Quantitative trace element analysis of individual fly ash particles by means of X-ray microfluorescence

Energy Technology Data Exchange (ETDEWEB)

Vincze, L.; Somogyi, A.; Osan, J.; Vekemans, B.; Torok, S.; Janssens, K.; Adams, F. [Universitaire of Instelling Antwerp, Wilrijk (Belgium). Dept. of Chemistry

2002-07-01

A new quantification procedure was developed for the evaluation of X-ray microfluorescence (XRF) data sets obtained from individual particles, based on iterative Monte Carlo (MC) simulation. Combined with the high sensitivity of synchrotron radiation-induced XRF spectroscopy, the method was used to obtain quantitative information down to trace-level concentrations from micrometer-sized particulate matter. The detailed XRF simulation model was validated by comparison of calculated and experimental XRF spectra obtained for glass microsphere standards, resulting in uncertainties in the range of 3-10% for the calculated elemental sensitivities. The simulation model was applied for the quantitative analysis of X-ray tube and synchrotron radiation-induced scanning micro-XRF spectra of individual coal and wood fly ash particles originating from different Hungarian power plants. By measuring the same particles by both methods the major, minor, and trace element compositions of the particles were determined. The uncertainty of the MC based quantitative analysis scheme is estimated to be in the range of 5-30%.

Growth and elemental content of two tree species growing on abandoned coal fly ash basins

International Nuclear Information System (INIS)

Carlson, C.L.; Adriano, D.C.

1991-01-01

Differences in aboveground tissue concentrations of trace elements were assessed for sweetgum (Liquidambar styraciflua L.) and sycamore (Plantanus occidentalis L.) growing on two abandoned coal fly ash basins and a control soil. The wet basin (pH = 5.58) had originally received precipitator ash in an ash-water slurry, while the dry basin (pH = 8.26) had received both precipitator and bottom ash in dry form. In general, trees from the wet basin exhibited elevated trace element concentrations in comparison to the controls, while the dry basin trees exhibited reduced concentrations. On eof the most striking differenced in elemental concentrations among the ash basin and control trees was observed for Mn, with the control trees exhibiting concentrations orders of magnitude greater than the ash basin trees. Differences in foliar trace element concentrations among the sites can generally be explained by differences in substrate trace element concentrations and/or substrate pH. While trees from the wet ash basin generally had the highest trace element concentrations, these trees also attained the greatest height and diameter growth, suggesting that the elevated trace element concentrations in the wet basin substrate are not limiting the establishment of these two species. The greater height and diameter growth of the wet basin trees is presumably a result of the greater water-holding capacity of the substrate on this site. Differences in growth and tissue concentrations between sweetgum and sycamore highlight the importance of using more than one species when assessing metal toxicity or deficiency on a given substrate

Trace elements in coal ash

Science.gov (United States)

Deonarine, Amrika; Kolker, Allan; Doughten, Michael W.

2015-01-01

Coal ash is a residual waste product primarily produced by coal combustion for electric power generation. Coal ash includes fly ash, bottom ash, and flue-gas desulfurization products (at powerplants equipped with flue-gas desulfurization systems). Fly ash, the most common form of coal ash, is used in a range of products, especially construction materials. A new Environmental Protection Agency ruling upholds designation of coal ash as a non-hazardous waste under Subtitle D of the Resource Conservation and Recovery Act, allowing for the continued beneficial use of coal ash and also designating procedures and requirements for its storage.

Size distribution of rare earth elements in coal ash

Science.gov (United States)

Scott, Clinton T.; Deonarine, Amrika; Kolker, Allan; Adams, Monique; Holland, James F.

2015-01-01

Rare earth elements (REEs) are utilized in various applications that are vital to the automotive, petrochemical, medical, and information technology industries. As world demand for REEs increases, critical shortages are expected. Due to the retention of REEs during coal combustion, coal fly ash is increasingly considered a potential resource. Previous studies have demonstrated that coal fly ash is variably enriched in REEs relative to feed coal (e.g, Seredin and Dai, 2012) and that enrichment increases with decreasing size fractions (Blissett et al., 2014). In order to further explore the REE resource potential of coal ash, and determine the partitioning behavior of REE as a function of grain size, we studied whole coal and fly ash size-fractions collected from three U.S commercial-scale coal-fired generating stations burning Appalachian or Powder River Basin coal. Whole fly ash was separated into , 5 um, to 5 to 10 um and 10 to 100 um particle size fractions by mechanical shaking using trace-metal clean procedures. In these samples REE enrichments in whole fly ash ranges 5.6 to 18.5 times that of feedcoals. Partitioning results for size separates relative to whole coal and whole fly ash will also be reported. 

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 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 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...

Trace elements in Turkish tobacco determined by instrumental neutron activation analysis

International Nuclear Information System (INIS)

Guelovali, M.C.; Guenduez, G.

1983-01-01

The concentration of 20 trace elements in nine brands of Turkish cigarette tobacco and in a brand of pipe tobacco ash has been determined by instrumental neutron activation analysis. The percent transference of elements into smoke has been estimated from the amounts remaining in the ash. (author)

Distribution and leaching characteristics of trace elements in ashes as a function of different waste fuels and incineration technologies.

Science.gov (United States)

Saqib, Naeem; Bäckström, Mattias

2015-10-01

Impact of waste fuels (virgin/waste wood, mixed biofuel (peat, bark, wood chips) industrial, household, mixed waste fuel) and incineration technologies on partitioning and leaching behavior of trace elements has been investigated. Study included 4 grate fired and 9 fluidized boilers. Results showed that mixed waste incineration mostly caused increased transfer of trace elements to fly ash; particularly Pb/Zn. Waste wood incineration showed higher transfer of Cr, As and Zn to fly ash as compared to virgin wood. The possible reasons could be high input of trace element in waste fuel/change in volatilization behavior due to addition of certain waste fractions. The concentration of Cd and Zn increased in fly ash with incineration temperature. Total concentration in ashes decreased in order of Zn>Cu>Pb>Cr>Sb>As>Mo. The concentration levels of trace elements were mostly higher in fluidized boilers fly ashes as compared to grate boilers (especially for biofuel incineration). It might be attributed to high combustion efficiency due to pre-treatment of waste in fluidized boilers. Leaching results indicated that water soluble forms of elements in ashes were low with few exceptions. Concentration levels in ash and ash matrix properties (association of elements on ash particles) are crucial parameters affecting leaching. Leached amounts of Pb, Zn and Cr in >50% of fly ashes exceeded regulatory limit for disposal. 87% of chlorine in fly ashes washed out with water at the liquid to solid ratio 10 indicating excessive presence of alkali metal chlorides/alkaline earths. Copyright © 2015. Published by Elsevier B.V.

Distributional Fate of Elements during the Synthesis of Zeolites from South African Coal Fly Ash

Directory of Open Access Journals (Sweden)

Pieter W. Du Plessis

2014-04-01

Full Text Available The synthesis of zeolites from South African coal fly ash has been deemed a viable solution to the growing economical strain caused by the disposal of ash in the country. Two synthesis routes have been studied thus far namely the 2-step method and the fusion assisted process. Fly ash contains several elements originating from coal which is incorporated in the ash during combustion. It is vital to determine the final destination of these elements in order to unveil optimization opportunities for scale-up purposes. The aim of this study was to perform a material balance study on both synthesis routes to determine the distributional fate of these elements during the synthesis of zeolites. Zeolites were first synthesized by means of the two synthesis routes. The composition of all raw materials and products were determined after which an overall and elemental balance were performed. Results indicated that in the 2-step method almost all elements were concentrated in the solid zeolite product while during the fusion assisted route the elements mostly report to the solid waste. Toxic elements such as Pb, Hg, Al, As and Nb were found in both the supernatant waste and washing water resulting from each synthesis route. It has also been seen that large quantities of Si and Al are wasted in the supernatant waste. It is highly recommended that the opportunity to recycle this liquid waste be investigated for scale-up purposes. Results also indicate that efficiency whereby Si and Al are extracted from fused ash is exceptionally poor and should be optimized.

Mapping ash properties using principal components analysis

Science.gov (United States)

Pereira, Paulo; Brevik, Eric; Cerda, Artemi; Ubeda, Xavier; Novara, Agata; Francos, Marcos; Rodrigo-Comino, Jesus; Bogunovic, Igor; Khaledian, Yones

2017-04-01

In post-fire environments ash has important benefits for soils, such as protection and source of nutrients, crucial for vegetation recuperation (Jordan et al., 2016; Pereira et al., 2015a; 2016a,b). The thickness and distribution of ash are fundamental aspects for soil protection (Cerdà and Doerr, 2008; Pereira et al., 2015b) and the severity at which was produced is important for the type and amount of elements that is released in soil solution (Bodi et al., 2014). Ash is very mobile material, and it is important were it will be deposited. Until the first rainfalls are is very mobile. After it, bind in the soil surface and is harder to erode. Mapping ash properties in the immediate period after fire is complex, since it is constantly moving (Pereira et al., 2015b). However, is an important task, since according the amount and type of ash produced we can identify the degree of soil protection and the nutrients that will be dissolved. The objective of this work is to apply to map ash properties (CaCO3, pH, and select extractable elements) using a principal component analysis (PCA) in the immediate period after the fire. Four days after the fire we established a grid in a 9x27 m area and took ash samples every 3 meters for a total of 40 sampling points (Pereira et al., 2017). The PCA identified 5 different factors. Factor 1 identified high loadings in electrical conductivity, calcium, and magnesium and negative with aluminum and iron, while Factor 3 had high positive loadings in total phosphorous and silica. Factor 3 showed high positive loadings in sodium and potassium, factor 4 high negative loadings in CaCO3 and pH, and factor 5 high loadings in sodium and potassium. The experimental variograms of the extracted factors showed that the Gaussian model was the most precise to model factor 1, the linear to model factor 2 and the wave hole effect to model factor 3, 4 and 5. The maps produced confirm the patternd observed in the experimental variograms. Factor 1 and 2

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

Elemental composition of coal fly ash: Malta coal power station in the Mpumalanga province in South Africa case study using nuclear and related analytical techniques

International Nuclear Information System (INIS)

Eze, Ch.P.; Fatoba, O.; Madzivire, G.; Petrik, L.F.; Ostrovnaya, T.M.; Frontas'eva, M.V.; Nechaev, A.N.

2013-01-01

Epithermal neutron activation analysis along with ICP-OES, LA ICP-MS, and XRF were used to determine the elemental composition of coal fly ash from the Malta coal power station in the Mpumalanga province of South Africa. A total of 54 major, trace and rare-earth elements were obtained by the four analytical techniques. The results were compared and the discrepancies discussed to show the merits and drawbacks of each of the techniques. It was shown that the elemental content of this particular coal fly ash is of the same order as the NIST standard reference material Coal Fly Ash 1633b

Combustion of Biosolids in a Bubbling Fluidized Bed, Part 1: Main Ash-Forming Elements and Ash Distribution with a Focus on Phosphorus.

Science.gov (United States)

Skoglund, Nils; Grimm, Alejandro; Ohman, Marcus; Boström, Dan

2014-02-20

This is the first in a series of three papers describing combustion of biosolids in a 5-kW bubbling fluidized bed, the ash chemistry, and possible application of the ash produced as a fertilizing agent. This part of the study aims to clarify whether the distribution of main ash forming elements from biosolids can be changed by modifying the fuel matrix, the crystalline compounds of which can be identified in the raw materials and what role the total composition may play for which compounds are formed during combustion. The biosolids were subjected to low-temperature ashing to investigate which crystalline compounds that were present in the raw materials. Combustion experiments of two different types of biosolids were conducted in a 5-kW benchscale bubbling fluidized bed at two different bed temperatures and with two different additives. The additives were chosen to investigate whether the addition of alkali (K 2 CO 3 ) and alkaline-earth metal (CaCO 3 ) would affect the speciation of phosphorus, so the molar ratios targeted in modified fuels were P:K = 1:1 and P:K:Ca = 1:1:1, respectively. After combustion the ash fractions were collected, the ash distribution was determined and the ash fractions were analyzed with regards to elemental composition (ICP-AES and SEM-EDS) and part of the bed ash was also analyzed qualitatively using XRD. There was no evidence of zeolites in the unmodified fuels, based on low-temperature ashing. During combustion, the biosolid pellets formed large bed ash particles, ash pellets, which contained most of the total ash content (54%-95% (w/w)). This ash fraction contained most of the phosphorus found in the ash and the only phosphate that was identified was a whitlockite, Ca 9 (K,Mg,Fe)(PO 4 ) 7 , for all fuels and fuel mixtures. With the addition of potassium, cristobalite (SiO 2 ) could no longer be identified via X-ray diffraction (XRD) in the bed ash particles and leucite (KAlSi 2 O 6 ) was formed. Most of the alkaline-earth metals

Speciation of major and selected trace elements in IGCC fly ash

Energy Technology Data Exchange (ETDEWEB)

Oriol Font; Xavier Querol; Frank E. Huggins; Jose M. Chimenos; Ana I. Fernandez; Silvia Burgos; Francisco Garcia Pena [Institute of Earth Sciences ' Jaume Almera' , Barcelona (Spain)

2005-08-01

The speciation of Ga, Ge, Ni, V, S and Fe in fly ash from IGCC power plant were investigated for possible further extraction process by combining conventional mineral and chemical analysis, leaching tests, wet sequential extraction, Moessbauer and XAFS spectroscopies. The results shown that Ge occurs mainly as water-soluble species, GeS and/or GeS{sub 2} and hexagonal GeO{sub 2}. Ga is present as an oxide, Ni occurs mainly as nickeline (NiAs), with minor proportions of Ni arsenates and vanadium as V(III) with minor amounts of V(IV) in the aluminosilicate glass matrix. Pyrrhotite and wurtzite-sphalerite are sulfide species containing Fe and Zn, but an important fraction of iron is also present in the aluminosilicate glass. These clear differences between the speciation of the above elements in this material and those reported for fly ash from conventional PC combustion. 15 refs., 8 figs., 5 tabs.

Trace elements in Turkish tobacco determined by instrumental neutron activation analysis

International Nuclear Information System (INIS)

Gulovali, M.C.

1977-01-01

This study was undertaken to determine the concentration of trace elements in nine different brands of Turkish cigarette tobacco, pipe tobacco and tobacco ash. Instrumental neutron activation analysis was employed, and a gamma-ray spectrometer consisting of 40 cm 3 Ge(Li) detector coupled to 1024 and 4096-channel analyzers were used. Samples were irradiated at a thermal neutron flux of about 10 13 cm -2 sec -1 . Concentrations of Na, K, Sc, Cr, Fe, Co, Zn, As, Se, Br, Rb, Sb, Cs, Ba, La, Ce, Eu, Hf, Hg and Th were determined in tobacco and ash; percent transference of these elements into ash were calculated. It was found out that trace elements in cigarette tobacco are left in the ash but only a small percentage is transferred into the smoke

Study of the correlation between the coal calorific value and coal ash content using X-ray fluorescence analysis

International Nuclear Information System (INIS)

Bolortuya, D.; Zuzaan, P.; Gustova, M.V.; Maslov, O.D.

2013-01-01

In this paper we have studied the possibility of determining the chemical elements in coal samples using X-ray fluorescence analysis and have found a relationship between the coal calorific value and its ash content with the coal moisture accounting. The amount of coal ash can be determined by the content of the basic chemical elements, such as Si, Sr, Fe, and Ca. It was concluded that the calorific value of coal can be estimated from the ash content in coal without the calorimetric measurements. These correlation coefficients were calculated for several coal mines in Mongolia. The results are in good agreement with the results of chemical analysis

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

Energy Technology Data Exchange (ETDEWEB)

Funari, Valerio, E-mail: valerio.funari@unibo.it [Dipartimento di Scienze Biologiche, Geologiche e Ambientali (BiGeA)—University of Bologna, Piazza di Porta San Donato 1, Bologna (Italy); Bokhari, Syed Nadeem Hussain [General and Analytical Chemistry—Montanuniversität Leoben, Franz-Josef-Str. 18, Leoben (Austria); Vigliotti, Luigi [Istituto di Scienze Marine (ISMAR-CNR)—National Research Council, Via Piero Gobetti 101, Bologna (Italy); Meisel, Thomas [General and Analytical Chemistry—Montanuniversität Leoben, Franz-Josef-Str. 18, Leoben (Austria); Braga, Roberto [Dipartimento di Scienze Biologiche, Geologiche e Ambientali (BiGeA)—University of Bologna, Piazza di Porta San Donato 1, Bologna (Italy)

2016-01-15

Highlights: • The REE concentrations of bottom and fly ashes from municipal incinerators are investigated. • First attempt toward discriminating the magnetic signature (susceptibility) of ashes from incinerators. • New methods and parameters for REE prospecting, which can be determined quickly and with limited costs, are provided. - Abstract: 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.

Trends in the Rare Earth Element Content of U.S.-Based Coal Combustion Fly Ashes.

Science.gov (United States)

Taggart, Ross K; Hower, James C; Dwyer, Gary S; Hsu-Kim, Heileen

2016-06-07

Rare earth elements (REEs) are critical and strategic materials in the defense, energy, electronics, and automotive industries. The reclamation of REEs from coal combustion fly ash has been proposed as a way to supplement REE mining. However, the typical REE contents in coal fly ash, particularly in the United States, have not been comprehensively documented or compared among the major types of coal feedstocks that determine fly ash composition. The objective of this study was to characterize a broad selection of U.S. fly ashes of varied geological origin in order to rank their potential for REE recovery. The total and nitric acid-extractable REE content for more than 100 ash samples were correlated with characteristics such as the major element content and coal basin to elucidate trends in REE enrichment. Average total REE content (defined as the sum of the lanthanides, yttrium, and scandium) for ashes derived from Appalachian sources was 591 mg kg(-1) and significantly greater than in ashes from Illinois and Powder River basin coals (403 and 337 mg kg(-1), respectively). The fraction of critical REEs (Nd, Eu, Tb, Dy, Y, and Er) in the fly ashes was 34-38% of the total and considerably higher than in conventional ores (typically less than 15%). Powder River Basin ashes had the highest extractable REE content, with 70% of the total REE recovered by heated nitric acid digestion. This is likely due to the higher calcium content of Powder River Basin ashes, which enhances their solubility in nitric acid. Sc, Nd, and Dy were the major contributors to the total REE value in fly ash, based on their contents and recent market prices. Overall, this study shows that coal fly ash production could provide a substantial domestic supply of REEs, but the feasibility of recovery depends on the development of extraction technologies that could be tailored to the major mineral content and origins of the feed coal for the ash.

Major and trace elements in coal bottom ash at different oxy coal combustion conditions

CSIR Research Space (South Africa)

Oboirien, BO

2014-09-01

Full Text Available This paper presents a detailed study on the effect of temperature on the concentration of 27 major and trace elements in bottom ash generated from oxy fuel-combustion. The major elements are Na, Mg, Al, K, Ca and Fe and the minor and trace elements...

Coal fly ash basins as an attractive nuisance to birds: Parental provisioning exposes nestlings to harmful trace elements

International Nuclear Information System (INIS)

Bryan, A.L.; Hopkins, W.A.; Parikh, J.H.; Jackson, B.P.; Unrine, J.M.

2012-01-01

Birds attracted to nest around coal ash settling basins may expose their young to contaminants by provisioning them with contaminated food. Diet and tissues of Common Grackle (Quiscalus quiscala) nestlings were analyzed for trace elements to determine if nestlings were accumulating elements via dietary exposure and if feather growth limits elemental accumulation in other tissues. Arsenic, cadmium, and selenium concentrations in ash basin diets were 5× higher than reference diets. Arsenic, cadmium, and selenium concentrations were elevated in feather, liver, and carcass, but only liver Se concentrations approached levels of concern. Approximately 15% of the total body burden of Se, As, and Cd was sequestered in feathers of older (>5 days) nestlings, whereas only 1% of the total body burden of Sr was sequestered in feathers. Feather concentrations of only three elements (As, Se, and Sr) were correlated with liver concentrations, indicating their value as non-lethal indicators of exposure. - Highlights: ► We examined elemental uptake by grackle nestlings associated with coal ash basins. ► Diet of ash basin nestlings had higher levels of Se, As, and Cd than control nestlings. ► Se, As, Cd, and Sr concentrations of ash basin nestling tissues were elevated. ► Only Se in nestling liver approached published levels of concern. ► Nestling feathers sequestered >15% of the total body burden of Se, As, and Cd. - Nestlings of common grackles attracted to nest around coal ash settling basins were exposed to elevated dietary Se, As, Cd, and Sr, resulting in elevated Se tissue concentrations approaching reported levels of concern.

The effect of ash elements in petroleum coke on hearth furnace heat recovery system performance

Energy Technology Data Exchange (ETDEWEB)

Akhmetov, M M

1981-01-01

Difficulties encountered in the operation of the heat recovery system of a calcination plant at Krasnovodsk Refinery caused by ash element deposits blocking the fire box are described. Deposits and coke ash composition are given. The main cause of blocking was found to be the removal of sea water salt elements which get on the coke surface when the retarded coking plant is discharged with a water-jet borer. Switching over to fresh water and air-blasting of heat recovery pipes decreased blocking considerably.

Speciation analysis of antimony in extracts of size-classified volcanic ash by HPLC-ICP-MS.

Science.gov (United States)

Miravet, R; López-Sánchez, J F; Rubio, R; Smichowski, P; Polla, G

2007-03-01

Although there is concern about the presence of toxic elements and their species in environmental matrices, for example water, sediment, and soil, speciation analysis of volcanic ash has received little attention. Antimony, in particular, an emerging element of environmental concern, has been less studied than other potentially toxic trace elements. In this context, a study was undertaken to assess the presence of inorganic Sb species in ash emitted from the Copahue volcano (Argentina). Antimony species were extracted from size-classified volcanic ash (<36 microm, 35-45 microm, 45-150 microm, and 150-300 microm) by use of 1 mol L(-1) citrate buffer at pH 5. Antimony(III) and (V) in the extracts were separated and quantified by high-performance liquid chromatography combined on-line with inductively coupled plasma mass spectrometry (HPLC-ICP-MS). Antimony species concentrations (microg g(-1)) in the four fractions varied from 0.14 to 0.67 for Sb(III) and from 0.02 to 0.03 for Sb(V). The results reveal, for the first time, the occurrence of both inorganic Sb species in the extractable portion of volcanic ash. Sb(III) was always the predominant species.

Natural rain - induced element leaching from coal ASH; La pluie naturelle - lixiviation d'element de la cendre de charbon

Energy Technology Data Exchange (ETDEWEB)

Popovic, A.; Djordjevic, D.; Polic, P. [Belgrade Univ., Dept. of Chemistry, IChTM, Chemistry Center, Belgrade (Yugoslavia)

2000-07-01

Six composite samples of coal ash from power plants 'Nikola Tesla' A and B, located in the vicinity of Obrenovac, near Belgrade (Yugoslavia), were subjected to extraction with 1 M acetate solution, pH 5.5, in order to imitate possible leaching of the ash by natural acidic rain. Seven trace and five major elements have been examined, and the obtained amounts were in the range from 0.003 {+-} 0.001 ppm (Cd), to 117 {+-} 27 ppm (Ca), dry ash basis. Though some of the concentrations were higher than allowed by domestic and international regulations it can be concluded that neither of the examined elements represents a serious threat for the environment (at least for the conditions applied in this experiment). Also, both magnesium and iron are carriers of copper, chromium and arsenic, while cadmium is associated with magnesium and manganese. Calcium and manganese are beside magnesium and iron, scavengers of arsenic. (authors)

Concentrations of inorganic elements in biomass fuels and recovery in the different ash fractions

NARCIS (Netherlands)

Obernberger, I.; Biedermann, F.; Widmann, W.; Riedl, R.

1997-01-01

Inorganic elements and compounds in biomass fuels influence the combustion process and the composition of the ashes produced. Consequently, knowledge about the material fluxes of inorganic elements and compounds during biomass combustion for different kinds of biofuels and their influencing

Ash study for biogas purification

International Nuclear Information System (INIS)

Juarez V, R. I.

2016-01-01

This work evaluates the ashes generated from the wood and coal combustion process of the thermoelectric plant in Petacalco, Guerrero (Mexico) in order to determine its viability as a filter in the biogas purification process. The ash is constituted by particles of morphology and different chemical properties, so it required a characterization of the same by different analytical techniques: as was scanning electron microscopy and X-ray diffraction, in order to observe the microstructure and determine the elemental chemical composition of the particles. Prior to the analysis, a set of sieves was selected to classify as a function of particle size. Four different types of ashes were evaluated: one generated by the wood combustion (wood ash) and three more of the Petacalco thermoelectric generated by the coal combustion (wet fly ash, dry fly ash and dry bottom ash). (Author)

Ash content of lignites - radiometric analysis

International Nuclear Information System (INIS)

Leonhardt, J.; Thuemmel, H.W.

1986-01-01

The quality of lignites is governed by the ash content varying in dependence upon the geologic conditions. Setup and function of the radiometric devices being used for ash content analysis in the GDR are briefly described

Trace element partitioning in ashes from boilers firing pure wood or mixtures of solid waste with respect to fuel composition, chlorine content and temperature

Energy Technology Data Exchange (ETDEWEB)

Saqib, Naeem, E-mail: naeem.saqib@oru.se; Bäckström, Mattias, E-mail: mattias.backstrom@oru.se

2014-12-15

Highlights: • Different solids waste incineration is discussed in grate fired and fluidized bed boilers. • We explained waste composition, temperature and chlorine effects on metal partitioning. • Excessive chlorine content can change oxide to chloride equilibrium partitioning the trace elements in fly ash. • Volatility increases with temperature due to increase in vapor pressure of metals and compounds. • In Fluidized bed boiler, most metals find themselves in fly ash, especially for wood incineration. - Abstract: Trace element partitioning in solid waste (household waste, industrial waste, waste wood chips and waste mixtures) incineration residues was investigated. Samples of fly ash and bottom ash were collected from six incineration facilities across Sweden including two grate fired and four fluidized bed incinerators, to have a variation in the input fuel composition (from pure biofuel to mixture of waste) and different temperature boiler conditions. As trace element concentrations in the input waste at the same facilities have already been analyzed, the present study focuses on the concentration of trace elements in the waste fuel, their distribution in the incineration residues with respect to chlorine content of waste and combustion temperature. Results indicate that Zn, Cu and Pb are dominating trace elements in the waste fuel. Highly volatile elements mercury and cadmium are mainly found in fly ash in all cases; 2/3 of lead also end up in fly ash while Zn, As and Sb show a large variation in distribution with most of them residing in the fly ash. Lithophilic elements such as copper and chromium are mainly found in bottom ash from grate fired facilities while partition mostly into fly ash from fluidized bed incinerators, especially for plants fuelled by waste wood or ordinary wood chips. There is no specific correlation between input concentration of an element in the waste fuel and fraction partitioned to fly ash. Temperature and chlorine

Determination of radioactive trace elements in ashes and fly-ashes from Brazilian coal-fired power plants

International Nuclear Information System (INIS)

Bellido, L.F.; de Castro Arezzo, B.

1984-01-01

The aim of this work was to apply a epithermal neutron activation technique to determine the uranium and thorium content in coal ashes and fly ashes from Brazilian coal-fired thermoelectric plants and to evaluate the contribution of these elements and their descendents to the environmental radioactivity. Brazil has adopted as short term policy the use of alcohol and coal as alternative sources of energy. With regard to coal, large deposits of this mineral are found in southern states but the serious problem of its utilization is the risk of environmental contamination which can reach dangerous levels because the industrial plants burn several million tons per year. Uranium and thorium contents, determined experimentally, are extrapolated for annual coal consumption and their amounts and the activity of the radium isotopes descendents released to the atmosphere are calculated. The significance of these values and problems in environmental pollution are discussed

Trace element partitioning in ashes from boilers firing pure wood or mixtures of solid waste with respect to fuel composition, chlorine content and temperature.

Science.gov (United States)

Saqib, Naeem; Bäckström, Mattias

2014-12-01

Trace element partitioning in solid waste (household waste, industrial waste, waste wood chips and waste mixtures) incineration residues was investigated. Samples of fly ash and bottom ash were collected from six incineration facilities across Sweden including two grate fired and four fluidized bed incinerators, to have a variation in the input fuel composition (from pure biofuel to mixture of waste) and different temperature boiler conditions. As trace element concentrations in the input waste at the same facilities have already been analyzed, the present study focuses on the concentration of trace elements in the waste fuel, their distribution in the incineration residues with respect to chlorine content of waste and combustion temperature. Results indicate that Zn, Cu and Pb are dominating trace elements in the waste fuel. Highly volatile elements mercury and cadmium are mainly found in fly ash in all cases; 2/3 of lead also end up in fly ash while Zn, As and Sb show a large variation in distribution with most of them residing in the fly ash. Lithophilic elements such as copper and chromium are mainly found in bottom ash from grate fired facilities while partition mostly into fly ash from fluidized bed incinerators, especially for plants fuelled by waste wood or ordinary wood chips. There is no specific correlation between input concentration of an element in the waste fuel and fraction partitioned to fly ash. Temperature and chlorine content have significant effects on partitioning characteristics by increasing the formation and vaporization of highly volatile metal chlorides. Zinc and cadmium concentrations in fly ash increase with the incineration temperature. Copyright © 2014 Elsevier Ltd. All rights reserved.

Experimental investigation in separating the heavy metal elements of refuse incineration fly ashes by using molten iron

Energy Technology Data Exchange (ETDEWEB)

Yang, J. [Chongqing Univ., Chongqing (China)]|[CPI-Yuanda Environmental-protection Engineering Co. Ltd., Chongqing (China); Liu, Q.; Dong, L. [Chongqing Univ., Chongqing (China); Du, Y. [CPI-Yuanda Environmental-protection Engineering Co. Ltd., Chongqing (China)

2008-07-01

One of the main waste treatment methods in the world for municipal solid waste (MSW) is incineration. It is effective in toxic substance destruction, waste volume reduction, and energy recovery. Some chemical substances are accumulated during incineration, most notably lead, zinc, chromium and cadmium, as well as other heavy metals. Untreated fly ash disposed in landfills can pollute the soil, surface water and groundwater because of the high levels of hazardous heavy metals and high salt concentration that can be leached out. This paper presented an experiment that melt-separated the heavy metal elements from fly ash generated during refuse incineration. Molted iron, was used as resolvent to dissolve the heavy metal elements in it. The paper described the materials and methods as well as the results of the study. It was concluded that using molted iron to separate the heavy metal elements from MSW incineration fly ash was feasible. The removal ratio of the main heavy metal elements was above 80 per cent, and some of it was above 99 per cent. 5 refs., 7 tabs., 1 fig.

Faecal-wood biomass co-combustion and ash composition analysis.

Science.gov (United States)

Somorin, Tosin Onabanjo; Kolios, Athanasios J; Parker, Alison; McAdam, Ewan; Williams, Leon; Tyrrel, Sean

2017-09-01

Fuel blending is a widely used approach in biomass combustion, particularly for feedstocks with low calorific value and high moisture content. In on-site sanitation technologies, fuel blending is proposed as a pre-treatment requirement to reduce moisture levels and improve the physiochemical properties of raw faeces prior to drying. This study investigates the co-combustion performance of wood dust: raw human faeces blends at varying air-to-fuel ratios in a bench-scale combustor test rig. It concludes with ash composition analyses and discusses their potential application and related problems. The study shows that a 50:50 wood dust (WD): raw human faeces (FC) can reduce moisture levels in raw human faeces by ∼40% prior to drying. The minimum acceptable blend for treating moist faeces without prior drying at a combustion air flow rate of 14-18 L/min is 30:70 WD: FC. For self-sustained ignition and flame propagation, the minimum combustion temperature required for conversion of the fuel to ash is ∼400 °C. The most abundant elements in faecal ash are potassium and calcium, while elements such as nickel, aluminium and iron are in trace quantities. This suggests the potential use of faecal ash as a soil conditioner, but increases the tendency for fly ash formation and sintering problems.

Mutations in ash1 and trx enhance P-element-dependent silencing in Drosophila melanogaster.

Science.gov (United States)

McCracken, Allen; Locke, John

2016-08-01

In Drosophila melanogaster, the mini-w(+) transgene in Pci is normally expressed throughout the adult eye; however, when other P or KP elements are present, a variegated-eye phenotype results, indicating random w(+) silencing during development called P-element-dependent silencing (PDS). Mutant Su(var)205 and Su(var)3-7 alleles act as haplo-suppressors/triplo-enhancers of this variegated phenotype, indicating that these heterochromatic modifiers act dose dependently in PDS. Previously, we recovered a spontaneous mutation of P{lacW}ci(Dplac) called P{lacW}ci(DplacE1) (E1) that variegated in the absence of P elements, presumably due to the insertion of an adjacent gypsy element. From a screen for genetic modifiers of E1 variegation, we describe here the isolation of five mutations in ash1 and three in trx that enhance the E1 variegated phenotype in a dose-dependent and cumulative manner. These mutant alleles enhance PDS at E1, and in E1/P{lacW}ci(Dplac), but suppress position effect variegation (PEV) at In(1)w(m)(4). This opposite action is consistent with a model where ASH1 and TRX mark transcriptionally active chromatin domains. If ASH1 or TRX function is lost or reduced, heterochromatin can spread into these domains creating a sink that diverts heterochromatic proteins from other variegating locations, which then may express a suppressed phenotype.

Leaching of Major and Minor Elements during the Transport and Storage of Coal Ash Obtained in Power Plant

Directory of Open Access Journals (Sweden)

Rada Krgović

2014-01-01

Full Text Available In power plant, coal ash obtained by combustion is mixed with river water and transported to the dump. Sequential extraction was used in order to assess pollution caused by leaching of elements during ash transport through the pipeline and in the storage (cassettes. A total of 80 samples of filter ash as well as the ash from active (currently filled and passive (previously filled cassettes were studied. Samples were extracted with distilled water, ammonium acetate, ammonium oxalate/oxalic acid, acidic solution of hydrogen-peroxide, and a hydrochloric acid. Concentrations of the several elements (Al, As, Cd, Co, Cu, Cr, Fe, Ba, Ca, Mg, Ni, Pb, and Zn in all extracts were determined by inductively coupled plasma atomic emission spectrometry. Pattern recognition method was carried out in order to provide better understanding of the nature of distribution of elements according to their origins. Results indicate possible leaching of As, Ca, Cd, Cu, Zn, and Pb. Among these elements As, Cd, and Pb are toxicologically the most important but they were not present in the first two phases with the exception of As. The leaching could be destructive and cause negative effects on plants, water pollution, and damage to some life forms.

Trace element characteristics of indian cigarette tobacco by instrumental neutron activation analysis

International Nuclear Information System (INIS)

Garg, A.N.; Vivek Singh; Chutke, N.L.; Ambulkar, M.N.

1995-01-01

In order to determine hazardous effects of smoking five different brands of Indian cigarette tobacco including its ash and smoke, three brands of bi di (a typical of Indian subcontinent) and two of chewing tobacco have been analysed for 24 elements (As, Ba, Br, Ca, Ce, Co, Cr, Cs, Cu, Eu, Fe, Hg, K, Hf, La, Na, P, Rb, Sb, Sc, Se, Sr, Th and Zn) by instrumental neutron activation analysis (INAA). A simple and indigenous smoking device has been developed. A mean ash content of 16.5 ± 1.1% was obtained for different brands of cigarettes whereas smoke content was found to be 4.8±0.8%. It is observed that most elements are retained in ash and a few are transferred to smoke. Percent amount of elements retained in ash and transferred to smoke condensate have been calculated. Significant amounts of Sb, Hg, Co, Se and Zn are transferred to smoke but >90% of Ca, Fe, Sr and Cr are retained in ash. a comparison of elemental contents with the cigarette tobacco from other countries shows comparable amounts for most elements except few minor variations attributable to local soil characteristics. Most elemental contents in bi di and chewing tobacco are comparable except Br, Cr, Na, Se and Sr which are higher in chewing tobacco but its Ca content is lower. Standard Reference Materials Bowen's Kale, Kentucky Reference Cigarette and Citrus Leaves (SRM 1572) along with a newly developed tobacco CRM OTL-1 from Poland were also analysed. (author). 31 refs., 1 fig., 4 tabs

Laser-induced breakdown spectroscopy (LIBS) for rapid analysis of ash, potassium and magnesium in gluten free flours.

Science.gov (United States)

Markiewicz-Keszycka, Maria; Casado-Gavalda, Maria P; Cama-Moncunill, Xavier; Cama-Moncunill, Raquel; Dixit, Yash; Cullen, Patrick J; Sullivan, Carl

2018-04-01

Gluten free (GF) diets are prone to mineral deficiency, thus effective monitoring of the elemental composition of GF products is important to ensure a balanced micronutrient diet. The objective of this study was to test the potential of laser-induced breakdown spectroscopy (LIBS) analysis combined with chemometrics for at-line monitoring of ash, potassium and magnesium content of GF flours: tapioca, potato, maize, buckwheat, brown rice and a GF flour mixture. Concentrations of ash, potassium and magnesium were determined with reference methods and LIBS. PCA analysis was performed and presented the potential for discrimination of the six GF flours. For the quantification analysis PLSR models were developed; R 2 cal were 0.99 for magnesium and potassium and 0.97 for ash. The study revealed that LIBS combined with chemometrics is a convenient method to quantify concentrations of ash, potassium and magnesium and present the potential to classify different types of flours. Copyright © 2017 Elsevier Ltd. All rights reserved.

Concentrations and distributions of trace and minor elements in Chinese and Canadian coals and ashes

International Nuclear Information System (INIS)

Sun Jingxin; Jervis, R.E.

1987-01-01

A total of 35 trace and minor elements including some of environmental significance were determined in each of a selection of 15 Chinese and 6 Canadian thermal coals and their ashes by using the SLOWPOKE-2 nuclear reactor facility of the University of Toronto. The concentrations and distributions of these constituents among the coals and their combustion products (viz. ash and volatile matter) are presented. The detailed results showed wide variations in trace impurity concentrations (up to a factor of 100 and more) among the coals studied. Values for elemental enrichment factors (EF) relative to normal crustal abundances indicated that only As(EF=13), Br(5.7), I(16), S(230), Sb(11) and Se(320) were appreciably enriched in coal. (author) 14 refs.; 5 tabs

Selective determination of plutonium and transplutonic elements (Am, Cm) in feces ashes

International Nuclear Information System (INIS)

Ballada, J.; Verry, M.; Daburon, M.L.; Jeanmaire, L.

1983-02-01

A technique has been developed for the selective determination of the main transplutonic elements of the fuel cycle in feces ashes. The natural elements (U, Ra, Th and their isotopes) usually present in the human diet, are eliminated. Plutonium separation is carried out in a classical way by ion exchange resin. After elimination of U and Th, Am-Cm are collected on a millipore filter for α spectrometry or global counting. Yields are 95% (σ = 4) for Pu and 81.7% (σ = 6,2) for Am-Cm [fr

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

Science.gov (United States)

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

2012-02-01

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

Influence factors and corrections of low-energy γ-ray penetration in ash analysis

International Nuclear Information System (INIS)

Cheng Bo; Tuo Xianguo; Zhou Jianbin; Tong Yunfu

2002-01-01

The author introduces the system of the coal ash analyzer. This system is based on the low-energy γ-ray source 241 Am emitted two kinds of energy peaks 26.4 keV and 59.6 keV to analyze the ash in coal with the penetration way. The author also offers the factors to influence the accuracy of ash analysis, such as the size of coal, the environmental temperature, the important elements in coal, and water in coal too. At the same time, depending on the cause of the factors, it offer some methods of correction such as the way of the auto-hold energy peak, the way of the auto-compensation way, and so on. The author also mentions the other influence factors of the measurement accuracy to be noticed during the experiment. All these aim at clearing off the influence factors of measurement accuracy through the experiments

Investigation on the loss of trace elements in biological materials in different drying and ashing procedures by using radioactive tracers: Pt. 1

International Nuclear Information System (INIS)

Wang Yongxian; Qin Junfa; Ji Qianmei; Wu Shimin; Wang Xuepeng; Zhang Yuanxun

1985-01-01

By using radioactive tracers it is found that freezing dry is safe for Zn, Mo, Cd and Se in all matrices studied. Oven dry is also safe except for Se in hair. The oxygen plasma ashing does not cause any loss of Zn, Mo and Cd. Different degrees of loss were observed in oven ashing with exception of Zn and Mo in hair and shallot. It is obvious that the loss rate of the trace elements depends on their chemical forms present in the matrices. The retention of the four elements studied on the wall of quartz container can be neglected after oxygen plasma ashing. But Zn, Cd and Mo were retended in various degrees after oven ashing

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

pH-dependent leaching of dump coal ash - retrospective environmental analysis

Energy Technology Data Exchange (ETDEWEB)

Popovic, A.; Djordjevic, D. [University of Belgrade, Belgrade (Serbia). Dept. of Chemistry

2009-07-01

Trace and major elements in coal ash particles from dump of 'Nikola Tesla A' power plant in Obrenovac near Belgrade (Serbia) can cause pollution, due to leaching by atmospheric and surface waters. In order to assess this leaching potential, dump ash samples were subjected to extraction with solutions of decreasing pH values (8.50, 7.00, 5.50, and 4.00), imitating the reactions of the alkaline ash particles with the possible alkaline, neutral, and acidic (e.g., acid rain) waters. The most recently deposited ash represents the greatest environmental threat, while 'aged' ash, because of permanent leaching on the dump, was shown to have already lost this pollution potential. On the basis of the determined leachability, it was possible to perform an estimation of the acidity of the regional rainfalls in the last decades.

Speciation and mobility of potentially toxic elements in municipal solid waste incineration bottom ash

NARCIS (Netherlands)

Schollbach, K.; Alam, Q.; Florea, M.V.A.; Brouwers, H.J.H.

2017-01-01

Bottom ash (BA) is the main residue from municipal solid waste incineration (MSWI), which can have some applications in construction materials, but is mostly landfilled in many countries. The main problem is the high concentration of potentially toxic elements (PTEs), particularly in the fine

The synergistic effect in coal/biomass blend briquettes combustion on elements behavior in bottom ash using ICP-OES

Energy Technology Data Exchange (ETDEWEB)

Lazaroiu, G.; Frentiu, T.; Maescu, L.; Mihaltan, A.; Ponta, M.; Frentiu, M.; Cordos, E. [Universitatea Politehnica din Bucuresti, Bucharest (Romania)

2009-05-15

This paper focuses on the study of the synergistic effect in coal/biomass blend briquettes combustion on behavior of Al, As, Ba, Cd, Co. Cr, Cu, Fe, Ga, K, Mn, Mo, Ni, P, Pb, Si, V, W, Zn, Zr and characterization of raw materials and bottom ashes. The manufacturing of coal/biomass briquettes although not commonly used is an attractive approach, as briquettes combustion is more technologically advantageous than the fluidized bed combustion. In the same time this technology is a way to render valuable materials of low calorific power and results in diminishing polluting emission. Raw materials and briquettes from different blends of pitcoal/sawdust were subjected to combustion in a 55 kW-boiler. The total content of elements after digestion in the HNO{sub 3} - HF mixture and the content in water leachate at a solid/liquid ratio of 1:2 were determined both in raw materials and bottom ash by ICP-OES. The total content of elements was higher in pitcoal than in sawdust. The synergistic effect depends both on coal/biomass ratio in blend and element nature. The water leachable fraction of elements from ash decreased along with the increase of sawdust weight excepting macronutrients (K, P) and Si.

Trace elements release from volcanic ash to seawater. Natural concentrations in Central Mediterranean sea

Science.gov (United States)

Randazzo, L. A.; Censi, P.; Saiano, F.; Zuddas, P.; Aricò, P.; Mazzola, S.

2009-04-01

Distributions and concentrations of many minor and trace elements in epicontinental basins, as Mediterranean Sea, are mainly driven to atmospheric fallout from surroundings. This mechanism supplies an estimated yearly flux of about 1000 kg km-2 of terrigenous matter of different nature on the whole Mediterranean basin. Dissolution of these materials and processes occurring at solid-liquid interface along the water column drive the distributions of many trace elements as V, Cr, Mn, Co, Cu, and Pb with contents ranging from pmol l-1 (Co, Cd, Pb) to nmol l-1 scale in Mediterranean seawater, with some local differences in the basin. The unwinding of an oceanographic cruise in the coastal waters of Ionian Sea during the Etna's eruptive activity in summer 2001 led to the almost unique chance to test the effects of large delivery of volcanic ash to a coastal sea water system through the analyses of distribution of selected trace elements along several seawater columns. The collection of these waters and their analyses about V, Cr, Mn, Co, Cu, and Pb contents evidenced trace element concentrations were always higher (about 1 order of magnitude at least) than those measured concentrations in the recent past in Mediterranean seawater, apart from Pb. Progressive increase of concentrations of some elements with depth, sometimes changing in a "conservative" behaviour without any clear reason and the observed higher concentrations required an investigation about interaction processes occurring at solid-liquid interface between volcanic ash and seawater along water columns. This investigation involving kinetic evaluation of trace element leaching to seawater, was carried out during a 6 months time period under laboratory conditions. X-ray investigations, SEM-EDS observations and analyses on freshly-erupted volcanic ash evidenced formation of alteration clay minerals onto glass fraction surfaces. Chemical analyses carried out on coexisting liquid phase demonstrated that trace

Determination of toxic elements in tobacco products by instrumental neutron activation analysis

International Nuclear Information System (INIS)

Ahmad, S.; Chaudhry, M.S.; Qureshi, I.H.

1979-01-01

The concentration of 15 elements in various brands of cigarette tobacco and cigarette wrapping paper were determined using instrumental neutron activation analysis. The paper of some of the brands contains higher concentrations of toxic elements than the tobacco. The cigarette filter and the ash were also analyzed to determine the adsorption of toxic elements on the filter and their transference in smoke. The toxic effects of some of the elements have been briefly discussed. (author)

Analytical applications of atomic spectroscopy, with particular reference to inductively coupled plasma emission analysis of coal and fly ash

International Nuclear Information System (INIS)

Pougnet, M.A.B.

1983-08-01

This thesis outlines the analytical applications of atomic emission and absorption spectroscopy to a variety of materials. Special attention was directed to the analysis of coal and coal ashes. A simple slurry sampling technique was developed and used to determine V, Ni, Co, Mo and Mn in the National Bureau of Standards Standard Reference Materials (NBS-SRM) coals 1632a and 1635 by furnace atomic absorption spectroscopy (FAAS). Coal and fly ash were analysed by inductively coupled plasma atomic emission spectroscopy (ICP-AES). The determination of B, Be, Li, C, K and other trace elements by ICP-AES was investigated. Analytical methods were developed for the analysis of coal, fly ash and water samples. Fusion with sodium carbonate and a digestion bomb dissolution method were compared for the determination of boron in a South African boron-rich mineral (Kornerupine). Eight elements were determined in 10 industrial water samples from a power plant. Ca, Mg, Si and B were determined by ICP-AES and V, Ni, Co and Mo by FAAS. Various problems encountered during the course of the work and interferences in ICP-AES analysis are discussed. Some recommendations concerning method development and routine analysis by this technique are suggested

Analysis of trace elements in serum from human eating irradiated food

International Nuclear Information System (INIS)

Huang Zongzhi; Zhou Hongdi; Chen Shijie; Gao Sumei

1987-01-01

A method of trace element analysis by Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AEC) in serum from human eating food preserved by irradiation is described. Trace element analysis in human serum is one of the research projects concerning the wholesomeness. 78 serum samples of the human eating food preserved by irradiation were collected. After ashing and solving ICP-AES analysis of serum is performed for detecting 12 trace elements in specimen solution. The detection limitations are in the range of 10 -2 - 10 -3 ppm for differemt elements. The recoveries of elements are over 73%. Concentrations of 12 trace elements in 78 human serum has been calculated with F and t tests at PDP 11/70 computer and it was concluded that there is no significant difference between testing group and control group

Coal fly ash basins as an attractive nuisance to birds: parental provisioning exposes nestlings to harmful trace elements.

Science.gov (United States)

Bryan, A L; Hopkins, W A; Parikh, J H; Jackson, B P; Unrine, J M

2012-02-01

Birds attracted to nest around coal ash settling basins may expose their young to contaminants by provisioning them with contaminated food. Diet and tissues of Common Grackle (Quiscalus quiscala) nestlings were analyzed for trace elements to determine if nestlings were accumulating elements via dietary exposure and if feather growth limits elemental accumulation in other tissues. Arsenic, cadmium, and selenium concentrations in ash basin diets were 5× higher than reference diets. Arsenic, cadmium, and selenium concentrations were elevated in feather, liver, and carcass, but only liver Se concentrations approached levels of concern. Approximately 15% of the total body burden of Se, As, and Cd was sequestered in feathers of older (>5 days) nestlings, whereas only 1% of the total body burden of Sr was sequestered in feathers. Feather concentrations of only three elements (As, Se, and Sr) were correlated with liver concentrations, indicating their value as non-lethal indicators of exposure. Copyright © 2011 Elsevier Ltd. All rights reserved.

ICP-AES determination of rare earth elements in coal fly ash samples of thermal power stations: assessment of possible recovery and environmental impact of rare earth elements

International Nuclear Information System (INIS)

Premadas, A.; Mary, Thomas Anitha; Chakrapani, G.

