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Sample records for ashing wet

  1. Transformations in oil shale ash at wet deposition

    International Nuclear Information System (INIS)

    Estonian oil shale ash contains chemically active compounds which would undergo different spontaneous transformations in the atmosphere of air. For explaining these processes the system ash-water-air was studied storing moisture samples of ash in laboratory in open-air as well as hermetic conditions. The samples of dry ash formed at pulverized combustion of oil shale at the Baltic Power Plant, and samples obtained from ash storing plateau from different depth of different boreholes were under investigation. Storing conditions as well as the properties of initial samples have a great influence upon the processes taking place at storing of ashes. The results obtained could be used to explain and control the processes taking place at storing of ashes under atmospheric (wet) conditions

  2. Wet physical separation of MSWI bottom ash

    NARCIS (Netherlands)

    Muchova, L.

    2010-01-01

    Bottom ash (BA) from municipal solid waste incineration (MSWI) has high potential for the recovery of valuable secondary materials. For example, the MSWI bottom ash produced by the incinerator at Amsterdam contains materials such as non-ferrous metals (2.3%), ferrous metals (8-13%), gold (0.4 ppm),

  3. Geological behavior of wet outflow deposition fly ash

    Institute of Scientific and Technical Information of China (English)

    周德泉; 赵明华; 刘宏利; 周毅; 严聪

    2008-01-01

    The geological behaviors of wet outflow deposition fly ash were investigated, including the feature of in-situ single and even bridge cone penetration test (CPT) curves, the change of the penetration parameters and vane strength with the increase of depth and the difference of the penetration resistance on and down the water level. Drilling, CPT and vane shear test were carried out in silty clay, fine sand, and fly ash of the ash-dam. The CPT curves of the fly ash do not show a critical depth. The cone resistance (qc) of the fly ash is smaller than that of silty clay or sand; the friction resistance is smaller than that of filling silty clay, similar to that of deposition silty clay or more than that of fine sand; the friction ratio is smaller than that of filling silty clay, or more than that of deposition silty clay or much more than that of fine sand. The specific penetration resistance (ps) is similar to that of filling silty clay, or more than that of deposition silty clay. There is a clear interface effect between the deposition fly ash and the clay. Interface effect of ps-h curve at the groundwater table is clear, and ps of the fly ash reduces significantly under the table. The vane strength of the fly ash increases as the depth increases. The deposition fly ash with wet outflow is similar to silt in the geological behavior.

  4. Wet physical separation of MSWI bottom ash

    OpenAIRE

    Muchova, L.

    2010-01-01

    Bottom ash (BA) from municipal solid waste incineration (MSWI) has high potential for the recovery of valuable secondary materials. For example, the MSWI bottom ash produced by the incinerator at Amsterdam contains materials such as non-ferrous metals (2.3%), ferrous metals (8-13%), gold (0.4 ppm), silver (10 ppm), stainless steel (0.1%) and minerals that can be converted into building products such as aggregates utilized for concrete, asphalt, etc. Since the composition of BA varies from cou...

  5. Effects of pulverized coal fly-ash addition as a wet-end filler in papermaking

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, A.S.K. [SLIET, Longowal (India). Dept. of Chemical Technology

    2008-09-15

    This experimental study is based on the innovative idea of using pulverized coal fly ash as a wet-end filler in papermaking. This is the first evaluation of the possible use of fly ash in the paper industry. Coal-based thermal power plants throughout the world are generating fly ash as a solid waste product. The constituents of fly ash can be used effectively in papermaking. Fly ash has a wide variation in particle size, which ranges from a few micrometers to one hundred micrometers. Fly ash acts as an inert material in acidic, neutral, and alkaline papermaking processes. Its physical properties such as bulk density (800-980 kg/m{sup 3}), porosity (45%-57%), and surface area (0.138-2.3076 m{sup 2}/g) make it suitable for use as a paper filler. Fly ash obtained from thermal power plants using pulverized coal was fractionated by a vibratory-sieve stack. The fine fraction with a particle size below 38 micrometers was used to study its effect on the important mechanical-strength and optical properties of paper. The effects of fly-ash addition on these properties were compared with those of kaolin clay. Paper opacity was found to be much higher with fly ash as a filler, whereas brightness decreased as the filler percentage increased Mechanical strength properties of the paper samples with fly ash as filler were superior to those with kaolin clay.

  6. Wet treatment of ashes, a survey of methods; Vaat rening av askor, metodoeversikt

    Energy Technology Data Exchange (ETDEWEB)

    Bjurstroem, Henrik [AaF-Energi och Miljoe AB, Stockhom (Sweden); Steenari, Britt-Marie [Chalmers Univ. of Technology, Goeteborg (Sweden)

    2003-10-01

    Ash contains elements and compounds that are questionable from an environmental point of view, such as very soluble salts, alkali yielding a high pH-value, metals, heavy metals and organic compounds. When ash is to be used, one requires that it is stable, i. e. that it does not influence the immediate surroundings and the environment in a negative way. Stability means that water that comes into contact with ash shall not pick up environmentally disruptive compounds to any significant extent. The presence of heavy metals in the ash does not always lead to their being leached to the surroundings, but it does always imply an uncertainty. It is probable that fly ash from incineration of municipal solid waste has to be treated in some way before it is landfilled. Washing the ash or dissolving it partially with a solvent such as water or an acid is a relatively simple method to reduce the risk for contamination of the environment by removing soluble compounds from the ash. Such methods consist of techniques that in other applications are proven and robust, and that may be adapted to the present conditions: the composition and the properties of the ash. In this report, a survey of methods is presented. Wet treatments may be apprehended as a combined separation and concentration process: on the one hand environmentally disruptive compounds are removed from ash, on the other hand these are concentrated in a remainder survival remission rate. These methods are a perfect pretreatment for various stabilization methods, a. o. thermal treatments such as vitrifying or sintering, or for utilization of the ashes e. g. in public works as they remove the obstacles to a good performance, namely the soluble salts. In this report are presented a systematic description of wet treatments aiming at purification and a survey of methods of industrial interest. A certain number of wet treatment methods are in operation outside Sweden, principally for fly ash from municipal solid waste

  7. Rainfall and wet and dry cycle's impact on ash thickness. A laboratory experiment

    Science.gov (United States)

    Pereira, Paulo; Keestra, Saskia; Peters, Piet; Cerdà, Artemi

    2016-04-01

    Ash is the most important and effective soil protection in the immediate period after the fire (Cerda and Doerr, 2008; Pereira et al., 2015a). This protection can last for days or weeks depending on the fire severity, topography of the burned area and post-fire meteorological conditions. In the initial period after the fire, ash is easily transported by wind. However after the first rainfalls, ash is eroded, or bind in soil surface (Pereira et al., 2013, 2015a). Ash thickness has implications on soil protection. The soil protection against the erosion and the ash capacity to retain water increases with the ash thickness (Bodi et al., 2014). Ash cover is very important after fire because store water and releases into soil a large amount of nutrients, fundamental to vegetation recuperation (Pereira et al., 2014). Despite the importance of ash thickness in post fire environments, little information is available about the effects of rainfall and wet and dry cycle's effects on ash thickness. This work aims to fill this gap. The objective of this study is to investigate the impacts of rainfall and wet and dry cycles in the ash thickness of two different under laboratory conditions. Litter from Oak (Quercus robur) and Spruce (Picea abis) were collected to and exposed during 2 hours to produce ash at 200 and 400 C. Subsequently a layer of 15 mm ash was spread on soil surface in small boxes (24x32 cm) and then subjected to rainfall simulation. Boxes were placed at a 17% of inclination and a rainfall intensity of 55 mm/h during 40 minutes was applied. After the rainfall simulation the plots were stored in an Oven at the temperature of 25 C during four days, in order to identify the effects of wet and dry cycles (Bodi et al., 2013). Ash thickness was measured after the first rainfall (AFR), before the second rainfall (BSR) - after the dry period of 4 days - and after the second rainfall (ASR). In each box a grid with 57 points was designed in order to analyse ash thickness

  8. Wet-dry cycles effect on ash water repellency. A laboratory experiment.

    Science.gov (United States)

    Pereira, Paulo; Cerdà, Artemi; Oliva, Marc; Mataix, Jorge; Jordán, Antonio

    2014-05-01

    In the immediate period after the fire, the ash layer has a strong influence on soil hydrological processes, as runoff, infiltration and erosion. Ash is very dynamic in the space and time. Until the first rainfall periods, ash is (re)distributed by the wind. After it can cover the soil surface, infiltrate or transported to other areas by water transport (Pereira et al., 2013a, b). This will have strong implications on nutrient redistribution and vegetation recovery. Ash layer may affect soil water repellency in different ways, depending on fire severity, soil properties and vegetation. Ash produced at low temperatures after low-severity burning is usually hydrophobic (Bodi et al., 2011, 2012). Wet-dry cycles have implications on ash physical and chemical properties, changing their effects in space and time. The aim of this study is to analyse the effects of fire temperature and severity on ash water repellency. Pinus sylvestris needles were collected in a Lithuania forest in Dzukija National Park (53º 54' N and 24º 22' E), transported to laboratory and washed with deionized water to remove soil particles and other residues. Needle samples were dried during 24 hours and exposed to different temperatures: 200, 300, 400 and 500 ºC, during 2 hours. Ash colour was analysed according to the Munsell Soil Color charts. Ash was black (10 YR 2/1) at 200 ºC, very dark grey (10YR 3/1) at 300 ºC, gray (10YR 5/1) at 400 ºC and light gray (10YR 7/1) at 500 ºC. Ten samples of ash released after each treatment were placed in plastic dishes (50 mm in diameter) in an amount enough to form a 5 mm thick layer, and ash water repellency was measured according to the Water Drop Penetration Test. Later, ash was carefully wetted with 15 ml of deionized water and placed in an oven during 4 days (96 hours), as in Bodí et al. (2012). This procedure was repeated 5 times in order to observe the effects of wet-dry cycles in ash water repellency. The results showed significant differences

  9. Wet-dry cycles effect on ash water repellency. A laboratory experiment.

    Science.gov (United States)

    Pereira, Paulo; Cerdà, Artemi; Oliva, Marc; Mataix, Jorge; Jordán, Antonio

    2014-05-01

    In the immediate period after the fire, the ash layer has a strong influence on soil hydrological processes, as runoff, infiltration and erosion. Ash is very dynamic in the space and time. Until the first rainfall periods, ash is (re)distributed by the wind. After it can cover the soil surface, infiltrate or transported to other areas by water transport (Pereira et al., 2013a, b). This will have strong implications on nutrient redistribution and vegetation recovery. Ash layer may affect soil water repellency in different ways, depending on fire severity, soil properties and vegetation. Ash produced at low temperatures after low-severity burning is usually hydrophobic (Bodi et al., 2011, 2012). Wet-dry cycles have implications on ash physical and chemical properties, changing their effects in space and time. The aim of this study is to analyse the effects of fire temperature and severity on ash water repellency. Pinus sylvestris needles were collected in a Lithuania forest in Dzukija National Park (53º 54' N and 24º 22' E), transported to laboratory and washed with deionized water to remove soil particles and other residues. Needle samples were dried during 24 hours and exposed to different temperatures: 200, 300, 400 and 500 ºC, during 2 hours. Ash colour was analysed according to the Munsell Soil Color charts. Ash was black (10 YR 2/1) at 200 ºC, very dark grey (10YR 3/1) at 300 ºC, gray (10YR 5/1) at 400 ºC and light gray (10YR 7/1) at 500 ºC. Ten samples of ash released after each treatment were placed in plastic dishes (50 mm in diameter) in an amount enough to form a 5 mm thick layer, and ash water repellency was measured according to the Water Drop Penetration Test. Later, ash was carefully wetted with 15 ml of deionized water and placed in an oven during 4 days (96 hours), as in Bodí et al. (2012). This procedure was repeated 5 times in order to observe the effects of wet-dry cycles in ash water repellency. The results showed significant differences

  10. Properties of fly ashes in wet environment; Flygaskors egenskaper i vaat miljoe

    Energy Technology Data Exchange (ETDEWEB)

    Broemssen, M. von; Lindstroem, N.; Hedman, K.; Svensson, M.

    2009-03-15

    This report describes how inorganic elements are mobilised from fly ashes that are placed under water, i.e. what are the properties and processes that governs the mobilisation. This knowledge may serve as basic data for decision making when fly ashes from e.g. bio-, industrial- and municipal solid wastes are to be used in civil engineering applications in wet environments. The composition of ashes varies in a vide range of concentrations and depends on the fuel and the type of incinerator. The main contents of fly ashes are calcium oxide, silicic acid and aluminium compounds. Several environmental hazardous elements are also present in varying concentrations. The pH of fishily is often very high. A number of chemical processes occur when flyashes is mixed with water. When the pH-value increases, mainly due to hydratisation of calcium oxide (CaO), many metals will precipitate as metal hydroxides. The objective of this study was to, within a rather short time period (8 month), describe the processes governing mobilisation of different elements from fly ashes placed under water. The work included chemical equilibrium modelling with PHREEQC, the model was used to determine what minerals may control solubility of different elements. Three fly ashes were used for the study, one flyash from industrial- and municipal waste with no CaO or ammonia added, one flyash from municipal waste with CaO and ammonia added and one fly ash from solid biofuels with chalk added. The fly ashes, ca 300 kg, was mixed with water in 1000 l plastic containers and filled with water. Two batches per flyash were used; i) in the first batch surplus water were not replaced, ii) in the second batch the surplus water was replaced with fresh water five times during the test. Measured pH-values in the batches with industrial and municipal waste were stabilised at a pH-value around 9.5 indicating carbonation is complete. The pH-values in the bio flyash were higher. Four categories of elements were

  11. Wet-Treated MSWI Fly Ash Used as Supplementary Cementitious Material

    Directory of Open Access Journals (Sweden)

    Martin Keppert

    2015-01-01

    Full Text Available Municipal solid waste incineration (MSWI is a common technique in treatment of domestic waste. This technique annually produces approximately 25 Mt solid residues (i.e., bottom and fly ash worldwide which is also a major issue in current research. In this research we are concerned with reusing the fly ash (FA as supplementary cementitious material (SCM in concrete. Such application solves the problem with heavy metal immobilization as well. To remove the high content of undesired soluble salts, number of washing treatments has been applied. Chemical composition of FA has been examined before and after treatments. The impact of cement substitution by FA in concrete was evaluated by measurement of its compressive strength and durability.

  12. Characteristic of wet method of phosphorus recovery from polish sewage sludge ash with nitric acid

    Directory of Open Access Journals (Sweden)

    Gorazda Katarzyna

    2016-12-01

    Full Text Available Sewage Sludge Ash (SSA is a concentrated source of phosphorus and can be successfully recycled via a number of different routes. This paper presents research results on phosphorus recovery from differently combusted sewage sludge with the use of nitric acid extraction. Different SSA forms from Polish thermal utilization stations were compared. It was revealed that sewage treatment technology as well as combustion technology influence many physical and chemical parameters of ashes that are crucial for further phosphorus recovery from such waste according to the proposed method. Presented research defines extraction efficiency, characterized extracts composition and verifies the possibility of using SSA as cheaper and alternative sources of phosphorus compounds. Gdynia, Kielce and Kraków SSA have the best properties for the proposed technology of phosphorus recovery with high extraction efficiency greater than 86%. Unsuitable results were obtained for Bydgoszcz, Szczecin Slag and Warszawa SSA. Extraction process for Łódź and Szczecin Dust SSA need to be improved for a higher phosphorus extraction efficiency greater than 80%.

  13. Reclamation of acid, toxic coal spoils using wet flue gas desulfurization by-product, fly ash and sewage sludge. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kost, D.A.; Vimmerstedt, J.P.; Stehouwer, R.C.

    1997-03-01

    Establishment of vegetation on acid abandoned minelands requires modification of soil physical and chemical conditions. Covering the acid minesoil with topsoil or borrow soil is a common practice but this method may be restricted by availability of borrow soil and cause damage to the borrow site. An alternative approach is to use waste materials as soil amendments. There is a long history of using sewage sludge and fly ash as amendments for acid minesoils. Flue gas desulfurization (FGD) by-products are newer materials that are also promising amendments. Most flue gas sludges are mixtures of Calcium sulfate (CaSO{sub 4}), calcium sulfite (CaSO{sub 3}), calcium carbonate (CaCO{sub 3}), calcium hydroxide [Ca(OH){sub 2}], and fly ash. Some scrubbing processes produce almost pure gypsum (CaSO{sub 4}2H{sub 2}O). The primary purpose of the project is to evaluate two wet FGD by-products for effects on vegetation establishment and surface and ground water quality on an acid minesoil. One by-product from the Conesville, OH power plant (American Electric Power Service Corporation) contains primarily calcium sulfite and fly ash. The other by-product (Mg-gypsum FGD) from an experimental scrubber at the Zimmer power plant (Cincinnati Gas and Electric Company) is primarily gypsum with 4% magnesium hydroxide. These materials were compared with borrow soil and sewage sludge as minesoil amendments. Combinations of each FGD sludge with sewage sludge were also tested. This report summarizes two years of measurements of chemical composition of runoff water, ground water at two depths in the subsoil, soil chemical properties, elemental composition and yield of herbaceous ground cover, and elemental composition, survival and height of trees planted on plots treated with the various amendments. The borrow soil is the control for comparison with the other treatments.

  14. Reclamation of acid, toxic coal spoils using wet flue gas desulfurization by-product, fly ash and sewage sludge. Final report

    International Nuclear Information System (INIS)

    Establishment of vegetation on acid abandoned minelands requires modification of soil physical and chemical conditions. Covering the acid minesoil with topsoil or borrow soil is a common practice but this method may be restricted by availability of borrow soil and cause damage to the borrow site. An alternative approach is to use waste materials as soil amendments. There is a long history of using sewage sludge and fly ash as amendments for acid minesoils. Flue gas desulfurization (FGD) by-products are newer materials that are also promising amendments. Most flue gas sludges are mixtures of Calcium sulfate (CaSO4), calcium sulfite (CaSO3), calcium carbonate (CaCO3), calcium hydroxide [Ca(OH)2], and fly ash. Some scrubbing processes produce almost pure gypsum (CaSO42H2O). The primary purpose of the project is to evaluate two wet FGD by-products for effects on vegetation establishment and surface and ground water quality on an acid minesoil. One by-product from the Conesville, OH power plant (American Electric Power Service Corporation) contains primarily calcium sulfite and fly ash. The other by-product (Mg-gypsum FGD) from an experimental scrubber at the Zimmer power plant (Cincinnati Gas and Electric Company) is primarily gypsum with 4% magnesium hydroxide. These materials were compared with borrow soil and sewage sludge as minesoil amendments. Combinations of each FGD sludge with sewage sludge were also tested. This report summarizes two years of measurements of chemical composition of runoff water, ground water at two depths in the subsoil, soil chemical properties, elemental composition and yield of herbaceous ground cover, and elemental composition, survival and height of trees planted on plots treated with the various amendments. The borrow soil is the control for comparison with the other treatments

  15. Sustainable High Quality Recycling of Aggregates from Waste-to-Energy, Treated in a Wet Bottom Ash Processing Installation, for Use in Concrete Products

    Directory of Open Access Journals (Sweden)

    Philip Van den Heede

    2015-12-01

    Full Text Available Nowadays, more efforts towards sustainability are required from the concrete industry. Replacing traditional aggregates by recycled bottom ash (BA from municipal solid waste incineration can contribute to this goal. Until now, only partial replacement has been considered to keep the concrete workability, strength and durability under control. In this research, the feasibility of a full aggregate replacement was investigated for producing prefabricated Lego bricks. It was found that the required compressive strength class for this purpose (C20/25 could be achieved. Nevertheless, a thorough understanding of the BA properties is needed to overcome other issues. As BA is highly absorptive, the concrete’s water demand is high. This workability issue can be dealt with by subjecting the fine BA fraction to a crushing operation to eliminate the porous elements and by pre-wetting the fine and coarse BA fractions in a controlled manner. In addition, a reactive NaOH washing is needed to avoid formation of longitudinal voids and the resulting expansion due to the metallic aluminum present in the BA. Regarding the long-term behavior, heavy metal leaching and freeze-thaw exposure are not problematic, though there is susceptibility to acetic and lactic acid attack and maybe increased sensitivity to alkali-silica reaction.

  16. Long term effects on wet stored calcium rich fly ash with bearing on ground improvement work; Laangtidspaaverkan av kalkrika flygaskor vid vaatlagring foer anvaendning inom markstabilisering

    Energy Technology Data Exchange (ETDEWEB)

    Lagerlund, Johan; Jansing, Christiane

    2012-02-15

    Generation of electricity and heat by means of thermal power demands a product that can be ignited. This combustible material is usually coal, oil, gas, biomass and waste. If using solid fuels as coal, biomass and waste a by product known as ash is formed in the process; FA, (FA) and bottom ash. Roughly 600 Mt ashes are annually produced throughout the world and 70 weight % of these ashes are FA, 25 weight % bottom ashes and 5 weight % slag. 41 weight % of all ashes are annually reused in some form. Given the environmental impact of combustion i.e. CO{sub 2} emissions, a widened use of biomass fuels and co-combustion is expected in the near future. This will however create new problems when reusing ashes and FA in particular. The reuse of FA within the concrete industry stand for a total of about 25 % but the reuse of non-coal derived FA in the concrete industry is prohibited. Non-coal derived FA usually has higher amounts of calcium oxide, which acts expansively in concrete. Less than 20 % of biomass or co-combustion FA are reused today in Europe. A new standard, the EN 450, is however under construction. This standard will deal with the reuse of noncoal derived FA within the cement and concrete industry. In Sweden, coal is very seldom used as a fuel. More common is the use of biomass, peat and waste. It means that the FA are all non-coal derived and thus derived from reuse within the cement and concrete industry. Beside their non-coal origin, the main part of the FA is produced during November- March. This means that it might be hard to find available FA all year around, making the reuse of FA less attractive. Hence, FA must be stored prior to use. Little research have been made on the storage of calcium rich FA from biomass and co-combustion. Storing FA in a cheap way requires an addition of water to prevent from dusting when stockpiled outdoors. Addition of water in calcium rich FA will however cause an hardening of the material, thus causing detrimental

  17. Total arsenic in foods after sequential wet digestion, dry ashing, coprecipitation with ammonium pyrrolidine dithiocarbamate, and graphite-furnace atomic absorption spectrometry

    International Nuclear Information System (INIS)

    A graphite-furnace atomic absorption (GFAAS) method is described for determining total arsenic (organic and inorganic compounds) in foods. Samples ranging from 1 to 40 g (depending on moisture content) were digested with HNO3 and dry-ashed at 500 degree C overnight after addition of MgO. After dissolution in HCl, the arsenic was reduced with iodide and ascorbic acid and precipitated with ammonium pyrrolidine dithiocarbamate (APDC) in the presence of nickel carrier. Precipitates were collected on 0.3μm cellulose acetate filters and dissolved in 10% HNO3 containing modifier. Ba(NO3)2 was added to remove a sulfate interference resulting from decomposition of APDC. Arsenic was determined using GFAAS. Accuracy of the method was good for 7 US National Bureau of Standards (NBS) Standard Reference Materials and 3 National Research Council of Canada (NRCC) round-robin samples. Recovery of arsenic(V) from foods averaged 99.2% for peak heights and 97.1% for peak areas, with relative standard deviations (RSD) of 2.2% for peak heights and 3.3% for peak areas for all NBS and NRCC materials. Detection limit of the method was ca 10 ng arsenic

  18. Ash in the Soil System

    Science.gov (United States)

    Pereira, P.

    2012-04-01

    , climate/meteorological conditions after the ash spread/fire and soil background characteristics. In addition, after the fire heating can change soil original properties increasing the complexity of the ash effects on soil properties. After fire, ash is highly dynamic and very easily transported by wind until the first rains. When wetted, ash compacts and binds onto soil surface, and wind has low capacity to transport it. The post-rain ash dynamic is influenced by water erosion (in slope areas), infiltration into soil profile and vegetation recuperation. This means that ash produced in one place will have implications in other areas, including not burned areas (e.g wind transport and water erosion). This is a clear indication that ash effects go much further than the fire affected area. Due the heterogeneity of soil and ash properties and their dynamic across the landscape, the impacts of ash on soil system can be diverse, producing a mosaic of different effects and responses after ash treatment and/ or fire. In this communication it will be presented and discussed the advances and scientific development of ash effects and dynamic in soil system.

  19. Removal of fly-ash and dust particulate matters from syngas produced by gasification of coal by using a multi-stage dual-flow sieve plate wet scrubber.

    Science.gov (United States)

    Kurella, Swamy; Meikap, Bhim Charan

    2016-08-23

    In this work, fly-ash water scrubbing experiments were conducted in a three-stage lab-scale dual-flow sieve plate scrubber to observe the performance of scrubber in fly-ash removal at different operating conditions by varying the liquid rate, gas rate and inlet fly-ash loading. The percentage of fly-ash removal efficiency increases with increase in inlet fly-ash loading, gas flow rate and liquid flow rate, and height of the scrubber; 98.55% maximum percentage of fly-ash removal efficiency (ηFA) is achieved at 19.36 × 10(-4) Nm(3)/s gas flow rate (QG) and 48.183 × 10(-6) m(3)/s liquid flow rate (QL) at 25 × 10(-3) kg/Nm(3) inlet fly-ash loading (CFA,i). A model has also been developed for the prediction of fly-ash removal efficiency of the column using the experimental results. The predicted values calculated using the correlation matched well with the experimental results. Deviations observed between the experimental and the predicted values were less than 20%. PMID:27230635

  20. Zipping Wetting

    CERN Document Server

    Sbragaglia, Mauro; Pirat, Christophe; Borkent, Bram M; Lammertink, Rob G H; Wessling, Matthias; Lohse, Detlef

    2007-01-01

    Water droplets can completely wet micro-structured superhydrophobic surfaces. The {\\it dynamics} of this rapid process is analyzed by ultra-high-speed imaging. Depending on the scales of the micro-structure, the wetting fronts propagate smoothly and circularly or -- more interestingly -- in a {\\it stepwise} manner, leading to a growing {\\it square-shaped} wetted area: entering a new row perpendicular to the direction of front propagation takes milliseconds, whereas once this has happened, the row itself fills in microseconds ({\\it ``zipping''}). Numerical simulations confirm this view and are in quantitative agreement with the experiments.

  1. Wetting transitions

    International Nuclear Information System (INIS)

    When a liquid droplet is put onto a surface, two situations distinguishable by the contact angle may result. If the contact angle is zero, the droplet spreads across the surface, a situation referred to as complete wetting. On the other hand, if the contact angle is between 0 deg. and 180 deg., the droplet does not spread, a situation called partial wetting. A wetting transition is a surface phase transition from partial wetting to complete wetting. We review the key experimental findings on this transition, together with simple theoretical models that account for the experiments. The wetting transition is generally first order (discontinuous), implying a discontinuity in the first derivative of the surface free energy. In this case, if one measures the thickness of the adsorbed film beside the droplet, at the wetting transition a discontinuous jump in film thickness occurs from a microscopically thin to a thick film. We show that this can lead to the observation of metastable surface states and an accompanying hysteresis. The observed hysteresis poses, in turn, a number of questions concerning the nucleation of wetting films that we also consider here. In addition, we consider the equilibrium wetting film thickness that results from a competition between the long-range van der Waals forces and gravity. Finally, the first-order character of the wetting transition can lead to a similar transition even when the phase that does the wetting is not (yet) stable in the bulk. For such prewetting transitions, a discontinuous thin-to-thick film transition occurs off bulk coexistence. We show that, for the large variety of systems for which prewetting transitions have been observed, the behaviour is surprisingly uniform, and can be mapped onto a simple generic phase diagram. The second part of the review deals with the exceptions to the first-order nature of the wetting transition. Two different types of continuous or critical wetting transition have been reported, for which

  2. Wetting and reaction characteristics of crystalline and amorphous SiO2 derived rice-husk ash and SiO2/SiC substrates with Al-Si-Mg alloys

    Science.gov (United States)

    Bahrami, A.; Pech-Canul, M. I.; Gutiérrez, C. A.; Soltani, N.

    2015-12-01

    A study of the wetting behavior of three substrate types (SiC, SiO2-derived RHA and SiC/SiO2-derived RHA) by two Al-Si-Mg alloys using the sessile drop method has been conducted, using amorphous and crystalline SiO2 in the experiment. Mostly, there is a transition from non-wetting to wetting contact angles, being the lowest θ values achieved with the alloy of high Mg content in contact with amorphous SiO2. The observed wetting behavior is attributed to the deposited Mg on the substrates. A strong diffusion of Si from the SiC/Amorphous RHA substrate into the metal drop explains the free Si segregated at the drop/substrate interface and drop surface. Although incorporation of both SiO2-derived RHA structures into the SiC powder compact substrates increases the contact angles in comparison with the SiC substrate alone, the still observed acute contact angles in RHA/SiC substrates make them promising for fabrication of composites with high volume fraction of reinforcement by the pressureless infiltration technique. The observed wetting characteristics, with decrease in surface tension and contact angles is explained by surface related phenomena. Based on contact angle changes, drop dimensions and surface tension values, as well as on the interfacial elemental mapping, and XRD analysis of substrates, some wetting and reaction pathways are proposed and discussed.

  3. Volcanic ash impacts on critical infrastructure

    Science.gov (United States)

    Wilson, Thomas M.; Stewart, Carol; Sword-Daniels, Victoria; Leonard, Graham S.; Johnston, David M.; Cole, Jim W.; Wardman, Johnny; Wilson, Grant; Barnard, Scott T.

    2012-01-01

    Volcanic eruptions can produce a wide range of hazards. Although phenomena such as pyroclastic flows and surges, sector collapses, lahars and ballistic blocks are the most destructive and dangerous, volcanic ash is by far the most widely distributed eruption product. Although ash falls rarely endanger human life directly, threats to public health and disruption to critical infrastructure services, aviation and primary production can lead to significant societal impacts. Even relatively small eruptions can cause widespread disruption, damage and economic loss. Volcanic eruptions are, in general, infrequent and somewhat exotic occurrences, and consequently in many parts of the world, the management of critical infrastructure during volcanic crises can be improved with greater knowledge of the likely impacts. This article presents an overview of volcanic ash impacts on critical infrastructure, other than aviation and fuel supply, illustrated by findings from impact assessment reconnaissance trips carried out to a wide range of locations worldwide by our international research group and local collaborators. ‘Critical infrastructure’ includes those assets, frequently taken for granted, which are essential for the functioning of a society and economy. Electricity networks are very vulnerable to disruption from volcanic ash falls. This is particularly the case when fine ash is erupted because it has a greater tendency to adhere to line and substation insulators, where it can cause flashover (unintended electrical discharge) which can in turn cause widespread and disruptive outages. Weather conditions are a major determinant of flashover risk. Dry ash is not conductive, and heavy rain will wash ash from insulators, but light rain/mist will mobilise readily-soluble salts on the surface of the ash grains and lower the ash layer’s resistivity. Wet ash is also heavier than dry ash, increasing the risk of line breakage or tower/pole collapse. Particular issues for water

  4. Wetting Splashing

    CERN Document Server

    Tsai, Peichun; Dijkstra, Remko; Lohse, Detlef

    2010-01-01

    We present fluid dynamics videos illustrating wetting splashing-produced by water drop impact onto hydrophobic microstructures at high impact velocity ($\\sim 3$ ms$^{-1}$). The substrate consists of regular and transparent microtextures in square or hexagonal lattice, yielding a high contact angle of $\\sim 150 ^\\circ$. Our high speed top-or-bottom view recordings through the transparent surface shed light on the solid-liquid-air interfaces at impact. Despite the superhydrophobicity of the latticed micropillars (of a periodicity of $10 {\\mu}m), water droplet wets a certain central area and moreover entraps an air bubble beneath the droplet. Besides the central wet area, lamella surf on air splashing outward at high impinging velocity. The effects of micropatterns and air pressure on the impact outcome are also examined. We show that microscopic boundary condition, imposed by the solid texture, profoundly influences the macroscopic flow dynamics upon superhydrophobic surfaces at high impinging velocity. In addi...

  5. PILOT SCALE STUDIES OF CLOSED-LOOP ASH SLUICING

    Science.gov (United States)

    The paper discusses pilot scale studies of closed-loop fly ash sluicing. Chemicals leached from fly ash in wet sluicing systems can cause scaling of equipment if the sluice water is recycled. A 50 gpm (190,000 cu cm/min) pilot unit was tested at two power plants to evaluate close...

  6. EDU 626 ASH

    OpenAIRE

    NARESH 40 course tutorial/tutorialoutlet

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com     Product Description EDU 626 Week 1 Research Topic (Ash) EDU 626 Week 2 Annotated Bibliography (Ash) EDU 626 Week 2 Critical Thinking Questions (Ash) EDU 626 Week 3 Procedures or Methods (Ash) EDU 626 Week 4 Critical Thinking Questions (Ash) EDU 626 Week 5 Critical Thinking Questions (Ash) EDU 626 Week 6 Final Paper (Ash)  

  7. Processing and utilization of wet flue gas desulfurization material

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, A.; Hassett, D.J. [Cooperative Power Association, Eden Prairie, MN (United States)]|[North Dakota Univ., Grand Forks, ND (United States). Energy and Environmental Research Center

    1997-05-01

    Cooperative Power`s Coal Creek Station (CCS) became fully operational in 1981. The two 550-MW units at CCS burn North Dakota lignite. The resulting by-products are fly ash, bottom ash, and wet FGD material. Although disposal of the coal combustion by-products (CCBs) was included in the original site plant at CCS, even early on, consideration was given to utilization of the fly ash as a mineral admixture for concrete and as a partial sorbent replacement for the wet scrubbing system. CCS fly ash has been successfully marketed into North Dakota, Minnesota, and the surrounding region as a construction material that is environmentally benign, highly consistent, and an excellent performer in numerous construction applications. Attempts to use CCS fly ash as part of the scrubbing medium in the wet scrubbing system at the site were not as successful as first hoped, primarily due to the abrasive nature of the fly ash. Currently, CCS scrubbers use lime as the scrubbing medium for SO{sub 2} removal. CCS`s efforts to market its fly ash have been successful, so with increased awareness of the economic advantages of by-product utilization, the favorable US Environmental Protection Agency (EPA) regulatory determination that CCBs are not hazardous, and the improved understanding of potential local and regional markets, Cooperative Power has taken additional steps to investigate the processing and utilization of its wet FGD material. These steps are discussed.

  8. Embankment over fly ash pond at Portsmouth Power Station

    International Nuclear Information System (INIS)

    The fly ash and bottom ash sediments from the Portsmouth Power Station in Portsmouth, Virginia were being sluiced into a 39 acre diked ash pond near the plant. When the ash level within the pond was an average of 4 feet below the crest of the dike, it was decided to enlarge the capacity of the disposal area. The plant was about to convert to dry ash disposal, and thus, the plan was to construct a 30-foot high fly ash embarkment over the previously ponded ash. To meet regulatory guidelines, the conversion from wet to dry disposal of fly ash required that the existing ''wet'' pond area be ''closed'' with an impermeable cover and that the new ''dry'' area have an impervious liner (a cover-liner system). This posed potential drainage constraints necessitating an underdrain system below the cover-liner system. The design had to address the stability of the new 30-foot ash embankment constructed over confined, saturated ponded ash and not adversely affect the stability of the perimeter dike. The design also had to provide for interim storage of sluiced fly ash, which resulted in a new inner perimeter dike (inside the existing main dike) and for long term storage for sluiced bottom ash. The sluiced bottom ash would be collected in a small segmented diked pond within the existing main dike. This paper describes the subsurface exploration, stability evaluation, underdrains, design, instrumentation results, and problems encountered during construction of this converted disposal area which extended the life of the facility a minimum of five years

  9. Solubility and transport of arsenic coal ash

    International Nuclear Information System (INIS)

    An experimental method combined with a numerical model allows a comparison of two methods for the disposal of ash that contains arsenic, from the Rio Escondido coal-fired power plant. The calculation yields significant differences in aquifer migration times for the site. The wet disposal method gave 10 years time and the dry method gave 22 years. Experiments were performed on the rate of dissolution of the arsenic from ash samples; and these results indicate a first order kinetics reaction. 8 refs., 8 figs., 8 tabs

  10. Flue gas desulfurization gypsum and fly ash

    International Nuclear Information System (INIS)

    The Cumberland Fossil Plant (CUF) is located in Stewart County, Tennessee, and began commercial operation in 1972. This is the Tennessee Valley Authority's newest fossil (coal-burning) steam electric generating plant. Under current operating conditions, the plant burns approximately seven million tons of coal annually. By-products from the combustion of coal are fly ash, approximately 428,000 tons annually, and bottom ash, approximately 115,000 tons annually. Based on historical load and projected ash production rates, a study was initially undertaken to identify feasible alternatives for marketing, utilization and disposal of ash by-products. The preferred alternative to ensure that facilities are planned for all by-products which will potentially be generated at CUF is to plan facilities to handle wet FGD gypsum and dry fly ash. A number of different sites were evaluated for their suitability for development as FGD gypsum and ash storage facilities. LAW Engineering was contracted to conduct onsite explorations of sites to develop information on the general mature of subsurface soil, rock and groundwater conditions in the site areas. Surveys were also conducted on each site to assess the presence of endangered and threatened species, wetlands and floodplains, archaeological and cultural resources, prime farmland and other site characteristics which must be considered from an environmental perspective

  11. Spreading dynamic of viscous volcanic ash in stimulated jet engine conditions

    Science.gov (United States)

    song, wenjia; Lavallée, Yan; Hess, Kai-Uwe; Kueppers, Ulrich; Cimarelli, Corrado

    2016-04-01

    The ingestion of volcanic ash is widely recognised as a potentially fatal hazard for aircraft operation. The volcanic ash deposition process in a jet turbine is potentially complex. Volcanic ash in the air stream enters the inner liners of the combustors and partially or completely melts under the flames up to 2000 °C, at which point part of the ash deposits in the combustor fuel nozzle. Molten volcanic particles within high energy airflow escape the combustor to enter the turbine and impact the stationary (e.g., inlet nozzle guide vanes) and rotating airfoils (e.g., first stage high-pressure turbine blades) at high speed (up to Mach 1.25) in different directions, with the result that ash may stick, flow and remain liquid or solidify. Thus, the wetting behaviour of molten volcanic ash particle is fundamental to investigate impingement phenomena of ash droplet on the surface of real jet engine operation. The topic of wetting has received tremendous interest from both fundamental and applied points of view. However, due to the interdisciplinary gap between jet engine engineering and geology science, explicit investigation of wetting behaviour of volcanic ash at high temperature is in its infancy. We have taken a big step towards meeting this challenge. Here, we experimentally and theoretically investigate the wetting behaviour of viscous volcanic ash over a wide temperature range from 1100 to 1550 °C using an improved sessile-drop method. The results of our experiment demonstrate that temperature and viscosity play a critical role in determining the wetting possibility and governing the spreading kinetics of volcanic ash at high temperatures. Our systemic analysis of spreading of molten volcanic ash systems allows us to report on the fundamental differences between the mechanisms controlling spreading of organic liquids at room temperature and molten volcanic ash droplets.

  12. Considerations on comprehensive risk assessment and mitigation planning of volcanic ash-fall

    International Nuclear Information System (INIS)

    Volcanic ash-fall is inevitable hazard throughout Japan, and causes wide range of effects due to its physical and chemical properties. Nuclear power plants in Japan face the necessity to assess the risk from volcanic ash-fall. Risk assessment of the volcanic ash-fall should include engineering solution and mitigation planning as well as the ash-fall hazard. This report points out the characteristics for reducing the various effects of volcanic ash-fall as follows. Large-scale eruptions produce prominent volcanic ash-falls that can approach power plants at a great distance. Aftermath hazards of ash-fall events, such as remobilization of fine ash particles and generation of lahars, require further assessments. The kind and extent of damages becomes greater whenever ash is wet. Wet ash requires separate assessments in contrast to dry ash. The mitigation and recovery measures at power plants involve quick cleanup operations of volcanic ash. Those operations should be prepared through comprehensive risk assessment, and by cooperation with authorities, during pre-eruption repose period. The comprehensive assessment for volcanic ash-fall hazards, however, has yet to be conducted. Development of risk communication method may result in increased implementation mitigation planning. Numerical analysis of the ash-fall hazards provides quantitative data on particle motions that can be used in the risk assessment. In order to implement the quantitative assessment method, the verification on the effect of ambient air condition to the altitude of volcanic ash cloud is necessary. We need to develop a three-dimensional model of volcanic ash cloud, and calculate motions of ash clouds under multiple conditions of ambient air. (author)

  13. PERFORMANCE OF ACTIVATED SLUDGE-POWDERED ACTIVATED CARBON-WET AIR REGENERATION SYSTEMS

    Science.gov (United States)

    The investigation summarized in the report was undertaken to evaluate the performance of powdered activated carbon (PAC) technology used in conjunction with wet air regeneration (WAR) at municipal wastewater treatment plants. Excessive ash concentrations accumulated in the mixed ...

  14. Experimental Study on Volume for Fly Ash of Building Block

    Directory of Open Access Journals (Sweden)

    Ling Wang

    2013-04-01

    Full Text Available Fly ash is a waste substance from thermal power plants, steel mills, etc. That is found in abundance in the world. It has polluted the environment, wasting the cultivated land. This study introduces an experimental research on fly ash being reused effectively, the study introduces raw materials of fly ash brick, production process and product inspection, fly ash content could be amounted to 40%~75%. High doping fly ash bricks are manufactured, which selects wet fly ash from the power plants, adding aggregate with reasonable ratio and additives with reasonable dosage and do the experimental research on manufacture products for properties, production technology and selection about technology parameter of production equipment. Index of strength grade and freezing-thawing resisting etc and the high doping fly ash brick building which we are working on can achieve the national standard on building materials industry. Based on the tests, this achievement of research has a very wide practical prospect in using fly ash, industrial waste residue, environmental protection and reducing the cost of enterprises. The efficient reuse of fly ash from coal boiler and power plants has very vital significance of protecting the environment, benefiting descendants and developing of circular economy.

  15. ASH MELTING TEMPERATURE PREDICTION FROM CHEMICAL COMPOSITION OF BIOMASS ASH

    OpenAIRE

    Holubcik, Michal; Jandacka, Jozef; Malcho, Milan

    2015-01-01

    Solid fuels, including biomass, consist of combustible, ash and water. Ash in fuel is result of reaction of minerals presented in the biomass. Minerals and other different substances which form ash got into biomass during growth. Ash is solid residue resulted from the perfect laboratory combustion of fuel. It is composed of minerals that are present in the fuel. Some species of biomass ash have low ash melting temperature and can cause various problems in combustion boilers. Ash slags and sin...

  16. Fly ash carbon passivation

    Science.gov (United States)

    La Count, Robert B; Baltrus, John P; Kern, Douglas G

    2013-05-14

    A thermal method to passivate the carbon and/or other components in fly ash significantly decreases adsorption. The passivated carbon remains in the fly ash. Heating the fly ash to about 500 and 800 degrees C. under inert gas conditions sharply decreases the amount of surfactant adsorbed by the fly ash recovered after thermal treatment despite the fact that the carbon content remains in the fly ash. Using oxygen and inert gas mixtures, the present invention shows that a thermal treatment to about 500 degrees C. also sharply decreases the surfactant adsorption of the recovered fly ash even though most of the carbon remains intact. Also, thermal treatment to about 800 degrees C. under these same oxidative conditions shows a sharp decrease in surfactant adsorption of the recovered fly ash due to the fact that the carbon has been removed. This experiment simulates the various "carbon burnout" methods and is not a claim in this method. The present invention provides a thermal method of deactivating high carbon fly ash toward adsorption of AEAs while retaining the fly ash carbon. The fly ash can be used, for example, as a partial Portland cement replacement in air-entrained concrete, in conductive and other concretes, and for other applications.

  17. Shedding of ash deposits

    DEFF Research Database (Denmark)

    Zbogar, Ana; Frandsen, Flemming; Jensen, Peter Arendt;

    2009-01-01

    Ash deposits formed during fuel thermal conversion and located on furnace walls and on convective pass tubes, may seriously inhibit the transfer of heat to the working fluid and hence reduce the overall process efficiency. Combustion of biomass causes formation of large quantities of troublesome...... ash deposits which contain significant concentrations of alkali, and earth-alkali metals. The specific composition of biomass deposits give different characteristics as compared to coal ash deposits, i.e. different physical significance of the deposition mechanisms, lower melting temperatures, etc....... Low melting temperatures make straw ashes especially troublesome, since their stickiness is higher at lower temperatures, compared to coal ashes. Increased stickiness will eventually lead to a higher collection efficiency of incoming ash particles, meaning that the deposit may grow even faster...

  18. Fly ash: Perspective resource for geo-polymer materials production

    Science.gov (United States)

    Kargin, Aleksey; Baev, Vladimir; Mashkin, Nikolay; Uglyanica, Andrey

    2016-01-01

    The present paper presents the information about the chemical and mineralogical composition of the ash and slag and their amounts at the dumps of the thermoelectric plants located in the city of Kemerovo. It is known that about 85% of ash and slag from the thermoelectric plants in Russia are removed by means of the hydraulic sluicing systems and only about 15% - by the systems of pneumatic ash handling. Currently, however, the transition from the "wet" ash removal systems to the "dry" ones is outlined. This process is quite logical since the fly ash has the higher reactivity compared with the hydraulic sluicing ash and therefore it is of the great interest for recycling and use. On the other hand, the recent trend is the increased use of fly ash in the production of geo-polymers due to their availability, workability and the increased life of the final product. The analysis is carried out to check the possibility of using the fly ash from various Kemerovo thermoelectric plants as a raw material for the production of the alkali-activated binder.

  19. Sulfate resistance of high calcium fly ash concrete

    Science.gov (United States)

    Dhole, Rajaram

    Sulfate attack is one of the mechanisms which can cause deterioration of concrete. In general, Class C fly ash mixtures are reported to provide poor sulfate resistance. Fly ashes, mainly those belonging to the Class C, were tested as per the ASTM C 1012 procedure to evaluate chemical sulfate resistance. Overall the Class C fly ashes showed poor resistance in the sulfate environment. Different strategies were used in this research work to improve the sulfate resistance of Class C fly ash mixes. The study revealed that some of the strategies such as use of low W/CM (water to cementing materials by mass ratio), silica fume or ultra fine fly ash, high volumes of fly ash and, ternary or quaternary mixes with suitable supplementary cementing materials, can successfully improve the sulfate resistance of the Class C fly ash mixes. Combined sulfate attack, involving physical and chemical action, was studied using sodium sulfate and calcium sulfate solutions. The specimens were subjected to wetting-drying cycles and temperature changes. These conditions were found to accelerate the rate of degradation of concrete placed in a sodium sulfate environment. W/CM was found to be the main governing factor in providing sulfate resistance to mixes. Calcium sulfate did not reveal damage as a result of mainly physical action. Characterization of the selected fly ashes was undertaken by using SEM, XRD and the Rietveld analysis techniques, to determine the relation between the composition of fly ashes and resistance to sulfate attack. The chemical composition of glass represented on the ternary diagram was the main factor which had a significant influence on the sulfate resistance of fly ash mixtures. Mixes prepared with fly ashes containing significant amounts of vulnerable crystalline phases offered poor sulfate resistance. Comparatively, fly ash mixes containing inert crystalline phases such as quartz, mullite and hematite offered good sulfate resistance. The analysis of hydrated lime

  20. Modeled Wet Nitrate Deposition

    Data.gov (United States)

    U.S. Environmental Protection Agency — Modeled data on nitrate wet deposition was obtained from Dr. Jeff Grimm at Penn State Univ. Nitrate wet depostion causes acidification and eutrophication of surface...

  1. Introduction to wetting phenomena

    International Nuclear Information System (INIS)

    In these lectures the field of wetting phenomena is introduced from the point of view of statistical physics. The phase transition from partial to complete wetting is discussed and examples of relevant experiments in binary liquid mixtures are given. Cahn's concept of critical-point wetting is examined in detail. Finally, a connection is drawn between wetting near bulk criticality and the universality classes of surface critical phenomena. (author)

  2. Haptic perception of wetness

    NARCIS (Netherlands)

    Bergmann Tiest, W.M.; Kosters, N.D.; Daanen, H.A.M.; Kappers, A.M.L.

    2011-01-01

    The sensation of wetness is well-known but barely investigated. There are no specific wetness receptors in the skin, but the sensation is mediated by temperature and pressure perception. In our study, we have measured discrimination thresholds for the haptic perception of wetness of three di erent t

  3. Ash properties of some dominant Greek forest species

    International Nuclear Information System (INIS)

    The elemental and chemical wood ash compositions of six dominant Greek fuels was investigated using a variety of techniques, including thermal gravimetric analysis (TG), differential thermal analysis (DTA), atomic absorption spectroscopy (AAS) and X-ray diffraction (XRD). In addition, the alkalinity of wood ash was determined by titration. The ash was prepared by combustion at low (600 deg. C), middle (800 deg. C) and high temperatures (1000 deg. C). The ash composition is very important because thousands of hectares of wildlands are burned annually in Greece. The resulting deposits affect soil properties (i.e., pH) and provide a source of inorganic constituents (i.e., Ca, K, Na, Mg, etc.), while the most soluble compounds (i.e., sodium and potassium hydroxides and carbonates) do not persist through the wet season. The samples selected were: Pinus halepensis (Aleppo pine), Pinus brutia (Calabrian pine), Olea europaea (Olive), Cupressus sempervirens (Italian cypress), Pistacia lentiscus (Mastic tree), Quercus coccifera (Holly oak)

  4. PREFACE: Dynamics of wetting Dynamics of wetting

    Science.gov (United States)

    Grest, Gary S.; Oshanin, Gleb; Webb, Edmund B., III

    2009-11-01

    Capillary phenomena associated with fluids wetting other condensed matter phases have drawn great scientific interest for hundreds of years; consider the recent bicentennial celebration of Thomas Young's paper on equilibrium contact angles, describing the geometric shape assumed near a three phase contact line in terms of the relevant surface energies of the constituent phases [1]. Indeed, nearly a century has passed since the seminal papers of Lucas and Washburn, describing dynamics of capillary imbibition [2, 3]. While it is generally appreciated that dynamics of fluid wetting processes are determined by the degree to which a system is out of capillary equilibrium, myriad complications exist that challenge the fundamental understanding of dynamic capillary phenomena. The topic has gathered much interest from recent Nobel laureate Pierre-Gilles de Gennes, who provided a seminal review of relevant dissipation mechanisms for fluid droplets spreading on solid surfaces [4] Although much about the dynamics of wetting has been revealed, much remains to be learned and intrinsic technological and fundamental interest in the topic drives continuing high levels of research activity. This is enabled partly by improved experimental capabilities for resolving wetting processes at increasingly finer temporal, spatial, and chemical resolution. Additionally, dynamic wetting research advances via higher fidelity computational modeling capabilities, which drive more highly refined theory development. The significance of this topic both fundamentally and technologically has resulted in a number of reviews of research activity in wetting dynamics. One recent example addresses the evaluation of existing wetting dynamics theories from an experimentalist's perspective [5]. A Current Opinion issue was recently dedicated to high temperature capillarity, including dynamics of high temperature spreading [6]. New educational tools have recently emerged for providing instruction in wetting

  5. Gas generation in incinerator ash; Gasbildning i aska

    Energy Technology Data Exchange (ETDEWEB)

    Arm, Maria; Lindeberg, Johanna; Rodin, Aasa; Oehrstroem, Anna; Backman, Rainer; Oehman, Marcus; Bostroem, Dan

    2006-02-15

    other reactive metals in addition to aluminium (iron, copper and led were tested), the combination of high total aluminium content of an ash material and low volume of gas generation is possible, since the total aluminium content comprises both the elemental and the non-elemental aluminium and it is only the elemental aluminium that generates gas, aluminium particles can survive incineration without melting and without substantial oxidation of the particle surface, solid aluminium oxide (Al{sub 2}O{sub 3}) is the stable form of aluminium in a boiler. Based on the results in this project the following recommendations for handling the ash can be given to decrease the gas generation and to prevent the risk for explosion: The content of elemental aluminium or the potential of gas generation should be analysed regularly for ash materials from municipal waste incineration plants; Metal separation - including non-magnetic metals - of the fuel for waste incineration plants is necessary; Good ventilation of the ash after wetting, together with storage in oxygen rich environment is desirable.

  6. Wetting in electrolyte solutions.

    Science.gov (United States)

    Ibagon, Ingrid; Bier, Markus; Dietrich, S

    2013-06-01

    Wetting of a charged substrate by an electrolyte solution is investigated by means of classical density functional theory applied to a lattice model. Within the present model the pure, i.e., salt-free solvent, for which all interactions are of the nearest-neighbor type only, exhibits a second-order wetting transition for all strengths of the substrate-particle and the particle-particle interactions for which the wetting transition temperature is nonzero. The influences of the substrate charge density and of the ionic strength on the wetting transition temperature and on the order of the wetting transition are studied. If the substrate is neutral, the addition of salt to the solvent changes neither the order nor the transition temperature of the wetting transition of the system. If the surface charge is nonzero, upon adding salt this continuous wetting transition changes to first-order within the wide range of substrate surface charge densities and ionic strengths studied here. As the substrate surface charge density is increased, at fixed ionic strength, the wetting transition temperature decreases and the prewetting line associated with the first-order wetting transition becomes longer. This decrease of the wetting transition temperature upon increasing the surface charge density becomes more pronounced by decreasing the ionic strength. PMID:23758391

  7. HIS 204 ASH Course Tutorial / Tutorialoutlet

    OpenAIRE

    JOHN

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   HIS 204 Week 1 DQ 1 (Ash) HIS 204 Week 1 DQ 2 (Ash) HIS 204 Week 1 Quiz (Ash) HIS 204 Week 2 DQ 1 (Ash) HIS 204 Week 2 DQ 2 (Ash) HIS 204 Week 2 Quiz (Ash) HIS 204 Week 3 Assignment Women Right, Sacrifices & Independence (Ash) HIS 204 Week 3 DQ 1 (Ash) HIS 204 Week 3 DQ 2 (Ash) HIS 204 Week 4 DQ 1 (Ash) HIS 204 Week 4 DQ 2 (Ash) HIS 204 Week 4 Quiz (Ash) HIS 204 Week 5 DQ 1 (Ash) ...

  8. Wet oxidation of quinoline

    DEFF Research Database (Denmark)

    Thomsen, A.B.; Kilen, H.H.

    1998-01-01

    The influence of oxygen pressure (0.4 and 2 MPa). reaction time (30 and 60 min) and temperature (260 and 280 degrees C) on the wet oxidation of quinoline has been studied. The dominant parameters for the decomposition of quinoline were oxygen pressure and reaction temperature. whereas the reaction...... time was less important within the range studied. Nitrifying bacteria were used to measure the inhibition from wet oxidative-treated samples to study the effect of the (wet oxidation) reaction conditions. Wet oxidation made quinoline more toxic to Nitrosomonas. This was observed for Nitrobacter as well....... The combined wet oxidation and biological treatment of reaction products resulted in 91% oxidation of the parent compound to CO2 and water. Following combined wet oxidation and biological treatment the sample showed low toxicity towards Nitrosomonas and no toxicity towards Nitrobacter. (C) 1998 Elsevier...

  9. Re-burning of ash in grate boilers; Omfoerbraenning av askor i rosterpannor

    Energy Technology Data Exchange (ETDEWEB)

    Bergqvist, Kristina; Myringer, Aase; Nordgren, Daniel; Rydberg, Stina [Vattenfall Utveckling AB, Aelvkarleby (Sweden)

    2005-03-01

    High contents of unburnt carbon in ashes that are dumped or recycled, is questionable from both an economical and an environmental point of view. The content of unburnt carbon in bottom and fly ash from grate boilers varies greatly between different plants but can sometimes exceed 50 %. Re-burning of ash that is separated before a final dust separation, is a relatively cheep and simple method for reducing the content of unburnt carbon in ash, which both reduces the fuel cost and the deposit cost, i.e. the cost of landfilling or recycling. As from 2005 it is prohibited to deposit ash with a too high content of unburnt organic material; the content is limited to 18 weight % of unburnt carbon. The study was carried out in two phases. The aim of the first phase was to map the different techniques used for re-burning ash that are used in grate boilers today. The mapping was done through telephone interviews and comprises technical descriptions of the systems, gathering of operational know-how, installations costs and the effect of the systems on the amount of ash generated at the plants and the content of unburnt carbon in the ash. In order to accomplish a deeper technical and economical evaluation of ash re-burning systems, the second phase involved field studies at two plants. In addition screening tests were done to investigate the connection between the content of unburnt carbon and particle size. The potential of reducing the amount of circulated inorganic material by sieving the ash before bringing it back to the furnace could thereby be determined. 13 plants that utilize re-burning of ash were identified, of which two plants re-burn the bottom ash that floats up to the surface in the wet ash removal system. The remaining 11 plants re-burn fly ash. At three plants the fly ash is first separated in a mesh sieve or similar equipment and only the coarser fly ash is re-burnt. As the amount of bottom ash that surfaces in the wet ash-removal is relatively small

  10. Wet Gas Compressor Performance

    OpenAIRE

    Natås, Erik

    2014-01-01

    The world’s energy demand is increasing and more attention is given to increase the recovery of gas fields. Installing a compressor near the wellhead can contribute to this. Constantly changing reservoir conditions requires the system to handle small amounts of liquid water and condensate. Wet gas compression is a cost efficient and compact alternative to liquid separation on the seabed. A wet gas compressor test facility exists at NTNU`s thermal laboratory and research on wet gas fundam...

  11. Screening of Surface Medication Agents and Modification Mechanism of Fly Ash

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong-bo; WEI Lu-bin

    2007-01-01

    The fly ash from Jixi power plant was treated with various surface modifiers. The surface properties of the modified fly ash, including active index wetting angle, were measured in this paper. The modified fly ash was filled into rubber to improve the rubber properties. The results of rubber tests indicate that the type of the surface modifiers has a great influence on the rubber reinforcing properties. The fly ash modified by titanate coupling agents exhibits the best performance in respect to rubber reinforcing properties. The test results show that the fly ash can take place of some decomposition material so that the dosage of decomposition in rubber can be reduced, resulting in the low producing cost of rubber and the low pollution of fly ash.

  12. Fusion characterization of biomass ash

    DEFF Research Database (Denmark)

    Ma, Teng; Fan, Chuigang; Hao, Lifang;

    2016-01-01

    The ash fusion characteristics are important parameters for thermochemical utilization of biomass. In this research, a method for measuring the fusion characteristics of biomass ash by Thermo-mechanical Analyzer, TMA, is described. The typical TMA shrinking ratio curve can be divided into two...... stages, which are closely related to ash melting behaviors. Several characteristics temperatures based on the TMA curves are used to assess the ash fusion characteristics. A new characteristics temperature, Tm, is proposed to represent the severe melting temperature of biomass ash. The fusion...... characteristics of six types of biomass ash have been measured by TMA. Compared with standard ash fusibility temperatures (AFT) test, TMA is more suitable for measuring the fusion characteristics of biomass ash. The glassy molten areas of the ash samples are sticky and mainly consist of K-Ca-silicates....

  13. Melting and Sintering of Ashes

    DEFF Research Database (Denmark)

    Hansen, Lone Aslaug

    1997-01-01

    of melt in the investigated ashes has been determined as a function of temperature. Ash fusion results have been correlated to the chemical and mineralogical composition of the ashes, to results from a standard ash fusion test and to results from sintering experiments. Furthermore, the ash fusion results...... straw combustion are characterised by a large fraction of KCl and a smaller fraction of K-, Ca-, Al-silicates and quartz. The salt part of these ashes melt in the temperature range from 600-750°C, whereas the silicate part predominantly melts between 1000 and 1200°C. Increasing salt (KCl) content...... in the ashes lead to increased melt fractions in the temperature range 600-750°C.b) Bottom ashes from straw combustion consist purely of silicates, with varying ratios of the quite refractory Al-silicates and quartz to the less refractory K- and Ca-silicates. Bottom ashes melt in the temperature range 800...

  14. Wet Gas Compressor Transients

    OpenAIRE

    Owren, Bjørn Berge

    2014-01-01

    This master thesis considers three subtasks related to transient operation of wet gas compressors.HYSYS Dynamics is used to establish a dynamic simulation model in the first subtask. The model is designed to predict transient behavior of the compressor test facility at NTNU during dry and wet gas trip scenarios. Its steady state performance has been validated against test data. The deviation of polytropic head and suction volume flow is less than 1% for all test points but one.Dry and wet gas...

