduced by one to two orders of magnitudes when applying the Impetus Afea Solver compared to Autodyn code due to the use of the graphics processing units (GPU.

  10. On the study of ricochet and penetration in sand, water and gelatin by spheres, 7.62 mm APM2, and 25 mm projectiles

    Institute of Scientific and Technical Information of China (English)

    John F. MOXNES; Øyvind FRØYLAND; Stian SKRIUDALEN; Anne K. PRYTZ; Jan A. TELAND; Eva FRIIS; Gard ØDEGÅRDSTUEN

    2016-01-01

    We examine the ricochet and penetration behavior in sand, water and gelatin by steel spheres, 7.62 mm APM2 and 25 mm projectiles. A threshold impact angle (critical angle) exists beyond which ricochet cannot occur. The Autodyn simulation code with the smooth particle hydrodynamic (SPH) method and Impetus Afea Solver with the corpuscular model are used and the results are compared with experimental and analytical results. The resistance force in sand for spheres was proportional to a term quadratic in velocity plus a term linear in velocity. The drag coefficient for the quadratic term was 0.65. The Autodyn and Impetus Afea codes simulate too large penetration due to the lack of a linear velocity resistance force. Critical ricochet angles were consistent with analytical results in the literature. In ballistic gelatin at velocities of 50–850 m/s a drag coefficient of 0.30 fits the high speed camera recordings if a linear velocity resistance term is included. However, only a quadratic velocity resistance force with drag coefficient that varies with the Reynolds number also fits the measurements. The simulation of a sphere in water with Autodyn showed too large drag coefficient. The 7.62 mm APM2 core simulations in sand fit reasonable well for both codes. The 25 mm projectile ricochet simulations in sand show consistency with the high speed camera recordings. Computer time was reduced by one to two orders of magnitudes when applying the Impetus Afea Solver compared to Autodyn code due to the use of the graphics processing units (GPU).

  11. How current ginning processes affect fiber length uniformity index

    Science.gov (United States)

    There is a need to develop cotton ginning methods that improve fiber characteristics that are compatible with the newer and more efficient spinning technologies. A literature search produced recent studies that described how current ginning processes affect HVI fiber length uniformity index. Resul...

  12. Bioaugmentation potential of free and formulated 2,6-dichlorobenzamide (BAM) degrading Aminobacter sp. MSH1 in soil, sand and water.

    Science.gov (United States)

    Schultz-Jensen, Nadja; Aamand, Jens; Sørensen, Sebastian R

    2016-12-01

    Pesticides are used extensively worldwide, which has led to the unwanted contamination of soil and water resources. Former use of the herbicide 2,6-dichlorobenzonitrile (dichlobenil) has caused pollution of ground and surface water resources by the stable degradation product 2,6-dichlorobenzamide (BAM) in several parts of Europe, which has resulted in the costly closure of several drinking water wells. One strategy for preventing this in future is bioaugmentation using bacterial degraders. BAM-degrading Aminobacter sp. MSH1 was therefore formulated into dried beads and tests undertaken to establish their potential for use in the remediation of polluted soil, sand and water. The formulation procedure included freeze drying, combined with trehalose addition for cell wall protection, thus ensuring a high amount of viable cells following prolonged storage at room temperature. The beads were round-shaped pellets with a diameter of about 1.25 mm, a dry matter content of approximately 95 % and an average viable cell content of 4.4 × 10(9) cells/g bead. Formulated MSH1 cells led to a similar, and frequently even faster, BAM mineralisation (20-65 % (14)CO2 produced from (14)C-labelled BAM) in batch tests conducted with sand, water and different soil moisture contents compared to adding free cells. Furthermore, the beads were easy to handle and had a shelf life of several months.

  13. Conservation and reclamation at Alberta's mineable oil sands

    Energy Technology Data Exchange (ETDEWEB)

    Purdy, B.; Richens, T. [Alberta Environment, Edmonton, AB (Canada)

    2010-07-01

    The regulatory foundation for oil sands in this region is established by the Energy Resources Conservation Board, Environmental Protection and Enhancement Act (EPEA), as well as the Water Act. This presentation discussed the regulatory foundation for conservation and reclamation in the mineable oil sands region. EPEA requirements and conservation objectives were identified. EPEA conservation and reclamation requirements stipulate that an operator must conserve and reclaim and obtain a reclamation certificate. EPEA approvals that were presented compared prescriptive standards versus meeting outcomes at certification. Operational and management challenges as well as the role of research networks and multi-stakeholder organizations were also addressed. Challenge facing the industry include progressive reclamation; tailings management and process-affected water; reclamation certification; integrated landscapes; soil handling and revegetation and monitoring and research. The presentation demonstrated that reclamation begins with mine planning and ends with certification. figs.

  14. The Drainage Consolidation Modeling of Sand Drain in Red Mud Tailing and Analysis on the Change Law of the Pore Water Pressure

    Directory of Open Access Journals (Sweden)

    Chuan-sheng Wu

    2014-01-01

    Full Text Available In order to prevent the occurring of dam failure and leakage, sand-well drainages systems were designed and constructed in red mud tailing. It is critical to focus on the change law of the pore water pressure. The calculation model of single well drainage pore water pressure was established. The pore water pressure differential equation was deduced and the analytical solution of differential equation using Bessel function and Laplace transform was given out. The impact of parameters such as diameter d, separation distance l, loading rate q, and coefficient of consolidation Cv in the function on the pore water pressure is analyzed by control variable method. This research is significant and has great reference for preventing red mud tailings leakage and the follow-up studies on the tailings stability.

  15. Characterization of organic composition in snow and surface waters in the Athabasca Oil Sands Region, using ultrahigh resolution Fourier transform mass spectrometry.

    Science.gov (United States)

    Yi, Y; Birks, S J; Cho, S; Gibson, J J

    2015-06-15

    This study was conducted to characterize the composition of dissolved organic compounds present in snow and surface waters in the Athabasca Oil Sands Region (AOSR) with the goal of identifying whether atmospherically-derived organic compounds present in snow are a significant contributor to the compounds detected in surface waters (i.e., rivers and lakes). We used electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR MS) to characterize the dissolved organic compound compositions of snow and surface water samples. The organic profiles obtained for the snow samples show compositional differences between samples from near-field sites (surface water samples in the AOSR. The composition of dissolved organic compounds at the upstream Athabasca River site (i.e., Athabasca River at Athabasca) is found to be different from samples obtained from downstream sites in the vicinity of oil sands operations (i.e., Athabasca River at Fort McMurray and Athabasca River at Firebag confluence). The upstream Athabasca River sites tended to share some compositional similarities with far-field snow deposition, while the downstream Athabasca River sites are more similar to local lakes and tributaries. This contrast likely indicates the relative role of regional snowmelt contributions to the Athabasca River vs inputs from local catchments in the reach downstream of Fort McMurray.

  16. Proceedings of the CEMA reclamation workshop on creating wetlands in the oil sands : final report

    Energy Technology Data Exchange (ETDEWEB)

    Bacon, L. (comp.)

    2006-08-15

    The Creating Wetlands in the Oil Sands Reclamation workshop was held to solicit expert views from leading authorities in a number of disciplines related to the creation and study of wetlands, as well as to investigate challenges in the creation of wetlands in reclaimed oil sands landscapes. This document provided a detailed transcript of each presentation and all discussions that followed. The workshop was divided into 5 sessions: (1) wetlands background information; (2) groundwater conditions and boreal wetlands; (3) creating wetland types; (4) wildlife in boreal wetlands and traditional environmental knowledge; and (5) treatment wetlands. An expert panel overview provided presentations on post-mining restoration of boreal landscapes in oil sands regions; the creation of fens, marshes and shallow water wetlands at oil sands sites and the restoration of damaged peatlands. A outline of the physical scale of the oil sands mining disturbances was provided during the first session, as well a review of regulatory requirements for reclamation. A general overview of the chemical and biological properties of the process-affected waters from oil sands mining was provided. First Nations groups present at the workshop advised that research on muskeg should be a priority. Requirements for wetland development were reviewed. It was noted that climate, substrate and position on the landscape are important factors in the development of engineered wetlands. It was concluded that recent research activities have contributed to greater overall confidence that wetlands creation will become a successful reclamation strategy. While there are many variables beyond the control of reclamation management capabilities, important factors such as water chemistry, water level fluctuation and the amounts of nutrients within a wetlands system can be successfully managed in restoration scenarios. A total of 16 papers were presented.

  17. Groundwater Discharges to Rivers in the Western Canadian Oil Sands Region

    Science.gov (United States)

    Ellis, J.; Jasechko, S.

    2016-12-01

    Groundwater discharges into rivers impacts the movement and fate of nutrients and contaminants in the environment. Understanding groundwater-surface water interactions is especially important in the western Canadian oil sands, where groundwater contamination risks are elevated and baseline water chemistry data is lacking, leading to substantial uncertainties about anthropogenic influences on local river quality. High salinity groundwater springs sourced from deep aquifers, comprised of Pleistocene-aged glacial meltwater, are known to discharge into many rivers in the oil sands. Understanding connections between deep aquifers and surficial waterways is important in order to determine natural inputs into these rivers and to assess the potential for injected wastewater or oil extraction fluids to enter surface waters. While these springs have been identified, their spatial distribution along rivers has not been fully characterized. Here we present river chemistry data collected along a number of major river corridors in the Canadian oil sands region. We show that saline groundwater springs vary spatially along the course of these rivers and tend to be concentrated where the rivers incise Devonian- or Cretaceous-aged aquifers along an evaporite dissolution front. Our results suggest that water sourced from Devonian aquifers may travel through bitumen-bearing Cretaceous units and discharge into local rivers, implying a strong groundwater-surface water connection in specialized locations. These findings indicate that oil sands process-affected waters that are injected at depth have the potential to move through these aquifers and reach the rivers at the surface at some time in the future. Groundwater-surface water interactions remain key to understanding the risks oil sands activities pose to aquatic ecosystems and downstream communities.

  18. Technology Status of Extracting Bitumen from Oil Sand using Hot alkaline Water%油砂沥青热碱水萃取分离技术现状

    Institute of Scientific and Technical Information of China (English)

    罗茂; 耿安松; 廖泽文

    2011-01-01

    作为非常规石油资源的油砂受到愈来愈多的重视.本文评述了世界油砂资源开发现状和中国油砂资源的利用前景,总结了工业上成熟的油砂沥青热碱水萃取技术分离沥青的流程,论述了热碱水萃取过程中沥青与矿物、粘土和气泡之间相互作用及其对沥青分离效率的影响;全面总结了油砂沥青热碱水萃取过程中温度、pH值、多价阳离子和加工助剂等物理化学条件对沥青与矿物之间相互作用和沥青有效分离的影响.最后指出油砂沥青热碱水萃取分离的最优化实验技术研究是值得进一步深入研究的方向,原子力显微镜的运用和不同萃取技术的综合运用将在改善沥青的萃取分离效果上发挥作用.%As an unconventional fuel resource, tar sand is widely considered to be an important supplement for oil production in the near future due to the skyrocketing price of crude oil and the increasing demand of fuel resources in the world. This paper reviewed oil sand utilization worldwide and the prospect of oil sand exploitation in China.The commercial procedures for hot water based bitumen extraction and subsequent bitumen purification were reviewed. Interactions of bitumen-minerals, bitumen-clay and bitumen-gas bubbles were discussed. The effect of various physical, chemical parameters, such as water temperature, pH value, metal ions in the slurring water and various processing additives, to the interactions of bitumen-mineral and the final recovery of bitumen is systematically summarized. The reviewers believed that finding optimized technique for the hot water based bitumen extraction and separation will be a potential future research focus, and believed that application of Atom Force Microscopy and synthetic utilization of various extraction methods will play an important role in enhancing oil sand bitumen extraction.

  19. Sands styrke

    DEFF Research Database (Denmark)

    Jacobsen, H. Moust; Jørgensen, Mogens B.; Poulsen, H. Serup

    1975-01-01

    På grundlag af triaxialforsøg med D=7 og 20 cm og varierende højde på løse og faste lejringer af Blokhussand kan effekten af varierende højde-breddeforhold og spændingsniveau samt skalaeffekten bestemmes. Ved sammenligning med pladeforsøg med overfladelast op til 8 t/m2 kan den almindelige fremga...... fremgangsmåde ved bæreevneberegninger på sand undersøges....

  20. Relating dynamic conditions to the performance of biological rapid sand filters used to remove ammonium, iron, and manganese from drinking water

    DEFF Research Database (Denmark)

    Lee, Carson; Albrechtsen, Hans-Jørgen; Smets, Barth F.

    months at similar operating conditions as the full scale filter to validate the performance of the pilot columns. After this, the pilot columns were fed with varying loading rates of iron, ammonium, and manganese. To fully examine the changes in filter performance several parameters were analyzed. Water......Biological rapid sand filters are used throughout the world to remove both particulates and dissolved compounds from drinking water and is a proven and effective treatment technique for providing safe and secure drinking water. However, experience has shown that some filters have problems...... consistently meeting regulatory guidelines for compounds like ammonium and reduced forms of iron and manganese. These compounds can cause biological instability in the distribution system and can lead to many problems including the growth of pathogens and aesthetic problems (taste, odor, and color...

  1. Sand harm in taklimakan Desert highway and sand control

    Institute of Scientific and Technical Information of China (English)

    HANZhiwen; WANGTao; SUNQingwei; DONGZhibao; WANGXunming

    2003-01-01

    Reputed as a wonderful achievement of the world’s highway construction history,the Taklimakan Desert highway is nor facing serious sand drift encroachment problems due to its 447-km-long passage of sand sea consisting of crescent dunes,barchan chains,compound transverse dune ridges and complex megadunes.To solve some technical problems in the protection of the highway from sang drift encroachment,desert experts have been conducting the theoretical and applied studies on sand movement laws;causes,severities and time-space differentiation of sand drift damages;and control ways including mechanical,chemical and biological measures.In this paper the authors give an overall summry on the research contents and recent progress in the control of sand drift damages in China and hold that the theoretical researc results and practices in the prevention of sand drift encroachment on the cross-desert highway represnt a breakthrough and has an cpoch-making significance.Since the construction of protective forest along the cross-desert highway requires large amount of ground water,what will be its environmental consequence and whether it can effectively halt sand drift encroachment on the highway forever are the questions to be studied urgently.

  2. Modeling the simultaneous transport of silver nanoparticles and dissolved silver ions in water-saturated sand columns

    Science.gov (United States)

    Taghavy, A.; Wang, Y.; Mittelman, A.; Becker, M. D.; Pennell, K. D.; Abriola, L. M.

    2011-12-01

    Concerns over the potential adverse impacts of nanosilver particles (nAg) on human health and the environment have arisen based upon their widespread use in various commercial and biomedical products. In addition, in situ dissolution of deposited nAg could enhance its environmental impact through the formation of dissolved silver ion (Ag+) plumes. A hybrid mathematical model is presented that simulates the simultaneous reactive transport of nAg/Ag+ in porous media. The simulator couples a Lagrangian Random Walk-based Particle Tracking (RWPT) method for nAg transport with a conventional Eulerian Finite Differencing (FD) scheme for the reactive transport of dissolved solutes. In the absence of oxidants other than dissolved oxygen (DO), nAg is assumed to dissolve via a cooperative oxidation reaction with DO and proton ions (H+), and dissolution is modeled by a first-order kinetic expression. An existing empirical correlation is implemented for evaluation of the dissolution rate constant from physiochemical characteristics of the system and nanoparticles, including solution pH, particle specific surface area (SSA), and temperature. The hybrid modeling approach enables the consideration of different particle size classes and the associated particle-specific dissolution rates. The utility of simulator is demonstrated by modeling results obtained from nAg/ Ag+ transport studies performed in ca. 10.8-cm long borosilicate glass columns with an inside diameter of 2.5 cm. Three column experiments were performed at a constant flow rate, yielding a particle approach velocity of 7.68±0.04 m/day, at dissolved oxygen concentrations ranging from 1.65 mg/L to 8.99 mg/L. A 3 pore volume pulse of nAg suspension, containing 3.17±0.07 mg/L total Ag and 10mM NaNO3 at pH 7.07, was injected into water-saturated columns packed with washed 40-50 mesh Ottawa sand. Following nAg injection, the columns were flushed with nAg-free background solution for an additional 3 pore volumes, which

  3. Evaluation of Turf-Grass and Prairie-Vegetated Rain Gardens in a Clay and Sand Soil, Madison, Wisconsin, Water Years 2004-08

    Science.gov (United States)

    Selbig, William R.; Balster, Nicholas

    2010-01-01

    The U.S. Geological Survey, in cooperation with a consortium of 19 cities, towns, and villages in Dane County, Wis., undertook a study to compare the capability of rain gardens with different vegetative species and soil types to infiltrate stormwater runoff from the roof of an adjacent structure. Two rain gardens, one planted with turf grass and the other with native prairie species, were constructed side-by-side in 2003 at two locations with different dominant soil types, either sand or clay. Each rain garden was sized to a ratio of approximately 5:1 contributing area to receiving area and to a depth of 0.5 foot. Each rain garden, regardless of vegetation or soil type, was capable of storing and infiltrating most of the runoff over the 5-year study period. Both rain gardens in sand, as well as the prairie rain garden in clay, retained and infiltrated 100 percent of all precipitation and snowmelt events during water years 2004-07. The turf rain garden in clay occasionally had runoff exceed its confining boundaries, but was still able to retain 96 percent of all precipitation and snowmelt events during the same time period. Precipitation intensity and number of antecedent dry days were important variables that influenced when the storage capacity of underlying soils would become saturated, which resulted in pooled water in the rain gardens. Because the rooftop area that drained runoff to each rain garden was approximately five times larger than the area of the rain garden itself, evapotranspiration was a small percentage of the annual water budget. For example, during water year 2005, the maximum evapotranspiration of total influent volume ranged from 21 percent for the turf rain garden in clay to 25 percent for the turf rain garden in sand, and the minimum ranged from 12 percent for the prairie rain garden in clay to 19 percent for the prairie rain garden in sand. Little to no runoff left each rain garden as effluent and a small percentage of runoff returned to the

  4. 锰砂/石英砂滤池与纳滤膜组合工艺去除水中砷的研究%Study on the combined process of manganese sand/quartz sand filter and nanofiltration membrane to remove the arsenic in water

    Institute of Scientific and Technical Information of China (English)

    郭成会; 张维佳; 夏圣骥

    2011-01-01

    In this paper by employing the combined process of manganese sand/quartz sand filter and nanofiltration membrane to remove the arsenic in water, and the arsenic removal effects of manganese sand/quartz sand, nanofiltration membrane (NF90, HL), and combined process of manganese sand/quartz sand and nanofiltration were studied. The result showed that As ( Ⅲ ) and As( V )could be removed effectively by manganese sand/quartz sand filtration, and the effluent arsenic concentration could be less than 50 μg/L when the influent arsenic concentration was 250 μg/L; nanofiltration membrane could remove As(V) more than 90%, but only remove As(Ⅲ)about 40~60%; combined process of manganese sand/quartz sand and nanofiltration had strong removal effect of arsenic in water, and the arsenic concentration in effluent was less than 10 μg/L,which demonstrated that the combined process was an ideal process to remove arsenic in water.%采用锰砂/石英砂滤池与纳滤膜组合工艺处理含砷水,考察锰砂/石英砂、纳滤膜(NF90、HL)、锰砂/石英砂滤池与纳滤膜组合工艺对水中砷的去除效果.结果表明,三价砷(As(Ⅲ))和五价砷(As(Ⅴ))经锰砂/石英砂过滤后能得到很好的去除,原水砷浓度250 μg/L,出水砷浓度小于50μg/L;纳滤膜对五价砷(As(Ⅴ))的去除能力很高,能达到90%以上,但是对三价砷(As(Ⅲ))的去除率不理想,为40%~60%;锰砂/石英砂复合滤池与纳滤膜组合工艺对水中砷有很好的去除效果,出水砷浓度均小于10μg/L,是理想的饮用水除砷方法.

  5. Effect of ground-water recharge on configuration of the water table beneath sand dunes and on seepage in lakes in the sandhills of Nebraska, U.S.A.

    Science.gov (United States)

    Winter, T.C.

    1986-01-01

    Analysis of water-level fluctuations in about 30 observation wells and 5 lakes in the Crescent Lake National Wildlife Refuge in the sandhills of Nebraska indicates water-table configuration beneath sand dunes in this area varies considerably, depending on the configuration of the topography of the dunes. If the topography of an interlake dunal area is hummocky, ground-water recharge is focused at topographic lows causing formation of water-table mounds. These mounds prevent ground-water movement from topographically high lakes to adjacent lower lakes. If a dune ridge is sharp, the opportunity for focused recharge does not exist, resulting in water-table troughs between lakes. Lakes aligned in descending altitudes, parallel to the principal direction of regional ground-water movement, generally have seepage from higher lakes toward lower lakes. ?? 1986.

  6. Pattern formation - Instabilities in sand ripples

    DEFF Research Database (Denmark)

    Hansen, J. L.; v. Hecke, M.; Haaning, A.

    2001-01-01

    Sand ripples are seen below shallow wavy water and are formed whenever water oscillates over a bed of sand. Here we analyse the instabilities that can upset this perfect patterning when the ripples are subjected to large changes in driving amplitude or frequency, causing them to deform both...

  7. Modelling the spectral induced polarization response of water-saturated sands in the intermediate frequency range (102-105 Hz) using mechanistic and empirical approaches

    Science.gov (United States)

    Kremer, Thomas; Schmutz, Myriam; Leroy, Philippe; Agrinier, Pierre; Maineult, Alexis

    2016-11-01

    The intermediate frequency range 102-105 Hz forms the transition range between the spectral induced polarization frequency domain and the dielectric spectroscopy frequency domain. Available experimental data showed that the spectral induced polarization response of sands fully saturated with water was particularly sensitive to variations of the saturating water electrical conductivity value in the intermediate frequency range. An empirical and a mechanistic model have been developed and confronted to this experimental data. This confrontation showed that the Maxwell Wagner polarization alone is not sufficient to explain the observed signal in the intermediate frequency range. The SIP response of the media was modelled by assigning relatively high dielectric permittivity values to the sand particle or high effective permittivity values to the media. Such high values are commonly observed in the dielectric spectroscopy literature when entering the intermediate frequency range. The physical origin of these high dielectric permittivity values is discussed (grain shape, electromagnetic coupling), and a preliminary study is presented which suggests that the high impedance values of the non-polarizable electrodes might play a significant role in the observed behaviour.

  8. It's in the sand

    OpenAIRE

    Mitchell, Clive

    2016-01-01

    Sand is sand isn’t it? Sand gets everywhere but rather than a nuisance it is a valuable, high-purity raw material. Clive Mitchell, Industrial Minerals Specialist at the British Geological Survey (BGS), talks us through what sand is, what it can be used for and how to find it. His exploration of sand takes us from the deserts of Arabia to the damp sand pits of Mansfield!

  9. Trinarization of μX-ray CT images of partially saturated sand at different water-retention states using a region growing method

    Energy Technology Data Exchange (ETDEWEB)

    Higo, Yosuke, E-mail: higo.yohsuke.5z@kyoto-u.ac.jp [Department of Urban Management, Kyoto University (Japan); Oka, Fusao [Professor Emeritus, Kyoto University (Japan); Morishita, Ryoichi; Matsushima, Yoshiki; Yoshida, Tatsuya [Department of Civil and Earth Resources Engineering, Kyoto University (Japan)

    2014-04-01

    The trinarization of micro-computed tomography (CT) images for partially saturated soils at different water-retention states has been performed to clearly identify the three phases, i.e., the soil particles, the pore water and the pore air. We have proposed a trinarization technique for partially saturated soils whose histograms of the gray values for the three phases overlap each other. The segmentation method used in this study is the region growing method that ensures the spatial continuity of the phases extracted by the segmentation. Micro CT images of a dense sand specimen during the wetting process in a water retention test have been obtained. It has been found that the trinarization of the CT images in a high pore saturation regime provides reasonable results, while that in a low pore saturation regime overestimates the local void ratio. This is because the gray values of the mixels of the soil particle phase and the air phase, due to the partial volume effect, are similar to those of the water phase. It is necessary, therefore, to validate the trinarization results, by a comparison with the test results, because it is difficult to theoretically evaluate the partial volume effect. The correction of the tolerance value for the low pore saturation case with validation has provided better trinarization results. Through the trinarized CT images, the form of the existing pore water at different water-retention states has been discussed.

  10. Preliminary risk assessment of the wet landscape option for reclamation of oil sands mine tailings: bioassays with mature fine tailings pore water.

    Science.gov (United States)

    Madill, R E; Orzechowski, M T; Chen, G; Brownlee, B G; Bunce, N J

    2001-06-01

    Chemical and biological assays have been carried out on the "pore water" that results from the settling of the tailings that accompany bitumen recovery from the Athabasca oil sands. Examination of the nonacidic extracts of pore water by gas chromatography-mass spectroscopy allowed the identification of numerous two- to three-ring polycyclic aromatic compounds (PACs), to a total concentration of 2.6 micrograms/L of pore water. The PACs were biodegraded by microflora naturally present in the pore water. Acute toxicity was associated principally with the acidic fraction (naphthenic acids) of pore water extracts according to the Microtox assay; other work has shown that acute toxicity dissipates fairly rapidly. Both individual PACs and concentrated pore water extracts showed minimal levels of binding to the rat Ah receptor and induced minimal ethoxyresorufin-O-deethylase activity in primary rat hepatocytes, showing an insignificant risk of inducing monooxygenase activity. Taken together with previous work showing negligible mutagenic activity of these extracts, we conclude that it should be possible to develop tailing slurries into biologically productive artificial lakes.

  11. Liquefaction of Sand under Low Confining Pressure

    Institute of Scientific and Technical Information of China (English)

    YANG Shaoli; Rolf Sandven; Lars Grande

    2003-01-01

    Undrained behaviour of sand under low cell pressure was studied in static and cyclic triaxial tests. It was found that very loose sand liquefies under static loading with the relative density being a key parameter for the undrained behaviour of sand. In cyclic triaxial tests, pore water pressures built up during the cyclic loading and exceeded the confining cell pressure. This process was accompanied by a large sudden increase in axial deformation. The necessary number of cycles to obtain liquefaction was related to the confining cell pressure, the amplitude of cyclic loading and the relative density of sand.In addition, the patterns of pore water pressure response are different from those of sand samples with different relative densities. The test results are very useful for expounding scour mechanism around coastal structures since they relate to the low stress behaviour of the sand.

  12. Uranium and thorium in soils, mineral sands, water and food samples in a tin mining area in Nigeria with elevated activity.

    Science.gov (United States)

    Arogunjo, A M; Höllriegl, V; Giussani, A; Leopold, K; Gerstmann, U; Veronese, I; Oeh, U

    2009-03-01

    The activity concentrations of uranium and thorium have been determined in soils and mineral sands from the Nigerian tin mining area of Bisichi, located in the Jos Plateau, and from two control areas in Nigeria (Jos City and Akure) using high-purity germanium detectors (HPGe). High resolution sector field inductively coupled plasma mass spectroscopy (HR-SF-ICP-MS) was used to determine uranium and thorium in liquids and foodstuffs consumed locally in the mining area. The activities of uranium and thorium measured in the soils and mineral sands from Bisichi ranged from 8.7 kBq kg(-1) to 51 kBq kg(-1) for (238)U and from 16.8 kBq kg(-1) to 98 kBq kg(-1) for (232)Th, respectively. These values were significantly higher than those in the control areas of Jos City and Akure and than the reference values reported in the literature. They even exceeded the concentrations reported for areas of high natural radioactive background. Radionuclide concentrations in samples of the local foodstuffs and in water samples collected in Bisichi were found to be higher than UNSCEAR reference values. The results reveal the pollution potential of the mining activities on the surrounding areas.

  13. Determination of application possibilities of microwave heating in the curing process of water glass molding sands with fluid esters. Part 1

    Directory of Open Access Journals (Sweden)

    K. Granat

    2009-01-01

    Full Text Available This article presents results of the experimental trial of combination of the chemical method of water glass molding sands’ curing, used in foundry industry, with an innovative microwave heating. The research objective was to indicate at new areas of microwave energy application. The sands prepared, according to recommendations for curing technology, with the use of ethylene glycol diacetate, have been subject to microwave influence. The attempt at determination of microwave influence on qualitative changes of the binding bridges created during the curing process concerned such parameters as: bending and tensile strength, permeability as well as wear resistance. Moreover,we also determined the influence of microwave curing on the phenomena accompanying the process as well as bond stability (storage time of the prepared molding and core sands. It has been found, basing on the result analysis, that the innovative microwave heating might constitute a very good supplementation of the ester curing method. The advantages of the combined chemical and microwave gelation process include, among others, improvement of the described resistance and technological parameters as well as significant decrease of preparation time of foundry moulds and cores. The subject discussed in this article will be continued in its second part.

  14. Dynamics in Sand of Fecal Indicator Bacteria (FIB) and Salmonella From Contaminated Water, Runoff, and Sewage in an Urbanized Southern California Shoreline

    Science.gov (United States)

    Mika, K.; Lee, C.; Lin, C.; Imamura, G.; Chang, C.; Jay, J.

    2007-12-01

    In urbanized coastal watersheds, FIB can come from a variety of sources, including contaminated freshwater sources such as storm drains or creeks, sewage spills, and overlying waterbodies. To investigate the impact of these sources on bacterial levels in coastal sediments and resultant impacts on water bodies, we studied these three source types in Southern California. First, we sampled at 8am and noon at three locations throughout the summer at an enclosed beach on Avalon Bay, Catalina Island, in collaboration with Southern California Coastal Water Research Project. Using membrane filtration and IDEXX substrate technology, we measured FIB levels in sediment and water and observed a positive correlation between these two factors. Second, we studied bacterial persistence in sediment using human sewage as source. To study bacterial survival in the natural environment, we tested solar disinfection with raking as a disinfection procedure after a large sewage spill in the Los Angeles area. First order decay constants for the E. coli ranged between -0.23 and -1.02 in test plots. Further bench scale studies were conducted to determine the effect of various factors on inactivation kinetics. Decay constants measured in controlled experiments in both February and June on the rooftop ranged from -0.73 to -1.54 even though both temperature and intensity of sunlight varied greatly in these months. Interestingly, microcosms subjected to constant moisture had similar decay constants for enterococci, while E. coli in moistened sand showed very low decay rates. Finally, we further investigated effects of sunlight by assessing the extent of surface sand contamination near two contaminated freshwater sources, one under constant shading, and looked for evidence of human fecal matter.

  15. Estimation of vanadium water quality benchmarks for the protection of aquatic life with relevance to the Athabasca Oil Sands region using species sensitivity distributions.