2013-01-01

Accurate determination of rare earth elements (REEs) in ashes of thermal power plants is important in the current scenario due to its economic value, and the pollution caused if they are released in to the environment. Their toxicity to living organisms now gaining importance in international community, and some investigation shows it causes retardation in plant growth. In coal based thermal stations huge quantity of coal used annually as a fuel and lakhs of tones of waste is generated in the form of ashes. Therefore studies were carried out on three aspects - fairly rapid and accurate ICP-AES determination REEs in coal fly ash samples using addition technique, a preliminary acid leaching studies on coal received from three different fired thermal power stations using hydrochloric acid at pH 1 and 2, and quantify the REEs leached, and economic recovery of REEs using di-(2-ethylhexyl) phosphoric acid solvent extraction process or precipitation hydroxides using dilute ammonia solution. The standard addition method of REEs determination using rate and reproducible values, besides the analysis is fast compared to the ion exchange separation of REEs followed by the ICP-AES determination. (author)

Geochemical modeling and assessment of leaching from carbonated municipal solid waste incinerator (MSWI) fly ash.

Science.gov (United States)

Wang, Lei; Chen, Qi; Jamro, Imtiaz Ali; Li, Rundong; Li, Yanlong; Li, Shaobai; Luan, Jingde

2016-06-01

Municipal solid waste incinerator (MSWI) fly ashes are characterized by high calcium oxide (CaO) content. Carbon dioxide (CO2) adsorption by MSWI fly ash was discussed based on thermogravimetry (TG)/differential thermal analysis (DTA), minerology analysis, and adapting the Stenoir equation. TG/DTA analysis showed that the weight gain of the fly ash below 440 °C was as high as 5.70 %. An adapted Stenoir equation for MSWI fly ash was discussed. The chloride in MSWI fly ash has a major impact on CO2 adsorption by MSWI fly ash or air pollution control (APC) residues. Geochemical modeling of the critical trace elements copper (Cu), cadmium (Cd), zinc (Zn), lead (Pb), and antimony (Sb) before and after carbonation was performed using a thermodynamic equilibrium model for solubility and a surface complexation model for metal sorption. Leaching of critical trace elements was generally found to be strongly dependent on the degree of carbonation attained, and their solubility appeared to be controlled by several minerals. Adsorption on ferrum (Fe) and aluminum (Al) colloids was also responsible for removal of the trace elements Cd, Pb, and Sb. We used Hakanson's potential ecological risk index (HPERI) to evaluate the risk of trace element leaching in general. The results demonstrate that the ecological risk showed a V-shaped dependency on pH; the optimum pH of the carbonated fly ash was found to be 10.3-11, resulting from the optimum carbonation (liquid-to-solid (L/S) ratio = 0.25, carbonation duration = ∼30-48 h). The dataset and modeling results presented here provide a contribution to assessing the leaching behavior of MSWI fly ash under a wide range of conditions.

Correlation of tephra layers by trace elements abundances in glass shards

Energy Technology Data Exchange (ETDEWEB)

Fukuoka, Takaaki

1988-10-01

For identifying volcanic ash layer, a method was explained by analyzing minor elements contained in glassy material of volcanic ash. Based upon the understanding that glassy material in volcanic ash was formed by the quenching of magma and that composition of it reflected the composition of magma at the time of deposition, identification of volcanic ash layer was conducted by applying such consideration that minor elements were concentrated in the magma during the deposition process and that distribution coefficient was characteristic of every minor element. For the analysis, apparatus of irradiated neutron was applied. As the result of analysis, variation of the data was approximately 5% among the ashes belong to the same volcano. distribution map of volcanic ash in Japan was prepared by using the result. By this, it was understood that the ashes obtained from the volcanos in the middle part of Japan were different from other but those from Kyushu district were mostly identical among them. For further study of volcano, necessity of such analysis of volcanic ash in the sea bottom mud was explained. 3 references, 2 figures, 1 table.

Use of INAA for investigation of emission of elements in combustion of Polish lignite

International Nuclear Information System (INIS)

Janczyszyn, J.; Loska, L.; Pohorecki, W.; Wagner, M.

2002-01-01

Instrumental neutron activation analysis (INAA) has been applied for the determination of trace elements content in samples of Polish lignite and its ash. Pairs of results, for lignite and ash, and respective ash contents were used for calculation of the percentage of element remaining in ash after the lignite combustion. (author)

Measuring ash content of coal

International Nuclear Information System (INIS)

Clayton, C.G.; Wormald, M.R.

1980-01-01

An apparatus for measuring the ash content of coal is claimed. It comprises a means for irradiating a known quantity of coal in a transport container with a known dose of neutrons, a means for detecting γ-rays having a predetermined energy emitted by the irradiated coal, the γ-rays being indicative of the presence of an ash-forming element in the coal, a means for producing a signal related to the intensity of the γ-ray emission and a means responsive to the signal to provide an indication of the concentration of the ash-forming element in the coal

Study on plasma melting treatment of crucibles, ceramic filter elements, asbestos, and fly ash

International Nuclear Information System (INIS)

Hoshi, Akiko; Nakasio, Nobuyuki; Nakajima, Mikio

2004-01-01

The Japan Atomic Energy Research Institute (JAERI) decided to adopt an advanced volume reduction program for low-level radioactive wastes. In this program, inorganic wastes are converted to stable glassy products suitable for disposal by a plasma melting system in the Waste Volume Reduction Facilities (WVRF). High melting point wastes such as refractories are excluded from the plasma melting treatment in the WVRF, and wastes difficult to handle such as asbestos are also excluded. However, it is describable to apply the plasma melting treatment to these wastes for stabilization and volume reduction from the viewpoint of disposal. In this paper, plasma melting test of crucibles, ceramic filter elements, asbestos, and simulated fly ashes were carried out as a part of technical support for WVRF. The plasma melting treatment was applicable for crucibles and asbestos because homogeneous and glassy products were obtained by controlling of waste and loading condition. It was found that SiC in ceramic filter elements was volatile with a plasma torch with inert gas, and adding reducer was ineffective against stabilizing volatile metals such as Zn, Pb in a solidified product in the melting test of simulated fly ash. (author)

Ash properties of some dominant Greek forest species

International Nuclear Information System (INIS)

Liodakis, S.; Katsigiannis, G.; Kakali, G.

2005-01-01

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

Ash properties of some dominant Greek forest species

Energy Technology Data Exchange (ETDEWEB)

Liodakis, S. [Laboratory of Inorganic and Analytical Chemistry, Department of Chemical Engineering, National Technical University of Athens (NTUA), 9 Iroon Polytechniou Street, Athens 157 73 (Greece)]. E-mail: liodakis@central.ntua.gr; Katsigiannis, G. [Laboratory of Inorganic and Analytical Chemistry, Department of Chemical Engineering, National Technical University of Athens (NTUA), 9 Iroon Polytechniou Street, Athens 157 73 (Greece); Kakali, G. [Laboratory of Inorganic and Analytical Chemistry, Department of Chemical Engineering, National Technical University of Athens (NTUA), 9 Iroon Polytechniou Street, Athens 157 73 (Greece)

2005-10-15

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

Determination of the elemental distribution in cigarette components and smoke by instrumental neutron activation analysis

International Nuclear Information System (INIS)

Wu, D.; Landsberger, S.; Larson, S.M.

1997-01-01

Cigarette smoking is a major source of particle released in indoor environments. A comprehensive study of the elemental distribution in cigarettes and cigarette smoke has been completed. Specifically, concentrations of thirty elements have been determined for the components of 15 types of cigarettes. Components include tobacco, ash, butts, filters, and cigarette paper. In addition, particulate matter from mainstream smoke (MS) and sidesstream smoke (SS) were analyzed. The technique of elemental determination used in the study is instrumental neutron activation analysis. The results show that certain heavy metals, such as As, Cd, K, Sb and Zn, are released into the MS and SS. These metals may then be part of the health risk of exposure to smoke. Other elements are retained, for the most part, in cigarette ash and butts. The elemental distribution among the cigarette components and smoke changes for different smoking conditions. (author)

Analysis of elements present in beers and brewing waters by neutron activation analysis

International Nuclear Information System (INIS)

Krausova, Ivana; Kucera, Jan; Dostalek, Pavel; Potesil, Vaclav

2011-01-01

Neutron activation analysis (NAA) was used for determination of Si, Na, K, Ca, Sc, V, Cr, Mn, Fe, Co, Zn, Rb, Cs, and La in Czech beers and brewing waters. The Si concentration in beer determined by the reaction 29 Si(n,p) 29 Al with fast neutrons confirmed that beer is an important Si source in human diet. Determination of other trace elements by NAA with the whole spectrum of reactor neutrons aimed at the feasibility of identification of Gambrinus beers brewed in various breweries. The elements Ca and V appeared to be the best candidates for this purpose. The concentrations of elements determined by NAA were also compared with the recommended daily element intake for humans. The accuracy of the method was proved by analysis of reference materials, specifically NIST SRM 2704 Buffalo River Sediment, NIST SRM 1633b Coal Fly Ash, and NIST SRM 1515 Apple Leaves. (author)

Evaluation of trace elements in chewing tobacco and snuff using instrumental neutron activation analysis (INAA) and atomic absorption spectroscopy (AAS)

International Nuclear Information System (INIS)

Waheed, S.; Siddique, N.; Rahman, S.

2009-01-01

Nine samples of chewing tobacco, snuff, tobacco leaf and ash were analyzed using Instrumental Neutron Activation Analysis (INAA) and Atomic Absorption Spectroscopy (AAS). Almost all samples of chewing tobacco and snuff studied in this work contain substantial amounts of Mg, Mn, Na, K. V. Sc, Rb and Fe. Furthermore, varying amounts of Al, Ba, Ca, Ce, Co and Zn were also detected in all tobacco samples. Of the toxic elements which were determined using INAA. As, Sb and Hg were quantified in only few tobacco samples. However, other toxic elements, which were determined using AAS, such as Cu, Pb and Cd were detected in almost all samples of chewing tobacco and snuff. The concentration of majority of the detected elements is high in ash samples which imply that most elements in chewing tobacco and snuff may originate from the addition of ash. (orig.)

Evaluation of trace elements in chewing tobacco and snuff using instrumental neutron activation analysis (INAA) and atomic absorption spectroscopy (AAS)

Energy Technology Data Exchange (ETDEWEB)

Waheed, S.; Siddique, N.; Rahman, S. [Chemistry Div., Directorate of Science, Pakistan Inst. of Nuclear Science and Tech., Islamabad (Pakistan)

2009-07-01

Nine samples of chewing tobacco, snuff, tobacco leaf and ash were analyzed using Instrumental Neutron Activation Analysis (INAA) and Atomic Absorption Spectroscopy (AAS). Almost all samples of chewing tobacco and snuff studied in this work contain substantial amounts of Mg, Mn, Na, K. V. Sc, Rb and Fe. Furthermore, varying amounts of Al, Ba, Ca, Ce, Co and Zn were also detected in all tobacco samples. Of the toxic elements which were determined using INAA. As, Sb and Hg were quantified in only few tobacco samples. However, other toxic elements, which were determined using AAS, such as Cu, Pb and Cd were detected in almost all samples of chewing tobacco and snuff. The concentration of majority of the detected elements is high in ash samples which imply that most elements in chewing tobacco and snuff may originate from the addition of ash. (orig.)

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

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

Science.gov (United States)

Kalaw, Martin Ernesto; Culaba, Alvin; Hinode, Hirofumi; Kurniawan, Winarto; Gallardo, Susan; Promentilla, Michael Angelo

2016-07-15

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), scanning

A Comparative Analysis of Nutrients and Mineral Elements Content ...

African Journals Online (AJOL)

(Mg), Iron (Fe), Copper (Cu) and Zinc (Zn) content, while P. pedicellatum has high ... INTRODUCTION ... central to animal production and productivity. .... for growth and serve as structural element in all plant ... the animal's body, it ensured correct maintenance of ... Ash content because Ash is the approximation of total.

Effects of a low severity prescribed fire on water-soluble elements in ash from a cork oak (Quercus suber) forest located in the northeast of the Iberian Peninsula.

Science.gov (United States)

Pereira, Paulo; Ubeda, Xavier; Martin, Deborah; Mataix-Solera, Jorge; Guerrero, César

2011-02-01

Wildfire is the major disturbance in Mediterranean forests. Prescribed fire can be an alternative to reduce the amount of fuel and hence decrease the wildfire risk. However the effects of prescribed fire must be studied, especially on ash properties, because ash is an important nutrient source for ecosystem recovery. The aim of this study is to determine the effects of a low severity prescribed fire on water-soluble elements in ash including pH, electrical conductivity (EC), calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), aluminum (Al), manganese (Mn), iron (Fe), zinc (Zn), silica (SiO(2)) and total sulphur (TS). A prescribed fire was conducted in a cork oak (Quercus suber) (Q.S) forest located in the northeast part of the Iberian Peninsula. Samples were collected from a flat plot of 40×70m mainly composed of Q.S and Quercus robur (Q.R) trees. In order to understand the effects of the prescribed fire on the soluble elements in ash, we conducted our data analysis on three data groups: all samples, only Q.S samples and only Q.R samples. All three sample groups exhibited a significant increase in pH, EC (pfire induced a higher variability in the ash soluble elements, especially in Q.S samples, that at some points burned with higher severity. The increase of pH, EC, Ca, Mg, Na and K will improve soil fertility, mainly in the study area where soils are acidic. The application of this low severity prescribed fire will improve soil nutrient status without causing soil degradation and thus is considered to be a good management strategy. Copyright © 2010 Elsevier Inc. All rights reserved.

Recirculation of biomass ashes onto forest soils: Ash composition, mineralogy and leaching properties

DEFF Research Database (Denmark)

Maresca, Alberto; Hyks, J.; Astrup, Thomas Fruergaard

2017-01-01

In Denmark, increasing amounts of wood ashes are generated from biomass combustion for energy production. The utilisation of ashes on top of forest soil for liming purposes has been proposed asan alternative to landfilling. Danish wood ash samples were collected and characterised with respect......, minor and trace elements were affected significantly by pH: high releases of PO4 3-, Mg, Zn, Cu and Cd were found for acidic conditions relevant to forest soils, while the highest releases of Mo and Cr were observed in alkaline conditions. Mineral phases were selected based on XRD analyses...... critical element compared with soil quality criteria, whereas the maximum theoretical loads of Ba, Cd, Cr, Sr, Mo, Ni, Pb, Sb, Se, Sn and V were relatively low....

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.

Ash behavior during hydrothermal treatment for solid fuel applications. Part 1: Overview of different feedstock

International Nuclear Information System (INIS)

Mäkelä, Mikko; Fullana, Andrés; Yoshikawa, Kunio

2016-01-01

Highlights: • Ash behavior of 29 different feedstock interpreted using multivariate data analysis. • Two different groups identified based on char ash content and ash yield. • Solubility of individual elements evaluated based on a smaller data set. • Ash from industrial sludge contained anthropogenic metals with low solubility. - Abstract: Differences in ash behavior during hydrothermal treatment were identified based on multivariate data analysis of literature information on 29 different feedstock. In addition, the solubility of individual elements was evaluated based on a smaller data set. As a result two different groups were distinguished based on char ash content and ash yield. Virgin terrestrial and aquatic biomass, such as different types of wood and algae, in addition to herbaceous and agricultural biomass, bark, brewer’s spent grain, compost and faecal waste showed lower char ash content than municipal solid wastes, anaerobic digestion residues and municipal and industrial sludge. Lower char ash content also correlated with lower ash yield indicating differences in chemical composition and ash solubility. Further evaluation of available data showed that ash in industrial sludge mainly contained anthropogenic Al, Fe and P or Ca and Si with low solubility during hydrothermal treatment. Char from corn stover, miscanthus, switch grass, rice hulls, olive, artichoke and orange wastes and empty fruit bunch had generally higher contents of K, Mg, S and Si than industrial sludge although differences existed within the group. In the future information on ash behavior should be used for enhancing the fuel properties of char based on feedstock type and hydrothermal treatment conditions.

Characterization and determination of 28 elements in fly ashes collected in a thermal power plant in Argentina using different instrumental techniques

International Nuclear Information System (INIS)

Marrero, Julieta; Polla, Griselda; Jimenez Rebagliati, Raul; Pla, Rita; Gomez, Dario; Smichowski, Patricia

2007-01-01

Different techniques were selected for comprehensive characterization of seven samples of fly ashes collected from the electrostatic precipitator of the San Nicolas thermal power plant (Buenos Aires, Argentina). Particle size was measured using laser based particle size analyzer. X-ray diffraction powder (XRD) analysis and scanning electron microscopy (SEM) were used to characterize the mineral phase present in the matrix consisting basically of aluminosilicates and large amounts of amorphous material. The predominant crystalline phases were mullite and quartz. Major and minors elements (Al, Ca, Cl, Fe, K, Mg, Na, S, Si and Ti) were detected by energy dispersive X-ray analysis (EDAX). Trace elements (As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Se, V and Zn) content was quantified by inductively coupled plasma optical emission spectrometry (ICP OES). Different acid mixtures and digestion procedures were compared for subsequent ICP OES measurements of the dissolved samples. The digestion procedures used were: i) a mixture of FH + HNO 3 + HClO 4 (open system digestion); ii) a mixture of FH + HNO 3 (MW-assisted digestion); iii) a mixture of HF and aqua regia (MW-assisted digestion). Instrumental neutron activation analysis (INAA) was employed for the determination of As, Ba, Co, Cr, Ce, Cs, Eu, Fe, Gd, Hf, La, Lu, Rb, Sb, Sc, Sm, Ta, Tb, Th, U and Yb. The validation of the procedure was performed by the analysis of two certified materials namely, i) NIST 1633b, coal fly ash and ii) GBW07105, rock. Mean elements content spanned from 41870 μg g -1 for Fe to 1.14 μg g -1 for Lu. The study showed that Fe (41870 μg g -1 ) >> V (1137 μg g -1 ) > Ni (269 μg g -1 ) > Mn (169 μg g -1 ) are the main components. An enrichment, with respect to crustal average, in many elements was observed especially for As, V and Sb that deserve particular interest from the environmental and human health point of view

Ash contents of foodstuff samples in environmental radioactivity analysis

International Nuclear Information System (INIS)

Oikawa, Shinji; Ohta, Hiroshi; Hayano, Kazuhiko; Nonaka, Nobuhiro

2004-01-01

Statistical data of the ash content in various environmental samples obtained from an environmental radioactivity survey project commissioned by the Japanese government of Science and Technology Agency (at present Ministry of Education, Culture, Sports, Sciences and Technology) during the past 10 years are expressed for establishing a standard of ash content in environmental samples based on radioactivity analysis. The ash content for some kinds of environmental samples such as dietary food, milk, Japanese radish, spinach, fish, green tea and potato was reviewed in the light of statistical and stochastic viewpoints. For all of the samples reviewed in this paper, the coefficient of variation varied from 4.7% for milk to 36.3% for cabbage. Dietary food and milk samples were reviewed more than 1900 and 1400 samples, respectively. Especially, ash content of dietary food depended mainly on the dietary culture reflected on the period. However it showed an almost invariant distribution within 18.7% of coefficient of variation during the past 10 years. Pretreatment of environmental samples especially ashing processes are important from the viewpoint on environmental radioactivity analysis, which is one of the especial fields in analytical chemistry. Statistical reviewed data obtained in this paper may be useful for sample preparation. (author)

Ge extraction from gasification fly ash

Energy Technology Data Exchange (ETDEWEB)

Oriol Font; Xavier Querol; Angel Lopez-Soler; Jose M. Chimenos; Ana I. Fernandez; Silvia Burgos; Francisco Garcia Pena [Institute of Earth Sciences ' Jaume Almera' , Barcelona (Spain)

2005-08-01

Water-soluble germanium species (GeS{sub 2}, GeS and hexagonal-GeO{sub 2}) are generated during coal gasification and retained in fly ash. This fact together with the high market value of this element and the relatively high contents in the fly ashes of the Puertollano Integrated Gasification in Combined Cycle (IGCC) plant directed our research towards the development of an extraction process for this element. Major objectives of this research was to find a low cost and environmentally suitable process. Several water based extraction tests were carried out using different Puertollano IGCC fly ash samples, under different temperatures, water/fly ash ratios, and extraction times. High Ge extraction yields (up to 84%) were obtained at room temperature (25{sup o}C) but also high proportions of other trace elements (impurities) were simultaneously extracted. Increasing the extraction temperature to 50, 90 and 150{sup o}C, Ge extraction yields were kept at similar levels, while reducing the content of impurities, the water/fly ash ratio and extraction time. The experimental data point out the influence of chloride, calcium and sulphide dissolutions on the Ge extraction. 16 refs., 9 figs., 6 tabs.

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

Fixed-bed studies of the interactions between mercury and coal combustion fly ash

Energy Technology Data Exchange (ETDEWEB)

Dunham, Grant E.; DeWall, Raymond A. [Energy and Environmental Research Center, 15 North 23rd Street, Grand Forks, ND 58203 (United States); Senior, Constance L. [Reaction Engineering International, 77 West 200 South, Suite 210, Salt Lake City, UT 84101 (United States)

2003-08-15

Sixteen different fly ash samples, generated from both pilot-scale and full-scale combustion systems, were exposed to a simulated flue gas containing either elemental mercury or HgCl{sub 2} in a bench-scale reactor system at the Energy and Environmental Research Center to evaluate the interactions and determine the effects of temperature, mercury species, and ash type on adsorption of mercury and oxidation of elemental mercury. The fly ash samples were characterized for surface area, loss on ignition, and forms of iron in the ash. While many of the ash samples oxidized elemental mercury, not all of the samples that oxidized mercury also captured elemental mercury. However, no capture of elemental mercury was observed without accompanying oxidation. Generally, oxidation of elemental mercury increased with increasing amount of magnetite in the ash. However, one high-carbon subbituminous ash with no magnetite showed considerable mercury oxidation that may have been due to unburned carbon. Surface area as well as the nature of the surface appeared to be important for oxidation and adsorption of elemental mercury. The capacity of the ash samples for HgCl{sub 2} was similar to that for elemental mercury. There was a good correlation between the capacity for HgCl{sub 2} and the surface area; capacity decreased with increasing temperature.

Ash study for biogas purification; Estudio de cenizas para purificacion de biogas

Energy Technology Data Exchange (ETDEWEB)

Juarez V, R. I.

2016-07-01

This work evaluates the ashes generated from the wood and coal combustion process of the thermoelectric plant in Petacalco, Guerrero (Mexico) in order to determine its viability as a filter in the biogas purification process. The ash is constituted by particles of morphology and different chemical properties, so it required a characterization of the same by different analytical techniques: as was scanning electron microscopy and X-ray diffraction, in order to observe the microstructure and determine the elemental chemical composition of the particles. Prior to the analysis, a set of sieves was selected to classify as a function of particle size. Four different types of ashes were evaluated: one generated by the wood combustion (wood ash) and three more of the Petacalco thermoelectric generated by the coal combustion (wet fly ash, dry fly ash and dry bottom ash). (Author)

Ash transformation and deposit build-up during biomass suspension and grate firing: Full-scale experimental studies

DEFF Research Database (Denmark)

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

2012-01-01

An attractive option for reducing the net CO2 emissions is to substitute coal with biomass in large power plant boilers. However, the presence of chlorine (Cl) and alkali metals (K, Na) in biomassmay induce large operational problems due to ash deposit formation on the superheater tubes. The aim...... of this study was to investigate ash transformation and deposition behavior in two biomass-fired boilers, firing wheat straw and/or wood. The influence of strawfiring technology (grate and suspension) on the ash transformation, deposit formation rate and deposit characteristics has been investigated. Bulk...... elemental analysis of fly ashes revealed that fly ash from suspension firing of straw has high contents of Si, K and Ca, while fly ash from straw firing on grate was rich in the volatile elements K, Cl and S. Investigations of deposit formation ratesweremade in the superheater and convective pass regions...

Elemental analysis using instrumental neutron activation analysis and inductively coupled plasma atomic emission spectrometry: a comparative study

International Nuclear Information System (INIS)

Chung, Yong Sam; Choi, Kwang Soon; Moon, Jong Hwa; Kim, Sun Ha; Lim, Jong Myoung; Kim, Young Jin; Quraishi, Shamshad Begum

2003-05-01

Elemental analyses for certified reference materials were carried out using instrumental neutron activation analysis and inductively coupled plasma-atomic emission spectrometry. Five Certified Reference Materials (CRM) were selected for the study on comparative analysis of environmental samples. The CRM are Soil (NIST SRM 2709), Coal fly ash (NIST SRM 1633a), urban dust (NIST SRM 1649a) and air particulate on filter media (NIST SRM 2783 and human hair (GBW 09101)

Utilization of wood ash as seedling media of Cocoa (Theobroma cacao

Directory of Open Access Journals (Sweden)

Fitria Nugraheni Sukmawati

2016-12-01

Full Text Available An effort to increase productivity is provision of inorganic fertilizers. Inorganic fertilizer application in longtem as found to attenuate the availability of micronutrients and to decrease soil fertility. One possibility to replace inorganic fertilizer is the use of ash derived from plants, such as wood ash. The purpose of this study was to determine the effect of wood ash on soil K availability and to optimize the dose of wood ash which can give good influence on the growth of cocoa seedlings. The experiment was conducted at the experimental station Polytechnic LPP in Wedomartani, Sleman, Yogyakarta. The design used is non factorial randomized block design with 5 treatments, which is the ratio of ash and soil 0: 1 (A1 / Control; 0.25: 1 (A2; 0.5: 1 (A3; 0.75: 1 (A4; and 1: 1 (A5. Observations of treatment effects were made on the seedling height, number of leaves, stem diameter, wet weight and dry weight. Soil analysis was conducted to determine the content of macro elements, micro elements, and pH media. The results showed that ash increases the pH of the media to alkaline range and increase the availability of P and K soil to toxic range. Giving ash reduced the availability of N and caused chlorosis on cocoa seedlings.

ICP-AES analysis of trace elements in serum from animals fed with irradiated food

International Nuclear Information System (INIS)

Huang Zongzhi; Zhou Hongdi

1986-01-01

A method of trace element analysis by ICP-AES in serum from animals fed with irradiated food is described. In order to demonstrate that irradiated food is suitable for human consumption, it is necessary to perform an experiment of animal feeding with these food before use for human. Trace element analysis in animal serum could provide an actual evidence for further human consumption study. 53 serum samples of the rats fed with irradiated food were obtained. After ashed and solved, ICP-AES analysis has been used for determining 20 trace elements in specimen solution. The detection limitation is in the range of 10 -2 -10 -3 ppm for different elements. The recovery of elements is from 70.08% to 98.28%. The relative standard deviation is found to be 0.71% to 11.52%

Clean up fly ash from coal burning plants by new isolated fungi Fusarium oxysporum and Penicillium glabrum.

Science.gov (United States)

Ertit Taştan, Burcu

2017-09-15

In Turkey approximately 45 million tons of coals are burned in a year and 19.3 million tons of fly ash have emerged. The bioremediation of heavy metals or different elements from fly ash makes them bio-available. However, in previous studies, requiring of long operational time and failing to show tolerance to high pulp densities of fly ash of selected fungal species makes them impractical. In this work, bioremediation of fly ash by new isolated fungi Fusarium oxysporum and Penicillium glabrum were investigated in one step and two step bioremediation process. Ca, Si, Fe and S were found to be considerable amount in studied fly ashes by ED-XRF element analysis. The bioremediation yields of Mo (100%), S (64.36%) Ni (50%) and Cu (33.33%) by F. oxysporum were high. The remediated elements by P. glabrum in fly ash were Mo (100%), S (57.43%), Ni (25%), Si (24.66%), V (12.5%), Ti (5%) and Sr (3.2%). The isolation of high fly ash resistant fungi and reduction of the bioremediation time will allow the practical applications of the bioremediation technology when it is scaled up. Copyright © 2017 Elsevier Ltd. All rights reserved.

Power plant ash and slag waste management technological direction when Kansk-Achinsk brown coal is burned

Directory of Open Access Journals (Sweden)

Lihach Snejana A.

2017-01-01

Full Text Available Today resource efficiency technology development in all industries where conventional raw material is being replaced by local natural resources and industrial waste is an essential matter. Along with that most producing operations are overload with wide range of waste produced during technological process. Thermal power stations are real world evidence. Their main waste is ash and slag which accumulated in great amounts in often overfull ash dumps. The goal of present work is to find perspective ash dump waste utilization methods. The study will be based on experimentally obtained data: elementary compound and properties of Kansk-Achinsk brown coal. Research methods: experimental, chemical silicate analysis, mineralogical forms identification within samples by using ASM X-ray diffraction analysis. Experiments resulted with the following conclusions: silica is ash main component, and ash has the form of ore concentrate analogy in a number of elements. We think that ASM main properties which make it useful for utilization are: high content of calcium oxide; high ash sorption properties; ASM radiation safety class which makes them safe to be used in materials, goods, and structures production for residence and public buildings construction and reconstruction; sufficiently high content of individual elements.

Metallic elements occurrences within metallic fragments in the municipal waste incineration bottom ash

Science.gov (United States)

Kowalski, Piotr; Kasina, Monika; Michalik, Marek

2017-04-01

Bottom ash (BA) from municipal solid waste incineration (MSWI) is composed of grainy ash material, residual components and metallic fragments (from few µm up to 3-5 cm). Its mineral and chemical composition is related to the composition of the waste stream in the incinerator operational area. Wide use of thermal techniques in management of solid waste makes important the studies on valuable components and their distribution within the material in terms of their further processing. By using various valorization or extraction techniques it is possible to extend the range of its possible further application. To investigate metallic elements distribution within metallic fragments of the MSWI BA material produced in municipal waste incineration plant in Poland were collected in 2015 and 2016. BA and its components were investigated using spectroscopic methods of chemical analysis: ICP-OES, ICP-MS, LECO and EDS (used for microanalysis during SEM observations). BA is a material rich in Si (22.5 wt%), Ca (13.4 wt%), Fe (4 wt%), Al (5.2 wt%) and Na (3.5 wt%), composed of equal part of amorphous (silicate glass dominated) and crystalline phase (rich in silicates, aluminosilicates, oxides of non- and metallic elements and sulphates). The content of metallic elements (Al, Fe, Mg, Ti, Mn, Cr, Ni, Sc, Mo, Cu, Pb, Zn, Sn) is 11.5 wt% with domination of Al (5.2 wt%) and Fe (4 wt%) and elevated values of Mg (1 wt%), Ti (0.54 wt%), Cu (0.26 wt%) and Zn (0.27 wt%) (Kowalski et al., 2016). They were mostly concentrated in the form of metallic fragments, mainly as metallic inclusions in the size of 1-20 µm and separated metallic grains in the size of 50-300 µm. Metallic fragments present in the BA are characterized by their composition heterogeneity and various oxygen content. Fragments are rarely composed of single metallic element and usually in their composition up to few main elements dominated over others. The most common were Fe-, Al- and Zn-rich fragments forming respectively

Rare earth elements in fly ashes created during the coal burning process in certain coal-fired power plants operating in Poland - Upper Silesian Industrial Region

International Nuclear Information System (INIS)

Smolka-Danielowska, Danuta

2010-01-01

The subject of the study covered volatile ashes created during hard coal burning process in ash furnaces, in power plants operating in the Upper Silesian Industrial Region, Southern Poland. Coal-fired power plants are furnished with dust extracting devices, electro precipitators, with 99-99.6% combustion gas extracting efficiency. Activity concentrations ofTh-232, Ra-226, K-40, Ac-228, U-235 and U-238 were measured with gamma-ray spectrometer. Concentrations of selected rare soil elements (La, Ce, Nd, Sm, Y, Gd, Th, U) were analysed by means of instrumental neutron activation analysis (INAA). Mineral phases of individual ash particles were identified with the use of scanning electron microscope equipped with EDS attachment. Laser granulometric analyses were executed with the use of Analyssette analyser. The activity of the investigated fly-ash samples is several times higher than that of the bituminous coal samples; in the coal, the activities are: 226Ra - 85.4 Bq kg -1 , 40 K-689 Bq kg -1 , 232Th - 100.8 Bq kg -1 , 235U-13.5 Bq kg -1 , 238U-50 Bq kg -1 and 228Ac - 82.4 Bq kg -1 .

Rare earth elements in fly ashes created during the coal burning process in certain coal-fired power plants operating in Poland - Upper Silesian Industrial Region.

Science.gov (United States)

Smolka-Danielowska, Danuta

2010-11-01

The subject of the study covered volatile ashes created during hard coal burning process in ash furnaces, in power plants operating in the Upper Silesian Industrial Region, Southern Poland. Coal-fired power plants are furnished with dust extracting devices, electro precipitators, with 99-99.6% combustion gas extracting efficiency. Activity concentrations ofTh-232, Ra-226, K-40, Ac-228, U-235 and U-238 were measured with gamma-ray spectrometer. Concentrations of selected rare soil elements (La, Ce, Nd, Sm, Y, Gd, Th, U) were analysed by means of instrumental neutron activation analysis (INAA). Mineral phases of individual ash particles were identified with the use of scanning electron microscope equipped with EDS attachment. Laser granulometric analyses were executed with the use of Analyssette analyser. The activity of the investigated fly-ash samples is several times higher than that of the bituminous coal samples; in the coal, the activities are: 226Ra - 85.4 Bq kg(-1), 40 K-689 Bq kg(-1), 232Th - 100.8 Bq kg(-1), 235U-13.5 Bq kg(-1), 238U-50 Bq kg(-1) and 228Ac - 82.4 Bq kg(-1).

Gas generation in incinerator ash; Gasbildning i aska

Energy Technology Data Exchange (ETDEWEB)

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

2006-02-15

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

Plant growth and trace-element uptake on acidic coal refuse amended with lime or fly ash

Energy Technology Data Exchange (ETDEWEB)

Jastrow, J.D. (Argonne National Lab., IL); Zimmerman, C.A.; Dvorak, A.J.; Hinchman, R.R.

1981-04-01

Two commonly used revegetation species, Kentucky 31 tall fescue (Festuca arundinacea Schreb.) and Lincoln smooth brome (Bromus inermis Leyss.), were grown for 60 days in pots containing coarse coal mine refuse (referred to as gob, pH = 3.5) amended with either lime or alkaline powerplant fly ash. Both species were also grown in pots containing a silt loam surface soil as a control. Morphological growth parameters were measured over time; dry weights and shoot/root ratios were determined at harvest. Concentrations of Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, V, and Zn in the plant shoots were determined by atomic absorption spectrophotometry. Plant growth of both species was not as good on either lime- or fly ash-amended gob as it was on surface soil; however, more vigorous growth occurred on lime-amended gob than on fly ash-amended gob. Significant differences (rho < 0.05) in the tissue concentrations of Cd, Co, Fe, Hg, Mn, Pb, V, and Zn were found among the plants grown on the three substrates. Except for Hg and Pb, these elements were higher in plants grown on at least one of the amended-gob substrates than in plants grown on surface soil. Significant substrate differences were not observed for Al, As, Cr, Cu, Ni, and Se. The tissue concentrations of some elements - notably Al, Cu, Fe, Mn, V, and Zn - were high enough in plants from one or more of the substrates to either approach or exceed concentrations which have been reported to be associated with toxic effects in some plant species.

Strength and Compaction Analysis of Sand-Bentonite-Coal Ash Mixes

Science.gov (United States)

Sobti, Jaskiran; Singh, Sanjay Kumar

2017-08-01

This paper deals with the strength and compaction characteristics of sand-bentonite-coal ash mixes prepared by varying percentages of sand, bentonite and coal ash to be used in cutoff walls and as a liner or cover material in landfills. The maximum dry density (MDD) and optimum moisture content (OMC) of sand-bentonite mixes and sand-bentonite-coal ash mixes were determined by conducting the standard proctor test. Also, the strength and stiffness characteristics of soil mixes were furnished using unconfined compressive strength test. The results of the study reveal influence of varying percentages of coal ash and bentonite on the compaction characteristics of the sand-bentonite-coal ash mixes. Also, validation of a statistical analysis of the correlations between maximum dry density (MDD), optimum moisture content (OMC) and Specific Gravity (G) was done using the experimental results. The experimental results obtained for sand-bentonite, sand-bentonite-ash and coal ash-bentonite mixes very well satisfied the statistical relations between MDD, OMC and G with a maximum error in the estimate of MDD being within ±1 kN/m3. The coefficient of determination (R2) ranged from 0.95 to 0.967 in case of sand-bentonite-ash mixes. However, for sand-bentonite mixes, the R2 values are low and varied from 0.48 to 0.56.

Analysis list: ash2 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available ash2 Larvae + dm3 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/ash2.1.tsv ...http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/ash2.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/ash2....10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/ash2.Larvae.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/Larvae.gml ...

Study of a large rapid ashing apparatus and a rapid dry ashing method for biological samples and its application

International Nuclear Information System (INIS)

Jin Meisun; Wang Benli; Liu Wencang

1988-04-01

A large rapid-dry-ashing apparatus and a rapid ashing method for biological samples are described. The apparatus consists of specially made ashing furnace, gas supply system and temperature-programming control cabinet. The following adventages have been showed by ashing experiment with the above apparatus: (1) high speed of ashing and saving of electric energy; (2) The apparatus can ash a large amount of samples at a time; (3) The ashed sample is pure white (or spotless), loose and easily soluble with few content of residual char; (4) The fresh sample can also be ashed directly. The apparatus is suitable for ashing a large amount of the environmental samples containing low level radioactivity trace elements and the medical, food and agricultural research samples

Mixtures of coal ash and compost as substrates for highbush blueberry

Energy Technology Data Exchange (ETDEWEB)

Black, B.L.; Zimmerman, R.H. [ARS, Beltsville, MD (USA). USDA Henry A Wallace Beltsville Agriculture Research Center, Fruit Lab.

2002-07-01

Bottom ash from a coal-fired power plant and two composts were tested as components of soil-free media and as soil amendments for growing highbush blueberry (Vaccinium corymbosum L.). Combinations of ash and compost were compared to Berryland sand, and Manor clay loam, and compost amended Manor clay loam. The pH of all treatment media was adjusted to 4.5 with sulfur at the beginning of the experiment. In 1997, plants of 'Bluecrop' and 'Sierra' were planted in 15-dm{sup 3} pots containing the pH-adjusted treatment media. The first substantial crop was harvested in 1999. At the end of the 1999 season, one half of the plants were destructively harvested for growth analysis. The remaining plants were cropped again in 2000. Yield and fruit size data were collected in both seasons, and leaf and fruit samples were collected in 1999 for elemental analysis. The presence of coal ash or composted biosolids in the media had no detrimental effect on leaf or fruit elemental content. Total growth and yield of both cultivars was reduced in clay loam soil compared to Berryland sand, whereas growth and yield of plants in coal ash-compost was similar to or exceeded that of plants in Berryland sand.

Dynamic evaluation of municipal solid waste ash leachate

International Nuclear Information System (INIS)

Theis, T.L.; Gardner, K.H.

1992-01-01

The incineration of municipal solid waste (MSW) produces ashes which are concentrated in many inorganic species. The release of toxic elements from the ash to the aqueous environment is of concern as present methods of ash disposal consist primarily of landfilling. It was the goal of this paper to achieve an understanding of the mechanisms by which elements are transported from the solid ash phase to the aqueous phase. Twelve ash samples were collected from six different incinerators with varying designs and capacities. The leaching experiments were conducted using small (mini) dynamic columns to investigate the variation of leachate chemical characteristics with time. In analyzing the data, a multicomponent chemical equilibrium model was used to determine chemical speciation and component activities. Auxiliary experiments included an array of physical measurements, and aqueous batch leach tests

Quantification of Release of Critical Elements, Formation of Fly Ash and Aerosols: Status on Current Understanding and Research Needs

DEFF Research Database (Denmark)

Jappe Frandsen, Flemming

2017-01-01

Deposit formation in utility boilers occurs via a number of consecutive steps; 1) release of critical elements like K, Na, Pb, Zn, S and Cl, 2) formation of gaseous species, fly ash and aerosols, 3) transport and adhesion of ash species, 4) deposit build-up and consolidation, and, finally, 5...... formation (slagging and fouling) on superheater tubes, leading to a potential reduction in heat transfer efficiency to the water/steam cycle, or, to chemical attack (corrosion) or physical wear (erosion) of superheater tubes. These problems may give rise to irregular operation, or even costly shutdowns...... of combustion units.Through several years, high quality research has been conducted on characterization of fuels, ashes and deposit formation in utility boilers fired with coal, biomass and waste fractions. Huge amounts of experimental data have been reported, from such work, but the fact...

Radioactivity of wood ash

International Nuclear Information System (INIS)

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 -1 , in decreasing order: 137 Cs, 40 K, 90 Sr, 210 Pb, 226 Ra, 232 Th, 134 Cs, 235 U. In bott radionuclide contents decreased in the same order as in fly ash, but were smaller, and 210 Pb was hardly detectable. The NH 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.)

Optimization of soil stabilization with class C fly ash.

Science.gov (United States)

1987-01-01

Previous Iowa DOT sponsored research has shown that some Class : C fly ashes are cementitious (because calcium is combined as calcium : aluminates) while other Class C ashes containing similar amounts of : elemental calcium are not (1). Fly ashes fro...

Chemical composition of overland flow produced on soils covered with vegetative ash

Directory of Open Access Journals (Sweden)

M.B. Bodí

2013-05-01

Full Text Available The objective of this study was to ascertain the differences between the soluble elements of ash obtained under laboratory conditions and the dissolved in overland flow from soils covered with a layer of ash. The overland flow was obtained during series of rainfall simulations over soils covered with two different types of ash. This study indicates that the soluble elements released from ash can modify water quality increasing its pH, electrical conductivity and especially cation content. The nutrients solubilised are not necessarily the same as the elemental composition of ash itself. Runoff composition depends on the volume of water produced, on the solubility of the ash components and on the chemical interactions with water from rainfall and soil. After the first intense rain event, most of the elements are solubilised and lixiviated or washed out, however, some of them may increase in the runoff or soil water some weeks later due to chemical interactions with water from rainfall and soil nutrients.

Leaching characteristics of rare metal elements and chlorine in fly ash from ash melting plants for metal recovery.

Science.gov (United States)

Jung, Chang-Hwan; Osako, Masahiro

2009-05-01

In terms of resource recovery and environmental impact, melting furnace fly ash (MFA) is attracting much attention in Japan due to its high metal content. The study aims to obtain fundamental information on using a water extraction method not only to concentrate valuable rare metals but also to remove undesirable substances such as chlorine for their recovery from MFA. The composition and leaching characteristics of MFA was investigated. The results revealed that the metal content in MFA is nearly equal to raw ore quality. The content of Ag, In, Pd, Pb, and Zn is, in fact, higher than the content of raw ore. As for leaching behavior, Ag, Bi, In, Ga, Ge, Sb, Sn, and Te showed the lowest release at a neutral pH range. Pd was leached constantly regardless of pH, but its concentration was quite low. On the other hand, most of the Tl was easily leached, revealing that water extraction is not appropriate for Tl recovery from MFA. Major elements Cl, Ca, Na, and K, occupying about 70% of MFA, were mostly leached regardless of pH. Base metal elements Cu, Pb, and Zn showed minimum solubility at a neutral pH. The leaching ratio of target rare metal elements and base metal elements suggests that the optimal pH for water extraction is 8-10, at which the leaching concentration is minimized. The water extraction process removed most of the Cl, Ca, Na, and K, and the concentration of rare metals and base metals increased by four or five times.

Geochemistry of coals, coal ashes and combustion wastes from coal-fired power stations

International Nuclear Information System (INIS)

Vassilev, S.V.; Vassileva, C.G.

1997-01-01

Contents, concentration trends, and modes of occurrence of 67 elements in coals, coal ashes, and combustion wastes at eleven Bulgarian thermoelectric power stations (TPS) were studied. A number of trace elements in coal and coal ash have concentrations greater than their respective worldwide average contents (Clarke values). Trace elements are concentrated mainly in the heavy accessory minerals and organic matter in coal. In decreasing order of significance, the trace elements in coal may occur as: element-organic compounds; impurities in the mineral matter; major components in the mineral matter; major and impurity components in the inorganic amorphous matter; and elements in the fluid constituent. A number of trace elements in the waste products, similar to coal ashes, exceed known Clarke contents. Trace elements are mainly enriched in non-magnetic, heavy and fine-grained fractions of fly ash. They are commonly present as impurities in the glass phases, and are included in the crystalline components. Their accessory crystalline phases, element-organic compounds, liquid and gas forms, are of subordinate importance. Some elements from the chalcophile, lithophile and siderophile groups may release into the atmosphere during coal burning. For others, the combustion process appears to be a powerful factor causing their relative enrichment in the fly ash and rarely in the bottom ash and slag. 65 refs., 1 fig., 11 tabs

Oil sludge treatment using thermal and ash vitrification technology

International Nuclear Information System (INIS)

Rohyiza Baan; Sharifah Aishah, S.A.K.; Mohamad Puad Abu; Mohd Abdul Wahab Yusof

2010-01-01

In this paper, an experimental study of crude oil sludge terminal for volume reduction and radionuclide stability was treated by using integrated thermal treatment system. The pre-thermal treatment of oil sludge was carried out in fluidized bed combustor at temperature 500 degree Celsius, and then the ash produced from that process was vitrified in high temperature furnace at temperature above 1000 degree Celsius. The main contents of oil sludge are composed of 80% carbon, 11% sulphur, 50% volatile matter and 30% ash. The high heating value was 35,722 kJ/ kg. Analysis by gamma spectrometer was showed the radionuclide as Ra-226 (52.23 Bq/ kg), Ra-228 (47.48 Bq/ kg), K-40 (172.55 Bq/ kg), whereas analysis by neutron activation analysis (NAA) for U (0.5 μg/ g) and Th (0.5 μg/ g) was present in low concentration. Trace elements as Ba, Cd, Cr, Hg, As, Pb, Al, Zn, Ni was determine by using ICPMS. Thermal analysis has shown loss of mass and residual decomposition in the TG and DTA curves. The concentration of radionuclide in ash from fluidized bed combustor process was increased for Ra-226 (264.27 Bq/ kg) and Ra-228 (253.77 Bq/ kg). The slag was produced from ash vitrification process was characterized by X-ray fluorescence (XRF) and showed that silica oxide and potassium oxide were found. The slag characterization by X-ray diffraction (XRD) showed that slag composed of crystalline. The toxicity characteristic leaching procedure (TCLP) test showed that the slag resulted in very low leachability of heavy metals. Most of the toxic metals are fixed in the vitrification process and the leachate values meet the standard level of Malaysian Department of Environmental (DOE) of hazardous materials. The average concentration of each element varied between 1.5-14.0 mg/ kg. (author)

Analysis list: ash-2 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available ash-2 Adult,Embryo + ce10 http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/target/as...h-2.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/target/ash-2.5.tsv http://dbarchive.biosciencedbc....jp/kyushu-u/ce10/target/ash-2.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/colo/ash-2.Adult.tsv,http://dbarchive.bioscience...dbc.jp/kyushu-u/ce10/colo/ash-2.Embryo.tsv http://dbarchive.bioscience...dbc.jp/kyushu-u/ce10/colo/Adult.gml,http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/colo/Embryo.gml ...

Trace element emissions from coal

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-09-15

Trace elements are emitted during coal combustion. The quantity, in general, depends on the physical and chemical properties of the element itself, the concentration of the element in the coal, the combustion conditions and the type of particulate control device used, and its collection efficiency as a function of particle size. Some trace elements become concentrated in certain particle streams following combustion such as bottom ash, fly ash, and flue gas particulate matter, while others do not. Various classification schemes have been developed to describe this partitioning behaviour. These classification schemes generally distinguish between: Class 1: elements that are approximately equally concentrated in the fly ash and bottom ash, or show little or no fine particle enrichment, examples include Mn, Be, Co and Cr; Class 2: elements that are enriched in the fly ash relative to bottom ash, or show increasing enrichment with decreasing particle size, examples include As, Cd, Pb and Sb; Class 3: elements which are emitted in the gas phase (primarily Hg (not discussed in this review), and in some cases, Se). Control of class 1 trace elements is directly related to control of total particulate matter emissions, while control of the class 2 elements depends on collection of fine particulates. Due to the variability in particulate control device efficiencies, emission rates of these elements can vary substantially. The volatility of class 3 elements means that particulate controls have only a limited impact on the emissions of these elements.

Spectral analysis of white ash response to emerald ash borer infestations

Science.gov (United States)

Calandra, Laura

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

Modeling of Cementitious Representative Volume Element with Additives

Science.gov (United States)

Shahzamanian, M. M.; Basirun, W. J.

CEMHYD3D has been employed to simulate the representative volume element (RVE) of cementitious systems (Type I cement) containing fly ash (Class F) through a voxel-based finite element analysis (FEA) approach. Three-dimensional microstructures composed of voxels are generated for a heterogeneous cementitious material consisting of various constituent phases. The primary focus is to simulate a cementitious RVE containing fly ash and to present the homogenized macromechanical properties obtained from its analysis. Simple kinematic uniform boundary conditions as well as periodic boundary conditions were imposed on the RVE to obtain the principal and shear moduli. Our current work considers the effect of fly ash percentage on the elastic properties based on the mass and volume replacements. RVEs with lengths of 50, 100 and 200μm at different degrees of hydration are generated, and the elastic properties are modeled and simulated. In general, the elastic properties of a cementitious RVE with fly ash replacement for cement based on mass and volume differ from each other. Moreover, the finite element (FE) mesh density effect is studied. Results indicate that mechanical properties decrease with increasing mesh density.