  15. MAT 126 ASH Course Tutorial / Tutorialoutlet

    OpenAIRE

    stylia

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   MAT 126 Week 1 DQ 1 (Ash) MAT 126 Week 1 Quiz (Ash) MAT 126 Week 1 Written Assignment (Arithmetic and geometric sequence) (Ash) MAT 126 Week 2 DQ 1 (Ash) MAT 126 Week 2 DQ 2 (Ash) MAT 126 Week 2 Assignment Is It Fat Free (Ash) MAT 126 Week 2 Quiz (Ash) MAT 126 Week 3 DQ 1 (Ash) MAT 126 Week 3 DQ 2 (Ash) MAT 126 Week 3 Assignment Quadratic Equations (Ash) MAT 126 Week 3 Quiz (Ash) MAT 126...

  16. Adsorption and wetting.

    NARCIS (Netherlands)

    Schlangen, L.J.M.

    1995-01-01

    Adsorption and wetting are related phenomena. In order to improve knowledge of both and their relations, experiments, thermodynamics and a theoretical interpretation have been connected, starring n-alkanes.Starting from the Gibbs adsorption equation thermodynamic relations between vapour adsorption

  17. Wetting of soluble polymers

    OpenAIRE

    Dupas, Julien

    2012-01-01

    The wetting of a soluble substrate is a situation commonly encountered in day-to-day life. For instance, the practical motivation of this study concerns the preparation of beverages using dehydrated powders, consisting of water-soluble substances such as carbohydrates. Hydrodynamical theories describing wetting onto insoluble substrates cannot account for experimental observations in the case of a liquid spreading onto a soluble substrate. Tay et al.(1) made the hypothesis that the water cont...

  18. Adsorption and wetting.

    OpenAIRE

    Schlangen, L.J.M.

    1995-01-01

    Adsorption and wetting are related phenomena. In order to improve knowledge of both and their relations, experiments, thermodynamics and a theoretical interpretation have been connected, starring n-alkanes.Starting from the Gibbs adsorption equation thermodynamic relations between vapour adsorption and wetting are derived. The surface pressure of a film, formed by vapour adsorption on a solid surface, is calculated by integrating the vapour adsorption isotherm. The surface pressure at the sat...

  19. Electrodialytic treatment of fly ash

    DEFF Research Database (Denmark)

    Jensen, Pernille Erland; Pedersen, Anne Juul; Kirkelund, Gunvor Marie; Ottosen, Lisbeth M.

    Heavy metals are removed from the fly ashes by an electrodialytic treatment with the aim of up-grading the ashes for reuse in stead of disposal in landfill.A great potential for upgrading of bio- and waste incineration ashes by electrodialytic treatment exists. In the future, the applicability of...

  20. How safe is fly ash as building construction material in dwellings

    International Nuclear Information System (INIS)

    Fly ash generated from conventional coal based power plants is disposed off in ash ponds in the form of wet- slurries and is being used as stowing material for underground coal mines, for manufacturing bricks, asbestos sheets, Portland Pozzolona ct-Hlent, land filling etc. In the recent past, there has been increasing interest in making fly ash brick houses due to light wt. of the bricks particularly in hilly areas and earth quake prone areas. It was lesser known hitherto until recently that the fly ash is a potential radioactive air pollutant and it modifies radiation exposure. As the fly ash is burnt coal ash and contains concentrated amount of radionuclides, tracking radon concentration in it is thus fundamental for radiation protection, health and hygiene point of view. Measurement of indoor radon and its progeny levels was carried out in dwellings made up of fly ash bricks using LR-115, Type II plastic track detectors. The measurements indicate moderate to high levels of radon concentration in fly ash samples in itself and fly ash brick houses. For comparison the radon concentration in some typical dwellings made up of Baked Mud Bricks, concrete blocks and mud houses was also carried out. (author)

  1. ASH and NASH.

    Science.gov (United States)

    Scaglioni, F; Ciccia, S; Marino, M; Bedogni, G; Bellentani, S

    2011-01-01

    Non-alcoholic steatohepatitis (NASH) and alcoholic steatohepatitis (ASH) have a similar pathogenesis and histopathology but a different etiology and epidemiology. NASH and ASH are advanced stages of non-alcoholic fatty liver disease (NAFLD) and alcoholic fatty liver disease (AFLD). NAFLD is characterized by excessive fat accumulation in the liver (steatosis), without any other evident causes of chronic liver diseases (viral, autoimmune, genetic, etc.), and with an alcohol consumption ≤20-30 g/day. On the contrary, AFLD is defined as the presence of steatosis and alcohol consumption >20-30 g/day. The most common phenotypic manifestations of primary NAFLD/NASH are overweight/obesity, visceral adiposity, type 2 diabetes, hypertriglyceridemia and hypertension. The prevalence of NAFLD in the general population in Western countries is estimated to be 25-30%. The prevalence and incidence of NASH and ASH are not known because of the impossibility of performing liver biopsy in the general population. Up to 90% of alcoholics have fatty liver, and 5-15% of these subjects will develop cirrhosis over 20 years. The risk of cirrhosis increases to 30-40% in those who continue to drink alcohol. About 10-35% of alcoholics exhibit changes on liver biopsy consistent with alcoholic hepatitis. Natural histories of NASH and ASH are not completely defined, even if patients with NASH have a reduced life expectancy due to liver-related death and cardiovascular diseases. The best treatment of AFLD/ASH is to stop drinking, and the most effective first-line therapeutic option for NAFLD/NASH is non-pharmacologic lifestyle interventions through a multidisciplinary approach including weight loss, dietary changes, physical exercise, and cognitive-behavior therapy. PMID:21734385

  2. Geochemically structural characteristics of municipal solid waste incineration fly ash particles and mineralogical surface conversions by chelate treatment.

    Science.gov (United States)

    Kitamura, Hiroki; Sawada, Takaya; Shimaoka, Takayuki; Takahashi, Fumitake

    2016-01-01

    Leaching behaviors of heavy metals contained in municipal solid waste incineration (MSWI) fly ash have been studied well. However, micro-characteristics of MSWI fly ash particles are still uncertain and might be non-negligible to describe their leaching behaviors. Therefore, this study investigated micro-characteristics of MSWI fly ash particles, especially their structural properties and impacts of chelate treatment on surface characteristics. According to SEM observations, raw fly ash particles could be categorized into four types based on their shapes. Because chelate treatment changed the surface of fly ash particles dramatically owing to secondary mineral formations like ettringite, two more types could be categorized for chelate-treated fly ash particles. Acid extraction experiments suggest that fly ash particles, tested in this study, consist of Si-base insoluble core structure, Al/Ca/Si-base semi-soluble matrices inside the body, and KCl/NaCl-base soluble aggregates on the surface. Scanning electron microscope (SEM) observations of the same fly ash particles during twice moistening treatments showed that KCl/NaCl moved under wet condition and concentrated at different places on the particle surface. However, element mobility depended on secondary mineral formations. When insoluble mineral like gypsum was generated and covered the particle surface, it inhibited element transfer under wet condition. Surface characteristics including secondary mineral formation of MSWI fly ash particles are likely non-negligible to describe trace element leaching behaviors. PMID:26336844

  3. MGT 330 ASH Course Tutorial / Tutorialoutlet

    OpenAIRE

    alfoniz

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   MGT 330 Week 1 Individual Assignment Functions of Management Paper (Ash) MGT 330 Week 1 DQ 1 (Ash) MGT 330 Week 1 DQ 2 (Ash) MGT 330 Week 1 DQ 3 (Ash) MGT 330 Week 1 Summary (Ash) MGT 330 Week 2 Team Assignment External Internal Factors Paper (Ash) MGT 330 Week 2 Individual Assignment Delegation (Ash) MGT 330 Week 2 Summary (Ash) MGT 330 Week 2 DQ 1 (Ash) MGT 330 Week 2 DQ 2 (Ash) MGT 330 W...

  4. Establishment of trees on minesoils during drought and wet years

    International Nuclear Information System (INIS)

    In two studies, green ash (Fraxinus pennsylvania) and white pine (Pinus strobus) were planted on three minesoils (graded topsoil, ripped topsoil, and gray cast overburden). Mixtures of grasses and/or legumes were seeded at different times in relation to tree planting. In the first study, tree planting was followed by several week of drought; in the second, precipitation was above average for the first two growing seasons following planting. In the drought year, survival of green ash was influenced by minesoil type, herbaceous mixture, and herbaceous seeding time in relation to tree planting. Among minesoils, mean survival was highest (87%) on cast overburden. Seeding grasses the fall before planting resulted in poor ash survival (40% to 47%) compared with seeding at time of planting (82% to 85%). Ash survived well (81% to 94%) on legume-seeded plots. When tree planting was followed by two wet seasons, survival at 4 and 5 yr ranged from very good to excellent in all treatments. Total height of ash trees on cast overburden averaged 31% less than that of trees on topsoil, and 29% greater on legume-seeded subplots than trees on grass subplots, although herbaceous biomass was greater on legume subplots. The three minesoils proved unsuitable for white pine. 17 refs., 7 tabs

  5. A seasonal assessment of the impact of coal fly ash disposal on the River Yamuna, Delhi. I. Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Walia, A.; Mehra, N.K. [University of Delhi, Delhi (India). Dept. of Zoology

    1998-04-01

    The impact of fly ash on the chemistry of the River Yamuna was studied. By-products from a 200 MW capacity Indraprasha thermal power station on the west bank of the River Yamuna, Delhi are largely from coal combustion (fly ash) and are disposed of as a slurry in off-site ash ponds. Many elements associated with fly ash are soluble and become available to the biota. A two-year survey was made of the seasonal variations in limnochemical features in the non-impacted and the impacted segments of the river receiving fly ash effluent and the ash treatment ponds. Conductivity, TDS, DO, hardness, sulphate and nitrate increased significantly in the receiving waters over background values. The reverse was noticed for free CO{sub 2}, alkalinity and phosphate. Changes in some other parameters were insignificant. Fly ash effluent from the ash ponds significantly increased the concentration of some elements, viz., Al, Sb, Bi, Cd, Co, Cr, Li, Mn, Mo, K, Si and Zn in river water. Generally, the highest concentration of most parameters were recorded in the ash ponds. This investigation was helpful in assessing the effect of wet ash disposal on the river limnology and understanding the solubility of various elements in the ash ponds. 50 refs., 6 figs., 1 tab.

  6. A seasonal assessment of the impact of coal fly ash disposal on the River Yamuna, Delhi. I. Chemistry

    International Nuclear Information System (INIS)

    The impact of fly ash on the chemistry of the River Yamuna was studied. By-products from a 200 MW capacity Indraprasha thermal power station on the west bank of the River Yamuna, Delhi are largely from coal combustion (fly ash) and are disposed of as a slurry in off-site ash ponds. Many elements associated with fly ash are soluble and become available to the biota. A two-year survey was made of the seasonal variations in limnochemical features in the non-impacted and the impacted segments of the river receiving fly ash effluent and the ash treatment ponds. Conductivity, TDS, DO, hardness, sulphate and nitrate increased significantly in the receiving waters over background values. The reverse was noticed for free CO2, alkalinity and phosphate. Changes in some other parameters were insignificant. Fly ash effluent from the ash ponds significantly increased the concentration of some elements, viz., Al, Sb, Bi, Cd, Co, Cr, Li, Mn, Mo, K, Si and Zn in river water. Generally, the highest concentration of most parameters were recorded in the ash ponds. This investigation was helpful in assessing the effect of wet ash disposal on the river limnology and understanding the solubility of various elements in the ash ponds. 50 refs., 6 figs., 1 tab

  7. Ash Properties of Alternative Biomass

    DEFF Research Database (Denmark)

    Capablo, Joaquin; Jensen, Peter Arendt; Pedersen, Kim Hougaard;

    2009-01-01

    The ash behavior during suspension firing of 12 alternative solid biofuels, such as pectin waste, mash from a beer brewery, or waste from cigarette production have been studied and compared to wood and straw ash behavior. Laboratory suspension firing tests were performed on an entrained flow...... reactor and a swirl burner test rig, with special emphasis on the formation of fly ash and ash deposit. Thermodynamic equilibrium calculations were performed to support the interpretation of the experiments. To generalize the results of the combustion tests, the fuels are classified according to fuel ash...... analysis into three main groups depending upon their ash content of silica, alkali metal, and calcium and magnesium. To further detail the biomass classification, the relative molar ratio of Cl, S, and P to alkali were included. The study has led to knowledge on biomass fuel ash composition influence on...

  8. Uncertainty in volcanic ash cloud forecasting: sources and quantification (Invited)

    Science.gov (United States)

    Folch, A.

    2013-12-01

    Volcanic ash clouds formed during explosive volcanic eruptions can disperse in the atmosphere over larger distances jeopardizing aerial navigation. The trajectories and extent of ash clouds are forecasted operationally coupling atmospheric transport and numerical weather prediction models. The major uncertainties in simulations come from wind fields, eruption source parameters (eruption rate, vertical distribution of ash in the atmosphere and particle granulometry) and removal processes (ash aggregation, wet and dry deposition mechanisms). The global air traffic disruptions following the 2010 and 2011 eruptions of Eyjafjallajökull and Cordón Caulle forced a revision of the modelling approaches in order to provide a more robust and reliable response to the social needs. Strategies to reduce and quantify uncertainties are being introduced at both research and operational levels, including data assimilation, ensemble modelling and probabilistic forecasts. This requires collaboration amongst volcanological and meteorological communities. Initiatives such as the 2nd IUGG-WMO workshop on ash dispersal forecast and civil aviation (Geneva, 18-20 November 2013) help to develop strategies for a closer working relationship and further collaboration amongst scientific communities and between scientists and aviation industry and other stakeholders.

  9. “Technical Properties of Pond Ash - Clay Fired Bricks – An Experimental Study”

    Directory of Open Access Journals (Sweden)

    Prashant G. Sonawane

    2013-09-01

    Full Text Available In the thermal power plants the coal is burnt to heat the water for making the steam, which in turn is used to run the turbines. The pond ash is a waste product from the boilers. It is mainly obtained from the wet disposal of the fly ash, which when get mixed with bottom ash is disposed off in large pond or dykes as slurry. The pond ash is being generated in an alarming rate. The generation of the pond ash is posing a lot of threat to environment and thus its sustainable management has become the thrust area in engineering research. As the pond ash is relatively coarse and the dissolvable alkalies present in it are washed with water, its pozzolanic reactivity becomes low and hence it is not preferred as part replacement of cement in concrete as in the case of fly ash. In this research work an attempt is made to find out the possibility of using pond ash in burnt clay bricks. The part of the clay is replaced by pond ash in different composition and the bricks are made in conventional method at a brick manufacturing plant. The bricks are fired in a traditional way as per usual practice in the area and the final products with different composition of pond ash are tested in laboratory; for tolerance in dimension, water absorption, compressive strength, initial rate of absorption and weathering. The results of all the tests on brick samples with different % of pond ash are compared with clay bricks and the effect on different characteristics of bricks due to addition of pond ash are studied.

  10. Wet storage integrity update

    International Nuclear Information System (INIS)

    This report includes information from various studies performed under the Wet Storage Task of the Spent Fuel Integrity Project of the Commercial Spent Fuel Management (CSFM) Program at Pacific Northwest Laboratory. An overview of recent developments in the technology of wet storage of spent water reactor fuel is presented. Licensee Event Reports pertaining to spent fuel pools and the associated performance of spent fuel and storage components during wet storage are discussed. The current status of fuel that was examined under the CSFM Program is described. Assessments of the effect of boric acid in spent fuel pool water on the corrosion and stress corrosion cracking of stainless steel and the stress corrosion cracking of stainless steel piping containing stagnant water at spent fuel pools are discussed. A list of pertinent publications is included. 84 references, 21 figures, 11 tables

  11. MAT 221 ASH Course Tutorial / Tutorialoutlet

    OpenAIRE

    mirat

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   MAT 221 Week 1 Assignment 1 Simplifying Expressions (Ash) MAT 221 Week 1 DQ 1 Evaluating Algebraic Expressions (Ash) MAT 221 Week 2 Assignment 2 Inequalities (Ash) MAT 221 Week 2 DQ 1 Formulas (Ash) MAT 221 Week 3 Assignment 3 Two-Variable Inequality (Ash) MAT 221 Week 3 DQ 1 Parallel and Perpendicular (Ash) MAT 221 Week 4 Assignment 4 Financial Polynomials (Ash) MAT 221 Week 4 DQ 1 Initial Investme...

  12. Wet flue gas desulphurization and new fuels

    Energy Technology Data Exchange (ETDEWEB)

    Kiil, S.; Dam-Johansen, K.; Michelsen, M.L.

    1998-04-01

    This thesis describes experimental and theoretical investigations of wet flue gas desulphurization (FGD). A review of the current knowledge of the various rate determining steps in wet FDG plants is presented. The mechanism underlying the rate of dissolution of finely grained limestone particles was examined in a laboratory batch apparatus using acid titration. Three Danish limestones of different origin were tested. A transient, mass transport controlled, mathematical model was developed to describe the dissolution process. Model predictions were found to be qualitatively in good agreement with experimental data. Empirical correlations for the dimensionless mass transfer coefficients in a pilot plant (falling-film column) were determined. The presence of inert particles in the liquid phase was found to decrease the rate of gas phase mass transport with up to 15%, though the effect could not be correlated. A detailed model for a wet FGD pilot plant, based on the falling film principle, was developed. All important rate determining steps, absorption of SO{sub 2}, oxidation of HSO{sub 3}{sup -}, dissolution of limestone, and crystallisation of gypsum were included. Model predictions were compared to experimental data such as gas phase concentration profiles of SO{sub 2}, slurry pH-profiles, solids contents of slurry, liquid phase concentrations, and residual limestone in the gypsum. The possibility of co-firing straw and coal was investigated in a full-scale power plant. No effects on the overall performance of the wet FGD plant were observed, though laboratory experiments with fine dust and fly ash from the full-scale experiments showed a decrease in limestone reactivity. (EG) EFP-95. 45 refs.; Also ph.d. thesis of Soeren Kiil

  13. Incineration ash conditioning processes

    International Nuclear Information System (INIS)

    Incinerable wastes consist of the following standard composition corresponding to projected wastes from a future mixed oxide fuel fabrication plant with an annual throughput of 1700 kg (i.e. 5.7 m3) of ashes produced by the incineration facility: . 50% polyvinyl chloride (glove box sleeves), . 5% polyethylene (bags), . 35% rubber (equal amounts of latex and neoprene), . 10% cellulose (equal amounts of cotton and cleansing tissues). The work focused mainly on compaction by high-temperature isostatic pressing, is described in some detail with the results obtained. An engineering study was also carried out to compare this technology with two other ash containment processes: direct-induction (cold crucible) melting and cement-resin matrix embedding. Induction melting is considerably less costly than isostatic pressing; the operating costs are about 1.5 times higher than for cement-resin embedding, but the volume reduction is nearly 3 times greater

  14. Volcanic ash melting under conditions relevant to ash turbine interactions.

    Science.gov (United States)

    Song, Wenjia; Lavallée, Yan; Hess, Kai-Uwe; Kueppers, Ulrich; Cimarelli, Corrado; Dingwell, Donald B

    2016-01-01

    The ingestion of volcanic ash by jet engines is widely recognized as a potentially fatal hazard for aircraft operation. The high temperatures (1,200-2,000 °C) typical of jet engines exacerbate the impact of ash by provoking its melting and sticking to turbine parts. Estimation of this potential hazard is complicated by the fact that chemical composition, which affects the temperature at which volcanic ash becomes liquid, can vary widely amongst volcanoes. Here, based on experiments, we parameterize ash behaviour and develop a model to predict melting and sticking conditions for its global compositional range. The results of our experiments confirm that the common use of sand or dust proxy is wholly inadequate for the prediction of the behaviour of volcanic ash, leading to overestimates of sticking temperature and thus severe underestimates of the thermal hazard. Our model can be used to assess the deposition probability of volcanic ash in jet engines. PMID:26931824

  15. Volcanic ash melting under conditions relevant to ash turbine interactions

    Science.gov (United States)

    Song, Wenjia; Lavallée, Yan; Hess, Kai-Uwe; Kueppers, Ulrich; Cimarelli, Corrado; Dingwell, Donald B.

    2016-03-01

    The ingestion of volcanic ash by jet engines is widely recognized as a potentially fatal hazard for aircraft operation. The high temperatures (1,200-2,000 °C) typical of jet engines exacerbate the impact of ash by provoking its melting and sticking to turbine parts. Estimation of this potential hazard is complicated by the fact that chemical composition, which affects the temperature at which volcanic ash becomes liquid, can vary widely amongst volcanoes. Here, based on experiments, we parameterize ash behaviour and develop a model to predict melting and sticking conditions for its global compositional range. The results of our experiments confirm that the common use of sand or dust proxy is wholly inadequate for the prediction of the behaviour of volcanic ash, leading to overestimates of sticking temperature and thus severe underestimates of the thermal hazard. Our model can be used to assess the deposition probability of volcanic ash in jet engines.

  16. Ashes for organic farming

    OpenAIRE

    Kousa, T.; Heinonen, M; Suoniitty, T.; Peltonen, K

    2013-01-01

    Nowadays only eight percent of the cultivated field area is used for organic farming. The Ministry of Agriculture and Forestry has published the guidelines for the program of organic farming to diversify the supply and the consumption of organic food. The aim is to increase organically arable land to 20% by the year 2020.The demand of organic fertilizer products is strongly increasing. Interest in forestry by-products (ash, bark, zero fiber, etc.) for use in organic production has recently be...

  17. Ash Management Review—Applications of Biomass Bottom Ash

    Directory of Open Access Journals (Sweden)

    Harpuneet S. Ghuman

    2012-10-01

    Full Text Available In industrialized countries, it is expected that the future generation of bioenergy will be from the direct combustion of residues and wastes obtained from biomass. Bioenergy production using woody biomass is a fast developing application since this fuel source is considered to be carbon neutral. The harnessing of bioenergy from these sources produces residue in the form of ash. As the demand for bioenergy production increases, ash and residue volumes will increase. Major challenges will arise relating to the efficient management of these byproducts. The primary concerns for ash are its storage, disposal, use and the presence of unburned carbon. The continual increase in ash volume will result in decreased ash storage facilities (in cases of limited room for landfill expansion, as well as increased handling, transporting and spreading costs. The utilization of ash has been the focus of many studies, hence this review investigates the likely environmental and technological challenges that increased ash generation may cause. The presence of alkali metals, alkaline earth metals, chlorine, sulphur and silicon influences the reactivity and leaching to the inorganic phases which may have significant impacts on soils and the recycling of soil nutrient. Discussed are some of the existing technologies for the processing of ash. Unburned carbon present in ash allows for the exploration of using ash as a fuel. The paper proposes sieve fractionation as a suitable method for the separation of unburnt carbon present in bottom ash obtained from a fixed-bed combustion system, followed by the application of the gasification technology to particle sizes of energy importance. It is hoped that this process will significantly reduce the volume of ash disposed at landfills.

  18. Evaluatie wet op orgaandonatie

    OpenAIRE

    Rosendal, H.; Beekum, W.T. van; Legemaate, J.; Buisen, M.A.J.M.; Hulst, E.H.; Berg, M. van den; Assink, A.; Veen, E.B. van; Davidse, W.; Swagerman, M.B.; Chorus, A.M.J.; Brodin, H.F.T.; Riet, A. van 't; van Dijk, P.

    2001-01-01

    Met de invoering van de Wet op de orgaandonatie (WOD) is een viertal doelen nagestreefd, namelijk het bieden van rechtszekerheid aan betrokkenen, het bevorderen van het aanbod van geschikte organen en weefsels, een rechtvaardige verdeling hiervan en het voorkomen van handel in organen en weefsels. De onderzoekers concluderen dat bovengenoemde doelen ten dele zijn gerealiseerd.

  19. Wetting of real surfaces

    CERN Document Server

    Bormashenko, Edward Yu

    2013-01-01

    The problem of wetting and drop dynamics on various surfaces is very interesting from both the scientificas well as thepractical viewpoint, and subject of intense research.The results are scattered across papers in journals, sothis workwill meet the need for a unifying, comprehensive work.

  20. Wet hydrate dissolution plant

    Directory of Open Access Journals (Sweden)

    Stanković Mirjana S.

    2003-01-01

    Full Text Available The IGPC Engineering Department designed basic projects for a wet hydrate dissolution plant, using technology developed in the IGPC laboratories. Several projects were completed: technological, machine, electrical, automation. On the basis of these projects, a production plant with capacity of 50,000 t/y was manufactured, at "Zeolite Mira", Mira (VE, Italy, in 1997, for increasing detergent zeolite production from 50,000 to 100,000 t/y. Several goals were realized by designing a wet hydrate dissolution plant. Main goal was increasing the detergent zeolite production capacity. The technological cycle of NaOH was closed, and no effluents emitted, and there is no pollution. Wet hydrate dissolution is now fully continuous, which is important for maintaining zeolite production quality, as well as for simplifying production. The wet hydrate production process is fully automatized, and the product has uniform quality. The production process can be controlled manually, which is necessary during start-up, and repairs. By installing additional process equipment (centrifugal pumps and dissolving reactors technological bottlenecks were overcome, and by adjusting NaOH tanks and dissolving reactors, the capacities of the process equipment was fully utilized.

  1. Melting Behavior of Volcanic Ash relevant to Aviation Ash Hazard

    Science.gov (United States)

    Song, W.; Hess, K.; Lavallee, Y.; Cimarelli, C.; Dingwell, D. B.

    2013-12-01

    Volcanic ash is one of the major hazards caused by volcanic eruptions. In particular, the threat to aviation from airborne volcanic ash has been widely recognized and documented. In the past 12 years, more than 60 modern jet airplanes, mostly jumbo jets, have been damaged by drifting clouds of volcanic ash that have contaminated air routes and airport facilities. Seven of these encounters are known to have caused in-flight loss of engine power to jumbo jets carrying a total of more than 2000 passengers. The primary cause of engine thrust loss is that the glass in volcanic ash particles is generated at temperatures far lower than the temperatures in the combustion chamber of a jet engine ( i.e. > 1600 oC) and when the molten volcanic ash particles leave this hottest section of the engine, the resolidified molten volcanic ash particles will be accumulated on the turbine nozzle guide vanes, which reduced the effective flow of air through the engine ultimately causing failure. Thus, it is essential to investigate the melting process and subsequent deposition behavior of volcanic ash under gas turbine conditions. Although few research studies that investigated the deposition behavior of volcanic ash at the high temperature are to be found in public domain, to the best our knowledge, no work addresses the formation of molten volcanic ash. In this work, volcanic ash produced by Santiaguito volcano in Guatemala in November 8, 2012 was selected for study because of their recent activity and potential hazard to aircraft safety. We used the method of accessing the behavior of deposit-forming impurities in high temperature boiler plants on the basis of observations of the change in shape and size of a cylindrical coal ash to study the sintering and fusion phenomena as well as determine the volcanic ash melting behavior by using characteristic temperatures by means of hot stage microscope (HSM), different thermal analysis (DTA) and Thermal Gravimetric Analysis (TGA) to

  2. INF 325 ASH Course Tutorial / Tutorialoutlet

    OpenAIRE

    SINDHU

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com INF 325 Week 1 DQ 1 Network Management (Ash) INF 325 Week 1 DQ 2 Ethernet Network (Ash) INF 325 Week 1 Commercial Internet Expansion (Ash) INF 325 Week 2 DQ 1 UTP Cord Problem (Ash) INF 325 Week 2 DQ 2 Managed Switches (Ash) INF 325 Week 2 Leased Lines (Ash) INF 325 Week 3 DQ 1 WPA (Ash) INF 325 Week 3 DQ 2 Remote Access Management (Ash) INF 325 Week 3 Mobile Service (Ash) INF 325 Week 4 DQ 1 Ro...

  3. INF 336 ASH Course Tutorial / Tutorialoutlet

    OpenAIRE

    MADURA

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com INF 336 Week 1 DQ 1 Risk Management (Ash) INF 336 Week 1 DQ 2 Organizational Structure (Ash) INF 336 Week 2 DQ 1 Supply Process Improvements (Ash) INF 336 Week 2 DQ 2 Outsourcing (Ash) INF 336 Week 2 Assignment Article Review (Ash) INF 336 Week 3 DQ 1 Capital Goods (Ash) INF 336 Week 3 DQ 2 Quality (Ash) INF 336 Week 3 Assignment Need Definition (Ash) INF 336 Week 4 DQ 1 Procuring Services (Ash) ...

  4. MGT 401 ASH Course Tutorial / Tutorialoutlet

    OpenAIRE

    kennith

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   MGT 401 Week 1 Individual Assignment Strategic Management Process Paper (Ash) MGT 401 Week 1 Class Activity Week 1 (Ash) MGT 401 Week 1 DQ 1 (Ash) MGT 401 Week 1 DQ 2 (Ash) MGT 401 Week 2 Learning Team Business Model Comparison Example (Ash) MGT 401 Week 2 DQ 1 (Ash) MGT 401 Week 2 DQ 2 (Ash) MGT 401 Week 2 Class Activity (Ash) MGT 401 Week 3 Individual Assignment Business Plan Evaluation (Ash) ...

  5. INF 410 ASH Course Tutorial / Tutorialoutlet

    OpenAIRE

    MADHURA

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com     INF 410 Week 1 DQ 1 Project Life Cycle (Ash) INF 410 Week 1 DQ 2 The Importance of Project Management (Ash) INF 410 Week 1 Quiz (Ash) INF 410 Week 2 DQ 1 Project Charter (Ash) INF 410 Week 2 DQ 2 Project Management Plan (Ash) INF 410 Week 2 Quiz (Ash) INF 410 Week 3 DQ 1 Risk Identification (Ash) INF 410 Week 3 DQ 2 Triple Constraint (Ash) INF 410 Week 3 Quiz (Ash) INF 410 Week 4 DQ...

  6. Pre-study - Straw ash in a nutrient loop; Foerstudie - Halmaska i ett kretslopp

    Energy Technology Data Exchange (ETDEWEB)

    Ottosson, Peter; Bjurstroem, Henrik; Johansson, Christina; Svensson, Sven-Erik; Mattsson, Jan Erik

    2009-03-15

    straw from soils with higher cadmium content. To avoid that a farm with a low cadmium concentration in the straw receives ash with a high content, one could combust area-wise and recycle area-wise, or choose not to fetch straw from farms with high cadmium contents in soils, or spread only bottom ash. However, if fly ash is not utilised, a large part of the potassium is lost. The conclusion is that recycling of straw ash to fields is feasible and development work should continue after this pre-study. The pre-study need to be developed in the following areas: Means to spread a small quantity of ash to fields, with as small a negative effect as possible. Machines for spreading straw ash have been studied in some Swedish investigations, and before proceeding further one should gather additional information, a.o. on foreign machinery for spreading straw ash Test lime spreading techniques, pipe model, for agglomerated ash (wet, cured, crushed and sieved straw ash) As ash is a fertiliser, a method to calculate doses should be developed. This implies a.o. an analysis of potassium and phosphorus available to plants The availability of cadmium to plants should be studied in order to determine in which phase of a crop rotation ash should be returned in order to minimize the risk that plants take up cadmium If one chooses to recycle only bottom ash, one should continue to investigate means to extract potassium from fly ash, as ca 50 % of the potassium content is in the fly ash

  7. Electrodialytic treatment of fly ash

    DEFF Research Database (Denmark)

    Jensen, Pernille Erland; Pedersen, Anne Juul; Kirkelund, Gunvor Marie;

    Heavy metals are removed from the fly ashes by an electrodialytic treatment with the aim of up-grading the ashes for reuse in stead of disposal in landfill.A great potential for upgrading of bio- and waste incineration ashes by electrodialytic treatment exists. In the future, the applicability of...... the treated products for reuse in construction or farming sectors should be explored further, as should the possibility of recycling of valuable, extracted elements in the metallurgical industry....

  8. Classification of pulverized coal ash

    International Nuclear Information System (INIS)

    The leachability of fifty different pulverized coal ashes from utilities in the Netherlands, Federal Republic of Germany and Belgium has been studied. Five different ashes were analyzed according to the complete standard leaching test and the results were published earlier. The examination of a wide variety of ashes under a wide range of pH and Liquid to Solid ratio (LS) conditions creates the possibility of identifying systematic trends in fly ash leaching behaviour and to identify the mechanisms controlling release. 16 figs., 2 tabs., 3 app., 25 refs

  9. Dielectric properties of fly ash

    Indian Academy of Sciences (India)

    S C Raghavendra; R L Raibagkar; A B Kulkarni

    2002-02-01

    This paper reports the dielectric properties of fly ash. The dielectric measurements were performed as a function of frequency and temperature. The sample of fly ash shows almost similar behaviour in the frequency and temperature range studied. The large value of dielectric constant in the typical frequency range is because of orientation polarization and tight binding force between the ions or atoms in the fly ash. The sample of fly ash is of great scientific and technological interest because of its high value of dielectric constant (104).

  10. WET SOLIDS FLOW ENHANCEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2001-03-25

    The yield locus, tensile strength and fracture mechanisms of wet granular materials were studied. The yield locus of a wet material was shifted to the left of that of the dry specimen by a constant value equal to the compressive isostatic stress due to pendular bridges. for materials with straight yield loci, the shift was computed from the uniaxial tensile strength, either measured in a tensile strength tester or calculated from the correlation, and the angle of internal friction of the material. The predicted shift in the yield loci due to different moisture contents compare well with the measured shift in the yield loci of glass beads, crushed limestone, super D catalyst and Leslie coal. Measurement of the void fraction during the shear testing was critical to obtain the correct tensile strength theoretically or experimentally.

  11. Experimental studies on pulp and paper mill sludge ash behavior in fluidized bed combustors

    Energy Technology Data Exchange (ETDEWEB)

    Latva-Somppi, J. [VTT Chemical Technology, Espoo (Finland). Process Technology

    1998-11-01

    Ash formation during the fluidized bed combustion (FBC) of pulp and paper mill sludges has been experimentally studied on an industrial and bench scale. The methods included aerosol measurements, chemical and crystalline composition analyses, thermogravimetry and electron microscopy. Fly ash mass and number size distributions and elemental enrichment in submicron particles and bottom ash were measured. Fly ash, bottom ash and ash deposits were characterized and their formation mechanisms are discussed. During combustion the fine paper-making additives in sludge, clay minerals and calcite, sintered fanning porous agglomerates. The fly ash mass mean size was 7.5 - 15 lam and the supermicron particles included 93.6 - 97.3 % of the fly ash. Condensation of the volatilized inorganic species formed spherical submicron particles in the fly ash. Their mass concentration was almost negligible when co-firing paper mill sludges and wood. This suggests that the fraction of the volatilized inorganic species in the paper mill sludges was low. Results from pulp mill sludge and bark co-firing were different. A clear mass mode below 0.3 pm, presenting 2.2 - 5.0 weight-% of the fly ash was detected. The condensed species included K, Na, S and Cl. Their mass fraction was higher in the pulp mill sludge than in the paper mill sludge. Evidently this resulted in increased volatilization and formation of condensed particles. The following trace elements were enriched in the submicron ash during pulp mill sludge and wood co-firing: As, Cd, Rb and Pb. The main part of the volatile species was, however, captured in the bulk ash. Presumably, this was due to the high surface area concentration in the bulk ash. Sludge moisture was observed to reduce the inorganic species volatilization. Probably steam vaporization from the wet sludge through the burning layer decreased combustion temperatures on char surface and less char was produced. Hence, the volatilization of ash forming species was

  12. Can ash clog soil pores?

    Science.gov (United States)

    Stoof, Cathelijne; Stoof, Cathelijne; Gevaert, Anouk; Gevaert, Anouk; Baver, Christine; Baver, Christine; Hassanpour, Bahareh; Hassanpour, Bahareh; Morales, Veronica; Morales, Veronica; Zhang, Wei; Zhang, Wei; Martin, Deborah; Martin, Deborah; Steenhuis, Tammo; Steenhuis, Tammo

    2015-04-01

    Wildfire can greatly increase a landscape's vulnerability to flooding and erosion events, and ash is thought to play a large role in controlling runoff and erosion processes after wildfire. Although ash can store rainfall and thereby reduce runoff and erosion for a limited period after wildfires, it has also been hypothesized to clog soil pores and reduce infiltration. Several researchers have attributed the commonly observed increase in runoff and erosion after fire to the potential pore-clogging effect of ash. Evidence is however incomplete, as to date, research has solely focused on identifying the presence of ash in the soil, with the actual flow processes associated with the infiltration and pore-clogging of ash remaining a major unknown. In several laboratory experiments, we tested the hypothesis that ash causes pore clogging to the point that infiltration is hampered and ponding occurs. We first visualized and quantified pore-scale infiltration of water and ash in sand of a range of textures and at various infiltration rates, using a digital bright field microscope capturing both photo and video. While these visualization experiments confirm field and lab observation of ash washing into soil pores, we did not observe any clogging of pores, and have not been able to create conditions for which this does occur. Additional electrochemical analysis and measurement of saturated hydraulic conductivity indicate that pore clogging by ash is not plausible. Electrochemical analysis showed that ash and sand are both negatively charged, showing that attachment of ash to sand and any resulting clogging is unlikely. Ash also had quite high saturated conductivity, and systems where ash was mixed in or lying on top of sand had similarly high hydraulic conductivity. Based on these various experiments, we cannot confirm the hypothesis that pore clogging by ash contributes to the frequently observed increase in post-fire runoff, at least for the medium to coarse sands

  13. Reducing carbon-in-ash

    Energy Technology Data Exchange (ETDEWEB)

    Nigel S. Dong [IEA Clean Coal Centre, London (United Kingdom)

    2010-05-15

    High levels of carbon-in-ash lead to reduced power plant efficiency and higher fuel costs, degrade the performance of electrostatic precipitators and increase emissions of particulates. Increased carbon levels in the fly ash can lead to problems with ash use in cement/concrete production. This report reviews current measures and technologies that can be used to prevent excessive carbon-in-ash in pulverised coal combustion (PCC) power plants. These include coal cleaning, coal fineness improvement, reduction of distribution imbalance of coal among burners, increasing coal-air mixing rates at both burner and OFA levels and optimising excess air ratios. A plasma-assisted combustion enhancement technology can help achieve better ignition and more stable flame for coals that are normally difficult to burn. Computer-based combustion optimisation using expert systems, neural network systems and coal combustion simulation is becoming an invaluable means to tackle the carbon-in-ash issue. This report also reviews the regulations in nine major coal-consuming countries, which stipulate the maximum unburnt carbon levels permitted for fly ash for use in concrete/cement production. The Loss on Ignition (LOI) parameter is used in all national standards, although it is considered inadequate and may exclude some usable fly ash from being utilised. Performance-based regulations are more appropriate and have been adopted by Canada and USA. The EU and Canada now permit the use of fly ash produced from co-combustion of coal and biomass. China and Russia allow very high LOI levels for certain fly ash but the other countries require similar LOI limits for fly ash for use in concrete. Finally, this report discusses measures and technologies for reduction of carbon-in-ash, including classification, froth flotation, triboelectrostatic separators, thermal processes and carbon surface modification. 146 refs., 19 figs., 15 tabs.

  14. Fly ash quality and utilization

    Energy Technology Data Exchange (ETDEWEB)

    Barta, L.E.; Lachner, L.; Wenzel, G.B. [Inst. for Energy, Budapest (Hungary); Beer, M.J. [Massachusetts Inst. of Technology, Cambridge, MA (United States)

    1995-12-01

    The quality of fly ash is of considerable importance to fly ash utilizers. The fly ash puzzolanic activity is one of the most important properties that determines the role of fly ash as a binding agent in the cementing process. The puzzolanic activity, however is a function of fly ash particle size and chemical composition. These parameters are closely related to the process of fly ash formation in pulverized coal fired furnaces. In turn, it is essential to understand the transformation of mineral matter during coal combustion. Due to the particle-to-particle variation of coal properties and the random coalescence of mineral particles, the properties of fly ash particles e.g. size, SiO{sub 2} content, viscosity can change considerably from particle to particle. These variations can be described by the use of the probability theory. Since the mean values of these randomly changing parameters are not sufficient to describe the behavior of individual fly ash particles during the formation of concrete, therefore it is necessary to investigate the distribution of these variables. Examples of these variations were examined by the Computer Controlled Scanning Electron Microscopy (CCSEM) for particle size and chemical composition for Texas lignite and Eagel Butte mineral matter and fly ash. The effect of combustion on the variations of these properties for both the fly ash and mineral matter were studied by using a laminar flow reactor. It is shown in our paper, that there are significant variations (about 40-50% around the mean values) of the above-listed properties for both coal samples. By comparing the particle size and chemical composition distributions of the mineral matter and fly ash, it was possible to conclude that for the Texas lignite mineral matter, the combustion did not effect significantly the distribution of these properties, however, for the Eagel Butte coal the combustion had a major impact on these mineral matter parameters.

  15. Wetting phenomena in electrolyte solutions

    OpenAIRE

    Ibagon, Ingrid

    2014-01-01

    The present study analyzes wetting phenomena in electrolyte solutions. They are investigated by means of classical density functional theory. First, the wetting of a charged substrate by an electrolyte solution is studied with emphasis on the influence of the substrate charge density and of the ionic strength on the wetting transition temperature and on the order of the wetting transition. The corresponding models consist of solvent particles, anions, and cations. Two mean field approaches ar...

  16. Measurement of natural activity in peat ashes

    International Nuclear Information System (INIS)

    High proportions of radioactive materials in peat ashes may involve radiation hazards during handling and deposition of these waste materials. Measurements have been performed to determine the content of radioactive materials in ashes from peat burning. The activities in fly ash and ''solid'' ash in seven peat-fired power plants in Sweden are presented. The methods of analysing and measuring peat ashes for activity from different radionuclides are described. The activity levels in ash samples are given

  17. BUS 611 Ash course tutorial / uophelp

    OpenAIRE

    uophelp

    2015-01-01

    For more course tutorials visit www.uophelp.com   BUS 611 Week 1 Assignment Article Review (Ash Course) BUS 611 Week 2 Assignment Project Risk (Ash Course) BUS 611 Week 3 Assignment WBS (Ash Course) BUS 611 Week 4 Assignment Integrated Project Management Tools (Ash Course) BUS 611 Week 5 Assignment Monthly Status Reports (Ash Course) BUS 611 Week 6 Final Research Paper (Ash Course)  

  18. ECO 316(ASH) course tutorial/tutorialoutlet

    OpenAIRE

    naresh 1

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   ECO 316 Week 1 DQ 1 Should You Invest Short Term (Ash) ECO 316 Week 1 DQ 2 Treasury Inflation Protection Bonds (Ash) ECO 316 Week 1 Quiz (Chapter 1-6) (Ash) ECO 316 Week 2 DQ 1 New Product, Will I Be Rich (Ash) ECO 316 Week 2 DQ 2 Mutual Fund Regulation (Ash) ECO 316 Week 2 Quiz (Chapter 7-12) (Ash) ECO 316 Week 3 DQ 1 Exchange Rate Risk (Ash) ECO 316 Week 3 DQ 2 Should I Expect a Bail Out (Ash) ...

  19. CRJ 303 ASH course tutorial/tutorialoutlet

    OpenAIRE

    naresh 1

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   Product Description CRJ 303 Week 1 DQ 1 Goals of Sentencing (Ash) CRJ 303 Week 1 DQ 2 Sentencing Techniques (Ash) CRJ 303 Week 2 DQ 1 Punishment (Ash) CRJ 303 Week 2 DQ 2 Privatizing Prisons (Ash) CRJ 303 Week 2 Assignment Jails vs. Prisons (Ash) CRJ 303 Wee 3 DQ 1 Probation and Parole (Ash) CRJ 303 Week 3 DQ 2 Civil Commitments (Ash) CRJ 303 Week 3 Assignment Juvenile Detainees (Ash) CRJ 303...

  20. PSY 496 ASH Tutorial Course / Uoptutorial

    OpenAIRE

    John Allen

    2015-01-01

    PSY 496 Week 1 Assignment Foundations for the Final Paper (Ash) PSY 496 Week 2 Assignment Finalized Resources and Revisions for the Final Paper (Ash) PSY 496 Week 1 DQ 1 Approaches to Research (Ash) PSY 496 Week 1 DQ 2 Measuring Change (Ash) PSY 496 Week 2 DQ 1 Protecting Participants from Harm (Ash) PSY 496 Week 2 DQ 2 Areas of Competence (Ash) PSY 496 Week 2 Journal Ethics in Research and Practice (Ash) PSY 496 Week 3 Assignment Final Paper Draft (Ash) PSY 49...

  1. MGT 415 ASH Course Tutorial / Tutorialoutlet

    OpenAIRE

    kennith archi

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   MGT 415 Week 1 DQ 1 Organizational Design (Ash) MGT 415 Week 1 DQ 2 The Research Project (Ash) MGT 415 Week 2 DQ 1 Group Development Process (Ash) MGT 415 Week 2 DQ 2 Influence of Informal Groups (Ash)  MGT 415 Week 3 DQ 1 Group Cohesion and Productivity (Ash) MGT 415 Week 3 DQ 2 Norms and Conformity (Ash) MGT 415 Week 3 Assignment Best Workplace (Ash) MGT 415 Week 4 DQ 1 Group Decisions (Ash) ...

  2. HIS 103 ASH course tutorial/tutorialoutlet

    OpenAIRE

    NARESH 34

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   HIS 103 Week 1 DQ 1 (Transition to Agriculture) (Ash) HIS 103 Week 1 DQ 2 (Early Complex Societies) (Ash) HIS 103 Week 1 Quiz (Ash) HIS 103 Week 1 Assignment (Ash) HIS 103 Week 2 Assignment Greco Roman Influence Paper (Ash) HIS 103 Week 2 DQ 1 Chinese Social and Political Order Systems (Ash) HIS 103 Week 2 DQ 2 Caste System (Ash) HIS 103 Week 2 Quiz (Ash) HIS 103 Week 3 Assignment Black Death Dra...

  3. MAT 222 ASH Course Tutorial / Tutorialoutlet

    OpenAIRE

    mirat

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   MAT 222 Week 1 Solving Proportions (Ash) MAT 222 Week 1 DQ 1 Can't Cancel Terms (Ash) MAT 222 Week 2 DQ 1 One-Variable Compound Inequalities (Ash) MAT 222 Week 2 Two-Variable Inequalities (Ash) MAT 222 Week 3 DQ 1 Simplifying Radicals (Ash) MAT 222 Week 3 Real World Radical Formulas (Ash) MAT 222 Week 4 DQ 1 Solving Quadratic Equations (Ash) MAT 222 Week 4 Real World Quadratic Functions (Ash) ...

  4. BUS 642 Ash course tutorial / uophelp

    OpenAIRE

    uophelp

    2015-01-01

    www.uophelp.com     BUS 642 Week 1 DQ 1 Scientific Thinking (Ash Course) BUS 642 Week 1 DQ 2 Making Research Decisions (Ash Course) BUS 642 Week 1 Exercises (Ash Course) BUS 642 Week 2 DQ 1 Ethics in Business Research (Ash Course) BUS 642 Week 2 DQ 2 Design of Research (Ash Course) BUS 642 Week 2 Exercises (Ash Course) BUS 642 Week 3 DQ 1 Measurement Scales (Ash Course) BUS 642 Week 3 DQ 2 Clarifying the Research Questions (Ash Course) BUS...

  5. Leaching from biomass combustion ash

    DEFF Research Database (Denmark)

    Maresca, Alberto; Astrup, Thomas Fruergaard

    2014-01-01

    water. The content of the selected heavy metals (i.e. Cr, Ni, Pb and Cd) complied with the Danish Statutory Order on the use of bio-ash for agricultural purposes; however, critical releases of Cr were detected in the leachate extracts, especially in the fly ash. High alkaline pHs were measured in all...

  6. Volcanic ash - Terrestrial versus extraterrestrial

    Science.gov (United States)

    Okeefe, J. A.

    1976-01-01

    A principal difference between terrestrial and extraterrestrial lavas may consist in the greater ability of terrestrial lavas to form thin films (like those of soap bubbles) and hence foams. It would follow that, in place of the pumice and spiny shards found in terrestrial volcanic ash, an extraterrestrial ash should contain minute spherules. This hypothesis may help to explain lunar microspherules.

  7. Natural radioactivity in volcanic ash from Mt. Pinatubo eruption

    International Nuclear Information System (INIS)

    Last June 15, 1991, a major pyroclastic eruption occurred from Mt. Pinatubo volcano located in Zambales, Central Luzon. The radiological impact of this eruption was assessed based on the concentrations of the principal naturally occurring radionuclides observed in volcanic ash. The volcanic ash samples were collected from locations which are within 50-km radius of Mt. Pinatubo at various times after the eruption. The mean activity concentrations in Bq/kg wet weight of the natural radionuclides in volcanic ash were as follows: 12.6 for 238U, 14.0 for 232Th and 330 for 40K. These values are significantly higher than the mean activity concentrations of these radionuclides observed in topsoil in the same provinces before the eruption. This suggests that with the deposition of large quantities of volcanic ash and lahar in Central Luzon and concomitant topographic changes, the distribution and quantities of radionuclides which gave rise to terrestrial radiation may have also changed. Outdoor radon concentrations measured three days and later after the eruption were within normal background values. (auth.). 4 refs.; 5 tabs.; 1 fig

  8. Using fly ash for construction

    Energy Technology Data Exchange (ETDEWEB)

    Valenti, M.

    1995-05-01

    Each year electrical utilities generate 80 million tons of fly ash, primarily from coal combustion. Typically, utilities dispose of fly ash by hauling it to landfills, but that is changing because of the increasing cost of landfilling, as well as environmental regulations. Now, the Electric Power Research Institute (EPRI), in Palo Alto, Calif., its member utilities, and manufacturers of building materials are finding ways of turning this energy byproduct into the building blocks of roads and structures by converting fly ash into construction materials. Some of these materials include concrete and autoclaved cellular concrete (ACC, also known as aerated concrete), flowable fill, and light-weight aggregate. EPRI is also exploring uses for fly ash other than in construction materials. One of the more high-end uses for the material is in metal matrix composites. In this application, fly ash is mixed with softer metals, such as aluminum and magnesium, to strengthen them, while retaining their lighter weight.

  9. Effects of coal fly ash-amended composts on the yield and elemental uptake by plants

    International Nuclear Information System (INIS)

    The objective of this study was to determine the feasibility of coal fly ash-amended composts for use as an alternate manure for agricultural crops. Home-made organic composts was mixed in various proportions with fine fly ash collected from Savannah River Site, and allowed to decompose for two weeks while the mixture was kept wet. Water extracts from the amended composts were analyzed for selected major and trace elements. These amended composts were mixed with sifted sandy loam soil in a predetermined optimum ratio of 1:3 and used to grow corn and sorghum plants. It was shown that fly ash additions to home-made compost facilitated efficient plant utilization of nutrients when 20-40% fly ash in compost was applied to the soil. The maximum dry shoot yields correlated with the higher concentrations of K, Ca and N and lower concentrations of B in the amended compost treatment

  10. Effectiveness of treatments to establish trees on minelands during drought and wet years

    International Nuclear Information System (INIS)

    In two studies, green ash (Fraxinus pennsylvanica) and white pine (Pinus strobus) were planted on three minesoils (graded topsoil, ripped topsoil, and gray cast overburden). Mixtures of grasses and/or legumes were seeded at different times in relation to tree planting. In the first study, tree planting was followed by several weeks of drought; in the second study, precipitation was above average for the first two growing seasons following planting. In the drought year, survival of green ash was influenced by minesoil type, herbaceous mixture, and time of seeding in relation to tree planting. Among minesoils, ash survival on ripped topsoil was 28% above that on graded topsoil in one seeding treatment, but mean survival was highest (87%) on cast overburden. Seeding grasses the fall before planting resulted in poor ash survival (40% to 47%) compared with seeding at time of planting (82% to 85%). Ash survived well (81% to 94%) on legume-seeded plots owing, in part, to slow early development of legumes the first season. When tree planting was followed by two wet seasons, survival at 4 and 5 yr ranged from very good to excellent, with much smaller differences between treatments. Total height of ash trees on cast overburden averaged 31% less than that of trees on topsoil. Mean height of ash on legume-seeded subplots was 75 cm, compared with 58 cm on grass subplots, although herbaceous biomass was greater on legume subplots. The three minesoils proved unsuitable for white pine

  11. Mercury in coal ash and its fate in the Indian subcontinent: A synoptic review

    International Nuclear Information System (INIS)

    In the Indian subcontinent power generation is mainly dependent upon the thermal power units and coal is burnt as a fuel for the production of heat and electricity. In India, bituminous and sub-bituminous coals are used which contain over 40% of ash. At present, 80-90 million tons of fly ashes are generated from 85 existing coal based thermal power plants. Coal contains trace metals of which mercury is most toxic for humans and aquatic fauna. The problem of mercury in the society is not new, but in recent years the Indian subcontinent has gained the reputation of being 'a dumping ground for mercury'. This study focuses on mercury in fly ash and its releases to the atmosphere and soils cross the country. The utilisation of coal ash in India is also addressed although it is still in its nascent stage. About 10% of produced fly ashes are used in India whereas in Western countries its use is typically over 70%. Regulations from India's Ministry of Environment and Forestry should increase coal fly ash utilisation, although this would require that cost-effective new technology is put to use. As to the release of Hg from ashes disposed of in the environment, the scarce literature suggests that this is negligible or zero, and less problematic than wet or dry deposition of Hg from flue gases. (author)

  12. Studies on Carbon-Fly Ash Composites with Chopped PANOX Fibers

    Directory of Open Access Journals (Sweden)

    Rakesh V. Patel

    2013-01-01

    Full Text Available Chemical analysis and morphological studies of fly ash reveals the complex chemical constituents present as spherical particles with diameter of less than 25 μm. The constituents of fly ash are silica, alumina, iron oxide, titanium dioxide, calcium and magnesium oxide, and other trace elements. The use of thermosetting as well thermoplastic polymer matrix has been made by several workers to develop polymer matrix fly ash particulate composites by using the hard and abrasive properties of fly ash and lightweight of polymers. Such composites have poor mechanical strength, fracture toughness, and thermal stability. To overcome these shortcomings, in carbonaceous matrix, the carbon fibers were added as additional reinforcement along with the fly ash. The composites were developed with two different methods known as Dry method and Wet method. The processing parameters such as temperature and pressure were optimized in establishing the carbon matrix. Physical, thermal, and mechanical characteristics were studied. The microstructures of composites show good compatibility between fly ash and fibers with the carbon matrix. These composites have higher strength, thermal stability, and toughness as compared to polymer matrix fly ash particulate composites.

  13. Increased sensitivity in thick-target particle induced X-ray emission analyses using dry ashing for preconcentration

    International Nuclear Information System (INIS)

    The sensitivity in thick-target particle induced X-ray emission (PIXE) analyses of biological materials can be enhanced by dry ashing. The gain depends mainly on the mass reduction factor and the composition of the residual ash. The enhancement factor was 7 for the certified reference material Pine Needles and the limits of detection (LODs) were below 0.2 μg/g for Zn, Cu, Rb and Sr. When ashing biological materials with low ash contents such as wood of pine or spruce (0.3% of dry weight) and honey (0.1% of wet weight) the gain was far greater. The LODs for these materials were 30 ng/g for wood and below 10 ng/g for honey. In addition, the ashed samples were more homogenous and more resistant to changes during the irradiation than the original biological samples. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  14. Wet steam wetness measurement in a 10 MW steam turbine

    Directory of Open Access Journals (Sweden)

    Kolovratník Michal

    2014-03-01

    Full Text Available The aim of this paper is to introduce a new design of the extinction probes developed for wet steam wetness measurement in steam turbines. This new generation of small sized extinction probes was developed at CTU in Prague. A data processing technique is presented together with yielded examples of the wetness distribution along the last blade of a 10MW steam turbine. The experimental measurement was done in cooperation with Doosan Škoda Power s.r.o.

  15. 49 CFR 230.69 - Ash pans.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Ash pans. 230.69 Section 230.69 Transportation... TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and Tenders Ash Pans § 230.69 Ash pans. Ash pans shall be securely supported from mud-rings or frames with no part less than...

  16. PREFACE: Wetting: introductory note

    Science.gov (United States)

    Herminghaus, S.

    2005-03-01

    The discovery of wetting as a topic of physical science dates back two hundred years, to one of the many achievements of the eminent British scholar Thomas Young. He suggested a simple equation relating the contact angle between a liquid surface and a solid substrate to the interfacial tensions involved [1], γlg cos θ = γsg - γsl (1) In modern terms, γ denotes the excess free energy per unit area of the interface indicated by its indices, with l, g and s corresponding to the liquid, gas and solid, respectively [2]. After that, wetting seems to have been largely ignored by physicists for a long time. The discovery by Gabriel Lippmann that θ may be tuned over a wide range by electrochemical means [3], and some important papers about modifications of equation~(1) due to substrate inhomogeneities [4,5] are among the rare exceptions. This changed completely during the seventies, when condensed matter physics had become enthusiastic about critical phenomena, and was vividly inspired by the development of the renormalization group by Kenneth Wilson [6]. This had solved the long standing problem of how to treat fluctuations, and to understand the universal values of bulk critical exponents. By inspection of the critical exponents of the quantities involved in equation~(1), John W Cahn discovered what he called critical point wetting: for any liquid, there should be a well-defined transition to complete wetting (i.e., θ = 0) as the critical point of the liquid is approached along the coexistence curve [7]. His paper inspired an enormous amount of further work, and may be legitimately viewed as the entrance of wetting into the realm of modern physics. Most of the publications directly following Cahn's work were theoretical papers which elaborated on wetting in relation to critical phenomena. A vast amount of interesting, and in part quite unexpected, ramifications were discovered, such as the breakdown of universality in thin film systems [8]. Simultaneously, a number

  17. BUS 620 Ash course tutorial / uophelp

    OpenAIRE

    uophelp

    2015-01-01

    For more course tutorials visit www.uophelp.com   BUS 620 Week 1 DQ 1 What is Marketing (Ash Course) BUS 620 Week 1 DQ 2 Marketing Strategies (Ash Course) BUS 620 Week 1 The Future of the New York Times (Ash Course) BUS 620 Week 2 DQ 1 Buyer Behavior (Ash Course) BUS 620 Week 2 DQ 2 Customer Needs (Ash Course) BUS 620 Week 2 Industry Forecasting (Ash Course) BUS 620 Week 3 DQ 1 Braining Nordstrom (Ash Course) BUS 620 Week 3 DQ 2 Marketing Segmentat...

  18. GEN 499 ASH course tutorial/tutorialoutlet

    OpenAIRE

    NARESH 34

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com       GEN 499 Week 1 DQ 1 Final Research Paper Topic and Plan (Ash) GEN 499 Week 1 DQ 2 Social Media (Ash) GEN 499 Week 2 DQ 1 Professional Resume and Cover Letter (Ash) GEN 499 Week 2 Assignment Critiquing Internet Sources (Ash) GEN 499 Week 3 DQ 1 Social Capital (Ash) GEN 499 Week 3 DQ 2 Federal Policy (Ash) GEN 499 Week 3 Assignment Annotated Bibliography (Ash) GEN 499 Week 4 DQ 1...

  19. BUS 372 ASH Material - bus372dotcom

    OpenAIRE

    lucky108

    2015-01-01

    For more course tutorials visit www.bus372.com       BUS 372 Week 1 DQ 1 The Role of Unionization (Ash Course) BUS 372 Week 1 DQ 2 Meeting Member Needs (Ash Course) BUS 372 Week 2 DQ 1 Profit Interest and Employee Interest (Ash Course) BUS 372 Week 2 DQ 2 Union Requirements (Ash Course) BUS 372 Week 2 Assignment Changing Landscape of Unions (Ash Course) BUS 372 Week 2 Quiz (Ash Course) BUS 372 Week 3 DQ 1 Strikes (Ash Course) BUS ...

  20. EDU 623 ASH COURSE Tutorial/UOPHELP

    OpenAIRE

    dgfvbhn

    2015-01-01

    For more course tutorials visit www.uophelp.com   EDU 623 Week 1 No Child Left Behind (Ash Course) EDU 623 Week 1 DQ 1 Skills Needed for Master of Education (Ash Course) EDU 623 Week 1 DQ 2 Effective Teachers (Ash Course) EDU 623 Week 2 Writing and Researching Skills Self-Assessment (Ash Course) EDU 623 Week 2 DQ 1 Evaluating Research (Ash Course) EDU 623 Week 2 DQ 2 Diversity in Schools (Ash Course) EDU 623 Week 3 Lesson Plan Critique (Ash Course) ...

  1. HCA 375 (ASH) course tutorial/tutorialoutlet

    OpenAIRE

    NARESH 34

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com     HCA 375 Week 1 DQ 1 Management versus Leadership (Ash) HCA 375 Week 1 DQ 2 Implementation and Barriers (Ash) HCA 375 Week 2 DQ 1 Measurement (Ash) HCA 375 Week 2 DQ 2 Quality and Outcomes (Ash) HCA 375 Week 2 Assignment Customer Satisfaction and Quality Care (Ash) HCA 375 Week 3 DQ 1 Teamwork in Health Care (Ash) HCA 375 Week 3 DQ 2 The Impact of Nursing (Ash) HCA 375 Week 3 Ass...

