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Sample records for bottom ash forming

  1. Hydrothermal treatment of MSWI bottom ash forming acid-resistant material

    International Nuclear Information System (INIS)

    To recycle municipal solid waste incinerator (MSWI) bottom ash, synthesis of hydrothermal minerals from bottom ash was performed to stabilize heavy metals. MSWI bottom ash was mixed with SiO2, Al(OH)3, and Mg(OH)2 so its chemical composition was similar to that of hydrothermal clay minerals. These solid specimens were mixed with water at a liquid/solid ratio of 5. The reaction temperature was 200 deg. C, and reactions were performed for 24-240 h. Generation of kaolinite/smectite mixed-layer clay mineral was found in the samples after the reaction of the mixture of bottom ash, SiO2, and Mg(OH)2. Calcium silicate hydrate minerals such as tobermorite and xonotlite were also generated. X-ray powder diffraction suggested the presence of amorphous materials. Leaching tests at various pHs revealed that the concentration of heavy metals in the leachates from MSWI bottom ash hydrothermally treated with SiO2 and Mg(OH)2 was lower than that in leachates from non-treated bottom ash, especially under acid conditions. Hydrothermal treatment with modification of chemical composition may have potential for the recycling of MSWI bottom ash

  2. 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.

  3. 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),

  4. Formation of Humic Substances in Weathered MSWI Bottom Ash

    Directory of Open Access Journals (Sweden)

    Haixia Zhang

    2013-01-01

    Full Text Available The study aimed at evaluating the humic substances (HSs content from municipal solid waste incinerator (MSWI bottom ash and its variation with time and the effect of temperature on HSs formation. The process suggested by IHSS was applied to extract HSs from two different bottom ash samples, and the extracted efficiency with NaOH and Na4P2O7 was compared. MSWI bottom ash samples were incubated at 37∘C and 50∘C for 1 year. HSs and nonhumic substances were extracted from the bottom ash sample with different incubated period by 0.1 M NaOH/Na4P2O7. Results show that the rate of humic acid formation increased originally with incubation time, reached a maximum at 12th week under 37∘C and at 18th week under 50∘C, and then decreased with time. More humic acid in MSWI bottom ash was formed under 50∘C incubated condition compared with that incubated under 37∘C. Also, the elemental compositions of HSs extracted from bottom ash are reported.

  5. 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...

  6. Characterization of Inorganic Elements in Woody Biomass Bottom Ash from a Fixed-bed Combustion System, a Downdraft Gasifier and a Wood Pellet Burner by Fractionation

    OpenAIRE

    Adrian K. James; Steve S. Helle; Thring, Ronald W.; Gurkaran S. Sarohia; P. Michael Rutherford

    2014-01-01

    The direct combustion of biomass residues produces large quantities of bottom ash. Environmental sustainable management requires that ash recycling should be carried out whenever possible. Suitable applications of bottom ash are based predominantly on its chemical properties. The presence of major ash forming and trace elements along with other intrinsic properties unique to bottom ash, suggest its potential as a soil additive. But, ash quality must be of a high standard to prevent environmen...

  7. 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.

  8. Pretreatment and utilization of waste incineration bottom ashes

    DEFF Research Database (Denmark)

    Astrup, Thomas

    2007-01-01

    Within recent years, researchers and authorities have had increasing focus on leaching properties from waste incineration bottom ashes. Researchers have investigated processes such as those related to carbonation, weathering, metal complexation, and leaching control. Most of these investigations...

  9. Understanding the chemical and mineralogical properties of the inorganic portion of MSWI bottom ash.

    Science.gov (United States)

    Bayuseno, A P; Schmahl, W W

    2010-01-01

    This paper investigates the changes of mineralogical composition of bottom ash in the environment. The chemical and mineralogical bulk composition was determined by X-ray fluorescence (XRF) and X-ray powder diffraction (XRPD) Rietveld method. Single bottom ash particles were investigated by optical microscopy, scanning electron microscopy with quantitative energy-dispersive X-ray microanalysis (SEM/EDX) and electron probe micro analysis (EPMA). SEM/EDX and EPMA are valuable complement to bulk analysis and provide means for rapid and sensitive multi-elemental analysis of ash particles. The fresh bottom ash consists of amorphous (>30 wt.%) and major crystalline phases (>1 wt.%) such as silicates, oxides and carbonates. The mineral assemblage of the fresh bottom ash is clearly unstable and an aging process occurs by reaction towards an equilibrium mineral phase composition in the environmental conditions. The significant decrease of anhydrite and amorphous contents was observed in the aged bottom ash, leading to the formation of ettringite, hydrocalumite and rosenhahnite under atmospheric conditions. In the water-treated sample, the calcite contents increased significantly, but ettringite was altered by the dissolution and precipitation processes in part, to produce gypsum, while the remaining part reacted with chloride to form hydrocalumite. Gypsum and other Ca based minerals may take up substantial amounts of heavy metals and subsequently control leaching behaviour of bottom ash. PMID:20381330

  10. Treated bottom ash medium and method of arsenic removal from drinking water

    Science.gov (United States)

    Gadgil, Ashok

    2009-06-09

    A method for low-cost arsenic removal from drinking water using chemically prepared bottom ash pre-treated with ferrous sulfate and then sodium hydroxide. Deposits on the surface of particles of bottom ash form of activated iron adsorbent with a high affinity for arsenic. In laboratory tests, a miniscule 5 grams of pre-treated bottom ash was sufficient to remove the arsenic from 2 liters of 2400 ppb (parts per billion) arsenic-laden water to a level below 50 ppb (the present United States Environmental Protection Agency limit). By increasing the amount of pre-treated bottom ash, even lower levels of post-treatment arsenic are expected. It is further expected that this invention supplies a very low-cost solution to arsenic poisoning for large population segments.

  11. 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.

  12. Synthesis and characterization of geopolymer from bottom ash and rice husk ash

    Science.gov (United States)

    Anggarini, Ufafa; Sukmana, Ndaru C.

    2016-02-01

    All Geopolymer (GP) has been synthesized from bottom ash and rice husk ash. This research aims to determine the effect of Si/Al ratio on geopolymer synthesis. Geopolymer was synthesized with various Si/Al ratio of 2, 3 and 4. The characterization result using XRD and SEM indicated that by using a different ratio of Si/A, it will produce geopolymer with varied structure and morphology. Diffractogram result shows that polymerization has been done for all samples (GP2, GP3, Gp4) with the presence of hump peak at 2θ = 27-35°. In GP4, no peak at 2θ = 18° indicating sodalite phase forming. Besides that, the morphology of geopolymer with a varied ratio of Si/Al shows that higher ratio will produce geopolymer with higher particle size. The highest compressive strength of geopolymer was obtained at a ratio of Si/Al = 4, with a maximum load of 12866 kgf.

  13. Utilization of Meat and Bone Meal Bottom Ash in Ceramics

    Directory of Open Access Journals (Sweden)

    Virginija VALANČIENĖ

    2011-03-01

    Full Text Available During utilization of animal waste meat and bone meal (MBM is received, realization and use of which has been stopped due to risk for the transmission of the bovine spongiform encephalopathy infection. The MBM must be safely stored or treated. Most often meat and bone meal undergoes thermal treatment. During combustion large quantities of residues (ashes are received, the recycled use of which has been given a lot of attention lately. In this work it was investigated the impact of the additive of the bottom ash (BA formed during combustion of the MBM on the properties of forming mass and ceramic body of hydromica clay, and also it was evaluated a possibility to use the MBM BA in manufacturing of building ceramics. After replacing the sand in porous ceramics by this additive the plasticity of the forming mass, drying and firing shrinkage as well as density of ceramic body changed insignificantly whereas the compressive strength increased by 8 % - 22 %. So the MBM BA can be utilized in production of porous ceramics.http://dx.doi.org/10.5755/j01.ms.17.1.256

  14. An efficient and not polluting bottom ash extraction system

    International Nuclear Information System (INIS)

    This paper reports that boiler waste water effluent must meet more and more tighter requirements to comply with environmental regulations; sluice water resulting from bottom ash handling is one of the main problems in this context, and many utilities are under effort to maximize the reuse of the sluice water, and, if possible, to meet the aim of zero water discharge from bottom ash handling system. At the same time ash reuse efforts gain strength in order to minimize waste production. One solution to these problems can be found in an innovative Bottom Ash Extraction System (MAC System), marked by the peculiarity to be a continuous dry ash removal; the system has been developed in the last four years by MAGALDI INDUSTRIE SRL in collaboration with ANSALDO Ricerche, the R and D department of ANSALDO, the main Italian Boiler Manufacturer, and is now installed in six ENEL Boilers. The elimination of the water as separation element between the bottom part of the furnace and the outside atmosphere gives advantages mainly from the environmental view point, but a certain improvement in the boiler efficiency has also been demonstrated by the application of the system

  15. Flowable Backfill Materials from Bottom Ash for Underground Pipeline

    Directory of Open Access Journals (Sweden)

    Kyung-Joong Lee

    2014-04-01

    Full Text Available The purpose of this study was to investigate the relationship between strength and strain in manufacturing controlled low strength materials to recycle incineration bottom ash. Laboratory tests for controlled low strength materials with bottom ash and recycled in-situ soil have been carried out. The optimum mixing ratios were 25%–45% of in-situ soil, 30% of bottom ash, 10%–20% of fly ash, 0%–3% of crumb rubber, 3% of cement, and 22% of water. Each mixture satisfied the standard specifications: a minimum 20 cm of flowability and 127 kPa of unconfined compressive strength. The average secant modulus (E50 was (0.07–0.08 qu. The ranges of the internal friction angle and cohesion for mixtures were 36.5°–46.6° and 49.1–180 kPa, respectively. The pH of all of the mixtures was over 12, which is strongly alkaline. Small-scale chamber tests for controlled low strength materials with bottom ash and recycled in-situ soil have been carried out. Vertical deflection of 0.88–2.41 mm and horizontal deflection of 0.83–3.72 mm were measured during backfilling. The vertical and horizontal deflections of controlled low strength materials were smaller than that of sand backfill.

  16. 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

  17. Mineralogical characterization of municipal solid waste incineration bottom ash with an emphasis on heavy metal-bearing phases

    International Nuclear Information System (INIS)

    Municipal solid waste incineration (MSWI) bottom ash contains a considerable amount of heavy metals. The occurrence and uneven distribution of these heavy metals in bottom ash can increase the complexity of such residues in terms of long-term behavior upon landfilling or recycling. Bottom ashes sampled from three stoker-type incinerators in Japan were analyzed in this paper. This study presents detailed information on the mineralogical characterization of bottom ash constituents and the weathering behavior of these constituents by means of optical microscopy and scanning electron microscopy. It was revealed that bottom ash mainly consists of assorted silicate-based glass phases (48-54 wt% of ash) and mineral phases including melilites, pseudowollastonite, spinels, and metallic inclusions (Fe-P, Fe-S, Fe-Cu, Cu-Sn, Cu-Zn, Cu-S, and Cu-Pb dominated phases), as melt products formed during the incineration process. The compounds embedded in the glass matrix, e.g. spinels and metallic inclusions, played the most important role in concentration of heavy metals (Pb, Zn, Cu, Cr, Mn, Ni, etc.). Other phases such as refractory minerals and ceramics, frequently found in ash, were of less significance in terms of their influence on the involvement of heavy metals. Analysis of lab-scale artificially weathered and 10-year landfilled bottom ash samples revealed that secondary mineralization/alteration of the bottom ash constituents principally carbonation and glass evolution substantially decreased the potential risk of the heavy metals to the surrounding environment.

  18. The Use of Coal Bottom Ash In Hot Mix Asphalt

    Directory of Open Access Journals (Sweden)

    Charles Begyina Kodjo Nketsiah

    2015-05-01

    Full Text Available Bottom ash is a waste material from coal burnt to generate electric power. It is incombustible and non-biodegradable; hence, the best way to dispose it is by recycling rather than incineration and land filling. Past research on bottom ash in road building have focused mainly on embankment filling, sub-base and base courses; except boiler slag which has received much attention in Hot Mix Asphalt (HMA. Bottom ash from Tanjung Bin Power Station was thus investigated through laboratory testing to justify its use in HMA construction in Malaysia. This Paper analysed the data with regards to performance in HMA. In the Marshall Mix design, the material largely satisfied the Stability, Flow and Stiffness requirements which were comparable to that of conventional aggregates, although void contents were a bit higher. When blended with granite, all the parameters were met. Contrary to past suggestions that bottom ash in HMA consumes more bitumen, the 6.4% (51.20g Optimum Bitumen Content (OBC achieved in this study does not necessarily translate into high consumption, compared to OBC of 5.3% (59.63g in the case of granite. The HMA also proved to be highly resistant to moisture-induced damage and satisfied the minimum JKR specification for Static Uniaxial Load Strain.

  19. MSWI Bottom Ash Characterization and Resource Recovery Potential Assessment.

    Czech Academy of Sciences Publication Activity Database

    Šyc, Michal; Kameníková, Petra; Krausová, Aneta; Zach, Boleslav; Pohořelý, Michael; Svoboda, Karel; Punčochář, Miroslav

    2015-01-01

    Roč. 2, č. 36 (2015), s. 79-84. ISSN 1640-4902 R&D Projects: GA TA ČR TE02000236 Institutional support: RVO:67985858 Keywords : MSWI * bottom ash * metal recovery Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  20. Recovery Potential of Bottom Ash from Municipal Solid Waste Incineration

    Czech Academy of Sciences Publication Activity Database

    Kameníková, Petra; Šyc, Michal; Krausová, A.; Pohořelý, Michael; Zach, Boleslav; Svoboda, Karel; Punčochář, Miroslav

    Prague: Czech Technical University, 2015, s. 1-6. ISBN N. [International Conference for Young Researchers and PhD Students /9./. Monínec (CZ), 04.05.2015-06.05.2014] R&D Projects: GA TA ČR TE02000236 Institutional support: RVO:67985858 Keywords : MSWI * bottom ash * material recovery Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  1. 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)

  2. Speciation of Chromium in Bottom Ash Obtained by the Incineration of the Leather Waste Shavings

    Directory of Open Access Journals (Sweden)

    k. louhab

    2006-01-01

    Full Text Available The evolution of bottom ash morphology and chromium metals behavior during incineration of a leather waste shavings at different incineration temperature have been studied. The Cr, Ca, Mg, Cl rates in bottom ashes, flay ashes and emitted gases in different incineration temperature of the tannery wastes are also determined. The morphology of the bottom ashes obtained by incineration at different temperature from the leather waste shavings was examined by MEB. The result show that the temperature and the length of incineration influence on the structure of the bottom ash and on the chromium in the bottom ash.

  3. 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.

  4. Electrostatic separation of municipal solid waste incineration bottom ash

    OpenAIRE

    Pasanen, Elina

    2014-01-01

    The recovery of copper and precious metals from fine (0-2 mm) non-ferrous fraction of municipal solid waste incineration (MSWI) bottom ash with a two-roll corona electrostatic separator was investigated. Corona electrostatic separator is typically used for separation of fine granular mixture with large differences in electrical conductivities of particles, f.e. mixture of plastic and metal. However, in this work the main objective was to find out if the selectivity of the corona electrostatic...

  5. Kinetic analysis of crystal violet adsorption on to bottom ash

    OpenAIRE

    NIDHEESH, Puthiya Veetil; Gandhimathi, Rajan

    2012-01-01

    The adsorption behavior of crystal violet (CV) from aqueous solution onto bottom ash was investigated under various experimental conditions. The parameters studied included contact time, initial CV concentration, particle size, and ionic strength. The kinetic experimental data were analyzed by different models. The experimental adsorption data showed good correlation with the kinetic models and suggested a multimechanism sorption process. The adsorption mechanisms follow pseudo-sec...

  6. The impact of thermal treatment and cooling methods on municipal solid waste incineration bottom ash with an emphasis on Cl.

    Science.gov (United States)

    Yang, Shuo; Saffarzadeh, Amirhomayoun; Shimaoka, Takayuki; Kawano, Takashi; Kakuta, Yoshitada

    2016-10-01

    Municipal solid waste incineration (MSWI) bottom-ash products possess qualifications to be utilized in cement production. However, the instant use of bottom ash is inhibited by a number of factors, among which the chlorine (Cl) content is always strictly restricted. In this paper, the unquenched MSWI bottom ash was used as the experimental substance, and the influences of thermal treatment and cooling methods on the content and existence of Cl in the ash residues were investigated. The characterization of the MSWI bottom-ash samples examined by utilizing X-ray diffraction, optical microscopy, scanning electron microscopy/energy dispersive X-ray spectroscopy. The experimental results show that as a function of thermal treatment, the reduction rate of Cl is slight below 15.0%, which is relatively low compared with water washing process. Different cooling methods had impacts on the existing forms of Cl. It was understood that most of Cl existed in the glass phase if the bottom ash was air cooled. Contrarily in case of water-quenched bottom ash, Cl could also be accumulated in the newly-formed quench products as chloride salts or hydrate substances such as Friedel's salt. PMID:26895375

  7. To fractionate municipal solid waste incineration bottom ash: Key for utilisation?

    Science.gov (United States)

    Sormunen, Laura Annika; Rantsi, Riina

    2015-11-01

    For the past decade, the Finnish waste sector has increasingly moved from the landfilling of municipal solid waste towards waste incineration. New challenges are faced with the growing amounts of municipal solid waste incineration bottom ash, which are mainly landfilled at the moment. Since this is not a sustainable or a profitable solution, finding different utilisation applications for the municipal solid waste incineration bottom ash is crucial. This study reports a comprehensive analysis of bottom ash properties from one waste incineration plant in Finland, which was first treated with a Dutch bottom ash recovery technique called advanced dry recovery. This novel process separates non-ferrous and ferrous metals from bottom ash, generating mineral fractions of different grain sizes (0-2 mm, 2-5 mm, 5-12 mm and 12-50 mm). The main aim of the study was to assess, whether the advanced bottom ash treatment technique, producing mineral fractions of different grain sizes and therefore properties, facilitates the utilisation of municipal solid waste incineration bottom ash in Finland. The results were encouraging; the bottom ash mineral fractions have favourable behaviour against the frost action, which is especially useful in the Finnish conditions. In addition, the leaching of most hazardous substances did not restrict the utilisation of bottom ash, especially for the larger fractions (>5 mm). Overall, this study has shown that the advanced bottom ash recovering technique can be one solution to increase the utilisation of bottom ash and furthermore decrease its landfilling in Finland. PMID:26330401

  8. Properties of ceramics prepared using dry discharged waste to energy bottom ash dust.

    Science.gov (United States)

    Bourtsalas, Athanasios; Vandeperre, Luc; Grimes, Sue; Themelis, Nicolas; Koralewska, Ralf; Cheeseman, Chris

    2015-09-01

    The fine dust of incinerator bottom ash generated from dry discharge systems can be transformed into an inert material suitable for the production of hard, dense ceramics. Processing involves the addition of glass, ball milling and calcining to remove volatile components from the incinerator bottom ash. This transforms the major crystalline phases present in fine incinerator bottom ash dust from quartz (SiO(2)), calcite (CaCO(3)), gehlenite (Ca(2)Al(2)SiO(7)) and hematite (Fe(2)O(3)), to the pyroxene group minerals diopside (CaMgSi(2)O(6)), clinoenstatite (MgSi(2)O(6)), wollastonite (CaSiO(3)) together with some albite (NaAlSi(3)O(8)) and andradite (Ca(3)Fe(2)Si(3)O(12)). Processed powders show minimal leaching and can be pressed and sintered to form dense (>2.5 g cm(-3)), hard ceramics that exhibit low firing shrinkage (zero water absorption. The research demonstrates the potential to beneficially up-cycle the fine incinerator bottom ash dust from dry discharge technology into a raw material suitable for the production of ceramic tiles that have potential for use in a range of industrial applications. PMID:26060195

  9. Foamed bitumen stabilization of MSWI bottom ash; Skumbitumenstabilisering av bottenaska fraan avfallsfoerbraenning

    Energy Technology Data Exchange (ETDEWEB)

    Bendz, David [Swedish Geotechnical Inst., Linkoeping (Sweden); Jacobsson, Torbjoern [Swedish National Road and Transport Research Inst., Linkoeping (Sweden); Svensson, Mikael; Flyhammar, Peter [Lund Inst. of Technology (Sweden). Dept. of Water Resources Engineering

    2006-04-15

    Mn and Cu, but also Zn, Co, Cd and Hg. In contrary, the results from the monolithic leaching test show a lower leaching of Mn and Cu as the content of bitumen gets higher. The results from the monolithic leaching test are regarded to be more relevant for a field scenario. The pH-static test showed a lower buffering capacity and less leaching of most pH-dependent elements at extreme pH-values for bottom ash treated with foamed bitumen. The results show a positive effect for Sb and Se over the whole pH-interval, which indicate that the leaching is governed by the available surface. A geotechnical investigation was conducted on cylindrical samples of bottom ash stabilized with foamed bitumen, bitumen emulsion and cement (in total 6 mixtures). The bitumen-stabilized samples show a high porosity 26-30 vol%, and low bulk density. The mixture with 4.5% foamed bitumen show the highest stiffness module and the highest stability: 2800 Mpa and stability: 27 KN. Here, the mixture fulfills the requirements set by the Swedish road administration: >2000 MPa and >7kN, resp. The bulk density of cement stabilized bottom ash is 1,80-1,85 kg/dm{sup 3}. The cement stabilized bottom ash fulfills the requirement with respect to pressure strength. Since the smallest particles are covered preferentially with bitumen the treated bottom ash is probably less likely to form dust, which is favorable from health risk perspective.

  10. Adsorption of Crystal Violet Dye from Aqueous Solution onto Zeolites from Coal Fly and Bottom Ashes

    OpenAIRE

    Tharcila Colachite Rodrigues Bertolini; Juliana C. Izidoro; Carina P. Magdalena; Denise A. Fungaro

    2013-01-01

    The adsorption of the cationic dye Crystal Violet (CV) over zeolites from coal fly ash (ZFA) and bottom ash (ZBA) was evaluated. The coal fly ash (CFA) and the coal bottom ash (CBA) used in the synthesis of the zeolites by alkaline hydrothermal treatment were collected in Jorge Lacerda coal-fired power plant located at Capivari de Baixo County, in Santa Catarina State, Brazil. The zeolitic materials were characterized predominantly as hydroxy-sodalite and X. The dye adsorption equilibrium was...

  11. 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

  12. Modeling the formation of the quench product in municipal solid waste incineration (MSWI) bottom ash.

    Science.gov (United States)

    Inkaew, Kanawut; Saffarzadeh, Amirhomayoun; Shimaoka, Takayuki

    2016-06-01

    This study investigated changes in bottom ash morphology and mineralogy under lab-scale quenching conditions. The main purpose was to clarify the mechanisms behind the formation of the quench product/layer around bottom ash particles. In the experiments, the unquenched bottom ashes were heated to 300°C for 1h, and were quenched by warm water (65°C) with different simulated conditions. After having filtered and dried, the ashes were analyzed by a combination of methodologies namely, particle size distribution analysis, intact particle and thin-section observation, X-ray diffractometry, and scanning electron microscope with energy dispersive X-ray spectroscopy. The results indicated that after quenching, the morphology and mineralogy of the bottom ash changed significantly. The freshly quenched bottom ash was dominated by a quench product that was characterized by amorphous and microcrystalline calcium-silicate-hydrate (CSH) phases. This product also enclosed tiny minerals, glasses, ceramics, metals, and organic materials. The dominant mineral phases produced by quenching process and detected by XRD were calcite, Friedel's salt, hydrocalumite and portlandite. The formation of quench product was controlled by the fine fraction of the bottom ash (particle size <0.425mm). From the observations, a conceptual model of the ash-water reactions and formation of the quench product in the bottom ash was proposed. PMID:27079853

  13. Contribution of natural organic matter to copper leaching from municipal solid waste incinerator bottom ash

    NARCIS (Netherlands)

    Zomeren, van A.; Comans, R.N.J.

    2004-01-01

    The leaching of heavy metals, such as copper, from municipal solid waste incinerator (MSWI) bottom ash is a concern in many countries and may inhibit the beneficial reuse of this secondary material. The enhanced leaching of copper from three MSWI bottom ash samples by dissolved organic carbon (DOC)

  14. Adsorption of organic pollutants from coking and papermaking wastewaters by bottom ash

    Energy Technology Data Exchange (ETDEWEB)

    Sun Weiling [Department of Environmental Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871 (China)], E-mail: sunweiling@iee.pku.edu.cn; Qu Yanzhi; Yu Qing; Ni Jinren [Department of Environmental Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871 (China)

    2008-06-15

    Bottom ash, a power plant waste, was used to remove the organic pollutants in coking wastewater and papermaking wastewater. Particular attention was paid on the effect of bottom ash particle size and dosage on the removal of chemical oxygen demand (COD). UV-vis spectra, fluorescence excitation-emission matrix (FEEM) spectra, Fourier transform infrared (FTIR) spectra, and scanning electron microscopic (SEM) photographs were investigated to characterize the wastewaters and bottom ash. The results show that the COD removal efficiencies increase with decreasing particle sizes of bottom ash, and the COD removal efficiency for coking wastewater is much higher than that for papermaking wastewater due to its high percentage of particle organic carbon (POC). Different trends of COD removal efficiency with bottom ash dosage are also observed for coking and papermaking wastewaters because of their various POC concentrations. Significant variations are observed in the FEEM spectra of wastewaters after treatment by bottom ash. New excitation-emission peaks are found in FEEM spectra, and the fluorescence intensities of the peaks decrease. A new transmittance band in the region of 1400-1420 cm{sup -1} is observed in FTIR spectra of bottom ash after adsorption. The SEM photographs reveal that the surface of bottom ash particles varies evidently after adsorption.

  15. Adsorption of organic pollutants from coking and papermaking wastewaters by bottom ash

    International Nuclear Information System (INIS)

    Bottom ash, a power plant waste, was used to remove the organic pollutants in coking wastewater and papermaking wastewater. Particular attention was paid on the effect of bottom ash particle size and dosage on the removal of chemical oxygen demand (COD). UV-vis spectra, fluorescence excitation-emission matrix (FEEM) spectra, Fourier transform infrared (FTIR) spectra, and scanning electron microscopic (SEM) photographs were investigated to characterize the wastewaters and bottom ash. The results show that the COD removal efficiencies increase with decreasing particle sizes of bottom ash, and the COD removal efficiency for coking wastewater is much higher than that for papermaking wastewater due to its high percentage of particle organic carbon (POC). Different trends of COD removal efficiency with bottom ash dosage are also observed for coking and papermaking wastewaters because of their various POC concentrations. Significant variations are observed in the FEEM spectra of wastewaters after treatment by bottom ash. New excitation-emission peaks are found in FEEM spectra, and the fluorescence intensities of the peaks decrease. A new transmittance band in the region of 1400-1420 cm-1 is observed in FTIR spectra of bottom ash after adsorption. The SEM photographs reveal that the surface of bottom ash particles varies evidently after adsorption

  16. High temperature co-treatment of bottom ash and stabilized fly ashes from waste incineration

    DEFF Research Database (Denmark)

    Sørensen, Mette Abildgaard; Mogensen, E.P.B.; Lundtorp, Kasper;

    2001-01-01

    Bottom ashes from two Danish municipal solid waste incineration plants were heated at 900 degreesC with iron oxide stabilized air pollution control residues at actual mass flow ratios (9:1), simulating a treating method for the residues. The two residues were cotreated, producing one combined...... stream that may be utilized as a secondary road construction material. Scanning electron microscope analysis and grain size distribution analysis indicated that sintering of the particles did not occur. Batch leaching tests at liquid/solid 10 I/kg at a range of pH-values (6-10) quantified with respect to...

  17. Comparison of various bioassays for dioxins measurements in fuel gas, fly ash and bottom ash

    Energy Technology Data Exchange (ETDEWEB)

    Ota, S.; Kin-ichi, S. [Ministry of the Environment, Tokyo (Japan); Masatoshi, M.; Shin-ichi, S. [National Institute for Environmental Studies, Tsukuba (Japan)

    2004-09-15

    In Japan, the control standards for dioxins (PCDDs, PCDFs and Co-PCBs) in the emission gas, fly and bottom ashes from waste incinerators have been defined in the Law Concerning Special Measures against Dioxins (Dioxins Law). Based on the Dioxins law, an installation personnel of waste incinerators of specified facilities shall measure dioxins in the emission gas and fly and bottom ashes more than once every year followed by reporting the results to their prefectural governor. The present regulating procedure has been set to use high-resolution gas chromatography/ high-resolution mass spectrometry (HRGC/HRMS, hereafter GC/MS) systems to determine dioxin-concentrations. However, the GC/MS measurements are often money- and timeconsuming, since they need complicated steps for sample preparation, expensive equipments and highly skilled technicians. Therefore, it is of high priority to develop rapid and economical alternative methods to measure dioxins. Recently, various assays using biological reactions have drawn a high degree of attention as a candidate for alternative measurement methods of dioxins. During the past decade several studies demonstrated the utility of a chemical (GC/MS) and biological (bioassays/biomarkers) control of waste thermal recycling processes like pyrolysis or incineration treatment. In this paper, we report the results of our recent examinations on the possibility to apply various bioassays to supplementary methods for the present procedure.

  18. Properties of Concrete using Tanjung Bin Power Plant Coal Bottom Ash and Fly Ash

    Directory of Open Access Journals (Sweden)

    Abdulhameed Umar Abubakar

    2012-12-01

    Full Text Available Coal combustion by-products (CCPs have been around since man understood that burning coal generates electricity, and its utilization in concrete production for nearly a century. The concept of sustainable development only reawaken our consciousness to the huge amount of CCPs around us and the need for proper reutilization than the current method of disposal which has  severe consequences both to man and the environment. This paper presents the result of utilization of waste from thermal power plants to improve some engineering properties of concrete. Coal bottom ash (CBA and fly ash were utilized in partial replacement for fine aggregates and cement respectively. The results of compressive strength at 7, 28, 56 & 90 days curing are presented because of the pozzolanic reaction. Other properties investigated include physical properties, fresh concrete properties and density. The results showed that for a grade 35 concrete with a combination of CBA and fly ash can produce 28 day strength above 30 MPa.

  19. Quantification of the resource recovery potential of municipal solid waste incineration bottom ashes

    International Nuclear Information System (INIS)

    Highlights: • Ferrous and non-ferrous metals were quantified in MSWI bottom ashes. • Metal recovery system efficiencies for bottom ashes were estimated. • Total content of critical elements was determined in bottom ash samples. • Post-incineration recovery is not viable for most critical elements. - Abstract: Municipal solid waste incineration (MSWI) plays an important role in many European waste management systems. However, increasing focus on resource criticality has raised concern regarding the possible loss of critical resources through MSWI. The primary form of solid output from waste incinerators is bottom ashes (BAs), which also have important resource potential. Based on a full-scale Danish recovery facility, detailed material and substance flow analyses (MFA and SFA) were carried out, in order to characterise the resource recovery potential of Danish BA: (i) based on historical and experimental data, all individual flows (representing different grain size fractions) within the recovery facility were quantified, (ii) the resource potential of ferrous (Fe) and non-ferrous (NFe) metals as well as rare earth elements (REE) was determined, (iii) recovery efficiencies were quantified for scrap metal and (iv) resource potential variability and recovery efficiencies were quantified based on a range of ashes from different incinerators. Recovery efficiencies for Fe and NFe reached 85% and 61%, respectively, with the resource potential of metals in BA before recovery being 7.2%ww for Fe and 2.2%ww for NFe. Considerable non-recovered resource potential was found in fine fraction (below 2 mm), where approximately 12% of the total NFe potential in the BA were left. REEs were detected in the ashes, but the levels were two or three orders of magnitude lower than typical ore concentrations. The lack of REE enrichment in BAs indicated that the post-incineration recovery of these resources may not be a likely option with current technology. Based on these results

  20. Eco-friendly porous concrete using bottom ash aggregate for marine ranch application.

    Science.gov (United States)

    Lee, Byung Jae; Prabhu, G Ganesh; Lee, Bong Chun; Kim, Yun Yong

    2016-03-01

    This article presents the test results of an investigation carried out on the reuse of coal bottom ash aggregate as a substitute material for coarse aggregate in porous concrete production for marine ranch applications. The experimental parameters were the rate of bottom ash aggregate substitution (30%, 50% and 100%) and the target void ratio (15%, 20% and 25%). The cement-coated granular fertiliser was substituted into a bottom ash aggregate concrete mixture to improve marine ranch applications. The results of leaching tests revealed that the bottom ash aggregate has only a negligible amount of the ten deleterious substances specified in the Ministry of Environment - Enforcement Regulation of the Waste Management Act of Republic Korea. The large amount of bubbles/air gaps in the bottom ash aggregate increased the voids of the concrete mixtures in all target void ratios, and decreased the compressive strength of the porous concrete mixture; however, the mixture substituted with 30% and 10% of bottom ash aggregate and granular fertiliser, respectively, showed an equal strength to the control mixture. The sea water resistibility of the bottom ash aggregate substituted mixture was relatively equal to that of the control mixture, and also showed a great deal of improvement in the degree of marine organism adhesion compared with the control mixture. No fatality of fish was observed in the fish toxicity test, which suggested that bottom ash aggregate was a harmless material and that the combination of bottom ash aggregate and granular fertiliser with substitution rates of 30% and 10%, respectively, can be effectively used in porous concrete production for marine ranch application. PMID:26687102

  1. Copper speciation in municipal solid waste incinerator bottom ash leachates; Kopparformer i lakvatten fraan energiaskor

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, Susanna; Gustafsson, Jon Petter [Royal Inst. of Tech., Stockholm (Sweden); Schaik, Joris van; Berggren Kleja, Dan [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden); Hees, Patrick van [Oerebro Univ. (Sweden)

    2006-03-15

    The formation of copper (Cu) complexes with dissolved organic carbon (DOC) in bottom ash from municipal solid waste incineration (MSWI) may increase the total amount of Cu released but at the same time reduce its toxicity. In this study, DOC in a MSWI bottom ash leachate was characterized and the Cu-binding properties of different DOC fractions in the ash leachate and in a soil solution were studied. This knowledge may be used for improved environmental assessment of MSWI bottom ash in engineering applications. The Cu{sup 2+} activity at different pH values was measured potentiometrically using a Cu-ion selective electrode (Cu-ISE). Experimental copper complexation results were compared to speciation calculations made in Visual MINTEQ with the NICA-Donnan model and the Stockholm Humic Model (SHM). The MSWI bottom ash leachate contained a larger proportion of hydrophilic organic carbon than the investigated soil solution and other natural waters. The hydrophilic fraction of both samples showed Cu{sup 2+} binding properties similar to that of the bulk, cation-exchanged, leachate. For the ash leachate, the pH dependence of the Cu activity was not correctly captured by neither the SHM nor the NICA-Donnan model, but for the soil solution the model predictions of Cu speciation were in good agreement with the obtained results. The complex formation properties of the ash DOC appears to be less pH-dependent than what is assumed for DOC in natural waters. Hence, models calibrated for natural DOC may give inconsistent simulations of Cu-DOC complexation in MSWI bottom ash leachate. A Biotic Ligand Model for Daphnia Magna was used to provide an estimate of the copper concentrations at LC50 for a simulated bottom ash leachate. It was concluded that the Cu concentrations in certain bottom ash leachates are high enough to pose an ecotoxicological risk; however, after dilution and soil sorption, the risks for neighboring water bodies are most likely negligible. Three processes were

  2. Quality assurance of MSWI bottom ash. Environmental properties; Kvalitetssaekring av slaggrus. Miljoemaessiga egenskaper

    Energy Technology Data Exchange (ETDEWEB)

    Flyhammar, Peter [Lund Univ. (Sweden). Engineering Geology

    2006-04-15

    In Sweden, several hundred tonnes of MSWI bottom ash are generated annually at 29 incineration plants for municipal solid waste. So far bottom ash has mainly been disposed in to landfills or used as cover material in landfills or in other construction works at landfills. A few applications of bottom ash in construction works outside landfills have been reported. A large problem for the market of bottom ash and other secondary materials outside Swedish waste treatment plants is the lack of roles and regulations for a non-polluting use. During 2002 Hartlen and Groenholm presented a proposal to a system to assure the quality of bottom ash after homogenization and stabilization. They notice that the leaching of salts and metals to ground water constitutes the largest risk for the environment during use of bottom ash. Therefore, a quality assurance of environmental properties should be based on leaching tests. The aim of this project was to study how the control of environmental properties of bottom ash (at first hand leaching properties) earlier described in e.g. a product information sheet should be worked out. The starting-point has been a control system for bottom ash developed by Sysav. Different leaching tests illustrate however different aspects of the environmental properties, e.g. short-term and long-term leaching. Limit and target values for different variables could affect both the possibilities to use bottom ash as well as the sampling from storage heaps. We have chosen to investigate pH, availability and leached amount and the connection between these variables. the possibilities to use pH or the availability to assess both short-term and longterm leaching properties. how the number of subsamples that should be collected from a storage heap is affected by different control variables and quality requirements. how bottom ash is stabilized by today's storage technology and how the technology could be improved. Our sample test of bottom ash from Swedish

  3. Testing the possibility for reusing mswi bottom ash in Greenlandic road construction

    DEFF Research Database (Denmark)

    Kirkelund, Gunvor Marie; Jørgensen, Anders Stuhr; Villumsen, Arne

    2012-01-01

    smaller fractions (< 0.5 mm). The bearing capacity showed a CBR-value of 21.4%, which is acceptable for the intended use. The heavy metal content and leachable amount of heavy metals in the bottom ash were under the Danish guideline levels for reuse of contaminated waste for geotechnical purposes as......, which can influence the quality of MWSI residues. About 15,000 tons MSWI bottom ash is produced annually in Greenland and is disposed of at the open disposal sites without leachate collection or encapsulation. The MSWI bottom ash could have value as a secondary resource in construction work in Greenland....... This would contribute to solve the problem of disposal and possible related environmental problems in the vulnerable Greenlandic environment. In this study, MSWI bottom ash was collected from the disposal site in the town of Sisimiut in Western Greenland and characterized and tested for technical...

  4. Characterisation of MSWI bottom ash for potential use as subbase in Greenlandic road construction

    DEFF Research Database (Denmark)

    Kirkelund, Gunvor Marie; Jørgensen, Anders Stuhr; Ingeman-Nielsen, Thomas;

    2012-01-01

    The waste management situation in Greenland needs to be improved. Most waste in towns is incinerated with only limited separation prior to incineration and the bottom ash residue is disposed of at uncontrolled disposal sites. The bottom ash could be a valuable resource within the expansion of...... infrastructure due to increased oil and mineral exploitation. Thus, in this study MSWI bottom ash from a Greenlandic incinerator was tested for possible reuse as subbase in road construction. The mechanical properties (grain size distribution, wear resistance and bearing capacity) showed that the bottom ash was...... acceptable for reuse after some small adjustments in the grain size distribution to prevent frost sensitivity. Results obtained from heavy metal content and heavy metal leaching complied with the Danish guideline values for reuse of waste materials in construction. Leaching of Cu and Cr was high from small...

  5. Characteristics of fly ash and bottom ash from the municipal solid waste incineration plant in Shanghai

    International Nuclear Information System (INIS)

    Background: Incineration is an attractive method of energy production and waste reduction for the treatment of municipal solid waste (MSW). However, the secondary pollutants followed such as fly ash (FA), bottom ash (BA) from the waste incineration are always a concern. Yet few articles provide detailed information about the physical and chemical characteristics of trace elements in ash at the molecular level. Purpose: The elemental concentrations and microstructure characteristics of ash were investigated to understand the distribution and migration of the elements in MSW incineration process. Methods: The study of the characteristics of FA and BA from Shanghai MSW incineration plant was based on the concentrations of elements, water-soluble salts, microstructure, section-distribution of the elements in single particle, isotope ratio and chemical species of Pb, which were studied respectively by using synchrotron radiation X-ray fluorescence (SR-XRF), Ion Chromatography (IC), Scanning electron microscopy (SEM), X-ray energy dispersive microanalysis (EDX), Synchrotron radiation micro-beam X-ray fluorescence (μ-XRF), Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and X-ray absorption near-edge structure (XANES) spectra. Results: Mass concentrations of most metal elements in FA were higher than those in BA, especially Pb and Cd, which had been obviously enriched. FA particles were of relatively smaller size and rougher surface than those of BA, which brought easier adsorption of heavy metals in FA. The large enrichment factors of Pb, Cd, Cu and Zn indicated these elements were in extreme pollution state. Water-soluble salts in FA and BA mainly existed as chloride and sulfate of Ca, Na and K. The ion concentrations in FA were generally higher than those in BA. Results of μ-XRF suggested that Pb, Zn, Cu, Cr, Fe and Mn had nonuniform distributions and highly localized to some small regions in FA and BA. Isotope ratio of Pb in FA and BA was similar. Chemical

  6. Effect of accelerated carbonation and zero valent iron on metal leaching from bottom ash.

    Science.gov (United States)

    Nilsson, M; Andreas, L; Lagerkvist, A

    2016-05-01

    . The effects of Fe(0) addition can be related to binding of the studied elements to newly formed iron oxides. The effects of Fe(0) addition were often more distinct at pH values between 7 and 9, which indicates that a single treatment with only Fe addition would be less effective and a combined treatment is recommended. The pHstat results showed that accelerated carbonation in combination with Fe(0)(0) addition widens the pH range for low solubility of about one unit for several of the studied elements. This indicates that pre-treating the bottom ash with a combination of accelerated carbonation and Fe(0) addition makes the leaching properties of the ash less sensitive to pH changes that may occur during reuse. All in all, the addition of Fe(0) in combination with carbonation could be an effective pre-treatment method for decreasing the mobility of potentially harmful components in bottom ash. PMID:26786400

  7. Quality assurance of MSWI bottom ash. Environmental properties; Kvalitetssaekring av slaggrus. Miljoemaessiga egenskaper

    Energy Technology Data Exchange (ETDEWEB)

    Flyhammar, Peter [Lund Univ. (Sweden). Dept. of Engineering Geology

    2006-04-15

    In Sweden several hundred tonnes of MSWI bottom ash are generated annually at 29 incineration plants for municipal solid waste. So far bottom ash has mainly been disposed in to landfills or used as cover material in landfills or in other construction works at landfills. A few applications of bottom ash in construction works outside landfills have been reported. A large problem for the market of bottom ash and other secondary materials outside Swedish waste treatment plants is the lack of roles and regulations for a non-polluting use. During 2002 Hartlen and Groenholm (HG) presented a proposal to a system to assure the quality of bottom ash after homogenization and stabilization. A quality assurance of environmental properties should be based on leaching tests. The aim of this project was to study how the control of environmental properties of bottom ash earlier described in e.g. a product information sheet should be worked out. The starting-point has been a control system for bottom ash developed by the Sysav company. Different leaching tests illustrate however different aspects of the environmental properties, e.g. short-term and long-term leaching. Limit and target values for different variables could affect both the possibilities to use bottom ash as well as the sampling from storage heaps. We have chosen to investigate: pH, availability and leached amount and the connection between these variables; the possibilities to use pH or the availability to assess both short-term and long term leaching properties; how the number of subsamples that should be collected from a storage heap is affected by different control variables and quality requirements; how bottom ash is stabilized by today's storage technology and how the technology could be improved. Our sample test of bottom ash from Swedish incineration plants indicates that the availability of elements such as Cd, Cu, Cr, Ni, Pb and Zn in bottom ash usually is below Sysav's target values. Extreme values

  8. Aggregate material formulated with MSWI bottom ash and APC fly ash for use as secondary building material

    International Nuclear Information System (INIS)

    Highlights: ► A concrete formulation was optimized using Bottom Ash and APC ash. ► 10% of APC ash achieves good compromise between economic and performance aspects. ► The crushed concrete was evaluated as secondary building granular material. ► The environmental behavior allows its use as secondary material. ► The abrasion resistance is not good enough for its use as a road sub-base material. - Abstract: The main goal of this paper is to obtain a granular material formulated with Municipal Solid Waste Incineration (MSWI) bottom ash (BA) and air pollution control (APC) fly ash to be used as secondary building material. Previously, an optimum concrete mixture using both MSWI residues as aggregates was formulated. A compromise between the environmental behavior whilst maximizing the reuse of APC fly ash was considered and assessed. Unconfined compressive strength and abrasion resistance values were measured in order to evaluate the mechanical properties. From these results, the granular mixture was not suited for certain applications owing to the high BA/APC fly ash content and low cement percentages used to reduce the costs of the final product. Nevertheless, the leaching test performed showed that the concentrations of all heavy metals were below the limits established by the current Catalan legislation for their reutilization. Therefore, the material studied might be mainly used in embankments, where high mechanical properties are not needed and environmental safety is assured

  9. Heavy Metal Contamination of Soils around a Hospital Waste Incinerator Bottom Ash Dumps Site

    Directory of Open Access Journals (Sweden)

    M. Adama

    2016-01-01

    Full Text Available Waste incineration is the main waste management strategy used in treating hospital waste in many developing countries. However, the release of dioxins, POPs, and heavy metals in fly and bottom ash poses environmental and public health concerns. To determine heavy metal (Hg, Pb, Cd, Cr, and Ag in levels in incinerator bottom ash and soils 100 m around the incinerator bottom ash dump site, ash samples and surrounding soil samples were collected at 20 m, 40 m, 60 m, 80 m, 100 m, and 1,200 m from incinerator. These were analyzed using the absorption spectrophotometer method. The geoaccumulation (Igeo and pollution load indices (PLI were used to assess the level of heavy metal contamination of surrounding soils. The study revealed high concentrations in mg/kg for, Zn (16417.69, Pb (143.80, Cr (99.30, and Cd (7.54 in bottom ash and these were above allowable limits for disposal in landfill. The study also found soils within 60 m radius of the incinerator to be polluted with the metals. It is recommended that health care waste managers be educated on the implication of improper management of incinerator bottom ash and regulators monitor hospital waste incinerator sites.

  10. Aluminium recovery from waste incineration bottom ash, and its oxidation level.

    Science.gov (United States)

    Biganzoli, Laura; Grosso, Mario

    2013-09-01

    The recovery of aluminium (Al) scraps from waste incineration bottom ash is becoming a common practice in waste management. However, during the incineration process, Al in the waste undergoes oxidation processes that reduce its recycling potential. This article investigates the behaviour of Al scraps in the furnace of two selected grate-fired waste-to-energy plants and the amount recoverable from the bottom ash. About 21-23% of the Al fed to the furnace with the residual waste was recovered and potentially recycled from the bottom ash. Out of this amount, 76-87% was found in the bottom ash fraction above 5 mm and thus can be recovered with standard eddy current separation technology. These values depend on the characteristics and the mechanical strength of the Al items in the residual waste. Considering Al packaging materials, about 81% of the Al in cans can be recovered from the bottom ash as an ingot, but this amount decreases to 51% for trays, 27% for a mix of aluminium and poly-laminated foils and 47% for paper-laminated foils. This shows that the recovery of Al from the incineration residues increases proportionally to the thickness of the packaging. PMID:23831779

  11. Effects of substrate induced respiration on the stability of bottom ash in landfill cover environment.

    Science.gov (United States)

    Ilyas, A; Lovat, E; Persson, K M

    2014-12-01

    The municipal solid waste incineration bottom ash is being increasingly used to construct landfill covers in Sweden. In post-closure, owing to increased cover infiltration, the percolating water can add external organic matter to bottom ash. The addition and subsequent degradation of this external organic matter can affect metal mobility through complexation and change in redox conditions. However, the impacts of such external organic matter addition on bottom ash stability have not been fully evaluated yet. Therefore, the objective of this study was to evaluate the impact of external organic matter on bottom ash respiration and metal leaching. The samples of weathered bottom ash were mixed with oven dried and digested wastewater sludge (1%-5% by weight). The aerobic respiration activity (AT4), as well as the leaching of metals, was tested with the help of respiration and batch leaching tests. The respiration and heavy metal leaching increased linearly with the external organic matter addition. Based on the results, it was concluded that the external organic matter addition would negatively affect the quality of landfill cover drainage. PMID:25395160

  12. The Utilization of Bottom Ash Coal for Briquette Products by Adding Teak Leaves Charcoal, Coconut Shell Charcoal, and Rice Husk Charcoal

    Directory of Open Access Journals (Sweden)

    Syafrudin Syafrudin

    2015-01-01

    Full Text Available The limitations of the availability of energy sources especially fuel oil has become a serious threat for the society. The use of coal for energy source as the replacement of fuel oil, in one hand, is very profitable, but on the other hand, will cause problem which is the coal ash residue. This coal ash is a by-product of coal combustion. This coal ash contains bottom ash. Through this observation, the bottom ash can be processed to be charcoal if added by teak leaves, coconut shell, and rice husk. Also, this observation needs to add binder materials for further processing in order to form briquette. It can be used as alternative fuel, the utilization of bottom ash and biomass will give positive impact to the environment. This observation was conducted by using compositions such as bottom ash, teak leaves, coconut shell, and rice husk. The treatment was using comparison 100%:0% ; 80%:20% ; 60%:40% ; 50%:50% ; 40%:60% ; 20%:80% ; 0%:100%. The result that the best briquette was on the composition of 20% bottom ash : 80% coconut shell. The characteristic values from that composition were moisture content of 3.45%, ash content of 17,32%, calorific value of 7.945,72 Cal/gr, compressive strength of 2,18 kg/cm2, level of CO of 105 mg/m3, and heavy metals Cu of 29,83 µg/g and  Zn 32,99 µg/g. The characteristic value from each briquette composition treatment showed that the increasing usage proportion of biomass as added material for briquette was able to increase its moisture content and calorific value. Besides, it is also able to decrease its ash content and compressive strength

  13. Single and Tertiary System Dye Removal from Aqueous Solution Using Bottom Ash: Kinetic and Isotherm Studies

    Directory of Open Access Journals (Sweden)

    R. Gandhimathi

    2012-01-01

    Full Text Available This paper investigates the ability of Bottom ash to adsorb three cationic dyes from aqueous solution in single and tertiary systems. Crystal Violet (CV, Methylene Blue (MB and Malachite Green (MG were used as cationic dye models. The surface characteristics of Bottom ash were investigated using Fourier Transform Infrared (FTIR. Pseudo second order model was fitted better than Pseudo First order model for all system of MG, MB and CV. From the isotherm study, the adsorption capacity increased in the order of MB< MGBottom ash decreases in tertiary system as compared to single system. Langmuir and Freundlich isotherm models were fitted for all system of dyes. Freundlich isotherm model found to be the best fit for all systems.

  14. Co-sintering of treated APC-residues with bottom ash

    DEFF Research Database (Denmark)

    Bergfeldt, B.; Jensen, Dorthe Lærke; Vehlow, J.;

    2001-01-01

    Air pollution control residues stabilised by means of the Ferrox process can be sager disposed of due to lower contents of soluble salts and lesssoluble heavy metals stabilised in iron oxides. Co-combustion tests in the Karlsruhe test incinerator TAMARA were carried out in order to investigate the...... influence of co-sintering of Ferrox products with bottom ashes on the quality of the residues and the effects on the combustion process. Only few elements showed higher concentrations in the bottom ashes of these co-combustion tests compared to reference tests. No significant effect on the leaching...... behaviour of the bottom ashes could be found. During the co-combustion process an increase in SO2 concentrations in the raw gas and slightly lower temperatures in the fuel bed could be observed....

  15. Recovery of Multi-Metallic Components from Bottom Ash by Smelting Reduction Under Plasma Environment

    Science.gov (United States)

    Mandal, Arup Kumar; Sinha, Om Prakash

    2016-02-01

    A new concept for maintaining inert atmosphere with high temperature ~1973 K (1700 °C) inside the furnace during smelting reduction was described, in which recovery of metallic values from wastes was done in the presence of metal bath which acts as a solvent. Nitrogen plasma arc was generated by passing current and nitrogen gas through a hollow graphite electrode. In this way, the heat for reduction reactions and melting of metal and slag phases under inert atmosphere was maintained. The mixture of bottom ash and carbonaceous reducing agent was fed in the form of pellets near the plasma zone above the liquid iron bath, used for the absorption of reduced metals after reduction of oxides present in the wastes. Percent recovery of metallic values and different consumption parameters were calculated. It was observed that aluminum, iron, and silicon could be recovered effectively from the wastes.

  16. The Laconia, New Hampshire bottom ash paving project: Volume 3, Physical Performance Testing Report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    Bottom ash is the principal waste stream from the combustion of municipal solid waste (MSW). It is comprised of grate ash (97%), the slag material discharged at the end of the grate system, and grate sifting (3%), the material that melts or falls through the grate structure. This project was conducted to demonstrate the feasibility of using municipal solid waste grate ash as an aggregate substitute in the construction of a pavement binder course for a portion of Rt. 3 in Laconia, New Hampshire. The research was conducted over a two year period during 1993 and 1994. This study is the culmination of an earlier two year characterization study between 1990 and 1992 that documented the physical and environmental characteristics of the bottom ash as it was produced at the Concord, N.H. waste-to-energy (@) facility and used in an asphaltic binder course. Together, these two studies provide a complete evaluation of the potential for using grate ash or bottom ash in asphalt binder course or as recycled asphalt pavement (RAP) in base courses in pavements.

  17. Quality assurance of MSWI bottom ash. Environmental properties; Kvalitetssaekring av slaggrus. Miljoemaessiga egenskaper

    Energy Technology Data Exchange (ETDEWEB)

    Flyhammar, Peter [Lund Univ. (Sweden). Engineering Geology

    2006-04-15

    In Sweden, several hundred tonnes of MSWI bottom ash are generated annually at 29 incineration plants for municipal solid waste. So far bottom ash has mainly been disposed in to landfills or used as cover material in landfills or in other construction works at landfills. A few applications of bottom ash in construction works outside landfills have been reported. A large problem for the market of bottom ash and other secondary materials outside Swedish waste treatment plants is the lack of roles and regulations for a non-polluting use. During 2002 Hartlen and Groenholm presented a proposal to a system to assure the quality of bottom ash after homogenization and stabilization. They notice that the leaching of salts and metals to ground water constitutes the largest risk for the environment during use of bottom ash. Therefore, a quality assurance of environmental properties should be based on leaching tests. The aim of this project was to study how the control of environmental properties of bottom ash (at first hand leaching properties) earlier described in e.g. a product information sheet should be worked out. The starting-point has been a control system for bottom ash developed by Sysav. Different leaching tests illustrate however different aspects of the environmental properties, e.g. short-term and long-term leaching. Limit and target values for different variables could affect both the possibilities to use bottom ash as well as the sampling from storage heaps. We have chosen to investigate pH, availability and leached amount and the connection between these variables. the possibilities to use pH or the availability to assess both short-term and longterm leaching properties. how the number of subsamples that should be collected from a storage heap is affected by different control variables and quality requirements. how bottom ash is stabilized by today's storage technology and how the technology could be improved. Our sample test of bottom ash from Swedish

  18. Quality assurance of MSWI bottom ash. Environmental properties; Kvalitetssaekring av slaggrus. Miljoemaessiga egenskaper

    Energy Technology Data Exchange (ETDEWEB)

    Flyhammar, Peter [Lund Univ. (Sweden). Dept. of Engineering Geology

    2006-04-15

    In Sweden several hundred tonnes of MSWI bottom ash are generated annually at 29 incineration plants for municipal solid waste. So far bottom ash has mainly been disposed in to landfills or used as cover material in landfills or in other construction works at landfills. A few applications of bottom ash in construction works outside landfills have been reported. A large problem for the market of bottom ash and other secondary materials outside Swedish waste treatment plants is the lack of roles and regulations for a non-polluting use. During 2002 Hartlen and Groenholm (HG) presented a proposal to a system to assure the quality of bottom ash after homogenization and stabilization. A quality assurance of environmental properties should be based on leaching tests. The aim of this project was to study how the control of environmental properties of bottom ash earlier described in e.g. a product information sheet should be worked out. The starting-point has been a control system for bottom ash developed by the Sysav company. Different leaching tests illustrate however different aspects of the environmental properties, e.g. short-term and long-term leaching. Limit and target values for different variables could affect both the possibilities to use bottom ash as well as the sampling from storage heaps. We have chosen to investigate: pH, availability and leached amount and the connection between these variables; the possibilities to use pH or the availability to assess both short-term and long term leaching properties; how the number of subsamples that should be collected from a storage heap is affected by different control variables and quality requirements; how bottom ash is stabilized by today's storage technology and how the technology could be improved. Our sample test of bottom ash from Swedish incineration plants indicates that the availability of elements such as Cd, Cu, Cr, Ni, Pb and Zn in bottom ash usually is below Sysav's target values. Extreme values

  19. Nanominerals and nanoparticles in feed coal and bottom ash: implications for human health effects.

    Science.gov (United States)

    Silva, Luis F O; da Boit, Kátia M

    2011-03-01

    Environmental and human health risk assessments of nanoparticle effects from coal and bottom ash require thorough characterisation of nanoparticles and their aggregates. In this manuscript, we expand the study of human exposure to nanosized particles from coal combustion sources (typically pyrrhotite formation. The presence of iron oxide nanocrystals mixed with silicate glass particles emphasises the complexity of coal and bottom ash micromineralogy. Given the potentially bioreactive nature of such transition metal-bearing materials, there is likely to be an increased health risk associated with their inhalation. PMID:20422282

  20. Characterization of MSWI Bottom Ash and Assessment of Resource Recovery Potential

    OpenAIRE

    Šyc, Michal

    2015-01-01

    Bottom ash from municipal solid waste incineration contains valuable components that can be recycled as secondary materials, such as ferrous and non-ferrous metals, rare earth elements, glass etc. Metal-free mineral fraction is reusable in construction industry. The composition of bottom ash is highly dependent on the composition of incinerated waste but in average can be around 5–13 % ferrous metals, 2–5 % non-ferrous metals, 15–30 % glass and ceramics, 1–5 % unburned organics and 50–70 % mi...