The dissolution kinetics of major elements in municipal solid waste incineration bottom ash particles

Science.gov (United States)

Bendz, David; Tüchsen, Peter L.; Christensen, Thomas H.

2007-12-01

Leaching and tracer experiments in batches at L/S 20 were performed with 3-month-old MSWI bottom ash separated into eight different particle sizes. The time-dependent leaching of major elements (Ca 2+, K +, Na +, Cl - and SO 4- 2 ) was monitored for up to 747 h. Physical properties of the particles, the specific surface (BET), pore volume and pore volume distribution over pore sizes (BJH) were determined for all particle classes by N 2 adsorption/desorption experiments. Some common features of physical pore structure for all particles were revealed. The specific surface and the particle pore volume were found to be negatively correlated with particle size, ranging from 3.2 m 2/g to 25.7 m 2/g for the surface area and from 0.0086 cm 3/g to 0.091 cm 3/g for the pore volume. Not surprisingly, the specific surface area was found to be the major material parameter that governed the leaching behavior for all elements (Ca 2+, K +, Na +, Cl - and SO 4- 2 ) and particle sizes. The diffusion resistance was determined independently by separate tracer (tritium) experiments. Diffusion gave a significant contribution to the apparent leaching kinetics for all elements during the first 10-40 h (depending on the particle size) of leaching and surface reaction was the overall rate controlling mechanism at late times for all particle sizes. For Ca 2+ and SO 4- 2 , the coupled effect of diffusion resistance and the degree of undersaturation in the intra particle pore volume was found to be a major rate limiting dissolution mechanism for both early and late times. The solubility control in the intra particulate porosity may undermine any attempt to treat bottom ash by washing out the sulfate. Even for high liquid/solid ratios, the solubility in the intra-particular porosity will limit the release rate.

Investigation of the possibility of binding fly ash particles by elemental sulphur

Directory of Open Access Journals (Sweden)

Vidojković V.

2006-01-01

Full Text Available Thermal power plants in Serbia use lignite for electrical power production The secondary product of coal combustion is fly ash in the amount of 17%. Fly ash causes the pollution of air, water and soil, and also cause many human, especially lung diseases. Secondary sulphur is a product of crude oil refining. The aim of this study was to investigate the use of sulphur as a bonding material in ultra fine particle agglomeration (smaller than 63 μm in fly ash. The agglomeration should make the ash particles larger and heavy enough to fall without flying fractions. The experiments showed that during the homogenization of the ashes and sulphur from 150 to 170 °C in a reactor with intensive mixing, an amount of 15% sulphur was sufficient to bond particles and cause agglomeration without visible flying fractions.

On stream ash analysis of coal based on its natural gamma-ray activity

International Nuclear Information System (INIS)

Mathew, P.J.

1986-01-01

A novel method based on the natural gamma-ray activity of coal has been developed for the on-stream determination of ash. The accuracy of the method has been verified by measuring the natural gamma-ray activity and ash content of coal samples from a number of locations in New Zealand and Australia. The rms differences between % ash by ignition and % ash by the gamma-ray method ranged from 0.65% ash for coal samples from a Queensland mine to 1.6% ash for samples from a southern New South Wales mine. The rms errors include those to geovariance, and due to sampling and sample analysis by conventional means. The error in ash measurement by the gamma-ray method can therefore be reduced by substantially eliminating these errors. A prototype ash analyser was also developed and field-tested at the Huntly East mine. In a four-week test, the prototype gauge was used to determine the ash content of run-of-mine (rom) coal below 20% ash to within +- 1.7% ash. Laboratory studies of coal samples collected during the field test of the prototype gave an error of 0.8% ash for coal samples below 20% ash content. A higher error was observed in the field test compared with laboratory data, and the difference is attributed to errors in sampling from the conveyor belt

Reduction of metal leaching in brown coal fly ash using geopolymers

International Nuclear Information System (INIS)

Bankowski, P.; Zou, L.; Hodges, R.

2004-01-01

Current regulations classify fly ash as a prescribed waste and prohibit its disposal in regular landfill. Treatment of the fly ash can reduce the leach rate of metals, and allow it to be disposed in less prescribed landfill. A geopolymer matrix was investigated as a potential stabilisation method for brown coal fly ash. Precipitator fly ash was obtained from electrostatic precipitators and leached fly ash was collected from ash disposal ponds, and leaching tests were conducted on both types of geopolymer stabilised fly ashes. The ratio of fly ash to geopolymer was varied to determine the effects of different compositions on leaching rates. Fourteen metals and heavy metals were targeted during the leaching tests and the results indicate that a geopolymer is effective at reducing the leach rates of many metals from the fly ash, such as calcium, arsenic, selenium, strontium and barium. The major element leachate concentrations obtained from leached fly ash were in general lower than that of precipitator fly ash. Conversely, heavy metal leachate concentrations were lower in precipitator fly ash than leached pond fly ash. The maximum addition of fly ash to this geopolymer was found to be 60 wt% for fly ash obtained from the electrostatic precipitators and 70 wt% for fly ash obtained from ash disposal ponds. The formation of geopolymer in the presence of fly ash was studied using 29Si MAS-NMR and showed that a geopolymer matrix was formed. X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) imaging showed the interaction of the fly ash with the geopolymer, which was related to the leachate data and also the maximum percentage fly ash addition

Magmatic and fragmentation controls on volcanic ash surface chemistry

Science.gov (United States)

Ayris, Paul M.; Diplas, Spyros; Damby, David E.; Hornby, Adrian J.; Cimarelli, Corrado; Delmelle, Pierre; Scheu, Bettina; Dingwell, Donald B.

2016-04-01

The chemical effects of silicate ash ejected by explosive volcanic eruptions on environmental systems are fundamentally mediated by ash particle surfaces. Ash surfaces are a composite product of magmatic properties and fragmentation mechanisms, as well as in-plume and atmospheric alteration processes acting upon those surfaces during and after the eruption. Recent attention has focused on the capacity of alteration processes to shape ash surfaces; most notably, several studies have utilised X-ray photoelectron spectroscopy (XPS), a technique probing the elemental composition and coordination state of atoms within the top 10 nm of ash surfaces, to identify patterns of elemental depletions and enrichments relative to bulk ash chemical composition. Under the presumption of surface and bulk equivalence, any disparities have been previously attributed to surface alteration processes, but the ubiquity of some depletions (e.g., Ca, Fe) across multiple ash studies, irrespective of eruptive origin, could suggest these to be features of the surface produced at the instant of magma fragmentation. To investigate this possibility further, we conducted rapid decompression experiments at different pressure conditions and at ambient and magmatic temperature on porous andesitic rocks. These experiments produced fragmented ash material untouched by secondary alteration, which were compared to particles produced by crushing of large clasts from the same experiments. We investigated a restricted size fraction (63-90 μm) from both fragmented and crushed materials, determining bulk chemistry and mineralogy via XRF, SEM-BSE and EPMA, and investigated the chemical composition of the ash surface by XPS. Analyses suggest that fragmentation under experimental conditions partitioned a greater fraction of plagioclase-rich particles into the selected size fraction, relative to particles produced by crushing. Trends in surface chemical composition in fragmented and crushed particles mirror that

Method of reversibly immobilizing sulfate ash

International Nuclear Information System (INIS)

Greenhalgh, W.O.

1984-01-01

A sulphate ash at least 20% by weight of which consists of sulphates of transuranic elements is immobilised by heating to melting a mixture of the ash, a metal, and a fluxing agent; the metal used is Al, Ce, Sm, Eu or mixtures thereof and it is used in an amount sufficient to reduce the transuranic sulphates in the ash to metal and form an alloy with the metal so produced; sufficient of the fluxing agent is used to reduce the percentage of transuranic sulphates in the mix to form 1% to 10% of the mix and the molten mixture is cooled and the alloy containing the immobilised ash separated. (author)

Abundances and distribution of minerals and elements in high-alumina coal fly ash from the Jungar Power Plant, Inner Mongolia, China

Science.gov (United States)

Dai, S.; Zhao, L.; Peng, S.; Chou, C.-L.; Wang, X.; Zhang, Y.; Li, D.; Sun, Y.

2010-01-01

The fly ash from the Jungar Power Plant, Inner Mongolia, China, is unique because it is highly enriched in alumina (Al2O3>50%). The fly ash mainly consists of amorphous glass and mullite and trace amounts of corundum, quartz, char, calcite, K-feldspar, clay minerals, and Fe-bearing minerals. The mullite content in fly ash is as high as 37.4% because of high boehmite and kaolinite contents in feed coal. Corundum is a characteristic mineral formed during the combustion of boehmite-rich coal.Samples from the economizer were sieved into six size fractions (500 mesh) and separated into magnetic, mullite+corundum+quartz (MCQ) and glass phases for mineralogical and chemical analysis. The corundum content increases but amorphous glass decreases with decreasing particle size. Fractions of small particle sizes are relatively high in mullite, probably because mullite was formed from fine clay mineral particles under high-temperature combustion condition. Similarly, fine corundum crystals formed in the boiler from boehmite in feed coal. The magnetic phase consists of hematite, magnetite, magnesioferrite, and MgFeAlO4 crystals. The MCQ phase is composed of 89% mullite, 6.1% corundum, 4.5% quartz, and 0.5% K-feldspar.Overall, the fly ash from the power plant is significantly enriched in Al2O3 with an average of 51.9%, but poor in SiO2, Fe2O3, CaO, MgO, Na2O, P2O5, and As. Arsenic, TiO2, Th, Al2O3, Bi, La, Ga, Ni, and V are high in mullite, and the magnetic matter is enriched in Fe2O3, CaO, MnO, TiO2, Cs, Co, As, Cd, Ba, Ni, Sb, MgO, Zn, and V. The remaining elements are high in the glass fraction. The concentration of K2O, Na2O, P2O5, Nb, Cr, Ta, U, W, Rb, and Ni do not clearly vary with particle size, while SiO2 and Hg decrease and the remaining elements clearly increase with decreasing particle size. ?? 2009 Elsevier B.V.

Characterization of coal fly ash components by laser-induced breakdown spectroscopy

International Nuclear Information System (INIS)

Ctvrtnickova, Tereza; Mateo, Mari-Paz; Yanez, Armando; Nicolas, Gines

2009-01-01

The high sensitivity of laser-induced breakdown spectroscopy (LIBS) for the detection of most of the fly ash components enables the analysis of these residues produced during the combustion of coal. Fly ash consists of oxides (SiO 2 , Al 2 O 3 , Fe 2 O 3 , CaO...) and unburnt carbon which is the major determinant of combustion efficiency in coal fired boilers. For example, an excessive amount of residual carbon dispersed in the fly ash means a significant loss of energy (Styszko et al., 2004). Standard methods employed for the analysis of fly ash make not possible a control of boiler in real time. LIBS technique can significantly reduce the time of analysis, in some cases even an online detection can be performed. For this reason, some studies have been addressed in order to demonstrate the capability of the laser-induced breakdown spectroscopy technique for the detection of carbon content in high pressure conditions typical of thermal power plants (Noda et al., 2002) and for the monitoring of unburnt carbon for the boiler control in real time (Kurihara et al., 2003). In particular, the content of unburnt carbon is a valuable indicator for the control of fly ash quality and for the boiler combustion. Depending on this unburnt carbon content, fly ash can be disposed as an industrial waste or as a raw material for the production of concrete in the construction sector. In this study, analyses were performed on specimens of various forms of preparation. Pressed pellets were prepared with two different binders. Presented results concern the nature and amount of the binder used to pelletize the powder, and the laser-induced breakdown spectroscopy parameters and procedure required to draw calibration curves of elements from the fly ash. Analysis 'on tape' was performed in order to establish the experimental conditions for the future 'online analysis'.

Biomass ash utilization

Energy Technology Data Exchange (ETDEWEB)

Bristol, D.R.; Noel, D.J.; O`Brien, B. [HYDRA-CO Operations, Inc., Syracuse, NY (United States); Parker, B. [US Energy Corp., Fort Fairfield, ME (United States)

1993-12-31

This paper demonstrates that with careful analysis of ash from multiple biomass and waste wood fired power plants that most of the ash can serve a useful purpose. Some applications require higher levels of consistency than others. Examples of ash spreading for agricultural purposes as a lime supplement for soil enhancement in Maine and North Carolina, as well as a roadbase material in Maine are discussed. Use of ash as a horticultural additive is explored, as well as in composting as a filtering media and as cover material for landfills. The ash utilization is evaluated in a framework of environmental responsibility, regulations, handling and cost. Depending on the chemical and physical properties of the biomass derived fly ash and bottom ash, it can be used in one or more applications. Developing a program that utilizes ash produced in biomass facilities is environmentally and socially sound and can be financially attractive.

Analysis list: Ash2l [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available Ash2l Blood + mm9 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Ash2l.1.tsv... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Ash2l.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Ash2...l.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Ash2l.Blood.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Blood.gml ...

Prospects for ash pond reclamation

Energy Technology Data Exchange (ETDEWEB)

Shyyam, A.K.; Shukla, K.S.; Agrawal, D. (National Thermal Power Corporation Ltd., New Delhi (India))

1993-01-01

A typical modern coal fired station in India burns 0.7 t/MWh of coal and consequently generates ash at 0.245 t/MWh. The physical nature of ash, low available concentrations of certain plant nutrients and the presence of phytotoxic trace elements render fly ash marginally adequate for plant growth. As fly ash itself was thought to be an inappropriate growth medium for plants, regulators decided that a soil cover is mandatory. There is ample data to suggest that the attributes of fly ash detrimental to plant growth can be ameliorated, allowing the establishment of vegetation directly on fly ash surfaces. The natural revegetation of fly ash disposal sites has been reported in the world. The natural vegetation pioneered by Cynodon at different stages of ecological succession and comprising of species such as [ital Calotropis gigantea], [ital Lippia nodiflora], [ital Ipomea, cornea], [ital Xanthium parviflorum] has been noted at one of the NTPC projects, in Badarpur Thermal Power Station. Since natural reclamation is a time-consuming process, experimental trials of growing some species over the temporary ash lagoon directly (without soil cover) were carried out at Ramagundam Super Thermal Power Project (RSTPP) of NTPC, in South India to achieve faster results than the natural process. 6 refs., 8 figs.

Effects of a low severity prescribed fire on water-soluble elements in ash from a cork oak (Quercus suber) forest located in the northeast of the Iberian Peninsula

Science.gov (United States)

Pereira, P.; beda, X.; Martin, D.; Mataix-Solera, J.; Guerrero, C.

2011-01-01

Wildfire is the major disturbance in Mediterranean forests. Prescribed fire can be an alternative to reduce the amount of fuel and hence decrease the wildfire risk. However the effects of prescribed fire must be studied, especially on ash properties, because ash is an important nutrient source for ecosystem recovery. The aim of this study is to determine the effects of a low severity prescribed fire on water-soluble elements in ash including pH, electrical conductivity (EC), calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), aluminum (Al), manganese (Mn), iron (Fe), zinc (Zn), silica (SiO2) and total sulphur (TS). A prescribed fire was conducted in a cork oak (Quercus suber) (Q.S) forest located in the northeast part of the Iberian Peninsula. Samples were collected from a flat plot of 40??70m mainly composed of Q.S and Quercus robur (Q.R) trees. In order to understand the effects of the prescribed fire on the soluble elements in ash, we conducted our data analysis on three data groups: all samples, only Q.S samples and only Q.R samples. All three sample groups exhibited a significant increase in pH, EC (p<0.001), water-soluble Ca, Mg, Na, SiO2 and TS and a decrease in water-soluble Mn, Fe and Zn. Differences were identified between oak species for water-soluble K, Al and Fe. In Q.S samples we registered a significant increase in the first two elements p<0.001 and p<0.01, respectively, and a non-significant impact in the third, at p<0.05. In Q.R data we identified a non-significant impact on water-soluble K and Al and a significant decrease in water-soluble Fe (p<0.05). These differences are probably due to vegetation characteristics and burn severity. The fire induced a higher variability in the ash soluble elements, especially in Q.S samples, that at some points burned with higher severity. The increase of pH, EC, Ca, Mg, Na and K will improve soil fertility, mainly in the study area where soils are acidic. The application of this low severity prescribed

Direct-reading spectrochemical analysis of soils and plant ashes

International Nuclear Information System (INIS)

Roca, M.; Alvarez, F.; Cellini, R. F.; Burriel, F.

1966-01-01

Two different techniques haves been tried to determine trace elements in soils and plant ashes using a direct reading spectrometer :1) the samples are mixed with graphite powder and excited on 2x4 mm graphite rods with a 13 amperes direct current arc: 2) a mixture of graphite and strontium carbonate is used as spectrochemical buffer, and 2x6 mm cup graphite rods in a 10 amperes direct current arc. We have studies the influence of sodium, potassium and calcium on the results. (Author)

A Comparative study Of Catalityc Activity Of Heterogeneous Base Of Banana Stem Ash And Fly Ash On Production Of Biodiesel Byultrasonic

OpenAIRE

Marlinda; Ramli; Muh. Irwan

2015-01-01

Abstract The use of heterogeneous catalysts in the production of biodiesel provides many advantages due to heterogeneous catalysts can be easily separated from the product so that it can be reused. This research using heterogeneous catalysts derived from natural materials namely banana stem ash and coal fly ash containing alkali and alkaline earth elements. The preparation of catalyst from banana stem ash and coal fly ash used activator KOH 1.9 N and impregnation with KNO3 15 and then heated...

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.

Fly ash dynamics in soil-water systems

International Nuclear Information System (INIS)

Sharma, S.; Fulekar, M.H.; Jayalakshmi, C.P.

1989-01-01

Studies regarding the effluents and coal ashes (or fly ash) resulting from coal burning are numerous, but their disposal and interactions with the soil and water systems and their detailed environmental impact assessment with concrete status reports on a global scale are scanty. Fly ash dynamics in soil and water systems are reviewed. After detailing the physical composition of fly ash, physicochemical changes in soil properties due to fly ash amendment are summarized. Areas covered include texture and bulk density, moisture retention, change in chemical equilibria, and effects of fly ash on soil microorganisms. Plant growth in amended soils is discussed, as well as plant uptake and accumulation of trace elements. In order to analyze the effect of fly ash on the physicochemical properties of water, several factors must be considered, including surface morphology of fly ash, pH of the ash sluice water, pH adjustments, leachability and solubility, and suspended ash and settling. The dynamics of fly ash in water systems is important due to pollution of groundwater resources from toxic components such as trace metals. Other factors summarized are bioaccumulation and biomagnification, human health effects of contaminants, and the impact of radionuclides in fly ash. Future research needs should focus on reduction of the environmental impact of fly ash and increasing utilization of fly ash as a soil amendment. 110 refs., 2 figs., 10 tabs

Metallic elements fractionation in municipal solid waste incineration residues

Science.gov (United States)

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

2016-04-01

Municipal solid waste incineration (MSWI) residues are represented by three main materials: bottom ash, fly ash and air pollution control (APC) residues. Among them ˜80 wt% is bottom ash. All of that materials are products of high temperature (>1000° C) treatment of waste. Incineration process allows to obtain significant reduction of waste mass (up to 70%) and volume (up to 90%) what is commonly used in waste management to reduce the amount need to be landfilled or managed in other way. Incineration promote accumulation non-combustible fraction of waste, which part are metallic elements. That type of concentration is object of concerns about the incineration residues impact on the environment and also gives the possibility of attempts to recover them. Metallic elements are not equally distributed among the materials. Several factors influence the process: melting points, volatility and place and forms of metallic occurrence in the incinerated waste. To investigate metallic elements distribution in MSWI residues samples from one of the biggest MSW incineration plant in Poland were collected in 2015. Chemical analysis with emphasis on the metallic elements content were performed using inductively coupled plasma optical emission (ICP-OES) and mass spectrometry (ICP-MS). The bottom ash was a SiO2-CaO-Al2O3-Fe2O3-Na2O rich material, whereas fly ash and APC residues were mostly composed of CaO and SiO2. All of the materials were rich in amorphous phase occurring together with various, mostly silicate crystalline phases. In a mass of bottom ash 11 wt% were metallic elements but also in ashes 8.5 wt% (fly ash) and ˜4.5 wt% (APC residues) of them were present. Among the metallic elements equal distribution between bottom and fly ash was observed for Al (˜3.85 wt%), Mn (770 ppm) and Ni (˜65 ppm). In bottom ash Fe (5.5 wt%), Cr (590 ppm) and Cu (1250 ppm) were concentrated. These values in comparison to fly ash were 5-fold higher for Fe, 3-fold for Cu and 1.5-fold for

Importance of nanoparticles and colloids from volcanic ash for riverine transport of trace elements to the ocean: evidence from glacial-fed rivers after the 2010 eruption of Eyjafjallajökull Volcano, Iceland.

Science.gov (United States)

Tepe, Nathalie; Bau, Michael

2014-08-01

Volcanic ashes are often referenced as examples for natural nanoparticles, yet the particle size distribution eruptions at Eyjafjallajökull in 2010. In addition to the dissolved concentrations of rare earth elements (REE), Zr, Hf, Nb, and Th in the 450 nm-filtered waters, we also studied the respective filter residues (river particulates >450 nm) and volcanic ash. In spite of the low solubilities and high particle-reactivities of the elements studied, most water samples show high dissolved concentrations, such as up to 971 ng/kg of Ce and 501 ng/kg of Zr. Except for the pure glacial meltwater and glacial base flow, all waters display the same shale-normalized REE patterns with pronounced light and heavy REE depletion and positive Eu anomalies. While such patterns are unusual for river waters, they are similar to those of the respective river particulates and the volcanic ash, though at different concentration levels. The distribution of dissolved Zr, Hf, Nb, and Th in the waters also matches that of filter residues and ash. This strongly suggests that in all 450 nm-filtered river waters, the elements studied are associated with solid ash particles smaller than 450 nm. This reveals that volcanic ash-derived nanoparticles and colloids are present in these glacial-fed rivers and that such ultrafine particles control the trace element distribution in the surface runoff. Subsequent to explosive volcanic eruptions, these waters provide terrigenous input from landmasses to estuaries, that is characterized by a unique trace element signature and that subsequent to modification by estuarine processes delivers a pulse of nutrients to coastal seawater in regions not affected by plume fall-out. Copyright © 2014 Elsevier B.V. All rights reserved.

Elemental analysis of atmospheric aerosols in Gaborone

African Journals Online (AJOL)

ELO

amount more than 90% were copper, lead, nickel and gold. Key words: Atmospheric particles, elements, ... Selebi-Phikwe area, gold and nickel in Francis town and soda ash in Sowa. Gaborone is the capital of ... a stub three times a week with an exposure time of four hours. The exposed stubs were collected and kept ...

Neutron activation analysis for environmental trace element research determination of elemental composition of sediments in the Sea of Galillee, Israel

Energy Technology Data Exchange (ETDEWEB)

Lavi, N; Ne` eman, E; Brenner, S; Butenko, V [Tel Aviv Univ. (Israel). Medical School

1996-12-01

The aims of this work were to: a) demonstrate the effectiveness of instrumental neutron activation analysis for determining the background concentrations of trace elements in the sediments collected from the Sea of Gallile. b) determine the advantage factors for epithermal neutron irradiation. c) determine the contribution of silicon to the total {sup 28}Al activity by the {sup 28}Si(n,p){sup 28}Al reaction. c) check the validity of the method by determining the elemental content of U.S. NBS Standard Reference Material SRM-1633a (fly ash). d) calculate the average enrichment factors for the elements in sediments . e) determine the concentrations of the artificial radionuclides {sup 134}Cs, {sup 137}Cs and the naturally occurring radionuclides {sup 40}K, {sup 226}Ra and {sup 232}Th (authors).

Studies of lagoon ash from Sarawak to assess the impact on the environment

Energy Technology Data Exchange (ETDEWEB)

Prabir Kumar Kolay; Harwant Singh [University Malaysia Sarawak, Sarawak (Malaysia). Dept. of Civil Engineering

2010-02-15

Coal utilization, mainly in thermal power plants, has increased significantly from 4.2 to 13 million tonnes within 2000 to 2005, which resulted in the production of approximately 2 million tonnes of coal ash in Malaysia. Of this only a small percentage is used as a cement ingredient, in concrete industry, as a fill material, etc. and with the rest of the amount being disposed in ash ponds or lagoons. If the lagoons are not properly designed with a landfill liner or if there is spillage from the ash pond, the toxic heavy metal present in coal ash can result in the contamination of the subsurface soil and the ground water. The concentration of heavy metals or trace elements in coal residues depends on the composition of a particular parent coal and the bulk utilization of lagoon ash for various purposes requires a complete characterization of the ash. Hence, this paper analyzes the coal ash for its trace element content and characterizes mainly physical, chemical, mineralogical, morphological and thermal properties of the lagoon ash from a local coal based thermal power plant from Sarawak, Malaysia. The results also indicated that, the concentration of some trace elements is quite high from the environmental perspective in this particular lagoon ash. 43 refs., 4 figs., 4 tabs.

Assessment of the radiation field from radioactive elements in a wood-ash-treated coniferous forest in southwest Sweden

International Nuclear Information System (INIS)

Ravila, A.; Holm, E.

1996-01-01

The distribution of natural and antrophogenic radioactive elements in soil and wood was investigated in a 30-year-old forest stand of Norway spruce. Forest plots treated with a single dose of granulated wood ash in 1989 were compared with untreated control plots. It was observed that the retention of radiocesium and radiostrontium by the forest soil is rather strong in spite of the high annual precipitation (1100 mm a -1 ) and the relatively acidic conditions of the soil. Most of the deposited nuclear weapon fall-out of radiocesium and radiostrontium is still residing in the forest soil. Radiostrontium, but not radiocesium, was found in the intrasoil water collected with lysimeters at soil depths of 20 and 50 cm. Wood xylem radial distributions of radiostrontium indicated a decreased bioavailability with time after deposition of nuclear weapons fall-out, and no major differences could be observed on comparison of wood from ash-treated plots with wood from untreated plots. The activity concentration of radiocesium in tree rings formed prior to 1986 and grown at the ash-treated plot was about two to three times that found in wood from the untreated control plot. (author)

Determination of macro, essential trace elements, toxic heavy metal concentrations, crude oil extracts and ash composition from Saudi Arabian fruits and vegetables having medicinal values

Directory of Open Access Journals (Sweden)

Hana R. Alzahrani

2017-11-01

Full Text Available The concentrations of essential elements (Mg, Ca, Na, K, Fe, Zn, Se, Al, Ni, and Cu and toxic heavy metals (Pb, As, Cr, Cd, and Cr from Saudi Arabian fruits and vegetables were determined by inductively coupled plasma optical emission spectrophotometry (ICP/OES. Two types of butters, Caralluma munbayana and Caralluma hesperidum, Vigna (Vigna unguiculata, common fig (Ficus carica, Annona seeds (Annonaceae seeds, Annona fruits (Annonaceae fruits, Fennel (Foeniculum vulgare, and Fennel flowers (Nigella sativa were investigated, because they are used by indigenous groups as traditional medicines with Soxhlet-extraction and dry-ashing protocol. The estimated daily dietary element intake in food samples was further calculated in order to evaluate the element dietary intake and fruit and vegetable consumption pattern of the indigenes of Saudi Arabia. The crude oil and ash compositions varied widely, but suggested that most of the foods were good sources of oils and minerals. The figures-of-merit of the ICP-OES calibration curves were excellent with good linearity (R2 > 0.9921. The use of ICP-OES in this study allowed the accurate analysis and the detection of the elements at low levels. Essential elements (K, Ca, Na, and Mg had the highest concentrations while toxic heavy metals (As, Pb, and Cd had the lowest in the foods. Essential element pairs (Mg-Na, Mg-Ca, Fe-Al were highly correlated, suggesting that these foods are sources of multiple nutrients. Toxic element pairs (Pb-Cd, Pb-As, and Cd-As, however, were poorly correlated in the foods, suggesting that these elements do not have a common source in these foods. Average consumption of these foods should provide the recommended daily allowances of essential elements, but will not expose consumers to toxic heavy metals. The ICP-OES method was validated by determining method detection limits and percent recoveries of laboratory-fortified blanks, which were generally 90–100%.

Assessment of fly ash-aided phytostabilisation of highly contaminated soils after an 8-year field trial

Energy Technology Data Exchange (ETDEWEB)

Lopareva-Pohu, Alena [Universite Lille Nord de France, Lille (France); Groupe ISA, Equipe Sols et Environnement, Laboratoire Genie Civil et geoEnvironnement Lille Nord de France EA 4515, 48 boulevard Vauban, 59046 Lille Cedex (France); Universite du Littoral-Cote d' Opale, Unite de Chimie Environnementale et Interactions sur le Vivant (UCEIV), EA4492, Maison de la Recherche en Environnement Industriel de Dunkerque 2, Avenue Maurice Schumann, 59140 Dunkerque (France); Pourrut, Bertrand; Waterlot, Christophe [Universite Lille Nord de France, Lille (France); Groupe ISA, Equipe Sols et Environnement, Laboratoire Genie Civil et geoEnvironnement Lille Nord de France EA 4515, 48 boulevard Vauban, 59046 Lille Cedex (France); Garcon, Guillaume [Universite Lille Nord de France, Lille (France); Universite du Littoral-Cote d' Opale, Unite de Chimie Environnementale et Interactions sur le Vivant (UCEIV), EA4492, Maison de la Recherche en Environnement Industriel de Dunkerque 2, Avenue Maurice Schumann, 59140 Dunkerque (France); Bidar, Geraldine; Pruvot, Christelle [Universite Lille Nord de France, Lille (France); Groupe ISA, Equipe Sols et Environnement, Laboratoire Genie Civil et geoEnvironnement Lille Nord de France EA 4515, 48 boulevard Vauban, 59046 Lille Cedex (France); Shirali, Pirouz [Universite Lille Nord de France, Lille (France); Universite du Littoral-Cote d' Opale, Unite de Chimie Environnementale et Interactions sur le Vivant (UCEIV), EA4492, Maison de la Recherche en Environnement Industriel de Dunkerque 2, Avenue Maurice Schumann, 59140 Dunkerque (France); Douay, Francis, E-mail: f.douay@isa-lille.fr [Universite Lille Nord de France, Lille (France); Groupe ISA, Equipe Sols et Environnement, Laboratoire Genie Civil et geoEnvironnement Lille Nord de France EA 4515, 48 boulevard Vauban, 59046 Lille Cedex (France)

2011-01-01

Sustainable management of large surface areas contaminated with trace elements is a real challenge, since currently applied remediation techniques are too expensive for these areas. Aided phytostabilisation appears to be a cost efficient technique to reduce metal mobility in contaminated soils and contaminated particle spread. In this context, this study aimed at evaluating the long-term efficiency of aided phytostabilisation on former agricultural soils highly contaminated with trace elements. The influence of afforestation and fly ash amendments to reduce metal mobility was investigated. Before being planted with a tree mix, the study site was divided into three plots: a reference plot with no amendment, the second amended with silico-aluminous fly ash and the third with sulfo-calcic fly ash. After eight years, some soil physico-chemical parameters, including cadmium (Cd), lead (Pb) and zinc (Zn) extractability were modified. In particular, pH decreased on the whole site while organic carbon content increased. The alteration of these parameters influencing trace element mobility is explained by afforestation. Over time, concentrations of CaCl{sub 2}-extractable metals increased and were correlated with the soil pH decrease. In the amended soils, extractable Cd, Pb and Zn concentrations were lower than in the reference soil. The results indicated that the two fly ashes buffered natural soil acidification due to vegetation development and limited trace element mobility and thus could limit their bioavailability. For long-term phytostabilisation, special attention should be focused on the soil pH, metal mobility and phytoavailability analysis. - Research Highlights: {yields} Afforestation leads to soil pH decrease and organic carbon content increase. {yields} Fly ashes buffered natural soil acidification. {yields} Fly ashes limited metal mobility.

Assessment of fly ash-aided phytostabilisation of highly contaminated soils after an 8-year field trial

International Nuclear Information System (INIS)

Lopareva-Pohu, Alena; Pourrut, Bertrand; Waterlot, Christophe; Garcon, Guillaume; Bidar, Geraldine; Pruvot, Christelle; Shirali, Pirouz; Douay, Francis

2011-01-01

Sustainable management of large surface areas contaminated with trace elements is a real challenge, since currently applied remediation techniques are too expensive for these areas. Aided phytostabilisation appears to be a cost efficient technique to reduce metal mobility in contaminated soils and contaminated particle spread. In this context, this study aimed at evaluating the long-term efficiency of aided phytostabilisation on former agricultural soils highly contaminated with trace elements. The influence of afforestation and fly ash amendments to reduce metal mobility was investigated. Before being planted with a tree mix, the study site was divided into three plots: a reference plot with no amendment, the second amended with silico-aluminous fly ash and the third with sulfo-calcic fly ash. After eight years, some soil physico-chemical parameters, including cadmium (Cd), lead (Pb) and zinc (Zn) extractability were modified. In particular, pH decreased on the whole site while organic carbon content increased. The alteration of these parameters influencing trace element mobility is explained by afforestation. Over time, concentrations of CaCl 2 -extractable metals increased and were correlated with the soil pH decrease. In the amended soils, extractable Cd, Pb and Zn concentrations were lower than in the reference soil. The results indicated that the two fly ashes buffered natural soil acidification due to vegetation development and limited trace element mobility and thus could limit their bioavailability. For long-term phytostabilisation, special attention should be focused on the soil pH, metal mobility and phytoavailability analysis. - Research Highlights: → Afforestation leads to soil pH decrease and organic carbon content increase. → Fly ashes buffered natural soil acidification. → Fly ashes limited metal mobility.

Transformations and affinities for sulfur of Chinese Shenmu coal ash in a pulverized coal-fired boiler

Energy Technology Data Exchange (ETDEWEB)

Cheng, J.; Zhou, J.H.; Liu, J.Z.; Cao, X.Y.; Cen, K.F. [Zhejiang University, Hangzhou (China)

2009-07-01

The self-desulfurization efficiency of Shenmu coal with a high initial Ca/S molar ratio of 2.02 was measured in a 1,025 t/h pulverized coal-fired boiler. It increases from 29% to 32% when the power capacity decreases from 100% to 70%. About 60% of the mineral matter and calcium element fed into the furnace is retained in the fly ash, while less than 10% is retained in the bottom ash. About 70% of the sulfur element fed into the furnace is emitted as SO{sub 2} in the flue gas, while less than 10% is retained in the fly ash and less than 1% is retained in the bottom ash. The mineralogical compositions of feed coal, fly ash, and bottom ash were obtained by X-ray diffraction analysis. It is found that the initial amorphous phase content is 91.17% and the initial CaCO{sub 3} phase content is 2.07% in Shenmu coal. The vitreous phase and sulfation product CaSO{sub 4} contents are, respectively, 70.47% and 3.36% in the fly ash obtained at full capacity, while the retained CaCO{sub 3} and CaO contents are, respectively, 4.73% and 2.15%. However, the vitreous phase content is only 25.68% and no CaSO{sub 4} is detected in the bottom ash obtained at full capacity. When the power capacity decreases from 100% to 70%, the vitreous phase content in fly ash decreases from 70.47% to 67.41% and that in bottom ash increases from 25.68% to 28.10%.

Reducing Heavy Metal Element from Coal Bottom Ash by Using Citric Acid Leaching Treatment

Directory of Open Access Journals (Sweden)

Yahya Ahmad Asyari

2017-01-01

Full Text Available Coal ash is the residue that is produced during coal combustion for instance fly ash, bottom ash or boiler slag which was primarily produced from the combustion of coal. With growth in coal burning power station, huge amount of coal bottom ash (CBA considered as hazardous material which are normally disposed in an on-site disposal system without any commercialization purpose. Previous researchers have studied the extraction of silica from agricultural wastes such as palm ash and rice husk ash (RHA and CBA by using leaching treatment method. In this study, the weaker acid, citric acid solution was used to replace the strong acid in leaching treatment process. Result showed that the heavy metal content such as Copper (Cu, Zinc (Zn and Lead (Pb can be decrease. Meanwhile the silica can be extracted up to 44% from coal bottom ash using citric acid leaching treatment under the optimum reaction time of 60 minutes with solution temperature of 60°C and concentration of citric acid more than 2%.

Kinetics of fly ash beneficiation by carbon burnout. Quarterly report, July 1--September 30, 1997

Energy Technology Data Exchange (ETDEWEB)

Dodoo, J.N.D.; Okoh, J.M.; Diaz, A.

1998-08-01

Oxidation studies of coal fly ash have been carried out at partial pressures in the range 1 atmosphere down to 400 torr. The studies have also been carried out at 1 atmosphere for different temperatures in the range 500 to 750 C. The equipment used was a state-of-the-art Cann Thermogravimetric analyzer having sensitive microbalance that permitted measurements to .1 {micro}g. The analyzer is part of a GC/MS/TG setup in this laboratory. The fly ash was supplied by Delmarva Power Indian River Plant, DE. The samples were dried and stored in a desiccator to ensure that they remained dry prior to combustion. The combustion process inside the TGA is continuous and the heat released can be related to the percent of carbon consumed. The setup provided easy identification of the elements in the fly ash. The elemental analysis was also augmented by use of an energy dispersive X-ray analyzer. In the X-ray analysis the carbon in the fly ash was compared with that in a dolomite (CaMg(CO{sub 3}){sub 2}) standard obtained from the US Bureau of Mines (USBOM). Preliminary data show encouraging results in the rate of reduction of the residual carbon. Both analyses show reduction of carbon after burning.

Radiochemical analysis of the Bikini ashes

Energy Technology Data Exchange (ETDEWEB)

Ishibashi, M; Shigematsu, T; Ishida, T

1954-01-01

The following nuclides were detected in the Bikini ashes by radiochemical procedures: /sup 45/Ca, /sup 89/Sr, /sup 91/Y, /sup 95/Zr, /sup 103/Ru, /sup 144/Pr, and /sup 237/U. The ion-exchange method was used for analysis of contaminated rain water which fell on the Kyoto area on May 16, 1954 from which the presence of /sup 89/Sr, /sup 95/Zr, and /sup 140/Ba, was detected. Rare earths seemed also to be present.

Coal combustion by-product quality at two stoker boilers: Coal source vs. fly ash collection system design

Energy Technology Data Exchange (ETDEWEB)

Mardon, Sarah M. [Kentucky Department for Environmental Protection, Division of Water, Frankfort, KY 40601 (United States); Hower, James C. [University of Kentucky Center for Applied Energy Research, 2540 Research Park Drive, Lexington, KY 40511 (United States); O' Keefe, Jennifer M.K. [Morehead State University, Department of Physical Sciences, Morehead, KY 40351 (United States); Marks, Maria N. [Environmental Consulting Services, Lexington, KY 40508 (United States); Hedges, Daniel H. [University of Kentucky, Department of Earth and Environmental Sciences, Lexington, KY 40506 (United States)

2008-09-15

Fly ashes from two stoker boilers burning Pennsylvanian Eastern Kentucky high volatile A bituminous coal blends were examined for their petrology and chemistry. The source coals have similar trace element contents. One of the ash collection systems was retrofitted with a baghouse (fabric filter) system, collecting a finer fly ash at a cooler flue gas temperature than the plant that has not been reconfigured. The baghouse ash has a markedly higher trace element content than the coarser fly ash from the other plant. The enhanced trace element content is most notable in the As concentration, reaching nearly 9000 ppm (ash basis) for one of the collection units. Differences in the ash chemistry are not due to any substantial differences in the coal source, even though the coal sources were from different counties and from different coal beds, but rather to the improved pollution control system in the steam plant with the higher trace element contents. (author)

Geochemistry of Sediment from IODP Expeditions 322 and 333: Terrigenous Provenance, Dispersed Ash, and the Nankai 'Subduction Factory'

Science.gov (United States)

Scudder, R.; Murray, R. W.; Schindlbeck, J.; Kutterolf, S.

2013-12-01

Terrigenous material and volcanic ash play important roles in the IODP Seismogenic Zone and 'Subduction Factory' initiatives. Particularly relevant to these projects are studies of geochemical budgets including how fluids within subducting sediment will be affected by hydration/dehydration reactions. Of great importance is the volcanic component, which occurs both as discrete ash layers and as ash dispersed throughout the sediment column and their related altered products in the down-going plate. Based on bulk sedimentary geochemical studies of IODP Sites C0011 and C0012 drilled during Expeditions 322 and 333, we will show the importance of dispersed ash to the Nankai subduction zone and document important changes in terrigenous provenance to these locations. The major elemental characteristics of the hemipelagic mudstones are remarkably consistent both downcore and between Site C0011 and Site C0012. For example, the average Si/Al ratio at both sites C0011 and C0012 is 3.3 × 0.2. This is observed in other key major elemental indicators as well (e.g., Fe2O3). Alkali elements, Trace elements and REEs exhibit greater downcore variability while remaining consistent between the sites. Ternary diagrams such as La-Th-Sc and Sc-Cr-Th as well as other geochemical plots (i.e., Sm/Al vs. Th/Al) show that Site C0011 and Site C0012 are fairly clustered, derived primarily from a continental arc source, and that distal sources to the sediment are important in addition to a modest and varying component from the proximal Izu-Bonin Island Arc. Multivariate statistical treatments are further being applied to the datasets from these sites to allow a better determination of the number of sources that make up the bulk sediment (and their provenance). Q-mode Factor Analysis was performed in order to determine the composition of potential end member contributions to these sites. The multivariate statistics indicate Site C0011 and C0012 each have 4-5 end members that explain 98% of the

False deformation temperatures for ash fusibility associated with the conditions for ash preparation

Energy Technology Data Exchange (ETDEWEB)

Wall, T.F.; Gupta, S.K.; Gupta, R.P.; Sanders, R.H.; Creelman, R.A.; Bryant, G.W. [University of Newcastle, Callaghan, NSW (Australia). Cooperative Research Centre for Black Coal Utilization, Dept. of Chemical Engineering

1999-07-01

A study was made to investigate the fusibility behaviour of coal ashes of high ash fusion temperatures. Coals and ashes formed in the boiler were sampled in several Australian power stations, with laboratory ashes being prepared from the coals. The laboratory ashes gave lower values for the deformation temperature (DT) than the combustion ashes when the ash had low levels of basic oxide components. Thermo-mechanical analysis, quantitative X-ray diffraction and scanning electron microscopy were used to establish the mechanisms responsible for the difference. Laboratory ash is finer than combustion ash and it includes unreacted minerals (such as quartz, kaolinite and illite) and anhydrite (CaSO{sub 4}). Fusion events which appear to be characteristic of reacting illite, at temperatures from 900 to 1200{degree}C, were observed for the laboratory ashes, these being associated with the formation of melt phase and substantial shrinkage. The combustion ashes did not contain this mineral and their fusion events were observed at temperatures exceeding 1300{degree}C. The low DTs of coal ashes with low levels of basic oxides are therefore a characteristic of laboratory ash rather than that found in practical combustion systems. These low temperatures are not expected to be associated with slagging in pulverised coal fired systems. 10 refs., 3 figs., 2 tabs.

Natural revegetation of coal fly ash in a highly saline disposal lagoon in Hong Kong

Energy Technology Data Exchange (ETDEWEB)

Chu, L.M. [Chinese University of Hong Kong, Hong Kong (China). Dept. of Biology

2008-08-15

Question: What is the relationship of the naturally colonizing vegetation and substrate characteristics in fly ash lagoons? Location: West lagoon, Deep Bay, a 13-ha coastal lagoon in Hong Kong in subtropical Southeast Asia. Methods: Vegetation establishment was examined in a coal fly ash lagoon two years after its abandonment to investigate the distribution of vegetation in relationship to the chemical properties of the fly ash in the lagoon. A greenhouse experiment assessed the limits imposed on plant growth in fly ash. Results: The fly ash was saline, slightly alkaline and very poor in organic matter and nitrogen. Ash from bare and vegetated areas differed significantly in their salinity and extractable concentrations of inorganic nitrogen and various metals. Bare ash had a significantly higher conductivity and extractable sodium, aluminum, manganese, potassium. and lead. In total 11 plant species that belonged to seven families were found growing on the fly ash: all species except the shrub Tamarix chinensis were herbaceous. Using discriminant analysis, the most important factors in distinguishing bare and vegetated ashes were conductivity and sodium. Cluster analysis of bare samples gave two distinct groups, one from the periphery of the lagoon, which had lower sodium, conductivity, organic carbon, potassium and copper, and the other from a second group that contained ashes from the central region of the lagoon. Results of the greenhouse experiment showed that the inhibition of plant growth was significantly correlated with the presence of soluble toxic elements in ash. Conclusion: Toxicity and salinity seem to be the major limiting factors to plant establishment in fly ash, and these factors must be ameliorated for the successful reclamation of these fly ash lagoons.

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

Science.gov (United States)

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

2013-02-01

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 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 550°C was due to moisture evaporation and dehydration of Ca(OH)(2) and hydrocalumite. Results for the HW-I BA showed that LOI at 550°C was predominantly related to the elemental carbon (EC) content of the sample. Decomposition of CaCO(3) around 700°C was identified in both materials. In addition, we have identified reaction mechanisms that underestimate the EC and overestimate the CaCO(3) 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 650°C) 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. Copyright © 2012 Elsevier Ltd. All rights reserved.

Analysis of polynuclear aromatic hydrocarbons from coal fly ash

International Nuclear Information System (INIS)

Purushothama, S.; Pan, W.-P.; Riley, J.T.; Lloyd, W.G.

1998-01-01

The objective of this work is to compare various extraction and quantification techniques for the determination of adsorbed polynuclear aromatic hydrocarbons (PAHs) on coal ash. Aliquots of a 'clean' fly ash from coal combustion doped with four PAHs have been extracted, using three solvents, three methods and three GC/MS programs. Factorial analysis shows solvent to extert the greatest primary effect: CH 2 Cl 2 > toluene much-gt o-xylene. Highest recoveries were obtained using the reflux slurry extraction procedure with CH 2 Cl 2 and a relatively fast (20 degree C/min) temperature ramp to 310 degree C. With both CH 2 Cl 2 and toluene solvents, ultrasonic assisted extraction affords the best repeatability

Ash Properties of Alternative Biomass

DEFF Research Database (Denmark)

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

2009-01-01

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 ash transformation, ash deposit flux, and deposit chlorine content when biomass fuels are applied for suspension combustion....

An Australian experience with a constructed wetland to treat ash dam water

Energy Technology Data Exchange (ETDEWEB)

M.W. Jensen; K.W. Riley [Delta Electricity (Australia)

2003-07-01

In this paper, the effectiveness of a wetland system to treat water from a power station ash dam is discussed. The wetlands were constructed during 1996 and 1997. The length of the canals within the system is 1700 metres. There was a total planting of 35,000 tube stock of nine different species. In the summer of 1998, Typha orientalis colonised the system and is now the dominant species of emergent plant present. Water is introduced to the wetland from the return channel of the power station. The ash dam water is acidic (pH 4.5 5.5) and contains elevated levels of some trace elements including selenium, boron and fluorine. Of these three trace elements, selenium is regarded as the element of particular environmental concern. Since June 2000, there has been periodic sampling and analysis of both the inlet and outlet waters. The analytes include conductivity, pH, total organic carbon, Al, As, B, Ba, Ca, Cl, K, F, Fe, Mg, Mn, Na, selenite, total selenium, Si, Sr, sulfate and Zn. As well, plant material (stems and roots of the Typha) and sediments have been analysed for selenium. The results indicate boron and fluorine are not removed from the ash dam water by the processes occurring in the wetland. Selenium is partly removed. It appears that selenite is removed in preference to selenate. The development and operation of this experimental wetland is discussed in the context of a sustainable and ecologically sound system of minimising detrimental effects of the discharge of ash water. 26 refs., 4 tabs.

Volcanic ash in feed coal and its influence on coal combustion products

Energy Technology Data Exchange (ETDEWEB)

Brownfield, M.E.; Affolter, R.H.; Cathcart, J.D.; Brownfield, I.K.; Hower, J.C.; Stricker, G.D.; O' Connor, J.T.