  2. HCA 430(ASH) course tutorial/tutorialoutlet

    OpenAIRE

    NARESH 34

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   HCA 430 Week 1 DQ 1 Perspective (Ash) HCA 430 Week 1 DQ 2 Trends in Vulnerable Populations (Ash) HCA 430 Week 2 DQ 1 Vulnerable Populations (Ash) HCA 430 Week 2 DQ 2 Resource Availability (Ash) HCA 430 Week 2 DQ 3 Race, Ethnicity, and Healthcare (Ash) HCA 430 Week 2 Assignment Critical Thinking Paper (Ash) HCA 430 Week 3 DQ 1 Continuum of Care (Ash) HCA 430 Week 3 DQ 2 Paying for Healthcar...

  3. ENG 328 ASH course tutorial/tutorialoutlet

    OpenAIRE

    NARESH 34

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com     ENG 328 Week 1 DQ 1 What is Technical Writing (Ash) ENG 328 Week 1 DQ 2 Target Audience (Ash) ENG 328 Week 2 DQ 1 Collaborative Writing Process (Ash) ENG 328 Week 2 DQ 2 Design and Graphics (Ash) ENG 328 Week 3 DQ 1 Web Design and Readability (Ash) ENG 328 Week 3 DQ 2 Online Technical Documents (Ash) ENG 328 Week 4 DQ 1 Writing Instructions (Ash) ENG 328 Week 4 DQ 2 Writing Proposa...

  4. EDU 623 ASH COURSES TUTORIAL/UOPHELP

    OpenAIRE

    ROOSER12

    2015-01-01

    For more course tutorials visit www.uophelp.com   EDU 623 Week 1 No Child Left Behind (Ash Course) EDU 623 Week 1 DQ 1 Skills Needed for Master of Education (Ash Course) EDU 623 Week 1 DQ 2 Effective Teachers (Ash Course) EDU 623 Week 2 Writing and Researching Skills Self-Assessment (Ash Course) EDU 623 Week 2 DQ 1 Evaluating Research (Ash Course) EDU 623 Week 2 DQ 2 Diversity in Schools (Ash Course) EDU 623 Week 3 Lesson Plan Critique (Ash Course) ...

  5. Current Methods to Detoxify Fly Ash from Waste Incineration

    Energy Technology Data Exchange (ETDEWEB)

    Hallgren, Christine; Stroemberg, Birgitta [TPS Termiska Processer AB, Nykoeping (Sweden)

    2004-07-01

    Fly ash from waste incineration contains large amounts of heavy metals and dioxins, which will cause a significant disposal problem within the coming years. The amount of fly ash produced in Sweden is currently approximately 60,000 tons/y. New technological options for the decontamination and/or inertization of incinerator fly ash are being developed with the objective of rendering a product that can be reused or, at least, be deposited at standard landfill sites with no risk. Many of these technologies have been tested at industrial scale or in pilot projects. The proposed alternatives include: Thermal treatments; Immobilization/stabilization by cement based techniques; Wet chemical treatments (extractions, immobilizations); Microbiological treatments. Of these, thermal treatments are the most promising solution. Depending on the temperature thermal treatments are classified in two main types: 1) low temperature (below 600 deg C) thermal treatments and 2) high temperature (above 1200 deg C) thermal treatments (vitrification). Most dioxins can be successfully destroyed at temperatures up to 400 deg C under oxygen deficient conditions and at temperatures up to 600 deg C under oxidising conditions. However most heavy metals remain in the fly ash after low temperature treatment. At a temperature of 900 deg C most heavy metals can also be removed in a 10% HCl atmosphere by forming volatile metal chlorides (CT-Fluapur process). During vitrification processes the fly ash melts and forms an inert glassy slag. The product does not leach any significant amount of heavy metals and is free from dioxin. The volume of the fly ash is significantly reduced. The product can be land filled at low costs or used as construction material. The properties of the product depend on the cooling process and on additives such as sand, limestone or waste glass. A series of vitrification methods at industrial size or in pilot scale using different furnaces are studied. Among these, plasma

  6. NTPC`s experiences in ash utilization

    Energy Technology Data Exchange (ETDEWEB)

    Trehan, A.; Krishnamurthy, R.; Kumar, A. [National Thermal Power Corporation Ltd., New Delhi (India)

    1997-12-31

    India is a major user of coal, and will remain so into the twenty first century. Ash disposal is a considerable problem, and NTPC has devised many methods of using ash, rather than dumping it. Such uses include the raising of ash dykes using coal ash rather than earth; structural fill; reclaiming low lying land; road construction; building materials; in the cement industry; in the asbestos industry; in agriculture; and backfilling in mines. Present and future use of ash is described. 1 tab.

  7. AshMeadowsNaucorid_CH

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify the areas where final critical habitat for the Ash Meadows Naucorid (Ambrysus amargosus) occur. "Nevada, Nye County. Point of Rocks Springs and...

  8. Conditioning processes for incinerator ashes

    International Nuclear Information System (INIS)

    Three conditioning processes for alpha-bearing solid waste incineration ashes were investigated and compared according to technical and economic criteria: isostatic pressing, cold-crucible direct-induction melting and cement-resin matrix embedding

  9. Fly ash. Quality recycling material

    Energy Technology Data Exchange (ETDEWEB)

    Blomster, D.; Leisio, C.

    1996-11-01

    Imatran Voima`s coal-fired power plants not only generate power and heat but also produce fly ash which is suitable raw material for recycling. This material for recycling is produced in the flue gas cleaning process. It is economical and, thanks to close quality control, is suitable for use as a raw material in the building materials industry, in asphalt production, and in earthworks. Structures made from fly ash are also safe from an environmental point of view. (orig.)

  10. Converting SDAP into gypsum in a wet limestone scrubber

    Energy Technology Data Exchange (ETDEWEB)

    Fogh, F. [Faelleskemikerne, Elsamprojekt A/S, Fredericia (Denmark)

    1996-12-01

    The ELSAM power pool has an installed electrical capacity of approx. 5 GW{sub e}, mainly firing import coal. The major base load units are equipped with desulphurization units and three different desulphurization technologies are used: the wet limestone gypsum process, the spray dry absorption process and a sulphuric acid process. Gypsum and sulphuric acid are commercialized, whereas it has been difficult to utilize the spray dry absorption product (SDAP). The main constituents of SDAP are calcium sulphide, calcium chloride, hydrated lime and impurities mainly originating from fly ash. Sulphide can be oxidized into sulphate in acidic solution - the reaction is utilized in the wet limestone gypsum process - and the possibility of using any spare capacity in the wet limestone gypsum units to oxidize the sulphide content of SDAP into sulphate and produce usable gypsum has been investigated in the laboratory and in a 400 MW{sub e} equivalent wet limestone unit. The limestone inhibition effect of the addition of SDAP is currently being studied in the laboratory in order to determine the effect of different SDAP types (plant/coal sources) on limestone reactivity before further long-term full-scale tests are performed and permanent use of the process planned. (EG)

  11. Coal ash utilisation in India

    International Nuclear Information System (INIS)

    Coal based thermal power stations have been the major source of power generation in our country in the past and would continue for decades to come. In India, thermal generation which contributes about 72% of the overall power generation of 2,45,000 MU (1989-90) is the main source of power and mainly based on coal firing. Total ash generation in India presently is to the tune of 38 million tonnes per annum. India is fourth in the world as far as coal ash generation is concerned. USSR is first, (100 million tonnes), then come USA (45 million tonnes) and China (41 million tonnes). The basic problem of thermal power station fired with high ash content coal is the generation of huge quantity of coal ash which would pose serious environmental and other related problems. The present paper analyses the extensive scope of utilisation of coal ash and enlightens the strategies to be adopted to overcome the related problems for proper utilisation of coal ash. (author). 9 tabs

  12. Wetting front instability in an initially wet unsaturated fracture

    International Nuclear Information System (INIS)

    Experimental results exploring gravity-driven wetting front instability in a pre-wetted, rough-walled analog fracture are presented. Initial conditions considered include a uniform moisture field wetted to field capacity of the analog fracture and the structured moisture field created by unstable infiltration into an initially dry fracture. As in previous studies performed under dry initial conditions, instability was found to result both at the cessation of stable infiltration and at flux lower than the fracture capacity under gravitational driving force. Individual fingers were faster, narrower, longer, and more numerous than observed under dry initial conditions. Wetting fronts were found to follow existing wetted structure, providing a mechanism for rapid recharge and transport

  13. Characterization of ashes from biofuels

    Energy Technology Data Exchange (ETDEWEB)

    Frandsen, F.J.; Hansen, L.A. [Technical Univ. of Denmark. Dept. of Chemical Engineering (Denmark); Soerensen, H.S. [Geological Survey of Denmark and Greenland (Denmark); Hjuler, K. [dk-TEKNIK. Energy and Environment (Denmark)

    1998-02-01

    One motivation for initiating the present project was that the international standard method of estimating the deposit propensity of solid fuels, of which a number of variants exist (e.g. ISO, ASTM, SD, DIN), has shown to be unsuitable for biomass ashes. This goal was addressed by the development of two new methods for the detection of ash fusibility behaviour based on Simultaneous Thermal Analysis (STA) and High Temperature Light Microscopy (HTLM), respectively. The methods were developed specifically for ashes from biofuels, but are suitable for coal ashes as well. They have been tested using simple salt mixtures, geological standards and samples from straw CHP and coal-straw PF combustion plants. All samples were run in a nitrogen atmosphere at a heating rate of 10 deg. C/min. In comparison with the standard method, the new methods are objective and have superior repeatability and sensitivity. Furthermore, the two methods enable the melting behavior to be characterized by a continuous measurement of melt fraction versus temperature. Due to this two-dimensional resolution of the results, the STA and HTLM methods provide more information than the standard method. The study of bottom ash and fly ash as well as deposit samples from straw test firings at the Haslev and Slagelse Combined Heat and Power plants resulted in a better understanding of mineral behaviour during straw grate firing. In these tests a number of straws were fired which had been carefully selected for having different qualities with respect to sort and potassium and chlorine contents. By studying bottom ashes from Slagelse it was found that the melting behaviour correlated with the deposition rate on a probe situated at the outlet part of the combustion zone. (EG)

  14. Mercury in coals and fly ashes from Republika and Bobov dol thermoelectric power plants

    Science.gov (United States)

    Kostova, I.; Vassileva, C.; Hower, J.; Mastalerz, Maria; Vassilev, S.; Nikolova, N.

    2011-01-01

    Feed coal and y ash samples were collected at Republika and Bobov Dol thermoelectric power plants (TPPs). The y ashes (FAs) were collected fromthree rows of the hot-side electrostatic precipitators (ESPs) array. Each sam- ple was wet-screened at 100, 200, 325 and 500 mesh. The coals and y ashes were characterized with regard to their petrological and chemical composition (including mercury content) and to their surface area properties. The calculated enrichment factor (EF) shows that the Hg concentrations in the bulk coal samples from Republika and Bobov Dol TPPs are 2.19 and 1.41, respectively. In some coal size fractions the EF can be up to 4 times higher than the Clarke value. The calculated EF for fly ashes shows that the Hg concentrations in the bulk samples studied are lower (between 0.03 and 0.32) than the Clarke value. The most enriched in Hg are the fly ashes from the 3rd ESP row of Republika TPP. The Hg distribution in bulk FAs taken from dierent rows of the electrostatic precipitators of both TPPs studied shows well established tendency of gradual increase in the Hg content from the 1st to the 2nd and 3rd ESP rows. The correlation between Hg content and surface area, mesopore and micropore volume of y ashes was also done in the present investigation.

  15. Encapsulation of mixed radioactive and hazardous waste contaminated incinerator ash in modified sulfur cement

    International Nuclear Information System (INIS)

    Some of the process waste streams incinerated at various Department of Energy (DOE) facilities contain traces of both low-level radioactive (LLW) and hazardous constituents, thus yielding ash residues that are classified as mixed waste. Work is currently being performed at Brookhaven National Laboratory (BNL) to develop new and innovative materials for encapsulation of DOE mixed wastes including incinerator ash. One such material under investigation is modified sulfur cement, a thermoplastic developed by the US Bureau of Mines. Monolithic waste forms containing as much as 55 wt % incinerator fly ash from Idaho national Engineering Laboratory (INEL) have been formulated with modified sulfur cement, whereas maximum waste loading for this waste in hydraulic cement is 16 wt %. Compressive strength of these waste forms exceeded 27.6 MPa. Wet chemical and solid phase waste characterization analyses performed on this fly ash revealed high concentrations of soluble metal salts including Pb and Cd, identified by the Environmental Protection Agency (EPA) as toxic metals. Leach testing of the ash according to the EPA Toxicity Characteristic Leaching Procedure (TCLP) resulted in concentrations of Pb and Cd above allowable limits. Encapsulation of INEL fly ash in modified sulfur cement with a small quantity of sodium sulfide added to enhance retention of soluble metal salts reduced TCLP leachate concentrations of Pb and Cd well below EPA concentration criteria for delisting as a toxic hazardous waste. 12 refs., 4 figs., 2 tabs

  16. Main characteristics of the radioactive enrichment in ashes produced in coal-fired power stations

    International Nuclear Information System (INIS)

    Under contract with the Spain's 'Nuclear Safety Council', a study is being conducted of the nation's largest nominal output coal-fired power stations. Its purpose is to assess the radiological impact on workers and local populations due to this source of NORM activity. One of the aspects of particular interest is the study of the radioactive enrichment in the combustion wastes relative to the different coals used as fuel (usually local bituminous coal or lignite, or imported coal). These wastes consist of fly ash (mostly fine particles collected in electrostatic precipitators), and bottom ash (larger in size, and collected wet or dry in hoppers below the boilers). In general terms, the enrichment factors measured were between 2 and 18 for the radionuclides 40K, 226Ra, 232Th, and 210Po. The magnitude of this enrichment factor depended mainly on the ash content of each coal, and hence on the type of coal used as fuel and the specific operation cycle in the different power stations. For the radionuclides 40K, 226Ra, and 232Th, the enrichment was relatively similar in value in the fly and bottom ashes produced by the different types of coal used in the power stations studied. For 210Po, however, as was expected, the enrichment was much greater in the fly ash than in the bottom ash for each coal analyzed. (author)

  17. EDU 623 ASH course tutorial/tutorialoutlet

    OpenAIRE

    NARESH 34

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com     EDU 623 Week 1 No Child Left Behind (Ash Course) EDU 623 Week 1 DQ 1 Skills Needed for Master of Education (Ash Course) EDU 623 Week 1 DQ 2 Effective Teachers (Ash Course) EDU 623 Week 2 Writing and Researching Skills Self-Assessment (Ash Course) EDU 623 Week 2 DQ 1 Evaluating Research (Ash Course) EDU 623 Week 2 DQ 2 Diversity in Schools (Ash Course) EDU 623 Week 3 Lesson Plan Critiqu...

  18. HCA 421(ASH) course tutorial/tutorialoutlet

    OpenAIRE

    NARESH 34

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   HCA 421 Week 1 DQ 1 (Basic Strategy) (Ash) HCA 421 Week 1 DQ 2 (Internal Audit of Strategic Assets) (Ash) HCA 421 Week 2 Assignment Competition in Healthcare (Ash) HCA 421 Week 2 DQ 1 (Strategic External Assessment Industry and Competition) (Ash) HCA 421 Week 2 DQ 2 (Market Segments) (Ash) HCA 421 Week 3 Assignment The Future Direction of Health Care (Five challenges) (Ash) HCA 421 Week 3 DQ 1 (Pr...

  19. HCA 415(ASH) course tutorial/tutorialoutlet

    OpenAIRE

    NARESH 34

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   HCA 415 Week 1 DQ 1 Historical Contributions of Public Health (Ash) HCA 415 Week 1 DQ 2 Poverty and Health (Ash) HCA 415 Week 2 DQ 1 U.S. Health Care System Critical Issues (Ash) HCA 415 Week 2 DQ 2 Role of Prevention in Health Status (Ash) HCA 415 Week 2 Assignment Public Health and the Law (Ash) HCA 415 Week 3 DQ 1 Tools for Assessing Community Health (Ash) HCA 415 Week 3 DQ 2 Essential Ser...

  20. Stabilised coal ash studies in Italy

    Energy Technology Data Exchange (ETDEWEB)

    Relini, G.; Dinelli, G.; Sampaolo, A. [Universita di Genova, Genova (Italy). Instituto Zoologica

    1995-06-01

    ENEL ran an experiment at the Torrevaldaliga power plant, near Rome, on the use of coal ash in concrete blocks for artificial habitats. Two reefs were submerged in different tanks with running sea water. The ash blocks consisted of fly ash, bottom ash, hydrated lime and water, while the concrete blocks consisted of pozzolanic cement, sand, and gravel. After two years the ash blocks had, if anything, strengthened, and showed no signs of weathering, volume change or swelling. No significant leaching was discovered either. The fauna and flora of the ash blocks was more luxuriant than that of the concrete blocks as well. 13 refs., 2 figs., 6 tabs.

  1. Characterisation of Turkish fly ashes

    Energy Technology Data Exchange (ETDEWEB)

    Bayat, O. [Cukurova University, Adana (Turkey). Mining Engineering Dept.

    1998-07-01

    The mineralogical, morphological, physical and chemical properties of 7 fly ashes from coal fields in Turkey are compared. The mineral matter in the fly ashes, determined by X-ray diffraction, is dominated by anhydride, lime, quartz and hematite + ferrite spinel. The three low-calcium ashes have the typical, relatively simple, crystalline phase Q, M, H and FS. The high-calcium fly ashes have the most complex assemblage of crystalline phases. The much higher calcium concentrations in these samples result in the formation of lime (CaO), melilite ((Ca, Na){sub 2}(Mg,Al,Fe)(Si,Al){sub 2}O{sub 7}) and merwinite. The presence of anhydride in all samples indicates that the high activity of calcium not only promotes the formation of sulfates from calcite but also the dehydration of gypsum during and after combustion, which occurs at temperatures above 400-500{degree}C. It is important to understand the interaction of high-calcium fly ashes with water occurring in Portland cement (C{sub 3}A,C{sub 2}S), Ah, which hydrates to give gypsum and lime, with the latter hydrating to give the Ca(OH){sub 2} solutions that promote pozzolonic reactions. Some of the particles comprised irregularly formed, vesicular particles with some well-formed individual spheres in Catalagzi and Tuncbilek fly ashes. About 55-80 wt% was less than 45 {mu}m in size for Yatagan, Soma, Yenikoy and Afsin-Elbistan fly ashes. The fly ashes were mainly composed of CaO, SiO{sub 2} and Al{sub 2}O{sub 3}. They have a potential use in wastewater treatment since they can be easily obtained in large quantities at low price or even free. The chemical and mineralogical compositions of the high-calcium Turkish fly ashes investigated make them a good binding agent and a possible substitute for slags, pozzolana and gypsum in the amelioration of clinker. 53 refs., 10 figs., 5 tabs.

  2. Ash in fire affected ecosystems

    Science.gov (United States)

    Pereira, Paulo; Jordan, Antonio; Cerda, Artemi; Martin, Deborah

    2015-04-01

    Ash in fire affected ecosystems Ash lefts an important footprint in the ecosystems and has a key role in the immediate period after the fire (Bodi et al., 2014; Pereira et al., 2015). It is an important source of nutrients for plant recover (Pereira et al., 2014a), protects soil from erosion and controls soil hydrological process as runoff, infiltration and water repellency (Cerda and Doerr, 2008; Bodi et al., 2012, Pereira et al., 2014b). Despite the recognition of ash impact and contribution to ecosystems recuperation, it is assumed that we still have little knowledge about the implications of ash in fire affected areas. Regarding this situation we wanted to improve our knowledge in this field and understand the state of the research about fire ash around world. The special issue about "The role of ash in fire affected ecosystems" currently in publication in CATENA born from the necessity of joint efforts, identify research gaps, and discuss future cooperation in this interdisciplinary field. This is the first special issue about fire ash in the international literature. In total it will be published 10 papers focused in different aspects of the impacts of ash in fire affected ecosystems from several parts of the world: • Fire reconstruction using charcoal particles (Burjachs and Espositio, in press) • Ash slurries impact on rheological properties of Runoff (Burns and Gabet, in press) • Methods to analyse ash conductivity and sorbtivity in the laboratory and in the field (Balfour et al., in press) • Termogravimetric and hydrological properties of ash (Dlapa et al. in press) • Effects of ash cover in water infiltration (Leon et al., in press) • Impact of ash in volcanic soils (Dorta Almenar et al., in press; Escuday et al., in press) • Ash PAH and Chemical extracts (Silva et al., in press) • Microbiology (Barreiro et al., in press; Lombao et al., in press) We believe that this special issue will contribute importantly to the better understanding of

  3. Squeezing wetting and nonwetting liquids

    OpenAIRE

    Samoilov, V. N.; Persson, B. N. J.

    2004-01-01

    We present molecular-dynamics results for the squeezing of octane (C8H18) between two approaching solid elastic walls with different wetting properties. The interaction energy between the octane bead units and the solid walls is varied from a very small value (1 meV), corresponding to a nonwetting surface with a very large contact angle (nearly 180 degrees), to a high value (18.6 meV) corresponding to complete wetting. When at least one of the solid walls is wetted by octane we observe well d...

  4. An Improved Operational Volcanic Ash Dispersion Modelling System for the Wellington VAAC

    Science.gov (United States)

    Shucksmith, Paul; Davis, Cory; Soltanzadeh, Iman; Bernard, Matthieu; Rye, Graham

    2015-04-01

    The Meteorological Service of New Zealand's (MetService's) responsibilities as a Volcanic Ash Advisory Centre (VAAC) require the operational use of volcanic ash dispersion and transport models to provide guidance for issuing Volcanic Ash Advisories in the event of volcanic eruptions. The operational volcanic ash dispersion modelling system currently in use at MetService is based on the PUFF model (Searcy et al., 1998) driven by GFS NWP data. This system possesses several shortcomings, most notably the lack of quantitative concentration output for quantitative comparison with satellite observations, no accounting for wet deposition of ash and the use of low resolution NWP input from a single model. To overcome these shortcomings, a new modelling system has been developed, built around the HYSPLIT model (developed by NOAA's Air Resources Laboratory) driven with NWP from three different models: IFS, GFS and WRF. Eruption parameters (duration, plume height and mass eruption rate) are provided from a set of defaults, spanning a range of eruption sizes, for each volcano -- at present taken from the USGS eruption parameter database (Mastin et al., 2009) -- until observations of the eruption become available to specify these. The system is operated through a web interface which allows simulations to be triggered by forecasters simply and quickly and also provides graphical output of mass loading. Further visualization is provided through integration with IBL's Visual Weather product which allows easy comparison with satellite observations as well as the editing and publishing of Volcanic Ash Advisories and Volcanic Ash Graphics. Early results indicate that in general, differences between ash dispersion forecasts from the two global models are slight in comparison to the differences between the global models and the limited area WRF. A number of eruption case studies will be presented, demonstrating the multi-model/multi-parameter ensemble output and assessment of model

  5. Properties of cement-fly ash grout admixed with bentonite, silica fume, or organic fiber

    International Nuclear Information System (INIS)

    A detailed laboratory study was conducted to investigate the properties of cement-fly ash grout mixtures as barriers for isolation of hazardous and low-level radioactive wastes. In the grout studied, fly ash was used to replace 30 percent by mass of cement. Three additives including bentonite, silica fume, and polypropylene fiber were used individually in the grout mixes to improve the properties of the grouts in different aspects. The flowability, bleeding, and setting time of freshly mixed grouts were determined; and the unconfined compressive strength, pore size distribution, and water permeability were determined for hardened grouts at various curing durations up to 120 days. Finally, the durability of cement-fly ash grouts was carefully examined in terms of the changes in their physical properties after different levels of exposure to sulfate attack and wet-dry cycles

  6. Rising from the ashes: Coal ash in recycling and construction

    Energy Technology Data Exchange (ETDEWEB)

    Naquin, D.

    1998-02-01

    Beneficial Ash Management (BAM, Clearfield, Pa.) has won an environmental award for its use of ash and other waste to fight acid mine drainage. The company`s workers take various waste materials, mainly fly ash from coal-burning plants, to make a cement-like material or grouting, says Ernest Roselli, BAM president. The grouting covers the soil, which helps prevent water from contacting materials. This, in turn, helps control chemical reactions, reducing or eliminating formation of acid mine drainage. The company is restoring the 1,400-acre Bark Camp coal mine site near Penfield in Clearfield County, Pa. Under a no-cost contract with the state of Pennsylvania, BAM is using boiler slag, causticizing byproducts (lime) and nonreclaimable clarifier sludge from International Paper Co. (Erie, Pa.). The mine reclamation techniques developed and monitored at the site include using man-made wetlands to treat acid mine drainage and testing anhydrous ammonia as a similar treatment agent. BAM researches and tests fly ash mixed with lime-based activators as fill material for land reclamation, and develops and uses artificial soil material from paper mill and tannery biosolids.

  7. Gasification of high ash, high ash fusion temperature bituminous coals

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Guohai; Vimalchand, Pannalal; Peng, WanWang

    2015-11-13

    This invention relates to gasification of high ash bituminous coals that have high ash fusion temperatures. The ash content can be in 15 to 45 weight percent range and ash fusion temperatures can be in 1150.degree. C. to 1500.degree. C. range as well as in excess of 1500.degree. C. In a preferred embodiment, such coals are dealt with a two stage gasification process--a relatively low temperature primary gasification step in a circulating fluidized bed transport gasifier followed by a high temperature partial oxidation step of residual char carbon and small quantities of tar. The system to process such coals further includes an internally circulating fluidized bed to effectively cool the high temperature syngas with the aid of an inert media and without the syngas contacting the heat transfer surfaces. A cyclone downstream of the syngas cooler, operating at relatively low temperatures, effectively reduces loading to a dust filtration unit. Nearly dust- and tar-free syngas for chemicals production or power generation and with over 90%, and preferably over about 98%, overall carbon conversion can be achieved with the preferred process, apparatus and methods outlined in this invention.

  8. Characterization of fly ash from low-sulfur and high-sulfur coal sources: Partitioning of carbon and trace elements with particle size

    Science.gov (United States)

    Hower, J.C.; Trimble, A.S.; Eble, C.F.; Palmer, C.A.; Kolker, A.

    1999-01-01

    Fly ash samples were collected in November and December of 1994, from generating units at a Kentucky power station using high- and low-sulfur feed coals. The samples are part of a two-year study of the coal and coal combustion byproducts from the power station. The ashes were wet screened at 100, 200, 325, and 500 mesh (150, 75, 42, and 25 ??m, respectively). The size fractions were then dried, weighed, split for petrographic and chemical analysis, and analyzed for ash yield and carbon content. The low-sulfur "heavy side" and "light side" ashes each have a similar size distribution in the November samples. In contrast, the December fly ashes showed the trend observed in later months, the light-side ash being finer (over 20 % more ash in the -500 mesh [-25 ??m] fraction) than the heavy-side ash. Carbon tended to be concentrated in the coarse fractions in the December samples. The dominance of the -325 mesh (-42 ??m) fractions in the overall size analysis implies, though, that carbon in the fine sizes may be an important consideration in the utilization of the fly ash. Element partitioning follows several patterns. Volatile elements, such as Zn and As, are enriched in the finer sizes, particularly in fly ashes collected at cooler, light-side electrostatic precipitator (ESP) temperatures. The latter trend is a function of precipitation at the cooler-ESP temperatures and of increasing concentration with the increased surface area of the finest fraction. Mercury concentrations are higher in high-carbon fly ashes, suggesting Hg adsorption on the fly ash carbon. Ni and Cr are associated, in part, with the spinel minerals in the fly ash. Copyright ?? 1999 Taylor & Francis.

  9. Use of Incineration MSW Ash: A Review

    OpenAIRE

    Charles H. K. Lam; Alvin W. M. Ip; John Patrick Barford; Gordon McKay

    2010-01-01

    This study reviews the characteristics of municipal solid waste incineration (MSWI) ashes, with a main focus on the chemical properties of the ashes. Furthermore, the possible treatment methods for the utilization of ash, namely, separation processes, solidification/stabilization and thermal processes, are also discussed. Seven types of MSWI ash utilization are reviewed, namely, cement and concrete production, road pavement, glasses and ceramics, agriculture, stabilizing agent, adsorbents and...

  10. Transcriptomic signatures of ash (Fraxinus spp. phloem.

    Directory of Open Access Journals (Sweden)

    Xiaodong Bai

    Full Text Available BACKGROUND: Ash (Fraxinus spp. is a dominant tree species throughout urban and forested landscapes of North America (NA. The rapid invasion of NA by emerald ash borer (Agrilus planipennis, a wood-boring beetle endemic to Eastern Asia, has resulted in the death of millions of ash trees and threatens billions more. Larvae feed primarily on phloem tissue, which girdles and kills the tree. While NA ash species including black (F. nigra, green (F. pennsylvannica and white (F. americana are highly susceptible, the Asian species Manchurian ash (F. mandshurica is resistant to A. planipennis perhaps due to their co-evolutionary history. Little is known about the molecular genetics of ash. Hence, we undertook a functional genomics approach to identify the repertoire of genes expressed in ash phloem. METHODOLOGY AND PRINCIPAL FINDINGS: Using 454 pyrosequencing we obtained 58,673 high quality ash sequences from pooled phloem samples of green, white, black, blue and Manchurian ash. Intriguingly, 45% of the deduced proteins were not significantly similar to any sequences in the GenBank non-redundant database. KEGG analysis of the ash sequences revealed a high occurrence of defense related genes. Expression analysis of early regulators potentially involved in plant defense (i.e. transcription factors, calcium dependent protein kinases and a lipoxygenase 3 revealed higher mRNA levels in resistant ash compared to susceptible ash species. Lastly, we predicted a total of 1,272 single nucleotide polymorphisms and 980 microsatellite loci, among which seven microsatellite loci showed polymorphism between different ash species. CONCLUSIONS AND SIGNIFICANCE: The current transcriptomic data provide an invaluable resource for understanding the genetic make-up of ash phloem, the target tissue of A. planipennis. These data along with future functional studies could lead to the identification/characterization of defense genes involved in resistance of ash to A. planipennis

  11. Latest technological experience of the removal of mercury in flue gas and the management of fly ash from MSW incinerator

    International Nuclear Information System (INIS)

    Recently, mercury emissions from municipal solid waste incineration plants became of concern. As a result, several mercury removal systems have been developed and installed in the flue gas stream of incineration plants in Japan. Both a liquid chelating agent injection system and a sodium hypochlorite injection system at the wet scrubber have achieved more than 90% removal of mercury. Fly ash from MSW incinerators contains volatile heavy metals such as cadmium, lead and arsenic and leaches these materials to the ground water. Three fly ash management technologies have been established. These are solidification of fly ash with cement, neutralization by flue gas and electric vitrification systems. The purpose of this paper is to describe the status of mercury emission control and fly ash management technologies in Japan

  12. Uranium content of coal ashes from Southern Brazil coal fueled power stations, by the fission track registration technique

    International Nuclear Information System (INIS)

    The feasibility of the application of the fission track registration technique for the determination of uranium in coal ashes was shown. The wet method was employed using as detector the Makrofol KG=10 μm, manufactured by Bayer. The coal ashes were originated from coal-fueled power stations localized in Southern Brazil. The results obtained ranged from 10 to 27 mg U/kg. Since the total error variation was from 18,4% to 23,8%, the method used was considered excellent. The determination of the uranium content in coal ashes is of considerable interest in environmental control in power stations, in their vicinity and wherever these ashes are used or stored. The technique used is the work proved to be very appropriate for the purpose aimed at. (Author)

  13. Interspecific Proteomic Comparisons Reveal Ash Phloem Genes Potentially Involved in Constitutive Resistance to the Emerald Ash Borer

    OpenAIRE

    Justin G A Whitehill; Alexandra Popova-Butler; Green-Church, Kari B.; Koch, Jennifer L; Herms, Daniel A.; Pierluigi Bonello

    2011-01-01

    The emerald ash borer (Agrilus planipennis) is an invasive wood-boring beetle that has killed millions of ash trees since its accidental introduction to North America. All North American ash species (Fraxinus spp.) that emerald ash borer has encountered so far are susceptible, while an Asian species, Manchurian ash (F. mandshurica), which shares an evolutionary history with emerald ash borer, is resistant. Phylogenetic evidence places North American black ash (F. nigra) and Manchurian ash in ...

  14. Wet Gas Compressor Surge Detection

    OpenAIRE

    Jellum, Marie Rennemo

    2013-01-01

    The development of wet gas compressors for installation subsea is key to increase the recovery of oil and gas from the Norwegian Continental Shelf. Safe operation of the compressor depends on understanding of how wet gas affects the behavior of the machine. The compressor operating range is limited by stall and surge, and it is therefore particularly important to determine how liquid will affect the inception of these phenomena. Measuring pressure transients within the compressor or in the in...

  15. Subsea Wet Gas Compressor Dynamics

    OpenAIRE

    Perez Aguilera, Luber Carlui

    2013-01-01

    In this Thesis the Aspen HYSYS dynamic functionalities were explored in order to build a dynamic Wet Gas Compressor model. In particular the Automation feature was used to implement two different correction methods, interpolation and Wood?s correction, that accounts for wet gas impact on compression performance, in dynamic-state. This was done through the creation of a VBA script in Microsoft Excel. The implementation of the correction methods showed to be fast and effective.The HYSYS dynamic...

  16. Reentrant Wetting of Network Fluids

    Science.gov (United States)

    Bernardino, N. R.; Telo da Gama, M. M.

    2012-09-01

    We use a simple mesoscopic Landau-Safran theory of network fluids to show that a reentrant phase diagram, in the “empty liquid” regime, leads to nonmonotonic surface tension and reentrant wetting, as previously reported for binary mixtures. One of the wetting transitions is of the usual kind, but the low temperature transition may allow the display of the full range of fluctuation regimes predicted by renormalization group theory.

  17. Transport kinetics of wetting layers

    OpenAIRE

    Herminghaus, Stephan; Paatzsch, Thomas; Häcker, T.; Leiderer, Paul

    1995-01-01

    The transport kinetics of wetting layers of ethanol and propane on silver substrates is investigated by monitoring the temporal decay of pulsed-laser-induced spatial thickness modulations. Our method allows to distinguish between different transport mechanisms, such as direct exchange with the vapour phase, viscous flow within the wetting layer, or surface diffusion. In either ease, the activation energy found for the lateral transport points to viscous flow as the dominant mechanism in the i...

  18. Wetting film dynamics and stability

    OpenAIRE

    Radoev, B.; Stoeckelhuber, K. W.; Tsekov, R.; Letocart, P

    2011-01-01

    Although the wetting films are similar in many aspects to other thin liquid films, there are some differences in their behavior, too. In contrast to soap and emulsion films, whose surfaces are homogeneous, solid substrates of wetting films are heterogeneous as a rule, unless special measures for their homogenization are taken. Here we mean primarily heterogeneous distribution of surface energy leading to existence of hydrophobic domains on hydrophilic surfaces and vice versa. As is known, suc...

  19. Wetting of polymer covered surfaces

    OpenAIRE

    Halperin, A.; De Gennes, P.G.

    1986-01-01

    We consider solid surfaces, partly covered with flexible, neutral, linear polymers (by adsorption or by grafting), wetted by a liquid which is a good solvent of the poymer. We give formulae for the spreading coefficient S as a function of chain length, solvent quality and adsorption strength. We also discuss the wetting films obtained in spreading a droplet of (non volatile) solvent : the equilibrium thickness e of the film is a compromise between S (favouring thin films) and the coil entropi...

  20. Wet Gas Compression : Impeller Rig

    OpenAIRE

    Amundsen, Siren Carstens

    2009-01-01

    Wet gas compression technology is of great value to the oil and gas industry for boosting of unprocessed well stream and to reduce investment costs related to equipment and personnel. The growing interest in wet gas compression leads to a general request for accurate performance calculation procedures and proper measurement techniques for multiphase flow metering in compressors. An impeller rig for examination of single-phase and multiphase performance and aerodynamic stability is under con...

  1. Wet flue gas desulfurization processes

    OpenAIRE

    Hayrunnisa Çavuşoğlu; Mustafa Şahin Gülaboğlu

    2013-01-01

    The wet flue gas desulfurization process is widely used for the treatment of exhaust gases in power stations. Due to its high level of effectiveness over the already available processes, it has also been the mostly preferred method by industry. Its high SO2 removal efficiency, wide applicability of absorption chemicals and the ease of the chemical process handling which does not require comprehensive konowledge are among the main advantages of this process. In this article, various wet flue g...

  2. Use of ashes and ash-and-slad wastes in construction

    Directory of Open Access Journals (Sweden)

    P. Lahtinen

    2011-06-01

    Full Text Available The use of ash waste saves expenses on main materials without compromising the quality of the product, while solving the problem of disposal of ash materials. The aim of this work is classification of ashes and evaluation its use in construction.Classification of ash-and-slad wastes based on type of burned coal, way of incineration, flame temperature, way of ash disposal is made. The chemical composition and behavior of shale ash, its main deposits, its advantages as a mineral concrete admixture are analysed. Fly ashes are divided into siliceous ashes and basic ashes.Various application areas of ash-and-slad wastes in construction are considered, the examples of its use are given.

  3. DURABILITY OF HARDENED FLY ASH PASTE

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The mechanical properties and durability ( mainly frost-resistance and carbonation resistance ) of fly ash-CaO-CaSO4 .2H2O hardened paste are studied. The relationship among durability of harden ed fly ash paste, the quantity and distribution of hydrates and the initial p aste texture of hardened fly ash paste is presented.

  4. Method of solidifying burnt ash

    International Nuclear Information System (INIS)

    Unsaturated polyester resins may not sometime be hardened satisfactorily by means of burnt ashes. It has been found that this dues to oxygen contained in the burnt ashes. In addition, it has also been found that oxygen hindering condensation is not contained in voids of the ashes but mainly adsorbed on carbon as the ash ingredient. In view of the above, before injection of the resin, the pressure inside the vessel is once reduced and a nitrogen gas is charged in place of air. Unsaturated polyester resins with acid value as low as possible are preferred and those having acid value of less than 5 are used. An oxydizer comprises a polymerizer initiator and a polymerization promoter, which is mixed with a hardening agent or solidifying agent by an inline mixer. A customary steel drum is used as a solidifying vessel and cement mortar is lined to the inside thereof so as to easily attain adhesion with the hardening agent. This enables to obtain solidification products of high strength in a simple step. (T.M.)

  5. Radioactivity of wood ash; Puun tuhkan radioaktiivisuus

    Energy Technology Data Exchange (ETDEWEB)

    Rantavaara, A.; Moring, M

    2000-01-01

    STUK (Finnish Radiation and Nuclear Safety Authority) has investigated natural and artificial radioactivity in wood ash and radiation exposure from radionuclides in ash since 1996. The aim was to consider both handling of ash and different ways of using ash. In all 87 ash samples were collected from 22 plants using entirely or partially wood for their energy production in 1996-1997. The sites studied represented mostly chemical forest industry, sawmills or district heat production. Most plants used fluidised bed combustion technique. Samples of both fly ash and bottom ash were studied. The activity concentrations of radionuclides in samples of, e.g., dried fly ash from fuel containing more than 80% wood were determined. The means ranged from 2000 to less than 50 Bq kg{sup -1}, in decreasing order: {sup 137}Cs, {sup 40}K, {sup 90}Sr, {sup 210}Pb,{sup 226}Ra, {sup 232}Th, {sup 134}Cs, {sup 235}U. In bott radionuclide contents decreased in the same order as in fly ash, but were smaller, and {sup 210}Pb was hardly detectable. The NH{sub 4}Ac extractable fractions of activities for isotopes of alkaline elements (K, Cs) in bottom ash were lower than in fly ash, whereas solubility of heavier isotopes was low. Safety requirements defined by STUK in ST-guide 12.2 for handling of peat ash were fulfilled at each of the sites. Use of ash for land-filling and construction of streets was minimal during the sampling period. Increasing this type of ash use had often needed further investigations, as description of the use of additional materials that attenuate radiation. Fertilisation of forests with wood ash adds slightly to the external irradiation in forests, but will mostly decrease doses received through use of timber, berries, mushrooms and game meat. (orig.)

  6. Coal ash artificial reef demonstration

    International Nuclear Information System (INIS)

    This experimental project evaluated the use of coal ash to construct artificial reefs. An artificial reef consisting of approximately 33 tons of cement-stabilized coal ash blocks was constructed in approximately 20 feet of water in the Gulf of Mexico approximately 9.3 miles west of Cedar Key, Florida. The project objectives were: (1) demonstrate that a durable coal ash/cement block can be manufactured by commercial block-making machines for use in artificial reefs, and (2) evaluate the possibility that a physically stable and environmentally acceptable coal ash/cement block reef can be constructed as a means of expanding recreational and commercial fisheries. The reef was constructed in February 1988 and biological surveys were made at monthly intervals from May 1988 to April 1989. The project provided information regarding: Development of an optimum design mix, block production and reef construction, chemical composition of block leachate, biological colonization of the reef, potential concentration of metals in the food web associated with the reef, acute bioassays (96-hour LC50). The Cedar Key reef was found to be a habitat that was associated with a relatively rich assemblage of plants and animals. The reef did not appear to be a major source of heavy metals to species at various levels of biological organization. GAI Consultants, Inc (GAI) of Monroeville, Pennsylvania was the prime consultant for the project. The biological monitoring surveys and evaluations were performed by Environmental Planning and Analysis, Inc. of Tallahassee, Florida. The chemical analyses of biological organisms and bioassay elutriates were performed by Savannah Laboratories of Tallahassee, Florida. Florida Power Corporation of St. Petersburg, Florida sponsored the project and supplied ash from their Crystal River Energy Complex

  7. Use of Incineration MSW Ash: A Review

    Directory of Open Access Journals (Sweden)

    Charles H. K. Lam

    2010-07-01

    Full Text Available This study reviews the characteristics of municipal solid waste incineration (MSWI ashes, with a main focus on the chemical properties of the ashes. Furthermore, the possible treatment methods for the utilization of ash, namely, separation processes, solidification/stabilization and thermal processes, are also discussed. Seven types of MSWI ash utilization are reviewed, namely, cement and concrete production, road pavement, glasses and ceramics, agriculture, stabilizing agent, adsorbents and zeolite production. The practical use of MSWI ash shows a great contribution to waste minimization as well as resources conservation.

  8. Adhesion Strength of Biomass Ash Deposits

    DEFF Research Database (Denmark)

    Laxminarayan, Yashasvi; Jensen, Peter Arendt; Wu, Hao;

    2016-01-01

    Ash deposition on boiler surfaces is a major problem encountered during biomass combustion. Ash deposition adversely influences the boiler efficiency, may corrode heat transfer surfaces, and may even completely block flue gas channels in severe cases, causing expensive unscheduled boiler shutdowns....... Therefore, timely removal of ash deposits is essential for optimal boiler operation. In order to improve the qualitative and quantitative understanding of deposit shedding in boilers, this study investigates the shear adhesion strength of biomass ash deposits on superheater tubes. Artificial biomass ash...

  9. Ash chemistry in MSW incineration plants: Advanced characterization and thermodynamic considerations

    Energy Technology Data Exchange (ETDEWEB)

    Frandsen, Flemming J.; Laursen, Karin; Arvelakis, S. (and others)

    2004-07-15

    A number of ash samples where collected at four Danish municipal solid waste incineration (MSWI) plants. Samples of bottom ash/slag, 2nd-3rd pass ashes and ESP/E-filter ash were collected at the plants. The ashes were analyzed by a number of standard chemical analyses, and a number of advanced analytical techniques. The wet chemical analyses of the different ash fractions revealed that residual ash is formed on the grate by interaction of the main ash forming elements, Al, Ca, Fe and Si. Some of this ash is entrained from the grate and carried with the flue gas along the flue gas duct, where volatile species of K, Na, Pb, Zn, Cl and S starts to condense heterogeneously on the fly ash, thereby causing a dilution of the main ash forming elements. When compared plant-by-plant, the ash chemical analyses showed that the plant with the highest S-content in the fly ash is the one with the most often operational problems in relation to deposition, while a high Cl-content is indicative of a high corrosive potential. An existing Computer Controlled Scanning Electron Microscopy (CCSEM) algorithm was extended with chemical classes covering Pb- and Zn-rich phases. This has made it possible also to analyze MSW-derived ashes by use of CCSEM. Representative samples of 2nd-3rd pass and ESP/E-filter ashes from the four plants have been analyzed by Quantitative X-Ray Diffraction (QXRD) analysis. Only a few crystalline phases were identified: KCl, NaCl, CaSO{sub 4}, SiO{sub 2} and CaCO{sub 3} being the main ones. No crystalline phases containing Pb or Zn were identified by QXRD. A comparison between CCSEM and QXRD revealed the expected surface nature of the CCSEM analysis. Samples of 2nd-3rd pass and ESP/E-filter ash from the four plants where investigated for melting behavior in the Simultaneous Thermal Analyzer (STA). It was shown that it is possible to quantify the melting behavior of these ashes, and that the melting goes on in two steps (salts followed by silicates/oxides). The

  10. Engineering Behavior and Characteristics of Wood Ash and Sugarcane Bagasse Ash

    Directory of Open Access Journals (Sweden)

    Francisco Grau

    2015-10-01

    Full Text Available Biomasses are organic materials that are derived from any living or recently-living structure. Plenty of biomasses are produced nationwide. Biomasses are mostly combusted and usually discarded or disposed of without treatment as biomass ashes, which include wood and sugarcane bagasse ashes. Thus, recycling or treatment of biomass ashes leads to utilizing the natural materials as an economical and environmental alternative. This study is intended to provide an environmental solution for uncontrolled disposal of biomass ashes by way of recycling the biomass ash and replacing the soils in geotechnical engineering projects. Therefore, in this study, characteristic tests of wood and sugarcane bagasse ashes that are considered the most common biomass ashes are conducted. The test of chemical compositions of biomass ashes is conducted using energy dispersive X-ray spectroscopy (EDS, and Scanning Electron Microscope (SEM, and heavy metal analysis is also conducted. Engineering behaviors including hydraulic conductivity, constrained modulus and shear modulus are examined. Also, coal fly ash Class C is used in this study for comparison with biomass ashes, and Ottawa 20/30 sands containing biomass ashes are examined to identify the soil replacement effect of biomass ashes. The results show that the particle sizes of biomass ashes are halfway between coal fly ash Class C and Ottawa 20/30 sand, and biomass ashes consist of a heterogeneous mixture of different particle sizes and shapes. Also, all heavy metal concentrations were found to be below the US Environmental Protection Agency (EPA maximum limit. Hydraulic conductivity values of Ottawa 20/30 sand decrease significantly when replacing them with only 1%–2% of biomass ashes. While both the constrained modulus and shear modulus of biomass ashes are lower than Ottawa 20/30 sand, those of mixtures containing up to 10% biomass ashes are little affected by replacing the soils with biomass ashes.

  11. Identifying glass compositions in fly ash

    Science.gov (United States)

    Aughenbaugh, Katherine; Stutzman, Paul; Juenger, Maria

    2016-01-01

    In this study, four Class F fly ashes were studied with a scanning electron microscope; the glassy phases were identified and their compositions quantified using point compositional analysis with k-means clustering and multispectral image analysis. The results showed that while the bulk oxide contents of the fly ashes were different, the four fly ashes had somewhat similar glassy phase compositions. Aluminosilicate glasses (AS), calcium aluminosilicate glasses (CAS), a mixed glass, and, in one case, a high iron glass were identified in the fly ashes. Quartz and iron crystalline phases were identified in each fly ash as well. The compositions of the three main glasses identified, AS, CAS, and mixed glass, were relatively similar in each ash. The amounts of each glass were varied by fly ash, with the highest calcium fly ash containing the most of calcium-containing glass. Some of the glasses were identified as intermixed in individual particles, particularly the calcium-containing glasses. Finally, the smallest particles in the fly ashes, with the most surface area available to react in alkaline solution, such as when mixed with portland cement or in alkali-activated fly ash, were not different in composition than the large particles, with each of the glasses represented. The method used in the study may be applied to a fly ash of interest for use as a cementing material in order to understand its potential for reactivity.

  12. Identifying glass compositions in fly ash

    Directory of Open Access Journals (Sweden)

    Katherine eAughenbaugh

    2016-01-01

    Full Text Available In this study, four Class F fly ashes were studied with a scanning electron microscope; the glassy phases were identified and their compositions quantified using point compositional analysis with k-means clustering and multispectral image analysis. The results showed that while the bulk oxide contents of the fly ashes were different, the four fly ashes had somewhat similar glassy phase compositions. Aluminosilicate glasses (AS, calcium aluminosilicate glasses (CAS, a mixed glass, and, in one case, a high iron glass were identified in the fly ashes. Quartz and iron crystalline phases were identified in each fly ash as well. The compositions of the three main glasses identified, AS, CAS, and mixed glass, were relatively similar in each ash. The amounts of each glass were varied by fly ash, with the highest calcium fly ash containing the most of calcium-containing glass. Some of the glasses were identified as intermixed in individual particles, particularly the calcium-containing glasses. Finally, the smallest particles in the fly ashes, with the most surface area available to react in alkaline solution, such as when mixed with portland cement or in alkali-activated fly ash, were not different in composition than the large particles, with each of the glasses represented. The method used in the study may be applied to a fly ash of interest for use as a cementing material in order to understand its potential for reactivity.

  13. ACAA fly ash basics: quick reference card

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    Fly ash is a fine powdery material created when coal is burned to generate electricity. Before escaping into the environment via the utility stacks, the ash is collected and may be stored for beneficial uses or disposed of, if necessary. The use of fly ash provides environmental benefits, such as the conservation of natural resources, the reduction of greenhouse gas emissions and eliminating the needed for ash disposal in landfills. It is also a valuable mineral resource that is used in construction and manufacturing. Fly ash is used in the production of Portland cement, concrete, mortars and stuccos, manufactured aggregates along with various agricultural applications. As mineral filler, fly ash can be used for paints, shingles, carpet backing, plastics, metal castings and other purposes. This quick reference card is intended to provide the reader basic source, identification and composition, information specifically related to fly ash.

  14. High performance of treated and washed MSWI bottom ash granulates as natural aggregate replacement within earth-moist concrete.

    Science.gov (United States)

    Keulen, A; van Zomeren, A; Harpe, P; Aarnink, W; Simons, H A E; Brouwers, H J H

    2016-03-01

    Municipal solid waste incineration bottom ash was treated with specially designed dry and wet treatment processes, obtaining high quality bottom ash granulate fractions (BGF) suitable for up to 100% replacement of natural gravel in concrete. The wet treatment (using only water for separating and washing) significantly lowers the leaching of e.g. chloride and sulfate, heavy metals (antimony, molybdenum and copper) and dissolved organic carbon (DOC). Two potential bottom ash granulate fractions, both in compliance with the standard EN 12620 (aggregates for concrete), were added into earth-moist concrete mixtures. The fresh and hardened concrete physical performances (e.g. workability, strength and freeze-thaw) of high strength concrete mixtures were maintained or improved compared with the reference mixtures, even after replacing up to 100% of the initial natural gravel. Final element leaching of monolithic and crushed granular state BGF containing concretes, showed no differences with the gravel references. Leaching of all mixtures did not exceed the limit values set by the Dutch Soil Quality Degree. In addition, multiple-life-phase emission (pH static test) for the critical elements of input bottom ash, bottom ash granulate (BGF) and crushed BGF containing concrete were assessed. Simulation pH lowering or potential carbonation processes indicated that metal (antimony, barium, chrome and copper) and sulfate element leaching behavior are mainly pH dominated and controlled, although differ in mechanism and related mineral abundance. PMID:26856445

  15. Experimental Analysis of Fly Ash & Coir Fiber Mix Cement Concrete for Rigid Pavement

    Directory of Open Access Journals (Sweden)

    Er. Amit Kumar Ahirwar

    2015-04-01

    Full Text Available In India Thermal power plants which use pounded coal as a fuel, generates million tones of fly ash every year as a waste. Conservative clearance of this material which gets easily air-borne and constitutes a serious health hazards to the community, is an expensive operation. A part from this compacted fly ash can be used in embankments, road sub-bases and also for structural fills. The major drawbacks of such materials are their limited load carrying capacity and poor settlement characteristics. The concert of such materials can substantially be improved by introducing reinforcing element in the direction of improving its compressive and flexural strength for superior durability. Use of natural materials such as Jute, coir and bamboo, as reinforcing materials to fly ash are very cheap and they are locally available in huge quantity, of all the natural fibers, coir has the greatest tearing strength and it retains this property even in wet conditions. In this framework a composite with fly ash, conventional concrete and treated coconut fibers, available in plenty in rural areas of India have been investigated. These composites can be a good proposition and with this, experimental investigation to study the effects of replacement of cement (by volume with different percentages of fly ash and the effects of addition of processed natural coconut fiber on flexural strength, compressive strength, splitting tensile strength and modulus of elasticity was taken up. AS per IRC, A Design mix proportion was designed for the normally popular M30 concrete for pavement construction in India. In this, Cement was replaced with percentages (10, 20, 30 and 40% of Class C fly ash and of coconut fibers (0.50 and 1.0 % having 40 mm length were used. Test results show that the replacement of 43 grades ordinary Portland cement with fly ash showed an increase in compressive strength and flexural strength for the chosen mix proportion.

  16. Thermal and hydrometallurgical recovery methods of heavy metals from municipal solid waste fly ash

    International Nuclear Information System (INIS)

    Highlights: • MSW fly ash was thermally and hydrometallurgically treated to remove heavy metals. • More than 90% of easy volatile heavy metals (Cd and Pb) were removed thermally. • More than 90% of Cd, Cr, Cu an Zn were removed by alkaline – acid leaching. • The best results were obtained for the solution of 3 M NaOH and 2 M H2SO4. - Abstract: Heavy metals in fly ash from municipal solid waste incinerators are present in high concentrations. Therefore fly ash must be treated as a hazardous material. On the other hand, it may be a potential source of heavy metals. Zinc, lead, cadmium, and copper can be relatively easily removed during the thermal treatment of fly ash, e.g. in the form of chlorides. In return, wet extraction methods could provide promising results for these elements including chromium and nickel. The aim of this study was to investigate and compare thermal and hydrometallurgical treatment of municipal solid waste fly ash. Thermal treatment of fly ash was performed in a rotary reactor at temperatures between 950 and 1050 °C and in a muffle oven at temperatures from 500 to 1200 °C. The removal more than 90% was reached by easy volatile heavy metals such as cadmium and lead and also by copper, however at higher temperature in the muffle oven. The alkaline (sodium hydroxide) and acid (sulphuric acid) leaching of the fly ash was carried out while the influence of temperature, time, concentration, and liquid/solid ratio were investigated. The combination of alkaline-acidic leaching enhanced the removal of, namely, zinc, chromium and nickel

  17. Thermal and hydrometallurgical recovery methods of heavy metals from municipal solid waste fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Kuboňová, L., E-mail: lenka.kubonova@vsb.cz [VSB – Technical University of Ostrava, 17. listopadu 15/2172, 708 33 Ostrava (Czech Republic); Langová, Š. [VSB – Technical University of Ostrava, 17. listopadu 15/2172, 708 33 Ostrava (Czech Republic); Nowak, B.; Winter, F. [Institute of Chemical Engineering, Vienna University of Technology, Getreidemarkt 9/166, A-1060 Vienna (Austria)

    2013-11-15

    Highlights: • MSW fly ash was thermally and hydrometallurgically treated to remove heavy metals. • More than 90% of easy volatile heavy metals (Cd and Pb) were removed thermally. • More than 90% of Cd, Cr, Cu an Zn were removed by alkaline – acid leaching. • The best results were obtained for the solution of 3 M NaOH and 2 M H{sub 2}SO{sub 4}. - Abstract: Heavy metals in fly ash from municipal solid waste incinerators are present in high concentrations. Therefore fly ash must be treated as a hazardous material. On the other hand, it may be a potential source of heavy metals. Zinc, lead, cadmium, and copper can be relatively easily removed during the thermal treatment of fly ash, e.g. in the form of chlorides. In return, wet extraction methods could provide promising results for these elements including chromium and nickel. The aim of this study was to investigate and compare thermal and hydrometallurgical treatment of municipal solid waste fly ash. Thermal treatment of fly ash was performed in a rotary reactor at temperatures between 950 and 1050 °C and in a muffle oven at temperatures from 500 to 1200 °C. The removal more than 90% was reached by easy volatile heavy metals such as cadmium and lead and also by copper, however at higher temperature in the muffle oven. The alkaline (sodium hydroxide) and acid (sulphuric acid) leaching of the fly ash was carried out while the influence of temperature, time, concentration, and liquid/solid ratio were investigated. The combination of alkaline-acidic leaching enhanced the removal of, namely, zinc, chromium and nickel.

  18. System for automatically preventing the raising of ash from dedicated landfills

    Directory of Open Access Journals (Sweden)

    Milutinović Predrag

    2012-01-01

    Full Text Available The paper presents a system for automatic prevention of raising of ashes from dedicated landfills based on a simple mathematical model which has modest entry requirements for meteorological data. Such an approach is efficient enough and enables fast information retrieval, i.e. zones with different concentrations of dust in the air, enabling quick start of counter measures to reduce emissions of ashes into the air. The system hardware consists of an automatic weather station, set of meters that determine moisture of ash, set of remotely managed sprinklers, computers, microprocessor and microcontroller based elements for the local acquisition and management of the executive elements and modules for wireless data transfer. An original software application for the system management has been developed. Within the application there is a module that allows entering of all data necessary to configure the system, as well as data about sensors and sprinklers. Based on the meteorological input data, measured moisture content of the ashes, and on the basis of determined functional dependencies, special software module operates sprinklers for soaking the surfaces from which the ashes is emitted into the air, in order to eliminate these emissions. The system, based on the developed mathematical model, predicts the propagation of ashes through the air, as well as dry and wet deposition, in real-time. The system automatically stores all the data relevant to the future analyses and reporting. The system is designed and implemented as modular and open. A custom developed graphical user interface serves as Man-Machine Interface (MMI. By using the TCP/IP connection it could be easily connected with the other information systems. [Projekat Ministarstva nauke Republike Srbije, br. TR-15005: Design and development of pilot system for preventing automatic raise of ashes from dedicated dumps

  19. The microstructure of self-healed PVA ECC under wet and dry cycles

    Directory of Open Access Journals (Sweden)

    Jia Huan Yu

    2010-06-01

    Full Text Available Self-healing of ECC (Engineered Cementitious Composites subjected to cyclic wetting and drying regimes is investigated in this paper. ECC structures subjected to outdoor environmental conditions such as wind and rain runoff can be simulated by accelerated test method of wetting and drying cycles. Uniaxial tensile tests of ECC M45 and ECC 2.8FA specimen are conducted respectively. It is found that crack width of ECC 2.8FA is around 10 μm with increased amount of fly ash, while the crack width of ECC M45 is around 100 μm. New insights about the microstructure and chemical composition analysis of ECC specimens initially cracked to 2% strain and then self-healed under wet-dry cycles are presented.

  20. Squeezing wetting and nonwetting liquids.

    Science.gov (United States)

    Samoilov, V N; Persson, B N J

    2004-01-22

    We present molecular-dynamics results for the squeezing of octane (C8H18) between two approaching solid elastic walls with different wetting properties. The interaction energy between the octane bead units and the solid walls is varied from a very small value (1 meV), corresponding to a nonwetting surface with a very large contact angle (nearly 180 degrees), to a high value (18.6 meV) corresponding to complete wetting. When at least one of the solid walls is wetted by octane we observe well defined molecular layers develop in the lubricant film when the thickness of the film is of the order of a few atomic diameters. An external squeezing-pressure induces discontinuous, thermally activated changes in the number n of lubricant layers (n-->n-1 layering transitions). With increasing interaction energy between the octane bead units and the solid walls, the transitions from n to n-1 layers occur at higher average pressure. This results from the increasing activation barrier to nucleate the squeeze-out with increasing lubricant-wall binding energy (per unit surface area) in the contact zone. Thus, strongly wetting lubricant fluids are better boundary lubricants than the less wetting ones, and this should result in less wear. We analyze in detail the effect of capillary bridge formation (in the wetting case) and droplets formation (in the nonwetting case) on the forces exerted by the lubricant on the walls. For the latter case small liquid droplets may be trapped at the interface, resulting in a repulsive force between the walls during squeezing, until the solid walls come into direct contact, where the wall-wall interaction may be initially attractive. This effect is made use of in some practical applications, and we give one illustration involving conditioners for hair care application. PMID:15268334

  1. Wet flue gas desulfurization processes

    Directory of Open Access Journals (Sweden)

    Hayrunnisa Çavuşoğlu

    2013-04-01

    Full Text Available The wet flue gas desulfurization process is widely used for the treatment of exhaust gases in power stations. Due to its high level of effectiveness over the already available processes, it has also been the mostly preferred method by industry. Its high SO2 removal efficiency, wide applicability of absorption chemicals and the ease of the chemical process handling which does not require comprehensive konowledge are among the main advantages of this process. In this article, various wet flue gas desulfurization processes such as lime/limestone have beendiscussed.