    Science.gov (United States)

    Schiffer, Stephanie; Liber, Karsten

    2017-06-21

    Elevated vanadium (V) concentrations in oil sands coke, which is produced and stored on site of some major Athabasca Oil Sands companies, could pose a risk to aquatic ecosystems in northern Alberta, Canada, depending on its future storage and utilization. In the present study, V toxicity was determined in reconstituted Athabasca River water to various freshwater organisms, including 2 midge species (Chironomus dilutus and Chironomus riparius; 4-d and 30-d to 40-d exposures) and 2 freshwater fish species (Oncorhynchus mykiss and Pimephales promelas; 4-d and 28-d exposures) to facilitate estimation of water quality benchmarks. The acute toxicity of V was 52.0 and 63.2 mg/L for C. dilutus and C. riparius, respectively, and 4.0 and 14.8 mg V/L for P. promelas and O. mykiss, respectively. Vanadium exposure significantly impaired adult emergence of C. dilutus and C. riparius at concentrations ≥16.7 (31.6% reduction) and 8.3 (18.0% reduction) mg/L, respectively. Chronic toxicity in fish presented as lethality, with chronic 28-d LC50s of 0.5 and 4.3 mg/L for P. promelas and O. mykiss, respectively. These data were combined with data from the peer-reviewed literature, and separate acute and chronic species sensitivity distributions (SSDs) were constructed. The acute and chronic hazardous concentrations endangering only 5% of species (HC5) were estimated as 0.64 and 0.05 mg V/L, respectively. These new data for V toxicity to aquatic organisms ensure that there are now adequate data available for regulatory agencies to develop appropriate water quality guidelines for use in the Athabasca Oil Sands region and elsewhere. Until then, the HC5 values presented in the present study could serve as interim benchmarks for the protection of aquatic life from exposure to hazardous levels of V in local aquatic environments. Environ Toxicol Chem 2017;9999:1-11. © 2017 SETAC. © 2017 SETAC.

  16. Formation mechanism of cracks in saturated sand

    Institute of Scientific and Technical Information of China (English)

    Xiaobing Lu; Zhemin Zheng; Yongren Wu

    2006-01-01

    The formation mechanism of "water film" (or crack) in saturated sand is analyzed theoretically and numerically.The theoretical analysis shows that there will be no stable "water film" in the saturated sand if the strength of the skeleton is zero and no positions are choked.It is shown by numerical simulation that stable water films initiate and grow if the choking state keeps unchanged once the fluid velocities decrease to zero in the liquefied sand column.The developments of "water film" based on the model presented in this paper are compared with experimental results.

  17. Assessing environmental impacts of inland sand mining in parts of ...

    African Journals Online (AJOL)

    Assessing environmental impacts of inland sand mining in parts of Ogun State, Nigeria. ... Sand is a valuable resource for construction and other purposes, however ... Natural resources particularly, land, water quality and quantity, air quality, ...

  18. Industrial sand and gravel

    Science.gov (United States)

    Dolley, T.P.

    2013-01-01

    Domestic production of industrial sand and gravel in 2012 was about 49.5 Mt (55 million st), increasing 13 percent compared with that of 2011. Some important end uses for industrial sand and gravel include abrasives, filtration, foundry, glassmaking, hydraulic fracturing sand (frac sand) and silicon metal applications.

  19. Immediate effect of simulated sand mining on the variation of bacterial parameters in coastal waters of Kalbadevi Bay, Ratnagiri

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, C.E.G.; Das, A.; Naik, S.S.; Sharma, R.; LokaBharathi, P.A.

    The variation in bacterial parameters of coastal waters and sediments of Kalbadevi Bay, Ratnagiri, Maharashtra, India was examined for immediate response after simulated mining. Sampling was carried out at suction and disturbance points in the water...

  20. How well has biophysical research served the needs of water resource management? Lessons from the Sabie-Sand catchment

    CSIR Research Space (South Africa)

    Van Wyk, E

    2001-09-01

    Full Text Available Since the era of great water engineering works in South Africa, there has been a major shift in the thinking and approach to water resources management. Previous focus on water supply has been replaced by demand management initiatives...

  1. PROSPECTS FIXATION DRIFT SANDS PHYSICOCHEMICAL METHOD

    Directory of Open Access Journals (Sweden)

    Maujuda MUZAFFAROVA

    2016-09-01

    Full Text Available This article is based on the theoretical foundations of secure mobile sand being considered for reducing the negative impact of one of the manifestations of exogenous plains on such an important natural-technical system as a railroad. It suggests practical measures to build a system of design protection against sand drifts. The article also suggests ways to conserve resources and rational use of machinery and performers as well as the consolidation of mobile sand wet with water soluble waste of local production of waste dextrin. Consolidation is exposed on dry and wet sand.

  2. Response to Oil Sands Products Assessment

    Science.gov (United States)

    2015-09-01

    Tailings ponds are an operating facility common to all types of surface mining. For oil sands, tailings consisting of water , sand, clay, and residual ...oil, are pumped to these basins—or ponds— where settling occurs and water is recycled for reuse in the process. When the ponds are no longer required...of crude oil transported by tank vessel in Washington waters . In a 2013 Bloomburg Business news article , Dan Murtaugh states, “The dock probably

  3. Sand Failure Mechanism and Sanding Parameters in Niger Delta Oil Reservoirs

    Directory of Open Access Journals (Sweden)

    Sunday Isehunwa,

    2010-05-01

    Full Text Available Sand production is a major issue during oil and gas production from unconsolidated reservoirs. In predicting the onset of sand production, it is important to accurately determine the failure mechanism and the contributing parameters. The aim of this study was to determine sand failure mechanism in the Niger-Delta, identify themajor contributing parameters and evaluate their effects on sanding.Completion and production data from 78 strings completed on 22 reservoirs in a Niger Delta oil Field were evaluated. Sand failure mechanisms and contributing parameters were identified and compared with published profiles. The results showed that cohesive stress is the predominant sand failure mechanism. Water cut, bean size and gas oil ratio (GOR impact sand production in the Niger Delta.

  4. Development of ground water from the Carrizo sand and Wilcox group in Dimmit, Zavala, Maverick, Frio, Atacosa, Median, Bexar, Live Oak, McMullen, La Salle, and Webb Counties, Texas

    Science.gov (United States)

    Moulder, E.A.

    1957-01-01

    The development of ground water for irrigation from the Carrizo sand south and southwest of San Antonio, Tex., has increased rapidly during the past few years. Declining pumping water levels in irrigation wells, caused by increased withdrawals, have caused considerable concern among the residents of the area. In response, the Nueces River Conservation and Reclamation District entered into a cooperative agreement with the Texas Board of Water Engineers and the United States Geological Survey to determine the extent of development and the rate of withdrawal that has cause the decline. All wells that discharged more than 150 gallons per minute for extended periods of time in 1955 from either the Carrizo sand or sands of the Wilcox group were studied and are shown on [late 1. Estimates were made of the total withdrawals by county and are given in table 2. Similar estimates of withdrawals in some of the counties for the irrigation years 1929-30, 1938-39, 1944-45, and 1947-48 are presented for comparison in table 3. Although the Carrizo sand is the principal source of ground water pumped in the area, estimate of withdrawals of water from the Wilcox were included in this inventory because (1) the formation appears to be hydraulically connected to the Carrizo sand, (2) the quality of water generally is good in the outcrop area of the Wilcox, and (3) appreciable withdrawals are being made from the Wilcox for irrigation in a few areas. The investigation covered an area of about 7,500 square miles and included all or parts of the following counties: Dimmit, Zavala, Maverick, Frio, Atascosa, Medina, Bexar, Live Oak, McMullen, La Salle, and Webb (fig. 1).

  5. Eastern Scheldt Sand, Baskarp Sand No. 15

    DEFF Research Database (Denmark)

    Andersen, A. T; Madsen, E. B.; Schaarup-Jensen, A. L.

    The present data report contains data from 13 drained triaxial tests, performed on two different sand types in the Soil Mechanics Laboratory at Aalborg University in March, 1997. Two tests have been performed on Baskarp Sand No. 15, which has already ken extensively tested in the Soil Mechanics...... Laboratory. The remaining 11 triaxial tests have ben performed on Eastern Scheldt Sand, which is a material not yet investigated at the Soil Mechanics Laboratory. In the first pari of this data report, the characteristics of the two sand types in question will be presented. Next, a description...

  6. Experimental research of MgSO4 water soluble sand core hardened by twice microwave heating%二次微波加热制备硫酸镁水溶性砂芯试验研究

    Institute of Scientific and Technical Information of China (English)

    何家庆; 樊自田; 刘鑫旺; 刘富初

    2014-01-01

    Twice microwave heating technology was applied to harden MgSO4 water soluble sand core , and the effect of kaolin reinforcement on properties of the core was tested .The performance character-istics of the MgSO4 water soluble sand core were also analyzed and compared with sodium silicate sand hardened by twice microwave heating technology .Scanning electron microscope (SEM ) was used to investigate the micro-morphology of the MgSO4 water soluble sand core ,and the optimized water sol-uble sand core was applied to cast AZ91D alloy .The results indicate that the MgSO4 water soluble sand core hardened by twice microwave heating technology has advantages of high tensile strength , excellent surface stability ,good humidity resistance ,and high removability by collapsing in the wa-ter ,which has good application prospects .The SEM analysis demonstrates that with the addition of kaolin ,there are less cracks and holes in the binder bridge of the water soluble sand core ,and the mixed-mode fracture mechanism is instead of the cohesive fracture mechanism .%采用二次微波加热工艺制备硫酸镁水溶性砂芯,测试研究了增强剂高岭土对硫酸镁水溶性砂芯性能的影响,对比分析了二次微波加热制备的硫酸镁水溶性砂芯和二次微波硬化水玻璃砂的性能特征,通过扫描电子显微镜(SEM )分析了硫酸镁水溶性砂芯的微观形貌,采用优化配方的硫酸镁水溶性砂芯进行了AZ91D的浇铸试验.试验结果表明:二次微波加热制备的硫酸镁水溶性砂芯具有较高的抗拉强度、表面安定性和抗吸湿性,砂芯铸后的水溶溃散性良好,具有良好的应用前景.SEM分析结果表明:加入高岭土后水溶性砂芯粘结桥中的裂纹和孔隙减少,断裂方式由内聚断裂变成复合断裂.

  7. Evaluation of virus removal efficiency of coagulation-sedimentation and rapid sand filtration processes in a drinking water treatment plant in Bangkok, Thailand.

    Science.gov (United States)

    Asami, Tatsuya; Katayama, Hiroyuki; Torrey, Jason Robert; Visvanathan, Chettiyappan; Furumai, Hiroaki

    2016-09-15

    In order to properly assess and manage the risk of infection by enteric viruses in tap water, virus removal efficiency should be evaluated quantitatively for individual processes in actual drinking water treatment plants (DWTPs); however, there have been only a few studies due to technical difficulties in quantifying low virus concentration in water samples. In this study, the removal efficiency of indigenous viruses was evaluated for coagulation-sedimentation (CS) and rapid sand filtration (RSF) processes in a DWTP in Bangkok, Thailand by measuring the concentration of viruses before and after treatment processes using real-time polymerase chain reaction (qPCR). Water samples were collected and concentrated from raw source water, after CS, and after RSF, and inhibitory substances in water samples were reduced by use of a hydrophobic resin (DAX-8). Pepper mild mottle virus (PMMoV) and JC polyomavirus (JC PyV) were found to be highly prevalent in raw waters, with concentrations of 10(2.88 ± 0.35) and 10(3.06 ± 0.42) copies/L (geometric mean ± S.D.), respectively. Step-wise removal efficiencies were calculated for individual processes, with some variation observed between wet and dry seasons. During the wet season, PMMoV was removed less by CS and more by RSF on average (0.40 log10 vs 1.26 log10, respectively), while the reverse was true for JC PyV (1.91 log10 vs 0.49 log10, respectively). Both viruses were removed similarly during the dry season, with CS removing the most virus (PMMoV, 1.61 log10 and 0.78 log10; JC PyV, 1.70 log10, and 0.59 log10; CS and RSF, respectively). These differences between seasons were potentially due to variations in raw water quality and the characteristics of the viruses themselves. These results suggest that PMMoV and JC PyV, which are more prevalent in environmental waters than the other enteric viruses evaluated in this study, could be useful in determining viral fate for the risk management of viruses in water treatment

  8. Comprehensive analysis of oil sands processed water by direct-infusion Fourier-transform ion cyclotron resonance mass spectrometry with and without offline UHPLC sample prefractionation.

    Science.gov (United States)

    Nyakas, Adrien; Han, Jun; Peru, Kerry M; Headley, John V; Borchers, Christoph H

    2013-05-07

    Oil sands processed water (OSPW) is the main byproduct of the large-scale bitumen extraction activity in the Athabasca oil sands region (Alberta, Canada). We have investigated the acid-extractable fraction (AEF) of OSPW by extraction-only (EO) direct infusion (DI) negative-ion mode electrospray ionization (ESI) on a 12T-Fourier transform ion cyclotron resonance mass spectrometer (FTICR-MS), as well as by offline ultrahigh performance liquid chromatography (UHPLC) followed by DI-FTICR-MS. A preliminary offline UHPLC separation into 8 fractions using a reversed-phase C4 column led to approximately twice as many detected peaks and identified compounds (973 peaks versus 2231 peaks, of which 856 and 1734 peaks, respectively, could be assigned to chemical formulas based on accurate mass measurements). Conversion of these masses to the Kendrick mass scale allowed the straightforward recognition of homologues. Naphthenic (CnH2n+zO2) and oxy-naphthenic (CnH2n+zOx) acids represented the largest group of molecules with assigned formulas (64%), followed by sulfur-containing compounds (23%) and nitrogen-containing compounds (8%). Pooling of corresponding fractions from two consecutive offline UHPLC runs prior to MS analysis resulted in ~50% more assignments than a single injection, resulting in 3-fold increase of identifications compared to EO-DI-FTICR-MS using the same volume of starting material. Liquid-liquid extraction followed by offline UHPLC fractionation thus holds enormous potential for a more comprehensive profiling of OSPW, which may provide a deeper understanding of its chemical nature and environmental impact.

  9. Responses of Caryopsis Germination, Seedling Emergence, and Development to Sand Water Content of Agropyron cristatum (L.) Gaertn. and Bromus inermis Leyss.

    Institute of Scientific and Technical Information of China (English)

    Hui-Ling YANG; Xuan-Wei ZHU; Ming DONG; Zhen-Ying HUANG; Zhi-Ping CAO

    2005-01-01

    Responses of caryopsis germination, seedling emergence, and development of Agropyron cristatum (L.) Gaertn. (Gramineae) and Bromus inermis Leyss. (Gramineae), two dominant perennial grasses in the Otindag Sandland of China, to different sand water content (SWC; 1%, 2%, 3%, 4%, 6%, 8%, 12%,16%, and 20%) were studied comparatively. The results showed that the germination responses of the two grasses to SWC were similar (i.e. caryopses could not germinate when the SWC was below 3%; at SWC ranging from 3% to 12%, the higher the SWC, the higher the germination percentage; and at a SWC of 12%20%, germination reached similarly high percentages). At a sand burial depth of 0.5 cm, the threshold of SWC for seedling emergence was 6% forA. cristatum and 8% forB. inermis; at 12%-20% SWC, the seedling emergence of both species reached similarly high percentages. The seedling growth responses of these two species to SWC gradients were different. For A. cristatum, the biomass of seedlings increased with SWC from 6% to 12%, and decreased with SWC from 12% to 20%. For B. inermis, the biomass of seedlings always increased with SWC from 8% to 20%. The results also showed that the seedlings of both species allocated more biomass to the roots with decreases in SWC. The SWC changes from April to October in natural microhabitats of both species suggested that the SWC may play an important role in caryopsis germination,seedling emergence, and the growth characteristics of the two grasses. The responses of caryopsis germination, seedling emergence, and the growth characteristics of these two species to SWC may determine their distribution patterns in the Otindag Sandland.

  10. Soil Water Repellency of Sands and Clay as Affected by Particle Size%砂土和黏土的颗粒差异对土壤斥水性的影响

    Institute of Scientific and Technical Information of China (English)

    杨松; 吴珺华; 董红艳; 张燕明

    2016-01-01

    斥水性土壤广泛存在于自然界中,并且对土壤环境和作物生长等有重要影响。建立理想化的土壤颗粒模型对砂土和黏土的斥水特性进行计算分析。结果表明:当接触角很小时,砂土中不存在斥水现象。随着接触角的增大,砂土斥水性与含水率密切相关,砂土的密实度对其斥水性也有重要影响,当砂土比较密实时,土壤的“亲水”与“斥水”特性对含水率特别敏感,随着含水率的变化,砂土可能由亲水性较好的土壤转变为斥水性土壤;当砂土比较松散时,土壤颗粒的斥水性对含水率并不敏感。当黏土接触角略小于90°且湿润半径b也较小时,黏土也存在斥水现象。如果黏土颗粒的接触角较小或接触角小于90°且湿润半径b较大,黏土总是亲水的。黏土含水率较大时,斥水特性由土壤颗粒的接触角决定。%Water-repellent soils,existing widely in nature,have some important effects on soil environment and crop growth. In order to analyze water repellency of sand and clay,models of sand and clay different in particle size were built. Results showed that no phenomenon of water repellency was found in sand soil when the contact angle of water with sand was small. Water repellency of sand soil was closely related to soil water content when the sand-water contact angle was big. Compactness of the soil was another important factor affecting soil water repellency. When the sand soil was highly compacted,whether the soil was hydrophilic or hydrophobic was very sensitive to water content,and it might switch from one state to another with changing soil water content. When the sand soil was quite loose,it was no longer sensitive to soil water content. In clay soil with soil-water contact angle being slightly less than 90°and wetting radius b being small,the phenomenon of water repellency was observed. But when the clay soil was much smaller than 90°in soil-water and

  11. Effects of solid water and foliar fertilizer on survival and growth of seedlings in sand prevention and control

    Institute of Scientific and Technical Information of China (English)

    WANG Yutao; LI Jiyue; LIU Ping

    2007-01-01

    To promote afforestation in sandy lands and increase the effects of prevention and control of desertification,the application of a new drought-resistant productsolid water and foliar fertilizer "Shifengle"-was studied.A comparison of three treatments (solid water,foliar fertilizer,and control) showed that both solid water and foliar fertilizer increased plant survival rate by 10% and 18.2%,respectively.Afforestation survival rates of Salix psammophila and Hedysarum mongolicum reached over 90%.In addition,height and crown growth as well as biomass of seedlings were improved by the treatments.

  12. Investigation on water-assisted solvent extraction of bitumen from oil sands%水辅助溶剂法提取油砂中的沥青

    Institute of Scientific and Technical Information of China (English)

    杨红强; 丁明山; 胡斌; 任嗣利

    2014-01-01

    开发了一种水辅助溶剂法从油砂中提取沥青的技术。该方法通过在油砂固相与有机溶剂间介入水层提取油砂中的沥青。以内蒙古扎赉特旗油砂矿为研究对象,考察了温度、剂砂质量比、提取时间、甲苯在复合溶剂中的含量及溶剂的种类与性质对沥青回收率高低的影响,结果表明:最佳提取条件为提取温度50℃,剂砂质量比1∶1,提取时间25min。沥青回收率与提取溶剂的性质紧密相关,水层介入有效降低了固体微粒组分在有机相中的含量,且便于后续的有机相与泥砂相的分离。通过对各种溶剂提取的沥青进行组分分析,发现各种溶剂对沥青提取能力的差异性源于溶剂的化学组成和结构不同。本文相关研究结果对溶剂法提取油砂中沥青技术及溶剂种类的选择具有指导作用。%Water-assisted solvent extraction processes (WASEPs) were developed by introducing a water layer between the oil sands and solvent to extract bitumen. The function of the introduced water layer in the WASEPs is to effectively reduce the fine solids content in the solvent phase and make it easy to separate bitumen solution from solids. Effects of the solvent type on bitumen recovery were investigated and the extraction conditions were optimized. The results showed that bitumen recovery was closely related to the solvent compositions and chemical structure. The optimal extraction condition was stirring at 50℃ for 25 minutes using a ratio of oil sands to solvent at 1∶1(wt/wt). The reason of different extraction abilities for various solvents was revealed by analyzing the component of extracted bitumen. It may be useful to guide the solvent extraction processes and solvent selection.

  13. Ostrich-Like Strategies in Sahelian Sands? Land and Water Grabbing in the Office du Niger, Mali

    Directory of Open Access Journals (Sweden)

    Thomas Hertzog

    2012-06-01

    Full Text Available In recent years, large-scale agricultural investment projects have increased in sub-Saharan Africa as a result of the growing appetites of local and international investors for land resources. Research has so far mainly focused on land issues, but the water implications of these land deals are starting to surface. Taking the Office du Niger (ON, in Mali, as a case study, we show that while around 100,000 ha is currently being cultivated, mostly by smallholders, a total of 600,000 ha of land has been allocated in the past ten years to investors in large-scale farming. This process has largely bypassed the official procedure established by the ON at regional level. The allocation of new lands has shifted to the national level, with an attempt to recentralize the management of land deals and associated benefits at the highest level, despite contrary efforts by foreign donors to strengthen the ON. This article describes the complex allocation process based on 'behind-closed-doors' negotiations. It then analyses the implications of the land deals on water issues by focusing on the strategies of actors to limit the risk of future water shortages, the current and expected difficulties in water management and allocation, and the emerging spatial and social redistribution of benefits and risk that signals a process of water grabbing.

  14. Probing the water distribution in porous model sands with two immiscible fluids: A nuclear magnetic resonance micro-imaging study

    Science.gov (United States)

    Lee, Bum Han; Lee, Sung Keun

    2017-10-01

    The effect of the structural heterogeneity of porous networks on the water distribution in porous media, initially saturated with immiscible fluid followed by increasing durations of water injection, remains one of the important problems in hydrology. The relationship among convergence rates (i.e., the rate of fluid saturation with varying injection time) and the macroscopic properties and structural parameters of porous media have been anticipated. Here, we used nuclear magnetic resonance (NMR) micro-imaging to obtain images (down to ∼50 μm resolution) of the distribution of water injected for varying durations into porous networks that were initially saturated with silicone oil. We then established the relationships among the convergence rates, structural parameters, and transport properties of porous networks. The volume fraction of the water phase increases as the water injection duration increases. The 3D images of the water distributions for silica gel samples are similar to those of the glass bead samples. The changes in water saturation (and the accompanying removal of silicone oil) and the variations in the volume fraction, specific surface area, and cube-counting fractal dimension of the water phase fit well with the single-exponential recovery function { f (t) = a [ 1 -exp (- λt) ] } . The asymptotic values (a, i.e., saturated value) of the properties of the volume fraction, specific surface area, and cube-counting fractal dimension of the glass bead samples were greater than those for the silica gel samples primarily because of the intrinsic differences in the porous networks and local distribution of the pore size and connectivity. The convergence rates of all of the properties are inversely proportional to the entropy length and permeability. Despite limitations of the current study, such as insufficient resolution and uncertainty for the estimated parameters due to sparsely selected short injection times, the observed trends highlight the first

  15. Influence green sand system by core sand additions

    OpenAIRE

    N. Špirutová; J. Beňo; V. Bednářová; J. Kříž; M. Kandrnál

    2012-01-01

    Today, about two thirds of iron alloys casting (especially for graphitizing alloys of iron) are produced into green sand systems with usually organically bonded cores. Separation of core sands from the green sand mixture is very difficult, after pouring. The core sand concentration increase due to circulation of green sand mixture in a closed circulation system. Furthermore in some foundries, core sands have been adding to green sand systems as a replacement for new sands. The goal of this co...

  16. Baskarp Sand No. 15

    DEFF Research Database (Denmark)

    Borup, Marianne; Hedegaard, Jette

    The Soil Mechanics Laboratory has started performing tests with a new sand, Baskarp No 15. Baskarp No 15 is a graded sand from Sweden. The shapes of the largest grains are round, while the small grains have sharp edges. The main part of of Baskarp No 15 is quarts, but it also contains feldspar...... and biotit. Mainly the sand will be used for tests concerning the development og the theory of building up pore pressure in sand, L. B. Ibsen 1993....

  17. Lund Sand No 0

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Jakobsen, Finn Rosendal

    During the last 15 years the Geotechnical Engineering Group (GEG) at Aalborg University has performed triaxial tests with a sand called Lund No 0. Lund No 0 is a graded sand from a gravel pit near Horsens in Denmark. For the classification of the sand the following tests have been performed: Sieve...

  18. Microbial aerobic and anaerobic degradation of acrylamide in sludge and water under environmental conditions--case study in a sand and gravel quarry.

    Science.gov (United States)

    Guezennec, A G; Michel, C; Ozturk, S; Togola, A; Guzzo, J; Desroche, N

    2015-05-01

    Polyacrylamides (PAMs) are used in sand and gravel quarries as water purification flocculants for recycling process water in a recycling loop system where the flocculants remove fine particles in the form of sludge. The PAM-based flocculants, however, contain residual amounts of acrylamide (AMD) that did not react during the polymerization process. This acrylamide is released into the environment when the sludge is discharged into a settling basin. Here, we explore the microbial diversity and the potential for AMD biodegradation in water and sludge samples collected in a quarry site submitted to low AMD concentrations. The microbial diversity, analyzed by culture-dependent methods and the denaturing gradient gel electrophoresis approach, reveals the presence of Proteobacteria, Cyanobacteria, and Actinobacteria, among which some species are known to have an AMD biodegradation activity. Results also show that the two main parts of the water recycling loop-the washing process and the settling basin-display significantly different bacterial profiles. The exposure time with residual AMD could, thus, be one of the parameters that lead to a selection of specific bacterial species. AMD degradation experiments with 0.5 g L(-1) AMD showed a high potential for biodegradation in all parts of the washing process, except the make-up water. The AMD biodegradation potential in samples collected from the washing process and settling basin was also analyzed taking into account on-site conditions: low (12 °C) and high (25 °C) temperatures reflecting the winter and summer seasons, and AMD concentrations of 50 μg L(-1). Batch tests showed rapid (as little as 18 h) AMD biodegradation under aerobic and anaerobic conditions at both the winter and summer temperatures, although there was a greater lag time before activity started with the AMD biodegradation at 12 °C. This study, thus, demonstrates that bacteria present in sludge and water samples exert an in situ and rapid

  19. Sensitivity analysis on parameters and processes affecting vapor intrusion risk.

    Science.gov (United States)

    Picone, Sara; Valstar, Johan; van Gaans, Pauline; Grotenhuis, Tim; Rijnaarts, Huub

    2012-05-01

    A one-dimensional numerical model was developed and used to identify the key processes controlling vapor intrusion risks by means of a sensitivity analysis. The model simulates the fate of a dissolved volatile organic compound present below the ventilated crawl space of a house. In contrast to the vast majority of previous studies, this model accounts for vertical variation of soil water saturation and includes aerobic biodegradation. The attenuation factor (ratio between concentration in the crawl space and source concentration) and the characteristic time to approach maximum concentrations were calculated and compared for a variety of scenarios. These concepts allow an understanding of controlling mechanisms and aid in the identification of critical parameters to be collected for field situations. The relative distance of the source to the nearest gas-filled pores of the unsaturated zone is the most critical parameter because diffusive contaminant transport is significantly slower in water-filled pores than in gas-filled pores. Therefore, attenuation factors decrease and characteristic times increase with increasing relative distance of the contaminant dissolved source to the nearest gas diffusion front. Aerobic biodegradation may decrease the attenuation factor by up to three orders of magnitude. Moreover, the occurrence of water table oscillations is of importance. Dynamic processes leading to a retreating water table increase the attenuation factor by two orders of magnitude because of the enhanced gas phase diffusion.

  20. Sensitivity analysis on parameters and processes affecting vapor intrusion risk

    KAUST Repository

    Picone, Sara

    2012-03-30

    A one-dimensional numerical model was developed and used to identify the key processes controlling vapor intrusion risks by means of a sensitivity analysis. The model simulates the fate of a dissolved volatile organic compound present below the ventilated crawl space of a house. In contrast to the vast majority of previous studies, this model accounts for vertical variation of soil water saturation and includes aerobic biodegradation. The attenuation factor (ratio between concentration in the crawl space and source concentration) and the characteristic time to approach maximum concentrations were calculated and compared for a variety of scenarios. These concepts allow an understanding of controlling mechanisms and aid in the identification of critical parameters to be collected for field situations. The relative distance of the source to the nearest gas-filled pores of the unsaturated zone is the most critical parameter because diffusive contaminant transport is significantly slower in water-filled pores than in gas-filled pores. Therefore, attenuation factors decrease and characteristic times increase with increasing relative distance of the contaminant dissolved source to the nearest gas diffusion front. Aerobic biodegradation may decrease the attenuation factor by up to three orders of magnitude. Moreover, the occurrence of water table oscillations is of importance. Dynamic processes leading to a retreating water table increase the attenuation factor by two orders of magnitude because of the enhanced gas phase diffusion. © 2012 SETAC.

  1. Biodegradation in a Partially Saturated Sand Matrix: Compounding Effects of Water Content, Bacterial Spatial Distribution, and Motility

    DEFF Research Database (Denmark)

    Dechesne, Arnaud; Owsianiak, Mikolaj; Bazire, Alexis

    2010-01-01

    colonizing these zones or on pollutant mass transfer to neighboring zones containing degraders. In a model system, we quantified the role exerted by water on mineralization rate in the context of a heterogeneously distributed degradation potential. Alginate beads colonized by Pseudomonas putida KT2440 were......Bacterial pesticide degraders are generally heterogeneously distributed in soils, leaving soil volumes devoid of degradation potential. This is expected to have an impact on degradation rates because the degradation of pollutant molecules in such zones will be contingent either on degraders......, partially relieving the diffusion limitation. Dry conditions, however, sustained low mineralization rates through the combined effects of low pollutant diffusivity and limited degrader dispersal....

  2. Ostrich-like strategies in sahelian sands ? : land and water grabbing in the Office du Niger, Mali

    OpenAIRE

    Thomas Hertzog; Amandine Adamczewski; François Molle; Jean-Christophe Poussin; Jean-Yves Jamin

    2012-01-01

    In recent years, large-scale agricultural investment projects have increased in sub-Saharan Africa as a result of the growing appetites of local and international investors for land resources. Research has so far mainly focused on land issues, but the water implications of these land deals are starting to surface. Taking the Office du Niger (ON), in Mali, as a case study, we show that while around 100,000 ha is currently being cultivated, mostly by smallholders, a total of 600,000 ha of land ...

  3. Adsorption of dyes on Sahara desert sand.

    Science.gov (United States)

    Varlikli, Canan; Bekiari, Vlasoula; Kus, Mahmut; Boduroglu, Numan; Oner, Ilker; Lianos, Panagiotis; Lyberatos, Gerasimos; Icli, Siddik

    2009-10-15

    Sahara desert sand (SaDeS) was employed as a mineral sorbent for retaining organic dyes from aqueous solutions. Natural sand has demonstrated a strong affinity for organic dyes but significantly lost its adsorption capacity when it was washed with water. Therefore, characterization of both natural and water washed sand was performed by XRD, BET, SEM and FTIR techniques. It was found that water-soluble kyanite, which is detected in natural sand, is the dominant factor affecting adsorbance of cationic dyes. The sand adsorbs over 75% of cationic dyes but less than 21% for anionic ones. Among the dyes studied, Methylene Blue (MB) demonstrated the strongest affinity for Sahara desert sand (Q(e)=11.98 mg/g, for initial dye solution concentration 3.5 x 10(-5)mol/L). The effects of initial dye concentration, the amount of the adsorbent, the temperature and the pH of the solution on adsorption capacity were tested by using Methylene Blue as model dye. Pseudo-first-order, pseudo-second-order and intraparticle diffusion models were applied. It was concluded that adsorption of Methylene Blue on Sahara desert sand followed pseudo-second order kinetics. Gibbs free energy, enthalpy change and entropy change were calculated and found -6411 J/mol, -30360 J/mol and -76.58 J/mol K, respectively. These values indicate that the adsorption is an exothermic process and has a spontaneous nature at low temperatures.