  1. Quality criteria for bottom ashes for civil construction. Part II Technical characteristics of bottom ashes; Kvalitetskriterier foer bottenaskor till vaegoch anlaeggningsbyggnad. Etapp II Bottenaskors tekniska egenskaper

    Energy Technology Data Exchange (ETDEWEB)

    Bahr, Bo von; Loorents, Karl-Johan; Ekvall, Annika; Arvidsson, Haakan [SP Swedish National Testing and Research Inst., Boraas (Sweden)

    2006-01-15

    This report is the presentation of the second of two stages. This stage deals mainly with the testing of three different types of ashes and the evaluation and suitability of the chosen test methods. The project only relates to the technical aspects of ashes. The report is written in such a way that both ash owners (e.g. Energy companies) and those who build roads and constructions will find it meaningful. All test methods that are used for traditional materials (gravel and crushed rock) is not fitting for ashes. New test methods for some properties that will be tested must therefore be presented, tested practically and evaluated. The project encompasses both road and construction building but has a focus on road construction since there the highest and comprising demands are defined. Three bottom ashes of different types have been studied regarding some tenfold mechanical/physical parameters, essential for the functionality of the ash as a construction material. An important conclusion is that ash is from a functionality and characterisation point of view, an undefined concept that encloses materials with widely different properties. Despite that only three ashes have been looked into the range of results are varying large for some properties. This is especially true for the loose bulk density, water absorption and grain size distribution. It is also clear that some of the standard test methods for aggregates need to be exchanged by other methods, which are more adapted to alternative materials. One such example is water absorption, a property that further influences frost resistance, frost heave and such. All the proposed test methods that been used in the project is considered fitting for its purpose. The test methods can be divided into two categories the ones that yield easy assessable results and those that yield results hard to appraise. To the first group belong grain size distribution, loose bulk density, thermal conductivity, permeability and frost heave

  2. Adsorption and desorption characteristics of crystal violet in bottom ash column

    Directory of Open Access Journals (Sweden)

    Puthiya Veetil Nidheesh

    2012-06-01

    Full Text Available This study described adsorption of Crystal Violet (CV by bottom ash in fixed-bed column mode. Equilibrium of adsorption was studied in batch mode for finding adsorption capacity of bottom ash. In fixed bed column adsorption, the effects of bed height, feed flow rate, and initial concentration were studied by assessing breakthrough curve. The slope of the breakthrough curve decreased with increasing bed height. The breakthrough time and exhaustion time were decreased with increasing influent CV concentration and flow rates. The effect of bed depth, flow rate and CV concentration on the adsorption column design parameters were analyzed. Bed depth service time (BDST model was applied for analysis of crystal violet adsorption in the column. The adsorption capacity of bottom ash was calculated at 10% breakthrough point for different flow rates and concentrations. Desorption studies reveals that recovery of CV from bottom ash was effective by using CH3COOH than H2SO4, NaOH, HCl and NaCl solutions.

  3. Carbon speciation in municipal solid waste incinerator (MSWI) bottom ash in relation to facilitated metal leaching

    NARCIS (Netherlands)

    Zomeren, van A.; Comans, R.N.J.

    2009-01-01

    The release of inorganic and organic contaminants from municipal solid waste incinerator (MSWI) bottom ash is controlled to a large extent by the release of dissolved organic carbon (DOC), and in particular by the reactive humic (HA) and fulvic acids (FA) subfractions of DOC. The properties of organ

  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. Mechanical and leaching properties of blended systems containing OPC and incinerator bottom ash

    Energy Technology Data Exchange (ETDEWEB)

    Onori, R.; Polettini, A.; Pomi, R. [Rome Univ. (Italy). Dept. of Hydraulics, Transportation and Roads

    2010-07-01

    Chemical and mechanical activation processes were applied to improve the reactivity of incinerator bottom ash in Portland cement mixtures. Sodium hydroxide (NaOH), potassium hydroxide (KOH), calcium chloride (CaCI{sub 2}) and calcium sulfate (CaSO{sub 4}) activators were used in experiments conducted to determine bottom ash content, activator type, and activator dosages for varying amounts of cement and bottom ash. The study evaluated the evolution of mechanical strength and the leaching behaviour of both major and trace elements from the activated bottom ash and Portland cement mixtures. Results of the study showed that the use of CaCI{sub 2} improved the hydration process in the mixtures. A positive effect on mechanical strength was noted when CaSO{sub 4} was used as an activator. Trace metals were efficiently immobilized within the hardened materials for all the tested activators. Geochemical modelling was used to determine the main hydration phases of the leaching solutions. No mineral phases were identified as potential solubility-controlling solids. Results of the study indicated the presence of heavy metals as complex phase assemblages in the hardened materials. 40 refs., 2 tabs., 8 figs.

  6. The Properties of Special Concrete Using Washed Bottom Ash (WBA as Partial Sand Replacement

    Directory of Open Access Journals (Sweden)

    Mohd Syahrul Hisyam Mohd Sani

    2011-07-01

    Full Text Available This paper presents the use of Washed Bottom Ash (WBA as fine aggregate in special concrete. The WBA is a waste material that is taken from electric power plant and the source material is called as bottom ash. To substitute the amount of carbon usage in concrete the bottom ash was utilized and fully submerged in water for 3 days to produce as WBA with low carbon composition. The aim of the study is to investigate the feasibility and potential use of washed bottom ash in concreting and concrete applications. The results of the physical and chemical properties of WBA were discussed. Different concrete mixes with constant water to cement ratio of 0.55 were prepared with WBA in different proportions as well as one control mixed proportion. The mechanical properties of special concrete with 30% WBA replacement by weight of natural sand is found to be an optimum usage in concrete in order to get a favourable strength and good strength development pattern over the increment ages.

  7. Leaching from waste incineration bottom ashes treated in a rotary kiln

    DEFF Research Database (Denmark)

    Hyks, Jiri; Nesterov, Igor; Mogensen, Erhardt;

    2011-01-01

    Leaching from municipal solid waste incineration bottom ash treated in a rotary kiln was quantified using a combination of lab-scale leaching experiments and geochemical modelling. Thermal treatment in the rotary kiln had no significant effect on the leaching of Al, Ba, Ca, Mg, Si, Sr, Zn, sulfate...

  8. Characteristics of residual organics in municipal solid waste incinerator bottom ash.

    Science.gov (United States)

    Lin, Yen-Ching; Yen, Jui-Hung; Lateef, Shaik Khaja; Hong, Pui-Kwan Andy; Lin, Cheng-Fang

    2010-10-15

    Although heavy metals in bottom ash have been a primary issue in resource recovery of municipal solid waste incinerator residues in past decades, less studied are potentially toxic and odorous organic fractions that exist as they have not been completely oxidized during the mass burn process. Using supercritical fluid extraction (SFE) and soxtec extraction (SE) techniques, this study investigated the characteristics of un-oxidized organic residues contained in bottom ash from three municipal solid waste incinerators in Taiwan during 2008-2009. All together 99 organics were identified in bottom ash samples using gas chromatography-mass spectrometry (GC-MS). Among the identified organics, aromatic compounds were most frequently detected. No polycyclic aromatic hydrocarbons were extracted by SFE or SE. Several phthalates (e.g., phthalic acid isobutyl tridec-2-yn-1-yl ester, dibutyl phthalate and 2-butoxyethyl butyl benzene-1,2-dicarboxylate), organic phosphates (e.g., octicizer and phosphoric acid isodecyl diphenyl ester), and aromatics and amines including pyridine, quinoline derivatives, chloro- and cyano-organics were successfully extracted. Aromatic amines (e.g., 1-nitro-9,10-dioxo-9,10-dihydro-anthracene-2-carboxylic acid diethylamide and 3-bromo-N-(4-bromo-2-chlorophenyl)-propanamide) and aromatic compounds (other than amines) (e.g., 7-chloro-4-methoxy-3-methylquinoline and 2,3-dihydro-N-hydroxy-4-methoxy-3,3-dimethyl indole-2-one) are probably the major odorous compounds in bottom ash. This work identifies organic pollutants in incinerated bottom ash that have received far less attention than their heavy metals counterpart. PMID:20605069

  9. Effect of ferrous metal presence on lead leaching in municipal waste incineration bottom ashes.

    Science.gov (United States)

    Oehmig, Wesley N; Roessler, Justin G; Zhang, Jianye; Townsend, Timothy G

    2015-01-01

    The recovery of ferrous and non-ferrous metals from waste to energy (WTE) ash continues to advance as the sale of removed metals improves the economics of waste combustion. Published literature suggests that Fe and Fe oxides play a role in suppressing Pb leaching in the Toxicity Characteristic Leaching Procedure (TCLP); further removal of ferrous metals from WTE ashes may facilitate higher Pb leaching under the TCLP. Eight WTE bottom ash size-fractions, from three facilities, were evaluated to assess the effect of metallic Fe addition and ferrous metal removal on TCLP leaching. Metallic Fe addition was demonstrated to reduce Pb leaching; the removal of ferrous metals by magnet resulted in a decrease in total available Pb (mg/kg) in most ash samples, yet Pb leachability increased in 5 of 6 ash samples. The research points to two chemical mechanisms to explain these results: redox interactions between Pb and Fe and the sorption of soluble Pb onto Fe oxide surfaces, as well as the effect of the leachate pH before and after metals recovery. The findings presented here indicate that generators, processors, and regulators of ash should be aware of the impact ferrous metal removal may have on Pb leaching, as a substantial increase in leaching may have significant implications regarding the management of WTE ashes. PMID:25464288

  10. Antimony leaching from MSWI bottom ash: modelling of the effect of pH and carbonation.

    Science.gov (United States)

    Cornelis, Geert; Van Gerven, Tom; Vandecasteele, Carlo

    2012-02-01

    Development of treatment methods to reduce Sb leaching from municipal solid waste incinerator (MSWI) bottom ash, such as accelerated carbonation, is being complicated by insufficient understanding of Sb geochemistry. The leaching of antimonate (Sb(V)) and antimonite (Sb(III)) in MSWI bottom was studied as a function of pH and degree of carbonation. While total (Sb(V)+Sb(III)) leaching was lowest (1.2 mg kg(-1)) at the natural pH (i.e. 10.6) of uncarbonated bottom ash, HPLC-ICP-MS analysis showed that acidification and carbonation increased Sb(V) leaching, but decreased Sb(III) leaching, probably because Sb(III)(OH)(4)(-) became less stable. PHREEQC geochemical modelling suggested that Sb(V) concentrations approached equilibrium with the romeites, i.e. calcium antimonates, Ca(1.13)Sb(2)(OH)(0.26)·0.74H(2)O at pH=10.6 and Ca[Sb(OH)(6)](2) at pH=8. It is hypothesised that not interaction with ettringite but dissolution of romeite controls antimonate leaching in the pH range 8-11 in MSWI bottom ash, because while Ca is preferentially leached from romeite, the mineral structures containing more Ca at higher pH are less soluble. A model was proposed where acidification and carbonation both lead to lower Ca(2+) and/or hydroxyl concentration, which removes Ca(2+) and hydroxyls from the romeite structure and leads to comparably higher Sb(V) concentration in equilibrium with romeite. Sb solubility depends on pH and Ca(2+) availability in this model, which has implications for bottom ash valorisation and risk assessment. PMID:22035902

  11. Modelling of landfill gas adsorption with bottom ash for utilization of renewable energy

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Chen

    2011-10-06

    Energy crisis, environment pollution and climate change are the serious challenges to people worldwide. In the 21st century, human being is trend to research new technology of renewable energy, so as to slow down global warming and develop society in an environmentally sustainable method. Landfill gas, produced by biodegradable municipal solid waste in landfill, is a renewable energy source. In this work, landfill gas utilization for energy generation is introduced. Landfill gas is able to produce hydrogen by steam reforming reactions. There is a steam reformer equipment in the fuel cells system. A sewage plant of Cologne in Germany has run the Phosphoric Acid Fuel Cells power station with biogas for more than 50,000 hours successfully. Landfill gas thus may be used as fuel for electricity generation via fuel cells system. For the purpose of explaining the possibility of landfill gas utilization via fuel cells, the thermodynamics of landfill gas steam reforming are discussed by simulations. In practice, the methane-riched gas can be obtained by landfill gas purification and upgrading. This work investigate a new method for upgrading-landfill gas adsorption with bottom ash experimentally. Bottom ash is a by-product of municipal solid waste incineration, some of its physical and chemical properties are analysed in this work. The landfill gas adsorption experimental data show bottom ash can be used as a potential adsorbent for landfill gas adsorption to remove CO{sub 2}. In addition, the alkalinity of bottom ash eluate can be reduced in these adsorption processes. Therefore, the interactions between landfill gas and bottom ash can be explained by series reactions accordingly. Furthermore, a conceptual model involving landfill gas adsorption with bottom ash is developed. In this thesis, the parameters of landfill gas adsorption equilibrium equations can be obtained by fitting experimental data. On the other hand, these functions can be deduced with theoretical approach

  12. Biomass gasification bottom ash as a source of CaO catalyst for biodiesel production via transesterification of palm oil

    International Nuclear Information System (INIS)

    Highlights: • CaO catalyst was successfully developed from wood gasification bottom ash. • CaCO3 in bottom ash can be converted to CaO catalyst by calcination. • CaO catalysts derived from bottom ash exhibited high activity towards transesterification. • CaO catalysts derived from bottom ash can be reutilized up to four times. - Abstract: The main aim of this research is to develop environmentally and economically benign heterogeneous catalysts for biodiesel production via transesterification of palm oil. For this propose, calcium oxide (CaO) catalyst has been developed from bottom ash waste arising from woody biomass gasification. Calcium carbonate was found to be the main component in bottom ash and can be transformed into the active CaO catalyst by simple calcination at 800 °C without any chemical treatment. The obtained CaO catalysts exhibit high biodiesel production activity, over 90% yield of methyl ester can be achieved at the optimized reaction condition. Experimental kinetic data fit well the pseudo-first order kinetic model. The activation energy (Ea) of the transesterification reaction was calculated to be 83.9 kJ mol−1. Moreover, the CaO catalysts derived from woody biomass gasification bottom ash can be reutilized up to four times, offering the efficient and low-cost CaO catalysts which could make biodiesel production process more economic and environmental friendly

  13. Phosphorus Treated Coal Combustion Products (CCP-bottom ash) as an Agricultural Source of Phosphorus

    Science.gov (United States)

    Junfeng, Shen; Powell, M. A.; Hayden, D. B.

    Coal combustion products (CCP or "ash") have been seen to be beneficial for improving soil quality and increasing vegetative yields. Owing to their structure with more holes, they are also potential carriers of plant nutrients. The bottom ash from the Lambton Generating Station, Sarnia, Ontario, Canada was treated for 66 hours in 0.10 mol/L P solutions prepared from NaH 2PO 4, which resulted in the ash adsorbing 784 µg/g of phosphorus. The ash was mixed with quartz sand and/or non P-loaded ash from the same source to provide a set of growth media that contained 10%, 25%, 50%, 75%, and 100% of the recommended dose of P (50 µg/g) for maize. Biomass yields at 26, 34, and 46 days after planting were compared with control (non-doped ash) and fertilized with 0-20-0 fertilizer. In general, growth media containing between 25% and 100% of the recommended P dose performed as well or better than the fertilized trials. 46 days after planting, the shoot fresh weight for the 50%, 75%, and 100% doped media were 39.46%, 42.73%, and 46.13%, respectively, greater compared to fertilized trials. The shoot dry weight increased by 29.71%, 13.39%, and 28.87%, respectively. Also, root fresh and dry weight increased averagely by 16.62% and 14.03%. These results implied that coal ashes are a better carrier for P uptaking, and P-loaded ash can be a good additive for sand soil improvement.

  14. Analysis of Composition of Bottom Ash from Municipal Solid Waste Incineration Plants.

    Czech Academy of Sciences Publication Activity Database

    Krausová, Aneta; Šyc, Michal; Kameníková, Petra; Zach, Boleslav; Pohořelý, Michael; Svoboda, Karel; Punčochář, Miroslav

    Vienna: Christian Dopler Laboratory, 2015 - (Lederer, J.; Laner, D.; Rechberger, H.; Fellner, J.), s. 159-162 ISBN 978-3-85234-132-3. [International Workshop Mining the Technosphere "Drivers and Barriers, Challenges and Opportunities". Vienna (AT), 01.10.2015-02.10.2015] R&D Projects: GA TA ČR TE02000236 Institutional support: RVO:67985858 Keywords : municipal solid waste incineration * bottom ash * analysis Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  15. Analysis of Composition of Bottom Ash from Municipal Solid Waste Incineration Plants.

    OpenAIRE

    Krausová, A. (Aneta); Šyc, M. (Michal); Kameníková, P. (Petra); Zach, B. (Boleslav); Pohořelý, M. (Michael); Svoboda, K.; Punčochář, M.

    2015-01-01

    Bottom ash (BA) from municipal solid waste incineration (MSWI) contains valuable components that can be recycled such as ferrous and non-ferrous metals. Metal-free mineral fraction can be used in building industry. We analysed BA samples from two MSWI plants with the aim of characterising their composition. The BA samples were sieved into eight size fractions. With the exception of the smallest fraction (under 2 mm), the size fractions were sorted using magnetic separation, manual separation ...

  16. Characterization of MSWI Bottom Ash and Assessment of Resource Recovery Potential

    Czech Academy of Sciences Publication Activity Database

    Šyc, Michal; Kameníková, Petra; Krausová, Aneta; Zach, Boleslav; Pohořelý, Michael; Svoboda, Karel; Punčochář, Miroslav

    Ostrava: VŠB - Technical University of Ostrava, 2015 - (Čablík, V.), s. 209-213 ISBN 978-80-248-3753-6. [Conference on Environment and Mineral Processing /19./. Ostrava (CZ), 04.06.2015-06.06.2015] R&D Projects: GA TA ČR TE02000236 Institutional support: RVO:67985858 Keywords : mswi * bottom ash * metal recovery Subject RIV: CI - Industrial Chemistry, Chemical Engineering http://hdl.handle.net/11104/0252271

  17. 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

  18. Resource Recovery Potential of the Bottom Ash from Municipal Solid Waste Incineration in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Šyc, Michal; Kameníková, Petra; Svoboda, Karel; Krausová, Aneta; Pohořelý, Michael; Zach, Boleslav; Punčochář, Miroslav

    Padova: EuroWaste, 2015 - (Cossu, R.; He, P.; Kjeldsen, P.; Matsufuji, Y.; Reinhart, D.; Stegmann, R.) ISBN 9788862650212. [International Waste Management and Landfill Symposium /15./. S. Margherita di Pula, Cagliari (IT), 05.10.2015-09.10.2015] R&D Projects: GA TA ČR TE02000236 Institutional support: RVO:67985858 Keywords : solid waste incineration * bottom ash * resource recovery Subject RIV: CI - Industrial Chemistry, Chemical Engineering http://hdl.handle.net/11104/0252159

  19. Adsorption of Crystal Violet Dye from Aqueous Solution onto Zeolites from Coal Fly and Bottom Ashes

    Directory of Open Access Journals (Sweden)

    Tharcila Colachite Rodrigues Bertolini

    2013-11-01

    Full Text Available The adsorption of the cationic dye Crystal Violet (CV over zeolites from coal fly ash (ZFA and bottom ash (ZBA was evaluated. The coal fly ash (CFA and the coal bottom ash (CBA used in the synthesis of the zeolites by alkaline hydrothermal treatment were collected in Jorge Lacerda coal-fired power plant located at Capivari de Baixo County, in Santa Catarina State, Brazil. The zeolitic materials were characterized predominantly as hydroxy-sodalite and X. The dye adsorption equilibrium was reached after 10 min for ZFA and ZBA. The kinetics studies indicated that the adsorption followed the pseudo-second order kinetics and that surface adsorption and intraparticle diffusion were involved in the adsorption mechanism for both the adsorbents. The equilibrium data of ZFA was found to best fit to the Langmuir model, while ZBA was best explained by the Freundlich model. The maximum adsorption capacities were 19.6 mg g-1 for the CV/ZFA and 17.6 mg g-1 for the CV/ZBA.

  20. Chemical activation in view of MSWI bottom ash recycling in cement-based systems.

    Science.gov (United States)

    Polettini, A; Pomi, R; Fortuna, E

    2009-03-15

    In the present study, the feasibility of recycling incinerator bottom ash in cementitious systems by means of chemical activation was investigated. Different Na-, K- and Ca-based hydroxides and salts were selected for the experiments on the basis of their recognized effects on activation of typical pozzolanic materials. The evolution of mechanical properties of bottom ash/Portland cement mixtures and the leaching of trace metals from the materials were a matter of major concern. The experiments were arranged according to a full factorial design, which also allowed to derive a predictive model for unconfined compressive strength as affected by bottom ash content as well as activator type and dosage. Among the activators tested, calcium chloride was found to affect mechanical strength far more positively than the other species used, at the same time ensuring low metal release from the material. On the other hand, the use of potassium sulfate was observed to cause a significant increase in metal leaching at pHettringite as soon as it converted into monosulfate over time. PMID:18632208

  1. Characterization of alkali-activated thermally treated incinerator bottom ash.

    Science.gov (United States)

    Qiao, X C; Tyrer, M; Poon, C S; Cheeseman, C R

    2008-01-01

    The fine fraction (materials have been activated with Ca(OH)(2) (10 wt%) and the setting times and compressive strengths at different curing times measured. In addition to decomposition of CaCO(3) to CaO, thermal treatment increases the content of gehlenite (Ca(2)Al(2)SiO(7)), wollastonite (CaSiO(3)) and mayenite (Ca(12)Al(14)O(33)). Thermally treated samples were significantly more reactive than milled IBA and heating to 700 degrees C produced a material which rapidly set. Silica, gehlenite and wollastonite were the main crystalline phases present in hydrated samples and a mixed sulphate-carbonate AFm-type phase (Ca(4)Al(2)O(6)(CO(3))(0.67)(SO(3))(0.33).11H(2)O) formed. Significant volumes of gas were generated during curing and this produced a macro-porous microstructure that limited strength to 2.8 MPa. The new materials may have potential for use as controlled low-strength materials. PMID:18023169

  2. Stimulation of methane oxidation potential and effects on vegetation growth by bottom ash addition in a landfill final evapotranspiration cover.

    Science.gov (United States)

    Kim, Gil Won; Ho, Adrian; Kim, Pil Joo; Kim, Sang Yoon

    2016-09-01

    The landfilling of municipal solid waste is a significant source of atmospheric methane (CH4), contributing up to 20% of total anthropogenic CH4 emissions. The evapotranspiration (ET) cover system, an alternative final cover system in waste landfills, has been considered to be a promising way to mitigate CH4 emissions, as well as to prevent water infiltration using vegetation on landfill cover soils. In our previous studies, bottom ash from coal-fired power plants was selected among several industrial residues (blast furnace slag, bottom ash, construction waste, steel manufacture slag, stone powder sludge, and waste gypsum) as the best additive for ET cover systems, with the highest mechanical performance achieved for a 35% (wtwt(-1)) bottom ash content in soil. In this study, to evaluate the field applicability of bottom ash mixed soil as ET cover, four sets of lysimeters (height 1.2m×width 2m×length 6m) were constructed in 2007, and four different treatments were installed: (i) soil+bottom ash (35% wtwt(-1)) (SB); (ii) soil+compost (2% wtwt(-1), approximately corresponding to 40Mgha(-1) in arable field scale) (SC); (iii) soil+bottom ash+compost (SBC); and (iv) soil only as the control (S). The effects of bottom ash mixing in ET cover soil on CH4 oxidation potential and vegetation growth were evaluated in a pilot ET cover system in the 5th year after installation by pilot experiments using the treatments. Our results showed that soil properties were significantly improved by bottom ash mixing, resulting in higher plant growth. Bottom ash addition significantly increased the CH4 oxidation potential of the ET cover soil, mainly due to improved organic matter and available copper concentration, enhancing methanotrophic abundances in soil amended with bottom ash. Conclusively, bottom ash could be a good alternative as a soil additive in the ET cover system to improve vegetation growth and mitigate CH4 emission impact in the waste landfill system. PMID:27067424

  3. Preparation of Active Absorbent for Flue Gas Desulfurization From Coal Bottom Ash: Effect of Absorbent Preparation Variables

    OpenAIRE

    Chang Chin Li, Lee Keat Teong, Subhash Bhatia and Abdul Rahman Mohamed

    2012-01-01

    An active absorbent for flue gas desulfurization was prepared from coal bottom ash, calcium oxide (CaO) and calcium sulfate by hydro-thermal process. The absorbent was examined for its micro-structural properties. The experiments conducted were based on Design Of Experiments (DOE) according to 23 factorial design. The effect of various absorbent preparation variables such as ratio of CaO to bottom ash (A), hydration temperature (B) and hydration period (C) towards the BET (Brunauer-Emmett-Tel...

  4. COMPARATIVE STUDY OF HEAVY METALS IN BOTTOM ASH FROM INCINERATORS AND OPEN PIT FROM HEALTHCARE FACILITIES IN GHANA

    OpenAIRE

    Richard Amfo-Otua; Sarah Graham Kyerewaa; Emmanuel Adu Ofori; Adams Sadick

    2015-01-01

    Treatment of healthcare waste either by incinerating or open burning in a pit produces bottom ashes which contains heavy metals and other chemicals which are toxic, persistent and accumulate in the food chain resulting in adverse health effects in human and the environment. The study investigated the level of heavy metals in the ashes of thermally treated medical waste from four health care facilities in Ghana. Two batch of the ash samples were collected from two hospital incinerators and the...

  5. Charm and bottom hadronic form factors with QCD sum rules

    International Nuclear Information System (INIS)

    We present a brief review of some calculations of form factors and coupling constants in vertices with charm and bottom mesons in the framework of QCD sum rules. We first discuss the motivation for this work, describing possible applications of these form factors to charm and bottom decays processes. We first make a summarize of the QCD sum rules method. We give special attention to the uncertainties of the method introducing by the intrinsic variation of the parameters. Finally we conclude.

  6. Characterization of controlled low-strength material obtained from dewatered sludge and refuse incineration bottom ash: mechanical and microstructural perspectives.

    Science.gov (United States)

    Zhen, Guangyin; Lu, Xueqin; Zhao, Youcai; Niu, Jing; Chai, Xiaoli; Su, Lianghu; Li, Yu-You; Liu, Yuan; Du, Jingru; Hojo, Toshimasa; Hu, Yong

    2013-11-15

    Potential reuse of dewatered sludge (DS) and municipal solid waste incineration (MSWI) bottom ash as components to develop controlled low-strength material (CLSM) was explored. The effects of DS:MSWI bottom ash:calcium sulfoaluminate (CS¯A) cement ratio and thermal treatment of MSWI bottom ash at 900 °C on the mechanical and microstructural properties of CLSM were intensively studied to optimize the process. Results showed DS and MSWI bottom ash could be utilized for making CLSM. The CLSM prepared with milled MSWI bottom ash gave higher unconfined compressive strength (UCS) of 2.0-6.2 MPa following 1 year of curing at 1.0:0.1:0.9 ≤ DS:MSWI bottom ash:CS¯A ≤ 1.0:0.8:0.2. However, the corresponding strengths for CLSM containing thermally treated MSWI bottom ash ranged from 0.7 to 4.6 MPa, decreasing 26-65%. The microstructural analysis by X-ray powder diffraction (XRD), Fourier transforms infrared spectroscopy (FT-IR), as well as scanning electron microscopy (SEM) combined with an energy dispersive X-ray spectroscopy (EDS) revealed that ettringite (C3A·3CS¯·H32, or AFt) crystals were the most important strength-producing constituents which grew into and filled the CLSM matrix pores. Milled MSWI bottom ash addition favored the formation of highly crystalline AFt phases and accordingly enhanced compressive strengths of CLSM specimens. In contrast, thermal treatment at 900 °C produced new phases such as gehlenite (Ca2Al2SiO7) and hydroxylapatite (Ca5(PO4)3(OH)), which deteriorated the pozzolanic activity of bottom ash and caused the strengths to decrease. Leaching tests evidenced that leachable substances from CLSM samples exhibited negligible health and environmental risks. The results of this study suggested that MSWI bottom ash can be effectively recycled together with DS in developing CLSM mixtures with restricted use of CS¯A cement. PMID:23933484

  7. Properties of geopolymer from circulating fluidized bed combustion coal bottom ash

    International Nuclear Information System (INIS)

    Research highlights: → Dry cured geopolymers exhibit a heterogeneous and porous gel matrix. → The Si/Na atomic ratio of the main reaction product (N-A-S-H gel) is close to 1. → Low Si/Na ratio (0.5) correspond to a more crystalline stage of the N-A-S-H gel. → N-A-S-H gel has small pores which facilitate the escape of moisture when it is heated. → N-A-S-H gel became more amorphous, attaining higher Si/Al ratio of 4.54 at 800 deg. C. - Abstract: Compressive strength, atomic ratios and microstructure of geopolymer mortars (GM) made from circulating fluidized bed combustion (CFBC) coal bottom ash (CBA) were investigated to observe the effect of air curing at ambient temperature (AC) at 20 deg. C and 90% RH, dry curing (DC) at 80 deg. C and 40% RH for 20 h. The 28-d compressive strength of GM exposed to AC (GM-AC) and DC (GM-DC) were 26.23 and 24.14 MPa, respectively. The Si/Na atomic ratio of the main reaction product (N-A-S-H gel) was close to 1. Geopolymer gel (apparently crystalline) having low Si/Na ratio (0.5) may correspond to a more advanced or developed stage of the aluminosilicate gel. It was observed that the geopolymerization was completed before the N-A-S-H gel formed when Si/Na ratio of GM is close to 2. The color of the GM changed from pink to grey and the structure became denser with almost no pores, when the temperature increased from 400 to 800 deg. C. The N-A-S-H gel became more amorphous due to the sintering reactions attaining Si/Al and Si/Na ratios of 4.54 and 0.98, respectively.

  8. Heavy duty gas turbines experience with ash-forming fuels

    OpenAIRE

    Molière, M.; Sire, J

    1993-01-01

    The heavy duty gas turbines operating in power plants can burn various fuels ranging from natural gas to heavy oils. Ash-forming fuels can have detrimental effects on the turbine hardware such as : combustion troubles, erosion, corrosion and fouling by ashes. For decades, progress has been made by the gas turbine industry, especially in the fields of superalloy metallurgy, coating and cooling technology. Furthermore, fuel treatments inspired by the petroleum and marine-engine industries (elec...

  9. Feasibility of manufacturing geopolymer bricks using circulating fluidized bed combustion bottom ash.

    Science.gov (United States)

    Chen, Chen; Li, Qin; Shen, Lifeng; Zhai, Jianping

    2012-06-01

    This paper presents a study on geopolymer bricks manufactured using bottom ash from circulating fluidized bed combustion (CFBC). The alkali activators used for synthesis were sodium silicate, sodium hydroxide, and potassium hydroxide and lithium hydroxide solutions. The study included the impact of alkali activator on compressive strength. The reaction products were analysed by XRD, FT-IR and SEM/EDS. The compressive strength of bricks was dependent on the modulus of the sodium silicate activator and the type and concentration of alkali activator. The highest compressive strength could be gained when the modulus was 1.5, and the value could reach 16.1 MPa (7 d after manufacture) and 21.9 MPa (28 d after manufacture). Under pure alkaline systems, the compressive strength was in the order of 10 M KOH > 10 M NaOH > 5 M LiOH > 5 M KOH > 5 M NaOH. Quartz was the only crystalline phase in the original bottom ash, and no new crystalline phase was found after the reaction. The main product of reaction was amorphous alkali aluminosilicate gel and a small amount of crystalline phase was also found by SEM. PMID:22856304

  10. Use of co-combustion bottom ash to design an acoustic absorbing material for highway noise barriers

    Energy Technology Data Exchange (ETDEWEB)

    Arenas, Celia; Leiva, Carlos; Vilches, Luis F. [University of Seville, School of Industrial Engineering, Department of Chemical and Environmental Engineering, Camino de los Descubrimientos s/n, E-41092 Seville (Spain); Cifuentes, Héctor, E-mail: bulte@us.es [University of Seville, School of Industrial Engineering, Continuum Mechanics and Structural Analysis Department, Camino de los Descubrimientos s/n, E-41092 Seville (Spain)

    2013-11-15

    Highlights: • The particle size of bottom ash influenced the acoustic behavior of the barrier. • The best sound absorption coefficients were measured for larger particle sizes. • The maximum noise absorption is displaced to lower frequencies for higher thickness. • A noise barrier was designed with better properties than commercial products. • Recycling products from bottom ash no present leaching and radioactivity problems. - Abstract: The present study aims to determine and evaluate the applicability of a new product consisting of coal bottom ash mixed with Portland cement in the application of highway noise barriers. In order to effectively recycle the bottom ash, the influence of the grain particle size of bottom ash, the thickness of the panel and the combination of different layers with various particle sizes have been studied, as well as some environmental properties including leachability (EN-12457-4, NEN-7345) and radioactivity tests. Based on the obtained results, the acoustic properties of the final composite material were similar or even better than those found in porous concrete used for the same application. According to this study, the material produced presented no environmental risk.

  11. 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

  12. Removal of vertigo blue dyes from Batik textile wastewater by adsorption onto activated carbon and coal bottom ash

    Science.gov (United States)

    Kusmiyati, L., Puspita Adi; Deni, V.; Robi Indra, S.; Islamica, Dlia; Fuadi, M.

    2016-04-01

    Removal of vertigo blue dye from batik textile wastewater was studied by adsorptionprocess onto activated carbon (AC) and coal bottom ash (CBA).The influence of experimental conditions (pH solution, dye concentration, and contact time) were studied on the both adsorbents. At equilibrium conditions, the data were fitted to Langmuir and Freundlich adsorption models. The maximum adsorption capacity calculated from the Langmuir model for carbon active was 6.29mg/g at pH that found to be considerably higher than that obtained for coal bottom ash 3.72mg/g pH 9. From Freundlich model, the maximum adsorption capacity is less for coal bottom ash (pH 9) than that for carbon active (pH4).

  13. Leaching of Copper from MSWI Bottom Ash, Practical Measures for Improvement and Conditions for Utilization of the Ash as Civil Construction Material

    Czech Academy of Sciences Publication Activity Database

    Svoboda, Karel; Pohořelý, Michael; Baxter, D.; Vošta, J.

    Vol. Section IV. Sofia, 2004 - (Batov, S.), s. 265-271 [ Energy Forum 2004. Varna (BG), 11.06.2004-13.06.2004] Institutional research plan: CEZ:AV0Z4072921 Keywords : bottom ash * measures * utilization Subject RIV: DJ - Water Pollution ; Quality

  14. Application of paste technology to mitigate the dust emissions from handling of fly and bottom ash at coal fired power plant : CGTEE in Candiota, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Silva Marques, M.E. [Golder Associates Peru, Lima (Peru); Lima, H. [Golder Associates Brazil, Sao Paulo (Brazil); Mandl, B.; Francoeur, R.; Palkovits, F. [Golder Paste Technology Ltd., Mississauga, ON (Canada); Blois, R. [Companhia de Geracao Termica de Energia Electrica, Porto Alegre (Brazil)

    2010-07-01

    This paper discussed a method developed to reduce dust emissions generated in a fly ash handling procedure used at a thermal power plant located in the south of Brazil. The fly ash is collected in dry form at several locations in the plant and pneumatically conveyed to storage silos, where it is moistened with water in a mixer, loaded into dump trucks and deposited in a disposal area near a surface coal mine. The new solution created low density fly ash slurry in localized mixing tanks within the power plant. The low density slurry is pumped to an ash conditioning plant where the slurry is then mixed with the bottom ash, dewatered, and densified. The densified slurry is then pumped to an adjacent coal mine disposal site in order to be used as backfill in mined areas. The proposed method will significantly reduce dust emissions both inside and outside the plant, and will substantially reduce truck traffic at the mine. The method will reduce the environmental impacts associated with fly ash dust emissions in the region. 8 figs.

  15. The use of the bottom ashes and of the steelmaking slags in the manufacturing technologies of the building materials

    Directory of Open Access Journals (Sweden)

    L. G. Popescu

    2016-07-01

    Full Text Available The energetic and metallurgy industries of Romania represent the main waste sources significant from the point of quantitative view: the bottom ashes and the blast furnace and secondary metallurgical slags. Starting from the knowledge of the main chemical-physical properties of these two types of industrial wastes, there were inquired the exploitation possibilities in the technological practice, by using in the manufacturing of some building materials, for which these wastes represent the exclusive raw material source. The experiments considered the granular aggregate properties of the bottom ash and of the blast furnace slag, completed by the hydraulic binder of the secondary metallurgical slag, after the fine crushing.

  16. Potential usage of fly and bottom ash from thermal power plant ”Nikola Tesla” landfill, Serbia

    OpenAIRE

    Čudić Vladica V.; Stojiljković Dragoslava D.; Jovović Aleksandar M.; Životić Miodrag M.

    2012-01-01

    In Serbia, the ash from power plants has long been labelled as hazardous waste. With the adoption of the appropriate legislation this ash became secondary raw material with the potential usage. In this paper an analysis of the fly and bottom ash composition, which are disposed of in the power plant “Nikola Tesla A” landfill, is presented. Thirty samples, divided into three sets, were analyzed for trace elements As, Ba, Be, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Ti, V and Zn. The first and seco...

  17. Hazard remediation and recycling of tea industry and paper mill bottom ash through vermiconversion.

    Science.gov (United States)

    Goswami, Linee; Patel, Arbind Kumar; Dutta, Ganesh; Bhattacharyya, Pradip; Gogoi, Nirmali; Bhattacharya, Satya Sundar

    2013-07-01

    Considerable amount of bottom ash (BA) is produced by tea and paper factories in Northeast India. This significantly deteriorates soil and surface water quality through rapid acidification, releasing sulfur compounds and heavy metals. The present investigation endeavoured to convert this waste to organic manure through vermicomposting by Eisenia fetida. Substantial increment in bioavailability of N, P, K, Fe, Mn and Zn along with remarkable decline in toxic metal like Cr due to vermicomposting was noteworthy. Furthermore, vermicomposted mixtures of Tea Factory BA (TFBA) or Paper Mill BA (PMBA) with organic matter (OM) attributed profuse pod yield of French Bean (Phaseolus vulgaris L.). Hence, bioconversion of TFBA and PMBA is highly feasible through vermicomposting and the converted materials can be utilized as potential organic fertilizer. PMID:23706375

  18. Comparison of activated carbon and bottom ash removal of reactive dye from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Dincer, A.R.; Gunes, Y.; Karakaya, N.; Gunes, E. [Trakya University, Tekirdag (Turkey). Dept. of Environmental Engineering

    2007-03-15

    The adsorption of reactive dye from synthetic aqueous solution onto granular activated carbon (GAC) and coal-based bottom ash (CBBA) were studied under the same experimental conditions. As an alternative to GAC CBBA was used as adsorbent for dye removal from aqueous solution. The amount of Vertigo Navy Marine (VNM) adsorbed onto CBBA was lower compared with GAC at equilibrium and dye adsorption capacity increased from 0.71 to 3.82 mg g{sup -1}, and 0.73 to 6.35 mg g{sup -1} with the initial concentration of dye from 25 to 300 mg l{sup -1} respectively. The initial dye uptake of CBBA was not so rapid as in the case of GAC and the dye uptake was slow and gradually attained equilibrium.

  19. Bioaccumulations of heavy metals in Ipomoea aquatica grown in bottom ash recycling wastewater.

    Science.gov (United States)

    Milla, Odette Varela; Rivera, Eva B; Huang, Wu-Jang

    2014-05-01

    A plant bioassay using hydroponically grown Ipomoea aquatica (water spinach) was applied to assess the phytotoxicity of untreated and treated wastewaters from a municipal solid waste incineration bottom ash recycling facility. The 50%-diluted, untreated wastewater exhibited acute toxicity (plants died within 24 hours). Highly diluted doses (3 and 6%) of both wastewater types displayed no significant differences when compared with the control. Treating the wastewater through sequential physical filtration and chemical precipitation processes decreased not only the dissolved solids content but also the pH and salt content. In addition, significant accumulations of Sr, Cr, and Sn were observed in the hydroponically grown I. aquatica plant tissues; in particular, the bioaccumulation of Sr in the leaves and roots was unexpectedly high. PMID:24961066

  20. Use of bottom ash from thermal power plant and lime as filler in bituminous mixtures

    Directory of Open Access Journals (Sweden)

    López-López, E.

    2015-06-01

    Full Text Available This study focuses on the characterization of bottom ash (PCC-BA and determining the mechanical characteristics of hot mix asphalt (HMA using PCC-BA and hydrated lime (HL as filler. Physical and chemical characterization of the bottom ash was carried out to evaluate its eventual reutilization as filler substitute. The materials tested in this study were made using 0%, 25%, 50%, 70% and 100% of PCC-BA combined with HL. HMA mixes were evaluated in terms of their engineering properties, namely: air voids in the mixes, water sensitivity, stiffness modulus, performance in wheel tracking test and fatigue resistance. The results obtained indicate that HMA mixes with a filler blend of 70% PCC-BA and 30% HL fulfil European standards and are suitable for light traffic or small infrastructures.Este estudio se centra en la caracterización de las cenizas de fondo (PCC-BA y la determinación de las características mecánicas de mezclas bituminosas en caliente (HMA, utilizando cenizas de fondo y la cal hidratada (HL como filler. Se realizó la caracterización física y química de las cenizas de fondo para evaluar su empleo como sustituto de filler. Las mezclas ensayadas en este estudio se realizaron utilizando 0%, 25%, 50%, 70% y 100% de cenizas de fondo combinadas con cal hidratada. Se evaluaron propiedades ingenieriles de las mezclas bituminosas, tales como los huecos de aire en las mezclas, la sensibilidad al agua, el módulo de rigidez, el ensayo de pista y la resistencia a la fatiga. Los resultados obtenidos indican que las mezclas bituminosas fabricadas con una combinación de filler del 70% de cenizas de fondo y el 30% cal hidratada, cumplen con las normas europeas y son adecuados para su aplicación con tráficos ligeros o en pequeñas infraestructuras.

  1. An important form of uranium occurrence in refractory uraniferous ash

    International Nuclear Information System (INIS)

    Four kinds of nondesturctive experimental means, liquid nuclear emuesion microradiography, electron-probe analysis of microrange composition, and X-ray diffraction analysis with Debye camera for single particle and scanning electron-microscopy, are combined into a systematic experimental method for researching small particles of uranium ore. And it is called YDDS method according to the first letters of the Chinese phonetic alphabet of each means' name. The research results about the ash obtained from the first uraniferous lignite processing plant in China using the YDDS method are described. The important form of uranium occurrence in the refractory ash is determined

  2. Vitrified bottom ash slag from municipal solid waste incinerators - Phase relations of CaO-SiO2-Na20 oxide system

    NARCIS (Netherlands)

    Zhang, Z.; Xiao, Y.; Yang, Y.; Boom, R.; Voncken, J.H.L.

    2009-01-01

    Vitrification is considered to be an attractive technology for bottom ash treatment because it destroys the hazardous organics, contributes to immobilization of the heavy metals, and additionally it reduces drastically the volume. The main components of the vitrified bottom ash slag are SiO2 , CaO,

  3. Experimental investigation of the Rowe's dilatancy law on an atypical granular medium from a municipal solid waste incineration bottom ash

    Science.gov (United States)

    Becquart, Frédéric; Abriak, Nor Edine

    2013-06-01

    Municipal Solid Waste Incineration (MSWI) bottom ashes are irregular granular media because of their origin and are very heterogeneous with a large quantity of angular particles of different chemical species. MSWI bottom ash is a renewable granular resource alternative to the use of non-renewable standard granular materials. Beneficial use of these alternative granular materials mainly lies in road engineering. However, the studies about mechanical properties of such granular media still remain little developed, those being mainly based on empirical considerations. In this paper, a study of mechanical behaviour of a MSWI bottom ash under axisymmetric triaxial loadings conditions is presented. Samples are initially dense after Proctor compaction, are saturated and tested in drained conditions, under different effective confining pressures ranging from 100 to 600 kPa. The evolutions of volumetric strains show an initial contracting phase followed by a dilatancy phase, more pronounced when the confining pressure is low. The stresses ratios at the characteristic state and at the critical state appear in good agreement and with a null rate of volume variation. The angles of internal friction and dilatancy of the studied MSWI bottom ash are estimated and are similar to conventional granular materials used especially in road engineering. The dilatancy law of Rowe is well experimentally verified on this irregular recycled granular material.

  4. Use of bottom ash from olive pomace combustion in the production of eco-friendly fired clay bricks.

    Science.gov (United States)

    Eliche-Quesada, D; Leite-Costa, J

    2016-02-01

    Olive pomace bottom ash was used to replace different amounts (10-50wt%) of clay in brick manufacturing. The aim of this study is both studying bricks properties and showing a new way of olive pomace bottom ash recycling. Properties of waste bricks were compared to conventional products following standard procedures in order to determine the maximum waste percentage. The amount of olive pomace bottom ash is limited to 20wt%, obtaining bricks with superior engineering properties when 10wt% of waste is added. Adding higher amount of waste (30-50wt%) resulted in bricks with water absorption and compressive strength values on the edge of meeting those established by standards. Therefore, the addition of 10 and 20wt% of olive pomace bottom ash produced bricks with a bulk density of 1635 and 1527kg/m(3) and a compressive strength of 33.9MPa and 14.2MPa, respectively. Fired bricks fulfil standards requirements for clay masonry units, offering, at the same time, better thermal insulation of buildings due to a reduction in thermal conductivity of 14.4% and 16.8% respectively, compared to control bricks (only clay). PMID:26653359

  5. Mechanisms contributing to the thermal analysis of waste incineration bottom ash and quantification of idfferent carbon species

    NARCIS (Netherlands)

    Rocca, S.; Zomeren, van A.; Costa, G.; Dijkstra, J.J.; Comans, R.N.J.; Lombardi, F.

    2013-01-01

    The focus of this study was to identify the main compounds affecting the weight changes of bottom ash (BA) in conventional loss on ignition (LOI) tests and to obtain a better understanding of the individual processes in heterogeneous (waste) materials such as BA. Evaluations were performed on BA sam

  6. The leaching of trace elements from municipal solid waste incinerator bottom ash at different stages of weathering

    NARCIS (Netherlands)

    Meima, J.A.; Comans, R.N.J.

    1999-01-01

    For a proper assessment of the environmental impact of the utilisation and disposal of Municipal Solid Waste Incinerator (MSWI) bottom ash it is necessary to understand weathering processes and their effects on (trace) element leaching. The authors have investigated the processes that control the le

  7. Full Scale Tests of Short-Term Municipal Solid Waste Incineration Bottom Ash Weathering Before Landfill Disposal

    Directory of Open Access Journals (Sweden)

    Franco Marchese

    2009-01-01

    Full Text Available Problem statement: Natural weathering is the most economic method of treatment in order to reduce the release of heavy metals present in the residue. Approach: The aim of the study was to optimize the minimum weathering times that were useful to reduce the lead release to within the Italian limits for landfill disposal. The mechanism of short-term weathering of MSWI bottom ash had been studied and its effect on the leaching of lead had been evaluated. Two bottom ash heaps had been realized for the experimental assessment: In one case an open-air situation was used, in the other, a heap placed under shelter was not exposed to rain. Results: The weathering course was monitored through the results of a leaching test that was carried out at different ageing times (EN 12457-2:2002. The total carbonates were also measured, at the same time, on the fine fraction of the weathered bottom ash (2 was fixed by air. The pH value was controlled by Portlandite dissolution only at the beginning, after the pH control seems to be due to aluminum hydroxides. Conclusion: The most significant changes in the bottom ash were found to occur in the first 60 days. It had been possible to verify the limited influence of washing phenomena while it was confirmed that carbonation was the most important process in short-term weathering and that it had an important rule on limiting lead release.

  8. Influence of Bottom Ash Replacements as Fine Aggregate on the Property of Cellular Concrete with Various Foam Contents

    Directory of Open Access Journals (Sweden)

    Patchara Onprom

    2015-01-01

    Full Text Available This research focuses on evaluating the feasibility of utilizing bottom ash from coal burning power plants as a fine aggregate in cellular concrete with various foam contents. Flows of all mixtures were controlled within 45 ± 5% and used foam content at 30%, 40%, 50%, 60%, and 70% by volume of mixture. Bottom ash from Mae Moh power plant in Thailand was used to replace river sand at the rates of 0%, 25%, 50%, 75%, and 100% by volume of sand. Compressive strength, water absorption, and density of cellular concretes were determined at the ages of 7, 14, and 28 days. Nonlinear regression technique was developed to construct the mathematical models for predicting the compressive strength, water absorption, and density of cellular concrete. The results revealed that the density of cellular concrete decreased while the water absorption increased with an increase in replacement level of bottom ash. From the experimental results, it can be concluded that bottom ash can be used as fine aggregate in the cellular concrete. In addition, the nonlinear regression models give very high degree of accuracy (R2>0.99.

  9. Preparation of Active Absorbent for Flue Gas Desulfurization From Coal Bottom Ash: Effect of Absorbent Preparation Variables

    Directory of Open Access Journals (Sweden)

    Chang Chin Li, Lee Keat Teong, Subhash Bhatia and Abdul Rahman Mohamed

    2012-08-01

    Full Text Available An active absorbent for flue gas desulfurization was prepared from coal bottom ash, calcium oxide (CaO and calcium sulfate by hydro-thermal process. The absorbent was examined for its micro-structural properties. The experiments conducted were based on Design Of Experiments (DOE according to 23 factorial design. The effect of various absorbent preparation variables such as ratio of CaO to bottom ash (A, hydration temperature (B and hydration period (C towards the BET (Brunauer-Emmett-Teller specific surface area of the absorbent were studied. At a CaO to bottom ash ratio = 2, hydration temperature = 200 ?C and hydration period = 10 hrs, absorbent with a surface area of 90.1 m2/g was obtained. Based on the analysis of the factorial design, it was concluded that factor A and C as well as the interaction of factors ABC and BC are the significant factors that effect the BET surface area of the absorbent. A linear mathematical model that describes the relation between the independent variables and interaction between variables towards the BET specific surface area of the absorbent was also developed. Analysis of variance (ANOVA showed that the model was significant at 1% level.Key Words: Absorbent, Bottom Ash, Design Of Experiments, Desulfurization, Surface Area.

  10. Mineralogy and chemical composition of technogenic soils (Technosols developed from fly ash and bottom ash from selected thermal power stations in Poland

    Directory of Open Access Journals (Sweden)

    Uzarowicz Łukasz

    2015-06-01

    Full Text Available The aim of the study was to determine the mineral and chemical composition of technogenic soils (Technosols developed from fly ash and bottom ash from power plants in which bituminous coal and lignite was combusted. The mineral composition of the “fresh” wastes (i.e. fly ash and bottom ash and soil samples derived from them was examined by X-ray diffraction (XRD and using a scanning electron microscope (SEM. The chemical composition (content of major elements was determined using ICP-AES method. Quartz, mullite, and amorphous substances (glass predominated in the mineral composition of wastes after bituminous coal combustion. Magnetite was also found there. Soils developed from wastes after bituminous coal combustion contained all above mentioned minerals inherited from fly ash and bottom ash. Moreover, small amounts of secondary calcite were identified. In some soil horizons containing large amounts of inherited magnetite, secondary iron oxides and oxyhydroxides (goethite and lepidocrocite also occurred. Quartz predominated in the mineral composition of the “fresh” wastes after lignite combustion. Relatively small amounts of iron oxides (magnetite and hematite were also found there. In “fresh” fly ash, apart from minerals mentioned above, anhydrite and calcium oxide (lime was identified. Soils developed from wastes after lignite combustion contained inherited quartz, magnetite, and hematite. Furthermore, calcite which sometimes was a predominating mineral in certain soil horizons occurred. Moreover, sulphates (gypsum, bassanite, and ettringite, and vaterite (a polymorph of Ca carbonate were also found in soils. Silicon predominated among major elements in “fresh” ashes after bituminous coal combustion and soil derived from them followed by Al, Fe, K, Ca, Mg, Ti, Na, P, and Mn. On the other hand, the contents of major elements in the samples (ashes and soils after lignite combustion can be arranged as follows: Si, Ca, Fe, Al, Mg

  11. Content and the forms of heavy metals in bottom sediments in the zone of industrial pollution sources ,

    OpenAIRE

    Voytyuk Y.Y.; Kurayeva I.V.; Kroyik H.A.; Karmazynenko S.P.; Matsibora O.V.

    2014-01-01

    Regularities in the distribution of heavy metals in sediments in the zone of influence of the steel industry in Mariupol are installed. The study results of the forms of occurrence of Zn, Pb, Cu, Cr, Ni are represented. Ecological and geochemical assessment of sediment contamination by heavy metals is performed. The main sources of pollution of bottom sediments are air borne emissions from industrial plants, hydrogenous pollution in industrial sewage entering the water, sewage sludge, ash dum...

  12. M(o)ssbauer spectroscopic studies the characterization of three China coal and the corresponding fly-ashes and bottom ashes

    Institute of Scientific and Technical Information of China (English)

    YAO Duo-xi; ZHI Xia-chen

    2006-01-01

    Three fresh China coals (lignitie, bituminite and anthracite) from different geological origin and the corresponding fly and bottom ashes were studied by room temperature(RT) M(o)ssbauer spectroscopy(MS). The iron-bearing minerals were characterized to was found in bituminite and anthracite coal.The M(o)ssbauer spectra of the fly and bottom ashes as a result of pulverised coal combustion(PCC) in Xiaolongtan,Shuicheng and Luohuang Power Plants are comprised of superimposed sextets and doulets of oxides includes maghemite(γ-Fe2O3), magnitite(Fe3O4), haematite(α-Fe2O3), magnesioferite (MgFe2O4), Fe3+/Fe2+-mullite, Fe3+-glass silicate andmetallic iron. The studies also show that iron-bearing minerals in coals are largely dependant on geological regions and coal rank, the composition of the corresponding fly and bottom ashes will not only depend on the type and mineralogy of the feed coal but also on the local nature of combustion.