  2. The Ashes of Marci Shore

    Directory of Open Access Journals (Sweden)

    Zbigniew Kopeć

    2013-01-01

    Full Text Available The article discusses Marci Shore’s social and historical thought, as presented in her books: Caviar and Ashes: A Warsaw Generation’s Life and Death in Marxism, 1918-1968 (2006, The Taste of Ashes (2013, and her essays recently published in Polish translation. The author follows the American historian, presenting her concept of modernity, but focuses on the main theme of her research: the contribution of Jewish writers, poets, artists, and intellectuals to the creation of Marxism. The author acknowledges the great value of Marci Shore’s writings, but argues that her panorama of the 20th century would be fuller if her discussion included a reflection on the religious attitude of many Jewish thinkers to Marxism and the USSR. This topic was discussed by Nikolai Berdyaev and Polish thinkers who published in pre-war social journals.

  3. Ultrasonic ash/pyrite liberation

    Energy Technology Data Exchange (ETDEWEB)

    Yungman, B.A.; Buban, K.S.; Stotts, W.F.

    1990-06-01

    The objective of this project was to develop a coal preparation concept which employed ultrasonics to precondition coal prior to conventional or advanced physical beneficiation processes such that ash and pyrite separation were enhanced with improved combustible recovery. Research activities involved a series of experiments that subjected three different test coals, Illinois No. 6, Pittsburgh No. 8, and Upper Freeport, ground to three different size fractions (28 mesh [times] 0, 200 mesh [times] 0, and 325 mesh [times] 0), to a fixed (20 kHz) frequency ultrasonic signal prior to processing by conventional and microbubble flotation. The samples were also processed by conventional and microbubble flotation without ultrasonic pretreatment to establish baseline conditions. Product ash, sulfur and combustible recovery data were determined for both beneficiation processes.

  4. Packing channels with hydroinsulating ash pitchings

    Energy Technology Data Exchange (ETDEWEB)

    Nowakowa, J.

    1982-01-01

    The paper evaluates utilizatiion of fly ash from fossil-fuel power plants for production of panels used as pitching of channels and other water constructions. Two ash types were used: from the Konin plant fired with brown coal and from the Elblag plant fired with black coal. Three panel types were evaluated: fly ash from brown coal and 5% waterglass; fly ash from black coal, 6% waste products from sulfur filtration and 10% waterglass; ash from black coal, 6% carbide residue and 10% waterglass. Physical properties of three panel types such as filtration properties, compression strength, water influence and selected chemical properties (toxicity caused by the presence of activating compounds) were analyzed. Grass growth rate on ash panel pitching was observed 12 months long under laboratory conditions. Investigations show that grass growth rate was higher when brown coal ash was used. Water filtration improved grass vegetation in comparison to grass growth on dry ash panels only influenced by atmospheric precipitations. Grass roots did not penetrate ash pitching but formed a protective cover on panel surface. Use of channel pitching made of fly ash, waterglass and activating reagents is recommended. (13 refs.)

  5. Rapid toxicity screening of gasification ashes.

    Science.gov (United States)

    Zhen, Xu; Rong, Le; Ng, Wei Cheng; Ong, Cynthia; Baeg, Gyeong Hun; Zhang, Wenlin; Lee, Si Ni; Li, Sam Fong Yau; Dai, Yanjun; Tong, Yen Wah; Neoh, Koon Gee; Wang, Chi-Hwa

    2016-04-01

    The solid residues including bottom ashes and fly ashes produced by waste gasification technology could be reused as secondary raw materials. However, the applications and utilizations of these ashes are very often restricted by their toxicity. Therefore, toxicity screening of ash is the primary condition for reusing the ash. In this manuscript, we establish a standard for rapid screening of gasification ashes on the basis of in vitro and in vivo testing, and henceforth guide the proper disposal of the ashes. We used three different test models comprising human cell lines (liver and lung cells), Drosophila melanogaster and Daphnia magna to examine the toxicity of six different types of ashes. For each ash, different leachate concentrations were used to examine the toxicity, with C0 being the original extracted leachate concentration, while C/C0 being subsequent diluted concentrations. The IC50 for each leachate was also quantified for use as an index to classify toxicity levels. The results demonstrated that the toxicity evaluation of different types of ashes using different models is consistent with each other. As the different models show consistent qualitative results, we chose one or two of the models (liver cells or lung cells models) as the standard for rapid toxicity screening of gasification ashes. We may classify the gasification ashes into three categories according to the IC50, 24h value on liver cells or lung cells models, namely "toxic level I" (IC50, 24h>C/C0=0.5), "toxic level II" (C/C0=0.05types of ashes generated in gasification plants every day. Subsequently, appropriate disposal methods can be recommended for each toxicity category. PMID:26923299

  6. Ash and heavy metals in fluidized-bed combustion of wood wastes; Tuhka ja raskasmetallit puuperaeisen jaetteen kerrosleijupoltossa

    Energy Technology Data Exchange (ETDEWEB)

    Kaessi, T.; Aittoniemi, P. [IVO Power Engineering, Vantaa (Finland); Kauppinen, E.; Latva-Somppi, J.; Kurkela, J. [VTT Chemical Technology, Espoo (Finland); Partanen, J. [IVO Technology Centre, Vantaa (Finland)

    1997-10-01

    Ash formation and deposition mechanisms during co-combustion of pulp mill sludge and bark in industrial bubbling fluidized bed (BFB) combustor have been studied. Similar fuels were used in a bench-scale BFB for co-combustion of sludge and bark pellets and comparative studies with separate combustion of these fuels. Results indicated that in industrial scale unit significant fraction of ash had vaporization. About 14 mass-% of the total fly ash was found in the particle size below 0.2 {mu}m. The vaporized species consisted of potassium (K), sulfur (S), chlorine (Cl) and also of minor quantities of sodium (Na). In the benchscale similar vaporization fractions during co-combustion were measured, about 11 mass-%. During the combustion of bark this ratio, about 20 mass-%, was higher than during sludge combustion. The vaporized ash fraction was in the case of dried sludge combustion about 7 mass-%, but with wet sludge the vaporization rate was remarkably lower, about 1-2 mass-%. An increase in the bed temperature increased also ash vaporization. Test run period without combustion at elevated temperatures produced very low quantities of vaporized ash. The vaporized species in bench-scale test during bark pellet combustion were K, S and Cl, for sludge combustion also Na was clearly detected. No condensation of the vaporized species in bed area or furnace walls was observed. Bed defluidization was studied in the bench-scale unit. During bark pellet combustion the bed-agglomeration proceeded via small ash particle, below 2 {mu}m, coating on sand particle surface and consequent bonding between the ash layers. In the case of sludge combustion the accumulation of large ash particles and sintering of these porous agglomerates was observed to cause bed coarsening and defluidization. (orig.)

  7. FPLUME-1.0: An integral volcanic plume model accounting for ash aggregation

    Science.gov (United States)

    Folch, A.; Costa, A.; Macedonio, G.

    2016-02-01

    Eruption source parameters (ESP) characterizing volcanic eruption plumes are crucial inputs for atmospheric tephra dispersal models, used for hazard assessment and risk mitigation. We present FPLUME-1.0, a steady-state 1-D (one-dimensional) cross-section-averaged eruption column model based on the buoyant plume theory (BPT). The model accounts for plume bending by wind, entrainment of ambient moisture, effects of water phase changes, particle fallout and re-entrainment, a new parameterization for the air entrainment coefficients and a model for wet aggregation of ash particles in the presence of liquid water or ice. In the occurrence of wet aggregation, the model predicts an effective grain size distribution depleted in fines with respect to that erupted at the vent. Given a wind profile, the model can be used to determine the column height from the eruption mass flow rate or vice versa. The ultimate goal is to improve ash cloud dispersal forecasts by better constraining the ESP (column height, eruption rate and vertical distribution of mass) and the effective particle grain size distribution resulting from eventual wet aggregation within the plume. As test cases we apply the model to the eruptive phase-B of the 4 April 1982 El Chichón volcano eruption (México) and the 6 May 2010 Eyjafjallajökull eruption phase (Iceland). The modular structure of the code facilitates the implementation in the future code versions of more quantitative ash aggregation parameterization as further observations and experiment data will be available for better constraining ash aggregation processes.

  8. Volcanic ash infrared signature: porous non-spherical ash particle shapes compared to homogeneous spherical ash particles

    OpenAIRE

    A. Kylling; M. Kahnert; Lindqvist, H; Nousiainen, T.

    2014-01-01

    The reverse absorption technique is often used to detect volcanic ash clouds from thermal infrared satellite measurements. From these measurements effective particle radius and mass loading may be estimated using radiative transfer modelling. The radiative transfer modelling usually assumes that the ash particles are spherical. We calculated thermal infrared optical properties of highly irregular and porous ash particles and compared these with mass- and volume-equivalent sp...

  9. Can vegetative ash be water repellent?

    Science.gov (United States)

    Bodí, M. B.; Cerdà, A.; Mataix-Solera, J.; Doerr, S. H.

    2012-04-01

    In most of the literature, ash is referred to as a highly wettable material (e.g. Cerdà and Doerr, 2008; Etiegni and Campbell, 1991; Woods and Balfour 2010). However, the contrary was suggested in few articles, albeit with no further quantification (Gabet and Sternberg, 2008; Khanna et al., 1996; Stark, 1977). To clarify this question, water repellency measurements on ash using the Water Drop Penetration Times (WDPT) method were performed on ash from Mediterranean ecosystems and it was found to be water repellent (Bodí et al. 2011). Water repellency on ash from different wildfires ranged from 40 to 10 % occurrence with samples being extreme repellent (lasting more than 3600 s to penetrate). Part of the ash produced in the laboratory was also water repellent. After that, other ash samples had been found water repellent in wildfires in Colorado (unpublished results), Portugal (Gonzalez-Pelayo, 2009), or in prescribed fires in Australia (Bodí et al. 2011b; Petter Nyman, personnal communication). All the samples exhibiting water repellent properties had in common that were combusted at low temperatures, yielding in general ash with dark colour and contents of organic carbon of more than 18 % (Bodí et al. 2011a), although these properties were not exactly proportional to its water repellency occurrence or persistence. In addition, the species studied in Bodí et al. (2011) had been found to produce different levels of WR repellency, being ash from Pinus halepensis more repellent than that from Quercus coccifera and Rosmarins officinalis. Ash from Eucaliptus radiata had been found also very water repellent, as Pinus halepensis (unpublished data). The reasons of the existance of water repellent ash are that the charred residue produced by fire (an also contained in the ash) can contain aromatic compounds that have a lower free energy than water and therefore behave as hydrophobic materials with reduced solubility (Almendros et al., 1992 and Knicker, 2007

  10. Proefproject aandachtstoffen Wet milieugevaarlijke stoffen

    OpenAIRE

    Poel P van der; Ros JPM

    1988-01-01

    Dit rapport behandelt de uitvoering van het proefproject aandachtstoffen en geeft aanbevelingen aan het DGM voor vervolgonderzoek. De aandachtstoffenlijst wordt krachtens art. 22 Wet milieugevaarlijke stoffen vastgesteld en minstens eenmaal per jaar herzien, terwijl regelmatig onderzoek uitgevoerd moet worden naar stoffen die op deze lijst voorkomen. Voor het beschreven proefproject werden schriftelijke enquetes uitgevoerd voor vertegenwoordigers uit de categorieen kleurstoffen (trypan blue),...

  11. Inhibiting Wet Oxidation of Ammonia

    Science.gov (United States)

    Onisko, D. B. L.

    1985-01-01

    Simple modification of wet-oxidation process for treating organicwaste reduces loss of fixed nitrogen, potentially valuable byproduct of process. Addition of sufficient sulfuric acid to maintain reaction pH below 3 greatly reduces oxidation of ammonia to free nitrogen. No equipment modification required.

  12. Does Surface Roughness Amplify Wetting?

    Czech Academy of Sciences Publication Activity Database

    Malijevský, Alexandr

    2014-01-01

    Roč. 141, č. 18 (2014), s. 184703. ISSN 0021-9606 R&D Projects: GA ČR GA13-09914S Institutional support: RVO:67985858 Keywords : density functional theory * wetting * roughness Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.952, year: 2014

  13. Possibilities of utilizing power plant fly ashes

    Directory of Open Access Journals (Sweden)

    Mezencevová Andrea

    2003-09-01

    Full Text Available The burning of fossil fuels in industrial power stations plays a significant role in the production of thermal and electrical energy. Modern thermal power plants are producing large amounts of solid waste, mainly fly ashes. The disposal of power plant waste is a large environmental problem at the present time. In this paper, possibilities of utilization of power plant fly ashes in industry, especially in civil engineering, are presented. The fly ash is a heterogeneous material with various physical, chemical and mineralogical properties, depending on the mineralogical composition of burned coal and on the used combustion technology. The utilization of fly ashes is determined of their properties. The fineness, specific surface area, particle shape, density, hardness, freeze-thaw resistance, etc. are decisive. The building trade is a branch of industry, which employs fly ash in large quantities for several decades.The best utilization of fluid fly ashes is mainly in the production of cement and concrete, due to the excellent pozzolanic and cementitious properties of this waste. In the concrete processing, the fly ash is utilized as a replacement of the fine aggregate (fine filler or a partial replacement for cement (active admixture. In addition to economic and ecological benefits, the use of fly ash in concrete improves its workability and durability, increases compressive and flexural strength, reduces segregation, bleeding, shrinkage, heat evolution and permeability and enhances sulfate resistance of concrete.The aim of current research is to search for new technologies for the fly ash utilization. The very interesting are biotechnological methods to recovery useful components of fly ashes and unconventional methods of modification of fly ash properties such as hydrothermal zeolitization and mechanochemical modification of its properties. Mechanochemistry deals with physico - chemical transformations and chemical reactions of solids induced by

  14. Composites Based on Fly Ash and Clay

    International Nuclear Information System (INIS)

    Fly ash is a waste generated from the coal combustion during the production of electricity in the thermal power plants. It presents industrial by-product containing Technologically Enhanced Natural Occurring Radioactive Materials (TENORM) with the great potential for valorisation. Fly ash is successfully utilized in cement and concrete industry, also in ceramics industry as component for manufacturing bricks and tiles, and recently there are many investigations for production of glass-ceramics from fly ash. Although the utilization of fly ash in construction and civil engineering is dominant, the development of new alternative application for its further exploitation into new products is needed. This work presents the possibility for fly ash utilization for fabricating dense composites based on clay and fly ash with the potential to be used in construction industry

  15. Effect of fly ash on autogenous shrinkage

    Energy Technology Data Exchange (ETDEWEB)

    Pipat Termkhajornkit; Toyoharu Nawa; Masashi Nakai; Toshiki Saito [Hokkaido University, Hokkaido (Japan). Division of Structural and Geotechnical Engineering, Graduate School of Engineering

    2005-03-01

    The correlation between autogenous shrinkage and degree of hydration of fly ash was determined with the selective dissolution method. Then, the relationship between the degree of hydration of fly ash and autogenous shrinkage was examined. The results showed that the degree of hydration of fly ash increased as its Blaine surface area increased. The degree of hydration of fly ash increased with time, and autogenous shrinkage increased corresponding to the increase in the degree of hydration of fly ash. Moreover, it was found that the total quantity of Al{sub 2}O{sub 3} in cement-fly ash samples affected autogenous shrinkage at early ages, but the long-term influence was very small.

  16. COAL ASH RESOURCES RESEARCH CONSORTIUM

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    The Coal Ash Resources Research Consortium (CARRC, pronounced �cars�) is the core coal combustion by-product (CCB) research group at the Energy & Environmental Research Center (EERC). CARRC focuses on performing fundamental and applied scientific and engineering research emphasizing the environmentally safe, economical use of CCBs. CARRC member organizations, which include utilities and marketers, are key to developing industry-driven research in the area of CCB utilization and ensuring its successful application. CARRC continued the partnership of industry partners, university researchers, and the U.S. Department of Energy (DOE) addressing needs in the CCB industry through technical research and development projects. Technology transfer also continued through distribution and presentation of the results of research activities to appropriate audiences, with emphasis on reaching government agency representatives and end users of CCBs. CARRC partners have evolved technically and have jointly developed an understanding of the layers of social, regulatory, legal, and competition issues that impact the success of CCB utilization as applies to the CCB industry in general and to individual companies. Many CARRC tasks are designed to provide information on CCB performance including environmental performance, engineering performance, favorable economics, and improved life cycle of products and projects. CARRC activities from 1993�1998 included a variety of research tasks, with primary work performed in laboratory tasks developed to answer specific questions or evaluate important fundamental properties of CCBs. The tasks summarized in this report are 1) The Demonstration of CCB Use in Small Construction Projects, 2) Application of CCSEM (computer-controlled scanning electron microscopy) for Coal Combustion By-Product Characterization, 3) Development of a Procedure to Determine Heat of Hydration for Coal Combustion By-Products, 4) Investigation of the Behavior of High

  17. Remediation of ash problems in fluidised-bed combustors

    Energy Technology Data Exchange (ETDEWEB)

    Vuthaluru, H.B.; Zhang, D.K. [Curtin University of Technology, Perth, WA (Australia). School of Chemical Engineering

    2001-03-01

    The paper reports the control methods for mitigating particle agglomeration and bed defluidisation during fluidised-bed combustion of low-rank coals. A laboratory scale spouted-bed combustion system is used to study the effectiveness of several control methods including the use of alternative bed materials, mineral additives, pretreatment of coal and coal blending. Sillimanite, bauxite, calcite and magnesite were used as alternative bed materials whereas mineral additives viz. clay, kaosil and bauxite were injected into the combustion system while burning South Australian low-rank coal at 800{degree}C. Samples of the same coal subjected to water-washing, Al pretreatment and Ca pretreatment are also tested in the spouted-bed combustor. In addition, experiments were conducted with several coal blends prepared at ratios of 50:50 and 90:10 from two lignites and one sub-bituminous coal. Experiments showed that all the control methods are effective to different extends in reducing ash problems and resulted in extended combustion operation. Tests with alternative bed materials and mineral additives showed trouble free-operation for longer periods (7-12 h at 800{degree}C) than with sand runs at the same bed temperature. Wet pretreatment and coal blending were also found to be effective and resulted in extended combustion operation (9-12 h at 800{degree}C). Chemical analyses indicated that formation of low temperature eutectics was suppressed by Al/Ca/Mg-rich phases in ash coating of bed particles. This was identified as the main mechanism for prevention of ash problems observed with the use of alternative bed materials, mineral additives, pretreated coals and coal blends. 23 refs., 9 figs., 7 tabs.

  18. Evaluation of rice husk ash as filler in tread compounds

    International Nuclear Information System (INIS)

    Rice which is one of the largest agriculture crops produces around 22% of rice rusk during its milling process. This material is mainly used as fuel for energy generation, which results in an ash, which disposal represents an environmental issue. The rice husk ash (RHA) contains over than 70% of silica in an amorphous form and a lot of applications is being developed for it all over the world. The use of silica as a filler in the tire industry is growing since it contributes significantly to the reduction of fuel consumption of the automobiles, allowing at the same time better traction (safety). This paper presents an evaluation of the use of RHA as filler in rubber tread compounds prepared in lab scale and compares its performance with compounds prepared with commercial silica and carbon black, the fillers normally used in tire industry. Mechanical and rheological properties are evaluated, with emphasis for tan delta as an indicator of tread performance related with rolling resistance (fuel consumption) and wet grip/traction (safety)

  19. Evaluation of rice husk ash as filler in tread compounds

    Science.gov (United States)

    Fernandes, M. R. S.; Furtado, C. R. G.; de Sousa, A. M. F.

    2014-05-01

    Rice which is one of the largest agriculture crops produces around 22% of rice rusk during its milling process. This material is mainly used as fuel for energy generation, which results in an ash, which disposal represents an environmental issue. The rice husk ash (RHA) contains over than 70% of silica in an amorphous form and a lot of applications is being developed for it all over the world. The use of silica as a filler in the tire industry is growing since it contributes significantly to the reduction of fuel consumption of the automobiles, allowing at the same time better traction (safety). This paper presents an evaluation of the use of RHA as filler in rubber tread compounds prepared in lab scale and compares its performance with compounds prepared with commercial silica and carbon black, the fillers normally used in tire industry. Mechanical and rheological properties are evaluated, with emphasis for tan delta as an indicator of tread performance related with rolling resistance (fuel consumption) and wet grip/traction (safety).

  20. Evaluation of rice husk ash as filler in tread compounds

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, M. R. S., E-mail: monica.fernandes@lanxess.com [Lanxess Elastômeros do Brasil S.A., Brasil and Instituto de Química, Universidade do Estado do Rio de Janeiro (UERJ) (Brazil); Furtado, C. R. G., E-mail: russi@globo.com, E-mail: ana.furtado.sousa@gmail.com; Sousa, A. M. F. de, E-mail: russi@globo.com, E-mail: ana.furtado.sousa@gmail.com [Instituto de Química, Universidade do Estado do Rio de Janeiro (UERJ) (Brazil)

    2014-05-15

    Rice which is one of the largest agriculture crops produces around 22% of rice rusk during its milling process. This material is mainly used as fuel for energy generation, which results in an ash, which disposal represents an environmental issue. The rice husk ash (RHA) contains over than 70% of silica in an amorphous form and a lot of applications is being developed for it all over the world. The use of silica as a filler in the tire industry is growing since it contributes significantly to the reduction of fuel consumption of the automobiles, allowing at the same time better traction (safety). This paper presents an evaluation of the use of RHA as filler in rubber tread compounds prepared in lab scale and compares its performance with compounds prepared with commercial silica and carbon black, the fillers normally used in tire industry. Mechanical and rheological properties are evaluated, with emphasis for tan delta as an indicator of tread performance related with rolling resistance (fuel consumption) and wet grip/traction (safety)

  1. The Ash-1, Ash-2 and Trithorax Genes of Drosophila Melanogaster Are Functionally Related

    OpenAIRE

    Shearn, A.

    1989-01-01

    Mutations in the ash-1 and ash-2 genes of Drosophila melanogaster cause a wide variety of homeotic transformations that are similar to the transformations caused by mutations in the trithorax gene. Based on this similar variety of transformations, it was hypothesized that these genes are members of a functionally related set. Three genetic tests were employed here to evaluate that hypothesis. The first test was to examine interactions of ash-1, ash-2 and trithorax mutations with each other. D...

  2. Hazards Associated With Recent Popocatepetl Ash Emissions

    Science.gov (United States)

    Nieto, A.; Martin, A.; Espinasa-Pereña, R.; Ferres, D.

    2013-05-01

    Popocatepetl has been producing ash from small eruptions since 1994. Until 2012 about 650 small ash emissions have been recorded at the monitoring system of Popocatépetl Volcano. Ash consists mainly of glassy lithic clasts from the recent crater domes, plagioclase and pyroxene crystals, and in major eruptions, olivine and/or hornblende. Dome forming eruptions produced a fine white ash which covers the coarser ash. This fine ash consists of plagioclase, glass and cristobalite particles mostly under15 microns. During the recent crisis at Popocatépetl, April and May2012 ash fell on villages to the east and west of the volcano, reaching Mexico City (more than 20 million people) and Puebla (2 million people). In 14 cases the plumes had heights over 2 km, the largest on May 2 and 11 (3 and 4 km in height, respectively). Heavier ash fall occurred on April 13, 14, 20, and 23 and May 2, 3, 5, 11, 14, 23, 24 and 25. A database for ash fall was constructed from April 13 with field observations, reports emitted by the Centro Nacional de Comunicaciones (CENACOM), ash fall advisories received at CENAPRED and alerts from the Servicios a la Navegación en el Espacio Aéreo Mexicano (SENEAM). This aim of this database is to calculate areas affected by the ash and estimate the ash fall volume emitted by Popocatépetl in each of these events. Heavy ash fall from the May 8 to May 11 combined with reduced visibility due to fog forced to closure of the Puebla airport during various periods of time, for up to 13 hours. Domestic and international flights were cancelled. Ash eruptions have caused respiratory conditions in the state of Puebla, to the east of the volcano, since 1994 (Rojas et al, 2001), but because of the changing wind conditions in the summer mainly, some of these ash plumes go westward to towns in the State of Mexico and even Mexico City. Preliminary analyses of these eruptions indicate that some ash emissions produced increased respiratory noninfectious problems

  3. Characteristics of Wood ASH/OPC Concrete

    OpenAIRE

    Abdullahi, M

    2006-01-01

    The study presents the behaviour of wood ash / OPC concrete. Chemical analysis of wood ash, bulk density, sieve analysis and specific gravity of wood ash and aggregates, consistency, setting time and slump test of the fresh paste were conducted to determine the suitability of the materials for concrete making. Mix ratio of 1:2:4 and percentage replacement level of 0, 10, 20, 30 and 40 percents of cement by wood ash were used. 150mm´150mm cubes were cast, cured and crushed at 28 and 60 days to...

  4. Pre-treatment and recirculation of wood ashes; Forbehandling og recirkulering af flisaske

    Energy Technology Data Exchange (ETDEWEB)

    Skov, S.; Ingerslev, M.

    2011-07-01

    can to some extent be counteracted by hardening and pre-treating the ash before spreading in the forest. In this project, several hardening techniques were examined and tested. The results show that the connection between different hardening techniques and the results concerning solubility and reactivity, are not easily established and that simple techniques such as self-hardening may be as god as much more sophisticated pelletizing techniques. Experiments were carried out in a Norway spruce stand, where different ash types and doses were included. The results show that ash application affects the chemical composition of the O-horizon, while it has had a limited impact on the mineral soil, and that it is only the upper part of the mineral soil which may be affected. The experiments in the forest stand show that increased dosage led to larger changes of the chemical soil conditions and that these effects reach deeper in the soil and include the upper mineral soil. Ash application has generally not affected the concentration of N, P, Ca, Mg, Na, Cl, Al and Mn in the soil water notably, while the concentration of K and SO{sub 4} was increased by all treatments except bottom ash. Experiments were carried out in a Christmas tree stand to examine if a mixture of ash, manure and ammonium nitrate and limestone applied in two of a ten year rotation period could provide the trees with sufficient fertilizer effect to obtain god quality Christmas trees. The experiments showed some of the same chemical trends as were observe in the forest stand. However, the dosages used in the Christmas tree stand were much smaller and thereby also the effect. The treatments only have very limited effects on the soil chemistry. The effects are limited to the O-horizon and the upper 10 cm of the mineral soil. The project also included examination of different spreading technique and machinery. The conclusion of this work was that wet ash can be spread evenly and precisely dosed with modern disc

  5. Triboelectrostatic separation of unburned carbon from fly ash for ash recycling

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Keun; Kim, Seong Chan; Son, Nag Won; Kim, Doo Hyun; Oh, Jung Geun [Pusan National University, Pusan (Korea, Republic of)

    1997-09-30

    Fly ash from a coal-fired power plant is produced approximately 3 million tons in 1996 and causes the serious environmental problem due to the disposal in the ash pond. Fly ash is an accepted additive in concrete where it adds strength, sulfate resistance and reduced cost, provided acceptable levels of unburned carbon are maintained. This paper describes to investigate the technical feasibility of a dry triboelectrostatic process to separate unburned carbon from fly ash into economically valuable products. Particles of unburned carbon and fly ash can be imparted positive and negative surface charges, respectively, with a copper tribocharger due to differences in the work function values of the particles and the tribocharger, and can be separated by passing them through an external electric field. A laboratory scale separation system consists of a screw feeder for ash supply, a tribocharger, vertical collecting copper plates, power supplies, a flow meter, and a fan. Separation tests taking into account separation efficiency and ash recovery showed that fly ash recovery was strongly dependent on the tribocharger geometry, electric field strength, fly ash size, and ash feeding rate. Optimal separation conditions were fly ash size less than 125 {mu}m and electric field strength of 200 kV/m. Over 80% of the fly ash with 7% loss on ignition was recovered at carbon contents less than 3%. (author). 6 refs., 2 tabs., 9 figs.

  6. Volume reduction of lake sediment and decrease of its cesium content in decontamination process by wet oxidation method

    International Nuclear Information System (INIS)

    Wet oxidation method was applied aiming to decrease cesium contents in lake sediment. In this research, “reactive oxygen water”, that is prepared from hypochlorous acid by contact with metal ceramics, was reacted with three kinds of samples, that is, lake sediment, mixture of lake sediment and fallen leaves, and incineration ash of fallen leaves. Experimental results revealed that sample volume was reduced by means of wet oxidation of organic components in samples and that a large amount of cesium contents were transferred from sample to water phase. (author)

  7. Characterization of fly ash from bio and municipal waste

    DEFF Research Database (Denmark)

    Lima, Ana T.; Ottosen, Lisbeth M.; Pedersen, Anne Juul;

    2008-01-01

    the co-combustion of wood and oil. The focus is laid on differences in ash characteristics and on the mobility of Cd and Cr. These two heavy metals are chosen because Cd is the problematic heavy metal in bio ashes and Cr is problematic in many ash stabilization methods (in the Cr(VI) state). Based on...... leaching characteristics, Cd is found mainly associated with carbonates in MSW fly ash and is associated with oxides in straw and co-combustion of wood and oil ash, while Cr is mainly associated with oxides in all studied fly ashes or with carbonates in straw ash. Among the studied parameters, crystalline......Four different fly ashes are characterized in the present paper. The ashes differ in the original fuel type and were sampled at distinct plants. The investigation includes two different ashes from municipal solid waste incineration (with and without sorbents addition), a straw ash and an ash from...

  8. Emergency protection approved for two Ash Meadows fishes

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A large residential and agricultural development near Ash Meadows, Nevada poses an imminent threat to the survival of the Ash Meadows Amargosa pupfish and the Ash...

  9. Forest fuel, ashes and ecology

    International Nuclear Information System (INIS)

    Large-scale use of bioenergy is an essential measure if several of the major environmental problems are to be solved. However, it is important to utilize the possibilities available to produce biofuel without creating new environmental problems. Whole-tree removal gives a considerable reduction in the nitrogen lead which, in combination with the return of ashes, counteracts the nutrient imbalance and acidification in southern Sweden. Forestry of that kind should lead to lower total leaching of nitrogen in comparison with conventional forestry. In situations where there is high deposition of atmospheric sulphur and nitrogen, fuel removal with return of a moderate dose of slowly dissolvable ashes should be a good soil management measure. The humus status and flora/fauna always require some kind of consideration. With compensation measures and retained nutrient status there should be no problems with the humus status on most soils. However, on poor and dry soils, it is suitable to avoid whole-tree removal on account of the humus status. Consideration to nature includes, for example, increasing the number of broad-leaf trees, old trees and dead wood (preferably the trunks). These measures concern all types of forestry and are not linked directly with fuel removal. Removal of felling residues and return of ashes are of minor importance in comparison with this and fit well into forestry adapted to natural values. With correct planning and accomplishment of the removal of forest fuel the natural values of the forest can be retained or even improved. Forestry where fuel is also produced can be designed whereby negative effects are avoided at the same time as positive environmental effects are obtained. 68 refs, 5 figs, 3 tabs

  10. Characteristics of spanish fly ashes

    Directory of Open Access Journals (Sweden)

    de Luxán, M. P.

    1988-03-01

    Full Text Available The purpose of this study is the characterization of fly ashes produced by Spanish thermoelectric power plants, according to sampling taken in 1981 and 1982. The study takes in the following characteristics: physical characteristics (size distribution of particles, ...; chemical ones (chemical analysis...; and mineralogical ones (application of instrumental techniques of X-ray diffraction and infrared absorption spectroscopy. From a general point of view, it can be said that the samples of Spanish fly ashes are similar to those produced in other countries. The results obtained are a contribution to the knowledge of Spanish fly ashes and form part of the antecedents of investigations carried out in subsequent years.

    Este trabajo tiene por objeto la caracterización de las cenizas volantes producidas en las Centrales Termoeléctricas españolas, según un muestreo realizado entre 1981 y 1982. El estudio comprende las siguientes características: físicas (distribución del tamaño de partículas,...; químicas (análisis químico, …; y mineralógicas (aplicación de las técnicas instrumentales de difracción de rayos X y espectroscopía de absorción infrarroja. Desde un punto de vista general, se puede afirmar que las muestras de ceniza volante estudiadas son semejantes a las producidas en otros países. Los resultados obtenidos son una aportación al conocimiento de las cenizas volantes españolas y forman parte de los antecedentes de las investigaciones llevadas a cabo en años posteriores.

  11. Changes of the ash structure

    Science.gov (United States)

    Peer, Václav; Friedel, Pavel; Janša, Jan

    2016-06-01

    The aim of the article is to appraisal of the changes in the structure of the ash due to the addition of compounds capable of the eutectics composition change. For the transformation were used limestone and dolomite dosed in amounts of 2, 5 and 10 wt.% with pellets of spruce wood, willow wood and refused derived fuel. Combustion temperatures of the mixtures were adjusted according to the temperatures reached during the using of fuels in power plants, i.e. 900, 1000, 1100 and 1200 °C.

  12. WET SOLIDS FLOW ENHANCEMENT; FINAL

    International Nuclear Information System (INIS)

    The yield locus, tensile strength and fracture mechanisms of wet granular materials were studied. The yield locus of a wet material was shifted to the left of that of the dry specimen by a constant value equal to the compressive isostatic stress due to pendular bridges. for materials with straight yield loci, the shift was computed from the uniaxial tensile strength, either measured in a tensile strength tester or calculated from the correlation, and the angle of internal friction of the material. The predicted shift in the yield loci due to different moisture contents compare well with the measured shift in the yield loci of glass beads, crushed limestone, super D catalyst and Leslie coal. Measurement of the void fraction during the shear testing was critical to obtain the correct tensile strength theoretically or experimentally

  13. Review of Wet Gas Compressor Performance

    OpenAIRE

    Rofiqi, Zaenuddin Ar

    2014-01-01

    Subsea wet gas compression without preliminary separation give an opportunity to develop mature and remote gas/condensate field. Predicting wet gas compressor performance is important to develop those fields. Currently there is no standard exist for wet gas compression performance calculation (Hundseid et al., 2008). The current standards (ISO 5389:2005) exist only for dry gas by utilizing Schultz method. In wet gas compression, fluid properties are changing as fluid being compressed. Schult...

  14. Wetting hysteresis induced by nanodefects.

    Science.gov (United States)

    Giacomello, Alberto; Schimmele, Lothar; Dietrich, Siegfried

    2016-01-19

    Wetting of actual surfaces involves diverse hysteretic phenomena stemming from ever-present imperfections. Here, we clarify the origin of wetting hysteresis for a liquid front advancing or receding across an isolated defect of nanometric size. Various kinds of chemical and topographical nanodefects, which represent salient features of actual heterogeneous surfaces, are investigated. The most probable wetting path across surface heterogeneities is identified by combining, within an innovative approach, microscopic classical density functional theory and the string method devised for the study of rare events. The computed rugged free-energy landscape demonstrates that hysteresis emerges as a consequence of metastable pinning of the liquid front at the defects; the barriers for thermally activated defect crossing, the pinning force, and hysteresis are quantified and related to the geometry and chemistry of the defects allowing for the occurrence of nanoscopic effects. The main result of our calculations is that even weak nanoscale defects, which are difficult to characterize in generic microfluidic experiments, can be the source of a plethora of hysteretical phenomena, including the pinning of nanobubbles. PMID:26721395

  15. Erosion corrosion in wet steam

    International Nuclear Information System (INIS)

    The effect of different remedies against erosion corrosion in wet steam has been studied in Barsebaeck 1. Accessible steam systems were inspected in 1984, 1985 and 1986. The effect of hydrogen peroxide injection of the transport of corrosion products in the condensate and feed water systems has also been followed through chemical analyses. The most important results of the project are: - Low alloy chromium steels with a chromium content of 1-2% have shown excellent resistance to erosion corrosion in wet steam. - A thermally sprayed coating has shown good resistance to erosion corrosion in wet steam. In a few areas with restricted accessibility minor attacks have been found. A thermally sprayed aluminium oxide coating has given poor results. - Large areas in the moisture separator/reheater and in steam extraction no. 3 have been passivated by injection of 20 ppb hydrogen peroxide to the high pressure steam. In other inspected systems no significant effect was found. Measurements of the wall thickness in steam extraction no. 3 showed a reduced rate of attack. - The injection of 20 ppb hydrogen peroxide has not resulted in any significant reduction of the iron level result is contrary to that of earlier tests. An increase to 40 ppb resulted in a slight decrease of the iron level. - None of the feared disadvantages with hydrogen peroxide injection has been observed. The chromium and cobalt levels did not increase during the injection. Neither did the lifetime of the precoat condensate filters decrease. (author)

  16. Wet water glass production plant

    Directory of Open Access Journals (Sweden)

    Stanković Mirjana S.

    2003-01-01

    Full Text Available The IGPC Engineering Department designed basic projects for a wet hydrate dissolution plant, using technology developed in the IGPC laboratories. Several projects were completed: technological, machine, electrical, automation. On the basis of these projects, a production plant of a capacity of 75,000 t/y was manufactured, at "Zeolite Mira", Mira (VE, Italy, in 1997. and 1998, increasing detergent zeolite production, from 50,000 to 100,000 t/y. Several goals were realized by designing a wet hydrate dissolution plant. The main goal was increasing the detergent zeolite production. The technological cycle of NaOH was closed, and no effluents emitted, and there is no pollution (except for the filter cake. The wet water glass production process is fully automatized, and the product has uniform quality. The production process can be controlled manually, which is necessary during start - up, and repairs. By installing additional process equipment (centrifugal pumps and heat exchangers technological bottlenecks were overcome, and by adjusting the operation of autoclaves, and water glass filters and also by optimizing the capacities of process equipment.

  17. Wet friction materials and lubricants

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Takayuki

    1988-02-01

    There are wet and dry friction materials used for friction clutches and friction brakes. Wet friction materials include sintered alloys and semimetallic substances. Paper friction materials which are the most common wet friction materials used in automobiles were studied for their performance and their relation to lubricants. All present paper friction materials are non-asbestos paper friction materials. The requirements for paper friction material performance are as follows: (1) The heat resistance and durability are so high that the material can stand sliding for a long time. (2) The friction curve is flat. (3) The mechanical strength, wear resistance, and resistance to oil pressure are high. (4) The coefficient of friction (particularly, of static friction) is very high. (5) Variations in the coefficient of friction with time are low. The friction characteristics and wear of paper friction materials are influenced by the lubricant used together with the paper friction materials. It is necessary to develop materials which are immune to the influence of the lubricant. (11 figs, 3 tabs, 21 refs)

  18. Surface Modification of Fly Ash for Active Catalysis

    OpenAIRE

    Deepti Jain; Renu Hada; Ashu Rani

    2013-01-01

    Fly ash based effective solid base catalyst (KF/Al2O3/fly ash473, KF/Al2O3/fly ash673, and KF/Al2O3/fly ash873) was synthesized by loading KF over chemically and thermally activated fly ash. The chemical activation was done by treating fly ash with aluminum nitrate via precipitation method followed by thermal activation at 650°C to increase the alumina content in fly ash. The increased alumina content was confirmed by SEM-EDX analysis. The alumina enriched fly ash was then loaded with KF (10...

  19. ENG 328 ASH Course Tutorial / eng328dotcom

    OpenAIRE

    anil3

    2015-01-01

    ENG 328 Entire Course (Ash) For more course tutorials visit www.eng328.com ENG 328 Week 1 DQ 1 What is Technical Writing (Ash) ENG 328 Week 1 DQ 2 Target Audience (Ash) ENG 328 Week 2 DQ 1 Collaborative Writing Process (Ash) ENG 328 Week 2 DQ 2 Design and Graphics (Ash) ENG 328 Week 3 DQ 1 Web Design and Readability (Ash) ENG 328 Week 3 DQ 2 Online Technical Documents (Ash) ENG 328 Week 4 DQ 1 Writing Instructions (Ash) ENG 328 Week 4 DQ 2 Writing Propo...

  20. ENG 328 ASH Material-eng328dotcom

    OpenAIRE

    Sandywilliam

    2015-01-01

    ENG 328 Entire Course (Ash) For more course tutorials visit www.eng328.com ENG 328 Week 1 DQ 1 What is Technical Writing (Ash) ENG 328 Week 1 DQ 2 Target Audience (Ash) ENG 328 Week 2 DQ 1 Collaborative Writing Process (Ash) ENG 328 Week 2 DQ 2 Design and Graphics (Ash) ENG 328 Week 3 DQ 1 Web Design and Readability (Ash) ENG 328 Week 3 DQ 2 Online Technical Documents (Ash) ENG 328 Week 4 DQ 1 Writing Instructions (Ash) ENG 328 Week 4 DQ 2 Writing Propo...

  1. CHARACTERIZATION AND COMPARISON OF TREATED AND UNTREATED RICH HUSH ASH & FLY ASH FOR METAL MATRIX COMPOSITES

    Directory of Open Access Journals (Sweden)

    Ravinder Pal Singh

    2011-10-01

    Full Text Available Rice Husk ash and fly ash are agricultural and coal wastes respectively. These are produced in abundance globally and poses risk to health as well as environment. Thus their effective, conducive and eco-friendly utilization has always been a challenge for scientific community. The fly ash has been used as reinforcement for improved mechanical properties of composites (1,3-5,9. Rice husk ash can also be used for similar applications as its composition is almost similar to that of fly ash. This paper mainly deals with identification ofcharacteristics of both the fly ash and rice husk ash using spectroscopic and microscopic analysis. SEM, XRD,XRF and FTIR spectroscopic methods were used for the characterization of treated and untreated ashes. The results were compared and it was observed that both ashes possesses nearly same chemical phases and otherfunctional groups thus proposing the use of rice husk ash as reinforcement like fly ash in Metal Matrix Composites (MMCs specifically for wear resistance applications.

  2. Assessment of Ash Pond Project effectiveness

    International Nuclear Information System (INIS)

    In April 1989 the US Department of Energy (DOE) completed the Ash Pond Isolation Project at the Weldon Spring Site Remedial Action Project (WSSRAP). This Interim Response Action (IRA) was designed to reduce uranium concentrations in surface water released from the Ash Pond Outfall at the Weldon Spring Site (WSS). Uranium concentrations at this outfall have been measured as high as 5,500 pCi/l with an average concentration of 1,498 pCi/l. This project was one of several IRAs aimed at improving health and safety conditions at the WSS prior to the Record of Decision. The Ash Pond Isolation Project was constructed to intercept surface water runoff to the Ash Pond drainage and redirect flows around the Ash Pond and South Dump areas, thereby eliminating leaching and transport of uranium-contaminated materials from these source areas. The DOE has monitored the releases from the Ash Pond Outfall in fulfillment of the site's National Pollutant Discharge Elimination System Permit and initiated additional monitoring to further assess the effectiveness of the Ash Pond Isolation Project. Results of this monitoring effort indicate a reduction in uranium concentrations measured at the Ash Pond Outfall from a pre-completion average of 1,498 pCi/l to an average of 145 pCi/l following completion of the IRA. 6 refs., 6 figs., 3 tabs

  3. Adhesion Strength of Biomass Ash Deposits

    DEFF Research Database (Denmark)

    Laxminarayan, Yashasvi; Jensen, Peter Arendt; Wu, Hao;

    2015-01-01

    This study investigates the shear adhesion strength of biomass ash deposits on superheater tubes. Artificial biomass ash deposits were prepared on superheater tubes and sintered in an oven at temperatures up to 1000°C. Subsequently, the deposits were sheared off with the help of an electrically...

  4. Leaching kinetics of bottom ash waste as a source of calcium ions.

    Science.gov (United States)

    Koech, Lawrence; Everson, Ray; Neomagus, Hein; Rutto, Hilary

    2015-02-01

    Bottom ash is a waste material from coal-fired power plants, and it is known to contain elements that are potentially toxic at high concentration levels when disposed in landfills. This study investigates the use of bottom ash as a partial substitute sorbent for wet flue gas desulfurization (FGD) processes by focusing on its leaching kinetics in adipic acid. This was studied basing on the shrinking core model that was applied to the experimental data obtained by the authors presented at the International Conference on Industrial, Manufacturing, Automation and Mechanical Engineering, Johannesburg, South Africa, November 27-28, 2013) on dissolution of bottom ash. The leaching rate constant was obtained from different reaction variables, namely, temperature, pH, acid concentration, and solid-to-liquid ratio, that could affect the leaching process. The solid sample of bottom ash was characterized at different leaching periods using X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was found that solid-to-liquid ratio had a significant effect on the leaching rate constant when compared with other variables. The leaching kinetics showed that diffusion through the product layer was the rate-controlling step during leaching, and the activation energy for the process was found to be 18.92 kJ/mol. PMID:25947048

  5. Construction procedures using self hardening fly ash

    Science.gov (United States)

    Thornton, S. I.; Parker, D. G.

    1980-07-01

    Fly ash produced in Arkansas from burning Wyoming low sulfur coal is self-hardening and can be effective as a soil stabilizing agent for clays and sands. The strength of soil-self hardening fly ash develops rapidly when compacted immediately after mixing. Seven day unconfined compressive strengths up to 1800 psi were obtained from 20% fly ash and 80% sand mixtures. A time delay between mixing the fly ash with the soil and compaction of the mixture reduced the strength. With two hours delay, over a third of the strength was lost and with four hours delay, the loss was over half. Gypsum and some commercial concrete retarders were effective in reducing the detrimental effect of delayed compaction. Adequate mixing of the soil and fly ash and rapid compaction of the mixtures were found to be important parameters in field construction of stabilized bases.

  6. FLEXURAL BEHAVIOUR OF ACTIVATED FLY ASH CONCRETE

    Directory of Open Access Journals (Sweden)

    SUNILAA GEORGE

    2011-10-01

    Full Text Available Cement concrete is the most widely used construction material in many infrastructure projects. The development and use of mineral admixture for cement replacement is growing in construction industry mainly due to the consideration of cost saving, energy saving, environmental production and conservation of resources. Present study is aimed at replacing cement in concrete with activated fly ash. The paper highlights the chemical activation of low calcium fly ash using CaO and Na2SiO3 in the ratio 1:8 for improving the pozzolanic properties of fly ash .The investigation deals with the flexural behavior of beams using chemically activated fly ash at various cement replacement levels of 10%, 20%, 30%, 40%, 50%, and 60% with water cement ratio 0.45.The results are compared with OPC and Activated Fly ash at the same replacement levels.

  7. Fly Ash Amendments Catalyze Soil Carbon Sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Amonette, James E.; Kim, Jungbae; Russell, Colleen K.; Palumbo, A. V.; Daniels, William L.

    2003-09-15

    We tested the effects of four alkaline fly ashes {Class C (sub-bituminous), Class F (bituminous), Class F [bituminous with flue-gas desulfurization (FGD) products], and Class F (lignitic)} on a reaction that simulates the enzyme-mediated formation of humic materials in soils. The presence of FGD products completely halted the reaction, and the bituminous ash showed no benefit over an ash-free control. The sub-bituminous and lignitic fly ashes, however, increased the amount of polymer formed by several-fold. The strong synergetic effect of these ashes when enzyme is present apparently arises from the combined effects of metal oxide co-oxidation (Fe and Mn oxides), alkaline pH, and physical stabilization of the enzyme (porous silica cenospheres).

  8. Investigation on Leaching Behaviour of Fly Ash and Bottom Ash Replacement in Self-Compacting Concrete

    Science.gov (United States)

    Kadir, Aeslina Abdul; Ikhmal Haqeem Hassan, Mohd; Bakri Abdullah, Mohd Mustafa Al

    2016-06-01

    Fly ash and bottom ash are some of the waste generated by coal-fired power plants, which contains large quantities of toxic and heavy metals. In recent years, many researchers have been interested in studying on the properties of self-compacting concrete incorporated with fly ash and bottom ash but there was very limited research from the combination of fly ash and bottom ash towards the environmental needs. Therefore, this research was focused on investigating the leachability of heavy metals of SCC incorporated with fly ash and bottom ash by using Toxicity Characteristic Leaching Procedure, Synthetic Precipitation Leaching Procedure and Static Leaching Test. The samples obtained from the coal-fired power plant located at Peninsula, Malaysia. In this study, the potential heavy metals leached out from SCC that is produced with fly ash as a replacement for Ordinary Portland Cement and bottom ash as a substitute for sand with the ratios from 10% to 30% respectively were designated and cast. There are eight heavy metals of concern such as As, Cr, Pb, Zn, Cu, Ni, Mn and Fe. The results indicated that most of the heavy metals leached below the permissible limits from the United States Environmental Protection Agency and World Health Organization limit for drinking water. As a conclusion, the minimum leaching of the heavy metals from the incorporation of fly ash and bottom ash in self-compacting concrete was found in 20% of fly ash and 20% of bottom ash replacement. The results also indicate that this incorporation could minimize the potential of environmental problems.

  9. Properties and Leachability of Self-Compacting Concrete Incorporated with Fly Ash and Bottom Ash

    Science.gov (United States)

    Kadir, Aeslina Abdul; Ikhmal Haqeem Hassan, Mohd; Jamaluddin, Norwati; Bakri Abdullah, Mohd Mustafa Al

    2016-06-01

    The process of combustion in coal-fired power plant generates ashes, namely fly ash and bottom ash. Besides, coal ash produced from coal combustion contains heavy metals within their compositions. These metals are toxic to the environment as well as to human health. Fortunately, treatment methods are available for these ashes, and the use of fly ash and bottom ash in the concrete mix is one of the few. Therefore, an experimental program was carried out to study the properties and determine the leachability of selfcompacting concrete incorporated with fly ash and bottom ash. For experimental study, self-compacting concrete was produced with fly ash as a replacement for Ordinary Portland Cement and bottom ash as a replacement for sand with the ratios of 10%, 20%, and 30% respectively. The fresh properties tests conducted were slump flow, t500, sieve segregation and J-ring. Meanwhile for the hardened properties, density, compressive strength and water absorption test were performed. The samples were then crushed to be extracted using Toxicity Characteristic Leaching Procedure and heavy metals content within the samples were identified accordingly using Atomic Absorption Spectrometry. The results demonstrated that both fresh and hardened properties were qualified to categorize as self-compacting concrete. Improvements in compressive strength were observed, and densities for all the samples were identified as a normal weight concrete with ranges between 2000 kg/m3 to 2600 kg/m3. Other than that, it was found that incorporation up to 30% of the ashes was safe as the leached heavy metals concentration did not exceed the regulatory levels, except for arsenic. In conclusion, this study will serve as a reference which suggests that fly ash and bottom ash are widely applicable in concrete technology, and its incorporation in self-compacting concrete constitutes a potential means of adding value to appropriate mix and design.

  10. Soluble iron inputs to the Southern Ocean through recent andesitic to rhyolitic volcanic ash eruptions from the Patagonian Andes

    Science.gov (United States)

    Simonella, L. E.; Palomeque, M. E.; Croot, P. L.; Stein, A.; Kupczewski, M.; Rosales, A.; Montes, M. L.; Colombo, F.; García, M. G.; Villarosa, G.; Gaiero, D. M.

    2015-08-01

    Patagonia, due to its geographic position and the dominance of westerly winds, is a key area that contributes to the supply of nutrients to the Southern Ocean, both through mineral dust and through the periodic deposits of volcanic ash. Here we evaluate the characteristics of Fe dissolved (into soluble and colloidal species) from volcanic ash for three recent southern Andes volcanic eruptions having contrasting features and chemical compositions. Contact between cloud waters (wet deposition) and end-members of andesitic (Hudson volcano) and rhyolitic (Chaitén volcano) materials was simulated. Results indicate higher Fe release and faster liberation rates in the andesitic material. Fe release during particle-seawater interaction (dry deposition) has higher rates in rhyolitic-type ashes. Rhyolitic ashes under acidic conditions release Fe in higher amounts and at a slower rate, while in those samples containing mostly glass shards, Fe release was lower and faster. The 2011 Puyehue eruption was observed by a dust monitoring station. Puyehue-type eruptions can contribute soluble Fe to the ocean via dry or wet deposition, nearly reaching the limit required for phytoplankton growth. In contrast, the input of Fe after processing by an acidic eruption plume could raise the amount of dissolved Fe in surface ocean waters several times, above the threshold required to initiate phytoplankton blooms. A single eruption like the Puyehue one represents more than half of the yearly Fe flux contributed by dust.

  11. Treatment of fly ash for use in concrete

    Science.gov (United States)

    Boxley, Chett; Akash, Akash; Zhao, Qiang

    2012-05-08

    A process for treating fly ash to render it highly usable as a concrete additive. A quantity of fly ash is obtained that contains carbon and which is considered unusable fly ash for concrete based upon foam index testing. The fly ash is mixed with an activator solution sufficient to initiate a geopolymerization reaction and for a geopolymerized fly ash. The geopolymerized fly ash is granulated. The geopolymerized fly ash is considered usable fly ash for concrete according to foam index testing. The geopolymerized fly ash may have a foam index less than 35% of the foam index of the untreated fly ash, and in some cases less than 10% of the foam index of the untreated fly ash. The activator solution may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof.

  12. Treatment of fly ash for use in concrete

    Science.gov (United States)

    Boxley, Chett; Akash, Akash; Zhao, Qiang

    2013-01-08

    A process for treating fly ash to render it highly usable as a concrete additive. A quantity of fly ash is obtained that contains carbon and which is considered unusable fly ash for concrete based upon foam index testing. The fly ash is mixed with an activator solution sufficient to initiate a geopolymerization reaction and for a geopolymerized fly ash. The geopolymerized fly ash is granulated. The geopolymerized fly ash is considered usable fly ash for concrete according to foam index testing. The geopolymerized fly ash may have a foam index less than 35% of the foam index of the untreated fly ash, and in some cases less than 10% of the foam index of the untreated fly ash. The activator solution may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof.

  13. Coal combustion by wet oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Bettinger, J.A.; Lamparter, R.A.; McDowell, D.C.

    1980-11-15

    The combustion of coal by wet oxidation was studied by the Center for Waste Management Programs, of Michigan Technological University. In wet oxidation a combustible material, such as coal, is reacted with oxygen in the presence of liquid water. The reaction is typically carried out in the range of 204/sup 0/C (400/sup 0/F) to 353/sup 0/C (650/sup 0/F) with sufficient pressure to maintain the water present in the liquid state, and provide the partial pressure of oxygen in the gas phase necessary to carry out the reaction. Experimental studies to explore the key reaction parameters of temperature, time, oxidant, catalyst, coal type, and mesh size were conducted by running batch tests in a one-gallon stirred autoclave. The factors exhibiting the greatest effect on the extent of reaction were temperature and residence time. The effect of temperature was studied from 204/sup 0/C (400/sup 0/F) to 260/sup 0/C (500/sup 0/F) with a residence time from 600 to 3600 seconds. From this data, the reaction activation energy of 2.7 x 10/sup 4/ calories per mole was determined for a high-volatile-A-Bituminous type coal. The reaction rate constant may be determined at any temperature from the activation energy using the Arrhenius equation. Additional data were generated on the effect of mesh size and different coal types. A sample of peat was also tested. Two catalysts were evaluated, and their effects on reaction rate presented in the report. In addition to the high temperature combustion, low temperature desulfurization is discussed. Desulfurization can improve low grade coal to be used in conventional combustion methods. It was found that 90% of the sulfur can be removed from the coal by wet oxidation with the carbon untouched. Further desulfurization studies are indicated.

  14. Precursor films in wetting phenomena

    OpenAIRE

    Popescu, M. N.; Oshanin, G.; Dietrich, S.; Cazabat, A. -M.

    2012-01-01

    The spontaneous spreading of non-volatile liquid droplets on solid substrates poses a classic problem in the context of wetting phenomena. It is well known that the spreading of a macroscopic droplet is in many cases accompanied by a thin film of macroscopic lateral extent, the so-called precursor film, which emanates from the three-phase contact line region and spreads ahead of the latter with a much higher speed. Such films have been usually associated with liquid-on-solid systems, but in t...

  15. Sensor-based control in eddy current separation of incinerator bottom ash.

    Science.gov (United States)

    Rahman, Md Abdur; Bakker, M C M

    2013-06-01

    A sensor unit was placed online in the particle stream produced by an eddy current separator (ECS) to investigate its functionality in non-ferrous metals recovery. The targeted feed was the 1-6mm size fraction bottom ash from a municipal waste incinerator. The sensor unit was attached to the ECS splitter, where it counted in real-time metal and mineral particles and accurately measured the grade of the stream in the metals product. Influence of segregation (e.g. due to particle size or density) on the metals concentrate were detected and studied using the sensor data collected at different splitter distances. Tests were performed in the laboratory and in a bottom ash processing plant with two different types of ECS and two sources of bottom ash with different moisture content. The measured metal grades matched the manual analyses with errors 0%, 1.5% and 3.1% for moist, dry and very wet feed, respectively. For very wet feed the ECS metals recovery dropped, which was observed from the strongly reduced particle counts and the large changes in cumulative particle properties. The measured sample proved representative for the whole metals concentrate if it is collected at a representative position within the metals particle trajectory fan produced by the ECS. ECS-performance proved sensitively dependent on splitter distance, since a 10mm shift may result in 10% change in metal recovery and 18% change in grade. The main functionalities of the sensor unit are determined as online quality control and facilitation of automatic control over the ECS splitter distance. These functionalities translate in significant improvements in ECS metals recovery which in turn is linked to economic benefits, increased recycling rate of scrap metals and a further reduction of the ecological drawbacks of incinerator bottom ash. PMID:23490354

  16. Optimization of CLSM mix proportion with combination of clinker ash and fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Horiguchi, T.; Okumura, H.; Saeki, N. [Hokkaido Univ., Sapporo (Japan)

    2001-07-01

    The disposal of clinker ash and fly ash in Japan is becoming an ecological problem which is being addressed by several research institutions in the country. This study evaluated the effective application of a wide range of off-specification fly ash plus non standard clinker ash in CLSM. CLSM is defined by the ACI Cement and Concrete Terminology as material that results in a compressive strength of 8275 kPa or less at the age of 28 days. In particular, this study examined the effect of mixture proportions on the short-term and long-term compressive strength of CLSM. The cement used in this study was portland cement whose physical and chemical properties were determined by the Japan Industrial Standard. Two different types of fly ash and three different types of clinker ash in different compositions were used. The major differences were in the specific gravity and water absorption capabilities. The various slurry mixtures were tested for flowability, bleeding, segregation and compressive strength and the test results were summarized. It was determined that slump flow varied from 140 to 200 mm. The mixtures satisfied the target value to ensure adequate flowability. Bleeding ratio varied from 1.5 to 6.7 per cent, which is significantly higher than that of ordinary flowable fills. Also, the density of CLSM varied from 1338 to 2056 kg per cubic metre, which is also much lighter than cement mortar, a significant advantage. This paper described the effect of fly ash quality on the compressive strength, the optimum clinker ash composition, and the strength development estimation. It was concluded that there is no significant disadvantage in using fly ash or clinker ash in CLSM. In fact, clinker ash reduces bleeding of CLSM. The optimum proportion of clinker substitution was found to be 50 per cent. The strength of CLSM with fly ash and clinker ash was found to increase significantly up to 91 days. 15 refs., 5 tabs., 9 figs.

  17. Determination of ash in animal feed: AOAC official method 942.05 revisited.

    Science.gov (United States)

    Thiex, Nancy; Novotny, Lawrence; Crawford, Andy

    2012-01-01

    AOAC Official Method 942.05, Ash in Animal Feed, has been applied in feed laboratories since its publication in the Official Methods of Analysis in 1942. It is a routine test with renewed interest due to the incorporation of "ash values" into modern equations for the estimation of energy content of dairy feed, beef feed, and pet food. As with other empirical methods, results obtained are a function of the test conditions. For this method, the critical conditions are the ignition time, ignition temperature, and any other furnace or weighing conditions. Complete ignition can be observed by the absence of black color (due to residual carbonaceous material) in the ash residue. To investigate performance of AOAC 942.05, 15 samples were chosen to be representative of a wide range of feed materials. These materials were tested at the conditions of AOAC 942.05 (ignition at 600 degrees C for 2 h) and similar or more rigorous conditions. The additional conditions investigated included: 600 degrees C for 4 h; 600 degrees C for 2 h, cool, and ignite 2 additional h; 600 degrees C for 2 h, cool, wet, dry, and ignite 2 additional h; 550 degrees C for 6 h; 550 degrees C for 3 h, cool, and ignite 3 additional h; and 550 degrees C for 3 h, cool, wet, dry, ignite 3 additional h. Results for all other conditions investigated were found to be significantly different from the current AOAC Method 942.05. All ignition conditions were significantly different from each other except two: 550 degrees C for 3 h, cool, ignite 3 additional h; and 550 degrees C for 3 h, cool, wet, dry, and ignite 3 additional h. Recommendations for modification to AOAC Official Method 942.05 are suggested based on statistical analysis of the data and a review of the literature. PMID:23175971

  18. Pozzolanic Reaction Kinetics of Coal Ashes

    Institute of Scientific and Technical Information of China (English)

    ZHENG Hongwei; WANG Zhijuan; QIAN Jueshi; SONG Yuanming; WANG Zhi

    2009-01-01

    The pozzolanic reactivity was determined by the hydration kinetics of pozzolanic reaction based on the fact that the hydration products of active SiO_2 and Al_2O_3 with lime were soluble in dilute hydrochloric acid.The results show that the pozzolanic reaction of active SiO_2 and Al2O3 of coal ashes follows apparent first-order kinetics.The reaction rate constant of FBC ashes is greater than that of PC ashes,while the activation energy of the former is lower than that of the latter.It is confirmed that the pozzolanic activity of fluidized bed combustion(FBC)ashes is significantly higher than that of PC ashes,and the reaction barrier of the former is lower than that of the latter,because the microstructures of FBC ashes,such as mineralogical composition,morphology and polymerization degree of [SiO_4]and[AlO_6]are more favorable to the pozzolanic activity development than those of PC ashes.