  4. Laboratory and field tests on photo-electric probes and ultrasonic Doppler flow switch for remote control of turbidity and flowrate of a water-sand mixture flow

    Science.gov (United States)

    Pellegrini, M.; Saccani, C.

    2017-08-01

    The paper describes the experimental apparatus and field tests carried on to remotely control through non-invasive and non-intrusive instruments turbidity and flowrate of a water-sand mixture flow conveyed by a pipeline. The mixture flow was produced by an innovative plant for seabed management. The turbidity was monitored by thru-beam infra-red photo-electric sensors, while flowrate was monitored by an ultrasonic Doppler flow switch. In a first phase, a couple of photo-electric sensors and a mechanical flow switch were preliminary tested in laboratory to verify installations concerns and measurement repeatability and precision. After preliminary test completion, photo-electric sensors and mechanical flow switch were installed in the real scale plant. Since the mechanical flow switch did not reach high reliability, an ultrasonic Doppler flow switch was identified and tested as alternative. Then, two couple of photo-electric sensors and ultrasonic Doppler flow switch were installed and tested on two pipelines of the plant. Turbidity and minimum flow signals produced by the instruments were integrated in the PLC logic for the automatic management of the plant. The paper also shows how ultrasonic Doppler flow switch measurement repeatability was negatively affected by the presence of the other ultrasonic Doppler flow switch working in a close pipeline and installed inside a steel casing.

  5. Benthic processes affecting contaminant transport in Upper Klamath Lake, Oregon

    Science.gov (United States)

    Kuwabara, James S.; Topping, Brent R.; Carter, James L.; Carlson, Rick A; Parchaso, Francis; Fend, Steven V.; Stauffer-Olsen, Natalie; Manning, Andrew J.; Land, Jennie M.

    2016-09-30

    Executive SummaryMultiple sampling trips during calendar years 2013 through 2015 were coordinated to provide measurements of interdependent benthic processes that potentially affect contaminant transport in Upper Klamath Lake (UKL), Oregon. The measurements were motivated by recognition that such internal processes (for example, solute benthic flux, bioturbation and solute efflux by benthic invertebrates, and physical groundwater-surface water interactions) were not integrated into existing management models for UKL. Up until 2013, all of the benthic-flux studies generally had been limited spatially to a number of sites in the northern part of UKL and limited temporally to 2–3 samplings per year. All of the benthic invertebrate studies also had been limited to the northern part of the lake; however, intensive temporal (weekly) studies had previously been completed independent of benthic-flux studies. Therefore, knowledge of both the spatial and temporal variability in benthic flux and benthic invertebrate distributions for the entire lake was lacking. To address these limitations, we completed a lakewide spatial study during 2013 and a coordinated temporal study with weekly sampling of benthic flux and benthic invertebrates during 2014. Field design of the spatially focused study in 2013 involved 21 sites sampled three times as the summer cyanobacterial bloom developed (that is, May 23, June 13, and July 3, 2013). Results of the 27-week, temporally focused study of one site in 2014 were summarized and partitioned into three periods (referred to herein as pre-bloom, bloom and post-bloom periods), each period involving 9 weeks of profiler deployments, water column and benthic sampling. Partitioning of the pre-bloom, bloom, and post-bloom periods were based on water-column chlorophyll concentrations and involved the following date intervals, respectively: April 15 through June 10, June 17 through August 13, and August 20 through October 16, 2014. To examine

  6. CO2-water-mineral reactions during CO2 leakage into glauconitic sands: geochemical and isotopic monitoring of batch experiments

    Science.gov (United States)

    Humez, P.; Lions, J.; Lagneau, V.; Negrel, Ph.

    2012-04-01

    The assessment of environmental impacts of carbon dioxide geological storage requires the investigation of the potential CO2 leakages into fresh groundwater reserves. The Albian aquifer of the Paris Basin was chosen as a case of study because i) the Paris Basin contains deep saline Jurassic and Triassic aquifers identified as targets by the French national program of CO2 geological storage and ii) the Albian aquifer is a deep freshwater resource of strategic national importance, above the Jurassic and Triassic formations. An experimental and a geochemical modelling approach were carried out in order to better understand the rock-water-CO2 interactions with two main objectives: to assess the evolution of the chemistry of the formation water and of the mineralogy of the solid phase during the interaction and to design a monitoring program for freshwater resources. The main focus is to select and develop suitable indirect indicators of the presence of CO2 in the aquifer. We present here the experimental results, which combines both major and trace elements and isotopic tools, some of them new in the CCS field. Batch reactors with a liquid/solid ratio of 10 made of appropriate materials (PTFE, stainless steel) were equipped with simultaneous controls on several parameters (pH measurement, gas phase composition, pressure, tightness…) after CO2 injection (PCO2= 2 bar; room temperature). Ten reactors were run simultaneously, over pre-determined durations of CO2-water-rock interaction (1, 7, 15 and 30 days). During the batch experiment, we observed major changes in several chemical parameters due to the CO2 injection. A sharp drop in pH from 6.6 to 4.9 was noticeable, immediately after the injection, due to CO2 dissolution in the water phase. Alkalinity varies from 1.3 mmol.L-1 in the initial water to 2.0 mmol.L-1 at the end of the 1-month experiment. Four types of ion behaviors are observed: (1) calcium, silicon and magnesium concentrations increase during the 1-month

  7. The extraction of bitumen from western tar sands. Annual report

    Energy Technology Data Exchange (ETDEWEB)

    Oblad, A.G.; Bunger, J.W.; Deo, M.D.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1990-07-01

    Topics discussed include: characterization of bitumen impregnated sandstone, water based tar sand separation technology, electrophoretic characterization of bitumen and fine mineral particles, bitumen and tar sand slurry viscosity, the hot water digestion-flotation process, electric field use on breaking water-in-oil emulsions, upgrading of bitumens and bitumen-derived liquids, solvent extraction.

  8. The extraction of bitumen from western tar sands

    Energy Technology Data Exchange (ETDEWEB)

    Oblad, A.G.; Bunger, J.W.; Deo, M.D.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1990-07-01

    Topics discussed include: characterization of bitumen impregnated sandstone, water based tar sand separation technology, electrophoretic characterization of bitumen and fine mineral particles, bitumen and tar sand slurry viscosity, the hot water digestion-flotation process, electric field use on breaking water-in-oil emulsions, upgrading of bitumens and bitumen-derived liquids, solvent extraction.

  9. Benthic processes affecting contaminant transport in Upper Klamath Lake, Oregon

    Science.gov (United States)

    Kuwabara, James S.; Topping, Brent R.; Carter, James L.; Carlson, Rick A; Parchaso, Francis; Fend, Steven V.; Stauffer-Olsen, Natalie; Manning, Andrew J.; Land, Jennie M.

    2016-09-30

    Executive SummaryMultiple sampling trips during calendar years 2013 through 2015 were coordinated to provide measurements of interdependent benthic processes that potentially affect contaminant transport in Upper Klamath Lake (UKL), Oregon. The measurements were motivated by recognition that such internal processes (for example, solute benthic flux, bioturbation and solute efflux by benthic invertebrates, and physical groundwater-surface water interactions) were not integrated into existing management models for UKL. Up until 2013, all of the benthic-flux studies generally had been limited spatially to a number of sites in the northern part of UKL and limited temporally to 2–3 samplings per year. All of the benthic invertebrate studies also had been limited to the northern part of the lake; however, intensive temporal (weekly) studies had previously been completed independent of benthic-flux studies. Therefore, knowledge of both the spatial and temporal variability in benthic flux and benthic invertebrate distributions for the entire lake was lacking. To address these limitations, we completed a lakewide spatial study during 2013 and a coordinated temporal study with weekly sampling of benthic flux and benthic invertebrates during 2014. Field design of the spatially focused study in 2013 involved 21 sites sampled three times as the summer cyanobacterial bloom developed (that is, May 23, June 13, and July 3, 2013). Results of the 27-week, temporally focused study of one site in 2014 were summarized and partitioned into three periods (referred to herein as pre-bloom, bloom and post-bloom periods), each period involving 9 weeks of profiler deployments, water column and benthic sampling. Partitioning of the pre-bloom, bloom, and post-bloom periods were based on water-column chlorophyll concentrations and involved the following date intervals, respectively: April 15 through June 10, June 17 through August 13, and August 20 through October 16, 2014. To examine

  10. Aggradation and progradation controlled clinothems and deep-water sand delivery model in the Neogene Lake Pannon, Makó Trough, Pannonian Basin, SE Hungary

    Science.gov (United States)

    Sztanó, Orsolya; Szafián, Péter; Magyar, Imre; Horányi, Anna; Bada, Gábor; Hughes, Daniel W.; Hoyer, Darrel L.; Wallis, Roderick J.

    2013-04-01

    remained negligible in progradational clinothems. Alternations of rising and horizontal shelf margin trajectories indicate that the climate- and subsidence-controlled lacustrine base-level rose continuously, though at varying rates. Descending trajectories were not observed. It means that base-level drops larger in amplitude than the seismic resolution (20-30 m), did not occur during the studied time interval, i.e. at 7-5 Ma ago, approximately corresponding to the Messinian age. As a result, major forced-regressive wedges or lowstand fans did not develop. This is in contrast with former stratigraphic models claiming that several 3rd-order sequences, including the intra-Messinian unconformity supposedly induced by hundred metres large lake-level drop, developed in Lake Pannon with significant volume of lowstand deposits as turbidites. Instead, aggradational and progradational clinothems are interpreted as fourth-order transgressive, early and late highstand systems tracts. These incomplete sequences represent less than 100 kyr time intervals. Due to climate control both on high rate of sediment supply and the water budget of Lake Pannon, conditions were more favourable for deposition of large volumes of well-developed turbidite systems during base-level rise than during stagnation or minor base-level fall. Therefore, sand delivery to the basin centre was at maximum during the early highstand aggradational stage and at minimum during the late highstand progradational stage. The timing and position of sand accumulation in the Makó Trough of Lake Pannon is different from those predicted by "traditional" sequence stratigraphic considerations.

  11. Method of the Moulding Sands Binding Power Assessment in Two-Layer Moulds Systems

    Directory of Open Access Journals (Sweden)

    M. Holtzer

    2014-07-01

    Full Text Available More and more foundry plants applying moulding sands with water-glass or its substitutes for obtaining the high-quality casting surface at the smallest costs, consider the possibility of implementing two-layer moulds, in which e.g. the facing sand is a sand with an organic binder (no-bake type and the backing sand is a sand with inorganic binder. Both kinds of sands must have the same chemical reaction. The most often applied system is the moulding sand on the water-glass or geopolymer bases - as the backing sand and the moulding sand from the group of self-hardening sands with a resol resin - as the facing sand. Investigations were performed for the system: moulding sand with inorganic GEOPOL binder or moulding sand with water glass (as a backing sand and moulding sand, no-bake type, with a resol resin originated from various producers: Rezolit AM, Estrofen, Avenol NB 700 (as a facing sand. The LUZ apparatus, produced by Multiserw Morek, was adapted for investigations. A special partition with cuts was mounted in the attachment for making test specimens for measuring the tensile strength. This partition allowed a simultaneous compaction of two kinds of moulding sands. After 24 hours of hardening the highest values were obtained for the system: Geopol binder - Avenol resin.

  12. Understanding processes affecting mineral deposits in humid environments

    Science.gov (United States)

    Seal, Robert R., II; Ayuso, Robert A.

    2011-01-01

    Recent interdisciplinary studies by the U.S. Geological Survey have resulted in substantial progress toward understanding the influence that climate and hydrology have on the geochemical signatures of mineral deposits and the resulting mine wastes in the eastern United States. Specific areas of focus include the release, transport, and fate of acid, metals, and associated elements from inactive mines in temperate coastal areas and of metals from unmined mineral deposits in tropical to subtropical areas; the influence of climate, geology, and hydrology on remediation options for abandoned mines; and the application of radiogenic isotopes to uniquely apportion source contributions that distinguish natural from mining sources and extent of metal transport. The environmental effects of abandoned mines and unmined mineral deposits result from a complex interaction of a variety of chemical and physical factors. These include the geology of the mineral deposit, the hydrologic setting of the mineral deposit and associated mine wastes, the chemistry of waters interacting with the deposit and associated waste material, the engineering of a mine as it relates to the reactivity of mine wastes, and climate, which affects such factors as temperature and the amounts of precipitation and evapotranspiration; these factors, in turn, influence the environmental behavior of mineral deposits. The role of climate is becoming increasingly important in environmental investigations of mineral deposits because of the growing concerns about climate change.

  13. Sand Layer Water Permeability of Tengger Desert in Zhongwei City,Ningxia Hui Autonomous Region%腾格里沙漠宁夏回族自治区中卫市沙层水分入渗研究

    Institute of Scientific and Technical Information of China (English)

    赵景波; 马延东; 邢闪; 董治宝

    2011-01-01

    In order to explore the water permeability of sand layer and its controlling factors in the Tengger Desert,an infiltration experiment was carried out in the region.The results show that during the first stage before a steady infiltration rate was reached,the moving sand dunes have the highest starting infiltration rate,followed by the half-fixed sand dunes and low-lying-lands in order.After about 6.3~8.8 min,the infiltration rate of sand layers became stable.The saturated infiltration rate of half-fixed sand dune was slightly larger than that of the moving sand dune,while the rate of the low-lying-land remained the smallest.The moving sand dune and the half-fixed sand dune had almost same high infiltration capacities and the low-lying-land has the smallest infiltration capacity.As typical characteristics,the sand layers had high and steady infiltration rates and need only a short period from start to approch steady infiltration rates,owing to the coarse but uniform texture and good pore connectivity.The high infiltration rates provided very good conditions for the transformation from rainfalls to groundwater.For the three infiltration models,the Koctakob formula was the best in describing the water permeability of sand layers,the Horton formula the second,and the general formula the most unfavourable.%为查明腾格里沙丘沙层水分渗透性及其原因,在该地区进行了沙层水分入渗试验。结果表明,在稳定前,流动沙丘入渗率最大,半固定沙丘次之,洼地最小。在达到稳定入渗后,半固定沙丘的入渗率较流动沙丘略大,洼地则最小,它们的平均稳定入渗率分别为16.8,16.2,12.0 mm/min。不同地貌类型的沙层达到稳定入渗的时间在6.3~8.8 min之间。流动沙丘与半固定沙丘水分入渗量基本相同,入渗量均较大,洼地入渗量最小。沙层具有入渗率高,达到稳定入渗快和入渗率变化小的突出特点,沙层粒度较粗,组成均一和孔隙连通性好,是其主

  14. Effect in water purification by airlift sand filter in aquaculture system%气提式砂滤器在水产养殖系统中的水质净化效果

    Institute of Scientific and Technical Information of China (English)

    于冬冬; 倪琦; 庄保陆; 张宇雷; 单建军; 管崇武; 张成林; 吴凡

    2014-01-01

    Traditional pressure sand filter after long time working intercepts large amounts of solid particles and leads to difficult backwash. In order to solve these problems, this study developed an airlift sand filter that can backwash itself while operating by optimizing a traditional filter. The airlift sand filter itself had filtration, separation, flotation, and self-cleaning functions, and could replace the traditional sand filters such as filter cell without valve, mechanical air flotation and other physical filtration device in aquaculture workshop. In the airlift sand filter, quartz sand (in diameter of 1-2 mm) was used as the filter medium, and the aquaculture sewage was flowed upward slowly from the bottom, thus quartz sand could intercept the suspended solids. Meanwhile, the fixed flow gas flowed from the bottom pushed dirt and quartz sand upwards simultaneously. During this process, sand and water were sufficiently contacted with each other. The interaction force between the sand and seawater resulted in production of a large number of bubbles. The suspended solids were then wrapped with the bubbles while quartz sand was cleaned by the sand washing device on the top of the system. The cleaned sand fallen back to the filter system by the gravity, and the suspended solids and waste water flowed out of the outfall. The airlift sand filter has the advantages of simple equipment, convenient operation, backwash without stopping the equipment, smooth and continuous system running, low energy consumption and easy to maintain and repair. The efficiency of the airlift sand filter used for marine recirculating aquaculture systems of the suspended solids (SS) and chemical oxygen demand (COD) was tested. Results showed that removal efficiency of SS and COD by this filter was 41.31%and 34.04%, respectively. Before the filtration, the number of large particles suspended solids (60 μm or higher) was 11.1%, its mass fraction was 71.77% and its mass concentration was 93.53 mg

  15. Laboratory evaluation of selected tar sand asphalts

    Energy Technology Data Exchange (ETDEWEB)

    Button, J.W.; Epps, J.A.; Gallaway, B.M.

    1980-12-01

    Three tar sand asphalts of similar grades prepared from one syncrude by three different refining methods were characterized by tests commonly used to specify paving asphalts together with certain special tests. Asphalt-aggregate mixtures were prepared using these asphalts and tested in the laboratory to determine strength stiffness stability, tensile properties, temperature effects and water susceptibility. Comparison of the tar sand asphalt properties to conventional petroleum asphalt properties reveal no striking differences.

  16. Effects of advanced oxidation on green sand properties via iron casting into green sand molds.

    Science.gov (United States)

    Wang, Yujue; Cannon, Fred S; Voigt, Robert C; Komarneni, Sridhar; Furness, J C

    2006-05-01

    The effects of advanced oxidation (AO) processing on the properties of green sand were studied via pouring cast iron into green sand molds. Upon cooling, the green sand molds were autopsied at various distances from the metal-sand interface. Autopsy green sand samples collected from a mold that incorporated AO water were characterized and compared to controlled samples collected from a similar autopsied mold made with conventional tap water (TAP). It was found that the AO processing removed a coating of coal pyrolysis products from the clay surface that typically accumulated on the clay surface. As a result, the AO-conditioned green sand retained 10-15% more active clay as measured bythe standard ultrasonic methylene blue titration than did the TAP-conditioned green sand. The AO processing also nearly doubled the generation of activated carbon from the normalized amount of coal composition of the green sand during the casting process. The AO-enhanced activated carbon generation and the AO-incurred clay surface cleaning provided the AO-conditioned green sand with higher normalized pore volume, and thus higher normalized m-xylene adsorption capacity, i.e., relative to before-metal-pouring conditions. Furthermore, mathematical analysis indicated that the AO-conditioned green sand better retained its important properties after pouring than did the TAP-conditioned green sand. Effectively, this meant after metal pouring, the AO-conditioned sample offered about the same net properties as the TAP-conditioned sample, even though the AO-conditioned sample contained less clay and coal before metal pouring. These results conformed to the full-scale foundry empirical finding that when AO is used, foundries need less makeup clay and coal addition through each casting cycle, and they release less air emissions.

  17. Technetium, Iodine, and Chromium Adsorption/Desorption Kd Values for Vadose Zone Pore Water, ILAW Glass, and Cast Stone Leachates Contacting an IDF Sand Sequence

    Energy Technology Data Exchange (ETDEWEB)

    Last, George V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Snyder, Michelle M.V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Um, Wooyong [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stephenson, John R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Leavy, Ian I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Strickland, Christopher E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bacon, Diana H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Qafoku, Nikolla [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Serne, R. Jeffrey [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-11-01

    Performance and risk assessments of immobilized low-activity waste (ILAW) at the Integrated Disposal Facility (IDF) have shown that risks to groundwater are quite sensitive to adsorption-desorption interactions occurring in the near- and far-field environment. These interactions between the underlying sediments and the contaminants present in the leachates that descend from the buried glass, secondary waste grouts, and potentially Cast Stone low-activity waste packages have been represented in these assessments using the contaminant distribution coefficient (Kd) construct. Some contaminants (99Tc, 129I, and Cr) present in significant quantities in these wastes have low Kd values and tend to drive risk to public health and the environment. Relatively small changes in the Kd value can cause relatively large changes in the retardation factor. Thus, even relatively small uncertainty in the Kd value can result in a relatively large uncertainty in the risk determined through performance assessment modeling. The purpose of this study is to further reduce the uncertainty in Kd values for 99Tc, iodine (iodide and iodate), and Cr (chromate; CrO42-) by conducting systematic adsorption-desorption experiments using actual sand-dominated Hanford formation sediments from beneath the IDF and solutions that closely mimic Hanford vadose zone pore water and leachates from Cast Stone and ILAW glass waste forms. Twenty-four batch and 21 flow-through column experiments were conducted, yielding 261 Kd measurements for these key contaminants, and contributing to our understanding for predicting transport from wastes disposed to the IDF. While the batch Kd methodology is not well-suited for measuring Kd values for non-sorbing species (as noted by the U.S. Environmental Protection Agency), the batch Kd results presented here are not wholly inconsistent with the column Kd results, and could be used for sensitivity purposes. Results from the column experiments are consistent with the best

  18. Influence green sand system by core sand additions

    Directory of Open Access Journals (Sweden)

    N. Špirutová

    2012-01-01

    Full Text Available Today, about two thirds of iron alloys casting (especially for graphitizing alloys of iron are produced into green sand systems with usually organically bonded cores. Separation of core sands from the green sand mixture is very difficult, after pouring. The core sand concentration increase due to circulation of green sand mixture in a closed circulation system. Furthermore in some foundries, core sands have been adding to green sand systems as a replacement for new sands. The goal of this contribution is: “How the green sand systems are influenced by core sands?”This effect is considered by determination of selected technological properties and degree of green sand system re-bonding. From the studies, which have been published yet, there is not consistent opinion on influence of core sand dilution on green sand system properties. In order to simulation of the effect of core sands on the technological properties of green sands, there were applied the most common used technologies of cores production, which are based on bonding with phenolic resin. Core sand concentration added to green sand system, was up to 50 %. Influence of core sand dilution on basic properties of green sand systems was determined by evaluation of basic industrial properties: moisture, green compression strength and splitting strength, wet tensile strength, mixture stability against staling and physical-chemistry properties (pH, conductivity, and loss of ignition. Ratio of active betonite by Methylene blue test was also determined.

  19. 水基提取技术用于油砂分离的研究进展%Research progress in water-based bitumen extraction from oil sands

    Institute of Scientific and Technical Information of China (English)

    任嗣利

    2011-01-01

    As an unconventional oil resource, oil sands and its processing technology has attracted much attention in China in recent years. Water-based extraction processes are the most important method to recover bitumen from oil sands. Two key steps are involved in this process: bitumen liberation from the sand grains and bitumen aeration followed by flotation to form a bitumen-rich froth. Any factor that causes poor liberation or poor aeration will result in a poor bitumen recovery. With the use of the advanced analytical instrumentations, such as the atomic force microscope (AFM), the understanding for the bitumen extraction from oil sands is extended from the macroscopic scale to the molecular level. It is found that the wettability of solids and water chemistry play significant roles in the processability of oil sands. Mechanisms related to the bitumen extraction processes are discussed in detail. The procedures of recovering bitumen from oil sands in industry are also briefly described.%油砂作为一种重要的非常规油气资源,其分离技术的研究近些年来引起了国内科研工作人员的重视.介绍了目前世界上最重要的油砂分离技术——水基提取技术的基本原理及影响油砂分离的重要影响因素,阐述了油砂结构、特性与水基提取分离的重要关系及分离条件对沥青回收率的重要影响作用,同时探讨了原子力显微镜用于油砂水基分离过程中相关微观机理研究的重要应用,最后对水基提取技术用于油砂工业生产的流程进行了简单介绍.

  20. Sands cykliske styrke

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo

    1992-01-01

    Sands cykliske styrke kan beskrives ved Cyclic Liquefaction, Mobilisering, Stabilization og Instant Stabilization. I artiklen beskrives hvorfor Stabilization og Instant Stabilization ikke observeres, når sands udrænede styrke undersøges i triaxial celler, der anvender prøver med dobbelt prøvehøjde....

  1. Baskarp Sand No. 15

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Bødker, Lars Bødker

    The Soil Mechanics Laboratory has started performing tests with a new sand, Baskarp No 15. Baskarp No 15 is a graded sand from Sweden. The shapes of the largest grains are round, while the small grains have sharp edges. The main part of of Baskarp No 15 is quarts, but it also contains feldspar...

  2. North American Oil Sands: History of Development, Prospects for the Future

    Science.gov (United States)

    2008-01-17

    mixture of sand, bitumen (a heavy crude that does not flow naturally), and water, can be mined or the oil can be extracted in-situ using thermal recovery...quartz sand, bitumen , and water that can either be mined or extracted in-situ5 using thermal recovery techniques. Typically, oil sands contain about...different technology for bitumen extraction than that used for Alberta’s water-wetted deposits. Oil sands are characterized as having a wet interface

  3. Evaluate of head loss, sediment value and copper removal in sand media (rapid sand filter

    Directory of Open Access Journals (Sweden)

    Daneshi Navab

    2014-06-01

    Full Text Available Along with the technology development and increasing consumption of water resources, we are experiencing low qualities in the mentioned resources. Copper brings about serious environment al pollution, threatening human health and ecosystem. This metal found variously in water resources and industrial activities. Therefore, it needs to treat the water resources from these excessive amounts. Different methods have used for this reason but the most used method during recent years has been the absorption by economic absorbers such as sand. Rapid sand filters usually used in water and wastewater treatment plants for water clarification. In this research, a single layer gravity rapid sand filter has used to reduce different concentrations of copper. sediment value and head loss arising in filter media is simulated by using combination of Carman-Kozeny, Rose and Gregory models in different discharges of rapid sand filter. Results have shown that with increasing in discharge and decreasing in input copper concentration, arriving time to given head loss, is increasing. In addition, results demonstrated that with increasing in copper concentration in influent, removal efficiency is decreasing somewhat. Results of this research can applied in an appropriate design of rapid sand filter to copper removal, a prediction of rapid sand filter ability to copper removal and an estimation of arising head loss during filter work thus evaluating of time interval backwash. DOI: http://dx.doi.org/10.3126/ije.v3i2.10641 International Journal of the Environment Vol.3(2 2014: 276-286

  4. Bioaugmentation of flow-through sand filters

    DEFF Research Database (Denmark)

    Samuelsen, Elin Djurhuus

    Global applications of pesticides in agricultural production have led to the detection of trace amounts of pesticides in groundwater resources in levels exceeding the EU threshold limit for drinking water of 0.1 µg L-1. Pesticide-polluted groundwater may be remediated by inoculating waterworks sand...... for degradation performances in flow-through sand columns, with the aim of identifying a suitable inoculant strain for future environmental applications. Another aim was to identify a suitable genetic marker to monitor phenoxy acid degradation in strain Sphingobium sp. PM2. We were not able to link motility...... and biofilm formation to the strains´ ability to adhere to sand. Nevertheless, a correlation was found between cell surface hydrophobicity and adhesion and overall degradation performances in flow-through sand columns. We identified S phingobium sp. PM2 as a promising inoculant strain, displaying efficient...

  5. The extraction of bitumen from western tar sands. Annual report, July 1990--July 1991

    Energy Technology Data Exchange (ETDEWEB)

    Oblad, A.G.; Bunger, J.W.; Deo, M.D.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1992-04-01

    Contents of this report include the following: executive summary; characterization of the native bitumen from the Whiterocks oil sand deposit; influence of carboxylic acid content on bitumen viscosity; water based oil sand separation technology; extraction of bitumen from western oil sands by an energy-efficient thermal method; large- diameter fluidized bed reactor studies; rotary kiln pyrolysis of oil sand; catalytic upgrading of bitumen and bitumen derived liquids; ebullieted bed hydrotreating and hydrocracking; super critical fluid extraction; bitumen upgrading; 232 references; Appendix A--Whiterocks tar sand deposit bibliography; Appendix B--Asphalt Ridge tar sand deposit bibliography; and Appendix C--University of Utah tar sands bibliography.

  6. Simulating and understanding sand wave variation: A case study of the Golden Gate sand waves

    Science.gov (United States)

    Sterlini, F.; Hulscher, S.J.M.H.; Hanes, D.M.

    2009-01-01

    In this paper we present a detailed comparison between measured features of the Golden Gate sand wave field and the results of a nonlinear sand wave model. Because the Golden Gate sand waves exhibit large variation in their characteristics and in their environmental physics, this area gives us the opportunity to study sand wave variation between locations, within one well-measured, large area. The nonlinear model used in this paper is presently the only tool that provides information on the nonlinear evolution of large-amplitude sand waves. The model is used to increase our understanding of the coupling between the variability in environmental conditions and the sand wave characteristics. Results show that the model is able to describe the variation in the Golden Gate sand waves well when both the local oscillating tidal current and the residual current are taken into account. Current and water depth seem to be the most important factors influencing sand wave characteristics. The simulation results give further confidence in the underlying model hypothesis and assumptions. Copyright 2009 by the American Geophysical Union.

  7. 含水松散层下厚煤层采掘溃砂危险性分析%Sand Inrush Hazard Analysis of Thick Coal Seam Mining Under Water-bearing Unconsolidated Strata

    Institute of Scientific and Technical Information of China (English)

    符辉; 蔡先锋; 冯锐敏; 于辉

    2012-01-01

    For the projects difficulties of sand inrush of thick coal seam mining under water-bearing unconsolidated strata,the paper carries out scientific analysis of hydro-geological conditions,including the lithology,thickness,and water yield property of water-bearing unconsolidated strata,reasonable size of leaving safety coal and rock pillars in thick seam slicing mining is discussed and the corresponding mining methods are decided.On the basis,the heights of caving zone and water conducted zone were predicted,mining method was decided.Based on the powerful data processing capabilities of GIS,the risk of sand inrush caused by multiple factors are analyzed quantitatively,and sand inrush risk zoning map was also drew eventually.%针对含水松散层下厚煤层采掘溃砂工程难点,对含水松散层的岩性、厚度和富水性等水文地质条件进行研究,探讨了厚煤层分层开采留设安全煤岩柱合理尺寸,并确定了相应的开采方法;预计了(垮落带和导水裂隙带)"两带"高度,基于GIS的强大数据处理功能,对多因素引起的采动溃砂危险性进行了量化评价,分析得出了分层开采条件下顶板溃砂危险性分区图。

  8. Removals of cryptosporidium parvum oocysts and cryptosporidium-sized polystyrene microspheres from swimming pool water by diatomaceous earth filtration and perlite-sand filtration.

    Science.gov (United States)

    Lu, Ping; Amburgey, James E; Hill, Vincent R; Murphy, Jennifer L; Schneeberger, Chandra L; Arrowood, Michael J; Yuan, Tao

    2017-06-01

    Removal of Cryptosporidium-sized microspheres and Cryptosporidium parvum oocysts from swimming pools was investigated using diatomaceous earth (DE) precoat filtration and perlite-sand filtration. In pilot-scale experiments, microsphere removals of up to 2 log were obtained with 0.7 kg·DE/m(2) at a filtration rate of 5 m/h. A slightly higher microsphere removal (2.3 log) was obtained for these DE-precoated filters when the filtration rate was 3.6 m/h. Additionally, pilot-scale perlite-sand filters achieved greater than 2 log removal when at least 0.37 kg/m(2) of perlite was used compared to 0.1-0.4 log removal without perlite both at a surface loading rate of 37 m/h. Full-scale testing achieved 2.7 log of microspheres and oocysts removal when 0.7 kg·DE/m(2) was used at 3.6 m/h. Removals were significantly decreased by a 15-minute interruption of the flow (without any mechanical agitation) to the DE filter in pilot-scale studies, which was not observed in full-scale filters. Microsphere removals were 2.7 log by perlite-sand filtration in a full-scale swimming pool filter operated at 34 m/h with 0.5 kg/m(2) of perlite. The results demonstrate that either a DE precoat filter or a perlite-sand filter can improve the efficiency of removal of microspheres and oocysts from swimming pools over a standard sand filter under the conditions studied.