  13. Development of a sintering process for recycling oil shale fly ash and municipal solid waste incineration bottom ash into glass ceramic composite

    International Nuclear Information System (INIS)

    Highlights: • Glass ceramic composite is prepared from oil shale fly ash and MSWI bottom ash. • A novel method for the production of glass ceramic composite is presented. • It provides simple route and lower energy consumption in terms of recycling waste. • The vitrified slag can promote the sintering densification process of glass ceramic. • The performances of products decrease with the increase of oil shale fly ash content. - Abstract: Oil shale fly ash and municipal solid waste incineration bottom ash are industrial and municipal by-products that require further treatment before disposal to avoid polluting the environment. In the study, they were mixed and vitrified into the slag by the melt-quench process. The obtained vitrified slag was then mixed with various percentages of oil shale fly ash and converted into glass ceramic composites by the subsequent sintering process. Differential thermal analysis was used to study the thermal characteristics and determine the sintering temperatures. X-ray diffraction analysis was used to analyze the crystalline phase compositions. Sintering shrinkage, weight loss on ignition, density and compressive strength were tested to determine the optimum preparation condition and study the co-sintering mechanism of vitrified amorphous slag and oil shale fly ash. The results showed the product performances increased with the increase of sintering temperatures and the proportion of vitrified slag to oil shale fly ash. Glass ceramic composite (vitrified slag content of 80%, oil shale fly ash content of 20%, sintering temperature of 1000 °C and sintering time of 2 h) showed the properties of density of 1.92 ± 0.05 g/cm3, weight loss on ignition of 6.14 ± 0.18%, sintering shrinkage of 22.06 ± 0.6% and compressive strength of 67 ± 14 MPa. The results indicated that it was a comparable waste-based material compared to previous researches. In particular, the energy consumption in the production process was reduced compared

  14. Arsenic remediation of drinking water using iron-oxide coated coal bottom ash

    Energy Technology Data Exchange (ETDEWEB)

    MATHIEU, JOHANNA L.; GADGIL, ASHOK J.; ADDY, SUSAN E.A.; KOWOLIK, KRISTIN

    2010-06-01

    We describe laboratory and field results of a novel arsenic removal adsorbent called 'Arsenic Removal Using Bottom Ash' (ARUBA). ARUBA is prepared by coating particles of coal bottom ash, a waste material from coal fired power plants, with iron (hydr)oxide. The coating process is simple and conducted at room temperature and atmospheric pressure. Material costs for ARUBA are estimated to be low (~;;$0.08 per kg) and arsenic remediation with ARUBA has the potential to be affordable to resource-constrained communities. ARUBA is used for removing arsenic via a dispersal-and-removal process, and we envision that ARUBA would be used in community-scale water treatment centers. We show that ARUBA is able to reduce arsenic concentrations in contaminated Bangladesh groundwater to below the Bangladesh standard of 50 ppb. Using the Langmuir isotherm (R2 = 0.77) ARUBA's adsorption capacity in treating real groundwater is 2.6x10-6 mol/g (0.20 mg/g). Time-to-90percent (defined as the time interval for ARUBA to remove 90percent of the total amount of arsenic that is removed at equilibrium) is less than one hour. Reaction rates (pseudo-second-order kinetic model, R2>_ 0.99) increase from 2.4x105 to 7.2x105 g mol-1 min-1 as the groundwater arsenic concentration decreases from 560 to 170 ppb. We show that ARUBA's arsenic adsorption density (AAD), defined as the milligrams of arsenic removed at equilibrium per gram of ARUBA added, is linearly dependent on the initial arsenic concentration of the groundwater sample, for initial arsenic concentrations of up to 1600 ppb and an ARUBA dose of 4.0 g/L. This makes it easy to determine the amount of ARUBA required to treat a groundwater source when its arsenic concentration is known and less than 1600 ppb. Storing contaminated groundwater for two to three days before treatment is seen to significantly increase ARUBA's AAD. ARUBA can be separated from treated water by coagulation and clarification, which is expected to

  15. Residual organic matter and microbial respiration in bottom ash: Effects on metal leaching and eco-toxicity.

    Science.gov (United States)

    Ilyas, A; Persson, K M; Persson, M

    2015-09-01

    A common assumption regarding the residual organic matter, in bottom ash, is that it does not represent a significant pool of organic carbon and, beyond metal-ion complexation process, it is of little consequence to evolution of ash/leachate chemistry. This article evaluates the effect of residual organic matter and associated microbial respiratory processes on leaching of toxic metals (i.e. arsenic, copper, chromium, molybdenum, nickel, lead, antimony and zinc), eco-toxicity of ash leachates. Microbial respiration was quantified with help of a respirometric test equipment OXITOP control system. The effect of microbial respiration on metal/residual organic matter leaching and eco-toxicity was quantified with the help of batch leaching tests and an eco-toxicity assay - Daphnia magna. In general, the microbial respiration process decreased the leachate pH and eco-toxicity, indicating modification of bioavailability of metal species. Furthermore, the leaching of critical metals, such as copper and chromium, decreased after the respiration in both ash types (fresh and weathered). It was concluded that microbial respiration, if harnessed properly, could enhance the stability of fresh bottom ash and may promote its reuse. PMID:25999368

  16. Leaching behaviour of bottom ash from RDF high-temperature gasification plants

    International Nuclear Information System (INIS)

    This study investigated the physical properties, the chemical composition and the leaching behaviour of two bottom ash (BA) samples from two different refuse derived fuel high-temperature gasification plants, as a function of particle size. The X-ray diffraction patterns showed that the materials contained large amounts of glass. This aspect was also confirmed by the results of availability and ANC leaching tests. Chemical composition indicated that Fe, Mn, Cu and Cr were the most abundant metals, with a slight enrichment in the finest fractions. Suitability of samples for inert waste landfilling and reuse was evaluated through the leaching test EN 12457-2. In one sample the concentration of all metals was below the limit set by law, while limits were exceeded for Cu, Cr and Ni in the other sample, where the finest fraction showed to give the main contribution to leaching of Cu and Ni. Preliminary results of physical and geotechnical characterisation indicated the suitability of vitrified BA for reuse in the field of civil engineering. The possible application of a size separation pre-treatment in order to improve the chemical characteristics of the materials was also discussed.

  17. Review on Current Research Status on Bottom Ash: An Indian Prospective

    Science.gov (United States)

    Mandal, A. K.; Sinha, O. P.

    2014-12-01

    India focuses on attention towards "greener and cleaner" environment surrounding us. For that, the engineers and scientists have joined hands together to accept the challenges for recycling wastes from industries. The generation of Bottom Ash (BA) from thermal power plants which are being increased day by day and facing disposal and environmental problems. In spite of that, it is being used as landfills which has no commercial value, but now needs to think on its utilization as useable supplementary materials. But from the literature survey, it was found that a little amount of research have been carried out on BA in the area based on its adsorption capability of dyes; pelletization efficiency of cold bonded aggregate; compressive strength, durability, water absorption characteristics and density variation in concrete and mortar; in order to ensure its usage as adsorption as well as construction material. The present paper deals with a critical review on BA as an adsorbent, light weight aggregate as well as partial replacement of fine aggregate in concrete. In addition, physical and chemical properties, transportation and disposal mechanism and environmental effects are also discussed.

  18. Leaching of valuable elements from thermal power plant bottom ash using a thermo-hydrometallurgical process.

    Science.gov (United States)

    Bojinova, Darinka; Teodosieva, Ralitsa

    2016-06-01

    The solid industrial wastes generated from thermal power plants (TPPs) can be considered as renewable secondary sources for recovery of valuable metals. This study presents the results from investigations that integrated a thermo-hydro-metallurgical method for treatment of bottom ash obtained from the Enel Maritsa East 3 TPP in Bulgaria. Leaching was performed with 20, 30 and 40 wt% sulphuric acid, respectively, in an autoclave at 100(o)C, 120(o)C and 140(o)C for 120, 240, 360 and 480 min, at a constant value of the liquid/solid ratio. After autoclaving, the samples (suspensions) were diluted with a constant value of water and stirring at 50(o)C for 60 min. On the basis of the experimental data the leaching efficiency (α) of the elements in the liquid phase after filtration was estimated. The leaching of aluminium increases significantly with increasing of the temperature, reaching the maximum value of 70 wt%. The highest leaching efficiency values for the other elements are as follows: Fe (86.4%), Ca (86.6%), Na (86.6%), Ni (83.3%) and Zn (83.3%). The maximum value of leaching for Mg, K, Mn, Cu and Cr is in the interval of 46-70%. PMID:26951342

  19. Impact of MSWI bottom ash codisposed with MSW on landfill stabilization with different operational modes.

    Science.gov (United States)

    Li, Wen-Bing; Yao, Jun; Malik, Zaffar; Zhou, Gen-Di; Dong, Ming; Shen, Dong-Sheng

    2014-01-01

    The aim of the study was to investigate the impact of municipal solid waste incinerator (MSWI) bottom ash (BA) codisposed with municipal solid waste (MSW) on landfill stabilization according to the leachate quality in terms of organic matter and nitrogen contents. Six simulated landfills, that is, three conventional and three recirculated, were employed with different ratios of MSWI BA to MSW. The results depicted that, after 275-day operation, the ratio of MSWI BA to fresh refuse of 1 : 10 (V : V) in the landfill was still not enough to provide sufficient acid-neutralizing capacity for a high organic matter composition of MSW over 45.5% (w/w), while the ratio of MSWI BA to fresh refuse of 1 : 5 (V : V) could act on it. Among the six experimental landfills, leachate quality only was improved in the landfill operated with the BA addition (the ratio of MSWI BA to fresh refuse of 1 : 5 (V : V)) and leachate recirculation. PMID:24779006

  20. Improved electrical efficiency and bottom ash quality on waste combustion plants. Appendix A4 to A6

    Energy Technology Data Exchange (ETDEWEB)

    Kloeft, H.; Jensen, Peter A.; Nesterov, I.; Hyks, J.; Astrup, T. (Technical Univ. of Denmark, Kgs. Lyngby (Denmark)); Mogensen, Erhardt (Babcock and Wilcox Voelund A/S, Glostrup (Denmark))

    2010-07-01

    Investigations making it possible to evaluate and further develop concepts to improve electrical efficiency in a waste combustion plant were performed. Furthermore, one objective of the study was to investigate the possibilities of improving waste bottom ash leaching properties by use of a rotary kiln treatment. The project work included construction of a bench-scale rotary kiln, performing ash rotary kiln treatment experiments, conducting gas suction probe measurements on a waste incineration plant and making some concept evaluations. The influence of the rotary kiln thermal treatment on the leaching of Ca, Al, Si, Mg, Ba, Sr, Cl, Cu, Pb, Zn, Cr, Mo, sulfate, DOC and carbonate was determined. As a result of these tests, the rotary kiln thermal treatment of bottom ashes can be recommended for reducing the leaching of Cu, Pb, Cl, Zn and DOC; however, an increased leaching of Cr and Mo should be expected. The combustion conditions above the grate of a waste incineration plant were investigated and the release and concentration of volatile ash species in the flue gas such as Cl, Na, K, Ca, Pb, Zn and S were measured. The conducted measurements show that flue gas from grate sections 3 and 4 can produce a sufficiently hot flue gas that contains only low concentrations of corrosive species, and therefore can be used to increase superheater temperatures. Implementation of the so-called flue gas split concept together with other steam circle modifications on a waste combustion plant, and using a reasonable increase in final steam temperature from 400 to 500 deg. C, have the potential to increase electrical efficiency from 24 to 30% (with respect to lower fuel heating value) in a waste combustion plant. The appendices deal with collection of slags for the rotary kiln experiments; overview of the thermal treatment experiments - phase 1; a journal paper with the title ''Quantification of leaching from waste incineration bottom ash treated in a rotary kiln

  1. Improved electrical efficiency and bottom ash quality on waste combustion plants. Appendix A1 to A3

    Energy Technology Data Exchange (ETDEWEB)

    Nesterov, I.; Jensen, Peter A.; Dam-Johansen, K.; Kloeft, H.; Boejer, M. (Technical Univ. of Denmark, Kgs. Lyngby (Denmark)); Mogensen, Erhardt (Babcock and Wilcox Voelund A/S, Esbjerg (Denmark))

    2010-07-01

    Investigations making it possible to evaluate and further develop concepts to improve electrical efficiency in a waste combustion plant were performed. Furthermore, one objective of the study was to investigate the possibilities of improving waste bottom ash leaching properties by use of a rotary kiln treatment. The project work included construction of a bench-scale rotary kiln, performing ash rotary kiln treatment experiments, conducting gas suction probe measurements on a waste incineration plant and making some concept evaluations. The influence of the rotary kiln thermal treatment on the leaching of Ca, Al, Si, Mg, Ba, Sr, Cl, Cu, Pb, Zn, Cr, Mo, sulfate, DOC and carbonate was determined. As a result of these tests, the rotary kiln thermal treatment of bottom ashes can be recommended for reducing the leaching of Cu, Pb, Cl, Zn and DOC; however, an increased leaching of Cr and Mo should be expected. The combustion conditions above the grate of a waste incineration plant were investigated and the release and concentration of volatile ash species in the flue gas such as Cl, Na, K, Ca, Pb, Zn and S were measured. The conducted measurements show that flue gas from grate sections 3 and 4 can produce a sufficiently hot flue gas that contains only low concentrations of corrosive species, and therefore can be used to increase superheater temperatures. Implementation of the so-called flue gas split concept together with other steam circle modifications on a waste combustion plant, and using a reasonable increase in final steam temperature from 400 to 500 deg. C, have the potential to increase electrical efficiency from 24 to 30% (with respect to lower fuel heating value) in a waste combustion plant. The appendices deal with incineration bottom ash leaching properties; design and construction of rotary kiln facility; manual to rotary kiln experiments. (Author)

  2. Improved electrical efficiency and bottom ash quality on waste combustion plants. Appendix A7 to A10

    Energy Technology Data Exchange (ETDEWEB)

    Hyks, J.; Astrup, T.; Jensen, Peter A.; Nesterov, I.; Boejer, M.; Frandsen, F.; Dam-Johansen, K.; Hedegaard Madsen, O.; Lundtorp, K. (Technical Univ. of Denmark, Kgs. Lyngby (Denmark)); Mogensen, Erhardt (Babcock and Wilcox Voelund A/S, Glostrup (Denmark))

    2010-07-01

    Investigations making it possible to evaluate and further develop concepts to improve electrical efficiency in a waste combustion plant were performed. Furthermore, one objective of the study was to investigate the possibilities of improving waste bottom ash leaching properties by use of a rotary kiln treatment. The project work included construction of a bench-scale rotary kiln, performing ash rotary kiln treatment experiments, conducting gas suction probe measurements on a waste incineration plant and making some concept evaluations. The influence of the rotary kiln thermal treatment on the leaching of Ca, Al, Si, Mg, Ba, Sr, Cl, Cu, Pb, Zn, Cr, Mo, sulfate, DOC and carbonate was determined. As a result of these tests, the rotary kiln thermal treatment of bottom ashes can be recommended for reducing the leaching of Cu, Pb, Cl, Zn and DOC; however, an increased leaching of Cr and Mo should be expected. The combustion conditions above the grate of a waste incineration plant were investigated and the release and concentration of volatile ash species in the flue gas such as Cl, Na, K, Ca, Pb, Zn and S were measured. The conducted measurements show that flue gas from grate sections 3 and 4 can produce a sufficiently hot flue gas that contains only low concentrations of corrosive species, and therefore can be used to increase superheater temperatures. Implementation of the so-called flue gas split concept together with other steam circle modifications on a waste combustion plant, and using a reasonable increase in final steam temperature from 400 to 500 deg. C, have the potential to increase electrical efficiency from 24 to 30% (with respect to lower fuel heating value) in a waste combustion plant. The appendices deal with the influence of kiln treatment on incineration bottom ash leaching; the influence of kiln treatment on corrosive species in deposits; operational strategy for rotary kiln; alkali/chloride release during refuse incineration on a grate. (Author)

  3. Mechanisms contributing to the thermal analysis of waste incineration bottom ash and quantification of different carbon species

    Energy Technology Data Exchange (ETDEWEB)

    Rocca, S.; Costa, G.; Lombardi, F. [University of Rome ' Tor Vergata' , Department of Civil Engineering and Computer Science Engineering, Via del Politecnico 1, 00133 Rome (Italy); Van Zomeren, A.; Dijkstra, J.J. [Energy research Centre of the Netherlands ECN, Department of Environmental Assessment, P.O. Box 1, 1755 ZG Petten (Netherlands); Comans, R.N.J. [Wageningen University, Department of Soil Quality, P.O. Box 47, 6700 AA Wageningen (Netherlands)

    2013-02-15

    The focus of this study was to identify the main compounds affecting the weight changes of bottom ash (BA) in conventional loss on ignition (LOI) tests and to obtain a better understanding of the individual processes in heterogeneous (waste) materials such as BA. Evaluations were performed on BA samples from a refuse derived fuel incineration (RDF-I) plant and a hospital waste incineration (HW-I) plant using thermogravimetric analysis and subsequent mass spectrometry (TG-MS) analysis of the gaseous thermal decomposition products. Results of TG-MS analysis on RDF-I BA indicated that the LOI measured at 550C was due to moisture evaporation and dehydration of Ca(OH)2 and hydrocalumite. Results for the HW-I BA showed that LOI at 550C was predominantly related to the elemental carbon (EC) content of the sample. Decomposition of CaCO3 around 700C was identified in both materials. In addition, we have identified reaction mechanisms that underestimate the EC and overestimate the CaCO3 contents of the HW-I BA during TG-MS analyses. These types of artefacts are expected to occur also when conventional LOI methods are adopted, in particular for materials that contain CaO/Ca(OH)2 in combination with EC and/or organic carbon, such as e.g. municipal solid waste incineration (MSWI) bottom and fly ashes. We suggest that the same mechanisms that we have found (i.e. in situ carbonation) can also occur during combustion of the waste in the incinerator (between 450 and 650C) demonstrating that the presence of carbonate in bottom ash is not necessarily indicative for weathering. These results may also give direction to further optimization of waste incineration technologies with regard to stimulating in situ carbonation during incineration and subsequent potential improvement of the leaching behavior of bottom ash.

  4. Ten-year chemical evolution of leachate and municipal solid waste incineration bottom ash used in a test road site.

    Science.gov (United States)

    Dabo, David; Badreddine, Rabia; De Windt, Laurent; Drouadaine, Ivan

    2009-12-30

    The use of municipal solid waste incineration (MSWI) bottom ash for road and car-park construction is an appropriate solution to reduce their disposal and the consumption of natural materials. In addition to leaching tests, the environmental impact assessment of such a waste recycling scenario critically needs for reliable long-term field data. This paper addresses a 10-year pilot site where MSWI bottom ashes have been used as road aggregates in Northern France (oceanic temperate climate). The paper focuses on the long-term evolution of leachate chemistry and the mineralogical transformations of MSWI bottom ash over 10 years. Data interpretation is supported by geochemical modeling in terms of main pH-buffering processes. The leachate pH and concentrations in major elements (Ca, Na and Cl) as well as in Al and heavy metals (Cu, Pb and Zn) quickly drop during the first 2 years to asymptotically reach a set of minimum values over 10 years; similar to those of a reference road built with natural calcareous aggregates. SO(4) release makes exception with a slightly increasing trend over time. Carbonation induced by CO(2) inputs, which leads to the successive dissolution of portlandite, CSH and ettringite, is one of the main phenomenon responsible for the geochemical evolution of leachate. On the other hand, mineralogical observations and batch tests demonstrate a relative stability of the MSWI bottom ash inside the subbase layer. In particular, carbonation may be far to be completed and still in progress after 10 years. This is consistent with preferential rainwater flow and dilution at the road edges combined to diffusion inside the subbase layer. PMID:19733006

  5. Potential usage of fly and bottom ash from thermal power plant ”Nikola Tesla” landfill, Serbia

    Directory of Open Access Journals (Sweden)

    Čudić Vladica V.

    2012-01-01

    Full Text Available In Serbia, the ash from power plants has long been labelled as hazardous waste. With the adoption of the appropriate legislation this ash became secondary raw material with the potential usage. In this paper an analysis of the fly and bottom ash composition, which are disposed of in the power plant “Nikola Tesla A” landfill, is presented. Thirty samples, divided into three sets, were analyzed for trace elements As, Ba, Be, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Ti, V and Zn. The first and second set of samples were taken at the depth of 0.0-0.6 m, from cassette III, at the place of waste discharge (set I and in the centre of the cassette (set II.The third set of samples was taken from the same cassette spot but at the different depth. The estimated variations in quality within individual sets, as well as the comparison between sets I and II, were done. The repeatability of results by the depth of cassette (set III was also analyzed. The mixture consisting of 79.4% limestone, 17% clay, 0.5% sand, 0.55% iron ore, 0.55% from steel mill waste and 2% ash from the thermal power plant "Nikola Tesla A" was adopted as the reputable mixture for cement making. For concrete making, the same cement mixture was used but with 2.1% of the same ash material added. The results showed possibility of further fly and bottom ash use as the cement and concrete material.

  6. COMPARATIVE STUDY OF HEAVY METALS IN BOTTOM ASH FROM INCINERATORS AND OPEN PIT FROM HEALTHCARE FACILITIES IN GHANA

    Directory of Open Access Journals (Sweden)

    Richard Amfo-Otua

    2015-03-01

    Full Text Available Treatment of healthcare waste either by incinerating or open burning in a pit produces bottom ashes which contains heavy metals and other chemicals which are toxic, persistent and accumulate in the food chain resulting in adverse health effects in human and the environment. The study investigated the level of heavy metals in the ashes of thermally treated medical waste from four health care facilities in Ghana. Two batch of the ash samples were collected from two hospital incinerators and the other two from medical waste burnt in an open-pit. The samples were collected on different days but within the same month, stored and transported to Water Research Institute laboratory for heavy metals analysis. The concentrations of Pb, Cd, Cr and Hg were assessed using Atomic Absorption Spectrophotometry (AAS. The results proved that the concentrations of heavy metals were higher for the waste treated in the incinerator than those burnt in the open pit. The average concentration of the metals in the ashes were in the following decreasing order Pb>Cr>Hg>Cd. The mean concentration of Pb from the incinerated bottom ash was 147.5mg/kg and Cd was 2.5mg/kg whilst the open pit was (69.67mg/kg and (1.34mg/kg respectively. All the metals investigated exceeded the Dutch and Danish limit values for maximum permissible levels of heavy metals in good soil quality and therefore classified as harmful and toxic and therefore proper attention should be given to the ash disposal at the landfill sites.

  7. Development of a sintering process for recycling oil shale fly ash and municipal solid waste incineration bottom ash into glass ceramic composite.

    Science.gov (United States)

    Zhang, Zhikun; Zhang, Lei; Li, Aimin

    2015-04-01

    Oil shale fly ash and municipal solid waste incineration bottom ash are industrial and municipal by-products that require further treatment before disposal to avoid polluting the environment. In the study, they were mixed and vitrified into the slag by the melt-quench process. The obtained vitrified slag was then mixed with various percentages of oil shale fly ash and converted into glass ceramic composites by the subsequent sintering process. Differential thermal analysis was used to study the thermal characteristics and determine the sintering temperatures. X-ray diffraction analysis was used to analyze the crystalline phase compositions. Sintering shrinkage, weight loss on ignition, density and compressive strength were tested to determine the optimum preparation condition and study the co-sintering mechanism of vitrified amorphous slag and oil shale fly ash. The results showed the product performances increased with the increase of sintering temperatures and the proportion of vitrified slag to oil shale fly ash. Glass ceramic composite (vitrified slag content of 80%, oil shale fly ash content of 20%, sintering temperature of 1000 °C and sintering time of 2h) showed the properties of density of 1.92 ± 0.05 g/cm(3), weight loss on ignition of 6.14 ± 0.18%, sintering shrinkage of 22.06 ± 0.6% and compressive strength of 67 ± 14 MPa. The results indicated that it was a comparable waste-based material compared to previous researches. In particular, the energy consumption in the production process was reduced compared to conventional vitrification and sintering method. Chemical resistance and heavy metals leaching results of glass ceramic composites further confirmed the possibility of its engineering applications. PMID:25649918

  8. Physical and environmental properties of asphalt mixtures containing incinerator bottom ash.

    Science.gov (United States)

    Huang, Chin-Ming; Chiu, Chui-Te; Li, Kung-Cheh; Yang, Wan-Fa

    2006-10-11

    This paper presents parts of the results from a research project sponsored by Taiwan Environmental Protection Administration (TEPA), investigating both the physical and environmental properties of asphalt mixtures using different amount of incinerator bottom ash (IBA) as fine aggregate substitution. The Marshall mix design method was used to determine the design asphalt content and evaluate the potential performance of these IBA-asphalt mixtures. Water sensitivity and wheel track rutting were also performed on these mixtures. Leachates, from both laboratory and outdoor leaching tests, were performed to measure the concentration of selected heavy metals and the level of daphnia toxicity. While with adequate Marshall stability, the IBA-asphalt mixtures were shown to have excessively high Marshall flow and excessively low VMA (voids in the mineral aggregate). The results of the wheel tracking tests also indicated that the IBA-asphalt mixtures had low rutting resistance. The results of the water sensitivity test according to procedure of AASHTO T283 method showed that the IBA-asphalt mixtures had a higher tensile strength ratio (TSR) as compared with the conventional asphalt mixtures. Considering the environmental aspects, outdoor leaching tests showed that IBA had a high level of daphnia toxicity. From an ecological perspective, IBA could be identified as hazardous waste in Taiwan. However, after being mixed with asphalt binder, the concentration of heavy metals and the levels of daphnia toxicity were significantly reduced. The leachates of 10-day flat plate leaching tests on Marshall specimens containing IBA indicated that the heavy metal were undetectable and the daphnia toxicity was ineffective. PMID:16787702

  9. Reuse of MSWI bottom ash mixed with natural sodium bentonite as landfill cover material.

    Science.gov (United States)

    Puma, Sara; Marchese, Franco; Dominijanni, Andrea; Manassero, Mario

    2013-06-01

    The research described in this study had the aim of evaluating the reuse of incinerator slag, mixed with sodium bentonite, for landfill capping system components. A characterization was performed on pure bottom ash (BA) samples from an incinerator in the north of Italy. The results show that the BA samples had appropriate properties as covers. The compacted dry unit weight of the studied BA (16.2 kN m(-3)) was lower than the average value that characterizes most conventional fill materials and this can be considered advantageous for landfill cover systems, since the fill has to be placed on low bearing capacity ground or where long-term settlement is possible. Moreover, direct shear tests showed a friction angle of 43°, corresponding to excellent mechanical characteristics that can be considered an advantage against failure. The hydraulic conductivity tests indicated a steady-state value of 8 × 10(-10) m s(-1) for a mixture characterized by a bentonite content by weight of 10%, which was a factor 10 better than required by Italian legislation on landfill covers. The results from a swell index test indicated that fine bentonite swelled, even when divalent cations were released by the BA. The leaching behaviour of the mixture did not show any contamination issues and was far better than obtained for the pure BA. Thus, the BA-bentonite mixture qualified as a suitable material for landfill cover in Italy. Moreover, owing to the low release of toxic compounds, the proposed cover system would have no effect on the leachate quality in the landfill. PMID:23478909

  10. Potential Use of Malaysian Thermal Power Plants Coal Bottom Ash in Construction

    Directory of Open Access Journals (Sweden)

    Abdulhameed Umar Abubakar

    2012-11-01

    Full Text Available As Malaysia focuses its attention to the call for a “greener” culture, so did the engineers and those in the scientific community especially the construction industry who is a major contributor to the depletion of green house gases. The engineering and construction community has now taken up the challenge for the use of “green and recycled by-products” in construction. One of those by-products is the Coal Bottom Ash (CBA from thermal power plants that faces an increasing production running into hundreds of thousand tonnes in Malaysia alone, and its method of disposal is relegated to landfills alone with no other commercial usage. The construction industry is now forced to rethink on the utilization of the industrial by-products as supplementary materials due to the continuous depletion of natural aggregates in construction. A significant amount of research has been conducted elsewhere on CBA to ascertain its pozzolanic activity, compressive strength in concrete and mortar, durability, water absorption characteristics and density, in order to ensure its usage as a construction material. In this paper, a critical review of the strength characteristics of concrete and mortar as influenced by CBA as partial replacement of fine aggregate is presented based on the available information in the published literatures. Diverse physical and chemical properties of CBA from different power plants in Malaysia are also presented. The influence of different types, amounts and sources of CBA on the strength and bulk density of concrete is discussed. The setting time, workability and consistency as well as the advantages and disadvantages of using CBA in construction materials are also highlighted. An effective utilization of CBA in construction materials will significantly reduce the accumulation of the by-products in landfills and thus reduce environmental pollution.

  11. Measurement of uranium and thorium in coal fly ash and bottom ash samples from a thermal power plant by using a high resolution semiconductor detector

    International Nuclear Information System (INIS)

    A low background γ-ray detection system has been constructed for measuring the natural radioactivity in coal samples. It is based on a high-purity Ge detector mounted within a massive lead shield which reduces the normal background level by a factor of about 20. This makes it possible to measure the low intensity γ-rays from the natural radioactivity present in the samples. Using this equipment uranium and thorium concentrations in coal fly ash and bottom ash samples from a coal fired power plant located at Bathinda, India have been measured. The uranium activity found in the samples is within the range of concentrations observed in other countries while the thorium activity is found to be somewhat higher. (Author)

  12. Accelerated carbonation using municipal solid waste incinerator bottom ash and cold-rolling wastewater: Performance evaluation and reaction kinetics

    International Nuclear Information System (INIS)

    Highlights: • Carbonation was performed using CO2, wastewater and bottom ash in a slurry reactor. • A maximum capture capacity of 102 g CO2 per kg BA was achieved at mild conditions. • A maximum carbonation conversion of MSWI-BA was predicted to be 95% by RSM. • The CO2 emission from Bali incinerator could be expected to reduce by 6480 ton/y. • The process energy consumption per ton CO2 captured was estimated to be 180 kW h. - Abstract: Accelerated carbonation of alkaline wastes including municipal solid waste incinerator bottom ash (MSWI-BA) and the cold-rolling wastewater (CRW) was investigated for carbon dioxide (CO2) fixation under different operating conditions, i.e., reaction time, CO2 concentration, liquid-to-solid ratio, particle size, and CO2 flow rate. The MSWI-BA before and after carbonation process were analyzed by the thermogravimetry and differential scanning calorimetry, X-ray diffraction, and scanning electron microscopy equipped with energy dispersive X-ray spectroscopy. The MSWI-BA exhibits a high carbonation conversion of 90.7%, corresponding to a CO2 fixation capacity of 102 g per kg of ash. Meanwhile, the carbonation kinetics was evaluated by the shrinking core model. In addition, the effect of different operating parameters on carbonation conversion of MSWI-BA was statistically evaluated by response surface methodology (RSM) using experimental data to predict the maximum carbonation conversion. Furthermore, the amount of CO2 reduction and energy consumption for operating the proposed process in refuse incinerator were estimated. Capsule abstract: CO2 fixation process by alkaline wastes including bottom ash and cold-rolling wastewater was developed, which should be a viable method due to high conversion

  13. Accelerated carbonation using municipal solid waste incinerator bottom ash and cold-rolling wastewater: Performance evaluation and reaction kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Chang, E-E [Department of Biochemistry, Taipei Medical University, 250 Wu-Hsing Street, Taipei City, Taiwan 110, Taiwan, ROC (China); Pan, Shu-Yuan [Graduate Institute of Environmental Engineering, National Taiwan University, 71 Chou-Shan Rd., Taipei City, Taiwan 10673, Taiwan, ROC (China); Yang, Liuhanzi [School of Environment, Tsinghua University, Haidin District, Beijing 100084 (China); Chen, Yi-Hung [Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, 1, Sec. 3, Zhongxiao E. Rd., Taipei City, Taiwan 10608, Taiwan, ROC (China); Kim, Hyunook [Department of Energy and Environmental System Engineering, University of Seoul (Korea, Republic of); Chiang, Pen-Chi, E-mail: pcchiang@ntu.edu.tw [Graduate Institute of Environmental Engineering, National Taiwan University, 71 Chou-Shan Rd., Taipei City, Taiwan 10673, Taiwan, ROC (China)

    2015-09-15

    Highlights: • Carbonation was performed using CO{sub 2}, wastewater and bottom ash in a slurry reactor. • A maximum capture capacity of 102 g CO{sub 2} per kg BA was achieved at mild conditions. • A maximum carbonation conversion of MSWI-BA was predicted to be 95% by RSM. • The CO{sub 2} emission from Bali incinerator could be expected to reduce by 6480 ton/y. • The process energy consumption per ton CO{sub 2} captured was estimated to be 180 kW h. - Abstract: Accelerated carbonation of alkaline wastes including municipal solid waste incinerator bottom ash (MSWI-BA) and the cold-rolling wastewater (CRW) was investigated for carbon dioxide (CO{sub 2}) fixation under different operating conditions, i.e., reaction time, CO{sub 2} concentration, liquid-to-solid ratio, particle size, and CO{sub 2} flow rate. The MSWI-BA before and after carbonation process were analyzed by the thermogravimetry and differential scanning calorimetry, X-ray diffraction, and scanning electron microscopy equipped with energy dispersive X-ray spectroscopy. The MSWI-BA exhibits a high carbonation conversion of 90.7%, corresponding to a CO{sub 2} fixation capacity of 102 g per kg of ash. Meanwhile, the carbonation kinetics was evaluated by the shrinking core model. In addition, the effect of different operating parameters on carbonation conversion of MSWI-BA was statistically evaluated by response surface methodology (RSM) using experimental data to predict the maximum carbonation conversion. Furthermore, the amount of CO{sub 2} reduction and energy consumption for operating the proposed process in refuse incinerator were estimated. Capsule abstract: CO{sub 2} fixation process by alkaline wastes including bottom ash and cold-rolling wastewater was developed, which should be a viable method due to high conversion.

  14. Content and the forms of heavy metals in bottom sediments in the zone of industrial pollution sources ,

    Directory of Open Access Journals (Sweden)

    Voytyuk Y.Y.

    2014-12-01

    Full Text Available Regularities in the distribution of heavy metals in sediments in the zone of influence of the steel industry in Mariupol are installed. The study results of the forms of occurrence of Zn, Pb, Cu, Cr, Ni are represented. Ecological and geochemical assessment of sediment contamination by heavy metals is performed. The main sources of pollution of bottom sediments are air borne emissions from industrial plants, hydrogenous pollution in industrial sewage entering the water, sewage sludge, ash dumps, slag, ore, sludge, oil spills and salt solutions. Pollution hydrogenous sediments may be significant, contaminated sediments are a source of long-term contamination of water, even after cessation of discharges into rivers untreated wastewater. The environmental condition of bottom sediments in gross content of heavy metals is little information because they do not reflect the transformation and further migration to adjacent environment. The study forms of giving objective information for ecological and geochemical evaluation. The study forms of heavy metals in the sediments carried by successive extracts. Concentrations of heavy metals in the extracts determined by atomic absorption spectrometer analysis CAS-115. It was established that a number of elements typical of exceeding their content in bottom sediments of the background values, due likely to their technogenic origin. Man-made pollution of bottom sediments. Mariupol has disrupted the natural form of the ratio of heavy metals. In the studied sediments form ion exchange increased content of heavy metals, which contributes to their migration in the aquatic environment.

  15. Accelerated carbonation using municipal solid waste incinerator bottom ash and cold-rolling wastewater: Performance evaluation and reaction kinetics.

    Science.gov (United States)

    Chang, E-E; Pan, Shu-Yuan; Yang, Liuhanzi; Chen, Yi-Hung; Kim, Hyunook; Chiang, Pen-Chi

    2015-09-01

    Accelerated carbonation of alkaline wastes including municipal solid waste incinerator bottom ash (MSWI-BA) and the cold-rolling wastewater (CRW) was investigated for carbon dioxide (CO2) fixation under different operating conditions, i.e., reaction time, CO2 concentration, liquid-to-solid ratio, particle size, and CO2 flow rate. The MSWI-BA before and after carbonation process were analyzed by the thermogravimetry and differential scanning calorimetry, X-ray diffraction, and scanning electron microscopy equipped with energy dispersive X-ray spectroscopy. The MSWI-BA exhibits a high carbonation conversion of 90.7%, corresponding to a CO2 fixation capacity of 102g perkg of ash. Meanwhile, the carbonation kinetics was evaluated by the shrinking core model. In addition, the effect of different operating parameters on carbonation conversion of MSWI-BA was statistically evaluated by response surface methodology (RSM) using experimental data to predict the maximum carbonation conversion. Furthermore, the amount of CO2 reduction and energy consumption for operating the proposed process in refuse incinerator were estimated. Capsule abstract: CO2 fixation process by alkaline wastes including bottom ash and cold-rolling wastewater was developed, which should be a viable method due to high conversion. PMID:26025583

  16. Removal of uranium and gross radioactivity from coal bottom ash by CaCl2 roasting followed by HNO3 leaching

    International Nuclear Information System (INIS)

    Highlight: • Roasting the ash with CaCl2 enhanced the removal of uranium and gross radioactivity. • 87.3% of the total uranium was removed via the optimized roast-leach process. • Nearly 90% of gross α and β radioactivity was removed via the roast-leach process. • Molten CaCl2 promoted the incorporation of Ca and Al into Si-O matrices in ash. • Radionuclides were removed by the acid decomposition of newly formed silicates. - Abstract: A roast-leach method using CaCl2 and HNO3 to remove uranium and gross radioactivity in coal bottom ash was investigated. Heat treatment of the ash with 100% CaCl2 (900 °C, 2 h) significantly enhanced uranium leachability (>95%) compared with direct acid-leaching (22.6–25.5%). The removal efficiency of uranium and gross radioactivity increased steeply with increasing CaCl2 content, from 10% to 50%, and a HNO3 leaching time from 5 min to 1 h, but remained nearly constant or decreased slightly with increasing CaCl2 dosage >50% or acid-leaching time >1 h. The majority of the uranium (87.3%), gross α (92.9%) and gross β (84.9%) were removed under the optimized roast-leach conditions (50% CaCl2, 1 M HNO3 leaching for 1 h). The mineralogical characteristics of roasted clinker indicated that molten CaCl2 promoted the incorporation of Ca into silica and silicates and resulted in its progressive susceptibility to acid attack. Uranium and other radionuclides, most likely present in the form of silicates or in association with miscellaneous silicates in the highest density fraction (>2.5 g mL−1), were probably leached out as the result of the acid decomposition of newly formed “gelatinizing silicates”

  17. Use of leaching tests to quantify trace element release from waste to energy bottom ash amended pavements.

    Science.gov (United States)

    Roessler, Justin G; Townsend, Timothy G; Ferraro, Christopher C

    2015-12-30

    A series of roadway tests strips were paved on-site at a landfill in Florida, U.S. Waste to energy (WTE) bottom ash was used as a partial course aggregate replacement in a hot mix asphalt (HMA) and a Portland cement concrete (PCC) pavement, along with control HMA and PCC sections. This allowed for a comparison of the relative degree of leaching between both materials (HMA and PCC) as well as between the ash-amended and control pavements. Batch and monolithic tank leaching tests were conducted on the pavements. Testing of the PCC samples demonstrated that Mo and Al were elevated above regulatory thresholds for both the control and ash amended samples. Further leach testing demonstrated that the release of Mo was likely from the PCC and not a result of the inclusion of the BA into pavement. Batch leach testing of ash-amended HMA samples revealed Sb as a constituent of potential concern. The results of the monolith leaching test displayed leaching of Sb within the same order of magnitude as the regulatory threshold. Calculation of the leachability index (LI) for Sb found that it would have limited mobility when incorporated in the HMA matrix. PMID:26340550

  18. The effect of oxygen plasma ashing on the resistance of TiN bottom electrode for phase change memory

    International Nuclear Information System (INIS)

    Phase change memory (PCM) has been regarded as a promising candidate for the next generation of nonvolatile memory. To decrease the power required to reset the PCM cell, titanium nitride (TiN) is preferred to be used as the bottom electrode of PCM due to its low thermal and suitable electrical conductivity. However, during the manufacture of PCM cell in 40 nm process node, abnormally high and discrete distribution of the resistance of TiN bottom electrode was found, which might be induced by the surface oxidation of TiN bottom electrode during the photoresist ashing process by oxygen plasma. In this work, we have studied the oxidation of TiN and found that with the increasing oxygen plasma ashing time, the thickness of the TiO2 layer became thicker and the state of the TiO2 layer changed from amorphous to crystalline, respectively. The resistance of TiN electrode contact chain with 4-5 nm TiO2 layer was confirmed to be almost three-orders of magnitude higher than that of pure TiN electrode, which led to the failure issue of PCM cell. We efficiently removed the oxidation TiO2 layer by a chemical mechanical polishing (CMP) process, and we eventually recovered the resistance of TiN bottom electrode from 1 × 105 Ω/via back to 6 × 102 Ω/via and successfully achieved a uniform resistance distribution of the TiN bottom electrode. (paper)

  19. Improved electrical efficiency and bottom ash quality on waste combustion plants. Appendix A11 to A14

    Energy Technology Data Exchange (ETDEWEB)

    Hedegaard Madsen, O.; Boejer, M.; Jensen, Peter A.; Dam-Johansen, K.; Lundtorp, K. (Technical Univ. of Denmark, Kgs. Lyngby (Denmark)); Mogensen, Erhardt (Babcock and Wilcox Voelund A/S, Glostrup (Denmark))

    2010-07-01

    Investigations making it possible to evaluate and further develop concepts to improve electrical efficiency in a waste combustion plant were performed. Furthermore, one objective of the study was to investigate the possibilities of improving waste bottom ash leaching properties by use of a rotary kiln treatment. The project work included construction of a bench-scale rotary kiln, performing ash rotary kiln treatment experiments, conducting gas suction probe measurements on a waste incineration plant and making some concept evaluations. The influence of the rotary kiln thermal treatment on the leaching of Ca, Al, Si, Mg, Ba, Sr, Cl, Cu, Pb, Zn, Cr, Mo, sulfate, DOC and carbonate was determined. As a result of these tests, the rotary kiln thermal treatment of bottom ashes can be recommended for reducing the leaching of Cu, Pb, Cl, Zn and DOC; however, an increased leaching of Cr and Mo should be expected. The combustion conditions above the grate of a waste incineration plant were investigated and the release and concentration of volatile ash species in the flue gas such as Cl, Na, K, Ca, Pb, Zn and S were measured. The conducted measurements show that flue gas from grate sections 3 and 4 can produce a sufficiently hot flue gas that contains only low concentrations of corrosive species, and therefore can be used to increase superheater temperatures. Implementation of the so-called flue gas split concept together with other steam circle modifications on a waste combustion plant, and using a reasonable increase in final steam temperature from 400 to 500 deg. C, have the potential to increase electrical efficiency from 24 to 30% (with respect to lower fuel heating value) in a waste combustion plant. The appendices deal with electrical efficiency by dividing the combustion products; release of potentially corrosive constituents from the grate; CFD modeling of grate with and without vertical divider. (Author)

  20. Comparative study of ageing, heat treatment and accelerated carbonation for stabilization of municipal solid waste incineration bottom ash in view of reducing regulated heavy metal/metalloid leaching.

    Science.gov (United States)

    Santos, Rafael M; Mertens, Gilles; Salman, Muhammad; Cizer, Özlem; Van Gerven, Tom

    2013-10-15

    This study compared the performance of four different approaches for stabilization of regulated heavy metal and metalloid leaching from municipal solid waste incineration bottom ash (MSWI-BA): (i) short term (three months) heap ageing, (ii) heat treatment, (iii) accelerated moist carbonation, and (iv) accelerated pressurized slurry carbonation. Two distinct types of MSWI-BA were tested in this study: one originating from a moving-grate furnace incineration operation treating exclusively household refuse (sample B), and another originating from a fluid-bed furnace incineration operation that treats a mixture of household and light industrial wastes (sample F). The most abundant elements in the ashes were Si (20-27 wt.%) and Ca (16-19 wt.%), followed by significant quantities of Fe, Al, Na, S, K, Mg, Ti, and Cl. The main crystalline substances present in the fresh ashes were Quartz, Calcite, Apatite, Anhydrite and Gehlenite, while the amorphous fraction ranged from 56 to 73 wt.%. The leaching values of all samples were compared to the Flemish (NEN 7343) and the Walloon (DIN 38414) regulations from Belgium. Batch leaching of the fresh ashes at natural pH showed that seven elements exceeded at least one regulatory limit (Ba, Cr, Cu, Mo, Pb, Se and Zn), and that both ashes had excess basicity (pH > 12). Accelerated carbonation achieved significant reduction in ash basicity (9.3-9.9); lower than ageing (10.5-12.2) and heat treatment (11.1-12.1). For sample B, there was little distinction between the leaching results of ageing and accelerated carbonation with respect to regulatory limits; however carbonation achieved comparatively lower leaching levels. Heat treatment was especially detrimental to the leaching of Cr. For sample F, ageing was ineffective and heat treatment had marginally better results, while accelerated carbonation delivered the most effective performance, with slurry carbonation meeting all DIN limits. Slurry carbonation was deemed the most

  1. MSWI bottom ash used as basement at two pilot-scale roads: comparison of leachate chemistry and reactive transport modeling.

    Science.gov (United States)

    De Windt, Laurent; Dabo, David; Lidelöw, Sofia; Badreddine, Rabia; Lagerkvist, Anders

    2011-02-01

    The recycling of municipal solid waste incineration bottom ash as aggregates for road basement requires assessing the long-term evolution of leachate chemistry. The Dåva (Sweden) and Hérouville (France) pilot-scale roads were monitored during 6 and 10 years, respectively. Calculated saturation indices were combined to batch test modeling to set a simplified geochemical model of the bottom ash materials. A common reactive transport model was then applied to both sites. At Hérouville, pH and the concentration of most elements quickly drop during the first two years to reach a set of minimum values over 10 years. The decrease is less pronounced at Dåva. The evolutions of pH and major element concentrations are fairly well related to the following pH-buffering sequence: portlandite, C-S-H phases or pseudo-wollastonite and, finally, calcite in equilibrium with atmospheric CO(2). Al(OH)(3), barite, ettringite and monohydrocalcite may also control leachate chemistry. Cu release is correctly modeled by DOM complexation and tenorite equilibrium. Temperature has no significant effect on the modeling of leachate chemistry in the range 5-30°C, except at high pH. Effects at road edges and roadside slopes are important for the release of the less reactive elements and, possibly, for carbonation processes. PMID:20609573

  2. Assessment of Pb-slag, MSWI bottom ash and boiler and fly ash for using as a fine aggregate in cement mortar.

    Science.gov (United States)

    Saikia, Nabajyoti; Cornelis, Geert; Mertens, Gilles; Elsen, Jan; Van Balen, Koenraad; Van Gerven, Tom; Vandecasteele, Carlo

    2008-06-15

    Three types of wastes, metallurgical slag from Pb production (SLG), the sand-sized (0.1-2 mm) fraction of MSWI bottom ash from a grate furnace (SF), and boiler and fly ash from a fluidised bed incinerator (BFA), were characterized and used to replace the fine aggregate during preparation of cement mortar. The chemical and mineralogical behaviour of these wastes along with the reactivities of the wastes with lime and the hydration behaviour of ordinary Portland cement paste with and without these wastes added were evaluated by various chemical and instrumental techniques. The compressive strengths of the cement mortars containing waste as a partial substitution of fine aggregates were also assessed. Finally, leaching studies of the wastes and waste containing cement mortars were conducted. SLG addition does not show any adverse affect during the hydration of cement, or on the compressive strengths behaviours of mortars. Formation of expansive products like ettringite, aluminium hydroxide and H2 gas due to the reaction of some constituents of BFA and SF with alkali creates some cracks in the paste as well as in the cement mortars, which lower the compressive strength of the cement mortars. However, utilization of all materials in cement-based application significantly improves the leaching behaviour of the majority of the toxic elements compared to the waste as such. PMID:18068299

  3. The effect of oxygen plasma ashing on the resistance of TiN bottom electrode for phase change memory

    Science.gov (United States)

    Dan, Gao; Bo, Liu; Ying, Li; Zhitang, Song; Wanchun, Ren; Juntao, Li; Zhen, Xu; Shilong, Lü; Nanfei, Zhu; Jiadong, Ren; Yipeng, Zhan; Hanming, Wu; Songlin, Feng

    2015-05-01

    Phase change memory (PCM) has been regarded as a promising candidate for the next generation of nonvolatile memory. To decrease the power required to reset the PCM cell, titanium nitride (TiN) is preferred to be used as the bottom electrode of PCM due to its low thermal and suitable electrical conductivity. However, during the manufacture of PCM cell in 40 nm process node, abnormally high and discrete distribution of the resistance of TiN bottom electrode was found, which might be induced by the surface oxidation of TiN bottom electrode during the photoresist ashing process by oxygen plasma. In this work, we have studied the oxidation of TiN and found that with the increasing oxygen plasma ashing time, the thickness of the TiO2 layer became thicker and the state of the TiO2 layer changed from amorphous to crystalline, respectively. The resistance of TiN electrode contact chain with 4-5 nm TiO2 layer was confirmed to be almost three-orders of magnitude higher than that of pure TiN electrode, which led to the failure issue of PCM cell. We efficiently removed the oxidation TiO2 layer by a chemical mechanical polishing (CMP) process, and we eventually recovered the resistance of TiN bottom electrode from 1 × 105 Ω/via back to 6 × 102 Ω/via and successfully achieved a uniform resistance distribution of the TiN bottom electrode. Project supported by the National Key Basic Research Program of China (Nos. 2010CB934300, 2013CBA01900, 2011CBA00607, 2011CB932804), the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDA09020402), the National Integrate Circuit Research Program of China (No. 2009ZX02023-003), the National Natural Science Foundation of China (Nos. 61176122, 61106001, 61261160500, 61376006), and the Science and Technology Council of Shanghai (Nos. 12nm0503701, 13DZ2295700, 12QA1403900, 13ZR1447200).

  4. Removal of boron from ceramic industry wastewater by adsorption-flocculation mechanism using palm oil mill boiler (POMB) bottom ash and polymer.

    Science.gov (United States)

    Chong, Mei Fong; Lee, Kah Peng; Chieng, Hui Jiun; Syazwani Binti Ramli, Ili Izyan

    2009-07-01

    Boron is extensively used in the ceramic industry for enhancing mechanical strength of the tiles. The discharge of boron containing wastewater to the environment causes severe pollution problems. Boron is also dangerous for human consumption and causes organisms' reproductive impediments if the safe intake level is exceeded. Current methods to remove boron include ion-exchange, membrane filtration, precipitation-coagulation, biological and chemical treatment. These methods are costly to remove boron from the wastewater and hence infeasible for industrial wastewater treatment. In the present research, adsorption-flocculation mechanism is proposed for boron removal from ceramic wastewater by using Palm Oil Mill Boiler (POMB) bottom ash and long chain polymer or flocculant. Ceramic wastewater is turbid and milky in color which contains 15 mg/L of boron and 2000 mg/L of suspended solids. The optimum operating conditions for boron adsorption on POMB bottom ash and flocculation using polymer were investigated in the present research. Adsorption isotherm of boron on bottom ash was also investigated to evaluate the adsorption capacity. Adsorption isotherm modeling was conducted based on Langmuir and Freundlich isotherms. The results show that coarse POMB bottom ash with particle size larger than 2 mm is a suitable adsorbent where boron is removed up to 80% under the optimum conditions (pH=8.0, dosage=40 g bottom ash/300 ml wastewater, residence time=1h). The results also show that KP 1200 B cationic polymer is effective in flocculating the suspended solids while AP 120 C anionic polymer is effective in flocculating the bottom ash. The combined cationic and anionic polymers are able to clarify the ceramic wastewater under the optimum conditions (dosage of KP 1200 B cationic polymer=100 mg/L, dosage of AP 120 C anionic polymer=50 mg/L, mixing speed=200 rpm). Under the optimum operating conditions, the boron and suspended solids concentration of the treated wastewater were

  5. Leaching experiment of alkali-activated cementitious materials solidified forms of radioactive incineration ash

    International Nuclear Information System (INIS)

    In order to solidify safely radioactive incineration ash, the alkali-activated cementitious materials were prepared with slag, fly ash, cement and zeolite, with water glass or sodium silicate (sulfate) as the activator. The recommended formulation of solidification matrix is 65% (mass fraction, the same below) slag, 10% fly ash, 20% zeolite, 2% cement, 3% Ca (OH)2. Adding quantity of water glass is 5%, when addition of 30% radioactive incineration ash, with 0.34-0.35 of the ratio of water and ash, the mechanical property of solidification forms performs well. The leaching rate of U for the cement wastes forms is 6.0 x 10-6 cm/d in 35 d, and the long time leaching rate is very low. The results of diffusion coefficient of U in the solidification forms indicate that retention capability about U of alkali-activated cementitious materials si good. The leaching mechanisms of solidification forms are discussed. (authors)

  6. Metals accumulations during thermal processing of sewage sludge - characterization of bottom ash and air pollution control (APC) residues

    Science.gov (United States)

    Kasina, Monika; Kowalski, Piotr R.; Michalik, Marek

    2016-04-01

    Due to increasing mass of sewage sludge, problems in its management have appeared. Over years sewage sludge was landfilled, however due to EU directives concerning environmental issues this option is no longer possible. This type of material is considered hazardous due to highly concentrated metals and harmful elements, toxic organic substances and biological components (e.g. parasites, microbes). Currently in Europe, incineration is considered to be the most reasonable method for sewage sludge treatment. As a result of sludge incineration significant amount of energy is recovered due to high calorific value of sewage sludge but bottom ash and APC residues are being produced. In this study we show the preliminary results of chemical and mineral analyses of both bottom ash and APC residues produced in fluidized bed boiler in sewage sludge incineration plant in Poland, with a special emphasis on metals which, as a part of incombustible fraction can accumulate in the residual materials after thermal processing. The bottom ash was a SiO2-P2O5-Fe2O3-CaO-Al2O3 dominated material. Main mineral phases identified in X-ray diffraction patterns were: quartz, feldspar, hematite, and phosphates (apatite and scholzite). The bottom ash was characterized by high content of Zn - 4472 mg kg‑1, Cu - 665.5 mg kg‑1, Pb - 138 mg kg‑1, Ni - 119.5 mg kg‑1, and interestingly high content of Au - 0.858 mg kg‑1 The APC residues composition was dominated by soluble phases which represent more than 90% of the material. The XRD patterns indicated thenardite, halite, anhydrite, calcite and apatite as main mineral phases. The removal of soluble phases by dissolution in deionised water caused a significant mass reduction (ca. 3% of material remained on the filters). Calcite, apatite and quartz were main identified phases. The content of metals in insoluble material is relatively high: Zn - 6326 mg kg‑1, Pb - 514.3 mg kg‑1, Cu - 476.6 mg kg‑1, Ni - 43.3 mg kg‑1. The content of Cd

  7. Chemical characterization of bottom ashes generated during combustion of a Colombian mineral coal in a thermal power plant

    International Nuclear Information System (INIS)

    Bottom ashes generated during combustion of a mineral coal from Colombia were characterized by X-ray fluorescence spectrometry and X-ray diffraction. The interest in this particular coal is due to the fact that it will be used by a thermal power plant in Ceara, Northeastern Brazil, where it could produce over 900 tons of different residues/combustion products every day. Results from Xray fluorescence allowed identification and quantification of elements present in the sample: silicon (59,17%), aluminum (13,17%), iron (10,74%), potassium (6,11%), titanium (2,91%), calcium (4,97%), sulphur (0,84%) and others (2,09%). The X-ray diffraction revealed patterns from silica, mullite, calcium sulphate and hydrated sodium. Results obtained so far indicate that the material is a potential raw-material for use in the formulation of ceramic components (author)

  8. Corrosivity and leaching behavior of controlled low-strength material (CLSM) made using bottom ash and quarry dust.

    Science.gov (United States)

    Naganathan, Sivakumar; Razak, Hashim Abdul; Hamid, Siti Nadzriah Abdul

    2013-10-15

    This paper reports the corrosivity and leaching behavior of CLSM made using two different industrial wastes i.e. bottom ash from an incineration facility and quarry dust. The leachate samples were derived from fresh and hardened CLSM mixtures, and studied for leaching and electrical resistivity. The release of various contaminants and the consequent environmental impact caused by the contaminants were studied by the measurement of contaminants in the bleed, in the leachate at 28 days, and on the leachate derived from crushed block and whole block leaching done over a period of 126 days. Results indicated that the CLSM mixtures are non corrosive; diffusion was the leaching mechanism; and the contaminants were found to be moderate to low mobility. PMID:23845957

  9. Volcanic ash: What it is and how it forms

    Energy Technology Data Exchange (ETDEWEB)

    Heiken, G.