  19. Kohonen's feature maps for fly ash categorization.

    Science.gov (United States)

    Nataraja, M C; Jayaram, M A; Ravikumar, C N

    2006-12-01

    Fly ash is a common admixture used in concrete and may constitute up to 50% by weight of the total binder material. Incorporation of fly ash in Portland-cement concrete is highly desirable due to technological, economic, and environmental benefits. This article demonstrates the use of artificial intelligence neural networks for the classification of fly ashes in to different groups. Kohonen's Self Organizing Feature Maps is used for the purpose. As chemical composition of fly ash is crucial in the performance of concrete, eight chemical attributes of fly ashes have been considered. The application of simple Kohonen's one-dimensional feature maps permitted to differentiate three main groups of fly ashes. Three one-dimensional feature maps of topology 8-16, 8-24 and 8-32 were explored. The overall classification result of 8-16 topology was found to be significant and encouraging. The data pertaining to 80 fly ash samples were collected from standard published works. The categorization was found to be excellent and compares well with Canadian Standard Association's [CSA A 3000] classification scheme. PMID:17285691

  20. Development and testing of a wet oxidation waste processing system. [for waste treatment aboard manned spacecraft

    Science.gov (United States)

    Weitzmann, A. L.

    1977-01-01

    The wet oxidation process is considered as a potential treatment method for wastes aboard manned spacecraft for these reasons: (1) Fecal and urine wastes are processed to sterile water and CO2 gas. However, the water requires post-treatment to remove salts and odor; (2) the residual ash is negligible in quantity, sterile and easily collected; and (3) the product CO2 gas can be processed through a reduction step to aid in material balance if needed. Reaction of waste materials with oxygen at elevated temperature and pressure also produces some nitrous oxide, as well as trace amounts of a few other gases.

  1. Utilization of ashes as construction materials in landfills; Askanvaendning i deponier

    Energy Technology Data Exchange (ETDEWEB)

    Tham, Gustav [Telge AB, Soedertaelje (Sweden); Ifwer, Karin [AaF-Process AB, Stockholm (Sweden)

    2006-03-15

    Large amounts of material will be needed to cover landfill sites in Sweden and other EU states over the next ten years. It is estimated that more than one hundred million tons of material will be required in Sweden alone in order to comply with the EU Landfill Directive (1999/31/EC). Suitable natural materials to be used in landfill cover constructions are not available on site. This report summarises the present use of secondary construction material in waste management with a focus on incineration ash. Information from eleven landfill sites has been compiled and includes the practical experience of using ash as the primary material in landfill cover. Other applications of using ash on landfill sites are also discussed. According to Swedish law, a complete cover of a landfill site consists of five different layers, each having its own specific function. The permeability of the total cover should then satisfy the permeability requirements of 50 litres per square meter and year for non-hazardous waste landfill sites and 5 litres per square meter and year for those with hazardous waste. The main purpose of this report is to describe how ash is used in the different layers and discuss the advantages or disadvantages of the techniques applied. Various landfill sites have submitted information ranging from small test areas on a pilot scale to full scale application of techniques on several hectares. Each project is part of the general Vaermeforsk research program for 2003-2005, Environmentally proper use of ash. The overall results show that incineration ash is a suitable material for use in liner constructions, either alone, or mixed with sewage sludge. Data from water percolating below the liner has indicated that the liners can meet permeability requirements. Special techniques for applying the various layers have been described. It is important to have materials readily available for an area, in order to avoid long period of exposure to dry or wet weather. Some

  2. Expansion control for cementation of incinerated ash

    International Nuclear Information System (INIS)

    A method, in which incinerated ash is solidified with a cement material, has been developed to dispose of radioactive incinerated ash waste. A small amount of metallic Al, which was not oxidized in the incineration, existed in the ash. When such ash was mixed with a cement material and water, alkaline components in the ash and the cement were dissolved in the mixing water and then metallic Al reaction with the alkaline compounds resulted in generation of H2. Because the H2 generation began immediately just after the mixing, H2 bubbles pushed up the mixed grout material and an expanded solidified form was obtained. The expansion leads to lowering the strength of the solidified form and making harmful void. In this study, we tried to control H2 generation from the reaction of metallic Al in the cementation by means of following two methods, one was a method to let metallic Al react prior to the cementation and the other was a method to add an expansion inhibitor that made an oxide film on the surface of metallic Al. In the pre-treatment, the ash was soaked in water in order to let metallic Al react with it, and then the ash with the immersion solution was dried at 105 Celsius degrees. The pre-treated ash was mixed with an ordinary portland cement and water. The inhibitor of lithium nitrite, sodium nitrite, phosphoric acid, or potassium dihydrogen phosphate was added at the mixing process. The solidified forms prepared using the pre-treated ash and lithium nitrite were not expanded. Phosphoric acid and sodium nitrite were effective for expansion control, but potassium dihydrogen phosphate did not work. (authors)

  3. Elucidating the mysteries of wetting.

    Energy Technology Data Exchange (ETDEWEB)

    Webb, Edmund Blackburn, III (,; ); Bourdon, Christopher Jay; Grillet, Anne Mary; Sackinger, Philip A.; Grest, Gary Stephen; Emerson, John Allen; Ash, Benjamin Jesse; Heine, David R.; Brooks, Carlton, F.; Gorby, Allen D.

    2005-11-01

    Nearly every manufacturing and many technologies central to Sandia's business involve physical processes controlled by interfacial wetting. Interfacial forces, e.g. conjoining/disjoining pressure, electrostatics, and capillary condensation, are ubiquitous and can surpass and even dominate bulk inertial or viscous effects on a continuum level. Moreover, the statics and dynamics of three-phase contact lines exhibit a wide range of complex behavior, such as contact angle hysteresis due to surface roughness, surface reaction, or compositional heterogeneities. These thermodynamically and kinetically driven interactions are essential to the development of new materials and processes. A detailed understanding was developed for the factors controlling wettability in multicomponent systems from computational modeling tools, and experimental diagnostics for systems, and processes dominated by interfacial effects. Wettability probed by dynamic advancing and receding contact angle measurements, ellipsometry, and direct determination of the capillary and disjoining forces. Molecular scale experiments determined the relationships between the fundamental interactions between molecular species and with the substrate. Atomistic simulations studied the equilibrium concentration profiles near the solid and vapor interfaces and tested the basic assumptions used in the continuum approaches. These simulations provide guidance in developing constitutive equations, which more accurately take into account the effects of surface induced phase separation and concentration gradients near the three-phase contact line. The development of these accurate models for dynamic multicomponent wetting allows improvement in science based engineering of manufacturing processes previously developed through costly trial and error by varying material formulation and geometry modification.

  4. Commercial Demonstration of the Manufactured Aggregate Processing Technology Utilizing Spray Dryer Ash

    Energy Technology Data Exchange (ETDEWEB)

    Roy Scandrol

    2004-11-01

    This quarterly report covers the period from July 1st, 2004 through September 30th, 2004. It covers: technical development, permitting status, engineering status, construction status, operations summary and marketing support activities for this period. Plant startup, including equipment and system debugging, is underway. Minor adjustments to the SDA feed system, pug mill, and extruder were completed. Testing of admixtures to prevent the wetted SDA from sticking is continuing. The power plant is implementing a lime optimization program to reduce the calcium hydroxide values in the ash.

  5. Volcanic Ash Transport and Dispersion Forecasting

    Science.gov (United States)

    Servranckx, R.; Stunder, B.

    2006-12-01

    Volcanic ash transport and dispersion models (VATDM) have been used operationally since the mid 1990's by the International Civil Aviation Organization (ICAO) designated Volcanic Ash Advisory Centers (VAAC) to provide ash forecast guidance. Over the years, significant improvements in the detection and prediction of airborne volcanic ash have been realized thanks to improved models, increases in computing power, 24-hr real time monitoring by VAACs / Meteorological Watch Offices and close coordination with Volcano Observatories around the world. Yet, predicting accurately the spatial and temporal structures of airborne volcanic ash and the deposition at the earth's surface remains a difficult and challenging problem. The forecasting problem is influenced by 3 main components. The first one (ERUPTION SOURCE PARAMETERS) comprises all non-meteorological parameters that characterize a specific eruption or volcanic ash cloud. For example, the volume / mass of ash released in the atmosphere, the duration of the eruption, the altitude and distribution of the ash cloud, the particle size distribution, etc. The second component (METEOROLOGY) includes all meteorological parameters (wind, moisture, stability, etc.) that are calculated by Numerical Weather Prediction models and that serve as input to the VATDM. The third component (TRANSPORT AND DISPERSION) combines input from the other 2 components through the use of VATDM to transport and disperse airborne volcanic ash in the atmosphere as well as depositing it at the surface though various removal mechanisms. Any weakness in one of the components may adversely affect the accuracy of the forecast. In a real-time, operational response context such as exists at the VAACs, the rapid delivery of the modeling results puts some constraints on model resolution and computing time. Efforts are ongoing to evaluate the reliability of VATDM forecasts though the use of various methods, including ensemble techniques. Remote sensing data

  6. Column leaching from biomass combustion ashes

    DEFF Research Database (Denmark)

    Maresca, Alberto; Astrup, Thomas Fruergaard

    2015-01-01

    this study, a fly ash sample from an operating Danish power plant based on wood biomass was collected, chemically characterized and investigated for its leaching release of nutrients and heavy metals. A column leaching test was employed. The strongly alkaline pH of all the collected eluates suggested...... the potential suitability of the ash as a liming material. Although high contents of nutrients were detected, differences in their leaching release were found. Heavy metals were detected within typical literature contents for Nordic countries ashes....

  7. Heavy metals in MSW incineration fly ashes

    DEFF Research Database (Denmark)

    Ferreira, Celia; Ribeiro, Alexandra B.; Ottosen, Lisbeth M.

    2003-01-01

    characterized regarding its physical-chemical properties: pH, solubility, chemical composition, and leaching, amongst others. Results indicate a high alkalinity and the presence of large amounts of calcium, chlorides, sulfates, carbonates, sodium and potassium. Metal concentrations in fly ash are: 6,2 g/kg for...... zinc, 2,4 g/kg for lead, 1,7 g/kg for iron, and 7,9 g/kg for magnesium. Copper, manganese, chromium and cadmium are also present with 546, 338, 104 and 91 mg/kg of fly ash, respectively. These results are extremely important in subsequent studies on the treatment of fly ash....

  8. Electrodialytic removal of heavy metals from fly ashes

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul

    2002-01-01

    The aim of the Ph.D. work was to develop the electrodialytic remediation method for removal of heavy metals from fly ashes. The work was focused on two types of fly ashes: fly ashes from wood combustion and fly ashes from municipal solid waste incineration....

  9. Electrodialytic removal of Cd from biomass combustion fly ash suspensions.

    Science.gov (United States)

    Kirkelund, Gunvor M; Damoe, Anne J; Ottosen, Lisbeth M

    2013-04-15

    Due to relatively high concentrations of Cd, biomass combustion fly ashes often fail to meet Danish legislative requirements for recycling as fertilizer. In this study, the potential of using electrodialytic remediation for removal of Cd from four different biomass combustion fly ashes was investigated with the aim of enabling reuse of the ashes. The ashes originated from combustion of straw (two ashes), wood chips, and co-firing of wood pellets and fuel oil, respectively. A series of laboratory scale electrodialytic remediation experiments were conducted with each ash. The initial Cd concentration in the ashes varied between 8.8 mg Cd/kg (co-firing ash) and 64 mg Cd/kg (pre-washed straw ash), and pH varied from 3.7 (co-firing ash) to 13.3 (wood ash). In spite of such large variations between the ashes, the electrodialytic method showed to be sufficiently robust to treat the ashes so the final Cd concentration was below 2.0mg Cd/kg DM in at least one experiment done with each ash. This was obtained within 2 weeks of remediation and at liquid to solid (L/S) ratios of L/S 16 for the pre-washed straw ash and L/S 8 for the straw, co-firing and wood ash. PMID:23454460

  10. Substantial achievements and prospect in fly ash utilization of China

    Energy Technology Data Exchange (ETDEWEB)

    Li Heng; Zhou Bao-wei [China Fly Ash Tech Development Centre (China)

    1996-08-01

    In 1994, 91.14 million tons of fly ash (including boiler bottom ash) was produced in Chinese coal-fired power plants; but only 37 million tons were used. The utilization of fly ash in embankments, in concretes, as structural fill for civil engineering, in building materials, in agriculture, and fly ash resource recycling is discussed. 11 refs., 7 tabs.

  11. Fly Ash Disposal in Ash Ponds: A Threat to Ground Water Contamination

    Science.gov (United States)

    Singh, R. K.; Gupta, N. C.; Guha, B. K.

    2016-07-01

    Ground water contamination due to deposition of fly ash in ash ponds was assessed by simulating the disposal site conditions using batch leaching test with fly ash samples from three thermal power plants. The periodic analysis of leachates was performed for selected elements, Fe, Cu, Ni, Cr, Pb and Cd in three different extraction solutions to determine the maximum amount that can be leached from fly ash. It was observed that at low pH value, maximum metals are released from the surface of the ash into leachate. The average concentration of these elements found in ground water samples from the nearby area of ash ponds shows that almost all the metals except `Cr' are crossing the prescribed limits of drinking water. The concentration of these elements at this level can endanger public health and environment.

  12. Development of near infrared spectroscopy models for the quantitative prediction of the lignocellulosic components of wet Miscanthus samples.

    Science.gov (United States)

    Hayes, Daniel J M

    2012-09-01

    Miscanthus samples were scanned over the visible and near infrared wavelengths at several stages of processing (wet-chopped, air-dried, dried and ground, and dried and sieved). Models were developed to predict lignocellulosic and elemental constituents based on these spectra. The dry and sieved scans gave the most accurate models; however the wet-chopped models for glucose, xylose, and Klason lignin provided excellent accuracies with root mean square error of predictions of 1.27%, 0.54%, and 0.93%, respectively. These models can be suitable for most applications. The wet models for arabinose, Klason lignin, acid soluble lignin, ash, extractives, rhamnose, acid insoluble residue, and nitrogen tended to have lower R(2) values (0.80+) for the validation sets and the wet models for galactose, mannose, and acid insoluble ash were less accurate, only having value for rough sample screening. This research shows the potential for online analysis at biorefineries for the major lignocellulosic constituents of interest. PMID:22771552

  13. Effect of Fly Ash on the Electrical Conductivity of Concretes

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The fly ash occasionally has high content of iron oxide and carbon that are good electrical conducting components. This paper investigates the effect of the fly ash used as mineral admixtures on the electrical conductivity of concretes. The electrical properties of concretes using 3 kinds of fly ash with different iron oxide contents have been studied. Experimental results show that at the same fly ash dosage the resistivity of concrete using fly ash with high content of iron oxide is slightly lower than that with low content of iron oxide. However, the concrete resistivity after 14d increases as fly ash dosage increases regardless of iron oxide content in fly ash.

  14. Processing the right building materials with fly ash content

    Energy Technology Data Exchange (ETDEWEB)

    Oostendorp, F.E. [EZH (Netherlands)

    1997-12-31

    The use of power station ash and fly ash in construction in the Netherlands is described. Fly ash production by the industry is high, but practically all is used as a building material. The fly ash is used in producing cement, artificial gravel, as an asphalt filter, in concrete, and for special applications. Two processes are used to turn fly ash into artificial gravel. The LYTAG process mixes the ash with pulverized coal and water to form pellets, then ignites the pellets resulting in their sintering. The Aerdelite process mixes dry ash with lime, then blows steam through at 85{degree}C, resulting in a hardening reaction.

  15. Electrodialytic removal of Cd from biomass combustion fly ash

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Ottosen, Lisbeth M.; Simonsen, Peter;

    2004-01-01

    fly ashes was studied. Four fly ashes were investigated, originating from combustion of straw (two ashes), wood chips, and co-firing of wood pellets and fuel oil, respectively. One of the straw ashes had been pre-washed and was obtained suspended in water, the other ashes were obtained naturally dry......Due to a high concentration of Cd, biomass combustion fly ash often fails to meet the Danish legislative requirements for recycling on agricultural fields. In this work the potential of using the method Electrodialytic Remediation to reduce the concentration of Cd in different biomass combustion....... The initial Cd concentration in the ashes varied between 8.8 mg Cd/kg DM (co-firing ash) and 64 mg Cd/kg DM (pre-washed straw ash), and pH varied from 3.7 to 13.3. In spite of large differences in ash characteristics, the electrodialytic remediation experiments indicated a good remediation potential...

  16. Drop splashing is independent of substrate wetting

    CERN Document Server

    Latka, Andrzej; Nagel, Sidney R; de Pablo, Juan J

    2016-01-01

    A liquid drop impacting a dry solid surface with sufficient kinetic energy will splash, breaking apart into numerous secondary droplets. This phenomenon shows many similarities to forced wetting, including the entrainment of air at the contact line. Because of these similarities and the fact that forced wetting has been shown to depend on the wetting properties of the surface, existing theories predict splashing to depend on wetting properties as well. However, using high-speed interference imaging we observe that wetting properties have no effect on splashing for various liquid-surface combinations. Additionally, by fully resolving the Navier-Stokes equations at length and time scales inaccessible to experiments, we find that the shape and motion of the air-liquid interface at the contact line are independent of wettability. We use these findings to evaluate existing theories and to compare splashing with forced wetting.

  17. Ash Decline Assessment in Emerald Ash Borer Infested Natural Forests Using High Spatial Resolution Images

    Directory of Open Access Journals (Sweden)

    Justin Murfitt

    2016-03-01

    Full Text Available The invasive emerald ash borer (EAB, Agrilus planipennis Fairmaire infects and eventually kills endemic ash trees and is currently spreading across the Great Lakes region of North America. The need for early detection of EAB infestation is critical to managing the spread of this pest. Using WorldView-2 (WV2 imagery, the goal of this study was to establish a remote sensing-based method for mapping ash trees undergoing various infestation stages. Based on field data collected in Southeastern Ontario, Canada, an ash health score with an interval scale ranging from 0 to 10 was established and further related to multiple spectral indices. The WV2 image was segmented using multi-band watershed and multiresolution algorithms to identify individual tree crowns, with watershed achieving higher segmentation accuracy. Ash trees were classified using the random forest classifier, resulting in a user’s accuracy of 67.6% and a producer’s accuracy of 71.4% when watershed segmentation was utilized. The best ash health score-spectral index model was then applied to the ash tree crowns to map the ash health for the entire area. The ash health prediction map, with an overall accuracy of 70%, suggests that remote sensing has potential to provide a semi-automated and large-scale monitoring of EAB infestation.

  18. Municipal solid waste ash as a cement raw material substitute

    OpenAIRE

    Somnuk Tangtermsirikul; Pichaya Rachdawong; Kritsada Sisomphon

    2000-01-01

    An investigation of using municipal solid waste (MSW) ash as a cement raw material substitute was performed to evaluate the potential use of ash in construction. The use of incineratior ash in cement production would not only get rid of the ash, but also alleviate many environmental problems, for example, reducing raw materials required for cement production, reducing CO2 emission into the atmosphere, and reducing landfill space requirement for the residue ash disposal. The metallic oxide con...

  19. Electrodialytic removal of Cd from biomass combustion fly ash suspensions

    OpenAIRE

    Kirkelund, Gunvor M.; Ottosen, Lisbeth M.; Damoe, Anne J.

    2013-01-01

    Due to relatively high concentrations of Cd, biomass combustion fly ashes often fail to meet Danish legislative requirements for recycling as fertilizer. In this study, the potential of using electrodialytic remediation for removal of Cd from four different biomass combustion fly ashes was investigated with the aim of enabling reuse of the ashes. The ashes originated from combustion of straw (two ashes), wood chips, and co-firing of wood pellets and fuel oil, respectively. A series of laborat...

  20. Mechanisms of wet oxidation by hydrogen peroxide

    International Nuclear Information System (INIS)

    A research programme is currently under way at BNL and MEL to investigate the possible use of Hydrogen Peroxide with metal ion catalysts as a wet oxidation treatment system for CEGB organic radioactive wastes. The published literature relating to the kinetics and mechanism of oxidation and decomposition reactions of hydrogen peroxide is reviewed and the links with practical waste management by wet oxidation are examined. Alternative wet oxidation systems are described and the similarities to the CEGB research effort are noted. (author)

  1. Wetting on Lines and Lattices of Cylinders

    OpenAIRE

    Osborn, W. R.; Yeomans, J. M.

    1994-01-01

    This paper discusses wetting and capillary condensation transitions on a line and a rectangular array of cylinders using an interface potential formalism. For a line of cylinders, there is a capillary condensation transition followed by complete wetting if the cylinders are sufficiently close together. Both transitions disappear as the cylinder separation is increased. The dependence of the wetting phase diagram of a rectangular array of cylinders is discussed as a function of the chemical po...

  2. AshMeadowsSpeckledDace_CH

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify the areas where final critical habitat for the Ash Meadows Amargosa pupfish (Cyprinodon nevadensis mionectes) occur. "Nevada, Nye County: Each...

  3. ASH External Web Portal (External Portal)

    Data.gov (United States)

    Department of Transportation — The ASH External Web Portal is a web-based portal that provides single sign-on functionality, making the web portal a single location from which to be authenticated...

  4. NICKEL SPECIATION OF RESIDUAL OIL ASH

    Science.gov (United States)

    EPA GRANT NUMBER: R827649C002Title: Nickel Speciation Of Residual Oil AshInvestigators: Kevin C. Galbreath, John Won, Frank E. Huggins, Gerald P. Huffman, Christopher J. Zygarlicke, Donald L. TomanInstitution: University of North Dakota<...

  5. Heavy metals in MSW incineration fly ashes

    DEFF Research Database (Denmark)

    Ferreira, Celia; Ribeiro, Alexandra B.; Ottosen, Lisbeth M.

    2003-01-01

    characterized regarding its physical-chemical properties: pH, solubility, chemical composition, and leaching, amongst others. Results indicate a high alkalinity and the presence of large amounts of calcium, chlorides, sulfates, carbonates, sodium and potassium. Metal concentrations in fly ash are: 6,2 g/kg for......Incineration is a common solution for dealing with the increasing amount of municipal solid waste (MSW). During the process, the heavy metals initially present in the waste go through several transformations, ending up in combustion products, such as fly ash. This article deals with some issues...... related to the combustion of MSW and the formation of fly ash, especially in what concerns heavy metals. Treatment of the flue gas in air pollution control equipment plays an important role and the basic processes to accomplish this are explained. Fly ash from a semi-dry flue gas treatment system is...

  6. Radiation hygienic aspects of fly ash

    International Nuclear Information System (INIS)

    Starting from measuring values of radioactivity, toxicity, as well as from models of food chains, radionuclide migration and deposition, irradiation doses are calculated in case of release of fly ash to the environment (e.g. from building materials). (orig.)

  7. Volcanic Ash Advisory Database, 1983-2003

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Volcanic ash is a significant hazard to aviation and can also affect global climate patterns. To ensure safe navigation and monitor possible climatic impact, the...

  8. AshMeadowsAmargosaPupfish_CH

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify the areas where final critical habitat for the Ash Meadows Amargosa pupfish (Cyprinodon nevadensis mionectes) occur. "Nevada, Nye County: Each...

  9. Electrodialytic removal of heavy metals from different fly ashes. Influence of heavy metal speciation in the ashes

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Ottosen, Lisbeth M.; Villumsen, Arne

    2003-01-01

    Electrodialytic Remediation has recently been suggested as a potential method for removal of heavy metals from fly ashes. In this work electrodialytic remediation of three different fly ashes, i.e. two municipal solid waste incinerator (MSWI) fly ashes and one wood combustion fly ash was studied in......-moval efficiencies were observed, especially for Pb and Zn. Cd, the sole heavy metal of environmental concern in the wood ash, was found more tightly bonded in this ash than in the two MSWI ashes. It was suggested that complex Cd-silicates are likely phases in the wood ash whereas more soluble, condensed phases are...... lab scale, and the results were discussed in relation to the expected heavy metal speciation in the ashes. In initial leaching experiments the pH-dependent desorption characteristics of the heavy metals Cd, Pb, Zn and Cu were analogous in the two MSWI ashes, and thus it was expected that the...

  10. Electrodialytic removal of heavy metals from different fly ashes. Influence of heavy metal speciation in the ashes

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Ottosen, Lisbeth M.; Villumsen, Arne

    2003-01-01

    Electrodialytic Remediation has recently been suggested as a potential method for removal of heavy metals from fly ashes. In this work electrodialytic remediation of three different fly ashes, i.e. two municipal solid waste incinerator (MSWI) fly ashes and one wood combustion fly ash was studied in...... lab scale, and the results were discussed in relation to the expected heavy metal speciation in the ashes. In initial leaching experiments the pH-dependent desorption characteristics of the heavy metals Cd, Pb, Zn and Cu were analogous in the two MSWI ashes, and thus it was expected that the......-moval efficiencies were observed, especially for Pb and Zn. Cd, the sole heavy metal of environmental concern in the wood ash, was found more tightly bonded in this ash than in the two MSWI ashes. It was suggested that complex Cd-silicates are likely phases in the wood ash whereas more soluble, condensed phases are...

  11. Carbon nanotube fiber spun from wetted ribbon

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Yuntian T; Arendt, Paul; Zhang, Xiefei; Li, Qingwen; Fu, Lei; Zheng, Lianxi

    2014-04-29

    A fiber of carbon nanotubes was prepared by a wet-spinning method involving drawing carbon nanotubes away from a substantially aligned, supported array of carbon nanotubes to form a ribbon, wetting the ribbon with a liquid, and spinning a fiber from the wetted ribbon. The liquid can be a polymer solution and after forming the fiber, the polymer can be cured. The resulting fiber has a higher tensile strength and higher conductivity compared to dry-spun fibers and to wet-spun fibers prepared by other methods.

  12. A mesoscopic model for (de)wetting.

    Science.gov (United States)

    Merabia, S; Pagonabarraga, I

    2006-06-01

    We present a mesoscopic model for simulating the dynamics of a non-volatile liquid on a solid substrate. The wetting properties of the solid can be tuned from complete wetting to total non-wetting. This model opens the way to study the dynamics of drops and liquid thin films at mesoscopic length scales of the order of the nanometer. As particular applications, we analyze the kinetics of spreading of a liquid drop wetting a solid substrate and the dewetting of a liquid film on a hydrophobic substrate. In all these cases, very good agreement is found between simulations and theoretical predictions. PMID:16775662

  13. Biologic effects of oil fly ash.

    OpenAIRE

    Ghio, Andrew J.; Silbajoris, Robert; Carson, Johnny L.; Samet, James M.

    2002-01-01

    Epidemiologic studies have demonstrated increased human morbidity and mortality with elevations in the concentration of ambient air particulate matter (PM). Fugitive fly ash from the combustion of oil and residual fuel oil significantly contributes to the ambient air particle burden. Residual oil fly ash (ROFA) is remarkable in the capacity to provoke injury in experimental systems. The unique composition of this emission source particle makes it particularly useful as a surrogate for ambient...

  14. Composites based on fly ash and clay

    OpenAIRE

    Fidancevska, Emilija; Jovanov, Vojo; Angusheva, Biljana; Srebrenkoska, Vineta

    2014-01-01

    Fly ash is a waste generated from the coal combustion during the production of electricity in the thermal power plants. It presents industrial by-product containing Technologically Enhanced Natural Occurring Radioactive Materials (TENORM) with the great potential for valorisation (1). Fly ash is successfully utilized in cement and concrete industry (2), also in ceramics industry (3) as component for manufacturing bricks and tiles, and recently there are many investigations for production of g...

  15. Retrieval of ash properties from IASI measurements

    OpenAIRE

    Lucy J. Ventress; Grainger, Don; McGarragh, Gregory; Carboni, Elisa; Smith, Andrew J.

    2016-01-01

    A new optimal estimation algorithm for the retrieval of volcanic ash properties has been developed for use with hyperspectral satellite instruments such as the Infrared Atmospheric Sounding Interferometer (IASI). The retrieval method uses the wavenumber range 680–1200 cm−1, which contains window channels, the CO2 ν2 band (used for the height retrieval), and the O3 ν3 band. Assuming a single infinitely (geometrically) thin ash plume and combining this with...

  16. Ash composition of oils of West Kazakhstan

    Energy Technology Data Exchange (ETDEWEB)

    Bakirova, S.F.; Aleshin, G.N.; Kalinin, S.K.; Kotova, A.V.; Nadirov, N.K.

    1982-01-01

    Results are presented of studying the distribution of trace elements in oils of new fields of West Kazakhstan. It is indicated that for the majority of oils studied, the concentration of trace elements does not depend on the ash content of oils. For resinous asphaltenes and highly sulfur oils of the Buzachi region, there is an increase in the content of iron, vanadium, nickel with a rise in ash content of oils. This is possibly associated with their secondary enrichment with trace elements.

  17. Utilization of pulverized fuel ash in Malta

    International Nuclear Information System (INIS)

    In Malta all of the waste produced is mixed and deposited at various sites around the island. None of these sites were purpose built, and all of the waste is above groundwater level. The landfills are not engineered and do not contain any measures to collect leachate and gases emanating from the disposal sites. Another waste, which is disposed of in landfills, is pulverized fuel ash (PFA), which is a by-product of coal combustion by the power station. This has been disposed of in landfill, because its use has been precluded due to the radioactivity of the ashes. The aim of this study was to analyze the chemical composition of the pulverized fuel ash and to attempt to utilize it as a cement replacement in normal concrete mixes in the construction industry. The levels of radiation emitted from the ashes were measured by gamma spectrometry. The results of this study revealed that although at early ages cement replacement by PFA resulted in a reduction in compressive strength (P = 0), when compared to the reference concrete at later ages the strengths measured on concrete cores were comparable to the reference concrete (P > 0.05). The utilization of PFA up to 20% cement replacement in concrete did not raise the radioactivity of the concrete. In conclusion, utilization of PFA in the construction industry would be a better way of disposing of the ashes rather than controlling the leachate and any radioactivity emitted by the landfilled ashes

  18. Use of wood ash for road stabilisation

    International Nuclear Information System (INIS)

    Due to warmer winters in Sweden, the bearing capacity of forestry roads has become increasingly problematic in recent years. Road stabilization is needed in order to get timber out from the forests. This usually involves the addition of cement to the road body. However, wood ash is a possible substitute for cement because it has similar properties. Using wood ash has the added advantage of saving landfill space. This paper presented an ongoing laboratory study on leaching and mechanical stability, as well as frost-sensitivity using a 30 per cent ash addition to natural soils for reinforcing a forestry road near Timra in central Sweden. The road was being monitored with regard to environmental impact and mechanical properties. The paper discussed the potential of biofuel ashes and the increasing need to reinforce infrastructure due to climate change. The environmental impact from ash use in road constructions was then addressed. It was concluded that the application of ash in road construction would help to strengthen forest roads, make them more resistant to climatic change and render them accessible year-round. 32 refs., 3 tabs., 2 figs.

  19. Characterization of sintered coal fly ashes

    Energy Technology Data Exchange (ETDEWEB)

    M. Erol; S. Kucukbayrak; A. Ersoy-Mericboyu [Istanbul Technical University, Istanbul (Turkey). Department of Chemical Engineering, Chemical and Metallurgical Engineering Faculty

    2008-06-15

    Can, Catalagzi, Seyitomer and Afsin-Elbistan thermal power plant fly ashes were used to investigate the sintering behavior of fly ashes. For this purpose, coal fly ash samples were sintered to form ceramic materials without the addition of any inorganic additives or organic binders. In sample preparation, 1.5 g of fly ash was mixed in a mortar with water. Fly ash samples were uniaxially pressed at 40 MPa to achieve a reasonable strength. The powder compacts were sintered in air. X-ray diffraction analysis revealed that quartz (SiO{sub 2}), mullite (Al{sub 6}Si{sub 2}O{sub 13}), anorthite (CaAl{sub 2}Si{sub 2}O{sub 8}), gehlenite (Ca{sub 2}Al{sub 2}SiO{sub 7}) and wollastonite (CaSiO{sub 3}) phases occurred in the sintered samples. Scanning electron microscopy investigations were conducted on the sintered coal fly ash samples to investigate the microstructural evolution of the samples. Different crystalline structures were observed in the sintered samples. The sintered samples were obtained having high density, low water adsorption and porosity values. Higher Al{sub 2}O{sub 3} + SiO{sub 2} contents caused to better properties in the sintered materials. 19 refs., 5 figs., 4 tabs.

  20. Effects of a layer of vegetative ash layer on wettable and water repellent soil hydrology

    Science.gov (United States)

    Bodí, Merche B.; Doerr, Stefan H.; Cerdà, Artemi; Mataix-Solera, Jorge

    2010-05-01

    Following a wildfire, a layer of vegetative ash often covers the ground until it is dissolved or redistributed by wind and water erosion. Much of the existing literature suggests that the ash layer temporally reduces infiltration by clogging soil pores or by forming a surface crust (Mallik et al., 1984; Onda et al., 2008). However, an increasing number of field-based studies have found that, at least in the short term, ash increases infiltration by storing rainfall and protecting the underlying soil from sealing (Cerdà and Doerr, 2008; Woods and Balfour, 2008). On the other hand, after a fire the soil may have produced, enhanced or reduced its water repellency (Doerr et al., 2000). Very few studies have been taken into account the interaction of the ash and the repellent soil. The layer of ash may have similar role as a litter layer in delaying runoff and reducing erosion by storing water. In order to examine this interaction, it was been made a series of experiments using a laboratory rainfall simulation. It has been assessed the effects of an ash layer i) on a wettable and water repellent soil (WDPT > 7200s), ii) with different ash thicknesses (bare soil and 5 mm, 15 mm and 30 mm of ash), iii) preceding and following the first rain after a fire when the ground is still wetted and after being partially dried. Three replicates were done, being a total of 40 simulations. The ash used was collected from a Wildfire in Teruel (Spain) during summer of 2009. The simulations were conducted in metal boxes of 30x30 cm and filled with 3 cm of soil. The slope of the box was set at 10° (17%) and the intensity applied was 78-84 mm h-1during 40 minutes. The splash detachment was determined also using four splash cups. Overland flow and subsurface drainage was collected at 1-minute intervals and the former stored every 5 min to allow determination of sediment concentrations, yield and erosion rates. Each sample was examined at the end in terms of water repellency, infiltration

  1. Wildland fire ash: future research directions

    Science.gov (United States)

    Bodí, Merche B.; Martins, Deborah A.; Cerdà, Artemi; Balfour, Victoria N.; Santin, Cristina; Doerr, Stefan H.; Pereira, Paulo; Mataix-Solera, Jorge

    2014-05-01

    Ash is a key component of the forest fires affected land (Cerdà, 1998; Bodí et al., 2011; Pereira et al., 2013a). Ash controls the hydrological processes and determines the water repellency (Dlapa et al., 2012) and the infiltration rates (Cerdà and Doerr, 2008;). Moreover, ash is the key factor on runoff initiation and then on the soil erosion. Little is known about the impact of ash in different ecosystems, but during the last decade a substantial increase in the papers that show the role of ash in the Earth and Soil System were published (Bodí et al., 2012; Pereira et al., 2013b).. Ash is being found as the key component of the post-fire pedological, geomorphological and hydrological response after forest fires (Fernández et al., 2012; Martín et al., 2012; Bodí et al., 2013; Guénon et al., 2013; Pereira et al., 2013c). A recent State-of-the-Art review about wildland fire ash (Bodí et al., 2014) compiles the knowledge regarding the production, composition and eco-hydro-geomorphic effects of wildland fire ash. In the present paper we indicate the knowledge gaps detected and suggest topics that need more research effort concerning: i) data collection and analysis techniques: a) To develop standardized sampling techniques that allow cross comparison among sites and avoid inclusion of the underlying soil unless the burned surface soil forms part of the ash layer, b) To develop standardized methods to define and characterize ash, including its color, physical properties such as particle size distribution or density, proportion of pyrogenic C, chemical and biological reactivity and persistence in the environment, c) To validate, calibrate and test measurements collected through remote sensing with on-the-ground measurements. ii) ash production, deposition redistribution and fate: d) To untangle the significance of the effects of maximum temperature reached during combustion versus the duration of heating, e) To understand the production of ash by measuring its

  2. Leachability of trace metal elements from fly ashes, and from concrete incorporating fly ashes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, M.H. [National University of Singapore (Singapore); Blanchette, M.C. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Energy Technology Centre; Malhotra, V.M. [Natural Resources Canada, Ottawa, ON (Canada)

    2001-07-01

    Manufacturing portland cement is not environmentally desirable because for every tonne of cement produced, about one tonne of carbon dioxide is released into the atmosphere. This problem can be solved by replacing a portion of portland cement with fly ash, a mineral by-product of burning coal at power generation facilities. A study was conducted to examine the leachability of trace metal elements from a variety of fly ashes from various sources in Canada and the United States along with the concrete incorporating the fly ash. Gold, arsenic, boron, barium cadmium, chromium, copper, mercury, lead and selenium are the regulated elements in leachates. In this study, each of these elements were tested from 9 fly ashes within the limits of the U.S. Environmental Protection Agency and the Canadian regulations for the Transportation of Dangerous Goods. It was shown that in general, but with some exceptions, the leaching of arsenic, boron, nickel and selenium increased with an increase in their content in the fly ash. Arsenic concentration from fly ash obtained from bituminous coal was found to be much higher than that from lignite or from sub-bituminous coal. However, the study also showed that none of the trace metals in the leachates from the fly ash concrete samples exceeded the regulated concentration limits, regardless of the type and percentage of fly ash used. It was concluded that concrete which incorporates fly ash is environmentally stable. It was also concluded that waste product utilization, in terms of using fly ash from power generating facilities, can significantly reduce carbon dioxide emissions when manufacturing portland cement. Typical replacement levels of fly ash in portland cement concrete is about 20 per cent by mass of the total cementitious materials. 10 refs., 14 tabs., 4 figs.

  3. Vegetation type and the presence of ash as factors in the evolution of soil water repellency after a forest fire

    Directory of Open Access Journals (Sweden)

    P. Jiménez-Pinilla

    2013-05-01

    Full Text Available After wildfires, burning may induce the occurrence of soil water repellency. Soil water repellency may vary in space and time in function of vegetation, the presence of ash and soil moisture. This study analyzes the evolution of fire-induced soil water repellency in function of these factors, and proposes measures to promote the restoration of fire-affected soils. Burnt and unburnt (control soil plots under pine and shrub from a recently burned area (Gorga, Alicante, SE Spain were established. Three treatments were applied: in some of the plots, the original ash layer was kept on the ground; in a second group, the ash layer was removed for simulating the effects of erosion; finally, in a third group, percolating irrigation was conducted to simulate a possible good input of water into the soil profile after burning, that could occur if the first rains were with high quantity but low intensity. During the dry season, soil moisture content was significantly lower in burned plots due to fire-induced water repellency and reduced vegetation cover. During the wet season, soil moisture decreased in the control unburnt plots due to direct evaporation of water intercepted by vegetation and consumption by roots. Fire increased soil water repellency only in plots under pine. Water repellency decreased during the wet season, disappearing in January and reappearing after declining rainfalls. This baseline recovery of soil water repellency was lower where ash removal was simulated. In unburned plots, seasonal fluctuations were less important. In general, ash removal promotes a rapid reduction of water repellency, since it can induce washing of hydrophobic compounds. Irrigation performed immediately after the fire also contributed to decreased water repellency.

  4. Advanced characterisation of municipal solid waste ashes

    Energy Technology Data Exchange (ETDEWEB)

    Skytte Pedersen, Randi

    2002-12-15

    This report deals with characterisation of Municipal Solid Waste (MSW) ashes from the Danish power plant Maebjergvaerket, Holstebro. MSW has been used as a fuel since the mid 1960's and since then, the MSW incineration plants have experienced operational problems due to deposit formation and corrosion. Inorganic elements tightly or loosely bound in the waste are the main cause of these problems. The tightly bound elements will mainly stay on the grate during combustion, whereas the loosely bound elements are volatilised and recondensed elsewhere in the furnace. Many of the heavy metals form volatile chlorides during the incineration, and the fly ash fraction thus show enrichment in these elements. Presence of chlorides and heavy metals in deposits may cause severe corrosion due to formation of low-melting eutectics. Chlorine gas in the flue gas is also of major concern with respect to corrosion, due to formation of volatile chlorides when chlorine comes in contact with the tube material. Four different ash fractions (bottom ash, super heater ash, economiser ash and fly ash) taken from Maebjergvaerket have been analysed with respect to particle sizes, structures, shapes and composition. The applied methods were scanning electron microscopy (SEM), energy dispersive X-ray analyses (EDX) and mapping, which were used in order to determine sizes, chemical composition and structure of the particles. X-ray powder diffraction (XRD) was used to provide information about crystallography and mineral phases. Chemical analysis was also performed along with a particle size distribution for the fine-grained fractions (economiser and fly ash). The amount of silicates consisting of Ca, Al and Si, were found to decrease through the furnace, whereas the amount of alkali (Na, K) chlorides and heavy metals (Pb, Zn) increased. The bonding in the waste before incineration is the direct cause of this, since silicates are tightly bound and chlorides are loosely bound. There was a

  5. Sulphation characteristics of paper sludge ash

    Energy Technology Data Exchange (ETDEWEB)

    Roh, S.A. [Environmental Systems Research Center, Korea Inst. of Machinery and Materials, Daejeon (Korea, Republic of); Kim, S.D. [Environmental Systems Research Center, Korea Inst. of Machinery and Materials, Daejeon (Korea, Republic of). Dept. of Chemical and Biomolecular Engineering

    2007-04-15

    Landfills are no longer a viable solution for the disposal of sludge produced from waste water treatment plants because of the decrease in available space, rising fees and growing environmental concerns. However, thermal utilization of this waste may be an economic and sustainable disposal solution. Co-combustion of low heating value sludge with fossil fuels has a positive effect for sulfur dioxide (SO{sub 2}) emissions due to the low sulphur content of biomass fuels and increased sulphur retention in the ash. The sulphur retention is attributed to the formation of sulphates, such as CaSO{sub 4}, K{sub 2}SO{sub 4} and Na{sub 2}SO{sub 4}. The amount of fuel-ash-related sulphur sorption increases during co-combustion. Therefore, sorbents for sulphur reduction may not be required if proper control of the biomass feed is maintained. This paper presented a study in which the sulphation characteristics of calcium-rich paper sludge ash were determined for the use of co-combustion of biomass and coal. The calcium in the paper sludge ash came from the limestone filler used in the manufacturing process to increase the density and whiteness of the paper at 2 paper mills in Korea. A thermobalance reactor along with XRD and SEM-EDX were used for the analysis of sulphated ash to determine the effects of sulphation temperature, particle size and SO{sub 2} concentration on sulphation conversion. The activation energy and pre-exponential factor of sulphation reaction of sludge ash were determined based on the uniform-reaction model. X-ray diffraction analysis revealed that most of the sulphation compounds were CaSO{sub 4}. The sulphation occurred uniformly throughout the ash and the CaSO{sub 4} did not block the outer pore of the sludge ash. The uniform distributions of CaO and other inert minerals in the ash resulted in uniform sulphation with good penetration of SO{sub 2} into pores of the sludge ash without pore blocking during sulphation of CaO. 13 refs., 1 tab., 9 figs.

  6. Effect of ash components on the ignition and burnout of high ash coals

    Energy Technology Data Exchange (ETDEWEB)

    Feng, B.; Yan, R.; Zheng, C.G. [Huazhong University of Science and Technology, Wuhan (China). National Laboratory of Coal Combustion

    1998-11-01

    The effect of the ash components on the ignition and burnout of four Chinese high ash coals were studied by thermogravimetric analysis. To investigate the influence of the ash components, comparative experiments were carried out with original, deashed and impregnated coals. Eleven types of ash components, such as SiO{sub 2}, CaCO{sub 3}, MgO, Na{sub 2}CO{sub 3}, K{sub 2}CO{sub 3}, Al{sub 2}O{sub 3}, TiO{sub 2}, Fe{sub 2}O{sub 3}, FeS{sub 2}, NH{sub 4}Fe(SO{sub 4}){sub 2}{center_dot}12H{sub 2}O and FeSO{sub 4},(NH{sub 4}){center_dot}6H{sub 2}O were used in the present study. It was found that most of the ash components have negative effects. The strong influence of some ash components suggests that the combustion characteristics of high ash coal may be determined by the ash composition. 5 refs., 2 figs., 2 tabs.

  7. Scale-Up and Demonstration of Fly Ash Ozonation Technology

    Energy Technology Data Exchange (ETDEWEB)

    Rui Afonso; R. Hurt; I. Kulaots

    2006-03-01

    The disposal of fly ash from the combustion of coal has become increasingly important. When the fly ash does not meet the required specification for the product or market intended, it is necessary to beneficiate it to achieve the desired quality. This project, conducted at PPL's Montour SES, is the first near full-scale ({approx}10 ton/day), demonstration of ash ozonation technology. Bituminous and sub bituminous ashes, including two ash samples that contained activated carbon, were treated during the project. Results from the tests were very promising. The ashes were successfully treated with ozone, yielding concrete-suitable ash quality. Preliminary process cost estimates indicate that capital and operating costs to treat unburned carbon are competitive with other commercial ash beneficiation technologies at a fraction of the cost of lost sales and/or ash disposal costs. This is the final technical report under DOE Cooperative Agreement No.: DE-FC26-03NT41730.

  8. Characteristics of wet work in nurses

    NARCIS (Netherlands)

    Jungbauer, FHW; Steenstra, FB; Groothoff, JW; Coenraads, PJ

    2005-01-01

    Background objectives: Nursing is known for its high prevalence of hand dermatitis, mainly caused by the intense exposure to wet work in nursing activities. We aimed to study the characteristics of wet work exposure in nursing. Method: Trained observers monitored the duration and frequency of differ

  9. Anomalous wetting of helium on cesium

    International Nuclear Information System (INIS)

    The authors report studies of the anomalous wetting of a cesium substrate by a liquid helium film by means of the technique of third sound. A hysteretic pre-wetting transition is observed as a function of the amount of helium in the experimental cell. 10 refs., 2 figs

  10. International Database of Volcanic Ash Impacts

    Science.gov (United States)

    Wallace, K.; Cameron, C.; Wilson, T. M.; Jenkins, S.; Brown, S.; Leonard, G.; Deligne, N.; Stewart, C.

    2015-12-01

    Volcanic ash creates extensive impacts to people and property, yet we lack a global ash impacts catalog to organize, distribute, and archive this important information. Critical impact information is often stored in ephemeral news articles or other isolated resources, which cannot be queried or located easily. A global ash impacts database would improve 1) warning messages, 2) public and lifeline emergency preparation, and 3) eruption response and recovery. Ashfall can have varying consequences, such as disabling critical lifeline infrastructure (e.g. electrical generation and transmission, water supplies, telecommunications, aircraft and airports) or merely creating limited and expensive inconvenience to local communities. Impacts to the aviation sector can be a far-reaching global issue. The international volcanic ash impacts community formed a committee to develop a database to catalog the impacts of volcanic ash. We identify three user populations for this database: 1) research teams, who would use the database to assist in systematic collection, recording, and storage of ash impact data, and to prioritize impact assessment trips and lab experiments 2) volcanic risk assessment scientists who rely on impact data for assessments (especially vulnerability/fragility assessments); a complete dataset would have utility for global, regional, national and local scale risk assessments, and 3) citizen science volcanic hazard reporting. Publication of an international ash impacts database will encourage standardization and development of best practices for collecting and reporting impact information. Data entered will be highly categorized, searchable, and open source. Systematic cataloging of impact data will allow users to query the data and extract valuable information to aid in the development of improved emergency preparedness, response and recovery measures.

  11. Long term wet spent nuclear fuel storage

    International Nuclear Information System (INIS)

    The meeting showed that there is continuing confidence in the use of wet storage for spent nuclear fuel and that long-term wet storage of fuel clad in zirconium alloys can be readily achieved. The importance of maintaining good water chemistry has been identified. The long-term wet storage behaviour of sensitized stainless steel clad fuel involves, as yet, some uncertainties. However, great reliance will be placed on long-term wet storage of spent fuel into the future. The following topics were treated to some extent: Oxidation of the external surface of fuel clad, rod consolidation, radiation protection, optimum methods of treating spent fuel storage water, physical radiation effects, and the behaviour of spent fuel assemblies of long-term wet storage conditions. A number of papers on national experience are included

  12. Dewatering of ashes from mixed fuels. Experiences and results from Tekniska Verken in Linkoeping; Avvattning av aska fraan blandbraenslen. Erfarenheter och resultat fraan Tekniska Verken i Linkoeping

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Ulf; Fredriksson, Anders; Lindahl, Inge [Tekniska Verken i Linkoeping AB (Sweden); Arevius, Anna; Sjoeblom, Rolf [AaF-Energikonsult AB, Stockholm (Sweden)

    2003-12-01

    Unit 3 at Tekniska Verken i Linkoeping (TVL) has a grid type furnace. During the firing season 2000 - 2001, the fuel has been comprising 45 % recovered wood chip, 45 % bark and 10 % recovered plastic material. The outfeed has been wet, and flyash and bottom ash have been mixed in the process. During 1999, about 19,000 tonnes of ash with a water content of about 50 % have been generated. The procedure has implied drawbacks in the form of handling of sludge and disposal of material with a high water content. The purpose of the work carried out has been to provide a basis for design of a handling in which these drawbacks have been eliminated, and which supports other destinations for the bottom ash than disposal. The search for information showed that a number of reactions, in particular hydratisation and recrystallisation, take place when ash is in contact with water. The process is strongly dependent on the chemical composition of the ash. The result is influenced not only by the chemical reactions that occur but also by the order in which they take place. Fly ash is very reactive while bottom ash is relatively inert. The experiments in the laboratory scale showed that bottom ash drained well while fly ash as well as different mixtures of fly ash and bottom ash are relatively impermeable to water. The ageing experiments which were carried out did not indicate any particular alteration in the permeability. Tests on a reduced scale clearly showed that bottom ash drains rapidly without the aid of vacuum and that the field capacity (the relative amount of water which does not drain) is low. Mixtures of bottom ash and fly ash drained more when vacuum was applied. However, such mixtures cured within a few hours and this lead to a substantial decrease in permeability. Tests on a pilot scale were conducted using three different methods of dewatering. The tests on self-percolation showed that most of the drainage water appeared during the first few hours where after the

  13. Precursor films in wetting phenomena

    International Nuclear Information System (INIS)

    The spontaneous spreading of non-volatile liquid droplets on solid substrates poses a classic problem in the context of wetting phenomena. It is well known that the spreading of a macroscopic droplet is in many cases accompanied by a thin film of macroscopic lateral extent, the so-called precursor film, which emanates from the three-phase contact line region and spreads ahead of the latter with a much higher speed. Such films have been usually associated with liquid-on-solid systems, but in the last decade similar films have been reported to occur in solid-on-solid systems. While the situations in which the thickness of such films is of mesoscopic size are fairly well understood, an intriguing and yet to be fully understood aspect is the spreading of microscopic, i.e. molecularly thin, films. Here we review the available experimental observations of such films in various liquid-on-solid and solid-on-solid systems, as well as the corresponding theoretical models and studies aimed at understanding their formation and spreading dynamics. Recent developments and perspectives for future research are discussed. (topical review)

  14. Precursor films in wetting phenomena.

    Science.gov (United States)

    Popescu, M N; Oshanin, G; Dietrich, S; Cazabat, A-M

    2012-06-20

    The spontaneous spreading of non-volatile liquid droplets on solid substrates poses a classic problem in the context of wetting phenomena. It is well known that the spreading of a macroscopic droplet is in many cases accompanied by a thin film of macroscopic lateral extent, the so-called precursor film, which emanates from the three-phase contact line region and spreads ahead of the latter with a much higher speed. Such films have been usually associated with liquid-on-solid systems, but in the last decade similar films have been reported to occur in solid-on-solid systems. While the situations in which the thickness of such films is of mesoscopic size are fairly well understood, an intriguing and yet to be fully understood aspect is the spreading of microscopic, i.e. molecularly thin, films. Here we review the available experimental observations of such films in various liquid-on-solid and solid-on-solid systems, as well as the corresponding theoretical models and studies aimed at understanding their formation and spreading dynamics. Recent developments and perspectives for future research are discussed. PMID:22627067

  15. Ash melting behavior by Fourier transform infrared spectroscopy

    Institute of Scientific and Technical Information of China (English)

    LI Han-xu; QIU Xiao-sheng; TANG Yong-xin

    2008-01-01

    A Fourier Transform Infrared Spectroscopic (FTIR) method involving a Fe2O3 flux was used to learn how China's coal ash melts. The relationship between ash fusion temperature and chemical composition, as well as the effects of Fe2O3 flux on the ash fusion temperature were studied. The relationship between ash fusion temperature and chemical composition, mineralogical phases and functional groups was analyzed with the FTIR method. The results show that the ash fusion temperature is related to the location and transmittance of certain absorption peaks, which is of great significance for the study of ash behavior.

  16. Sterilization Effect of Wet Oxygen Plasma in the Bubbling Method.

    Science.gov (United States)

    Tamazawa, Kaoru; Shintani, Hideharu; Tamazawa, Yoshinori; Shimauchi, Hidetoshi

    2015-01-01

    A new low-temperature sterilization method to replace the ethylene oxide gas sterilization is needed. Strong bactericidal effects of OH and O2H radicals are well known. The purpose of this study was to evaluate the sterilization effect of wet oxygen ("O2+H2O") plasma in the bubbling method, confirming the effect of humidity. Sterility assurance was confirmed by using a biological indicator (Geobacillus stearothermophilus ATCC7953, Namsa, USA). One hundred and eight samples (10(5) spores/carrier) were divided into three groups of 36 in each for treatment with a different type of gas (O2, O2+H2O, Air+H2O). Plasma processing was conducted using a plasma ashing apparatus (13.56 MHz, PACK-3(®), Y. A. C., Japan) under various gas pressures (13, 25, 50 Pa) and gas flows (50, 100, 200 sccm). Fixed plasma treatment parameters were power at 150 W, temperature of 60 ℃, treatment time of 10 min. The samples after treatment were incubated in trypticase soy broth at 58 ℃ for 72 h. The negative culture rate in the "O2+H2O" group was significantly (Mantel-Haenszel procedure, psterilization effect of the "O2+H2O" group depends on the bubbling method which is the method of introducing vapor into the chamber. The bubbling method seems able to generate OH and O2H radicals in a stable way. PMID:26699857

  17. Effects of the addition of oil shale ash and coal ash on physic-chemical properties of CPJ45 cement

    Directory of Open Access Journals (Sweden)

    Nabih K.

    2014-04-01

    Full Text Available We focused our research on recycling industrial wastes, fly ash (F.A, bottom ash (B.A and oil shale ash (S.A in cement production. The study concerns physico-chemical characterization of these products and the influence of their addition on the mechanical proprieties of the CPJ45 cement. XRF allowed us to rank the three additives used according to their contents on major oxides. Coal ashes belong to the class F, and thus possess poozzolanic properties and oil shale ash belongs to the class C and possesses hydraulic and poozolanic properties. The crystalline phases constituting each ash were analysed by XRD. We observe in bottom ash the presence of quartz and mullite. The same crystals are found in fly ash with hematite and magnetite. Oil shale ash is composed of quartz, anhydrite, gehlenite, wollastonite and periclase. The microstructures of fly ash and bottom ash were studied using SEM. The bottom ash was composed respectively of fine particles that are generally irregularly shaped, their dimensions are between 5 and 28μm and of big particles(300 μm. The EDX analysis coupled with an electronic microscope provided some information about the major elements that constitute our samples. The dehydrations of anhydrous and three days hydrated cement were examined by DSC. For hydrated cements we noticed endothermic peaks related to the dehydration of CSH, CH and decomposition of carbonates. The study of the mechanical properties of CPJ45 cement by adding different proportions of fly ash, bottom ash and oil shale ash helped clarifying the percentage of ash that leaded to improve the 28 days mechanical strength. The results show that the cements studied have their maximum mechanical resistance with the addition at 7% of fly ash or 10% of oil shale ash.

  18. Interspecific proteomic comparisons reveal ash phloem genes potentially involved in constitutive resistance to the emerald ash borer.

    Directory of Open Access Journals (Sweden)

    Justin G A Whitehill

    Full Text Available The emerald ash borer (Agrilus planipennis is an invasive wood-boring beetle that has killed millions of ash trees since its accidental introduction to North America. All North American ash species (Fraxinus spp. that emerald ash borer has encountered so far are susceptible, while an Asian species, Manchurian ash (F. mandshurica, which shares an evolutionary history with emerald ash borer, is resistant. Phylogenetic evidence places North American black ash (F. nigra and Manchurian ash in the same clade and section, yet black ash is highly susceptible to the emerald ash borer. This contrast provides an opportunity to compare the genetic traits of the two species and identify those with a potential role in defense/resistance. We used Difference Gel Electrophoresis (DIGE to compare the phloem proteomes of resistant Manchurian to susceptible black, green, and white ash. Differentially expressed proteins associated with the resistant Manchurian ash when compared to the susceptible ash species were identified using nano-LC-MS/MS and putative identities assigned. Proteomic differences were strongly associated with the phylogenetic relationships among the four species. Proteins identified in Manchurian ash potentially associated with its resistance to emerald ash borer include a PR-10 protein, an aspartic protease, a phenylcoumaran benzylic ether reductase (PCBER, and a thylakoid-bound ascorbate peroxidase. Discovery of resistance-related proteins in Asian species will inform approaches in which resistance genes can be introgressed into North American ash species. The generation of resistant North American ash genotypes can be used in forest ecosystem restoration and urban plantings following the wake of the emerald ash borer invasion.

  19. Characteristics of MSWI fly ash during vitrification

    Institute of Scientific and Technical Information of China (English)

    TIAN Shu-lei; WANG Qi; WANG Qun-hui; MA Hong-zhi

    2009-01-01

    The vitrification characteristics of municipal solid waste incinerator (MSWI) fly ash were investigated. Effects of temperature on the binding efficiency of heavy metals, the change of chemical compositions and the weight loss of fly ash in the range of 800 - 1350 ℃ were studied. Toxicity Characteristic Leaching Procedure (TCLP) of the United States was used to analyze the leaching characteristics of heavy metals in fly ash and molten slag. Results indicate that chemical compositions, the weight loss of fly ash and the binding efficiency of heavy metals in fly ash have a tremendous change in the range of 1150 - 1260 ℃. The percentage of CaO, SiO2and AI203 increases with the increasing temperature, whereas it is contrary for SO3 , K2O, Na20 and CI; especially when the temperature is 1260 ℃, the percentage of these four elements decreases sharply from 43.72%to 0. 71%. The weight loss occurs obviously in the range of 1150 - 1260 ℃. Heavy metals of Pb and Cd are almost vaporized above 1000 ℃. Cr is not volatile and its binding efficiency can reach 100% below 1000 ℃. Resuits of TCLP indicate that the heavy metal content of molten slag is beyond stipulated limit values.

  20. Data insertion in volcanic ash cloud forecasting

    Directory of Open Access Journals (Sweden)

    Kate Louise Wilkins

    2015-03-01

    Full Text Available During the eruption of Eyjafjallajökull in April and May 2010, the London Volcanic Ash Advisory Centre demonstrated the importance of infrared (IR satellite imagery for monitoring volcanic ash and validating the Met Office operational model, NAME. This model is used to forecast ash dispersion and forms much of the basis of the advice given to civil aviation. NAME requires a source term describing the properties of the eruption plume at the volcanic source. Elements of the source term are often highly uncertain and significant effort has therefore been invested into the use of satellite observations of ash clouds to constrain them. This paper presents a data insertion method, where satellite observations of downwind ash clouds are used to create effective ‘virtual sources’ far from the vent. Uncertainty in the model output is known to increase over the duration of a model run, as inaccuracies in the source term, meteorological data and the parameterizations of the modelled processes accumulate. This new technique, where the dis- persion model (DM is ‘reinitialized’ part-way through a run, could go some way to addressing this. 