2000-07-01

The US Geological Survey and the University of Kentucky Center for Applied Energy Research are collaborating with an Indiana Utility to determine the physical and chemical properties of feed coal and coal combustion products (CCPs) from a coal-fired power plant. The plant utilizes a low-sulfur (.23--.47 weight percent S) coal from the Powder River Basin, Wyoming. Scanning Electron Microscope (SEM) and X-ray diffraction (XRD) analysis of feed coal samples identified two mineral suites. A primary suite (not authigenic) consisting of quartz (detrital and volcanic beta-form grains), biotite, and minor zircon and a secondary authigenic mineral suite containing calcite, alumino-phosphates (crandallite and gorceixite), kaolinite, quartz, anatase, barite, and pyrite. The authigenic minerals are attributed to air-fall and reworked volcanic ash that was deposited in peat-forming mires. The Powder River Basin feed coals contain higher amounts of Ba, Ca, Mg, Na, Sr, and P compared to other analyzed eastern coals. These elements are associated with alumino-phosphate, biotite, calcite, and clay minerals. The element associations are indicative of coal that incorporated volcanic ash during deposition. XRD analysis of CCPs revealed a predominance of glass, perovskite, lime, gehlenite, quartz, and phosphates with minor amounts of periclase, anhydrite, hematite, and spinel group minerals in the fly ash; and quartz, plagioclase (albite and anorthite), pyroxene (augite and fassaite), rhodonite, and akermanite in the bottom ash. Microprobe and SEM analysis of fly ash samples revealed quartz, zircon, monazite, euhedral laths of corundum with merrillite, hematite, dendritic spinels/ferrites, and rounded grains of wollastonite with periclase. The abundant Ca and Mg mineral phases in the fly ashes are related to the presence of carbonate, clay, and phosphate minerals in the feed coal. The Ca- and Mg-rich mineral phases in the CCPs can be attributed to volcanic minerals deposited in the

Elemental analysis in bed sediment samples of Karnafuli estuarine zone in the Bay of Bengal by instrumental neutron activation analysis

International Nuclear Information System (INIS)

Molla, N.I.; Hossain, S.M.; Basunia, S.; Miah, R.U.; Rahman, M.; Sikder, D.H.; Chowdhury, M.I.

1997-01-01

The concentration of rare earths and other elements have been determined in the bed sediment samples of Karnafuli estuarine zone in the Bay of Bengal by instrumental neutron activation analysis (INAA). The samples and the standards soil-5, soil-7, coal fly ash and pond sediment were prepared and simultaneously irradiated for short and long time at the TRIGA Mark-II research reactor facility of Atomic Energy Research Establishment, Savar, Dhaka. The maximum thermal neutron flux was of the order of 10 13 n x cm -2 x s -1 . After irradiation the radioactivity of the product nuclides was measured by using a high resolution high purity germanium detector system. Analysis of γ-ray spectra and quantitative analysis of the elemental concentration were done via the software GANAAS. It has been possible to determine the concentration level of 27 elements including the rare earths La, Ce, Sm, Eu, Tb, Dy and Yb and uranium and thorium. (author)

Melting and Sintering of Ashes

DEFF Research Database (Denmark)

Hansen, Lone Aslaug

1997-01-01

-1300°C, and a trend of higher fusion temperatures with increasing contents of Al-silicates and quartz was found.c) Fly ashes, bottom ashes and deposits from coal/straw co-firing were all found to consist mainly of metal-alumina and alumina-silicates. These ashes all melt in the temperature range 1000......The thesis contains an experimental study of the fusion and sintering of ashes collected during straw and coal/straw co-firing.A laboratory technique for quantitative determination of ash fusion has been developed based on Simultaneous Thermal Analysis (STA). By means of this method the fraction......, the biggest deviations being found for salt rich (i.e. straw derived) ashes.A simple model assuming proportionality between fly ash fusion and deposit formation was found to be capable of ranking deposition rates for the different straw derived fly ashes, whereas for the fly ashes from coal/straw co-firing...

Fire severity effects on ash extractable Total Phosphorous

Science.gov (United States)

Pereira, Paulo; Úbeda, Xavier; Martin, Deborah

2010-05-01

Phosphorous (P) is a crucial element to plant nutrition and limits vegetal production. The amounts of P in soil are lower and great part of this nutrient is absorbed or precipitated. It is well known that fire has important implications on P cycle, that can be lost throughout volatilization, evacuated with the smoke, but also more available to transport after organic matter mineralization imposed by the fire. The release of P depends on ash pH and their chemical and physical characteristics. Fire temperatures impose different severities, according to the specie affected and contact time. Fire severity is often evaluated by ash colour and this is a low-cost and excellent methodology to assess the fire effects on ecosystems. The aim of this work is study the ash properties physical and chemical properties on ash extractable Total Phosphorous (TP), collected in three wildfires, occured in Portugal, (named, (1) Quinta do Conde, (2) Quinta da Areia and (3) Casal do Sapo) composed mainly by Quercus suber and Pinus pinaster trees. The ash colour was assessed using the Munsell color chart. From all three plots we analyzed a total of 102 ash samples and we identified 5 different ash colours, ordered in an increasing order of severity, Very Dark Brown, Black, Dark Grey, Very Dark Grey and Light Grey. In order to observe significant differences between extractable TP and ash colours, we applied an ANOVA One Way test, and considered the differences significant at a p<0.05. The results showed that significant differences in the extractable TP among the different ash colours. Hence, to identify specific differences between each ash colour, we applied a post-hoc Fisher LSD test, significant at a p<0.05. The results obtained showed significant differences between the extractable TP from Very dark Brown and Black ash, produced at lower severities, in relation to Dark Grey, Very Dark Grey and Light Grey ash, generated at higher severities. The means of the first group were higher

Physico-chemical characterisation of Indian biomass ashes

Energy Technology Data Exchange (ETDEWEB)

K. Umamaheswaran; Vidya S. Batra [Energy and Resources Institute (TERI), New Delhi (India)

2008-05-15

India stands fourth in biomass utilisation for various purposes like domestic, commercial and industrial applications. While extensive studies have been made for coal ash characterisation and utilisation, studies on characterisation of biomass ash and its utilisation has not been addressed. In this paper, biomass ash from five sources i.e. rice husk, bagasse, groundnut shell, cashewnut shell, and arecanut shell have been characterised. Chemical composition analysis, particle size analysis, thermal analysis, and microstructure analysis were carried out. Results show that in all ashes silica is the major compound with particle size ranging from 15 to 30 {mu}m and having irregular shape. Ash powders originating from cashewnut shell, arecanut shell and groundnut shell also have compounds of calcium, magnesium and potassium. Bagasse and cashewnut shell ashes have high LOI due to presence of unburnt carbon, P{sub 2}O{sub 5} and other volatiles. 16 refs., 22 figs., 3 tabs.

AL(0) in municipal waste incinerator ash

Science.gov (United States)

Stipp, S. L.; Ronsbo, J. G.; Zunic, T. B.; Christensen, T. H.

2003-04-01

Disposal of municipal waste is a challenge to society. Waste volume is substantially decreased by incineration but residual ash usually contains a number of toxic components which must be immobilised to insure environmental protection. One element, chromium, is mobile and toxic in its oxidised state as Cr(VI) but it can be reduced to Cr(III) and immobilised. Reduction can be promoted by ash treatment with Fe(0) or Fe(II), but recent evidence shows that at least some Cr(VI) is reduced spontaneously in the ash. Aspects of ash behaviour suggest metallic aluminium as the reducing agent, but no direct evidence of Al(0) has been found until now. We examined filter ash from an energy-producing, municipal-waste incinerator (Vest-forbrænding) near Copenhagen. X-ray diffraction (XRD) identified expected salts of Na, K and Ca such as halite, sylvite, calcite, anhydrite and gypsum as well as quartz, feldspar and some hematite. Wave-dispersive electron microprobe produced elemen-tal maps of the ash; Al-rich areas were analysed quantitatively by comparison with standards. We identified metallic Al particles, averaging 50 to 100 micrometers in di-ameter, often with a fractured, glassy border of aluminum oxide. The particles were porous, explaining fast Cr(VI) reduction and they contained thin exsolution lamellae of Al-alloys of Pb and Cu or Mn, Fe and Ag, which provide clues of the Al(0) origin in the waste. Sometimes Al(0) occurred inside glassy globes of Al2O3. Time-of-flight secondary ion mass spectroscopy (TOF-SIMS) and X-ray photoelectron spectroscopy (XPS) proved that surface Al concentrations on ash particles were below detection, confirming reactivity of the Al(0) bulk. The persistence of reduced Al through the highly oxidising combustion procedure comes as a surprise and is a benefit in the immobilisation of Cr(VI) from municipal-waste incineration residues.

Biological and chemical interactions excelerating the removal of impurities from fly ashes

Directory of Open Access Journals (Sweden)

Štyriaková Iveta

2002-03-01

Full Text Available The mesophilic bacteria were isolated from the deposit of fly ash in Chalmová (Slovakia and identified using the BBL identification system. Bacillus cereus was the dominant species in this deposit of aluminosilicate minerals. Under laboratory conditions , Bacillus cereus accelerated the extraction of major and trace impurities in fly ash during bioleaching processes. This process was dependent on bacterial adhesion and production of organic acids. The effect of organic acids produced by bacteria was detected especially in sites where impregnated metals were found in the aluminosilicate structure. Amorphous spherical aluminosilicate particles in allotriomorphic aluminosilicate grains represent a main mineral component of fly-ash in which also elements such as Fe, Ti, Mn, As are bound. The rate of mobilization of Al, Si and Ti from coal fly ash under biochemically relevant conditions in vitro was previously shown to depend on the quantity of the ash microspheres. The qualitative EDS analyse of leachates confirmed the extraction of toxic elements (As and Mn from the initial sample of fly ash.Heterotrophic bacteria of Bacillus genus are capable to remove impurities from deposited fly-ash. A long-term deposition of energy fly-ash causes chemical and mineralogical changes as a result of weathering processes. Depending on the composition of coal concentrate containing SiO2, Al2O3, Fe2O3, CaO, MgO and other oxides, fly ash can provide a useful preliminary batch for the preparation of glass-ceramics or zeolite after extracting of bacterially dissolved elements from it. The mobility of major impurities (Ca and Fe and heavy metals, caused by biochemical leaching of fly ash, suggests the possibility of the development of an alternative way of this raw material treatment. The advantage of bioleaching is relatively low cost and the subsequent low demand for energy compared with conventional technologies.

Impact assessment of fly ash on ground water quality: An experimental study using batch leaching tests.

Science.gov (United States)

Dandautiya, Rahul; Singh, Ajit Pratap; Kundu, Sanghamitra

2018-05-01

The fly ash, generated at the coal-based thermal power plant, is always a cause of concern to environmentalists owing to its adverse impact on air, water and land. There exists a high environmental risk when it is disposed to the environment. Thus, two different type of fly ash samples (FA-1 and FA-2) have been considered in this study to examine the leaching potential of the elements magnesium, aluminium, silicon, calcium, titanium, vanadium, chromium, manganese, iron, nickel, cobalt, copper, zinc, arsenic, selenium, strontium, cadmium, barium and lead for different types of leachant. Toxicity characteristics leaching procedure and ASTM tests have been performed in the laboratory to simulate different natural leaching scenarios. Characterisation of samples have been done through X-ray diffraction and field emission gun scanning electron microscope. The effect of different liquid to solid ratios (i.e. 5, 10, 20 and 50) on the mobilisation of elements has been analysed. The results indicated that the maximum leaching of all elements occurred at a liquid to solid ratio of 5 except for arsenic, barium and silicon. The groundwater analysis has also been done to understand the actual effects of leachate. The elements presenting the highest leachability in the two fly ash samples under all tested conditions were magnesium, aluminium, silicon and calcium. It has been observed that calcium exhibits greater leaching effects than all other constituents. The study presented here has been found very useful for assessing contamination levels in groundwater owing to leaching effects of fly ash under different scenarios, which can be helpful to prevent spreading of the contaminants by efficient management of fly ash.

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.)

Elemental content in cigarette components and its distribution as determined by neutron activation analysis

International Nuclear Information System (INIS)

Metwally, Y.E.

2003-01-01

Cigarette smoking, a world-wide habit. Has a very bad and hazardous effects on the human body. In the present study, different kinds of cigarette brands have been collected from local and foreign markets representing ten countries all over the world. All the selected samples were irradiated in first Inshas reactor (IR-1) in Egypt. A comprehensive study of the elemental contents in cigarette samples under investigation has been carried out by using neutron activation analysis technique. Concentrations of the polluting elements and tracer contents of cigarette tobacco have been determined. The elemental distribution of the component (tobacco. ash. filter before and after smoking and wrapping paper) of some kinds of cigarettes has been studied. The obtained data resulting from the present work were discussed

Possibilities for the Use of Wood Ashes in Agriculture

Directory of Open Access Journals (Sweden)

Barbara Symanowicz

2018-05-01

The following physical properties of the ashes were determined: colour, solubility, porosity, absorbability, compression strength, degree of fineness, moisture content and spreadability. In the ashes obtained from the combustion of wood in a fireplace furnace, the following parameters were determined: pH H2O, pHKCl (1 mole dm-3 KCl, pHCaCl2 (0.01 mole dm-3 CaCl2 and total alkalinity in terms of the suitability of ashes as a liming agent. The contents of Ctot. and Ntot. were determined with a CHNS/O elemental analyser by Perkin-Elmer and the contents of other elements (macronutrients and heavy metals were specified using the method of atomic emission spectrometry with inductively coupled plasma ICP-AES. Wood ashes are a source of macronutrients for plants. Their contents can be presented in the following series of decreasing values: Ca > C > K > Mg > P > S > N. Out of 1 t of wood ash, approx. 160 kg C, 6 kg N, 20 kg P, 98 kg K, 302 kg Ca, 39 kg Mg and 18 kg S can be introduced into the soil. The content of heavy metals in the analysed ashes was low, and exceeded the acceptable standards for their content in waste materials intended for liming soils. The analysed ashes exhibit good physical and chemical properties. They can be suitable for use in agriculture as a liming agent to be applied on medium and heavy soils.

Concentration of trace elements in marine organisms

International Nuclear Information System (INIS)

Ishii, Takaaki; Suzuki, Hamaji; Iimura, Mitsue; Koyanagi, Taku

1976-01-01

Information on the quality and quantity of stable trace elements in marine environments is frequently required to analyze the radioecological behavior of radionuclides released from nuclear facilities into the sea. In the present work, special attention was concentrated in determination of stable Mn, Fe, Co, Zn, Rb and Cs in marine organisms to estimate the concentration factors for these elements and corresponding radionuclides. Marine organisms (fishes, marine invertebrates and seaweeds) were collected at the seashore of Ibaragi prefecture and provided for chemical analysis after dry-ashing and wet-ashing. Atomic absorption spectrophotometry and neutron activation analysis were applied to determine the concentration of elements. The concentration of stable elements in fish muscle was independent on species of the fishes though slightly higher trends were observed in ''Usumebaru'', Sebastes nivosus for Cs, ''Ishimochi'', Nibea mitsukurii for Zn and Fe compared with other species. The concentration of Co, Zn and Fe in muscle of marine invertebrates was one order of magnitude higher than fish muscles especially in shellfishes for Co. Seaweeds showed peculiar species specificity for the concentration of stable trace elements and remarkable differences was observed between the species even among the same genus. (auth.)

Trace element removal from coal ash leachate by the 10-year-old construction wetland

Energy Technology Data Exchange (ETDEWEB)

Ye, Z.H.; Whiting, S.N.; Qian, J.H.; Lytle, C.M.; Lin, Z.-Q.; Terry, N. [University of California at Berkeley, Berkeley, CA (USA). Dept. of Plant and Microbial Biology

2001-10-01

The study investigated the ability of a 10-year old constructed wetland to treat metal-contaminated leachate emanating from a coal ash pile at the Widows Creek electric utility, Alabama (USA). The two vegetated cells, which were dominated by cattail (Typha latifolia L.) and soft rush (Juncus effusus L.), were very effective at removing Fe and Cd from the wastewater, but less efficient for Zn, S, B, and Mn. The concentrations were decreased by up to 99% for Fe, 91% for Cd, 63% for Zn, 61% for S, 58% for Mn, and 50% for B. Higher pH levels ({gt} 6) in standing water substantially improved the removing efficiency of the wetland for Mn only. The belowground tissues of both cattail and soft rush had high concentrations of all elements; only for Mn, however, did the concentration in the shoots exceed those in the belowground tissues. The concentrations of trace elements in fallen litter were higher than in the living shoots, but lower than in the belowground tissues. The trace element accumulation in the plants accounts for less than 2.5% of the annual loading of each trace element into the wetland. The sediments were the primary sinks for the elements removed from the wastewater. Except for Mn, the concentrations of trace elements in the upper layer (0-5 cm) of the sediment profile tended to be higher than the lower layers (5-10 and 10-15 cm). The conclusion was that constructed wetlands are still able to efficiently remove metals in the long term (i.e. {gt} 10 years after construction). 34 refs., 7 figs., 2 tabs.

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

Energy Technology Data Exchange (ETDEWEB)

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

1998-11-01

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

Micro-scale grain-size analysis and magnetic properties of coal-fired power plant fly ash and its relevance for environmental magnetic pollution studies

Energy Technology Data Exchange (ETDEWEB)

Blaha, U.; Sapkota, B.; Appel, E.; Stanjek, H.; Rosler, W. [University of Tubingen, Tubingen (Germany). Inst. of Geoscience

2008-11-15

Two fly ash samples from a black coal-fired power plant (Bexbach, Germany) were investigated for their magnetic properties, particle structure, grain-size distribution and chemical composition. Grain-size distribution was determined on bulk samples and on magnetic extracts. Magnetic susceptibility of different grain-size fractions was analyzed with respect to the according amount of fractions, high- and low-temperature dependence of magnetic susceptibility and thermal demagnetization of IRM identified magnetite and hematite as magnetic phases. Magnetic spherules were quantitatively extracted from bulk fly ash samples and examined using SEM/EDX analysis. Particle morphology and grain-size analysis on the magnetically extracted material were studied. Individual spherule types were identified and internal structures of selected polished particles were investigated by SEM and EDX analyses. Main element contents of the internal structures which consist of 'magnetite' crystals and 'glassy' matrix were systematically determined and statistically assessed. The chemical data of the micro-scale structures in the magnetic spherules were compared with XRF data from bulk material, revealing the relative element distribution in composed magnetic spherules. Comparison of the bulk sample grain-size (0.5-300 {mu}m) and grain-size spectra from magnetic extracts (1-186.5 {mu}m) shows that strongly magnetic particles mainly occur in the fine fractions of < 63 {mu}m. This study comprises a comprehensive characterization of coal-fired power plant fly ash, using magnetic, chemical, and microscopic methods. The results can serve as reference data for a variety of environmental magnetic studies.

Leaching characteristics of toxic constituents from coal fly ash mixed soils under the influence of pH

Energy Technology Data Exchange (ETDEWEB)

Komonweeraket, Kanokwan [Department of Civil and Environmental Engineering, University of Wisconsin, Madison, WI 53706 (United States); Cetin, Bora, E-mail: bora.cetin@sdsmt.edu [College of Engineering, University of Georgia, Athens, GA 30602 (United States); Benson, Craig H., E-mail: chbenson@wisc.edu [Department of Civil and Environmental Engineering, University of Wisconsin, Madison, WI 53706 (United States); Aydilek, Ahmet H., E-mail: aydilek@umd.edu [Department of Civil and Environmental Engineering, University of Maryland, College Park, MD 20742 (United States); Edil, Tuncer B., E-mail: edil@engr.wisc.edu [Department of Civil and Environmental Engineering, University of Wisconsin, Madison, WI 53706 (United States)

2015-04-15

Highlights: • The impact of pH on the leaching of elements and metals from fly ash mixed soils. • Generally Ca, Cd, Mg, and Sr follows a cationic leaching pattern. • The leaching of As and Se shows an oxyanionic leaching pattern. • The leaching behavior of elements does not change based on material type. • Different fly ash types show different abilities in immobilizing trace elements. - Abstract: Leaching behaviors of Arsenic (As), Barium (Ba), Calcium (Ca), Cadmium (Cd), Magnesium (Mg), Selenium (Se), and Strontium (Sr) from soil alone, coal fly ash alone, and soil-coal fly ash mixtures, were studied at a pH range of 2–14 via pH-dependent leaching tests. Seven different types of soils and coal fly ashes were tested. Results of this study indicated that Ca, Cd, Mg, and Sr showed cationic leaching pattern while As and Se generally follows an oxyanionic leaching pattern. On the other hand, leaching of Ba presented amphoteric-like leaching pattern but less pH-dependent. In spite of different types and composition of soil and coal fly ash investigated, the study reveals the similarity in leaching behavior as a function of pH for a given element from soil, coal fly ash, and soil-coal fly ash mixtures. The similarity is most likely due to similar controlling mechanisms (e.g., solubility, sorption, and solid-solution formation) and similar controlling factors (e.g., leachate pH and redox conditions). This offers the opportunity to transfer knowledge of coal fly ash that has been extensively characterized and studied to soil stabilized with coal fly ash. It is speculated that unburned carbon in off-specification coal fly ashes may provide sorption sites for Cd resulting in a reduction in concentration of these elements in leachate from soil-coal fly ash mixture. Class C fly ash provides sufficient CaO to initiate the pozzolanic reaction yielding hydrated cement products that oxyanions, including As and Se, can be incorporated into.

Analysis of rare earth elements in coal fly ash using laser ablation inductively coupled plasma mass spectrometry and scanning electron microscopy

Science.gov (United States)

Thompson, Robert L.; Bank, Tracy; Montross, Scott; Roth, Elliot; Howard, Bret; Verba, Circe; Granite, Evan

2018-05-01

Reference standard NIST SRM 1633b and FA 345, a fly ash sample from an eastern U.S. coal power plant, were analyzed to determine and quantify the mineralogical association of rare earth elements (REE). These analyses were completed using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and a scanning electron microscope, equipped with an energy-dispersive X-ray spectrometer (SEM-EDS). Internal standardization was avoided by quantifying elemental concentrations by normalizing to 100% oxides. Mineral grains containing elevated REE concentrations were found in diverse chemical environments, but were most commonly found in regions where Al and Si were predominant. Dividing the spot analyses into time segments yielded plots that showed the REE content changing over time as individual mineral grains were being ablated. SEM-EDS images of FA 345 confirmed the trends that were found in the LA-ICP-MS results. Small grains of apatite, monazite, or zircon were frequently observed as free mineral grains or embedded in amorphous aluminosilicate glass and were not associated with ferrous particles. This finding is consistent with previous reports that magnetic enrichment may be an effective way of concentrating non-magnetic REE phases. Furthermore, aggressive mechanical and chemical-based separation schemes will be required to separate and recover REE from aluminosilicate glass.

Assessment of elements in coal related to environmental concern

International Nuclear Information System (INIS)

Diah Dwiana Lestiani; Muhayatun Santoso; Natalia Adventini

2010-01-01

National energy consumption increases rapidly in line with the economic growth and population. Indonesian government plans to develop electrical power plant 10 000 MW program to anticipate this matter, first step of which is focused on coal power plant. In this study, coal combustion was assessed on its environmental impact. Determination of trace and toxic elements was applied by instrumental neutron activation analysis. Samples were irradiated in Rabbit System at GA Siwabessy, Serpong, in reactor with neutron flux ~10 13 n.cm -2 .s -1 , then counted using HPGe detector. The method was validated by analysis of standard reference material NIST SRM 1633b coal fly ash. The results showed that Al and Cr concentrations were 2.1 0±0.80 and 7.63±1.45 mg/kg, respectively, and other elements such as Al, Co, Cs, Ce, Fe, K, La, Mn, Na, Sc, Sm, Ti, and V were still in the range of those in other world coals. Comparison the elements in coal with the elements in fly ash and bottom ash for relative enrichment index, mass balance calculation and mass flow estimation using assumption was also carried out to estimate the total emission estimation related the environmental concerned elements. The total emission of As, Co and Cr were in the range of 0.84-2.28 kg/day or equivalent to 0.49-1.23 % of total elemental mass content in coal. This also indicated that these elements were captured 98-99 % before released to the environment. (author)

Experimental investigation of clay fly ash bricks for gamma-ray shielding

Energy Technology Data Exchange (ETDEWEB)

Mann Harjinder Singh; Mudahar, Gumel Singh [Dept. of Physics, Punjabi University, Patiala (India); Brar, Gurdarshan Singh [Dept. of Higher Education, Additional Project Director, Chandigarh (India); Mann, Kulwinder Singh [Dept. of Applied Sciences, I.K. Gujral Punjab Technical University, Jalandhar (India)

2016-10-15

This study aims to determine the effect of fly ash with a high replacing ratio of clay on the radiation shielding properties of bricks. Some interaction parameters (mass attenuation coefficients, half value layer, effective atomic number, effective electron density, and absorption efficiency) of clay fly ash bricks were measured with a NaI(Tl) detector at 661.6 keV, 1,173.2 keV, and 1,332.5 keV. For the investigation of their shielding behavior, fly ash bricks were molded using an admixture to clay. A narrow beam transmission geometry condition was used for the measurements. The measured values of these parameters were found in good agreement with the theoretical calculations. The elemental compositions of the clay fly ash bricks were analyzed by using an energy dispersive X-ray fluorescence spectrometer. At selected energies the values of the effective atomic numbers and effective electron densities showed a very modest variation with the composition of the fly ash. This seems to be due to the similarity of their elemental compositions. The obtained results were also compared with concrete, in order to study the effect of fly ash content on the radiation shielding properties of clay fly ash bricks. The clay fly ash bricks showed good shielding properties for moderate energy gamma rays. Therefore, these bricks are feasible and eco-friendly compared with traditional clay bricks used for construction.

Get immersed and black in fire ash world. Field Wildgeographers experience.

Science.gov (United States)

Pereira, Paulo; Cerdà, Artemi; Misiune, Ieva; Jordan, Antonio

2015-04-01

Ash is the footprint left by the fire. This residue is very important to landscape recover and is an important source of soil protection after the fire. Get immersed in fire ash world is the same thing of get dirty and do not be recognizable in a fire affected area. To measure ash in the field we have to be careful where to step, how to do the experimental design, collect samples and find with accuracy the places measured before. A good methodology is needed in design field experiments, collect ash samples and monitoring ash evolution (Cerdà and Doerr, 2008; Bodi et al., 2014; Pereira and Ubeda, 2010; Pereira et al. 2011; 2012, 2013, 2014, 2015). The objective of this work is to share with the Avatar world the methodologies used when wildgeographers get immersed in fire ash world, including: 1) Identify the best study area 2) Experimental design 3) Sample collection 4) Get dirty and have fun in the field 5) Laboratory, Statistical and spatial analysis Acknoledgements The author are thankful for the support of the projects POSTFIRE (Soil quality, erosion control and plant cover recovery under different post-fire management scenarios, CGL2013-47862-C2-1-R) funded by the Spanish Ministry of Economy and Competitiveness; GL2008-02879/BTE, LEDDRA 243857, RECARE (Preventing and Remediating Degradation of Soils in Europe Through Land Care, FP7-ENV-2013-TWO STAGE), funded by the European Commission; and for the COST action ES1306 (Connecteur: Connecting European Connectivity Research), FUEGORED (Spanish Network of Forest Fire Effects on Soils, http://grupo.us.es/fuegored/) and to Comissionat per a Universitats i Recerca del DIUE de la Generalitat de Catalunya. References Bodi, M., Martin, D.A., Santin, C., Balfour, V., Doerr, S.H., Pereira, P., Cerda, A., Mataix-Solera, J. (2014) Wildland fire ash: production, composition and eco-hydro-geomorphic effects. Earth-Science Reviews, 130, 103-127. Cerdà, A. y Doerr, S.H. 2008. The effect of ash and needle cover on surface

The standardisation of trace elements in international biological standard reference materials with neutron activation analysis and atomic absorption spectrophotometry

International Nuclear Information System (INIS)

Pieterse, H.

1981-12-01

An investigation was undertaken into the analytical procedures and the identification of problem areas, for the certification of a new biological standard reference material supplied by the International Atomic Energy Agency, namely, a human hair sample designated as HH-I. The analyses comprised the determination of the elements As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Sb, Se, and Zn in the hair sample by using two analytical techniques, namely, Instrumental Neutron Activation Analysis and Atomic Absorption. Three other certified biological reference materials, namely, Orchard Leaves (ORCH-L), Sea Plant Material (SPM-I) and Copepod (MAA-I) were used as control standards. Determinations were made of the moisture content of the samples, using varying conditions of drying, and the necessary corrections were applied to all analytical results so that the final elemental values related to dry weight of samples. Attention was also given to the possible loss of specific elements during ashing of the samples prior to the actual instrumental analysis. The results obtained for the hair sample by the two techniques were in good agreement for the elements Co, Fe, Mn, and Zn, but did not agree for the elements Cr and Sb. As, Hg and Se could only be determined with Instrumental Neutron Activation Analysis, and Cd, Cu and Ni only with Atomic Absorption. Most of the results obtained for the three control standard reference materials were within the ranges specified for the individual elements in each sample. The analytical procedures used for determining Cd, Cr, Cu, Ni and Sb with Instrumental Neutron Activation Analysis and As, Cr, Sb and Se with Atomic Absorption, need further investigation. The measurement of the moisture content and the ashing of samples also require further investigation with a view to improving accuracy

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

Assessment of mobility and bioavailability of contaminants in MSW incineration ash with aquatic and terrestrial bioassays.

Science.gov (United States)

Ribé, V; Nehrenheim, E; Odlare, M

2014-10-01

Incineration of municipal solid waste (MSW) is a waste treatment method which can be sustainable in terms of waste volume reduction as well as a source of renewable energy. In the process fly and bottom ash is generated as a waste material. The ash residue may vary greatly in composition depending on the type of waste incinerated and it can contain elevated levels of harmful contaminants such as heavy metals. In this study, the ecotoxicity of a weathered, untreated incineration bottom ash was characterized as defined by the H14 criterion of the EU Waste Framework Directive by means of an elemental analysis, leaching tests followed by a chemical analysis and a combination of aquatic and solid-phase bioassays. The experiments were conducted to assess the mobility and bioavailability of ash contaminants. A combination of aquatic and terrestrial bioassays was used to determine potentially adverse acute effects of exposure to the solid ash and aqueous ash leachates. The results from the study showed that the bottom ash from a municipal waste incineration plant in mid-Sweden contained levels of metals such as Cu, Pb and Zn, which exceeded the Swedish EPA limit values for inert wastes. The chemical analysis of the ash leachates showed high concentrations of particularly Cr. The leachate concentration of Cr exceeded the limit value for L/S 10 leaching for inert wastes. Filtration of leachates prior to analysis may have underestimated the leachability of complex-forming metals such as Cu and Pb. The germination test of solid ash and ash leachates using T. repens showed a higher inhibition of seedling emergence of seeds exposed to the solid ash than the seeds exposed to ash leachates. This indicated a relatively low mobility of toxicants from the solid ash into the leachates, although some metals exceeded the L/S 10 leaching limit values for inert wastes. The Microtox® toxicity test showed only a very low toxic response to the ash leachate exposure, while the D. magna

Benefit-cost framework for analysis of trace element emissions from coal-fired power plants. [103 references

Energy Technology Data Exchange (ETDEWEB)

None

1979-11-01

The major conclusions of this report may be summarized in the following four points: (1) It is probable that atmospheric emissions of trace elements from Southwestern coal-fired power plants will not cause major problems over the next 20 years. But monitoring for trace element build-up (especially mercury, selenium, and arsenic) in the mountains of southern Colorado, Navajo Reservoir, and other local hot spots would be an important and desirable step. (2) It appears that damage from trace elements in disposed ash is more likely than damage from atmospheric trace element emissions. But whether damage from disposed ash will actually occur is highly uncertain. We recommend that additional research be conducted on the entire range of issues surrounding ash disposal. (3) In the area of legislation and regulation, there may be some need for review of regulations concerning trace element atmospheric emissions. Present regulation of ash disposal is very likely to need revision and extension. (4) Future research on the environmental problems of coal-fired power plants should place emphasis on atmospheric emissions of sulfur and nitrogen oxides; consequent problems of acid precipitation also need exploration. Environmental research on coal-fired power plants does not need to exclude other problems. But issues surrounding sulfur emissions, nitrogen emissions, sulfate transformations, and acid precipitation appear to merit major emphasis. Perhaps the most important aspect of the preceding list of conclusions is that more questions are raised than are answered. As work on the subject proceeded, it became apparent that an important task was to point future research in the right direction.

Partitioning behaviour of trace elements in a stoker-fired combustion unit : An example using bituminous coals from the Greymouth coalfield (Cretaceous), New Zealand

Energy Technology Data Exchange (ETDEWEB)

Li, Z.; Moore, T.A.; Weaver, S.D. [University of Canterbury, Department of Geological Science, Christchurch (New Zealand); Clemens, A.H.; Gong, D. [CRL Energy Ltd, PO Box 31 244, Lower Hutt (New Zealand); Eby, N. [Department of Environmental, Earth and Atmospheric Sciences, University of Massachusetts, Lowell, MA 01854 (United States)

2005-07-20

In order to understand trace element behaviour during combustion of coals from the Greymouth coalfield, combustion tests were performed on three seam composite samples. The major and trace elements from sub-samples of feed coal, bottom ash, fly ash, and flue gas were analysed by different techniques including inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma-atomic emission spectrometry (ICP-AES), wavelength dispersive X-ray fluorescence (WD-XRF), and scanning electron microscopy with energy-dispersive X-ray analyser (SEM-EDXA). To help better understand trace element partitioning in combustion ash, float-sink and sequential leaching experiments were also employed to determine the association of trace elements with mineral matter or organic matter. Instrumental Neutron Activation Analysis (INAA) was also employed to determine trace element content in float and sink fractions of fly ash as well as in three major phases in the bottom ash. The partitioning behaviour of trace elements, including some that are environmentally sensitive, was also investigated through the use of float-sink tests and direct determination of trace elements in different combustion ash types and phases. Mass balance and partitioning of major and trace elements have been studied to determine the fate of trace elements after combustion. The partitioning of trace elements, especially hazardous air pollutants (HAPs), in different combustion ashes can be summarised as follows:1.Most trace elements, especially As, Ba, Co, Cr, Mn, Ni, are partitioned in the glassy and refractory bottom ash fractions. 2.A significant proportion of trace elements of As, Se, and Pb are partitioned into fly ash fractions. 3.Some volatile elements (e.g. > 90% of S and Hg and up to 64% of Cl) and, to a lesser extent, B (up to 44%) and Cd (up to 50%) are partitioned in the flue gas fraction. 4.Although the low ash yield of Greymouth coal seams have the advantage of generating less solid

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.

Processed bottom ash for replacing fine aggregate in making high-volume fly ash concrete

Directory of Open Access Journals (Sweden)

Antoni

2017-01-01

Full Text Available Bottom ash is a coal plant by-product that is abundant and underutilized. There is the potential use of bottom ash as a fine aggregate replacement in concrete mixtures; however, the problems of water absorption and uniformity of quality of the material need to be overcome first. In this study, bottom ash was treated by sieve separation and pounding to smaller particle size for use as a sand substitute. The physical and chemical characteristics of bottom ash were tested after treatment including water absorption, sieve analysis, and fineness modulus. Highvolume fly ash (HVFA mortar specimens were made and the compressive strength and flowability test using bottom ash after treatment are compared with that of the sand specimen. Low water to cementitious ratio was used to ensure higher strength from the cementitious paste and superplasticizer demand was determined for each treatment. The result showed that bottom ash can be used as fine aggregate replacement material. Sieve separation of the bottom ash could produce 75% of the compressive strength compared with the control sand specimen, whereas pounded bottom ash could have up to 96% of the compressive strength of the control specimen. A 28-day compressive strength of 45 MPa was achievable with 100% replacement of fine aggregate with bottom ash.

Coal fly ash-slag-based geopolymers: microstructure and metal leaching.

Science.gov (United States)

Izquierdo, Maria; Querol, Xavier; Davidovits, Joseph; Antenucci, Diano; Nugteren, Henk; Fernández-Pereira, Constantino

2009-07-15

This study deals with the use of fly ash as a starting material for geopolymeric matrices. The leachable concentrations of geopolymers were compared with those of the starting fly ash to evaluate the retention of potentially harmful elements within the geopolymer matrix. Geopolymer matrices give rise to a leaching scenario characterised by a highly alkaline environment, which inhibits the leaching of heavy metals but may enhance the mobilization of certain oxyanionic species. Thus, fly ash-based geopolymers were found to immobilize a number of trace pollutants such as Be, Bi, Cd, Co, Cr, Cu, Nb, Ni, Pb, Sn, Th, U, Y, Zr and rare earth elements. However, the leachable levels of elements occurring in their oxyanionic form such as As, B, Mo, Se, V and W were increased after geopolymerization. This suggests that an optimal dosage, synthesis and curing conditions are essential in order to obtain a long-term stable final product that ensures an efficient physical encapsulation.

Coal fly ash-slag-based geopolymers: Microstructure and metal leaching

Energy Technology Data Exchange (ETDEWEB)

Izquierdo, Maria, E-mail: mariaizq@ija.csic.es [Institute of Earth Sciences ' Jaume Almera' -CSIC, Lluis Sole Sabaris s/n 08028 Barcelona (Spain); Querol, Xavier [Institute of Earth Sciences ' Jaume Almera' -CSIC, Lluis Sole Sabaris s/n 08028 Barcelona (Spain); Davidovits, Joseph [Cordi-Geopolymere, Espace Creatis, Z.A. Bois de la Chocque 02100 Saint-Quentin (France); Antenucci, Diano [Institut Scientifique de Service Public (ISSeP) 200, rue du Chera, B-4000 Liege (Belgium); Nugteren, Henk [Delft University of Technology, Faculty of Applied Sciences, DelftChemTech, Particle Technology Group, Julianalaan 136, 2628 BL Delft (Netherlands); Fernandez-Pereira, Constantino [University of Seville, School of Industrial Engineering, Department of Chemical and Environmental Engineering, Camino de los Descubrimientos s/n, 41092 Seville (Spain)

2009-07-15

This study deals with the use of fly ash as a starting material for geopolymeric matrices. The leachable concentrations of geopolymers were compared with those of the starting fly ash to evaluate the retention of potentially harmful elements within the geopolymer matrix. Geopolymer matrices give rise to a leaching scenario characterised by a highly alkaline environment, which inhibits the leaching of heavy metals but may enhance the mobilization of certain oxyanionic species. Thus, fly ash-based geopolymers were found to immobilise a number of trace pollutants such as Be, Bi, Cd, Co, Cr, Cu, Nb, Ni, Pb, Sn, Th, U, Y, Zr and rare earth elements. However, the leachable levels of elements occurring in their oxyanionic form such as As, B, Mo, Se, V and W were increased after geopolymerization. This suggests that an optimal dosage, synthesis and curing conditions are essential in order to obtain a long-term stable final product that ensures an efficient physical encapsulation.

Coal fly ash-slag-based geopolymers: Microstructure and metal leaching

International Nuclear Information System (INIS)

Izquierdo, Maria; Querol, Xavier; Davidovits, Joseph; Antenucci, Diano; Nugteren, Henk; Fernandez-Pereira, Constantino

2009-01-01

This study deals with the use of fly ash as a starting material for geopolymeric matrices. The leachable concentrations of geopolymers were compared with those of the starting fly ash to evaluate the retention of potentially harmful elements within the geopolymer matrix. Geopolymer matrices give rise to a leaching scenario characterised by a highly alkaline environment, which inhibits the leaching of heavy metals but may enhance the mobilization of certain oxyanionic species. Thus, fly ash-based geopolymers were found to immobilise a number of trace pollutants such as Be, Bi, Cd, Co, Cr, Cu, Nb, Ni, Pb, Sn, Th, U, Y, Zr and rare earth elements. However, the leachable levels of elements occurring in their oxyanionic form such as As, B, Mo, Se, V and W were increased after geopolymerization. This suggests that an optimal dosage, synthesis and curing conditions are essential in order to obtain a long-term stable final product that ensures an efficient physical encapsulation.

Analysis of Bone Meal (NIST 1486) and Bone Ash (NIST 1400) reference materials by neutron activation method; Analise de materiais de referencia Bone Meal (NIST 1486) e Bone Ash (NIST 1400) pelo metodo de ativacao com neutrons

Energy Technology Data Exchange (ETDEWEB)

Takata, Marcelo K.; Saiki, Mitiko [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil); Borelli, Aurelio [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina

1999-11-01

In this work instrumental neutron activation analysis has been applied to determine Ba, ca, Cl, Cr, fe, Mg, Mn, Na, P, Sb, Sc, Sr and Zn in two biological reference materials NIST 1486 Bone Meal and NIST 1400 Bone Ash. The purpose of this work was to evaluate the precision and the accuracy of the results as well as to give a contribution to certificate these materials. Interferences found in the determination of some elements were also discussed. (author) 8 refs., 4 tabs.

Temperature effects on ash physical and chemical properties. A laboratory study.

Science.gov (United States)

Pereira, Paulo; Úbeda, Xavier; Martin, Deborah

2010-05-01

Fire temperatures have different impacts on ash physical and chemical properties that depend mainly of the specie affected and time of exposition. In a real prescribed or wildland fire, the temperatures produce ash with different characteristics. Know the impacts of a specific temperature or a gradient on a certain element and specie is very difficult in real fires, especially in wildland fires, where temperatures achieve higher values and the burning conditions are not controlled. Hence, laboratory studies revealed to be an excellent methodology to understand the effects of fire temperatures in ash physical and chemical. The aim of this study is study the effects of a temperature gradient (150, 200, 250, 300, 350, 400, 450, 500 and 550°C) on ash physical and chemical properties. For this study we collected litter of Quercus suber, Pinus pinea and Pinus pinaster in a plot located in Portugal. The selected species are the most common in the ecosystem. We submitted samples to the mentioned temperatures throughout a time of two hours and we analysed several parameters, namely, Loss on Ignition (LOI%), ash colour - through the Croma Value (CV) observed in Munsell color chart - CaCO3, Total Nitrogen (TN), Total Carbon (TC), C/N ratio, ash pH, Electrical Conductivity (EC), extractable Calcium (Ca2+), Magnesium (Mg2+), Sodium (Na+), Potassium (K+), Aluminium (Al3+), Manganese (Mn2+), Iron (Fe2+), Zinc (Zn2+), Total Phosphorous (TP), Sulphur (S) and Silica (SiO2). Since we considered many elements, in order to obtain a better explanation of all dataset, we applied a Factorial Analysis (FA), based on the correlation matrix and the Factors were extracted according to the Principle Components method. To obtain a better relation between the variables with a specific Factor we rotated the matrix according to the VARIMAX NORMALIZED method. FA identified 5 Factors that explained a total of 95% of the variance. We retained in each Factor the variables that presented an eigenvalue

On-conveyor belt determination of ash in coal

International Nuclear Information System (INIS)

Sowerby, B.; Lim, C.S.; Abernethy, D.A.; Liu, Y.; Maguire, P.A.

1997-01-01

A laboratory feasibility study has been carried out on new and advanced neutron and gamma-ray analysis systems for the direct on-conveyor belt analysis of ash in coal without the need for sample by-lines. Such an analysis system could deliver the combined advantages of a direct on-conveyor configuration with new and accurate analysis techniques. An industry survey of 18 coal companies carried out in early 1996 indicated that accurate on-belt ash analysis is of the highest priority. Subsequent laboratory work has focussed on the investigation of methods with the potential for improving the accuracy of ash content measurement relative to existing on-belt ash analysers, the most widely-used of which are based on dual energy gamma-ray transmission (DUET), which is sensitive to variations in ash composition. The current work indicates that on-belt neutron/gamma-ray techniques combined with advanced spectral analysis techniques show promise for development into an on-belt ash analysis system which is significantly less sensitive to composition changes than DUET and which analyses a much larger proportion of coal on the belt, thus eliminating some key sources of analysis error

A Comparative study Of Catalityc Activity Of Heterogeneous Base Of Banana Stem Ash And Fly Ash On Production Of Biodiesel Byultrasonic

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Marlinda

2015-08-01

Full Text Available Abstract The use of heterogeneous catalysts in the production of biodiesel provides many advantages due to heterogeneous catalysts can be easily separated from the product so that it can be reused. This research using heterogeneous catalysts derived from natural materials namely banana stem ash and coal fly ash containing alkali and alkaline earth elements. The preparation of catalyst from banana stem ash and coal fly ash used activator KOH 1.9 N and impregnation with KNO3 15 and then heated to a temperature of 550 0C for 3 hours. Results of preparation banana stem ash contains potassium of 36.52 and surface area of 41.901 m2g. This work presents the effect of ultrasonic assisted of waste cooking oil with methanol as solvent using banana stem ash and coal fly ash as catalyst. The diameter of catalyst particles of banana stem ash and coal fly ash varied at 50 100 150 200 and 250 mesh. The transesterification reaction was performed in the presence of ultrasonic operating frequency constant at 40 kHz methanol molar ratio to oil of 9 1 and reaction time of 30 minutes. The methyl ester biodiesel content of product was 93.26 of banana stems ash and 57 of coal fly ash respectively. The physical property was compared with the National Indonesia Standard SNI 2006 with a density viscosity cloud point flash point and cetane number.

Direct Quantitative Analysis of Arsenic in Coal Fly Ash

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Sri Hartuti

2012-01-01

Full Text Available A rapid, simple method based on graphite furnace atomic absorption spectrometry is described for the direct determination of arsenic in coal fly ash. Solid samples were directly introduced into the atomizer without preliminary treatment. The direct analysis method was not always free of spectral matrix interference, but the stabilization of arsenic by adding palladium nitrate (chemical modifier and the optimization of the parameters in the furnace program (temperature, rate of temperature increase, hold time, and argon gas flow gave good results for the total arsenic determination. The optimal furnace program was determined by analyzing different concentrations of a reference material (NIST1633b, which showed the best linearity for calibration. The optimized parameters for the furnace programs for the ashing and atomization steps were as follows: temperatures of 500–1200 and 2150°C, heating rates of 100 and 500°C s−1, hold times of 90 and 7 s, and medium then maximum and medium argon gas flows, respectively. The calibration plots were linear with a correlation coefficient of 0.9699. This method was validated using arsenic-containing raw coal samples in accordance with the requirements of the mass balance calculation; the distribution rate of As in the fly ashes ranged from 101 to 119%.

Nuclear techniques for analysis of coal for calorific value, ash and moisture

International Nuclear Information System (INIS)

Dains, Margaret

1976-03-01

This bibliography includes references on nuclear techniques for analysis of coal for calorific value, ash and moisture content. As the search was directed particularly towards measurement of the ash content of coal using x- and gamma-ray methods, references covering only β-ray techniques have been placed in a separate section. References from Chemical Abstracts prior vol.62 (1965) do not cite the language of the original article. The language of the original has been given for all other articles not in English. (author)

Ash cloud aviation advisories

Energy Technology Data Exchange (ETDEWEB)

Sullivan, T.J.; Ellis, J.S. [Lawrence Livermore National Lab., CA (United States); Schalk, W.W.; Nasstrom, J.S. [EG and G, Inc., Pleasanton, CA (United States)

1992-06-25

During the recent (12--22 June 1991) Mount Pinatubo volcano eruptions, the US Air Force Global Weather Central (AFGWC) requested assistance of the US Department of Energy`s Atmospheric Release Advisory Capability (ARAC) in creating volcanic ash cloud aviation advisories for the region of the Philippine Islands. Through application of its three-dimensional material transport and diffusion models using AFGWC meteorological analysis and forecast wind fields ARAC developed extensive analysis and 12-hourly forecast ash cloud position advisories extending to 48 hours for a period of five days. The advisories consisted of ``relative`` ash cloud concentrations in ten layers (surface-5,000 feet, 5,000--10,000 feet and every 10,000 feet to 90,000 feet). The ash was represented as a log-normal size distribution of 10--200 {mu}m diameter solid particles. Size-dependent ``ashfall`` was simulated over time as the eruption clouds dispersed. Except for an internal experimental attempt to model one of the Mount Redoubt, Alaska, eruptions (12/89), ARAC had no prior experience in modeling volcanic eruption ash hazards. For the cataclysmic eruption of 15--16 June, the complex three-dimensional atmospheric structure of the region produced dramatically divergent ash cloud patterns. The large eruptions (> 7--10 km) produced ash plume clouds with strong westward transport over the South China Sea, Southeast Asia, India and beyond. The low-level eruptions (< 7 km) and quasi-steady-state venting produced a plume which generally dispersed to the north and east throughout the support period. Modeling the sequence of eruptions presented a unique challenge. Although the initial approach proved viable, further refinement is necessary and possible. A distinct need exists to quantify eruptions consistently such that ``relative`` ash concentrations relate to specific aviation hazard categories.

Electron microscopy and phase analysis of fly ash from pressurized fluidized bed combustion

International Nuclear Information System (INIS)

Maenami, Hiroki; Isu, Norifumi; Ishida, Emile H.; Mitsuda, Takeshi

2004-01-01

The characterization of the typical fly ashes from pressurized fluidized bed combustion system (PFBC) in Japan and Europe was carried out by electron microscopy and phase analysis using energy-dispersive X-ray spectroscopy (EDX). The purity of limestone as in-bed sulfur removal sorbent influences the desulfurization reaction. The high-purity limestone yielded both hydroxyl ellestadite and anhydrite in Japanese PFBC ashes, while dolomite-rich limestone yielded anhydrite in European PFBC ashes. When the high-purity limestone was used, hydroxyl ellestadite particles were observed as the independent particles or the rim around limestone particles. The Al 2 O 3 content in the glassy phase was inversely proportional to the CaO content in the glassy phase, suggesting that the glassy phases were formed from metakaoline and calcite as end members. Since hydroxyl ellestadite, glassy phase and metakaoline are reactive under hydrothermal conditions, PFBC ashes are expected to be used as raw materials for autoclaved products

Speciation of zinc in secondary fly ashes of municipal solid waste at high temperatures

Energy Technology Data Exchange (ETDEWEB)

Yu, Meijuan; Chu, Wangsheng; Chen, Dongliang [Chinese Academy of Sciences, Beijing (China). Inst. of High Energy Physics; Tian, Shulei [Tsinghua Univ., Beijing (China). Dept. of Environmental Science and Engineering; Wang, Qi [Chinese Research Academy of Environmental Science, Beijing (China); Wu, Ziyu [Chinese Academy of Sciences, Beijing (China). Inst. of High Energy Physics; Univ. of Science and Technology of China, Hefei (China). National Synchrotron Radiation Lab.; Chinese Academy of Sciences, Beijing (China). Theoretical Physics Center for Science Facilities

2009-07-15

The evaporation aerosols produced during the vitrification process of municipal solid waste incinerators (MSWI) fly ash represent a potential environmental risk owing to their high content of heavy metals. In this research, high-temperature heating processes were carried out on fly ashes collected from bag houses in a Chinese MSWI plant and the secondary fly ashes (SFA) were separately collected at three high temperatures (1273 K, 1423 K and 1523 K) below the melting range. Elemental analysis showed that high contents of both zinc and chlorine were present in these SFA samples and, according to the standard of the heavy metals industrial grade of ore, SFAs can be re-used as metallurgical raw materials or rich ore. Moreover, as shown by XAS analysis and for different high temperatures, zinc environments in the three SFA samples were characterized by the same local structure of the zinc chloride. As a consequence, a zinc recycling procedure can be easily designed based on the configuration information. (orig.)