  9. Statistical analysis of water traffic accident and safety management for sand ship%砂石船舶水上交通事故统计分析及安全管理

    Institute of Scientific and Technical Information of China (English)

    李文华; 马晓雪; 马来好; 陈海泉; 张银东; 乔卫亮

    2014-01-01

    对某水域2008-2012年上半年砂石船舶水上交通事故进行统计分析,探索砂石船舶水上交通事故的发生规律。结合对砂石船舶营运系统中船员、船舶、环境、管理和砂石五个方面的剖析,有针对性地提出相应的安全管理对策,为相关责任部门制订砂石船舶水上交通安全管理对策提供参考。%Based on the statistical analysis of the sand ship traffic accidents in some water areas from 2008 to the first half year of 2012 , the occurrence of traffic accidents for sand ship was explored , and combining with statistical analysis on fol-lowing five aspects , including crew , ship, environment , man-agement and sand which were in the operation of the ship sys-tems, the countermeasures for safety management were pro-posed,which can provide reference for the relevant responsible departments .

  10. EXPERIMENTAL STUDY AND NUMERICAL SIMULATION OF FLUORIDE IN SAND

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong-mei; SU Bao-yu

    2006-01-01

    The transport and transformation of fluoride in sand were studied by using soil tank test under the condition of saturated water in this article. Based on the analysis of the laboratory experiments, the rules of fluorine transportation and transformation were simulated in sand by solving the advection-diffusion equation. Through comparison between computed results and observed data , it is shown that the established model and determined parameters could be used to simulate the fluoride transport in sand.

  11. Sand and Gravel Deposits

    Data.gov (United States)

    Vermont Center for Geographic Information — This dataset is a statewide polygon coverage of sand, gravel, and stone resources. This database includes the best data available from the VT Agency of Natural...

  12. Sand and Gravel Operations

    Data.gov (United States)

    Department of Homeland Security — This map layer includes sand and gravel operations in the United States. These data were obtained from information reported voluntarily to the USGS by the aggregate...

  13. Vestled - Hvide Sande

    DEFF Research Database (Denmark)

    Juel-Christiansen, Carsten; Hesselbjerg, Marianne; Schønherr, Torben

    2009-01-01

    Værket Vestled i Hvide Sande præsenteret i sammenhæng af 1000 nutidige landskabsarkitektoniske arbejder fra hele verden, hvor hvert værk vises på én side......Værket Vestled i Hvide Sande præsenteret i sammenhæng af 1000 nutidige landskabsarkitektoniske arbejder fra hele verden, hvor hvert værk vises på én side...

  14. 炭砂复合滤池处理微污染水源水的研究%GAC/Sand Filter for Treatment of Micro-polluted Source Water

    Institute of Scientific and Technical Information of China (English)

    吴强; 陆少鸣

    2012-01-01

    The pilot-scale and full-scale tests on treatment of IV to inferior V grade surface water by GAC/sand filter were conducted, and the GAC/sand filter was compared with the conventional process. The results showed that there was no difference in turbidity removal between the GAC enhanced filtration process and the conventional filtration process, and the final effluent turbidity of the two processes both met the requirements of Standards for Drinking Water Quality ( GB 5749 - 2006 ) . The GAC enhanced filtration process was superior to the conventional filtration process in removal of ammonia nitrogen. The nitrite nitrogen accumulation phenomenon occurred in the GAC enhanced filtration process, but its nitrification effect was better than the ordinary sand filter. The effluent CODMn from the GAC enhanced filtration process met the requirements of Standards for Drinking Water Quality ( GB 5749 - 2006) . The GAC/sand filter had obvious nitrification, and the dissolved oxygen consumption in the filtered water was relatively large, so aeration needed to be conducted to speed up the nitrification process.%分别进行了炭砂复合滤池处理Ⅳ类~劣V类地表水的中试和生产性试验,并与常规过滤工艺进行对比.中试及生产性试验结果表明,GAC强化过滤工艺在去除浊度方面与常规过滤工艺相差不大,两种工艺的最终出水浊度都可达到《生活饮用水卫生标准》( GB 5749-2006)的要求;GAC强化过滤工艺在去除氨氮方面优于常规过滤工艺;GAC强化过滤工艺存在亚硝酸盐氮积累现象,但其硝化效果较普通砂滤池好;GAC强化过滤工艺的出水CODMn值基本能达到《生活饮用水卫生标准》( GB 5749-2006)的规定;炭砂复合滤池的硝化作用比较明显,对溶解氧的消耗量比较大,要加速硝化过程则需进行曝气充氧.

  15. MECHANICAL REGENERATION OF SAND WASTE

    Directory of Open Access Journals (Sweden)

    D. I. Gnir

    2005-01-01

    Full Text Available The experimental activation of the sand regenerator of the firm SINTO is carried out at ОАО “MZOO". It is shown that sand grains are cleared from films of binding agents, that allows to use the treated sand for preparation of agglutinant and core sands.

  16. Comprehensive Construction Techniques for a Tunnel in Water-soaked Gravel and Sand%砂卵石地层出水隧道施工综合技术

    Institute of Scientific and Technical Information of China (English)

    哈吉章; 黄威望; 邵大鹏

    2011-01-01

    文章阐述了甘谷墩隧道砂卵石地质出水段采用的增加初喷混凝土厚度、减小钢架间距、拱脚处加设锁脚锚管及全断面注水泥-水玻璃双液浆等加强初期支护的施工措施;通过对开挖支护效果的分析,总结了砂卵石地层出水段施工综合技术.%Parameters of primary support was improved by increaing initial shotcret thickness, reducing steel frame intervals,setting locking anchor pipes at arch abutments and full-face composite grouting with cement and water glass for the water-soaked gravel and sand section in Gangudun tunnel. Construction techniques of the tunnel in water-soaked gravel and sand is summarized after analyzing the effect of support.

  17. 产水气井井筒携砂机制及携砂能力评价试验与应用%Experimental study on mechanism and capability of sand-carrying in water-producing gas wells and its application

    Institute of Scientific and Technical Information of China (English)

    董长银; 陈新安; 阿雪庆; 陈宇; 康瑞鑫; 冯胜利

    2014-01-01

    对垂直井筒不同水气比和含砂体积分数下的气水砂三相流动机制及气水携砂能力进行系统的试验研究。通过试验得到单相气体携砂和气水携砂临界流速与砂粒径的定量关系和规律。根据试验数据揭示的气液携砂机制,建立不产水和产水气井的临界携砂流速模型,用于预测给定生产条件下的携砂条件和携砂能力,并提出考虑井筒携砂的新型气井综合协调曲线用于实际气井工况分析和制度调整。结果表明:一旦气井见水,气井携砂能力将比不产水条件下严重降低,气体流速和水气比是控制携砂动态的主要因素;随着水气比从零开始升高,流型依次为无携砂现象的泥状流、具有携砂能力的环雾流、段塞流,以及其他相同水气比条件下的气水两相流型;气液两相流要达到携砂条件,气体流速必须达到携液流速,并且液相流速要达到基本的单相液体携砂条件。%The gas-liquid-solid multi-phase flow in vertical wells was experimentally simulated to study the mechanism and capability of sand-carrying for gas wells with water production, in which the effects of gas and water flow rate, water-gas ratio (WGR) and sand volume fraction were investigated. Based on experimental results, the critical gas flow rate for sand-carry-ing and the relationship between the size of sands and gas and water flow rate were obtained. A sand-carrying evaluation mod-el for gas well with and without water production was developed. The model can be used to predict the critical gas flow rate for sand-carrying with various sand sizes and the maximum sand rate that can be carried by gas at a certain flow rate. A new integrated coordination chart was figured out for the evaluation of sand-carrying capability in gas wells with water and sand production. The results show that, once the well starts to produce water, its sand-carrying capability will be reduced com

  18. Effect of Lithology on the Efficiency of the Hot Water-Based Extraction for Oil Sand Bitumen:A Case Study on Oil Sands from Houba,Sichuan and Tumuji,Inner Mongolia%岩性因素对油砂热碱水分离效率的影响--以四川厚坝及内蒙古图牧吉油砂为例

    Institute of Scientific and Technical Information of China (English)

    何嘉健; 耿安松; 吴亮亮

    2015-01-01

    油砂是一种重要的非常规石油资源,目前较为常用的沥青回收方式是热碱水分离法。本文运用热碱水分离法处理了四川厚坝与内蒙古图牧吉两地的油砂样品,并对上述两地的油砂样品进行了镜下薄片观察、XRD 分析以及比表面积和总孔容测定,对比分析了两者的岩性特征和油砂热碱水分离实验的数据,结果表明,油砂中黏土矿物的含量、油砂岩的胶结程度及胶结方式、油砂的砂颗粒粒径、油砂层遭受风化作用的程度等因素都会影响油砂沥青热碱水分离的效率,在设计油砂开采工艺流程时,应该综合考虑这些因素。%Oil sand is a kind of unconventional fuel resource.The hot water-based extraction is the most common way to recover bitumen from oil sands.In this research,the oil sand samples from Houba,Sichuan,and Tumuji,Inner Mongo-lia,were conducted using the hot water-based extraction method.Microscope observation,XDR analyses,specific surface area and pore volume of oil sands were applied to qualify the lithology of different samples.The bitumen recoveries of the hot water-based extraction were correlated to the lithologic characters of the oil sands.The result shows that factors,such as contents of clay minerals,cementation manner and degree,grain sizes of minerals,and the degree of weathering,may affect the bitumen recovery efficiency from oil sands using the hot water-based extraction.These factors should be taken in-to account in process design for bitumen recovery from oil sands.

  19. Study on curtain grouting sand-consolidating and water-shutoff technique used in overall Xiushan tunnel section%秀山隧道全断面帷幕注浆固砂止水技术研究

    Institute of Scientific and Technical Information of China (English)

    陈先智; 韩银利

    2012-01-01

    In light of characteristics of Xiushan tunnel with complicated hydrological conditions and high surrounding water sources demands, curtain grouting water-shutoff technique is applied which is good for protecting ecological environment of the tunnel top and reducing future trou- ble. As a result, the construction difficulties including high-pressure water gushing in the tunnel and sudden sand are successfully solved.%针对秀山隧道水文地质条件较复杂,周围水资源环境要求高的特点,通过采用有利于保护洞顶生态环境、减少后患的帷幕注浆堵水技术,成功地解决了洞内高压涌水、突砂等施工难题。

  20. A new low-cost method of reclaiming mixed foundry waste sand based on wet-thermal composite reclamation

    Institute of Scientific and Technical Information of China (English)

    Fan Zitian; Liu Fuchu; Long Wei; Li Guona

    2014-01-01

    A lot of mixed clay-resin waste sand from large-scale iron foundries is discharged every day; so mixed waste sand reclamation in low cost and high quality has a great realistic significance. In the study to investigate the possibility of reusing two types of waste foundry sands, resin bonded sand and clay bonded sand which came from a Chinese casting factory, a new low-cost reclamation method of the mixed foundry waste sand based on the wet-thermal composite reclamation was proposed. The waste resin bonded sand was first reclaimed by a thermal method and the waste clay bonded sand was reclaimed by a wet method. Then, hot thermal reclaimed sand and the dehydrated wet reclaimed sand were mixed in certain proportions so that the hot thermal reclaimed sand dried the wet reclaimed sand leaving some water. The thermal reclamation efficiency of the waste resin bonded sand was researched at different heat levels. The optimized wet reclamation process of the waste clay bonded sand was achieved by investigating the effects of wet reclamation times, sand-water ratio and pH value on the reclaimed sand characteristics. The composite reclamation cost also was calculated. The research results showed that the properties of the mixed reclaimed sand can satisfy the application requirements of foundries; in which the temperature of the thermal reclamation waste resin bonded sand needs to be about 800 ºC, the number of cycles of wet reclamation waste clay bonded sand should reach four to five, the optimal sand-water ratio of wet reclamation is around 1:1.5, and the pH value should be adjusted by adding acid. The mass ratio of hot thermal reclaimed sand to dehydrated wet reclaimed sand is about 1:2.5, and the composite reclaimed sand cost is around 100 yuan RMB per ton.

  1. A new low-cost method of reclaiming mixed foundry waste sand based on wet-thermal composite reclamation

    Directory of Open Access Journals (Sweden)

    Fan Zitian

    2014-09-01

    Full Text Available A lot of mixed clay-resin waste sand from large-scale iron foundries is discharged every day; so mixed waste sand reclamation in low cost and high quality has a great realistic significance. In the study to investigate the possibility of reusing two types of waste foundry sands, resin bonded sand and clay bonded sand which came from a Chinese casting factory, a new low-cost reclamation method of the mixed foundry waste sand based on the wet-thermal composite reclamation was proposed. The waste resin bonded sand was first reclaimed by a thermal method and the waste clay bonded sand was reclaimed by a wet method. Then, hot thermal reclaimed sand and the dehydrated wet reclaimed sand were mixed in certain proportions so that the hot thermal reclaimed sand dried the wet reclaimed sand leaving some water. The thermal reclamation efficiency of the waste resin bonded sand was researched at different heat levels. The optimized wet reclamation process of the waste clay bonded sand was achieved by investigating the effects of wet reclamation times, sand-water ratio and pH value on the reclaimed sand characteristics. The composite reclamation cost also was calculated. The research results showed that the properties of the mixed reclaimed sand can satisfy the application requirements of foundries; in which the temperature of the thermal reclamation waste resin bonded sand needs to be about 800 篊, the number of cycles of wet reclamation waste clay bonded sand should reach four to five, the optimal sand-water ratio of wet reclamation is around 1:1.5, and the pH value should be adjusted by adding acid. The mass ratio of hot thermal reclaimed sand to dehydrated wet reclaimed sand is about 1:2.5, and the composite reclaimed sand cost is around 100 yuan RMB per ton.

  2. Permeability Tests on Eastern Scheldt Sand

    DEFF Research Database (Denmark)

    Jakobsen, Kim Parsberg

    The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends on the charact......The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends...... on the characteristics of the soil matrix, the permeability is determined for different void ratios. All tests are performed on reconstituted specimens of Eastern Scheldt Sand. The permeability is determined by use of a falling head apparatus. Finally the test results are briefly summarised and a relationship between...... void ratio and permeability is established....

  3. Efficient modelling of sand wave behaviour [Powerpoint Presentation

    NARCIS (Netherlands)

    Berg, van den Joris; Damme, van Ruud

    2004-01-01

    Sand waves form a pattern of more or less parallel ridges. The wave length is about 300 meters and the height up to 10 meters, which is a considerable amount of the total water depth. Sand waves migrate with speeds of about 10 meters per year. Information on their behaviour is valuable: the larger p

  4. Pathogen removal using saturated sand colums supplemented with hydrochar

    NARCIS (Netherlands)

    Chung, J.W.

    2015-01-01

    This PhD study has evaluated hydrochars derived from biowastes as adsorbents for pathogen removal in water treatment. Pathogen removal experiments were conducted by carrying out breakthrough analysis using a simple sand filtration set-up. Glass columns packed by 10 cm sand bed supplemented with mino

  5. Cleaning oil sands drilling waste in Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Mikic, N.; Nilsen, C.; Markabi, M. [Mi SWACO, Calgary, AB (Canada)

    2008-07-01

    The waste generated from steam assisted gravity drainage (SAGD) wells is brought to the surface and separated by shale shakers. The waste can include drilling fluids and sand contaminated with bitumen. This paper described a new technology developed to treat waste using the addition of hot water and various mixing and separation technologies to reduce the viscosity of the bitumen and separate it from the sand. The bitumen-contaminated drill cuttings were mixed with hot water to form a slurry that was then separated through the G-force created by a hydrocyclone. A secondary separation was then conducted in an elutriation column to remove residual contaminants from the sand. The flow rate of the process was controlled by the fine solids composition of the cuttings, the temperature of the cleaning process, and the performance of the individual components. Laboratory tests conducted to tests the method showed that the sand particles produced using the method were clean enough to be safely disposed in the environment. A pilot study will be conducted to test the sand cleaning technology at a commercial scale. 6 refs., 3 figs.

  6. Water supply and residual debris treatment for natural sand gravel processing system of Zaoshi project%皂市工程天然砂石加工系统供水及废渣处理

    Institute of Scientific and Technical Information of China (English)

    陈雯

    2000-01-01

    皂市水利枢纽工程的天然砂石加工系统位于渫水河左岸的漫滩地上,枯水期河水走右河槽。为了取到河水冲洗骨料,应用渗渠原理,在河漫滩下预埋集水管至左岸泵站的集水间。设两座沉渣池处理废水废渣。每座沉渣池的工作周期为14 d,即进水7 d,压实、脱水3~4 d,挖砂、清洗4~3 d。从设计上较好地解决了废水废渣的处理。对供水工程和废渣处理工艺流程作了详细介绍。%Natural sand gravel aggregate processing system for Zaoshi hydroporject is located on the left bank floodland of Xieshui river which flows along the right channel in dry season. In order to take water from the river to clean aggregate, applying seepage trench method, water collecting pipes are preembedded under the floodland and connected with sump pool of the left bank pump station. 2 sediment pools are set up for the waste water and residual debris disposal. The working period of each sediment pool is 14 days, 7 days for water intaking, 3~4 days for compaction and dewatering, 4~3 days for sand excavation and cleaning. The problem of the waste water and residual debris disposal is well solved in the design.

  7. Cyclic Triaxial Loading of Cohesionless Silty Sand

    DEFF Research Database (Denmark)

    Sabaliauskas, Tomas; Ibsen, Lars Bo

    2015-01-01

    To engineer efficient structures offshore, we need to extend our knowledge of soil response. Cyclic loading and high water pressure encountered offshore greatly influence cohesionless soil performance. Silty sand from Frederikshavn wind turbine farm was tested using single diameter height samples...

  8. Toxic effects of oil sand naphthenic acids on the biomass accumulation of 21 potential phytoplankton remediation candidates.

    Science.gov (United States)

    Woodworth, Adam P J; Frank, Richard A; McConkey, Brendan J; Müller, Kirsten M

    2012-12-01

    The oil sands of northern Alberta, Canada contain an estimated 170 billion barrels of crude oil. Extraction processes produce large amounts of liquid tailings known as oil sand process affected water (OSPW) that are toxic to aquatic organisms. Naphthenic acids (NAs), and their sodium salts, represent a significant contributor to the toxicity of these waters. Due to the recalcitrant nature of these compounds, an effective mode of remediation has yet to be established. This study investigates the suitability of the use of phytoplankton for remediation efforts based on two criteria: the ability of phytoplankton strains to withstand the toxic effects of NAs, and their rate of biomass accumulation. A total of 21 phytoplankton strains were isolated from waters containing NAs, cultured, and maintained under unialgal conditions. These strains were then exposed to NAs in concentrations ranging from 0mg L(-1) to 1000mg L(-1) over a 14 day period. Inhibition of growth was observed at 30mg L(-1) NA (one strain), 100mg L(-1) NA (one strain), 300mg L(-1) NA (six strains), and 1000mg L(-1) NA (six strains). Five strains failed to show any growth inhibition at any test concentration and two strains could not be analysed due to poor growth during the test period. Strains were then ranked based on their suitability for use in remediation efforts.

  9. Faecal indicator bacteria enumeration in beach sand: A comparison study of extraction methods in medium to coarse sands

    Science.gov (United States)

    Boehm, A.B.; Griffith, J.; McGee, C.; Edge, T.A.; Solo-Gabriele, H. M.; Whitman, R.; Cao, Y.; Getrich, M.; Jay, J.A.; Ferguson, D.; Goodwin, K.D.; Lee, C.M.; Madison, M.; Weisberg, S.B.

    2009-01-01

    Aims: The absence of standardized methods for quantifying faecal indicator bacteria (FIB) in sand hinders comparison of results across studies. The purpose of the study was to compare methods for extraction of faecal bacteria from sands and recommend a standardized extraction technique. Methods and Results: Twenty-two methods of extracting enterococci and Escherichia coli from sand were evaluated, including multiple permutations of hand shaking, mechanical shaking, blending, sonication, number of rinses, settling time, eluant-to-sand ratio, eluant composition, prefiltration and type of decantation. Tests were performed on sands from California, Florida and Lake Michigan. Most extraction parameters did not significantly affect bacterial enumeration. anova revealed significant effects of eluant composition and blending; with both sodium metaphosphate buffer and blending producing reduced counts. Conclusions: The simplest extraction method that produced the highest FIB recoveries consisted of 2 min of hand shaking in phosphate-buffered saline or deionized water, a 30-s settling time, one-rinse step and a 10 : 1 eluant volume to sand weight ratio. This result was consistent across the sand compositions tested in this study but could vary for other sand types. Significance and Impact of the Study: Method standardization will improve the understanding of how sands affect surface water quality. ?? 2009 The Society for Applied Microbiology.

  10. Lund Sand No 0

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Jakobsen, Finn Rosendal

    During the last 15 years the Geotechnical Engineering Group (GEG) at Aalborg University has performed triaxial tests with a sand called Lund No 0. Lund No 0 is a graded sand from a gravel pit near Horsens in Denmark. For the classification of the sand the following tests have been performed: Sieve...... test, Grain density, ds, Maximum, emax, and minimum, emin, void ratio. The strength parameters of Lund No 0 are detennined by some drained and undrained triaxial tests in the Danish Triaxial Cell. The Danish Triaxial Cell prescribes smooth pressure heads and specimens with equal height and diameter....... Four series with Id equal to 0.92, 0.87 0.76 and 0.55 have been performed....

  11. UK Frac Sand Resources

    OpenAIRE

    Mitchell, C J

    2015-01-01

    Although still just a glimmer in the gas man’s eye, the prospect of shale hydrocarbon (oil and gas) development in the UK has many companies thinking about the industrial minerals it will require. Chief amongst these is silica sand which is used as a ‘proppant’ in the hydraulic fracturing, or ‘fracking’, of shales to help release the gas. The UK has large resources of sand and sandstone, of which only a small proportion have the necessary technical properties that classify them as ‘silica san...

  12. Formation mechanism and development pattern of aeolian sand landform in Yarlung Zangbo River valley

    Institute of Scientific and Technical Information of China (English)

    李森; 董光荣; 申建友; 杨萍; 刘贤万; 王跃; 靳鹤龄; 王强

    1999-01-01

    Aeolian sand landforms in the Yarlung Zangbo River valley can be divided into 4 classes and 21 types. The river valley has favourable environment conditions for the development of aeolian sand landforms. Simulation of MM4 mid-scale climate model showed that the near-surface flow field and wind vector field during the winter half year in the fiver valley are generally favourable for the aeolian sand deposition and as a whole they also affect the distribution zones and sites of aeolian sand landforms. Sand dunes and sand dune groups in the fiver valley developed mainly in three ways, namely windward retarding deposition, leeward back flow deposition and bend circumfluence deposition. Through alternating positive-reverse processes of sand dune formation under wind actions and sand dune vanishing under water actions, sand dunes developed from primary zone through main-body zone then to vanishing zone where climbing dunes and falling dunes are declining and are even disappearing.

  13. Enhanced characterization of oil sands acid-extractable organics fractions using electrospray ionization-high-resolution mass spectrometry and synchronous fluorescence spectroscopy.

    Science.gov (United States)

    Bauer, Anthony E; Frank, Richard A; Headley, John V; Peru, Kerry M; Hewitt, L Mark; Dixon, D George

    2015-05-01

    The open pit oil sands mining operations north of Fort McMurray, Alberta, Canada, are accumulating tailings waste at a rate approximately equal to 4.9 million m(3) /d. Naphthenic acids are among the most toxic components within tailings to aquatic life, but structural components have largely remained unidentified. In the present study, electrospray ionization high-resolution mass spectrometry (ESI-HRMS) and synchronous fluorescence spectroscopy (SFS) were used to characterize fractions derived from the distillation of an acid-extractable organics (AEO) mixture isolated from oil sands process-affected water (OSPW). Mean molecular weights of each fraction, and their relative proportions to the whole AEO extract, were as follows: fraction 1: 237 Da, 8.3%; fraction 2: 240 Da, 23.8%; fraction 3: 257 Da, 26.7%; fraction 4: 308 Da, 18.9%; fraction 5: 355 Da, 10.0%. With increasing mean molecular weight of the AEO fractions, a concurrent increase occurred in the relative abundance of nitrogen-, sulfur-, and oxygen-containing ions, double-bond equivalents, and degree of aromaticity. Structures present in the higher-molecular-weight fractions (fraction 4 and fraction 5) suggested the presence of heteroatoms, dicarboxyl and dihydroxy groups, and organic acid compounds with the potential to function as estrogens. Because organic acid compositions become dominated by more recalcitrant, higher-molecular-weight acids during natural degradation, these findings are important in the context of oil sands tailings pond water remediation.

  14. Technological test for application of grease hardening water-glass sand%脂硬化水玻璃砂应用工艺试验

    Institute of Scientific and Technical Information of China (English)

    朱建军; 梅志明; 程乾坤; 乔增国

    2012-01-01

    Since the rate of hardening, intensity and other indexes of the grease hardening sodiam silicate sand are sensitive to ambient temperature, the curing agent proportioning needs to be adjusted in time according to the ambient condition of production process. The variation of the curing agent proportioning for grease hardening sodiam silicate sand with pot life, hardening time and tensile strength at 0 ~ 10℃, 11 ~20℃ , 21 ~30℃ and 30 ~ 40℃ are analyzed by the aid of technological test. The curing agent proportioning at the above temperatures was obtained.%由于脂硬化水玻璃砂硬化速度及强度等指标对环境温度敏感,在生产过程中,需要根据环境条件及时调整固化剂配比,本文通过工艺试验,分析了在0 ~ 10℃、11~ 20℃、21~30℃和30~40℃环境条件下脂硬化水玻璃砂的工艺配比与可使用时间、硬化时间、抗拉强度的关系,得出在上述温度环境下的固化剂配比.

  15. The extraction of bitumen from western oil sands. Final report, July 1989--September 1993

    Energy Technology Data Exchange (ETDEWEB)

    Oblad, A.G.; Bunger, J.W.; Dahlstrom, D.A.; Deo, M.D.; Fletcher, J.V.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1994-03-01

    Research and development of surface extraction and upgrading processes of western tar sands are described. Research areas included modified hot water, fluidized bed, and rotary kiln pyrolysis of tar sands for extraction of bitumen. Bitumen upgrading included solvent extraction of bitumen, and catalytic hydrotreating of bitumen. Characterization of Utah tar sand deposits is also included.

  16. Antimicrobial sand via adsorption of cationic Moringa oleifera protein.

    Science.gov (United States)

    Jerri, Huda A; Adolfsen, Kristin J; McCullough, Lauren R; Velegol, Darrell; Velegol, Stephanie B

    2012-01-31

    Moringa oleifera (Moringa) seeds contain a natural cationic protein (MOCP) that can be used as an antimicrobial flocculant for water clarification. Currently, the main barrier to using Moringa seeds for producing potable water is that the seeds release other water-soluble proteins and organic matter, which increase the concentration of dissolved organic matter (DOM) in the water. The presence of this DOM supports the regrowth of pathogens in treated water, preventing its storage and later use. A new strategy has been established for retaining the MOCP protein and its ability to clarify and disinfect water while removing the excess organic matter. The MOCP is first adsorbed and immobilized onto sand granules, followed by a rinsing step wherein the excess organic matter is removed, thereby preventing later growth of bacteria in the purified water. Our hypotheses are that the protein remains adsorbed onto the sand after the functionalization treatment, and that the ability of the antimicrobial functionalized sand (f-sand) to clarify turbidity and kill bacteria, as MOCP does in bulk solution, is maintained. The data support these hypotheses, indicating that the f-sand removes silica microspheres and pathogens from water, renders adhered Escherichia coli bacteria nonviable, and reduces turbidity of a kaolin suspension. The antimicrobial properties of f-sand were assessed using fluorescent (live-dead) staining of bacteria on the surface of the f-sand. The DOM that can contribute to bacterial regrowth was shown to be significantly reduced in solution, by measuring biochemical oxygen demand (BOD). Overall, these results open the possibility that immobilization of the MOCP protein onto sand can provide a simple, locally sustainable process for producing storable drinking water.

  17. Building with Sand

    Science.gov (United States)

    Ashbrook, Peggy

    2010-01-01

    Children playing in damp sand invariably try to make a tower or a tunnel. By providing experiences with a variety of materials, alone and together, teachers set up the conditions for children to learn through their senses and ensure that a class approaches a topic with a common set of experiences to build on. Learning about the properties of…

  18. Faraday, Jets, and Sand

    NARCIS (Netherlands)

    Sandtke, M.; van der Meer, Roger M.; Versluis, Andreas Michel; Lohse, Detlef

    2003-01-01

    When a 6-mm layer of fine sand with an average grain size of 40 µm is poured into a cylindrical container and shaken vertically, thin jets are seen to emerge from an airy cloud of grains, almost like protuberances from the corona of the sun. A quasi two-dimensional setup reveals the jet-formation

  19. Building with Sand

    Science.gov (United States)

    Ashbrook, Peggy

    2010-01-01

    Children playing in damp sand invariably try to make a tower or a tunnel. By providing experiences with a variety of materials, alone and together, teachers set up the conditions for children to learn through their senses and ensure that a class approaches a topic with a common set of experiences to build on. Learning about the properties of…

  20. Speleothems and Sand Castles

    Science.gov (United States)

    Hance, Trevor; Befus, Kevin

    2015-01-01

    The idea of building sand castles evokes images of lazy summer days at the beach, listening to waves crash, enjoying salty breezes, and just unplugging for a while to let our inner child explore the wonderful natural toys beneath our feet. The idea of exploring caves might evoke feelings and images of claustrophobia or pioneers and Native…

  1. Virksomhedens sande ansigt

    DEFF Research Database (Denmark)

    Lundholt, Marianne Wolff

    2017-01-01

    Er modhistorier en byrde eller en styrke i forandringsprocesser? Hvad stiller vi op, når adgangen til organisationens sande identitet går gennem medarbejdernes modhistorier? Når vi sammenholder denne erkendelse med vores viden om, at medarbejdere helt naturligt afholder sig fra at videregive disse...

  2. Sand (CSW4)

    CSIR Research Space (South Africa)

    Estuarine and Coastal Research Unit

    1982-12-01

    Full Text Available This report is one of a series on Cape Estuaries being published under the general title "The Estuaries of the Cape, Part 2". The report provides information on sand estuary: historical background, abiotic and biotic characteristics. It is pointed...

  3. Sand supply to beaches

    Science.gov (United States)

    Aagaard, Troels

    2017-04-01

    In most cases, beaches and dunes are built by sand that has been transported onshore from the shoreface. While this has been known for a long time, we are still not able to quantitatively predict onshore sediment transport and sand supply to beaches. Sediment transport processes operating during brief, high-energy stormy conditions - when beaches erode and sand moves offshore - are fairly well known and they can be modelled with a reasonable degree of confidence. However, the slower onshore sand transport leading to beach recovery under low-to-moderate energy conditions - and the reason why beaches and dunes exist in the first place - is not yet well understood. This severely limits our capability to understand and predict coastal behaviour on long time scales, for example in response to changing sea level or wave conditions. This paper will discuss issues and recent developments in sediment transport measurement and prediction on the lower and upper shoreface and into the swash zone. The focus will be on the integration and upscaling of small-scale deterministic process measurements into parametric models that may increase modelling capabilities of coastal behaviour on larger temporal and spatial scales.