  1. Preliminary Study of Fly Ash Ceramic Process

    International Nuclear Information System (INIS)

    Preliminary study of ceramic production process from two components ofwhich are fly ash and feldspar has been done. Aluminosilicate substancecontained in the fly ash is a basic material a former ceramic body, if itfired at the temperature of 1000 oC forms mullite (3Al2O3.2SiO2). Mulliteis a refractory material which is very stable at the temperature changing.This experiment studies the ceramic production process of two componentsnamely fly ash with particle size of oC.Steps of processes are making paste of fly ash and feldspar, making of greenpellets, and firing of pellets, physical analysis of ceramic including volumedecrease, lost ignition, porosity, density, water sorption, compressivestrength. The experiment result at firing temperature of 1000 oC were shownthat best composition at the weight ratio of fly ash to feldspar are 60/40and 50/50. It physical characteristic respectively are decrease of volume0.54 and 0.69 %, lost ignition = 11.98 and 11.78 %, porosity = 0.159 and0.155, density = 2.05 and 2.06 g/cm3, water sorption = 18.96 and 18.36 %,compressive strength = 24.82 and 24.79 kN/mm2. (author)

  2. The effect of coal rank on the wettability behavior of wet coal system with injection of carbon dioxide and flue gas

    OpenAIRE

    Shojaikaveh, N.; Rudolph, E.S.J.; Wolf, K.H.A.A.; Ashrafizadeh, S.N.

    2012-01-01

    The injection of carbon dioxide (CO2) or flue gas into coal layers enhances the coal bed methane production (ECBM) and is also an option for CO2-storage. The success of this combined process depends strongly on the wetting behavior of the coal, which is a function of coal rank, ash content, pressure, temperature and composition of the gas. Two coal samples have been used for this study representing different ranks: hvBb and semi-anthracite rank. The wettability behaviour of the wet coal sampl...

  3. Regular Recycling of Wood Ash to Prevent Waste Production (RecAsh). Technical Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Lars E-mail: lars.t.andersson@skogsstyreslen.se

    2007-03-15

    At present, the extraction of harvest residues is predicted to increase in Sweden and Finland. As an effect of the intensified harvesting, the export of nutrients and acid buffering substances from the growth site is also increased. Wood ash could be used to compensate forest soils for such losses. Most wood fuel ash is today often deposited in landfills. If the wood ash is recycled, wood energy is produced without any significant waste production. Ash recycling would therefore contribute to decreasing the production of waste, and to maintaining the chemical quality of forest waters and biological productivity of forest soils in the long term. The project has developed, analysed and demonstrated two regular ash-recycling systems. It has also distributed knowledge gathered about motives for ash recycling as well as technical and administrative solutions through a range of media (handbooks, workshops, field demonstrations, reports, web page and information videos). Hopefully, the project will contribute to decreasing waste problems related to bio-energy production in the EU at large. The project has been organised as a separate structure at the beneficiary and divided in four geographically defined subprojects, one in Finland and three in Sweden (Central Sweden, Northern Sweden, and South-western Sweden). The work in each subproject has been lead by a subproject leader. Each subproject has organised a regional reference group. A project steering committee has been established consisting of senior officials from all concerned partners. The project had nine main tasks with the following main expected deliverables and output: 1. Development of two complete full-scale ash-recycling systems; 2. Production of handbooks of the ash recycling system; 3. Ash classification study to support national actions for recommendations; 4. Organise regional demonstrations of various technical options for ash treatment and spreading; 5. Organise national seminars and demonstrations of

  4. Coal R & D Case study: utilisation of fly ash and desulphurisation residues

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    A significant proportion of fly ash from coal-fired plant in Europe is currently used as a constituent of cements and mortars or for the manufacture of concrete and lightweight insulating materials. Similarly, a substantial amount of the gypsum produced from wet limestone and wet lime flue gas desulphurisation (FGD) processes employed in many coal-fired plant is used in the manufacture of cements, wallboards and other construction materials. Despite this, however, considerable quantities of fly ash, particularly that with a high carbon content, and desulphurisation residues, particularly non-gypsum ones, currently have no commercial applications. Disposal of these residues is costly and creates environmental problems. As a result, there is considerable interest in most European countries in developing processes for upgrading these residues into construction materials. Through a collaborative European initiate, a laboratory-scale process was developed to produce calcium sulphoaluminate (CSA) cements using high carbon content fly ash and FGD residues, particularly non-gypsum ones. Samples from a number of European coal-fired power plant were used in the development of this process. The cements produced look attractive for application as replacements for Ordinary Portland Cement (OPC), constituents of blended cement and constituents of ready mixed and pre-cast concretes. Further work is now required to optimise the process to manufacture CSA cements and to demonstrate them at pilot scale prior to commercialisation. Approaches have been made to power plant operators regarding the construction and trial operation of a pilot-scale CSA cement production facility at a European coal-fired power station. 3 figs., 3 tabs.

  5. Order of wetting transitions in electrolyte solutions

    Energy Technology Data Exchange (ETDEWEB)

    Ibagon, Ingrid, E-mail: ingrid@is.mpg.de; Bier, Markus, E-mail: bier@is.mpg.de; Dietrich, S. [Max-Planck-Institut für Intelligente Systeme, Heisenbergstr. 3, 70569 Stuttgart, Germany and IV. Institut für Theoretische Physik, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart (Germany)

    2014-05-07

    For wetting films in dilute electrolyte solutions close to charged walls we present analytic expressions for their effective interface potentials. The analysis of these expressions renders the conditions under which corresponding wetting transitions can be first- or second-order. Within mean field theory we consider two models, one with short- and one with long-ranged solvent-solvent and solvent-wall interactions. The analytic results reveal in a transparent way that wetting transitions in electrolyte solutions, which occur far away from their critical point (i.e., the bulk correlation length is less than half of the Debye length) are always first-order if the solvent-solvent and solvent-wall interactions are short-ranged. In contrast, wetting transitions close to the bulk critical point of the solvent (i.e., the bulk correlation length is larger than the Debye length) exhibit the same wetting behavior as the pure, i.e., salt-free, solvent. If the salt-free solvent is governed by long-ranged solvent-solvent as well as long-ranged solvent-wall interactions and exhibits critical wetting, adding salt can cause the occurrence of an ion-induced first-order thin-thick transition which precedes the subsequent continuous wetting as for the salt-free solvent.

  6. Order of wetting transitions in electrolyte solutions

    International Nuclear Information System (INIS)

    For wetting films in dilute electrolyte solutions close to charged walls we present analytic expressions for their effective interface potentials. The analysis of these expressions renders the conditions under which corresponding wetting transitions can be first- or second-order. Within mean field theory we consider two models, one with short- and one with long-ranged solvent-solvent and solvent-wall interactions. The analytic results reveal in a transparent way that wetting transitions in electrolyte solutions, which occur far away from their critical point (i.e., the bulk correlation length is less than half of the Debye length) are always first-order if the solvent-solvent and solvent-wall interactions are short-ranged. In contrast, wetting transitions close to the bulk critical point of the solvent (i.e., the bulk correlation length is larger than the Debye length) exhibit the same wetting behavior as the pure, i.e., salt-free, solvent. If the salt-free solvent is governed by long-ranged solvent-solvent as well as long-ranged solvent-wall interactions and exhibits critical wetting, adding salt can cause the occurrence of an ion-induced first-order thin-thick transition which precedes the subsequent continuous wetting as for the salt-free solvent

  7. Characteristic of elements in coal bottom ash and fly ash by instrumental neutron activation analysis (INAA)

    International Nuclear Information System (INIS)

    Coal-fired power plant and industrial stacks that using coal produce solid waste such as bottom ash and fly ash. Determination of elements in these wastes qualitatively and quantitatively is usually the first step taken for subsequent evaluation of the associated environmental and biological risks. In this study, the determination of trace elements in bottom ash and fly ash by instrumental neutron activation analysis was carried out. The samples were irradiated at rabbit facility in G.A. Siwabessy reactor with neutron flux ~ 1013 n.cm-2.s-1, and then counted by HPGe spectrometer gamma detector. The validation of method was performed by characterization of standard reference material (SRM) 1633b coal fly ash from National Institute of Standards and Technology (NIST). Some elements such as Al, As, Ce, Co, Cr, Cs, Fe, K, La, Mn, Na, Sc, Sm, Ti and V were detected in both samples. The concentration of environmentally toxic elements, As and Cr in bottom ash were 6.24 and 137.4 mg/kg, whereas in fly ash were 6.37 and 39.0 mg/kg respectively. Arsenic concentrations had been over the standard value based on PP no.85/1999. (author)

  8. Correlation between the critical viscosity and ash fusion temperatures of coal gasifier ashes

    Energy Technology Data Exchange (ETDEWEB)

    Hsieh, Peter Y. [National Energy Technology Lab. (NETL), Albany, OR (United States); Kwong, Kyei-Sing [National Energy Technology Lab. (NETL), Albany, OR (United States); Bennett, James [National Energy Technology Lab. (NETL), Albany, OR (United States)

    2015-09-27

    Coal gasification yields synthesis gas, an important intermediate in chemical manufacturing. It is also vital to the production of liquid fuels through the Fischer-Tropsch process and electricity in Integrated Gasification Combined Cycle power generation. Minerals naturally present in coal become molten in entrained-flow slagging gasifiers. Molten coal ash slag penetrates and dissolves refractory bricks, leading to costly plant shutdowns. The extent of coal ash slag penetration and refractory brick dissolution depends on the slag viscosity, the gasification temperature, and the composition of slag and bricks. Here, we measured the viscosity of several synthetic coal ash slags with a high-temperature rotary viscometer and their ash fusion temperatures through optical image analysis. We made all measurements in a carbon monoxide-carbon dioxide reducing atmosphere that approximates coal gasification conditions. Empirical correlation models based on ash fusion temperatures were used to calculate critical viscosity temperatures based on the coal ash compositions. These values were then compared with those obtained from thermodynamic phase-transition models. Finally, an understanding of slag viscosity as a function of ash composition is important to reducing refractory wear in slagging coal gasifiers, which would help to reduce the cost and environmental impact of coal for chemical and electricity production.

  9. Wetting reversal in colloid-polymer systems.

    Science.gov (United States)

    Blokhuis, Edgar M; Kuipers, Joris

    2010-05-01

    The wetting of a phase-separated colloid-polymer mixture in contact with a hard wall is analyzed using free volume theory in a Nakanishi-Fisher-type approach. We present results for the wetting phase diagram for several model approximations. Our analysis is compared with a previous analysis by Aarts [J. Chem. Phys. 120, 1973 (2004)]. We find that there is a crossover from wetting to drying at a threshold value for the colloid-polymer size ratio and that the transitions are close to the critical point and of second order in nature. PMID:20866234

  10. Assessing fly ash treatment: Remediation and stabilization of heavy metals

    DEFF Research Database (Denmark)

    Lima, A.T.; Ottosen, Lisbeth M.; Ribeiro, Alexandra B.

    2012-01-01

    Fly ashes from Municipal Solid Waste (MSW), straw (ST) and co-combustion of wood (CW) are here analyzed with the intent of reusing them. Two techniques are assessed, a remediation technique and a solidification/stabilization one. The removal of heavy metals from fly ashes through the...... electrodialytic process (EDR) has been tried out before. The goal of removing heavy metals has always been the reuse of fly ash, for instance in agricultural fields (BEK). The best removal rates are here summarized and some new results have been added. MSW fly ashes are still too hazardous after treatment to even...... consider application to the soil. ST ash is the only residue that gets concentrations low enough to be reused, but its fertilizing value might be questioned. An alternative reuse for the three ashes is here preliminary tested, the combination of fly ash with mortar. Fly ashes have been substituted by...

  11. About the mineralogical composition of Estonian oil shale ash

    International Nuclear Information System (INIS)

    Results of previous research about the mineralogical composition of Estonian oil shale ash focused on using X-ray diffractometry, problems related to oil shale combustion, and utilization of oil shale ashes were analysed. (author)

  12. Market assessment and technical feasibility study of PFBC ash use

    Energy Technology Data Exchange (ETDEWEB)

    Smith, V.E.; Bland, A.E.; Brown, T.H. [Western Research Inst., Laramie, WY (United States); Georgiou, D.N. [Jacques, Whitford and Associates Ltd., Dartmouth, NS (Canada); Wheeldon, J. [Electric Power Research Inst., Palo Alto, CA (United States)

    1994-10-01

    The overall objectives of this study are to determine the market potential and the technical feasibility of using PFBC ash in high volume ash use applications. The information will be of direct use to the utility industry in assessing the economics of PFBC power generation in light of ash disposal avoidance through ash marketing. In addition, the research is expected to result in the generation of generic data on the use of PFBC ash that could lead to novel processing options and procedures. The specific objectives of the proposed research and demonstration effort are: Define resent and future market potential of PFBC ash for a range of applications (Phase I); assess the technical feasibility of PFBC ash use in construction, civil engineering and agricultural applications (Phase II); and demonstrate the most promising of the market and ash use options in full-scale field demonstrations (Phase III).

  13. Environmental risks of biomass ashes application in soils [Resumo

    OpenAIRE

    Freire, M; Lopes, M. Helena; Tarelho, L.

    2014-01-01

    This work presents the potential environmental risks of biomass ashes application in forest soils. The ashes were collected in five industrial biomass thermal plants using different technologies: bubbling fluidized bed combustor and grate furnace.

  14. Changeing of fly ash leachability after grinding

    Science.gov (United States)

    Lakatos, J.; Szabo, R.; Racz, A.; Banhidi, O.; Mucsi, G.

    2016-04-01

    Effect of grinding on the reactivity of fly ash used for geopolymer production was tested. Extraction technique using different alkaline and acidic solutions were used for detect the change of the solubility of elements due to the physical and mechano-chemical transformation of minerals in function of grinding time. Both the extraction with alkaline and acidic solution have detected improvement in solubility in function of grinding time. The enhancement in alkaline solution was approx. 100% in case of Si and Al. The acidic medium able to dissolve the fly ash higher manner than the alkaline, therefore the effect of grinding was found less pronounced.

  15. Utilization options for fly ash, bottom ash, and slag in Eastern Europe

    Energy Technology Data Exchange (ETDEWEB)

    Manz, O.E.

    1995-12-01

    Since 1967, at least six ash utilization symposiums have been held in the United States, with papers presented by several European authors on the utilization of coal by-products in Eastern Europe. There is currently over 80,000 megawatts of installed coal-fired capacity available in that region. Unfortunately, of the 117,778,000 tonnes of fly ash, bottom ash, and slag produced in Eastern Europe in 1989, only 13% was utilized. This paper outlines the research and levels and kinds of coal by-product utilization taking place in Eastern Europe since the late 1960s.

  16. Application of Fly Ash from Solid Fuel Combustion in Concrete

    OpenAIRE

    Pedersen, Kim Hougaard; Dam-Johansen, Kim; Jensen, Anker Degn

    2008-01-01

    Application of Fly Ash from Solid Fuel Combustion in Concrete Kim H. Pedersen Abstract Industrial utilization of fly ash from pulverized coal combustion plays an important role in environmentally clean and cost effective power generation. Today, the primary market for fly ash utilization is as pozzolanic additive in the production of concrete. However, the residual carbon in fly ash can adsorb the air entraining admixtures (AEAs) added to enhance air entrainment in concrete in order to increa...

  17. Granulated wood ash to forest soil - Ecological effects

    International Nuclear Information System (INIS)

    This report describes research concerning ecological effects of wood ash recycling to forest soils. The main part of the minerals in the wood fuels are retained in the ashes after combustion. By returning the ashes back to the cleared forest areas, the mineral losses can be reduced. Adding ashes and limestone is a method to vitalize acidified forest soils and restore the production capacity. 48 refs, 26 figs, 8 tabs

  18. Associative properties of 137Cs in biofuel ashes

    International Nuclear Information System (INIS)

    The present study aims to reveal how radiocesium is associated to the ash particles derived from biofuel combustion. A sequential extraction procedure was carried out for the characterisation of radiocesium speciation in ash generated by different fuels and burner types. The ash types considered were fly ash and bottom ash collected from Swedish district heating plants using bark wood or peat as fuel. A fraction of the radiocesium in biofuel ash can easily become solubilised and mobilised by water and also, a significant fraction of the radionuclides can be bound to the ash particles in cation-exchangeable forms. Therefore, at using the ash derived from biofuels to recycle mineral nutrients for forestry or short rotation coppicing, radiocesium solubilised and leached from the ash by rains has a potential to rather quickly enter the rooting zone of forest vegetation or energy crops. On the other hand, radiocesium strongly bound to the ash will migrate slowly into the soil column with the successive accumulation of litter and in the process act to maintain the external dose rate at an elevated level for a long time. The results of the sequential extraction procedure and activity determination of the different extracted fractions implies that the bioavailable fraction of radiocesium in ash from bark, wood or peat is in the range between 20-85% of the total ash contents. Peat ash collected from a powder burner strongly retained a large fraction (70-90%) of its radiocesium content while the peat ash from a continuos fluidized bed type burner retained nearly 100% of the radiocesium in the bottom ash and only about 15% in the fly ash

  19. Tualatin River - Wet Prairie Restoration Phase III

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Forty five acres of wet prairie and 11 acres of adjacent lands were treated for reed canarygrass in this ongoing project. Federally threatened Nelson’s...

  20. ROE Wet Nitrate Deposition 1989-1991

    Data.gov (United States)

    U.S. Environmental Protection Agency — The raster data represent the amount of wet nitrate deposition in kilograms per hectare from 1989 to 1991. Summary data in this indicator were provided by EPA’s...

  1. ROE Wet Sulfate Deposition 2009-2011

    Data.gov (United States)

    U.S. Environmental Protection Agency — The raster data represent the amount of wet sulfate deposition in kilograms per hectare from 2009 to 2011. Summary data in this indicator were provided by EPA’s...

  2. Wet Chemistry of Spinel Iron oxide Particles

    OpenAIRE

    Jolivet, J.; Chanéac, C.; Prené, P.; Vayssières, L.; Tronc, E.

    1997-01-01

    Various properties of spinel iron oxide nanograins are reviewed, illustrating the broad possibilities of wet chemistry for tailoring materials for a wide range of utilizations, from catalysis and sensors to cast magnetic materials.

  3. National Ignition Facility wet weather construction plan

    Energy Technology Data Exchange (ETDEWEB)

    Kugler, A N

    1998-01-01

    This report presents a wet weather construction plan for the National Ignition Facility (NIF) construction project. Construction of the NIF commenced in mid- 1997, and excavation of the site was completed in the fall. Preparations for placing concrete foundations began in the fall, and above normal rainfall is expected over the tinter. Heavy rainfall in late November impacted foundation construction, and a wet weather construction plan was determined to be needed. This wet weather constiction plan recommends a strategy, techniques and management practices to prepare and protect the site corn wet weather effects and allow construction work to proceed. It is intended that information in this plan be incorporated in the Stormwater Pollution Prevention Plan (SWPPP) as warranted.

  4. Optimizing and Characterizing Geopolymers from Ternary Blend of Philippine Coal Fly Ash, Coal Bottom Ash and Rice Hull Ash

    Directory of Open Access Journals (Sweden)

    Martin Ernesto Kalaw

    2016-07-01

    Full Text Available Geopolymers are inorganic polymers formed from the alkaline activation of amorphous alumino-silicate materials resulting in a three-dimensional polymeric network. As a class of materials, it is seen to have the potential of replacing ordinary Portland cement (OPC, which for more than a hundred years has been the binder of choice for structural and building applications. Geopolymers have emerged as a sustainable option vis-à-vis OPC for three reasons: (1 their technical properties are comparable if not better; (2 they can be produced from industrial wastes; and (3 within reasonable constraints, their production requires less energy and emits significantly less CO2. In the Philippines, the use of coal ash, as the alumina- and silica- rich geopolymer precursor, is being considered as one of the options for sustainable management of coal ash generation from coal-fired power plants. However, most geopolymer mixes (and the prevalent blended OPC use only coal fly ash. The coal bottom ash, having very few applications, remains relegated to dumpsites. Rice hull ash, from biomass-fired plants, is another silica-rich geopolymer precursor material from another significantly produced waste in the country with only minimal utilization. In this study, geopolymer samples were formed from the mixture of coal ash, using both coal fly ash (CFA and coal bottom ash (CBA, and rice hull ash (RHA. The raw materials used for the geopolymerization process were characterized using X-ray fluorescence spectroscopy (XRF for elemental and X-ray diffraction (XRD for mineralogical composition. The raw materials’ thermal stability and loss on ignition (LOI were determined using thermogravimetric analysis (TGA and reactivity via dissolution tests and inductively-coupled plasma mass spectrometry (ICP analysis. The mechanical, thermal and microstructural properties of the geopolymers formed were analyzed using compression tests, Fourier transform infra-red spectroscopy (FTIR

  5. AUTOMATION OF THE RESISTIVITY MEASUREMENT FOR FLY ASH

    Science.gov (United States)

    The article describes the automation of the resistivity measurement for fly ash. Fly ash resistivity is an important consideration in the operation of particulate control devices based on electrostatic principles (the higher the resistivity of the fly ash, the more difficult it i...

  6. Ash Deposition Trials at Three Power Stations in Denmark

    DEFF Research Database (Denmark)

    Laursen, Karin; Frandsen, Flemming; Larsen, Ole Hede

    1998-01-01

    the probe temperature did influence the composition of deposits for coals with medium ash deposition propensities. These results may indicate that coals with medium to high ash deposition propensities in existing boilers may cause increasing ash deposit formation in future boilers with higher steam...

  7. 77 FR 55895 - Permanent Closure of Cincinnati Blue Ash Airport

    Science.gov (United States)

    2012-09-11

    ... Federal Aviation Administration Permanent Closure of Cincinnati Blue Ash Airport AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of permanent closure of Cincinnati Blue Ash Airport (ISZ). SUMMARY: The... Cincinnati advising that on August 29, 2012, it was permanently closing Cincinnati Blue Ash Airport...

  8. Evaluation of Pollutant Leaching Potential of Coal Ashes for Recycling

    Science.gov (United States)

    Park, D.; Woo, N. C.; Kim, H.; Yoon, H.; Chung, D.

    2011-12-01

    By 2009, coal ashes produced from coal-based power plants in Korea have been reused as cement supplement materials; however, the rest is mostly disposed in landfills inside the plant properties. Continuous production of coal ashes and limited landfill sites require more recycles of coal ashes as base materials, specifically in constructions of roads and of huge industrial complex. Previous researches showed that coal ashes could contain various metals such as arsenic(As), chromium(Cr), lead(Pb), nickel(Ni), selenium(Se), etc. In this study, we collected four types of bottom ashes and two of fly ashes from four coal-based power plants. These ash samples were tested with distilled water through the column leaching process in oxidized conditions. The column test results were compared with those of total digestion, sequential extraction processes and TCLP. Concentrations of metals in outflows from columns are generally greater in fly ashes than in bottom ashes, specifically for As, Se, B, Sr and SO4. Only one fly ash (J2-F) shows high concentrations of arsenic and selenium in leachate. Sequential extraction results indicate that these metals are in readily soluble forms, such as adsorbed, carbonated, and reducible forms. Results of TCLP analysis indicate no potential contaminants leached from the ashes. In conclusion, recycling of coal combustion ashes could be encouraged with proper tests such as sequential and leaching experiments.

  9. Economic analysis of emerald ash borer (Coleoptera: Buprestidae) management options.

    Science.gov (United States)

    Vannatta, A R; Hauer, R H; Schuettpelz, N M

    2012-02-01

    Emerald ash borer, Agrilus planipennis (Fairmaire) (Coleoptera: Buprestidae), plays a significant role in the health and extent of management of native North American ash species in urban forests. An economic analysis of management options was performed to aid decision makers in preparing for likely future infestations. Separate ash tree population valuations were derived from the i-Tree Streets program and the Council of Tree and Landscape Appraisers (CTLA) methodology. A relative economic analysis was used to compare a control option (do-nothing approach, only removing ash trees as they die) to three distinct management options: 1) preemptive removal of all ash trees over a 5 yr period, 2) preemptive removal of all ash trees and replacement with comparable nonash trees, or 3) treating the entire population of ash trees with insecticides to minimize mortality. For each valuation and management option, an annual analysis was performed for both the remaining ash tree population and those lost to emerald ash borer. Retention of ash trees using insecticide treatments typically retained greater urban forest value, followed by doing nothing (control), which was better than preemptive removal and replacement. Preemptive removal without tree replacement, which was the least expensive management option, also provided the lowest net urban forest value over the 20-yr simulation. A "no emerald ash borer" scenario was modeled to further serve as a benchmark for each management option and provide a level of economic justification for regulatory programs aimed at slowing the movement of emerald ash borer. PMID:22420272

  10. Biodegradation of wet-white leather

    OpenAIRE

    Ollé Otero, Lluís; Jorba Rafart, Montse; Font Vallès, Joaquim; Shendrik, Alexander; Bacardit Dalmases, Anna

    2011-01-01

    This paper deals with the study of the physical, chemical and biological processes associated with the deterioration of wet-white leather. The samples of leather were exposed for eight months to outdoor weathering and then their properties were subsequently evaluated. The results indicate that resistance and dimensional stability of wet-white (THPS-syntan) leather is higher than that of chrometanned leather. The comparative work with chrome leather was described earlier.

  11. Curvature controlled wetting in two dimensions

    DEFF Research Database (Denmark)

    Gil, Tamir; Mikheev, Lev V.

    1995-01-01

    A complete wetting transition at vanishing curvature of the substrate in two-dimensional circular geometry is studied by the transfer matrix method. We find an exact formal mapping of the partition function of the problem onto that of a (1+1)-dimensional wetting problem in planar geometry. As the...... term reduces the thickness by the amount proportional to r0-1/3...

  12. Fundamental Difficulties Associated With Underwater Wet Welding

    OpenAIRE

    Joshua E. Omajene,; Jukka Martikainen

    2014-01-01

    The offshore industries carry out welding activities in the wet environment. It is evident that the wet environments possess difficulties in carrying out underwater welding. Therefore there is the need to improve the quality of weld achieved in underwater welding. This paper investigates the difficulties associated with underwater welding. The objective of this research paper is to identify and analyze the different difficulties in underwater welding so as to make a clear back...

  13. Surface and Hydrodynamic Forces in Wetting Films

    OpenAIRE

    Pan, Lei

    2013-01-01

    The process of froth flotation relies on using air bubbles to collect desired mineral particles dispersed in aqueous media on the surface, while leaving undesirous mineral particles behind. For a particle to be collected on the surface of a bubble, the thin liquid films (or wetting films) of water formed in between must rupture. According to the Frumkin-Derjaguin isotherm, it is necessary that wetting films can rupture when the disjoining pressures are negative. However, the negative disjoini...

  14. Wetting and phase separation at surfaces

    Indian Academy of Sciences (India)

    Sanjay Puri; Kurt Binder

    2005-06-01

    We study the problem of surface-directed spinodal decomposition, viz., the dynamical interplay of wetting and phase separation at surfaces. In particular, we focus on the kinetics of wetting-layer growth in a semi-infinite geometry for arbitrary surface potentials and mixture compositions. We also present representative results for phase separation in confined geometries, e.g., cylindrical pores, thin films, etc.

  15. Complete wetting of graphene by biological lipids

    Science.gov (United States)

    Luan, Binquan; Huynh, Tien; Zhou, Ruhong

    2016-03-01

    Graphene nanosheets have been demonstrated to extract large amounts of lipid molecules directly out of the cell membrane of bacteria and thus cause serious damage to the cell's integrity. This interesting phenomenon, however, is so far not well understood theoretically. Here through extensive molecular dynamics simulations and theoretical analyses, we show that this phenomenon can be categorized as a complete wetting of graphene by membrane lipids in water. A wetting-based theory was utilized to associate the free energy change during the microscopic extraction of a lipid with the spreading parameter for the macroscopic wetting. With a customized thermodynamic cycle for detailed energetics, we show that the dispersive adhesion between graphene and lipids plays a dominant role during this extraction as manifested by the curved graphene. Our simulation results suggest that biological lipids can completely wet the concave, flat or even convex (with a small curvature) surface of a graphene sheet.Graphene nanosheets have been demonstrated to extract large amounts of lipid molecules directly out of the cell membrane of bacteria and thus cause serious damage to the cell's integrity. This interesting phenomenon, however, is so far not well understood theoretically. Here through extensive molecular dynamics simulations and theoretical analyses, we show that this phenomenon can be categorized as a complete wetting of graphene by membrane lipids in water. A wetting-based theory was utilized to associate the free energy change during the microscopic extraction of a lipid with the spreading parameter for the macroscopic wetting. With a customized thermodynamic cycle for detailed energetics, we show that the dispersive adhesion between graphene and lipids plays a dominant role during this extraction as manifested by the curved graphene. Our simulation results suggest that biological lipids can completely wet the concave, flat or even convex (with a small curvature) surface of a

  16. Estimating evaporation from a wet grassland

    OpenAIRE

    Gasca-Tucker, D. L.; Acreman, M. C.; Agnew, C. T.; Thompson, J R

    2007-01-01

    Wet grasslands are being restored across the UK and Europe to reinstate their high biodiversity following over 50 years of drainage and conversion to arable agriculture. The water balance of many wet grasslands is dominated by precipitation and evaporation and it is essential to quantify evaporation rates to understand the hydrological functioning of wetlands and the implications for water resources in catchments where wetlands are being restored. This paper considers data from direct measure...

  17. Avalanche Dynamics in Wet Granular Materials

    OpenAIRE

    Tegzes, P.; Vicsek, T.; P. Schiffer

    2002-01-01

    We have studied the dynamics of avalanching wet granular media in a rotating drum apparatus. Quantitative measurements of the flow velocity and the granular flux during avalanches allow us to characterize novel avalanche types unique to wet media. We also explore the details of viscoplastic flow (observed at the highest liquid contents) in which there are lasting contacts during flow, leading to coherence across the entire sample. This coherence leads to a velocity independent flow depth at h...

  18. Processing of Sugarcane Bagasse ash and Reactivity of Ash-blended Cement Mortar

    Science.gov (United States)

    Ajay, Goyal; Hattori, Kunio; Ogata, Hidehiko; Ashraf, Muhammad

    Sugarcane bagasse ash (SCBA), a sugar-mill waste, has the potential of a partial cement replacement material if processed and obtained under controlled conditions. This paper discusses the reactivity of SCBA obtained by control burning of sugarcane bagasse procured from Punjab province of India. X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques were employed to ascertain the amorphousness and morphology of the minerals ash particles. Destructive and non-destructive tests were conducted on SCBA-blended mortar specimens. Ash-blended cement paste specimens were analyzed by XRD, thermal analysis, and SEM methods to evaluate the hydration reaction of SCBA with cement. Results showed that the SCBA processed at 600°C for 5 hours was reactive as ash-blended mortar specimens with up to 15% substitution of cement gave better strength than control specimens.

  19. Root secretion stimulating ash growth in larch-ash mixed forest

    Institute of Scientific and Technical Information of China (English)

    吴俊民; 刘广平; 王晓水; 吴保国

    2000-01-01

    Allelopathic effect of larch (Larix gmelini ) on the ash growth (Fraximus mandshurica) was studied in artificial cultivation tests. The results revealed that the larch root secretion obviously stimulated the ash growth. In order to determine the main stimulation allelochemicals, the chemical composition was analyzed. By contrasting the contents of carbohydrate and aminoacid in root secretion of larch and ash, it was concluded that the carbohydrate and aminoacid were not important stimulation allelochemicals. The organic acid and other components in root secretion of larch and ash were analyzed by GC and GC-MS analysis. The sand culture tests were carried out with selected model compounds. The results showed that benzeneacetic acid, benzenepropionic acid and phenolic acids in root secretion of larch were the main stimulation allelochemicals.

  20. Mössbauer characterization of feed coal, ash and fly ash from a thermal power plant

    Energy Technology Data Exchange (ETDEWEB)

    Reyes Caballero, F.; Martínez Ovalle, S. A., E-mail: s.agustin.martinez@uptc.edu.co; Moreno Gutiérrez, M. [Universidad Pedagógica y Tecnológica de Colombia, UPTC, Grupo de Física Nuclear Aplicada y Simulación (Colombia)

    2015-06-15

    The aim of this work was apply {sup 57}Fe Transmission Mössbauer Spectroscopy at room temperature in order to study the occurrence of iron-containing mineral phases in: 1) feed coal; 2) coal ash, obtained in different stages of the ASTM D3174 standard method; and 3) fly ash, produced when coal is burned in the TERMOPAIPA IV thermal power plant localized in Boyacá, Colombia. According to obtained results, we can conclude the occurrence of pyrite and jarosite in the feed coal; Fe{sup 2+} and Fe{sup 3+} crystalline paramagnetic phases, superparamagnetic hematite and hematite in coal ash; Fe{sup 2+} and Fe{sup 3+} noncrystalline and crystalline phases, magnetite and hematite in fly ash. Precisely, for a basic understanding, this work discusses some the possible transformations that take place during coal combustion.

  1. Mössbauer characterization of feed coal, ash and fly ash from a thermal power plant

    International Nuclear Information System (INIS)

    The aim of this work was apply 57Fe Transmission Mössbauer Spectroscopy at room temperature in order to study the occurrence of iron-containing mineral phases in: 1) feed coal; 2) coal ash, obtained in different stages of the ASTM D3174 standard method; and 3) fly ash, produced when coal is burned in the TERMOPAIPA IV thermal power plant localized in Boyacá, Colombia. According to obtained results, we can conclude the occurrence of pyrite and jarosite in the feed coal; Fe2+ and Fe3+ crystalline paramagnetic phases, superparamagnetic hematite and hematite in coal ash; Fe2+ and Fe3+ noncrystalline and crystalline phases, magnetite and hematite in fly ash. Precisely, for a basic understanding, this work discusses some the possible transformations that take place during coal combustion

  2. FLY ASH RECYCLE IN DRY SCRUBBING

    Science.gov (United States)

    The paper describes the effects of fly ash recycle in dry scrubbing. (Previous workers have shown that the recycle of product solids improves the utilization of slaked lime--Ca(OH)2--for sulfur dioxide (SO2) removal by spray dryers with bag filters.) In laboratory-scale experimen...

  3. Determination of strontium 90 in milk Ash

    International Nuclear Information System (INIS)

    This report describes a method of determination of 90Sr in milk ashes by extraction of 90Y in TBP. The tests which led to the choice of the operating process are presented together with tire result of an intercomparison. (author)

  4. SODA ASH TREATMENT OF NEUTRALIZED MINE DRAINAGE

    Science.gov (United States)

    Utilization of acid mine drainage (AMD) streams as a source of potable and industrial water has become a major goal of several proposed AMD treatment schemes. From among the various schemes available, the lime neutralization/soda ash softening process was selected for use at Alto...

  5. Phosphorus recovery from sewage sludge char ash

    NARCIS (Netherlands)

    Atienza-Martinez, M.; Gea, G.; Arauzo, J.; Kersten, S.R.A.; Kootstra, A.M.J.

    2014-01-01

    Phosphorus was recovered from the ash obtained after combustion at different temperatures (600 °C, 750 °C and 900 °C) and after gasification (at 820 °C using a mixture of air and steam as fluidising agent) of char from sewage sludge fast pyrolysis carried out at 530 °C. Depending on the leaching con

  6. Lignite and conditioned ash handling systems

    Energy Technology Data Exchange (ETDEWEB)

    Bibolini, P.; Di Giacomo, L.; Ruga, A.M. [Techint (Italy)

    2001-10-01

    This article discusses Techint's latest contract for the engineering and supply of a lignite and conditioned ash handling system. Techint Italimpianti, the materials handling unit of Techint Technologies has served the market for over 40 years as a leading supplier of a range of systems for the handling of iron ore, pellets, coal, cement, bauxite, and aluminium. 6 figs.

  7. Arthur Ashe Jr. Sports Scholars Awards 2011

    Science.gov (United States)

    Elfman, Lois; Walker, Marlon A.

    2011-01-01

    "Diverse: Issues In Higher Education" established the Sports Scholars Awards to honor undergraduate students of color who have made achieving both academically and athletically a winning combination. Inspired by tennis legend Arthur Ashe Jr.'s commitment to education as well as his love for the game of tennis, "Diverse" invites every college and…

  8. Arthur Ashe Jr. Sports Scholars Awards 2010

    Science.gov (United States)

    Elfman, Lois; Ford, William J.

    2010-01-01

    "Diverse: Issues In Higher Education" established the Sports Scholars Awards to honor undergraduate students of color who have made achieving both academically and athletically a winning combination. Inspired by tennis legend Arthur Ashe Jr.'s commitment to education as well as his love for the game of tennis, they invite every college and…

  9. 1997 Arthur Ashe Jr. Sport Scholars Awards.

    Science.gov (United States)

    Roach, Ronald

    1997-01-01

    Winners of the "Black Issues in Higher Education" Arthur Ashe Jr. 1997 athletes of the year, one male and one female, are profiled and Sport Scholars are listed for baseball, softball, basketball, fencing, archery, football, handball, soccer, field hockey, crew, swimming, gymnastics, tennis, squash, golf, volleyball, lacrosse, wrestling, water…

  10. A study on fiy ash: ballistic separation of a fly ash

    OpenAIRE

    Peris Mora, Eduardo; Payá, Jordi; Monzó, José

    1991-01-01

    The object of this study is the characterization of several sized fractions from a "spanish fly ash" originating in the thermoelectric power plant in Andorra (Teruel). Physical (size distributions, densities) chemical (chemical composition) and mineralogical characteristics (X-ray diffractograms and infrared spectra) for those sized fractions have been analyzed. Initial fly ash was ballistically separated (horizontal draft) into four fractions using an aerodynamic tunnel with hori...

  11. Application of polymeric flocculant for enhancing settling of the pond ash particles and water drainage from hydraulically stowed pond ash

    Institute of Scientific and Technical Information of China (English)

    Mishra Devi Prasad; Das Samir Kumar

    2013-01-01

    Delayed settling of the ash particles and poor drainage of water from the pond ash are the major problems faced during the hydraulic stowing of pond ash.In this study the effect of polymeric flocculant on settling of the ash particles and drainage of water during pond ash stowing are investigated.In addition,the parameters,viz.drainage and absorption of water during pond ash stowing are quantified by stowing a mine goaf model with pond ash slurries of five different concentrations added with and without flocculant.The study revealed that addition of only 5 × 10-6 of Sodium Carboxymethyl Cellulose (Na-CMC)flocculant with the pond ash slurries during stowing offers best result in terms of quicker settling of the ash particles and enhanced water drainage from the hydraulically stowed pond ash.Besides,it resulted in drainage of more than 85% of the total water used in the initial 45 min of stowing.The improvement in drainage is caused due to coagulation and flocculation of the pond ash particles because of charge neutralization and particle-particle bridging.This study may provide a basis for estimating the drainage and absorption of water during the real pond ash stowing operation in underground mines.

  12. Availability of residual phosphorus from broiler litter ash and layer manure ash amended soil for Paspalum vaginatum uptake

    Science.gov (United States)

    It has been hypothesized by several scientists that poultry litter ash could be used as a slow releasing phosphorus fertilizer that will become available over time. To test this hypothesis, a greenhouse study was conducted using a broiler litter ash, layer manure ash and calcium phosphate to determ...

  13. Radiobiological waste treatment-ashing treatment and immobilization with cement

    International Nuclear Information System (INIS)

    This report describes the results of the study on the treatment of radioactive biological waste in the China Institute for Radiation Protection (CIRP). The possibility of radiobiological waste treatment was investigated by using a RAF-3 type rapid ashing apparatus together with the immobilization of the resulted ash. This rapid ashing apparatus, developed by CIRP, is usually used for pretreatment of samples prior to chemical analysis and physical measurements. The results show that it can ash 3 kg of animal carcasses a batch, the ashing time is 5-7 h and the ash content is less than 4 wt%. The ashing temperature not exceeding 450 deg. C was used without any risk of high losses of radionuclides. The ash from the rapid ashing apparatus was demonstrated to be immobilized with ordinary silicate cement. The optimum cement/ash/water formulation of the cemented waste form was 35 ± 5 wt% cement, 29 ± 2 wt% water, and 36 ± 6 wt% ash. The performance of the waste form was in compliance with the technical requirements except for impact resistance. Mixing additives in immobilization formulations can improve the performance of the cemented ash waste form. The additives chosen were DH4A flow promoter as a cement additive and vermiculite or zeolite as a supplement. The recommended formulation, i.e. an improved formulation of the cemented ash waste form is that additives DH4A flow promoter and vermiculite (or zeolite) are added on the ground of optimum cement/ash/water formulation of the cemented waste form, the dosage of water, DH4A and vermiculite (or zeolite) is 70 wt%, 0.5 wt% and ≤ 5 wt% of the cement dosage, respectively. The cemented ash waste forms obtained meet all the requirements for disposal. (author). 12 refs, 7 figs, 13 tabs

  14. The adsorption of HCl on volcanic ash

    Science.gov (United States)

    Gutiérrez, Xochilt; Schiavi, Federica; Keppler, Hans

    2016-03-01

    Understanding the interaction between volcanic gases and ash is important to derive gas compositions from ash leachates and to constrain the environmental impact of eruptions. Volcanic HCl could potentially damage the ozone layer, but it is unclear what fraction of HCl actually reaches the stratosphere. The adsorption of HCl on volcanic ash was therefore studied from -76 to +150 °C to simulate the behavior of HCl in the dilute parts of a volcanic plume. Finely ground synthetic glasses of andesitic, dacitic, and rhyolitic composition as well as a natural obsidian from Vulcano (Italy) served as proxies for fresh natural ash. HCl adsorption is an irreversible process and appears to increase with the total alkali content of the glass. Adsorption kinetics follow a first order law with rate constants of 2.13 ṡ10-6 s-1 to 1.80 ṡ10-4 s-1 in the temperature range investigated. For dacitic composition, the temperature and pressure dependence of adsorption can be described by the equation ln ⁡ c = 1.26 + 0.27 ln ⁡ p - 715.3 / T, where c is the surface concentration of adsorbed HCl in mg/m2, T is temperature in Kelvin, and p is the partial pressure of HCl in mbar. A comparison of this model with a large data set for the composition of volcanic ash suggests that adsorption of HCl from the gas phase at relatively low temperatures can quantitatively account for the majority of the observed Cl concentrations. The model implies that adsorption of HCl on ash increases with temperature, probably because of the increasing number of accessible adsorption sites. This temperature dependence is opposite to that observed for SO2, so that HCl and SO2 are fractionated by the adsorption process and the fractionation factor changes by four orders of magnitude over a temperature range of 250 K. The assumption of equal adsorption of different species is therefore not appropriate for deriving volcanic gas compositions from analyses of adsorbates on ash. However, with the experimental

  15. Ash3d: A finite-volume, conservative numerical model for ash transport and tephra deposition

    Science.gov (United States)

    Schwaiger, Hans F.; Denlinger, Roger P.; Mastin, Larry G.

    2012-01-01

    We develop a transient, 3-D Eulerian model (Ash3d) to predict airborne volcanic ash concentration and tephra deposition during volcanic eruptions. This model simulates downwind advection, turbulent diffusion, and settling of ash injected into the atmosphere by a volcanic eruption column. Ash advection is calculated using time-varying pre-existing wind data and a robust, high-order, finite-volume method. Our routine is mass-conservative and uses the coordinate system of the wind data, either a Cartesian system local to the volcano or a global spherical system for the Earth. Volcanic ash is specified with an arbitrary number of grain sizes, which affects the fall velocity, distribution and duration of transport. Above the source volcano, the vertical mass distribution with elevation is calculated using a Suzuki distribution for a given plume height, eruptive volume, and eruption duration. Multiple eruptions separated in time may be included in a single simulation. We test the model using analytical solutions for transport. Comparisons of the predicted and observed ash distributions for the 18 August 1992 eruption of Mt. Spurr in Alaska demonstrate to the efficacy and efficiency of the routine.

  16. Rice Husk Ash Derived Zeolite Blended with Water Hyacinth Ash for Enhanced Adsorption of Cadmium Ions

    Directory of Open Access Journals (Sweden)

    G. W. Mbugua

    2014-08-01

    Full Text Available In order to helpcurtail or imposesustained control to the offensive water hyacinth plant,it is essential to explore ways of generatingwater remediation materials from it. In the current study, the capacity and efficacy of water hyacinth ash (WHA,its insoluble residue (WHAR and rice husk ash (RHAto remove cadmium ionsand methylene blue from contaminated water was investigated. Mixtures of the two ashes were used to formulatezeolitic materialsby hydrothermal reactions. Material A, ZMA was prepared by using rice husk ash and the soluble portion of WHA while for material B, ZMB a mixture of equal amounts the two ashes including the insoluble fraction of WHA were used. Batch experiments was carried out to determine the effect of metal ion concentration, initial PH, contact time (t, temperature (T, shaking speed and adsorbent dose on percentage removal of Cd2+ and methylene blue by the ashes and their zeolitic products. The data obtained for adsorption of Cd2+ on RHA, ZMA, and ZMB was found to best fit in the Langmuir isotherm model while WHA and WHAR data best fitted in theFreundlich model. Adsorption capacities for cadmium on RHA, WHA, WHAR, ZMA and ZMB adsorbents ions were 3.745, 52.00, 56.89, 11.24 and 22.22mg/g respectively.The findings showed that incorporating the WHAR during synthesis of the zeolitic material enhanced its adsorption capacity and efficiency for Cd (II ions and methylene blue.

  17. Ash management in circulating fluidized bed combustors

    Energy Technology Data Exchange (ETDEWEB)

    K. Redemann; E.-U. Hartge; J. Werther [Hamburg University of Technology, Hamburg (Germany). Institute of Solids Process Engineering and Particle Technology

    2008-12-15

    Ash management in fluidized bed combustion systems means keeping the particle size distribution of the bed inventory in a given range. A dynamic particle population balancing model was developed for this purpose. It was successfully applied to a refuse-derived fuel fired combustor and a coal-fired circulating fluidized bed combustor. Both were large-scale commercial units. The model uses the concept of the attrited ash particle size distribution which represents the particle size distribution of the attrited ash including the generated fines and replaces the consideration of the particle attrition in the model calculations. The model offers the possibility to gain additional information about the particle size distributions and the solids mass flows at any location of the fluidized bed system. In addition, the model provides information about the dynamic behavior of the plant and about mean residence times of particle size classes in the plant. Uncertainties about the ash formation characteristics of fuels make the management of the bed inventory a very important issue. In this context the population balancing model is used to predict the plant behavior under various operating conditions. The results of the calculations carried out give useful information about the possibilities to manage the ash inventory of such a plant. It could be shown that the recirculation of a fine fraction of the bottom drain solids is a very effective method to manage the particle size distribution of the bed inventory. The calculation results further reveal that the mean residence time of particles is strongly dependent on their size. 21 refs., 19 figs., 4 tabs.

  18. Hot-Gas Filter Ash Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    Dockter, B.A.; Hurley, J.P.; Watne, T.A.; Katrinak, K.A.; O`Keefe, C.A. [North Dakota Univ., Grand Forks, ND (United States). Energy and Minerals Research Center

    1996-12-31

    Large-scale hot-gas testing over the past several years has revealed numerous cases of cake buildup on filter elements that have been difficult, if not impossible to remove. At times, the cake can bridge between candle filters, leading to high filter failure rates. Physical factors, including particle-size distribution, particle shape, the aerodynamics of deposition, and system temperature contribute to difficulty in removing the cake. It is speculated that chemical as well as physical effects are playing a role in leading the ash to bond to the filter or to itself. The Energy and Environmental research Center (EERC) at the University of North Dakota is working with Electric Power Research Institute (EPRI) and a consortium of companies in partnership with the US Department of Energy (DOE) to perform the research necessary to determine the factors that cause hot-gas cleanup filters to be blinded by ash or to develop deposits that can bridge the filters and cause them to fail. The objectives of this overall project are threefold: first, to determine the mechanisms by which difficult-to-clean ash is formed; second, to develop a method to determine the rate of blinding/bridging based on fuel and sorbent properties and operating conditions; finally, to provide suggestions fro ways to prevent filter blinding by the troublesome ash. The projects consists of four tasks: field sampling and archive sample analyses, laboratory-scale testing, bench-scale testing, and model and database development testing. This paper present preliminary data from Task 2 on determining the tensile strengths of coal ash particles at elevated temperatures and simulated combustor gas conditions.

  19. Plutonium dissolution from Rocky Flats Plant incinerator ash

    International Nuclear Information System (INIS)

    Rockwell Hanford Operations (Rockwell) soon will commence recovery of plutonium from Rocky Flats Plant incinerator ash. In preparation for this processing, Rockwell undertook literature and laboratory studies to identify, select and optimize plutonium dissolution methods for treating the ash. Ash reburning, followed by dissolution in nitric acid containing calcium fluoride, was selected as the processing method for the ash. Recommended values of process parameters were identified. Using the selected process, 99.5% plutonium recovery was achieved, leaving about 12.7 wt % heel residue for an equal weight composite of the three ashes tested. 15 refs., 26 figs

  20. Future fly ash marketing; Flugaschevermarktung in der Zukunft

    Energy Technology Data Exchange (ETDEWEB)

    Mauder, R.; Hugot, A. [Evonik Power Minerals GmbH, Dinslaken (Germany)

    2008-07-01

    It can be assumed that the fly ash production volumes will undergo a marked increase over the next few years. The conditions of fly ash production will improve as a result of modern and refurbished power plants, yielding a positive effect on the quality of fly ashes. Other vital parameters of future fly ash marketing are fly ash logistics and the infrastructure of power plants. Basically, economic utilisation of the increased production volumes is possible; however, new and long-term strategies are necessary. (orig.)

  1. Analysis list: ash1 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ash1 Cell line + dm3 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/ash1.1.t...sv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/ash1.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/ash...1.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/ash1.Cell_line.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/Cell_line.gml ...

  2. Analysis list: ash2 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ash2 Larvae + dm3 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/ash2.1.tsv ...http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/ash2.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/ash...2.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/ash2.Larvae.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/Larvae.gml ...

  3. Reducing the environmental impact of Baltic Power Plant ash fields

    International Nuclear Information System (INIS)

    Ash fields of Estonian oil-shale-fired power plants, especially ash hydrotransport system with its large amounts of high-alkaline waters, may cause great damage to the environment. The situation is particularly bad at the Baltic Power Plant whose ash fields and sediment ponds occupy more than ten square kilometers. The samples taken from the 2nd ash field were studied to determine their structure, pressure resistance and water filtration ability. Ash field material has a stratified structure, all layers contain Ca(OH)2 which, contacting with water, makes the latter highly alkaline. According to preliminary calculations, the ash field material binds only 10-20 % of CO2 emitted at oil shale burning. Disconnection of the 2nd ash field from the ash field water-sluicing system would be the first and most practical way to reduce the amount of water to be added to the water system of ash fields. Ca(OH)2 content of ash field material must be considered when making the projects for the 2nd ash field recultivation. (author)

  4. Experimental study on fly ash capture mercury in flue gas

    Institute of Scientific and Technical Information of China (English)

    Mercedes; DíAZ-SOMOANO; Patricia; ABAD-VALLE; M.Rosa; MARTíNEZ-TARAZONA

    2010-01-01

    Systematic experiments were conducted on a fixed-bed reactor to investigate the interaction between fly ash and mercury,the results implied that fly ash can capture mercury effectively.Among different fly ashes,the unburned carbon in the FA2 and FA3 fly ashes has the highest mercury capture capacity,up to 10.3 and 9.36 μg/g,respectively,which is close to that of commercial activated carbon.There is no obvious relationship between mercury content and carbon content or BET surface area of fly ash.Petrography classification standard was applied to distinguish fly ash carbon particles.Carbon content is not the only variable that controls mercury capture on fly ash,there are likely significant differences in the mercury capture capacities of the various carbon forms.Mercury capture capacity mainly depends on the content of anisotropy carbon particles with porous network structure.

  5. Quantification of fusion in ashes from solid fuel combustion

    DEFF Research Database (Denmark)

    Hansen, Lone Aslaug; Frandsen, Flemming; Dam-Johansen, Kim;

    1999-01-01

    which the agreement with fusion as determined by phase diagrams is very good, and for straw (salt-rich) and coal (silicate-rich) ashes. Comparing ash fusion curves to index points of current standard ash fusion tests showed initial melting at temperatures typically between 50 degrees and 100 degrees C......The fusion of ashes produced during solid fuel combustion greatly affects the tendency of these ashes to cause operational problems in utility boilers. In this paper, a new and quantitative laboratory method for assessing the fusion of ashes based on simultaneous thermal analysis, STA, is described....... Using STA, melting is detected as an endothermic reaction involving no change in mass. The measurement signals are transferred into a fusion curve showing the melt fraction in the ash as a function of temperature. This is done either by a simple comparison of the energies used for melting in different...

  6. Chemical composition in relation with biomass ash structure

    Science.gov (United States)

    Holubcik, Michal; Jandacka, Jozef

    2014-08-01

    Biomass combustion can be more complicated like combustion of fossil fuels because it is necessary to solve problems with lower ash melting temperature. It can cause a lot of problems during combustion process. Chemical composition of biomass ash has great impact on sinters and slags creation in ash because it affects structure of heated ash. In this paper was solved relation between chemical composition and structure of heated ash from three types of biomass (spruce wood, miscanthus giganteus and wheat straw). Amount of SiO2, CaO, MgO, Al2O3 and K2O was determined. Structure of heated ash was optically determined after heating to 1000 °C or 1200 °C. Results demonstrated that chemical composition has strong effect on structure and color of heated ash.

  7. Ash transformation during co-firing coal and straw

    DEFF Research Database (Denmark)

    Zheng, Yuanjing; Jensen, Peter Arendt; Jensen, Anker Degn;

    2007-01-01

    Co-firing straw with coal in pulverized fuel boilers can cause problems related to fly ash utilization, deposit formation, corrosion and SCR catalyst deactivation due to the high contents of Cl and K in the ash. To investigate the interaction between coal and straw ash and the effect of coal...... quality on fly ash and deposit properties, straw was co-fired with three kinds of coal in an entrained flow reactor. The compositions of the produced ashes were compared to the available literature data to find suitable scaling parameters that can be used to predict the composition of ash from straw and...... coal co-firing. Reasonable agreement in fly ash compositions regarding total K and fraction of water soluble K was obtained between co-firing in an entrained flow reactor and full-scale plants. Capture of potassium and subsequent release of HCl can be achieved by sulphation with SO2 and more...

  8. Volcanic Ash fall Impact on Vegetation, Colima 2005

    Science.gov (United States)

    Garcia, M. G.; Martin, A.; Fonseca, R.; Nieto, A.; Radillo, R.; Armienta, M.

    2007-05-01

    An ash sampling network was established arround Colima Volcano in 2005. Ash fall was sampled on the North, Northeast, East, Southeast, South, Southwest and West of the volcano. Samples were analyzed for ash components, geochemistry and leachates. Ash fall ocurred on April (12), May (10, 23), June (2, 6, 9, 10, 12, 14), July (27), September (27), October (23) and November (24). Most of the ash is made of andesitic dome-lithics but shows diferences in crystal, juvenile material and lithic content. In May, some samples contained grey and dark pumice (scoria). Texture varies from phi >4 to phi 0. Leachate concentration were low: SO4 (7.33-54.19) Cl- (2.29-4.97) and F- (0.16-0.37). During 2005, Colima Volcano's ash fall rotted some of the guava and peach fruits and had a drying effect on spearment and epazote plants. Even these small ash amounts could have hindered sugar cane and agave growth.

  9. Possibilities of municipal solid waste incinerator fly ash utilisation.

    Science.gov (United States)

    Hartmann, Silvie; Koval, Lukáš; Škrobánková, Hana; Matýsek, Dalibor; Winter, Franz; Purgar, Amon

    2015-08-01

    Properties of the waste treatment residual fly ash generated from municipal solid waste incinerator fly ash were investigated in this study. Six different mortar blends with the addition of the municipal solid waste incinerator fly ash were evaluated. The Portland cement replacement levels of the municipal solid waste incinerator fly ash used were 25%, 30% and 50%. Both, raw and washed municipal solid waste incinerator fly ash samples were examined. According to the mineralogical composition measurements, a 22.6% increase in the pozzolanic/hydraulic properties was observed for the washed municipal solid waste incinerator fly ash sample. The maximum replacement level of 25% for the washed municipal solid waste incinerator fly ash in mortar blends was established in order to preserve the compressive strength properties. Moreover, the leaching characteristics of the crushed mortar blend was analysed in order to examine the immobilisation of its hazardous contents. PMID:26060198

  10. Sorption of aqueous phosphorus onto bituminous and lignitous coal ashes

    International Nuclear Information System (INIS)

    Aiming at the development of a phosphorus removal technology for waste water, phosphate (PO43-) retention behavior of bituminous and lignitous coal ashes was investigated using a batch reactor. Ash samples, including fresh and weathered fly and bottom ashes, were studied for their sorption isotherms and reversibility. Fly ashes had a much higher phosphate retention capacity (4000-30,000 mg P/kg) than bottom ashes (15-600 mg P/kg). Lignitous coal ashes were more capable of retaining phosphate than bituminous coal ashes. The retention process was largely irreversible, and the irreversibility increased with the increase in the retention capacity. Weathering enlarged the retention capacity of the bituminous bottom ash, but substantially lowered that of the fly ash, likely due to the difference in the weather-induced changes between the fly and bottom ashes. Sorption isotherms of fly ashes were found to be adequately represented by the Langmuir model while those of bottom ashes fitted better to the Freundlich model. Concentrations of Ca2+ and PO43- in the aqueous phase were measured at the end of sorption and desorption experiments, and were compared with solubilities of three calcium phosphate minerals. The aqueous solutions were saturated or super-saturated with respect to tricalcium phosphate (Ca3(PO4)2) and hydroxyapatite (Ca5(PO4)3OH), and slightly under-saturated with respect to amorphous calcium phosphate. It is concluded that precipitation of calcium phosphate is the predominant mechanism for phosphate retention by coal ash under the conditions studied. There is a strong and positive correlation between alkalinity and phosphate sorption capacity. Consequently, acid neutralization capacity (ANC) can be used as an indicator of phosphate sorption capacity of coal ashes

  11. Sorption of aqueous phosphorus onto bituminous and lignitous coal ashes

    Energy Technology Data Exchange (ETDEWEB)

    Yan Jinying; Kirk, Donald W. [Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario, M5S 3E5 (Canada); Jia, Charles Q. [Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario, M5S 3E5 (Canada)], E-mail: cqjia@chem-eng.toronto.edu; Liu Xinan [College of Chemical Engineering, Chongqing University, Chongqing (China)

    2007-09-05

    Aiming at the development of a phosphorus removal technology for waste water, phosphate (PO{sub 4}{sup 3-}) retention behavior of bituminous and lignitous coal ashes was investigated using a batch reactor. Ash samples, including fresh and weathered fly and bottom ashes, were studied for their sorption isotherms and reversibility. Fly ashes had a much higher phosphate retention capacity (4000-30,000 mg P/kg) than bottom ashes (15-600 mg P/kg). Lignitous coal ashes were more capable of retaining phosphate than bituminous coal ashes. The retention process was largely irreversible, and the irreversibility increased with the increase in the retention capacity. Weathering enlarged the retention capacity of the bituminous bottom ash, but substantially lowered that of the fly ash, likely due to the difference in the weather-induced changes between the fly and bottom ashes. Sorption isotherms of fly ashes were found to be adequately represented by the Langmuir model while those of bottom ashes fitted better to the Freundlich model. Concentrations of Ca{sup 2+} and PO{sub 4}{sup 3-} in the aqueous phase were measured at the end of sorption and desorption experiments, and were compared with solubilities of three calcium phosphate minerals. The aqueous solutions were saturated or super-saturated with respect to tricalcium phosphate (Ca{sub 3}(PO{sub 4}){sub 2}) and hydroxyapatite (Ca{sub 5}(PO{sub 4}){sub 3}OH), and slightly under-saturated with respect to amorphous calcium phosphate. It is concluded that precipitation of calcium phosphate is the predominant mechanism for phosphate retention by coal ash under the conditions studied. There is a strong and positive correlation between alkalinity and phosphate sorption capacity. Consequently, acid neutralization capacity (ANC) can be used as an indicator of phosphate sorption capacity of coal ashes.