Speciation of zinc in secondary fly ashes of municipal solid waste at high temperatures

International Nuclear Information System (INIS)

Yu, Meijuan; Chu, Wangsheng; Chen, Dongliang; Wu, Ziyu; Univ. of Science and Technology of China, Hefei; Chinese Academy of Sciences, Beijing

2009-01-01

The evaporation aerosols produced during the vitrification process of municipal solid waste incinerators (MSWI) fly ash represent a potential environmental risk owing to their high content of heavy metals. In this research, high-temperature heating processes were carried out on fly ashes collected from bag houses in a Chinese MSWI plant and the secondary fly ashes (SFA) were separately collected at three high temperatures (1273 K, 1423 K and 1523 K) below the melting range. Elemental analysis showed that high contents of both zinc and chlorine were present in these SFA samples and, according to the standard of the heavy metals industrial grade of ore, SFAs can be re-used as metallurgical raw materials or rich ore. Moreover, as shown by XAS analysis and for different high temperatures, zinc environments in the three SFA samples were characterized by the same local structure of the zinc chloride. As a consequence, a zinc recycling procedure can be easily designed based on the configuration information. (orig.)

The reaction of acid mine drainage with fly ash from coal combustion

International Nuclear Information System (INIS)

Kim, A.G.

1999-01-01

The placement of alkaline fly ash in abandoned, reclaimed or active surface coal mines is intended to reduce the amount of acid mine drainage (AMD) produced at such sites by neutralization, inhibition of acid forming bacteria, encapsulation of the pyrite or water diversion. A continuing concern with this application is the potential release of trace elements from the fly ash when it is placed in contact with AMD. To investigate the possible release of antimony, arsenic, barium, boron, cadmium, chromium, cobalt, copper, lead, nickel, selenium, and zinc from fly ash, a series of column leaching tests were conducted. A one kg fly ash sample, placed in a 5-cm by 1 m acrylic columns, was leached at a nominal rate of 250 mL/d for between 30 and 60 days. The leachant solutions were deionized water, and dilute solutions of sulfuric acid and ferric chloride. Leaching tests have been completed on 28 fly ash samples. leachate data, analyzed as the mass extracted with respect to the concentration in the solid, indicate that the release of trace elements is variable, with only barium and zinc extracted at greater than 50 pct of the amount present in the original sample. As a comparison, water quality changes have been monitored at three sites where fly ash grout was injected after reclamation to control AMD. When compared before and after grouting, small increases in pH and decreases in acidity at discharge points were observed. Concentrations of trace metals were found to be comparable in treated and untreated areas. When grouted and ungrouted areas were compared, the effect of the fly ash was shown to be localized in the areas of injection. These studies indicated that when fly ash is used as a reagent to control of AMD, the release of trace elements is relatively small

Transcriptomic signatures of ash (Fraxinus spp. phloem.

Directory of Open Access Journals (Sweden)

Xiaodong Bai

2011-01-01

Full Text Available 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.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.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, and in future ash breeding programs for marker development.

Evidence of Coal-Fly-Ash Toxic Chemical Geoengineering in the Troposphere: Consequences for Public Health.

Science.gov (United States)

Herndon, J Marvin

2015-08-11

The widespread, intentional and increasingly frequent chemical emplacement in the troposphere has gone unidentified and unremarked in the scientific literature for years. The author presents evidence that toxic coal combustion fly ash is the most likely aerosolized particulate sprayed by tanker-jets for geoengineering, weather-modification and climate-modification purposes and describes some of the multifold consequences on public health. Two methods are employed: (1) Comparison of 8 elements analyzed in rainwater, leached from aerosolized particulates, with corresponding elements leached into water from coal fly ash in published laboratory experiments, and (2) Comparison of 14 elements analyzed in dust collected outdoors on a high-efficiency particulate air (HEPA) filter with corresponding elements analyzed in un-leached coal fly ash material. The results show: (1) the assemblage of elements in rainwater and in the corresponding experimental leachate are essentially identical. At a 99% confidence interval, they have identical means (T-test) and identical variances (F-test); and (2) the assemblage of elements in the HEPA dust and in the corresponding average un-leached coal fly ash are likewise essentially identical. The consequences on public health are profound, including exposure to a variety of toxic heavy metals, radioactive elements, and neurologically-implicated chemically mobile aluminum released by body moisture in situ after inhalation or through transdermal induction.

Effect of industrial residue combinations on availability of elements

Energy Technology Data Exchange (ETDEWEB)

Brännvall, Evelina, E-mail: evelina.brannvall@ltu.se [Waste Science and Technology, Luleå University of Technology, 97187 Luleå (Sweden); Zamora, Carles Belmonte [Waste Science and Technology, Luleå University of Technology, 97187 Luleå (Sweden); Sjöblom, Rolf [Waste Science and Technology, Luleå University of Technology, 97187 Luleå (Sweden); Tekedo AB, Spinnarvägen 10, 611 37 Nyköping (Sweden); Kumpiene, Jurate [Waste Science and Technology, Luleå University of Technology, 97187 Luleå (Sweden)

2014-07-15

Highlights: • Beneficial combination of fly ash and biosolids. • Nutrient availability increase. • Potentially toxic element availability decrease. • Measured element availability was differed from the calculated leaching potential. - Abstract: Industrial residues, such as fly ashes and biosolids, contain elements (e.g., N, P, K, S, Ca and Zn) that make them a viable alternative for synthetic fertilizers in forestry and agriculture. However, the use of these materials is often limited due to the presence of potentially toxic substances. It is therefore necessary to assess and, when warranted, modify the chemical and physical form of these and similar waste materials before any advantages are taken of their beneficial properties. Biofuel fly ash, municipal solid waste incineration (MSWI) fly ash, biosolids, peat, peat residues and gypsum board waste were combined in various proportions, and this resulted in increased leaching of N, P, S, Cu and Mn, but decreased leaching of Ca, K, Mg, Cr, Fe, Ni, Zn, Al, As and Pb. Chemical fractionation revealed that elements Ca, K, Mg, S and Mn were predominantly exchangeable, while the rest of the elements were less mobile. Cadmium was mostly exchangeable in MSWI fly ash, but less mobile in biofuel fly ash mixtures. Recycling of MSWI fly ash in the mixtures with fertilizers is considerably less attractive, due to the high levels of salts and exchangeable Cd.

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

Life cycle adaption of biofuel ashes. Evaluation of new techniques for pelletizing of biofuel ashes, especially regarding operational properties and environmental effects in the forest after ash recycling. Stage 1

International Nuclear Information System (INIS)

Loevgren, Linnea; Lundmark, Jan-Erik; Jansson, Charlotta

2000-11-01

greater acid neutralisation capacity. Wood ash differs from lime in that it contains a substantial amount of nutrient elements essential for the forest. The acid neutralisation capacity of the roll pelleted ash was still the same after 100 days of laboratory leaching. The acid neutralisation capacity of self-hardened and crushed ashes usually ceases already after 30 days. It is likely that a well-hardened roll pelleted ash product can, without any great risk of serious damage to ground vegetation, be recycled to the forest during the clearcut stage as a compensation fertiliser following biofuel harvesting. Neither increased nitrification nor leaching of nitrate from soil water is likely to occur. Potassium is considered to be an element that is easily leached from ash. In our laboratory leaching study, on the other hand, as much as 61 % of the original potassium content was still present in the roll pelleted ash after 100 days. The roll pelleting machine has been running a little more than six months at the two mills. In total 1500 tonnes of pellets have been produced. The main part is pellets solely from ash, however, mixtures of ash and lime sludge and ash and green liquor sludge, respectively, have also been pelleted. Our experiences of the roll pelleting machine are very good. The ash products seem well suited to recycling back to the forest. The machine has a production capacity of five tonnes per hour, indicating a production capacity of 10,000 tonnes per year. The running costs, including costs for personnel, spare parts and internal transports, amounted to 87 SEK per tonne of dry ash (i.e. 61 SEK per tonne of ash with 30 % water content) during the long term test. These are low costs compared to other agglomeration techniques. The roll pelleting technique has worked very well on a large scale without any further technical development. As this machine was the first of its kind some adjustments and minor changes were made in the machine and container during the

Ash fusion temperatures and the transformations of coal ash particles to slag

Energy Technology Data Exchange (ETDEWEB)

Gupta, S.; Wall, T.F.; Creelman, R.A.; Gupta, R. [Univ. of Newcastle, Callaghan (Australia)

1996-12-31

A mechanistic study is detailed in which coal ash is heated with its shrinkage measured continuously up to a temperature of 1600{degrees}C. The temperatures corresponding to the rapid rate of shrinkage are shown to correspond to the formation of eutectics identified on phase diagrams. Samples were therefore heated to these temperatures, cooled rapidly and examined with an SEM to identify the associated chemical and physical changes. The progressive changes in the range of chemical analysis (from SEM), the extent of undissolved ash particles and porosity were then quantified and related to homogenization, viscosity and ash fusion mechanisms.

Ash fusion temperatures and the transformations of coal ash particles to slag

Energy Technology Data Exchange (ETDEWEB)

Wall, T.F.; Creelman, R.A.; Gupta, R.; Gupta, S. [Univ. of Newcastle (Australia)

1996-10-01

A mechanistic study is detailed in which coal ash is heated with the shrinkage and electrical resistance measured continuously up to a temperature of 1600{degrees}C. The temperatures corresponding to rapid rates of shrinkage are shown to correspond to the formation of eutectics identified on phase diagrams. Samples where therefore heated to these temperatures, cooled rapidly and examined with an SEM to identify the associated chemical and physical changes. The progressive changes in the range of chemical analysis (from SEM), the extent of undissolved ash particles and porosity are then quantified and related to the shrinkage events and standard ash fusion temperatures.

The role of sample preparation in interpretation of trace element concentration variability in moss bioindication studies

Science.gov (United States)

Migaszewski, Z.M.; Lamothe, P.J.; Crock, J.G.; Galuszka, A.; Dolegowska, S.

2011-01-01

Trace element concentrations in plant bioindicators are often determined to assess the quality of the environment. Instrumental methods used for trace element determination require digestion of samples. There are different methods of sample preparation for trace element analysis, and the selection of the best method should be fitted for the purpose of a study. Our hypothesis is that the method of sample preparation is important for interpretation of the results. Here we compare the results of 36 element determinations performed by ICP-MS on ashed and on acid-digested (HNO3, H2O2) samples of two moss species (Hylocomium splendens and Pleurozium schreberi) collected in Alaska and in south-central Poland. We found that dry ashing of the moss samples prior to analysis resulted in considerably lower detection limits of all the elements examined. We also show that this sample preparation technique facilitated the determination of interregional and interspecies differences in the chemistry of trace elements. Compared to the Polish mosses, the Alaskan mosses displayed more positive correlations of the major rock-forming elements with ash content, reflecting those elements' geogenic origin. Of the two moss species, P. schreberi from both Alaska and Poland was also highlighted by a larger number of positive element pair correlations. The cluster analysis suggests that the more uniform element distribution pattern of the Polish mosses primarily reflects regional air pollution sources. Our study has shown that the method of sample preparation is an important factor in statistical interpretation of the results of trace element determinations. ?? 2010 Springer-Verlag.

Leaching of biomass from semi-natural grasslands – Effects on chemical composition and ash high-temperature behaviour

International Nuclear Information System (INIS)

Tonn, Bettina; Thumm, Ulrich; Lewandowski, Iris; Claupein, Wilhelm

2012-01-01

Combustion of biodiversity-rich semi-natural grassland biomass no longer needed for forage allows nature conservation to be combined with bioenergy production. Natural leaching by rainfall during the period between biomass harvest and collection can reduce the content of elements detrimental for the combustion of grassland biomass. This study assesses the influence of biomass characteristics on leaching efficiency and the potential effects of leaching on ash melting behaviour and elemental release. Grassland biomass harvested from five sites at two harvest dates was leached at two intensities. Low-temperature ash was heated to 700, 800, 900 and 1000 °C respectively and classified into four ash fusion classes. Ash mass loss was determined as a measure of high-temperature elemental release. Weather data were used to calculate the frequency of weather conditions favourable to on-field leaching. K and Cl were leached most strongly and were reduced by 30 and 45% respectively by a leaching treatment corresponding to 30–40 mm of rain. The effects of site and harvest date on leaching efficiency were significant but small. Ash melting behaviour and elemental release between 700 and 900 °C were favourably influenced by leaching. The K/(Ca + Mg) and Si/ash ratios were related to increased ash melting. In this respect, semi-natural grassland biomass differs from other, less Ca-rich, herbaceous biofuels. Even if suitable weather conditions are not occurring frequently at the study sites, on-field leaching can offer an additional low-cost, on-farm strategy option for farmers and nature conservation agencies to improve biomass quality of nature conservation grasslands for combustion. -- Graphical abstract: Highlights: ► Combustion of biomass from biodiversity-rich nature conservation grassland. ► Leaching by rain during the field period reduces K and Cl concentrations. ► Increasing K/(Ca + Mg) and decreasing (K + Ca + Mg)/ash ratios increase ash melting. ► Leaching

Investigation of different types of filters for atmospheric trace elements analysis by three analytical techniques

International Nuclear Information System (INIS)

Ali, A.E.; Bacso, J.

1996-01-01

Different atmospheric aerosol samples were collected on three types of filters. Disks of both loaded and clean areas of each kind of filter were investigated by XRF, PIXE and Scanning Electron Microscope (SEM) methods. The blank concentration values of the elements Al, Si, P, S, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Br and Pb in the three types of filters are discussed. It is found that for trace elemental analysis, the Nuclepore membrane filters are the most suitable for sampling. These have much lower blank element concentration values than the glass fibres and ash free filters. It was found also that the PIXE method is a more reliable analytical technique for atmospheric aerosol particles than the other methods. (author). 20 refs., 3 figs., 3 tabs

Leachates from wood ash - effects of storage on soil; Lakvatten fraan skogsbraensleaska - markpaaverkan av lagring

Energy Technology Data Exchange (ETDEWEB)

Valeur, Inger; Thelin, Gunnar (EkoBalans FenixAB, Lund (Sweden))

2012-02-15

In this study we monitored leachate from wood ash stored in a pile in an outdoor environment during six months. Our aim was to contribute with knowledge about leaching behavior and risks connected to storages of wood ash, and more generally leaching from piles affected by various weather conditions. Impacts on soil from storage of wood ash was also included in the study as well as different transport scenarios for recycling wood ash to the forest. Bioenergy output from Swedish forests has more than doubled the last 10 years and as nutrient rich parts as needles and branches (grot) is also taken out, the nutrient export from the forest site has increased by a factor of three to five. To counteract depletion of nutrients in forest soils, wood ash is returned to the forest. Apart from nitrogen, wood ash contains all the nutrients and trace elements that were in the wood before combustion. The wood ash must be hardened before spreading to make it less reactive. The ash self hardens when stored in an outdoor environment for 3 to 6 months and according to the waste act this should be done on a paved area. However, wood ash which is meant to be recycled to the forest has naturally very low amounts of polluting elements and shall also fulfill limit values, set up by the Swedish Forest Agency. As it is so that the storage is during a limited period of time and the ash shall be transported, not only to one place but too several smaller areas, this has given rise to the thought of storing the ash closer to the spreading area. However, the ash would then probably be stored in a non paved area, as the number of paved areas in forests is scarce. If storage close to the spreading area could be done, the distance for transports connected to recycling the ash would presumably be decrease by a factor of two or three. To get permission to store ash on a non paved area, there must be enough data available which can ensure that there are no environmental risks associated to the storage

Physiological effect of accidental fly ash deposition on plants and chemical study of the dusted plant leaves by XRP and EPMA

Energy Technology Data Exchange (ETDEWEB)

Osan, J.; Torok, S.; Torok, K.; Nemeth, L.; Labar, J.L. [KFTI Atomic Energy Research Institute, Budapest (Hungary)

1996-07-01

Studies on the influence of fly ash on the photosynthetic activity of Solidago canadensis L. were carried out in order to determine the importance of this material as an environmental impact agent. Leaf samples were dusted with fly ash and sprayed with water of different pH values simulating acid rain. Fly ash was applied in quantities to model an accidental occasion of an extremely high emission level of fly ash as a result of malfunctioning of the electrostatic filters of fossil fuel-burning power plants. Leaf samples were analysed to trace the distribution of fly ash compounds on the leaf epidermis by means of x-ray fluorescence (XRF) analysis and single-particle electron probe microanalysis (EPMA). Significant reduction of the photosynthetic activity compared with the control group was observed only when the dusted plants were sprayed with acid rain. The trace element study showed that the uptake of toxic elements by plants was not significant. A quartz microcrystal layer in the case of acid treatment was detected by EPMA, and covered the entire leaf surface. It is considered that this layer, in addition to the fly ash particles themselves, absorbed light significantly, which played an important role in the decrease in photosynthetic activity.

Nutritional composition, antinutritional factors and elemental ...

African Journals Online (AJOL)

The study is aimed at evaluating nutritional composition, antinutritional factors and elemental analysis of three parts (roots sample RS, seed sample SS and leave sample LS) of Nymphaea lotus (water lily) using standard methods. The plant parts were analyzed for the content of crude lipid, crude fiber, crude proteins, ash, ...

Losses of radionuclides related to high temperature ashing

International Nuclear Information System (INIS)

Carlsson, G.

1985-01-01

When measuring radionuclides in samples from the environment of nuclear power plants, a sample preparation step, such as high temperature ashing is often necessary. Althoug much used, this method is subject to controversy because of the risk of losses of several elements. A study, including the ashing of synthetically prepared samples has been undertaken. Controlled and moderate temperature rise rate and a final temperature not exceeding 550 deg. C has been shown vital for recovery

Application of neutron activation analysis for determination of elements in field of public health science

International Nuclear Information System (INIS)

Iijima, Ikuyo

2010-01-01

Outline of neutron activation analysis (NAA) and application examples of this method to ensure safety of food and environment are explained. It consists of four chapters such as introduction, what is NAA, quality control of NAA, application examples of NAA for determination of the elements in the field of public health science. The quality control of NAA is carried out by using certified reference materials, identification of individual difference of sample, and homogeneity of samples. Some application examples of NAA for determination Cd in rice, Hg and As in fish, U in soil, food and aerosol, 128 I and 129 I in environment, Cs and 133 Cs in mushroom, the essential elements and trace elements in food are reported. Analytical results of elements in certified reference materials, content of elements in ashed samples (carrots and bamboo shoots), average use frequency of ingredients in a sample, and correlation between Cs and 137 Cs in mushroom are illustrated. (S.Y.)

STUDY ON POZZOLANA ACTIVITY OF WHEAT STRAW ASH AS POTENTIAL ADMIXTURE FOR BLENDED CEMENTS

Directory of Open Access Journals (Sweden)

Ondrej Jankovsky

2017-09-01

Full Text Available Wheat straw ash coming from combustion of packed wheat straw was studied as a potential pozzolana active admixture for blended cements. X-Ray fluorescence, X-Ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy were used to examine chemical and mineralogical composition, morphology and elemental distribution of a raw untreated ash. Due to high carbon content, the wheat straw ash was thermally treated for 2 hours at 700 °C and analyzed again using the same analytic techniques. Thermal treatment process was monitored using simultaneous thermal analysis and Fourier Transform infrared spectroscopy. The pozzolana activity was assessed using Chapelle and Frattini tests. In the next step, wheat straw ash was used for preparation of blended cement pastes. The content of ash in the blends was 10, 15, and 20% by mass. For the hardened pastes, basic physical properties, mechanical parameters, and pore size distribution were measured. For fresh past mixes, workability was tested. Moreover, leachability of chlorides, nitrates, sulfates and alkalis from paste samples was studied. The experimentally obtained data pointed to the high pozzolana activity of wheat straw ash and sufficient mechanical properties of cement pastes with the ash content up to 20 mass% of cement. In summary, the analyzed waste product from biomass combustion was found to be applicable as a part of cement-based blended binder providing economic and environmental benefits for concrete industry.

Oral bioavailability of arsenic, antimony and a selection of metals in ashes; Oral biotillgaenglighet av arsenik, antimon och ett urval av metaller i askor

Energy Technology Data Exchange (ETDEWEB)

Carlsson, Christel; Bendz, David; Jones, Celia

2008-06-15

In an earlier study, financed by Varmeforsk, 'Q4-238 Environmental guidelines for reuse of ash in civil engineering applications', the total content of arsenic and lead was shown to determine whether or not reuse of some of the ashes in construction work is feasible. The model used to calculate the guidelines uses the total concentration of metals to evaluate the health risks resulting from exposure to the ashes. The use of total concentration can lead to overly conservative risk assessments if a significant fraction of the total metal content is not bioavailable. Better precision in the risk assessment can be given by the use of the bioavailable fraction of arsenic and lead in the model. As a result, ashes which are rejected on the basis of total metal concentration may be acceptable for use in engineering construction when the assessment is based on the bioavailable fraction. The purpose of the study was to (i) compile information on the oral bioavailability of arsenic, antimony and a selection of metals in ashes and similar materials, and on in vitro methods for determination of oral bioavailability, and (ii) experimentally estimate oral bioavailability of arsenic, antimony and some metals in a selection of ashes by analysis of the gastrointestinal bioaccessibility of these elements. The investigated elements were antimony, arsenic, lead, cadmium, copper, chromium, nickel and zinc. In the literature study performed within the project a number of static and dynamic in vitro methods simulating gastrointestinal processes of contaminants were compiled. The methods include one or several segments, i.e. mouth, stomach and intestine. Among the compiled methods, the RIVM (Rijksinstituut voor volksgesundheid en milieu) in vitro method was used in the experimental part of the project. The advantages with the method was that: the method to a high degree mimicked the human gastrointestinal processes (the method included three segments mouth, stomach, and intestine

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

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-03-15

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

Prevention of trace and major element leaching from coal combustion products by hydrothermally-treated coal ash

Energy Technology Data Exchange (ETDEWEB)

Adnadjevic, B.; Popovic, A.; Mikasinovic, B. [University of Belgrade, Belgrade (Serbia). Dept. of Chemistry

2009-07-01

The most important structural components of coal ash obtained by coal combustion in 'Nikola Tesla A' power plant located near Belgrade (Serbia) are amorphous alumosilicate, alpha-quartz, and mullite. The phase composition of coal ash can be altered to obtain zeolite type NaA that crystallizes in a narrow crystallization field (SiO{sub 2}/Al{sub 2}O{sub 3}; Na{sub 2}O/SiO{sub 2}; H{sub 2}O/Na{sub 2}O ratios). Basic properties (crystallization degree, chemical composition, the energy of activation) of obtained zeolites were established. Coal ash extracts treated with obtained ion-exchange material showed that zeolites obtained from coal ash were able to reduce the amounts of iron, chromium, nickel, zinc, copper, lead, and manganese in ash extracts, thus proving its potential in preventing pollution from dump effluent waters.

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

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 can however exceed these target values. The low leaching of elements such as Cd, Cr, Ni, Pb and Zn at L/S 10 results in that almost all values in the sample test are below the target values for waste that can be disposed in to landfills for inert waste, i.e. far below preliminary target values for use of secondary materials in subbase layers. Environmental assessments based on leaching as a function of L/S should instead focus on other elements such as Cu, Mo, SO{sub 4}{sup 2,} Cl{sup a}nd Sb. Besides, the leaching of Cl{sup a}nd SO{sub 4}{sup 2c}ould be a problem for the use of bottom ash in subbase layers. Our calculations indicate that at least 2 samples should be collected and analyzed from a storage heap containing = 30 tonnes of bottom ash. The calculations are dependent on the target values used and therefore the requirements can change if other target values are used. Nordtest NT ENVIR 004 recommends that at least 5 samples (N=5) are collected and analyzed. If instead a storage heap contains 5,000 tonnes and N=5, 65 subsamples should be collected and combined into composite samples according to our calculations. If the amount of bottom ash is increased to 25,000 tonnes, 145 subsamples should be collected. We have not specified the number of composite samples, since clear instructions about this procedure is missing in our background material. If the maximum particle size for bottom ash is 45 mm, samples and subsamples should contain at least 2.5 liter bottom ash according to our calculations. General connections between pH and the availability or the leachability of different elements which could be used to identify extreme leaching properties in bottom ash seem to be missing. There is also a lack of general connections that could be used to estimate the leachability of different elements from the

Ash chemistry and sintering, verification of the mechanisms

Energy Technology Data Exchange (ETDEWEB)

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

1996-12-01

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

Evidence of Coal-Fly-Ash Toxic Chemical Geoengineering in the Troposphere: Consequences for Public Health

Directory of Open Access Journals (Sweden)

J. Marvin Herndon

2015-08-01

Full Text Available The widespread, intentional and increasingly frequent chemical emplacement in the troposphere has gone unidentified and unremarked in the scientific literature for years. The author presents evidence that toxic coal combustion fly ash is the most likely aerosolized particulate sprayed by tanker-jets for geoengineering, weather-modification and climate-modification purposes and describes some of the multifold consequences on public health. Two methods are employed: (1 Comparison of 8 elements analyzed in rainwater, leached from aerosolized particulates, with corresponding elements leached into water from coal fly ash in published laboratory experiments, and (2 Comparison of 14 elements analyzed in dust collected outdoors on a high-efficiency particulate air (HEPA filter with corresponding elements analyzed in un-leached coal fly ash material. The results show: (1 the assemblage of elements in rainwater and in the corresponding experimental leachate are essentially identical. At a 99% confidence interval, they have identical means (T-test and identical variances (F-test; and (2 the assemblage of elements in the HEPA dust and in the corresponding average un-leached coal fly ash are likewise essentially identical. The consequences on public health are profound, including exposure to a variety of toxic heavy metals, radioactive elements, and neurologically-implicated chemically mobile aluminum released by body moisture in situ after inhalation or through transdermal induction.

Trace elements partitioning during coal combustion in fluidized bed under O{sub 2}/CO{sub 2} atmosphere

Energy Technology Data Exchange (ETDEWEB)

Li, Haixin; Zhao, Changsui; Liang, Cai; Duan, Lunbo; Chen, Huichao [Southeast Univ., Nanjing (China). School of Energy and Environment

2013-07-01

Experiments were conducted to investigate the effects of temperature and O{sub 2}/CO{sub 2} atmosphere on trace elements (Cr, Mn, Co, Ni, Cd, Pb, Hg, As, Se) partitioning during combustion of Xuzhou bituminous coal in a 6 kWth fluidized bed. Inductively coupled plasma mass spectrometry (ICP-MS) and atomic fluorescence spectrometry (AFS) were used to determine trace elements contents in raw coal, bottom ash, fly ash and flue gas. The results indicate that with bed temperature increase, the relative enrichment of all the trace elements except Cr in bottom ash decreases suggesting that their volatility is enhanced. The relative enrichments of hardly volatile elements, like Cr and Mn in fly ash increase with bed temperature increase while those of partially volatile and highly volatile elements in fly ash are opposite. The relative enrichments of trace elements except Cr and Mn in fly ash are higher than those in bottom ash. Increasing bed temperature promotes elements like As, Se and Hg to migrate to vapor phase, Mn to migrate to fly ash and Cr to migrate to both bottom ash and fly ash. 21%O{sub 2}/79%CO{sub 2} atmosphere improves the volatility of Cr, Mn, Co, Se and their migration to fly ash, while restrains the volatility of As, Ni, Pb. It has little effect on the volatility of Hg but improves its migration to fly ash. Mass balance ratio was also calculated to observe trace elements distribution in bottom ash, fly ash and flue gas. There is no much difference in trace elements distribution between the two atmospheres. It can be seen that the trace elements proportion in fly ash is much greater, and more than 40% of Hg is distributed in the gas phase. Most of Hg and Se volatilize during combustion. The mass balance ratios are 87 {proportional_to} 129% which is considered acceptable.

Metal mobilization under alkaline conditions in ash-covered tailings.

Science.gov (United States)

Lu, Jinmei; Alakangas, Lena; Wanhainen, Christina

2014-06-15

The aim of this study was to determine element mobilization and accumulation in mill tailings under alkaline conditions. The tailings were covered with 50 cm of fly ash, and above a sludge layer. The tailings were geochemically and mineralogically investigated. Sulfides, such as pyrrhotite, sphalerite and galena along with gangue minerals such as dolomite, calcite, micas, chlorite, epidote, Mn-pyroxene and rhodonite were identified in the unoxidized tailings. The dissolution of the fly ash layer resulted in a high pH (close to 12) in the underlying tailings. This, together with the presence of organic matter, increased the weathering of the tailings and mobilization of elements in the uppermost 47 cm of the tailings. All primary minerals were depleted, except quartz and feldspar which were covered by blurry secondary carbonates. Sulfide-associated elements such as Cd, Fe, Pb, S and Zn and silicate-associated elements such as Fe, Mg and Mn were released from the depletion zone and accumulated deeper down in the tailings where the pH decreased to circum-neutral. Sequential extraction suggests that Cd, Cu, Fe, Pb, S and Zn were retained deeper down in the tailings and were mainly associated with the sulfide phase. Calcium, Cr, K and Ni released from the ash layer were accumulated in the uppermost depletion zone of the tailings. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

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

Science.gov (United States)

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

2016-01-01

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

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...... ashes. The process, thus, fixates the metals in the solid residues without altering the leaching properties of the bottom ash too significantly. (C) 2001 Elsevier Science Ltd. All rights reserved....... 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...

Determining the elemental composition of fuels by bomb calorimetry and the inverse correlation of HHV with elemental composition

Energy Technology Data Exchange (ETDEWEB)

Bech, Niels; Jensen, Peter Arendt; Dam-Johansen, Kim [Department of Chemical and Biochemical Engineering, CHEC Research Centre, Technical University of Denmark, Soeltofts Plads, Building 229, DK-2800 Kongens Lyngby (Denmark)

2009-03-15

This article presents a method to obtain a simplified elemental analysis of an organic sample in which oxygen, nitrogen, and sulphur are lumped. The method uses a bomb calorimeter, water, and ash measurements combined with a numerical procedure based on a generalised equation for predicting higher heating value. By analysing pure organic substances, literature data, and fuels it is demonstrated that the method can provide hydrogen estimates within {+-}0.7% daf. and carbon and sum of oxygen, nitrogen, and sulphur estimates within {+-}2% daf. for fuels containing less than 90% ash db., 2% nitrogen daf., and 1% daf. sulphur. (author)

Properties of ash generated during sewage sludge combustion: A multifaceted analysis

International Nuclear Information System (INIS)

Magdziarz, Aneta; Wilk, Małgorzata; Gajek, Marcin; Nowak-Woźny, Dorota; Kopia, Agnieszka; Kalemba-Rec, Izabela; Koziński, Janusz A.

2016-01-01

This paper presents chemical properties of sewage sludge ashes required for determining their thermal characteristics. A novel approach, linking selected advanced analytical techniques with FactSage modelling, was developed and applied to obtain new information on deposit formation mechanisms that contribute to fouling and slagging. The mineral matter and fusion temperatures were investigated using a variety of analytical techniques including XRF, ICP-MS, XRD, SEM-EDX and AFT. The slagging and fouling indices were calculated and the sintering properties were predicted. The studied ashes were rich in P_2O_5, CaO, SiO_2 and Fe_2O_3, but their concentrations slightly differed. Phase analyses suggested the existence of calcium and phosphorus as main phases. Thermal behaviour of ashes was studied focusing on the mass loss, temperature peaks and thermic effects with the increasing of temperature up to 1200 °C under air atmosphere. The changes in concentration of ash compounds contributed to differences in ash fusion temperatures. FactSage thermochemical equilibrium calculations were used to predict the amount of liquid slag and solid phases, giving information about slagging properties of ashes. The general conclusion based on experimental studies is that sewage sludge ashes cause the slagging and fouling hazard while they reveal low corrosive effect. - Highlights: • Characterisation of sewage sludge ashes were given. • Transformation of inorganic components was determined using XRD and FTIR. • The ash fusion behaviour of ashes was studied experimentally. • Empirical indices were calculated indicating slagging and fouling propensities. • Thermodynamic equilibrium calculation was used.

Mercury adsorption characteristics of HBr-modified fly ash in an entrained-flow reactor.

Science.gov (United States)

Zhang, Yongsheng; Zhao, Lilin; Guo, Ruitao; Song, Na; Wang, Jiawei; Cao, Yan; Orndorff, William; Pan, Wei-ping

2015-07-01

In this study, the mercury adsorption characteristics of HBr-modified fly ash in an entrained-flow reactor were investigated through thermal decomposition methods. The results show that the mercury adsorption performance of the HBr-modified fly ash was enhanced significantly. The mercury species adsorbed by unmodified fly ash were HgCl2, HgS and HgO. The mercury adsorbed by HBr-modified fly ash, in the entrained-flow reactor, existed in two forms, HgBr2 and HgO, and the HBr was the dominant factor promoting oxidation of elemental mercury in the entrained-flow reactor. In the current study, the concentration of HgBr2 and HgO in ash from the fine ash vessel was 4.6 times greater than for ash from the coarse ash vessel. The fine ash had better mercury adsorption performance than coarse ash, which is most likely due to the higher specific surface area and longer residence time. Copyright © 2015. Published by Elsevier B.V.

Determination of ash concentration and coal calorific values of coal directly on the conveyor belt; Bestimmung der Aschegehalte und Heizwerte von Kohlen direkt auf dem Foerderband

Energy Technology Data Exchange (ETDEWEB)

Wess, Juergen [PANalytical GmbH, Kassel (Germany)

2012-07-01

Among the multi-element methods of instrumental analyses, the neutron activation analysis takes a special position. The method is able to penetrate even thick layers of samples and covers whole mass flows online, like on conveyor belts. A new technique of pulsed excitation allows the reduction of undesired components of analytical gamma-rays, which allows the determination of carbon, oxygen and hydrogen. Therefore, the ash content, based on the ash containing elements, and the calorific values, based on calculation models, can be measured in one process. (orig.)

Characterising boiler ash from a circulating fluidised bed municipal solid waste incinerator and distribution of PCDD/F and PCB.

Science.gov (United States)

Zhang, Mengmei; Buekens, Alfons; Li, Xiaodong

2018-05-31

In this study, ash samples were collected from five locations situated in the boiler of a circulating fluidised bed municipal solid waste incinerator (high- and low-temperature superheater, evaporator tubes and upper and lower economiser). These samples represent a huge range of flue gas temperatures and were characterised for their particle size distribution, surface characteristics, elemental composition, chemical forms of carbon and chlorine and distribution of polychlorinated dibenzo-p-dioxins (PCDD), dibenzofurans (PCDF) and biphenyls (PCB). Enrichment of chlorine, one of the main elements of organochlorinated pollutants, and copper, zinc and lead, major catalytic metals for dioxin-like compounds, was observed in lower-temperature ash deposits. The speciation of carbon and chlorine on ash surfaces was established, showing a positive correlation between organic chlorine and oxygen-containing carbon functional groups. The load of PCDD/F and PCB (especially dioxin-like PCB) tends to rise rapidly with falling temperature of flue gas, reaching their highest value in economiser ashes. The formation of PCDD/F congeners through the chlorophenol precursor route apparently was enhanced downstream the boiler. Principal component analysis (PCA) was applied to study the links between the ash characteristics and distribution of chloro-aromatics. The primary purpose of this study is improving the understanding of any links between the characteristics of ash from waste heat systems and its potential to form PCDD/F and PCB. The question is raised whether further characterisation of fly ash may assist to establish a diagnosis of poor plant operation, inclusive the generation, destruction and eventual emission of persistent organic pollutants (POPs).

Mechanical properties and microstructure analysis of fly ash geopolymeric recycled concrete

International Nuclear Information System (INIS)

Shi, X.S.; Collins, F.G.; Zhao, X.L.; Wang, Q.Y.

2012-01-01

Highlights: ► Sodium silicate solution and sodium hydroxide solution were used to activate fly ash, which substitute cement totally in the concrete. ► Utilizing two kinds of waste materials (fly ash and recycled aggregates) at the same time. ► The mechanical properties and microstructures were studied and compared with different recycled aggregates replacement ratios. ► Such concrete has greater compressive strength and better microstructure than ordinary concrete and also geopolymer concrete. - Abstract: Six mixtures with different recycled aggregate (RA) replacement ratios of 0%, 50% and 100% were designed to manufacture recycled aggregate concrete (RAC) and alkali-activated fly ash geopolymeric recycled concrete (GRC). The physical and mechanical properties were investigated indicating different performances from each other. Optical microscopy under transmitted light and scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX) were carried out in this study in order to identify the mechanism underlying the effects of the geopolymer and RA on concrete properties. The features of aggregates, paste and interfacial transition zone (ITZ) were compared and discussed. Experimental results indicate that using alkali-activated fly ash geopolymer as replacement of ordinary Portland cement (OPC) effectively improved the compressive strength. With increasing of RA contents in both RAC and GRC, the compressive strength decreased gradually. The microstructure analysis shows that, on one hand, the presence of RA weakens the strength of the aggregates and the structure of ITZs; on the other hand, due to the alkali-activated fly ash in geopolymer concrete, the contents of Portlandite (Ca(OH) 2 ) and voids were reduced, as well as improved the matrix homogeneity. The microstructure of GRC was changed by different reaction products, such as aluminosilicate gel.

Temporal evolution of wildfire ash and its implications for water pollution

Science.gov (United States)

Santin, Cristina; Doerr, Stefan H.; Otero, Xose L.; Chafer, Chris J.

2015-04-01

soluble major and trace elements. 'Aged ash' was richer in soil-derived elements (Al, Si and Fe) and exhibited higher bulk density and a lower rainfall storage capacity. We will discuss the similarities and differences between 'fresh' and 'aged' ash properties and identify the potential main threats to water quality derived from each of them. The water contamination potential from wildfire ash varies depending, among other factors, on the time between the production and transport of the ash into the hydrological system. Therefore, to evaluate the threat of wildfire ash to water quality, not only its intrinsic characteristics, but also its temporal evolution in conjunction with the probability of ash erosion to occur at a given time, need to be evaluated. These additional parameters highlight the complexity of the interaction of many different factors in the post-fire landscape.

Effect of wood ash application on soil solution chemistry of tropical acid soils: incubation study.

Science.gov (United States)

Nkana, J C Voundi; Demeyer, A; Verloo, M G

2002-12-01

The objective of this study was to determine the effect of wood ash application on soil solution composition of three tropical acid soils. Calcium carbonate was used as a reference amendment. Amended soils and control were incubated for 60 days. To assess soluble nutrients, saturation extracts were analysed at 15 days intervals. Wood ash application affects the soil solution chemistry in two ways, as a liming agent and as a supplier of nutrients. As a liming agent, wood ash application induced increases in soil solution pH, Ca, Mg, inorganic C, SO4 and DOC. As a supplier of elements, the increase in the soil solution pH was partly due to ligand exchange between wood ash SO4 and OH- ions. Large increases in concentrations of inorganic C, SO4, Ca and Mg with wood ash relative to lime and especially increases in K reflected the supply of these elements by wood ash. Wood ash application could represent increased availability of nutrients for the plant. However, large concentrations of basic cations, SO4 and NO3 obtained with higher application rates could be a concern because of potential solute transport to surface waters and groundwater. Wood ash must be applied at reasonable rates to avoid any risk for the environment.

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

Quality characteristics of Greek fly ashes and potential uses

Energy Technology Data Exchange (ETDEWEB)

Skodras, G.; Grammelis, P.; Kakaras, E. [Institute for Solid Fuels Technology and Applications, Ptolemais (Greece); Karangelos, D.; Anagnostakis, M.; Hinis, E. [Nuclear Engineering Section, Mechanical Engineering Department, National Technical University of Athens, Athens (Greece)

2007-01-15

The main characteristics of fly ash from Greek coal-fired boilers are presented in this paper in relation to its exploitation potential. Both fuel and fly ash samples were collected and analyzed according to the ASTM Standards. Apart from the typical analyses (proximate, ultimate, ash analysis and calorific value), an ICP-AES spectrometer was used for the analysis of heavy metals in the ash. Experimental measurements in order to determine the radioactivity content of raw fuel and the fly ash were carried out as well. A representative fly ash sample from Ptolemais power plant was evaluated and tested as filler in Self-Compacting Concrete (SCC). Ashes from the Greek brown coal are classified in type C, most of the fly ash being produced in Ptolemais of Northern Greece, while the rest in Megalopolis. Ptolemais fly ash is rich in calcium compounds, while Megalopolis fly ash contains more pyrite. Increased heavy metal concentrations are observed in the fly ash samples of Greek coal. Greek fly ash appears to have not only pozzolanic but also hydraulic behaviour. Furthermore, Greek fly ash, depending on its origin, may have relatively high natural radioactivity content, reaching in the case of Megalopolis fly ash 1 kBq kg{sup -1} of {sup 226}Ra. The laboratory results showed that fly ashes can be a competitive substitute to conventional limestone filler material in SCC. Fly ash is mostly used in Greece in cement industry replacing cement clinker and aiming to the production of special types of Portland cements. However, a more aggressive utilisation strategy should be developed, since low quantities of the total produced fly ash are currently further utilised. (author)

Ash-forming elements in four Scandinavian wood species part 3: Combustion of five spruce samples

Energy Technology Data Exchange (ETDEWEB)

Werkelin, Johan; Lindberg, Daniel; Skrifvars, Bengt-Johan; Hupa, Mikko [Aabo Akademi Process Chemistry Centre, Piispankatu 8, FI-20500 Turku (Finland); Bostroem, Dan [Energy Technology and Thermal Process Chemistry, Umeaa University, SE-901 87 Umeaa (Sweden)

2011-01-15

Forest residue is the remaining fraction after the outtake of timber, which comprises the tree tops and branches. It may as fuel cause damage to the combustion device through ash slagging and fouling. The objective of this work was to model the ash composition from well-specified samples of a spruce tree: wood, bark, twigs, needles, and shoots. Their ash at 1000 C was modelled using global chemical equilibrium calculations, and laboratory-made ash of the five samples was analyzed by XRD and SEM-EDXA. According to the results, the risk of slagging arises from the spruce foliage: molten alkali silicates from spruce needles and probably molten alkali phosphates from spruce shoots may cause problems in the furnace. Fouling caused by condensing alkali vapours can be produced by all five samples. The amount of alkali vapours in the flue gas was in the same order of magnitude for all five samples, in spite of large differences in their original alkali contents. (author)

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

Phosphorus recovery and leaching of trace elements from incinerated sewage sludge ash (ISSA).

Science.gov (United States)

Fang, Le; Li, Jiang-Shan; Guo, Ming Zhi; Cheeseman, C R; Tsang, Daniel C W; Donatello, Shane; Poon, Chi Sun

2018-02-01

Chemical extraction of phosphorus (P) from incinerated sewage sludge ash (ISSA) is adversely influenced by co-dissolution of metals and metalloids. This study investigated P recovery and leaching of Zn, Cu, Pb, As and Ni from ISSA using inorganic acids (sulphuric acid and nitric acid), organic acids (oxalic acid and citric acid), and chelating agents (ethylenediaminetetraacetic acid (EDTA) and ethylene diamine tetramethylene phosphonate (EDTMP)). The aim of this study was to optimize a leaching process to recover P-leachate with high purity for P fertilizer production. The results show that both organic and inorganic acids extract P-containing phases but organic acids leach more trace elements, particularly Cu, Zn, Pb and As. Sulphuric acid was the most efficient for P recovery and achieved 94% of total extraction under the optimal conditions, which were 2-h reaction with 0.2 mol/L H 2 SO 4 at a liquid-to-solid ratio of 20:1. EDTA extracted only 20% of the available P, but the leachates were contaminated with high levels of trace elements under optimum conditions (3-h reaction with EDTA at 0.02 mol/L, pH 2, and liquid-to-solid ratio of 20:1). Therefore, EDTA was considered an appropriate pre-treatment agent for reducing the total metal/metalloid content in ISSA, which produced negligible changes in the structure of ISSA and reduced contamination during subsequent P extraction using sulphuric acid. Copyright © 2017 Elsevier Ltd. All rights reserved.

Agglomeration of ash during combustion of peat and biomass in fluidized-bed reactors. Development of image analysis technique based on scanning electron microscopy; Tuhkan muuntuminen leijukerroskaasutuksessa ja -poltossa. Haitallisten hivenmetallien vapautuminen ja alkalien kaeyttaeytyminen

Energy Technology Data Exchange (ETDEWEB)

Kauppinen, E. [VTT Chemistry, Espoo (Finland); Arpiainen, V.; Jokiniemi, J. [VTT Energy, Espoo (Finland)] [and others

1996-12-01

The objective of the project is to study the behaviour of alkali metals (Na and K) and hazardous trace elements (Sb, As, Be, Cd, Cr, Co, Pb, Mn, Ni, Se and Zn) during fluidized bed combustion and gasification of solid fuels. The areas of interest are the release of elements studied from the bed and the behaviour of gaseous and particle-phase species after the release from the bed. During 1995 combustion and gasification experiments of Polish coal in bubbling bed were carried out with a laboratory scale fluidized bed gasifier in atmospheric pressure. Flue gas samples were drawn from the freeboard of the reactor and cooled quickly using a dilution probe. Ash particle size distributions were determined using low pressure impactors and differential mobility analyser. The morphology of the ash particles was studied with a scanning electron microscope (SEM) and will be further studied with transmission electron microscopy (TEM). The ash matrix elements (Si, Al, Fe, Ca and Mg) and the alkali metals (Na and K) were not significantly vaporized during the combustion process. More than 99 % of each of these elements was found in ash particles larger than 0.4 {mu}m. In Polish coal the alkali metals are bound mainly in silicates. The alkali metals were not released from the silicate minerals during the combustion process. A significant fraction of As, Cd and Pb was vaporized, released as gaseous species from the fuel particle and condensed mainly on the fine ash particles. 20 - 34 % of cadmium was present in fly ash particles smaller than 0.6 {mu}m (during combustion in 950 deg C), whereas only 1 % of the total ash was in this size fraction. All of the hazardous trace elements studied (As, Be, Cd, Co, Cr, Mn and Zn) were enriched in ash size fraction 0.6 - 5 {mu}m. The enrichment of Co, Cr, Mn, Ni, Pb and Sb was more significant during combustion in 950 deg C than in lower temperature (850 deg C)

Protecting black ash from the emerald ash borer

Science.gov (United States)

Les Benedict

2010-01-01

Black ash (Fraxinus nigra) is an important resource for Tribes in the Northeast and Great Lakes regions of the North American continent. Ash in North America is being threatened with widespread destruction as a result of the introduction of emerald ash borer beetle (Agrilus planipennis) in 2002. Measures are being taken to slow the spread of emerald ash borer beetle....

Trace elements in co-combustion of solid recovered fuel and coal

DEFF Research Database (Denmark)

Wu, Hao; Glarborg, Peter; Jappe Frandsen, Flemming

2013-01-01

Trace element partitioning in co-combustion of a bituminous coal and a solid recovered fuel (SRF) was studied in an entrained flow reactor. The experiments were carried out at conditions similar to pulverized coal combustion, with SRF shares of 7.9 wt.% (wet basis), 14.8 wt.% and 25.0 wt.......%. In addition, the effect of additives such as NaCl, PVC, ammonium sulphate, and kaolinite on trace element partitioning was investigated. The trace elements studied were As, Cd, Cr, Pb, Sb and Zn, since these elements were significantly enriched in SRF as compared to coal. During the experiments, bottom ash...... was collected in a chamber, large fly ash particles were collected by a cyclone with a cut-off diameter of ~2.5 μm, and the remaining fly ash particles were gathered in a filter. It was found that when coal was co-fired with SRF, the As, Cd, Pb, Sb and Zn content in filter ash/cyclone ash increased almost...

Synthesis of a one-part geopolymer system for soil stabilizer using fly ash and volcanic ash

Directory of Open Access Journals (Sweden)

Tigue April Anne S.