  4. Erosion phenomena in sand moulds

    Directory of Open Access Journals (Sweden)

    A. Chojecki

    2008-03-01

    Full Text Available Authors studicd the erosion phcnorncna in sand moulds pured with cast iron. Thc study comprises an evaluation of erosionresistance of thc three sands: grccn sand. sand bondcd with inorganic or organic bindcr. It was concluded that thc most resistant is [heclassic green sand with thc addition of 5 B coal dust. Resistance of the sand with organic binder is generally weak and dcvnds onkind of used raisin. Spccinl nztcntion was paid to the sands with no organic bindcr watcr glass and phospha~c. It was Sound that thcirrcsistance depends on dehydratation conditions. When the mould is stored in law humidity of atmosphcrc the very strong crosion canbe expected. It rcsul ts hrn thc micro fractures in the bridges of binders, joining the grains of the sable. This phcnomcna facilitates thetearing away of fragments of sand [tom the surface

  5. A Sand Control System for Light Oil Reservoir

    Institute of Scientific and Technical Information of China (English)

    Xiang Yuzhang

    1996-01-01

    @@ Over 30-year water flooding in light oil sandstone reservoirs with loose argillaceous cement in Karamay oilfield results in severe sand production, varying from well to well with the different date of well completion.

  6. Annual report : 1936-'37 : Sand Lake Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report covers activities on Sand Lake Migratory Waterfowl Refuge during the 1937 fiscal year. Weather conditions, water levels, wildlife,...

  7. Shaly sand formation evaluation in tight gas sands using electrochemical potential measurements

    Science.gov (United States)

    Sharma, M. M.; Jin, M.

    1991-08-01

    Equations are developed that directly relate the shaly conductivity to the electrochemical (membrane) potential (EP). The model is applied to both fully and partially saturated sands. The relationship between the resistivity index and the water saturation is also expressed in terms of a single membrane potential measurement. The Ep measured at different salinities are compared with model prediction using a single membrane potential measurement. Sigma (sub 0) versus Sigma (sub w) curves are then generated using the model equations and compared with measured curves. Experimental results are presented for electrochemical potential measurement made in the lab on 50 tight gs sand samples. It is shown that the measurements can be correlated with CEC although the CEC measured by grinding up the samples was always higher than that estimated from Ep measurements. The Ep measurements are combined with the equations for partial saturation developed in the report to obtain water saturations in a tight gas sand well. Through the example it is shown that it is possible to determine the water saturation in Shaly sands from one membrane potential measurement at a known salinity together with a set of resistivity logs. The results clearly demonstrate the applicability of the method as a practical procedure for Shaly sand information evaluation.

  8. Avaliação de um hidrociclone de Rietema para remoção de areia da água de irrigação Evaluation of Rietema hydrocyclone for sand removal from irrigation water

    Directory of Open Access Journals (Sweden)

    Olívio J. Soccol

    2005-12-01

    Full Text Available Neste trabalho, o principal objetivo foi avaliar a capacidade de um hidrociclone tipo Rietema, com 50 mm de diâmetro, em reter areia suspensa na água de irrigação. O hidrociclone operou com diferenciais de pressão que variaram de 10 a 60 kPa e vazões entre 1.159,90 a 2.603,60 L h-1. A concentração de areia na suspensão variou de 2,81 a 7,01 g L-1. Os resultados mostraram que as melhores eficiências de remoção foram obtidas para os diferenciais de pressão de 10 e 20 kPa, com diâmetros de corte de 50 mm apresentando uma eficiência granulométrica de 70%.In this work, objective was to evaluate the capacity of a Rietema kind of hydrocyclone, with 50 mm diameter, to retain suspended sand in irrigation water. The hydrocyclone was operated with pressure differentials that varied from 10 to 60 kPa and discharges between 1,159.90 and 2,603.60 L h-1. The sand concentration in suspension varied from 2.81 to 7.01 g L-1. The best results were obtained for the pressure differentials of 10 and 20 kPa, with cut diameter sizes of 50 mm showing granulometric efficiency of 70%.

  9. The Test Research of Pearl River Water in Quartz Sand Filtration +Micro-filtration Membrane%石英砂+微滤膜过滤珠江水试验研究

    Institute of Scientific and Technical Information of China (English)

    徐晓然; 孙志民

    2012-01-01

    采用石英砂+微滤膜工艺对广州珠江原水进行了试验研究,运行参数为:石英砂滤速为8.0 m/h,微滤膜通量为28.6 L/m2h,结果表明:浊度的去除效果可达到99%以上,出水浊度在0.18~0.396 NTU之间;菌落总数的去除率受原水水质影响较大,总大肠菌群、耐热大肠菌群去除效果可达到100%;新微滤膜经过2次药洗,第38天后之后微滤膜的工作压力稳定在0.14 MPa左右。%The quartz sand filtration +micro-filtration membrane process was utilized to treat raw water of Guangzhou Pearl river water for test study,The results show that: The significant removal of turbidity was observed above 99 %,and the turbidity outlet was in the range of 0.18~0.396;the quality of raw water strongly influenced the removal of Total amount of the bacterium colony.The removal of Escherichia coli and Heat-resistant coliform group were 100 %;after 2 times chemical-washing of the new micro-filtration membrane,the working pressure stable in 0.14 MPa orm the 38th day.The operation parameters was as follows: the filter speed of Quartz sand filtration was 8.0 m/h,the flux of micro-filtration membrane was 28.6 L/m2h.

  10. Research on control measures for water content in sand product of Dagangshan aggregate processing system%大岗山大坝砂石系统成品砂含水率控制研究

    Institute of Scientific and Technical Information of China (English)

    吴楠; 李宜红; 严君汉

    2014-01-01

    从2012年5月开始,大岗山水电站大坝人工骨料加工系统生产的成品砂含水率一直偏高,现场采取了加密盲沟、完善截排水系统和防雨棚、适当降低石粉含量等措施之后,效果仍不明显。为此,大岗山公司组织对料源质量进行了分析研究,并开展了相应的试验。结果发现含水率偏高的主要原因是大量细颗粒表面裹有保水物质,而第三筛分车间为干法生产,无法去掉保水物质。根据含水率偏高的原因,对砂石系统进行了改造,解决了成品砂含水率偏高的问题。%The production of artificial aggregate processing system for dam construction of Dagangshan hydropower station star-ted in May, 2012. Due to strong water-retaining property of sand product, the water content is higher. The measures of increas-ing blind ditches, perfecting water intercepting and drainage system, properly reducing stone powder content etc. , were adopted but failed. For this reason, Dagangshan company analyzed the material sources and carried out some related tests. The analysis results showed that the main cause was hydrophilic substance on the sand product that was difficult to remove due to dry process production in No. 3 screening plant. In view of the cause, the aggregate processing system was improved and satisfied effect was obtained.

  11. 76 FR 30509 - Court Orders and Legal Processes Affecting Thrift Savings Plan Accounts

    Science.gov (United States)

    2011-05-26

    ... Part 1653 Court Orders and Legal Processes Affecting Thrift Savings Plan Accounts AGENCY: Federal... amendment which subjects TSP accounts to orders issued pursuant to the Mandatory Victims Restitution Act... in which child support orders and MVRA orders are payable. The amendments clarify that these...

  12. On Pluvial Compaction of Sand

    DEFF Research Database (Denmark)

    Jacobsen, Moust

    At the Institute of Civil Engineering in Aalborg model tests on dry sand specimens have been carried out during the last five years. To reduce deviations in test results, the sand laying technique has been carefully studied, and the sand mass spreader constructed. Preliminary results have been...

  13. Microbes in Beach Sands: Integrating Environment, Ecology and Public Health.

    Science.gov (United States)

    Whitman, Richard; Harwood, Valerie J; Edge, Thomas A; Nevers, Meredith; Byappanahalli, Muruleedhara; Vijayavel, Kannappan; Brandão, João; Sadowsky, Michael J; Alm, Elizabeth Wheeler; Crowe, Allan; Ferguson, Donna; Ge, Zhongfu; Halliday, Elizabeth; Kinzelman, Julie; Kleinheinz, Greg; Przybyla-Kelly, Kasia; Staley, Christopher; Staley, Zachery; Solo-Gabriele, Helena M

    2014-09-01

    Beach sand is a habitat that supports many microbes, including viruses, bacteria, fungi and protozoa (micropsammon). The apparently inhospitable conditions of beach sand environments belie the thriving communities found there. Physical factors, such as water availability and protection from insolation; biological factors, such as competition, predation, and biofilm formation; and nutrient availability all contribute to the characteristics of the micropsammon. Sand microbial communities include autochthonous species/phylotypes indigenous to the environment. Allochthonous microbes, including fecal indicator bacteria (FIB) and waterborne pathogens, are deposited via waves, runoff, air, or animals. The fate of these microbes ranges from death, to transient persistence and/or replication, to establishment of thriving populations (naturalization) and integration in the autochthonous community. Transport of the micropsammon within the habitat occurs both horizontally across the beach, and vertically from the sand surface and ground water table, as well as at various scales including interstitial flow within sand pores, sediment transport for particle-associated microbes, and the large-scale processes of wave action and terrestrial runoff. The concept of beach sand as a microbial habitat and reservoir of FIB and pathogens has begun to influence our thinking about human health effects associated with sand exposure and recreational water use. A variety of pathogens have been reported from beach sands, and recent epidemiology studies have found some evidence of health risks associated with sand exposure. Persistent or replicating populations of FIB and enteric pathogens have consequences for watershed/beach management strategies and regulatory standards for safe beaches. This review summarizes our understanding of the community structure, ecology, fate, transport, and public health implications of microbes in beach sand. It concludes with recommendations for future work in

  14. Food web structure in oil sands reclaimed wetlands.

    Science.gov (United States)

    Kovalenko, K E; Ciborowski, J J H; Daly, C; Dixon, D G; Farwell, A J; Foote, A L; Frederick, K R; Costa, J M Gardner; Kennedy, K; Liber, K; Roy, M C; Slama, C A; Smits, J E G

    2013-07-01

    Boreal wetlands play an important role in global carbon balance. However, their ecosystem function is threatened by direct anthropogenic disturbance and climate change. Oil sands surface mining in the boreal regions of Western Canada denudes tracts of land of organic materials, leaves large areas in need of reclamation, and generates considerable quantities of extraction process-affected materials. Knowledge and validation of reclamation techniques that lead to self-sustaining wetlands has lagged behind development of protocols for reclaiming terrestrial systems. It is important to know whether wetlands reclaimed with oil sands process materials can be restored to levels equivalent to their original ecosystem function. We approached this question by assessing carbon flows and food web structure in naturally formed and oil sands-affected wetlands constructed in 1970-2004 in the postmining landscape. We evaluated whether a prescribed reclamation strategy, involving organic matter amendment, accelerated reclaimed wetland development, leading to wetlands that were more similar to their natural marsh counterparts than wetlands that were not supplemented with organic matter. We measured compartment standing stocks for bacterioplankton, microbial biofilm, macrophytes, detritus, and zoobenthos; concentrations of dissolved organic carbon and residual naphthenic acids; and microbial production, gas fluxes, and aquatic-terrestrial exports (i.e., aquatic insect emergence). The total biomass of several biotic compartments differed significantly between oil sands and reference wetlands. Submerged macrophyte biomass, macroinvertebrate trophic diversity, and predator biomass and richness were lower in oil sands-affected wetlands than in reference wetlands. There was insufficient evidence to conclude that wetland age and wetland amendment with peat-mineral mix mitigate effects of oil sands waste materials on the fully aquatic biota. Although high variability was observed within

  15. 富水砂卵石地层注浆参数优化研究%Study on optimization of grouting parameters in water -soaked sand and cobble stratu m

    Institute of Scientific and Technical Information of China (English)

    李享松; 覃娟; 罗概; 邓俊

    2016-01-01

    Choosing reasonable grouting parameter is the key to grouting reinforcement for Water -soaked sand and cobble stratum,which has the characteristics of looseness,large porosity and high permeability.Taking a subway station in Changsha as the project background,in the light of the actual problems of cement -sodium sili-cate slurry grouting including difficultly controlling the setting time and empirically determining grouting hole spacing,the paper has optimized grouting material parameters and hole spacing by indoor grouting material tes-ting,field grouting testing and finite element numerical simulation and proposed the corresponding grouting con-trol standards.It is suggested that water -cement ratio should be 0.8 -1.0,water glass about 40 Baume De-grees,water glass addition 8% -10% and grouting hole spacing about 1.8 m when Water -soaked sand and cobble stratum adopted cement -water class to grout.%富水砂卵石地层具有结构松散、空隙率大、高渗透性的特点,在进行注浆加固设计时,合理地确定注浆参数是注浆加固成功与否的关键。以长沙某地铁车站为工程依托,结合富水砂卵石地层的特点,针对水泥-水玻璃(CS)双液浆注浆凝结时间控制难、注浆孔距设计凭经验确定等问题,通过室内注浆材料试验、现场注浆试验及有限元数值模拟对注浆材料参数及注浆孔距进行优化分析,提出相应的注浆控制标准。研究结果表明:富水砂卵石地层采用 CS 双液浆注浆,当水灰比取0.8~1.0时,水玻璃浓度应控制在40波美度左右,水玻璃掺合量控制在8%~10%,注浆孔间距宜控制在1.8 m 左右。

  16. Measures to Prevent Gushing of Water and Sand in Deep Foundation Pit Structure%深基坑围护结构涌水涌砂防止技术措施

    Institute of Scientific and Technical Information of China (English)

    盛习德; 李柽

    2012-01-01

    The paper briefly analyzes construction risks of gushing water and sand in deep excavations envelope structure. Based on the analysis, structure design of deep foundation pit, construction and excavation of foundation pit at different stages of underground continuous wall seepage and preventive measures are put forward, providing experience for similar projects in the future.%对深基坑工程围护结构涌水涌砂施工风险进行简要分析,在此基础上提出了深基坑围护结构设计、施工及基坑开挖不同阶段地下连续墙渗漏防止措施,为今后类似工程的施工提供经验借鉴。

  17. Analysis on Handling Method for Sand Hole in Lubricating Water Pipeline of Seepage Drainage Pump%渗漏排水泵润滑水管路沙眼的处理方法分析

    Institute of Scientific and Technical Information of China (English)

    黄永华

    2013-01-01

    通过介绍对万家寨水电站渗漏排水泵润滑水管沙眼问题的处理方法,分析了设计选材、地面施工质量以及混凝土中埋设管路根部防锈等问题。经过处理,万家寨水电站设备运行安全、可靠、高效。%In this paper, the handling method for sand hole in the lubricating water pipeline of seepage drainage pump of Wanjiazhai Hy-dropower Station is introduced.Furthermore, handling material selection, ground construction quality and rust protection of the root of the pipeline buried in concrete are analyzed.Through the treatment, Wanjiazhai Hydropower Station operates safely, reliably and in high effi-ciency.

  18. Research and Application of the Support Project of the Foundation Bearing Sand in Deep water%高地下水位含流沙基础开挖支护方案的研究和应用

    Institute of Scientific and Technical Information of China (English)

    黄少鹏

    2014-01-01

    This paper described the comprehensive research on the various measures for excavation support of the foun- dation bearing sand in deep water of the foundation drainage trench excavation construction in the municipal engineering of Angola Republic SãoPedro. And the author hoped to provide a useful reference for engineering construction schemes in sim- ilar geological conditions.%文章简述了在安哥拉共和国市政工程SãoPedro排水渠沟槽基础开挖施工中,通过对高地下水位、含流砂基础开挖支护的各种方案措施的综合研究,希望对有类似地质情况工程施工方案的研究和选择提供有益参考。

  19. PROCESSING OF MONAZITE SAND

    Science.gov (United States)

    Calkins, G.D.; Bohlmann, E.G.

    1957-12-01

    A process for the recovery of thorium, uranium, and rare earths from monazite sands is presented. The sands are first digested and dissolved in concentrated NaOH, and the solution is then diluted causing precipitation of uranium, thorium and rare earth hydroxides. The precipitate is collected and dissolved in HCl, and the pH of this solution is adjusted to about 6, precipitating the hydroxides of thorium and uranium but leaving the rare earths in solution. The rare earths are then separated from the solution by precipitation at a still higher pH. The thorium and uranium containing precipitate is redissolved in HNO/sub 3/ and the two elements are separated by extraction into tributyl phosphate and back extraction with a weakly acidic solution to remove the thorium.

  20. Moving sand dunes

    CERN Document Server

    Sparavigna, Amelia Carolina

    2011-01-01

    In several desert areas, the slow motion of sand dunes can be a challenge for modern human activities and a threat for the survival of ancient places or archaeological sites. However, several methods exist for surveying the dune fields and estimate their migration rate. Among these methods, the use of satellite images, in particular of those freely available on the World Wide Web, is a convenient resource for the planning of future human settlements and activities.

  1. Compressive Strength of Compacted Clay-Sand Mixes

    Directory of Open Access Journals (Sweden)

    Faseel Suleman Khan

    2014-01-01

    Full Text Available The use of sand to improve the strength of natural clays provides a viable alternative for civil infrastructure construction involving earthwork. The main objective of this note was to investigate the compressive strength of compacted clay-sand mixes. A natural clay of high plasticity was mixed with 20% and 40% sand (SP and their compaction and strength properties were determined. Results indicated that the investigated materials exhibited a brittle behaviour on the dry side of optimum and a ductile behaviour on the wet side of optimum. For each material, the compressive strength increased with an increase in density following a power law function. Conversely, the compressive strength increased with decreasing water content of the material following a similar function. Finally, the compressive strength decreased with an increase in sand content because of increased material heterogeneity and loss of sand grains from the sides during shearing.

  2. Geologic and paleoecologic studies of the Nebraska Sand Hills

    Science.gov (United States)

    Ahlbrandt, Thomas S.; Fryberger, S.G.; Hanley, John H.; Bradbury, J. Platt

    1980-01-01

    PART A: The Nebraska Sand Hills are an inactive, late Quaternary, most probably Holocene, dune field (covering 57,000 km 2 ) that have been eroded along streams and in blowouts, resulting in excellent lateral and vertical exposures of the stratification of dune and interdune sediments. This paper presents new data on the geometry, primary sedimentary structures, modification of sedimentary structures, direction of sand movement, and petrography of these eolian deposits. Eolian deposits of the Sand Hills occur as relatively thin (9-24 m) 'blanket' sands, composed of a complex of dune and discontinuous, diachronous interdune deposits unconformably overlying fluviolacustrine sediments. The internal stratification of large dunes in the Sand Hills (as high as 100 m), is similar to the internal stratification of smaller dunes of the same type in the Sand Hills, differing only in scale. Studies of laminae orientation in the Sand Hills indicate that transverse, barchan, and blowout dunes can be differentiated in rocks of eolian origin using both the mean dip angle of laminae and the mean angular deviation of dip direction. A variety of secondary structures modify or replace primary eolian stratification in the Sand Hills, the more common of which are dissipation structures and bioturbation. Dissipation structures in the Sand Hills may develop when infiltrating water deposits clay adjacent to less permeable layers in the sand, or along the upper margins of frozen layers that form in the sands during winter. Cross-bed measurements from dunes of the Nebraska Sand Hills necessitate a new interpretation of the past sand transport directions. The data from these measurements indicate a general northwest-to-southeast drift of sand, with a more southerly drift in the southeast part of the Sand Hills. A large area of small dunes Sand Hills was interpreted by him on the basis of morphology only. We interpret these as transverse-ridge dunes that were generally moving to the south

  3. Peripheral Oilfields Coated Sand Fracturing Technology Adaptability of Water Control%外围油田覆膜砂控水压裂技术适应性探讨

    Institute of Scientific and Technical Information of China (English)

    张传华

    2012-01-01

    针对葡萄花储层开发中后期中高含水井,常规措施压裂后经常出现大幅度增液,而增油幅度较小甚至不增油,即便压裂后达到了预期增油效果,其含水上升速度也较快,有效期难于控制。结合大庆油田外围地层裂缝走向、渗透率、油层发育等情况以及井层压前产液、含水等状况,开展了现场试验,通过压裂工艺将覆膜砂携至裂缝中,生产时形成一条高含油饱和带,实现覆膜砂对油水流动能力的选择,达到具有堵水不堵油特性。通过近几年效果跟踪统计,分析其增油降水的效果及适应性,该技术可有效提高油井压裂后油层动用程度,降低油井采出液的含水率,拓宽压裂选井选层范围。%Putaohua reservoir development in the middle and late high water cut wells after fracturing,conventional measures often appear substantially liquid increasing,and increasing oil less or even oil problems,even after fracturing has achieved the expected effect of increasing oil,the water cut rising fast,effective period is difficult to control.In this paper,combined with the periphery of Daqing oil field,permeability,formation fracture to the reservoir development such as well before the lamination of produced fluid,such as water,carried out the field test,the fracturing process will be coated sand carrying to crack,production forms a high oil saturation zone,realization of coated sand on oil and water flow capacity choice,achieve have plugging water and not plugging oil characteristics,in recent years through the effect of tracking statistics,summary analysed the oil increasing precipitation effect and adaptability.The technology can effectively improve after fracturing of oil reservoir producing degree,reduce the oil well produced fluid moisture content,widen the fracturing well and layer selection range.

  4. Booming Sand Dunes

    Science.gov (United States)

    Vriend, Nathalie

    "Booming" sand dunes are able to produce low-frequency sound that resembles a pure note from a music instrument. The sound has a dominant audible frequency (70-105 Hz) and several higher harmonics and may be heard from far distances away. A natural or induced avalanche from a slip face of the booming dune triggers the emission that may last for several minutes. There are various references in travel literature to the phenomenon, but to date no scientific explanation covered all field observations. This thesis introduces a new physical model that describes the phenomenon of booming dunes. The waveguide model explains the selection of the booming frequency and the amplification of the sound in terms of constructive interference in a confined geometry. The frequency of the booming is a direct function of the dimensions and velocities in the waveguide. The higher harmonics are related to the higher modes of propagation in the waveguide. The experimental validation includes quantitative field research at the booming dunes of the Mojave Desert and Death Valley National Park. Microphone and geophone recordings of the acoustic and seismic emission show a variation of booming frequency in space and time. The analysis of the sensor data quantifies wave propagation characteristics such as speed, dispersion, and nonlinear effects and allows the distinction between the source mechanism of the booming and the booming itself. The migration of sand dunes results from a complicated interplay between dune building, wind regime, and precipitation. The morphological and morphodynamical characteristics of two field locations are analyzed with various geophysical techniques. Ground-penetrating radar images the subsurface structure of the dunes and reveal a natural, internal layering that is directly related to the history of dune migration. The seismic velocity increases abruptly with depth and gradually increases with downhill position due to compaction. Sand sampling shows local

  5. Study on Key Technology of Using Shell Sand as Backfill for Sea Reclamation

    Institute of Scientific and Technical Information of China (English)

    LI Neng-hui; QU Yi-rong; HE Wen-qin; CHEN Hui

    2005-01-01

    The results of a study on the key technology of using shell sand, a kind of sea sand, as backfill for sea reclamation are described briefly. Laboratory tests show that the physical and mechanical properties of shell sand are as good as normal quartz sand. Based on the chemical test and durability test of shell sand it could be concluded that the influence of corrosion of shell sand by acid rain and sea water might be ignored in the evaluation of the safety and durability of the engineering project. The results of field improvement tests show that the bearing capacity of shell sand backfill foundation is more than 200 kPa after vibroflotation improvement or dynamic compaction improvement. The shell sand is a good backfill material for sea reclamation.

  6. Laboratory studies of dune sand for the use of construction industry in Sri Lanka

    Science.gov (United States)

    de Silva Jayawardena, Upali; Wijesuriya, Roshan; Abayaweera, Gayan; Viduranga, Tharaka

    2015-04-01

    With the increase of the annual sand demand for the construction industry the excessive excavation of river sand is becoming a serious environmental problem in Sri Lanka. Therefore, it is necessary to explore the possibility for an alternative to stop or at least to minimize river sand mining activities. Dune sand is one of the available alternative materials to be considered instead of river sand in the country. Large quantities of sand dunes occur mainly along the NW and SE coastal belt which belong to very low rainfall Dry Zone coasts. The height of dune deposits, vary from 1m to about 30 meters above sea level. The objective of this paper is to indicate some studies and facts on the dune sand deposits of Sri Lanka. Laboratory studies were carried out for visual observations and physical properties at the initial stage and then a number of tests were carried out according to ASTM standards to obtain the compressive strength of concrete cylinders and mortar cubes mixing dune sand and river sand in different percentages keeping a constant water cement ratio. Next the water cement ratio was changed for constant dune sand and river sand proportion. Microscopic analysis shows that the dune sand consist of 95 % of quartz and 5 % of garnet, feldspar, illmenite and other heavy minerals with clay, fine dust, fine shell fragments and organic matters. Grains are sub-rounded to angular and tabular shapes. The grain sizes vary from fine to medium size of sand with silt. The degree of sorting and particle size observed with dune sands are more suited with the requirement of fine aggregates in the construction industry. The test result indicates that dune sand could be effectively used in construction work without sieving and it is ideal for wall plastering due to its'-uniformity. It could also be effectively used in concrete and in mortars mixing with river sand. The best mixing ratio is 75% dune sand and 25% river sand as the fine aggregate of concrete. For mortar the mixing

  7. On whether mirror neurons play a significant role in processing affective prosody.

    Science.gov (United States)

    Ramachandra, Vijayachandra

    2009-02-01

    Several behavioral and neuroimaging studies have indicated that both right and left cortical structures and a few subcortical ones are involved in processing affective prosody. Recent investigations have shown that the mirror neuron system plays a crucial role in several higher-level functions such as empathy, theory of mind, language, etc., but no studies so far link the mirror neuron system with affective prosody. In this paper is a speculation that the mirror neuron system, which serves as a common neural substrate for different higher-level functions, may play a significant role in processing affective prosody via its connections with the limbic lobe. Actual research must apply electrophysiological and neuroimaging techniques to assess whether the mirror neuron systems underly affective prosody in humans.

  8. Comparison of fouling characteristics of two different poly-vinylidene fluoride microfiltration membranes in a pilot-scale drinking water treatment system using pre-coagulation/sedimentation, sand filtration, and chlorination.

    Science.gov (United States)

    Chae, So-Ryong; Yamamura, Hiroshi; Ikeda, Keiichi; Watanabe, Yoshimasa

    2008-04-01

    Two pilot-scale hybrid water treatment systems using two different poly-vinylidene fluoride (PVDF) microfiltration (MF) membranes (i.e. symmetric and composite) were operated at a constant permeate flux of 104.2l m(-2)h(-1) (=2.5 md(-1)) with a pre-coagulation/sedimentation, sand filtration (SF), and chlorination to produce potable water from surface water. Turbidity was removed completely. And humic substances, Al, and Fe were removed very well by the pilot-scale membrane system. To control microbial growth and mitigate membrane fouling, a NaOCl solution was injected into the effluent from SF before reaching the two membranes (pre-chlorination). However, it adversely affected membrane fouling due to the oxidization and adsorption of inorganic substances such as Al, Fe, and Mn. In the next run, the NaOCl was introduced during backwash (post-chlorination). As compared with the result of pre-chlorination, this change increased the operating period of the symmetric and the composite membranes from about 10 and 50 days to about 60 and 200 days, respectively.

  9. Post-liquefaction reconsolidation of sand.

    Science.gov (United States)

    Adamidis, O; Madabhushi, G S P

    2016-02-01

    Loosely packed sand that is saturated with water can liquefy during an earthquake, potentially causing significant damage. Once the shaking is over, the excess pore water pressures that developed during the earthquake gradually dissipate, while the surface of the soil settles, in a process called post-liquefaction reconsolidation. When examining reconsolidation, the soil is typically divided in liquefied and solidified parts, which are modelled separately. The aim of this paper is to show that this fragmentation is not necessary. By assuming that the hydraulic conductivity and the one-dimensional stiffness of liquefied sand have real, positive values, the equation of consolidation can be numerically solved throughout a reconsolidating layer. Predictions made in this manner show good agreement with geotechnical centrifuge experiments. It is shown that the variation of one-dimensional stiffness with effective stress and void ratio is the most crucial parameter in accurately capturing reconsolidation.

  10. Comparison of GC-MS and FTIR methods for quantifying naphthenic acids in water samples.

    Science.gov (United States)

    Scott, Angela C; Young, Rozlyn F; Fedorak, Phillip M

    2008-11-01

    The extraction of bitumen from the oil sands in Canada releases toxic naphthenic acids into the process-affected waters. The development of an ideal analytical method for quantifying naphthenic acids (general formula C(n)H(2n+Z)O(2)) has been impeded by the complexity of these mixtures and the challenges of differentiating naphthenic acids from other naturally-occurring organic acids. The oil sands industry standard FTIR method was compared with a newly-developed GC-MS method. Naphthenic acids concentrations were measured in extracts of surface and ground waters from locations within the vicinity of and away from the oil sands deposits and in extracts of process-affected waters. In all but one case, FTIR measurements of naphthenic acids concentrations were greater than those determined by GC-MS. The detection limit of the GC-MS method was 0.01 mg L(-1) compared to 1 mg L(-1) for the FTIR method. The results indicated that the GC-MS method is more selective for naphthenic acids, and that the FTIR method overestimates their concentrations.

  11. Assessing Risks of Shallow Riparian Groundwater Quality Near an Oil Sands Tailings Pond.

    Science.gov (United States)

    Roy, J W; Bickerton, G; Frank, R A; Grapentine, L; Hewitt, L M

    2016-07-01

    The potential discharge of groundwater contaminated by oil sands process-affected water (OSPW) is a concern for aquatic ecosystems near tailings ponds. Groundwater in the area, but unaffected by OSPW, may contain similar compounds, complicating the assessment of potential ecological impacts. In this study, 177 shallow groundwater samples were collected from riparian areas along the Athabasca River and tributaries proximate to oil sands developments. For "pond-site" samples (71; adjacent to study tailings pond), Canadian aquatic life guidelines were exceeded for 11 of 20 assessed compounds. However, "non-pond" samples (54; not near any tailings pond) provided similar exceedances. Statistical analyses indicate that pond-site and non-pond samples were indistinguishable for all but seven parameters assessed, including salts, many trace metals, and fluorescence profiles of aromatic naphthenic acids (ANA). This suggests that, regarding the tested parameters, groundwater adjacent to the study tailings pond generally poses no greater ecological risk than other nearby groundwaters at this time. Multivariate analyses applied to the groundwater data set separated into 11 smaller zones support this conclusion, but show some variation between zones. Geological and potential OSPW influences could not be distinguished based on major ions and metals concentrations. However, similarities in indicator parameters, namely ANA, F, Mo, Se, and Na-Cl ratio, were noted between a small subset of samples from two pond-site zones and two OSPW samples and two shallow groundwater samples documented as likely OSPW affected. This indicator-based screening suggests that OSPW-affected groundwater may be reaching Athabasca River sediments at a few locations. © 2016 Her Majesty the Queen in Right of Canada. Groundwater © 2016, National Ground Water Association.