  12. Can I Stop Myself From Having a Wet Dream?

    Science.gov (United States)

    ... Can I Stop Myself From Having a Wet Dream? KidsHealth > For Teens > Can I Stop Myself From Having a Wet Dream? Print A A A Text Size Can I stop myself from having a wet dream? – Tom* You really can't stop wet dreams, ...

  13. Influence of solution concentration of aluminium, arsenic, boron and copper on root growth in relation to the phytotoxicity of pulverized fuel ash

    Energy Technology Data Exchange (ETDEWEB)

    Collier, G.F.; Greenwood, D.J.

    1977-01-01

    To find whether the concentrations of aluminium, arsenic, boron or copper and soluble sulfate salts which have previously been found in the aqueous phase of water saturated pulverized fuel ash (PFA) are sufficiently high to restrict growth, lettuce seedlings were grown on filter paper saturated with a solution containing various concentrations of each of the different ions. Over a period of five days root growth was reduced by half when the concentration of aluminium was increased to 2.0 mg/liter, arsenic (As/sup 3 +/) to 1.6 mg/liter, boron to 90 mg/liter or copper to 0.3 mg/liter or when the soluble sulfate salts were increased to 100 mEq/liter (conductivity 8 x 10/sup -3/ ohm/sup -1/ cm/sup -1/ at 20/sup 0/C). The concentrations of ions in the aqueous phase of wet PFA depend on pH which varies greatly from one batch of ash to another. The concentrations of aluminium and copper in equilibrium with acid batches of ash and those of arsenic in equilibrium with alkaline batches of ash were sufficiently high to restrict growth. The concentration of boron and soluble salts were always at phytotoxic levels irrespective of the pH of the ash. 15 references, 6 figures, 4 tables.

  14. Wetting and adsorption modification in the system

    Directory of Open Access Journals (Sweden)

    Yuliya Bogdanova

    2015-09-01

    Full Text Available Regularities of wetting and adsorption modification of surfaces of continual membranes made from highly permeable glassy polymers poly[1-(trimethylsilyl-1-propyne] (PTMSP and poly(4-methyl-2-pentyn (PMP with aqueous ethanol solutions and alcohol solutions containing organic dyes (Solvent Blue 35 and Remazol Brilliant Blue were investigated. Isotherms of stress wetting of polymer membrane surface by etanol solutions were found out to have maximums in the range of concentrations corresponding to the beginning of liquid sorption into the membrane and polymer swelling. Thus, the principal possibility of optimization of nanofiltration experiments by liquid wetting angle measurements on continuous polymer membrane surfaces was shown. The presence of the dye was shown not to affect PMP wetting. But in the case of PTMSP, it leads to shear of the maximum of stress wetting isotherms to the range of higher concentrations. It was found out the effectiveness of the adsorption surface modification of continuous polymer membrane surfaces by ethanol solutions containing dyes does not dependent on chemical nature of the dye. At the same time, there are different trends in the energy characteristics of the membrane surface.

  15. WET STRENGTH PAPER REPULPING: LABORATORY EVALUATION

    Institute of Scientific and Technical Information of China (English)

    NishiK.Bhardwaj; VikasRajan; A.G.Kulkarni

    2004-01-01

    The recycling of wet strength papers in a normal recycling mill is often troublesome due to the severe operating conditions required to defibre wet strength papers. The various methods are presented which will quickly allow mills to determine the most effective pulping aids to use when repulping wet strength papers. The repulping of wet strength paper with inorganic chemicals was investigated in the laboratory. The effects of major variables, that is, repulping time, pulp consistency, soaking time, temperature, and reactant concentration in the repulping stage were examined using Plackett-Burman design. The repulping time was the most crucial & influential process variable affecting repulping characteristic and formation related properties. The more significant repulping process variables affecting pulp yield were repulping time, soaking temperature and pulp consistency whereas for formation index and feature size, repulping time, pulp consistency, soaking temperature and time were the more important variables. The formation index is increased by an increase in repulping time, pulp consistency and soaking time whereas the feature size is decreased by an increase in repulping time, soaking temperature and pulp consistency. The formation index and the rejects were more sensitive to changes in process variables than were the feature size or the pulp yield. The pulp recycled from wet strength waste paper had good physical strength properties.

  16. WET STRENGTH PAPER REPULPING:LABORATORY EVALUATION

    Institute of Scientific and Technical Information of China (English)

    Nishi K. Bhardwaj; Vikas Rajan; A.G. Kulkarni

    2004-01-01

    The recycling of wet strength papers in a normal recycling mill is often troublesome due to the severe operating conditions required to defibre wet strength papers. The various methods are presented which will quickly allow mills to determine the most effective pulping aids to use when repulping wet strength papers. The repulping of wet strength paper with inorganic chemicals was investigated in the laboratory. The effects of major variables, that is,repulping time, pulp consistency, soaking time,temperature, and reactant concentration in the repulping stage were examined using Plackett-Burman design. The repulping time was the most crucial & influential process variable affecting repulping characteristic and formation related properties. The more significant repulping process variables affecting pulp yield were repulping time,soaking temperature and pulp consistency whereas for formation index and feature size, repulping time,pulp consistency, soaking temperature and time were the more important variables. The formation index is increased by an increase in repulping time, pulp consistency and soaking time whereas the feature size is decreased by an increase in repulping time,soaking temperature and pulp consistency. The formation index and the rejects were more sensitive to changes in process variables than were the feature size or the pulp yield. The pulp recycled from wet strength waste paper had good physical strength properties.

  17. Wetting films on chemically patterned surfaces.

    Science.gov (United States)

    Karakashev, Stoyan I; Stöckelhuber, Klaus W; Tsekov, Roumen

    2011-11-15

    The behavior of thin wetting films on chemically patterned surfaces was investigated. The patterning was performed by means of imprinting of micro-grid on methylated glass surface with UV-light (λ=184.8 nm). Thus imprinted image of the grid contained hydrophilic cells and hydrophobic bars on the glass surface. For this aim three different patterns of grids were utilized with small, medium and large size of cells. The experiment showed that the drainage of the wetting aqueous films was not affected by the type of surface patterning. However, after film rupturing in the cases of small and medium cells of the patterned grid the liquid from the wetting film underwent fast self-organization in form of regularly ordered droplets covering completely the cells of the grid. The droplets reduced significantly their size upon time due to evaporation. In the cases of the largest cell grid, a wet spot on the place of the imprinted grid was formed after film rupturing. This wet spot disassembled slowly in time. In addition, formation of a periodical zigzag three-phase contact line (TPCL) was observed. This is a first study from the planned series of studies on this topic. PMID:21875710

  18. Energy and heat balance in wet DCT

    Energy Technology Data Exchange (ETDEWEB)

    Saxena, Viren; Moser, Alexander; Schaefer, Michael; Ritschel, Michael [BorgWarner Drivetrain Engineering GmbH, Ketsch (Germany)

    2012-11-01

    Wet clutch systems are well known for their thermal robustness and versatility in a wide range of automotive applications. Conventional automatics have used them for a long time as torque converter lock-up clutches, shift elements and launch clutches. With the development of DCTs, wet clutch technology has evolved in terms of launch and shift performance, controllability, robustness and efficiency. This paper discusses improvements in the wet clutch and their impact on today's vehicle applications in terms of heat and energy management. Thermal robustness is a crucial aspect for an automatic transmission. In addition to the clutch thermal performance, the influence of transmission oil cooler and oil sump warm-up behavior are discussed. Based on our latest development activities, test results and simulations, we shall discuss the latest friction material enhancement and its impact on DCTs in terms of efficiency and performance. Drag loss is a much-discussed topic during the development of wet clutch systems. This paper discusses in detail the cause and break-up of various energy losses in a wet DCT. Efficient energy management strategies for actuation systems, cooling, and lubrication, clutch apply, and pre-selection in modern power trains with engine start / stop are evaluated based on the latest test and simulation results. Finally, the paper summarizes the performance and efficiency optimized moist clutch system. (orig.)

  19. Design consideration for wet welded joints

    Energy Technology Data Exchange (ETDEWEB)

    Szelagowski, P.; Osthus, V. [GKSS Research Center, Geesthacht (Germany); Petershagen, H.; Pohl, R. [Univ. Hamburg (Germany). Inst. fuer Schiffbau; Lafaye, G. [Stolt Comex Seaway S.A., Marseille (France)

    1996-12-01

    Wet welding has become a joining technique that under certain circumstances can provide results which cannot be distinguished between wet or dry production and the achievable mechanical quality is comparable to dry atmospheric welds. Wet welding is not a process which can be applied easily and which can be properly handled by untrained diver welders. Wet welding is more than any other kind of welding process or procedure a joining technique that requires the full job-concentration and -knowledge of an excellent trained and skilled diver welder throughout the whole production time, who is 100% identifying himself with his task. Furthermore he must be fully aware of the production requirements and possible metallurgical/environmental reactions and outcomes. He must be able to be fully concentrated on the process performance throughout his total work shift. In short: he must be an outstanding expert in his field. The following paper will highlight these subjects and show the necessity of their exact observation to achieve excellent quality in wet welding.

  20. Advanced methods for the treatment of organic aqueous wastes: wet air oxidation and wet peroxide oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Debellefontaine, Hubert; Chakchouk, Mehrez; Foussard, Jean Noel [Institut National des Sciences Appliquees (INSA), 31 - Toulouse (France). Dept. de Genie des Procedes Industriels; Tissot, Daniel; Striolo, Phillipe [IDE Environnement S.A., Toulouse (France)

    1993-12-31

    There is a growing concern about the problems of wastes elimination. Various oxidation techniques are suited for elimination of organic aqueous wastes, however, because of the environmental drawbacks of incineration, liquid phase oxidation should be preferred. `Wet Air Oxidation` and `Wet Peroxide Oxidation`are alternative processes which are discussed in this paper. 17 refs., 13 figs., 4 tabs.

  1. Evaporation from rain-wetted forest in relation to canopy wetness, canopy cover, and net radiation

    NARCIS (Netherlands)

    Klaassen, W.

    2001-01-01

    Evaporation from wet canopies is commonly calculated using E-PM, the Penman-Monteith equation with zero surface resistance. However, several observations show a lower evaporation from rain-wetted forest. Possible causes for the difference between E-PM and experiments are evaluated to provide rules f

  2. Norm in coal, fly ash and cement

    International Nuclear Information System (INIS)

    Coal is technologically important materials being used for power generation and its cinder (fly ash) is used in manufacturing of bricks, sheets, cement, land filling etc. 222Rn (radon) and its daughters are the most important radioactive and potentially hazardous elements, which are released in the environment from the naturally occurring radioactive material (NORM) present in coal, fly ash and cement. Thus it is very important to carry out radioactivity measurements in coal, fly ash and cement from the health and hygiene point of view. Samples of coal and fly ash from different thermal power stations in northern India and various fly ash using establishments and commercially available cement samples (O.P.C. and P.P.C.) were collected and analyzed for radon concentration and exhalation rates. For the measurements, alpha sensitive LR-115 type II plastic track detectors were used. The radon concentration varied from 147 Bq/m3 to 443 Bq/m3, the radium concentration varied from 1.5 to 4.5 Bq/kg and radon exhalation rate varied from 11.8 mBq.kg-1.h-1 to 35.7 mBq.kg-1.h-1 for mass exhalation rate and from 104.5 mBq.m-2.h-1 to 314.8 mBq.m-2.h-1 for surface exhalation rate in coal samples. The radon concentration varied from 214 Bq/m3 to 590 Bq/m3, the radium concentration varied from 1.0 to 2.7 Bq/kg and radon exhalation rate varied from 7.8 mBq.kg-1.h-1 to 21.6 mBq.kg-1.h-1 for mass exhalation rate and from 138 mBq m-2h-1 to 380.6 mBq.m-2.h-1 for surface exhalation rate in fly ash samples. The radon concentration varied from 157.62 Bq/m3 to 1810.48 Bq/m3, the radium concentration varied from 0.76 Bq/kg to 8.73 Bq/kg and radon exhalation rate varied from 6.07 mBq.kg-1.hr-1 to 69.81 mBq.kg-1.hr-1 for mass exhalation rate and from 107.10 mBq.m-2.hr-1 to 1230.21 mBq.m-2.hr-1 for surface exhalation rate in different cement samples. The values were found higher in P.P.C. samples than in O.P.C. samples. (authors)

  3. Enhanced NOx removal in wet FGD systems

    International Nuclear Information System (INIS)

    The dominant method for high-efficiency NOx removal is ammonia-based selective catalytic reduction (SCR). However, no full-scale, commercial SCR process exists for coal-fired power plants in North America. This paper describes wet flue gas desulphurization (FGD), the leading control technology for sulphur dioxide emissions from coal-fired power plants. The feasibility of using wet FGD systems for simultaneous NOx and SO2 removal was studied in a mini-pilot scale perforated tray absorber by varying the NO to NO2 ratio in the inlet gas. It was shown that the presence of sulphite ions in stoichiometric excess in the liquid phase had a significant positive effect on the absorption of NOx in wet FGD systems. The pH of the absorbing solution was also found to have a major effect on NOx removal efficiency. 49 refs., 6 tabs., 14 figs

  4. NANOFILLERS FOR PAPERMAKING WET END APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Jing Shen

    2010-05-01

    Full Text Available The papermaking industry can benefit a lot from nanotechnology. This versatile technology can also be used in the area of fillers for papermaking wet end applications. In such applications the main technological examples currently available include wet end addition of commercially available nanofillers, formation of nanofiller/fiber or nanofiller/fibril hybrids, development of novel categories of nanofillers such as high aspect ratio nanofillers, and combination of microfillers with nanostructures by specially controlled routes to obtain composite nanofillers. It is worth noting that there are certain challenges associated with nanofillers, such as high cost, difficulty in structure and performance control, poor dispersability and retention, possible severe negative effects on paper strength, possible detrimental interactions between nanofillers with some wet end additives, and the industry-related limitations. However, in the long run, the research and development in the area of nanofillers will surely create many fruitful results.

  5. Molecular Dynamics Simulations for Predicting Surface Wetting

    Directory of Open Access Journals (Sweden)

    Jing Chen

    2014-06-01

    Full Text Available The investigation of wetting of a solid surface by a liquid provides important insights; the contact angle of a liquid droplet on a surface provides a quantitative measurement of this interaction and the degree of attraction or repulsion of that liquid type by the solid surface. Molecular dynamics (MD simulations are a useful way to examine the behavior of liquids on solid surfaces on a nanometer scale. Thus, we surveyed the state of this field, beginning with the fundamentals of wetting calculations to an examination of the different MD methodologies used. We highlighted some of the advantages and disadvantages of the simulations, and look to the future of computer modeling to understand wetting and other liquid-solid interaction phenomena.

  6. Handling of wet residues in industry

    DEFF Research Database (Denmark)

    Villanueva, Alejandro

    operational tools geared to assist industries in the selection of disposal routes for wet residues. The target group of the study are the wet residue producing companies. The study is structured in the form of a handbook, with the aim of making it simpler and faster for industries to find their way to...... feasible considering also economic and environmental criteria. It has been found that the advantages and disadvantages of a given disposal option, as a basis for decision-making, can be analysed using five assessment criteria:  legislation  technology  economy  environment  society concerns These five...... characterise the technical options, the costs, and the legal, environmental and social implications of residue disposal. The handbook contains a series of decision-support tools that enables a company to select a solution. In this way, wet residue handling can be tackled at an early phase of project design...

  7. Root cause analysis for wet waste generation

    International Nuclear Information System (INIS)

    Since, typically, most utility radioactive waste is dry waste, volume reduction efforts should start with this. However, significant cost can still be saved with a modest reduction in the wet radioactive waste volume. Even though there may be several potential solutions to wet waste volume reduction, a Root Cause Analysis should be performed to identify the solution that will be the most effective for volume reduction. The method described here provides for a logical sequence of determining root causes. Finally, the solution adopted must be evaluated after implementation to determine its effectiveness and verify that the root cause was addressed

  8. Equilibrating nanoparticle monolayers using wetting films.

    Science.gov (United States)

    Pontoni, Diego; Alvine, Kyle J; Checco, Antonio; Gang, Oleg; Ocko, Benjamin M; Pershan, Peter S

    2009-01-01

    Monolayers of bimodal gold nanoparticles on silicon are investigated by a combination of microscopy (dry monolayers) and x-ray diffraction (dry and wet monolayers). In the presence of an excess of small particles, the nanoscale packing structure closely resembles the small-particle-rich scenario of the structural crossover transition that has been predicted and also observed with micron-scale hard-sphere colloids. Structural morphology is monitored in situ during monolayer dissolution and reassembly within the thin liquid wetting film. This approach allows investigation of size and solvent effects on nanoparticles in quasi-two-dimensional confinement. PMID:19257214

  9. 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.

  10. Production of ceramics from coal fly ash

    Directory of Open Access Journals (Sweden)

    Angjusheva Biljana

    2012-01-01

    Full Text Available Dense ceramics are produced from fly ash from REK Bitola, Republic of Macedonia. Four types of fly ash from electro filters and one from the collected zone with particles < 0.063 mm were the subject of this research. Consolidation was achieved by pressing (P= 133 MPa and sintering (950, 1000, 1050 and 11000C and heating rates of 3 and 100/min. Densification was realized by liquid phase sintering and solid state reaction where diopside [Ca(Mg,Al(Si,Al2O6] was formed. Ceramics with optimal properties (porosity 2.96±0.5%, bending strength - 47.01±2 MPa, compressive strength - 170 ±5 MPa was produced at 1100ºC using the heating rate of 10ºC/min.

  11. Fundamental study of low-NOx combustion fly ash utilization

    International Nuclear Information System (INIS)

    This study is principally concerned with characterizing the organic part of coal combustion fly ashes. High carbon fly ashes are becoming more common as by-products of low-NOx combustion technology, and there is need to learn more about this fraction of the fly ash. The project team consists of two universities, Brown and Princeton, and an electrical utility, New England Power. A sample suite of over fifty fly ashes has been gathered from utilities across the United States, and includes ashes from a coals ranging in rank from bituminous to lignite. The characterizations of these ashes include standard tests (LOI, Foam Index), as well as more detailed characterizations of their surface areas, porosity, extractability and adsorption behavior. The ultimate goal is, by better characterizing the material, to enable broadening the range of applications for coal fly ash re-use beyond the current main market as a pozzolanic agent for concretes. The potential for high carbon-content fly ashes to substitute for activated carbons is receiving particular attention. The work performed to date has already revealed how very different the surfaces of different ashes produced by the same utility can be, with respect to polarity of the residual carbon. This can help explain the large variations in acceptability of these ashes as concrete additives

  12. Optical properties of volcanic ash: improving remote sensing observations.

    Science.gov (United States)

    Whelley, Patrick; Colarco, Peter; Aquila, Valentina; Krotkov, Nickolay; Bleacher, Jake; Garry, Brent; Young, Kelsey; Rocha Lima, Adriana; Martins, Vanderlei; Carn, Simon

    2016-04-01

    Many times each year explosive volcanic eruptions loft ash into the atmosphere. Global travel and trade rely on aircraft vulnerable to encounters with airborne ash. Volcanic ash advisory centers (VAACs) rely on dispersion forecasts and satellite data to issue timely warnings. To improve ash forecasts model developers and satellite data providers need realistic information about volcanic ash microphysical and optical properties. In anticipation of future large eruptions we can study smaller events to improve our remote sensing and modeling skills so when the next Pinatubo 1991 or larger eruption occurs, ash can confidently be tracked in a quantitative way. At distances >100km from their sources, drifting ash plumes, often above meteorological clouds, are not easily detected from conventional remote sensing platforms, save deriving their quantitative characteristics, such as mass density. Quantitative interpretation of these observations depends on a priori knowledge of the spectral optical properties of the ash in UV (>0.3μm) and TIR wavelengths (>10μm). Incorrect assumptions about the optical properties result in large errors in inferred column mass loading and size distribution, which misguide operational ash forecasts. Similarly, simulating ash properties in global climate models also requires some knowledge of optical properties to improve aerosol speciation.

  13. Application of solid ash based catalysts in heterogeneous catalysis.

    Science.gov (United States)

    Wang, Shaobin

    2008-10-01

    Solid wastes, fly ash, and bottom ash are generated from coal and biomass combustion. Fly ash is mainly composed of various metal oxides and possesses higher thermal stability. Utilization of fly ash for other industrial applications provides a cost-effective and environmentally friendly way of recycling this solid waste, significantly reducing its environmental effects. On the one hand, due to the higher stability of its major component, aluminosilicates, fly ash could be employed as catalyst support by impregnation of other active components for various reactions. On the other hand, other chemical compounds in fly ash such as Fe2O3 could also provide an active component making fly ash a catalyst for some reactions. In this paper, physicochemical properties of fly ash and its applications for heterogeneous catalysis as a catalyst support or catalyst in a variety of catalytic reactions were reviewed. Fly-ash-supported catalysts have shown good catalytic activities for H2 production, deSO(x), deNO(x), hydrocarbon oxidation,and hydrocracking, which are comparable to commercially used catalysts. As a catalyst itself, fly ash can also be effective for gas-phase oxidation of volatile organic compounds, aqueous-phase oxidation of organics, solid plastic pyrolysis, and solvent-free organic synthesis. PMID:18939526

  14. Durability of high volume fly ash concrete

    OpenAIRE

    Camões, Aires

    2006-01-01

    It is well known that the concrete industry has to contribute to the sustainability of construction. For this intent it is necessary to reduce the cement content without compromising the durability requirements of the concrete constructions. Therefore, large scale cement replacement in concrete by by products such as fly ash will be extremely beneficial from the overall ecological and environmental point of view. In this context, an experimental research work was carried out focused on the...

  15. Our silent enemy: ashes in our libraries

    OpenAIRE

    DeBakey, Lois; DeBakey, Selma

    1989-01-01

    Scholars, scientists, physicians, other health professionals, and librarians face a crucial decision today: shall we nourish the biomedical archives as a viable and indispensable source of information, or shall we bury their ashes and lose a century or more of consequential scientific history? Biomedical books and journals published since the 1850s on self-destructing acidic paper are silently and insidiously scorching on our shelves. The associated risks for scientists and physicians are ser...

  16. Thermal resistance of foamed fluidized bed ashes

    Czech Academy of Sciences Publication Activity Database

    Hanzlíček, Tomáš; Perná, Ivana

    2011-01-01

    Roč. 8, č. 2 (2011), s. 115-122. ISSN 1214-9705 R&D Projects: GA AV ČR IAA300460702 Institutional research plan: CEZ:AV0Z30460519 Keywords : thermal resistance * fluidized bed ash * XRD Subject RIV: DM - Solid Waste and Recycling Impact factor: 0.530, year: 2011 http://www.irsm.cas.cz/abstracts/AGG/02_11/2_Hanzlicek.pdf

  17. HHS 440 Ash Material- hhs440dotcom

    OpenAIRE

    VEERU2

    2015-01-01

    HHS 440 Week 1 DQ 1 Technology for Healthcare Professionals (Ash) For more course tutorials visit www.hhs440.com   Technology for Healthcare Professionals. Describe the reasons healthcare professionals need to be familiar with the most current computer hardware and software, networking, wireless technology, and to maintain a high level of computer literacy. § How will this aptitude assist you as a health and human service worker to provide client care that is mor...

  18. Mesoporous Silica from Rice Husk Ash

    OpenAIRE

    V.R. Shelke; S.S. Bhagade; S.A. Mandavgane

    2011-01-01

    Mesoporous silica is used as a raw material in several areas: in preparation of catalysts, in inks, as a concrete hardening accelerator, as a component of detergents and soaps, as a refractory constituent etc. Sodium silicate is produced by reacting rice hull ash (RHA) with aqueous NaOH and silica is precipitated from the sodium silicate by acidification. In the present work, conversion of about 90% of silica contained in RHA into sodium silicate was achieved in an open system at temperatures...

  19. Potential fly-ash utilization in agriculture: A global review

    Energy Technology Data Exchange (ETDEWEB)

    Basu, M.; Pande, M.; Bhadoria, P.B.S.; Mahapatra, S.C. [SGS India Private Ltd., Gurgaon (India). Agricultural Services

    2009-10-15

    Disposal of high amount of fly-ash from thermal power plants absorbs huge amount of water, energy and land area by ash ponds. In order to meet the growing energy demand, various environmental, economic and social problems associated with the disposal of fly-ash would continue to increase. Therefore, fly-ash management would remain a great concern of the century. Fly-ash has great potentiality in agriculture due to its efficacy in modification of soil health and crop performance. The high concentration of elements (K, Na, Zn, Ca, Mg and Fe) in fly-ash increases the yield of many agricultural crops. But compared to other sectors, the use of fly-ash in agriculture is limited. An exhaustive review of numerous studies of last four decades took place in this paper, which systematically covers the importance, scope and apprehension regarding utilization of fly-ash in agriculture. The authors concluded that though studies have established some solutions to handle the problems of radioactivity and heavy metal content in fly-ash, long-term confirmatory research and demonstration are necessary. This paper also identified some areas, like proper handling of dry ash in plants as well as in fields, ash pond management (i.e., faster decantation, recycling of water, vertical expansion rather than horizontal), monitoring of soil health, crop quality, and fate of fly-ash in time domain, where research thrust is required. Agricultural lime application contributes to global warming as Intergovernmental Panel on Climate Change (IPCC) assumes that all the carbon in agricultural lime is finally released as CO{sub 2} to the atmosphere. It is expected that use of fly-ash instead of lime in agriculture can reduce net CO{sub 2} emission, thus reduce global warming also.

  20. The dissolution of granulated wood ash in forest soils

    International Nuclear Information System (INIS)

    The purpose of this study was to examine the dissolution of granulated wood ash in forest soils. The study was based on comparison between ash granules collected from different forest sites and the original granules. The sites differed in drainage conditions and type of vegetation. The ash granules were spread 1 to 3 years before sampling. Three different types of ash granules were studied. One ash was granulated by adding molasses and lignosulfonate, the second by adding cement and the third by adding only water. The result of this study shows that the ash granulated with the water soluble binders molasses and lignosulfonate, was more easily dissolved than the other two granulated ashes. The former type of ash was almost totally dissolved after three years in moist environment and it had increased the pH level by 1.4 units in the humus layer of well drained sites. The ash granulated with cement did not influence the pH level in the humus layer during a two year period. The granules without any extra binders were almost as hard and insoluble as the granules with cement added. Independent of granulation method the soluble salts in the ash were quickly leached from the granules. This led to a decrease in the relative contents of K, Na, S and Cl during the time after spreading. In the ash granulated with water soluble binders, the relative alkalinity content and the relative contents of Ca and Mg decreased approximately by 20 % during the time after spreading. Corresponding figures for the other two ashes was only a few percent. During the time after spreading the relative contents of Al, Fe, P and the heavy metals Zn, Pb, Cr and Cd has increased, by approximately 30 %, in the ash granulated with water soluble binders. (25 refs., 5 figs., 13 tabs.)

  1. Investigation of the gypsum quality at three full-scale wet flue gas desulphurisation plants

    DEFF Research Database (Denmark)

    Hansen, Brian Brun; Kiil, Søren; Johnsson, Jan Erik

    2011-01-01

    In the present study the gypsum (CaSO4·2H2O) quality at three full-scale wet flue gas desulphurisation (FGD) plants and a pilot plant were examined and compared. Gypsum quality can be expressed in terms of moisture content (particle size and morphology dependent) and the concentration of residual...... limestone and other impurities. The particle size distributions (PSD) in the holding tanks of the investigated plants were similar, apart from a slightly higher fraction of small particles in the full-scale plants. These high levels of small particles could originate from nucleation, attrition or...... accumulation of fly ash and impurities from the sorbent. The crystal morphology obtained in the pilot plant was columnar with distinct crystal faces as opposed to the rounded shapes found at the full-scale plants. All the investigated full-scale plants consistently produced high quality gypsum (High purity...

  2. Aerodynamic characteristics of popcorn ash particles

    Energy Technology Data Exchange (ETDEWEB)

    Cherkaduvasala, V.; Murphy, D.W.; Ban, H.; Harrison, K.E.; Monroe, L.S. [University of Alabama, Birmingham, AL (United States). Dept. of Mechanical Engineering

    2007-07-01

    Popcorn ash particles are fragments of sintered coal fly ash masses that resemble popcorn in low apparent density. They can travel with the flow in the furnace and settle on key places such as catalyst surfaces. Computational fluid dynamics (CFD) models are often used in the design process to prevent the carryover and settling of these particles on catalysts. Particle size, density, and drag coefficient are the most important aerodynamic parameters needed in CFD modeling of particle flow. The objective of this study was to experimentally determine particle size, shape, apparent density, and drag characteristics for popcorn ash particles from a coal-fired power plant. Particle size and shape were characterized by digital photography in three orthogonal directions and by computer image analysis. Particle apparent density was determined by volume and mass measurements. Particle terminal velocities in three directions were measured in water and each particle was also weighed in air and in water. The experimental data were analyzed and models were developed for equivalent sphere and equivalent ellipsoid with apparent density and drag coefficient distributions. The method developed in this study can be used to characterize the aerodynamic properties of popcorn-like particles.

  3. Wettability alteration by trimeric cationic surfactant at water-wet/oil-wet mica mineral surfaces

    International Nuclear Information System (INIS)

    The wettability of oil reservoir rock affects the efficiency of the oil recovery process by reducing the capillary force. Methyldodecylbis [2-(dimethyldodecylammonio) ethyl] ammonium tribromide is a trimeric cationic surfactant that contains three dodecyl chains and three quaternary ammonium head groups connected by divinyl groups. The surfactant was synthesized, purified and used as a new wetting alteration agent. This paper focuses on the ability of this trimeric cationic surfactant to alter the wettability of water-wet and oil-wet mica mineral surfaces. The contact angle data of the solid-liquid interface in oil/water/solid three-phase system show that the trimeric cationic surfactant, when compared with single- and double-chain cationic surfactant, is a more effective wetting agent for water-wet and oil-wet mica surfaces at lower concentration. Measurements by atomic force microscopy (AFM) show that the surfactant molecules have formed a monolayer to reverse the wetting properties. On the water-wet surface, the surface is suffused with negative charge, which could attract the cationic head of surfactant, and leave the hydrophobic tails exposed. In contrast, on the oil-wet surface, the hydrophobic tails were attracted by hydrophobic interactions to the oil film between the surfactant and the crude oil. The hydrophilic heads were left outside to form a hydrophilic layer, which could explain the wettable to hydrophilic trend. Alteration to the degree of wettability is mainly dependent on the adsorption areas of the surfactant. The data show that the ability of the trimeric cationic surfactant affect the wettability is independent of surface tension.

  4. Turbulent flow over wetted and non-wetted superhydrophobic counterparts with random structure

    Science.gov (United States)

    Vajdi Hokmabad, B.; Ghaemi, S.

    2016-01-01

    The turbulent structure of a channel flow over a non-wetted superhydrophobic (SHO) surface is experimentally investigated at Re = 9600 (based on channel width) at the region of y+ > 10 within the buffer and logarithmic layers. The SHO surface has a random pattern produced by spray coating and is compared with a wetted counterpart and also a smooth surface. Two planar particle image velocimetry measurements are carried out in the streamwise/spanwise and streamwise/wall-normal planes. The vector fields are obtained from both ensemble averaging and individual cross-correlations of double-frame images. The results showed a small increase (˜5%) of the mean velocity profile at y+ = 10 over the non-wetted surface in comparison with the wetted and the smooth surfaces. Up to 15% reduction of normal and shear Reynolds stresses is observed in the inner layer over the non-wetted SHO surface. The wetted SHO counterpart demonstrates no effect on the mean velocity and Reynolds stresses in comparison with the smooth surface. The result confirms the comment of Gad-el-Hak ["Experimental study of skin friction drag reduction on superhydrophobic flat plates in high Reynolds number boundary layer flow," Phys. Fluids 25, 025103 (2013)] that the wetted SHO is hydrodynamically smooth if the surface pores are smaller than the viscous sublayer thickness. A noticeable suppression of the sweep and ejection events, increase of the spanwise spacing of the low and high speed streaks, and attenuation of vortical structures are observed over the non-wetted SHO. These indicate attenuation of the turbulence regeneration cycle due to the slip boundary condition over the non-wetted SHO surfaces with random texture.

  5. Quantitative determination of phases in the alkali activation of fly ash. Part I. Potential ash reactivity

    Energy Technology Data Exchange (ETDEWEB)

    A. Fernandez-Jimenez; A.G. de la Torre; A. Palomo; G. Lopez-Olmo; M.M. Alonso; M.A.G. Aranda [Eduardo Torroja Institute (CSIC), Madrid (Spain)

    2006-03-15

    The various (vitreous and crystalline) components of two type F fly ashes are quantified in this paper using three techniques: chemical analysis with selective solutions, X-ray powder diffraction combined with the Rietveld method and nuclear magnetic resonance. The findings confirm the suitability of the techniques to pursue the objectives while providing further insight into the chemical composition of the vitreous phase of the ash as well as an understanding of the thermal history of these materials. Finally, the paper corroborates the grounds established in prior research for regarding the glassy constituents of an ash to be instrumental in the control of its alkali reactivity during the manufacture of 'alkaline cements'. 24 refs., 9 figs., 4 tabs.

  6. Crowdsourcing genomic analyses of ash and ash dieback – power to the people

    Directory of Open Access Journals (Sweden)

    MacLean Dan

    2013-02-01

    Full Text Available Abstract Ash dieback is a devastating fungal disease of ash trees that has swept across Europe and recently reached the UK. This emergent pathogen has received little study in the past and its effect threatens to overwhelm the ash population. In response to this we have produced some initial genomics datasets and taken the unusual step of releasing them to the scientific community for analysis without first performing our own. In this manner we hope to ‘crowdsource’ analyses and bring the expertise of the community to bear on this problem as quickly as possible. Our data has been released through our website at oadb.tsl.ac.uk and a public GitHub repository.

  7. Two remarks on wetting and emulsions

    OpenAIRE

    de Gennes, Pierre-Gilles

    2000-01-01

    This paper is extracted from an opening address given at the workshop "Wetting: from microscopic origins to industrial applications" (Giens, May 6-12, 2000). It discusses two special points a) the nature of line energies for a contact line b) the aging of emulsions.

  8. Wet oxidation of a spacecraft model waste

    Science.gov (United States)

    Johnson, C. C.; Wydeven, T.

    1985-01-01

    Wet oxidation was used to oxidize a spacecraft model waste under different oxidation conditions. The variables studied were pressure, temperature, duration of oxidation, and the use of one homogeneous and three heterogeneous catalysts. Emphasis is placed on the final oxidation state of carbon and nitrogen since these are the two major components of the spacecraft model waste and two important plant nutrients.

  9. A literature review on wet deposition

    International Nuclear Information System (INIS)

    The literature on wet deposition or precipitation scavenging have been reviewed with special reference to predicting the radiological consequences of accidental contamination. The work was part of the EEC Radiation Protection Programme and done under a subcontract with Association Euratom-C.E.A. No. SC-014-BIAF-423-DK(SD). (author)

  10. Starch in the Wet-End

    Science.gov (United States)

    de Clerck, Peter

    Starch has been used in papermaking almost since the invention of paper. The global paper industry consumes almost 5 million tonnes of starch per year, making starch the third most important raw material in papermaking. Roughly 20% of this is used in the wet-end.

  11. 49 CFR 173.159 - Batteries, wet.

    Science.gov (United States)

    2010-10-01

    ... Batteries, wet. (a) Electric storage batteries, containing electrolyte acid or alkaline corrosive battery... (h) of this section and in §§ 173.220 and 173.222; and any battery or battery-powered device must be..., but not limited to: (i) Packaging each battery or each battery-powered device when practicable,...

  12. Characteristics of wetting temperature during spray cooling

    International Nuclear Information System (INIS)

    An experimental study has been done to elucidate the effects of mass flux and subcooling of liquid and thermal properties of solid on the wetting temperature during cooling of a hot block with spray. A water spray was impinged at one of the end surfaces of a cylindrical block initially heated at 400 or 500degC. The experimental condition was mass fluxes G=1-9 kg/m2 s and degrees of subcooling ΔTsub =20, 50, 80 K. Three blocks of copper, brass and carbon steel were prepared. During spray cooling internal block temperature distribution and sputtering sound pressure level were recorded and the surface temperature and heat flux were evaluated with 2D inverse heat conducting analysis. Cooling process on cooling curves is divided into four regimes categorized by change in a flow situation and the sound level. The wetting temperature defined as the wall temperature at a minimum heat flux point was measured over an extensive experimental range. The wetting wall temperature was correlated well with the parameter of GΔTsub. The wetting wall temperature increases as GΔTsub increases and reaches a constant value depending on the material of the surface at higher region of GΔTsub. (author)

  13. Verification of wet blasting decontamination technology

    International Nuclear Information System (INIS)

    Macoho Co., Ltd. participated in the projects of 'Decontamination Verification Test FY 2011 by the Ministry of the Environment' and 'Decontamination Verification Test FY 2011 by the Cabinet Office.' And we tested verification to use a wet blasting technology for decontamination of rubble and roads contaminated by the accident of Fukushima Daiichi Nuclear Power Plant of the Tokyo Electric Power Company. As a results of the verification test, the wet blasting decontamination technology showed that a decontamination rate became 60-80% for concrete paving, interlocking, dense-grated asphalt pavement when applied to the decontamination of the road. When it was applied to rubble decontamination, a decontamination rate was 50-60% for gravel and approximately 90% for concrete and wood. It was thought that Cs-134 and Cs-137 attached to the fine sludge scraped off from a decontamination object and the sludge was found to be separated from abrasives by wet cyclene classification: the activity concentration of the abrasives is 1/30 or less than the sludge. The result shows that the abrasives can be reused without problems when the wet blasting decontamination technology is used. (author)

  14. Rhizoctonia seed, seedling, and wet root rot

    Science.gov (United States)

    Wet root rot caused by Rhizoctonia solani Kühn can cause seed and seedling rot of both lentil and chickpea as well as many other agricultural crops worldwide. The pathogen is favored in cool, sandy soil with high organic matter under no-till or reduced-till soil management practices. Survival spor...

  15. Analysis of Altimeter Wet Troposphere Range Correction

    Institute of Scientific and Technical Information of China (English)

    纪永刚; 张杰; 姬光荣; 张有广

    2004-01-01

    Wet path delay caused by tropospheric water vapor must be considered before altimeter data are used in oceanic application. This paper analyzed several methods of atmosphere water range correction (AWRC) using Seasat, Geosat, TOPEX and ERS-1 data, especially the calculated delay path using brightness temperature of TMR on TOPEX and EMR on ERS-1; and discussed some other problems of AWRC.

  16. Desulfurization of flue gases by oil shale ash

    International Nuclear Information System (INIS)

    The possibility of using different ashes (furnace ash, cyclone ash) at the Estonian and Baltic Thermal Power Plants in recycle as a reagent for deeper desulfurization of flue gases and the ways of their activation (crushing, hydratation) were studied. The experiments were carried out in a derivatograph, a laboratory tube furnace and a fluidized bed kiln; different methods of analysis (chemical, X-ray, BET dynamic desorption, SEM, ion chromatography, etc.) were used. The optimum temperature interval for SO2 removal from the gas phase in the fluidized bed conditions for ashes without previous activation is 750-850 deg C and for hydrated ashes 550-850 deg C. The maximum SO2 removal efficiency up to 75% was achieved by using hydrated furnace ash, which means that the total SO2 removal efficiency increased accordingly, up to 95%. (author). 3 tabs., 5 figs., 9 refs

  17. Application of Fly Ash from Solid Fuel Combustion in Concrete

    DEFF Research Database (Denmark)

    Pedersen, Kim Hougaard

    2008-01-01

    in the feeding phase or during the combustion process, which gave rise to increased formation of soot. A low-NOx tangential fired 875 MWth power plant burning bituminous coal have been operated under extreme conditions in order to test the impact of the operating conditions on fly ash adsorption behavior and NOx......Application of Fly Ash from Solid Fuel Combustion in Concrete Kim H. Pedersen Abstract Industrial utilization of fly ash from pulverized coal combustion plays an important role in environmentally clean and cost effective power generation. Today, the primary market for fly ash utilization...... with implementation of low-NOx combustion technologies. The present thesis concerns three areas of importance within this field: 1) testing of fly ash adsorption behavior; 2) the influence of fuel type and combustion conditions on the ash adsorption behaviour including full-scale experiments at the power plant...

  18. Potential fly-ash utilization in agriculture: A global review

    Institute of Scientific and Technical Information of China (English)

    Manisha Basu; Manish Pande; P.B.S. Bhadoria; S.C. Mahapatra

    2009-01-01

    Though in last four decades various alternate energy sources have come into the limelight, the hyperbolic use of coal as a prime energy source cannot be counterbalanced. Disposal of high amount of fly-ash from thermal power plants absorbs huge amount of water, energy and land area by ash ponds. In order to meet the growing energy demand, various environmental, economic and social problems associated with the disposal of fly-ash would continue to increase. Therefore, fly-ash management would remain a great concern of the century. Fly-ash has great potentiality in agriculture due to its efficacy in modification of soil health and crop performance. The high concentration of elements (K, Na, Zn, Ca, Mg and Fe) in fly-ash increases the yield of many agricultural crops. But compared to other sectors, the use of fly-ash in agriculture is limited. An exhaustive review of numerous studies of last four decades took place in this paper, which systematically covers the importance, scope and apprehension regarding utilization of fly-ash in agriculture. The authors concluded that though studies have established some solutions to handle the problems of radioactivity and heavy metal content in flyash, long-term confirmatory research and demonstration are necessary. This paper also identified some areas, like proper handling of dry ash in plants as well as in fields, ash pond management (i.e., faster decantation, recycling of water, vertical expansion rather than horizontal), monitoring of soil health, crop quality, and fate of fly-ash in time domain, where research thrust is required. Agricultural lime application contributes to global warming as Intergovernmental Panel on Climate Change (IPCC) assumes that all the carbon in agricultural lime is finally released as CO2to the atmosphere. It is expected that use of fly-ash instead of lime in agriculture can reduce net CO2emission, thus reduce global warming also.

  19. Geoenvironmental aspects of coal refuse-fly ash blends

    OpenAIRE

    Albuquerque, Allwyn J.

    1994-01-01

    The separate land disposal of coal refuse and fly ash presents difficulties throughout the Appalachian region, both in terms of disposal costs per acre and in terms of its potential environmental impacts on soil, ground water, revegetation, and slope stability. The purpose of this study was to determine how fly ash addition to coal refuse would impact on certain geotechnical properties of the refuse disposal piles, and whether the refuse-fly ash blends would be suitable as co-d...

  20. Recovering germanium from coal ash by chlorination with ammonium chloride

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new process of enriching germanium from coal ash was developed. The process involves in mixing the coal ash and ammonium chloride and then roasting the mixture to produce germanium chloride that is then absorbed by dilute hydrochloric acid and hydrolyzed to germanium oxide. The germanium recovery reached to 80.2% at the optimum condition: mass ratio of NH4Cl/coal ash is 0.15, roasting temperature 400℃ and roasting time 90 min.

  1. Electrodialytic removal of Cd from biomass combustion fly ash suspensions

    DEFF Research Database (Denmark)

    Kirkelund, Gunvor M.; Ottosen, Lisbeth M.; Damoe, Anne J.

    2013-01-01

    the final Cd concentration was below 2.0. mg Cd/kg DM in at least one experiment done with each ash. This was obtained within 2 weeks of remediation and at liquid to solid (L/S) ratios of L/S 16 for the pre-washed straw ash and L/S 8 for the straw, co-firing and wood ash. © 2013 Elsevier B.V....

  2. Sorption of microquantities of scandium from ash dumps

    International Nuclear Information System (INIS)

    The extraction of scandium from ash-slug wastes is studied. Three variants of ion-exchange technology for the treatment are studied and elaborated on a bench scale. The aspects include leaching, loading capacity, kinetics and elution of scandium with the ampholyte resine AFI-21. The 98% recovery of scandium from liquid phase of pulp resulting by sulfuric acid leaching of ashes is obtained. The concentration of scandium in the precipitated crude concentrate is four thousand times higher than that in ashes

  3. Corrosion of Modified Concrete with Sugar Cane Bagasse Ash

    OpenAIRE

    Núñez-Jaquez, R. E.; J. E. Buelna-Rodríguez; C. P. Barrios-Durstewitz; Gaona-Tiburcio, C.; Almeraya-Calderón, F.

    2012-01-01

    Concrete is a porous material and the ingress of water, oxygen, and aggressive ions, such as chlorides, can cause the passive layer on reinforced steel to break down. Additives, such as fly ash, microsilica, rice husk ash, and cane sugar bagasse ash, have a size breakdown that allows the reduction of concrete pore size and, consequently, may reduce the corrosion process. The objective of this work is to determine the corrosion rate of steel in reinforced concrete by the addition of 20% sugar ...

  4. Satellite data assimilation to improve forecasts of volcanic ash concentrations

    OpenAIRE

    Fu, Guangliang; Lin, Hai-Xiang; Heemink, Arnold; SEGERS Arjo; Prata, Fred; Lu, Sha

    2016-01-01

    Data assimilation is a powerful tool that requires available observations to improve model forecast accuracy. Infrared satellite measurements of volcanic ash mass loadings are often used as input observations into the assimilation scheme. However, these satellite-retrieved data are often two-dimensional (2D), and cannot be easily combined with a three-dimensional (3D) volcanic ash model to continuously improve the volcanic ash state in a data assimilation system. By integrating available data...

  5. Ash chemistry and sintering, verification of the mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Hupa, M.; Skrifvars, B.J. [Aabo Akademi, Turku (Finland)

    1996-12-01

    In this project four sintering mechanisms have been studied, i.e., partial melting with a viscous liquid, partial melting with a non-viscous liquid, chemical reaction sintering and solid state sintering. The work has aimed at improving the understanding of ash sintering mechanisms and quantifying their role in combustion and gasification. The work has been oriented in particular on the understanding of biomass ash behavior. The work has not directly focused on any specific technical application. However, results can also be applied on other fuels such as brown coal, petroleum coke, black liquor and different types of wastes (PDF, RDF, MSW). In one part of study the melting behavior was calculated for ten biomass ashes and compared with lab measurements of sintering tendencies. The comparison showed that the T{sub 15} temperatures, i.e. those temperatures at which the ashes contained 15 % molten phase, correlated fairly well with the temperature at which the sintering measurements detected sintering. This suggests that partial melting can be predicted fairly accurate for some ashes already with the today existing thermodynamic calculation routines. In some cases, however the melting calculations did not correlate with the detected sintering temperatures. In a second part detailed measurements on ash behavior was conducted both in a semi full scale CFB and a lab scale FBC. Ashes and deposits were collected and analyzed in several different ways. These analyses show that the ash chemistry shifts radically when the fuel is shifted. Fuels with silicate based ashes behaved totally different than those with an oxide or salt based ash. The chemistry was also affected by fuel blending. The ultimate goal has been to be able to predict the ash thermal behavior during biomass thermal conversion, using the fuel and ash elemental analyses and a few operational key parameters as the only input data. This goal has not yet today been achieved. (author)

  6. Ash accumulation effects using bench marked 0-D model

    International Nuclear Information System (INIS)

    Ash accumulation is a key issue relative to our ability to achieve D-3He ARIES III burn conditions. 1-1/2-d transport simulations using the BALDUR code have been used to examine the correlation between the global ash particle confinement time and the edge exhaust (or recycling) efficiency. This provides a way to benchmark the widely used 0-D model. The burn conditions for an ARIES-III plasma with various ash edge recycling coefficients are examined

  7. Bioaccumulation of selenium from coal fly ash and associated environmental hazards in a freshwater fish community

    International Nuclear Information System (INIS)

    Bioaccumulation of Se by fish from Pigeon River and Pigeon Lake, Michigan, which receive inputs of Se from a coal fly-ash disposal facility, was studied to assess potential hazards of Se toxicity to fish and wildlife. Se concentrations in fish from sites receiving Se inputs from fly ash disposal ponds were significantly greater than concentrations in fish from upstream sites, which were near normal background concentrations. Se bioaccumulation differed substantially among fish species, especially in the most contaminated site, where whole-body Se concentrations for the five species analyzed ranged from 1.4 to 3.8 microg/g (wet wt.). The top predator in the community, northern pike (Esox lucius), had Se concentrations less than those in likely prey species. Among lower-order consumers, Se concentrations were greater in limnetic species (spottail shiner, Notropis hudsonius, and yellow perch, Perca flavescens), than in benthic species (white sucker, Catostomus commersoni, and rock bass, Ambloplites rupestris). Se concentrations in tissues of fish from the lower Pigeon River and Pigeon Lake approached, but did not exceed lowest observable effect concentrations (LOAECs) for Se in tissues of sensitive fish species. However, Se concentrations in several fish species exceeded LOAECs for dietary Se exposure of sensitive species of birds and mammals, suggesting that consumption of fish in these areas may pose a hazard to piscivorous wildlife

  8. Stepwise approach to establishing an ophthalmology wet laboratory.

    Science.gov (United States)

    Henderson, Bonnie An; Grimes, Kelly J; Fintelmann, Robert E; Oetting, Thomas A

    2009-06-01

    Wet laboratories (wet labs) play an increasingly important role in ophthalmology surgical residency training. We summarize the necessary components in establishing and maintaining a well-functioning wet lab and offer a stepwise guide for educators to improve the quality of the wet lab experience. We present 6 key factors in creating an ophthalmology wet lab; that is, setting up the physical space, establishing appropriate faculty and curriculum, obtaining the practice eye, stabilizing the eye, preparing the eye, and funding the wet lab. PMID:19465299

  9. Lead isotopic compositions of ash sourced from Australian bushfires

    International Nuclear Information System (INIS)

    This study identifies natural and industrial lead remobilized in ash deposits from three bushfires in relatively pristine areas of Australia in 2011 using lead isotopic compositions (208Pb/207Pb; 206Pb/207Pb). Lead concentrations in the ash ranged from 1 to 36 mg/kg, bracketing the range of lead (4–23 mg/kg) in surface soils (0–2 cm), subsurface (40–50 cm) soils and rocks. The lead isotopic compositions of ash and surface soil samples were compared to subsurface soils and local bedrock samples. The data show that many of the ash and surface soil lead isotopic compositions were a mixture of natural lead and legacy industrial lead depositions (such as leaded petrol combustion). However, some of the ash samples at each of the sites had lead isotopic compositions that did not fit a simple two end-member mixing model, indicating other, unidentified sources. - Highlights: • Lead isotopic compositions of ash deposits from wildfires in Australia were measured. • Not all ash lead isotopic compositions matched those of local soil and rock. • Ash lead was sourced from a mixture of natural and industrial sources. • The major industrial source was identified as depositions from historic leaded petrol. - This study shows that industrial lead is remobilized from large old trees in ash deposits following wildfires

  10. Effect of refractory agent on ash fusibility temperatures of briquette

    Institute of Scientific and Technical Information of China (English)

    Guo-xing CUI; Kui HUANG; Ming-sui LIN

    2013-01-01

    To solve the problem of the low ash fusion point of briquette,this paper reported that the ash fusibility temperatures can be elevated by changing ash ingredients through blending refractory agents in briquette ash,which will create favorable conditions for moving bed continuous gasification of briquette with oxygen-rich air.The effects of Al2O3,SiO2,kaolin,dry powder and bentonite on ash fusibility temperatures were studied,based upon the relationship between briquette ash components and ash fusibility.The results show that the increasing of ash fusibility temperatures by adding the same amount (11%,w)of refractory agents follows the sequence of SiO2,bentonite,dry powder,kaolin,Al2O3,with the softening temperatures beingelevated by 37.2,57.6,60.4,82.6 and 104.4 ℃.With the same ratio of SiO2/Al2O3 in briquette,adding the Al2O3 component is more effective than SiO2 for raising ash fusibility temperatures.In this paper,inexpensive kaolin and bentonite rich in Al2O3 are found to be better refractory agents,and the suitable adding quantities are 9% and 11%,respectively.

  11. The Cement Solidification of Municipal Solid Waste Incineration Fly Ash

    Institute of Scientific and Technical Information of China (English)

    HOU Haobo; HE Xinghua; ZHU Shujing; ZHANG Dajie

    2006-01-01

    The chemical composition, the content and the leachability of heavy metals in municipal solid waste incineration ( MSWI) fly ash were tested and analyzed. It is shown that the leachability of Pb and Cr exceeds the leaching toxicity standard, and so the MSWI fly ash is considered as hazardous waste and must be solidifled. The effect of solidifying the MSWI fly ash by cement was studied, and it is indicated that the heavy metals can be well immobilized if the mass fraction of the fly ash is appropriate. The heavy metals were immobilized within cement hydration products through either physical fixation, substitution, deposition or adsorption mechanisms.

  12. Multitechnique multielemental analysis of coal and fly ash

    International Nuclear Information System (INIS)

    The coal sample is first ashed with high temperature ashing or with RF plasma low temperature ashing. The coal ash or fly ash can be analyzed for major ash elements by fusing with lithium tetraborate in an automatic fusion device, the Claisse Fluxer. The ash samples are also dissolved in a Parr bomb in a mixture of aqua regia and HF. Subsequently, the solutions are analyzed for eight major (Al, Ca, Fe, K, Mg, Na, Si, and Ti) and 20 trace elements (As, B, Ba, Be, Cd, Co, Cr, Cu, Li, Mn, Mo, Ni, P, Pb, Sb, Se, Sr, U, V, and Zn) by inductively coupled plasma emission spectroscopy. Mercury in coal and fly ash is determined on a separate aliquot by the cold vapor atomic absorption technique. Fluorine and chlorine in the samples are determined by fusing with Na2CO3 and Eschka mixture, respectively, and then measuring the two ions in solution with specific ion electrodes. Oxygen in the samples can be determined rapidly and nondestructively by 14-MeV neutron activation analysis. These methods have been tested by analyzing several NBS coal and fly ash standards with good accuracy and reproducibility. 10 tables

  13. Environmental hazard of oil shale combustion fly ash.

    Science.gov (United States)

    Blinova, Irina; Bityukova, Liidia; Kasemets, Kaja; Ivask, Angela; Käkinen, Aleksandr; Kurvet, Imbi; Bondarenko, Olesja; Kanarbik, Liina; Sihtmäe, Mariliis; Aruoja, Villem; Schvede, Hedi; Kahru, Anne

    2012-08-30

    The combined chemical and ecotoxicological characterization of oil shale combustion fly ash was performed. Ash was sampled from the most distant point of the ash-separation systems of the Balti and Eesti Thermal Power Plants in North-Eastern Estonia. The fly ash proved potentially hazardous for tested aquatic organisms and high alkalinity of the leachates (pH>10) is apparently the key factor determining its toxicity. The leachates were not genotoxic in the Ames assay. Also, the analysis showed that despite long-term intensive oil-shale combustion accompanied by considerable fly ash emissions has not led to significant soil contamination by hazardous trace elements in North-Eastern Estonia. Comparative study of the fly ash originating from the 'new' circulating fluidized bed (CFB) combustion technology and the 'old' pulverized-fired (PF) one showed that CFB fly ash was less toxic than PF fly ash. Thus, complete transfer to the 'new' technology will reduce (i) atmospheric emission of hazardous trace elements and (ii) fly ash toxicity to aquatic organisms as compared with the 'old' technology. PMID:22717068

  14. Assessing fly ash treatment: Remediation and stabilization of heavy metals

    KAUST Repository

    Lima, A.T.

    2010-12-17

    Fly ashes from Municipal Solid Waste (MSW), straw (ST) and co-combustion of wood (CW) are here analyzed with the intent of reusing them. Two techniques are assessed, a remediation technique and a solidification/stabilization one. The removal of heavy metals from fly ashes through the electrodialytic process (EDR) has been tried out before. The goal of removing heavy metals has always been the reuse of fly ash, for instance in agricultural fields (BEK). The best removal rates are here summarized and some new results have been added. MSW fly ashes are still too hazardous after treatment to even consider application to the soil. ST ash is the only residue that gets concentrations low enough to be reused, but its fertilizing value might be questioned. An alternative reuse for the three ashes is here preliminary tested, the combination of fly ash with mortar. Fly ashes have been substituted by cement fraction or aggregate fraction. Surprisingly, better compressive strengths were obtained by replacing the aggregate fraction. CW ashes presented promising results for the substitution of aggregate in mortar and possibly in concrete. © 2010 Elsevier Ltd.

  15. Heavy metal characterization of circulating fluidized bed derived biomass ash.

    Science.gov (United States)

    Li, Lianming; Yu, Chunjiang; Bai, Jisong; Wang, Qinhui; Luo, Zhongyang

    2012-09-30

    Although the direct combustion of biomass for energy that applies circulating fluidized bed (CFB) technology is steadily expanding worldwide, only few studies have conducted an environmental assessment of biomass ash thus far. Therefore, this study aims to integrate information on the environmental effects of biomass ash. We investigated the concentration of heavy metal in biomass ash samples (bottom ash, cyclone ash, and filter ash) derived from a CFB boiler that combusted agricultural and forest residues at a biomass power plant (2×12 MW) in China. Ash samples were gathered for the digestion and leaching test. The heavy metal content in the solution and the leachate was studied via an inductively coupled plasma-mass spectrometer and a Malvern Mastersizer 2000 mercury analyzer. Measurements for the chemical composition, particle size distribution, and the surface morphology were carried out. Most of the metals in cyclone ash particles were enriched, whereas Ti and Hg were enriched in filter ash. Residence time contributed most to heavy metal enrichment. Under HJ/T 300 conditions, the heavy metals showed serious leaching characteristics. Under EN 12457-2 conditions, leaching behavior was hardly detected. PMID:22840499

  16. Biofuel Combustion Fly Ash Influence on the Properties of Concrete

    OpenAIRE

    Aurelijus Daugėla; Džigita Nagrockienė; Laurynas Zarauskas

    2016-01-01

    Cement as the binding agent in the production of concrete can be replaced with active mineral admixtures. Biofuel combustion fly ash is one of such admixtures. Materials used for the study: Portland cement CEM I 42.5 R, sand of 0/4 fraction, gravel of 4/16 fraction, biofuel fly ash, superplasticizer, water. Six compositions of concrete were designed by replacing 0%, 5%, 10%, 15% 20%, and 25% of cement with biofuel fly ash. The article analyses the effect of biofuel fly ash content on the prop...

  17. Wildfire Ash: Chemical Composition, Ash-Soil Interactions and Environmental Impacts

    Science.gov (United States)

    Brook, Anna; Hamzi, Seham; Wittenberg, Lea

    2015-04-01

    Of the five classical factors of soil formation, climate, parent material, topography, time, organisms, and recently recognized human activity, it is the latter factor which discretely includes fire and post-burn impact. However, it is considered that soil undergoing fire just experience a temporary removal of the top organic horizon, thus slightly modified and often labeled as 'temporarily disturbed' soil or soil 'under restoration/rehabilitation'. In fact the suggested seventh factor, post-burned produced ash, can act both dependently and independently of the other soil forming factors (Levin et al., 2013; Certini 2013). They are interdependent in cases where ash influences occur on time scales similar to 'natural' soil formation (Keesstra et ai., 2014) such as changes in vegetation. On the other hand, in post-fire areas a strong dependency is expected between soil-water retention mechanism, climate and topography. Wild-land fires exert many changes on the physical, chemical, mineralogical, biological, and morphological properties of soil that, in turn, affect the soil's hydrology and nutrient flux, modifying its ability to support vegetation and resist erosion. The ash produced by forest fires is a complex mixture composed of organic and inorganic particles characterized by vary physical-chemical and morphological properties. The importance of this study is straightforwardly related to the frequency and large-scales wildfires in Mediterranean region. In fact, wildfires are major environmental and land management concern in the world, where the number and severity of wildfires has increased during the past decades (Bodi, 2013). Certini (2013) assumed that cumulatively all of the vegetated land is burned in about 31 years annually affecting 330-430 Mha (over 3% of the Earth's surface) and wide range of land cover types worldwide including forests, peatlands, shrublands and grasslands. Whereas, the fire is identified as an important factor in soil formation, the

  18. Wet adhesion and adhesive locomotion of snails on anti-adhesive non-wetting surfaces.

    Directory of Open Access Journals (Sweden)

    Neil J Shirtcliffe

    Full Text Available Creating surfaces capable of resisting liquid-mediated adhesion is extremely difficult due to the strong capillary forces that exist between surfaces. Land snails use this to adhere to and traverse across almost any type of solid surface of any orientation (horizontal, vertical or inverted, texture (smooth, rough or granular or wetting property (hydrophilic or hydrophobic via a layer of mucus. However, the wetting properties that enable snails to generate strong temporary attachment and the effectiveness of this adhesive locomotion on modern super-slippy superhydrophobic surfaces are unclear. Here we report that snail adhesion overcomes a wide range of these microscale and nanoscale topographically structured non-stick surfaces. For the one surface which we found to be snail resistant, we show that the effect is correlated with the wetting response of the surface to a weak surfactant. Our results elucidate some critical wetting factors for the design of anti-adhesive and bio-adhesion resistant surfaces.