2018-01-01

Full Text Available A novel approach one-part geopolymer was employed to investigate the feasibility of enhancing the strength of in-situ soil for possible structural fill application in the construction industry. Geopolymer precursors such as fly ash and volcanic ash were utilized in this study for soil stabilization. The traditional geopolymer synthesis uses soluble alkali activators unlike in the case of ordinary Portland cement where only water is added to start the hydration process. This kind of synthesis is an impediment to geopolymer soil stabilizer commercial viability. Hence, solid alkali activators such as sodium silicate (SS, sodium hydroxide (SH, and sodium aluminate (SA were explored. The influence of amount of fly ash (15% and 25%, addition of volcanic ash (0% and 12.5%, and ratio of alkali activator SS:SH:SA (50:50:0, 33:33:33, 50:20:30 were investigated. Samples cured for 28 days were tested for unconfined compressive strength (UCS. To evaluate the durability, sample yielding highest UCS was subjected to sulfuric acid resistance test for 28 days. Analytical techniques such as X-ray fluorescence (XRF, X-ray diffraction (XRD, and scanning electron microscope/energy-dispersive X-ray spectroscopy (SEM/EDX were performed to examine the elemental composition, mineralogical properties, and microstructure of the precursors and the geopolymer stabilized soil.

Effect of Heat Treatment Temperature on Chemical Compositions of Extracted Hydroxyapatite from Bovine Bone Ash

Science.gov (United States)

Younesi, M.; Javadpour, S.; Bahrololoom, M. E.

2011-11-01

This article presents the effect of heat treating temperature on chemical composition of hydroxyapatite (HA) that was produced by burning bovine bone, and then heat treating the obtained bone ash at different temperatures in range of 600-1100 °C in air. Bone ash and the resulting white powder from heat treating were characterized by Fourier transformed infrared spectroscopy (FT-IR) and x-ray diffractometry (XRD). The FT-IR spectra confirmed that heat treating of bone ash at temperature of 800 °C removed the total of organic substances. x-ray diffraction analysis showed that the white powder was HA and HA was the only crystalline phase indicated in heat treating product. x-ray fluorescence analyses revealed that calcium and phosphorous were the main elements and magnesium and sodium were minor impurities of produced powder at 800 °C. The results of the energy dispersive x-ray analysis showed that Ca/P ratio in produced HA varies in range of 1.46-2.01. The resulting material was found to be thermally stable up to 1100 °C.

Long term effects of ash fertilization of reed canary grass; Laangtidseffekter av askgoedsling vid roerflensodling

Energy Technology Data Exchange (ETDEWEB)

Palmborg, Cecilia; Lindvall, Eva

2011-03-15

treatments 2008 were for Ca, where treatment A had higher concentrations and Mg where treatment A and B had higher concentrations than the control. Only treatment A had an increased pH compared to the control. This is probably because reed canary grass ash is rich in silica oxide which is acidic. [Table 2. Balance between supplied and removed amounts of nutritional elements and heavy metals during the experimental period. The removed amount per hectare has been calculated from the average between analyzes from 2004 and 2009, and dry matter yield per year. The only heavy metal content available for the fertilizers was Cd content in the phosphate.] [Table 3. pH-value and content of plant nutrients 2003 (per treatment) and 2008 (per plot) in topsoil and subsoil. Analysis of plant available nutrients by extraction with ammonium lactate.] In treatment A, the amounts of heavy metals applied greatly exceeded the limits for sewage sludge set by Swedish Environmental Protection Agency.

Separation and chemical characterization of finely-sized fly-ash particles

International Nuclear Information System (INIS)

Campbell, J.A.; Laul, J.C.; Nielson, K.K.; Smith, R.D.

1978-01-01

The concentrations of 43 major, minor, and trace elements were measured by x-ray fluorescence, atomic absorption, and instrumental neutron activation for nine well-defined size fractions, with mass median diameters of 0.5 μ to 50 μm, of fly ash from a western coal-fired steam plant. There was generally good agreement in concentrations of elements analyzed by more than one technique. Concentration profiles as a function of mean particle size were established for various elements. Based on the concentration profiles, the elements can be divided into three distinct groups. One group consists primarily of the volatile elements or elements partially volatilized during coal combustion (examples include As, Se, Zn, Ga, etc.), and their concentrations decrease with increasing particle size. A second group, which shows a minor or direct dependence on particle size, as in the case of Si, is apparently associated primarily with the fly-ash matrix. The last group of elements, which includes Ca, Sr, Y, and the rare earths, shows small changes in their concentration profiles with a maximum in concentration at approximately 5 μm. 6 tables, 6 figures

luminium alloy - rice husk ash composites production and analysis

Directory of Open Access Journals (Sweden)

Abdullahi Mohammed USMAN

2014-11-01

Full Text Available This study was carried out to produce and analyse the properties of Aluminium Alloy-Rice Husk Ash composites. Rice husk ash (RHA with high silica content of up to 97.095% was used for the study with the RHA varied from 0vol% – 30vol% at intervals of 5vol% in the aluminium alloy as reinforcement. The density and some mechanical properties of the composites including tensile strength, impact strength, hardness and fatigue strength were investigated. The results showed that the density of the composite decreases with the percentage increase of reinforcement from 2840.242 kgm-3 for the control sample to 2402.899 kgm-3 for 30vol% RHA. The Ultimate Tensile Strength (UTS varies from 164.374 MNm-2 at 0% RHA to 176.837 MNm-2 with maximum value at 10% RHA, impact strength values varies from 84.020kJm-2 at 0% RHA to 155.244 kJm-2 with maximum value at 10% RHA, hardness value varies from 70.467 RHV at 0% RHA to 109.367 RHV with maximum value at 25% RHA and fatigue strength varies from 0.224x106 cycles to 2.582x106 cycles with maximum cycle at 20% RHA. The results of analysis of variance showed that there are significant differences among the means of each property of the composites at different levels of replacement of the ash addition (P<0.05. It was concluded that the produced composites could be used to make engineering components such as automobile body parts, piston and block engine etc.

Microstructural characterization of ashes from Morinda citrifolia L. (Noni)

International Nuclear Information System (INIS)

Garay, Zoila; Acha De la Cruz, Otilia; Collantes, Ingrit; Olivera, Paula; Santiago, Julio; Universidad Nacional Mayor de San Marcos, Lima

2011-01-01

Noni, Morinda citrifolia Linnaeus, is widely used in traditional medicine due to its antibacterial, antiviral, antiparasitic and antifungal properties, preventing the proliferation of tumors and diabetes. This paper presents a study of the elemental and morphological composition of the ashes from the peels, seeds, pulp and leaves of the noni. These ashes are basically amorphous, except those from the annealing of the leaves. The main compounds that have been identified are the CaCO 3 (seeds and leaves), CaC 2 O 4 (peels and seeds), KHCO 3 (all samples except in leaves), KCl (leaves) and SiO 2 (leaves and pulp). Nanoparticles (20 nm) have been observed in all samples except in the ashes of leaves. (author).

Adsorption of As, B, Cr, Mo and Se from coal fly ash leachate by Fe3 modified bentonite clay

CSIR Research Space (South Africa)

Vhahangwele, M

2015-01-01

Full Text Available Fly ash contains the potentially toxic elements As, B, Cr, Mo and Se which upon contact with water may be leached to contaminate surface and subsurface water bodies. This study aims to evaluate the adsorption of these elements from coal fly ash...

Natural radioactivity of airbone particulates in coal-ash disposal sites

International Nuclear Information System (INIS)

Fukushima, Masanori; Tsukamoto, Masaki

1984-01-01

An investigation was made on the actual concentrations of U, Th and Po in air-borne dust and soil around coal power stations, to study the effect of coal-ash disposal site on natural radioactivity of environmental samples. Samples were collected at a coal-ash disposal and its reference places. The results obtained are summaried as follows; (1) Concentrations of U, Th and Po in air-borne dust at the disposal place was nealy equal to those at the reference place. (2) Origin of those α-emitting elements in the dust was successfully deduced, on the basis of correlating concentrations of Sc and Cl elements in the dust. (3) It was inferred that elements of both U and Po in the dust at disposal site came from soil by about 80% and artificial origin such as exhausted gas by remainder. Almost all Th element were from soil. It was therefore concluded that effect of disposal site on radioactivity concentrations of dusts was negligible. (author)

Isotope Dilution - Thermal Ionisation Mass Spectrometric Analysis for Tin in a Fly Ash Material

International Nuclear Information System (INIS)

Hernandez, C.; Fernandez, M.; Quejido, A. L.

2006-01-01

Isotope dilution-thermal ionisation mass spectrometry (ID-TIMS) analysis has been applied to the determination of tin in a fly ash sample supplied by the EC Joint Research Centre (Ispra, Italy). The proposed procedure includes the silica gel/phosphoric acid technique for tin thermal ionisation activation and a strict heating protocol for isotope ratio measurements. Instrumental mass discrimination factor has been previously determined measuring a natural tin standard solution. Spike solutions has been prepared from 112Sn-enriched metal and quantified by reverse isotope dilution analysis. Two sample aliquots were spiked and tin was extracted with 4,5 M HCI during 25 min ultrasound esposure time. Due to the complex matrix of this fly ash material, a two-steps purification stage using ion-exchange chromatography was required prior TIMS analysis. Obtained results for the two sample-spike blends (10,10 + - 0,55 y 10,50 + - 0,64 imolg-1) are comprarable, both value and uncertainty. Also a good reproducibility is observed between measurements. The proposed ID-TIMS procedure, as a primary method and due to the lack of fly ash reference material certified for tin content, can be used to validate more routine methodologies applied to tin determination in this kind of materials. (Author) 75 refs

The analysis of coal-and coke ashes by atomic absorption spectrophotometry

International Nuclear Information System (INIS)

Coutinho, C.A.; Prates, H.T.; Pereira, C.P.

1977-01-01

In order to provide better conditions for the control of the chemical composition of the load in the USIMINAS blast furnaces, a method of analysis for sodium, potassium, iron, aluminium, calcium, magnesium and maganese in coal-and coke ash by atomic absorption spectrophotometry was developed. The precision of the calibration curves and the reproducibility of the results are given, together with an estimate of the speed compared with conventional methods of chemical analysis [pt

Interlaboratory Comparison for Digestion Methods, Analytical Methods, and Holding Times for the Analysis of Trace Elements in Biological Samples for the Kingston Fly Ash Recovery Project

Energy Technology Data Exchange (ETDEWEB)

Mathews, Teresa J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rogers, William J [Tennessee Valley Authority (TVA), Knoxville, TN (United States); Vitale, Rock [Environmental Standards, Inc., Knoxville, TN (United States); Smith, John G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Brandt, Craig C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Peterson, Mark J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Carriker, Neil [Tennessee Valley Authority (TVA), Knoxville, TN (United States)

2013-05-01

In December 2008, an ash dike at the Tennessee Valley Authority (TVA) Kingston Fossil Plant (KIF) ruptured, releasing over 1 billion gallons of coal ash into the Emory and Clinch Rivers. Coal ash may contain several contaminants of concern; of these, selenium (Se), arsenic (As), and mercury (Hg) have been highlighted in this work because of their toxicity and potential to bioaccumulate in aquatic food chains (Reash et al. 2006, Chapman et al. 2010). To assess the potential impact of the spilled coal ash on humans and the environment, a comprehensive monitoring program was established at the Kingston site, for which resident aquatic organisms (among other sample media) are collected to determine contaminant exposure and evaluate the risk to humans and wildlife.

Determination of chromium in Bowen's kale, NBS bovine liver, and brewers yeast, before and after dry ashing

International Nuclear Information System (INIS)

Versieck, J.; Hoste, J.; De Rudder, J.; Barbier, F.; Vanballenberghe, L.

1979-01-01

In view of the persistent controversy about the volatility of chromium in biologic materials, the element was determined by neutron activation analysis in three reference materials before and after dry ashing up to 450 0 C. The following mean values were obtained: 0.364 μg/g and 0.362 μg/g (Bowen's kale), 0.0806 μg/g and 0.0789 μg/g (NBS bovine liver), 2.043 μg/g and 2.094 μg/g (NBS brewers yeast). It was concluded that chromium does not volatilize significantly in experimental conditions of drying and ashing

Volcanic ash and its enigma: A case study from the Central Indian Ocean Basin

Digital Repository Service at National Institute of Oceanography (India)

Pattan, J.N.

An ash layer occurs between 10-35 cm depth in sediment cores from the Central Indian Ocean basin. Morphology, major, trace and rare earth element composition of glass shards from the ash layer suggest that the Youngest Toba Tuff of ~74 ka from...

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

International Nuclear Information System (INIS)

Suslova, E.P.; Pertsikov, I.Z.

1991-01-01

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 (%): SiO 2 59.8; Al 2 O 3 ; Fe 23 O 3 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

Production of mineral ash-wool

International Nuclear Information System (INIS)

Micevic, Z.; Djekic, S.

1996-01-01

The project entitled 'Production of Mineral Ash-Wool' presents a new technology of possible use of the fly ash, generated as a waste product from the fossil fueled power plants, as a basic raw material for manufacturing of different products from a new mineral ash-wool. The wide area of mineral ash-wool application (civil engineering, industry, power generation, etc.) and the advantages of this new technology (important raw material obtained free of charge, substitution of expensive silicate stone, use of electric energy for melting instead for coke, vicinity of factory location close to the fossil fueled power plant, lower product price, reduction of environmental pollution, etc.) have resulted in the performance of the bench scale tests. Positive results have been obtained, as a good initial base for the realization of this project. The named study as an detailed analysis has been carried out for the assessment of: supply and sales market, analysis of possible and selection of an optimal location of the factory in the frame of fossil fueled power plant 'Kosovo', selection of the production capacity and alternative preliminary technical designs of the factory for the mineral ash-wool production. For the studied alternatives, specifications and capital investments evaluations for equipment and works (mechanical, civil engineering and electromechanical part) have been made as well as assessments of production costs. Based on the performed economical and financial analyses, as well as the sensitivity analyses one could be concluded that the investments in the factory for the mineral ash-wool production is highly economically acceptable. (author). 1 fig., 1 tab., 3 refs

Effects of gas conditions on ASH induced agglomeration

DEFF Research Database (Denmark)

Ma, T.; Fan, C. G.; Hao, L. F.

2016-01-01

Agglomeration is a serious problem for gasification and combustion of biomass in fluidized bed. Agglomeration characteristics may be affected by gas condition, but the literature is quite vague in this regard. This study focuses on the effects of gasification and combustion condition...... on agglomeration tendency with two types of biomass ash, including rice straw and wheat straw ash. The agglomerates are analyzed by SEM-EDS for morphology and elemental composition. Defluidization temperature (Td) in those two types of gas conditions is quite different. Tdin gasification condition is much lower...

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

Directory of Open Access Journals (Sweden)

MacLean Dan

2013-02-01

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

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.

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%. © The Author(s) 2016.

Ash in fire affected ecosystems

Science.gov (United States)

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

2015-04-01

the role of ash in fire affected areas. Acknowledgments The 'Litfire' Project (MIP-048/2011; 181 Pereira) funded by the Lithuanian Research Council, Soil quality, erosion control and plant cover recovery under different post-firemanagement scenarios (POSTFIRE), funded by the Spanish Ministry of Economy and Competitiveness (CGL2013-47862-C2-1-R), Preventing and Remediating Degradation of Soils in Europe Through Land Care (RECARE) funded by the European Commission (FP7-ENV-2013-TWO STAGE) and European Research Project LEDDRA (243857) and COST action ES1306 (Connecting European connectivity research). References Balfour, V.N., Determining wildfire ash saturated hydraulic conductivity and sorptivity with laboratory and field methods. Catena. doi:10.1016/j.catena.2014.01.009 Barreiro, A., Fontúrbel, M.T., Lombao, A., Martín, C., Vega, J.A., Fernández, C., Carballas, T., Díaz-Raviña, M., Using phospholipid fatty acid and community level physiological profiling techniques to characterize soil microbial communities following an experimental fire and different stabilization treatments. Catena. doi:10.1016/j.catena.2014.07.011 Bodi, M., Martin, D.A., Santin, C., Balfour, V., Doerr, S.H., Pereira, P., Cerda, A., Mataix-Solera, J. (2014) Wildland fire ash: production, composition and eco-hydro-geomorphic effects. Earth-Science Reviews, 130, 103-127. Bodí, M.B., Doerr, S.H., Cerdà, A. and Mataix-Solera, J. (2012) Hydrological effects of a layer of vegetation ash on underlying wettable and water repellent soils. Geoderma, 191, 14-23. Burjachs, F., Expósito, I., Charcoal and pollen analysis: examples of Holocene fire dynamics in Mediterranean Iberian Peninsula. Catena. doi:10.1016/j.catena.2014.10.006 Burns, K., Gabet, E., The effective viscosity of slurries laden with vegetative ash. Catena. doi:10.1016/j.catena.2014.06.008 Cerdà, A. Doerr, S.H. (2008). The effect of ash and needle cover on surface runoff and erosion in the immediate post-fire period. Catena, 74 , 256

In situ influence of coal ash dump on the quality of neighboring surface and ground waters by applying correlation statistic analysis

Energy Technology Data Exchange (ETDEWEB)

Jasna M. Djinovic; Aleksandar R. Popovic [University of Belgrade, Belgrade (Serbia and Montenegro). Center of Chemistry, Institute of Chemistry, Technology and Metallurgy

2007-01-15

The aim of this study was to establish the real in situ influence of coal ash and slag transport and storage on the quality of neighboring surface and ground waters by applying correlation statistic analysis. It was found that the waste waters from the coal ash dump do not have any influence on the quality of the Danube river water. The Danube and the waste waters, however, influence the quality of the ground waters of the Petka spring. Changes in the concentrations of elements in the Danube or in the waste waters can have immediate or delayed impact on the quality of the spring waters. The immediate impact has calcium, magnesium, zinc, copper, vanadium, cobalt from Danube; magnesium, vanadium from overflow and drainage waters; copper from drainage water. And the delayed impact has calcium, magnesium, vanadium and silicon from the Danube waters, cobalt from drainage waters, chromium and silicon from overflow waters and magnesium and vanadium from both overflow and drainage waters. 20 refs., 2 figs., 4 tabs.

Prediction of ash deposition using CFD simulation combined to thermodynamic calculation

Energy Technology Data Exchange (ETDEWEB)

Takeshi Muratani; Takashi Hongo [UBE Industries, Ltd., Yamaguchi (Japan). Coal Department, Energy and Environment Division

2007-07-01

This study focused on the advanced ash deposition prediction using computational fluid dynamics (CFD) analysis combined to thermodynamic calculation, considering both combustion characteristics and ash fusibility. Combustion field in pulverised coal-fired boiler was calculated through the normal CFD process. As the post process of combustion calculation, ash particles were injected into the combustion field to calculate ash deposition by CFD, in which particle sticking sub-program was newly employed. In this post process, ash deposition condition for CFD calculation was defined with the ash fusibility data obtained from thermodynamic analysis. These results of ash deposition on the furnace wall showed good agreement with the plant observation. Furthermore, in order to improve the plant operation, some virtual cases were simulated, which might reduce ash deposition. 7 refs., 14 figs., 6 tabs.

Mechanical properties and microstructure analysis of fly ash geopolymeric recycled concrete.

Science.gov (United States)

Shi, X S; Collins, F G; Zhao, X L; Wang, Q Y

2012-10-30

Six mixtures with different recycled aggregate (RA) replacement ratios of 0%, 50% and 100% were designed to manufacture recycled aggregate concrete (RAC) and alkali-activated fly ash geopolymeric recycled concrete (GRC). The physical and mechanical properties were investigated indicating different performances from each other. Optical microscopy under transmitted light and scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX) were carried out in this study in order to identify the mechanism underlying the effects of the geopolymer and RA on concrete properties. The features of aggregates, paste and interfacial transition zone (ITZ) were compared and discussed. Experimental results indicate that using alkali-activated fly ash geopolymer as replacement of ordinary Portland cement (OPC) effectively improved the compressive strength. With increasing of RA contents in both RAC and GRC, the compressive strength decreased gradually. The microstructure analysis shows that, on one hand, the presence of RA weakens the strength of the aggregates and the structure of ITZs; on the other hand, due to the alkali-activated fly ash in geopolymer concrete, the contents of Portlandite (Ca(OH)(2)) and voids were reduced, as well as improved the matrix homogeneity. The microstructure of GRC was changed by different reaction products, such as aluminosilicate gel. Copyright © 2012 Elsevier B.V. All rights reserved.

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

Energy Technology Data Exchange (ETDEWEB)

Allegrini, Elisa, E-mail: elia@env.dtu.dk [Technical University of Denmark, Department of Environmental Engineering, Building 115, 2800 Lyngby (Denmark); Maresca, Alberto; Olsson, Mikael Emil [Technical University of Denmark, Department of Environmental Engineering, Building 115, 2800 Lyngby (Denmark); Holtze, Maria Sommer [Afatek Ltd., Selinevej 18, 2300 Copenhagen S (Denmark); Boldrin, Alessio; Astrup, Thomas Fruergaard [Technical University of Denmark, Department of Environmental Engineering, Building 115, 2800 Lyngby (Denmark)

2014-09-15

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

Sample preparation techniques in trace element analysis by X-ray emission spectroscopy

International Nuclear Information System (INIS)

Valkovic, V.

1983-11-01

The report, written under a research contract with the IAEA, contains a detailed presentation of the most difficult problem encountered in the trace element analysis by methods of the X-ray emission spectroscopy, namely the sample preparation techniques. The following items are covered. Sampling - with specific consideration of aerosols, water, soil, biological materials, petroleum and its products, storage of samples and their handling. Pretreatment of samples - preconcentration, ashing, solvent extraction, ion exchange and electrodeposition. Sample preparations for PIXE - analysis - backings, target uniformity and homogeneity, effects of irradiation, internal standards and specific examples of preparation (aqueous, biological, blood serum and solid samples). Sample preparations for radioactive sources or tube excitation - with specific examples (water, liquid and solid samples, soil, geological, plants and tissue samples). Finally, the problem of standards and reference materials, as well as that of interlaboratory comparisons, is discussed

First experimental observations on melting and chemical modification of volcanic ash during lightning interaction.

Science.gov (United States)

Mueller, S P; Helo, C; Keller, F; Taddeucci, J; Castro, J M

2018-01-23

Electrification in volcanic ash plumes often leads to syn-eruptive lightning discharges. High temperatures in and around lightning plasma channels have the potential to chemically alter, re-melt, and possibly volatilize ash fragments in the eruption cloud. In this study, we experimentally simulate temperature conditions of volcanic lightning in the laboratory, and systematically investigate the effects of rapid melting on the morphology and chemical composition of ash. Samples of different size and composition are ejected towards an artificially generated electrical arc. Post-experiment ash morphologies include fully melted spheres, partially melted particles, agglomerates, and vesiculated particles. High-speed imaging reveals various processes occurring during the short lightning-ash interactions, such as particle melting and rounding, foaming, and explosive particle fragmentation. Chemical analyses of the flash-melted particles reveal considerable bulk loss of Cl, S, P and Na through thermal vaporization. Element distribution patterns suggest convection as a key process of element transport from the interior of the melt droplet to rim where volatiles are lost. Modeling the degree of sodium loss delivers maximum melt temperatures between 3290 and 3490 K. Our results imply that natural lighting strikes may be an important agent of syn-eruptive morphological and chemical processing of volcanic ash.

Micro and macrolevel properties of fly ash blended self compacting concrete

International Nuclear Information System (INIS)

Guru Jawahar, J.; Sashidhar, C.; Ramana Reddy, I.V.; Annie Peter, J.

2013-01-01

Highlights: ► Effect of class F fly ash on micro and macrolevel properties of self compacting concrete is studied. ► Decrease in microcracking width and Ca/Si ratio was observed in SCC with the age. ► Micro and macrolevels properties of SCC were compared to those of conventional concrete. ► Micro and macrolevel properties of SCC are reasonably correlated. ► Recommendation of SCC mix with medium compressive strength of 32 MPa for the building constructions. - Abstract: This investigation is mainly focused on the effect of class F fly ash on the micro and macrolevel properties of self compacting concrete (SCC) after 28, 56 and 112 days of curing. The microlevel properties studied were the microcrack widths between aggregate and paste and atomic Calcium–Silica (Ca/Si) ratio. The macrolevel properties studied were compressive strength, modulus of elasticity and splitting tensile strength. A conventional concrete (CC) having an equivalent 28-day SCC compressive strength has also been examined at different ages. Scanning electron microscope (SEM) analysis was carried to examine the width of microcracks and energy dispersive X-ray analysis (EDAX) was carried out to determine the chemical elements of both SCC and CC. Studies revealed that pozzolanic action of class F fly ash improved the microlevel properties of SCC with age by reducing the microcracking width and Ca/Si ratio and thus enhanced the macrolevel properties

Investigations of the technical possibilities for the use of fly ash: the concrete industry as a market. Marktbeschrijving betonwarenindustrie ten behoeve van het onderzoek naar de technische mogelijkheden van het gebruik van vliegas

Energy Technology Data Exchange (ETDEWEB)

1982-01-01

Desk research (analysis of the production figures of concrete) and field research (personal discussions with producers and merchants) are carried out to investigate whether the application of fly ash in the production of concrete is feasible. The introduction of fly ash depends on the properties of the final product and of the properties during the process of curing, and these depend on a large number of factors such as cement/sand ratio, quality of cement, specifications of the final product. Products such as paving stones, tiles and blocks are favourable for the application of fly ash in concrete. Building elements, pipes and floor elements are not. Market structure in The Netherlands is outlined and mapped, and the present use of fly ash in the concrete industry is discussed. (In Dutch)

Ash Utilisation 2012. Ashes in a Sustainable Society. Proceedings

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-11-01

Conference themes: Risk assessment, Fly ash- Road construction, Recycling and Greenhouse gases, Storage of ashes, Fertilizer, Metal Mining, Support and Barriers, Construction Material, Civil Engineering, and MSWI bottom ash.

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

Science.gov (United States)

Brook, Anna; Hamzi, Seham; Wittenberg, Lea

2015-04-01

S., Morag H., 2013. The effect of wildfires on vegetation cover and dune activity in Australia's desert dunes: a multisensor analysis International Journal of Wildland Fire, vol. 21 (4), pp. 459-475. Lugassi R., Ben-Dor E., Eshel G., 2013. Reflectance spectroscopy of soils post-heating'Assessing thermal alterations in soil minerals. Geoderma, vol. 231, pp. 268-279. Pereira P., Úbeda X., Martin D., Mataix-Solera J., Guerrero C. 2011. Effects of a low prescribed fire in ash water soluble elements in a Cork Oak (Quercus suber) forest located in Northeast of Iberian Peninsula, Environmental Research, vol. 111(2), pp. 237-247. Shakesby R.A., 2011. Post-wildfire soil erosion in the Mediterranean: Review and future research directions Earth Science Reviews, vol. 105, pp. 71-100. Woods, S.W., Balfour, V.N. 2010. The effects of soil texture and ash thickness on the post-fire hydrological response from ash-covered soils, Journal of Hydrology, vol. 393, pp. 274-286.

Natural weathering in dry disposed ash dump: Insight from chemical, mineralogical and geochemical analysis of fresh and unsaturated drilled cores.

Science.gov (United States)

Akinyemi, S A; Akinlua, A; Gitari, W M; Khuse, N; Eze, P; Akinyeye, R O; Petrik, L F

2012-07-15

Some existing alternative applications of coal fly ash such as cement manufacturing; road construction; landfill; and concrete and waste stabilisation use fresh ash directly collected from coal-fired power generating stations. Thus, if the rate of usage continues, the demand for fresh ash for various applications will exceed supply and use of weathered dry disposed ash will become necessary alternative. As a result it's imperative to understand the chemistry and pH behaviour of some metals inherent in dry disposed fly ash. The bulk chemical composition as determined by XRF analysis showed that SiO2, Al2O3 and Fe2O3 were the major oxides in fresh ash and unsaturated weathered ashes. The unsaturated weathered ashes are relatively depleted in CaO, Fe2O3, TiO2, SiO2, Na2O and P2O5 due to dissolution and hydrolysis caused by chemical interaction with ingressing CO2 from the atmosphere and infiltrating rain water. Observed accumulations of Fe2O3, TiO2, CaO, K2O, Na2O and SO3 and Zn, Zr, Sr, Pb, Ni, Cr and Co in the lower layers indicate progressive downward movement through the ash dump though at a slow rate. The bulk mineralogy of unsaturated weathered dry disposed ash, as determined by XRD analysis, revealed quartz and mullite as the major crystalline phases; while anorthite, hematite, enstatite, lime, calcite, and mica were present as minor mineral phases. Pore water chemistry revealed a low concentration of readily soluble metals in unsaturated weathered ashes in comparison with fresh ash, which shows high leachability. This suggests that over time the precipitation of transient minor secondary mineral phases; such as calcite and mica might retard residual metal release from unsaturated weathered ash. Chloride and sulphate species of the water soluble extracts of weathered ash are at equilibrium with Na+ and K+; these demonstrate progressive leaching over time and become supersaturated at the base of unsaturated weathered ash. This suggests that the ash dump does not

Long-term leaching of nutrients and contaminants from wood combustion ashes

DEFF Research Database (Denmark)

Maresca, Alberto; Hyks, J.; Astrup, Thomas Fruergaard

2018-01-01

With increasing amounts of woody biomass being combusted for energy purposes worldwide, more wood ash is being generated and needs management. As an alternative to landfilling, residues may be utilised for liming and fertilising purposes on forest soils. Comprehensive evaluations of long-term lea......With increasing amounts of woody biomass being combusted for energy purposes worldwide, more wood ash is being generated and needs management. As an alternative to landfilling, residues may be utilised for liming and fertilising purposes on forest soils. Comprehensive evaluations of long......-term leaching from these residues are needed in order to assess potential environmental impacts associated with their utilisation. Two Danish wood ash samples, one fly ash and one mixed ash (a combination of fly ash and bottom ash), were evaluated in long-term percolation column tests (up to L/S ∼2000 L....../kg), in order to quantify the release of major, minor and trace metal(loid)s. While columns of three different lengths were used, the leaching of individual elements could be described as a function of the L/S ratio – irrespective of the column length. At L/S 1000 L/kg, the cumulative releases of K, S, Na, Ca...

Application of spectroscopic techniques of analysis for the determination of trace elements concentrations in some sudanese food items

International Nuclear Information System (INIS)

Ahmed, A. N.; Ali, A.H.; Eltayeb, M. A.; Ahmed, M.M.O

2004-01-01

The objectives of this study were to determine the levels of the mineral nutrients, especially of trace elements, in some food items commonly consumed in sudan and to compare the results of this work with local and inter nation data. to achieve these objectives.Food samples were collected from different localities in sudan, and the samples were prepared for analysis using dry ashing and wet digestion. Atomic absorption spectroscopy (Aas), X-ray florescence spectroscopy (XRF), flame photometry and colorimetry were used for the determination of the concentrations of elements in the samples. Samples were ashed using muffle furnace at temperature 55 degree C. The quality of the data was verified by the analysis of standard reference materials TDD-Id and hay-9. The levels of the elemental contents (Br,Ca,Co,Cu,Fe,Mg,Mn,P,Pb,Na,Rb,Sr, and Zn) were determined in legumes, cereals, oil seeds, flour and cereal products, vegetables, fruits, milk and milk products, egg, meats and fish, and oils and fats. The sudanese food items analyzed were found to contain considerable ranges of nutrients as follows:-concentration levels for some of these elements Ca, Cu and Fe show values which were higher in fruits (4709,21, and 633 ppm, respectively), and lower in oils and fat s (25, 2, and 11 ppm, respectively). Pb and Mn were higher in flour and cereals products (4 and 34 ppm, respectively) and lower in fruits (1 ppm) and meats and fish (1 ppm and 4 ppm, respectively ). Na and Zn were higher in flour and cereals products and legumes (4970 and 39 ppm, respectively). The values obtained agree, in general, with data available from other countries. Variations were observed among certain varieties of food. (Author)

Mössbauer, XRD, and Complex Thermal Analysis of the Hydration of Cement with Fly Ash

Directory of Open Access Journals (Sweden)

Vili Lilkov

2013-01-01

Full Text Available Hydration of cement with and without fly ash is studied with Mössbauer spectroscopy, XRD, and thermal analysis. Iron in cement is present as Fe3+-ions and occupies two octahedral positions, with close isomer shifts and quadrupole splittings. Iron in fly ash is present as Fe2+ and Fe3+, and the Mössbauer spectra display three doublets—two for Fe3+ in octahedral coordination and one for Fe2+. A third doublet was registered in the hydrating plain cement pastes after the 5th day, due to Fe3+ in tetrahedral coordination in the structure of the newly formed monosulphate aluminate. In cement pastes with fly ash, the doublet of tetrahedral iron is formed earlier because the quantity of ettringite and portlandite is low and more monosulphate crystallizes. No Fe(OH3 phase forms during hydration of C4AF. The fly ash displays pozzolanic properties, which lead to lowering of the portlandite quantity in the cement mixtures and increasing of the high temperature products.

Yield and characteristics of shale oil from the retorting of oil shale and fine oil-shale ash mixtures

International Nuclear Information System (INIS)

Niu, Mengting; Wang, Sha; Han, Xiangxin; Jiang, Xiumin

2013-01-01

Highlights: • The whole formation process of shale oil might be divided into four stages. • Higher ash/shale mass ratio intensified the cracking and coking of shale oil. • Ash/shale ratio of 1:2 was recommended for oil shale fluidized bed retort with fine oil-shale ash as solid heat carrier. - Abstract: For exploring and optimizing the oil shale fluidized bed retort with fine oil-shale ash as a solid heat carrier, retorting experiments of oil shale and fine oil-shale ash mixtures were conducted in a lab-scale retorting reactor to investigate the effects of fine oil-shale ash on shale oil. Oil shale samples were obtained from Dachengzi Mine, China, and mixed with fine oil-shale ash in the ash/shale mass ratios of 0:1, 1:4, 1:2, 1:1, 2:1 and 4:1. The experimental retorting temperature was enhanced from room temperature to 520 °C and the average heating rate was 12 °C min −1 . It was found that, with the increase of the oil-shale ash fraction, the shale oil yield first increased and then decreased obviously, whereas the gas yield appeared conversely. Shale oil was analyzed for the elemental analysis, presenting its atomic H/C ratio of 1.78–1.87. Further, extraction and simulated distillation of shale oil were also conducted to explore the quality of shale oil. As a result, the ash/shale mixing mass ratio of 1:2 was recommended only for the consideration of increasing the yield and quality of shale oil

Analysis of cement solidified product and ash samples and preparation of a reference material

International Nuclear Information System (INIS)

Ishimori, Ken-ichiro; Haraga, Tomoko; Shimada, Asako; Kameo, Yutaka; Takahashi, Kuniaki

2010-08-01

Simple and rapid analytical methods for radionuclides in low-level radioactive waste have been developed by the present authors. The methods were applied to simulated solidified products and actual metal wastes to confirm their usefulness. The results were summarized as analytical guide lines. In the present work, cement solidified product and ash waste were analyzed followed by the analytical guide lines and subjects were picked up and solved for the application of the analytical guide lines to these wastes. Pulverization and homogenization method for ash waste was improved to prevent a contamination since the radioactivity concentrations of the ash samples were relatively high. Pre-treatment method was altered for the cement solidified product and ash samples taking account for their high concentration of Ca. Newly, an analytical method was also developed to measure 129 I with a dynamic reaction cell inductively coupled plasma mass spectrometer. In the analytical test based on the improved guide lines, gamma-ray emitting nuclides, 60 Co and 137 Cs, were measured to estimate the radioactivity of the other alpha and beta-ray emitting nuclides. The radionuclides assumed detectable, 3 H, 14 C, 36 Cl, 63 Ni, 90 Sr, and alpha-ray emitting nuclides, were analyzed with the improved analytical guide lines and their applicability for cement solidified product and ash samples were confirmed. Additionally a cement solidified product sample was evaluated in terms of the homogeneity and the radioactivity concentrations in order to prepare a reference material for radiochemical analysis. (author)

The potential of utilizing wood ash and peat ash on organic soils in Sweden; Arealer foer skogsgoedsling med traeaska och torvaska paa organogena jordar i Sverige

Energy Technology Data Exchange (ETDEWEB)

Haanell, Bjoern [Swedish Univ. of Agricultural Sciences, Umeaa (Sweden). Dept. of Silviculture

2004-01-01

Nutrients removed from the forest when branches and treetops are harvested as fuel can be returned to the site by recycling the remaining wood ash after combustion. This compensation measure is presently not carried out to any appreciable extent, partly because there is no economic incentive for the landowner. In sites where this measure has been applied, only on mineral soils (e.g. moraine) until now, greater margins for sustainable maintenance of the long-term site productivity can be expected. The ash contains all elements required for tree growth except for nitrogen (N). Therefore the ash amendment does not result in increased stand growth on these soils because the most important element for a growth response (N) is missing. In contrast, on organic soils N is often abundant whereas the amounts of other mineral nutrients are small. Thus, the elements lacking in the soils of peatland forests are available in the ash. This is especially true for phosphorus (P) and potassium (K). This means that peatland forests provide an opportunity for ash amendment in order to increase forest production. Old fertilization trials using wood ash show that the growth increase can be very large. The aim of this study was to (i) calculate the area of peat covered land that with respect to stand growth responses could be regarded as most suitable for bio-ash (wood ash and peat ash) fertilization, and (ii) assess the amount of bio-ash needed for fertilizing this area. Peat ash, although not as much studied, also has potential to be used to provide nutrients for increasing peatland forest growth. Most of the area calculations were based on data from the National Forest Inventory (NFI) 1997-2001. Sites were selected with guidance from existing knowledge about ash fertilization effects on tree growth and with the aid of registrations made in NFI regarding peat depth, site productivity, drainage, condition of drains, dominating field vegetation, and degree of stand development

Ash related behaviour in staged and non-staged combustion of biomass fuels and fuel mixtures

International Nuclear Information System (INIS)

Becidan, Michaël; Todorovic, Dusan; Skreiberg, Øyvind; Khalil, Roger A.; Backman, Rainer; Goile, Franziska; Skreiberg, Alexandra; Jovovic, Aleksandar; Sørum, Lars

2012-01-01

The fate of selected elements (with focus on the important players in corrosion i.e. Na, K, Pb, Zn, Cl and S) are investigated for three biomasses (wood, demolition wood and coffee waste) and six mixtures of these as pellets both with and without air staging in a laboratory reactor. In order to get a complete overview of the combustion products, both online and offline analytical methods are used. Information is collected about: flue gas composition, particle (fly ash) size distribution and composition, bottom ash composition and melting properties. The main findings are: (1) complex interactions are taking place between the mixed fuels during combustion; (2) the mode of occurrence of an element as well as the overall structure of the fuel are important for speciation; (3) the pelletisation process, by bringing chemical elements into intimate contact, may affect partitioning and speciation; (4) staging and mixing might simultaneously have positive and negative effects on operation; (5) staging affects the governing mechanisms of fly ash (aerosols) formation. -- Highlights: ► Complex interactions are taking place between the mixed fuels during combustion. ► The mode of occurrence of an element as well as the overall structure of the fuel are important for speciation. ► The pelletisation process, by bringing chemical elements into intimate contact, may affect partitioning and speciation. ► Staging and mixing might simultaneously have positive and negative effects on operation. ► Staging affects the governing mechanisms of fly ash (aerosols) formation.

Hospital waste ashes in Portland cement mortars

International Nuclear Information System (INIS)

Genazzini, C.; Zerbino, R.; Ronco, A.; Batic, O.; Giaccio, G.

2003-01-01

Nowadays, most concretes incorporate mineral additions such as pozzolans, fly ash, silica fume, blast furnace slag, and calcareous filler among others. Although the technological and economical benefits were the main reasons for the use of mineral additions, the prevention of environmental contamination by means of proper waste disposal becomes a priority. The chance of incorporating hospital waste ashes in Portland cement-based materials is presented here. Ash characterization was performed by chemical analysis, X-ray diffraction, radioactive material detection, and fineness and density tests. Conduction calorimetry and setting time tests were developed on pastes including ash contents from 0% to 100%. Mortars were prepared including ash contents up to 50% of cement. The results of setting time, temperature development, flexural and compressive strengths, water absorption, density, and leachability are analyzed. Results indicate that Portland cement systems could become an alternative for the disposal of this type of ashes

Quantification of fusion in ashes from solid fuel combustion

DEFF Research Database (Denmark)

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

1999-01-01

The fusion of ashes produced during solid fuel combustion greatly affects the tendency of these ashes to cause operational problems in utility boilers. In this paper, a new and quantitative laboratory method for assessing the fusion of ashes based on simultaneous thermal analysis, STA, is described...

Investigation on trace elements in crude oil and organic matter extracted from rocks with instrumental neutron activation analysis

International Nuclear Information System (INIS)

Ding Zuguo; Chai Zhifang

1990-01-01

Solvent extraction, column chromatography and instrumental neutron activation analysis(INAA) have been used to investigate the trace elements in crude oil, organic matter extracted from rocks and their related fractions. With these methods, about 70 crude oil samples from eight different oil fields in China and 6 extracted asphaltene samples of the lower paleozoic from the upper Yangtze region have been analyzed, and about 40 elements of interest have been determined. Those elements include Al, As, Au, Ba, Br, Cl, Co, Cr, Cs, Cu, Fe, Hf, I, Ir, Mg, Mn, Mo, Na, Ni, Rb, Re, S, Sb, Sc, Se, Sr, Th, Zn, V and parts of REE. The experimental results show that the method possesses several advantages, i.e. non-destructive, multi-elements, sensitive, precise and accurate. Without ashing samples, the loss of volatile elements such as Cl, S, Se and Sb are avoided. The column chromatography makes it possible to study the distributions of trace elements in different fractions of crude oil and organic matter extracted. Meanwhile, the characters of trace elements in them have also been discussed

Chromium behavior during thermal treatment of MSW fly ash.

Science.gov (United States)

Kirk, Donald W; Chan, Chris C Y; Marsh, Hilary

2002-02-14

Energy-from-waste incineration has been promoted as an environmentally responsible method for handling non-recyclable waste from households. Despite the benefits of energy production, elimination of organic residues and reduction of volume of waste to be landfilled, there is concern about fly ash disposal. Fly ash from an incinerator contains toxic species such as Pb, Zn, Cd and Cr which may leach into soil and ground water if landfilled. Thermal treatment of the fly ash from municipal solid waste has been tested and proposed as a treatment option for removal of metal species such as Pb, Cd and Zn, via thermal re-volatilization. However, Cr is an element that remains in the residue of the heat treated fly ash and appears to become more soluble. This Cr solubilization is of concern if it exceeds the regulatory limit for hazardous waste. Hence, this unexpected behavior of Cr was investigated. The initial work involved microscopic characterization of Cr in untreated and thermally-treated MSW fly ash. This was followed by determining leaching characteristics using standard protocol leaching tests and characterization leaching methods (sequential extraction). Finally, a mechanism explaining the increased solubilization was proposed and tested by reactions of synthetic chemicals.

An efficient and not polluting bottom ash extraction system

International Nuclear Information System (INIS)

Carrea, A.

1992-01-01

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

Microphysical Properties of Alaskan Volcanic Ash

Science.gov (United States)

Puthukkudy, A.; Espinosa, R.; Rocha Lima, A.; Remer, L.; Colarco, P. R.; Whelley, P.; Krotkov, N. A.; Young, K.; Dubovik, O.; Wallace, K.; Martins, J. V.

2017-12-01

Volcanic ash has the potential to cause a variety of severe problems for human health and the environment. Therefore, effective monitoring of the dispersion and fallout from volcanic ash clouds and characterization of the aerosol particle properties are essential. One way to acquire information from volcanic clouds is through satellite remote sensing: such images have greater coverage than ground-based observations and can present a "big picture" perspective. A challenge of remote sensing is that assumptions of certain properties of the target are often a pre-requisite for making accurate and quantitative retrievals. For example, detailed information about size distribution, sphericity, and optical properties of the constituent matter is needed or must be assumed. The same kind of information is also needed for atmospheric transport models to properly simulate the dispersion and fallout of volcanic ash. Presented here is a laboratory method to determine the microphysical and optical properties of volcanic ash samples collected from two Alaskan volcanoes with markedly different compositions. Our method uses a Polarized Imaging Nephelometer (PI-Neph) and a system that re-suspends the particles in an air flow. The PI-Neph measures angular light scattering and polarization of the re-suspended particles from 3o to 175o in scattering angle, with an angular resolution of 1o . Primary measurements include phase function and polarized phase function at three wavelengths (445nm, 532nm, and 661nm). Size distribution, sphericity, and complex refractive index are retrieved indirectly from the PI-Neph measurements using the GRASP (Generalized Retrieval of Aerosol and Surface Properties) inversion algorithm. We report the results of this method applied to samples from the Mt. Okmok (2008) and Mt. Katmai (1912) volcanic eruptions. To our knowledge, this is the first time direct measurements of phase matrix elements of ash from Mt. Okmok and Mt. Katmai have been reported. Retrieved

Ash fouling monitoring and key variables analysis for coal fired power plant boiler

Directory of Open Access Journals (Sweden)

Shi Yuanhao

2015-01-01

Full Text Available Ash deposition on heat transfer surfaces is still a significant problem in coal-fired power plant utility boilers. The effective ways to deal with this problem are accurate on-line monitoring of ash fouling and soot-blowing. In this paper, an online ash fouling monitoring model based on dynamic mass and energy balance method is developed and key variables analysis technique is introduced to study the internal behavior of soot-blowing system. In this process, artificial neural networks (ANN are used to optimize the boiler soot-blowing model and mean impact values method is utilized to determine a set of key variables. The validity of the models has been illustrated in a real case-study boiler, a 300MW Chinese power station. The results on same real plant data show that both models have good prediction accuracy, while the ANN model II has less input parameters. This work will be the basis of a future development in order to control and optimize the soot-blowing of the coal-fired power plant utility boilers.

Study on mechanical properties of fly ash impregnated glass fiber reinforced polymer composites using mixture design analysis

International Nuclear Information System (INIS)

Satheesh Raja, R.; Manisekar, K.; Manikandan, V.

2014-01-01

Highlights: • FRP with and without fly ash filler were prepared. • Mechanical properties of composites were analyzed. • Mixture Design Method was used to model the system. • Experimental and mathematical model results were compared. - Abstract: This paper describes the mechanical behavior of fly ash impregnated E-glass fiber reinforced polymer composite (GFRP). Initially the proportion of fiber and resin were optimized from the analysis of the mechanical properties of the GFRP. It is observed that the 30 wt% of E-glass in the GFRP without filler material yields better results. Then, based on the optimized value of resin content, the varying percentage of E-glass and fly ash was added to fabricate the hybrid composites. Results obtained in this study were mathematically evaluated using Mixture Design Method. Predictions show that 10 wt% addition of fly ash with fiber improves the mechanical properties of the composites. The fly ash impregnated GFRP yields significant improvement in mechanical strength compared to the GFRP without filler material. The surface morphologies of the fractured specimens were characterized using Scanning Electron Microscope (SEM). The chemical composition and surface morphology of the fly ash is analyzed by using Energy Dispersive Spectroscopy (EDS) and Scanning Electron Microscope

The use of coal fines fly ash for the improvement of soils in hydrophobic grounds

International Nuclear Information System (INIS)

Janssen-Mommen, J.P.M.; Bestebroer, S.I.

1992-01-01

New NO x reducing combustion techniques result in a different physical and morphological quality of fly ash, which makes the use of fly ash less attractive for the building and road construction industries. Attention is paid to the possibility of using low-NO x fly ash for the improvement of the properties of hydrophobic agricultural land. Such an application also depends on the environmental impacts of the leaching of elements to the ground water and the accumulation of hazardous compounds in crops. A literature study of hydrophobic grounds was carried out. Also attention is paid to the legal aspects. No juridical constraints could be found in the Dutch legislation concerning the use of fly ash from coal powder, although it seems that the use of such fly ash is not in agreement with the tenor of possibly to be applied legislation. However, a small-scale investigation was carried out to gain insight into the environmental impacts. The uptake in lettuce and the leaching of the elements As, B, Mo and Se was studied by means of lysimeters. Hydrophobic soils with 5%, 10% and 15% coal fines fly ash were used. Also an experiment with the use of coal gasification slags was performed

Particle dispersion at road building using fly ash - model review, investigation of influence of humidity content for dust emission and fly ash particle characterisation; Partikelspriding vid byggnation av vaeg med aska - modelloeversikt, undersoekning av fuktighetsgradens betydelse foer damning och karaktaerisering av partiklar fraan flygaska

Energy Technology Data Exchange (ETDEWEB)

Gustafsson, Mats; Wik, Ola; Frogner-Kockum, Paul

2009-03-15

at moisture contents above about 15%. The particle characterization study showed that ash specific chemical signal elements are preferred in the characterization. Important signal elements of ash can be S, Hg, Cd, and the ratio Mg/Al, but elements most appropriate might vary between specific types of ash and applications. The project has brought new knowledge about the possibilities to characterize ash particles and on the moisture needed to avoid dusting from ash. A method to try dusting from ash surfaces has been evaluated in laboratory and the project has also shown available, but in some respects inadequate, models for emission and dispersion of dust from handling of ash

Influence of Blended Cements with Calcareous Fly Ash on Chloride Ion Migration and Carbonation Resistance of Concrete for Durable Structures.