  12. Cumulative environmental management and the oil sands

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    In response to concerns regarding the cumulative environmental impacts of oil sands development within the Athabasca oil sands deposit, the government of Alberta established a Regional Sustainable Development Strategy (RSDS) to balance development with environmental protection. The environmental issues identified through the RSDS were addressed by the Cumulative Environmental Management Association (CEMA). CEMA's boundary is the Wood Buffalo region of northeastern Alberta. It identifies existing and future environmental effects in the region and proposes recommendations to regulatory bodies for reducing environmental impacts associated with oil sands development. This presentation outlined some of the 55 stakeholder representatives of CEMA, including Alberta government departments associated with resource development, oil sand developers within the region, and Aboriginal communities and First Nations. These stakeholders provide input on sector priorities and agree on environmental thresholds. Established working groups also address technical and scientific research issues identified in the RSDS such as sustainable ecosystems; surface waters; trace metals and air contaminants; nitrogen oxides and sulphur dioxides; and land reclamation. To date, CEMA has submitted more than 50 reports and has made 4 major environmental recommendations for trace metal management, ecosystem management tools, a framework for acid deposition management, and a landscape design checklist. tabs., figs.

  13. Thermal Properties of Foundry Mould Made of Used Green Sand

    Directory of Open Access Journals (Sweden)

    Krajewski P.K.

    2016-03-01

    Full Text Available The paper presents results of measuring heat diffusivity and thermal conductivity coefficients of used green foundry sand in temperature range ambient − 600 °C. During the experiments a technical purity Cu plate was cast into the green-sand moulds. Basing on measurements of the mould temperature field during the solidification of the casting, the temperature relationships of the measured properties were evaluated. It was confirmed that the obtained relationships are complex and that water vaporization strongly influences thermal conductivity of the moulding sand in the first period of the mould heating by the poured and solidified casting.

  14. High Temperature Thermal Properties of Bentonite Foundry Sand

    Directory of Open Access Journals (Sweden)

    Krajewski P.K.

    2015-06-01

    Full Text Available The paper presents results of measuring thermal conductivity and heat capacity of bentonite foundry sand in temperature range ambient - 900­­°C. During the experiments a technical purity Cu plate was cast into the green-sand moulds. Basing on measurements of the mould temperature field during the solidification of the casting, the temperature relationships of the measured properties were evaluated. It was confirmed that water vaporization strongly influences thermal conductivity of the moulding sand in the first period of the mould heating by the poured casting.

  15. Compressive behavior of fine sand.

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Bradley E. (Air Force Research Laboratory, Eglin, FL); Kabir, Md. E. (Purdue University, West Lafayette, IN); Song, Bo; Chen, Wayne (Purdue University, West Lafayette, IN)

    2010-04-01

    The compressive mechanical response of fine sand is experimentally investigated. The strain rate, initial density, stress state, and moisture level are systematically varied. A Kolsky bar was modified to obtain uniaxial and triaxial compressive response at high strain rates. A controlled loading pulse allows the specimen to acquire stress equilibrium and constant strain-rates. The results show that the compressive response of the fine sand is not sensitive to strain rate under the loading conditions in this study, but significantly dependent on the moisture content, initial density and lateral confinement. Partially saturated sand is more compliant than dry sand. Similar trends were reported in the quasi-static regime for experiments conducted at comparable specimen conditions. The sand becomes stiffer as initial density and/or confinement pressure increases. The sand particle size become smaller after hydrostatic pressure and further smaller after dynamic axial loading.

  16. 沉砂对聚并等流分离器的油水分离效果试验研究%Study of Effect of Sink Sand on Oil-water Separation in Gather and Flow Pattern Oil-water Separator

    Institute of Scientific and Technical Information of China (English)

    韩洪升; 李霄峰; 吕宁; 赵淑红

    2012-01-01

    In order to evaluate the separation efficiency of oil-water mixture of the coherent and co-current flow pattern oil-water separator, the indoor wellbore simulation experiment was made. The relation curve was drawn between the fluid volume of single cup feeding at different water-content and the moisture content of oil-water mixture after separation. The test showed that,at single-cup flow rate (less than 0. 2 m3/d) ,sand drainage hole and sunk sand had no efficiency to coherent and co-current flow hydrocyclone. The performance of hydrocyclone with four sand drainage holes is better than other ones with holes.%为评价聚并等流型油水分离器在排砂的同时对井下油水混合物的分离效果,进行了室内井筒模拟试验,绘制了不同含水率时单杯进液量与油水分离后混合液含水率的关系曲线.试验表明:在单杯流量<0.2 m3/d时,排砂孔和沉砂对聚并等流分离器的油水分离效果没有明显影响;4个排砂孔的分离器沉砂分离效果要优于其他个数排砂孔的分离器.

  17. Sand dollar sites orogenesis

    Science.gov (United States)

    Amos, Dee

    2013-04-01

    The determinology of the humble sand dollars habitat changing from inception to the drastic evolution of the zone to that of present day. Into the cauldron along the southern Californian 'ring of fire' lithosphere are evidence of geosynclinals areas, metasedimentary rock formations and hydrothermal activity. The explanation begins with 'Theia' and the Moon's formation, battles with cometary impacts, glacial ages, epochs with evolutionary bottlenecks and plate tectonics. Fully illustrated the lecture includes localised diagrams and figures with actual subject photographic examples of plutonic, granitic, jade and peridodite. Finally, the origins of the materials used in the lecture are revealed for prosecution by future students and the enjoyment of interested parties in general.

  18. Sand Storms Trigger Alarm

    Institute of Scientific and Technical Information of China (English)

    LI LI

    2010-01-01

    @@ After an unusually humid winter with at least 10 snowfalls in Beijing, a severe andstorm blown by strong winds bringing with it thousands of tons of desert sand took many residents of the city by surprise.On the morning of March 20, Beijingers woke up to see clouds of yellow dust in the air and a sky that was an ominous orange in color.The loose soil and dust that had traveled htmdreds of miles from deserts in Mongolia and China's northwest blanketed Beijing's streets, covering parked vehicles, bikes, roofs and even plant life,as well as making its way into people's homes.

  19. Fortune Cookie Sand Dunes

    Science.gov (United States)

    2003-01-01

    MGS MOC Release No. MOC2-432, 25 July 2003This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a field of small barchan sand dunes in the north polar region near 71.7oN, 51.3oW. Some of them are shaped like fortune cookies. The message these dunes provide: winds blow through this region from the lower right toward the upper left. The steep slip face slopes of these dunes, which point toward the upper left, indicate the wind direction. The scene is illuminated by sunlight from the upper right. The image is 3 km (1.9 mi) wide.

  20. A family of sand automata

    CERN Document Server

    Faulkner, Nicholas

    2012-01-01

    We study some dynamical properties of a family of two-dimensional cellular automata: those that arise from an underlying one dimensional sand automaton whose local rule is obtained using a latin square. We identify a simple sand automaton G whose local rule is algebraic, and classify this automaton as having equicontinuity points, but not being equicontinuous. We also show it is not surjective. We generalise some of these results to a wider class of sand automata.

  1. Dilatometric Characterization of Foundry Sands

    Directory of Open Access Journals (Sweden)

    M. Břuska

    2012-04-01

    Full Text Available The goal of this contribution is summary of physical – chemistry properties of usually used foundry silica and no – silica sands in Czech foundries. With the help of dilatometry analysis theoretical assumptions of influence of grain shape and size on dilatation value of sands were confirmed. Determined was the possibility of dilatometry analysis employment for preparing special (hybrid sands with lower and/or more linear character of dilatation.

  2. Model test study of evaporation mechanism of sand under constant atmospheric condition

    OpenAIRE

    Cui, Yu Jun; Ding, Wenqi; SONG, Weikang

    2014-01-01

    The evaporation mechanism of Fontainebleau sand using a large-scale model chamber is studied. First, the evaporation test on a layer of water above sand surface is performed under various atmospheric conditions, validating the performance of the chamber and the calculation method of actual evaporation rate by comparing the calculated and measured cumulative evaporations. Second,the evaporation test on sand without water layer is conducted under constant atmospheric condition. Both the evoluti...

  3. Biological soil crusts cause subcritical water repellency in a sand dune ecosystem located along a rainfall gradient in the NW Negev desert, Israel

    Directory of Open Access Journals (Sweden)

    Keck Hannes

    2016-06-01

    Full Text Available The biological soil crusts (BSCs in the NW Negev cause local water redistribution by increasing surface runoff. The effects of pore clogging and swelling of organic and inorganic crust components were intensively investigated in earlier studies. However, the effect of water repellency (WR was not addressed systematically yet. This study investigates subcritical WR of BSCs in three different study sites in the NW Negev. For this purpose, three common methods to determine soil WR were used: (i the repellency index (RI method (ii the water drop penetration time (WDPT test and (iii the Wilhelmy plate method (WPM. Furthermore, the potential influence of WR on local water redistribution is discussed and the applied methods are compared. We found the BSC to be subcritically water repellent. The degree of WR may only affect water redistribution on a microscale and has little influence on the ecosystem as a whole. The RI method was clearly the most appropriate to use, whereas the WDPT and the WPM failed to detect subcritical WR.

  4. Triaxial tests in Fontainebleau sand

    DEFF Research Database (Denmark)

    Latini, Chiara; Zania, Varvara

    2016-01-01

    The purpose of this internal report is to examine the influence of relative density on the strength and deformation characteristics of Fontainebleau sand. Compression triaxial tests were performed on saturated sand samples with different densities and initial confining pressure. Note that the tes......The purpose of this internal report is to examine the influence of relative density on the strength and deformation characteristics of Fontainebleau sand. Compression triaxial tests were performed on saturated sand samples with different densities and initial confining pressure. Note...... that the testing procedure and the data processing were carried out according to the specifications of ETCS-F1.97....

  5. Analysis and treatment of the water gushing and sand boiling of certain pit excavation in Tianjin%天津某基坑开挖涌水冒砂原因分析及处理

    Institute of Scientific and Technical Information of China (English)

    焦志亮; 符亚兵; 唐海明; 曹会

    2013-01-01

    本文以天津某深基坑工程为例,简述了该深基坑场地周围的工程地质及水文地质条件,并简单介绍了基坑支护及降水设计方案.在基坑开挖过程中,针对出现的涌水冒砂问题进行了原因分析.采用“疏导为主,封堵为辅”的指导理念,采取“分散收集,集中排出”的解决方案,并指出施工顺序在整个工程中的重要性.最终解决了该基坑的涌水冒砂问题,使得工程后续工作顺利正常地进行.通过该实例,简单总结了深基坑降水施工过程中的注意事项及遇到同类问题时的处理措施.%Taking certain deep pit excavation in Tianjin as the example, the engineering geological and hydrogeological conditions of the deep foundation pit and the design scheme of the pit retaining and watering are briefly introduced. During the excavation of the foundation pit, the reasons of the water gushing and sand boiling at the pit bottom are analyzed. The guiding philosophy "diverting as the main means, blocking as the secondary means" is adopted, and the solution scheme "decentralized collection, centralized discharge" is taken. The importance of the construction sequence in the whole project is pointed out. Finally the water gushing and sand boiling of the foundation pit are solved, which ensure the follow-up work smoothly and normally. Through the example, the precautions and measures to deal with the similar problems during the construction of the deep foundation pit are briefly summarized.

  6. Measurement of fine particulate matter water-soluble inorganic species and precursor gases in the Alberta Oil Sands Region using an improved semicontinuous monitor.

    Science.gov (United States)

    Hsu, Yu-Mei; Clair, Thomas A

    2015-04-01

    The ambient ion monitor-ion chromatography (AIM-IC) system, which provides hourly measurements of the main chemical components of PM2.5 (particulate matter with an aerodynamic diameterPM2.5 sampler. The correlation coefficients of SO4(2-) concentrations between the AIM-IC and ADSS and between the AIM-IC and the Partisol PM2.5 sampler were 0.98 and 0.95, respectively. The comparisons also showed no statistically significant difference between the measurement sets, suggesting that the AIM-IC measurements of the PM2.5 chemical composition are comparable to the ADSS and Partisol PM2.5 methods. NH3 concentration in the summer (mean±standard deviation, 1.9±0.7 µg m(-3)) was higher than in the winter (1.3±0.9 µg m(-3)). HNO3 and NO3- concentrations were generally low in the AOSR, and especially in the winter months. NH4+ (0.94±0.96 µg m(-3)) and SO4(2-) (0.58±0.93 µg m(-3)) were the major ionic species of PM2.5. Direct SO2 emissions from oil sands processing operations influenced ambient particulate NH4+ and SO4(2-) values, with hourly concentrations of NH4+ and SO4(2-) measured downwind (~30 km away from the stack) at 10 and 28 µg m(-3). During the regional forest fire event in 2011, high concentrations of NO3-, NH4+, HNO3, NH3, and PM2.5 were observed and the corresponding maximum hourly concentrations were 31, 15, 9.6, 89, and >450 (the upper limit of PM2.5 measurement) µg m(-3), suggesting the formation of NH4NO3. The AOSR in Canada is one of the most scrutinized industrial regions in the developed world due to the extent of oil extraction activities. Because of this, it is important to accurately assess the effect of these operations on regional air quality. In this study, we compare a new analytical approach, AIM-IC, with more standard analytical approaches to understand how local anthropogenic and nonanthropogenic sources (e.g., forest fires) impact regional air quality. With this approach, we also better characterize PM2.5 composition and its precursor

  7. Sand Wave Migrations Within Monterey Submarine Canyon, California

    Science.gov (United States)

    Xu, J.; Wong, F. L.

    2006-12-01

    Repeated high-resolution multi-beam surveys revealed the existence of a sand wave field along the axis of the Monterey submarine canyon between 20 and 300 m water depth. These sand waves range in wave length from 20 to 70 m and 2 to 5 m in height. Comparison of sequential multi-beam grid data (months apart) indicates that the sand waves apparently migrate upcanyon at some places while the same data clearly show that the sand waves migrate downcanyon at other locations. One hypothesis is that strong internal tidal flows, whose upcanyon component is intensified by the narrow canyon, are responsible for forming the sand wave field and for migrating the sand waves upcanyon. Another hypothesis is that the sand wave field is formed by creeping (analogous to the movement within glaciers), and in general they move in the downcanyon direction. A field experiment was conducted in 2005-06 to measure the driving forces (in hypothesis #1) that form and move the sand waves, and to collect the internal sedimentological structure within the sand waves that could reveal information on hypothesis #2. A mooring designed to measure near-floor velocity profiles, temperature, salinity, and sediment concentration in the water column was deployed for one year (June 2005 -July 2006) at 250 m water depth, slightly downcanyon of the sand wave field. In addition, a mapping survey was conducted in February, 2006 for collecting multi-beam and chirp profiles in the canyon head area of the sand wave field. Preliminary examination of the ADCP (downward looking) showed some very interesting features - the near- floor current dramatically changes with the spring-neap cycle of the surface tide. The time variation of the along-canyon current during neap tides - a sudden jump of upcanyon velocity before gradually tapering down, is typical of internal tides (internal bores). The time variation during spring tides when along canyon velocities reverse directions from upcanyon to downcanyon and gradually

  8. Coagulation-flocculation in leachate treatment using modified micro sand

    Science.gov (United States)

    Thaldiri, Nur Hanani; Halim, Azhar Abdul

    2013-11-01

    Sanitary landfill leachate is considered as highly polluted wastewater, without any treatment, discharging into water system will cause underground water and surface water pollutions. This study was to investigate the treatability of the semi-aerobic landfill leachate via coagulation-flocculation using poly-aluminum chloride (PAC), cationic polymer, and modified micro sand. Leachate was collected from Pulau Burung Sanitary Landfill (PBSL) located in Penang, Malaysia. Coagulation-flocculation was performed by using jar test equipment and the effect of pH, dose of coagulant and dose of polymer toward removal of chemical oxygen demand (COD), color and suspended solid (SS) were examined. Micro sand was also used in this study to compare settling time of coagulation-flocculation process. The optimum pH, dose of coagulant (PAC) and dose of polymer (cationic) achieved were 7.0, 1000 mg/L and 8 mg/L, respectively. The dose of micro sand used for the settling time process was 300 mg/L. Results showed that 52.66% removal of COD, 97.16% removal of SS and 96.44% removal of color were achieved under optimum condition. The settling times for the settling down of the sludge or particles that formed during coagulation-flocculation process were 1 min with modified sand, 20 min with raw micro sand and 45 min without micro sand.

  9. 富水隧道全风化花岗岩和蚀变大理岩段涌水涌砂加固治理技术%The Control of Sand-gushing and Water-bursting of Water-rich Tunnel Located in Area with Fully Weathered Granite and Alteration Marble

    Institute of Scientific and Technical Information of China (English)

    周运祥

    2015-01-01

    The section DK554+400 ~ +456 of Dongkeling tunnel on Guiyang-Guangzhou railway is located in the area with fully weathered granite and alteration marble. During the construction, sand-gushing and water-bursting often arise, not only increasing the difficulties but also posing long-term security risks. In view of the sand-gushing, water-bursting and other defects during the period of construction of the tunnel, it is effective to control sand-gushing and water-bursting through combination of plugging and drainage i. e. sleeve valve pipe grouting around the tunnel and steel pipe pile grouting at tunnel bottom, and setting-up drainage holes. The successful practices and technical parameters can be referred to similar project.%贵广铁路东科岭隧道DK554+400~+456段处于全风化花岗岩、蚀变大理岩区接触带,隧道施工遭遇了长期的涌水涌砂等病害。结合东科岭隧道施工期间的涌水、涌砂概况及病害成因,治理采用堵排结合,即洞身全风化花岗岩段采用袖阀管注浆、仰拱底部蚀变大理岩部位采用钢管桩注浆加固,同时设置泄水洞等措施,成功解决了涌水涌砂加固治理难题。

  10. Production comparisons of Chinese water chestnut [Eleocharis dulcis (Burm. f.) Trin. ex Hensch] functional corms grown in hydroponics versus flooded sand

    Science.gov (United States)

    Chinese water chestnut [Eleocharis dulcis (Burm. f.) Trin. ex Hensch.] corms are used as a canned or raw vegetable worldwide and may have potential use as a functional vegetable for human health uses. The accessions in the USDA, ARS, Plant Genetic Resources Conservation Unit do not produce very many...

  11. Oil sands to the rescue: oil sand microbial communities can degrade recalcitrant alkyl phenyl alkanoic acids

    Energy Technology Data Exchange (ETDEWEB)

    Whitby, Corinne [University of Essex (Canada)], email: cwhitby@essex.ac.uk

    2011-07-01

    Almost half of all global oil reserves are found as biodegraded heavy oils found in vast tar sand deposits located in North and South America and these account for 47% of Canadian oil production. Oil sand extraction generates large amounts of toxic waste water, known as oil sand process waters (OSPW), that are stored in large tailing ponds that contain toxic compounds like naphthenic acids (NAs). The presence of NAs creates problems like toxicity, corrosion, and the formation of calcium napthenate deposits which block pipelines and other infrastructure and need to be removed. This paper presents oil sand microbial communities that can degrade these NAs. The approach is to apply new aliphatic and aromatic NAs as substrates to supplement and identify NA degrading microbes and also to identify the metabolites produced and explain NA degradation pathways and the functional genes involved. The chemistry and the processes involved are explained. From the results, it is suggested that pure cultures of P. putida KT2440 be used against NAs.

  12. Pathogen removal using saturated sand colums supplemented with hydrochar

    OpenAIRE

    Chung, J W

    2015-01-01

    This PhD study has evaluated hydrochars derived from biowastes as adsorbents for pathogen removal in water treatment. Pathogen removal experiments were conducted by carrying out breakthrough analysis using a simple sand filtration set-up. Glass columns packed by 10 cm sand bed supplemented with minor amount of hydrochar (1.5 %, w/w) were flushed with artificial ground water seeded with test microorganisms at an upward flow rate of 1 mL / min. Either back flushing or deionized water flushing w...

  13. Sphere impact and penetration into wet sand

    Science.gov (United States)

    Marston, J. O.; Vakarelski, I. U.; Thoroddsen, S. T.

    2012-08-01

    We present experimental results for the penetration of a solid sphere when released onto wet sand. We show, by measuring the final penetration depth, that the cohesion induced by the water can result in either a deeper or shallower penetration for a given release height compared to dry granular material. Thus the presence of water can either lubricate or stiffen the granular material. By assuming the shear rate is proportional to the impact velocity and using the depth-averaged stopping force in calculating the shear stress, we derive effective viscosities for the wet granular materials.

  14. Sphere impact and penetration into wet sand

    KAUST Repository

    Marston, J. O.

    2012-08-07

    We present experimental results for the penetration of a solid sphere when released onto wet sand. We show, by measuring the final penetration depth, that the cohesion induced by the water can result in either a deeper or shallower penetration for a given release height compared to dry granular material. Thus the presence of water can either lubricate or stiffen the granular material. By assuming the shear rate is proportional to the impact velocity and using the depth-averaged stopping force in calculating the shear stress, we derive effective viscosities for the wet granular materials.

  15. Permeability Tests on Silkeborg Sand No. 0000

    DEFF Research Database (Denmark)

    Lund, Willy; Jakobsen, Kim Parsberg

    The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends on the charact......The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends...... on the characteristics of the soil matrix, the permeability is determined for different void ratios. All tests are performed on reconstituted specimens of Silkeborg Sand No. 0000. The permeability is determined by use of a falling head apparatus. The apparatus, test procedures and the analysis method are described...... in the succeeding sections. Finally the test results are briefly summarised and a relationship between void ratio l and permeability is established....

  16. Influence of different disinfecting modes on disinfection efficiency of outlet water from sand filter%不同的消毒方式对砂滤池出水消毒效果的影响

    Institute of Scientific and Technical Information of China (English)

    李芳; 陆少鸣

    2013-01-01

    Using pilot test with the mid-positioning O3-biological activated carbon filter,influences of different disinfection methods on disinfection efficiency of outlet water from sand filter were researched by the detection and analysis of microorganism,micro aquatic animals,DBPs and AOC.The results showed that the effect of chlorine disinfection was slightly weaker than ozone disinfection combined chlorination in removing microorganisms and micro aquatic animals.For the disinfection by-production of halogenated hydrocarbon and chlorate,chlorine disinfection produced more than ozone disinfection combined chlorination,the bromated is on the same level,while the formaldehyde is the opposite.The average AOC of sand filter effluent with chlorination and with ozone disinfection combined chlorination is 75.93 μg acetic acid carbon/L and 101.23 μg acetic acid carbon/L,respectively.The latter is more than 100 μg acetic acid carbon/L,which is unbeneficial for the biology stability of water distribution system.%采用中置O3-BAC工艺进行中试实验,通过对微生物、微型生物、消毒副产物和AOC进行检测分析,研究了不同的消毒方式对砂滤池出水消毒效果的影响.结果表明,氯消毒对微型生物、微生物的去除效果稍弱于臭氧联合氯消毒;对于消毒副产物而言,氯消毒产生的卤代烃、氯酸盐的含量高于臭氧联合氯消毒,产生的溴酸盐两者处于同一水平,而产生的甲醛则是氯消毒低于臭氧联合氯消毒;氯消毒最终砂滤池出水AOC平均含量75.93 μg乙酸碳/L,臭氧联合氯消毒为101.23μg乙酸碳/L,大于100 μg乙酸碳/L,不利于供水管网的生物稳定性.

  17. Regeneration of dredged sand waves

    NARCIS (Netherlands)

    Hulscher, Suzanne J.M.H.; Knaapen, Michiel; Scholl, Olaf; Scholl, O.; Trenteseaux., A.; Garlan, T.

    2000-01-01

    Sand waves form a wavy pattern in the offshore sandy seabed. Since their crests reduce the navigability, it is important to know their evolution. A simple model is presented to estimate the recovery of sand wave amplitudes. This model is partially based on the similarity with sea ripples and

  18. Namibia : triaxial test on sand

    DEFF Research Database (Denmark)

    Steenfelt, Jørgen S.; Jacobsen, Kim P.

    In connection with a harbour project the friction angle of a fine sand is required. On Friday 13 March 1998 the Danish Geotechnical Institute (DGI) delivered app. 2.5 kg sand for testing at the Geotechnical Engineering Laboratory, Aalborg University. The present Data Report summarises the results...

  19. Sand swimming lizard: sandfish

    CERN Document Server

    Maladen, Ryan D; Kamor, Adam; Goldman, Daniel I

    2009-01-01

    We use high-speed x-ray imaging to reveal how a small (~10cm) desert dwelling lizard, the sandfish (Scincus scincus), swims within a granular medium [1]. On the surface, the lizard uses a standard diagonal gait, but once below the surface, the organism no longer uses limbs for propulsion. Instead it propagates a large amplitude single period sinusoidal traveling wave down its body and tail to propel itself at speeds up to ~1.5 body-length/sec. Motivated by these experiments we study a numerical model of the sandfish as it swims within a validated soft sphere Molecular Dynamics granular media simulation. We use this model as a tool to understand dynamics like flow fields and forces generated as the animal swims within the granular media. [1] Maladen, R.D. and Ding, Y. and Li, C. and Goldman, D.I., Undulatory Swimming in Sand: Subsurface Locomotion of the Sandfish Lizard, Science, 325, 314, 2009

  20. Analysis of the environmental control technology for tar sand development

    Energy Technology Data Exchange (ETDEWEB)

    de Nevers, N.; Glenne, B.; Bryner, C.

    1979-06-01

    The environmental technology for control of air pollution, water pollution, and for the disposal, stabilization, and vegetation of the waste tar sand were thoroughly investigated. Although some difficulties may be encountered in any of these undertakings, it seems clear that the air and water pollution problems can be solved to meet any applicable standard. Currently there are two large-scale plants producing liquid fuels from tar sands in Alberta, Canada which use similar technology involving surface mining, hot water extraction, and surface disposal of waste sand. These projects all meet the Canadian environmental control regulations in force at the time they began. The largest US deposits of tar sands are much smaller than the Canadian; 95 percent are located in the state of Utah. Their economics do not appear as attractive as the Canadian deposits. The environmental control costs are not large enough to make an otherwise economic project uneconomic. The most serious environmental conflict likely to occur over the recovery of liquid fuels from the US deposits of tar sands is that caused by the proximity of the deposits to national parks, national monuments, and a national recreation area in Utah. These areas have very stringent air pollution requirements; and even if the air pollution control requirements can be met, there may still be adequate opposition to large-scale mining ventures in these areas to prevent their commercial exploitation. Another environmental constraint may be water rights availability.Essentially all of the water running in the Colorado river basin is now legally allocated. Barring new interpretations of the legality of water rights purchase, Utah tar sands developments should be able to obtain water by purchasing existing irrigation water rights.

  1. Bioaugmentation of flow-through sand filters

    DEFF Research Database (Denmark)

    Samuelsen, Elin Djurhuus

    Global applications of pesticides in agricultural production have led to the detection of trace amounts of pesticides in groundwater resources in levels exceeding the EU threshold limit for drinking water of 0.1 µg L-1. Pesticide-polluted groundwater may be remediated by inoculating waterworks sand...... filters with specific degrading bacteria. However, degradation efficiency is often hampered by poor adhesion and a lack of sustained catabolic activity of the introduced bacteria. The overall objective of this thesis was to investigate the significance of selected bacterial surface properties...... coincided with efficient mineralisation/degradation, and proposed the tfdC gene as a suitable marker for monitoring phenoxy acid degradation in strain PM2. Furthermore, when testing strain PM2s degradation performance in flow-through sand columns, we found that strain PM2 was able to sustain induced...

  2. Changes in composition and pore space of sand rocks in the oil water contact zone (section YU1 3-4, Klyuchevskaya area, Tomsk region)

    Science.gov (United States)

    Nedolivko, N.; Perevertailo, T.; Pavlovec, T.

    2016-09-01

    The article provides an analysis of specific features in changes of rocks in the oil water contact zone. The object of study is the formation YU1 3-4 (J3o1) of Klyuchevskaya oil deposit (West Siberian oil-gas province, Tomsk region). The research data allow the authors to determine vertical zoning of the surface structure and identify the following zones: oil saturation (weak alteration), bitumen-content dissolution, non-bitumen-content dissolution, cementation, including rocks not affected by hydrocarbon deposit. The rocks under investigation are characterized by different changes in composition, pore space, as well as reservoir filtration and volumetric parameters. Detection of irregularity in distribution of void- pore space in oil-water contact zones is of great practical importance. It helps to avoid the errors in differential pressure drawdown and explain the origin of low-resistivity collectors.

  3. The extraction of bitumen from western oil sands. Quarterly report, April--June 1993

    Energy Technology Data Exchange (ETDEWEB)

    Oblad, A.G.; Bunger, J.W.; Deo, M.D.; Fletcher, J.V.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1993-07-01

    Accomplishments are briefly described for the following tasks: environmental impact statement; coupled fluidized bed bitumen recovery and coked sand combustion; water-based recovery of bitumen; rotary kiln process for recovery of bitumen and combustion of coke sand; recovery of bitumen from oil sands using fluidized bed reactors and combustion of spent sands in transport reactors; recovery of bitumen from oil sand and upgrading of bitumen by solvent extraction; catalytic and thermal upgrading of bitumens and bitumen-derived liquids; evaluation of Utah`s major oil sand deposits for the production of asphalt, high energy jet fuels and other specialty products; development of mathematical models for bitumen recovery and processing; completion of the cost examination study of the pilot plant restoration; development studies of equipment for three-product gravity separation of bitumen and sand; determine thickener requirements; and environmental studies of the North Salt Lake pilot plant rehabilitation and eventual operation and those environmental problems associated with eventual commercial products.

  4. The influence of sanding system on wetting of Paulownia siebold et zucc.

    Directory of Open Access Journals (Sweden)

    Jaić Milan

    2010-01-01

    Full Text Available This paper presents the research of influence of wood surface preparation on the wetting ability of polyurethane coatings, by the method of contact angle. The samples were made of two species of Paulownia (Paulownia elongata and Paulownia fortunei. All the samples were processed by planing (molding. After molding, the samples were arranged in groups and sanded. In relation with wood grain direction, each group had a particular system of sanding, based on the numbering of sanding paper, program of displacement of sanding papers with different numbering and the direction of sanding. The quality of wood surface after sanding was expressed by the values of roughness parameters in the system 'M': Ra, Rz, Rv, Rp and Rt. The contact angle was measured using transparent polyurethane (PU coating and distilled water. The influence of the system of sanding on the values of contact angle was analyzed by roughness parameter Ra.

  5. Adsorption of Dyes Using Different Types of Sand: A Review

    African Journals Online (AJOL)

    NICO

    Sand is mixed with cement and water to make concrete, used in the manufacture of brick, glass .... powdered foods, or to absorb water in hygroscopic applications. ...... 37 M.B. Hasan, Adsorption of Reactive Azo Dyes on Chitosan/Oil Palm Ash.