    1991-09-13

    There are four basic eruption processes that produce volcanic ash: (1) decompression of rising magma, gas bubble growth, and fragmentation of the foamy magma in the volcanic vent (magmatic), (2) explosive mixing of magma with ground or surface water (hydrovolcanic), (3) fragmentation of country rock during rapid expansion of steam and/or hot water (phreatic), and (4) breakup of lava fragments during rapid transport from the vent. Variations in eruption style and the characteristics of volcanic ashes produced during explosive eruptions depend on many factors, including magmatic temperature, gas content, viscosity and crystal content of the magma before eruption, the ratio of magma to ground or surface water, and physical properties of the rock enclosing the vent. Volcanic ash is composed of rock and mineral fragments, and glass shards, which is less than 2 mm in diameter. Glass shard shapes and sizes depend upon size and shape of gas bubbles present within the magma immediately before eruption and the processes responsible for fragmentation of the magma. Shards range from slightly curved, thin glass plates, which were broken from large, thin-walled spherical bubble walls, to hollow needles broken from pumiceous melts containing gas bubbles stretched by magma flow within the volcanic vent. Pumice fragments make up the coarser-grained portions of the glass fraction. Particle sizes range from meters for large blocks expelled near the volcanic vent to nanometers for fine ash and aerosol droplets within well-dispersed eruption plumes. 18 refs., 6 figs., 1 tab.

  10. Assessing the effects of municipal solid waste incinerator bottom ash on the decomposition of biodegradable waste using a completely mixed anaerobic reactor.

    Science.gov (United States)

    Banks, Charles J; Lo, Huang-Mu

    2003-06-01

    Experimental lab scale anaerobic reactors were used to assess the effect of municipal solid waste incinerator (MSWI) bottom ash on the process of biodegradation of organic materials typical of those found in municipal solid waste (MSW). Three reactors were used in the trial and each of these received the same daily organic load of simulated MSW but varying loads of MSWI bottom ash. The reactors were monitored over a period of 200 days for pH, alkalinity, volatile acids, total organic carbon (TOC), biogas production, gas composition and heavy metals. The addition of ash appeared to have beneficial effects on the degradation process as there was an increase in gas production, alkalinity, and pH, coupled with a decrease in the TOC concentration of leachate when compared with a control reactor without MSWI ash addition. After 200 days operation, the alkalinity and gas production in the anaerobic reactor receiving 6g ash per day was twice that of the reactor receiving 3g of ash per day and four times that of the control reactor. A number of tests were carried out on the ash sample to investigate the possible reasons for enhancement of the biodegradative process. These included a shake flask batch leaching test using distilled water, determination of the acid neutralising capacity by titration curve, and the quantification of six heavy metals and four light metals. In the reactors receiving ash the concentrations of Ca, Na, K, Mg ions were found to be significantly higher and these may provide a higher alkalinity which could promote the digestion process. Soluble concentrations of Cd, Cr, Cu, Ni, Pb, and Zn were in the range of 0.02-0.2, 0.01-2.5, 0.01-0.3, 0.01-1, 0.01-1.2, and 0.01-1 mgl(-1) respectively and at these concentrations it is unlikely that they would prove inhibitory to the digestion process. PMID:12870642

  11. Numerical Study on the Influence of Different Waving Bottom Form on the Fluid Surface Wave

    Directory of Open Access Journals (Sweden)

    Yongxin Zhu

    2013-05-01

    Full Text Available In the present study, the effect of waving bottom on the surface wave is studied. Basing on the fundamental equations of potential flow theory and boundary conditions, using the multiple scales perturbation method to derive the first-order and the second-order approximate equation which the fluid surface waves satisfied in the presence of waving bottom. Under the second-order approximation, the fluid surface waveform in first-order approximate equation is numerically simulated with MATLAB in the presence of different waving bottom form. The results show that: the fluid surface waveform is composed of a harmonic wave which has the same frequency with waving bottom and a pair of KdV solitary waves that spread to both the right and the left side when the waving bottom wave is a harmonic wave; and when the waving bottom is a solitary wave packet, it consists of a solitary wave which is closely related to the specific form of waving bottom and a couple of KdV solitary waves. With the development of time, three waves in fluid surface do not affect each other and they propagate independently. Thus it can be seen the waving bottom is effective for maintaining surface wave energy balance income and expenditure in the spreading process.

  12. Progress in forming bottom barriers under waste sites

    Energy Technology Data Exchange (ETDEWEB)

    Carter, E.E. [Carter Technologies, Sugar Land, TX (United States)

    1997-12-31

    The paper describes an new method for the construction, verification, and maintenance of underground vaults to isolate and contain radioactive burial sites without excavation or drilling in contaminated areas. The paper begins with a discussion of previous full-scale field tests of horizontal barrier tools which utilized high pressure jetting technology. This is followed by a discussion of the TECT process, which cuts with an abrasive cable instead of high pressure jets. The new method is potentially applicable to more soil types than previous methods and can form very thick barriers. Both processes are performed from the perimeter of a site and require no penetration or disturbance of the active waste area. The paper also describes long-term verification methods to monitor barrier integrity passively.

  13. Evaluation of the genotoxic, mutagenic and oxidant stress potentials of municipal solid waste incinerator bottom ash leachates

    Energy Technology Data Exchange (ETDEWEB)

    Radetski, C.M.; Ferrari, B.; Cotelle, S.; Masfaraud, J.-F.; Ferard, J.F

    2004-10-15

    Triplicate aqueous leachates of a municipal solid waste incineration bottom ash (MSWIBA) were produced according to a European standardised method. Leachates analysis showed relatively low concentrations (less than 1 mg{center_dot}l{sup -1}) for four metals (iron, cadmium, lead and copper). No mutagenic activity was revealed after performing the Salmonella/microsome assay with and without microsomal activation. With the Vicia root tip micronucleus assay, a significant increase in micronucleated cells was observed between 3.4% and 100% leachate concentration. Significant and elevated antioxidant stress enzyme activities, e.g., superoxide dismutase (SOD), catalase (CAT), peroxidase (PER) and glutathione reductase (GR), were detected in Vicia root tissues even at the lowest tested leachate concentration (i.e., 0.3%), whereas this was not always the case in leaf tissues, which showed tissue specificity for the tested enzymes. At the lowest concentration (i.e., 0.3%), a higher increase was observed (respectively 197% and 45% compared to the control) for root glutathione reductase and peroxidase activities over those of other enzymes (superoxide dismutase and catalase). Our results suggest that MSWIBA aqueous leachates need to be formally tested with genotoxic sensitive tests before recycling and support the hypothesis that plant genotoxicity is related to the cellular production of reactive oxygen species (ROS)

  14. Potential for leaching of heavy metals in open-burning bottom ash and soil from a non-engineered solid waste landfill.

    Science.gov (United States)

    Gwenzi, Willis; Gora, Dorcas; Chaukura, Nhamo; Tauro, Tonny

    2016-03-01

    Bottom ash from open-burning of municipal waste practised in developing countries poses a risk of heavy metal leaching into groundwater. Compared to incineration ash, there is limited information on heavy metal leaching from open-burning ash and soil from non-engineered landfills. Batch and column experiments were conducted to address three specific objectives; (1) to determine aqua regia extractable concentrations of heavy metals in fresh ash, old ash and soil from beneath the landfill, (2) to determine the relationship between heavy metal leaching, initial and final pH of leaching solution, and aqua regia extractable concentrations, and (3) to determine the breakthrough curves of heavy metals in ashes and soil. Aqua regia extractable concentrations of Cd, Zn, Mn, Cu, Ni and Pb were significantly higher (p landfill and uncontaminated soil (control). Increasing initial solution pH from 5 and 7 to 9 significantly reduced the mobility of Pb, Zn and Cu but not Cd whose mobility peaked at pH 7 and 9. Concentrations of desorbed heavy metals were not correlated with aqua regia extractable concentrations. Final pH of leachate rebounded to close to original pH of the material, suggesting a putative high buffering capacity for all materials. Both batch and column leaching showed that concentrations of leached heavy metals were disproportionately lower (<5%) than aqua regia extractable concentrations in most cases. The retardation of heavy metals was further evidenced by sigmoidal breakthrough curves. Heavy metal retention was attributed to precipitation, pH-dependent adsorption and formation of insoluble organo-metallic complexes at near-neutral to alkaline pH. Overall, the risk of heavy metal leaching from ash and soil from the waste dump into groundwater was low. The high pH and the presence of Zn, Fe, Mn and Cu make ash an ideal low-cost liming material and source of micronutrients particularly on acidic soils prevalent in sub-Saharan Africa. PMID:26766350

  15. Quantification of the resource recovery potential of municipal solid waste incineration bottom ashes

    DEFF Research Database (Denmark)

    Allegrini, Elisa; Maresca, Alberto; Olsson, Mikael Emil;

    2014-01-01

    Municipal solid waste incineration (MSWI) plays an important role in many European waste management systems. However, increasing focus on resource criticality has raised concern regarding the possible loss of critical resources through MSWI. The primary form of solid output from waste incinerators...... lack of REE enrichment in BAs indicated that the post-incineration recovery of these resources may not be a likely option with current technology. Based on these results, it is recommended to focus on limiting REE-containing products in waste for incineration and improving pre-incineration sorting...

  16. Comparative study of ageing, heat treatment and accelerated carbonation for stabilization of municipal solid waste incineration bottom ash in view of reducing regulated heavy metal/metalloid leaching

    OpenAIRE

    Santos, Rafael; Mertens, Gilles; Salman, Muhammad; Cizer, Özlem; Gerven, Tom Van

    2013-01-01

    This study compared the performance of four different approaches for stabilization of regulated heavy metal and metalloid leaching from municipal solid waste incineration bottom ash (MSWI-BA): (i) short term (three months) heap ageing, (ii) heat treatment, (iii) accelerated moist carbonation, and (iv) accelerated pressurized slurry carbonation. Two distinct types of MSWI-BA were tested in this study: one originating from a moving-grate furnace incineration operation treating exclusively house...

  17. A Comparative Study of Fouling and Bottom Ash from Woody Biomass Combustion in a Fixed-Bed Small-Scale Boiler and Evaluation of the Analytical Techniques Used

    Directory of Open Access Journals (Sweden)

    Lara Febrero

    2015-05-01

    Full Text Available In this work, fouling and bottom ash were collected from a low-power boiler after wood pellet combustion and studied using several analytical techniques to characterize and compare samples from different areas and determine the suitability of the analysis techniques employed. TGA results indicated that the fouling contained a high amount of organic matter (70%. The XRF and SEM-EDS measurements revealed that Ca and K are the main inorganic elements and exhibit clear tendency in the content of Cl that is negligible in the bottom ash and increased as it penetrated into the innermost layers of the fouling. Calcite, magnesia and silica appeared as the major crystalline phases in all the samples. However, the bottom ash was primarily comprised of calcium silicates. The KCl behaved identically to the Cl, preferably appeared in the adhered fouling samples. This salt, which has a low melting point, condenses upon contact with the low temperature tube and played a crucial role in the early stages of fouling formation. XRD was the most useful technique applied, which provided a semi-quantitative determination of the crystalline phases. FTIR was proven to be inadequate for this type of sample. The XRF and SEM-EDS, techniques yield similar results despite being entirely different.

  18. Characterization of cement and bitumen waste forms containing simulated low-level waste incinerator ash

    International Nuclear Information System (INIS)

    Incinerator ash from the combustion of general trash and ion exchange resins was immobilized in cement and bitumen. Tests were conducted on the resulting waste forms to provide a data base for the acceptability of actual low-level waste forms. The testing was done in accordance with the US Nuclear Regulatory Commission Technical Position on Waste Form. Bitumen had a measured compressive strength of 130 psi and a leachability index of 13 as measured with the ANS 16.1 leach test procedure. Cement demonstrated a compressive strength of 1400 psi and a leachability index of 7. Both waste forms easily exceed the minimum compressive strength of 50 psi and leachability index of 6 specified in the Technical Position. Irradiation to 108 Rad and exposure to 31 thermal cycles ranging from +600) to -300C did not significantly impact these properties. Neither waste form supported bacterial or fungal growth as measured with ASTM G21 and G22 procedures. However, there is some indication of biodegradation due to co-metabolic processes. Concentration of organic complexants in leachates of the ash, cement and bitumen were too low to significantly affect the release of radionuclides from the waste forms. Neither bitumen nor cement containing incinerator ash caused any corrosion or degradation of potential container materials including steel, polyethylene and fiberglass. However, moist ash did cause corrosion of the steel

  19. Bottom-Up Molecular Tunneling Junctions Formed by Self-Assembly

    NARCIS (Netherlands)

    Zhang, Yanxi; Zhao, Zhiyuan; Fracasso, Davide; Chiechi, Ryan C

    2014-01-01

    This Minireview focuses on bottom-up molecular tunneling junctions - a fundamental component of molecular electronics - that are formed by self-assembly. These junctions are part of devices that, in part, fabricate themselves, and therefore, are particularly dependent on the chemistry of the molecul

  20. Bottom ash from fluidising bed boilers as filler material in district heating pipe culverts. Chemical and geotechnical characterisation; Pannsand som kringfyllnadsmaterial foer fjaerrvaermeroergravar. Kemisk och geoteknisk karaktaerisering av fluidbaeddsand

    Energy Technology Data Exchange (ETDEWEB)

    Pettersson, Roger; Rogbeck, Jan; Suer, Pascal

    2004-01-01

    Bottom ashes from fluid bed boilers have been characterised, both geotechnically and chemically, in order to investigate the possibility to use them as filler material in district heating pipe culverts. Bottom ashes from both biofuel boilers and waste boilers are represented in this project. The companies which ashes have been characterised are Sundsvall Energi AB, Sydkraft OestVaerme AB, Sydkraft MaelarVaerme AB, Eskilstuna Miljoe och Energi, Stora Enso Fors, Soederenergi and Fortum Vaerme. A total of ten ashes have been analysed where three ashes originates from Sundsvall Energi AB, two from Sydkraft OestVaerme AB and one from the each of the remaining companies. The chemical analyses have been performed both on fresh ashes and on ashes aged for three months. The geotechnical analyses performed are grain size distribution, packing abilities and permeability. Chemical analyses performed are total content, available content, leaching tests (leaching both by shaking method and column procedure) and organic analyses (PAH, EOX, TOC, dioxin and fenol). The geotechnical analyses show that the ashes fulfils the demands that are put on the filler material used in district heating pipe culverts. When using the ashes in applications, light compaction should be performed due to the risk of crushing the material which may cause an increased amount of fine material. The leachability of fine material is larger than for coarse material. The ashes are relatively insensitive to precipitation. Bio fuel based bottom ashes have a lower content of environmental affecting substances than waste fuel based ashes. This is also shown in the leaching analyses. The leaching water from fresh ashes contains a higher concentration of leachable components than aged ashes. When aged the pH in the ashes decreases due to carbon uptake and hydration and this makes metals as Pb, Cu, Cr and Zn less mobile. On the other hand, an increase in leachability of Sb, Mo and SO{sub 4} is shown when the ashes

  1. Radioisotopic assays of CoASH and carnitine and their acetylated forms in human skeletal muscle

    International Nuclear Information System (INIS)

    Radioisotopic assays for the determination of acetyl-CoA, CoASH, and acetylcarnitine have been modified for application to the amount of human muscle tissue that can be obtained by needle biopsy. In the last step common to all three methods, acetyl-CoA is condensed with [14C]oxaloacetate by citrate synthase to give [14C]-citrate. For determination of CoASH, CoASH is reacted with acetylphosphate in a reaction catalyzed by phosphotransacetylase to yield acetyl-CoA. In the assay for acetylcarnitine, acetylcarnitine is reacted with CoASH in a reaction catalyzed by carnitine acetyltransferase to form acetyl-CoA. Inclusion of new simple steps in the acetylcarnitine assay and conditions affecting the reliability of all three methods are also described. Acetylcarnitine and free carnitine levels in human rectus abdominis muscle were 3.0 +/- 1.5 (SD) and 13.5 +/- 4.0 mumol/g dry wt, respectively. Values for acetyl-CoA and CoASH were about 500-fold lower, 6.7 +/- 1.8 and 21 +/- 8.9 nmol/g dry wt, respectively. A strong correlation between acetylcarnitine (y) and short-chain acylcarnitine (x), determined as the difference between total and free carnitine, was found in biopsies from the vastus lateralis muscle obtained during intense muscular effort, y = 1.0x + 0.5; r = 0.976

  2. Experimental on fly ash recirculation with bottom feeding to improve the performance of a circulating fluidized bed boiler co-burning coal sludge

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Lunbo; Xu, Guiling; Liu, Daoyin; Chen, Xiaoping; Zhao, Changsui [Southeast Univ., Nanjing (China). School of Energy and Environment

    2013-07-01

    With the aim of reducing carbon content in fly ash, fly ash recirculation with bottom feeding (FARBF) technology was applied to a 75 t/h Circulating Fluidized Bed (CFB) boiler burning mixture of coal and coal sludge. And industrial experiments were carried out to investigate the influence of FARBF technology on the combustion performance and pollutant emission characteristics of the CFB boiler. Results show that as the recirculation rate of fly ash increases, the CFB dense bed temperature decreases while the furnace outlet temperature increases, and the temperature distribution in the furnace becomes uniform. Compared with the conditions without fly ash recirculation, the combustion efficiency increases from 92 to 95% when the recirculation rate increases to 8 t/h, and the desulfurization efficiency also increases significantly. As the recirculation rate increases, the emissions of NO and CO decrease, but the particulate emission increases. The present study indicates that FARBF technology can improve the combustion performance and desulfurization efficiency for the CFB boilers burning coal sludge, and this can bring large economical and environmental benefits in China.

  3. Immobilization of antimony in waste-to-energy bottom ash by addition of calcium and iron containing additives.

    Science.gov (United States)

    Van Caneghem, Jo; Verbinnen, Bram; Cornelis, Geert; de Wijs, Joost; Mulder, Rob; Billen, Pieter; Vandecasteele, Carlo

    2016-08-01

    The leaching of Sb from waste-to-energy (WtE) bottom ash (BA) often exceeds the Dutch limit value of 0.32mgkg(-1) for recycling of BA in open construction applications. From the immobilization mechanisms described in the literature, it could be concluded that both Ca and Fe play an important role in the immobilization of Sb in WtE BA. Therefore, Ca and Fe containing compounds were added to the samples of the sand fraction of WtE BA, which in contrast to the granulate fraction is not recyclable to date, and the effect on the Sb leaching was studied by means of batch leaching tests. Results showed that addition of 0.5 and 2.5% CaO, 5% CaCl2, 2.5% Fe2(SO4)3 and 1% FeCl3 decreased the Sb leaching from 0.62±0.02mgkgDM(-1) to 0.20±0.02, 0.083±0.044, 0.25±0.01, 0.27±0.002 and 0.29±0.02mgkgDM(-1), respectively. Due to the increase in pH from 11.41 to 12.53 when 2.5% CaO was added, Pb and Zn leaching increased and exceeded the respective leaching limits. Addition of 5% CaCO3 had almost no effect on the Sb leaching, as evidenced by the resulting 0.53mgkgDM(-1) leaching concentration. This paper shows a complementary enhancement of the effect of Ca and Fe, by comparing the aforementioned Sb leaching results with those of WtE BA with combined addition of 2.5% CaO or 5% CaCl2 with 2.5% Fe2(SO4)3 or 1% FeCl3. These lab scale results suggest that formation of romeites with a high Ca content and formation of iron antimonate (tripuhyite) with a very low solubility are the main immobilization mechanisms of Sb in WtE BA. Besides the pure compounds and their mixtures, also addition of 10% of two Ca and Fe containing residues of the steel industry, hereafter referred to as R1 and R2, was effective in decreasing the Sb leaching from WtE BA below the Dutch limit value for reuse in open construction applications. To evaluate the long term effect of the additives, pilot plots of WtE BA with 10% of R1 and 5% and 10% of R2 were built and samples were submitted to leaching tests at

  4. Preservation of natural aquatic ecosystems by application of bottom coal ash based bioreactor for in situ treatment of anthropogenic effluents

    Science.gov (United States)

    Anker, Y.; Nisnevitch, M.; Tal, M.; Cahan, R.; Michael, E.

    2012-12-01

    One consequence of global climate change is recharge decrease at sub tropical and Mediterranean regions to both the surface and the ground fresh water resources. As a general rule, when water source quantity is reduced, the level of salination, as well as chemical and biological pollutants, tends to increase. The situation is more severe whenever the drainage basin is (a) heavily populated from urban, industrial and agricultural areas, (b) has wide areas of thin or non soil cover and (c) has a karstic structure and morphology. These latter conditions are typical to many regions around the Middle East; whereas pollution hazard to Mid Eastern streams is greater than to those in more humid regions owing to their relative small size and poor dilution capacity. The consequence of this ongoing and increasing anthropogenic pollution is endangerment of natural aquatic habitats and due to decrease in fresh water supply availability also to human sustainability. The ecological impact may involve transition of ephemeral (Wadi) streams into intermittent ones with the accompanied biodiversity change or extinction once the pollution is extreme. The impact on indigenous human communities might be as severe owing to drinking water quality decrease and the consequent decrease id quantity as well as damage to dryland farming. In setting of operations applied to the Yarkon Taninim watershed (central Israel) management, a pilot biofilter facility for sustainable preservation and rehabilitation of natural fluvial ecosystems was tested. This biofilter is planned to operate through low impact concept assimilating natural treatment processes occurring during runoff recharge through a porous flow media. The facility is constructed out of several grain sizes of bottom coal ash aggregate, which was found to be a better microbial mats growing stratum, compared to common natural aggregates such as tuff and lime pebbles (and also has an EPA directive for wastewater treatment). The biofilter is

  5. Process development for the removal and recovery of hazardous dye erythrosine from wastewater by waste materials-Bottom Ash and De-Oiled Soya as adsorbents

    International Nuclear Information System (INIS)

    Erythrosine is a water-soluble xanthene class of dye. It is widely used as colorant in foods, textiles, drugs and cosmetics. It is highly toxic, causes various types of allergies, thyroid activities, carcinogenicity, DNA damage behaviour, neurotoxicity and xenoestrogen nature in the humans and animals. The photochemical and biochemical degradation of the erythrosine is not recommended due to formation of toxic by-products. The present paper is an attempt to remove erythrosine from wastewater using adsorption over Bottom Ash-a power plant waste and De-Oiled Soya-an agricultural waste. Under the batch studies, effect of concentration of dye, temperature, pH of the solution, dosage of adsorbents, sieve size of adsorbents, etc., have been studied for the uptake of the dye over both adsorbents. The adsorption process verifies Langmuir and Freundlich adsorption isotherms in both the cases and based on the data different thermodynamic parameters have been evaluated. Batch studies also include kinetic measurements, rate constant study, mass transfer behaviour and establishment of mechanistic pathway for both the cases. For the bulk removal of the dye column operations have been carried out and breakthrough capacities of the Bottom Ash and De-Oiled Soya columns have been calculated. Attempts have also been made for the recovery of the adsorbed dye from exhausted columns by eluting dilute NaOH and more than 90% of the dye was recovered

  6. Variation of the phytotoxicity of municipal solid waste incinerator bottom ash on wheat (Triticum aestivum L.) seed germination with leaching conditions.

    Science.gov (United States)

    Phoungthong, Khamphe; Zhang, Hua; Shao, Li-Ming; He, Pin-Jing

    2016-03-01

    Municipal solid waste incinerator bottom ash (MSWIBA) has long been regarded as an alternative building material in the construction industry. However, the pollutants contained in the bottom ash could potentially leach out and contaminate the local environment, which presents an obstacle to the reuse of the materials. To evaluate the environmental feasibility of using MSWIBA as a recycled material in construction, the leaching derived ecotoxicity was assessed. The leaching behavior of MSWIBA under various conditions, including the extractant type, leaching time, liquid-to-solid (L/S) ratio, and leachate pH were investigated, and the phytotoxicity of these leachates on wheat (Triticum aestivum L.) seed germination was determined. Moreover, the correlation between the germination index and the concentrations of various chemical constituents in the MSWIBA leachates was assessed using multivariate statistics with principal component analysis and Pearson's correlation analysis. It was found that, heavy metal concentrations in the leachate were pH and L/S ratio dependent, but were less affected by leaching time. Heavy metals were the main pollutants present in wheat seeds. Heavy metals (especially Ba, Cr, Cu and Pb) had a substantial inhibitory effect on wheat seed germination and root elongation. To safely use MSWIBA in construction, the potential risk and ecotoxicity of leached materials must be addressed. PMID:26745383

  7. Experience of the environmental impact in the use of MSWI bottom ash as subbase layer; Erfarenheter av miljoepaaverkan vid anvaendning av slaggrus som foerstaerkningslager

    Energy Technology Data Exchange (ETDEWEB)

    Flyhammar, Peter

    2008-12-15

    This report presents an evaluation of the environmental impact that the use of MSWI bottom ash as a subbase layer in asphalt parking spaces and drives can cause. The focus has been on the migration of mobile ions such as salts (chloride and sulfate), because these substances can be used as early indicators of the migration of contaminants. The results can be seen as a conservative assessment of other types of substances which are less soluble and mobile. The background of the project was that the Malmoe City Environmental Department wanted an evaluation of the environmental impact caused by the use of bottom ash in the area of Svaagertorp, just south of Malmoe urban area, because elevated levels of chloride and sulfate in water samples from several ground water pipes were found. In response to this request, Sysav Utveckling initiated a project to assess the environmental impact of the current object. At Svaagertorp, bottom ash has been used to build a number of parking spaces and drives. A relatively large amount of bottom ash (approximately 40 000 tons) have been used. The aim of the project was to investigate the environmental impacts of the use of bottom ash in construction projects. To achieve this objective, the project should describe and evaluate the importance of various sources of pollution (the source term) describe the mechanisms that control the migration of contaminants in the area describe the local environmental impact. The evaluation of the environmental consequences was based on a synthesis of several different field studies and analysis; resistivity soundings with cpt-probe, surface resistivity measurements with a measuring system of the type ABDEM Lund Imaging System, analysis of surface and ground water samples and analysis of soil samples and soil profiles. Numerical modeling of two simplified scenarios was used to support the interpretations of the results from field surveys. Environmental impacts at Svaagertorp The overall assessment within

  8. Heavy metal leaching from aerobic and anaerobic landfill bioreactors of co-disposed municipal solid waste incineration bottom ash and shredded low-organic residues

    International Nuclear Information System (INIS)

    In this study, heavy metal leaching from aerobic and anaerobic landfill bioreactor test cells for co-disposed municipal solid waste incineration (MSWI) bottom ash and shredded low-organic residues has been investigated. Test cells were operated for 1 year. Heavy metals which were comparatively higher in leachate of aerobic cell were copper (Cu), lead (Pb), boron (B), zinc (Zn), manganese (Mn) and iron (Fe), and those apparently lower were aluminum (Al), arsenic (As), molybdenum (Mo), and vanadium (V). However, no significant release of heavy metals under aerobic conditions was observed compared to anaerobic and control cells. Furthermore, there was no meaningful correlation between oxidation-reduction potential (ORP) and heavy metal concentrations in the leachates although some researchers speculate that aeration may result in excessive heavy metal leaching. No meaningful correlation between dissolved organic carbon (DOC) and leaching of Cu and Pb was another interesting observation. The only heavy metal that exceeded the state discharge limits (10 mg/l, to be enforced after April 2005) in the aerobic cell leachate samples was boron and there was no correlation between boron leaching and ORP. Higher B levels in aerobic cell should be due to comparatively lower pH values in this cell. However, it is anticipated that this slightly increased concentrations of B (maximum 25 mg/l) will not create a risk for bioreactor operation; rather it should be beneficial for long-term stability of the landfill through faster washout. It was concluded that aerobization of landfills of heavy metal rich MSWI bottom ash and shredded residues is possible with no dramatic increase in heavy metals in the leachate

  9. Ash and heavy metals in fluidized bed-combustion; Tuhka ja raskasmetallit puuperaeisen jaetteen kerrosleijupoltossa

    Energy Technology Data Exchange (ETDEWEB)

    Kaessi, T.; Aittoniemi, P. [IVO International, Vantaa (Finland)

    1996-12-01

    Combustion ashes and submicron fly ash particles were characterized in two industrial boilers (bubbling vs. circulating fluidized bed) burning paper mill deinking sludge and bark or wood as support fuel. Bulk samples from fly ash, circulating ash and bottom ash were analyzed. Fine particles in fly ash were monitored and sampled for microscopic studies. The mass size distribution of fly ash was measured and the chemical composition according to particle size was analyzed. The results showed that ash consists of large and friable clusters formed by sintering of small mineral particles originating from paper fillers. Very few ash particles were fused and they were found only among the smallest particles. No agglomerates of fused particles were found. If the residence time in furnace is long enough sintering may proceed further and ash structure grows more dense. No indication of ash vaporization was detected. These results were similar for bubbling and circulating fluidized bed boilers. (author)

  10. 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.

  11. Leaching of glass components and surrogate nuclides from glassy waste forms for radioactive incineration ash

    International Nuclear Information System (INIS)

    The applicability of vitrification technology to treat radioactive incineration ash was studied, especially in terms of leaching characteristics, by using several glassy waste forms which are fabricated with simulated incineration ash and base-glass at different mixing ratios. The ISO leaching test has been conducted for 820 days. Two semi-empirical models were applied to find out the dominant leaching mechanism of glass elements. Dissolution associated with diffusion was the dominant leaching mechanism and the elemental leaching characteristic depended upon its solubility in water. A theoretical leaching prediction model was applied to observe the long-term leaching behavior of major glass elements and surrogate nuclides. Diffusion coefficients and dissolution rate constants, the main parameters in the long-term prediction model, of glass elements and surrogates were obtained using short- and long-term experimental data. The model was found to be useful in predicting the long-term behavior of such elements in order to assess the stability of glassy waste forms. (author)

  12. Charm mass effects in the renormalization constants and the static form factors of the bottom quark

    International Nuclear Information System (INIS)

    In this thesis we consider the influence of the light-quark mass on heavy-quark observables in three-loop order. In chapter 2 we first summarize the mathematical tools, which make for us possible to calculate the Feynman integrals required for this analytically or numerically. These are two- and three-loop propagator diagrams with two different mass scales. We concentrate on the numerical calculation by means of the Mellin-Barnes method. In chapter 3 we calculate the mass renormalization constant for heavy quarks in the on-shell scheme under regardment of loop corrections by light massive quarks. From the ratio of this quantity to the known MS renormalization constant we obtain the mass ratio in both schemes. The choice of the renormalization scheme depends on the physical problem formulation. In order to put mass parameters from different shemes in relation the knowledge of this mass relation is necessary. We consider especially the bottom quark and show that the corrections by the mass of the charm quark are numerically important. We give then the ratio to the MS mass and pole mass to the 1S mass and show that also here the charm corrections are of importance. Finally we calculate the light-quark corrections in the wave-function renormalization constant of heavy and massless quarks. In chapter 4 we study the effect of the finite mass of light quarks on the anomalous magnetic moment of heavy quarks. Also here we pay attention mainly to the bottom quark. We show that we can the vertex diagrams required for this express by those calculated in chapter 2 and present the result in form of an expansion in the mass ratio Mc/Mb and approximation formulae. By specification of our results we can reproduce the effects of the electron mass on the anomalous magnetic moment of the muon. In chapter 5 finally we apply to the analogue of the magnetic moment in QCD, the chromomagnetic moment of the quark. We calculate also here the correction for the bottom quark by the charm mass

  13. Bench-scale synthesis of zeolite A from subbituminous coal ashes with high crystalline silica content

    Energy Technology Data Exchange (ETDEWEB)

    Chareonpanich, M.; Jullaphan, O.; Tang, C. [Kasetsart University, Bangkok (Thailand). Dept. of Chemical Engineering

    2011-01-15

    In this present work, fly ash and bottom ash with high crystalline silica content were obtained from the coal-fired boilers within the paper industries in Thailand. These coal ashes were used as the basic raw materials for synthetic zeolite production. The crystal type and crystallinity, specific surface area and pore size, and textural properties of zeolite products were characterized by using X-ray diffraction spectroscopy (XRD), N{sub 2} sorption analysis, and Scanning Electron Microscopy (SEM), respectively. It was found that sodalite octahydrate was selectively formed via the direct conventional (one-step) synthesis, whereas through a two-step, sodium silicate preparation and consecutive zeolite A synthesis process, 94 and 72 wt.% zeolite A products could be produced from the fly ash and bottom ash, respectively. The cation-exchange capacity (CEC) of fly ash and bottom ash-derived zeolite A products were closely similar to that of the commercial grade zeolite A.

  14. Chemical Forms of Heavy Metals in Bottom Sediments of the Mitręga Reservoir

    Science.gov (United States)

    Dąbrowska, Lidia

    2016-06-01

    Bottom sediments originating from the Mitręga water reservoir were studied. It was assayed, in what chemical forms heavy metals (zinc, copper, nickel, cadmium and lead) occur in sediments, using the method of sequential extraction BCR. According to the geochemical criteria with respect to the content of Zn, Cu and Ni, the sediments in all measuring points were classified as uncontaminated, however because of the Cd content - as moderately contaminated. The highest Cu and Ni content was found in the sediment collected in the southern part of the reservoir, 15 and 11 mg/kg d.m, respectively. In the case of Zn, Pb and Cd, the sediment collected at the outflow of the Mitręga river was the most contaminated; metal content amounted to 136; 35; 3 mg/kg d.m., respectively. Based on the conducted fractionation of heavy metals, it was found that the potential mobility of metals, hence the possibility of secondary pollution of the reservoir open water, are arranged in the following order: Zn> Cd> Ni> Cu ~ Pb.

  15. Influence of moisture content and temperature on degree of carbonation and the effect on Cu and Cr leaching from incineration bottom ash.

    Science.gov (United States)

    Lin, Wenlin Yvonne; Heng, Kim Soon; Sun, Xiaolong; Wang, Jing-Yuan

    2015-09-01

    This study investigated the influence of moisture content and temperature on the degree of carbonation of municipal solid waste (MSW) incineration bottom ash (IBA) from two different incineration plants in Singapore. The initial rate of carbonation was affected by the nominal moisture content used. Carbonation temperature seemed to play a part in changing the actual moisture content of IBA during carbonation, which in turn affected the degree of carbonation. Results showed that 2h of carbonation was sufficient for the samples to reach a relatively high degree of carbonation that was close to the degree of carbonation observed after 1week of carbonation. Both Cu and Cr leaching also showed significant reduction after only 2h of carbonation. Therefore, the optimum moisture content and temperature were selected based on 2h of carbonation. The optimum moisture content was 15% for both incineration plants while the optimum temperature was different for the two incineration plants, at 35°C and 50°C. The effect on Cu and Cr leaching from IBA after accelerated carbonation was evaluated as a function of carbonation time. Correlation coefficient, Pearson's R, was used to determine the dominant leaching mechanism. The reduction in Cu leaching was found to be contributed by both formation of carbonate mineral and reduction of DOC leaching. On the other hand, Cr leaching seemed to be dominantly controlled by pH. PMID:26077229

  16. 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.

  17. 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

  18. Application of Recycled Concrete Aggregates Containing Waste Glass Powder/Suspension and Bottom Ash as a Cement Component in Concrete

    OpenAIRE

    Kara, P

    2013-01-01

    The growing environmental concerns and the increasing scarcity of landfills encourage the recycling of industrial wastes and adopting environmentally friendly practices by rational usage of natural resources. The production of concrete with recycled aggregate and reduced cement volume is the most desirable form of achieving a closed life cycle as an ecological constructional material. This paper describes results of a study undertaken to examine the influence of recycled aggregates obta...

  19. Characteristics of fly ash and bottom ash from the municipal solid waste incineration plant in Shanghai%上海地区生活垃圾焚烧灰渣元素组成及微观特征研究

    Institute of Scientific and Technical Information of China (English)

    曹玲玲; 刘可; 曾建荣; 龙时磊; 包良满; 马陈燕; 李燕

    2014-01-01

    利用同步辐射X射线荧光法(Synchrotron radiation X-ray fluorescence,SR-XRF)、离子色谱(Ion Chromatography,IC)、扫描电镜及其能谱分析(Scanning electron microscopy and X-ray energy dispersive microanalysis,SEM-EDX)、同步辐射微束X射线荧光法(Synchrotron radiation micro-beam X-ray fluorescence,μ-XRF)等手段研究上海某垃圾焚烧厂生活垃圾焚烧产物飞灰(Fly ash,FA)、炉渣(Bottom ash,BA)的元素浓度、离子组成、微观形貌、元素面分布,采用电感耦合等离子体质谱(Inductively Coupled Plasma Mass Spectrometry,ICP-MS)和X射线吸收精细结构谱(X-ray absorption near-edge structure,XANES)研究灰渣中Pb的同位素比值和化学种态.研究发现,飞灰中多数金属元素浓度高于炉渣中的,Pb、Cd明显富集于飞灰中,元素的富集因子显示Pb、Cd、Cu、Zn等呈极度污染状态.灰渣中水溶性成分主要为Ca、Na、K的氯化盐和硫酸盐,飞灰中离子浓度普遍高于炉渣中的.飞灰颗粒相对于炉渣颗粒粒径小、表面粗糙,更易于重金属的吸附.灰渣颗粒物的元素Pb、Zn、Cu、Cr、Fe、Mn等并不是均匀分布的,而是呈现局部明显富集.飞灰和炉渣Pb的来源相似,化学种态相似,主要为PbCl2、PbS和PbO.生活垃圾在焚烧过程中元素的迁移分布与元素本身的特性、焚烧环境相关,上海地区生活垃圾焚烧飞灰是危险废弃物,需稳定化处理后才能填埋,炉渣的资源化利用必需经过预处理.

  20. Influence of bacteria on lanthanide and actinide transfer from specific soil components (humus, soil minerals and vitrified municipal solid waste incinerator bottom ash) to corn plants: Sr-Nd isotope evidence

    International Nuclear Information System (INIS)

    Experiments have been performed to test the stability of vitrified municipal solid waste (MSW) incinerator bottom ash under the presence of bacteria (Pseudomonas aeruginosa) and plants (corn). The substratum used for the plant growth was a humus-rich soil mixed with vitrified waste. For the first time, information on the stability of waste glasses in the presence of bacteria and plants is given. Results show that inoculated plant samples contained always about two times higher lanthanide and actinide element concentrations. Bacteria support the element transfer since plants growing in inoculated environment developed a smaller root system but have higher trace element concentrations. Compared with the substratum, plants are light rare earth element (LREE) enriched. The vitrified bottom ash has to some extent been corroded by bacteria and plant activities as indicated by the presence of Nd (REE) and Sr from the vitrified waste in the plants. 87Sr/86Sr and 143Nd/144Nd isotope ratios of plants and soil components allow the identification of the corroded soil components and confirm that bacteria accelerate the assimilation of elements from the vitrified bottom ash. These findings are of importance for landfill disposal scenarios, and similar experiments should be performed in order to better constrain the processes of microbially mediated alteration of the MSW glasses in the biosphere

  1. Characterisation of major component leaching and buffering capacity of RDF incineration and gasification bottom ash in relation to reuse or disposal scenarios.

    Science.gov (United States)

    Rocca, Stefania; van Zomeren, André; Costa, Giulia; Dijkstra, Joris J; Comans, Rob N J; Lombardi, Francesco

    2012-04-01

    Thermal treatment of refuse derived fuel (RDF) in waste-to-energy (WtE) plants is considered a promising solution to reduce waste volumes for disposal, while improving material and energy recovery from waste. Incineration is commonly applied for the energetic valorisation of RDF, although RDF gasification has also gained acceptance in recent years. In this study we focused on the environmental properties of bottom ash (BA) from an RDF incineration (RDF-I, operating temperature 850-1000°C) and a RDF gasification plant (RDF-G, operating temperature 1200-1400°C), by evaluating the total composition, mineralogy, buffering capacity, leaching behaviour (both at the material's own pH and as a function of pH) of both types of slag. In addition, buffering capacity results and pH-dependence leaching concentrations of major components obtained for both types of BA were analysed by geochemical modelling. Experimental results showed that the total content of major components for the two types of BA was fairly similar and possibly related to the characteristics of the RDF feedstock. However, significant differences in the contents of trace metals and salts were observed for the two BA samples as a result of the different operating conditions (i.e. temperature) adopted by the two RDF thermal treatment plants. Mineralogy analysis showed in fact that the RDF-I slag consisted of an assemblage of several crystalline phases while the RDF-G slag was mainly made up by amorphous glassy phases. The leached concentrations of major components (e.g. Ca, Si) at the natural pH of each type of slag did not reflect their total contents as a result of the partial solubility of the minerals in which these components were chemically bound. In addition, comparison of total contents with leached concentrations of minor elements (e.g. Pb, Cu) showed no obvious relationship for the two types of BA. According to the compliance leaching test results, the RDF-G BA would meet the limits of the Italian

  2. The Form is the Bottom Line, Yes, But Sometimesthe Bottom Line Alters the Form: A Reflection on the Departmental Process at UAM

    Directory of Open Access Journals (Sweden)

    Manuel Gil Antón

    2005-05-01

    Full Text Available In this work the departmental organization at higher education institutions is commented, not as a –better or worse– plan with upper intrinsic values, but as an organizational structure that, depending on its purpose, can offer an opportunity or excuses for organizational change. The experience of the Metropolitan Autonomous University is described (UAM, Mexico, as an institution that since its origin was born with a departmental structure and with a dot-matrix service of its departments. This work offers data of the first 13 years of life (1974-1987 of the Department of Sociology in UAM, at Azcapotzalco, as a sample of this kind of system. In the example, general characteristics of age, working conditions al income, academic degree al income, institution where were formed and their labor antecedents are shown. Also, the difficulties faced initially by the educators of this institution, due to their youth, are described; as well as the nostalgia of some departments about adopting traditional systems, used in practice. This is a work that offers suggestions for educational institutions who are interested in adopting the departmental model.

  3. The Vaendoera test road, Sweden: A case study of long-term properties of roads constructed with MSWI bottom ash; Projekt Vaendoera: En studie av laangtidsegenskaper hos vaegar anlagda med bottenaska fraan avfallsfoerbraenning

    Energy Technology Data Exchange (ETDEWEB)

    Bendz, David; Arm, Maria; Westberg, Gunnar; Sjoestrand, Karin; Lyth, Martin; Wik, Ola [Swedish Geotechnical Inst., Linkoeping (Sweden); Flyhammar, Peter [Lund Inst. of Technology (Sweden). Dept. of Water Resources Engineering

    2006-03-15

    The accumulated effects of leaching and aging in a subbase layer of bottom ash were investigated in this study. The paved test road were constructed in 1987 in Linkoeping, Sweden, and has been used until the start of this study. The objective of this study was to investigate: (i) the accumulated effects of leaching and aging (ii) the accumulated effects of load and aging on the geotechnical properties (iii) the prerequisites for separate excavation of the bottom ash for possible reuse. The study started in September 2003 and included tests with falling weight deflectometer, triax testing on undisturbed core samples of bottom ash, sampling for chemical analysis. Three trenches were excavated in the test road, samples of the subbase layer and the subgrade were taken in the shaft walls and brought to the laboratory for leaching tests (EN 12457-2) and extraction, respectively. The extraction procedure was used to estimate extractable and chemically available fractions. It was found that the steady increase of stiffness which had been detected by falling weight deflectometer during the first years after construction had ceased. The undisturbed samples showed stiffness comparable with recently produced bottom ash from the same incineration plant, but lower stiffness if compared with the reference material of crushed rock. The permanent deformation was significantly larger for the samples compared with the crushed rock and recent (1999-2001) bottom ash from other incineration plants. The spatial distribution patterns of leachable easily soluble constituents reveal the existence of horizontal gradients, directed from the center of the road towards the shoulders of the road. This implies that horizontal transport by diffusion is the rate limiting leaching process for all easily soluble constituents underneath the pavement in a road. The bottom ash that was used in the sub-base layer was fresh at the time of the construction of the test road with a pH of about 11. Measured p

  4. Effects of ash forming temperature on water-soluble fraction of biomass ash and it’s elements%成灰温度对三种生物质灰及其元素水溶性的影响

    Institute of Scientific and Technical Information of China (English)

    何芳; 于如军; 张毅; 朱继英; 高振强; 孙鹏

    2015-01-01

    生物质灰及灰中化学元素的水溶特性是其是否能作为肥料应用的主要指标,成灰温度会影响这些特性。该文试验研究了成灰温度在400~800℃范围内,3种主要农业废弃物麦秸、玉米秸、稻壳的灰的水溶性和灰中各元素的水溶性。结果表明:1)麦秸灰、玉米秸灰的水溶性明显高于稻壳灰,三者水溶性都随成灰温度增高而显著降低,温度从400升高到800℃,水溶性分别从48%,35%和12%降至约12%,8%和0。2)灰中水溶元素主要有K,Cl和S,其中,K和Cl的水溶性随着成灰温度升高而降低,而S的水溶性几乎不受成灰温度的影响。%The implementation of biomass ash as a fertilizer is beneficial to the sustainable development of agriculture because it can return the elements taken by the plants from soil during the growth. Water solubility of biomass ash together with its elements is a vital property for the fertilizer’s utilization. In this paper, the effects of ash forming temperature on the water solubility of biomass ash and its elements were investigated experimentally. Three typical types of agro-residues in China, i.e. wheat straw, corn stover and rice husk, were chosen for investigation. Materials were collected and the corresponding proximate and elemental analyses were performed. In preparation process, wheat straw and corn stover were milled into powder with the particle size of less than 1 mm. Ashes were prepared in a muffle furnace at different ash forming temperatures in the scope from 400 to 800℃with the temperature interval of 50℃. About 4-5 g of each sample powder and rice husk were put in the crucibles, heated from ambient temperature to ash forming temperature, and then kept at the ash forming temperature for 4 hours in the muffle furnace. After the temperature of the furnace dropped to less than 200℃, the ashes were taken out to the cabinet dryer, cooled to the ambient temperature, and then

  5. 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...

  6. 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...

  7. Application of the electrical characterization to the study of the hydrated phases of the cement with coal bottom ash; Aplicacion de la caracterizacion electrica al estudio de las fases hidratadas de cemento con adicion de escorias de centrales termicas

    Energy Technology Data Exchange (ETDEWEB)

    Menendez, E.; Frutos, J. de; Alvaro, A. M.

    2014-02-01

    The present paper investigates the influence of using Bottom and Fly Ash as partial replacement of cement in the hydration process. Through measurements of electrical impedance spectroscopy (EIS) and X -ray diffraction (XRD), we analyze from the early stages to the hydration process to the end. Values of EIS, XRD and its relation, are used to determine transformation of hydrated phases, and for each of the substitutions, is indicated as modified the hydrated phase as a function of time and compared it with the reference material. It also proves the relevance of using EIS measures in real time, and as non destructive testing to characterize the hydration process of these materials. (Author)

  8. Adsorption isotherms, kinetics and column operations for the removal of hazardous dye, Tartrazine from aqueous solutions using waste materials-Bottom Ash and De-Oiled Soya, as adsorbents

    International Nuclear Information System (INIS)

    Adsorbents, Bottom Ash (a power plant waste) and De-Oiled Soya (an agricultural waste) exhibit good efficacy to adsorb a highly toxic dye, Tartrazine. Through the batch technique equilibrium uptake of the dye is observed at different concentrations, pH of the solution, dosage of adsorbents and sieve size of adsorbents. Langmuir and Freundlich adsorption isotherms are successfully employed on both the adsorbents and on the basis of these models the thermodynamic parameters are evaluated. Kinetic investigations reveal that more than 50% adsorption of dye is achieved in about 1 h in both the cases, whereas, equilibrium establishment takes about 3-4 h. The linear plots obtained in rate constant and mass transfer studies further confirm the applicability of first order rate expression and mass transfer model, respectively. The kinetic data treated to identify rate controlling step of the ongoing adsorption processes indicate that for both the systems, particle diffusion process is predominant at higher concentrations, while film diffusion takes place at lower concentrations. The column studies reveal that about 96% saturation of both the columns is attained during their exhaustion, while about 88 and 84% of the dye material is recovered by eluting dilute NaOH solution through exhausted Bottom Ash and De-Oiled Soya columns, respectively

  9. Carbon dioxide binding in the heterogeneous systems formed at combustion of oil shale. 3 transformations in the system suspension of ash - flue gases

    International Nuclear Information System (INIS)

    Power production based on oil shale combustion is accompanied by high carbon dioxide emissions and by the formation of alkaline waste ash. A set of laboratory experiments was carried out in order to investigate the interactions in the heterogeneous system: water suspension of ash-flue gases. Suspensions of ash were treated with model gases imitating the content of CO2 and SO2 in flue gases and air. Comparative experiments were carried out using the model system: suspension of pure CaO-flue gases. The aim of the experiments was to achieve the complete carbonation of oil shale ash by CO2 from flue gases. Experiments indicated that ash can be completely carbonated if the pH value of suspensions decreases to 9-7. The total amount of bound CO2 reached up to 153.8 kg per ton of oil shale ash or 70.8 kg per ton of oil shale burnt for electricity production. The part of bound CO2 formed 35.6 and 7.3 % from the carbonate and total emission of CO2, respectively. Due to carbon dioxide binding, alkaline ash will be chemically stabilized and its hazardous environmental effect decreased. (author)

  10. Effect of silica forms in rice husk ash on the properties of concrete

    Science.gov (United States)

    Bui, Le Anh-Tuan; Chen, Chun-Tsun; Hwang, Chao-Lung; Wu, Wei-Sheng

    2012-03-01

    The strength and durability properties of concrete with or without three types of rice husk ash (RHA), namely, amorphous, partial crystalline, and crystalline RHA, were investigates. The three types of RHA were added into concrete at a 20% replacement level. Consequently, the pozzolanic reactivity of amorphous RHA was higher than that of partial crystalline and crystalline RHA. Concrete added with amorphous RHA showed excellent characteristics in its mechanical and durability properties. The results showed that the higher the amount of crystalline silica in RHA, the lower the concrete resistivity value became. When compared with each other, concretes with 20% of the cement replaced with these types of RHA achieved similar ultrasonic pulse velocity values, but all were lower than that of the control concrete. The incorporation of these kinds of RHA significantly reduced chloride penetration. The results not only encourage the use of amorphous materials, they also support the application of crystalline or partial crystalline RHA as mineral and pozzolanic admixtures for cement.

  11. Environmental assessment of the reuse of municipal solid waste incineration bottom ash in quarry backfilling; Evaluation environnementale de la valorisation de machefers d'incineration d'ordures menageres en remplissage de carriere

    Energy Technology Data Exchange (ETDEWEB)

    Brons-Laot, G.

    2002-10-15

    The leaching behaviour of three different MSWI bottom ashes-based materials containing hydraulic binders is assessed in the conditions specified by the quarry backfilling application. An adapted approach methodology is applied: - physical, mineralogical and chemical characterizations of materials, - use of parametric tests to determine the effect of main scenarios factors on the release, - chemical modelling based on mineralogical and experimental leaching data with geochemical calculation codes, - chemical reaction / transport coupled modelling. The main results demonstrate that: - the batch and dynamic tests allow to obtain enough data to model and to predict the long term behaviour, - the chemical modelling of the solid / liquid equilibrium permits the determination of the chemical reactions involved and the prediction of pollutants solubilization in different chemical contexts, - the new materials (source term) present a low environmental impact in the conditions specified by the considered scenarios. (author)

  12. 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

  13. 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

    A sustainable production of energy crops requires that the loss of mineral nutrients when removing biomass is compensated naturally or by an addition of plant nutrients. Recycling ash is a natural way to satisfy this need arising after combustion of energy crops. In this pre-study, the prerequisites for recycling straw ash have been investigated. The Danish experience with spreading ash to fields and information in literature on the composition of ash have been collected and presented. Analysis of straw samples taken from four different places in Scania yielded information on cadmium and nutrient concentration in straw and in ash. A balance between removal of nutrient and cadmium with wheat straw and restoring them by recycling straw ash has been computed. Straw ash is a potassium fertiliser with some phosphorus and some liming effect. It is technically difficult to spread the small quantities of ash in solid form, ca 250 kg per hectare and year in average, which a pure recycling would require. It is easier to spread larger quantities, e.g. ca 1 ton per hectare every fourth year, which corresponds to spreading once in a four year crop rotation, but then one provides too much potassium if one considers the actual needs of the coming crops at that occasion, which could lead to potassium being leached out on light soils. Alternatively, one could spread only bottom ash, but this would lead to half of the potassium content not being recycled to agricultural soil and lost with the fly ash that is disposed of. If one spreads about 500 kg bottom ash per hectare every other year, which could be a suitable strategy to avoid overloading soils with potassium, the dose brought to 1 ha may be computed as: 4 - 10 kg phosphorus, 50 - 100 kg potassium, 5 - 15 kg sulphur, 4 - 8 kg magnesium, 0.1 - 0.3 kg manganese and 20 - 40 kg CaO. These basis of these calculations is the results from the analyses performed in this study. The cadmium concentration was significantly higher in wheat

  14. 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

    In recent years, explosions have occurred in certain phases of ash handling in Sweden. Investigations have revealed that hydrogen may have been present in all cases. The hydrogen is believed to be generated by chemical reactions of aluminium and other metals within the ash in the presence of water. The purpose with this study is to increase the knowledge of gas generation of incinerator ash. Thereby, guides for appropriate ash management can be introduced and the risk for further explosions prevented. The study has comprised analyses of the ash properties, such as chemical and physical composition and the pH, of ash from 14 incineration plants (mostly waste incineration plants). Different fractions of ash materials representing different parts of the process in each plant have been analysed. Furthermore, the fuel and the technical differences between the plants have been analysed. A tool for measuring the gas generation in the laboratory has been developed and the gas generation of the different ash materials at natural and increased pH was measured. Gas analyses and thermodynamic calculations have also been performed. The results showed that: bottom ash from fluidised bed boilers generated small amounts of gas at increased pH, much smaller amounts than the idle pass, cyclone and filter ash did, bottom ash from grate fired boilers generated more gas at increased pH than their cyclone ash and filter ash, with exception of the Linkoeping plant, all bio waste incineration plants generated ash with low gas generation potential, all fly ash materials with a gas generation potential of more than 10 l/kg originated from municipal waste incineration plants, filter ash that had been stored in oxygen rich environment generated significant less gas than fresh filter ash of the same origin, hardly any other gases were generated apart from hydrogen (very small amounts of acetone, furane, benzene and most likely methane were detected in some of the ash materials), there were no

  15. A Middle Pennsylvanian (Bolsovian) peat-forming forest preserved in situ in volcanic ash of the Whetstone Horizon in the Radnice Basin, Czech Republic

    DEFF Research Database (Denmark)

    Opluštil, Stanislav; Pšenicka, Josef; Libertín, Milan;

    2009-01-01

    The precursory mire of the Middle Pennsylvanian (Bolsovian) Lower Radnice Coal was buried in situ by volcanic ash, preserving the taxonomic composition, spatial distribution, vertical strati¿cation, and synecology of this peat-forming ecosystem in extraordinary detail. Plant fossil remains...... represent the pre- eruption vegetation of the swamp, which resulted from accumulation of peat in a high-ash, planar (rheotrophic) mire situated in a narrow palaeovalley containing an active ¿uvial system. A tuff bed (the Belka) at the base of the volcaniclastic Whetstone Horizon was exposed in two...... contiguous excavations over an area of 50 m2 in the Radnice Basin of western Bohemia, Czech Republic. Twenty-seven morphotaxa were identi¿ed, representing 20 whole-plant species with a wide variety of growth forms. The canopy of the peat-forming community was dominated by Cordaites borassifolius trees...