Science.gov (United States)

Glinicki, Michał A; Jóźwiak-Niedźwiedzka, Daria; Gibas, Karolina; Dąbrowski, Mariusz

2016-01-02

The objective of this paper is to examine the possible use of new blended cements containing calcareous fly ash in structural concrete, potentially adequate for structural elements of nuclear power plants. The investigation included five new cements made with different contents of non-clinker constituents: calcareous fly ash, siliceous fly ash, ground granulated blastfurnace slag, and a reference cement-ordinary Portland cement. The influence of innovative cements on the resistance of concrete to chloride and carbonation exposure was studied. Additionally, an evaluation of the microstructure was performed using optical microscopy on concrete thin sections. Test results revealed a substantial improvement of the resistance to chloride ion penetration into concrete containing blended cements. The resistance was higher for increased clinker replacement levels and increased with curing time. However, concrete made with blended cements exhibited higher depth of carbonation than the Portland cement concrete, except the Portland-fly ash cement with 14.3% of calcareous fly ash. The thin sections analysis confirmed the values of the carbonation depth obtained from the phenolphthalein test. Test results indicate the possible range of application for new cements containing calcareous fly ash.

Influence of Blended Cements with Calcareous Fly Ash on Chloride Ion Migration and Carbonation Resistance of Concrete for Durable Structures

Directory of Open Access Journals (Sweden)

Michał A. Glinicki

2016-01-01

Full Text Available The objective of this paper is to examine the possible use of new blended cements containing calcareous fly ash in structural concrete, potentially adequate for structural elements of nuclear power plants. The investigation included five new cements made with different contents of non-clinker constituents: calcareous fly ash, siliceous fly ash, ground granulated blastfurnace slag, and a reference cement—ordinary Portland cement. The influence of innovative cements on the resistance of concrete to chloride and carbonation exposure was studied. Additionally, an evaluation of the microstructure was performed using optical microscopy on concrete thin sections. Test results revealed a substantial improvement of the resistance to chloride ion penetration into concrete containing blended cements. The resistance was higher for increased clinker replacement levels and increased with curing time. However, concrete made with blended cements exhibited higher depth of carbonation than the Portland cement concrete, except the Portland-fly ash cement with 14.3% of calcareous fly ash. The thin sections analysis confirmed the values of the carbonation depth obtained from the phenolphthalein test. Test results indicate the possible range of application for new cements containing calcareous fly ash.

Chemometric analysis of alternations in coal ash quality induced by application of different mechano-chemical processing parameters

Directory of Open Access Journals (Sweden)

Terzić Anja

2017-01-01

Full Text Available The coal fly ash mechano-chemical activation conducted via high energy ultra-centrifugal mill was optimized using mathematical and statistical tools. The aim of the investigation was to accent the merits of alternations in ash processing schemes with a referral regarding the enhancement of the ash reactivity that will lead to its higher volume utilization as a cement replacement in concrete design. The impact of the processing parameters sets (number of rotor revolutions, current intensity, activation period, circumferential rotor speed, mill capacity on the on the product’s quality factors (grain size distribution, average grain size, micronization level, agglomeration tendency, specific surface area was assessed via Response surface method, Standard score analysis and Principal component analysis in order to obtain the most favorable output. Developed models were able to meticulously predict quality parameters in an extensive range of processing parameters. The calculated r2 values were in the range of 0.846-0.999. The optimal ash sample, that reached the Standard Score as high as 0.93, was produced using a set of processing parameters appropriate to experimental sequence with applied 120 μm sieve mesh. The microstructural characteristics were assessed using image-processing values and histogram plots of the activated fly ash SEM images. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. ON 172057, Grant no. III 45008, Grant no. TR 31055 and Grant no. TR 34006

Indirect effects of emerald ash borer-induced ash mortality and canopy gap formation on epigaeic beetles.

Science.gov (United States)

Gandhi, Kamal J K; Smith, Annemarie; Hartzler, Diane M; Herms, Daniel A

2014-06-01

Exotic herbivorous insects have drastically and irreversibly altered forest structure and composition of North American forests. For example, emerald ash borer (Agrilus planipennis Fairmaire) from Asia has caused wide-scale mortality of ash trees (Fraxinus spp.) in eastern United States and Canada. We studied the effects of forest changes resulting from emerald ash borer invasion on epigaeic or ground beetles (Coleoptera: Carabidae) along a gradient of ash dieback and gap sizes in southeastern Michigan. Ground beetles were sampled in hydric, mesic, and xeric habitats in which black (Fraxinus nigra Marshall), green (Fraxinus pennsylvanica Marshall), and white (Fraxinus americana L.) ash were the most common species, respectively. During 2006-2007, we trapped 2,545 adult ground beetles comprising 52 species. There was a negative correlation between percent ash tree mortality in 2006 and catches of all beetles. Catches of Agonum melanarium Dejean (in 2006) and Pterostichus mutus (Say) (in 2006-2007) were negatively correlated with tree mortality and gap size, respectively. However, catches of Pterostichus corvinus Dejean were positively correlated with gap size in 2006. As ash mortality and average gap size increased from 2006 to 2007, catches of all beetles as well as P. mutus and Pterostichus stygicus (Say) increased (1.3-3.9 times), while species diversity decreased, especially in mesic and xeric stands. Cluster analysis revealed that beetle assemblages in hydric and mesic stand diverged (25 and 40%, respectively) in their composition from 2006 to 2007, and that hydric stands had the most unique beetle assemblages. Overall, epigaeic beetle assemblages were altered in ash stands impacted by emerald ash borer; however, these impacts may dissipate as canopy gaps close.

Co-sintering of treated APC-residues with bottom ash

DEFF Research Database (Denmark)

Jensen, Dorthe Lærke; Bergfeldt, Britta; Vehlow, Jürgen

2001-01-01

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......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...... 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....

A critical review of nuclear activation techniques for the determination of trace elements in atmospheric aerosols, particulates and sludge samples

International Nuclear Information System (INIS)

Dams, R.

1992-01-01

Activation analysis is one of the major techniques for the determination of many minor and trace elements in a large variety of solid environmental and pollution samples, such as atmospheric aerosols, particulate emissions, fly ash, coal, incineration ash and sewage sludge, etc. Neutron activation analysis of total, inhalable or respirable airborne particulate matter collected on a filter or in a cascade impactor on some substrate, is very popular. By Instrumental Neutron Activation Analysis (INAA) up to 45 elements can be determined. The irradiation and counting procedures can be adapted to optimize the sensitivity for particular elements. The precision is largely governed by counting statistics and a high accuracy can be obtained after calibration with multi-elemental standards. Radiochemical Neutron Activation Analysis (RNAA) is applied only when extremely low limits of determination are required. Instrumental Photon Activation Analysis (IPAA) is complementary to INAA, since some elements of environmental interest can be determined which do not produce appropriate radionuclides by neutron irradiation. Charged Particle Activation Analysis (CPAA) is used in particular circumstances such as for certification purposes or coupled to radiochemical separations for extremely low concentrations. (author)

Comparison of lime and fly ash as amendments to acidic coal mine refusej growth responses and trace-element uptake of two grasses

Energy Technology Data Exchange (ETDEWEB)

Jasrow, J. D.; Zimmerman, C. A.; Dvorak, A. J.; Hinchman, R. R.

1979-10-01

Two commonly used revegetation species, Kentucky 31 tall fescue (Festuca arundinacea Schreb.) and Lincoln smooth brome (Bromus inermis Leyss.) were grown for 60 days in pots containing coarse coal mine refuse (referred to as gob, pH = 3.5) that was amended with lime or alkaline fly ash. Both species were also grown in pots containing a silt-loam surface soil as a control. Morphological growth parameters were measured over time; dry weights and shoot:root ratios were determined at harvest. Concentrations of Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, V, and Zn in the plant shoots were determined by atomic absorption spectrophotometry. Plant growth of both species was not as good on either lime- or fly ash-amended gob as it was on surface soil. Although plant height and length of the longest lead were not significantly different (p > 0.10) at the end of the experiment for plants grown on the two amended-gob substrates, parameters giving an indication of plant vigor (i.e., number of leaves and stems, width of the longest lead, and biomass) were significantly greater (p < 0.01) for plants grown on lime-amended gob than for those grown on fly ash-amended gob. Significant (p < 0.05) differences in the tissue concentrations of Cd, Co, Fe, Hg, Mn, Pb, V, and Zn were found among the plants grown on the three substrates. Except for Hg and Pb, these elements were higher in plants grown on at least one of the amended-gob substrates than in plants grown on surface soil. Significant substrate differences were not observed for Al, As, Cr, Cu, Ni, and Se. The tissue concentrations of some elements - notably Al, Cu, Fe, Mn, V, and Zn - were high enough in plants from one or more of the substrates to either approach or exceed concentrations that have been reported to be associated with toxic effects in some plant species.

A new quantification method based on SEM-EDS to assess fly ash composition and study the reaction of its individual components in hydrating cement paste

Energy Technology Data Exchange (ETDEWEB)

Durdziński, Paweł T., E-mail: pawel.durdzinski@gmail.com [Laboratory of Construction Materials, École Polytechnique Fédérale de Lausanne (EPFL), Station 12, CH-1015 Lausanne (Switzerland); Dunant, Cyrille F. [Laboratory of Construction Materials, École Polytechnique Fédérale de Lausanne (EPFL), Station 12, CH-1015 Lausanne (Switzerland); Haha, Mohsen Ben [HeidelbergCement Technology Center GmbH (HeidelbergCement AG), Rohrbacher Str. 95, 69181 Leimen (Germany); Scrivener, Karen L. [Laboratory of Construction Materials, École Polytechnique Fédérale de Lausanne (EPFL), Station 12, CH-1015 Lausanne (Switzerland)

2015-07-15

Calcareous fly ashes are high-potential reactive residues for blended cements, but their qualification and use in concrete are hindered by heterogeneity and variability. Current characterization often fails to identify the dominant, most reactive, amorphous fraction of the ashes. We developed an approach to characterize ashes using electron microscopy. EDS element composition of millions of points is plotted in a ternary frequency plot. A visual analysis reveals number and ranges of chemical composition of populations: silicate, calcium-silicate, aluminosilicate, and calcium-rich aluminosilicate. We quantified these populations in four ashes and followed their hydration in two Portland-ash systems. One ash reacted at a moderate rate: it was composed of 70 vol.% of aluminosilicates and calcium-silicates and reached 60% reaction at 90 days. The other reacted faster, reaching 60% at 28 days due to 55 vol.% of calcium-rich aluminosilicates, but further reaction was slower and 15 vol.% of phases, the silica-rich ones, did not react.

A new quantification method based on SEM-EDS to assess fly ash composition and study the reaction of its individual components in hydrating cement paste

International Nuclear Information System (INIS)

Durdziński, Paweł T.; Dunant, Cyrille F.; Haha, Mohsen Ben; Scrivener, Karen L.

2015-01-01

Calcareous fly ashes are high-potential reactive residues for blended cements, but their qualification and use in concrete are hindered by heterogeneity and variability. Current characterization often fails to identify the dominant, most reactive, amorphous fraction of the ashes. We developed an approach to characterize ashes using electron microscopy. EDS element composition of millions of points is plotted in a ternary frequency plot. A visual analysis reveals number and ranges of chemical composition of populations: silicate, calcium-silicate, aluminosilicate, and calcium-rich aluminosilicate. We quantified these populations in four ashes and followed their hydration in two Portland-ash systems. One ash reacted at a moderate rate: it was composed of 70 vol.% of aluminosilicates and calcium-silicates and reached 60% reaction at 90 days. The other reacted faster, reaching 60% at 28 days due to 55 vol.% of calcium-rich aluminosilicates, but further reaction was slower and 15 vol.% of phases, the silica-rich ones, did not react

PENENTUAN KOMPOSISI KIMIA ABU VULKANIK DARI ERUPSI GUNUNG MERAPI (Determination of Chemical Composition of Volcanic Ash from Merapi Mt. Eruption

Directory of Open Access Journals (Sweden)

Endang Tri Wahyuni

2012-07-01

 In order to identify the utilizing potential and the environmental effect of ash from Merapi Mount eruption in 2010, determination of its chemical composition has been performed, including major, minor and trace elements. In addition,  pH of the ash, and iron concentration in rivers, wells, and  tower for water collection were also determined. The ash samples was taken in December 2010- January 2011, after the eruption stopped, located in Magelang, Sleman, and Klaten regions, in various distances from the summit.The results of the determination show that the Merapi Mt. ash contains major (Al, Si, Ca, and  Fe, minor (K, Mg, Mn, Na, P, S, and Ti, and  trace elements (Au ,As, Ba, Co, Cr, Cu, Mo, Ni, Pb, S, Sb, Sn, Sr, V, Zn, dan Zr.   The elements can be categorized into  widely used elements, i.e.   Al, Si, Ca, Fe, Ti, V, and  Zn, and economic high value element,  i.e.  Au, as well as  the environment and health negative affect elements  such as As, Cr, Cr, Cu, Pb, Ni, and S. It is also found that the  ash taken from different locations with farther distances from the mountain, has similar chemical composition.  Moreover, based on the large content of Al, Ca, and  Si  (around 56%, 4%, and  18 %respectively,  enabling the ash to be used as raw material for  cement or other cement based materials production. In addition, since Ti and Fe is also found in adequate level in the ash, it is also possible to extract the metals to get the pure one having wide and valuable functions. The presence of K and P, as fertilizer components, in the ash with significant amount, it is also interesting to evaluate the effect of the ash covering the soil on its fertile. However, the low pH of the ash is also observed that is due  to the presence of S in considerable amount, leading to the soil becomes unfertile. Although the hazard heavy (Pb, Cd, Cr, Cu, and Ni are found in the ash, the contamination of the metals in the rivers and wells are not detected

Geopolymerisation of fly ashes with waste aluminium anodising etching solutions.

Science.gov (United States)

Ogundiran, M B; Nugteren, H W; Witkamp, G J

2016-10-01

Combined management of coal combustion fly ash and waste aluminium anodising etching solutions using geopolymerisation presents economic and environmental benefits. The possibility of using waste aluminium anodising etching solution (AES) as activator to produce fly ash geopolymers in place of the commonly used silicate solutions was explored in this study. Geopolymerisation capacities of five European fly ashes with AES and the leaching of elements from their corresponding geopolymers were studied. Conventional commercial potassium silicate activator-based geopolymers were used as a reference. The geopolymers produced were subjected to physical, mechanical and leaching tests. The leaching of elements was tested on 28 days cured and crushed geopolymers using NEN 12457-4, NEN 7375, SPLP and TCLP leaching tests. After 28 days ambient curing, the geopolymers based on the etching solution activator showed compressive strength values between 51 and 84 MPa, whereas the commercial potassium silicate based geopolymers gave compressive strength values between 89 and 115 MPa. Based on the regulatory limits currently associated with the used leaching tests, all except one of the produced geopolymers (with above threshold leaching of As and Se) passed the recommended limits. The AES-geopolymer geopolymers demonstrated excellent compressive strength, although less than geopolymers made from commercial activator. Additionally, they demonstrated low element leaching potentials and therefore can be suitable for use in construction works. Copyright © 2016. Published by Elsevier Ltd.

Characteristics of biomass ashes from different materials and their ameliorative effects on acid soils.

Science.gov (United States)

Shi, Renyong; Li, Jiuyu; Jiang, Jun; Mehmood, Khalid; Liu, Yuan; Xu, Renkou; Qian, Wei

2017-05-01

The chemical characteristics, element contents, mineral compositions, and the ameliorative effects on acid soils of five biomass ashes from different materials were analyzed. The chemical properties of the ashes varied depending on the source biomass material. An increase in the concrete shuttering contents in the biomass materials led to higher alkalinity, and higher Ca and Mg levels in biomass ashes, which made them particularly good at ameliorating effects on soil acidity. However, heavy metal contents, such as Cr, Cu, and Zn in the ashes, were relatively high. The incorporation of all ashes increased soil pH, exchangeable base cations, and available phosphorus, but decreased soil exchangeable acidity. The application of the ashes from biomass materials with a high concrete shuttering content increased the soil available heavy metal contents. Therefore, the biomass ashes from wood and crop residues with low concrete contents were the better acid soil amendments. Copyright © 2016. Published by Elsevier B.V.

Development of novel ash hybrids to introgress resistance to emerald ash borer into north American ash species

Science.gov (United States)

Jennifer L. Koch; David W. Carey; Mary E. Mason

2008-01-01

Currently, there is no evidence that any of the native North American ash species have any resistance to the emerald ash borer (EAB). This means that the entire ash resource of the eastern United States and Canada is at risk of loss due to EAB. In contrast, outbreaks of EAB in Asian ash species are rare and appear to be isolated responses to stress (Bauer et al. 2005,...

Arsenic and mercury partitioning in fly ash at a Kentucky power plant

Energy Technology Data Exchange (ETDEWEB)

Tanaporn Sakulpitakphon; James C. Hower; Alan S. Trimble; William H. Schram; Gerald A. Thomas [University of Kentucky, Lexington, KY (United States). Center for Applied Energy Research

2003-08-01

Coal and fly ash samples were collected from a 500-MW unit at a Kentucky power plant, with the objective of studying the distribution of arsenic, mercury, and other trace elements in fly ash. The coal feed was low-sulfur, high volatile A bituminous central West Virginia coal. The plant produced a relatively low-carbon fly ash. In contrast to power plants with high-mercury feed coal, the fly ashes from the lower-mercury feed coal had low mercury values, generally not exceeding 0.01 ppm Hg. Mercury capture by fly ash varies with both the amount and type of carbon and the collection temperature; mercury capture is more efficient at lower temperatures. Arsenic in the feed coal and in the flue gas is of concern to the utility, because of the potential for catalyst poisoning in the selective catalytic reduction system (in the planning stage at the time of the sampling). Arsenic is captured in the fly ash, increasing in concentration in the more-distant (from the boiler) reaches of the electrostatic precipitator system. 16 refs., 2 figs., 5 tabs.

The analysis of mechanical properties of non autoclaved aerated concrete with the substitution of fly ash and bottom ash

Science.gov (United States)

Karolina, R.; Muhammad, F.

2018-02-01

Based on PP. No.85 of 1999 on the management of hazardous and toxic (B3), fly ash and bottom ash wastes are categorized into B3 waste because there are heavy metal oxide contents that can pollute the environment. One form of environmental rescue that can be applied is to utilize waste fly ash and bottom ash in the manufacture of concrete. In this research, fly ash and bottom ash waste are used as substitution of cement and fine aggregate to make lightweight concrete. The purpose of this research is to know the mechanical properties of non-autoclaved aerated lightweight concrete (NAAC) with FA and BA substitution to cement and fine aggregate which is expected to improve the quality of concrete. The NAAC lightweight concrete in this study is divided into 4 categories: normal NAAC lightweight concrete, NAAC lightweight NAAC substituted concrete with FA, NAAC lightweight concrete substituted with BA, and NAAC combined light weight from FA and BA with variations of 10%, 20% And 30%. The test specimen used in cylindrical shape, which was tested at the age of 28 days, amounted to 90 pieces and consisted of 10 variations. Each variation amounted to 9 samples. Based on the test results with FA and BA substitutions of 10%, 20%, and 30%, the highest compressive strength was achieved in samples with FA 30% of 12.687 MPa, maximum tensile strength achieved in samples with FA 30% of 1,540 MPa, The highest absorption was achieved in normal NAAC of 5.66%. Based on the weight of the contents of all samples, samples can be categorized in lightweight concrete, since the weight of the contents is less than 1900 kg / m3.

Silica from Ash

Indian Academy of Sciences (India)

management, polymer composites and chemical process design. Figure 1 Difference in color of the ash ... The selection of ash is important as the quality of ash determines the total amount as well as quality of silica recoverable Ash which has undergone maximum extent of combustion is highly desirable as it contains ...

A technique for mapping urban ash trees using object-based image analysis

Science.gov (United States)

Dacia M. Meneguzzo; Susan J. Crocker; Greg C. Liknes

2010-01-01

Ash trees are an important resource in the State of Minnesota and a common fixture lining the streets of the Twin Cities metropolitan area. In 2009, the emerald ash borer (EAB), an invasive pest of ash, was discovered in the city of St. Paul. To properly respond to the new-found threat, decisionmakers would benefit from detailed, spatially explicit information on the...

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

About 85% of the ashes produced in Sweden originated from the incineration of municipal solid waste and biofuel. The rest comes from the thermal treatment of recycled wood, peat, charcoal and others. About 68% of all ashes annually produced in Sweden are used for constructions on landfills, mainly slopes, roads and embankments, and only 3% for construction of roads and working surfaces outside the landfills (SCB, 2013). Since waste bottom ash (BA) often has similar properties to crushed bedrock or gravel, it could be used for road constructions to a larger extent. However, the leaching of e.g. Cr, Cu, Mo, Pb and Zn can cause a threat to the surrounding environment if the material is used as it is. Carbonation is a commonly used pre-treatment method, yet it is not always sufficient. As leaching from aged ash is often controlled by adsorption to iron oxides, increasing the number of Fe oxide sorption sites can be a way to control the leaching of several critical elements. The importance of iron oxides as sorption sites for metals is known from both mineralogical studies of bottom ash and from the remediation of contaminated soil, where iron is used as an amendment. In this study, zero valent iron (Fe(0)) was added prior to accelerated carbonation in order to increase the number of adsorption sites for metals and thereby reduce leaching. Batch, column and pHstat leaching tests were performed and the leaching behaviour was evaluated with multivariate data analysis. It showed that leaching changed distinctly after the tested treatments, in particular after the combined treatment. Especially, the leaching of Cr and Cu clearly decreased as a result of accelerated carbonation. The combination of accelerated carbonation with Fe(0) addition reduced the leaching of Cr and Cu even further and reduced also the leaching of Mo, Zn, Pb and Cd compared to untreated BA. Compared with only accelerated carbonation, the Fe(0) addition significantly reduced the leaching of Cr, Cu and Mo

Chemistry of the direct acid leach, calsinter, and pressure digestion-acid leach methods for the recovery of alumina from fly ash

Energy Technology Data Exchange (ETDEWEB)

Kelmers, A.D.; Canon, R.M.; Egan, B.Z.; Felker, L.K.; Gilliam, T.M.; Jones, G.; Owen, G.D.; Seeley, F.G.; Watson, J.S.

1982-08-01

The chemistry of three methods for the recovery of alumina from fly ash is reviewed. Fly ashes are characterized with respect to both physical and chemical properties, and differences in ashes derived from eastern and western coals are identified. Aluminum solubilization from fly ashes is explained in terms of the solid phases present, which are related to the basic element content of the ash. The methods used yield high aluminum solubilization from both eastern and western fly ashes. (9 refs.)

Plant nutrition on fly-ash

Energy Technology Data Exchange (ETDEWEB)

Rees, W J; Sidrak, G H

1956-12-01

Experiments were performed to determine the plant nutritional potential of fly ash. Chemical analysis indicates that it contains all the essential nutrients. It is deficient in nitrogen and only manganese and aluminum appear to be available in quantities toxic to plants. Barley and spinach grown on fly ash accumulate excessive quantities of Al and Mn in their leaves and exhibit symptoms of toxicities of these metals. Atriplex hastata grows vigorously on the ash, has a high Al and Mn leaf content, but does not show toxicity symptoms. Atriplex, barley and spinach grown at reduced N levels gave lower yields than the normal controls, but symptoms of N deficiency which were evident in barley and spinach were not observed in Atriplex. 17 references, 2 figures, 14 tables.

Disposal of low-level radioactive waste using high-calcium fly ash. Final report

International Nuclear Information System (INIS)

Cogburn, C.O.; Hodgson, L.M.; Ragland, R.C.

1986-04-01

The feasibility of using calcium-rich fly ash from coal-fired power plants in the disposal of low-level radioactive waste was examined. The proposed areas of use were: (1) fly-ash cement as a trench lining material; (2) fly ash as a backfill material; and (3) fly ash as a liquid waste solidifier. The physical properties of fly-ash cement were determined to be adequate for trench liner construction, with compressive strengths attaining greater than 3000 psi. Hydraulic conductivities were determined to be less than that for clay mineral deposits, and were on the order of 10 -7 cm/sec, with some observed values as low as 10 -9 cm/sec. Removal of radioisotopes from acidified solutions by fly ash was good for all elements tested except cesium. The removal of cesium by fly ash was similar to that of montmorillonite clay. The corrosive effects on metals in fly ash environments was determined to be slight, if not non-existent. Coatings at the fly-ash/metal interfaces were observed which appeared to inhibit or diminish corrosion. The study has indicated that high-calcium fly ash appears to offer considerable potential for improved retention of low-level radioactive wastes in shallow land disposal sites. Further tests are needed to determine optimum methods of use. 8 refs., 4 figs., 7 tabs

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.

Wood ash as a soil additive and liming agent

International Nuclear Information System (INIS)

Campbell, A.; Etiegni, L.; Mahler, R.L.

1991-01-01

This study evaluated wood ash as an agricultural soil supplement and liming material. Winter wheat (Triticum aestivum) and poplar (Populus sp.) were grown in a greenhouse on six different Idaho soils amended with different ash concentrations. At ash levels equal to or lower than 2%, no detrimental effects were observed. In fact, the biomass of the wheat and the caliper and height of the poplar cuttings increased more at 2% ash 940 metric tons/ha than with the control soil. These results suggest that wood ash could be used in agricultural applications as a low analysis fertilizer containing potassium and as a liming agent. Land application of wood ash could be less expensive and more environmentally sound than present landfilling practices

Tephra stratification of volcanic ash soils in Nothern Ecuador

NARCIS (Netherlands)

Tonneijck, F.H.; Hageman, J.A.; Sevink, J.; Verstraten, J.M.

2008-01-01

We combined proxies traditionally used in stratigraphic research (mineral assemblages, grain size distribution, and element ratios) with soil organic carbon contents and radiocarbon dating both at a high vertical resolution, to unravel the tephra stratigraphy in volcanic ash soils. Our results show

Characterization of the ashes from the 2014-2015 Turrialba Volcano eruptions by means of scanning electron microscopy and energy dispersive X-Ray spectroscopy

International Nuclear Information System (INIS)

Lucke, Oscar H.; Calderon, Ariadna

2016-01-01

The Turrialba Volcano is a stratovolcano located approximately 35 km northwest from San Jose, Costa Rica's capital city. A series of eruptions since October 29, 2014 until at least late 2015, has represented the most significant activity of this volcano since the 1860s. A significant volume of ash was dispersed with this eruptions that reached the most populous areas of the country. The characteristics of the ash particles are analyzed in order to establish the nature of the eruptive events that occurred on 2014 and 2015, and to monitor the evolution of the eruptive processes. The analysis was carried out utilizing optical microscopy and stereomicroscopy techniques, as well as novel scanning electron microscopy (SEM) methods that involve imaging and element composition analysis by means of Energy Dispersive X-Ray Spectroscopy (EDX). The evolution of the Turrialba eruptions is showed from phreatic events in 2014, with ashes composed entirely of non-juvenile fragments, to phreatomagmatic events starting on March 12, 2015 with the appearance of a significant fraction of juvenile components in the ash. (author)

Utilization of coal fly ash in solidification of liquid radioactive waste from research reactor.

Science.gov (United States)

Osmanlioglu, Ahmet Erdal

2014-05-01

In this study, the potential utilization of fly ash was investigated as an additive in solidification process of radioactive waste sludge from research reactor. Coal formations include various percentages of natural radioactive elements; therefore, coal fly ash includes various levels of radioactivity. For this reason, fly ashes have to be evaluated for potential environmental implications in case of further usage in any construction material. But for use in solidification of radioactive sludge, the radiological effects of fly ash are in the range of radioactive waste management limits. The results show that fly ash has a strong fixing capacity for radioactive isotopes. Specimens with addition of 5-15% fly ash to concrete was observed to be sufficient to achieve the target compressive strength of 20 MPa required for near-surface disposal. An optimum mixture comprising 15% fly ash, 35% cement, and 50% radioactive waste sludge could provide the solidification required for long-term storage and disposal. The codisposal of radioactive fly ash with radioactive sludge by solidification decreases the usage of cement in solidification process. By this method, radioactive fly ash can become a valuable additive instead of industrial waste. This study supports the utilization of fly ash in industry and the solidification of radioactive waste in the nuclear industry.

Application of washed MSWI fly ash in cement composites: long-term environmental impacts.

Science.gov (United States)

Yang, Zhenzhou; Tian, Sicong; Liu, Lili; Wang, Xidong; Zhang, Zuotai

2018-04-01

In the present study, long-term environmental impacts of compact and ground cement composites, in which 30 wt.% of cement was replaced by washed municipal solid wastes incineration (MSWI) fly ash, were investigated for use in building industry. Consecutive leaching tests over a time span of 180 days were performed in acid water, deionized water, and saline water, respectively, with the accumulative concentration of different elements determined in the leachate. Different leaching behaviors are observed among different potential toxic elements (PTEs). For instance, higher concentrations of V in the leachate were observed from the compact cement composites than those from the ground ones. The concentration of Ba in the leachate increased with the decrease of particle size of the cement composites, and an initial increase in the leaching efficiency of Sn was followed by a clear decline with the leaching time. In addition, kinetic study revealed that the leaching behaviors of potential toxic elements follow a second-order model. The results demonstrated that the addition of washed MSWI fly ash into cement can contribute to the attrition resistance, indicating that the washed MSWI fly ash could be a promising alternative for cement as supplementary building materials.

Partitioning of elements during coal combustion and leaching experiments

Energy Technology Data Exchange (ETDEWEB)

Wang Wen-feng; Qin Yong; Song Dang-yu; Wang Jun-yi [China University of Mining & Technology, Xuzhou (China). School of Resources and Earth Science

2009-04-15

The mineral component and content of sulfur and 42 major and trace elements of the feed coal, fly and bottom ashes collected from Shizuishan coal-fired power plant, Ningxia, China were analyzed using AFS, INAA, ICP-MS, ICP-AES, XRD. Based on the coal combustion and leaching experiments, the partitioning of these elements during coal combustion and the leaching behavior of the 11 potentially hazardous elements, including As, Cd, Co, Cr, Hg, Mo, Ni, Pb, Se, Th and U were investigated. The results show that the distribution of elements in the fly and bottom ashes is controlled by their volatilities and modes of occurrence in the coal. The degree of volatilization of elements may be mainly associated with boiling/melting points of these elements and their compounds. The elements easily volatilized, organically bound or associated with sub-micrometer and nano minerals (e.g. Al and Na) tend to be enriched in the fine fractions of fly ash, and most elements do not vaporize which are approximately equally partitioned in the fly and bottom ashes. The emission rates of As, Cr, K, Mg, Mn, Mo, Pb, Sb, and Zn are notably influenced by the temperature ranging from 877 to 1300{sup o}C. The leaching behavior of elements depend significantly on their geochemical properties and modes of occurrence. The elements with a low degree of volatilization are not easily leached, while volatile elements easily leached under the acid conditions. Arsenic, B Br, Cd, Cu, Hg, Pb, S, Sb and Se show a higher emission rate during coal combustion, and the leached concentrations of Cd, Co, Mo, Ni and U in the acid media exceed their limited concentrations recommended in relevant environment quality standards for water, which will harm the environment. 32 refs., 4 figs., 4 tabs.

Volcanic ash leaching as a means of tracing the environmental impact of the 2011 Grímsvötn eruption, Iceland.

Science.gov (United States)

Cabré, J; Aulinas, M; Rejas, M; Fernandez-Turiel, J L

2016-07-01

The Grímsvötn volcanic eruption, from 21 to 28 May, 2011, was the largest eruption of the Grímsvötn Volcanic System since 1873, with a Volcanic Explosivity Index (VEI) of magnitude 4. The main geochemical features of the potential environmental impact of the volcanic ash-water interaction were determined using two different leaching methods as proxies (batch and vertical flow-through column experiments). Ash consists of glass with minor amounts of plagioclase, clinopyroxene, diopside, olivine and iron sulphide; this latter mineral phase is very rare in juvenile ash. Ash grain morphology and size reflect the intense interaction of magma and water during eruption. Batch and column leaching tests in deionised water indicate that Na, K, Ca, Mg, Si, Cl, S and F had the highest potential geochemical fluxes to the environment. Release of various elements from volcanic ash took place immediately through dissolution of soluble salts from the ash surface. Element solubilities of Grímsvötn ash regarding bulk ash composition were <1 %. Combining the element solubilities and the total estimated mass of tephra (7.29 × 10(14) g), the total inputs of environmentally important elements were estimated to be 8.91 × 10(9) g Ca, 7.02 × 10(9) g S, 1.10 × 10(9) g Cl, 9.91 × 10(8) g Mg, 9.91 × 10(8) g Fe and 1.45 × 10(8) g P The potential environmental problems were mainly associated with the release of F (5.19 × 10(9) g).

Characterization of Rare Earth Element Minerals in Coal Utilization Byproducts

Energy Technology Data Exchange (ETDEWEB)

Montross, Scott N. [Oak Ridge Inst. for Science and Education (ORISE), Oak Ridge, TN (United States); Verba, Circe A. [National Energy Technology Lab. (NETL), Albany, OR (United States). Research Innovation Center; Collins, Keith [National Energy Technology Lab. (NETL), Albany, OR (United States). Research Innovation Center

2017-07-17

occurrence of REE mineral phases in CUB and allowed us to calculate structural and volumetric estimates of REE. Collectively, the rock and coal ash samples contained minerals such as quartz, kaolinite, muscovite/illite, iron oxide (as hematite or magnetite), mullite, and clinochlore. Trace minerals included pyrite, zircon, siderite, rutile, diopside, foresterite, gypsum, and barite. We identified REE phosphate minerals monazite (Ce,La,Nd,Th)(PO₄,SiO₄), xenotime (YPO₄,SiO₄), and apatite (Ca₅(PO₄)₃(F,Cl,OH) via SEM and electron microprobe analysis: these materials generally occurred as 1-10 μm-long crystals in the rock and ash samples. As has been shown in other studies, amorphous material-aluminosilicate glass or iron oxyhydroxide-are the major components of coal fly and bottom ash. Trace amounts of amorphous calcium oxide and mixed element (e.g., Al-Si-Ca-Fe) slag are also present. Quartz, mullite, hematite, and magnetite are the crystalline phases present. We found that REEs are present as monomineralic grains dispersed within the ash, as well as fused to or encapsulated by amorphous aluminosilicate glass particles. Monazite and xenotime have relatively high melting points (>1800 °C) compared to typical combustion temperatures; our observations indicate that the REE-phosphates, which presumably contribute a large percentage of REE to the bulk ash REE pool, as measured by mass spectroscopy, are largely unaltered by the combustion. Our study shows that conventional coal combustion processes sequester REE minerals into aluminosilicate glass phases, which presents a new engineering challenge for extracting REE from coal ash. The characterization work summarized in this report provides a semi-quantitative assessments of REE in coal-containing rock and CUB. The data we obtained from 2- and 3-D imaging, elemental mapping, volumetric estimates, and advanced high-resolution pixel classification

Fly Ash Formation during Suspension-Firing of Biomass. Effects of Residence Time and Fuel-Type

DEFF Research Database (Denmark)

Damø, Anne Juul; Jensen, Peter Arendt; Jappe Frandsen, Flemming

2017-01-01

particles were subjected to various analyses, including char burnout level, particle size distribution, elemental composition, and particle morphology and composition. Furthermore, the transient release, i.e. the vaporization of the flame-volatile inorganic elements K, Cl and S, from the burning fuel...... particles to the gas phase, has been quantified by using two different calculation methods. The ash formation mechanisms were found to be quite similar for straw and wood. The degree of conversion (char burn-out level) was generally good at residence times ≥ 1s. The size distribution of the residual fly ash...

The heterogeneous nature of mineral matter, fly-ash and deposits

Energy Technology Data Exchange (ETDEWEB)

Creelman, R.A.; Pohl, J.H.; Devir, G.P.; Su, S. [R.A. Creelman and Associates, Epping, NSW (Australia)

2000-07-01

This paper reports on a series of slagging studies investigating the heterogeneous nature of mineral matter, fly ash and deposits, and how this heterogeneity affects deposition. The data come from low temperature ashing (LTA) of pulverised coal, fly ash from boilers, and deposits from pilot-scale furnaces and boilers. The paper presents optical and scanning electron (SEM) micrographs, electron microprobe analysis (EMPA) and energy dispersive x-ray analysis (EDXRA) of mineral matter, individual fly ash particles, and localised regions of deposits. During combustion, the included mineral matter is transformed into fly ash, melts and partially adheres to the char surface, and may form agglomerated masses. Excluded mineral matter has little chance of encountering another ash particle and agglomerating in the gas phase, but can react with other particles in the wall deposits. Certain fly ash particles adhere to the wall where they can combine with other fly ash particles. Analyses of molten regions of deposits have shown, so far, four mineral phase fields to be responsible for forming difficult deposits with melting points below deposit surface temperatures of 1200 to 1350{sup o}C. These mineral fields include iron cordierite, albite and its silica undersaturated equivalent nepheline, anorthite, and compounds with ratios of Ca to P of 2.3-2.5.

Cementing Efficiency of Low Calcium Fly Ash in Fly Ash Concretes

OpenAIRE

T. D. Gunneswara Rao; Mudimby Andal

2014-01-01

Research on the utilization of fly ash will no longer refer the fly ash as a waste material of thermal power plants. Use of fly ash in concrete making, makes the concrete economical as well as durable. The fly ash is being added to the concrete in three ways namely, as partial replacement to cement, as partial replacement to fine aggregates and as admixture. Addition of fly ash to the concrete in any one of the form mentioned above, makes the concrete more workable and durable than the conven...

Mercury and toxic metals in ash from combustion and incineration processes; Mercurio y metales toxicos en cenizas provenientes de procesos de combustion e incineracion

Energy Technology Data Exchange (ETDEWEB)

Mugica, V.; Amador, M.A.; Torres, M.; Figueroa, J. de J. [Universidad Autonomo-Metropolitana-Azcapotzalco, Reynosa (Mexico)

2003-07-01

In Mexico, most of the ashes from combustion and incineration process were not appropriately disposed, they are either left on industrial yards and cliffs or thrown away in open spaces and then carried by the wind to places where they can harm population, affect aquatic environment or soils. For prevention and control, the knowledge on the concentration of trace elements in waste ashes is necessary. In this study, several oxidation methods for digestion of ashes followed by inductively coupled plasma emission spectrometry were evaluated. Hg, Cd, Cr, Cu, Ni, Pb and V were determined in ashes from coal and fuel oil combustion, as well as in ashes from the incineration of municipal, water treatment sludge, and medical wastes. Results showed important concentrations of different trace elements in the ashes. This suggests that adequate disposal of these wastes should be mandatory. On the other hand, concentration of trace elements in the leachates indicated that these wastes are not toxic and they could be disposed in sanitary landfill. 23 refs.

Preparation Of Pure Carbon From Heavy Oil Fly Ash

International Nuclear Information System (INIS)

ABU ZAID, A.H.M.

2010-01-01

The Egyptian production of heavy oil is approximately 12 million tons of heavy oil per year and approximately 5.3 million tons of this amount is used as fuel in the electric power stations. Based on the fact that the ash content of Egyptian heavy oil is approximately 0.2 %, about 10600 tons of fly ash is produced per/year which causes a lot of environmental problems such as dusting, release of the acidic liquids and heavy metals such as vanadium, nickel, zinc and unburned carbon. Treatment of fly ash by leaching of vanadium and zinc was carried out under different conditions to achieve the best leaching efficiency of both vanadium and zinc by sodium hydroxide. The leaching efficiency obtained was 91% for vanadium and 98% for zinc. This study was concerned with the precipitation of zinc at pH 7.5 as zinc hydroxide and the precipitation of vanadium as ammonium metavanadate at pH 8.5. Leaching of nickel, iron and other elements from the residue was carried out by 2M HCl under different conditions. The achieved leaching efficiency of nickel was 95% where as that of iron was 92%. Precipitation efficiency of both nickel and iron were 99.9%. The residue, which contains mainly unburned carbon, have been washed two times with water and dried at 200 o C then ground to < 300μm. According to the achieved analysis of the obtained carbon, it can be characterized as pure carbon

Emerald ash borer biocontrol in ash saplings: the potential for early stage recovery of North American ash

Science.gov (United States)

In many parts of North America, ash stands have been reduced by the emerald ash borer (Agrilus planipennis) invasion to a few surviving mature trees and young basal sprouts, saplings, and seedlings. Without a seed bank, ash tree recovery will require survival and maturation of these younger cohorts...

Bio fuel ash in a road construction: impact on soil solution chemistry.

Science.gov (United States)

Thurdin, R T; van Hees, P A W; Bylund, D; Lundström, U S

2006-01-01

Limited natural resources and landfill space, as well as increasing amounts of ash produced from incineration of bio fuel and municipal solid waste, have created a demand for useful applications of ash, of which road construction is one application. Along national road 90, situated about 20 km west of Sollefteå in the middle of Sweden, an experiment road was constructed with a 40 cm bio fuel ash layer. The environmental impact of the ash layer was evaluated from soil solutions obtained by centrifugation of soil samples taken on four occasions during 2001-2003. Soil samples were taken in the ash layer, below the ash layer at two depths in the road and in the ditch. In the soil solutions, pH, conductivity, dissolved organic carbon (DOC) and the total concentration of cations (metals) and anions were determined. Two years after the application of the ash layers in the test road, the concentrations in the ash layer of K, SO4, Zn, and Hg had increased significantly while the concentration of Se, Mo and Cd had decreased significantly. Below the ash layer in the road an initial increase of pH was observed and the concentrations of K, SO4, Se, Mo and Cd increased significantly, while the concentrations of Cu and Hg decreased significantly in the road and also in the ditch. Cd was the element showing a potential risk of contamination of the groundwater. The concentrations of Ca in the ash layer indicated an ongoing hardening, which is important for the leaching rate and the strength of the road construction.

Exploring evaluation to influence the quality of pulverized coal fly ash. Co-firing of biomass in a pulverized coal plant or mixing of biomass ashes with pulverized coal fly ash; Verkennende evaluatie kwaliteitsbeinvloeding poederkoolvliegas. Bijstoken van biomassa in een poederkoolcentrale of bijmenging van biomassa-assen met poederkoolvliegas

Energy Technology Data Exchange (ETDEWEB)

Van der Sloot, H.A.; Cnubben, P.A.J.P [ECN Schoon Fossiel, Petten (Netherlands)

2000-08-01

In this literature survey the consequences of co-firing of biomass and mixing of biomass ash with coal fly ash on the coal fly ash quality is evaluated. Biomass ash considered in this context is produced by gasification, pyrolysis or combustion in a fluidized bed. The irregular shape of biomass ash obtained from gasification, pyrolysis or combustion has a negative influence on the water demand in concrete applications of the coal fly ash resulting from mixing biomass ash and coal fly ash. In case of co-firing, high concentrations of elements capable of lowering the ash melting point (e.g., Ca and Mg) may lead to more ash agglomeration. This leads to a less favourable particle size distribution of the coal fly ash, which has a negative impact on the water demand in cement bound applications. Gasification, pyrolysis and combustion may lead to significant unburnt carbon levels (>10%). The unburnt carbon generally absorbs water and thus has a negative influence on the water demand in cement-bound applications. The contribution of biomass ash to the composition of coal fly ash will not be significantly different, whether the biomass is co-fired or whether the biomass ash is mixed off-line with coal fly ash. The limit values for Cl, SO4 and soluble salts can form a limitation for the use of coal fly ash containing biomass for cement-bound applications. As side effects of biomass co-firing, the level of constituents such as Na, K, Ca and Mg may lead to slagging and fouling of the boiler. In addition, a higher emission of flue gas contaminants As, Hg, F, Cl and Br may be anticipated in case more contaminated biomass streams are applied. This may also lead to a higher contamination level of gypsum produced from flue gas cleaning residues. Relatively clean biomass streams (clean wood, cacao shells, etc.) will hardly lead to critical levels of elements from a leaching point of view. More contaminated streams, such as sewage sludge, used and preserved wood, petcoke and RDF

Assessing the effects of FBC ash treatments of metal-contaminated soils using life history traits and metal bioaccumulation analysis of the earthworm Eisenia andrei

Energy Technology Data Exchange (ETDEWEB)

Grumiaux, F.; Demuynck, S.; Schikorski, D.; Lemiere, S.; Lepretre, A. [Universite Lille Nord de France, Villeneuve Dascq (France)

2010-03-15

Earthworms (Eisenia andrei) were exposed, in controlled conditions, to metal-contaminated soils previously treated in situ with two types of fluidized bed combustion ashes. Effects on this species were determined by life history traits analysis. Metal immobilizing efficiency of ashes was indicated by metal bioaccumulation. Ashes-treated soils reduced worm mortality compared to the untreated soil. However, these ashes reduced both cocoon hatching success and hatchlings numbers compared to the untreated soil. In addition, sulfo-calcical ashes reduced or delayed worm maturity and lowered cocoon production compared to silico-alumineous ones. Metal immobilizing efficiency of ashes was demonstrated for Zn, Cu and to a lesser extent Pb. Only silico-alumineous ashes reduced Cd bioaccumulation, although Cd was still bioconcentrated. Thus, although ash additions to metal-contaminated soils may help in immobilizing metals, their use might result, depending on the chemical nature of ashes, to severe detrimental effects on earthworm reproduction with possible long term consequences to populations.

Modelling optimization involving different types of elements in finite element analysis

International Nuclear Information System (INIS)

Wai, C M; Rivai, Ahmad; Bapokutty, Omar

2013-01-01

Finite elements are used to express the mechanical behaviour of a structure in finite element analysis. Therefore, the selection of the elements determines the quality of the analysis. The aim of this paper is to compare and contrast 1D element, 2D element, and 3D element used in finite element analysis. A simple case study was carried out on a standard W460x74 I-beam. The I-beam was modelled and analyzed statically with 1D elements, 2D elements and 3D elements. The results for the three separate finite element models were compared in terms of stresses, deformation and displacement of the I-beam. All three finite element models yield satisfactory results with acceptable errors. The advantages and limitations of these elements are discussed. 1D elements offer simplicity although lacking in their ability to model complicated geometry. 2D elements and 3D elements provide more detail yet sophisticated results which require more time and computer memory in the modelling process. It is also found that the choice of element in finite element analysis is influence by a few factors such as the geometry of the structure, desired analysis results, and the capability of the computer

Synthesis and comparison of mechanical behavior of fly ash-epoxy and silica fumes-epoxy composite

Science.gov (United States)

Sangamesh; Ravishankar, K. S.; Kulkarni, S. M.

2017-08-01

Present day innovation requires materials with a typical combination of properties that are not possible by conventional metal, alloys, ceramics and polymeric materials. Particulate reinforcements for polymers are selected with the dual objective of improving composite properties and save on the total cost of the system. The point of this study is to utilize and compare the mechanical properties of filler (fly ash and silica fumes) reinforced epoxy composites. The composites of different proportions by percentage of matrix (100%), fillers (5%, 10% and 15%) volume are developed using hand lay-up process are tested for tensile and compression, according to ASTM Standards. From these mechanical properties, the flexural analysis of these composites is simulated. And which are characterized by Scanning electron microscopy for the fracture surface study, which reveals the brittle fracture, this also conforms from the Finite element analysis (FEA). And the overall mechanical properties of the fly ash reinforced polymer composites were found to have better than silica fumes reinforced composites.

Column leaching from a Danish forest soil amended with wood ashes: fate of major and trace elements

DEFF Research Database (Denmark)

Maresca, Alberto; Hansen, M.; Ingerslev, M.

2018-01-01

Application of wood ashes onto two Danish forest soil horizons (A- and O-horizons) was investigated through a series of column experiments for ash dosages of 3, 9 and 30 Mg ha−1. Developments in the composition of the percolating soil solutions were investigated both in a short- (below 0.5 m3 m−2...

Leaching and retention of nutrients and trace elements in peat nineteen years after wood ash application and afforestation of a terminated peat cutover area; Utlakning och retention av naeringsaemnen och spaaraemnen i torv nitton aar efter vedasktillfoersel och beskogning paa en avslutad torvtaekt

Energy Technology Data Exchange (ETDEWEB)

Nilsson, Torbjoern; Lundin, Lars (Dept. of Forest Soils, Swedish Univ. of Agricultural Sciences, P.O. Box 7001, SE-750 07 Uppsala (Sweden))

2008-04-15

Ash application on peatlands for improved biomass production attracts great interest. On drained peatlands in forestry use, application of wood ash would increase the forest production. Before such activities starts on a large-scale, the existing knowledge in this field should be compiled, with the aim to illustrate positive and negative effects of such a measure and to suggest recommendations for wood ash application to drained and afforested peatlands. The aim of this project was to investigate how much of different nutrients and trace elements that was still left in the peat, 19 years after application of 23 tonnes of wood fly ash, 0.6 tonnes of raw phosphate and 0.25 tonnes of superphosphate per hectare to 14 hectares of a terminated peat cutover area. This area was located on a mire, Flakmossen, in west-central Sweden. As it was nearly 40 years since peat harvesting had terminated on this mire, the area was drained before the application of wood ash and phosphorus fertilizer. A tractor-driven cultivator mixed the applied fertilizers with the upper 30-40 cm of the remaining peat and afterwards different tree species were planted in the cultivated peat. Peat sampling, down to 80 cm depth, was carried out before soil treatment, one year after, three years after and 19 years after the soil treatment. Analyses of these peat samples showed that: - After the soil treatments an initial increase of pH in the upper peat layers (0-40 cm depth) was observed, but 19 years after the soil treatments pH had decreased to levels that were lower than before the treatments. This decrease in pH was probably due to an oxidation of sulphur compounds in the peat, which was a result of the drainage. This acidification of the peat could not be buffered by the large dose of applied wood ash. However, it should be observed that the main part of the peat in this field study consists of reed peat, that has a considerable higher sulphur content than other peat types. - Nineteen years after

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, environmental view point, the placement of ashes in layers above the liner is more critical than within the liner.