  6. Occurrence of Radium-224, Radium-226 and Radium-228 in Water from the Vincentown and Wenonah-Mount Laurel Aquifers, the Englishtown Aquifer System, and the Hornerstown and Red Bank Sands, Southwestern and South-Central New Jersey

    Science.gov (United States)

    dePaul, Vincent T.; Szabo, Zoltan

    2007-01-01

    This investigation is the first regionally focused study of the presence of natural radioactivity in water from the Vincentown and Wenonah-Mount Laurel aquifers, Englishtown aquifer system, and the Hornerstown and Red Bank Sands. Geologic materials composing the Vincentown and Wenonah-Mount Laurel aquifers and the Hornerstown and Red Bank Sands previously have been reported to contain radioactive (uranium-enriched) phosphatic strata, which is common in deposits from some moderate-depth coastal marine environments. The decay of uranium and thorium gives rise to natural radioactivity and numerous radioactive progeny, including isotopes of radium. Naturally occurring radioactive isotopes, especially those of radium, are of concern because radium is a known human carcinogen and ingestion (especially in water used for drinking) can present appreciable health risks. A regional network in southwestern and south-central New Jersey of 39 wells completed in the Vincentown and Wenonah-Mount Laurel aquifers, the Englishtown aquifer system, and the Hornerstown and Red Bank Sands was sampled for determination of gross alpha-particle activity; concentrations of radium radionuclides, major ions, and selected trace elements; and physical properties. Concentrations of radium-224, radium-226, and radium-228 were determined for water from 28 of the 39 wells, whereas gross alpha-particle activity was determined for all 39. The alpha spectroscopic technique was used to determine concentrations of radium-224, which ranged from less than 0.5 to 2.7 pCi/L with a median concentration of less than 0.5pCi/L, and of radium-226, which ranged from less than 0.5 to 3.2 pCi/L with a median concentration of less than 0.5 pCi/L. The beta-counting technique was used to determine concentrations of radium-228. The concentration of radium-228 ranged from less than 0.5 to 4.3 pCi/L with a median of less than 0.5. Radium-228, when quantifiable, had the greatest concentration of the three radium

  7. Experimental Measurement of Diffusive Extinction Depth and Soil Moisture Gradients in Southwestern Saudi Arabian Dune Sand

    KAUST Repository

    Mughal, Iqra

    2013-05-01

    In arid lands, a major contribution to water loss is by soil water evaporation. Desert sand dunes in arid regions are devoid of runoff and have high rates of infiltration. Rainwater is commonly stored within them because of the low permeability soils in the underlying desert pavement. In such cases, moisture is confined in the sand dune below a depth, termed as the “extinction depth”, where it is protected from evaporation during long dry periods. Moreover, desert sand dunes have sparse vegetation, which results in low transpiration losses from the stored water. The water accumulated below the extinction depth of the sand dunes can be utilized for various purposes such as in irrigation to support desert agriculture. In this study, field experiments were conducted in Western Saudi Arabia to monitor the soil moisture gradients and determine the diffusive extinction depth of dune sand. The dune sand was saturated with water and was exposed to natural conditions (evaporation and precipitation). The decline of the water level in the sand column was continuously recorded using transducers and sensors installed at different depths monitored the temporal variation of temperature and moisture content within the sand. The hydrological simulator HYDRUS-1D was used to construct the vertical profiles of soil water content and temperature and the results obtained from HYDRUS-1D were compared to the gradients monitored by the sensors.

  8. Dissolution and time-dependent compaction of albite sand: experiments at 100°C and 160°C in pH-buffered organic acids and distilled water

    Science.gov (United States)

    Hajash, Andrew; Carpenter, Thomas D.; Dewers, Thomas A.

    1998-09-01

    Aqueous fluids are important in the diagenesis and deformation of crustal rocks. Both chemical and physical interactions are involved and often they are strongly coupled. For example, pore waters not only dissolve, transport, and precipitate chemical species, but they also substantially affect the mechanical behavior of the rocks that contain them. Stresses magnified at grain contacts by differences in pore-fluid pressure ( Pp) and confining pressure ( Pc) can, in turn, influence the rate and extent of chemical exchange. To begin investigation of these coupled systems, compaction experiments were conducted using albite sand (250-500 μm) and distilled water (pH 5.8), 0.07 M acetate (pH 4.7), and 0.07 M acetate + 0.005 M citrate (pH 4.4) solutions in a hydrothermal flow-through system at conditions that simulate diagenesis. Pore-fluid chemistry and pore-volume loss were monitored to quantify the effects of organic acids on time-dependent compaction rates. The effects of stress and fluid chemistry on the dissolution kinetics were also examined. Albite dissolution rates, monitored by steady-state fluid chemistry, increased when an effective pressure ( Pe= Pc- Pp) was applied, probably due to increases in total surface area caused by grain breakage at contacts. These effects were transient in distilled water, however, Si and Al concentrations remained elevated in the acetate pore fluid. The average Si-based release rates indicate ≈35% increase in reactive surface area by application of Pe=34.5 MPa. At 100°C with Pe=34.5 MPa, steady-state Si concentrations were ≈2.3 times higher in 0.07 M acetate and 5.8 times higher in 0.07 M acetate + 0.005 M citrate than in distilled water. Al increased by even larger factors (3× in the acetate buffer and 10× in the citrate solution). These changes in fluid chemistry are attributed to both pH and ligand-enhanced reactions. Albite dissolution appears to be controlled by surface complexation reactions at Al sites. Rapid

  9. Suspension mechanism and application of sand-suspended slurry for coalmine fire prevention

    Institute of Scientific and Technical Information of China (English)

    Xu Yongliang; Wang Lanyun; Chu Tingxiang; Liang Donglin

    2014-01-01

    North and west China has abundant coal resources, however, such resources make these regions prone to serious mine fire disasters. Although the copious sand and fly ash resources found in these areas can be used as fire-fighting materials, conventional grouting is expensive because of water shortage and loess particles. A new compound material (i.e., a sand-suspended colloid), which comprises a mineral inorganic gel and an organic polymer, is developed in the current study to improve the quality of sand injection and reduce water wastage when grouting. The new material can steadily suspend the sand, through the addi-tion of a small amount of colloid yielding steady sand-suspended slurry. The process of producing the slurry is convenient and quick, overcoming the shortage of sand-suspending thickeners which need heat and are difficult to produce. The space work model based on the theory of the double-electric layer is established to study the suspended mechanism of the solid particles in the sand-suspended colloid. The dispersion effect of the sand-suspended colloid is demonstrated by the incorporation of the electro-static effect by the double-electric layer and the steric hindrance effect on the sand particles, ensuring the stability of the colloid system and the steady suspension of sand particles in the sand-suspended colloid. Mechanical analysis indicates that the sand is suspended steadily under the condition that the rock sand particles stress on the lower part of the fluid is less than the yield stress of the colloid. Finally, the fire-prevention technology of sand suspension was applied and tested in the Daliuta Coal Mine, achieving suc-cessful results.

  10. 深水急流软弱砂层中超长钢板桩围堰施工技术%Super-long Steel Sheet Pile Cofferdam Construction Technology in Deep Water Jet Soft Sand

    Institute of Scientific and Technical Information of China (English)

    王西忠

    2014-01-01

    以兰永项目孔家寺黄河特大桥主桥深水承台基础的成功修建为背景,介绍了24m长钢板桩在深水急流软弱砂层条件下的施工工艺。该方法具有施工简单、快捷、成本较低等特点,可为同类施工环境下深水基础钢板桩围堰方案设计和施工提供借鉴。%Taking the successful construction of the main bridge deepwater pile caps foundation of Lanyong project Kongjiasi Yellow River grand bridge as the background, this paper introduces the construction technology of the 24m long steel sheet pile in deep water jet under the condition of weak sand. The method has features of simple construction, quickness, low cost and so on, which can provide reference for the design and construction of deepwater foundation steel sheet pile cofferdam scheme under similar construction environment.

  11. PERFORMANCE EVALUATION OF SAND AND CHITOSAN AS DUAL FILTER MEDIA

    Directory of Open Access Journals (Sweden)

    MADHUKAR M

    2012-01-01

    Full Text Available Nuisance due to suspended and colloidal particles causing turbidity has become widespread, severe problem due to urban population and industrial activities. The consequences of turbidity are presence of microorganisms,reduction of dissolved oxygen, etc. Consumption of such water is known to cause water borne diseases.Available water treatment methods for the removal of turbidity and pathogens are coagulation, filtration and disinfection. The common filter media used are sand, activated carbon etc. Chitosan has been used as acoagulant aid and adsorbent. Chitosan when used as a filter media causes the colloidal particles to bind together and is subsequently removed during the process. The column studies using Chitosan in combination with conventional sand filter was carried out in a borosilicate glass column. Chitosan was placed on top of sand layerand constant down flow pattern of 100mL/min was followed. Dual filter media was effective in the reducing turbidity by 93%.

  12. Linear sand ridges on the outer shelf of the East China Sea

    Institute of Scientific and Technical Information of China (English)

    WU Ziyin; JIN Xianglong; LI Jiabiao; ZHENG Yulong; WANG Xiaobo

    2005-01-01

    Based on the latest full-coverage high-resolu- tion multi-beam sounding data, the distribution of the linear sand ridges on the outer shelf of the East China Sea (ECS) is studied with quantitative statistical analysis. The study area can be divided into the northeastern part and the southwestern part. Sand ridges in the northeastern area, trending 116°N, show obvious linear character and shrink to the inner shelf. Sand ridges in the southwestern area, trending 120°N-146°N, tend to have net form. Sand ridges gradually become sand sheets in the center part of study area. Sand ridges are distributed landward to the isobath of 60m, distributed seaward to the water depth of 120 m in the northeast and 150 m in the southwest. Immature sand ridges are observed at water depth of 130-180 m in the southwestern depressions. The acoustic reflection properties of the internal high-angle inclined beddings of the sand ridges are analyzed based on the typical seismic profiles close to the research area. Lithological analysis and dating of 4 boreholes and 12 cores indicate that the widely distributed transgressive sand layer with high content of shell debris which was formed in the early-middle Holocene is the main composition of the linear sand ridges on the outer shelf of the ECS. The dominating factor in formation, developing and burying of the sand ridges is the variation of water depth caused by sea- level change and the rate of sediment supply. In 12400 aBP the cotidal lines of the M2 tidal component were closely perpendicular to the strike-directions of the sand ridges in the study area, and the tidal wave system during 12000-8000 aBP might play a key role in the formation of the linear sand ridges which are widely distributed on the outer shelf of the ECS.

  13. Assessment of Enterococcus Levels in Recreational Beach Sand Along the Rhode Island Coast.

    Science.gov (United States)

    Coakley, Eugenie; Parris, Amie L; Wyman, Al; Latowsky, Gretchen

    2016-04-01

    Recent studies have shown that coastal beach sand as well as coastal ocean water can be contaminated with fecal indicator Enterococcus bacteria (ENT). A study of sand ENT concentrations over a four-week period at 12 Rhode Island beaches was conducted during the summer of 2009. While average contamination was low relative to water quality standards, every beach had at least one day with very high sand ENT readings. On 10 of the 12 beaches, a statistically significant gradient occurred in geometric mean ENT concentrations among tidal zones, with dry (supratidal, or above high tide mark) sand having the highest level, followed by wet (intratidal, or below high tide mark) and underwater sand. Beaches with higher wave action had significantly lower ENT levels in wet and underwater sand compared to beaches with lower wave action.

  14. FLOW FIELD CHARACTERISTICS OF THE SAND FUNNEL AND ITS ME-CHANICS OF SEDIMENT TRANSPORT

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The flow in funnel chamber is typical three-di-mensional flow. The experimental results of clear water flowfield and muddy water flow field show that the flow character-istics in the funnel chamber are favorable to the separation ofwater and sand. Tangential velocity sustains the vortexstrength of the funnel chamber, axial velocity is benefit to thesediment sinking, and radial velocity is benefit to sedimentmoving to desilting hole. So the sand funnel is successful insediment disposal. The sand funnel projection has also gooddesilting effectiveness in practice. Its average flushing dis-charge is 3% of inlet canal discharge, the sand disposal rate is100% for the sand with grain diameter of more than 0. 5mm,and is more than 90% for the sand with grain diameter of lessthan 0. 5mm.

  15. The Rheology of Acoustically Fluidized Sand

    Science.gov (United States)

    Conrad, J. W.; Melosh, J.

    2013-12-01

    The collapse of large craters and the formation of central peaks and peak rings is well modeled by numerical computer codes that incorporate the acoustic fluidization mechanism to temporarily allow the fluid-like flow of rock debris immediately after crater excavation. Furthermore, long runout landslides require a similar mechanism to explain their almost frictionless movement, which is probably also a consequence of their granular composition coupled with internal vibrations. Many different investigators have now confirmed the ability of vibrations to fluidize granular materials. Yet it still remains to fully describe the rheology of vibrated sand as a function of stress, frequency and amplitude of the vibrations in the sand itself. We constructed a rotational viscometer to quantitatively investigate the relation between the stress and strain rate in a horizontal bed of strongly vibrated sand. In addition to the macroscopic stain rate, the amplitude and frequency of the vibrations produced by a pair of pneumatic vibrators were also measured with the aid of miniaturized piezoelectric accelerometers (B&K 4393) whose output was recorded on a digital storage oscilloscope. The initial gathering of the experimental data was difficult due to granular memory, but by having the sand compacted vibrationally for 8 minutes before each run the scatter of data was reduced and we were able to obtain consistent results. Nevertheless, our major source of uncertainty was variations in strain rate from run to run. We find that vibrated sand flows like a highly non-Newtonian fluid, in which the shear strain rate is proportional to stress to a power much greater than one, where the precise power depends on the amplitude and frequency of the applied vibrations. Rapid flow occurs at stresses less than half of the static yield stress (that is, the yield stress when no vibration is applied) when strong vibrations are present. For a Newtonian fluid, such as water, the relation between

  16. Sand engine quells the coast's hunger for sand

    NARCIS (Netherlands)

    Van Dijk, T.

    2012-01-01

    An artificial peninsula at Ter Heijde is designed to feed the coast with sediment. Scientists are investigating whether this kind of sand engine could be the Netherlands’ answer to rising sea levels.

  17. Sand engine quells the coast's hunger for sand

    NARCIS (Netherlands)

    Van Dijk, T.

    2012-01-01

    An artificial peninsula at Ter Heijde is designed to feed the coast with sediment. Scientists are investigating whether this kind of sand engine could be the Netherlands’ answer to rising sea levels.

  18. Spectroscopic characterization of a Nigerian standard sand: Igbokoda sand

    CSIR Research Space (South Africa)

    Ojuri, OO

    2017-01-01

    Full Text Available the Middle Ordovician St. Peter Sandstone near Ottawa, Illinois, had been picked by the American Society for Testing and Materials (ASTM) as the reference sand to employ in testing cement and strength of concrete [9]. To the best of our knowledge... and magnetic resonance spectroscopic techniques due to its importance in cement, geotechnical/geo-environmental research in Nigeria. This should halt importation of standard silica sand for mortar and concrete testing...

  19. The efficiency of sand filters for the treatment of drinking water. A case study; Studio sull'efficienza di filtri a sabbia per la potabilizzazione dell'acqua

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, M.; Marrale, D.; Fabiano, M. [Genoa Univ., Genoa (Italy). Dipt. per lo Studio del Territorio e delle sue Risorse; Palumbo, F. [Servizi Tecnologici e Ambientali SpA, Genoa (Italy)

    2001-10-01

    The efficiency of a drinking water treatment plant was investigated through the study of biochemical and microbial measures of the sand filter and the structure of the meiobenthic community. Filter and water samples were taken monthly and according to the different operation time. The efficiency of the biofilm was evaluated by the study of both structural (i.e. organic load before and after filtration, bacterial and meiobenthic density) and functional parameters (i.e. bacterial enzymatic activity and Frequency of Dividing Cells) and the analysis of the particulate organic material. The filters showed a high bacterial density and metabolic activity. The meiobenthic community, composed mainly by rotifers, nematodes and copepods, displayed a high degree of biodiversity during the studied period. The informative value of all the considered parameters and the efficiency of the filter during the operating period are discussed. [Italian] In un impianto di potabilizzazione delle acque l'analisi quali-quantitativa delle caratteristiche biochimiche e microbiche di un filtro a sabbia e del comparto acquatico associato ha permesso di valutare l'efficienza del sistema filtrante. I prelievi sono stati effettuati mensilmente in corrispondenza di differenti momenti operativi del filtro. Sono stati presi in considerazione aspetti funzionali, quali le attivita' idrolitica e duplicativa della comunita' batterica, e descrittivi (carico organico pre- e post-filtrazione, densita' batteriche e meiobentoniche). La valutazione relativa al materiale organico sospeso ha permesso di stimare l'efficienza di abbattimento attuata dal biofilm. I filtri presentano densita' batteriche molto elevate ed attivamente metabolizzanti. La comunita' meiobentonica, dominata da rotiferi, nematodi e copepodi, e' pero' sempre caratterizzata da un grado elevato di biodiversita'. Viene infine discusso il valore informativo dei diversi parametri e indici

  20. Saltation of Non-Spherical Sand Particles

    Science.gov (United States)

    Wang, Zhengshi; Ren, Shan; Huang, Ning

    2014-01-01

    Saltation is an important geological process and the primary source of atmospheric mineral dust aerosols. Unfortunately, no studies to date have been able to precisely reproduce the saltation process because of the simplified theoretical models used. For example, sand particles in most of the existing wind sand movement models are considered to be spherical, the effects of the sand shape on the structure of the wind sand flow are rarely studied, and the effect of mid-air collision is usually neglected. In fact, sand grains are rarely round in natural environments. In this paper, we first analyzed the drag coefficients, drag forces, and starting friction wind speeds of sand grains with different shapes in the saltation process, then established a sand saltation model that considers the coupling effect between wind and the sand grains, the effect of the mid-air collision of sand grains, and the effect of the sand grain shape. Based on this model, the saltation process and sand transport rate of non-spherical sand particles were simulated. The results show that the sand shape has a significant impact on the saltation process; for the same wind speed, the sand transport rates varied for different shapes of sand grains by as much as several-fold. Therefore, sand shape is one of the important factors affecting wind-sand movement. PMID:25170614

  1. The bituminous sands : a Canadian mirage?

    Energy Technology Data Exchange (ETDEWEB)

    Rousse, D.R. [Quebec Univ., Chicoutimi, PQ (Canada). Dept. des Sciences Appliquees; Nasr, G.J. [Lebanese Univ., Roumieh (Lebanon). Faculty of Engineering; Turcotte, S.F. [Quebec Univ., Montreal, PQ (Canada). Centre d' Etudes Internationales et Mondialisation; Salah, N.B. [Ecole Superieure des Sciences et Techniques De Tunis, Tunis (Tunisia). LMMP

    2009-07-01

    This paper examined the controversy about the potential role of a significant increase in Canadian oil sands production in order to bridge the upcoming gap between the world's increasing energy demand and the total recoverable oil supply. The paper presented the actual potential of different scenarios and considered the prediction cost forecasts. A brief overview of environmental impacts and the real return on investments were also provided. Environmental impacts that were considered included land degradation; water contamination; ecosystem damage; and air pollution. Nuclear energy was also presented as a possible solution. The paper demonstrated that even in a very optimistic scenario, Canada's oil sands accelerated production has a negligible effect on the aforementioned gap, has a considerable impact on environment that has yet to be accounted for. Energy ratios that were presented included energy return on energy investment; energy available on energy used; and energy payback. It was concluded that enhanced recovery techniques are clearly needed for future sustainable exploitation of these bituminous sands. 32 refs., 1 fig.

  2. Reclaimability of the spent sand mixture – sand with bentonite – sand with furfuryl resin

    Directory of Open Access Journals (Sweden)

    J. Dańko

    2011-04-01

    Full Text Available Introduction of new binding materials and new technologies of their hardening in casting moulds and cores production requires theapplication of reclamation methods adequate to their properties as well as special devices realizing tasks. The spent sands circulationsystem containing the same kind of moulding and core sands is optimal from the point of view of the expected reclamation results.However, in the face of a significant variability of applied technologies and related to them various reclamation methods, the need - of theobtained reclamation products assessment on the grounds of systematic criteria and uniform bases – arises, with a tendency of indicatingwhich criteria are the most important for the given sand system. The reclaimability results of the mixture of the spent moulding sand withGeko S bentonite and the spent core sand with the Kaltharz 404U resin hardened by acidic hardener 100 T3, are presented in the paper.Investigations were performed with regard to the estimation of an influence of core sands additions (10 –25% on the reclaimed materialquality. Dusts and clay content in the reclaim, its chemical reaction (pH and ignition loss were estimated. The verification of the reclaiminstrumental assessment was performed on the basis of the technological properties estimation of moulding sand with bentonite, where the reclaimed material was used as a matrix.

  3. Biocarriers Improve Bioaugmentation Efficiency of a Rapid Sand Filter for the Treatment of 2,6-Dichlorobenzamide-Contaminated Drinking Water.

    Science.gov (United States)

    Horemans, Benjamin; Raes, Bart; Vandermaesen, Johanna; Simanjuntak, Yanti; Brocatus, Hannelore; T'Syen, Jeroen; Degryse, Julie; Boonen, Jos; Wittebol, Janneke; Lapanje, Ales; Sørensen, Sebastian R; Springael, Dirk

    2017-02-07

    Aminobacter sp. MSH1 immobilized in an alginate matrix in porous stones was tested in a pilot system as an alternative inoculation strategy to the use of free suspended cells for biological removal of micropollutant concentrations of 2,6-dichlorobenzamide (BAM) in drinking water treatment plants (DWTPs). BAM removal rates and MSH1 cell numbers were recorded during operation and assessed with specific BAM degradation rates obtained in lab conditions using either freshly grown cells or starved cells to explain reactor performance. Both reactors inoculated with either suspended or immobilized cells showed immediate BAM removal under the threshold of 0.1 μg/L, but the duration of sufficient BAM removal was 2-fold (44 days) longer for immobilized cells. The longer sufficient BAM removal in case of immobilized cells compared to suspended cells was mainly explained by a lower initial loss of MSH1 cells at operational start due to volume replacement and shear. Overall loss of activity in the reactors though was due to starvation, and final removal rates did not differ between reactors inoculated with immobilized and suspended cells. Management of assimilable organic carbon, in addition to cell immobilization, appears crucial for guaranteeing long-term BAM degradation activity of MSH1 in DWTP units.

  4. Management recommendations: Sand Lake Complex

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a review of land management practices at the Sand Lake National Wildlife Refuge, by a land use specialist. Recommendations, time frame and...

  5. Experimental and numerical study on thermal conductivity of partially saturated unconsolidated sands

    Science.gov (United States)

    Lee, Youngmin; Keehm, Youngseuk; Kim, Seong-Kyun; Shin, Sang Ho

    2016-04-01

    A class of problems in heat flow applications requires an understanding of how water saturation affects thermal conductivity in the shallow subsurface. We conducted a series of experiments using a sand box to evaluate thermal conductivity (TC) of partially saturated unconsolidated sands under varying water saturation (Sw). We first saturated sands fully with water and varied water saturation by drainage through the bottom of the sand box. Five water-content sensors were integrated vertically into the sand box to monitor water saturation changes and a needle probe was embedded to measure thermal conductivity of partially saturated sands. The experimental result showed that thermal conductivity decreases from 2.5 W/mK for fully saturated sands to 0.7 W/mK when water saturation is 5%. We found that the decreasing trend is quite non-linear: highly sensitive at very high and low water saturations. However, the boundary effects on the top and the bottom of the sand box seemed to be responsible for this high nonlinearity. We also found that the determination of water saturation is quite important: the saturation by averaging values from all five sensors and that from the sensor at the center position, showed quite different trends in the TC-Sw domain. In parallel, we conducted a pore-scale numerical modeling, which consists of the steady-state two-phase Lattice-Boltzmann simulator and FEM thermal conduction simulator on digital pore geometry of sand aggregation. The simulation results showed a monotonous decreasing trend, and are reasonably well matched with experimental data when using average water saturations. We concluded that thermal conductivity would decrease smoothly as water saturation decreases if we can exclude boundary effects. However, in dynamic conditions, i.e. imbibition or drainage, the thermal conductivity might show hysteresis, which can be investigated with pore-scale numerical modeling with unsteady-state two-phase flow simulators in our future work.

  6. Contribution to Improving the Performance of Concrete: The Case of the Use of Desert Sand of the Region of Dakar

    Directory of Open Access Journals (Sweden)

    A. Cisse

    2012-12-01

    Full Text Available Although the extraction of sea sand is not the only factor responsible for coastal erosion, it is an important phenomenon in the degradation of the coastal environment. For this reason, local authorities have banned the use of sea sand and also operators in the construction sector (Public Works and Water Resources should use the desert sand that is the only current alternative. Indeed, the alluvial sand usually has better features than the desert sand, but it is not available in sufficient reserves to the needs of the construction sector. The purpose of this study is to characterize (granularity, cleanliness some quarries of desert sand used in the Dakar region to verify the extent to which they are used in construction and more specifically in hydraulic concrete composition. Furthermore, a method of mixing improved this desert sand with crushed sand 0/3, from the rock crushing mass, is studied below.

  7. Synthesis, characterization and application of a novel chemical sand-fixing agent-poly(aspartic acid) and its composites

    Energy Technology Data Exchange (ETDEWEB)

    Yang Jun [Beijing Key Laboratory of Bioprocess, Beijing University of Chemical Technology, Beijing 100029 (China); Wang Fang [Beijing Key Laboratory of Bioprocess, Beijing University of Chemical Technology, Beijing 100029 (China); Fang Li [Beijing Key Laboratory of Bioprocess, Beijing University of Chemical Technology, Beijing 100029 (China); Tan Tianwei [Beijing Key Laboratory of Bioprocess, Beijing University of Chemical Technology, Beijing 100029 (China)]. E-mail: twtan@mail.buct.edu.cn

    2007-09-15

    A novel sand-fixing agent-poly(aspartic acid) and its composites were synthesized to improve sand particles compressive strength and anti-wind erosion properties. The relationship between the concentration of sand-fixing agent and the sand-fixing properties was studied by three kinds of aging tests. Some composites were choose to improve the sand-fixing property and the composition of 40% xanthan gum and 60% ethyl cellulose were chosen to compare sand-fixing property with lignosulfonate. The results showed that the sand-fixing and water-retaining properties of xanthan gum and ethyl cellulose composites were better than that of lignosulfonate. The biodegradability experiment showed that the PASP and its composites were environment-friendly products and the field test showed that the PASP composites could improve wind erosion disturbance. - A novel biodegradability polymer significantly improved sand particles' compressive strength and anti-wind erosion properties.

  8. Geotechnical properties of cemented sands in steep slopes

    Science.gov (United States)

    Collins, B.D.; Sitar, N.

    2009-01-01

    An investigation into the geotechnical properties specific to assessing the stability of weakly and moderately cemented sand cliffs is presented. A case study from eroding coastal cliffs located in central California provides both the data and impetus for this study. Herein, weakly cemented sand is defined as having an unconfined compressive strength (UCS) of less than 100 kPa, and moderately cemented sand is defined as having UCS between 100 and 400 kPa. Testing shows that both materials fail in a brittle fashion and can be modeled effectively using linear Mohr-Coulomb strength parameters, although for weakly cemented sands, curvature of the failure envelope is more evident with decreasing friction and increasing cohesion at higher confinement. Triaxial tests performed to simulate the evolving stress state of an eroding cliff, using a reduction in confinement-type stress path, result in an order of magnitude decrease in strain at failure and a more brittle response. Tests aimed at examining the influence of wetting on steep slopes show that a 60% decrease in UCS, a 50% drop in cohesion, and 80% decrease in the tensile strength occurs in moderately cemented sand upon introduction to water. In weakly cemented sands, all compressive, cohesive, and tensile strength is lost upon wetting and saturation. The results indicate that particular attention must be given to the relative level of cementation, the effects of groundwater or surficial seepage, and the small-scale strain response when performing geotechnical slope stability analyses on these materials. ?? 2009 ASCE.

  9. Geology of the Athabasca oil sands

    Science.gov (United States)

    Mossop, G. D.

    1980-01-01

    In-place bitumen resources in the Alberta oil sands are estimated at 1350 billion barrels. Open-pit mining and hot water extraction methods, which involve the handling of huge tonnages of earth materials, are being employed in the two commercial plants now operating. In situ recovery methods will be required to tap the 90 percent of reserves that are too deeply buried to be surface mined. Development of in situ technologies will be painstaking and expensive, and success will hinge on their compatibility with extremely complex geological conditions in the subsurface.

  10. Continental shelf processes affecting the oceanography of the South Atlantic Bight. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Pietrafesa, L.J.

    1978-03-01

    The objectives of the project were to determine the physical/dynamical processes controlling/affecting the distribution of phytoplankton nutrients on the continental shelf in the South Atlantic Bight. The initial objectives were to determine the short term, i.e., 2 to 10 day and longer term flux of nutrients onto the continental shelf. This is clearly related to the more general problem of combined physical and biogenic control of phytoplankton nutrients. During the period from June, 1975 to March, 1978 the study of the continental shelf processes affecting the oceanography of the South Atlantic Bight has been principally involved with a substantial, coordinated field effort. The success of the data acquisition phase of the program has now required an intensive data analysis phase which has been slowly increasing in effort. Emphasis is placed on the main phase of the field program, located in Onslow Bay, which has beel completed and the data are being analyzed. During the three-year period 20 cruises were made into the Carolina Capes area and samples were collected. A list is included of some 100 publications during the period.

  11. Experimental investigation on heat transport in gravel-sand materials

    DEFF Research Database (Denmark)

    Maureschat, Gerald; Heller, Alfred

    1997-01-01

    out in a small size experiment. The experiment consists of a highly insulated box filled with two kinds of sand material crossed by a plastic heat pipe. Heat transfer is measured under dry and water satured conditions in a cross-section.The conclusions are clear. To obtain necessary heat conduction...... in sand-gravel material, the storage media is to be water satured. In this case, handling of such material on site is rather complex. The conduction is highly dependent on the thermal properties of the storage media and so is the overall thermal performance of a storage applying such media. For sandy...... media no convectional heat transport is found. It would be relevant to extend the investigation to media that enables convectional heat transport. A last conclusion is that such experiments, necessary for proper designing of sand-gravel storage types, are a very cheap form of collecting information...

  12. Enhanced microbubbles assisted cleaning of diesel contaminated sand.

    Science.gov (United States)

    Agarwal, Ashutosh; Liu, Yu

    2017-07-25

    In this article, we investigated the effect of low intensity pulsed ultrasound (US), temperature and salinity on cleaning efficacy of fine bubbles with diameter <50μm for diesel contaminated sands. About 47% and 76% diesel removal was achieved from 10% (w/w) diesel contaminated fine and medium sands respectively, after 30min treatment with 40kHz low intensity intermittent pulsed US together with MBs in contrast to 41% and 68% diesel removal while treatment with MBs alone. The effect of high temperature was found to be prominent during the initial stages of cleaning. In addition, MBs generated in 599mM saline water efficiently removed 85% diesel from fine sand within 30min in contrast to only 41% diesel removal with MBs in fresh water. This study provides evidence for developing highly efficient MBs based chemical free technology for diesel contaminated sediments. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Interaction forces in bitumen extraction from oil sands.

    Science.gov (United States)

    Liu, Jianjun; Xu, Zhenghe; Masliyah, Jacob

    2005-07-15

    Water-based extraction process (WBEP) has been successfully applied to bitumen recovery from Athabasca oil sand ore deposits in Alberta. In this process, two essential steps are involved. The bitumen first needs to be "liberated" from sand grains, followed by "aeration" with air bubbles. Bitumen "liberation" from the sand grains is controlled by the interaction between the bitumen and sand grains. Bitumen "aeration" is dependent, among other mechanical and hydrodynamic variables, on the hydrophobicity of the bitumen surface, which is controlled by water chemistry and interactions between bitumen and fine solids. In this paper, the interaction force measured with an atomic force microscope (AFM) between bitumen-bitumen, bitumen-silica, bitumen-clays and bitumen-fines is summarized. The measured interaction force barrier coupled with the contacted adhesion force allows us to predict the coagulative state of colloidal systems. Zeta potential distribution measurements, in terms of heterocoagulation, confirmed the prediction of the measured force profiles using AFM. The results show that solution pH and calcium addition can significantly affect the colloidal interactions of various components in oil sand extraction systems. The strong attachment of fines from a poor processing ore on bitumen is responsible for the corresponding low bitumen flotation recovery. The identification of the dominant non-contact forces by fitting with the classical DLVO or extended DLVO theory provides guidance for controlling the interaction behavior of the oil sand components through monitoring the factors that could affect the non-contact forces. The findings provide insights into megascale industrial operations of oil sand extraction.