  16. 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.

  17. 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.

  18. 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...

  19. 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

  20. Ash from cereal and rape straw used for heat production: liming effect and contents of plant nutrients and heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Sander, M.-L.; Andren, O. [Swedish University of Agricultural Sciences, Uppsala (Sweden). Dept. of Ecology and Environmental Research

    1997-01-01

    The composition of 79 samples of straw ash from seven heating plants in Sweden was analysed with the aim of evaluating straw ash as a fertilizer and liming agent. The variation in ash composition was explained mainly by ash fraction (bottom ash vs. fly ash) and straw type (wheat, barley, rye, rape) but also by heating plant. Compared with concentrations of Zn, Pb and Cd in bottom ash; levels in fly ash were 10-90 times higher. Fly ash also contained more Cu and K compared with bottom ash. The Cd/P ratio was 0.03 in bottom ash and 0.6 g Cd/kg P in fly ash. Ash from rape straw had a higher Ca content and liming effect compared with ash from cereal straw; e.g. the liming effect of rape ash was more than three times higher than that of wheat ash. The liming effect varied between 3.5 and 44% CaO and depended mainly on the Ca content. The average P content was 1.7% (0.2-4.4%) with slightly higher concentration in rape ash than in wheat ash. The potential for using straw ash as a fertilizer and liming agent is discussed. Compared with commercial fertilizers the use of bottom ash as a P fertilizer results in a lower addition of Cd. However, the total heavy metal content of straw ash poses a potential problem. 24 refs., 2 figs., 5 tabs.

  1. Leaching optimization of municipal solid waste incineration ash for resource recovery: A case study of Cu, Zn, Pb and Cd.

    Science.gov (United States)

    Tang, Jinfeng; Steenari, Britt-Marie

    2016-02-01

    Ash from municipal solid waste incineration (MSWI) may be quite cumbersome to handle. Some ash fractions contain organic pollutants, such as dioxins, as well as toxic metals. Additionally, some of the metals have a high value and are considered as critical to the industry. Recovery of copper, zinc and lead from MSWI ashes, for example, will not only provide valuable metals that would otherwise be landfilled but also give an ash residue with lower concentrations of toxic metals. In this work, fly ash and bottom ash from an MSWI facility was used for the study and optimization of metal leaching using different solutions (nitric acid, hydrochloric acid and sulfuric acid) and parameters (temperature, controlled pH value, leaching time, and liquid/solid ratio). It was found that hydrochloric acid is relatively efficient in solubilizing copper (68.2±6.3%) and zinc (80.8±5.3%) from the fly ash in less than 24h at 20°C. Efficient leaching of cadmium and lead (over 92% and 90% respectively) was also achieved. Bottom ash from the same combustion unit was also characterized and leached using acid. The metal yields were moderate and the leachates had a tendency to form a gelatinous precipitate, which indicates that the solutions were actually over-saturated with respect to some components. This gel formation will cause problems for further metal purification processes, e.g. solvent extraction. PMID:26463013

  2. Utilisation aspects of ashes and green liquor dregs from an integrated semichemical pulp and board mill

    Energy Technology Data Exchange (ETDEWEB)

    Manskinen, K.

    2013-09-01

    This thesis investigated the properties of bottom and fly ashes originating from a bubbling fluidised bed boiler (120 MW) using two different fuel mixtures (i.e. Fuel mixture A: coal, wood and peat; and B: wood and peat) and of the green liquor dregs originating from the associated semichemical pulp and board mill in relation to the potential utilisation of these residues from various aspects. The total concentrations of As, Cd, Cr, Cu, Ni, Pb, Zn and Hg in the bottom ashes were lower than the maximum allowable concentrations for these elements in forest fertilisers. The total Ca concentrations in bottom ashes A (2.4%; d.w.) and B (3.4%; d.w.) were lower than the legal requirement of 6.0% (d.w.) for ash used as a forest fertiliser. The total Ca concentrations in fly ashes A (6.4%; d.w.) and B (11.0%; d.w.) were higher than the minimum limit value of 6.0% (d.w.), but the concentration of As in fly ashes A (46.9 mg/kg d.w.) and B (41.3 mg/kg; d.w.) exceeded the maximum limit value of 40 mg/kg (d.w.). Only bottom ash B could be used as a forest fertiliser, provided some additional Ca is used. The bottom ashes both fulfilled the Finnish regulations on waste recovery in earth construction. Due to the elevated total concentration of PAH (23 mg/kg; d.w.) and extractable concentrations of Mo (3.9 mg/kg; d.w.) and Se (0.2 mg/kg; d.w.) in fly ash A, this residue cannot be used in covered structures. Due to the elevated concentration of PAH (90 mg/kg; d.w.) in fly ash B, this residue cannot be used in covered and paved structures. However, the utilisation of these residues as an earth construction agent is still possible, but an environmental permit would be required. According to the sequential extraction studies, extractable concentrations of most of the elements in the fly ash A were higher than those in the bottom ash A. The extractability of various elements, both in the bottom and fly ashes A, varied widely. Most of the elements did not occur as readily soluble and

  3. Utilization of ash fractions from alternative biofuels used in power plants

    Energy Technology Data Exchange (ETDEWEB)

    Nikolaisen, L.; Hinge, J.; Christensen, I. (Danish Technological Inst., Aarhus (Denmark)); Dahl, J. (Force Technology, Broendby (Denmark)); Arendt Jensen, P. (DTU-CHEC, Kgs. Lyngby (Denmark)); Soendergaard Birkmose, T. (Dansk Landbrugsraadgivning, Landscentret, Aarhus (Denmark)); Sander, B. (DONG Energy, Fredericia (Denmark)); Kristensen, O. (Kommunekemi A/S, Nyborg (Denmark))

    2008-07-15

    It is expected, that demand for the traditional biomass resources wood and straw will increase over the next years. In other projects a number of agro industrial waste products has been tested and characterized as fuels for power plants. The annual production in Denmark of these fuels is estimated at roughly 400.000 tons of Dry Matter per year, so the potential is substantial. The agro industrial biomass products include: Grain screening waste, pea shells, soy waste, cocoa waste, sugar beet waste, sunflower waste, shea waste, coffee waste, olive waste, rice shell waste, potato waste, pectin waste, carrageen waste, tobacco waste, rape seed waste and mash from breweries. In the PSO project 5075, 5 different types of fuel pellets was produced, which were rendered suitable for combustion in power plants. In this project, ash is produced from the above mentioned 5 mixtures together with another 2 mixtures produced especially for this project. From the 5 mixtures from PSO 5075, ash is produced at Danish Technological Institute's slag analyzer. These ash products are rendered comparable to ash from grate fired boilers at power plants. The ash/slag from the combustion in the slag analyzer was then grinded - thus resulting in a total of 5 ash products. At DTU CHEC's Entrained Flow Reactor, ash products from the 5+2 mixtures were produced. These ash products are rendered comparable to ash produced form suspension fired boilers at power plants. For each of the 7 mixtures, bottom-, cyclone and filter ash was taken out separately resulting in a total of 21 ash samples. The produced ashes have been evaluated for their properties as directly applied fertilizer. Furthermore, scenarios have been set up to assess the feasibility in producing artificial fertilizer from the ash products, based on known processes. In the main components the content of Na, S, Cl and K is significantly higher in filter ashes, whereas the content of Mg, Al, Si and Ca is significantly lower. The

  4. 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.

  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. Kinetic and equilibrium studies of the removal of ammonium ions from aqueous solution by rice husk ash-synthesized zeolite Y and powdered and granulated forms of mordenite

    International Nuclear Information System (INIS)

    The removal of ammonium from aqueous solutions using zeolite NaY prepared from a local agricultural waste, rice husk ash waste was investigated and a naturally occurring zeolite mordenite in powdered and granulated forms was used as comparison. Zeolite NaY and mordenite were well characterized by powder X-ray diffraction (XRD), energy dispersive X-ray (EDX) analysis and the total cation exchange capacity (CEC). CEC of the zeolites were measured as 3.15, 1.46 and 1.34 meq g-1 for zeolite Y, powdered mordenite and granular mordenite, respectively. Adsorption kinetics and equilibrium data for the removal of NH4+ ions were examined by fitting the experimental data to various models. Kinetic studies showed that the adsorption followed a pseudo-second-order reaction. The equilibrium pattern fits well with the Langmuir isotherm compared to the other isotherms. The monolayer adsorption capacity for zeolite Y (42.37 mg/g) was found to be higher than that powdered mordenite (15.13 mg/g) and granular mordenite (14.56 mg/g). Thus, it can be concluded that the low cost and economical rice husk ash-synthesized zeolite NaY could be a better sorbent for ammonium removal due to its rapid adsorption rate and higher adsorption capacity compared to natural mordenite.

  7. Kinetic and equilibrium studies of the removal of ammonium ions from aqueous solution by rice husk ash-synthesized zeolite Y and powdered and granulated forms of mordenite.

    Science.gov (United States)

    Yusof, Alias Mohd; Keat, Lee Kian; Ibrahim, Zaharah; Majid, Zaiton Abdul; Nizam, Nik Ahmad

    2010-02-15

    The removal of ammonium from aqueous solutions using zeolite NaY prepared from a local agricultural waste, rice husk ash waste was investigated and a naturally occurring zeolite mordenite in powdered and granulated forms was used as comparison. Zeolite NaY and mordenite were well characterized by powder X-ray diffraction (XRD), energy dispersive X-ray (EDX) analysis and the total cation exchange capacity (CEC). CEC of the zeolites were measured as 3.15, 1.46 and 1.34 meq g(-1) for zeolite Y, powdered mordenite and granular mordenite, respectively. Adsorption kinetics and equilibrium data for the removal of NH(4)(+) ions were examined by fitting the experimental data to various models. Kinetic studies showed that the adsorption followed a pseudo-second-order reaction. The equilibrium pattern fits well with the Langmuir isotherm compared to the other isotherms. The monolayer adsorption capacity for zeolite Y (42.37 mg/g) was found to be higher than that powdered mordenite (15.13 mg/g) and granular mordenite (14.56 mg/g). Thus, it can be concluded that the low cost and economical rice husk ash-synthesized zeolite NaY could be a better sorbent for ammonium removal due to its rapid adsorption rate and higher adsorption capacity compared to natural mordenite. PMID:19879040

  8. Kinetic and equilibrium studies of the removal of ammonium ions from aqueous solution by rice husk ash-synthesized zeolite Y and powdered and granulated forms of mordenite

    Energy Technology Data Exchange (ETDEWEB)

    Yusof, Alias Mohd, E-mail: alias@kimia.fs.utm.my [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Keat, Lee Kian [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Ibrahim, Zaharah [Faculty of Biosciences and Bioengineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Majid, Zaiton Abdul [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Nizam, Nik Ahmad [Faculty of Biosciences and Bioengineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia)

    2010-02-15

    The removal of ammonium from aqueous solutions using zeolite NaY prepared from a local agricultural waste, rice husk ash waste was investigated and a naturally occurring zeolite mordenite in powdered and granulated forms was used as comparison. Zeolite NaY and mordenite were well characterized by powder X-ray diffraction (XRD), energy dispersive X-ray (EDX) analysis and the total cation exchange capacity (CEC). CEC of the zeolites were measured as 3.15, 1.46 and 1.34 meq g{sup -1} for zeolite Y, powdered mordenite and granular mordenite, respectively. Adsorption kinetics and equilibrium data for the removal of NH{sub 4}{sup +} ions were examined by fitting the experimental data to various models. Kinetic studies showed that the adsorption followed a pseudo-second-order reaction. The equilibrium pattern fits well with the Langmuir isotherm compared to the other isotherms. The monolayer adsorption capacity for zeolite Y (42.37 mg/g) was found to be higher than that powdered mordenite (15.13 mg/g) and granular mordenite (14.56 mg/g). Thus, it can be concluded that the low cost and economical rice husk ash-synthesized zeolite NaY could be a better sorbent for ammonium removal due to its rapid adsorption rate and higher adsorption capacity compared to natural mordenite.

  9. Characteristics of Coal Ashes in Yanzhou Mining District and Distribution of Trace Elements in Them

    Institute of Scientific and Technical Information of China (English)

    刘桂建; 彭子成; 杨萍玥; 桂和荣; 王桂梁

    2001-01-01

    In the process of combustion of coal organic and inorganic materials in it will undergo a complex variation. Part of them will become volatiles and, together with coal smoke, enter into atmosphere, some will remain in micro-particulates such as ash and dust and find their way into atmosphere in the form of solid particles, and the rest will be retained in ash and slag. Coal ashes are the residues of organic and inorganic substances in coal left after coal combustion and the composition of coal ashes is dependent on that of minerals and organic matter in coal This paper deals with the chemical composition of coal ashes, the distribution of trace elements in them and their petrological characteristics, and also studies the relationship between the yield of coal ashes and the distribution of trace elements. In addition, a preliminary study is also under taken on the factors that affect the chemical composition of coal ashes. As viewed from the analyses of coal ash samples collected from the Yanzhou mining district, it can be seen clearly that coal ashes from the region studied are composed chiefly of crystalline materials, glassy ma terials and uncombusted organic matter and the major chemical compositions are SiO2, A12O3,Fe2O3, and CaO, as well as minor amounts of SO3, P2O5, Na2O, K2O and TiO2. During the combustion of coal, its trace elements will be redistributed and most of them are enriched in coal ashes. At the same time, the concentrations of the trace elements in flying ash are much higher than those of bottom ash, i.e. , with decreasing particle-size of coal ashes their concen trations will become higher and higher. So the contents of trace elements are negatively propor tional to the particle-size of coal ashes. There has been found a positive correlation between the trace elements Th, V, Zn, Cu and Pb and the yield of coal ashes while a negative correlation between C1 and the yield of coal ashes.

  10. Determination of Ash Mixture Properties and Construction of Test Embankment - Part B

    OpenAIRE

    Yoon, Sungmin; Balunaini, Umashankar; Prezzi, Monica; Salgado, Rodrigo; Siddiki, Nayyar Zia

    2006-01-01

    Class F fly ash and bottom ash are solid residue byproducts produced by coal-burning plants. They are usually disposed off with a typical disposal rate of 80 % fly ash and 20 % bottom ash. To maximize the use of the coal ash, and thus significantly reduce the disposal problem that electric utility companies and our society in general face, the direct use of ponded or landfilled ash that is composed of high proportions of fly ash would be desirable. However, a general understanding of the beha...

  11. Determination of Ash Mixture Properties and Construction of Test Embankment - Part A

    OpenAIRE

    Kim, Bumjoo; Yoon, Sungmin; Balunaini, Umashankar; Prezzi, Monica; Salgado, Rodrigo

    2006-01-01

    Class F fly ash and bottom ash are solid residue byproducts produced by coal-burning plants. They are usually disposed off with a typical disposal rate of 80 % fly ash and 20 % bottom ash. To maximize the use of the coal ash, and thus significantly reduce the disposal problem that electric utility companies and our society in general face, the direct use of ponded or landfilled ash that is composed of high proportions of fly ash would be desirable. However, a general understanding of the beha...

  12. Recovery of high purity zinc from filter ash produced during the thermal treatment of waste and inerting of residual materials.

    Science.gov (United States)

    Schlumberger, Stefan; Schuster, Michael; Ringmann, Stefan; Koralewska, Ralf

    2007-12-01

    The method described below recovers zinc, a valuable metal that is present in high concentrations in filter ash from the thermal treatment of waste, and returns the filter ash stripped of heavy metals to the combustion process in order to destroy organic substances. On an industrial scale, the heavy metals in the filter ash were mobilized by means of hydrochloric acid in the acidic fluids produced in the flue-gas scrubbing process without the addition of further chemicals. A pilot plant for implementing the selective reactive extraction (SRE) method on the ash extracts, using a highly selective complexant, was operated over a period of several months in order to obtain a concentrated, high-purity zinc salt solution (mono metal solution). A zinc depletion rate of 99.8% in the aqueous extract was achieved using mixer-settler units. The residual zinc concentration in the waste water was then 99.99% is then separated by means of electrolysis. To destroy organic substances present in the filter ash, particularly dioxins and furans, the extracted filter ash cake was returned to the combustion process together with household waste. Plant operation, raw and pure gas parameters, and quality of the bottom ash produced were not impacted by such recirculation. The profitability of the overall process is attributable both to the recovery of valuable zinc metal and to the cost savings made in waste water treatment and in the disposal of the waste combustion residues because the remaining mixture of filter ash and bottom ash can be reused in a combined form. This method therefore supports the sustainable and economically viable reuse of filter ash. PMID:18229749

  13. Elemental analysis of ash residue from combustion of CCA treated wood waste before and after electrodialytic extraction

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Ottosen, Lisbeth M.

    2006-01-01

    Element distribution in a combined fly ash and bottom ash from combustion of copper chromate arsenate (CCA) treated wood waste was investigated by scanning electron microscopy (SEM/EDX) before and after electrodialytic extraction. The untreated ash contained various particles, including pieces of...... incompletely combusted wood pieces and was also found in almost pure form in a surface layer of some matrix particles – indicating surface condensation of volatile Cu species. In treated ash, Ca and As were no longer found together, indicating that Ca-arsenates had been dissolved due to the electrodialytic...... incompletely combusted wood rich in Cr and Ca, and irregular particles rich in Si, Al and K. Cr was also found incorporated in silica-based matrix particles. As was associated with Ca in porous (char) particles, indicating that Ca-arsenates had been formed during combustion. Cu was associated with Cr in the...

  14. Element budgets of forest biomass combustion and ash fertilisation - a Danish case-study

    DEFF Research Database (Denmark)

    Ingerslev, Morten; Skov, Simon; Sevel, Lisbeth;

    2011-01-01

    the retention of various elements in the different ash fractions and utilise the nutrient recovery to evaluate the fertiliser quality of the examined ash. The mass and element flux of wood chips, bottom ash, cyclone fly ash and condensation sludge at Ebeltoft central heating plant was studied over a...

  15. Dissolution of hardened wood ash in forest soils. Studies in a column experiment

    International Nuclear Information System (INIS)

    Dissolution of hardened and crushed ashes was studied in a column experiment during leaching with artificial rain water corresponding to 5 year-precipitations. The ashes studied were a CFB ash from Perstorp and a bottom ash from Ljungby that were added in amounts corresponding to 4 tonnes per hectare. Assuming that the studied ashes are representative and that the results can be transferred to field conditions, the most important conclusions that can be drawn are summarized in the following way: Hardened and crushed ashes are broken down relatively slowly, which particularly applies to the coarse fraction. The fine fraction of the Perstorp ashes has a good liming effect at the same time as the risk for large pH-increases appears to be small. As regards the macro-nutrients Ca and K (not the Ljungby ashes), the amounts released are probably sufficient from a forest vitalization viewpoint. As regards Mg and P, this is less certain. The heavy metals appear to be released relatively slowly and most of them are bound in non-exchangeable form in the mor layer. The exception is Cd that tends to be absorbed in the mor layer to a minor extent but which, on the other hand, is not released from the ashes in any greater amounts. The greatest risk for increased concentrations of soluble heavy metals appears to be the mobilization of part of the mor layer's reserve as a result of the salt effect of the ashes. However, this is a temporary effect. 17 refs, 18 figs, 6 tabs Figs and tabs with text in English

  16. 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

  17. 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.

  18. 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.

  19. Polychlorobenzenes and polychlorinated biphenyls in ash and soil from several industrial areas in North Vietnam: residue concentrations, profiles and risk assessment.

    Science.gov (United States)

    Nguyen, Thi Hue; Nguyen, Thi Thu Thuy; Nguyen, Hoang Tung

    2016-04-01

    Polychlorinated benzenes (PCBzs) including penta- and hexachlorobenzene can be unintentionally formed from thermal processes in different industrial activities, and very little information is available on the contamination and emission characteristics of these new persistent organic pollutants from industries in Vietnam. In this study, contamination of PCBzs (including penta- and hexachlorobenzene, named PeCBz and HCB, respectively) and PCBs (including CB-28, 52, 101, 153, 138, 180) in fly ash, bottom ash and soil from combustion processes of waste incineration, metallurgy (steel making and zinc production) and cement production from several provinces in the Northern Vietnam, including Hai Duong, Hanoi, Bac Ninh, Hai Phong and Thai Nguyen, was preliminary investigated. The PCBzs concentrations in fly ash, bottom ash and soil ranged from 2.7 to 100 ng g(-1), from 2.7 to 159 ng g(-1) and from 0.28 to 33.9 ng g(-1), respectively. Relatively high residues of PeCBz in fly ash and bottom ash from municipal waste incinerators in some provinces from the Northern Vietnam were encountered. Total PCBs concentrations ranged from 18.0 to 8260 ng g(-1), from 1.0 to 10600 ng g(-1) and from 14.5 to 130 ng g(-1) for the fly ash, bottom ash and soil, respectively. Daily intakes of PeCBz, HCB and PCBs through soil ingestion and dermal exposure estimated for children ranged 0.33-9.93 (mean 3.14), 0.39-21.1 (mean 4.9) and 6.09-1530 ng/kg bw/day (mean 346), respectively; and these intakes were about 4.7-5.4 times higher than those estimated for adult. The intakes of PeCBz and HCB were relatively low, while those for PCBs exceeded WHO TDI for some samples. PMID:26049895

  20. Hymenoscyphus fraxineus vs. Hymenoscyphus albidus – A comparative light microscopic study on the causal agent of European ash dieback and related foliicolous, stroma-forming species

    Science.gov (United States)

    Baral, Hans-Otto; Bemmann, Martin

    2014-01-01

    Five species of Hymenoscyphus that fruit on black stromatized parts of dead leaves of deciduous trees are presented, giving details on their morphological and ecological characteristics. Several of these species have previously been misplaced in rutstroemiaceous genera because of the presence of a substratal stroma. However, the heteropolar, scutuloid ascospores with an often hook-like lateral protrusion at the rounded apex and the ascus apical ring of the Hymenoscyphus-type represent two reliable morphological characteristics that, together with molecular data, provide clear evidence for their placement in the genus Hymenoscyphus (Helotiaceae). Among the species treated is Hymenoscyphus fraxineus (=Hymenoscyphus pseudoalbidus), the causal agent of the European ash dieback disease. Since 1992 this species started within Europe to replace the rather uncommon Hymenoscyphus albidus, which is likewise confined to leaves of Fraxinus. Hy. fraxineus has been recorded already since 1990 in Eastern Asia (Japan, Korea, northeast of China), where it had been initially misidentified as Lambertella albida (≡Hy. albidus). In these regions, it occurs as a harmless saprotroph on Fraxinus mandshurica and Fraxinus rhynchophylla, suggesting that those populations are native while the European ash dieback disease has a recent Eastern Asiatic origin. The distinctly higher genetic diversity found in Japanese Hy. fraxineus in contrast to European Hy. fraxineus supports this view. Genetic similarities between Japanese Hy. fraxineus and European Hy. albidus suggest that also Hy. albidus might be a descendant of Asian Hy. fraxineus, though having invaded Europe much earlier. However, consistent genetic deviation between European and Asian Hy. fraxineus at two nucleotide positions of the ITS region indicates that the European ash disease originates from a region different from the presently known areas in Eastern Asia. Our results underline the importance of detailed morphological studies

  1. 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

  2. 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)

  3. Preparation, transport and disposal of ash from coal-fired power plant Kosovo B in the form of dense hydromixture; Priprema, transport i deponovanje pepela termoelektrane Kosovo B u vidu guste hidromesavine

    Energy Technology Data Exchange (ETDEWEB)

    Drazovic, D.; Markovic, Z.; Stjepanovic, P.; Todorovtc, D. [Rudarski Institute, Beograd (Yugoslavia)

    1999-07-01

    The transportation of ash and slag from coal-fired power plants is mainly hydraulic. Until the eighties the most frequently applied technology was the transportation of ash and slag in the form of diluted hydromixture (concentration of solids below 10%). This method of ash and slag transportation became a rule in Yugoslavia's coal-fired power plants. It was not until 1988 that the transportation of dense hydromixture was introduced in the coal-fired power plant Gacko. This technology was not applied on account of its transportation advantages, but due to specific ash features that determine the conditions of disposal. Namely, the density of hydromixture is important for the solidification of disposed material. Considering the chemical and mineralogical properties of ash the same system was applied in the coal-fired power plant Kosovo B. In this paper two technological lines were installed and put to use in actual industrial conditions, and the results obtained indicate that all the designed parameters have been confirmed in practice and that the application of this technology has proven to be profitable in many ways. 7 refs., 8 figs., 13 tabs.

  4. A scanning electron microscopy study of ash, char, deposits and fuels from straw combustion and co-combustion of coal and straw

    Energy Technology Data Exchange (ETDEWEB)

    Sund Soerensen, H.

    1998-07-01

    The SEM-study of samples from straw combustion and co-combustion of straw and coal have yielded a reference selection of representative images that will be useful for future comparison. The sample material encompassed potential fuels (wheat straw and grain), bottom ash, fly ash and deposits from straw combustion as well as fuels (coal and wheat straw), chars, bottom ash, fly ash and deposits from straw + coal co-combustion. Additionally, a variety of laboratory ashes were studied. SEM and CCSEM analysis of the samples have given a broad view of the inorganic components of straw and of the distribution of elements between individual ash particles and deposits. The CCSEM technique does, however, not detect dispersed inorganic elements in biomass, so to get a more complete visualization of the distribution of inorganic elements additional analyses must be performed, for example progressive leaching. In contrast, the CCSEM technique is efficient in characterizing the distribution of elements in ash particles and between ash fractions and deposits. The data for bottom ashes and fly ashes have indicated that binding of potassium to silicates occurs to a significant extent. The silicates can either be in the form of alumino-silicates or quartz (in co-combustion) or be present as straw-derived amorphous silica (in straw combustion). This process is important for two reasons. One is that potasium lowers the melting point of silica in the fly ash, potentially leading to troublesome deposits by particle impaction and sticking to heat transfer surfaces. The other is that the reaction between potassium and silica in the bottom ash binds part of the potassium meaning that it is not available for reaction with chlorine or sulphur to form KCl or K{sub 2}SO{sub 4}. Both phases are potentially troublesome because they can condense of surfaces to form a sticky layer onto which fly ash particles can adhere and by inducing corrosion beneath the deposit. It appears that in the studied

  5. 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

  6. Bottom production

    International Nuclear Information System (INIS)

    In the context of the LHC experiments, the physics of bottom flavoured hadrons enters in different contexts. It can be used for QCD tests, it affects the possibilities of B decays studies, and it is an important source of background for several processes of interest. The physics of b production at hadron colliders has a rather long story, dating back to its first observation in the UA1 experiment. Subsequently, b production has been studied at the Tevatron. Besides the transverse momentum spectrum of a single b, it has also become possible, in recent time, to study correlations in the production characteristics of the b and the b. At the LHC new opportunities will be offered by the high statistics and the high energy reach. One expects to be able to study the transverse momentum spectrum at higher transverse momenta, and also to exploit the large statistics to perform more accurate studies of correlations

  7. Bottom production

    Energy Technology Data Exchange (ETDEWEB)

    Baines, J.; Baranov, S.P.; Bartalini, P.; Bay, A.; Bouhova, E.; Cacciari, M.; Caner, A.; Coadou, Y.; Corti, G.; Damet, J.; Dell-Orso, R.; De Mello Neto, J.R.T.; Domenech, J.L.; Drollinger, V.; Eerola, P.; Ellis, N.; Epp, B.; Frixione, S.; Gadomski, S.; Gavrilenko, I.; Gennai, S.; George, S.; Ghete, V.M.; Guy, L.; Hasegawa, Y.; Iengo, P.; Jacholkowska, A.; Jones, R.; Kharchilava, A.; Kneringer, E.; Koppenburg, P.; Korsmo, H.; Kramer, M.; Labanca, N.; Lehto, M.; Maltoni, F.; Mangano, M.L.; Mele, S.; Nairz, A.M.; Nakada, T.; Nikitin, N.; Nisati, A.; Norrbin, E.; Palla, F.; Rizatdinova, F.; Robins, S.; Rousseau, D.; Sanchis-Lozano, M.A.; Shapiro, M.; Sherwood, P.; Smirnova, L.; Smizanska, M.; Starodumov, A.; Stepanov, N.; Vogt, R.

    2000-03-15

    In the context of the LHC experiments, the physics of bottom flavoured hadrons enters in different contexts. It can be used for QCD tests, it affects the possibilities of B decays studies, and it is an important source of background for several processes of interest. The physics of b production at hadron colliders has a rather long story, dating back to its first observation in the UA1 experiment. Subsequently, b production has been studied at the Tevatron. Besides the transverse momentum spectrum of a single b, it has also become possible, in recent time, to study correlations in the production characteristics of the b and the b. At the LHC new opportunities will be offered by the high statistics and the high energy reach. One expects to be able to study the transverse momentum spectrum at higher transverse momenta, and also to exploit the large statistics to perform more accurate studies of correlations.

  8. Tephra dispersal during the Campanian Ignimbrite (Italy) eruption: implications for ultra-distal ash transport during the large caldera-forming eruption

    Science.gov (United States)

    Smith, Victoria C.; Isaia, Roberto; Engwell, Sam L.; Albert, Paul. G.

    2016-06-01

    The Campanian Ignimbrite eruption dispersed ash over much of the central eastern Mediterranean Sea and eastern Europe. The eruption started with a Plinian phase that was followed by a series of pyroclastic density currents (PDCs) associated with the collapse of the Plinian column and the caldera. The glass compositions of the deposits span a wide geochemical range, but the Plinian fallout and PDCs associated with column collapse, the Lower Pumice Flow, only erupted the most evolved compositions. The later PDCs, the Breccia Museo and Upper Pumice Flow, erupted during and after caldera collapse, tap a less evolved component, and intermediate compositions that represent mixing between the end-members. The range of glass compositions in the Campanian Ignimbrite deposits from sites across the central and eastern Mediterranean Sea allow us to trace the dispersal of the different phases of this caldera-forming eruption. We map the fallout from the Plinian column and the plumes of fine material associated with the PDCs (co-PDCs) across the entire dispersal area. This cannot be done using the usual grain-size methods as deposits in these distal regions do not retain characteristics that allow attribution to either the Plinian or co-PDC phases. The glass compositions of the tephra at ultra-distal sites (>1500 km from the vent) match those of the uppermost PDC units, suggesting that most of the ultra-distal dispersal was associated with the late co-PDC plume that was generated during caldera collapse.

  9. 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

  10. Development and validation of HPLC-ICP-MS method for the determination inorganic Cr, As and Sb speciation forms and its application for Pławniowice reservoir (Poland) water and bottom sediments variability study.

    Science.gov (United States)

    Jabłońska-Czapla, Magdalena; Szopa, Sebastian; Grygoyć, Katarzyna; Łyko, Aleksandra; Michalski, Rajmund

    2014-03-01

    The optimization of methodology for determination and extraction of inorganic ionic As(III)/As(V), Cr(III)/Cr(VI) and Sb(III)/Sb(V) forms in water and easily-leached fractions of bottom sediments by HPLC-ICP-MS were studied. In paper total concentration of As, Cr, Sb, pH and redox potential were determined. Ions were successfully separated on Dionex IonPac AS7: As(III), As(V), Sb(III), Sb(V) and Dionex IonPac AG7: Cr(III), Cr(VI) with LOD 0.18 μg/L, 0.22 μg/L, 0.009 μg/L, 0.012 μg/L 0.11 μg/L, 0.17 μg/L, respectively. Water and bottom sediments samples were collected monthly from Pławniowice Reservoir, in three-point transects between March and December 2012. In the bottom water predominated As(III) and Cr(III) forms and the highest content of Cr(III) was in the water flowing into the Pławniowice Reservoir. Concentration of Cr(VI) increased in the bottom water in the spring and summer (April-July), while decreasing of the Cr(III) content was associated with the release of Cr(VI) from sediment into the water. Studies have shown that antimony accumulates in reservoir sediments and its reduced form was predominated except May and October-November period when high concentrations of Sb(V) was present. In contrast As(V) was the predominant arsenic form in bottom sediments. PMID:24468399

  11. 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)  

  12. 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.

  13. Evaluating the Effects of the Kingston Fly Ash Release on Fish Reproduction: Spring 2009 - 2010 Studies

    Energy Technology Data Exchange (ETDEWEB)

    Greeley Jr, Mark Stephen [ORNL; Adams, Marshall [ORNL; McCracken, Kitty [ORNL

    2012-05-01

    On December 22, 2008, a dike containing fly ash and bottom ash at the Tennessee Valley Authority's (TVA) Kingston Fossil Plant in East Tennessee failed and released a large quantity of ash into the adjacent Emory River. Ash deposits from the spill extended 4 miles upstream of the facility to Emory River mile 6 and downstream to Tennessee River mile 564 ({approx}8.5 miles downstream of the confluence of the Emory River with the Clinch River, and {approx}4 miles downstream of the confluence of the Clinch River with the Tennessee River). A byproduct of coal combustion, fly ash contains a variety of metals and other elements which, at sufficient concentrations and in specific forms, can be harmful to biological systems. The ecological effects of fly ash contamination on exposed fish populations depend on the magnitude and duration of exposure, with the most significant risk considered to come from elevated levels of certain metals in the ash, particularly selenium, on fish reproduction and fish early life stages (Lemly 1993; Besser and others 1996). The ovaries of adult female fish in a lake contaminated by coal ash were reported to have an increased frequency of atretic oocytes (dead or damaged immature eggs) and reductions in the overall numbers of developing oocytes (Sorensen 1988) associated with elevated body burdens of selenium. Larval fish exposed to selenium through maternal transfer of contaminants to developing eggs in either contaminated bodies of water (Lemly 1999) or in experimental laboratory exposures (Woock and others 1987, Jezierska and others 2009) have significantly increased incidences of developmental abnormalities. Contact of fertilized eggs and developing embryos to ash in water and sediments may also pose an additional risk to the early life stages of exposed fish populations through direct uptake of metals and other ash constituents (Jezierska and others 2009). The establishment and maintenance of fish populations is intimately associated

  14. Speciation of Zinc in ash investigated by X-ray absorption spectroscopy; Zinks foerekomstformer i aska studerade med en roentgenabsorptionsspektrometrisk metod

    Energy Technology Data Exchange (ETDEWEB)

    Steenari, Britt-Marie; Noren, Katarina

    2008-06-15

    neighbour, but also about the next scattering shell of atoms surrounding the central zinc atom. The EXAFS data and modelling results showed that the most common zinc species in wood fuel ashes from FBC boilers are silicate, aluminate and to a lesser extent hydroxide. It cannot be ruled out that zinc can be bound as ZnO but this form is not dominant. This is the case for both bottom ashes and fly ashes. In one of the FBC boilers (BFB-bio), elementary sulphur is added in order to abate corrosion problems. Both bottom ash and fly ash from that combustor showed indications of the presence of ZnS or ZnCl{sub 2}. It is difficult to distinguish between Zn-S and Zn-Cl distances be EXAFS, but since zinc chloride is not likely to be stable in a combustor bed the conclusion was drawn that some zinc had been bound as sulphide in the bottom ash. The filter ash, however, might contain both sulphide and chloride in small amounts. Kaolin was used as an anti-sintering additive during a test period in the wood fuelled CFB included in this work. The general results from this test period has been published elsewhere but it is interesting for this investigation to note that the kaolin absorbed potassium that otherwise should have formed gaseous KCl and thus, left some more HCl in the flue gas free to react with other metal species in the burning fuel. In addition, it was noted that the kaolin was concentrated in the fly ash as was potassium and zinc. The EXAFS data for this fly ash showed the presence of ZnCl{sub 2} and/or ZnS. Due to the increased presence of HCl in the flue gas zinc chloride is most likely compound. However, it was only present in a small amount and the main part of the Zn was found as silicate. In the fly ash from normal operation of the boiler no zinc chloride was found. Wood ash that had been moistened and aged was shown to contain zinc in silicate, hydroxide and/or aluminate forms. In one sample of an ash the had been aged outdoors for only 0.5 years indication of minor

  15. 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

  16. 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

  17. Chemical fractionation method for characterization of biomass-based bottom and fly ash fractions from large-sized power plant of an integrated pulp and paper mill complex%化学分离法分析大型纸浆发电厂废渣中生物质底灰和飞灰成分

    Institute of Scientific and Technical Information of China (English)

    Risto PÖYKIÖ; Hannu NURMESNIEMI; Olli DAHL; Mikko MÄKELÄ

    2014-01-01

    The aim of this study was to extract the biomass-based bottom and fly ash fractions by a three-stage fractionation method for water-soluble (H2O), ammonium-acetate (CH3COONH4) and hydrochloric acid (HCl) fractions in order to access the leaching behaviour of these residues. Except for Mo, S, Na and elements whose concentrations were lower than the detection limits, the extractable element concentrations in both ash fractions followed the order H2O

  18. Is coal ash and slag any useful or unloaded wastes?

    International Nuclear Information System (INIS)

    It is well known that all types of coal, like most materials found in nature, contain trace quantities of the naturally occurring primordial radionuclides (uranium and thorium families and potassium-40). Therefore, the combustion of coal results in partitioning of radionuclides included in the non-combustible mineral matter, between the bottom ash and fly ash, and in the release into the environment of large amounts of coal ash. Emissions from thermal power stations in gaseous and particulate form contain radioisotopes arising from the uranium and thorium series as well as from 40K. They are discharged into the environment causing changes in the natural radiation background and radiation exposures to the population. The continued releases of these materials to environment may result in a buildup in the air, water and soil of the radionuclides, particularly radium-226. There will be an increase of the basic radiation rate in the neighborhood area of these plants and consequently relatively higher exposure of the local population to radiation. Coal burning is, therefore, one of the sources of technologically enhanced exposure to humans from natural radionuclides (1,2,3,4,5,6). Coal based thermal power plants constitute about 35% of quantum of energy supply in Romania. In view of the importance of coal for energy supply in Romania, we were interested in knowing possible uses of the resulting wastes and minimize the following harmful consequences of coal burning

  19. Low-level radiation in coals utilized and ashes produced at New York State electric utilities

    International Nuclear Information System (INIS)

    Eight coal-fired power plants in New York State were sampled for coal, fly ash and bottom ash. Samples were analyzed for uranium 238, uranium 235, uranium 234, thorium 232, thorium 230, radium 226, lead 210, polonium 210, radon 222. The leachate of six fly ash samples was analyzed for all of the above except radon 222. Some data on fly ash analysis are included

  20. Agglomeration in Stripper Ash Coolers and Its Possible Remedial Solutions: a Case Study

    Science.gov (United States)

    Singh, Ravi Inder

    2016-04-01

    The bottom ash of circulating fluidized bed (CFB) boiler contains large amounts of physical heat. When low quality coals are used in these types of boilers, the ash content is normally more than 40 % and the physical heat loss is approximately 3 % if the bottom ash is discharged without cooling. Bottom ash cooler (BAC) is often used to treat the high temperature bottom ash to reclaim heat, and to facilitate the easily handling and transportation of ash. The CFB boiler at BLA Power, Newari, MP (India) is facing problems of clinker formation in strip ash coolers of plant since the installation of unit. These clinkers are basically agglomerates, which leads to defluidization of stripper ash cooler (BAC) units. There are two strip ash coolers in unit. Each strip ash cooler is capable of working independently. The proper functioning of both strip coolers is very important as it is going to increase the combustion efficiency of boiler by stripping of fine unburnt coal particles from ash, which are injected into the furnace. In this paper causes, characterization of agglomerates, thermo gravimetric analysis of fuel used, particular size distribution of coal and sand and possible remedial solution to overcome these agglomerates in strip ash coolers has also been presented. High temperature in compact separators, non uniform supply of coal and not removing small agglomerates from stripper ash cooler are among main causes of agglomeration in stripper ash cooler. Control of compact separator temperature, replacing 10-12 % of bed material and cleaning stripper ash cooler periodically will decrease agglomeration in stripper ash cooler of unit.

  1. 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.)

  2. Dissolution of hardened wood ash in forest soils. Studies in a column experiment; Haerdade vedaskors upploesning i skogsjord. En studie i kolonnfoersoek. Ramprogram Askaaterfoering

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, Jan [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Soil Sciences

    1996-12-31

    Dissolution of hardened and crushed ashes was studied in a column experiment during leaching with artificial rain water corresponding to 5 year-precipitations. The ashes studied were a CFB ash from Perstorp and a bottom ash from Ljungby that were added in amounts corresponding to 4 tonnes per hectare. Assuming that the studied ashes are representative and that the results can be transferred to field conditions, the most important conclusions that can be drawn are summarized in the following way: Hardened and crushed ashes are broken down relatively slowly, which particularly applies to the coarse fraction. The fine fraction of the Perstorp ashes has a good liming effect at the same time as the risk for large pH-increases appears to be small. As regards the macro-nutrients Ca and K (not the Ljungby ashes), the amounts released are probably sufficient from a forest vitalization viewpoint. As regards Mg and P, this is less certain. The heavy metals appear to be released relatively slowly and most of them are bound in non-exchangeable form in the mor layer. The exception is Cd that tends to be absorbed in the mor layer to a minor extent but which, on the other hand, is not released from the ashes in any greater amounts. The greatest risk for increased concentrations of soluble heavy metals appears to be the mobilization of part of the mor layer`s reserve as a result of the salt effect of the ashes. However, this is a temporary effect. 17 refs, 18 figs, 6 tabs Figs and tabs with text in English

  3. Use of Biomass Ash as a stabilization agent for expansive marly soils (SE Spain)

    Science.gov (United States)

    Ureña, C.; Azañón, J. M.; Caro, J. M.; Irigaray, C.; Corpas, F.; Ramirez, A.; Rivas, F.; Salazar, L. M.; Mochón, I.

    2012-04-01

    In recent years, several biomass power plants have been installed in Southeastern Spain to reuse olive oil industry residues. This energy production tries to reduce the high costs associated with fossil fuels, but without entering into direct competition to traditional food crops. The waste management in these biomass energy plants is still an issue since there are non-flammable materials which remains after incineration in the form of ashes. In Southeastern Spain there is also a great amount of clayey and marly soils whose volume is very sensitive to changes in climate conditions, making them unsuitable for civil engineering. We propose the use of biomass ash (both fly ash and bottom ash) as a stabilization agent for expansive soils in order to improve the efficiency of construction processes by using locally available materials. In this work biomass ashes from a biomass power plant in Southeastern Spain have been used to stabilize 6 samples of local marly soil. Those 6 samples of expansive soil were mixed with different dosages of biomass ash (2%, 4% and 7%) to create 18 specimens of treated soil, which were submitted to Proctor, Atterberg Limits, pH and Free Swell Index tests, following Spanish Standards UNE by AENOR. X-Ray Diffraction (XRD) tests by powder method were also carried out, using a diffractometer Philips X'Pert-MPD. The results obtained for the original untreated marly soil were: PI = 34.6; Free Swell = 12.5; pH = 8. By adding biomass ash the value of the plasticity index (PI) became slightly lower although it was not low enough as to obtain a non-plastic soil (PI under 25). However, there were dramatical decreases of free swell index (FSI) after the stabilization treatment: FSI durable effect may be related to cation exchange from Na+ to smaller cations or even the formation of mixed-layered clay minerals. A further research must be conducted to determine the pozzolanic properties of biomass ash (i.e., its suitability for concrete composites), the

  4. Bottomed analog of Z+(4433)

    International Nuclear Information System (INIS)

    The newly observed Z+(4433) resonance by BELLE is believed to be a tetraquark bound state made up of (cu)(cd). We propose the bottomed analog of this bound state, namely, by replacing one of the charm quarks by a bottom quark, thus forming Zbc0,±,±±. One of the Zbc is doubly charged. The predicted mass of Zbc is around 7.6 GeV. This doubly charged bound state can be detected by its decay into Bc±π±. Similarly, we can also replace both charm quark and antiquark of the Z+(4433) by bottom quark and antiquark, respectively, thus forming Zbb the bottomonium analog of Z+(4433). The predicted mass of Zbb is about 10.7 GeV

  5. Biological responses of agricultural soils to fly-ash amendment.

    Science.gov (United States)

    Singh, Rajeev Pratap; Sharma, Bhavisha; Sarkar, Abhijit; Sengupta, Chandan; Singh, Pooja; Ibrahim, Mahamad Hakimi

    2014-01-01

    The volume of solid waste produced in the world is increasing annually, and disposing of such wastes is a growing problem. Fly ash (FA) is a form of solid waste that is derived from the combustion of coal. Research has shown that fly ash may be disposed of by using it to amend agricultural soils. This review addresses the feasibility of amending agricultural field soils with fly ash for the purpose of improvings oil health and enhancing the production of agricultural crops. The current annual production of major coal combustion residues (CCRs) is estimated to be -600 million worldwide, of which about 500 million t (70-80%) is FA (Ahmaruzzaman 2010). More than 112 million t of FA is generated annually in India alone, and projections show that the production (including both FA and bottom ash) may exceed 170 million t per annum by 2015 (Pandey et al. 2009; Pandey and Singh 20 I 0). Managing this industrial by-product is a big challenge, because more is produced each year, and disposal poses a growing environmental problem.Studies on FA clearly shows that its application as an amendment to agricultural soils can significantly improve soil quality, and produce higher soil fertility. What FA application method is best and what level of application is appropriate for any one soil depends on the following factors: type of soil treated, crop grown, the prevailing agro climatic condition and the character of the FA used. Although utilizing FA in agricultural soils may help address solid waste disposal problems and may enhance agricultural production, its use has potential adverse effects also. In particular, using it in agriculture may enhance amounts of radionuclides and heavy metals that reach soils, and may therefore increase organism exposures in some instances. PMID:24984834

  6. 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

  7. 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

  8. 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.

  9. 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

  10. 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

    supply managers include: monitoring turbidity levels in raw water intakes, and if necessary increasing chlorination to compensate for higher turbidity; managing water demand; and communicating monitoring results with the public to allay fears of contamination. Ash can cause major damage to wastewater disposal systems. Ash deposited onto impervious surfaces such as roads and car parks is very easily washed into storm drains, where it can form intractable masses and lead to long-term flooding problems. It can also enter wastewater treatment plants (WWTPs), both through sewer lines and by direct fallout. Damage to modern WWTPs can run into millions of dollars. Ash falls reduce visibility creating hazards for ground transportation. Dry ash is also readily remobilised by vehicle traffic and wind, and dry and wet ash deposits will reduce traction on paved surfaces, including airport runways. Ash cleanup from road and airports is commonly necessary, but the large volumes make it logistically challenging. Vehicles are vulnerable to ash; it will clog filters and brake systems and abrade moving parts within engines. Lastly, modern telecommunications networks appear to be relatively resilient to volcanic ash fall. Signal attenuation and interference during ash falls has not been reported in eruptions over the past 20 years, with the exception of interference from ash plume-generated lightning. However, some telecommunications equipment is vulnerable to airborne ash, in particular heating, ventilation and air-conditioning (HVAC) systems which may become blocked from ash ingestion leading to overheating. This summary of volcanic ash impacts on critical infrastructure provides insight into the relative vulnerability of infrastructure under a range of different ashfall scenarios. Identifying and quantifying these impacts is an essential step in building resilience within these critical systems. We have attempted to consider interdependencies between sectors in a holistic way using

  11. 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

  12. Optimal Recycling Combination of Ash in South-East Finland

    OpenAIRE

    Deviatkin, Ivan; Havukainen, Jouni; Horttanainen, Mika

    2016-01-01

    The present world energy production is heavily relying on the combustion of solid fuels like coals, peat, biomass, municipal solid waste, whereas the share of renewable fuels is anticipated to increase in the future to mitigate climate change. In Finland, peat and wood are widely used for energy production. In any case, the combustion of solid fuels results in generation of several types of thermal conversion residues, such as bottom ash, fly ash, and boiler slag. The predominant residue type...

  13. 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).

  14. Characterization of black carbon and organic contaminants in wood ash from different feedstocks and types of furnaces

    Science.gov (United States)

    Merino, Agustin; Rey-Salgueiro, Ledicia; Omil, Beatriz; Martinez-Carballo, Elena; Simal-Gandara, Jesus

    2015-04-01

    Due to their important concentration of nutrient and charcoal, wood ash from biomass power plants (WA) can be used as a fertilizer and organic amendment in intensively managed soils. Unlike biochar produced in under anoxic conditions, the nature of the organic compounds present in wood ash has been scarcely studied. Due to the incomplete combustion, wood ash may contain a wide range of organic compounds, from charred to highly condensed refractory biomass, which determines the possibilities of WA as an organic amendment. In addition, the possible environmental risk of this practice must be assessed by determining the content of water-soluble and insoluble organic contaminants. due to the incomplete combustion of organic matter, organic pollutants, such as Polycyclic Aromatic Hydrocarbons (PAHs), can be formed and can remain in the combustion residue. Also, the four alkyl benzene volatile organic compounds (benzene, toluene, ethylbenzene, and the ortho, para, and meta xylenes) can be formed, depending on certain conditions during combustion. For this study 15 biomass power stations in Spain were selected. In all of them the feedstock is pine or eucalyptus branches and bark. Nine of them were bottom wood ash generated from wood fires furnaces, obtained from grate-fired or water-tube boilers. Whereas four of them were fly ash, obtained in cyclone separators. The samples were collected following a common procedure to ensure the representiveness of the sampling. Bottom ash samples were fraccionated in three fractions: 5mm. Each fraction was characterized for organic matter and BTEX, styrene and total petroleum hydrocarbons Polycyclic Aromatic Hydrocarbons. For each analyzes, three replicates were analyzed per sample. Mixes wood ash shows higher amounts of charred material than fly ash. The 13 C CPMAS NMR, DSC/TG and FTIR analysis showed the loss of carbohydrates and aliphatic constituents and revealed the formation of aromatic compounds. The atomic H/C ratios, NMR

  15. Influences of chemical activators on incinerator bottom ash.

    Science.gov (United States)

    Qiao, X C; Cheeseman, C R; Poon, C S

    2009-02-01

    This research has applied different chemical activators to mechanically and thermally treated fine fraction (material. IBA has been milled and thermally treated at 800 degrees C (TIBA). The TIBA produced was blended with Ca(OH)(2) and evaluated for setting time, reactivity and compressive strength after the addition of 0.0565 mole of Na(2)SO(4), K(2)SO(4), Na(2)CO(3), K(2)CO(3), NaOH, KOH and CaCl(2) into 100g of binder (TIBA+Ca(OH)(2)). The microstructures of activated IBA and hydrated samples have been characterized by X-ray diffraction (XRD) and thermogravimetry (TG) analysis. Thermal treatment is found to produce gehlenite (Ca(2)Al(2)SiO(7)), wollastonite (CaSiO(3)) and mayenite (Ca(12)Al(14)O(33)) phases. The thermally treated IBA samples are significantly more reactive than the milled IBA. The addition of Na(2)CO(3) can increase the compressive strength and calcium hydroxide consumption at 28-day curing ages. However, the addition of Na(2)SO(4), K(2)SO(4), K(2)CO(3), NaOH and KOH reduces the strength and hydration reaction. Moreover, these chemicals produce more porous samples due to increased generation of hydrogen gas. The addition of CaCl(2) has a negative effect on the hydration of TIBA samples. Calcium aluminium oxide carbonate sulphide hydrate (Ca(4)Al(2)O(6)(CO(3))(0.67)(SO(3))(0.33)(H(2)O)(11)) is the main hydration product in the samples with activated IBA, except for the sample containing CaCl(2). PMID:18718749

  16. Influences of chemical activators on incinerator bottom ash

    International Nuclear Information System (INIS)

    This research has applied different chemical activators to mechanically and thermally treated fine fraction (2 and evaluated for setting time, reactivity and compressive strength after the addition of 0.0565 mole of Na2SO4, K2SO4, Na2CO3, K2CO3, NaOH, KOH and CaCl2 into 100 g of binder (TIBA+Ca(OH)2). The microstructures of activated IBA and hydrated samples have been characterized by X-ray diffraction (XRD) and thermogravimetry (TG) analysis. Thermal treatment is found to produce gehlenite (Ca2Al2SiO7), wollastonite (CaSiO3) and mayenite (Ca12Al14O33) phases. The thermally treated IBA samples are significantly more reactive than the milled IBA. The addition of Na2CO3 can increase the compressive strength and calcium hydroxide consumption at 28-day curing ages. However, the addition of Na2SO4, K2SO4, K2CO3, NaOH and KOH reduces the strength and hydration reaction. Moreover, these chemicals produce more porous samples due to increased generation of hydrogen gas. The addition of CaCl2 has a negative effect on the hydration of TIBA samples. Calcium aluminium oxide carbonate sulphide hydrate (Ca4Al2O6(CO3)0.67(SO3)0.33(H2O)11) is the main hydration product in the samples with activated IBA, except for the sample containing CaCl2

  17. Use of sugar-cane bagasse ash to produce glass-ceramic material in the system Ca O-SiO2-Na2O

    International Nuclear Information System (INIS)

    A bottom ash was used as raw material to obtain glass which was crystallized to form glass-ceramic material. The characterization of the ash shows that it consists mainly of crystalline materials, predominantly quartz, with oxides of iron, potassium and aluminum as minor elements. The glass was obtained from the mixing of ash with calcium and sodium carbonates. The glass and the glass-ceramic were examined using differential thermal analysis (DTA), X-ray fluorescence (XRF), X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD and DTA data show that Wollastonita is the only crystalline phase present in the material crystallized at 1050 deg C. Part of the glass was synthesized at this temperature for one hour, resulting in a green/brown hard material glass-ceramic. The images of SEM show morphology of spherilithic growth indicating volumetric crystallization mechanism. (author)

  18. EVALUATING THE EFFECTS OF FLY ASH EXPOSURE ON FISH EARLY LIFE STAGES: FATHEAD MINNOW EMBRYO-LARVAL TESTS

    Energy Technology Data Exchange (ETDEWEB)

    Greeley Jr, Mark Stephen [ORNL; Elmore, Logan R [ORNL; McCracken, Kitty [ORNL

    2012-05-01

    On December 22, 2008, a dike containing fly ash and bottom ash in an 84-acre complex of the Tennessee Valley Authority's (TVA) Kingston Steam Plant in East Tennessee failed and released a large quantity of ash into the adjacent Emory River. Ash deposits extended as far as 4 miles upstream (Emory River mile 6) of the Plant, and some ash was carried as far downstream as Tennessee River mile 564 ({approx}4 miles downstream of the Tennessee River confluence with the Clinch River). A byproduct of coal burning power plants, fly ash contains a variety of metals and other elements which, at sufficient concentrations and in specific forms, can be toxic to biological systems. The effects of fly ash contamination on exposed fish populations depend on the magnitude and duration of exposure, with the most significant risk considered to be the effects of specific ash constituents, especially selenium, on fish early life stages. Uptake by adult female fish of fly ash constituents through the food chain and subsequent maternal transfer of contaminants to the developing eggs is thought to be the primary route of selenium exposure to larval fish (Woock and others 1987, Coyle and others 1993, Lemly 1999, Moscatello and others 2006), but direct contact of the fertilized eggs and developing embryos to ash constituents in river water and sediments is also a potential risk factor (Woock and others 1987, Coyle and others 1993, Jezierska and others 2009). To address the risk of fly ash from the Kingston spill to the reproductive health of downstream fish populations, ORNL has undertaken a series of studies in collaboration with TVA including: (1) a field study of the bioaccumulation of fly ash constituents in fish ovaries and the reproductive condition of sentinel fish species in reaches of the Emory and Clinch Rivers affected by the fly ash spill; (2) laboratory tests of the potential toxicity of fly ash from the spill area on fish embryonic and larval development (reported in the

  19. 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

  20. Ash Deposition Trials at Three Power Stations in Denmark

    DEFF Research Database (Denmark)

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

    1998-01-01

    Six full-scale trials were conducted at three power stations in Denmark: Ensted, Funen, and Vendsyssel power stations. During these trials, pulverized coal, bottom ash, fly ash, and deposits from cooled probes were sampled and analyzed with various techniques. On the basis of SEM analyses, the...... deposits can be grouped into five textural types, which all possess distinct textural and chemical characteristics. Likewise, the deposition mechanisms for these five types are characteristic and they may be used for constructing a model for the buildup and maturation of an ash deposit. The deposits...... collected on the probes were thin (maximum 2 mm after 9 h) and the influence of operational parameters and probe temperatures on the magnitude of the deposits were minor. The probe temperatures had no influence on the composition of the ash deposits for coals with low ash deposition propensities, whereas...