Dispersed Volcanic Ash in Sediment Entering NW Pacific Ocean Subduction Zones: Towards a Regional Perspective

Science.gov (United States)

Scudder, R. P.; Murray, R. W.; Underwood, M.; Kutterolf, S.; Plank, T.; Dyonisius, M.; Arshad, M. A.

2011-12-01

Volcanic ash has long been recognized to be an important component of the global sedimentary system. Ash figures prominently in a number of sedimentary and petrophysical investigations, including how the fluid budget of subducting sediment will be affected by hydration/dehydration reactions. Additionally, many studies focus on discrete ash layers, and how to link their presence with volcanism, climate, arc evolution, biological productivity, and other processes. Less widely recognized is the ash that is mixed into the bulk sediment, or "dispersed" ash. Dispersed ash is quantitatively significant and is an under-utilized source of critical geochemical and tectonic information. Based on geochemical studies of ODP Site 1149, a composite of DSDP Sites 579 & 581, as well as IODP Sites C0011 & C0012 drilled during Expedition 322, we will show the importance of dispersed ash to the Izu-Bonin-Marianas, Kurile-Kamchatka and Nankai subduction zones. Initial geochemical analyses of the bulk sediment, as related to dispersed ash entering these subduction systems are presented here. Geochemical analysis shows that the characteristics of the three sites exhibit some variability consistent with observed lithological variations. For example, the average SiO2/Al2O3 ratios at Site 1149, Site C0011 and Site C0012 average 3.7. The composite of Sites 579 & 581 exhibits a higher average of 4.6. There are contrasts between other key major elemental indicators as well (e.g., Fe2O3). Ternary diagrams such as K2O-Na2O-CaO show that there are at least two distinct geochemical fields with Sites 1149, C0011 and C0012 clustering in one and Sites 579 & 581 in the other. Q-mode Factor Analysis was performed on the bulk sediment chemical data in order to determine the composition of potential end members of these sites. The multivariate statistics indicate that Site 1149 has 3-4 end members, consistent with the results of Scudder et al. (2009, EPSL, v. 284, pp 639), while each of the other sites

Sieving of municipal solid waste incineration (MSWI) bottom ash; Siktning av askor fraan avfallsfoerbraenning

Energy Technology Data Exchange (ETDEWEB)

Todorovic, Jelena

2010-07-01

Waste-to-Energy is steadily increasing in Sweden and more than 46 % of municipal solid waste (MSW) is being incinerated. Solid residues from MSW incineration (MSWI) mainly constitute of bottom ash and air pollution control (APC) residues. Bottom ashes from MSWI amounted to 0.7 millions of tons and APC residues to 0.2 millions of tons in 2008. Bottom ashes from MSWI contain pollutants like metals (e.g. Pb, Zn, Cu), metalloids (e.g. As, Se), elements forming oxyanions (e.g. Sb, Cr, Mo) and easily soluble salts like chlorides and sulphates. These constituents can leach out polluting the environment if ash comes in contact with water. Treatment methods for decreasing the amount of pollutants in ashes or their mobility are therefore needed. Sieving was investigated as a separate or a complementary treatment method for MSWI ashes. Hypothesis was that the large share of pollutant concentrations could be removed from the ashes through separation of the finest fractions. The rest is less harmful to the environment, more acceptable as secondary construction material or less costly to landfill. Investigation included three MSWI ashes, namely bottom ash from Boraas Energy och Miljoe's plant with fluid bad, boiler ash from the same plant and bottom ash from Renova's stocker grate type plant. Ashes were sieved in 2-4 size fractions. Total content of pollutants and their leachability (batch leaching test, L/S=10 l/kg) was assessed for each of the fractions. Leaching results were compared to limit values stipulated by Swedish Environmental Protection Agency for acceptance of waste at landfills as wells as to recommendations for reuse of waste as a construction material. Results from bottom ash from the stocker grate type incinerator and from the boiler ash confirm the hypothesis that pollutants leach out in higher concentrations from the finer fractions. A large amount of pollutant could be removed from the ashes through sieving, but the goal to produce a fraction that

Can pore-clogging by ash explain post-fire runoff?

Science.gov (United States)

Stoof, Cathelijne R.; Gevaert, Anouk I.; Baver, Christine; Hassanpour, Bahareh; Morales, Veronica L.; Zhang, Wei; Martin, Deborah; Giri, Shree K.; Steenhuis, Tammo S.

2016-01-01

Ash plays an important role in controlling runoff and erosion processes after wildfire and has frequently been hypothesised to clog soil pores and reduce infiltration. Yet evidence for clogging is incomplete, as research has focussed on identifying the presence of ash in soil; the actual flow processes remain unknown. We conducted laboratory infiltration experiments coupled with microscope observations in pure sands, saturated hydraulic conductivity analysis, and interaction energy calculations, to test whether ash can clog pores (i.e. block pores such that infiltration is hampered and ponding occurs). Although results confirmed previous observations of ash washing into pores, clogging was not observed in the pure sands tested, nor were conditions found for which this does occur. Clogging by means of strong attachment of ash to sand was deemed unlikely given the negative surface charge of the two materials. Ponding due to washing in of ash was also considered improbable given the high saturated conductivity of pure ash and ash–sand mixtures. This first mechanistic step towards analysing ash transport and attachment processes in field soils therefore suggests that pore clogging by ash is unlikely to occur in sands. Discussion is provided on other mechanisms by which ash can affect post-fire hydrology.

Geotechnical properties of ash deposits near Hilo, Hawaii

Science.gov (United States)

Wieczorek, G.F.; Jibson, R.W.; Wilson, R.C.; Buchanan-Banks, J. M.

1982-01-01

Two holes were hand augered and sampled in ash deposits near Hilo, Hawaii. Color, water content and sensitivity of the ash were measured in the field. The ash alternated between reddish brown and dark reddish brown in color and had water contents as high as 392%. A downhole vane shear device measured sensitivities as high as 6.9. A series of laboratory tests including grain size distribution, Atterberg limits, X-ray diffraction analysis, total carbon determination, vane shear, direct shear and triaxial tests were performed to determine the composition and geotechnical properties of the ash. The ash is very fine grained, highly plastic and composed mostly of gibbsite and amorphous material presumably allophane. The ash has a high angle of internal friction ranging from 40-43? and is classified as medium to very sensitive. A series of different ash layers was distinguished on the basis of plasticity and other geotechnical properties. Sensitivity may be due to a metastable fabric, cementation, leaching, high organic content, and thixotropy. The sensitivity of the volcanic ash deposits near Hilo is consistent with documented slope instability during earthquakes in Hawaii. The high angles of internal friction and cementation permit very steep slopes under static conditions. However, because of high sensitivity of the ash, these slopes are particularly susceptible to seismically-induced landsliding.

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)

Volcanic Ash Data Assimilation System for Atmospheric Transport Model

Science.gov (United States)

Ishii, K.; Shimbori, T.; Sato, E.; Tokumoto, T.; Hayashi, Y.; Hashimoto, A.

2017-12-01

The Japan Meteorological Agency (JMA) has two operations for volcanic ash forecasts, which are Volcanic Ash Fall Forecast (VAFF) and Volcanic Ash Advisory (VAA). In these operations, the forecasts are calculated by atmospheric transport models including the advection process, the turbulent diffusion process, the gravitational fall process and the deposition process (wet/dry). The initial distribution of volcanic ash in the models is the most important but uncertain factor. In operations, the model of Suzuki (1983) with many empirical assumptions is adopted to the initial distribution. This adversely affects the reconstruction of actual eruption plumes.We are developing a volcanic ash data assimilation system using weather radars and meteorological satellite observation, in order to improve the initial distribution of the atmospheric transport models. Our data assimilation system is based on the three-dimensional variational data assimilation method (3D-Var). Analysis variables are ash concentration and size distribution parameters which are mutually independent. The radar observation is expected to provide three-dimensional parameters such as ash concentration and parameters of ash particle size distribution. On the other hand, the satellite observation is anticipated to provide two-dimensional parameters of ash clouds such as mass loading, top height and particle effective radius. In this study, we estimate the thickness of ash clouds using vertical wind shear of JMA numerical weather prediction, and apply for the volcanic ash data assimilation system.

Composite Ni-Co-fly ash coatings on 5083 aluminium alloy

Energy Technology Data Exchange (ETDEWEB)

Panagopoulos, C.N., E-mail: chpanag@metal.ntua.gr [Laboratory of Physical Metallurgy, National Technical University of Athens, Zografos, 15780 Athens (Greece); Georgiou, E.P.; Tsopani, A.; Piperi, L. [Laboratory of Physical Metallurgy, National Technical University of Athens, Zografos, 15780 Athens (Greece)

2011-03-15

Ni-Co-fly ash coatings were deposited on zincate treated 5083 wrought aluminium alloy substrates with the aid of the electrodeposition technique. Structural and chemical characterization of the produced composite coatings was performed with the aid of X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron dispersive X-ray analysis (EDS) techniques. The Ni-Co-fly ash coatings were found to consist of a crystalline Ni-Co solid solution with dispersed fly ash particles. In addition, chemical analysis of the Ni-Co matrix showed that it consisted of 80 wt.% Ni and 20 wt.% Co. The co-deposition of fly ash particles leads to a significant increase of the microhardness of the coating. The corrosion behaviour of the Ni-Co-fly ash/zincate coated aluminium alloy, in a 0.3 M NaCl solution (pH = 3.5), was studied by means of potentiodynamic corrosion experiments.

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. Copyright © 2011 Elsevier Ltd. All rights reserved.

Pengaruh Penambahan Limbah Padat Abu Terbang Batubara(fly Ash) Terhadap Kekuatan Tekan Dan Porositas Genteng Tanah Liat Kabupaten Pringsewu

OpenAIRE

Febriyansyah, Puji; Tarkono,; Zulhanif,

2013-01-01

Fly ash, chemicallyis analumino-silicamineral containing Ca, K, and Na elements, fly ash has amoderate to high bonding capacity characteristic , and has acement-forming properties. In this study the authors use the industrial fly ash coal waste as an alternative mixture of tile manufacture. The tiles manufactured by mixing clay, sand, water and fly ash. Then smoothed with ekstuder machine and forming kuweh then aerate for 3 days, before do the dieing process . Tile dried for 4 days, then do f...

Calcium phosphate stabilization of fly ash with chloride extraction.

Science.gov (United States)

Nzihou, Ange; Sharrock, Patrick

2002-01-01

Municipal solid waste incinerator by products include fly ash and air pollution control residues. In order to transform these incinerator wastes into reusable mineral species, soluble alkali chlorides must be separated and toxic trace elements must be stabilized in insoluble form. We show that alkali chlorides can be extracted efficiently in an aqueous extraction step combining a calcium phosphate gel precipitation. In such a process, sodium and potassium chlorides are obtained free from calcium salts, and the trace metal ions are immobilized in the calcium phosphate matrix. Moderate calcination of the chemically treated fly ash leads to the formation of cristalline hydroxylapatite. Fly ash spiked with copper ions and treated by this process shows improved stability of metal ions. Leaching tests with water or EDTA reveal a significant drop in metal ion dissolution. Hydroxylapatite may trap toxic metals and also prevent their evaporation during thermal treatments. Incinerator fly ash together with air pollution control residues, treated by the combined chloride extraction and hydroxylapatite formation process may be considered safe to use as a mineral filler in value added products such as road base or cement blocks.

Emerald Ash Borer Threat Reveals Ecohydrologic Feedbacks in Northern U.S. Black Ash Wetlands

Science.gov (United States)

Diamond, J.; Mclaughlin, D. L.; Slesak, R.

2016-12-01

Hydrology is a primary driver of wetland structure and process that can be modified by abiotic and biotic feedbacks, leading to self-organization of wetland systems. Large-scale disturbance to these feedbacks, such as loss of vegetation, can thus be expected to impact wetland hydrology. The Emerald Ash Borer is an invasive beetle that is expected to cause widespread-loss of ash trees throughout the northern U.S. and Canada. To predict ecosystem response to this threat of vegetation loss, we ask if and how Black Ash (Fraxinus nigra), a ubiquitous facultative-wetland ash species, actively controls wetland hydrology to determine if Black Ash creates favorable hydrologic regimes for growth (i.e., evidence for ecohydrologic feedbacks). We do this by taking advantage of plot-level tree removal experiments in Black Ash-dominated (75-100% basal area) wetlands in the Chippewa National Forest, Minnesota. The monospecies dominance in these systems minimizes variation associated with species-specific effects, allowing for clearer interpretation of results regarding ecohydrologic feedbacks. Here, we present an analysis of six years of water table and soil moisture time series in experimental plots with the following treatments: 1) clear cut, 2) girdling, 3) group-selection thinning, and 4) control. We also present evapotranspiration (ET) time series estimates for each experimental plot using analysis of diel water level variation. Results show elevated water tables in treatment plots relative to control plots for all treatments for several years after treatments were applied, with differences as great as 50 cm. Some recovery of water table to pre-treatment levels was observed over time, but only the group-selection thinning treatment showed near-complete recovery to pre-treatment levels, and clear-cut treatments indicate sustained elevated water tables over five years. Differences among treatments are directly attributed to variably reduced ET relative to controls. Results also

Bulk analysis of coal

International Nuclear Information System (INIS)

Sowerby, B.D.

1982-01-01

Nuclear techniques used in the coal industry to determine specific energy, ash and moisture are outlined. Ash analysis by radioisotope X-ray techniques include a single X-ray measurement using a transmission or backscatter geometry and techniques with compensation for iron variations. Neutron techniques can be used to measure the concentration of some specific elements in coal. The measurement of specific energy, ash and moisture then depends on the correlation of the particular parameter with the measured elemental composition. Carbon can be determined by a combination of a measurement of 4.43 MeV 12 C gamma-rays from neutron inelastic scattering with a separate 60 Co gamma-ray scattering measurement. Sulphur meters are based on the measurement of 5.42 MeV neutron capture of gamma rays

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.

Environmental systems analysis for the beneficial use of ashes in constructions; Miljoesystemanalys foer nyttiggoerande av askor i anlaeggningsbyggande

Energy Technology Data Exchange (ETDEWEB)

Kaerrman, Erik; Olsson, Susanna; Magnusson, Ylva; Peterson, Anna [Ecoloop, Stockholm (Sweden)

2006-02-15

All building materials have an impact on the environment, conventional materials as well as recycled materials. But, since recycled materials are classified as waste, the use of them is more strongly restricted. The potential of saving natural materials and energy by the use of recycling materials are rarely considered. This report presents a method for environmental systems analysis considering the use of recycled materials in a wide perspective. Various scenarios for beneficial use or disposal of the residuals that occur in a region (province, county or municipality) are analysed. The method considers emissions to air and water as well as conservation of natural resources and energy. Two case studies have been carried out for the Uppsala County in Sweden. Case study 1 dealt with municipal solid waste incineration (MSWI) bottom ash, where scenarios for beneficial use of ashes in 1) drainage layers in covering of landfills and 2) road construction were compared. Also a third scenario was included as a reference where the MSWI bottom ash was landfilled. The result of case study 1 showed that the use of ashes in road construction was the most beneficial alternative in terms of conservation of natural resources and energy, and also in terms leakage of several metals. The leakage of Arsenic and Zink were however more favourable in scenario 1 and the leakage of copper was more favourable in scenario 3. The second alternative where the ashes were used in drainage layer did not save as much natural resources and caused more emissions of heavy metals to water compared to the road construction application. In case study 2 the beneficial use of fly ash from peat combustion was analysed, including 1) the use of peat ash as a construction material in small county roads, 2) the use of peat ash mixed with sewage sludge as a covering material on landfills. Also this case study included a reference scenario in which the peat ash, generated in Uppsala County, was landfilled. The

Radiobiological waste treatment-ashing treatment and immobilization with cement

Energy Technology Data Exchange (ETDEWEB)

Shengtao, Feng; Li, Gong; Li, Cheng; Benli, Wang; Lihong, Wang [China Inst. for Radiation Protection, Taiyuan, Shanxi (China)

1997-02-01

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 DH{sub 4A} 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 DH{sub 4A} 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, DH{sub 4A} 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.

Radiobiological waste treatment-ashing treatment and immobilization with cement

International Nuclear Information System (INIS)

Feng Shengtao; Gong Li; Cheng Li; Wang Benli; Wang Lihong

1997-01-01

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 DH 4A 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 DH 4A 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, DH 4A 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

Ashes to ashes: Large Fraxinus germplasm collections and their fates

Science.gov (United States)

Kim C. Steiner; Paul. Lupo

2010-01-01

As the emerald ash borer (EAB) threatens the survival of our ash species, measures should be taken to preserve their genetic variability in the event that we discover a way to restore populations destroyed by the beetle. As it happens, large germplasm collections exist for our most important and widely distributed eastern species of the genus, white ash (...

The Source of Volcanic Ash in Late Classic Maya Pottery at El Pilar, Belize

Science.gov (United States)

Catlin, B. L.; Ford, A.; Spera, F. J.

2007-12-01

The presence of volcanic ash used as temper in Late Classic Maya pottery (AD 600-900) at El Pilar has been long known although the volcano(s) contributing ash have not been identified. We use geochemical fingerprinting, comparing compositions of glass shards in potsherds with volcanic sources to identify the source(s). El Pilar is located in the Maya carbonate lowlands distant from volcanic sources. It is unlikely Maya transported ash from distant sites: ash volumes are too large, the terrain too rugged, and no draft animals were available. Ash layer mining is unlikely because mine sites have not been found despite intensive surveys. Nearest volcanic sources to El Pilar, Belize and Guatemala, are roughly 450 km to the south and east. The ash found in potsherds has a cuspate morphology. This suggests ash was collected during, or shortly after, an ash airfall event following eruption. Analyses of n=333 ash shards from 20 ceramic (pottery) sherds was conducted by electron microprobe for major elements, and LA-ICPMS for trace elements and Pb isotopes. These analyses can be compared to volcanic materials from candidate volcanoes in the region. The 1982 El Chichon eruption caused airfall deposition (archaeological samples and El Chichon has been made. The atomic ratios of La/Yb, Nb/Ta, Zr/Hf, Sr/Ba and Th/U of n=215 glass shards in the potsherds are 12.2±7.1, 10.9±3.4, 31.2±11.5, 0.09±0.05 and 2.5±0.9, respectively. These ratios for 1982 El Chichon are 15.4±2.1, 26.3, 36.1±5.3, 1.4±0.06 and 3.16, respectively. Data for the 1475 AD El Chichon eruption (Macias et al, 2003) can also be compared; the ratios from are 13.2±2.2, 7.3±1.8, 30.4±9.6, 1.51±0.4 and 2.88±0.23, respectively. The mean 208Pb/206Pb ratio of n=5 potsherds is 2.0523±0.002 compared to 2.0514±0.00074 for n=7 samples from El Chichon. The two most recent eruptions from El Chichon overlap with the potsherd glass data except for Sr/Ba, which might be modified by Sr-Ca exchange during firing. In

Fusion characterization of biomass ash

Energy Technology Data Exchange (ETDEWEB)

Ma, Teng [State Key Laboratory ofMultiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, No. 1 Zhongguancun North Second Street, Beijing 100190 (China); Sino-Danish Center for Education and Research, Beijing, 100190 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Fan, Chuigang; Hao, Lifang [State Key Laboratory ofMultiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, No. 1 Zhongguancun North Second Street, Beijing 100190 (China); Li, Songgeng, E-mail: sgli@ipe.ac.cn [State Key Laboratory ofMultiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, No. 1 Zhongguancun North Second Street, Beijing 100190 (China); Song, Wenli [State Key Laboratory ofMultiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, No. 1 Zhongguancun North Second Street, Beijing 100190 (China); Lin, Weigang [State Key Laboratory ofMultiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, No. 1 Zhongguancun North Second Street, Beijing 100190 (China); Department of Chemical and Biochemical Engineering, Technical University of Denmark, 2800 Kgs. Lyngby (Denmark)

2016-08-20

Highlights: • A novel method is proposed to analyze fusion characteristics of biomass ash. • T{sub m} can represent the severe melting temperature of biomass ash. • Compared with AFT, TMA is the better choice to analyze the fusion characteristics of biomass ash. - Abstract: 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, T{sub m}, 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.

Ash related bed agglomeration during fluidized bed combustion, further development of the classification method based on CCSEM; CCSEM-luokitusmenetelmaen jatkokehittaeminen tuhkan aiheuttaman agglomeroitumisen tutkimisessa leiju- ja kiertopetipoltossa

Energy Technology Data Exchange (ETDEWEB)

Laitinen, R; Patrikainen, T; Heikkinen, R; Tiainen, M; Virtanen, M [Oulu Univ. (Finland). Inst. of Chemistry

1997-10-01

The scope of this project is to use the information and experience gained from the development of classification method to predict ash related problems like bed agglomeration during fluidised combustion. If boilers have to be shut down due to slagging or agglomeration of the bed material may cause significant economic losses for the entire energy production chain. Mineral classification methods based on the scanning electron microscopy are commonly used for coal ash investigation. In this work different biomass, peat, and peat-wood ash, fluidised-bed materials, and bed agglomerates were analysed with SEM-EDS combined with automatic image analysis software. The properties of ash particles are different depending on the fuel type. If biomass like wood or bark are added to peat the resulting ash has different properties. Due to the low mineral content in the original peat and to the fact that the majority of inorganic material is bound to the organic matrix, the classification has turned out to be less informative than was hoped. However, good results are obtained the by use of quasiternary diagrams. With these diagrams the distribution of particle composition is easily illustrated and thus meaningful prediction can be made of the slagging and agglomerating properties of ash. The content of ten different elements are determined for each particle by SEM-EDS combined with Link AIA software. The composition of the diagram corners can be varied Freely within these ten elements. (orig.)

Synthesis of a nano-crystalline solid acid catalyst from fly ash and its catalytic performance

Energy Technology Data Exchange (ETDEWEB)

Chitralekha Khatri; Ashu Rani [Government P.G. College, Kota (India). Environmental Chemistry Laboratory

2008-10-15

The synthesis of nano-crystalline activated fly ash catalyst (AFAC) with crystallite size of 12 nm was carried out by chemical and thermal treatment of fly ash, a waste material generated from coal-burning power plants. Fly ash was chemically activated using sulfuric acid followed by thermal activation at 600{sup o}C. The variation of surface and physico-chemical properties of the fly ash by activation methods resulted in improved acidity and therefore, catalytic activity for acid catalyzed reactions. The AFAC was characterized by X-ray diffraction, FT-IR spectroscopy, N{sub 2}-adsorption-desorption isotherm, scanning electron microscopy, flame atomic absorption spectrophotometry and sulfur content by CHNS/O elemental analysis. It showed amorphous nature due to high silica content (81%) and possessed high BET surface area (120 m{sup 2}/g). The catalyst was found to be highly active solid acid catalyst for liquid phase esterification of salicylic acid with acetic anhydride and methanol giving acetylsalicylic acid and methyl salicylate respectively. A maximum yield of 97% with high purity of acetylsalicylic acid (aspirin) and a very high conversion 87% of salicylic acid to methyl salicylate (oil of wintergreen) was obtained with AFAC. The surface acidity and therefore, catalytic activity in AFAC was originated by increased silica content, hydroxyl content and higher surface area as compared to fly ash. The study shows that coal generated fly ash can be converted into potential solid acid catalyst for acid catalyzed reactions. Furthermore, this catalyst may replace conventional environmentally hazardous homogeneous liquid acids making an ecofriendly; solvent free, atom efficient, solid acid based catalytic process. 27 refs., 5 figs., 2 tabs.

Suitability of untreated wood ash for recycling; Qualitaet und Verwertungsmoeglichkeiten von Holzaschen aus naturbelassenen Hoelzern

Energy Technology Data Exchange (ETDEWEB)

Stahl, E. [Fraunhofer-Inst. fuer Umwelt-, Sicherheits- und Energietechnik, UMSICHT, Oberhausen (Germany); Doetsch, P. [RWTH Aachen (Germany). Lehr- und Forschungsgebiet Abfallwirtschaft

2008-10-15

Background, aim and scope: The increasing use of wood for generating heat and electricity requires that more and more fuels be obtained directly or indirectly from the forest. Sound, sustainable recycling management calls for the return of any generated wood ash back to the forest to make use of the nutrients it contains. Similarly, recycling this ash in other locations such as agricultural land or private gardens can serve equally well as fertilizer. At the same time, it is critical that no accumulated pollutants be introduced into the nutrient loop. Wood ash that is heavily laden with such pollutants must not be considered for recycling. As part of this research project, commissioned by the Ministry for the Environment and Conservation, Agriculture and Consumer Protection of the State of North Rhine-Westphalia in Germany (MUNLV), ash samples of 209 woodfired appliances generating between 10 and 4000 kW of heat performance were taken from throughout the federal state of North Rhine-Westphalia. Untreated wood, either forested or scrap, was used as the sole fuel for these appliances. Materials and methods: All course ash and fly ash samples were analyzed to determine their composition of main nutrients, heavy metals, and the elements Fe, Cl, Si, Al and Na. The purpose of this analysis was to evaluate the suitability of this wood ash for reintroduction to forest soils or as fertilizer in other types of soil. Results: The majority of the wood ash samples in this study contained sufficiently high amounts of nutrients to match the requirement for stand-alone fertilizers (PK-fertilizer, potash fertilizer). However, the heavy metal content was highly variable, with a mean content high enough to prohibit them from being classified per se as PK- or potash fertilizer for agricultural land. Due to the high quantities of cadmium, application of this ash to garden soils would likewise be ill-advised. Discussion: On forest soils German law permits application of a mixture of

Incineration of a typical LWR combustible waste and analysis of the resulting ash

International Nuclear Information System (INIS)

Treat, R.L.; Lokken, R.O.; Schliebe, M.J.

1983-05-01

In this study 4540 kg (10,000 lb) of simulated nuclear power plant combustion wastes were burned in a controlled-air incinerators. The purpose of this work was to generate ashes suitable for solidification, the products of which will be analyzed to determine if they are suitable for disposal. Two different types of waste were burned: resin and simulated crud, and general trash (paper, plastics, wood, rubber, and cloth). Volume-reduction ratios (unburned waste: ash) were 13:1 and 22:1, respectively. Approximately 20% of the ash was lost due to adherence to incinerator walls and entrainment in the off-gas stream. Losses of the volatile species cesium and iodine were 79% and 100%, respectively. The ashes were not hygroscopic, but they exhibited a pH of 4.6 to 5.0 when water was added. Corrosion of mild steel drums would occur within this pH range. The ashes contained a significant quantity of clinkers haveing lengths as great as 20 cm (8 in.). Most of the clinkers were fully incinerated and easy to crush, suggesting that standard comminuting equipment should be effective in reducing the size of clinkers to allow their solidification with the fine ashes

Analysis of radioactivity in coal, cinders, fly ash and discharges from the stack

International Nuclear Information System (INIS)

Meide, A.

1985-01-01

Gamma measurements of coal samples originating from several supplying countries proved that the South African coal has about double U-238 and Ra-226 concentration and about treble Th-232 concentration compared to coal from the other countries. Gamma measurements of coal, cinders and fly ash samples from five coal-fueled plants indicate somewhat higher concentrations of Th-232 in cinders and U-238 and Th-232 in fly ashes than those described in literature. The ratio Po-210/Pb-210 was about 2 for fly ash particulates <35μ. A positive correlation between ash percentage and radioactivity of coal might be assumed. (EG)

Mercury release from fly ashes and hydrated fly ash cement pastes

Science.gov (United States)

Du, Wen; Zhang, Chao-yang; Kong, Xiang-ming; Zhuo, Yu-qun; Zhu, Zhen-wu

2018-04-01

The large-scale usage of fly ash in cement and concrete introduces mercury (Hg) into concrete structures and a risk of secondary emission of Hg from the structures during long-term service was evaluated. Three fly ashes were collected from coal-fired power plants and three blend cements were prepared by mixing Ordinary Portland cement (OPC) with the same amount of fly ash. The releasing behaviors of Hg0 from the fly ash and the powdered hydrated cement pastes (HCP) were measured by a self-developed Hg measurement system, where an air-blowing part and Hg collection part were involved. The Hg release of fly ashes at room temperature varied from 25.84 to 39.69 ng/g fly ash during 90-days period of air-blowing experiment. In contrast, the Hg release of the HCPs were in a range of 8.51-18.48 ng/g HCP. It is found that the Hg release ratios of HCPs were almost the same as those of the pure fly ashes, suggesting that the hydration products of the HCP have little immobilization effect on Hg0. Increasing temperature and moisture content markedly promote the Hg release.

Ash layer at ∼ 8 Ma in ODP site 758 from the Bay of Bengal: evidence from Sr, Nd isotopic compositions and rare earth elements

International Nuclear Information System (INIS)

Padmakumari, V.M.; Ahmad, S.M.

2004-01-01

Strontium and neodymium isotopic compositions are widely used to delineate the provenance of sedimentary formations. These isotopes have characteristic signatures for crust and mantle material and therefore can distinguish between volcanic and other rock types. 87 Sr/ 86 Sr. ε Nd (0) and rare earth elements REE of clay sediments from ODP site 758 in the Bay of Bengal is reported here. Our results clearly show that Sr and Nd isotopes can identify thin ash layers that otherwise may not easily be recognized

Physical and chemical characterization of fly ashes from Swiss waste incineration plants and determination of the ash fraction in the nanometer range.

Science.gov (United States)

Buha, Jelena; Mueller, Nicole; Nowack, Bernd; Ulrich, Andrea; Losert, Sabrina; Wang, Jing

2014-05-06

Waste incineration had been identified as an important source of ultrafine air pollutants resulting in elaborated treatment systems for exhaust air. Nowadays, these systems are able to remove almost all ultrafine particles. However, the fate of ultrafine particles caught in the filters has received little attention so far. Based on the use of engineered nano-objects (ENO) and their transfer into the waste stream, it can be expected that not only combustion generated nanoparticles are found in fly ashes but that many ENO finally end up in this matrix. A more detailed characterization of the nanoparticulate fraction of fly ashes is therefore needed. Physical and chemical characterizations were performed for fly ashes from five selected waste incineration plants (WIPs) with different input materials such as municipal waste, wood and sewage sludge. The intrinsic densities of the fly ashes were in the range of 2.7-3.2 g/cm(3). When the fly ash particle became airborne, the effective density depended on the particle size, increasing from 0.7-0.8 g/cm(3) for 100-150 nm to 2 g/cm(3) for 350-500 nm. The fly ash samples were fractionated at 2 μm, yielding fine fractions (2 μm). The size distributions of the fine fractions in the airborne form were further characterized, which allowed calculation of the percentage of the fly ash particles below 100 nm. We found the highest mass-based percentage was about 0.07%; the number percentage in the fine fraction was in the range of 4.8% to 22%. Comparison with modeling results showed that ENO may constitute a considerable part of the fly ash particles below 100 nm. Chemical analyses showed that for the municipal waste samples Ca and Al were present in higher concentrations in the coarse fraction; for the mixed wood and sludge sample the P concentration was higher in the coarse fraction; for most other samples and elements they were enriched in the fine fraction. Electron microscopic images of fly ashes showed a wide range of

Fly ash aggregates. Vliegaskunstgrind

Energy Technology Data Exchange (ETDEWEB)

1983-03-01

A study has been carried out into artificial aggregates made from fly ash, 'fly ash aggregates'. Attention has been drawn to the production of fly ash aggregates in the Netherlands as a way to obviate the need of disposal of fly ash. Typical process steps for the manufacturing of fly ash aggregates are the agglomeration and the bonding of fly ash particles. Agglomeration techniques are subdivided into agitation and compaction, bonding methods into sintering, hydrothermal and 'cold' bonding. In sintering no bonding agent is used. The fly ash particles are more or less welded together. Sintering in general is performed at a temperature higher than 900 deg C. In hydrothermal processes lime reacts with fly ash to a crystalline hydrate at temperatures between 100 and 250 deg C at saturated steam pressure. As a lime source not only lime as such, but also portland cement can be used. Cold bonding processes rely on reaction of fly ash with lime or cement at temperatures between 0 and 100 deg C. The pozzolanic properties of fly ash are used. Where cement is applied, this bonding agent itself contributes also to the strength development of the artificial aggregate. Besides the use of lime and cement, several processes are known which make use of lime containing wastes such as spray dry absorption desulfurization residues or fluid bed coal combustion residues. (In Dutch)

Analytical investigation of lignite and its ash samples taken from the Afsin-Elbistan coal basin in Turkey

Energy Technology Data Exchange (ETDEWEB)

Kucukonder, Adnan; Paksoy, Emine; Biber, Seyma [Kahramanmaras Suetcue Imam Univ. (Turkey). Dept. of Physics; Durdu, Burhanettin Goeker [Kilis 7 Aralik Univ., Kilis (Turkey). Opticianry Program; Baskaya, H.; Dogru, Mahmut [Bitlis Eren Univ. (Turkey). Dept. of Physics

2014-04-15

Lignite, taken from basin in Afsin-Elbistan region, and ash samples were analyzed according to the qualitative, quantitative and radioactivity properties. An elemental analysis was made by using the Energy Dispersive X-Ray Fluorescence (EDXRF) technique. 59.5 keV photons emitted from a {sup 241}Am source and 5.9 keV photons emitted from a {sup 55}Fe radioactive source were used for excitation. The characteristic K X-rays of the elements were counted with a Si(Li) detector. For the same samples gross alpha, gross beta and radionuclide activities were also measured. (orig.)

Hydration of fly ash cement and microstructure of fly ash cement pastes

Energy Technology Data Exchange (ETDEWEB)

Shiyuan, H.

1981-01-01

The strength development and hydration of fly ash cement and the influence of addition of gypsum on those were studied at normal and elevated temperatures. It was found that an addition of a proper amount of gypsum to fly ash cement could accelerate the pozzolanic reaction between CH and fly ash, and as a result, increase the strength of fly ash cement pastes after 28 days.

Persistent free radicals, heavy metals and PAHs generated in particulate soot emissions and residue ash from controlled combustion of common types of plastic

International Nuclear Information System (INIS)

Valavanidis, Athanasios; Iliopoulos, Nikiforos; Gotsis, George; Fiotakis, Konstantinos

2008-01-01

The production and use of polymeric materials worldwide has reached levels of 150 million tonnes per year, and the majority of plastic materials are discarded in waste landfills where are burned generating toxic emissions. In the present study we conducted laboratory experiments for batch combustion/burning of commercial polymeric materials, simulating conditions of open fire combustion, with the purpose to analyze their emissions for chemical characteristics of toxicological importance. We used common types of plastic materials: poly(vinyl chloride) (PVC), low and high density poly(ethylene) (LDPE, HDPE), poly(styrene) (PS), poly(propylene) (PP) and poly(ethylene terephthalate) (PET). Samples of particulate smoke (soot) collected on filters and residue solid ash produced by controlled burning conditions at 600-750 deg. C are used for analysis. Emissions of particulate matter, persistent free radicals embedded in the carbonaceous polymeric matrix, heavy metals, other elements and PAHs were determined in both types of samples. Results showed that all plastics burned easily generating charred residue solid ash and black airborne particulate smoke. Persistent carbon- and oxygen-centered radicals, known for their toxic effects in inhalable airborne particles, were detected in both particulate smoke emissions and residue solid ash. Concentrations of heavy metals and other elements (determined by Inductively Coupled Plasma Emission Spectrometry, ICP, method) were measured in the airborne soot and residue ash. Toxic heavy metals, such as Pb, Zn, Cr, Ni, and Cd were relatively at were found at low concentrations. High concentrations were found for some lithophilic elements, such as Na, Ca, Mg, Si and Al in particulate soot and residue solid ash. Measurements of PAHs showed that low molecular weight PAHs were at higher concentrations in the airborne particulate soot than in the residue solid ash for all types of plastic. Higher-ringed PAHs were detected at higher

Persistent free radicals, heavy metals and PAHs generated in particulate soot emissions and residue ash from controlled combustion of common types of plastic.

Science.gov (United States)

Valavanidis, Athanasios; Iliopoulos, Nikiforos; Gotsis, George; Fiotakis, Konstantinos

2008-08-15

The production and use of polymeric materials worldwide has reached levels of 150 million tonnes per year, and the majority of plastic materials are discarded in waste landfills where are burned generating toxic emissions. In the present study we conducted laboratory experiments for batch combustion/burning of commercial polymeric materials, simulating conditions of open fire combustion, with the purpose to analyze their emissions for chemical characteristics of toxicological importance. We used common types of plastic materials: poly(vinyl chloride) (PVC), low and high density poly(ethylene) (LDPE, HDPE), poly(styrene) (PS), poly(propylene) (PP) and poly(ethylene terephthalate) (PET). Samples of particulate smoke (soot) collected on filters and residue solid ash produced by controlled burning conditions at 600-750 degrees C are used for analysis. Emissions of particulate matter, persistent free radicals embedded in the carbonaceous polymeric matrix, heavy metals, other elements and PAHs were determined in both types of samples. Results showed that all plastics burned easily generating charred residue solid ash and black airborne particulate smoke. Persistent carbon- and oxygen-centered radicals, known for their toxic effects in inhalable airborne particles, were detected in both particulate smoke emissions and residue solid ash. Concentrations of heavy metals and other elements (determined by Inductively Coupled Plasma Emission Spectrometry, ICP, method) were measured in the airborne soot and residue ash. Toxic heavy metals, such as Pb, Zn, Cr, Ni, and Cd were relatively at were found at low concentrations. High concentrations were found for some lithophilic elements, such as Na, Ca, Mg, Si and Al in particulate soot and residue solid ash. Measurements of PAHs showed that low molecular weight PAHs were at higher concentrations in the airborne particulate soot than in the residue solid ash for all types of plastic. Higher-ringed PAHs were detected at higher

Multielemental determination in ten maize plant fragment using neutron activation analysis

International Nuclear Information System (INIS)

Spiridon, S.

1993-01-01

An instrumental activation technique has been developed for simultaneous analysis in dry ash maize plant samples of 18 elements: Al, Au, Ca, Ce, Co, Cr, Cs, Eu, Fe, La, Lu, K, Mg, Mn, Na, Rb, Sc, and Zn. Ten fragments of maize plants (dry ash) were analysed: leaves sheaths, beads, stumps, peduncles, spikes, unfruitfuls, interknots, knots, and corn husks, with a content distribution of the elements from percent to ppm. A precision of 5-7 % has been achieved on the basis of replicate analysis. The method is relatively simple and suitable for the analysis of biological samples. (Author)

Glass-ceramic from mixtures of bottom ash and fly ash.

Science.gov (United States)

Vu, Dinh Hieu; Wang, Kuen-Sheng; Chen, Jung-Hsing; Nam, Bui Xuan; Bac, Bui Hoang

2012-12-01

Along with the gradually increasing yield of the residues, appropriate management and treatment of the residues have become an urgent environmental protection problem. This work investigated the preparation of a glass-ceramic from a mixture of bottom ash and fly ash by petrurgic method. The nucleation and crystallization kinetics of the new glass-ceramic can be obtained by melting the mixture of 80% bottom ash and 20% fly ash at 950 °C, which was then cooled in the furnace for 1h. Major minerals forming in the glass-ceramics mainly are gehlenite (Ca(2)Al(2)SiO(7)) & akermanite (Ca(2)MgSiO(7)) and wollastonite (CaSiO(3)). In addition, regarding chemical/mechanical properties, the chemical resistance showing durability, and the leaching concentration of heavy metals confirmed the possibility of engineering and construction applications of the most superior glass-ceramic product. Finally, petrurgic method of a mixture of bottom ash and fly ash at 950 °C represents a simple, inexpensive, and energy saving method compared with the conventional heat treatment. Copyright © 2012 Elsevier Ltd. All rights reserved.

Co-combustion of anthracite coal and wood pellets: Thermodynamic analysis, combustion efficiency, pollutant emissions and ash slagging.

Science.gov (United States)

Guo, Feihong; Zhong, Zhaoping

2018-08-01

This work presents studies on the co-combustion of anthracite coal and wood pellets in fluidized bed. Prior to the fluidized bed combustion, thermogravimetric analysis are performed to investigate the thermodynamic behavior of coal and wood pellets. The results show that the thermal decomposition of blends is divided into four stages. The co-firing of coal and wood pellets can promote the combustion reaction and reduce the emission of gaseous pollutants, such as SO 2 and NO. It is important to choose the proportion of wood pellets during co-combustion due to the low combustion efficiency caused by large pellets with poor fluidization. Wood pellets can inhibit the volatilization of trace elements, especially for Cr, Ni and V. In addition, the slagging ratio of wood pellets ash is reduced by co-firing with coal. The research on combustion of coal and wood pellets is of great significance in engineering. Copyright © 2018 Elsevier Ltd. All rights reserved.

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....

Arsenic, chromium and mercury removal using mussel shell ash or a sludge/ashes waste mixture.

Science.gov (United States)

Seco-Reigosa, Natalia; Peña-Rodríguez, Susana; Nóvoa-Muñoz, Juan Carlos; Arias-Estévez, Manuel; Fernández-Sanjurjo, María J; Alvarez-Rodríguez, Esperanza; Núñez-Delgado, Avelino

2013-04-01

Different batches of valued mussel shell and waste mussel shell ash are characterised. Shell ash has pH > 12 and high electrical conductivities (between 16.01 and 27.27 dS m(-1)), while calcined shell shows pH values up to 10.7 and electrical conductivities between 1.19 and 3.55 dS m(-1). X-ray fluorescence, nitric acid digestion and water extractions show higher concentrations in shell ash for most parameters. Calcite is the dominant crystalline compound in this ash (95.6%), followed by aragonite. Adsorption/desorption trials were performed for mussel shell ash and for a waste mixture including shell ash, sewage sludge and wood ash, showing the following percentage adsorptions: Hg(II) >94%, As(V) >96% and Cr(VI) between 11 and 30% for shell ash; Hg(II) >98%, As(V) >88% and Cr(VI) between 30 and 88% for the waste mixture. Hg and As desorption was ash and the waste mixture, while Cr desorption was between 92 and 45% for shell ash, and between 19 and 0% for the mixture. In view of that, mussel shell ash and the mixture including shell ash, sewage sludge and wood ash could be useful for Hg(II) and As(V) removal.

Exploring the molecular and biochemical basis of ash resistance to emerald ash borer

Science.gov (United States)

Justin G.A. Whitehill; Daniel A. Herms; Pierluigi. Bonello

2010-01-01

Larvae of the emerald ash borer (EAB) (Agrilus planipennis) feed on phloem of ash (Fraxinus spp.) trees. It is hypothesized that the resistance of Asian species of ash (e.g., Manchurian ash, F. mandshurica) to EAB is due to endogenous defenses present in phloem tissues in the form of defensive proteins and/or...

A case study of the long-term retention of 137Cs after inhalation of high temperature reactor fuel element ash.

Science.gov (United States)

Froning, M; Kozielewski, T; Schläger, M; Hill, P

2004-01-01

In 1987, a worker was internally contaminated with 137Cs as a result of an accident during the handling of high temperature reactor fuel element ash. In the long-term follow-up monitoring an unusual retention behaviour was found. The observed time dependence of caesium retention does not agree with the standard models of ICRP Publication 30. The present case can be better explained by assuming an intake of a mixture of type F and type S compounds. However, experimental data can be best described by a four-exponential retention function with two long-lived components, which was used as an ad hoc model for dose calculation. The resulting dose is compared with doses calculated on the basis of ICRP Publication 66.

An ecophysiological study of plants growing on the fly ash deposits from the "Nikola Tesla-A" thermal power station in Serbia.

Science.gov (United States)

Pavlović, Pavle; Mitrović, Miroslava; Djurdjević, Lola

2004-05-01

This ecophysiological research on the ash deposits from the "Nikola Tesla-A" thermal power station in Serbia covered 10 plant species (Tamarix gallica, Populus alba, Spiraea van-hauttei, Ambrosia artemisifolia, Amorpha fruticosa, Eupatorium cannabinum, Crepis setosa, Epilobium collinum, Verbascum phlomoides, and Cirsium arvense). This paper presents the results of a water regime analysis, photosynthetic efficiency and trace elements (B, Cu, Mn, Zn, Pb, and Cd) content in vegetative plant parts. Water regime parameters indicate an overall stability in plant-water relations. During the period of summer drought, photosynthetic efficiency (Fv/Fm) was low, ranging from 0.429 to 0.620 for all the species that were analyzed. An analysis of the tissue trace elements content showed a lower trace metal concentration in the plants than in the ash, indicating that heavy metals undergo major concentration during the combustion process and some are not readily taken up by plants. The Zn and Pb concentrations in all of the examined species were normal whereas Cu and Mn concentrations were in the deficiency range. Boron concentrations in plant tissues were high, with some species even showing levels of more than 100 microg/g (Populus sp., Ambrosia sp., Amorpha sp., and Cirsium sp.). The presence of Cd was not detected. In general, it can be concluded from the results of this research that biological recultivation should take into account the existing ecological, vegetation, and floristic potential of an immediate environment that is abundant in life forms and ecological types of plant species that can overgrow the ash deposit relatively quickly. Selected species should be adapted to toxic B concentrations with moderate demands in terms of mineral elements (Cu and Mn).

Plant and animal species composition and heavy metal content in fly ash ecosystems

International Nuclear Information System (INIS)

Brieger, G.; Wells, J.R.; Hunter, R.D.

1992-01-01

Plant and animal species present on a coal fly ash slurry pond site and a dry deposit site were surveyed and sampled during a two-day period in October. Elemental analyses were determined for most of the species encountered. A total of 48 plant species were observed on the two sites, with 35 species on the wet site, and 20 on the dry site. Eighteen terrestrial and 7 aquatic animal species were found on the wet site, exclusive of vertebrates which were not studied with the exception of a carp (Cyprinus carpio). Eleven terrestrial invertebrate and one aquatic species were observed on the dry site. Neutron activation analysis was carried out for: Se, Hg, Cr, Ni, Zn, Co, Sb, Cd, and As. Using literature values for phytotoxicity, it is concluded that, in general, plants did not accumulate toxic levels of metals. Only one plant (Impatiens biflora Willd.) showed a significant level of Cd. Of 20 plants analyzed on the wet site, 10 had excessive Se concentrations (>5 ppm); on the dry site 6 out of 18 had high Se values. In animals (Gryllus sp.; Melanoplus sp.; Trachelipus sp; Lumbricus terrestris; Physa integra; Cyprinus carpio) the trace metal concentration was generally in between that of control animals and that of the fly ash itself. One exception included Zn, which, although the most variable element examined, was concentrated in all the terrestrial animals to levels higher than in fly ash. Crickets are the most consistent bioconcentrators with Cr, Se, and Zn at higher levels than for control animals. All animals species studied accumulated Se compared to controls. 48 refs., 6 tabs

Wood ash residue causes a mixture of growth promotion and toxicity in Lemna minor.

Science.gov (United States)

Jagodzinski, Lucas S; O'Donoghue, Marian T; Heffernan, Liam B; van Pelt, Frank N A M; O'Halloran, John; Jansen, Marcel A K

2018-06-01

The use of wood as a sustainable biofuel results in the generation of residual wood ash. The ash contains high amounts of plant macronutrients such as phosphorus, potassium, calcium as well as several micronutrients. To explore the potential use of wood ash as a fertiliser, the growth enhancing properties of Sitka spruce (Picea sitchensis Bong.) wood ash were contrasted with the potential toxic action, using common duckweed (Lemna minor L.) as a model test species. The growth of L. minor exposed to wood bottom and fly ash solids and corresponding leachates was assessed in ultra-oligotrophic and eutrophic media. Ash solids and leachates were also tested as neutralized preparations. Suspended ash solids promoted L. minor growth up to concentrations of 2.5-5g/L. Leachates promoted growth up to 10g ash equivalents per litre, but for bottom ash only. Beneficial effects of wood ash were most pronounced on ultra-oligotrophic medium. However, on such nutrient-deficient medium severe inhibition of L. minor biomass and frond growth was observed at relatively low concentrations of fly ash (EC 50 =14g/L). On standard, eutrophic medium, higher concentrations of fly ash (EC 50 =21g/L), or neutralized fly ash (EC 50 =37g/L) were required to impede growth. Bottom ash, or neutralized bottom ash retarded growth at concentrations of 51g/L and 74g/L (EC 50 ), respectively, in eutrophic medium. It appears that phytotoxicity is due to the elemental composition of the ash, its alkaline character, and possible interactions between these two properties. Growth promotion was due to the substantial content of plant nutrients. This study underlines the importance of the receiving environment (nutrient status and pH) in determining the balance between toxicity and growth promotion, and shows that the margin between growth promoting and toxicity inducing concentrations can be enlarged through ash neutralization. Copyright © 2017 Elsevier B.V. All rights reserved.

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