  14. A novel wastewater cleaning system for the stone-crushing and sand-making process

    Institute of Scientific and Technical Information of China (English)

    Zhang Wenjun; Li Yanfeng; Tang Jie

    2012-01-01

    The nature of the slurry from the stone-crushing and sand-making processes is analyzed to develop a novel separation process.The process comprises hydro-cyclone separation followed by screening of the fines,clarification,and filtration.Recovering fine sand and clean wastewater for recycle is demonstrated.The +0.045 mm fine sand fraction and-0.045 mm ultra-fine clay in the slurry are separated and recovered.Fine sand that was previously lost and wasted is now recoverable.The cleaned and reused water is as much as 94% of the total.

  15. The extraction of bitumen from western oil sands: Volume 1. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Oblad, A.G.; Dahlstrom, D.A.; Deo, M.D.; Fletcher, J.V.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1997-11-26

    The program is composed of 20 projects, of which 17 are laboratory bench or laboratory pilot scale processes or computer process simulations that are performed in existing facilities on the University of Utah campus in north-east Salt Lake City. These tasks are: (1) coupled fluidized-bed bitumen recovery and coked sand combustion; (2) water-based recovery of bitumen; (3) oil sand pyrolysis in a continuous rotary kiln reactor; (4) oil sand pyrolysis in a large diameter fluidized bed reactor; (5) oil sand pyrolysis in a small diameter fluidized bed reactor; (6) combustion of spent sand in a transport reactor; (7) recovery and upgrading of oil sand bitumen using solvent extraction methods; (8) fixed-bed hydrotreating of Uinta Basin bitumens and bitumen-derived hydrocarbon liquids; (9) ebullieted bed hydrotreating of bitumen and bitumen derived liquids; (10) bitumen upgrading by hydropyrolysis; (11) evaluation of Utah`s major oil sand deposits for the production of asphalt, high-energy jet fuels and other specialty products; (12) characterization of the bitumens and reservoir rocks from the Uinta Basin oil sand deposits; (13) bitumen upgrading pilot plant recommendations; (14) liquid-solid separation and fine tailings thickening; (15) in-situ production of heavy oil from Uinta Basin oil sand deposits; (16) oil sand research and development group analytical facility; and (17) process economics. This volume contains an executive summary and reports for five of these projects. 137 figs., 49 tabs.

  16. The extraction of bitumen from western oil sands: Volume 2. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Oblad, A.G.; Dahlstrom, D.A.; Deo, M.D.; Fletcher, J.V.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1997-11-26

    The program is composed of 20 projects, of which 17 are laboratory bench or laboratory pilot scale processes or computer process simulations that are performed in existing facilities on the University of Utah campus in north-east Salt Lake City. These tasks are: (1) coupled fluidized-bed bitumen recovery and coked sand combustion; (2) water-based recovery of bitumen; (3) oil sand pyrolysis in a continuous rotary kiln reactor; (4) oil sand pyrolysis in a large diameter fluidized bed reactor; (5) oil sand pyrolysis in a small diameter fluidized bed reactor; (6) combustion of spent sand in a transport reactor; (7) recovery and upgrading of oil sand bitumen using solvent extraction methods; (8) fixed-bed hydrotreating of Uinta Basin bitumens and bitumen-derived hydrocarbon liquids; (9) ebullieted bed hydrotreating of bitumen and bitumen derived liquids; (10) bitumen upgrading by hydropyrolysis; (11) evaluation of Utah`s major oil sand deposits for the production of asphalt, high-energy jet fuels and other specialty products; (12) characterization of the bitumens and reservoir rocks from the Uinta Basin oil sand deposits; (13) bitumen upgrading pilot plant recommendations; (14) liquid-solid separation and fine tailings thickening; (15) in-situ production of heavy oil from Uinta Basin oil sand deposits; (16) oil sand research and development group analytical facility; and (17) process economics. This volume contains reports on nine of these projects, references, and a bibliography. 351 refs., 192 figs., 65 tabs.

  17. Woody plants in dry sands : life history traits and population dynamics

    NARCIS (Netherlands)

    Li, S.|info:eu-repo/dai/nl/304849324

    2010-01-01

    Inland dune ecosystems are harsh environment for long-lived woody plants because of poor water and nutrient availability and frequent sand. As a result, long-lived woody plants have a high risk of being killed by sand movement or a long period of drought and this may occur even before they reach rep

  18. Woody plants in dry sands : life history traits and population dynamics

    NARCIS (Netherlands)

    Li, S.

    2010-01-01

    Inland dune ecosystems are harsh environment for long-lived woody plants because of poor water and nutrient availability and frequent sand. As a result, long-lived woody plants have a high risk of being killed by sand movement or a long period of drought and this may occur even before they reach

  19. Modeling fine-scale geological heterogeneity-examples of sand lenses in tills

    DEFF Research Database (Denmark)

    Kessler, Timo Christian; Comunian, Alessandro; Oriani, Fabio;

    2013-01-01

    Sand lenses at various spatial scales are recognized to add heterogeneity to glacial sediments. They have high hydraulic conductivities relative to the surrounding till matrix and may affect the advective transport of water and contaminants in clayey till settings. Sand lenses were investigated o...

  20. Biodegradation of MIB and geosmin with slow sand filters.

    Science.gov (United States)

    Hsieh, Shu-Ting; Lin, Tsair-Fuh; Wang, Gen-Shuh

    2010-01-01

    This study evaluated the biodegradation of MIB (2-methylisoborneol) and geosmin (trans-1,10-dimethyl-trans- 9-decalol) in simulated slow sand filtration (SSF) columns and in batch reactors. The results showed that both MIB and geosmin were biodegradable in the two systems. In batch experiments, the overall removals for MIB and geosmin were 50% and 78%, respectively, after 7 days of contact time. Volatilization loss plays an important role for geosmin in batch systems. Simulated SSF column studies also showed that more than 50% of geosmin and MIB were degraded by the microbial on the sand surface of a slow sand filter. With a filtration rate of 5 m/day, the simulated SSF degraded MIB from 48% to 69% and geosmin from 87% to 96%. The rapid biodegradation of MIB and geosmin in SSF column tests was attributed to the use of filter sands from the SSF unit in the Kinmen water treatment plant, where the microbial had been acclimated to both MIB and geosmin. The results also showed that more than 70% of the geosmin was removed in the top portion of the filter ( approximately 10 cm); while the removal of MIB occurred throughout the entire column depth. The results of this study demonstrated that slow flow through preacclimated sand was effective for control of MIB and geosmin in drinking water.

  1. Present status of effect of microorganisms from sand beach on public health

    Directory of Open Access Journals (Sweden)

    Emmanuel Velonakis

    2014-09-01

    Full Text Available Microorganisms are significant components of beach sand. According to the research, all kind of microorganisms have been isolated from beach sand; certain genera and species are potential pathogens for humans and animals. In resort areas, especially during the summer, certain infections (e.g. gastroenteritis and dermatitis are usually related to polluted bathing water. Lately, the interest of scientists is also focused on the potential association of some of the above diseases with the beach sand. Relatively, recent epidemiological studies in the USA revealed positive correlation between time spent at the beach and gastroenteritis. New parameters such as wind blowing and beach users’ density are also introduced for discussion in association with the sand microbial load. Regarding the preventative measures, the microbiological quality of beach sand can be improved by raising the general level of hygiene, as well as by using simple methods, such as sweeping and aeration of the sand, together with constant beach supervision.

  2. Study on Strength of Concrete Using Robo Sand as a Partial Replacement of Fine Aggregate

    Directory of Open Access Journals (Sweden)

    S.Rukmangadhara Rao,

    2015-12-01

    Full Text Available Robo sand is one of the most used among such materials to replace river sand, which can be used as an alternative to fine aggregate in concrete. In the present investigation workability and strength of concrete was evaluated by replacement of natural sand by Robo sand in proportions of 0%, 50%, 75%, and 100% is studied for M25and M35grade concrete cubes, cylinders and prisms. Slump cone method is taken for finding workability. For strength parameters for each grade of concrete Cubes, Cylinders and Prisms were casted and tested at the age of 7 and 28 days. In this present experimental study on concrete having grades of M25 and M35 are prepared by replacing natural sand by Robo sand. Concrete specimens were tested for evaluation of compressive strength and water absorption.

  3. Present status of effect of microorganisms from sand beach on public health

    Institute of Scientific and Technical Information of China (English)

    Emmanuel Velonakis; Dimitra Dimitriadi; Emmanuel Papadogiannakis; Alkiviades Vatopoulos

    2014-01-01

    Microorganisms are significant components of beach sand. According to the research, all kind of microorganisms have been isolated from beach sand; certain genera and species are potential pathogens for humans and animals. In resort areas, especially during the summer, certain infections (e.g. gastroenteritis and dermatitis) are usually related to polluted bathing water. Lately, the interest of scientists is also focused on the potential association of some of the above diseases with the beach sand. Relatively, recent epidemiological studies in the USA revealed positive correlation between time spent at the beach and gastroenteritis. New parameters such as wind blowing and beach users’ density are also introduced for discussion in association with the sand microbial load. Regarding the preventative measures, the microbiological quality of beach sand can be improved by raising the general level of hygiene, as well as by using simple methods, such as sweeping and aeration of the sand, together with constant beach supervision.

  4. The extraction of bitumen from western oil sands. Quarterly report, July--September, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Oblad, A.G.; Bunger, J.W.; Dahlstrom, D.A.; Deo, M.D.; Fletcher, J.V.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1993-11-01

    This report cites task number followed by a brief statement of each task and the action taken this quarter. The tasks are: NEPA environmental information statement; coupled fluidized-bed bitumen recovery and coked sand combustion; water-based recovery of bitumen; rotary kiln process for recovery of bitumen and combustion of coke sand; recovery of bitumen from oil sands using fluidized bed reactors and combustion of spent sands in transport reactors; recovery of bitumen from oil sand and upgrading of bitumen by solvent extraction; catalytic and thermal upgrading of bitumens and bitumen-derived liquids; evaluation of Utah`s major oil sand deposits for the production of asphalt, high energy jet fuels, and other specialty products; development of mathematical models for bitumen recovery and processing; completion of the cost estimation study of the pilot plant restoration; development studies of equipment for three-product gravity separation of bitumen and sand; development studies of disposal of sand by conveying or pumping of high solids concentration sand-water slurries; and environmental studies of the North Salt Lake pilot plant rehabilitation and eventual operation and those environmental problems associated with eventual commercial products.

  5. Disturbance of the inclined inserting-type sand fence to wind-sand flow fields and its sand control characteristics

    Science.gov (United States)

    Cheng, Jian-jun; Lei, Jia-qiang; Li, Sheng-yu; Wang, Hai-feng

    2016-06-01

    The inclined inserting-type sand fence is a novel sand retaining wall adopted along the Lanxin High-Speed Railway II in Xinjiang for controlling and blocking sand movement. To verify the effectiveness of the new fence structure for sand prevention, a wind tunnel test was used for flow field test simulation of the sand fence. The results indicate that the inclined inserting-type sand fence was able to deflect the flow of the sand and was able to easily form an upward slant acceleration zone on the leeward side of the sand fence. As shown by the percentage change in sand collection rates on the windward side and the leeward side of the sand fence, the sand flux per unit area at 4 m height in the slant upward direction increased on the leeward side of the inclined inserting-type sand fence. By comparing the flow fields, this site is an acceleration zone, which also reaffirms the correspondence of wind-sand flow fields with the spatial distribution characteristic of the wind-carried sand motion. The field sand collection data indicates that under the effects of the inclined inserting-type sand fence, the sandy air currents passing in front and behind the sand fence not only changed in quality, but the grain composition and particle size also significantly changed, suggesting that the inclined inserting-type sand fence has a sorting and filtering effect on the sandy air currents that passed through. The fence retained coarse particulates on the windward side and fine particulates within the shade of the wind on the leeward side.

  6. Nanomorphology of Itokawa regolith particles: Application to space-weathering processes affecting the Itokawa asteroid

    Science.gov (United States)

    Matsumoto, Toru; Tsuchiyama, Akira; Uesugi, Kentaro; Nakano, Tsukasa; Uesugi, Masayuki; Matsuno, Junya; Nagano, Takashi; Shimada, Akira; Takeuchi, Akihisa; Suzuki, Yoshio; Nakamura, Tomoki; Nakamura, Michihiko; Gucsik, Arnold; Nagaki, Keita; Sakaiya, Tatsuhiro; Kondo, Tadashi

    2016-08-01

    The morphological properties of 26 regolith particles from asteroid Itokawa were observed using scanning electron microscopes in combination with an investigation of their three-dimensional shapes obtained through X-ray microtomography. Surface observations of a cross section of the LL5 chondrite, and of crystals of olivine and pyroxene, were also performed for comparison. Some Itokawa particles have surfaces corresponding to walls of microdruses in the LL chondrite, where concentric polygonal steps develop and euhedral or subhedral grains exist. These formed through vapor growth owing to thermal annealing, which might have been caused by thermal metamorphism or shock-induced heating in Itokawa's parent body. Most of the Itokawa particles have more or less fractured surfaces, indicating that they were formed by disaggregation, probably caused by impacts. Itokawa particles with angular and rounded edges observed in computed tomography images are associated with surfaces exhibiting clear and faint structures, respectively. These surfaces can be interpreted by invoking different degrees of abrasion after regolith formation. A possible mechanism for the abrasion process is grain migration caused by impact-driven seismic waves. Space-weathered rims with blisters are distributed heterogeneously across the Itokawa regolith particles. This heterogeneous distribution can be explained by particle motion and fracturing, combined with solar-wind irradiation of the particle surfaces. The regolith activity-including grain motion, fracturing, and abrasion-might effectively act as refreshing process of Itokawa particles against space-weathered rim formation. The space-weathering processes affecting Itokawa would have developed simultaneously with space-weathered rim formation and regolith particle refreshment.

  7. Optimal array of sand fences.

    Science.gov (United States)

    Lima, Izael A; Araújo, Ascânio D; Parteli, Eric J R; Andrade, José S; Herrmann, Hans J

    2017-03-24

    Sand fences are widely applied to prevent soil erosion by wind in areas affected by desertification. Sand fences also provide a way to reduce the emission rate of dust particles, which is triggered mainly by the impacts of wind-blown sand grains onto the soil and affects the Earth's climate. Many different types of fence have been designed and their effects on the sediment transport dynamics studied since many years. However, the search for the optimal array of fences has remained largely an empirical task. In order to achieve maximal soil protection using the minimal amount of fence material, a quantitative understanding of the flow profile over the relief encompassing the area to be protected including all employed fences is required. Here we use Computational Fluid Dynamics to calculate the average turbulent airflow through an array of fences as a function of the porosity, spacing and height of the fences. Specifically, we investigate the factors controlling the fraction of soil area over which the basal average wind shear velocity drops below the threshold for sand transport when the fences are applied. We introduce a cost function, given by the amount of material necessary to construct the fences. We find that, for typical sand-moving wind velocities, the optimal fence height (which minimizes this cost function) is around 50 cm, while using fences of height around 1.25 m leads to maximal cost.

  8. Monitoring of rapid sand filters using an acoustic imaging technique

    NARCIS (Netherlands)

    Allouche, N.; Simons, D.G.; Rietveld, L.C.

    2012-01-01

    A novel instrument is developed to acoustically image sand filters used for water treatment and monitor their performance. The instrument consists of an omnidirectional transmitter that generates a chirp with a frequency range between 10 and 110 kHz, and an array of hydrophones. The instrument was e

  9. Dependence of sand soil compressibility on soil physical properties

    Institute of Scientific and Technical Information of China (English)

    I.S.Vakhrin; G.P.Kuzmin

    2014-01-01

    A relationship between soil physical properties and its compressibility has been analyzed. The formulae to determine soil density and porosity have been substantiated in compression tests. The regularity of changes in compressibility of thawed sand soils with various degrees of water content has been experimentally identified.

  10. Holocene beach buildup and coastal aeolian sand incursions off the Nile littoral cell

    Science.gov (United States)

    Roskin, Joel; Sivan, Dorit; Shtienberg, Gilad; Porat, Naomi; Bookman, Revital

    2017-04-01

    Israel's coastal plain is abundant with sand originating from the Nile littoral cell. The inland windblown loose sand has formed 3-6 km wide lobe-like sand and dune fields currently comprised of foredunes, linear and northeasterly facing transverse and parabolic dunes that are currently stabilized by vegetation. This study reviews the architecture and history of the these dune fields aiming to: (a) Date the timings of beach accretion, and sand and dune incursions. (b) Discriminate between natural and human-induced forcing factors of sand mobilization and stabilization in time and space. (c) Present a model of the dunescape development. (d) Assess scenarios of sand transport in the future charcaterized by intense human impact and climate change. Luminescence ages, radiocarbon dates and relative ages from previously published geological and archaeological reports, historical texts, together with new optically stimulated luminescence (OSL) ages and stratigraphic and sedimentological data are analyzed. The deposition, mobilizations and preservation of the sand bodies, initially induced by the decline in sea level rise at 6-4 ka, were later controlled by historic land-use intensity and modern land-use/negligence practices. At 6 ka, beach sand buildup rapidly started. Where aeolianite ridges bordered the coast, pulses of sand with biogenic carbonate grains unconformably draped the ridges and rapidly consolidated into a distinct sandy calcarenite unit. Further east, sand sheets and low dunes partly pedogenized following their incursion, but did not cement. The water retention capacities of the sand sheets enabled the establishment of a sand-stabilizing vegetation cover that probably became an attractive environment for fuel and grazing. The growing Hellenistic-Roman-Byzantine ( 2.4-1.3 ka) populations probably led to increased consumption and massive destruction of sand stabilizing vegetation, enabling sand erodibility and mobilization during winter storms. The sand

  11. Identification and Quantification of Processes Affecting the Fate of Ethanol-Blended Fuel in the Subsurface

    Science.gov (United States)

    Devries, J. M.; Mayer, K. U.

    2015-12-01

    At present, the oil and gas industry distributes gasoline with an ethanol content of up to 10% (E10) to the consumer. However, ethanol advocates are promoting gasoline blends with higher ethanol content to be introduced into the market (e.g., E20, corresponding to an ethanol content of 20%). The likelihood of unintended fuel releases with elevated ethanol concentrations through surficial spills or from underground storage systems will therefore increase. A particular concern is the increased rate of CH4 and CO2 production as the spill biodegrades, which is believed to be associated with the increased ethanol content in the fuel. Consequently, high gas generation rates associated with ethanol-blended fuels may amplify the risk of vapor intrusion of CH4 and BTEX into basements or other subsurface structures that may be nearby. A comprehensive and comparative study on the fate of higher concentration ethanol-blended fuels in the subsurface has not been conducted to date. The present study focuses on determining the fate of ethanol blended fuels in the subsurface through a series of controlled and instrumented laboratory column experiments. The experiments compare the behavior of pure gasoline with that of ethanol-blended fuels for different soil types (sand and silt) in columns 2 meters tall and 30cm in diameter. The column experiments focus on the quantification of gas generation by volatilization and biodegradation and 1-D vertical fate and transport of CO2, CH4, benzene and toluene through the vadose zone. The fuel blends have been injected into the lower third of the columns and gas composition and fluxes within the column are being monitored over time. The goal of this study is to contribute to the scientific foundation that will allow gauging the level of risk and the need for remediation at fuel spill sites with higher ethanol blends.

  12. Vulnerability of shallow ground water and drinking-water wells to nitrate in the United States: Model of predicted nitrate concentration in U.S. ground water used for drinking (simulation depth 50 meters) -- Input data set for semiconsolidated sand aquifers (gwava-dw_semc)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the presence or absence of semiconsolidated sand aquifers in the conterminous United States. The data set was used as an input data layer...

  13. Sands at Gusev Crater, Mars

    Science.gov (United States)

    Cabrol, Nathalie A.; Herkenhoff, Kenneth E.; Knoll, Andrew H.; Farmer, Jack D.; Arvidson, Raymond E.; Grin, E.A.; Li, Ron; Fenton, Lori; Cohen, B.; Bell, J.F.; Yingst, R. Aileen

    2014-01-01

    Processes, environments, and the energy associated with the transport and deposition of sand at Gusev Crater are characterized at the microscopic scale through the comparison of statistical moments for particle size and shape distributions. Bivariate and factor analyses define distinct textural groups at 51 sites along the traverse completed by the Spirit rover as it crossed the plains and went into the Columbia Hills. Fine-to-medium sand is ubiquitous in ripples and wind drifts. Most distributions show excess fine material, consistent with a predominance of wind erosion over the last 3.8 billion years. Negative skewness at West Valley is explained by the removal of fine sand during active erosion, or alternatively, by excess accumulation of coarse sand from a local source. The coarse to very coarse sand particles of ripple armors in the basaltic plains have a unique combination of size and shape. Their distribution display significant changes in their statistical moments within the ~400 m that separate the Columbia Memorial Station from Bonneville Crater. Results are consistent with aeolian and/or impact deposition, while the elongated and rounded shape of the grains forming the ripples, as well as their direction of origin, could point to Ma'adim Vallis as a possible source. For smaller particles on the traverse, our findings confirm that aeolian processes have dominated over impact and other processes to produce sands with the observed size and shape patterns across a spectrum of geologic (e.g., ripples and plains soils) and aerographic settings (e.g., wind shadows).

  14. Mechanical and Hydraulic Properties of Wax-coated Sands for Sport Surfaces

    Science.gov (United States)

    Bardet, J. P.; Benazza, C.; Bruchon, J. F.; Mishra, M.

    2009-06-01

    Natural soils such as sandy loams are being replaced by synthetic soils for various types of sport and recreational surfaces, including horseracing tracks. These synthetic soils are made of a mixture of sand, microcrystalline wax, synthetic fibers and rubber chips which optimize the mechanical and hydraulic properties of natural soils so that they drain faster after rainstorms and decrease risks of sport injuries while retaining appropriate sport performances. Silica sand, which makes up the largest fraction of synthetic soils, is hydrophyllic by nature, i.e., tends to retain water on sand grain surfaces. After rainstorms, hydrophilic surfaces retain a large amount of water, are difficult to compact, and yield uncontrollable mechanical and hydraulic properties when too moist. The addition of wax contributes to improving both mechanical and hydraulic properties of sands. Wax coats the sand grains with a thin layer, and enhances adherence between sand particles. It repels water from sand grains and influences both compaction and hydraulic properties. This study reports experimental results that help to understand the properties of wax-coated sands used in synthetic surfaces, especially the degradation of synthetic surfaces that have insufficient wax-coatings.

  15. An Investigation into the Use of Manufactured Sand as a 100% Replacement for Fine Aggregate in Concrete

    Directory of Open Access Journals (Sweden)

    Martins Pilegis

    2016-06-01

    Full Text Available Manufactured sand differs from natural sea and river dredged sand in its physical and mineralogical properties. These can be both beneficial and detrimental to the fresh and hardened properties of concrete. This paper presents the results of a laboratory study in which manufactured sand produced in an industry sized crushing plant was characterised with respect to its physical and mineralogical properties. The influence of these characteristics on concrete workability and strength, when manufactured sand completely replaced natural sand in concrete, was investigated and modelled using artificial neural networks (ANN. The results show that the manufactured sand concrete made in this study generally requires a higher water/cement (w/c ratio for workability equal to that of natural sand concrete due to the higher angularity of the manufactured sand particles. Water reducing admixtures can be used to compensate for this if the manufactured sand does not contain clay particles. At the same w/c ratio, the compressive and flexural strength of manufactured sand concrete exceeds that of natural sand concrete. ANN proved a valuable and reliable method of predicting concrete strength and workability based on the properties of the fine aggregate (FA and the concrete mix composition.

  16. Laboratory investigations of effective flow behavior in unsaturated heterogeneous sands

    DEFF Research Database (Denmark)

    Wildenschild, Dorthe; Høgh Jensen, Karsten

    1999-01-01

    such that on the average a uniform pressure profile was established and gravity flow applied. Solute breakthrough curves measured at discrete points in the tank using time domain reflectometry, as well as dye tracer paths, showed that flow and transport took place in a very tortuous pattern where several grid cells were...... controlled method. The heterogeneous sand systems were established in a laboratory tank for three realizations of random distributions of the homogeneous sands comprising a system of 207 grid cells. The water flux was controlled at the upper boundary, while a suction was applied at the lower boundary...

  17. Effects of water stress on seedling biomass of several sand-fixing shrubs%水分胁迫对几种固沙灌木幼苗生物量的影响

    Institute of Scientific and Technical Information of China (English)

    王青宁; 衣学慧; 王晗生; 韩刚; 赵忠

    2014-01-01

    The seedlings of six sand-fixing shrubs were grown in the pots whose soil moisture contents were controlled by weighing to simulate suitable water condition,moderate drought,and severe drought for a long time,and the suitable water condition was taken as the control to determine biomass changes under water stress and analyze their drought adaptability as well.The results showed that as the soil moisture content reduced,total biomass and its components of every shrub were declined without exception.But in response to the soil moisture,the aboveground biomass proportion in total biomass decreased while the root biomass proportion in total biomass and root-shoot ratio all increased.The aboveground part biomass was affected by the soil drought greatly,and the underground part biomass was not affected much by water stress.All the six shrubs showed definite drought resistance,and could accommodate moderate drought. Moreover,Caragana korshinskii,Atraphaxis bracteata,and Atriplex canescens showed good adaptation to severe drought.Among six shrubs,the strongest in drought resistance was Atraphaxis bracteata,followed by Caraganakorshinskii and Atriplexcanescens.Hedysarummongolicum and Hedysarumscoparium were in the third place.Buddlejaalternifolia was comparatively weak in drought resistance.In their roots there were the common characteristics for adapting to the soil drought,but their aboveground parts differed from each other in stem and leaf chages.%采用模拟长时间干旱的控水盆栽方法处理6种固沙灌木的幼苗,以适宜水分条件为对照,测定水分胁迫下的生物量变化并分析其抗旱适应性.结果表明:随着土壤含水量的减少,6个树种的总生物量及其组分(根、茎、叶)生物量均下降;地上部分生物量比例均减小,而根生物量比例及根冠比都增大.地上部分生物量受干旱影响较大,其次为植物株整体,地下部分所受影响较小.6种灌木均具有一定的抗旱性,都能

  18. Stabilization of sand dunes with oil residue:Application to civil engineering construction and environmental implications

    Institute of Scientific and Technical Information of China (English)

    Esmail Aflaki; Alborz Hajiannia

    2015-01-01

    The present work ascertains the feasibility of oil residue treatment for stabilizing wind-blown sand dunes. Various combinations of natural collapsible saline from the Jandaq desert of Iran and oil residue from distillation towers of Iranian refineries were tested in laboratory experiments. Stabilized sands were evaluated in terms of geotechnical properties, permeability, and oil retention characteristics (i.e. bonding mechanisms, leaching and migrating behaviour of oil residue from the stabilized sands). Since the presence of oil residue in soils can pose an environmental threat, the optimum retention capacity of the stabilized sands is of critical concern. Relative to sand that was not augmented with oil residue, specimens made of 7% oil residues had the highest compressive strength, significantly higher cohesion and load bearing capacity, and considerably lower permeability. The effect of distilled water, saline water and municipal sewage on prepared specimens were also evaluated.

  19. A model for evaluating effects of climate, water availability, and water management on wetland impoundments--a case study on Bowdoin, Long Lake, and Sand Lake National Wildlife Refuges

    Science.gov (United States)

    Tangen, Brian A.; Gleason, Robert A.; Stamm, John F.

    2013-01-01

    Many wetland impoundments managed by the U.S. Fish and Wildlife Service (USFWS) National Wildlife Refuge System throughout the northern Great Plains rely on rivers as a primary water source. A large number of these impoundments currently are being stressed from changes in water supplies and quality, and these problems are forecast to worsen because of projected changes to climate and land use. For example, many managed wetlands in arid regions have become degraded owing to the long-term accumulation of salts and increased salinity associated with evapotranspiration. A primary goal of the USFWS is to provide aquatic habitats for a diversity of waterbirds; thus, wetland managers would benefit from a tool that facilitates evaluation of wetland habitat quality in response to current and anticipated impacts of altered hydrology and salt balances caused by factors such as climate change, water availability, and management actions. A spreadsheet model that simulates the overall water and salinity balance (WSB model) of managed wetland impoundments is presented. The WSB model depicts various habitat metrics, such as water depth, salinity, and surface areas (inundated, dry), which can be used to evaluate alternative management actions under various water-availability and climate scenarios. The WSB model uses widely available spreadsheet software, is relatively simple to use, relies on widely available inputs, and is readily adaptable to specific locations. The WSB model was validated using data from three National Wildlife Refuges with direct and indirect connections to water resources associated with rivers, and common data limitations are highlighted. The WSB model also was used to conduct simulations based on hypothetical climate and management scenarios to demonstrate the utility of the model for evaluating alternative management strategies and climate futures. The WSB model worked well across a range of National Wildlife Refuges and could be a valuable tool for USFWS

  20. DPTM simulation of aeolian sand ripple

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Aeolian sand ripple and its time evolution are simulated by the discrete particle tracing method (DPTM) presented in this paper. The difference between this method and the current methods is that the former can consider the three main factors relevant to the formation of natural aeolian sand ripples,which are the wind-blown sand flux above the sand bed formed by lots of sand particles with different di-ameters,the particle-bed collision and after it the rebound and ejection of sand particles in the sand bed,the saltation of high-speed sand particles and the creep of low-speed sand particles,respectively. The simulated aeolian sand ripple is close to the natural sand ripple not only in basic shape and characteristic,particle size segregation and stratigraphy,but also in formation stages. In addition,three important speeds can be obtained by this method,which are the propagation speed of the saturated aeolian sand ripple and the critical frictional wind speeds of emergence and disappearance of sand ripple.

  1. DPTM simulation of aeolian sand ripple

    Institute of Scientific and Technical Information of China (English)

    ZHENG XiaoJing; BO TianLi; XIE Li

    2008-01-01

    Aeolian sand ripple and its time evolution are simulated by the discrete particle tracing method (DPTM) presented in this paper.The difference between this method and the current methods is that the former can consider the three main factors relevant to the formation of natural aeolian sand ripples, which are the wind-blown sand flux above the sand bed formed by lots of sand particles with different di-ameters, the particle-bed collision and after it the rebound and ejection of sand particles in the sand bed, the saltation of high-speed sand particles and the creep of low-speed sand particles, respectively.The simulated aeolian sand ripple is close to the natural sand ripple not only in basic shape and characteristic, particle size segregation and stratigraphy, but also in formation stages.In addition, three important speeds can be obtained by this method, which are the propagation speed of the saturated aeolian sand ripple and the critical frictional wind speeds of emergence and disappearance of sand ripple.

  2. Dry reusing and wet reclaiming of used sodium silicate sand

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Based on the characteristics of used sodium silicate sand and the different use requirements for recycled sand