  1. 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)

  2. Distribution and Solubility of Radionuclides and Neutron Absorbers in Waste Forms for Disposition of Plutonium Ash and Scraps, Excess Plutonium, and Miscellaneous Spent Nuclear Fuels

    International Nuclear Information System (INIS)

    The initial goal of this project was to investigate the solubility of radionuclides in glass and other potential waste forms for the purpose of increasing the waste loading in glass and ceramic waste forms. About one year into the project, the project decided to focus on two potential waste forms - glass at PNNL and initiate ceramics at the Australian Nuclear Science and Technology Organisation (ANSTO)

  3. Variability of total and mobile element contents in ash derived from biomass combustion

    Czech Academy of Sciences Publication Activity Database

    Száková, J.; Ochecová, P.; Hanzlíček, Tomáš; Perná, Ivana; Tlustoš, P.

    2013-01-01

    Roč. 67, č. 11 (2013), s. 1376-1385. ISSN 0366-6352 R&D Projects: GA MZe QI102A207 Institutional support: RVO:67985891 Keywords : biomass combustion * fly ash * bottom ash * element contents Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 1.193, year: 2013

  4. Properties of municipal solid waste incineration ashes with respect to their separation temperature

    Czech Academy of Sciences Publication Activity Database

    Keppert, M.; Pavlík, Z.; Tydlitát, V.; Volfová, P.; Švarcová, Silvie; Šyc, Michal; Černý, R.

    2012-01-01

    Roč. 30, č. 10 (2012), s. 1041-1048. ISSN 0734-242X Institutional support: RVO:61388980 ; RVO:67985858 Keywords : bottom ash * fly ash * municipal solid waste incinerator * pozzolanic activity * hydration heat * separation temperature * building industry Subject RIV: CA - Inorganic Chemistry Impact factor: 1.047, year: 2012

  5. 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.

  6. 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.

  7. 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

  8. Partitioning behavior of trace elements during pilot-scale fluidized bed combustion of high ash content lignite

    International Nuclear Information System (INIS)

    This study describes the partitioning of 20 trace elements (As, B, Ba, Cd, Co, Cr, Cu, Hg, Li, Mn, Mo, Ni, P, Pb, Sb, Se, Sn, Tl, V, Zn) and eight major and minor elements (Al, Ca, Fe, K, Mg, Na, Si, Ti) during the combustion of high ash content lignite. The experiments were carried out in the 0.3 MWt Middle East Technical University (METU) atmospheric bubbling fluidized bed combustor (ABFBC) test rig with and without limestone addition. Inert bed material utilized in the experiments was bed ash obtained previously from the combustion of the same lignite without limestone addition in the same test rig. Concentrations of trace elements in coal, limestone, bottom ash, cyclone ash and filter ash were determined by inductively coupled plasma optical emission spectroscopy (ICP-OES). Partitioning of major and minor elements are influenced by the ash split between the bottom ash and fly ash and that the major proportion of most of the trace elements (As, Ba, Cr, Hg, Li, Mo, Ni, Sn, V, Zn) are recovered in fly ash. Limestone addition shifts the partitioning of Ba, Cr, Mo, Ni, Sn, V, Zn from bottom ash to fly ash

  9. EFFECT ON COMPRESSIVE STRENGTH OF CONCRETE WITH PARTIAL REPLACEMENT OF CEMENT BY MUNICIPAL SOLID WASTE INCINERATION ASH

    OpenAIRE

    V. Alivelu Mangamma

    2016-01-01

    The municipal solid waste incineration ash reduces are worldwide studied topic over the last decades, so that utilize the municipal solid waste is the one of the possibilities is to use MSWI in concrete production as it is done the bottom ash features the most convenient composition in concrete and it is a available in highest amounts among the MSWI ashes the bottom ash was used as partial replacement of cement of cement in concrete strength has to find ,if the prepared concrete will get suff...

  10. A Middle Pennsylvanian (Bolsovian) peat-forming forest preserved in situ in volcanic ash of the Whetstone Horizon in the Radnice Basin, Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Opluštil, S.; Pšenička, J.; Libertín, M.; Bashforth, A. R.; Šimůnek, Z.; Drábková, J.; Dašková, Jiřina

    2009-01-01

    Roč. 155, 3-4 (2009), s. 234-274. ISSN 0034-6667 R&D Projects: GA ČR GA205/05/0105 Institutional research plan: CEZ:AV0Z30130516 Keywords : Pennsylvanian * tuff * in situ * plant taphonomy * palaeoecology * peat-forming mires Subject RIV: DB - Geology ; Mineralogy Impact factor: 2.145, year: 2009

  11. Bottom dwelling animals: Benthos

    Digital Repository Service at National Institute of Oceanography (India)

    Ingole, B.S.

    . At the bottom/sediment dwelling animal communities are collectively termed as 'BENTHOS'. This extremely valuable component of the marine environment consumes the sediment organic matter from the overlying water column and effectively converts into benthic...

  12. Winter Bottom Trawl Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Winter Bottom Trawl Survey was initiated in 1992 and covered offshore areas from the Mid-Atlantic to Georges Bank. Inshore strata were...

  13. Spring Bottom Trawl Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Spring Bottom Trawl Survey was initiated in 1968 and covered an area from Cape Hatteras, NC, to Nova Scotia, Canada, at depths >27m....

  14. Summer Bottom Trawl Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sampling the coastal waters of the Gulf of Maine using the Northeast Fishery Science Center standardized bottom trawl has been problematic due to large areas of...

  15. 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

  16. 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

  17. Full-scale ash deposition measurements at Avedøre Power Plant unit 2 during suspension-firing of wood with and without coal ash addition

    DEFF Research Database (Denmark)

    Wu, Hao; Shafique Bashir, Muhammad; Jensen, Peter Arendt

    The formation of deposits during suspension-firing of wood at Avedøre Power Plant unit 2 (AVV2) was studied by using an advanced deposit probe system. The tests were conducted both with and without coal ash addition, and at two different locations with flue gas temperatures of 1250-1300 oC and 750...... along with the fly ash and bottom ash from the plant were characterized extensively by SEM-EDS, ICP-OES/IC and XRD. Based on the results from the present work, the deposit formation and shedding mechanisms under different operational conditions were proposed and discussed. The influence of coal ash...... addition on deposit formation during wood suspension-firing at AVV2 was evaluated. It was revealed that the addition of coal fly ash could significantly influence the ash deposition/shedding behaviors and the deposit properties. The effect was evident at both measurement locations. At the location...

  18. Radiological Considerations in the Production of Lightweight Concrete Based on Coal Ashes

    International Nuclear Information System (INIS)

    The common disadvantage of using high volumes of coal ashes (both bottom ash and fly ash) in lightweight concrete production is the presence in the ashes of trace amounts of heavy metals and natural radionuclides such as 226Ra, 232Th and 40K. Therefore, coal ashes are classified in many cases as a material with enhanced radioactivity. Accordingly, the use of coal ashes in lightweight concrete must comply with requirements of international recommendations and national legislations. Over the past decade, a series of studies were performed at the Ariel University Center of Samaria (Ariel, Israel) in search for optimum solutions for the use of coal ashes (both fly and bottom ashes) in the lightweight concrete technology. These studies included investigations of scientific and engineering issues related to the radiological and engineering aspects of the utilization of coal ashes in the building industry, as described in this paper. Special attention was paid to a problem of producing ecologically-friendly concrete based on coal ashes. Our product contributes significantly to the advancement of material recirculation by using in addition to fly ash, also bottom ash. This significant by product of coal combustion is used at present predominantly for construction beddings, structural fills. Utilization of fly ash for concrete production contributes to the reduction of the potential damage to the environment that can be caused by the accumulation of coal ashes in piles and ponds near power stations. Bonding the ash particles (in safe quantities) with the cement in concrete articles and structures reduces the potential exposure of humans to internal radiation by avoiding the penetration of fine ash particles to human internal organs. In order to lower the radioactivity of concrete resulting from the use of coal ashes, we added to the concrete mixture calculated amounts of unprocessed crushed sand (UCS). This material is denser and is very low in radioactivity. UCS is a by

  19. Monitoring of test roads with MSWI bottom ash in the sub-base. Measurements with falling weight deflectometer on test structures in Malmoe and Umeaa. Analyses of ground water and leachate along test structures in Umeaa; Uppfoeljning av slaggrusprovvaegar. Fallviktsmaetning paa provstraeckor paa Toerringevaegen i Malmoe och Daavamyran i Umeaa. Grundvatten- och lakvattenanalyser paa provstraeckor vid Daavamyran i Umeaa

    Energy Technology Data Exchange (ETDEWEB)

    Arm, Maria; Larsson, Lennart; Tiberg, Charlotta; Lind, Bo; Arvidslund, Ola

    2008-12-15

    A number of test roads and test areas with processed municipal solid waste incinerator bottom ash, here called MSWI gravel, have been built in Sweden during the last 10-15 years. The main purpose of the projects reported here was to take advantage of the existing test roads to increase the knowledge of the long-term strength and environmental impact of MSWI gravel, when it is used as a road material. Two test roads with MSWI gravel in the sub-base were monitored through falling weight deflectometer (FWD) measurements and, for one of the roads, by means of sampling and analyses of groundwater and leachate within and along the road. The first road, constructed in 1998, is named Toerringevaegen and is situated outside Malmoe in the south of Sweden. The second road, Daava test road, was constructed in 2001 and is situated outside Umeaa in the north of Sweden. The roads were monitored regarding strength from 2004 to 2008 and Daava test road was also monitored regarding environmental impact from 2006 to 2008. For both roads, comparison was made over time and between the test sections with MSWI gravel and reference sections with crushed rock. Comparison was also made with results from previous studies on these test roads, resulting in a uniquely long monitoring period. The results from Toerringevaegen show that the road section with MSWI gravel in the sub-base retains its strength after several years. The three measurements performed at the Daava road revealed an initially decreasing strength and then a stabilisation. As in previous studies, the strength of the MSWI gravel was found to be about 70% of that of the crushed rock, which has to be taken into account in the design phase. It was concluded that regarding the strength properties MSWI gravel is suitable as sub-base material if the road is properly designed. It can also be used as a filling material, in embankments and as a capping layer. This confirms the conclusions from previous studies. The results from the

  20. Charmed Bottom Baryon Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Zachary S; Detmold, William; Meinel, Stefan; Orginos, Kostas

    2014-11-01

    The spectrum of doubly and triply heavy baryons remains experimentally unexplored to a large extent. Although the detection of such heavy particle states may lie beyond the reach of exper- iments for some time, it is interesting compute this spectrum from QCD and compare results between lattice calculations and continuum theoretical models. Several lattice calculations ex- ist for both doubly and triply charmed as well as doubly and triply bottom baryons. Here, we present preliminary results from the first lattice calculation of doubly and triply heavy baryons including both charm and bottom quarks. We use domain wall fermions for 2+1 flavors (up down and strange) of sea and valence quarks, a relativistic heavy quark action for the charm quarks, and non-relativistic QCD for the heavier bottom quarks. We present preliminary results for the ground state spectrum.

  1. Total lead (Pb) concentration in oil shale ash samples based on correlation to isotope Pb-210 gamma-spectrometric measurements

    Energy Technology Data Exchange (ETDEWEB)

    Vaasma, T.; Kiisk, M.; Tkaczyk, A.H. [University of Tartu (Estonia); Bitjukova, L. [Tallinn University of Technology (Estonia)

    2014-07-01

    (PF) and circulating fluidized bed (CFB) firing technology. These samples were analyzed to determine macro and trace elements by the ICP-MS method. The same samples were also measured with a high-purity germanium detector (planar BSI GPD-50400) to determine the activity concentrations of natural radionuclides. The lead concentrations and Pb-210 activity concentrations were determined, and the correlation between the corresponding values was analyzed. Initial results demonstrate a strong positive linear relationship between these values, with the coefficient of determination (R{sup 2}) over 94. The correlation coefficient (Pearson's, 'r') had a value over 0.95. Both Pb and Pb-210 values had an increasing trend from the bottom ash towards electrostatic precipitator (ESP) ashes. The strong linear correlation between Pb concentrations and Pb-210 activity concentrations gives a credible indication that lead can be measured in ash samples using its radioactive isotope Pb-210. Especially in situations where there are higher concentrations of Pb, for example in the case of wastes from the metallurgic and energy industries, this method could be used to detect the lead concentration quickly and with no chemical processing of the sample. Document available in abstract form only. (authors)

  2. Total lead (Pb) concentration in oil shale ash samples based on correlation to isotope Pb-210 gamma-spectrometric measurements

    International Nuclear Information System (INIS)

    (PF) and circulating fluidized bed (CFB) firing technology. These samples were analyzed to determine macro and trace elements by the ICP-MS method. The same samples were also measured with a high-purity germanium detector (planar BSI GPD-50400) to determine the activity concentrations of natural radionuclides. The lead concentrations and Pb-210 activity concentrations were determined, and the correlation between the corresponding values was analyzed. Initial results demonstrate a strong positive linear relationship between these values, with the coefficient of determination (R2) over 94. The correlation coefficient (Pearson's, 'r') had a value over 0.95. Both Pb and Pb-210 values had an increasing trend from the bottom ash towards electrostatic precipitator (ESP) ashes. The strong linear correlation between Pb concentrations and Pb-210 activity concentrations gives a credible indication that lead can be measured in ash samples using its radioactive isotope Pb-210. Especially in situations where there are higher concentrations of Pb, for example in the case of wastes from the metallurgic and energy industries, this method could be used to detect the lead concentration quickly and with no chemical processing of the sample. Document available in abstract form only. (authors)

  3. Water retention properties of ashes; Vattenretentionsegenskaper hos aska

    Energy Technology Data Exchange (ETDEWEB)

    Hemstroem, Kristian; Ezziyani, Samir; Bendz, David

    2009-05-15

    The water holding properties of a material can be described with a water retention curve (also called pF curve or characteristic curve). The importance of this material property has until now been neglected in waste and rest products contexts. There is an eminent need for knowledge of the water holding properties of ash and rest products in order to improve the possibility to perform i) assessment of leaching from rest product used in constructions, ii) dimensioning of covers built with rest products and iii) assessment of long term properties of land fill waste concerning leaching, especially for stabilized ash with a monolithic characteristics. The aim of this project was to increase the knowledge of the water holding properties of ashes by determining water retention curves with laboratory methods on four ash materials with the potential to be used in constructions. In the project, four ashes has been studied; one MSWI bottom ash from SYSAV, one aged MSWI bottom ash from Gaerstadverket and two fly ashes from incineration of biofuels; one from SCA Ortviken and one from Jaemtkraft AB. For comparison, data from a silt soil studied in another SGI project is presented. When determining a water retention curve for a specific material water from the examined, beforehand water saturated, sample is eliminated under controlled circumstances in a pressure plate extractor. The sample is exposed to a pressure, with increasing degree, squeezing excess water out of the material. The excess water is measured for each increased pressure step and the remaining volumetric water content in the material can be calculated. The results from such measurements are presented in water retention curves, in which the volumetric water content is plotted as a function of the capillary pressure. The water retention curves shows how various materials differ in water content at the same pressure. The results from the study showed that ashes have great water holding capacity. The study also

  4. Weathering behaviour of overburden-coal ash blending in relation to overburden management for acid mine drainage prevention in coal surface mine

    International Nuclear Information System (INIS)

    Potentially acid forming (PAF) materials are encapsulated with non-acid forming materials (NAF) in order to prevent acid mine drainage (AMD) in surface coal mines. NAF compaction techniques with fly and bottom ashes from coal-fired power plants are used in mines with limited amounts of NAF materials. This study investigated the weathering behaviour of blended overburden and coal combustion ash in laboratory conditions. Free draining column leach tests were conducted on different blending schemes. The weathering process was simulated by spraying the samples with de-ionized water once per day. The leachates were then analyzed using X-ray diffraction and fluorescence analyses in order to identify the mineral composition of the samples over a 14 week period. Results of the study indicated that the weathering process plays a significant role in controlling infiltration rates, and may increase the capability of capping materials to prevent infiltration into PAF materials. Fly- and bottom-ash additions improved the performance of the encapsulation materials. 3 refs., 4 tabs., 2 figs.

  5. 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.

  6. Influence of low permeability zone in blast furnace hearth on temperature distribution in furnace bottom and on iron and slag tapping indices. Koro rosho ni okeru teitsuekisei ryoiki no rotei ondo bunpu oyobi shussensai ni oyobosu eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Sawa, Y.; Takeda, K.; Taguchi, S.; Matsumoto, T.; Watanabe, Y.; Kamano, H. (Kawasaki Steel Corp., Tokyo (Japan))

    1992-07-01

    The furnace bottom brick temperature which controls the brick erosion of blast furnace bottom and the heat transfer condition of blast furnace hearth relating directly to the tapping, are studied by laboratory experiments and plant data analysis using cylindrical furnace as experimental apparatus. The temperature of the blast furnace hearth is repeated by two conditions, high temperature period and low temperature period. It is found that a zone of low permeability against the molten iron and the slag flow has existed over a wide area when the temperature at furnace bottom is low. The reason for the formation of low permeability zone has not been cleared, however it has been formed from the crystallized kiss graphite from low temperature molten iron at furnace bottom, ashes left at the furnace bottom while quenching the coal, pulverized coal and unburnt char during injection of powder coal, and this has caused the choking of coke packed bed. The concept of low permeability zone has made possible to interpret the transition of bottom bricks temperature, differences in the metal tap hole and the correlation between the flow-out index of slag and the bottom brick temperature. 17 refs. 18 figs., 2 tabs.

  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. Laser bottom hole assembly

    Science.gov (United States)

    Underwood, Lance D; Norton, Ryan J; McKay, Ryan P; Mesnard, David R; Fraze, Jason D; Zediker, Mark S; Faircloth, Brian O

    2014-01-14

    There is provided for laser bottom hole assembly for providing a high power laser beam having greater than 5 kW of power for a laser mechanical drilling process to advance a borehole. This assembly utilizes a reverse Moineau motor type power section and provides a self-regulating system that addresses fluid flows relating to motive force, cooling and removal of cuttings.

  9. Enrichment and particle size dependence of polonium and other naturally occurring radionuclides in coal ash

    International Nuclear Information System (INIS)

    Coal fired thermal power contributes 70% of power in India. Coal fired power generation results in huge amounts of fly ash and bottom ash of varying properties. Coal, which contains the naturally occurring radionuclides, on burning results in enrichment of these radionuclides in the ashes. In the present study, coal, bottom ash and fly ash samples collected from six coal-fired power plants in India were measured for 210Po using alpha spectrometry and for natural U, 226Ra, 232Th and 40K by an HPGe γ-ray spectrometer. 210Po in fly ash ranged from 25.7 to 70 Bq/kg with a mean value of 40.5 Bq/kg. The range and mean activities of 238U, 226Ra, 232Th, 40K in fly ash were 38.5–101 (78.1), 60–105.7 (79), 20–125 (61.7) and 43.6–200 (100) Bq/kg respectively. Fly ash and bottom ash contains two to five times more natural radionuclides than feed coal. The results were compared with the available data from earlier studies in other countries. The effect of particle size on enrichment factor of the nuclides in fly ash was studied. 210Po showed the largest size dependence with its concentration favoring the smaller particle size while 232Th showed least size dependence. 238U and 226Ra showed behavior intermediate to that of 210Po and 232Th. Also the correlation between sulfur content of the feed coal and activity of 210Po was investigated. Increased sulfur content in feed coal enhanced enrichment of 210Po in ash

  10. Occurrence of volcanic ash in the Quaternary alluvial deposits, lower Narmada basin, western India

    Indian Academy of Sciences (India)

    Rachna Raj

    2008-02-01

    This communication reports the occurrence of an ash layer intercalated within the late Quaternary alluvial succession of the Madhumati River, a tributary of the lower Narmada River. Petrographic, morphological and chemical details of glass shards and pumice fragments have formed the basis of this study. The ash has been correlated with the Youngest Toba Tuff. The finding of ash layer interbedded in Quaternary alluvial sequences of western Indian continental margin is significant, as ash being datable material, a near precise time-controlled stratigraphy can be interpreted for the Quaternary sediments of western India. The distant volcanic source of this ash requires a fresh re-assessment of ash volume and palaeoclimatic interpretations.

  11. Metal release from fly ash upon leaching with sulfuric acid or acid mine drainage

    International Nuclear Information System (INIS)

    Generation of electricity by coal-fired power plants produces large quantities of bottom ash and fly ash. New power plants commonly use fluidized bed combustion (FBC) boilers, which create ashes with high neutralization potential (NP). These ashes, due to their alkaline nature, are often used in surface mine reclamation to neutralize acidity and reduce hydraulic conductivity of disturbed overburdens. Conventional fly ashes from older power plants exhibit a range of pH and NP, with some ashes having neutral or acidic pH and low NP values, and may not be good candidates for supplying alkalinity in reclamation projects. In this study, the authors used two acidic solutions to leach a low NP fly ash (LNP ash) and two FBC ashes (FBC1 and FBC2). After passing 78 pore volumes of sulfuric acid and 129 pore volumes of acid mine drainage (AMD) through these ash materials several trace elements were found at high levels in the leachates. LNP fly ash leachates had high arsenic and selenium concentrations with sulfuric acid leaching, but showed low arsenic and selenium concentrations after leaching with AMD. Leaching with AMD caused the iron and aluminum inherent in AMD to complex these elements and make them unavailable for leaching. Lead, cadmium, and barium concentrations in fly ash leachates were not high enough to cause water pollution problems with either leaching solution. For both leaching solutions, manganese was released from LNP ash at a constant level, FBC1 ash did not release manganese, and FBC2 ash released manganese only after the NP had been exhausted by >60 pore volumes of leaching

  12. Sulfate resistance of high calcium fly ash concrete

    Science.gov (United States)

    Dhole, Rajaram

    -fly ash pastes confirmed that fly ash mortar or concrete mixes forming more monosulfate than ettringite before exposure to sulfates would offer poor sulfate resistance and vice versa. During quantitative Rietveld analysis carried out for determining ettringite, monosulfate and gypsum formed in the fly ash pastes, it was observed that fly ash mixtures showing more ettringite after exposures to sulfates, give poor sulfate resistance. A good relationship between the amounts of ettringite formed and expansions of mortar specimens in the ASTM C 1012 test was found.

  13. The Laconia, New Hampshire Bottom, Ashi Paving Project. Volume 1: Environmental testing report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    Bottom ash is the principal waste stream fro m the combustion of municipal solid waste (MSW). It is comprised of grate ash (97%), the slag material discharged at the end of the grate system and grate sffting (3%), the material that melts or falls through the grate structure. This project was conducted to demonstrate the feasibility of using municipal solid waste grate ash as an aggregate substitute in the construction of a pavement binder course for a portion of Rt. 3 in Laconia, New Hampshire. The research was conducted over a two year period during 1993 and 1994. This study is the culmination of an earlier two year characterization study between 1990 and 1992 that documented the physical and environmental characteristics of the bottom ash as it was produced at the Concord, N.H. waste-to-energy (WTE) facility and used in an asphaltic binder course. Together, these two studies provide a complete evaluation of the potential for using grate ash or bottom ash in asphalt binder course or as recycled asphalt pavement (RAP) in base courses in pavements.

  14. 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.

  15. Mössbauer Studies of Thermal Power Plant Coal and Fly Ash

    Science.gov (United States)

    Taneja, S. P.

    Iron-57 Mössbauer spectroscopic studies were carried out at room temperature on samples of coal, slag (bottom ash) and mechanical ash collected from Bhatinda (India) thermal power plant. Hyperfine parameters such as isomer shift, quadrupole splitting and total internal magnetic field of 57Fe nuclei were used to characterize various iron-bearing minerals. The observed parameters indicate the presence of pyrite, siderite and ankerite in coal sample while magnetic fractions of mechanical ash and slag samples show the formation of hematite and Al-substituted magnesio-ferrite. The non-magnetic fraction of slag ash shows the dominance of Fe2+ phases while that of mechanical ash demonstrates the formation of both Fe2+ and Fe3+ phases. These findings are compared with Mössbauer and magnetic susceptibility studies on fly ash samples of Panipat (India) thermal power plant reported earlier.

  16. Influence of feed and sampling systems on element partitioning in Kentucky fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Valentim, Bruno V. [Centro e Departamento de Geologia Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre 687, 4169-007, Porto (Portugal); Hower, James C. [University of Kentucky Center for Applied Energy Research (CAER), Lexington, Kentucky, 40511 (United States)

    2010-05-01

    Pentannual surveys of the production of coal combustion byproducts in Kentucky utility power plants, along with other studies in the intervening years has resulted in a large amount of data relating coal chemistry, fly ash (FA) chemistry, and, to a lesser degree, bottom ash chemistry. Therefore, this important collection of data enables to perform studies on a wide variety of fly ash types. The chemical classification, based on major oxides (acid, alkaline, and Fe{sub 2}O{sub 3}), of coal high-temperature ash (HTA) and FA from Kentucky Power Plants shows that the majority of the coal HTAs are Sialic, Sialic-Ferrisialic, and Ferrisialic. The FA classification not only depends of the coal HTA chemistry but also the ash-collection system and the sampling position, with the implications of flue gas temperature and ash particle size, within the system. (author)

  17. Waste ashes for use in agricultural production: I. Liming effect, contents of plant nutrients and chemical characteristics of some metals.

    Science.gov (United States)

    Zhang, Fu-Shen; Yamasaki, S; Nanzyo, M

    2002-02-01

    The chemical characteristics of 89 municipal waste ashes, including food scrap ash (FSA), animal waste ash (AWA), horticulture waste ash (HWA), sewage sludge ash (SSA) and incinerator bottom ash (IBA), from various locations in Japan were examined with the aim of evaluating their suitability for use in agriculture. Although the waste ashes came from different sources and consisted of various materials, the gross elemental composition was similar. Acid neutralization capacity (liming effect) for the waste ashes was equivalent to 10-30% of CaO and followed the sequence SSA > IBA > AWA > FSA > HWA. Average P concentrations for the five types of waste ashes ranged from 10 to 29 g kg(-1) and average K concentrations ranged from 14 to 63 g kg(-1), respectively. Metal contents in the waste ashes were compared with levels in Japanese agricultural soils. K in the waste ashes was 1.3-6 times higher and Ca was 3-12 times higher; contents of the other metals in FSA, AWA and HWA were generally less than five times higher, but Ni, Cu, Zn, Cd, Sn, Pb in SSA or IBA were approximately 10-200 times higher than those in soils. Moreover, the ceiling amounts of waste ashes that may be applied to main Japanese agricultural soils were calculated by using soil contamination standards for Cu. Water solubility of P and metals in the waste ashes were also examined. PMID:11846166

  18. 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

  19. Polonium and other naturally occurring radionuclides in fly ash from coal fired thermal power plants

    International Nuclear Information System (INIS)

    Coal fired thermal power is the largest contributing power sector in India (about 70%) along with 25 hydel power generation, 3% nuclear power generation and about 1% wind power generation Power on demand by 2012. The role of GIS, GPS and remote sensing in power sector. Published by, CSDMS, IT for geography. The increasing demand of power in a developing country like India has resulted in rapid increase in thermal generation capacity. The coal fired power generation results in huge amounts of fly ash and bottom ash of varying properties. Coal which contains the naturally occurring radionuclides, on burning results in enrichment of these radionuclides in the ashes. In the present study, coal, bottom ash and fly ash samples collected from six coal-fire power plants in India were measured for 210Po using alpha spectrometry and natural U, 226Ra, 232Th and 40K by an HPGeã-ray spectrometer. The results show that fly ash or bottom ash contains two to five times more natural radionuclides than feed coal. The results were compared with the available data from earlier studies in other countries. (author)

  20. 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....

  1. 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.

  2. 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

  3. Toxicity of and metals in coal combustion ash leachate

    International Nuclear Information System (INIS)

    Land disposal of coal combustion ash can have a potential impact on the ecosystem due to the leaching of metals with increasing acidity of precipitation. The effect of pH on the concentration of metals leached from coal combustion ash was studied and the toxicity of the leachate measured. Bottom coal combustion ash was leached with hydrochloric acid (HCl) or acetic acid (CH3COOH) at pH 4,5,6 or 7. The toxicity of the aqueous leachates and concentrations of the metals (arsenic, cadmium, chromium, copper, iron, lead, nickel, silver and zinc) therein were measured using Microtox (Vibrio fischeri-EC50%) and atomic absorption spectrophotometry, respectively. Toxicity and metal concentrations of the leachates were highest when ash was leached with HCl at pH 4. Toxicity and metal concentrations of ash leached with CH3COOH were significantly lower compared with ash leached with HCl. A high correlation was observed between the toxicity and the metal concentrations in both the acid leachates

  4. 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.

  5. 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. 

  6. 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)

  7. 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...

  8. T.sup.0./sup. peat-forming plant assemblage preserved in growth position by volcanic ash-fall: A case study from the Middle Pennsylvanian of the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Opluštil, S.; Pšenička, J.; Bek, Jiří; Wang, J.; Feng, Z.; Libertín, M.; Šimůnek, Z.; Bureš, J.; Drábková, J.

    2014-01-01

    Roč. 89, č. 4 (2014), s. 773-813. ISSN 1214-1119 R&D Projects: GA ČR GAP210/12/2053 Institutional support: RVO:67985831 Keywords : Pennsylvanian * T 0 plant assemblage * coal forests * volcanic ash beds * Radnice Basin Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.515, year: 2014

  9. Best management practices plan for the Chestnut Ridge-Filled Coal Ash Pond at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    The Chestnut Ridge Filled Coal Ash Pond (FCAP) Project has been established to satisfy Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) requirements for the Chestnut Ridge Operable Unit 2. FCAP is on Chestnut Ridge, approximately 0.5 miles south of the Y-12 Plant. A 62-foot high earthen dam across Upper McCoy Branch was constructed in 1955 to create a pond to serve as a settling basin for fly and bottom ashes generated by burning coal at the Y-12 Steam Plant. Ash from the steam was mixed with water to form a slurry and then pumped to the crest of Chestnut Ridge and released through a large pipe to flow across the Sluice Channel area and into the pond. The ash slurry eventually overtopped the dam and flowed along Upper McCoy Branch to Rogers Quarry. The purpose of this document is to provide a site-specific Best Management Practices (BMP) Plan for construction associated with environmental restoration activities at the FCAP Site

  10. Ash transformation and deposition behavior during co-firing biomass with sewage sludge

    DEFF Research Database (Denmark)

    Wang, Liang; Wu, Hao; Jensen, Peter Arendt;

    In the present work, the ash transformation and deposition behavior during wheat straw and wood waste combustion were investigated by combustion experiments in an entrained flow reactor. The influence of sewage sludge addition on ash chemistry and deposition tendency was also studied. During......-Ca-silicates. The deposits formed on a well-controlled sampling probe are dominated by molten particles rich in K silicates. Over 70% of K in the fly ash is water soluble. The fine fly ash from wood waste combustion consists of mainly KCl and NaCl. Both ash clusters and molten spherical particles are found from the...... ash deposits, which mainly contain K-silicates, K-Al-silicates and K-Ca-silicates. The sewage sludge addition significantly reduced the water soluble K and Na in the fly ash from wheat straw and wood waste combustion. Compared to pure wheat straw and wood waste, the ash deposition rates were increased...

  11. Morphological and Strength Properties of Tanjung Bin Coal Ash Mixtures for applied in Geotechnical Engineering Work

    Directory of Open Access Journals (Sweden)

    Abd. Rahim Awang

    2012-01-01

    Full Text Available In Malaysia, coal has been used as a raw material to generate electricity since 1988. In the past, most of the wastage of coal burning especially the bottom ash was not managed properly as it was dumped in the waste pond and accumulated drastically.This paper focuses on some properties of coal ash mixtures (fly  ash and bottom ash mixtures from Tanjung Bin power plant. The characteristics studied were morphological properties, compaction behaviour and strength properties. Strength properties of coal ash mixtures are carried out by conducting direct shear test and unconfined compression test. Besides, morphology and mineralogy of coal ash mixtures are studied using scanning electron microscope (SEM and x-ray diffraction (XRD. The coal ash mixtures were compacted at 95% of maximum dry density, sealed and cured for 0, 14, and 28 days before they were analysed for shear strength, morphological and mineralogical analyses. The shear strength of coal ash mixtures varied depending on the fly ash compositions. The maximum shear strength was obtained at mixture with 50%FA: 50%BA and the value increased with curing periods. The friction angle obtained ranged from 27° to 37°. Morphological analysis showed that the number of irregular shaped particles increased confirming change in material type with curing period. From mineralogical analysis, the crystalline compounds present in Tanjung Bin coal ash were Mullite, Quartz, Calcium Phosphide, Calcite, Cristobalite and Hematite. It can be concluded that the coal ash mixtures can advantageously be applied in the construction of embankments, roads, reclamation and fill behind retaining structures.

  12. 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.

  13. Combustion Air Pre-heating from Ash Sensible Heat in Municipal Waste Incineration Systems

    OpenAIRE

    Zakariya Kaneesamkandi

    2014-01-01

    Heat recovery from bottom ash is more important in municipal waste combustion systems than in any other solid fuel combustion since almost 50% of it comprises of non-combustibles. In this study, an ash cooling system using air as the cooling medium has been modeled for pre-heating the combustion air. Air cooling has several advantages over water cooling methods. The study involves modeling using Gambit tool and is solved with the fluent solver. Municipal solid waste incineration systems have ...

  14. 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...

  15. 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...

  16. Use of sugar-cane bagasse ash to produce glass-ceramic material in the system Ca O-SiO{sub 2}-Na{sub 2}O; Utilizacao de cinza de bagaco de cana para produzir material vitro-ceramico do sistema SiO{sub 2}-CaO-Na{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, S.R.; Santos, G.T.A.; Magalhaes, R.S., E-mail: rainho@fct.unesp.b [Universidade Estadual Paulista (DFQB/FCT/UNESP), Presidente Prudente, SP (Brazil). Fac. de Ciencias e Tecnologia. Dept. de Fisica, Quimica e Biologia; Rincon, J.Ma.; Romero, M. [Consejo Superior de Investigaciones Cientificas (IETCC/CSIC), Madri (Spain). Inst. de Ciencias de la Construccion Eduardo Torroja; Carvalho, C.L. [Universidade Estadual Paulista (FEIS/UNESP), Ilha Solteira, SP (Brazil). Faculdade de Engenharia

    2009-07-01

    A bottom ash was used as raw material to obtain glass which was crystallized to form glass-ceramic material. The characterization of the ash shows that it consists mainly of crystalline materials, predominantly quartz, with oxides of iron, potassium and aluminum as minor elements. The glass was obtained from the mixing of ash with calcium and sodium carbonates. The glass and the glass-ceramic were examined using differential thermal analysis (DTA), X-ray fluorescence (XRF), X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD and DTA data show that Wollastonita is the only crystalline phase present in the material crystallized at 1050 deg C. Part of the glass was synthesized at this temperature for one hour, resulting in a green/brown hard material glass-ceramic. The images of SEM show morphology of spherilithic growth indicating volumetric crystallization mechanism. (author)

  17. Impact of coal fly ash addition on ash transformation and deposition in a full-scale wood suspension-firing boiler

    DEFF Research Database (Denmark)

    Wu, Hao; Bashir, Muhammad Shafique; Jensen, Peter Arendt;

    2013-01-01

    Ash transformation and deposition during pulverized wood combustion in a full-scale power plant boiler of 800 MWth were studied with and without the addition of coal fly ash. The transient ash deposition behavior was characterized by using an advanced deposit probe system at two boiler locations...... of the deposits. Overall, the results from this work suggest that coal fly ash can be an effective additive to minimize the possible ash deposition and corrosion problems during suspension-firing of wood. © 2013 Elsevier Ltd. All rights reserved....... constant after a few hours. The formed deposits, especially those at the location with low flue gas temperatures, contained a considerable amount of K2SO4, KCl, and KOH/K2CO3. With the addition of a large amount (about 4 times of the mass flow of wood ash) of coal fly ash to the boiler, these alkali...

  18. Sulfur-bearing coatings on fly ash from a coal-fired power plant: Composition, origin, and influence on ash alteration

    Science.gov (United States)

    Fishman, N.S.; Rice, C.A.; Breit, G.N.; Johnson, R.D.

    1999-01-01

    Fly ash samples collected from two locations in the exhaust stream of a coal-fired power plant differ markedly with respect to the abundance of thin (???0.1 ??m) sulfur-rich surface coatings that are observable by scanning electron microscopy. The coatings, tentatively identified as an aluminum-potassium-sulfate phase, probably form upon reaction between condensed sulfuric acid aerosols and glass surfaces, and are preferentially concentrated on ash exposed to exhaust stream gases for longer. The coatings are highly soluble and if sufficiently abundant, can impart an acidic pH to solutions initially in contact with ash. These observations suggest that proposals for ash use and predictions of ash behavior during disposal should consider the transient, acid-generating potential of some ash fractions and the possible effects on initial ash leachability and alteration. ?? 1998 Elsevier Science Ltd.

  19. 锅炉斜炉底安装工艺%The Installation Process of Boiler's Inclined Furnace Bottom

    Institute of Scientific and Technical Information of China (English)

    朱丹萍

    2013-01-01

    Water wall ash hopper, commonly known as inclined furnace bottom,which is named by arranged in the bottom of the furnace and the front and rear walls form a certain angle with the horizontal plane. This article describes the inclined furnace bottom lifting in the boiler's heating surface components of different capacity units, depicts the time trajectory of continuous expansion for domestic unit capacity from one side, at the same time, this article illustrates that using new lifting process could accelerate the construction schedule, improve project quality and reduce the risk of the job, and provides a new concept for the installation of large boilers.%水冷壁灰斗,俗称斜炉底,因其布置于炉膛底部且前后墙与水平面成一定的夹角而得名。本文通过对不同容量机组锅炉受热面组件中斜炉底吊装的介绍,从一个侧面描绘国内机组容量不断的扩大的时间轨迹,同时说明了利用新的吊装工艺可以加快施工进度,提高工程质量,减少危险作业,为大型锅炉的安装提供了新的施工理念。

  20. The rare earth elements in municipal solid waste incinerators ash and promising tools for their prospecting.

    Science.gov (United States)

    Funari, Valerio; Bokhari, Syed Nadeem Hussain; Vigliotti, Luigi; Meisel, Thomas; Braga, Roberto

    2016-01-15

    Bottom and fly ashes from Municipal Solid Waste Incinerators (MSWI) are hazardous products that present concern for their safe management. An attractive option to reduce their impact both on the environment and the financial commitment is turning MSWI ashes into secondary raw materials. In this study we present the REE content and distribution of bottom and fly ashes from MSWI after a highly effective digestion method and samples analysis by ICP-MS. The chondrite-normalised REE patterns of MSWI bottom and fly ash are comparable with that of crustal averages, suggesting a main geogenic source. Deviations from typical crustal pattern (e.g., Eu, Tb) disclose a contribution of likely anthropogenic provenance. The correlation with major elements indicates possible sources for REE and facilitates a preliminary resource assessment. Moreover, magnetic susceptibility measurements can be a useful prospecting method in urban ores made of MSWI ashes. The relationship between REE and some influencing parameters (e.g., Pricing Influence Factor) emphasises the importance of MSWI ash as alternative source of REE and the need of further efforts for REE recovery and purification from low concentrations but high flows waste. PMID:26414924

  1. 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)

  2. 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

  3. Merging two waste streams, wood ash and biowaste, results in improved composting process and end products.

    Science.gov (United States)

    Fernández-Delgado Juárez, M; Gómez-Brandón, M; Insam, H

    2015-04-01

    A trial was carried out to evaluate the influence of wood ash admixture on biowaste composting. The aim was to find the optimal dosage of ash addition to enhance the composting process without endangering the final compost characteristics and use. Six treatments including an unamended control (K0) and composts with additions of 3% (K3), 6% (K6), 9% (K9), 12% (K12) and 15% (K15) of wood ash (w/w) were studied. The composting process was monitored in situ for 49days, by measuring temperature, CO2, O2, and CH4 in the piles and pH, electric conductivity (EC), and inorganic N in the laboratory. At the end of the process, the products were tested for Reifegrad (maturity), toxicity and quality. The addition of up to 15% of wood ash to biowaste did not negatively affect the composting process, and the initial differences found between both the low and high ash-treated composts were attenuated with the ongoing process development. Nevertheless, and mainly due to Cd level, composts with higher ash amendment did not comply with the highest quality standards established by the Austrian Compost Ordinance. The failure of obtaining class A+ quality after ash amendment emphasizes the need for a rigid quality selection of (bottom) ashes and thus reducing environmental risks related to high pollutant loads originating from the ashes. PMID:25536175

  4. 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...

  5. Behavior of Alkali Metals and Ash in a Low-Temperature Circulating Fluidized Bed (LTCFB) Gasifier

    DEFF Research Database (Denmark)

    Narayan, Vikas; Jensen, Peter Arendt; Henriksen, Ulrik Birk;

    2016-01-01

    W and a 6 MW LTCFBgasifier. Of the total fuel ash entering the system, the largest fraction (40−50%) was retained in the secondary cyclone bottoms,while a lower amount (8−10%) was released as dust in the exit gas. Most of the alkali and alkaline earth metals were retained inthe solid ash, along with Si......, the low reactor temperature ensures that high-alkali biomass fuels canbe used without risk of bed defluidization. This paper presents the first investigation of the fate of alkali metals and ash in lowtemperaturegasifiers. Measurements on bed material and product gas dust samples were made on a 100 k...

  6. 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...

  7. Bottom grid mounted debris trap for a fuel assembly

    International Nuclear Information System (INIS)

    This patent describes a fuel assembly for a nuclear reactor including nuclear fuel rods, each fuel rod in the fuel assembly having a cladding tube and a lower end plug attached to the tube, at least a bottom grid supporting each and everyone of the fuel rods in an organized array and disposed in spaced relationship above the lower end plugs of the fuel rods. A bottom nozzle is disposed in spaced relationship below the bottom grid and is disposed below the lower end plugs of the fuel rods. A coolant flows upwardly through the bottom nozzle and to the bottom grid. A trap is included for catching debris carried by the flowing coolant to substantially prevent the same from reaching the bottom grid. The debris trap comprises: a fuel rod nonsupport structure disposed completely across the entire expanse of the fuel assembly and axially between the bottom nozzle and the bottom grid and generally aligned with the lower end plugs of the fuel rods. The structure forms hollow cells each being open at opposite ends and defining a central cavity which receives one of the fuel rod lower end plugs in nonsupporting and noncontacting relationship while providing for passage of coolant flow therethrough from the bottom nozzle to the bottom grid. Each of the fuel rod lower end plugs extends into a respective hollow cell of the structure

  8. Comparison of fly ash properties from Afsin-Elbistan coal basin, Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Ural, Suphi [Department of Mining Engineering, Cukurova University, 01330 Adana (Turkey)]. E-mail: suralp@mail.cu.edu.tr

    2005-03-17

    Afsin-Elbistan (AE) coal fly ashes obtained by burning coal samples from top, middle and bottom sections of the AE coal seam were characterized and their properties were compared. Chemical analysis of the AE coal fly ashes showed that they are mainly composed of CaO, SiO{sub 2}, Fe{sub 2}O{sub 3} and Al{sub 2}O{sub 3}. Quantitative X-ray diffraction (XRD) analyses were carried out using an interactive data processing system (SIROQUANT{sup TM}) based on Rietveld interpretation methods. Lime is found in all the samples, ranging from around 7% to just over 38%. Amorphous contents of fly ashes are ranged between 19% and 25%. Different types of AE fly ashes revealed that bottom section coal fly ash is very similar to Class F, while medium and top section coal fly ashes are close to Class C and they might be used as mineral admixture in concrete. But also they do not comply with any of the standard. The results presented here show new possibilities for AE coal fly ashes in a wide range of fields, resulting in great advantages in waste minimization, as well as, resources conservation.

  9. Phenolic acids as bioindicators of fly ash deposit revegetation

    Energy Technology Data Exchange (ETDEWEB)

    L. Djurdjevic; M. Mitrovic; P. Pavlovic; G. Gajic; O. Kostic [Institute for Biological Research ' Sinisa Stankovic,' Belgrade (Serbia and Montenegro). Department of Ecology

    2006-05-15

    The floristic composition, the abundance, and the cover of pioneer plant species of spontaneously formed plant communities and the content of total phenolics and phenolic acids, as humus constituents, of an ash deposit after 7 years of recultivation were studied. The restoration of both the soil and the vegetation on the ash deposits of the 'Nikola Tesla-A' thermoelectric power plant in Obrenovac (Serbia) is an extremely slow process. Unfavorable physical and chemical characteristics, the toxicity of fly ash, and extreme microclimatic conditions prevented the development of compact plant cover. The abundance and cover of plants increased from the central part of the deposit towards its edges. Festuca rubra L., Crepis setosa Hall., Erigeron canadensis L., Cirsium arvense (L.) Scop., Calamagrostis epigeios (L.) Roth., and Tamarix gallica L. were the most abundant species, thus giving the highest cover. Humus generated during the decomposition process of plant remains represents a completely new product absent in the ash as the starting material. The amount of total phenolics and phenolic acids in fly ash increased from the center of the deposit towards its edges in correlation with the increase in plant abundance and cover. The presence of phenolic acids indicates the ongoing process of humus formation in the ash, in which the most abundant pioneer plants of spontaneously formed plant communities play the main role. Phenolic compounds can serve as reliable bioindicators in an assessment of the success of the recultivation process of thermoelectric power plants' ash deposits.

  10. Delineation of a volcanic ash body using electrical resistivity profiling

    International Nuclear Information System (INIS)

    Four lines of electrical resistivity profiling (ERP) were performed to define the extent of a shallow Quaternary volcanic ash deposit being mined in the United States. Inversion results of ERP proved suitable for defining the thickness and lateral extent of the volcanic ash deposit at this testing site. These interpretations were confirmed by shallow borehole drilling. The model sensitivity information indicates that inverted models possess sufficient resolving power down to a depth of 7 m and are fairly consistent in terms of horizontal resolution along the four ERP lines. The bottom of most of the volcanic ash deposit in the study area is less than 7 m in depth. Based on synthesis of the ERP and drill information, the limits of the mineable ash bed resources were clearly defined. Moreover, by integrating the ERP results with a minimal number of optimally placed borings, the volume of the volcanic ash deposit was established at a lesser cost, and with greater accuracy than would be possible with a traditionally designed grid drilling programme

  11. MSWI boiler fly ashes: magnetic separation for material recovery.

    Science.gov (United States)

    De Boom, Aurore; Degrez, Marc; Hubaux, Paul; Lucion, Christian

    2011-07-01

    Nowadays, ferrous materials are usually recovered from Municipal Solid Waste Incineration (MSWI) bottom ash by magnetic separation. To our knowledge, such a physical technique has not been applied so far to other MSWI residues. This study focuses thus on the applicability of magnetic separation on boiler fly ashes (BFA). Different types of magnet are used to extract the magnetic particles. We investigate the magnetic particle composition, as well as their leaching behaviour (EN 12457-1 leaching test). The magnetic particles present higher Cr, Fe, Mn and Ni concentration than the non-magnetic (NM) fraction. Magnetic separation does not improve the leachability of the NM fraction. To approximate industrial conditions, magnetic separation is also applied to BFA mixed with water by using a pilot. BFA magnetic separation is economically evaluated. This study globally shows that it is possible to extract some magnetic particles from MSWI boiler fly ashes. However, the magnetic particles only represent from 23 to 120 g/kg of the BFA and, though they are enriched in Fe, are composed of similar elements to the raw ashes. The industrial application of magnetic separation would only be profitable if large amounts of ashes were treated (more than 15 kt/y), and the process should be ideally completed by other recovery methods or advanced treatments. PMID:21306886

  12. 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...

  13. “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.

  14. Waste ashes for use in agricultural production: II. Contents of minor and trace metals.

    Science.gov (United States)

    Zhang, Fu-Shen; Yamasaki, S; Kimura, K

    2002-03-01

    The present study was carried out to examine the contents of 18 minor and trace metals in five typical municipal waste ashes in Japan. In the waste ashes, Li, Ga, Rb, Y, Zr had relatively higher concentrations, approximately 5-300 mg kg(-1), the remaining metal concentrations were generally approximately 0.05-20 mg kg(-1). A comparison of the metal concentrations in the waste ashes and in Japanese agricultural soils indicated that the ratios for Ga, Mo, Ag, Sb, W, Bi between sewage sludge ash (SSA) and the soils were approximately 10-100 and for the remaining metals approximately 0.2-2; the ratios between food scrap ash (FSA), animal waste ash (AWA), horticulture waste ash (HWA) and incinerator bottom ash (IBA) and the soils were approximately 0.2-5. Furthermore, an overall evaluation on the waste ashes was also carried out using factor analysis with the addition of the other 21 elements examined in a companion paper. In the waste ashes, the major nutrient elements and heavy metals were mainly described by four factors: factors 1 and 2 explained the main information of the minor and trace metals while factors 3 and 4 explained that of the major nutrient elements. Factor 2 in the score plots could be used to evaluate the potential risk of the waste ashes to agricultural soils. Of the five types of waste ashes, SSA and IBA were abundant with minor and trace metals; AWA was relatively abundant with major nutrient elements especially for K; FSA was relatively abundant with major nutrient elements except for K, while HWA was not abundant with either of them. PMID:11886086

  15. Measurement of bottom-reflected sound in bottom-limited propagation environment

    Science.gov (United States)

    Hahn, Jooyoung; Park, Joungsoo

    2016-07-01

    To study the bottom reflection of underwater acoustic sound in a bottom-limited propagation environment, an experiment was conducted using four transmitting sounds in the form of a continuous wave from 1 to 6 kHz. The site of the experiment was a continental shelf region off the east coast of Korea where the bottom was composed of sandy mud. The mean water depth was 1100 m in the experiment area. Oceanographic data and acoustic data were collected simultaneously during the experiment. It was found that the sound pressure level decreased by 90 dB to 3.4 km and there is little frequency dependence because a strong direct path contributes more than a bottom-reflected path in sound pressure level. At a range between 6 and 7 km, there is a strong bottom-reflected ray path and frequency dependence exists because the bottom reflection loss varies with frequency at a given grazing angle. Sound pressure levels increase as the range increases between 6 and 7 km by 5.4, 1.9, 1.7, and 1.5 dB at frequencies of 1000, 2490, 3990, and 5490 Hz, respectively.

  16. Manipulation of gasification coal feed in order to increase the ash fusion temperature of the coal to operate the gasifiers at higher temperatures / Johannes Chrisstoffel van Dyk

    OpenAIRE

    Van Dyk, Johannes Chrisstoffel

    2006-01-01

    Coal is a crucial feedstock for South Africa's unique synfuels and petrochemicals industry and used by Sasol as a feedstock to produce synthesis gas via the Sasol-Lurgi Fixed Bed Dry Bottom (FBDB) gasification process. The ash fusion temperature (AFT) gives detail information on the suitability of a coal source for gasification purposes, and specifically to the extent ash agglomeration or clinkering is likely to occur within the gasifier. Ash clinkering inside the gasifier can cause channel b...

  17. Determination and statistical evaluation of the effect of minerals and mineral associations in specific dense medium fractions on ash fusion temperature / Ashriti Govender

    OpenAIRE

    Govender, Ashriti

    2005-01-01

    During Sasol-Lurgi Fixed Bed Dry Bottom coal gasification, the mineral matter in coal undergoes various transformations. Heat induced transformation due to low ash fusion temperatures leads to agglomeration of the ash particles to sizes varying from tiny particles to lumps larger than 100mm. Channel burning and instability in the ash bed can occur as a result. It is therefore important to understand and anticipate the reactions of the mineral matter prior to feeding the coal...

  18. 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

  19. 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

  20. 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.

  1. 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...

  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. The simulation of incineration ash in a burning process

    International Nuclear Information System (INIS)

    The paper first provides some problems of taking the radioactive wastes contaminated with cesium 137 in municipal waste incineration facilities. For analyzing the behaviors of cesium in an incinerator, a computer code was developed and the results presented. Ash concentration and distribution of particulate radius are used from incineration conditions, added circumstances from consideration of the chemical reaction between cesium compounds and ashes including chemical forms and using DEM model so as applicable to a real burning facility. (S. Ohno)

  7. Ash transformation in suspension fired boilers co-firing coal and straw

    DEFF Research Database (Denmark)

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

    of flue gas cleaning equipment. This survey includes discussions on the inorganic constituents transformation during straw and coal combustion, alkali-ash and alkali sulfur reactions, a survey of power plant and test rig co-firing experiments, a discussion of equilibrium calculations, a discussion......In this literature report is provided a status for the present knowledge level on ash properties when co-firing coal and biomass. The fly ash formed in boilers using co-firing of coal and straw do have a large influence on ash deposit formation, boiler corrosion, fly ash utilization and operation...... of alkali getter experiments and a discussion of modeling of alkali reaction with kaolin. Presently there is still a need for a better understanding of especially the reaction of potassium with coal ash, thereby making better predictions of co-firing ash properties....

  8. Ash in the Soil System

    Science.gov (United States)

    Pereira, P.