  19. Wet Adhesion and Adhesive Locomotion of Snails on Anti-Adhesive Non-Wetting Surfaces

    Science.gov (United States)

    Shirtcliffe, Neil J.; McHale, Glen; Newton, Michael I.

    2012-01-01

    Creating surfaces capable of resisting liquid-mediated adhesion is extremely difficult due to the strong capillary forces that exist between surfaces. Land snails use this to adhere to and traverse across almost any type of solid surface of any orientation (horizontal, vertical or inverted), texture (smooth, rough or granular) or wetting property (hydrophilic or hydrophobic) via a layer of mucus. However, the wetting properties that enable snails to generate strong temporary attachment and the effectiveness of this adhesive locomotion on modern super-slippy superhydrophobic surfaces are unclear. Here we report that snail adhesion overcomes a wide range of these microscale and nanoscale topographically structured non-stick surfaces. For the one surface which we found to be snail resistant, we show that the effect is correlated with the wetting response of the surface to a weak surfactant. Our results elucidate some critical wetting factors for the design of anti-adhesive and bio-adhesion resistant surfaces. PMID:22693563

  20. Elemental characterization of coal, fly ash, and bottom ash using an energy dispersive X-ray fluorescence technique

    International Nuclear Information System (INIS)

    A total of 18 elements viz. Si, Al, Fe, Ca, Mg, K, Na, Sr, V, Zn, Mn, Cr, Cu, Pb, Ni, Co, As and Cd were analyzed in coal, fly ash and bottom ash samples collected across India using an EDXRF technique. Various indices such as element enrichment ratio, enrichment factor (with respect to crustal average) and mineral composition were calculated. Around 95% of mass was reconstructed using the concentration of elements in this study for fly and bottom ash. - Highlights: • Concentrations of 18 elements were determined in coal and ash samples using EDXRF. • Mineral quantification up to 95% was carried out for fly and bottom ash samples. • Enrichment ratios of elements were calculated in combustion residue with respect to coal. • Enrichment factor with respect to crustal average was estimated for ash samples

  1. Wet Adhesion and Adhesive Locomotion of Snails on Anti-Adhesive Non-Wetting Surfaces

    OpenAIRE

    Shirtcliffe, Neil; McHale, Glen; Newton, Michael

    2012-01-01

    Creating surfaces capable of resisting liquid-mediated adhesion is extremely difficult due to the strong capillary forces that exist between surfaces. Land snails use this to adhere to and traverse across almost any type of solid surface of any orientation (horizontal, vertical or inverted), texture (smooth, rough or granular) or wetting property (hydrophilic or hydrophobic) via a layer of mucus. However, the wetting properties that enable snails to generate strong temporary attachment and th...

  2. Effects of water availability on emerald ash borer larval performance and phloem phenolics of Manchurian and black ash.

    Science.gov (United States)

    Chakraborty, Sourav; Whitehill, Justin G A; Hill, Amy L; Opiyo, Stephen O; Cipollini, Don; Herms, Daniel A; Bonello, Pierluigi

    2014-04-01

    The invasive emerald ash borer (EAB) beetle is a significant threat to the survival of North American ash. In previous work, we identified putative biochemical and molecular markers of constitutive EAB resistance in Manchurian ash, an Asian species co-evolved with EAB. Here, we employed high-throughput high-performance liquid chromatography with photodiode array detection and mass spectrometry (HPLC-PDA-MS) to characterize the induced response of soluble phloem phenolics to EAB attack in resistant Manchurian and susceptible black ash under conditions of either normal or low water availability, and the effects of water availability on larval performance. Total larval mass per tree was lower in Manchurian than in black ash. Low water increased larval numbers and mean larval mass overall, but more so in Manchurian ash. Low water did not affect levels of phenolics in either host species, but six phenolics decreased in response to EAB. In both ashes, pinoresinol A was induced by EAB, especially in Manchurian ash. Pinoresinol A and pinoresinol B were negatively correlated with each other in both species. The higher accumulation of pinoresinol A in Manchurian ash after attack may help explain the resistance of this species to EAB, but none of the responses measured here could explain increased larval performance in trees subjected to low water availability. PMID:24125060

  3. Illinois basin coal fly ashes. 2. Equilibria relationships and qualitative modeling of ash-water reactions

    Science.gov (United States)

    Roy, W.R.; Griffin, R.A.

    1984-01-01

    Alkaline and acidic Illinois Basin coal fly ash samples were each mixed with deionized water and equilibrated for about 140 days to simulate ash ponding environments. Common to both equilibrated solutions, anhydrite solubility dominated Ca2+ activities, and Al3+ activities were in equilibrium with both matrix mullite and insoluble aluminum hydroxide phases. Aqueous silica activities were controlled by both mullite and matrix silicates. The pH of the extract of the acidic fly ash was 4.1 after 24 h but increased to a pH value of 6.4 as the H2SO4, assumed to be adsorbed to the particle surfaces, was exhausted by the dissolution of matrix iron oxides and aluminosilicates. The activities of aqueous Al3+ and iron, initially at high levels during the early stages of equilibration, decreased to below analytical detection limits as the result of the formation of insoluble Fe and Al hydroxide phases. The pH of the extract of the alkaline fly ash remained above a pH value of 10 during the entire equilibration interval as a result of the hydrolysis of matrix oxides. As with the acidic system, Al3+ activities were controlled by amorphous aluminum hydroxide phases that began to form after about 7 days of equilibration. The proposed mechanisms and their interrelations are discussed in addition to the solubility diagrams used to deduce these relationships. ?? 1984 American Chemical Society.

  4. Spectral analysis of white ash response to emerald ash borer infestations

    Science.gov (United States)

    Calandra, Laura

    The emerald ash borer (EAB) (Agrilus planipennis Fairmaire) is an invasive insect that has killed over 50 million ash trees in the US. The goal of this research was to establish a method to identify ash trees infested with EAB using remote sensing techniques at the leaf-level and tree crown level. First, a field-based study at the leaf-level used the range of spectral bands from the WorldView-2 sensor to determine if there was a significant difference between EAB-infested white ash (Fraxinus americana) and healthy leaves. Binary logistic regression models were developed using individual and combinations of wavelengths; the most successful model included 545 and 950 nm bands. The second half of this research employed imagery to identify healthy and EAB-infested trees, comparing pixel- and object-based methods by applying an unsupervised classification approach and a tree crown delineation algorithm, respectively. The pixel-based models attained the highest overall accuracies.

  5. Production of Smokeless Briquette Charcoals from Wet Cake Waste of Ethanol Industry

    Directory of Open Access Journals (Sweden)

    Walairat Uttamaprakrom

    2012-04-01

    Full Text Available The main aim of this research was to investigate proximate analysis and heating value of wet cake waste from ethanol industry to be used as alternative fuels by carbonization at 400, 450, 500 and 550 degrees, vary times 30, 45, 60 and 90 minutes in oxygen-limited conditions. The maximum yields and fixed carbon volume were observed to be evolving at 500c, 60 minutes. At condition has 1.17% moisture, 34.42% ash, 16.57% volatile matter and 47.84% fixed carbon respectively.Then bring wet cake waste to briquette charcoals by hot and cold compressed for utilization in industry and commercial. Found that heating value of hot and cold compressed were 20,257.25 KJ/kg and 24,790.21 KJ/kg,which are higher heating value after carbonization.There are also cost-benefit and cost-effectiveness analysis, hot compressed cost 0.17 baht/piece, total production at breakeven 704,225 pieces and payback period of 0.18 years, while cold compressed cost 0.3175 baht/piece, total production at breakeven 341,297 pieces and payback period of 0.17 years.

  6. Reactive leaching of recovery boiler fly ash

    OpenAIRE

    Frigård, Antti

    2016-01-01

    This thesis studied a new CaO leaching method for chloride and potassium removal from recovery boiler fly ash. The concept of this method is to use calcium oxide (or calcium hydroxide) as an additive in the leaching stage in order to ease the subsequent solid-liquid separation. CaO leaching has several benefits over traditional leaching process which uses sulphuric acid as an additive: CaO does not include sulphur that would affect the mills sulphur sodium balance, CaO is readily available in...

  7. ASH ENG 125 / Assignmentcloud.com

    OpenAIRE

    admin

    2015-01-01

    ENG 125 Complete Class   Check this A+ Guidelines at   http://www.assignmentcloud.com/ENG-125-ASH/ENG-125-Complete-Class-Guide     For more classes visit www.assignmentcloud.com ENG 125 Complete Class ENG 125 Week 1 DQ 1 ENG 125 Week 1 DQ 2 ENG 125 Week 1 Reading Assignment ENG 125 Week 2 DQ 1 ENG 125 Week 2 DQ 2 ENG 125 Week 2 Important Elements of Narratives Assignment ENG 125 Week 3 DQ 1 ENG 125 Week 3 DQ ...

  8. On the visibility of airborne volcanic ash and mineral dust

    Science.gov (United States)

    Weinzierl, B.; Sauer, D. N.; Minikin, A.; Reitebuch, O.; Dahlkötter, F.; Mayer, B. C.; Emde, C.; Tegen, I.; Gasteiger, J.; Petzold, A.; Veira, A.; Kueppers, U.; Schumann, U.

    2012-12-01

    After the eruption of the Eyjafjalla volcano (Iceland) in April 2010 which caused the most extensive restrictions of the airspace over Europe since the end of World War II, the aviation safety concept of avoiding "visible ash", i.e. volcanic ash that can be seen by the human eye, was recommended. However so far, no clear definition of "visible ash" and no relation between the visibility of an aerosol layer and related aerosol mass concentrations are available. The goal of our study is to assess whether it is possible from the pilot's perspective in flight to detect the presence of volcanic ash and to distinguish between volcanic ash and other aerosol layers just by sight. In our presentation, we focus the comparison with other aerosols on aerosol types impacting aviation: Besides volcanic ash, dust storms are known to be avoided by aircraft. We use in-situ and lidar data as well photographs taken onboard the DLR research aircraft Falcon during the Saharan Mineral Dust Experiments (SAMUM) in 2006 and 2008 and during the Eyjafjalla volcanic eruption in April/May 2010. We complement this analysis with numerical modelling, using idealized radiative transfer simulations with the 3D Monte Carlo radiative transfer code MYSTIC for a variety of selected viewing geometries. Both aerosol types, Saharan mineral dust and volcanic ash, show an enhanced coarse mode (> 1 μm) aerosol concentration, but volcanic ash aerosol additionally contains a significant number of Aitken mode particles (perception, etc. In addition, the optical depth along the line of sight through an aerosol layer is more important than just the (vertical) optical depth, which is measured, for example, by sun photometers or satellites. The results of our study are in particular interesting for the question on the visibility of volcanic ash. Our analyses of "visible ash" demonstrate that under clear sky conditions volcanic ash is visible already at concentrations far below what is currently considered as the

  9. Experimental Investigation of Wetting with Magnetic Fluids.

    Science.gov (United States)

    Manukyan, Selin; Schneider, Marius

    2016-05-24

    Here we report the experimental results of the general wetting behavior of an oil-based ferrofluid and a water-based magnetic paint droplet on a hydrophobic surface under the effect of an external magnetic field. By increasing the magnetic field in the vertical direction, the height of the oil-based ferrofluid droplet increases while the width decreases; on the contrary, under the same circumstances, the height of the water-based magnetic paint droplet decreases whereas the width increases. The wetting behavior of the oil-based ferrofluid and the water-based magnetic paint droplets is evaluated as a function of the contact angle, contact line diameter, and hysteresis curve alterations. Conclusively, a general explanation is given for the contrary behavior of both liquids, and some application processes for future implementations are introduced. PMID:27119597

  10. Liquid holdup in wet-gas pipelines

    International Nuclear Information System (INIS)

    An experimental study of two-phase flow was conducted to investigate liquid holdup in wet-gas pipelines. The liquid-holdup data were obtained by passing spheres through a 1,333-ft [406.3-m] -long, 3.068-in. [77.93-mm] -ID horizontal pipe and measuring the liquid volumes removed. Three different two-phase mixtures were used. The holdup data were compared with predicted holdup values and were used to evaluate a mechanistic model for stratified flow. None of the methods could accuratly predict liquid holdup in this low-holdup region. Two new empirical liquid-holdup correlations for horizontal flow were proposed. The first is strictly for wet-gas pipelines (0< y/sub L/<0.35); the second is for any horizontal pipeline (0< y/sub L/<1.0)

  11. Wet precipitators for sulphuric acid plants

    International Nuclear Information System (INIS)

    Both the service requirements and design construction details have changed considerably in recent years for wet electrostatic precipitators as used for gas cleaning ahead of metallurgical sulphuric acid plants. Increased concern over acid quality has resulted in more emphasis on dust efficiencies compared to collection of acid mist. Also, higher static operating pressures have caused large structural loads on casing and internal components. In this paper these two issues are addressed in the following ways: Recognition that all dusts do not collect similarly. The mechanism by which various dusts collect affect the design of the entire wet gas cleaning system. Use of both traditional and newer materials of construction to accommodate the higher design pressures while still maintaining corrosion resistance

  12. Dry-Wet Fermentation for Biogas Production

    OpenAIRE

    Ahlhaus, M; Barz, M; Vogel, T.

    2008-01-01

    At present biogas plants produce biogas mainly from slurry by liquid fermentation. But the low substrate digestation of herbaceous biomass by liquid fermentation permits to use only a low amount of herbaceous biomass. Since April 2007 the collaborative project entitled “Development of a combined dry-wet fermentation process to produce biogas from herbaceous biomass substrates” is conducted at the Laboratory for Integrated Energy Systems of the University of Applied Sciences in ...

  13. Study of polycaprolactone wet electrospinning process

    OpenAIRE

    E. Kostakova; M. Seps; P. Pokorny; Lukas, D.

    2014-01-01

    Wet electrospinning is a useful method for 3-dimensional structure control of nanofibrous materials. This innovative technology uses a liquid collector instead of the metal one commonly used for standard electrospinning. The article compares the internal structural features of polycaprolactone (PCL) nanofibrous materials prepared by both technologies. We analyze the influence of different water/ethanol compositions used as a liquid collector on the morphology of the resultant polycaprolactone...

  14. Thermal Equilibrium and Wet Gas Compressor Performance

    OpenAIRE

    Aalvik, Marthe

    2011-01-01

    The wet gas performance model established for this master s thesis is based on results achieved from a single stage, low pressure ratio, centrifugal compressor set up at NTNU. Water droplets are injected to the flow right before the inlet. The GMF varies from 0.9 to 0.65 throughout the experiments preformed. Compressor performance is achieved by simulations in HYSYS with atmospheric inlet conditions. The importance of accurate measurements is evident to achieve the correct performance. A lite...

  15. Static wetting behaviour of diblock copolymers

    OpenAIRE

    Ausserre, D.; Raghunathan, V.; Maaloum, M.

    1993-01-01

    Thin liquid films of ordered diblock copolymers deposited on a solid substrate form a multilayer stacking parallel to the solid surface. A multilayer with a finite extend can be stable, metastable, or unstable, depending on the relative values of the surface energies of the various interfaces. The spreading parameter and chemical potential of a n-layer are derived, and used for classifying all possible situations. It is shown that only mono- and bilayers can be stable, and that non-wetting mu...

  16. The role of thin films in wetting

    OpenAIRE

    Marmur, Abraham

    1988-01-01

    The role of thin films in wetting is reviewed. Three modes of spontaneous spreading are discussed : incomplete spreading, complete spreading and mixed-mode spreading. A thin film can be either molecular or colloidal in thickness. Molecularly adsorbed films are mainly associated with incomplete spreading. Colloidal films usually extend from the bulk of the liquid in dynamic situations of complete spreading. Their existence at equilibriuim with the bulk depends on the orientation in the gravita...

  17. Sullivan model for wetting transition in closed system

    International Nuclear Information System (INIS)

    The wetting transition in a closed system is analytically discussed based on the Sullivan model. In order to have a wetting transition in the system the wall potential must have intermediate strength. The wetting transition is first order for the finite system, while it becomes of second order for the infinite one. In addition, the temperature TW of the wetting transition becomes lower as the separation of the two walls decreases. (author). 8 refs, 5 figs

  18. Hydrogen and helium films as model systems of wetting

    OpenAIRE

    Herminghaus, Stephan; Vorberg, Jens; Gau, Hartmut; Conradt, Robert N. J.; Reinelt, Dietmar; Ulmer, Holger; Leiderer, Paul; Przyrembel, Michael

    1997-01-01

    Optical experiments on the wetting properties of liquid 4He and molecular hydrogen are reviewed. Hydrogen films on noble metal surfaces serve as model systems for studying triple point wetting, a continuous transition between wetting and non-wetting. By means of optically excited surface plasmons, the adsorbed film thickness for temperatures around, and far below, the bulk melting temperature is measured, and the physical mechanisms responsible for the transition are elucidated. Possible appl...

  19. STUDY ON WET STRENGTH PERFORMANCE OF KENAF MULCH

    Institute of Scientific and Technical Information of China (English)

    Jinghui Zhou; Xinge Wu; Hongwei Zhu

    2004-01-01

    Optimum applied technical conditions of wet strength agent for kenaf mulch were studied in this article. Breaking length, wet-dry strength ratio, tear index and burst index of kenaf mulch were measured and optimum wet strength agent was selected. The aim is to make mulch have properties of heat preservation, humidity preservation, growth prompting, biodegradation and maximum wet strength and to improve impact resistance of mulch to rainwater so as to assure growth of plant and replace plastic film.

  20. Study of polycaprolactone wet electrospinning process

    Directory of Open Access Journals (Sweden)

    E. Kostakova

    2014-08-01

    Full Text Available Wet electrospinning is a useful method for 3-dimensional structure control of nanofibrous materials. This innovative technology uses a liquid collector instead of the metal one commonly used for standard electrospinning. The article compares the internal structural features of polycaprolactone (PCL nanofibrous materials prepared by both technologies. We analyze the influence of different water/ethanol compositions used as a liquid collector on the morphology of the resultant polycaprolactone nanofibrous materials. Scanning electron micro-photographs have revealed a bimodal structure in the wet electrospun materials composed of micro and nanofibers uniformly distributed across the sample bulk. We have shown that the full-faced, twofold fiber distribution is due to the solvent composition and is induced and enhanced by increasing the ethanol weight ratio. Moreover, the comparison of fibrous layers morphology obtained by wet and dry spinning have revealed that beads that frequently appeared in dry spun materials are created by Plateau-Rayleigh instability of the fraction of thicker fibers. Theoretical conditions for spontaneous and complete immersion of cylindrical fibers into a liquid collector are also derived here.

  1. Estimating soil wetness using satellite data

    Science.gov (United States)

    Choudhury, Bhaskar J.; Golus, Robert E.

    1988-01-01

    Improved estimates of soil wetness were obtained using observations from both the NIMBUS-7 Scanning Multichannel Microwave Radiometer (SMMR) and the NOAA-7 Advanced Very High Resolution Radiometer (AVHRR). SMMR 66 GHz frequency, horizontal polarization, brightness temperature T(BH) was first correlated with soil wetness, as computed using an Antecedent Precipitation Index (API) model, for a number of SMMR ground resolution areas involving a fairly wide range of vegetation densities. The API generally accounted for more than 70 percent of the observed temporal variability in T(BH), with linear correlations being significant at the 1 percent level. The regression slope of T(BH) versus API correlated well, at the 1 percent level, with a vegetation index derived from AVHRR visible and near-infrared observations. The regression intercept was found to correlate less satisfactorily, but was significant at the 5 percent level. These linear regression results were used to develop a diagnostic model for soil wetness using SMMR and AVHRR data only.

  2. Fundamental Difficulties Associated With Underwater Wet Welding

    Directory of Open Access Journals (Sweden)

    Joshua E. Omajene,

    2014-06-01

    Full Text Available The offshore industries carry out welding activities in the wet environment. It is evident that the wet environments possess difficulties in carrying out underwater welding. Therefore there is the need to improve the quality of weld achieved in underwater welding. This paper investigates the difficulties associated with underwater welding. The objective of this research paper is to identify and analyze the different difficulties in underwater welding so as to make a clear background for further research to identifying the processes of eliminating these difficulties. The major difficulties in underwater welding are the cooling rate of the weld metal and arc stability during underwater wet welding at a higher depth. Methods of decreasing the cooling rate of weld metal and how to achieve arc stability are the major methods of approach. The result of welds achieved in underwater welding will be much improved as compared to air welding if the effects of the difficulties associated with underwater welding are eliminated. This will lead to a more robust welding activities being carried out underwater.

  3. Wetting properties of molecularly rough surfaces

    International Nuclear Information System (INIS)

    We employ molecular dynamics simulations to study the wettability of nanoscale rough surfaces in systems governed by Lennard-Jones (LJ) interactions. We consider both smooth and molecularly rough planar surfaces. Solid substrates are modeled as a static collection of LJ particles arranged in a face-centered cubic lattice with the (100) surface exposed to the LJ fluid. Molecularly rough solid surfaces are prepared by removing several strips of LJ atoms from the external layers of the substrate, i.e., forming parallel nanogrooves on the surface. We vary the solid-fluid interactions to investigate strongly and weakly wettable surfaces. We determine the wetting properties by measuring the equilibrium droplet profiles that are in turn used to evaluate the contact angles. Macroscopic arguments, such as those leading to Wenzel’s law, suggest that surface roughness always amplifies the wetting properties of a lyophilic surface. However, our results indicate the opposite effect from roughness for microscopically corrugated surfaces, i.e., surface roughness deteriorates the substrate wettability. Adding the roughness to a strongly wettable surface shrinks the surface area wet with the liquid, and it either increases or only marginally affects the contact angle, depending on the degree of liquid adsorption into the nanogrooves. For a weakly wettable surface, the roughness changes the surface character from lyophilic to lyophobic due to a weakening of the solid-fluid interactions by the presence of the nanogrooves and the weaker adsorption of the liquid into the nanogrooves

  4. Estimating evaporation from a wet grassland

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available Wet grasslands are being restored across the UK and Europe to reinstate their high biodiversity following over 50 years of drainage and conversion to arable agriculture. The water balance of many wet grasslands is dominated by precipitation and evaporation and it is essential to quantify evaporation rates to understand the hydrological functioning of wetlands and the implications for water resources in catchments where wetlands are being restored. This paper considers data from direct measurements of evaporation from the Pevensey Levels wet grassland using the eddy correlation method. Equations are derived to predict actual evaporation using meteorological data on the site or from standard meteorological station observations. It was found that evaporation could be estimated reliably from meteorological variables, such as wind speed, temperature and humidity and by water availability. It was also found that when water availability is high, evaporation is high and may exceed reference evaporation values, raising questions over the deployment of the two-step Penman-Monteith model unless reliable crop coefficients and relative evaporation figures can be determined.

  5. Mercury Control for Plants Firing Texas Lignite and Equipped with ESP-wet FGD

    Energy Technology Data Exchange (ETDEWEB)

    Katherine Dombrowski

    2009-12-31

    This report presents the results of a multi-year test program conducted as part of Cooperative Agreement DE-FC26-06NT42779, 'Mercury Control for Plants Firing Texas Lignite and Equipped with ESP-wet FGD.' The objective of this program was to determine the level of mercury removal achievable using sorbent injection for a plant firing Texas lignite fuel and equipped with an ESP and wet FGD. The project was primarily funded by the U.S. DOE National Energy Technology Laboratory. EPRI, NRG Texas, Luminant (formerly TXU), and AEP were project co-funders. URS Group was the prime contractor, and Apogee Scientific and ADA-ES were subcontractors. The host site for this program was NRG Texas Limestone Electric Generating Station (LMS) Units 1 and 2, located in Jewett, Texas. The plant fires a blend of Texas lignite and Powder River Basin (PRB) coal. Full-scale tests were conducted to evaluate the mercury removal performance of powdered sorbents injected into the flue gas upstream of the ESP (traditional configuration), upstream of the air preheater, and/or between electric fields within the ESP (Toxecon{trademark} II configuration). Phases I through III of the test program, conducted on Unit 1 in 2006-2007, consisted of three short-term parametric test phases followed by a 60-day continuous operation test. Selected mercury sorbents were injected to treat one quarter of the flue gas (e.g., approximately 225 MW equivalence) produced by Limestone Unit 1. Six sorbents and three injection configurations were evaluated and results were used to select the best combination of sorbent (Norit Americas DARCO Hg-LH at 2 lb/Macf) and injection location (upstream of the ESP) for a two-month performance evaluation. A mercury removal rate of 50-70% was targeted for the long-term test. During this continuous-injection test, mercury removal performance and variability were evaluated as the plant operated under normal conditions. Additional evaluations were made to determine any

  6. 7 CFR 51.1563 - Soft rot or wet breakdown.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Soft rot or wet breakdown. 51.1563 Section 51.1563... STANDARDS) United States Standards for Grades of Potatoes 1 Definitions § 51.1563 Soft rot or wet breakdown. Soft rot or wet breakdown means any soft, mushy, or leaky condition of the tissue such as slimy...

  7. 7 CFR 51.1582 - Soft rot or wet breakdown.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Soft rot or wet breakdown. 51.1582 Section 51.1582... STANDARDS) United States Consumer Standards for Potatoes Definitions § 51.1582 Soft rot or wet breakdown. Soft rot or wet breakdown means any soft, mushy, or leaky condition of the tissue such as slimy...

  8. Characteristics of wet work in the cleaning industry

    NARCIS (Netherlands)

    Jungbauer, F H W; Van Der Harst, J J; Schuttelaar, M L; Groothoff, J W; Coenraads, P J

    2004-01-01

    Wet work is the main cause of occupational contact dermatitis in the cleaning industry. Dermatologists and occupational physicians need to base their primary and secondary prevention for workers in the cleaning industry on the characteristics of wet work exposures. We quantified the burden of wet wo

  9. Wetting of doped carbon nanotubes by water droplets

    DEFF Research Database (Denmark)

    Kotsalis, E. M.; Demosthenous, E.; Walther, Jens Honore;

    2005-01-01

    We study the wetting of doped single- and multi-walled carbon nanotubes by water droplets using molecular dynamics simulations. Chemisorbed hydrogen is considered as a model of surface impurities. We study systems with varying densities of surface impurities and we observe increased wetting, as c...... doping sites leading to enhanced wetting. (c) 2005 Elsevier B.V. All rights reserved....

  10. Effects of chemical composition of fly ash on efficiency of metal separation in ash-melting of municipal solid waste

    International Nuclear Information System (INIS)

    Highlights: ► Separation of Pb and Zn from Fe and Cu in ash-melting of municipal solid waste. ► Molar ratio of Cl to Na and K in fly ash affected the metal-separation efficiency. ► The low molar ratio and a non-oxidative atmosphere were better for the separation. - Abstract: In the process of metal separation by ash-melting, Fe and Cu in the incineration residue remain in the melting furnace as molten metal, whereas Pb and Zn in the residue are volatilized. This study investigated the effects of the chemical composition of incineration fly ash on the metal-separation efficiency of the ash-melting process. Incineration fly ash with different chemical compositions was melted with bottom ash in a lab-scale reactor, and the efficiency with which Pb and Zn were volatilized preventing the volatilization of Fe and Cu was evaluated. In addition, the behavior of these metals was simulated by thermodynamic equilibrium calculations. Depending on the exhaust gas treatment system used in the incinerator, the relationships among Na, K, and Cl concentrations in the incineration fly ash differed, which affected the efficiency of the metal separation. The amounts of Fe and Cu volatilized decreased by the decrease in the molar ratio of Cl to Na and K in the ash, promoting metal separation. The thermodynamic simulation predicted that the chlorination volatilization of Fe and Cu was prevented by the decrease in the molar ratio, as mentioned before. By melting incineration fly ash with the low molar ratio in a non-oxidative atmosphere, most of the Pb and Zn in the ash were volatilized leaving behind Fe and Cu

  11. Failure to phytosanitize ash firewood infested with emerald ash borer in a small dry kiln using ISPM-15 standards.

    Science.gov (United States)

    Goebel, P Charles; Bumgardner, Matthew S; Herms, Daniel A; Sabula, Andrew

    2010-06-01

    Although current USDA-APHIS standards suggest that a core temperature of 71.1 degrees C (160 degrees F) for 75 min is needed to adequately sanitize emerald ash borer, Agrilus planipennis Fairmaire-infested firewood, it is unclear whether more moderate (and economical) treatment regimes will adequately eradicate emerald ash borer larvae and prepupae from ash firewood. We constructed a small dry kiln in an effort to emulate the type of technology a small- to medium-sized firewood producer might use to examine whether treatments with lower temperature and time regimes successfully eliminate emerald ash borer from both spilt and roundwood firewood. Using white ash (Fraxinus americana L.) firewood collected from a stand with a heavy infestation of emerald ash borer in Delaware, OH, we treated the firewood using the following temperature and time regime: 46 degrees C (114.8 degrees F) for 30 min, 46 degrees C (114.8 degrees F) for 60 min, 56 degrees C (132.8 degrees F) for 30 min, and 56 degrees C (132.8 degrees F) for 60 min. Temperatures were recorded for the outer 2.54-cm (1-in.) of firewood. After treatment, all firewood was placed under mesh netting and emerald ash borer were allowed to develop and emerge under natural conditions. No treatments seemed to be successful at eliminating emerald ash borer larvae and perpupae as all treatments (including two nontreated controls) experienced some emerald ash borer emergence. However, the 56 degrees C (132.8 degrees F) treatments did result in considerably less emerald ash borer emergence than the 46 degrees C (114.8 degrees F) treatments. Further investigation is needed to determine whether longer exposure to the higher temperature (56 degrees C) will successfully sanitize emerald ash borer-infested firewood. PMID:20568603

  12. Mineralogy and phase transition of oil sands coke ash

    Energy Technology Data Exchange (ETDEWEB)

    Heemun Jang; Thomas H. Etsell [University of Alberta, Edmonton, AB (Canada). Department of Chemical and Materials Engineering

    2006-08-15

    Coke obtained from Syncrude and Suncor was investigated to characterize the metals and minerals by ashing it at various temperatures. Samples were collected by high temperature ashing at 100{sup o}C intervals from 400 to 1200{sup o}C. Samples were also obtained from low temperature ashing (LTA) which gives little effect on the mineral assemblage compared to HTA samples. X-ray diffraction patterns of Suncor and Syncrude coke ash were analyzed qualitatively and quantitatively to characterize the mineral phases in the sample and their thermal transition behavior. In Suncor ash, kaolinite, illite, gypsum, anhydrite, microcline, anorthite, hematite, sillimanite and quartz were dominant phases in ash from the LTA temperature up to 700{sup o}C, and mullite, cristobalite, hercynite, albite, anorthite, pseudobrookite and other iron-titanium oxides were dominant mineral phases from 700 to 1200{sup o}C. In Syncrude ash, illite, anhydrite, quartz, anorthite, microcline, sillimanite and hematite were dominant up to 700{sup o}C, and hercynite, anorthite, albite, pseudobrookite and other iron-titanium oxides were dominant up to 1200{sup o}C. The higher quantities of Ca, K and Na, and the lower quantities of V, Fe and Ni in Syncrude ash resulted in higher amorphocity and the different mineral phases. 32 refs., 3 figs., 5 tabs.

  13. Washing of granulated solidification fly ash containing radioactive contaminants

    International Nuclear Information System (INIS)

    Incineration fly ash produced from city garbage, water-and-sewage sludge, and wastes generated by radioactive decontamination activities tends to have a high concentration of radioactive materials, and radioactive cesium in fly ash has high solubility in water. In order to advance the safe processing of incineration fly ash, it is necessary to have a technology for reducing the cesium in the fly ash. Washing the fly ash with water is an effective way of reducing the amount of radioactive cesium. Then, this study developed a new method for washing fly ash after granulated solidification. Laboratory tests showed that 70% or more of the radioactive cesium was removed by washing of the granulated solidification fly ash adjusted into 1-9.5 mm diameter particles under the following conditions: flow rate (SV) ≦ 10h-1 and flow volume ≧ 10 times of fly ash volume. Demonstration tests also confirmed the effectiveness of washing and the reduction of the volume of radioactive wastes. (author)

  14. A fly ash and shale fired brick production line

    Institute of Scientific and Technical Information of China (English)

    ZhuYali

    2005-01-01

    The article describes the fly ash and shale fired brick production line with annual output of 1250 million bricks, designed by Xi'an Research and Design Institute of Wall and Roof Material, commissioned by QinDian Building Material Subcompany, and set an example for using fly ash and shale in China.

  15. Soil food web structure after wood ash application

    DEFF Research Database (Denmark)

    Mortensen, L. H.; Qin, J.; Krogh, Paul Henning;

    nutrients from the ecosystem. This can be partly mitigated by applying ash from the combustion back to the system and thus recycle the nutrients. However, besides being rich in inorganic nutrients, ash is also very alkaline and contains heavy metals. The ASHBACK project (www.ashback.dk) is a cooperation...

  16. A study of fly ash-lime granule unfired brick

    Energy Technology Data Exchange (ETDEWEB)

    P. Chindaprasirt; K. Pimraksa [Khon Kaen University (Thailand). Department of Civil Engineering

    2008-02-15

    In this paper, the properties of fly ash-lime granule unfired bricks are studied. Granules were prepared from mixtures of fly ash and lime at fly ash to hydrated lime ratios of 100:0 (Ca/Si = 0.2), 95:5 (Ca/Si = 0.35) and 90:10 (Ca/Si = 0.5). After a period of moist curing, the microstructure and mineralogy of the granules were studied. Microstructure examination reveals that new phases in the form of needle-like particles are formed at the surface of granule. The granules were used to make unfired bricks using hydrothermal treatment at temperature of 130 {+-} 5{sup o}C and pressure of 0.14 MPa. The microstructures, mineralogical compositions, mechanical properties and environmental impact of bricks were determined. The results reveal that the strengths of unfired bricks are dependent on the fineness of fly ash. The strength is higher with an increase in fly ash fineness. The strengths of the fly ash-lime granule unfired brick are excellent at 47.0-62.5 MPa. The high strength is due to the formation of new products consisting mainly of hibschite and Al-substituted 11 {angstrom} tobermorite. The main advantage of utilization of granule is the ability to increase the pozzolanic reaction of fly ash through moisture retained in the granule. In addition, the heavy elements, in particular Cd, Ni, Pb and Zn are efficiently retained in the fly ash-lime granule unfired brick.

  17. Ash handling system of the Elbistan power plant in Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, H.

    1978-12-01

    After giving the main details concerning the brown coal present in the Afsin-Elbistan basin and the ash produced from this coal after it has been burned in the power plant the article discusses the contruction of the conveying plant by means of which the ash is removed.

  18. Fly ash in landfill top covers - a review.

    Science.gov (United States)

    Brännvall, E; Kumpiene, J

    2016-01-01

    Increase of energy recovery from municipal solid waste by incineration results in the increased amounts of incineration residues, such as fly ash, that have to be taken care of. Material properties should define whether fly ash is a waste or a viable resource to be used for various applications. Here, two areas of potential fly ash application are reviewed: the use of fly ash in a landfill top cover either as a liner material or as a soil amendment in vegetation layer. Fly ashes from incineration of three types of fuel are considered: refuse derived fuel (RDF), municipal solid waste incineration (MSWI) and biofuel. Based on the observations, RDF and MSWI fly ash is considered as suitable materials to be used in a landfill top cover liner. Whereas MSWI and biofuel fly ashes based on element availability for plant studies, could be considered suitable for the vegetation layer of the top cover. Responsible application of MSWI ashes is, however, warranted in order to avoid element accumulation in soil and elevation of background values over time. PMID:26701627

  19. Stabilization of Fly Ash Deposits through Selected Cereal Crops

    Directory of Open Access Journals (Sweden)

    Florica Morariu

    2012-10-01

    Full Text Available Fly ash, a waste product from burning coal in power plants, occupies important spaces and is a major harm forenvironment: water, air, soil and associated ecosystems. New deposits do not have available nutrients for plantgrowth. The study presents a process of stimulating growth of oats in deposits of fly ash, which eliminates listed.Phytostabilization of new deposit is fast after fertilization with sewage sludge-based compost in the presence/absence of native or modified volcanic tuff with grain species, Avena sativa L., and variety Lovrin 1. Experimentalstudies have shown the species adaptability to climatic conditions and a growth rate until the maturity correlated withtype of treatment of upper layers of fly ash deposit. Fly ash with sewage sludge compost treatment 50 t/hadetermined the growth with 75% of the amount of grains vs. the amount of grains harvested from untreated fly ash.Fly ash with sewage sludge compost mixed with modified indigenous volcanic tuff 2.5 t/ha treatment determined thegrowth with 80% vs. the amount of grains harvested from untreated fly ash. If oat straw harvested from fertilizedvariant without modified indigenous volcanic tuff increases in weight are 30% and for fertilized variant in thepresence of tuff increases in weight are 39.8% vs. quantities harvested from untreated fly ash.

  20. X-ray microanalysis of volcanic ash

    International Nuclear Information System (INIS)

    The 2010 eruption of Eyjafjallajökull volcano in Iceland demonstrated the disruptive nature of high-level volcanic ash emissions to the world's air traffic. The chemistry of volcanic material is complex and varied. Different eruptions yield both compositional and morphological variation. Equally a single eruption, such as that in Iceland will evolve over time and may potentially produce a range of volcanic products of varying composition and morphology. This variability offers the petrologist the opportunity to derive a tracer to the origins both spatially and temporally of a single particle by means of electron microbeam analysis. EPMA of volcanic ash is now an established technique for this type of analysis as used in tephrachronology. However, airborne paniculate material may, as in the case of Eyjafjallajökull, result in a particle size that is too small and too dispersed for preparation of standard EPMA mounts. Consequently SEM-EDS techniques are preferred for this type of quantitative analysis . Results of quantitative SEM-EDS analysis yield data with a larger precision error than EPMA yet sufficient to source the original eruption. Uncoated samples analyzed using variable pressure SEM yield slightly poorer results at modest pressures.

  1. Mesoporous Silica from Rice Husk Ash

    Directory of Open Access Journals (Sweden)

    S.A. Mandavgane

    2010-12-01

    Full Text Available Mesoporous silica is used as a raw material in several areas: in preparation of catalysts, in inks, as aconcrete hardening accelerator, as a component of detergents and soaps, as a refractory constituent etc.Sodium silicate is produced by reacting rice hull ash (RHA with aqueous NaOH and silica is precipitatedfrom the sodium silicate by acidification. In the present work, conversion of about 90% of silica containedin RHA into sodium silicate was achieved in an open system at temperatures of about 100 °C. The resultsshowed that silica obtained from RHA is mesoporous, has a large surface area and small particle size.Rice Husk is usually mixed with coal and this mixture is used for firing boilers. The RHA therefore, usuallycontains carbon particles. Activated carbon embedded on silica has been prepared using the carbon alreadypresent in RHA. This carbon shows good adsorption capacity. ©2010 BCREC UNDIP. All rights reserved(Received: 25th April 2010, Revised: 17th June 2010, Accepted: 24th June 2010[How to Cite: V.R. Shelke, S.S. Bhagade, S.A. Mandavgane. (2010. Mesoporous Silica from Rice Husk Ash. Bulletin of Chemical Reaction Engineering and Catalysis, 5 (2: 63-67. doi:10.9767/bcrec.5.2.793.63-67

  2. Radioactive wastes dispersed in stabilized ash cements

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, J.B.; Taylor, C.M.V.; Sivils, L.D.; Carey, J.W.

    1997-12-31

    One of the most widely-used methods for the solidification/stabilization of low-level radwaste is by incorporation into Type-I/II ordinary portland cement (OPC). Treating of OPC with supercritical fluid carbon dioxide (SCCO{sub 2}) has been shown to significantly increase the density, while simultaneously decreasing porosity. In addition, the process significantly reduces the hydrogenous content, reducing the likelihood of radiolytic decomposition reactions. This, in turn, permits increased actinide loadings with a concomitant reduction in disposable waste volume. In this article, the authors discuss the combined use of fly-ash-modified OPC and its treatment with SCCO{sub 2} to further enhance immobilization properties. They begin with a brief summary of current cement immobilization technology in order to delineate the areas of concern. Next, supercritical fluids are described, as they relate to these areas of concern. In the subsequent section, they present an outline of results on the application of SCCO{sub 2} to OPC, and its effectiveness in addressing these problem areas. Lastly, in the final section, they proffer their thoughts on why they believe, based on the OPC results, that the incorporation of fly ash into OPC, followed by supercritical fluid treatment, can produce highly efficient wasteforms.

  3. Recovery potential of German sewage sludge ash.

    Science.gov (United States)

    Krüger, Oliver; Adam, Christian

    2015-11-01

    Incineration of sewage sludge is expected to increase in the future due to growing concerns about the direct use of sludge in agriculture. Sewage sludge is the pollutant sink of wastewater treatment and thus loaded with contaminants that might pose environmental hazards. Incineration degrades organic pollutants efficiently, but since the ash is currently mostly disposed of, all valuable component like phosphorus (P) and technologically relevant metals present in the sewage sludge ash (SSA) are removed from the economic cycle entirely. We conducted a complete survey of SSA from German mono-incineration facilities and determined the theoretical recovery potential of 57 elements. German SSA contains up to 19,000 t/a P which equals approximately 13% of phosphorus applied in the German agriculture in form of phosphate rock based mineral fertilizers. Thus, SSA is an important secondary resource of P. However, its P-solubility in ammonium citrate solution, an indicator for the bioavailability, is only about 26%. Treatment of SSA is recommended to enhance P bioavailability and remove heavy metals before it is applied as fertilizer. The recovery potential for technologically relevant metals is generally low, but some of these elements might be recovered efficiently in the course of P recovery exploiting synergies. PMID:25697389

  4. Desaster, destruction, creation: from nothing to ashes

    Directory of Open Access Journals (Sweden)

    Juan Manuel Terenzi

    2016-06-01

    Full Text Available The aim of this article is to briefly discuss about certain notions as nothing, fire, ashes and the creative power that derives from them. To reach this aim, first of all we chose some philosophical concepts extracted from Heidegger's philosophy. Then, we are going to discuss the book De l’esprit: Heidegger et la question from Jacques Derrida, in which he pays attention to the use of the word Geist (mind/spirit. Derrida will investigate the use of this word and its variants in Heidegger’s philosophical work, identifying potential readings that could be hidden, uncovering a huge heideggerian theatrical scenery around this word. The philosopher of deconstruction’s reading makes important contributions and allows the reader new approaches to Heidegger’s philosophy. This two axes will aid our own reading in order to show the relation between those notions: nothing, fire, ashes, related to creative act. In this article other names will also appear, as Heraclitus, Habermas, Wittgenstein and Beckett.

  5. Phosphorus Recovery from Ashes of Sewage Sludge

    Energy Technology Data Exchange (ETDEWEB)

    Cornel, Peter; Schaum, Peter

    2003-07-01

    About 90% of the incoming phosphorus load of waste water is eliminated by waste water treatment and transferred into the sewage sludge. Considerable amounts of sewage sludge can not be used agriculturally but are incinerated. Thus the ash from mono sludge incineration plants contains significant amounts of phosphorus (up to 25% P{sub 2}O{sub 5}) and could be used as raw material in fertilizer industry. The ash is hygienically harmless and free of organic substances. The ratio of phosphorus to heavy metals is basically the same as in the sewage sludge. The first step in separating phosphorus from heavy metals is to dissolve phosphorus by extraction. The most promising way seems to be the release of phosphorus with acids or bases. With 1 m sulphuric acid it is possible to release phosphorus completely. By use of acid most of the heavy metals dissolve, too. With caustic soda as solvent, only 30-40% of the phosphorus can be dissolved but the eluate is almost free of heavy metals. The amount of phosphorus which can be released with caustic soda, depends on the applied precipitant (Al or Fe salts) for phosphorus elimination at the waste water treatment. (author)

  6. Mesoporous Silica from Rice Husk Ash

    Directory of Open Access Journals (Sweden)

    V.R. Shelke

    2011-01-01

    Full Text Available Mesoporous silica is used as a raw material in several areas: in preparation of catalysts, in inks, as a concrete hardening accelerator, as a component of detergents and soaps, as a refractory constituent etc. Sodium silicate is produced by reacting rice hull ash (RHA with aqueous NaOH and silica is precipitated from the sodium silicate by acidification. In the present work, conversion of about 90% of silica contained in RHA into sodium silicate was achieved in an open system at temperatures of about 100 °C. The results showed that silica obtained from RHA is mesoporous, has a large surface area and small particle size. Rice Husk is usually mixed with coal and this mixture is used for firing boilers. The RHA therefore, usually contains carbon particles. Activated carbon embedded on silica has been prepared using the carbon already present in RHA. This carbon shows good adsorption capacity. ©2010 BCREC UNDIP. All rights reserved(Received: 25th April 2010, Revised: 17th June 2010, Accepted: 24th June 2010[How to Cite: V.R. Shelke, S.S. Bhagade, S.A. Mandavgane. (2010. Mesoporous Silica from Rice Husk Ash. Bulletin of Chemical Reaction Engineering and Catalysis, 5 (2: 63-67. doi:10.9767/bcrec.5.2.793.63-67][DOI: http://dx.doi.org/10.9767/bcrec.5.2.793.63-67

  7. Radioactive wastes dispersed in stabilized ash cements

    International Nuclear Information System (INIS)

    One of the most widely-used methods for the solidification/stabilization of low-level radwaste is by incorporation into Type-I/II ordinary portland cement (OPC). Treating of OPC with supercritical fluid carbon dioxide (SCCO2) has been shown to significantly increase the density, while simultaneously decreasing porosity. In addition, the process significantly reduces the hydrogenous content, reducing the likelihood of radiolytic decomposition reactions. This, in turn, permits increased actinide loadings with a concomitant reduction in disposable waste volume. In this article, the authors discuss the combined use of fly-ash-modified OPC and its treatment with SCCO2 to further enhance immobilization properties. They begin with a brief summary of current cement immobilization technology in order to delineate the areas of concern. Next, supercritical fluids are described, as they relate to these areas of concern. In the subsequent section, they present an outline of results on the application of SCCO2 to OPC, and its effectiveness in addressing these problem areas. Lastly, in the final section, they proffer their thoughts on why they believe, based on the OPC results, that the incorporation of fly ash into OPC, followed by supercritical fluid treatment, can produce highly efficient wasteforms

  8. Cadmium in insects after ash fertilization

    Institute of Scientific and Technical Information of China (English)

    Martin Lodenius; Jussi Josefsson; Kari Heli(o)vaara; Esa Tulisalo; Matti Nummelin

    2009-01-01

    Ash fertilization of forests returns nutrients to forest ecosystems and has a positive effect on soil pH.but it also may elevate Cd concentrations of forest biota.Cadmium concentrations of some forest insects(Formica ants.carabids and Coleopteran larvac from decaying wood)were investigated in southern Finland where two plots were fertilized with wood ash,while two other plots represented anfertilized control plots.In ants,mean Cd concentration was 3.6±1.4 mg/kg.with nest workers having significantly higher concen-trations than workers trapped in pitfall traps.Concentrations at fertilized and unfertilized plots were similar.In carabid beetles,the average Cd concentration of Carabus glabratus was 0.44±0.36 mg/kg.with no significant difference between control plots and fertilized plots.In another carabid beetle,Pterostichus niger,mean Cd concentration was higher at fertilized plots compared to control plots.We conclude that the variation of Cd concentra-tions in the insects studied is more efficiently controlled by species-specific differences than fertilization history of the forest floor.

  9. Raman spectroscopy for characterizing and determining the pozzolanic reactivity of fly ashes

    Science.gov (United States)

    Garg, Nishant

    The efficacy and potential of Raman spectroscopy in characterization of a commercial Ordinary Portland Cement (OPC) and three fly ashes (FA's), and their evolving hydration products were studied in this Master's thesis work. While there have been several studies focusing on the application of Raman spectroscopy to synthetic, pure samples, work on commercial cementitious systems is scarce. This work covers this gap by evaluating mixtures containing cements and fly ashes. The study first involved determination followed by establishment of instrumental configuration and testing parameters optimum for studying cementitious materials both in the dry and wet form. It was found that by tweaking several parameters, collection methodologies and analysis techniques, improved, representative and reproducible data could be obtained. Mapping a representative area to determine the spatial distribution and concentration of sulfates and hydroxides on sample surfaces was found to be the most effective way to study these complex and heterogeneous systems. The Raman dry analysis of OPC and three different FA's of varying calcium contents and reactivity was able to identify the major mineralogical phases in these binders and the results were in correlation with the X-ray diffraction data. The observed calcium and sulfate phases and their relative concentration also agreed well with the supplementary compositional data obtained from X-ray fluorescence and Atomic absorption spectrometry. The wet analysis of pastes prepared with 100% OPC and 50%OPC+50%FA(1,2,3) followed the hydration process of the systems for 56 days (0, 0.2, 2, 4, 8, 12, 16, 20, 24, 48, 72 hours, 7, 14, 21, 28, and 56 days). Consistency of trends in the hydration mechanism of such pastes was only obtained when studies were focused on narrow wavenumber ranges: 950--1050 cm-1 for evolution of sulfates and 3600--3700cm-1 for evolution of hydroxides. Gradual disappearance of Gypsum with a parallel formation of Ettringite

  10. Fire severity effects on ash extractable Total Phosphorous

    Science.gov (United States)

    Pereira, Paulo; Úbeda, Xavier; Martin, Deborah

    2010-05-01

    Phosphorous (P) is a crucial element to plant nutrition and limits vegetal production. The amounts of P in soil are lower and great part of this nutrient is absorbed or precipitated. It is well known that fire has important implications on P cycle, that can be lost throughout volatilization, evacuated with the smoke, but also more available to transport after organic matter mineralization imposed by the fire. The release of P depends on ash pH and their chemical and physical characteristics. Fire temperatures impose different severities, according to the specie affected and contact time. Fire severity is often evaluated by ash colour and this is a low-cost and excellent methodology to assess the fire effects on ecosystems. The aim of this work is study the ash properties physical and chemical properties on ash extractable Total Phosphorous (TP), collected in three wildfires, occured in Portugal, (named, (1) Quinta do Conde, (2) Quinta da Areia and (3) Casal do Sapo) composed mainly by Quercus suber and Pinus pinaster trees. The ash colour was assessed using the Munsell color chart. From all three plots we analyzed a total of 102 ash samples and we identified 5 different ash colours, ordered in an increasing order of severity, Very Dark Brown, Black, Dark Grey, Very Dark Grey and Light Grey. In order to observe significant differences between extractable TP and ash colours, we applied an ANOVA One Way test, and considered the differences significant at a p<0.05. The results showed that significant differences in the extractable TP among the different ash colours. Hence, to identify specific differences between each ash colour, we applied a post-hoc Fisher LSD test, significant at a p<0.05. The results obtained showed significant differences between the extractable TP from Very dark Brown and Black ash, produced at lower severities, in relation to Dark Grey, Very Dark Grey and Light Grey ash, generated at higher severities. The means of the first group were higher

  11. Use of coal ash for enhancing biocrust development in stabilizing sand dunes

    Science.gov (United States)

    Zaady, Eli; Katra, Itzhak; Sarig, Shlomo

    2015-04-01

    In dryland environments, biocrusts are considered ecosystem engineers since they play significant roles in ecosystem processes. In the successional pathway of crust communities, the new areas are colonized after disturbance by pioneers such as filamentous cyanobacteria - Microcoleus spp. This stage is followed by colonization of green algae, mosses, and lichens. Aggregation of soil granules is caused by metabolic polysaccharides secreted by cyanobacteria and green algae, gluing the soil particles to form the crust layer. It was suggested that incorporating dust into the biocrusts encourages the growth of cyanobacteria, leading to a strengthening of the biocrusts' cohesion. Moreover, biocrusts cover a larger portion of the surface when the soil contains finer particles, and it was observed that at least 4-5% of clay and silt is required to support a measurable biocrust. While natural and undisturbed sand dunes are generally stabilized by biocrusts in the north-western Negev desert, stabilization of disturbed and movable sand dunes is one of the main problems in this desertified land, as in vast areas in the world. Daily breezes and seasonal wind storms transport sand particles to populated and agricultural areas causing damages to field crops and livelihood. Moving sand dunes consist of relatively coarse grains (250-2000 μm) with a low percent of clay and silt. This phenomenon negatively affects cyanobacterial colonization rate, even in relatively wet desert areas (100-250 mm rainfalls). In order to face the problem it was suggested to enrich the dune surface by using coal fly-ash. The research was conducted in two stages: first, examining the feasibility in Petri-dishes in laboratory conditions and in Experimental Aeolian Greenhouse conditions. The results showed that adding coal fly-ash and biocrust inoculum increased aggregate stability, penetration resistance and shear strength, as opposed to the control-sand plot. Using mobile wind-tunnel simulations, sand

  12. Assessment of high performance concrete containing fly ash and calcium nitrite based corrosion inhibitor as a mean to prevent the corrosion of reinforcing steel

    International Nuclear Information System (INIS)

    This research analyses the effectiveness of the water-to-cement ratio (w/c), fly ash and a calcium nitrite based corrosion inhibitor to prevent the corrosion of reinforcing steel embedded in high performance concrete. The interactive effect between the inhibitor and fly ash was evaluated because the occurrence of a negative effect when both ingredients are added together in a concrete mixture has been reported. All the concrete mixtures studied in this investigation had 8.2% of silica fume. Twenty seven prismatic concrete specimens were fabricated with dimensions of 55 × 230 × 300 mm each containing two steel rods embedded for the purpose of corrosion monitoring. The specimens were exposed to a simulated marine environment with two daily cycles of wetting and drying for one year. To evaluate the deterioration of the specimens corrosion potentials and linear polarization resistance tests were carried out. The results indicate that the use of a low w/c, the addition of fly ash and the addition of the corrosion inhibitor contributed to the reduction of the corrosion of steel in the concrete specimens. The results further suggest that the combination of fly ash and corrosion inhibitor does not promote the deterioration of the concrete matrix

  13. Electrical charging of ash in Icelandic volcanic plumes

    CERN Document Server

    Aplin, Karen L; Nicoll, Keri A

    2014-01-01

    The existence of volcanic lightning and alteration of the atmospheric potential gradient in the vicinity of near-vent volcanic plumes provides strong evidence for the charging of volcanic ash. More subtle electrical effects are also visible in balloon soundings of distal volcanic plumes. Near the vent, some proposed charging mechanisms are fractoemission, triboelectrification, and the so-called "dirty thunderstorm" mechanism, which is where ash and convective clouds interact electrically to enhance charging. Distant from the vent, a self-charging mechanism, probably triboelectrification, has been suggested to explain the sustained low levels of charge observed on a distal plume. Recent research by Houghton et al. (2013) linked the self-charging of volcanic ash to the properties of the particle size distribution, observing that a highly polydisperse ash distribution would charge more effectively than a monodisperse one. Natural radioactivity in some volcanic ash could also contribute to self-charging of volcan...

  14. Use of Recycled Aggregate and Fly Ash in Concrete Pavement

    Directory of Open Access Journals (Sweden)

    Myle N. James

    2011-01-01

    Full Text Available Problem statement: Recycled materials aggregate from the demolished concrete structures and fly ash from burning coal shows the possible application as structural and non structural components in concrete structures. This research aims to evaluate the feasibility of using concrete containing recycled concrete aggregate and fly ash in concrete pavement. Approach: Two water cement ratio (0.45 and 0.55 the compressive strength, modulus of electricity and flexural strength for concrete with recycled aggregate and fly ash with 0, 25% replacing cement in mass were considered. Results: The material properties of recycled aggregate concrete with fly ash indicate comparable results with that of concrete with natural aggregate and without fly ash. Conclusion/Recommendations: The recycled materials could be used in concrete pavement and it will promote the sustainability of concrete.

  15. Synthesis and characterization of fly ash-zinc oxide nanocomposite

    Directory of Open Access Journals (Sweden)

    Kunal Yeole

    2014-04-01

    Full Text Available Fly ash, generated in thermal power plants, is recognized as an environmental pollutant. Thus, measures are required to be undertaken to dispose it in an environmentally friendly method. In this paper an attempt is made to coat zinc oxide nano-particles on the surface of fly ash by a simple and environmentally friendly facile chemical method, at room temperature. Zinc oxide may serve as effective corrosion inhibitor by providing sacrificial protection. Concentration of fly ash was varied as 5, 10 and 15 (w/w % of zinc oxide. It was found that crystallinity increased, whereas particle size, specific gravity and oil absorption value decreased with increased concentration of fly ash in zinc oxide, which is attributed to the uniform distribution of zinc oxide on the surface of fly ash. These nanocomposites can potentially be used in commercial applications as additive for anticorrosion coatings.

  16. Leaching Behavior of Fly Ashes from Power Plants

    Institute of Scientific and Technical Information of China (English)

    LIU Guijian; GAO Lianfen; ZHENG Liugen; ZHANG Haoyuan; PENG Zicheng

    2004-01-01

    The Yanzhou mine district, located in southwestern Shandong Province, is about 1300 km2 with more than 8×109 tons of proved coal reserves and there are 10 big power plants in this area. A large amount of coal ashes, which are regarded as waste materials, have been stockpiled in the area and have influenced the environment of the mine district. In this paper, analysis of fly ash samples from three power plants is carried out, the enrichment and concentration of trace elements, Pb, Zn, Cu and As, in coal ashes are analyzed, and petrological and mineralogical characteristics and chemical compositions of coal ashes are studied. The aim of this work is to provide basic scientific data for utilization of ashes and reduction of environmental pollutions.

  17. Optical properties of fly ash. Volume 1, Final report

    Energy Technology Data Exchange (ETDEWEB)

    Self, S.A.

    1994-12-01

    Research performed under this contract was divided into four tasks under the following headings: Task 1, Characterization of fly ash; Task 2, Measurements of the optical constants of slags; Task 3, Calculations of the radiant properties of fly ash dispersions; and Task 4, Measurements of the radiant properties of fly ash dispersions. Tasks 1 and 4 constituted the Ph.D. research topic of Sarbajit Ghosal, while Tasks 2 and 3 constituted the Ph.D. research topic of Jon Ebert. Together their doctoral dissertations give a complete account of the work performed. This final report, issued in two volumes consists of an executive summary of the whole program followed by the dissertation of Ghosal. Volume 1 contains the dissertation of Ghosal which covers the characterization of fly ash and the measurements of the radiant properties of fly ash dispersions. A list of publications and conference presentations resulting from the work is also included.

  18. Leaching of nutrient salts from fly ash from biomass combustion

    DEFF Research Database (Denmark)

    Thomsen, Kaj; Vu, Duc Thuong; Stenby, Mette;

    2005-01-01

    Methods to selectively leach nutrient salts from fly ash, while leaving cadmium un-dissolved were studied. Temperature, pH, water to fly ash ratio are all expected to influence the kinetics and the equilibrium boundaries for this process. Three different leaching methods were investigated. The...... moving bed process with agitation/centrifugation. It was found that a satisfactory leaching of the nutrient salts could be achieved with the third method using only two or three stages, depending on the water to fly ash ratio. It is an advantage to perform the process at temperatures above 50°C as the...... first method was a counter current moving bed process in four stages. The ash was kept in filter bags and leached with water that was introduced into the bags at 40-50°C. In the second method, fly ash and water was brought into contact in a partially fluidized bed. The third method was a counter current...

  19. Dioxin contents in fly ashes of MSW incineration in Taiwan.

    Science.gov (United States)

    Chang, M B; Chung, Y T

    1998-04-01

    Fly ashes from three municipal solid waste (MSW) incinerators in Taiwan were collected and segregated into different fractions for determining the physical and chemical properties and dioxin contents. Analysis of ashes with each fraction indicated that fine particles had higher dioxin contents than large particles. Dioxin homologue components of ashes generated from large-scale mass burn MSW incinerator were less toxic than that from small-scale batch incinerators, and contained less non-2,3,7,8 PCDD/Fs. Correlation analysis did not reveal a consistent trend between dioxins content and ashes' physical properties, while strong positive correlation was found between dioxins content and chloride content. Positive correlation between dioxin content and heavy metals content such as copper and zinc in the fly ash was also established. PMID:9532726

  20. Synthesis and characterization of zeolites prepared from industrial fly ash

    OpenAIRE

    Franus, Wojciech; Wdowin, Magdalena; Franus, Małgorzata

    2014-01-01

    In this paper, we present the possibility of using fly ash to produce synthetic zeolites. The synthesis class F fly ash from the Stalowa Wola SA heat and power plant was subjected to 24 h hydrothermal reaction with sodium hydroxide. Depending on the reaction conditions, three types of synthetic zeolites were formed: Na-X (20 g fly ash, 0.5 dm3 of 3 mol · dm−3 NaOH, 75 °C), Na-P1 (20 g fly ash, 0.5 dm3 of 3 mol · dm−3 NaOH, 95 °C), and sodalite (20 g fly ash, 0.8 dm3 of 5 mol · dm−3 NaOH + 0.4...