    2012-04-01

    Ash is the organic and inorganic residue produced by combustion, under laboratory and field conditions. This definition is far away to be accepted. Some researchers consider ash only as the inorganic part, others include also the material not completely combusted as charcoal or biochar. There is a need to have a convergence about this question and define clear "what means ash". After the fire and after spread ash onto soil surface, soil properties can be substantially changed depending on ash properties, that can be different according to the burned residue (e.g wood, coal, solid waste, peppermill, animal residues), material treatment before burning, time of exposition and storage conditions. Ash produced in boilers is different from the produced in fires because of the material diferent propertie and burning conditions. In addition, the ash produced in boilers is frequently treated (e.g pelletization, granulation, self curing) previously to application, to reduce the negative effects on soil (e.g rapid increase of pH, mycorrhiza, fine roots of trees and microfauna). These treatments normally reduce the rate of nutrients dissolution. In fires this does not happen. Thus the implications on soil properties are logically different. Depending on the combustion temperature and/or severity, ash could have different physical (e.g texture, wettability) and chemical properties (e.g amount and type of total and leached nutrients) and this will have implications on soil. Ash can increase and decrease soil aggregation, wettablity and water retention, bulk density, runoff and water infiltration. Normally, ash increases soil pH, Electrical Conductivity, and the amount of some basic nutrients as calcium, magnesium, sodium and potassium. However it is also a potential source of heavy metals, especially if ash pH is low. However the effect of ash on soil in space and time depends especially of the ash amount and characteristics, fire temperature, severity, topography, aspect

  9. Life cycle perspective on recycling of ashes; Livscykelperspektiv paa aatervinning av askor

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, Susanna

    2007-07-01

    The purpose of this project was to, from a life cycle perspective, discuss the consequences of recycling or disposing combustion ashes. The aim was to regard regional as well as global environmental impacts and point at potential conflicts between different environmental objectives, in order to produce basic information for decision-making on criteria and regulations for ash handling.Three different ashes were studied: bottom ash from waste incineration, fly ash from combustion of peat and from forest fuels. For all ashes three different scenarios were studied, two where the ash is recycled, and one where it is disposed. Focus was put on the difference between the three scenarios during 100 years. The use of bottom ash from waste incineration for roads saved crushed rock and energy, but produced more leaching of metals than the disposal alternative. Using this ash in drainage strata saves sand but causes higher metal leaching too. The same conclusions can be drawn for fly ash from peat, here leaching of Arsenic is the main factor. Using the peat ash as road contraction material saves more resources than the use for drainage blankets. For forest fuel ash, both the use as road construction material and recycling to the forest saves resources and energy. Recycling to the forest saves most energy but also the resources of Zinc, Phosphorous and Dolomite. Leaching of metals is most important for the forest recycling, and the nature of this resource recycling can be argued. The results are most sensitive concerning transports and leaching, but also for maintenance of the constructions where the ash is used. For the forest fuel ash, the suppositions about the necessity of compensation for nutrients removed with the fuel, have important effects for the result. Generally it can be said, for all three cases, that the estimates of leaching of metals are very uncertain, and that there is a need to develop the existing models for long term leaching. The three cases demonstrated

  10. Investigation of diesel ash particulate matter: A scanning electron microscope and transmission electron microscope study

    Science.gov (United States)

    Liati, A.; Dimopoulos Eggenschwiler, P.; Müller Gubler, E.; Schreiber, D.; Aguirre, M.

    2012-03-01

    Investigation of ash PM deposited in a diesel particulate filter (DPF) operating on a light truck by means of SEM and TEM reveals the following: ash inside the DPF occurs in form of chemically very inhomogeneous, mostly brittle agglomerates accumulated at the plugged ends of inlet channels and deposited directly on the inlet channel walls all along the filter length. Ash agglomerates occur within pores of the channel walls. A minor part of ash PM may escape to the atmosphere. The individual ash phases are mostly crystalline with round outlines and sizes between ca. 170 and 60 nm, down to 7-12 nm, that is far below the breathable size range PM10. Aggregation of the predominantly finest fraction of ash particles leads to densification, which may translate to fewer breakouts from the DPF. EDX mapping and chemical analyses of the bulk ash reveal that ash consists mainly of Ca, Mg, P, Zn, S, O and minor Fe, Al and Si. Based on TEM diffraction data of ash single phases, combined with data on their chemistry, the diversity of ash phases is higher than previously presumed. Comparison with the ash particles of a heavily used DPF from a passenger car operating with Fe-based fuel-borne additives reveals characteristics very similar to those found for the light truck DPF with a tendency to generally lower sizes of the participating phases, mostly between 30 and 60 nm. 4-40 nm large, locally abundant Pt particles deriving from the coating material of the diesel oxidation catalyst (DOC) upstream the DPF occur within ash agglomerates of both DPFs. Ash collected from the exhaust gas at the exit of the light truck DPF under normal engine operation reveals that some fine particles, as well as a few of the larger (200-600 nm) ash-bearing agglomerates escape filtration. Very fine ash particles are reaching the atmosphere also attached onto soot agglomerates.

  11. 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....

  12. Bottom-up organic integrated circuits

    OpenAIRE

    Smits, Edsger C. P; Mathijssen, Simon G. J.; van Hal, Paul A.; Setayesh, Sepas; Geuns, Thomas C. T.; Mutsaers, Kees A. H. A.; Cantatore, Eugenio; Wondergem, Harry J.; Werzer, Oliver; Resel, Roland; Kemerink, Martijn; Kirchmeyer, Stephan; Muzafarov, Aziz M.; Ponomarenko, Sergei A.; de Boer, Bert

    2008-01-01

    Self- assembly - the autonomous organization of components into patterns and structures(1) - is a promising technology for the mass production of organic electronics. Making integrated circuits using a bottom- up approach involving self- assembling molecules was proposed(2) in the 1970s. The basic building block of such an integrated circuit is the self- assembled- monolayer field- effect transistor ( SAMFET), where the semiconductor is a monolayer spontaneously formed on the gate dielectric....

  13. Reactivity of oil shale ashes towards sulfur dioxide. 3. recurrent use of ash for flue gas purification

    International Nuclear Information System (INIS)

    A comparison of the reactivity of solid wastes formed during electricity production by firing pulverized Estonian oil shale was prepared and some specific characteristics of oil shale ash were pointed out. The results of the industrial-scale experiments at the Baltic Power Plants confirmed the efficiency of using cyclone ash and mud in recycle to reduce the SO2 emission by combustion of powered oil shale for electricity production

  14. Physicochemical properties and heavy metals leachability of fly ash from coal-fired power plant

    Institute of Scientific and Technical Information of China (English)

    Xiang Wei; Han Baoping; Zhou Dong; Nzihou Ange

    2012-01-01

    The physicochemical properties of fly ash from two kinds of coal-fired power plants were studied.Three aspects were examined:the micro-morphology,the mineral composition and the content of heavy met als.The results show that the fly ash from plants using a circulating fluidized bed are more irregular particles,while the particles from the plants using a pulverized coal-fired boiler are mainly spherical in shape.Quartz and mullite are the main crystalline phases in the ash.Clearly,both the technology and the coal used by a power plant can influence the mineral composition of the ash.The mineral composition of fly ash from a circulating fluidized bed is more complex than that from a pulverized coal-fired boiler.The quantity of elements found in the fly ash is greater than that found in the bottom ash for the same plant.Heavy metals are likely to be enriched in the fly ash.Heavy metal leachability was studied using two leaching methods.The results indicate that most of the heavy metals that leached during either batch leaching or column leaching experiments did not exceed the related maximum concentration standards.But Ni concentrations in the leachates from both batch and column tests exceed the standard.The highest excess rates in both tests were 572% and 497%,which levels might threaten the environment.

  15. Evaluation of Vitrification Processing Step for Rocky Flats Incinerator Ash

    International Nuclear Information System (INIS)

    In 1997, Pacific Northwest National Laboratory (PNNL) staff developed a processing option for incinerator ash at the Rocky Flats Environmental Technology Sites (RFETS). This work was performed with support from Los Alamos National Laboratory (LANL) and Safe Sites of Colorado (SSOC). A description of the remediation needs for the RFETS incinerator ash is provided in a report summarizing the recommended processing option for treatment of the ash (Lucy et al. 1998). The recommended process flowsheet involves a calcination pretreatment step to remove carbonaceous material followed by a vitrification processing step for a mixture of glass tit and calcined incinerator ash. Using the calcination pretreatment step to remove carbonaceous material reduced process upsets for the vitrification step, allowed for increased waste loading in the final product, and improved the quality of the final product. Figure 1.1 illustrates the flow sheet for the recommended processing option for treatment of RFETS incinerator ash. In 1998, work at PNNL further developed the recommended flow sheet through a series of studies to better define the vitrification operating parameters and to address secondary processing issues (such as characterizing the offgas species from the calcination process). Because a prototypical rotary calciner was not available for use, studies to evaluate the offgas from the calcination process were performed using a benchtop rotary calciner and laboratory-scale equipment (Lucy et al. 1998). This report focuses on the vitrification process step after ash has been calcined. Testing with full-scale containers was performed using ash surrogates and a muffle furnace similar to that planned for use at RFETS. Small-scale testing was performed using plutonium-bearing incinerator ash to verify performance of the waste form. Ash was not obtained from RFETS because of transportation requirements to calcine the incinerator ash prior to shipment of the material. Because part of

  16. 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

  17. 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).

  18. Bioaccessibility and health risk of heavy metals in ash from the incineration of different e-waste residues.

    Science.gov (United States)

    Tao, Xiao-Qing; Shen, Dong-Sheng; Shentu, Jia-Li; Long, Yu-Yang; Feng, Yi-Jian; Shen, Chen-Chao

    2015-03-01

    Ash from incinerated e-waste dismantling residues (EDR) may cause significant health risks to people through ingestion, inhalation, and dermal contact exposure pathways. Ashes of four classified e-waste types generated by an incineration plant in Zhejiang, China were collected. Total contents and the bioaccessibilities of Cd, Cu, Ni, Pb, and Zn in ashes were measured to provide crucial information to evaluate the health risks for incinerator workers and children living in vicinity. Compared to raw e-waste in mixture, ash was metal-enriched by category incinerated. However, the physiologically based extraction test (PBET) indicates the bioaccessibilities of Ni, Pb, and Zn were less than 50 %. Obviously, bioaccessibilities need to be considered in noncancer risk estimate. Total and PBET-extractable contents of metal, except for Pb, were significantly correlated with the pH of the ash. Noncancer risks of ash from different incinerator parts decreased in the order bag filter ash (BFA) > cyclone separator ash (CFA) > bottom ash (BA). The hazard quotient for exposure to ash were decreased as ingestion > dermal contact > inhalation. Pb in ingested ash dominated (>80 %) noncancer risks, and children had high chronic risks from Pb (hazard index >10). Carcinogenic risks from exposure to ash were under the acceptable level (<10(-6)) both for children and workers. Exposure to ash increased workers' cancer risks and children's noncancer risks. Given the risk estimate is complex including toxicity/bioaccessibility of metals, the ways of exposure, and many uncertainties, further researches are required before any definite decisions on mitigating health risks caused by exposure to EDR incinerated ash are made. PMID:25249049

  19. 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.

  20. Potential of phosphorus recovery from sewage sludge and manure ash by thermochemical treatment.

    Science.gov (United States)

    Havukainen, Jouni; Nguyen, Mai Thanh; Hermann, Ludwig; Horttanainen, Mika; Mikkilä, Mirja; Deviatkin, Ivan; Linnanen, Lassi

    2016-03-01

    All life forms require phosphorus (P), which has no substitute in food production. The risk of phosphorus loss from soil and limited P rock reserves has led to the development of recycling P from industrial residues. This study investigates the potential of phosphorus recovery from sewage sludge and manure ash by thermochemical treatment (ASH DEC) in Finland. An ASH DEC plant could receive 46-76 kt/a of sewage sludge ash to produce 51-85 kt/a of a P-rich product with a P2O5 content of 13-18%, while 320-750 kt/a of manure ash could be supplied to produce 350-830 kt/a of a P-rich product with a P content of 4-5%. The P2O5 potential in the total P-rich product from the ASH DEC process using sewage sludge and manure ash is estimated to be 25-47 kt/a, which is significantly more than the P fertilizer demand in Finland's agricultural industries. The energy efficiency of integrated incineration and the ASH DEC process is more dependent on the total solid content and the subsequent need for mechanical dewatering and thermal drying than on the energy required by the ASH DEC process. According to the results of this study, the treated sewage sludge and manure ash using the ASH DEC process represent significant potential phosphorus sources for P fertilizer production. PMID:26810030

  1. Suspension-firing of wood with coal ash addition: Probe measurements of ash deposit build-up at Avedøre Power Plant (AVV2)

    DEFF Research Database (Denmark)

    Shafique Bashir, Muhammad; Jensen, Peter Arendt; Jappe Frandsen, Flemming;

    This report is about full-scale probe measurements of deposit build-up and removal conducted at the Avedøreværket Unit 2, a 800 MWth suspension boiler, firing wood and natural gas with the addition of coal ash. Coal ash was used as an additive to capture potassium (K) from wood-firing....... Investigations of deposit formation rate were made by use of an advanced online ash deposition/shedding probe. Quantification of ash deposition and shedding was made via deposit mass uptake signals obtained from the deposit probe. The influence of coal ash, flue gas temperature, probe surface temperature...... oC), deposit removal through surface melting was not identified. SEM-EDS analysis of the deposits showed significant presence of Ca, Al and Si, indicating that a significant amount of K has been captured by coal ash to form deposits rich in calcium-aluminum-silicates, and possible release of Cl...

  2. Distribution of arsenic and mercury in lime spray dryer ash

    Energy Technology Data Exchange (ETDEWEB)

    Panuwat Taerakul; Ping Sun; Danold W. Golightly; Harold W. Walker; Linda K. Weavers [Ohio State University, Columbus, OH (United States). Department of Civil and Environmental Engineering and Geodetic Science

    2006-08-15

    The partitioning of As and Hg in various components of lime spray dryer (LSD) ash samples from a coal-fired boiler was characterized to better understand the form and fate of these elements in flue gas desulfurization byproducts. LSD ash samples, collected from the McCracken Power Plant on the Ohio State University campus, were separated by a 140-mesh (106 {mu}m) sieve into two fractions: a fly-ash-/unburned-carbon-enriched fraction (> 106 {mu}m) and a calcium-enriched fraction (< 106 {mu}m). Unburned carbon and fly ash in the material > 106 {mu}m were subsequently separated by density using a lithium heteropolytungstate solution. The concentrations of As and Hg were significant in all fractions. The level of As was consistently greater in the calcium-enriched fraction, while Hg was evenly distributed in all components of LSD ash. Specific surface area was an important factor controlling the distribution of Hg in the different components of LSD ash, but not for As. Comparing the LSD ash data to samples collected from the economizer suggests that As was effectively captured by fly ash at 600{sup o}C, while Hg was not. Leaching tests demonstrated that As and Hg were more stable in the calcium-enriched fraction than in the fly-ash- or carbon-enriched fractions, potentially because of the greater pH of the leachate and subsequently greater stability of small amounts of calcium solids containing trace elements in these fractions. 37 refs., 8 figs., 2 tabs.

  3. Ash formation, deposition, corrosion, and erosion in conventional boilers

    Energy Technology Data Exchange (ETDEWEB)

    Benson, S.A.; Jones, M.L. [Univ. of North Dakota, Grand Forks, ND (United States)

    1995-12-01

    The inorganic components (ash-forming species) associated with coals significantly affect boiler design, efficiency of operation, and lifetimes of boiler parts. During combustion in conventional pulverized fuel boilers, the inorganic components are transformed into inorganic gases, liquids, and solids. This partitioning depends upon the association of the inorganic components in the coal and combustion conditions. The inorganic components are associated as mineral grains and as organically associated elements, and these associations of inorganic components in the fuel directly influence their fate upon combustion. Combustion conditions, such as temperature and atmosphere, influence the volatility and the interaction of inorganic components during combustion and gas cooling, which influences the state and size composition distribution of the particulate and condensed ash species. The intermediate species are transported with the bulk gas flow through the combustion systems, during which time the gases and entrained ash are cooled. Deposition, corrosion, and erosion occur when the ash intermediate species are transported to the heat-transfer surface, react with the surface, accumulate, sinter, and develop strength. Research over the past decade has significantly advanced understanding of ash formation, deposition, corrosion, and erosion mechanisms. Many of the advances in understanding and predicting ash-related issues can be attributed to advanced analytical methods to determine the inorganic composition of fuels and the resulting ash materials. These new analytical techniques have been the key to elucidation of the mechanisms of ash formation and deposition. This information has been used to develop algorithms and computer models to predict the effects of ash on combustion system performance.

  4. The relation between pre-eruptive bubble size distribution, ash particle morphology, and their internal density: Implications to volcanic ash transport and dispersion models

    Science.gov (United States)

    Proussevitch, Alexander

    2014-05-01

    Parameterization of volcanic ash transport and dispersion (VATD) models strongly depends on particle morphology and their internal properties. Shape of ash particles affects terminal fall velocities (TFV) and, mostly, dispersion. Internal density combined with particle size has a very strong impact on TFV and ultimately on the rate of ash cloud thinning and particle sedimentation on the ground. Unlike other parameters, internal particle density cannot be measured directly because of the micron scale sizes of fine ash particles, but we demonstrate that it varies greatly depending on the particle size. Small simple type ash particles (fragments of bubble walls, 5-20 micron size) do not contain whole large magmatic bubbles inside and their internal density is almost the same as that of volcanic glass matrix. On the other side, the larger compound type ash particles (>40 microns for silicic fine ashes) always contain some bubbles or the whole spectra of bubble size distribution (BSD), i.e. bubbles of all sizes, bringing their internal density down as compared to simple ash. So, density of the larger ash particles is a function of the void fraction inside them (magmatic bubbles) which, in turn, is controlled by BSD. Volcanic ash is a product of the fragmentation of magmatic foam formed by pre-eruptive bubble population and characterized by BSD. The latter can now be measured from bubble imprints on ash particle surfaces using stereo-scanning electron microscopy (SSEM) and BubbleMaker software developed at UNH, or using traditional high-resolution X-Ray tomography. In this work we present the mathematical and statistical formulation for this problem connecting internal ash density with particle size and BSD, and demonstrate how the TFV of the ash population is affected by variation of particle density.

  5. 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

  6. 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.

  7. 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.

  8. Ash deposit characterisation in a large-scale municipal waste-to-energy incineration plant

    International Nuclear Information System (INIS)

    The deposition of ash - combustion residues - on superheaters and heat exchanger surfaces reduce their efficiency; this phenomenon was investigated for a large-scale waste-to-energy incineration facility. Over a period of six months, ash samples were collected from the plant, which included the bottom ash and deposits from the superheater, as well as flyash from the convective heat exchanger, the economiser and fabric filters. These were analysed for particle size, unburned carbon, elemental composition and surface morphology. Element partitioning was evident in the different combustion residues, as volatile metals, such as cadmium, antimony and arsenic, were found to be depleted in the bottom ash by the high combustion temperatures (1000+oC) and concentrated/enriched in the fabric filter ash (transferred by evaporation). Non-volatile elements by contrast were distributed equally in all locations (transported by particle entrainment). The heat exchanger deposits and fabric filter ash had elevated levels of alkali metals. 82% of flyash particles from the fabric filter were in the submicron range.

  9. Ashes from oily sewage sludge combustion: chemistry, mineralogy and leaching properties

    Directory of Open Access Journals (Sweden)

    Róbert Polc

    2016-07-01

    Full Text Available In the current paper the chemical and mineralogical properties of bottom ash and fly ash from oily sewage sludge combustion are investigated. The mineralogical composition and the morphology of ashes were determined by X-ray powder diffraction (XRD in combination with scanning electron microscopy with quantitative energy-dispersive X-ray microanalysis (SEM-EDX. In addition, a leaching test results are presented to shed light on the potential toxicity of studied materials and their impact on the environment is discussed. Both of the studied materials are final products of thermal oxidation at industrial sludge incinerator. This facility aims to sanitary disposal of mechanical and biological sludge from industrial wastewater treatment plant. Bottom ash and fly ash are relatively stable solid products with slightly different chemical and mineralogical composition that reflects their different origin – burning condition in furnace vs. flues gas cleaning technology. Leaching tests of both mentioned materials were implemented under laboratory conditions. The aim of the laboratory tests was to determine the possibility of the pollutants release into the environment. The data presented herein support the importance of detailed mineralogical and geochemical study for the better understanding of the leaching tests. The obtained results showed that both of the sewage sludge ash samples exceed the criteria for accepting waste in landfilles established for Slovakia.

  10. Study of thermal-flow processes in ash cooler cooperating with CFB boiler

    Directory of Open Access Journals (Sweden)

    Paweł Regucki

    2016-03-01

    Full Text Available The article presents an example of thermal-flow analysis of the bottom ash cooler cooperating with the circulating fluidized bed boiler. There is presented a mathematical model of series-parallel hydraulic system supplying the ash cooler in cooling water. The numerical calculations indicate an influence of changes of the pipeline geometrical parameters on the cooling water flow rate in the system. Paper discusses the methodology of the studies and presents examples of the results of thermal balance calculations based on the results of measurements. The numerical results of the thermal-flow analysis in comparison with the measurements on the object indicate that the presented approach could be used as a diagnostic tool investigating the technical state of the bottom ash cooler.

  11. 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

  12. 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)  

  13. Thermal treatment and vitrification of boiler ash from a municipal solid waste incinerator.

    Science.gov (United States)

    Yang, Y; Xiao, Y; Voncken, J H L; Wilson, N

    2008-06-15

    Boiler ash generated from municipal solid waste (MSW) incinerators is usually classified as hazardous materials and requires special disposal. In the present study, the boiler ash was characterized for the chemical compositions, morphology and microstructure. The thermal chemical behavior during ash heating was investigated with thermal balance. Vitrification of the ash was conducted at a temperature of 1400 degrees C in order to generate a stable silicate slag, and the formed slag was examined with chemical and mineralogical analyses. The effect of vitrification on the leaching characteristics of various elements in the ash was evaluated with acid leaching. The study shows that the boiler ash as a heterogeneous fine powder contains mainly silicate, carbonate, sulfates, chlorides, and residues of organic materials and heavy metal compounds. At elevated temperatures, the boiler ash goes through the initial moisture removal, volatilization, decomposition, sintering, melting, and slag formation. At 1400 degrees C a thin layer of salt melt and a homogeneous glassy slag was formed. The experimental results indicate that leaching values of the vitrified slag are significantly reduced compared to the original boiler ash, and the vitrification could be an interesting alternative for a safer disposal of the boiler ash. Ash compacting, e.g., pelletizing can reduce volatilization and weight loss by about 50%, and would be a good option for the feed preparation before vitrification. PMID:18077086

  14. The Mineral Transformation of Huainan Coal Ashes in Reducing Atmospheres

    Institute of Scientific and Technical Information of China (English)

    LI Han-xu; Yoshihiko Ninomiya; DONG Zhong-bing; ZHANG Ming-xu

    2006-01-01

    By using the advanced instrumentation of a Computer Controlled Scanning Electron Microscope (CCSEM),X-ray diffraction (XRD) and X-ray fluorescence (XRF), the ash composition and the mineral components of six typical Huainan coals of different origins were studied. The transformation of mineral matter at high temperatures was tracked by XRD in reducing conditions. The quartz phase decreased sharply and the anorthite content tended to increase at first and then decreased with increasing temperatures. The formed mullite phase reached a maximum at 1250 ℃ but showed a tendency of slow decline when the temperature was over 1250 ℃. The mullite formed in the heating process was the main reason of the high ash melting temperature of Huainan coals. Differences in peak intensity of mullite and anorthite reflected differences in phase concentration of the quenched slag fractions, which contributed to the differences in ash melting temperatures. The differences in the location of an amorphous hump maximum indicated differences of glass types which may affect ash melting temperatures. For Huainan coal samples with relatively high ash melting temperatures, the intensity of the diffraction lines for mullite under reducing condition is high while for the samples with relatively low ash melting temperature the intensity for anorthite is high.

  15. 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) ...

  16. 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...

  17. 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...

  18. 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) ...

  19. 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...

  20. 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) ...

  1. 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...

  2. 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...

  3. Investigations of ash fouling with cattle wastes as reburn fuel in a small-scale boiler burner under transient conditions.

    Science.gov (United States)

    Oh, Hyukjin; Annamalai, Kalyan; Sweeten, John M

    2008-04-01

    Fouling behavior under reburn conditions was investigated with cattle wastes (termed as feedlot biomass [FB]) and coal as reburn fuels under a transient condition and short-time operation. A small-scale (30 kW or 100,000 Btu/hr) boiler burner research facility was used for the reburn experiments. The fuels considered for these experiments were natural gas (NG) for the ashless case, pure coal, pure FB, and blends of coal and FB. Two parameters that were used to characterize the ash "fouling" were (1) the overall heat-transfer coefficient (OHTC) when burning NG and solid fuels as reburn fuels, and (2) the combustible loss through ash deposited on the surfaces of heat exchanger tubes and the bottom ash in the ash port. A new methodology is presented for determining ash-fouling behavior under transient conditions. Results on the OHTCs for solid reburn fuels are compared with the OHTCs for NG. It was found that the growth of the layer of ash depositions over longer periods typically lowers OHTC, and the increased concentration of ash in gas phase promotes radiation in high-temperature zones during initial periods while decreasing the heat transfer in low-temperature zones. The ash analyses indicated that the bottom ash in the ash port contained a smaller percentage of combustibles with a higher FB percentage in the fuels, indicating better performance compared with coal because small particles in FB burn faster and the FB has higher volatile matter on a dry ash-free basis promoting more burn out. PMID:18422038

  4. Phenolic acids as bioindicators of fly ash deposit revegetation.

    Science.gov (United States)

    Djurdjević, L; Mitrović, M; Pavlović, P; Gajić, G; Kostić, O

    2006-05-01

    The floristic composition, the abundance, and the cover of pioneer plant species of spontaneously formed plant communities and the content of total phenolics and phenolic acids, as humus constituents, of an ash deposit after 7 years of recultivation were studied. The restoration of both the soil and the vegetation on the ash deposits of the "Nikola Tesla-A" thermoelectric power plant in Obrenovac (Serbia) is an extremely slow process. Unfavorable physical and chemical characteristics, the toxicity of fly ash, and extreme microclimatic conditions prevented the development of compact plant cover. The abundance and cover of plants increased from the central part of the deposit towards its edges (ranging from 1-80%). Festuca rubra L., Crepis setosa Hall., Erigeron canadensis L., Cirsium arvense (L.) Scop., Calamagrostis epigeios (L.) Roth., and Tamarix gallica L. were the most abundant species, thus giving the highest cover. Humus generated during the decomposition process of plant remains represents a completely new product absent in the ash as the starting material. The amount of total phenolics and phenolic acids (38.07-185.16 microg/g of total phenolics and 4.12-27.28 microg/g of phenolic acids) in fly ash increased from the center of the deposit towards its edges in correlation with the increase in plant abundance and cover. Ash samples contained high amounts of ferulic, vanillic, and p-coumaric acid, while the content of both p-hydroxybenzoic and syringic acid was relatively low. The presence of phenolic acids indicates the ongoing process of humus formation in the ash, in which the most abundant pioneer plants of spontaneously formed plant communities play the main role. Phenolic compounds can serve as reliable bioindicators in an assessment of the success of the recultivation process of thermoelectric power plants' ash deposits. PMID:16418890

  5. 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.

  6. On the removal of hexavalent chromium from a Class F fly ash.

    Science.gov (United States)

    Huggins, F E; Rezaee, M; Honaker, R Q; Hower, J C

    2016-05-01

    Coarse and fine samples of a Class F fly ash obtained from commercial combustion of Illinois bituminous coal have been exposed to two long-term leaching tests designed to simulate conditions in waste impoundments. ICP-AES analysis indicated that the coarse and fine fly ash samples contained 135 and 171mg/kg Cr, respectively. Measurements by XAFS spectroscopy showed that the ash samples originally contained 5 and 8% of the chromium, respectively, in the hexavalent oxidation state, Cr(VI). After exposure to water for more than four months, the percentage of chromium as Cr(VI) in the fly-ash decreased significantly for the coarse and fine fly-ash in both tests. Combining the XAFS data with ICP-AES data on the concentration of chromium in the leachates indicated that, after the nineteen-week-long, more aggressive, kinetic test on the coarse fly ash, approximately 60% of the Cr(VI) had been leached, 20% had been reduced to Cr(III) and retained in the ash, and 20% remained as Cr(VI) in the ash. In contrast, during the six-month-long baseline test, very little Cr was actually leached from either the coarse or the fine fly-ash (<0.1mg/kg); rather, about 66% and 20%, respectively, of the original Cr(VI) in the coarse and fine fly-ash was retained in the ash in that form, while the remainder, 34% and 80%, respectively, was reduced and retained in the ash as Cr(III). The results are interpreted as indicating that Cr(VI) present in Class F fly-ash can be reduced to Cr(III) when in contact with water and that such chemical reduction can compete with physical removal of Cr(VI) from the ash by aqueous leaching. PMID:26951722

  7. Reuse of Partially Sulphated CFBC Ash as an SO2 Sorbent

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yinghai; Jia, Lufei; Anthony, E.J. [CanmetENERGY, 1 Haanel Drive, Ottawa, Ontario, K1A1M1 (Canada); Nobili, M.; Telesca, A. [Department of Environmental Engineering and Physics, University of Basilicata, Viale dell' Ateneo, Lucano 10, 85100 Potenza (Italy); Montagnaro, F. [Department of Chemistry, University of Naples ' Federico II' , Monte Sant' Angelo, 80126 Naples (Italy)

    2010-06-15

    Ashes produced from fluidized bed combustors (FBC) burning high-sulphur fuels often contain 20-30 % unreacted CaO because of the limestone added to remove SO2 in situ. This paper presents the results from experiments into reactivating partially sulphated FBC ash (both bed ash and fly ash) with liquid water, steam and sodium carbonate. The water- or steam-hydrated ashes were subsequently re-sulphated in a thermogravimetric analyzer (TGA) with simulated flue gas. The TGA results show that, while liquid water and steam successfully hydrate and reactivate the unreacted CaO in the bed ash, the treated ashes sulphated to widely different extents. Attempts to reactivate fly ash with hydration failed, although fly ash by itself is extremely reactive. A pilot-scale mini-circulating FBC (CFBC) was also used to evaluate the results of reactivation on the bed ash by hydrating with liquid water and admixtures of inorganic salt (Na2CO3) in the form of either powder or solution. When the treated ash was re-injected into the combustor with the fuel, the effect on SO2 removal efficiency was negligible if Na2CO3 was added as powder. Doping with aqueous solution resulted in enhanced SO2 removal; however, the extent was lower than the level achieved if only water hydration was employed. Increasing the amount of water (from 10% to 30%) to reactivate the ash did not improve the sulphur capture capacity in the mini-CFBC. Overall, this study suggests that the most practical way for re-use of the partially sulphated bed ash as a sulphur sorbent is reactivation by water. A proposal for utilization of the fly ash in an economically reasonable way is also discussed.

  8. Decommissioning Peach Bottom Unit 1

    International Nuclear Information System (INIS)

    Decommissioning activities are described for Peach Bottom Unit No. 1, a 40 mw(e) HTGR demonstration plant owned and operated by the Philadelphia Electric Company. Radiological aspects of decommission are discussed. The application of advance planning and effective health physics techniques used during the Peach Bottom decommission program demonstrated the feasibility of decommissioning a nuclear facility economically at low personnel exposure levels and with a negligible environmental impact

  9. 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.

  10. Development of construction materials using coal fly-ash

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Moon Young; Yoo, Jang Han; Lee, Moo Sung [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

    1996-12-01

    The research is intended to find out the possibilities for utility of building materials such as brick with various mixtures of the kaolin and clay. The kaolin belong to the PD, PC and WC grades which from the fly ash of the Honam and the Samcheonpo thermal power plants and clay (HD) from the Hwangdeung, Hadong and Sancheong areas. 1) -200 mesh grain size of fly ash shows higher alkali contents than +200 mesh grains. Especially, alkali components such as CaO (10.58 %), MgO (1.67 %) and Na{sub 2}O (0.53 %) have contributed to make dense structure because of the alkalis are fusion materials. For example, 50 % mixture ratio of fly ash and clay shows the compressional strength of 1,700 kg/cm{sup 2}. The higher mixture ratio of fly ash and clay, the higher compressional intensity is found in general. 2) As the result of the reaction between CaO and Na{sub 2}O compositions in the Honam fly ash, and SiO{sub 2} and Al{sub 2}O{sub 3} in clay at the 1,200 deg. C has shown the formation of plagioclase crystal. 3) Fly ash in the Samcheonpo thermal power plants has lower contents of alkali component than the fly ash in the Honam. If the mixture ratio of fly ash is 10 % the compressional strength is found to be 600-720 kg/cm{sup 2}, that is because of the higher concentrations of uncombustible carbon in the Samcheonpo plant. The compressional intensity decreases as the fly ash contents are increased. When the ratio of mixture in the fly ash is 50 %, the compressional intensity shows 270-300 kg/cm{sup 2}. 4) Mixture experiments among PD, PC and WC grades of kaolin, the sintering has not formed in the grains at the 1,200 deg. C and the compressional strength is rather low with 60{approx}125 kg/cm{sup 2}. At the temperature of sintering is 1250 deg. C the sintering in the grains has been taken place with 210 kg/cm{sup 2}. But the temperature of 1,300 deg. C, the surface of sintering materials shows cracks. 5) The possibilities for usage of fly ash to develop the bricks with various

  11. Durability of incinerator ash waste encapsulated in modified sulfur cement

    International Nuclear Information System (INIS)

    Waste form stability under anticipated disposal conditions is an important consideration for ensuring continued isolation of contaminants from the accessible environment. Modified sulfur cement is a relatively new material and has only recently been applied as a binder for encapsulation of mixed wastes. Little data are available concerning its long-term durability. Therefore, a series of property evaluation tests for both binder and waste-binder combinations have been conducted to examine potential waste form performance under storage and disposal conditions. These tests include compressive strength, biodegradation, radiation stability, water immersion, thermal cycling, and leaching. Waste form compressive strength increased with ash waste loadings to 30.5 MPa at a maximum incinerator ash loading of 43 wt %. Biodegradation testing resulted in no visible microbial growth of either bacteria or fungi. Initial radiation stability testing did not reveal statistically significant deterioration in structural integrity. Results of 90 day water immersion tests were dependent on the type of ash tested. There were no statistically significant changes in compressive strength detected after completion of thermal cycle testing. Radionuclides from ash waste encapsulated in modified sulfur cement leached between 5 and 8 orders of magnitude slower than the leach index criterion established by the Nuclear Regulatory Commission (NRC) for low-level radioactive waste. Modified sulfur cement waste forms containing up to 43 wt % incinerator fly ash passed EPA Toxicity Characteristic Leaching Procedure (TCLP) criteria for lead and cadmium leachability. 11 refs., 2 figs., 5 tabs

  12. 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

  13. Control methods for mitigating biomass ash-related problems in fluidized beds.

    Science.gov (United States)

    Vamvuka, D; Zografos, D; Alevizos, G

    2008-06-01

    Embodiment of biomass combustion technologies in the Cretan energy system will play an important role and will contribute to the local development. The main biomass fuels of Crete are the agricultural residues olive kernel and olive tree wood. Future applications of these biofuels may create, among others, operational problems related to ash effects. In this regard, the thermal behavior of the ashes during lab-scale fluidized bed combustion tests was examined, in terms of slagging/fouling and agglomeration of bed material. Control methodologies for mitigating ash problems were applied, such as leaching the raw fuels with water and using different mineral additives during combustion. The ashes and the bed material were characterized in terms of mineralogical, chemical and morphological analyses and the slagging/fouling and agglomeration propensities were determined. The results showed that fly ashes were rich in Ca, Si and Fe minerals and contained substantial amounts of alkali, falling within the range of "certain or probable slagging/fouling". Leaching of the raw fuels with water resulted in a significant reduction of the problematic elements K, Na, Cl and S in the fly ashes. The use of fuel additives decreased the concentrations of alkali and iron minerals in the fly ashes. With clay additives calcium compounds were enriched in the bottom ash, while with carbonate additives they were enriched in the fly ash. Fuel additives or water leaching reduced the slagging/fouling potential due to alkali. Under the conditions of the combustion tests, no signs of ash deposition or bed agglomeration were noticed. PMID:17826986

  14. 微波灰化电感耦合等离子发射光谱法测定初级形状塑料中催化剂残留%Determination of Residual Catalyst in Primary Forms of Plastics by Microwave Ashing and Inductively Coupled Plasma Optical Emission Spectrometry

    Institute of Scientific and Technical Information of China (English)

    王豪; 张樱; 王夏天; 华正江; 林振兴; 黄通人

    2013-01-01

    采用微波灰化法对聚丙烯(PP)、聚乙烯(PE)和聚对苯二甲酸乙二醇酯(PET)三种初级形状塑料进行灰化,结合差示扫描量热法(DSC)确认微波灰化的温度,并使用电感耦合等离子体发射光谱法(ICP-OES)测定催化剂残留.实验结果表明:塑料经微波灰化梯度升温,在850℃保持30 min可灰化完全.方法对Al、Ca、Co、Cr、Mg、Si、Ti和Zr的检测限分别为0.24、0.12、0.08、0.03、0.03、0.35、0.01、0.02 mg/kg,回收率在92.5%~116.3%之间,相对标准偏差为1.4%~9.7%.%Optimal ashing temperature for three primary forms of plastics' were studied by microwave ashing and differential scanning calorimetry. The residues were dissolved by tartaric acid and hydrochloric acid and were then determined by inductively coupled plasma-optical emission spectrometry. The microwave ashing results showed that the samples of polyethylene,polypropylene and polyethylene terephthalate could be absolutely ashed at 850 C for 30 minutes with a gradient heating. The detection limits of Al,Ca,Co,Cr,Mg,Si,Ti and Zr were 0. 24,0. 12,0. 08,0. 03,0. 03,0. 35,0. 01, 0.02 mg/kg, respectively. The recovery results were in the range of 92. 5%-116. 3% and the relative standard deviation were 1. 4%~9.7%.

  15. Knowledge Transfer from the Forestry Sector to the Agricultural Sector concerning Ash Recycling; Kunskapsoeverfoering fraan skogssektorn till jordbrukssektorn angaaende askaaterfoering

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, Johanna; Salomon, Eva

    2009-02-15

    Cultivation of energy crops on arable land is increasing in Sweden. More than half these crops can be used for combustion, increasing the amount of ash that can be recycled to arable land. Ash is an interesting agricultural fertiliser, but more knowledge is needed before it can be applied and handled in a controlled way. Knowledge and experience concerning recycling of ash within the forest sector can be transferred to the agricultural sector. This project examined ways for ash producers to ensure safe long-term disposal of ash and to improve plant nutrient recycling. The overall aims were to identify experiences and knowledge within forestry that could be applied in agriculture; to identify gaps in knowledge and research requirements regarding ash recycling to arable land; and to produce recommendations on how to increase ash recycling. Literature describing the conditions for ash application to arable land and existing knowledge about ash recycling to forestry were reviewed. Nutrient balances were drawn up for phosphorus, cadmium, zinc and copper, which are relevant in biofuel ash recycling to agriculture. Data on ash application, mainly on forest land, were collected through telephone interviews. For ash to be more attractive for farmers, the ash product must be a realistic alternative to artificial fertilisers. Research and demonstration projects are needed to study the effects of ash on yield and quality in different crops. Different biofuel ash products have differing qualities and can thus have different fields of application within agriculture and can be applied in varying amounts. For example, clean straw ash has a low P and Cd content and mainly supplies potassium and lime. The balance calculations showed that the highest quality ash for arable land is bottom ash from grate combustion of forest trash with 2-5 % of willow. There are both differences and similarities between ash application in agriculture and forestry. An important feature is the

  16. 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.

  17. Composition, diagenetic transformation and alkalinity potential of oil shale ash sediments.

    Science.gov (United States)

    Mõtlep, Riho; Sild, Terje; Puura, Erik; Kirsimäe, Kalle

    2010-12-15

    Oil shale is a primary fuel in the Estonian energy sector. After combustion 45-48% of the oil shale is left over as ash, producing about 5-7 Mt of ash, which is deposited on ash plateaus annually almost without any reuse. This study focuses on oil shale ash plateau sediment mineralogy, its hydration and diagenetic transformations, a study that has not been addressed. Oil shale ash wastes are considered as the biggest pollution sources in Estonia and thus determining the composition and properties of oil shale ash sediment are important to assess its environmental implications and also its possible reusability. A study of fresh ash and drillcore samples from ash plateau sediment was conducted by X-ray diffractometry and scanning electron microscopy. The oil shale is highly calcareous, and the ash that remains after combustion is derived from the decomposition of carbonate minerals. It is rich in lime and anhydrite that are unstable phases under hydrous conditions. These processes and the diagenetic alteration of other phases determine the composition of the plateau sediment. Dominant phases in the ash are hydration and associated transformation products: calcite, ettringite, portlandite and hydrocalumite. The prevailing mineral phases (portlandite, ettringite) cause highly alkaline leachates, pH 12-13. Neutralization of these leachates under natural conditions, by rainwater leaching/neutralization and slow transformation (e.g. carbonation) of the aforementioned unstable phases into more stable forms, takes, at best, hundreds or even hundreds of thousands of years. PMID:20855159

  18. Composition, diagenetic transformation and alkalinity potential of oil shale ash sediments

    International Nuclear Information System (INIS)

    Oil shale is a primary fuel in the Estonian energy sector. After combustion 45-48% of the oil shale is left over as ash, producing about 5-7 Mt of ash, which is deposited on ash plateaus annually almost without any reuse. This study focuses on oil shale ash plateau sediment mineralogy, its hydration and diagenetic transformations, a study that has not been addressed. Oil shale ash wastes are considered as the biggest pollution sources in Estonia and thus determining the composition and properties of oil shale ash sediment are important to assess its environmental implications and also its possible reusability. A study of fresh ash and drillcore samples from ash plateau sediment was conducted by X-ray diffractometry and scanning electron microscopy. The oil shale is highly calcareous, and the ash that remains after combustion is derived from the decomposition of carbonate minerals. It is rich in lime and anhydrite that are unstable phases under hydrous conditions. These processes and the diagenetic alteration of other phases determine the composition of the plateau sediment. Dominant phases in the ash are hydration and associated transformation products: calcite, ettringite, portlandite and hydrocalumite. The prevailing mineral phases (portlandite, ettringite) cause highly alkaline leachates, pH 12-13. Neutralization of these leachates under natural conditions, by rainwater leaching/neutralization and slow transformation (e.g. carbonation) of the aforementioned unstable phases into more stable forms, takes, at best, hundreds or even hundreds of thousands of years.

  19. Measurement of radon exhalation rate from fly ash samples generated in some major thermal power stations

    International Nuclear Information System (INIS)

    Coal-fired thermal power stations account for a majority of the electricity produced in India (about 70%). The coal used in thermal power stations have as high as 35 to 40% ash content resulting in generation of huge quantities of fly ash, a waste product product produced due to the burning of coal. The ever-increasing demand for electricity necessitates the need for the productive utilization of fly ash. One of the areas of major areas of utilization is mixing of fly ash in cement and bricks used for construction of dwellings and office premises. There has been apprehension among the public and environmentalists on the use of fly ash as it contains trace quantities of naturally occurring radioactive materials. Fly ash samples from some of the major thermal power stations across the country were collected and the radon exhalation rates were estimated experimentally using 'can' technique. This technique is a simple and widely-used method for the estimation of exhalation rate measurements. 50 grams fly ash samples were placed in a petri-dish. LR-115 film was affixed at the bottom of the lid of the petri-dish and sealed. Radon gas was allowed to accumulate in the dish for a period of one month, at the end of which the films were retrieved and processed. The radon exhalation rate from the samples analyzed varied between 0.01 and 0.05 Bq kg-1h-1. (author)

  20. Assessing the environmental impact of ashes used in a landfill cover construction.

    Science.gov (United States)

    Travar, I; Lidelöw, S; Andreas, L; Tham, G; Lagerkvist, A

    2009-04-01

    Large amounts of construction materials will be needed in Europe in anticipation for capping landfills that will be closed due to the tightening up of landfill legislation. This study was conducted to assess the potential environmental impacts of using refuse derived fuel (RDF) and municipal solid waste incineration (MSWI) ashes as substitutes for natural materials in landfill cover designs. The leaching of substances from a full-scale landfill cover test area built with different fly and bottom ashes was evaluated based on laboratory tests and field monitoring. The water that drained off above the liner (drainage) and the water that percolated through the liner into the landfill (leachate) were contaminated with Cl(-), nitrogen and several trace elements (e.g., As, Cu, Mo, Ni and Se). The drainage from layers containing ash will probably require pre-treatment before discharge. The leachate quality from the ash cover is expected to have a minor influence on overall landfill leachate quality because the amounts generated from the ash covers were low, <3-30l (m(2)yr)(-1). Geochemical modelling indicated that precipitation of clay minerals and other secondary compounds in the ash liner was possible within 3 years after construction, which could contribute to the retention of trace elements in the liner in the long term. Hence, from an environmental view point, the placement of ashes in layers above the liner is more critical than within the liner. PMID:19081235

  1. Biotoxicity assessment on reusability of municipal solid waste incinerator (MSWI) ash

    International Nuclear Information System (INIS)

    This study provides a first attempt of dose-response analysis and margin of safety using Escherichia coli DH5α, Bacillus subtilis as indicator microorganisms to put forward, in general terms and explanations, the toxicity rankings of various ashes of municipal solid waste incinerator (MSWI) for feasibility in further applications. Since the MSWI ash often contains cations of Si, Ca, Al and Fe, it is frequently considered to be recycled for construction building-materials. Growth inhibition of E. coli DH5α occurred at concentrations over 0.156, 0.625 and 0.0195 g/L for bottom ash (BA), cyclone ash (CA), scrubber ash (SA), respectively, suggesting the toxicity ranking of SA > BA > CA. In contrast, except for SA (ca. 0.313 g/L), almost same inhibitory levels of ashes to cell growth were also observed in Bacillus subtilis. Evidently, biotoxicity responses were strongly dependent upon the characteristics of indicator microorganism. Based on DH5α, the margins of safety (MOS) were thus 0.195, 1.56 and 6.25 mg/L for SA, BA and CA, respectively. Nearly identical levels of MOS were also suggested by B. subtilis, except for SA (3.13 mg/L). Although MSWI residual ashes qualified EPA's standard test of Toxicity Characteristic Leaching Procedure (TCLP), they might still contain other toxic residues (e.g., chloride ions and/or anions) to cause existing toxicity as indicated in this toxicity study

  2. Mercury in the Bottom Sediments of the Water Retention Reservoirs

    OpenAIRE

    Tarnawski M.; Florencka N.; Baran A.

    2013-01-01

    In the environment, mercury undergoes constant changes and gets into soils or waters through atmospheric precipitation. It is quickly sorbed by mineral and organic colloids which occur in water and transported in the form of a suspension or accumulated in bottom sediment. Quality of sediments is an essential indicator of water pollution with this element. The aim of this paper was to an assessment of mercury content in bottom sediments of retention reservoirs in south-eastern Poland. The sedi...

  3. Recent succession of the pedunculate oak and narrow-leaved ash forest in the unflooded part of Gornji Srem

    OpenAIRE

    Tomić Zagorka; Jović Nikola

    2002-01-01

    In the unflooded part of the river Sava, Bosut and Studva bottom lands in Gornji Srem (forest sections Moroviæ and Višnjiæevo), the following succession series are clearly differentiated on large areas: forests of narrow-leaved ash (Fraxinetum angustifoliae Jov. et Tom.1979. s.l) on ((/(-(/(-gley ( forests of pedunculate oak and narrow-leaved ash (Fraxino-Quercetum roboris Jov. et Tom.1979. s.l) on humogley, humosemigley and semigley ( forests of pedunculate oak, hornbeam and ash (Carpino-Fra...

  4. CHARACTERISTICS OF SLUDGE BOTTOM MESH

    Directory of Open Access Journals (Sweden)

    Kamil Szydłowski

    2016-05-01

    Full Text Available The main aim of the study was to assess the selected heavy metals pollution of bottom sediments of small water bodies of different catchment management. Two ponds located in Mostkowo village were chosen for investigation. The first small water reservoir is surrounded by the cereal fields, cultivated without the use of organic and mineral fertilizers (NPK. The second reservoir is located in a park near rural buildings. Sediment samples were collected by the usage of KC Denmark sediments core probe. Samples were taken from 4 layers of sediment, from depth: 0–5, 5–10, 10–20 and 20–30 cm. Sampling was made once during the winter period (2014 year when ice occurred on the surface of small water bodies, from three points. The material was prepared for further analysis according to procedures used in soil science. The content of heavy metals (Cd, Cr, Cu, Ni, Pb and Zn were determined by atomic absorption spectrometry by usage of ASA ICE 3000 Thermo Scientific after prior digestion in the mixture (5: 1 of concentrated acids (HNO3 and HClO4. Higher pH values ​​were characteristic for sediments of pond located in a park than in pond located within the agricultural fields. In both small water bodies the highest heavy metal concentrations occurred in the deepest points of the research. In the sediments of the pond located within crop fields the highest concentration of cadmium, copper, lead and zinc were observed in a layer of 0–5 cm, wherein the nickel and chromium in a layer of 20–30 cm. In the sediments of the pond, located in the park the highest values ​​occurred at the deepest sampling point in the layer taken form 10–20 cm. Sediments from second reservoir were characterized by the largest average concentrations of heavy metals, except the lead content in sediment form the layer of 10–20 cm. According to the geochemical evaluation of sediments proposed by Bojakowska and Sokołowska [1998], the majority of samples belongs to Ist

  5. Energy recovery of metallic aluminium in MSWI bottom ash : Different approaches to hydrogen production from MSWI bottom ash: A case study

    OpenAIRE

    Larsson, Rasmus

    2014-01-01

    Most of the wastes in Sweden end up in incinerator plants. These trashes are full of metals, especially aluminium, which will not oxidize, they can’t always be recycled and they will instead oxidize in water and leak hydrogen gas to its surrounding. Estimations calculate it could be an average potential of around 40-50 kWh/ton of burnt trash. Ignoring the imported trash, the national recovery potential of Sweden’s 4,3 million tonnes of trash would then be equal to 170-220 GWh/year due to non-...

  6. 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...

  7. 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...

  8. 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...

  9. 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 ...

  10. 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) ...

  11. 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...

  12. 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...

  13. 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...

  14. 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) ...

  15. Bottom sediments of Ypacarai Lake

    International Nuclear Information System (INIS)

    Bottom sediments of Ypacarai Lake was investigated with XRF and Mossbauer techniques. The lake of about 120 Km2, is a shallow one, medium deep of about 1.8m. In addition to its use for recreation, its basin has a wide area of influence and of economical significance. Bottom sediments play an important role in the overall distribution of trace elements in the aquatic system and act as a sink for metals. Bottom samples were taken from 5 different sampling stations, selected according to the morphology and population sites in the shore. The concentration of toxic metals was found to be low and no negative ecological impact should be expected. The main metallic ion component is iron (1.69%). Mossbauer studies showed this element appears as Fe+3 and no Fe+2 was detected. It is here suggested that Fe+3 acts as the limiting element which controls eutrophication process

  16. Potential application of coal-fuel oil ash for the manufacture of building materials.

    Science.gov (United States)

    Cioffi, R; Marroccoli, M; Sansone, L; Santoro, L

    2005-09-30

    In this paper coal-fuel oil ash has been characterized in terms of leaching behaviour and reactivity against lime and gypsum in hydratory systems for the manufacture of building materials. Its behaviour was also compared to that of coal ash. Metal release was measured in a dynamic leaching test with duration up to 16 days. The results have shown that coal-fuel oil ash behaves very similarly to coal ash. The reactivity of coal-fuel oil ash against lime and gypsum was measured in mixtures containing only lime and in mixtures containing both lime and gypsum. These systems were hydrated at 25 and 40 degrees C under 100% R.H. The results have shown that the main hydration products are the same as those that are usually formed in similar coal ash-based systems. That is, calcium silicate hydrate in coal-fuel oil ash/lime systems and calcium silicate hydrate plus calcium trisulphoaluminate hydrate in coal-fuel oil ash/lime/gypsum systems. From the quantitative point of view, hydration runs showed that the amounts of both chemically combined water and reacted lime measured in the case under investigation are very similar to those found in similar coal ash-based systems. Finally, the measurement of unconfined compressive strength proved that the systems have potentiality for the manufacture of pre-formed building blocks. PMID:15985327

  17. Chemical and ecotoxicological characterization of ashes obtained from sewage sludge combustion in a fluidised-bed reactor

    International Nuclear Information System (INIS)

    In 1999, the DEECA/INETI and the UBiA/FCT/UNL started a researching project on the partition of heavy metals during the combustion of stabilised sewage sludge (Biogran[reg]), in a fluidised-bed reactor, and on the quality of the bottom ashes and fly ashes produced. This project was entitled Bimetal and was funded by the Portuguese Foundation for Science and Technology. In this paper only the results on the combustion of Biogran[reg]) are reported. The combustion process was performed in two different trials, in which different amounts of sewage sludge and time of combustion were applied. Several ash samples were collected from the bed (bottom ashes) and from two cyclones (first cyclone and second cyclone ashes). Sewage sludge, bed material (sand) and ash samples were submitted to the leaching process defined in the European leaching standard EN 12457-2. The eluates were characterized for a set of inorganic chemical species. The ecotoxicological levels of the eluates were determined for two biological indicators (Vibrio fischeri and Daphnia magna). The results were compared with the limit values of the CEMWE French Regulation. The samples were also ranked according to an index based on the chemical characterization of the eluates. It was observed an increase of the concentration of metals along the combustion system. The ashes trapped in the second cyclone, for both combustion trials, showed the highest concentration of metals in the eluates. Chemically, the ashes of the second cyclone were the most different ones. In the ecotoxicological point of view, the ecotoxicity levels of the eluates of the ashes, for both combustion cycles, did not follow the same pattern as observed for the chemical characterization. The ashes of the first cyclone showed the highest ecotoxicity levels for V. fischeri and D. magna. This difference on chemical and ecotoxicological results proves the need for performing both chemical and ecotoxicological characterizations of the sub

  18. Chemical and ecotoxicological characterization of ashes obtained from sewage sludge combustion in a fluidised-bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lapa, N. [Environmental Biotechnology Researching Unit (UBiA), Faculty of Science and Technology (FCT), New University of Lisbon - UNL, Ed. Departamental, piso 3, gabinete 377, Quinta da Torre, 2829-516 Caparica (Portugal)]. E-mail: ncsn@fct.unl.pt; Barbosa, R. [Environmental Biotechnology Researching Unit (UBiA), Faculty of Science and Technology (FCT), New University of Lisbon - UNL, Ed. Departamental, piso 3, gabinete 377, Quinta da Torre, 2829-516 Caparica (Portugal); Lopes, M.H. [National Institute of Engineering, Technology and Innovation (INETI), Department of Energetic Engineering and Environmental Control (DEECA). Edificio J, Estrada do Paco do Lumiar, 22, 1649-038 Lisbon (Portugal); Mendes, B. [Environmental Biotechnology Researching Unit (UBiA), Faculty of Science and Technology (FCT), New University of Lisbon - UNL, Ed. Departamental, piso 3, gabinete 377, Quinta da Torre, 2829-516 Caparica (Portugal); Abelha, P. [National Institute of Engineering, Technology and Innovation (INETI), Department of Energetic Engineering and Environmental Control (DEECA). Edificio J, Estrada do Paco do Lumiar, 22, 1649-038 Lisbon (Portugal); Gulyurtlu, I. [National Institute of Engineering, Technology and Innovation (INETI), Department of Energetic Engineering and Environmental Control (DEECA). Edificio J, Estrada do Paco do Lumiar, 22, 1649-038 Lisbon (Portugal); Santos Oliveira, J. [Environmental Biotechnology Researching Unit (UBiA), Faculty of Science and Technology (FCT), New University of Lisbon - UNL, Ed. Departamental, piso 3, gabinete 377, Quinta da Torre, 2829-516 Caparica (Portugal)

    2007-08-17

    In 1999, the DEECA/INETI and the UBiA/FCT/UNL started a researching project on the partition of heavy metals during the combustion of stabilised sewage sludge (Biogran[reg]), in a fluidised-bed reactor, and on the quality of the bottom ashes and fly ashes produced. This project was entitled Bimetal and was funded by the Portuguese Foundation for Science and Technology. In this paper only the results on the combustion of Biogran[reg]) are reported. The combustion process was performed in two different trials, in which different amounts of sewage sludge and time of combustion were applied. Several ash samples were collected from the bed (bottom ashes) and from two cyclones (first cyclone and second cyclone ashes). Sewage sludge, bed material (sand) and ash samples were submitted to the leaching process defined in the European leaching standard EN 12457-2. The eluates were characterized for a set of inorganic chemical species. The ecotoxicological levels of the eluates were determined for two biological indicators (Vibrio fischeri and Daphnia magna). The results were compared with the limit values of the CEMWE French Regulation. The samples were also ranked according to an index based on the chemical characterization of the eluates. It was observed an increase of the concentration of metals along the combustion system. The ashes trapped in the second cyclone, for both combustion trials, showed the highest concentration of metals in the eluates. Chemically, the ashes of the second cyclone were the most different ones. In the ecotoxicological point of view, the ecotoxicity levels of the eluates of the ashes, for both combustion cycles, did not follow the same pattern as observed for the chemical characterization. The ashes of the first cyclone showed the highest ecotoxicity levels for V. fischeri and D. magna. This difference on chemical and ecotoxicological results proves the need for performing both chemical and ecotoxicological characterizations of the sub

  19. 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.

  20. 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...

  1. 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

  2. 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.)

  3. 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

  4. Novel incineration technology integrated with drying, pyrolysis, gasification, and combustion of MSW and ashes vitrification.

    Science.gov (United States)

    Liu, Yangsheng; Liu, Yushan

    2005-05-15

    The conventional mass burn systems for municipal solid waste (MSW) emit large amount of acidic gases and dioxins as well as heavy metals due to the large excess air ratio. Additionally, the final process residues, bottom ash with potential leachability of heavy metals and fly ash with high level of heavy metals and dioxins, also constitute a major environmental problem. To deal with these issues more effectively, a novel MSW incineration technology was developed in this study. MSW drying, pyrolysis, gasification, incineration, and ash vitrification were achieved as a spectrum of combustion by the same equipment (primary chamber) in one step. In practice, the primary chamber of this technology actually acted as both gasifier for organic matter and vitrifying reactor for ashes, and the combustion process was mainly completed in the secondary chamber. Experiments were carried outto examine its characteristics in an industrial MSW incineration plant, located in Taiyuan, with a capability of 100 tons per day (TPD). Results showed that (1) the pyrolysis, gasification, and vitrification processes in the primary chamber presented good behaviors resulting in effluent gases with high contents of combustibles (e.g., CO and CH4) and bottom ash with a low loss-on-ignition (L.o.l), low leachability of heavy metals, and low toxicity of cyanide and fluoride. The vitrified bottom ash was benign to its environment and required no further processing for its potential applications. (2) Low stack emissions of dioxins (0.076 ng of TEQ m(-3)), heavy metals (ranging from 0.013 to 0.033 mg m(-3)), and other air pollutants were achieved. This new technology could effectively dispose Chinese MSW with a low calorific value and high water content; additionally, it also had a low capital and operating costs compared with the imported systems. PMID:15952396

  5. Culture from the Bottom Up

    Science.gov (United States)

    Atkinson, Dwight; Sohn, Jija

    2013-01-01

    The culture concept has been severely criticized for its top-down nature in TESOL, leading arguably to its falling out of favor in the field. But what of the fact that people do "live culturally" (Ingold, 1994)? This article describes a case study of culture from the bottom up--culture as understood and enacted by its individual users.…

  6. Results from a full scale application of ashes and other residuals in the final cover construction of the Tveta landfill; Utvaerdering av fullskaleanvaendning av askor och andra restprodukter vid sluttaeckning av Tveta Aatervinningsanlaeggning

    Energy Technology Data Exchange (ETDEWEB)

    Tham, Gustav (Telge AB, Soedertaelje (Sweden)); Andreas, Lale (Luleaa Univ. of Technology, Luleaa (Sweden))

    2008-06-15

    In 2000 Telge Aatervinning - a waste management and recycling company - started investigating ashes from incineration of industrial and biowaste waste. The company was given a permit from the Swedish Environmental Court to cover four hectares of the house hold waste landfill area. In 2006 the company received an unlimited permit to cover the remaining part of the landfill when the works end some thirty years later. Ashes were used the first time in 1966 for testing. Literature studies indicated the ashes can have a low hydraulic conductivity under certain conditions. In 1999 collaboration started with the Division of Waste Science and Technology at Luleaa University of Technology. Residuals from household and industrial waste were subject to investigation. Initially, biowaste incineration products were subject to testing and were later extended to other waste products, e.g. sludge, contaminated soils, foundry, and compost material. Several different sub-fractions of ashes were included in the investigation e.g. bottom and fly ash, various slag products after up-grading including dewatering, separation and sifting. Subsequently, a complete covering system of a landfill consists of residuals. Six test areas were outlined in order to give a good representation for cover construction in flat and steep areas with different compositions of liner material. The results show that in all areas the hydraulic conductivity construction yields less then 50 liters per square meters and years and can be less the than 5 liters in a repository for hazardous waste if required. In accordance with literature data the field observations show the liner material constructed only by ash material under certain conditions can form a monolithic structure due to very slow processes thus indicating small pore volumes that unable water air to interact with other media. The concept of using ash can be related to natural analogues of volcanic ashes and has been used in old defence walls and other

  7. Rare earth element content in various waste ashes and the potential risk to Japanese soils.

    Science.gov (United States)

    Zhang, F S; Yamasaki, S; Kimura, K

    2001-11-01

    Selected chemical characteristics of rare earth elements (REEs) in 89 waste ash samples, including food scrap ashes (FSA), animal waste ashes (AWA), horticulture waste ashes (HWA), sewage sludge ashes (SSA) and incinerator bottom ashes (IBA), were examined in this study. The results showed that Y, La, Ce, Pr, Nd, Dy, Yb, Ho, Er, Tm, Lu in the waste ash samples were normally distributed, but Sc, Sm, Eu, Gd, Tb were not. Average REE concentrations followed the sequence of Ce > La = Y> Sc>Nd>Sm>Pr>Gd>Dy>Eu>Tb>Er> Yb>Ho>Lu>Tm. Of the five types of waste ashes, total REE contents (sigmaREE) ranged from 54 to 130 mg/kg, following the sequence of SSA>HWA>IBA>AWA>FSA; individual REE concentrations were within 0.04-20, 0.1-29, 0.2-33, 0.1-44 and 0.01-41 mg/kg for FSA, AWA, HWA, SSA and IBA, respectively. Crust-normalized REE patterns indicated that SSA was enriched with Sc, Sm, Eu, Gd, Tb and slightly enriched with La, Ce; IBA was enriched with Eu, Tb and slightly with La, Y, Ce; FSA was slightly enriched with Sm, Eu, Tb; REEs were not found to be elevated in HWA and AWA. Comparison of REE content in the waste ashes and in six principal Japanese agricultural soils indicated that application of FSA, AWA and HWA to agricultural land will cause no REE problem, but continuous application of SSA or IBA may cause Sc, Sm or Eu accumulation in some of the soils. PMID:11757853

  8. Hydrolytic stability of heavy metal compounds in fly ash of a heat power plant

    International Nuclear Information System (INIS)

    Ash and slag from solid fuels are utilized widely in building materials and road surfaces, and in agriculture for soil acidulation. For all these uses it is important to know the amount and form of heavy metal compounds contained in ash and their likely behavior when ash and slag wastes are utilized. Studying the behavior of heavy metals in ash residues at contact with water media is important also because, for most trace elements, the authors lack experimental data that would enable us to predict their behavior after prolonged storage and industrial utilization. The present paper describes a study of lixiviation (at various pH in static conditions) of heavy metals form fly ash obtained by burning Azeisk coal. Homogenized ash selected from electric filter sections 1-4 was used, which has the following composition (%): SiO2 59.8; Al2O3; Fe23O3 7.1; CaO 4.1; MgO 1.3; other 2.8. In a neutral medium, Ni, Cu, Zn, Pb, and Mn lixiviation was slight, amounting to 0.01-0.4%. During coal combustion, these elements apparently form compounds that are slightly soluble in water, although it is also possible that ash retains high adsorptivity for heavy metals. As a result, in these conditions the reverse process of sorption of heavy metals from the solution by fly ash is also possible, which would reduce the heavy metal concentration in the solution

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

    Energy Technology Data Exchange (ETDEWEB)

    Skov, S.; Ingerslev, M.

    2011-07-01

    Harvest of forest biomass for energy production may lead to a significant export of nutrients from the forest. Ash spreading and recycling of nutrients from wood chip combustion to the forest has come into focus as a means for counteracting the nutrient export. A study was carried out to examine the retention of various elements in the different ash fractions and utilize the nutrient recovery to evaluate the fertilizer quality of the examined ash. The mass and element flux of wood chips, bottom ash, cyclone fly ash and condensation sludge at Ebeltoft central heating plant was studied over a four-day period in spring 2005. Substantial amounts of nutrients were retained in the fly ash (P, Ca, Mg, Mn and Cu have a recovery higher than 60 % and K, S and Fe have a recovery higher than 30 %). The recovery of elements in the bottom ash was smaller. The added recovery of the usable fractions of ashes (both fly ash and bottom ash) exceeded 75 % for the nutrients P, Ca, Mn and Mg. Both these ash fractions should be considered for fertilization. To examine how ash application affects the forest and Christmas tree stand ecosystem and especially the element budget field experiments were established and monitored intensively. Wood ash is alkaline and by spreading ash in the forest ecosystem, the chemistry of soil water and soil is affected. This introduces a risk of scorching the organisms, eg. mosses but also of root damaging and thereby an impaired water and nutrient uptake as a result. The ash contains salts. Some of these salts, especially metal chlorides and metal sulfates can be dissolved quickly and causes a pH decrease in soil water. There may be a risk that the geochemical conditions in the soil changed dramatically within a relatively short period. These changes can affect nutrient concentrations in soil water and mineralization of organic matter in soil. This increases the risk of leaching and permanent loss of nutrients. These adverse effects of wood ash application

  10. On Mattering: A Coal Ash Flood and the Limits of Environmental Knowledge

    Directory of Open Access Journals (Sweden)

    Hatmaker, Susie

    2014-05-01

    Full Text Available This paper investigates the largest flood of coal ash in United States history as an event at once monumental and insignificant. It traces affective forces generative of both the ash, and its invisibility. In the moment of rupture, the ash flowed out of a large holding pond in a spill of layered sediments – each layer of particulate a temporary resting place for a forceful trajectory of matter spurned into motion elsewhere in space and time. This paper takes up the atemporal matter of this coal ash flood to ask: out of what movements and connections was the ash formed? How did this particular landscape change to accommodate its accumulation? What trajectories flowed into the pond, and what hidden memories sat buried in its mass? Drawing on ethnographic and archival research, this paper weaves together juxtaposed scenes that form (some of the backstory of this event, and invites a reconsideration of the practices of knowledge that helped condition it.

  11. 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)

  12. Ectomycorrhizal community structure and function in relation to forest residue harvesting and wood ash applications

    International Nuclear Information System (INIS)

    Ectomycorrhizal fungi form symbiotic associations with tree roots and assist in nutrient-uptake and -cycling in forest ecosystems, thereby constituting a most significant part of the microbial community. The aims of the studies described in this thesis were to evaluate the potential of DNA-based molecular methods in below-ground ectomycorrhizal community studies and to investigate changes in ectomycorrhizal communities on spruce roots in sites with different N deposition, and in sites subjected to harvesting of forest residues or application of wood ash. The ability of selected ectomycorrhizal fungi to mobilise nutrients from wood ash and to colonise root systems in the presence and absence of ash was also studied. In total 39 ectomycorrhizal species were detected in the experimental forests located in southern Sweden. At each site five to six species colonised around 60% of the root tips. The dominant species, common to the sites, were Tylospora fibrillosa, Thelephora terrestris and Cenococcum geophilum. Differences between two sites with differing levels of N deposition suggested that community structure may be influenced by N deposition, although site history, location and degree of isolation may also influence species composition. Repeated harvesting of forest residues reduced numbers of mycorrhizal roots in the humus layer to approximately 50% of that in control plots but no shift in the ectomycorrhizal community could be detected. At another site, application of granulated wood ash induced a shift in ectomycorrhizal community structure and three ectomycorrhizal fungi ('ash fungi') were found to colonise ash granules. Two 'ash fungi' showed a superior ability to solubilise stabilised wood ash in laboratory experiments compared to other ectomycorrhizal isolates from the same site. In laboratory microcosms containing intact mycorrhizal mycelia, colonisation of wood ash patches by one 'ash fungus' was good whereas colonisation by Piloderma croceum was poor. In a

  13. Heavy Exotic Molecules with Charm and Bottom

    CERN Document Server

    Liu, Yizhuang

    2016-01-01

    We revisit the formation of pion-mediated heavy-light exotic molecules with both charm and bottom and their chiral partners under the general strictures of both heavy-quark and chiral symmetry. The chiral exotic partners with good parity formed using the $(0^+, 1^+)$ multiplet are about twice more bound than their primary exotic partners formed using the $(0^-,1^-)$ multiplet. The chiral couplings across the multiplets $(0^\\pm, 1^\\pm)$ cause the chiral exotic partners to unbind, and the primary exotic molecules to be about twice more bound, for $J\\leq 1$. Our multi-channel coupling results show that only the charm isosinglet exotic molecules with $J^{PC}=1^{++}$ binds, which we identify as the reported neutral $X(3872)$. Also, the bottom isotriplet exotic with $J^{PC}=1^{+-}$ binds, which we identify as a mixture of the reported charged exotics $Z^+_b(10610)$ and $Z^+_b(10650)$. The bound isosinglet with $J^{PC}=1^{++}$ is suggested as a possible neutral $X_b(10532)$ not yet reported.

  14. Washing of fly ash from combustion of municipal solid waste using water as leachant; Vattentvaett av flygaska fraan avfallsfoerbraenning

    Energy Technology Data Exchange (ETDEWEB)

    Steenari, Britt-Marie; Zhao, Dongmei

    2010-03-15

    Ashes from combustion of municipal solid waste contain a large amount of minerals, salts and other metal compounds that are more or less soluble in water. The metal salts are often enriched in the fly ash which leads to a classification of the ash as hazardous waste. This makes ash management complicated and costly. Many stabilisation methods for Municipal Solid Waste Incineration (MSWI) fly ash have been developed and most of them are based on a removal of chloride and sulfate in addition to a binding of metals in less soluble forms. The aim is to avoid the common situation that the ash does not comply to leaching limit values due to release of harmless salts. The aim of this project was to investigate if a simple washing with water can remove enough of the fly ash content of chloride and sulphate so that the ash can be landfilled in a simpler and less costly way than today. The project was focused on fly ashes from the MSWI units owned by Boraas Energi och Miljoe AB and Renova AB Goeteborg, i.e. a electro filter ash from grate fired boilers at Renova and a cyclone ash from a fluid bed boiler at Boraas. The results show that the main part of the chloride content of the ashes can be removed easily, but the washing with water is less effective in the removal of sulphate. A water-to-ash ratio of 1-2 l/kg removes about 100% of chloride but only 8-16% of the sulphate content. In many cases, the leachability of sulphate increases after the washing step. This is due to the rather complex sulphate chemistry with several possible reactions taking place in the ash-water system. For both the tested ashes the high level of chloride leaching is an important factor that prevents admittance on a landfill for hazardous waste without treatment.. The leaching of certain metals, such as Pb, is also high from both ashes but in the case of the Renova fly ash this is dealt with by treatment of the ash according to the Bamberg method. After a water washing with L/S 1-2 (L/kg dry ash

  15. Classification and categorization of treatment methods for ash generated by municipal solid waste incineration: a case for the 2 greater metropolitan regions of Greece.

    Science.gov (United States)

    Karagiannidis, A; Kontogianni, St; Logothetis, D

    2013-02-01

    The primary goal of managing MSW incineration residues is to avoid any impact on human health or the environment. Incineration residues consist of bottom ash, which is generally considered as rather harmless and fly ash which usually contains compounds which are potentially harmful for public health. Small quantities of ash (both bottom and fly) are produced currently in Greece, mainly from the healthcare waste incineration facility in Attica region. Once incineration plants for MSW (currently under planning) are constructed in Greece, the produced ash quantities will increase highly. Thus, it is necessary to organize, already at this stage, a roadmap towards disposal/recovery methods of these ash quantities expected. Certain methods, related to the treatment of the future generated ash which are more appropriate to be implemented in Greece are highlighted in the present paper. The performed analysis offers a waste management approach, having 2016 as a reference year for two different incineration rates; 30% and 100% of the remaining MSW after recycling process. The results focus on the two greater regions of Greece: Attica and Central Macedonia. The quantity of potential future ash generation ranges from 137 to 459 kt for Attica region and from 62 to 207 kt for central Macedonia region depending on the incineration rate applied. Three alternative scenarios for the treatment of each kind of ash are compiled and analysed. Metal recovery and reuse as an aggregate in concrete construction proved to be the most advantageous -in terms of economy-bottom ash management scenario. Concerning management of the fly ash, chemical treatment with phosphoric solution addition results to be the lowest total treatment cost and is considered as the most profitable solution. The proposed methodology constitutes a safe calculation model for operators of MSW incineration plants regardless of the region or country they are located in. PMID:23206519

  16. Composition and leachability of trace elements in coal ash and their migration in ground water at thermal power plant site at Manuguru

    International Nuclear Information System (INIS)

    The Heavy Water Board at Manuguru has a captive power plant using 2500 tpd of coal producing about 1000 tpd of ash. The possible toxic metal contamination of ground water due to leaching of the ash (so that toxic elements do not seep through one pond and contaminate the ground water) are assessed. Samples of coal, fly ash, bottom ash, ash pond overflow water, river water, ash pond slurry, soil (surface and depth) were analysed for major and trace element contents using EDXRF, INAA, AAS, and Anodic Stripping Voltammetry. The cation exchange capacity of the underlying soil and the fly ash were determined by standard method using calcium as the cation indicator. The redox potential and the pH of the samples were measured by using Pt/Mo and glass/calomel system respectively. The size distribution of fly ash particles were also determined. The study conclusively shows that the leach percent being very small and the soil having good cation exchange capacity there is negligible probability of contamination of ground water from ash pond and therefore there is no dire need for providing any impervious lining for the ash pond. (author). 23 refs., 19 tabs., 16 figs., 1 appendix

  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. Physical, chemical and mineralogical characterisation of hydraulically disposed fine coal ash from SASOL Synfuels

    Energy Technology Data Exchange (ETDEWEB)

    Jabulani S. Mahlaba; Elsabe P. Kearsley; Richard A. Kruger [University of Pretoria, Pretoria (South Africa). Civil Engineering

    2011-07-15

    Coal serves as the primary energy source in most parts of the world. It is a fact that coal combustion yields enormous quantities of fly ash some of which are either hydraulically placed or dry dumped. The current study attempts to provide a comprehensive characterisation of a disused alkaline fine coal ash dam (FCAD) towards assessing environmental impact, rehabilitation and utilisation potential. Fine coal ash refers to a combination of approximately 83% power station fly ash and 17% gasification and bottom ash fines (particles {lt}250 {mu}m) at SASOL Synfuels. The hydration products found in Weathered Fine Coal Ash (WFCA) using X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) are analcime, calcite, C-S-H gel, ettringite, hydrated gehlenite (Strtlingite), magnetite, periclase, pyrrhotite and sillimanite. High resolution Scanning Electron Microscope (SEM) results provide additional proof that hydration products are present in WFCA. No indication of appreciable leaching was given by X-ray Fluorescence (XRF) results except calcium and silicon. Thus evidence exists that pollutants from saline brines are immobilised in WFCA and an insight of reaction kinetics was obtained. High content of amorphous phase and lack of alteration in some geotechnical properties suggest that WFCA can be reutilised with lime addition to increase alkalinity and activate pozzolanic reactions. 48 refs., 18 figs., 4 tabs.

  1. Kajian Sifat Mekanik Pada Campuran Aspal Dengan Palm Oil Fly Ash Akibat Beban Tekan Dan Ketahanan Rendam Air

    OpenAIRE

    Nasution, M. Taufik Fadly

    2015-01-01

    Fly ash from the combustion of the boiler in the form of ash with a number that continues to increase throughout the year that are still underutilized. Palm oil fly ash is usually in the form of fine particles whose existence can harm human health if not handled properly. Along with advances in technology, one of the fly ash utilization of palm oil has been used for a mixture of various types of products such as cement, refractory bricks, metal matrix composites and asphalt mixture according ...

  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. Mercury capture by selected Bulgarian fly ashes: Influence of coal rank and fly ash carbon pore structure on capture efficiency

    Science.gov (United States)

    Kostova, I.J.; Hower, J.C.; Mastalerz, Maria; Vassilev, S.V.

    2011-01-01

    Mercury capture by fly ash C was investigated at five lignite- and subbituminous-coal-burning Bulgarian power plants (Republika, Bobov Dol, Maritza East 2, Maritza East 3, and Sliven). Although the C content of the ashes is low, never exceeding 1.6%, the Hg capture on a unit C basis demonstrates that the low-rank-coal-derived fly ash carbons are more efficient in capturing Hg than fly ash carbons from bituminous-fired power plants. While some low-C and low-Hg fly ashes do not reveal any trends of Hg versus C, the 2nd and, in particular, the 3rd electrostatic precipitator (ESP) rows at the Republika power plant do have sufficient fly ash C range and experience flue gas sufficiently cool to capture measurable amounts of Hg. The Republika 3rd ESP row exhibits an increase in Hg with increasing C, as observed in other power plants, for example, in Kentucky power plants burning Appalachian-sourced bituminous coals. Mercury/C decreases with an increase in fly ash C, suggesting that some of the C is isolated from the flue gas stream and does not contribute to Hg capture. Mercury capture increases with an increase in Brunauer-Emmett-Teller (BET) surface area and micropore surface area. The differences in Hg capture between the Bulgarian plants burning low-rank coal and high volatile bituminous-fed Kentucky power plants suggests that the variations in C forms resulting from the combustion of the different ranks also influence the efficiency of Hg capture. ?? 2010 Elsevier Ltd.

  4. Trapping characteristics for gaseous cesium generated from different cesium compounds by fly ash filter

    International Nuclear Information System (INIS)

    The purpose of this study is to evaluate the applicability of the fly ash ceramic foam filter to trap gaseous cesium generated during the OREOX and sintering processes of DUPIC green pellets. The trapping experiments of gaseous cesium generated from different cesium compounds using fly ash filters were carried out in a two-zone furnace under air and hydrogen (Ar/4% H2) conditions. XRD and SEM analyses were used to analyze reaction products of different cesium compounds with fly ash filters. To manufacture ceramic foam filters, fly ash with a Si/Al mole ratio of 2.1 and polyvinyl alcohol as binder were used. Reaction products formed by the trapping reaction of different cesium compounds with fly ash filters were investigated. The major reaction products of gaseous cesium generated from cesium silicate and CsI by fly ash filters indicated that pollucite (CsAlSi2O6) phase was formed under air and hydrogen conditions when the carrier gas velocity was 2 cm/sec. The minimum reaction temperature of fly ash filter with gaseous cesium was determined as about 600 deg. C. Finally, off-gas treatment system of sintering process in a hot cell of lMEF was explained as an application example of fly ash filter for trapping gaseous cesium. (author)

  5. 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.

  6. The utilisation of fly ash in CO2 mineral carbonation

    Directory of Open Access Journals (Sweden)

    Jaschik Jolanta

    2016-03-01

    Full Text Available The fixation of CO2 in the form of inorganic carbonates, also known as mineral carbonation, is an interesting option for the removal of carbon dioxide from various gas streams. The captured CO2 is reacted with metal-oxide bearing materials, usually naturally occurring minerals. The alkaline industrial waste, such as fly ash can also be considered as a source of calcium or magnesium. In the present study the solubility of fly ash from conventional pulverised hard coal fired boilers, with and without desulphurisation products, and fly ash from lignite fluidised bed combustion, generated by Polish power stations was analysed. The principal objective was to assess the potential of fly ash used as a reactant in the process of mineral carbonation. Experiments were done in a 1 dm3 reactor equipped with a heating jacket and a stirrer. The rate of dissolution in water and in acid solutions was measured at various temperatures (20 - 80ºC, waste-to-solvent ratios (1:100 - 1:4 and stirrer speeds (300 - 1100 min-1. Results clearly show that fluidised lignite fly ash has the highest potential for carbonation due to its high content of free CaO and fast kinetics of dissolution, and can be employed in mineral carbonation of CO2.

  7. Municipal solid waste combustor ash demonstration program `the boathouse`

    Energy Technology Data Exchange (ETDEWEB)

    Roethel, F.J.; Breslin, V.T.

    1995-08-01

    The report presents the results of a research program designed to examine the engineering and environmental acceptability of using municipal solid waste (MSW) combustor ash as an aggregate substitute in the manufacture of construction quality cement blocks. 350 tons of MSW combustor ash was combined with Portland and Cement to form standard hollow masonary blocks. These stabilized combustor ash (SCA) blocks were used to construct a boathouse on the campus of the University at Stony Brook. Air samples collected within the boathouse were examined and compared to ambient air samples for the presence and concentrations of suspended particulate, and vapor phase PCDD/PCDF, volatile and semi-volatile organic compounds and volatile mercury. Rainwater samples following contact with the boathouse walls were collected and analyzed for the presence of trace elements. Soil samples were collected prior to and following the construction of the boathouse.

  8. Ash and soil conditioning using exothermic metallic compositions

    International Nuclear Information System (INIS)

    The ash residue obtained after solid radioactive waste incineration is to be conditioned prior to transportation and disposal in order to avoid possible release of radionuclides into the environment. A thermochemical approach to conditioning ash residue that involves the use of exothermic metallic compositions (EMC) has been previously reported. EMC intermixed with ash residue at the appropriate ratios can sustain a glass forming reaction wave that produces monolith glass-like blocks. Herein, the thermochemical conditioning process is extended for conditioning contaminated clay soils. The results are reported for a study of the conditioning process and product materials to determine the optimal processing parameters and to characterize the product materials. Copyright (2001) Material Research Society

  9. Alpha radioactivity study in coal-ash of thermal power plant using solid state nuclear track detector

    International Nuclear Information System (INIS)

    Coal combustion in power plants in India produces large quantities coal related wastes, for example flyash and bottom ash. Coal is known to contain trace quantities of naturally occurring radionuclides including uranium. Thus coal ash is also expected to contain those radionuclides. Flyash has become the subject of worldwide interest because of its diverse uses as in the manufacturing of cement, bricks, blocks, etc. Due to presence of higher concentration of primordial radionuclide content it may cause a potential health risk to people. The power plant- ash, if not properly disposed, will be a serious threat to the ambient environment. So it is essential to investigate the presence of radioactivity in the coal ash samples collected from different thermal power plants. In the present work, an attempt has been made to estimate the alpha activity in the coal ash samples collected from Kolaghat Thermal Power Plant, West Bengal using CR-39 plates - a very useful solid state nuclear track detector (SSNTD). It is one of the largest thermal power generation centres in West Bengal. This thermal power plant uses sub-bituminous coal from the nearby coalfields. The alpha activity of the samples varies from 1052-3571 Bq/kg. The analysis indicates high level of alpha activity in both fly and bottom ash and the level of activity are maximum among all power plant flyash of India reported so far. (author)

  10. Genesis of some tertiary Indian coals from the chemical composition of ash - a statistical approach: Part 1

    Science.gov (United States)

    Sharma, Arpita; Saikia, Ananya; Khare, Puja; Baruah, B. P.

    2014-10-01

    In the present investigation, 37 numbers of high sulphur tertiary coal samples from Meghalaya, India have been studied on the basis of proximate and ash analysis. Various statistical tools like Bivariant Analysis, Principal Component Analysis (PCA) and Hierarchical Clustering Analysis (HCA), and also the geochemical indicators were applied to determine the dominant detrital or authigenic affinity of the ash forming elements in these coals. The genetic interpretation of coal as well as the coal ash has been carried out based on chemical compositions of high temperature ash (HTA) by using Detrital/Authigenic Index. X-Ray Diffraction (XRD) analysis was also carried out to study the mineralogy of the studied coal ashes. Both statistical tools and geochemical indicators have confirmed the detrital nature of these coals as well as the ash forming elements.

  11. Genesis of some tertiary Indian coals from the chemical composition of ash – a statistical approach: Part 1

    Indian Academy of Sciences (India)

    Arpita Sharma; Ananya Saikia; Puja Khare; B P Baruah

    2014-10-01

    In the present investigation, 37 numbers of high sulphur tertiary coal samples from Meghalaya, India have been studied on the basis of proximate and ash analysis. Various statistical tools like Bivariant Analysis, Principal Component Analysis (PCA) and Hierarchical Clustering Analysis (HCA), and also the geochemical indicators were applied to determine the dominant detrital or authigenic affinity of the ash forming elements in these coals. The genetic interpretation of coal as well as the coal ash has been carried out based on chemical compositions of high temperature ash (HTA) by using Detrital/Authigenic Index. X-Ray Diffraction (XRD) analysis was also carried out to study the mineralogy of the studied coal ashes. Both statistical tools and geochemical indicators have confirmed the detrital nature of these coals as well as the ash forming elements.

  12. Accumulation of metals in vegetation established in ash constructions; Ackumulering av metaller i vegetation paa geotekniska askkonstruktioner

    Energy Technology Data Exchange (ETDEWEB)

    Hemstroem, Kristian; Wik, Ola (SGI, Statens geotekniska institut (Sweden)); Bramryd, Torleif; Johansson, Michael (Lunds Universitet, Miljoestrategi (Sweden)); Jaegerbrand, Annika (VTI, Statens Vaeg och transportforskningsinstitut (Sweden))

    2012-02-15

    The overall aim of this study was to investigate how the use of ash in a long-term perspective affects the surrounding flora and fauna with regard to the accumulation of metals in the ecosystem through plant uptake and exposure to grazing animals. The study included a field study and a cultivation experiment. In the field study, the accumulation of metals and metalloids in leaves of trees and shrubs that had self established and grown in lysimeters with aged MSWI bottom ash and aged biofuel ash was determined. In the cultivation experiment, the accumulation of metals and metalloids from the studied materials in ryegrass was determined. Reference materials in the cultivation experiment were two conventional geotechnical materials, crushed rock and excavated soil. Leaves from trees and bushes in the vicinity of the ash lysimeters were used as reference materials in the field study. Contamination of plant samples with particles, through splashing during rain, dusting, or in connection with sampling, proved to have had a major impact on the measured metal and metalloid concentrations in several grass samples in the cultivation experiment. The results also indicate that contamination of plant samples with particles occurred in the field study. In this case, probably due to atmospheric deposition. The particle contamination complicated the evaluation of some of the results in the project since the intention was to study accumulation by roots from the studied ash materials, but, on the other hand, the particle contamination showed the importance of taking into account the spreading of contaminants through particles as an exposure route for grazing animals. In the field study, only Cd and Zn in aspen, willow and birch exhibited elevated levels in the leaves due to root uptake from MSWI bottom ash compared to the reference samples. In addition, elevated levels of As was observed in leaves from trees in the biofuel ash. The total content of As was similar in all studied

  13. Application of zeolitic materials prepared from fly ash to water vapor adsorption for solar cooling

    International Nuclear Information System (INIS)

    Highlights: ► Water vapor isotherms of lignite ash are of type III with low adsorption capacity. ► Mild fly ash hydrothermal treatment produces a hydrophilic zeolitic material. ► The zeolitic material exhibits a type IV water vapor adsorption isotherm. ► Under irradiation, its surface temperature is reduced due to water desorption. ► Potential application of the fly ash zeolitic material for solar cooling. -- Abstract: The water vapor adsorption properties of raw and hydrothermally treated fly ashes with NaOH and their application prospect as evaporative coolers of roof surfaces were studied. Initially, samples were characterized through techniques like elemental analysis, X-ray diffraction, thermogravimetry, reflectance measurements and water vapor adsorption isotherms. Moreover, the water adsorption properties and the associated temperature variations were determined in a specific wind tunnel with controllable environmental conditions. The adsorption isotherms for fly ash were of type III indicating hydrophobic material with low water vapor adsorption. The hydrothermal treatment in an alkaline solution transformed the fly ash in hydrophilic material of type IV. Moreover, the treated samples were capable of lowering their surface temperatures due to water evaporation and the release of the latent heat. The maximum difference of temperature increase under simulated solar irradiation was observed between the treated fly ash and the concrete with values of 5.0, 5.4 and 7.5 °C for the surface, middle and bottom position, respectively. The results indicate that the zeolitic materials prepared from the fly ash samples have a significant potential for solar cooling applications.

  14. 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.

  15. 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.

  16. Hierarchical zeolites from class F coal fly ash

    Science.gov (United States)

    Chitta, Pallavi

    Fly ash, a coal combustion byproduct is classified as types class C and class F. Class C fly ash is traditionally recycled for concrete applications and Class F fly ash often disposed in landfills. Class F poses an environmental hazard due to disposal and leaching of heavy metals into ground water and is important to be recycled in order to mitigate the environmental challenges. A major recycling option is to reuse the fly ash as a low-cost raw material for the production of crystalline zeolites, which serve as catalysts, detergents and adsorbents in the chemical industry. Most of the prior literature of fly ash conversion to zeolites does not focus on creating high zeolite surface area zeolites specifically with hierarchical pore structure, which are very important properties in developing a heterogeneous catalyst for catalysis applications. This research work aids in the development of an economical process for the synthesis of high surface area hierarchical zeolites from class F coal fly ash. In this work, synthesis of zeolites from fly ash using classic hydrothermal treatment approach and fusion pretreatment approach were examined. The fusion pretreatment method led to higher extent of dissolution of silica from quartz and mullite phases, which in turn led to higher surface area and pore size of the zeolite. A qualitative kinetic model developed here attributes the difference in silica content to Si/Al ratio of the beginning fraction of fly ash. At near ambient crystallization temperatures and longer crystallization times, the zeolite formed is a hierarchical faujasite with high surface area of at least 360 m2/g. This work enables the large scale recycling of class F coal fly ash to produce zeolites and mitigate environmental concerns. Design of experiments was used to predict surface area and pore sizes of zeolites - thus obviating the need for intense experimentation. The hierarchical zeolite catalyst supports tested for CO2 conversion, yielded hydrocarbons

  17. Long Wave Dynamics along a Convex Bottom

    CERN Document Server

    Didenkulova, Ira; Soomere, Tarmo

    2008-01-01

    Long linear wave transformation in the basin of varying depth is studied for a case of a convex bottom profile in the framework of one-dimensional shallow water equation. The existence of travelling wave solutions in this geometry and the uniqueness of this wave class is established through construction of a 1:1 transformation of the general 1D wave equation to the analogous wave equation with constant coefficients. The general solution of the Cauchy problem consists of two travelling waves propagating in opposite directions. It is found that generally a zone of a weak current is formed between these two waves. Waves are reflected from the coastline so that their profile is inverted with respect to the calm water surface. Long wave runup on a beach with this profile is studied for sine pulse, KdV soliton and N-wave. Shown is that in certain cases the runup height along the convex profile is considerably larger than for beaches with a linear slope. The analysis of wave reflection from the bottom containing a s...

  18. 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...

  19. 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

  20. 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 ...

  1. 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.

  2. Analog-experiment analysis of ash-deposition monitoring model of boiler economizers in power plants

    Institute of Scientific and Technical Information of China (English)

    CHENG Wei-liang; XIA Guo-dong; XU Shou-chen

    2005-01-01

    Ash deposition is a form of particulate fouling, and appears usually in boiler economizers. The ash deposition increases capital expenditure, energy input and maintenance costs. An analog experiment for monitoring ash deposition was performed from the analogous objective of a 410 t/h boiler economizer to verify the rationality and reliability of the ash-deposition-monitoring model presented in order to increase the security and economy in economizer running. The analog experiment platform is a tube-shell exchanger that conforms well to the conditions of a self-modeling area. The analog flue gas in the shell side is the heated air mixed with ash,and in the tube side the fluid is water heated by the flue gas. The fluid state in the water side and the flue gas side follows the second self-modeling area. A 4-factor-3 level orthogonal table was used to schedule 9 operation conditions of orthogonal experiment, with the 4 factors being heat power, flue gas velocity, ashes grain diameter and adding ashes quantity while the three levels are different values due to different position classes in every factor. The ash deposition thermal resistances is calculated by the model with the measure parameters of temperature and pressure drop. It shows that the values of the ash deposition thermal resistances gradually increase up to a stable state. And the experimental results are reliable by F testing method at α = 0. 001. Therefore, the model can be applied in online monitoring of ash deposition in a boiler economizers in power plants and provides scientific decision on ash deposition prediction and sootblowing.

  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. 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

  5. MANUFACTURING OF ALUMINUM/FLY ASH COMPOSITE WITH LIQUID REACTIVE SINTERING TECHNOLOGY

    Institute of Scientific and Technical Information of China (English)

    X.F. Zhang; D.J. Wang; G. Xie

    2002-01-01

    The Al/fly ash composites are fabricated by liquid reactive sintering P/M process withfly ash particles as intensifying phases. The reactivity and newly formed phases dur-ing liquid sintering process have been analyzed by combing Thermochemical data basecalculation and XRD characterization. The results show that some of constituents infly ash have reacted with liquid aluminum so that the elemental Si, Fe, Ti as well assome amount of intermetallic compounds occur. The properties of aluminum/fly ashcomposites have been improved. With the fraction of fly ash increase, the compositedensity decreases; the hardness and the modulus of the composite increases, and thecomposite wear resistance are significantly increased. The fly ash reinforced compos-ires represent a sort of low cost product with possible widespread applications in theautomotive, small engine, and electromechanical machinery sectors.

  6. Development of Crashworthy Bottom and Side Structures

    DEFF Research Database (Denmark)

    Naar, H.; Kujala, P.; Simonsen, Bo Cerup; Ludolphy, H.

    structures. The first structure is a conventional double bottom. In the second structure (presently protected through a patent) the bottom plating is stiffened with hat-profiles instead of bulb profiles. In the third structure the outer shell is an all-steel sandwich panel. In the fourth structure the bottom...

  7. 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

  8. 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.)

  9. Removal of polycyclic aromatic hydrocarbons from organic solvents by ashes wastes

    International Nuclear Information System (INIS)

    Polycyclic aromatic hydrocarbons (PAHs) can be formed during the refinery processes of crude petroleum. Their removal is of great importance. The same happens with other organic solvents used for the extraction of PAHs (hexane, acetonitrile...), which can be polluted with PAHs. Kinetic and equilibrium batch sorption tests were used to investigate the effect of wood ashes wastes as compared to activated carbon on the sorption of three representative PAHs from n-hexane and acetonitrile. Mussel shell ashes were discarded for batch sorption experiments because they were the only ashes containing PAHs. The equilibrium time was reached at 16 h. Physical sorption caused by the aromatic nature of the compounds was the main mechanism that governed the PAHs removal process. Our investigation revealed that wood ashes obtained at lower temperature (300 deg. C) did not show any PAHs sorption, while ashes obtained at higher temperature (>500 deg. C) have adsorbent sites readily available for the PAH molecules. An increase in the molecular weight of PAHs has a strong effect on sorption wood ashes wastes. As low the wood ashes particle size as high the sorption of PAHs, as a result of differences in adsorbent sites. The performance of wood ash wastes vs. activated carbon to remove 10 PAHs from organic solvents is competitive in price, and a good way for waste disposal.

  10. Activation of fly ashes by the high temperature and high alkalinity in ASR tests

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    High temperature and high alkalinity are typical testing conditions to accelerate the appraisal process of the suppressing effect of fly ashes on alkali silica reaction(ASR),but the reaction mechanism of fly ashes would be quite different under such conditions compared to the normal condition of temperature and alkalinity.To make a reasonable analysis of the suppressing effect of fly ashes,13 types of fly ashes were tested in this paper by both the accelerated mortar bar test method and the 60°C accelerated concrete prism test method.The results showed that the effect of fly ashes would be magnified under the condition of high temperature and high alkalinity.The XRD analysis showed that all the phases of fly ash could react with the hot alkaline solution except for mullite and a small amount of quartz.Fly ash could be significantly activated by the 80°C 1 mol/L NaOH solution,and form mainly C-S-H phase and P type zeolite,but its effect on inhibiting ASR was exaggerated then.According to the mortar strength test and the ASR suppressing test results,C-S-H phase contributed to mortar strength,but its amount did not decide the ASR suppressing effect of fly ash.

  11. Compressive strength and microstructure of carbon nanotubes-fly ash cement composites

    International Nuclear Information System (INIS)

    In this work, carbon nanotubes of 0.5 and 1% by weight were added for the first time in a fly ash cement system to produce carbon nanotubes-fly ash composites in the form of pastes and mortars. Compressive strengths of the composites were then investigated. It was found that the use of carbon nanotubes resulted in higher strength of fly ash mortars. The highest strength obtained for 20% fly ash cement mortars was found at 1% carbon nanotubes where the compressive strength at 28 days was 51.8 MPa. This benefit can clearly be seen in fly ash cement with fly ash of 20% where the importance of the addition of carbon nanotubes means that the relative strength to that of Portland cement became almost 100% at 28 days. In addition, scanning electron micrographs also showed that good interaction between carbon nanotubes and the fly ash cement matrix is seen with carbon nanotubes acting as a filler resulting in a denser microstructure and higher strength when compared to the reference fly ash mix without CNTs.

  12. Removal of polycyclic aromatic hydrocarbons from organic solvents by ashes wastes.

    Science.gov (United States)

    Pérez-Gregorio, M R; García-Falcón, M S; Martínez-Carballo, E; Simal-Gándara, J

    2010-06-15

    Polycyclic aromatic hydrocarbons (PAHs) can be formed during the refinery processes of crude petroleum. Their removal is of great importance. The same happens with other organic solvents used for the extraction of PAHs (hexane, acetonitrile...), which can be polluted with PAHs. Kinetic and equilibrium batch sorption tests were used to investigate the effect of wood ashes wastes as compared to activated carbon on the sorption of three representative PAHs from n-hexane and acetonitrile. Mussel shell ashes were discarded for batch sorption experiments because they were the only ashes containing PAHs. The equilibrium time was reached at 16 h. Physical sorption caused by the aromatic nature of the compounds was the main mechanism that governed the PAHs removal process. Our investigation revealed that wood ashes obtained at lower temperature (300 degrees C) did not show any PAHs sorption, while ashes obtained at higher temperature (>500 degrees C) have adsorbent sites readily available for the PAH molecules. An increase in the molecular weight of PAHs has a strong effect on sorption wood ashes wastes. As low the wood ashes particle size as high the sorption of PAHs, as a result of differences in adsorbent sites. The performance of wood ash wastes vs. activated carbon to remove 10 PAHs from organic solvents is competitive in price, and a good way for waste disposal. PMID:20117882

  13. 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

  14. Distribution and solubility of radionuclides and neutron absorbers in waste forms for disposition of plutonium ash and scraps, excess plutonium, and miscellaneous spent nuclear fuels. 1998 annual progress report

    International Nuclear Information System (INIS)

    'The objective of this research is to gain a fundamental understanding of the distributions and the solubility limits for actinides Pu and U and rare earth neutron absorbers such as Gd and Hf in waste forms. This will be accomplished by systematically studying the local structural environments of these constituents in representative waste forms such as glass, ceramics, and vitreous ceramics. Basic knowledge of these issues will provide a technical and scientific basis that can be used by the US Department of Energy (DOE), Environment Management (EM) Program in developing, evaluating, and selecting waste forms for the safe disposal of Pu, spent nuclear fuel, and other transuranic wastes. The work presented here is a summary of the research activity from November 1997 to May 1998. The elucidation of the correlations between the local structural environments of actinides and rare earth neutron absorbers in waste forms as functions of waste form compositions, and waste form processing conditions will also advance basic material science. The work presented here is a summary of the research activity from November 1997 to May 1998. Currently being studied is the effect of the Pu oxidation state on its solubility in borosilicate-based glasses. When glasses are melted in ambient atmosphere, Pu(IV) has been shown to be the dominant oxidation state as determined by ultraviolet-visible-near infrared spectroscopy (UV-VIS-NIR) and x-ray absorption fine structure (XAFS) techniques. However, no literature data are available for glasses containing Pu predominantly as Pu(III) nor the solubility for Pu(III) in the glass. The results of the study demonstrate that in borosilicate glass, Pu(III) is significantly more soluble than Pu(IV). Using x-ray diffraction analysis the solubility of Pu(III) as oxide was determined to be at least 25 mass% in the reduced glass, while it was no greater than 10 mass% in the same glass under oxidizing conditions (glass melting temperature was 1,400 C

  15. 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

  16. Response of Dent Corn and Sweet Corn to Two Different Forms of Co-situs Application Methods of Controlled Release Fertilizer in Upland Field of a Volcanic Ash Soil

    OpenAIRE

    TIAN, Xiaohong; Saigusa,Masahiko

    2003-01-01

    Polyolefin coated fertilizer as a new type of controlled release fertilizer (CRF) has began to be used in upland crops in Japan due to its high N recovery rate and environmental friendly characteristics under humid climate. The objective of this paper lies in investigating the response and adaptability of dent corn (Zea mays L. var. indentata Sturt.) and sweet corn (Zea mays L. var. saccharata Sturt.) to two forms of co-situs application methods (co-situs band application and co-situs spot ap...

  17. 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.

  18. 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...

  19. A preliminary investigation into the physical and chemical properties of biomass ashes used as aggregate fillers for bituminous mixtures.

    Science.gov (United States)

    Melotti, Roberto; Santagata, Ezio; Bassani, Marco; Salvo, Milena; Rizzo, Stefano

    2013-09-01

    Fly and bottom ashes are the main by-products arising from the combustion of solid biomass. Since the production of energy from this source is increasing, the processing and disposal of the resulting ashes has become an environmental and economic issue. Such ashes are of interest as a construction material because they are composed of very fine particles similar to fillers normally employed in bituminous and cementitious mixtures. This research investigates the potential use of ash from biomass as filler in bituminous mixtures. The morphological, physical and chemical characteristics of 21 different ashes and two traditional fillers (calcium carbonate and "recovered" plant filler) were evaluated and discussed. Leaching tests, performed in order to quantify the release of pollutants, revealed that five ashes do not comply with the Italian environmental re-use limits. Experimental results show a wide range of values for almost all the investigated properties and a low correlation with biomass type in terms of origin and chemical composition. Furthermore, sieving and milling processes were found to improve the properties of the raw material in terms of grading and sample porosity. The effectiveness of these treatments and the low content of organic matter and harmful fines suggest that most of the biomass ashes investigated may be regarded as potential replacements for natural filler in bituminous mixtures. PMID:23790672

  20. Volcanic controls on ash iron solubility: thermodynamic modeling of gas-ash interaction in the hot core of volcanic plumes

    Science.gov (United States)

    Hoshyaripour, G.; Hort, M.; Langmann, B.

    2012-04-01

    Recently it has been shown that volcanic ash can act as a fertilizer for phytoplankton bloom by injecting bio-available iron into the surface ocean. However, it is also well known that iron in volcanic ash at least at its generation point (i.e. magma) is mostly in insoluble form, i.e. not bio-available. Although different volcanic and atmospheric processes are assumed to contribute to the transformation of insoluble iron into soluble salts, the causes of iron mobilization in volcanic ash are poorly constrained. Here we explore the volcanic control on the mobilization of iron in volcanic ash in the hot core of volcanic plumes (T>600° C) based on thermodynamic equilibrium considerations. A conceptual box model is considered for the hot core in which 1000° C magmatic gas, ash and 25° C ambient air are mixed. The initial composition of volcanic gas and ash are parameterized based on three types of tectonic settings (convergent plate, divergent plate, and hot spot) and basaltic to rhyolitic magmas. The effect of the initial oxidation state is also considered by changing the oxygen fugacity. First, magmatic oxides (i.e. SiO2, FeO, MgO etc) are titrated into the magmatic gas at constant temperature and fugacity in order to generate the initial iron carrying minerals. Since the alteration of ash composition is mainly diffusion controlled, we assume that inside the hot core of the volcanic plume the Fe speciation is only affected at or near to the ash surface. Results show that the main initial iron carrying minerals are usually ilmenite and fayalite with some addition of pyhrrotite at reduced conditions in divergent plate and hot spot settings. Then the 1000° C magmatic gas-ash mixture is mixed with the 25° C air (N2 79%, O2 21%) until a temperature of 600° C is reached. Results demonstrate that the hot core functions as an oxidizing reactor for the ash surface transforming the whole Fe2+ minerals to Fe3+ species while being cooled to 600° C. However, in reduced

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Life cycle assessment of resource recovery from municipal solid waste incineration bottom ash

    DEFF Research Database (Denmark)

    Allegrini, Elisa; Vadenbo, Carl; Boldrin, Alessio;

    2015-01-01

    breakeven points beyond which the burdens of the recovery processes outweigh the environmental benefits from valorising metals and mineral aggregates. Experimental data for the quantity and quality of individual material fractions were used as a basis for LCA modelling. For the aggregates, three disposal...... routes were compared: landfilling, road sub-base and aggregate in concrete, while specific leaching data were used as the basis for evaluating toxic impacts. The recovery and recycling of aluminium, ferrous, stainless steel and copper scrap were considered, and the importance of aluminium scrap quality...

  6. LCA of management strategies for RDF incineration and gasification bottom ash based on experimental leaching data

    DEFF Research Database (Denmark)

    Gianfilippo, Martina Di; Costa, Giulia; Pantini, Sara;

    2016-01-01

    .e. global warming and mineral abiotic resource depletion) and toxic impact categories (i.e. human toxicity and ecotoxicity) were assessed. The system boundaries included BA transport from the incineration/gasification plants to the landfills and road construction sites, leaching of potentially toxic metals...... cause adverse environmental impacts, the specific properties of BA, in particular its leaching behavior, should be taken into account. This study focuses on the evaluation of potential environmental impacts associated with two different management options for BA from thermal treatment of Refuse Derived...... Fuel (RDF): landfilling and recycling as a filler for road sub bases. Two types of thermal treatment were considered: incineration and gasification. Potential environmental impacts were evaluated by life-cycle assessment (LCA) using the EASETECH model. Both non-toxicity related impact categories (i...

  7. Pengaruh Penggunaan Bottom Ash Sebagai Pengganti Agregat Halus Dan Semen Terhadap Perilaku Mekanik Beton

    OpenAIRE

    Sitorus, Tito Tulus P.

    2014-01-01

    Bahan material yang paling sering digunakan dalam bidang konstruksi bangunan sipil yaitu pemakaian beton. Hal ini disebabkan oleh bahan dasar yang mudah didapat, memiliki kuat tekan besar, tahan air dan cuaca, dan mudah dibentuk. Seiring dengan semakin pesatnya pembangunan yang dilaksanakan di Indonesia, maka bahan penyusun beton semakin sulit didapat dan terjadi peningkatan harga bahan. Berbagai penelitian telah dilakukan untuk mendapatkan bahan penyusun yang hemat biaya dengan memanfaatkan ...

  8. Leaching from MSWI bottom ash: Evaluation of non-equilibrium in column percolation experiments

    DEFF Research Database (Denmark)

    Hyks, Jiri; Astrup, Thomas; Christensen, Thomas Højlund

    2009-01-01

    applied at liquid-to-solid (L/S) ratios of L/S 2 L/kg and 12 L/kg, respectively. Concentrations of Na, K, Cl-, Ca. Si, SO42-, Al, Cu, Ni, Mo, Ba, Pb, Zn, and dissolved organic carbon (DOC) were monitored throughout the entire leaching period: geochemical modeling was used to identify non......-equilibrium-induced changes in the solubility control. Despite both physical and chemical non-equilibrium, the Columns were found to provide adequate information for readily soluble compounds (i.e., Na, Cl-, and K) and solubility-controlled elements (i.e., Ca, SO42-, Ba, Si, Al, Zn, and Pb). The leaching Of Cu and Ni was...... shown to depend strongly on DOC leaching, which was likely affected by physical non-equilibrium during flow interruptions. Consequently, the leaching of Cu and Ni in the undisturbed Columns Was shown to be by about one order of magnitude lower compared with the interrupted column. The results indicate...

  9. Microstructure and Engineering Properties of Alkali Activated Fly Ash -as an environment friendly alternative to Portland cement

    NARCIS (Netherlands)

    Ma, Y.

    2013-01-01

    Alkali activated fly ash (AAFA), also named “geopolymer”, has emerged as a novel engineering material in the construction industry. This material is normally formed by the reaction between fly ash and aqueous hydroxide or alkali silicate solution. With proper mix design, AAFA can present comparable

  10. Briquetting of charcoal from sugar-cane bagasse fly ash (scbfa) as an alternative fuel.

    Science.gov (United States)

    Teixeira, S R; Pena, A F V; Miguel, A G

    2010-05-01

    Brazil is the largest worldwide producer of alcohol and sugar from sugar-cane and has an extensive alternative program for car fuel which is unique. The objective of this work is to offer one management option of a solid residue produced by this industrial segment. The pressed sugar-cane bagasse is burned to produce steam and electricity by cogeneration. The combustion yields both bottom and fly ashes which contain high amounts of silicon oxide as a major component. Fly ash which contains a high volume (>30% by weight) of charcoal was used in this work. The ash was sieved to separate the thick charcoal from inorganic materials which are concentrated in the thinner fraction. The briquettes were hand pressed using charcoal mixed with a binder (starch) obtained from cassava flour (a tropical root). The results (density, mechanical resistance) obtained with 8% by weight of starch binder are presented here. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used to characterize the ashes and the briquettes. The results show that sugar-cane bagasse fly ash (SCBFA) can be used to produce briquettes with an average density of 1.12gcm(-3) and an average calorific value of 25,551kJ/kg. PMID:20133118

  11. Thermal properties of insulating material prepared from coal fly ash and asphalt

    International Nuclear Information System (INIS)

    Coal power plants are producing ash in enormous quantity as fly ash and bottom ash, whenever coal is combusted. Lakhra Coal Power Plant produces waste of solid fossil fuel and lime stone. Due to the silica, alumina and iron oxide it is good to be used in cement preparation and land filling. In this study a new application is identified, which is more useful and beneficial. This paper presents the results carried out investigating the insulating material prepared from the coal fly ash and asphalt by using the simple unit operations of sizing the materials. At melting temperature of the asphalt sieved fly ash is mixed with it to produce complex heavy sludge. Two samples of different ratios from the rapidly solidifying insulating material were prepared in the molding press at 200 psi pressure. Arm-field heat conduction apparatus HT-l was applied to test its thermal properties. Thermal properties of the material were observed to be heat resistant with mean thermal conductivity at 10 watt 0.8949 w/m-K for Sample No.1 and 0.91886 w/m-K for Sample No.2; whereas the mean thermal resistances calculated were 30.4 I 65m/sup 2/-K/w and 29.6234m/sup 2/-K/w, respectively. The results obtained during this study are satisfactory and we hope that the insulation material prepared would be used in Pakistan in building constructions for heat resistance and insulation purposes. (author)

  12. Environmental & Health Hazards of Fly Ash & SOx from FBC Power Plant at Khanote

    Directory of Open Access Journals (Sweden)

    Shaheen Aziz

    2010-12-01

    Full Text Available Lakhra coal reserves are estimated to about 1328 million tones. Most of mined Coal in Pakistan has been used for power generation in addition to some other uses. Lakhra coal (lignite reserves are very high in sulphur content, moisture and ash that not only cause environmental pollution but also cause operational problems. In order to avoid environmental & operational problems, clean coal technology (FBC technology has been used globally because of its merits. In FBC power plant, sulphure is captured by using limestone. In Pakistan, 3x50MW power plant was installed at Khanote to utilize the lakhra coal for the first time. The present study is focused on formation of ash & sulphur. In the FBC power plant at khanote, the generation rate of fly ash & bottom ash was 55680 m3/hr and 16550 m3/hr respectively. Unexpected huge amount of ash causes environmental problem in shape of particulate matter that causes respiratory diseases in the workers. It also affects nearby villages by polluting agricultural land, cattles & habitants. The present research not only indentifies the risks on the basis of extensive experimental analysis, but also proposed solution for its proper disposal.

  13. Electrodialytic Separation of Phosphorus and Heavy Metals from Two Types of Sewage Sludge Ash

    DEFF Research Database (Denmark)

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

    2014-01-01

    During sewage sludge incineration phosphorus (P) is retained in the ash in a form not directly available to plants. As P is a sparse resource, it is important to develop techniques for recovery of P from incinerated sewage sludge ashes (ISSA). Heavy metals are concentrated in ISSA and separation of...... P and h